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: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 0eb4aff..7e13f04 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -947,14 +947,18 @@
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 @@
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;