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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 4E866C33CAF for ; Thu, 16 Jan 2020 20:33:22 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 20C8B2073A for ; Thu, 16 Jan 2020 20:33:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="B3a+nJMY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 20C8B2073A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8E7476E265; Thu, 16 Jan 2020 20:33:21 +0000 (UTC) Received: from hqnvemgate24.nvidia.com (hqnvemgate24.nvidia.com [216.228.121.143]) by gabe.freedesktop.org (Postfix) with ESMTPS id B6CEA6E265 for ; Thu, 16 Jan 2020 20:33:20 +0000 (UTC) Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 16 Jan 2020 12:32:23 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Thu, 16 Jan 2020 12:33:20 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Thu, 16 Jan 2020 12:33:20 -0800 Received: from [10.2.160.8] (10.124.1.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 16 Jan 2020 20:33:19 +0000 Subject: Re: [PATCH v12 04/22] mm: devmap: refactor 1-based refcounting for ZONE_DEVICE pages To: Christoph Hellwig References: <20200107224558.2362728-1-jhubbard@nvidia.com> <20200107224558.2362728-5-jhubbard@nvidia.com> <20200115152306.GA19546@infradead.org> <4707f191-86f8-db4a-c3de-0a84b415b658@nvidia.com> <20200116093712.GA11011@infradead.org> From: John Hubbard X-Nvconfidentiality: public Message-ID: Date: Thu, 16 Jan 2020 12:30:26 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200116093712.GA11011@infradead.org> X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL111.nvidia.com (172.20.187.18) To HQMAIL107.nvidia.com (172.20.187.13) Content-Language: en-US DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1579206743; bh=EQpRDmAadXrYPrWI0G8MSYR7uqZas3jC8zZTGB2Hfnk=; h=X-PGP-Universal:Subject:To:CC:References:From:X-Nvconfidentiality: Message-ID:Date:User-Agent:MIME-Version:In-Reply-To: X-Originating-IP:X-ClientProxiedBy:Content-Type:Content-Language: Content-Transfer-Encoding; b=B3a+nJMY1e/PvYKAT7LBGlwa/kugx+AfoqbMvj/EyT3hxrpeJ7sQMsWMdJQlxzKho jy2YJ47pzKLca9QqrMI2qpXvMA46wU1dfzb3yzBY8NTIGraOJl+bg0Pq/59xdUBLNS /bnG7fSxkcGgsGNzlzCgQWOOUXWSDOgkuZxsp+8IlbnfinKUcliv6MqWXSulEsNyXv EIh2GmNEud9hkIp72ZuHMkWrhgwhMDnw4xjgxdJ2+W90cT6UoDxxzOl8PDPrjhQ9p0 IklTRq4Mlrg+UVduRNOxi7jCeWI/98S5JYFUwVk8qaaNzULyUj0q2zlHy86g76FXcR ZxTytDejWJDcw== X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Michal Hocko , Jan Kara , kvm@vger.kernel.org, linux-doc@vger.kernel.org, David Airlie , Dave Chinner , dri-devel@lists.freedesktop.org, LKML , linux-mm@kvack.org, Paul Mackerras , linux-kselftest@vger.kernel.org, Ira Weiny , Christoph Hellwig , Jonathan Corbet , linux-rdma@vger.kernel.org, Michael Ellerman , Jason Gunthorpe , Vlastimil Babka , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , linux-media@vger.kernel.org, Shuah Khan , linux-block@vger.kernel.org, =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Al Viro , "Kirill A . Shutemov" , Dan Williams , Mauro Carvalho Chehab , bpf@vger.kernel.org, Magnus Karlsson , Jens Axboe , netdev@vger.kernel.org, Alex Williamson , linux-fsdevel@vger.kernel.org, Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S . Miller" , Mike Kravetz Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 1/16/20 1:37 AM, Christoph Hellwig wrote: > On Wed, Jan 15, 2020 at 01:19:41PM -0800, John Hubbard wrote: >> On 1/15/20 7:23 AM, Christoph Hellwig wrote: >> ... >>> >>> I'm really not sold on this scheme. Note that I think it is >>> particularly bad, but it also doesn't seem any better than what >>> we had before, and it introduced quite a bit more code. >>> >> >> Hi Christoph, >> >> All by itself, yes. But the very next patch (which needs a little >> rework for other reasons, so not included here) needs to reuse some of >> these functions within __unpin_devmap_managed_user_page(): > > Well, then combine it with the series that actually does the change. OK, that makes sense. I just double-checked with a quick test run, that it doesn't have dependencies with the rest of this series, and it came out clean, so: Andrew, could you please remove just this one patch from mmotm and linux-next? > > Also my vaguely recollection is that we had some idea on how to get rid > of the off by one refcounting for the zone device pages, which would be > a much better outcome. > Yes, I recall that Dan Williams mentioned it, but I don't think he provided any details yet. thanks, -- John Hubbard NVIDIA _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel