diff options
Diffstat (limited to 'include/linux/ksm.h')
| -rw-r--r-- | include/linux/ksm.h | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/include/linux/ksm.h b/include/linux/ksm.h index 1401a313fa77..ef55ce14a2ce 100644 --- a/include/linux/ksm.h +++ b/include/linux/ksm.h @@ -12,6 +12,8 @@ #include <linux/sched.h> #include <linux/vmstat.h> +struct stable_node; + #ifdef CONFIG_KSM int ksm_madvise(struct vm_area_struct *vma, unsigned long start, unsigned long end, int advice, unsigned long *vm_flags); @@ -34,7 +36,8 @@ static inline void ksm_exit(struct mm_struct *mm) /* * A KSM page is one of those write-protected "shared pages" or "merged pages" * which KSM maps into multiple mms, wherever identical anonymous page content - * is found in VM_MERGEABLE vmas. It's a PageAnon page, with NULL anon_vma. + * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any + * anon_vma, but to that page's node of the stable tree. */ static inline int PageKsm(struct page *page) { @@ -42,15 +45,22 @@ static inline int PageKsm(struct page *page) (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM); } -/* - * But we have to avoid the checking which page_add_anon_rmap() performs. - */ +static inline struct stable_node *page_stable_node(struct page *page) +{ + return PageKsm(page) ? page_rmapping(page) : NULL; +} + +static inline void set_page_stable_node(struct page *page, + struct stable_node *stable_node) +{ + page->mapping = (void *)stable_node + + (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM); +} + static inline void page_add_ksm_rmap(struct page *page) { - if (atomic_inc_and_test(&page->_mapcount)) { - page->mapping = (void *) (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM); + if (atomic_inc_and_test(&page->_mapcount)) __inc_zone_page_state(page, NR_ANON_PAGES); - } } #else /* !CONFIG_KSM */ |