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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?A8rNgRz7sisXQSQvBzSvJ4/VlIqZJgO9lq58eajkLAYj2+aqvP1A01mJ5P64?= =?us-ascii?Q?YlUH2PLOsPiKZjWzNoBxo5S+OCdbDRAHYh8sgD0w8uuYmU7lj/MEFv48WTRf?= =?us-ascii?Q?sDtFKTK3nMJ6Aseics9i6GvK0KUeXKm2Pm0yEqowlERz+7ojuvYW5p1ITzUU?= =?us-ascii?Q?3YYQFrdX7wdC/0a3s2uNggd+MydlSNLPJBtQ9899p9FaFEELXr/W0fyZ0m7e?= =?us-ascii?Q?ng6HmNSxFgTK49qd82ktVLnDv/wCWMS56EcXNGLLDUTzb8BT03Ub2ZwU0GdF?= =?us-ascii?Q?r9RlEUr0bcG5+kn0MDypol1w5qL7E5JcZAF0+/V8m0+bT2TOo7u9V1vH/2Xj?= =?us-ascii?Q?OgcN068f9MjmWO3W2UIwU5mUCcaT4WP8Fc6a4J5zDTwscqkuGqAVvwRtj1aE?= =?us-ascii?Q?jcGrbHCrgLPU98RZ7N767glEqKWJcNI7xoHe4MPRdZlkNZUyjsCK8lBWZe/a?= =?us-ascii?Q?VEzyM2BZswh4TH67FJZaijoGjyGLYEzkJdDON564rY0QBBmjjaMA3HlVnnJ4?= =?us-ascii?Q?jpRxRgK7Z07QITP8GdYsVcSd2ZGqrsY0NuxsrpHrK5bHecbDxZI+g8HV9u4P?= =?us-ascii?Q?VYUikhF0DFvnAx/LVlNM7RbZKhu9PaEPMR//KI5Nplg+vsY4ZJ86CnZnVdOb?= =?us-ascii?Q?jE5+h7Fwq/MJkbC7LP01riPBJkggPqEHTtYbWfMGlLFnWBm2afgSfK78erPd?= =?us-ascii?Q?ypp/lfYAgywOgmYETuGy1J4REGeG7zGrWSIwtdfeZdML/9txmcM7CNZzrUup?= =?us-ascii?Q?MWp7an6zLTLoXao/uVYVzk+m8bykb0nR4qQRvnj1/9vpHmaIrmxT794nz6MV?= =?us-ascii?Q?vbZJzNjCUQF7+HMtJQhuaeC4AbXQtsItnuttw9pKl4gSfdKWiIWn+ybAO1bB?= =?us-ascii?Q?YJPG2CGcGoRlAYQ6v0RpEwG81mlYfmEZ0Vgpz37NwTQyZtx1TUyN/LOLQ3bM?= =?us-ascii?Q?AbNwI6N2H93vvjDlN/qtTRB1vtW1pz2+33fRwXaCe/gH4g1b3/zxtX57x6PC?= =?us-ascii?Q?QbFOBHuTivpi+d9J1JPJ55q5NF5iYmKFZ32tRYLczIQYMsg/AzgO11Yflo5J?= =?us-ascii?Q?GK/eLPeLSewSaTaBSRhz0Y3gJgX6bjK06T4qc2Zwbfh7RB21ydhwekI0pN+K?= =?us-ascii?Q?AZxT5Zw05uCjSymCi5dTU1lTwJ8b42fD69f5qun59saTFoadUH58RqzRSzrs?= =?us-ascii?Q?s4DPUkqUSPGTER2i1SOfSTgIkWGwcMm5b4s3lmIlF2DiQ64bOyF+kG99cs35?= =?us-ascii?Q?LlUoGYEVmUJUA5xp7jomcSpJR0UViMLG4QogPDLBI0Tyq2CoDHmnxKZnWa8g?= =?us-ascii?Q?21Npt18E4rhZGTmM8LBzFdDWnf+PFH53eAL7MiBVOjJwkPKiLqjmisHeQI7t?= =?us-ascii?Q?XIXntHJ1RS8ZM2zsMPeGSDJ4ZSTQYfenJh4JurKbXpZW/riDFA7Tr00l7PbL?= =?us-ascii?Q?R9xOpsuiHVZW4o1nj2EokOyCDZyvHWOx9Z0ZeuFKG3CUeaqGHFVqAzHUE3b7?= =?us-ascii?Q?XFBaLIYrPYbaI7LRPd6phJUn8fhkVWNAYangn+3In8Q7c3nYY3FNV11yoha4?= =?us-ascii?Q?oVdu8bKmDzC8numzzRj0td12XIGMuotbf3hhNb57?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 921d2add-c70d-4099-6137-08de029fe2ca X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB9473.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Oct 2025 17:11:26.2705 (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: Dz48iQ+a2hmzfuJluTkA0nWdyC5XEJrGSdyoNjqAFmjxzjVquDPPFRArX0P/bGAi X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR12MB8517 On 2 Oct 2025, at 3:32, Lance Yang wrote: > From: Lance Yang > > As David suggested, the PTE scanning logic in hpage_collapse_scan_pmd() > and __collapse_huge_page_isolate() was almost duplicated. > > This patch cleans things up by moving all the common PTE checking logic > into a new shared helper, thp_collapse_check_pte(). > > Suggested-by: David Hildenbrand > Signed-off-by: Lance Yang > --- > mm/khugepaged.c | 167 ++++++++++++++++++++++++++++++------------------ > 1 file changed, 104 insertions(+), 63 deletions(-) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 808523f92c7b..2a897cfb1d03 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -61,6 +61,12 @@ enum scan_result { > SCAN_PAGE_FILLED, > }; > > +enum pte_check_result { > + PTE_CHECK_SUCCEED, > + PTE_CHECK_CONTINUE, > + PTE_CHECK_FAIL, > +}; > + > #define CREATE_TRACE_POINTS > #include > > @@ -533,6 +539,87 @@ static void release_pte_pages(pte_t *pte, pte_t *_pte, > } > } > > +/* > + * thp_collapse_check_pte - Check if a PTE is suitable for THP collapse > + * @pte: PTE to check > + * @vma: VMA the PTE belongs to > + * @cc: Collapse control settings > + * @scan_swap_pte: Allow scanning of swap PTEs if true > + * @none_or_zero: Counter for none/zero PTEs (must be non-NULL) > + * @unmapped: Counter for swap PTEs (must be non-NULL if scan_swap_pte > + * is true) > + * @scan_result: Used to return the failure reason (SCAN_*) on a > + * PTE_CHECK_FAIL return. Must be non-NULL > + * > + * Returns: > + * PTE_CHECK_SUCCEED - Valid PTE, proceed with collapse > + * PTE_CHECK_CONTINUE - Skip this none/zero PTE but continue scanning > + * PTE_CHECK_FAIL - Abort collapse scan > + */ > +static inline int thp_collapse_check_pte(pte_t pte, struct vm_area_struct *vma, > + struct collapse_control *cc, bool scan_swap_pte, > + int *none_or_zero, int *unmapped, int *scan_result) > +{ > + VM_BUG_ON(!none_or_zero || !scan_result); > + VM_BUG_ON(scan_swap_pte && !unmapped); Please use VM_WARN_ONCE_ON and just return. Or put all stats in a struct, pass and check the struct pointer instead. Best Regards, Yan, Zi