[PATCH] ZVC: Support NR_SLAB_RECLAIMABLE / NR_SLAB_UNRECLAIMABLE
[GitHub/LineageOS/android_kernel_samsung_universal7580.git] / include / linux / swap.h
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1da177e4
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1#ifndef _LINUX_SWAP_H
2#define _LINUX_SWAP_H
3
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4#include <linux/spinlock.h>
5#include <linux/linkage.h>
6#include <linux/mmzone.h>
7#include <linux/list.h>
8#include <linux/sched.h>
542d1c88 9
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10#include <asm/atomic.h>
11#include <asm/page.h>
12
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13struct notifier_block;
14
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15#define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */
16#define SWAP_FLAG_PRIO_MASK 0x7fff
17#define SWAP_FLAG_PRIO_SHIFT 0
18
19static inline int current_is_kswapd(void)
20{
21 return current->flags & PF_KSWAPD;
22}
23
24/*
25 * MAX_SWAPFILES defines the maximum number of swaptypes: things which can
26 * be swapped to. The swap type and the offset into that swap type are
27 * encoded into pte's and into pgoff_t's in the swapcache. Using five bits
28 * for the type means that the maximum number of swapcache pages is 27 bits
29 * on 32-bit-pgoff_t architectures. And that assumes that the architecture packs
30 * the type/offset into the pte as 5/27 as well.
31 */
32#define MAX_SWAPFILES_SHIFT 5
0697212a 33#ifndef CONFIG_MIGRATION
1da177e4 34#define MAX_SWAPFILES (1 << MAX_SWAPFILES_SHIFT)
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35#else
36/* Use last two entries for page migration swap entries */
37#define MAX_SWAPFILES ((1 << MAX_SWAPFILES_SHIFT)-2)
38#define SWP_MIGRATION_READ MAX_SWAPFILES
39#define SWP_MIGRATION_WRITE (MAX_SWAPFILES + 1)
40#endif
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41
42/*
43 * Magic header for a swap area. The first part of the union is
44 * what the swap magic looks like for the old (limited to 128MB)
45 * swap area format, the second part of the union adds - in the
46 * old reserved area - some extra information. Note that the first
47 * kilobyte is reserved for boot loader or disk label stuff...
48 *
49 * Having the magic at the end of the PAGE_SIZE makes detecting swap
50 * areas somewhat tricky on machines that support multiple page sizes.
51 * For 2.5 we'll probably want to move the magic to just beyond the
52 * bootbits...
53 */
54union swap_header {
55 struct {
56 char reserved[PAGE_SIZE - 10];
57 char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */
58 } magic;
59 struct {
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60 char bootbits[1024]; /* Space for disklabel etc. */
61 __u32 version;
62 __u32 last_page;
63 __u32 nr_badpages;
64 unsigned char sws_uuid[16];
65 unsigned char sws_volume[16];
66 __u32 padding[117];
67 __u32 badpages[1];
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68 } info;
69};
70
71 /* A swap entry has to fit into a "unsigned long", as
72 * the entry is hidden in the "index" field of the
73 * swapper address space.
74 */
75typedef struct {
76 unsigned long val;
77} swp_entry_t;
78
79/*
80 * current->reclaim_state points to one of these when a task is running
81 * memory reclaim
82 */
83struct reclaim_state {
84 unsigned long reclaimed_slab;
85};
86
87#ifdef __KERNEL__
88
89struct address_space;
90struct sysinfo;
91struct writeback_control;
92struct zone;
93
94/*
95 * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of
96 * disk blocks. A list of swap extents maps the entire swapfile. (Where the
97 * term `swapfile' refers to either a blockdevice or an IS_REG file. Apart
98 * from setup, they're handled identically.
99 *
100 * We always assume that blocks are of size PAGE_SIZE.
101 */
102struct swap_extent {
103 struct list_head list;
104 pgoff_t start_page;
105 pgoff_t nr_pages;
106 sector_t start_block;
107};
108
109/*
110 * Max bad pages in the new format..
111 */
112#define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x)
113#define MAX_SWAP_BADPAGES \
114 ((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int))
115
116enum {
117 SWP_USED = (1 << 0), /* is slot in swap_info[] used? */
118 SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */
119 SWP_ACTIVE = (SWP_USED | SWP_WRITEOK),
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120 /* add others here before... */
121 SWP_SCANNING = (1 << 8), /* refcount in scan_swap_map */
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122};
123
124#define SWAP_CLUSTER_MAX 32
125
126#define SWAP_MAP_MAX 0x7fff
127#define SWAP_MAP_BAD 0x8000
128
129/*
130 * The in-memory structure used to track swap areas.
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131 */
132struct swap_info_struct {
133 unsigned int flags;
5d337b91 134 int prio; /* swap priority */
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135 struct file *swap_file;
136 struct block_device *bdev;
137 struct list_head extent_list;
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138 struct swap_extent *curr_swap_extent;
139 unsigned old_block_size;
140 unsigned short * swap_map;
141 unsigned int lowest_bit;
142 unsigned int highest_bit;
143 unsigned int cluster_next;
144 unsigned int cluster_nr;
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145 unsigned int pages;
146 unsigned int max;
147 unsigned int inuse_pages;
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148 int next; /* next entry on swap list */
149};
150
151struct swap_list_t {
152 int head; /* head of priority-ordered swapfile list */
153 int next; /* swapfile to be used next */
154};
155
156/* Swap 50% full? Release swapcache more aggressively.. */
157#define vm_swap_full() (nr_swap_pages*2 < total_swap_pages)
158
159/* linux/mm/oom_kill.c */
9b0f8b04 160extern void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order);
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161extern int register_oom_notifier(struct notifier_block *nb);
162extern int unregister_oom_notifier(struct notifier_block *nb);
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163
164/* linux/mm/memory.c */
165extern void swapin_readahead(swp_entry_t, unsigned long, struct vm_area_struct *);
166
167/* linux/mm/page_alloc.c */
168extern unsigned long totalram_pages;
cb45b0e9 169extern unsigned long totalreserve_pages;
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170extern long nr_swap_pages;
171extern unsigned int nr_free_pages(void);
172extern unsigned int nr_free_pages_pgdat(pg_data_t *pgdat);
173extern unsigned int nr_free_buffer_pages(void);
174extern unsigned int nr_free_pagecache_pages(void);
175
176/* linux/mm/swap.c */
177extern void FASTCALL(lru_cache_add(struct page *));
178extern void FASTCALL(lru_cache_add_active(struct page *));
179extern void FASTCALL(activate_page(struct page *));
180extern void FASTCALL(mark_page_accessed(struct page *));
181extern void lru_add_drain(void);
053837fc 182extern int lru_add_drain_all(void);
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183extern int rotate_reclaimable_page(struct page *page);
184extern void swap_setup(void);
185
186/* linux/mm/vmscan.c */
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187extern unsigned long try_to_free_pages(struct zone **, gfp_t);
188extern unsigned long shrink_all_memory(unsigned long nr_pages);
1da177e4 189extern int vm_swappiness;
b20a3503 190extern int remove_mapping(struct address_space *mapping, struct page *page);
bd1e22b8 191extern long vm_total_pages;
b20a3503 192
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193#ifdef CONFIG_NUMA
194extern int zone_reclaim_mode;
9614634f 195extern int sysctl_min_unmapped_ratio;
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196extern int zone_reclaim(struct zone *, gfp_t, unsigned int);
197#else
198#define zone_reclaim_mode 0
199static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order)
200{
201 return 0;
202}
203#endif
204
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205extern int kswapd_run(int nid);
206
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207#ifdef CONFIG_MMU
208/* linux/mm/shmem.c */
209extern int shmem_unuse(swp_entry_t entry, struct page *page);
210#endif /* CONFIG_MMU */
211
212extern void swap_unplug_io_fn(struct backing_dev_info *, struct page *);
213
214#ifdef CONFIG_SWAP
215/* linux/mm/page_io.c */
216extern int swap_readpage(struct file *, struct page *);
217extern int swap_writepage(struct page *page, struct writeback_control *wbc);
218extern int rw_swap_page_sync(int, swp_entry_t, struct page *);
219
220/* linux/mm/swap_state.c */
221extern struct address_space swapper_space;
222#define total_swapcache_pages swapper_space.nrpages
223extern void show_swap_cache_info(void);
1480a540 224extern int add_to_swap(struct page *, gfp_t);
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225extern void __delete_from_swap_cache(struct page *);
226extern void delete_from_swap_cache(struct page *);
227extern int move_to_swap_cache(struct page *, swp_entry_t);
228extern int move_from_swap_cache(struct page *, unsigned long,
229 struct address_space *);
230extern void free_page_and_swap_cache(struct page *);
231extern void free_pages_and_swap_cache(struct page **, int);
232extern struct page * lookup_swap_cache(swp_entry_t);
233extern struct page * read_swap_cache_async(swp_entry_t, struct vm_area_struct *vma,
234 unsigned long addr);
235/* linux/mm/swapfile.c */
236extern long total_swap_pages;
237extern unsigned int nr_swapfiles;
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238extern void si_swapinfo(struct sysinfo *);
239extern swp_entry_t get_swap_page(void);
f577eb30 240extern swp_entry_t get_swap_page_of_type(int);
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241extern int swap_duplicate(swp_entry_t);
242extern int valid_swaphandles(swp_entry_t, unsigned long *);
243extern void swap_free(swp_entry_t);
244extern void free_swap_and_cache(swp_entry_t);
f577eb30
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245extern int swap_type_of(dev_t);
246extern unsigned int count_swap_pages(int, int);
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247extern sector_t map_swap_page(struct swap_info_struct *, pgoff_t);
248extern struct swap_info_struct *get_swap_info_struct(unsigned);
249extern int can_share_swap_page(struct page *);
250extern int remove_exclusive_swap_page(struct page *);
251struct backing_dev_info;
252
5d337b91 253extern spinlock_t swap_lock;
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254
255/* linux/mm/thrash.c */
256extern struct mm_struct * swap_token_mm;
257extern unsigned long swap_token_default_timeout;
258extern void grab_swap_token(void);
259extern void __put_swap_token(struct mm_struct *);
260
261static inline int has_swap_token(struct mm_struct *mm)
262{
263 return (mm == swap_token_mm);
264}
265
266static inline void put_swap_token(struct mm_struct *mm)
267{
268 if (has_swap_token(mm))
269 __put_swap_token(mm);
270}
271
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272static inline void disable_swap_token(void)
273{
274 put_swap_token(swap_token_mm);
275}
276
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277#else /* CONFIG_SWAP */
278
279#define total_swap_pages 0
280#define total_swapcache_pages 0UL
281
282#define si_swapinfo(val) \
283 do { (val)->freeswap = (val)->totalswap = 0; } while (0)
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284/* only sparc can not include linux/pagemap.h in this file
285 * so leave page_cache_release and release_pages undeclared... */
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286#define free_page_and_swap_cache(page) \
287 page_cache_release(page)
288#define free_pages_and_swap_cache(pages, nr) \
289 release_pages((pages), (nr), 0);
290
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291static inline void show_swap_cache_info(void)
292{
293}
294
295static inline void free_swap_and_cache(swp_entry_t swp)
296{
297}
298
299static inline int swap_duplicate(swp_entry_t swp)
300{
301 return 0;
302}
303
304static inline void swap_free(swp_entry_t swp)
305{
306}
307
308static inline struct page *read_swap_cache_async(swp_entry_t swp,
309 struct vm_area_struct *vma, unsigned long addr)
310{
311 return NULL;
312}
313
314static inline struct page *lookup_swap_cache(swp_entry_t swp)
315{
316 return NULL;
317}
318
319static inline int valid_swaphandles(swp_entry_t entry, unsigned long *offset)
320{
321 return 0;
322}
323
e6333fd4 324#define can_share_swap_page(p) (page_mapcount(p) == 1)
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325
326static inline int move_to_swap_cache(struct page *page, swp_entry_t entry)
327{
328 return 1;
329}
330
331static inline int move_from_swap_cache(struct page *page, unsigned long index,
332 struct address_space *mapping)
333{
334 return 1;
335}
336
337static inline void __delete_from_swap_cache(struct page *page)
338{
339}
340
341static inline void delete_from_swap_cache(struct page *page)
342{
343}
344
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345#define swap_token_default_timeout 0
346
347static inline int remove_exclusive_swap_page(struct page *p)
348{
349 return 0;
350}
351
352static inline swp_entry_t get_swap_page(void)
353{
354 swp_entry_t entry;
355 entry.val = 0;
356 return entry;
357}
358
359/* linux/mm/thrash.c */
360#define put_swap_token(x) do { } while(0)
361#define grab_swap_token() do { } while(0)
362#define has_swap_token(x) 0
f7b7fd8f 363#define disable_swap_token() do { } while(0)
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364
365#endif /* CONFIG_SWAP */
366#endif /* __KERNEL__*/
367#endif /* _LINUX_SWAP_H */