| Date | Mon, 15 Jan 2018 19:49:07 -0800 | From | tip-bot for Anna-Maria Gleixner <> | Subject | [tip:timers/core] hrtimer: Make remote enqueue decision less restrictive |
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Commit-ID: 2ac2dccce9d16a7b1a8fddf69a955d249375bce4 Gitweb: https://git.kernel.org/tip/2ac2dccce9d16a7b1a8fddf69a955d249375bce4 Author: Anna-Maria Gleixner <anna-maria@linutronix.de> AuthorDate: Thu, 21 Dec 2017 11:41:50 +0100 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Tue, 16 Jan 2018 02:53:58 +0100
hrtimer: Make remote enqueue decision less restrictive
The current decision whether a timer can be queued on a remote CPU checks for timer->expiry <= remote_cpu_base.expires_next.
This is too restrictive because a timer with the same expiry time as an existing timer will be enqueued on right-hand size of the existing timer inside the rbtree, i.e. behind the first expiring timer.
So its safe to allow enqueuing timers with the same expiry time as the first expiring timer on a remote CPU base.
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Cc: Christoph Hellwig <hch@lst.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: keescook@chromium.org Link: http://lkml.kernel.org/r/20171221104205.7269-22-anna-maria@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org> --- kernel/time/hrtimer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 1c68bf2..f4a56fb 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -168,7 +168,7 @@ hrtimer_check_target(struct hrtimer *timer, struct hrtimer_clock_base *new_base) ktime_t expires; expires = ktime_sub(hrtimer_get_expires(timer), new_base->offset); - return expires <= new_base->cpu_base->expires_next; + return expires < new_base->cpu_base->expires_next; } static inline
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