From: Aleksei Zakharov <zakharov.a.g@yandex.ru>
Date: Fri, 8 Feb 2019 16:14:05 +0000 (+0300)
Subject: block: avoid setting nr_requests to current value
X-Git-Tag: v5.1-rc1~9^2~96
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=e5fa81408fb43ebabde65938ef8b20ae879017e7;p=uclinux-h8%2Flinux.git

block: avoid setting nr_requests to current value

There's no reason to freeze queue and set nr_requests value
if current value is the same.

Signed-off-by: Aleksei Zakharov <zakharov.a.g@yandex.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 8a825aebc6b5..44d471ff8754 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3089,6 +3089,9 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
 	if (!set)
 		return -EINVAL;
 
+	if (q->nr_requests == nr)
+		return 0;
+
 	blk_mq_freeze_queue(q);
 	blk_mq_quiesce_queue(q);