mm/rmap, migration: Make rmap_walk_anon() and try_to_unmap_anon() more scalable
[linux-3.10.git] / include / linux / huge_mm.h
1 #ifndef _LINUX_HUGE_MM_H
2 #define _LINUX_HUGE_MM_H
3
4 extern int do_huge_pmd_anonymous_page(struct mm_struct *mm,
5                                       struct vm_area_struct *vma,
6                                       unsigned long address, pmd_t *pmd,
7                                       unsigned int flags);
8 extern int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
9                          pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
10                          struct vm_area_struct *vma);
11 extern int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
12                                unsigned long address, pmd_t *pmd,
13                                pmd_t orig_pmd);
14 extern struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
15                                           unsigned long addr,
16                                           pmd_t *pmd,
17                                           unsigned int flags);
18 extern int zap_huge_pmd(struct mmu_gather *tlb,
19                         struct vm_area_struct *vma,
20                         pmd_t *pmd, unsigned long addr);
21 extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
22                         unsigned long addr, unsigned long end,
23                         unsigned char *vec);
24 extern int move_huge_pmd(struct vm_area_struct *vma,
25                          struct vm_area_struct *new_vma,
26                          unsigned long old_addr,
27                          unsigned long new_addr, unsigned long old_end,
28                          pmd_t *old_pmd, pmd_t *new_pmd);
29 extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
30                         unsigned long addr, pgprot_t newprot,
31                         int prot_numa);
32
33 enum transparent_hugepage_flag {
34         TRANSPARENT_HUGEPAGE_FLAG,
35         TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
36         TRANSPARENT_HUGEPAGE_DEFRAG_FLAG,
37         TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
38         TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
39 #ifdef CONFIG_DEBUG_VM
40         TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
41 #endif
42 };
43
44 enum page_check_address_pmd_flag {
45         PAGE_CHECK_ADDRESS_PMD_FLAG,
46         PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG,
47         PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG,
48 };
49 extern pmd_t *page_check_address_pmd(struct page *page,
50                                      struct mm_struct *mm,
51                                      unsigned long address,
52                                      enum page_check_address_pmd_flag flag);
53
54 #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
55 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
56
57 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
58 #define HPAGE_PMD_SHIFT HPAGE_SHIFT
59 #define HPAGE_PMD_MASK HPAGE_MASK
60 #define HPAGE_PMD_SIZE HPAGE_SIZE
61
62 extern bool is_vma_temporary_stack(struct vm_area_struct *vma);
63
64 #define transparent_hugepage_enabled(__vma)                             \
65         ((transparent_hugepage_flags &                                  \
66           (1<<TRANSPARENT_HUGEPAGE_FLAG) ||                             \
67           (transparent_hugepage_flags &                                 \
68            (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) &&                   \
69            ((__vma)->vm_flags & VM_HUGEPAGE))) &&                       \
70          !((__vma)->vm_flags & VM_NOHUGEPAGE) &&                        \
71          !is_vma_temporary_stack(__vma))
72 #define transparent_hugepage_defrag(__vma)                              \
73         ((transparent_hugepage_flags &                                  \
74           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) ||                     \
75          (transparent_hugepage_flags &                                  \
76           (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG) &&             \
77           (__vma)->vm_flags & VM_HUGEPAGE))
78 #ifdef CONFIG_DEBUG_VM
79 #define transparent_hugepage_debug_cow()                                \
80         (transparent_hugepage_flags &                                   \
81          (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
82 #else /* CONFIG_DEBUG_VM */
83 #define transparent_hugepage_debug_cow() 0
84 #endif /* CONFIG_DEBUG_VM */
85
86 extern unsigned long transparent_hugepage_flags;
87 extern int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
88                           pmd_t *dst_pmd, pmd_t *src_pmd,
89                           struct vm_area_struct *vma,
90                           unsigned long addr, unsigned long end);
91 extern int handle_pte_fault(struct mm_struct *mm,
92                             struct vm_area_struct *vma, unsigned long address,
93                             pte_t *pte, pmd_t *pmd, unsigned int flags);
94 extern int split_huge_page(struct page *page);
95 extern void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd);
96 #define split_huge_page_pmd(__mm, __pmd)                                \
97         do {                                                            \
98                 pmd_t *____pmd = (__pmd);                               \
99                 if (unlikely(pmd_trans_huge(*____pmd)))                 \
100                         __split_huge_page_pmd(__mm, ____pmd);           \
101         }  while (0)
102 #define wait_split_huge_page(__anon_vma, __pmd)                         \
103         do {                                                            \
104                 pmd_t *____pmd = (__pmd);                               \
105                 anon_vma_lock_write(__anon_vma);                        \
106                 anon_vma_unlock(__anon_vma);                            \
107                 BUG_ON(pmd_trans_splitting(*____pmd) ||                 \
108                        pmd_trans_huge(*____pmd));                       \
109         } while (0)
110 #if HPAGE_PMD_ORDER > MAX_ORDER
111 #error "hugepages can't be allocated by the buddy allocator"
112 #endif
113 extern int hugepage_madvise(struct vm_area_struct *vma,
114                             unsigned long *vm_flags, int advice);
115 extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
116                                     unsigned long start,
117                                     unsigned long end,
118                                     long adjust_next);
119 extern int __pmd_trans_huge_lock(pmd_t *pmd,
120                                  struct vm_area_struct *vma);
121 /* mmap_sem must be held on entry */
122 static inline int pmd_trans_huge_lock(pmd_t *pmd,
123                                       struct vm_area_struct *vma)
124 {
125         VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
126         if (pmd_trans_huge(*pmd))
127                 return __pmd_trans_huge_lock(pmd, vma);
128         else
129                 return 0;
130 }
131 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
132                                          unsigned long start,
133                                          unsigned long end,
134                                          long adjust_next)
135 {
136         if (!vma->anon_vma || vma->vm_ops)
137                 return;
138         __vma_adjust_trans_huge(vma, start, end, adjust_next);
139 }
140 static inline int hpage_nr_pages(struct page *page)
141 {
142         if (unlikely(PageTransHuge(page)))
143                 return HPAGE_PMD_NR;
144         return 1;
145 }
146 static inline struct page *compound_trans_head(struct page *page)
147 {
148         if (PageTail(page)) {
149                 struct page *head;
150                 head = page->first_page;
151                 smp_rmb();
152                 /*
153                  * head may be a dangling pointer.
154                  * __split_huge_page_refcount clears PageTail before
155                  * overwriting first_page, so if PageTail is still
156                  * there it means the head pointer isn't dangling.
157                  */
158                 if (PageTail(page))
159                         return head;
160         }
161         return page;
162 }
163
164 extern int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
165                                 unsigned long addr, pmd_t pmd, pmd_t *pmdp);
166
167 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
168 #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
169 #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
170 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
171
172 #define hpage_nr_pages(x) 1
173
174 #define transparent_hugepage_enabled(__vma) 0
175
176 #define transparent_hugepage_flags 0UL
177 static inline int split_huge_page(struct page *page)
178 {
179         return 0;
180 }
181 #define split_huge_page_pmd(__mm, __pmd)        \
182         do { } while (0)
183 #define wait_split_huge_page(__anon_vma, __pmd) \
184         do { } while (0)
185 #define compound_trans_head(page) compound_head(page)
186 static inline int hugepage_madvise(struct vm_area_struct *vma,
187                                    unsigned long *vm_flags, int advice)
188 {
189         BUG();
190         return 0;
191 }
192 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
193                                          unsigned long start,
194                                          unsigned long end,
195                                          long adjust_next)
196 {
197 }
198 static inline int pmd_trans_huge_lock(pmd_t *pmd,
199                                       struct vm_area_struct *vma)
200 {
201         return 0;
202 }
203
204 static inline int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
205                                         unsigned long addr, pmd_t pmd, pmd_t *pmdp)
206 {
207         return 0;
208 }
209
210 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
211
212 #endif /* _LINUX_HUGE_MM_H */