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 struct pagevec;
24
25 #define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */
26 #define SWAP_FLAG_PRIO_MASK 0x7fff
27 #define SWAP_FLAG_DISCARD 0x10000 /* enable discard for swap */
28 #define SWAP_FLAG_DISCARD_ONCE 0x20000 /* discard swap area at swapon-time */
29 #define SWAP_FLAG_DISCARD_PAGES 0x40000 /* discard page-clusters after use */
30
31 #define SWAP_FLAGS_VALID (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \
32 SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | \
33 SWAP_FLAG_DISCARD_PAGES)
34 #define SWAP_BATCH 64
35
current_is_kswapd(void)36 static inline int current_is_kswapd(void)
37 {
38 return current->flags & PF_KSWAPD;
39 }
40
41 /*
42 * MAX_SWAPFILES defines the maximum number of swaptypes: things which can
43 * be swapped to. The swap type and the offset into that swap type are
44 * encoded into pte's and into pgoff_t's in the swapcache. Using five bits
45 * for the type means that the maximum number of swapcache pages is 27 bits
46 * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs
47 * the type/offset into the pte as 5/27 as well.
48 */
49 #define MAX_SWAPFILES_SHIFT 5
50
51 /*
52 * Use some of the swap files numbers for other purposes. This
53 * is a convenient way to hook into the VM to trigger special
54 * actions on faults.
55 */
56
57 /*
58 * PTE markers are used to persist information onto PTEs that otherwise
59 * should be a none pte. As its name "PTE" hints, it should only be
60 * applied to the leaves of pgtables.
61 */
62 #define SWP_PTE_MARKER_NUM 1
63 #define SWP_PTE_MARKER (MAX_SWAPFILES + SWP_HWPOISON_NUM + \
64 SWP_MIGRATION_NUM + SWP_DEVICE_NUM)
65
66 /*
67 * Unaddressable device memory support. See include/linux/hmm.h and
68 * Documentation/mm/hmm.rst. Short description is we need struct pages for
69 * device memory that is unaddressable (inaccessible) by CPU, so that we can
70 * migrate part of a process memory to device memory.
71 *
72 * When a page is migrated from CPU to device, we set the CPU page table entry
73 * to a special SWP_DEVICE_{READ|WRITE} entry.
74 *
75 * When a page is mapped by the device for exclusive access we set the CPU page
76 * table entries to a special SWP_DEVICE_EXCLUSIVE entry.
77 */
78 #ifdef CONFIG_DEVICE_PRIVATE
79 #define SWP_DEVICE_NUM 3
80 #define SWP_DEVICE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM)
81 #define SWP_DEVICE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+1)
82 #define SWP_DEVICE_EXCLUSIVE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+2)
83 #else
84 #define SWP_DEVICE_NUM 0
85 #endif
86
87 /*
88 * Page migration support.
89 *
90 * SWP_MIGRATION_READ_EXCLUSIVE is only applicable to anonymous pages and
91 * indicates that the referenced (part of) an anonymous page is exclusive to
92 * a single process. For SWP_MIGRATION_WRITE, that information is implicit:
93 * (part of) an anonymous page that are mapped writable are exclusive to a
94 * single process.
95 */
96 #ifdef CONFIG_MIGRATION
97 #define SWP_MIGRATION_NUM 3
98 #define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM)
99 #define SWP_MIGRATION_READ_EXCLUSIVE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1)
100 #define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 2)
101 #else
102 #define SWP_MIGRATION_NUM 0
103 #endif
104
105 /*
106 * Handling of hardware poisoned pages with memory corruption.
107 */
108 #ifdef CONFIG_MEMORY_FAILURE
109 #define SWP_HWPOISON_NUM 1
110 #define SWP_HWPOISON MAX_SWAPFILES
111 #else
112 #define SWP_HWPOISON_NUM 0
113 #endif
114
115 #define MAX_SWAPFILES \
116 ((1 << MAX_SWAPFILES_SHIFT) - SWP_DEVICE_NUM - \
117 SWP_MIGRATION_NUM - SWP_HWPOISON_NUM - \
118 SWP_PTE_MARKER_NUM)
119
120 /*
121 * Magic header for a swap area. The first part of the union is
122 * what the swap magic looks like for the old (limited to 128MB)
123 * swap area format, the second part of the union adds - in the
124 * old reserved area - some extra information. Note that the first
125 * kilobyte is reserved for boot loader or disk label stuff...
126 *
127 * Having the magic at the end of the PAGE_SIZE makes detecting swap
128 * areas somewhat tricky on machines that support multiple page sizes.
129 * For 2.5 we'll probably want to move the magic to just beyond the
130 * bootbits...
131 */
132 union swap_header {
133 struct {
134 char reserved[PAGE_SIZE - 10];
135 char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */
136 } magic;
137 struct {
138 char bootbits[1024]; /* Space for disklabel etc. */
139 __u32 version;
140 __u32 last_page;
141 __u32 nr_badpages;
142 unsigned char sws_uuid[16];
143 unsigned char sws_volume[16];
144 __u32 padding[117];
145 __u32 badpages[1];
146 } info;
147 };
148
149 /*
150 * current->reclaim_state points to one of these when a task is running
151 * memory reclaim
152 */
153 struct reclaim_state {
154 /* pages reclaimed outside of LRU-based reclaim */
155 unsigned long reclaimed;
156 #ifdef CONFIG_LRU_GEN
157 /* per-thread mm walk data */
158 struct lru_gen_mm_walk *mm_walk;
159 #endif
160 };
161
162 /*
163 * mm_account_reclaimed_pages(): account reclaimed pages outside of LRU-based
164 * reclaim
165 * @pages: number of pages reclaimed
166 *
167 * If the current process is undergoing a reclaim operation, increment the
168 * number of reclaimed pages by @pages.
169 */
mm_account_reclaimed_pages(unsigned long pages)170 static inline void mm_account_reclaimed_pages(unsigned long pages)
171 {
172 if (current->reclaim_state)
173 current->reclaim_state->reclaimed += pages;
174 }
175
176 #ifdef __KERNEL__
177
178 struct address_space;
179 struct sysinfo;
180 struct writeback_control;
181 struct zone;
182
183 /*
184 * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of
185 * disk blocks. A rbtree of swap extents maps the entire swapfile (Where the
186 * term `swapfile' refers to either a blockdevice or an IS_REG file). Apart
187 * from setup, they're handled identically.
188 *
189 * We always assume that blocks are of size PAGE_SIZE.
190 */
191 struct swap_extent {
192 struct rb_node rb_node;
193 pgoff_t start_page;
194 pgoff_t nr_pages;
195 sector_t start_block;
196 };
197
198 /*
199 * Max bad pages in the new format..
200 */
201 #define MAX_SWAP_BADPAGES \
202 ((offsetof(union swap_header, magic.magic) - \
203 offsetof(union swap_header, info.badpages)) / sizeof(int))
204
205 enum {
206 SWP_USED = (1 << 0), /* is slot in swap_info[] used? */
207 SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */
208 SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */
209 SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */
210 SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */
211 SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */
212 SWP_BLKDEV = (1 << 6), /* its a block device */
213 SWP_ACTIVATED = (1 << 7), /* set after swap_activate success */
214 SWP_FS_OPS = (1 << 8), /* swapfile operations go through fs */
215 SWP_AREA_DISCARD = (1 << 9), /* single-time swap area discards */
216 SWP_PAGE_DISCARD = (1 << 10), /* freed swap page-cluster discards */
217 SWP_STABLE_WRITES = (1 << 11), /* no overwrite PG_writeback pages */
218 SWP_SYNCHRONOUS_IO = (1 << 12), /* synchronous IO is efficient */
219 /* add others here before... */
220 };
221
222 #define SWAP_CLUSTER_MAX 32UL
223 #define SWAP_CLUSTER_MAX_SKIPPED (SWAP_CLUSTER_MAX << 10)
224 #define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX
225
226 /* Bit flag in swap_map */
227 #define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */
228 #define COUNT_CONTINUED 0x80 /* Flag swap_map continuation for full count */
229
230 /* Special value in first swap_map */
231 #define SWAP_MAP_MAX 0x3e /* Max count */
232 #define SWAP_MAP_BAD 0x3f /* Note page is bad */
233 #define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs */
234
235 /* Special value in each swap_map continuation */
236 #define SWAP_CONT_MAX 0x7f /* Max count */
237
238 /*
239 * The first page in the swap file is the swap header, which is always marked
240 * bad to prevent it from being allocated as an entry. This also prevents the
241 * cluster to which it belongs being marked free. Therefore 0 is safe to use as
242 * a sentinel to indicate an entry is not valid.
243 */
244 #define SWAP_ENTRY_INVALID 0
245
246 #ifdef CONFIG_THP_SWAP
247 #define SWAP_NR_ORDERS (PMD_ORDER + 1)
248 #else
249 #define SWAP_NR_ORDERS 1
250 #endif
251
252 /*
253 * We keep using same cluster for rotational device so IO will be sequential.
254 * The purpose is to optimize SWAP throughput on these device.
255 */
256 struct swap_sequential_cluster {
257 unsigned int next[SWAP_NR_ORDERS]; /* Likely next allocation offset */
258 };
259
260 /*
261 * The in-memory structure used to track swap areas.
262 */
263 struct swap_info_struct {
264 struct percpu_ref users; /* indicate and keep swap device valid. */
265 unsigned long flags; /* SWP_USED etc: see above */
266 signed short prio; /* swap priority of this type */
267 struct plist_node list; /* entry in swap_active_head */
268 signed char type; /* strange name for an index */
269 unsigned int max; /* extent of the swap_map */
270 unsigned char *swap_map; /* vmalloc'ed array of usage counts */
271 unsigned long *zeromap; /* kvmalloc'ed bitmap to track zero pages */
272 struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */
273 struct list_head free_clusters; /* free clusters list */
274 struct list_head full_clusters; /* full clusters list */
275 struct list_head nonfull_clusters[SWAP_NR_ORDERS];
276 /* list of cluster that contains at least one free slot */
277 struct list_head frag_clusters[SWAP_NR_ORDERS];
278 /* list of cluster that are fragmented or contented */
279 unsigned int pages; /* total of usable pages of swap */
280 atomic_long_t inuse_pages; /* number of those currently in use */
281 struct swap_sequential_cluster *global_cluster; /* Use one global cluster for rotating device */
282 spinlock_t global_cluster_lock; /* Serialize usage of global cluster */
283 struct rb_root swap_extent_root;/* root of the swap extent rbtree */
284 struct block_device *bdev; /* swap device or bdev of swap file */
285 struct file *swap_file; /* seldom referenced */
286 struct completion comp; /* seldom referenced */
287 spinlock_t lock; /*
288 * protect map scan related fields like
289 * swap_map, inuse_pages and all cluster
290 * lists. other fields are only changed
291 * at swapon/swapoff, so are protected
292 * by swap_lock. changing flags need
293 * hold this lock and swap_lock. If
294 * both locks need hold, hold swap_lock
295 * first.
296 */
297 spinlock_t cont_lock; /*
298 * protect swap count continuation page
299 * list.
300 */
301 struct work_struct discard_work; /* discard worker */
302 struct work_struct reclaim_work; /* reclaim worker */
303 struct list_head discard_clusters; /* discard clusters list */
304 struct plist_node avail_list; /* entry in swap_avail_head */
305 };
306
page_swap_entry(struct page * page)307 static inline swp_entry_t page_swap_entry(struct page *page)
308 {
309 struct folio *folio = page_folio(page);
310 swp_entry_t entry = folio->swap;
311
312 entry.val += folio_page_idx(folio, page);
313 return entry;
314 }
315
316 /* linux/mm/workingset.c */
317 bool workingset_test_recent(void *shadow, bool file, bool *workingset,
318 bool flush);
319 void workingset_age_nonresident(struct lruvec *lruvec, unsigned long nr_pages);
320 void *workingset_eviction(struct folio *folio, struct mem_cgroup *target_memcg);
321 void workingset_refault(struct folio *folio, void *shadow);
322 void workingset_activation(struct folio *folio);
323
324 /* linux/mm/page_alloc.c */
325 extern unsigned long totalreserve_pages;
326
327 /* Definition of global_zone_page_state not available yet */
328 #define nr_free_pages() global_zone_page_state(NR_FREE_PAGES)
329
330
331 /* linux/mm/swap.c */
332 void lru_note_cost_unlock_irq(struct lruvec *lruvec, bool file,
333 unsigned int nr_io, unsigned int nr_rotated)
334 __releases(lruvec->lru_lock);
335 void lru_note_cost_refault(struct folio *);
336 void folio_add_lru(struct folio *);
337 void folio_add_lru_vma(struct folio *, struct vm_area_struct *);
338 void mark_page_accessed(struct page *);
339 void folio_mark_accessed(struct folio *);
340
folio_may_be_lru_cached(struct folio * folio)341 static inline bool folio_may_be_lru_cached(struct folio *folio)
342 {
343 /*
344 * Holding PMD-sized folios in per-CPU LRU cache unbalances accounting.
345 * Holding small numbers of low-order mTHP folios in per-CPU LRU cache
346 * will be sensible, but nobody has implemented and tested that yet.
347 */
348 return !folio_test_large(folio);
349 }
350
351 extern atomic_t lru_disable_count;
352
lru_cache_disabled(void)353 static inline bool lru_cache_disabled(void)
354 {
355 return atomic_read(&lru_disable_count);
356 }
357
lru_cache_enable(void)358 static inline void lru_cache_enable(void)
359 {
360 atomic_dec(&lru_disable_count);
361 }
362
363 extern void lru_cache_disable(void);
364 extern void lru_add_drain(void);
365 extern void lru_add_drain_cpu(int cpu);
366 extern void lru_add_drain_cpu_zone(struct zone *zone);
367 extern void lru_add_drain_all(void);
368 void folio_deactivate(struct folio *folio);
369 void folio_mark_lazyfree(struct folio *folio);
370 extern void swap_setup(void);
371
372 /* linux/mm/vmscan.c */
373 extern unsigned long zone_reclaimable_pages(struct zone *zone);
374 extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
375 gfp_t gfp_mask, nodemask_t *mask);
376
377 #define MEMCG_RECLAIM_MAY_SWAP (1 << 1)
378 #define MEMCG_RECLAIM_PROACTIVE (1 << 2)
379 #define MIN_SWAPPINESS 0
380 #define MAX_SWAPPINESS 200
381
382 /* Just reclaim from anon folios in proactive memory reclaim */
383 #define SWAPPINESS_ANON_ONLY (MAX_SWAPPINESS + 1)
384
385 extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
386 unsigned long nr_pages,
387 gfp_t gfp_mask,
388 unsigned int reclaim_options,
389 int *swappiness);
390 extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem,
391 gfp_t gfp_mask, bool noswap,
392 pg_data_t *pgdat,
393 unsigned long *nr_scanned);
394 extern unsigned long shrink_all_memory(unsigned long nr_pages);
395 extern int vm_swappiness;
396 long remove_mapping(struct address_space *mapping, struct folio *folio);
397
398 #if defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
399 extern int reclaim_register_node(struct node *node);
400 extern void reclaim_unregister_node(struct node *node);
401
402 #else
403
reclaim_register_node(struct node * node)404 static inline int reclaim_register_node(struct node *node)
405 {
406 return 0;
407 }
408
reclaim_unregister_node(struct node * node)409 static inline void reclaim_unregister_node(struct node *node)
410 {
411 }
412 #endif /* CONFIG_SYSFS && CONFIG_NUMA */
413
414 #ifdef CONFIG_NUMA
415 extern int sysctl_min_unmapped_ratio;
416 extern int sysctl_min_slab_ratio;
417 #endif
418
419 void check_move_unevictable_folios(struct folio_batch *fbatch);
420
421 extern void __meminit kswapd_run(int nid);
422 extern void __meminit kswapd_stop(int nid);
423
424 #ifdef CONFIG_SWAP
425
426 int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page,
427 unsigned long nr_pages, sector_t start_block);
428 int generic_swapfile_activate(struct swap_info_struct *, struct file *,
429 sector_t *);
430
total_swapcache_pages(void)431 static inline unsigned long total_swapcache_pages(void)
432 {
433 return global_node_page_state(NR_SWAPCACHE);
434 }
435
436 void free_swap_cache(struct folio *folio);
437 void free_folio_and_swap_cache(struct folio *folio);
438 void free_pages_and_swap_cache(struct encoded_page **, int);
439 /* linux/mm/swapfile.c */
440 extern atomic_long_t nr_swap_pages;
441 extern long total_swap_pages;
442 extern atomic_t nr_rotate_swap;
443
444 /* Swap 50% full? Release swapcache more aggressively.. */
vm_swap_full(void)445 static inline bool vm_swap_full(void)
446 {
447 return atomic_long_read(&nr_swap_pages) * 2 < total_swap_pages;
448 }
449
get_nr_swap_pages(void)450 static inline long get_nr_swap_pages(void)
451 {
452 return atomic_long_read(&nr_swap_pages);
453 }
454
455 extern void si_swapinfo(struct sysinfo *);
456 int folio_alloc_swap(struct folio *folio);
457 bool folio_free_swap(struct folio *folio);
458 void put_swap_folio(struct folio *folio, swp_entry_t entry);
459 extern swp_entry_t get_swap_page_of_type(int);
460 extern int add_swap_count_continuation(swp_entry_t, gfp_t);
461 extern void swap_shmem_alloc(swp_entry_t, int);
462 extern int swap_duplicate(swp_entry_t);
463 extern int swapcache_prepare(swp_entry_t entry, int nr);
464 extern void swap_free_nr(swp_entry_t entry, int nr_pages);
465 extern void free_swap_and_cache_nr(swp_entry_t entry, int nr);
466 int swap_type_of(dev_t device, sector_t offset);
467 int find_first_swap(dev_t *device);
468 extern unsigned int count_swap_pages(int, int);
469 extern sector_t swapdev_block(int, pgoff_t);
470 extern int __swap_count(swp_entry_t entry);
471 extern bool swap_entry_swapped(struct swap_info_struct *si, swp_entry_t entry);
472 extern int swp_swapcount(swp_entry_t entry);
473 struct backing_dev_info;
474 extern struct swap_info_struct *get_swap_device(swp_entry_t entry);
475 sector_t swap_folio_sector(struct folio *folio);
476
put_swap_device(struct swap_info_struct * si)477 static inline void put_swap_device(struct swap_info_struct *si)
478 {
479 percpu_ref_put(&si->users);
480 }
481
482 #else /* CONFIG_SWAP */
get_swap_device(swp_entry_t entry)483 static inline struct swap_info_struct *get_swap_device(swp_entry_t entry)
484 {
485 return NULL;
486 }
487
put_swap_device(struct swap_info_struct * si)488 static inline void put_swap_device(struct swap_info_struct *si)
489 {
490 }
491
492 #define get_nr_swap_pages() 0L
493 #define total_swap_pages 0L
494 #define total_swapcache_pages() 0UL
495 #define vm_swap_full() 0
496
497 #define si_swapinfo(val) \
498 do { (val)->freeswap = (val)->totalswap = 0; } while (0)
499 #define free_folio_and_swap_cache(folio) \
500 folio_put(folio)
501 #define free_pages_and_swap_cache(pages, nr) \
502 release_pages((pages), (nr));
503
free_swap_and_cache_nr(swp_entry_t entry,int nr)504 static inline void free_swap_and_cache_nr(swp_entry_t entry, int nr)
505 {
506 }
507
free_swap_cache(struct folio * folio)508 static inline void free_swap_cache(struct folio *folio)
509 {
510 }
511
add_swap_count_continuation(swp_entry_t swp,gfp_t gfp_mask)512 static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask)
513 {
514 return 0;
515 }
516
swap_shmem_alloc(swp_entry_t swp,int nr)517 static inline void swap_shmem_alloc(swp_entry_t swp, int nr)
518 {
519 }
520
swap_duplicate(swp_entry_t swp)521 static inline int swap_duplicate(swp_entry_t swp)
522 {
523 return 0;
524 }
525
swapcache_prepare(swp_entry_t swp,int nr)526 static inline int swapcache_prepare(swp_entry_t swp, int nr)
527 {
528 return 0;
529 }
530
swap_free_nr(swp_entry_t entry,int nr_pages)531 static inline void swap_free_nr(swp_entry_t entry, int nr_pages)
532 {
533 }
534
put_swap_folio(struct folio * folio,swp_entry_t swp)535 static inline void put_swap_folio(struct folio *folio, swp_entry_t swp)
536 {
537 }
538
__swap_count(swp_entry_t entry)539 static inline int __swap_count(swp_entry_t entry)
540 {
541 return 0;
542 }
543
swap_entry_swapped(struct swap_info_struct * si,swp_entry_t entry)544 static inline bool swap_entry_swapped(struct swap_info_struct *si, swp_entry_t entry)
545 {
546 return false;
547 }
548
swp_swapcount(swp_entry_t entry)549 static inline int swp_swapcount(swp_entry_t entry)
550 {
551 return 0;
552 }
553
folio_alloc_swap(struct folio * folio)554 static inline int folio_alloc_swap(struct folio *folio)
555 {
556 return -EINVAL;
557 }
558
folio_free_swap(struct folio * folio)559 static inline bool folio_free_swap(struct folio *folio)
560 {
561 return false;
562 }
563
add_swap_extent(struct swap_info_struct * sis,unsigned long start_page,unsigned long nr_pages,sector_t start_block)564 static inline int add_swap_extent(struct swap_info_struct *sis,
565 unsigned long start_page,
566 unsigned long nr_pages, sector_t start_block)
567 {
568 return -EINVAL;
569 }
570 #endif /* CONFIG_SWAP */
571
free_swap_and_cache(swp_entry_t entry)572 static inline void free_swap_and_cache(swp_entry_t entry)
573 {
574 free_swap_and_cache_nr(entry, 1);
575 }
576
swap_free(swp_entry_t entry)577 static inline void swap_free(swp_entry_t entry)
578 {
579 swap_free_nr(entry, 1);
580 }
581
582 #ifdef CONFIG_MEMCG
mem_cgroup_swappiness(struct mem_cgroup * memcg)583 static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg)
584 {
585 /* Cgroup2 doesn't have per-cgroup swappiness */
586 if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
587 return READ_ONCE(vm_swappiness);
588
589 /* root ? */
590 if (mem_cgroup_disabled() || mem_cgroup_is_root(memcg))
591 return READ_ONCE(vm_swappiness);
592
593 return READ_ONCE(memcg->swappiness);
594 }
595 #else
mem_cgroup_swappiness(struct mem_cgroup * mem)596 static inline int mem_cgroup_swappiness(struct mem_cgroup *mem)
597 {
598 return READ_ONCE(vm_swappiness);
599 }
600 #endif
601
602 #if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
603 void __folio_throttle_swaprate(struct folio *folio, gfp_t gfp);
folio_throttle_swaprate(struct folio * folio,gfp_t gfp)604 static inline void folio_throttle_swaprate(struct folio *folio, gfp_t gfp)
605 {
606 if (mem_cgroup_disabled())
607 return;
608 __folio_throttle_swaprate(folio, gfp);
609 }
610 #else
folio_throttle_swaprate(struct folio * folio,gfp_t gfp)611 static inline void folio_throttle_swaprate(struct folio *folio, gfp_t gfp)
612 {
613 }
614 #endif
615
616 #if defined(CONFIG_MEMCG) && defined(CONFIG_SWAP)
617 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)618 static inline int mem_cgroup_try_charge_swap(struct folio *folio,
619 swp_entry_t entry)
620 {
621 if (mem_cgroup_disabled())
622 return 0;
623 return __mem_cgroup_try_charge_swap(folio, entry);
624 }
625
626 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)627 static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages)
628 {
629 if (mem_cgroup_disabled())
630 return;
631 __mem_cgroup_uncharge_swap(entry, nr_pages);
632 }
633
634 extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg);
635 extern bool mem_cgroup_swap_full(struct folio *folio);
636 #else
mem_cgroup_try_charge_swap(struct folio * folio,swp_entry_t entry)637 static inline int mem_cgroup_try_charge_swap(struct folio *folio,
638 swp_entry_t entry)
639 {
640 return 0;
641 }
642
mem_cgroup_uncharge_swap(swp_entry_t entry,unsigned int nr_pages)643 static inline void mem_cgroup_uncharge_swap(swp_entry_t entry,
644 unsigned int nr_pages)
645 {
646 }
647
mem_cgroup_get_nr_swap_pages(struct mem_cgroup * memcg)648 static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
649 {
650 return get_nr_swap_pages();
651 }
652
mem_cgroup_swap_full(struct folio * folio)653 static inline bool mem_cgroup_swap_full(struct folio *folio)
654 {
655 return vm_swap_full();
656 }
657 #endif
658
659 #endif /* __KERNEL__*/
660 #endif /* _LINUX_SWAP_H */
661