diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/swap.h | 7 | ||||
| -rw-r--r-- | include/linux/swapops.h | 53 |
2 files changed, 60 insertions, 0 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index cd28ad206dae..7cee73ef4f15 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -28,7 +28,14 @@ static inline int current_is_kswapd(void) * the type/offset into the pte as 5/27 as well. */ #define MAX_SWAPFILES_SHIFT 5 +#ifndef CONFIG_MIGRATION #define MAX_SWAPFILES (1 << MAX_SWAPFILES_SHIFT) +#else +/* Use last two entries for page migration swap entries */ +#define MAX_SWAPFILES ((1 << MAX_SWAPFILES_SHIFT)-2) +#define SWP_MIGRATION_READ MAX_SWAPFILES +#define SWP_MIGRATION_WRITE (MAX_SWAPFILES + 1) +#endif /* * Magic header for a swap area. The first part of the union is diff --git a/include/linux/swapops.h b/include/linux/swapops.h index 87b9d14c710d..ec639aa3a1d3 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -67,3 +67,56 @@ static inline pte_t swp_entry_to_pte(swp_entry_t entry) BUG_ON(pte_file(__swp_entry_to_pte(arch_entry))); return __swp_entry_to_pte(arch_entry); } + +#ifdef CONFIG_MIGRATION +static inline swp_entry_t make_migration_entry(struct page *page, int write) +{ + BUG_ON(!PageLocked(page)); + return swp_entry(write ? SWP_MIGRATION_WRITE : SWP_MIGRATION_READ, + page_to_pfn(page)); +} + +static inline int is_migration_entry(swp_entry_t entry) +{ + return unlikely(swp_type(entry) == SWP_MIGRATION_READ || + swp_type(entry) == SWP_MIGRATION_WRITE); +} + +static inline int is_write_migration_entry(swp_entry_t entry) +{ + return unlikely(swp_type(entry) == SWP_MIGRATION_WRITE); +} + +static inline struct page *migration_entry_to_page(swp_entry_t entry) +{ + struct page *p = pfn_to_page(swp_offset(entry)); + /* + * Any use of migration entries may only occur while the + * corresponding page is locked + */ + BUG_ON(!PageLocked(p)); + return p; +} + +static inline void make_migration_entry_read(swp_entry_t *entry) +{ + *entry = swp_entry(SWP_MIGRATION_READ, swp_offset(*entry)); +} + +extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, + unsigned long address); +#else + +#define make_migration_entry(page, write) swp_entry(0, 0) +#define is_migration_entry(swp) 0 +#define migration_entry_to_page(swp) NULL +static inline void make_migration_entry_read(swp_entry_t *entryp) { } +static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, + unsigned long address) { } +static inline int is_write_migration_entry(swp_entry_t entry) +{ + return 0; +} + +#endif + |