В Вт, 24/02/2015 в 09:28 +0000, Juri Lelli пишет: > dl_task_timer() may fire on a different rq from where a task was removed > after throttling. Since the call path is: > > dl_task_timer() -> > enqueue_task_dl() -> > enqueue_dl_entity() -> > replenish_dl_entity() > > and replenish_dl_entity() uses dl_se's rq, we can't use current's rq > in dl_task_timer(), but we need to lock the task's previous one. > > Signed-off-by: Juri Lelli <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Kirill Tkhai <[email protected]> > Cc: Juri Lelli <[email protected]> > Cc: [email protected] > Fixes: 3960c8c0c789 ("sched: Make dl_task_time() use task_rq_lock()")
Acked-by: Kirill Tkhai <[email protected]> 3960c8c0c789 is already in Linus's tree, so this is a candidate for 4.0 too. > --- > kernel/sched/deadline.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > index dbf12a9..519e468 100644 > --- a/kernel/sched/deadline.c > +++ b/kernel/sched/deadline.c > @@ -538,7 +538,7 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer > *timer) > unsigned long flags; > struct rq *rq; > > - rq = task_rq_lock(current, &flags); > + rq = task_rq_lock(p, &flags); > > /* > * We need to take care of several possible races here: > @@ -593,7 +593,7 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer > *timer) > push_dl_task(rq); > #endif > unlock: > - task_rq_unlock(rq, current, &flags); > + task_rq_unlock(rq, p, &flags); > > return HRTIMER_NORESTART; > } Thanks, Kirill -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
