[PATCH] use smp_mb/wmb/rmb where possible
Replace a number of memory barriers with smp_ variants. This means we won't
take the unnecessary hit on UP machines.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/buffer.c b/fs/buffer.c
index 665db84..188365c 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -218,7 +218,7 @@
sb = get_super(bdev);
if (sb && !(sb->s_flags & MS_RDONLY)) {
sb->s_frozen = SB_FREEZE_WRITE;
- wmb();
+ smp_wmb();
sync_inodes_sb(sb, 0);
DQUOT_SYNC(sb);
@@ -235,7 +235,7 @@
sync_inodes_sb(sb, 1);
sb->s_frozen = SB_FREEZE_TRANS;
- wmb();
+ smp_wmb();
sync_blockdev(sb->s_bdev);
@@ -263,7 +263,7 @@
if (sb->s_op->unlockfs)
sb->s_op->unlockfs(sb);
sb->s_frozen = SB_UNFROZEN;
- wmb();
+ smp_wmb();
wake_up(&sb->s_wait_unfrozen);
drop_super(sb);
}
