diff options
Diffstat (limited to 'mm/internal.h')
| -rw-r--r-- | mm/internal.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/mm/internal.h b/mm/internal.h index c6ed10f0a5ad..d99ffb473f90 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -941,6 +941,13 @@ int migrate_device_coherent_page(struct page *page); struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags); int __must_check try_grab_page(struct page *page, unsigned int flags); +/* + * mm/huge_memory.c + */ +struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, + unsigned long addr, pmd_t *pmd, + unsigned int flags); + enum { /* mark page accessed */ FOLL_TOUCH = 1 << 16, @@ -1015,6 +1022,16 @@ static inline bool gup_must_unshare(struct vm_area_struct *vma, smp_rmb(); /* + * During GUP-fast we might not get called on the head page for a + * hugetlb page that is mapped using cont-PTE, because GUP-fast does + * not work with the abstracted hugetlb PTEs that always point at the + * head page. For hugetlb, PageAnonExclusive only applies on the head + * page (as it cannot be partially COW-shared), so lookup the head page. + */ + if (unlikely(!PageHead(page) && PageHuge(page))) + page = compound_head(page); + + /* * Note that PageKsm() pages cannot be exclusive, and consequently, * cannot get pinned. */ |