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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> |
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) | |
d15cab97 | 30 | |
1da177e4 LT |
31 | static inline int current_is_kswapd(void) |
32 | { | |
33 | return current->flags & PF_KSWAPD; | |
34 | } | |
35 | ||
36 | /* | |
37 | * MAX_SWAPFILES defines the maximum number of swaptypes: things which can | |
38 | * be swapped to. The swap type and the offset into that swap type are | |
39 | * encoded into pte's and into pgoff_t's in the swapcache. Using five bits | |
40 | * for the type means that the maximum number of swapcache pages is 27 bits | |
41 | * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs | |
42 | * the type/offset into the pte as 5/27 as well. | |
43 | */ | |
44 | #define MAX_SWAPFILES_SHIFT 5 | |
a7420aa5 AK |
45 | |
46 | /* | |
47 | * Use some of the swap files numbers for other purposes. This | |
48 | * is a convenient way to hook into the VM to trigger special | |
49 | * actions on faults. | |
50 | */ | |
51 | ||
52 | /* | |
53 | * NUMA node memory migration support | |
54 | */ | |
55 | #ifdef CONFIG_MIGRATION | |
56 | #define SWP_MIGRATION_NUM 2 | |
57 | #define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM) | |
58 | #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1) | |
0697212a | 59 | #else |
a7420aa5 | 60 | #define SWP_MIGRATION_NUM 0 |
0697212a | 61 | #endif |
1da177e4 | 62 | |
a7420aa5 AK |
63 | /* |
64 | * Handling of hardware poisoned pages with memory corruption. | |
65 | */ | |
66 | #ifdef CONFIG_MEMORY_FAILURE | |
67 | #define SWP_HWPOISON_NUM 1 | |
68 | #define SWP_HWPOISON MAX_SWAPFILES | |
69 | #else | |
70 | #define SWP_HWPOISON_NUM 0 | |
71 | #endif | |
72 | ||
73 | #define MAX_SWAPFILES \ | |
74 | ((1 << MAX_SWAPFILES_SHIFT) - SWP_MIGRATION_NUM - SWP_HWPOISON_NUM) | |
75 | ||
1da177e4 LT |
76 | /* |
77 | * Magic header for a swap area. The first part of the union is | |
78 | * what the swap magic looks like for the old (limited to 128MB) | |
79 | * swap area format, the second part of the union adds - in the | |
80 | * old reserved area - some extra information. Note that the first | |
81 | * kilobyte is reserved for boot loader or disk label stuff... | |
82 | * | |
83 | * Having the magic at the end of the PAGE_SIZE makes detecting swap | |
84 | * areas somewhat tricky on machines that support multiple page sizes. | |
85 | * For 2.5 we'll probably want to move the magic to just beyond the | |
86 | * bootbits... | |
87 | */ | |
88 | union swap_header { | |
89 | struct { | |
90 | char reserved[PAGE_SIZE - 10]; | |
91 | char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */ | |
92 | } magic; | |
93 | struct { | |
e8f03d02 AD |
94 | char bootbits[1024]; /* Space for disklabel etc. */ |
95 | __u32 version; | |
96 | __u32 last_page; | |
97 | __u32 nr_badpages; | |
98 | unsigned char sws_uuid[16]; | |
99 | unsigned char sws_volume[16]; | |
100 | __u32 padding[117]; | |
101 | __u32 badpages[1]; | |
1da177e4 LT |
102 | } info; |
103 | }; | |
104 | ||
1da177e4 LT |
105 | /* |
106 | * current->reclaim_state points to one of these when a task is running | |
107 | * memory reclaim | |
108 | */ | |
109 | struct reclaim_state { | |
110 | unsigned long reclaimed_slab; | |
111 | }; | |
112 | ||
113 | #ifdef __KERNEL__ | |
114 | ||
115 | struct address_space; | |
116 | struct sysinfo; | |
117 | struct writeback_control; | |
118 | struct zone; | |
119 | ||
120 | /* | |
121 | * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of | |
122 | * disk blocks. A list of swap extents maps the entire swapfile. (Where the | |
123 | * term `swapfile' refers to either a blockdevice or an IS_REG file. Apart | |
124 | * from setup, they're handled identically. | |
125 | * | |
126 | * We always assume that blocks are of size PAGE_SIZE. | |
127 | */ | |
128 | struct swap_extent { | |
129 | struct list_head list; | |
130 | pgoff_t start_page; | |
131 | pgoff_t nr_pages; | |
132 | sector_t start_block; | |
133 | }; | |
134 | ||
135 | /* | |
136 | * Max bad pages in the new format.. | |
137 | */ | |
138 | #define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x) | |
139 | #define MAX_SWAP_BADPAGES \ | |
140 | ((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int)) | |
141 | ||
142 | enum { | |
143 | SWP_USED = (1 << 0), /* is slot in swap_info[] used? */ | |
144 | SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */ | |
dcf6b7dd | 145 | SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */ |
7992fde7 | 146 | SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */ |
20137a49 | 147 | SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */ |
570a335b | 148 | SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */ |
b2725643 | 149 | SWP_BLKDEV = (1 << 6), /* its a block device */ |
62c230bc | 150 | SWP_FILE = (1 << 7), /* set after swap_activate success */ |
dcf6b7dd RA |
151 | SWP_AREA_DISCARD = (1 << 8), /* single-time swap area discards */ |
152 | SWP_PAGE_DISCARD = (1 << 9), /* freed swap page-cluster discards */ | |
52b7efdb | 153 | /* add others here before... */ |
dcf6b7dd | 154 | SWP_SCANNING = (1 << 10), /* refcount in scan_swap_map */ |
1da177e4 LT |
155 | }; |
156 | ||
d778df51 | 157 | #define SWAP_CLUSTER_MAX 32UL |
748446bb | 158 | #define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX |
1da177e4 | 159 | |
570a335b HD |
160 | #define SWAP_MAP_MAX 0x3e /* Max duplication count, in first swap_map */ |
161 | #define SWAP_MAP_BAD 0x3f /* Note pageblock is bad, in first swap_map */ | |
162 | #define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */ | |
163 | #define SWAP_CONT_MAX 0x7f /* Max count, in each swap_map continuation */ | |
164 | #define COUNT_CONTINUED 0x80 /* See swap_map continuation for full count */ | |
aaa46865 | 165 | #define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs, in first swap_map */ |
253d553b | 166 | |
2a8f9449 SL |
167 | /* |
168 | * We use this to track usage of a cluster. A cluster is a block of swap disk | |
169 | * space with SWAPFILE_CLUSTER pages long and naturally aligns in disk. All | |
170 | * free clusters are organized into a list. We fetch an entry from the list to | |
171 | * get a free cluster. | |
172 | * | |
173 | * The data field stores next cluster if the cluster is free or cluster usage | |
174 | * counter otherwise. The flags field determines if a cluster is free. This is | |
175 | * protected by swap_info_struct.lock. | |
176 | */ | |
177 | struct swap_cluster_info { | |
178 | unsigned int data:24; | |
179 | unsigned int flags:8; | |
180 | }; | |
181 | #define CLUSTER_FLAG_FREE 1 /* This cluster is free */ | |
182 | #define CLUSTER_FLAG_NEXT_NULL 2 /* This cluster has no next cluster */ | |
183 | ||
ebc2a1a6 SL |
184 | /* |
185 | * We assign a cluster to each CPU, so each CPU can allocate swap entry from | |
186 | * its own cluster and swapout sequentially. The purpose is to optimize swapout | |
187 | * throughput. | |
188 | */ | |
189 | struct percpu_cluster { | |
190 | struct swap_cluster_info index; /* Current cluster index */ | |
191 | unsigned int next; /* Likely next allocation offset */ | |
192 | }; | |
193 | ||
6b534915 HY |
194 | struct swap_cluster_list { |
195 | struct swap_cluster_info head; | |
196 | struct swap_cluster_info tail; | |
197 | }; | |
198 | ||
1da177e4 LT |
199 | /* |
200 | * The in-memory structure used to track swap areas. | |
1da177e4 LT |
201 | */ |
202 | struct swap_info_struct { | |
efa90a98 HD |
203 | unsigned long flags; /* SWP_USED etc: see above */ |
204 | signed short prio; /* swap priority of this type */ | |
18ab4d4c DS |
205 | struct plist_node list; /* entry in swap_active_head */ |
206 | struct plist_node avail_list; /* entry in swap_avail_head */ | |
efa90a98 | 207 | signed char type; /* strange name for an index */ |
7509765a HD |
208 | unsigned int max; /* extent of the swap_map */ |
209 | unsigned char *swap_map; /* vmalloc'ed array of usage counts */ | |
2a8f9449 | 210 | struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */ |
6b534915 | 211 | struct swap_cluster_list free_clusters; /* free clusters list */ |
7509765a HD |
212 | unsigned int lowest_bit; /* index of first free in swap_map */ |
213 | unsigned int highest_bit; /* index of last free in swap_map */ | |
214 | unsigned int pages; /* total of usable pages of swap */ | |
215 | unsigned int inuse_pages; /* number of those currently in use */ | |
216 | unsigned int cluster_next; /* likely index for next allocation */ | |
217 | unsigned int cluster_nr; /* countdown to next cluster search */ | |
ebc2a1a6 | 218 | struct percpu_cluster __percpu *percpu_cluster; /* per cpu's swap location */ |
7509765a HD |
219 | struct swap_extent *curr_swap_extent; |
220 | struct swap_extent first_swap_extent; | |
221 | struct block_device *bdev; /* swap device or bdev of swap file */ | |
222 | struct file *swap_file; /* seldom referenced */ | |
223 | unsigned int old_block_size; /* seldom referenced */ | |
38b5faf4 DM |
224 | #ifdef CONFIG_FRONTSWAP |
225 | unsigned long *frontswap_map; /* frontswap in-use, one bit per page */ | |
226 | atomic_t frontswap_pages; /* frontswap pages in-use counter */ | |
227 | #endif | |
ec8acf20 SL |
228 | spinlock_t lock; /* |
229 | * protect map scan related fields like | |
230 | * swap_map, lowest_bit, highest_bit, | |
231 | * inuse_pages, cluster_next, | |
815c2c54 SL |
232 | * cluster_nr, lowest_alloc, |
233 | * highest_alloc, free/discard cluster | |
234 | * list. other fields are only changed | |
235 | * at swapon/swapoff, so are protected | |
236 | * by swap_lock. changing flags need | |
237 | * hold this lock and swap_lock. If | |
238 | * both locks need hold, hold swap_lock | |
239 | * first. | |
ec8acf20 | 240 | */ |
815c2c54 | 241 | struct work_struct discard_work; /* discard worker */ |
6b534915 | 242 | struct swap_cluster_list discard_clusters; /* discard clusters list */ |
1da177e4 LT |
243 | }; |
244 | ||
a528910e JW |
245 | /* linux/mm/workingset.c */ |
246 | void *workingset_eviction(struct address_space *mapping, struct page *page); | |
247 | bool workingset_refault(void *shadow); | |
248 | void workingset_activation(struct page *page); | |
449dd698 JW |
249 | extern struct list_lru workingset_shadow_nodes; |
250 | ||
251 | static inline unsigned int workingset_node_pages(struct radix_tree_node *node) | |
252 | { | |
253 | return node->count & RADIX_TREE_COUNT_MASK; | |
254 | } | |
255 | ||
256 | static inline void workingset_node_pages_inc(struct radix_tree_node *node) | |
257 | { | |
258 | node->count++; | |
259 | } | |
260 | ||
261 | static inline void workingset_node_pages_dec(struct radix_tree_node *node) | |
262 | { | |
21f54dda | 263 | VM_WARN_ON_ONCE(!workingset_node_pages(node)); |
449dd698 JW |
264 | node->count--; |
265 | } | |
266 | ||
267 | static inline unsigned int workingset_node_shadows(struct radix_tree_node *node) | |
268 | { | |
269 | return node->count >> RADIX_TREE_COUNT_SHIFT; | |
270 | } | |
271 | ||
272 | static inline void workingset_node_shadows_inc(struct radix_tree_node *node) | |
273 | { | |
274 | node->count += 1U << RADIX_TREE_COUNT_SHIFT; | |
275 | } | |
276 | ||
277 | static inline void workingset_node_shadows_dec(struct radix_tree_node *node) | |
278 | { | |
21f54dda | 279 | VM_WARN_ON_ONCE(!workingset_node_shadows(node)); |
449dd698 JW |
280 | node->count -= 1U << RADIX_TREE_COUNT_SHIFT; |
281 | } | |
a528910e | 282 | |
1da177e4 LT |
283 | /* linux/mm/page_alloc.c */ |
284 | extern unsigned long totalram_pages; | |
cb45b0e9 | 285 | extern unsigned long totalreserve_pages; |
ebec3862 ZY |
286 | extern unsigned long nr_free_buffer_pages(void); |
287 | extern unsigned long nr_free_pagecache_pages(void); | |
1da177e4 | 288 | |
96177299 CL |
289 | /* Definition of global_page_state not available yet */ |
290 | #define nr_free_pages() global_page_state(NR_FREE_PAGES) | |
291 | ||
292 | ||
1da177e4 | 293 | /* linux/mm/swap.c */ |
c53954a0 | 294 | extern void lru_cache_add(struct page *); |
2329d375 JZ |
295 | extern void lru_cache_add_anon(struct page *page); |
296 | extern void lru_cache_add_file(struct page *page); | |
fa9add64 | 297 | extern void lru_add_page_tail(struct page *page, struct page *page_tail, |
5bc7b8ac | 298 | struct lruvec *lruvec, struct list_head *head); |
b3c97528 HH |
299 | extern void activate_page(struct page *); |
300 | extern void mark_page_accessed(struct page *); | |
1da177e4 | 301 | extern void lru_add_drain(void); |
f0cb3c76 | 302 | extern void lru_add_drain_cpu(int cpu); |
5fbc4616 | 303 | extern void lru_add_drain_all(void); |
ac6aadb2 | 304 | extern void rotate_reclaimable_page(struct page *page); |
cc5993bd | 305 | extern void deactivate_file_page(struct page *page); |
10853a03 | 306 | extern void deactivate_page(struct page *page); |
1da177e4 LT |
307 | extern void swap_setup(void); |
308 | ||
894bc310 LS |
309 | extern void add_page_to_unevictable_list(struct page *page); |
310 | ||
00501b53 JW |
311 | extern void lru_cache_add_active_or_unevictable(struct page *page, |
312 | struct vm_area_struct *vma); | |
313 | ||
1da177e4 | 314 | /* linux/mm/vmscan.c */ |
5a1c84b4 | 315 | extern unsigned long zone_reclaimable_pages(struct zone *zone); |
599d0c95 | 316 | extern unsigned long pgdat_reclaimable_pages(struct pglist_data *pgdat); |
dac1d27b | 317 | extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, |
327c0e96 | 318 | gfp_t gfp_mask, nodemask_t *mask); |
f3fd4a61 | 319 | extern int __isolate_lru_page(struct page *page, isolate_mode_t mode); |
b70a2a21 JW |
320 | extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, |
321 | unsigned long nr_pages, | |
322 | gfp_t gfp_mask, | |
323 | bool may_swap); | |
a9dd0a83 | 324 | extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem, |
185efc0f | 325 | gfp_t gfp_mask, bool noswap, |
ef8f2327 | 326 | pg_data_t *pgdat, |
185efc0f | 327 | unsigned long *nr_scanned); |
69e05944 | 328 | extern unsigned long shrink_all_memory(unsigned long nr_pages); |
1da177e4 | 329 | extern int vm_swappiness; |
b20a3503 | 330 | extern int remove_mapping(struct address_space *mapping, struct page *page); |
b21e0b90 | 331 | extern unsigned long vm_total_pages; |
b20a3503 | 332 | |
9eeff239 | 333 | #ifdef CONFIG_NUMA |
a5f5f91d | 334 | extern int node_reclaim_mode; |
9614634f | 335 | extern int sysctl_min_unmapped_ratio; |
0ff38490 | 336 | extern int sysctl_min_slab_ratio; |
a5f5f91d | 337 | extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int); |
9eeff239 | 338 | #else |
a5f5f91d MG |
339 | #define node_reclaim_mode 0 |
340 | static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask, | |
341 | unsigned int order) | |
9eeff239 CL |
342 | { |
343 | return 0; | |
344 | } | |
345 | #endif | |
346 | ||
39b5f29a | 347 | extern int page_evictable(struct page *page); |
24513264 | 348 | extern void check_move_unevictable_pages(struct page **, int nr_pages); |
af936a16 | 349 | |
3218ae14 | 350 | extern int kswapd_run(int nid); |
8fe23e05 | 351 | extern void kswapd_stop(int nid); |
33398cf2 | 352 | |
1da177e4 LT |
353 | #ifdef CONFIG_SWAP |
354 | /* linux/mm/page_io.c */ | |
aca8bf32 | 355 | extern int swap_readpage(struct page *); |
1da177e4 | 356 | extern int swap_writepage(struct page *page, struct writeback_control *wbc); |
4246a0b6 | 357 | extern void end_swap_bio_write(struct bio *bio); |
1eec6702 | 358 | extern int __swap_writepage(struct page *page, struct writeback_control *wbc, |
4246a0b6 | 359 | bio_end_io_t end_write_func); |
62c230bc | 360 | extern int swap_set_page_dirty(struct page *page); |
1da177e4 | 361 | |
a509bc1a MG |
362 | int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page, |
363 | unsigned long nr_pages, sector_t start_block); | |
364 | int generic_swapfile_activate(struct swap_info_struct *, struct file *, | |
365 | sector_t *); | |
366 | ||
1da177e4 | 367 | /* linux/mm/swap_state.c */ |
33806f06 SL |
368 | extern struct address_space swapper_spaces[]; |
369 | #define swap_address_space(entry) (&swapper_spaces[swp_type(entry)]) | |
370 | extern unsigned long total_swapcache_pages(void); | |
1da177e4 | 371 | extern void show_swap_cache_info(void); |
5bc7b8ac | 372 | extern int add_to_swap(struct page *, struct list_head *list); |
73b1262f | 373 | extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t); |
2f772e6c | 374 | extern int __add_to_swap_cache(struct page *page, swp_entry_t entry); |
1da177e4 LT |
375 | extern void __delete_from_swap_cache(struct page *); |
376 | extern void delete_from_swap_cache(struct page *); | |
1da177e4 LT |
377 | extern void free_page_and_swap_cache(struct page *); |
378 | extern void free_pages_and_swap_cache(struct page **, int); | |
46017e95 | 379 | extern struct page *lookup_swap_cache(swp_entry_t); |
02098fea | 380 | extern struct page *read_swap_cache_async(swp_entry_t, gfp_t, |
46017e95 | 381 | struct vm_area_struct *vma, unsigned long addr); |
5b999aad DS |
382 | extern struct page *__read_swap_cache_async(swp_entry_t, gfp_t, |
383 | struct vm_area_struct *vma, unsigned long addr, | |
384 | bool *new_page_allocated); | |
02098fea | 385 | extern struct page *swapin_readahead(swp_entry_t, gfp_t, |
46017e95 HD |
386 | struct vm_area_struct *vma, unsigned long addr); |
387 | ||
1da177e4 | 388 | /* linux/mm/swapfile.c */ |
ec8acf20 | 389 | extern atomic_long_t nr_swap_pages; |
1da177e4 | 390 | extern long total_swap_pages; |
ec8acf20 SL |
391 | |
392 | /* Swap 50% full? Release swapcache more aggressively.. */ | |
393 | static inline bool vm_swap_full(void) | |
394 | { | |
395 | return atomic_long_read(&nr_swap_pages) * 2 < total_swap_pages; | |
396 | } | |
397 | ||
398 | static inline long get_nr_swap_pages(void) | |
399 | { | |
400 | return atomic_long_read(&nr_swap_pages); | |
401 | } | |
402 | ||
1da177e4 LT |
403 | extern void si_swapinfo(struct sysinfo *); |
404 | extern swp_entry_t get_swap_page(void); | |
910321ea | 405 | extern swp_entry_t get_swap_page_of_type(int); |
570a335b | 406 | extern int add_swap_count_continuation(swp_entry_t, gfp_t); |
aaa46865 | 407 | extern void swap_shmem_alloc(swp_entry_t); |
570a335b HD |
408 | extern int swap_duplicate(swp_entry_t); |
409 | extern int swapcache_prepare(swp_entry_t); | |
1da177e4 | 410 | extern void swap_free(swp_entry_t); |
0a31bc97 | 411 | extern void swapcache_free(swp_entry_t); |
2509ef26 | 412 | extern int free_swap_and_cache(swp_entry_t); |
7bf23687 | 413 | extern int swap_type_of(dev_t, sector_t, struct block_device **); |
f577eb30 | 414 | extern unsigned int count_swap_pages(int, int); |
d4906e1a | 415 | extern sector_t map_swap_page(struct page *, struct block_device **); |
3aef83e0 | 416 | extern sector_t swapdev_block(int, pgoff_t); |
bde05d1c | 417 | extern int page_swapcount(struct page *); |
8334b962 | 418 | extern int swp_swapcount(swp_entry_t entry); |
f981c595 | 419 | extern struct swap_info_struct *page_swap_info(struct page *); |
6d0a07ed | 420 | extern bool reuse_swap_page(struct page *, int *); |
a2c43eed | 421 | extern int try_to_free_swap(struct page *); |
1da177e4 LT |
422 | struct backing_dev_info; |
423 | ||
1da177e4 LT |
424 | #else /* CONFIG_SWAP */ |
425 | ||
d2cf5ad6 | 426 | #define swap_address_space(entry) (NULL) |
ec8acf20 | 427 | #define get_nr_swap_pages() 0L |
b962716b | 428 | #define total_swap_pages 0L |
33806f06 | 429 | #define total_swapcache_pages() 0UL |
ec8acf20 | 430 | #define vm_swap_full() 0 |
1da177e4 LT |
431 | |
432 | #define si_swapinfo(val) \ | |
433 | do { (val)->freeswap = (val)->totalswap = 0; } while (0) | |
9ae5b3c7 | 434 | /* only sparc can not include linux/pagemap.h in this file |
ea1754a0 | 435 | * so leave put_page and release_pages undeclared... */ |
1da177e4 | 436 | #define free_page_and_swap_cache(page) \ |
09cbfeaf | 437 | put_page(page) |
1da177e4 | 438 | #define free_pages_and_swap_cache(pages, nr) \ |
b745bc85 | 439 | release_pages((pages), (nr), false); |
1da177e4 | 440 | |
bd96b9eb CK |
441 | static inline void show_swap_cache_info(void) |
442 | { | |
443 | } | |
444 | ||
2509ef26 | 445 | #define free_swap_and_cache(swp) is_migration_entry(swp) |
cb4b86ba | 446 | #define swapcache_prepare(swp) is_migration_entry(swp) |
bd96b9eb | 447 | |
570a335b | 448 | static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask) |
355cfa73 | 449 | { |
570a335b HD |
450 | return 0; |
451 | } | |
452 | ||
aaa46865 HD |
453 | static inline void swap_shmem_alloc(swp_entry_t swp) |
454 | { | |
455 | } | |
456 | ||
570a335b HD |
457 | static inline int swap_duplicate(swp_entry_t swp) |
458 | { | |
459 | return 0; | |
355cfa73 KH |
460 | } |
461 | ||
bd96b9eb CK |
462 | static inline void swap_free(swp_entry_t swp) |
463 | { | |
464 | } | |
465 | ||
0a31bc97 | 466 | static inline void swapcache_free(swp_entry_t swp) |
cb4b86ba KH |
467 | { |
468 | } | |
469 | ||
02098fea | 470 | static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask, |
bd96b9eb CK |
471 | struct vm_area_struct *vma, unsigned long addr) |
472 | { | |
473 | return NULL; | |
474 | } | |
475 | ||
9fab5619 HD |
476 | static inline int swap_writepage(struct page *p, struct writeback_control *wbc) |
477 | { | |
478 | return 0; | |
479 | } | |
480 | ||
bd96b9eb CK |
481 | static inline struct page *lookup_swap_cache(swp_entry_t swp) |
482 | { | |
483 | return NULL; | |
484 | } | |
485 | ||
5bc7b8ac | 486 | static inline int add_to_swap(struct page *page, struct list_head *list) |
60371d97 HD |
487 | { |
488 | return 0; | |
489 | } | |
490 | ||
73b1262f HD |
491 | static inline int add_to_swap_cache(struct page *page, swp_entry_t entry, |
492 | gfp_t gfp_mask) | |
bd96b9eb | 493 | { |
73b1262f | 494 | return -1; |
bd96b9eb CK |
495 | } |
496 | ||
497 | static inline void __delete_from_swap_cache(struct page *page) | |
498 | { | |
499 | } | |
500 | ||
501 | static inline void delete_from_swap_cache(struct page *page) | |
502 | { | |
503 | } | |
504 | ||
bde05d1c HD |
505 | static inline int page_swapcount(struct page *page) |
506 | { | |
507 | return 0; | |
508 | } | |
509 | ||
8334b962 MK |
510 | static inline int swp_swapcount(swp_entry_t entry) |
511 | { | |
512 | return 0; | |
513 | } | |
514 | ||
6d0a07ed AA |
515 | #define reuse_swap_page(page, total_mapcount) \ |
516 | (page_trans_huge_mapcount(page, total_mapcount) == 1) | |
1da177e4 | 517 | |
a2c43eed | 518 | static inline int try_to_free_swap(struct page *page) |
68a22394 RR |
519 | { |
520 | return 0; | |
521 | } | |
522 | ||
1da177e4 LT |
523 | static inline swp_entry_t get_swap_page(void) |
524 | { | |
525 | swp_entry_t entry; | |
526 | entry.val = 0; | |
527 | return entry; | |
528 | } | |
529 | ||
1da177e4 | 530 | #endif /* CONFIG_SWAP */ |
6f2cb2f1 VD |
531 | |
532 | #ifdef CONFIG_MEMCG | |
533 | static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg) | |
534 | { | |
4550c4e1 JW |
535 | /* Cgroup2 doesn't have per-cgroup swappiness */ |
536 | if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) | |
537 | return vm_swappiness; | |
538 | ||
6f2cb2f1 VD |
539 | /* root ? */ |
540 | if (mem_cgroup_disabled() || !memcg->css.parent) | |
541 | return vm_swappiness; | |
542 | ||
543 | return memcg->swappiness; | |
544 | } | |
545 | ||
546 | #else | |
547 | static inline int mem_cgroup_swappiness(struct mem_cgroup *mem) | |
548 | { | |
549 | return vm_swappiness; | |
550 | } | |
551 | #endif | |
552 | ||
553 | #ifdef CONFIG_MEMCG_SWAP | |
554 | extern void mem_cgroup_swapout(struct page *page, swp_entry_t entry); | |
555 | extern int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry); | |
556 | extern void mem_cgroup_uncharge_swap(swp_entry_t entry); | |
d8b38438 | 557 | extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg); |
5ccc5aba | 558 | extern bool mem_cgroup_swap_full(struct page *page); |
6f2cb2f1 VD |
559 | #else |
560 | static inline void mem_cgroup_swapout(struct page *page, swp_entry_t entry) | |
561 | { | |
562 | } | |
563 | ||
564 | static inline int mem_cgroup_try_charge_swap(struct page *page, | |
565 | swp_entry_t entry) | |
566 | { | |
567 | return 0; | |
568 | } | |
569 | ||
570 | static inline void mem_cgroup_uncharge_swap(swp_entry_t entry) | |
571 | { | |
572 | } | |
d8b38438 VD |
573 | |
574 | static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg) | |
575 | { | |
576 | return get_nr_swap_pages(); | |
577 | } | |
5ccc5aba VD |
578 | |
579 | static inline bool mem_cgroup_swap_full(struct page *page) | |
580 | { | |
581 | return vm_swap_full(); | |
582 | } | |
6f2cb2f1 VD |
583 | #endif |
584 | ||
1da177e4 LT |
585 | #endif /* __KERNEL__*/ |
586 | #endif /* _LINUX_SWAP_H */ |