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-rw-r--r--block/cfq-iosched.c39
1 files changed, 36 insertions, 3 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index baef5fc7cff..e0aa4dad674 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -92,6 +92,8 @@ struct cfq_data {
struct cfq_queue *active_queue;
struct cfq_io_context *active_cic;
+ struct cfq_queue *async_cfqq[IOPRIO_BE_NR];
+
struct timer_list idle_class_timer;
sector_t last_position;
@@ -1351,8 +1353,8 @@ static void cfq_ioc_set_ioprio(struct io_context *ioc)
}
static struct cfq_queue *
-cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct task_struct *tsk,
- gfp_t gfp_mask)
+cfq_find_alloc_queue(struct cfq_data *cfqd, int is_sync,
+ struct task_struct *tsk, gfp_t gfp_mask)
{
struct cfq_queue *cfqq, *new_cfqq = NULL;
struct cfq_io_context *cic;
@@ -1405,12 +1407,35 @@ retry:
if (new_cfqq)
kmem_cache_free(cfq_pool, new_cfqq);
- atomic_inc(&cfqq->ref);
out:
WARN_ON((gfp_mask & __GFP_WAIT) && !cfqq);
return cfqq;
}
+static struct cfq_queue *
+cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct task_struct *tsk,
+ gfp_t gfp_mask)
+{
+ const int ioprio = task_ioprio(tsk);
+ struct cfq_queue *cfqq = NULL;
+
+ if (!is_sync)
+ cfqq = cfqd->async_cfqq[ioprio];
+ if (!cfqq)
+ cfqq = cfq_find_alloc_queue(cfqd, is_sync, tsk, gfp_mask);
+
+ /*
+ * pin the queue now that it's allocated, scheduler exit will prune it
+ */
+ if (!is_sync && !cfqd->async_cfqq[ioprio]) {
+ atomic_inc(&cfqq->ref);
+ cfqd->async_cfqq[ioprio] = cfqq;
+ }
+
+ atomic_inc(&cfqq->ref);
+ return cfqq;
+}
+
/*
* We drop cfq io contexts lazily, so we may find a dead one.
*/
@@ -2019,6 +2044,7 @@ static void cfq_exit_queue(elevator_t *e)
{
struct cfq_data *cfqd = e->elevator_data;
request_queue_t *q = cfqd->queue;
+ int i;
cfq_shutdown_timer_wq(cfqd);
@@ -2035,6 +2061,13 @@ static void cfq_exit_queue(elevator_t *e)
__cfq_exit_single_io_context(cfqd, cic);
}
+ /*
+ * Put the async queues
+ */
+ for (i = 0; i < IOPRIO_BE_NR; i++)
+ if (cfqd->async_cfqq[i])
+ cfq_put_queue(cfqd->async_cfqq[i]);
+
spin_unlock_irq(q->queue_lock);
cfq_shutdown_timer_wq(cfqd);