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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - include/linux/rmap.h
4 * Declarations for Reverse Mapping functions in mm/rmap.c
7 #include <linux/list.h>
8 #include <linux/slab.h>
10 #include <linux/spinlock.h>
11 #include <linux/memcontrol.h>
14 * The anon_vma heads a list of private "related" vmas, to scan if
15 * an anonymous page pointing to this anon_vma needs to be unmapped:
16 * the vmas on the list will be related by forking, or by splitting.
18 * Since vmas come and go as they are split and merged (particularly
19 * in mprotect), the mapping field of an anonymous page cannot point
20 * directly to a vma: instead it points to an anon_vma, on whose list
21 * the related vmas can be easily linked or unlinked.
23 * After unlinking the last vma on the list, we must garbage collect
24 * the anon_vma object itself: we're guaranteed no page can be
25 * pointing to this anon_vma once its vma list is empty.
28 spinlock_t lock
; /* Serialize access to vma list */
30 * NOTE: the LSB of the head.next is set by
31 * mm_take_all_locks() _after_ taking the above lock. So the
32 * head must only be read/written after taking the above lock
33 * to be sure to see a valid next pointer. The LSB bit itself
34 * is serialized by a system wide lock only visible to
35 * mm_take_all_locks() (mm_all_locks_mutex).
37 struct list_head head
; /* List of private "related" vmas */
42 static inline void anon_vma_lock(struct vm_area_struct
*vma
)
44 struct anon_vma
*anon_vma
= vma
->anon_vma
;
46 spin_lock(&anon_vma
->lock
);
49 static inline void anon_vma_unlock(struct vm_area_struct
*vma
)
51 struct anon_vma
*anon_vma
= vma
->anon_vma
;
53 spin_unlock(&anon_vma
->lock
);
57 * anon_vma helper functions.
59 void anon_vma_init(void); /* create anon_vma_cachep */
60 int anon_vma_prepare(struct vm_area_struct
*);
61 void __anon_vma_merge(struct vm_area_struct
*, struct vm_area_struct
*);
62 void anon_vma_unlink(struct vm_area_struct
*);
63 void anon_vma_link(struct vm_area_struct
*);
64 void __anon_vma_link(struct vm_area_struct
*);
67 * rmap interfaces called when adding or removing pte of page
69 void page_add_anon_rmap(struct page
*, struct vm_area_struct
*, unsigned long);
70 void page_add_new_anon_rmap(struct page
*, struct vm_area_struct
*, unsigned long);
71 void page_add_file_rmap(struct page
*);
72 void page_remove_rmap(struct page
*);
74 #ifdef CONFIG_DEBUG_VM
75 void page_dup_rmap(struct page
*page
, struct vm_area_struct
*vma
, unsigned long address
);
77 static inline void page_dup_rmap(struct page
*page
, struct vm_area_struct
*vma
, unsigned long address
)
79 atomic_inc(&page
->_mapcount
);
84 * Called from mm/vmscan.c to handle paging out
86 int page_referenced(struct page
*, int is_locked
, struct mem_cgroup
*cnt
);
87 int try_to_unmap(struct page
*, int ignore_refs
);
90 * Called from mm/filemap_xip.c to unmap empty zero page
92 pte_t
*page_check_address(struct page
*, struct mm_struct
*,
93 unsigned long, spinlock_t
**, int);
96 * Used by swapoff to help locate where page is expected in vma.
98 unsigned long page_address_in_vma(struct page
*, struct vm_area_struct
*);
101 * Cleans the PTEs of shared mappings.
102 * (and since clean PTEs should also be readonly, write protects them too)
104 * returns the number of cleaned PTEs.
106 int page_mkclean(struct page
*);
108 #ifdef CONFIG_UNEVICTABLE_LRU
110 * called in munlock()/munmap() path to check for other vmas holding
113 int try_to_munlock(struct page
*);
115 static inline int try_to_munlock(struct page
*page
)
117 return 0; /* a.k.a. SWAP_SUCCESS */
121 #else /* !CONFIG_MMU */
123 #define anon_vma_init() do {} while (0)
124 #define anon_vma_prepare(vma) (0)
125 #define anon_vma_link(vma) do {} while (0)
127 #define page_referenced(page,l,cnt) TestClearPageReferenced(page)
128 #define try_to_unmap(page, refs) SWAP_FAIL
130 static inline int page_mkclean(struct page
*page
)
136 #endif /* CONFIG_MMU */
139 * Return values of try_to_unmap
141 #define SWAP_SUCCESS 0
146 #endif /* _LINUX_RMAP_H */