diff options
Diffstat (limited to 'include/linux/mm.h')
| -rw-r--r-- | include/linux/mm.h | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 24c395694f4..9d65ae4ba0e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -620,13 +620,22 @@ void page_address_init(void); /* * On an anonymous page mapped into a user virtual memory area, * page->mapping points to its anon_vma, not to a struct address_space; - * with the PAGE_MAPPING_ANON bit set to distinguish it. + * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. + * + * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, + * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit; + * and then page->mapping points, not to an anon_vma, but to a private + * structure which KSM associates with that merged page. See ksm.h. + * + * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used. * * Please note that, confusingly, "page_mapping" refers to the inode * address_space which maps the page from disk; whereas "page_mapped" * refers to user virtual address space into which the page is mapped. */ #define PAGE_MAPPING_ANON 1 +#define PAGE_MAPPING_KSM 2 +#define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM) extern struct address_space swapper_space; static inline struct address_space *page_mapping(struct page *page) @@ -634,16 +643,19 @@ static inline struct address_space *page_mapping(struct page *page) struct address_space *mapping = page->mapping; VM_BUG_ON(PageSlab(page)); -#ifdef CONFIG_SWAP if (unlikely(PageSwapCache(page))) mapping = &swapper_space; - else -#endif - if (unlikely((unsigned long)mapping & PAGE_MAPPING_ANON)) + else if (unlikely((unsigned long)mapping & PAGE_MAPPING_ANON)) mapping = NULL; return mapping; } +/* Neutral page->mapping pointer to address_space or anon_vma or other */ +static inline void *page_rmapping(struct page *page) +{ + return (void *)((unsigned long)page->mapping & ~PAGE_MAPPING_FLAGS); +} + static inline int PageAnon(struct page *page) { return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; @@ -758,6 +770,7 @@ unsigned long unmap_vmas(struct mmu_gather **tlb, * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry * @pte_entry: if set, called for each non-empty PTE (4th-level) entry * @pte_hole: if set, called for each hole at all levels + * @hugetlb_entry: if set, called for each hugetlb entry * * (see walk_page_range for more details) */ @@ -767,6 +780,8 @@ struct mm_walk { int (*pmd_entry)(pmd_t *, unsigned long, unsigned long, struct mm_walk *); int (*pte_entry)(pte_t *, unsigned long, unsigned long, struct mm_walk *); int (*pte_hole)(unsigned long, unsigned long, struct mm_walk *); + int (*hugetlb_entry)(pte_t *, unsigned long, unsigned long, + struct mm_walk *); struct mm_struct *mm; void *private; }; |