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[209.132.180.67]) by mx.google.com with ESMTP id x5si27130392pga.440.2018.11.16.02.08.47; Fri, 16 Nov 2018 02:09:01 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389658AbeKPUSN (ORCPT + 99 others); Fri, 16 Nov 2018 15:18:13 -0500 Received: from mx2.suse.de ([195.135.220.15]:43016 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727454AbeKPUSN (ORCPT ); Fri, 16 Nov 2018 15:18:13 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 714D6AEBD; Fri, 16 Nov 2018 10:06:33 +0000 (UTC) Subject: Re: [PATCH] nvme: allow ANA support to be independent of native multipathing To: Christoph Hellwig Cc: Mike Snitzer , linux-nvme@lists.infradead.org, Keith Busch , Sagi Grimberg , axboe@kernel.dk, Martin Wilck , lijie , xose.vazquez@gmail.com, chengjike.cheng@huawei.com, shenhong09@huawei.com, dm-devel@redhat.com, wangzhoumengjian@huawei.com, christophe.varoqui@opensvc.com, bmarzins@redhat.com, sschremm@netapp.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: <20181112215323.GA7983@redhat.com> <20181113161838.GC9827@localhost.localdomain> <20181113180008.GA12513@redhat.com> <20181114053837.GA15086@redhat.com> <30cf7af7-8826-55bd-e39a-4f81ed032f6d@suse.de> <20181114174746.GA18526@redhat.com> <87c931e5-4ac9-1795-8d40-cc5541d3ebcf@suse.de> <20181115174605.GA19782@redhat.com> <20181116091458.GA17267@lst.de> <37098edd-4dea-b58f-bca6-3be9af8ec4ee@suse.de> <20181116094947.GA19296@lst.de> From: Hannes Reinecke Message-ID: Date: Fri, 16 Nov 2018 11:06:32 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.0 MIME-Version: 1.0 In-Reply-To: <20181116094947.GA19296@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/16/18 10:49 AM, Christoph Hellwig wrote: > On Fri, Nov 16, 2018 at 10:40:40AM +0100, Hannes Reinecke wrote: >>>> Introduce ability to always re-read ANA log page as required due to ANA >>>> error and make current ANA state available via sysfs -- even if native >>>> multipathing is disabled on the host (e.g. nvme_core.multipath=N). >>> >>> The first part I could see, but I still want to make it conditional >>> in some way as nvme is going into deeply embedded setups, and I don't >>> want to carry the weight of the ANA code around for everyone. >>> >> Can you clarify this a bit? >> We _do_ have the NVME multipath config option to deconfigure the whole >> thing during compile time; that isn't influenced with this patch. >> So are you worried about the size of the ANA implementation itself? >> Or are you worried about the size of the ANA structures? > > I just see the next step of wanting to move ANA code into the core > which is implied above. Really, I couldn't care less _where_ the ANA code lives. If the size of which is any concern we can even make it configurable of sorts. >> >>> The second I fundamentally disagree with. And even if you found agreement >>> it would have to be in a separate patch as it is a separate feature. >>> >> Why? Where's the problem with re-reading the ANA log pages if we get an >> event indicating that we should? > > "second" here means the sysfs file. > Ok, so would you be happy with making ANA support configurable? Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg)