1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SWAP_H
3 #define _LINUX_SWAP_H
4
5 #include <linux/spinlock.h>
6 #include <linux/linkage.h>
7 #include <linux/mmzone.h>
8 #include <linux/list.h>
9 #include <linux/memcontrol.h>
10 #include <linux/sched.h>
11 #include <linux/node.h>
12 #include <linux/fs.h>
13 #include <linux/pagemap.h>
14 #include <linux/atomic.h>
15 #include <linux/page-flags.h>
16 #include <uapi/linux/mempolicy.h>
17 #include <asm/page.h>
18
19 struct notifier_block;
20
21 struct bio;
22
23 #define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */
24 #define SWAP_FLAG_PRIO_MASK 0x7fff
25 #define SWAP_FLAG_DISCARD 0x10000 /* enable discard for swap */
26 #define SWAP_FLAG_DISCARD_ONCE 0x20000 /* discard swap area at swapon-time */
27 #define SWAP_FLAG_DISCARD_PAGES 0x40000 /* discard page-clusters after use */
28
29 #define SWAP_FLAGS_VALID (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \
30 SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | \
31 SWAP_FLAG_DISCARD_PAGES)
32 #define SWAP_BATCH 64
33
current_is_kswapd(void)34 static inline int current_is_kswapd(void)
35 {
36 return current->flags & PF_KSWAPD;
37 }
38
39 /*
40 * MAX_SWAPFILES defines the maximum number of swaptypes: things which can
41 * be swapped to. The swap type and the offset into that swap type are
42 * encoded into pte's and into pgoff_t's in the swapcache. Using five bits
43 * for the type means that the maximum number of swapcache pages is 27 bits
44 * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs
45 * the type/offset into the pte as 5/27 as well.
46 */
47 #define MAX_SWAPFILES_SHIFT 5
48
49 /*
50 * Use some of the swap files numbers for other purposes. This
51 * is a convenient way to hook into the VM to trigger special
52 * actions on faults.
53 */
54
55 /*
56 * PTE markers are used to persist information onto PTEs that otherwise
57 * should be a none pte. As its name "PTE" hints, it should only be
58 * applied to the leaves of pgtables.
59 */
60 #define SWP_PTE_MARKER_NUM 1
61 #define SWP_PTE_MARKER (MAX_SWAPFILES + SWP_HWPOISON_NUM + \
62 SWP_MIGRATION_NUM + SWP_DEVICE_NUM)
63
64 /*
65 * Unaddressable device memory support. See include/linux/hmm.h and
66 * Documentation/mm/hmm.rst. Short description is we need struct pages for
67 * device memory that is unaddressable (inaccessible) by CPU, so that we can
68 * migrate part of a process memory to device memory.
69 *
70 * When a page is migrated from CPU to device, we set the CPU page table entry
71 * to a special SWP_DEVICE_{READ|WRITE} entry.
72 *
73 * When a page is mapped by the device for exclusive access we set the CPU page
74 * table entries to a special SWP_DEVICE_EXCLUSIVE entry.
75 */
76 #ifdef CONFIG_DEVICE_PRIVATE
77 #define SWP_DEVICE_NUM 3
78 #define SWP_DEVICE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM)
79 #define SWP_DEVICE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+1)
80 #define SWP_DEVICE_EXCLUSIVE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+2)
81 #else
82 #define SWP_DEVICE_NUM 0
83 #endif
84
85 /*
86 * Page migration support.
87 *
88 * SWP_MIGRATION_READ_EXCLUSIVE is only applicable to anonymous pages and
89 * indicates that the referenced (part of) an anonymous page is exclusive to
90 * a single process. For SWP_MIGRATION_WRITE, that information is implicit:
91 * (part of) an anonymous page that are mapped writable are exclusive to a
92 * single process.
93 */
94 #ifdef CONFIG_MIGRATION
95 #define SWP_MIGRATION_NUM 3
96 #define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM)
97 #define SWP_MIGRATION_READ_EXCLUSIVE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1)
98 #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 2)
99 #else
100 #define SWP_MIGRATION_NUM 0
101 #endif
102
103 /*
104 * Handling of hardware poisoned pages with memory corruption.
105 */
106 #ifdef CONFIG_MEMORY_FAILURE
107 #define SWP_HWPOISON_NUM 1
108 #define SWP_HWPOISON MAX_SWAPFILES
109 #else
110 #define SWP_HWPOISON_NUM 0
111 #endif
112
113 #define MAX_SWAPFILES \
114 ((1 << MAX_SWAPFILES_SHIFT) - SWP_DEVICE_NUM - \
115 SWP_MIGRATION_NUM - SWP_HWPOISON_NUM - \
116 SWP_PTE_MARKER_NUM)
117
118 /*
119 * Magic header for a swap area. The first part of the union is
120 * what the swap magic looks like for the old (limited to 128MB)
121 * swap area format, the second part of the union adds - in the
122 * old reserved area - some extra information. Note that the first
123 * kilobyte is reserved for boot loader or disk label stuff...
124 *
125 * Having the magic at the end of the PAGE_SIZE makes detecting swap
126 * areas somewhat tricky on machines that support multiple page sizes.
127 * For 2.5 we'll probably want to move the magic to just beyond the
128 * bootbits...
129 */
130 union swap_header {
131 struct {
132 char reserved[PAGE_SIZE - 10];
133 char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */
134 } magic;
135 struct {
136 char bootbits[1024]; /* Space for disklabel etc. */
137 __u32 version;
138 __u32 last_page;
139 __u32 nr_badpages;
140 unsigned char sws_uuid[16];
141 unsigned char sws_volume[16];
142 __u32 padding[117];
143 __u32 badpages[1];
144 } info;
145 };
146
147 /*
148 * current->reclaim_state points to one of these when a task is running
149 * memory reclaim
150 */
151 struct reclaim_state {
152 /* pages reclaimed outside of LRU-based reclaim */
153 unsigned long reclaimed;
154 #ifdef CONFIG_LRU_GEN
155 /* per-thread mm walk data */
156 struct lru_gen_mm_walk *mm_walk;
157 #endif
158 };
159
160 /*
161 * mm_account_reclaimed_pages(): account reclaimed pages outside of LRU-based
162 * reclaim
163 * @pages: number of pages reclaimed
164 *
165 * If the current process is undergoing a reclaim operation, increment the
166 * number of reclaimed pages by @pages.
167 */
mm_account_reclaimed_pages(unsigned long pages)168 static inline void mm_account_reclaimed_pages(unsigned long pages)
169 {
170 if (current->reclaim_state)
171 current->reclaim_state->reclaimed += pages;
172 }
173
174 #ifdef __KERNEL__
175
176 struct address_space;
177 struct sysinfo;
178 struct writeback_control;
179 struct zone;
180
181 /*
182 * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of
183 * disk blocks. A rbtree of swap extents maps the entire swapfile (Where the
184 * term `swapfile' refers to either a blockdevice or an IS_REG file). Apart
185 * from setup, they're handled identically.
186 *
187 * We always assume that blocks are of size PAGE_SIZE.
188 */
189 struct swap_extent {
190 struct rb_node rb_node;
191 pgoff_t start_page;
192 pgoff_t nr_pages;
193 sector_t start_block;
194 };
195
196 /*
197 * Max bad pages in the new format..
198 */
199 #define MAX_SWAP_BADPAGES \
200 ((offsetof(union swap_header, magic.magic) - \
201 offsetof(union swap_header, info.badpages)) / sizeof(int))
202
203 enum {
204 SWP_USED = (1 << 0), /* is slot in swap_info[] used? */
205 SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */
206 SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */
207 SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */
208 SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */
209 SWP_BLKDEV = (1 << 6), /* its a block device */
210 SWP_ACTIVATED = (1 << 7), /* set after swap_activate success */
211 SWP_FS_OPS = (1 << 8), /* swapfile operations go through fs */
212 SWP_AREA_DISCARD = (1 << 9), /* single-time swap area discards */
213 SWP_PAGE_DISCARD = (1 << 10), /* freed swap page-cluster discards */
214 SWP_STABLE_WRITES = (1 << 11), /* no overwrite PG_writeback pages */
215 SWP_SYNCHRONOUS_IO = (1 << 12), /* synchronous IO is efficient */
216 /* add others here before... */
217 };
218
219 #define SWAP_CLUSTER_MAX 32UL
220 #define SWAP_CLUSTER_MAX_SKIPPED (SWAP_CLUSTER_MAX << 10)
221 #define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX
222
223 /*
224 * The first page in the swap file is the swap header, which is always marked
225 * bad to prevent it from being allocated as an entry. This also prevents the
226 * cluster to which it belongs being marked free. Therefore 0 is safe to use as
227 * a sentinel to indicate an entry is not valid.
228 */
229 #define SWAP_ENTRY_INVALID 0
230
231 #ifdef CONFIG_THP_SWAP
232 #define SWAP_NR_ORDERS (PMD_ORDER + 1)
233 #else
234 #define SWAP_NR_ORDERS 1
235 #endif
236
237 /*
238 * We keep using same cluster for rotational device so IO will be sequential.
239 * The purpose is to optimize SWAP throughput on these device.
240 */
241 struct swap_sequential_cluster {
242 unsigned int next[SWAP_NR_ORDERS]; /* Likely next allocation offset */
243 };
244
245 /*
246 * The in-memory structure used to track swap areas.
247 */
248 struct swap_info_struct {
249 struct percpu_ref users; /* indicate and keep swap device valid. */
250 unsigned long flags; /* SWP_USED etc: see above */
251 signed short prio; /* swap priority of this type */
252 struct plist_node list; /* entry in swap_active_head */
253 signed char type; /* strange name for an index */
254 unsigned int max; /* size of this swap device */
255 unsigned long *zeromap; /* kvmalloc'ed bitmap to track zero pages */
256 struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */
257 struct list_head free_clusters; /* free clusters list */
258 struct list_head full_clusters; /* full clusters list */
259 struct list_head nonfull_clusters[SWAP_NR_ORDERS];
260 /* list of cluster that contains at least one free slot */
261 struct list_head frag_clusters[SWAP_NR_ORDERS];
262 /* list of cluster that are fragmented or contented */
263 unsigned int pages; /* total of usable pages of swap */
264 atomic_long_t inuse_pages; /* number of those currently in use */
265 struct swap_sequential_cluster *global_cluster; /* Use one global cluster for rotating device */
266 spinlock_t global_cluster_lock; /* Serialize usage of global cluster */
267 struct rb_root swap_extent_root;/* root of the swap extent rbtree */
268 struct block_device *bdev; /* swap device or bdev of swap file */
269 struct file *swap_file; /* seldom referenced */
270 struct completion comp; /* seldom referenced */
271 spinlock_t lock; /*
272 * protect map scan related fields like
273 * inuse_pages and all cluster lists.
274 * Other fields are only changed
275 * at swapon/swapoff, so are protected
276 * by swap_lock. changing flags need
277 * hold this lock and swap_lock. If
278 * both locks need hold, hold swap_lock
279 * first.
280 */
281 struct work_struct discard_work; /* discard worker */
282 struct work_struct reclaim_work; /* reclaim worker */
283 struct list_head discard_clusters; /* discard clusters list */
284 struct plist_node avail_list; /* entry in swap_avail_head */
285 };
286
page_swap_entry(struct page * page)287 static inline swp_entry_t page_swap_entry(struct page *page)
288 {
289 struct folio *folio = page_folio(page);
290 swp_entry_t entry = folio->swap;
291
292 entry.val += folio_page_idx(folio, page);
293 return entry;
294 }
295
296 /* linux/mm/workingset.c */
297 bool workingset_test_recent(void *shadow, bool file, bool *workingset,
298 bool flush);
299 void workingset_age_nonresident(struct lruvec *lruvec, unsigned long nr_pages);
300 void *workingset_eviction(struct folio *folio, struct mem_cgroup *target_memcg);
301 void workingset_refault(struct folio *folio, void *shadow);
302 void workingset_activation(struct folio *folio);
303
304 /* linux/mm/page_alloc.c */
305 extern unsigned long totalreserve_pages;
306
307 /* Definition of global_zone_page_state not available yet */
308 #define nr_free_pages() global_zone_page_state(NR_FREE_PAGES)
309
310
311 /* linux/mm/swap.c */
312 void lru_note_cost_unlock_irq(struct lruvec *lruvec, bool file,
313 unsigned int nr_io, unsigned int nr_rotated)
314 __releases(lruvec->lru_lock);
315 void lru_note_cost_refault(struct folio *);
316 void folio_add_lru(struct folio *);
317 void folio_add_lru_vma(struct folio *, struct vm_area_struct *);
318 void mark_page_accessed(struct page *);
319 void folio_mark_accessed(struct folio *);
320
folio_may_be_lru_cached(struct folio * folio)321 static inline bool folio_may_be_lru_cached(struct folio *folio)
322 {
323 /*
324 * Holding PMD-sized folios in per-CPU LRU cache unbalances accounting.
325 * Holding small numbers of low-order mTHP folios in per-CPU LRU cache
326 * will be sensible, but nobody has implemented and tested that yet.
327 */
328 return !folio_test_large(folio);
329 }
330
331 extern atomic_t lru_disable_count;
332
lru_cache_disabled(void)333 static inline bool lru_cache_disabled(void)
334 {
335 return atomic_read(&lru_disable_count);
336 }
337
lru_cache_enable(void)338 static inline void lru_cache_enable(void)
339 {
340 atomic_dec(&lru_disable_count);
341 }
342
343 extern void lru_cache_disable(void);
344 extern void lru_add_drain(void);
345 extern void lru_add_drain_cpu(int cpu);
346 extern void lru_add_drain_cpu_zone(struct zone *zone);
347 extern void lru_add_drain_all(void);
348 void folio_deactivate(struct folio *folio);
349 void folio_mark_lazyfree(struct folio *folio);
350 extern void swap_setup(void);
351
352 /* linux/mm/vmscan.c */
353 extern unsigned long zone_reclaimable_pages(struct zone *zone);
354 extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
355 gfp_t gfp_mask, nodemask_t *mask);
356
357 #define MEMCG_RECLAIM_MAY_SWAP (1 << 1)
358 #define MEMCG_RECLAIM_PROACTIVE (1 << 2)
359 #define MIN_SWAPPINESS 0
360 #define MAX_SWAPPINESS 200
361
362 /* Just reclaim from anon folios in proactive memory reclaim */
363 #define SWAPPINESS_ANON_ONLY (MAX_SWAPPINESS + 1)
364
365 extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
366 unsigned long nr_pages,
367 gfp_t gfp_mask,
368 unsigned int reclaim_options,
369 int *swappiness);
370 extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem,
371 gfp_t gfp_mask, bool noswap,
372 pg_data_t *pgdat,
373 unsigned long *nr_scanned);
374 extern unsigned long shrink_all_memory(unsigned long nr_pages);
375 extern int vm_swappiness;
376 long remove_mapping(struct address_space *mapping, struct folio *folio);
377
378 #if defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
379 extern int reclaim_register_node(struct node *node);
380 extern void reclaim_unregister_node(struct node *node);
381
382 #else
383
reclaim_register_node(struct node * node)384 static inline int reclaim_register_node(struct node *node)
385 {
386 return 0;
387 }
388
reclaim_unregister_node(struct node * node)389 static inline void reclaim_unregister_node(struct node *node)
390 {
391 }
392 #endif /* CONFIG_SYSFS && CONFIG_NUMA */
393
394 #ifdef CONFIG_NUMA
395 extern int sysctl_min_unmapped_ratio;
396 extern int sysctl_min_slab_ratio;
397 #endif
398
399 void check_move_unevictable_folios(struct folio_batch *fbatch);
400
401 extern void __meminit kswapd_run(int nid);
402 extern void __meminit kswapd_stop(int nid);
403
404 #ifdef CONFIG_SWAP
405
406 int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page,
407 unsigned long nr_pages, sector_t start_block);
408 int generic_swapfile_activate(struct swap_info_struct *, struct file *,
409 sector_t *);
410
total_swapcache_pages(void)411 static inline unsigned long total_swapcache_pages(void)
412 {
413 return global_node_page_state(NR_SWAPCACHE);
414 }
415
416 void free_swap_cache(struct folio *folio);
417 void free_folio_and_swap_cache(struct folio *folio);
418 void free_pages_and_swap_cache(struct encoded_page **, int);
419 /* linux/mm/swapfile.c */
420 extern atomic_long_t nr_swap_pages;
421 extern long total_swap_pages;
422 extern atomic_t nr_rotate_swap;
423
424 /* Swap 50% full? Release swapcache more aggressively.. */
vm_swap_full(void)425 static inline bool vm_swap_full(void)
426 {
427 return atomic_long_read(&nr_swap_pages) * 2 < total_swap_pages;
428 }
429
get_nr_swap_pages(void)430 static inline long get_nr_swap_pages(void)
431 {
432 return atomic_long_read(&nr_swap_pages);
433 }
434
435 extern void si_swapinfo(struct sysinfo *);
436 int swap_type_of(dev_t device, sector_t offset);
437 int find_first_swap(dev_t *device);
438 extern unsigned int count_swap_pages(int, int);
439 extern sector_t swapdev_block(int, pgoff_t);
440 extern int __swap_count(swp_entry_t entry);
441 extern bool swap_entry_swapped(struct swap_info_struct *si, swp_entry_t entry);
442 extern int swp_swapcount(swp_entry_t entry);
443 struct backing_dev_info;
444 extern struct swap_info_struct *get_swap_device(swp_entry_t entry);
445 sector_t swap_folio_sector(struct folio *folio);
446
447 /*
448 * If there is an existing swap slot reference (swap entry) and the caller
449 * guarantees that there is no race modification of it (e.g., PTL
450 * protecting the swap entry in page table; shmem's cmpxchg protects t
451 * he swap entry in shmem mapping), these two helpers below can be used
452 * to put/dup the entries directly.
453 *
454 * All entries must be allocated by folio_alloc_swap(). And they must have
455 * a swap count > 1. See comments of folio_*_swap helpers for more info.
456 */
457 int swap_dup_entry_direct(swp_entry_t entry);
458 void swap_put_entries_direct(swp_entry_t entry, int nr);
459
460 /*
461 * folio_free_swap tries to free the swap entries pinned by a swap cache
462 * folio, it has to be here to be called by other components.
463 */
464 bool folio_free_swap(struct folio *folio);
465
466 /* Allocate / free (hibernation) exclusive entries */
467 swp_entry_t swap_alloc_hibernation_slot(int type);
468 void swap_free_hibernation_slot(swp_entry_t entry);
469
put_swap_device(struct swap_info_struct * si)470 static inline void put_swap_device(struct swap_info_struct *si)
471 {
472 percpu_ref_put(&si->users);
473 }
474
475 #else /* CONFIG_SWAP */
get_swap_device(swp_entry_t entry)476 static inline struct swap_info_struct *get_swap_device(swp_entry_t entry)
477 {
478 return NULL;
479 }
480
put_swap_device(struct swap_info_struct * si)481 static inline void put_swap_device(struct swap_info_struct *si)
482 {
483 }
484
485 #define get_nr_swap_pages() 0L
486 #define total_swap_pages 0L
487 #define total_swapcache_pages() 0UL
488 #define vm_swap_full() 0
489
490 #define si_swapinfo(val) \
491 do { (val)->freeswap = (val)->totalswap = 0; } while (0)
492 #define free_folio_and_swap_cache(folio) \
493 folio_put(folio)
494 #define free_pages_and_swap_cache(pages, nr) \
495 release_pages((pages), (nr));
496
free_swap_cache(struct folio * folio)497 static inline void free_swap_cache(struct folio *folio)
498 {
499 }
500
swap_dup_entry_direct(swp_entry_t ent)501 static inline int swap_dup_entry_direct(swp_entry_t ent)
502 {
503 return 0;
504 }
505
swap_put_entries_direct(swp_entry_t ent,int nr)506 static inline void swap_put_entries_direct(swp_entry_t ent, int nr)
507 {
508 }
509
__swap_count(swp_entry_t entry)510 static inline int __swap_count(swp_entry_t entry)
511 {
512 return 0;
513 }
514
swap_entry_swapped(struct swap_info_struct * si,swp_entry_t entry)515 static inline bool swap_entry_swapped(struct swap_info_struct *si, swp_entry_t entry)
516 {
517 return false;
518 }
519
swp_swapcount(swp_entry_t entry)520 static inline int swp_swapcount(swp_entry_t entry)
521 {
522 return 0;
523 }
524
folio_free_swap(struct folio * folio)525 static inline bool folio_free_swap(struct folio *folio)
526 {
527 return false;
528 }
529
add_swap_extent(struct swap_info_struct * sis,unsigned long start_page,unsigned long nr_pages,sector_t start_block)530 static inline int add_swap_extent(struct swap_info_struct *sis,
531 unsigned long start_page,
532 unsigned long nr_pages, sector_t start_block)
533 {
534 return -EINVAL;
535 }
536 #endif /* CONFIG_SWAP */
537 #ifdef CONFIG_MEMCG
mem_cgroup_swappiness(struct mem_cgroup * memcg)538 static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg)
539 {
540 /* Cgroup2 doesn't have per-cgroup swappiness */
541 if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
542 return READ_ONCE(vm_swappiness);
543
544 /* root ? */
545 if (mem_cgroup_disabled() || mem_cgroup_is_root(memcg))
546 return READ_ONCE(vm_swappiness);
547
548 return READ_ONCE(memcg->swappiness);
549 }
550 #else
mem_cgroup_swappiness(struct mem_cgroup * mem)551 static inline int mem_cgroup_swappiness(struct mem_cgroup *mem)
552 {
553 return READ_ONCE(vm_swappiness);
554 }
555 #endif
556
557 #if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
558 void __folio_throttle_swaprate(struct folio *folio, gfp_t gfp);
folio_throttle_swaprate(struct folio * folio,gfp_t gfp)559 static inline void folio_throttle_swaprate(struct folio *folio, gfp_t gfp)
560 {
561 if (mem_cgroup_disabled())
562 return;
563 __folio_throttle_swaprate(folio, gfp);
564 }
565 #else
folio_throttle_swaprate(struct folio * folio,gfp_t gfp)566 static inline void folio_throttle_swaprate(struct folio *folio, gfp_t gfp)
567 {
568 }
569 #endif
570
571 #if defined(CONFIG_MEMCG) && defined(CONFIG_SWAP)
572 int __mem_cgroup_try_charge_swap(struct folio *folio, swp_entry_t entry);
mem_cgroup_try_charge_swap(struct folio * folio,swp_entry_t entry)573 static inline int mem_cgroup_try_charge_swap(struct folio *folio,
574 swp_entry_t entry)
575 {
576 if (mem_cgroup_disabled())
577 return 0;
578 return __mem_cgroup_try_charge_swap(folio, entry);
579 }
580
581 extern void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages);
mem_cgroup_uncharge_swap(swp_entry_t entry,unsigned int nr_pages)582 static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages)
583 {
584 if (mem_cgroup_disabled())
585 return;
586 __mem_cgroup_uncharge_swap(entry, nr_pages);
587 }
588
589 extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg);
590 extern bool mem_cgroup_swap_full(struct folio *folio);
591 #else
mem_cgroup_try_charge_swap(struct folio * folio,swp_entry_t entry)592 static inline int mem_cgroup_try_charge_swap(struct folio *folio,
593 swp_entry_t entry)
594 {
595 return 0;
596 }
597
mem_cgroup_uncharge_swap(swp_entry_t entry,unsigned int nr_pages)598 static inline void mem_cgroup_uncharge_swap(swp_entry_t entry,
599 unsigned int nr_pages)
600 {
601 }
602
mem_cgroup_get_nr_swap_pages(struct mem_cgroup * memcg)603 static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
604 {
605 return get_nr_swap_pages();
606 }
607
mem_cgroup_swap_full(struct folio * folio)608 static inline bool mem_cgroup_swap_full(struct folio *folio)
609 {
610 return vm_swap_full();
611 }
612 #endif
613
614 #endif /* __KERNEL__*/
615 #endif /* _LINUX_SWAP_H */
616