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-rw-r--r--block/cfq-iosched.c56
1 files changed, 36 insertions, 20 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 70b48ea0e3e9..fce8a749f4be 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -150,7 +150,7 @@ struct cfq_data {
* idle window management
*/
struct timer_list idle_slice_timer;
- struct work_struct unplug_work;
+ struct delayed_work unplug_work;
struct cfq_queue *active_queue;
struct cfq_io_context *active_cic;
@@ -268,11 +268,13 @@ static inline int cfq_bio_sync(struct bio *bio)
* scheduler run of queue, if there are requests pending and no one in the
* driver that will restart queueing
*/
-static inline void cfq_schedule_dispatch(struct cfq_data *cfqd)
+static inline void cfq_schedule_dispatch(struct cfq_data *cfqd,
+ unsigned long delay)
{
if (cfqd->busy_queues) {
cfq_log(cfqd, "schedule dispatch");
- kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work);
+ kblockd_schedule_delayed_work(cfqd->queue, &cfqd->unplug_work,
+ delay);
}
}
@@ -1316,8 +1318,6 @@ static int cfq_dispatch_requests(struct request_queue *q, int force)
* Does this cfqq already have too much IO in flight?
*/
if (cfqq->dispatched >= max_dispatch) {
- unsigned long load_at = cfqd->last_end_sync_rq + cfq_slice_sync;
-
/*
* idle queue must always only have a single IO in flight
*/
@@ -1331,20 +1331,36 @@ static int cfq_dispatch_requests(struct request_queue *q, int force)
return 0;
/*
- * If a sync request has completed recently, don't overload
- * the dispatch queue yet with async requests.
+ * Sole queue user, allow bigger slice
*/
- if (cfqd->cfq_desktop && !cfq_cfqq_sync(cfqq)
- && time_before(jiffies, load_at))
- return 0;
+ max_dispatch *= 4;
+ }
+
+ /*
+ * Async queues must wait a bit before being allowed dispatch.
+ * We also ramp up the dispatch depth gradually for async IO,
+ * based on the last sync IO we serviced
+ */
+ if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_desktop) {
+ unsigned long last_sync = jiffies - cfqd->last_end_sync_rq;
+ unsigned int depth;
/*
- * we are the only queue, allow up to 4 times of 'quantum'
+ * must wait a bit longer
*/
- if (cfqq->dispatched >= 4 * max_dispatch)
+ if (last_sync < cfq_slice_sync) {
+ cfq_schedule_dispatch(cfqd, cfq_slice_sync - last_sync);
return 0;
+ }
+
+ depth = last_sync / cfq_slice_sync;
+ if (depth < max_dispatch)
+ max_dispatch = depth;
}
+ if (cfqq->dispatched >= max_dispatch)
+ return 0;
+
/*
* Dispatch a request from this cfqq
*/
@@ -1389,7 +1405,7 @@ static void cfq_put_queue(struct cfq_queue *cfqq)
if (unlikely(cfqd->active_queue == cfqq)) {
__cfq_slice_expired(cfqd, cfqq, 0);
- cfq_schedule_dispatch(cfqd);
+ cfq_schedule_dispatch(cfqd, 0);
}
kmem_cache_free(cfq_pool, cfqq);
@@ -1484,7 +1500,7 @@ static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
if (unlikely(cfqq == cfqd->active_queue)) {
__cfq_slice_expired(cfqd, cfqq, 0);
- cfq_schedule_dispatch(cfqd);
+ cfq_schedule_dispatch(cfqd, 0);
}
cfq_put_queue(cfqq);
@@ -2201,7 +2217,7 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
}
if (!rq_in_driver(cfqd))
- cfq_schedule_dispatch(cfqd);
+ cfq_schedule_dispatch(cfqd, 0);
}
/*
@@ -2331,7 +2347,7 @@ queue_fail:
if (cic)
put_io_context(cic->ioc);
- cfq_schedule_dispatch(cfqd);
+ cfq_schedule_dispatch(cfqd, 0);
spin_unlock_irqrestore(q->queue_lock, flags);
cfq_log(cfqd, "set_request fail");
return 1;
@@ -2340,7 +2356,7 @@ queue_fail:
static void cfq_kick_queue(struct work_struct *work)
{
struct cfq_data *cfqd =
- container_of(work, struct cfq_data, unplug_work);
+ container_of(work, struct cfq_data, unplug_work.work);
struct request_queue *q = cfqd->queue;
spin_lock_irq(q->queue_lock);
@@ -2394,7 +2410,7 @@ static void cfq_idle_slice_timer(unsigned long data)
expire:
cfq_slice_expired(cfqd, timed_out);
out_kick:
- cfq_schedule_dispatch(cfqd);
+ cfq_schedule_dispatch(cfqd, 0);
out_cont:
spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
}
@@ -2402,7 +2418,7 @@ out_cont:
static void cfq_shutdown_timer_wq(struct cfq_data *cfqd)
{
del_timer_sync(&cfqd->idle_slice_timer);
- cancel_work_sync(&cfqd->unplug_work);
+ cancel_delayed_work_sync(&cfqd->unplug_work);
}
static void cfq_put_async_queues(struct cfq_data *cfqd)
@@ -2484,7 +2500,7 @@ 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_WORK(&cfqd->unplug_work, cfq_kick_queue);
+ INIT_DELAYED_WORK(&cfqd->unplug_work, cfq_kick_queue);
cfqd->cfq_quantum = cfq_quantum;
cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0];