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=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 4E6B7C433E0 for ; Wed, 22 Jul 2020 16:01:05 +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 ECE6820717 for ; Wed, 22 Jul 2020 16:01:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="lF2wMfay"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="s9YMEoGq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECE6820717 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=SpkwpJgaXZwrFzgvbFDwTC8IrQwAKnkp1Rj2XH7XbRE=; b=lF2wMfayPeo61n/fpVuxxW/df 0yYMg9uSZqs5WfBbTQ1K+PLQ7MYVQLJtmaoXVLIZQXt9t6RRJI4WTCcMxNyutJiHxQxB/gP7qOvH9 izDdOjKXjumMflMjWkwJ4JnCvq39bW7A/lf3O96MgejJdrLw5gdy6reTxTqcH2jrgzOQzv+H2rXSA TvaLaUl7xFp3tXr4wEWk6yIFN7hHnPQ2ZNRzAQnFg7X0EVmmGr+5cfsKYYsC67nl2QgBwQCeewoSe QdLWJZfnKZetiqQUQzbk4Hr1v5OM30iDh7nFyX9rboeXiqqziYvHVtpm+4LJl0XWEGIjyQWE2aZHk 2z9/G45gw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jyHAy-0003cY-7s; Wed, 22 Jul 2020 16:01:00 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jyHAw-0003bx-79 for linux-nvme@lists.infradead.org; Wed, 22 Jul 2020 16:00:59 +0000 Received: from dhcp-10-100-145-180.wdl.wdc.com (unknown [199.255.45.60]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 19A41206F5; Wed, 22 Jul 2020 16:00:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595433656; bh=JBsdOmGp5ZrTOx2S0cCWDjtEQSd/GUKSZRFFJkMF5vM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=s9YMEoGqqzxYMSxILWDeUxqUUo7yzeK9/oE86lTr3cb7Gf4MNVbr/JMhGZkz7UPr6 F8/n2RwETbLhdz9NGOf/UTz5sX/+Y327R5LiZIlC6eR6I/N/QDOH5ZM5uNT2UzN05N D8gfYcyjOldo5qv35k0hyg2vIkj6DAYLnu3ZjqDM= Date: Wed, 22 Jul 2020 09:00:54 -0700 From: Keith Busch To: Chao Leng Subject: Re: [PATCH] nvme-core: reduce io pause time when fail over Message-ID: <20200722160054.GA1363519@dhcp-10-100-145-180.wdl.wdc.com> References: <20200722093633.31347-1-lengchao@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200722093633.31347-1-lengchao@huawei.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200722_120058_330788_F31A4F6D X-CRM114-Status: GOOD ( 10.28 ) 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: axboe@fb.com, hch@lst.de, linux-nvme@lists.infradead.org, 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 Wed, Jul 22, 2020 at 05:36:33PM +0800, Chao Leng wrote: > To reduce io pause time, nvme_stop_queues use > blk_mq_quiesce_queue_nowait to quiesce the queue, nvme_stop_queues wait > all ongoing dispatches completed after all queues has been quiesced. The comment above blk_mq_quiesce_queue_nowait() wants to remove this function. I'm not sure we should be introducing more users if that's the case. Using synchronize_rcu() at the end may be looking to much into blk-mq's internal quiesce implementation. It happens to be the right thing to do for non-blocking hctx, so this patch assumes that will be true for any nvme request_queue. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme