From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: [RESEND PATCH] nvme: explicitly use normal NVMe error handling when appropriate Date: Thu, 13 Aug 2020 15:03:42 -0400 Message-ID: <20200813190342.GA6607@redhat.com> References: <20200807000755.GA28957@redhat.com> <510f5aff-0437-b1ce-f7ab-c812edbea880@grimberg.me> <20200807045015.GA29737@redhat.com> <20200810143620.GA19127@redhat.com> <20200810172209.GA19535@redhat.com> <20200813144811.GA5452@redhat.com> <20200813153623.GA30905@infradead.org> <20200813174704.GA6137@redhat.com> <20200813184349.GA8191@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20200813184349.GA8191@infradead.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com Content-Disposition: inline To: Christoph Hellwig Cc: Sagi Grimberg , linux-nvme@lists.infradead.org, dm-devel@redhat.com, Ewan Milne , Chao Leng , Keith Busch , "Meneghini, John" List-Id: dm-devel.ids On Thu, Aug 13 2020 at 2:43pm -0400, Christoph Hellwig wrote: > On Thu, Aug 13, 2020 at 01:47:04PM -0400, Mike Snitzer wrote: > > This is just a tweak to improve the high-level fault tree of core NVMe > > error handling. No functional change, but for such basic errors, > > avoiding entering nvme_failover_req is meaningful on a code flow level. > > Makes code to handle errors that need local retry clearer by being more > > structured, less circuitous. > > > > Allows NVMe core's handling of such errors to be more explicit and live > > in core.c rather than multipath.c -- so things like ACRE handling can be > > made explicitly part of core and not nested under nvme_failover_req's > > relatively obscure failsafe that returns false for anything it doesn't > > care about. > > If we're going that way I'd rather do something like the (untested) > patch below that adds a dispostion function with a function that > decides it and then just switches on it: YES! That is such a huge improvement (certainly on a code clarity level). I haven't reviewed or tested the relative performance or function of before vs after (will do) but I really like this approach. Thanks, Mike 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=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,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 2C327C433DF for ; Thu, 13 Aug 2020 19:04:01 +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 E15BF206B2 for ; Thu, 13 Aug 2020 19:04:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="e1akVKtn"; 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Thu, 13 Aug 2020 15:03:47 -0400 X-MC-Unique: bNM0J8yLNpeNbFS0oF8i_Q-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DDB74873088; Thu, 13 Aug 2020 19:03:45 +0000 (UTC) Received: from localhost (unknown [10.18.25.174]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CD61F6F9C9; Thu, 13 Aug 2020 19:03:42 +0000 (UTC) Date: Thu, 13 Aug 2020 15:03:42 -0400 From: Mike Snitzer To: Christoph Hellwig Subject: Re: [RESEND PATCH] nvme: explicitly use normal NVMe error handling when appropriate Message-ID: <20200813190342.GA6607@redhat.com> References: <20200807000755.GA28957@redhat.com> <510f5aff-0437-b1ce-f7ab-c812edbea880@grimberg.me> <20200807045015.GA29737@redhat.com> <20200810143620.GA19127@redhat.com> <20200810172209.GA19535@redhat.com> <20200813144811.GA5452@redhat.com> <20200813153623.GA30905@infradead.org> <20200813174704.GA6137@redhat.com> <20200813184349.GA8191@infradead.org> MIME-Version: 1.0 In-Reply-To: <20200813184349.GA8191@infradead.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=msnitzer@redhat.com X-Mimecast-Spam-Score: 0.001 X-Mimecast-Originator: redhat.com Content-Disposition: inline X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200813_150352_433602_62A6D06F X-CRM114-Status: GOOD ( 20.06 ) 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: Sagi Grimberg , Hannes Reinecke , linux-nvme@lists.infradead.org, dm-devel@redhat.com, Ewan Milne , Chao Leng , Keith Busch , "Meneghini, John" 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 Thu, Aug 13 2020 at 2:43pm -0400, Christoph Hellwig wrote: > On Thu, Aug 13, 2020 at 01:47:04PM -0400, Mike Snitzer wrote: > > This is just a tweak to improve the high-level fault tree of core NVMe > > error handling. No functional change, but for such basic errors, > > avoiding entering nvme_failover_req is meaningful on a code flow level. > > Makes code to handle errors that need local retry clearer by being more > > structured, less circuitous. > > > > Allows NVMe core's handling of such errors to be more explicit and live > > in core.c rather than multipath.c -- so things like ACRE handling can be > > made explicitly part of core and not nested under nvme_failover_req's > > relatively obscure failsafe that returns false for anything it doesn't > > care about. > > If we're going that way I'd rather do something like the (untested) > patch below that adds a dispostion function with a function that > decides it and then just switches on it: YES! That is such a huge improvement (certainly on a code clarity level). I haven't reviewed or tested the relative performance or function of before vs after (will do) but I really like this approach. Thanks, Mike _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme