cfq-iosched: don't schedule a dispatch for a non-idle queue

Vivek suggests we don't need schedule a dispatch when an idle queue
becomes nonidle. And he is right, cfq_should_preempt already covers
the logic.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 1 insertions, 18 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index ca4d19907243..f90519430be6 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -3523,25 +3523,8 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
                 }
         }
 
-        if (!cfqd->rq_in_driver) {
+        if (!cfqd->rq_in_driver)
                 cfq_schedule_dispatch(cfqd);
-                return;
-        }
-        /*
-         * A queue is idle at cfq_dispatch_requests(), but it gets noidle
-         * later. We schedule a dispatch if the queue has no requests,
-         * otherwise the disk is actually in idle till all requests
-         * are finished even cfq_arm_slice_timer doesn't make the queue idle
-         * */
-        cfqq = cfqd->active_queue;
-        if (!cfqq)
-                return;
-
-        if (RB_EMPTY_ROOT(&cfqq->sort_list) && !cfq_should_idle(cfqd, cfqq) &&
-            (!cfqd->cfq_group_idle || cfqq->cfqg->nr_cfqq > 1)) {
-                cfq_del_timer(cfqd, cfqq);
-                cfq_schedule_dispatch(cfqd);
-        }
 }
 
 /*