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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id A80DBC38145 for ; Tue, 6 Sep 2022 04:50:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=05njV07sJBMDroait06pY76fcRd4k+pymsG8nnNmo8M=; b=Rv1BPNkXJKW3h+luLCzqlYXI1q QN0jNhh/NCN206mIwtPuAsKH9cclqkdLOoECHtmUMkyrKjCdoL3GfguGScoSWbAqAHopDb6f0fs2y VG1xNBqV2bPtYau+wga6iOH7YiZZ78S1RG2dYVUyntWOMl6ovwTpvJXM6911QpWeGDr8o1xDtRGtY SOJjy6VayTOljwJTI06qUf0AprwnzODVPkdxxZ4Pr/2SY03TzjTjYmiZvA68rdDR/Yv32qXGwFEV1 NokpzRPoHyLM0G2EIdiU0UBC1F4j69YMxIwtZ8CglDottorjZqYBwvMg/4sc2CO3wwwpb6nPyMRki InyhB9/w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oVQXT-008Hny-6m; Tue, 06 Sep 2022 04:50:19 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oVQXR-008HTy-SL for linux-nvme@bombadil.infradead.org; Tue, 06 Sep 2022 04:50:17 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=05njV07sJBMDroait06pY76fcRd4k+pymsG8nnNmo8M=; b=TYYWbbKjVYP6QfnTxhI4W44na5 d0mP6NvWV0XoIhiwuNpfFLt5UIyCEobXdwrUE67yhjsB6plYLwsMTIWlwZUf6MVrG9Lln9ehwrnCf qdGt4PCH0YHWg9a2+OG6qCTnDbzUarqIZ/ky2Ll0bruJ5JKmkjU90UqyBQRz5X6uYPIomE4fxTpEK bTJNmlqw/uVWe/JtV+3XV5UyE3wnD6/h36y15Qs21HumRNuMb53g4+2yDiOp/UO1kjecQ6BnmvRnt AysnKPvfJ3WQRT5/fqfD34SpwBCrp0Dj0J3tyJtxZsFgkhOKBOsnpEuTMutGwfsY6sNj0c/Fd3rEt 8Nyzv8kw==; Received: from verein.lst.de ([213.95.11.211]) by desiato.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oVQXN-00A4zT-F9 for linux-nvme@lists.infradead.org; Tue, 06 Sep 2022 04:50:16 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 550CD68AFE; Tue, 6 Sep 2022 06:49:41 +0200 (CEST) Date: Tue, 6 Sep 2022 06:49:41 +0200 From: Christoph Hellwig To: Chao Leng Cc: Ming Lei , Christoph Hellwig , linux-nvme@lists.infradead.org, Yi Zhang , Sagi Grimberg , Keith Busch Subject: Re: [PATCH 1/2] nvme: make NVMe freeze API reliably Message-ID: <20220906044941.GB32525@lst.de> References: <20220821084754.340585-1-ming.lei@redhat.com> <20220821084754.340585-2-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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-20220906_055014_675095_B399527D X-CRM114-Status: GOOD ( 12.38 ) 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: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Thu, Aug 25, 2022 at 06:02:33PM +0800, Chao Leng wrote: > > > On 2022/8/21 16:47, Ming Lei wrote: >> From: Keith Busch >> >> In some corner cases[1], freeze wait and unfreeze API may be called on >> unfrozen queue, add one per-ns flag of NVME_NS_FREEZE to make these >> freeze APIs more reliably, then this kind of issues can be avoided. >> And similar approach has been applied on stopping/quiescing nvme queues. > This leads to another problem: the process that needs to be > in the frozen state is not actually frozen. Where do frozen processes come into play here?