Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 12e9fddd authored by Jens Axboe's avatar Jens Axboe
Browse files

[PATCH] cfq-iosched: Detect idle process issuing async request 



If we are anticipating a sync request from this process and we are
waiting for that and see an async request come in, expire that slice
and move on.

Signed-off-by: default avatarJens Axboe <axboe@suse.de>
parent e0de0206

block/cfq-iosched.c

+13 −3
Original line number Diff line number Diff line
@@ -1747,14 +1747,24 @@ cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, 


	cfqq->next_crq = cfq_choose_req(cfqd, cfqq->next_crq, crq);



	cic = crq->io_context;



	/*

	 * we never wait for an async request and we don't allow preemption

	 * of an async request. so just return early

	 */

	if (!cfq_crq_is_sync(crq))

	if (!cfq_crq_is_sync(crq)) {

		/*

		 * sync process issued an async request, if it's waiting

		 * then expire it and kick rq handling.

		 */

		if (cic == cfqd->active_cic &&

		    del_timer(&cfqd->idle_slice_timer)) {

			cfq_slice_expired(cfqd, 0);

			cfq_start_queueing(cfqd, cfqq);

		}

		return;



	cic = crq->io_context;

	}



	cfq_update_io_thinktime(cfqd, cic);

	cfq_update_io_seektime(cfqd, cic, crq);