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authorNamhyung Kim <namhyung@gmail.com>2011-05-24 10:23:21 +0200
committerJens Axboe <jaxboe@fusionio.com>2011-05-24 10:23:21 +0200
commit229836bd63c5413a4f8eed93d610b432be141e9b (patch)
treea55fa492dbcde4c8f179d58d07165bdff872c34e
parentb9f8ce059940064a732da49b5d6e618381dad956 (diff)
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>
-rw-r--r--block/cfq-iosched.c14
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);