diff options
Diffstat (limited to 'block/cfq-iosched.c')
| -rw-r--r-- | block/cfq-iosched.c | 41 |
1 files changed, 30 insertions, 11 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index ef631539dd2..c826ef81c67 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -237,6 +237,7 @@ struct cfq_data { struct rb_root prio_trees[CFQ_PRIO_LISTS]; unsigned int busy_queues; + unsigned int busy_sync_queues; int rq_in_driver; int rq_in_flight[2]; @@ -549,15 +550,13 @@ static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime) static void update_min_vdisktime(struct cfq_rb_root *st) { - u64 vdisktime = st->min_vdisktime; struct cfq_group *cfqg; if (st->left) { cfqg = rb_entry_cfqg(st->left); - vdisktime = min_vdisktime(vdisktime, cfqg->vdisktime); + st->min_vdisktime = max_vdisktime(st->min_vdisktime, + cfqg->vdisktime); } - - st->min_vdisktime = max_vdisktime(st->min_vdisktime, vdisktime); } /* @@ -1337,6 +1336,8 @@ static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) BUG_ON(cfq_cfqq_on_rr(cfqq)); cfq_mark_cfqq_on_rr(cfqq); cfqd->busy_queues++; + if (cfq_cfqq_sync(cfqq)) + cfqd->busy_sync_queues++; cfq_resort_rr_list(cfqd, cfqq); } @@ -1363,6 +1364,8 @@ static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) cfq_group_service_tree_del(cfqd, cfqq->cfqg); BUG_ON(!cfqd->busy_queues); cfqd->busy_queues--; + if (cfq_cfqq_sync(cfqq)) + cfqd->busy_sync_queues--; } /* @@ -2370,6 +2373,7 @@ static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) * Does this cfqq already have too much IO in flight? */ if (cfqq->dispatched >= max_dispatch) { + bool promote_sync = false; /* * idle queue must always only have a single IO in flight */ @@ -2377,15 +2381,31 @@ static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) return false; /* + * If there is only one sync queue, and its think time is + * small, we can ignore async queue here and give the sync + * queue no dispatch limit. The reason is a sync queue can + * preempt async queue, limiting the sync queue doesn't make + * sense. This is useful for aiostress test. + */ + if (cfq_cfqq_sync(cfqq) && cfqd->busy_sync_queues == 1) { + struct cfq_io_context *cic = RQ_CIC(cfqq->next_rq); + + if (sample_valid(cic->ttime_samples) && + cic->ttime_mean < cfqd->cfq_slice_idle) + promote_sync = true; + } + + /* * We have other queues, don't allow more IO from this one */ - if (cfqd->busy_queues > 1 && cfq_slice_used_soon(cfqd, cfqq)) + if (cfqd->busy_queues > 1 && cfq_slice_used_soon(cfqd, cfqq) && + !promote_sync) return false; /* * Sole queue user, no limit */ - if (cfqd->busy_queues == 1) + if (cfqd->busy_queues == 1 || promote_sync) max_dispatch = -1; else /* @@ -3317,7 +3337,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, cfqd->busy_queues > 1) { cfq_del_timer(cfqd, cfqq); cfq_clear_cfqq_wait_request(cfqq); - __blk_run_queue(cfqd->queue); + __blk_run_queue(cfqd->queue, false); } else { cfq_blkiocg_update_idle_time_stats( &cfqq->cfqg->blkg); @@ -3332,7 +3352,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, * this new queue is RT and the current one is BE */ cfq_preempt_queue(cfqd, cfqq); - __blk_run_queue(cfqd->queue); + __blk_run_queue(cfqd->queue, false); } } @@ -3668,12 +3688,11 @@ new_queue: cfqq->allocated[rw]++; - spin_unlock_irqrestore(q->queue_lock, flags); - cfqq->ref++; rq->elevator_private[0] = cic; rq->elevator_private[1] = cfqq; rq->elevator_private[2] = cfq_ref_get_cfqg(cfqq->cfqg); + spin_unlock_irqrestore(q->queue_lock, flags); return 0; queue_fail: @@ -3693,7 +3712,7 @@ static void cfq_kick_queue(struct work_struct *work) struct request_queue *q = cfqd->queue; spin_lock_irq(q->queue_lock); - __blk_run_queue(cfqd->queue); + __blk_run_queue(cfqd->queue, false); spin_unlock_irq(q->queue_lock); } |