summaryrefslogtreecommitdiff
path: root/block/cfq-iosched.c
diff options
context:
space:
mode:
Diffstat (limited to 'block/cfq-iosched.c')
-rw-r--r--block/cfq-iosched.c117
1 files changed, 34 insertions, 83 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 8830893e062f..8fe1a0ddb511 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -26,9 +26,9 @@ static const int cfq_slice_async_rq = 2;
static int cfq_slice_idle = HZ / 125;
/*
- * grace period before allowing idle class to get disk access
+ * offset from end of service tree
*/
-#define CFQ_IDLE_GRACE (HZ / 10)
+#define CFQ_IDLE_DELAY (HZ / 5)
/*
* below this threshold, we consider thinktime immediate
@@ -98,8 +98,6 @@ struct cfq_data {
struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR];
struct cfq_queue *async_idle_cfqq;
- struct timer_list idle_class_timer;
-
sector_t last_position;
unsigned long last_end_request;
@@ -384,12 +382,15 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2)
/*
* The below is leftmost cache rbtree addon
*/
-static struct rb_node *cfq_rb_first(struct cfq_rb_root *root)
+static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root)
{
if (!root->left)
root->left = rb_first(&root->rb);
- return root->left;
+ if (root->left)
+ return rb_entry(root->left, struct cfq_queue, rb_node);
+
+ return NULL;
}
static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root)
@@ -446,12 +447,20 @@ static unsigned long cfq_slice_offset(struct cfq_data *cfqd,
static void cfq_service_tree_add(struct cfq_data *cfqd,
struct cfq_queue *cfqq, int add_front)
{
- struct rb_node **p = &cfqd->service_tree.rb.rb_node;
- struct rb_node *parent = NULL;
+ struct rb_node **p, *parent;
+ struct cfq_queue *__cfqq;
unsigned long rb_key;
int left;
- if (!add_front) {
+ if (cfq_class_idle(cfqq)) {
+ rb_key = CFQ_IDLE_DELAY;
+ parent = rb_last(&cfqd->service_tree.rb);
+ if (parent && parent != &cfqq->rb_node) {
+ __cfqq = rb_entry(parent, struct cfq_queue, rb_node);
+ rb_key += __cfqq->rb_key;
+ } else
+ rb_key += jiffies;
+ } else if (!add_front) {
rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies;
rb_key += cfqq->slice_resid;
cfqq->slice_resid = 0;
@@ -469,8 +478,9 @@ static void cfq_service_tree_add(struct cfq_data *cfqd,
}
left = 1;
+ parent = NULL;
+ p = &cfqd->service_tree.rb.rb_node;
while (*p) {
- struct cfq_queue *__cfqq;
struct rb_node **n;
parent = *p;
@@ -736,11 +746,6 @@ static inline void
__cfq_set_active_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
if (cfqq) {
- /*
- * stop potential idle class queues waiting service
- */
- del_timer(&cfqd->idle_class_timer);
-
cfqq->slice_end = 0;
cfq_clear_cfqq_must_alloc_slice(cfqq);
cfq_clear_cfqq_fifo_expire(cfqq);
@@ -789,47 +794,16 @@ static inline void cfq_slice_expired(struct cfq_data *cfqd, int timed_out)
__cfq_slice_expired(cfqd, cfqq, timed_out);
}
-static int start_idle_class_timer(struct cfq_data *cfqd)
-{
- unsigned long end = cfqd->last_end_request + CFQ_IDLE_GRACE;
- unsigned long now = jiffies;
-
- if (time_before(now, end) &&
- time_after_eq(now, cfqd->last_end_request)) {
- mod_timer(&cfqd->idle_class_timer, end);
- return 1;
- }
-
- return 0;
-}
-
/*
* Get next queue for service. Unless we have a queue preemption,
* we'll simply select the first cfqq in the service tree.
*/
static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd)
{
- struct cfq_queue *cfqq;
- struct rb_node *n;
-
if (RB_EMPTY_ROOT(&cfqd->service_tree.rb))
return NULL;
- n = cfq_rb_first(&cfqd->service_tree);
- cfqq = rb_entry(n, struct cfq_queue, rb_node);
-
- 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
- */
- if (start_idle_class_timer(cfqd))
- cfqq = NULL;
- }
-
- return cfqq;
+ return cfq_rb_first(&cfqd->service_tree);
}
/*
@@ -1087,14 +1061,11 @@ static inline int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq)
*/
static int cfq_forced_dispatch(struct cfq_data *cfqd)
{
+ struct cfq_queue *cfqq;
int dispatched = 0;
- struct rb_node *n;
-
- while ((n = cfq_rb_first(&cfqd->service_tree)) != NULL) {
- struct cfq_queue *cfqq = rb_entry(n, struct cfq_queue, rb_node);
+ while ((cfqq = cfq_rb_first(&cfqd->service_tree)) != NULL)
dispatched += __cfq_forced_dispatch_cfqq(cfqq);
- }
cfq_slice_expired(cfqd, 0);
@@ -1437,15 +1408,16 @@ retry:
atomic_set(&cfqq->ref, 0);
cfqq->cfqd = cfqd;
- if (is_sync) {
- cfq_mark_cfqq_idle_window(cfqq);
- cfq_mark_cfqq_sync(cfqq);
- }
-
cfq_mark_cfqq_prio_changed(cfqq);
cfq_mark_cfqq_queue_new(cfqq);
cfq_init_prio_data(cfqq, ioc);
+
+ if (is_sync) {
+ if (!cfq_class_idle(cfqq))
+ cfq_mark_cfqq_idle_window(cfqq);
+ cfq_mark_cfqq_sync(cfqq);
+ }
}
if (new_cfqq)
@@ -1697,7 +1669,10 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq,
{
int enable_idle;
- if (!cfq_cfqq_sync(cfqq))
+ /*
+ * Don't idle for async or idle io prio class
+ */
+ if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq))
return;
enable_idle = cfq_cfqq_idle_window(cfqq);
@@ -1876,7 +1851,7 @@ 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 (cfq_slice_used(cfqq))
+ if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq))
cfq_slice_expired(cfqd, 1);
else if (sync && RB_EMPTY_ROOT(&cfqq->sort_list))
cfq_arm_slice_timer(cfqd);
@@ -2080,29 +2055,9 @@ out_cont:
spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
}
-/*
- * Timer running if an idle class queue is waiting for service
- */
-static void cfq_idle_class_timer(unsigned long data)
-{
- struct cfq_data *cfqd = (struct cfq_data *) data;
- unsigned long flags;
-
- spin_lock_irqsave(cfqd->queue->queue_lock, flags);
-
- /*
- * race with a non-idle queue, reset timer
- */
- if (!start_idle_class_timer(cfqd))
- cfq_schedule_dispatch(cfqd);
-
- spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
-}
-
static void cfq_shutdown_timer_wq(struct cfq_data *cfqd)
{
del_timer_sync(&cfqd->idle_slice_timer);
- del_timer_sync(&cfqd->idle_class_timer);
kblockd_flush_work(&cfqd->unplug_work);
}
@@ -2167,10 +2122,6 @@ static void *cfq_init_queue(struct request_queue *q)
cfqd->idle_slice_timer.function = cfq_idle_slice_timer;
cfqd->idle_slice_timer.data = (unsigned long) cfqd;
- init_timer(&cfqd->idle_class_timer);
- cfqd->idle_class_timer.function = cfq_idle_class_timer;
- cfqd->idle_class_timer.data = (unsigned long) cfqd;
-
INIT_WORK(&cfqd->unplug_work, cfq_kick_queue);
cfqd->last_end_request = jiffies;
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-18 02:57:53 +0000