Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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/atomic.h>
14#include <linux/page-flags.h>
15#include <asm/page.h>
16
17struct notifier_block;
18
19struct bio;
20
21#define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */
22#define SWAP_FLAG_PRIO_MASK 0x7fff
23#define SWAP_FLAG_PRIO_SHIFT 0
24#define SWAP_FLAG_DISCARD 0x10000 /* enable discard for swap */
25#define SWAP_FLAG_DISCARD_ONCE 0x20000 /* discard swap area at swapon-time */
26#define SWAP_FLAG_DISCARD_PAGES 0x40000 /* discard page-clusters after use */
27
28#define SWAP_FLAGS_VALID (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \
29 SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | \
30 SWAP_FLAG_DISCARD_PAGES)
31#define SWAP_BATCH 64
32
33static inline int current_is_kswapd(void)
34{
35 return current->flags & PF_KSWAPD;
36}
37
38/*
39 * MAX_SWAPFILES defines the maximum number of swaptypes: things which can
40 * be swapped to. The swap type and the offset into that swap type are
41 * encoded into pte's and into pgoff_t's in the swapcache. Using five bits
42 * for the type means that the maximum number of swapcache pages is 27 bits
43 * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs
44 * the type/offset into the pte as 5/27 as well.
45 */
46#define MAX_SWAPFILES_SHIFT 5
47
48/*
49 * Use some of the swap files numbers for other purposes. This
50 * is a convenient way to hook into the VM to trigger special
51 * actions on faults.
52 */
53
54/*
55 * Unaddressable device memory support. See include/linux/hmm.h and
56 * Documentation/vm/hmm.txt. Short description is we need struct pages for
57 * device memory that is unaddressable (inaccessible) by CPU, so that we can
58 * migrate part of a process memory to device memory.
59 *
60 * When a page is migrated from CPU to device, we set the CPU page table entry
61 * to a special SWP_DEVICE_* entry.
62 */
63#ifdef CONFIG_DEVICE_PRIVATE
64#define SWP_DEVICE_NUM 2
65#define SWP_DEVICE_WRITE (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM)
66#define SWP_DEVICE_READ (MAX_SWAPFILES+SWP_HWPOISON_NUM+SWP_MIGRATION_NUM+1)
67#else
68#define SWP_DEVICE_NUM 0
69#endif
70
71/*
72 * NUMA node memory migration support
73 */
74#ifdef CONFIG_MIGRATION
75#define SWP_MIGRATION_NUM 2
76#define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM)
77#define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1)
78#else
79#define SWP_MIGRATION_NUM 0
80#endif
81
82/*
83 * Handling of hardware poisoned pages with memory corruption.
84 */
85#ifdef CONFIG_MEMORY_FAILURE
86#define SWP_HWPOISON_NUM 1
87#define SWP_HWPOISON MAX_SWAPFILES
88#else
89#define SWP_HWPOISON_NUM 0
90#endif
91
92#define MAX_SWAPFILES \
93 ((1 << MAX_SWAPFILES_SHIFT) - SWP_DEVICE_NUM - \
94 SWP_MIGRATION_NUM - SWP_HWPOISON_NUM)
95
96/*
97 * Magic header for a swap area. The first part of the union is
98 * what the swap magic looks like for the old (limited to 128MB)
99 * swap area format, the second part of the union adds - in the
100 * old reserved area - some extra information. Note that the first
101 * kilobyte is reserved for boot loader or disk label stuff...
102 *
103 * Having the magic at the end of the PAGE_SIZE makes detecting swap
104 * areas somewhat tricky on machines that support multiple page sizes.
105 * For 2.5 we'll probably want to move the magic to just beyond the
106 * bootbits...
107 */
108union swap_header {
109 struct {
110 char reserved[PAGE_SIZE - 10];
111 char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */
112 } magic;
113 struct {
114 char bootbits[1024]; /* Space for disklabel etc. */
115 __u32 version;
116 __u32 last_page;
117 __u32 nr_badpages;
118 unsigned char sws_uuid[16];
119 unsigned char sws_volume[16];
120 __u32 padding[117];
121 __u32 badpages[1];
122 } info;
123};
124
125/*
126 * current->reclaim_state points to one of these when a task is running
127 * memory reclaim
128 */
129struct reclaim_state {
130 unsigned long reclaimed_slab;
131};
132
133#ifdef __KERNEL__
134
135struct address_space;
136struct sysinfo;
137struct writeback_control;
138struct zone;
139
140/*
141 * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of
142 * disk blocks. A list of swap extents maps the entire swapfile. (Where the
143 * term `swapfile' refers to either a blockdevice or an IS_REG file. Apart
144 * from setup, they're handled identically.
145 *
146 * We always assume that blocks are of size PAGE_SIZE.
147 */
148struct swap_extent {
149 struct list_head list;
150 pgoff_t start_page;
151 pgoff_t nr_pages;
152 sector_t start_block;
153};
154
155/*
156 * Max bad pages in the new format..
157 */
158#define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x)
159#define MAX_SWAP_BADPAGES \
160 ((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int))
161
162enum {
163 SWP_USED = (1 << 0), /* is slot in swap_info[] used? */
164 SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */
165 SWP_DISCARDABLE = (1 << 2), /* blkdev support discard */
166 SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */
167 SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */
168 SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */
169 SWP_BLKDEV = (1 << 6), /* its a block device */
170 SWP_FILE = (1 << 7), /* set after swap_activate success */
171 SWP_AREA_DISCARD = (1 << 8), /* single-time swap area discards */
172 SWP_PAGE_DISCARD = (1 << 9), /* freed swap page-cluster discards */
173 SWP_STABLE_WRITES = (1 << 10), /* no overwrite PG_writeback pages */
174 /* add others here before... */
175 SWP_SCANNING = (1 << 11), /* refcount in scan_swap_map */
176};
177
178#define SWAP_CLUSTER_MAX 32UL
179#define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX
180
181#define SWAP_MAP_MAX 0x3e /* Max duplication count, in first swap_map */
182#define SWAP_MAP_BAD 0x3f /* Note pageblock is bad, in first swap_map */
183#define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */
184#define SWAP_CONT_MAX 0x7f /* Max count, in each swap_map continuation */
185#define COUNT_CONTINUED 0x80 /* See swap_map continuation for full count */
186#define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs, in first swap_map */
187
188/*
189 * We use this to track usage of a cluster. A cluster is a block of swap disk
190 * space with SWAPFILE_CLUSTER pages long and naturally aligns in disk. All
191 * free clusters are organized into a list. We fetch an entry from the list to
192 * get a free cluster.
193 *
194 * The data field stores next cluster if the cluster is free or cluster usage
195 * counter otherwise. The flags field determines if a cluster is free. This is
196 * protected by swap_info_struct.lock.
197 */
198struct swap_cluster_info {
199 spinlock_t lock; /*
200 * Protect swap_cluster_info fields
201 * and swap_info_struct->swap_map
202 * elements correspond to the swap
203 * cluster
204 */
205 unsigned int data:24;
206 unsigned int flags:8;
207};
208#define CLUSTER_FLAG_FREE 1 /* This cluster is free */
209#define CLUSTER_FLAG_NEXT_NULL 2 /* This cluster has no next cluster */
210#define CLUSTER_FLAG_HUGE 4 /* This cluster is backing a transparent huge page */
211
212/*
213 * We assign a cluster to each CPU, so each CPU can allocate swap entry from
214 * its own cluster and swapout sequentially. The purpose is to optimize swapout
215 * throughput.
216 */
217struct percpu_cluster {
218 struct swap_cluster_info index; /* Current cluster index */
219 unsigned int next; /* Likely next allocation offset */
220};
221
222struct swap_cluster_list {
223 struct swap_cluster_info head;
224 struct swap_cluster_info tail;
225};
226
227/*
228 * The in-memory structure used to track swap areas.
229 */
230struct swap_info_struct {
231 unsigned long flags; /* SWP_USED etc: see above */
232 signed short prio; /* swap priority of this type */
233 struct plist_node list; /* entry in swap_active_head */
234 struct plist_node avail_lists[MAX_NUMNODES];/* entry in swap_avail_heads */
235 signed char type; /* strange name for an index */
236 unsigned int max; /* extent of the swap_map */
237 unsigned char *swap_map; /* vmalloc'ed array of usage counts */
238 struct swap_cluster_info *cluster_info; /* cluster info. Only for SSD */
239 struct swap_cluster_list free_clusters; /* free clusters list */
240 unsigned int lowest_bit; /* index of first free in swap_map */
241 unsigned int highest_bit; /* index of last free in swap_map */
242 unsigned int pages; /* total of usable pages of swap */
243 unsigned int inuse_pages; /* number of those currently in use */
244 unsigned int cluster_next; /* likely index for next allocation */
245 unsigned int cluster_nr; /* countdown to next cluster search */
246 struct percpu_cluster __percpu *percpu_cluster; /* per cpu's swap location */
247 struct swap_extent *curr_swap_extent;
248 struct swap_extent first_swap_extent;
249 struct block_device *bdev; /* swap device or bdev of swap file */
250 struct file *swap_file; /* seldom referenced */
251 unsigned int old_block_size; /* seldom referenced */
252#ifdef CONFIG_FRONTSWAP
253 unsigned long *frontswap_map; /* frontswap in-use, one bit per page */
254 atomic_t frontswap_pages; /* frontswap pages in-use counter */
255#endif
256 spinlock_t lock; /*
257 * protect map scan related fields like
258 * swap_map, lowest_bit, highest_bit,
259 * inuse_pages, cluster_next,
260 * cluster_nr, lowest_alloc,
261 * highest_alloc, free/discard cluster
262 * list. other fields are only changed
263 * at swapon/swapoff, so are protected
264 * by swap_lock. changing flags need
265 * hold this lock and swap_lock. If
266 * both locks need hold, hold swap_lock
267 * first.
268 */
269 spinlock_t cont_lock; /*
270 * protect swap count continuation page
271 * list.
272 */
273 struct work_struct discard_work; /* discard worker */
274 struct swap_cluster_list discard_clusters; /* discard clusters list */
275};
276
277#ifdef CONFIG_64BIT
278#define SWAP_RA_ORDER_CEILING 5
279#else
280/* Avoid stack overflow, because we need to save part of page table */
281#define SWAP_RA_ORDER_CEILING 3
282#define SWAP_RA_PTE_CACHE_SIZE (1 << SWAP_RA_ORDER_CEILING)
283#endif
284
285struct vma_swap_readahead {
286 unsigned short win;
287 unsigned short offset;
288 unsigned short nr_pte;
289#ifdef CONFIG_64BIT
290 pte_t *ptes;
291#else
292 pte_t ptes[SWAP_RA_PTE_CACHE_SIZE];
293#endif
294};
295
296/* linux/mm/workingset.c */
297void *workingset_eviction(struct address_space *mapping, struct page *page);
298bool workingset_refault(void *shadow);
299void workingset_activation(struct page *page);
300void workingset_update_node(struct radix_tree_node *node, void *private);
301
302/* linux/mm/page_alloc.c */
303extern unsigned long totalram_pages;
304extern unsigned long totalreserve_pages;
305extern unsigned long nr_free_buffer_pages(void);
306extern unsigned long nr_free_pagecache_pages(void);
307
308/* Definition of global_zone_page_state not available yet */
309#define nr_free_pages() global_zone_page_state(NR_FREE_PAGES)
310
311
312/* linux/mm/swap.c */
313extern void lru_cache_add(struct page *);
314extern void lru_cache_add_anon(struct page *page);
315extern void lru_cache_add_file(struct page *page);
316extern void lru_add_page_tail(struct page *page, struct page *page_tail,
317 struct lruvec *lruvec, struct list_head *head);
318extern void activate_page(struct page *);
319extern void mark_page_accessed(struct page *);
320extern void lru_add_drain(void);
321extern void lru_add_drain_cpu(int cpu);
322extern void lru_add_drain_all(void);
323extern void lru_add_drain_all_cpuslocked(void);
324extern void rotate_reclaimable_page(struct page *page);
325extern void deactivate_file_page(struct page *page);
326extern void mark_page_lazyfree(struct page *page);
327extern void swap_setup(void);
328
329extern void add_page_to_unevictable_list(struct page *page);
330
331extern void lru_cache_add_active_or_unevictable(struct page *page,
332 struct vm_area_struct *vma);
333
334/* linux/mm/vmscan.c */
335extern unsigned long zone_reclaimable_pages(struct zone *zone);
336extern unsigned long pgdat_reclaimable_pages(struct pglist_data *pgdat);
337extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
338 gfp_t gfp_mask, nodemask_t *mask);
339extern int __isolate_lru_page(struct page *page, isolate_mode_t mode);
340extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg,
341 unsigned long nr_pages,
342 gfp_t gfp_mask,
343 bool may_swap);
344extern unsigned long mem_cgroup_shrink_node(struct mem_cgroup *mem,
345 gfp_t gfp_mask, bool noswap,
346 pg_data_t *pgdat,
347 unsigned long *nr_scanned);
348extern unsigned long shrink_all_memory(unsigned long nr_pages);
349extern int vm_swappiness;
350extern int remove_mapping(struct address_space *mapping, struct page *page);
351extern unsigned long vm_total_pages;
352
353#ifdef CONFIG_NUMA
354extern int node_reclaim_mode;
355extern int sysctl_min_unmapped_ratio;
356extern int sysctl_min_slab_ratio;
357extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
358#else
359#define node_reclaim_mode 0
360static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
361 unsigned int order)
362{
363 return 0;
364}
365#endif
366
367extern int page_evictable(struct page *page);
368extern void check_move_unevictable_pages(struct page **, int nr_pages);
369
370extern int kswapd_run(int nid);
371extern void kswapd_stop(int nid);
372
373#ifdef CONFIG_SWAP
374
375#include <linux/blk_types.h> /* for bio_end_io_t */
376
377/* linux/mm/page_io.c */
378extern int swap_readpage(struct page *page, bool do_poll);
379extern int swap_writepage(struct page *page, struct writeback_control *wbc);
380extern void end_swap_bio_write(struct bio *bio);
381extern int __swap_writepage(struct page *page, struct writeback_control *wbc,
382 bio_end_io_t end_write_func);
383extern int swap_set_page_dirty(struct page *page);
384
385int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page,
386 unsigned long nr_pages, sector_t start_block);
387int generic_swapfile_activate(struct swap_info_struct *, struct file *,
388 sector_t *);
389
390/* linux/mm/swap_state.c */
391/* One swap address space for each 64M swap space */
392#define SWAP_ADDRESS_SPACE_SHIFT 14
393#define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT)
394extern struct address_space *swapper_spaces[];
395extern bool swap_vma_readahead;
396#define swap_address_space(entry) \
397 (&swapper_spaces[swp_type(entry)][swp_offset(entry) \
398 >> SWAP_ADDRESS_SPACE_SHIFT])
399extern unsigned long total_swapcache_pages(void);
400extern void show_swap_cache_info(void);
401extern int add_to_swap(struct page *page);
402extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t);
403extern int __add_to_swap_cache(struct page *page, swp_entry_t entry);
404extern void __delete_from_swap_cache(struct page *);
405extern void delete_from_swap_cache(struct page *);
406extern void free_page_and_swap_cache(struct page *);
407extern void free_pages_and_swap_cache(struct page **, int);
408extern struct page *lookup_swap_cache(swp_entry_t entry,
409 struct vm_area_struct *vma,
410 unsigned long addr);
411extern struct page *read_swap_cache_async(swp_entry_t, gfp_t,
412 struct vm_area_struct *vma, unsigned long addr,
413 bool do_poll);
414extern struct page *__read_swap_cache_async(swp_entry_t, gfp_t,
415 struct vm_area_struct *vma, unsigned long addr,
416 bool *new_page_allocated);
417extern struct page *swapin_readahead(swp_entry_t, gfp_t,
418 struct vm_area_struct *vma, unsigned long addr);
419
420extern struct page *swap_readahead_detect(struct vm_fault *vmf,
421 struct vma_swap_readahead *swap_ra);
422extern struct page *do_swap_page_readahead(swp_entry_t fentry, gfp_t gfp_mask,
423 struct vm_fault *vmf,
424 struct vma_swap_readahead *swap_ra);
425
426/* linux/mm/swapfile.c */
427extern atomic_long_t nr_swap_pages;
428extern long total_swap_pages;
429extern atomic_t nr_rotate_swap;
430extern bool has_usable_swap(void);
431
432static inline bool swap_use_vma_readahead(void)
433{
434 return READ_ONCE(swap_vma_readahead) && !atomic_read(&nr_rotate_swap);
435}
436
437/* Swap 50% full? Release swapcache more aggressively.. */
438static inline bool vm_swap_full(void)
439{
440 return atomic_long_read(&nr_swap_pages) * 2 < total_swap_pages;
441}
442
443static inline long get_nr_swap_pages(void)
444{
445 return atomic_long_read(&nr_swap_pages);
446}
447
448extern void si_swapinfo(struct sysinfo *);
449extern swp_entry_t get_swap_page(struct page *page);
450extern void put_swap_page(struct page *page, swp_entry_t entry);
451extern swp_entry_t get_swap_page_of_type(int);
452extern int get_swap_pages(int n, bool cluster, swp_entry_t swp_entries[]);
453extern int add_swap_count_continuation(swp_entry_t, gfp_t);
454extern void swap_shmem_alloc(swp_entry_t);
455extern int swap_duplicate(swp_entry_t);
456extern int swapcache_prepare(swp_entry_t);
457extern void swap_free(swp_entry_t);
458extern void swapcache_free_entries(swp_entry_t *entries, int n);
459extern int free_swap_and_cache(swp_entry_t);
460extern int swap_type_of(dev_t, sector_t, struct block_device **);
461extern unsigned int count_swap_pages(int, int);
462extern sector_t map_swap_page(struct page *, struct block_device **);
463extern sector_t swapdev_block(int, pgoff_t);
464extern int page_swapcount(struct page *);
465extern int __swp_swapcount(swp_entry_t entry);
466extern int swp_swapcount(swp_entry_t entry);
467extern struct swap_info_struct *page_swap_info(struct page *);
468extern bool reuse_swap_page(struct page *, int *);
469extern int try_to_free_swap(struct page *);
470struct backing_dev_info;
471extern int init_swap_address_space(unsigned int type, unsigned long nr_pages);
472extern void exit_swap_address_space(unsigned int type);
473
474#else /* CONFIG_SWAP */
475
476#define swap_address_space(entry) (NULL)
477#define get_nr_swap_pages() 0L
478#define total_swap_pages 0L
479#define total_swapcache_pages() 0UL
480#define vm_swap_full() 0
481
482#define si_swapinfo(val) \
483 do { (val)->freeswap = (val)->totalswap = 0; } while (0)
484/* only sparc can not include linux/pagemap.h in this file
485 * so leave put_page and release_pages undeclared... */
486#define free_page_and_swap_cache(page) \
487 put_page(page)
488#define free_pages_and_swap_cache(pages, nr) \
489 release_pages((pages), (nr), false);
490
491static inline void show_swap_cache_info(void)
492{
493}
494
495#define free_swap_and_cache(e) ({(is_migration_entry(e) || is_device_private_entry(e));})
496#define swapcache_prepare(e) ({(is_migration_entry(e) || is_device_private_entry(e));})
497
498static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask)
499{
500 return 0;
501}
502
503static inline void swap_shmem_alloc(swp_entry_t swp)
504{
505}
506
507static inline int swap_duplicate(swp_entry_t swp)
508{
509 return 0;
510}
511
512static inline void swap_free(swp_entry_t swp)
513{
514}
515
516static inline void put_swap_page(struct page *page, swp_entry_t swp)
517{
518}
519
520static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
521 struct vm_area_struct *vma, unsigned long addr)
522{
523 return NULL;
524}
525
526static inline bool swap_use_vma_readahead(void)
527{
528 return false;
529}
530
531static inline struct page *swap_readahead_detect(
532 struct vm_fault *vmf, struct vma_swap_readahead *swap_ra)
533{
534 return NULL;
535}
536
537static inline struct page *do_swap_page_readahead(
538 swp_entry_t fentry, gfp_t gfp_mask,
539 struct vm_fault *vmf, struct vma_swap_readahead *swap_ra)
540{
541 return NULL;
542}
543
544static inline int swap_writepage(struct page *p, struct writeback_control *wbc)
545{
546 return 0;
547}
548
549static inline struct page *lookup_swap_cache(swp_entry_t swp,
550 struct vm_area_struct *vma,
551 unsigned long addr)
552{
553 return NULL;
554}
555
556static inline int add_to_swap(struct page *page)
557{
558 return 0;
559}
560
561static inline int add_to_swap_cache(struct page *page, swp_entry_t entry,
562 gfp_t gfp_mask)
563{
564 return -1;
565}
566
567static inline void __delete_from_swap_cache(struct page *page)
568{
569}
570
571static inline void delete_from_swap_cache(struct page *page)
572{
573}
574
575static inline int page_swapcount(struct page *page)
576{
577 return 0;
578}
579
580static inline int __swp_swapcount(swp_entry_t entry)
581{
582 return 0;
583}
584
585static inline int swp_swapcount(swp_entry_t entry)
586{
587 return 0;
588}
589
590#define reuse_swap_page(page, total_map_swapcount) \
591 (page_trans_huge_mapcount(page, total_map_swapcount) == 1)
592
593static inline int try_to_free_swap(struct page *page)
594{
595 return 0;
596}
597
598static inline swp_entry_t get_swap_page(struct page *page)
599{
600 swp_entry_t entry;
601 entry.val = 0;
602 return entry;
603}
604
605#endif /* CONFIG_SWAP */
606
607#ifdef CONFIG_THP_SWAP
608extern int split_swap_cluster(swp_entry_t entry);
609#else
610static inline int split_swap_cluster(swp_entry_t entry)
611{
612 return 0;
613}
614#endif
615
616#ifdef CONFIG_MEMCG
617static inline int mem_cgroup_swappiness(struct mem_cgroup *memcg)
618{
619 /* Cgroup2 doesn't have per-cgroup swappiness */
620 if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
621 return vm_swappiness;
622
623 /* root ? */
624 if (mem_cgroup_disabled() || !memcg->css.parent)
625 return vm_swappiness;
626
627 return memcg->swappiness;
628}
629
630#else
631static inline int mem_cgroup_swappiness(struct mem_cgroup *mem)
632{
633 return vm_swappiness;
634}
635#endif
636
637#ifdef CONFIG_MEMCG_SWAP
638extern void mem_cgroup_swapout(struct page *page, swp_entry_t entry);
639extern int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry);
640extern void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages);
641extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg);
642extern bool mem_cgroup_swap_full(struct page *page);
643#else
644static inline void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
645{
646}
647
648static inline int mem_cgroup_try_charge_swap(struct page *page,
649 swp_entry_t entry)
650{
651 return 0;
652}
653
654static inline void mem_cgroup_uncharge_swap(swp_entry_t entry,
655 unsigned int nr_pages)
656{
657}
658
659static inline long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
660{
661 return get_nr_swap_pages();
662}
663
664static inline bool mem_cgroup_swap_full(struct page *page)
665{
666 return vm_swap_full();
667}
668#endif
669
670#endif /* __KERNEL__*/
671#endif /* _LINUX_SWAP_H */