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=-9.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 553BCC4741F for ; Wed, 7 Oct 2020 18:12:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C2A6E2177B for ; Wed, 7 Oct 2020 18:12:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="o+FdvXOp" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C2A6E2177B 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 15AB86B0068; Wed, 7 Oct 2020 14:12:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0E46D6B006E; Wed, 7 Oct 2020 14:12:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EEE398E0001; Wed, 7 Oct 2020 14:12:44 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0113.hostedemail.com [216.40.44.113]) by kanga.kvack.org (Postfix) with ESMTP id BEBAB6B0068 for ; Wed, 7 Oct 2020 14:12:44 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 4DB5E181AE867 for ; Wed, 7 Oct 2020 18:12:44 +0000 (UTC) X-FDA: 77345925048.03.frog30_000b8bf271d1 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin03.hostedemail.com (Postfix) with ESMTP id 2CF5428A4E8 for ; Wed, 7 Oct 2020 18:12:44 +0000 (UTC) X-HE-Tag: frog30_000b8bf271d1 X-Filterd-Recvd-Size: 3456 Received: from hqnvemgate25.nvidia.com (hqnvemgate25.nvidia.com [216.228.121.64]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Wed, 7 Oct 2020 18:12:43 +0000 (UTC) Received: from hqmail.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, AES256-SHA) id ; Wed, 07 Oct 2020 11:11:46 -0700 Received: from rcampbell-dev.nvidia.com (10.124.1.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 7 Oct 2020 18:12:40 +0000 Subject: Re: [PATCH] ext4/xfs: add page refcount helper To: Jan Kara CC: , , , , , , Dan Williams , Matthew Wilcox , "Alexander Viro" , Theodore Ts'o , "Christoph Hellwig" , Andreas Dilger , "Darrick J. Wong" , Andrew Morton References: <20201006230930.3908-1-rcampbell@nvidia.com> <20201007082517.GC6984@quack2.suse.cz> X-Nvconfidentiality: public From: Ralph Campbell Message-ID: Date: Wed, 7 Oct 2020 11:12:40 -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: <20201007082517.GC6984@quack2.suse.cz> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL101.nvidia.com (172.20.187.10) To HQMAIL107.nvidia.com (172.20.187.13) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1602094306; bh=lUvgpT2dTAjc7L2GQJN23iB+8LFxnscOP+RQUFKZzSU=; h=Subject:To:CC:References:X-Nvconfidentiality:From:Message-ID:Date: User-Agent:MIME-Version:In-Reply-To:Content-Type:Content-Language: Content-Transfer-Encoding:X-Originating-IP:X-ClientProxiedBy; b=o+FdvXOp7EzIyvwJEGGRsWIIvAKdYxiUjP4FaudBCF5tqtRlUM5mSnvldVEx36PfR 1aWjXJX3cbuJ7Atpubl/0AHI642RUHyderrltQL3vMBrDg8gwiwV7U9TzPMU/ZJHwL Q8ZSz2uk/NvYwAsL3dgNttmxAQlPr1SM/DIUjacJVlS/BWCCGPh0LfkAt0rILq8Ydx 9WXnyAZ3kmgVCXUpIpyKRfB7115WfJo9GwBDm0wtRxubW5SSlC6khrlAyfPqtAwipT xKAu+/xSyEM++gga5LHl6KFTQoOC1yVE4sPLYQHQ8enCOgH/tllJl9uOy2ayx+RLbP 5Q+o0MZ9gWpQA== 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 10/7/20 1:25 AM, Jan Kara wrote: > On Tue 06-10-20 16:09:30, Ralph Campbell wrote: >> There are several places where ZONE_DEVICE struct pages assume a reference >> count == 1 means the page is idle and free. Instead of open coding this, >> add a helper function to hide this detail. >> >> Signed-off-by: Ralph Campbell >> Reviewed-by: Christoph Hellwig > > Looks as sane direction but if we are going to abstract checks when > ZONE_DEVICE page is idle, we should also update e.g. > mm/swap.c:put_devmap_managed_page() or > mm/gup.c:__unpin_devmap_managed_user_page() (there may be more places like > this but I found at least these two...). Maybe Dan has more thoughts about > this. > > Honza I think this is a good point but I would like to make that a follow on patch rather than add to this one.