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-rw-r--r--kernel/cgroup/cgroup.c13
-rw-r--r--kernel/power/suspend.c9
-rw-r--r--kernel/sched/core.c63
-rw-r--r--kernel/sched/fair.c56
-rw-r--r--kernel/sched/loadavg.c33
-rw-r--r--kernel/sched/psi.c3
-rw-r--r--kernel/sched/sched.h15
-rw-r--r--kernel/trace/trace_events_hist.c227
-rw-r--r--kernel/trace/trace_kprobe.c2
9 files changed, 217 insertions, 204 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index db552b9f9377..75f687301bbf 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -5927,11 +5927,14 @@ void cgroup_post_fork(struct task_struct *child)
spin_lock_irq(&css_set_lock);
- WARN_ON_ONCE(!list_empty(&child->cg_list));
- cset = task_css_set(current); /* current is @child's parent */
- get_css_set(cset);
- cset->nr_tasks++;
- css_set_move_task(child, NULL, cset, false);
+ /* init tasks are special, only link regular threads */
+ if (likely(child->pid)) {
+ WARN_ON_ONCE(!list_empty(&child->cg_list));
+ cset = task_css_set(current); /* current is @child's parent */
+ get_css_set(cset);
+ cset->nr_tasks++;
+ css_set_move_task(child, NULL, cset, false);
+ }
/*
* If the cgroup has to be frozen, the new task has too. Let's set
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 2c47280fbfc7..8b1bb5ee7e5d 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -131,11 +131,12 @@ static void s2idle_loop(void)
* to avoid them upfront.
*/
for (;;) {
- if (s2idle_ops && s2idle_ops->wake)
- s2idle_ops->wake();
-
- if (pm_wakeup_pending())
+ if (s2idle_ops && s2idle_ops->wake) {
+ if (s2idle_ops->wake())
+ break;
+ } else if (pm_wakeup_pending()) {
break;
+ }
pm_wakeup_clear(false);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index fc1dfc007604..1a9983da4408 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -552,27 +552,32 @@ void resched_cpu(int cpu)
*/
int get_nohz_timer_target(void)
{
- int i, cpu = smp_processor_id();
+ int i, cpu = smp_processor_id(), default_cpu = -1;
struct sched_domain *sd;
- if (!idle_cpu(cpu) && housekeeping_cpu(cpu, HK_FLAG_TIMER))
- return cpu;
+ if (housekeeping_cpu(cpu, HK_FLAG_TIMER)) {
+ if (!idle_cpu(cpu))
+ return cpu;
+ default_cpu = cpu;
+ }
rcu_read_lock();
for_each_domain(cpu, sd) {
- for_each_cpu(i, sched_domain_span(sd)) {
+ for_each_cpu_and(i, sched_domain_span(sd),
+ housekeeping_cpumask(HK_FLAG_TIMER)) {
if (cpu == i)
continue;
- if (!idle_cpu(i) && housekeeping_cpu(i, HK_FLAG_TIMER)) {
+ if (!idle_cpu(i)) {
cpu = i;
goto unlock;
}
}
}
- if (!housekeeping_cpu(cpu, HK_FLAG_TIMER))
- cpu = housekeeping_any_cpu(HK_FLAG_TIMER);
+ if (default_cpu == -1)
+ default_cpu = housekeeping_any_cpu(HK_FLAG_TIMER);
+ cpu = default_cpu;
unlock:
rcu_read_unlock();
return cpu;
@@ -1442,17 +1447,6 @@ void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
#ifdef CONFIG_SMP
-static inline bool is_per_cpu_kthread(struct task_struct *p)
-{
- if (!(p->flags & PF_KTHREAD))
- return false;
-
- if (p->nr_cpus_allowed != 1)
- return false;
-
- return true;
-}
-
/*
* Per-CPU kthreads are allowed to run on !active && online CPUs, see
* __set_cpus_allowed_ptr() and select_fallback_rq().
@@ -3669,28 +3663,32 @@ static void sched_tick_remote(struct work_struct *work)
* statistics and checks timeslices in a time-independent way, regardless
* of when exactly it is running.
*/
- if (idle_cpu(cpu) || !tick_nohz_tick_stopped_cpu(cpu))
+ if (!tick_nohz_tick_stopped_cpu(cpu))
goto out_requeue;
rq_lock_irq(rq, &rf);
curr = rq->curr;
- if (is_idle_task(curr) || cpu_is_offline(cpu))
+ if (cpu_is_offline(cpu))
goto out_unlock;
+ curr = rq->curr;
update_rq_clock(rq);
- delta = rq_clock_task(rq) - curr->se.exec_start;
- /*
- * Make sure the next tick runs within a reasonable
- * amount of time.
- */
- WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 3);
+ if (!is_idle_task(curr)) {
+ /*
+ * Make sure the next tick runs within a reasonable
+ * amount of time.
+ */
+ delta = rq_clock_task(rq) - curr->se.exec_start;
+ WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 3);
+ }
curr->sched_class->task_tick(rq, curr, 0);
+ calc_load_nohz_remote(rq);
out_unlock:
rq_unlock_irq(rq, &rf);
-
out_requeue:
+
/*
* Run the remote tick once per second (1Hz). This arbitrary
* frequency is large enough to avoid overload but short enough
@@ -7063,8 +7061,15 @@ void sched_move_task(struct task_struct *tsk)
if (queued)
enqueue_task(rq, tsk, queue_flags);
- if (running)
+ if (running) {
set_next_task(rq, tsk);
+ /*
+ * After changing group, the running task may have joined a
+ * throttled one but it's still the running task. Trigger a
+ * resched to make sure that task can still run.
+ */
+ resched_curr(rq);
+ }
task_rq_unlock(rq, tsk, &rf);
}
@@ -7260,7 +7265,7 @@ capacity_from_percent(char *buf)
&req.percent);
if (req.ret)
return req;
- if (req.percent > UCLAMP_PERCENT_SCALE) {
+ if ((u64)req.percent > UCLAMP_PERCENT_SCALE) {
req.ret = -ERANGE;
return req;
}
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index fe4e0d775375..3c8a379c357e 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3516,7 +3516,6 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
* attach_entity_load_avg - attach this entity to its cfs_rq load avg
* @cfs_rq: cfs_rq to attach to
* @se: sched_entity to attach
- * @flags: migration hints
*
* Must call update_cfs_rq_load_avg() before this, since we rely on
* cfs_rq->avg.last_update_time being current.
@@ -5912,6 +5911,20 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target)
(available_idle_cpu(prev) || sched_idle_cpu(prev)))
return prev;
+ /*
+ * Allow a per-cpu kthread to stack with the wakee if the
+ * kworker thread and the tasks previous CPUs are the same.
+ * The assumption is that the wakee queued work for the
+ * per-cpu kthread that is now complete and the wakeup is
+ * essentially a sync wakeup. An obvious example of this
+ * pattern is IO completions.
+ */
+ if (is_per_cpu_kthread(current) &&
+ prev == smp_processor_id() &&
+ this_rq()->nr_running <= 1) {
+ return prev;
+ }
+
/* Check a recently used CPU as a potential idle candidate: */
recent_used_cpu = p->recent_used_cpu;
if (recent_used_cpu != prev &&
@@ -8658,10 +8671,6 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
/*
* Try to use spare capacity of local group without overloading it or
* emptying busiest.
- * XXX Spreading tasks across NUMA nodes is not always the best policy
- * and special care should be taken for SD_NUMA domain level before
- * spreading the tasks. For now, load_balance() fully relies on
- * NUMA_BALANCING and fbq_classify_group/rq to override the decision.
*/
if (local->group_type == group_has_spare) {
if (busiest->group_type > group_fully_busy) {
@@ -8701,16 +8710,37 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
env->migration_type = migrate_task;
lsub_positive(&nr_diff, local->sum_nr_running);
env->imbalance = nr_diff >> 1;
- return;
- }
+ } else {
- /*
- * If there is no overload, we just want to even the number of
- * idle cpus.
- */
- env->migration_type = migrate_task;
- env->imbalance = max_t(long, 0, (local->idle_cpus -
+ /*
+ * If there is no overload, we just want to even the number of
+ * idle cpus.
+ */
+ env->migration_type = migrate_task;
+ env->imbalance = max_t(long, 0, (local->idle_cpus -
busiest->idle_cpus) >> 1);
+ }
+
+ /* Consider allowing a small imbalance between NUMA groups */
+ if (env->sd->flags & SD_NUMA) {
+ unsigned int imbalance_min;
+
+ /*
+ * Compute an allowed imbalance based on a simple
+ * pair of communicating tasks that should remain
+ * local and ignore them.
+ *
+ * NOTE: Generally this would have been based on
+ * the domain size and this was evaluated. However,
+ * the benefit is similar across a range of workloads
+ * and machines but scaling by the domain size adds
+ * the risk that lower domains have to be rebalanced.
+ */
+ imbalance_min = 2;
+ if (busiest->sum_nr_running <= imbalance_min)
+ env->imbalance = 0;
+ }
+
return;
}
diff --git a/kernel/sched/loadavg.c b/kernel/sched/loadavg.c
index 28a516575c18..de22da666ac7 100644
--- a/kernel/sched/loadavg.c
+++ b/kernel/sched/loadavg.c
@@ -231,16 +231,11 @@ static inline int calc_load_read_idx(void)
return calc_load_idx & 1;
}
-void calc_load_nohz_start(void)
+static void calc_load_nohz_fold(struct rq *rq)
{
- struct rq *this_rq = this_rq();
long delta;
- /*
- * We're going into NO_HZ mode, if there's any pending delta, fold it
- * into the pending NO_HZ delta.
- */
- delta = calc_load_fold_active(this_rq, 0);
+ delta = calc_load_fold_active(rq, 0);
if (delta) {
int idx = calc_load_write_idx();
@@ -248,6 +243,24 @@ void calc_load_nohz_start(void)
}
}
+void calc_load_nohz_start(void)
+{
+ /*
+ * We're going into NO_HZ mode, if there's any pending delta, fold it
+ * into the pending NO_HZ delta.
+ */
+ calc_load_nohz_fold(this_rq());
+}
+
+/*
+ * Keep track of the load for NOHZ_FULL, must be called between
+ * calc_load_nohz_{start,stop}().
+ */
+void calc_load_nohz_remote(struct rq *rq)
+{
+ calc_load_nohz_fold(rq);
+}
+
void calc_load_nohz_stop(void)
{
struct rq *this_rq = this_rq();
@@ -268,7 +281,7 @@ void calc_load_nohz_stop(void)
this_rq->calc_load_update += LOAD_FREQ;
}
-static long calc_load_nohz_fold(void)
+static long calc_load_nohz_read(void)
{
int idx = calc_load_read_idx();
long delta = 0;
@@ -323,7 +336,7 @@ static void calc_global_nohz(void)
}
#else /* !CONFIG_NO_HZ_COMMON */
-static inline long calc_load_nohz_fold(void) { return 0; }
+static inline long calc_load_nohz_read(void) { return 0; }
static inline void calc_global_nohz(void) { }
#endif /* CONFIG_NO_HZ_COMMON */
@@ -346,7 +359,7 @@ void calc_global_load(unsigned long ticks)
/*
* Fold the 'old' NO_HZ-delta to include all NO_HZ CPUs.
*/
- delta = calc_load_nohz_fold();
+ delta = calc_load_nohz_read();
if (delta)
atomic_long_add(delta, &calc_load_tasks);
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index ac4bd0ca11cc..028520702717 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -1199,6 +1199,9 @@ static ssize_t psi_write(struct file *file, const char __user *user_buf,
if (static_branch_likely(&psi_disabled))
return -EOPNOTSUPP;
+ if (!nbytes)
+ return -EINVAL;
+
buf_size = min(nbytes, sizeof(buf));
if (copy_from_user(buf, user_buf, buf_size))
return -EFAULT;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 1a88dc8ad11b..9ea647835fd6 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -896,7 +896,7 @@ struct rq {
*/
unsigned long nr_uninterruptible;
- struct task_struct *curr;
+ struct task_struct __rcu *curr;
struct task_struct *idle;
struct task_struct *stop;
unsigned long next_balance;
@@ -2479,3 +2479,16 @@ static inline void membarrier_switch_mm(struct rq *rq,
{
}
#endif
+
+#ifdef CONFIG_SMP
+static inline bool is_per_cpu_kthread(struct task_struct *p)
+{
+ if (!(p->flags & PF_KTHREAD))
+ return false;
+
+ if (p->nr_cpus_allowed != 1)
+ return false;
+
+ return true;
+}
+#endif
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index e7ce7cdac62f..483b3fd1094f 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1798,6 +1798,60 @@ void synth_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
}
EXPORT_SYMBOL_GPL(synth_event_cmd_init);
+static inline int
+__synth_event_trace_start(struct trace_event_file *file,
+ struct synth_event_trace_state *trace_state)
+{
+ int entry_size, fields_size = 0;
+ int ret = 0;
+
+ /*
+ * Normal event tracing doesn't get called at all unless the
+ * ENABLED bit is set (which attaches the probe thus allowing
+ * this code to be called, etc). Because this is called
+ * directly by the user, we don't have that but we still need
+ * to honor not logging when disabled. For the the iterated
+ * trace case, we save the enabed state upon start and just
+ * ignore the following data calls.
+ */
+ if (!(file->flags & EVENT_FILE_FL_ENABLED) ||
+ trace_trigger_soft_disabled(file)) {
+ trace_state->disabled = true;
+ ret = -ENOENT;
+ goto out;
+ }
+
+ trace_state->event = file->event_call->data;
+
+ fields_size = trace_state->event->n_u64 * sizeof(u64);
+
+ /*
+ * Avoid ring buffer recursion detection, as this event
+ * is being performed within another event.
+ */
+ trace_state->buffer = file->tr->array_buffer.buffer;
+ ring_buffer_nest_start(trace_state->buffer);
+
+ entry_size = sizeof(*trace_state->entry) + fields_size;
+ trace_state->entry = trace_event_buffer_reserve(&trace_state->fbuffer,
+ file,
+ entry_size);
+ if (!trace_state->entry) {
+ ring_buffer_nest_end(trace_state->buffer);
+ ret = -EINVAL;
+ }
+out:
+ return ret;
+}
+
+static inline void
+__synth_event_trace_end(struct synth_event_trace_state *trace_state)
+{
+ trace_event_buffer_commit(&trace_state->fbuffer);
+
+ ring_buffer_nest_end(trace_state->buffer);
+}
+
/**
* synth_event_trace - Trace a synthetic event
* @file: The trace_event_file representing the synthetic event
@@ -1819,71 +1873,38 @@ EXPORT_SYMBOL_GPL(synth_event_cmd_init);
*/
int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
{
- struct trace_event_buffer fbuffer;
- struct synth_trace_event *entry;
- struct trace_buffer *buffer;
- struct synth_event *event;
+ struct synth_event_trace_state state;
unsigned int i, n_u64;
- int fields_size = 0;
va_list args;
- int ret = 0;
-
- /*
- * Normal event generation doesn't get called at all unless
- * the ENABLED bit is set (which attaches the probe thus
- * allowing this code to be called, etc). Because this is
- * called directly by the user, we don't have that but we
- * still need to honor not logging when disabled.
- */
- if (!(file->flags & EVENT_FILE_FL_ENABLED))
- return 0;
-
- event = file->event_call->data;
-
- if (n_vals != event->n_fields)
- return -EINVAL;
-
- if (trace_trigger_soft_disabled(file))
- return -EINVAL;
-
- fields_size = event->n_u64 * sizeof(u64);
-
- /*
- * Avoid ring buffer recursion detection, as this event
- * is being performed within another event.
- */
- buffer = file->tr->array_buffer.buffer;
- ring_buffer_nest_start(buffer);
+ int ret;
- entry = trace_event_buffer_reserve(&fbuffer, file,
- sizeof(*entry) + fields_size);
- if (!entry) {
- ret = -EINVAL;
- goto out;
+ ret = __synth_event_trace_start(file, &state);
+ if (ret) {
+ if (ret == -ENOENT)
+ ret = 0; /* just disabled, not really an error */
+ return ret;
}
va_start(args, n_vals);
- for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
+ for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
u64 val;
val = va_arg(args, u64);
- if (event->fields[i]->is_string) {
+ if (state.event->fields[i]->is_string) {
char *str_val = (char *)(long)val;
- char *str_field = (char *)&entry->fields[n_u64];
+ char *str_field = (char *)&state.entry->fields[n_u64];
strscpy(str_field, str_val, STR_VAR_LEN_MAX);
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
} else {
- entry->fields[n_u64] = val;
+ state.entry->fields[n_u64] = val;
n_u64++;
}
}
va_end(args);
- trace_event_buffer_commit(&fbuffer);
-out:
- ring_buffer_nest_end(buffer);
+ __synth_event_trace_end(&state);
return ret;
}
@@ -1910,64 +1931,31 @@ EXPORT_SYMBOL_GPL(synth_event_trace);
int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
unsigned int n_vals)
{
- struct trace_event_buffer fbuffer;
- struct synth_trace_event *entry;
- struct trace_buffer *buffer;
- struct synth_event *event;
+ struct synth_event_trace_state state;
unsigned int i, n_u64;
- int fields_size = 0;
- int ret = 0;
-
- /*
- * Normal event generation doesn't get called at all unless
- * the ENABLED bit is set (which attaches the probe thus
- * allowing this code to be called, etc). Because this is
- * called directly by the user, we don't have that but we
- * still need to honor not logging when disabled.
- */
- if (!(file->flags & EVENT_FILE_FL_ENABLED))
- return 0;
-
- event = file->event_call->data;
-
- if (n_vals != event->n_fields)
- return -EINVAL;
-
- if (trace_trigger_soft_disabled(file))
- return -EINVAL;
-
- fields_size = event->n_u64 * sizeof(u64);
-
- /*
- * Avoid ring buffer recursion detection, as this event
- * is being performed within another event.
- */
- buffer = file->tr->array_buffer.buffer;
- ring_buffer_nest_start(buffer);
+ int ret;
- entry = trace_event_buffer_reserve(&fbuffer, file,
- sizeof(*entry) + fields_size);
- if (!entry) {
- ret = -EINVAL;
- goto out;
+ ret = __synth_event_trace_start(file, &state);
+ if (ret) {
+ if (ret == -ENOENT)
+ ret = 0; /* just disabled, not really an error */
+ return ret;
}
- for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
- if (event->fields[i]->is_string) {
+ for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
+ if (state.event->fields[i]->is_string) {
char *str_val = (char *)(long)vals[i];
- char *str_field = (char *)&entry->fields[n_u64];
+ char *str_field = (char *)&state.entry->fields[n_u64];
strscpy(str_field, str_val, STR_VAR_LEN_MAX);
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
} else {
- entry->fields[n_u64] = vals[i];
+ state.entry->fields[n_u64] = vals[i];
n_u64++;
}
}
- trace_event_buffer_commit(&fbuffer);
-out:
- ring_buffer_nest_end(buffer);
+ __synth_event_trace_end(&state);
return ret;
}
@@ -2004,58 +1992,17 @@ EXPORT_SYMBOL_GPL(synth_event_trace_array);
int synth_event_trace_start(struct trace_event_file *file,
struct synth_event_trace_state *trace_state)
{
- struct synth_trace_event *entry;
- int fields_size = 0;
- int ret = 0;
+ int ret;
- if (!trace_state) {
- ret = -EINVAL;
- goto out;
- }
+ if (!trace_state)
+ return -EINVAL;
memset(trace_state, '\0', sizeof(*trace_state));
- /*
- * Normal event tracing doesn't get called at all unless the
- * ENABLED bit is set (which attaches the probe thus allowing
- * this code to be called, etc). Because this is called
- * directly by the user, we don't have that but we still need
- * to honor not logging when disabled. For the the iterated
- * trace case, we save the enabed state upon start and just
- * ignore the following data calls.
- */
- if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
- trace_state->enabled = false;
- goto out;
- }
-
- trace_state->enabled = true;
-
- trace_state->event = file->event_call->data;
-
- if (trace_trigger_soft_disabled(file)) {
- ret = -EINVAL;
- goto out;
- }
+ ret = __synth_event_trace_start(file, trace_state);
+ if (ret == -ENOENT)
+ ret = 0; /* just disabled, not really an error */
- fields_size = trace_state->event->n_u64 * sizeof(u64);
-
- /*
- * Avoid ring buffer recursion detection, as this event
- * is being performed within another event.
- */
- trace_state->buffer = file->tr->array_buffer.buffer;
- ring_buffer_nest_start(trace_state->buffer);
-
- entry = trace_event_buffer_reserve(&trace_state->fbuffer, file,
- sizeof(*entry) + fields_size);
- if (!entry) {
- ret = -EINVAL;
- goto out;
- }
-
- trace_state->entry = entry;
-out:
return ret;
}
EXPORT_SYMBOL_GPL(synth_event_trace_start);
@@ -2088,7 +2035,7 @@ static int __synth_event_add_val(const char *field_name, u64 val,
trace_state->add_next = true;
}
- if (!trace_state->enabled)
+ if (trace_state->disabled)
goto out;
event = trace_state->event;
@@ -2223,9 +2170,7 @@ int synth_event_trace_end(struct synth_event_trace_state *trace_state)
if (!trace_state)
return -EINVAL;
- trace_event_buffer_commit(&trace_state->fbuffer);
-
- ring_buffer_nest_end(trace_state->buffer);
+ __synth_event_trace_end(trace_state);
return 0;
}
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index d8264ebb9581..362cca52f5de 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1012,7 +1012,7 @@ int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...)
{
struct dynevent_arg arg;
va_list args;
- int ret;
+ int ret = 0;
if (cmd->type != DYNEVENT_TYPE_KPROBE)
return -EINVAL;