diff options
| -rw-r--r-- | block/cfq-iosched.c | 34 |
1 files changed, 29 insertions, 5 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index f7364621613a..1cc10489eaf0 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -117,6 +117,7 @@ struct cfq_queue { /* time when queue got scheduled in to dispatch first request. */ unsigned long dispatch_start; + unsigned int allocated_slice; /* time when first request from queue completed and slice started. */ unsigned long slice_start; unsigned long slice_end; @@ -314,6 +315,8 @@ enum cfqq_state_flags { CFQ_CFQQ_FLAG_sync, /* synchronous queue */ CFQ_CFQQ_FLAG_coop, /* cfqq is shared */ CFQ_CFQQ_FLAG_deep, /* sync cfqq experienced large depth */ + CFQ_CFQQ_FLAG_wait_busy, /* Waiting for next request */ + CFQ_CFQQ_FLAG_wait_busy_done, /* Got new request. Expire the queue */ }; #define CFQ_CFQQ_FNS(name) \ @@ -341,6 +344,8 @@ CFQ_CFQQ_FNS(slice_new); CFQ_CFQQ_FNS(sync); CFQ_CFQQ_FNS(coop); CFQ_CFQQ_FNS(deep); +CFQ_CFQQ_FNS(wait_busy); +CFQ_CFQQ_FNS(wait_busy_done); #undef CFQ_CFQQ_FNS #ifdef CONFIG_DEBUG_CFQ_IOSCHED @@ -578,6 +583,7 @@ cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) } cfqq->slice_start = jiffies; cfqq->slice_end = jiffies + slice; + cfqq->allocated_slice = slice; cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); } @@ -859,7 +865,7 @@ cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg) static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq) { - unsigned int slice_used, allocated_slice; + unsigned int slice_used; /* * Queue got expired before even a single request completed or @@ -876,9 +882,8 @@ static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq) 1); } else { slice_used = jiffies - cfqq->slice_start; - allocated_slice = cfqq->slice_end - cfqq->slice_start; - if (slice_used > allocated_slice) - slice_used = allocated_slice; + if (slice_used > cfqq->allocated_slice) + slice_used = cfqq->allocated_slice; } cfq_log_cfqq(cfqq->cfqd, cfqq, "sl_used=%u sect=%lu", slice_used, @@ -1495,6 +1500,7 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd, cfq_log_cfqq(cfqd, cfqq, "set_active"); cfqq->slice_start = 0; cfqq->dispatch_start = jiffies; + cfqq->allocated_slice = 0; cfqq->slice_end = 0; cfqq->slice_dispatch = 0; cfqq->nr_sectors = 0; @@ -1524,6 +1530,8 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, del_timer(&cfqd->idle_slice_timer); cfq_clear_cfqq_wait_request(cfqq); + cfq_clear_cfqq_wait_busy(cfqq); + cfq_clear_cfqq_wait_busy_done(cfqq); /* * store what was left of this slice, if the queue idled/timed out @@ -2066,7 +2074,8 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) /* * The active queue has run out of time, expire it and select new. */ - if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) + if ((cfq_slice_used(cfqq) || cfq_cfqq_wait_busy_done(cfqq)) + && !cfq_cfqq_must_dispatch(cfqq)) goto expire; /* @@ -3096,6 +3105,10 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, cfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq); if (cfqq == cfqd->active_queue) { + if (cfq_cfqq_wait_busy(cfqq)) { + cfq_clear_cfqq_wait_busy(cfqq); + cfq_mark_cfqq_wait_busy_done(cfqq); + } /* * Remember that we saw a request from this process, but * don't start queuing just yet. Otherwise we risk seeing lots @@ -3214,6 +3227,17 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq) cfq_set_prio_slice(cfqd, cfqq); cfq_clear_cfqq_slice_new(cfqq); } + + /* + * If this queue consumed its slice and this is last queue + * in the group, wait for next request before we expire + * the queue + */ + if (cfq_slice_used(cfqq) && cfqq->cfqg->nr_cfqq == 1) { + cfqq->slice_end = jiffies + cfqd->cfq_slice_idle; + cfq_mark_cfqq_wait_busy(cfqq); + } + /* * Idling is not enabled on: * - expired queues |