[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>

2 files changed, 5 insertions, 5 deletions

diff --git a/lib/rwsem-spinlock.c b/lib/rwsem-spinlock.c
index 21f0db2c9711..40ffde940a86 100644
--- a/lib/rwsem-spinlock.c
+++ b/lib/rwsem-spinlock.c
@@ -76,7 +76,7 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite)
                 list_del(&waiter->list);
                 tsk = waiter->task;
                 /* Don't touch waiter after ->task has been NULLed */
-                mb();
+                smp_mb();
                 waiter->task = NULL;
                 wake_up_process(tsk);
                 put_task_struct(tsk);
@@ -91,7 +91,7 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite)
 
                 list_del(&waiter->list);
                 tsk = waiter->task;
-                mb();
+                smp_mb();
                 waiter->task = NULL;
                 wake_up_process(tsk);
                 put_task_struct(tsk);
@@ -123,7 +123,7 @@ __rwsem_wake_one_writer(struct rw_semaphore *sem)
         list_del(&waiter->list);
 
         tsk = waiter->task;
-        mb();
+        smp_mb();
         waiter->task = NULL;
         wake_up_process(tsk);
         put_task_struct(tsk);
diff --git a/lib/rwsem.c b/lib/rwsem.c
index 7644089ec8fa..62fa4eba9ffe 100644
--- a/lib/rwsem.c
+++ b/lib/rwsem.c
@@ -74,7 +74,7 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
          */
         list_del(&waiter->list);
         tsk = waiter->task;
-        mb();
+        smp_mb();
         waiter->task = NULL;
         wake_up_process(tsk);
         put_task_struct(tsk);
@@ -117,7 +117,7 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
                 waiter = list_entry(next, struct rwsem_waiter, list);
                 next = waiter->list.next;
                 tsk = waiter->task;
-                mb();
+                smp_mb();
                 waiter->task = NULL;
                 wake_up_process(tsk);
                 put_task_struct(tsk);