sched: Resched proper CPU on yield_to()

yield_to_task_fair() has code to resched the CPU of yielding task when the
intention is to resched the CPU of the task that is being yielded to.

Change here fixes the problem and also makes the resched conditional on
rq != p_rq.

Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1299025701-22168-1-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Venkatesh Pallipadi 2011-03-01 16:28:21 -08:00 committed by Ingo Molnar
parent c02aa73b1d
commit 6d1cafd8b5
2 changed files with 8 additions and 5 deletions

View file

@ -5522,8 +5522,15 @@ bool __sched yield_to(struct task_struct *p, bool preempt)
goto out;
yielded = curr->sched_class->yield_to_task(rq, p, preempt);
if (yielded)
if (yielded) {
schedstat_inc(rq, yld_count);
/*
* Make p's CPU reschedule; pick_next_entity takes care of
* fairness.
*/
if (preempt && rq != p_rq)
resched_task(p_rq->curr);
}
out:
double_rq_unlock(rq, p_rq);

View file

@ -1987,10 +1987,6 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp
/* Tell the scheduler that we'd really like pse to run next. */
set_next_buddy(se);
/* Make p's CPU reschedule; pick_next_entity takes care of fairness. */
if (preempt)
resched_task(rq->curr);
yield_task_fair(rq);
return true;