cfq-iosched: don't regard requests with long distance as close (2f7a2d89) · Commits · 戴 / test

block/cfq-iosched.c

+8 −4

Original line number	Diff line number	Diff line
		@@ -1667,13 +1667,17 @@ static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd,
		#define CFQQ_SEEKY(cfqq) ((cfqq)->seek_mean > CFQQ_SEEK_THR)

		static inline int cfq_rq_close(struct cfq_data cfqd, struct cfq_queue cfqq,
		struct request *rq)
		struct request *rq, bool for_preempt)
		{
		sector_t sdist = cfqq->seek_mean;

		if (!sample_valid(cfqq->seek_samples))
		sdist = CFQQ_SEEK_THR;

		/* if seek_mean is big, using it as close criteria is meaningless */
		if (sdist > CFQQ_SEEK_THR && !for_preempt)
		sdist = CFQQ_SEEK_THR;

		return cfq_dist_from_last(cfqd, rq) <= sdist;
		}

		@@ -1701,7 +1705,7 @@ static struct cfq_queue cfqq_close(struct cfq_data cfqd,
		* will contain the closest sector.
		*/
		__cfqq = rb_entry(parent, struct cfq_queue, p_node);
		if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq))
		if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq, false))
		return __cfqq;

		if (blk_rq_pos(__cfqq->next_rq) < sector)
		@@ -1712,7 +1716,7 @@ static struct cfq_queue cfqq_close(struct cfq_data cfqd,
		return NULL;

		__cfqq = rb_entry(node, struct cfq_queue, p_node);
		if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq))
		if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq, false))
		return __cfqq;

		return NULL;
		@@ -3112,7 +3116,7 @@ cfq_should_preempt(struct cfq_data cfqd, struct cfq_queue new_cfqq,
		* if this request is as-good as one we would expect from the
		* current cfqq, let it preempt
		*/
		if (cfq_rq_close(cfqd, cfqq, rq))
		if (cfq_rq_close(cfqd, cfqq, rq, true))
		return true;

		return false;