/include/linux/swap.h
https://github.com/airy09/android_kernel_sony_apq8064 · C Header · 516 lines · 368 code · 71 blank · 77 comment · 4 complexity · 736d44d741b29e966213c1ac63dd2214 MD5 · raw file
- #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/memcontrol.h>
- #include <linux/sched.h>
- #include <linux/node.h>
- #include <linux/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
- #define SWAP_FLAG_DISCARD 0x10000 /* discard swap cluster after use */
- #define SWAP_FLAGS_VALID (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \
- SWAP_FLAG_DISCARD)
- 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
- /*
- * Use some of the swap files numbers for other purposes. This
- * is a convenient way to hook into the VM to trigger special
- * actions on faults.
- */
- /*
- * NUMA node memory migration support
- */
- #ifdef CONFIG_MIGRATION
- #define SWP_MIGRATION_NUM 2
- #define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM)
- #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1)
- #else
- #define SWP_MIGRATION_NUM 0
- #endif
- /*
- * Handling of hardware poisoned pages with memory corruption.
- */
- #ifdef CONFIG_MEMORY_FAILURE
- #define SWP_HWPOISON_NUM 1
- #define SWP_HWPOISON MAX_SWAPFILES
- #else
- #define SWP_HWPOISON_NUM 0
- #endif
- #define MAX_SWAPFILES \
- ((1 << MAX_SWAPFILES_SHIFT) - SWP_MIGRATION_NUM - SWP_HWPOISON_NUM)
- /*
- * 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_DISCARDABLE = (1 << 2), /* swapon+blkdev support discard */
- SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */
- SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */
- SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */
- SWP_BLKDEV = (1 << 6), /* its a block device */
- /* add others here before... */
- SWP_SCANNING = (1 << 8), /* refcount in scan_swap_map */
- };
- #define SWAP_CLUSTER_MAX 32
- #define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX
- /*
- * Ratio between the present memory in the zone and the "gap" that
- * we're allowing kswapd to shrink in addition to the per-zone high
- * wmark, even for zones that already have the high wmark satisfied,
- * in order to provide better per-zone lru behavior. We are ok to
- * spend not more than 1% of the memory for this zone balancing "gap".
- */
- #define KSWAPD_ZONE_BALANCE_GAP_RATIO 100
- #define SWAP_MAP_MAX 0x3e /* Max duplication count, in first swap_map */
- #define SWAP_MAP_BAD 0x3f /* Note pageblock is bad, in first swap_map */
- #define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */
- #define SWAP_CONT_MAX 0x7f /* Max count, in each swap_map continuation */
- #define COUNT_CONTINUED 0x80 /* See swap_map continuation for full count */
- #define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs, in first swap_map */
- /*
- * The in-memory structure used to track swap areas.
- */
- struct swap_info_struct {
- unsigned long flags; /* SWP_USED etc: see above */
- signed short prio; /* swap priority of this type */
- signed char type; /* strange name for an index */
- signed char next; /* next type on the swap list */
- unsigned int max; /* extent of the swap_map */
- unsigned char *swap_map; /* vmalloc'ed array of usage counts */
- unsigned int lowest_bit; /* index of first free in swap_map */
- unsigned int highest_bit; /* index of last free in swap_map */
- unsigned int pages; /* total of usable pages of swap */
- unsigned int inuse_pages; /* number of those currently in use */
- unsigned int cluster_next; /* likely index for next allocation */
- unsigned int cluster_nr; /* countdown to next cluster search */
- unsigned int lowest_alloc; /* while preparing discard cluster */
- unsigned int highest_alloc; /* while preparing discard cluster */
- struct swap_extent *curr_swap_extent;
- struct swap_extent first_swap_extent;
- struct block_device *bdev; /* swap device or bdev of swap file */
- struct file *swap_file; /* seldom referenced */
- unsigned int old_block_size; /* seldom referenced */
- #ifdef CONFIG_FRONTSWAP
- unsigned long *frontswap_map; /* frontswap in-use, one bit per page */
- atomic_t frontswap_pages; /* frontswap pages in-use counter */
- #endif
- };
- 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/page_alloc.c */
- extern unsigned long totalram_pages;
- extern unsigned long totalreserve_pages;
- extern unsigned long dirty_balance_reserve;
- 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 __lru_cache_add(struct page *, enum lru_list lru);
- extern void lru_cache_add_lru(struct page *, enum lru_list lru);
- extern void lru_add_page_tail(struct zone* zone,
- struct page *page, struct page *page_tail);
- extern void activate_page(struct page *);
- extern void mark_page_accessed(struct page *);
- extern void lru_add_drain(void);
- extern void lru_add_drain_cpu(int cpu);
- extern int lru_add_drain_all(void);
- extern void rotate_reclaimable_page(struct page *page);
- extern void deactivate_page(struct page *page);
- extern void swap_setup(void);
- extern void add_page_to_unevictable_list(struct page *page);
- /**
- * lru_cache_add: add a page to the page lists
- * @page: the page to add
- */
- static inline void lru_cache_add_anon(struct page *page)
- {
- __lru_cache_add(page, LRU_INACTIVE_ANON);
- }
- static inline void lru_cache_add_file(struct page *page)
- {
- __lru_cache_add(page, LRU_INACTIVE_FILE);
- }
- /* linux/mm/vmscan.c */
- extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
- gfp_t gfp_mask, nodemask_t *mask);
- extern int __isolate_lru_page(struct page *page, isolate_mode_t mode, int file);
- extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem,
- gfp_t gfp_mask, bool noswap);
- extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
- gfp_t gfp_mask, bool noswap,
- struct zone *zone,
- unsigned long *nr_scanned);
- 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 page_evictable(struct page *page, struct vm_area_struct *vma);
- extern void check_move_unevictable_pages(struct page **, int nr_pages);
- extern unsigned long scan_unevictable_pages;
- extern int scan_unevictable_handler(struct ctl_table *, int,
- void __user *, size_t *, loff_t *);
- #ifdef CONFIG_NUMA
- extern int scan_unevictable_register_node(struct node *node);
- extern void scan_unevictable_unregister_node(struct node *node);
- #else
- static inline int scan_unevictable_register_node(struct node *node)
- {
- return 0;
- }
- static inline void scan_unevictable_unregister_node(struct node *node)
- {
- }
- #endif
- extern int kswapd_run(int nid);
- extern void kswapd_stop(int nid);
- #ifdef CONFIG_CGROUP_MEM_RES_CTLR
- extern int mem_cgroup_swappiness(struct mem_cgroup *mem);
- #else
- static inline int mem_cgroup_swappiness(struct mem_cgroup *mem)
- {
- return vm_swappiness;
- }
- #endif
- #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
- extern void mem_cgroup_uncharge_swap(swp_entry_t ent);
- #else
- static inline void mem_cgroup_uncharge_swap(swp_entry_t ent)
- {
- }
- #endif
- #ifdef CONFIG_SWAP
- /* linux/mm/page_io.c */
- extern int swap_readpage(struct page *);
- extern int swap_writepage(struct page *page, struct writeback_control *wbc);
- extern void end_swap_bio_read(struct bio *bio, 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 *);
- extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t);
- extern void __delete_from_swap_cache(struct page *);
- extern void delete_from_swap_cache(struct page *);
- 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, gfp_t,
- struct vm_area_struct *vma, unsigned long addr);
- extern struct page *swapin_readahead(swp_entry_t, gfp_t,
- struct vm_area_struct *vma, unsigned long addr);
- /* linux/mm/swapfile.c */
- extern long nr_swap_pages;
- extern long total_swap_pages;
- 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 add_swap_count_continuation(swp_entry_t, gfp_t);
- extern void swap_shmem_alloc(swp_entry_t);
- extern int swap_duplicate(swp_entry_t);
- extern int swapcache_prepare(swp_entry_t);
- extern void swap_free(swp_entry_t);
- extern void swapcache_free(swp_entry_t, struct page *page);
- extern int 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 page *, struct block_device **);
- extern sector_t swapdev_block(int, pgoff_t);
- extern int reuse_swap_page(struct page *);
- extern int try_to_free_swap(struct page *);
- struct backing_dev_info;
- /* linux/mm/thrash.c */
- extern struct mm_struct *swap_token_mm;
- extern void grab_swap_token(struct mm_struct *);
- extern void __put_swap_token(struct mm_struct *);
- extern void disable_swap_token(struct mem_cgroup *memcg);
- 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);
- }
- #ifdef CONFIG_CGROUP_MEM_RES_CTLR
- extern void
- mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout);
- extern int mem_cgroup_count_swap_user(swp_entry_t ent, struct page **pagep);
- #else
- static inline void
- mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
- {
- }
- #endif
- #else /* CONFIG_SWAP */
- #define nr_swap_pages 0L
- #define total_swap_pages 0L
- #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)
- {
- }
- #define free_swap_and_cache(swp) is_migration_entry(swp)
- #define swapcache_prepare(swp) is_migration_entry(swp)
- static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask)
- {
- return 0;
- }
- static inline void swap_shmem_alloc(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 void swapcache_free(swp_entry_t swp, struct page *page)
- {
- }
- static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
- struct vm_area_struct *vma, unsigned long addr)
- {
- return NULL;
- }
- static inline int swap_writepage(struct page *p, struct writeback_control *wbc)
- {
- return 0;
- }
- static inline struct page *lookup_swap_cache(swp_entry_t swp)
- {
- return NULL;
- }
- static inline int add_to_swap(struct page *page)
- {
- return 0;
- }
- static inline int add_to_swap_cache(struct page *page, swp_entry_t entry,
- gfp_t gfp_mask)
- {
- return -1;
- }
- static inline void __delete_from_swap_cache(struct page *page)
- {
- }
- static inline void delete_from_swap_cache(struct page *page)
- {
- }
- #define reuse_swap_page(page) (page_mapcount(page) == 1)
- static inline int try_to_free_swap(struct page *page)
- {
- return 0;
- }
- static inline swp_entry_t get_swap_page(void)
- {
- swp_entry_t entry;
- entry.val = 0;
- return entry;
- }
- /* linux/mm/thrash.c */
- static inline void put_swap_token(struct mm_struct *mm)
- {
- }
- static inline void grab_swap_token(struct mm_struct *mm)
- {
- }
- static inline int has_swap_token(struct mm_struct *mm)
- {
- return 0;
- }
- static inline void disable_swap_token(struct mem_cgroup *memcg)
- {
- }
- static inline void
- mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent)
- {
- }
- #ifdef CONFIG_CGROUP_MEM_RES_CTLR
- static inline int
- mem_cgroup_count_swap_user(swp_entry_t ent, struct page **pagep)
- {
- return 0;
- }
- #endif
- #endif /* CONFIG_SWAP */
- #endif /* __KERNEL__*/
- #endif /* _LINUX_SWAP_H */