[PATCH] futex: remove unneeded barrier

When disassembling a kernel I found around over 90 sync Instructions from
mb, rmb and wmb calls in the kernel and only few of those make any sense to
me.  So here's the first one - I think the wmb() in kernel/futex.c is not
needed on uniprocessors so should become an smb_wmb().

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/kernel/futex.c b/kernel/futex.c
index d60b7f7a8cc3bdadaf4e8aab599a425261259767..a8302a1620ea4c29b3f127a5f3c67c3ef4ca8341 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -552,7 +552,7 @@ static void wake_futex(struct futex_q *q)
         * at the end of wake_up_all() does not prevent this store from
         * moving.
         */
-       wmb();
+       smp_wmb();
        q->lock_ptr = NULL;
 }