From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=3.0 tests=DKIM_ADSP_ALL,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E853C282CE for ; Wed, 24 Apr 2019 21:54:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E6E220685 for ; Wed, 24 Apr 2019 21:54:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=stbuehler.de header.i=@stbuehler.de header.b="bYVZHD+N" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731876AbfDXVy0 (ORCPT ); Wed, 24 Apr 2019 17:54:26 -0400 Received: from mail.stbuehler.de ([5.9.32.208]:41022 "EHLO mail.stbuehler.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731786AbfDXVyZ (ORCPT ); Wed, 24 Apr 2019 17:54:25 -0400 Received: from chromobil.fritz.box (unknown [IPv6:2a02:8070:a29c:5000:823f:5dff:fe0f:b5b6]) by mail.stbuehler.de (Postfix) with ESMTPSA id CE742C030C5; Wed, 24 Apr 2019 21:54:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=stbuehler.de; s=stbuehler1; t=1556142864; bh=66skNcbVaC2Y2x/luaOKJisPsjdX43vHw1Fl19FcSLs=; h=From:To:Subject:Date:In-Reply-To:References:From; b=bYVZHD+Nw1AlYM056L8d2JmLZLQSQMMqAKxmEO5jAhmWGVAkvUxYUl2nofwhs+luC kTj+aMeoeZjswI8p6NFLHPG1+w1D655yVTVfMdllAhNUHQO02VD9YKI/9oW5e1XBYA cd1BbGJW4zBHreM+wqon4UftPCrZ+yw48BnL+9ak= From: =?UTF-8?q?Stefan=20B=C3=BChler?= To: Jens Axboe , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH barrier cleanup v1 5/7] io_uring: remove unnecessary barrier before reading SQ tail Date: Wed, 24 Apr 2019 23:54:20 +0200 Message-Id: <20190424215422.7404-5-source@stbuehler.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190424215422.7404-1-source@stbuehler.de> References: <54496e17-97de-9f9a-9972-c448226bb768@stbuehler.de> <20190424215422.7404-1-source@stbuehler.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org There is no operation before to order with. Signed-off-by: Stefan Bühler --- fs/io_uring.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 31357cc0e8e6..f93a9fca8311 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1828,8 +1828,6 @@ static bool io_get_sqring(struct io_ring_ctx *ctx, struct sqe_submit *s) * though the application is the one updating it. */ head = ctx->cached_sq_head; - /* See comment at the top of this file */ - smp_rmb(); /* make sure SQ entry isn't read before tail */ if (head == smp_load_acquire(&ring->r.tail)) return false; -- 2.20.1