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- #ifndef _LINUX_SWAP_H
- #define _LINUX_SWAP_H
- #include <linux/spinlock.h>
- #include <linux/linkage.h>
- #include <linux/mmzone.h>
- #include <linux/list.h>
- #include <linux/sched.h>
- #include <asm/atomic.h>
- #include <asm/page.h>
- struct notifier_block;
- struct bio;
- #define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */
- #define SWAP_FLAG_PRIO_MASK 0x7fff
- #define SWAP_FLAG_PRIO_SHIFT 0
- static inline int current_is_kswapd(void)
- {
- return current->flags & PF_KSWAPD;
- }
- /*
- * MAX_SWAPFILES defines the maximum number of swaptypes: things which can
- * be swapped to. The swap type and the offset into that swap type are
- * encoded into pte's and into pgoff_t's in the swapcache. Using five bits
- * for the type means that the maximum number of swapcache pages is 27 bits
- * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs
- * 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
- * what the swap magic looks like for the old (limited to 128MB)
- * swap area format, the second part of the union adds - in the
- * old reserved area - some extra information. Note that the first
- * kilobyte is reserved for boot loader or disk label stuff...
- *
- * Having the magic at the end of the PAGE_SIZE makes detecting swap
- * areas somewhat tricky on machines that support multiple page sizes.
- * For 2.5 we'll probably want to move the magic to just beyond the
- * bootbits...
- */
- union swap_header {
- struct {
- char reserved[PAGE_SIZE - 10];
- char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */
- } magic;
- struct {
- char bootbits[1024]; /* Space for disklabel etc. */
- __u32 version;
- __u32 last_page;
- __u32 nr_badpages;
- unsigned char sws_uuid[16];
- unsigned char sws_volume[16];
- __u32 padding[117];
- __u32 badpages[1];
- } info;
- };
- /* A swap entry has to fit into a "unsigned long", as
- * the entry is hidden in the "index" field of the
- * swapper address space.
- */
- typedef struct {
- unsigned long val;
- } swp_entry_t;
- /*
- * current->reclaim_state points to one of these when a task is running
- * memory reclaim
- */
- struct reclaim_state {
- unsigned long reclaimed_slab;
- };
- #ifdef __KERNEL__
- struct address_space;
- struct sysinfo;
- struct writeback_control;
- struct zone;
- /*
- * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of
- * disk blocks. A list of swap extents maps the entire swapfile. (Where the
- * term `swapfile' refers to either a blockdevice or an IS_REG file. Apart
- * from setup, they're handled identically.
- *
- * We always assume that blocks are of size PAGE_SIZE.
- */
- struct swap_extent {
- struct list_head list;
- pgoff_t start_page;
- pgoff_t nr_pages;
- sector_t start_block;
- };
- /*
- * Max bad pages in the new format..
- */
- #define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x)
- #define MAX_SWAP_BADPAGES \
- ((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int))
- enum {
- SWP_USED = (1 << 0), /* is slot in swap_info[] used? */
- SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */
- SWP_ACTIVE = (SWP_USED | SWP_WRITEOK),
- /* add others here before... */
- SWP_SCANNING = (1 << 8), /* refcount in scan_swap_map */
- };
- #define SWAP_CLUSTER_MAX 32
- #define SWAP_MAP_MAX 0x7fff
- #define SWAP_MAP_BAD 0x8000
- /*
- * The in-memory structure used to track swap areas.
- */
- struct swap_info_struct {
- unsigned int flags;
- int prio; /* swap priority */
- struct file *swap_file;
- struct block_device *bdev;
- struct list_head extent_list;
- struct swap_extent *curr_swap_extent;
- unsigned old_block_size;
- unsigned short * swap_map;
- unsigned int lowest_bit;
- unsigned int highest_bit;
- unsigned int cluster_next;
- unsigned int cluster_nr;
- unsigned int pages;
- unsigned int max;
- unsigned int inuse_pages;
- int next; /* next entry on swap list */
- };
- struct swap_list_t {
- int head; /* head of priority-ordered swapfile list */
- int next; /* swapfile to be used next */
- };
- /* Swap 50% full? Release swapcache more aggressively.. */
- #define vm_swap_full() (nr_swap_pages*2 < total_swap_pages)
- /* linux/mm/oom_kill.c */
- extern void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order);
- extern int register_oom_notifier(struct notifier_block *nb);
- extern int unregister_oom_notifier(struct notifier_block *nb);
- /* linux/mm/memory.c */
- extern void swapin_readahead(swp_entry_t, unsigned long, struct vm_area_struct *);
- /* linux/mm/page_alloc.c */
- extern unsigned long totalram_pages;
- extern unsigned long totalreserve_pages;
- extern long nr_swap_pages;
- extern unsigned int nr_free_buffer_pages(void);
- extern unsigned int nr_free_pagecache_pages(void);
- /* Definition of global_page_state not available yet */
- #define nr_free_pages() global_page_state(NR_FREE_PAGES)
- /* linux/mm/swap.c */
- extern void FASTCALL(lru_cache_add(struct page *));
- extern void FASTCALL(lru_cache_add_active(struct page *));
- extern void FASTCALL(activate_page(struct page *));
- extern void FASTCALL(mark_page_accessed(struct page *));
- extern void lru_add_drain(void);
- extern int lru_add_drain_all(void);
- extern int rotate_reclaimable_page(struct page *page);
- extern void swap_setup(void);
- /* linux/mm/vmscan.c */
- extern unsigned long try_to_free_pages(struct zone **, gfp_t);
- extern unsigned long shrink_all_memory(unsigned long nr_pages);
- extern int vm_swappiness;
- extern int remove_mapping(struct address_space *mapping, struct page *page);
- extern long vm_total_pages;
- #ifdef CONFIG_NUMA
- extern int zone_reclaim_mode;
- extern int sysctl_min_unmapped_ratio;
- extern int sysctl_min_slab_ratio;
- extern int zone_reclaim(struct zone *, gfp_t, unsigned int);
- #else
- #define zone_reclaim_mode 0
- static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order)
- {
- return 0;
- }
- #endif
- extern int kswapd_run(int nid);
- #ifdef CONFIG_MMU
- /* linux/mm/shmem.c */
- extern int shmem_unuse(swp_entry_t entry, struct page *page);
- #endif /* CONFIG_MMU */
- extern void swap_unplug_io_fn(struct backing_dev_info *, struct page *);
- #ifdef CONFIG_SWAP
- /* linux/mm/page_io.c */
- extern int swap_readpage(struct file *, struct page *);
- extern int swap_writepage(struct page *page, struct writeback_control *wbc);
- extern int end_swap_bio_read(struct bio *bio, unsigned int bytes_done, int err);
- /* linux/mm/swap_state.c */
- extern struct address_space swapper_space;
- #define total_swapcache_pages swapper_space.nrpages
- extern void show_swap_cache_info(void);
- extern int add_to_swap(struct page *, gfp_t);
- extern void __delete_from_swap_cache(struct page *);
- extern void delete_from_swap_cache(struct page *);
- extern int move_to_swap_cache(struct page *, swp_entry_t);
- extern int move_from_swap_cache(struct page *, unsigned long,
- struct address_space *);
- extern void free_page_and_swap_cache(struct page *);
- extern void free_pages_and_swap_cache(struct page **, int);
- extern struct page * lookup_swap_cache(swp_entry_t);
- extern struct page * read_swap_cache_async(swp_entry_t, struct vm_area_struct *vma,
- unsigned long addr);
- /* linux/mm/swapfile.c */
- extern long total_swap_pages;
- extern unsigned int nr_swapfiles;
- extern void si_swapinfo(struct sysinfo *);
- extern swp_entry_t get_swap_page(void);
- extern swp_entry_t get_swap_page_of_type(int);
- extern int swap_duplicate(swp_entry_t);
- extern int valid_swaphandles(swp_entry_t, unsigned long *);
- extern void swap_free(swp_entry_t);
- extern void free_swap_and_cache(swp_entry_t);
- extern int swap_type_of(dev_t, sector_t, struct block_device **);
- extern unsigned int count_swap_pages(int, int);
- extern sector_t map_swap_page(struct swap_info_struct *, pgoff_t);
- extern sector_t swapdev_block(int, pgoff_t);
- extern struct swap_info_struct *get_swap_info_struct(unsigned);
- extern int can_share_swap_page(struct page *);
- extern int remove_exclusive_swap_page(struct page *);
- struct backing_dev_info;
- extern spinlock_t swap_lock;
- /* linux/mm/thrash.c */
- extern struct mm_struct * swap_token_mm;
- extern void grab_swap_token(void);
- extern void __put_swap_token(struct mm_struct *);
- static inline int has_swap_token(struct mm_struct *mm)
- {
- return (mm == swap_token_mm);
- }
- static inline void put_swap_token(struct mm_struct *mm)
- {
- if (has_swap_token(mm))
- __put_swap_token(mm);
- }
- static inline void disable_swap_token(void)
- {
- put_swap_token(swap_token_mm);
- }
- #else /* CONFIG_SWAP */
- #define total_swap_pages 0
- #define total_swapcache_pages 0UL
- #define si_swapinfo(val) \
- do { (val)->freeswap = (val)->totalswap = 0; } while (0)
- /* only sparc can not include linux/pagemap.h in this file
- * so leave page_cache_release and release_pages undeclared... */
- #define free_page_and_swap_cache(page) \
- page_cache_release(page)
- #define free_pages_and_swap_cache(pages, nr) \
- release_pages((pages), (nr), 0);
- static inline void show_swap_cache_info(void)
- {
- }
- static inline void free_swap_and_cache(swp_entry_t swp)
- {
- }
- static inline int swap_duplicate(swp_entry_t swp)
- {
- return 0;
- }
- static inline void swap_free(swp_entry_t swp)
- {
- }
- static inline struct page *read_swap_cache_async(swp_entry_t swp,
- struct vm_area_struct *vma, unsigned long addr)
- {
- return NULL;
- }
- static inline struct page *lookup_swap_cache(swp_entry_t swp)
- {
- return NULL;
- }
- static inline int valid_swaphandles(swp_entry_t entry, unsigned long *offset)
- {
- return 0;
- }
- #define can_share_swap_page(p) (page_mapcount(p) == 1)
- static inline int move_to_swap_cache(struct page *page, swp_entry_t entry)
- {
- return 1;
- }
- static inline int move_from_swap_cache(struct page *page, unsigned long index,
- struct address_space *mapping)
- {
- return 1;
- }
- static inline void __delete_from_swap_cache(struct page *page)
- {
- }
- static inline void delete_from_swap_cache(struct page *page)
- {
- }
- #define swap_token_default_timeout 0
- static inline int remove_exclusive_swap_page(struct page *p)
- {
- return 0;
- }
- static inline swp_entry_t get_swap_page(void)
- {
- swp_entry_t entry;
- entry.val = 0;
- return entry;
- }
- /* linux/mm/thrash.c */
- #define put_swap_token(x) do { } while(0)
- #define grab_swap_token() do { } while(0)
- #define has_swap_token(x) 0
- #define disable_swap_token() do { } while(0)
- #endif /* CONFIG_SWAP */
- #endif /* __KERNEL__*/
- #endif /* _LINUX_SWAP_H */
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