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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?PEGM1CDchaVi3bAjBL1qzjKYARNCpEwTiubzmjfIBClDz1Qh49sdnm7kSfvx?= =?us-ascii?Q?J7Y9gH8E2QlaTBRrR078LcRXAZVdDki0Qwtrb6BC9gqeZ2sRddFM++XH8H/D?= =?us-ascii?Q?fFrvW/HlIjum5if9uNLURSKBEWsCU7yEMusb3HJx/gwYiPrXzRIYDxiwQmZY?= =?us-ascii?Q?5vVawqhL0ljFqOTkTroy0fkbxiWyIHKG1aGehQe8k9RAUmlYPh6nrJgXs6mV?= =?us-ascii?Q?5S2F4stO5hHhvg1eOKiledstnzJLjoSesgvcxe+jyu73D4UHLPUl1AthgC/C?= =?us-ascii?Q?/obF0goXfM9PRTnD1op6byTxvVZveBsJ+NF18wf8CPdCHFVry4L90XOnWPC3?= =?us-ascii?Q?OAhMHZeLceI7nOgHNBM8s0ovV0avL4Tf8kRP56S7osqytVrVyh0u4QBgQ+29?= =?us-ascii?Q?Ee9xTFSQFYu4edzGzzo8T9NK3VpCzal9Y6BJmjtCKnnW7uY5sWTwNuUZ1RrG?= =?us-ascii?Q?ifWm7wjM2Spl53lwdztxcwKFYcPztCagwEwbfmKmh8BKKftr5uA6BYj3bxuA?= =?us-ascii?Q?7jdopOMhIDSE3Qol7O1Fcu4km1Zg/O4+qTYl4KJKwAkj13WSEMLSLDxeBNlD?= =?us-ascii?Q?w2WCbLGVfL7IIhxaQB91zPv0aS7gm/1/nruB4Z/Pmdl8hDRuJyliS7zNX73g?= =?us-ascii?Q?NYMc0HgVbTLtRl83TaBfvxD+0kyqzZckcuT9DXDp0Tm0yxePL105v+bA9htn?= =?us-ascii?Q?z2fIEiF6fJzL1FuPEu7ST3q3Cwh1v1LM6ySkPFHI+7gJuUovzqbyWDsXr2wz?= =?us-ascii?Q?jpKKAWQWUpt8Wh5L5arl3EX00CrF6ClIzCf63N1aIIpTuEgeEufdmpfOvCKk?= =?us-ascii?Q?29G4ZIxbfJNcFrq7sZgbgYXfYfMDs8swlL8vpPMCZesgCRdDerQKyWnRVW1R?= =?us-ascii?Q?9fsvlrI2/2ps7z5NPWN5BIl3G7B5WgO4475ggETWzH+NIZbh7zCy+dByCkUe?= =?us-ascii?Q?/mASKehpjBVfi9nZc1eer1zblAfq9YA7S/l5oc12R05ruS5gs/DMnQQOXwYN?= =?us-ascii?Q?iygXMcvZOAHvO95FH9m3kai0w6fw9kcl05ZSgIfVVk1RrqpxHTM87mVhCuRq?= =?us-ascii?Q?6QruB+yTAzw8ZA44U9wY2cN/x0VPQnqN1n4NUPXJdArPdtxKagZQYAg5nygf?= =?us-ascii?Q?nnPB6QhIb+Np8A1UOctatcUfqQWfyRYIbMCClXKtz5q6+PvF+woMT56lvSjR?= =?us-ascii?Q?DgkyaMS6JKGVO8BtwtEboCeLBst/JUNqYZjNhXUNJxbtmSNOjhJca4RmQhBP?= =?us-ascii?Q?xAAxM0qMC7GDFGSjrEtcl4uovWNFlT8MhDsKnlAnafHashYqaU9nFvb9y2Ok?= =?us-ascii?Q?xgmf375hdoAxqQ1T5iySgtguAl9xWlEVVaLym2faNAiUwramtn0gk1uvVB35?= =?us-ascii?Q?S5RhhDFRLqNq3J9RoxsqUVPFqNVoK/qLjFaf18uQc5Lq4e+3NcWt5gZeNNNI?= =?us-ascii?Q?hxVhrf4eyNx82AxWjUlxHZMv6KwMXsyqqnADq5QXHocXTlDOttLydNf51dz/?= =?us-ascii?Q?fsREaiOUtNbRGFB8/8ej+fO9eI+VZtAlDaOWcE203aKMMNUks+KWz5xI5oSc?= =?us-ascii?Q?VJWp21rLudNPUhlqMWnFvAVKoshuY1KDy4xAa1y100OW6KffuuH1N05ZXz1D?= =?us-ascii?Q?Tg=3D=3D?= X-MS-Exchange-CrossTenant-Network-Message-Id: cddb1d73-2dbe-4588-a87e-08dd302eaf9e X-MS-Exchange-CrossTenant-AuthSource: PH8PR11MB8107.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jan 2025 21:52:03.1084 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: O+DmFBUQ3ByAU2CLU7SdMwXBjRKzTI5QFcDSRbLfXEJ6L4UswmwD0bQ+VZI0p4x6wSO4ph6Rt1Sg15kdHtMd7H7YXDcvBl3P+xuqqVwflTM= X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN2PR11MB4661 X-OriginatorOrg: intel.com Andrew Morton wrote: > On Tue, 7 Jan 2025 14:42:16 +1100 Alistair Popple wrote: > > > Device and FS DAX pages have always maintained their own page > > reference counts without following the normal rules for page reference > > counting. In particular pages are considered free when the refcount > > hits one rather than zero and refcounts are not added when mapping the > > page. > > > > Tracking this requires special PTE bits (PTE_DEVMAP) and a secondary > > mechanism for allowing GUP to hold references on the page (see > > get_dev_pagemap). However there doesn't seem to be any reason why FS > > DAX pages need their own reference counting scheme. > > > > By treating the refcounts on these pages the same way as normal pages > > we can remove a lot of special checks. In particular pXd_trans_huge() > > becomes the same as pXd_leaf(), although I haven't made that change > > here. It also frees up a valuable SW define PTE bit on architectures > > that have devmap PTE bits defined. > > > > It also almost certainly allows further clean-up of the devmap managed > > functions, but I have left that as a future improvment. It also > > enables support for compound ZONE_DEVICE pages which is one of my > > primary motivators for doing this work. > > > > https://lkml.kernel.org/r/wysuus23bqmjtwkfu3zutqtmkse3ki3erf45x32yezlrl24qto@xlqt7qducyld > made me expect merge/build/runtime issues, however this series merges > and builds OK on mm-unstable. Did something change? What's the story > here? > > Oh well, it built so I'll ship it! So my plan is to review this latest set on top of -next as is and then rebase (or ask Alistair to rebase) on a mainline tag so I can identify the merge conflicts with -mm and communicate those to Linus. I will double check that you have pulled these back out of mm-unstable before doing that to avoid a double-commit conflicts in -next, but for now exposure in mm-unstable is good to flush out issues.