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
8typedef struct page *new_page_t(struct page *, unsigned long private, int **);
9
10#ifdef CONFIG_MIGRATION
11/* Check if a vma is migratable */
12static 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
28extern int isolate_lru_page(struct page *p, struct list_head *pagelist);
29extern int putback_lru_pages(struct list_head *l);
30extern int migrate_page(struct address_space *,
31			struct page *, struct page *);
32extern int migrate_pages(struct list_head *l, new_page_t x, unsigned long);
33
34extern int fail_migrate_page(struct address_space *,
35			struct page *, struct page *);
36
37extern int migrate_prep(void);
38extern int migrate_vmas(struct mm_struct *mm,
39		const nodemask_t *from, const nodemask_t *to,
40		unsigned long flags);
41#else
42static inline int vma_migratable(struct vm_area_struct *vma)
43					{ return 0; }
44
45static inline int isolate_lru_page(struct page *p, struct list_head *list)
46					{ return -ENOSYS; }
47static inline int putback_lru_pages(struct list_head *l) { return 0; }
48static inline int migrate_pages(struct list_head *l, new_page_t x,
49		unsigned long private) { return -ENOSYS; }
50
51static inline int migrate_pages_to(struct list_head *pagelist,
52			struct vm_area_struct *vma, int dest) { return 0; }
53
54static inline int migrate_prep(void) { return -ENOSYS; }
55
56static 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 */
69