From: Andrew Morton <akpm@osdl.org>

prepare_to_wait()/finish_wait() is a little faster that the old-style
functions (less cross-CPU traffic).

Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Zach Brown <zab@zabbo.net>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 fs/aio.c |   10 ++++------
 1 files changed, 4 insertions(+), 6 deletions(-)

diff -puN fs/aio.c~aio-use-prepare_to_wait fs/aio.c
--- a/fs/aio.c~aio-use-prepare_to_wait
+++ a/fs/aio.c
@@ -1112,7 +1112,7 @@ static int read_events(struct kioctx *ct
 {
 	long			start_jiffies = jiffies;
 	struct task_struct	*tsk = current;
-	DECLARE_WAITQUEUE(wait, tsk);
+	DEFINE_WAIT(wait);
 	int			ret;
 	int			i = 0;
 	struct io_event		ent;
@@ -1173,7 +1173,7 @@ retry:
 	while (likely(i < nr)) {
 		add_wait_queue_exclusive(&ctx->wait, &wait);
 		do {
-			set_task_state(tsk, TASK_INTERRUPTIBLE);
+			prepare_to_wait(&ctx->wait, &wait, TASK_INTERRUPTIBLE);
 			ret = aio_read_evt(ctx, &ent);
 			if (ret)
 				break;
@@ -1188,10 +1188,8 @@ retry:
 				break;
 			}
 			/*ret = aio_read_evt(ctx, &ent);*/
-		} while (1) ;
-
-		set_task_state(tsk, TASK_RUNNING);
-		remove_wait_queue(&ctx->wait, &wait);
+		} while (1);
+		finish_wait(&ctx->wait, &wait);
 
 		if (unlikely(ret <= 0))
 			break;
_