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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?453VbxEiuwir1+hoHBzZZDdH/CmxYWbXKjczrfGT8ruKeIBA1RYwWYafi25m?= =?us-ascii?Q?NmCoB1XYvKJF1BXx/AB8xzHPE3mioUC1EaM+oBGk8jnaHbMv/CmJlYPJT3rH?= =?us-ascii?Q?IFQ4HF96XwzjjCqEBMrFQjd2UOHaX6TnEBH+vWRo9CBf0ZnNuBvkofQpKS3V?= =?us-ascii?Q?3Mt9otm/Xs+PL39f+5TNu8a+AzXPS01Jz7oE2E80tqETnGdU5Dcz3vAcKUFK?= =?us-ascii?Q?bW8xOMul9qsY0Izqv+aS0gJ+ZfrnU3PH+ClW12hkU6oqG3jV66+KedQU5hbY?= =?us-ascii?Q?WyILLqe8e+l1mx6a9PynJW9ql8CQAuW/ahp5htqZ34IJc9qJjBuCCEBtbpcB?= =?us-ascii?Q?nfhleJeYuN1aTjfH0eEGYILxlM2+up/yhH0nHEJTbJ0KsY/nYJ5ZHhJauqhh?= =?us-ascii?Q?aDJiQCBELyMn0l2lQMlKxRXdhIQi/fLxJFgrNoFfhC49348TbHwVDKj6SYp4?= =?us-ascii?Q?A8TgBH3XekLQuzTS2nYsMAou9cciEyvLkHY6YcaaSikAuGkgtGD3zyjaJUjB?= =?us-ascii?Q?kvXAI9L71xuBBbG/S+rmVs8Fm4m7umQNE2hf8u8eSOvkQWphmkHeCZExfksb?= =?us-ascii?Q?pTdFEknIqEo2Ii6JO+lpKYoy0rtfLyFO6ymSnZk0lrHLfOQk0BM4mhk3GW+s?= =?us-ascii?Q?UwwXC9J3y493AOt68LkpnMydSeL087zDc97xtGckc32ms3U13SxtlcDQO1om?= =?us-ascii?Q?+WOp6Wv8U9+I5lGE/qIy0fRGlvx2LXgSmq/HpxykZjpMlXjglyRJMDJc0V8g?= =?us-ascii?Q?gDe6aI086lgvDlLzsyOmDGs7TqaRUvEWuLGXR0aqyJF/BUCuFCJgWUG9Jpya?= =?us-ascii?Q?unJ5IPgTIbUGHVurg3Ab73badlZhbLhDaaNJB5np5TK1wJ1AcgRrkVUXIUFn?= =?us-ascii?Q?tMRlEoEEXVy36JtfMjKxWCuDHRVbt51Fbm41P/C1c0GlYHQ5JCXEvwjZTwdW?= =?us-ascii?Q?6UQ22pBlwyusnNhfRblhdJGV0NWHe6swXZgx5FkWxZALGgwKTz/qpF3Zq5ZO?= =?us-ascii?Q?Cq63XI8ZX1EMOuxAFp08mT4my+W0mIMkDoCisJj/RGsxkAR2jIn7iMLCJJ7d?= =?us-ascii?Q?j78QswBCygL1MeNY0qRTv37g4BcWfB+7nZ/8Px1ENU8VsPLX6IJzOdT6Xys7?= =?us-ascii?Q?YVaC7M08g4m24Ljn5PoTMnieu8t1xVaiJeQzQ08S+u9S0OQz9xwr5kVTs32z?= =?us-ascii?Q?LIFuA4es/DXWw6B5sDnegG0Ukf3CWjUGxrjGYMSc0JE98jJmvGwfxxMUp0e7?= =?us-ascii?Q?9XsjKfUOJOR4vOrLWv308mmdLbRlGxJktFNPzfSnNpuEgg8WUK6EPF7dQT3+?= =?us-ascii?Q?e+nMm4NOQPjOn/UwFKN1v1BqdKWvP0DRZfehHN+YWYIcLga+X1EEPTOsjA0B?= =?us-ascii?Q?y7yKDBK3AR5Opo57m3+IyeezwsgcaEhXHUUhGve5c+EdgBeFUvnXFMg74KYZ?= =?us-ascii?Q?VPfBvX1tS/wZgyACtirwaAgVwEQTJNfIcB1OU6P8fXgjXM4UQI2ihTRWL1D4?= =?us-ascii?Q?4GnyDfCRiXfGFrhB7oP6JEN5OqgmyhhOrzX1ngukNJfrd9G+BWQ7pIp39oeG?= =?us-ascii?Q?A7c6CeKCr/f2HSqtEUQ=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 0ebdb881-430d-418a-2ce3-08ddaa7b2314 X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB9473.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Jun 2025 13:06:40.4016 (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: 3fbibWvE/LvxSZW4BXDJnVIwSYu6ixxn9aQ175cahLWT8xay1qHS06gzeo0FYAvF X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV8PR12MB9715 On 13 Jun 2025, at 5:12, Baolin Wang wrote: > Shmem already supports mTHP, and shmem_allowable_huge_orders() will ret= urn > the huge orders allowed by shmem. However, there is no check against th= e > 'orders' parameter passed by __thp_vma_allowable_orders(), which can le= ad > to incorrect check results for __thp_vma_allowable_orders(). > > For example, when a user wants to check if shmem supports PMD-sized THP= > by thp_vma_allowable_order(), if shmem only enables 64K mTHP, the curre= nt > logic would cause thp_vma_allowable_order() to return true, implying th= at > shmem allows PMD-sized THP allocation, which it actually does not. > > I don't think this will cause a significant impact on users, and this w= ill > only have some impact on the shmem THP collapse. That is to say, even t= hough > the shmem sysfs setting does not enable the PMD-sized THP, the > thp_vma_allowable_order() still indicates that shmem allows PMD-sized c= ollapse, > meaning it might successfully collapse into THP, or it might not (for e= xample, > thp_vma_suitable_order() check failed in the collapse process). However= , this > still does not align with the shmem sysfs configuration, fix it. > > Fixes: 26c7d8413aaf ("mm: thp: support "THPeligible" semantics for mTHP= with anonymous shmem") > Signed-off-by: Baolin Wang > --- > Note: this general change is suitable to be split out as a bugfix patch= > based on the discussions in the previous thread[1]. > > [1] https://lore.kernel.org/all/86bf2dcd-4be9-4fd9-98cc-da55aea52be0@lu= cifer.local/ > --- > mm/huge_memory.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > Acked-by: Zi Yan Best Regards, Yan, Zi