sched: optimize activate_task()
optimize activate_task() by removing update_rq_clock() from it.
(and add update_rq_clock() to all callsites of activate_task() that
did not have it before.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index 3f5d529..9ccd91e 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -910,8 +910,6 @@
*/
static void activate_task(struct rq *rq, struct task_struct *p, int wakeup)
{
- update_rq_clock(rq);
-
if (p->state == TASK_UNINTERRUPTIBLE)
rq->nr_uninterruptible--;
@@ -1510,6 +1508,7 @@
out_activate:
#endif /* CONFIG_SMP */
+ update_rq_clock(rq);
activate_task(rq, p, 1);
/*
* Sync wakeups (i.e. those types of wakeups where the waker
@@ -2117,6 +2116,7 @@
update_rq_clock(src_rq);
deactivate_task(src_rq, p, 0);
set_task_cpu(p, this_cpu);
+ __update_rq_clock(this_rq);
activate_task(this_rq, p, 0);
/*
* Note that idle threads have a prio of MAX_PRIO, for this test
@@ -4207,11 +4207,10 @@
spin_unlock_irqrestore(&p->pi_lock, flags);
goto recheck;
}
+ update_rq_clock(rq);
on_rq = p->se.on_rq;
- if (on_rq) {
- update_rq_clock(rq);
+ if (on_rq)
deactivate_task(rq, p, 0);
- }
oldprio = p->prio;
__setscheduler(rq, p, policy, param->sched_priority);
if (on_rq) {
@@ -4969,6 +4968,7 @@
}
set_task_cpu(p, dest_cpu);
if (on_rq) {
+ update_rq_clock(rq_dest);
activate_task(rq_dest, p, 0);
check_preempt_curr(rq_dest, p);
}
@@ -6623,14 +6623,13 @@
goto out_unlock;
#endif
+ update_rq_clock(rq);
on_rq = p->se.on_rq;
- if (on_rq) {
- update_rq_clock(task_rq(p));
- deactivate_task(task_rq(p), p, 0);
- }
+ if (on_rq)
+ deactivate_task(rq, p, 0);
__setscheduler(rq, p, SCHED_NORMAL, 0);
if (on_rq) {
- activate_task(task_rq(p), p, 0);
+ activate_task(rq, p, 0);
resched_task(rq->curr);
}
#ifdef CONFIG_SMP
