cfq-iosched: Do not idle if slice_idle=0

Do not idle either on cfq queue or service tree if slice_idle=0. User does not want any queue or service tree idling. Currently even if slice_idle=0, we were waiting for request to finish before expiring the queue and that can lead to lower queue depths. Acked-by: Jeff Moyer <[email protected]> Signed-off-by: Vivek Goyal <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
mgowda · Aug 23, 2010 · b6508c1 · b6508c1
1 parent 75230ff
commit b6508c1
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
@@ -1839,6 +1839,9 @@ static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 	BUG_ON(!service_tree);
 	BUG_ON(!service_tree->count);
 
+	if (!cfqd->cfq_slice_idle)
+		return false;
+
 	/* We never do for idle class queues. */
 	if (prio == IDLE_WORKLOAD)
 		return false;
@@ -1879,7 +1882,7 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
 	/*
 	 * idle is disabled, either manually or by past process history
 	 */
-	if (!cfqd->cfq_slice_idle || !cfq_should_idle(cfqd, cfqq))
+	if (!cfq_should_idle(cfqd, cfqq))
 		return;
 
 	/*