summaryrefslogtreecommitdiff
path: root/kernel/sched.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c145
1 files changed, 37 insertions, 108 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 49d2fa7b687a..52b7efd27416 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -492,8 +492,11 @@ struct rq {
#define CPU_LOAD_IDX_MAX 5
unsigned long cpu_load[CPU_LOAD_IDX_MAX];
#ifdef CONFIG_NO_HZ
+ u64 nohz_stamp;
unsigned char in_nohz_recently;
#endif
+ unsigned int skip_clock_update;
+
/* capture load from *all* tasks on this cpu: */
struct load_weight load;
unsigned long nr_load_updates;
@@ -591,6 +594,13 @@ static inline
void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
{
rq->curr->sched_class->check_preempt_curr(rq, p, flags);
+
+ /*
+ * A queue event has occurred, and we're going to schedule. In
+ * this case, we can save a useless back to back clock update.
+ */
+ if (test_tsk_need_resched(p))
+ rq->skip_clock_update = 1;
}
static inline int cpu_of(struct rq *rq)
@@ -625,7 +635,8 @@ static inline int cpu_of(struct rq *rq)
inline void update_rq_clock(struct rq *rq)
{
- rq->clock = sched_clock_cpu(cpu_of(rq));
+ if (!rq->skip_clock_update)
+ rq->clock = sched_clock_cpu(cpu_of(rq));
}
/*
@@ -1228,6 +1239,17 @@ void wake_up_idle_cpu(int cpu)
if (!tsk_is_polling(rq->idle))
smp_send_reschedule(cpu);
}
+
+int nohz_ratelimit(int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+ u64 diff = rq->clock - rq->nohz_stamp;
+
+ rq->nohz_stamp = rq->clock;
+
+ return diff < (NSEC_PER_SEC / HZ) >> 1;
+}
+
#endif /* CONFIG_NO_HZ */
static u64 sched_avg_period(void)
@@ -1770,8 +1792,6 @@ static void double_rq_lock(struct rq *rq1, struct rq *rq2)
raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
}
}
- update_rq_clock(rq1);
- update_rq_clock(rq2);
}
/*
@@ -1868,9 +1888,7 @@ static void update_avg(u64 *avg, u64 sample)
static void
enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, bool head)
{
- if (wakeup)
- p->se.start_runtime = p->se.sum_exec_runtime;
-
+ update_rq_clock(rq);
sched_info_queued(p);
p->sched_class->enqueue_task(rq, p, wakeup, head);
p->se.on_rq = 1;
@@ -1878,17 +1896,7 @@ enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, bool head)
static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep)
{
- if (sleep) {
- if (p->se.last_wakeup) {
- update_avg(&p->se.avg_overlap,
- p->se.sum_exec_runtime - p->se.last_wakeup);
- p->se.last_wakeup = 0;
- } else {
- update_avg(&p->se.avg_wakeup,
- sysctl_sched_wakeup_granularity);
- }
- }
-
+ update_rq_clock(rq);
sched_info_dequeued(p);
p->sched_class->dequeue_task(rq, p, sleep);
p->se.on_rq = 0;
@@ -2361,14 +2369,10 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
unsigned long flags;
struct rq *rq;
- if (!sched_feat(SYNC_WAKEUPS))
- wake_flags &= ~WF_SYNC;
-
this_cpu = get_cpu();
smp_wmb();
rq = task_rq_lock(p, &flags);
- update_rq_clock(rq);
if (!(p->state & state))
goto out;
@@ -2409,7 +2413,6 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
rq = cpu_rq(cpu);
raw_spin_lock(&rq->lock);
- update_rq_clock(rq);
/*
* We migrated the task without holding either rq->lock, however
@@ -2437,34 +2440,18 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
out_activate:
#endif /* CONFIG_SMP */
- schedstat_inc(p, se.nr_wakeups);
+ schedstat_inc(p, se.statistics.nr_wakeups);
if (wake_flags & WF_SYNC)
- schedstat_inc(p, se.nr_wakeups_sync);
+ schedstat_inc(p, se.statistics.nr_wakeups_sync);
if (orig_cpu != cpu)
- schedstat_inc(p, se.nr_wakeups_migrate);
+ schedstat_inc(p, se.statistics.nr_wakeups_migrate);
if (cpu == this_cpu)
- schedstat_inc(p, se.nr_wakeups_local);
+ schedstat_inc(p, se.statistics.nr_wakeups_local);
else
- schedstat_inc(p, se.nr_wakeups_remote);
+ schedstat_inc(p, se.statistics.nr_wakeups_remote);
activate_task(rq, p, 1);
success = 1;
- /*
- * Only attribute actual wakeups done by this task.
- */
- if (!in_interrupt()) {
- struct sched_entity *se = &current->se;
- u64 sample = se->sum_exec_runtime;
-
- if (se->last_wakeup)
- sample -= se->last_wakeup;
- else
- sample -= se->start_runtime;
- update_avg(&se->avg_wakeup, sample);
-
- se->last_wakeup = se->sum_exec_runtime;
- }
-
out_running:
trace_sched_wakeup(rq, p, success);
check_preempt_curr(rq, p, wake_flags);
@@ -2526,42 +2513,9 @@ static void __sched_fork(struct task_struct *p)
p->se.sum_exec_runtime = 0;
p->se.prev_sum_exec_runtime = 0;
p->se.nr_migrations = 0;
- p->se.last_wakeup = 0;
- p->se.avg_overlap = 0;
- p->se.start_runtime = 0;
- p->se.avg_wakeup = sysctl_sched_wakeup_granularity;
#ifdef CONFIG_SCHEDSTATS
- p->se.wait_start = 0;
- p->se.wait_max = 0;
- p->se.wait_count = 0;
- p->se.wait_sum = 0;
-
- p->se.sleep_start = 0;
- p->se.sleep_max = 0;
- p->se.sum_sleep_runtime = 0;
-
- p->se.block_start = 0;
- p->se.block_max = 0;
- p->se.exec_max = 0;
- p->se.slice_max = 0;
-
- p->se.nr_migrations_cold = 0;
- p->se.nr_failed_migrations_affine = 0;
- p->se.nr_failed_migrations_running = 0;
- p->se.nr_failed_migrations_hot = 0;
- p->se.nr_forced_migrations = 0;
-
- p->se.nr_wakeups = 0;
- p->se.nr_wakeups_sync = 0;
- p->se.nr_wakeups_migrate = 0;
- p->se.nr_wakeups_local = 0;
- p->se.nr_wakeups_remote = 0;
- p->se.nr_wakeups_affine = 0;
- p->se.nr_wakeups_affine_attempts = 0;
- p->se.nr_wakeups_passive = 0;
- p->se.nr_wakeups_idle = 0;
-
+ memset(&p->se.statistics, 0, sizeof(p->se.statistics));
#endif
INIT_LIST_HEAD(&p->rt.run_list);
@@ -2675,7 +2629,6 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
BUG_ON(p->state != TASK_WAKING);
p->state = TASK_RUNNING;
- update_rq_clock(rq);
activate_task(rq, p, 0);
trace_sched_wakeup_new(rq, p, 1);
check_preempt_curr(rq, p, WF_FORK);
@@ -3629,23 +3582,9 @@ static inline void schedule_debug(struct task_struct *prev)
static void put_prev_task(struct rq *rq, struct task_struct *prev)
{
- if (prev->state == TASK_RUNNING) {
- u64 runtime = prev->se.sum_exec_runtime;
-
- runtime -= prev->se.prev_sum_exec_runtime;
- runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost);
-
- /*
- * In order to avoid avg_overlap growing stale when we are
- * indeed overlapping and hence not getting put to sleep, grow
- * the avg_overlap on preemption.
- *
- * We use the average preemption runtime because that
- * correlates to the amount of cache footprint a task can
- * build up.
- */
- update_avg(&prev->se.avg_overlap, runtime);
- }
+ if (prev->se.on_rq)
+ update_rq_clock(rq);
+ rq->skip_clock_update = 0;
prev->sched_class->put_prev_task(rq, prev);
}
@@ -3708,7 +3647,6 @@ need_resched_nonpreemptible:
hrtick_clear(rq);
raw_spin_lock_irq(&rq->lock);
- update_rq_clock(rq);
clear_tsk_need_resched(prev);
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
@@ -4265,7 +4203,6 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
BUG_ON(prio < 0 || prio > MAX_PRIO);
rq = task_rq_lock(p, &flags);
- update_rq_clock(rq);
oldprio = p->prio;
prev_class = p->sched_class;
@@ -4308,7 +4245,6 @@ void set_user_nice(struct task_struct *p, long nice)
* the task might be in the middle of scheduling on another CPU.
*/
rq = task_rq_lock(p, &flags);
- update_rq_clock(rq);
/*
* The RT priorities are set via sched_setscheduler(), but we still
* allow the 'normal' nice value to be set - but as expected
@@ -4591,7 +4527,6 @@ recheck:
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
goto recheck;
}
- update_rq_clock(rq);
on_rq = p->se.on_rq;
running = task_current(rq, p);
if (on_rq)
@@ -5602,7 +5537,6 @@ void sched_idle_next(void)
__setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1);
- update_rq_clock(rq);
activate_task(rq, p, 0);
raw_spin_unlock_irqrestore(&rq->lock, flags);
@@ -5657,7 +5591,6 @@ static void migrate_dead_tasks(unsigned int dead_cpu)
for ( ; ; ) {
if (!rq->nr_running)
break;
- update_rq_clock(rq);
next = pick_next_task(rq);
if (!next)
break;
@@ -5941,7 +5874,6 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
rq->migration_thread = NULL;
/* Idle task back to normal (off runqueue, low prio) */
raw_spin_lock_irq(&rq->lock);
- update_rq_clock(rq);
deactivate_task(rq, rq->idle, 0);
__setscheduler(rq, rq->idle, SCHED_NORMAL, 0);
rq->idle->sched_class = &idle_sched_class;
@@ -7891,7 +7823,6 @@ static void normalize_task(struct rq *rq, struct task_struct *p)
{
int on_rq;
- update_rq_clock(rq);
on_rq = p->se.on_rq;
if (on_rq)
deactivate_task(rq, p, 0);
@@ -7918,9 +7849,9 @@ void normalize_rt_tasks(void)
p->se.exec_start = 0;
#ifdef CONFIG_SCHEDSTATS
- p->se.wait_start = 0;
- p->se.sleep_start = 0;
- p->se.block_start = 0;
+ p->se.statistics.wait_start = 0;
+ p->se.statistics.sleep_start = 0;
+ p->se.statistics.block_start = 0;
#endif
if (!rt_task(p)) {
@@ -8253,8 +8184,6 @@ void sched_move_task(struct task_struct *tsk)
rq = task_rq_lock(tsk, &flags);
- update_rq_clock(rq);
-
running = task_current(rq, tsk);
on_rq = tsk->se.on_rq;
generated by cgit v1.2.3 (git 2.0.4) at 2025-02-10 17:43:53 +0000