Commit 2b9408a4 authored by Shaohua Li's avatar Shaohua Li Committed by Jens Axboe
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cfq-iosched: don't schedule a dispatch for a non-idle queue 



Vivek suggests we don't need schedule a dispatch when an idle queue
becomes nonidle. And he is right, cfq_should_preempt already covers
the logic.

Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
parent 8e1ac665

block/cfq-iosched.c

+1 −18
Original line number Diff line number Diff line
@@ -3523,25 +3523,8 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq) 
		}

	}



	if (!cfqd->rq_in_driver) {

	if (!cfqd->rq_in_driver)

		cfq_schedule_dispatch(cfqd);

		return;

	}

	/*

	 * A queue is idle at cfq_dispatch_requests(), but it gets noidle

	 * later. We schedule a dispatch if the queue has no requests,

	 * otherwise the disk is actually in idle till all requests

	 * are finished even cfq_arm_slice_timer doesn't make the queue idle

	 * */

	cfqq = cfqd->active_queue;

	if (!cfqq)

		return;



	if (RB_EMPTY_ROOT(&cfqq->sort_list) && !cfq_should_idle(cfqd, cfqq) &&

	    (!cfqd->cfq_group_idle || cfqq->cfqg->nr_cfqq > 1)) {

		cfq_del_timer(cfqd, cfqq);

		cfq_schedule_dispatch(cfqd);

	}

}



/*