From 39c01b219fd30c74869b6fc8749f7900f04e9ef6 Mon Sep 17 00:00:00 2001 From: Divyesh Shah Date: Thu, 25 Mar 2010 15:45:57 +0100 Subject: [PATCH] cfq-iosched: Do not merge queues of BE and IDLE classes Even if they are found to be co-operating. The prio_trees do not have any IDLE cfqqs on them. cfq_close_cooperator() is called from cfq_select_queue() and cfq_completed_request(). The latter ensures that the close cooperator code does not get invoked if the current cfqq is of class IDLE but the former doesn't seem to have any such checks. So an IDLE cfqq may get merged with a BE cfqq from the same group which should be avoided. Signed-off-by: Divyesh Shah Acked-by: Vivek Goyal Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 2f91c5351949..2c7a0f4f3cd7 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1723,6 +1723,8 @@ static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, { struct cfq_queue *cfqq; + if (cfq_class_idle(cur_cfqq)) + return NULL; if (!cfq_cfqq_sync(cur_cfqq)) return NULL; if (CFQQ_SEEKY(cur_cfqq)) -- GitLab