]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | #ifndef _LINUX_SWAP_H |
2 | #define _LINUX_SWAP_H | |
3 | ||
1da177e4 LT |
4 | #include <linux/spinlock.h> |
5 | #include <linux/linkage.h> | |
6 | #include <linux/mmzone.h> | |
7 | #include <linux/list.h> | |
66e1707b | 8 | #include <linux/memcontrol.h> |
1da177e4 | 9 | #include <linux/sched.h> |
af936a16 | 10 | #include <linux/node.h> |
33806f06 | 11 | #include <linux/fs.h> |
60063497 | 12 | #include <linux/atomic.h> |
c53954a0 | 13 | #include <linux/page-flags.h> |
1da177e4 LT |
14 | #include <asm/page.h> |
15 | ||
8bc719d3 MS |
16 | struct notifier_block; |
17 | ||
ab954160 AM |
18 | struct bio; |
19 | ||
1da177e4 LT |
20 | #define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */ |
21 | #define SWAP_FLAG_PRIO_MASK 0x7fff | |
22 | #define SWAP_FLAG_PRIO_SHIFT 0 | |
dcf6b7dd RA |
23 | #define SWAP_FLAG_DISCARD 0x10000 /* enable discard for swap */ |
24 | #define SWAP_FLAG_DISCARD_ONCE 0x20000 /* discard swap area at swapon-time */ | |
25 | #define SWAP_FLAG_DISCARD_PAGES 0x40000 /* discard page-clusters after use */ | |
1da177e4 | 26 | |
d15cab97 | 27 | #define SWAP_FLAGS_VALID (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \ |
dcf6b7dd RA |
28 | SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | \ |
29 | SWAP_FLAG_DISCARD_PAGES) | |
36005bae | 30 | #define SWAP_BATCH 64 |
d15cab97 | 31 | |
1da177e4 LT |
32 | static inline int current_is_kswapd(void) |
33 | { | |
34 | return current->flags & PF_KSWAPD; | |
35 | } | |
36 | ||
37 | /* | |
38 | * MAX_SWAPFILES defines the maximum number of swaptypes: things which can | |
39 | * be swapped to. The swap type and the offset into that swap type are | |
40 | * encoded into pte's and into pgoff_t's in the swapcache. Using five bits | |
41 | * for the type means that the maximum number of swapcache pages is 27 bits | |
42 | * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs | |
43 | * the type/offset into the pte as 5/27 as well. | |
44 | */ | |
45 | #define MAX_SWAPFILES_SHIFT 5 | |
a7420aa5 AK |
46 | |
47 | /* | |
48 | * Use some of the swap files numbers for other purposes. This | |
49 | * is a convenient way to hook into the VM to trigger special | |
50 | * actions on faults. | |
51 | */ | |
52 | ||
53 | /* | |
54 | * NUMA node memory migration support | |
55 | */ | |
56 | #ifdef CONFIG_MIGRATION | |
57 | #define SWP_MIGRATION_NUM 2 | |
58 | #define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM) | |
59 | #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1) | |
0697212a | 60 | #else |
a7420aa5 | 61 | #define SWP_MIGRATION_NUM 0 |
0697212a | 62 | #endif |
1da177e4 | 63 | |
a7420aa5 AK |
64 | /* |
65 | * Handling of hardware poisoned pages with memory corruption. | |
66 | */ | |
67 | #ifdef CONFIG_MEMORY_FAILURE | |
68 | #define SWP_HWPOISON_NUM 1 | |
69 | #define SWP_HWPOISON MAX_SWAPFILES | |
70 | #else | |
71 | #define SWP_HWPOISON_NUM 0 | |
72 | #endif | |
73 | ||
74 | #define MAX_SWAPFILES \ | |
75 | ((1 << MAX_SWAPFILES_SHIFT) - SWP_MIGRATION_NUM - SWP_HWPOISON_NUM) | |
76 | ||
1da177e4 LT |
77 | /* |
78 | * Magic header for a swap area. The first part of the union is | |
79 | * what the swap magic looks like for the old (limited to 128MB) | |
80 | * swap area format, the second part of the union adds - in the | |
81 | * old reserved area - some extra information. Note that the first | |
82 | * kilobyte is reserved for boot loader or disk label stuff... | |
83 | * | |
84 | * Having the magic at the end of the PAGE_SIZE makes detecting swap | |
85 | * areas somewhat tricky on machines that support multiple page sizes. | |
86 | * For 2.5 we'll probably want to move the magic to just beyond the | |
87 | * bootbits... | |
88 | */ | |
89 | union swap_header { | |
90 | struct { | |
91 | char reserved[PAGE_SIZE - 10]; | |
92 | char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ | |
93 | } magic; | |
94 | struct { | |
e8f03d02 AD |
95 | char bootbits[1024]; /* Space for disklabel etc. */ |
96 | __u32 version; | |
97 | __u32 last_page; | |
98 | __u32 nr_badpages; | |
99 | unsigned char sws_uuid[16]; | |
100 | unsigned char sws_volume[16]; | |
101 | __u32 padding[117]; | |
102 | __u32 badpages[1]; | |
1da177e4 LT |
103 | } info; |
104 | }; | |
105 | ||
1da177e4 LT |
106 | /* |
107 | * current->reclaim_state points to one of these when a task is running | |
108 | * memory reclaim | |
109 | */ | |
110 | struct reclaim_state { | |
111 | unsigned long reclaimed_slab; | |
112 | }; | |
113 | ||
114 | #ifdef __KERNEL__ | |
115 | ||
116 | struct address_space; | |
117 | struct sysinfo; | |
118 | struct writeback_control; | |
119 | struct zone; | |
120 | ||
121 | /* | |
122 | * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of | |
123 | * disk blocks. A list of swap extents maps the entire swapfile. (Where the | |
124 | * term `swapfile' refers to either a blockdevice or an IS_REG file. Apart | |
125 | * from setup, they're handled identically. | |
126 | * | |
127 | * We always assume that blocks are of size PAGE_SIZE. | |
128 | */ | |
129 | struct swap_extent { | |
130 | struct list_head list; | |
131 | pgoff_t start_page; | |
132 | pgoff_t nr_pages; | |
133 | sector_t start_block; | |
134 | }; | |
135 | ||
136 | /* | |
137 | * Max bad pages in the new format.. | |
138 | */ | |
139 | #define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x) | |
140 | #define MAX_SWAP_BADPAGES \ | |
141 | ((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int)) | |
142 | ||
143 | enum { | |
144 | SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ | |
145 | SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ | |
dcf6b7dd | 146 | SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */ |
7992fde7 | 147 | SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */ |
20137a49 | 148 | SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */ |
570a335b | 149 | SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */ |
b2725643 | 150 | SWP_BLKDEV = (1 << 6), /* its a block device */ |
62c230bc | 151 | SWP_FILE = (1 << 7), /* set after swap_activate success */ |
dcf6b7dd RA |
152 | SWP_AREA_DISCARD = (1 << 8), /* single-time swap area discards */ |
153 | SWP_PAGE_DISCARD = (1 << 9), /* freed swap page-cluster discards */ | |
f0571429 | 154 | SWP_STABLE_WRITES = (1 << 10), /* no overwrite PG_writeback pages */ |
52b7efdb | 155 | /* add others here before... */ |
f0571429 | 156 | SWP_SCANNING = (1 << 11), /* refcount in scan_swap_map */ |
1da177e4 LT |
157 | }; |
158 | ||
d778df51 | 159 | #define SWAP_CLUSTER_MAX 32UL |
748446bb | 160 | #define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX |
1da177e4 | 161 | |
570a335b HD |
162 | #define SWAP_MAP_MAX 0x3e /* Max duplication count, in first swap_map */ |
163 | #define SWAP_MAP_BAD 0x3f /* Note pageblock is bad, in first swap_map */ | |
164 | #define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */ | |
165 | #define SWAP_CONT_MAX 0x7f /* Max count, in each swap_map continuation */ | |
166 | #define COUNT_CONTINUED 0x80 /* See swap_map continuation for full count */ | |
aaa46865 | 167 | #define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs, in first swap_map */ |
253d553b | 168 | |
2a8f9449 SL |
169 | /* |
170 | * We use this to track usage of a cluster. A cluster is a block of swap disk | |
171 | * space with SWAPFILE_CLUSTER pages long and naturally aligns in disk. All | |
172 | * free clusters are organized into a list. We fetch an entry from the list to | |
173 | * get a free cluster. | |
174 | * | |
175 | * The data field stores next cluster if the cluster is free or cluster usage | |
176 | * counter otherwise. The flags field determines if a cluster is free. This is | |
177 | * protected by swap_info_struct.lock. | |
178 | */ | |
179 | struct swap_cluster_info { | |
235b6217 HY |
180 | spinlock_t lock; /* |
181 | * Protect swap_cluster_info fields | |
182 | * and swap_info_struct->swap_map | |
183 | * elements correspond to the swap | |
184 | * cluster | |
185 | */ | |
2a8f9449 SL |
186 | unsigned int data:24; |
187 | unsigned int flags:8; | |
188 | }; | |
189 | #define CLUSTER_FLAG_FREE 1 /* This cluster is free */ | |
190 | #define CLUSTER_FLAG_NEXT_NULL 2 /* This cluster has no next cluster */ | |
191 | ||
ebc2a1a6 SL |
192 | /* |
193 | * We assign a cluster to each CPU, so each CPU can allocate swap entry from | |
194 | * its own cluster and swapout sequentially. The purpose is to optimize swapout | |
195 | * throughput. | |
196 | */ | |
197 | struct percpu_cluster { | |
198 | struct swap_cluster_info index; /* Current cluster index */ | |
199 | unsigned int next; /* Likely next allocation offset */ | |
200 | }; | |
201 | ||
6b534915 HY |
202 | struct swap_cluster_list { |
203 | struct swap_cluster_info head; | |
204 | struct swap_cluster_info tail; | |
205 | }; | |
206 | ||
1da177e4 LT |
207 | /* |
208 | * The in-memory structure used to track swap areas. | |
1da177e4 LT |
209 | */ |
210 | struct swap_info_struct { | |
efa90a98 HD |
211 | unsigned long flags; /* SWP_USED etc: see above */ |
212 | signed short prio; /* swap priority of this type */ | |
18ab4d4c DS |
213 | struct plist_node list; /* entry in swap_active_head */ |
214 | struct plist_node avail_list; /* entry in swap_avail_head */ | |
efa90a98 | 215 | signed char type; /* strange name for an index */ |
7509765a HD |
216 | unsigned int max; /* extent of the swap_map */ |
217 | unsigned char *swap_map; /* vmalloc'ed array of usage counts */ | |
2a8f9449 | 218 | struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */ |
6b534915 | 219 | struct swap_cluster_list free_clusters; /* free clusters list */ |
7509765a HD |
220 | unsigned int lowest_bit; /* index of first free in swap_map */ |
221 | unsigned int highest_bit; /* index of last free in swap_map */ | |
222 | unsigned int pages; /* total of usable pages of swap */ | |
223 | unsigned int inuse_pages; /* number of those currently in use */ | |
224 | unsigned int cluster_next; /* likely index for next allocation */ | |
225 | unsigned int cluster_nr; /* countdown to next cluster search */ | |
ebc2a1a6 | 226 | struct percpu_cluster __percpu *percpu_cluster; /* per cpu's swap location */ |
7509765a HD |
227 | struct swap_extent *curr_swap_extent; |
228 | struct swap_extent first_swap_extent; | |
229 | struct block_device *bdev; /* swap device or bdev of swap file */ | |
230 | struct file *swap_file; /* seldom referenced */ | |
231 | unsigned int old_block_size; /* seldom referenced */ | |
38b5faf4 DM |
232 | #ifdef CONFIG_FRONTSWAP |
233 | unsigned long *frontswap_map; /* frontswap in-use, one bit per page */ | |
234 | atomic_t frontswap_pages; /* frontswap pages in-use counter */ | |
235 | #endif | |
ec8acf20 SL |
236 | spinlock_t lock; /* |
237 | * protect map scan related fields like | |
238 | * swap_map, lowest_bit, highest_bit, | |
239 | * inuse_pages, cluster_next, | |
815c2c54 SL |
240 | * cluster_nr, lowest_alloc, |
241 | * highest_alloc, free/discard cluster | |
242 | * list. other fields are only changed | |
243 | * at swapon/swapoff, so are protected | |
244 | * by swap_lock. changing flags need | |
245 | * hold this lock and swap_lock. If | |
246 | * both locks need hold, hold swap_lock | |
247 | * first. | |
ec8acf20 | 248 | */ |
815c2c54 | 249 | struct work_struct discard_work; /* discard worker */ |
6b534915 | 250 | struct swap_cluster_list discard_clusters; /* discard clusters list */ |
1da177e4 LT |
251 | }; |
252 | ||
a528910e JW |
253 | /* linux/mm/workingset.c */ |
254 | void *workingset_eviction(struct address_space *mapping, struct page *page); | |
255 | bool workingset_refault(void *shadow); | |
256 | void workingset_activation(struct page *page); | |
14b46879 | 257 | void workingset_update_node(struct radix_tree_node *node, void *private); |
a528910e | 258 | |
1da177e4 LT |
259 | /* linux/mm/page_alloc.c */ |
260 | extern unsigned long totalram_pages; | |
cb45b0e9 | 261 | extern unsigned long totalreserve_pages; |
ebec3862 ZY |
262 | extern unsigned long nr_free_buffer_pages(void); |
263 | extern unsigned long nr_free_pagecache_pages(void); | |
1da177e4 | 264 | |
96177299 CL |
265 | /* Definition of global_page_state not available yet */ |
266 | #define nr_free_pages() global_page_state(NR_FREE_PAGES) | |
267 | ||
268 | ||
1da177e4 | 269 | /* linux/mm/swap.c */ |
c53954a0 | 270 | extern void lru_cache_add(struct page *); |
2329d375 JZ |
271 | extern void lru_cache_add_anon(struct page *page); |
272 | extern void lru_cache_add_file(struct page *page); | |
fa9add64 | 273 | extern void lru_add_page_tail(struct page *page, struct page *page_tail, |
5bc7b8ac | 274 | struct lruvec *lruvec, struct list_head *head); |
b3c97528 HH |
275 | extern void activate_page(struct page *); |
276 | extern void mark_page_accessed(struct page *); | |
1da177e4 | 277 | extern void lru_add_drain(void); |
f0cb3c76 | 278 | extern void lru_add_drain_cpu(int cpu); |
5fbc4616 | 279 | extern void lru_add_drain_all(void); |
ac6aadb2 | 280 | extern void rotate_reclaimable_page(struct page *page); |
cc5993bd | 281 | extern void deactivate_file_page(struct page *page); |
f7ad2a6c | 282 | extern void mark_page_lazyfree(struct page *page); |
1da177e4 LT |
283 | extern void swap_setup(void); |
284 | ||
894bc310 LS |
285 | extern void add_page_to_unevictable_list(struct page *page); |
286 | ||
00501b53 JW |
287 | extern void lru_cache_add_active_or_unevictable(struct page *page, |
288 | struct vm_area_struct *vma); | |
289 | ||
1da177e4 | 290 | /* linux/mm/vmscan.c */ |
5a1c84b4 | 291 | extern unsigned long zone_reclaimable_pages(struct zone *zone); |
599d0c95 | 292 | extern unsigned long pgdat_reclaimable_pages(struct pglist_data *pgdat); |
dac1d27b | 293 | extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, |
327c0e96 | 294 | gfp_t gfp_mask, nodemask_t *mask); |
f3fd4a61 | 295 | extern int __isolate_lru_page(struct page *page, isolate_mode_t mode); |
b70a2a21 JW |
296 | extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, |
297 | unsigned long nr_pages, | |
298 | gfp_t gfp_mask, | |
299 | bool may_swap); | |
a9dd0a83 | 300 | extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem, |
185efc0f | 301 | gfp_t gfp_mask, bool noswap, |
ef8f2327 | 302 | pg_data_t *pgdat, |
185efc0f | 303 | unsigned long *nr_scanned); |
69e05944 | 304 | extern unsigned long shrink_all_memory(unsigned long nr_pages); |
1da177e4 | 305 | extern int vm_swappiness; |
b20a3503 | 306 | extern int remove_mapping(struct address_space *mapping, struct page *page); |
b21e0b90 | 307 | extern unsigned long vm_total_pages; |
b20a3503 | 308 | |
9eeff239 | 309 | #ifdef CONFIG_NUMA |
a5f5f91d | 310 | extern int node_reclaim_mode; |
9614634f | 311 | extern int sysctl_min_unmapped_ratio; |
0ff38490 | 312 | extern int sysctl_min_slab_ratio; |
a5f5f91d | 313 | extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int); |
9eeff239 | 314 | #else |
a5f5f91d MG |
315 | #define node_reclaim_mode 0 |
316 | static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask, | |
317 | unsigned int order) | |
9eeff239 CL |
318 | { |
319 | return 0; | |
320 | } | |
321 | #endif | |
322 | ||
39b5f29a | 323 | extern int page_evictable(struct page *page); |
24513264 | 324 | extern void check_move_unevictable_pages(struct page **, int nr_pages); |
af936a16 | 325 | |
3218ae14 | 326 | extern int kswapd_run(int nid); |
8fe23e05 | 327 | extern void kswapd_stop(int nid); |
33398cf2 | 328 | |
1da177e4 | 329 | #ifdef CONFIG_SWAP |
be297968 CH |
330 | |
331 | #include <linux/blk_types.h> /* for bio_end_io_t */ | |
332 | ||
1da177e4 | 333 | /* linux/mm/page_io.c */ |
aca8bf32 | 334 | extern int swap_readpage(struct page *); |
1da177e4 | 335 | extern int swap_writepage(struct page *page, struct writeback_control *wbc); |
4246a0b6 | 336 | extern void end_swap_bio_write(struct bio *bio); |
1eec6702 | 337 | extern int __swap_writepage(struct page *page, struct writeback_control *wbc, |
4246a0b6 | 338 | bio_end_io_t end_write_func); |
62c230bc | 339 | extern int swap_set_page_dirty(struct page *page); |
1da177e4 | 340 | |
a509bc1a MG |
341 | int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page, |
342 | unsigned long nr_pages, sector_t start_block); | |
343 | int generic_swapfile_activate(struct swap_info_struct *, struct file *, | |
344 | sector_t *); | |
345 | ||
1da177e4 | 346 | /* linux/mm/swap_state.c */ |
4b3ef9da HY |
347 | /* One swap address space for each 64M swap space */ |
348 | #define SWAP_ADDRESS_SPACE_SHIFT 14 | |
349 | #define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT) | |
350 | extern struct address_space *swapper_spaces[]; | |
351 | #define swap_address_space(entry) \ | |
352 | (&swapper_spaces[swp_type(entry)][swp_offset(entry) \ | |
353 | >> SWAP_ADDRESS_SPACE_SHIFT]) | |
33806f06 | 354 | extern unsigned long total_swapcache_pages(void); |
1da177e4 | 355 | extern void show_swap_cache_info(void); |
5bc7b8ac | 356 | extern int add_to_swap(struct page *, struct list_head *list); |
73b1262f | 357 | extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t); |
2f772e6c | 358 | extern int __add_to_swap_cache(struct page *page, swp_entry_t entry); |
1da177e4 LT |
359 | extern void __delete_from_swap_cache(struct page *); |
360 | extern void delete_from_swap_cache(struct page *); | |
1da177e4 LT |
361 | extern void free_page_and_swap_cache(struct page *); |
362 | extern void free_pages_and_swap_cache(struct page **, int); | |
46017e95 | 363 | extern struct page *lookup_swap_cache(swp_entry_t); |
02098fea | 364 | extern struct page *read_swap_cache_async(swp_entry_t, gfp_t, |
46017e95 | 365 | struct vm_area_struct *vma, unsigned long addr); |
5b999aad DS |
366 | extern struct page *__read_swap_cache_async(swp_entry_t, gfp_t, |
367 | struct vm_area_struct *vma, unsigned long addr, | |
368 | bool *new_page_allocated); | |
02098fea | 369 | extern struct page *swapin_readahead(swp_entry_t, gfp_t, |
46017e95 HD |
370 | struct vm_area_struct *vma, unsigned long addr); |
371 | ||
1da177e4 | 372 | /* linux/mm/swapfile.c */ |
ec8acf20 | 373 | extern atomic_long_t nr_swap_pages; |
1da177e4 | 374 | extern long total_swap_pages; |
67afa38e | 375 | extern bool has_usable_swap(void); |
ec8acf20 SL |
376 | |
377 | /* Swap 50% full? Release swapcache more aggressively.. */ | |
378 | static inline bool vm_swap_full(void) | |
379 | { | |
380 | return atomic_long_read(&nr_swap_pages) * 2 < total_swap_pages; | |
381 | } | |
382 | ||
383 | static inline long get_nr_swap_pages(void) | |
384 | { | |
385 | return atomic_long_read(&nr_swap_pages); | |
386 | } | |
387 | ||
1da177e4 LT |
388 | extern void si_swapinfo(struct sysinfo *); |
389 | extern swp_entry_t get_swap_page(void); | |
910321ea | 390 | extern swp_entry_t get_swap_page_of_type(int); |
36005bae | 391 | extern int get_swap_pages(int n, swp_entry_t swp_entries[]); |
570a335b | 392 | extern int add_swap_count_continuation(swp_entry_t, gfp_t); |
aaa46865 | 393 | extern void swap_shmem_alloc(swp_entry_t); |
570a335b HD |
394 | extern int swap_duplicate(swp_entry_t); |
395 | extern int swapcache_prepare(swp_entry_t); | |
1da177e4 | 396 | extern void swap_free(swp_entry_t); |
0a31bc97 | 397 | extern void swapcache_free(swp_entry_t); |
7c00bafe | 398 | extern void swapcache_free_entries(swp_entry_t *entries, int n); |
2509ef26 | 399 | extern int free_swap_and_cache(swp_entry_t); |
7bf23687 | 400 | extern int swap_type_of(dev_t, sector_t, struct block_device **); |
f577eb30 | 401 | extern unsigned int count_swap_pages(int, int); |
d4906e1a | 402 | extern sector_t map_swap_page(struct page *, struct block_device **); |
3aef83e0 | 403 | extern sector_t swapdev_block(int, pgoff_t); |
bde05d1c | 404 | extern int page_swapcount(struct page *); |
e8c26ab6 | 405 | extern int __swp_swapcount(swp_entry_t entry); |
8334b962 | 406 | extern int swp_swapcount(swp_entry_t entry); |
f981c595 | 407 | extern struct swap_info_struct *page_swap_info(struct page *); |
6d0a07ed | 408 | extern bool reuse_swap_page(struct page *, int *); |
a2c43eed | 409 | extern int try_to_free_swap(struct page *); |
1da177e4 | 410 | struct backing_dev_info; |
4b3ef9da HY |
411 | extern int init_swap_address_space(unsigned int type, unsigned long nr_pages); |
412 | extern void exit_swap_address_space(unsigned int type); | |
1da177e4 | 413 | |
1da177e4 LT |
414 | #else /* CONFIG_SWAP */ |
415 | ||
d2cf5ad6 | 416 | #define swap_address_space(entry) (NULL) |
ec8acf20 | 417 | #define get_nr_swap_pages() 0L |
b962716b | 418 | #define total_swap_pages 0L |
33806f06 | 419 | #define total_swapcache_pages() 0UL |
ec8acf20 | 420 | #define vm_swap_full() 0 |
1da177e4 LT |
421 | |
422 | #define si_swapinfo(val) \ | |
423 | do { (val)->freeswap = (val)->totalswap = 0; } while (0) | |
9ae5b3c7 | 424 | /* only sparc can not include linux/pagemap.h in this file |
ea1754a0 | 425 | * so leave put_page and release_pages undeclared... */ |
1da177e4 | 426 | #define free_page_and_swap_cache(page) \ |
09cbfeaf | 427 | put_page(page) |
1da177e4 | 428 | #define free_pages_and_swap_cache(pages, nr) \ |
b745bc85 | 429 | release_pages((pages), (nr), false); |
1da177e4 | 430 | |
bd96b9eb CK |
431 | static inline void show_swap_cache_info(void) |
432 | { | |
433 | } | |
434 | ||
2509ef26 | 435 | #define free_swap_and_cache(swp) is_migration_entry(swp) |
cb4b86ba | 436 | #define swapcache_prepare(swp) is_migration_entry(swp) |
bd96b9eb | 437 | |
570a335b | 438 | static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask) |
355cfa73 | 439 | { |
570a335b HD |
440 | return 0; |
441 | } | |
442 | ||
aaa46865 HD |
443 | static inline void swap_shmem_alloc(swp_entry_t swp) |
444 | { | |
445 | } | |
446 | ||
570a335b HD |
447 | static inline int swap_duplicate(swp_entry_t swp) |
448 | { | |
449 | return 0; | |
355cfa73 KH |
450 | } |
451 | ||
bd96b9eb CK |
452 | static inline void swap_free(swp_entry_t swp) |
453 | { | |
454 | } | |
455 | ||
0a31bc97 | 456 | static inline void swapcache_free(swp_entry_t swp) |
cb4b86ba KH |
457 | { |
458 | } | |
459 | ||
02098fea | 460 | static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, |
bd96b9eb CK |
461 | struct vm_area_struct *vma, unsigned long addr) |
462 | { | |
463 | return NULL; | |
464 | } | |
465 | ||
9fab5619 HD |
466 | static inline int swap_writepage(struct page *p, struct writeback_control *wbc) |
467 | { | |
468 | return 0; | |
469 | } | |
470 | ||
bd96b9eb CK |
471 | static inline struct page *lookup_swap_cache(swp_entry_t swp) |
472 | { | |
473 | return NULL; | |
474 | } | |
475 | ||
5bc7b8ac | 476 | static inline int add_to_swap(struct page *page, struct list_head *list) |
60371d97 HD |
477 | { |
478 | return 0; | |
479 | } | |
480 | ||
73b1262f HD |
481 | static inline int add_to_swap_cache(struct page *page, swp_entry_t entry, |
482 | gfp_t gfp_mask) | |
bd96b9eb | 483 | { |
73b1262f | 484 | return -1; |
bd96b9eb CK |
485 | } |
486 | ||
487 | static inline void __delete_from_swap_cache(struct page *page) | |
488 | { | |
489 | } | |
490 | ||
491 | static inline void delete_from_swap_cache(struct page *page) | |
492 | { | |
493 | } | |
494 | ||
bde05d1c HD |
495 | static inline int page_swapcount(struct page *page) |
496 | { | |
497 | return 0; | |
498 | } | |
499 | ||
e8c26ab6 TC |
500 | static inline int __swp_swapcount(swp_entry_t entry) |
501 | { | |
502 | return 0; | |
503 | } | |
504 | ||
8334b962 MK |
505 | static inline int swp_swapcount(swp_entry_t entry) |
506 | { | |
507 | return 0; | |
508 | } | |
509 | ||
6d0a07ed AA |
510 | #define reuse_swap_page(page, total_mapcount) \ |
511 | (page_trans_huge_mapcount(page, total_mapcount) == 1) | |
1da177e4 | 512 | |
a2c43eed | 513 | static inline int try_to_free_swap(struct page *page) |
68a22394 RR |
514 | { |
515 | return 0; | |
516 | } | |
517 | ||
1da177e4 LT |
518 | static inline swp_entry_t get_swap_page(void) |
519 | { | |
520 | swp_entry_t entry; | |
521 | entry.val = 0; | |
522 | return entry; | |
523 | } | |
524 | ||
1da177e4 | 525 | #endif /* CONFIG_SWAP */ |
6f2cb2f1 VD |
526 | |
527 | #ifdef CONFIG_MEMCG | |
528 | static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg) | |
529 | { | |
4550c4e1 JW |
530 | /* Cgroup2 doesn't have per-cgroup swappiness */ |
531 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
532 | return vm_swappiness; | |
533 | ||
6f2cb2f1 VD |
534 | /* root ? */ |
535 | if (mem_cgroup_disabled() || !memcg->css.parent) | |
536 | return vm_swappiness; | |
537 | ||
538 | return memcg->swappiness; | |
539 | } | |
540 | ||
541 | #else | |
542 | static inline int mem_cgroup_swappiness(struct mem_cgroup *mem) | |
543 | { | |
544 | return vm_swappiness; | |
545 | } | |
546 | #endif | |
547 | ||
548 | #ifdef CONFIG_MEMCG_SWAP | |
549 | extern void mem_cgroup_swapout(struct page *page, swp_entry_t entry); | |
550 | extern int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry); | |
551 | extern void mem_cgroup_uncharge_swap(swp_entry_t entry); | |
d8b38438 | 552 | extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg); |
5ccc5aba | 553 | extern bool mem_cgroup_swap_full(struct page *page); |
6f2cb2f1 VD |
554 | #else |
555 | static inline void mem_cgroup_swapout(struct page *page, swp_entry_t entry) | |
556 | { | |
557 | } | |
558 | ||
559 | static inline int mem_cgroup_try_charge_swap(struct page *page, | |
560 | swp_entry_t entry) | |
561 | { | |
562 | return 0; | |
563 | } | |
564 | ||
565 | static inline void mem_cgroup_uncharge_swap(swp_entry_t entry) | |
566 | { | |
567 | } | |
d8b38438 VD |
568 | |
569 | static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) | |
570 | { | |
571 | return get_nr_swap_pages(); | |
572 | } | |
5ccc5aba VD |
573 | |
574 | static inline bool mem_cgroup_swap_full(struct page *page) | |
575 | { | |
576 | return vm_swap_full(); | |
577 | } | |
6f2cb2f1 VD |
578 | #endif |
579 | ||
1da177e4 LT |
580 | #endif /* __KERNEL__*/ |
581 | #endif /* _LINUX_SWAP_H */ |