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 9CDC4EB64DA for ; Sat, 8 Jul 2023 04:40:54 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F3D3C8D0001; Sat, 8 Jul 2023 00:40:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EC80E6B0072; Sat, 8 Jul 2023 00:40:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CF1658D0001; Sat, 8 Jul 2023 00:40:53 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id B99AA6B0071 for ; Sat, 8 Jul 2023 00:40:53 -0400 (EDT) Received: from smtpin28.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 841FB1201A1 for ; Sat, 8 Jul 2023 04:40:53 +0000 (UTC) X-FDA: 80987194386.28.0F11432 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by imf18.hostedemail.com (Postfix) with ESMTP id CF8E11C0006 for ; Sat, 8 Jul 2023 04:40:49 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=WjRXr2WL; dmarc=pass (policy=none) header.from=intel.com; arc=reject ("signature check failed: fail, {[1] = sig:microsoft.com:reject}"); spf=pass (imf18.hostedemail.com: domain of fengwei.yin@intel.com designates 134.134.136.20 as permitted sender) smtp.mailfrom=fengwei.yin@intel.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1688791250; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=dRXe/HzCoBBxP+NVQQqpJzEdNkNRZaisxakUOJ8vRgc=; b=8FkwDVaUVc9k5ZV8g8dNZKUOC3OY0BR+CIyBmwxjjCL5yJdy3O70HAKn2zQjr/ifO0fVMI xMQ27wMR8DeiThA3R/KUy8A2kWA+EsOvd6cPNDO40UI7tRpEpMCkm/hJdfJN2uWsKjcw/s egtjWqXO2qt6qXFQPdhz1L0kdly6mvs= ARC-Authentication-Results: i=2; imf18.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=WjRXr2WL; dmarc=pass (policy=none) header.from=intel.com; arc=reject ("signature check failed: fail, {[1] = sig:microsoft.com:reject}"); spf=pass (imf18.hostedemail.com: domain of fengwei.yin@intel.com designates 134.134.136.20 as permitted sender) smtp.mailfrom=fengwei.yin@intel.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1688791250; a=rsa-sha256; cv=fail; b=Q5KRf/dtx2bCeoZVkfwznQP0H5T75cUz4CFxwtiqRcl7svWs0DlI2k0yp7DGFxfKHEtm97 VPFEK4RKMfXzWCDFPzLOs6CK2nZB9iMa+lh+yUfWEN4NOsz6EL4O8sdX4AJTw1wHsliPFY o9Ib3cxLb7Bnm1nCKh43bRjL8CVbDTI= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1688791250; x=1720327250; h=message-id:date:subject:to:cc:references:from: in-reply-to:content-transfer-encoding:mime-version; bh=Yr7z1v8z0AyQzlY/1+TnGDBLiYl62xFX8A6qZpphJfA=; b=WjRXr2WLXR798fUisllcPxjbx2LKHXK8gKULCC+Bm+etp/QjXKo20RZH bBWz9T76opSLoNxmchaPhehB8eDixX9IGtZXeJ8xpxL80Ju4ziLAug+xG NGkapXN96WfrxHMwHWqp9hkAUqA4PT4uSMKhVN6PSjWyzsRRcIwej03qJ wsN4Lg1N0pAbOCVNiPyMLGDeSgb1tIjzz3z//sYBTpETYM+v4VsJmOZkf RiFl9h1EWqFf2EyS+U53VbTzLuwpjnSTHzQcuLQ0B7/O6OzoeOZhJ/MtZ LNruTemWb4Yt0um3r3TD6Ri8wVQX0p9YDpV/Cb+lxhUNpeohDG9wROExN w==; X-IronPort-AV: E=McAfee;i="6600,9927,10764"; a="353882911" X-IronPort-AV: E=Sophos;i="6.01,189,1684825200"; d="scan'208";a="353882911" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jul 2023 21:40:48 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10764"; a="894202195" X-IronPort-AV: E=Sophos;i="6.01,189,1684825200"; d="scan'208";a="894202195" Received: from fmsmsx603.amr.corp.intel.com ([10.18.126.83]) by orsmga005.jf.intel.com with ESMTP; 07 Jul 2023 21:40:47 -0700 Received: from fmsmsx610.amr.corp.intel.com (10.18.126.90) by fmsmsx603.amr.corp.intel.com (10.18.126.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Fri, 7 Jul 2023 21:40:47 -0700 Received: from fmsedg602.ED.cps.intel.com (10.1.192.136) by fmsmsx610.amr.corp.intel.com (10.18.126.90) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27 via Frontend Transport; Fri, 7 Jul 2023 21:40:47 -0700 Received: from NAM02-BN1-obe.outbound.protection.outlook.com (104.47.51.49) by edgegateway.intel.com (192.55.55.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.27; Fri, 7 Jul 2023 21:40:47 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=A24FR31LtJu1sFye06K72OLUfEJMLg+b5FeW0isgZnBgwZhnmtwyHPOhW2NBfMdyVtjZHLTpH9MCrI29LQILtzm5DIvIMUayn3uTt4sO7W2qaNi+UkoSfYzJiVp3kyj5QYP2zIVJyfUfsIZk+n4bf8mngqcBXjI5r6SgiLJMrVvFgRmDyLDpJ615r2E1wKPhNz9XcSFAoAWVQ1XnPcjMaHwlBjrjR1hp4+CbNGZvBzvl12cN9AVxj7BYfDa0l9SMlT0Krkhry5nrsbEAAN/klqIEb0vTJON5X2SsE/J8fDSH6VqeY+y9tbGknNLzxI82P+6gqrw9MHfLws+O6mLn9Q== 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=dRXe/HzCoBBxP+NVQQqpJzEdNkNRZaisxakUOJ8vRgc=; b=E6AbNXInZh9EtOQd4CLhKzJNB0Ac6duTV49z+9qZzd2FusiNpX3ja2od/v7TxnNcH9AKT8DV0KcpBNhZItXhS5g5iyDD5CTPM94jBRz3lOIzx7P2DxnJAazoEt/B8JxhZyK5oqXdtrD/gNCidGjLSqgTC3wX7WUhXMNsYHjZovQbEU3JPq9v89+izgIyR0i1FljH8XF4UEL+5TUwTqyuzi5Vuoi95ERls9H+zM4xQTSLmgB22VkDI4N+ppUY2SYxLgS/586SozfJlcvOd7u3dgDDgMrONkEcgXIMphkyLmhDr9H5nfPJJMO1ZaYQmnkbRV1u0Kdw5BiQ89IKbtfa4g== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Received: from CO1PR11MB4820.namprd11.prod.outlook.com (2603:10b6:303:6f::8) by PH0PR11MB7470.namprd11.prod.outlook.com (2603:10b6:510:288::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6565.26; Sat, 8 Jul 2023 04:40:45 +0000 Received: from CO1PR11MB4820.namprd11.prod.outlook.com ([fe80::e6c7:a86d:68d6:f2f3]) by CO1PR11MB4820.namprd11.prod.outlook.com ([fe80::e6c7:a86d:68d6:f2f3%5]) with mapi id 15.20.6565.026; Sat, 8 Jul 2023 04:40:45 +0000 Message-ID: <0e3a7331-bf91-5d3b-0f05-634f1cbb60d5@intel.com> Date: Sat, 8 Jul 2023 12:40:36 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.12.0 Subject: Re: [RFC PATCH 0/3] support large folio for mlock Content-Language: en-US To: Yu Zhao , Matthew Wilcox CC: David Hildenbrand , , , , , References: <20230707165221.4076590-1-fengwei.yin@intel.com> <4bb39d6e-a324-0d85-7d44-8e8a37a1cfec@redhat.com> <436cd29f-44a6-7636-5015-377051942137@intel.com> From: "Yin, Fengwei" In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: SG2PR03CA0107.apcprd03.prod.outlook.com (2603:1096:4:7c::35) To CO1PR11MB4820.namprd11.prod.outlook.com (2603:10b6:303:6f::8) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CO1PR11MB4820:EE_|PH0PR11MB7470:EE_ X-MS-Office365-Filtering-Correlation-Id: ef8c31c6-62b0-4df7-ece9-08db7f6d7e3e 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:CO1PR11MB4820.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230028)(396003)(136003)(39860400002)(366004)(376002)(346002)(451199021)(31686004)(66899021)(6486002)(478600001)(6666004)(110136005)(2616005)(83380400001)(36756003)(86362001)(31696002)(2906002)(6506007)(26005)(53546011)(186003)(6512007)(38100700002)(82960400001)(66946007)(66556008)(66476007)(4326008)(316002)(41300700001)(5660300002)(8936002)(8676002)(45980500001)(43740500002);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?RE90WkYvMU13RXhVTzUxQ3BUekUwWDR0NE1kZ0REdUlXOHNIWTdlQWRRNXNp?= =?utf-8?B?VUtUQnVXNStRWmw4TUUyT29TSVptNHRxK09vRHRtVnVwa0s3YUFKbDVLOVdD?= =?utf-8?B?MlAwN1VDMmpORjlid1NGTFhPMWVYRXRVK0ZXL3dzOGsyNG9uVTRCc0ZDeGht?= =?utf-8?B?NG9oNG9iSktGWUYyMVlOL012S2VsQkZZSXh4ZFUvdDFiTnZBOEIxdkpaTzRB?= =?utf-8?B?dGowODVMcnoyYTZ6ek4rVU9IckZrSVp5cDFqSjFGVGR0RG0rZFJRM0JEek1W?= =?utf-8?B?RWpWVVZaVDVpc05BSW91OXF6S1Z2UmtLc1dZY2R0VlFhL0JqS3JVWG5EUXdk?= =?utf-8?B?Slh2NHp4WXlYSUxWS0l2ZmN3RE93dTZQOEdob0RuVzdSS2I3dDdvREFmQzBX?= =?utf-8?B?T0hCdnMzQTlCSVJaSVdMSSszOFVPRGRMYXc4SDRqWVJZcjlOUXVWVHd0SVRo?= =?utf-8?B?VDhXY09kbVErdldWRm5pQ253TU5vejNocEVVdU5ydE1MVzFkbVNVYUtETmJt?= =?utf-8?B?TE9wL0JIZTd6Vy9qbkU0YzNtWEdJUEFGTGtobG85ajMweE5sZTNrTkU4N1Rk?= =?utf-8?B?d1QwRTEwK0l3UGk0MmRIZ1lQaml2dSsxRHYzTGJjTmp1MC8xVCtZcXBBcVFr?= =?utf-8?B?OWtETHY5enBqWnJYcjB1cENxQzRnL0wxemZUdCs3UkdMMndidEhGdGc1bXl1?= =?utf-8?B?dG5Fd3RPdXJYQ2RzNVZoMWhCeTNlVlFzMGdmWWhGTkp5ZENaaWM3TWp1VEJE?= =?utf-8?B?eXpnM1d2dVdldzIxa29QRGhlN3BlN1ZmWmYrMm9oUTh3b2RjbFFzMm9NSUhy?= =?utf-8?B?Z0RaeEtRZ3N5UlhZVXpIQU82RW84TlRKeFVIUzd6VDlITTQ1SHVjZFNYY092?= =?utf-8?B?b0lxRDdtb0k2UkdlN3JNNWRtdm5qNW1GQlorOWFiMER1cTR2NEs2SDllZlVl?= =?utf-8?B?QzFNbHpaVkpaTXRYa2wvRDJyN3V0b1hhR3piWGNIakdCMks5WHNsWjR6dGF5?= =?utf-8?B?clJ5Z09lZVhMSFFYeXdHYzlrd1hKU3RPZWU1anZiM1gwYjVjS2tVR09JS25D?= =?utf-8?B?SWdZQ2ZPQlU1dVJ6UUZKWHZCdnlrUDdNN2Z0b1BkWWV4RUt2Z0Z1ZlpEV2ZB?= =?utf-8?B?MmRvMVNHQnc2UHJGK1Nub1NOWkpmWlh3cUdLSUFoMUF4cTJiMnIxRXk5eHNK?= =?utf-8?B?TkpPMUVMSzJTL2p1eUhKVnRNT2o0RWFQdllkdVdDUXA1azdiNUxRbzVvNjFt?= =?utf-8?B?eDUxRTNaL2FadFBBZTFSSTZiUmswcHR4bi9mMERDYlkvL0cvenJ4UzVZZGhw?= =?utf-8?B?SVVaOTF5ajFyOTdpeWY4MHYyc2FsSEsvRmJqSlhLM0ZnUEd5QTBtbVB4UDdJ?= =?utf-8?B?d3lLMTRUTUVxMzlyL2xGQUVucEF4RGl3YUxJVXNUUzBENk90VVQvdTM2b2xp?= =?utf-8?B?L2JFVFUzemFUcm12Uk1Zd2p3TFBPaXdKb2xjRldRaVBRdnpMeGd0SzdkYmc5?= =?utf-8?B?Ry9RUTg2aEpXQldJcGNzTkRpd0ZVakNvd2lRRTA2WXRQR0VNcTJ1eG5uYnNt?= =?utf-8?B?RnFnVmJLWXE2bFhWdFE5QjNmazE2c3NnL0Nqd05GWGx3bW0yb0ZTbmh4cjY2?= =?utf-8?B?MUh0SFh2dFFiUUdUT214bmxyOVlMOG1WT0hjdU5oRVRPRTN3VTAwMEVFeEdx?= =?utf-8?B?THRtWGxYSk5YNjZQSW5iaFlTMEVsRy9zdnQxelREeEYvYysvREwzWDFRNjVq?= =?utf-8?B?VTB5R3BLTE5TSFZaby9lTVRuVXlSRGh2Zk5HYW5UT0ZsdTlCVEFsR3Z5ZmlG?= =?utf-8?B?WnlKYURQU05OSjJ0SlZJNldHelRrNEhRcHQrR01OMU8zQXdBSzBZd0U2dEt4?= =?utf-8?B?SEpmQzcvNERQL3BidlVvU21RbWhOMEVUVHRrMkwxR085eC9jUEMvSk9hb3o1?= =?utf-8?B?WUp1TllXT3JBdkswbWI2WXYxT29xZkxnU0wxK240V3poMy9PS1RwTzhjL2VN?= =?utf-8?B?V0JNN29vZVQwRXdwZnYyTWFzT05UKzNEalhjazFlckcwNmo4aDNZeDdzSWpY?= =?utf-8?B?cWgvWEp6MlZjMHlnN2RkZUdpU3BzODlwK1ZmanRIVTVOc2xwYmkySCtxeDBx?= =?utf-8?B?ZldVZGhwWjl5c2VKT2NPVGVUay85eEZmWjlJRFdUWmkvbHRRN3hzY1hnSFhm?= =?utf-8?B?UEE9PQ==?= X-MS-Exchange-CrossTenant-Network-Message-Id: ef8c31c6-62b0-4df7-ece9-08db7f6d7e3e X-MS-Exchange-CrossTenant-AuthSource: CO1PR11MB4820.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jul 2023 04:40:45.0158 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 04xV+TokRqOaQGACw4ynftWa3rW4zxlCzDmWa2HOV4Bp2Ew0Gssa/iTjDrNNBTRQlTXGm2Yk02NhkjvGi6BrPQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH0PR11MB7470 X-OriginatorOrg: intel.com X-Rspamd-Queue-Id: CF8E11C0006 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: dh3atuzbkytam4h5oqk9kypyna11qejk X-HE-Tag: 1688791249-257524 X-HE-Meta: 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 EaKVkWr7 TZ1kUkMO0jpFuYHm92KG4konxXkYUvtd5lz6RKNkVZ0wPvDnKuVm9bEKA+8zI/eQiS9K/cjsDgKsHqZ5HrV1Hlh0jMBKDcSnK/8e7CJqy1IPrsXHZ49WuTLYmn6iKkN2tEmOtWpbf5aokMsjUTO3gjkzmVIsI0a3DCpQx5siDxmeXfkRwC49dacRjI0b2uY3h/54MRFk/ZZq8q3M3VCJkpS6UqPRTcc1yFWP7usopro9TwHOiik9ekgfkfhJOCsuWzEUIsTt3655ejhBP99hlncOP31QZaebgnsGfWFhW5901V1FU3jKCZejq/J3bNfXWqaUyE14FJ8uMvJ8EwLLoCtFhzA== 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 7/8/2023 12:35 PM, Yu Zhao wrote: > On Fri, Jul 7, 2023 at 10:02 PM Matthew Wilcox wrote: >> >> On Sat, Jul 08, 2023 at 11:52:23AM +0800, Yin, Fengwei wrote: >>>> Oh, I agree, there are always going to be circumstances where we realise >>>> we've made a bad decision and can't (easily) undo it. Unless we have a >>>> per-page pincount, and I Would Rather Not Do That. But we should _try_ >>>> to do that because it's the right model -- that's what I meant by "Tell >>>> me why I'm wrong"; what scenarios do we have where a user temporarilly >>>> mlocks (or mprotects or ...) a range of memory, but wants that memory >>>> to be aged in the LRU exactly the same way as the adjacent memory that >>>> wasn't mprotected? >>> for manpage of mlock(): >>> mlock(), mlock2(), and mlockall() lock part or all of the calling process's virtual address space into RAM, preventing that memory >>> from being paged to the swap area. >>> >>> So my understanding is it's OK to let the memory mlocked to be aged with >>> the adjacent memory which is not mlocked. Just make sure they are not >>> paged out to swap. >> >> Right, it doesn't break anything; it's just a similar problem to >> internal fragmentation. The pages of the folio which aren't mlocked >> will also be locked in RAM and never paged out. > > I don't think this is the case: since partially locking a > non-pmd-mappable large folio is a nop, it remains on one of the > evictable LRUs. The rmap walk by folio_referenced() should already be > able to find the VMA and the PTEs mapping the unlocked portion. So the > page reclaim should be able to correctly age the unlocked portion even > though the folio contains a locked portion too. And when it tries to > reclaim the entire folio, it first tries to split it into a list of > base folios in shrink_folio_list(), and if that succeeds, it walks the > rmap of each base folio on that list to unmap (not age). Unmapping > doesn't have TTU_IGNORE_MLOCK, so it should correctly call > mlock_vma_folio() on the locked base folios and bail out. And finally > those locked base folios are put back to the unevictable list. Yes. This is exact my understanding to this too. It's also why this patchset keep large folio cross VMA boundary munlocked. Regards Yin, Fengwei > >>> One question for implementation detail: >>> If the large folio cross VMA boundary can not be split, how do we >>> deal with this case? Retry in syscall till it's split successfully? >>> Or return error (and what ERRORS should we choose) to user space? >> >> I would be tempted to allocate memory & copy to the new mlocked VMA. >> The old folio will go on the deferred_list and be split later, or its >> valid parts will be written to swap and then it can be freed.