diff options
| -rw-r--r-- | block/cfq-iosched.c | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index f92ba2a869b..bfb396774cb 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -867,15 +867,11 @@ static int cfq_arm_slice_timer(struct cfq_data *cfqd) static void cfq_dispatch_insert(request_queue_t *q, struct request *rq) { - struct cfq_data *cfqd = q->elevator->elevator_data; struct cfq_queue *cfqq = RQ_CFQQ(rq); cfq_remove_request(rq); cfqq->on_dispatch[rq_is_sync(rq)]++; elv_dispatch_sort(q, rq); - - rq = list_entry(q->queue_head.prev, struct request, queuelist); - cfqd->last_sector = rq->sector + rq->nr_sectors; } /* @@ -1585,6 +1581,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, struct request *rq) { struct cfq_queue *cfqq = cfqd->active_queue; + sector_t dist; if (cfq_class_idle(new_cfqq)) return 0; @@ -1594,14 +1591,14 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, if (cfq_class_idle(cfqq)) return 1; - if (!cfq_cfqq_wait_request(new_cfqq)) - return 0; + /* * if the new request is sync, but the currently running queue is * not, let the sync request have priority. */ if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) return 1; + /* * So both queues are sync. Let the new request get disk time if * it's a metadata request and the current queue is doing regular IO. @@ -1609,6 +1606,21 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, if (rq_is_meta(rq) && !cfqq->meta_pending) return 1; + if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) + return 0; + + /* + * if this request is as-good as one we would expect from the + * current cfqq, let it preempt + */ + if (rq->sector > cfqd->last_sector) + dist = rq->sector - cfqd->last_sector; + else + dist = cfqd->last_sector - rq->sector; + + if (dist <= cfqd->active_cic->seek_mean) + return 1; + return 0; } @@ -1719,6 +1731,8 @@ static void cfq_completed_request(request_queue_t *q, struct request *rq) cfqq->on_dispatch[sync]--; cfqq->service_last = now; + cfqd->last_sector = rq->hard_sector + rq->hard_nr_sectors; + if (!cfq_class_idle(cfqq)) cfqd->last_end_request = now; |