From: Aleksei Zakharov <zakharov.a.g@yandex.ru>
Date: Wed, 24 Apr 2019 10:23:29 +0000 (+0800)
Subject: block: avoid setting nr_requests to current value
X-Git-Tag: Ubuntu-4.15.0-51.55~30
X-Git-Url: https://git.proxmox.com/?p=mirror_ubuntu-bionic-kernel.git;a=commitdiff_plain;h=ac99bae94f02525332430d4cc27e579a21f10c18

block: avoid setting nr_requests to current value

BugLink: https://bugs.launchpad.net/bugs/1815733

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>
(backported from commit e5fa81408fb43ebabde65938ef8b20ae879017e7)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Acked-by: Kleber Souza <kleber.souza@canonical.com>
Acked-by: AceLan Kao <acelan.kao@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
---

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 2f8436314985..67a80fd597e1 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2792,6 +2792,9 @@ 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);
 
 	ret = 0;