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=-5.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 27044C433DB for ; Fri, 19 Feb 2021 13:41:01 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 93E5164ED2 for ; Fri, 19 Feb 2021 13:41:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 93E5164ED2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=UIaJDxWJgdp1jSFFl4yDpmfs6i6bViwcY9Rz+yO685s=; b=voHAYb4yyFdEuqGYIpBrK05bO qL+EiKtyVsl+yEtPBVqp2t/m2AmPI49/2ylaA9vWkwdbLQ4Hkf87R5TZ0pAWOCDxO/xnyHEAp2+VF LiVFDyzhL94nxuHIGDHPYMowzIidYkFbgrSE4Ui0oGawB3VmQw7evypvorg6x2N5drhJQnj9BmVnL Dvwdd+aM8s5wUJOoYLN/LeHgy6qW9Rtj4EAEdxoG2Qb4mSHZDLfMZzcnKgffXv0ip6DQToMZzshya SBi8J2SDpYGQEDddC52UFFG/xsCqCi4XldKd5AMiBB/vvWT3RFbzoEOOSAEgywZZeBVshmhiULnFJ DzVwEngEg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1lD60y-00073I-IF; Fri, 19 Feb 2021 13:40:12 +0000 Received: from mail-pl1-x62d.google.com ([2607:f8b0:4864:20::62d]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1lD60w-00072s-6Q for linux-nvme@lists.infradead.org; Fri, 19 Feb 2021 13:40:11 +0000 Received: by mail-pl1-x62d.google.com with SMTP id a9so3376396plh.8 for ; Fri, 19 Feb 2021 05:40:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=PozDEM9kP5pBFkg36mJjr8T8BjM1aUeLPSpcF1ah40w=; b=cCASVJvG1W5EJei9ZeBVqKU2qzdhQFJaiSR7/+k8ep4dMxVB3Mv2iVo0VLNqcTDI2X pCirkza7kOY+q1RnpezjGLN8v76pA/g+K+6u0sgamBK7shWmZCdwwFwyp50CnB43QOHb a8urXbge1KWaIen3X2n7+PVrPjl/OzUbnX+83jdE/b1LijzaC0YvTcPy6uEp2r7PSH4U d+qVrOfA7XY0F6zxVvp8040pH1Nk/+ZEzZaAYrSyRLyLQm++kV6ErfthBDU5BwPrWirz VuxTopv8TqsUK2DDozn2PFjCTUqxUTqWZp1C81ILntrRtBWEK9WG3havRRe19GlxLrX2 NBRw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=PozDEM9kP5pBFkg36mJjr8T8BjM1aUeLPSpcF1ah40w=; b=GImJxNmqhQneCHUj4eW/DPm0/W3XMw2m6aAoEJspCT8g9CvZeZesr4h7OhfrTDf7F3 /+zwZhmHTZ49Rg3eeo9e8P0xTv126ACB+V6rZO9G/khZG8q7w41hIHPRu5fAFVZm9oiK 3L/74wM4iXmc7yxchbmV5Hqq2+J7CoWprrPF1qYyzaK3LLKNFRZHhb+X0BkcuKNWyNpn StmhjYQvYOp8Xg7BkUFa5rZ5MW3LRb3CaB1U5C5/m9mNdi3oN7V+Dtt11Q5+dT4Hod3E d9jT0iN1LVvvxspDM0oDHnbbOeZbFQzlCklQf4ZNEpFYTeJ/JPuAS2kQMp/o27/BKFSD xhVg== X-Gm-Message-State: AOAM533yPMsuVdBZ/WSLZkttnB3ETgCBKuEwM3kyvhhB8rwiHlN6HWS6 eUKjtNT7ZLnL/VC2n6LlI8+tww== X-Google-Smtp-Source: ABdhPJxsQLYWTA+NgMdLmi4kmhN/kc5Muei6d7Sqk7m6fMS90LhU36Fs3SrcGH23G5w7c8//pCLfYw== X-Received: by 2002:a17:902:e5c8:b029:e3:9201:5121 with SMTP id u8-20020a170902e5c8b02900e392015121mr9103446plf.84.1613742006027; Fri, 19 Feb 2021 05:40:06 -0800 (PST) Received: from [192.168.1.134] ([66.219.217.173]) by smtp.gmail.com with ESMTPSA id t7sm9465378pgr.53.2021.02.19.05.40.04 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 19 Feb 2021 05:40:04 -0800 (PST) Subject: Re: [PATCH 1/2] nvme-pci; remove the barriers nvme_irq() To: Chaitanya Kulkarni , linux-nvme@lists.infradead.org References: <20210219063726.63728-1-chaitanya.kulkarni@wdc.com> From: Jens Axboe Message-ID: <80fc53d2-4f35-7c72-5cc5-3ec13c5ee51a@kernel.dk> Date: Fri, 19 Feb 2021 06:40:04 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210219063726.63728-1-chaitanya.kulkarni@wdc.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210219_084010_266077_FD057097 X-CRM114-Status: GOOD ( 13.22 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kbusch@kernel.org, hch@lst.de, sagi@grimberg.me Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On 2/18/21 11:37 PM, Chaitanya Kulkarni wrote: > The barriers were added to the nvme_irq() in the > commit 3a7afd8ee42a ("nvme-pci: remove the CQ lock for interrupt driven queues") > to prevent compiler from doing memory optimization for the variabes that > were protected previously by spinlock in nvme_irq() at completion queue > processing and with queue head check condition.. > > The variable nvmeq->last_cq_head from those checks was removed in the > commit f6c4d97b0d82 ("nvme/pci: Remove last_cq_head")") that was > preventing poll queues from mistakenly triggering the spurious > interrupt detection. > > Remove the barriers which were protecting the updates to the variables. Would seem prudent to just ask the original submitter to send a v2 of his patch, as that's where it came from. -- Jens Axboe _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme