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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?8/l1wavNl51SiztrymugZrY5zs13Jeaq6wd2Q+SyWdPtpA0hcFuzwUBOXf8G?= =?us-ascii?Q?jWnvfJJdeLtjWy4XEoPbcKlvGLL6HY5BLUTilXgnFBC37aJhGuc8/Q4wWDBD?= =?us-ascii?Q?n5DPryP+AYpFj+5N1YKYd8WNGuP8L6YW1cEFmcSmS4Y/X3toWaOgxIo0JQdI?= =?us-ascii?Q?niIXO+erjesqiPC5mxylc0B7Y+BkfQiy4J7GICRSjaAnr96LHUDesX6Y5r78?= =?us-ascii?Q?xRbxLcOEvleMquN5LC/svyyTmoOeGHt9yBgqr+XJvuv6ziHGHKfDhJ8XAAjM?= =?us-ascii?Q?VnIYiRpyZSbRm3QkWpxeGEnhmdM3S3RhtBbJbslxCmZDsHNo3l8TXnmixjWA?= =?us-ascii?Q?ZOrQ+62cwflR3REkRZX4/g3M1AyeRQM7tRcEOlUPvgVrbtDnBratqpZ9/+j/?= =?us-ascii?Q?78TUd8jD+6lACI85Q5dNp4AxsChTQGYgURT+0fFDO6ZnyA3svWkte09KStx/?= =?us-ascii?Q?FBkBqBpcN5Wm0xKY6YjsK5Ztx4Mzwb+fA1OyQjgYEDhc+Mv1gBAwufAM0az/?= =?us-ascii?Q?np4YxJQcQ1b0lQaeCcyJcyp02uzvACnva/ksORs9jqGpTxMm6xnv763cfOZi?= =?us-ascii?Q?YEnmalsp30CLVOJBeHN0F1py58+Gn1ZV1HFX79BBFnubVAcRc1HEDqBHBLmO?= =?us-ascii?Q?cWjwEYYMHjprd9zeg1HK1lqDYmrKvJ8YmIdDafgQof3ML6MQRKLDnxBmze0p?= =?us-ascii?Q?QcrK2LV7hrWClQvRo+4tQ6TcE3y8l/y5++q8ZLidFoMOZOdChaR4Dt47Xg64?= =?us-ascii?Q?lKfynqtLTHVZSQ+ytJ7Pp+Kz/acnqpTX8WTGVmDvcyOgdscSUDqq1VztdbTc?= =?us-ascii?Q?wlmOX0a1sbbsCs5hVmF/urAVZDpl836cHCDY52gpPm4x2xrAccH/WQKGaGZ6?= =?us-ascii?Q?6wPMpsrAlwACJkGl3Q8b7ngoZ9iB7KFbaxKCTRBlPIc7+5azpFspnsGBWklV?= =?us-ascii?Q?GtePWrtRRipkjv0584QR5bnfbdz2iX7wd4U5fYkYd8l5lcC4xxRN4DCSPNsk?= =?us-ascii?Q?NHoFfSg1DwKORvJ/lqWeWjFW5ZlRlNF8uzBiMrSN/lS8IPnWkA7u6Y2DyvBl?= =?us-ascii?Q?eLvZ9bxtSRbe9xDxboyiNnyXztbHWkk3lhG04XjIX/HwHgugyp6D12RyNuCI?= =?us-ascii?Q?NTVAOxSSp0O2EcewImZocIbdk3o7KtiP9NMMdHTQTcltLCtzWTFZG0QPc0bQ?= =?us-ascii?Q?N18p8NylRU2iHSoA+KC6OHatN4tKAlAd9m93SL4IiFoCn6mQ3QuK2/++eyJK?= =?us-ascii?Q?KRsyZlVAp4Yd5KjIAG57SnyK91r6EMg51Z4m6M+ii7aGD2kRdh8xMnVbzDSA?= =?us-ascii?Q?oNvU5WLU/gRkXmNXKEP5xEqCe6alWt43tzLqDuHwsEORj9DgoM79mJQqt8Lt?= =?us-ascii?Q?IBTd/nZxzeE/T7U8/zUQIcpAeFDDm+uGmQXVxAugtSU5114+mLVNhX6TCQJX?= =?us-ascii?Q?z6Sc+AuHCgPZc5iVYeYpIxrdtxanoX6x8uTzQrMK2opeZtIhrULf8zbbdOmP?= =?us-ascii?Q?C50NasdIR2vMdZBhFt+rq5wI4MTRJUbpDYenhy05eoZdQ/EBDdaXuXQDjxFf?= =?us-ascii?Q?OiENqCBq+eFiuepaF5NvLYepO5ENyBb1FKrYXW1DiOUvQFpDdBqnnaxlEF25?= =?us-ascii?Q?b8TtUDSI3mwyHJd+96icQnjBxTCF/ZET1Y1imxnmitcS4f6JbZghvZZ1/AHx?= =?us-ascii?Q?zBZFL0asEKPjhwlDCULXXhMXFtSZKPUe6i30Hqr9AEcOnSZilXAZmQ0Fi5D2?= =?us-ascii?Q?T1vZZRdSxw=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 15c0c4d7-a713-4c2c-f9eb-08deaff169b2 X-MS-Exchange-CrossTenant-AuthSource: DS0PR12MB7726.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 May 2026 06:40:53.2444 (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: fpGwi8xgwD11zTK0d4UUpKctde3kVEOyvGV7H1/j0k1UDQ00/xxhDBDCONK6r6TXif5tX2BRFQWSpDBIT6miIQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW3PR12MB4425 On 2026-05-12 at 11:05 +1000, Zenghui Yu wrote... > On 2026/5/12 0:38, Zenghui Yu wrote: > > Hi David, > > > > On 5/11/26 8:47 PM, David Hildenbrand (Arm) wrote: > > > > > > We do have a call to pgalloc_tag_split() in __split_unmapped_folio(), invoked in > > > __folio_freeze_and_split_unmapped() before calling > > > zone_device_private_split_cb() when iterating the folios. > > > > If I read the code correctly, pgalloc_tag_split() in > > __split_unmapped_folio() deals with device private pages' alloc tag. But > > what alloc_tag_sub_check() warns on are real system memory pages (device > > page's backing page), which are allocated by > > dmirror_devmem_alloc_page()/folio_page(). > > Sorry, I meant dmirror_devmem_alloc_page()/folio_alloc(). Sorry, this crossed my other reply. The above analysis is correct - we don't call pgalloc_tag_split() for the backing folio. Doing that fixes the problem, but I'm not sure it's the cleanest way to fix things - arguably we shouldn't be allocating compound folios for the backing store anyway. - Alistair > Thanks, > Zenghui