[linux-block.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.
					   */
enum migrate_reason {
	MR_COMPACTION,
	MR_MEMORY_FAILURE,
	MR_MEMORY_HOTPLUG,
	MR_SYSCALL,		/* also applies to cpusets */
	MR_MEMPOLICY_MBIND,
	MR_NUMA_MISPLACED,
	MR_CMA
};

#ifdef CONFIG_MIGRATION

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

#ifdef CONFIG_NUMA_BALANCING
extern int migrate_misplaced_page(struct page *page, int node);
extern int migrate_misplaced_page(struct page *page, int node);
extern bool migrate_ratelimited(int node);
#else
static inline int migrate_misplaced_page(struct page *page, int node)
{
	return -EAGAIN; /* can't migrate now */
}
static inline bool migrate_ratelimited(int node)
{
	return false;
}
#endif /* CONFIG_NUMA_BALANCING */

#if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
			struct vm_area_struct *vma,
			pmd_t *pmd, pmd_t entry,
			unsigned long address,
			struct page *page, int node);
#else
static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
			struct vm_area_struct *vma,
			pmd_t *pmd, pmd_t entry,
			unsigned long address,
			struct page *page, int node)
{
	return -EAGAIN;
}
#endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/

#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	*/
7b2a2d4a MG	26	enum migrate_reason {
	27	MR_COMPACTION,
	28	MR_MEMORY_FAILURE,
	29	MR_MEMORY_HOTPLUG,
	30	MR_SYSCALL, /* also applies to cpusets */
	31	MR_MEMPOLICY_MBIND,
7039e1db	32	MR_NUMA_MISPLACED,
7b2a2d4a MG	33	MR_CMA
7b2a2d4a MG	34	};
78bd5209	35
906e0be1	36	#ifdef CONFIG_MIGRATION
64cdd548	37
e13861d8	38	extern void putback_lru_pages(struct list_head *l);
5733c7d1	39	extern void putback_movable_pages(struct list_head *l);
2d1db3b1	40	extern int migrate_page(struct address_space *,
a6bc32b8	41	struct page , struct page , enum migrate_mode);
62b61f61	42	extern int migrate_pages(struct list_head *l, new_page_t x,
9c620e2b	43	unsigned long private, enum migrate_mode mode, int reason);
189ebff2	44	extern int migrate_huge_page(struct page *, new_page_t x,
9c620e2b	45	unsigned long private, enum migrate_mode mode);
95a402c3	46
2d1db3b1 CL	47	extern int fail_migrate_page(struct address_space *,
2d1db3b1 CL	48	struct page , struct page );
b20a3503 CL	49
b20a3503 CL	50	extern int migrate_prep(void);
748446bb	51	extern int migrate_prep_local(void);
7b2259b3 CL	52	extern int migrate_vmas(struct mm_struct *mm,
	53	const nodemask_t from, const nodemask_t to,
	54	unsigned long flags);
290408d4 NH	55	extern void migrate_page_copy(struct page newpage, struct page page);
	56	extern int migrate_huge_page_move_mapping(struct address_space *mapping,
	57	struct page newpage, struct page page);
b20a3503	58	#else
64cdd548	59
e13861d8	60	static inline void putback_lru_pages(struct list_head *l) {}
5733c7d1	61	static inline void putback_movable_pages(struct list_head *l) {}
95a402c3	62	static inline int migrate_pages(struct list_head *l, new_page_t x,
9c620e2b HD	63	unsigned long private, enum migrate_mode mode, int reason)
9c620e2b HD	64	{ return -ENOSYS; }
189ebff2	65	static inline int migrate_huge_page(struct page *page, new_page_t x,
9c620e2b HD	66	unsigned long private, enum migrate_mode mode)
9c620e2b HD	67	{ return -ENOSYS; }
9bf9e89c	68
b20a3503	69	static inline int migrate_prep(void) { return -ENOSYS; }
748446bb	70	static inline int migrate_prep_local(void) { return -ENOSYS; }
b20a3503	71
7b2259b3 CL	72	static inline int migrate_vmas(struct mm_struct *mm,
	73	const nodemask_t from, const nodemask_t to,
	74	unsigned long flags)
	75	{
	76	return -ENOSYS;
	77	}
	78
290408d4 NH	79	static inline void migrate_page_copy(struct page *newpage,
	80	struct page *page) {}
	81
6f39ce05	82	static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
290408d4 NH	83	struct page newpage, struct page page)
	84	{
	85	return -ENOSYS;
	86	}
	87
b20a3503 CL	88	/* Possible settings for the migrate_page() method in address_operations */
	89	#define migrate_page NULL
	90	#define fail_migrate_page NULL
	91
	92	#endif /* CONFIG_MIGRATION */
7039e1db PZ	93
	94	#ifdef CONFIG_NUMA_BALANCING
	95	extern int migrate_misplaced_page(struct page *page, int node);
e14808b4 MG	96	extern int migrate_misplaced_page(struct page *page, int node);
e14808b4 MG	97	extern bool migrate_ratelimited(int node);
7039e1db PZ	98	#else
	99	static inline int migrate_misplaced_page(struct page *page, int node)
	100	{
	101	return -EAGAIN; /* can't migrate now */
	102	}
e14808b4 MG	103	static inline bool migrate_ratelimited(int node)
	104	{
	105	return false;
	106	}
220018d3	107	#endif /* CONFIG_NUMA_BALANCING */
b32967ff	108
220018d3 MG	109	#if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
	110	extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
	111	struct vm_area_struct *vma,
	112	pmd_t *pmd, pmd_t entry,
	113	unsigned long address,
	114	struct page *page, int node);
	115	#else
b32967ff MG	116	static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
	117	struct vm_area_struct *vma,
	118	pmd_t *pmd, pmd_t entry,
	119	unsigned long address,
	120	struct page *page, int node)
	121	{
	122	return -EAGAIN;
	123	}
220018d3	124	#endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
7039e1db	125
b20a3503	126	#endif /* _LINUX_MIGRATE_H */