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authorIngo Molnar <mingo@elte.hu>2007-08-09 05:16:46 -0400
committerIngo Molnar <mingo@elte.hu>2007-08-09 05:16:46 -0400
commit8e717b194ce3f3ac9e6acc63f66fe274cdf9cde1 (patch)
tree8fee6962d5d148dbfd013eb0111cc015da2b3067 /kernel
parent7bfd0485871df01764ca89d5679f128d870aef1a (diff)
sched: schedule() speedup
speed up schedule(): share the 'now' parameter that deactivate_task() was calculating internally. ( this also fixes the small accounting window between the deactivate call and the pick_next_task() call. ) Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched.c19
1 files changed, 9 insertions, 10 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 0112f63ad376..49f5b281c561 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -940,10 +940,9 @@ static inline void activate_idle_task(struct task_struct *p, struct rq *rq)
940/* 940/*
941 * deactivate_task - remove a task from the runqueue. 941 * deactivate_task - remove a task from the runqueue.
942 */ 942 */
943static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep) 943static void
944deactivate_task(struct rq *rq, struct task_struct *p, int sleep, u64 now)
944{ 945{
945 u64 now = rq_clock(rq);
946
947 if (p->state == TASK_UNINTERRUPTIBLE) 946 if (p->state == TASK_UNINTERRUPTIBLE)
948 rq->nr_uninterruptible++; 947 rq->nr_uninterruptible++;
949 948
@@ -2122,7 +2121,7 @@ void sched_exec(void)
2122static void pull_task(struct rq *src_rq, struct task_struct *p, 2121static void pull_task(struct rq *src_rq, struct task_struct *p,
2123 struct rq *this_rq, int this_cpu) 2122 struct rq *this_rq, int this_cpu)
2124{ 2123{
2125 deactivate_task(src_rq, p, 0); 2124 deactivate_task(src_rq, p, 0, rq_clock(src_rq));
2126 set_task_cpu(p, this_cpu); 2125 set_task_cpu(p, this_cpu);
2127 activate_task(this_rq, p, 0); 2126 activate_task(this_rq, p, 0);
2128 /* 2127 /*
@@ -3446,13 +3445,14 @@ need_resched_nonpreemptible:
3446 3445
3447 spin_lock_irq(&rq->lock); 3446 spin_lock_irq(&rq->lock);
3448 clear_tsk_need_resched(prev); 3447 clear_tsk_need_resched(prev);
3448 now = __rq_clock(rq);
3449 3449
3450 if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { 3450 if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
3451 if (unlikely((prev->state & TASK_INTERRUPTIBLE) && 3451 if (unlikely((prev->state & TASK_INTERRUPTIBLE) &&
3452 unlikely(signal_pending(prev)))) { 3452 unlikely(signal_pending(prev)))) {
3453 prev->state = TASK_RUNNING; 3453 prev->state = TASK_RUNNING;
3454 } else { 3454 } else {
3455 deactivate_task(rq, prev, 1); 3455 deactivate_task(rq, prev, 1, now);
3456 } 3456 }
3457 switch_count = &prev->nvcsw; 3457 switch_count = &prev->nvcsw;
3458 } 3458 }
@@ -3460,7 +3460,6 @@ need_resched_nonpreemptible:
3460 if (unlikely(!rq->nr_running)) 3460 if (unlikely(!rq->nr_running))
3461 idle_balance(cpu, rq); 3461 idle_balance(cpu, rq);
3462 3462
3463 now = __rq_clock(rq);
3464 prev->sched_class->put_prev_task(rq, prev, now); 3463 prev->sched_class->put_prev_task(rq, prev, now);
3465 next = pick_next_task(rq, prev, now); 3464 next = pick_next_task(rq, prev, now);
3466 3465
@@ -4220,7 +4219,7 @@ recheck:
4220 } 4219 }
4221 on_rq = p->se.on_rq; 4220 on_rq = p->se.on_rq;
4222 if (on_rq) 4221 if (on_rq)
4223 deactivate_task(rq, p, 0); 4222 deactivate_task(rq, p, 0, rq_clock(rq));
4224 oldprio = p->prio; 4223 oldprio = p->prio;
4225 __setscheduler(rq, p, policy, param->sched_priority); 4224 __setscheduler(rq, p, policy, param->sched_priority);
4226 if (on_rq) { 4225 if (on_rq) {
@@ -4973,7 +4972,7 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
4973 4972
4974 on_rq = p->se.on_rq; 4973 on_rq = p->se.on_rq;
4975 if (on_rq) 4974 if (on_rq)
4976 deactivate_task(rq_src, p, 0); 4975 deactivate_task(rq_src, p, 0, rq_clock(rq_src));
4977 set_task_cpu(p, dest_cpu); 4976 set_task_cpu(p, dest_cpu);
4978 if (on_rq) { 4977 if (on_rq) {
4979 activate_task(rq_dest, p, 0); 4978 activate_task(rq_dest, p, 0);
@@ -5387,7 +5386,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
5387 rq->migration_thread = NULL; 5386 rq->migration_thread = NULL;
5388 /* Idle task back to normal (off runqueue, low prio) */ 5387 /* Idle task back to normal (off runqueue, low prio) */
5389 rq = task_rq_lock(rq->idle, &flags); 5388 rq = task_rq_lock(rq->idle, &flags);
5390 deactivate_task(rq, rq->idle, 0); 5389 deactivate_task(rq, rq->idle, 0, rq_clock(rq));
5391 rq->idle->static_prio = MAX_PRIO; 5390 rq->idle->static_prio = MAX_PRIO;
5392 __setscheduler(rq, rq->idle, SCHED_NORMAL, 0); 5391 __setscheduler(rq, rq->idle, SCHED_NORMAL, 0);
5393 rq->idle->sched_class = &idle_sched_class; 5392 rq->idle->sched_class = &idle_sched_class;
@@ -6626,7 +6625,7 @@ void normalize_rt_tasks(void)
6626 6625
6627 on_rq = p->se.on_rq; 6626 on_rq = p->se.on_rq;
6628 if (on_rq) 6627 if (on_rq)
6629 deactivate_task(task_rq(p), p, 0); 6628 deactivate_task(task_rq(p), p, 0, rq_clock(task_rq(p)));
6630 __setscheduler(rq, p, SCHED_NORMAL, 0); 6629 __setscheduler(rq, p, SCHED_NORMAL, 0);
6631 if (on_rq) { 6630 if (on_rq) {
6632 activate_task(task_rq(p), p, 0); 6631 activate_task(task_rq(p), p, 0);