Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Thomas Gleixner:
"Fix a potential deadlock versus hrtimers"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Fix HRTICK
+11
-9
+11
-9
kernel/sched/core.c
+11
-9
kernel/sched/core.c
···
370
370
#ifdef CONFIG_SCHED_HRTICK
371
371
/*
372
372
* Use HR-timers to deliver accurate preemption points.
373
-
*
374
-
* Its all a bit involved since we cannot program an hrt while holding the
375
-
* rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a
376
-
* reschedule event.
377
-
*
378
-
* When we get rescheduled we reprogram the hrtick_timer outside of the
379
-
* rq->lock.
380
373
*/
381
374
382
375
static void hrtick_clear(struct rq *rq)
···
397
404
}
398
405
399
406
#ifdef CONFIG_SMP
407
+
408
+
static int __hrtick_restart(struct rq *rq)
409
+
{
410
+
struct hrtimer *timer = &rq->hrtick_timer;
411
+
ktime_t time = hrtimer_get_softexpires(timer);
412
+
413
+
return __hrtimer_start_range_ns(timer, time, 0, HRTIMER_MODE_ABS_PINNED, 0);
414
+
}
415
+
400
416
/*
401
417
* called from hardirq (IPI) context
402
418
*/
···
414
412
struct rq *rq = arg;
415
413
416
414
raw_spin_lock(&rq->lock);
417
-
hrtimer_restart(&rq->hrtick_timer);
415
+
__hrtick_restart(rq);
418
416
rq->hrtick_csd_pending = 0;
419
417
raw_spin_unlock(&rq->lock);
420
418
}
···
432
430
hrtimer_set_expires(timer, time);
433
431
434
432
if (rq == this_rq()) {
435
-
hrtimer_restart(timer);
433
+
__hrtick_restart(rq);
436
434
} else if (!rq->hrtick_csd_pending) {
437
435
__smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0);
438
436
rq->hrtick_csd_pending = 1;