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
};
#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) !=
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)
unlink_anon_vmas(next);
}
+struct anon_vma *page_get_anon_vma(struct page *page);
+
/*
* rmap interfaces called when adding or removing pte of page
*/