include/linux/migrate.h

   1 #ifndef _LINUX_MIGRATE_H
   2 #define _LINUX_MIGRATE_H
   3
   4 #include <linux/mm.h>
   5 #include <linux/mempolicy.h>
   6 #include <linux/pagemap.h>
   7
   8 typedef struct page *new_page_t(struct page *, unsigned long private, int **);
   9
  10 #ifdef CONFIG_MIGRATION
  11 /* Check if a vma is migratable */
  12 static inline int vma_migratable(struct vm_area_struct *vma)
  13 {
  14         if (vma->vm_flags & (VM_IO|VM_HUGETLB|VM_PFNMAP|VM_RESERVED))
  15                 return 0;
  16         /*
  17          * Migration allocates pages in the highest zone. If we cannot
  18          * do so then migration (at least from node to node) is not
  19          * possible.
  20          */
  21         if (vma->vm_file &&
  22                 gfp_zone(mapping_gfp_mask(vma->vm_file->f_mapping))
  23                                                                 < policy_zone)
  24                         return 0;
  25         return 1;
  26 }
  27
  28 extern int isolate_lru_page(struct page *p, struct list_head *pagelist);
  29 extern int putback_lru_pages(struct list_head *l);
  30 extern int migrate_page(struct address_space *,
  31                         struct page *, struct page *);
  32 extern int migrate_pages(struct list_head *l, new_page_t x, unsigned long);
  33
  34 extern int fail_migrate_page(struct address_space *,
  35                         struct page *, struct page *);
  36
  37 extern int migrate_prep(void);
  38 extern int migrate_vmas(struct mm_struct *mm,
  39                 const nodemask_t *from, const nodemask_t *to,
  40                 unsigned long flags);
  41 #else
  42 static inline int vma_migratable(struct vm_area_struct *vma)
  43                                         { return 0; }
  44
  45 static inline int isolate_lru_page(struct page *p, struct list_head *list)
  46                                         { return -ENOSYS; }
  47 static inline int putback_lru_pages(struct list_head *l) { return 0; }
  48 static inline int migrate_pages(struct list_head *l, new_page_t x,
  49                 unsigned long private) { return -ENOSYS; }
  50
  51 static inline int migrate_pages_to(struct list_head *pagelist,
  52                         struct vm_area_struct *vma, int dest) { return 0; }
  53
  54 static inline int migrate_prep(void) { return -ENOSYS; }
  55
  56 static inline int migrate_vmas(struct mm_struct *mm,
  57                 const nodemask_t *from, const nodemask_t *to,
  58                 unsigned long flags)
  59 {
  60         return -ENOSYS;
  61 }
  62
  63 /* Possible settings for the migrate_page() method in address_operations */
  64 #define migrate_page NULL
  65 #define fail_migrate_page NULL
  66
  67 #endif /* CONFIG_MIGRATION */
  68 #endif /* _LINUX_MIGRATE_H */