Commit cb887411 authored by Jens Axboe's avatar Jens Axboe Committed by Jens Axboe
Browse files

cfq-iosched: tweak the FIFO checking 



We currently check the FIFO once per slice. Optimize that a bit and
only do it as the first thing for a new slice, so we don't end up
doing a single request and then seek to the FIFO requests.

Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent 1792669c

block/cfq-iosched.c

+4 −3
Original line number Diff line number Diff line
@@ -885,16 +885,17 @@ static inline struct request *cfq_check_fifo(struct cfq_queue *cfqq) 


	if (cfq_cfqq_fifo_expire(cfqq))

		return NULL;



	cfq_mark_cfqq_fifo_expire(cfqq);



	if (list_empty(&cfqq->fifo))

		return NULL;



	fifo = cfq_cfqq_class_sync(cfqq);

	rq = rq_entry_fifo(cfqq->fifo.next);



	if (time_after(jiffies, rq->start_time + cfqd->cfq_fifo_expire[fifo])) {

		cfq_mark_cfqq_fifo_expire(cfqq);

	if (time_after(jiffies, rq->start_time + cfqd->cfq_fifo_expire[fifo]))

		return rq;

	}



	return NULL;

}