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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?5eehCHgvdKup543K9835WYbvOfFq7KUPDo8gjY+iMCdnOtG66svEowQtG2QD?= =?us-ascii?Q?QT0C0YK9DimXRxM7GAYMIycUOf6IpRpktHVQGdPXdiZYp5vyCCi/t3Ml0BmQ?= =?us-ascii?Q?XrG/A7L4/+IBOzbSGLVwyXHLYajZWmWD+hhVtDHn8p5nb/J9FXfpUnixfU7+?= =?us-ascii?Q?3+wo2OAFNZEyOyigupVXPOwSSq7mEVcoBYjGJ8C92r8EFFPshh5kiBDNNmov?= =?us-ascii?Q?FbiENQd0QUJcIaE8DL91fPNJytW41TaGLwnk+SaUQt6ETlbVA16zJPsrt1Rj?= =?us-ascii?Q?46qZx3OFrj6SCQ6dcCh3NPgDJwN9QUhvbUaKQG/ETlnpw8KNNOzIiKUDqmcx?= =?us-ascii?Q?vhgL/e8PDpHYGMIRFq1xs6eVbYHCSIRr0BSiUYjBoXcjeElQZF8bqDechC6X?= =?us-ascii?Q?My0B8ahfoTj1Mw697Rx0Sk3GstX02NgPJy5E9hlzdUBUy/rnzSovtwTuTwBB?= =?us-ascii?Q?HUeMYACP30igO6CmWVMdQiBcKDSvqxwSf8vLZbxlQMQZV++IuX01BQlt3UD6?= =?us-ascii?Q?GC8nj2PgrH5mPVoucc0fsVW4/UrHOvjDPWKSwDQZcKDv9qvdnQo0DFCKoLoG?= =?us-ascii?Q?G+tVFRndi6Bv389z3iM/INCkK5jwgRgUPj7Q/1lAQlIr3M8bAtxcfb8OZAVw?= =?us-ascii?Q?PYx0eeiCUvi0PW8UUcPfCFA9g78gXbTB00kbFpCEeaiW4YVkR2FSIcga2SFe?= =?us-ascii?Q?FmgA5TRPLS93s9wRWm60oQEcKrQEfQjDczxuXx30TN/Tm5Spu/ru25NV+h1/?= =?us-ascii?Q?R5NSOxgzrNSP6e9k1FfoC1TRSY0/ndQHfxcDEigPhm3GjQvqSnPVUEaTfQo1?= =?us-ascii?Q?e6SDMQa5UO9uUAK4LU8jGXgWJF/iq141z7tH3PO9XWkjynEy/OliwFs5wWZE?= =?us-ascii?Q?3yN8JyDup6gdURMZYnIubzwJ5+hgxaXMm2mVk23a4IsNbaAqzTEwROHyIDqP?= =?us-ascii?Q?5TOfOpksI6kcBBwqbHOrGJEYGK++Z/uywaJ/odrGBTVc5hwvbfvkPhV6eMeq?= =?us-ascii?Q?FSEFkGb2Re5rS4TUaFee8Exeb9zdqANoY+rQHaIPObiiVULmvI37RzPFzebO?= =?us-ascii?Q?2vHB7Uxq7wpU1siDqzKd8UqryEBshhdU/wiAPeLBUakrq/PVWymgO9/Mpjuo?= =?us-ascii?Q?DkwHesRlYojnS/uaukzQrGP6R6KsMQ87T2WRZYciikd4mOtePmlSMhCx6579?= =?us-ascii?Q?E3ldrgUI6apwKycv86N7NyT2EhyPGFcGHoFQe4aE4lBleBBl63bSBfxGLNPM?= =?us-ascii?Q?fjruXFj/y8IMOzH8YNHR7oE9lH4iNRt6Eg5tqniYwS5FSwQ/HtdVsTb3nnyQ?= =?us-ascii?Q?pvjzvu70TnV73RPaXAujH/x4xJiPuCBv/Fid6RVoZoi4Bg=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: ca254175-5f0c-4331-22ed-08d98f3d69f3 X-MS-Exchange-CrossTenant-AuthSource: BL0PR12MB5506.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Oct 2021 18:06:58.3960 (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: m+axPUrEygphVT4oSBftJ2Fsn3zJ1EFNZfQ64u0yOhSaRPCDDRwkkKOyAoOudqjq X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL1PR12MB5141 Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Thu, Oct 14, 2021 at 06:56:51PM +0100, Joao Martins wrote: > > And I would document this relationship in the GUP side "This do/while > > is required because insert_pfn_pmd/pud() is used with compound pages > > smaller than the PUD/PMD size" so it isn't so confused with just > > "devmap" > > Also, it's not that PMDs span compound heads, it's that PMDs/PUDs use > just base pages. Compound pages/head in devmap are only introduced by > series and for device-dax only. I think it all makes sense, I just want to clarify what I mean by compound_head: compound_head(base_page) == base_page Ie a PMD consisting only of order 0 pages would have N 'compound_heads' within it even though nothing is a compound page. Which is relavent because the GUP algorithms act on the compound_head Jason