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authorIngo Molnar <mingo@elte.hu>2007-08-09 11:16:46 +0200
committerIngo Molnar <mingo@elte.hu>2007-08-09 11:16:46 +0200
commit8e717b194ce3f3ac9e6acc63f66fe274cdf9cde1 (patch)
tree8fee6962d5d148dbfd013eb0111cc015da2b3067
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>
-rw-r--r--kernel/sched.c19
1 files changed, 9 insertions, 10 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 0112f63ad37..49f5b281c56 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)
/*
* deactivate_task - remove a task from the runqueue.
*/
-static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep)
+static void
+deactivate_task(struct rq *rq, struct task_struct *p, int sleep, u64 now)
{
- u64 now = rq_clock(rq);
-
if (p->state == TASK_UNINTERRUPTIBLE)
rq->nr_uninterruptible++;
@@ -2122,7 +2121,7 @@ void sched_exec(void)
static void pull_task(struct rq *src_rq, struct task_struct *p,
struct rq *this_rq, int this_cpu)
{
- deactivate_task(src_rq, p, 0);
+ deactivate_task(src_rq, p, 0, rq_clock(src_rq));
set_task_cpu(p, this_cpu);
activate_task(this_rq, p, 0);
/*
@@ -3446,13 +3445,14 @@ need_resched_nonpreemptible:
spin_lock_irq(&rq->lock);
clear_tsk_need_resched(prev);
+ now = __rq_clock(rq);
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
if (unlikely((prev->state & TASK_INTERRUPTIBLE) &&
unlikely(signal_pending(prev)))) {
prev->state = TASK_RUNNING;
} else {
- deactivate_task(rq, prev, 1);
+ deactivate_task(rq, prev, 1, now);
}
switch_count = &prev->nvcsw;
}
@@ -3460,7 +3460,6 @@ need_resched_nonpreemptible:
if (unlikely(!rq->nr_running))
idle_balance(cpu, rq);
- now = __rq_clock(rq);
prev->sched_class->put_prev_task(rq, prev, now);
next = pick_next_task(rq, prev, now);
@@ -4220,7 +4219,7 @@ recheck:
}
on_rq = p->se.on_rq;
if (on_rq)
- deactivate_task(rq, p, 0);
+ deactivate_task(rq, p, 0, rq_clock(rq));
oldprio = p->prio;
__setscheduler(rq, p, policy, param->sched_priority);
if (on_rq) {
@@ -4973,7 +4972,7 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
on_rq = p->se.on_rq;
if (on_rq)
- deactivate_task(rq_src, p, 0);
+ deactivate_task(rq_src, p, 0, rq_clock(rq_src));
set_task_cpu(p, dest_cpu);
if (on_rq) {
activate_task(rq_dest, p, 0);
@@ -5387,7 +5386,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
rq->migration_thread = NULL;
/* Idle task back to normal (off runqueue, low prio) */
rq = task_rq_lock(rq->idle, &flags);
- deactivate_task(rq, rq->idle, 0);
+ deactivate_task(rq, rq->idle, 0, rq_clock(rq));
rq->idle->static_prio = MAX_PRIO;
__setscheduler(rq, rq->idle, SCHED_NORMAL, 0);
rq->idle->sched_class = &idle_sched_class;
@@ -6626,7 +6625,7 @@ void normalize_rt_tasks(void)
on_rq = p->se.on_rq;
if (on_rq)
- deactivate_task(task_rq(p), p, 0);
+ deactivate_task(task_rq(p), p, 0, rq_clock(task_rq(p)));
__setscheduler(rq, p, SCHED_NORMAL, 0);
if (on_rq) {
activate_task(task_rq(p), p, 0);