From de30ec47302c101c7badc8fe687641fd75e596e7 Mon Sep 17 00:00:00 2001
From: Nicholas Mc Guire <der.herr@hofr.at>
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 <der.herr@hofr.at>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1421467534-22834-1-git-send-email-der.herr@hofr.at
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
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