diff options
authorIngo Molnar <mingo@elte.hu>2007-03-28 13:17:18 +0200
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-03-28 13:44:31 -0700
commit935c631db827cc3a96df4dcc6fec374b994fdbd1 (patch)
parentde326dbe0c8b61b81aab32970236ee9ee47d782a (diff)
[PATCH] hrtimers: fix reprogramming SMP race
hrtimer_start() incorrectly set the 'reprogram' flag to enqueue_hrtimer(), which should only be 1 if the hrtimer is queued to the current CPU. Doing otherwise could result in a reprogramming of the current CPU's clockevents device, with a timer that is not queued to it - resulting in a bogus next expiry value. Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Michal Piotrowski <michal.k.k.piotrowski@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 6 insertions, 1 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 6a7938a0d513..067ba2c05328 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -814,7 +814,12 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
- enqueue_hrtimer(timer, new_base, base == new_base);
+ /*
+ * Only allow reprogramming if the new base is on this CPU.
+ * (it might still be on another CPU if the timer was pending)
+ */
+ enqueue_hrtimer(timer, new_base,
+ new_base->cpu_base == &__get_cpu_var(hrtimer_bases));
unlock_hrtimer_base(timer, &flags);