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 0CA8CC5AE59 for ; Fri, 30 May 2025 02:35:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9BA0C6B0082; Thu, 29 May 2025 22:35:54 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 991476B0083; Thu, 29 May 2025 22:35:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 87FFB6B0085; Thu, 29 May 2025 22:35:54 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 636636B0082 for ; Thu, 29 May 2025 22:35:54 -0400 (EDT) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 02EDAEC56C for ; Fri, 30 May 2025 02:35:52 +0000 (UTC) X-FDA: 83498008986.24.1F4444A Received: from NAM12-DM6-obe.outbound.protection.outlook.com (mail-dm6nam12on2088.outbound.protection.outlook.com [40.107.243.88]) by imf13.hostedemail.com (Postfix) with ESMTP id 2DB4120003 for ; Fri, 30 May 2025 02:35:49 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=dezfgUX8; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf13.hostedemail.com: domain of ziy@nvidia.com designates 40.107.243.88 as permitted sender) smtp.mailfrom=ziy@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1748572550; 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=vDqqvKJsxUybszXYVjAwCxa6AkikRdkAySZp6Q9Xdts=; b=j+/yYhZsRut7915WdwtHoCOaHToAmo5uC4IfiWpTBPMqkeQoRbInBl+NUX2YoMLC/C2IOn tp+VCyyJSuUnW8CEckSViuRt6mzWhHiZno9POEi4THIAmF60+UcxXWcUWg+dDaIZNJmQ+/ CXy9/HnnuErRDMa7iHqTdg+Lpcxj4UA= ARC-Authentication-Results: i=2; imf13.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=dezfgUX8; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf13.hostedemail.com: domain of ziy@nvidia.com designates 40.107.243.88 as permitted sender) smtp.mailfrom=ziy@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1748572550; a=rsa-sha256; cv=pass; b=qXy1yuEUZxRUVsYijM01ljJ29NoDhqr6JXx/fi0W9YderuqD5XQnQk1w4mJUZ0hpHG/3lj ZABiA7ufs9r+e9CInItWwbtq26ouVAXbPnjMjro6GSFSkDjGiKjk9Xlkow4U8ktCg3b69/ ZONSBK8HdHuBkZGBOy5loYub+RWXAUc= ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=ic7vyx15R+pB+GRjjAYGu7mYy7VGgCZACe8gjC5IKtJG/s5GzBZnVu1p1QehDjy31862dsSTcVmbnt30jO5TYSwXr0KEAvwSSKdf2t/1oWYRj+U3P5cnLhCKSjMv+8Q40gOm0gzK6KzxWPmPx9sSmFQGPIU/v1oXMtczlMBSAXxOUL3wn0pYZRFHEHtxmUnmVfKEf0cyEkGtwoiSFo2htiwUNQwnga5JD1ceuByEh6aHu/ScAxvPC/virdMxMrlNBYb0OnPKyA2zMsFtx8G6AJihKOBrZKzgZJNixdW6pqE0UUir8H98P41ulBaix+2+x0Yvdb1oqR61d7N4teHzxg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=vDqqvKJsxUybszXYVjAwCxa6AkikRdkAySZp6Q9Xdts=; b=LdxItmSwpPjTKdA2nUfq6TJn3acXMjiAB2XgqETl4djSPt3sKKQ1jSbrXbPZPWrq9AXmau3Xy3Le7mYfmaIHpUvvz84QRUx4Pp+i2qtgp7FvXza3fEpWrWoD+6fbFvGITVC+be2SqwI/8BJaDWq/Y+Q+O7rPK99HeKCmUYhkfw20akSNIely/gPMRJiH8jNIz4FrCGTQnVKbFfaz2TlG4RBOmAis9Dnw2rB7sta4qai7atWAEOySXS/QTYPsgWqwornPtCXVKMqyuGOe8R07QSMAXsJ3QKPzq+W28nhRsM4MBL9CUAYPxKd1XPz+dap2vgtSsbbUGs1i+puqCQrdYw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=vDqqvKJsxUybszXYVjAwCxa6AkikRdkAySZp6Q9Xdts=; b=dezfgUX8Bpz/SAUoh8OrBNWLbryfZCtveODbRMfLmhA6GsL6DiaPGJJoZxSDju6UYSrAmF2lD76LXUAdeULKqGdOIKc8VkpFeYDBoBAHvmRo9DlbJ/J27ksftSlcOMyYk+UFX9ILsOMk73YwuuIJS8uKvp061Gm1TFmc5E47u6BYJPYmnXk1XXfwepJ5A+eKCI8L/1x84+L+ci2CgDndDFLvQe2+kqyJx5yxNt3y5i3gUu44Lvv6R7bYowCk9eaHt2YDrtKGl/XhCZbxjwL42Bi+UMCWdI6JaIP1Q5Ysl0txqPghuFx/Pq/N22jPhHUSn7+4aOUmK11gNtm3GDTplA== Received: from DS7PR12MB9473.namprd12.prod.outlook.com (2603:10b6:8:252::5) by IA0PR12MB8086.namprd12.prod.outlook.com (2603:10b6:208:403::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8769.30; Fri, 30 May 2025 02:35:46 +0000 Received: from DS7PR12MB9473.namprd12.prod.outlook.com ([fe80::5189:ecec:d84a:133a]) by DS7PR12MB9473.namprd12.prod.outlook.com ([fe80::5189:ecec:d84a:133a%4]) with mapi id 15.20.8769.025; Fri, 30 May 2025 02:35:45 +0000 From: Zi Yan To: Baolin Wang Cc: akpm@linux-foundation.org, hughd@google.com, david@redhat.com, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] mm: shmem: disallow hugepages if the system-wide shmem THP sysfs settings are disabled Date: Thu, 29 May 2025 22:35:43 -0400 X-Mailer: MailMate (2.0r6255) Message-ID: <548AFF46-93AF-40CB-80E4-372DAAA9F80B@nvidia.com> In-Reply-To: <6132583a-1754-4eb1-9b84-19b55cac176c@linux.alibaba.com> References: <6132583a-1754-4eb1-9b84-19b55cac176c@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: BL0PR02CA0044.namprd02.prod.outlook.com (2603:10b6:207:3d::21) To DS7PR12MB9473.namprd12.prod.outlook.com (2603:10b6:8:252::5) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS7PR12MB9473:EE_|IA0PR12MB8086:EE_ X-MS-Office365-Filtering-Correlation-Id: 2a445a22-9f1e-474d-062e-08dd9f22ade9 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|7416014|376014|7053199007; X-Microsoft-Antispam-Message-Info: =?utf-8?B?SkRWRndPSlU1ZS9WeDNEL1RvY2o1QnAweERlTXFqcTI4Q1VJaVFoVEw1VVRz?= =?utf-8?B?WjFTWmRFckVRZGM4K09wMFhVTlFCMURoT1U4UG5PdkpkUHNneFQ3bDl0dGNV?= =?utf-8?B?NUFINGZoVUhacGxaNm1ORmR2azFoK1gwSWdXK0NxM01ycm9QQmtpZFlOYk40?= =?utf-8?B?aXQvdmVmL3BwOEZnajQ2eEhqWkNrTXYrVi9DTHk2cGZsZUQ3Z09HeGdFa1Rm?= =?utf-8?B?THNzQlV1Vk9BNC9tamdJUmd0ZUZpUlB0Y1dTTGxsRjBqSVI2c0hWUzZoeUdx?= =?utf-8?B?WUY0ejBQM3RHVzRQZnlNeiszWUFHaUZEQWozd1RrWVBIRG81K05ZNW9EVWRI?= =?utf-8?B?THlha2VjYWpOQllzTS9ocjRLU1lqY0kzYU9SZXZCVjFRaUoxZURvUjRibHZP?= =?utf-8?B?cUQ1eWU0U045YXUrWlkzTjR4a3ZuU0VpQjNpeG5oWTZmNXl2a2NpVUQrSGJu?= =?utf-8?B?RWd3Y2hsYmVyQklTbklFNkVqZHVOWHF5VVNQdUpUV2JxWWZpblozc3g3TXg4?= =?utf-8?B?NVdUekpyc05ueUtFYmpkVEZsdWZLcmVLYkU3dDJyUTlCL2RNZ2lIR1VWUWpa?= =?utf-8?B?Y1FDaXlkb2xNZWRRYWNqL1A1a2JjaHZobUhvaHM4aGhkK2Q4KzJNZ1NHTGlO?= =?utf-8?B?eXRTM3dscnlmakwvQXVpT204Nkl1ZzRPbHlqRE83bFJjZUIwS1BFb3VzRjEw?= =?utf-8?B?TUdBTXZyQmt5bDdFRlNFU3dJOWFQQmlOMDcraGxSZnFheTBuNnhDZ0ExRHlE?= =?utf-8?B?OWttZmRJbEJHT01SbXROWnNrTitrK2M2L2RvaTE0YTg4aWp4MjRKNEF6MTdn?= =?utf-8?B?STJMcTFFb1hnTkhUOTlMbmJFZ3E0dFVqNHl3ZDJ6ZzVBVEhHT0ZsQXhEcEdq?= =?utf-8?B?dmRkNW5SUW1tck1jbjlYa0JUTXpYdjNKUW1md3JyOTZoZmEzejFBcDJFVUxu?= =?utf-8?B?aTREUzRKaGNPTURGRTU0dytBYkg4ZVk2RjdWcXhLakVyNWo1c0xDaTBHZ01j?= =?utf-8?B?M1ova0o5Uk1uZC9CMmM1M1drU3RKQnVSQ1FZVW1Bd3UzU1QxcStMMEhjdDl1?= =?utf-8?B?cEhoRzZoa1lLRWxicmppR3cyUWsvNU8vbjczS2VxSlduN056SVM5Ykd1V2pR?= =?utf-8?B?TDIvbXhIV2FFZ2sva3dUZU4zS08rVThjeDVmMG1UeFREZmtqeFlINWVBdEox?= =?utf-8?B?bTFyMkJhL2ZtOGZUdDdYd3JkblJKd0JaR0N5QndDbXVsd01Md09mKzNOMHB2?= =?utf-8?B?c0l5SGh2aXcyd0VidEc3eVFtbnhxbUVzMWJJSVE0cS9RbDJzRXFKOVdHbzVW?= =?utf-8?B?STlJZ3d5VGJmZEJOQmpLNlFVWGxEYUFiVCtMQUlSZ3RFaDFNK0MzM2Z5MHJE?= =?utf-8?B?V2xxQWpDakd4SW1DdzZtK3hUOWhETU5MOWRhT1FCVFpoZHVtTnNSbEUrT1g5?= =?utf-8?B?b0NSUnlaeVk0RG04bkxPaEplc05ZcWQyaFlpYldVeTJPWGpJSHBHdVpZM1kr?= =?utf-8?B?djhhWm1oVUc1TzN2c25PV2Q2ZThZd3laaVRRUTNZWXUrempBYnUwQ2JsZ3Bu?= =?utf-8?B?VFdTOFdqenM5M1d1bnpWWXRsYU8ycklYQnh4STRINVNyNTBlTlNzZll5d2dz?= =?utf-8?B?cDMzSlFSVnlydmhoU1ZjbWp0SkNZb2JmNVk4MGJTSVZUSHNvMGZVcEk1clNi?= =?utf-8?B?cTk2Uzc5Nk5NcVBNZW5FdG43ZlNzNHg5NlduUXZUYjNia2xwNlpuOVIxTVJW?= =?utf-8?B?SXZzLzl3VVpjQ29pOU9UY3BUc1p6NzAxK01hd3p1aHlsWis3SDI5ZVlZSnNR?= =?utf-8?B?dzVNbG5JMDhkL2lsYnhxREhLZW9KVyt2N1lGWitzNzBXWEF1TVFYOWhVSDQx?= =?utf-8?B?ZHZETlRNM2dDTEhNVTRmYnRtK25XV1EwYnF2ZEdxUStDd004cnprVkpkcU9Z?= =?utf-8?Q?Z8jqie2wFfA=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS7PR12MB9473.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(7416014)(376014)(7053199007);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?Z05laExqNmpiTS9jRVhTUEJ5MStBL01GRjlwWGduYzRuekwvcHh6NmNBcDVZ?= =?utf-8?B?SC9HVkZhNjAyZFIwVkE5MGZ0N1ROSlI3UjYyTVdkNFQ3MkkwdityOVRJUC9t?= =?utf-8?B?RkEzTkpiNjB1amRDTFNoZHBHd1RQRFZzRkZ5bDIzL2VZa0FvU01mYTM1eEc5?= =?utf-8?B?d0RJbHFHVXFwMFZSZXE4RjNRU3QvcEd6RmZjRkdzWlEvck5KZXlrVzQ5eHpw?= =?utf-8?B?VTg2MDFnZzRmRENRU1JIVW1yVzM2QWNXMThUME14Ri9NTDUrY1ljdlhZMWZ3?= =?utf-8?B?MTdERE9MM1k2Y0FUanRzQU9NUXpFdTdtbzhpc2c5N01JdE1peHE3Q2xJV1RF?= =?utf-8?B?OEp1VndwYmkzVXRpclJkMXNTbFliR2s1UHU4cUMyaHdRQXlLWHdNMEVpWFJk?= =?utf-8?B?am1uUnpaei94djhGWW1xNFlwMHJ0RVY5S2ljOW5iUFFxUHdaU0M2T2VDMExk?= =?utf-8?B?U1drS0pDMC9EY0xlOGtHZE1JaGhJTTNGYVYyR3lXa0FZVWxGTFR4TE9iSHg3?= =?utf-8?B?VitqZTUyYnhQSk9QVEIzaFBHYzNLSTN1QzJTT1FWTW1ieXU1NnhqVlNxemFp?= =?utf-8?B?ejY3UlJKUzZwWWEzOTZvakhpMy9VV1NjNXlCdit5OVRzN0ZBdERLajl5L1p6?= =?utf-8?B?RnBoaEhaOU5SV3phUHdQRFMvOXk3ekRBU1U4aGxqbDVlcVVXNGdua2FxcC92?= =?utf-8?B?MW92Zk5qd3grQ1oxNkZsYkVXRGQ2dWpWRFEwWER6WVF3MUwzR0lKdC9mRUFi?= =?utf-8?B?YjlFZnlGSU40SHdZR2pNMGJpM3lURjRhajljcnJkb2pZWnl3d1JjdkFLVmNv?= =?utf-8?B?UlAzcGJSajdCUXMrdkpSejJDWWU2Z2lkZ1ZJa01tcUVycEM2b2h3b2Z6Snht?= =?utf-8?B?MlJ2cXFEVVlrMnZDM2VGZEY1UFlqd3BwWENPbHNQV1c4U2FqSC92Yjh1TlVX?= =?utf-8?B?ZldCalMrNTBxRGJUcENIYS84d09OVld6UGRmYXR6L25uK2dncERqOWFuOU9x?= =?utf-8?B?QWtCbzJiSmFzcWcyeHltVzcvVFJWakJVSnRtK0J2YnVPVGpLK0tRQkJCSzRp?= =?utf-8?B?YWZQY01HemU4WTBGdmFZNU5OT3FDRmR2Rm5QclpxRm45Sk85eHpWb2doZGFq?= =?utf-8?B?SHpEbjc5YkM5ZG1DQVVKdzgwQlAyN1JjazN4aFlFQklTZTdxRm8yWmV2SHBW?= =?utf-8?B?cEZuTjhLMldxU2gwTVdzbU12RDVNTU1lOFZRS3V1ZE00cmhBSWRuQXNrUEh1?= =?utf-8?B?VW1yODhSMk5iek9xVjZJNDdrM09wOEQ1TGg1U1pLNkJIWjlHVXU5ZmUzSUtu?= =?utf-8?B?VE9pTUoyaG5QSjZNdVlNMm42K3FDbUVOTU1OL2QwTUtDdy8vSEZsc1lSUzZz?= =?utf-8?B?Lyt1eDVWS3RLRmNwbHJoTGxUaXgwcnZjM3BuWUpyOUdZUTNxZnpBdXNpV2pq?= =?utf-8?B?Y0xHNzRYRW1YeTkvV0xXY0FOcEtkbW1lV3J2a2VYUnpZSHhxdmtkT0RrTitJ?= =?utf-8?B?VzVlT01YR0RaY2JtUEhseUN5ZjhjV05IRHJQcG9yczFnYlduRmZkbzRNcENC?= =?utf-8?B?MmpocnlEWDY3T2RkN1RDZVcxWGtLbXZETGI2Zlg0cmQvNHpWS2RheE1zQnR6?= =?utf-8?B?dXR0blZGMktDNTBaTVkvVjBkazlvVmxlWUQ4VTNuZlpJZzZsdlFzR1diMmlG?= =?utf-8?B?blQ3MlVsYy9IbnljUHFzNU9hckFxMUJZOER6ZU1VTzRlYyt1eEloTm9ab1Qw?= =?utf-8?B?Q1JxRzdMUU1veGNiR3JtQk9ocmtqTmpINi92eXhLWXhTVE9VMFpIeE5jZHRI?= =?utf-8?B?VHN4RExmcXZtazJ2RXpJSjRwNFV3ZTIxWHIvaThMd0JDTlFFTmg3dS92MllC?= =?utf-8?B?aWF1YVQ1ajd6djJkRVZHZkI0cUZza3ZIQnJ0VURtWlBVbi9QVnlmRlRSVmdW?= =?utf-8?B?bDMzZ2FIbEhvWm54NWNENE4rT1F2WU9iMTFMZnZkNFhWQ1RtU2ZvZzgzeGlK?= =?utf-8?B?VldCNHdCeGFEalhLQTdMU3FxVDFDSTJZZVNmK2VQSVVxUGxTN3VGL0duY0VR?= =?utf-8?B?K2RVejlYZW5kdVBVR1c3M1NxVlNLa3hGZzViY1lIcmVtM3ZYUEs2SWJWd3VB?= =?utf-8?Q?AFKLvKYHuZtZpbB+ox/SnEQ68?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 2a445a22-9f1e-474d-062e-08dd9f22ade9 X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB9473.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 May 2025 02:35:45.2922 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 4+DbfD8istRcAy6jT1id5uhoe/opRsgMaYWH9cdc5bqNmG3JRZUtjYOFgvPxp1h7 X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA0PR12MB8086 X-Rspamd-Queue-Id: 2DB4120003 X-Stat-Signature: 4rddiexdt7js6yxsm9px6nj78aknxrwi X-Rspam-User: X-Rspamd-Server: rspam07 X-HE-Tag: 1748572549-405278 X-HE-Meta: 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 KTGzlKS0 5qsqRk4zqUF6a4E+5HCJwgVNrqROYRQxIFPVtWLEn/u8OwL64rzZbxWftfDvsES9iu/YUshMjl4KGZC7TWvDN1T7pjke1F1IEJOdJjC2xXQYth8CZZbQg3ebfdYGTgpCjHyyWoNkEXPR2RQjwyEYwkreZ7iA5jjyp2s03cM280Zq8Ewl2xBrAS+mR/si82AaHH8y1zYtEDg0z2xIHuDklgz28SNWdHJRIR0Bgqqec8Lc7BHv7PhnQXsAlkJhYm9mL8yGDJN6eDEswakMGn5EZBL3Wecf82KlfrNHZ2g4Wb30a44tDh+djMupSAUciYym/uIREOsTxAXsK4fGaW1hnX+/v7aT22kT4ycRE2blw+NGW3nDPakq84ze6XfZV2e4swiejb6pfyJY1ykHJpBqgBDe+KEmhwKgUjgLHMhrWhThmOZ+ykByQyQMS7iK7Py6xm5PPoahjrlAKM5qljmHfbQb+Yg== 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: List-Subscribe: List-Unsubscribe: On 29 May 2025, at 22:32, Baolin Wang wrote: > On 2025/5/30 10:17, Zi Yan wrote: >> On 29 May 2025, at 21:58, Baolin Wang wrote: >> >>> On 2025/5/29 23:21, Zi Yan wrote: >>>> On 29 May 2025, at 4:23, Baolin Wang wrote: >>>> >>>>> The MADV_COLLAPSE will ignore the system-wide shmem THP sysfs setting= s, which >>>>> means that even though we have disabled the shmem THP configuration, = MADV_COLLAPSE >>>>> will still attempt to collapse into a shmem THP. This violates the ru= le we have >>>>> agreed upon: never means never. >>>>> >>>>> Then the current strategy is: >>>>> For shmem, if none of always, madvise, within_size, and inherit have = enabled >>>>> PMD-sized mTHP, then MADV_COLLAPSE will be prohibited from collapsing= PMD-sized mTHP. >>>>> >>>>> For tmpfs, if the mount option is set with the 'huge=3Dnever' paramet= er, then >>>>> MADV_COLLAPSE will be prohibited from collapsing PMD-sized mTHP. >>>>> >>>>> Signed-off-by: Baolin Wang >>>>> --- >>>>> mm/huge_memory.c | 2 +- >>>>> mm/shmem.c | 12 ++++++------ >>>>> 2 files changed, 7 insertions(+), 7 deletions(-) >>>>> >>>>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >>>>> index d3e66136e41a..a8cfa37cae72 100644 >>>>> --- a/mm/huge_memory.c >>>>> +++ b/mm/huge_memory.c >>>>> @@ -166,7 +166,7 @@ unsigned long __thp_vma_allowable_orders(struct v= m_area_struct *vma, >>>>> * own flags. >>>>> */ >>>>> if (!in_pf && shmem_file(vma->vm_file)) >>>>> - return shmem_allowable_huge_orders(file_inode(vma->vm_file), >>>>> + return orders & shmem_allowable_huge_orders(file_inode(vma->vm_fil= e), >>>>> vma, vma->vm_pgoff, 0, >>>>> !enforce_sysfs); >>>> >>>> OK, here orders is checked against allowed orders. >>>> >>>>> >>>>> diff --git a/mm/shmem.c b/mm/shmem.c >>>>> index 4b42419ce6b2..4dbb28d85cd9 100644 >>>>> --- a/mm/shmem.c >>>>> +++ b/mm/shmem.c >>>>> @@ -613,7 +613,7 @@ static unsigned int shmem_get_orders_within_size(= struct inode *inode, >>>>> } >>>>> >>>>> static unsigned int shmem_huge_global_enabled(struct inode *inode,= pgoff_t index, >>>>> - loff_t write_end, bool shmem_huge_force, >>>>> + loff_t write_end, >>>>> struct vm_area_struct *vma, >>>>> unsigned long vm_flags) >>>>> { >>>>> @@ -625,7 +625,7 @@ static unsigned int shmem_huge_global_enabled(str= uct inode *inode, pgoff_t index >>>>> return 0; >>>>> if (shmem_huge =3D=3D SHMEM_HUGE_DENY) >>>>> return 0; >>>>> - if (shmem_huge_force || shmem_huge =3D=3D SHMEM_HUGE_FORCE) >>>>> + if (shmem_huge =3D=3D SHMEM_HUGE_FORCE) >>>>> return maybe_pmd_order; >>>> >>>> shmem_huge is set by sysfs? >>> >>> Yes, through the '/sys/kernel/mm/transparent_hugepage/shmem_enabled' in= terface. >>> >>>>> /* >>>>> @@ -860,7 +860,7 @@ static unsigned long shmem_unused_huge_shrink(str= uct shmem_sb_info *sbinfo, >>>>> } >>>>> >>>>> static unsigned int shmem_huge_global_enabled(struct inode *inode,= pgoff_t index, >>>>> - loff_t write_end, bool shmem_huge_force, >>>>> + loff_t write_end, >>>>> struct vm_area_struct *vma, >>>>> unsigned long vm_flags) >>>>> { >>>>> @@ -1261,7 +1261,7 @@ static int shmem_getattr(struct mnt_idmap *idma= p, >>>>> STATX_ATTR_NODUMP); >>>>> generic_fillattr(idmap, request_mask, inode, stat); >>>>> >>>>> - if (shmem_huge_global_enabled(inode, 0, 0, false, NULL, 0)) >>>>> + if (shmem_huge_global_enabled(inode, 0, 0, NULL, 0)) >>>>> stat->blksize =3D HPAGE_PMD_SIZE; >>>>> >>>>> if (request_mask & STATX_BTIME) { >>>>> @@ -1768,7 +1768,7 @@ unsigned long shmem_allowable_huge_orders(struc= t inode *inode, >>>>> return 0; >>>>> >>>>> global_orders =3D shmem_huge_global_enabled(inode, index, write_e= nd, >>>>> - shmem_huge_force, vma, vm_flags); >>>>> + vma, vm_flags); >>>>> /* Tmpfs huge pages allocation */ >>>>> if (!vma || !vma_is_anon_shmem(vma)) >>>>> return global_orders; >>>>> @@ -1790,7 +1790,7 @@ unsigned long shmem_allowable_huge_orders(struc= t inode *inode, >>>>> /* Allow mTHP that will be fully within i_size. */ >>>>> mask |=3D shmem_get_orders_within_size(inode, within_size_orders,= index, 0); >>>>> >>>>> - if (vm_flags & VM_HUGEPAGE) >>>>> + if (shmem_huge_force || (vm_flags & VM_HUGEPAGE)) >>>>> mask |=3D READ_ONCE(huge_shmem_orders_madvise); >>>>> >>>>> if (global_orders > 0) >>>>> --=20 >>>>> 2.43.5 >>>> >>>> shmem_huge_force comes from !enforce_sysfs in __thp_vma_allowable_orde= rs(). >>>> Do you know when sysfs is not enforced and why? >>> >>> IIUC, shmem_huge_force will only be set during MADV_COLLAPSE. Originall= y, MADV_COLLAPSE was intended to ignore the system-wide THP sysfs settings.= However, if all system-wide shmem THP settings are disabled, we should not= allow MADV_COLLAPSE to collapse a THP. This is the issue this patchset aim= s to fix. Thanks for the review. >> >> Got it. If we want to enforce sysfs, why not just get rid of TVA_ENFORCE= _SYSFS >> and make everyone follow sysfs? > > Now MADV_COLLAPSE will ignore the VM_HUGEPAGE, while the others will chec= k the VM_HUGEPAGE flag before using 'huge_shmem_orders_madvise' with the TV= A_ENFORCE_SYSFS flag set. > > That is to follow the rule: =E2=80=9Callowing for collapsing in a VM with= out VM_HUGEPAGE in the "madvise" mode would be fine". Can you add this rule in your commit message? It clarifies things. > > So I think we should still keep the TVA_ENFORCE_SYSFS flag. Got it. Thank you for the explanation. Acked-by: Zi Yan Best Regards, Yan, Zi