diff --git a/[refs] b/[refs]
index 6d4adfd0daba..a7b0281a1bd4 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a3b8d92d25212c5b6534ae9b347ed2858de78336
+refs/heads/master: b9d8f4c73b1af4cfd53f819bf84c2bce31232275
diff --git a/trunk/block/cfq-iosched.c b/trunk/block/cfq-iosched.c
index 5009af490a0c..b19cd684bf12 100644
--- a/trunk/block/cfq-iosched.c
+++ b/trunk/block/cfq-iosched.c
@@ -1749,6 +1749,12 @@ static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd,
 	if (CFQQ_SEEKY(cur_cfqq))
 		return NULL;
 
+	/*
+	 * Don't search priority tree if it's the only queue in the group.
+	 */
+	if (cur_cfqq->cfqg->nr_cfqq == 1)
+		return NULL;
+
 	/*
 	 * We should notice if some of the queues are cooperating, eg
 	 * working closely on the same area of the disk. In that case,