sched/completion: Remove unnecessary ->wait.lock serialization when reading completio...

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>

diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
index 607f852b4d04ab3b70379bf42528aa40e5f588c7..9d1fe32da232a098934d5a19e5dd3d71290bc6db 100644 (file)
--- 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);