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authorRafael J. Wysocki <rjw@sisk.pl>2009-09-14 20:26:05 +0200
committerRafael J. Wysocki <rjw@sisk.pl>2009-09-14 20:26:05 +0200
commitac8d513a6801c8636922ccf4f30211810c9a56ce (patch)
tree83ba584487a6a612c8fcf2563c28c0263df35ba2 /kernel
parentbf992fa2bc1ad1bb2aeb0bdfadb43f236b9297fd (diff)
parent99bc47067910f7070e65ee318a6dd79a2371f1e5 (diff)
downloadlinux-ac8d513a6801c8636922ccf4f30211810c9a56ce.tar.bz2
Merge branch 'master' into for-linus
Diffstat (limited to 'kernel')
-rw-r--r--kernel/Makefile4
-rw-r--r--kernel/acct.c8
-rw-r--r--kernel/cgroup.c1
-rw-r--r--kernel/cred.c293
-rw-r--r--kernel/exit.c5
-rw-r--r--kernel/fork.c11
-rw-r--r--kernel/futex.c47
-rw-r--r--kernel/hrtimer.c2
-rw-r--r--kernel/irq/chip.c74
-rw-r--r--kernel/irq/handle.c5
-rw-r--r--kernel/irq/internals.h13
-rw-r--r--kernel/irq/manage.c102
-rw-r--r--kernel/irq/pm.c8
-rw-r--r--kernel/irq/resend.c3
-rw-r--r--kernel/irq/spurious.c1
-rw-r--r--kernel/kmod.c9
-rw-r--r--kernel/kprobes.c30
-rw-r--r--kernel/kthread.c4
-rw-r--r--kernel/lockdep.c792
-rw-r--r--kernel/lockdep_internals.h2
-rw-r--r--kernel/lockdep_proc.c128
-rw-r--r--kernel/module.c11
-rw-r--r--kernel/perf_counter.c173
-rw-r--r--kernel/printk.c175
-rw-r--r--kernel/ptrace.c2
-rw-r--r--kernel/rcuclassic.c807
-rw-r--r--kernel/rcupdate.c44
-rw-r--r--kernel/rcupreempt.c1539
-rw-r--r--kernel/rcupreempt_trace.c334
-rw-r--r--kernel/rcutorture.c202
-rw-r--r--kernel/rcutree.c280
-rw-r--r--kernel/rcutree.h253
-rw-r--r--kernel/rcutree_plugin.h532
-rw-r--r--kernel/rcutree_trace.c88
-rw-r--r--kernel/sched.c1232
-rw-r--r--kernel/sched_cpupri.c30
-rw-r--r--kernel/sched_debug.c4
-rw-r--r--kernel/sched_fair.c84
-rw-r--r--kernel/sched_features.h2
-rw-r--r--kernel/sched_rt.c62
-rw-r--r--kernel/softirq.c4
-rw-r--r--kernel/spinlock.c230
-rw-r--r--kernel/sysctl.c25
-rw-r--r--kernel/taskstats.c10
-rw-r--r--kernel/timer.c3
-rw-r--r--kernel/trace/Kconfig13
-rw-r--r--kernel/trace/blktrace.c12
-rw-r--r--kernel/trace/ftrace.c107
-rw-r--r--kernel/trace/kmemtrace.c149
-rw-r--r--kernel/trace/ring_buffer.c1112
-rw-r--r--kernel/trace/trace.c679
-rw-r--r--kernel/trace/trace.h76
-rw-r--r--kernel/trace/trace_boot.c16
-rw-r--r--kernel/trace/trace_events.c146
-rw-r--r--kernel/trace/trace_events_filter.c261
-rw-r--r--kernel/trace/trace_export.c28
-rw-r--r--kernel/trace/trace_functions.c4
-rw-r--r--kernel/trace/trace_functions_graph.c166
-rw-r--r--kernel/trace/trace_irqsoff.c3
-rw-r--r--kernel/trace/trace_mmiotrace.c10
-rw-r--r--kernel/trace/trace_power.c22
-rw-r--r--kernel/trace/trace_sched_switch.c59
-rw-r--r--kernel/trace/trace_sched_wakeup.c7
-rw-r--r--kernel/trace/trace_selftest.c1
-rw-r--r--kernel/trace/trace_stack.c43
-rw-r--r--kernel/trace/trace_stat.c17
-rw-r--r--kernel/trace/trace_stat.h2
-rw-r--r--kernel/trace/trace_syscalls.c471
-rw-r--r--kernel/trace/trace_workqueue.c32
-rw-r--r--kernel/tracepoint.c50
-rw-r--r--kernel/workqueue.c9
71 files changed, 6001 insertions, 5162 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index 2093a691f1c2..b833bd5cc127 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -80,11 +80,9 @@ obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o
obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
obj-$(CONFIG_SECCOMP) += seccomp.o
obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
-obj-$(CONFIG_CLASSIC_RCU) += rcuclassic.o
obj-$(CONFIG_TREE_RCU) += rcutree.o
-obj-$(CONFIG_PREEMPT_RCU) += rcupreempt.o
+obj-$(CONFIG_TREE_PREEMPT_RCU) += rcutree.o
obj-$(CONFIG_TREE_RCU_TRACE) += rcutree_trace.o
-obj-$(CONFIG_PREEMPT_RCU_TRACE) += rcupreempt_trace.o
obj-$(CONFIG_RELAY) += relay.o
obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
diff --git a/kernel/acct.c b/kernel/acct.c
index 9f3391090b3e..9a4715a2f6bf 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -491,13 +491,17 @@ static void do_acct_process(struct bsd_acct_struct *acct,
u64 run_time;
struct timespec uptime;
struct tty_struct *tty;
+ const struct cred *orig_cred;
+
+ /* Perform file operations on behalf of whoever enabled accounting */
+ orig_cred = override_creds(file->f_cred);
/*
* First check to see if there is enough free_space to continue
* the process accounting system.
*/
if (!check_free_space(acct, file))
- return;
+ goto out;
/*
* Fill the accounting struct with the needed info as recorded
@@ -578,6 +582,8 @@ static void do_acct_process(struct bsd_acct_struct *acct,
sizeof(acct_t), &file->f_pos);
current->signal->rlim[RLIMIT_FSIZE].rlim_cur = flim;
set_fs(fs);
+out:
+ revert_creds(orig_cred);
}
/**
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index b6eadfe30e7b..c7ece8f027f2 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -600,6 +600,7 @@ static struct inode_operations cgroup_dir_inode_operations;
static struct file_operations proc_cgroupstats_operations;
static struct backing_dev_info cgroup_backing_dev_info = {
+ .name = "cgroup",
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
diff --git a/kernel/cred.c b/kernel/cred.c
index 1bb4d7e5d616..006fcab009d5 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -18,6 +18,18 @@
#include <linux/cn_proc.h>
#include "cred-internals.h"
+#if 0
+#define kdebug(FMT, ...) \
+ printk("[%-5.5s%5u] "FMT"\n", current->comm, current->pid ,##__VA_ARGS__)
+#else
+static inline __attribute__((format(printf, 1, 2)))
+void no_printk(const char *fmt, ...)
+{
+}
+#define kdebug(FMT, ...) \
+ no_printk("[%-5.5s%5u] "FMT"\n", current->comm, current->pid ,##__VA_ARGS__)
+#endif
+
static struct kmem_cache *cred_jar;
/*
@@ -36,6 +48,10 @@ static struct thread_group_cred init_tgcred = {
*/
struct cred init_cred = {
.usage = ATOMIC_INIT(4),
+#ifdef CONFIG_DEBUG_CREDENTIALS
+ .subscribers = ATOMIC_INIT(2),
+ .magic = CRED_MAGIC,
+#endif
.securebits = SECUREBITS_DEFAULT,
.cap_inheritable = CAP_INIT_INH_SET,
.cap_permitted = CAP_FULL_SET,
@@ -48,6 +64,31 @@ struct cred init_cred = {
#endif
};
+static inline void set_cred_subscribers(struct cred *cred, int n)
+{
+#ifdef CONFIG_DEBUG_CREDENTIALS
+ atomic_set(&cred->subscribers, n);
+#endif
+}
+
+static inline int read_cred_subscribers(const struct cred *cred)
+{
+#ifdef CONFIG_DEBUG_CREDENTIALS
+ return atomic_read(&cred->subscribers);
+#else
+ return 0;
+#endif
+}
+
+static inline void alter_cred_subscribers(const struct cred *_cred, int n)
+{
+#ifdef CONFIG_DEBUG_CREDENTIALS
+ struct cred *cred = (struct cred *) _cred;
+
+ atomic_add(n, &cred->subscribers);
+#endif
+}
+
/*
* Dispose of the shared task group credentials
*/
@@ -85,9 +126,22 @@ static void put_cred_rcu(struct rcu_head *rcu)
{
struct cred *cred = container_of(rcu, struct cred, rcu);
+ kdebug("put_cred_rcu(%p)", cred);
+
+#ifdef CONFIG_DEBUG_CREDENTIALS
+ if (cred->magic != CRED_MAGIC_DEAD ||
+ atomic_read(&cred->usage) != 0 ||
+ read_cred_subscribers(cred) != 0)
+ panic("CRED: put_cred_rcu() sees %p with"
+ " mag %x, put %p, usage %d, subscr %d\n",
+ cred, cred->magic, cred->put_addr,
+ atomic_read(&cred->usage),
+ read_cred_subscribers(cred));
+#else
if (atomic_read(&cred->usage) != 0)
panic("CRED: put_cred_rcu() sees %p with usage %d\n",
cred, atomic_read(&cred->usage));
+#endif
security_cred_free(cred);
key_put(cred->thread_keyring);
@@ -106,12 +160,90 @@ static void put_cred_rcu(struct rcu_head *rcu)
*/
void __put_cred(struct cred *cred)
{
+ kdebug("__put_cred(%p{%d,%d})", cred,
+ atomic_read(&cred->usage),
+ read_cred_subscribers(cred));
+
BUG_ON(atomic_read(&cred->usage) != 0);
+#ifdef CONFIG_DEBUG_CREDENTIALS
+ BUG_ON(read_cred_subscribers(cred) != 0);
+ cred->magic = CRED_MAGIC_DEAD;
+ cred->put_addr = __builtin_return_address(0);
+#endif
+ BUG_ON(cred == current->cred);
+ BUG_ON(cred == current->real_cred);
call_rcu(&cred->rcu, put_cred_rcu);
}
EXPORT_SYMBOL(__put_cred);
+/*
+ * Clean up a task's credentials when it exits
+ */
+void exit_creds(struct task_struct *tsk)
+{
+ struct cred *cred;
+
+ kdebug("exit_creds(%u,%p,%p,{%d,%d})", tsk->pid, tsk->real_cred, tsk->cred,
+ atomic_read(&tsk->cred->usage),
+ read_cred_subscribers(tsk->cred));
+
+ cred = (struct cred *) tsk->real_cred;
+ tsk->real_cred = NULL;
+ validate_creds(cred);
+ alter_cred_subscribers(cred, -1);
+ put_cred(cred);
+
+ cred = (struct cred *) tsk->cred;
+ tsk->cred = NULL;
+ validate_creds(cred);
+ alter_cred_subscribers(cred, -1);
+ put_cred(cred);
+
+ cred = (struct cred *) tsk->replacement_session_keyring;
+ if (cred) {
+ tsk->replacement_session_keyring = NULL;
+ validate_creds(cred);
+ put_cred(cred);
+ }
+}
+
+/*
+ * Allocate blank credentials, such that the credentials can be filled in at a
+ * later date without risk of ENOMEM.
+ */
+struct cred *cred_alloc_blank(void)
+{
+ struct cred *new;
+
+ new = kmem_cache_zalloc(cred_jar, GFP_KERNEL);
+ if (!new)
+ return NULL;
+
+#ifdef CONFIG_KEYS
+ new->tgcred = kzalloc(sizeof(*new->tgcred), GFP_KERNEL);
+ if (!new->tgcred) {
+ kfree(new);
+ return NULL;
+ }
+ atomic_set(&new->tgcred->usage, 1);
+#endif
+
+ atomic_set(&new->usage, 1);
+
+ if (security_cred_alloc_blank(new, GFP_KERNEL) < 0)
+ goto error;
+
+#ifdef CONFIG_DEBUG_CREDENTIALS
+ new->magic = CRED_MAGIC;
+#endif
+ return new;
+
+error:
+ abort_creds(new);
+ return NULL;
+}
+
/**
* prepare_creds - Prepare a new set of credentials for modification
*
@@ -132,16 +264,19 @@ struct cred *prepare_creds(void)
const struct cred *old;
struct cred *new;
- BUG_ON(atomic_read(&task->real_cred->usage) < 1);
+ validate_process_creds();
new = kmem_cache_alloc(cred_jar, GFP_KERNEL);
if (!new)
return NULL;
+ kdebug("prepare_creds() alloc %p", new);
+
old = task->cred;
memcpy(new, old, sizeof(struct cred));
atomic_set(&new->usage, 1);
+ set_cred_subscribers(new, 0);
get_group_info(new->group_info);
get_uid(new->user);
@@ -157,6 +292,7 @@ struct cred *prepare_creds(void)
if (security_prepare_creds(new, old, GFP_KERNEL) < 0)
goto error;
+ validate_creds(new);
return new;
error:
@@ -229,9 +365,12 @@ struct cred *prepare_usermodehelper_creds(void)
if (!new)
return NULL;
+ kdebug("prepare_usermodehelper_creds() alloc %p", new);
+
memcpy(new, &init_cred, sizeof(struct cred));
atomic_set(&new->usage, 1);
+ set_cred_subscribers(new, 0);
get_group_info(new->group_info);
get_uid(new->user);
@@ -250,6 +389,7 @@ struct cred *prepare_usermodehelper_creds(void)
#endif
if (security_prepare_creds(new, &init_cred, GFP_ATOMIC) < 0)
goto error;
+ validate_creds(new);
BUG_ON(atomic_read(&new->usage) != 1);
return new;
@@ -286,6 +426,10 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags)
) {
p->real_cred = get_cred(p->cred);
get_cred(p->cred);
+ alter_cred_subscribers(p->cred, 2);
+ kdebug("share_creds(%p{%d,%d})",
+ p->cred, atomic_read(&p->cred->usage),
+ read_cred_subscribers(p->cred));
atomic_inc(&p->cred->user->processes);
return 0;
}
@@ -331,6 +475,8 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags)
atomic_inc(&new->user->processes);
p->cred = p->real_cred = get_cred(new);
+ alter_cred_subscribers(new, 2);
+ validate_creds(new);
return 0;
error_put:
@@ -355,13 +501,20 @@ error_put:
int commit_creds(struct cred *new)
{
struct task_struct *task = current;
- const struct cred *old;
+ const struct cred *old = task->real_cred;
- BUG_ON(task->cred != task->real_cred);
- BUG_ON(atomic_read(&task->real_cred->usage) < 2);
+ kdebug("commit_creds(%p{%d,%d})", new,
+ atomic_read(&new->usage),
+ read_cred_subscribers(new));
+
+ BUG_ON(task->cred != old);
+#ifdef CONFIG_DEBUG_CREDENTIALS
+ BUG_ON(read_cred_subscribers(old) < 2);
+ validate_creds(old);
+ validate_creds(new);
+#endif
BUG_ON(atomic_read(&new->usage) < 1);
- old = task->real_cred;
security_commit_creds(new, old);
get_cred(new); /* we will require a ref for the subj creds too */
@@ -390,12 +543,14 @@ int commit_creds(struct cred *new)
* cheaply with the new uid cache, so if it matters
* we should be checking for it. -DaveM
*/
+ alter_cred_subscribers(new, 2);
if (new->user != old->user)
atomic_inc(&new->user->processes);
rcu_assign_pointer(task->real_cred, new);
rcu_assign_pointer(task->cred, new);
if (new->user != old->user)
atomic_dec(&old->user->processes);
+ alter_cred_subscribers(old, -2);
sched_switch_user(task);
@@ -428,6 +583,13 @@ EXPORT_SYMBOL(commit_creds);
*/
void abort_creds(struct cred *new)
{
+ kdebug("abort_creds(%p{%d,%d})", new,
+ atomic_read(&new->usage),
+ read_cred_subscribers(new));
+
+#ifdef CONFIG_DEBUG_CREDENTIALS
+ BUG_ON(read_cred_subscribers(new) != 0);
+#endif
BUG_ON(atomic_read(&new->usage) < 1);
put_cred(new);
}
@@ -444,7 +606,20 @@ const struct cred *override_creds(const struct cred *new)
{
const struct cred *old = current->cred;
- rcu_assign_pointer(current->cred, get_cred(new));
+ kdebug("override_creds(%p{%d,%d})", new,
+ atomic_read(&new->usage),
+ read_cred_subscribers(new));
+
+ validate_creds(old);
+ validate_creds(new);
+ get_cred(new);
+ alter_cred_subscribers(new, 1);
+ rcu_assign_pointer(current->cred, new);
+ alter_cred_subscribers(old, -1);
+
+ kdebug("override_creds() = %p{%d,%d}", old,
+ atomic_read(&old->usage),
+ read_cred_subscribers(old));
return old;
}
EXPORT_SYMBOL(override_creds);
@@ -460,7 +635,15 @@ void revert_creds(const struct cred *old)
{
const struct cred *override = current->cred;
+ kdebug("revert_creds(%p{%d,%d})", old,
+ atomic_read(&old->usage),
+ read_cred_subscribers(old));
+
+ validate_creds(old);
+ validate_creds(override);
+ alter_cred_subscribers(old, 1);
rcu_assign_pointer(current->cred, old);
+ alter_cred_subscribers(override, -1);
put_cred(override);
}
EXPORT_SYMBOL(revert_creds);
@@ -502,11 +685,15 @@ struct cred *prepare_kernel_cred(struct task_struct *daemon)
if (!new)
return NULL;
+ kdebug("prepare_kernel_cred() alloc %p", new);
+
if (daemon)
old = get_task_cred(daemon);
else
old = get_cred(&init_cred);
+ validate_creds(old);
+
*new = *old;
get_uid(new->user);
get_group_info(new->group_info);
@@ -526,7 +713,9 @@ struct cred *prepare_kernel_cred(struct task_struct *daemon)
goto error;
atomic_set(&new->usage, 1);
+ set_cred_subscribers(new, 0);
put_cred(old);
+ validate_creds(new);
return new;
error:
@@ -589,3 +778,95 @@ int set_create_files_as(struct cred *new, struct inode *inode)
return security_kernel_create_files_as(new, inode);
}
EXPORT_SYMBOL(set_create_files_as);
+
+#ifdef CONFIG_DEBUG_CREDENTIALS
+
+/*
+ * dump invalid credentials
+ */
+static void dump_invalid_creds(const struct cred *cred, const char *label,
+ const struct task_struct *tsk)
+{
+ printk(KERN_ERR "CRED: %s credentials: %p %s%s%s\n",
+ label, cred,
+ cred == &init_cred ? "[init]" : "",
+ cred == tsk->real_cred ? "[real]" : "",
+ cred == tsk->cred ? "[eff]" : "");
+ printk(KERN_ERR "CRED: ->magic=%x, put_addr=%p\n",
+ cred->magic, cred->put_addr);
+ printk(KERN_ERR "CRED: ->usage=%d, subscr=%d\n",
+ atomic_read(&cred->usage),
+ read_cred_subscribers(cred));
+ printk(KERN_ERR "CRED: ->*uid = { %d,%d,%d,%d }\n",
+ cred->uid, cred->euid, cred->suid, cred->fsuid);
+ printk(KERN_ERR "CRED: ->*gid = { %d,%d,%d,%d }\n",
+ cred->gid, cred->egid, cred->sgid, cred->fsgid);
+#ifdef CONFIG_SECURITY
+ printk(KERN_ERR "CRED: ->security is %p\n", cred->security);
+ if ((unsigned long) cred->security >= PAGE_SIZE &&
+ (((unsigned long) cred->security & 0xffffff00) !=
+ (POISON_FREE << 24 | POISON_FREE << 16 | POISON_FREE << 8)))
+ printk(KERN_ERR "CRED: ->security {%x, %x}\n",
+ ((u32*)cred->security)[0],
+ ((u32*)cred->security)[1]);
+#endif
+}
+
+/*
+ * report use of invalid credentials
+ */
+void __invalid_creds(const struct cred *cred, const char *file, unsigned line)
+{
+ printk(KERN_ERR "CRED: Invalid credentials\n");
+ printk(KERN_ERR "CRED: At %s:%u\n", file, line);
+ dump_invalid_creds(cred, "Specified", current);
+ BUG();
+}
+EXPORT_SYMBOL(__invalid_creds);
+
+/*
+ * check the credentials on a process
+ */
+void __validate_process_creds(struct task_struct *tsk,
+ const char *file, unsigned line)
+{
+ if (tsk->cred == tsk->real_cred) {
+ if (unlikely(read_cred_subscribers(tsk->cred) < 2 ||
+ creds_are_invalid(tsk->cred)))
+ goto invalid_creds;
+ } else {
+ if (unlikely(read_cred_subscribers(tsk->real_cred) < 1 ||
+ read_cred_subscribers(tsk->cred) < 1 ||
+ creds_are_invalid(tsk->real_cred) ||
+ creds_are_invalid(tsk->cred)))
+ goto invalid_creds;
+ }
+ return;
+
+invalid_creds:
+ printk(KERN_ERR "CRED: Invalid process credentials\n");
+ printk(KERN_ERR "CRED: At %s:%u\n", file, line);
+
+ dump_invalid_creds(tsk->real_cred, "Real", tsk);
+ if (tsk->cred != tsk->real_cred)
+ dump_invalid_creds(tsk->cred, "Effective", tsk);
+ else
+ printk(KERN_ERR "CRED: Effective creds == Real creds\n");
+ BUG();
+}
+EXPORT_SYMBOL(__validate_process_creds);
+
+/*
+ * check creds for do_exit()
+ */
+void validate_creds_for_do_exit(struct task_struct *tsk)
+{
+ kdebug("validate_creds_for_do_exit(%p,%p{%d,%d})",
+ tsk->real_cred, tsk->cred,
+ atomic_read(&tsk->cred->usage),
+ read_cred_subscribers(tsk->cred));
+
+ __validate_process_creds(tsk, __FILE__, __LINE__);
+}
+
+#endif /* CONFIG_DEBUG_CREDENTIALS */
diff --git a/kernel/exit.c b/kernel/exit.c
index 869dc221733e..ae5d8660ddff 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -901,6 +901,8 @@ NORET_TYPE void do_exit(long code)
tracehook_report_exit(&code);
+ validate_creds_for_do_exit(tsk);
+
/*
* We're taking recursive faults here in do_exit. Safest is to just
* leave this task alone and wait for reboot.
@@ -1009,7 +1011,10 @@ NORET_TYPE void do_exit(long code)
if (tsk->splice_pipe)
__free_pipe_info(tsk->splice_pipe);
+ validate_creds_for_do_exit(tsk);
+
preempt_disable();
+ exit_rcu();
/* causes final put_task_struct in finish_task_switch(). */
tsk->state = TASK_DEAD;
schedule();
diff --git a/kernel/fork.c b/kernel/fork.c
index e6c04d462ab2..bfee931ee3fb 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -152,8 +152,7 @@ void __put_task_struct(struct task_struct *tsk)
WARN_ON(atomic_read(&tsk->usage));
WARN_ON(tsk == current);
- put_cred(tsk->real_cred);
- put_cred(tsk->cred);
+ exit_creds(tsk);
delayacct_tsk_free(tsk);
if (!profile_handoff_task(tsk))
@@ -1008,10 +1007,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
copy_flags(clone_flags, p);
INIT_LIST_HEAD(&p->children);
INIT_LIST_HEAD(&p->sibling);
-#ifdef CONFIG_PREEMPT_RCU
- p->rcu_read_lock_nesting = 0;
- p->rcu_flipctr_idx = 0;
-#endif /* #ifdef CONFIG_PREEMPT_RCU */
+ rcu_copy_process(p);
p->vfork_done = NULL;
spin_lock_init(&p->alloc_lock);
@@ -1297,8 +1293,7 @@ bad_fork_cleanup_put_domain:
module_put(task_thread_info(p)->exec_domain->module);
bad_fork_cleanup_count:
atomic_dec(&p->cred->user->processes);
- put_cred(p->real_cred);
- put_cred(p->cred);
+ exit_creds(p);
bad_fork_free:
free_task(p);
fork_out:
diff --git a/kernel/futex.c b/kernel/futex.c
index e18cfbdc7190..248dd119a86e 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -115,6 +115,9 @@ struct futex_q {
/* rt_waiter storage for requeue_pi: */
struct rt_mutex_waiter *rt_waiter;
+ /* The expected requeue pi target futex key: */
+ union futex_key *requeue_pi_key;
+
/* Bitset for the optional bitmasked wakeup */
u32 bitset;
};
@@ -1089,6 +1092,10 @@ static int futex_proxy_trylock_atomic(u32 __user *pifutex,
if (!top_waiter)
return 0;
+ /* Ensure we requeue to the expected futex. */
+ if (!match_futex(top_waiter->requeue_pi_key, key2))
+ return -EINVAL;
+
/*
* Try to take the lock for top_waiter. Set the FUTEX_WAITERS bit in
* the contended case or if set_waiters is 1. The pi_state is returned
@@ -1276,6 +1283,12 @@ retry_private:
continue;
}
+ /* Ensure we requeue to the expected futex for requeue_pi. */
+ if (requeue_pi && !match_futex(this->requeue_pi_key, &key2)) {
+ ret = -EINVAL;
+ break;
+ }
+
/*
* Requeue nr_requeue waiters and possibly one more in the case
* of requeue_pi if we couldn't acquire the lock atomically.
@@ -1751,6 +1764,7 @@ static int futex_wait(u32 __user *uaddr, int fshared,
q.pi_state = NULL;
q.bitset = bitset;
q.rt_waiter = NULL;
+ q.requeue_pi_key = NULL;
if (abs_time) {
to = &timeout;
@@ -1858,6 +1872,7 @@ static int futex_lock_pi(u32 __user *uaddr, int fshared,
q.pi_state = NULL;
q.rt_waiter = NULL;
+ q.requeue_pi_key = NULL;
retry:
q.key = FUTEX_KEY_INIT;
ret = get_futex_key(uaddr, fshared, &q.key, VERIFY_WRITE);
@@ -2118,11 +2133,11 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
* We call schedule in futex_wait_queue_me() when we enqueue and return there
* via the following:
* 1) wakeup on uaddr2 after an atomic lock acquisition by futex_requeue()
- * 2) wakeup on uaddr2 after a requeue and subsequent unlock
- * 3) signal (before or after requeue)
- * 4) timeout (before or after requeue)
+ * 2) wakeup on uaddr2 after a requeue
+ * 3) signal
+ * 4) timeout
*
- * If 3, we setup a restart_block with futex_wait_requeue_pi() as the function.
+ * If 3, cleanup and return -ERESTARTNOINTR.
*
* If 2, we may then block on trying to take the rt_mutex and return via:
* 5) successful lock
@@ -2130,7 +2145,7 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
* 7) timeout
* 8) other lock acquisition failure
*
- * If 6, we setup a restart_block with futex_lock_pi() as the function.
+ * If 6, return -EWOULDBLOCK (restarting the syscall would do the same).
*
* If 4 or 7, we cleanup and return with -ETIMEDOUT.
*
@@ -2169,15 +2184,16 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared,
debug_rt_mutex_init_waiter(&rt_waiter);
rt_waiter.task = NULL;
- q.pi_state = NULL;
- q.bitset = bitset;
- q.rt_waiter = &rt_waiter;
-
key2 = FUTEX_KEY_INIT;
ret = get_futex_key(uaddr2, fshared, &key2, VERIFY_WRITE);
if (unlikely(ret != 0))
goto out;
+ q.pi_state = NULL;
+ q.bitset = bitset;
+ q.rt_waiter = &rt_waiter;
+ q.requeue_pi_key = &key2;
+
/* Prepare to wait on uaddr. */
ret = futex_wait_setup(uaddr, val, fshared, &q, &hb);
if (ret)
@@ -2248,14 +2264,11 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared,
rt_mutex_unlock(pi_mutex);
} else if (ret == -EINTR) {
/*
- * We've already been requeued, but we have no way to
- * restart by calling futex_lock_pi() directly. We
- * could restart the syscall, but that will look at
- * the user space value and return right away. So we
- * drop back with EWOULDBLOCK to tell user space that
- * "val" has been changed. That's the same what the
- * restart of the syscall would do in
- * futex_wait_setup().
+ * We've already been requeued, but cannot restart by calling
+ * futex_lock_pi() directly. We could restart this syscall, but
+ * it would detect that the user space "val" changed and return
+ * -EWOULDBLOCK. Save the overhead of the restart and return
+ * -EWOULDBLOCK directly.
*/
ret = -EWOULDBLOCK;
}
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 49da79ab8486..05071bf6a37b 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -485,6 +485,7 @@ void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id,
debug_object_init_on_stack(timer, &hrtimer_debug_descr);
__hrtimer_init(timer, clock_id, mode);
}
+EXPORT_SYMBOL_GPL(hrtimer_init_on_stack);
void destroy_hrtimer_on_stack(struct hrtimer *timer)
{
@@ -1477,6 +1478,7 @@ void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
sl->timer.function = hrtimer_wakeup;
sl->task = task;
}
+EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
{
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 13c68e71b726..c1660194d115 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -222,6 +222,34 @@ int set_irq_chip_data(unsigned int irq, void *data)
}
EXPORT_SYMBOL(set_irq_chip_data);
+/**
+ * set_irq_nested_thread - Set/Reset the IRQ_NESTED_THREAD flag of an irq
+ *
+ * @irq: Interrupt number
+ * @nest: 0 to clear / 1 to set the IRQ_NESTED_THREAD flag
+ *
+ * The IRQ_NESTED_THREAD flag indicates that on
+ * request_threaded_irq() no separate interrupt thread should be
+ * created for the irq as the handler are called nested in the
+ * context of a demultiplexing interrupt handler thread.
+ */
+void set_irq_nested_thread(unsigned int irq, int nest)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ unsigned long flags;
+
+ if (!desc)
+ return;
+
+ spin_lock_irqsave(&desc->lock, flags);
+ if (nest)
+ desc->status |= IRQ_NESTED_THREAD;
+ else
+ desc->status &= ~IRQ_NESTED_THREAD;
+ spin_unlock_irqrestore(&desc->lock, flags);
+}
+EXPORT_SYMBOL_GPL(set_irq_nested_thread);
+
/*
* default enable function
*/
@@ -299,6 +327,45 @@ static inline void mask_ack_irq(struct irq_desc *desc, int irq)
}
}
+/*
+ * handle_nested_irq - Handle a nested irq from a irq thread
+ * @irq: the interrupt number
+ *
+ * Handle interrupts which are nested into a threaded interrupt
+ * handler. The handler function is called inside the calling
+ * threads context.
+ */
+void handle_nested_irq(unsigned int irq)
+{
+ struct irq_desc *desc = irq_to_desc(irq);
+ struct irqaction *action;
+ irqreturn_t action_ret;
+
+ might_sleep();
+
+ spin_lock_irq(&desc->lock);
+
+ kstat_incr_irqs_this_cpu(irq, desc);
+
+ action = desc->action;
+ if (unlikely(!action || (desc->status & IRQ_DISABLED)))
+ goto out_unlock;
+
+ desc->status |= IRQ_INPROGRESS;
+ spin_unlock_irq(&desc->lock);
+
+ action_ret = action->thread_fn(action->irq, action->dev_id);
+ if (!noirqdebug)
+ note_interrupt(irq, desc, action_ret);
+
+ spin_lock_irq(&desc->lock);
+ desc->status &= ~IRQ_INPROGRESS;
+
+out_unlock:
+ spin_unlock_irq(&desc->lock);
+}
+EXPORT_SYMBOL_GPL(handle_nested_irq);
+
/**
* handle_simple_irq - Simple and software-decoded IRQs.
* @irq: the interrupt number
@@ -382,7 +449,10 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc)
spin_lock(&desc->lock);
desc->status &= ~IRQ_INPROGRESS;
- if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
+
+ if (unlikely(desc->status & IRQ_ONESHOT))
+ desc->status |= IRQ_MASKED;
+ else if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
desc->chip->unmask(irq);
out_unlock:
spin_unlock(&desc->lock);
@@ -572,6 +642,7 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
desc->chip = &dummy_irq_chip;
}
+ chip_bus_lock(irq, desc);
spin_lock_irqsave(&desc->lock, flags);
/* Uninstall? */
@@ -591,6 +662,7 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
desc->chip->startup(irq);
}
spin_unlock_irqrestore(&desc->lock, flags);
+ chip_bus_sync_unlock(irq, desc);
}
EXPORT_SYMBOL_GPL(__set_irq_handler);
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 065205bdd920..a81cf80554db 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -161,7 +161,7 @@ int __init early_irq_init(void)
desc = irq_desc_legacy;
legacy_count = ARRAY_SIZE(irq_desc_legacy);
- node = first_online_node;
+ node = first_online_node;
/* allocate irq_desc_ptrs array based on nr_irqs */
irq_desc_ptrs = kcalloc(nr_irqs, sizeof(void *), GFP_NOWAIT);
@@ -172,6 +172,9 @@ int __init early_irq_init(void)
for (i = 0; i < legacy_count; i++) {
desc[i].irq = i;
+#ifdef CONFIG_SMP
+ desc[i].node = node;
+#endif
desc[i].kstat_irqs = kstat_irqs_legacy + i * nr_cpu_ids;
lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
alloc_desc_masks(&desc[i], node, true);
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index e70ed5592eb9..1b5d742c6a77 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -44,6 +44,19 @@ extern int irq_select_affinity_usr(unsigned int irq);
extern void irq_set_thread_affinity(struct irq_desc *desc);
+/* Inline functions for support of irq chips on slow busses */
+static inline void chip_bus_lock(unsigned int irq, struct irq_desc *desc)
+{
+ if (unlikely(desc->chip->bus_lock))
+ desc->chip->bus_lock(irq);
+}
+
+static inline void chip_bus_sync_unlock(unsigned int irq, struct irq_desc *desc)
+{
+ if (unlikely(desc->chip->bus_sync_unlock))
+ desc->chip->bus_sync_unlock(irq);
+}
+
/*
* Debugging printout:
*/
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 0ec9ed831737..bde4c667d24d 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -230,9 +230,11 @@ void disable_irq_nosync(unsigned int irq)
if (!desc)
return;
+ chip_bus_lock(irq, desc);
spin_lock_irqsave(&desc->lock, flags);
__disable_irq(desc, irq, false);
spin_unlock_irqrestore(&desc->lock, flags);
+ chip_bus_sync_unlock(irq, desc);
}
EXPORT_SYMBOL(disable_irq_nosync);
@@ -294,7 +296,8 @@ void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
* matches the last disable, processing of interrupts on this
* IRQ line is re-enabled.
*
- * This function may be called from IRQ context.
+ * This function may be called from IRQ context only when
+ * desc->chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
*/
void enable_irq(unsigned int irq)
{
@@ -304,9 +307,11 @@ void enable_irq(unsigned int irq)
if (!desc)
return;
+ chip_bus_lock(irq, desc);
spin_lock_irqsave(&desc->lock, flags);
__enable_irq(desc, irq, false);
spin_unlock_irqrestore(&desc->lock, flags);
+ chip_bus_sync_unlock(irq, desc);
}
EXPORT_SYMBOL(enable_irq);
@@ -436,6 +441,26 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
return ret;
}
+/*
+ * Default primary interrupt handler for threaded interrupts. Is
+ * assigned as primary handler when request_threaded_irq is called
+ * with handler == NULL. Useful for oneshot interrupts.
+ */
+static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
+{
+ return IRQ_WAKE_THREAD;
+}
+
+/*
+ * Primary handler for nested threaded interrupts. Should never be
+ * called.
+ */
+static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
+{
+ WARN(1, "Primary handler called for nested irq %d\n", irq);
+ return IRQ_NONE;
+}
+
static int irq_wait_for_interrupt(struct irqaction *action)
{
while (!kthread_should_stop()) {
@@ -451,6 +476,23 @@ static int irq_wait_for_interrupt(struct irqaction *action)
return -1;
}
+/*
+ * Oneshot interrupts keep the irq line masked until the threaded
+ * handler finished. unmask if the interrupt has not been disabled and
+ * is marked MASKED.
+ */
+static void irq_finalize_oneshot(unsigned int irq, struct irq_desc *desc)
+{
+ chip_bus_lock(irq, desc);
+ spin_lock_irq(&desc->lock);
+ if (!(desc->status & IRQ_DISABLED) && (desc->status & IRQ_MASKED)) {
+ desc->status &= ~IRQ_MASKED;
+ desc->chip->unmask(irq);
+ }
+ spin_unlock_irq(&desc->lock);
+ chip_bus_sync_unlock(irq, desc);
+}
+
#ifdef CONFIG_SMP
/*
* Check whether we need to change the affinity of the interrupt thread.
@@ -492,7 +534,7 @@ static int irq_thread(void *data)
struct sched_param param = { .sched_priority = MAX_USER_RT_PRIO/2, };
struct irqaction *action = data;
struct irq_desc *desc = irq_to_desc(action->irq);
- int wake;
+ int wake, oneshot = desc->status & IRQ_ONESHOT;
sched_setscheduler(current, SCHED_FIFO, &param);
current->irqaction = action;
@@ -518,6 +560,9 @@ static int irq_thread(void *data)
spin_unlock_irq(&desc->lock);
action->thread_fn(action->irq, action->dev_id);
+
+ if (oneshot)
+ irq_finalize_oneshot(action->irq, desc);
}
wake = atomic_dec_and_test(&desc->threads_active);
@@ -565,7 +610,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
struct irqaction *old, **old_ptr;
const char *old_name = NULL;
unsigned long flags;
- int shared = 0;
+ int nested, shared = 0;
int ret;
if (!desc)
@@ -590,10 +635,32 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
rand_initialize_irq(irq);
}
+ /* Oneshot interrupts are not allowed with shared */
+ if ((new->flags & IRQF_ONESHOT) && (new->flags & IRQF_SHARED))
+ return -EINVAL;
+
+ /*
+ * Check whether the interrupt nests into another interrupt
+ * thread.
+ */
+ nested = desc->status & IRQ_NESTED_THREAD;
+ if (nested) {
+ if (!new->thread_fn)
+ return -EINVAL;
+ /*
+ * Replace the primary handler which was provided from
+ * the driver for non nested interrupt handling by the
+ * dummy function which warns when called.
+ */
+ new->handler = irq_nested_primary_handler;
+ }
+
/*
- * Threaded handler ?
+ * Create a handler thread when a thread function is supplied
+ * and the interrupt does not nest into another interrupt
+ * thread.
*/
- if (new->thread_fn) {
+ if (new->thread_fn && !nested) {
struct task_struct *t;
t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
@@ -662,9 +729,12 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
desc->status |= IRQ_PER_CPU;
#endif
- desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING |
+ desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | IRQ_ONESHOT |
IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED);
+ if (new->flags & IRQF_ONESHOT)
+ desc->status |= IRQ_ONESHOT;
+
if (!(desc->status & IRQ_NOAUTOEN)) {
desc->depth = 0;
desc->status &= ~IRQ_DISABLED;
@@ -875,7 +945,14 @@ EXPORT_SYMBOL_GPL(remove_irq);
*/
void free_irq(unsigned int irq, void *dev_id)
{
+ struct irq_desc *desc = irq_to_desc(irq);
+
+ if (!desc)
+ return;
+
+ chip_bus_lock(irq, desc);
kfree(__free_irq(irq, dev_id));
+ chip_bus_sync_unlock(irq, desc);
}
EXPORT_SYMBOL(free_irq);
@@ -884,6 +961,8 @@ EXPORT_SYMBOL(free_irq);
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs.
* Primary handler for threaded interrupts
+ * If NULL and thread_fn != NULL the default
+ * primary handler is installed
* @thread_fn: Function called from the irq handler thread
* If NULL, no irq thread is created
* @irqflags: Interrupt type flags
@@ -963,8 +1042,12 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler,
if (desc->status & IRQ_NOREQUEST)
return -EINVAL;
- if (!handler)
- return -EINVAL;
+
+ if (!handler) {
+ if (!thread_fn)
+ return -EINVAL;
+ handler = irq_default_primary_handler;
+ }
action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
if (!action)
@@ -976,7 +1059,10 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler,
action->name = devname;
action->dev_id = dev_id;
+ chip_bus_lock(irq, desc);
retval = __setup_irq(irq, desc, action);
+ chip_bus_sync_unlock(irq, desc);
+
if (retval)
kfree(action);
diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
index 638d8bedec14..a0bb09e79867 100644
--- a/kernel/irq/pm.c
+++ b/kernel/irq/pm.c
@@ -15,10 +15,10 @@
/**
* suspend_device_irqs - disable all currently enabled interrupt lines
*
- * During system-wide suspend or hibernation device interrupts need to be
- * disabled at the chip level and this function is provided for this purpose.
- * It disables all interrupt lines that are enabled at the moment and sets the
- * IRQ_SUSPENDED flag for them.
+ * During system-wide suspend or hibernation device drivers need to be prevented
+ * from receiving interrupts and this function is provided for this purpose.
+ * It marks all interrupt lines in use, except for the timer ones, as disabled
+ * and sets the IRQ_SUSPENDED flag for each of them.
*/
void suspend_device_irqs(void)
{
diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c
index 89c7117acf2b..090c3763f3a2 100644
--- a/kernel/irq/resend.c
+++ b/kernel/irq/resend.c
@@ -70,8 +70,7 @@ void check_irq_resend(struct irq_desc *desc, unsigned int irq)
if ((status & (IRQ_LEVEL | IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
desc->status = (status & ~IRQ_PENDING) | IRQ_REPLAY;
- if (!desc->chip || !desc->chip->retrigger ||
- !desc->chip->retrigger(irq)) {
+ if (!desc->chip->retrigger || !desc->chip->retrigger(irq)) {
#ifdef CONFIG_HARDIRQS_SW_RESEND
/* Set it pending and activate the softirq: */
set_bit(irq, irqs_resend);
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 4d568294de3e..114e704760fe 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -297,7 +297,6 @@ static int __init irqfixup_setup(char *str)
__setup("irqfixup", irqfixup_setup);
module_param(irqfixup, int, 0644);
-MODULE_PARM_DESC("irqfixup", "0: No fixup, 1: irqfixup mode, 2: irqpoll mode");
static int __init irqpoll_setup(char *str)
{
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 385c31a1bdbf..9fcb53a11f87 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -37,6 +37,8 @@
#include <linux/suspend.h>
#include <asm/uaccess.h>
+#include <trace/events/module.h>
+
extern int max_threads;
static struct workqueue_struct *khelper_wq;
@@ -78,6 +80,10 @@ int __request_module(bool wait, const char *fmt, ...)
#define MAX_KMOD_CONCURRENT 50 /* Completely arbitrary value - KAO */
static int kmod_loop_msg;
+ ret = security_kernel_module_request();
+ if (ret)
+ return ret;
+
va_start(args, fmt);
ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args);
va_end(args);
@@ -108,6 +114,8 @@ int __request_module(bool wait, const char *fmt, ...)
return -ENOMEM;
}
+ trace_module_request(module_name, wait, _RET_IP_);
+
ret = call_usermodehelper(modprobe_path, argv, envp,
wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC);
atomic_dec(&kmod_concurrent);
@@ -462,6 +470,7 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info,
int retval = 0;
BUG_ON(atomic_read(&sub_info->cred->usage) != 1);
+ validate_creds(sub_info->cred);
helper_lock();
if (sub_info->path[0] == '\0')
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 0540948e29ab..ef177d653b2c 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -103,7 +103,7 @@ static struct kprobe_blackpoint kprobe_blacklist[] = {
#define INSNS_PER_PAGE (PAGE_SIZE/(MAX_INSN_SIZE * sizeof(kprobe_opcode_t)))
struct kprobe_insn_page {
- struct hlist_node hlist;
+ struct list_head list;
kprobe_opcode_t *insns; /* Page of instruction slots */
char slot_used[INSNS_PER_PAGE];
int nused;
@@ -117,7 +117,7 @@ enum kprobe_slot_state {
};
static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_pages */
-static struct hlist_head kprobe_insn_pages;
+static LIST_HEAD(kprobe_insn_pages);
static int kprobe_garbage_slots;
static int collect_garbage_slots(void);
@@ -152,10 +152,9 @@ loop_end:
static kprobe_opcode_t __kprobes *__get_insn_slot(void)
{
struct kprobe_insn_page *kip;
- struct hlist_node *pos;
retry:
- hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) {
+ list_for_each_entry(kip, &kprobe_insn_pages, list) {
if (kip->nused < INSNS_PER_PAGE) {
int i;
for (i = 0; i < INSNS_PER_PAGE; i++) {
@@ -189,8 +188,8 @@ static kprobe_opcode_t __kprobes *__get_insn_slot(void)
kfree(kip);
return NULL;
}
- INIT_HLIST_NODE(&kip->hlist);
- hlist_add_head(&kip->hlist, &kprobe_insn_pages);
+ INIT_LIST_HEAD(&kip->list);
+ list_add(&kip->list, &kprobe_insn_pages);
memset(kip->slot_used, SLOT_CLEAN, INSNS_PER_PAGE);
kip->slot_used[0] = SLOT_USED;
kip->nused = 1;
@@ -219,12 +218,8 @@ static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx)
* so as not to have to set it up again the
* next time somebody inserts a probe.
*/
- hlist_del(&kip->hlist);
- if (hlist_empty(&kprobe_insn_pages)) {
- INIT_HLIST_NODE(&kip->hlist);
- hlist_add_head(&kip->hlist,
- &kprobe_insn_pages);
- } else {
+ if (!list_is_singular(&kprobe_insn_pages)) {
+ list_del(&kip->list);
module_free(NULL, kip->insns);
kfree(kip);
}
@@ -235,14 +230,13 @@ static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx)
static int __kprobes collect_garbage_slots(void)
{
- struct kprobe_insn_page *kip;
- struct hlist_node *pos, *next;
+ struct kprobe_insn_page *kip, *next;
/* Ensure no-one is preepmted on the garbages */
if (check_safety())
return -EAGAIN;
- hlist_for_each_entry_safe(kip, pos, next, &kprobe_insn_pages, hlist) {
+ list_for_each_entry_safe(kip, next, &kprobe_insn_pages, list) {
int i;
if (kip->ngarbage == 0)
continue;
@@ -260,19 +254,17 @@ static int __kprobes collect_garbage_slots(void)
void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty)
{
struct kprobe_insn_page *kip;
- struct hlist_node *pos;
mutex_lock(&kprobe_insn_mutex);
- hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) {
+ list_for_each_entry(kip, &kprobe_insn_pages, list) {
if (kip->insns <= slot &&
slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) {
int i = (slot - kip->insns) / MAX_INSN_SIZE;
if (dirty) {
kip->slot_used[i] = SLOT_DIRTY;
kip->ngarbage++;
- } else {
+ } else
collect_one_slot(kip, i);
- }
break;
}
}
diff --git a/kernel/kthread.c b/kernel/kthread.c
index eb8751aa0418..5fe709982caa 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -16,8 +16,6 @@
#include <linux/mutex.h>
#include <trace/events/sched.h>
-#define KTHREAD_NICE_LEVEL (-5)
-
static DEFINE_SPINLOCK(kthread_create_lock);
static LIST_HEAD(kthread_create_list);
struct task_struct *kthreadd_task;
@@ -145,7 +143,6 @@ struct task_struct *kthread_create(int (*threadfn)(void *data),
* The kernel thread should not inherit these properties.
*/
sched_setscheduler_nocheck(create.result, SCHED_NORMAL, &param);
- set_user_nice(create.result, KTHREAD_NICE_LEVEL);
set_cpus_allowed_ptr(create.result, cpu_all_mask);
}
return create.result;
@@ -221,7 +218,6 @@ int kthreadd(void *unused)
/* Setup a clean context for our children to inherit. */
set_task_comm(tsk, "kthreadd");
ignore_signals(tsk);
- set_user_nice(tsk, KTHREAD_NICE_LEVEL);
set_cpus_allowed_ptr(tsk, cpu_all_mask);
set_mems_allowed(node_possible_map);
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 8bbeef996c76..f74d2d7aa605 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -42,6 +42,7 @@
#include <linux/hash.h>
#include <linux/ftrace.h>
#include <linux/stringify.h>
+#include <linux/bitops.h>
#include <asm/sections.h>
@@ -366,11 +367,21 @@ static int save_trace(struct stack_trace *trace)
save_stack_trace(trace);
+ /*
+ * Some daft arches put -1 at the end to indicate its a full trace.
+ *
+ * <rant> this is buggy anyway, since it takes a whole extra entry so a
+ * complete trace that maxes out the entries provided will be reported
+ * as incomplete, friggin useless </rant>
+ */
+ if (trace->entries[trace->nr_entries-1] == ULONG_MAX)
+ trace->nr_entries--;
+
trace->max_entries = trace->nr_entries;
nr_stack_trace_entries += trace->nr_entries;
- if (nr_stack_trace_entries == MAX_STACK_TRACE_ENTRIES) {
+ if (nr_stack_trace_entries >= MAX_STACK_TRACE_ENTRIES-1) {
if (!debug_locks_off_graph_unlock())
return 0;
@@ -388,20 +399,6 @@ unsigned int nr_hardirq_chains;
unsigned int nr_softirq_chains;
unsigned int nr_process_chains;
unsigned int max_lockdep_depth;
-unsigned int max_recursion_depth;
-
-static unsigned int lockdep_dependency_gen_id;
-
-static bool lockdep_dependency_visit(struct lock_class *source,
- unsigned int depth)
-{
- if (!depth)
- lockdep_dependency_gen_id++;
- if (source->dep_gen_id == lockdep_dependency_gen_id)
- return true;
- source->dep_gen_id = lockdep_dependency_gen_id;
- return false;
-}
#ifdef CONFIG_DEBUG_LOCKDEP
/*
@@ -431,11 +428,8 @@ atomic_t redundant_softirqs_on;
atomic_t redundant_softirqs_off;
atomic_t nr_unused_locks;
atomic_t nr_cyclic_checks;
-atomic_t nr_cyclic_check_recursions;
atomic_t nr_find_usage_forwards_checks;
-atomic_t nr_find_usage_forwards_recursions;
atomic_t nr_find_usage_backwards_checks;
-atomic_t nr_find_usage_backwards_recursions;
#endif
/*
@@ -551,58 +545,6 @@ static void lockdep_print_held_locks(struct task_struct *curr)
}
}
-static void print_lock_class_header(struct lock_class *class, int depth)
-{
- int bit;
-
- printk("%*s->", depth, "");
- print_lock_name(class);
- printk(" ops: %lu", class->ops);
- printk(" {\n");
-
- for (bit = 0; bit < LOCK_USAGE_STATES; bit++) {
- if (class->usage_mask & (1 << bit)) {
- int len = depth;
-
- len += printk("%*s %s", depth, "", usage_str[bit]);
- len += printk(" at:\n");
- print_stack_trace(class->usage_traces + bit, len);
- }
- }
- printk("%*s }\n", depth, "");
-
- printk("%*s ... key at: ",depth,"");
- print_ip_sym((unsigned long)class->key);
-}
-
-/*
- * printk all lock dependencies starting at <entry>:
- */
-static void __used
-print_lock_dependencies(struct lock_class *class, int depth)
-{
- struct lock_list *entry;
-
- if (lockdep_dependency_visit(class, depth))
- return;
-
- if (DEBUG_LOCKS_WARN_ON(depth >= 20))
- return;
-
- print_lock_class_header(class, depth);
-
- list_for_each_entry(entry, &class->locks_after, entry) {
- if (DEBUG_LOCKS_WARN_ON(!entry->class))
- return;
-
- print_lock_dependencies(entry->class, depth + 1);
-
- printk("%*s ... acquired at:\n",depth,"");
- print_stack_trace(&entry->trace, 2);
- printk("\n");
- }
-}
-
static void print_kernel_version(void)
{
printk("%s %.*s\n", init_utsname()->release,
@@ -898,22 +840,203 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this,
}
/*
+ * For good efficiency of modular, we use power of 2
+ */
+#define MAX_CIRCULAR_QUEUE_SIZE 4096UL
+#define CQ_MASK (MAX_CIRCULAR_QUEUE_SIZE-1)
+
+/*
+ * The circular_queue and helpers is used to implement the
+ * breadth-first search(BFS)algorithem, by which we can build
+ * the shortest path from the next lock to be acquired to the
+ * previous held lock if there is a circular between them.
+ */
+struct circular_queue {
+ unsigned long element[MAX_CIRCULAR_QUEUE_SIZE];
+ unsigned int front, rear;
+};
+
+static struct circular_queue lock_cq;
+
+unsigned int max_bfs_queue_depth;
+
+static unsigned int lockdep_dependency_gen_id;
+
+static inline void __cq_init(struct circular_queue *cq)
+{
+ cq->front = cq->rear = 0;
+ lockdep_dependency_gen_id++;
+}
+
+static inline int __cq_empty(struct circular_queue *cq)
+{
+ return (cq->front == cq->rear);
+}
+
+static inline int __cq_full(struct circular_queue *cq)
+{
+ return ((cq->rear + 1) & CQ_MASK) == cq->front;
+}
+
+static inline int __cq_enqueue(struct circular_queue *cq, unsigned long elem)
+{
+ if (__cq_full(cq))
+ return -1;
+
+ cq->element[cq->rear] = elem;
+ cq->rear = (cq->rear + 1) & CQ_MASK;
+ return 0;
+}
+
+static inline int __cq_dequeue(struct circular_queue *cq, unsigned long *elem)
+{
+ if (__cq_empty(cq))
+ return -1;
+
+ *elem = cq->element[cq->front];
+ cq->front = (cq->front + 1) & CQ_MASK;
+ return 0;
+}
+
+static inline unsigned int __cq_get_elem_count(struct circular_queue *cq)
+{
+ return (cq->rear - cq->front) & CQ_MASK;
+}
+
+static inline void mark_lock_accessed(struct lock_list *lock,
+ struct lock_list *parent)
+{
+ unsigned long nr;
+
+ nr = lock - list_entries;
+ WARN_ON(nr >= nr_list_entries);
+ lock->parent = parent;
+ lock->class->dep_gen_id = lockdep_dependency_gen_id;
+}
+
+static inline unsigned long lock_accessed(struct lock_list *lock)
+{
+ unsigned long nr;
+
+ nr = lock - list_entries;
+ WARN_ON(nr >= nr_list_entries);
+ return lock->class->dep_gen_id == lockdep_dependency_gen_id;
+}
+
+static inline struct lock_list *get_lock_parent(struct lock_list *child)
+{
+ return child->parent;
+}
+
+static inline int get_lock_depth(struct lock_list *child)
+{
+ int depth = 0;
+ struct lock_list *parent;
+
+ while ((parent = get_lock_parent(child))) {
+ child = parent;
+ depth++;
+ }
+ return depth;
+}
+
+static int __bfs(struct lock_list *source_entry,
+ void *data,
+ int (*match)(struct lock_list *entry, void *data),
+ struct lock_list **target_entry,
+ int forward)
+{
+ struct lock_list *entry;
+ struct list_head *head;
+ struct circular_queue *cq = &lock_cq;
+ int ret = 1;
+
+ if (match(source_entry, data)) {
+ *target_entry = source_entry;
+ ret = 0;
+ goto exit;
+ }
+
+ if (forward)
+ head = &source_entry->class->locks_after;
+ else
+ head = &source_entry->class->locks_before;
+
+ if (list_empty(head))
+ goto exit;
+
+ __cq_init(cq);
+ __cq_enqueue(cq, (unsigned long)source_entry);
+
+ while (!__cq_empty(cq)) {
+ struct lock_list *lock;
+
+ __cq_dequeue(cq, (unsigned long *)&lock);
+
+ if (!lock->class) {
+ ret = -2;
+ goto exit;
+ }
+
+ if (forward)
+ head = &lock->class->locks_after;
+ else
+ head = &lock->class->locks_before;
+
+ list_for_each_entry(entry, head, entry) {
+ if (!lock_accessed(entry)) {
+ unsigned int cq_depth;
+ mark_lock_accessed(entry, lock);
+ if (match(entry, data)) {
+ *target_entry = entry;
+ ret = 0;
+ goto exit;
+ }
+
+ if (__cq_enqueue(cq, (unsigned long)entry)) {
+ ret = -1;
+ goto exit;
+ }
+ cq_depth = __cq_get_elem_count(cq);
+ if (max_bfs_queue_depth < cq_depth)
+ max_bfs_queue_depth = cq_depth;
+ }
+ }
+ }
+exit:
+ return ret;
+}
+
+static inline int __bfs_forwards(struct lock_list *src_entry,
+ void *data,
+ int (*match)(struct lock_list *entry, void *data),
+ struct lock_list **target_entry)
+{
+ return __bfs(src_entry, data, match, target_entry, 1);
+
+}
+
+static inline int __bfs_backwards(struct lock_list *src_entry,
+ void *data,
+ int (*match)(struct lock_list *entry, void *data),
+ struct lock_list **target_entry)
+{
+ return __bfs(src_entry, data, match, target_entry, 0);
+
+}
+
+/*
* Recursive, forwards-direction lock-dependency checking, used for
* both noncyclic checking and for hardirq-unsafe/softirq-unsafe
* checking.
- *
- * (to keep the stackframe of the recursive functions small we
- * use these global variables, and we also mark various helper
- * functions as noinline.)
*/
-static struct held_lock *check_source, *check_target;
/*
* Print a dependency chain entry (this is only done when a deadlock
* has been detected):
*/
static noinline int
-print_circular_bug_entry(struct lock_list *target, unsigned int depth)
+print_circular_bug_entry(struct lock_list *target, int depth)
{
if (debug_locks_silent)
return 0;
@@ -930,11 +1053,13 @@ print_circular_bug_entry(struct lock_list *target, unsigned int depth)
* header first:
*/
static noinline int
-print_circular_bug_header(struct lock_list *entry, unsigned int depth)
+print_circular_bug_header(struct lock_list *entry, unsigned int depth,
+ struct held_lock *check_src,
+ struct held_lock *check_tgt)
{
struct task_struct *curr = current;
- if (!debug_locks_off_graph_unlock() || debug_locks_silent)
+ if (debug_locks_silent)
return 0;
printk("\n=======================================================\n");
@@ -943,9 +1068,9 @@ print_circular_bug_header(struct lock_list *entry, unsigned int depth)
printk( "-------------------------------------------------------\n");
printk("%s/%d is trying to acquire lock:\n",
curr->comm, task_pid_nr(curr));
- print_lock(check_source);
+ print_lock(check_src);
printk("\nbut task is already holding lock:\n");
- print_lock(check_target);
+ print_lock(check_tgt);
printk("\nwhich lock already depends on the new lock.\n\n");
printk("\nthe existing dependency chain (in reverse order) is:\n");
@@ -954,19 +1079,36 @@ print_circular_bug_header(struct lock_list *entry, unsigned int depth)
return 0;
}
-static noinline int print_circular_bug_tail(void)
+static inline int class_equal(struct lock_list *entry, void *data)
+{
+ return entry->class == data;
+}
+
+static noinline int print_circular_bug(struct lock_list *this,
+ struct lock_list *target,
+ struct held_lock *check_src,
+ struct held_lock *check_tgt)
{
struct task_struct *curr = current;
- struct lock_list this;
+ struct lock_list *parent;
+ int depth;
- if (debug_locks_silent)
+ if (!debug_locks_off_graph_unlock() || debug_locks_silent)
return 0;
- this.class = hlock_class(check_source);
- if (!save_trace(&this.trace))
+ if (!save_trace(&this->trace))
return 0;
- print_circular_bug_entry(&this, 0);
+ depth = get_lock_depth(target);
+
+ print_circular_bug_header(target, depth, check_src, check_tgt);
+
+ parent = get_lock_parent(target);
+
+ while (parent) {
+ print_circular_bug_entry(parent, --depth);
+ parent = get_lock_parent(parent);
+ }
printk("\nother info that might help us debug this:\n\n");
lockdep_print_held_locks(curr);
@@ -977,73 +1119,69 @@ static noinline int print_circular_bug_tail(void)
return 0;
}
-#define RECURSION_LIMIT 40
-
-static int noinline print_infinite_recursion_bug(void)
+static noinline int print_bfs_bug(int ret)
{
if (!debug_locks_off_graph_unlock())
return 0;
- WARN_ON(1);
+ WARN(1, "lockdep bfs error:%d\n", ret);
return 0;
}
-unsigned long __lockdep_count_forward_deps(struct lock_class *class,
- unsigned int depth)
+static int noop_count(struct lock_list *entry, void *data)
{
- struct lock_list *entry;
- unsigned long ret = 1;
+ (*(unsigned long *)data)++;
+ return 0;
+}
- if (lockdep_dependency_visit(class, depth))
- return 0;
+unsigned long __lockdep_count_forward_deps(struct lock_list *this)
+{
+ unsigned long count = 0;
+ struct lock_list *uninitialized_var(target_entry);
- /*
- * Recurse this class's dependency list:
- */
- list_for_each_entry(entry, &class->locks_after, entry)
- ret += __lockdep_count_forward_deps(entry->class, depth + 1);
+ __bfs_forwards(this, (void *)&count, noop_count, &target_entry);
- return ret;
+ return count;
}
-
unsigned long lockdep_count_forward_deps(struct lock_class *class)
{
unsigned long ret, flags;
+ struct lock_list this;
+
+ this.parent = NULL;
+ this.class = class;
local_irq_save(flags);
__raw_spin_lock(&lockdep_lock);
- ret = __lockdep_count_forward_deps(class, 0);
+ ret = __lockdep_count_forward_deps(&this);
__raw_spin_unlock(&lockdep_lock);
local_irq_restore(flags);
return ret;
}
-unsigned long __lockdep_count_backward_deps(struct lock_class *class,
- unsigned int depth)
+unsigned long __lockdep_count_backward_deps(struct lock_list *this)
{
- struct lock_list *entry;
- unsigned long ret = 1;
+ unsigned long count = 0;
+ struct lock_list *uninitialized_var(target_entry);
- if (lockdep_dependency_visit(class, depth))
- return 0;
- /*
- * Recurse this class's dependency list:
- */
- list_for_each_entry(entry, &class->locks_before, entry)
- ret += __lockdep_count_backward_deps(entry->class, depth + 1);
+ __bfs_backwards(this, (void *)&count, noop_count, &target_entry);
- return ret;
+ return count;
}
unsigned long lockdep_count_backward_deps(struct lock_class *class)
{
unsigned long ret, flags;
+ struct lock_list this;
+
+ this.parent = NULL;
+ this.class = class;
local_irq_save(flags);
__raw_spin_lock(&lockdep_lock);
- ret = __lockdep_count_backward_deps(class, 0);
+ ret = __lockdep_count_backward_deps(&this);
__raw_spin_unlock(&lockdep_lock);
local_irq_restore(flags);
@@ -1055,29 +1193,16 @@ unsigned long lockdep_count_backward_deps(struct lock_class *class)
* lead to <target>. Print an error and return 0 if it does.
*/
static noinline int
-check_noncircular(struct lock_class *source, unsigned int depth)
+check_noncircular(struct lock_list *root, struct lock_class *target,
+ struct lock_list **target_entry)
{
- struct lock_list *entry;
+ int result;
- if (lockdep_dependency_visit(source, depth))
- return 1;
+ debug_atomic_inc(&nr_cyclic_checks);
- debug_atomic_inc(&nr_cyclic_check_recursions);
- if (depth > max_recursion_depth)
- max_recursion_depth = depth;
- if (depth >= RECURSION_LIMIT)
- return print_infinite_recursion_bug();
- /*
- * Check this lock's dependency list:
- */
- list_for_each_entry(entry, &source->locks_after, entry) {
- if (entry->class == hlock_class(check_target))
- return print_circular_bug_header(entry, depth+1);
- debug_atomic_inc(&nr_cyclic_checks);
- if (!check_noncircular(entry->class, depth+1))
- return print_circular_bug_entry(entry, depth+1);
- }
- return 1;
+ result = __bfs_forwards(root, target, class_equal, target_entry);
+
+ return result;
}
#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING)
@@ -1086,103 +1211,121 @@ check_noncircular(struct lock_class *source, unsigned int depth)
* proving that two subgraphs can be connected by a new dependency
* without creating any illegal irq-safe -> irq-unsafe lock dependency.
*/
-static enum lock_usage_bit find_usage_bit;
-static struct lock_class *forwards_match, *backwards_match;
+
+static inline int usage_match(struct lock_list *entry, void *bit)
+{
+ return entry->class->usage_mask & (1 << (enum lock_usage_bit)bit);
+}
+
+
/*
* Find a node in the forwards-direction dependency sub-graph starting
- * at <source> that matches <find_usage_bit>.
+ * at @root->class that matches @bit.
*
- * Return 2 if such a node exists in the subgraph, and put that node
- * into <forwards_match>.
+ * Return 0 if such a node exists in the subgraph, and put that node
+ * into *@target_entry.
*
- * Return 1 otherwise and keep <forwards_match> unchanged.
- * Return 0 on error.
+ * Return 1 otherwise and keep *@target_entry unchanged.
+ * Return <0 on error.
*/
-static noinline int
-find_usage_forwards(struct lock_class *source, unsigned int depth)
+static int
+find_usage_forwards(struct lock_list *root, enum lock_usage_bit bit,
+ struct lock_list **target_entry)
{
- struct lock_list *entry;
- int ret;
-
- if (lockdep_dependency_visit(source, depth))
- return 1;
-
- if (depth > max_recursion_depth)
- max_recursion_depth = depth;
- if (depth >= RECURSION_LIMIT)
- return print_infinite_recursion_bug();
+ int result;
debug_atomic_inc(&nr_find_usage_forwards_checks);
- if (source->usage_mask & (1 << find_usage_bit)) {
- forwards_match = source;
- return 2;
- }
- /*
- * Check this lock's dependency list:
- */
- list_for_each_entry(entry, &source->locks_after, entry) {
- debug_atomic_inc(&nr_find_usage_forwards_recursions);
- ret = find_usage_forwards(entry->class, depth+1);
- if (ret == 2 || ret == 0)
- return ret;
- }
- return 1;
+ result = __bfs_forwards(root, (void *)bit, usage_match, target_entry);
+
+ return result;
}
/*
* Find a node in the backwards-direction dependency sub-graph starting
- * at <source> that matches <find_usage_bit>.
+ * at @root->class that matches @bit.
*
- * Return 2 if such a node exists in the subgraph, and put that node
- * into <backwards_match>.
+ * Return 0 if such a node exists in the subgraph, and put that node
+ * into *@target_entry.
*
- * Return 1 otherwise and keep <backwards_match> unchanged.
- * Return 0 on error.
+ * Return 1 otherwise and keep *@target_entry unchanged.
+ * Return <0 on error.
*/
-static noinline int
-find_usage_backwards(struct lock_class *source, unsigned int depth)
+static int
+find_usage_backwards(struct lock_list *root, enum lock_usage_bit bit,
+ struct lock_list **target_entry)
{
- struct lock_list *entry;
- int ret;
+ int result;
- if (lockdep_dependency_visit(source, depth))
- return 1;
+ debug_atomic_inc(&nr_find_usage_backwards_checks);
- if (!__raw_spin_is_locked(&lockdep_lock))
- return DEBUG_LOCKS_WARN_ON(1);
+ result = __bfs_backwards(root, (void *)bit, usage_match, target_entry);
- if (depth > max_recursion_depth)
- max_recursion_depth = depth;
- if (depth >= RECURSION_LIMIT)
- return print_infinite_recursion_bug();
+ return result;
+}
- debug_atomic_inc(&nr_find_usage_backwards_checks);
- if (source->usage_mask & (1 << find_usage_bit)) {
- backwards_match = source;
- return 2;
- }
+static void print_lock_class_header(struct lock_class *class, int depth)
+{
+ int bit;
- if (!source && debug_locks_off_graph_unlock()) {
- WARN_ON(1);
- return 0;
- }
+ printk("%*s->", depth, "");
+ print_lock_name(class);
+ printk(" ops: %lu", class->ops);
+ printk(" {\n");
- /*
- * Check this lock's dependency list:
- */
- list_for_each_entry(entry, &source->locks_before, entry) {
- debug_atomic_inc(&nr_find_usage_backwards_recursions);
- ret = find_usage_backwards(entry->class, depth+1);
- if (ret == 2 || ret == 0)
- return ret;
+ for (bit = 0; bit < LOCK_USAGE_STATES; bit++) {
+ if (class->usage_mask & (1 << bit)) {
+ int len = depth;
+
+ len += printk("%*s %s", depth, "", usage_str[bit]);
+ len += printk(" at:\n");
+ print_stack_trace(class->usage_traces + bit, len);
+ }
}
- return 1;
+ printk("%*s }\n", depth, "");
+
+ printk("%*s ... key at: ",depth,"");
+ print_ip_sym((unsigned long)class->key);
+}
+
+/*
+ * printk the shortest lock dependencies from @start to @end in reverse order:
+ */
+static void __used
+print_shortest_lock_dependencies(struct lock_list *leaf,
+ struct lock_list *root)
+{
+ struct lock_list *entry = leaf;
+ int depth;
+
+ /*compute depth from generated tree by BFS*/
+ depth = get_lock_depth(leaf);
+
+ do {
+ print_lock_class_header(entry->class, depth);
+ printk("%*s ... acquired at:\n", depth, "");
+ print_stack_trace(&entry->trace, 2);
+ printk("\n");
+
+ if (depth == 0 && (entry != root)) {
+ printk("lockdep:%s bad BFS generated tree\n", __func__);
+ break;
+ }
+
+ entry = get_lock_parent(entry);
+ depth--;
+ } while (entry && (depth >= 0));
+
+ return;
}
static int
print_bad_irq_dependency(struct task_struct *curr,
+ struct lock_list *prev_root,
+ struct lock_list *next_root,
+ struct lock_list *backwards_entry,
+ struct lock_list *forwards_entry,
struct held_lock *prev,
struct held_lock *next,
enum lock_usage_bit bit1,
@@ -1215,26 +1358,32 @@ print_bad_irq_dependency(struct task_struct *curr,
printk("\nbut this new dependency connects a %s-irq-safe lock:\n",
irqclass);
- print_lock_name(backwards_match);
+ print_lock_name(backwards_entry->class);
printk("\n... which became %s-irq-safe at:\n", irqclass);
- print_stack_trace(backwards_match->usage_traces + bit1, 1);
+ print_stack_trace(backwards_entry->class->usage_traces + bit1, 1);
printk("\nto a %s-irq-unsafe lock:\n", irqclass);
- print_lock_name(forwards_match);
+ print_lock_name(forwards_entry->class);
printk("\n... which became %s-irq-unsafe at:\n", irqclass);
printk("...");
- print_stack_trace(forwards_match->usage_traces + bit2, 1);
+ print_stack_trace(forwards_entry->class->usage_traces + bit2, 1);
printk("\nother info that might help us debug this:\n\n");
lockdep_print_held_locks(curr);
- printk("\nthe %s-irq-safe lock's dependencies:\n", irqclass);
- print_lock_dependencies(backwards_match, 0);
+ printk("\nthe dependencies between %s-irq-safe lock", irqclass);
+ printk(" and the holding lock:\n");
+ if (!save_trace(&prev_root->trace))
+ return 0;
+ print_shortest_lock_dependencies(backwards_entry, prev_root);
- printk("\nthe %s-irq-unsafe lock's dependencies:\n", irqclass);
- print_lock_dependencies(forwards_match, 0);
+ printk("\nthe dependencies between the lock to be acquired");
+ printk(" and %s-irq-unsafe lock:\n", irqclass);
+ if (!save_trace(&next_root->trace))
+ return 0;
+ print_shortest_lock_dependencies(forwards_entry, next_root);
printk("\nstack backtrace:\n");
dump_stack();
@@ -1248,19 +1397,30 @@ check_usage(struct task_struct *curr, struct held_lock *prev,
enum lock_usage_bit bit_forwards, const char *irqclass)
{
int ret;
+ struct lock_list this, that;
+ struct lock_list *uninitialized_var(target_entry);
+ struct lock_list *uninitialized_var(target_entry1);
- find_usage_bit = bit_backwards;
- /* fills in <backwards_match> */
- ret = find_usage_backwards(hlock_class(prev), 0);
- if (!ret || ret == 1)
+ this.parent = NULL;
+
+ this.class = hlock_class(prev);
+ ret = find_usage_backwards(&this, bit_backwards, &target_entry);
+ if (ret < 0)
+ return print_bfs_bug(ret);
+ if (ret == 1)
return ret;
- find_usage_bit = bit_forwards;
- ret = find_usage_forwards(hlock_class(next), 0);
- if (!ret || ret == 1)
+ that.parent = NULL;
+ that.class = hlock_class(next);
+ ret = find_usage_forwards(&that, bit_forwards, &target_entry1);
+ if (ret < 0)
+ return print_bfs_bug(ret);
+ if (ret == 1)
return ret;
- /* ret == 2 */
- return print_bad_irq_dependency(curr, prev, next,
+
+ return print_bad_irq_dependency(curr, &this, &that,
+ target_entry, target_entry1,
+ prev, next,
bit_backwards, bit_forwards, irqclass);
}
@@ -1472,6 +1632,8 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
{
struct lock_list *entry;
int ret;
+ struct lock_list this;
+ struct lock_list *uninitialized_var(target_entry);
/*
* Prove that the new <prev> -> <next> dependency would not
@@ -1482,10 +1644,13 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
* We are using global variables to control the recursion, to
* keep the stackframe size of the recursive functions low:
*/
- check_source = next;
- check_target = prev;
- if (!(check_noncircular(hlock_class(next), 0)))
- return print_circular_bug_tail();
+ this.class = hlock_class(next);
+ this.parent = NULL;
+ ret = check_noncircular(&this, hlock_class(prev), &target_entry);
+ if (unlikely(!ret))
+ return print_circular_bug(&this, target_entry, next, prev);
+ else if (unlikely(ret < 0))
+ return print_bfs_bug(ret);
if (!check_prev_add_irq(curr, prev, next))
return 0;
@@ -1884,7 +2049,8 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
* print irq inversion bug:
*/
static int
-print_irq_inversion_bug(struct task_struct *curr, struct lock_class *other,
+print_irq_inversion_bug(struct task_struct *curr,
+ struct lock_list *root, struct lock_list *other,
struct held_lock *this, int forwards,
const char *irqclass)
{
@@ -1902,17 +2068,16 @@ print_irq_inversion_bug(struct task_struct *curr, struct lock_class *other,
printk("but this lock took another, %s-unsafe lock in the past:\n", irqclass);
else
printk("but this lock was taken by another, %s-safe lock in the past:\n", irqclass);
- print_lock_name(other);
+ print_lock_name(other->class);
printk("\n\nand interrupts could create inverse lock ordering between them.\n\n");
printk("\nother info that might help us debug this:\n");
lockdep_print_held_locks(curr);
- printk("\nthe first lock's dependencies:\n");
- print_lock_dependencies(hlock_class(this), 0);
-
- printk("\nthe second lock's dependencies:\n");
- print_lock_dependencies(other, 0);
+ printk("\nthe shortest dependencies between 2nd lock and 1st lock:\n");
+ if (!save_trace(&root->trace))
+ return 0;
+ print_shortest_lock_dependencies(other, root);
printk("\nstack backtrace:\n");
dump_stack();
@@ -1929,14 +2094,19 @@ check_usage_forwards(struct task_struct *curr, struct held_lock *this,
enum lock_usage_bit bit, const char *irqclass)
{
int ret;
-
- find_usage_bit = bit;
- /* fills in <forwards_match> */
- ret = find_usage_forwards(hlock_class(this), 0);
- if (!ret || ret == 1)
+ struct lock_list root;
+ struct lock_list *uninitialized_var(target_entry);
+
+ root.parent = NULL;
+ root.class = hlock_class(this);
+ ret = find_usage_forwards(&root, bit, &target_entry);
+ if (ret < 0)
+ return print_bfs_bug(ret);
+ if (ret == 1)
return ret;
- return print_irq_inversion_bug(curr, forwards_match, this, 1, irqclass);
+ return print_irq_inversion_bug(curr, &root, target_entry,
+ this, 1, irqclass);
}
/*
@@ -1948,14 +2118,19 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this,
enum lock_usage_bit bit, const char *irqclass)
{
int ret;
-
- find_usage_bit = bit;
- /* fills in <backwards_match> */
- ret = find_usage_backwards(hlock_class(this), 0);
- if (!ret || ret == 1)
+ struct lock_list root;
+ struct lock_list *uninitialized_var(target_entry);
+
+ root.parent = NULL;
+ root.class = hlock_class(this);
+ ret = find_usage_backwards(&root, bit, &target_entry);
+ if (ret < 0)
+ return print_bfs_bug(ret);
+ if (ret == 1)
return ret;
- return print_irq_inversion_bug(curr, backwards_match, this, 0, irqclass);
+ return print_irq_inversion_bug(curr, &root, target_entry,
+ this, 1, irqclass);
}
void print_irqtrace_events(struct task_struct *curr)
@@ -2530,13 +2705,15 @@ EXPORT_SYMBOL_GPL(lockdep_init_map);
*/
static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
int trylock, int read, int check, int hardirqs_off,
- struct lockdep_map *nest_lock, unsigned long ip)
+ struct lockdep_map *nest_lock, unsigned long ip,
+ int references)
{
struct task_struct *curr = current;
struct lock_class *class = NULL;
struct held_lock *hlock;
unsigned int depth, id;
int chain_head = 0;
+ int class_idx;
u64 chain_key;
if (!prove_locking)
@@ -2584,10 +2761,24 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
if (DEBUG_LOCKS_WARN_ON(depth >= MAX_LOCK_DEPTH))
return 0;
+ class_idx = class - lock_classes + 1;
+
+ if (depth) {
+ hlock = curr->held_locks + depth - 1;
+ if (hlock->class_idx == class_idx && nest_lock) {
+ if (hlock->references)
+ hlock->references++;
+ else
+ hlock->references = 2;
+
+ return 1;
+ }
+ }
+
hlock = curr->held_locks + depth;
if (DEBUG_LOCKS_WARN_ON(!class))
return 0;
- hlock->class_idx = class - lock_classes + 1;
+ hlock->class_idx = class_idx;
hlock->acquire_ip = ip;
hlock->instance = lock;
hlock->nest_lock = nest_lock;
@@ -2595,6 +2786,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
hlock->read = read;
hlock->check = check;
hlock->hardirqs_off = !!hardirqs_off;
+ hlock->references = references;
#ifdef CONFIG_LOCK_STAT
hlock->waittime_stamp = 0;
hlock->holdtime_stamp = sched_clock();
@@ -2703,6 +2895,30 @@ static int check_unlock(struct task_struct *curr, struct lockdep_map *lock,
return 1;
}
+static int match_held_lock(struct held_lock *hlock, struct lockdep_map *lock)
+{
+ if (hlock->instance == lock)
+ return 1;
+
+ if (hlock->references) {
+ struct lock_class *class = lock->class_cache;
+
+ if (!class)
+ class = look_up_lock_class(lock, 0);
+
+ if (DEBUG_LOCKS_WARN_ON(!class))
+ return 0;
+
+ if (DEBUG_LOCKS_WARN_ON(!hlock->nest_lock))
+ return 0;
+
+ if (hlock->class_idx == class - lock_classes + 1)
+ return 1;
+ }
+
+ return 0;
+}
+
static int
__lock_set_class(struct lockdep_map *lock, const char *name,
struct lock_class_key *key, unsigned int subclass,
@@ -2726,7 +2942,7 @@ __lock_set_class(struct lockdep_map *lock, const char *name,
*/
if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
break;
- if (hlock->instance == lock)
+ if (match_held_lock(hlock, lock))
goto found_it;
prev_hlock = hlock;
}
@@ -2745,7 +2961,8 @@ found_it:
if (!__lock_acquire(hlock->instance,
hlock_class(hlock)->subclass, hlock->trylock,
hlock->read, hlock->check, hlock->hardirqs_off,
- hlock->nest_lock, hlock->acquire_ip))
+ hlock->nest_lock, hlock->acquire_ip,
+ hlock->references))
return 0;
}
@@ -2784,20 +3001,34 @@ lock_release_non_nested(struct task_struct *curr,
*/
if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
break;
- if (hlock->instance == lock)
+ if (match_held_lock(hlock, lock))
goto found_it;
prev_hlock = hlock;
}
return print_unlock_inbalance_bug(curr, lock, ip);
found_it:
- lock_release_holdtime(hlock);
+ if (hlock->instance == lock)
+ lock_release_holdtime(hlock);
+
+ if (hlock->references) {
+ hlock->references--;
+ if (hlock->references) {
+ /*
+ * We had, and after removing one, still have
+ * references, the current lock stack is still
+ * valid. We're done!
+ */
+ return 1;
+ }
+ }
/*
* We have the right lock to unlock, 'hlock' points to it.
* Now we remove it from the stack, and add back the other
* entries (if any), recalculating the hash along the way:
*/
+
curr->lockdep_depth = i;
curr->curr_chain_key = hlock->prev_chain_key;
@@ -2806,7 +3037,8 @@ found_it:
if (!__lock_acquire(hlock->instance,
hlock_class(hlock)->subclass, hlock->trylock,
hlock->read, hlock->check, hlock->hardirqs_off,
- hlock->nest_lock, hlock->acquire_ip))
+ hlock->nest_lock, hlock->acquire_ip,
+ hlock->references))
return 0;
}
@@ -2836,7 +3068,7 @@ static int lock_release_nested(struct task_struct *curr,
/*
* Is the unlock non-nested:
*/
- if (hlock->instance != lock)
+ if (hlock->instance != lock || hlock->references)
return lock_release_non_nested(curr, lock, ip);
curr->lockdep_depth--;
@@ -2881,6 +3113,21 @@ __lock_release(struct lockdep_map *lock, int nested, unsigned long ip)
check_chain_key(curr);
}
+static int __lock_is_held(struct lockdep_map *lock)
+{
+ struct task_struct *curr = current;
+ int i;
+
+ for (i = 0; i < curr->lockdep_depth; i++) {
+ struct held_lock *hlock = curr->held_locks + i;
+
+ if (match_held_lock(hlock, lock))
+ return 1;
+ }
+
+ return 0;
+}
+
/*
* Check whether we follow the irq-flags state precisely:
*/
@@ -2957,7 +3204,7 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
current->lockdep_recursion = 1;
__lock_acquire(lock, subclass, trylock, read, check,
- irqs_disabled_flags(flags), nest_lock, ip);
+ irqs_disabled_flags(flags), nest_lock, ip, 0);
current->lockdep_recursion = 0;
raw_local_irq_restore(flags);
}
@@ -2982,6 +3229,26 @@ void lock_release(struct lockdep_map *lock, int nested,
}
EXPORT_SYMBOL_GPL(lock_release);
+int lock_is_held(struct lockdep_map *lock)
+{
+ unsigned long flags;
+ int ret = 0;
+
+ if (unlikely(current->lockdep_recursion))
+ return ret;
+
+ raw_local_irq_save(flags);
+ check_flags(flags);
+
+ current->lockdep_recursion = 1;
+ ret = __lock_is_held(lock);
+ current->lockdep_recursion = 0;
+ raw_local_irq_restore(flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(lock_is_held);
+
void lockdep_set_current_reclaim_state(gfp_t gfp_mask)
{
current->lockdep_reclaim_gfp = gfp_mask;
@@ -3041,7 +3308,7 @@ __lock_contended(struct lockdep_map *lock, unsigned long ip)
*/
if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
break;
- if (hlock->instance == lock)
+ if (match_held_lock(hlock, lock))
goto found_it;
prev_hlock = hlock;
}
@@ -3049,6 +3316,9 @@ __lock_contended(struct lockdep_map *lock, unsigned long ip)
return;
found_it:
+ if (hlock->instance != lock)
+ return;
+
hlock->waittime_stamp = sched_clock();
contention_point = lock_point(hlock_class(hlock)->contention_point, ip);
@@ -3088,7 +3358,7 @@ __lock_acquired(struct lockdep_map *lock, unsigned long ip)
*/
if (prev_hlock && prev_hlock->irq_context != hlock->irq_context)
break;
- if (hlock->instance == lock)
+ if (match_held_lock(hlock, lock))
goto found_it;
prev_hlock = hlock;
}
@@ -3096,6 +3366,9 @@ __lock_acquired(struct lockdep_map *lock, unsigned long ip)
return;
found_it:
+ if (hlock->instance != lock)
+ return;
+
cpu = smp_processor_id();
if (hlock->waittime_stamp) {
now = sched_clock();
@@ -3326,7 +3599,12 @@ void __init lockdep_info(void)
sizeof(struct list_head) * CLASSHASH_SIZE +
sizeof(struct lock_list) * MAX_LOCKDEP_ENTRIES +
sizeof(struct lock_chain) * MAX_LOCKDEP_CHAINS +
- sizeof(struct list_head) * CHAINHASH_SIZE) / 1024);
+ sizeof(struct list_head) * CHAINHASH_SIZE
+#ifdef CONFIG_PROVE_LOCKING
+ + sizeof(struct circular_queue)
+#endif
+ ) / 1024
+ );
printk(" per task-struct memory footprint: %lu bytes\n",
sizeof(struct held_lock) * MAX_LOCK_DEPTH);
diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h
index 699a2ac3a0d7..a2ee95ad1313 100644
--- a/kernel/lockdep_internals.h
+++ b/kernel/lockdep_internals.h
@@ -91,6 +91,8 @@ extern unsigned int nr_process_chains;
extern unsigned int max_lockdep_depth;
extern unsigned int max_recursion_depth;
+extern unsigned int max_bfs_queue_depth;
+
#ifdef CONFIG_PROVE_LOCKING
extern unsigned long lockdep_count_forward_deps(struct lock_class *);
extern unsigned long lockdep_count_backward_deps(struct lock_class *);
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index e94caa666dba..d4b3dbc79fdb 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -25,38 +25,12 @@
static void *l_next(struct seq_file *m, void *v, loff_t *pos)
{
- struct lock_class *class;
-
- (*pos)++;
-
- if (v == SEQ_START_TOKEN)
- class = m->private;
- else {
- class = v;
-
- if (class->lock_entry.next != &all_lock_classes)
- class = list_entry(class->lock_entry.next,
- struct lock_class, lock_entry);
- else
- class = NULL;
- }
-
- return class;
+ return seq_list_next(v, &all_lock_classes, pos);
}
static void *l_start(struct seq_file *m, loff_t *pos)
{
- struct lock_class *class;
- loff_t i = 0;
-
- if (*pos == 0)
- return SEQ_START_TOKEN;
-
- list_for_each_entry(class, &all_lock_classes, lock_entry) {
- if (++i == *pos)
- return class;
- }
- return NULL;
+ return seq_list_start_head(&all_lock_classes, *pos);
}
static void l_stop(struct seq_file *m, void *v)
@@ -82,11 +56,11 @@ static void print_name(struct seq_file *m, struct lock_class *class)
static int l_show(struct seq_file *m, void *v)
{
- struct lock_class *class = v;
+ struct lock_class *class = list_entry(v, struct lock_class, lock_entry);
struct lock_list *entry;
char usage[LOCK_USAGE_CHARS];
- if (v == SEQ_START_TOKEN) {
+ if (v == &all_lock_classes) {
seq_printf(m, "all lock classes:\n");
return 0;
}
@@ -128,17 +102,7 @@ static const struct seq_operations lockdep_ops = {
static int lockdep_open(struct inode *inode, struct file *file)
{
- int res = seq_open(file, &lockdep_ops);
- if (!res) {
- struct seq_file *m = file->private_data;
-
- if (!list_empty(&all_lock_classes))
- m->private = list_entry(all_lock_classes.next,
- struct lock_class, lock_entry);
- else
- m->private = NULL;
- }
- return res;
+ return seq_open(file, &lockdep_ops);
}
static const struct file_operations proc_lockdep_operations = {
@@ -149,37 +113,23 @@ static const struct file_operations proc_lockdep_operations = {
};
#ifdef CONFIG_PROVE_LOCKING
-static void *lc_next(struct seq_file *m, void *v, loff_t *pos)
-{
- struct lock_chain *chain;
-
- (*pos)++;
-
- if (v == SEQ_START_TOKEN)
- chain = m->private;
- else {
- chain = v;
-
- if (*pos < nr_lock_chains)
- chain = lock_chains + *pos;
- else
- chain = NULL;
- }
-
- return chain;
-}
-
static void *lc_start(struct seq_file *m, loff_t *pos)
{
if (*pos == 0)
return SEQ_START_TOKEN;
- if (*pos < nr_lock_chains)
- return lock_chains + *pos;
+ if (*pos - 1 < nr_lock_chains)
+ return lock_chains + (*pos - 1);
return NULL;
}
+static void *lc_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ (*pos)++;
+ return lc_start(m, pos);
+}
+
static void lc_stop(struct seq_file *m, void *v)
{
}
@@ -220,16 +170,7 @@ static const struct seq_operations lockdep_chains_ops = {
static int lockdep_chains_open(struct inode *inode, struct file *file)
{
- int res = seq_open(file, &lockdep_chains_ops);
- if (!res) {
- struct seq_file *m = file->private_data;
-
- if (nr_lock_chains)
- m->private = lock_chains;
- else
- m->private = NULL;
- }
- return res;
+ return seq_open(file, &lockdep_chains_ops);
}
static const struct file_operations proc_lockdep_chains_operations = {
@@ -258,16 +199,10 @@ static void lockdep_stats_debug_show(struct seq_file *m)
debug_atomic_read(&chain_lookup_hits));
seq_printf(m, " cyclic checks: %11u\n",
debug_atomic_read(&nr_cyclic_checks));
- seq_printf(m, " cyclic-check recursions: %11u\n",
- debug_atomic_read(&nr_cyclic_check_recursions));
seq_printf(m, " find-mask forwards checks: %11u\n",
debug_atomic_read(&nr_find_usage_forwards_checks));
- seq_printf(m, " find-mask forwards recursions: %11u\n",
- debug_atomic_read(&nr_find_usage_forwards_recursions));
seq_printf(m, " find-mask backwards checks: %11u\n",
debug_atomic_read(&nr_find_usage_backwards_checks));
- seq_printf(m, " find-mask backwards recursions:%11u\n",
- debug_atomic_read(&nr_find_usage_backwards_recursions));
seq_printf(m, " hardirq on events: %11u\n", hi1);
seq_printf(m, " hardirq off events: %11u\n", hi2);
@@ -409,8 +344,10 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
nr_unused);
seq_printf(m, " max locking depth: %11u\n",
max_lockdep_depth);
- seq_printf(m, " max recursion depth: %11u\n",
- max_recursion_depth);
+#ifdef CONFIG_PROVE_LOCKING
+ seq_printf(m, " max bfs queue depth: %11u\n",
+ max_bfs_queue_depth);
+#endif
lockdep_stats_debug_show(m);
seq_printf(m, " debug_locks: %11u\n",
debug_locks);
@@ -438,7 +375,6 @@ struct lock_stat_data {
};
struct lock_stat_seq {
- struct lock_stat_data *iter;
struct lock_stat_data *iter_end;
struct lock_stat_data stats[MAX_LOCKDEP_KEYS];
};
@@ -626,34 +562,22 @@ static void seq_header(struct seq_file *m)
static void *ls_start(struct seq_file *m, loff_t *pos)
{
struct lock_stat_seq *data = m->private;
+ struct lock_stat_data *iter;
if (*pos == 0)
return SEQ_START_TOKEN;
- data->iter = data->stats + *pos;
- if (data->iter >= data->iter_end)
- data->iter = NULL;
+ iter = data->stats + (*pos - 1);
+ if (iter >= data->iter_end)
+ iter = NULL;
- return data->iter;
+ return iter;
}
static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
{
- struct lock_stat_seq *data = m->private;
-
(*pos)++;
-
- if (v == SEQ_START_TOKEN)
- data->iter = data->stats;
- else {
- data->iter = v;
- data->iter++;
- }
-
- if (data->iter == data->iter_end)
- data->iter = NULL;
-
- return data->iter;
+ return ls_start(m, pos);
}
static void ls_stop(struct seq_file *m, void *v)
@@ -691,7 +615,6 @@ static int lock_stat_open(struct inode *inode, struct file *file)
struct lock_stat_data *iter = data->stats;
struct seq_file *m = file->private_data;
- data->iter = iter;
list_for_each_entry(class, &all_lock_classes, lock_entry) {
iter->class = class;
iter->stats = lock_stats(class);
@@ -699,7 +622,7 @@ static int lock_stat_open(struct inode *inode, struct file *file)
}
data->iter_end = iter;
- sort(data->stats, data->iter_end - data->iter,
+ sort(data->stats, data->iter_end - data->stats,
sizeof(struct lock_stat_data),
lock_stat_cmp, NULL);
@@ -734,7 +657,6 @@ static int lock_stat_release(struct inode *inode, struct file *file)
struct seq_file *seq = file->private_data;
vfree(seq->private);
- seq->private = NULL;
return seq_release(inode, file);
}
diff --git a/kernel/module.c b/kernel/module.c
index 2d537186191f..46580edff0cb 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -55,6 +55,11 @@
#include <linux/percpu.h>
#include <linux/kmemleak.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/module.h>
+
+EXPORT_TRACEPOINT_SYMBOL(module_get);
+
#if 0
#define DEBUGP printk
#else
@@ -942,6 +947,8 @@ void module_put(struct module *module)
if (module) {
unsigned int cpu = get_cpu();
local_dec(__module_ref_addr(module, cpu));
+ trace_module_put(module, _RET_IP_,
+ local_read(__module_ref_addr(module, cpu)));
/* Maybe they're waiting for us to drop reference? */
if (unlikely(!module_is_live(module)))
wake_up_process(module->waiter);
@@ -1497,6 +1504,8 @@ static int __unlink_module(void *_mod)
/* Free a module, remove from lists, etc (must hold module_mutex). */
static void free_module(struct module *mod)
{
+ trace_module_free(mod);
+
/* Delete from various lists */
stop_machine(__unlink_module, mod, NULL);
remove_notes_attrs(mod);
@@ -2364,6 +2373,8 @@ static noinline struct module *load_module(void __user *umod,
/* Get rid of temporary copy */
vfree(hdr);
+ trace_module_load(mod);
+
/* Done! */
return mod;
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index d7cbc579fc80..e0d91fdf0c3c 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -46,12 +46,18 @@ static atomic_t nr_task_counters __read_mostly;
/*
* perf counter paranoia level:
- * 0 - not paranoid
- * 1 - disallow cpu counters to unpriv
- * 2 - disallow kernel profiling to unpriv
+ * -1 - not paranoid at all
+ * 0 - disallow raw tracepoint access for unpriv
+ * 1 - disallow cpu counters for unpriv
+ * 2 - disallow kernel profiling for unpriv
*/
int sysctl_perf_counter_paranoid __read_mostly = 1;
+static inline bool perf_paranoid_tracepoint_raw(void)
+{
+ return sysctl_perf_counter_paranoid > -1;
+}
+
static inline bool perf_paranoid_cpu(void)
{
return sysctl_perf_counter_paranoid > 0;
@@ -469,7 +475,8 @@ static void update_counter_times(struct perf_counter *counter)
struct perf_counter_context *ctx = counter->ctx;
u64 run_end;
- if (counter->state < PERF_COUNTER_STATE_INACTIVE)
+ if (counter->state < PERF_COUNTER_STATE_INACTIVE ||
+ counter->group_leader->state < PERF_COUNTER_STATE_INACTIVE)
return;
counter->total_time_enabled = ctx->time - counter->tstamp_enabled;
@@ -518,7 +525,7 @@ static void __perf_counter_disable(void *info)
*/
if (counter->state >= PERF_COUNTER_STATE_INACTIVE) {
update_context_time(ctx);
- update_counter_times(counter);
+ update_group_times(counter);
if (counter == counter->group_leader)
group_sched_out(counter, cpuctx, ctx);
else
@@ -573,7 +580,7 @@ static void perf_counter_disable(struct perf_counter *counter)
* in, so we can change the state safely.
*/
if (counter->state == PERF_COUNTER_STATE_INACTIVE) {
- update_counter_times(counter);
+ update_group_times(counter);
counter->state = PERF_COUNTER_STATE_OFF;
}
@@ -851,6 +858,27 @@ retry:
}
/*
+ * Put a counter into inactive state and update time fields.
+ * Enabling the leader of a group effectively enables all
+ * the group members that aren't explicitly disabled, so we
+ * have to update their ->tstamp_enabled also.
+ * Note: this works for group members as well as group leaders
+ * since the non-leader members' sibling_lists will be empty.
+ */
+static void __perf_counter_mark_enabled(struct perf_counter *counter,
+ struct perf_counter_context *ctx)
+{
+ struct perf_counter *sub;
+
+ counter->state = PERF_COUNTER_STATE_INACTIVE;
+ counter->tstamp_enabled = ctx->time - counter->total_time_enabled;
+ list_for_each_entry(sub, &counter->sibling_list, list_entry)
+ if (sub->state >= PERF_COUNTER_STATE_INACTIVE)
+ sub->tstamp_enabled =
+ ctx->time - sub->total_time_enabled;
+}
+
+/*
* Cross CPU call to enable a performance counter
*/
static void __perf_counter_enable(void *info)
@@ -877,8 +905,7 @@ static void __perf_counter_enable(void *info)
if (counter->state >= PERF_COUNTER_STATE_INACTIVE)
goto unlock;
- counter->state = PERF_COUNTER_STATE_INACTIVE;
- counter->tstamp_enabled = ctx->time - counter->total_time_enabled;
+ __perf_counter_mark_enabled(counter, ctx);
/*
* If the counter is in a group and isn't the group leader,
@@ -971,11 +998,9 @@ static void perf_counter_enable(struct perf_counter *counter)
* Since we have the lock this context can't be scheduled
* in, so we can change the state safely.
*/
- if (counter->state == PERF_COUNTER_STATE_OFF) {
- counter->state = PERF_COUNTER_STATE_INACTIVE;
- counter->tstamp_enabled =
- ctx->time - counter->total_time_enabled;
- }
+ if (counter->state == PERF_COUNTER_STATE_OFF)
+ __perf_counter_mark_enabled(counter, ctx);
+
out:
spin_unlock_irq(&ctx->lock);
}
@@ -1479,9 +1504,7 @@ static void perf_counter_enable_on_exec(struct task_struct *task)
counter->attr.enable_on_exec = 0;
if (counter->state >= PERF_COUNTER_STATE_INACTIVE)
continue;
- counter->state = PERF_COUNTER_STATE_INACTIVE;
- counter->tstamp_enabled =
- ctx->time - counter->total_time_enabled;
+ __perf_counter_mark_enabled(counter, ctx);
enabled = 1;
}
@@ -1675,6 +1698,11 @@ static void free_counter(struct perf_counter *counter)
atomic_dec(&nr_task_counters);
}
+ if (counter->output) {
+ fput(counter->output->filp);
+ counter->output = NULL;
+ }
+
if (counter->destroy)
counter->destroy(counter);
@@ -1960,6 +1988,8 @@ unlock:
return ret;
}
+int perf_counter_set_output(struct perf_counter *counter, int output_fd);
+
static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct perf_counter *counter = file->private_data;
@@ -1983,6 +2013,9 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case PERF_COUNTER_IOC_PERIOD:
return perf_counter_period(counter, (u64 __user *)arg);
+ case PERF_COUNTER_IOC_SET_OUTPUT:
+ return perf_counter_set_output(counter, arg);
+
default:
return -ENOTTY;
}
@@ -2253,6 +2286,11 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
WARN_ON_ONCE(counter->ctx->parent_ctx);
mutex_lock(&counter->mmap_mutex);
+ if (counter->output) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+
if (atomic_inc_not_zero(&counter->mmap_count)) {
if (nr_pages != counter->data->nr_pages)
ret = -EINVAL;
@@ -2638,6 +2676,7 @@ static int perf_output_begin(struct perf_output_handle *handle,
struct perf_counter *counter, unsigned int size,
int nmi, int sample)
{
+ struct perf_counter *output_counter;
struct perf_mmap_data *data;
unsigned int offset, head;
int have_lost;
@@ -2647,13 +2686,17 @@ static int perf_output_begin(struct perf_output_handle *handle,
u64 lost;
} lost_event;
+ rcu_read_lock();
/*
* For inherited counters we send all the output towards the parent.
*/
if (counter->parent)
counter = counter->parent;
- rcu_read_lock();
+ output_counter = rcu_dereference(counter->output);
+ if (output_counter)
+ counter = output_counter;
+
data = rcu_dereference(counter->data);
if (!data)
goto out;
@@ -3934,6 +3977,7 @@ static const struct pmu *tp_perf_counter_init(struct perf_counter *counter)
* have these.
*/
if ((counter->attr.sample_type & PERF_SAMPLE_RAW) &&
+ perf_paranoid_tracepoint_raw() &&
!capable(CAP_SYS_ADMIN))
return ERR_PTR(-EPERM);
@@ -4202,6 +4246,57 @@ err_size:
goto out;
}
+int perf_counter_set_output(struct perf_counter *counter, int output_fd)
+{
+ struct perf_counter *output_counter = NULL;
+ struct file *output_file = NULL;
+ struct perf_counter *old_output;
+ int fput_needed = 0;
+ int ret = -EINVAL;
+
+ if (!output_fd)
+ goto set;
+
+ output_file = fget_light(output_fd, &fput_needed);
+ if (!output_file)
+ return -EBADF;
+
+ if (output_file->f_op != &perf_fops)
+ goto out;
+
+ output_counter = output_file->private_data;
+
+ /* Don't chain output fds */
+ if (output_counter->output)
+ goto out;
+
+ /* Don't set an output fd when we already have an output channel */
+ if (counter->data)
+ goto out;
+
+ atomic_long_inc(&output_file->f_count);
+
+set:
+ mutex_lock(&counter->mmap_mutex);
+ old_output = counter->output;
+ rcu_assign_pointer(counter->output, output_counter);
+ mutex_unlock(&counter->mmap_mutex);
+
+ if (old_output) {
+ /*
+ * we need to make sure no existing perf_output_*()
+ * is still referencing this counter.
+ */
+ synchronize_rcu();
+ fput(old_output->filp);
+ }
+
+ ret = 0;
+out:
+ fput_light(output_file, fput_needed);
+ return ret;
+}
+
/**
* sys_perf_counter_open - open a performance counter, associate it to a task/cpu
*
@@ -4221,15 +4316,15 @@ SYSCALL_DEFINE5(perf_counter_open,
struct file *group_file = NULL;
int fput_needed = 0;
int fput_needed2 = 0;
- int ret;
+ int err;
/* for future expandability... */
- if (flags)
+ if (flags & ~(PERF_FLAG_FD_NO_GROUP | PERF_FLAG_FD_OUTPUT))
return -EINVAL;
- ret = perf_copy_attr(attr_uptr, &attr);
- if (ret)
- return ret;
+ err = perf_copy_attr(attr_uptr, &attr);
+ if (err)
+ return err;
if (!attr.exclude_kernel) {
if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
@@ -4252,8 +4347,8 @@ SYSCALL_DEFINE5(perf_counter_open,
* Look up the group leader (we will attach this counter to it):
*/
group_leader = NULL;
- if (group_fd != -1) {
- ret = -EINVAL;
+ if (group_fd != -1 && !(flags & PERF_FLAG_FD_NO_GROUP)) {
+ err = -EINVAL;
group_file = fget_light(group_fd, &fput_needed);
if (!group_file)
goto err_put_context;
@@ -4282,18 +4377,24 @@ SYSCALL_DEFINE5(perf_counter_open,
counter = perf_counter_alloc(&attr, cpu, ctx, group_leader,
NULL, GFP_KERNEL);
- ret = PTR_ERR(counter);
+ err = PTR_ERR(counter);
if (IS_ERR(counter))
goto err_put_context;
- ret = anon_inode_getfd("[perf_counter]", &perf_fops, counter, 0);
- if (ret < 0)
+ err = anon_inode_getfd("[perf_counter]", &perf_fops, counter, 0);
+ if (err < 0)
goto err_free_put_context;
- counter_file = fget_light(ret, &fput_needed2);
+ counter_file = fget_light(err, &fput_needed2);
if (!counter_file)
goto err_free_put_context;
+ if (flags & PERF_FLAG_FD_OUTPUT) {
+ err = perf_counter_set_output(counter, group_fd);
+ if (err)
+ goto err_fput_free_put_context;
+ }
+
counter->filp = counter_file;
WARN_ON_ONCE(ctx->parent_ctx);
mutex_lock(&ctx->mutex);
@@ -4307,20 +4408,20 @@ SYSCALL_DEFINE5(perf_counter_open,
list_add_tail(&counter->owner_entry, &current->perf_counter_list);
mutex_unlock(&current->perf_counter_mutex);
+err_fput_free_put_context:
fput_light(counter_file, fput_needed2);
-out_fput:
- fput_light(group_file, fput_needed);
-
- return ret;
-
err_free_put_context:
- kfree(counter);
+ if (err < 0)
+ kfree(counter);
err_put_context:
- put_ctx(ctx);
+ if (err < 0)
+ put_ctx(ctx);
+
+ fput_light(group_file, fput_needed);
- goto out_fput;
+ return err;
}
/*
diff --git a/kernel/printk.c b/kernel/printk.c
index b4d97b54c1ec..e10d193a833a 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -37,6 +37,12 @@
#include <asm/uaccess.h>
/*
+ * for_each_console() allows you to iterate on each console
+ */
+#define for_each_console(con) \
+ for (con = console_drivers; con != NULL; con = con->next)
+
+/*
* Architectures can override it:
*/
void asmlinkage __attribute__((weak)) early_printk(const char *fmt, ...)
@@ -61,6 +67,8 @@ int console_printk[4] = {
DEFAULT_CONSOLE_LOGLEVEL, /* default_console_loglevel */
};
+static int saved_console_loglevel = -1;
+
/*
* Low level drivers may need that to know if they can schedule in
* their unblank() callback or not. So let's export it.
@@ -372,10 +380,15 @@ int do_syslog(int type, char __user *buf, int len)
logged_chars = 0;
break;
case 6: /* Disable logging to console */
+ if (saved_console_loglevel == -1)
+ saved_console_loglevel = console_loglevel;
console_loglevel = minimum_console_loglevel;
break;
case 7: /* Enable logging to console */
- console_loglevel = default_console_loglevel;
+ if (saved_console_loglevel != -1) {
+ console_loglevel = saved_console_loglevel;
+ saved_console_loglevel = -1;
+ }
break;
case 8: /* Set level of messages printed to console */
error = -EINVAL;
@@ -384,6 +397,8 @@ int do_syslog(int type, char __user *buf, int len)
if (len < minimum_console_loglevel)
len = minimum_console_loglevel;
console_loglevel = len;
+ /* Implicitly re-enable logging to console */
+ saved_console_loglevel = -1;
error = 0;
break;
case 9: /* Number of chars in the log buffer */
@@ -412,7 +427,7 @@ static void __call_console_drivers(unsigned start, unsigned end)
{
struct console *con;
- for (con = console_drivers; con; con = con->next) {
+ for_each_console(con) {
if ((con->flags & CON_ENABLED) && con->write &&
(cpu_online(smp_processor_id()) ||
(con->flags & CON_ANYTIME)))
@@ -544,7 +559,7 @@ static int have_callable_console(void)
{
struct console *con;
- for (con = console_drivers; con; con = con->next)
+ for_each_console(con)
if (con->flags & CON_ANYTIME)
return 1;
@@ -1082,7 +1097,7 @@ void console_unblank(void)
console_locked = 1;
console_may_schedule = 0;
- for (c = console_drivers; c != NULL; c = c->next)
+ for_each_console(c)
if ((c->flags & CON_ENABLED) && c->unblank)
c->unblank();
release_console_sem();
@@ -1097,7 +1112,7 @@ struct tty_driver *console_device(int *index)
struct tty_driver *driver = NULL;
acquire_console_sem();
- for (c = console_drivers; c != NULL; c = c->next) {
+ for_each_console(c) {
if (!c->device)
continue;
driver = c->device(c, index);
@@ -1134,25 +1149,49 @@ EXPORT_SYMBOL(console_start);
* to register the console printing procedure with printk() and to
* print any messages that were printed by the kernel before the
* console driver was initialized.
+ *
+ * This can happen pretty early during the boot process (because of
+ * early_printk) - sometimes before setup_arch() completes - be careful
+ * of what kernel features are used - they may not be initialised yet.
+ *
+ * There are two types of consoles - bootconsoles (early_printk) and
+ * "real" consoles (everything which is not a bootconsole) which are
+ * handled differently.
+ * - Any number of bootconsoles can be registered at any time.
+ * - As soon as a "real" console is registered, all bootconsoles
+ * will be unregistered automatically.
+ * - Once a "real" console is registered, any attempt to register a
+ * bootconsoles will be rejected
*/
-void register_console(struct console *console)
+void register_console(struct console *newcon)
{
int i;
unsigned long flags;
- struct console *bootconsole = NULL;
+ struct console *bcon = NULL;
- if (console_drivers) {
- if (console->flags & CON_BOOT)
- return;
- if (console_drivers->flags & CON_BOOT)
- bootconsole = console_drivers;
+ /*
+ * before we register a new CON_BOOT console, make sure we don't
+ * already have a valid console
+ */
+ if (console_drivers && newcon->flags & CON_BOOT) {
+ /* find the last or real console */
+ for_each_console(bcon) {
+ if (!(bcon->flags & CON_BOOT)) {
+ printk(KERN_INFO "Too late to register bootconsole %s%d\n",
+ newcon->name, newcon->index);
+ return;
+ }
+ }
}
- if (preferred_console < 0 || bootconsole || !console_drivers)
+ if (console_drivers && console_drivers->flags & CON_BOOT)
+ bcon = console_drivers;
+
+ if (preferred_console < 0 || bcon || !console_drivers)
preferred_console = selected_console;
- if (console->early_setup)
- console->early_setup();
+ if (newcon->early_setup)
+ newcon->early_setup();
/*
* See if we want to use this console driver. If we
@@ -1160,13 +1199,13 @@ void register_console(struct console *console)
* that registers here.
*/
if (preferred_console < 0) {
- if (console->index < 0)
- console->index = 0;
- if (console->setup == NULL ||
- console->setup(console, NULL) == 0) {
- console->flags |= CON_ENABLED;
- if (console->device) {
- console->flags |= CON_CONSDEV;
+ if (newcon->index < 0)
+ newcon->index = 0;
+ if (newcon->setup == NULL ||
+ newcon->setup(newcon, NULL) == 0) {
+ newcon->flags |= CON_ENABLED;
+ if (newcon->device) {
+ newcon->flags |= CON_CONSDEV;
preferred_console = 0;
}
}
@@ -1178,64 +1217,62 @@ void register_console(struct console *console)
*/
for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0];
i++) {
- if (strcmp(console_cmdline[i].name, console->name) != 0)
+ if (strcmp(console_cmdline[i].name, newcon->name) != 0)
continue;
- if (console->index >= 0 &&
- console->index != console_cmdline[i].index)
+ if (newcon->index >= 0 &&
+ newcon->index != console_cmdline[i].index)
continue;
- if (console->index < 0)
- console->index = console_cmdline[i].index;
+ if (newcon->index < 0)
+ newcon->index = console_cmdline[i].index;
#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
if (console_cmdline[i].brl_options) {
- console->flags |= CON_BRL;
- braille_register_console(console,
+ newcon->flags |= CON_BRL;
+ braille_register_console(newcon,
console_cmdline[i].index,
console_cmdline[i].options,
console_cmdline[i].brl_options);
return;
}
#endif
- if (console->setup &&
- console->setup(console, console_cmdline[i].options) != 0)
+ if (newcon->setup &&
+ newcon->setup(newcon, console_cmdline[i].options) != 0)
break;
- console->flags |= CON_ENABLED;
- console->index = console_cmdline[i].index;
+ newcon->flags |= CON_ENABLED;
+ newcon->index = console_cmdline[i].index;
if (i == selected_console) {
- console->flags |= CON_CONSDEV;
+ newcon->flags |= CON_CONSDEV;
preferred_console = selected_console;
}
break;
}
- if (!(console->flags & CON_ENABLED))
+ if (!(newcon->flags & CON_ENABLED))
return;
- if (bootconsole && (console->flags & CON_CONSDEV)) {
- printk(KERN_INFO "console handover: boot [%s%d] -> real [%s%d]\n",
- bootconsole->name, bootconsole->index,
- console->name, console->index);
- unregister_console(bootconsole);
- console->flags &= ~CON_PRINTBUFFER;
- } else {
- printk(KERN_INFO "console [%s%d] enabled\n",
- console->name, console->index);
- }
+ /*
+ * If we have a bootconsole, and are switching to a real console,
+ * don't print everything out again, since when the boot console, and
+ * the real console are the same physical device, it's annoying to
+ * see the beginning boot messages twice
+ */
+ if (bcon && ((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV))
+ newcon->flags &= ~CON_PRINTBUFFER;
/*
* Put this console in the list - keep the
* preferred driver at the head of the list.
*/
acquire_console_sem();
- if ((console->flags & CON_CONSDEV) || console_drivers == NULL) {
- console->next = console_drivers;
- console_drivers = console;
- if (console->next)
- console->next->flags &= ~CON_CONSDEV;
+ if ((newcon->flags & CON_CONSDEV) || console_drivers == NULL) {
+ newcon->next = console_drivers;
+ console_drivers = newcon;
+ if (newcon->next)
+ newcon->next->flags &= ~CON_CONSDEV;
} else {
- console->next = console_drivers->next;
- console_drivers->next = console;
+ newcon->next = console_drivers->next;
+ console_drivers->next = newcon;
}
- if (console->flags & CON_PRINTBUFFER) {
+ if (newcon->flags & CON_PRINTBUFFER) {
/*
* release_console_sem() will print out the buffered messages
* for us.
@@ -1245,6 +1282,28 @@ void register_console(struct console *console)
spin_unlock_irqrestore(&logbuf_lock, flags);
}
release_console_sem();
+
+ /*
+ * By unregistering the bootconsoles after we enable the real console
+ * we get the "console xxx enabled" message on all the consoles -
+ * boot consoles, real consoles, etc - this is to ensure that end
+ * users know there might be something in the kernel's log buffer that
+ * went to the bootconsole (that they do not see on the real console)
+ */
+ if (bcon && ((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV)) {
+ /* we need to iterate through twice, to make sure we print
+ * everything out, before we unregister the console(s)
+ */
+ printk(KERN_INFO "console [%s%d] enabled, bootconsole disabled\n",
+ newcon->name, newcon->index);
+ for_each_console(bcon)
+ if (bcon->flags & CON_BOOT)
+ unregister_console(bcon);
+ } else {
+ printk(KERN_INFO "%sconsole [%s%d] enabled\n",
+ (newcon->flags & CON_BOOT) ? "boot" : "" ,
+ newcon->name, newcon->index);
+ }
}
EXPORT_SYMBOL(register_console);
@@ -1287,11 +1346,13 @@ EXPORT_SYMBOL(unregister_console);
static int __init disable_boot_consoles(void)
{
- if (console_drivers != NULL) {
- if (console_drivers->flags & CON_BOOT) {
+ struct console *con;
+
+ for_each_console(con) {
+ if (con->flags & CON_BOOT) {
printk(KERN_INFO "turn off boot console %s%d\n",
- console_drivers->name, console_drivers->index);
- return unregister_console(console_drivers);
+ con->name, con->index);
+ unregister_console(con);
}
}
return 0;
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 082c320e4dbf..307c285af59e 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -152,7 +152,7 @@ int __ptrace_may_access(struct task_struct *task, unsigned int mode)
if (!dumpable && !capable(CAP_SYS_PTRACE))
return -EPERM;
- return security_ptrace_may_access(task, mode);
+ return security_ptrace_access_check(task, mode);
}
bool ptrace_may_access(struct task_struct *task, unsigned int mode)
diff --git a/kernel/rcuclassic.c b/kernel/rcuclassic.c
deleted file mode 100644
index 0f2b0b311304..000000000000
--- a/kernel/rcuclassic.c
+++ /dev/null
@@ -1,807 +0,0 @@
-/*
- * Read-Copy Update mechanism for mutual exclusion
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *
- * Copyright IBM Corporation, 2001
- *
- * Authors: Dipankar Sarma <dipankar@in.ibm.com>
- * Manfred Spraul <manfred@colorfullife.com>
- *
- * Based on the original work by Paul McKenney <paulmck@us.ibm.com>
- * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
- * Papers:
- * http://www.rdrop.com/users/paulmck/paper/rclockpdcsproof.pdf
- * http://lse.sourceforge.net/locking/rclock_OLS.2001.05.01c.sc.pdf (OLS2001)
- *
- * For detailed explanation of Read-Copy Update mechanism see -
- * Documentation/RCU
- *
- */
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/spinlock.h>
-#include <linux/smp.h>
-#include <linux/rcupdate.h>
-#include <linux/interrupt.h>
-#include <linux/sched.h>
-#include <asm/atomic.h>
-#include <linux/bitops.h>
-#include <linux/module.h>
-#include <linux/completion.h>
-#include <linux/moduleparam.h>
-#include <linux/percpu.h>
-#include <linux/notifier.h>
-#include <linux/cpu.h>
-#include <linux/mutex.h>
-#include <linux/time.h>
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-static struct lock_class_key rcu_lock_key;
-struct lockdep_map rcu_lock_map =
- STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
-EXPORT_SYMBOL_GPL(rcu_lock_map);
-#endif
-
-
-/* Definition for rcupdate control block. */
-static struct rcu_ctrlblk rcu_ctrlblk = {
- .cur = -300,
- .completed = -300,
- .pending = -300,
- .lock = __SPIN_LOCK_UNLOCKED(&rcu_ctrlblk.lock),
- .cpumask = CPU_BITS_NONE,
-};
-
-static struct rcu_ctrlblk rcu_bh_ctrlblk = {
- .cur = -300,
- .completed = -300,
- .pending = -300,
- .lock = __SPIN_LOCK_UNLOCKED(&rcu_bh_ctrlblk.lock),
- .cpumask = CPU_BITS_NONE,
-};
-
-static DEFINE_PER_CPU(struct rcu_data, rcu_data);
-static DEFINE_PER_CPU(struct rcu_data, rcu_bh_data);
-
-/*
- * Increment the quiescent state counter.
- * The counter is a bit degenerated: We do not need to know
- * how many quiescent states passed, just if there was at least
- * one since the start of the grace period. Thus just a flag.
- */
-void rcu_qsctr_inc(int cpu)
-{
- struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
- rdp->passed_quiesc = 1;
-}
-
-void rcu_bh_qsctr_inc(int cpu)
-{
- struct rcu_data *rdp = &per_cpu(rcu_bh_data, cpu);
- rdp->passed_quiesc = 1;
-}
-
-static int blimit = 10;
-static int qhimark = 10000;
-static int qlowmark = 100;
-
-#ifdef CONFIG_SMP
-static void force_quiescent_state(struct rcu_data *rdp,
- struct rcu_ctrlblk *rcp)
-{
- int cpu;
- unsigned long flags;
-
- set_need_resched();
- spin_lock_irqsave(&rcp->lock, flags);
- if (unlikely(!rcp->signaled)) {
- rcp->signaled = 1;
- /*
- * Don't send IPI to itself. With irqs disabled,
- * rdp->cpu is the current cpu.
- *
- * cpu_online_mask is updated by the _cpu_down()
- * using __stop_machine(). Since we're in irqs disabled
- * section, __stop_machine() is not exectuting, hence
- * the cpu_online_mask is stable.
- *
- * However, a cpu might have been offlined _just_ before
- * we disabled irqs while entering here.
- * And rcu subsystem might not yet have handled the CPU_DEAD
- * notification, leading to the offlined cpu's bit
- * being set in the rcp->cpumask.
- *
- * Hence cpumask = (rcp->cpumask & cpu_online_mask) to prevent
- * sending smp_reschedule() to an offlined CPU.
- */
- for_each_cpu_and(cpu,
- to_cpumask(rcp->cpumask), cpu_online_mask) {
- if (cpu != rdp->cpu)
- smp_send_reschedule(cpu);
- }
- }
- spin_unlock_irqrestore(&rcp->lock, flags);
-}
-#else
-static inline void force_quiescent_state(struct rcu_data *rdp,
- struct rcu_ctrlblk *rcp)
-{
- set_need_resched();
-}
-#endif
-
-static void __call_rcu(struct rcu_head *head, struct rcu_ctrlblk *rcp,
- struct rcu_data *rdp)
-{
- long batch;
-
- head->next = NULL;
- smp_mb(); /* Read of rcu->cur must happen after any change by caller. */
-
- /*
- * Determine the batch number of this callback.
- *
- * Using ACCESS_ONCE to avoid the following error when gcc eliminates
- * local variable "batch" and emits codes like this:
- * 1) rdp->batch = rcp->cur + 1 # gets old value
- * ......
- * 2)rcu_batch_after(rcp->cur + 1, rdp->batch) # gets new value
- * then [*nxttail[0], *nxttail[1]) may contain callbacks
- * that batch# = rdp->batch, see the comment of struct rcu_data.
- */
- batch = ACCESS_ONCE(rcp->cur) + 1;
-
- if (rdp->nxtlist && rcu_batch_after(batch, rdp->batch)) {
- /* process callbacks */
- rdp->nxttail[0] = rdp->nxttail[1];
- rdp->nxttail[1] = rdp->nxttail[2];
- if (rcu_batch_after(batch - 1, rdp->batch))
- rdp->nxttail[0] = rdp->nxttail[2];
- }
-
- rdp->batch = batch;
- *rdp->nxttail[2] = head;
- rdp->nxttail[2] = &head->next;
-
- if (unlikely(++rdp->qlen > qhimark)) {
- rdp->blimit = INT_MAX;
- force_quiescent_state(rdp, &rcu_ctrlblk);
- }
-}
-
-#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
-
-static void record_gp_stall_check_time(struct rcu_ctrlblk *rcp)
-{
- rcp->gp_start = jiffies;
- rcp->jiffies_stall = jiffies + RCU_SECONDS_TILL_STALL_CHECK;
-}
-
-static void print_other_cpu_stall(struct rcu_ctrlblk *rcp)
-{
- int cpu;
- long delta;
- unsigned long flags;
-
- /* Only let one CPU complain about others per time interval. */
-
- spin_lock_irqsave(&rcp->lock, flags);
- delta = jiffies - rcp->jiffies_stall;
- if (delta < 2 || rcp->cur != rcp->completed) {
- spin_unlock_irqrestore(&rcp->lock, flags);
- return;
- }
- rcp->jiffies_stall = jiffies + RCU_SECONDS_TILL_STALL_RECHECK;
- spin_unlock_irqrestore(&rcp->lock, flags);
-
- /* OK, time to rat on our buddy... */
-
- printk(KERN_ERR "INFO: RCU detected CPU stalls:");
- for_each_possible_cpu(cpu) {
- if (cpumask_test_cpu(cpu, to_cpumask(rcp->cpumask)))
- printk(" %d", cpu);
- }
- printk(" (detected by %d, t=%ld jiffies)\n",
- smp_processor_id(), (long)(jiffies - rcp->gp_start));
-}
-
-static void print_cpu_stall(struct rcu_ctrlblk *rcp)
-{
- unsigned long flags;
-
- printk(KERN_ERR "INFO: RCU detected CPU %d stall (t=%lu/%lu jiffies)\n",
- smp_processor_id(), jiffies,
- jiffies - rcp->gp_start);
- dump_stack();
- spin_lock_irqsave(&rcp->lock, flags);
- if ((long)(jiffies - rcp->jiffies_stall) >= 0)
- rcp->jiffies_stall =
- jiffies + RCU_SECONDS_TILL_STALL_RECHECK;
- spin_unlock_irqrestore(&rcp->lock, flags);
- set_need_resched(); /* kick ourselves to get things going. */
-}
-
-static void check_cpu_stall(struct rcu_ctrlblk *rcp)
-{
- long delta;
-
- delta = jiffies - rcp->jiffies_stall;
- if (cpumask_test_cpu(smp_processor_id(), to_cpumask(rcp->cpumask)) &&
- delta >= 0) {
-
- /* We haven't checked in, so go dump stack. */
- print_cpu_stall(rcp);
-
- } else if (rcp->cur != rcp->completed && delta >= 2) {
-
- /* They had two seconds to dump stack, so complain. */
- print_other_cpu_stall(rcp);
- }
-}
-
-#else /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
-
-static void record_gp_stall_check_time(struct rcu_ctrlblk *rcp)
-{
-}
-
-static inline void check_cpu_stall(struct rcu_ctrlblk *rcp)
-{
-}
-
-#endif /* #else #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
-
-/**
- * call_rcu - Queue an RCU callback for invocation after a grace period.
- * @head: structure to be used for queueing the RCU updates.
- * @func: actual update function to be invoked after the grace period
- *
- * The update function will be invoked some time after a full grace
- * period elapses, in other words after all currently executing RCU
- * read-side critical sections have completed. RCU read-side critical
- * sections are delimited by rcu_read_lock() and rcu_read_unlock(),
- * and may be nested.
- */
-void call_rcu(struct rcu_head *head,
- void (*func)(struct rcu_head *rcu))
-{
- unsigned long flags;
-
- head->func = func;
- local_irq_save(flags);
- __call_rcu(head, &rcu_ctrlblk, &__get_cpu_var(rcu_data));
- local_irq_restore(flags);
-}
-EXPORT_SYMBOL_GPL(call_rcu);
-
-/**
- * call_rcu_bh - Queue an RCU for invocation after a quicker grace period.
- * @head: structure to be used for queueing the RCU updates.
- * @func: actual update function to be invoked after the grace period
- *
- * The update function will be invoked some time after a full grace
- * period elapses, in other words after all currently executing RCU
- * read-side critical sections have completed. call_rcu_bh() assumes
- * that the read-side critical sections end on completion of a softirq
- * handler. This means that read-side critical sections in process
- * context must not be interrupted by softirqs. This interface is to be
- * used when most of the read-side critical sections are in softirq context.
- * RCU read-side critical sections are delimited by rcu_read_lock() and
- * rcu_read_unlock(), * if in interrupt context or rcu_read_lock_bh()
- * and rcu_read_unlock_bh(), if in process context. These may be nested.
- */
-void call_rcu_bh(struct rcu_head *head,
- void (*func)(struct rcu_head *rcu))
-{
- unsigned long flags;
-
- head->func = func;
- local_irq_save(flags);
- __call_rcu(head, &rcu_bh_ctrlblk, &__get_cpu_var(rcu_bh_data));
- local_irq_restore(flags);
-}
-EXPORT_SYMBOL_GPL(call_rcu_bh);
-
-/*
- * Return the number of RCU batches processed thus far. Useful
- * for debug and statistics.
- */
-long rcu_batches_completed(void)
-{
- return rcu_ctrlblk.completed;
-}
-EXPORT_SYMBOL_GPL(rcu_batches_completed);
-
-/*
- * Return the number of RCU batches processed thus far. Useful
- * for debug and statistics.
- */
-long rcu_batches_completed_bh(void)
-{
- return rcu_bh_ctrlblk.completed;
-}
-EXPORT_SYMBOL_GPL(rcu_batches_completed_bh);
-
-/* Raises the softirq for processing rcu_callbacks. */
-static inline void raise_rcu_softirq(void)
-{
- raise_softirq(RCU_SOFTIRQ);
-}
-
-/*
- * Invoke the completed RCU callbacks. They are expected to be in
- * a per-cpu list.
- */
-static void rcu_do_batch(struct rcu_data *rdp)
-{
- unsigned long flags;
- struct rcu_head *next, *list;
- int count = 0;
-
- list = rdp->donelist;
- while (list) {
- next = list->next;
- prefetch(next);
- list->func(list);
- list = next;
- if (++count >= rdp->blimit)
- break;
- }
- rdp->donelist = list;
-
- local_irq_save(flags);
- rdp->qlen -= count;
- local_irq_restore(flags);
- if (rdp->blimit == INT_MAX && rdp->qlen <= qlowmark)
- rdp->blimit = blimit;
-
- if (!rdp->donelist)
- rdp->donetail = &rdp->donelist;
- else
- raise_rcu_softirq();
-}
-
-/*
- * Grace period handling:
- * The grace period handling consists out of two steps:
- * - A new grace period is started.
- * This is done by rcu_start_batch. The start is not broadcasted to
- * all cpus, they must pick this up by comparing rcp->cur with
- * rdp->quiescbatch. All cpus are recorded in the
- * rcu_ctrlblk.cpumask bitmap.
- * - All cpus must go through a quiescent state.
- * Since the start of the grace period is not broadcasted, at least two
- * calls to rcu_check_quiescent_state are required:
- * The first call just notices that a new grace period is running. The
- * following calls check if there was a quiescent state since the beginning
- * of the grace period. If so, it updates rcu_ctrlblk.cpumask. If
- * the bitmap is empty, then the grace period is completed.
- * rcu_check_quiescent_state calls rcu_start_batch(0) to start the next grace
- * period (if necessary).
- */
-
-/*
- * Register a new batch of callbacks, and start it up if there is currently no
- * active batch and the batch to be registered has not already occurred.
- * Caller must hold rcu_ctrlblk.lock.
- */
-static void rcu_start_batch(struct rcu_ctrlblk *rcp)
-{
- if (rcp->cur != rcp->pending &&
- rcp->completed == rcp->cur) {
- rcp->cur++;
- record_gp_stall_check_time(rcp);
-
- /*
- * Accessing nohz_cpu_mask before incrementing rcp->cur needs a
- * Barrier Otherwise it can cause tickless idle CPUs to be
- * included in rcp->cpumask, which will extend graceperiods
- * unnecessarily.
- */
- smp_mb();
- cpumask_andnot(to_cpumask(rcp->cpumask),
- cpu_online_mask, nohz_cpu_mask);
-
- rcp->signaled = 0;
- }
-}
-
-/*
- * cpu went through a quiescent state since the beginning of the grace period.
- * Clear it from the cpu mask and complete the grace period if it was the last
- * cpu. Start another grace period if someone has further entries pending
- */
-static void cpu_quiet(int cpu, struct rcu_ctrlblk *rcp)
-{
- cpumask_clear_cpu(cpu, to_cpumask(rcp->cpumask));
- if (cpumask_empty(to_cpumask(rcp->cpumask))) {
- /* batch completed ! */
- rcp->completed = rcp->cur;
- rcu_start_batch(rcp);
- }
-}
-
-/*
- * Check if the cpu has gone through a quiescent state (say context
- * switch). If so and if it already hasn't done so in this RCU
- * quiescent cycle, then indicate that it has done so.
- */
-static void rcu_check_quiescent_state(struct rcu_ctrlblk *rcp,
- struct rcu_data *rdp)
-{
- unsigned long flags;
-
- if (rdp->quiescbatch != rcp->cur) {
- /* start new grace period: */
- rdp->qs_pending = 1;
- rdp->passed_quiesc = 0;
- rdp->quiescbatch = rcp->cur;
- return;
- }
-
- /* Grace period already completed for this cpu?
- * qs_pending is checked instead of the actual bitmap to avoid
- * cacheline trashing.
- */
- if (!rdp->qs_pending)
- return;
-
- /*
- * Was there a quiescent state since the beginning of the grace
- * period? If no, then exit and wait for the next call.
- */
- if (!rdp->passed_quiesc)
- return;
- rdp->qs_pending = 0;
-
- spin_lock_irqsave(&rcp->lock, flags);
- /*
- * rdp->quiescbatch/rcp->cur and the cpu bitmap can come out of sync
- * during cpu startup. Ignore the quiescent state.
- */
- if (likely(rdp->quiescbatch == rcp->cur))
- cpu_quiet(rdp->cpu, rcp);
-
- spin_unlock_irqrestore(&rcp->lock, flags);
-}
-
-
-#ifdef CONFIG_HOTPLUG_CPU
-
-/* warning! helper for rcu_offline_cpu. do not use elsewhere without reviewing
- * locking requirements, the list it's pulling from has to belong to a cpu
- * which is dead and hence not processing interrupts.
- */
-static void rcu_move_batch(struct rcu_data *this_rdp, struct rcu_head *list,
- struct rcu_head **tail, long batch)
-{
- unsigned long flags;
-
- if (list) {
- local_irq_save(flags);
- this_rdp->batch = batch;
- *this_rdp->nxttail[2] = list;
- this_rdp->nxttail[2] = tail;
- local_irq_restore(flags);
- }
-}
-
-static void __rcu_offline_cpu(struct rcu_data *this_rdp,
- struct rcu_ctrlblk *rcp, struct rcu_data *rdp)
-{
- unsigned long flags;
-
- /*
- * if the cpu going offline owns the grace period
- * we can block indefinitely waiting for it, so flush
- * it here
- */
- spin_lock_irqsave(&rcp->lock, flags);
- if (rcp->cur != rcp->completed)
- cpu_quiet(rdp->cpu, rcp);
- rcu_move_batch(this_rdp, rdp->donelist, rdp->donetail, rcp->cur + 1);
- rcu_move_batch(this_rdp, rdp->nxtlist, rdp->nxttail[2], rcp->cur + 1);
- spin_unlock(&rcp->lock);
-
- this_rdp->qlen += rdp->qlen;
- local_irq_restore(flags);
-}
-
-static void rcu_offline_cpu(int cpu)
-{
- struct rcu_data *this_rdp = &get_cpu_var(rcu_data);
- struct rcu_data *this_bh_rdp = &get_cpu_var(rcu_bh_data);
-
- __rcu_offline_cpu(this_rdp, &rcu_ctrlblk,
- &per_cpu(rcu_data, cpu));
- __rcu_offline_cpu(this_bh_rdp, &rcu_bh_ctrlblk,
- &per_cpu(rcu_bh_data, cpu));
- put_cpu_var(rcu_data);
- put_cpu_var(rcu_bh_data);
-}
-
-#else
-
-static void rcu_offline_cpu(int cpu)
-{
-}
-
-#endif
-
-/*
- * This does the RCU processing work from softirq context.
- */
-static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp,
- struct rcu_data *rdp)
-{
- unsigned long flags;
- long completed_snap;
-
- if (rdp->nxtlist) {
- local_irq_save(flags);
- completed_snap = ACCESS_ONCE(rcp->completed);
-
- /*
- * move the other grace-period-completed entries to
- * [rdp->nxtlist, *rdp->nxttail[0]) temporarily
- */
- if (!rcu_batch_before(completed_snap, rdp->batch))
- rdp->nxttail[0] = rdp->nxttail[1] = rdp->nxttail[2];
- else if (!rcu_batch_before(completed_snap, rdp->batch - 1))
- rdp->nxttail[0] = rdp->nxttail[1];
-
- /*
- * the grace period for entries in
- * [rdp->nxtlist, *rdp->nxttail[0]) has completed and
- * move these entries to donelist
- */
- if (rdp->nxttail[0] != &rdp->nxtlist) {
- *rdp->donetail = rdp->nxtlist;
- rdp->donetail = rdp->nxttail[0];
- rdp->nxtlist = *rdp->nxttail[0];
- *rdp->donetail = NULL;
-
- if (rdp->nxttail[1] == rdp->nxttail[0])
- rdp->nxttail[1] = &rdp->nxtlist;
- if (rdp->nxttail[2] == rdp->nxttail[0])
- rdp->nxttail[2] = &rdp->nxtlist;
- rdp->nxttail[0] = &rdp->nxtlist;
- }
-
- local_irq_restore(flags);
-
- if (rcu_batch_after(rdp->batch, rcp->pending)) {
- unsigned long flags2;
-
- /* and start it/schedule start if it's a new batch */
- spin_lock_irqsave(&rcp->lock, flags2);
- if (rcu_batch_after(rdp->batch, rcp->pending)) {
- rcp->pending = rdp->batch;
- rcu_start_batch(rcp);
- }
- spin_unlock_irqrestore(&rcp->lock, flags2);
- }
- }
-
- rcu_check_quiescent_state(rcp, rdp);
- if (rdp->donelist)
- rcu_do_batch(rdp);
-}
-
-static void rcu_process_callbacks(struct softirq_action *unused)
-{
- /*
- * Memory references from any prior RCU read-side critical sections
- * executed by the interrupted code must be see before any RCU
- * grace-period manupulations below.
- */
-
- smp_mb(); /* See above block comment. */
-
- __rcu_process_callbacks(&rcu_ctrlblk, &__get_cpu_var(rcu_data));
- __rcu_process_callbacks(&rcu_bh_ctrlblk, &__get_cpu_var(rcu_bh_data));
-
- /*
- * Memory references from any later RCU read-side critical sections
- * executed by the interrupted code must be see after any RCU
- * grace-period manupulations above.
- */
-
- smp_mb(); /* See above block comment. */
-}
-
-static int __rcu_pending(struct rcu_ctrlblk *rcp, struct rcu_data *rdp)
-{
- /* Check for CPU stalls, if enabled. */
- check_cpu_stall(rcp);
-
- if (rdp->nxtlist) {
- long completed_snap = ACCESS_ONCE(rcp->completed);
-
- /*
- * This cpu has pending rcu entries and the grace period
- * for them has completed.
- */
- if (!rcu_batch_before(completed_snap, rdp->batch))
- return 1;
- if (!rcu_batch_before(completed_snap, rdp->batch - 1) &&
- rdp->nxttail[0] != rdp->nxttail[1])
- return 1;
- if (rdp->nxttail[0] != &rdp->nxtlist)
- return 1;
-
- /*
- * This cpu has pending rcu entries and the new batch
- * for then hasn't been started nor scheduled start
- */
- if (rcu_batch_after(rdp->batch, rcp->pending))
- return 1;
- }
-
- /* This cpu has finished callbacks to invoke */
- if (rdp->donelist)
- return 1;
-
- /* The rcu core waits for a quiescent state from the cpu */
- if (rdp->quiescbatch != rcp->cur || rdp->qs_pending)
- return 1;
-
- /* nothing to do */
- return 0;
-}
-
-/*
- * Check to see if there is any immediate RCU-related work to be done
- * by the current CPU, returning 1 if so. This function is part of the
- * RCU implementation; it is -not- an exported member of the RCU API.
- */
-int rcu_pending(int cpu)
-{
- return __rcu_pending(&rcu_ctrlblk, &per_cpu(rcu_data, cpu)) ||
- __rcu_pending(&rcu_bh_ctrlblk, &per_cpu(rcu_bh_data, cpu));
-}
-
-/*
- * Check to see if any future RCU-related work will need to be done
- * by the current CPU, even if none need be done immediately, returning
- * 1 if so. This function is part of the RCU implementation; it is -not-
- * an exported member of the RCU API.
- */
-int rcu_needs_cpu(int cpu)
-{
- struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
- struct rcu_data *rdp_bh = &per_cpu(rcu_bh_data, cpu);
-
- return !!rdp->nxtlist || !!rdp_bh->nxtlist || rcu_pending(cpu);
-}
-
-/*
- * Top-level function driving RCU grace-period detection, normally
- * invoked from the scheduler-clock interrupt. This function simply
- * increments counters that are read only from softirq by this same
- * CPU, so there are no memory barriers required.
- */
-void rcu_check_callbacks(int cpu, int user)
-{
- if (user ||
- (idle_cpu(cpu) && rcu_scheduler_active &&
- !in_softirq() && hardirq_count() <= (1 << HARDIRQ_SHIFT))) {
-
- /*
- * Get here if this CPU took its interrupt from user
- * mode or from the idle loop, and if this is not a
- * nested interrupt. In this case, the CPU is in
- * a quiescent state, so count it.
- *
- * Also do a memory barrier. This is needed to handle
- * the case where writes from a preempt-disable section
- * of code get reordered into schedule() by this CPU's
- * write buffer. The memory barrier makes sure that
- * the rcu_qsctr_inc() and rcu_bh_qsctr_inc() are see
- * by other CPUs to happen after any such write.
- */
-
- smp_mb(); /* See above block comment. */
- rcu_qsctr_inc(cpu);
- rcu_bh_qsctr_inc(cpu);
-
- } else if (!in_softirq()) {
-
- /*
- * Get here if this CPU did not take its interrupt from
- * softirq, in other words, if it is not interrupting
- * a rcu_bh read-side critical section. This is an _bh
- * critical section, so count it. The memory barrier
- * is needed for the same reason as is the above one.
- */
-
- smp_mb(); /* See above block comment. */
- rcu_bh_qsctr_inc(cpu);
- }
- raise_rcu_softirq();
-}
-
-static void __cpuinit rcu_init_percpu_data(int cpu, struct rcu_ctrlblk *rcp,
- struct rcu_data *rdp)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&rcp->lock, flags);
- memset(rdp, 0, sizeof(*rdp));
- rdp->nxttail[0] = rdp->nxttail[1] = rdp->nxttail[2] = &rdp->nxtlist;
- rdp->donetail = &rdp->donelist;
- rdp->quiescbatch = rcp->completed;
- rdp->qs_pending = 0;
- rdp->cpu = cpu;
- rdp->blimit = blimit;
- spin_unlock_irqrestore(&rcp->lock, flags);
-}
-
-static void __cpuinit rcu_online_cpu(int cpu)
-{
- struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
- struct rcu_data *bh_rdp = &per_cpu(rcu_bh_data, cpu);
-
- rcu_init_percpu_data(cpu, &rcu_ctrlblk, rdp);
- rcu_init_percpu_data(cpu, &rcu_bh_ctrlblk, bh_rdp);
- open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
-}
-
-static int __cpuinit rcu_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
-{
- long cpu = (long)hcpu;
-
- switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- rcu_online_cpu(cpu);
- break;
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- rcu_offline_cpu(cpu);
- break;
- default:
- break;
- }
- return NOTIFY_OK;
-}
-
-static struct notifier_block __cpuinitdata rcu_nb = {
- .notifier_call = rcu_cpu_notify,
-};
-
-/*
- * Initializes rcu mechanism. Assumed to be called early.
- * That is before local timer(SMP) or jiffie timer (uniproc) is setup.
- * Note that rcu_qsctr and friends are implicitly
- * initialized due to the choice of ``0'' for RCU_CTR_INVALID.
- */
-void __init __rcu_init(void)
-{
-#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
- printk(KERN_INFO "RCU-based detection of stalled CPUs is enabled.\n");
-#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
- rcu_cpu_notify(&rcu_nb, CPU_UP_PREPARE,
- (void *)(long)smp_processor_id());
- /* Register notifier for non-boot CPUs */
- register_cpu_notifier(&rcu_nb);
-}
-
-module_param(blimit, int, 0);
-module_param(qhimark, int, 0);
-module_param(qlowmark, int, 0);
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index a967c9feb90a..bd5d5c8e5140 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -98,6 +98,30 @@ void synchronize_rcu(void)
}
EXPORT_SYMBOL_GPL(synchronize_rcu);
+/**
+ * synchronize_rcu_bh - wait until an rcu_bh grace period has elapsed.
+ *
+ * Control will return to the caller some time after a full rcu_bh grace
+ * period has elapsed, in other words after all currently executing rcu_bh
+ * read-side critical sections have completed. RCU read-side critical
+ * sections are delimited by rcu_read_lock_bh() and rcu_read_unlock_bh(),
+ * and may be nested.
+ */
+void synchronize_rcu_bh(void)
+{
+ struct rcu_synchronize rcu;
+
+ if (rcu_blocking_is_gp())
+ return;
+
+ init_completion(&rcu.completion);
+ /* Will wake me after RCU finished. */
+ call_rcu_bh(&rcu.head, wakeme_after_rcu);
+ /* Wait for it. */
+ wait_for_completion(&rcu.completion);
+}
+EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
+
static void rcu_barrier_callback(struct rcu_head *notused)
{
if (atomic_dec_and_test(&rcu_barrier_cpu_count))
@@ -129,6 +153,7 @@ static void rcu_barrier_func(void *type)
static inline void wait_migrated_callbacks(void)
{
wait_event(rcu_migrate_wq, !atomic_read(&rcu_migrate_type_count));
+ smp_mb(); /* In case we didn't sleep. */
}
/*
@@ -192,9 +217,13 @@ static void rcu_migrate_callback(struct rcu_head *notused)
wake_up(&rcu_migrate_wq);
}
+extern int rcu_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu);
+
static int __cpuinit rcu_barrier_cpu_hotplug(struct notifier_block *self,
unsigned long action, void *hcpu)
{
+ rcu_cpu_notify(self, action, hcpu);
if (action == CPU_DYING) {
/*
* preempt_disable() in on_each_cpu() prevents stop_machine(),
@@ -209,7 +238,8 @@ static int __cpuinit rcu_barrier_cpu_hotplug(struct notifier_block *self,
call_rcu_bh(rcu_migrate_head, rcu_migrate_callback);
call_rcu_sched(rcu_migrate_head + 1, rcu_migrate_callback);
call_rcu(rcu_migrate_head + 2, rcu_migrate_callback);
- } else if (action == CPU_POST_DEAD) {
+ } else if (action == CPU_DOWN_PREPARE) {
+ /* Don't need to wait until next removal operation. */
/* rcu_migrate_head is protected by cpu_add_remove_lock */
wait_migrated_callbacks();
}
@@ -219,8 +249,18 @@ static int __cpuinit rcu_barrier_cpu_hotplug(struct notifier_block *self,
void __init rcu_init(void)
{
+ int i;
+
__rcu_init();
- hotcpu_notifier(rcu_barrier_cpu_hotplug, 0);
+ cpu_notifier(rcu_barrier_cpu_hotplug, 0);
+
+ /*
+ * We don't need protection against CPU-hotplug here because
+ * this is called early in boot, before either interrupts
+ * or the scheduler are operational.
+ */
+ for_each_online_cpu(i)
+ rcu_barrier_cpu_hotplug(NULL, CPU_UP_PREPARE, (void *)(long)i);
}
void rcu_scheduler_starting(void)
diff --git a/kernel/rcupreempt.c b/kernel/rcupreempt.c
deleted file mode 100644
index beb0e659adcc..000000000000
--- a/kernel/rcupreempt.c
+++ /dev/null
@@ -1,1539 +0,0 @@
-/*
- * Read-Copy Update mechanism for mutual exclusion, realtime implementation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *
- * Copyright IBM Corporation, 2006
- *
- * Authors: Paul E. McKenney <paulmck@us.ibm.com>
- * With thanks to Esben Nielsen, Bill Huey, and Ingo Molnar
- * for pushing me away from locks and towards counters, and
- * to Suparna Bhattacharya for pushing me completely away
- * from atomic instructions on the read side.
- *
- * - Added handling of Dynamic Ticks
- * Copyright 2007 - Paul E. Mckenney <paulmck@us.ibm.com>
- * - Steven Rostedt <srostedt@redhat.com>
- *
- * Papers: http://www.rdrop.com/users/paulmck/RCU
- *
- * Design Document: http://lwn.net/Articles/253651/
- *
- * For detailed explanation of Read-Copy Update mechanism see -
- * Documentation/RCU/ *.txt
- *
- */
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/spinlock.h>
-#include <linux/smp.h>
-#include <linux/rcupdate.h>
-#include <linux/interrupt.h>
-#include <linux/sched.h>
-#include <asm/atomic.h>
-#include <linux/bitops.h>
-#include <linux/module.h>
-#include <linux/kthread.h>
-#include <linux/completion.h>
-#include <linux/moduleparam.h>
-#include <linux/percpu.h>
-#include <linux/notifier.h>
-#include <linux/cpu.h>
-#include <linux/random.h>
-#include <linux/delay.h>
-#include <linux/cpumask.h>
-#include <linux/rcupreempt_trace.h>
-#include <asm/byteorder.h>
-
-/*
- * PREEMPT_RCU data structures.
- */
-
-/*
- * GP_STAGES specifies the number of times the state machine has
- * to go through the all the rcu_try_flip_states (see below)
- * in a single Grace Period.
- *
- * GP in GP_STAGES stands for Grace Period ;)
- */
-#define GP_STAGES 2
-struct rcu_data {
- spinlock_t lock; /* Protect rcu_data fields. */
- long completed; /* Number of last completed batch. */
- int waitlistcount;
- struct rcu_head *nextlist;
- struct rcu_head **nexttail;
- struct rcu_head *waitlist[GP_STAGES];
- struct rcu_head **waittail[GP_STAGES];
- struct rcu_head *donelist; /* from waitlist & waitschedlist */
- struct rcu_head **donetail;
- long rcu_flipctr[2];
- struct rcu_head *nextschedlist;
- struct rcu_head **nextschedtail;
- struct rcu_head *waitschedlist;
- struct rcu_head **waitschedtail;
- int rcu_sched_sleeping;
-#ifdef CONFIG_RCU_TRACE
- struct rcupreempt_trace trace;
-#endif /* #ifdef CONFIG_RCU_TRACE */
-};
-
-/*
- * States for rcu_try_flip() and friends.
- */
-
-enum rcu_try_flip_states {
-
- /*
- * Stay here if nothing is happening. Flip the counter if somthing
- * starts happening. Denoted by "I"
- */
- rcu_try_flip_idle_state,
-
- /*
- * Wait here for all CPUs to notice that the counter has flipped. This
- * prevents the old set of counters from ever being incremented once
- * we leave this state, which in turn is necessary because we cannot
- * test any individual counter for zero -- we can only check the sum.
- * Denoted by "A".
- */
- rcu_try_flip_waitack_state,
-
- /*
- * Wait here for the sum of the old per-CPU counters to reach zero.
- * Denoted by "Z".
- */
- rcu_try_flip_waitzero_state,
-
- /*
- * Wait here for each of the other CPUs to execute a memory barrier.
- * This is necessary to ensure that these other CPUs really have
- * completed executing their RCU read-side critical sections, despite
- * their CPUs wildly reordering memory. Denoted by "M".
- */
- rcu_try_flip_waitmb_state,
-};
-
-/*
- * States for rcu_ctrlblk.rcu_sched_sleep.
- */
-
-enum rcu_sched_sleep_states {
- rcu_sched_not_sleeping, /* Not sleeping, callbacks need GP. */
- rcu_sched_sleep_prep, /* Thinking of sleeping, rechecking. */
- rcu_sched_sleeping, /* Sleeping, awaken if GP needed. */
-};
-
-struct rcu_ctrlblk {
- spinlock_t fliplock; /* Protect state-machine transitions. */
- long completed; /* Number of last completed batch. */
- enum rcu_try_flip_states rcu_try_flip_state; /* The current state of
- the rcu state machine */
- spinlock_t schedlock; /* Protect rcu_sched sleep state. */
- enum rcu_sched_sleep_states sched_sleep; /* rcu_sched state. */
- wait_queue_head_t sched_wq; /* Place for rcu_sched to sleep. */
-};
-
-struct rcu_dyntick_sched {
- int dynticks;
- int dynticks_snap;
- int sched_qs;
- int sched_qs_snap;
- int sched_dynticks_snap;
-};
-
-static DEFINE_PER_CPU_SHARED_ALIGNED(struct rcu_dyntick_sched, rcu_dyntick_sched) = {
- .dynticks = 1,
-};
-
-void rcu_qsctr_inc(int cpu)
-{
- struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu);
-
- rdssp->sched_qs++;
-}
-
-#ifdef CONFIG_NO_HZ
-
-void rcu_enter_nohz(void)
-{
- static DEFINE_RATELIMIT_STATE(rs, 10 * HZ, 1);
-
- smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
- __get_cpu_var(rcu_dyntick_sched).dynticks++;
- WARN_ON_RATELIMIT(__get_cpu_var(rcu_dyntick_sched).dynticks & 0x1, &rs);
-}
-
-void rcu_exit_nohz(void)
-{
- static DEFINE_RATELIMIT_STATE(rs, 10 * HZ, 1);
-
- __get_cpu_var(rcu_dyntick_sched).dynticks++;
- smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
- WARN_ON_RATELIMIT(!(__get_cpu_var(rcu_dyntick_sched).dynticks & 0x1),
- &rs);
-}
-
-#endif /* CONFIG_NO_HZ */
-
-
-static DEFINE_PER_CPU(struct rcu_data, rcu_data);
-
-static struct rcu_ctrlblk rcu_ctrlblk = {
- .fliplock = __SPIN_LOCK_UNLOCKED(rcu_ctrlblk.fliplock),
- .completed = 0,
- .rcu_try_flip_state = rcu_try_flip_idle_state,
- .schedlock = __SPIN_LOCK_UNLOCKED(rcu_ctrlblk.schedlock),
- .sched_sleep = rcu_sched_not_sleeping,
- .sched_wq = __WAIT_QUEUE_HEAD_INITIALIZER(rcu_ctrlblk.sched_wq),
-};
-
-static struct task_struct *rcu_sched_grace_period_task;
-
-#ifdef CONFIG_RCU_TRACE
-static char *rcu_try_flip_state_names[] =
- { "idle", "waitack", "waitzero", "waitmb" };
-#endif /* #ifdef CONFIG_RCU_TRACE */
-
-static DECLARE_BITMAP(rcu_cpu_online_map, NR_CPUS) __read_mostly
- = CPU_BITS_NONE;
-
-/*
- * Enum and per-CPU flag to determine when each CPU has seen
- * the most recent counter flip.
- */
-
-enum rcu_flip_flag_values {
- rcu_flip_seen, /* Steady/initial state, last flip seen. */
- /* Only GP detector can update. */
- rcu_flipped /* Flip just completed, need confirmation. */
- /* Only corresponding CPU can update. */
-};
-static DEFINE_PER_CPU_SHARED_ALIGNED(enum rcu_flip_flag_values, rcu_flip_flag)
- = rcu_flip_seen;
-
-/*
- * Enum and per-CPU flag to determine when each CPU has executed the
- * needed memory barrier to fence in memory references from its last RCU
- * read-side critical section in the just-completed grace period.
- */
-
-enum rcu_mb_flag_values {
- rcu_mb_done, /* Steady/initial state, no mb()s required. */
- /* Only GP detector can update. */
- rcu_mb_needed /* Flip just completed, need an mb(). */
- /* Only corresponding CPU can update. */
-};
-static DEFINE_PER_CPU_SHARED_ALIGNED(enum rcu_mb_flag_values, rcu_mb_flag)
- = rcu_mb_done;
-
-/*
- * RCU_DATA_ME: find the current CPU's rcu_data structure.
- * RCU_DATA_CPU: find the specified CPU's rcu_data structure.
- */
-#define RCU_DATA_ME() (&__get_cpu_var(rcu_data))
-#define RCU_DATA_CPU(cpu) (&per_cpu(rcu_data, cpu))
-
-/*
- * Helper macro for tracing when the appropriate rcu_data is not
- * cached in a local variable, but where the CPU number is so cached.
- */
-#define RCU_TRACE_CPU(f, cpu) RCU_TRACE(f, &(RCU_DATA_CPU(cpu)->trace));
-
-/*
- * Helper macro for tracing when the appropriate rcu_data is not
- * cached in a local variable.
- */
-#define RCU_TRACE_ME(f) RCU_TRACE(f, &(RCU_DATA_ME()->trace));
-
-/*
- * Helper macro for tracing when the appropriate rcu_data is pointed
- * to by a local variable.
- */
-#define RCU_TRACE_RDP(f, rdp) RCU_TRACE(f, &((rdp)->trace));
-
-#define RCU_SCHED_BATCH_TIME (HZ / 50)
-
-/*
- * Return the number of RCU batches processed thus far. Useful
- * for debug and statistics.
- */
-long rcu_batches_completed(void)
-{
- return rcu_ctrlblk.completed;
-}
-EXPORT_SYMBOL_GPL(rcu_batches_completed);
-
-void __rcu_read_lock(void)
-{
- int idx;
- struct task_struct *t = current;
- int nesting;
-
- nesting = ACCESS_ONCE(t->rcu_read_lock_nesting);
- if (nesting != 0) {
-
- /* An earlier rcu_read_lock() covers us, just count it. */
-
- t->rcu_read_lock_nesting = nesting + 1;
-
- } else {
- unsigned long flags;
-
- /*
- * We disable interrupts for the following reasons:
- * - If we get scheduling clock interrupt here, and we
- * end up acking the counter flip, it's like a promise
- * that we will never increment the old counter again.
- * Thus we will break that promise if that
- * scheduling clock interrupt happens between the time
- * we pick the .completed field and the time that we
- * increment our counter.
- *
- * - We don't want to be preempted out here.
- *
- * NMIs can still occur, of course, and might themselves
- * contain rcu_read_lock().
- */
-
- local_irq_save(flags);
-
- /*
- * Outermost nesting of rcu_read_lock(), so increment
- * the current counter for the current CPU. Use volatile
- * casts to prevent the compiler from reordering.
- */
-
- idx = ACCESS_ONCE(rcu_ctrlblk.completed) & 0x1;
- ACCESS_ONCE(RCU_DATA_ME()->rcu_flipctr[idx])++;
-
- /*
- * Now that the per-CPU counter has been incremented, we
- * are protected from races with rcu_read_lock() invoked
- * from NMI handlers on this CPU. We can therefore safely
- * increment the nesting counter, relieving further NMIs
- * of the need to increment the per-CPU counter.
- */
-
- ACCESS_ONCE(t->rcu_read_lock_nesting) = nesting + 1;
-
- /*
- * Now that we have preventing any NMIs from storing
- * to the ->rcu_flipctr_idx, we can safely use it to
- * remember which counter to decrement in the matching
- * rcu_read_unlock().
- */
-
- ACCESS_ONCE(t->rcu_flipctr_idx) = idx;
- local_irq_restore(flags);
- }
-}
-EXPORT_SYMBOL_GPL(__rcu_read_lock);
-
-void __rcu_read_unlock(void)
-{
- int idx;
- struct task_struct *t = current;
- int nesting;
-
- nesting = ACCESS_ONCE(t->rcu_read_lock_nesting);
- if (nesting > 1) {
-
- /*
- * We are still protected by the enclosing rcu_read_lock(),
- * so simply decrement the counter.
- */
-
- t->rcu_read_lock_nesting = nesting - 1;
-
- } else {
- unsigned long flags;
-
- /*
- * Disable local interrupts to prevent the grace-period
- * detection state machine from seeing us half-done.
- * NMIs can still occur, of course, and might themselves
- * contain rcu_read_lock() and rcu_read_unlock().
- */
-
- local_irq_save(flags);
-
- /*
- * Outermost nesting of rcu_read_unlock(), so we must
- * decrement the current counter for the current CPU.
- * This must be done carefully, because NMIs can
- * occur at any point in this code, and any rcu_read_lock()
- * and rcu_read_unlock() pairs in the NMI handlers
- * must interact non-destructively with this code.
- * Lots of volatile casts, and -very- careful ordering.
- *
- * Changes to this code, including this one, must be
- * inspected, validated, and tested extremely carefully!!!
- */
-
- /*
- * First, pick up the index.
- */
-
- idx = ACCESS_ONCE(t->rcu_flipctr_idx);
-
- /*
- * Now that we have fetched the counter index, it is
- * safe to decrement the per-task RCU nesting counter.
- * After this, any interrupts or NMIs will increment and
- * decrement the per-CPU counters.
- */
- ACCESS_ONCE(t->rcu_read_lock_nesting) = nesting - 1;
-
- /*
- * It is now safe to decrement this task's nesting count.
- * NMIs that occur after this statement will route their
- * rcu_read_lock() calls through this "else" clause, and
- * will thus start incrementing the per-CPU counter on
- * their own. They will also clobber ->rcu_flipctr_idx,
- * but that is OK, since we have already fetched it.
- */
-
- ACCESS_ONCE(RCU_DATA_ME()->rcu_flipctr[idx])--;
- local_irq_restore(flags);
- }
-}
-EXPORT_SYMBOL_GPL(__rcu_read_unlock);
-
-/*
- * If a global counter flip has occurred since the last time that we
- * advanced callbacks, advance them. Hardware interrupts must be
- * disabled when calling this function.
- */
-static void __rcu_advance_callbacks(struct rcu_data *rdp)
-{
- int cpu;
- int i;
- int wlc = 0;
-
- if (rdp->completed != rcu_ctrlblk.completed) {
- if (rdp->waitlist[GP_STAGES - 1] != NULL) {
- *rdp->donetail = rdp->waitlist[GP_STAGES - 1];
- rdp->donetail = rdp->waittail[GP_STAGES - 1];
- RCU_TRACE_RDP(rcupreempt_trace_move2done, rdp);
- }
- for (i = GP_STAGES - 2; i >= 0; i--) {
- if (rdp->waitlist[i] != NULL) {
- rdp->waitlist[i + 1] = rdp->waitlist[i];
- rdp->waittail[i + 1] = rdp->waittail[i];
- wlc++;
- } else {
- rdp->waitlist[i + 1] = NULL;
- rdp->waittail[i + 1] =
- &rdp->waitlist[i + 1];
- }
- }
- if (rdp->nextlist != NULL) {
- rdp->waitlist[0] = rdp->nextlist;
- rdp->waittail[0] = rdp->nexttail;
- wlc++;
- rdp->nextlist = NULL;
- rdp->nexttail = &rdp->nextlist;
- RCU_TRACE_RDP(rcupreempt_trace_move2wait, rdp);
- } else {
- rdp->waitlist[0] = NULL;
- rdp->waittail[0] = &rdp->waitlist[0];
- }
- rdp->waitlistcount = wlc;
- rdp->completed = rcu_ctrlblk.completed;
- }
-
- /*
- * Check to see if this CPU needs to report that it has seen
- * the most recent counter flip, thereby declaring that all
- * subsequent rcu_read_lock() invocations will respect this flip.
- */
-
- cpu = raw_smp_processor_id();
- if (per_cpu(rcu_flip_flag, cpu) == rcu_flipped) {
- smp_mb(); /* Subsequent counter accesses must see new value */
- per_cpu(rcu_flip_flag, cpu) = rcu_flip_seen;
- smp_mb(); /* Subsequent RCU read-side critical sections */
- /* seen -after- acknowledgement. */
- }
-}
-
-#ifdef CONFIG_NO_HZ
-static DEFINE_PER_CPU(int, rcu_update_flag);
-
-/**
- * rcu_irq_enter - Called from Hard irq handlers and NMI/SMI.
- *
- * If the CPU was idle with dynamic ticks active, this updates the
- * rcu_dyntick_sched.dynticks to let the RCU handling know that the
- * CPU is active.
- */
-void rcu_irq_enter(void)
-{
- int cpu = smp_processor_id();
- struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu);
-
- if (per_cpu(rcu_update_flag, cpu))
- per_cpu(rcu_update_flag, cpu)++;
-
- /*
- * Only update if we are coming from a stopped ticks mode
- * (rcu_dyntick_sched.dynticks is even).
- */
- if (!in_interrupt() &&
- (rdssp->dynticks & 0x1) == 0) {
- /*
- * The following might seem like we could have a race
- * with NMI/SMIs. But this really isn't a problem.
- * Here we do a read/modify/write, and the race happens
- * when an NMI/SMI comes in after the read and before
- * the write. But NMI/SMIs will increment this counter
- * twice before returning, so the zero bit will not
- * be corrupted by the NMI/SMI which is the most important
- * part.
- *
- * The only thing is that we would bring back the counter
- * to a postion that it was in during the NMI/SMI.
- * But the zero bit would be set, so the rest of the
- * counter would again be ignored.
- *
- * On return from the IRQ, the counter may have the zero
- * bit be 0 and the counter the same as the return from
- * the NMI/SMI. If the state machine was so unlucky to
- * see that, it still doesn't matter, since all
- * RCU read-side critical sections on this CPU would
- * have already completed.
- */
- rdssp->dynticks++;
- /*
- * The following memory barrier ensures that any
- * rcu_read_lock() primitives in the irq handler
- * are seen by other CPUs to follow the above
- * increment to rcu_dyntick_sched.dynticks. This is
- * required in order for other CPUs to correctly
- * determine when it is safe to advance the RCU
- * grace-period state machine.
- */
- smp_mb(); /* see above block comment. */
- /*
- * Since we can't determine the dynamic tick mode from
- * the rcu_dyntick_sched.dynticks after this routine,
- * we use a second flag to acknowledge that we came
- * from an idle state with ticks stopped.
- */
- per_cpu(rcu_update_flag, cpu)++;
- /*
- * If we take an NMI/SMI now, they will also increment
- * the rcu_update_flag, and will not update the
- * rcu_dyntick_sched.dynticks on exit. That is for
- * this IRQ to do.
- */
- }
-}
-
-/**
- * rcu_irq_exit - Called from exiting Hard irq context.
- *
- * If the CPU was idle with dynamic ticks active, update the
- * rcu_dyntick_sched.dynticks to put let the RCU handling be
- * aware that the CPU is going back to idle with no ticks.
- */
-void rcu_irq_exit(void)
-{
- int cpu = smp_processor_id();
- struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu);
-
- /*
- * rcu_update_flag is set if we interrupted the CPU
- * when it was idle with ticks stopped.
- * Once this occurs, we keep track of interrupt nesting
- * because a NMI/SMI could also come in, and we still
- * only want the IRQ that started the increment of the
- * rcu_dyntick_sched.dynticks to be the one that modifies
- * it on exit.
- */
- if (per_cpu(rcu_update_flag, cpu)) {
- if (--per_cpu(rcu_update_flag, cpu))
- return;
-
- /* This must match the interrupt nesting */
- WARN_ON(in_interrupt());
-
- /*
- * If an NMI/SMI happens now we are still
- * protected by the rcu_dyntick_sched.dynticks being odd.
- */
-
- /*
- * The following memory barrier ensures that any
- * rcu_read_unlock() primitives in the irq handler
- * are seen by other CPUs to preceed the following
- * increment to rcu_dyntick_sched.dynticks. This
- * is required in order for other CPUs to determine
- * when it is safe to advance the RCU grace-period
- * state machine.
- */
- smp_mb(); /* see above block comment. */
- rdssp->dynticks++;
- WARN_ON(rdssp->dynticks & 0x1);
- }
-}
-
-void rcu_nmi_enter(void)
-{
- rcu_irq_enter();
-}
-
-void rcu_nmi_exit(void)
-{
- rcu_irq_exit();
-}
-
-static void dyntick_save_progress_counter(int cpu)
-{
- struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu);
-
- rdssp->dynticks_snap = rdssp->dynticks;
-}
-
-static inline int
-rcu_try_flip_waitack_needed(int cpu)
-{
- long curr;
- long snap;
- struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu);
-
- curr = rdssp->dynticks;
- snap = rdssp->dynticks_snap;
- smp_mb(); /* force ordering with cpu entering/leaving dynticks. */
-
- /*
- * If the CPU remained in dynticks mode for the entire time
- * and didn't take any interrupts, NMIs, SMIs, or whatever,
- * then it cannot be in the middle of an rcu_read_lock(), so
- * the next rcu_read_lock() it executes must use the new value
- * of the counter. So we can safely pretend that this CPU
- * already acknowledged the counter.
- */
-
- if ((curr == snap) && ((curr & 0x1) == 0))
- return 0;
-
- /*
- * If the CPU passed through or entered a dynticks idle phase with
- * no active irq handlers, then, as above, we can safely pretend
- * that this CPU already acknowledged the counter.
- */
-
- if ((curr - snap) > 2 || (curr & 0x1) == 0)
- return 0;
-
- /* We need this CPU to explicitly acknowledge the counter flip. */
-
- return 1;
-}
-
-static inline int
-rcu_try_flip_waitmb_needed(int cpu)
-{
- long curr;
- long snap;
- struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu);
-
- curr = rdssp->dynticks;
- snap = rdssp->dynticks_snap;
- smp_mb(); /* force ordering with cpu entering/leaving dynticks. */
-
- /*
- * If the CPU remained in dynticks mode for the entire time
- * and didn't take any interrupts, NMIs, SMIs, or whatever,
- * then it cannot have executed an RCU read-side critical section
- * during that time, so there is no need for it to execute a
- * memory barrier.
- */
-
- if ((curr == snap) && ((curr & 0x1) == 0))
- return 0;
-
- /*
- * If the CPU either entered or exited an outermost interrupt,
- * SMI, NMI, or whatever handler, then we know that it executed
- * a memory barrier when doing so. So we don't need another one.
- */
- if (curr != snap)
- return 0;
-
- /* We need the CPU to execute a memory barrier. */
-
- return 1;
-}
-
-static void dyntick_save_progress_counter_sched(int cpu)
-{
- struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu);
-
- rdssp->sched_dynticks_snap = rdssp->dynticks;
-}
-
-static int rcu_qsctr_inc_needed_dyntick(int cpu)
-{
- long curr;
- long snap;
- struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu);
-
- curr = rdssp->dynticks;
- snap = rdssp->sched_dynticks_snap;
- smp_mb(); /* force ordering with cpu entering/leaving dynticks. */
-
- /*
- * If the CPU remained in dynticks mode for the entire time
- * and didn't take any interrupts, NMIs, SMIs, or whatever,
- * then it cannot be in the middle of an rcu_read_lock(), so
- * the next rcu_read_lock() it executes must use the new value
- * of the counter. Therefore, this CPU has been in a quiescent
- * state the entire time, and we don't need to wait for it.
- */
-
- if ((curr == snap) && ((curr & 0x1) == 0))
- return 0;
-
- /*
- * If the CPU passed through or entered a dynticks idle phase with
- * no active irq handlers, then, as above, this CPU has already
- * passed through a quiescent state.
- */
-
- if ((curr - snap) > 2 || (snap & 0x1) == 0)
- return 0;
-
- /* We need this CPU to go through a quiescent state. */
-
- return 1;
-}
-
-#else /* !CONFIG_NO_HZ */
-
-# define dyntick_save_progress_counter(cpu) do { } while (0)
-# define rcu_try_flip_waitack_needed(cpu) (1)
-# define rcu_try_flip_waitmb_needed(cpu) (1)
-
-# define dyntick_save_progress_counter_sched(cpu) do { } while (0)
-# define rcu_qsctr_inc_needed_dyntick(cpu) (1)
-
-#endif /* CONFIG_NO_HZ */
-
-static void save_qsctr_sched(int cpu)
-{
- struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu);
-
- rdssp->sched_qs_snap = rdssp->sched_qs;
-}
-
-static inline int rcu_qsctr_inc_needed(int cpu)
-{
- struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu);
-
- /*
- * If there has been a quiescent state, no more need to wait
- * on this CPU.
- */
-
- if (rdssp->sched_qs != rdssp->sched_qs_snap) {
- smp_mb(); /* force ordering with cpu entering schedule(). */
- return 0;
- }
-
- /* We need this CPU to go through a quiescent state. */
-
- return 1;
-}
-
-/*
- * Get here when RCU is idle. Decide whether we need to
- * move out of idle state, and return non-zero if so.
- * "Straightforward" approach for the moment, might later
- * use callback-list lengths, grace-period duration, or
- * some such to determine when to exit idle state.
- * Might also need a pre-idle test that does not acquire
- * the lock, but let's get the simple case working first...
- */
-
-static int
-rcu_try_flip_idle(void)
-{
- int cpu;
-
- RCU_TRACE_ME(rcupreempt_trace_try_flip_i1);
- if (!rcu_pending(smp_processor_id())) {
- RCU_TRACE_ME(rcupreempt_trace_try_flip_ie1);
- return 0;
- }
-
- /*
- * Do the flip.
- */
-
- RCU_TRACE_ME(rcupreempt_trace_try_flip_g1);
- rcu_ctrlblk.completed++; /* stands in for rcu_try_flip_g2 */
-
- /*
- * Need a memory barrier so that other CPUs see the new
- * counter value before they see the subsequent change of all
- * the rcu_flip_flag instances to rcu_flipped.
- */
-
- smp_mb(); /* see above block comment. */
-
- /* Now ask each CPU for acknowledgement of the flip. */
-
- for_each_cpu(cpu, to_cpumask(rcu_cpu_online_map)) {
- per_cpu(rcu_flip_flag, cpu) = rcu_flipped;
- dyntick_save_progress_counter(cpu);
- }
-
- return 1;
-}
-
-/*
- * Wait for CPUs to acknowledge the flip.
- */
-
-static int
-rcu_try_flip_waitack(void)
-{
- int cpu;
-
- RCU_TRACE_ME(rcupreempt_trace_try_flip_a1);
- for_each_cpu(cpu, to_cpumask(rcu_cpu_online_map))
- if (rcu_try_flip_waitack_needed(cpu) &&
- per_cpu(rcu_flip_flag, cpu) != rcu_flip_seen) {
- RCU_TRACE_ME(rcupreempt_trace_try_flip_ae1);
- return 0;
- }
-
- /*
- * Make sure our checks above don't bleed into subsequent
- * waiting for the sum of the counters to reach zero.
- */
-
- smp_mb(); /* see above block comment. */
- RCU_TRACE_ME(rcupreempt_trace_try_flip_a2);
- return 1;
-}
-
-/*
- * Wait for collective ``last'' counter to reach zero,
- * then tell all CPUs to do an end-of-grace-period memory barrier.
- */
-
-static int
-rcu_try_flip_waitzero(void)
-{
- int cpu;
- int lastidx = !(rcu_ctrlblk.completed & 0x1);
- int sum = 0;
-
- /* Check to see if the sum of the "last" counters is zero. */
-
- RCU_TRACE_ME(rcupreempt_trace_try_flip_z1);
- for_each_cpu(cpu, to_cpumask(rcu_cpu_online_map))
- sum += RCU_DATA_CPU(cpu)->rcu_flipctr[lastidx];
- if (sum != 0) {
- RCU_TRACE_ME(rcupreempt_trace_try_flip_ze1);
- return 0;
- }
-
- /*
- * This ensures that the other CPUs see the call for
- * memory barriers -after- the sum to zero has been
- * detected here
- */
- smp_mb(); /* ^^^^^^^^^^^^ */
-
- /* Call for a memory barrier from each CPU. */
- for_each_cpu(cpu, to_cpumask(rcu_cpu_online_map)) {
- per_cpu(rcu_mb_flag, cpu) = rcu_mb_needed;
- dyntick_save_progress_counter(cpu);
- }
-
- RCU_TRACE_ME(rcupreempt_trace_try_flip_z2);
- return 1;
-}
-
-/*
- * Wait for all CPUs to do their end-of-grace-period memory barrier.
- * Return 0 once all CPUs have done so.
- */
-
-static int
-rcu_try_flip_waitmb(void)
-{
- int cpu;
-
- RCU_TRACE_ME(rcupreempt_trace_try_flip_m1);
- for_each_cpu(cpu, to_cpumask(rcu_cpu_online_map))
- if (rcu_try_flip_waitmb_needed(cpu) &&
- per_cpu(rcu_mb_flag, cpu) != rcu_mb_done) {
- RCU_TRACE_ME(rcupreempt_trace_try_flip_me1);
- return 0;
- }
-
- smp_mb(); /* Ensure that the above checks precede any following flip. */
- RCU_TRACE_ME(rcupreempt_trace_try_flip_m2);
- return 1;
-}
-
-/*
- * Attempt a single flip of the counters. Remember, a single flip does
- * -not- constitute a grace period. Instead, the interval between
- * at least GP_STAGES consecutive flips is a grace period.
- *
- * If anyone is nuts enough to run this CONFIG_PREEMPT_RCU implementation
- * on a large SMP, they might want to use a hierarchical organization of
- * the per-CPU-counter pairs.
- */
-static void rcu_try_flip(void)
-{
- unsigned long flags;
-
- RCU_TRACE_ME(rcupreempt_trace_try_flip_1);
- if (unlikely(!spin_trylock_irqsave(&rcu_ctrlblk.fliplock, flags))) {
- RCU_TRACE_ME(rcupreempt_trace_try_flip_e1);
- return;
- }
-
- /*
- * Take the next transition(s) through the RCU grace-period
- * flip-counter state machine.
- */
-
- switch (rcu_ctrlblk.rcu_try_flip_state) {
- case rcu_try_flip_idle_state:
- if (rcu_try_flip_idle())
- rcu_ctrlblk.rcu_try_flip_state =
- rcu_try_flip_waitack_state;
- break;
- case rcu_try_flip_waitack_state:
- if (rcu_try_flip_waitack())
- rcu_ctrlblk.rcu_try_flip_state =
- rcu_try_flip_waitzero_state;
- break;
- case rcu_try_flip_waitzero_state:
- if (rcu_try_flip_waitzero())
- rcu_ctrlblk.rcu_try_flip_state =
- rcu_try_flip_waitmb_state;
- break;
- case rcu_try_flip_waitmb_state:
- if (rcu_try_flip_waitmb())
- rcu_ctrlblk.rcu_try_flip_state =
- rcu_try_flip_idle_state;
- }
- spin_unlock_irqrestore(&rcu_ctrlblk.fliplock, flags);
-}
-
-/*
- * Check to see if this CPU needs to do a memory barrier in order to
- * ensure that any prior RCU read-side critical sections have committed
- * their counter manipulations and critical-section memory references
- * before declaring the grace period to be completed.
- */
-static void rcu_check_mb(int cpu)
-{
- if (per_cpu(rcu_mb_flag, cpu) == rcu_mb_needed) {
- smp_mb(); /* Ensure RCU read-side accesses are visible. */
- per_cpu(rcu_mb_flag, cpu) = rcu_mb_done;
- }
-}
-
-void rcu_check_callbacks(int cpu, int user)
-{
- unsigned long flags;
- struct rcu_data *rdp = RCU_DATA_CPU(cpu);
-
- /*
- * If this CPU took its interrupt from user mode or from the
- * idle loop, and this is not a nested interrupt, then
- * this CPU has to have exited all prior preept-disable
- * sections of code. So increment the counter to note this.
- *
- * The memory barrier is needed to handle the case where
- * writes from a preempt-disable section of code get reordered
- * into schedule() by this CPU's write buffer. So the memory
- * barrier makes sure that the rcu_qsctr_inc() is seen by other
- * CPUs to happen after any such write.
- */
-
- if (user ||
- (idle_cpu(cpu) && !in_softirq() &&
- hardirq_count() <= (1 << HARDIRQ_SHIFT))) {
- smp_mb(); /* Guard against aggressive schedule(). */
- rcu_qsctr_inc(cpu);
- }
-
- rcu_check_mb(cpu);
- if (rcu_ctrlblk.completed == rdp->completed)
- rcu_try_flip();
- spin_lock_irqsave(&rdp->lock, flags);
- RCU_TRACE_RDP(rcupreempt_trace_check_callbacks, rdp);
- __rcu_advance_callbacks(rdp);
- if (rdp->donelist == NULL) {
- spin_unlock_irqrestore(&rdp->lock, flags);
- } else {
- spin_unlock_irqrestore(&rdp->lock, flags);
- raise_softirq(RCU_SOFTIRQ);
- }
-}
-
-/*
- * Needed by dynticks, to make sure all RCU processing has finished
- * when we go idle:
- */
-void rcu_advance_callbacks(int cpu, int user)
-{
- unsigned long flags;
- struct rcu_data *rdp = RCU_DATA_CPU(cpu);
-
- if (rcu_ctrlblk.completed == rdp->completed) {
- rcu_try_flip();
- if (rcu_ctrlblk.completed == rdp->completed)
- return;
- }
- spin_lock_irqsave(&rdp->lock, flags);
- RCU_TRACE_RDP(rcupreempt_trace_check_callbacks, rdp);
- __rcu_advance_callbacks(rdp);
- spin_unlock_irqrestore(&rdp->lock, flags);
-}
-
-#ifdef CONFIG_HOTPLUG_CPU
-#define rcu_offline_cpu_enqueue(srclist, srctail, dstlist, dsttail) do { \
- *dsttail = srclist; \
- if (srclist != NULL) { \
- dsttail = srctail; \
- srclist = NULL; \
- srctail = &srclist;\
- } \
- } while (0)
-
-void rcu_offline_cpu(int cpu)
-{
- int i;
- struct rcu_head *list = NULL;
- unsigned long flags;
- struct rcu_data *rdp = RCU_DATA_CPU(cpu);
- struct rcu_head *schedlist = NULL;
- struct rcu_head **schedtail = &schedlist;
- struct rcu_head **tail = &list;
-
- /*
- * Remove all callbacks from the newly dead CPU, retaining order.
- * Otherwise rcu_barrier() will fail
- */
-
- spin_lock_irqsave(&rdp->lock, flags);
- rcu_offline_cpu_enqueue(rdp->donelist, rdp->donetail, list, tail);
- for (i = GP_STAGES - 1; i >= 0; i--)
- rcu_offline_cpu_enqueue(rdp->waitlist[i], rdp->waittail[i],
- list, tail);
- rcu_offline_cpu_enqueue(rdp->nextlist, rdp->nexttail, list, tail);
- rcu_offline_cpu_enqueue(rdp->waitschedlist, rdp->waitschedtail,
- schedlist, schedtail);
- rcu_offline_cpu_enqueue(rdp->nextschedlist, rdp->nextschedtail,
- schedlist, schedtail);
- rdp->rcu_sched_sleeping = 0;
- spin_unlock_irqrestore(&rdp->lock, flags);
- rdp->waitlistcount = 0;
-
- /* Disengage the newly dead CPU from the grace-period computation. */
-
- spin_lock_irqsave(&rcu_ctrlblk.fliplock, flags);
- rcu_check_mb(cpu);
- if (per_cpu(rcu_flip_flag, cpu) == rcu_flipped) {
- smp_mb(); /* Subsequent counter accesses must see new value */
- per_cpu(rcu_flip_flag, cpu) = rcu_flip_seen;
- smp_mb(); /* Subsequent RCU read-side critical sections */
- /* seen -after- acknowledgement. */
- }
-
- RCU_DATA_ME()->rcu_flipctr[0] += RCU_DATA_CPU(cpu)->rcu_flipctr[0];
- RCU_DATA_ME()->rcu_flipctr[1] += RCU_DATA_CPU(cpu)->rcu_flipctr[1];
-
- RCU_DATA_CPU(cpu)->rcu_flipctr[0] = 0;
- RCU_DATA_CPU(cpu)->rcu_flipctr[1] = 0;
-
- cpumask_clear_cpu(cpu, to_cpumask(rcu_cpu_online_map));
-
- spin_unlock_irqrestore(&rcu_ctrlblk.fliplock, flags);
-
- /*
- * Place the removed callbacks on the current CPU's queue.
- * Make them all start a new grace period: simple approach,
- * in theory could starve a given set of callbacks, but
- * you would need to be doing some serious CPU hotplugging
- * to make this happen. If this becomes a problem, adding
- * a synchronize_rcu() to the hotplug path would be a simple
- * fix.
- */
-
- local_irq_save(flags); /* disable preempt till we know what lock. */
- rdp = RCU_DATA_ME();
- spin_lock(&rdp->lock);
- *rdp->nexttail = list;
- if (list)
- rdp->nexttail = tail;
- *rdp->nextschedtail = schedlist;
- if (schedlist)
- rdp->nextschedtail = schedtail;
- spin_unlock_irqrestore(&rdp->lock, flags);
-}
-
-#else /* #ifdef CONFIG_HOTPLUG_CPU */
-
-void rcu_offline_cpu(int cpu)
-{
-}
-
-#endif /* #else #ifdef CONFIG_HOTPLUG_CPU */
-
-void __cpuinit rcu_online_cpu(int cpu)
-{
- unsigned long flags;
- struct rcu_data *rdp;
-
- spin_lock_irqsave(&rcu_ctrlblk.fliplock, flags);
- cpumask_set_cpu(cpu, to_cpumask(rcu_cpu_online_map));
- spin_unlock_irqrestore(&rcu_ctrlblk.fliplock, flags);
-
- /*
- * The rcu_sched grace-period processing might have bypassed
- * this CPU, given that it was not in the rcu_cpu_online_map
- * when the grace-period scan started. This means that the
- * grace-period task might sleep. So make sure that if this
- * should happen, the first callback posted to this CPU will
- * wake up the grace-period task if need be.
- */
-
- rdp = RCU_DATA_CPU(cpu);
- spin_lock_irqsave(&rdp->lock, flags);
- rdp->rcu_sched_sleeping = 1;
- spin_unlock_irqrestore(&rdp->lock, flags);
-}
-
-static void rcu_process_callbacks(struct softirq_action *unused)
-{
- unsigned long flags;
- struct rcu_head *next, *list;
- struct rcu_data *rdp;
-
- local_irq_save(flags);
- rdp = RCU_DATA_ME();
- spin_lock(&rdp->lock);
- list = rdp->donelist;
- if (list == NULL) {
- spin_unlock_irqrestore(&rdp->lock, flags);
- return;
- }
- rdp->donelist = NULL;
- rdp->donetail = &rdp->donelist;
- RCU_TRACE_RDP(rcupreempt_trace_done_remove, rdp);
- spin_unlock_irqrestore(&rdp->lock, flags);
- while (list) {
- next = list->next;
- list->func(list);
- list = next;
- RCU_TRACE_ME(rcupreempt_trace_invoke);
- }
-}
-
-void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
-{
- unsigned long flags;
- struct rcu_data *rdp;
-
- head->func = func;
- head->next = NULL;
- local_irq_save(flags);
- rdp = RCU_DATA_ME();
- spin_lock(&rdp->lock);
- __rcu_advance_callbacks(rdp);
- *rdp->nexttail = head;
- rdp->nexttail = &head->next;
- RCU_TRACE_RDP(rcupreempt_trace_next_add, rdp);
- spin_unlock_irqrestore(&rdp->lock, flags);
-}
-EXPORT_SYMBOL_GPL(call_rcu);
-
-void call_rcu_sched(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
-{
- unsigned long flags;
- struct rcu_data *rdp;
- int wake_gp = 0;
-
- head->func = func;
- head->next = NULL;
- local_irq_save(flags);
- rdp = RCU_DATA_ME();
- spin_lock(&rdp->lock);
- *rdp->nextschedtail = head;
- rdp->nextschedtail = &head->next;
- if (rdp->rcu_sched_sleeping) {
-
- /* Grace-period processing might be sleeping... */
-
- rdp->rcu_sched_sleeping = 0;
- wake_gp = 1;
- }
- spin_unlock_irqrestore(&rdp->lock, flags);
- if (wake_gp) {
-
- /* Wake up grace-period processing, unless someone beat us. */
-
- spin_lock_irqsave(&rcu_ctrlblk.schedlock, flags);
- if (rcu_ctrlblk.sched_sleep != rcu_sched_sleeping)
- wake_gp = 0;
- rcu_ctrlblk.sched_sleep = rcu_sched_not_sleeping;
- spin_unlock_irqrestore(&rcu_ctrlblk.schedlock, flags);
- if (wake_gp)
- wake_up_interruptible(&rcu_ctrlblk.sched_wq);
- }
-}
-EXPORT_SYMBOL_GPL(call_rcu_sched);
-
-/*
- * Wait until all currently running preempt_disable() code segments
- * (including hardware-irq-disable segments) complete. Note that
- * in -rt this does -not- necessarily result in all currently executing
- * interrupt -handlers- having completed.
- */
-void __synchronize_sched(void)
-{
- struct rcu_synchronize rcu;
-
- if (num_online_cpus() == 1)
- return; /* blocking is gp if only one CPU! */
-
- init_completion(&rcu.completion);
- /* Will wake me after RCU finished. */
- call_rcu_sched(&rcu.head, wakeme_after_rcu);
- /* Wait for it. */
- wait_for_completion(&rcu.completion);
-}
-EXPORT_SYMBOL_GPL(__synchronize_sched);
-
-/*
- * kthread function that manages call_rcu_sched grace periods.
- */
-static int rcu_sched_grace_period(void *arg)
-{
- int couldsleep; /* might sleep after current pass. */
- int couldsleepnext = 0; /* might sleep after next pass. */
- int cpu;
- unsigned long flags;
- struct rcu_data *rdp;
- int ret;
-
- /*
- * Each pass through the following loop handles one
- * rcu_sched grace period cycle.
- */
- do {
- /* Save each CPU's current state. */
-
- for_each_online_cpu(cpu) {
- dyntick_save_progress_counter_sched(cpu);
- save_qsctr_sched(cpu);
- }
-
- /*
- * Sleep for about an RCU grace-period's worth to
- * allow better batching and to consume less CPU.
- */
- schedule_timeout_interruptible(RCU_SCHED_BATCH_TIME);
-
- /*
- * If there was nothing to do last time, prepare to
- * sleep at the end of the current grace period cycle.
- */
- couldsleep = couldsleepnext;
- couldsleepnext = 1;
- if (couldsleep) {
- spin_lock_irqsave(&rcu_ctrlblk.schedlock, flags);
- rcu_ctrlblk.sched_sleep = rcu_sched_sleep_prep;
- spin_unlock_irqrestore(&rcu_ctrlblk.schedlock, flags);
- }
-
- /*
- * Wait on each CPU in turn to have either visited
- * a quiescent state or been in dynticks-idle mode.
- */
- for_each_online_cpu(cpu) {
- while (rcu_qsctr_inc_needed(cpu) &&
- rcu_qsctr_inc_needed_dyntick(cpu)) {
- /* resched_cpu(cpu); @@@ */
- schedule_timeout_interruptible(1);
- }
- }
-
- /* Advance callbacks for each CPU. */
-
- for_each_online_cpu(cpu) {
-
- rdp = RCU_DATA_CPU(cpu);
- spin_lock_irqsave(&rdp->lock, flags);
-
- /*
- * We are running on this CPU irq-disabled, so no
- * CPU can go offline until we re-enable irqs.
- * The current CPU might have already gone
- * offline (between the for_each_offline_cpu and
- * the spin_lock_irqsave), but in that case all its
- * callback lists will be empty, so no harm done.
- *
- * Advance the callbacks! We share normal RCU's
- * donelist, since callbacks are invoked the
- * same way in either case.
- */
- if (rdp->waitschedlist != NULL) {
- *rdp->donetail = rdp->waitschedlist;
- rdp->donetail = rdp->waitschedtail;
-
- /*
- * Next rcu_check_callbacks() will
- * do the required raise_softirq().
- */
- }
- if (rdp->nextschedlist != NULL) {
- rdp->waitschedlist = rdp->nextschedlist;
- rdp->waitschedtail = rdp->nextschedtail;
- couldsleep = 0;
- couldsleepnext = 0;
- } else {
- rdp->waitschedlist = NULL;
- rdp->waitschedtail = &rdp->waitschedlist;
- }
- rdp->nextschedlist = NULL;
- rdp->nextschedtail = &rdp->nextschedlist;
-
- /* Mark sleep intention. */
-
- rdp->rcu_sched_sleeping = couldsleep;
-
- spin_unlock_irqrestore(&rdp->lock, flags);
- }
-
- /* If we saw callbacks on the last scan, go deal with them. */
-
- if (!couldsleep)
- continue;
-
- /* Attempt to block... */
-
- spin_lock_irqsave(&rcu_ctrlblk.schedlock, flags);
- if (rcu_ctrlblk.sched_sleep != rcu_sched_sleep_prep) {
-
- /*
- * Someone posted a callback after we scanned.
- * Go take care of it.
- */
- spin_unlock_irqrestore(&rcu_ctrlblk.schedlock, flags);
- couldsleepnext = 0;
- continue;
- }
-
- /* Block until the next person posts a callback. */
-
- rcu_ctrlblk.sched_sleep = rcu_sched_sleeping;
- spin_unlock_irqrestore(&rcu_ctrlblk.schedlock, flags);
- ret = 0; /* unused */
- __wait_event_interruptible(rcu_ctrlblk.sched_wq,
- rcu_ctrlblk.sched_sleep != rcu_sched_sleeping,
- ret);
-
- couldsleepnext = 0;
-
- } while (!kthread_should_stop());
-
- return (0);
-}
-
-/*
- * Check to see if any future RCU-related work will need to be done
- * by the current CPU, even if none need be done immediately, returning
- * 1 if so. Assumes that notifiers would take care of handling any
- * outstanding requests from the RCU core.
- *
- * This function is part of the RCU implementation; it is -not-
- * an exported member of the RCU API.
- */
-int rcu_needs_cpu(int cpu)
-{
- struct rcu_data *rdp = RCU_DATA_CPU(cpu);
-
- return (rdp->donelist != NULL ||
- !!rdp->waitlistcount ||
- rdp->nextlist != NULL ||
- rdp->nextschedlist != NULL ||
- rdp->waitschedlist != NULL);
-}
-
-int rcu_pending(int cpu)
-{
- struct rcu_data *rdp = RCU_DATA_CPU(cpu);
-
- /* The CPU has at least one callback queued somewhere. */
-
- if (rdp->donelist != NULL ||
- !!rdp->waitlistcount ||
- rdp->nextlist != NULL ||
- rdp->nextschedlist != NULL ||
- rdp->waitschedlist != NULL)
- return 1;
-
- /* The RCU core needs an acknowledgement from this CPU. */
-
- if ((per_cpu(rcu_flip_flag, cpu) == rcu_flipped) ||
- (per_cpu(rcu_mb_flag, cpu) == rcu_mb_needed))
- return 1;
-
- /* This CPU has fallen behind the global grace-period number. */
-
- if (rdp->completed != rcu_ctrlblk.completed)
- return 1;
-
- /* Nothing needed from this CPU. */
-
- return 0;
-}
-
-static int __cpuinit rcu_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
-{
- long cpu = (long)hcpu;
-
- switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- rcu_online_cpu(cpu);
- break;
- case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- rcu_offline_cpu(cpu);
- break;
- default:
- break;
- }
- return NOTIFY_OK;
-}
-
-static struct notifier_block __cpuinitdata rcu_nb = {
- .notifier_call = rcu_cpu_notify,
-};
-
-void __init __rcu_init(void)
-{
- int cpu;
- int i;
- struct rcu_data *rdp;
-
- printk(KERN_NOTICE "Preemptible RCU implementation.\n");
- for_each_possible_cpu(cpu) {
- rdp = RCU_DATA_CPU(cpu);
- spin_lock_init(&rdp->lock);
- rdp->completed = 0;
- rdp->waitlistcount = 0;
- rdp->nextlist = NULL;
- rdp->nexttail = &rdp->nextlist;
- for (i = 0; i < GP_STAGES; i++) {
- rdp->waitlist[i] = NULL;
- rdp->waittail[i] = &rdp->waitlist[i];
- }
- rdp->donelist = NULL;
- rdp->donetail = &rdp->donelist;
- rdp->rcu_flipctr[0] = 0;
- rdp->rcu_flipctr[1] = 0;
- rdp->nextschedlist = NULL;
- rdp->nextschedtail = &rdp->nextschedlist;
- rdp->waitschedlist = NULL;
- rdp->waitschedtail = &rdp->waitschedlist;
- rdp->rcu_sched_sleeping = 0;
- }
- register_cpu_notifier(&rcu_nb);
-
- /*
- * We don't need protection against CPU-Hotplug here
- * since
- * a) If a CPU comes online while we are iterating over the
- * cpu_online_mask below, we would only end up making a
- * duplicate call to rcu_online_cpu() which sets the corresponding
- * CPU's mask in the rcu_cpu_online_map.
- *
- * b) A CPU cannot go offline at this point in time since the user
- * does not have access to the sysfs interface, nor do we
- * suspend the system.
- */
- for_each_online_cpu(cpu)
- rcu_cpu_notify(&rcu_nb, CPU_UP_PREPARE, (void *)(long) cpu);
-
- open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
-}
-
-/*
- * Late-boot-time RCU initialization that must wait until after scheduler
- * has been initialized.
- */
-void __init rcu_init_sched(void)
-{
- rcu_sched_grace_period_task = kthread_run(rcu_sched_grace_period,
- NULL,
- "rcu_sched_grace_period");
- WARN_ON(IS_ERR(rcu_sched_grace_period_task));
-}
-
-#ifdef CONFIG_RCU_TRACE
-long *rcupreempt_flipctr(int cpu)
-{
- return &RCU_DATA_CPU(cpu)->rcu_flipctr[0];
-}
-EXPORT_SYMBOL_GPL(rcupreempt_flipctr);
-
-int rcupreempt_flip_flag(int cpu)
-{
- return per_cpu(rcu_flip_flag, cpu);
-}
-EXPORT_SYMBOL_GPL(rcupreempt_flip_flag);
-
-int rcupreempt_mb_flag(int cpu)
-{
- return per_cpu(rcu_mb_flag, cpu);
-}
-EXPORT_SYMBOL_GPL(rcupreempt_mb_flag);
-
-char *rcupreempt_try_flip_state_name(void)
-{
- return rcu_try_flip_state_names[rcu_ctrlblk.rcu_try_flip_state];
-}
-EXPORT_SYMBOL_GPL(rcupreempt_try_flip_state_name);
-
-struct rcupreempt_trace *rcupreempt_trace_cpu(int cpu)
-{
- struct rcu_data *rdp = RCU_DATA_CPU(cpu);
-
- return &rdp->trace;
-}
-EXPORT_SYMBOL_GPL(rcupreempt_trace_cpu);
-
-#endif /* #ifdef RCU_TRACE */
diff --git a/kernel/rcupreempt_trace.c b/kernel/rcupreempt_trace.c
deleted file mode 100644
index 7c2665cac172..000000000000
--- a/kernel/rcupreempt_trace.c
+++ /dev/null
@@ -1,334 +0,0 @@
-/*
- * Read-Copy Update tracing for realtime implementation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *
- * Copyright IBM Corporation, 2006
- *
- * Papers: http://www.rdrop.com/users/paulmck/RCU
- *
- * For detailed explanation of Read-Copy Update mechanism see -
- * Documentation/RCU/ *.txt
- *
- */
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/spinlock.h>
-#include <linux/smp.h>
-#include <linux/rcupdate.h>
-#include <linux/interrupt.h>
-#include <linux/sched.h>
-#include <asm/atomic.h>
-#include <linux/bitops.h>
-#include <linux/module.h>
-#include <linux/completion.h>
-#include <linux/moduleparam.h>
-#include <linux/percpu.h>
-#include <linux/notifier.h>
-#include <linux/cpu.h>
-#include <linux/mutex.h>
-#include <linux/rcupreempt_trace.h>
-#include <linux/debugfs.h>
-
-static struct mutex rcupreempt_trace_mutex;
-static char *rcupreempt_trace_buf;
-#define RCUPREEMPT_TRACE_BUF_SIZE 4096
-
-void rcupreempt_trace_move2done(struct rcupreempt_trace *trace)
-{
- trace->done_length += trace->wait_length;
- trace->done_add += trace->wait_length;
- trace->wait_length = 0;
-}
-void rcupreempt_trace_move2wait(struct rcupreempt_trace *trace)
-{
- trace->wait_length += trace->next_length;
- trace->wait_add += trace->next_length;
- trace->next_length = 0;
-}
-void rcupreempt_trace_try_flip_1(struct rcupreempt_trace *trace)
-{
- atomic_inc(&trace->rcu_try_flip_1);
-}
-void rcupreempt_trace_try_flip_e1(struct rcupreempt_trace *trace)
-{
- atomic_inc(&trace->rcu_try_flip_e1);
-}
-void rcupreempt_trace_try_flip_i1(struct rcupreempt_trace *trace)
-{
- trace->rcu_try_flip_i1++;
-}
-void rcupreempt_trace_try_flip_ie1(struct rcupreempt_trace *trace)
-{
- trace->rcu_try_flip_ie1++;
-}
-void rcupreempt_trace_try_flip_g1(struct rcupreempt_trace *trace)
-{
- trace->rcu_try_flip_g1++;
-}
-void rcupreempt_trace_try_flip_a1(struct rcupreempt_trace *trace)
-{
- trace->rcu_try_flip_a1++;
-}
-void rcupreempt_trace_try_flip_ae1(struct rcupreempt_trace *trace)
-{
- trace->rcu_try_flip_ae1++;
-}
-void rcupreempt_trace_try_flip_a2(struct rcupreempt_trace *trace)
-{
- trace->rcu_try_flip_a2++;
-}
-void rcupreempt_trace_try_flip_z1(struct rcupreempt_trace *trace)
-{
- trace->rcu_try_flip_z1++;
-}
-void rcupreempt_trace_try_flip_ze1(struct rcupreempt_trace *trace)
-{
- trace->rcu_try_flip_ze1++;
-}
-void rcupreempt_trace_try_flip_z2(struct rcupreempt_trace *trace)
-{
- trace->rcu_try_flip_z2++;
-}
-void rcupreempt_trace_try_flip_m1(struct rcupreempt_trace *trace)
-{
- trace->rcu_try_flip_m1++;
-}
-void rcupreempt_trace_try_flip_me1(struct rcupreempt_trace *trace)
-{
- trace->rcu_try_flip_me1++;
-}
-void rcupreempt_trace_try_flip_m2(struct rcupreempt_trace *trace)
-{
- trace->rcu_try_flip_m2++;
-}
-void rcupreempt_trace_check_callbacks(struct rcupreempt_trace *trace)
-{
- trace->rcu_check_callbacks++;
-}
-void rcupreempt_trace_done_remove(struct rcupreempt_trace *trace)
-{
- trace->done_remove += trace->done_length;
- trace->done_length = 0;
-}
-void rcupreempt_trace_invoke(struct rcupreempt_trace *trace)
-{
- atomic_inc(&trace->done_invoked);
-}
-void rcupreempt_trace_next_add(struct rcupreempt_trace *trace)
-{
- trace->next_add++;
- trace->next_length++;
-}
-
-static void rcupreempt_trace_sum(struct rcupreempt_trace *sp)
-{
- struct rcupreempt_trace *cp;
- int cpu;
-
- memset(sp, 0, sizeof(*sp));
- for_each_possible_cpu(cpu) {
- cp = rcupreempt_trace_cpu(cpu);
- sp->next_length += cp->next_length;
- sp->next_add += cp->next_add;
- sp->wait_length += cp->wait_length;
- sp->wait_add += cp->wait_add;
- sp->done_length += cp->done_length;
- sp->done_add += cp->done_add;
- sp->done_remove += cp->done_remove;
- atomic_add(atomic_read(&cp->done_invoked), &sp->done_invoked);
- sp->rcu_check_callbacks += cp->rcu_check_callbacks;
- atomic_add(atomic_read(&cp->rcu_try_flip_1),
- &sp->rcu_try_flip_1);
- atomic_add(atomic_read(&cp->rcu_try_flip_e1),
- &sp->rcu_try_flip_e1);
- sp->rcu_try_flip_i1 += cp->rcu_try_flip_i1;
- sp->rcu_try_flip_ie1 += cp->rcu_try_flip_ie1;
- sp->rcu_try_flip_g1 += cp->rcu_try_flip_g1;
- sp->rcu_try_flip_a1 += cp->rcu_try_flip_a1;
- sp->rcu_try_flip_ae1 += cp->rcu_try_flip_ae1;
- sp->rcu_try_flip_a2 += cp->rcu_try_flip_a2;
- sp->rcu_try_flip_z1 += cp->rcu_try_flip_z1;
- sp->rcu_try_flip_ze1 += cp->rcu_try_flip_ze1;
- sp->rcu_try_flip_z2 += cp->rcu_try_flip_z2;
- sp->rcu_try_flip_m1 += cp->rcu_try_flip_m1;
- sp->rcu_try_flip_me1 += cp->rcu_try_flip_me1;
- sp->rcu_try_flip_m2 += cp->rcu_try_flip_m2;
- }
-}
-
-static ssize_t rcustats_read(struct file *filp, char __user *buffer,
- size_t count, loff_t *ppos)
-{
- struct rcupreempt_trace trace;
- ssize_t bcount;
- int cnt = 0;
-
- rcupreempt_trace_sum(&trace);
- mutex_lock(&rcupreempt_trace_mutex);
- snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt,
- "ggp=%ld rcc=%ld\n",
- rcu_batches_completed(),
- trace.rcu_check_callbacks);
- snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt,
- "na=%ld nl=%ld wa=%ld wl=%ld da=%ld dl=%ld dr=%ld di=%d\n"
- "1=%d e1=%d i1=%ld ie1=%ld g1=%ld a1=%ld ae1=%ld a2=%ld\n"
- "z1=%ld ze1=%ld z2=%ld m1=%ld me1=%ld m2=%ld\n",
-
- trace.next_add, trace.next_length,
- trace.wait_add, trace.wait_length,
- trace.done_add, trace.done_length,
- trace.done_remove, atomic_read(&trace.done_invoked),
- atomic_read(&trace.rcu_try_flip_1),
- atomic_read(&trace.rcu_try_flip_e1),
- trace.rcu_try_flip_i1, trace.rcu_try_flip_ie1,
- trace.rcu_try_flip_g1,
- trace.rcu_try_flip_a1, trace.rcu_try_flip_ae1,
- trace.rcu_try_flip_a2,
- trace.rcu_try_flip_z1, trace.rcu_try_flip_ze1,
- trace.rcu_try_flip_z2,
- trace.rcu_try_flip_m1, trace.rcu_try_flip_me1,
- trace.rcu_try_flip_m2);
- bcount = simple_read_from_buffer(buffer, count, ppos,
- rcupreempt_trace_buf, strlen(rcupreempt_trace_buf));
- mutex_unlock(&rcupreempt_trace_mutex);
- return bcount;
-}
-
-static ssize_t rcugp_read(struct file *filp, char __user *buffer,
- size_t count, loff_t *ppos)
-{
- long oldgp = rcu_batches_completed();
- ssize_t bcount;
-
- mutex_lock(&rcupreempt_trace_mutex);
- synchronize_rcu();
- snprintf(rcupreempt_trace_buf, RCUPREEMPT_TRACE_BUF_SIZE,
- "oldggp=%ld newggp=%ld\n", oldgp, rcu_batches_completed());
- bcount = simple_read_from_buffer(buffer, count, ppos,
- rcupreempt_trace_buf, strlen(rcupreempt_trace_buf));
- mutex_unlock(&rcupreempt_trace_mutex);
- return bcount;
-}
-
-static ssize_t rcuctrs_read(struct file *filp, char __user *buffer,
- size_t count, loff_t *ppos)
-{
- int cnt = 0;
- int cpu;
- int f = rcu_batches_completed() & 0x1;
- ssize_t bcount;
-
- mutex_lock(&rcupreempt_trace_mutex);
-
- cnt += snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE,
- "CPU last cur F M\n");
- for_each_online_cpu(cpu) {
- long *flipctr = rcupreempt_flipctr(cpu);
- cnt += snprintf(&rcupreempt_trace_buf[cnt],
- RCUPREEMPT_TRACE_BUF_SIZE - cnt,
- "%3d %4ld %3ld %d %d\n",
- cpu,
- flipctr[!f],
- flipctr[f],
- rcupreempt_flip_flag(cpu),
- rcupreempt_mb_flag(cpu));
- }
- cnt += snprintf(&rcupreempt_trace_buf[cnt],
- RCUPREEMPT_TRACE_BUF_SIZE - cnt,
- "ggp = %ld, state = %s\n",
- rcu_batches_completed(),
- rcupreempt_try_flip_state_name());
- cnt += snprintf(&rcupreempt_trace_buf[cnt],
- RCUPREEMPT_TRACE_BUF_SIZE - cnt,
- "\n");
- bcount = simple_read_from_buffer(buffer, count, ppos,
- rcupreempt_trace_buf, strlen(rcupreempt_trace_buf));
- mutex_unlock(&rcupreempt_trace_mutex);
- return bcount;
-}
-
-static struct file_operations rcustats_fops = {
- .owner = THIS_MODULE,
- .read = rcustats_read,
-};
-
-static struct file_operations rcugp_fops = {
- .owner = THIS_MODULE,
- .read = rcugp_read,
-};
-
-static struct file_operations rcuctrs_fops = {
- .owner = THIS_MODULE,
- .read = rcuctrs_read,
-};
-
-static struct dentry *rcudir, *statdir, *ctrsdir, *gpdir;
-static int rcupreempt_debugfs_init(void)
-{
- rcudir = debugfs_create_dir("rcu", NULL);
- if (!rcudir)
- goto out;
- statdir = debugfs_create_file("rcustats", 0444, rcudir,
- NULL, &rcustats_fops);
- if (!statdir)
- goto free_out;
-
- gpdir = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops);
- if (!gpdir)
- goto free_out;
-
- ctrsdir = debugfs_create_file("rcuctrs", 0444, rcudir,
- NULL, &rcuctrs_fops);
- if (!ctrsdir)
- goto free_out;
- return 0;
-free_out:
- if (statdir)
- debugfs_remove(statdir);
- if (gpdir)
- debugfs_remove(gpdir);
- debugfs_remove(rcudir);
-out:
- return 1;
-}
-
-static int __init rcupreempt_trace_init(void)
-{
- int ret;
-
- mutex_init(&rcupreempt_trace_mutex);
- rcupreempt_trace_buf = kmalloc(RCUPREEMPT_TRACE_BUF_SIZE, GFP_KERNEL);
- if (!rcupreempt_trace_buf)
- return 1;
- ret = rcupreempt_debugfs_init();
- if (ret)
- kfree(rcupreempt_trace_buf);
- return ret;
-}
-
-static void __exit rcupreempt_trace_cleanup(void)
-{
- debugfs_remove(statdir);
- debugfs_remove(gpdir);
- debugfs_remove(ctrsdir);
- debugfs_remove(rcudir);
- kfree(rcupreempt_trace_buf);
-}
-
-
-module_init(rcupreempt_trace_init);
-module_exit(rcupreempt_trace_cleanup);
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 9b4a975a4b4a..b33db539a8ad 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -257,14 +257,14 @@ struct rcu_torture_ops {
void (*init)(void);
void (*cleanup)(void);
int (*readlock)(void);
- void (*readdelay)(struct rcu_random_state *rrsp);
+ void (*read_delay)(struct rcu_random_state *rrsp);
void (*readunlock)(int idx);
int (*completed)(void);
- void (*deferredfree)(struct rcu_torture *p);
+ void (*deferred_free)(struct rcu_torture *p);
void (*sync)(void);
void (*cb_barrier)(void);
int (*stats)(char *page);
- int irqcapable;
+ int irq_capable;
char *name;
};
static struct rcu_torture_ops *cur_ops = NULL;
@@ -320,7 +320,7 @@ rcu_torture_cb(struct rcu_head *p)
rp->rtort_mbtest = 0;
rcu_torture_free(rp);
} else
- cur_ops->deferredfree(rp);
+ cur_ops->deferred_free(rp);
}
static void rcu_torture_deferred_free(struct rcu_torture *p)
@@ -329,18 +329,18 @@ static void rcu_torture_deferred_free(struct rcu_torture *p)
}
static struct rcu_torture_ops rcu_ops = {
- .init = NULL,
- .cleanup = NULL,
- .readlock = rcu_torture_read_lock,
- .readdelay = rcu_read_delay,
- .readunlock = rcu_torture_read_unlock,
- .completed = rcu_torture_completed,
- .deferredfree = rcu_torture_deferred_free,
- .sync = synchronize_rcu,
- .cb_barrier = rcu_barrier,
- .stats = NULL,
- .irqcapable = 1,
- .name = "rcu"
+ .init = NULL,
+ .cleanup = NULL,
+ .readlock = rcu_torture_read_lock,
+ .read_delay = rcu_read_delay,
+ .readunlock = rcu_torture_read_unlock,
+ .completed = rcu_torture_completed,
+ .deferred_free = rcu_torture_deferred_free,
+ .sync = synchronize_rcu,
+ .cb_barrier = rcu_barrier,
+ .stats = NULL,
+ .irq_capable = 1,
+ .name = "rcu"
};
static void rcu_sync_torture_deferred_free(struct rcu_torture *p)
@@ -370,18 +370,18 @@ static void rcu_sync_torture_init(void)
}
static struct rcu_torture_ops rcu_sync_ops = {
- .init = rcu_sync_torture_init,
- .cleanup = NULL,
- .readlock = rcu_torture_read_lock,
- .readdelay = rcu_read_delay,
- .readunlock = rcu_torture_read_unlock,
- .completed = rcu_torture_completed,
- .deferredfree = rcu_sync_torture_deferred_free,
- .sync = synchronize_rcu,
- .cb_barrier = NULL,
- .stats = NULL,
- .irqcapable = 1,
- .name = "rcu_sync"
+ .init = rcu_sync_torture_init,
+ .cleanup = NULL,
+ .readlock = rcu_torture_read_lock,
+ .read_delay = rcu_read_delay,
+ .readunlock = rcu_torture_read_unlock,
+ .completed = rcu_torture_completed,
+ .deferred_free = rcu_sync_torture_deferred_free,
+ .sync = synchronize_rcu,
+ .cb_barrier = NULL,
+ .stats = NULL,
+ .irq_capable = 1,
+ .name = "rcu_sync"
};
/*
@@ -432,33 +432,33 @@ static void rcu_bh_torture_synchronize(void)
}
static struct rcu_torture_ops rcu_bh_ops = {
- .init = NULL,
- .cleanup = NULL,
- .readlock = rcu_bh_torture_read_lock,
- .readdelay = rcu_read_delay, /* just reuse rcu's version. */
- .readunlock = rcu_bh_torture_read_unlock,
- .completed = rcu_bh_torture_completed,
- .deferredfree = rcu_bh_torture_deferred_free,
- .sync = rcu_bh_torture_synchronize,
- .cb_barrier = rcu_barrier_bh,
- .stats = NULL,
- .irqcapable = 1,
- .name = "rcu_bh"
+ .init = NULL,
+ .cleanup = NULL,
+ .readlock = rcu_bh_torture_read_lock,
+ .read_delay = rcu_read_delay, /* just reuse rcu's version. */
+ .readunlock = rcu_bh_torture_read_unlock,
+ .completed = rcu_bh_torture_completed,
+ .deferred_free = rcu_bh_torture_deferred_free,
+ .sync = rcu_bh_torture_synchronize,
+ .cb_barrier = rcu_barrier_bh,
+ .stats = NULL,
+ .irq_capable = 1,
+ .name = "rcu_bh"
};
static struct rcu_torture_ops rcu_bh_sync_ops = {
- .init = rcu_sync_torture_init,
- .cleanup = NULL,
- .readlock = rcu_bh_torture_read_lock,
- .readdelay = rcu_read_delay, /* just reuse rcu's version. */
- .readunlock = rcu_bh_torture_read_unlock,
- .completed = rcu_bh_torture_completed,
- .deferredfree = rcu_sync_torture_deferred_free,
- .sync = rcu_bh_torture_synchronize,
- .cb_barrier = NULL,
- .stats = NULL,
- .irqcapable = 1,
- .name = "rcu_bh_sync"
+ .init = rcu_sync_torture_init,
+ .cleanup = NULL,
+ .readlock = rcu_bh_torture_read_lock,
+ .read_delay = rcu_read_delay, /* just reuse rcu's version. */
+ .readunlock = rcu_bh_torture_read_unlock,
+ .completed = rcu_bh_torture_completed,
+ .deferred_free = rcu_sync_torture_deferred_free,
+ .sync = rcu_bh_torture_synchronize,
+ .cb_barrier = NULL,
+ .stats = NULL,
+ .irq_capable = 1,
+ .name = "rcu_bh_sync"
};
/*
@@ -530,17 +530,17 @@ static int srcu_torture_stats(char *page)
}
static struct rcu_torture_ops srcu_ops = {
- .init = srcu_torture_init,
- .cleanup = srcu_torture_cleanup,
- .readlock = srcu_torture_read_lock,
- .readdelay = srcu_read_delay,
- .readunlock = srcu_torture_read_unlock,
- .completed = srcu_torture_completed,
- .deferredfree = rcu_sync_torture_deferred_free,
- .sync = srcu_torture_synchronize,
- .cb_barrier = NULL,
- .stats = srcu_torture_stats,
- .name = "srcu"
+ .init = srcu_torture_init,
+ .cleanup = srcu_torture_cleanup,
+ .readlock = srcu_torture_read_lock,
+ .read_delay = srcu_read_delay,
+ .readunlock = srcu_torture_read_unlock,
+ .completed = srcu_torture_completed,
+ .deferred_free = rcu_sync_torture_deferred_free,
+ .sync = srcu_torture_synchronize,
+ .cb_barrier = NULL,
+ .stats = srcu_torture_stats,
+ .name = "srcu"
};
/*
@@ -574,32 +574,49 @@ static void sched_torture_synchronize(void)
}
static struct rcu_torture_ops sched_ops = {
- .init = rcu_sync_torture_init,
- .cleanup = NULL,
- .readlock = sched_torture_read_lock,
- .readdelay = rcu_read_delay, /* just reuse rcu's version. */
- .readunlock = sched_torture_read_unlock,
- .completed = sched_torture_completed,
- .deferredfree = rcu_sched_torture_deferred_free,
- .sync = sched_torture_synchronize,
- .cb_barrier = rcu_barrier_sched,
- .stats = NULL,
- .irqcapable = 1,
- .name = "sched"
+ .init = rcu_sync_torture_init,
+ .cleanup = NULL,
+ .readlock = sched_torture_read_lock,
+ .read_delay = rcu_read_delay, /* just reuse rcu's version. */
+ .readunlock = sched_torture_read_unlock,
+ .completed = sched_torture_completed,
+ .deferred_free = rcu_sched_torture_deferred_free,
+ .sync = sched_torture_synchronize,
+ .cb_barrier = rcu_barrier_sched,
+ .stats = NULL,
+ .irq_capable = 1,
+ .name = "sched"
};
static struct rcu_torture_ops sched_ops_sync = {
- .init = rcu_sync_torture_init,
- .cleanup = NULL,
- .readlock = sched_torture_read_lock,
- .readdelay = rcu_read_delay, /* just reuse rcu's version. */
- .readunlock = sched_torture_read_unlock,
- .completed = sched_torture_completed,
- .deferredfree = rcu_sync_torture_deferred_free,
- .sync = sched_torture_synchronize,
- .cb_barrier = NULL,
- .stats = NULL,
- .name = "sched_sync"
+ .init = rcu_sync_torture_init,
+ .cleanup = NULL,
+ .readlock = sched_torture_read_lock,
+ .read_delay = rcu_read_delay, /* just reuse rcu's version. */
+ .readunlock = sched_torture_read_unlock,
+ .completed = sched_torture_completed,
+ .deferred_free = rcu_sync_torture_deferred_free,
+ .sync = sched_torture_synchronize,
+ .cb_barrier = NULL,
+ .stats = NULL,
+ .name = "sched_sync"
+};
+
+extern int rcu_expedited_torture_stats(char *page);
+
+static struct rcu_torture_ops sched_expedited_ops = {
+ .init = rcu_sync_torture_init,
+ .cleanup = NULL,
+ .readlock = sched_torture_read_lock,
+ .read_delay = rcu_read_delay, /* just reuse rcu's version. */
+ .readunlock = sched_torture_read_unlock,
+ .completed = sched_torture_completed,
+ .deferred_free = rcu_sync_torture_deferred_free,
+ .sync = synchronize_sched_expedited,
+ .cb_barrier = NULL,
+ .stats = rcu_expedited_torture_stats,
+ .irq_capable = 1,
+ .name = "sched_expedited"
};
/*
@@ -635,7 +652,7 @@ rcu_torture_writer(void *arg)
i = RCU_TORTURE_PIPE_LEN;
atomic_inc(&rcu_torture_wcount[i]);
old_rp->rtort_pipe_count++;
- cur_ops->deferredfree(old_rp);
+ cur_ops->deferred_free(old_rp);
}
rcu_torture_current_version++;
oldbatch = cur_ops->completed();
@@ -700,7 +717,7 @@ static void rcu_torture_timer(unsigned long unused)
if (p->rtort_mbtest == 0)
atomic_inc(&n_rcu_torture_mberror);
spin_lock(&rand_lock);
- cur_ops->readdelay(&rand);
+ cur_ops->read_delay(&rand);
n_rcu_torture_timers++;
spin_unlock(&rand_lock);
preempt_disable();
@@ -738,11 +755,11 @@ rcu_torture_reader(void *arg)
VERBOSE_PRINTK_STRING("rcu_torture_reader task started");
set_user_nice(current, 19);
- if (irqreader && cur_ops->irqcapable)
+ if (irqreader && cur_ops->irq_capable)
setup_timer_on_stack(&t, rcu_torture_timer, 0);
do {
- if (irqreader && cur_ops->irqcapable) {
+ if (irqreader && cur_ops->irq_capable) {
if (!timer_pending(&t))
mod_timer(&t, 1);
}
@@ -757,7 +774,7 @@ rcu_torture_reader(void *arg)
}
if (p->rtort_mbtest == 0)
atomic_inc(&n_rcu_torture_mberror);
- cur_ops->readdelay(&rand);
+ cur_ops->read_delay(&rand);
preempt_disable();
pipe_count = p->rtort_pipe_count;
if (pipe_count > RCU_TORTURE_PIPE_LEN) {
@@ -778,7 +795,7 @@ rcu_torture_reader(void *arg)
} while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
rcutorture_shutdown_absorb("rcu_torture_reader");
- if (irqreader && cur_ops->irqcapable)
+ if (irqreader && cur_ops->irq_capable)
del_timer_sync(&t);
while (!kthread_should_stop())
schedule_timeout_uninterruptible(1);
@@ -1078,6 +1095,7 @@ rcu_torture_init(void)
int firsterr = 0;
static struct rcu_torture_ops *torture_ops[] =
{ &rcu_ops, &rcu_sync_ops, &rcu_bh_ops, &rcu_bh_sync_ops,
+ &sched_expedited_ops,
&srcu_ops, &sched_ops, &sched_ops_sync, };
mutex_lock(&fullstop_mutex);
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 7717b95c2027..6b11b07cfe7f 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -35,6 +35,7 @@
#include <linux/rcupdate.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
+#include <linux/nmi.h>
#include <asm/atomic.h>
#include <linux/bitops.h>
#include <linux/module.h>
@@ -46,6 +47,8 @@
#include <linux/mutex.h>
#include <linux/time.h>
+#include "rcutree.h"
+
#ifdef CONFIG_DEBUG_LOCK_ALLOC
static struct lock_class_key rcu_lock_key;
struct lockdep_map rcu_lock_map =
@@ -72,30 +75,59 @@ EXPORT_SYMBOL_GPL(rcu_lock_map);
.n_force_qs_ngp = 0, \
}
-struct rcu_state rcu_state = RCU_STATE_INITIALIZER(rcu_state);
-DEFINE_PER_CPU(struct rcu_data, rcu_data);
+struct rcu_state rcu_sched_state = RCU_STATE_INITIALIZER(rcu_sched_state);
+DEFINE_PER_CPU(struct rcu_data, rcu_sched_data);
struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh_state);
DEFINE_PER_CPU(struct rcu_data, rcu_bh_data);
+extern long rcu_batches_completed_sched(void);
+static struct rcu_node *rcu_get_root(struct rcu_state *rsp);
+static void cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp,
+ struct rcu_node *rnp, unsigned long flags);
+static void cpu_quiet_msk_finish(struct rcu_state *rsp, unsigned long flags);
+#ifdef CONFIG_HOTPLUG_CPU
+static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp);
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+static void __rcu_process_callbacks(struct rcu_state *rsp,
+ struct rcu_data *rdp);
+static void __call_rcu(struct rcu_head *head,
+ void (*func)(struct rcu_head *rcu),
+ struct rcu_state *rsp);
+static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp);
+static void __cpuinit rcu_init_percpu_data(int cpu, struct rcu_state *rsp,
+ int preemptable);
+
+#include "rcutree_plugin.h"
+
/*
- * Increment the quiescent state counter.
- * The counter is a bit degenerated: We do not need to know
+ * Note a quiescent state. Because we do not need to know
* how many quiescent states passed, just if there was at least
- * one since the start of the grace period. Thus just a flag.
+ * one since the start of the grace period, this just sets a flag.
*/
-void rcu_qsctr_inc(int cpu)
+void rcu_sched_qs(int cpu)
{
- struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
+ unsigned long flags;
+ struct rcu_data *rdp;
+
+ local_irq_save(flags);
+ rdp = &per_cpu(rcu_sched_data, cpu);
rdp->passed_quiesc = 1;
rdp->passed_quiesc_completed = rdp->completed;
+ rcu_preempt_qs(cpu);
+ local_irq_restore(flags);
}
-void rcu_bh_qsctr_inc(int cpu)
+void rcu_bh_qs(int cpu)
{
- struct rcu_data *rdp = &per_cpu(rcu_bh_data, cpu);
+ unsigned long flags;
+ struct rcu_data *rdp;
+
+ local_irq_save(flags);
+ rdp = &per_cpu(rcu_bh_data, cpu);
rdp->passed_quiesc = 1;
rdp->passed_quiesc_completed = rdp->completed;
+ local_irq_restore(flags);
}
#ifdef CONFIG_NO_HZ
@@ -110,15 +142,16 @@ static int qhimark = 10000; /* If this many pending, ignore blimit. */
static int qlowmark = 100; /* Once only this many pending, use blimit. */
static void force_quiescent_state(struct rcu_state *rsp, int relaxed);
+static int rcu_pending(int cpu);
/*
- * Return the number of RCU batches processed thus far for debug & stats.
+ * Return the number of RCU-sched batches processed thus far for debug & stats.
*/
-long rcu_batches_completed(void)
+long rcu_batches_completed_sched(void)
{
- return rcu_state.completed;
+ return rcu_sched_state.completed;
}
-EXPORT_SYMBOL_GPL(rcu_batches_completed);
+EXPORT_SYMBOL_GPL(rcu_batches_completed_sched);
/*
* Return the number of RCU BH batches processed thus far for debug & stats.
@@ -181,6 +214,10 @@ static int rcu_implicit_offline_qs(struct rcu_data *rdp)
return 1;
}
+ /* If preemptable RCU, no point in sending reschedule IPI. */
+ if (rdp->preemptable)
+ return 0;
+
/* The CPU is online, so send it a reschedule IPI. */
if (rdp->cpu != smp_processor_id())
smp_send_reschedule(rdp->cpu);
@@ -193,7 +230,6 @@ static int rcu_implicit_offline_qs(struct rcu_data *rdp)
#endif /* #ifdef CONFIG_SMP */
#ifdef CONFIG_NO_HZ
-static DEFINE_RATELIMIT_STATE(rcu_rs, 10 * HZ, 5);
/**
* rcu_enter_nohz - inform RCU that current CPU is entering nohz
@@ -213,7 +249,7 @@ void rcu_enter_nohz(void)
rdtp = &__get_cpu_var(rcu_dynticks);
rdtp->dynticks++;
rdtp->dynticks_nesting--;
- WARN_ON_RATELIMIT(rdtp->dynticks & 0x1, &rcu_rs);
+ WARN_ON_ONCE(rdtp->dynticks & 0x1);
local_irq_restore(flags);
}
@@ -232,7 +268,7 @@ void rcu_exit_nohz(void)
rdtp = &__get_cpu_var(rcu_dynticks);
rdtp->dynticks++;
rdtp->dynticks_nesting++;
- WARN_ON_RATELIMIT(!(rdtp->dynticks & 0x1), &rcu_rs);
+ WARN_ON_ONCE(!(rdtp->dynticks & 0x1));
local_irq_restore(flags);
smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
}
@@ -251,7 +287,7 @@ void rcu_nmi_enter(void)
if (rdtp->dynticks & 0x1)
return;
rdtp->dynticks_nmi++;
- WARN_ON_RATELIMIT(!(rdtp->dynticks_nmi & 0x1), &rcu_rs);
+ WARN_ON_ONCE(!(rdtp->dynticks_nmi & 0x1));
smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
}
@@ -270,7 +306,7 @@ void rcu_nmi_exit(void)
return;
smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
rdtp->dynticks_nmi++;
- WARN_ON_RATELIMIT(rdtp->dynticks_nmi & 0x1, &rcu_rs);
+ WARN_ON_ONCE(rdtp->dynticks_nmi & 0x1);
}
/**
@@ -286,7 +322,7 @@ void rcu_irq_enter(void)
if (rdtp->dynticks_nesting++)
return;
rdtp->dynticks++;
- WARN_ON_RATELIMIT(!(rdtp->dynticks & 0x1), &rcu_rs);
+ WARN_ON_ONCE(!(rdtp->dynticks & 0x1));
smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
}
@@ -305,10 +341,10 @@ void rcu_irq_exit(void)
return;
smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
rdtp->dynticks++;
- WARN_ON_RATELIMIT(rdtp->dynticks & 0x1, &rcu_rs);
+ WARN_ON_ONCE(rdtp->dynticks & 0x1);
/* If the interrupt queued a callback, get out of dyntick mode. */
- if (__get_cpu_var(rcu_data).nxtlist ||
+ if (__get_cpu_var(rcu_sched_data).nxtlist ||
__get_cpu_var(rcu_bh_data).nxtlist)
set_need_resched();
}
@@ -461,6 +497,7 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
printk(KERN_ERR "INFO: RCU detected CPU stalls:");
for (; rnp_cur < rnp_end; rnp_cur++) {
+ rcu_print_task_stall(rnp);
if (rnp_cur->qsmask == 0)
continue;
for (cpu = 0; cpu <= rnp_cur->grphi - rnp_cur->grplo; cpu++)
@@ -469,6 +506,8 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
}
printk(" (detected by %d, t=%ld jiffies)\n",
smp_processor_id(), (long)(jiffies - rsp->gp_start));
+ trigger_all_cpu_backtrace();
+
force_quiescent_state(rsp, 0); /* Kick them all. */
}
@@ -479,12 +518,14 @@ static void print_cpu_stall(struct rcu_state *rsp)
printk(KERN_ERR "INFO: RCU detected CPU %d stall (t=%lu jiffies)\n",
smp_processor_id(), jiffies - rsp->gp_start);
- dump_stack();
+ trigger_all_cpu_backtrace();
+
spin_lock_irqsave(&rnp->lock, flags);
if ((long)(jiffies - rsp->jiffies_stall) >= 0)
rsp->jiffies_stall =
jiffies + RCU_SECONDS_TILL_STALL_RECHECK;
spin_unlock_irqrestore(&rnp->lock, flags);
+
set_need_resched(); /* kick ourselves to get things going. */
}
@@ -674,6 +715,19 @@ rcu_process_gp_end(struct rcu_state *rsp, struct rcu_data *rdp)
}
/*
+ * Clean up after the prior grace period and let rcu_start_gp() start up
+ * the next grace period if one is needed. Note that the caller must
+ * hold rnp->lock, as required by rcu_start_gp(), which will release it.
+ */
+static void cpu_quiet_msk_finish(struct rcu_state *rsp, unsigned long flags)
+ __releases(rnp->lock)
+{
+ rsp->completed = rsp->gpnum;
+ rcu_process_gp_end(rsp, rsp->rda[smp_processor_id()]);
+ rcu_start_gp(rsp, flags); /* releases root node's rnp->lock. */
+}
+
+/*
* Similar to cpu_quiet(), for which it is a helper function. Allows
* a group of CPUs to be quieted at one go, though all the CPUs in the
* group must be represented by the same leaf rcu_node structure.
@@ -694,7 +748,7 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp,
return;
}
rnp->qsmask &= ~mask;
- if (rnp->qsmask != 0) {
+ if (rnp->qsmask != 0 || rcu_preempted_readers(rnp)) {
/* Other bits still set at this level, so done. */
spin_unlock_irqrestore(&rnp->lock, flags);
@@ -714,14 +768,10 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp,
/*
* Get here if we are the last CPU to pass through a quiescent
- * state for this grace period. Clean up and let rcu_start_gp()
- * start up the next grace period if one is needed. Note that
- * we still hold rnp->lock, as required by rcu_start_gp(), which
- * will release it.
+ * state for this grace period. Invoke cpu_quiet_msk_finish()
+ * to clean up and start the next grace period if one is needed.
*/
- rsp->completed = rsp->gpnum;
- rcu_process_gp_end(rsp, rsp->rda[smp_processor_id()]);
- rcu_start_gp(rsp, flags); /* releases rnp->lock. */
+ cpu_quiet_msk_finish(rsp, flags); /* releases rnp->lock. */
}
/*
@@ -828,11 +878,12 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
spin_lock(&rnp->lock); /* irqs already disabled. */
rnp->qsmaskinit &= ~mask;
if (rnp->qsmaskinit != 0) {
- spin_unlock(&rnp->lock); /* irqs already disabled. */
+ spin_unlock(&rnp->lock); /* irqs remain disabled. */
break;
}
+ rcu_preempt_offline_tasks(rsp, rnp);
mask = rnp->grpmask;
- spin_unlock(&rnp->lock); /* irqs already disabled. */
+ spin_unlock(&rnp->lock); /* irqs remain disabled. */
rnp = rnp->parent;
} while (rnp != NULL);
lastcomp = rsp->completed;
@@ -845,7 +896,7 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
/*
* Move callbacks from the outgoing CPU to the running CPU.
* Note that the outgoing CPU is now quiscent, so it is now
- * (uncharacteristically) safe to access it rcu_data structure.
+ * (uncharacteristically) safe to access its rcu_data structure.
* Note also that we must carefully retain the order of the
* outgoing CPU's callbacks in order for rcu_barrier() to work
* correctly. Finally, note that we start all the callbacks
@@ -876,8 +927,9 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
*/
static void rcu_offline_cpu(int cpu)
{
- __rcu_offline_cpu(cpu, &rcu_state);
+ __rcu_offline_cpu(cpu, &rcu_sched_state);
__rcu_offline_cpu(cpu, &rcu_bh_state);
+ rcu_preempt_offline_cpu(cpu);
}
#else /* #ifdef CONFIG_HOTPLUG_CPU */
@@ -963,6 +1015,8 @@ static void rcu_do_batch(struct rcu_data *rdp)
*/
void rcu_check_callbacks(int cpu, int user)
{
+ if (!rcu_pending(cpu))
+ return; /* if nothing for RCU to do. */
if (user ||
(idle_cpu(cpu) && rcu_scheduler_active &&
!in_softirq() && hardirq_count() <= (1 << HARDIRQ_SHIFT))) {
@@ -971,17 +1025,16 @@ void rcu_check_callbacks(int cpu, int user)
* Get here if this CPU took its interrupt from user
* mode or from the idle loop, and if this is not a
* nested interrupt. In this case, the CPU is in
- * a quiescent state, so count it.
+ * a quiescent state, so note it.
*
* No memory barrier is required here because both
- * rcu_qsctr_inc() and rcu_bh_qsctr_inc() reference
- * only CPU-local variables that other CPUs neither
- * access nor modify, at least not while the corresponding
- * CPU is online.
+ * rcu_sched_qs() and rcu_bh_qs() reference only CPU-local
+ * variables that other CPUs neither access nor modify,
+ * at least not while the corresponding CPU is online.
*/
- rcu_qsctr_inc(cpu);
- rcu_bh_qsctr_inc(cpu);
+ rcu_sched_qs(cpu);
+ rcu_bh_qs(cpu);
} else if (!in_softirq()) {
@@ -989,11 +1042,12 @@ void rcu_check_callbacks(int cpu, int user)
* Get here if this CPU did not take its interrupt from
* softirq, in other words, if it is not interrupting
* a rcu_bh read-side critical section. This is an _bh
- * critical section, so count it.
+ * critical section, so note it.
*/
- rcu_bh_qsctr_inc(cpu);
+ rcu_bh_qs(cpu);
}
+ rcu_preempt_check_callbacks(cpu);
raise_softirq(RCU_SOFTIRQ);
}
@@ -1132,6 +1186,8 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp)
{
unsigned long flags;
+ WARN_ON_ONCE(rdp->beenonline == 0);
+
/*
* If an RCU GP has gone long enough, go check for dyntick
* idle CPUs and, if needed, send resched IPIs.
@@ -1170,8 +1226,10 @@ static void rcu_process_callbacks(struct softirq_action *unused)
*/
smp_mb(); /* See above block comment. */
- __rcu_process_callbacks(&rcu_state, &__get_cpu_var(rcu_data));
+ __rcu_process_callbacks(&rcu_sched_state,
+ &__get_cpu_var(rcu_sched_data));
__rcu_process_callbacks(&rcu_bh_state, &__get_cpu_var(rcu_bh_data));
+ rcu_preempt_process_callbacks();
/*
* Memory references from any later RCU read-side critical sections
@@ -1227,13 +1285,13 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu),
}
/*
- * Queue an RCU callback for invocation after a grace period.
+ * Queue an RCU-sched callback for invocation after a grace period.
*/
-void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
+void call_rcu_sched(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
{
- __call_rcu(head, func, &rcu_state);
+ __call_rcu(head, func, &rcu_sched_state);
}
-EXPORT_SYMBOL_GPL(call_rcu);
+EXPORT_SYMBOL_GPL(call_rcu_sched);
/*
* Queue an RCU for invocation after a quicker grace period.
@@ -1305,10 +1363,11 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)
* by the current CPU, returning 1 if so. This function is part of the
* RCU implementation; it is -not- an exported member of the RCU API.
*/
-int rcu_pending(int cpu)
+static int rcu_pending(int cpu)
{
- return __rcu_pending(&rcu_state, &per_cpu(rcu_data, cpu)) ||
- __rcu_pending(&rcu_bh_state, &per_cpu(rcu_bh_data, cpu));
+ return __rcu_pending(&rcu_sched_state, &per_cpu(rcu_sched_data, cpu)) ||
+ __rcu_pending(&rcu_bh_state, &per_cpu(rcu_bh_data, cpu)) ||
+ rcu_preempt_pending(cpu);
}
/*
@@ -1320,27 +1379,46 @@ int rcu_pending(int cpu)
int rcu_needs_cpu(int cpu)
{
/* RCU callbacks either ready or pending? */
- return per_cpu(rcu_data, cpu).nxtlist ||
- per_cpu(rcu_bh_data, cpu).nxtlist;
+ return per_cpu(rcu_sched_data, cpu).nxtlist ||
+ per_cpu(rcu_bh_data, cpu).nxtlist ||
+ rcu_preempt_needs_cpu(cpu);
}
/*
- * Initialize a CPU's per-CPU RCU data. We take this "scorched earth"
- * approach so that we don't have to worry about how long the CPU has
- * been gone, or whether it ever was online previously. We do trust the
- * ->mynode field, as it is constant for a given struct rcu_data and
- * initialized during early boot.
- *
- * Note that only one online or offline event can be happening at a given
- * time. Note also that we can accept some slop in the rsp->completed
- * access due to the fact that this CPU cannot possibly have any RCU
- * callbacks in flight yet.
+ * Do boot-time initialization of a CPU's per-CPU RCU data.
*/
-static void __cpuinit
-rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
+static void __init
+rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
{
unsigned long flags;
int i;
+ struct rcu_data *rdp = rsp->rda[cpu];
+ struct rcu_node *rnp = rcu_get_root(rsp);
+
+ /* Set up local state, ensuring consistent view of global state. */
+ spin_lock_irqsave(&rnp->lock, flags);
+ rdp->grpmask = 1UL << (cpu - rdp->mynode->grplo);
+ rdp->nxtlist = NULL;
+ for (i = 0; i < RCU_NEXT_SIZE; i++)
+ rdp->nxttail[i] = &rdp->nxtlist;
+ rdp->qlen = 0;
+#ifdef CONFIG_NO_HZ
+ rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
+#endif /* #ifdef CONFIG_NO_HZ */
+ rdp->cpu = cpu;
+ spin_unlock_irqrestore(&rnp->lock, flags);
+}
+
+/*
+ * Initialize a CPU's per-CPU RCU data. Note that only one online or
+ * offline event can be happening at a given time. Note also that we
+ * can accept some slop in the rsp->completed access due to the fact
+ * that this CPU cannot possibly have any RCU callbacks in flight yet.
+ */
+static void __cpuinit
+rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable)
+{
+ unsigned long flags;
long lastcomp;
unsigned long mask;
struct rcu_data *rdp = rsp->rda[cpu];
@@ -1354,17 +1432,9 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
rdp->passed_quiesc = 0; /* We could be racing with new GP, */
rdp->qs_pending = 1; /* so set up to respond to current GP. */
rdp->beenonline = 1; /* We have now been online. */
+ rdp->preemptable = preemptable;
rdp->passed_quiesc_completed = lastcomp - 1;
- rdp->grpmask = 1UL << (cpu - rdp->mynode->grplo);
- rdp->nxtlist = NULL;
- for (i = 0; i < RCU_NEXT_SIZE; i++)
- rdp->nxttail[i] = &rdp->nxtlist;
- rdp->qlen = 0;
rdp->blimit = blimit;
-#ifdef CONFIG_NO_HZ
- rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
-#endif /* #ifdef CONFIG_NO_HZ */
- rdp->cpu = cpu;
spin_unlock(&rnp->lock); /* irqs remain disabled. */
/*
@@ -1405,16 +1475,16 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
static void __cpuinit rcu_online_cpu(int cpu)
{
- rcu_init_percpu_data(cpu, &rcu_state);
- rcu_init_percpu_data(cpu, &rcu_bh_state);
- open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
+ rcu_init_percpu_data(cpu, &rcu_sched_state, 0);
+ rcu_init_percpu_data(cpu, &rcu_bh_state, 0);
+ rcu_preempt_init_percpu_data(cpu);
}
/*
- * Handle CPU online/offline notifcation events.
+ * Handle CPU online/offline notification events.
*/
-static int __cpuinit rcu_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
+int __cpuinit rcu_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
{
long cpu = (long)hcpu;
@@ -1486,6 +1556,7 @@ static void __init rcu_init_one(struct rcu_state *rsp)
rnp = rsp->level[i];
for (j = 0; j < rsp->levelcnt[i]; j++, rnp++) {
spin_lock_init(&rnp->lock);
+ rnp->gpnum = 0;
rnp->qsmask = 0;
rnp->qsmaskinit = 0;
rnp->grplo = j * cpustride;
@@ -1503,16 +1574,20 @@ static void __init rcu_init_one(struct rcu_state *rsp)
j / rsp->levelspread[i - 1];
}
rnp->level = i;
+ INIT_LIST_HEAD(&rnp->blocked_tasks[0]);
+ INIT_LIST_HEAD(&rnp->blocked_tasks[1]);
}
}
}
/*
- * Helper macro for __rcu_init(). To be used nowhere else!
- * Assigns leaf node pointers into each CPU's rcu_data structure.
+ * Helper macro for __rcu_init() and __rcu_init_preempt(). To be used
+ * nowhere else! Assigns leaf node pointers into each CPU's rcu_data
+ * structure.
*/
-#define RCU_DATA_PTR_INIT(rsp, rcu_data) \
+#define RCU_INIT_FLAVOR(rsp, rcu_data) \
do { \
+ rcu_init_one(rsp); \
rnp = (rsp)->level[NUM_RCU_LVLS - 1]; \
j = 0; \
for_each_possible_cpu(i) { \
@@ -1520,32 +1595,43 @@ do { \
j++; \
per_cpu(rcu_data, i).mynode = &rnp[j]; \
(rsp)->rda[i] = &per_cpu(rcu_data, i); \
+ rcu_boot_init_percpu_data(i, rsp); \
} \
} while (0)
-static struct notifier_block __cpuinitdata rcu_nb = {
- .notifier_call = rcu_cpu_notify,
-};
+#ifdef CONFIG_TREE_PREEMPT_RCU
+
+void __init __rcu_init_preempt(void)
+{
+ int i; /* All used by RCU_INIT_FLAVOR(). */
+ int j;
+ struct rcu_node *rnp;
+
+ RCU_INIT_FLAVOR(&rcu_preempt_state, rcu_preempt_data);
+}
+
+#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */
+
+void __init __rcu_init_preempt(void)
+{
+}
+
+#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
void __init __rcu_init(void)
{
- int i; /* All used by RCU_DATA_PTR_INIT(). */
+ int i; /* All used by RCU_INIT_FLAVOR(). */
int j;
struct rcu_node *rnp;
- printk(KERN_INFO "Hierarchical RCU implementation.\n");
+ rcu_bootup_announce();
#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
printk(KERN_INFO "RCU-based detection of stalled CPUs is enabled.\n");
#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
- rcu_init_one(&rcu_state);
- RCU_DATA_PTR_INIT(&rcu_state, rcu_data);
- rcu_init_one(&rcu_bh_state);
- RCU_DATA_PTR_INIT(&rcu_bh_state, rcu_bh_data);
-
- for_each_online_cpu(i)
- rcu_cpu_notify(&rcu_nb, CPU_UP_PREPARE, (void *)(long)i);
- /* Register notifier for non-boot CPUs */
- register_cpu_notifier(&rcu_nb);
+ RCU_INIT_FLAVOR(&rcu_sched_state, rcu_sched_data);
+ RCU_INIT_FLAVOR(&rcu_bh_state, rcu_bh_data);
+ __rcu_init_preempt();
+ open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
}
module_param(blimit, int, 0);
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index 5e872bbf07f5..bf8a6f9f134d 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -1,10 +1,259 @@
+/*
+ * Read-Copy Update mechanism for mutual exclusion (tree-based version)
+ * Internal non-public definitions.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright IBM Corporation, 2008
+ *
+ * Author: Ingo Molnar <mingo@elte.hu>
+ * Paul E. McKenney <paulmck@linux.vnet.ibm.com>
+ */
+
+#include <linux/cache.h>
+#include <linux/spinlock.h>
+#include <linux/threads.h>
+#include <linux/cpumask.h>
+#include <linux/seqlock.h>
+
+/*
+ * Define shape of hierarchy based on NR_CPUS and CONFIG_RCU_FANOUT.
+ * In theory, it should be possible to add more levels straightforwardly.
+ * In practice, this has not been tested, so there is probably some
+ * bug somewhere.
+ */
+#define MAX_RCU_LVLS 3
+#define RCU_FANOUT (CONFIG_RCU_FANOUT)
+#define RCU_FANOUT_SQ (RCU_FANOUT * RCU_FANOUT)
+#define RCU_FANOUT_CUBE (RCU_FANOUT_SQ * RCU_FANOUT)
+
+#if NR_CPUS <= RCU_FANOUT
+# define NUM_RCU_LVLS 1
+# define NUM_RCU_LVL_0 1
+# define NUM_RCU_LVL_1 (NR_CPUS)
+# define NUM_RCU_LVL_2 0
+# define NUM_RCU_LVL_3 0
+#elif NR_CPUS <= RCU_FANOUT_SQ
+# define NUM_RCU_LVLS 2
+# define NUM_RCU_LVL_0 1
+# define NUM_RCU_LVL_1 (((NR_CPUS) + RCU_FANOUT - 1) / RCU_FANOUT)
+# define NUM_RCU_LVL_2 (NR_CPUS)
+# define NUM_RCU_LVL_3 0
+#elif NR_CPUS <= RCU_FANOUT_CUBE
+# define NUM_RCU_LVLS 3
+# define NUM_RCU_LVL_0 1
+# define NUM_RCU_LVL_1 (((NR_CPUS) + RCU_FANOUT_SQ - 1) / RCU_FANOUT_SQ)
+# define NUM_RCU_LVL_2 (((NR_CPUS) + (RCU_FANOUT) - 1) / (RCU_FANOUT))
+# define NUM_RCU_LVL_3 NR_CPUS
+#else
+# error "CONFIG_RCU_FANOUT insufficient for NR_CPUS"
+#endif /* #if (NR_CPUS) <= RCU_FANOUT */
+
+#define RCU_SUM (NUM_RCU_LVL_0 + NUM_RCU_LVL_1 + NUM_RCU_LVL_2 + NUM_RCU_LVL_3)
+#define NUM_RCU_NODES (RCU_SUM - NR_CPUS)
+
+/*
+ * Dynticks per-CPU state.
+ */
+struct rcu_dynticks {
+ int dynticks_nesting; /* Track nesting level, sort of. */
+ int dynticks; /* Even value for dynticks-idle, else odd. */
+ int dynticks_nmi; /* Even value for either dynticks-idle or */
+ /* not in nmi handler, else odd. So this */
+ /* remains even for nmi from irq handler. */
+};
+
+/*
+ * Definition for node within the RCU grace-period-detection hierarchy.
+ */
+struct rcu_node {
+ spinlock_t lock;
+ long gpnum; /* Current grace period for this node. */
+ /* This will either be equal to or one */
+ /* behind the root rcu_node's gpnum. */
+ unsigned long qsmask; /* CPUs or groups that need to switch in */
+ /* order for current grace period to proceed.*/
+ unsigned long qsmaskinit;
+ /* Per-GP initialization for qsmask. */
+ unsigned long grpmask; /* Mask to apply to parent qsmask. */
+ int grplo; /* lowest-numbered CPU or group here. */
+ int grphi; /* highest-numbered CPU or group here. */
+ u8 grpnum; /* CPU/group number for next level up. */
+ u8 level; /* root is at level 0. */
+ struct rcu_node *parent;
+ struct list_head blocked_tasks[2];
+ /* Tasks blocked in RCU read-side critsect. */
+} ____cacheline_internodealigned_in_smp;
+
+/* Index values for nxttail array in struct rcu_data. */
+#define RCU_DONE_TAIL 0 /* Also RCU_WAIT head. */
+#define RCU_WAIT_TAIL 1 /* Also RCU_NEXT_READY head. */
+#define RCU_NEXT_READY_TAIL 2 /* Also RCU_NEXT head. */
+#define RCU_NEXT_TAIL 3
+#define RCU_NEXT_SIZE 4
+
+/* Per-CPU data for read-copy update. */
+struct rcu_data {
+ /* 1) quiescent-state and grace-period handling : */
+ long completed; /* Track rsp->completed gp number */
+ /* in order to detect GP end. */
+ long gpnum; /* Highest gp number that this CPU */
+ /* is aware of having started. */
+ long passed_quiesc_completed;
+ /* Value of completed at time of qs. */
+ bool passed_quiesc; /* User-mode/idle loop etc. */
+ bool qs_pending; /* Core waits for quiesc state. */
+ bool beenonline; /* CPU online at least once. */
+ bool preemptable; /* Preemptable RCU? */
+ struct rcu_node *mynode; /* This CPU's leaf of hierarchy */
+ unsigned long grpmask; /* Mask to apply to leaf qsmask. */
+
+ /* 2) batch handling */
+ /*
+ * If nxtlist is not NULL, it is partitioned as follows.
+ * Any of the partitions might be empty, in which case the
+ * pointer to that partition will be equal to the pointer for
+ * the following partition. When the list is empty, all of
+ * the nxttail elements point to nxtlist, which is NULL.
+ *
+ * [*nxttail[RCU_NEXT_READY_TAIL], NULL = *nxttail[RCU_NEXT_TAIL]):
+ * Entries that might have arrived after current GP ended
+ * [*nxttail[RCU_WAIT_TAIL], *nxttail[RCU_NEXT_READY_TAIL]):
+ * Entries known to have arrived before current GP ended
+ * [*nxttail[RCU_DONE_TAIL], *nxttail[RCU_WAIT_TAIL]):
+ * Entries that batch # <= ->completed - 1: waiting for current GP
+ * [nxtlist, *nxttail[RCU_DONE_TAIL]):
+ * Entries that batch # <= ->completed
+ * The grace period for these entries has completed, and
+ * the other grace-period-completed entries may be moved
+ * here temporarily in rcu_process_callbacks().
+ */
+ struct rcu_head *nxtlist;
+ struct rcu_head **nxttail[RCU_NEXT_SIZE];
+ long qlen; /* # of queued callbacks */
+ long blimit; /* Upper limit on a processed batch */
+
+#ifdef CONFIG_NO_HZ
+ /* 3) dynticks interface. */
+ struct rcu_dynticks *dynticks; /* Shared per-CPU dynticks state. */
+ int dynticks_snap; /* Per-GP tracking for dynticks. */
+ int dynticks_nmi_snap; /* Per-GP tracking for dynticks_nmi. */
+#endif /* #ifdef CONFIG_NO_HZ */
+
+ /* 4) reasons this CPU needed to be kicked by force_quiescent_state */
+#ifdef CONFIG_NO_HZ
+ unsigned long dynticks_fqs; /* Kicked due to dynticks idle. */
+#endif /* #ifdef CONFIG_NO_HZ */
+ unsigned long offline_fqs; /* Kicked due to being offline. */
+ unsigned long resched_ipi; /* Sent a resched IPI. */
+
+ /* 5) __rcu_pending() statistics. */
+ long n_rcu_pending; /* rcu_pending() calls since boot. */
+ long n_rp_qs_pending;
+ long n_rp_cb_ready;
+ long n_rp_cpu_needs_gp;
+ long n_rp_gp_completed;
+ long n_rp_gp_started;
+ long n_rp_need_fqs;
+ long n_rp_need_nothing;
+
+ int cpu;
+};
+
+/* Values for signaled field in struct rcu_state. */
+#define RCU_GP_INIT 0 /* Grace period being initialized. */
+#define RCU_SAVE_DYNTICK 1 /* Need to scan dyntick state. */
+#define RCU_FORCE_QS 2 /* Need to force quiescent state. */
+#ifdef CONFIG_NO_HZ
+#define RCU_SIGNAL_INIT RCU_SAVE_DYNTICK
+#else /* #ifdef CONFIG_NO_HZ */
+#define RCU_SIGNAL_INIT RCU_FORCE_QS
+#endif /* #else #ifdef CONFIG_NO_HZ */
+
+#define RCU_JIFFIES_TILL_FORCE_QS 3 /* for rsp->jiffies_force_qs */
+#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
+#define RCU_SECONDS_TILL_STALL_CHECK (10 * HZ) /* for rsp->jiffies_stall */
+#define RCU_SECONDS_TILL_STALL_RECHECK (30 * HZ) /* for rsp->jiffies_stall */
+#define RCU_STALL_RAT_DELAY 2 /* Allow other CPUs time */
+ /* to take at least one */
+ /* scheduling clock irq */
+ /* before ratting on them. */
+
+#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+
+/*
+ * RCU global state, including node hierarchy. This hierarchy is
+ * represented in "heap" form in a dense array. The root (first level)
+ * of the hierarchy is in ->node[0] (referenced by ->level[0]), the second
+ * level in ->node[1] through ->node[m] (->node[1] referenced by ->level[1]),
+ * and the third level in ->node[m+1] and following (->node[m+1] referenced
+ * by ->level[2]). The number of levels is determined by the number of
+ * CPUs and by CONFIG_RCU_FANOUT. Small systems will have a "hierarchy"
+ * consisting of a single rcu_node.
+ */
+struct rcu_state {
+ struct rcu_node node[NUM_RCU_NODES]; /* Hierarchy. */
+ struct rcu_node *level[NUM_RCU_LVLS]; /* Hierarchy levels. */
+ u32 levelcnt[MAX_RCU_LVLS + 1]; /* # nodes in each level. */
+ u8 levelspread[NUM_RCU_LVLS]; /* kids/node in each level. */
+ struct rcu_data *rda[NR_CPUS]; /* array of rdp pointers. */
+
+ /* The following fields are guarded by the root rcu_node's lock. */
+
+ u8 signaled ____cacheline_internodealigned_in_smp;
+ /* Force QS state. */
+ long gpnum; /* Current gp number. */
+ long completed; /* # of last completed gp. */
+ spinlock_t onofflock; /* exclude on/offline and */
+ /* starting new GP. */
+ spinlock_t fqslock; /* Only one task forcing */
+ /* quiescent states. */
+ unsigned long jiffies_force_qs; /* Time at which to invoke */
+ /* force_quiescent_state(). */
+ unsigned long n_force_qs; /* Number of calls to */
+ /* force_quiescent_state(). */
+ unsigned long n_force_qs_lh; /* ~Number of calls leaving */
+ /* due to lock unavailable. */
+ unsigned long n_force_qs_ngp; /* Number of calls leaving */
+ /* due to no GP active. */
+#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
+ unsigned long gp_start; /* Time at which GP started, */
+ /* but in jiffies. */
+ unsigned long jiffies_stall; /* Time at which to check */
+ /* for CPU stalls. */
+#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+#ifdef CONFIG_NO_HZ
+ long dynticks_completed; /* Value of completed @ snap. */
+#endif /* #ifdef CONFIG_NO_HZ */
+};
+
+#ifdef RCU_TREE_NONCORE
/*
* RCU implementation internal declarations:
*/
-extern struct rcu_state rcu_state;
-DECLARE_PER_CPU(struct rcu_data, rcu_data);
+extern struct rcu_state rcu_sched_state;
+DECLARE_PER_CPU(struct rcu_data, rcu_sched_data);
extern struct rcu_state rcu_bh_state;
DECLARE_PER_CPU(struct rcu_data, rcu_bh_data);
+#ifdef CONFIG_TREE_PREEMPT_RCU
+extern struct rcu_state rcu_preempt_state;
+DECLARE_PER_CPU(struct rcu_data, rcu_preempt_data);
+#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
+
+#endif /* #ifdef RCU_TREE_NONCORE */
+
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
new file mode 100644
index 000000000000..47789369ea59
--- /dev/null
+++ b/kernel/rcutree_plugin.h
@@ -0,0 +1,532 @@
+/*
+ * Read-Copy Update mechanism for mutual exclusion (tree-based version)
+ * Internal non-public definitions that provide either classic
+ * or preemptable semantics.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright Red Hat, 2009
+ * Copyright IBM Corporation, 2009
+ *
+ * Author: Ingo Molnar <mingo@elte.hu>
+ * Paul E. McKenney <paulmck@linux.vnet.ibm.com>
+ */
+
+
+#ifdef CONFIG_TREE_PREEMPT_RCU
+
+struct rcu_state rcu_preempt_state = RCU_STATE_INITIALIZER(rcu_preempt_state);
+DEFINE_PER_CPU(struct rcu_data, rcu_preempt_data);
+
+/*
+ * Tell them what RCU they are running.
+ */
+static inline void rcu_bootup_announce(void)
+{
+ printk(KERN_INFO
+ "Experimental preemptable hierarchical RCU implementation.\n");
+}
+
+/*
+ * Return the number of RCU-preempt batches processed thus far
+ * for debug and statistics.
+ */
+long rcu_batches_completed_preempt(void)
+{
+ return rcu_preempt_state.completed;
+}
+EXPORT_SYMBOL_GPL(rcu_batches_completed_preempt);
+
+/*
+ * Return the number of RCU batches processed thus far for debug & stats.
+ */
+long rcu_batches_completed(void)
+{
+ return rcu_batches_completed_preempt();
+}
+EXPORT_SYMBOL_GPL(rcu_batches_completed);
+
+/*
+ * Record a preemptable-RCU quiescent state for the specified CPU. Note
+ * that this just means that the task currently running on the CPU is
+ * not in a quiescent state. There might be any number of tasks blocked
+ * while in an RCU read-side critical section.
+ */
+static void rcu_preempt_qs_record(int cpu)
+{
+ struct rcu_data *rdp = &per_cpu(rcu_preempt_data, cpu);
+ rdp->passed_quiesc = 1;
+ rdp->passed_quiesc_completed = rdp->completed;
+}
+
+/*
+ * We have entered the scheduler or are between softirqs in ksoftirqd.
+ * If we are in an RCU read-side critical section, we need to reflect
+ * that in the state of the rcu_node structure corresponding to this CPU.
+ * Caller must disable hardirqs.
+ */
+static void rcu_preempt_qs(int cpu)
+{
+ struct task_struct *t = current;
+ int phase;
+ struct rcu_data *rdp;
+ struct rcu_node *rnp;
+
+ if (t->rcu_read_lock_nesting &&
+ (t->rcu_read_unlock_special & RCU_READ_UNLOCK_BLOCKED) == 0) {
+
+ /* Possibly blocking in an RCU read-side critical section. */
+ rdp = rcu_preempt_state.rda[cpu];
+ rnp = rdp->mynode;
+ spin_lock(&rnp->lock);
+ t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BLOCKED;
+ t->rcu_blocked_node = rnp;
+
+ /*
+ * If this CPU has already checked in, then this task
+ * will hold up the next grace period rather than the
+ * current grace period. Queue the task accordingly.
+ * If the task is queued for the current grace period
+ * (i.e., this CPU has not yet passed through a quiescent
+ * state for the current grace period), then as long
+ * as that task remains queued, the current grace period
+ * cannot end.
+ */
+ phase = !(rnp->qsmask & rdp->grpmask) ^ (rnp->gpnum & 0x1);
+ list_add(&t->rcu_node_entry, &rnp->blocked_tasks[phase]);
+ smp_mb(); /* Ensure later ctxt swtch seen after above. */
+ spin_unlock(&rnp->lock);
+ }
+
+ /*
+ * Either we were not in an RCU read-side critical section to
+ * begin with, or we have now recorded that critical section
+ * globally. Either way, we can now note a quiescent state
+ * for this CPU. Again, if we were in an RCU read-side critical
+ * section, and if that critical section was blocking the current
+ * grace period, then the fact that the task has been enqueued
+ * means that we continue to block the current grace period.
+ */
+ rcu_preempt_qs_record(cpu);
+ t->rcu_read_unlock_special &= ~(RCU_READ_UNLOCK_NEED_QS |
+ RCU_READ_UNLOCK_GOT_QS);
+}
+
+/*
+ * Tree-preemptable RCU implementation for rcu_read_lock().
+ * Just increment ->rcu_read_lock_nesting, shared state will be updated
+ * if we block.
+ */
+void __rcu_read_lock(void)
+{
+ ACCESS_ONCE(current->rcu_read_lock_nesting)++;
+ barrier(); /* needed if we ever invoke rcu_read_lock in rcutree.c */
+}
+EXPORT_SYMBOL_GPL(__rcu_read_lock);
+
+static void rcu_read_unlock_special(struct task_struct *t)
+{
+ int empty;
+ unsigned long flags;
+ unsigned long mask;
+ struct rcu_node *rnp;
+ int special;
+
+ /* NMI handlers cannot block and cannot safely manipulate state. */
+ if (in_nmi())
+ return;
+
+ local_irq_save(flags);
+
+ /*
+ * If RCU core is waiting for this CPU to exit critical section,
+ * let it know that we have done so.
+ */
+ special = t->rcu_read_unlock_special;
+ if (special & RCU_READ_UNLOCK_NEED_QS) {
+ t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS;
+ t->rcu_read_unlock_special |= RCU_READ_UNLOCK_GOT_QS;
+ }
+
+ /* Hardware IRQ handlers cannot block. */
+ if (in_irq()) {
+ local_irq_restore(flags);
+ return;
+ }
+
+ /* Clean up if blocked during RCU read-side critical section. */
+ if (special & RCU_READ_UNLOCK_BLOCKED) {
+ t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_BLOCKED;
+
+ /*
+ * Remove this task from the list it blocked on. The
+ * task can migrate while we acquire the lock, but at
+ * most one time. So at most two passes through loop.
+ */
+ for (;;) {
+ rnp = t->rcu_blocked_node;
+ spin_lock(&rnp->lock);
+ if (rnp == t->rcu_blocked_node)
+ break;
+ spin_unlock(&rnp->lock);
+ }
+ empty = list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
+ list_del_init(&t->rcu_node_entry);
+ t->rcu_blocked_node = NULL;
+
+ /*
+ * If this was the last task on the current list, and if
+ * we aren't waiting on any CPUs, report the quiescent state.
+ * Note that both cpu_quiet_msk_finish() and cpu_quiet_msk()
+ * drop rnp->lock and restore irq.
+ */
+ if (!empty && rnp->qsmask == 0 &&
+ list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1])) {
+ t->rcu_read_unlock_special &=
+ ~(RCU_READ_UNLOCK_NEED_QS |
+ RCU_READ_UNLOCK_GOT_QS);
+ if (rnp->parent == NULL) {
+ /* Only one rcu_node in the tree. */
+ cpu_quiet_msk_finish(&rcu_preempt_state, flags);
+ return;
+ }
+ /* Report up the rest of the hierarchy. */
+ mask = rnp->grpmask;
+ spin_unlock_irqrestore(&rnp->lock, flags);
+ rnp = rnp->parent;
+ spin_lock_irqsave(&rnp->lock, flags);
+ cpu_quiet_msk(mask, &rcu_preempt_state, rnp, flags);
+ return;
+ }
+ spin_unlock(&rnp->lock);
+ }
+ local_irq_restore(flags);
+}
+
+/*
+ * Tree-preemptable RCU implementation for rcu_read_unlock().
+ * Decrement ->rcu_read_lock_nesting. If the result is zero (outermost
+ * rcu_read_unlock()) and ->rcu_read_unlock_special is non-zero, then
+ * invoke rcu_read_unlock_special() to clean up after a context switch
+ * in an RCU read-side critical section and other special cases.
+ */
+void __rcu_read_unlock(void)
+{
+ struct task_struct *t = current;
+
+ barrier(); /* needed if we ever invoke rcu_read_unlock in rcutree.c */
+ if (--ACCESS_ONCE(t->rcu_read_lock_nesting) == 0 &&
+ unlikely(ACCESS_ONCE(t->rcu_read_unlock_special)))
+ rcu_read_unlock_special(t);
+}
+EXPORT_SYMBOL_GPL(__rcu_read_unlock);
+
+#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
+
+/*
+ * Scan the current list of tasks blocked within RCU read-side critical
+ * sections, printing out the tid of each.
+ */
+static void rcu_print_task_stall(struct rcu_node *rnp)
+{
+ unsigned long flags;
+ struct list_head *lp;
+ int phase = rnp->gpnum & 0x1;
+ struct task_struct *t;
+
+ if (!list_empty(&rnp->blocked_tasks[phase])) {
+ spin_lock_irqsave(&rnp->lock, flags);
+ phase = rnp->gpnum & 0x1; /* re-read under lock. */
+ lp = &rnp->blocked_tasks[phase];
+ list_for_each_entry(t, lp, rcu_node_entry)
+ printk(" P%d", t->pid);
+ spin_unlock_irqrestore(&rnp->lock, flags);
+ }
+}
+
+#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+
+/*
+ * Check for preempted RCU readers for the specified rcu_node structure.
+ * If the caller needs a reliable answer, it must hold the rcu_node's
+ * >lock.
+ */
+static int rcu_preempted_readers(struct rcu_node *rnp)
+{
+ return !list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+/*
+ * Handle tasklist migration for case in which all CPUs covered by the
+ * specified rcu_node have gone offline. Move them up to the root
+ * rcu_node. The reason for not just moving them to the immediate
+ * parent is to remove the need for rcu_read_unlock_special() to
+ * make more than two attempts to acquire the target rcu_node's lock.
+ *
+ * The caller must hold rnp->lock with irqs disabled.
+ */
+static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
+ struct rcu_node *rnp)
+{
+ int i;
+ struct list_head *lp;
+ struct list_head *lp_root;
+ struct rcu_node *rnp_root = rcu_get_root(rsp);
+ struct task_struct *tp;
+
+ if (rnp == rnp_root) {
+ WARN_ONCE(1, "Last CPU thought to be offlined?");
+ return; /* Shouldn't happen: at least one CPU online. */
+ }
+
+ /*
+ * Move tasks up to root rcu_node. Rely on the fact that the
+ * root rcu_node can be at most one ahead of the rest of the
+ * rcu_nodes in terms of gp_num value. This fact allows us to
+ * move the blocked_tasks[] array directly, element by element.
+ */
+ for (i = 0; i < 2; i++) {
+ lp = &rnp->blocked_tasks[i];
+ lp_root = &rnp_root->blocked_tasks[i];
+ while (!list_empty(lp)) {
+ tp = list_entry(lp->next, typeof(*tp), rcu_node_entry);
+ spin_lock(&rnp_root->lock); /* irqs already disabled */
+ list_del(&tp->rcu_node_entry);
+ tp->rcu_blocked_node = rnp_root;
+ list_add(&tp->rcu_node_entry, lp_root);
+ spin_unlock(&rnp_root->lock); /* irqs remain disabled */
+ }
+ }
+}
+
+/*
+ * Do CPU-offline processing for preemptable RCU.
+ */
+static void rcu_preempt_offline_cpu(int cpu)
+{
+ __rcu_offline_cpu(cpu, &rcu_preempt_state);
+}
+
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+
+/*
+ * Check for a quiescent state from the current CPU. When a task blocks,
+ * the task is recorded in the corresponding CPU's rcu_node structure,
+ * which is checked elsewhere.
+ *
+ * Caller must disable hard irqs.
+ */
+static void rcu_preempt_check_callbacks(int cpu)
+{
+ struct task_struct *t = current;
+
+ if (t->rcu_read_lock_nesting == 0) {
+ t->rcu_read_unlock_special &=
+ ~(RCU_READ_UNLOCK_NEED_QS | RCU_READ_UNLOCK_GOT_QS);
+ rcu_preempt_qs_record(cpu);
+ return;
+ }
+ if (per_cpu(rcu_preempt_data, cpu).qs_pending) {
+ if (t->rcu_read_unlock_special & RCU_READ_UNLOCK_GOT_QS) {
+ rcu_preempt_qs_record(cpu);
+ t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_GOT_QS;
+ } else if (!(t->rcu_read_unlock_special &
+ RCU_READ_UNLOCK_NEED_QS)) {
+ t->rcu_read_unlock_special |= RCU_READ_UNLOCK_NEED_QS;
+ }
+ }
+}
+
+/*
+ * Process callbacks for preemptable RCU.
+ */
+static void rcu_preempt_process_callbacks(void)
+{
+ __rcu_process_callbacks(&rcu_preempt_state,
+ &__get_cpu_var(rcu_preempt_data));
+}
+
+/*
+ * Queue a preemptable-RCU callback for invocation after a grace period.
+ */
+void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
+{
+ __call_rcu(head, func, &rcu_preempt_state);
+}
+EXPORT_SYMBOL_GPL(call_rcu);
+
+/*
+ * Check to see if there is any immediate preemptable-RCU-related work
+ * to be done.
+ */
+static int rcu_preempt_pending(int cpu)
+{
+ return __rcu_pending(&rcu_preempt_state,
+ &per_cpu(rcu_preempt_data, cpu));
+}
+
+/*
+ * Does preemptable RCU need the CPU to stay out of dynticks mode?
+ */
+static int rcu_preempt_needs_cpu(int cpu)
+{
+ return !!per_cpu(rcu_preempt_data, cpu).nxtlist;
+}
+
+/*
+ * Initialize preemptable RCU's per-CPU data.
+ */
+static void __cpuinit rcu_preempt_init_percpu_data(int cpu)
+{
+ rcu_init_percpu_data(cpu, &rcu_preempt_state, 1);
+}
+
+/*
+ * Check for a task exiting while in a preemptable-RCU read-side
+ * critical section, clean up if so. No need to issue warnings,
+ * as debug_check_no_locks_held() already does this if lockdep
+ * is enabled.
+ */
+void exit_rcu(void)
+{
+ struct task_struct *t = current;
+
+ if (t->rcu_read_lock_nesting == 0)
+ return;
+ t->rcu_read_lock_nesting = 1;
+ rcu_read_unlock();
+}
+
+#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */
+
+/*
+ * Tell them what RCU they are running.
+ */
+static inline void rcu_bootup_announce(void)
+{
+ printk(KERN_INFO "Hierarchical RCU implementation.\n");
+}
+
+/*
+ * Return the number of RCU batches processed thus far for debug & stats.
+ */
+long rcu_batches_completed(void)
+{
+ return rcu_batches_completed_sched();
+}
+EXPORT_SYMBOL_GPL(rcu_batches_completed);
+
+/*
+ * Because preemptable RCU does not exist, we never have to check for
+ * CPUs being in quiescent states.
+ */
+static void rcu_preempt_qs(int cpu)
+{
+}
+
+#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
+
+/*
+ * Because preemptable RCU does not exist, we never have to check for
+ * tasks blocked within RCU read-side critical sections.
+ */
+static void rcu_print_task_stall(struct rcu_node *rnp)
+{
+}
+
+#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+
+/*
+ * Because preemptable RCU does not exist, there are never any preempted
+ * RCU readers.
+ */
+static int rcu_preempted_readers(struct rcu_node *rnp)
+{
+ return 0;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+/*
+ * Because preemptable RCU does not exist, it never needs to migrate
+ * tasks that were blocked within RCU read-side critical sections.
+ */
+static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
+ struct rcu_node *rnp)
+{
+}
+
+/*
+ * Because preemptable RCU does not exist, it never needs CPU-offline
+ * processing.
+ */
+static void rcu_preempt_offline_cpu(int cpu)
+{
+}
+
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+
+/*
+ * Because preemptable RCU does not exist, it never has any callbacks
+ * to check.
+ */
+void rcu_preempt_check_callbacks(int cpu)
+{
+}
+
+/*
+ * Because preemptable RCU does not exist, it never has any callbacks
+ * to process.
+ */
+void rcu_preempt_process_callbacks(void)
+{
+}
+
+/*
+ * In classic RCU, call_rcu() is just call_rcu_sched().
+ */
+void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
+{
+ call_rcu_sched(head, func);
+}
+EXPORT_SYMBOL_GPL(call_rcu);
+
+/*
+ * Because preemptable RCU does not exist, it never has any work to do.
+ */
+static int rcu_preempt_pending(int cpu)
+{
+ return 0;
+}
+
+/*
+ * Because preemptable RCU does not exist, it never needs any CPU.
+ */
+static int rcu_preempt_needs_cpu(int cpu)
+{
+ return 0;
+}
+
+/*
+ * Because preemptable RCU does not exist, there is no per-CPU
+ * data to initialize.
+ */
+static void __cpuinit rcu_preempt_init_percpu_data(int cpu)
+{
+}
+
+#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c
index fe1dcdbf1ca3..0ea1bff69727 100644
--- a/kernel/rcutree_trace.c
+++ b/kernel/rcutree_trace.c
@@ -43,6 +43,7 @@
#include <linux/debugfs.h>
#include <linux/seq_file.h>
+#define RCU_TREE_NONCORE
#include "rcutree.h"
static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
@@ -76,8 +77,12 @@ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
static int show_rcudata(struct seq_file *m, void *unused)
{
- seq_puts(m, "rcu:\n");
- PRINT_RCU_DATA(rcu_data, print_one_rcu_data, m);
+#ifdef CONFIG_TREE_PREEMPT_RCU
+ seq_puts(m, "rcu_preempt:\n");
+ PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data, m);
+#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
+ seq_puts(m, "rcu_sched:\n");
+ PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data, m);
seq_puts(m, "rcu_bh:\n");
PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data, m);
return 0;
@@ -102,7 +107,7 @@ static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
return;
seq_printf(m, "%d,%s,%ld,%ld,%d,%ld,%d",
rdp->cpu,
- cpu_is_offline(rdp->cpu) ? "\"Y\"" : "\"N\"",
+ cpu_is_offline(rdp->cpu) ? "\"N\"" : "\"Y\"",
rdp->completed, rdp->gpnum,
rdp->passed_quiesc, rdp->passed_quiesc_completed,
rdp->qs_pending);
@@ -124,8 +129,12 @@ static int show_rcudata_csv(struct seq_file *m, void *unused)
seq_puts(m, "\"dt\",\"dt nesting\",\"dn\",\"df\",");
#endif /* #ifdef CONFIG_NO_HZ */
seq_puts(m, "\"of\",\"ri\",\"ql\",\"b\"\n");
- seq_puts(m, "\"rcu:\"\n");
- PRINT_RCU_DATA(rcu_data, print_one_rcu_data_csv, m);
+#ifdef CONFIG_TREE_PREEMPT_RCU
+ seq_puts(m, "\"rcu_preempt:\"\n");
+ PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data_csv, m);
+#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
+ seq_puts(m, "\"rcu_sched:\"\n");
+ PRINT_RCU_DATA(rcu_sched_data, print_one_rcu_data_csv, m);
seq_puts(m, "\"rcu_bh:\"\n");
PRINT_RCU_DATA(rcu_bh_data, print_one_rcu_data_csv, m);
return 0;
@@ -171,8 +180,12 @@ static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
static int show_rcuhier(struct seq_file *m, void *unused)
{
- seq_puts(m, "rcu:\n");
- print_one_rcu_state(m, &rcu_state);
+#ifdef CONFIG_TREE_PREEMPT_RCU
+ seq_puts(m, "rcu_preempt:\n");
+ print_one_rcu_state(m, &rcu_preempt_state);
+#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
+ seq_puts(m, "rcu_sched:\n");
+ print_one_rcu_state(m, &rcu_sched_state);
seq_puts(m, "rcu_bh:\n");
print_one_rcu_state(m, &rcu_bh_state);
return 0;
@@ -193,8 +206,12 @@ static struct file_operations rcuhier_fops = {
static int show_rcugp(struct seq_file *m, void *unused)
{
- seq_printf(m, "rcu: completed=%ld gpnum=%ld\n",
- rcu_state.completed, rcu_state.gpnum);
+#ifdef CONFIG_TREE_PREEMPT_RCU
+ seq_printf(m, "rcu_preempt: completed=%ld gpnum=%ld\n",
+ rcu_preempt_state.completed, rcu_preempt_state.gpnum);
+#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
+ seq_printf(m, "rcu_sched: completed=%ld gpnum=%ld\n",
+ rcu_sched_state.completed, rcu_sched_state.gpnum);
seq_printf(m, "rcu_bh: completed=%ld gpnum=%ld\n",
rcu_bh_state.completed, rcu_bh_state.gpnum);
return 0;
@@ -243,8 +260,12 @@ static void print_rcu_pendings(struct seq_file *m, struct rcu_state *rsp)
static int show_rcu_pending(struct seq_file *m, void *unused)
{
- seq_puts(m, "rcu:\n");
- print_rcu_pendings(m, &rcu_state);
+#ifdef CONFIG_TREE_PREEMPT_RCU
+ seq_puts(m, "rcu_preempt:\n");
+ print_rcu_pendings(m, &rcu_preempt_state);
+#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
+ seq_puts(m, "rcu_sched:\n");
+ print_rcu_pendings(m, &rcu_sched_state);
seq_puts(m, "rcu_bh:\n");
print_rcu_pendings(m, &rcu_bh_state);
return 0;
@@ -264,62 +285,47 @@ static struct file_operations rcu_pending_fops = {
};
static struct dentry *rcudir;
-static struct dentry *datadir;
-static struct dentry *datadir_csv;
-static struct dentry *gpdir;
-static struct dentry *hierdir;
-static struct dentry *rcu_pendingdir;
static int __init rcuclassic_trace_init(void)
{
+ struct dentry *retval;
+
rcudir = debugfs_create_dir("rcu", NULL);
if (!rcudir)
- goto out;
+ goto free_out;
- datadir = debugfs_create_file("rcudata", 0444, rcudir,
+ retval = debugfs_create_file("rcudata", 0444, rcudir,
NULL, &rcudata_fops);
- if (!datadir)
+ if (!retval)
goto free_out;
- datadir_csv = debugfs_create_file("rcudata.csv", 0444, rcudir,
+ retval = debugfs_create_file("rcudata.csv", 0444, rcudir,
NULL, &rcudata_csv_fops);
- if (!datadir_csv)
+ if (!retval)
goto free_out;
- gpdir = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops);
- if (!gpdir)
+ retval = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops);
+ if (!retval)
goto free_out;
- hierdir = debugfs_create_file("rcuhier", 0444, rcudir,
+ retval = debugfs_create_file("rcuhier", 0444, rcudir,
NULL, &rcuhier_fops);
- if (!hierdir)
+ if (!retval)
goto free_out;
- rcu_pendingdir = debugfs_create_file("rcu_pending", 0444, rcudir,
+ retval = debugfs_create_file("rcu_pending", 0444, rcudir,
NULL, &rcu_pending_fops);
- if (!rcu_pendingdir)
+ if (!retval)
goto free_out;
return 0;
free_out:
- if (datadir)
- debugfs_remove(datadir);
- if (datadir_csv)
- debugfs_remove(datadir_csv);
- if (gpdir)
- debugfs_remove(gpdir);
- debugfs_remove(rcudir);
-out:
+ debugfs_remove_recursive(rcudir);
return 1;
}
static void __exit rcuclassic_trace_cleanup(void)
{
- debugfs_remove(datadir);
- debugfs_remove(datadir_csv);
- debugfs_remove(gpdir);
- debugfs_remove(hierdir);
- debugfs_remove(rcu_pendingdir);
- debugfs_remove(rcudir);
+ debugfs_remove_recursive(rcudir);
}
diff --git a/kernel/sched.c b/kernel/sched.c
index 1b59e265273b..e27a53685ed9 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -64,7 +64,6 @@
#include <linux/tsacct_kern.h>
#include <linux/kprobes.h>
#include <linux/delayacct.h>
-#include <linux/reciprocal_div.h>
#include <linux/unistd.h>
#include <linux/pagemap.h>
#include <linux/hrtimer.h>
@@ -120,30 +119,8 @@
*/
#define RUNTIME_INF ((u64)~0ULL)
-#ifdef CONFIG_SMP
-
static void double_rq_lock(struct rq *rq1, struct rq *rq2);
-/*
- * Divide a load by a sched group cpu_power : (load / sg->__cpu_power)
- * Since cpu_power is a 'constant', we can use a reciprocal divide.
- */
-static inline u32 sg_div_cpu_power(const struct sched_group *sg, u32 load)
-{
- return reciprocal_divide(load, sg->reciprocal_cpu_power);
-}
-
-/*
- * Each time a sched group cpu_power is changed,
- * we must compute its reciprocal value
- */
-static inline void sg_inc_cpu_power(struct sched_group *sg, u32 val)
-{
- sg->__cpu_power += val;
- sg->reciprocal_cpu_power = reciprocal_value(sg->__cpu_power);
-}
-#endif
-
static inline int rt_policy(int policy)
{
if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR))
@@ -309,8 +286,8 @@ void set_tg_uid(struct user_struct *user)
/*
* Root task group.
- * Every UID task group (including init_task_group aka UID-0) will
- * be a child to this group.
+ * Every UID task group (including init_task_group aka UID-0) will
+ * be a child to this group.
*/
struct task_group root_task_group;
@@ -318,7 +295,7 @@ struct task_group root_task_group;
/* Default task group's sched entity on each cpu */
static DEFINE_PER_CPU(struct sched_entity, init_sched_entity);
/* Default task group's cfs_rq on each cpu */
-static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp;
+static DEFINE_PER_CPU(struct cfs_rq, init_tg_cfs_rq) ____cacheline_aligned_in_smp;
#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
@@ -616,6 +593,7 @@ struct rq {
unsigned char idle_at_tick;
/* For active balancing */
+ int post_schedule;
int active_balance;
int push_cpu;
/* cpu of this runqueue: */
@@ -626,6 +604,9 @@ struct rq {
struct task_struct *migration_thread;
struct list_head migration_queue;
+
+ u64 rt_avg;
+ u64 age_stamp;
#endif
/* calc_load related fields */
@@ -693,6 +674,7 @@ static inline int cpu_of(struct rq *rq)
#define this_rq() (&__get_cpu_var(runqueues))
#define task_rq(p) cpu_rq(task_cpu(p))
#define cpu_curr(cpu) (cpu_rq(cpu)->curr)
+#define raw_rq() (&__raw_get_cpu_var(runqueues))
inline void update_rq_clock(struct rq *rq)
{
@@ -861,6 +843,14 @@ unsigned int sysctl_sched_shares_ratelimit = 250000;
unsigned int sysctl_sched_shares_thresh = 4;
/*
+ * period over which we average the RT time consumption, measured
+ * in ms.
+ *
+ * default: 1s
+ */
+const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC;
+
+/*
* period over which we measure -rt task cpu usage in us.
* default: 1s
*/
@@ -1278,12 +1268,37 @@ void wake_up_idle_cpu(int cpu)
}
#endif /* CONFIG_NO_HZ */
+static u64 sched_avg_period(void)
+{
+ return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
+}
+
+static void sched_avg_update(struct rq *rq)
+{
+ s64 period = sched_avg_period();
+
+ while ((s64)(rq->clock - rq->age_stamp) > period) {
+ rq->age_stamp += period;
+ rq->rt_avg /= 2;
+ }
+}
+
+static void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
+{
+ rq->rt_avg += rt_delta;
+ sched_avg_update(rq);
+}
+
#else /* !CONFIG_SMP */
static void resched_task(struct task_struct *p)
{
assert_spin_locked(&task_rq(p)->lock);
set_tsk_need_resched(p);
}
+
+static void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
+{
+}
#endif /* CONFIG_SMP */
#if BITS_PER_LONG == 32
@@ -1513,28 +1528,35 @@ static unsigned long cpu_avg_load_per_task(int cpu)
#ifdef CONFIG_FAIR_GROUP_SCHED
+struct update_shares_data {
+ unsigned long rq_weight[NR_CPUS];
+};
+
+static DEFINE_PER_CPU(struct update_shares_data, update_shares_data);
+
static void __set_se_shares(struct sched_entity *se, unsigned long shares);
/*
* Calculate and set the cpu's group shares.
*/
-static void
-update_group_shares_cpu(struct task_group *tg, int cpu,
- unsigned long sd_shares, unsigned long sd_rq_weight)
+static void update_group_shares_cpu(struct task_group *tg, int cpu,
+ unsigned long sd_shares,
+ unsigned long sd_rq_weight,
+ struct update_shares_data *usd)
{
- unsigned long shares;
- unsigned long rq_weight;
-
- if (!tg->se[cpu])
- return;
+ unsigned long shares, rq_weight;
+ int boost = 0;
- rq_weight = tg->cfs_rq[cpu]->rq_weight;
+ rq_weight = usd->rq_weight[cpu];
+ if (!rq_weight) {
+ boost = 1;
+ rq_weight = NICE_0_LOAD;
+ }
/*
- * \Sum shares * rq_weight
- * shares = -----------------------
- * \Sum rq_weight
- *
+ * \Sum_j shares_j * rq_weight_i
+ * shares_i = -----------------------------
+ * \Sum_j rq_weight_j
*/
shares = (sd_shares * rq_weight) / sd_rq_weight;
shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES);
@@ -1545,8 +1567,8 @@ update_group_shares_cpu(struct task_group *tg, int cpu,
unsigned long flags;
spin_lock_irqsave(&rq->lock, flags);
- tg->cfs_rq[cpu]->shares = shares;
-
+ tg->cfs_rq[cpu]->rq_weight = boost ? 0 : rq_weight;
+ tg->cfs_rq[cpu]->shares = boost ? 0 : shares;
__set_se_shares(tg->se[cpu], shares);
spin_unlock_irqrestore(&rq->lock, flags);
}
@@ -1559,22 +1581,30 @@ update_group_shares_cpu(struct task_group *tg, int cpu,
*/
static int tg_shares_up(struct task_group *tg, void *data)
{
- unsigned long weight, rq_weight = 0;
- unsigned long shares = 0;
+ unsigned long weight, rq_weight = 0, shares = 0;
+ struct update_shares_data *usd;
struct sched_domain *sd = data;
+ unsigned long flags;
int i;
+ if (!tg->se[0])
+ return 0;
+
+ local_irq_save(flags);
+ usd = &__get_cpu_var(update_shares_data);
+
for_each_cpu(i, sched_domain_span(sd)) {
+ weight = tg->cfs_rq[i]->load.weight;
+ usd->rq_weight[i] = weight;
+
/*
* If there are currently no tasks on the cpu pretend there
* is one of average load so that when a new task gets to
* run here it will not get delayed by group starvation.
*/
- weight = tg->cfs_rq[i]->load.weight;
if (!weight)
weight = NICE_0_LOAD;
- tg->cfs_rq[i]->rq_weight = weight;
rq_weight += weight;
shares += tg->cfs_rq[i]->shares;
}
@@ -1586,7 +1616,9 @@ static int tg_shares_up(struct task_group *tg, void *data)
shares = tg->shares;
for_each_cpu(i, sched_domain_span(sd))
- update_group_shares_cpu(tg, i, shares, rq_weight);
+ update_group_shares_cpu(tg, i, shares, rq_weight, usd);
+
+ local_irq_restore(flags);
return 0;
}
@@ -1616,8 +1648,14 @@ static int tg_load_down(struct task_group *tg, void *data)
static void update_shares(struct sched_domain *sd)
{
- u64 now = cpu_clock(raw_smp_processor_id());
- s64 elapsed = now - sd->last_update;
+ s64 elapsed;
+ u64 now;
+
+ if (root_task_group_empty())
+ return;
+
+ now = cpu_clock(raw_smp_processor_id());
+ elapsed = now - sd->last_update;
if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) {
sd->last_update = now;
@@ -1627,6 +1665,9 @@ static void update_shares(struct sched_domain *sd)
static void update_shares_locked(struct rq *rq, struct sched_domain *sd)
{
+ if (root_task_group_empty())
+ return;
+
spin_unlock(&rq->lock);
update_shares(sd);
spin_lock(&rq->lock);
@@ -1634,6 +1675,9 @@ static void update_shares_locked(struct rq *rq, struct sched_domain *sd)
static void update_h_load(long cpu)
{
+ if (root_task_group_empty())
+ return;
+
walk_tg_tree(tg_load_down, tg_nop, (void *)cpu);
}
@@ -2268,8 +2312,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu)
}
/* Adjust by relative CPU power of the group */
- avg_load = sg_div_cpu_power(group,
- avg_load * SCHED_LOAD_SCALE);
+ avg_load = (avg_load * SCHED_LOAD_SCALE) / group->cpu_power;
if (local_group) {
this_load = avg_load;
@@ -2637,9 +2680,32 @@ void sched_fork(struct task_struct *p, int clone_flags)
set_task_cpu(p, cpu);
/*
- * Make sure we do not leak PI boosting priority to the child:
+ * Make sure we do not leak PI boosting priority to the child.
*/
p->prio = current->normal_prio;
+
+ /*
+ * Revert to default priority/policy on fork if requested.
+ */
+ if (unlikely(p->sched_reset_on_fork)) {
+ if (p->policy == SCHED_FIFO || p->policy == SCHED_RR)
+ p->policy = SCHED_NORMAL;
+
+ if (p->normal_prio < DEFAULT_PRIO)
+ p->prio = DEFAULT_PRIO;
+
+ if (PRIO_TO_NICE(p->static_prio) < 0) {
+ p->static_prio = NICE_TO_PRIO(0);
+ set_load_weight(p);
+ }
+
+ /*
+ * We don't need the reset flag anymore after the fork. It has
+ * fulfilled its duty:
+ */
+ p->sched_reset_on_fork = 0;
+ }
+
if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class;
@@ -2796,12 +2862,6 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
{
struct mm_struct *mm = rq->prev_mm;
long prev_state;
-#ifdef CONFIG_SMP
- int post_schedule = 0;
-
- if (current->sched_class->needs_post_schedule)
- post_schedule = current->sched_class->needs_post_schedule(rq);
-#endif
rq->prev_mm = NULL;
@@ -2820,10 +2880,6 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
finish_arch_switch(prev);
perf_counter_task_sched_in(current, cpu_of(rq));
finish_lock_switch(rq, prev);
-#ifdef CONFIG_SMP
- if (post_schedule)
- current->sched_class->post_schedule(rq);
-#endif
fire_sched_in_preempt_notifiers(current);
if (mm)
@@ -2838,6 +2894,42 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
}
}
+#ifdef CONFIG_SMP
+
+/* assumes rq->lock is held */
+static inline void pre_schedule(struct rq *rq, struct task_struct *prev)
+{
+ if (prev->sched_class->pre_schedule)
+ prev->sched_class->pre_schedule(rq, prev);
+}
+
+/* rq->lock is NOT held, but preemption is disabled */
+static inline void post_schedule(struct rq *rq)
+{
+ if (rq->post_schedule) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&rq->lock, flags);
+ if (rq->curr->sched_class->post_schedule)
+ rq->curr->sched_class->post_schedule(rq);
+ spin_unlock_irqrestore(&rq->lock, flags);
+
+ rq->post_schedule = 0;
+ }
+}
+
+#else
+
+static inline void pre_schedule(struct rq *rq, struct task_struct *p)
+{
+}
+
+static inline void post_schedule(struct rq *rq)
+{
+}
+
+#endif
+
/**
* schedule_tail - first thing a freshly forked thread must call.
* @prev: the thread we just switched away from.
@@ -2848,6 +2940,13 @@ asmlinkage void schedule_tail(struct task_struct *prev)
struct rq *rq = this_rq();
finish_task_switch(rq, prev);
+
+ /*
+ * FIXME: do we need to worry about rq being invalidated by the
+ * task_switch?
+ */
+ post_schedule(rq);
+
#ifdef __ARCH_WANT_UNLOCKED_CTXSW
/* In this case, finish_task_switch does not reenable preemption */
preempt_enable();
@@ -3379,9 +3478,10 @@ static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
{
const struct sched_class *class;
- for (class = sched_class_highest; class; class = class->next)
+ for_each_class(class) {
if (class->move_one_task(this_rq, this_cpu, busiest, sd, idle))
return 1;
+ }
return 0;
}
@@ -3544,7 +3644,7 @@ static inline void update_sd_power_savings_stats(struct sched_group *group,
* capacity but still has some space to pick up some load
* from other group and save more power
*/
- if (sgs->sum_nr_running > sgs->group_capacity - 1)
+ if (sgs->sum_nr_running + 1 > sgs->group_capacity)
return;
if (sgs->sum_nr_running > sds->leader_nr_running ||
@@ -3611,6 +3711,77 @@ static inline int check_power_save_busiest_group(struct sd_lb_stats *sds,
}
#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
+unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu)
+{
+ unsigned long weight = cpumask_weight(sched_domain_span(sd));
+ unsigned long smt_gain = sd->smt_gain;
+
+ smt_gain /= weight;
+
+ return smt_gain;
+}
+
+unsigned long scale_rt_power(int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+ u64 total, available;
+
+ sched_avg_update(rq);
+
+ total = sched_avg_period() + (rq->clock - rq->age_stamp);
+ available = total - rq->rt_avg;
+
+ if (unlikely((s64)total < SCHED_LOAD_SCALE))
+ total = SCHED_LOAD_SCALE;
+
+ total >>= SCHED_LOAD_SHIFT;
+
+ return div_u64(available, total);
+}
+
+static void update_cpu_power(struct sched_domain *sd, int cpu)
+{
+ unsigned long weight = cpumask_weight(sched_domain_span(sd));
+ unsigned long power = SCHED_LOAD_SCALE;
+ struct sched_group *sdg = sd->groups;
+
+ /* here we could scale based on cpufreq */
+
+ if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) {
+ power *= arch_scale_smt_power(sd, cpu);
+ power >>= SCHED_LOAD_SHIFT;
+ }
+
+ power *= scale_rt_power(cpu);
+ power >>= SCHED_LOAD_SHIFT;
+
+ if (!power)
+ power = 1;
+
+ sdg->cpu_power = power;
+}
+
+static void update_group_power(struct sched_domain *sd, int cpu)
+{
+ struct sched_domain *child = sd->child;
+ struct sched_group *group, *sdg = sd->groups;
+ unsigned long power;
+
+ if (!child) {
+ update_cpu_power(sd, cpu);
+ return;
+ }
+
+ power = 0;
+
+ group = child->groups;
+ do {
+ power += group->cpu_power;
+ group = group->next;
+ } while (group != child->groups);
+
+ sdg->cpu_power = power;
+}
/**
* update_sg_lb_stats - Update sched_group's statistics for load balancing.
@@ -3624,7 +3795,8 @@ static inline int check_power_save_busiest_group(struct sd_lb_stats *sds,
* @balance: Should we balance.
* @sgs: variable to hold the statistics for this group.
*/
-static inline void update_sg_lb_stats(struct sched_group *group, int this_cpu,
+static inline void update_sg_lb_stats(struct sched_domain *sd,
+ struct sched_group *group, int this_cpu,
enum cpu_idle_type idle, int load_idx, int *sd_idle,
int local_group, const struct cpumask *cpus,
int *balance, struct sg_lb_stats *sgs)
@@ -3635,8 +3807,11 @@ static inline void update_sg_lb_stats(struct sched_group *group, int this_cpu,
unsigned long sum_avg_load_per_task;
unsigned long avg_load_per_task;
- if (local_group)
+ if (local_group) {
balance_cpu = group_first_cpu(group);
+ if (balance_cpu == this_cpu)
+ update_group_power(sd, this_cpu);
+ }
/* Tally up the load of all CPUs in the group */
sum_avg_load_per_task = avg_load_per_task = 0;
@@ -3685,8 +3860,7 @@ static inline void update_sg_lb_stats(struct sched_group *group, int this_cpu,
}
/* Adjust by relative CPU power of the group */
- sgs->avg_load = sg_div_cpu_power(group,
- sgs->group_load * SCHED_LOAD_SCALE);
+ sgs->avg_load = (sgs->group_load * SCHED_LOAD_SCALE) / group->cpu_power;
/*
@@ -3698,14 +3872,14 @@ static inline void update_sg_lb_stats(struct sched_group *group, int this_cpu,
* normalized nr_running number somewhere that negates
* the hierarchy?
*/
- avg_load_per_task = sg_div_cpu_power(group,
- sum_avg_load_per_task * SCHED_LOAD_SCALE);
+ avg_load_per_task = (sum_avg_load_per_task * SCHED_LOAD_SCALE) /
+ group->cpu_power;
if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task)
sgs->group_imb = 1;
- sgs->group_capacity = group->__cpu_power / SCHED_LOAD_SCALE;
-
+ sgs->group_capacity =
+ DIV_ROUND_CLOSEST(group->cpu_power, SCHED_LOAD_SCALE);
}
/**
@@ -3723,9 +3897,13 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu,
const struct cpumask *cpus, int *balance,
struct sd_lb_stats *sds)
{
+ struct sched_domain *child = sd->child;
struct sched_group *group = sd->groups;
struct sg_lb_stats sgs;
- int load_idx;
+ int load_idx, prefer_sibling = 0;
+
+ if (child && child->flags & SD_PREFER_SIBLING)
+ prefer_sibling = 1;
init_sd_power_savings_stats(sd, sds, idle);
load_idx = get_sd_load_idx(sd, idle);
@@ -3736,14 +3914,22 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu,
local_group = cpumask_test_cpu(this_cpu,
sched_group_cpus(group));
memset(&sgs, 0, sizeof(sgs));
- update_sg_lb_stats(group, this_cpu, idle, load_idx, sd_idle,
+ update_sg_lb_stats(sd, group, this_cpu, idle, load_idx, sd_idle,
local_group, cpus, balance, &sgs);
if (local_group && balance && !(*balance))
return;
sds->total_load += sgs.group_load;
- sds->total_pwr += group->__cpu_power;
+ sds->total_pwr += group->cpu_power;
+
+ /*
+ * In case the child domain prefers tasks go to siblings
+ * first, lower the group capacity to one so that we'll try
+ * and move all the excess tasks away.
+ */
+ if (prefer_sibling)
+ sgs.group_capacity = min(sgs.group_capacity, 1UL);
if (local_group) {
sds->this_load = sgs.avg_load;
@@ -3763,7 +3949,6 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu,
update_sd_power_savings_stats(group, sds, local_group, &sgs);
group = group->next;
} while (group != sd->groups);
-
}
/**
@@ -3801,28 +3986,28 @@ static inline void fix_small_imbalance(struct sd_lb_stats *sds,
* moving them.
*/
- pwr_now += sds->busiest->__cpu_power *
+ pwr_now += sds->busiest->cpu_power *
min(sds->busiest_load_per_task, sds->max_load);
- pwr_now += sds->this->__cpu_power *
+ pwr_now += sds->this->cpu_power *
min(sds->this_load_per_task, sds->this_load);
pwr_now /= SCHED_LOAD_SCALE;
/* Amount of load we'd subtract */
- tmp = sg_div_cpu_power(sds->busiest,
- sds->busiest_load_per_task * SCHED_LOAD_SCALE);
+ tmp = (sds->busiest_load_per_task * SCHED_LOAD_SCALE) /
+ sds->busiest->cpu_power;
if (sds->max_load > tmp)
- pwr_move += sds->busiest->__cpu_power *
+ pwr_move += sds->busiest->cpu_power *
min(sds->busiest_load_per_task, sds->max_load - tmp);
/* Amount of load we'd add */
- if (sds->max_load * sds->busiest->__cpu_power <
+ if (sds->max_load * sds->busiest->cpu_power <
sds->busiest_load_per_task * SCHED_LOAD_SCALE)
- tmp = sg_div_cpu_power(sds->this,
- sds->max_load * sds->busiest->__cpu_power);
+ tmp = (sds->max_load * sds->busiest->cpu_power) /
+ sds->this->cpu_power;
else
- tmp = sg_div_cpu_power(sds->this,
- sds->busiest_load_per_task * SCHED_LOAD_SCALE);
- pwr_move += sds->this->__cpu_power *
+ tmp = (sds->busiest_load_per_task * SCHED_LOAD_SCALE) /
+ sds->this->cpu_power;
+ pwr_move += sds->this->cpu_power *
min(sds->this_load_per_task, sds->this_load + tmp);
pwr_move /= SCHED_LOAD_SCALE;
@@ -3857,8 +4042,8 @@ static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu,
sds->max_load - sds->busiest_load_per_task);
/* How much load to actually move to equalise the imbalance */
- *imbalance = min(max_pull * sds->busiest->__cpu_power,
- (sds->avg_load - sds->this_load) * sds->this->__cpu_power)
+ *imbalance = min(max_pull * sds->busiest->cpu_power,
+ (sds->avg_load - sds->this_load) * sds->this->cpu_power)
/ SCHED_LOAD_SCALE;
/*
@@ -3976,6 +4161,26 @@ ret:
return NULL;
}
+static struct sched_group *group_of(int cpu)
+{
+ struct sched_domain *sd = rcu_dereference(cpu_rq(cpu)->sd);
+
+ if (!sd)
+ return NULL;
+
+ return sd->groups;
+}
+
+static unsigned long power_of(int cpu)
+{
+ struct sched_group *group = group_of(cpu);
+
+ if (!group)
+ return SCHED_LOAD_SCALE;
+
+ return group->cpu_power;
+}
+
/*
* find_busiest_queue - find the busiest runqueue among the cpus in group.
*/
@@ -3988,15 +4193,18 @@ find_busiest_queue(struct sched_group *group, enum cpu_idle_type idle,
int i;
for_each_cpu(i, sched_group_cpus(group)) {
+ unsigned long power = power_of(i);
+ unsigned long capacity = DIV_ROUND_CLOSEST(power, SCHED_LOAD_SCALE);
unsigned long wl;
if (!cpumask_test_cpu(i, cpus))
continue;
rq = cpu_rq(i);
- wl = weighted_cpuload(i);
+ wl = weighted_cpuload(i) * SCHED_LOAD_SCALE;
+ wl /= power;
- if (rq->nr_running == 1 && wl > imbalance)
+ if (capacity && rq->nr_running == 1 && wl > imbalance)
continue;
if (wl > max_load) {
@@ -5325,7 +5533,7 @@ need_resched:
preempt_disable();
cpu = smp_processor_id();
rq = cpu_rq(cpu);
- rcu_qsctr_inc(cpu);
+ rcu_sched_qs(cpu);
prev = rq->curr;
switch_count = &prev->nivcsw;
@@ -5349,10 +5557,7 @@ need_resched_nonpreemptible:
switch_count = &prev->nvcsw;
}
-#ifdef CONFIG_SMP
- if (prev->sched_class->pre_schedule)
- prev->sched_class->pre_schedule(rq, prev);
-#endif
+ pre_schedule(rq, prev);
if (unlikely(!rq->nr_running))
idle_balance(cpu, rq);
@@ -5378,6 +5583,8 @@ need_resched_nonpreemptible:
} else
spin_unlock_irq(&rq->lock);
+ post_schedule(rq);
+
if (unlikely(reacquire_kernel_lock(current) < 0))
goto need_resched_nonpreemptible;
@@ -6123,17 +6330,25 @@ static int __sched_setscheduler(struct task_struct *p, int policy,
unsigned long flags;
const struct sched_class *prev_class = p->sched_class;
struct rq *rq;
+ int reset_on_fork;
/* may grab non-irq protected spin_locks */
BUG_ON(in_interrupt());
recheck:
/* double check policy once rq lock held */
- if (policy < 0)
+ if (policy < 0) {
+ reset_on_fork = p->sched_reset_on_fork;
policy = oldpolicy = p->policy;
- else if (policy != SCHED_FIFO && policy != SCHED_RR &&
- policy != SCHED_NORMAL && policy != SCHED_BATCH &&
- policy != SCHED_IDLE)
- return -EINVAL;
+ } else {
+ reset_on_fork = !!(policy & SCHED_RESET_ON_FORK);
+ policy &= ~SCHED_RESET_ON_FORK;
+
+ if (policy != SCHED_FIFO && policy != SCHED_RR &&
+ policy != SCHED_NORMAL && policy != SCHED_BATCH &&
+ policy != SCHED_IDLE)
+ return -EINVAL;
+ }
+
/*
* Valid priorities for SCHED_FIFO and SCHED_RR are
* 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL,
@@ -6177,6 +6392,10 @@ recheck:
/* can't change other user's priorities */
if (!check_same_owner(p))
return -EPERM;
+
+ /* Normal users shall not reset the sched_reset_on_fork flag */
+ if (p->sched_reset_on_fork && !reset_on_fork)
+ return -EPERM;
}
if (user) {
@@ -6220,6 +6439,8 @@ recheck:
if (running)
p->sched_class->put_prev_task(rq, p);
+ p->sched_reset_on_fork = reset_on_fork;
+
oldprio = p->prio;
__setscheduler(rq, p, policy, param->sched_priority);
@@ -6336,14 +6557,15 @@ SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
if (p) {
retval = security_task_getscheduler(p);
if (!retval)
- retval = p->policy;
+ retval = p->policy
+ | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0);
}
read_unlock(&tasklist_lock);
return retval;
}
/**
- * sys_sched_getscheduler - get the RT priority of a thread
+ * sys_sched_getparam - get the RT priority of a thread
* @pid: the pid in question.
* @param: structure containing the RT priority.
*/
@@ -6571,19 +6793,9 @@ static inline int should_resched(void)
static void __cond_resched(void)
{
-#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
- __might_sleep(__FILE__, __LINE__);
-#endif
- /*
- * The BKS might be reacquired before we have dropped
- * PREEMPT_ACTIVE, which could trigger a second
- * cond_resched() call.
- */
- do {
- add_preempt_count(PREEMPT_ACTIVE);
- schedule();
- sub_preempt_count(PREEMPT_ACTIVE);
- } while (need_resched());
+ add_preempt_count(PREEMPT_ACTIVE);
+ schedule();
+ sub_preempt_count(PREEMPT_ACTIVE);
}
int __sched _cond_resched(void)
@@ -6597,18 +6809,20 @@ int __sched _cond_resched(void)
EXPORT_SYMBOL(_cond_resched);
/*
- * cond_resched_lock() - if a reschedule is pending, drop the given lock,
+ * __cond_resched_lock() - if a reschedule is pending, drop the given lock,
* call schedule, and on return reacquire the lock.
*
* This works OK both with and without CONFIG_PREEMPT. We do strange low-level
* operations here to prevent schedule() from being called twice (once via
* spin_unlock(), once by hand).
*/
-int cond_resched_lock(spinlock_t *lock)
+int __cond_resched_lock(spinlock_t *lock)
{
int resched = should_resched();
int ret = 0;
+ lockdep_assert_held(lock);
+
if (spin_needbreak(lock) || resched) {
spin_unlock(lock);
if (resched)
@@ -6620,9 +6834,9 @@ int cond_resched_lock(spinlock_t *lock)
}
return ret;
}
-EXPORT_SYMBOL(cond_resched_lock);
+EXPORT_SYMBOL(__cond_resched_lock);
-int __sched cond_resched_softirq(void)
+int __sched __cond_resched_softirq(void)
{
BUG_ON(!in_softirq());
@@ -6634,7 +6848,7 @@ int __sched cond_resched_softirq(void)
}
return 0;
}
-EXPORT_SYMBOL(cond_resched_softirq);
+EXPORT_SYMBOL(__cond_resched_softirq);
/**
* yield - yield the current processor to other threads.
@@ -6658,11 +6872,13 @@ EXPORT_SYMBOL(yield);
*/
void __sched io_schedule(void)
{
- struct rq *rq = &__raw_get_cpu_var(runqueues);
+ struct rq *rq = raw_rq();
delayacct_blkio_start();
atomic_inc(&rq->nr_iowait);
+ current->in_iowait = 1;
schedule();
+ current->in_iowait = 0;
atomic_dec(&rq->nr_iowait);
delayacct_blkio_end();
}
@@ -6670,12 +6886,14 @@ EXPORT_SYMBOL(io_schedule);
long __sched io_schedule_timeout(long timeout)
{
- struct rq *rq = &__raw_get_cpu_var(runqueues);
+ struct rq *rq = raw_rq();
long ret;
delayacct_blkio_start();
atomic_inc(&rq->nr_iowait);
+ current->in_iowait = 1;
ret = schedule_timeout(timeout);
+ current->in_iowait = 0;
atomic_dec(&rq->nr_iowait);
delayacct_blkio_end();
return ret;
@@ -6992,8 +7210,12 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
if (migrate_task(p, cpumask_any_and(cpu_online_mask, new_mask), &req)) {
/* Need help from migration thread: drop lock and wait. */
+ struct task_struct *mt = rq->migration_thread;
+
+ get_task_struct(mt);
task_rq_unlock(rq, &flags);
wake_up_process(rq->migration_thread);
+ put_task_struct(mt);
wait_for_completion(&req.done);
tlb_migrate_finish(p->mm);
return 0;
@@ -7051,6 +7273,11 @@ fail:
return ret;
}
+#define RCU_MIGRATION_IDLE 0
+#define RCU_MIGRATION_NEED_QS 1
+#define RCU_MIGRATION_GOT_QS 2
+#define RCU_MIGRATION_MUST_SYNC 3
+
/*
* migration_thread - this is a highprio system thread that performs
* thread migration by bumping thread off CPU then 'pushing' onto
@@ -7058,6 +7285,7 @@ fail:
*/
static int migration_thread(void *data)
{
+ int badcpu;
int cpu = (long)data;
struct rq *rq;
@@ -7092,8 +7320,17 @@ static int migration_thread(void *data)
req = list_entry(head->next, struct migration_req, list);
list_del_init(head->next);
- spin_unlock(&rq->lock);
- __migrate_task(req->task, cpu, req->dest_cpu);
+ if (req->task != NULL) {
+ spin_unlock(&rq->lock);
+ __migrate_task(req->task, cpu, req->dest_cpu);
+ } else if (likely(cpu == (badcpu = smp_processor_id()))) {
+ req->dest_cpu = RCU_MIGRATION_GOT_QS;
+ spin_unlock(&rq->lock);
+ } else {
+ req->dest_cpu = RCU_MIGRATION_MUST_SYNC;
+ spin_unlock(&rq->lock);
+ WARN_ONCE(1, "migration_thread() on CPU %d, expected %d\n", badcpu, cpu);
+ }
local_irq_enable();
complete(&req->done);
@@ -7625,7 +7862,7 @@ static int __init migration_init(void)
migration_call(&migration_notifier, CPU_ONLINE, cpu);
register_cpu_notifier(&migration_notifier);
- return err;
+ return 0;
}
early_initcall(migration_init);
#endif
@@ -7672,7 +7909,7 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
break;
}
- if (!group->__cpu_power) {
+ if (!group->cpu_power) {
printk(KERN_CONT "\n");
printk(KERN_ERR "ERROR: domain->cpu_power not "
"set\n");
@@ -7696,9 +7933,9 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group));
printk(KERN_CONT " %s", str);
- if (group->__cpu_power != SCHED_LOAD_SCALE) {
- printk(KERN_CONT " (__cpu_power = %d)",
- group->__cpu_power);
+ if (group->cpu_power != SCHED_LOAD_SCALE) {
+ printk(KERN_CONT " (cpu_power = %d)",
+ group->cpu_power);
}
group = group->next;
@@ -7841,7 +8078,7 @@ static void rq_attach_root(struct rq *rq, struct root_domain *rd)
rq->rd = rd;
cpumask_set_cpu(rq->cpu, rd->span);
- if (cpumask_test_cpu(rq->cpu, cpu_online_mask))
+ if (cpumask_test_cpu(rq->cpu, cpu_active_mask))
set_rq_online(rq);
spin_unlock_irqrestore(&rq->lock, flags);
@@ -7983,7 +8220,7 @@ init_sched_build_groups(const struct cpumask *span,
continue;
cpumask_clear(sched_group_cpus(sg));
- sg->__cpu_power = 0;
+ sg->cpu_power = 0;
for_each_cpu(j, span) {
if (group_fn(j, cpu_map, NULL, tmpmask) != group)
@@ -8091,6 +8328,39 @@ struct static_sched_domain {
DECLARE_BITMAP(span, CONFIG_NR_CPUS);
};
+struct s_data {
+#ifdef CONFIG_NUMA
+ int sd_allnodes;
+ cpumask_var_t domainspan;
+ cpumask_var_t covered;
+ cpumask_var_t notcovered;
+#endif
+ cpumask_var_t nodemask;
+ cpumask_var_t this_sibling_map;
+ cpumask_var_t this_core_map;
+ cpumask_var_t send_covered;
+ cpumask_var_t tmpmask;
+ struct sched_group **sched_group_nodes;
+ struct root_domain *rd;
+};
+
+enum s_alloc {
+ sa_sched_groups = 0,
+ sa_rootdomain,
+ sa_tmpmask,
+ sa_send_covered,
+ sa_this_core_map,
+ sa_this_sibling_map,
+ sa_nodemask,
+ sa_sched_group_nodes,
+#ifdef CONFIG_NUMA
+ sa_notcovered,
+ sa_covered,
+ sa_domainspan,
+#endif
+ sa_none,
+};
+
/*
* SMT sched-domains:
*/
@@ -8208,11 +8478,76 @@ static void init_numa_sched_groups_power(struct sched_group *group_head)
continue;
}
- sg_inc_cpu_power(sg, sd->groups->__cpu_power);
+ sg->cpu_power += sd->groups->cpu_power;
}
sg = sg->next;
} while (sg != group_head);
}
+
+static int build_numa_sched_groups(struct s_data *d,
+ const struct cpumask *cpu_map, int num)
+{
+ struct sched_domain *sd;
+ struct sched_group *sg, *prev;
+ int n, j;
+
+ cpumask_clear(d->covered);
+ cpumask_and(d->nodemask, cpumask_of_node(num), cpu_map);
+ if (cpumask_empty(d->nodemask)) {
+ d->sched_group_nodes[num] = NULL;
+ goto out;
+ }
+
+ sched_domain_node_span(num, d->domainspan);
+ cpumask_and(d->domainspan, d->domainspan, cpu_map);
+
+ sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(),
+ GFP_KERNEL, num);
+ if (!sg) {
+ printk(KERN_WARNING "Can not alloc domain group for node %d\n",
+ num);
+ return -ENOMEM;
+ }
+ d->sched_group_nodes[num] = sg;
+
+ for_each_cpu(j, d->nodemask) {
+ sd = &per_cpu(node_domains, j).sd;
+ sd->groups = sg;
+ }
+
+ sg->cpu_power = 0;
+ cpumask_copy(sched_group_cpus(sg), d->nodemask);
+ sg->next = sg;
+ cpumask_or(d->covered, d->covered, d->nodemask);
+
+ prev = sg;
+ for (j = 0; j < nr_node_ids; j++) {
+ n = (num + j) % nr_node_ids;
+ cpumask_complement(d->notcovered, d->covered);
+ cpumask_and(d->tmpmask, d->notcovered, cpu_map);
+ cpumask_and(d->tmpmask, d->tmpmask, d->domainspan);
+ if (cpumask_empty(d->tmpmask))
+ break;
+ cpumask_and(d->tmpmask, d->tmpmask, cpumask_of_node(n));
+ if (cpumask_empty(d->tmpmask))
+ continue;
+ sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(),
+ GFP_KERNEL, num);
+ if (!sg) {
+ printk(KERN_WARNING
+ "Can not alloc domain group for node %d\n", j);
+ return -ENOMEM;
+ }
+ sg->cpu_power = 0;
+ cpumask_copy(sched_group_cpus(sg), d->tmpmask);
+ sg->next = prev->next;
+ cpumask_or(d->covered, d->covered, d->tmpmask);
+ prev->next = sg;
+ prev = sg;
+ }
+out:
+ return 0;
+}
#endif /* CONFIG_NUMA */
#ifdef CONFIG_NUMA
@@ -8266,15 +8601,13 @@ static void free_sched_groups(const struct cpumask *cpu_map,
* there are asymmetries in the topology. If there are asymmetries, group
* having more cpu_power will pickup more load compared to the group having
* less cpu_power.
- *
- * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents
- * the maximum number of tasks a group can handle in the presence of other idle
- * or lightly loaded groups in the same sched domain.
*/
static void init_sched_groups_power(int cpu, struct sched_domain *sd)
{
struct sched_domain *child;
struct sched_group *group;
+ long power;
+ int weight;
WARN_ON(!sd || !sd->groups);
@@ -8283,28 +8616,32 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd)
child = sd->child;
- sd->groups->__cpu_power = 0;
+ sd->groups->cpu_power = 0;
- /*
- * For perf policy, if the groups in child domain share resources
- * (for example cores sharing some portions of the cache hierarchy
- * or SMT), then set this domain groups cpu_power such that each group
- * can handle only one task, when there are other idle groups in the
- * same sched domain.
- */
- if (!child || (!(sd->flags & SD_POWERSAVINGS_BALANCE) &&
- (child->flags &
- (SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES)))) {
- sg_inc_cpu_power(sd->groups, SCHED_LOAD_SCALE);
+ if (!child) {
+ power = SCHED_LOAD_SCALE;
+ weight = cpumask_weight(sched_domain_span(sd));
+ /*
+ * SMT siblings share the power of a single core.
+ * Usually multiple threads get a better yield out of
+ * that one core than a single thread would have,
+ * reflect that in sd->smt_gain.
+ */
+ if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) {
+ power *= sd->smt_gain;
+ power /= weight;
+ power >>= SCHED_LOAD_SHIFT;
+ }
+ sd->groups->cpu_power += power;
return;
}
/*
- * add cpu_power of each child group to this groups cpu_power
+ * Add cpu_power of each child group to this groups cpu_power.
*/
group = child->groups;
do {
- sg_inc_cpu_power(sd->groups, group->__cpu_power);
+ sd->groups->cpu_power += group->cpu_power;
group = group->next;
} while (group != child->groups);
}
@@ -8378,280 +8715,285 @@ static void set_domain_attribute(struct sched_domain *sd,
}
}
-/*
- * Build sched domains for a given set of cpus and attach the sched domains
- * to the individual cpus
- */
-static int __build_sched_domains(const struct cpumask *cpu_map,
- struct sched_domain_attr *attr)
-{
- int i, err = -ENOMEM;
- struct root_domain *rd;
- cpumask_var_t nodemask, this_sibling_map, this_core_map, send_covered,
- tmpmask;
+static void __free_domain_allocs(struct s_data *d, enum s_alloc what,
+ const struct cpumask *cpu_map)
+{
+ switch (what) {
+ case sa_sched_groups:
+ free_sched_groups(cpu_map, d->tmpmask); /* fall through */
+ d->sched_group_nodes = NULL;
+ case sa_rootdomain:
+ free_rootdomain(d->rd); /* fall through */
+ case sa_tmpmask:
+ free_cpumask_var(d->tmpmask); /* fall through */
+ case sa_send_covered:
+ free_cpumask_var(d->send_covered); /* fall through */
+ case sa_this_core_map:
+ free_cpumask_var(d->this_core_map); /* fall through */
+ case sa_this_sibling_map:
+ free_cpumask_var(d->this_sibling_map); /* fall through */
+ case sa_nodemask:
+ free_cpumask_var(d->nodemask); /* fall through */
+ case sa_sched_group_nodes:
#ifdef CONFIG_NUMA
- cpumask_var_t domainspan, covered, notcovered;
- struct sched_group **sched_group_nodes = NULL;
- int sd_allnodes = 0;
-
- if (!alloc_cpumask_var(&domainspan, GFP_KERNEL))
- goto out;
- if (!alloc_cpumask_var(&covered, GFP_KERNEL))
- goto free_domainspan;
- if (!alloc_cpumask_var(&notcovered, GFP_KERNEL))
- goto free_covered;
-#endif
-
- if (!alloc_cpumask_var(&nodemask, GFP_KERNEL))
- goto free_notcovered;
- if (!alloc_cpumask_var(&this_sibling_map, GFP_KERNEL))
- goto free_nodemask;
- if (!alloc_cpumask_var(&this_core_map, GFP_KERNEL))
- goto free_this_sibling_map;
- if (!alloc_cpumask_var(&send_covered, GFP_KERNEL))
- goto free_this_core_map;
- if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
- goto free_send_covered;
+ kfree(d->sched_group_nodes); /* fall through */
+ case sa_notcovered:
+ free_cpumask_var(d->notcovered); /* fall through */
+ case sa_covered:
+ free_cpumask_var(d->covered); /* fall through */
+ case sa_domainspan:
+ free_cpumask_var(d->domainspan); /* fall through */
+#endif
+ case sa_none:
+ break;
+ }
+}
+static enum s_alloc __visit_domain_allocation_hell(struct s_data *d,
+ const struct cpumask *cpu_map)
+{
#ifdef CONFIG_NUMA
- /*
- * Allocate the per-node list of sched groups
- */
- sched_group_nodes = kcalloc(nr_node_ids, sizeof(struct sched_group *),
- GFP_KERNEL);
- if (!sched_group_nodes) {
+ if (!alloc_cpumask_var(&d->domainspan, GFP_KERNEL))
+ return sa_none;
+ if (!alloc_cpumask_var(&d->covered, GFP_KERNEL))
+ return sa_domainspan;
+ if (!alloc_cpumask_var(&d->notcovered, GFP_KERNEL))
+ return sa_covered;
+ /* Allocate the per-node list of sched groups */
+ d->sched_group_nodes = kcalloc(nr_node_ids,
+ sizeof(struct sched_group *), GFP_KERNEL);
+ if (!d->sched_group_nodes) {
printk(KERN_WARNING "Can not alloc sched group node list\n");
- goto free_tmpmask;
- }
-#endif
-
- rd = alloc_rootdomain();
- if (!rd) {
+ return sa_notcovered;
+ }
+ sched_group_nodes_bycpu[cpumask_first(cpu_map)] = d->sched_group_nodes;
+#endif
+ if (!alloc_cpumask_var(&d->nodemask, GFP_KERNEL))
+ return sa_sched_group_nodes;
+ if (!alloc_cpumask_var(&d->this_sibling_map, GFP_KERNEL))
+ return sa_nodemask;
+ if (!alloc_cpumask_var(&d->this_core_map, GFP_KERNEL))
+ return sa_this_sibling_map;
+ if (!alloc_cpumask_var(&d->send_covered, GFP_KERNEL))
+ return sa_this_core_map;
+ if (!alloc_cpumask_var(&d->tmpmask, GFP_KERNEL))
+ return sa_send_covered;
+ d->rd = alloc_rootdomain();
+ if (!d->rd) {
printk(KERN_WARNING "Cannot alloc root domain\n");
- goto free_sched_groups;
+ return sa_tmpmask;
}
+ return sa_rootdomain;
+}
+static struct sched_domain *__build_numa_sched_domains(struct s_data *d,
+ const struct cpumask *cpu_map, struct sched_domain_attr *attr, int i)
+{
+ struct sched_domain *sd = NULL;
#ifdef CONFIG_NUMA
- sched_group_nodes_bycpu[cpumask_first(cpu_map)] = sched_group_nodes;
-#endif
-
- /*
- * Set up domains for cpus specified by the cpu_map.
- */
- for_each_cpu(i, cpu_map) {
- struct sched_domain *sd = NULL, *p;
-
- cpumask_and(nodemask, cpumask_of_node(cpu_to_node(i)), cpu_map);
-
-#ifdef CONFIG_NUMA
- if (cpumask_weight(cpu_map) >
- SD_NODES_PER_DOMAIN*cpumask_weight(nodemask)) {
- sd = &per_cpu(allnodes_domains, i).sd;
- SD_INIT(sd, ALLNODES);
- set_domain_attribute(sd, attr);
- cpumask_copy(sched_domain_span(sd), cpu_map);
- cpu_to_allnodes_group(i, cpu_map, &sd->groups, tmpmask);
- p = sd;
- sd_allnodes = 1;
- } else
- p = NULL;
+ struct sched_domain *parent;
- sd = &per_cpu(node_domains, i).sd;
- SD_INIT(sd, NODE);
+ d->sd_allnodes = 0;
+ if (cpumask_weight(cpu_map) >
+ SD_NODES_PER_DOMAIN * cpumask_weight(d->nodemask)) {
+ sd = &per_cpu(allnodes_domains, i).sd;
+ SD_INIT(sd, ALLNODES);
set_domain_attribute(sd, attr);
- sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd));
- sd->parent = p;
- if (p)
- p->child = sd;
- cpumask_and(sched_domain_span(sd),
- sched_domain_span(sd), cpu_map);
+ cpumask_copy(sched_domain_span(sd), cpu_map);
+ cpu_to_allnodes_group(i, cpu_map, &sd->groups, d->tmpmask);
+ d->sd_allnodes = 1;
+ }
+ parent = sd;
+
+ sd = &per_cpu(node_domains, i).sd;
+ SD_INIT(sd, NODE);
+ set_domain_attribute(sd, attr);
+ sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd));
+ sd->parent = parent;
+ if (parent)
+ parent->child = sd;
+ cpumask_and(sched_domain_span(sd), sched_domain_span(sd), cpu_map);
#endif
+ return sd;
+}
- p = sd;
- sd = &per_cpu(phys_domains, i).sd;
- SD_INIT(sd, CPU);
- set_domain_attribute(sd, attr);
- cpumask_copy(sched_domain_span(sd), nodemask);
- sd->parent = p;
- if (p)
- p->child = sd;
- cpu_to_phys_group(i, cpu_map, &sd->groups, tmpmask);
+static struct sched_domain *__build_cpu_sched_domain(struct s_data *d,
+ const struct cpumask *cpu_map, struct sched_domain_attr *attr,
+ struct sched_domain *parent, int i)
+{
+ struct sched_domain *sd;
+ sd = &per_cpu(phys_domains, i).sd;
+ SD_INIT(sd, CPU);
+ set_domain_attribute(sd, attr);
+ cpumask_copy(sched_domain_span(sd), d->nodemask);
+ sd->parent = parent;
+ if (parent)
+ parent->child = sd;
+ cpu_to_phys_group(i, cpu_map, &sd->groups, d->tmpmask);
+ return sd;
+}
+static struct sched_domain *__build_mc_sched_domain(struct s_data *d,
+ const struct cpumask *cpu_map, struct sched_domain_attr *attr,
+ struct sched_domain *parent, int i)
+{
+ struct sched_domain *sd = parent;
#ifdef CONFIG_SCHED_MC
- p = sd;
- sd = &per_cpu(core_domains, i).sd;
- SD_INIT(sd, MC);
- set_domain_attribute(sd, attr);
- cpumask_and(sched_domain_span(sd), cpu_map,
- cpu_coregroup_mask(i));
- sd->parent = p;
- p->child = sd;
- cpu_to_core_group(i, cpu_map, &sd->groups, tmpmask);
+ sd = &per_cpu(core_domains, i).sd;
+ SD_INIT(sd, MC);
+ set_domain_attribute(sd, attr);
+ cpumask_and(sched_domain_span(sd), cpu_map, cpu_coregroup_mask(i));
+ sd->parent = parent;
+ parent->child = sd;
+ cpu_to_core_group(i, cpu_map, &sd->groups, d->tmpmask);
#endif
+ return sd;
+}
+static struct sched_domain *__build_smt_sched_domain(struct s_data *d,
+ const struct cpumask *cpu_map, struct sched_domain_attr *attr,
+ struct sched_domain *parent, int i)
+{
+ struct sched_domain *sd = parent;
#ifdef CONFIG_SCHED_SMT
- p = sd;
- sd = &per_cpu(cpu_domains, i).sd;
- SD_INIT(sd, SIBLING);
- set_domain_attribute(sd, attr);
- cpumask_and(sched_domain_span(sd),
- topology_thread_cpumask(i), cpu_map);
- sd->parent = p;
- p->child = sd;
- cpu_to_cpu_group(i, cpu_map, &sd->groups, tmpmask);
+ sd = &per_cpu(cpu_domains, i).sd;
+ SD_INIT(sd, SIBLING);
+ set_domain_attribute(sd, attr);
+ cpumask_and(sched_domain_span(sd), cpu_map, topology_thread_cpumask(i));
+ sd->parent = parent;
+ parent->child = sd;
+ cpu_to_cpu_group(i, cpu_map, &sd->groups, d->tmpmask);
#endif
- }
+ return sd;
+}
+static void build_sched_groups(struct s_data *d, enum sched_domain_level l,
+ const struct cpumask *cpu_map, int cpu)
+{
+ switch (l) {
#ifdef CONFIG_SCHED_SMT
- /* Set up CPU (sibling) groups */
- for_each_cpu(i, cpu_map) {
- cpumask_and(this_sibling_map,
- topology_thread_cpumask(i), cpu_map);
- if (i != cpumask_first(this_sibling_map))
- continue;
-
- init_sched_build_groups(this_sibling_map, cpu_map,
- &cpu_to_cpu_group,
- send_covered, tmpmask);
- }
+ case SD_LV_SIBLING: /* set up CPU (sibling) groups */
+ cpumask_and(d->this_sibling_map, cpu_map,
+ topology_thread_cpumask(cpu));
+ if (cpu == cpumask_first(d->this_sibling_map))
+ init_sched_build_groups(d->this_sibling_map, cpu_map,
+ &cpu_to_cpu_group,
+ d->send_covered, d->tmpmask);
+ break;
#endif
-
#ifdef CONFIG_SCHED_MC
- /* Set up multi-core groups */
- for_each_cpu(i, cpu_map) {
- cpumask_and(this_core_map, cpu_coregroup_mask(i), cpu_map);
- if (i != cpumask_first(this_core_map))
- continue;
-
- init_sched_build_groups(this_core_map, cpu_map,
- &cpu_to_core_group,
- send_covered, tmpmask);
- }
+ case SD_LV_MC: /* set up multi-core groups */
+ cpumask_and(d->this_core_map, cpu_map, cpu_coregroup_mask(cpu));
+ if (cpu == cpumask_first(d->this_core_map))
+ init_sched_build_groups(d->this_core_map, cpu_map,
+ &cpu_to_core_group,
+ d->send_covered, d->tmpmask);
+ break;
#endif
-
- /* Set up physical groups */
- for (i = 0; i < nr_node_ids; i++) {
- cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
- if (cpumask_empty(nodemask))
- continue;
-
- init_sched_build_groups(nodemask, cpu_map,
- &cpu_to_phys_group,
- send_covered, tmpmask);
- }
-
+ case SD_LV_CPU: /* set up physical groups */
+ cpumask_and(d->nodemask, cpumask_of_node(cpu), cpu_map);
+ if (!cpumask_empty(d->nodemask))
+ init_sched_build_groups(d->nodemask, cpu_map,
+ &cpu_to_phys_group,
+ d->send_covered, d->tmpmask);
+ break;
#ifdef CONFIG_NUMA
- /* Set up node groups */
- if (sd_allnodes) {
- init_sched_build_groups(cpu_map, cpu_map,
- &cpu_to_allnodes_group,
- send_covered, tmpmask);
+ case SD_LV_ALLNODES:
+ init_sched_build_groups(cpu_map, cpu_map, &cpu_to_allnodes_group,
+ d->send_covered, d->tmpmask);
+ break;
+#endif
+ default:
+ break;
}
+}
- for (i = 0; i < nr_node_ids; i++) {
- /* Set up node groups */
- struct sched_group *sg, *prev;
- int j;
-
- cpumask_clear(covered);
- cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
- if (cpumask_empty(nodemask)) {
- sched_group_nodes[i] = NULL;
- continue;
- }
+/*
+ * Build sched domains for a given set of cpus and attach the sched domains
+ * to the individual cpus
+ */
+static int __build_sched_domains(const struct cpumask *cpu_map,
+ struct sched_domain_attr *attr)
+{
+ enum s_alloc alloc_state = sa_none;
+ struct s_data d;
+ struct sched_domain *sd;
+ int i;
+#ifdef CONFIG_NUMA
+ d.sd_allnodes = 0;
+#endif
- sched_domain_node_span(i, domainspan);
- cpumask_and(domainspan, domainspan, cpu_map);
+ alloc_state = __visit_domain_allocation_hell(&d, cpu_map);
+ if (alloc_state != sa_rootdomain)
+ goto error;
+ alloc_state = sa_sched_groups;
- sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(),
- GFP_KERNEL, i);
- if (!sg) {
- printk(KERN_WARNING "Can not alloc domain group for "
- "node %d\n", i);
- goto error;
- }
- sched_group_nodes[i] = sg;
- for_each_cpu(j, nodemask) {
- struct sched_domain *sd;
+ /*
+ * Set up domains for cpus specified by the cpu_map.
+ */
+ for_each_cpu(i, cpu_map) {
+ cpumask_and(d.nodemask, cpumask_of_node(cpu_to_node(i)),
+ cpu_map);
- sd = &per_cpu(node_domains, j).sd;
- sd->groups = sg;
- }
- sg->__cpu_power = 0;
- cpumask_copy(sched_group_cpus(sg), nodemask);
- sg->next = sg;
- cpumask_or(covered, covered, nodemask);
- prev = sg;
+ sd = __build_numa_sched_domains(&d, cpu_map, attr, i);
+ sd = __build_cpu_sched_domain(&d, cpu_map, attr, sd, i);
+ sd = __build_mc_sched_domain(&d, cpu_map, attr, sd, i);
+ sd = __build_smt_sched_domain(&d, cpu_map, attr, sd, i);
+ }
- for (j = 0; j < nr_node_ids; j++) {
- int n = (i + j) % nr_node_ids;
+ for_each_cpu(i, cpu_map) {
+ build_sched_groups(&d, SD_LV_SIBLING, cpu_map, i);
+ build_sched_groups(&d, SD_LV_MC, cpu_map, i);
+ }
- cpumask_complement(notcovered, covered);
- cpumask_and(tmpmask, notcovered, cpu_map);
- cpumask_and(tmpmask, tmpmask, domainspan);
- if (cpumask_empty(tmpmask))
- break;
+ /* Set up physical groups */
+ for (i = 0; i < nr_node_ids; i++)
+ build_sched_groups(&d, SD_LV_CPU, cpu_map, i);
- cpumask_and(tmpmask, tmpmask, cpumask_of_node(n));
- if (cpumask_empty(tmpmask))
- continue;
+#ifdef CONFIG_NUMA
+ /* Set up node groups */
+ if (d.sd_allnodes)
+ build_sched_groups(&d, SD_LV_ALLNODES, cpu_map, 0);
- sg = kmalloc_node(sizeof(struct sched_group) +
- cpumask_size(),
- GFP_KERNEL, i);
- if (!sg) {
- printk(KERN_WARNING
- "Can not alloc domain group for node %d\n", j);
- goto error;
- }
- sg->__cpu_power = 0;
- cpumask_copy(sched_group_cpus(sg), tmpmask);
- sg->next = prev->next;
- cpumask_or(covered, covered, tmpmask);
- prev->next = sg;
- prev = sg;
- }
- }
+ for (i = 0; i < nr_node_ids; i++)
+ if (build_numa_sched_groups(&d, cpu_map, i))
+ goto error;
#endif
/* Calculate CPU power for physical packages and nodes */
#ifdef CONFIG_SCHED_SMT
for_each_cpu(i, cpu_map) {
- struct sched_domain *sd = &per_cpu(cpu_domains, i).sd;
-
+ sd = &per_cpu(cpu_domains, i).sd;
init_sched_groups_power(i, sd);
}
#endif
#ifdef CONFIG_SCHED_MC
for_each_cpu(i, cpu_map) {
- struct sched_domain *sd = &per_cpu(core_domains, i).sd;
-
+ sd = &per_cpu(core_domains, i).sd;
init_sched_groups_power(i, sd);
}
#endif
for_each_cpu(i, cpu_map) {
- struct sched_domain *sd = &per_cpu(phys_domains, i).sd;
-
+ sd = &per_cpu(phys_domains, i).sd;
init_sched_groups_power(i, sd);
}
#ifdef CONFIG_NUMA
for (i = 0; i < nr_node_ids; i++)
- init_numa_sched_groups_power(sched_group_nodes[i]);
+ init_numa_sched_groups_power(d.sched_group_nodes[i]);
- if (sd_allnodes) {
+ if (d.sd_allnodes) {
struct sched_group *sg;
cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg,
- tmpmask);
+ d.tmpmask);
init_numa_sched_groups_power(sg);
}
#endif
/* Attach the domains */
for_each_cpu(i, cpu_map) {
- struct sched_domain *sd;
#ifdef CONFIG_SCHED_SMT
sd = &per_cpu(cpu_domains, i).sd;
#elif defined(CONFIG_SCHED_MC)
@@ -8659,44 +9001,16 @@ static int __build_sched_domains(const struct cpumask *cpu_map,
#else
sd = &per_cpu(phys_domains, i).sd;
#endif
- cpu_attach_domain(sd, rd, i);
+ cpu_attach_domain(sd, d.rd, i);
}
- err = 0;
-
-free_tmpmask:
- free_cpumask_var(tmpmask);
-free_send_covered:
- free_cpumask_var(send_covered);
-free_this_core_map:
- free_cpumask_var(this_core_map);
-free_this_sibling_map:
- free_cpumask_var(this_sibling_map);
-free_nodemask:
- free_cpumask_var(nodemask);
-free_notcovered:
-#ifdef CONFIG_NUMA
- free_cpumask_var(notcovered);
-free_covered:
- free_cpumask_var(covered);
-free_domainspan:
- free_cpumask_var(domainspan);
-out:
-#endif
- return err;
-
-free_sched_groups:
-#ifdef CONFIG_NUMA
- kfree(sched_group_nodes);
-#endif
- goto free_tmpmask;
+ d.sched_group_nodes = NULL; /* don't free this we still need it */
+ __free_domain_allocs(&d, sa_tmpmask, cpu_map);
+ return 0;
-#ifdef CONFIG_NUMA
error:
- free_sched_groups(cpu_map, tmpmask);
- free_rootdomain(rd);
- goto free_tmpmask;
-#endif
+ __free_domain_allocs(&d, alloc_state, cpu_map);
+ return -ENOMEM;
}
static int build_sched_domains(const struct cpumask *cpu_map)
@@ -9304,11 +9618,11 @@ void __init sched_init(void)
* system cpu resource, based on the weight assigned to root
* user's cpu share (INIT_TASK_GROUP_LOAD). This is accomplished
* by letting tasks of init_task_group sit in a separate cfs_rq
- * (init_cfs_rq) and having one entity represent this group of
+ * (init_tg_cfs_rq) and having one entity represent this group of
* tasks in rq->cfs (i.e init_task_group->se[] != NULL).
*/
init_tg_cfs_entry(&init_task_group,
- &per_cpu(init_cfs_rq, i),
+ &per_cpu(init_tg_cfs_rq, i),
&per_cpu(init_sched_entity, i), i, 1,
root_task_group.se[i]);
@@ -9334,6 +9648,7 @@ void __init sched_init(void)
#ifdef CONFIG_SMP
rq->sd = NULL;
rq->rd = NULL;
+ rq->post_schedule = 0;
rq->active_balance = 0;
rq->next_balance = jiffies;
rq->push_cpu = 0;
@@ -9398,13 +9713,20 @@ void __init sched_init(void)
}
#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
-void __might_sleep(char *file, int line)
+static inline int preempt_count_equals(int preempt_offset)
+{
+ int nested = preempt_count() & ~PREEMPT_ACTIVE;
+
+ return (nested == PREEMPT_INATOMIC_BASE + preempt_offset);
+}
+
+void __might_sleep(char *file, int line, int preempt_offset)
{
#ifdef in_atomic
static unsigned long prev_jiffy; /* ratelimiting */
- if ((!in_atomic() && !irqs_disabled()) ||
- system_state != SYSTEM_RUNNING || oops_in_progress)
+ if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) ||
+ system_state != SYSTEM_RUNNING || oops_in_progress)
return;
if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
return;
@@ -10581,3 +10903,113 @@ struct cgroup_subsys cpuacct_subsys = {
.subsys_id = cpuacct_subsys_id,
};
#endif /* CONFIG_CGROUP_CPUACCT */
+
+#ifndef CONFIG_SMP
+
+int rcu_expedited_torture_stats(char *page)
+{
+ return 0;
+}
+EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats);
+
+void synchronize_sched_expedited(void)
+{
+}
+EXPORT_SYMBOL_GPL(synchronize_sched_expedited);
+
+#else /* #ifndef CONFIG_SMP */
+
+static DEFINE_PER_CPU(struct migration_req, rcu_migration_req);
+static DEFINE_MUTEX(rcu_sched_expedited_mutex);
+
+#define RCU_EXPEDITED_STATE_POST -2
+#define RCU_EXPEDITED_STATE_IDLE -1
+
+static int rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE;
+
+int rcu_expedited_torture_stats(char *page)
+{
+ int cnt = 0;
+ int cpu;
+
+ cnt += sprintf(&page[cnt], "state: %d /", rcu_expedited_state);
+ for_each_online_cpu(cpu) {
+ cnt += sprintf(&page[cnt], " %d:%d",
+ cpu, per_cpu(rcu_migration_req, cpu).dest_cpu);
+ }
+ cnt += sprintf(&page[cnt], "\n");
+ return cnt;
+}
+EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats);
+
+static long synchronize_sched_expedited_count;
+
+/*
+ * Wait for an rcu-sched grace period to elapse, but use "big hammer"
+ * approach to force grace period to end quickly. This consumes
+ * significant time on all CPUs, and is thus not recommended for
+ * any sort of common-case code.
+ *
+ * Note that it is illegal to call this function while holding any
+ * lock that is acquired by a CPU-hotplug notifier. Failing to
+ * observe this restriction will result in deadlock.
+ */
+void synchronize_sched_expedited(void)
+{
+ int cpu;
+ unsigned long flags;
+ bool need_full_sync = 0;
+ struct rq *rq;
+ struct migration_req *req;
+ long snap;
+ int trycount = 0;
+
+ smp_mb(); /* ensure prior mod happens before capturing snap. */
+ snap = ACCESS_ONCE(synchronize_sched_expedited_count) + 1;
+ get_online_cpus();
+ while (!mutex_trylock(&rcu_sched_expedited_mutex)) {
+ put_online_cpus();
+ if (trycount++ < 10)
+ udelay(trycount * num_online_cpus());
+ else {
+ synchronize_sched();
+ return;
+ }
+ if (ACCESS_ONCE(synchronize_sched_expedited_count) - snap > 0) {
+ smp_mb(); /* ensure test happens before caller kfree */
+ return;
+ }
+ get_online_cpus();
+ }
+ rcu_expedited_state = RCU_EXPEDITED_STATE_POST;
+ for_each_online_cpu(cpu) {
+ rq = cpu_rq(cpu);
+ req = &per_cpu(rcu_migration_req, cpu);
+ init_completion(&req->done);
+ req->task = NULL;
+ req->dest_cpu = RCU_MIGRATION_NEED_QS;
+ spin_lock_irqsave(&rq->lock, flags);
+ list_add(&req->list, &rq->migration_queue);
+ spin_unlock_irqrestore(&rq->lock, flags);
+ wake_up_process(rq->migration_thread);
+ }
+ for_each_online_cpu(cpu) {
+ rcu_expedited_state = cpu;
+ req = &per_cpu(rcu_migration_req, cpu);
+ rq = cpu_rq(cpu);
+ wait_for_completion(&req->done);
+ spin_lock_irqsave(&rq->lock, flags);
+ if (unlikely(req->dest_cpu == RCU_MIGRATION_MUST_SYNC))
+ need_full_sync = 1;
+ req->dest_cpu = RCU_MIGRATION_IDLE;
+ spin_unlock_irqrestore(&rq->lock, flags);
+ }
+ rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE;
+ mutex_unlock(&rcu_sched_expedited_mutex);
+ put_online_cpus();
+ if (need_full_sync)
+ synchronize_sched();
+}
+EXPORT_SYMBOL_GPL(synchronize_sched_expedited);
+
+#endif /* #else #ifndef CONFIG_SMP */
diff --git a/kernel/sched_cpupri.c b/kernel/sched_cpupri.c
index d014efbf947a..0f052fc674d5 100644
--- a/kernel/sched_cpupri.c
+++ b/kernel/sched_cpupri.c
@@ -127,21 +127,11 @@ void cpupri_set(struct cpupri *cp, int cpu, int newpri)
/*
* If the cpu was currently mapped to a different value, we
- * first need to unmap the old value
+ * need to map it to the new value then remove the old value.
+ * Note, we must add the new value first, otherwise we risk the
+ * cpu being cleared from pri_active, and this cpu could be
+ * missed for a push or pull.
*/
- if (likely(oldpri != CPUPRI_INVALID)) {
- struct cpupri_vec *vec = &cp->pri_to_cpu[oldpri];
-
- spin_lock_irqsave(&vec->lock, flags);
-
- vec->count--;
- if (!vec->count)
- clear_bit(oldpri, cp->pri_active);
- cpumask_clear_cpu(cpu, vec->mask);
-
- spin_unlock_irqrestore(&vec->lock, flags);
- }
-
if (likely(newpri != CPUPRI_INVALID)) {
struct cpupri_vec *vec = &cp->pri_to_cpu[newpri];
@@ -154,6 +144,18 @@ void cpupri_set(struct cpupri *cp, int cpu, int newpri)
spin_unlock_irqrestore(&vec->lock, flags);
}
+ if (likely(oldpri != CPUPRI_INVALID)) {
+ struct cpupri_vec *vec = &cp->pri_to_cpu[oldpri];
+
+ spin_lock_irqsave(&vec->lock, flags);
+
+ vec->count--;
+ if (!vec->count)
+ clear_bit(oldpri, cp->pri_active);
+ cpumask_clear_cpu(cpu, vec->mask);
+
+ spin_unlock_irqrestore(&vec->lock, flags);
+ }
*currpri = newpri;
}
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 70c7e0b79946..5ddbd0891267 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -409,6 +409,8 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
PN(se.wait_max);
PN(se.wait_sum);
P(se.wait_count);
+ PN(se.iowait_sum);
+ P(se.iowait_count);
P(sched_info.bkl_count);
P(se.nr_migrations);
P(se.nr_migrations_cold);
@@ -479,6 +481,8 @@ void proc_sched_set_task(struct task_struct *p)
p->se.wait_max = 0;
p->se.wait_sum = 0;
p->se.wait_count = 0;
+ p->se.iowait_sum = 0;
+ p->se.iowait_count = 0;
p->se.sleep_max = 0;
p->se.sum_sleep_runtime = 0;
p->se.block_max = 0;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 652e8bdef9aa..aa7f84121016 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -24,7 +24,7 @@
/*
* Targeted preemption latency for CPU-bound tasks:
- * (default: 20ms * (1 + ilog(ncpus)), units: nanoseconds)
+ * (default: 5ms * (1 + ilog(ncpus)), units: nanoseconds)
*
* NOTE: this latency value is not the same as the concept of
* 'timeslice length' - timeslices in CFS are of variable length
@@ -34,13 +34,13 @@
* (to see the precise effective timeslice length of your workload,
* run vmstat and monitor the context-switches (cs) field)
*/
-unsigned int sysctl_sched_latency = 20000000ULL;
+unsigned int sysctl_sched_latency = 5000000ULL;
/*
* Minimal preemption granularity for CPU-bound tasks:
- * (default: 4 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
*/
-unsigned int sysctl_sched_min_granularity = 4000000ULL;
+unsigned int sysctl_sched_min_granularity = 1000000ULL;
/*
* is kept at sysctl_sched_latency / sysctl_sched_min_granularity
@@ -48,10 +48,10 @@ unsigned int sysctl_sched_min_granularity = 4000000ULL;
static unsigned int sched_nr_latency = 5;
/*
- * After fork, child runs first. (default) If set to 0 then
+ * After fork, child runs first. If set to 0 (default) then
* parent will (try to) run first.
*/
-const_debug unsigned int sysctl_sched_child_runs_first = 1;
+unsigned int sysctl_sched_child_runs_first __read_mostly;
/*
* sys_sched_yield() compat mode
@@ -63,13 +63,13 @@ unsigned int __read_mostly sysctl_sched_compat_yield;
/*
* SCHED_OTHER wake-up granularity.
- * (default: 5 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
*
* This option delays the preemption effects of decoupled workloads
* and reduces their over-scheduling. Synchronous workloads will still
* have immediate wakeup/sleep latencies.
*/
-unsigned int sysctl_sched_wakeup_granularity = 5000000UL;
+unsigned int sysctl_sched_wakeup_granularity = 1000000UL;
const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
@@ -79,11 +79,6 @@ static const struct sched_class fair_sched_class;
* CFS operations on generic schedulable entities:
*/
-static inline struct task_struct *task_of(struct sched_entity *se)
-{
- return container_of(se, struct task_struct, se);
-}
-
#ifdef CONFIG_FAIR_GROUP_SCHED
/* cpu runqueue to which this cfs_rq is attached */
@@ -95,6 +90,14 @@ static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
/* An entity is a task if it doesn't "own" a runqueue */
#define entity_is_task(se) (!se->my_q)
+static inline struct task_struct *task_of(struct sched_entity *se)
+{
+#ifdef CONFIG_SCHED_DEBUG
+ WARN_ON_ONCE(!entity_is_task(se));
+#endif
+ return container_of(se, struct task_struct, se);
+}
+
/* Walk up scheduling entities hierarchy */
#define for_each_sched_entity(se) \
for (; se; se = se->parent)
@@ -186,7 +189,12 @@ find_matching_se(struct sched_entity **se, struct sched_entity **pse)
}
}
-#else /* CONFIG_FAIR_GROUP_SCHED */
+#else /* !CONFIG_FAIR_GROUP_SCHED */
+
+static inline struct task_struct *task_of(struct sched_entity *se)
+{
+ return container_of(se, struct task_struct, se);
+}
static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
{
@@ -537,6 +545,12 @@ update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
schedstat_set(se->wait_count, se->wait_count + 1);
schedstat_set(se->wait_sum, se->wait_sum +
rq_of(cfs_rq)->clock - se->wait_start);
+#ifdef CONFIG_SCHEDSTATS
+ if (entity_is_task(se)) {
+ trace_sched_stat_wait(task_of(se),
+ rq_of(cfs_rq)->clock - se->wait_start);
+ }
+#endif
schedstat_set(se->wait_start, 0);
}
@@ -628,8 +642,10 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
se->sleep_start = 0;
se->sum_sleep_runtime += delta;
- if (tsk)
+ if (tsk) {
account_scheduler_latency(tsk, delta >> 10, 1);
+ trace_sched_stat_sleep(tsk, delta);
+ }
}
if (se->block_start) {
u64 delta = rq_of(cfs_rq)->clock - se->block_start;
@@ -644,6 +660,12 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
se->sum_sleep_runtime += delta;
if (tsk) {
+ if (tsk->in_iowait) {
+ se->iowait_sum += delta;
+ se->iowait_count++;
+ trace_sched_stat_iowait(tsk, delta);
+ }
+
/*
* Blocking time is in units of nanosecs, so shift by
* 20 to get a milliseconds-range estimation of the
@@ -705,11 +727,11 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
vruntime -= thresh;
}
-
- /* ensure we never gain time by being placed backwards. */
- vruntime = max_vruntime(se->vruntime, vruntime);
}
+ /* ensure we never gain time by being placed backwards. */
+ vruntime = max_vruntime(se->vruntime, vruntime);
+
se->vruntime = vruntime;
}
@@ -1046,17 +1068,21 @@ static void yield_task_fair(struct rq *rq)
* search starts with cpus closest then further out as needed,
* so we always favor a closer, idle cpu.
* Domains may include CPUs that are not usable for migration,
- * hence we need to mask them out (cpu_active_mask)
+ * hence we need to mask them out (rq->rd->online)
*
* Returns the CPU we should wake onto.
*/
#if defined(ARCH_HAS_SCHED_WAKE_IDLE)
+
+#define cpu_rd_active(cpu, rq) cpumask_test_cpu(cpu, rq->rd->online)
+
static int wake_idle(int cpu, struct task_struct *p)
{
struct sched_domain *sd;
int i;
unsigned int chosen_wakeup_cpu;
int this_cpu;
+ struct rq *task_rq = task_rq(p);
/*
* At POWERSAVINGS_BALANCE_WAKEUP level, if both this_cpu and prev_cpu
@@ -1089,10 +1115,10 @@ static int wake_idle(int cpu, struct task_struct *p)
for_each_domain(cpu, sd) {
if ((sd->flags & SD_WAKE_IDLE)
|| ((sd->flags & SD_WAKE_IDLE_FAR)
- && !task_hot(p, task_rq(p)->clock, sd))) {
+ && !task_hot(p, task_rq->clock, sd))) {
for_each_cpu_and(i, sched_domain_span(sd),
&p->cpus_allowed) {
- if (cpu_active(i) && idle_cpu(i)) {
+ if (cpu_rd_active(i, task_rq) && idle_cpu(i)) {
if (i != task_cpu(p)) {
schedstat_inc(p,
se.nr_wakeups_idle);
@@ -1235,7 +1261,17 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
tg = task_group(p);
weight = p->se.load.weight;
- balanced = 100*(tl + effective_load(tg, this_cpu, weight, weight)) <=
+ /*
+ * In low-load situations, where prev_cpu is idle and this_cpu is idle
+ * due to the sync cause above having dropped tl to 0, we'll always have
+ * an imbalance, but there's really nothing you can do about that, so
+ * that's good too.
+ *
+ * Otherwise check if either cpus are near enough in load to allow this
+ * task to be woken on this_cpu.
+ */
+ balanced = !tl ||
+ 100*(tl + effective_load(tg, this_cpu, weight, weight)) <=
imbalance*(load + effective_load(tg, prev_cpu, 0, weight));
/*
@@ -1278,8 +1314,6 @@ static int select_task_rq_fair(struct task_struct *p, int sync)
this_rq = cpu_rq(this_cpu);
new_cpu = prev_cpu;
- if (prev_cpu == this_cpu)
- goto out;
/*
* 'this_sd' is the first domain that both
* this_cpu and prev_cpu are present in:
@@ -1721,6 +1755,8 @@ static void task_new_fair(struct rq *rq, struct task_struct *p)
sched_info_queued(p);
update_curr(cfs_rq);
+ if (curr)
+ se->vruntime = curr->vruntime;
place_entity(cfs_rq, se, 1);
/* 'curr' will be NULL if the child belongs to a different group */
diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index 4569bfa7df9b..e2dc63a5815d 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -1,4 +1,4 @@
-SCHED_FEAT(NEW_FAIR_SLEEPERS, 1)
+SCHED_FEAT(NEW_FAIR_SLEEPERS, 0)
SCHED_FEAT(NORMALIZED_SLEEPER, 0)
SCHED_FEAT(ADAPTIVE_GRAN, 1)
SCHED_FEAT(WAKEUP_PREEMPT, 1)
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 3918e01994e0..2eb4bd6a526c 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -3,15 +3,18 @@
* policies)
*/
+#ifdef CONFIG_RT_GROUP_SCHED
+
+#define rt_entity_is_task(rt_se) (!(rt_se)->my_q)
+
static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
{
+#ifdef CONFIG_SCHED_DEBUG
+ WARN_ON_ONCE(!rt_entity_is_task(rt_se));
+#endif
return container_of(rt_se, struct task_struct, rt);
}
-#ifdef CONFIG_RT_GROUP_SCHED
-
-#define rt_entity_is_task(rt_se) (!(rt_se)->my_q)
-
static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
{
return rt_rq->rq;
@@ -26,6 +29,11 @@ static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
#define rt_entity_is_task(rt_se) (1)
+static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
+{
+ return container_of(rt_se, struct task_struct, rt);
+}
+
static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
{
return container_of(rt_rq, struct rq, rt);
@@ -128,6 +136,11 @@ static void dequeue_pushable_task(struct rq *rq, struct task_struct *p)
plist_del(&p->pushable_tasks, &rq->rt.pushable_tasks);
}
+static inline int has_pushable_tasks(struct rq *rq)
+{
+ return !plist_head_empty(&rq->rt.pushable_tasks);
+}
+
#else
static inline void enqueue_pushable_task(struct rq *rq, struct task_struct *p)
@@ -602,6 +615,8 @@ static void update_curr_rt(struct rq *rq)
curr->se.exec_start = rq->clock;
cpuacct_charge(curr, delta_exec);
+ sched_rt_avg_update(rq, delta_exec);
+
if (!rt_bandwidth_enabled())
return;
@@ -874,8 +889,6 @@ static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup)
if (!task_current(rq, p) && p->rt.nr_cpus_allowed > 1)
enqueue_pushable_task(rq, p);
-
- inc_cpu_load(rq, p->se.load.weight);
}
static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
@@ -886,8 +899,6 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
dequeue_rt_entity(rt_se);
dequeue_pushable_task(rq, p);
-
- dec_cpu_load(rq, p->se.load.weight);
}
/*
@@ -1064,6 +1075,14 @@ static struct task_struct *pick_next_task_rt(struct rq *rq)
if (p)
dequeue_pushable_task(rq, p);
+#ifdef CONFIG_SMP
+ /*
+ * We detect this state here so that we can avoid taking the RQ
+ * lock again later if there is no need to push
+ */
+ rq->post_schedule = has_pushable_tasks(rq);
+#endif
+
return p;
}
@@ -1162,13 +1181,6 @@ static int find_lowest_rq(struct task_struct *task)
return -1; /* No targets found */
/*
- * Only consider CPUs that are usable for migration.
- * I guess we might want to change cpupri_find() to ignore those
- * in the first place.
- */
- cpumask_and(lowest_mask, lowest_mask, cpu_active_mask);
-
- /*
* At this point we have built a mask of cpus representing the
* lowest priority tasks in the system. Now we want to elect
* the best one based on our affinity and topology.
@@ -1262,11 +1274,6 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq)
return lowest_rq;
}
-static inline int has_pushable_tasks(struct rq *rq)
-{
- return !plist_head_empty(&rq->rt.pushable_tasks);
-}
-
static struct task_struct *pick_next_pushable_task(struct rq *rq)
{
struct task_struct *p;
@@ -1466,23 +1473,9 @@ static void pre_schedule_rt(struct rq *rq, struct task_struct *prev)
pull_rt_task(rq);
}
-/*
- * assumes rq->lock is held
- */
-static int needs_post_schedule_rt(struct rq *rq)
-{
- return has_pushable_tasks(rq);
-}
-
static void post_schedule_rt(struct rq *rq)
{
- /*
- * This is only called if needs_post_schedule_rt() indicates that
- * we need to push tasks away
- */
- spin_lock_irq(&rq->lock);
push_rt_tasks(rq);
- spin_unlock_irq(&rq->lock);
}
/*
@@ -1758,7 +1751,6 @@ static const struct sched_class rt_sched_class = {
.rq_online = rq_online_rt,
.rq_offline = rq_offline_rt,
.pre_schedule = pre_schedule_rt,
- .needs_post_schedule = needs_post_schedule_rt,
.post_schedule = post_schedule_rt,
.task_wake_up = task_wake_up_rt,
.switched_from = switched_from_rt,
diff --git a/kernel/softirq.c b/kernel/softirq.c
index eb5e131a0485..7db25067cd2d 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -227,7 +227,7 @@ restart:
preempt_count() = prev_count;
}
- rcu_bh_qsctr_inc(cpu);
+ rcu_bh_qs(cpu);
}
h++;
pending >>= 1;
@@ -721,7 +721,7 @@ static int ksoftirqd(void * __bind_cpu)
preempt_enable_no_resched();
cond_resched();
preempt_disable();
- rcu_qsctr_inc((long)__bind_cpu);
+ rcu_sched_qs((long)__bind_cpu);
}
preempt_enable();
set_current_state(TASK_INTERRUPTIBLE);
diff --git a/kernel/spinlock.c b/kernel/spinlock.c
index 7932653c4ebd..5ddab730cb2f 100644
--- a/kernel/spinlock.c
+++ b/kernel/spinlock.c
@@ -21,44 +21,29 @@
#include <linux/debug_locks.h>
#include <linux/module.h>
+#ifndef _spin_trylock
int __lockfunc _spin_trylock(spinlock_t *lock)
{
- preempt_disable();
- if (_raw_spin_trylock(lock)) {
- spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
- return 1;
- }
-
- preempt_enable();
- return 0;
+ return __spin_trylock(lock);
}
EXPORT_SYMBOL(_spin_trylock);
+#endif
+#ifndef _read_trylock
int __lockfunc _read_trylock(rwlock_t *lock)
{
- preempt_disable();
- if (_raw_read_trylock(lock)) {
- rwlock_acquire_read(&lock->dep_map, 0, 1, _RET_IP_);
- return 1;
- }
-
- preempt_enable();
- return 0;
+ return __read_trylock(lock);
}
EXPORT_SYMBOL(_read_trylock);
+#endif
+#ifndef _write_trylock
int __lockfunc _write_trylock(rwlock_t *lock)
{
- preempt_disable();
- if (_raw_write_trylock(lock)) {
- rwlock_acquire(&lock->dep_map, 0, 1, _RET_IP_);
- return 1;
- }
-
- preempt_enable();
- return 0;
+ return __write_trylock(lock);
}
EXPORT_SYMBOL(_write_trylock);
+#endif
/*
* If lockdep is enabled then we use the non-preemption spin-ops
@@ -67,132 +52,101 @@ EXPORT_SYMBOL(_write_trylock);
*/
#if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC)
+#ifndef _read_lock
void __lockfunc _read_lock(rwlock_t *lock)
{
- preempt_disable();
- rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
- LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
+ __read_lock(lock);
}
EXPORT_SYMBOL(_read_lock);
+#endif
+#ifndef _spin_lock_irqsave
unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
{
- unsigned long flags;
-
- local_irq_save(flags);
- preempt_disable();
- spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
- /*
- * On lockdep we dont want the hand-coded irq-enable of
- * _raw_spin_lock_flags() code, because lockdep assumes
- * that interrupts are not re-enabled during lock-acquire:
- */
-#ifdef CONFIG_LOCKDEP
- LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
-#else
- _raw_spin_lock_flags(lock, &flags);
-#endif
- return flags;
+ return __spin_lock_irqsave(lock);
}
EXPORT_SYMBOL(_spin_lock_irqsave);
+#endif
+#ifndef _spin_lock_irq
void __lockfunc _spin_lock_irq(spinlock_t *lock)
{
- local_irq_disable();
- preempt_disable();
- spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
- LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
+ __spin_lock_irq(lock);
}
EXPORT_SYMBOL(_spin_lock_irq);
+#endif
+#ifndef _spin_lock_bh
void __lockfunc _spin_lock_bh(spinlock_t *lock)
{
- local_bh_disable();
- preempt_disable();
- spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
- LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
+ __spin_lock_bh(lock);
}
EXPORT_SYMBOL(_spin_lock_bh);
+#endif
+#ifndef _read_lock_irqsave
unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
{
- unsigned long flags;
-
- local_irq_save(flags);
- preempt_disable();
- rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
- LOCK_CONTENDED_FLAGS(lock, _raw_read_trylock, _raw_read_lock,
- _raw_read_lock_flags, &flags);
- return flags;
+ return __read_lock_irqsave(lock);
}
EXPORT_SYMBOL(_read_lock_irqsave);
+#endif
+#ifndef _read_lock_irq
void __lockfunc _read_lock_irq(rwlock_t *lock)
{
- local_irq_disable();
- preempt_disable();
- rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
- LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
+ __read_lock_irq(lock);
}
EXPORT_SYMBOL(_read_lock_irq);
+#endif
+#ifndef _read_lock_bh
void __lockfunc _read_lock_bh(rwlock_t *lock)
{
- local_bh_disable();
- preempt_disable();
- rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
- LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
+ __read_lock_bh(lock);
}
EXPORT_SYMBOL(_read_lock_bh);
+#endif
+#ifndef _write_lock_irqsave
unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)
{
- unsigned long flags;
-
- local_irq_save(flags);
- preempt_disable();
- rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
- LOCK_CONTENDED_FLAGS(lock, _raw_write_trylock, _raw_write_lock,
- _raw_write_lock_flags, &flags);
- return flags;
+ return __write_lock_irqsave(lock);
}
EXPORT_SYMBOL(_write_lock_irqsave);
+#endif
+#ifndef _write_lock_irq
void __lockfunc _write_lock_irq(rwlock_t *lock)
{
- local_irq_disable();
- preempt_disable();
- rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
- LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
+ __write_lock_irq(lock);
}
EXPORT_SYMBOL(_write_lock_irq);
+#endif
+#ifndef _write_lock_bh
void __lockfunc _write_lock_bh(rwlock_t *lock)
{
- local_bh_disable();
- preempt_disable();
- rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
- LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
+ __write_lock_bh(lock);
}
EXPORT_SYMBOL(_write_lock_bh);
+#endif
+#ifndef _spin_lock
void __lockfunc _spin_lock(spinlock_t *lock)
{
- preempt_disable();
- spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
- LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
+ __spin_lock(lock);
}
-
EXPORT_SYMBOL(_spin_lock);
+#endif
+#ifndef _write_lock
void __lockfunc _write_lock(rwlock_t *lock)
{
- preempt_disable();
- rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
- LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
+ __write_lock(lock);
}
-
EXPORT_SYMBOL(_write_lock);
+#endif
#else /* CONFIG_PREEMPT: */
@@ -318,125 +272,109 @@ EXPORT_SYMBOL(_spin_lock_nest_lock);
#endif
+#ifndef _spin_unlock
void __lockfunc _spin_unlock(spinlock_t *lock)
{
- spin_release(&lock->dep_map, 1, _RET_IP_);
- _raw_spin_unlock(lock);
- preempt_enable();
+ __spin_unlock(lock);
}
EXPORT_SYMBOL(_spin_unlock);
+#endif
+#ifndef _write_unlock
void __lockfunc _write_unlock(rwlock_t *lock)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
- _raw_write_unlock(lock);
- preempt_enable();
+ __write_unlock(lock);
}
EXPORT_SYMBOL(_write_unlock);
+#endif
+#ifndef _read_unlock
void __lockfunc _read_unlock(rwlock_t *lock)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
- _raw_read_unlock(lock);
- preempt_enable();
+ __read_unlock(lock);
}
EXPORT_SYMBOL(_read_unlock);
+#endif
+#ifndef _spin_unlock_irqrestore
void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
{
- spin_release(&lock->dep_map, 1, _RET_IP_);
- _raw_spin_unlock(lock);
- local_irq_restore(flags);
- preempt_enable();
+ __spin_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(_spin_unlock_irqrestore);
+#endif
+#ifndef _spin_unlock_irq
void __lockfunc _spin_unlock_irq(spinlock_t *lock)
{
- spin_release(&lock->dep_map, 1, _RET_IP_);
- _raw_spin_unlock(lock);
- local_irq_enable();
- preempt_enable();
+ __spin_unlock_irq(lock);
}
EXPORT_SYMBOL(_spin_unlock_irq);
+#endif
+#ifndef _spin_unlock_bh
void __lockfunc _spin_unlock_bh(spinlock_t *lock)
{
- spin_release(&lock->dep_map, 1, _RET_IP_);
- _raw_spin_unlock(lock);
- preempt_enable_no_resched();
- local_bh_enable_ip((unsigned long)__builtin_return_address(0));
+ __spin_unlock_bh(lock);
}
EXPORT_SYMBOL(_spin_unlock_bh);
+#endif
+#ifndef _read_unlock_irqrestore
void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
- _raw_read_unlock(lock);
- local_irq_restore(flags);
- preempt_enable();
+ __read_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(_read_unlock_irqrestore);
+#endif
+#ifndef _read_unlock_irq
void __lockfunc _read_unlock_irq(rwlock_t *lock)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
- _raw_read_unlock(lock);
- local_irq_enable();
- preempt_enable();
+ __read_unlock_irq(lock);
}
EXPORT_SYMBOL(_read_unlock_irq);
+#endif
+#ifndef _read_unlock_bh
void __lockfunc _read_unlock_bh(rwlock_t *lock)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
- _raw_read_unlock(lock);
- preempt_enable_no_resched();
- local_bh_enable_ip((unsigned long)__builtin_return_address(0));
+ __read_unlock_bh(lock);
}
EXPORT_SYMBOL(_read_unlock_bh);
+#endif
+#ifndef _write_unlock_irqrestore
void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
- _raw_write_unlock(lock);
- local_irq_restore(flags);
- preempt_enable();
+ __write_unlock_irqrestore(lock, flags);
}
EXPORT_SYMBOL(_write_unlock_irqrestore);
+#endif
+#ifndef _write_unlock_irq
void __lockfunc _write_unlock_irq(rwlock_t *lock)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
- _raw_write_unlock(lock);
- local_irq_enable();
- preempt_enable();
+ __write_unlock_irq(lock);
}
EXPORT_SYMBOL(_write_unlock_irq);
+#endif
+#ifndef _write_unlock_bh
void __lockfunc _write_unlock_bh(rwlock_t *lock)
{
- rwlock_release(&lock->dep_map, 1, _RET_IP_);
- _raw_write_unlock(lock);
- preempt_enable_no_resched();
- local_bh_enable_ip((unsigned long)__builtin_return_address(0));
+ __write_unlock_bh(lock);
}
EXPORT_SYMBOL(_write_unlock_bh);
+#endif
+#ifndef _spin_trylock_bh
int __lockfunc _spin_trylock_bh(spinlock_t *lock)
{
- local_bh_disable();
- preempt_disable();
- if (_raw_spin_trylock(lock)) {
- spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
- return 1;
- }
-
- preempt_enable_no_resched();
- local_bh_enable_ip((unsigned long)__builtin_return_address(0));
- return 0;
+ return __spin_trylock_bh(lock);
}
EXPORT_SYMBOL(_spin_trylock_bh);
+#endif
notrace int in_lock_functions(unsigned long addr)
{
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 58be76017fd0..3125cff1c570 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -49,7 +49,6 @@
#include <linux/acpi.h>
#include <linux/reboot.h>
#include <linux/ftrace.h>
-#include <linux/security.h>
#include <linux/slow-work.h>
#include <linux/perf_counter.h>
@@ -246,6 +245,14 @@ static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
#endif
static struct ctl_table kern_table[] = {
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "sched_child_runs_first",
+ .data = &sysctl_sched_child_runs_first,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
#ifdef CONFIG_SCHED_DEBUG
{
.ctl_name = CTL_UNNUMBERED,
@@ -300,14 +307,6 @@ static struct ctl_table kern_table[] = {
},
{
.ctl_name = CTL_UNNUMBERED,
- .procname = "sched_child_runs_first",
- .data = &sysctl_sched_child_runs_first,
- .maxlen = sizeof(unsigned int),
- .mode = 0644,
- .proc_handler = &proc_dointvec,
- },
- {
- .ctl_name = CTL_UNNUMBERED,
.procname = "sched_features",
.data = &sysctl_sched_features,
.maxlen = sizeof(unsigned int),
@@ -332,6 +331,14 @@ static struct ctl_table kern_table[] = {
},
{
.ctl_name = CTL_UNNUMBERED,
+ .procname = "sched_time_avg",
+ .data = &sysctl_sched_time_avg,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ {
+ .ctl_name = CTL_UNNUMBERED,
.procname = "timer_migration",
.data = &sysctl_timer_migration,
.maxlen = sizeof(unsigned int),
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 888adbcca30c..ea8384d3caa7 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -108,7 +108,7 @@ static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp,
/*
* Send taskstats data in @skb to listener with nl_pid @pid
*/
-static int send_reply(struct sk_buff *skb, pid_t pid)
+static int send_reply(struct sk_buff *skb, struct genl_info *info)
{
struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb));
void *reply = genlmsg_data(genlhdr);
@@ -120,7 +120,7 @@ static int send_reply(struct sk_buff *skb, pid_t pid)
return rc;
}
- return genlmsg_unicast(skb, pid);
+ return genlmsg_reply(skb, info);
}
/*
@@ -150,7 +150,7 @@ static void send_cpu_listeners(struct sk_buff *skb,
if (!skb_next)
break;
}
- rc = genlmsg_unicast(skb_cur, s->pid);
+ rc = genlmsg_unicast(&init_net, skb_cur, s->pid);
if (rc == -ECONNREFUSED) {
s->valid = 0;
delcount++;
@@ -418,7 +418,7 @@ static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
goto err;
}
- rc = send_reply(rep_skb, info->snd_pid);
+ rc = send_reply(rep_skb, info);
err:
fput_light(file, fput_needed);
@@ -487,7 +487,7 @@ free_return_rc:
} else
goto err;
- return send_reply(rep_skb, info->snd_pid);
+ return send_reply(rep_skb, info);
err:
nlmsg_free(rep_skb);
return rc;
diff --git a/kernel/timer.c b/kernel/timer.c
index a7f07d5a6241..a3d25f415019 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1156,8 +1156,7 @@ void update_process_times(int user_tick)
/* Note: this timer irq context must be accounted for as well. */
account_process_tick(p, user_tick);
run_local_timers();
- if (rcu_pending(cpu))
- rcu_check_callbacks(cpu, user_tick);
+ rcu_check_callbacks(cpu, user_tick);
printk_tick();
scheduler_tick();
run_posix_cpu_timers(p);
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 019f380fd764..1ea0d1234f4a 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -41,7 +41,7 @@ config HAVE_FTRACE_MCOUNT_RECORD
config HAVE_HW_BRANCH_TRACER
bool
-config HAVE_FTRACE_SYSCALLS
+config HAVE_SYSCALL_TRACEPOINTS
bool
config TRACER_MAX_TRACE
@@ -60,9 +60,14 @@ config EVENT_TRACING
bool
config CONTEXT_SWITCH_TRACER
- select MARKERS
bool
+config RING_BUFFER_ALLOW_SWAP
+ bool
+ help
+ Allow the use of ring_buffer_swap_cpu.
+ Adds a very slight overhead to tracing when enabled.
+
# All tracer options should select GENERIC_TRACER. For those options that are
# enabled by all tracers (context switch and event tracer) they select TRACING.
# This allows those options to appear when no other tracer is selected. But the
@@ -147,6 +152,7 @@ config IRQSOFF_TRACER
select TRACE_IRQFLAGS
select GENERIC_TRACER
select TRACER_MAX_TRACE
+ select RING_BUFFER_ALLOW_SWAP
help
This option measures the time spent in irqs-off critical
sections, with microsecond accuracy.
@@ -168,6 +174,7 @@ config PREEMPT_TRACER
depends on PREEMPT
select GENERIC_TRACER
select TRACER_MAX_TRACE
+ select RING_BUFFER_ALLOW_SWAP
help
This option measures the time spent in preemption off critical
sections, with microsecond accuracy.
@@ -211,7 +218,7 @@ config ENABLE_DEFAULT_TRACERS
config FTRACE_SYSCALLS
bool "Trace syscalls"
- depends on HAVE_FTRACE_SYSCALLS
+ depends on HAVE_SYSCALL_TRACEPOINTS
select GENERIC_TRACER
select KALLSYMS
help
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 7a34cb563fec..3eb159c277c8 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -65,13 +65,15 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action,
{
struct blk_io_trace *t;
struct ring_buffer_event *event = NULL;
+ struct ring_buffer *buffer = NULL;
int pc = 0;
int cpu = smp_processor_id();
bool blk_tracer = blk_tracer_enabled;
if (blk_tracer) {
+ buffer = blk_tr->buffer;
pc = preempt_count();
- event = trace_buffer_lock_reserve(blk_tr, TRACE_BLK,
+ event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
sizeof(*t) + len,
0, pc);
if (!event)
@@ -96,7 +98,7 @@ record_it:
memcpy((void *) t + sizeof(*t), data, len);
if (blk_tracer)
- trace_buffer_unlock_commit(blk_tr, event, 0, pc);
+ trace_buffer_unlock_commit(buffer, event, 0, pc);
}
}
@@ -179,6 +181,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
{
struct task_struct *tsk = current;
struct ring_buffer_event *event = NULL;
+ struct ring_buffer *buffer = NULL;
struct blk_io_trace *t;
unsigned long flags = 0;
unsigned long *sequence;
@@ -204,8 +207,9 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
if (blk_tracer) {
tracing_record_cmdline(current);
+ buffer = blk_tr->buffer;
pc = preempt_count();
- event = trace_buffer_lock_reserve(blk_tr, TRACE_BLK,
+ event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
sizeof(*t) + pdu_len,
0, pc);
if (!event)
@@ -252,7 +256,7 @@ record_it:
memcpy((void *) t + sizeof(*t), pdu_data, pdu_len);
if (blk_tracer) {
- trace_buffer_unlock_commit(blk_tr, event, 0, pc);
+ trace_buffer_unlock_commit(buffer, event, 0, pc);
return;
}
}
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 25edd5cc5935..8c804e24f96f 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1016,71 +1016,35 @@ static int
__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
{
unsigned long ftrace_addr;
- unsigned long ip, fl;
+ unsigned long flag = 0UL;
ftrace_addr = (unsigned long)FTRACE_ADDR;
- ip = rec->ip;
-
/*
- * If this record is not to be traced and
- * it is not enabled then do nothing.
+ * If this record is not to be traced or we want to disable it,
+ * then disable it.
*
- * If this record is not to be traced and
- * it is enabled then disable it.
+ * If we want to enable it and filtering is off, then enable it.
*
+ * If we want to enable it and filtering is on, enable it only if
+ * it's filtered
*/
- if (rec->flags & FTRACE_FL_NOTRACE) {
- if (rec->flags & FTRACE_FL_ENABLED)
- rec->flags &= ~FTRACE_FL_ENABLED;
- else
- return 0;
-
- } else if (ftrace_filtered && enable) {
- /*
- * Filtering is on:
- */
-
- fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
-
- /* Record is filtered and enabled, do nothing */
- if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
- return 0;
-
- /* Record is not filtered or enabled, do nothing */
- if (!fl)
- return 0;
-
- /* Record is not filtered but enabled, disable it */
- if (fl == FTRACE_FL_ENABLED)
- rec->flags &= ~FTRACE_FL_ENABLED;
- else
- /* Otherwise record is filtered but not enabled, enable it */
- rec->flags |= FTRACE_FL_ENABLED;
- } else {
- /* Disable or not filtered */
-
- if (enable) {
- /* if record is enabled, do nothing */
- if (rec->flags & FTRACE_FL_ENABLED)
- return 0;
-
- rec->flags |= FTRACE_FL_ENABLED;
-
- } else {
+ if (enable && !(rec->flags & FTRACE_FL_NOTRACE)) {
+ if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER))
+ flag = FTRACE_FL_ENABLED;
+ }
- /* if record is not enabled, do nothing */
- if (!(rec->flags & FTRACE_FL_ENABLED))
- return 0;
+ /* If the state of this record hasn't changed, then do nothing */
+ if ((rec->flags & FTRACE_FL_ENABLED) == flag)
+ return 0;
- rec->flags &= ~FTRACE_FL_ENABLED;
- }
+ if (flag) {
+ rec->flags |= FTRACE_FL_ENABLED;
+ return ftrace_make_call(rec, ftrace_addr);
}
- if (rec->flags & FTRACE_FL_ENABLED)
- return ftrace_make_call(rec, ftrace_addr);
- else
- return ftrace_make_nop(NULL, rec, ftrace_addr);
+ rec->flags &= ~FTRACE_FL_ENABLED;
+ return ftrace_make_nop(NULL, rec, ftrace_addr);
}
static void ftrace_replace_code(int enable)
@@ -1375,7 +1339,6 @@ struct ftrace_iterator {
unsigned flags;
unsigned char buffer[FTRACE_BUFF_MAX+1];
unsigned buffer_idx;
- unsigned filtered;
};
static void *
@@ -1438,18 +1401,13 @@ static int t_hash_show(struct seq_file *m, void *v)
{
struct ftrace_func_probe *rec;
struct hlist_node *hnd = v;
- char str[KSYM_SYMBOL_LEN];
rec = hlist_entry(hnd, struct ftrace_func_probe, node);
if (rec->ops->print)
return rec->ops->print(m, rec->ip, rec->ops, rec->data);
- kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
- seq_printf(m, "%s:", str);
-
- kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str);
- seq_printf(m, "%s", str);
+ seq_printf(m, "%pf:%pf", (void *)rec->ip, (void *)rec->ops->func);
if (rec->data)
seq_printf(m, ":%p", rec->data);
@@ -1547,7 +1505,6 @@ static int t_show(struct seq_file *m, void *v)
{
struct ftrace_iterator *iter = m->private;
struct dyn_ftrace *rec = v;
- char str[KSYM_SYMBOL_LEN];
if (iter->flags & FTRACE_ITER_HASH)
return t_hash_show(m, v);
@@ -1560,9 +1517,7 @@ static int t_show(struct seq_file *m, void *v)
if (!rec)
return 0;
- kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
-
- seq_printf(m, "%s\n", str);
+ seq_printf(m, "%pf\n", (void *)rec->ip);
return 0;
}
@@ -1601,17 +1556,6 @@ ftrace_avail_open(struct inode *inode, struct file *file)
return ret;
}
-int ftrace_avail_release(struct inode *inode, struct file *file)
-{
- struct seq_file *m = (struct seq_file *)file->private_data;
- struct ftrace_iterator *iter = m->private;
-
- seq_release(inode, file);
- kfree(iter);
-
- return 0;
-}
-
static int
ftrace_failures_open(struct inode *inode, struct file *file)
{
@@ -2317,7 +2261,6 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
}
if (isspace(ch)) {
- iter->filtered++;
iter->buffer[iter->buffer_idx] = 0;
ret = ftrace_process_regex(iter->buffer,
iter->buffer_idx, enable);
@@ -2448,7 +2391,6 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
iter = file->private_data;
if (iter->buffer_idx) {
- iter->filtered++;
iter->buffer[iter->buffer_idx] = 0;
ftrace_match_records(iter->buffer, iter->buffer_idx, enable);
}
@@ -2479,14 +2421,14 @@ static const struct file_operations ftrace_avail_fops = {
.open = ftrace_avail_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = ftrace_avail_release,
+ .release = seq_release_private,
};
static const struct file_operations ftrace_failures_fops = {
.open = ftrace_failures_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = ftrace_avail_release,
+ .release = seq_release_private,
};
static const struct file_operations ftrace_filter_fops = {
@@ -2548,7 +2490,6 @@ static void g_stop(struct seq_file *m, void *p)
static int g_show(struct seq_file *m, void *v)
{
unsigned long *ptr = v;
- char str[KSYM_SYMBOL_LEN];
if (!ptr)
return 0;
@@ -2558,9 +2499,7 @@ static int g_show(struct seq_file *m, void *v)
return 0;
}
- kallsyms_lookup(*ptr, NULL, NULL, NULL, str);
-
- seq_printf(m, "%s\n", str);
+ seq_printf(m, "%pf\n", v);
return 0;
}
diff --git a/kernel/trace/kmemtrace.c b/kernel/trace/kmemtrace.c
index 1edaa9516e81..81b1645c8549 100644
--- a/kernel/trace/kmemtrace.c
+++ b/kernel/trace/kmemtrace.c
@@ -183,11 +183,9 @@ static void kmemtrace_stop_probes(void)
static int kmem_trace_init(struct trace_array *tr)
{
- int cpu;
kmemtrace_array = tr;
- for_each_cpu(cpu, cpu_possible_mask)
- tracing_reset(tr, cpu);
+ tracing_reset_online_cpus(tr);
kmemtrace_start_probes();
@@ -239,12 +237,52 @@ struct kmemtrace_user_event_alloc {
};
static enum print_line_t
-kmemtrace_print_alloc_user(struct trace_iterator *iter,
- struct kmemtrace_alloc_entry *entry)
+kmemtrace_print_alloc(struct trace_iterator *iter, int flags)
{
- struct kmemtrace_user_event_alloc *ev_alloc;
struct trace_seq *s = &iter->seq;
+ struct kmemtrace_alloc_entry *entry;
+ int ret;
+
+ trace_assign_type(entry, iter->ent);
+
+ ret = trace_seq_printf(s, "type_id %d call_site %pF ptr %lu "
+ "bytes_req %lu bytes_alloc %lu gfp_flags %lu node %d\n",
+ entry->type_id, (void *)entry->call_site, (unsigned long)entry->ptr,
+ (unsigned long)entry->bytes_req, (unsigned long)entry->bytes_alloc,
+ (unsigned long)entry->gfp_flags, entry->node);
+
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t
+kmemtrace_print_free(struct trace_iterator *iter, int flags)
+{
+ struct trace_seq *s = &iter->seq;
+ struct kmemtrace_free_entry *entry;
+ int ret;
+
+ trace_assign_type(entry, iter->ent);
+
+ ret = trace_seq_printf(s, "type_id %d call_site %pF ptr %lu\n",
+ entry->type_id, (void *)entry->call_site,
+ (unsigned long)entry->ptr);
+
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t
+kmemtrace_print_alloc_user(struct trace_iterator *iter, int flags)
+{
+ struct trace_seq *s = &iter->seq;
+ struct kmemtrace_alloc_entry *entry;
struct kmemtrace_user_event *ev;
+ struct kmemtrace_user_event_alloc *ev_alloc;
+
+ trace_assign_type(entry, iter->ent);
ev = trace_seq_reserve(s, sizeof(*ev));
if (!ev)
@@ -271,12 +309,14 @@ kmemtrace_print_alloc_user(struct trace_iterator *iter,
}
static enum print_line_t
-kmemtrace_print_free_user(struct trace_iterator *iter,
- struct kmemtrace_free_entry *entry)
+kmemtrace_print_free_user(struct trace_iterator *iter, int flags)
{
struct trace_seq *s = &iter->seq;
+ struct kmemtrace_free_entry *entry;
struct kmemtrace_user_event *ev;
+ trace_assign_type(entry, iter->ent);
+
ev = trace_seq_reserve(s, sizeof(*ev));
if (!ev)
return TRACE_TYPE_PARTIAL_LINE;
@@ -294,12 +334,14 @@ kmemtrace_print_free_user(struct trace_iterator *iter,
/* The two other following provide a more minimalistic output */
static enum print_line_t
-kmemtrace_print_alloc_compress(struct trace_iterator *iter,
- struct kmemtrace_alloc_entry *entry)
+kmemtrace_print_alloc_compress(struct trace_iterator *iter)
{
+ struct kmemtrace_alloc_entry *entry;
struct trace_seq *s = &iter->seq;
int ret;
+ trace_assign_type(entry, iter->ent);
+
/* Alloc entry */
ret = trace_seq_printf(s, " + ");
if (!ret)
@@ -345,29 +387,24 @@ kmemtrace_print_alloc_compress(struct trace_iterator *iter,
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- /* Node */
- ret = trace_seq_printf(s, "%4d ", entry->node);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
-
- /* Call site */
- ret = seq_print_ip_sym(s, entry->call_site, 0);
+ /* Node and call site*/
+ ret = trace_seq_printf(s, "%4d %pf\n", entry->node,
+ (void *)entry->call_site);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- if (!trace_seq_printf(s, "\n"))
- return TRACE_TYPE_PARTIAL_LINE;
-
return TRACE_TYPE_HANDLED;
}
static enum print_line_t
-kmemtrace_print_free_compress(struct trace_iterator *iter,
- struct kmemtrace_free_entry *entry)
+kmemtrace_print_free_compress(struct trace_iterator *iter)
{
+ struct kmemtrace_free_entry *entry;
struct trace_seq *s = &iter->seq;
int ret;
+ trace_assign_type(entry, iter->ent);
+
/* Free entry */
ret = trace_seq_printf(s, " - ");
if (!ret)
@@ -401,19 +438,11 @@ kmemtrace_print_free_compress(struct trace_iterator *iter,
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- /* Skip node */
- ret = trace_seq_printf(s, " ");
+ /* Skip node and print call site*/
+ ret = trace_seq_printf(s, " %pf\n", (void *)entry->call_site);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- /* Call site */
- ret = seq_print_ip_sym(s, entry->call_site, 0);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
-
- if (!trace_seq_printf(s, "\n"))
- return TRACE_TYPE_PARTIAL_LINE;
-
return TRACE_TYPE_HANDLED;
}
@@ -421,32 +450,31 @@ static enum print_line_t kmemtrace_print_line(struct trace_iterator *iter)
{
struct trace_entry *entry = iter->ent;
- switch (entry->type) {
- case TRACE_KMEM_ALLOC: {
- struct kmemtrace_alloc_entry *field;
-
- trace_assign_type(field, entry);
- if (kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL)
- return kmemtrace_print_alloc_compress(iter, field);
- else
- return kmemtrace_print_alloc_user(iter, field);
- }
-
- case TRACE_KMEM_FREE: {
- struct kmemtrace_free_entry *field;
-
- trace_assign_type(field, entry);
- if (kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL)
- return kmemtrace_print_free_compress(iter, field);
- else
- return kmemtrace_print_free_user(iter, field);
- }
+ if (!(kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL))
+ return TRACE_TYPE_UNHANDLED;
+ switch (entry->type) {
+ case TRACE_KMEM_ALLOC:
+ return kmemtrace_print_alloc_compress(iter);
+ case TRACE_KMEM_FREE:
+ return kmemtrace_print_free_compress(iter);
default:
return TRACE_TYPE_UNHANDLED;
}
}
+static struct trace_event kmem_trace_alloc = {
+ .type = TRACE_KMEM_ALLOC,
+ .trace = kmemtrace_print_alloc,
+ .binary = kmemtrace_print_alloc_user,
+};
+
+static struct trace_event kmem_trace_free = {
+ .type = TRACE_KMEM_FREE,
+ .trace = kmemtrace_print_free,
+ .binary = kmemtrace_print_free_user,
+};
+
static struct tracer kmem_tracer __read_mostly = {
.name = "kmemtrace",
.init = kmem_trace_init,
@@ -463,6 +491,21 @@ void kmemtrace_init(void)
static int __init init_kmem_tracer(void)
{
- return register_tracer(&kmem_tracer);
+ if (!register_ftrace_event(&kmem_trace_alloc)) {
+ pr_warning("Warning: could not register kmem events\n");
+ return 1;
+ }
+
+ if (!register_ftrace_event(&kmem_trace_free)) {
+ pr_warning("Warning: could not register kmem events\n");
+ return 1;
+ }
+
+ if (!register_tracer(&kmem_tracer)) {
+ pr_warning("Warning: could not register the kmem tracer\n");
+ return 1;
+ }
+
+ return 0;
}
device_initcall(init_kmem_tracer);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index a330513d96ce..454e74e718cf 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -218,17 +218,12 @@ enum {
static inline int rb_null_event(struct ring_buffer_event *event)
{
- return event->type_len == RINGBUF_TYPE_PADDING
- && event->time_delta == 0;
-}
-
-static inline int rb_discarded_event(struct ring_buffer_event *event)
-{
- return event->type_len == RINGBUF_TYPE_PADDING && event->time_delta;
+ return event->type_len == RINGBUF_TYPE_PADDING && !event->time_delta;
}
static void rb_event_set_padding(struct ring_buffer_event *event)
{
+ /* padding has a NULL time_delta */
event->type_len = RINGBUF_TYPE_PADDING;
event->time_delta = 0;
}
@@ -322,6 +317,14 @@ struct buffer_data_page {
unsigned char data[]; /* data of buffer page */
};
+/*
+ * Note, the buffer_page list must be first. The buffer pages
+ * are allocated in cache lines, which means that each buffer
+ * page will be at the beginning of a cache line, and thus
+ * the least significant bits will be zero. We use this to
+ * add flags in the list struct pointers, to make the ring buffer
+ * lockless.
+ */
struct buffer_page {
struct list_head list; /* list of buffer pages */
local_t write; /* index for next write */
@@ -330,6 +333,21 @@ struct buffer_page {
struct buffer_data_page *page; /* Actual data page */
};
+/*
+ * The buffer page counters, write and entries, must be reset
+ * atomically when crossing page boundaries. To synchronize this
+ * update, two counters are inserted into the number. One is
+ * the actual counter for the write position or count on the page.
+ *
+ * The other is a counter of updaters. Before an update happens
+ * the update partition of the counter is incremented. This will
+ * allow the updater to update the counter atomically.
+ *
+ * The counter is 20 bits, and the state data is 12.
+ */
+#define RB_WRITE_MASK 0xfffff
+#define RB_WRITE_INTCNT (1 << 20)
+
static void rb_init_page(struct buffer_data_page *bpage)
{
local_set(&bpage->commit, 0);
@@ -403,21 +421,20 @@ int ring_buffer_print_page_header(struct trace_seq *s)
struct ring_buffer_per_cpu {
int cpu;
struct ring_buffer *buffer;
- spinlock_t reader_lock; /* serialize readers */
+ spinlock_t reader_lock; /* serialize readers */
raw_spinlock_t lock;
struct lock_class_key lock_key;
- struct list_head pages;
+ struct list_head *pages;
struct buffer_page *head_page; /* read from head */
struct buffer_page *tail_page; /* write to tail */
struct buffer_page *commit_page; /* committed pages */
struct buffer_page *reader_page;
- unsigned long nmi_dropped;
- unsigned long commit_overrun;
- unsigned long overrun;
- unsigned long read;
+ local_t commit_overrun;
+ local_t overrun;
local_t entries;
local_t committing;
local_t commits;
+ unsigned long read;
u64 write_stamp;
u64 read_stamp;
atomic_t record_disabled;
@@ -450,14 +467,19 @@ struct ring_buffer_iter {
};
/* buffer may be either ring_buffer or ring_buffer_per_cpu */
-#define RB_WARN_ON(buffer, cond) \
- ({ \
- int _____ret = unlikely(cond); \
- if (_____ret) { \
- atomic_inc(&buffer->record_disabled); \
- WARN_ON(1); \
- } \
- _____ret; \
+#define RB_WARN_ON(b, cond) \
+ ({ \
+ int _____ret = unlikely(cond); \
+ if (_____ret) { \
+ if (__same_type(*(b), struct ring_buffer_per_cpu)) { \
+ struct ring_buffer_per_cpu *__b = \
+ (void *)b; \
+ atomic_inc(&__b->buffer->record_disabled); \
+ } else \
+ atomic_inc(&b->record_disabled); \
+ WARN_ON(1); \
+ } \
+ _____ret; \
})
/* Up this if you want to test the TIME_EXTENTS and normalization */
@@ -489,6 +511,390 @@ void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer,
}
EXPORT_SYMBOL_GPL(ring_buffer_normalize_time_stamp);
+/*
+ * Making the ring buffer lockless makes things tricky.
+ * Although writes only happen on the CPU that they are on,
+ * and they only need to worry about interrupts. Reads can
+ * happen on any CPU.
+ *
+ * The reader page is always off the ring buffer, but when the
+ * reader finishes with a page, it needs to swap its page with
+ * a new one from the buffer. The reader needs to take from
+ * the head (writes go to the tail). But if a writer is in overwrite
+ * mode and wraps, it must push the head page forward.
+ *
+ * Here lies the problem.
+ *
+ * The reader must be careful to replace only the head page, and
+ * not another one. As described at the top of the file in the
+ * ASCII art, the reader sets its old page to point to the next
+ * page after head. It then sets the page after head to point to
+ * the old reader page. But if the writer moves the head page
+ * during this operation, the reader could end up with the tail.
+ *
+ * We use cmpxchg to help prevent this race. We also do something
+ * special with the page before head. We set the LSB to 1.
+ *
+ * When the writer must push the page forward, it will clear the
+ * bit that points to the head page, move the head, and then set
+ * the bit that points to the new head page.
+ *
+ * We also don't want an interrupt coming in and moving the head
+ * page on another writer. Thus we use the second LSB to catch
+ * that too. Thus:
+ *
+ * head->list->prev->next bit 1 bit 0
+ * ------- -------
+ * Normal page 0 0
+ * Points to head page 0 1
+ * New head page 1 0
+ *
+ * Note we can not trust the prev pointer of the head page, because:
+ *
+ * +----+ +-----+ +-----+
+ * | |------>| T |---X--->| N |
+ * | |<------| | | |
+ * +----+ +-----+ +-----+
+ * ^ ^ |
+ * | +-----+ | |
+ * +----------| R |----------+ |
+ * | |<-----------+
+ * +-----+
+ *
+ * Key: ---X--> HEAD flag set in pointer
+ * T Tail page
+ * R Reader page
+ * N Next page
+ *
+ * (see __rb_reserve_next() to see where this happens)
+ *
+ * What the above shows is that the reader just swapped out
+ * the reader page with a page in the buffer, but before it
+ * could make the new header point back to the new page added
+ * it was preempted by a writer. The writer moved forward onto
+ * the new page added by the reader and is about to move forward
+ * again.
+ *
+ * You can see, it is legitimate for the previous pointer of
+ * the head (or any page) not to point back to itself. But only
+ * temporarially.
+ */
+
+#define RB_PAGE_NORMAL 0UL
+#define RB_PAGE_HEAD 1UL
+#define RB_PAGE_UPDATE 2UL
+
+
+#define RB_FLAG_MASK 3UL
+
+/* PAGE_MOVED is not part of the mask */
+#define RB_PAGE_MOVED 4UL
+
+/*
+ * rb_list_head - remove any bit
+ */
+static struct list_head *rb_list_head(struct list_head *list)
+{
+ unsigned long val = (unsigned long)list;
+
+ return (struct list_head *)(val & ~RB_FLAG_MASK);
+}
+
+/*
+ * rb_is_head_page - test if the give page is the head page
+ *
+ * Because the reader may move the head_page pointer, we can
+ * not trust what the head page is (it may be pointing to
+ * the reader page). But if the next page is a header page,
+ * its flags will be non zero.
+ */
+static int inline
+rb_is_head_page(struct ring_buffer_per_cpu *cpu_buffer,
+ struct buffer_page *page, struct list_head *list)
+{
+ unsigned long val;
+
+ val = (unsigned long)list->next;
+
+ if ((val & ~RB_FLAG_MASK) != (unsigned long)&page->list)
+ return RB_PAGE_MOVED;
+
+ return val & RB_FLAG_MASK;
+}
+
+/*
+ * rb_is_reader_page
+ *
+ * The unique thing about the reader page, is that, if the
+ * writer is ever on it, the previous pointer never points
+ * back to the reader page.
+ */
+static int rb_is_reader_page(struct buffer_page *page)
+{
+ struct list_head *list = page->list.prev;
+
+ return rb_list_head(list->next) != &page->list;
+}
+
+/*
+ * rb_set_list_to_head - set a list_head to be pointing to head.
+ */
+static void rb_set_list_to_head(struct ring_buffer_per_cpu *cpu_buffer,
+ struct list_head *list)
+{
+ unsigned long *ptr;
+
+ ptr = (unsigned long *)&list->next;
+ *ptr |= RB_PAGE_HEAD;
+ *ptr &= ~RB_PAGE_UPDATE;
+}
+
+/*
+ * rb_head_page_activate - sets up head page
+ */
+static void rb_head_page_activate(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ struct buffer_page *head;
+
+ head = cpu_buffer->head_page;
+ if (!head)
+ return;
+
+ /*
+ * Set the previous list pointer to have the HEAD flag.
+ */
+ rb_set_list_to_head(cpu_buffer, head->list.prev);
+}
+
+static void rb_list_head_clear(struct list_head *list)
+{
+ unsigned long *ptr = (unsigned long *)&list->next;
+
+ *ptr &= ~RB_FLAG_MASK;
+}
+
+/*
+ * rb_head_page_dactivate - clears head page ptr (for free list)
+ */
+static void
+rb_head_page_deactivate(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ struct list_head *hd;
+
+ /* Go through the whole list and clear any pointers found. */
+ rb_list_head_clear(cpu_buffer->pages);
+
+ list_for_each(hd, cpu_buffer->pages)
+ rb_list_head_clear(hd);
+}
+
+static int rb_head_page_set(struct ring_buffer_per_cpu *cpu_buffer,
+ struct buffer_page *head,
+ struct buffer_page *prev,
+ int old_flag, int new_flag)
+{
+ struct list_head *list;
+ unsigned long val = (unsigned long)&head->list;
+ unsigned long ret;
+
+ list = &prev->list;
+
+ val &= ~RB_FLAG_MASK;
+
+ ret = (unsigned long)cmpxchg(&list->next,
+ val | old_flag, val | new_flag);
+
+ /* check if the reader took the page */
+ if ((ret & ~RB_FLAG_MASK) != val)
+ return RB_PAGE_MOVED;
+
+ return ret & RB_FLAG_MASK;
+}
+
+static int rb_head_page_set_update(struct ring_buffer_per_cpu *cpu_buffer,
+ struct buffer_page *head,
+ struct buffer_page *prev,
+ int old_flag)
+{
+ return rb_head_page_set(cpu_buffer, head, prev,
+ old_flag, RB_PAGE_UPDATE);
+}
+
+static int rb_head_page_set_head(struct ring_buffer_per_cpu *cpu_buffer,
+ struct buffer_page *head,
+ struct buffer_page *prev,
+ int old_flag)
+{
+ return rb_head_page_set(cpu_buffer, head, prev,
+ old_flag, RB_PAGE_HEAD);
+}
+
+static int rb_head_page_set_normal(struct ring_buffer_per_cpu *cpu_buffer,
+ struct buffer_page *head,
+ struct buffer_page *prev,
+ int old_flag)
+{
+ return rb_head_page_set(cpu_buffer, head, prev,
+ old_flag, RB_PAGE_NORMAL);
+}
+
+static inline void rb_inc_page(struct ring_buffer_per_cpu *cpu_buffer,
+ struct buffer_page **bpage)
+{
+ struct list_head *p = rb_list_head((*bpage)->list.next);
+
+ *bpage = list_entry(p, struct buffer_page, list);
+}
+
+static struct buffer_page *
+rb_set_head_page(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ struct buffer_page *head;
+ struct buffer_page *page;
+ struct list_head *list;
+ int i;
+
+ if (RB_WARN_ON(cpu_buffer, !cpu_buffer->head_page))
+ return NULL;
+
+ /* sanity check */
+ list = cpu_buffer->pages;
+ if (RB_WARN_ON(cpu_buffer, rb_list_head(list->prev->next) != list))
+ return NULL;
+
+ page = head = cpu_buffer->head_page;
+ /*
+ * It is possible that the writer moves the header behind
+ * where we started, and we miss in one loop.
+ * A second loop should grab the header, but we'll do
+ * three loops just because I'm paranoid.
+ */
+ for (i = 0; i < 3; i++) {
+ do {
+ if (rb_is_head_page(cpu_buffer, page, page->list.prev)) {
+ cpu_buffer->head_page = page;
+ return page;
+ }
+ rb_inc_page(cpu_buffer, &page);
+ } while (page != head);
+ }
+
+ RB_WARN_ON(cpu_buffer, 1);
+
+ return NULL;
+}
+
+static int rb_head_page_replace(struct buffer_page *old,
+ struct buffer_page *new)
+{
+ unsigned long *ptr = (unsigned long *)&old->list.prev->next;
+ unsigned long val;
+ unsigned long ret;
+
+ val = *ptr & ~RB_FLAG_MASK;
+ val |= RB_PAGE_HEAD;
+
+ ret = cmpxchg(ptr, val, &new->list);
+
+ return ret == val;
+}
+
+/*
+ * rb_tail_page_update - move the tail page forward
+ *
+ * Returns 1 if moved tail page, 0 if someone else did.
+ */
+static int rb_tail_page_update(struct ring_buffer_per_cpu *cpu_buffer,
+ struct buffer_page *tail_page,
+ struct buffer_page *next_page)
+{
+ struct buffer_page *old_tail;
+ unsigned long old_entries;
+ unsigned long old_write;
+ int ret = 0;
+
+ /*
+ * The tail page now needs to be moved forward.
+ *
+ * We need to reset the tail page, but without messing
+ * with possible erasing of data brought in by interrupts
+ * that have moved the tail page and are currently on it.
+ *
+ * We add a counter to the write field to denote this.
+ */
+ old_write = local_add_return(RB_WRITE_INTCNT, &next_page->write);
+ old_entries = local_add_return(RB_WRITE_INTCNT, &next_page->entries);
+
+ /*
+ * Just make sure we have seen our old_write and synchronize
+ * with any interrupts that come in.
+ */
+ barrier();
+
+ /*
+ * If the tail page is still the same as what we think
+ * it is, then it is up to us to update the tail
+ * pointer.
+ */
+ if (tail_page == cpu_buffer->tail_page) {
+ /* Zero the write counter */
+ unsigned long val = old_write & ~RB_WRITE_MASK;
+ unsigned long eval = old_entries & ~RB_WRITE_MASK;
+
+ /*
+ * This will only succeed if an interrupt did
+ * not come in and change it. In which case, we
+ * do not want to modify it.
+ *
+ * We add (void) to let the compiler know that we do not care
+ * about the return value of these functions. We use the
+ * cmpxchg to only update if an interrupt did not already
+ * do it for us. If the cmpxchg fails, we don't care.
+ */
+ (void)local_cmpxchg(&next_page->write, old_write, val);
+ (void)local_cmpxchg(&next_page->entries, old_entries, eval);
+
+ /*
+ * No need to worry about races with clearing out the commit.
+ * it only can increment when a commit takes place. But that
+ * only happens in the outer most nested commit.
+ */
+ local_set(&next_page->page->commit, 0);
+
+ old_tail = cmpxchg(&cpu_buffer->tail_page,
+ tail_page, next_page);
+
+ if (old_tail == tail_page)
+ ret = 1;
+ }
+
+ return ret;
+}
+
+static int rb_check_bpage(struct ring_buffer_per_cpu *cpu_buffer,
+ struct buffer_page *bpage)
+{
+ unsigned long val = (unsigned long)bpage;
+
+ if (RB_WARN_ON(cpu_buffer, val & RB_FLAG_MASK))
+ return 1;
+
+ return 0;
+}
+
+/**
+ * rb_check_list - make sure a pointer to a list has the last bits zero
+ */
+static int rb_check_list(struct ring_buffer_per_cpu *cpu_buffer,
+ struct list_head *list)
+{
+ if (RB_WARN_ON(cpu_buffer, rb_list_head(list->prev) != list->prev))
+ return 1;
+ if (RB_WARN_ON(cpu_buffer, rb_list_head(list->next) != list->next))
+ return 1;
+ return 0;
+}
+
/**
* check_pages - integrity check of buffer pages
* @cpu_buffer: CPU buffer with pages to test
@@ -498,14 +904,19 @@ EXPORT_SYMBOL_GPL(ring_buffer_normalize_time_stamp);
*/
static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer)
{
- struct list_head *head = &cpu_buffer->pages;
+ struct list_head *head = cpu_buffer->pages;
struct buffer_page *bpage, *tmp;
+ rb_head_page_deactivate(cpu_buffer);
+
if (RB_WARN_ON(cpu_buffer, head->next->prev != head))
return -1;
if (RB_WARN_ON(cpu_buffer, head->prev->next != head))
return -1;
+ if (rb_check_list(cpu_buffer, head))
+ return -1;
+
list_for_each_entry_safe(bpage, tmp, head, list) {
if (RB_WARN_ON(cpu_buffer,
bpage->list.next->prev != &bpage->list))
@@ -513,25 +924,33 @@ static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer)
if (RB_WARN_ON(cpu_buffer,
bpage->list.prev->next != &bpage->list))
return -1;
+ if (rb_check_list(cpu_buffer, &bpage->list))
+ return -1;
}
+ rb_head_page_activate(cpu_buffer);
+
return 0;
}
static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
unsigned nr_pages)
{
- struct list_head *head = &cpu_buffer->pages;
struct buffer_page *bpage, *tmp;
unsigned long addr;
LIST_HEAD(pages);
unsigned i;
+ WARN_ON(!nr_pages);
+
for (i = 0; i < nr_pages; i++) {
bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()),
GFP_KERNEL, cpu_to_node(cpu_buffer->cpu));
if (!bpage)
goto free_pages;
+
+ rb_check_bpage(cpu_buffer, bpage);
+
list_add(&bpage->list, &pages);
addr = __get_free_page(GFP_KERNEL);
@@ -541,7 +960,13 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
rb_init_page(bpage->page);
}
- list_splice(&pages, head);
+ /*
+ * The ring buffer page list is a circular list that does not
+ * start and end with a list head. All page list items point to
+ * other pages.
+ */
+ cpu_buffer->pages = pages.next;
+ list_del(&pages);
rb_check_pages(cpu_buffer);
@@ -573,13 +998,14 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
spin_lock_init(&cpu_buffer->reader_lock);
lockdep_set_class(&cpu_buffer->reader_lock, buffer->reader_lock_key);
cpu_buffer->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
- INIT_LIST_HEAD(&cpu_buffer->pages);
bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()),
GFP_KERNEL, cpu_to_node(cpu));
if (!bpage)
goto fail_free_buffer;
+ rb_check_bpage(cpu_buffer, bpage);
+
cpu_buffer->reader_page = bpage;
addr = __get_free_page(GFP_KERNEL);
if (!addr)
@@ -594,9 +1020,11 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
goto fail_free_reader;
cpu_buffer->head_page
- = list_entry(cpu_buffer->pages.next, struct buffer_page, list);
+ = list_entry(cpu_buffer->pages, struct buffer_page, list);
cpu_buffer->tail_page = cpu_buffer->commit_page = cpu_buffer->head_page;
+ rb_head_page_activate(cpu_buffer);
+
return cpu_buffer;
fail_free_reader:
@@ -609,15 +1037,22 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer)
{
- struct list_head *head = &cpu_buffer->pages;
+ struct list_head *head = cpu_buffer->pages;
struct buffer_page *bpage, *tmp;
free_buffer_page(cpu_buffer->reader_page);
- list_for_each_entry_safe(bpage, tmp, head, list) {
- list_del_init(&bpage->list);
+ rb_head_page_deactivate(cpu_buffer);
+
+ if (head) {
+ list_for_each_entry_safe(bpage, tmp, head, list) {
+ list_del_init(&bpage->list);
+ free_buffer_page(bpage);
+ }
+ bpage = list_entry(head, struct buffer_page, list);
free_buffer_page(bpage);
}
+
kfree(cpu_buffer);
}
@@ -760,15 +1195,17 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
atomic_inc(&cpu_buffer->record_disabled);
synchronize_sched();
+ rb_head_page_deactivate(cpu_buffer);
+
for (i = 0; i < nr_pages; i++) {
- if (RB_WARN_ON(cpu_buffer, list_empty(&cpu_buffer->pages)))
+ if (RB_WARN_ON(cpu_buffer, list_empty(cpu_buffer->pages)))
return;
- p = cpu_buffer->pages.next;
+ p = cpu_buffer->pages->next;
bpage = list_entry(p, struct buffer_page, list);
list_del_init(&bpage->list);
free_buffer_page(bpage);
}
- if (RB_WARN_ON(cpu_buffer, list_empty(&cpu_buffer->pages)))
+ if (RB_WARN_ON(cpu_buffer, list_empty(cpu_buffer->pages)))
return;
rb_reset_cpu(cpu_buffer);
@@ -790,15 +1227,19 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
atomic_inc(&cpu_buffer->record_disabled);
synchronize_sched();
+ spin_lock_irq(&cpu_buffer->reader_lock);
+ rb_head_page_deactivate(cpu_buffer);
+
for (i = 0; i < nr_pages; i++) {
if (RB_WARN_ON(cpu_buffer, list_empty(pages)))
return;
p = pages->next;
bpage = list_entry(p, struct buffer_page, list);
list_del_init(&bpage->list);
- list_add_tail(&bpage->list, &cpu_buffer->pages);
+ list_add_tail(&bpage->list, cpu_buffer->pages);
}
rb_reset_cpu(cpu_buffer);
+ spin_unlock_irq(&cpu_buffer->reader_lock);
rb_check_pages(cpu_buffer);
@@ -949,21 +1390,14 @@ rb_reader_event(struct ring_buffer_per_cpu *cpu_buffer)
}
static inline struct ring_buffer_event *
-rb_head_event(struct ring_buffer_per_cpu *cpu_buffer)
-{
- return __rb_page_index(cpu_buffer->head_page,
- cpu_buffer->head_page->read);
-}
-
-static inline struct ring_buffer_event *
rb_iter_head_event(struct ring_buffer_iter *iter)
{
return __rb_page_index(iter->head_page, iter->head);
}
-static inline unsigned rb_page_write(struct buffer_page *bpage)
+static inline unsigned long rb_page_write(struct buffer_page *bpage)
{
- return local_read(&bpage->write);
+ return local_read(&bpage->write) & RB_WRITE_MASK;
}
static inline unsigned rb_page_commit(struct buffer_page *bpage)
@@ -971,6 +1405,11 @@ static inline unsigned rb_page_commit(struct buffer_page *bpage)
return local_read(&bpage->page->commit);
}
+static inline unsigned long rb_page_entries(struct buffer_page *bpage)
+{
+ return local_read(&bpage->entries) & RB_WRITE_MASK;
+}
+
/* Size is determined by what has been commited */
static inline unsigned rb_page_size(struct buffer_page *bpage)
{
@@ -983,22 +1422,6 @@ rb_commit_index(struct ring_buffer_per_cpu *cpu_buffer)
return rb_page_commit(cpu_buffer->commit_page);
}
-static inline unsigned rb_head_size(struct ring_buffer_per_cpu *cpu_buffer)
-{
- return rb_page_commit(cpu_buffer->head_page);
-}
-
-static inline void rb_inc_page(struct ring_buffer_per_cpu *cpu_buffer,
- struct buffer_page **bpage)
-{
- struct list_head *p = (*bpage)->list.next;
-
- if (p == &cpu_buffer->pages)
- p = p->next;
-
- *bpage = list_entry(p, struct buffer_page, list);
-}
-
static inline unsigned
rb_event_index(struct ring_buffer_event *event)
{
@@ -1024,6 +1447,8 @@ rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
static void
rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
{
+ unsigned long max_count;
+
/*
* We only race with interrupts and NMIs on this CPU.
* If we own the commit event, then we can commit
@@ -1033,9 +1458,16 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
* assign the commit to the tail.
*/
again:
+ max_count = cpu_buffer->buffer->pages * 100;
+
while (cpu_buffer->commit_page != cpu_buffer->tail_page) {
- cpu_buffer->commit_page->page->commit =
- cpu_buffer->commit_page->write;
+ if (RB_WARN_ON(cpu_buffer, !(--max_count)))
+ return;
+ if (RB_WARN_ON(cpu_buffer,
+ rb_is_reader_page(cpu_buffer->tail_page)))
+ return;
+ local_set(&cpu_buffer->commit_page->page->commit,
+ rb_page_write(cpu_buffer->commit_page));
rb_inc_page(cpu_buffer, &cpu_buffer->commit_page);
cpu_buffer->write_stamp =
cpu_buffer->commit_page->page->time_stamp;
@@ -1044,8 +1476,12 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
}
while (rb_commit_index(cpu_buffer) !=
rb_page_write(cpu_buffer->commit_page)) {
- cpu_buffer->commit_page->page->commit =
- cpu_buffer->commit_page->write;
+
+ local_set(&cpu_buffer->commit_page->page->commit,
+ rb_page_write(cpu_buffer->commit_page));
+ RB_WARN_ON(cpu_buffer,
+ local_read(&cpu_buffer->commit_page->page->commit) &
+ ~RB_WRITE_MASK);
barrier();
}
@@ -1078,7 +1514,7 @@ static void rb_inc_iter(struct ring_buffer_iter *iter)
* to the head page instead of next.
*/
if (iter->head_page == cpu_buffer->reader_page)
- iter->head_page = cpu_buffer->head_page;
+ iter->head_page = rb_set_head_page(cpu_buffer);
else
rb_inc_page(cpu_buffer, &iter->head_page);
@@ -1122,6 +1558,163 @@ rb_update_event(struct ring_buffer_event *event,
}
}
+/*
+ * rb_handle_head_page - writer hit the head page
+ *
+ * Returns: +1 to retry page
+ * 0 to continue
+ * -1 on error
+ */
+static int
+rb_handle_head_page(struct ring_buffer_per_cpu *cpu_buffer,
+ struct buffer_page *tail_page,
+ struct buffer_page *next_page)
+{
+ struct buffer_page *new_head;
+ int entries;
+ int type;
+ int ret;
+
+ entries = rb_page_entries(next_page);
+
+ /*
+ * The hard part is here. We need to move the head
+ * forward, and protect against both readers on
+ * other CPUs and writers coming in via interrupts.
+ */
+ type = rb_head_page_set_update(cpu_buffer, next_page, tail_page,
+ RB_PAGE_HEAD);
+
+ /*
+ * type can be one of four:
+ * NORMAL - an interrupt already moved it for us
+ * HEAD - we are the first to get here.
+ * UPDATE - we are the interrupt interrupting
+ * a current move.
+ * MOVED - a reader on another CPU moved the next
+ * pointer to its reader page. Give up
+ * and try again.
+ */
+
+ switch (type) {
+ case RB_PAGE_HEAD:
+ /*
+ * We changed the head to UPDATE, thus
+ * it is our responsibility to update
+ * the counters.
+ */
+ local_add(entries, &cpu_buffer->overrun);
+
+ /*
+ * The entries will be zeroed out when we move the
+ * tail page.
+ */
+
+ /* still more to do */
+ break;
+
+ case RB_PAGE_UPDATE:
+ /*
+ * This is an interrupt that interrupt the
+ * previous update. Still more to do.
+ */
+ break;
+ case RB_PAGE_NORMAL:
+ /*
+ * An interrupt came in before the update
+ * and processed this for us.
+ * Nothing left to do.
+ */
+ return 1;
+ case RB_PAGE_MOVED:
+ /*
+ * The reader is on another CPU and just did
+ * a swap with our next_page.
+ * Try again.
+ */
+ return 1;
+ default:
+ RB_WARN_ON(cpu_buffer, 1); /* WTF??? */
+ return -1;
+ }
+
+ /*
+ * Now that we are here, the old head pointer is
+ * set to UPDATE. This will keep the reader from
+ * swapping the head page with the reader page.
+ * The reader (on another CPU) will spin till
+ * we are finished.
+ *
+ * We just need to protect against interrupts
+ * doing the job. We will set the next pointer
+ * to HEAD. After that, we set the old pointer
+ * to NORMAL, but only if it was HEAD before.
+ * otherwise we are an interrupt, and only
+ * want the outer most commit to reset it.
+ */
+ new_head = next_page;
+ rb_inc_page(cpu_buffer, &new_head);
+
+ ret = rb_head_page_set_head(cpu_buffer, new_head, next_page,
+ RB_PAGE_NORMAL);
+
+ /*
+ * Valid returns are:
+ * HEAD - an interrupt came in and already set it.
+ * NORMAL - One of two things:
+ * 1) We really set it.
+ * 2) A bunch of interrupts came in and moved
+ * the page forward again.
+ */
+ switch (ret) {
+ case RB_PAGE_HEAD:
+ case RB_PAGE_NORMAL:
+ /* OK */
+ break;
+ default:
+ RB_WARN_ON(cpu_buffer, 1);
+ return -1;
+ }
+
+ /*
+ * It is possible that an interrupt came in,
+ * set the head up, then more interrupts came in
+ * and moved it again. When we get back here,
+ * the page would have been set to NORMAL but we
+ * just set it back to HEAD.
+ *
+ * How do you detect this? Well, if that happened
+ * the tail page would have moved.
+ */
+ if (ret == RB_PAGE_NORMAL) {
+ /*
+ * If the tail had moved passed next, then we need
+ * to reset the pointer.
+ */
+ if (cpu_buffer->tail_page != tail_page &&
+ cpu_buffer->tail_page != next_page)
+ rb_head_page_set_normal(cpu_buffer, new_head,
+ next_page,
+ RB_PAGE_HEAD);
+ }
+
+ /*
+ * If this was the outer most commit (the one that
+ * changed the original pointer from HEAD to UPDATE),
+ * then it is up to us to reset it to NORMAL.
+ */
+ if (type == RB_PAGE_HEAD) {
+ ret = rb_head_page_set_normal(cpu_buffer, next_page,
+ tail_page,
+ RB_PAGE_UPDATE);
+ if (RB_WARN_ON(cpu_buffer,
+ ret != RB_PAGE_UPDATE))
+ return -1;
+ }
+
+ return 0;
+}
+
static unsigned rb_calculate_event_length(unsigned length)
{
struct ring_buffer_event event; /* Used only for sizeof array */
@@ -1185,9 +1778,6 @@ rb_reset_tail(struct ring_buffer_per_cpu *cpu_buffer,
event->type_len = RINGBUF_TYPE_PADDING;
/* time delta must be non zero */
event->time_delta = 1;
- /* Account for this as an entry */
- local_inc(&tail_page->entries);
- local_inc(&cpu_buffer->entries);
/* Set write to end of buffer */
length = (tail + length) - BUF_PAGE_SIZE;
@@ -1200,96 +1790,93 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
struct buffer_page *commit_page,
struct buffer_page *tail_page, u64 *ts)
{
- struct buffer_page *next_page, *head_page, *reader_page;
struct ring_buffer *buffer = cpu_buffer->buffer;
- bool lock_taken = false;
- unsigned long flags;
+ struct buffer_page *next_page;
+ int ret;
next_page = tail_page;
- local_irq_save(flags);
- /*
- * Since the write to the buffer is still not
- * fully lockless, we must be careful with NMIs.
- * The locks in the writers are taken when a write
- * crosses to a new page. The locks protect against
- * races with the readers (this will soon be fixed
- * with a lockless solution).
- *
- * Because we can not protect against NMIs, and we
- * want to keep traces reentrant, we need to manage
- * what happens when we are in an NMI.
- *
- * NMIs can happen after we take the lock.
- * If we are in an NMI, only take the lock
- * if it is not already taken. Otherwise
- * simply fail.
- */
- if (unlikely(in_nmi())) {
- if (!__raw_spin_trylock(&cpu_buffer->lock)) {
- cpu_buffer->nmi_dropped++;
- goto out_reset;
- }
- } else
- __raw_spin_lock(&cpu_buffer->lock);
-
- lock_taken = true;
-
rb_inc_page(cpu_buffer, &next_page);
- head_page = cpu_buffer->head_page;
- reader_page = cpu_buffer->reader_page;
-
- /* we grabbed the lock before incrementing */
- if (RB_WARN_ON(cpu_buffer, next_page == reader_page))
- goto out_reset;
-
/*
* If for some reason, we had an interrupt storm that made
* it all the way around the buffer, bail, and warn
* about it.
*/
if (unlikely(next_page == commit_page)) {
- cpu_buffer->commit_overrun++;
+ local_inc(&cpu_buffer->commit_overrun);
goto out_reset;
}
- if (next_page == head_page) {
- if (!(buffer->flags & RB_FL_OVERWRITE))
- goto out_reset;
-
- /* tail_page has not moved yet? */
- if (tail_page == cpu_buffer->tail_page) {
- /* count overflows */
- cpu_buffer->overrun +=
- local_read(&head_page->entries);
+ /*
+ * This is where the fun begins!
+ *
+ * We are fighting against races between a reader that
+ * could be on another CPU trying to swap its reader
+ * page with the buffer head.
+ *
+ * We are also fighting against interrupts coming in and
+ * moving the head or tail on us as well.
+ *
+ * If the next page is the head page then we have filled
+ * the buffer, unless the commit page is still on the
+ * reader page.
+ */
+ if (rb_is_head_page(cpu_buffer, next_page, &tail_page->list)) {
- rb_inc_page(cpu_buffer, &head_page);
- cpu_buffer->head_page = head_page;
- cpu_buffer->head_page->read = 0;
+ /*
+ * If the commit is not on the reader page, then
+ * move the header page.
+ */
+ if (!rb_is_reader_page(cpu_buffer->commit_page)) {
+ /*
+ * If we are not in overwrite mode,
+ * this is easy, just stop here.
+ */
+ if (!(buffer->flags & RB_FL_OVERWRITE))
+ goto out_reset;
+
+ ret = rb_handle_head_page(cpu_buffer,
+ tail_page,
+ next_page);
+ if (ret < 0)
+ goto out_reset;
+ if (ret)
+ goto out_again;
+ } else {
+ /*
+ * We need to be careful here too. The
+ * commit page could still be on the reader
+ * page. We could have a small buffer, and
+ * have filled up the buffer with events
+ * from interrupts and such, and wrapped.
+ *
+ * Note, if the tail page is also the on the
+ * reader_page, we let it move out.
+ */
+ if (unlikely((cpu_buffer->commit_page !=
+ cpu_buffer->tail_page) &&
+ (cpu_buffer->commit_page ==
+ cpu_buffer->reader_page))) {
+ local_inc(&cpu_buffer->commit_overrun);
+ goto out_reset;
+ }
}
}
- /*
- * If the tail page is still the same as what we think
- * it is, then it is up to us to update the tail
- * pointer.
- */
- if (tail_page == cpu_buffer->tail_page) {
- local_set(&next_page->write, 0);
- local_set(&next_page->entries, 0);
- local_set(&next_page->page->commit, 0);
- cpu_buffer->tail_page = next_page;
-
- /* reread the time stamp */
+ ret = rb_tail_page_update(cpu_buffer, tail_page, next_page);
+ if (ret) {
+ /*
+ * Nested commits always have zero deltas, so
+ * just reread the time stamp
+ */
*ts = rb_time_stamp(buffer, cpu_buffer->cpu);
- cpu_buffer->tail_page->page->time_stamp = *ts;
+ next_page->page->time_stamp = *ts;
}
- rb_reset_tail(cpu_buffer, tail_page, tail, length);
+ out_again:
- __raw_spin_unlock(&cpu_buffer->lock);
- local_irq_restore(flags);
+ rb_reset_tail(cpu_buffer, tail_page, tail, length);
/* fail and let the caller try again */
return ERR_PTR(-EAGAIN);
@@ -1298,9 +1885,6 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
/* reset write */
rb_reset_tail(cpu_buffer, tail_page, tail, length);
- if (likely(lock_taken))
- __raw_spin_unlock(&cpu_buffer->lock);
- local_irq_restore(flags);
return NULL;
}
@@ -1317,6 +1901,9 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
barrier();
tail_page = cpu_buffer->tail_page;
write = local_add_return(length, &tail_page->write);
+
+ /* set write to only the index of the write */
+ write &= RB_WRITE_MASK;
tail = write - length;
/* See if we shot pass the end of this buffer page */
@@ -1361,12 +1948,16 @@ rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer,
bpage = cpu_buffer->tail_page;
if (bpage->page == (void *)addr && rb_page_write(bpage) == old_index) {
+ unsigned long write_mask =
+ local_read(&bpage->write) & ~RB_WRITE_MASK;
/*
* This is on the tail page. It is possible that
* a write could come in and move the tail page
* and write to the next page. That is fine
* because we just shorten what is on this page.
*/
+ old_index += write_mask;
+ new_index += write_mask;
index = local_cmpxchg(&bpage->write, old_index, new_index);
if (index == old_index)
return 1;
@@ -1482,7 +2073,8 @@ static void rb_end_commit(struct ring_buffer_per_cpu *cpu_buffer)
}
static struct ring_buffer_event *
-rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer,
+rb_reserve_next_event(struct ring_buffer *buffer,
+ struct ring_buffer_per_cpu *cpu_buffer,
unsigned long length)
{
struct ring_buffer_event *event;
@@ -1492,6 +2084,21 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer,
rb_start_commit(cpu_buffer);
+#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP
+ /*
+ * Due to the ability to swap a cpu buffer from a buffer
+ * it is possible it was swapped before we committed.
+ * (committing stops a swap). We check for it here and
+ * if it happened, we have to fail the write.
+ */
+ barrier();
+ if (unlikely(ACCESS_ONCE(cpu_buffer->buffer) != buffer)) {
+ local_dec(&cpu_buffer->committing);
+ local_dec(&cpu_buffer->commits);
+ return NULL;
+ }
+#endif
+
length = rb_calculate_event_length(length);
again:
/*
@@ -1652,7 +2259,7 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer, unsigned long length)
if (length > BUF_MAX_DATA_SIZE)
goto out;
- event = rb_reserve_next_event(cpu_buffer, length);
+ event = rb_reserve_next_event(buffer, cpu_buffer, length);
if (!event)
goto out;
@@ -1675,18 +2282,23 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer, unsigned long length)
}
EXPORT_SYMBOL_GPL(ring_buffer_lock_reserve);
-static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer,
+static void
+rb_update_write_stamp(struct ring_buffer_per_cpu *cpu_buffer,
struct ring_buffer_event *event)
{
- local_inc(&cpu_buffer->entries);
-
/*
* The event first in the commit queue updates the
* time stamp.
*/
if (rb_event_is_commit(cpu_buffer, event))
cpu_buffer->write_stamp += event->time_delta;
+}
+static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer,
+ struct ring_buffer_event *event)
+{
+ local_inc(&cpu_buffer->entries);
+ rb_update_write_stamp(cpu_buffer, event);
rb_end_commit(cpu_buffer);
}
@@ -1733,32 +2345,57 @@ static inline void rb_event_discard(struct ring_buffer_event *event)
event->time_delta = 1;
}
-/**
- * ring_buffer_event_discard - discard any event in the ring buffer
- * @event: the event to discard
- *
- * Sometimes a event that is in the ring buffer needs to be ignored.
- * This function lets the user discard an event in the ring buffer
- * and then that event will not be read later.
- *
- * Note, it is up to the user to be careful with this, and protect
- * against races. If the user discards an event that has been consumed
- * it is possible that it could corrupt the ring buffer.
+/*
+ * Decrement the entries to the page that an event is on.
+ * The event does not even need to exist, only the pointer
+ * to the page it is on. This may only be called before the commit
+ * takes place.
*/
-void ring_buffer_event_discard(struct ring_buffer_event *event)
+static inline void
+rb_decrement_entry(struct ring_buffer_per_cpu *cpu_buffer,
+ struct ring_buffer_event *event)
{
- rb_event_discard(event);
+ unsigned long addr = (unsigned long)event;
+ struct buffer_page *bpage = cpu_buffer->commit_page;
+ struct buffer_page *start;
+
+ addr &= PAGE_MASK;
+
+ /* Do the likely case first */
+ if (likely(bpage->page == (void *)addr)) {
+ local_dec(&bpage->entries);
+ return;
+ }
+
+ /*
+ * Because the commit page may be on the reader page we
+ * start with the next page and check the end loop there.
+ */
+ rb_inc_page(cpu_buffer, &bpage);
+ start = bpage;
+ do {
+ if (bpage->page == (void *)addr) {
+ local_dec(&bpage->entries);
+ return;
+ }
+ rb_inc_page(cpu_buffer, &bpage);
+ } while (bpage != start);
+
+ /* commit not part of this buffer?? */
+ RB_WARN_ON(cpu_buffer, 1);
}
-EXPORT_SYMBOL_GPL(ring_buffer_event_discard);
/**
* ring_buffer_commit_discard - discard an event that has not been committed
* @buffer: the ring buffer
* @event: non committed event to discard
*
- * This is similar to ring_buffer_event_discard but must only be
- * performed on an event that has not been committed yet. The difference
- * is that this will also try to free the event from the ring buffer
+ * Sometimes an event that is in the ring buffer needs to be ignored.
+ * This function lets the user discard an event in the ring buffer
+ * and then that event will not be read later.
+ *
+ * This function only works if it is called before the the item has been
+ * committed. It will try to free the event from the ring buffer
* if another event has not been added behind it.
*
* If another event has been added behind it, it will set the event
@@ -1786,14 +2423,15 @@ void ring_buffer_discard_commit(struct ring_buffer *buffer,
*/
RB_WARN_ON(buffer, !local_read(&cpu_buffer->committing));
+ rb_decrement_entry(cpu_buffer, event);
if (rb_try_to_discard(cpu_buffer, event))
goto out;
/*
* The commit is still visible by the reader, so we
- * must increment entries.
+ * must still update the timestamp.
*/
- local_inc(&cpu_buffer->entries);
+ rb_update_write_stamp(cpu_buffer, event);
out:
rb_end_commit(cpu_buffer);
@@ -1854,7 +2492,7 @@ int ring_buffer_write(struct ring_buffer *buffer,
if (length > BUF_MAX_DATA_SIZE)
goto out;
- event = rb_reserve_next_event(cpu_buffer, length);
+ event = rb_reserve_next_event(buffer, cpu_buffer, length);
if (!event)
goto out;
@@ -1875,9 +2513,13 @@ EXPORT_SYMBOL_GPL(ring_buffer_write);
static int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
{
struct buffer_page *reader = cpu_buffer->reader_page;
- struct buffer_page *head = cpu_buffer->head_page;
+ struct buffer_page *head = rb_set_head_page(cpu_buffer);
struct buffer_page *commit = cpu_buffer->commit_page;
+ /* In case of error, head will be NULL */
+ if (unlikely(!head))
+ return 1;
+
return reader->read == rb_page_commit(reader) &&
(commit == reader ||
(commit == head &&
@@ -1968,7 +2610,7 @@ unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu)
return 0;
cpu_buffer = buffer->buffers[cpu];
- ret = (local_read(&cpu_buffer->entries) - cpu_buffer->overrun)
+ ret = (local_read(&cpu_buffer->entries) - local_read(&cpu_buffer->overrun))
- cpu_buffer->read;
return ret;
@@ -1989,33 +2631,13 @@ unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu)
return 0;
cpu_buffer = buffer->buffers[cpu];
- ret = cpu_buffer->overrun;
+ ret = local_read(&cpu_buffer->overrun);
return ret;
}
EXPORT_SYMBOL_GPL(ring_buffer_overrun_cpu);
/**
- * ring_buffer_nmi_dropped_cpu - get the number of nmis that were dropped
- * @buffer: The ring buffer
- * @cpu: The per CPU buffer to get the number of overruns from
- */
-unsigned long ring_buffer_nmi_dropped_cpu(struct ring_buffer *buffer, int cpu)
-{
- struct ring_buffer_per_cpu *cpu_buffer;
- unsigned long ret;
-
- if (!cpumask_test_cpu(cpu, buffer->cpumask))
- return 0;
-
- cpu_buffer = buffer->buffers[cpu];
- ret = cpu_buffer->nmi_dropped;
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(ring_buffer_nmi_dropped_cpu);
-
-/**
* ring_buffer_commit_overrun_cpu - get the number of overruns caused by commits
* @buffer: The ring buffer
* @cpu: The per CPU buffer to get the number of overruns from
@@ -2030,7 +2652,7 @@ ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu)
return 0;
cpu_buffer = buffer->buffers[cpu];
- ret = cpu_buffer->commit_overrun;
+ ret = local_read(&cpu_buffer->commit_overrun);
return ret;
}
@@ -2053,7 +2675,7 @@ unsigned long ring_buffer_entries(struct ring_buffer *buffer)
for_each_buffer_cpu(buffer, cpu) {
cpu_buffer = buffer->buffers[cpu];
entries += (local_read(&cpu_buffer->entries) -
- cpu_buffer->overrun) - cpu_buffer->read;
+ local_read(&cpu_buffer->overrun)) - cpu_buffer->read;
}
return entries;
@@ -2076,7 +2698,7 @@ unsigned long ring_buffer_overruns(struct ring_buffer *buffer)
/* if you care about this being correct, lock the buffer */
for_each_buffer_cpu(buffer, cpu) {
cpu_buffer = buffer->buffers[cpu];
- overruns += cpu_buffer->overrun;
+ overruns += local_read(&cpu_buffer->overrun);
}
return overruns;
@@ -2089,8 +2711,10 @@ static void rb_iter_reset(struct ring_buffer_iter *iter)
/* Iterator usage is expected to have record disabled */
if (list_empty(&cpu_buffer->reader_page->list)) {
- iter->head_page = cpu_buffer->head_page;
- iter->head = cpu_buffer->head_page->read;
+ iter->head_page = rb_set_head_page(cpu_buffer);
+ if (unlikely(!iter->head_page))
+ return;
+ iter->head = iter->head_page->read;
} else {
iter->head_page = cpu_buffer->reader_page;
iter->head = cpu_buffer->reader_page->read;
@@ -2207,6 +2831,7 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
struct buffer_page *reader = NULL;
unsigned long flags;
int nr_loops = 0;
+ int ret;
local_irq_save(flags);
__raw_spin_lock(&cpu_buffer->lock);
@@ -2240,30 +2865,56 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
goto out;
/*
- * Splice the empty reader page into the list around the head.
* Reset the reader page to size zero.
*/
+ local_set(&cpu_buffer->reader_page->write, 0);
+ local_set(&cpu_buffer->reader_page->entries, 0);
+ local_set(&cpu_buffer->reader_page->page->commit, 0);
- reader = cpu_buffer->head_page;
+ spin:
+ /*
+ * Splice the empty reader page into the list around the head.
+ */
+ reader = rb_set_head_page(cpu_buffer);
cpu_buffer->reader_page->list.next = reader->list.next;
cpu_buffer->reader_page->list.prev = reader->list.prev;
- local_set(&cpu_buffer->reader_page->write, 0);
- local_set(&cpu_buffer->reader_page->entries, 0);
- local_set(&cpu_buffer->reader_page->page->commit, 0);
+ /*
+ * cpu_buffer->pages just needs to point to the buffer, it
+ * has no specific buffer page to point to. Lets move it out
+ * of our way so we don't accidently swap it.
+ */
+ cpu_buffer->pages = reader->list.prev;
- /* Make the reader page now replace the head */
- reader->list.prev->next = &cpu_buffer->reader_page->list;
- reader->list.next->prev = &cpu_buffer->reader_page->list;
+ /* The reader page will be pointing to the new head */
+ rb_set_list_to_head(cpu_buffer, &cpu_buffer->reader_page->list);
/*
- * If the tail is on the reader, then we must set the head
- * to the inserted page, otherwise we set it one before.
+ * Here's the tricky part.
+ *
+ * We need to move the pointer past the header page.
+ * But we can only do that if a writer is not currently
+ * moving it. The page before the header page has the
+ * flag bit '1' set if it is pointing to the page we want.
+ * but if the writer is in the process of moving it
+ * than it will be '2' or already moved '0'.
*/
- cpu_buffer->head_page = cpu_buffer->reader_page;
- if (cpu_buffer->commit_page != reader)
- rb_inc_page(cpu_buffer, &cpu_buffer->head_page);
+ ret = rb_head_page_replace(reader, cpu_buffer->reader_page);
+
+ /*
+ * If we did not convert it, then we must try again.
+ */
+ if (!ret)
+ goto spin;
+
+ /*
+ * Yeah! We succeeded in replacing the page.
+ *
+ * Now make the new head point back to the reader page.
+ */
+ reader->list.next->prev = &cpu_buffer->reader_page->list;
+ rb_inc_page(cpu_buffer, &cpu_buffer->head_page);
/* Finally update the reader page to the new head */
cpu_buffer->reader_page = reader;
@@ -2292,8 +2943,7 @@ static void rb_advance_reader(struct ring_buffer_per_cpu *cpu_buffer)
event = rb_reader_event(cpu_buffer);
- if (event->type_len <= RINGBUF_TYPE_DATA_TYPE_LEN_MAX
- || rb_discarded_event(event))
+ if (event->type_len <= RINGBUF_TYPE_DATA_TYPE_LEN_MAX)
cpu_buffer->read++;
rb_update_read_stamp(cpu_buffer, event);
@@ -2525,10 +3175,8 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts)
spin_unlock(&cpu_buffer->reader_lock);
local_irq_restore(flags);
- if (event && event->type_len == RINGBUF_TYPE_PADDING) {
- cpu_relax();
+ if (event && event->type_len == RINGBUF_TYPE_PADDING)
goto again;
- }
return event;
}
@@ -2553,10 +3201,8 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
event = rb_iter_peek(iter, ts);
spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
- if (event && event->type_len == RINGBUF_TYPE_PADDING) {
- cpu_relax();
+ if (event && event->type_len == RINGBUF_TYPE_PADDING)
goto again;
- }
return event;
}
@@ -2602,10 +3248,8 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts)
out:
preempt_enable();
- if (event && event->type_len == RINGBUF_TYPE_PADDING) {
- cpu_relax();
+ if (event && event->type_len == RINGBUF_TYPE_PADDING)
goto again;
- }
return event;
}
@@ -2685,21 +3329,19 @@ ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts)
struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
unsigned long flags;
- again:
spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+ again:
event = rb_iter_peek(iter, ts);
if (!event)
goto out;
+ if (event->type_len == RINGBUF_TYPE_PADDING)
+ goto again;
+
rb_advance_iter(iter);
out:
spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
- if (event && event->type_len == RINGBUF_TYPE_PADDING) {
- cpu_relax();
- goto again;
- }
-
return event;
}
EXPORT_SYMBOL_GPL(ring_buffer_read);
@@ -2717,8 +3359,10 @@ EXPORT_SYMBOL_GPL(ring_buffer_size);
static void
rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
{
+ rb_head_page_deactivate(cpu_buffer);
+
cpu_buffer->head_page
- = list_entry(cpu_buffer->pages.next, struct buffer_page, list);
+ = list_entry(cpu_buffer->pages, struct buffer_page, list);
local_set(&cpu_buffer->head_page->write, 0);
local_set(&cpu_buffer->head_page->entries, 0);
local_set(&cpu_buffer->head_page->page->commit, 0);
@@ -2734,16 +3378,17 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
local_set(&cpu_buffer->reader_page->page->commit, 0);
cpu_buffer->reader_page->read = 0;
- cpu_buffer->nmi_dropped = 0;
- cpu_buffer->commit_overrun = 0;
- cpu_buffer->overrun = 0;
- cpu_buffer->read = 0;
+ local_set(&cpu_buffer->commit_overrun, 0);
+ local_set(&cpu_buffer->overrun, 0);
local_set(&cpu_buffer->entries, 0);
local_set(&cpu_buffer->committing, 0);
local_set(&cpu_buffer->commits, 0);
+ cpu_buffer->read = 0;
cpu_buffer->write_stamp = 0;
cpu_buffer->read_stamp = 0;
+
+ rb_head_page_activate(cpu_buffer);
}
/**
@@ -2763,12 +3408,16 @@ void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu)
spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+ if (RB_WARN_ON(cpu_buffer, local_read(&cpu_buffer->committing)))
+ goto out;
+
__raw_spin_lock(&cpu_buffer->lock);
rb_reset_cpu(cpu_buffer);
__raw_spin_unlock(&cpu_buffer->lock);
+ out:
spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
atomic_dec(&cpu_buffer->record_disabled);
@@ -2851,6 +3500,7 @@ int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu)
}
EXPORT_SYMBOL_GPL(ring_buffer_empty_cpu);
+#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP
/**
* ring_buffer_swap_cpu - swap a CPU buffer between two ring buffers
* @buffer_a: One buffer to swap with
@@ -2905,20 +3555,28 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
atomic_inc(&cpu_buffer_a->record_disabled);
atomic_inc(&cpu_buffer_b->record_disabled);
+ ret = -EBUSY;
+ if (local_read(&cpu_buffer_a->committing))
+ goto out_dec;
+ if (local_read(&cpu_buffer_b->committing))
+ goto out_dec;
+
buffer_a->buffers[cpu] = cpu_buffer_b;
buffer_b->buffers[cpu] = cpu_buffer_a;
cpu_buffer_b->buffer = buffer_a;
cpu_buffer_a->buffer = buffer_b;
+ ret = 0;
+
+out_dec:
atomic_dec(&cpu_buffer_a->record_disabled);
atomic_dec(&cpu_buffer_b->record_disabled);
-
- ret = 0;
out:
return ret;
}
EXPORT_SYMBOL_GPL(ring_buffer_swap_cpu);
+#endif /* CONFIG_RING_BUFFER_ALLOW_SWAP */
/**
* ring_buffer_alloc_read_page - allocate a page to read from buffer
@@ -3091,7 +3749,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
read = 0;
} else {
/* update the entry counter */
- cpu_buffer->read += local_read(&reader->entries);
+ cpu_buffer->read += rb_page_entries(reader);
/* swap the pages */
rb_init_page(bpage);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8c358395d338..5c75deeefe30 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -43,14 +43,11 @@
#define TRACE_BUFFER_FLAGS (RB_FL_OVERWRITE)
-unsigned long __read_mostly tracing_max_latency;
-unsigned long __read_mostly tracing_thresh;
-
/*
* On boot up, the ring buffer is set to the minimum size, so that
* we do not waste memory on systems that are not using tracing.
*/
-static int ring_buffer_expanded;
+int ring_buffer_expanded;
/*
* We need to change this state when a selftest is running.
@@ -64,7 +61,7 @@ static bool __read_mostly tracing_selftest_running;
/*
* If a tracer is running, we do not want to run SELFTEST.
*/
-static bool __read_mostly tracing_selftest_disabled;
+bool __read_mostly tracing_selftest_disabled;
/* For tracers that don't implement custom flags */
static struct tracer_opt dummy_tracer_opt[] = {
@@ -89,7 +86,7 @@ static int dummy_set_flag(u32 old_flags, u32 bit, int set)
*/
static int tracing_disabled = 1;
-static DEFINE_PER_CPU(local_t, ftrace_cpu_disabled);
+DEFINE_PER_CPU(local_t, ftrace_cpu_disabled);
static inline void ftrace_disable_cpu(void)
{
@@ -172,10 +169,11 @@ static struct trace_array global_trace;
static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu);
-int filter_current_check_discard(struct ftrace_event_call *call, void *rec,
+int filter_current_check_discard(struct ring_buffer *buffer,
+ struct ftrace_event_call *call, void *rec,
struct ring_buffer_event *event)
{
- return filter_check_discard(call, rec, global_trace.buffer, event);
+ return filter_check_discard(call, rec, buffer, event);
}
EXPORT_SYMBOL_GPL(filter_current_check_discard);
@@ -266,6 +264,9 @@ unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME |
TRACE_ITER_GRAPH_TIME;
+static int trace_stop_count;
+static DEFINE_SPINLOCK(tracing_start_lock);
+
/**
* trace_wake_up - wake up tasks waiting for trace input
*
@@ -323,50 +324,20 @@ static const char *trace_options[] = {
"printk-msg-only",
"context-info",
"latency-format",
- "global-clock",
"sleep-time",
"graph-time",
NULL
};
-/*
- * ftrace_max_lock is used to protect the swapping of buffers
- * when taking a max snapshot. The buffers themselves are
- * protected by per_cpu spinlocks. But the action of the swap
- * needs its own lock.
- *
- * This is defined as a raw_spinlock_t in order to help
- * with performance when lockdep debugging is enabled.
- */
-static raw_spinlock_t ftrace_max_lock =
- (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
-
-/*
- * Copy the new maximum trace into the separate maximum-trace
- * structure. (this way the maximum trace is permanently saved,
- * for later retrieval via /sys/kernel/debug/tracing/latency_trace)
- */
-static void
-__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
-{
- struct trace_array_cpu *data = tr->data[cpu];
-
- max_tr.cpu = cpu;
- max_tr.time_start = data->preempt_timestamp;
+static struct {
+ u64 (*func)(void);
+ const char *name;
+} trace_clocks[] = {
+ { trace_clock_local, "local" },
+ { trace_clock_global, "global" },
+};
- data = max_tr.data[cpu];
- data->saved_latency = tracing_max_latency;
-
- memcpy(data->comm, tsk->comm, TASK_COMM_LEN);
- data->pid = tsk->pid;
- data->uid = task_uid(tsk);
- data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
- data->policy = tsk->policy;
- data->rt_priority = tsk->rt_priority;
-
- /* record this tasks comm */
- tracing_record_cmdline(tsk);
-}
+int trace_clock_id;
ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
{
@@ -411,6 +382,56 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
return cnt;
}
+/*
+ * ftrace_max_lock is used to protect the swapping of buffers
+ * when taking a max snapshot. The buffers themselves are
+ * protected by per_cpu spinlocks. But the action of the swap
+ * needs its own lock.
+ *
+ * This is defined as a raw_spinlock_t in order to help
+ * with performance when lockdep debugging is enabled.
+ *
+ * It is also used in other places outside the update_max_tr
+ * so it needs to be defined outside of the
+ * CONFIG_TRACER_MAX_TRACE.
+ */
+static raw_spinlock_t ftrace_max_lock =
+ (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+unsigned long __read_mostly tracing_max_latency;
+unsigned long __read_mostly tracing_thresh;
+
+/*
+ * Copy the new maximum trace into the separate maximum-trace
+ * structure. (this way the maximum trace is permanently saved,
+ * for later retrieval via /sys/kernel/debug/tracing/latency_trace)
+ */
+static void
+__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
+{
+ struct trace_array_cpu *data = tr->data[cpu];
+ struct trace_array_cpu *max_data = tr->data[cpu];
+
+ max_tr.cpu = cpu;
+ max_tr.time_start = data->preempt_timestamp;
+
+ max_data = max_tr.data[cpu];
+ max_data->saved_latency = tracing_max_latency;
+ max_data->critical_start = data->critical_start;
+ max_data->critical_end = data->critical_end;
+
+ memcpy(data->comm, tsk->comm, TASK_COMM_LEN);
+ max_data->pid = tsk->pid;
+ max_data->uid = task_uid(tsk);
+ max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
+ max_data->policy = tsk->policy;
+ max_data->rt_priority = tsk->rt_priority;
+
+ /* record this tasks comm */
+ tracing_record_cmdline(tsk);
+}
+
/**
* update_max_tr - snapshot all trace buffers from global_trace to max_tr
* @tr: tracer
@@ -425,16 +446,15 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
struct ring_buffer *buf = tr->buffer;
+ if (trace_stop_count)
+ return;
+
WARN_ON_ONCE(!irqs_disabled());
__raw_spin_lock(&ftrace_max_lock);
tr->buffer = max_tr.buffer;
max_tr.buffer = buf;
- ftrace_disable_cpu();
- ring_buffer_reset(tr->buffer);
- ftrace_enable_cpu();
-
__update_max_tr(tr, tsk, cpu);
__raw_spin_unlock(&ftrace_max_lock);
}
@@ -452,21 +472,35 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
int ret;
+ if (trace_stop_count)
+ return;
+
WARN_ON_ONCE(!irqs_disabled());
__raw_spin_lock(&ftrace_max_lock);
ftrace_disable_cpu();
- ring_buffer_reset(max_tr.buffer);
ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu);
+ if (ret == -EBUSY) {
+ /*
+ * We failed to swap the buffer due to a commit taking
+ * place on this CPU. We fail to record, but we reset
+ * the max trace buffer (no one writes directly to it)
+ * and flag that it failed.
+ */
+ trace_array_printk(&max_tr, _THIS_IP_,
+ "Failed to swap buffers due to commit in progress\n");
+ }
+
ftrace_enable_cpu();
- WARN_ON_ONCE(ret && ret != -EAGAIN);
+ WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY);
__update_max_tr(tr, tsk, cpu);
__raw_spin_unlock(&ftrace_max_lock);
}
+#endif /* CONFIG_TRACER_MAX_TRACE */
/**
* register_tracer - register a tracer with the ftrace system.
@@ -523,7 +557,6 @@ __acquires(kernel_lock)
if (type->selftest && !tracing_selftest_disabled) {
struct tracer *saved_tracer = current_trace;
struct trace_array *tr = &global_trace;
- int i;
/*
* Run a selftest on this tracer.
@@ -532,8 +565,7 @@ __acquires(kernel_lock)
* internal tracing to verify that everything is in order.
* If we fail, we do not register this tracer.
*/
- for_each_tracing_cpu(i)
- tracing_reset(tr, i);
+ tracing_reset_online_cpus(tr);
current_trace = type;
/* the test is responsible for initializing and enabling */
@@ -546,8 +578,7 @@ __acquires(kernel_lock)
goto out;
}
/* Only reset on passing, to avoid touching corrupted buffers */
- for_each_tracing_cpu(i)
- tracing_reset(tr, i);
+ tracing_reset_online_cpus(tr);
printk(KERN_CONT "PASSED\n");
}
@@ -622,21 +653,42 @@ void unregister_tracer(struct tracer *type)
mutex_unlock(&trace_types_lock);
}
-void tracing_reset(struct trace_array *tr, int cpu)
+static void __tracing_reset(struct trace_array *tr, int cpu)
{
ftrace_disable_cpu();
ring_buffer_reset_cpu(tr->buffer, cpu);
ftrace_enable_cpu();
}
+void tracing_reset(struct trace_array *tr, int cpu)
+{
+ struct ring_buffer *buffer = tr->buffer;
+
+ ring_buffer_record_disable(buffer);
+
+ /* Make sure all commits have finished */
+ synchronize_sched();
+ __tracing_reset(tr, cpu);
+
+ ring_buffer_record_enable(buffer);
+}
+
void tracing_reset_online_cpus(struct trace_array *tr)
{
+ struct ring_buffer *buffer = tr->buffer;
int cpu;
+ ring_buffer_record_disable(buffer);
+
+ /* Make sure all commits have finished */
+ synchronize_sched();
+
tr->time_start = ftrace_now(tr->cpu);
for_each_online_cpu(cpu)
- tracing_reset(tr, cpu);
+ __tracing_reset(tr, cpu);
+
+ ring_buffer_record_enable(buffer);
}
void tracing_reset_current(int cpu)
@@ -667,9 +719,6 @@ static void trace_init_cmdlines(void)
cmdline_idx = 0;
}
-static int trace_stop_count;
-static DEFINE_SPINLOCK(tracing_start_lock);
-
/**
* ftrace_off_permanent - disable all ftrace code permanently
*
@@ -850,14 +899,15 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
}
EXPORT_SYMBOL_GPL(tracing_generic_entry_update);
-struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
- int type,
- unsigned long len,
- unsigned long flags, int pc)
+struct ring_buffer_event *
+trace_buffer_lock_reserve(struct ring_buffer *buffer,
+ int type,
+ unsigned long len,
+ unsigned long flags, int pc)
{
struct ring_buffer_event *event;
- event = ring_buffer_lock_reserve(tr->buffer, len);
+ event = ring_buffer_lock_reserve(buffer, len);
if (event != NULL) {
struct trace_entry *ent = ring_buffer_event_data(event);
@@ -867,58 +917,60 @@ struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
return event;
}
-static void ftrace_trace_stack(struct trace_array *tr,
- unsigned long flags, int skip, int pc);
-static void ftrace_trace_userstack(struct trace_array *tr,
- unsigned long flags, int pc);
-static inline void __trace_buffer_unlock_commit(struct trace_array *tr,
- struct ring_buffer_event *event,
- unsigned long flags, int pc,
- int wake)
+static inline void
+__trace_buffer_unlock_commit(struct ring_buffer *buffer,
+ struct ring_buffer_event *event,
+ unsigned long flags, int pc,
+ int wake)
{
- ring_buffer_unlock_commit(tr->buffer, event);
+ ring_buffer_unlock_commit(buffer, event);
- ftrace_trace_stack(tr, flags, 6, pc);
- ftrace_trace_userstack(tr, flags, pc);
+ ftrace_trace_stack(buffer, flags, 6, pc);
+ ftrace_trace_userstack(buffer, flags, pc);
if (wake)
trace_wake_up();
}
-void trace_buffer_unlock_commit(struct trace_array *tr,
- struct ring_buffer_event *event,
- unsigned long flags, int pc)
+void trace_buffer_unlock_commit(struct ring_buffer *buffer,
+ struct ring_buffer_event *event,
+ unsigned long flags, int pc)
{
- __trace_buffer_unlock_commit(tr, event, flags, pc, 1);
+ __trace_buffer_unlock_commit(buffer, event, flags, pc, 1);
}
struct ring_buffer_event *
-trace_current_buffer_lock_reserve(int type, unsigned long len,
+trace_current_buffer_lock_reserve(struct ring_buffer **current_rb,
+ int type, unsigned long len,
unsigned long flags, int pc)
{
- return trace_buffer_lock_reserve(&global_trace,
+ *current_rb = global_trace.buffer;
+ return trace_buffer_lock_reserve(*current_rb,
type, len, flags, pc);
}
EXPORT_SYMBOL_GPL(trace_current_buffer_lock_reserve);
-void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
+void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
+ struct ring_buffer_event *event,
unsigned long flags, int pc)
{
- __trace_buffer_unlock_commit(&global_trace, event, flags, pc, 1);
+ __trace_buffer_unlock_commit(buffer, event, flags, pc, 1);
}
EXPORT_SYMBOL_GPL(trace_current_buffer_unlock_commit);
-void trace_nowake_buffer_unlock_commit(struct ring_buffer_event *event,
- unsigned long flags, int pc)
+void trace_nowake_buffer_unlock_commit(struct ring_buffer *buffer,
+ struct ring_buffer_event *event,
+ unsigned long flags, int pc)
{
- __trace_buffer_unlock_commit(&global_trace, event, flags, pc, 0);
+ __trace_buffer_unlock_commit(buffer, event, flags, pc, 0);
}
EXPORT_SYMBOL_GPL(trace_nowake_buffer_unlock_commit);
-void trace_current_buffer_discard_commit(struct ring_buffer_event *event)
+void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
+ struct ring_buffer_event *event)
{
- ring_buffer_discard_commit(global_trace.buffer, event);
+ ring_buffer_discard_commit(buffer, event);
}
EXPORT_SYMBOL_GPL(trace_current_buffer_discard_commit);
@@ -928,6 +980,7 @@ trace_function(struct trace_array *tr,
int pc)
{
struct ftrace_event_call *call = &event_function;
+ struct ring_buffer *buffer = tr->buffer;
struct ring_buffer_event *event;
struct ftrace_entry *entry;
@@ -935,7 +988,7 @@ trace_function(struct trace_array *tr,
if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
return;
- event = trace_buffer_lock_reserve(tr, TRACE_FN, sizeof(*entry),
+ event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry),
flags, pc);
if (!event)
return;
@@ -943,58 +996,10 @@ trace_function(struct trace_array *tr,
entry->ip = ip;
entry->parent_ip = parent_ip;
- if (!filter_check_discard(call, entry, tr->buffer, event))
- ring_buffer_unlock_commit(tr->buffer, event);
-}
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-static int __trace_graph_entry(struct trace_array *tr,
- struct ftrace_graph_ent *trace,
- unsigned long flags,
- int pc)
-{
- struct ftrace_event_call *call = &event_funcgraph_entry;
- struct ring_buffer_event *event;
- struct ftrace_graph_ent_entry *entry;
-
- if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
- return 0;
-
- event = trace_buffer_lock_reserve(&global_trace, TRACE_GRAPH_ENT,
- sizeof(*entry), flags, pc);
- if (!event)
- return 0;
- entry = ring_buffer_event_data(event);
- entry->graph_ent = *trace;
- if (!filter_current_check_discard(call, entry, event))
- ring_buffer_unlock_commit(global_trace.buffer, event);
-
- return 1;
+ if (!filter_check_discard(call, entry, buffer, event))
+ ring_buffer_unlock_commit(buffer, event);
}
-static void __trace_graph_return(struct trace_array *tr,
- struct ftrace_graph_ret *trace,
- unsigned long flags,
- int pc)
-{
- struct ftrace_event_call *call = &event_funcgraph_exit;
- struct ring_buffer_event *event;
- struct ftrace_graph_ret_entry *entry;
-
- if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
- return;
-
- event = trace_buffer_lock_reserve(&global_trace, TRACE_GRAPH_RET,
- sizeof(*entry), flags, pc);
- if (!event)
- return;
- entry = ring_buffer_event_data(event);
- entry->ret = *trace;
- if (!filter_current_check_discard(call, entry, event))
- ring_buffer_unlock_commit(global_trace.buffer, event);
-}
-#endif
-
void
ftrace(struct trace_array *tr, struct trace_array_cpu *data,
unsigned long ip, unsigned long parent_ip, unsigned long flags,
@@ -1004,17 +1009,17 @@ ftrace(struct trace_array *tr, struct trace_array_cpu *data,
trace_function(tr, ip, parent_ip, flags, pc);
}
-static void __ftrace_trace_stack(struct trace_array *tr,
+#ifdef CONFIG_STACKTRACE
+static void __ftrace_trace_stack(struct ring_buffer *buffer,
unsigned long flags,
int skip, int pc)
{
-#ifdef CONFIG_STACKTRACE
struct ftrace_event_call *call = &event_kernel_stack;
struct ring_buffer_event *event;
struct stack_entry *entry;
struct stack_trace trace;
- event = trace_buffer_lock_reserve(tr, TRACE_STACK,
+ event = trace_buffer_lock_reserve(buffer, TRACE_STACK,
sizeof(*entry), flags, pc);
if (!event)
return;
@@ -1027,32 +1032,28 @@ static void __ftrace_trace_stack(struct trace_array *tr,
trace.entries = entry->caller;
save_stack_trace(&trace);
- if (!filter_check_discard(call, entry, tr->buffer, event))
- ring_buffer_unlock_commit(tr->buffer, event);
-#endif
+ if (!filter_check_discard(call, entry, buffer, event))
+ ring_buffer_unlock_commit(buffer, event);
}
-static void ftrace_trace_stack(struct trace_array *tr,
- unsigned long flags,
- int skip, int pc)
+void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
+ int skip, int pc)
{
if (!(trace_flags & TRACE_ITER_STACKTRACE))
return;
- __ftrace_trace_stack(tr, flags, skip, pc);
+ __ftrace_trace_stack(buffer, flags, skip, pc);
}
-void __trace_stack(struct trace_array *tr,
- unsigned long flags,
- int skip, int pc)
+void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
+ int pc)
{
- __ftrace_trace_stack(tr, flags, skip, pc);
+ __ftrace_trace_stack(tr->buffer, flags, skip, pc);
}
-static void ftrace_trace_userstack(struct trace_array *tr,
- unsigned long flags, int pc)
+void
+ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
{
-#ifdef CONFIG_STACKTRACE
struct ftrace_event_call *call = &event_user_stack;
struct ring_buffer_event *event;
struct userstack_entry *entry;
@@ -1061,7 +1062,7 @@ static void ftrace_trace_userstack(struct trace_array *tr,
if (!(trace_flags & TRACE_ITER_USERSTACKTRACE))
return;
- event = trace_buffer_lock_reserve(tr, TRACE_USER_STACK,
+ event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK,
sizeof(*entry), flags, pc);
if (!event)
return;
@@ -1075,9 +1076,8 @@ static void ftrace_trace_userstack(struct trace_array *tr,
trace.entries = entry->caller;
save_stack_trace_user(&trace);
- if (!filter_check_discard(call, entry, tr->buffer, event))
- ring_buffer_unlock_commit(tr->buffer, event);
-#endif
+ if (!filter_check_discard(call, entry, buffer, event))
+ ring_buffer_unlock_commit(buffer, event);
}
#ifdef UNUSED
@@ -1087,6 +1087,8 @@ static void __trace_userstack(struct trace_array *tr, unsigned long flags)
}
#endif /* UNUSED */
+#endif /* CONFIG_STACKTRACE */
+
static void
ftrace_trace_special(void *__tr,
unsigned long arg1, unsigned long arg2, unsigned long arg3,
@@ -1094,9 +1096,10 @@ ftrace_trace_special(void *__tr,
{
struct ring_buffer_event *event;
struct trace_array *tr = __tr;
+ struct ring_buffer *buffer = tr->buffer;
struct special_entry *entry;
- event = trace_buffer_lock_reserve(tr, TRACE_SPECIAL,
+ event = trace_buffer_lock_reserve(buffer, TRACE_SPECIAL,
sizeof(*entry), 0, pc);
if (!event)
return;
@@ -1104,7 +1107,7 @@ ftrace_trace_special(void *__tr,
entry->arg1 = arg1;
entry->arg2 = arg2;
entry->arg3 = arg3;
- trace_buffer_unlock_commit(tr, event, 0, pc);
+ trace_buffer_unlock_commit(buffer, event, 0, pc);
}
void
@@ -1115,62 +1118,6 @@ __trace_special(void *__tr, void *__data,
}
void
-tracing_sched_switch_trace(struct trace_array *tr,
- struct task_struct *prev,
- struct task_struct *next,
- unsigned long flags, int pc)
-{
- struct ftrace_event_call *call = &event_context_switch;
- struct ring_buffer_event *event;
- struct ctx_switch_entry *entry;
-
- event = trace_buffer_lock_reserve(tr, TRACE_CTX,
- sizeof(*entry), flags, pc);
- if (!event)
- return;
- entry = ring_buffer_event_data(event);
- entry->prev_pid = prev->pid;
- entry->prev_prio = prev->prio;
- entry->prev_state = prev->state;
- entry->next_pid = next->pid;
- entry->next_prio = next->prio;
- entry->next_state = next->state;
- entry->next_cpu = task_cpu(next);
-
- if (!filter_check_discard(call, entry, tr->buffer, event))
- trace_buffer_unlock_commit(tr, event, flags, pc);
-}
-
-void
-tracing_sched_wakeup_trace(struct trace_array *tr,
- struct task_struct *wakee,
- struct task_struct *curr,
- unsigned long flags, int pc)
-{
- struct ftrace_event_call *call = &event_wakeup;
- struct ring_buffer_event *event;
- struct ctx_switch_entry *entry;
-
- event = trace_buffer_lock_reserve(tr, TRACE_WAKE,
- sizeof(*entry), flags, pc);
- if (!event)
- return;
- entry = ring_buffer_event_data(event);
- entry->prev_pid = curr->pid;
- entry->prev_prio = curr->prio;
- entry->prev_state = curr->state;
- entry->next_pid = wakee->pid;
- entry->next_prio = wakee->prio;
- entry->next_state = wakee->state;
- entry->next_cpu = task_cpu(wakee);
-
- if (!filter_check_discard(call, entry, tr->buffer, event))
- ring_buffer_unlock_commit(tr->buffer, event);
- ftrace_trace_stack(tr, flags, 6, pc);
- ftrace_trace_userstack(tr, flags, pc);
-}
-
-void
ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
{
struct trace_array *tr = &global_trace;
@@ -1194,68 +1141,6 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
local_irq_restore(flags);
}
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-int trace_graph_entry(struct ftrace_graph_ent *trace)
-{
- struct trace_array *tr = &global_trace;
- struct trace_array_cpu *data;
- unsigned long flags;
- long disabled;
- int ret;
- int cpu;
- int pc;
-
- if (!ftrace_trace_task(current))
- return 0;
-
- if (!ftrace_graph_addr(trace->func))
- return 0;
-
- local_irq_save(flags);
- cpu = raw_smp_processor_id();
- data = tr->data[cpu];
- disabled = atomic_inc_return(&data->disabled);
- if (likely(disabled == 1)) {
- pc = preempt_count();
- ret = __trace_graph_entry(tr, trace, flags, pc);
- } else {
- ret = 0;
- }
- /* Only do the atomic if it is not already set */
- if (!test_tsk_trace_graph(current))
- set_tsk_trace_graph(current);
-
- atomic_dec(&data->disabled);
- local_irq_restore(flags);
-
- return ret;
-}
-
-void trace_graph_return(struct ftrace_graph_ret *trace)
-{
- struct trace_array *tr = &global_trace;
- struct trace_array_cpu *data;
- unsigned long flags;
- long disabled;
- int cpu;
- int pc;
-
- local_irq_save(flags);
- cpu = raw_smp_processor_id();
- data = tr->data[cpu];
- disabled = atomic_inc_return(&data->disabled);
- if (likely(disabled == 1)) {
- pc = preempt_count();
- __trace_graph_return(tr, trace, flags, pc);
- }
- if (!trace->depth)
- clear_tsk_trace_graph(current);
- atomic_dec(&data->disabled);
- local_irq_restore(flags);
-}
-#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
-
-
/**
* trace_vbprintk - write binary msg to tracing buffer
*
@@ -1268,6 +1153,7 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
struct ftrace_event_call *call = &event_bprint;
struct ring_buffer_event *event;
+ struct ring_buffer *buffer;
struct trace_array *tr = &global_trace;
struct trace_array_cpu *data;
struct bprint_entry *entry;
@@ -1300,7 +1186,9 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
goto out_unlock;
size = sizeof(*entry) + sizeof(u32) * len;
- event = trace_buffer_lock_reserve(tr, TRACE_BPRINT, size, flags, pc);
+ buffer = tr->buffer;
+ event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size,
+ flags, pc);
if (!event)
goto out_unlock;
entry = ring_buffer_event_data(event);
@@ -1308,8 +1196,8 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
entry->fmt = fmt;
memcpy(entry->buf, trace_buf, sizeof(u32) * len);
- if (!filter_check_discard(call, entry, tr->buffer, event))
- ring_buffer_unlock_commit(tr->buffer, event);
+ if (!filter_check_discard(call, entry, buffer, event))
+ ring_buffer_unlock_commit(buffer, event);
out_unlock:
__raw_spin_unlock(&trace_buf_lock);
@@ -1324,14 +1212,30 @@ out:
}
EXPORT_SYMBOL_GPL(trace_vbprintk);
-int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
+int trace_array_printk(struct trace_array *tr,
+ unsigned long ip, const char *fmt, ...)
+{
+ int ret;
+ va_list ap;
+
+ if (!(trace_flags & TRACE_ITER_PRINTK))
+ return 0;
+
+ va_start(ap, fmt);
+ ret = trace_array_vprintk(tr, ip, fmt, ap);
+ va_end(ap);
+ return ret;
+}
+
+int trace_array_vprintk(struct trace_array *tr,
+ unsigned long ip, const char *fmt, va_list args)
{
static raw_spinlock_t trace_buf_lock = __RAW_SPIN_LOCK_UNLOCKED;
static char trace_buf[TRACE_BUF_SIZE];
struct ftrace_event_call *call = &event_print;
struct ring_buffer_event *event;
- struct trace_array *tr = &global_trace;
+ struct ring_buffer *buffer;
struct trace_array_cpu *data;
int cpu, len = 0, size, pc;
struct print_entry *entry;
@@ -1359,7 +1263,9 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
trace_buf[len] = 0;
size = sizeof(*entry) + len + 1;
- event = trace_buffer_lock_reserve(tr, TRACE_PRINT, size, irq_flags, pc);
+ buffer = tr->buffer;
+ event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
+ irq_flags, pc);
if (!event)
goto out_unlock;
entry = ring_buffer_event_data(event);
@@ -1367,8 +1273,8 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
memcpy(&entry->buf, trace_buf, len);
entry->buf[len] = 0;
- if (!filter_check_discard(call, entry, tr->buffer, event))
- ring_buffer_unlock_commit(tr->buffer, event);
+ if (!filter_check_discard(call, entry, buffer, event))
+ ring_buffer_unlock_commit(buffer, event);
out_unlock:
__raw_spin_unlock(&trace_buf_lock);
@@ -1380,6 +1286,11 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
return len;
}
+
+int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
+{
+ return trace_array_printk(&global_trace, ip, fmt, args);
+}
EXPORT_SYMBOL_GPL(trace_vprintk);
enum trace_file_type {
@@ -1519,6 +1430,37 @@ static void *s_next(struct seq_file *m, void *v, loff_t *pos)
return ent;
}
+static void tracing_iter_reset(struct trace_iterator *iter, int cpu)
+{
+ struct trace_array *tr = iter->tr;
+ struct ring_buffer_event *event;
+ struct ring_buffer_iter *buf_iter;
+ unsigned long entries = 0;
+ u64 ts;
+
+ tr->data[cpu]->skipped_entries = 0;
+
+ if (!iter->buffer_iter[cpu])
+ return;
+
+ buf_iter = iter->buffer_iter[cpu];
+ ring_buffer_iter_reset(buf_iter);
+
+ /*
+ * We could have the case with the max latency tracers
+ * that a reset never took place on a cpu. This is evident
+ * by the timestamp being before the start of the buffer.
+ */
+ while ((event = ring_buffer_iter_peek(buf_iter, &ts))) {
+ if (ts >= iter->tr->time_start)
+ break;
+ entries++;
+ ring_buffer_read(buf_iter, NULL);
+ }
+
+ tr->data[cpu]->skipped_entries = entries;
+}
+
/*
* No necessary locking here. The worst thing which can
* happen is loosing events consumed at the same time
@@ -1557,10 +1499,9 @@ static void *s_start(struct seq_file *m, loff_t *pos)
if (cpu_file == TRACE_PIPE_ALL_CPU) {
for_each_tracing_cpu(cpu)
- ring_buffer_iter_reset(iter->buffer_iter[cpu]);
+ tracing_iter_reset(iter, cpu);
} else
- ring_buffer_iter_reset(iter->buffer_iter[cpu_file]);
-
+ tracing_iter_reset(iter, cpu_file);
ftrace_enable_cpu();
@@ -1609,16 +1550,32 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
struct trace_array *tr = iter->tr;
struct trace_array_cpu *data = tr->data[tr->cpu];
struct tracer *type = current_trace;
- unsigned long total;
- unsigned long entries;
+ unsigned long entries = 0;
+ unsigned long total = 0;
+ unsigned long count;
const char *name = "preemption";
+ int cpu;
if (type)
name = type->name;
- entries = ring_buffer_entries(iter->tr->buffer);
- total = entries +
- ring_buffer_overruns(iter->tr->buffer);
+
+ for_each_tracing_cpu(cpu) {
+ count = ring_buffer_entries_cpu(tr->buffer, cpu);
+ /*
+ * If this buffer has skipped entries, then we hold all
+ * entries for the trace and we need to ignore the
+ * ones before the time stamp.
+ */
+ if (tr->data[cpu]->skipped_entries) {
+ count -= tr->data[cpu]->skipped_entries;
+ /* total is the same as the entries */
+ total += count;
+ } else
+ total += count +
+ ring_buffer_overrun_cpu(tr->buffer, cpu);
+ entries += count;
+ }
seq_printf(m, "# %s latency trace v1.1.5 on %s\n",
name, UTS_RELEASE);
@@ -1660,7 +1617,7 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
seq_puts(m, "\n# => ended at: ");
seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags);
trace_print_seq(m, &iter->seq);
- seq_puts(m, "#\n");
+ seq_puts(m, "\n#\n");
}
seq_puts(m, "#\n");
@@ -1679,6 +1636,9 @@ static void test_cpu_buff_start(struct trace_iterator *iter)
if (cpumask_test_cpu(iter->cpu, iter->started))
return;
+ if (iter->tr->data[iter->cpu]->skipped_entries)
+ return;
+
cpumask_set_cpu(iter->cpu, iter->started);
/* Don't print started cpu buffer for the first entry of the trace */
@@ -1941,19 +1901,23 @@ __tracing_open(struct inode *inode, struct file *file)
if (ring_buffer_overruns(iter->tr->buffer))
iter->iter_flags |= TRACE_FILE_ANNOTATE;
+ /* stop the trace while dumping */
+ tracing_stop();
+
if (iter->cpu_file == TRACE_PIPE_ALL_CPU) {
for_each_tracing_cpu(cpu) {
iter->buffer_iter[cpu] =
ring_buffer_read_start(iter->tr->buffer, cpu);
+ tracing_iter_reset(iter, cpu);
}
} else {
cpu = iter->cpu_file;
iter->buffer_iter[cpu] =
ring_buffer_read_start(iter->tr->buffer, cpu);
+ tracing_iter_reset(iter, cpu);
}
- /* TODO stop tracer */
ret = seq_open(file, &tracer_seq_ops);
if (ret < 0) {
fail_ret = ERR_PTR(ret);
@@ -1963,9 +1927,6 @@ __tracing_open(struct inode *inode, struct file *file)
m = file->private_data;
m->private = iter;
- /* stop the trace while dumping */
- tracing_stop();
-
mutex_unlock(&trace_types_lock);
return iter;
@@ -1976,6 +1937,7 @@ __tracing_open(struct inode *inode, struct file *file)
ring_buffer_read_finish(iter->buffer_iter[cpu]);
}
free_cpumask_var(iter->started);
+ tracing_start();
fail:
mutex_unlock(&trace_types_lock);
kfree(iter->trace);
@@ -2257,8 +2219,8 @@ tracing_trace_options_read(struct file *filp, char __user *ubuf,
len += 3; /* "no" and newline */
}
- /* +2 for \n and \0 */
- buf = kmalloc(len + 2, GFP_KERNEL);
+ /* +1 for \0 */
+ buf = kmalloc(len + 1, GFP_KERNEL);
if (!buf) {
mutex_unlock(&trace_types_lock);
return -ENOMEM;
@@ -2281,7 +2243,7 @@ tracing_trace_options_read(struct file *filp, char __user *ubuf,
}
mutex_unlock(&trace_types_lock);
- WARN_ON(r >= len + 2);
+ WARN_ON(r >= len + 1);
r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
@@ -2292,23 +2254,23 @@ tracing_trace_options_read(struct file *filp, char __user *ubuf,
/* Try to assign a tracer specific option */
static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
{
- struct tracer_flags *trace_flags = trace->flags;
+ struct tracer_flags *tracer_flags = trace->flags;
struct tracer_opt *opts = NULL;
int ret = 0, i = 0;
int len;
- for (i = 0; trace_flags->opts[i].name; i++) {
- opts = &trace_flags->opts[i];
+ for (i = 0; tracer_flags->opts[i].name; i++) {
+ opts = &tracer_flags->opts[i];
len = strlen(opts->name);
if (strncmp(cmp, opts->name, len) == 0) {
- ret = trace->set_flag(trace_flags->val,
+ ret = trace->set_flag(tracer_flags->val,
opts->bit, !neg);
break;
}
}
/* Not found */
- if (!trace_flags->opts[i].name)
+ if (!tracer_flags->opts[i].name)
return -EINVAL;
/* Refused to handle */
@@ -2316,9 +2278,9 @@ static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
return ret;
if (neg)
- trace_flags->val &= ~opts->bit;
+ tracer_flags->val &= ~opts->bit;
else
- trace_flags->val |= opts->bit;
+ tracer_flags->val |= opts->bit;
return 0;
}
@@ -2333,22 +2295,6 @@ static void set_tracer_flags(unsigned int mask, int enabled)
trace_flags |= mask;
else
trace_flags &= ~mask;
-
- if (mask == TRACE_ITER_GLOBAL_CLK) {
- u64 (*func)(void);
-
- if (enabled)
- func = trace_clock_global;
- else
- func = trace_clock_local;
-
- mutex_lock(&trace_types_lock);
- ring_buffer_set_clock(global_trace.buffer, func);
-
- if (max_tr.buffer)
- ring_buffer_set_clock(max_tr.buffer, func);
- mutex_unlock(&trace_types_lock);
- }
}
static ssize_t
@@ -3316,6 +3262,62 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
return cnt;
}
+static ssize_t tracing_clock_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ int bufiter = 0;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(trace_clocks); i++)
+ bufiter += snprintf(buf + bufiter, sizeof(buf) - bufiter,
+ "%s%s%s%s", i ? " " : "",
+ i == trace_clock_id ? "[" : "", trace_clocks[i].name,
+ i == trace_clock_id ? "]" : "");
+ bufiter += snprintf(buf + bufiter, sizeof(buf) - bufiter, "\n");
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, bufiter);
+}
+
+static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *fpos)
+{
+ char buf[64];
+ const char *clockstr;
+ int i;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ clockstr = strstrip(buf);
+
+ for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) {
+ if (strcmp(trace_clocks[i].name, clockstr) == 0)
+ break;
+ }
+ if (i == ARRAY_SIZE(trace_clocks))
+ return -EINVAL;
+
+ trace_clock_id = i;
+
+ mutex_lock(&trace_types_lock);
+
+ ring_buffer_set_clock(global_trace.buffer, trace_clocks[i].func);
+ if (max_tr.buffer)
+ ring_buffer_set_clock(max_tr.buffer, trace_clocks[i].func);
+
+ mutex_unlock(&trace_types_lock);
+
+ *fpos += cnt;
+
+ return cnt;
+}
+
static const struct file_operations tracing_max_lat_fops = {
.open = tracing_open_generic,
.read = tracing_max_lat_read,
@@ -3353,6 +3355,12 @@ static const struct file_operations tracing_mark_fops = {
.write = tracing_mark_write,
};
+static const struct file_operations trace_clock_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_clock_read,
+ .write = tracing_clock_write,
+};
+
struct ftrace_buffer_info {
struct trace_array *tr;
void *spare;
@@ -3633,9 +3641,6 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
cnt = ring_buffer_commit_overrun_cpu(tr->buffer, cpu);
trace_seq_printf(s, "commit overrun: %ld\n", cnt);
- cnt = ring_buffer_nmi_dropped_cpu(tr->buffer, cpu);
- trace_seq_printf(s, "nmi dropped: %ld\n", cnt);
-
count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len);
kfree(s);
@@ -4066,11 +4071,13 @@ static __init int tracer_init_debugfs(void)
trace_create_file("current_tracer", 0644, d_tracer,
&global_trace, &set_tracer_fops);
+#ifdef CONFIG_TRACER_MAX_TRACE
trace_create_file("tracing_max_latency", 0644, d_tracer,
&tracing_max_latency, &tracing_max_lat_fops);
trace_create_file("tracing_thresh", 0644, d_tracer,
&tracing_thresh, &tracing_max_lat_fops);
+#endif
trace_create_file("README", 0444, d_tracer,
NULL, &tracing_readme_fops);
@@ -4087,6 +4094,9 @@ static __init int tracer_init_debugfs(void)
trace_create_file("saved_cmdlines", 0444, d_tracer,
NULL, &tracing_saved_cmdlines_fops);
+ trace_create_file("trace_clock", 0644, d_tracer, NULL,
+ &trace_clock_fops);
+
#ifdef CONFIG_DYNAMIC_FTRACE
trace_create_file("dyn_ftrace_total_info", 0444, d_tracer,
&ftrace_update_tot_cnt, &tracing_dyn_info_fops);
@@ -4265,7 +4275,6 @@ void ftrace_dump(void)
__init static int tracer_alloc_buffers(void)
{
- struct trace_array_cpu *data;
int ring_buf_size;
int i;
int ret = -ENOMEM;
@@ -4315,7 +4324,7 @@ __init static int tracer_alloc_buffers(void)
/* Allocate the first page for all buffers */
for_each_tracing_cpu(i) {
- data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
+ global_trace.data[i] = &per_cpu(global_trace_cpu, i);
max_tr.data[i] = &per_cpu(max_data, i);
}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 8b9f4f6e9559..fa1dccb579d5 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -34,8 +34,6 @@ enum trace_type {
TRACE_GRAPH_ENT,
TRACE_USER_STACK,
TRACE_HW_BRANCHES,
- TRACE_SYSCALL_ENTER,
- TRACE_SYSCALL_EXIT,
TRACE_KMEM_ALLOC,
TRACE_KMEM_FREE,
TRACE_POWER,
@@ -236,9 +234,6 @@ struct trace_array_cpu {
atomic_t disabled;
void *buffer_page; /* ring buffer spare */
- /* these fields get copied into max-trace: */
- unsigned long trace_idx;
- unsigned long overrun;
unsigned long saved_latency;
unsigned long critical_start;
unsigned long critical_end;
@@ -246,6 +241,7 @@ struct trace_array_cpu {
unsigned long nice;
unsigned long policy;
unsigned long rt_priority;
+ unsigned long skipped_entries;
cycle_t preempt_timestamp;
pid_t pid;
uid_t uid;
@@ -319,10 +315,6 @@ extern void __ftrace_bad_type(void);
TRACE_KMEM_ALLOC); \
IF_ASSIGN(var, ent, struct kmemtrace_free_entry, \
TRACE_KMEM_FREE); \
- IF_ASSIGN(var, ent, struct syscall_trace_enter, \
- TRACE_SYSCALL_ENTER); \
- IF_ASSIGN(var, ent, struct syscall_trace_exit, \
- TRACE_SYSCALL_EXIT); \
__ftrace_bad_type(); \
} while (0)
@@ -423,12 +415,13 @@ void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
struct ring_buffer_event;
-struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
- int type,
- unsigned long len,
- unsigned long flags,
- int pc);
-void trace_buffer_unlock_commit(struct trace_array *tr,
+struct ring_buffer_event *
+trace_buffer_lock_reserve(struct ring_buffer *buffer,
+ int type,
+ unsigned long len,
+ unsigned long flags,
+ int pc);
+void trace_buffer_unlock_commit(struct ring_buffer *buffer,
struct ring_buffer_event *event,
unsigned long flags, int pc);
@@ -467,6 +460,7 @@ void trace_function(struct trace_array *tr,
void trace_graph_return(struct ftrace_graph_ret *trace);
int trace_graph_entry(struct ftrace_graph_ent *trace);
+void set_graph_array(struct trace_array *tr);
void tracing_start_cmdline_record(void);
void tracing_stop_cmdline_record(void);
@@ -478,16 +472,40 @@ void unregister_tracer(struct tracer *type);
extern unsigned long nsecs_to_usecs(unsigned long nsecs);
+#ifdef CONFIG_TRACER_MAX_TRACE
extern unsigned long tracing_max_latency;
extern unsigned long tracing_thresh;
void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
void update_max_tr_single(struct trace_array *tr,
struct task_struct *tsk, int cpu);
+#endif /* CONFIG_TRACER_MAX_TRACE */
-void __trace_stack(struct trace_array *tr,
- unsigned long flags,
- int skip, int pc);
+#ifdef CONFIG_STACKTRACE
+void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
+ int skip, int pc);
+
+void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
+ int pc);
+
+void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
+ int pc);
+#else
+static inline void ftrace_trace_stack(struct trace_array *tr,
+ unsigned long flags, int skip, int pc)
+{
+}
+
+static inline void ftrace_trace_userstack(struct trace_array *tr,
+ unsigned long flags, int pc)
+{
+}
+
+static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
+ int skip, int pc)
+{
+}
+#endif /* CONFIG_STACKTRACE */
extern cycle_t ftrace_now(int cpu);
@@ -513,6 +531,10 @@ extern unsigned long ftrace_update_tot_cnt;
extern int DYN_FTRACE_TEST_NAME(void);
#endif
+extern int ring_buffer_expanded;
+extern bool tracing_selftest_disabled;
+DECLARE_PER_CPU(local_t, ftrace_cpu_disabled);
+
#ifdef CONFIG_FTRACE_STARTUP_TEST
extern int trace_selftest_startup_function(struct tracer *trace,
struct trace_array *tr);
@@ -544,9 +566,16 @@ extern int
trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
extern int
trace_vprintk(unsigned long ip, const char *fmt, va_list args);
+extern int
+trace_array_vprintk(struct trace_array *tr,
+ unsigned long ip, const char *fmt, va_list args);
+int trace_array_printk(struct trace_array *tr,
+ unsigned long ip, const char *fmt, ...);
extern unsigned long trace_flags;
+extern int trace_clock_id;
+
/* Standard output formatting function used for function return traces */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
extern enum print_line_t print_graph_function(struct trace_iterator *iter);
@@ -635,9 +664,8 @@ enum trace_iterator_flags {
TRACE_ITER_PRINTK_MSGONLY = 0x10000,
TRACE_ITER_CONTEXT_INFO = 0x20000, /* Print pid/cpu/time */
TRACE_ITER_LATENCY_FMT = 0x40000,
- TRACE_ITER_GLOBAL_CLK = 0x80000,
- TRACE_ITER_SLEEP_TIME = 0x100000,
- TRACE_ITER_GRAPH_TIME = 0x200000,
+ TRACE_ITER_SLEEP_TIME = 0x80000,
+ TRACE_ITER_GRAPH_TIME = 0x100000,
};
/*
@@ -734,6 +762,7 @@ struct ftrace_event_field {
struct list_head link;
char *name;
char *type;
+ int filter_type;
int offset;
int size;
int is_signed;
@@ -743,13 +772,15 @@ struct event_filter {
int n_preds;
struct filter_pred **preds;
char *filter_string;
+ bool no_reset;
};
struct event_subsystem {
struct list_head list;
const char *name;
struct dentry *entry;
- void *filter;
+ struct event_filter *filter;
+ int nr_events;
};
struct filter_pred;
@@ -777,6 +808,7 @@ extern int apply_subsystem_event_filter(struct event_subsystem *system,
char *filter_string);
extern void print_subsystem_event_filter(struct event_subsystem *system,
struct trace_seq *s);
+extern int filter_assign_type(const char *type);
static inline int
filter_check_discard(struct ftrace_event_call *call, void *rec,
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index a29ef23ffb47..19bfc75d467e 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -41,14 +41,12 @@ void disable_boot_trace(void)
static int boot_trace_init(struct trace_array *tr)
{
- int cpu;
boot_trace = tr;
if (!tr)
return 0;
- for_each_cpu(cpu, cpu_possible_mask)
- tracing_reset(tr, cpu);
+ tracing_reset_online_cpus(tr);
tracing_sched_switch_assign_trace(tr);
return 0;
@@ -132,6 +130,7 @@ struct tracer boot_tracer __read_mostly =
void trace_boot_call(struct boot_trace_call *bt, initcall_t fn)
{
struct ring_buffer_event *event;
+ struct ring_buffer *buffer;
struct trace_boot_call *entry;
struct trace_array *tr = boot_trace;
@@ -144,13 +143,14 @@ void trace_boot_call(struct boot_trace_call *bt, initcall_t fn)
sprint_symbol(bt->func, (unsigned long)fn);
preempt_disable();
- event = trace_buffer_lock_reserve(tr, TRACE_BOOT_CALL,
+ buffer = tr->buffer;
+ event = trace_buffer_lock_reserve(buffer, TRACE_BOOT_CALL,
sizeof(*entry), 0, 0);
if (!event)
goto out;
entry = ring_buffer_event_data(event);
entry->boot_call = *bt;
- trace_buffer_unlock_commit(tr, event, 0, 0);
+ trace_buffer_unlock_commit(buffer, event, 0, 0);
out:
preempt_enable();
}
@@ -158,6 +158,7 @@ void trace_boot_call(struct boot_trace_call *bt, initcall_t fn)
void trace_boot_ret(struct boot_trace_ret *bt, initcall_t fn)
{
struct ring_buffer_event *event;
+ struct ring_buffer *buffer;
struct trace_boot_ret *entry;
struct trace_array *tr = boot_trace;
@@ -167,13 +168,14 @@ void trace_boot_ret(struct boot_trace_ret *bt, initcall_t fn)
sprint_symbol(bt->func, (unsigned long)fn);
preempt_disable();
- event = trace_buffer_lock_reserve(tr, TRACE_BOOT_RET,
+ buffer = tr->buffer;
+ event = trace_buffer_lock_reserve(buffer, TRACE_BOOT_RET,
sizeof(*entry), 0, 0);
if (!event)
goto out;
entry = ring_buffer_event_data(event);
entry->boot_ret = *bt;
- trace_buffer_unlock_commit(tr, event, 0, 0);
+ trace_buffer_unlock_commit(buffer, event, 0, 0);
out:
preempt_enable();
}
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index e75276a49cf5..78b1ed230177 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -17,6 +17,8 @@
#include <linux/ctype.h>
#include <linux/delay.h>
+#include <asm/setup.h>
+
#include "trace_output.h"
#define TRACE_SYSTEM "TRACE_SYSTEM"
@@ -25,8 +27,9 @@ DEFINE_MUTEX(event_mutex);
LIST_HEAD(ftrace_events);
-int trace_define_field(struct ftrace_event_call *call, char *type,
- char *name, int offset, int size, int is_signed)
+int trace_define_field(struct ftrace_event_call *call, const char *type,
+ const char *name, int offset, int size, int is_signed,
+ int filter_type)
{
struct ftrace_event_field *field;
@@ -42,9 +45,15 @@ int trace_define_field(struct ftrace_event_call *call, char *type,
if (!field->type)
goto err;
+ if (filter_type == FILTER_OTHER)
+ field->filter_type = filter_assign_type(type);
+ else
+ field->filter_type = filter_type;
+
field->offset = offset;
field->size = size;
field->is_signed = is_signed;
+
list_add(&field->link, &call->fields);
return 0;
@@ -60,6 +69,29 @@ err:
}
EXPORT_SYMBOL_GPL(trace_define_field);
+#define __common_field(type, item) \
+ ret = trace_define_field(call, #type, "common_" #item, \
+ offsetof(typeof(ent), item), \
+ sizeof(ent.item), \
+ is_signed_type(type), FILTER_OTHER); \
+ if (ret) \
+ return ret;
+
+int trace_define_common_fields(struct ftrace_event_call *call)
+{
+ int ret;
+ struct trace_entry ent;
+
+ __common_field(unsigned short, type);
+ __common_field(unsigned char, flags);
+ __common_field(unsigned char, preempt_count);
+ __common_field(int, pid);
+ __common_field(int, tgid);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(trace_define_common_fields);
+
#ifdef CONFIG_MODULES
static void trace_destroy_fields(struct ftrace_event_call *call)
@@ -84,14 +116,14 @@ static void ftrace_event_enable_disable(struct ftrace_event_call *call,
if (call->enabled) {
call->enabled = 0;
tracing_stop_cmdline_record();
- call->unregfunc();
+ call->unregfunc(call->data);
}
break;
case 1:
if (!call->enabled) {
call->enabled = 1;
tracing_start_cmdline_record();
- call->regfunc();
+ call->regfunc(call->data);
}
break;
}
@@ -574,7 +606,7 @@ event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
trace_seq_printf(s, "format:\n");
trace_write_header(s);
- r = call->show_format(s);
+ r = call->show_format(call, s);
if (!r) {
/*
* ug! The format output is bigger than a PAGE!!
@@ -849,8 +881,10 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
/* First see if we did not already create this dir */
list_for_each_entry(system, &event_subsystems, list) {
- if (strcmp(system->name, name) == 0)
+ if (strcmp(system->name, name) == 0) {
+ system->nr_events++;
return system->entry;
+ }
}
/* need to create new entry */
@@ -869,6 +903,7 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
return d_events;
}
+ system->nr_events = 1;
system->name = kstrdup(name, GFP_KERNEL);
if (!system->name) {
debugfs_remove(system->entry);
@@ -920,15 +955,6 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
if (strcmp(call->system, TRACE_SYSTEM) != 0)
d_events = event_subsystem_dir(call->system, d_events);
- if (call->raw_init) {
- ret = call->raw_init();
- if (ret < 0) {
- pr_warning("Could not initialize trace point"
- " events/%s\n", call->name);
- return ret;
- }
- }
-
call->dir = debugfs_create_dir(call->name, d_events);
if (!call->dir) {
pr_warning("Could not create debugfs "
@@ -945,7 +971,7 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
id);
if (call->define_fields) {
- ret = call->define_fields();
+ ret = call->define_fields(call);
if (ret < 0) {
pr_warning("Could not initialize trace point"
" events/%s\n", call->name);
@@ -987,6 +1013,32 @@ struct ftrace_module_file_ops {
struct file_operations filter;
};
+static void remove_subsystem_dir(const char *name)
+{
+ struct event_subsystem *system;
+
+ if (strcmp(name, TRACE_SYSTEM) == 0)
+ return;
+
+ list_for_each_entry(system, &event_subsystems, list) {
+ if (strcmp(system->name, name) == 0) {
+ if (!--system->nr_events) {
+ struct event_filter *filter = system->filter;
+
+ debugfs_remove_recursive(system->entry);
+ list_del(&system->list);
+ if (filter) {
+ kfree(filter->filter_string);
+ kfree(filter);
+ }
+ kfree(system->name);
+ kfree(system);
+ }
+ break;
+ }
+ }
+}
+
static struct ftrace_module_file_ops *
trace_create_file_ops(struct module *mod)
{
@@ -1027,6 +1079,7 @@ static void trace_module_add_events(struct module *mod)
struct ftrace_module_file_ops *file_ops = NULL;
struct ftrace_event_call *call, *start, *end;
struct dentry *d_events;
+ int ret;
start = mod->trace_events;
end = mod->trace_events + mod->num_trace_events;
@@ -1042,7 +1095,15 @@ static void trace_module_add_events(struct module *mod)
/* The linker may leave blanks */
if (!call->name)
continue;
-
+ if (call->raw_init) {
+ ret = call->raw_init();
+ if (ret < 0) {
+ if (ret != -ENOSYS)
+ pr_warning("Could not initialize trace "
+ "point events/%s\n", call->name);
+ continue;
+ }
+ }
/*
* This module has events, create file ops for this module
* if not already done.
@@ -1077,6 +1138,7 @@ static void trace_module_remove_events(struct module *mod)
list_del(&call->list);
trace_destroy_fields(call);
destroy_preds(call);
+ remove_subsystem_dir(call->system);
}
}
@@ -1133,6 +1195,18 @@ struct notifier_block trace_module_nb = {
extern struct ftrace_event_call __start_ftrace_events[];
extern struct ftrace_event_call __stop_ftrace_events[];
+static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
+
+static __init int setup_trace_event(char *str)
+{
+ strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
+ ring_buffer_expanded = 1;
+ tracing_selftest_disabled = 1;
+
+ return 1;
+}
+__setup("trace_event=", setup_trace_event);
+
static __init int event_trace_init(void)
{
struct ftrace_event_call *call;
@@ -1140,6 +1214,8 @@ static __init int event_trace_init(void)
struct dentry *entry;
struct dentry *d_events;
int ret;
+ char *buf = bootup_event_buf;
+ char *token;
d_tracer = tracing_init_dentry();
if (!d_tracer)
@@ -1179,12 +1255,34 @@ static __init int event_trace_init(void)
/* The linker may leave blanks */
if (!call->name)
continue;
+ if (call->raw_init) {
+ ret = call->raw_init();
+ if (ret < 0) {
+ if (ret != -ENOSYS)
+ pr_warning("Could not initialize trace "
+ "point events/%s\n", call->name);
+ continue;
+ }
+ }
list_add(&call->list, &ftrace_events);
event_create_dir(call, d_events, &ftrace_event_id_fops,
&ftrace_enable_fops, &ftrace_event_filter_fops,
&ftrace_event_format_fops);
}
+ while (true) {
+ token = strsep(&buf, ",");
+
+ if (!token)
+ break;
+ if (!*token)
+ continue;
+
+ ret = ftrace_set_clr_event(token, 1);
+ if (ret)
+ pr_warning("Failed to enable trace event: %s\n", token);
+ }
+
ret = register_module_notifier(&trace_module_nb);
if (ret)
pr_warning("Failed to register trace events module notifier\n");
@@ -1340,6 +1438,7 @@ static void
function_test_events_call(unsigned long ip, unsigned long parent_ip)
{
struct ring_buffer_event *event;
+ struct ring_buffer *buffer;
struct ftrace_entry *entry;
unsigned long flags;
long disabled;
@@ -1357,7 +1456,8 @@ function_test_events_call(unsigned long ip, unsigned long parent_ip)
local_save_flags(flags);
- event = trace_current_buffer_lock_reserve(TRACE_FN, sizeof(*entry),
+ event = trace_current_buffer_lock_reserve(&buffer,
+ TRACE_FN, sizeof(*entry),
flags, pc);
if (!event)
goto out;
@@ -1365,7 +1465,7 @@ function_test_events_call(unsigned long ip, unsigned long parent_ip)
entry->ip = ip;
entry->parent_ip = parent_ip;
- trace_nowake_buffer_unlock_commit(event, flags, pc);
+ trace_nowake_buffer_unlock_commit(buffer, event, flags, pc);
out:
atomic_dec(&per_cpu(test_event_disable, cpu));
@@ -1392,10 +1492,10 @@ static __init void event_trace_self_test_with_function(void)
static __init int event_trace_self_tests_init(void)
{
-
- event_trace_self_tests();
-
- event_trace_self_test_with_function();
+ if (!tracing_selftest_disabled) {
+ event_trace_self_tests();
+ event_trace_self_test_with_function();
+ }
return 0;
}
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index f32dc9d1ea7b..93660fbbf629 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -163,6 +163,20 @@ static int filter_pred_string(struct filter_pred *pred, void *event,
return match;
}
+/* Filter predicate for char * pointers */
+static int filter_pred_pchar(struct filter_pred *pred, void *event,
+ int val1, int val2)
+{
+ char **addr = (char **)(event + pred->offset);
+ int cmp, match;
+
+ cmp = strncmp(*addr, pred->str_val, pred->str_len);
+
+ match = (!cmp) ^ pred->not;
+
+ return match;
+}
+
/*
* Filter predicate for dynamic sized arrays of characters.
* These are implemented through a list of strings at the end
@@ -176,11 +190,13 @@ static int filter_pred_string(struct filter_pred *pred, void *event,
static int filter_pred_strloc(struct filter_pred *pred, void *event,
int val1, int val2)
{
- unsigned short str_loc = *(unsigned short *)(event + pred->offset);
+ u32 str_item = *(u32 *)(event + pred->offset);
+ int str_loc = str_item & 0xffff;
+ int str_len = str_item >> 16;
char *addr = (char *)(event + str_loc);
int cmp, match;
- cmp = strncmp(addr, pred->str_val, pred->str_len);
+ cmp = strncmp(addr, pred->str_val, str_len);
match = (!cmp) ^ pred->not;
@@ -293,7 +309,7 @@ void print_event_filter(struct ftrace_event_call *call, struct trace_seq *s)
struct event_filter *filter = call->filter;
mutex_lock(&event_mutex);
- if (filter->filter_string)
+ if (filter && filter->filter_string)
trace_seq_printf(s, "%s\n", filter->filter_string);
else
trace_seq_printf(s, "none\n");
@@ -306,7 +322,7 @@ void print_subsystem_event_filter(struct event_subsystem *system,
struct event_filter *filter = system->filter;
mutex_lock(&event_mutex);
- if (filter->filter_string)
+ if (filter && filter->filter_string)
trace_seq_printf(s, "%s\n", filter->filter_string);
else
trace_seq_printf(s, "none\n");
@@ -374,6 +390,9 @@ void destroy_preds(struct ftrace_event_call *call)
struct event_filter *filter = call->filter;
int i;
+ if (!filter)
+ return;
+
for (i = 0; i < MAX_FILTER_PRED; i++) {
if (filter->preds[i])
filter_free_pred(filter->preds[i]);
@@ -384,17 +403,19 @@ void destroy_preds(struct ftrace_event_call *call)
call->filter = NULL;
}
-int init_preds(struct ftrace_event_call *call)
+static int init_preds(struct ftrace_event_call *call)
{
struct event_filter *filter;
struct filter_pred *pred;
int i;
+ if (call->filter)
+ return 0;
+
filter = call->filter = kzalloc(sizeof(*filter), GFP_KERNEL);
if (!call->filter)
return -ENOMEM;
- call->filter_active = 0;
filter->n_preds = 0;
filter->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred), GFP_KERNEL);
@@ -416,30 +437,55 @@ oom:
return -ENOMEM;
}
-EXPORT_SYMBOL_GPL(init_preds);
-static void filter_free_subsystem_preds(struct event_subsystem *system)
+static int init_subsystem_preds(struct event_subsystem *system)
{
- struct event_filter *filter = system->filter;
struct ftrace_event_call *call;
- int i;
+ int err;
- if (filter->n_preds) {
- for (i = 0; i < filter->n_preds; i++)
- filter_free_pred(filter->preds[i]);
- kfree(filter->preds);
- filter->preds = NULL;
- filter->n_preds = 0;
+ list_for_each_entry(call, &ftrace_events, list) {
+ if (!call->define_fields)
+ continue;
+
+ if (strcmp(call->system, system->name) != 0)
+ continue;
+
+ err = init_preds(call);
+ if (err)
+ return err;
}
+ return 0;
+}
+
+enum {
+ FILTER_DISABLE_ALL,
+ FILTER_INIT_NO_RESET,
+ FILTER_SKIP_NO_RESET,
+};
+
+static void filter_free_subsystem_preds(struct event_subsystem *system,
+ int flag)
+{
+ struct ftrace_event_call *call;
+
list_for_each_entry(call, &ftrace_events, list) {
if (!call->define_fields)
continue;
- if (!strcmp(call->system, system->name)) {
- filter_disable_preds(call);
- remove_filter_string(call->filter);
+ if (strcmp(call->system, system->name) != 0)
+ continue;
+
+ if (flag == FILTER_INIT_NO_RESET) {
+ call->filter->no_reset = false;
+ continue;
}
+
+ if (flag == FILTER_SKIP_NO_RESET && call->filter->no_reset)
+ continue;
+
+ filter_disable_preds(call);
+ remove_filter_string(call->filter);
}
}
@@ -468,12 +514,7 @@ static int filter_add_pred_fn(struct filter_parse_state *ps,
return 0;
}
-enum {
- FILTER_STATIC_STRING = 1,
- FILTER_DYN_STRING
-};
-
-static int is_string_field(const char *type)
+int filter_assign_type(const char *type)
{
if (strstr(type, "__data_loc") && strstr(type, "char"))
return FILTER_DYN_STRING;
@@ -481,12 +522,19 @@ static int is_string_field(const char *type)
if (strchr(type, '[') && strstr(type, "char"))
return FILTER_STATIC_STRING;
- return 0;
+ return FILTER_OTHER;
+}
+
+static bool is_string_field(struct ftrace_event_field *field)
+{
+ return field->filter_type == FILTER_DYN_STRING ||
+ field->filter_type == FILTER_STATIC_STRING ||
+ field->filter_type == FILTER_PTR_STRING;
}
static int is_legal_op(struct ftrace_event_field *field, int op)
{
- if (is_string_field(field->type) && (op != OP_EQ && op != OP_NE))
+ if (is_string_field(field) && (op != OP_EQ && op != OP_NE))
return 0;
return 1;
@@ -537,22 +585,24 @@ static filter_pred_fn_t select_comparison_fn(int op, int field_size,
static int filter_add_pred(struct filter_parse_state *ps,
struct ftrace_event_call *call,
- struct filter_pred *pred)
+ struct filter_pred *pred,
+ bool dry_run)
{
struct ftrace_event_field *field;
filter_pred_fn_t fn;
unsigned long long val;
- int string_type;
int ret;
pred->fn = filter_pred_none;
if (pred->op == OP_AND) {
pred->pop_n = 2;
- return filter_add_pred_fn(ps, call, pred, filter_pred_and);
+ fn = filter_pred_and;
+ goto add_pred_fn;
} else if (pred->op == OP_OR) {
pred->pop_n = 2;
- return filter_add_pred_fn(ps, call, pred, filter_pred_or);
+ fn = filter_pred_or;
+ goto add_pred_fn;
}
field = find_event_field(call, pred->field_name);
@@ -568,16 +618,17 @@ static int filter_add_pred(struct filter_parse_state *ps,
return -EINVAL;
}
- string_type = is_string_field(field->type);
- if (string_type) {
- if (string_type == FILTER_STATIC_STRING)
+ if (is_string_field(field)) {
+ pred->str_len = field->size;
+
+ if (field->filter_type == FILTER_STATIC_STRING)
fn = filter_pred_string;
- else
+ else if (field->filter_type == FILTER_DYN_STRING)
fn = filter_pred_strloc;
- pred->str_len = field->size;
- if (pred->op == OP_NE)
- pred->not = 1;
- return filter_add_pred_fn(ps, call, pred, fn);
+ else {
+ fn = filter_pred_pchar;
+ pred->str_len = strlen(pred->str_val);
+ }
} else {
if (field->is_signed)
ret = strict_strtoll(pred->str_val, 0, &val);
@@ -588,41 +639,33 @@ static int filter_add_pred(struct filter_parse_state *ps,
return -EINVAL;
}
pred->val = val;
- }
- fn = select_comparison_fn(pred->op, field->size, field->is_signed);
- if (!fn) {
- parse_error(ps, FILT_ERR_INVALID_OP, 0);
- return -EINVAL;
+ fn = select_comparison_fn(pred->op, field->size,
+ field->is_signed);
+ if (!fn) {
+ parse_error(ps, FILT_ERR_INVALID_OP, 0);
+ return -EINVAL;
+ }
}
if (pred->op == OP_NE)
pred->not = 1;
- return filter_add_pred_fn(ps, call, pred, fn);
+add_pred_fn:
+ if (!dry_run)
+ return filter_add_pred_fn(ps, call, pred, fn);
+ return 0;
}
static int filter_add_subsystem_pred(struct filter_parse_state *ps,
struct event_subsystem *system,
struct filter_pred *pred,
- char *filter_string)
+ char *filter_string,
+ bool dry_run)
{
- struct event_filter *filter = system->filter;
struct ftrace_event_call *call;
int err = 0;
-
- if (!filter->preds) {
- filter->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred),
- GFP_KERNEL);
-
- if (!filter->preds)
- return -ENOMEM;
- }
-
- if (filter->n_preds == MAX_FILTER_PRED) {
- parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
- return -ENOSPC;
- }
+ bool fail = true;
list_for_each_entry(call, &ftrace_events, list) {
@@ -632,19 +675,24 @@ static int filter_add_subsystem_pred(struct filter_parse_state *ps,
if (strcmp(call->system, system->name))
continue;
- err = filter_add_pred(ps, call, pred);
- if (err) {
- filter_free_subsystem_preds(system);
- parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
- goto out;
- }
- replace_filter_string(call->filter, filter_string);
+ if (call->filter->no_reset)
+ continue;
+
+ err = filter_add_pred(ps, call, pred, dry_run);
+ if (err)
+ call->filter->no_reset = true;
+ else
+ fail = false;
+
+ if (!dry_run)
+ replace_filter_string(call->filter, filter_string);
}
- filter->preds[filter->n_preds] = pred;
- filter->n_preds++;
-out:
- return err;
+ if (fail) {
+ parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
+ return err;
+ }
+ return 0;
}
static void parse_init(struct filter_parse_state *ps,
@@ -1003,12 +1051,14 @@ static int check_preds(struct filter_parse_state *ps)
static int replace_preds(struct event_subsystem *system,
struct ftrace_event_call *call,
struct filter_parse_state *ps,
- char *filter_string)
+ char *filter_string,
+ bool dry_run)
{
char *operand1 = NULL, *operand2 = NULL;
struct filter_pred *pred;
struct postfix_elt *elt;
int err;
+ int n_preds = 0;
err = check_preds(ps);
if (err)
@@ -1027,24 +1077,14 @@ static int replace_preds(struct event_subsystem *system,
continue;
}
+ if (n_preds++ == MAX_FILTER_PRED) {
+ parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
+ return -ENOSPC;
+ }
+
if (elt->op == OP_AND || elt->op == OP_OR) {
pred = create_logical_pred(elt->op);
- if (!pred)
- return -ENOMEM;
- if (call) {
- err = filter_add_pred(ps, call, pred);
- filter_free_pred(pred);
- } else {
- err = filter_add_subsystem_pred(ps, system,
- pred, filter_string);
- if (err)
- filter_free_pred(pred);
- }
- if (err)
- return err;
-
- operand1 = operand2 = NULL;
- continue;
+ goto add_pred;
}
if (!operand1 || !operand2) {
@@ -1053,17 +1093,15 @@ static int replace_preds(struct event_subsystem *system,
}
pred = create_pred(elt->op, operand1, operand2);
+add_pred:
if (!pred)
return -ENOMEM;
- if (call) {
- err = filter_add_pred(ps, call, pred);
- filter_free_pred(pred);
- } else {
+ if (call)
+ err = filter_add_pred(ps, call, pred, false);
+ else
err = filter_add_subsystem_pred(ps, system, pred,
- filter_string);
- if (err)
- filter_free_pred(pred);
- }
+ filter_string, dry_run);
+ filter_free_pred(pred);
if (err)
return err;
@@ -1081,6 +1119,10 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
mutex_lock(&event_mutex);
+ err = init_preds(call);
+ if (err)
+ goto out_unlock;
+
if (!strcmp(strstrip(filter_string), "0")) {
filter_disable_preds(call);
remove_filter_string(call->filter);
@@ -1103,7 +1145,7 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string)
goto out;
}
- err = replace_preds(NULL, call, ps, filter_string);
+ err = replace_preds(NULL, call, ps, filter_string, false);
if (err)
append_filter_err(ps, call->filter);
@@ -1126,8 +1168,12 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
mutex_lock(&event_mutex);
+ err = init_subsystem_preds(system);
+ if (err)
+ goto out_unlock;
+
if (!strcmp(strstrip(filter_string), "0")) {
- filter_free_subsystem_preds(system);
+ filter_free_subsystem_preds(system, FILTER_DISABLE_ALL);
remove_filter_string(system->filter);
mutex_unlock(&event_mutex);
return 0;
@@ -1138,7 +1184,6 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
if (!ps)
goto out_unlock;
- filter_free_subsystem_preds(system);
replace_filter_string(system->filter, filter_string);
parse_init(ps, filter_ops, filter_string);
@@ -1148,9 +1193,23 @@ int apply_subsystem_event_filter(struct event_subsystem *system,
goto out;
}
- err = replace_preds(system, NULL, ps, filter_string);
- if (err)
+ filter_free_subsystem_preds(system, FILTER_INIT_NO_RESET);
+
+ /* try to see the filter can be applied to which events */
+ err = replace_preds(system, NULL, ps, filter_string, true);
+ if (err) {
append_filter_err(ps, system->filter);
+ goto out;
+ }
+
+ filter_free_subsystem_preds(system, FILTER_SKIP_NO_RESET);
+
+ /* really apply the filter to the events */
+ err = replace_preds(system, NULL, ps, filter_string, false);
+ if (err) {
+ append_filter_err(ps, system->filter);
+ filter_free_subsystem_preds(system, 2);
+ }
out:
filter_opstack_clear(ps);
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index d06cf898dc86..df1bf6e48bb9 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -60,7 +60,8 @@ extern void __bad_type_size(void);
#undef TRACE_EVENT_FORMAT
#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \
static int \
-ftrace_format_##call(struct trace_seq *s) \
+ftrace_format_##call(struct ftrace_event_call *unused, \
+ struct trace_seq *s) \
{ \
struct args field; \
int ret; \
@@ -76,7 +77,8 @@ ftrace_format_##call(struct trace_seq *s) \
#define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, \
tpfmt) \
static int \
-ftrace_format_##call(struct trace_seq *s) \
+ftrace_format_##call(struct ftrace_event_call *unused, \
+ struct trace_seq *s) \
{ \
struct args field; \
int ret; \
@@ -117,7 +119,7 @@ ftrace_format_##call(struct trace_seq *s) \
#undef TRACE_EVENT_FORMAT
#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \
-int ftrace_define_fields_##call(void); \
+int ftrace_define_fields_##call(struct ftrace_event_call *event_call); \
static int ftrace_raw_init_event_##call(void); \
\
struct ftrace_event_call __used \
@@ -133,7 +135,6 @@ __attribute__((section("_ftrace_events"))) event_##call = { \
static int ftrace_raw_init_event_##call(void) \
{ \
INIT_LIST_HEAD(&event_##call.fields); \
- init_preds(&event_##call); \
return 0; \
} \
@@ -156,7 +157,8 @@ __attribute__((section("_ftrace_events"))) event_##call = { \
#define TRACE_FIELD(type, item, assign) \
ret = trace_define_field(event_call, #type, #item, \
offsetof(typeof(field), item), \
- sizeof(field.item), is_signed_type(type)); \
+ sizeof(field.item), \
+ is_signed_type(type), FILTER_OTHER); \
if (ret) \
return ret;
@@ -164,7 +166,7 @@ __attribute__((section("_ftrace_events"))) event_##call = { \
#define TRACE_FIELD_SPECIAL(type, item, len, cmd) \
ret = trace_define_field(event_call, #type "[" #len "]", #item, \
offsetof(typeof(field), item), \
- sizeof(field.item), 0); \
+ sizeof(field.item), 0, FILTER_OTHER); \
if (ret) \
return ret;
@@ -172,7 +174,8 @@ __attribute__((section("_ftrace_events"))) event_##call = { \
#define TRACE_FIELD_SIGN(type, item, assign, is_signed) \
ret = trace_define_field(event_call, #type, #item, \
offsetof(typeof(field), item), \
- sizeof(field.item), is_signed); \
+ sizeof(field.item), is_signed, \
+ FILTER_OTHER); \
if (ret) \
return ret;
@@ -182,17 +185,14 @@ __attribute__((section("_ftrace_events"))) event_##call = { \
#undef TRACE_EVENT_FORMAT
#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \
int \
-ftrace_define_fields_##call(void) \
+ftrace_define_fields_##call(struct ftrace_event_call *event_call) \
{ \
- struct ftrace_event_call *event_call = &event_##call; \
struct args field; \
int ret; \
\
- __common_field(unsigned char, type, 0); \
- __common_field(unsigned char, flags, 0); \
- __common_field(unsigned char, preempt_count, 0); \
- __common_field(int, pid, 1); \
- __common_field(int, tgid, 1); \
+ ret = trace_define_common_fields(event_call); \
+ if (ret) \
+ return ret; \
\
tstruct; \
\
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 75ef000613c3..5b01b94518fc 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -288,11 +288,9 @@ static int
ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
struct ftrace_probe_ops *ops, void *data)
{
- char str[KSYM_SYMBOL_LEN];
long count = (long)data;
- kallsyms_lookup(ip, NULL, NULL, NULL, str);
- seq_printf(m, "%s:", str);
+ seq_printf(m, "%pf:", (void *)ip);
if (ops == &traceon_probe_ops)
seq_printf(m, "traceon");
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 420ec3487579..b3749a2c3132 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -52,7 +52,7 @@ static struct tracer_flags tracer_flags = {
.opts = trace_opts
};
-/* pid on the last trace processed */
+static struct trace_array *graph_array;
/* Add a function return address to the trace stack on thread info.*/
@@ -166,10 +166,123 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
return ret;
}
+static int __trace_graph_entry(struct trace_array *tr,
+ struct ftrace_graph_ent *trace,
+ unsigned long flags,
+ int pc)
+{
+ struct ftrace_event_call *call = &event_funcgraph_entry;
+ struct ring_buffer_event *event;
+ struct ring_buffer *buffer = tr->buffer;
+ struct ftrace_graph_ent_entry *entry;
+
+ if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+ return 0;
+
+ event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
+ sizeof(*entry), flags, pc);
+ if (!event)
+ return 0;
+ entry = ring_buffer_event_data(event);
+ entry->graph_ent = *trace;
+ if (!filter_current_check_discard(buffer, call, entry, event))
+ ring_buffer_unlock_commit(buffer, event);
+
+ return 1;
+}
+
+int trace_graph_entry(struct ftrace_graph_ent *trace)
+{
+ struct trace_array *tr = graph_array;
+ struct trace_array_cpu *data;
+ unsigned long flags;
+ long disabled;
+ int ret;
+ int cpu;
+ int pc;
+
+ if (unlikely(!tr))
+ return 0;
+
+ if (!ftrace_trace_task(current))
+ return 0;
+
+ if (!ftrace_graph_addr(trace->func))
+ return 0;
+
+ local_irq_save(flags);
+ cpu = raw_smp_processor_id();
+ data = tr->data[cpu];
+ disabled = atomic_inc_return(&data->disabled);
+ if (likely(disabled == 1)) {
+ pc = preempt_count();
+ ret = __trace_graph_entry(tr, trace, flags, pc);
+ } else {
+ ret = 0;
+ }
+ /* Only do the atomic if it is not already set */
+ if (!test_tsk_trace_graph(current))
+ set_tsk_trace_graph(current);
+
+ atomic_dec(&data->disabled);
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+static void __trace_graph_return(struct trace_array *tr,
+ struct ftrace_graph_ret *trace,
+ unsigned long flags,
+ int pc)
+{
+ struct ftrace_event_call *call = &event_funcgraph_exit;
+ struct ring_buffer_event *event;
+ struct ring_buffer *buffer = tr->buffer;
+ struct ftrace_graph_ret_entry *entry;
+
+ if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+ return;
+
+ event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
+ sizeof(*entry), flags, pc);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ entry->ret = *trace;
+ if (!filter_current_check_discard(buffer, call, entry, event))
+ ring_buffer_unlock_commit(buffer, event);
+}
+
+void trace_graph_return(struct ftrace_graph_ret *trace)
+{
+ struct trace_array *tr = graph_array;
+ struct trace_array_cpu *data;
+ unsigned long flags;
+ long disabled;
+ int cpu;
+ int pc;
+
+ local_irq_save(flags);
+ cpu = raw_smp_processor_id();
+ data = tr->data[cpu];
+ disabled = atomic_inc_return(&data->disabled);
+ if (likely(disabled == 1)) {
+ pc = preempt_count();
+ __trace_graph_return(tr, trace, flags, pc);
+ }
+ if (!trace->depth)
+ clear_tsk_trace_graph(current);
+ atomic_dec(&data->disabled);
+ local_irq_restore(flags);
+}
+
static int graph_trace_init(struct trace_array *tr)
{
- int ret = register_ftrace_graph(&trace_graph_return,
- &trace_graph_entry);
+ int ret;
+
+ graph_array = tr;
+ ret = register_ftrace_graph(&trace_graph_return,
+ &trace_graph_entry);
if (ret)
return ret;
tracing_start_cmdline_record();
@@ -177,49 +290,30 @@ static int graph_trace_init(struct trace_array *tr)
return 0;
}
+void set_graph_array(struct trace_array *tr)
+{
+ graph_array = tr;
+}
+
static void graph_trace_reset(struct trace_array *tr)
{
tracing_stop_cmdline_record();
unregister_ftrace_graph();
}
-static inline int log10_cpu(int nb)
-{
- if (nb / 100)
- return 3;
- if (nb / 10)
- return 2;
- return 1;
-}
+static int max_bytes_for_cpu;
static enum print_line_t
print_graph_cpu(struct trace_seq *s, int cpu)
{
- int i;
int ret;
- int log10_this = log10_cpu(cpu);
- int log10_all = log10_cpu(cpumask_weight(cpu_online_mask));
-
/*
* Start with a space character - to make it stand out
* to the right a bit when trace output is pasted into
* email:
*/
- ret = trace_seq_printf(s, " ");
-
- /*
- * Tricky - we space the CPU field according to the max
- * number of online CPUs. On a 2-cpu system it would take
- * a maximum of 1 digit - on a 128 cpu system it would
- * take up to 3 digits:
- */
- for (i = 0; i < log10_all - log10_this; i++) {
- ret = trace_seq_printf(s, " ");
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
- }
- ret = trace_seq_printf(s, "%d) ", cpu);
+ ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -565,11 +659,7 @@ print_graph_entry_leaf(struct trace_iterator *iter,
return TRACE_TYPE_PARTIAL_LINE;
}
- ret = seq_print_ip_sym(s, call->func, 0);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
-
- ret = trace_seq_printf(s, "();\n");
+ ret = trace_seq_printf(s, "%pf();\n", (void *)call->func);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -612,11 +702,7 @@ print_graph_entry_nested(struct trace_iterator *iter,
return TRACE_TYPE_PARTIAL_LINE;
}
- ret = seq_print_ip_sym(s, call->func, 0);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
-
- ret = trace_seq_printf(s, "() {\n");
+ ret = trace_seq_printf(s, "%pf() {\n", (void *)call->func);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -934,6 +1020,8 @@ static struct tracer graph_trace __read_mostly = {
static __init int init_graph_trace(void)
{
+ max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
+
return register_tracer(&graph_trace);
}
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index b923d13e2fad..5555b75a0d12 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -178,7 +178,6 @@ out_unlock:
out:
data->critical_sequence = max_sequence;
data->preempt_timestamp = ftrace_now(cpu);
- tracing_reset(tr, cpu);
trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
}
@@ -208,7 +207,6 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip)
data->critical_sequence = max_sequence;
data->preempt_timestamp = ftrace_now(cpu);
data->critical_start = parent_ip ? : ip;
- tracing_reset(tr, cpu);
local_save_flags(flags);
@@ -379,6 +377,7 @@ static void __irqsoff_tracer_init(struct trace_array *tr)
irqsoff_trace = tr;
/* make sure that the tracer is visible */
smp_wmb();
+ tracing_reset_online_cpus(tr);
start_irqsoff_tracer(tr);
}
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index d53b45ed0806..c4c9bbda53d3 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -307,11 +307,12 @@ static void __trace_mmiotrace_rw(struct trace_array *tr,
struct trace_array_cpu *data,
struct mmiotrace_rw *rw)
{
+ struct ring_buffer *buffer = tr->buffer;
struct ring_buffer_event *event;
struct trace_mmiotrace_rw *entry;
int pc = preempt_count();
- event = trace_buffer_lock_reserve(tr, TRACE_MMIO_RW,
+ event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_RW,
sizeof(*entry), 0, pc);
if (!event) {
atomic_inc(&dropped_count);
@@ -319,7 +320,7 @@ static void __trace_mmiotrace_rw(struct trace_array *tr,
}
entry = ring_buffer_event_data(event);
entry->rw = *rw;
- trace_buffer_unlock_commit(tr, event, 0, pc);
+ trace_buffer_unlock_commit(buffer, event, 0, pc);
}
void mmio_trace_rw(struct mmiotrace_rw *rw)
@@ -333,11 +334,12 @@ static void __trace_mmiotrace_map(struct trace_array *tr,
struct trace_array_cpu *data,
struct mmiotrace_map *map)
{
+ struct ring_buffer *buffer = tr->buffer;
struct ring_buffer_event *event;
struct trace_mmiotrace_map *entry;
int pc = preempt_count();
- event = trace_buffer_lock_reserve(tr, TRACE_MMIO_MAP,
+ event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_MAP,
sizeof(*entry), 0, pc);
if (!event) {
atomic_inc(&dropped_count);
@@ -345,7 +347,7 @@ static void __trace_mmiotrace_map(struct trace_array *tr,
}
entry = ring_buffer_event_data(event);
entry->map = *map;
- trace_buffer_unlock_commit(tr, event, 0, pc);
+ trace_buffer_unlock_commit(buffer, event, 0, pc);
}
void mmio_trace_mapping(struct mmiotrace_map *map)
diff --git a/kernel/trace/trace_power.c b/kernel/trace/trace_power.c
index 8a30d9874cd4..fe1a00f1445a 100644
--- a/kernel/trace/trace_power.c
+++ b/kernel/trace/trace_power.c
@@ -38,6 +38,7 @@ static void probe_power_end(struct power_trace *it)
{
struct ftrace_event_call *call = &event_power;
struct ring_buffer_event *event;
+ struct ring_buffer *buffer;
struct trace_power *entry;
struct trace_array_cpu *data;
struct trace_array *tr = power_trace;
@@ -45,18 +46,20 @@ static void probe_power_end(struct power_trace *it)
if (!trace_power_enabled)
return;
+ buffer = tr->buffer;
+
preempt_disable();
it->end = ktime_get();
data = tr->data[smp_processor_id()];
- event = trace_buffer_lock_reserve(tr, TRACE_POWER,
+ event = trace_buffer_lock_reserve(buffer, TRACE_POWER,
sizeof(*entry), 0, 0);
if (!event)
goto out;
entry = ring_buffer_event_data(event);
entry->state_data = *it;
- if (!filter_check_discard(call, entry, tr->buffer, event))
- trace_buffer_unlock_commit(tr, event, 0, 0);
+ if (!filter_check_discard(call, entry, buffer, event))
+ trace_buffer_unlock_commit(buffer, event, 0, 0);
out:
preempt_enable();
}
@@ -66,6 +69,7 @@ static void probe_power_mark(struct power_trace *it, unsigned int type,
{
struct ftrace_event_call *call = &event_power;
struct ring_buffer_event *event;
+ struct ring_buffer *buffer;
struct trace_power *entry;
struct trace_array_cpu *data;
struct trace_array *tr = power_trace;
@@ -73,6 +77,8 @@ static void probe_power_mark(struct power_trace *it, unsigned int type,
if (!trace_power_enabled)
return;
+ buffer = tr->buffer;
+
memset(it, 0, sizeof(struct power_trace));
it->state = level;
it->type = type;
@@ -81,14 +87,14 @@ static void probe_power_mark(struct power_trace *it, unsigned int type,
it->end = it->stamp;
data = tr->data[smp_processor_id()];
- event = trace_buffer_lock_reserve(tr, TRACE_POWER,
+ event = trace_buffer_lock_reserve(buffer, TRACE_POWER,
sizeof(*entry), 0, 0);
if (!event)
goto out;
entry = ring_buffer_event_data(event);
entry->state_data = *it;
- if (!filter_check_discard(call, entry, tr->buffer, event))
- trace_buffer_unlock_commit(tr, event, 0, 0);
+ if (!filter_check_discard(call, entry, buffer, event))
+ trace_buffer_unlock_commit(buffer, event, 0, 0);
out:
preempt_enable();
}
@@ -144,14 +150,12 @@ static void power_trace_reset(struct trace_array *tr)
static int power_trace_init(struct trace_array *tr)
{
- int cpu;
power_trace = tr;
trace_power_enabled = 1;
tracing_power_register();
- for_each_cpu(cpu, cpu_possible_mask)
- tracing_reset(tr, cpu);
+ tracing_reset_online_cpus(tr);
return 0;
}
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index a98106dd979c..5fca0f51fde4 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -20,6 +20,35 @@ static int sched_ref;
static DEFINE_MUTEX(sched_register_mutex);
static int sched_stopped;
+
+void
+tracing_sched_switch_trace(struct trace_array *tr,
+ struct task_struct *prev,
+ struct task_struct *next,
+ unsigned long flags, int pc)
+{
+ struct ftrace_event_call *call = &event_context_switch;
+ struct ring_buffer *buffer = tr->buffer;
+ struct ring_buffer_event *event;
+ struct ctx_switch_entry *entry;
+
+ event = trace_buffer_lock_reserve(buffer, TRACE_CTX,
+ sizeof(*entry), flags, pc);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ entry->prev_pid = prev->pid;
+ entry->prev_prio = prev->prio;
+ entry->prev_state = prev->state;
+ entry->next_pid = next->pid;
+ entry->next_prio = next->prio;
+ entry->next_state = next->state;
+ entry->next_cpu = task_cpu(next);
+
+ if (!filter_check_discard(call, entry, buffer, event))
+ trace_buffer_unlock_commit(buffer, event, flags, pc);
+}
+
static void
probe_sched_switch(struct rq *__rq, struct task_struct *prev,
struct task_struct *next)
@@ -49,6 +78,36 @@ probe_sched_switch(struct rq *__rq, struct task_struct *prev,
local_irq_restore(flags);
}
+void
+tracing_sched_wakeup_trace(struct trace_array *tr,
+ struct task_struct *wakee,
+ struct task_struct *curr,
+ unsigned long flags, int pc)
+{
+ struct ftrace_event_call *call = &event_wakeup;
+ struct ring_buffer_event *event;
+ struct ctx_switch_entry *entry;
+ struct ring_buffer *buffer = tr->buffer;
+
+ event = trace_buffer_lock_reserve(buffer, TRACE_WAKE,
+ sizeof(*entry), flags, pc);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ entry->prev_pid = curr->pid;
+ entry->prev_prio = curr->prio;
+ entry->prev_state = curr->state;
+ entry->next_pid = wakee->pid;
+ entry->next_prio = wakee->prio;
+ entry->next_state = wakee->state;
+ entry->next_cpu = task_cpu(wakee);
+
+ if (!filter_check_discard(call, entry, buffer, event))
+ ring_buffer_unlock_commit(buffer, event);
+ ftrace_trace_stack(tr->buffer, flags, 6, pc);
+ ftrace_trace_userstack(tr->buffer, flags, pc);
+}
+
static void
probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee, int success)
{
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index eacb27225173..ad69f105a7c6 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -186,11 +186,6 @@ out:
static void __wakeup_reset(struct trace_array *tr)
{
- int cpu;
-
- for_each_possible_cpu(cpu)
- tracing_reset(tr, cpu);
-
wakeup_cpu = -1;
wakeup_prio = -1;
@@ -204,6 +199,8 @@ static void wakeup_reset(struct trace_array *tr)
{
unsigned long flags;
+ tracing_reset_online_cpus(tr);
+
local_irq_save(flags);
__raw_spin_lock(&wakeup_lock);
__wakeup_reset(tr);
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 00dd6485bdd7..d2cdbabb4ead 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -288,6 +288,7 @@ trace_selftest_startup_function_graph(struct tracer *trace,
* to detect and recover from possible hangs
*/
tracing_reset_online_cpus(tr);
+ set_graph_array(tr);
ret = register_ftrace_graph(&trace_graph_return,
&trace_graph_entry_watchdog);
if (ret) {
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 6a2a9d484cd6..0f6facb050a1 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -186,43 +186,33 @@ static const struct file_operations stack_max_size_fops = {
};
static void *
-t_next(struct seq_file *m, void *v, loff_t *pos)
+__next(struct seq_file *m, loff_t *pos)
{
- long i;
+ long n = *pos - 1;
- (*pos)++;
-
- if (v == SEQ_START_TOKEN)
- i = 0;
- else {
- i = *(long *)v;
- i++;
- }
-
- if (i >= max_stack_trace.nr_entries ||
- stack_dump_trace[i] == ULONG_MAX)
+ if (n >= max_stack_trace.nr_entries || stack_dump_trace[n] == ULONG_MAX)
return NULL;
- m->private = (void *)i;
-
+ m->private = (void *)n;
return &m->private;
}
-static void *t_start(struct seq_file *m, loff_t *pos)
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
{
- void *t = SEQ_START_TOKEN;
- loff_t l = 0;
+ (*pos)++;
+ return __next(m, pos);
+}
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
local_irq_disable();
__raw_spin_lock(&max_stack_lock);
if (*pos == 0)
return SEQ_START_TOKEN;
- for (; t && l < *pos; t = t_next(m, t, &l))
- ;
-
- return t;
+ return __next(m, pos);
}
static void t_stop(struct seq_file *m, void *p)
@@ -234,15 +224,8 @@ static void t_stop(struct seq_file *m, void *p)
static int trace_lookup_stack(struct seq_file *m, long i)
{
unsigned long addr = stack_dump_trace[i];
-#ifdef CONFIG_KALLSYMS
- char str[KSYM_SYMBOL_LEN];
-
- sprint_symbol(str, addr);
- return seq_printf(m, "%s\n", str);
-#else
- return seq_printf(m, "%p\n", (void*)addr);
-#endif
+ return seq_printf(m, "%pF\n", (void *)addr);
}
static void print_disabled(struct seq_file *m)
diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c
index aea321c82fa0..a4bb239eb987 100644
--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -49,7 +49,8 @@ static struct dentry *stat_dir;
* but it will at least advance closer to the next one
* to be released.
*/
-static struct rb_node *release_next(struct rb_node *node)
+static struct rb_node *release_next(struct tracer_stat *ts,
+ struct rb_node *node)
{
struct stat_node *snode;
struct rb_node *parent = rb_parent(node);
@@ -67,6 +68,8 @@ static struct rb_node *release_next(struct rb_node *node)
parent->rb_right = NULL;
snode = container_of(node, struct stat_node, node);
+ if (ts->stat_release)
+ ts->stat_release(snode->stat);
kfree(snode);
return parent;
@@ -78,7 +81,7 @@ static void __reset_stat_session(struct stat_session *session)
struct rb_node *node = session->stat_root.rb_node;
while (node)
- node = release_next(node);
+ node = release_next(session->ts, node);
session->stat_root = RB_ROOT;
}
@@ -200,17 +203,21 @@ static void *stat_seq_start(struct seq_file *s, loff_t *pos)
{
struct stat_session *session = s->private;
struct rb_node *node;
+ int n = *pos;
int i;
/* Prevent from tracer switch or rbtree modification */
mutex_lock(&session->stat_mutex);
/* If we are in the beginning of the file, print the headers */
- if (!*pos && session->ts->stat_headers)
- return SEQ_START_TOKEN;
+ if (session->ts->stat_headers) {
+ if (n == 0)
+ return SEQ_START_TOKEN;
+ n--;
+ }
node = rb_first(&session->stat_root);
- for (i = 0; node && i < *pos; i++)
+ for (i = 0; node && i < n; i++)
node = rb_next(node);
return node;
diff --git a/kernel/trace/trace_stat.h b/kernel/trace/trace_stat.h
index f3546a2cd826..8f03914b9a6a 100644
--- a/kernel/trace/trace_stat.h
+++ b/kernel/trace/trace_stat.h
@@ -18,6 +18,8 @@ struct tracer_stat {
int (*stat_cmp)(void *p1, void *p2);
/* Print a stat entry */
int (*stat_show)(struct seq_file *s, void *p);
+ /* Release an entry */
+ void (*stat_release)(void *stat);
/* Print the headers of your stat entries */
int (*stat_headers)(struct seq_file *s);
};
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 5e579645ac86..8712ce3c6a0e 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -1,30 +1,18 @@
#include <trace/syscall.h>
+#include <trace/events/syscalls.h>
#include <linux/kernel.h>
+#include <linux/ftrace.h>
+#include <linux/perf_counter.h>
#include <asm/syscall.h>
#include "trace_output.h"
#include "trace.h"
-/* Keep a counter of the syscall tracing users */
-static int refcount;
-
-/* Prevent from races on thread flags toggling */
static DEFINE_MUTEX(syscall_trace_lock);
-
-/* Option to display the parameters types */
-enum {
- TRACE_SYSCALLS_OPT_TYPES = 0x1,
-};
-
-static struct tracer_opt syscalls_opts[] = {
- { TRACER_OPT(syscall_arg_type, TRACE_SYSCALLS_OPT_TYPES) },
- { }
-};
-
-static struct tracer_flags syscalls_flags = {
- .val = 0, /* By default: no parameters types */
- .opts = syscalls_opts
-};
+static int sys_refcount_enter;
+static int sys_refcount_exit;
+static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
+static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);
enum print_line_t
print_syscall_enter(struct trace_iterator *iter, int flags)
@@ -35,35 +23,46 @@ print_syscall_enter(struct trace_iterator *iter, int flags)
struct syscall_metadata *entry;
int i, ret, syscall;
- trace_assign_type(trace, ent);
-
+ trace = (typeof(trace))ent;
syscall = trace->nr;
-
entry = syscall_nr_to_meta(syscall);
+
if (!entry)
goto end;
+ if (entry->enter_id != ent->type) {
+ WARN_ON_ONCE(1);
+ goto end;
+ }
+
ret = trace_seq_printf(s, "%s(", entry->name);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
for (i = 0; i < entry->nb_args; i++) {
/* parameter types */
- if (syscalls_flags.val & TRACE_SYSCALLS_OPT_TYPES) {
+ if (trace_flags & TRACE_ITER_VERBOSE) {
ret = trace_seq_printf(s, "%s ", entry->types[i]);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
/* parameter values */
- ret = trace_seq_printf(s, "%s: %lx%s ", entry->args[i],
+ ret = trace_seq_printf(s, "%s: %lx%s", entry->args[i],
trace->args[i],
- i == entry->nb_args - 1 ? ")" : ",");
+ i == entry->nb_args - 1 ? "" : ", ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
+ ret = trace_seq_putc(s, ')');
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
end:
- trace_seq_printf(s, "\n");
+ ret = trace_seq_putc(s, '\n');
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
return TRACE_TYPE_HANDLED;
}
@@ -77,16 +76,20 @@ print_syscall_exit(struct trace_iterator *iter, int flags)
struct syscall_metadata *entry;
int ret;
- trace_assign_type(trace, ent);
-
+ trace = (typeof(trace))ent;
syscall = trace->nr;
-
entry = syscall_nr_to_meta(syscall);
+
if (!entry) {
trace_seq_printf(s, "\n");
return TRACE_TYPE_HANDLED;
}
+ if (entry->exit_id != ent->type) {
+ WARN_ON_ONCE(1);
+ return TRACE_TYPE_UNHANDLED;
+ }
+
ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name,
trace->ret);
if (!ret)
@@ -95,62 +98,140 @@ print_syscall_exit(struct trace_iterator *iter, int flags)
return TRACE_TYPE_HANDLED;
}
-void start_ftrace_syscalls(void)
+extern char *__bad_type_size(void);
+
+#define SYSCALL_FIELD(type, name) \
+ sizeof(type) != sizeof(trace.name) ? \
+ __bad_type_size() : \
+ #type, #name, offsetof(typeof(trace), name), sizeof(trace.name)
+
+int syscall_enter_format(struct ftrace_event_call *call, struct trace_seq *s)
{
- unsigned long flags;
- struct task_struct *g, *t;
+ int i;
+ int nr;
+ int ret;
+ struct syscall_metadata *entry;
+ struct syscall_trace_enter trace;
+ int offset = offsetof(struct syscall_trace_enter, args);
- mutex_lock(&syscall_trace_lock);
+ nr = syscall_name_to_nr(call->data);
+ entry = syscall_nr_to_meta(nr);
- /* Don't enable the flag on the tasks twice */
- if (++refcount != 1)
- goto unlock;
+ if (!entry)
+ return 0;
- arch_init_ftrace_syscalls();
- read_lock_irqsave(&tasklist_lock, flags);
+ ret = trace_seq_printf(s, "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n",
+ SYSCALL_FIELD(int, nr));
+ if (!ret)
+ return 0;
- do_each_thread(g, t) {
- set_tsk_thread_flag(t, TIF_SYSCALL_FTRACE);
- } while_each_thread(g, t);
+ for (i = 0; i < entry->nb_args; i++) {
+ ret = trace_seq_printf(s, "\tfield:%s %s;", entry->types[i],
+ entry->args[i]);
+ if (!ret)
+ return 0;
+ ret = trace_seq_printf(s, "\toffset:%d;\tsize:%zu;\n", offset,
+ sizeof(unsigned long));
+ if (!ret)
+ return 0;
+ offset += sizeof(unsigned long);
+ }
- read_unlock_irqrestore(&tasklist_lock, flags);
+ trace_seq_puts(s, "\nprint fmt: \"");
+ for (i = 0; i < entry->nb_args; i++) {
+ ret = trace_seq_printf(s, "%s: 0x%%0%zulx%s", entry->args[i],
+ sizeof(unsigned long),
+ i == entry->nb_args - 1 ? "" : ", ");
+ if (!ret)
+ return 0;
+ }
+ trace_seq_putc(s, '"');
-unlock:
- mutex_unlock(&syscall_trace_lock);
+ for (i = 0; i < entry->nb_args; i++) {
+ ret = trace_seq_printf(s, ", ((unsigned long)(REC->%s))",
+ entry->args[i]);
+ if (!ret)
+ return 0;
+ }
+
+ return trace_seq_putc(s, '\n');
}
-void stop_ftrace_syscalls(void)
+int syscall_exit_format(struct ftrace_event_call *call, struct trace_seq *s)
{
- unsigned long flags;
- struct task_struct *g, *t;
+ int ret;
+ struct syscall_trace_exit trace;
- mutex_lock(&syscall_trace_lock);
+ ret = trace_seq_printf(s,
+ "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
+ "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n",
+ SYSCALL_FIELD(int, nr),
+ SYSCALL_FIELD(unsigned long, ret));
+ if (!ret)
+ return 0;
- /* There are perhaps still some users */
- if (--refcount)
- goto unlock;
+ return trace_seq_printf(s, "\nprint fmt: \"0x%%lx\", REC->ret\n");
+}
- read_lock_irqsave(&tasklist_lock, flags);
+int syscall_enter_define_fields(struct ftrace_event_call *call)
+{
+ struct syscall_trace_enter trace;
+ struct syscall_metadata *meta;
+ int ret;
+ int nr;
+ int i;
+ int offset = offsetof(typeof(trace), args);
+
+ nr = syscall_name_to_nr(call->data);
+ meta = syscall_nr_to_meta(nr);
+
+ if (!meta)
+ return 0;
+
+ ret = trace_define_common_fields(call);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < meta->nb_args; i++) {
+ ret = trace_define_field(call, meta->types[i],
+ meta->args[i], offset,
+ sizeof(unsigned long), 0,
+ FILTER_OTHER);
+ offset += sizeof(unsigned long);
+ }
- do_each_thread(g, t) {
- clear_tsk_thread_flag(t, TIF_SYSCALL_FTRACE);
- } while_each_thread(g, t);
+ return ret;
+}
- read_unlock_irqrestore(&tasklist_lock, flags);
+int syscall_exit_define_fields(struct ftrace_event_call *call)
+{
+ struct syscall_trace_exit trace;
+ int ret;
-unlock:
- mutex_unlock(&syscall_trace_lock);
+ ret = trace_define_common_fields(call);
+ if (ret)
+ return ret;
+
+ ret = trace_define_field(call, SYSCALL_FIELD(unsigned long, ret), 0,
+ FILTER_OTHER);
+
+ return ret;
}
-void ftrace_syscall_enter(struct pt_regs *regs)
+void ftrace_syscall_enter(struct pt_regs *regs, long id)
{
struct syscall_trace_enter *entry;
struct syscall_metadata *sys_data;
struct ring_buffer_event *event;
+ struct ring_buffer *buffer;
int size;
int syscall_nr;
syscall_nr = syscall_get_nr(current, regs);
+ if (syscall_nr < 0)
+ return;
+ if (!test_bit(syscall_nr, enabled_enter_syscalls))
+ return;
sys_data = syscall_nr_to_meta(syscall_nr);
if (!sys_data)
@@ -158,8 +239,8 @@ void ftrace_syscall_enter(struct pt_regs *regs)
size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
- event = trace_current_buffer_lock_reserve(TRACE_SYSCALL_ENTER, size,
- 0, 0);
+ event = trace_current_buffer_lock_reserve(&buffer, sys_data->enter_id,
+ size, 0, 0);
if (!event)
return;
@@ -167,24 +248,30 @@ void ftrace_syscall_enter(struct pt_regs *regs)
entry->nr = syscall_nr;
syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
- trace_current_buffer_unlock_commit(event, 0, 0);
- trace_wake_up();
+ if (!filter_current_check_discard(buffer, sys_data->enter_event,
+ entry, event))
+ trace_current_buffer_unlock_commit(buffer, event, 0, 0);
}
-void ftrace_syscall_exit(struct pt_regs *regs)
+void ftrace_syscall_exit(struct pt_regs *regs, long ret)
{
struct syscall_trace_exit *entry;
struct syscall_metadata *sys_data;
struct ring_buffer_event *event;
+ struct ring_buffer *buffer;
int syscall_nr;
syscall_nr = syscall_get_nr(current, regs);
+ if (syscall_nr < 0)
+ return;
+ if (!test_bit(syscall_nr, enabled_exit_syscalls))
+ return;
sys_data = syscall_nr_to_meta(syscall_nr);
if (!sys_data)
return;
- event = trace_current_buffer_lock_reserve(TRACE_SYSCALL_EXIT,
+ event = trace_current_buffer_lock_reserve(&buffer, sys_data->exit_id,
sizeof(*entry), 0, 0);
if (!event)
return;
@@ -193,58 +280,244 @@ void ftrace_syscall_exit(struct pt_regs *regs)
entry->nr = syscall_nr;
entry->ret = syscall_get_return_value(current, regs);
- trace_current_buffer_unlock_commit(event, 0, 0);
- trace_wake_up();
+ if (!filter_current_check_discard(buffer, sys_data->exit_event,
+ entry, event))
+ trace_current_buffer_unlock_commit(buffer, event, 0, 0);
}
-static int init_syscall_tracer(struct trace_array *tr)
+int reg_event_syscall_enter(void *ptr)
{
- start_ftrace_syscalls();
+ int ret = 0;
+ int num;
+ char *name;
+
+ name = (char *)ptr;
+ num = syscall_name_to_nr(name);
+ if (num < 0 || num >= NR_syscalls)
+ return -ENOSYS;
+ mutex_lock(&syscall_trace_lock);
+ if (!sys_refcount_enter)
+ ret = register_trace_sys_enter(ftrace_syscall_enter);
+ if (ret) {
+ pr_info("event trace: Could not activate"
+ "syscall entry trace point");
+ } else {
+ set_bit(num, enabled_enter_syscalls);
+ sys_refcount_enter++;
+ }
+ mutex_unlock(&syscall_trace_lock);
+ return ret;
+}
+
+void unreg_event_syscall_enter(void *ptr)
+{
+ int num;
+ char *name;
- return 0;
+ name = (char *)ptr;
+ num = syscall_name_to_nr(name);
+ if (num < 0 || num >= NR_syscalls)
+ return;
+ mutex_lock(&syscall_trace_lock);
+ sys_refcount_enter--;
+ clear_bit(num, enabled_enter_syscalls);
+ if (!sys_refcount_enter)
+ unregister_trace_sys_enter(ftrace_syscall_enter);
+ mutex_unlock(&syscall_trace_lock);
}
-static void reset_syscall_tracer(struct trace_array *tr)
+int reg_event_syscall_exit(void *ptr)
{
- stop_ftrace_syscalls();
- tracing_reset_online_cpus(tr);
+ int ret = 0;
+ int num;
+ char *name;
+
+ name = (char *)ptr;
+ num = syscall_name_to_nr(name);
+ if (num < 0 || num >= NR_syscalls)
+ return -ENOSYS;
+ mutex_lock(&syscall_trace_lock);
+ if (!sys_refcount_exit)
+ ret = register_trace_sys_exit(ftrace_syscall_exit);
+ if (ret) {
+ pr_info("event trace: Could not activate"
+ "syscall exit trace point");
+ } else {
+ set_bit(num, enabled_exit_syscalls);
+ sys_refcount_exit++;
+ }
+ mutex_unlock(&syscall_trace_lock);
+ return ret;
}
-static struct trace_event syscall_enter_event = {
- .type = TRACE_SYSCALL_ENTER,
- .trace = print_syscall_enter,
-};
+void unreg_event_syscall_exit(void *ptr)
+{
+ int num;
+ char *name;
+
+ name = (char *)ptr;
+ num = syscall_name_to_nr(name);
+ if (num < 0 || num >= NR_syscalls)
+ return;
+ mutex_lock(&syscall_trace_lock);
+ sys_refcount_exit--;
+ clear_bit(num, enabled_exit_syscalls);
+ if (!sys_refcount_exit)
+ unregister_trace_sys_exit(ftrace_syscall_exit);
+ mutex_unlock(&syscall_trace_lock);
+}
-static struct trace_event syscall_exit_event = {
- .type = TRACE_SYSCALL_EXIT,
- .trace = print_syscall_exit,
+struct trace_event event_syscall_enter = {
+ .trace = print_syscall_enter,
};
-static struct tracer syscall_tracer __read_mostly = {
- .name = "syscall",
- .init = init_syscall_tracer,
- .reset = reset_syscall_tracer,
- .flags = &syscalls_flags,
+struct trace_event event_syscall_exit = {
+ .trace = print_syscall_exit,
};
-__init int register_ftrace_syscalls(void)
+#ifdef CONFIG_EVENT_PROFILE
+
+static DECLARE_BITMAP(enabled_prof_enter_syscalls, NR_syscalls);
+static DECLARE_BITMAP(enabled_prof_exit_syscalls, NR_syscalls);
+static int sys_prof_refcount_enter;
+static int sys_prof_refcount_exit;
+
+static void prof_syscall_enter(struct pt_regs *regs, long id)
{
- int ret;
+ struct syscall_trace_enter *rec;
+ struct syscall_metadata *sys_data;
+ int syscall_nr;
+ int size;
- ret = register_ftrace_event(&syscall_enter_event);
- if (!ret) {
- printk(KERN_WARNING "event %d failed to register\n",
- syscall_enter_event.type);
- WARN_ON_ONCE(1);
+ syscall_nr = syscall_get_nr(current, regs);
+ if (!test_bit(syscall_nr, enabled_prof_enter_syscalls))
+ return;
+
+ sys_data = syscall_nr_to_meta(syscall_nr);
+ if (!sys_data)
+ return;
+
+ /* get the size after alignment with the u32 buffer size field */
+ size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec);
+ size = ALIGN(size + sizeof(u32), sizeof(u64));
+ size -= sizeof(u32);
+
+ do {
+ char raw_data[size];
+
+ /* zero the dead bytes from align to not leak stack to user */
+ *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+
+ rec = (struct syscall_trace_enter *) raw_data;
+ tracing_generic_entry_update(&rec->ent, 0, 0);
+ rec->ent.type = sys_data->enter_id;
+ rec->nr = syscall_nr;
+ syscall_get_arguments(current, regs, 0, sys_data->nb_args,
+ (unsigned long *)&rec->args);
+ perf_tpcounter_event(sys_data->enter_id, 0, 1, rec, size);
+ } while(0);
+}
+
+int reg_prof_syscall_enter(char *name)
+{
+ int ret = 0;
+ int num;
+
+ num = syscall_name_to_nr(name);
+ if (num < 0 || num >= NR_syscalls)
+ return -ENOSYS;
+
+ mutex_lock(&syscall_trace_lock);
+ if (!sys_prof_refcount_enter)
+ ret = register_trace_sys_enter(prof_syscall_enter);
+ if (ret) {
+ pr_info("event trace: Could not activate"
+ "syscall entry trace point");
+ } else {
+ set_bit(num, enabled_prof_enter_syscalls);
+ sys_prof_refcount_enter++;
}
+ mutex_unlock(&syscall_trace_lock);
+ return ret;
+}
- ret = register_ftrace_event(&syscall_exit_event);
- if (!ret) {
- printk(KERN_WARNING "event %d failed to register\n",
- syscall_exit_event.type);
- WARN_ON_ONCE(1);
+void unreg_prof_syscall_enter(char *name)
+{
+ int num;
+
+ num = syscall_name_to_nr(name);
+ if (num < 0 || num >= NR_syscalls)
+ return;
+
+ mutex_lock(&syscall_trace_lock);
+ sys_prof_refcount_enter--;
+ clear_bit(num, enabled_prof_enter_syscalls);
+ if (!sys_prof_refcount_enter)
+ unregister_trace_sys_enter(prof_syscall_enter);
+ mutex_unlock(&syscall_trace_lock);
+}
+
+static void prof_syscall_exit(struct pt_regs *regs, long ret)
+{
+ struct syscall_metadata *sys_data;
+ struct syscall_trace_exit rec;
+ int syscall_nr;
+
+ syscall_nr = syscall_get_nr(current, regs);
+ if (!test_bit(syscall_nr, enabled_prof_exit_syscalls))
+ return;
+
+ sys_data = syscall_nr_to_meta(syscall_nr);
+ if (!sys_data)
+ return;
+
+ tracing_generic_entry_update(&rec.ent, 0, 0);
+ rec.ent.type = sys_data->exit_id;
+ rec.nr = syscall_nr;
+ rec.ret = syscall_get_return_value(current, regs);
+
+ perf_tpcounter_event(sys_data->exit_id, 0, 1, &rec, sizeof(rec));
+}
+
+int reg_prof_syscall_exit(char *name)
+{
+ int ret = 0;
+ int num;
+
+ num = syscall_name_to_nr(name);
+ if (num < 0 || num >= NR_syscalls)
+ return -ENOSYS;
+
+ mutex_lock(&syscall_trace_lock);
+ if (!sys_prof_refcount_exit)
+ ret = register_trace_sys_exit(prof_syscall_exit);
+ if (ret) {
+ pr_info("event trace: Could not activate"
+ "syscall entry trace point");
+ } else {
+ set_bit(num, enabled_prof_exit_syscalls);
+ sys_prof_refcount_exit++;
}
+ mutex_unlock(&syscall_trace_lock);
+ return ret;
+}
- return register_tracer(&syscall_tracer);
+void unreg_prof_syscall_exit(char *name)
+{
+ int num;
+
+ num = syscall_name_to_nr(name);
+ if (num < 0 || num >= NR_syscalls)
+ return;
+
+ mutex_lock(&syscall_trace_lock);
+ sys_prof_refcount_exit--;
+ clear_bit(num, enabled_prof_exit_syscalls);
+ if (!sys_prof_refcount_exit)
+ unregister_trace_sys_exit(prof_syscall_exit);
+ mutex_unlock(&syscall_trace_lock);
}
-device_initcall(register_ftrace_syscalls);
+
+#endif
+
+
diff --git a/kernel/trace/trace_workqueue.c b/kernel/trace/trace_workqueue.c
index 97fcea4acce1..40cafb07dffd 100644
--- a/kernel/trace/trace_workqueue.c
+++ b/kernel/trace/trace_workqueue.c
@@ -9,6 +9,7 @@
#include <trace/events/workqueue.h>
#include <linux/list.h>
#include <linux/percpu.h>
+#include <linux/kref.h>
#include "trace_stat.h"
#include "trace.h"
@@ -16,6 +17,7 @@
/* A cpu workqueue thread */
struct cpu_workqueue_stats {
struct list_head list;
+ struct kref kref;
int cpu;
pid_t pid;
/* Can be inserted from interrupt or user context, need to be atomic */
@@ -39,6 +41,11 @@ struct workqueue_global_stats {
static DEFINE_PER_CPU(struct workqueue_global_stats, all_workqueue_stat);
#define workqueue_cpu_stat(cpu) (&per_cpu(all_workqueue_stat, cpu))
+static void cpu_workqueue_stat_free(struct kref *kref)
+{
+ kfree(container_of(kref, struct cpu_workqueue_stats, kref));
+}
+
/* Insertion of a work */
static void
probe_workqueue_insertion(struct task_struct *wq_thread,
@@ -96,8 +103,8 @@ static void probe_workqueue_creation(struct task_struct *wq_thread, int cpu)
return;
}
INIT_LIST_HEAD(&cws->list);
+ kref_init(&cws->kref);
cws->cpu = cpu;
-
cws->pid = wq_thread->pid;
spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
@@ -118,7 +125,7 @@ static void probe_workqueue_destruction(struct task_struct *wq_thread)
list) {
if (node->pid == wq_thread->pid) {
list_del(&node->list);
- kfree(node);
+ kref_put(&node->kref, cpu_workqueue_stat_free);
goto found;
}
}
@@ -137,9 +144,11 @@ static struct cpu_workqueue_stats *workqueue_stat_start_cpu(int cpu)
spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
- if (!list_empty(&workqueue_cpu_stat(cpu)->list))
+ if (!list_empty(&workqueue_cpu_stat(cpu)->list)) {
ret = list_entry(workqueue_cpu_stat(cpu)->list.next,
struct cpu_workqueue_stats, list);
+ kref_get(&ret->kref);
+ }
spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
@@ -162,9 +171,9 @@ static void *workqueue_stat_start(struct tracer_stat *trace)
static void *workqueue_stat_next(void *prev, int idx)
{
struct cpu_workqueue_stats *prev_cws = prev;
+ struct cpu_workqueue_stats *ret;
int cpu = prev_cws->cpu;
unsigned long flags;
- void *ret = NULL;
spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
if (list_is_last(&prev_cws->list, &workqueue_cpu_stat(cpu)->list)) {
@@ -175,11 +184,14 @@ static void *workqueue_stat_next(void *prev, int idx)
return NULL;
} while (!(ret = workqueue_stat_start_cpu(cpu)));
return ret;
+ } else {
+ ret = list_entry(prev_cws->list.next,
+ struct cpu_workqueue_stats, list);
+ kref_get(&ret->kref);
}
spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
- return list_entry(prev_cws->list.next, struct cpu_workqueue_stats,
- list);
+ return ret;
}
static int workqueue_stat_show(struct seq_file *s, void *p)
@@ -203,6 +215,13 @@ static int workqueue_stat_show(struct seq_file *s, void *p)
return 0;
}
+static void workqueue_stat_release(void *stat)
+{
+ struct cpu_workqueue_stats *node = stat;
+
+ kref_put(&node->kref, cpu_workqueue_stat_free);
+}
+
static int workqueue_stat_headers(struct seq_file *s)
{
seq_printf(s, "# CPU INSERTED EXECUTED NAME\n");
@@ -215,6 +234,7 @@ struct tracer_stat workqueue_stats __read_mostly = {
.stat_start = workqueue_stat_start,
.stat_next = workqueue_stat_next,
.stat_show = workqueue_stat_show,
+ .stat_release = workqueue_stat_release,
.stat_headers = workqueue_stat_headers
};
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 1ef5d3a601c7..9489a0a9b1be 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -24,6 +24,7 @@
#include <linux/tracepoint.h>
#include <linux/err.h>
#include <linux/slab.h>
+#include <linux/sched.h>
extern struct tracepoint __start___tracepoints[];
extern struct tracepoint __stop___tracepoints[];
@@ -242,6 +243,11 @@ static void set_tracepoint(struct tracepoint_entry **entry,
{
WARN_ON(strcmp((*entry)->name, elem->name) != 0);
+ if (elem->regfunc && !elem->state && active)
+ elem->regfunc();
+ else if (elem->unregfunc && elem->state && !active)
+ elem->unregfunc();
+
/*
* rcu_assign_pointer has a smp_wmb() which makes sure that the new
* probe callbacks array is consistent before setting a pointer to it.
@@ -261,6 +267,9 @@ static void set_tracepoint(struct tracepoint_entry **entry,
*/
static void disable_tracepoint(struct tracepoint *elem)
{
+ if (elem->unregfunc && elem->state)
+ elem->unregfunc();
+
elem->state = 0;
rcu_assign_pointer(elem->funcs, NULL);
}
@@ -554,9 +563,6 @@ int tracepoint_module_notify(struct notifier_block *self,
switch (val) {
case MODULE_STATE_COMING:
- tracepoint_update_probe_range(mod->tracepoints,
- mod->tracepoints + mod->num_tracepoints);
- break;
case MODULE_STATE_GOING:
tracepoint_update_probe_range(mod->tracepoints,
mod->tracepoints + mod->num_tracepoints);
@@ -577,3 +583,41 @@ static int init_tracepoints(void)
__initcall(init_tracepoints);
#endif /* CONFIG_MODULES */
+
+#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
+
+/* NB: reg/unreg are called while guarded with the tracepoints_mutex */
+static int sys_tracepoint_refcount;
+
+void syscall_regfunc(void)
+{
+ unsigned long flags;
+ struct task_struct *g, *t;
+
+ if (!sys_tracepoint_refcount) {
+ read_lock_irqsave(&tasklist_lock, flags);
+ do_each_thread(g, t) {
+ /* Skip kernel threads. */
+ if (t->mm)
+ set_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT);
+ } while_each_thread(g, t);
+ read_unlock_irqrestore(&tasklist_lock, flags);
+ }
+ sys_tracepoint_refcount++;
+}
+
+void syscall_unregfunc(void)
+{
+ unsigned long flags;
+ struct task_struct *g, *t;
+
+ sys_tracepoint_refcount--;
+ if (!sys_tracepoint_refcount) {
+ read_lock_irqsave(&tasklist_lock, flags);
+ do_each_thread(g, t) {
+ clear_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT);
+ } while_each_thread(g, t);
+ read_unlock_irqrestore(&tasklist_lock, flags);
+ }
+}
+#endif
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 0668795d8818..addfe2df93b1 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -317,8 +317,6 @@ static int worker_thread(void *__cwq)
if (cwq->wq->freezeable)
set_freezable();
- set_user_nice(current, -5);
-
for (;;) {
prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE);
if (!freezing(current) &&
@@ -600,7 +598,12 @@ static struct workqueue_struct *keventd_wq __read_mostly;
* schedule_work - put work task in global workqueue
* @work: job to be done
*
- * This puts a job in the kernel-global workqueue.
+ * Returns zero if @work was already on the kernel-global workqueue and
+ * non-zero otherwise.
+ *
+ * This puts a job in the kernel-global workqueue if it was not already
+ * queued and leaves it in the same position on the kernel-global
+ * workqueue otherwise.
*/
int schedule_work(struct work_struct *work)
{