| /* SPDX-License-Identifier: GPL-2.0 */ |
| #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/fs.h> |
| #include <linux/atomic.h> |
| #include <linux/page-flags.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 /* enable discard for swap */ |
| #define SWAP_FLAG_DISCARD_ONCE 0x20000 /* discard swap area at swapon-time */ |
| #define SWAP_FLAG_DISCARD_PAGES 0x40000 /* discard page-clusters after use */ |
| |
| #define SWAP_FLAGS_VALID (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \ |
| SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | \ |
| SWAP_FLAG_DISCARD_PAGES) |
| #define SWAP_BATCH 64 |
| |
| 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. |
| */ |
| |
| /* |
| * Unaddressable device memory support. See include/linux/hmm.h and |
| * Documentation/vm/hmm.rst. Short description is we need struct pages for |
| * device memory that is unaddressable (inaccessible) by CPU, so that we can |
| * migrate part of a process memory to device memory. |
| * |
| * When a page is migrated from CPU to device, we set the CPU page table entry |
| * to a special SWP_DEVICE_* entry. |
| */ |
| #ifdef CONFIG_DEVICE_PRIVATE |
| #define SWP_DEVICE_NUM 2 |
| #define SWP_DEVICE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM) |
| #define SWP_DEVICE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+1) |
| #else |
| #define SWP_DEVICE_NUM 0 |
| #endif |
| |
| /* |
| * 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_DEVICE_NUM - \ |
| 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; |
| }; |
| |
| /* |
| * 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), /* 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 */ |
| SWP_ACTIVATED = (1 << 7), /* set after swap_activate success */ |
| SWP_FS = (1 << 8), /* swap file goes through fs */ |
| SWP_AREA_DISCARD = (1 << 9), /* single-time swap area discards */ |
| SWP_PAGE_DISCARD = (1 << 10), /* freed swap page-cluster discards */ |
| SWP_STABLE_WRITES = (1 << 11), /* no overwrite PG_writeback pages */ |
| SWP_SYNCHRONOUS_IO = (1 << 12), /* synchronous IO is efficient */ |
| /* add others here before... */ |
| SWP_SCANNING = (1 << 13), /* refcount in scan_swap_map */ |
| }; |
| |
| #define SWAP_CLUSTER_MAX 32UL |
| #define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX |
| |
| #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 */ |
| |
| /* |
| * We use this to track usage of a cluster. A cluster is a block of swap disk |
| * space with SWAPFILE_CLUSTER pages long and naturally aligns in disk. All |
| * free clusters are organized into a list. We fetch an entry from the list to |
| * get a free cluster. |
| * |
| * The data field stores next cluster if the cluster is free or cluster usage |
| * counter otherwise. The flags field determines if a cluster is free. This is |
| * protected by swap_info_struct.lock. |
| */ |
| struct swap_cluster_info { |
| spinlock_t lock; /* |
| * Protect swap_cluster_info fields |
| * and swap_info_struct->swap_map |
| * elements correspond to the swap |
| * cluster |
| */ |
| unsigned int data:24; |
| unsigned int flags:8; |
| }; |
| #define CLUSTER_FLAG_FREE 1 /* This cluster is free */ |
| #define CLUSTER_FLAG_NEXT_NULL 2 /* This cluster has no next cluster */ |
| #define CLUSTER_FLAG_HUGE 4 /* This cluster is backing a transparent huge page */ |
| |
| /* |
| * We assign a cluster to each CPU, so each CPU can allocate swap entry from |
| * its own cluster and swapout sequentially. The purpose is to optimize swapout |
| * throughput. |
| */ |
| struct percpu_cluster { |
| struct swap_cluster_info index; /* Current cluster index */ |
| unsigned int next; /* Likely next allocation offset */ |
| }; |
| |
| struct swap_cluster_list { |
| struct swap_cluster_info head; |
| struct swap_cluster_info tail; |
| }; |
| |
| /* |
| * 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 */ |
| struct plist_node list; /* entry in swap_active_head */ |
| struct plist_node avail_lists[MAX_NUMNODES];/* entry in swap_avail_heads */ |
| signed char type; /* strange name for an index */ |
| unsigned int max; /* extent of the swap_map */ |
| unsigned char *swap_map; /* vmalloc'ed array of usage counts */ |
| struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */ |
| struct swap_cluster_list free_clusters; /* free clusters list */ |
| 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 */ |
| struct percpu_cluster __percpu *percpu_cluster; /* per cpu's swap location */ |
| 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 |
| spinlock_t lock; /* |
| * protect map scan related fields like |
| * swap_map, lowest_bit, highest_bit, |
| * inuse_pages, cluster_next, |
| * cluster_nr, lowest_alloc, |
| * highest_alloc, free/discard cluster |
| * list. other fields are only changed |
| * at swapon/swapoff, so are protected |
| * by swap_lock. changing flags need |
| * hold this lock and swap_lock. If |
| * both locks need hold, hold swap_lock |
| * first. |
| */ |
| spinlock_t cont_lock; /* |
| * protect swap count continuation page |
| * list. |
| */ |
| struct work_struct discard_work; /* discard worker */ |
| struct swap_cluster_list discard_clusters; /* discard clusters list */ |
| }; |
| |
| #ifdef CONFIG_64BIT |
| #define SWAP_RA_ORDER_CEILING 5 |
| #else |
| /* Avoid stack overflow, because we need to save part of page table */ |
| #define SWAP_RA_ORDER_CEILING 3 |
| #define SWAP_RA_PTE_CACHE_SIZE (1 << SWAP_RA_ORDER_CEILING) |
| #endif |
| |
| struct vma_swap_readahead { |
| unsigned short win; |
| unsigned short offset; |
| unsigned short nr_pte; |
| #ifdef CONFIG_64BIT |
| pte_t *ptes; |
| #else |
| pte_t ptes[SWAP_RA_PTE_CACHE_SIZE]; |
| #endif |
| }; |
| |
| /* linux/mm/workingset.c */ |
| void *workingset_eviction(struct address_space *mapping, struct page *page); |
| void workingset_refault(struct page *page, void *shadow); |
| void workingset_activation(struct page *page); |
| |
| /* Only track the nodes of mappings with shadow entries */ |
| void workingset_update_node(struct xa_node *node); |
| #define mapping_set_update(xas, mapping) do { \ |
| if (!dax_mapping(mapping) && !shmem_mapping(mapping)) \ |
| xas_set_update(xas, workingset_update_node); \ |
| } while (0) |
| |
| /* linux/mm/page_alloc.c */ |
| extern unsigned long totalram_pages; |
| extern unsigned long totalreserve_pages; |
| extern unsigned long nr_free_buffer_pages(void); |
| extern unsigned long nr_free_pagecache_pages(void); |
| |
| /* Definition of global_zone_page_state not available yet */ |
| #define nr_free_pages() global_zone_page_state(NR_FREE_PAGES) |
| |
| |
| /* linux/mm/swap.c */ |
| extern void lru_cache_add(struct page *); |
| extern void lru_cache_add_anon(struct page *page); |
| extern void lru_cache_add_file(struct page *page); |
| extern void lru_add_page_tail(struct page *page, struct page *page_tail, |
| struct lruvec *lruvec, struct list_head *head); |
| 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 void lru_add_drain_all(void); |
| extern void rotate_reclaimable_page(struct page *page); |
| extern void deactivate_file_page(struct page *page); |
| extern void mark_page_lazyfree(struct page *page); |
| extern void swap_setup(void); |
| |
| extern void lru_cache_add_active_or_unevictable(struct page *page, |
| struct vm_area_struct *vma); |
| |
| /* linux/mm/vmscan.c */ |
| extern unsigned long zone_reclaimable_pages(struct zone *zone); |
| 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); |
| extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, |
| unsigned long nr_pages, |
| gfp_t gfp_mask, |
| bool may_swap); |
| extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem, |
| gfp_t gfp_mask, bool noswap, |
| pg_data_t *pgdat, |
| 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 unsigned long vm_total_pages; |
| |
| #ifdef CONFIG_NUMA |
| extern int node_reclaim_mode; |
| extern int sysctl_min_unmapped_ratio; |
| extern int sysctl_min_slab_ratio; |
| extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int); |
| #else |
| #define node_reclaim_mode 0 |
| static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask, |
| unsigned int order) |
| { |
| return 0; |
| } |
| #endif |
| |
| extern int page_evictable(struct page *page); |
| extern void check_move_unevictable_pages(struct page **, int nr_pages); |
| |
| extern int kswapd_run(int nid); |
| extern void kswapd_stop(int nid); |
| |
| #ifdef CONFIG_SWAP |
| |
| #include <linux/blk_types.h> /* for bio_end_io_t */ |
| |
| /* linux/mm/page_io.c */ |
| extern int swap_readpage(struct page *page, bool do_poll); |
| extern int swap_writepage(struct page *page, struct writeback_control *wbc); |
| extern void end_swap_bio_write(struct bio *bio); |
| extern int __swap_writepage(struct page *page, struct writeback_control *wbc, |
| bio_end_io_t end_write_func); |
| extern int swap_set_page_dirty(struct page *page); |
| |
| int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page, |
| unsigned long nr_pages, sector_t start_block); |
| int generic_swapfile_activate(struct swap_info_struct *, struct file *, |
| sector_t *); |
| |
| /* linux/mm/swap_state.c */ |
| /* One swap address space for each 64M swap space */ |
| #define SWAP_ADDRESS_SPACE_SHIFT 14 |
| #define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT) |
| extern struct address_space *swapper_spaces[]; |
| #define swap_address_space(entry) \ |
| (&swapper_spaces[swp_type(entry)][swp_offset(entry) \ |
| >> SWAP_ADDRESS_SPACE_SHIFT]) |
| extern unsigned long total_swapcache_pages(void); |
| extern void show_swap_cache_info(void); |
| extern int add_to_swap(struct page *page); |
| extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t); |
| extern int __add_to_swap_cache(struct page *page, swp_entry_t entry); |
| extern void __delete_from_swap_cache(struct page *, swp_entry_t entry); |
| 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 entry, |
| struct vm_area_struct *vma, |
| unsigned long addr); |
| extern struct page *read_swap_cache_async(swp_entry_t, gfp_t, |
| struct vm_area_struct *vma, unsigned long addr, |
| bool do_poll); |
| extern struct page *__read_swap_cache_async(swp_entry_t, gfp_t, |
| struct vm_area_struct *vma, unsigned long addr, |
| bool *new_page_allocated); |
| extern struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag, |
| struct vm_fault *vmf); |
| extern struct page *swapin_readahead(swp_entry_t entry, gfp_t flag, |
| struct vm_fault *vmf); |
| |
| /* linux/mm/swapfile.c */ |
| extern atomic_long_t nr_swap_pages; |
| extern long total_swap_pages; |
| extern atomic_t nr_rotate_swap; |
| extern bool has_usable_swap(void); |
| |
| /* Swap 50% full? Release swapcache more aggressively.. */ |
| static inline bool vm_swap_full(void) |
| { |
| return atomic_long_read(&nr_swap_pages) * 2 < total_swap_pages; |
| } |
| |
| static inline long get_nr_swap_pages(void) |
| { |
| return atomic_long_read(&nr_swap_pages); |
| } |
| |
| extern void si_swapinfo(struct sysinfo *); |
| extern swp_entry_t get_swap_page(struct page *page); |
| extern void put_swap_page(struct page *page, swp_entry_t entry); |
| extern swp_entry_t get_swap_page_of_type(int); |
| extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size); |
| 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_entries(swp_entry_t *entries, int n); |
| 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 page_swapcount(struct page *); |
| extern int __swap_count(struct swap_info_struct *si, swp_entry_t entry); |
| extern int __swp_swapcount(swp_entry_t entry); |
| extern int swp_swapcount(swp_entry_t entry); |
| extern struct swap_info_struct *page_swap_info(struct page *); |
| extern struct swap_info_struct *swp_swap_info(swp_entry_t entry); |
| extern bool reuse_swap_page(struct page *, int *); |
| extern int try_to_free_swap(struct page *); |
| struct backing_dev_info; |
| extern int init_swap_address_space(unsigned int type, unsigned long nr_pages); |
| extern void exit_swap_address_space(unsigned int type); |
| |
| #else /* CONFIG_SWAP */ |
| |
| static inline int swap_readpage(struct page *page, bool do_poll) |
| { |
| return 0; |
| } |
| |
| static inline struct swap_info_struct *swp_swap_info(swp_entry_t entry) |
| { |
| return NULL; |
| } |
| |
| #define swap_address_space(entry) (NULL) |
| #define get_nr_swap_pages() 0L |
| #define total_swap_pages 0L |
| #define total_swapcache_pages() 0UL |
| #define vm_swap_full() 0 |
| |
| #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 put_page and release_pages undeclared... */ |
| #define free_page_and_swap_cache(page) \ |
| put_page(page) |
| #define free_pages_and_swap_cache(pages, nr) \ |
| release_pages((pages), (nr)); |
| |
| static inline void show_swap_cache_info(void) |
| { |
| } |
| |
| #define free_swap_and_cache(e) ({(is_migration_entry(e) || is_device_private_entry(e));}) |
| #define swapcache_prepare(e) ({(is_migration_entry(e) || is_device_private_entry(e));}) |
| |
| 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 put_swap_page(struct page *page, swp_entry_t swp) |
| { |
| } |
| |
| static inline struct page *swap_cluster_readahead(swp_entry_t entry, |
| gfp_t gfp_mask, struct vm_fault *vmf) |
| { |
| return NULL; |
| } |
| |
| static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, |
| struct vm_fault *vmf) |
| { |
| 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, |
| struct vm_area_struct *vma, |
| unsigned long addr) |
| { |
| 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, |
| swp_entry_t entry) |
| { |
| } |
| |
| static inline void delete_from_swap_cache(struct page *page) |
| { |
| } |
| |
| static inline int page_swapcount(struct page *page) |
| { |
| return 0; |
| } |
| |
| static inline int __swap_count(struct swap_info_struct *si, swp_entry_t entry) |
| { |
| return 0; |
| } |
| |
| static inline int __swp_swapcount(swp_entry_t entry) |
| { |
| return 0; |
| } |
| |
| static inline int swp_swapcount(swp_entry_t entry) |
| { |
| return 0; |
| } |
| |
| #define reuse_swap_page(page, total_map_swapcount) \ |
| (page_trans_huge_mapcount(page, total_map_swapcount) == 1) |
| |
| static inline int try_to_free_swap(struct page *page) |
| { |
| return 0; |
| } |
| |
| static inline swp_entry_t get_swap_page(struct page *page) |
| { |
| swp_entry_t entry; |
| entry.val = 0; |
| return entry; |
| } |
| |
| #endif /* CONFIG_SWAP */ |
| |
| #ifdef CONFIG_THP_SWAP |
| extern int split_swap_cluster(swp_entry_t entry); |
| #else |
| static inline int split_swap_cluster(swp_entry_t entry) |
| { |
| return 0; |
| } |
| #endif |
| |
| #ifdef CONFIG_MEMCG |
| static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg) |
| { |
| /* Cgroup2 doesn't have per-cgroup swappiness */ |
| if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) |
| return vm_swappiness; |
| |
| /* root ? */ |
| if (mem_cgroup_disabled() || !memcg->css.parent) |
| return vm_swappiness; |
| |
| return memcg->swappiness; |
| } |
| #else |
| static inline int mem_cgroup_swappiness(struct mem_cgroup *mem) |
| { |
| return vm_swappiness; |
| } |
| #endif |
| |
| #if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP) |
| extern void mem_cgroup_throttle_swaprate(struct mem_cgroup *memcg, int node, |
| gfp_t gfp_mask); |
| #else |
| static inline void mem_cgroup_throttle_swaprate(struct mem_cgroup *memcg, |
| int node, gfp_t gfp_mask) |
| { |
| } |
| #endif |
| |
| #ifdef CONFIG_MEMCG_SWAP |
| extern void mem_cgroup_swapout(struct page *page, swp_entry_t entry); |
| extern int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry); |
| extern void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages); |
| extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg); |
| extern bool mem_cgroup_swap_full(struct page *page); |
| #else |
| static inline void mem_cgroup_swapout(struct page *page, swp_entry_t entry) |
| { |
| } |
| |
| static inline int mem_cgroup_try_charge_swap(struct page *page, |
| swp_entry_t entry) |
| { |
| return 0; |
| } |
| |
| static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, |
| unsigned int nr_pages) |
| { |
| } |
| |
| static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) |
| { |
| return get_nr_swap_pages(); |
| } |
| |
| static inline bool mem_cgroup_swap_full(struct page *page) |
| { |
| return vm_swap_full(); |
| } |
| #endif |
| |
| #endif /* __KERNEL__*/ |
| #endif /* _LINUX_SWAP_H */ |