From: Stefan Bühler <source@stbuehler.de>
Date: Wed, 24 Apr 2019 21:54:19 +0000 (+0200)
Subject: io_uring: remove unnecessary barrier after updating SQ head
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9e4c15a3939448d2ea9b9bf59561183bbe3fdc49;p=linux.git

io_uring: remove unnecessary barrier after updating SQ head

There is no operation afterwards to order with.

Signed-off-by: Stefan Bühler <source@stbuehler.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 3671a654a1469..d3c57ee233fe7 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1798,12 +1798,6 @@ 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();
 	}
 }