typedef struct page *new_page_t(struct page *, unsigned long private, int **);
#ifdef CONFIG_MIGRATION
-#define PAGE_MIGRATION 1
extern void putback_lru_pages(struct list_head *l);
extern int migrate_page(struct address_space *,
extern int migrate_huge_page_move_mapping(struct address_space *mapping,
struct page *newpage, struct page *page);
#else
-#define PAGE_MIGRATION 0
static inline void putback_lru_pages(struct list_head *l) {}
static inline int migrate_pages(struct list_head *l, new_page_t x,