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: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 061ae28..bd5d6b5 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1293,7 +1293,7 @@
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 @@
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();