From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=memverge.com header.i=@memverge.com header.b="WDGVXEqL" Received: from NAM11-BN8-obe.outbound.protection.outlook.com (mail-bn8nam11on2041.outbound.protection.outlook.com [40.107.236.41]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5EAEAB5; Tue, 28 Nov 2023 06:14:55 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=NTsSsdcNuX8Oa6mJsUXpkEMHfiHF5s5zMelDLB3mFOYkF7pyixM57DAh8H1Y7mekPlc/eFEmmf/sDZyb+lZFLbUUXHzCODUaoUHKDpP1m7ELad+MuS3+t8GUIuk/rvUMd8wjr1izwSfNH5xGDMa49qmYMO6gMeSFHvvjrLNLZukAHH0L0sVqHsywoCcIjtKolJdDQkp9KmaFDdhPqSEUPqDqvsHAEWZgZygod3U1NDG0j9YVeCTVfeQ2cDFF65v8ZaCnyYAbLZbW8pryZbVrXnYOXyjdMTh7lVaILCgA5PNGJbpR9fU5Dn7qBVTrP8oeRcjwYXzD5Jz4LbdAy38O+A== 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=Jd5ND/9oXJ31iUjetN87bkrJzmWvr9H0e7/w272huYQ=; b=lko3sJQOLiQ58J/bri7GMgeTmNShjXbict2TZbK9WeZb3HBtdB350qDRrD9NDrFflQ8bxsrVUEF9RoOgdq7MDBYQPdSCx5UUlHN3vd2IUiwvgkk5JdB/6CpjCWaqeJIBeSxnzzkKnTlyZuocosBXdyRPG9NHl9tVU6P7SM074JhpYl3OtCm2dbTkJT16/Im9QC4CTdcWwmRqsHp4Xm+72JaydNFV2vA0T5jFklNP6wLHYqrLZT4HJMouvtjLTcP9Umuf7Rvqpe6uUXFhcyYl1YvRO5INJlP8mQ47vTVDE6wnhUVnLiEzidDv7SP3z7DhWZvZkCDLrWmx3YYJ9PPC7g== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=memverge.com; dmarc=pass action=none header.from=memverge.com; dkim=pass header.d=memverge.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=memverge.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=Jd5ND/9oXJ31iUjetN87bkrJzmWvr9H0e7/w272huYQ=; b=WDGVXEqL0I2xXZbdDrwPUG58eGSSP429Y31qQ871YDhjl5E2gaLmWztxJbmO8lRZvJkb69KdeZi6zSroVvOvKSgOfZPfe+tLJmehZbP4t8h4B1CZ0Zdd5NhpWCeXzo9kwsqhEbGH+rP9PF3Yf95ljHgB+idadC1rIRbdCR3Zi4Y= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=memverge.com; Received: from SJ0PR17MB5512.namprd17.prod.outlook.com (2603:10b6:a03:394::19) by CH2PR17MB3816.namprd17.prod.outlook.com (2603:10b6:610:83::24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7046.21; Tue, 28 Nov 2023 14:14:51 +0000 Received: from SJ0PR17MB5512.namprd17.prod.outlook.com ([fe80::381c:7f11:1028:15f4]) by SJ0PR17MB5512.namprd17.prod.outlook.com ([fe80::381c:7f11:1028:15f4%5]) with mapi id 15.20.7046.015; Tue, 28 Nov 2023 14:14:51 +0000 Date: Tue, 28 Nov 2023 09:14:46 -0500 From: Gregory Price To: Michal Hocko Cc: Gregory Price , linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, arnd@arndb.de, tglx@linutronix.de, luto@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, tj@kernel.org, ying.huang@intel.com Subject: Re: [RFC PATCH 05/11] mm/mempolicy: modify set_mempolicy_home_node to take a task argument Message-ID: References: <20231122211200.31620-1-gregory.price@memverge.com> <20231122211200.31620-6-gregory.price@memverge.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: PH0PR07CA0052.namprd07.prod.outlook.com (2603:10b6:510:e::27) To SJ0PR17MB5512.namprd17.prod.outlook.com (2603:10b6:a03:394::19) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ0PR17MB5512:EE_|CH2PR17MB3816:EE_ X-MS-Office365-Filtering-Correlation-Id: 73612d44-d05f-4c72-46ca-08dbf01c62d0 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:SJ0PR17MB5512.namprd17.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230031)(39840400004)(346002)(396003)(376002)(136003)(366004)(230922051799003)(451199024)(64100799003)(186009)(1800799012)(26005)(2616005)(6666004)(86362001)(4326008)(8936002)(8676002)(5660300002)(6486002)(44832011)(478600001)(316002)(66556008)(6916009)(66476007)(66946007)(7416002)(38100700002)(83380400001)(6506007)(6512007)(41300700001)(4744005)(36756003)(2906002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?mOKuM8gKsPMHnyO9RW3+aFy+7PEoNuZRNrsxYpS6bNlgmP1osdv3XswyenUY?= =?us-ascii?Q?Ev28ZMheHO+rRb7wU4+wGLGMVyYBloRtUE9exUSYkg5X6i2VpNkFhnTaWH0k?= =?us-ascii?Q?JXjwNmPLX8qyvT1P70FzUngFozv8JJ9q2k7jsQOs6LjZvant59CIMUrR13ym?= =?us-ascii?Q?o5H8dOvpSRlmGcpoKUsH5ztOEWrRIoiJdGEIFatcqDpMkEZKNBUw742uufU4?= =?us-ascii?Q?9ptbLm6m+/7fIldjq4AF8yHeH/Crg9kJPFNMuvUqIAS9hl87wY4rr6Immw1Z?= =?us-ascii?Q?vBhofGgUl8ukwnxt2BO9jEjURnge77LqQyKnDgqbQ/VtfUWbx88q+rbUj/QF?= =?us-ascii?Q?k3nBVsaNPGoGlCzYXJOg/si8SZaJRqaht7EttletknIy/oKbWZTgTCfzrw5F?= =?us-ascii?Q?matzXDg/7D9GYGRoWERVd/rZGpgscHMQ0pqqGn9YvC3efni39FBgHQLr1PVM?= =?us-ascii?Q?1rjqy914DndMML/fmuV6dWojUe0j0KPZ/PX2rtYeCMTWq+Cfbr05lPTkJQfk?= =?us-ascii?Q?3LAizQjj4G8o1xsE348eum2Whzs9ootR7Bg4l6+U4WNHn6m17K6wP44xj6ZD?= =?us-ascii?Q?XpX1gWo4HbflcHC4HzkYYlHHA69IaCOFMGbbOtC5Y0qZv27A3B+cs8jwi+Td?= =?us-ascii?Q?1r9+kHFSgstdhg9LQWFLa5D0Lv+/4WrullmaV1pCa4eNAh3aniAs/z894pyP?= =?us-ascii?Q?nCIy3MKL05iQlKRRcs6xzgfItB5A8gqLUjE1YyUyVxz8keBS9vXh7TUcQ3sQ?= =?us-ascii?Q?pBZua898MDWl/fC4YaNXtf7SKmQbwEAWO8YKdnb29P4Mba3eWW0bK8rfDYlg?= =?us-ascii?Q?p27kWNNbed4Kd6iCKZgU/OoyaLNP+7zuTVQ5bw94j3lCIXfiWHz1tfld0bz+?= =?us-ascii?Q?LWYR24pzYkotjmWgyZ4N/jyszuBKw25+ycYOGMys7Epto6IBA/IGZlFDoO+N?= =?us-ascii?Q?gmbScKylSCa/n7neMUHmVU5SZmpo8iUmh7Ib6ezb/iz12vMiOP7hEXEX/97d?= =?us-ascii?Q?tWGyxQl+NTri0+ydovKgjUzeQJCr+1tXL8WU9AMC6tapnWjlhSQeqLWw/s3J?= =?us-ascii?Q?jxTgH8HUGp+bNKFJ3xtHscLQDlprgJLWiO9/9b1yR8VsX3FZGkQGJbXcnl+o?= =?us-ascii?Q?FgjuDvjoBQT3VqmE4ykhvRKDUlOJeUEOyAnCtAJ2HIBKfr3AdmMOK2kNzb/W?= =?us-ascii?Q?ldZj/SVUyB9zE9c1VKRrPgucCxuLV9OgEQS+gQz+H69MADyBawcjlJidkaQi?= =?us-ascii?Q?V3sSInXqIMKAmd1En27Qb5+JQjLS+Ee2uKP7JuKiyUSI//M5wFAlBoY/WRXd?= =?us-ascii?Q?NMD2xYjc9d3kuP9qfLtwGXIEPTaUVqOfAmn61Qy43ujM4VAv6aZBz4pqiH1u?= =?us-ascii?Q?egc5jcYlRBsBeyzqORF3/oWexe/2i/r97ghHOpXXrOeCs/24xxJ/+twOmjGq?= =?us-ascii?Q?pQP7eOc+aM1nf5pakITYLEeV8JFNiPFToR6SWnHjUwJyHPqWS2t6+fnY3mXA?= =?us-ascii?Q?KLDe6Gi2Pn8DtV+ORXDfd5fNrFOfS4wDNRk7Of+PPDBAPZQQgZDln7mSsSCp?= =?us-ascii?Q?BO8z8IjnfMvuBxDis690c7eoPuIKaxXFEL58KvDui8KcYuCbCIBnoBKVhFz4?= =?us-ascii?Q?sQ=3D=3D?= X-OriginatorOrg: memverge.com X-MS-Exchange-CrossTenant-Network-Message-Id: 73612d44-d05f-4c72-46ca-08dbf01c62d0 X-MS-Exchange-CrossTenant-AuthSource: SJ0PR17MB5512.namprd17.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Nov 2023 14:14:51.2370 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 5c90cb59-37e7-4c81-9c07-00473d5fb682 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: i3Z+i6+BUjBp2E4hY9UzPRzSaXs/7xWju89SU/LJesboruPylNNqoBm4tEQCcxt//h67Gzi03yKC5RTdMF0HYfMPbIKhmrZc9i6OssonvFM= X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH2PR17MB3816 On Tue, Nov 28, 2023 at 03:07:38PM +0100, Michal Hocko wrote: > On Wed 22-11-23 16:11:54, Gregory Price wrote: > [...] > > + > > + if (!mm) > > + return -ENODEV; > > Is this an expected error? No mm means task dying and mm has been > already released. Should we simply return ESRCH wouldbe a better error > code IMO. This should never happen for the current task so it sould be > safe to add. Hm, good point, and in fact i should make sure that the new pidfd code is not susceptible to this. This particular set of lines is not present in the new RFC (not out yet) but the access to the remote task mm is more controlled via mm_access, so I would presume that mm_access either returns error, I will make sure it cannot return null and check for this. > > -- > Michal Hocko > SUSE Labs