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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 118F9C433F5 for ; Tue, 12 Oct 2021 10:36:41 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 D692261076 for ; Tue, 12 Oct 2021 10:36:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D692261076 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc: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=e6t5W1KUX6h2ZJ101MN37vRpizV9Go13L8ONcgQnwZw=; b=31MWrraqwDioHg Z0UOUmTYe3NosaUYzeLE1+cqlqwdNEaWfKX2QOB2pke/39xGHCPNPxDLn2qdo3k66lykeFoYE3hxr HiKJyl6LcwCHB6lqVq66o6momp+dP00DZprjhp9JD0q6Xeps8YZF+WEDuNF9JeneDJa8iBaR00gkJ WrUXTxi2ghiFym/GkM5hBxPj6WviLurdD/UWed1fNAbrXe720XyVPDr8TZkH0DUhfYIYzhpLj3FvX TP/FNJsL/oySx9BLeraRgpmHNfC8dJJTtM0T5L2QExLl8gauWPRLdGJW454qo8237ya6YfY3H1wZ9 6aixeyTuFeuCqpKawDxQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1maF91-00CSBO-5c; Tue, 12 Oct 2021 10:36:27 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1maF8y-00CSAg-UM for linux-nvme@lists.infradead.org; Tue, 12 Oct 2021 10:36:26 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 6276A67373; Tue, 12 Oct 2021 12:36:20 +0200 (CEST) Date: Tue, 12 Oct 2021 12:36:20 +0200 From: Christoph Hellwig To: Ming Lei Cc: Jens Axboe , Christoph Hellwig , linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, Chaitanya Kulkarni , Sagi Grimberg , Keith Busch , Bart Van Assche Subject: Re: [PATCH V3 4/6] nvme: paring quiesce/unquiesce Message-ID: <20211012103620.GB29640@lst.de> References: <20211009034713.1489183-1-ming.lei@redhat.com> <20211009034713.1489183-5-ming.lei@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20211009034713.1489183-5-ming.lei@redhat.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211012_033625_153349_F93F67F1 X-CRM114-Status: GOOD ( 17.37 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 Sat, Oct 09, 2021 at 11:47:11AM +0800, Ming Lei wrote: > The current blk_mq_quiesce_queue() and blk_mq_unquiesce_queue() always > stops and starts the queue unconditionally. And there can be concurrent > quiesce/unquiesce coming from different unrelated code paths, so > unquiesce may come unexpectedly and start queue too early. > > Prepare for supporting concurrent quiesce/unquiesce from multiple > contexts, so that we can address the above issue. > > NVMe has very complicated quiesce/unquiesce use pattern, add one atomic > bit for makeiing sure that blk-mq quiece/unquiesce is always called in > pair. Can you explain the need for these bits a little more? If they are unbalanced we should probably fix the root cause. What issues did you see? _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme