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Miller" , Andreas Larsson , Arnd Bergmann , Greg Kroah-Hartman , Dan Williams , Vishal Verma , Dave Jiang , Nicolas Pitre , Muchun Song , Oscar Salvador , David Hildenbrand , Konstantin Komarov , Baoquan He , Vivek Goyal , Dave Young , Tony Luck , Reinette Chatre , Dave Martin , James Morse , Alexander Viro , Christian Brauner , Jan Kara , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Hugh Dickins , Baolin Wang , Uladzislau Rezki , Dmitry Vyukov , Andrey Konovalov , Jann Horn , Pedro Falcato , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-csky@vger.kernel.org, linux-mips@vger.kernel.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-mm@kvack.org, ntfs3@lists.linux.dev, kexec@lists.infradead.org, kasan-dev@googlegroups.com Subject: Re: [PATCH 08/16] mm: add remap_pfn_range_prepare(), remap_pfn_range_complete() Message-ID: <20250908160306.GF789684@nvidia.com> References: <895d7744c693aa8744fd08e0098d16332dfb359c.1757329751.git.lorenzo.stoakes@oracle.com> <20250908130015.GZ616306@nvidia.com> <20250908133538.GF616306@nvidia.com> <34d93f7f-8bb8-4ffc-a6b9-05b68e876766@lucifer.local> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <34d93f7f-8bb8-4ffc-a6b9-05b68e876766@lucifer.local> X-ClientProxiedBy: YT1PR01CA0085.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:2d::24) To BL1PR12MB5753.namprd12.prod.outlook.com (2603:10b6:208:390::15) Precedence: bulk X-Mailing-List: linux-mips@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL1PR12MB5753:EE_|CY5PR12MB6574:EE_ X-MS-Office365-Filtering-Correlation-Id: 811f0150-4e55-4e79-a8ad-08ddeef13323 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|7416014|376014; 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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?Di7+HYoZhHLGiOzcljW44OE/k8IMzE5L8NHJubYEvzqECa0m0qTN+LvvCoPQ?= =?us-ascii?Q?DJGzrKTLiJAQNTFAaewrBdrushviRZyIIeUJgGuJvc1qlJGAfkJ1PFi8gEvQ?= =?us-ascii?Q?OwP2/fIFoHpg8dg1TqXQL8FoQ3iw45uPHX4NmfuArBkiiLojgNQ3s2IGNxCI?= =?us-ascii?Q?8cwzoqZiyQ46/UCx98uR8jht+oJVaQbjovpHtp0k/4Iut61meU1zRuDztHta?= =?us-ascii?Q?pGxxlQv/vxuqkmCIdXt8Evso6MiXxxTFURpzmrX5AfCpISGuYWihD/l7CuTI?= =?us-ascii?Q?kUn//E/McDsvF0EYlwxGrA/ExyWx4KAjhH65O6rqwvkvKfOjyjLfH28PDjyV?= =?us-ascii?Q?a2cKSsLPAXXDB3PDunAbZJ1gPz0uJ7vYbCHbhUBVn31W6teyIo+Q+z56VvAr?= =?us-ascii?Q?Wik+O92ECIfiusR312tm95/0qtkvV4zwd8272XCyVFB1mR1Hgt3Oj0BMb2yP?= =?us-ascii?Q?ZjculdsL6uvKG4VBLkonpeAPK7tgf3Fand49i3tVwwxJtZGAS8Hkw194RJHd?= =?us-ascii?Q?OkMsW2axpbSDc1ogGaG7I/9irWJ7SuultRqIyyXbWnxjaQzQLn6/C4JjJQ7p?= =?us-ascii?Q?Zt7RNmjMgRcePy2CW2N22+/A8wQazIx0pmCJDc0BbNRFiqW3dgk6/TOjSyvE?= =?us-ascii?Q?TGnjynoJNdO1yWWCN0XY1cwCrZSl2y5HXCgfDS/MMpZ9MWfABlv3IjkAv/77?= =?us-ascii?Q?MnaSo34ndYk1Y2o9iS/d3S3jqC0EvfSqj6LH2RMjmezMksLp7b7URmR16TD/?= =?us-ascii?Q?6JU7U4ecSpsZKeUeHroXjumhyhOOwDy7SFwpfShhZNItsa/VTsn/1WrC4JLn?= =?us-ascii?Q?kD91iuKCdBiZfsFRNAT9G1QUYfn6jMztlBUPFHiLKyvActrRMp5+T9W9X9L7?= =?us-ascii?Q?qP5maWnsbwZgf2jWu42C7EW1gAu+8qYkpAIU61wMdy37YDx3Jph+Tz7WEJXY?= =?us-ascii?Q?Wt0Wo4Xq7o+SFHH9sHzEhDwFrshv1zYM2S7Fre0eIi2HD7d7Xz+3yo8B0BrW?= =?us-ascii?Q?prd1SJ/3qxKkZOUqrxpQn6lMbzwlHnc9HRss9yzRq3AeBfOfD6CNtrjAcwbC?= =?us-ascii?Q?gNgJRFXteSgMQZdO3BM9DsLh7/l9yqCAXo7T68+WOJFqcelCas6HeCn6U9CX?= =?us-ascii?Q?j407Bb15QBzHNDd3Pvbm3v0fWjbxauaNxqXCxRDWeGHE0pdvmYegQY8x3cvu?= =?us-ascii?Q?XTaMFhpUUP9cmwuoTH/vul662VRuCszhow3DHgQZTU6W1yWHAGj3KcK9RMVf?= =?us-ascii?Q?FjHcXr4zFRs+1rRtisju7KL6/TgI9Pf/80fpSY3PIpx/eqZw3qtLWP1C81Eq?= =?us-ascii?Q?xIJ4mjMECxjMuLQNsLjvbUsRKizQ1VCrApu59PwJfnZn/tog76CtxaphBqR3?= =?us-ascii?Q?4db+cBpmROKQsoIQ/mF5qsGxbJ2cLZolnVauvwTKhHjlSD76evWpZwIjTKl9?= =?us-ascii?Q?U9IOQTBSa08vB/d6uhCBCGmP/dRRvK1UD2xhJeBZuPn+g90INMNGjs4Ez8Kf?= =?us-ascii?Q?s+xR+vxp2EK8fmfbwfLlDRIhMc4Ajz1hNgqysZVOA0tF9tcva8kvbxYtQipe?= =?us-ascii?Q?MCNOWtLBGUL1PhJxBhI=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 811f0150-4e55-4e79-a8ad-08ddeef13323 X-MS-Exchange-CrossTenant-AuthSource: BL1PR12MB5753.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Sep 2025 16:03:07.1689 (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: oskmkHeAse2jgaCJUs2Yfl8HL0NEQXj+7yIdF/4uJciqoXgC3qRiBgsqz9TIjNS+ X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY5PR12MB6574 On Mon, Sep 08, 2025 at 03:18:46PM +0100, Lorenzo Stoakes wrote: > On Mon, Sep 08, 2025 at 10:35:38AM -0300, Jason Gunthorpe wrote: > > On Mon, Sep 08, 2025 at 02:27:12PM +0100, Lorenzo Stoakes wrote: > > > > > It's not only remap that is a concern here, people do all kinds of weird > > > and wonderful things in .mmap(), sometimes in combination with remap. > > > > So it should really not be split this way, complete is a badly name > > I don't understand, you think we can avoid splitting this in two? If so, I > disagree. I'm saying to the greatest extent possible complete should only populate PTEs. We should refrain from trying to use it for other things, because it shouldn't need to be there. > > The only example in this series didn't actually need to hold the lock. > > There's ~250 more mmap callbacks to work through. Do you provide a guarantee > that: I'd be happy if only a small few need something weird and everything else was aligned. Jason