diff options
Diffstat (limited to 'include/linux/rmap.h')
| -rw-r--r-- | include/linux/rmap.h | 45 |
1 files changed, 10 insertions, 35 deletions
diff --git a/include/linux/rmap.h b/include/linux/rmap.h index e9fd04ca1e5..830e65dc01e 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -27,18 +27,15 @@ struct anon_vma { struct anon_vma *root; /* Root of this anon_vma tree */ spinlock_t lock; /* Serialize access to vma list */ -#if defined(CONFIG_KSM) || defined(CONFIG_MIGRATION) - /* - * The external_refcount is taken by either KSM or page migration - * to take a reference to an anon_vma when there is no + * The refcount is taken on an anon_vma when there is no * guarantee that the vma of page tables will exist for * the duration of the operation. A caller that takes * the reference is responsible for clearing up the * anon_vma if they are the last user on release */ - atomic_t external_refcount; -#endif + atomic_t refcount; + /* * NOTE: the LSB of the head.next is set by * mm_take_all_locks() _after_ taking the above lock. So the @@ -71,42 +68,19 @@ struct anon_vma_chain { }; #ifdef CONFIG_MMU -#if defined(CONFIG_KSM) || defined(CONFIG_MIGRATION) -static inline void anonvma_external_refcount_init(struct anon_vma *anon_vma) -{ - atomic_set(&anon_vma->external_refcount, 0); -} - -static inline int anonvma_external_refcount(struct anon_vma *anon_vma) -{ - return atomic_read(&anon_vma->external_refcount); -} - static inline void get_anon_vma(struct anon_vma *anon_vma) { - atomic_inc(&anon_vma->external_refcount); + atomic_inc(&anon_vma->refcount); } -void drop_anon_vma(struct anon_vma *); -#else -static inline void anonvma_external_refcount_init(struct anon_vma *anon_vma) -{ -} +void __put_anon_vma(struct anon_vma *anon_vma); -static inline int anonvma_external_refcount(struct anon_vma *anon_vma) -{ - return 0; -} - -static inline void get_anon_vma(struct anon_vma *anon_vma) +static inline void put_anon_vma(struct anon_vma *anon_vma) { + if (atomic_dec_and_test(&anon_vma->refcount)) + __put_anon_vma(anon_vma); } -static inline void drop_anon_vma(struct anon_vma *anon_vma) -{ -} -#endif /* CONFIG_KSM */ - static inline struct anon_vma *page_anon_vma(struct page *page) { if (((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != @@ -148,7 +122,6 @@ void unlink_anon_vmas(struct vm_area_struct *); int anon_vma_clone(struct vm_area_struct *, struct vm_area_struct *); int anon_vma_fork(struct vm_area_struct *, struct vm_area_struct *); void __anon_vma_link(struct vm_area_struct *); -void anon_vma_free(struct anon_vma *); static inline void anon_vma_merge(struct vm_area_struct *vma, struct vm_area_struct *next) @@ -157,6 +130,8 @@ static inline void anon_vma_merge(struct vm_area_struct *vma, unlink_anon_vmas(next); } +struct anon_vma *page_get_anon_vma(struct page *page); + /* * rmap interfaces called when adding or removing pte of page */ |