[mirror_ubuntu-artful-kernel.git] / include / linux / migrate.h

#ifndef _LINUX_MIGRATE_H
#define _LINUX_MIGRATE_H

#include <linux/mm.h>
#include <linux/mempolicy.h>
#include <linux/migrate_mode.h>

typedef struct page *new_page_t(struct page *, unsigned long private, int **);

/*
 * Return values from addresss_space_operations.migratepage():
 * - negative errno on page migration failure;
 * - zero on page migration success;
 *
 * The balloon page migration introduces this special case where a 'distinct'
 * return code is used to flag a successful page migration to unmap_and_move().
 * This approach is necessary because page migration can race against balloon
 * deflation procedure, and for such case we could introduce a nasty page leak
 * if a successfully migrated balloon page gets released concurrently with
 * migration's unmap_and_move() wrap-up steps.
 */
#define MIGRATEPAGE_SUCCESS		0
#define MIGRATEPAGE_BALLOON_SUCCESS	1 /* special ret code for balloon page
					   * sucessful migration case.
					   */

#ifdef CONFIG_MIGRATION

extern void putback_lru_pages(struct list_head *l);
extern int migrate_page(struct address_space *,
			struct page *, struct page *, enum migrate_mode);
extern int migrate_pages(struct list_head *l, new_page_t x,
			unsigned long private, bool offlining,
			enum migrate_mode mode);
extern int migrate_huge_page(struct page *, new_page_t x,
			unsigned long private, bool offlining,
			enum migrate_mode mode);

extern int fail_migrate_page(struct address_space *,
			struct page *, struct page *);

extern int migrate_prep(void);
extern int migrate_prep_local(void);
extern int migrate_vmas(struct mm_struct *mm,
		const nodemask_t *from, const nodemask_t *to,
		unsigned long flags);
extern void migrate_page_copy(struct page *newpage, struct page *page);
extern int migrate_huge_page_move_mapping(struct address_space *mapping,
				  struct page *newpage, struct page *page);
#else

static inline void putback_lru_pages(struct list_head *l) {}
static inline int migrate_pages(struct list_head *l, new_page_t x,
		unsigned long private, bool offlining,
		enum migrate_mode mode) { return -ENOSYS; }
static inline int migrate_huge_page(struct page *page, new_page_t x,
		unsigned long private, bool offlining,
		enum migrate_mode mode) { return -ENOSYS; }

static inline int migrate_prep(void) { return -ENOSYS; }
static inline int migrate_prep_local(void) { return -ENOSYS; }

static inline int migrate_vmas(struct mm_struct *mm,
		const nodemask_t *from, const nodemask_t *to,
		unsigned long flags)
{
	return -ENOSYS;
}

static inline void migrate_page_copy(struct page *newpage,
				     struct page *page) {}

static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
				  struct page *newpage, struct page *page)
{
	return -ENOSYS;
}

/* Possible settings for the migrate_page() method in address_operations */
#define migrate_page NULL
#define fail_migrate_page NULL

#endif /* CONFIG_MIGRATION */
#endif /* _LINUX_MIGRATE_H */
Commit	Line	Data
b20a3503 CL	1	#ifndef _LINUX_MIGRATE_H
	2	#define _LINUX_MIGRATE_H
	3
b20a3503	4	#include <linux/mm.h>
906e0be1	5	#include <linux/mempolicy.h>
6536e312	6	#include <linux/migrate_mode.h>
b20a3503	7
742755a1	8	typedef struct page new_page_t(struct page , unsigned long private, int **);
95a402c3	9
78bd5209 RA	10	/*
	11	* Return values from addresss_space_operations.migratepage():
	12	* - negative errno on page migration failure;
	13	* - zero on page migration success;
18468d93 RA	14	*
	15	* The balloon page migration introduces this special case where a 'distinct'
	16	* return code is used to flag a successful page migration to unmap_and_move().
	17	* This approach is necessary because page migration can race against balloon
	18	* deflation procedure, and for such case we could introduce a nasty page leak
	19	* if a successfully migrated balloon page gets released concurrently with
	20	* migration's unmap_and_move() wrap-up steps.
78bd5209 RA	21	*/
78bd5209 RA	22	#define MIGRATEPAGE_SUCCESS 0
18468d93 RA	23	#define MIGRATEPAGE_BALLOON_SUCCESS 1 /* special ret code for balloon page
	24	* sucessful migration case.
	25	*/
78bd5209	26
906e0be1	27	#ifdef CONFIG_MIGRATION
64cdd548	28
e13861d8	29	extern void putback_lru_pages(struct list_head *l);
2d1db3b1	30	extern int migrate_page(struct address_space *,
a6bc32b8	31	struct page , struct page , enum migrate_mode);
62b61f61	32	extern int migrate_pages(struct list_head *l, new_page_t x,
7f0f2496	33	unsigned long private, bool offlining,
a6bc32b8	34	enum migrate_mode mode);
189ebff2	35	extern int migrate_huge_page(struct page *, new_page_t x,
7f0f2496	36	unsigned long private, bool offlining,
a6bc32b8	37	enum migrate_mode mode);
95a402c3	38
2d1db3b1 CL	39	extern int fail_migrate_page(struct address_space *,
2d1db3b1 CL	40	struct page , struct page );
b20a3503 CL	41
b20a3503 CL	42	extern int migrate_prep(void);
748446bb	43	extern int migrate_prep_local(void);
7b2259b3 CL	44	extern int migrate_vmas(struct mm_struct *mm,
	45	const nodemask_t from, const nodemask_t to,
	46	unsigned long flags);
290408d4 NH	47	extern void migrate_page_copy(struct page newpage, struct page page);
	48	extern int migrate_huge_page_move_mapping(struct address_space *mapping,
	49	struct page newpage, struct page page);
b20a3503	50	#else
64cdd548	51
e13861d8	52	static inline void putback_lru_pages(struct list_head *l) {}
95a402c3	53	static inline int migrate_pages(struct list_head *l, new_page_t x,
7f0f2496	54	unsigned long private, bool offlining,
a6bc32b8	55	enum migrate_mode mode) { return -ENOSYS; }
189ebff2	56	static inline int migrate_huge_page(struct page *page, new_page_t x,
7f0f2496	57	unsigned long private, bool offlining,
a6bc32b8	58	enum migrate_mode mode) { return -ENOSYS; }
9bf9e89c	59
b20a3503	60	static inline int migrate_prep(void) { return -ENOSYS; }
748446bb	61	static inline int migrate_prep_local(void) { return -ENOSYS; }
b20a3503	62
7b2259b3 CL	63	static inline int migrate_vmas(struct mm_struct *mm,
	64	const nodemask_t from, const nodemask_t to,
	65	unsigned long flags)
	66	{
	67	return -ENOSYS;
	68	}
	69
290408d4 NH	70	static inline void migrate_page_copy(struct page *newpage,
	71	struct page *page) {}
	72
6f39ce05	73	static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
290408d4 NH	74	struct page newpage, struct page page)
	75	{
	76	return -ENOSYS;
	77	}
	78
b20a3503 CL	79	/* Possible settings for the migrate_page() method in address_operations */
	80	#define migrate_page NULL
	81	#define fail_migrate_page NULL
	82
	83	#endif /* CONFIG_MIGRATION */
	84	#endif /* _LINUX_MIGRATE_H */