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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?B+2Wsmt1/WWdFq0H5xuatIl7v121FefZrwraf+5elwd9VC2Zf7yKFhqZoMoe?= =?us-ascii?Q?ojEAkJQjnS74N7+bFYG6FjXNwJ+JxaFzTYhX76r5h2Ht1HyRrzKYmFLRDEbB?= =?us-ascii?Q?VXQgyrvaruSFwZBFkYBIJj+mpTJ4yWlXl/y1+S1PlsrP3z33AOmowHjLqPxY?= =?us-ascii?Q?u9F+MGm9RFVBHDnwMEipwLz3R37EitswXiosHD97AYwP8Jgxa9tLcdf4TGEa?= =?us-ascii?Q?S4WZDpjO5OU432hWD+Y+1xHvwlhh5rW1+Gpf5CqT5J2l1TMeZWXVVgc0+y4i?= =?us-ascii?Q?uqgkaqt64MUr3JKw3fok4cOTQcPssYVC8NY3OOBzgmIs0pK0pxg94LQbXzo1?= =?us-ascii?Q?y1npt6mKKBOb6aSiKbpH5tcIGsRibNzLrNEoyYQbmaRpDQsVzQOEBn4PJAei?= =?us-ascii?Q?AiOyVOE2FG2GRGVUAe+alWAuwye3lvChh/Nvp87nKOOniitQ3qyl+T636M1I?= =?us-ascii?Q?W0dosnbXeWd/3SN13127s2KJtmWh2Ybk/W13qclpiexFmtJG2DwDDJrf48GJ?= =?us-ascii?Q?j7Mr52KeSDDbcbsFgX/0MGRMecf+F4UkAM8w/uNUxCz2D/+6kRDU4fEFv1aT?= =?us-ascii?Q?6pXHvbofLO+ReP/aXeUfWiNTK598E8Q+DuJdy8CgX6moDxrZNOyfm9lqweM7?= =?us-ascii?Q?e3o4SNpfa2gZhqpkY6BGsY875aajvuvd3VN5tEYYoKbD25selRIhooY2M7wo?= =?us-ascii?Q?vT7GJRy/sg6Xg0O8jd6jgqTliFU8pH+YKeibbK149qvdI4+BQBDd1QK8U27z?= =?us-ascii?Q?F8Z1eeWWex9IgXuGU7ZutvYCCj+DQoQPkST3YvhC25iMpfdhVV7204O+IxtH?= =?us-ascii?Q?FizIlmBbMoOq9IPA3IKRkEe0D7wj93CkM7BFirbamGwgC+D6fzj0HQjSm8Ek?= =?us-ascii?Q?bC+YEK4IefJuRbQOjMSN2F0cx1G68lk+zpF9uGkg+JRIyO5cBdb4mXzz6r5v?= =?us-ascii?Q?ne2GRFmIiCSQSY+OrXRjXetVUXZVfSgzzcEhZ84t7CnNZa/sK6GAKDhWpzj0?= =?us-ascii?Q?yc6xMyvQmzcNTC3MLLWtzwkxYgdGG1jlIxVE1GaO34GhvwS4dsdDmKfEgQG0?= =?us-ascii?Q?aaU4g4PhXDoxWZ7u3I3KhvFpHxFln3IaInjq7s6x3l5J79GyKE6CGwjFNBKX?= =?us-ascii?Q?a8/LQyg+U+2Cl+XhWA7jP322qrRxCvqhLAcxxKXsbh7zn1jxQr9+F7GAIpUG?= =?us-ascii?Q?QTq1u0DAnMUiXLREFUcUgs9enYzhK2iJuuHeQQAWdDMv2LgnTjLEi+LaQiLb?= =?us-ascii?Q?FEzWKEaHoPdFiaETAaOYWOSrNiuAaRrDB1JglliO4Xo11xL/QtZNtZd11Deh?= =?us-ascii?Q?QyPGMSJHk4d9Q5f1yH0LVtyokMdKSlSKPaAt2yXxrfVoV6pdYvmfrb5XZGU6?= =?us-ascii?Q?Y5auajy5M/n9P4Jo5CqCEQoUPrHYjuvSHToj/Vi/MRDKcWbHZ2H/rEjRg9B0?= =?us-ascii?Q?Xh69ak0bZGgtfvdyN5J0mNQgyF7C54JiGBVotyjWhNb+PMc3gxU/FJFDdOSe?= =?us-ascii?Q?3IkU49MOYiuGqEuXmHXxmHSUrO99VvSS1tLew0HeAU5YwUlV8klEwz3JWlAt?= =?us-ascii?Q?RH9/jSotFKpigdeo001KhdyPYbNYyZKMQEIOlOb++Z5CKbIMkeK3A7g/c+kr?= =?us-ascii?Q?F5yoJ/rVWLpSNJmihsJYhnXRDAzBrIWFDBWYOAJobsNKMiQbpwTvHEeXakxH?= =?us-ascii?Q?1gEh2SX2Pzh5ZTtGez3Yq/sAvPql10Y8kovKOTXumzyYC3E8?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: ae3227a5-e79c-4218-93db-08dea563ea0c X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB9473.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Apr 2026 20:22:48.1384 (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: Q7ugkE17OPTB5f9l/UjiqC1yaZH+AY8WOn/Rkpyfdt4yVrNon0WUDE5nK/JGTiw9 X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB4417 On 28 Apr 2026, at 16:19, David Hildenbrand (Arm) wrote: > On 4/28/26 22:17, Zi Yan wrote: >> On 28 Apr 2026, at 16:07, David Hildenbrand (Arm) wrote: >> >>> On 4/28/26 21:56, Zi Yan wrote: >>>> >>>> >>>> This patch breaks the khugepaged test for READ_ONLY_THP_FOR_FS. >>>> >>>> When I ran sudo ./khugepaged all:file ~/ on ext4, >>>> >>>> collapse_max_ptes_none (khugepaged:file) fails. >>> >>> madvise() still works? Is it maybe because of dirty folios? (but that should >>> also be the case on write ...) >> >> I asked codex instead. >> >> Basically, mmap(MMAP_SHARED) makes the written folio dirty and the folio >> survives the later drop_caches. Adding msync() fixes the issue. > > But why doesn't the write() make the folios dirty? Or are we running into some > race condition where the old code just worked by chance? > The fd is opened with O_DSYNC, so the data from write() is transferred to disk when write() returns. Best Regards, Yan, Zi