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-rw-r--r--kernel/cpuset.c262
1 files changed, 97 insertions, 165 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index e6b1b66afe52..e2dbb60004d4 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -119,7 +119,7 @@ static inline struct cpuset *css_cs(struct cgroup_subsys_state *css)
/* Retrieve the cpuset for a task */
static inline struct cpuset *task_cs(struct task_struct *task)
{
- return css_cs(task_css(task, cpuset_subsys_id));
+ return css_cs(task_css(task, cpuset_cgrp_id));
}
static inline struct cpuset *parent_cs(struct cpuset *cs)
@@ -467,7 +467,7 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
* be changed to have empty cpus_allowed or mems_allowed.
*/
ret = -ENOSPC;
- if ((cgroup_task_count(cur->css.cgroup) || cur->attach_in_progress)) {
+ if ((cgroup_has_tasks(cur->css.cgroup) || cur->attach_in_progress)) {
if (!cpumask_empty(cur->cpus_allowed) &&
cpumask_empty(trial->cpus_allowed))
goto out;
@@ -829,55 +829,36 @@ static struct cpuset *effective_nodemask_cpuset(struct cpuset *cs)
}
/**
- * cpuset_change_cpumask - make a task's cpus_allowed the same as its cpuset's
- * @tsk: task to test
- * @data: cpuset to @tsk belongs to
- *
- * Called by css_scan_tasks() for each task in a cgroup whose cpus_allowed
- * mask needs to be changed.
- *
- * We don't need to re-check for the cgroup/cpuset membership, since we're
- * holding cpuset_mutex at this point.
- */
-static void cpuset_change_cpumask(struct task_struct *tsk, void *data)
-{
- struct cpuset *cs = data;
- struct cpuset *cpus_cs = effective_cpumask_cpuset(cs);
-
- set_cpus_allowed_ptr(tsk, cpus_cs->cpus_allowed);
-}
-
-/**
* update_tasks_cpumask - Update the cpumasks of tasks in the cpuset.
* @cs: the cpuset in which each task's cpus_allowed mask needs to be changed
- * @heap: if NULL, defer allocating heap memory to css_scan_tasks()
- *
- * Called with cpuset_mutex held
*
- * The css_scan_tasks() function will scan all the tasks in a cgroup,
- * calling callback functions for each.
- *
- * No return value. It's guaranteed that css_scan_tasks() always returns 0
- * if @heap != NULL.
+ * Iterate through each task of @cs updating its cpus_allowed to the
+ * effective cpuset's. As this function is called with cpuset_mutex held,
+ * cpuset membership stays stable.
*/
-static void update_tasks_cpumask(struct cpuset *cs, struct ptr_heap *heap)
+static void update_tasks_cpumask(struct cpuset *cs)
{
- css_scan_tasks(&cs->css, NULL, cpuset_change_cpumask, cs, heap);
+ struct cpuset *cpus_cs = effective_cpumask_cpuset(cs);
+ struct css_task_iter it;
+ struct task_struct *task;
+
+ css_task_iter_start(&cs->css, &it);
+ while ((task = css_task_iter_next(&it)))
+ set_cpus_allowed_ptr(task, cpus_cs->cpus_allowed);
+ css_task_iter_end(&it);
}
/*
* update_tasks_cpumask_hier - Update the cpumasks of tasks in the hierarchy.
* @root_cs: the root cpuset of the hierarchy
* @update_root: update root cpuset or not?
- * @heap: the heap used by css_scan_tasks()
*
* This will update cpumasks of tasks in @root_cs and all other empty cpusets
* which take on cpumask of @root_cs.
*
* Called with cpuset_mutex held
*/
-static void update_tasks_cpumask_hier(struct cpuset *root_cs,
- bool update_root, struct ptr_heap *heap)
+static void update_tasks_cpumask_hier(struct cpuset *root_cs, bool update_root)
{
struct cpuset *cp;
struct cgroup_subsys_state *pos_css;
@@ -898,7 +879,7 @@ static void update_tasks_cpumask_hier(struct cpuset *root_cs,
continue;
rcu_read_unlock();
- update_tasks_cpumask(cp, heap);
+ update_tasks_cpumask(cp);
rcu_read_lock();
css_put(&cp->css);
@@ -914,7 +895,6 @@ static void update_tasks_cpumask_hier(struct cpuset *root_cs,
static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
const char *buf)
{
- struct ptr_heap heap;
int retval;
int is_load_balanced;
@@ -947,19 +927,13 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
if (retval < 0)
return retval;
- retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
- if (retval)
- return retval;
-
is_load_balanced = is_sched_load_balance(trialcs);
mutex_lock(&callback_mutex);
cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed);
mutex_unlock(&callback_mutex);
- update_tasks_cpumask_hier(cs, true, &heap);
-
- heap_free(&heap);
+ update_tasks_cpumask_hier(cs, true);
if (is_load_balanced)
rebuild_sched_domains_locked();
@@ -1048,53 +1022,22 @@ static void cpuset_change_task_nodemask(struct task_struct *tsk,
task_unlock(tsk);
}
-struct cpuset_change_nodemask_arg {
- struct cpuset *cs;
- nodemask_t *newmems;
-};
-
-/*
- * Update task's mems_allowed and rebind its mempolicy and vmas' mempolicy
- * of it to cpuset's new mems_allowed, and migrate pages to new nodes if
- * memory_migrate flag is set. Called with cpuset_mutex held.
- */
-static void cpuset_change_nodemask(struct task_struct *p, void *data)
-{
- struct cpuset_change_nodemask_arg *arg = data;
- struct cpuset *cs = arg->cs;
- struct mm_struct *mm;
- int migrate;
-
- cpuset_change_task_nodemask(p, arg->newmems);
-
- mm = get_task_mm(p);
- if (!mm)
- return;
-
- migrate = is_memory_migrate(cs);
-
- mpol_rebind_mm(mm, &cs->mems_allowed);
- if (migrate)
- cpuset_migrate_mm(mm, &cs->old_mems_allowed, arg->newmems);
- mmput(mm);
-}
-
static void *cpuset_being_rebound;
/**
* update_tasks_nodemask - Update the nodemasks of tasks in the cpuset.
* @cs: the cpuset in which each task's mems_allowed mask needs to be changed
- * @heap: if NULL, defer allocating heap memory to css_scan_tasks()
*
- * Called with cpuset_mutex held. No return value. It's guaranteed that
- * css_scan_tasks() always returns 0 if @heap != NULL.
+ * Iterate through each task of @cs updating its mems_allowed to the
+ * effective cpuset's. As this function is called with cpuset_mutex held,
+ * cpuset membership stays stable.
*/
-static void update_tasks_nodemask(struct cpuset *cs, struct ptr_heap *heap)
+static void update_tasks_nodemask(struct cpuset *cs)
{
static nodemask_t newmems; /* protected by cpuset_mutex */
struct cpuset *mems_cs = effective_nodemask_cpuset(cs);
- struct cpuset_change_nodemask_arg arg = { .cs = cs,
- .newmems = &newmems };
+ struct css_task_iter it;
+ struct task_struct *task;
cpuset_being_rebound = cs; /* causes mpol_dup() rebind */
@@ -1110,7 +1053,25 @@ static void update_tasks_nodemask(struct cpuset *cs, struct ptr_heap *heap)
* It's ok if we rebind the same mm twice; mpol_rebind_mm()
* is idempotent. Also migrate pages in each mm to new nodes.
*/
- css_scan_tasks(&cs->css, NULL, cpuset_change_nodemask, &arg, heap);
+ css_task_iter_start(&cs->css, &it);
+ while ((task = css_task_iter_next(&it))) {
+ struct mm_struct *mm;
+ bool migrate;
+
+ cpuset_change_task_nodemask(task, &newmems);
+
+ mm = get_task_mm(task);
+ if (!mm)
+ continue;
+
+ migrate = is_memory_migrate(cs);
+
+ mpol_rebind_mm(mm, &cs->mems_allowed);
+ if (migrate)
+ cpuset_migrate_mm(mm, &cs->old_mems_allowed, &newmems);
+ mmput(mm);
+ }
+ css_task_iter_end(&it);
/*
* All the tasks' nodemasks have been updated, update
@@ -1126,15 +1087,13 @@ static void update_tasks_nodemask(struct cpuset *cs, struct ptr_heap *heap)
* update_tasks_nodemask_hier - Update the nodemasks of tasks in the hierarchy.
* @cs: the root cpuset of the hierarchy
* @update_root: update the root cpuset or not?
- * @heap: the heap used by css_scan_tasks()
*
* This will update nodemasks of tasks in @root_cs and all other empty cpusets
* which take on nodemask of @root_cs.
*
* Called with cpuset_mutex held
*/
-static void update_tasks_nodemask_hier(struct cpuset *root_cs,
- bool update_root, struct ptr_heap *heap)
+static void update_tasks_nodemask_hier(struct cpuset *root_cs, bool update_root)
{
struct cpuset *cp;
struct cgroup_subsys_state *pos_css;
@@ -1155,7 +1114,7 @@ static void update_tasks_nodemask_hier(struct cpuset *root_cs,
continue;
rcu_read_unlock();
- update_tasks_nodemask(cp, heap);
+ update_tasks_nodemask(cp);
rcu_read_lock();
css_put(&cp->css);
@@ -1180,7 +1139,6 @@ static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs,
const char *buf)
{
int retval;
- struct ptr_heap heap;
/*
* top_cpuset.mems_allowed tracks node_stats[N_MEMORY];
@@ -1219,17 +1177,11 @@ static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs,
if (retval < 0)
goto done;
- retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
- if (retval < 0)
- goto done;
-
mutex_lock(&callback_mutex);
cs->mems_allowed = trialcs->mems_allowed;
mutex_unlock(&callback_mutex);
- update_tasks_nodemask_hier(cs, true, &heap);
-
- heap_free(&heap);
+ update_tasks_nodemask_hier(cs, true);
done:
return retval;
}
@@ -1257,38 +1209,22 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val)
}
/**
- * cpuset_change_flag - make a task's spread flags the same as its cpuset's
- * @tsk: task to be updated
- * @data: cpuset to @tsk belongs to
- *
- * Called by css_scan_tasks() for each task in a cgroup.
- *
- * We don't need to re-check for the cgroup/cpuset membership, since we're
- * holding cpuset_mutex at this point.
- */
-static void cpuset_change_flag(struct task_struct *tsk, void *data)
-{
- struct cpuset *cs = data;
-
- cpuset_update_task_spread_flag(cs, tsk);
-}
-
-/**
* update_tasks_flags - update the spread flags of tasks in the cpuset.
* @cs: the cpuset in which each task's spread flags needs to be changed
- * @heap: if NULL, defer allocating heap memory to css_scan_tasks()
- *
- * Called with cpuset_mutex held
*
- * The css_scan_tasks() function will scan all the tasks in a cgroup,
- * calling callback functions for each.
- *
- * No return value. It's guaranteed that css_scan_tasks() always returns 0
- * if @heap != NULL.
+ * Iterate through each task of @cs updating its spread flags. As this
+ * function is called with cpuset_mutex held, cpuset membership stays
+ * stable.
*/
-static void update_tasks_flags(struct cpuset *cs, struct ptr_heap *heap)
+static void update_tasks_flags(struct cpuset *cs)
{
- css_scan_tasks(&cs->css, NULL, cpuset_change_flag, cs, heap);
+ struct css_task_iter it;
+ struct task_struct *task;
+
+ css_task_iter_start(&cs->css, &it);
+ while ((task = css_task_iter_next(&it)))
+ cpuset_update_task_spread_flag(cs, task);
+ css_task_iter_end(&it);
}
/*
@@ -1306,7 +1242,6 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
struct cpuset *trialcs;
int balance_flag_changed;
int spread_flag_changed;
- struct ptr_heap heap;
int err;
trialcs = alloc_trial_cpuset(cs);
@@ -1322,10 +1257,6 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
if (err < 0)
goto out;
- err = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
- if (err < 0)
- goto out;
-
balance_flag_changed = (is_sched_load_balance(cs) !=
is_sched_load_balance(trialcs));
@@ -1340,8 +1271,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
rebuild_sched_domains_locked();
if (spread_flag_changed)
- update_tasks_flags(cs, &heap);
- heap_free(&heap);
+ update_tasks_flags(cs);
out:
free_trial_cpuset(trialcs);
return err;
@@ -1445,6 +1375,8 @@ static int fmeter_getrate(struct fmeter *fmp)
return val;
}
+static struct cpuset *cpuset_attach_old_cs;
+
/* Called by cgroups to determine if a cpuset is usable; cpuset_mutex held */
static int cpuset_can_attach(struct cgroup_subsys_state *css,
struct cgroup_taskset *tset)
@@ -1453,6 +1385,9 @@ static int cpuset_can_attach(struct cgroup_subsys_state *css,
struct task_struct *task;
int ret;
+ /* used later by cpuset_attach() */
+ cpuset_attach_old_cs = task_cs(cgroup_taskset_first(tset));
+
mutex_lock(&cpuset_mutex);
/*
@@ -1464,7 +1399,7 @@ static int cpuset_can_attach(struct cgroup_subsys_state *css,
(cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)))
goto out_unlock;
- cgroup_taskset_for_each(task, css, tset) {
+ cgroup_taskset_for_each(task, tset) {
/*
* Kthreads which disallow setaffinity shouldn't be moved
* to a new cpuset; we don't want to change their cpu
@@ -1516,10 +1451,8 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
struct mm_struct *mm;
struct task_struct *task;
struct task_struct *leader = cgroup_taskset_first(tset);
- struct cgroup_subsys_state *oldcss = cgroup_taskset_cur_css(tset,
- cpuset_subsys_id);
struct cpuset *cs = css_cs(css);
- struct cpuset *oldcs = css_cs(oldcss);
+ struct cpuset *oldcs = cpuset_attach_old_cs;
struct cpuset *cpus_cs = effective_cpumask_cpuset(cs);
struct cpuset *mems_cs = effective_nodemask_cpuset(cs);
@@ -1533,7 +1466,7 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
guarantee_online_mems(mems_cs, &cpuset_attach_nodemask_to);
- cgroup_taskset_for_each(task, css, tset) {
+ cgroup_taskset_for_each(task, tset) {
/*
* can_attach beforehand should guarantee that this doesn't
* fail. TODO: have a better way to handle failure here
@@ -1673,7 +1606,7 @@ out_unlock:
* Common handling for a write to a "cpus" or "mems" file.
*/
static int cpuset_write_resmask(struct cgroup_subsys_state *css,
- struct cftype *cft, const char *buf)
+ struct cftype *cft, char *buf)
{
struct cpuset *cs = css_cs(css);
struct cpuset *trialcs;
@@ -2020,8 +1953,7 @@ static void cpuset_css_free(struct cgroup_subsys_state *css)
kfree(cs);
}
-struct cgroup_subsys cpuset_subsys = {
- .name = "cpuset",
+struct cgroup_subsys cpuset_cgrp_subsys = {
.css_alloc = cpuset_css_alloc,
.css_online = cpuset_css_online,
.css_offline = cpuset_css_offline,
@@ -2029,7 +1961,6 @@ struct cgroup_subsys cpuset_subsys = {
.can_attach = cpuset_can_attach,
.cancel_attach = cpuset_cancel_attach,
.attach = cpuset_attach,
- .subsys_id = cpuset_subsys_id,
.base_cftypes = files,
.early_init = 1,
};
@@ -2086,10 +2017,9 @@ static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
parent = parent_cs(parent);
if (cgroup_transfer_tasks(parent->css.cgroup, cs->css.cgroup)) {
- rcu_read_lock();
- printk(KERN_ERR "cpuset: failed to transfer tasks out of empty cpuset %s\n",
- cgroup_name(cs->css.cgroup));
- rcu_read_unlock();
+ printk(KERN_ERR "cpuset: failed to transfer tasks out of empty cpuset ");
+ pr_cont_cgroup_name(cs->css.cgroup);
+ pr_cont("\n");
}
}
@@ -2137,7 +2067,7 @@ retry:
*/
if ((sane && cpumask_empty(cs->cpus_allowed)) ||
(!cpumask_empty(&off_cpus) && !cpumask_empty(cs->cpus_allowed)))
- update_tasks_cpumask(cs, NULL);
+ update_tasks_cpumask(cs);
mutex_lock(&callback_mutex);
nodes_andnot(cs->mems_allowed, cs->mems_allowed, off_mems);
@@ -2151,7 +2081,7 @@ retry:
*/
if ((sane && nodes_empty(cs->mems_allowed)) ||
(!nodes_empty(off_mems) && !nodes_empty(cs->mems_allowed)))
- update_tasks_nodemask(cs, NULL);
+ update_tasks_nodemask(cs);
is_empty = cpumask_empty(cs->cpus_allowed) ||
nodes_empty(cs->mems_allowed);
@@ -2213,7 +2143,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
mutex_lock(&callback_mutex);
top_cpuset.mems_allowed = new_mems;
mutex_unlock(&callback_mutex);
- update_tasks_nodemask(&top_cpuset, NULL);
+ update_tasks_nodemask(&top_cpuset);
}
mutex_unlock(&cpuset_mutex);
@@ -2305,10 +2235,10 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
struct cpuset *cpus_cs;
mutex_lock(&callback_mutex);
- task_lock(tsk);
+ rcu_read_lock();
cpus_cs = effective_cpumask_cpuset(task_cs(tsk));
guarantee_online_cpus(cpus_cs, pmask);
- task_unlock(tsk);
+ rcu_read_unlock();
mutex_unlock(&callback_mutex);
}
@@ -2361,10 +2291,10 @@ nodemask_t cpuset_mems_allowed(struct task_struct *tsk)
nodemask_t mask;
mutex_lock(&callback_mutex);
- task_lock(tsk);
+ rcu_read_lock();
mems_cs = effective_nodemask_cpuset(task_cs(tsk));
guarantee_online_mems(mems_cs, &mask);
- task_unlock(tsk);
+ rcu_read_unlock();
mutex_unlock(&callback_mutex);
return mask;
@@ -2480,10 +2410,10 @@ int __cpuset_node_allowed_softwall(int node, gfp_t gfp_mask)
/* Not hardwall and node outside mems_allowed: scan up cpusets */
mutex_lock(&callback_mutex);
- task_lock(current);
+ rcu_read_lock();
cs = nearest_hardwall_ancestor(task_cs(current));
allowed = node_isset(node, cs->mems_allowed);
- task_unlock(current);
+ rcu_read_unlock();
mutex_unlock(&callback_mutex);
return allowed;
@@ -2609,27 +2539,27 @@ int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
* @task: pointer to task_struct of some task.
*
* Description: Prints @task's name, cpuset name, and cached copy of its
- * mems_allowed to the kernel log. Must hold task_lock(task) to allow
- * dereferencing task_cs(task).
+ * mems_allowed to the kernel log.
*/
void cpuset_print_task_mems_allowed(struct task_struct *tsk)
{
/* Statically allocated to prevent using excess stack. */
static char cpuset_nodelist[CPUSET_NODELIST_LEN];
static DEFINE_SPINLOCK(cpuset_buffer_lock);
+ struct cgroup *cgrp;
- struct cgroup *cgrp = task_cs(tsk)->css.cgroup;
-
- rcu_read_lock();
spin_lock(&cpuset_buffer_lock);
+ rcu_read_lock();
+ cgrp = task_cs(tsk)->css.cgroup;
nodelist_scnprintf(cpuset_nodelist, CPUSET_NODELIST_LEN,
tsk->mems_allowed);
- printk(KERN_INFO "%s cpuset=%s mems_allowed=%s\n",
- tsk->comm, cgroup_name(cgrp), cpuset_nodelist);
+ printk(KERN_INFO "%s cpuset=", tsk->comm);
+ pr_cont_cgroup_name(cgrp);
+ pr_cont(" mems_allowed=%s\n", cpuset_nodelist);
- spin_unlock(&cpuset_buffer_lock);
rcu_read_unlock();
+ spin_unlock(&cpuset_buffer_lock);
}
/*
@@ -2660,9 +2590,9 @@ int cpuset_memory_pressure_enabled __read_mostly;
void __cpuset_memory_pressure_bump(void)
{
- task_lock(current);
+ rcu_read_lock();
fmeter_markevent(&task_cs(current)->fmeter);
- task_unlock(current);
+ rcu_read_unlock();
}
#ifdef CONFIG_PROC_PID_CPUSET
@@ -2679,12 +2609,12 @@ int proc_cpuset_show(struct seq_file *m, void *unused_v)
{
struct pid *pid;
struct task_struct *tsk;
- char *buf;
+ char *buf, *p;
struct cgroup_subsys_state *css;
int retval;
retval = -ENOMEM;
- buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ buf = kmalloc(PATH_MAX, GFP_KERNEL);
if (!buf)
goto out;
@@ -2694,14 +2624,16 @@ int proc_cpuset_show(struct seq_file *m, void *unused_v)
if (!tsk)
goto out_free;
+ retval = -ENAMETOOLONG;
rcu_read_lock();
- css = task_css(tsk, cpuset_subsys_id);
- retval = cgroup_path(css->cgroup, buf, PAGE_SIZE);
+ css = task_css(tsk, cpuset_cgrp_id);
+ p = cgroup_path(css->cgroup, buf, PATH_MAX);
rcu_read_unlock();
- if (retval < 0)
+ if (!p)
goto out_put_task;
- seq_puts(m, buf);
+ seq_puts(m, p);
seq_putc(m, '\n');
+ retval = 0;
out_put_task:
put_task_struct(tsk);
out_free: