Commit 67060e37 authored by Jens Axboe's avatar Jens Axboe Committed by Jens Axboe

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: default avatarJens Axboe <jens.axboe@oracle.com>
parent 0c534e0a
......@@ -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);
......
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