cfq-iosched: Don't set active queue in preempt

Commit "Add unaccounted time to timeslice_used" changed the behavior of cfq_preempt_queue to set cfqq active. Vivek pointed out that other preemption rules might get involved, so we shouldn't manually set which queue is active. This cleans up the code to just clear the queue stats at preemption time. Signed-off-by: Justin TerAvest <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
liveeasily · Mar 22, 2011 · eda5e0c · eda5e0c
1 parent 1e9bb88
commit eda5e0c
Showing 1 changed file with 23 additions and 16 deletions.
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
@@ -1620,27 +1620,33 @@ static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 	cfq_blkiocg_update_idle_time_stats(&cfqq->cfqg->blkg);
 }
 
+static void cfq_clear_queue_stats(struct cfq_data *cfqd,
+				  struct cfq_queue *cfqq)
+{
+	cfq_blkiocg_update_avg_queue_size_stats(&cfqq->cfqg->blkg);
+	cfqq->slice_start = 0;
+	cfqq->dispatch_start = jiffies;
+	cfqq->allocated_slice = 0;
+	cfqq->slice_end = 0;
+	cfqq->slice_dispatch = 0;
+	cfqq->nr_sectors = 0;
+
+	cfq_clear_cfqq_wait_request(cfqq);
+	cfq_clear_cfqq_must_dispatch(cfqq);
+	cfq_clear_cfqq_must_alloc_slice(cfqq);
+	cfq_clear_cfqq_fifo_expire(cfqq);
+	cfq_mark_cfqq_slice_new(cfqq);
+
+	cfq_del_timer(cfqd, cfqq);
+}
+
 static void __cfq_set_active_queue(struct cfq_data *cfqd,
 				   struct cfq_queue *cfqq)
 {
 	if (cfqq) {
 		cfq_log_cfqq(cfqd, cfqq, "set_active wl_prio:%d wl_type:%d",
 				cfqd->serving_prio, cfqd->serving_type);
-		cfq_blkiocg_update_avg_queue_size_stats(&cfqq->cfqg->blkg);
-		cfqq->slice_start = 0;
-		cfqq->dispatch_start = jiffies;
-		cfqq->allocated_slice = 0;
-		cfqq->slice_end = 0;
-		cfqq->slice_dispatch = 0;
-		cfqq->nr_sectors = 0;
-
-		cfq_clear_cfqq_wait_request(cfqq);
-		cfq_clear_cfqq_must_dispatch(cfqq);
-		cfq_clear_cfqq_must_alloc_slice(cfqq);
-		cfq_clear_cfqq_fifo_expire(cfqq);
-		cfq_mark_cfqq_slice_new(cfqq);
-
-		cfq_del_timer(cfqd, cfqq);
+		cfq_clear_queue_stats(cfqd, cfqq);
 	}
 
 	cfqd->active_queue = cfqq;
@@ -3332,7 +3338,8 @@ static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 	BUG_ON(!cfq_cfqq_on_rr(cfqq));
 
 	cfq_service_tree_add(cfqd, cfqq, 1);
-	__cfq_set_active_queue(cfqd, cfqq);
+
+	cfq_clear_queue_stats(cfqd, cfqq);
 }
 
 /*