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-rw-r--r--block/cfq-iosched.c31
1 files changed, 18 insertions, 13 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index df82755ac40..a8237be97a2 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -96,6 +96,7 @@ struct cfq_data {
struct hlist_head *cfq_hash;
int rq_in_driver;
+ int sync_flight;
int hw_tag;
/*
@@ -911,11 +912,15 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
*/
static void cfq_dispatch_insert(request_queue_t *q, struct request *rq)
{
+ struct cfq_data *cfqd = q->elevator->elevator_data;
struct cfq_queue *cfqq = RQ_CFQQ(rq);
cfq_remove_request(rq);
cfqq->dispatched++;
elv_dispatch_sort(q, rq);
+
+ if (cfq_cfqq_sync(cfqq))
+ cfqd->sync_flight++;
}
/*
@@ -1100,27 +1105,24 @@ static int cfq_dispatch_requests(request_queue_t *q, int force)
while ((cfqq = cfq_select_queue(cfqd)) != NULL) {
int max_dispatch;
- if (cfqd->busy_queues > 1) {
- /*
- * So we have dispatched before in this round, if the
- * next queue has idling enabled (must be sync), don't
- * allow it service until the previous have completed.
- */
- if (cfqd->rq_in_driver && cfq_cfqq_idle_window(cfqq) &&
- dispatched)
+ max_dispatch = cfqd->cfq_quantum;
+ if (cfq_class_idle(cfqq))
+ max_dispatch = 1;
+
+ if (cfqq->dispatched >= max_dispatch) {
+ if (cfqd->busy_queues > 1)
break;
- if (cfqq->dispatched >= cfqd->cfq_quantum)
+ if (cfqq->dispatched >= 4 * max_dispatch)
break;
}
+ if (cfqd->sync_flight && !cfq_cfqq_sync(cfqq))
+ break;
+
cfq_clear_cfqq_must_dispatch(cfqq);
cfq_clear_cfqq_wait_request(cfqq);
del_timer(&cfqd->idle_slice_timer);
- max_dispatch = cfqd->cfq_quantum;
- if (cfq_class_idle(cfqq))
- max_dispatch = 1;
-
dispatched += __cfq_dispatch_requests(cfqd, cfqq, max_dispatch);
}
@@ -1767,6 +1769,9 @@ static void cfq_completed_request(request_queue_t *q, struct request *rq)
cfqd->rq_in_driver--;
cfqq->dispatched--;
+ if (cfq_cfqq_sync(cfqq))
+ cfqd->sync_flight--;
+
if (!cfq_class_idle(cfqq))
cfqd->last_end_request = now;