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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef _LINUX_MMZONE_H |
3 | #define _LINUX_MMZONE_H | |
4 | ||
1da177e4 | 5 | #ifndef __ASSEMBLY__ |
97965478 | 6 | #ifndef __GENERATING_BOUNDS_H |
1da177e4 | 7 | |
1da177e4 LT |
8 | #include <linux/spinlock.h> |
9 | #include <linux/list.h> | |
10 | #include <linux/wait.h> | |
e815af95 | 11 | #include <linux/bitops.h> |
1da177e4 LT |
12 | #include <linux/cache.h> |
13 | #include <linux/threads.h> | |
14 | #include <linux/numa.h> | |
15 | #include <linux/init.h> | |
bdc8cb98 | 16 | #include <linux/seqlock.h> |
8357f869 | 17 | #include <linux/nodemask.h> |
835c134e | 18 | #include <linux/pageblock-flags.h> |
bbeae5b0 | 19 | #include <linux/page-flags-layout.h> |
60063497 | 20 | #include <linux/atomic.h> |
b03641af DW |
21 | #include <linux/mm_types.h> |
22 | #include <linux/page-flags.h> | |
93ff66bf | 23 | #include <asm/page.h> |
1da177e4 LT |
24 | |
25 | /* Free memory management - zoned buddy allocator. */ | |
26 | #ifndef CONFIG_FORCE_MAX_ZONEORDER | |
27 | #define MAX_ORDER 11 | |
28 | #else | |
29 | #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER | |
30 | #endif | |
e984bb43 | 31 | #define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1)) |
1da177e4 | 32 | |
5ad333eb AW |
33 | /* |
34 | * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed | |
35 | * costly to service. That is between allocation orders which should | |
35fca53e | 36 | * coalesce naturally under reasonable reclaim pressure and those which |
5ad333eb AW |
37 | * will not. |
38 | */ | |
39 | #define PAGE_ALLOC_COSTLY_ORDER 3 | |
40 | ||
a6ffdc07 | 41 | enum migratetype { |
47118af0 | 42 | MIGRATE_UNMOVABLE, |
47118af0 | 43 | MIGRATE_MOVABLE, |
016c13da | 44 | MIGRATE_RECLAIMABLE, |
0aaa29a5 MG |
45 | MIGRATE_PCPTYPES, /* the number of types on the pcp lists */ |
46 | MIGRATE_HIGHATOMIC = MIGRATE_PCPTYPES, | |
47118af0 MN |
47 | #ifdef CONFIG_CMA |
48 | /* | |
49 | * MIGRATE_CMA migration type is designed to mimic the way | |
50 | * ZONE_MOVABLE works. Only movable pages can be allocated | |
51 | * from MIGRATE_CMA pageblocks and page allocator never | |
52 | * implicitly change migration type of MIGRATE_CMA pageblock. | |
53 | * | |
54 | * The way to use it is to change migratetype of a range of | |
55 | * pageblocks to MIGRATE_CMA which can be done by | |
56 | * __free_pageblock_cma() function. What is important though | |
57 | * is that a range of pageblocks must be aligned to | |
58 | * MAX_ORDER_NR_PAGES should biggest page be bigger then | |
59 | * a single pageblock. | |
60 | */ | |
61 | MIGRATE_CMA, | |
62 | #endif | |
194159fb | 63 | #ifdef CONFIG_MEMORY_ISOLATION |
47118af0 | 64 | MIGRATE_ISOLATE, /* can't allocate from here */ |
194159fb | 65 | #endif |
47118af0 MN |
66 | MIGRATE_TYPES |
67 | }; | |
68 | ||
60f30350 | 69 | /* In mm/page_alloc.c; keep in sync also with show_migration_types() there */ |
c999fbd3 | 70 | extern const char * const migratetype_names[MIGRATE_TYPES]; |
60f30350 | 71 | |
47118af0 MN |
72 | #ifdef CONFIG_CMA |
73 | # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA) | |
7c15d9bb | 74 | # define is_migrate_cma_page(_page) (get_pageblock_migratetype(_page) == MIGRATE_CMA) |
47118af0 MN |
75 | #else |
76 | # define is_migrate_cma(migratetype) false | |
7c15d9bb | 77 | # define is_migrate_cma_page(_page) false |
47118af0 | 78 | #endif |
b2a0ac88 | 79 | |
b682debd VB |
80 | static inline bool is_migrate_movable(int mt) |
81 | { | |
82 | return is_migrate_cma(mt) || mt == MIGRATE_MOVABLE; | |
83 | } | |
84 | ||
b2a0ac88 MG |
85 | #define for_each_migratetype_order(order, type) \ |
86 | for (order = 0; order < MAX_ORDER; order++) \ | |
87 | for (type = 0; type < MIGRATE_TYPES; type++) | |
88 | ||
467c996c MG |
89 | extern int page_group_by_mobility_disabled; |
90 | ||
e58469ba MG |
91 | #define NR_MIGRATETYPE_BITS (PB_migrate_end - PB_migrate + 1) |
92 | #define MIGRATETYPE_MASK ((1UL << NR_MIGRATETYPE_BITS) - 1) | |
93 | ||
dc4b0caf MG |
94 | #define get_pageblock_migratetype(page) \ |
95 | get_pfnblock_flags_mask(page, page_to_pfn(page), \ | |
96 | PB_migrate_end, MIGRATETYPE_MASK) | |
97 | ||
1da177e4 | 98 | struct free_area { |
b2a0ac88 | 99 | struct list_head free_list[MIGRATE_TYPES]; |
1da177e4 LT |
100 | unsigned long nr_free; |
101 | }; | |
102 | ||
b03641af DW |
103 | /* Used for pages not on another list */ |
104 | static inline void add_to_free_area(struct page *page, struct free_area *area, | |
105 | int migratetype) | |
106 | { | |
107 | list_add(&page->lru, &area->free_list[migratetype]); | |
108 | area->nr_free++; | |
109 | } | |
110 | ||
111 | /* Used for pages not on another list */ | |
112 | static inline void add_to_free_area_tail(struct page *page, struct free_area *area, | |
113 | int migratetype) | |
114 | { | |
115 | list_add_tail(&page->lru, &area->free_list[migratetype]); | |
116 | area->nr_free++; | |
117 | } | |
118 | ||
97500a4a DW |
119 | #ifdef CONFIG_SHUFFLE_PAGE_ALLOCATOR |
120 | /* Used to preserve page allocation order entropy */ | |
121 | void add_to_free_area_random(struct page *page, struct free_area *area, | |
122 | int migratetype); | |
123 | #else | |
124 | static inline void add_to_free_area_random(struct page *page, | |
125 | struct free_area *area, int migratetype) | |
126 | { | |
127 | add_to_free_area(page, area, migratetype); | |
128 | } | |
129 | #endif | |
130 | ||
b03641af DW |
131 | /* Used for pages which are on another list */ |
132 | static inline void move_to_free_area(struct page *page, struct free_area *area, | |
133 | int migratetype) | |
134 | { | |
135 | list_move(&page->lru, &area->free_list[migratetype]); | |
136 | } | |
137 | ||
138 | static inline struct page *get_page_from_free_area(struct free_area *area, | |
139 | int migratetype) | |
140 | { | |
141 | return list_first_entry_or_null(&area->free_list[migratetype], | |
142 | struct page, lru); | |
143 | } | |
144 | ||
145 | static inline void del_page_from_free_area(struct page *page, | |
146 | struct free_area *area) | |
147 | { | |
148 | list_del(&page->lru); | |
149 | __ClearPageBuddy(page); | |
150 | set_page_private(page, 0); | |
151 | area->nr_free--; | |
152 | } | |
153 | ||
154 | static inline bool free_area_empty(struct free_area *area, int migratetype) | |
155 | { | |
156 | return list_empty(&area->free_list[migratetype]); | |
157 | } | |
158 | ||
1da177e4 LT |
159 | struct pglist_data; |
160 | ||
161 | /* | |
a52633d8 | 162 | * zone->lock and the zone lru_lock are two of the hottest locks in the kernel. |
1da177e4 LT |
163 | * So add a wild amount of padding here to ensure that they fall into separate |
164 | * cachelines. There are very few zone structures in the machine, so space | |
165 | * consumption is not a concern here. | |
166 | */ | |
167 | #if defined(CONFIG_SMP) | |
168 | struct zone_padding { | |
169 | char x[0]; | |
22fc6ecc | 170 | } ____cacheline_internodealigned_in_smp; |
1da177e4 LT |
171 | #define ZONE_PADDING(name) struct zone_padding name; |
172 | #else | |
173 | #define ZONE_PADDING(name) | |
174 | #endif | |
175 | ||
3a321d2a KW |
176 | #ifdef CONFIG_NUMA |
177 | enum numa_stat_item { | |
178 | NUMA_HIT, /* allocated in intended node */ | |
179 | NUMA_MISS, /* allocated in non intended node */ | |
180 | NUMA_FOREIGN, /* was intended here, hit elsewhere */ | |
181 | NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */ | |
182 | NUMA_LOCAL, /* allocation from local node */ | |
183 | NUMA_OTHER, /* allocation from other node */ | |
184 | NR_VM_NUMA_STAT_ITEMS | |
185 | }; | |
186 | #else | |
187 | #define NR_VM_NUMA_STAT_ITEMS 0 | |
188 | #endif | |
189 | ||
2244b95a | 190 | enum zone_stat_item { |
51ed4491 | 191 | /* First 128 byte cacheline (assuming 64 bit words) */ |
d23ad423 | 192 | NR_FREE_PAGES, |
71c799f4 MK |
193 | NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */ |
194 | NR_ZONE_INACTIVE_ANON = NR_ZONE_LRU_BASE, | |
195 | NR_ZONE_ACTIVE_ANON, | |
196 | NR_ZONE_INACTIVE_FILE, | |
197 | NR_ZONE_ACTIVE_FILE, | |
198 | NR_ZONE_UNEVICTABLE, | |
5a1c84b4 | 199 | NR_ZONE_WRITE_PENDING, /* Count of dirty, writeback and unstable pages */ |
5344b7e6 | 200 | NR_MLOCK, /* mlock()ed pages found and moved off LRU */ |
51ed4491 | 201 | NR_PAGETABLE, /* used for pagetables */ |
d30dd8be | 202 | NR_KERNEL_STACK_KB, /* measured in KiB */ |
c6a7f572 | 203 | /* Second 128 byte cacheline */ |
d2c5e30c | 204 | NR_BOUNCE, |
91537fee MK |
205 | #if IS_ENABLED(CONFIG_ZSMALLOC) |
206 | NR_ZSPAGES, /* allocated in zsmalloc */ | |
ca889e6c | 207 | #endif |
d1ce749a | 208 | NR_FREE_CMA_PAGES, |
2244b95a CL |
209 | NR_VM_ZONE_STAT_ITEMS }; |
210 | ||
75ef7184 | 211 | enum node_stat_item { |
599d0c95 MG |
212 | NR_LRU_BASE, |
213 | NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */ | |
214 | NR_ACTIVE_ANON, /* " " " " " */ | |
215 | NR_INACTIVE_FILE, /* " " " " " */ | |
216 | NR_ACTIVE_FILE, /* " " " " " */ | |
217 | NR_UNEVICTABLE, /* " " " " " */ | |
385386cf JW |
218 | NR_SLAB_RECLAIMABLE, |
219 | NR_SLAB_UNRECLAIMABLE, | |
599d0c95 MG |
220 | NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */ |
221 | NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */ | |
68d48e6a | 222 | WORKINGSET_NODES, |
1e6b1085 MG |
223 | WORKINGSET_REFAULT, |
224 | WORKINGSET_ACTIVATE, | |
1899ad18 | 225 | WORKINGSET_RESTORE, |
1e6b1085 | 226 | WORKINGSET_NODERECLAIM, |
4b9d0fab | 227 | NR_ANON_MAPPED, /* Mapped anonymous pages */ |
50658e2e MG |
228 | NR_FILE_MAPPED, /* pagecache pages mapped into pagetables. |
229 | only modified from process context */ | |
11fb9989 MG |
230 | NR_FILE_PAGES, |
231 | NR_FILE_DIRTY, | |
232 | NR_WRITEBACK, | |
233 | NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */ | |
234 | NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */ | |
235 | NR_SHMEM_THPS, | |
236 | NR_SHMEM_PMDMAPPED, | |
237 | NR_ANON_THPS, | |
238 | NR_UNSTABLE_NFS, /* NFS unstable pages */ | |
c4a25635 MG |
239 | NR_VMSCAN_WRITE, |
240 | NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */ | |
241 | NR_DIRTIED, /* page dirtyings since bootup */ | |
242 | NR_WRITTEN, /* page writings since bootup */ | |
b29940c1 | 243 | NR_KERNEL_MISC_RECLAIMABLE, /* reclaimable non-slab kernel pages */ |
75ef7184 MG |
244 | NR_VM_NODE_STAT_ITEMS |
245 | }; | |
246 | ||
4f98a2fe RR |
247 | /* |
248 | * We do arithmetic on the LRU lists in various places in the code, | |
249 | * so it is important to keep the active lists LRU_ACTIVE higher in | |
250 | * the array than the corresponding inactive lists, and to keep | |
251 | * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists. | |
252 | * | |
253 | * This has to be kept in sync with the statistics in zone_stat_item | |
254 | * above and the descriptions in vmstat_text in mm/vmstat.c | |
255 | */ | |
256 | #define LRU_BASE 0 | |
257 | #define LRU_ACTIVE 1 | |
258 | #define LRU_FILE 2 | |
259 | ||
b69408e8 | 260 | enum lru_list { |
4f98a2fe RR |
261 | LRU_INACTIVE_ANON = LRU_BASE, |
262 | LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE, | |
263 | LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE, | |
264 | LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE, | |
894bc310 | 265 | LRU_UNEVICTABLE, |
894bc310 LS |
266 | NR_LRU_LISTS |
267 | }; | |
b69408e8 | 268 | |
4111304d | 269 | #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++) |
b69408e8 | 270 | |
4111304d | 271 | #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++) |
894bc310 | 272 | |
4111304d | 273 | static inline int is_file_lru(enum lru_list lru) |
4f98a2fe | 274 | { |
4111304d | 275 | return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE); |
4f98a2fe RR |
276 | } |
277 | ||
4111304d | 278 | static inline int is_active_lru(enum lru_list lru) |
b69408e8 | 279 | { |
4111304d | 280 | return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE); |
b69408e8 CL |
281 | } |
282 | ||
89abfab1 HD |
283 | struct zone_reclaim_stat { |
284 | /* | |
285 | * The pageout code in vmscan.c keeps track of how many of the | |
59f91e5d | 286 | * mem/swap backed and file backed pages are referenced. |
89abfab1 HD |
287 | * The higher the rotated/scanned ratio, the more valuable |
288 | * that cache is. | |
289 | * | |
290 | * The anon LRU stats live in [0], file LRU stats in [1] | |
291 | */ | |
292 | unsigned long recent_rotated[2]; | |
293 | unsigned long recent_scanned[2]; | |
294 | }; | |
295 | ||
6290df54 | 296 | struct lruvec { |
23047a96 JW |
297 | struct list_head lists[NR_LRU_LISTS]; |
298 | struct zone_reclaim_stat reclaim_stat; | |
299 | /* Evictions & activations on the inactive file list */ | |
300 | atomic_long_t inactive_age; | |
2a2e4885 JW |
301 | /* Refaults at the time of last reclaim cycle */ |
302 | unsigned long refaults; | |
c255a458 | 303 | #ifdef CONFIG_MEMCG |
599d0c95 | 304 | struct pglist_data *pgdat; |
7f5e86c2 | 305 | #endif |
6290df54 JW |
306 | }; |
307 | ||
f80c0673 | 308 | /* Isolate unmapped file */ |
f3fd4a61 | 309 | #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2) |
c8244935 | 310 | /* Isolate for asynchronous migration */ |
f3fd4a61 | 311 | #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4) |
e46a2879 MK |
312 | /* Isolate unevictable pages */ |
313 | #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8) | |
4356f21d MK |
314 | |
315 | /* LRU Isolation modes. */ | |
9efeccac | 316 | typedef unsigned __bitwise isolate_mode_t; |
4356f21d | 317 | |
41858966 MG |
318 | enum zone_watermarks { |
319 | WMARK_MIN, | |
320 | WMARK_LOW, | |
321 | WMARK_HIGH, | |
322 | NR_WMARK | |
323 | }; | |
324 | ||
1c30844d MG |
325 | #define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost) |
326 | #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost) | |
327 | #define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost) | |
328 | #define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost) | |
41858966 | 329 | |
1da177e4 LT |
330 | struct per_cpu_pages { |
331 | int count; /* number of pages in the list */ | |
1da177e4 LT |
332 | int high; /* high watermark, emptying needed */ |
333 | int batch; /* chunk size for buddy add/remove */ | |
5f8dcc21 MG |
334 | |
335 | /* Lists of pages, one per migrate type stored on the pcp-lists */ | |
336 | struct list_head lists[MIGRATE_PCPTYPES]; | |
1da177e4 LT |
337 | }; |
338 | ||
339 | struct per_cpu_pageset { | |
3dfa5721 | 340 | struct per_cpu_pages pcp; |
4037d452 CL |
341 | #ifdef CONFIG_NUMA |
342 | s8 expire; | |
1d90ca89 | 343 | u16 vm_numa_stat_diff[NR_VM_NUMA_STAT_ITEMS]; |
4037d452 | 344 | #endif |
2244b95a | 345 | #ifdef CONFIG_SMP |
df9ecaba | 346 | s8 stat_threshold; |
2244b95a CL |
347 | s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS]; |
348 | #endif | |
99dcc3e5 | 349 | }; |
e7c8d5c9 | 350 | |
75ef7184 MG |
351 | struct per_cpu_nodestat { |
352 | s8 stat_threshold; | |
353 | s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS]; | |
354 | }; | |
355 | ||
97965478 CL |
356 | #endif /* !__GENERATING_BOUNDS.H */ |
357 | ||
2f1b6248 | 358 | enum zone_type { |
4b51d669 | 359 | #ifdef CONFIG_ZONE_DMA |
2f1b6248 CL |
360 | /* |
361 | * ZONE_DMA is used when there are devices that are not able | |
362 | * to do DMA to all of addressable memory (ZONE_NORMAL). Then we | |
363 | * carve out the portion of memory that is needed for these devices. | |
364 | * The range is arch specific. | |
365 | * | |
366 | * Some examples | |
367 | * | |
368 | * Architecture Limit | |
369 | * --------------------------- | |
370 | * parisc, ia64, sparc <4G | |
25078dc1 | 371 | * s390, powerpc <2G |
2f1b6248 CL |
372 | * arm Various |
373 | * alpha Unlimited or 0-16MB. | |
374 | * | |
375 | * i386, x86_64 and multiple other arches | |
376 | * <16M. | |
377 | */ | |
378 | ZONE_DMA, | |
4b51d669 | 379 | #endif |
fb0e7942 | 380 | #ifdef CONFIG_ZONE_DMA32 |
2f1b6248 CL |
381 | /* |
382 | * x86_64 needs two ZONE_DMAs because it supports devices that are | |
383 | * only able to do DMA to the lower 16M but also 32 bit devices that | |
384 | * can only do DMA areas below 4G. | |
385 | */ | |
386 | ZONE_DMA32, | |
fb0e7942 | 387 | #endif |
2f1b6248 CL |
388 | /* |
389 | * Normal addressable memory is in ZONE_NORMAL. DMA operations can be | |
390 | * performed on pages in ZONE_NORMAL if the DMA devices support | |
391 | * transfers to all addressable memory. | |
392 | */ | |
393 | ZONE_NORMAL, | |
e53ef38d | 394 | #ifdef CONFIG_HIGHMEM |
2f1b6248 CL |
395 | /* |
396 | * A memory area that is only addressable by the kernel through | |
397 | * mapping portions into its own address space. This is for example | |
398 | * used by i386 to allow the kernel to address the memory beyond | |
399 | * 900MB. The kernel will set up special mappings (page | |
400 | * table entries on i386) for each page that the kernel needs to | |
401 | * access. | |
402 | */ | |
403 | ZONE_HIGHMEM, | |
e53ef38d | 404 | #endif |
2a1e274a | 405 | ZONE_MOVABLE, |
033fbae9 DW |
406 | #ifdef CONFIG_ZONE_DEVICE |
407 | ZONE_DEVICE, | |
408 | #endif | |
97965478 | 409 | __MAX_NR_ZONES |
033fbae9 | 410 | |
2f1b6248 | 411 | }; |
1da177e4 | 412 | |
97965478 CL |
413 | #ifndef __GENERATING_BOUNDS_H |
414 | ||
1da177e4 | 415 | struct zone { |
3484b2de | 416 | /* Read-mostly fields */ |
41858966 MG |
417 | |
418 | /* zone watermarks, access with *_wmark_pages(zone) macros */ | |
a9214443 | 419 | unsigned long _watermark[NR_WMARK]; |
1c30844d | 420 | unsigned long watermark_boost; |
41858966 | 421 | |
0aaa29a5 MG |
422 | unsigned long nr_reserved_highatomic; |
423 | ||
1da177e4 | 424 | /* |
89903327 AM |
425 | * We don't know if the memory that we're going to allocate will be |
426 | * freeable or/and it will be released eventually, so to avoid totally | |
427 | * wasting several GB of ram we must reserve some of the lower zone | |
428 | * memory (otherwise we risk to run OOM on the lower zones despite | |
429 | * there being tons of freeable ram on the higher zones). This array is | |
430 | * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl | |
431 | * changes. | |
1da177e4 | 432 | */ |
3484b2de | 433 | long lowmem_reserve[MAX_NR_ZONES]; |
ab8fabd4 | 434 | |
e7c8d5c9 | 435 | #ifdef CONFIG_NUMA |
d5f541ed | 436 | int node; |
3484b2de | 437 | #endif |
3484b2de | 438 | struct pglist_data *zone_pgdat; |
43cf38eb | 439 | struct per_cpu_pageset __percpu *pageset; |
3484b2de | 440 | |
835c134e MG |
441 | #ifndef CONFIG_SPARSEMEM |
442 | /* | |
d9c23400 | 443 | * Flags for a pageblock_nr_pages block. See pageblock-flags.h. |
835c134e MG |
444 | * In SPARSEMEM, this map is stored in struct mem_section |
445 | */ | |
446 | unsigned long *pageblock_flags; | |
447 | #endif /* CONFIG_SPARSEMEM */ | |
448 | ||
1da177e4 LT |
449 | /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */ |
450 | unsigned long zone_start_pfn; | |
451 | ||
bdc8cb98 | 452 | /* |
9feedc9d JL |
453 | * spanned_pages is the total pages spanned by the zone, including |
454 | * holes, which is calculated as: | |
455 | * spanned_pages = zone_end_pfn - zone_start_pfn; | |
bdc8cb98 | 456 | * |
9feedc9d JL |
457 | * present_pages is physical pages existing within the zone, which |
458 | * is calculated as: | |
8761e31c | 459 | * present_pages = spanned_pages - absent_pages(pages in holes); |
9feedc9d JL |
460 | * |
461 | * managed_pages is present pages managed by the buddy system, which | |
462 | * is calculated as (reserved_pages includes pages allocated by the | |
463 | * bootmem allocator): | |
464 | * managed_pages = present_pages - reserved_pages; | |
465 | * | |
466 | * So present_pages may be used by memory hotplug or memory power | |
467 | * management logic to figure out unmanaged pages by checking | |
468 | * (present_pages - managed_pages). And managed_pages should be used | |
469 | * by page allocator and vm scanner to calculate all kinds of watermarks | |
470 | * and thresholds. | |
471 | * | |
472 | * Locking rules: | |
473 | * | |
474 | * zone_start_pfn and spanned_pages are protected by span_seqlock. | |
475 | * It is a seqlock because it has to be read outside of zone->lock, | |
476 | * and it is done in the main allocator path. But, it is written | |
477 | * quite infrequently. | |
478 | * | |
479 | * The span_seq lock is declared along with zone->lock because it is | |
bdc8cb98 DH |
480 | * frequently read in proximity to zone->lock. It's good to |
481 | * give them a chance of being in the same cacheline. | |
9feedc9d | 482 | * |
c3d5f5f0 | 483 | * Write access to present_pages at runtime should be protected by |
bfc8c901 VD |
484 | * mem_hotplug_begin/end(). Any reader who can't tolerant drift of |
485 | * present_pages should get_online_mems() to get a stable value. | |
bdc8cb98 | 486 | */ |
9705bea5 | 487 | atomic_long_t managed_pages; |
9feedc9d JL |
488 | unsigned long spanned_pages; |
489 | unsigned long present_pages; | |
3484b2de MG |
490 | |
491 | const char *name; | |
1da177e4 | 492 | |
ad53f92e JK |
493 | #ifdef CONFIG_MEMORY_ISOLATION |
494 | /* | |
495 | * Number of isolated pageblock. It is used to solve incorrect | |
496 | * freepage counting problem due to racy retrieving migratetype | |
497 | * of pageblock. Protected by zone->lock. | |
498 | */ | |
499 | unsigned long nr_isolate_pageblock; | |
500 | #endif | |
501 | ||
3484b2de MG |
502 | #ifdef CONFIG_MEMORY_HOTPLUG |
503 | /* see spanned/present_pages for more description */ | |
504 | seqlock_t span_seqlock; | |
505 | #endif | |
506 | ||
9dcb8b68 | 507 | int initialized; |
3484b2de | 508 | |
0f661148 | 509 | /* Write-intensive fields used from the page allocator */ |
3484b2de | 510 | ZONE_PADDING(_pad1_) |
0f661148 | 511 | |
3484b2de MG |
512 | /* free areas of different sizes */ |
513 | struct free_area free_area[MAX_ORDER]; | |
514 | ||
515 | /* zone flags, see below */ | |
516 | unsigned long flags; | |
517 | ||
0f661148 | 518 | /* Primarily protects free_area */ |
a368ab67 MG |
519 | spinlock_t lock; |
520 | ||
0f661148 | 521 | /* Write-intensive fields used by compaction and vmstats. */ |
3484b2de MG |
522 | ZONE_PADDING(_pad2_) |
523 | ||
3484b2de MG |
524 | /* |
525 | * When free pages are below this point, additional steps are taken | |
526 | * when reading the number of free pages to avoid per-cpu counter | |
527 | * drift allowing watermarks to be breached | |
528 | */ | |
529 | unsigned long percpu_drift_mark; | |
530 | ||
531 | #if defined CONFIG_COMPACTION || defined CONFIG_CMA | |
532 | /* pfn where compaction free scanner should start */ | |
533 | unsigned long compact_cached_free_pfn; | |
534 | /* pfn where async and sync compaction migration scanner should start */ | |
535 | unsigned long compact_cached_migrate_pfn[2]; | |
e332f741 MG |
536 | unsigned long compact_init_migrate_pfn; |
537 | unsigned long compact_init_free_pfn; | |
3484b2de MG |
538 | #endif |
539 | ||
540 | #ifdef CONFIG_COMPACTION | |
541 | /* | |
542 | * On compaction failure, 1<<compact_defer_shift compactions | |
543 | * are skipped before trying again. The number attempted since | |
544 | * last failure is tracked with compact_considered. | |
545 | */ | |
546 | unsigned int compact_considered; | |
547 | unsigned int compact_defer_shift; | |
548 | int compact_order_failed; | |
549 | #endif | |
550 | ||
551 | #if defined CONFIG_COMPACTION || defined CONFIG_CMA | |
552 | /* Set to true when the PG_migrate_skip bits should be cleared */ | |
553 | bool compact_blockskip_flush; | |
554 | #endif | |
555 | ||
7cf91a98 JK |
556 | bool contiguous; |
557 | ||
3484b2de MG |
558 | ZONE_PADDING(_pad3_) |
559 | /* Zone statistics */ | |
560 | atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; | |
3a321d2a | 561 | atomic_long_t vm_numa_stat[NR_VM_NUMA_STAT_ITEMS]; |
22fc6ecc | 562 | } ____cacheline_internodealigned_in_smp; |
1da177e4 | 563 | |
599d0c95 MG |
564 | enum pgdat_flags { |
565 | PGDAT_CONGESTED, /* pgdat has many dirty pages backed by | |
0e093d99 MG |
566 | * a congested BDI |
567 | */ | |
599d0c95 | 568 | PGDAT_DIRTY, /* reclaim scanning has recently found |
d43006d5 MG |
569 | * many dirty file pages at the tail |
570 | * of the LRU. | |
571 | */ | |
599d0c95 | 572 | PGDAT_WRITEBACK, /* reclaim scanning has recently found |
283aba9f MG |
573 | * many pages under writeback |
574 | */ | |
a5f5f91d | 575 | PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */ |
57054651 | 576 | }; |
e815af95 | 577 | |
73444bc4 MG |
578 | enum zone_flags { |
579 | ZONE_BOOSTED_WATERMARK, /* zone recently boosted watermarks. | |
580 | * Cleared when kswapd is woken. | |
581 | */ | |
582 | }; | |
583 | ||
9705bea5 AK |
584 | static inline unsigned long zone_managed_pages(struct zone *zone) |
585 | { | |
586 | return (unsigned long)atomic_long_read(&zone->managed_pages); | |
587 | } | |
588 | ||
f9228b20 | 589 | static inline unsigned long zone_end_pfn(const struct zone *zone) |
108bcc96 CS |
590 | { |
591 | return zone->zone_start_pfn + zone->spanned_pages; | |
592 | } | |
593 | ||
594 | static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn) | |
595 | { | |
596 | return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone); | |
597 | } | |
598 | ||
2a6e3ebe CS |
599 | static inline bool zone_is_initialized(struct zone *zone) |
600 | { | |
9dcb8b68 | 601 | return zone->initialized; |
2a6e3ebe CS |
602 | } |
603 | ||
604 | static inline bool zone_is_empty(struct zone *zone) | |
605 | { | |
606 | return zone->spanned_pages == 0; | |
607 | } | |
608 | ||
f1dd2cd1 MH |
609 | /* |
610 | * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty | |
611 | * intersection with the given zone | |
612 | */ | |
613 | static inline bool zone_intersects(struct zone *zone, | |
614 | unsigned long start_pfn, unsigned long nr_pages) | |
615 | { | |
616 | if (zone_is_empty(zone)) | |
617 | return false; | |
618 | if (start_pfn >= zone_end_pfn(zone) || | |
619 | start_pfn + nr_pages <= zone->zone_start_pfn) | |
620 | return false; | |
621 | ||
622 | return true; | |
623 | } | |
624 | ||
1da177e4 LT |
625 | /* |
626 | * The "priority" of VM scanning is how much of the queues we will scan in one | |
627 | * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the | |
628 | * queues ("queue_length >> 12") during an aging round. | |
629 | */ | |
630 | #define DEF_PRIORITY 12 | |
631 | ||
9276b1bc PJ |
632 | /* Maximum number of zones on a zonelist */ |
633 | #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES) | |
634 | ||
c00eb15a YB |
635 | enum { |
636 | ZONELIST_FALLBACK, /* zonelist with fallback */ | |
9276b1bc | 637 | #ifdef CONFIG_NUMA |
c00eb15a YB |
638 | /* |
639 | * The NUMA zonelists are doubled because we need zonelists that | |
640 | * restrict the allocations to a single node for __GFP_THISNODE. | |
641 | */ | |
642 | ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */ | |
9276b1bc | 643 | #endif |
c00eb15a YB |
644 | MAX_ZONELISTS |
645 | }; | |
9276b1bc | 646 | |
dd1a239f MG |
647 | /* |
648 | * This struct contains information about a zone in a zonelist. It is stored | |
649 | * here to avoid dereferences into large structures and lookups of tables | |
650 | */ | |
651 | struct zoneref { | |
652 | struct zone *zone; /* Pointer to actual zone */ | |
653 | int zone_idx; /* zone_idx(zoneref->zone) */ | |
654 | }; | |
655 | ||
1da177e4 LT |
656 | /* |
657 | * One allocation request operates on a zonelist. A zonelist | |
658 | * is a list of zones, the first one is the 'goal' of the | |
659 | * allocation, the other zones are fallback zones, in decreasing | |
660 | * priority. | |
661 | * | |
dd1a239f MG |
662 | * To speed the reading of the zonelist, the zonerefs contain the zone index |
663 | * of the entry being read. Helper functions to access information given | |
664 | * a struct zoneref are | |
665 | * | |
666 | * zonelist_zone() - Return the struct zone * for an entry in _zonerefs | |
667 | * zonelist_zone_idx() - Return the index of the zone for an entry | |
668 | * zonelist_node_idx() - Return the index of the node for an entry | |
1da177e4 LT |
669 | */ |
670 | struct zonelist { | |
dd1a239f | 671 | struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1]; |
1da177e4 LT |
672 | }; |
673 | ||
5b99cd0e HC |
674 | #ifndef CONFIG_DISCONTIGMEM |
675 | /* The array of struct pages - for discontigmem use pgdat->lmem_map */ | |
676 | extern struct page *mem_map; | |
677 | #endif | |
678 | ||
1da177e4 | 679 | /* |
1da177e4 | 680 | * On NUMA machines, each NUMA node would have a pg_data_t to describe |
618b8c20 NB |
681 | * it's memory layout. On UMA machines there is a single pglist_data which |
682 | * describes the whole memory. | |
1da177e4 LT |
683 | * |
684 | * Memory statistics and page replacement data structures are maintained on a | |
685 | * per-zone basis. | |
686 | */ | |
687 | struct bootmem_data; | |
688 | typedef struct pglist_data { | |
689 | struct zone node_zones[MAX_NR_ZONES]; | |
523b9458 | 690 | struct zonelist node_zonelists[MAX_ZONELISTS]; |
1da177e4 | 691 | int nr_zones; |
52d4b9ac | 692 | #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */ |
1da177e4 | 693 | struct page *node_mem_map; |
eefa864b JK |
694 | #ifdef CONFIG_PAGE_EXTENSION |
695 | struct page_ext *node_page_ext; | |
696 | #endif | |
d41dee36 | 697 | #endif |
3a2d7fa8 | 698 | #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT) |
208d54e5 | 699 | /* |
fa004ab7 WY |
700 | * Must be held any time you expect node_start_pfn, |
701 | * node_present_pages, node_spanned_pages or nr_zones to stay constant. | |
208d54e5 | 702 | * |
114d4b79 | 703 | * pgdat_resize_lock() and pgdat_resize_unlock() are provided to |
3a2d7fa8 PT |
704 | * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG |
705 | * or CONFIG_DEFERRED_STRUCT_PAGE_INIT. | |
114d4b79 | 706 | * |
72c3b51b | 707 | * Nests above zone->lock and zone->span_seqlock |
208d54e5 DH |
708 | */ |
709 | spinlock_t node_size_lock; | |
710 | #endif | |
1da177e4 LT |
711 | unsigned long node_start_pfn; |
712 | unsigned long node_present_pages; /* total number of physical pages */ | |
713 | unsigned long node_spanned_pages; /* total size of physical page | |
714 | range, including holes */ | |
715 | int node_id; | |
1da177e4 | 716 | wait_queue_head_t kswapd_wait; |
5515061d | 717 | wait_queue_head_t pfmemalloc_wait; |
bfc8c901 VD |
718 | struct task_struct *kswapd; /* Protected by |
719 | mem_hotplug_begin/end() */ | |
38087d9b MG |
720 | int kswapd_order; |
721 | enum zone_type kswapd_classzone_idx; | |
722 | ||
c73322d0 JW |
723 | int kswapd_failures; /* Number of 'reclaimed == 0' runs */ |
724 | ||
698b1b30 VB |
725 | #ifdef CONFIG_COMPACTION |
726 | int kcompactd_max_order; | |
727 | enum zone_type kcompactd_classzone_idx; | |
728 | wait_queue_head_t kcompactd_wait; | |
729 | struct task_struct *kcompactd; | |
8177a420 | 730 | #endif |
281e3726 MG |
731 | /* |
732 | * This is a per-node reserve of pages that are not available | |
733 | * to userspace allocations. | |
734 | */ | |
735 | unsigned long totalreserve_pages; | |
736 | ||
a5f5f91d MG |
737 | #ifdef CONFIG_NUMA |
738 | /* | |
739 | * zone reclaim becomes active if more unmapped pages exist. | |
740 | */ | |
741 | unsigned long min_unmapped_pages; | |
742 | unsigned long min_slab_pages; | |
743 | #endif /* CONFIG_NUMA */ | |
744 | ||
a52633d8 MG |
745 | /* Write-intensive fields used by page reclaim */ |
746 | ZONE_PADDING(_pad1_) | |
747 | spinlock_t lru_lock; | |
3a80a7fa MG |
748 | |
749 | #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT | |
750 | /* | |
751 | * If memory initialisation on large machines is deferred then this | |
752 | * is the first PFN that needs to be initialised. | |
753 | */ | |
754 | unsigned long first_deferred_pfn; | |
755 | #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ | |
a3d0a918 KS |
756 | |
757 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
758 | spinlock_t split_queue_lock; | |
759 | struct list_head split_queue; | |
760 | unsigned long split_queue_len; | |
761 | #endif | |
75ef7184 | 762 | |
599d0c95 MG |
763 | /* Fields commonly accessed by the page reclaim scanner */ |
764 | struct lruvec lruvec; | |
765 | ||
599d0c95 MG |
766 | unsigned long flags; |
767 | ||
768 | ZONE_PADDING(_pad2_) | |
769 | ||
75ef7184 MG |
770 | /* Per-node vmstats */ |
771 | struct per_cpu_nodestat __percpu *per_cpu_nodestats; | |
772 | atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS]; | |
1da177e4 LT |
773 | } pg_data_t; |
774 | ||
775 | #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages) | |
776 | #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages) | |
d41dee36 | 777 | #ifdef CONFIG_FLAT_NODE_MEM_MAP |
408fde81 | 778 | #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr)) |
d41dee36 AW |
779 | #else |
780 | #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr)) | |
781 | #endif | |
408fde81 | 782 | #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr)) |
1da177e4 | 783 | |
c6830c22 | 784 | #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) |
da3649e1 | 785 | #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid)) |
c6830c22 | 786 | |
a9dd0a83 | 787 | static inline struct lruvec *node_lruvec(struct pglist_data *pgdat) |
599d0c95 | 788 | { |
a9dd0a83 | 789 | return &pgdat->lruvec; |
599d0c95 MG |
790 | } |
791 | ||
da3649e1 CS |
792 | static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat) |
793 | { | |
794 | return pgdat->node_start_pfn + pgdat->node_spanned_pages; | |
795 | } | |
796 | ||
797 | static inline bool pgdat_is_empty(pg_data_t *pgdat) | |
798 | { | |
799 | return !pgdat->node_start_pfn && !pgdat->node_spanned_pages; | |
800 | } | |
c6830c22 | 801 | |
208d54e5 DH |
802 | #include <linux/memory_hotplug.h> |
803 | ||
72675e13 | 804 | void build_all_zonelists(pg_data_t *pgdat); |
5ecd9d40 DR |
805 | void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order, |
806 | enum zone_type classzone_idx); | |
86a294a8 MH |
807 | bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, |
808 | int classzone_idx, unsigned int alloc_flags, | |
809 | long free_pages); | |
7aeb09f9 | 810 | bool zone_watermark_ok(struct zone *z, unsigned int order, |
c603844b MG |
811 | unsigned long mark, int classzone_idx, |
812 | unsigned int alloc_flags); | |
7aeb09f9 | 813 | bool zone_watermark_ok_safe(struct zone *z, unsigned int order, |
e2b19197 | 814 | unsigned long mark, int classzone_idx); |
a2f3aa02 DH |
815 | enum memmap_context { |
816 | MEMMAP_EARLY, | |
817 | MEMMAP_HOTPLUG, | |
818 | }; | |
dc0bbf3b | 819 | extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn, |
b171e409 | 820 | unsigned long size); |
718127cc | 821 | |
bea8c150 | 822 | extern void lruvec_init(struct lruvec *lruvec); |
7f5e86c2 | 823 | |
599d0c95 | 824 | static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec) |
7f5e86c2 | 825 | { |
c255a458 | 826 | #ifdef CONFIG_MEMCG |
599d0c95 | 827 | return lruvec->pgdat; |
7f5e86c2 | 828 | #else |
599d0c95 | 829 | return container_of(lruvec, struct pglist_data, lruvec); |
7f5e86c2 KK |
830 | #endif |
831 | } | |
832 | ||
fd538803 | 833 | extern unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, int zone_idx); |
23047a96 | 834 | |
1da177e4 LT |
835 | #ifdef CONFIG_HAVE_MEMORY_PRESENT |
836 | void memory_present(int nid, unsigned long start, unsigned long end); | |
837 | #else | |
838 | static inline void memory_present(int nid, unsigned long start, unsigned long end) {} | |
839 | #endif | |
840 | ||
9def36e0 LG |
841 | #if defined(CONFIG_SPARSEMEM) |
842 | void memblocks_present(void); | |
843 | #else | |
844 | static inline void memblocks_present(void) {} | |
845 | #endif | |
846 | ||
7aac7898 LS |
847 | #ifdef CONFIG_HAVE_MEMORYLESS_NODES |
848 | int local_memory_node(int node_id); | |
849 | #else | |
850 | static inline int local_memory_node(int node_id) { return node_id; }; | |
851 | #endif | |
852 | ||
1da177e4 LT |
853 | /* |
854 | * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc. | |
855 | */ | |
856 | #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones) | |
857 | ||
89696701 OS |
858 | #ifdef CONFIG_ZONE_DEVICE |
859 | static inline bool is_dev_zone(const struct zone *zone) | |
860 | { | |
861 | return zone_idx(zone) == ZONE_DEVICE; | |
862 | } | |
863 | #else | |
864 | static inline bool is_dev_zone(const struct zone *zone) | |
865 | { | |
866 | return false; | |
867 | } | |
868 | #endif | |
869 | ||
6aa303de MG |
870 | /* |
871 | * Returns true if a zone has pages managed by the buddy allocator. | |
872 | * All the reclaim decisions have to use this function rather than | |
873 | * populated_zone(). If the whole zone is reserved then we can easily | |
874 | * end up with populated_zone() && !managed_zone(). | |
875 | */ | |
876 | static inline bool managed_zone(struct zone *zone) | |
877 | { | |
9705bea5 | 878 | return zone_managed_pages(zone); |
6aa303de MG |
879 | } |
880 | ||
881 | /* Returns true if a zone has memory */ | |
882 | static inline bool populated_zone(struct zone *zone) | |
f3fe6512 | 883 | { |
6aa303de | 884 | return zone->present_pages; |
f3fe6512 CK |
885 | } |
886 | ||
c1093b74 PT |
887 | #ifdef CONFIG_NUMA |
888 | static inline int zone_to_nid(struct zone *zone) | |
889 | { | |
890 | return zone->node; | |
891 | } | |
892 | ||
893 | static inline void zone_set_nid(struct zone *zone, int nid) | |
894 | { | |
895 | zone->node = nid; | |
896 | } | |
897 | #else | |
898 | static inline int zone_to_nid(struct zone *zone) | |
899 | { | |
900 | return 0; | |
901 | } | |
902 | ||
903 | static inline void zone_set_nid(struct zone *zone, int nid) {} | |
904 | #endif | |
905 | ||
2a1e274a MG |
906 | extern int movable_zone; |
907 | ||
d7e4a2ea | 908 | #ifdef CONFIG_HIGHMEM |
2a1e274a MG |
909 | static inline int zone_movable_is_highmem(void) |
910 | { | |
d7e4a2ea | 911 | #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP |
2a1e274a MG |
912 | return movable_zone == ZONE_HIGHMEM; |
913 | #else | |
d7e4a2ea | 914 | return (ZONE_MOVABLE - 1) == ZONE_HIGHMEM; |
2a1e274a MG |
915 | #endif |
916 | } | |
d7e4a2ea | 917 | #endif |
2a1e274a | 918 | |
2f1b6248 | 919 | static inline int is_highmem_idx(enum zone_type idx) |
1da177e4 | 920 | { |
e53ef38d | 921 | #ifdef CONFIG_HIGHMEM |
2a1e274a MG |
922 | return (idx == ZONE_HIGHMEM || |
923 | (idx == ZONE_MOVABLE && zone_movable_is_highmem())); | |
e53ef38d CL |
924 | #else |
925 | return 0; | |
926 | #endif | |
1da177e4 LT |
927 | } |
928 | ||
1da177e4 | 929 | /** |
b4a991ec | 930 | * is_highmem - helper function to quickly check if a struct zone is a |
1da177e4 LT |
931 | * highmem zone or not. This is an attempt to keep references |
932 | * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum. | |
933 | * @zone - pointer to struct zone variable | |
934 | */ | |
935 | static inline int is_highmem(struct zone *zone) | |
936 | { | |
e53ef38d | 937 | #ifdef CONFIG_HIGHMEM |
29f9cb53 | 938 | return is_highmem_idx(zone_idx(zone)); |
e53ef38d CL |
939 | #else |
940 | return 0; | |
941 | #endif | |
1da177e4 LT |
942 | } |
943 | ||
1da177e4 LT |
944 | /* These two functions are used to setup the per zone pages min values */ |
945 | struct ctl_table; | |
8d65af78 | 946 | int min_free_kbytes_sysctl_handler(struct ctl_table *, int, |
1da177e4 | 947 | void __user *, size_t *, loff_t *); |
1c30844d MG |
948 | int watermark_boost_factor_sysctl_handler(struct ctl_table *, int, |
949 | void __user *, size_t *, loff_t *); | |
795ae7a0 JW |
950 | int watermark_scale_factor_sysctl_handler(struct ctl_table *, int, |
951 | void __user *, size_t *, loff_t *); | |
d3cda233 | 952 | extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES]; |
8d65af78 | 953 | int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, |
1da177e4 | 954 | void __user *, size_t *, loff_t *); |
8d65af78 | 955 | int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, |
8ad4b1fb | 956 | void __user *, size_t *, loff_t *); |
9614634f | 957 | int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int, |
8d65af78 | 958 | void __user *, size_t *, loff_t *); |
0ff38490 | 959 | int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int, |
8d65af78 | 960 | void __user *, size_t *, loff_t *); |
1da177e4 | 961 | |
f0c0b2b8 | 962 | extern int numa_zonelist_order_handler(struct ctl_table *, int, |
8d65af78 | 963 | void __user *, size_t *, loff_t *); |
f0c0b2b8 | 964 | extern char numa_zonelist_order[]; |
c9bff3ee | 965 | #define NUMA_ZONELIST_ORDER_LEN 16 |
f0c0b2b8 | 966 | |
93b7504e | 967 | #ifndef CONFIG_NEED_MULTIPLE_NODES |
1da177e4 LT |
968 | |
969 | extern struct pglist_data contig_page_data; | |
970 | #define NODE_DATA(nid) (&contig_page_data) | |
971 | #define NODE_MEM_MAP(nid) mem_map | |
1da177e4 | 972 | |
93b7504e | 973 | #else /* CONFIG_NEED_MULTIPLE_NODES */ |
1da177e4 LT |
974 | |
975 | #include <asm/mmzone.h> | |
976 | ||
93b7504e | 977 | #endif /* !CONFIG_NEED_MULTIPLE_NODES */ |
348f8b6c | 978 | |
95144c78 KH |
979 | extern struct pglist_data *first_online_pgdat(void); |
980 | extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat); | |
981 | extern struct zone *next_zone(struct zone *zone); | |
8357f869 KH |
982 | |
983 | /** | |
12d15f0d | 984 | * for_each_online_pgdat - helper macro to iterate over all online nodes |
8357f869 KH |
985 | * @pgdat - pointer to a pg_data_t variable |
986 | */ | |
987 | #define for_each_online_pgdat(pgdat) \ | |
988 | for (pgdat = first_online_pgdat(); \ | |
989 | pgdat; \ | |
990 | pgdat = next_online_pgdat(pgdat)) | |
8357f869 KH |
991 | /** |
992 | * for_each_zone - helper macro to iterate over all memory zones | |
993 | * @zone - pointer to struct zone variable | |
994 | * | |
995 | * The user only needs to declare the zone variable, for_each_zone | |
996 | * fills it in. | |
997 | */ | |
998 | #define for_each_zone(zone) \ | |
999 | for (zone = (first_online_pgdat())->node_zones; \ | |
1000 | zone; \ | |
1001 | zone = next_zone(zone)) | |
1002 | ||
ee99c71c KM |
1003 | #define for_each_populated_zone(zone) \ |
1004 | for (zone = (first_online_pgdat())->node_zones; \ | |
1005 | zone; \ | |
1006 | zone = next_zone(zone)) \ | |
1007 | if (!populated_zone(zone)) \ | |
1008 | ; /* do nothing */ \ | |
1009 | else | |
1010 | ||
dd1a239f MG |
1011 | static inline struct zone *zonelist_zone(struct zoneref *zoneref) |
1012 | { | |
1013 | return zoneref->zone; | |
1014 | } | |
1015 | ||
1016 | static inline int zonelist_zone_idx(struct zoneref *zoneref) | |
1017 | { | |
1018 | return zoneref->zone_idx; | |
1019 | } | |
1020 | ||
1021 | static inline int zonelist_node_idx(struct zoneref *zoneref) | |
1022 | { | |
c1093b74 | 1023 | return zone_to_nid(zoneref->zone); |
dd1a239f MG |
1024 | } |
1025 | ||
682a3385 MG |
1026 | struct zoneref *__next_zones_zonelist(struct zoneref *z, |
1027 | enum zone_type highest_zoneidx, | |
1028 | nodemask_t *nodes); | |
1029 | ||
19770b32 MG |
1030 | /** |
1031 | * next_zones_zonelist - Returns the next zone at or below highest_zoneidx within the allowed nodemask using a cursor within a zonelist as a starting point | |
1032 | * @z - The cursor used as a starting point for the search | |
1033 | * @highest_zoneidx - The zone index of the highest zone to return | |
1034 | * @nodes - An optional nodemask to filter the zonelist with | |
19770b32 MG |
1035 | * |
1036 | * This function returns the next zone at or below a given zone index that is | |
1037 | * within the allowed nodemask using a cursor as the starting point for the | |
5bead2a0 MG |
1038 | * search. The zoneref returned is a cursor that represents the current zone |
1039 | * being examined. It should be advanced by one before calling | |
1040 | * next_zones_zonelist again. | |
19770b32 | 1041 | */ |
682a3385 | 1042 | static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z, |
19770b32 | 1043 | enum zone_type highest_zoneidx, |
682a3385 MG |
1044 | nodemask_t *nodes) |
1045 | { | |
1046 | if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx)) | |
1047 | return z; | |
1048 | return __next_zones_zonelist(z, highest_zoneidx, nodes); | |
1049 | } | |
dd1a239f | 1050 | |
19770b32 MG |
1051 | /** |
1052 | * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist | |
1053 | * @zonelist - The zonelist to search for a suitable zone | |
1054 | * @highest_zoneidx - The zone index of the highest zone to return | |
1055 | * @nodes - An optional nodemask to filter the zonelist with | |
ea57485a | 1056 | * @return - Zoneref pointer for the first suitable zone found (see below) |
19770b32 MG |
1057 | * |
1058 | * This function returns the first zone at or below a given zone index that is | |
1059 | * within the allowed nodemask. The zoneref returned is a cursor that can be | |
5bead2a0 MG |
1060 | * used to iterate the zonelist with next_zones_zonelist by advancing it by |
1061 | * one before calling. | |
ea57485a VB |
1062 | * |
1063 | * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is | |
1064 | * never NULL). This may happen either genuinely, or due to concurrent nodemask | |
1065 | * update due to cpuset modification. | |
19770b32 | 1066 | */ |
dd1a239f | 1067 | static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist, |
19770b32 | 1068 | enum zone_type highest_zoneidx, |
c33d6c06 | 1069 | nodemask_t *nodes) |
54a6eb5c | 1070 | { |
c33d6c06 | 1071 | return next_zones_zonelist(zonelist->_zonerefs, |
05891fb0 | 1072 | highest_zoneidx, nodes); |
54a6eb5c MG |
1073 | } |
1074 | ||
19770b32 MG |
1075 | /** |
1076 | * for_each_zone_zonelist_nodemask - helper macro to iterate over valid zones in a zonelist at or below a given zone index and within a nodemask | |
1077 | * @zone - The current zone in the iterator | |
1078 | * @z - The current pointer within zonelist->zones being iterated | |
1079 | * @zlist - The zonelist being iterated | |
1080 | * @highidx - The zone index of the highest zone to return | |
1081 | * @nodemask - Nodemask allowed by the allocator | |
1082 | * | |
1083 | * This iterator iterates though all zones at or below a given zone index and | |
1084 | * within a given nodemask | |
1085 | */ | |
1086 | #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \ | |
c33d6c06 | 1087 | for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \ |
19770b32 | 1088 | zone; \ |
05891fb0 | 1089 | z = next_zones_zonelist(++z, highidx, nodemask), \ |
c33d6c06 MG |
1090 | zone = zonelist_zone(z)) |
1091 | ||
1092 | #define for_next_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \ | |
1093 | for (zone = z->zone; \ | |
1094 | zone; \ | |
1095 | z = next_zones_zonelist(++z, highidx, nodemask), \ | |
1096 | zone = zonelist_zone(z)) | |
1097 | ||
54a6eb5c MG |
1098 | |
1099 | /** | |
1100 | * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index | |
1101 | * @zone - The current zone in the iterator | |
1102 | * @z - The current pointer within zonelist->zones being iterated | |
1103 | * @zlist - The zonelist being iterated | |
1104 | * @highidx - The zone index of the highest zone to return | |
1105 | * | |
1106 | * This iterator iterates though all zones at or below a given zone index. | |
1107 | */ | |
1108 | #define for_each_zone_zonelist(zone, z, zlist, highidx) \ | |
19770b32 | 1109 | for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL) |
54a6eb5c | 1110 | |
d41dee36 AW |
1111 | #ifdef CONFIG_SPARSEMEM |
1112 | #include <asm/sparsemem.h> | |
1113 | #endif | |
1114 | ||
c713216d | 1115 | #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \ |
0ee332c1 | 1116 | !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) |
b4544568 AM |
1117 | static inline unsigned long early_pfn_to_nid(unsigned long pfn) |
1118 | { | |
9d1f4b3f | 1119 | BUILD_BUG_ON(IS_ENABLED(CONFIG_NUMA)); |
b4544568 AM |
1120 | return 0; |
1121 | } | |
b159d43f AW |
1122 | #endif |
1123 | ||
2bdaf115 AW |
1124 | #ifdef CONFIG_FLATMEM |
1125 | #define pfn_to_nid(pfn) (0) | |
1126 | #endif | |
1127 | ||
d41dee36 AW |
1128 | #ifdef CONFIG_SPARSEMEM |
1129 | ||
1130 | /* | |
1131 | * SECTION_SHIFT #bits space required to store a section # | |
1132 | * | |
1133 | * PA_SECTION_SHIFT physical address to/from section number | |
1134 | * PFN_SECTION_SHIFT pfn to/from section number | |
1135 | */ | |
d41dee36 AW |
1136 | #define PA_SECTION_SHIFT (SECTION_SIZE_BITS) |
1137 | #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT) | |
1138 | ||
1139 | #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT) | |
1140 | ||
1141 | #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT) | |
1142 | #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1)) | |
1143 | ||
835c134e | 1144 | #define SECTION_BLOCKFLAGS_BITS \ |
d9c23400 | 1145 | ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS) |
835c134e | 1146 | |
d41dee36 AW |
1147 | #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS |
1148 | #error Allocator MAX_ORDER exceeds SECTION_SIZE | |
1149 | #endif | |
1150 | ||
1dd2bfc8 YI |
1151 | static inline unsigned long pfn_to_section_nr(unsigned long pfn) |
1152 | { | |
1153 | return pfn >> PFN_SECTION_SHIFT; | |
1154 | } | |
1155 | static inline unsigned long section_nr_to_pfn(unsigned long sec) | |
1156 | { | |
1157 | return sec << PFN_SECTION_SHIFT; | |
1158 | } | |
e3c40f37 | 1159 | |
a539f353 DK |
1160 | #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK) |
1161 | #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK) | |
1162 | ||
d41dee36 | 1163 | struct page; |
eefa864b | 1164 | struct page_ext; |
d41dee36 | 1165 | struct mem_section { |
29751f69 AW |
1166 | /* |
1167 | * This is, logically, a pointer to an array of struct | |
1168 | * pages. However, it is stored with some other magic. | |
1169 | * (see sparse.c::sparse_init_one_section()) | |
1170 | * | |
30c253e6 AW |
1171 | * Additionally during early boot we encode node id of |
1172 | * the location of the section here to guide allocation. | |
1173 | * (see sparse.c::memory_present()) | |
1174 | * | |
29751f69 AW |
1175 | * Making it a UL at least makes someone do a cast |
1176 | * before using it wrong. | |
1177 | */ | |
1178 | unsigned long section_mem_map; | |
5c0e3066 MG |
1179 | |
1180 | /* See declaration of similar field in struct zone */ | |
1181 | unsigned long *pageblock_flags; | |
eefa864b JK |
1182 | #ifdef CONFIG_PAGE_EXTENSION |
1183 | /* | |
0c9ad804 | 1184 | * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use |
eefa864b JK |
1185 | * section. (see page_ext.h about this.) |
1186 | */ | |
1187 | struct page_ext *page_ext; | |
1188 | unsigned long pad; | |
1189 | #endif | |
55878e88 CS |
1190 | /* |
1191 | * WARNING: mem_section must be a power-of-2 in size for the | |
1192 | * calculation and use of SECTION_ROOT_MASK to make sense. | |
1193 | */ | |
d41dee36 AW |
1194 | }; |
1195 | ||
3e347261 BP |
1196 | #ifdef CONFIG_SPARSEMEM_EXTREME |
1197 | #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section)) | |
1198 | #else | |
1199 | #define SECTIONS_PER_ROOT 1 | |
1200 | #endif | |
802f192e | 1201 | |
3e347261 | 1202 | #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT) |
0faa5638 | 1203 | #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT) |
3e347261 | 1204 | #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1) |
802f192e | 1205 | |
3e347261 | 1206 | #ifdef CONFIG_SPARSEMEM_EXTREME |
83e3c487 | 1207 | extern struct mem_section **mem_section; |
802f192e | 1208 | #else |
3e347261 BP |
1209 | extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; |
1210 | #endif | |
d41dee36 | 1211 | |
29751f69 AW |
1212 | static inline struct mem_section *__nr_to_section(unsigned long nr) |
1213 | { | |
83e3c487 KS |
1214 | #ifdef CONFIG_SPARSEMEM_EXTREME |
1215 | if (!mem_section) | |
1216 | return NULL; | |
1217 | #endif | |
3e347261 BP |
1218 | if (!mem_section[SECTION_NR_TO_ROOT(nr)]) |
1219 | return NULL; | |
1220 | return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; | |
29751f69 | 1221 | } |
4ca644d9 | 1222 | extern int __section_nr(struct mem_section* ms); |
04753278 | 1223 | extern unsigned long usemap_size(void); |
29751f69 AW |
1224 | |
1225 | /* | |
1226 | * We use the lower bits of the mem_map pointer to store | |
def9b71e PT |
1227 | * a little bit of information. The pointer is calculated |
1228 | * as mem_map - section_nr_to_pfn(pnum). The result is | |
1229 | * aligned to the minimum alignment of the two values: | |
1230 | * 1. All mem_map arrays are page-aligned. | |
1231 | * 2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT | |
1232 | * lowest bits. PFN_SECTION_SHIFT is arch-specific | |
1233 | * (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the | |
1234 | * worst combination is powerpc with 256k pages, | |
1235 | * which results in PFN_SECTION_SHIFT equal 6. | |
1236 | * To sum it up, at least 6 bits are available. | |
29751f69 AW |
1237 | */ |
1238 | #define SECTION_MARKED_PRESENT (1UL<<0) | |
1239 | #define SECTION_HAS_MEM_MAP (1UL<<1) | |
2d070eab MH |
1240 | #define SECTION_IS_ONLINE (1UL<<2) |
1241 | #define SECTION_MAP_LAST_BIT (1UL<<3) | |
29751f69 | 1242 | #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1)) |
2d070eab | 1243 | #define SECTION_NID_SHIFT 3 |
29751f69 AW |
1244 | |
1245 | static inline struct page *__section_mem_map_addr(struct mem_section *section) | |
1246 | { | |
1247 | unsigned long map = section->section_mem_map; | |
1248 | map &= SECTION_MAP_MASK; | |
1249 | return (struct page *)map; | |
1250 | } | |
1251 | ||
540557b9 | 1252 | static inline int present_section(struct mem_section *section) |
29751f69 | 1253 | { |
802f192e | 1254 | return (section && (section->section_mem_map & SECTION_MARKED_PRESENT)); |
29751f69 AW |
1255 | } |
1256 | ||
540557b9 AW |
1257 | static inline int present_section_nr(unsigned long nr) |
1258 | { | |
1259 | return present_section(__nr_to_section(nr)); | |
1260 | } | |
1261 | ||
1262 | static inline int valid_section(struct mem_section *section) | |
29751f69 | 1263 | { |
802f192e | 1264 | return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP)); |
29751f69 AW |
1265 | } |
1266 | ||
1267 | static inline int valid_section_nr(unsigned long nr) | |
1268 | { | |
1269 | return valid_section(__nr_to_section(nr)); | |
1270 | } | |
1271 | ||
2d070eab MH |
1272 | static inline int online_section(struct mem_section *section) |
1273 | { | |
1274 | return (section && (section->section_mem_map & SECTION_IS_ONLINE)); | |
1275 | } | |
1276 | ||
1277 | static inline int online_section_nr(unsigned long nr) | |
1278 | { | |
1279 | return online_section(__nr_to_section(nr)); | |
1280 | } | |
1281 | ||
1282 | #ifdef CONFIG_MEMORY_HOTPLUG | |
1283 | void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn); | |
1284 | #ifdef CONFIG_MEMORY_HOTREMOVE | |
1285 | void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn); | |
1286 | #endif | |
1287 | #endif | |
1288 | ||
d41dee36 AW |
1289 | static inline struct mem_section *__pfn_to_section(unsigned long pfn) |
1290 | { | |
29751f69 | 1291 | return __nr_to_section(pfn_to_section_nr(pfn)); |
d41dee36 AW |
1292 | } |
1293 | ||
c4e1be9e DH |
1294 | extern int __highest_present_section_nr; |
1295 | ||
7b7bf499 | 1296 | #ifndef CONFIG_HAVE_ARCH_PFN_VALID |
d41dee36 AW |
1297 | static inline int pfn_valid(unsigned long pfn) |
1298 | { | |
1299 | if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) | |
1300 | return 0; | |
29751f69 | 1301 | return valid_section(__nr_to_section(pfn_to_section_nr(pfn))); |
d41dee36 | 1302 | } |
7b7bf499 | 1303 | #endif |
d41dee36 | 1304 | |
540557b9 AW |
1305 | static inline int pfn_present(unsigned long pfn) |
1306 | { | |
1307 | if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) | |
1308 | return 0; | |
1309 | return present_section(__nr_to_section(pfn_to_section_nr(pfn))); | |
1310 | } | |
1311 | ||
d41dee36 AW |
1312 | /* |
1313 | * These are _only_ used during initialisation, therefore they | |
1314 | * can use __initdata ... They could have names to indicate | |
1315 | * this restriction. | |
1316 | */ | |
1317 | #ifdef CONFIG_NUMA | |
161599ff AW |
1318 | #define pfn_to_nid(pfn) \ |
1319 | ({ \ | |
1320 | unsigned long __pfn_to_nid_pfn = (pfn); \ | |
1321 | page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \ | |
1322 | }) | |
2bdaf115 AW |
1323 | #else |
1324 | #define pfn_to_nid(pfn) (0) | |
d41dee36 AW |
1325 | #endif |
1326 | ||
d41dee36 AW |
1327 | #define early_pfn_valid(pfn) pfn_valid(pfn) |
1328 | void sparse_init(void); | |
1329 | #else | |
1330 | #define sparse_init() do {} while (0) | |
28ae55c9 | 1331 | #define sparse_index_init(_sec, _nid) do {} while (0) |
e900a918 | 1332 | #define pfn_present pfn_valid |
d41dee36 AW |
1333 | #endif /* CONFIG_SPARSEMEM */ |
1334 | ||
8a942fde MG |
1335 | /* |
1336 | * During memory init memblocks map pfns to nids. The search is expensive and | |
1337 | * this caches recent lookups. The implementation of __early_pfn_to_nid | |
1338 | * may treat start/end as pfns or sections. | |
1339 | */ | |
1340 | struct mminit_pfnnid_cache { | |
1341 | unsigned long last_start; | |
1342 | unsigned long last_end; | |
1343 | int last_nid; | |
1344 | }; | |
1345 | ||
d41dee36 AW |
1346 | #ifndef early_pfn_valid |
1347 | #define early_pfn_valid(pfn) (1) | |
1348 | #endif | |
1349 | ||
1350 | void memory_present(int nid, unsigned long start, unsigned long end); | |
d41dee36 | 1351 | |
14e07298 AW |
1352 | /* |
1353 | * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we | |
8bb4e7a2 | 1354 | * need to check pfn validity within that MAX_ORDER_NR_PAGES block. |
14e07298 AW |
1355 | * pfn_valid_within() should be used in this case; we optimise this away |
1356 | * when we have no holes within a MAX_ORDER_NR_PAGES block. | |
1357 | */ | |
1358 | #ifdef CONFIG_HOLES_IN_ZONE | |
1359 | #define pfn_valid_within(pfn) pfn_valid(pfn) | |
1360 | #else | |
1361 | #define pfn_valid_within(pfn) (1) | |
1362 | #endif | |
1363 | ||
eb33575c MG |
1364 | #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL |
1365 | /* | |
1366 | * pfn_valid() is meant to be able to tell if a given PFN has valid memmap | |
2d070eab MH |
1367 | * associated with it or not. This means that a struct page exists for this |
1368 | * pfn. The caller cannot assume the page is fully initialized in general. | |
1369 | * Hotplugable pages might not have been onlined yet. pfn_to_online_page() | |
1370 | * will ensure the struct page is fully online and initialized. Special pages | |
1371 | * (e.g. ZONE_DEVICE) are never onlined and should be treated accordingly. | |
1372 | * | |
1373 | * In FLATMEM, it is expected that holes always have valid memmap as long as | |
1374 | * there is valid PFNs either side of the hole. In SPARSEMEM, it is assumed | |
1375 | * that a valid section has a memmap for the entire section. | |
eb33575c MG |
1376 | * |
1377 | * However, an ARM, and maybe other embedded architectures in the future | |
1378 | * free memmap backing holes to save memory on the assumption the memmap is | |
1379 | * never used. The page_zone linkages are then broken even though pfn_valid() | |
1380 | * returns true. A walker of the full memmap must then do this additional | |
1381 | * check to ensure the memmap they are looking at is sane by making sure | |
1382 | * the zone and PFN linkages are still valid. This is expensive, but walkers | |
1383 | * of the full memmap are extremely rare. | |
1384 | */ | |
5b80287a | 1385 | bool memmap_valid_within(unsigned long pfn, |
eb33575c MG |
1386 | struct page *page, struct zone *zone); |
1387 | #else | |
5b80287a | 1388 | static inline bool memmap_valid_within(unsigned long pfn, |
eb33575c MG |
1389 | struct page *page, struct zone *zone) |
1390 | { | |
5b80287a | 1391 | return true; |
eb33575c MG |
1392 | } |
1393 | #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */ | |
1394 | ||
97965478 | 1395 | #endif /* !__GENERATING_BOUNDS.H */ |
1da177e4 | 1396 | #endif /* !__ASSEMBLY__ */ |
1da177e4 | 1397 | #endif /* _LINUX_MMZONE_H */ |