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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3FC4BC433EF for ; Fri, 1 Apr 2022 20:09:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BEE146B0071; Fri, 1 Apr 2022 16:08:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B9C168D0002; Fri, 1 Apr 2022 16:08:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9C8AE8D0001; Fri, 1 Apr 2022 16:08:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0009.hostedemail.com [216.40.44.9]) by kanga.kvack.org (Postfix) with ESMTP id 8ED996B0071 for ; Fri, 1 Apr 2022 16:08:50 -0400 (EDT) Received: from smtpin31.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 59EBCA8698 for ; Fri, 1 Apr 2022 20:08:40 +0000 (UTC) X-FDA: 79309398000.31.A137BA8 Received: from NAM02-SN1-obe.outbound.protection.outlook.com (mail-sn1anam02on2079.outbound.protection.outlook.com [40.107.96.79]) by imf21.hostedemail.com (Postfix) with ESMTP id 6CA4D1C001B for ; Fri, 1 Apr 2022 20:08:39 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=B7NuSIqWSDYaONOH63kOKjr/j0dYmWixNttt7ZszJ39r/2b+OksVmPFudnIZuOuPOB82r6WNdoMwqcjgOHeay/uqmZMNQHulVuBDLdo5y/ntiXKX05XCmlazYe7+AktDyNyECiRB4tgAozdl/KSxb8Dli2TLZedHJ9xdWD89QSIU2d7dM5AkqWcj75A/z8eS8xnEbDwPmKBBIZAf16Mou4ULhAbC8FMRMa620ZtaPK+KzPSaLOI1R4NMKE4oIZ8CjYi5uAHzKnOXVEogYZVFzVh8UmlynkiZ+hEsKMmSeCclZjsRV7SywC3AfcSc2EafkSkgsmMoHYrBZb6EjD++rg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=3EF+Q2R2VRE6MXe5yV5yQEaHL1L1UKjIEwysxrHJ7hY=; b=i5EiPvZ0nuconhGUYIZup4LuZ8rZ7z5HlWM20L2ljg/UbKB0lEVp9TwOiA4VXzoZUygGCQOmfM8hDU6zO77xZB0RoXxg0raAS6aulyn5CE1etQxNwX1fXYkICSzuIZVHfK8doqLd31+16YZSiTMwGex352ycMWn2p/JCysCvznzf9ViQlh0xZVuFTynqjXIhWRMgHYRgRQbt79Cc5IV/m1F5OR+f0t5U7Z7X80ZZCeMZmZvlgqDueSp+CFt1ui7pvY4Iqu2ytboj8n6N6usqs9wkUfcMESH4TvccdC/cHUut0g70n8Ik0NAODaJctpIeDst0y6hiBjvVmJjgLnyGkA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=3EF+Q2R2VRE6MXe5yV5yQEaHL1L1UKjIEwysxrHJ7hY=; b=dQ1t9/L8zY3Mbn/Gsl/fCezo3KM9Yn6AbPauh2eJlQ395hB5jr1U2N4LM58tRDmCEIyCdQe+acWw6KjODyg2Ng2Od3S5azM/ShPhSOiV1TL6YgEKuXyyPhTB4MpUhCdNpv22yrZJnykkPTvemINs0d6NVC43RiatQFF0CIPDIxE= Received: from BN9PR12MB5115.namprd12.prod.outlook.com (2603:10b6:408:118::14) by BN8PR12MB2929.namprd12.prod.outlook.com (2603:10b6:408:9c::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5123.26; Fri, 1 Apr 2022 20:08:37 +0000 Received: from BN9PR12MB5115.namprd12.prod.outlook.com ([fe80::4839:9431:1040:5cd5]) by BN9PR12MB5115.namprd12.prod.outlook.com ([fe80::4839:9431:1040:5cd5%3]) with mapi id 15.20.5123.026; Fri, 1 Apr 2022 20:08:36 +0000 Message-ID: <82ed845d-2534-490c-f9b9-a875e0283cc9@amd.com> Date: Fri, 1 Apr 2022 16:08:35 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH v2 1/3] mm: add vm_normal_lru_pages for LRU handled pages only Content-Language: en-US To: Christoph Hellwig , Alex Sierra Cc: jgg@nvidia.com, david@redhat.com, linux-mm@kvack.org, rcampbell@nvidia.com, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, jglisse@redhat.com, apopple@nvidia.com, willy@infradead.org, akpm@linux-foundation.org References: <20220330212537.12186-1-alex.sierra@amd.com> <20220330212537.12186-2-alex.sierra@amd.com> <20220331085341.GA22102@lst.de> From: Felix Kuehling Organization: AMD Inc. In-Reply-To: <20220331085341.GA22102@lst.de> Content-Type: text/plain; charset=UTF-8; format=flowed X-ClientProxiedBy: MN2PR17CA0032.namprd17.prod.outlook.com (2603:10b6:208:15e::45) To BN9PR12MB5115.namprd12.prod.outlook.com (2603:10b6:408:118::14) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 102534fd-ee60-456f-de85-08da141b67f2 X-MS-TrafficTypeDiagnostic: BN8PR12MB2929:EE_ X-Microsoft-Antispam-PRVS: X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BN9PR12MB5115.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230001)(4636009)(366004)(53546011)(8936002)(36756003)(2906002)(7416002)(26005)(36916002)(186003)(31686004)(2616005)(6512007)(6506007)(508600001)(38100700002)(110136005)(316002)(6636002)(31696002)(86362001)(66946007)(4326008)(66476007)(5660300002)(44832011)(8676002)(66556008)(6486002)(43740500002)(45980500001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?NTJ0MkYweHNDV3F5L1JjZkh4QmR3c3ZrbDlhbUtJbGI5RlR0K3c4RU1jV2ls?= =?utf-8?B?UDFzM0ZCNFM1UlpPNk9yRkg3VWQ5NTNNK0RydEYzWFpqZmxINWs5dEFKMDlS?= =?utf-8?B?S1NPdjk1cCs5Snk4dDRNZk1JamltMVNHeTN3WmE5dmorUkNFR2drVHpyOVVt?= =?utf-8?B?Qmlka0RyU29YRlFkTE1yandRS0xEb3RxTFJnWmFpSDhqUmN3VHlXbG9Sb1kr?= =?utf-8?B?ZzhEWlEyemlpeTdYMjVtd2xhS0NpZGZNTkZPNDZBQlFKT0liQnp6aGRyVWdZ?= =?utf-8?B?bDQ4OEVjSGxUN0NiOGhGeVdFYk05QzNjOW9LRTNOcXVzQUVSNlV4NjFyYkVr?= =?utf-8?B?K3JzeExqZVllN0JMQ1pKRjZLMW5GNW9Od0hWWVBqRmFKRHhSUzJRdDMxMmMw?= =?utf-8?B?VlhzMk15anl6elRSakdoeGVsaWI0ajM2cUx2d3NQZERNbm80THdRekE4UVFO?= =?utf-8?B?OW84bFlsV1hPU1ViUGZXVmlSNURnb0tNdTVBZTZyZ1FqSWNvQm51b2pJL1h5?= =?utf-8?B?ZWY4bFRXWTkva1F4dzRzdmtWcFRpQ2dxUkJiTEpqaFdTeThMbU9nVGd1aFRh?= =?utf-8?B?RG5nK0JDbGh5WXpGR1AybXVhZ0Vrd3VWUGUwYzlxR0I1SG5aMEJGaE1pYWZS?= =?utf-8?B?S2JrbzhIWU8rUk04TnpuTUMwdEFvM3YvZ0Y1ZEljNThqNDJmK0VQTks4NFBH?= =?utf-8?B?STRpZzYwdUlJZ0FkbXh0Wk9paFhxQW9ZbjVJSmVkVDZXWlBpSnNOeTlzYUUz?= =?utf-8?B?QWJITVFwb29oNDFscG1YZUJGZzArQmhacEpTVC9RdXNZbFRkMStTT3RKbFRn?= =?utf-8?B?clRxWHBTZ0h1NVUvOWxpSUNGNnBZZXJkZWRjTEJPYWNRSjRHV1pjWjdIN3h5?= =?utf-8?B?TW9mcm1QSDdNaVRVV1lVL21RNTdSQk5EQ0szRXpQb2lXd01rNnRyZ2Jvc1JC?= =?utf-8?B?QTFDS0w5MjlCSkN3VUNiM08wYmhZdVA2aEorMDh6UEFxbG9oZWJGZjFOWG9G?= =?utf-8?B?WUdJb3JScTMrYTAwMlZTc1FiNWhUVVkrMS96cjMxclNSaVZtQmR2S0N0M3Fk?= =?utf-8?B?UWNVaVV3NkkvRVdxYTM0MGVVOFI1RmFucTd1UDVmQkJHenArSkR6aDNxL3Bw?= =?utf-8?B?M1QvOHU2SDQzczhmWWRMUUlad0ZSUW9SOTZFNmdRemVQVW40ODFJMlF2YkE5?= =?utf-8?B?UFlJeTU3RGpoSnlMclR3eFBwTUlTMUJwSkM5eTdwYU0wZ2x0UzNxaXQ1QUs1?= =?utf-8?B?R09KbkNXWEI5ZGhLRGVyTUpoMEVqdzB6Y3V3WnM0WXZqMEhZOWcvMnlnTlN0?= =?utf-8?B?RlV6YjB4dlhQbVltNTR4UHJCeEZwUFRxWTFBOFVIVTJpWS9YUXdSVUV4MFd1?= =?utf-8?B?UmlRQ0NKZ3ZYakFVM0hVRnNIak9JTE1qVlBtZGxsZklPd1hJVWlUTFJUcFZW?= =?utf-8?B?VERHZjdscHZUQXQzaHNLWHdOdUkzQXo4bUttcXpKdU9vQjZva1ZpZnBVTEFY?= =?utf-8?B?V1M3WnVVd0Z1dlJHdUMyUHUzMVVuTTNWcVFtZkN0K2xDbHJHdytBSmNHODZN?= =?utf-8?B?V2JKa25kV0F2NVFvZnJmTWxJdXBTRllYKy9DT3ozSGRkUmFrbC82c3RmcTJv?= =?utf-8?B?akVDK3ByRExkVDNwVHBSU0NnUzdwaWptdVI3SG9uQUZyNk9FNGN1eWNkZjZ6?= =?utf-8?B?UGVVc2lSa1hWUFdRTjhBWHdicDRONk5rMGZWSmliOVpDZzhJOGpyMHo4WnpQ?= =?utf-8?B?RDFIL0kwREdmaUhISit4ZE8zN3JMT3VOeENFbmg1UEViQzFsWnBLRWRMY1U5?= =?utf-8?B?T2JuUkxFMmIrNGhBaGh5MXJZTE9HVUlOSHNVVnZGQmJsWmk2S2kzTWdnbUMv?= =?utf-8?B?NDN5TnBuTXIxcE9ZaVhvM01TaGdzRmVJUlA4QVBTYitYamdXdXhBVGVaZzYz?= =?utf-8?B?UktKQ2RGQTdjRUdkVVZYK3BISjdRbExnb3JldGkzaE9ZWXFYN3dNNzRaZHRT?= =?utf-8?B?TVRFblRSV0VLYzIwbGNkWHR5ZnlLR0w1ZnNRTDVHWFVhdnM1MmZIbncrbS9i?= =?utf-8?B?TnN2TFRnTDdvSmt0WUwwQ0FvS0h4Skt2ZVJyWXgvdStXUXVreExVVmRHQ29B?= =?utf-8?B?dEpSUmJOZEJwZ3c2UjhWeStta2ZOVTJWeDBKOXhFUnE3L0V0QkpDVjFmVmxj?= =?utf-8?B?T3JGeU5rcVlmVFlkUlpQUlZUMXBtbWRtR0pnYnZ3K0lTZ3Fpdk1kWDNVdDBJ?= =?utf-8?B?UTJnRkR6LzVXcHBGWnZsMVQwWnNJNHB2RTNJd0J3RVc5ckhKT1k2SmYwLzBj?= =?utf-8?B?M0FFMXFQejJMcDNxT1o1bmFaY21Pck1HMEZISzhIUzFsUGJLZUtKZz09?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 102534fd-ee60-456f-de85-08da141b67f2 X-MS-Exchange-CrossTenant-AuthSource: BN9PR12MB5115.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 01 Apr 2022 20:08:36.9019 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: tgg9i3FXs7OVQZRpagmfav/jVdJhxfdMXZ0Lzw1pzFR9DGk1PlIApNS5TuwI71ExHTpRNg3Uo8WUqDr97Z4w3Q== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN8PR12MB2929 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 6CA4D1C001B X-Stat-Signature: njfgz7wjdo6ycpjbuq5yrarmgtbhd7t4 Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=amd.com header.s=selector1 header.b="dQ1t9/L8"; dmarc=pass (policy=quarantine) header.from=amd.com; spf=pass (imf21.hostedemail.com: domain of Felix.Kuehling@amd.com designates 40.107.96.79 as permitted sender) smtp.mailfrom=Felix.Kuehling@amd.com X-Rspam-User: X-HE-Tag: 1648843719-173890 Content-Transfer-Encoding: quoted-printable 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 2022-03-31 04:53, Christoph Hellwig wrote: >> - page =3D vm_normal_page(vma, addr, pte); >> + page =3D vm_normal_lru_page(vma, addr, pte); > Why can't this deal with ZONE_DEVICE pages? It certainly has > nothing do with a LRU I think. In fact being able to have > stats that count say the number of device pages here would > probably be useful at some point. Maybe at some point. However, this is in a function called=20 "can_gather_numa_stats". There are no meaningful NUMA stats for device=20 pages. I agree that the name "vm_normal_lru_page" is not optimal in this=20 case. > > In general I find the vm_normal_lru_page vs vm_normal_page > API highly confusing. An explicit check for zone device pages > in the dozen or so spots that care has a much better documentation > value, especially if accompanied by comments where it isn't entirely > obvious. OK. We can do that. It would solve the function naming problem, and we'd=20 have more visibility of device page handling in more places in the=20 kernel, which has educational value. Regards, =C2=A0 Felix > >> page =3D follow_page(vma, addr, >> - FOLL_GET | FOLL_MIGRATION | FOLL_REMOTE); >> + FOLL_GET | FOLL_MIGRATION | FOLL_REMOTE | FOLL_LRU); > Overly long line here. > >> +/* >> + * NOTE: Technically this should goto check_pfn label. However, page-= >_mapcount >> + * is never incremented for device pages that are mmap through DAX me= chanism >> + * using pmem driver mounted into ext4 filesystem. When these pages a= re unmap, >> + * zap_pte_range is called and vm_normal_page return a valid page wit= h >> + * page_mapcount() =3D 0, before page_remove_rmap is called. >> + */ > Please properly indent comments. > >> + * zone, as long as the pte's are present and vm_normal_lru_page() su= cceeds. These >> * pages also get pinned. > Another overly long line here.