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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> |
1da177e4 LT |
13 | #include <asm/page.h> |
14 | ||
8bc719d3 MS |
15 | struct notifier_block; |
16 | ||
ab954160 AM |
17 | struct bio; |
18 | ||
1da177e4 LT |
19 | #define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */ |
20 | #define SWAP_FLAG_PRIO_MASK 0x7fff | |
21 | #define SWAP_FLAG_PRIO_SHIFT 0 | |
33994466 | 22 | #define SWAP_FLAG_DISCARD 0x10000 /* discard swap cluster after use */ |
1da177e4 | 23 | |
d15cab97 HD |
24 | #define SWAP_FLAGS_VALID (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \ |
25 | SWAP_FLAG_DISCARD) | |
26 | ||
1da177e4 LT |
27 | static inline int current_is_kswapd(void) |
28 | { | |
29 | return current->flags & PF_KSWAPD; | |
30 | } | |
31 | ||
32 | /* | |
33 | * MAX_SWAPFILES defines the maximum number of swaptypes: things which can | |
34 | * be swapped to. The swap type and the offset into that swap type are | |
35 | * encoded into pte's and into pgoff_t's in the swapcache. Using five bits | |
36 | * for the type means that the maximum number of swapcache pages is 27 bits | |
37 | * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs | |
38 | * the type/offset into the pte as 5/27 as well. | |
39 | */ | |
40 | #define MAX_SWAPFILES_SHIFT 5 | |
a7420aa5 AK |
41 | |
42 | /* | |
43 | * Use some of the swap files numbers for other purposes. This | |
44 | * is a convenient way to hook into the VM to trigger special | |
45 | * actions on faults. | |
46 | */ | |
47 | ||
48 | /* | |
49 | * NUMA node memory migration support | |
50 | */ | |
51 | #ifdef CONFIG_MIGRATION | |
52 | #define SWP_MIGRATION_NUM 2 | |
53 | #define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM) | |
54 | #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1) | |
0697212a | 55 | #else |
a7420aa5 | 56 | #define SWP_MIGRATION_NUM 0 |
0697212a | 57 | #endif |
1da177e4 | 58 | |
a7420aa5 AK |
59 | /* |
60 | * Handling of hardware poisoned pages with memory corruption. | |
61 | */ | |
62 | #ifdef CONFIG_MEMORY_FAILURE | |
63 | #define SWP_HWPOISON_NUM 1 | |
64 | #define SWP_HWPOISON MAX_SWAPFILES | |
65 | #else | |
66 | #define SWP_HWPOISON_NUM 0 | |
67 | #endif | |
68 | ||
69 | #define MAX_SWAPFILES \ | |
70 | ((1 << MAX_SWAPFILES_SHIFT) - SWP_MIGRATION_NUM - SWP_HWPOISON_NUM) | |
71 | ||
1da177e4 LT |
72 | /* |
73 | * Magic header for a swap area. The first part of the union is | |
74 | * what the swap magic looks like for the old (limited to 128MB) | |
75 | * swap area format, the second part of the union adds - in the | |
76 | * old reserved area - some extra information. Note that the first | |
77 | * kilobyte is reserved for boot loader or disk label stuff... | |
78 | * | |
79 | * Having the magic at the end of the PAGE_SIZE makes detecting swap | |
80 | * areas somewhat tricky on machines that support multiple page sizes. | |
81 | * For 2.5 we'll probably want to move the magic to just beyond the | |
82 | * bootbits... | |
83 | */ | |
84 | union swap_header { | |
85 | struct { | |
86 | char reserved[PAGE_SIZE - 10]; | |
87 | char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ | |
88 | } magic; | |
89 | struct { | |
e8f03d02 AD |
90 | char bootbits[1024]; /* Space for disklabel etc. */ |
91 | __u32 version; | |
92 | __u32 last_page; | |
93 | __u32 nr_badpages; | |
94 | unsigned char sws_uuid[16]; | |
95 | unsigned char sws_volume[16]; | |
96 | __u32 padding[117]; | |
97 | __u32 badpages[1]; | |
1da177e4 LT |
98 | } info; |
99 | }; | |
100 | ||
101 | /* A swap entry has to fit into a "unsigned long", as | |
102 | * the entry is hidden in the "index" field of the | |
103 | * swapper address space. | |
104 | */ | |
105 | typedef struct { | |
106 | unsigned long val; | |
107 | } swp_entry_t; | |
108 | ||
109 | /* | |
110 | * current->reclaim_state points to one of these when a task is running | |
111 | * memory reclaim | |
112 | */ | |
113 | struct reclaim_state { | |
114 | unsigned long reclaimed_slab; | |
115 | }; | |
116 | ||
117 | #ifdef __KERNEL__ | |
118 | ||
119 | struct address_space; | |
120 | struct sysinfo; | |
121 | struct writeback_control; | |
122 | struct zone; | |
123 | ||
124 | /* | |
125 | * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of | |
126 | * disk blocks. A list of swap extents maps the entire swapfile. (Where the | |
127 | * term `swapfile' refers to either a blockdevice or an IS_REG file. Apart | |
128 | * from setup, they're handled identically. | |
129 | * | |
130 | * We always assume that blocks are of size PAGE_SIZE. | |
131 | */ | |
132 | struct swap_extent { | |
133 | struct list_head list; | |
134 | pgoff_t start_page; | |
135 | pgoff_t nr_pages; | |
136 | sector_t start_block; | |
137 | }; | |
138 | ||
139 | /* | |
140 | * Max bad pages in the new format.. | |
141 | */ | |
142 | #define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x) | |
143 | #define MAX_SWAP_BADPAGES \ | |
144 | ((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int)) | |
145 | ||
146 | enum { | |
147 | SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ | |
148 | SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ | |
33994466 | 149 | SWP_DISCARDABLE = (1 << 2), /* swapon+blkdev support discard */ |
7992fde7 | 150 | SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */ |
20137a49 | 151 | SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */ |
570a335b | 152 | SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */ |
b2725643 | 153 | SWP_BLKDEV = (1 << 6), /* its a block device */ |
62c230bc | 154 | SWP_FILE = (1 << 7), /* set after swap_activate success */ |
52b7efdb HD |
155 | /* add others here before... */ |
156 | SWP_SCANNING = (1 << 8), /* 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 | |
8afdcece MG |
162 | /* |
163 | * Ratio between the present memory in the zone and the "gap" that | |
164 | * we're allowing kswapd to shrink in addition to the per-zone high | |
165 | * wmark, even for zones that already have the high wmark satisfied, | |
166 | * in order to provide better per-zone lru behavior. We are ok to | |
167 | * spend not more than 1% of the memory for this zone balancing "gap". | |
168 | */ | |
169 | #define KSWAPD_ZONE_BALANCE_GAP_RATIO 100 | |
170 | ||
570a335b HD |
171 | #define SWAP_MAP_MAX 0x3e /* Max duplication count, in first swap_map */ |
172 | #define SWAP_MAP_BAD 0x3f /* Note pageblock is bad, in first swap_map */ | |
173 | #define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */ | |
174 | #define SWAP_CONT_MAX 0x7f /* Max count, in each swap_map continuation */ | |
175 | #define COUNT_CONTINUED 0x80 /* See swap_map continuation for full count */ | |
aaa46865 | 176 | #define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs, in first swap_map */ |
253d553b | 177 | |
1da177e4 LT |
178 | /* |
179 | * The in-memory structure used to track swap areas. | |
1da177e4 LT |
180 | */ |
181 | struct swap_info_struct { | |
efa90a98 HD |
182 | unsigned long flags; /* SWP_USED etc: see above */ |
183 | signed short prio; /* swap priority of this type */ | |
184 | signed char type; /* strange name for an index */ | |
185 | signed char next; /* next type on the swap list */ | |
7509765a HD |
186 | unsigned int max; /* extent of the swap_map */ |
187 | unsigned char *swap_map; /* vmalloc'ed array of usage counts */ | |
188 | unsigned int lowest_bit; /* index of first free in swap_map */ | |
189 | unsigned int highest_bit; /* index of last free in swap_map */ | |
190 | unsigned int pages; /* total of usable pages of swap */ | |
191 | unsigned int inuse_pages; /* number of those currently in use */ | |
192 | unsigned int cluster_next; /* likely index for next allocation */ | |
193 | unsigned int cluster_nr; /* countdown to next cluster search */ | |
7992fde7 HD |
194 | unsigned int lowest_alloc; /* while preparing discard cluster */ |
195 | unsigned int highest_alloc; /* while preparing discard cluster */ | |
7509765a HD |
196 | struct swap_extent *curr_swap_extent; |
197 | struct swap_extent first_swap_extent; | |
198 | struct block_device *bdev; /* swap device or bdev of swap file */ | |
199 | struct file *swap_file; /* seldom referenced */ | |
200 | unsigned int old_block_size; /* seldom referenced */ | |
38b5faf4 DM |
201 | #ifdef CONFIG_FRONTSWAP |
202 | unsigned long *frontswap_map; /* frontswap in-use, one bit per page */ | |
203 | atomic_t frontswap_pages; /* frontswap pages in-use counter */ | |
204 | #endif | |
1da177e4 LT |
205 | }; |
206 | ||
207 | struct swap_list_t { | |
208 | int head; /* head of priority-ordered swapfile list */ | |
209 | int next; /* swapfile to be used next */ | |
210 | }; | |
211 | ||
212 | /* Swap 50% full? Release swapcache more aggressively.. */ | |
213 | #define vm_swap_full() (nr_swap_pages*2 < total_swap_pages) | |
214 | ||
1da177e4 LT |
215 | /* linux/mm/page_alloc.c */ |
216 | extern unsigned long totalram_pages; | |
cb45b0e9 | 217 | extern unsigned long totalreserve_pages; |
ab8fabd4 | 218 | extern unsigned long dirty_balance_reserve; |
1da177e4 LT |
219 | extern unsigned int nr_free_buffer_pages(void); |
220 | extern unsigned int nr_free_pagecache_pages(void); | |
221 | ||
96177299 CL |
222 | /* Definition of global_page_state not available yet */ |
223 | #define nr_free_pages() global_page_state(NR_FREE_PAGES) | |
224 | ||
225 | ||
1da177e4 | 226 | /* linux/mm/swap.c */ |
f04e9ebb KM |
227 | extern void __lru_cache_add(struct page *, enum lru_list lru); |
228 | extern void lru_cache_add_lru(struct page *, enum lru_list lru); | |
fa9add64 HD |
229 | extern void lru_add_page_tail(struct page *page, struct page *page_tail, |
230 | struct lruvec *lruvec); | |
b3c97528 HH |
231 | extern void activate_page(struct page *); |
232 | extern void mark_page_accessed(struct page *); | |
1da177e4 | 233 | extern void lru_add_drain(void); |
f0cb3c76 | 234 | extern void lru_add_drain_cpu(int cpu); |
053837fc | 235 | extern int lru_add_drain_all(void); |
ac6aadb2 | 236 | extern void rotate_reclaimable_page(struct page *page); |
31560180 | 237 | extern void deactivate_page(struct page *page); |
1da177e4 LT |
238 | extern void swap_setup(void); |
239 | ||
894bc310 LS |
240 | extern void add_page_to_unevictable_list(struct page *page); |
241 | ||
f04e9ebb KM |
242 | /** |
243 | * lru_cache_add: add a page to the page lists | |
244 | * @page: the page to add | |
245 | */ | |
4f98a2fe | 246 | static inline void lru_cache_add_anon(struct page *page) |
f04e9ebb | 247 | { |
4f98a2fe | 248 | __lru_cache_add(page, LRU_INACTIVE_ANON); |
f04e9ebb KM |
249 | } |
250 | ||
4f98a2fe RR |
251 | static inline void lru_cache_add_file(struct page *page) |
252 | { | |
253 | __lru_cache_add(page, LRU_INACTIVE_FILE); | |
254 | } | |
255 | ||
1da177e4 | 256 | /* linux/mm/vmscan.c */ |
dac1d27b | 257 | extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, |
327c0e96 | 258 | gfp_t gfp_mask, nodemask_t *mask); |
f3fd4a61 | 259 | extern int __isolate_lru_page(struct page *page, isolate_mode_t mode); |
185efc0f JW |
260 | extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem, |
261 | gfp_t gfp_mask, bool noswap); | |
262 | extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem, | |
263 | gfp_t gfp_mask, bool noswap, | |
264 | struct zone *zone, | |
265 | unsigned long *nr_scanned); | |
69e05944 | 266 | extern unsigned long shrink_all_memory(unsigned long nr_pages); |
1da177e4 | 267 | extern int vm_swappiness; |
b20a3503 | 268 | extern int remove_mapping(struct address_space *mapping, struct page *page); |
bd1e22b8 | 269 | extern long vm_total_pages; |
b20a3503 | 270 | |
9eeff239 CL |
271 | #ifdef CONFIG_NUMA |
272 | extern int zone_reclaim_mode; | |
9614634f | 273 | extern int sysctl_min_unmapped_ratio; |
0ff38490 | 274 | extern int sysctl_min_slab_ratio; |
9eeff239 CL |
275 | extern int zone_reclaim(struct zone *, gfp_t, unsigned int); |
276 | #else | |
277 | #define zone_reclaim_mode 0 | |
278 | static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order) | |
279 | { | |
280 | return 0; | |
281 | } | |
282 | #endif | |
283 | ||
39b5f29a | 284 | extern int page_evictable(struct page *page); |
24513264 | 285 | extern void check_move_unevictable_pages(struct page **, int nr_pages); |
af936a16 LS |
286 | |
287 | extern unsigned long scan_unevictable_pages; | |
8d65af78 | 288 | extern int scan_unevictable_handler(struct ctl_table *, int, |
af936a16 | 289 | void __user *, size_t *, loff_t *); |
e4455abb | 290 | #ifdef CONFIG_NUMA |
af936a16 LS |
291 | extern int scan_unevictable_register_node(struct node *node); |
292 | extern void scan_unevictable_unregister_node(struct node *node); | |
e4455abb TLSC |
293 | #else |
294 | static inline int scan_unevictable_register_node(struct node *node) | |
295 | { | |
296 | return 0; | |
297 | } | |
298 | static inline void scan_unevictable_unregister_node(struct node *node) | |
299 | { | |
300 | } | |
301 | #endif | |
894bc310 | 302 | |
3218ae14 | 303 | extern int kswapd_run(int nid); |
8fe23e05 | 304 | extern void kswapd_stop(int nid); |
c255a458 | 305 | #ifdef CONFIG_MEMCG |
1f4c025b KH |
306 | extern int mem_cgroup_swappiness(struct mem_cgroup *mem); |
307 | #else | |
308 | static inline int mem_cgroup_swappiness(struct mem_cgroup *mem) | |
309 | { | |
310 | return vm_swappiness; | |
311 | } | |
312 | #endif | |
c255a458 | 313 | #ifdef CONFIG_MEMCG_SWAP |
dac23b0d MH |
314 | extern void mem_cgroup_uncharge_swap(swp_entry_t ent); |
315 | #else | |
316 | static inline void mem_cgroup_uncharge_swap(swp_entry_t ent) | |
317 | { | |
318 | } | |
319 | #endif | |
1da177e4 LT |
320 | #ifdef CONFIG_SWAP |
321 | /* linux/mm/page_io.c */ | |
aca8bf32 | 322 | extern int swap_readpage(struct page *); |
1da177e4 | 323 | extern int swap_writepage(struct page *page, struct writeback_control *wbc); |
62c230bc | 324 | extern int swap_set_page_dirty(struct page *page); |
6712ecf8 | 325 | extern void end_swap_bio_read(struct bio *bio, int err); |
1da177e4 | 326 | |
a509bc1a MG |
327 | int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page, |
328 | unsigned long nr_pages, sector_t start_block); | |
329 | int generic_swapfile_activate(struct swap_info_struct *, struct file *, | |
330 | sector_t *); | |
331 | ||
1da177e4 | 332 | /* linux/mm/swap_state.c */ |
33806f06 SL |
333 | extern struct address_space swapper_spaces[]; |
334 | #define swap_address_space(entry) (&swapper_spaces[swp_type(entry)]) | |
335 | extern unsigned long total_swapcache_pages(void); | |
1da177e4 | 336 | extern void show_swap_cache_info(void); |
ac47b003 | 337 | extern int add_to_swap(struct page *); |
73b1262f | 338 | extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t); |
1da177e4 LT |
339 | extern void __delete_from_swap_cache(struct page *); |
340 | extern void delete_from_swap_cache(struct page *); | |
1da177e4 LT |
341 | extern void free_page_and_swap_cache(struct page *); |
342 | extern void free_pages_and_swap_cache(struct page **, int); | |
46017e95 | 343 | extern struct page *lookup_swap_cache(swp_entry_t); |
02098fea | 344 | extern struct page *read_swap_cache_async(swp_entry_t, gfp_t, |
46017e95 | 345 | struct vm_area_struct *vma, unsigned long addr); |
02098fea | 346 | extern struct page *swapin_readahead(swp_entry_t, gfp_t, |
46017e95 HD |
347 | struct vm_area_struct *vma, unsigned long addr); |
348 | ||
1da177e4 | 349 | /* linux/mm/swapfile.c */ |
b962716b | 350 | extern long nr_swap_pages; |
1da177e4 | 351 | extern long total_swap_pages; |
1da177e4 LT |
352 | extern void si_swapinfo(struct sysinfo *); |
353 | extern swp_entry_t get_swap_page(void); | |
910321ea | 354 | extern swp_entry_t get_swap_page_of_type(int); |
570a335b | 355 | extern int add_swap_count_continuation(swp_entry_t, gfp_t); |
aaa46865 | 356 | extern void swap_shmem_alloc(swp_entry_t); |
570a335b HD |
357 | extern int swap_duplicate(swp_entry_t); |
358 | extern int swapcache_prepare(swp_entry_t); | |
1da177e4 | 359 | extern void swap_free(swp_entry_t); |
cb4b86ba | 360 | extern void swapcache_free(swp_entry_t, struct page *page); |
2509ef26 | 361 | extern int free_swap_and_cache(swp_entry_t); |
7bf23687 | 362 | extern int swap_type_of(dev_t, sector_t, struct block_device **); |
f577eb30 | 363 | extern unsigned int count_swap_pages(int, int); |
d4906e1a | 364 | extern sector_t map_swap_page(struct page *, struct block_device **); |
3aef83e0 | 365 | extern sector_t swapdev_block(int, pgoff_t); |
bde05d1c | 366 | extern int page_swapcount(struct page *); |
f981c595 | 367 | extern struct swap_info_struct *page_swap_info(struct page *); |
7b1fe597 | 368 | extern int reuse_swap_page(struct page *); |
a2c43eed | 369 | extern int try_to_free_swap(struct page *); |
1da177e4 LT |
370 | struct backing_dev_info; |
371 | ||
c255a458 | 372 | #ifdef CONFIG_MEMCG |
8a9478ca KH |
373 | extern void |
374 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout); | |
d13d1443 | 375 | #else |
8c7c6e34 | 376 | static inline void |
8a9478ca | 377 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) |
8c7c6e34 KH |
378 | { |
379 | } | |
380 | #endif | |
d13d1443 | 381 | |
1da177e4 LT |
382 | #else /* CONFIG_SWAP */ |
383 | ||
b962716b HD |
384 | #define nr_swap_pages 0L |
385 | #define total_swap_pages 0L | |
33806f06 | 386 | #define total_swapcache_pages() 0UL |
1da177e4 LT |
387 | |
388 | #define si_swapinfo(val) \ | |
389 | do { (val)->freeswap = (val)->totalswap = 0; } while (0) | |
9ae5b3c7 OH |
390 | /* only sparc can not include linux/pagemap.h in this file |
391 | * so leave page_cache_release and release_pages undeclared... */ | |
1da177e4 LT |
392 | #define free_page_and_swap_cache(page) \ |
393 | page_cache_release(page) | |
394 | #define free_pages_and_swap_cache(pages, nr) \ | |
395 | release_pages((pages), (nr), 0); | |
396 | ||
bd96b9eb CK |
397 | static inline void show_swap_cache_info(void) |
398 | { | |
399 | } | |
400 | ||
2509ef26 | 401 | #define free_swap_and_cache(swp) is_migration_entry(swp) |
cb4b86ba | 402 | #define swapcache_prepare(swp) is_migration_entry(swp) |
bd96b9eb | 403 | |
570a335b | 404 | static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask) |
355cfa73 | 405 | { |
570a335b HD |
406 | return 0; |
407 | } | |
408 | ||
aaa46865 HD |
409 | static inline void swap_shmem_alloc(swp_entry_t swp) |
410 | { | |
411 | } | |
412 | ||
570a335b HD |
413 | static inline int swap_duplicate(swp_entry_t swp) |
414 | { | |
415 | return 0; | |
355cfa73 KH |
416 | } |
417 | ||
bd96b9eb CK |
418 | static inline void swap_free(swp_entry_t swp) |
419 | { | |
420 | } | |
421 | ||
cb4b86ba KH |
422 | static inline void swapcache_free(swp_entry_t swp, struct page *page) |
423 | { | |
424 | } | |
425 | ||
02098fea | 426 | static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, |
bd96b9eb CK |
427 | struct vm_area_struct *vma, unsigned long addr) |
428 | { | |
429 | return NULL; | |
430 | } | |
431 | ||
9fab5619 HD |
432 | static inline int swap_writepage(struct page *p, struct writeback_control *wbc) |
433 | { | |
434 | return 0; | |
435 | } | |
436 | ||
bd96b9eb CK |
437 | static inline struct page *lookup_swap_cache(swp_entry_t swp) |
438 | { | |
439 | return NULL; | |
440 | } | |
441 | ||
60371d97 HD |
442 | static inline int add_to_swap(struct page *page) |
443 | { | |
444 | return 0; | |
445 | } | |
446 | ||
73b1262f HD |
447 | static inline int add_to_swap_cache(struct page *page, swp_entry_t entry, |
448 | gfp_t gfp_mask) | |
bd96b9eb | 449 | { |
73b1262f | 450 | return -1; |
bd96b9eb CK |
451 | } |
452 | ||
453 | static inline void __delete_from_swap_cache(struct page *page) | |
454 | { | |
455 | } | |
456 | ||
457 | static inline void delete_from_swap_cache(struct page *page) | |
458 | { | |
459 | } | |
460 | ||
bde05d1c HD |
461 | static inline int page_swapcount(struct page *page) |
462 | { | |
463 | return 0; | |
464 | } | |
465 | ||
7b1fe597 | 466 | #define reuse_swap_page(page) (page_mapcount(page) == 1) |
1da177e4 | 467 | |
a2c43eed | 468 | static inline int try_to_free_swap(struct page *page) |
68a22394 RR |
469 | { |
470 | return 0; | |
471 | } | |
472 | ||
1da177e4 LT |
473 | static inline swp_entry_t get_swap_page(void) |
474 | { | |
475 | swp_entry_t entry; | |
476 | entry.val = 0; | |
477 | return entry; | |
478 | } | |
479 | ||
e767e056 DN |
480 | static inline void |
481 | mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent) | |
482 | { | |
483 | } | |
484 | ||
1da177e4 LT |
485 | #endif /* CONFIG_SWAP */ |
486 | #endif /* __KERNEL__*/ | |
487 | #endif /* _LINUX_SWAP_H */ |