Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 37bb6cb4 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

hrtimer: unlock hrtimer_wakeup 



hrtimer_wakeup creates a

  base->lock
    rq->lock

lock dependancy. Avoid this by switching to HRTIMER_CB_IRQSAFE_NO_SOFTIRQ
which doesn't hold base->lock.

This fully untangles hrtimer locks from the scheduler locks, and allows
hrtimer usage in the scheduler proper.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent d3d74453

kernel/hrtimer.c

+3 −1
Original line number Diff line number Diff line
@@ -1293,7 +1293,7 @@ void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task) 
	sl->timer.function = hrtimer_wakeup;

	sl->task = task;

#ifdef CONFIG_HIGH_RES_TIMERS

	sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_RESTART;

	sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;

#endif

}
@@ -1304,6 +1304,8 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod 
	do {

		set_current_state(TASK_INTERRUPTIBLE);

		hrtimer_start(&t->timer, t->timer.expires, mode);

		if (!hrtimer_active(&t->timer))

			t->task = NULL;



		if (likely(t->task))

			schedule();