From: Oleg Nesterov <oleg@tv-sign.ru>
Date: Mon, 5 Nov 2007 07:58:05 +0000 (+0100)
Subject: cfq: fix IOPRIO_CLASS_IDLE accounting
X-Git-Tag: v2.6.24-rc3~174^2~7
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2389d1ef172fc9df01f58265a436919d233fbc27;p=linux-2.6

cfq: fix IOPRIO_CLASS_IDLE accounting

Spotted by Nick <gentuu@gmail.com>, hopefully can explain the second trace in
http://bugzilla.kernel.org/show_bug.cgi?id=9180.

If ->async_idle_cfqq != NULL cfq_put_async_queues() puts it IOPRIO_BE_NR times
in a loop. Fix this.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index e47a9309eb..61a3f22eee 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -2068,9 +2068,10 @@ static void cfq_put_async_queues(struct cfq_data *cfqd)
 			cfq_put_queue(cfqd->async_cfqq[0][i]);
 		if (cfqd->async_cfqq[1][i])
 			cfq_put_queue(cfqd->async_cfqq[1][i]);
-		if (cfqd->async_idle_cfqq)
-			cfq_put_queue(cfqd->async_idle_cfqq);
 	}
+
+	if (cfqd->async_idle_cfqq)
+		cfq_put_queue(cfqd->async_idle_cfqq);
 }
 
 static void cfq_exit_queue(elevator_t *e)