From: Anna-Maria Gleixner Date: Sun, 22 Oct 2017 23:39:59 +0200 Subject: [PATCH 21/36] hrtimer: Make remote enqueue decision less restrictive Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.14/older/patches-4.14.1-rt3.tar.xz 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 Signed-off-by: Thomas Gleixner Signed-off-by: Sebastian Andrzej Siewior --- kernel/time/hrtimer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -168,7 +168,7 @@ hrtimer_check_target(struct hrtimer *tim 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