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 <jmoyer@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
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 @@
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 @@
/*
* 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;
/*