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 0C9CCC61CE7 for ; Fri, 6 Jun 2025 18:07:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5F0D26B0088; Fri, 6 Jun 2025 14:07:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5A15B6B008C; Fri, 6 Jun 2025 14:07:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 442C06B0092; Fri, 6 Jun 2025 14:07:13 -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 1C90C6B0088 for ; Fri, 6 Jun 2025 14:07:13 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id C46B1BAA3E for ; Fri, 6 Jun 2025 18:07:12 +0000 (UTC) X-FDA: 83525757504.17.BF059D3 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by imf30.hostedemail.com (Postfix) with ESMTP id DD93E80014 for ; Fri, 6 Jun 2025 18:07:08 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=VHtLsUmL; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=oH9ZZRHA; spf=pass (imf30.hostedemail.com: domain of lorenzo.stoakes@oracle.com designates 205.220.177.32 as permitted sender) smtp.mailfrom=lorenzo.stoakes@oracle.com; dmarc=pass (policy=reject) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1749233229; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=84JJ+04JzOIjWxGcwJxz2D+8D5+GDqIahpvdf+qqPEw=; b=PArlIQbeyTzOc9jCTqOxUZ3M4mfpGFSE07ZtibRAfrFJkDrhn6iWW93RR8rdFLYr+ZFRfI ZWB0Zr3qBRUn/a+NIjf3CqWC6L97g50xOHJtgfEzMveZFlnKOUZDJM2/5XSsDJBsewbl1j wktOnW6ZfWK0TKHx5gcOc3Ou+6NZsMs= ARC-Authentication-Results: i=2; imf30.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=VHtLsUmL; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=oH9ZZRHA; spf=pass (imf30.hostedemail.com: domain of lorenzo.stoakes@oracle.com designates 205.220.177.32 as permitted sender) smtp.mailfrom=lorenzo.stoakes@oracle.com; dmarc=pass (policy=reject) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1749233229; a=rsa-sha256; cv=pass; b=hrpzkPL75fuy6EMmr0BIBav3dkevtYyV6yi5f2yTdDw1Ymz9TJu7/EMDYXVTUedbPu0G7E wmw9q4+n6G9JksUgOz3EK1s3wfqXLtAr9Cl4un8mF1ARMrul2UHsU7IYpvz6/95aj495a4 CNN7g5+w3yVNLprlmEbh/dIoeMEjegc= Received: from pps.filterd (m0246632.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 556HBaY9002375; Fri, 6 Jun 2025 18:07:04 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to; s=corp-2025-04-25; bh=84JJ+04JzOIjWxGcwJ xz2D+8D5+GDqIahpvdf+qqPEw=; b=VHtLsUmLKtwDEnOAVRDwWrzgmw06e4L6Gt S2ZjabsfFFis1CWa1btnwAkrxcZ69SHJjt66BJWAtg99oJ2ER1RLsh4DcVrLLwS7 rqvYCOc0iCYBQ3UZTFzs9JbspjJJ/Saubm2HftO+zpNSKCv0rNg/F4+dk3xRa7AG 10Ujl54I6FDgwQ4OKN4brgwKk43nIxI/lXXnfT7jKcE3Si9G5dMOi9ifLdugufdO VmbLcwX7ym+5+KEdYKW6NWUtQoXd/lpoqD+KcQaYdHejG+oXy4LHVJ+1zPc3WZo8 K0cRMfUOKHNjJt3mhUZD7x3CDvky4W9wPmpRQ+ts059xUQk/AVig== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 471g8j8j05-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 06 Jun 2025 18:07:04 +0000 (GMT) Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 556G5ukR035110; Fri, 6 Jun 2025 18:07:03 GMT Received: from nam12-bn8-obe.outbound.protection.outlook.com (mail-bn8nam12on2068.outbound.protection.outlook.com [40.107.237.68]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 46yr7dtpuf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 06 Jun 2025 18:07:03 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=iR2ZLnHxR0VyPnNurzCRu4kjN6e1zkZZFaePZ4/WBy4tjMomeDj0heUtcgJv+R3mDAkcWMxDLof7Yk4aa+ZxN7uuAxVJdN0wOlq6rK3rfG+X+zT63z6epahRj7+WvYLDMAVcHbwY2IKsCIomazswfpke4VHAO6dJNn4O5M8h7m3aqa+Gspp+SecpnwEILQWNJL9Z7PB3cn/RargUpL4lid/66Hs9W3ZNF9l9ips8a8fT2DuJOIZZgbSBsJGCR315YKQMm7OtZUfBbcfmb/D+ly1wInaNR11teTBwRaOJW0lEBK/trdFnZV8gIhdzwe0fF3hgo7eX4TzYPC/n2zgLNw== 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=84JJ+04JzOIjWxGcwJxz2D+8D5+GDqIahpvdf+qqPEw=; b=WByO3IIpMlwBI+4rY2H7qTj/Nu3O5NyllbG9VMYob2WcADlKQitG7bCAhzJbjt3b2NQyZWNKNe5pO3GjY5P53S7vAkn784/FKu5+nXk9Czm3Uvh6U5lkP5OaIDVp2OHuSQ+eDK+Bo2XNyluzXXUJRE0VCM4Dx39F92P3GtE2KfBQ/lDpiQ1EjEI7b5A2ryGzGoyonDb+NLED3pvwxpYWIprUAc5DUjxte2YgOUYloo0vaVLBsH8aEpe9i2F+8p4Ixmg9ofxCIZsEBQrmBd4KtDp2ErAt1GfjkYGY7hQt7l0dLaLXgoP5YX3ImYr3jD+BojusPahfwTwRgm/Hpt/pCQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=84JJ+04JzOIjWxGcwJxz2D+8D5+GDqIahpvdf+qqPEw=; b=oH9ZZRHAVZmJv2rTXa3QuTYS/gB4Y/nmBEmDbZgtcUlApNKSYx8AMh98ZNa5yPOfDsFq+J+bxm4dKBBN5gvKo6rtzglQmQki6A5PeHVDGcNmP0SOlupKZPBVrhjVi/LzOH/2cEb9srcTq0WIoOlc43N5QynNt9DzUJZt19k4ztE= Received: from DM4PR10MB8218.namprd10.prod.outlook.com (2603:10b6:8:1cc::16) by IA3PR10MB8092.namprd10.prod.outlook.com (2603:10b6:208:50d::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8792.34; Fri, 6 Jun 2025 18:06:58 +0000 Received: from DM4PR10MB8218.namprd10.prod.outlook.com ([fe80::2650:55cf:2816:5f2]) by DM4PR10MB8218.namprd10.prod.outlook.com ([fe80::2650:55cf:2816:5f2%6]) with mapi id 15.20.8813.022; Fri, 6 Jun 2025 18:06:58 +0000 Date: Fri, 6 Jun 2025 19:06:55 +0100 From: Lorenzo Stoakes To: John Hubbard Cc: David Hildenbrand , Michal Hocko , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Jason Gunthorpe , Peter Xu Subject: Re: [PATCH v1] mm/gup: remove (VM_)BUG_ONs Message-ID: <72bb36f2-65b6-4785-af9d-5b1f8126fc78@lucifer.local> References: <20250604140544.688711-1-david@redhat.com> <1a65d0e6-6088-4a15-9c19-537203fe655c@redhat.com> <50ff9149-2824-4e57-8d74-d8d0c063c87e@lucifer.local> <1a7513cf-4a0a-4e58-b20d-31c1370b760f@lucifer.local> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: LO2P265CA0166.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:9::34) To DM4PR10MB8218.namprd10.prod.outlook.com (2603:10b6:8:1cc::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM4PR10MB8218:EE_|IA3PR10MB8092:EE_ X-MS-Office365-Filtering-Correlation-Id: 9fa5ed1b-db15-4584-f78a-08dda524edbd X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|7416014|376014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?7tnlIXEOFsU4VDHc6FaszZf0aZy5tSMI46YV3udUu1e0rdjzm/eApfvc/iMT?= =?us-ascii?Q?JPBPd+YLB3syKX56oEvcpUIEqqyPDeh7/0z/NOQ9h5sZVQ2zfN5YC04+9Jfc?= =?us-ascii?Q?6A3s5AS6kPeu5QNlT43en0HiUmRhVXtUQwzrSHl1sNBJs6StVunTDux2gtOY?= =?us-ascii?Q?lItUHy4ByKpx91NzX0JSxWobAfiKS+s53DJqo8jmOkt5fZAX5xklfsgg8Wix?= =?us-ascii?Q?l5rtSV1UigoleWFDXb4gsA1XBg+bTcrk+66wQulkqXFeBDV2FhDEcrnvLMv0?= =?us-ascii?Q?BL/OxVCMz2EG9AoEsnXzWIU1Nd5Gdm6DczcHmjfnutJWThIu+8zr27Hp9Zpy?= =?us-ascii?Q?UeS09Bg2BUw82U+O5l1LharcasLEZZjTkDTZBCqCokIrQfx+t2pVavtdTLyi?= =?us-ascii?Q?3i5M2gwqNtsngozWqvZ/smJJQzW76W8MORfIQAPAqSxUoPLS21CKKCUBgR8l?= =?us-ascii?Q?vlDSpLB8y2IXkh7oRIlcbZB/95fl+KgtIwyesMphVPqxm+WRVk/oZSUe3MbK?= =?us-ascii?Q?Hzu5E3vIUsnCJoSDuo1dSyv2mJL8cG8iAeQOl6kjZZ76+ehz2a6+fWhMI+yz?= =?us-ascii?Q?iPOeXwPPIK9f3cedSlFLT+yMsxj0BuCSOkC70u9/WFaCf9ZQlxnXskMp3bG7?= =?us-ascii?Q?iHptv1XqCqRNej31CBvCbQ4EavYSMhx/brDo9/GmPXVtw5KFTbWkgorD2JSJ?= =?us-ascii?Q?KU/A8XhEevkadVgkI6KMSCaq4CD1v/S73Kpoccykk8RNkKjqWikzMzjUAOUZ?= =?us-ascii?Q?eEE7rBXy+mmIBYNZNTQAcvoo3LgNt0gpzc9+M5cToXQBywzeAyiFHJznS94u?= =?us-ascii?Q?V711pEDNnQgfKxC7ImngpuugC8NhxYJEyJib0KN9068IK17fKBAaCbVym7vt?= =?us-ascii?Q?5Lyvx3LWUVQzTi1pwLx/NDq6xaRg7I6ZiRLIyoFjOgegmlnsohPLOz05LhSH?= =?us-ascii?Q?BLRr86pj0932HlcprulwP5HU3c/B0HBzcdzvMxghZMesEdJdeWSLrc8PVQ6R?= =?us-ascii?Q?mpf4TshIUTsg04cGU9mI7Wox4DudPrIIx0FAPFNkV+jW5QTK/EVBPDHFySmP?= =?us-ascii?Q?CTDcQ1MnboUWWgIhUuNqP+sPJ5grHcuyJB6tOcKBuZ7cW/mFq0t6AYMhgcIO?= =?us-ascii?Q?0lc44OlcVKDcH6FP58wkkUpSqtaJSKP8nhuwpJK/e30EhG8RF+GJyHBwcz6z?= =?us-ascii?Q?t/ntFghlTSGEAKnxqHTV8ifKFqCZpZCs4bVlVlvNkBScvt5l76SzzRxCmiyP?= =?us-ascii?Q?f+Du7y7PG8//o0ZHIkZjpt0zVxHUoeZP2/EdZZQCQXSnwuTsX0i91J45OFN+?= =?us-ascii?Q?eHbolXuKm5mzthQY7D2bPVeD/95mE1JfsifogaSHR26nw04thyHXuqdoYSCp?= =?us-ascii?Q?0kXupZFN7M3JaeNGw7mnMGHXaNIwyXCj4SdpClGkYpwBOudksBLa9NUZvA+M?= =?us-ascii?Q?EnA5EzBZkcI=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM4PR10MB8218.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(7416014)(376014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?lLGVHivjirb5XJuaSTZ5LD35GA3MYMtcgQigJsEVpjXP3GZXIrciBSbFnIHi?= =?us-ascii?Q?+ZgUKKNoLYGqS485xkXHqF+lNXD1ReTkDjJAKtSMD4FU1JyNf1ZwwptR6keY?= =?us-ascii?Q?Gj6dw/ZnREyPgc5gzCxL1kERBYERk+LLN7Pd0nZVg3jWvydiVatXqTKBb+kp?= =?us-ascii?Q?weQsL64xUfTQP0+FHS7SMOmpPeAg+O6C91lX76FIzfmsX7Boo5EPSIhauoCN?= =?us-ascii?Q?AXfLwf+ij6yVdF8vWfPUvuuSbrHs55BgSqo4pHCGMaGT55cyX+8RhdHnTf3u?= =?us-ascii?Q?Z7az2qSnSBYklr7VcADxvr+NcC/Anpl0yk2oEJhd9gYTZyfNw6TDHclRMJSa?= =?us-ascii?Q?2h9Slo2RIF4T+4Jv634OhiTMfavy/+LDKNkoYff6K2A5nT8vQrWH03mDW1cN?= =?us-ascii?Q?riHMKVoe7CoQ6/OydfhlL/CtqrqQ9C1MCBu/bcUKmlE2EvYn7T0qLIqnVMpU?= =?us-ascii?Q?056Hd4TKVR1i0VfHzjJ5+CUhY2xi2fFbA9whQf1dSlkkhDS1lMZ28UqqYjGW?= =?us-ascii?Q?h+hlZH8598h+FqbaSC5JndvpA8jrHFmGDcNVWtOmUj5Nd0emhrMrwAIKZh8Q?= =?us-ascii?Q?s57zE1AquAX0J4Qa/fSYoWXdxe5nh91vM2mLEnmUZeO4tTgvJ5QciLGC+ypa?= =?us-ascii?Q?czTLjp4rt69piEDleT7o2kjaaCxY4iGLoEBQLKZ9/jwp7SosyNKWxb+xMZf6?= =?us-ascii?Q?0HvQzf/h3AwY3KGioFNyGu97bF9NqqXRib0kwfRyLoStWYjba28z4BSKoF16?= =?us-ascii?Q?E1n0+/JfyhSKkOsJVdDk/kWw1vkCqEiBWjSqtAw0KmFbpEsRqbwX1+gN3BOj?= =?us-ascii?Q?u79g5gFPtn6C92iMbsv6HiAwPLZROeblZIHOwJqXYhWJ/RuXz85R52AjJApq?= =?us-ascii?Q?YEYyMr3vtv/4+ASnSVpwt5I6ZpheDfZNqn62EUD7YIMD7C9oB6NEnbItTK4U?= =?us-ascii?Q?P0dW0xLbXGzvoiDxZcaj6P+Q0QWM6hdTIHXOKs2kWm2oWdQ49BZbpvx9iB9K?= =?us-ascii?Q?7bvE6lm81KcQ3fyDLNv7TNIF3OB/ctC16+cVDMPyAncrD2KlKrbIhnUa/gyc?= =?us-ascii?Q?Azwfw8itkd0tZH9ImpZMbH7CQVdqtY0WqHjJ1lLeDp1lAxxKOG7huzlW+XZu?= =?us-ascii?Q?GVZ+bzYaCP66jpU92McrzSA9vvDJCx7rt/Xq+r9gHmDRA4K33BUECD5LyCu1?= =?us-ascii?Q?LyGXwkF8o6ddb8ZwIIjIpIvIPdkm5fG7ZhB6Le6YfQPzI9ubtjyAwg+TpPwQ?= =?us-ascii?Q?ON4KAcFdrAdc54qRvU6HKNvWK7zb9HBZZgs82KLrbVWVLJ+20g6T9g132uAI?= =?us-ascii?Q?vjROXwU7SI/5+v3pSGFMe41aUxDtD1U+PZ0UGW90zqhU7EPT1pJPH8vYE4y/?= =?us-ascii?Q?QNFYH8n4vTd8wUqxoCdR2Zq3GZOxiMP3j/ZVWqaep84K26/FszdeBQyJXnsu?= =?us-ascii?Q?VEtoVgoFrUlM9y8UFxpb6mJbH+OiCxbuSfU6l6ft1si/LMT+YoyLrkaByS1g?= =?us-ascii?Q?iT1SiXvgUhF9Ey8kpuCMx96ZsmSqH4Y43lwyM0mPBupTi+LSjHzh82tjKDvF?= =?us-ascii?Q?9WfFTcRDzFQZBfScPySbyci6/Cf6EykdiUKlb52ZALOYLdoWuub5x7x0l/Tf?= =?us-ascii?Q?jw=3D=3D?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 9fa5ed1b-db15-4584-f78a-08dda524edbd X-MS-Exchange-CrossTenant-AuthSource: DM4PR10MB8218.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Jun 2025 18:06:58.3750 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: AEHOcz8uNXDq9EbXzgKtIXVbAd+j8n7xxBu8Owxu64RYbeF3+NtVe7LAdg2lQPGDRSPxbZQJN+4bSI7mZw9i6659vuSzCduTeiRt8pFnptA= X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA3PR10MB8092 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.0.736,FMLib:17.12.80.40 definitions=2025-06-06_06,2025-06-05_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 mlxlogscore=999 bulkscore=0 spamscore=0 suspectscore=0 malwarescore=0 mlxscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2505160000 definitions=main-2506060157 X-Proofpoint-GUID: 5wItIeZbtG3JdKaE5772cKWmlGrGImxw X-Proofpoint-ORIG-GUID: 5wItIeZbtG3JdKaE5772cKWmlGrGImxw X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwNjA2MDE1NyBTYWx0ZWRfX+JsxYIJktLFy sSOyFczowjbsdbUZ+XsWZGThCWUPkiSFzy9Pfv1NeoD9borbRNo5RP8V3iBbw85jnUEPRCRxxPI 7nsSrgEr4K93DcN1a8vHisRr80TeClVH/WE3pZxoaeKDfvo0s8wJA87yj2PE+gFTOFQ4R9Bwgc1 WaA7KcVuWkbajBL8S7NMrGbFIFrRWRmh5H1ckXZN9+YGcVbnmNdCXFlIl5ShihCzb3Rtj13hyb5 RQwy3yseQXX66mBVHtR8u0Dv0bGFzG65jEAkpPeJ3RQGX7dOkGrNzZCV3l18qqFDufYJFZYnv0j 7ioRMZnkwMiApLk4LsT/9QqaznrKaXLyKd/9ywB9g3+qplcNi5NT/jJh0icG1WIknQhh2+AnLBF FmQs3ytP6qFDsZssxn+t28yWJfOuI4Pi4pwaQRRQpZXeqZ6RlN41drkPRZ/dxz3FN3IHT94b X-Authority-Analysis: v=2.4 cv=QI1oRhLL c=1 sm=1 tr=0 ts=68432e48 b=1 cx=c_pps a=WeWmnZmh0fydH62SvGsd2A==:117 a=WeWmnZmh0fydH62SvGsd2A==:17 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=wKuvFiaSGQ0qltdbU6+NXLB8nM8=:19 a=Ol13hO9ccFRV9qXi2t6ftBPywas=:19 a=xqWC_Br6kY4A:10 a=kj9zAlcOel0A:10 a=6IFa9wvqVegA:10 a=GoEa3M9JfhUA:10 a=WwM-Af7u_kNKHnxEFAAA:9 a=CjuIK1q_8ugA:10 X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: DD93E80014 X-Stat-Signature: cz3kbgozpe99hpoou35tcc4indb93ftm X-Rspam-User: X-HE-Tag: 1749233228-325181 X-HE-Meta: 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 cedCRsxx 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 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 Fri, Jun 06, 2025 at 10:57:44AM -0700, John Hubbard wrote: > On 6/6/25 4:04 AM, Lorenzo Stoakes wrote: > > On Fri, Jun 06, 2025 at 12:28:28PM +0200, David Hildenbrand wrote: > >> On 06.06.25 12:19, Lorenzo Stoakes wrote: > >>> On Fri, Jun 06, 2025 at 12:13:27PM +0200, Michal Hocko wrote: > >>>> On Fri 06-06-25 11:01:18, David Hildenbrand wrote: > >>>>> On 06.06.25 10:31, Michal Hocko wrote: > >>>> [...] > > So to me the only assessment needed is 'do we want to warn on this or not?'. > > > > And as you say, really WARN_ON_ONCE() seems appropriate, because nearly always > > we will get flooded with useless information. > > > > As yet another victim of such WARN_ON() floods at times, I've followed > this thread with great interest. And after reflecting on it a bit, I believe > that, surprisingly enough, WARN_ON() is a better replacement for VM_BUG_ON() > than WARN_ON_ONCE(), because: Right, these shouldn't be happening _at all_. I'm easy on this point, I'd say in that case VM_WARN_ON() is the most _conservative_ approach, since these are things that must not happen, and so it's not unreasonable to fail to repress repetitions of the 'impossible' :) But I get the general point about ...WARN_ON_ONCE() avoiding floods. David, what do you think? > > * The only time you'll be flooded with WARN_ON() messages is when *two* > things happen at once: > > a) Something that used to completely crash the machine (a VM_BUG_ON > condition) happens, and > > b) You're in a loop and it keeps on happening. Yes, in -mm, that does > happen a lot (per-page loops, for example), but still. > > * It's *so* easy to miss a WARN_ON_ONCE(). We don't want that, not for a > critical failure case that used to be a VM_BUG_ON(). However, I do dispute this point - warnings are pretty easy to pick up from my point of view unless your dmesg is absolutely rammed, and if you're concerned you can panic_on_warn right? I treat any warning that I see for instance in a test run on qemu as a 'must fix' problem, let alone if observed on an actual hardware system. Are you thinking of scenarios for instance where you have a lot of debug output in dmesg and thus these fly by, and when you retry the operation it won't show again and thus missed that way? But of course this won't do much to help you should the operation be one you happen to only perform once however! :) > > > thanks, > -- > John Hubbard > Cheers, Lorenzo