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>

1 files changed, 5 insertions, 9 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 00763e510228..7ffceddee420 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -667,15 +667,11 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2,
         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);