From f1319b356bf7087551fb48652212fe97e1d07187 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20B=C3=BChler?= <source@stbuehler.de>
Date: Thu, 15 Apr 2021 17:30:57 +0800
Subject: [PATCH] io_uring: remove unnecessary barrier after updating SQ head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

mainline inclusion
from mainline-5.1
commit 9e4c15a3939448d2ea9b9bf59561183bbe3fdc49
category: feature
bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27
CVE: NA
---------------------------

There is no operation afterwards to order with.

Signed-off-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>
---
 fs/io_uring.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 4e5dbbae0766..8e143aed7365 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1795,12 +1795,6 @@ static void io_commit_sqring(struct io_ring_ctx *ctx)
 		 * write new data to them.
 		 */
 		smp_store_release(&ring->r.head, ctx->cached_sq_head);
-
-		/*
-		 * write side barrier of head update, app has read side. See
-		 * comment at the top of this file
-		 */
-		smp_wmb();
 	}
 }
 
-- 
GitLab