From de30ec47302c101c7badc8fe687641fd75e596e7 Mon Sep 17 00:00:00 2001 From: Nicholas Mc Guire Date: Sat, 17 Jan 2015 05:05:34 +0100 Subject: [PATCH] sched/completion: Remove unnecessary ->wait.lock serialization when reading completion state Signed-off-by: Nicholas Mc Guire Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Link: http://lkml.kernel.org/r/1421467534-22834-1-git-send-email-der.herr@hofr.at Signed-off-by: Ingo Molnar --- kernel/sched/completion.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c index 607f852b4d04..9d1fe32da232 100644 --- a/kernel/sched/completion.c +++ b/kernel/sched/completion.c @@ -288,13 +288,6 @@ EXPORT_SYMBOL(try_wait_for_completion); */ bool completion_done(struct completion *x) { - unsigned long flags; - int ret = 1; - - spin_lock_irqsave(&x->wait.lock, flags); - if (!x->done) - ret = 0; - spin_unlock_irqrestore(&x->wait.lock, flags); - return ret; + return !!ACCESS_ONCE(x->done); } EXPORT_SYMBOL(completion_done); -- 2.34.1