Commit 04dc6e71 authored by Jeff Moyer's avatar Jeff Moyer Committed by Jens Axboe
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cfq-iosched: use the default seek distance when there aren't enough seek samples 



If the cfq io context doesn't have enough samples yet to provide a mean
seek distance, then use the default threshold we have for seeky IO instead
of defaulting to 0.

Signed-off-by: default avatarJeff Moyer <jmoyer@redhat.com>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent 4d00aa47

block/cfq-iosched.c

+6 −5
Original line number Diff line number Diff line
@@ -947,14 +947,18 @@ static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, 
		return cfqd->last_position - rq->sector;

}



#define CIC_SEEK_THR	8 * 1024

#define CIC_SEEKY(cic)	((cic)->seek_mean > CIC_SEEK_THR)



static inline int cfq_rq_close(struct cfq_data *cfqd, struct request *rq)

{

	struct cfq_io_context *cic = cfqd->active_cic;

	sector_t sdist = cic->seek_mean;



	if (!sample_valid(cic->seek_samples))

		return 0;

		sdist = CIC_SEEK_THR;



	return cfq_dist_from_last(cfqd, rq) <= cic->seek_mean;

	return cfq_dist_from_last(cfqd, rq) <= sdist;

}



static struct cfq_queue *cfqq_close(struct cfq_data *cfqd,
@@ -1039,9 +1043,6 @@ static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, 
	return cfqq;

}





#define CIC_SEEKY(cic) ((cic)->seek_mean > (8 * 1024))



static void cfq_arm_slice_timer(struct cfq_data *cfqd)

{

	struct cfq_queue *cfqq = cfqd->active_queue;