Commit b9d8f4c7 authored by Gui Jianfeng's avatar Gui Jianfeng Committed by Jens Axboe
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cfq: Optimization for close cooperating queue searching 



It doesn't make any sense to try to find out a close cooperating
queue if current cfqq is the only one in the group.

Signed-off-by: default avatarGui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent a3b8d92d

block/cfq-iosched.c

+6 −0
Original line number Diff line number Diff line
@@ -1749,6 +1749,12 @@ static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, 
	if (CFQQ_SEEKY(cur_cfqq))

		return NULL;



	/*

	 * Don't search priority tree if it's the only queue in the group.

	 */

	if (cur_cfqq->cfqg->nr_cfqq == 1)

		return NULL;



	/*

	 * We should notice if some of the queues are cooperating, eg

	 * working closely on the same area of the disk. In that case,