From patchwork Wed Apr 24 21:54:20 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Stefan_B=C3=BChler?= X-Patchwork-Id: 10915793 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D5B4B1708 for ; Wed, 24 Apr 2019 21:54:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C40D228B8F for ; Wed, 24 Apr 2019 21:54:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B89E328BA0; Wed, 24 Apr 2019 21:54:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,DKIM_ADSP_ALL, DKIM_INVALID,DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6596328B8F for ; Wed, 24 Apr 2019 21:54:27 +0000 (UTC) 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_B=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 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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;