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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-03-28 21:21:23 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-03-28 21:21:23 +0300 |
| commit | 4a89452e70a019cb6bfb1114b12f2607c3bace24 (patch) | |
| tree | 4744009041b3fb9d2b78621d2f6ab42c01b1cb3a /kernel | |
| parent | 19dba4f3e9f7fef811cf446e15f578887762528a (diff) | |
| parent | 6e206020324c50a95486f6b279a53512febed92d (diff) | |
| download | linux-4a89452e70a019cb6bfb1114b12f2607c3bace24.tar.xz | |
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Ingo Molnar:
"Two clocksource driver fixes, and an idle loop RCU warning fix"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource/drivers/sun5i: Fix cpufreq interaction with sched_clock()
clocksource/drivers: Fix various !CONFIG_HAS_IOMEM build errors
timers/tick/broadcast-hrtimer: Fix suspicious RCU usage in idle loop
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/time/tick-broadcast-hrtimer.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/kernel/time/tick-broadcast-hrtimer.c b/kernel/time/tick-broadcast-hrtimer.c index eb682d5c697c..6aac4beedbbe 100644 --- a/kernel/time/tick-broadcast-hrtimer.c +++ b/kernel/time/tick-broadcast-hrtimer.c @@ -49,6 +49,7 @@ static void bc_set_mode(enum clock_event_mode mode, */ static int bc_set_next(ktime_t expires, struct clock_event_device *bc) { + int bc_moved; /* * We try to cancel the timer first. If the callback is on * flight on some other cpu then we let it handle it. If we @@ -60,9 +61,15 @@ static int bc_set_next(ktime_t expires, struct clock_event_device *bc) * restart the timer because we are in the callback, but we * can set the expiry time and let the callback return * HRTIMER_RESTART. + * + * Since we are in the idle loop at this point and because + * hrtimer_{start/cancel} functions call into tracing, + * calls to these functions must be bound within RCU_NONIDLE. */ - if (hrtimer_try_to_cancel(&bctimer) >= 0) { - hrtimer_start(&bctimer, expires, HRTIMER_MODE_ABS_PINNED); + RCU_NONIDLE(bc_moved = (hrtimer_try_to_cancel(&bctimer) >= 0) ? + !hrtimer_start(&bctimer, expires, HRTIMER_MODE_ABS_PINNED) : + 0); + if (bc_moved) { /* Bind the "device" to the cpu */ bc->bound_on = smp_processor_id(); } else if (bc->bound_on == smp_processor_id()) { |