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Shutemov" , "x86@kernel.org" , "Tian, Kevin" , Pei Li , David Wang <00107082@163.com>, Bert Karwatzki , Sergey Senozhatsky Subject: Re: [PATCH] mm/x86/pat: Only untrack the pfn range if unmap region Message-ID: <20240723214412.GQ3371438@nvidia.com> References: <1a0884cb-39ed-455e-a505-7c1b2a0e5225@redhat.com> <56c982c4-9863-4134-b088-8dfb4b94c531@redhat.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: MN0P220CA0027.NAMP220.PROD.OUTLOOK.COM (2603:10b6:208:52e::8) To DM6PR12MB3849.namprd12.prod.outlook.com (2603:10b6:5:1c7::26) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM6PR12MB3849:EE_|CY8PR12MB7243:EE_ X-MS-Office365-Filtering-Correlation-Id: c53d8bcc-7d10-489e-a662-08dcab609826 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|376014|7416014; X-Microsoft-Antispam-Message-Info: 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on > that or if we could force these VMAs to simply not get copied during fork. > During fork() we have to "duplicate" the reservation ... I admit I barely understand what x86 uses this PAT stuff for - allowing WC mappings is part of it? If yes, then RDMA would expect WC PFN MAP VMAs to copy their WCness during fork.. Jason