[deliverable/linux.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_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 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);
extern int migrate_page_move_mapping(struct address_space *mapping,
		struct page *newpage, struct page *page,
		struct buffer_head *head, enum migrate_mode mode,
		int extra_count);
#else

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_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 bool pmd_trans_migrating(pmd_t pmd);
extern void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd);
extern int migrate_misplaced_page(struct page *page,
				  struct vm_area_struct *vma, int node);
extern bool migrate_ratelimited(int node);
#else
static inline bool pmd_trans_migrating(pmd_t pmd)
{
	return false;
}
static inline void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd)
{
}
static inline int migrate_misplaced_page(struct page *page,
					 struct vm_area_struct *vma, 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
5733c7d1	38	extern void putback_movable_pages(struct list_head *l);
2d1db3b1	39	extern int migrate_page(struct address_space *,
a6bc32b8	40	struct page , struct page , enum migrate_mode);
62b61f61	41	extern int migrate_pages(struct list_head *l, new_page_t x,
9c620e2b	42	unsigned long private, enum migrate_mode mode, int reason);
95a402c3	43
2d1db3b1 CL	44	extern int fail_migrate_page(struct address_space *,
2d1db3b1 CL	45	struct page , struct page );
b20a3503 CL	46
b20a3503 CL	47	extern int migrate_prep(void);
748446bb	48	extern int migrate_prep_local(void);
7b2259b3 CL	49	extern int migrate_vmas(struct mm_struct *mm,
	50	const nodemask_t from, const nodemask_t to,
	51	unsigned long flags);
290408d4 NH	52	extern void migrate_page_copy(struct page newpage, struct page page);
	53	extern int migrate_huge_page_move_mapping(struct address_space *mapping,
	54	struct page newpage, struct page page);
36bc08cc GZ	55	extern int migrate_page_move_mapping(struct address_space *mapping,
36bc08cc GZ	56	struct page newpage, struct page page,
8e321fef BL	57	struct buffer_head *head, enum migrate_mode mode,
8e321fef BL	58	int extra_count);
b20a3503	59	#else
64cdd548	60
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; }
9bf9e89c	65
b20a3503	66	static inline int migrate_prep(void) { return -ENOSYS; }
748446bb	67	static inline int migrate_prep_local(void) { return -ENOSYS; }
b20a3503	68
7b2259b3 CL	69	static inline int migrate_vmas(struct mm_struct *mm,
	70	const nodemask_t from, const nodemask_t to,
	71	unsigned long flags)
	72	{
	73	return -ENOSYS;
	74	}
	75
290408d4 NH	76	static inline void migrate_page_copy(struct page *newpage,
	77	struct page *page) {}
	78
6f39ce05	79	static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
290408d4 NH	80	struct page newpage, struct page page)
	81	{
	82	return -ENOSYS;
	83	}
	84
b20a3503 CL	85	/* Possible settings for the migrate_page() method in address_operations */
	86	#define migrate_page NULL
	87	#define fail_migrate_page NULL
	88
	89	#endif /* CONFIG_MIGRATION */
7039e1db PZ	90
7039e1db PZ	91	#ifdef CONFIG_NUMA_BALANCING
de466bd6 MG	92	extern bool pmd_trans_migrating(pmd_t pmd);
de466bd6 MG	93	extern void wait_migrate_huge_page(struct anon_vma anon_vma, pmd_t pmd);
1bc115d8 MG	94	extern int migrate_misplaced_page(struct page *page,
1bc115d8 MG	95	struct vm_area_struct *vma, int node);
e14808b4	96	extern bool migrate_ratelimited(int node);
7039e1db	97	#else
de466bd6 MG	98	static inline bool pmd_trans_migrating(pmd_t pmd)
	99	{
	100	return false;
	101	}
	102	static inline void wait_migrate_huge_page(struct anon_vma anon_vma, pmd_t pmd)
	103	{
	104	}
1bc115d8 MG	105	static inline int migrate_misplaced_page(struct page *page,
1bc115d8 MG	106	struct vm_area_struct *vma, int node)
7039e1db PZ	107	{
	108	return -EAGAIN; /* can't migrate now */
	109	}
e14808b4 MG	110	static inline bool migrate_ratelimited(int node)
	111	{
	112	return false;
	113	}
220018d3	114	#endif /* CONFIG_NUMA_BALANCING */
b32967ff	115
220018d3 MG	116	#if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
	117	extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
	118	struct vm_area_struct *vma,
	119	pmd_t *pmd, pmd_t entry,
	120	unsigned long address,
	121	struct page *page, int node);
	122	#else
b32967ff MG	123	static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
	124	struct vm_area_struct *vma,
	125	pmd_t *pmd, pmd_t entry,
	126	unsigned long address,
	127	struct page *page, int node)
	128	{
	129	return -EAGAIN;
	130	}
220018d3	131	#endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
7039e1db	132
b20a3503	133	#endif /* _LINUX_MIGRATE_H */