[PATCH] cfq-iosched: commenting non-obvious initialization

From: Corrado Zoccolo
Date: Wed Dec 09 2009 - 14:40:16 EST


Added a comment to explain the initialization of last_delayed_sync.

Signed-off-by: Corrado Zoccolo <czoccolo@xxxxxxxxx>
---
block/cfq-iosched.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 98b15b9..69ecee7 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -3759,6 +3759,10 @@ static void *cfq_init_queue(struct request_queue *q)
cfqd->cfq_latency = 1;
cfqd->cfq_group_isolation = 0;
cfqd->hw_tag = -1;
+ /*
+ * we optimistically start assuming sync ops weren't delayed in last
+ * second, in order to have larger depth for async operations.
+ */
cfqd->last_delayed_sync = jiffies - HZ;
INIT_RCU_HEAD(&cfqd->rcu);
return cfqd;
--
1.6.2.5



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