From 67060e37994444ee9c0bd2413c8baa6cc58e7adb Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 18 Apr 2007 20:13:32 +0200 Subject: cfq-iosched: sort IDLE queues into the rbtree Same treatment as the RT conversion, just put the sorted idle branch at the end of the tree. Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 67 +++++++++++++++++++++++++---------------------------- 1 file changed, 31 insertions(+), 36 deletions(-) (limited to 'block') diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 81c057eadfcc..6a6a5f7930d8 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -92,7 +92,6 @@ struct cfq_data { */ struct cfq_rb_root service_tree; struct list_head cur_rr; - struct list_head idle_rr; unsigned int busy_queues; /* @@ -467,25 +466,33 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, while (*p) { struct cfq_queue *__cfqq; + struct rb_node **n; parent = *p; __cfqq = rb_entry(parent, struct cfq_queue, rb_node); /* * sort RT queues first, we always want to give - * preference to them. after that, sort on the next - * service time. + * preference to them. IDLE queues goes to the back. + * after that, sort on the next service time. */ if (cfq_class_rt(cfqq) > cfq_class_rt(__cfqq)) - p = &(*p)->rb_left; + n = &(*p)->rb_left; else if (cfq_class_rt(cfqq) < cfq_class_rt(__cfqq)) - p = &(*p)->rb_right; + n = &(*p)->rb_right; + else if (cfq_class_idle(cfqq) < cfq_class_idle(__cfqq)) + n = &(*p)->rb_left; + else if (cfq_class_idle(cfqq) > cfq_class_idle(__cfqq)) + n = &(*p)->rb_right; else if (rb_key < __cfqq->rb_key) - p = &(*p)->rb_left; - else { - p = &(*p)->rb_right; + n = &(*p)->rb_left; + else + n = &(*p)->rb_right; + + if (n == &(*p)->rb_right) left = 0; - } + + p = n; } if (left) @@ -506,19 +513,7 @@ static void cfq_resort_rr_list(struct cfq_queue *cfqq, int preempted) if (!cfq_cfqq_on_rr(cfqq)) return; - list_del_init(&cfqq->cfq_list); - - if (cfq_class_idle(cfqq)) { - /* - * IDLE goes to the tail of the idle list - */ - list_add_tail(&cfqq->cfq_list, &cfqd->idle_rr); - } else { - /* - * RT and BE queues, sort into the rbtree - */ - cfq_service_tree_add(cfqd, cfqq); - } + cfq_service_tree_add(cfqd, cfqq); } /* @@ -797,20 +792,22 @@ static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) cfqq = list_entry_cfqq(cfqd->cur_rr.next); } else if (!RB_EMPTY_ROOT(&cfqd->service_tree.rb)) { struct rb_node *n = cfq_rb_first(&cfqd->service_tree); + unsigned long end; cfqq = rb_entry(n, struct cfq_queue, rb_node); - } else if (!list_empty(&cfqd->idle_rr)) { - /* - * if we have idle queues and no rt or be queues had pending - * requests, either allow immediate service if the grace period - * has passed or arm the idle grace timer - */ - unsigned long end = cfqd->last_end_request + CFQ_IDLE_GRACE; - - if (time_after_eq(jiffies, end)) - cfqq = list_entry_cfqq(cfqd->idle_rr.next); - else - mod_timer(&cfqd->idle_class_timer, end); + if (cfq_class_idle(cfqq)) { + /* + * if we have idle queues and no rt or be queues had + * pending requests, either allow immediate service if + * the grace period has passed or arm the idle grace + * timer + */ + end = cfqd->last_end_request + CFQ_IDLE_GRACE; + if (time_before(jiffies, end)) { + mod_timer(&cfqd->idle_class_timer, end); + cfqq = NULL; + } + } } return cfqq; @@ -1074,7 +1071,6 @@ static int cfq_forced_dispatch(struct cfq_data *cfqd) } dispatched += cfq_forced_dispatch_cfqqs(&cfqd->cur_rr); - dispatched += cfq_forced_dispatch_cfqqs(&cfqd->idle_rr); cfq_slice_expired(cfqd, 0, 0); @@ -2047,7 +2043,6 @@ static void *cfq_init_queue(request_queue_t *q) cfqd->service_tree = CFQ_RB_ROOT; INIT_LIST_HEAD(&cfqd->cur_rr); - INIT_LIST_HEAD(&cfqd->idle_rr); INIT_LIST_HEAD(&cfqd->cic_list); cfqd->cfq_hash = kmalloc_node(sizeof(struct hlist_head) * CFQ_QHASH_ENTRIES, GFP_KERNEL, q->node); -- cgit v1.2.3