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#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 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_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_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 */