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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?idEDJ0TymEDltygLzbW5cICsiiP/ZF52l0XbDLd/L577ZlvXbNqoZAoGT+S3?= =?us-ascii?Q?JMbkTTUGyKl966/ZwSmLdXoBn1prn+G8Imm7f8NlkixbkAiUhseJOqIkd+O4?= =?us-ascii?Q?iFclOHS1RURsJCqPipeG9DIR5BPeNtDh46XNqDiNbde2cAl3i6TKqb05D4nL?= =?us-ascii?Q?EuqM2OfZv45UX/YrEmePztbSowB2fQHlOK11a6kw2pZMRPhNRh8ISab/pv4i?= =?us-ascii?Q?LyEqoopdKuCImLXIclKBK6tY60+1A1S5JM+doLtsuwAgRSwNV1jsBEeY3/RD?= =?us-ascii?Q?42m+EKNUIiJZTOWMnTm88xZ77lmv7LyZuQPOLprDBW3QUO3+cZhLsMMP0RGz?= =?us-ascii?Q?wDds3M4W12l53Nd/WxRbp9gAK5+IlYyFnCRrDxBBLjE6Hc9R/xPAC7paIm1B?= =?us-ascii?Q?Gms2ElglDtAwxRy04Yq47WpaA4c3TBJuf0cnoReiAPNbni62gtYVWk/jIdhe?= =?us-ascii?Q?sZflQfcq8/2Vm18aNrwiy+tudl4idbrBbvnMWOyQuqZHOhodKbVelE8iZlTW?= =?us-ascii?Q?J+L6ASNWULoAPrvAQvkH2xOi5gyGEUS77tjlH8/zyZSMMSbEO0A/usbH9Urh?= =?us-ascii?Q?BHg6mtfs4Gy5SXde9OfJVGnpzo1BiANoKVnYraGnaz0bCYE7dlIuTj4C0NXr?= =?us-ascii?Q?NV/yc4B/0tjUsKbbuqYVk5Y0k59VPRDDZM93ZjH6o1/rWdZfobMQ0J4HP76B?= =?us-ascii?Q?NI28lW7eVD0RYNU0kSBBywXqyOC3f6GZObgJupVz1PT1YreOSsO4f/djiiZH?= =?us-ascii?Q?9e5GKuWi09PSCf0unYWPMg2UF6hy89/v6Yiu9d3N572CkfiaZrhATN4HnDZ0?= =?us-ascii?Q?O2VuL4QJqTQClnwwXFMv2EOcWSshTcKqrYYzXV5fVQCWB4zjSPbJflVcbIjF?= =?us-ascii?Q?lh/g2g0I5tD1tDV1VicWaBCeeQX1hnR0bmtM4udyjVnZnJq9U4OAuKASrBG5?= =?us-ascii?Q?N5GP4C9VKvZ4/3ogXB6RUFRE55t9+6k8j8Jw7nUJDbORFIlY1dYOVwh6LxH4?= =?us-ascii?Q?LYonEEHAJ8fAKw86oXBJc8x4cu6m/uhtE75gW6CCVehM+OrTB0va1uen23KU?= =?us-ascii?Q?fHVC6M8s4mzIxVheyoXyVRCDJ3xyoQ0uxk4/s5advxIx1HS0i/Xewa3bgBOr?= =?us-ascii?Q?Bonnb0sIcmqYWA8YzdPzY2TCG+KjE6CbTtnaVOKHs17ko0W+Gj0C3Ic7uCNr?= =?us-ascii?Q?onT5Pe1cJOXXVGtzHebhvclQBSDcA1oGPXdFAPyOnsUM2QOydTuQlP89rNC2?= =?us-ascii?Q?+xS2GCU6VynojYLIMN7F6dDr3J/5mL3BcQjFcXWdJqm7rv6W79DFgB/ddNsT?= =?us-ascii?Q?aGYOEWsuwpM1fKJDCXwQIpaHpfYbpmDQo2LvgLhywYGykhh4DA8mYQ2aRxBZ?= =?us-ascii?Q?ng1O9NBrlLiTET/poERn0UQHQhFJYIyTDZIYR7GpwW0QhP/EvOTcM5IUpAKB?= =?us-ascii?Q?1VCVl910WUzlXa6yzhjqzJwTjf5Pl8E8EkuazlYQuPjvQFntG52/dglc3k6b?= =?us-ascii?Q?7SdJIvpnqFuogtHls0Hi/LozIFo9BwVlSSQdGpKmpUr5KPOqveUggrTCzTt/?= =?us-ascii?Q?0lg3DzV+svfOaFQFZD+HfGATAmVoojUhOyx9TBbN2lhGKzTxVu4YSgU1PxM/?= =?us-ascii?Q?wwctx7lSWFoF1rk+pEE7y+W3zfJi8UiEmYQBFrqn7LLheg0Mq1voeJczX1Bx?= =?us-ascii?Q?BiKU1BJhANTI4+kvfbZ97RMNVuqYMzBnOcq0Rt+olosyYV0z?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 6d497249-18e0-4042-825d-08de7ec57deb X-MS-Exchange-CrossTenant-AuthSource: BL4PR12MB9478.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Mar 2026 16:53:02.1060 (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: VioWOAeIRwySSwwY4XDR9P6lqEWb2PiL6Ug+XbXGvXca9lAH/H8O4Y2nUh9Ub7Pi X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR12MB9529 On 10 Mar 2026, at 6:54, Usama Arif wrote: > During folio migration, __folio_migrate_mapping() removes the source > folio from the deferred split queue, but the destination folio is never > re-queued. This causes underutilized THPs to escape the shrinker after > NUMA migration, since they silently drop off the deferred split list. > > Fix this by recording whether the source folio was on the deferred split > queue and its partially mapped state before move_to_new_folio() unqueues > it, and re-queuing the destination folio after a successful migration if > it was. > > By the time migrate_folio_move() runs, partially mapped folios without a > pin have already been split by migrate_pages_batch(). So only two cases > remain on the deferred list at this point: > 1. Partially mapped folios with a pin (split failed). > 2. Fully mapped but potentially underused folios. > The recorded partially_mapped state is forwarded to deferred_split_folio() > so that the destination folio is correctly re-queued in both cases. > > Reported-by: Johannes Weiner > Fixes: dafff3f4c850 ("mm: split underused THPs") > Signed-off-by: Usama Arif > --- > v1 -> v2: > - record whether source folio was on the deferred split queue before > move_to_folio() (David) > - record partially mapped state and update commit message (Zi) > --- > mm/migrate.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > LGTM. Acked-by: Zi Yan Best Regards, Yan, Zi