From 34c6bc2c919a55e5ad4e698510a2f35ee13ab900 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 3 Feb 2014 16:21:09 +0100 Subject: [PATCH] locking/mutexes: Add extra reschedule point Add in an extra reschedule in an attempt to avoid getting reschedule the moment we've acquired the lock. Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-zah5eyn9gu7qlgwh9r6n2anc@git.kernel.org Signed-off-by: Ingo Molnar --- kernel/locking/mutex.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index 2670b84067d6..02c61a9c8906 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -468,6 +468,13 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, } osq_unlock(&lock->osq); slowpath: + /* + * If we fell out of the spin path because of need_resched(), + * reschedule now, before we try-lock the mutex. This avoids getting + * scheduled out right after we obtained the mutex. + */ + if (need_resched()) + schedule_preempt_disabled(); #endif spin_lock_mutex(&lock->wait_lock, flags); -- 2.39.5