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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?IU7MOurdNYm6htQMk9zJRyoGv9sLyMkBpO5kcc58W1TCdiCDlJ1R8J/BUOql?= =?us-ascii?Q?8kC4GdQytUtmyWl2MX8Ui9+QRQ5seqTVrnKFv+Q5SdNORWwQyH1X02W4yNjJ?= =?us-ascii?Q?hxICTBPA+hEP6T4WHyzqQIhYYn1s9vUUZMbG/TYQYOhy+o+YkwMPGwYl00YX?= =?us-ascii?Q?WAfRb461UnF/lReZpHg6ROzbRfyiuXNMBS+yBXlcXQVf1OyXmg6iHnQmLs5p?= =?us-ascii?Q?9s7lEXG8wyJczeMkZUhiSlO540w8vsNRFSJjRfn7Wqqxa51TgJX6pH1a+o+S?= =?us-ascii?Q?pZRHvSrp0KggBuZbE9c+P4DSXIpIAO6lGkN/wWDNXR4Y3J79ATQxy2MY3FWX?= =?us-ascii?Q?zKqXwF8iTCuyPSfSFPLfb5cwmWQMCR4WchvlH2zINfcHpiKT9Z1OExuVh1HA?= =?us-ascii?Q?EZHqssxyWyrzkZqWuzsXCogA0jpxqLGinLb+4iyO4oiEF/qPfQ3XiPB7WgJF?= =?us-ascii?Q?sV1MJsOPLn253wvvS7zQHkjijiG/w7wKklK7IrccCmMIisuxqFhooCrQTb/Q?= =?us-ascii?Q?rfXd1gs6YrJVXCyt479anMV9+t5oxjoSU1U0U8V76aTBV72FUZtftDU99u2s?= =?us-ascii?Q?O3Hr3Pgo7+l2zR65DPsIr1f37lvPl/2hbBNMGUTUbD5UmOGAbIzG35KEVV6g?= =?us-ascii?Q?o9vzpauaNm/XIJcBmRA0VJ4wam6vxlB4Zsiq36VqUC+Fr/jEvYTQMvcf2hTR?= =?us-ascii?Q?LwAA6iIe71WxMcIZQnQ6rfQVl9fkCwt/b2KfUCw6q6nrT1N2Wg9WsEvecep1?= =?us-ascii?Q?+xlIUc3F1R1qzwHUSvyIWj3ruNGygiE2vF/kCUlMTQAUwbqTZswR4EtU7XOi?= =?us-ascii?Q?tYyJBB5TMz61fE5hU9Qum1+JYNAhRGK6DtVG9k04/PSNdXDTO/+B8vFUoSUh?= =?us-ascii?Q?LYxH9Xql/9E1HKatr8SjBvst+AP7yXG2Yfb3I/fc/2WzRAffVYHt30sJVnwc?= =?us-ascii?Q?rfJWwTuVLr+H4DlHfDb239p3kYWpY9Io2HHivAfdjz1ysZcJ5MPqgEjKSVNO?= =?us-ascii?Q?LJxGXuKvMGrLUx6PzExDxRtEr5DyebUeh11o77YFw50cKc+/haur4+qT0104?= =?us-ascii?Q?muc+asNniHwyqutwKrydxbsVzchhFBmLG17RhsY6iNjPRUW9Xnpbh/MPB/eN?= =?us-ascii?Q?VEnrgpCOZzoULbtAT72xK1Loya2503jtkx0XU0HRbokNueLeHAPQWnU9VPmP?= =?us-ascii?Q?7iaTxE0owD7sbNiIMjGW6E9kJfC1C1mq3+6n5G0GKNa/ZDrWZgmJMpPgDJ3F?= =?us-ascii?Q?z0C0PAnFdRlKypjk8F2escS7K5guP81ctgCkK0vmUACg9ZC2wUe76qZWVr0E?= =?us-ascii?Q?Y4KXy3DLTRYPwbuSMS3U7sVUYmGTuN9CyX2A5rRZAXq4u49DjSqVMDO8+5e5?= =?us-ascii?Q?I3dcK9zoi0e/qQsergGGeozjRDezGnTxbxRSDS3shx1702c3yV2Q1/jjh/qd?= =?us-ascii?Q?KT5MWoq2JTzal6IxOSfaCj0UGAfITIr1OYsGRGEJlnnoTfWPFSf5YAF7pnae?= =?us-ascii?Q?xJmwVnmHdHlG2bZSLRZP/p5CGLKU3MAYp1zZ6aHzl4mwTtfvnibusW4lcLIr?= =?us-ascii?Q?UMuh0LpGns+0lqx7ilm184SPgm5Hn8cUZTLzUs+Nbm7S0gSDtMyl7i78KUlx?= =?us-ascii?Q?y2rPGX5BEKY5k9YW9SnB2JduTo4DVkjf9SQ6Sy9HgmpGknCjggS3bM0Me101?= =?us-ascii?Q?VNsJ3W5cMcLnWRXnP/WP+4YB+sG/22rBM6x2UF45LiDc6UpG?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 12e34135-4201-4159-8986-08ded5efdef2 X-MS-Exchange-CrossTenant-AuthSource: IA0PR12MB8374.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Jun 2026 15:05:34.8764 (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: 4wz1pN1ff7yPrl5418NlmGaBeDmpPD0TqLUXcQ89FAzipyu5q/AO/VqWjC+1bLJQ X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV2PR12MB5990 On 29 Jun 2026, at 10:39, Vlastimil Babka (SUSE) wrote: > On 6/29/26 04:56, Zi Yan wrote: >> page->private should not be set in tail pages. Commit 4265d67e405a >> ("mm/migrate_device: add THP splitting during migration") removed it >> without a proper reason. Add it back. >> >> Signed-off-by: Zi Yan >> --- >> mm/huge_memory.c | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >> index 2bccb0a53a0a..037d67fbec6e 100644 >> --- a/mm/huge_memory.c >> +++ b/mm/huge_memory.c >> @@ -3594,6 +3594,16 @@ static void __split_folio_to_order(struct folio= *folio, int old_order, >> new_folio->mapping =3D folio->mapping; >> new_folio->index =3D folio->index + i; >> >> + /* >> + * page->private should not be set in tail pages. Fix up and warn o= nce >> + * if private is unexpectedly set. Do it before swap.val assignment= >> + * since private overlaps with swap.val. >> + */ >> + if (unlikely(new_folio->private)) { >> + VM_WARN_ON_ONCE_PAGE(true, new_head); >> + new_folio->private =3D NULL; >> + } > > The unconditional warning means this is not expected to happen. In that= case > it's odd to check and fixup always, but only warn with CONFIG_DEBUG_VM.= > > If we are reasonably sure the current code is OK, and only want to catc= h new > mistakes in development, we could just VM_WARN_ON_ONCE_PAGE() without f= ixup. > > If we are paranoid, leave it as it is, but drop the "VM_" ? OK, let me drop the fixup unless others have a different thought. > >> + >> if (folio_test_swapcache(folio)) >> new_folio->swap.val =3D folio->swap.val + i; >> >> Best Regards, Yan, Zi