From: Ralf Baechle <ralf@linux-mips.org>
To: linux-kernel@vger.kernel.org
Subject: RFC: Unneeded memory barriers
Date: Fri, 1 Dec 2006 14:11:30 +0000 [thread overview]
Message-ID: <20061201141130.GA24203@linux-mips.org> (raw)
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().
Ralf
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/kernel/futex.c b/kernel/futex.c
index 93ef30b..d867899 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -553,7 +553,7 @@ 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;
}
reply other threads:[~2006-12-01 14:11 UTC|newest]
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