diff options
| -rw-r--r-- | block/cfq-iosched.c | 53 |
1 files changed, 22 insertions, 31 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 0452108a932e..c6e649f3cae7 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -152,7 +152,6 @@ struct cfq_queue { unsigned long slice_start; unsigned long slice_end; unsigned long slice_left; - unsigned long service_last; /* number of requests that are on the dispatch list */ int on_dispatch[2]; @@ -174,6 +173,7 @@ enum cfqq_state_flags { CFQ_CFQQ_FLAG_fifo_expire, CFQ_CFQQ_FLAG_idle_window, CFQ_CFQQ_FLAG_prio_changed, + CFQ_CFQQ_FLAG_queue_new, }; #define CFQ_CFQQ_FNS(name) \ @@ -198,6 +198,7 @@ CFQ_CFQQ_FNS(must_dispatch); CFQ_CFQQ_FNS(fifo_expire); CFQ_CFQQ_FNS(idle_window); CFQ_CFQQ_FNS(prio_changed); +CFQ_CFQQ_FNS(queue_new); #undef CFQ_CFQQ_FNS static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *, unsigned int, unsigned short); @@ -350,7 +351,7 @@ cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, static void cfq_resort_rr_list(struct cfq_queue *cfqq, int preempted) { struct cfq_data *cfqd = cfqq->cfqd; - struct list_head *list, *entry; + struct list_head *list; BUG_ON(!cfq_cfqq_on_rr(cfqq)); @@ -375,31 +376,26 @@ static void cfq_resort_rr_list(struct cfq_queue *cfqq, int preempted) } /* - * if queue was preempted, just add to front to be fair. busy_rr - * isn't sorted, but insert at the back for fairness. + * If this queue was preempted or is new (never been serviced), let + * it be added first for fairness but beind other new queues. + * Otherwise, just add to the back of the list. */ - if (preempted || list == &cfqd->busy_rr) { - if (preempted) - list = list->prev; + if (preempted || cfq_cfqq_queue_new(cfqq)) { + struct list_head *n = list; + struct cfq_queue *__cfqq; - list_add_tail(&cfqq->cfq_list, list); - return; - } + while (n->next != list) { + __cfqq = list_entry_cfqq(n->next); + if (!cfq_cfqq_queue_new(__cfqq)) + break; - /* - * sort by when queue was last serviced - */ - entry = list; - while ((entry = entry->prev) != list) { - struct cfq_queue *__cfqq = list_entry_cfqq(entry); + n = n->next; + } - if (!__cfqq->service_last) - break; - if (time_before(__cfqq->service_last, cfqq->service_last)) - break; + list = n; } - list_add(&cfqq->cfq_list, entry); + list_add_tail(&cfqq->cfq_list, list); } /* @@ -591,13 +587,12 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, if (cfq_cfqq_wait_request(cfqq)) del_timer(&cfqd->idle_slice_timer); - if (!preempted && !cfq_cfqq_dispatched(cfqq)) { - cfqq->service_last = now; + if (!preempted && !cfq_cfqq_dispatched(cfqq)) cfq_schedule_dispatch(cfqd); - } cfq_clear_cfqq_must_dispatch(cfqq); cfq_clear_cfqq_wait_request(cfqq); + cfq_clear_cfqq_queue_new(cfqq); /* * store what was left of this slice, if the queue idled out @@ -1297,13 +1292,13 @@ retry: hlist_add_head(&cfqq->cfq_hash, &cfqd->cfq_hash[hashval]); atomic_set(&cfqq->ref, 0); cfqq->cfqd = cfqd; - cfqq->service_last = 0; /* * set ->slice_left to allow preemption for a new process */ cfqq->slice_left = 2 * cfqd->cfq_slice_idle; cfq_mark_cfqq_idle_window(cfqq); cfq_mark_cfqq_prio_changed(cfqq); + cfq_mark_cfqq_queue_new(cfqq); cfq_init_prio_data(cfqq); } @@ -1672,12 +1667,8 @@ static void cfq_completed_request(request_queue_t *q, struct request *rq) if (!cfq_class_idle(cfqq)) cfqd->last_end_request = now; - if (!cfq_cfqq_dispatched(cfqq)) { - if (cfq_cfqq_on_rr(cfqq)) { - cfqq->service_last = now; - cfq_resort_rr_list(cfqq, 0); - } - } + if (!cfq_cfqq_dispatched(cfqq) && cfq_cfqq_on_rr(cfqq)) + cfq_resort_rr_list(cfqq, 0); if (sync) RQ_CIC(rq)->last_end_request = now; |