commit 229836bd63c5413a4f8eed93d610b432be141e9b
author Namhyung Kim <namhyung@gmail.com> Tue May 24 10:23:21 2011 +0200
committer Jens Axboe <jaxboe@fusionio.com> Tue May 24 10:23:21 2011 +0200
tree a55fa492dbcde4c8f179d58d07165bdff872c34e
parent b9f8ce059940064a732da49b5d6e618381dad956

cfq-iosched: reduce bit operations in cfq_choose_req()

Reduce the number of bit operations in cfq_choose_req() on average
(and worst) cases.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

block/cfq-iosched.c

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 00763e5..7ffcedd 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -667,15 +667,11 @@
 	if (rq2 == NULL)
 		return rq1;
 
-	if (rq_is_sync(rq1) && !rq_is_sync(rq2))
-		return rq1;
-	else if (rq_is_sync(rq2) && !rq_is_sync(rq1))
-		return rq2;
-	if ((rq1->cmd_flags & REQ_META) && !(rq2->cmd_flags & REQ_META))
-		return rq1;
-	else if ((rq2->cmd_flags & REQ_META) &&
-		 !(rq1->cmd_flags & REQ_META))
-		return rq2;
+	if (rq_is_sync(rq1) != rq_is_sync(rq2))
+		return rq_is_sync(rq1) ? rq1 : rq2;
+
+	if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_META)
+		return rq1->cmd_flags & REQ_META ? rq1 : rq2;
 
 	s1 = blk_rq_pos(rq1);
 	s2 = blk_rq_pos(rq2);