1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_MMZONE_H
3 #define _LINUX_MMZONE_H
4
5 #ifndef __ASSEMBLY__
6 #ifndef __GENERATING_BOUNDS_H
7
8 #include <linux/spinlock.h>
9 #include <linux/list.h>
10 #include <linux/list_nulls.h>
11 #include <linux/wait.h>
12 #include <linux/bitops.h>
13 #include <linux/cache.h>
14 #include <linux/threads.h>
15 #include <linux/numa.h>
16 #include <linux/init.h>
17 #include <linux/seqlock.h>
18 #include <linux/nodemask.h>
19 #include <linux/pageblock-flags.h>
20 #include <linux/page-flags-layout.h>
21 #include <linux/atomic.h>
22 #include <linux/mm_types.h>
23 #include <linux/page-flags.h>
24 #include <linux/local_lock.h>
25 #include <asm/page.h>
26
27 /* Free memory management - zoned buddy allocator. */
28 #ifndef CONFIG_ARCH_FORCE_MAX_ORDER
29 #define MAX_ORDER 10
30 #else
31 #define MAX_ORDER CONFIG_ARCH_FORCE_MAX_ORDER
32 #endif
33 #define MAX_ORDER_NR_PAGES (1 << MAX_ORDER)
34
35 #define IS_MAX_ORDER_ALIGNED(pfn) IS_ALIGNED(pfn, MAX_ORDER_NR_PAGES)
36
37 /*
38 * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
39 * costly to service. That is between allocation orders which should
40 * coalesce naturally under reasonable reclaim pressure and those which
41 * will not.
42 */
43 #define PAGE_ALLOC_COSTLY_ORDER 3
44
45 enum migratetype {
46 MIGRATE_UNMOVABLE,
47 MIGRATE_MOVABLE,
48 MIGRATE_RECLAIMABLE,
49 MIGRATE_PCPTYPES, /* the number of types on the pcp lists */
50 MIGRATE_HIGHATOMIC = MIGRATE_PCPTYPES,
51 #ifdef CONFIG_CMA
52 /*
53 * MIGRATE_CMA migration type is designed to mimic the way
54 * ZONE_MOVABLE works. Only movable pages can be allocated
55 * from MIGRATE_CMA pageblocks and page allocator never
56 * implicitly change migration type of MIGRATE_CMA pageblock.
57 *
58 * The way to use it is to change migratetype of a range of
59 * pageblocks to MIGRATE_CMA which can be done by
60 * __free_pageblock_cma() function.
61 */
62 MIGRATE_CMA,
63 #endif
64 #ifdef CONFIG_MEMORY_ISOLATION
65 MIGRATE_ISOLATE, /* can't allocate from here */
66 #endif
67 MIGRATE_TYPES
68 };
69
70 /* In mm/page_alloc.c; keep in sync also with show_migration_types() there */
71 extern const char * const migratetype_names[MIGRATE_TYPES];
72
73 #ifdef CONFIG_CMA
74 # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
75 # define is_migrate_cma_page(_page) (get_pageblock_migratetype(_page) == MIGRATE_CMA)
76 #else
77 # define is_migrate_cma(migratetype) false
78 # define is_migrate_cma_page(_page) false
79 #endif
80
is_migrate_movable(int mt)81 static inline bool is_migrate_movable(int mt)
82 {
83 return is_migrate_cma(mt) || mt == MIGRATE_MOVABLE;
84 }
85
86 /*
87 * Check whether a migratetype can be merged with another migratetype.
88 *
89 * It is only mergeable when it can fall back to other migratetypes for
90 * allocation. See fallbacks[MIGRATE_TYPES][3] in page_alloc.c.
91 */
migratetype_is_mergeable(int mt)92 static inline bool migratetype_is_mergeable(int mt)
93 {
94 return mt < MIGRATE_PCPTYPES;
95 }
96
97 #define for_each_migratetype_order(order, type) \
98 for (order = 0; order <= MAX_ORDER; order++) \
99 for (type = 0; type < MIGRATE_TYPES; type++)
100
101 extern int page_group_by_mobility_disabled;
102
103 #define MIGRATETYPE_MASK ((1UL << PB_migratetype_bits) - 1)
104
105 #define get_pageblock_migratetype(page) \
106 get_pfnblock_flags_mask(page, page_to_pfn(page), MIGRATETYPE_MASK)
107
108 #define folio_migratetype(folio) \
109 get_pfnblock_flags_mask(&folio->page, folio_pfn(folio), \
110 MIGRATETYPE_MASK)
111 struct free_area {
112 struct list_head free_list[MIGRATE_TYPES];
113 unsigned long nr_free;
114 };
115
116 struct pglist_data;
117
118 #ifdef CONFIG_NUMA
119 enum numa_stat_item {
120 NUMA_HIT, /* allocated in intended node */
121 NUMA_MISS, /* allocated in non intended node */
122 NUMA_FOREIGN, /* was intended here, hit elsewhere */
123 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
124 NUMA_LOCAL, /* allocation from local node */
125 NUMA_OTHER, /* allocation from other node */
126 NR_VM_NUMA_EVENT_ITEMS
127 };
128 #else
129 #define NR_VM_NUMA_EVENT_ITEMS 0
130 #endif
131
132 enum zone_stat_item {
133 /* First 128 byte cacheline (assuming 64 bit words) */
134 NR_FREE_PAGES,
135 NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */
136 NR_ZONE_INACTIVE_ANON = NR_ZONE_LRU_BASE,
137 NR_ZONE_ACTIVE_ANON,
138 NR_ZONE_INACTIVE_FILE,
139 NR_ZONE_ACTIVE_FILE,
140 NR_ZONE_UNEVICTABLE,
141 NR_ZONE_WRITE_PENDING, /* Count of dirty, writeback and unstable pages */
142 NR_MLOCK, /* mlock()ed pages found and moved off LRU */
143 /* Second 128 byte cacheline */
144 NR_BOUNCE,
145 #if IS_ENABLED(CONFIG_ZSMALLOC)
146 NR_ZSPAGES, /* allocated in zsmalloc */
147 #endif
148 NR_FREE_CMA_PAGES,
149 #ifdef CONFIG_UNACCEPTED_MEMORY
150 NR_UNACCEPTED,
151 #endif
152 NR_VM_ZONE_STAT_ITEMS };
153
154 enum node_stat_item {
155 NR_LRU_BASE,
156 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
157 NR_ACTIVE_ANON, /* " " " " " */
158 NR_INACTIVE_FILE, /* " " " " " */
159 NR_ACTIVE_FILE, /* " " " " " */
160 NR_UNEVICTABLE, /* " " " " " */
161 NR_SLAB_RECLAIMABLE_B,
162 NR_SLAB_UNRECLAIMABLE_B,
163 NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */
164 NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
165 WORKINGSET_NODES,
166 WORKINGSET_REFAULT_BASE,
167 WORKINGSET_REFAULT_ANON = WORKINGSET_REFAULT_BASE,
168 WORKINGSET_REFAULT_FILE,
169 WORKINGSET_ACTIVATE_BASE,
170 WORKINGSET_ACTIVATE_ANON = WORKINGSET_ACTIVATE_BASE,
171 WORKINGSET_ACTIVATE_FILE,
172 WORKINGSET_RESTORE_BASE,
173 WORKINGSET_RESTORE_ANON = WORKINGSET_RESTORE_BASE,
174 WORKINGSET_RESTORE_FILE,
175 WORKINGSET_NODERECLAIM,
176 NR_ANON_MAPPED, /* Mapped anonymous pages */
177 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
178 only modified from process context */
179 NR_FILE_PAGES,
180 NR_FILE_DIRTY,
181 NR_WRITEBACK,
182 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
183 NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */
184 NR_SHMEM_THPS,
185 NR_SHMEM_PMDMAPPED,
186 NR_FILE_THPS,
187 NR_FILE_PMDMAPPED,
188 NR_ANON_THPS,
189 NR_VMSCAN_WRITE,
190 NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */
191 NR_DIRTIED, /* page dirtyings since bootup */
192 NR_WRITTEN, /* page writings since bootup */
193 NR_THROTTLED_WRITTEN, /* NR_WRITTEN while reclaim throttled */
194 NR_KERNEL_MISC_RECLAIMABLE, /* reclaimable non-slab kernel pages */
195 NR_FOLL_PIN_ACQUIRED, /* via: pin_user_page(), gup flag: FOLL_PIN */
196 NR_FOLL_PIN_RELEASED, /* pages returned via unpin_user_page() */
197 NR_KERNEL_STACK_KB, /* measured in KiB */
198 #if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
199 NR_KERNEL_SCS_KB, /* measured in KiB */
200 #endif
201 NR_PAGETABLE, /* used for pagetables */
202 NR_SECONDARY_PAGETABLE, /* secondary pagetables, e.g. KVM pagetables */
203 #ifdef CONFIG_SWAP
204 NR_SWAPCACHE,
205 #endif
206 #ifdef CONFIG_NUMA_BALANCING
207 PGPROMOTE_SUCCESS, /* promote successfully */
208 PGPROMOTE_CANDIDATE, /* candidate pages to promote */
209 #endif
210 NR_VM_NODE_STAT_ITEMS
211 };
212
213 /*
214 * Returns true if the item should be printed in THPs (/proc/vmstat
215 * currently prints number of anon, file and shmem THPs. But the item
216 * is charged in pages).
217 */
vmstat_item_print_in_thp(enum node_stat_item item)218 static __always_inline bool vmstat_item_print_in_thp(enum node_stat_item item)
219 {
220 if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
221 return false;
222
223 return item == NR_ANON_THPS ||
224 item == NR_FILE_THPS ||
225 item == NR_SHMEM_THPS ||
226 item == NR_SHMEM_PMDMAPPED ||
227 item == NR_FILE_PMDMAPPED;
228 }
229
230 /*
231 * Returns true if the value is measured in bytes (most vmstat values are
232 * measured in pages). This defines the API part, the internal representation
233 * might be different.
234 */
vmstat_item_in_bytes(int idx)235 static __always_inline bool vmstat_item_in_bytes(int idx)
236 {
237 /*
238 * Global and per-node slab counters track slab pages.
239 * It's expected that changes are multiples of PAGE_SIZE.
240 * Internally values are stored in pages.
241 *
242 * Per-memcg and per-lruvec counters track memory, consumed
243 * by individual slab objects. These counters are actually
244 * byte-precise.
245 */
246 return (idx == NR_SLAB_RECLAIMABLE_B ||
247 idx == NR_SLAB_UNRECLAIMABLE_B);
248 }
249
250 /*
251 * We do arithmetic on the LRU lists in various places in the code,
252 * so it is important to keep the active lists LRU_ACTIVE higher in
253 * the array than the corresponding inactive lists, and to keep
254 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
255 *
256 * This has to be kept in sync with the statistics in zone_stat_item
257 * above and the descriptions in vmstat_text in mm/vmstat.c
258 */
259 #define LRU_BASE 0
260 #define LRU_ACTIVE 1
261 #define LRU_FILE 2
262
263 enum lru_list {
264 LRU_INACTIVE_ANON = LRU_BASE,
265 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
266 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
267 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
268 LRU_UNEVICTABLE,
269 NR_LRU_LISTS
270 };
271
272 enum vmscan_throttle_state {
273 VMSCAN_THROTTLE_WRITEBACK,
274 VMSCAN_THROTTLE_ISOLATED,
275 VMSCAN_THROTTLE_NOPROGRESS,
276 VMSCAN_THROTTLE_CONGESTED,
277 NR_VMSCAN_THROTTLE,
278 };
279
280 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++)
281
282 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++)
283
is_file_lru(enum lru_list lru)284 static inline bool is_file_lru(enum lru_list lru)
285 {
286 return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE);
287 }
288
is_active_lru(enum lru_list lru)289 static inline bool is_active_lru(enum lru_list lru)
290 {
291 return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE);
292 }
293
294 #define WORKINGSET_ANON 0
295 #define WORKINGSET_FILE 1
296 #define ANON_AND_FILE 2
297
298 enum lruvec_flags {
299 /*
300 * An lruvec has many dirty pages backed by a congested BDI:
301 * 1. LRUVEC_CGROUP_CONGESTED is set by cgroup-level reclaim.
302 * It can be cleared by cgroup reclaim or kswapd.
303 * 2. LRUVEC_NODE_CONGESTED is set by kswapd node-level reclaim.
304 * It can only be cleared by kswapd.
305 *
306 * Essentially, kswapd can unthrottle an lruvec throttled by cgroup
307 * reclaim, but not vice versa. This only applies to the root cgroup.
308 * The goal is to prevent cgroup reclaim on the root cgroup (e.g.
309 * memory.reclaim) to unthrottle an unbalanced node (that was throttled
310 * by kswapd).
311 */
312 LRUVEC_CGROUP_CONGESTED,
313 LRUVEC_NODE_CONGESTED,
314 };
315
316 #endif /* !__GENERATING_BOUNDS_H */
317
318 /*
319 * Evictable pages are divided into multiple generations. The youngest and the
320 * oldest generation numbers, max_seq and min_seq, are monotonically increasing.
321 * They form a sliding window of a variable size [MIN_NR_GENS, MAX_NR_GENS]. An
322 * offset within MAX_NR_GENS, i.e., gen, indexes the LRU list of the
323 * corresponding generation. The gen counter in folio->flags stores gen+1 while
324 * a page is on one of lrugen->folios[]. Otherwise it stores 0.
325 *
326 * A page is added to the youngest generation on faulting. The aging needs to
327 * check the accessed bit at least twice before handing this page over to the
328 * eviction. The first check takes care of the accessed bit set on the initial
329 * fault; the second check makes sure this page hasn't been used since then.
330 * This process, AKA second chance, requires a minimum of two generations,
331 * hence MIN_NR_GENS. And to maintain ABI compatibility with the active/inactive
332 * LRU, e.g., /proc/vmstat, these two generations are considered active; the
333 * rest of generations, if they exist, are considered inactive. See
334 * lru_gen_is_active().
335 *
336 * PG_active is always cleared while a page is on one of lrugen->folios[] so
337 * that the aging needs not to worry about it. And it's set again when a page
338 * considered active is isolated for non-reclaiming purposes, e.g., migration.
339 * See lru_gen_add_folio() and lru_gen_del_folio().
340 *
341 * MAX_NR_GENS is set to 4 so that the multi-gen LRU can support twice the
342 * number of categories of the active/inactive LRU when keeping track of
343 * accesses through page tables. This requires order_base_2(MAX_NR_GENS+1) bits
344 * in folio->flags.
345 */
346 #define MIN_NR_GENS 2U
347 #define MAX_NR_GENS 4U
348
349 /*
350 * Each generation is divided into multiple tiers. A page accessed N times
351 * through file descriptors is in tier order_base_2(N). A page in the first tier
352 * (N=0,1) is marked by PG_referenced unless it was faulted in through page
353 * tables or read ahead. A page in any other tier (N>1) is marked by
354 * PG_referenced and PG_workingset. This implies a minimum of two tiers is
355 * supported without using additional bits in folio->flags.
356 *
357 * In contrast to moving across generations which requires the LRU lock, moving
358 * across tiers only involves atomic operations on folio->flags and therefore
359 * has a negligible cost in the buffered access path. In the eviction path,
360 * comparisons of refaulted/(evicted+protected) from the first tier and the
361 * rest infer whether pages accessed multiple times through file descriptors
362 * are statistically hot and thus worth protecting.
363 *
364 * MAX_NR_TIERS is set to 4 so that the multi-gen LRU can support twice the
365 * number of categories of the active/inactive LRU when keeping track of
366 * accesses through file descriptors. This uses MAX_NR_TIERS-2 spare bits in
367 * folio->flags.
368 */
369 #define MAX_NR_TIERS 4U
370
371 #ifndef __GENERATING_BOUNDS_H
372
373 struct lruvec;
374 struct page_vma_mapped_walk;
375
376 #define LRU_GEN_MASK ((BIT(LRU_GEN_WIDTH) - 1) << LRU_GEN_PGOFF)
377 #define LRU_REFS_MASK ((BIT(LRU_REFS_WIDTH) - 1) << LRU_REFS_PGOFF)
378
379 #ifdef CONFIG_LRU_GEN
380
381 enum {
382 LRU_GEN_ANON,
383 LRU_GEN_FILE,
384 };
385
386 enum {
387 LRU_GEN_CORE,
388 LRU_GEN_MM_WALK,
389 LRU_GEN_NONLEAF_YOUNG,
390 NR_LRU_GEN_CAPS
391 };
392
393 #define MIN_LRU_BATCH BITS_PER_LONG
394 #define MAX_LRU_BATCH (MIN_LRU_BATCH * 64)
395
396 /* whether to keep historical stats from evicted generations */
397 #ifdef CONFIG_LRU_GEN_STATS
398 #define NR_HIST_GENS MAX_NR_GENS
399 #else
400 #define NR_HIST_GENS 1U
401 #endif
402
403 /*
404 * The youngest generation number is stored in max_seq for both anon and file
405 * types as they are aged on an equal footing. The oldest generation numbers are
406 * stored in min_seq[] separately for anon and file types as clean file pages
407 * can be evicted regardless of swap constraints.
408 *
409 * Normally anon and file min_seq are in sync. But if swapping is constrained,
410 * e.g., out of swap space, file min_seq is allowed to advance and leave anon
411 * min_seq behind.
412 *
413 * The number of pages in each generation is eventually consistent and therefore
414 * can be transiently negative when reset_batch_size() is pending.
415 */
416 struct lru_gen_folio {
417 /* the aging increments the youngest generation number */
418 unsigned long max_seq;
419 /* the eviction increments the oldest generation numbers */
420 unsigned long min_seq[ANON_AND_FILE];
421 /* the birth time of each generation in jiffies */
422 unsigned long timestamps[MAX_NR_GENS];
423 /* the multi-gen LRU lists, lazily sorted on eviction */
424 struct list_head folios[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES];
425 /* the multi-gen LRU sizes, eventually consistent */
426 long nr_pages[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES];
427 /* the exponential moving average of refaulted */
428 unsigned long avg_refaulted[ANON_AND_FILE][MAX_NR_TIERS];
429 /* the exponential moving average of evicted+protected */
430 unsigned long avg_total[ANON_AND_FILE][MAX_NR_TIERS];
431 /* the first tier doesn't need protection, hence the minus one */
432 unsigned long protected[NR_HIST_GENS][ANON_AND_FILE][MAX_NR_TIERS - 1];
433 /* can be modified without holding the LRU lock */
434 atomic_long_t evicted[NR_HIST_GENS][ANON_AND_FILE][MAX_NR_TIERS];
435 atomic_long_t refaulted[NR_HIST_GENS][ANON_AND_FILE][MAX_NR_TIERS];
436 /* whether the multi-gen LRU is enabled */
437 bool enabled;
438 #ifdef CONFIG_MEMCG
439 /* the memcg generation this lru_gen_folio belongs to */
440 u8 gen;
441 /* the list segment this lru_gen_folio belongs to */
442 u8 seg;
443 /* per-node lru_gen_folio list for global reclaim */
444 struct hlist_nulls_node list;
445 #endif
446 };
447
448 enum {
449 MM_LEAF_TOTAL, /* total leaf entries */
450 MM_LEAF_OLD, /* old leaf entries */
451 MM_LEAF_YOUNG, /* young leaf entries */
452 MM_NONLEAF_TOTAL, /* total non-leaf entries */
453 MM_NONLEAF_FOUND, /* non-leaf entries found in Bloom filters */
454 MM_NONLEAF_ADDED, /* non-leaf entries added to Bloom filters */
455 NR_MM_STATS
456 };
457
458 /* double-buffering Bloom filters */
459 #define NR_BLOOM_FILTERS 2
460
461 struct lru_gen_mm_state {
462 /* set to max_seq after each iteration */
463 unsigned long seq;
464 /* where the current iteration continues after */
465 struct list_head *head;
466 /* where the last iteration ended before */
467 struct list_head *tail;
468 /* Bloom filters flip after each iteration */
469 unsigned long *filters[NR_BLOOM_FILTERS];
470 /* the mm stats for debugging */
471 unsigned long stats[NR_HIST_GENS][NR_MM_STATS];
472 };
473
474 struct lru_gen_mm_walk {
475 /* the lruvec under reclaim */
476 struct lruvec *lruvec;
477 /* unstable max_seq from lru_gen_folio */
478 unsigned long max_seq;
479 /* the next address within an mm to scan */
480 unsigned long next_addr;
481 /* to batch promoted pages */
482 int nr_pages[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES];
483 /* to batch the mm stats */
484 int mm_stats[NR_MM_STATS];
485 /* total batched items */
486 int batched;
487 bool can_swap;
488 bool force_scan;
489 };
490
491 void lru_gen_init_lruvec(struct lruvec *lruvec);
492 void lru_gen_look_around(struct page_vma_mapped_walk *pvmw);
493
494 #ifdef CONFIG_MEMCG
495
496 /*
497 * For each node, memcgs are divided into two generations: the old and the
498 * young. For each generation, memcgs are randomly sharded into multiple bins
499 * to improve scalability. For each bin, the hlist_nulls is virtually divided
500 * into three segments: the head, the tail and the default.
501 *
502 * An onlining memcg is added to the tail of a random bin in the old generation.
503 * The eviction starts at the head of a random bin in the old generation. The
504 * per-node memcg generation counter, whose reminder (mod MEMCG_NR_GENS) indexes
505 * the old generation, is incremented when all its bins become empty.
506 *
507 * There are four operations:
508 * 1. MEMCG_LRU_HEAD, which moves a memcg to the head of a random bin in its
509 * current generation (old or young) and updates its "seg" to "head";
510 * 2. MEMCG_LRU_TAIL, which moves a memcg to the tail of a random bin in its
511 * current generation (old or young) and updates its "seg" to "tail";
512 * 3. MEMCG_LRU_OLD, which moves a memcg to the head of a random bin in the old
513 * generation, updates its "gen" to "old" and resets its "seg" to "default";
514 * 4. MEMCG_LRU_YOUNG, which moves a memcg to the tail of a random bin in the
515 * young generation, updates its "gen" to "young" and resets its "seg" to
516 * "default".
517 *
518 * The events that trigger the above operations are:
519 * 1. Exceeding the soft limit, which triggers MEMCG_LRU_HEAD;
520 * 2. The first attempt to reclaim a memcg below low, which triggers
521 * MEMCG_LRU_TAIL;
522 * 3. The first attempt to reclaim a memcg offlined or below reclaimable size
523 * threshold, which triggers MEMCG_LRU_TAIL;
524 * 4. The second attempt to reclaim a memcg offlined or below reclaimable size
525 * threshold, which triggers MEMCG_LRU_YOUNG;
526 * 5. Attempting to reclaim a memcg below min, which triggers MEMCG_LRU_YOUNG;
527 * 6. Finishing the aging on the eviction path, which triggers MEMCG_LRU_YOUNG;
528 * 7. Offlining a memcg, which triggers MEMCG_LRU_OLD.
529 *
530 * Notes:
531 * 1. Memcg LRU only applies to global reclaim, and the round-robin incrementing
532 * of their max_seq counters ensures the eventual fairness to all eligible
533 * memcgs. For memcg reclaim, it still relies on mem_cgroup_iter().
534 * 2. There are only two valid generations: old (seq) and young (seq+1).
535 * MEMCG_NR_GENS is set to three so that when reading the generation counter
536 * locklessly, a stale value (seq-1) does not wraparound to young.
537 */
538 #define MEMCG_NR_GENS 3
539 #define MEMCG_NR_BINS 8
540
541 struct lru_gen_memcg {
542 /* the per-node memcg generation counter */
543 unsigned long seq;
544 /* each memcg has one lru_gen_folio per node */
545 unsigned long nr_memcgs[MEMCG_NR_GENS];
546 /* per-node lru_gen_folio list for global reclaim */
547 struct hlist_nulls_head fifo[MEMCG_NR_GENS][MEMCG_NR_BINS];
548 /* protects the above */
549 spinlock_t lock;
550 };
551
552 void lru_gen_init_pgdat(struct pglist_data *pgdat);
553
554 void lru_gen_init_memcg(struct mem_cgroup *memcg);
555 void lru_gen_exit_memcg(struct mem_cgroup *memcg);
556 void lru_gen_online_memcg(struct mem_cgroup *memcg);
557 void lru_gen_offline_memcg(struct mem_cgroup *memcg);
558 void lru_gen_release_memcg(struct mem_cgroup *memcg);
559 void lru_gen_soft_reclaim(struct mem_cgroup *memcg, int nid);
560
561 #else /* !CONFIG_MEMCG */
562
563 #define MEMCG_NR_GENS 1
564
565 struct lru_gen_memcg {
566 };
567
lru_gen_init_pgdat(struct pglist_data * pgdat)568 static inline void lru_gen_init_pgdat(struct pglist_data *pgdat)
569 {
570 }
571
572 #endif /* CONFIG_MEMCG */
573
574 #else /* !CONFIG_LRU_GEN */
575
lru_gen_init_pgdat(struct pglist_data * pgdat)576 static inline void lru_gen_init_pgdat(struct pglist_data *pgdat)
577 {
578 }
579
lru_gen_init_lruvec(struct lruvec * lruvec)580 static inline void lru_gen_init_lruvec(struct lruvec *lruvec)
581 {
582 }
583
lru_gen_look_around(struct page_vma_mapped_walk * pvmw)584 static inline void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
585 {
586 }
587
588 #ifdef CONFIG_MEMCG
589
lru_gen_init_memcg(struct mem_cgroup * memcg)590 static inline void lru_gen_init_memcg(struct mem_cgroup *memcg)
591 {
592 }
593
lru_gen_exit_memcg(struct mem_cgroup * memcg)594 static inline void lru_gen_exit_memcg(struct mem_cgroup *memcg)
595 {
596 }
597
lru_gen_online_memcg(struct mem_cgroup * memcg)598 static inline void lru_gen_online_memcg(struct mem_cgroup *memcg)
599 {
600 }
601
lru_gen_offline_memcg(struct mem_cgroup * memcg)602 static inline void lru_gen_offline_memcg(struct mem_cgroup *memcg)
603 {
604 }
605
lru_gen_release_memcg(struct mem_cgroup * memcg)606 static inline void lru_gen_release_memcg(struct mem_cgroup *memcg)
607 {
608 }
609
lru_gen_soft_reclaim(struct mem_cgroup * memcg,int nid)610 static inline void lru_gen_soft_reclaim(struct mem_cgroup *memcg, int nid)
611 {
612 }
613
614 #endif /* CONFIG_MEMCG */
615
616 #endif /* CONFIG_LRU_GEN */
617
618 struct lruvec {
619 struct list_head lists[NR_LRU_LISTS];
620 /* per lruvec lru_lock for memcg */
621 spinlock_t lru_lock;
622 /*
623 * These track the cost of reclaiming one LRU - file or anon -
624 * over the other. As the observed cost of reclaiming one LRU
625 * increases, the reclaim scan balance tips toward the other.
626 */
627 unsigned long anon_cost;
628 unsigned long file_cost;
629 /* Non-resident age, driven by LRU movement */
630 atomic_long_t nonresident_age;
631 /* Refaults at the time of last reclaim cycle */
632 unsigned long refaults[ANON_AND_FILE];
633 /* Various lruvec state flags (enum lruvec_flags) */
634 unsigned long flags;
635 #ifdef CONFIG_LRU_GEN
636 /* evictable pages divided into generations */
637 struct lru_gen_folio lrugen;
638 /* to concurrently iterate lru_gen_mm_list */
639 struct lru_gen_mm_state mm_state;
640 #endif
641 #ifdef CONFIG_MEMCG
642 struct pglist_data *pgdat;
643 #endif
644 };
645
646 /* Isolate unmapped pages */
647 #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2)
648 /* Isolate for asynchronous migration */
649 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4)
650 /* Isolate unevictable pages */
651 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8)
652
653 /* LRU Isolation modes. */
654 typedef unsigned __bitwise isolate_mode_t;
655
656 enum zone_watermarks {
657 WMARK_MIN,
658 WMARK_LOW,
659 WMARK_HIGH,
660 WMARK_PROMO,
661 NR_WMARK
662 };
663
664 /*
665 * One per migratetype for each PAGE_ALLOC_COSTLY_ORDER. One additional list
666 * for THP which will usually be GFP_MOVABLE. Even if it is another type,
667 * it should not contribute to serious fragmentation causing THP allocation
668 * failures.
669 */
670 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
671 #define NR_PCP_THP 1
672 #else
673 #define NR_PCP_THP 0
674 #endif
675 #define NR_LOWORDER_PCP_LISTS (MIGRATE_PCPTYPES * (PAGE_ALLOC_COSTLY_ORDER + 1))
676 #define NR_PCP_LISTS (NR_LOWORDER_PCP_LISTS + NR_PCP_THP)
677
678 #define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost)
679 #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost)
680 #define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost)
681 #define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost)
682
683 struct per_cpu_pages {
684 spinlock_t lock; /* Protects lists field */
685 int count; /* number of pages in the list */
686 int high; /* high watermark, emptying needed */
687 int batch; /* chunk size for buddy add/remove */
688 short free_factor; /* batch scaling factor during free */
689 #ifdef CONFIG_NUMA
690 short expire; /* When 0, remote pagesets are drained */
691 #endif
692
693 /* Lists of pages, one per migrate type stored on the pcp-lists */
694 struct list_head lists[NR_PCP_LISTS];
695 } ____cacheline_aligned_in_smp;
696
697 struct per_cpu_zonestat {
698 #ifdef CONFIG_SMP
699 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
700 s8 stat_threshold;
701 #endif
702 #ifdef CONFIG_NUMA
703 /*
704 * Low priority inaccurate counters that are only folded
705 * on demand. Use a large type to avoid the overhead of
706 * folding during refresh_cpu_vm_stats.
707 */
708 unsigned long vm_numa_event[NR_VM_NUMA_EVENT_ITEMS];
709 #endif
710 };
711
712 struct per_cpu_nodestat {
713 s8 stat_threshold;
714 s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS];
715 };
716
717 #endif /* !__GENERATING_BOUNDS.H */
718
719 enum zone_type {
720 /*
721 * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able
722 * to DMA to all of the addressable memory (ZONE_NORMAL).
723 * On architectures where this area covers the whole 32 bit address
724 * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller
725 * DMA addressing constraints. This distinction is important as a 32bit
726 * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit
727 * platforms may need both zones as they support peripherals with
728 * different DMA addressing limitations.
729 */
730 #ifdef CONFIG_ZONE_DMA
731 ZONE_DMA,
732 #endif
733 #ifdef CONFIG_ZONE_DMA32
734 ZONE_DMA32,
735 #endif
736 /*
737 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
738 * performed on pages in ZONE_NORMAL if the DMA devices support
739 * transfers to all addressable memory.
740 */
741 ZONE_NORMAL,
742 #ifdef CONFIG_HIGHMEM
743 /*
744 * A memory area that is only addressable by the kernel through
745 * mapping portions into its own address space. This is for example
746 * used by i386 to allow the kernel to address the memory beyond
747 * 900MB. The kernel will set up special mappings (page
748 * table entries on i386) for each page that the kernel needs to
749 * access.
750 */
751 ZONE_HIGHMEM,
752 #endif
753 /*
754 * ZONE_MOVABLE is similar to ZONE_NORMAL, except that it contains
755 * movable pages with few exceptional cases described below. Main use
756 * cases for ZONE_MOVABLE are to make memory offlining/unplug more
757 * likely to succeed, and to locally limit unmovable allocations - e.g.,
758 * to increase the number of THP/huge pages. Notable special cases are:
759 *
760 * 1. Pinned pages: (long-term) pinning of movable pages might
761 * essentially turn such pages unmovable. Therefore, we do not allow
762 * pinning long-term pages in ZONE_MOVABLE. When pages are pinned and
763 * faulted, they come from the right zone right away. However, it is
764 * still possible that address space already has pages in
765 * ZONE_MOVABLE at the time when pages are pinned (i.e. user has
766 * touches that memory before pinning). In such case we migrate them
767 * to a different zone. When migration fails - pinning fails.
768 * 2. memblock allocations: kernelcore/movablecore setups might create
769 * situations where ZONE_MOVABLE contains unmovable allocations
770 * after boot. Memory offlining and allocations fail early.
771 * 3. Memory holes: kernelcore/movablecore setups might create very rare
772 * situations where ZONE_MOVABLE contains memory holes after boot,
773 * for example, if we have sections that are only partially
774 * populated. Memory offlining and allocations fail early.
775 * 4. PG_hwpoison pages: while poisoned pages can be skipped during
776 * memory offlining, such pages cannot be allocated.
777 * 5. Unmovable PG_offline pages: in paravirtualized environments,
778 * hotplugged memory blocks might only partially be managed by the
779 * buddy (e.g., via XEN-balloon, Hyper-V balloon, virtio-mem). The
780 * parts not manged by the buddy are unmovable PG_offline pages. In
781 * some cases (virtio-mem), such pages can be skipped during
782 * memory offlining, however, cannot be moved/allocated. These
783 * techniques might use alloc_contig_range() to hide previously
784 * exposed pages from the buddy again (e.g., to implement some sort
785 * of memory unplug in virtio-mem).
786 * 6. ZERO_PAGE(0), kernelcore/movablecore setups might create
787 * situations where ZERO_PAGE(0) which is allocated differently
788 * on different platforms may end up in a movable zone. ZERO_PAGE(0)
789 * cannot be migrated.
790 * 7. Memory-hotplug: when using memmap_on_memory and onlining the
791 * memory to the MOVABLE zone, the vmemmap pages are also placed in
792 * such zone. Such pages cannot be really moved around as they are
793 * self-stored in the range, but they are treated as movable when
794 * the range they describe is about to be offlined.
795 *
796 * In general, no unmovable allocations that degrade memory offlining
797 * should end up in ZONE_MOVABLE. Allocators (like alloc_contig_range())
798 * have to expect that migrating pages in ZONE_MOVABLE can fail (even
799 * if has_unmovable_pages() states that there are no unmovable pages,
800 * there can be false negatives).
801 */
802 ZONE_MOVABLE,
803 #ifdef CONFIG_ZONE_DEVICE
804 ZONE_DEVICE,
805 #endif
806 __MAX_NR_ZONES
807
808 };
809
810 #ifndef __GENERATING_BOUNDS_H
811
812 #define ASYNC_AND_SYNC 2
813
814 struct zone {
815 /* Read-mostly fields */
816
817 /* zone watermarks, access with *_wmark_pages(zone) macros */
818 unsigned long _watermark[NR_WMARK];
819 unsigned long watermark_boost;
820
821 unsigned long nr_reserved_highatomic;
822
823 /*
824 * We don't know if the memory that we're going to allocate will be
825 * freeable or/and it will be released eventually, so to avoid totally
826 * wasting several GB of ram we must reserve some of the lower zone
827 * memory (otherwise we risk to run OOM on the lower zones despite
828 * there being tons of freeable ram on the higher zones). This array is
829 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl
830 * changes.
831 */
832 long lowmem_reserve[MAX_NR_ZONES];
833
834 #ifdef CONFIG_NUMA
835 int node;
836 #endif
837 struct pglist_data *zone_pgdat;
838 struct per_cpu_pages __percpu *per_cpu_pageset;
839 struct per_cpu_zonestat __percpu *per_cpu_zonestats;
840 /*
841 * the high and batch values are copied to individual pagesets for
842 * faster access
843 */
844 int pageset_high;
845 int pageset_batch;
846
847 #ifndef CONFIG_SPARSEMEM
848 /*
849 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
850 * In SPARSEMEM, this map is stored in struct mem_section
851 */
852 unsigned long *pageblock_flags;
853 #endif /* CONFIG_SPARSEMEM */
854
855 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
856 unsigned long zone_start_pfn;
857
858 /*
859 * spanned_pages is the total pages spanned by the zone, including
860 * holes, which is calculated as:
861 * spanned_pages = zone_end_pfn - zone_start_pfn;
862 *
863 * present_pages is physical pages existing within the zone, which
864 * is calculated as:
865 * present_pages = spanned_pages - absent_pages(pages in holes);
866 *
867 * present_early_pages is present pages existing within the zone
868 * located on memory available since early boot, excluding hotplugged
869 * memory.
870 *
871 * managed_pages is present pages managed by the buddy system, which
872 * is calculated as (reserved_pages includes pages allocated by the
873 * bootmem allocator):
874 * managed_pages = present_pages - reserved_pages;
875 *
876 * cma pages is present pages that are assigned for CMA use
877 * (MIGRATE_CMA).
878 *
879 * So present_pages may be used by memory hotplug or memory power
880 * management logic to figure out unmanaged pages by checking
881 * (present_pages - managed_pages). And managed_pages should be used
882 * by page allocator and vm scanner to calculate all kinds of watermarks
883 * and thresholds.
884 *
885 * Locking rules:
886 *
887 * zone_start_pfn and spanned_pages are protected by span_seqlock.
888 * It is a seqlock because it has to be read outside of zone->lock,
889 * and it is done in the main allocator path. But, it is written
890 * quite infrequently.
891 *
892 * The span_seq lock is declared along with zone->lock because it is
893 * frequently read in proximity to zone->lock. It's good to
894 * give them a chance of being in the same cacheline.
895 *
896 * Write access to present_pages at runtime should be protected by
897 * mem_hotplug_begin/done(). Any reader who can't tolerant drift of
898 * present_pages should use get_online_mems() to get a stable value.
899 */
900 atomic_long_t managed_pages;
901 unsigned long spanned_pages;
902 unsigned long present_pages;
903 #if defined(CONFIG_MEMORY_HOTPLUG)
904 unsigned long present_early_pages;
905 #endif
906 #ifdef CONFIG_CMA
907 unsigned long cma_pages;
908 #endif
909
910 const char *name;
911
912 #ifdef CONFIG_MEMORY_ISOLATION
913 /*
914 * Number of isolated pageblock. It is used to solve incorrect
915 * freepage counting problem due to racy retrieving migratetype
916 * of pageblock. Protected by zone->lock.
917 */
918 unsigned long nr_isolate_pageblock;
919 #endif
920
921 #ifdef CONFIG_MEMORY_HOTPLUG
922 /* see spanned/present_pages for more description */
923 seqlock_t span_seqlock;
924 #endif
925
926 int initialized;
927
928 /* Write-intensive fields used from the page allocator */
929 CACHELINE_PADDING(_pad1_);
930
931 /* free areas of different sizes */
932 struct free_area free_area[MAX_ORDER + 1];
933
934 #ifdef CONFIG_UNACCEPTED_MEMORY
935 /* Pages to be accepted. All pages on the list are MAX_ORDER */
936 struct list_head unaccepted_pages;
937 #endif
938
939 /* zone flags, see below */
940 unsigned long flags;
941
942 /* Primarily protects free_area */
943 spinlock_t lock;
944
945 /* Write-intensive fields used by compaction and vmstats. */
946 CACHELINE_PADDING(_pad2_);
947
948 /*
949 * When free pages are below this point, additional steps are taken
950 * when reading the number of free pages to avoid per-cpu counter
951 * drift allowing watermarks to be breached
952 */
953 unsigned long percpu_drift_mark;
954
955 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
956 /* pfn where compaction free scanner should start */
957 unsigned long compact_cached_free_pfn;
958 /* pfn where compaction migration scanner should start */
959 unsigned long compact_cached_migrate_pfn[ASYNC_AND_SYNC];
960 unsigned long compact_init_migrate_pfn;
961 unsigned long compact_init_free_pfn;
962 #endif
963
964 #ifdef CONFIG_COMPACTION
965 /*
966 * On compaction failure, 1<<compact_defer_shift compactions
967 * are skipped before trying again. The number attempted since
968 * last failure is tracked with compact_considered.
969 * compact_order_failed is the minimum compaction failed order.
970 */
971 unsigned int compact_considered;
972 unsigned int compact_defer_shift;
973 int compact_order_failed;
974 #endif
975
976 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
977 /* Set to true when the PG_migrate_skip bits should be cleared */
978 bool compact_blockskip_flush;
979 #endif
980
981 bool contiguous;
982
983 CACHELINE_PADDING(_pad3_);
984 /* Zone statistics */
985 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
986 atomic_long_t vm_numa_event[NR_VM_NUMA_EVENT_ITEMS];
987 } ____cacheline_internodealigned_in_smp;
988
989 enum pgdat_flags {
990 PGDAT_DIRTY, /* reclaim scanning has recently found
991 * many dirty file pages at the tail
992 * of the LRU.
993 */
994 PGDAT_WRITEBACK, /* reclaim scanning has recently found
995 * many pages under writeback
996 */
997 PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */
998 };
999
1000 enum zone_flags {
1001 ZONE_BOOSTED_WATERMARK, /* zone recently boosted watermarks.
1002 * Cleared when kswapd is woken.
1003 */
1004 ZONE_RECLAIM_ACTIVE, /* kswapd may be scanning the zone. */
1005 };
1006
zone_managed_pages(struct zone * zone)1007 static inline unsigned long zone_managed_pages(struct zone *zone)
1008 {
1009 return (unsigned long)atomic_long_read(&zone->managed_pages);
1010 }
1011
zone_cma_pages(struct zone * zone)1012 static inline unsigned long zone_cma_pages(struct zone *zone)
1013 {
1014 #ifdef CONFIG_CMA
1015 return zone->cma_pages;
1016 #else
1017 return 0;
1018 #endif
1019 }
1020
zone_end_pfn(const struct zone * zone)1021 static inline unsigned long zone_end_pfn(const struct zone *zone)
1022 {
1023 return zone->zone_start_pfn + zone->spanned_pages;
1024 }
1025
zone_spans_pfn(const struct zone * zone,unsigned long pfn)1026 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)
1027 {
1028 return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone);
1029 }
1030
zone_is_initialized(struct zone * zone)1031 static inline bool zone_is_initialized(struct zone *zone)
1032 {
1033 return zone->initialized;
1034 }
1035
zone_is_empty(struct zone * zone)1036 static inline bool zone_is_empty(struct zone *zone)
1037 {
1038 return zone->spanned_pages == 0;
1039 }
1040
1041 #ifndef BUILD_VDSO32_64
1042 /*
1043 * The zone field is never updated after free_area_init_core()
1044 * sets it, so none of the operations on it need to be atomic.
1045 */
1046
1047 /* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_CPUPID] | ... | FLAGS | */
1048 #define SECTIONS_PGOFF ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
1049 #define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH)
1050 #define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH)
1051 #define LAST_CPUPID_PGOFF (ZONES_PGOFF - LAST_CPUPID_WIDTH)
1052 #define KASAN_TAG_PGOFF (LAST_CPUPID_PGOFF - KASAN_TAG_WIDTH)
1053 #define LRU_GEN_PGOFF (KASAN_TAG_PGOFF - LRU_GEN_WIDTH)
1054 #define LRU_REFS_PGOFF (LRU_GEN_PGOFF - LRU_REFS_WIDTH)
1055
1056 /*
1057 * Define the bit shifts to access each section. For non-existent
1058 * sections we define the shift as 0; that plus a 0 mask ensures
1059 * the compiler will optimise away reference to them.
1060 */
1061 #define SECTIONS_PGSHIFT (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
1062 #define NODES_PGSHIFT (NODES_PGOFF * (NODES_WIDTH != 0))
1063 #define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_WIDTH != 0))
1064 #define LAST_CPUPID_PGSHIFT (LAST_CPUPID_PGOFF * (LAST_CPUPID_WIDTH != 0))
1065 #define KASAN_TAG_PGSHIFT (KASAN_TAG_PGOFF * (KASAN_TAG_WIDTH != 0))
1066
1067 /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */
1068 #ifdef NODE_NOT_IN_PAGE_FLAGS
1069 #define ZONEID_SHIFT (SECTIONS_SHIFT + ZONES_SHIFT)
1070 #define ZONEID_PGOFF ((SECTIONS_PGOFF < ZONES_PGOFF) ? \
1071 SECTIONS_PGOFF : ZONES_PGOFF)
1072 #else
1073 #define ZONEID_SHIFT (NODES_SHIFT + ZONES_SHIFT)
1074 #define ZONEID_PGOFF ((NODES_PGOFF < ZONES_PGOFF) ? \
1075 NODES_PGOFF : ZONES_PGOFF)
1076 #endif
1077
1078 #define ZONEID_PGSHIFT (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
1079
1080 #define ZONES_MASK ((1UL << ZONES_WIDTH) - 1)
1081 #define NODES_MASK ((1UL << NODES_WIDTH) - 1)
1082 #define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1)
1083 #define LAST_CPUPID_MASK ((1UL << LAST_CPUPID_SHIFT) - 1)
1084 #define KASAN_TAG_MASK ((1UL << KASAN_TAG_WIDTH) - 1)
1085 #define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1)
1086
page_zonenum(const struct page * page)1087 static inline enum zone_type page_zonenum(const struct page *page)
1088 {
1089 ASSERT_EXCLUSIVE_BITS(page->flags, ZONES_MASK << ZONES_PGSHIFT);
1090 return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
1091 }
1092
folio_zonenum(const struct folio * folio)1093 static inline enum zone_type folio_zonenum(const struct folio *folio)
1094 {
1095 return page_zonenum(&folio->page);
1096 }
1097
1098 #ifdef CONFIG_ZONE_DEVICE
is_zone_device_page(const struct page * page)1099 static inline bool is_zone_device_page(const struct page *page)
1100 {
1101 return page_zonenum(page) == ZONE_DEVICE;
1102 }
1103
1104 /*
1105 * Consecutive zone device pages should not be merged into the same sgl
1106 * or bvec segment with other types of pages or if they belong to different
1107 * pgmaps. Otherwise getting the pgmap of a given segment is not possible
1108 * without scanning the entire segment. This helper returns true either if
1109 * both pages are not zone device pages or both pages are zone device pages
1110 * with the same pgmap.
1111 */
zone_device_pages_have_same_pgmap(const struct page * a,const struct page * b)1112 static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
1113 const struct page *b)
1114 {
1115 if (is_zone_device_page(a) != is_zone_device_page(b))
1116 return false;
1117 if (!is_zone_device_page(a))
1118 return true;
1119 return a->pgmap == b->pgmap;
1120 }
1121
1122 extern void memmap_init_zone_device(struct zone *, unsigned long,
1123 unsigned long, struct dev_pagemap *);
1124 #else
is_zone_device_page(const struct page * page)1125 static inline bool is_zone_device_page(const struct page *page)
1126 {
1127 return false;
1128 }
zone_device_pages_have_same_pgmap(const struct page * a,const struct page * b)1129 static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
1130 const struct page *b)
1131 {
1132 return true;
1133 }
1134 #endif
1135
folio_is_zone_device(const struct folio * folio)1136 static inline bool folio_is_zone_device(const struct folio *folio)
1137 {
1138 return is_zone_device_page(&folio->page);
1139 }
1140
is_zone_movable_page(const struct page * page)1141 static inline bool is_zone_movable_page(const struct page *page)
1142 {
1143 return page_zonenum(page) == ZONE_MOVABLE;
1144 }
1145
folio_is_zone_movable(const struct folio * folio)1146 static inline bool folio_is_zone_movable(const struct folio *folio)
1147 {
1148 return folio_zonenum(folio) == ZONE_MOVABLE;
1149 }
1150 #endif
1151
1152 /*
1153 * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty
1154 * intersection with the given zone
1155 */
zone_intersects(struct zone * zone,unsigned long start_pfn,unsigned long nr_pages)1156 static inline bool zone_intersects(struct zone *zone,
1157 unsigned long start_pfn, unsigned long nr_pages)
1158 {
1159 if (zone_is_empty(zone))
1160 return false;
1161 if (start_pfn >= zone_end_pfn(zone) ||
1162 start_pfn + nr_pages <= zone->zone_start_pfn)
1163 return false;
1164
1165 return true;
1166 }
1167
1168 /*
1169 * The "priority" of VM scanning is how much of the queues we will scan in one
1170 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
1171 * queues ("queue_length >> 12") during an aging round.
1172 */
1173 #define DEF_PRIORITY 12
1174
1175 /* Maximum number of zones on a zonelist */
1176 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
1177
1178 enum {
1179 ZONELIST_FALLBACK, /* zonelist with fallback */
1180 #ifdef CONFIG_NUMA
1181 /*
1182 * The NUMA zonelists are doubled because we need zonelists that
1183 * restrict the allocations to a single node for __GFP_THISNODE.
1184 */
1185 ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */
1186 #endif
1187 MAX_ZONELISTS
1188 };
1189
1190 /*
1191 * This struct contains information about a zone in a zonelist. It is stored
1192 * here to avoid dereferences into large structures and lookups of tables
1193 */
1194 struct zoneref {
1195 struct zone *zone; /* Pointer to actual zone */
1196 int zone_idx; /* zone_idx(zoneref->zone) */
1197 };
1198
1199 /*
1200 * One allocation request operates on a zonelist. A zonelist
1201 * is a list of zones, the first one is the 'goal' of the
1202 * allocation, the other zones are fallback zones, in decreasing
1203 * priority.
1204 *
1205 * To speed the reading of the zonelist, the zonerefs contain the zone index
1206 * of the entry being read. Helper functions to access information given
1207 * a struct zoneref are
1208 *
1209 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
1210 * zonelist_zone_idx() - Return the index of the zone for an entry
1211 * zonelist_node_idx() - Return the index of the node for an entry
1212 */
1213 struct zonelist {
1214 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
1215 };
1216
1217 /*
1218 * The array of struct pages for flatmem.
1219 * It must be declared for SPARSEMEM as well because there are configurations
1220 * that rely on that.
1221 */
1222 extern struct page *mem_map;
1223
1224 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1225 struct deferred_split {
1226 spinlock_t split_queue_lock;
1227 struct list_head split_queue;
1228 unsigned long split_queue_len;
1229 };
1230 #endif
1231
1232 #ifdef CONFIG_MEMORY_FAILURE
1233 /*
1234 * Per NUMA node memory failure handling statistics.
1235 */
1236 struct memory_failure_stats {
1237 /*
1238 * Number of raw pages poisoned.
1239 * Cases not accounted: memory outside kernel control, offline page,
1240 * arch-specific memory_failure (SGX), hwpoison_filter() filtered
1241 * error events, and unpoison actions from hwpoison_unpoison.
1242 */
1243 unsigned long total;
1244 /*
1245 * Recovery results of poisoned raw pages handled by memory_failure,
1246 * in sync with mf_result.
1247 * total = ignored + failed + delayed + recovered.
1248 * total * PAGE_SIZE * #nodes = /proc/meminfo/HardwareCorrupted.
1249 */
1250 unsigned long ignored;
1251 unsigned long failed;
1252 unsigned long delayed;
1253 unsigned long recovered;
1254 };
1255 #endif
1256
1257 /*
1258 * On NUMA machines, each NUMA node would have a pg_data_t to describe
1259 * it's memory layout. On UMA machines there is a single pglist_data which
1260 * describes the whole memory.
1261 *
1262 * Memory statistics and page replacement data structures are maintained on a
1263 * per-zone basis.
1264 */
1265 typedef struct pglist_data {
1266 /*
1267 * node_zones contains just the zones for THIS node. Not all of the
1268 * zones may be populated, but it is the full list. It is referenced by
1269 * this node's node_zonelists as well as other node's node_zonelists.
1270 */
1271 struct zone node_zones[MAX_NR_ZONES];
1272
1273 /*
1274 * node_zonelists contains references to all zones in all nodes.
1275 * Generally the first zones will be references to this node's
1276 * node_zones.
1277 */
1278 struct zonelist node_zonelists[MAX_ZONELISTS];
1279
1280 int nr_zones; /* number of populated zones in this node */
1281 #ifdef CONFIG_FLATMEM /* means !SPARSEMEM */
1282 struct page *node_mem_map;
1283 #ifdef CONFIG_PAGE_EXTENSION
1284 struct page_ext *node_page_ext;
1285 #endif
1286 #endif
1287 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
1288 /*
1289 * Must be held any time you expect node_start_pfn,
1290 * node_present_pages, node_spanned_pages or nr_zones to stay constant.
1291 * Also synchronizes pgdat->first_deferred_pfn during deferred page
1292 * init.
1293 *
1294 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to
1295 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG
1296 * or CONFIG_DEFERRED_STRUCT_PAGE_INIT.
1297 *
1298 * Nests above zone->lock and zone->span_seqlock
1299 */
1300 spinlock_t node_size_lock;
1301 #endif
1302 unsigned long node_start_pfn;
1303 unsigned long node_present_pages; /* total number of physical pages */
1304 unsigned long node_spanned_pages; /* total size of physical page
1305 range, including holes */
1306 int node_id;
1307 wait_queue_head_t kswapd_wait;
1308 wait_queue_head_t pfmemalloc_wait;
1309
1310 /* workqueues for throttling reclaim for different reasons. */
1311 wait_queue_head_t reclaim_wait[NR_VMSCAN_THROTTLE];
1312
1313 atomic_t nr_writeback_throttled;/* nr of writeback-throttled tasks */
1314 unsigned long nr_reclaim_start; /* nr pages written while throttled
1315 * when throttling started. */
1316 #ifdef CONFIG_MEMORY_HOTPLUG
1317 struct mutex kswapd_lock;
1318 #endif
1319 struct task_struct *kswapd; /* Protected by kswapd_lock */
1320 int kswapd_order;
1321 enum zone_type kswapd_highest_zoneidx;
1322
1323 int kswapd_failures; /* Number of 'reclaimed == 0' runs */
1324
1325 #ifdef CONFIG_COMPACTION
1326 int kcompactd_max_order;
1327 enum zone_type kcompactd_highest_zoneidx;
1328 wait_queue_head_t kcompactd_wait;
1329 struct task_struct *kcompactd;
1330 bool proactive_compact_trigger;
1331 #endif
1332 /*
1333 * This is a per-node reserve of pages that are not available
1334 * to userspace allocations.
1335 */
1336 unsigned long totalreserve_pages;
1337
1338 #ifdef CONFIG_NUMA
1339 /*
1340 * node reclaim becomes active if more unmapped pages exist.
1341 */
1342 unsigned long min_unmapped_pages;
1343 unsigned long min_slab_pages;
1344 #endif /* CONFIG_NUMA */
1345
1346 /* Write-intensive fields used by page reclaim */
1347 CACHELINE_PADDING(_pad1_);
1348
1349 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1350 /*
1351 * If memory initialisation on large machines is deferred then this
1352 * is the first PFN that needs to be initialised.
1353 */
1354 unsigned long first_deferred_pfn;
1355 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1356
1357 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1358 struct deferred_split deferred_split_queue;
1359 #endif
1360
1361 #ifdef CONFIG_NUMA_BALANCING
1362 /* start time in ms of current promote rate limit period */
1363 unsigned int nbp_rl_start;
1364 /* number of promote candidate pages at start time of current rate limit period */
1365 unsigned long nbp_rl_nr_cand;
1366 /* promote threshold in ms */
1367 unsigned int nbp_threshold;
1368 /* start time in ms of current promote threshold adjustment period */
1369 unsigned int nbp_th_start;
1370 /*
1371 * number of promote candidate pages at start time of current promote
1372 * threshold adjustment period
1373 */
1374 unsigned long nbp_th_nr_cand;
1375 #endif
1376 /* Fields commonly accessed by the page reclaim scanner */
1377
1378 /*
1379 * NOTE: THIS IS UNUSED IF MEMCG IS ENABLED.
1380 *
1381 * Use mem_cgroup_lruvec() to look up lruvecs.
1382 */
1383 struct lruvec __lruvec;
1384
1385 unsigned long flags;
1386
1387 #ifdef CONFIG_LRU_GEN
1388 /* kswap mm walk data */
1389 struct lru_gen_mm_walk mm_walk;
1390 /* lru_gen_folio list */
1391 struct lru_gen_memcg memcg_lru;
1392 #endif
1393
1394 CACHELINE_PADDING(_pad2_);
1395
1396 /* Per-node vmstats */
1397 struct per_cpu_nodestat __percpu *per_cpu_nodestats;
1398 atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS];
1399 #ifdef CONFIG_NUMA
1400 struct memory_tier __rcu *memtier;
1401 #endif
1402 #ifdef CONFIG_MEMORY_FAILURE
1403 struct memory_failure_stats mf_stats;
1404 #endif
1405 } pg_data_t;
1406
1407 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
1408 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
1409
1410 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn)
1411 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))
1412
pgdat_end_pfn(pg_data_t * pgdat)1413 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat)
1414 {
1415 return pgdat->node_start_pfn + pgdat->node_spanned_pages;
1416 }
1417
1418 #include <linux/memory_hotplug.h>
1419
1420 void build_all_zonelists(pg_data_t *pgdat);
1421 void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order,
1422 enum zone_type highest_zoneidx);
1423 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
1424 int highest_zoneidx, unsigned int alloc_flags,
1425 long free_pages);
1426 bool zone_watermark_ok(struct zone *z, unsigned int order,
1427 unsigned long mark, int highest_zoneidx,
1428 unsigned int alloc_flags);
1429 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
1430 unsigned long mark, int highest_zoneidx);
1431 /*
1432 * Memory initialization context, use to differentiate memory added by
1433 * the platform statically or via memory hotplug interface.
1434 */
1435 enum meminit_context {
1436 MEMINIT_EARLY,
1437 MEMINIT_HOTPLUG,
1438 };
1439
1440 extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
1441 unsigned long size);
1442
1443 extern void lruvec_init(struct lruvec *lruvec);
1444
lruvec_pgdat(struct lruvec * lruvec)1445 static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec)
1446 {
1447 #ifdef CONFIG_MEMCG
1448 return lruvec->pgdat;
1449 #else
1450 return container_of(lruvec, struct pglist_data, __lruvec);
1451 #endif
1452 }
1453
1454 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
1455 int local_memory_node(int node_id);
1456 #else
local_memory_node(int node_id)1457 static inline int local_memory_node(int node_id) { return node_id; };
1458 #endif
1459
1460 /*
1461 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
1462 */
1463 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
1464
1465 #ifdef CONFIG_ZONE_DEVICE
zone_is_zone_device(struct zone * zone)1466 static inline bool zone_is_zone_device(struct zone *zone)
1467 {
1468 return zone_idx(zone) == ZONE_DEVICE;
1469 }
1470 #else
zone_is_zone_device(struct zone * zone)1471 static inline bool zone_is_zone_device(struct zone *zone)
1472 {
1473 return false;
1474 }
1475 #endif
1476
1477 /*
1478 * Returns true if a zone has pages managed by the buddy allocator.
1479 * All the reclaim decisions have to use this function rather than
1480 * populated_zone(). If the whole zone is reserved then we can easily
1481 * end up with populated_zone() && !managed_zone().
1482 */
managed_zone(struct zone * zone)1483 static inline bool managed_zone(struct zone *zone)
1484 {
1485 return zone_managed_pages(zone);
1486 }
1487
1488 /* Returns true if a zone has memory */
populated_zone(struct zone * zone)1489 static inline bool populated_zone(struct zone *zone)
1490 {
1491 return zone->present_pages;
1492 }
1493
1494 #ifdef CONFIG_NUMA
zone_to_nid(struct zone * zone)1495 static inline int zone_to_nid(struct zone *zone)
1496 {
1497 return zone->node;
1498 }
1499
zone_set_nid(struct zone * zone,int nid)1500 static inline void zone_set_nid(struct zone *zone, int nid)
1501 {
1502 zone->node = nid;
1503 }
1504 #else
zone_to_nid(struct zone * zone)1505 static inline int zone_to_nid(struct zone *zone)
1506 {
1507 return 0;
1508 }
1509
zone_set_nid(struct zone * zone,int nid)1510 static inline void zone_set_nid(struct zone *zone, int nid) {}
1511 #endif
1512
1513 extern int movable_zone;
1514
is_highmem_idx(enum zone_type idx)1515 static inline int is_highmem_idx(enum zone_type idx)
1516 {
1517 #ifdef CONFIG_HIGHMEM
1518 return (idx == ZONE_HIGHMEM ||
1519 (idx == ZONE_MOVABLE && movable_zone == ZONE_HIGHMEM));
1520 #else
1521 return 0;
1522 #endif
1523 }
1524
1525 /**
1526 * is_highmem - helper function to quickly check if a struct zone is a
1527 * highmem zone or not. This is an attempt to keep references
1528 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
1529 * @zone: pointer to struct zone variable
1530 * Return: 1 for a highmem zone, 0 otherwise
1531 */
is_highmem(struct zone * zone)1532 static inline int is_highmem(struct zone *zone)
1533 {
1534 return is_highmem_idx(zone_idx(zone));
1535 }
1536
1537 #ifdef CONFIG_ZONE_DMA
1538 bool has_managed_dma(void);
1539 #else
has_managed_dma(void)1540 static inline bool has_managed_dma(void)
1541 {
1542 return false;
1543 }
1544 #endif
1545
1546
1547 #ifndef CONFIG_NUMA
1548
1549 extern struct pglist_data contig_page_data;
NODE_DATA(int nid)1550 static inline struct pglist_data *NODE_DATA(int nid)
1551 {
1552 return &contig_page_data;
1553 }
1554
1555 #else /* CONFIG_NUMA */
1556
1557 #include <asm/mmzone.h>
1558
1559 #endif /* !CONFIG_NUMA */
1560
1561 extern struct pglist_data *first_online_pgdat(void);
1562 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
1563 extern struct zone *next_zone(struct zone *zone);
1564
1565 /**
1566 * for_each_online_pgdat - helper macro to iterate over all online nodes
1567 * @pgdat: pointer to a pg_data_t variable
1568 */
1569 #define for_each_online_pgdat(pgdat) \
1570 for (pgdat = first_online_pgdat(); \
1571 pgdat; \
1572 pgdat = next_online_pgdat(pgdat))
1573 /**
1574 * for_each_zone - helper macro to iterate over all memory zones
1575 * @zone: pointer to struct zone variable
1576 *
1577 * The user only needs to declare the zone variable, for_each_zone
1578 * fills it in.
1579 */
1580 #define for_each_zone(zone) \
1581 for (zone = (first_online_pgdat())->node_zones; \
1582 zone; \
1583 zone = next_zone(zone))
1584
1585 #define for_each_populated_zone(zone) \
1586 for (zone = (first_online_pgdat())->node_zones; \
1587 zone; \
1588 zone = next_zone(zone)) \
1589 if (!populated_zone(zone)) \
1590 ; /* do nothing */ \
1591 else
1592
zonelist_zone(struct zoneref * zoneref)1593 static inline struct zone *zonelist_zone(struct zoneref *zoneref)
1594 {
1595 return zoneref->zone;
1596 }
1597
zonelist_zone_idx(struct zoneref * zoneref)1598 static inline int zonelist_zone_idx(struct zoneref *zoneref)
1599 {
1600 return zoneref->zone_idx;
1601 }
1602
zonelist_node_idx(struct zoneref * zoneref)1603 static inline int zonelist_node_idx(struct zoneref *zoneref)
1604 {
1605 return zone_to_nid(zoneref->zone);
1606 }
1607
1608 struct zoneref *__next_zones_zonelist(struct zoneref *z,
1609 enum zone_type highest_zoneidx,
1610 nodemask_t *nodes);
1611
1612 /**
1613 * 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
1614 * @z: The cursor used as a starting point for the search
1615 * @highest_zoneidx: The zone index of the highest zone to return
1616 * @nodes: An optional nodemask to filter the zonelist with
1617 *
1618 * This function returns the next zone at or below a given zone index that is
1619 * within the allowed nodemask using a cursor as the starting point for the
1620 * search. The zoneref returned is a cursor that represents the current zone
1621 * being examined. It should be advanced by one before calling
1622 * next_zones_zonelist again.
1623 *
1624 * Return: the next zone at or below highest_zoneidx within the allowed
1625 * nodemask using a cursor within a zonelist as a starting point
1626 */
next_zones_zonelist(struct zoneref * z,enum zone_type highest_zoneidx,nodemask_t * nodes)1627 static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z,
1628 enum zone_type highest_zoneidx,
1629 nodemask_t *nodes)
1630 {
1631 if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx))
1632 return z;
1633 return __next_zones_zonelist(z, highest_zoneidx, nodes);
1634 }
1635
1636 /**
1637 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
1638 * @zonelist: The zonelist to search for a suitable zone
1639 * @highest_zoneidx: The zone index of the highest zone to return
1640 * @nodes: An optional nodemask to filter the zonelist with
1641 *
1642 * This function returns the first zone at or below a given zone index that is
1643 * within the allowed nodemask. The zoneref returned is a cursor that can be
1644 * used to iterate the zonelist with next_zones_zonelist by advancing it by
1645 * one before calling.
1646 *
1647 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is
1648 * never NULL). This may happen either genuinely, or due to concurrent nodemask
1649 * update due to cpuset modification.
1650 *
1651 * Return: Zoneref pointer for the first suitable zone found
1652 */
first_zones_zonelist(struct zonelist * zonelist,enum zone_type highest_zoneidx,nodemask_t * nodes)1653 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
1654 enum zone_type highest_zoneidx,
1655 nodemask_t *nodes)
1656 {
1657 return next_zones_zonelist(zonelist->_zonerefs,
1658 highest_zoneidx, nodes);
1659 }
1660
1661 /**
1662 * 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
1663 * @zone: The current zone in the iterator
1664 * @z: The current pointer within zonelist->_zonerefs being iterated
1665 * @zlist: The zonelist being iterated
1666 * @highidx: The zone index of the highest zone to return
1667 * @nodemask: Nodemask allowed by the allocator
1668 *
1669 * This iterator iterates though all zones at or below a given zone index and
1670 * within a given nodemask
1671 */
1672 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
1673 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \
1674 zone; \
1675 z = next_zones_zonelist(++z, highidx, nodemask), \
1676 zone = zonelist_zone(z))
1677
1678 #define for_next_zone_zonelist_nodemask(zone, z, highidx, nodemask) \
1679 for (zone = z->zone; \
1680 zone; \
1681 z = next_zones_zonelist(++z, highidx, nodemask), \
1682 zone = zonelist_zone(z))
1683
1684
1685 /**
1686 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
1687 * @zone: The current zone in the iterator
1688 * @z: The current pointer within zonelist->zones being iterated
1689 * @zlist: The zonelist being iterated
1690 * @highidx: The zone index of the highest zone to return
1691 *
1692 * This iterator iterates though all zones at or below a given zone index.
1693 */
1694 #define for_each_zone_zonelist(zone, z, zlist, highidx) \
1695 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
1696
1697 /* Whether the 'nodes' are all movable nodes */
movable_only_nodes(nodemask_t * nodes)1698 static inline bool movable_only_nodes(nodemask_t *nodes)
1699 {
1700 struct zonelist *zonelist;
1701 struct zoneref *z;
1702 int nid;
1703
1704 if (nodes_empty(*nodes))
1705 return false;
1706
1707 /*
1708 * We can chose arbitrary node from the nodemask to get a
1709 * zonelist as they are interlinked. We just need to find
1710 * at least one zone that can satisfy kernel allocations.
1711 */
1712 nid = first_node(*nodes);
1713 zonelist = &NODE_DATA(nid)->node_zonelists[ZONELIST_FALLBACK];
1714 z = first_zones_zonelist(zonelist, ZONE_NORMAL, nodes);
1715 return (!z->zone) ? true : false;
1716 }
1717
1718
1719 #ifdef CONFIG_SPARSEMEM
1720 #include <asm/sparsemem.h>
1721 #endif
1722
1723 #ifdef CONFIG_FLATMEM
1724 #define pfn_to_nid(pfn) (0)
1725 #endif
1726
1727 #ifdef CONFIG_SPARSEMEM
1728
1729 /*
1730 * PA_SECTION_SHIFT physical address to/from section number
1731 * PFN_SECTION_SHIFT pfn to/from section number
1732 */
1733 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
1734 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
1735
1736 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
1737
1738 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
1739 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
1740
1741 #define SECTION_BLOCKFLAGS_BITS \
1742 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
1743
1744 #if (MAX_ORDER + PAGE_SHIFT) > SECTION_SIZE_BITS
1745 #error Allocator MAX_ORDER exceeds SECTION_SIZE
1746 #endif
1747
pfn_to_section_nr(unsigned long pfn)1748 static inline unsigned long pfn_to_section_nr(unsigned long pfn)
1749 {
1750 return pfn >> PFN_SECTION_SHIFT;
1751 }
section_nr_to_pfn(unsigned long sec)1752 static inline unsigned long section_nr_to_pfn(unsigned long sec)
1753 {
1754 return sec << PFN_SECTION_SHIFT;
1755 }
1756
1757 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)
1758 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK)
1759
1760 #define SUBSECTION_SHIFT 21
1761 #define SUBSECTION_SIZE (1UL << SUBSECTION_SHIFT)
1762
1763 #define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT)
1764 #define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT)
1765 #define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1))
1766
1767 #if SUBSECTION_SHIFT > SECTION_SIZE_BITS
1768 #error Subsection size exceeds section size
1769 #else
1770 #define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT))
1771 #endif
1772
1773 #define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION)
1774 #define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK)
1775
1776 struct mem_section_usage {
1777 struct rcu_head rcu;
1778 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1779 DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION);
1780 #endif
1781 /* See declaration of similar field in struct zone */
1782 unsigned long pageblock_flags[0];
1783 };
1784
1785 void subsection_map_init(unsigned long pfn, unsigned long nr_pages);
1786
1787 struct page;
1788 struct page_ext;
1789 struct mem_section {
1790 /*
1791 * This is, logically, a pointer to an array of struct
1792 * pages. However, it is stored with some other magic.
1793 * (see sparse.c::sparse_init_one_section())
1794 *
1795 * Additionally during early boot we encode node id of
1796 * the location of the section here to guide allocation.
1797 * (see sparse.c::memory_present())
1798 *
1799 * Making it a UL at least makes someone do a cast
1800 * before using it wrong.
1801 */
1802 unsigned long section_mem_map;
1803
1804 struct mem_section_usage *usage;
1805 #ifdef CONFIG_PAGE_EXTENSION
1806 /*
1807 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use
1808 * section. (see page_ext.h about this.)
1809 */
1810 struct page_ext *page_ext;
1811 unsigned long pad;
1812 #endif
1813 /*
1814 * WARNING: mem_section must be a power-of-2 in size for the
1815 * calculation and use of SECTION_ROOT_MASK to make sense.
1816 */
1817 };
1818
1819 #ifdef CONFIG_SPARSEMEM_EXTREME
1820 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
1821 #else
1822 #define SECTIONS_PER_ROOT 1
1823 #endif
1824
1825 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
1826 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT)
1827 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
1828
1829 #ifdef CONFIG_SPARSEMEM_EXTREME
1830 extern struct mem_section **mem_section;
1831 #else
1832 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
1833 #endif
1834
section_to_usemap(struct mem_section * ms)1835 static inline unsigned long *section_to_usemap(struct mem_section *ms)
1836 {
1837 return ms->usage->pageblock_flags;
1838 }
1839
__nr_to_section(unsigned long nr)1840 static inline struct mem_section *__nr_to_section(unsigned long nr)
1841 {
1842 unsigned long root = SECTION_NR_TO_ROOT(nr);
1843
1844 if (unlikely(root >= NR_SECTION_ROOTS))
1845 return NULL;
1846
1847 #ifdef CONFIG_SPARSEMEM_EXTREME
1848 if (!mem_section || !mem_section[root])
1849 return NULL;
1850 #endif
1851 return &mem_section[root][nr & SECTION_ROOT_MASK];
1852 }
1853 extern size_t mem_section_usage_size(void);
1854
1855 /*
1856 * We use the lower bits of the mem_map pointer to store
1857 * a little bit of information. The pointer is calculated
1858 * as mem_map - section_nr_to_pfn(pnum). The result is
1859 * aligned to the minimum alignment of the two values:
1860 * 1. All mem_map arrays are page-aligned.
1861 * 2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT
1862 * lowest bits. PFN_SECTION_SHIFT is arch-specific
1863 * (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the
1864 * worst combination is powerpc with 256k pages,
1865 * which results in PFN_SECTION_SHIFT equal 6.
1866 * To sum it up, at least 6 bits are available on all architectures.
1867 * However, we can exceed 6 bits on some other architectures except
1868 * powerpc (e.g. 15 bits are available on x86_64, 13 bits are available
1869 * with the worst case of 64K pages on arm64) if we make sure the
1870 * exceeded bit is not applicable to powerpc.
1871 */
1872 enum {
1873 SECTION_MARKED_PRESENT_BIT,
1874 SECTION_HAS_MEM_MAP_BIT,
1875 SECTION_IS_ONLINE_BIT,
1876 SECTION_IS_EARLY_BIT,
1877 #ifdef CONFIG_ZONE_DEVICE
1878 SECTION_TAINT_ZONE_DEVICE_BIT,
1879 #endif
1880 SECTION_MAP_LAST_BIT,
1881 };
1882
1883 #define SECTION_MARKED_PRESENT BIT(SECTION_MARKED_PRESENT_BIT)
1884 #define SECTION_HAS_MEM_MAP BIT(SECTION_HAS_MEM_MAP_BIT)
1885 #define SECTION_IS_ONLINE BIT(SECTION_IS_ONLINE_BIT)
1886 #define SECTION_IS_EARLY BIT(SECTION_IS_EARLY_BIT)
1887 #ifdef CONFIG_ZONE_DEVICE
1888 #define SECTION_TAINT_ZONE_DEVICE BIT(SECTION_TAINT_ZONE_DEVICE_BIT)
1889 #endif
1890 #define SECTION_MAP_MASK (~(BIT(SECTION_MAP_LAST_BIT) - 1))
1891 #define SECTION_NID_SHIFT SECTION_MAP_LAST_BIT
1892
__section_mem_map_addr(struct mem_section * section)1893 static inline struct page *__section_mem_map_addr(struct mem_section *section)
1894 {
1895 unsigned long map = section->section_mem_map;
1896 map &= SECTION_MAP_MASK;
1897 return (struct page *)map;
1898 }
1899
present_section(struct mem_section * section)1900 static inline int present_section(struct mem_section *section)
1901 {
1902 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
1903 }
1904
present_section_nr(unsigned long nr)1905 static inline int present_section_nr(unsigned long nr)
1906 {
1907 return present_section(__nr_to_section(nr));
1908 }
1909
valid_section(struct mem_section * section)1910 static inline int valid_section(struct mem_section *section)
1911 {
1912 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
1913 }
1914
early_section(struct mem_section * section)1915 static inline int early_section(struct mem_section *section)
1916 {
1917 return (section && (section->section_mem_map & SECTION_IS_EARLY));
1918 }
1919
valid_section_nr(unsigned long nr)1920 static inline int valid_section_nr(unsigned long nr)
1921 {
1922 return valid_section(__nr_to_section(nr));
1923 }
1924
online_section(struct mem_section * section)1925 static inline int online_section(struct mem_section *section)
1926 {
1927 return (section && (section->section_mem_map & SECTION_IS_ONLINE));
1928 }
1929
1930 #ifdef CONFIG_ZONE_DEVICE
online_device_section(struct mem_section * section)1931 static inline int online_device_section(struct mem_section *section)
1932 {
1933 unsigned long flags = SECTION_IS_ONLINE | SECTION_TAINT_ZONE_DEVICE;
1934
1935 return section && ((section->section_mem_map & flags) == flags);
1936 }
1937 #else
online_device_section(struct mem_section * section)1938 static inline int online_device_section(struct mem_section *section)
1939 {
1940 return 0;
1941 }
1942 #endif
1943
online_section_nr(unsigned long nr)1944 static inline int online_section_nr(unsigned long nr)
1945 {
1946 return online_section(__nr_to_section(nr));
1947 }
1948
1949 #ifdef CONFIG_MEMORY_HOTPLUG
1950 void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
1951 void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
1952 #endif
1953
__pfn_to_section(unsigned long pfn)1954 static inline struct mem_section *__pfn_to_section(unsigned long pfn)
1955 {
1956 return __nr_to_section(pfn_to_section_nr(pfn));
1957 }
1958
1959 extern unsigned long __highest_present_section_nr;
1960
subsection_map_index(unsigned long pfn)1961 static inline int subsection_map_index(unsigned long pfn)
1962 {
1963 return (pfn & ~(PAGE_SECTION_MASK)) / PAGES_PER_SUBSECTION;
1964 }
1965
1966 #ifdef CONFIG_SPARSEMEM_VMEMMAP
pfn_section_valid(struct mem_section * ms,unsigned long pfn)1967 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
1968 {
1969 int idx = subsection_map_index(pfn);
1970
1971 return test_bit(idx, READ_ONCE(ms->usage)->subsection_map);
1972 }
1973 #else
pfn_section_valid(struct mem_section * ms,unsigned long pfn)1974 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
1975 {
1976 return 1;
1977 }
1978 #endif
1979
1980 #ifndef CONFIG_HAVE_ARCH_PFN_VALID
1981 /**
1982 * pfn_valid - check if there is a valid memory map entry for a PFN
1983 * @pfn: the page frame number to check
1984 *
1985 * Check if there is a valid memory map entry aka struct page for the @pfn.
1986 * Note, that availability of the memory map entry does not imply that
1987 * there is actual usable memory at that @pfn. The struct page may
1988 * represent a hole or an unusable page frame.
1989 *
1990 * Return: 1 for PFNs that have memory map entries and 0 otherwise
1991 */
pfn_valid(unsigned long pfn)1992 static inline int pfn_valid(unsigned long pfn)
1993 {
1994 struct mem_section *ms;
1995 int ret;
1996
1997 /*
1998 * Ensure the upper PAGE_SHIFT bits are clear in the
1999 * pfn. Else it might lead to false positives when
2000 * some of the upper bits are set, but the lower bits
2001 * match a valid pfn.
2002 */
2003 if (PHYS_PFN(PFN_PHYS(pfn)) != pfn)
2004 return 0;
2005
2006 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
2007 return 0;
2008 ms = __pfn_to_section(pfn);
2009 rcu_read_lock_sched();
2010 if (!valid_section(ms)) {
2011 rcu_read_unlock_sched();
2012 return 0;
2013 }
2014 /*
2015 * Traditionally early sections always returned pfn_valid() for
2016 * the entire section-sized span.
2017 */
2018 ret = early_section(ms) || pfn_section_valid(ms, pfn);
2019 rcu_read_unlock_sched();
2020
2021 return ret;
2022 }
2023 #endif
2024
pfn_in_present_section(unsigned long pfn)2025 static inline int pfn_in_present_section(unsigned long pfn)
2026 {
2027 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
2028 return 0;
2029 return present_section(__pfn_to_section(pfn));
2030 }
2031
next_present_section_nr(unsigned long section_nr)2032 static inline unsigned long next_present_section_nr(unsigned long section_nr)
2033 {
2034 while (++section_nr <= __highest_present_section_nr) {
2035 if (present_section_nr(section_nr))
2036 return section_nr;
2037 }
2038
2039 return -1;
2040 }
2041
2042 /*
2043 * These are _only_ used during initialisation, therefore they
2044 * can use __initdata ... They could have names to indicate
2045 * this restriction.
2046 */
2047 #ifdef CONFIG_NUMA
2048 #define pfn_to_nid(pfn) \
2049 ({ \
2050 unsigned long __pfn_to_nid_pfn = (pfn); \
2051 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
2052 })
2053 #else
2054 #define pfn_to_nid(pfn) (0)
2055 #endif
2056
2057 void sparse_init(void);
2058 #else
2059 #define sparse_init() do {} while (0)
2060 #define sparse_index_init(_sec, _nid) do {} while (0)
2061 #define pfn_in_present_section pfn_valid
2062 #define subsection_map_init(_pfn, _nr_pages) do {} while (0)
2063 #endif /* CONFIG_SPARSEMEM */
2064
2065 #endif /* !__GENERATING_BOUNDS.H */
2066 #endif /* !__ASSEMBLY__ */
2067 #endif /* _LINUX_MMZONE_H */
2068