Commit 229836bd authored by Namhyung Kim's avatar Namhyung Kim Committed by Jens Axboe
Browse files

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: default avatarNamhyung Kim <namhyung@gmail.com>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
parent b9f8ce05

block/cfq-iosched.c

+5 −9
Original line number Diff line number Diff line
@@ -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);