[PATCH 1/5] cfq-iosched: Do not idle if slice_idle=0

[Vivek Goyal <vgoyal@redhat.com>]

o 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.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
 block/cfq-iosched.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index eb4086f..8830569 100644
--- 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;
 
 	/*
-- 
1.7.1.1