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=-5.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 BEDAFC1975A for ; Tue, 17 Mar 2020 22:43:53 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7481F20674 for ; Tue, 17 Mar 2020 22:43:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="BO6Oj0W4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7481F20674 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E76806B0003; Tue, 17 Mar 2020 18:43:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E27A06B0006; Tue, 17 Mar 2020 18:43:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D15B46B0007; Tue, 17 Mar 2020 18:43:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0145.hostedemail.com [216.40.44.145]) by kanga.kvack.org (Postfix) with ESMTP id B671F6B0003 for ; Tue, 17 Mar 2020 18:43:52 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 76786181AC9BF for ; Tue, 17 Mar 2020 22:43:52 +0000 (UTC) X-FDA: 76606333104.29.edge99_4a776868b74c X-HE-Tag: edge99_4a776868b74c X-Filterd-Recvd-Size: 3850 Received: from hqnvemgate24.nvidia.com (hqnvemgate24.nvidia.com [216.228.121.143]) by imf15.hostedemail.com (Postfix) with ESMTP for ; Tue, 17 Mar 2020 22:43:51 +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 ; Tue, 17 Mar 2020 15:42:14 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Tue, 17 Mar 2020 15:43:50 -0700 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Tue, 17 Mar 2020 15:43:50 -0700 Received: from rcampbell-dev.nvidia.com (172.20.13.39) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 17 Mar 2020 22:43:50 +0000 Subject: Re: [PATCH 3/4] mm: simplify device private page handling in hmm_range_fault To: Christoph Hellwig CC: Jason Gunthorpe , Dan Williams , Bharata B Rao , =?UTF-8?Q?Christian_K=c3=b6nig?= , Ben Skeggs , Jerome Glisse , , , , , References: <20200316193216.920734-1-hch@lst.de> <20200316193216.920734-4-hch@lst.de> <7256f88d-809e-4aba-3c46-a223bd8cc521@nvidia.com> <20200317073454.GA5843@lst.de> X-Nvconfidentiality: public From: Ralph Campbell Message-ID: Date: Tue, 17 Mar 2020 15:43:47 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20200317073454.GA5843@lst.de> X-Originating-IP: [172.20.13.39] X-ClientProxiedBy: HQMAIL107.nvidia.com (172.20.187.13) To HQMAIL107.nvidia.com (172.20.187.13) Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1584484934; bh=2jZcafW9RvOYHM38DORumH5I1RwtHgySTT0aFTjNQuM=; h=X-PGP-Universal:Subject:To:CC:References:X-Nvconfidentiality:From: Message-ID:Date:User-Agent:MIME-Version:In-Reply-To: X-Originating-IP:X-ClientProxiedBy:Content-Type:Content-Language: Content-Transfer-Encoding; b=BO6Oj0W4mrkkdhTl+awAc50wbgQvTWvpmTQJd/2gjT8Fd+LDVf2mLhhknF+8JnEii UaRmmvajifNBnwzUIOCqy6/EAGyEHyVYr1Kj2tWuvuvPtu7kpQK4J/Zv/B4gTDOuoD UbsJb+Tz87eXdjbZjuy0rSVdqaG0ENtxEBqcXXztnwYOgYpMyi+jZf6Rn5iAesnROj iOHGVOKHirMOlGtyyAUQQHj0vnAK8rP0ogkGB3hj62Ms0+/utWir0qA5OzGhWhSSnT SQa2st7gbC6N2yS5vY3VS7bfM/HHpXgfXR7shKofCnTxEngkRmU50nVYaq/uwSSzFi z5eJsuv+P/Isw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 3/17/20 12:34 AM, Christoph Hellwig wrote: > On Mon, Mar 16, 2020 at 03:49:51PM -0700, Ralph Campbell wrote: >> On 3/16/20 12:32 PM, Christoph Hellwig wrote: >>> Remove the code to fault device private pages back into system memory >>> that has never been used by any driver. Also replace the usage of the >>> HMM_PFN_DEVICE_PRIVATE flag in the pfns array with a simple >>> is_device_private_page check in nouveau. >>> >>> Signed-off-by: Christoph Hellwig >> >> Getting rid of HMM_PFN_DEVICE_PRIVATE seems reasonable to me since a driver can >> look at the struct page but what if a driver needs to fault in a page from >> another device's private memory? Should it call handle_mm_fault()? > > Obviously no driver cared for that so far. Once we have test cases > for that and thus testable code we can add code to fault it in from > hmm_vma_handle_pte. > I'm OK with the series. I think I would have been less confused if I looked at patch 4 then 3.