Line data Source code
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 :
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 : */
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 : */
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 : */
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 65920668 : 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 :
284 : static inline bool is_file_lru(enum lru_list lru)
285 : {
286 : return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE);
287 : }
288 :
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 an 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 an 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 an 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 an 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 an memcg below low, which triggers
521 : * MEMCG_LRU_TAIL;
522 : * 3. The first attempt to reclaim an memcg below reclaimable size threshold,
523 : * which triggers MEMCG_LRU_TAIL;
524 : * 4. The second attempt to reclaim an memcg below reclaimable size threshold,
525 : * which triggers MEMCG_LRU_YOUNG;
526 : * 5. Attempting to reclaim an 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 an memcg, which triggers MEMCG_LRU_OLD.
529 : *
530 : * Note that memcg LRU only applies to global reclaim, and the round-robin
531 : * incrementing of their max_seq counters ensures the eventual fairness to all
532 : * eligible memcgs. For memcg reclaim, it still relies on mem_cgroup_iter().
533 : */
534 : #define MEMCG_NR_GENS 2
535 : #define MEMCG_NR_BINS 8
536 :
537 : struct lru_gen_memcg {
538 : /* the per-node memcg generation counter */
539 : unsigned long seq;
540 : /* each memcg has one lru_gen_folio per node */
541 : unsigned long nr_memcgs[MEMCG_NR_GENS];
542 : /* per-node lru_gen_folio list for global reclaim */
543 : struct hlist_nulls_head fifo[MEMCG_NR_GENS][MEMCG_NR_BINS];
544 : /* protects the above */
545 : spinlock_t lock;
546 : };
547 :
548 : void lru_gen_init_pgdat(struct pglist_data *pgdat);
549 :
550 : void lru_gen_init_memcg(struct mem_cgroup *memcg);
551 : void lru_gen_exit_memcg(struct mem_cgroup *memcg);
552 : void lru_gen_online_memcg(struct mem_cgroup *memcg);
553 : void lru_gen_offline_memcg(struct mem_cgroup *memcg);
554 : void lru_gen_release_memcg(struct mem_cgroup *memcg);
555 : void lru_gen_soft_reclaim(struct mem_cgroup *memcg, int nid);
556 :
557 : #else /* !CONFIG_MEMCG */
558 :
559 : #define MEMCG_NR_GENS 1
560 :
561 : struct lru_gen_memcg {
562 : };
563 :
564 : static inline void lru_gen_init_pgdat(struct pglist_data *pgdat)
565 : {
566 : }
567 :
568 : #endif /* CONFIG_MEMCG */
569 :
570 : #else /* !CONFIG_LRU_GEN */
571 :
572 : static inline void lru_gen_init_pgdat(struct pglist_data *pgdat)
573 : {
574 : }
575 :
576 : static inline void lru_gen_init_lruvec(struct lruvec *lruvec)
577 : {
578 : }
579 :
580 : static inline void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
581 : {
582 : }
583 :
584 : #ifdef CONFIG_MEMCG
585 :
586 : static inline void lru_gen_init_memcg(struct mem_cgroup *memcg)
587 : {
588 : }
589 :
590 : static inline void lru_gen_exit_memcg(struct mem_cgroup *memcg)
591 : {
592 : }
593 :
594 : static inline void lru_gen_online_memcg(struct mem_cgroup *memcg)
595 : {
596 : }
597 :
598 : static inline void lru_gen_offline_memcg(struct mem_cgroup *memcg)
599 : {
600 : }
601 :
602 : static inline void lru_gen_release_memcg(struct mem_cgroup *memcg)
603 : {
604 : }
605 :
606 : static inline void lru_gen_soft_reclaim(struct mem_cgroup *memcg, int nid)
607 : {
608 : }
609 :
610 : #endif /* CONFIG_MEMCG */
611 :
612 : #endif /* CONFIG_LRU_GEN */
613 :
614 : struct lruvec {
615 : struct list_head lists[NR_LRU_LISTS];
616 : /* per lruvec lru_lock for memcg */
617 : spinlock_t lru_lock;
618 : /*
619 : * These track the cost of reclaiming one LRU - file or anon -
620 : * over the other. As the observed cost of reclaiming one LRU
621 : * increases, the reclaim scan balance tips toward the other.
622 : */
623 : unsigned long anon_cost;
624 : unsigned long file_cost;
625 : /* Non-resident age, driven by LRU movement */
626 : atomic_long_t nonresident_age;
627 : /* Refaults at the time of last reclaim cycle */
628 : unsigned long refaults[ANON_AND_FILE];
629 : /* Various lruvec state flags (enum lruvec_flags) */
630 : unsigned long flags;
631 : #ifdef CONFIG_LRU_GEN
632 : /* evictable pages divided into generations */
633 : struct lru_gen_folio lrugen;
634 : /* to concurrently iterate lru_gen_mm_list */
635 : struct lru_gen_mm_state mm_state;
636 : #endif
637 : #ifdef CONFIG_MEMCG
638 : struct pglist_data *pgdat;
639 : #endif
640 : };
641 :
642 : /* Isolate unmapped pages */
643 : #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2)
644 : /* Isolate for asynchronous migration */
645 : #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4)
646 : /* Isolate unevictable pages */
647 : #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8)
648 :
649 : /* LRU Isolation modes. */
650 : typedef unsigned __bitwise isolate_mode_t;
651 :
652 : enum zone_watermarks {
653 : WMARK_MIN,
654 : WMARK_LOW,
655 : WMARK_HIGH,
656 : WMARK_PROMO,
657 : NR_WMARK
658 : };
659 :
660 : /*
661 : * One per migratetype for each PAGE_ALLOC_COSTLY_ORDER. One additional list
662 : * for THP which will usually be GFP_MOVABLE. Even if it is another type,
663 : * it should not contribute to serious fragmentation causing THP allocation
664 : * failures.
665 : */
666 : #ifdef CONFIG_TRANSPARENT_HUGEPAGE
667 : #define NR_PCP_THP 1
668 : #else
669 : #define NR_PCP_THP 0
670 : #endif
671 : #define NR_LOWORDER_PCP_LISTS (MIGRATE_PCPTYPES * (PAGE_ALLOC_COSTLY_ORDER + 1))
672 : #define NR_PCP_LISTS (NR_LOWORDER_PCP_LISTS + NR_PCP_THP)
673 :
674 : #define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost)
675 : #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost)
676 : #define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost)
677 : #define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost)
678 :
679 : /* Fields and list protected by pagesets local_lock in page_alloc.c */
680 : struct per_cpu_pages {
681 : spinlock_t lock; /* Protects lists field */
682 : int count; /* number of pages in the list */
683 : int high; /* high watermark, emptying needed */
684 : int batch; /* chunk size for buddy add/remove */
685 : short free_factor; /* batch scaling factor during free */
686 : #ifdef CONFIG_NUMA
687 : short expire; /* When 0, remote pagesets are drained */
688 : #endif
689 :
690 : /* Lists of pages, one per migrate type stored on the pcp-lists */
691 : struct list_head lists[NR_PCP_LISTS];
692 : } ____cacheline_aligned_in_smp;
693 :
694 : struct per_cpu_zonestat {
695 : #ifdef CONFIG_SMP
696 : s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
697 : s8 stat_threshold;
698 : #endif
699 : #ifdef CONFIG_NUMA
700 : /*
701 : * Low priority inaccurate counters that are only folded
702 : * on demand. Use a large type to avoid the overhead of
703 : * folding during refresh_cpu_vm_stats.
704 : */
705 : unsigned long vm_numa_event[NR_VM_NUMA_EVENT_ITEMS];
706 : #endif
707 : };
708 :
709 : struct per_cpu_nodestat {
710 : s8 stat_threshold;
711 : s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS];
712 : };
713 :
714 : #endif /* !__GENERATING_BOUNDS.H */
715 :
716 : enum zone_type {
717 : /*
718 : * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able
719 : * to DMA to all of the addressable memory (ZONE_NORMAL).
720 : * On architectures where this area covers the whole 32 bit address
721 : * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller
722 : * DMA addressing constraints. This distinction is important as a 32bit
723 : * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit
724 : * platforms may need both zones as they support peripherals with
725 : * different DMA addressing limitations.
726 : */
727 : #ifdef CONFIG_ZONE_DMA
728 : ZONE_DMA,
729 : #endif
730 : #ifdef CONFIG_ZONE_DMA32
731 : ZONE_DMA32,
732 : #endif
733 : /*
734 : * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
735 : * performed on pages in ZONE_NORMAL if the DMA devices support
736 : * transfers to all addressable memory.
737 : */
738 : ZONE_NORMAL,
739 : #ifdef CONFIG_HIGHMEM
740 : /*
741 : * A memory area that is only addressable by the kernel through
742 : * mapping portions into its own address space. This is for example
743 : * used by i386 to allow the kernel to address the memory beyond
744 : * 900MB. The kernel will set up special mappings (page
745 : * table entries on i386) for each page that the kernel needs to
746 : * access.
747 : */
748 : ZONE_HIGHMEM,
749 : #endif
750 : /*
751 : * ZONE_MOVABLE is similar to ZONE_NORMAL, except that it contains
752 : * movable pages with few exceptional cases described below. Main use
753 : * cases for ZONE_MOVABLE are to make memory offlining/unplug more
754 : * likely to succeed, and to locally limit unmovable allocations - e.g.,
755 : * to increase the number of THP/huge pages. Notable special cases are:
756 : *
757 : * 1. Pinned pages: (long-term) pinning of movable pages might
758 : * essentially turn such pages unmovable. Therefore, we do not allow
759 : * pinning long-term pages in ZONE_MOVABLE. When pages are pinned and
760 : * faulted, they come from the right zone right away. However, it is
761 : * still possible that address space already has pages in
762 : * ZONE_MOVABLE at the time when pages are pinned (i.e. user has
763 : * touches that memory before pinning). In such case we migrate them
764 : * to a different zone. When migration fails - pinning fails.
765 : * 2. memblock allocations: kernelcore/movablecore setups might create
766 : * situations where ZONE_MOVABLE contains unmovable allocations
767 : * after boot. Memory offlining and allocations fail early.
768 : * 3. Memory holes: kernelcore/movablecore setups might create very rare
769 : * situations where ZONE_MOVABLE contains memory holes after boot,
770 : * for example, if we have sections that are only partially
771 : * populated. Memory offlining and allocations fail early.
772 : * 4. PG_hwpoison pages: while poisoned pages can be skipped during
773 : * memory offlining, such pages cannot be allocated.
774 : * 5. Unmovable PG_offline pages: in paravirtualized environments,
775 : * hotplugged memory blocks might only partially be managed by the
776 : * buddy (e.g., via XEN-balloon, Hyper-V balloon, virtio-mem). The
777 : * parts not manged by the buddy are unmovable PG_offline pages. In
778 : * some cases (virtio-mem), such pages can be skipped during
779 : * memory offlining, however, cannot be moved/allocated. These
780 : * techniques might use alloc_contig_range() to hide previously
781 : * exposed pages from the buddy again (e.g., to implement some sort
782 : * of memory unplug in virtio-mem).
783 : * 6. ZERO_PAGE(0), kernelcore/movablecore setups might create
784 : * situations where ZERO_PAGE(0) which is allocated differently
785 : * on different platforms may end up in a movable zone. ZERO_PAGE(0)
786 : * cannot be migrated.
787 : * 7. Memory-hotplug: when using memmap_on_memory and onlining the
788 : * memory to the MOVABLE zone, the vmemmap pages are also placed in
789 : * such zone. Such pages cannot be really moved around as they are
790 : * self-stored in the range, but they are treated as movable when
791 : * the range they describe is about to be offlined.
792 : *
793 : * In general, no unmovable allocations that degrade memory offlining
794 : * should end up in ZONE_MOVABLE. Allocators (like alloc_contig_range())
795 : * have to expect that migrating pages in ZONE_MOVABLE can fail (even
796 : * if has_unmovable_pages() states that there are no unmovable pages,
797 : * there can be false negatives).
798 : */
799 : ZONE_MOVABLE,
800 : #ifdef CONFIG_ZONE_DEVICE
801 : ZONE_DEVICE,
802 : #endif
803 : __MAX_NR_ZONES
804 :
805 : };
806 :
807 : #ifndef __GENERATING_BOUNDS_H
808 :
809 : #define ASYNC_AND_SYNC 2
810 :
811 : struct zone {
812 : /* Read-mostly fields */
813 :
814 : /* zone watermarks, access with *_wmark_pages(zone) macros */
815 : unsigned long _watermark[NR_WMARK];
816 : unsigned long watermark_boost;
817 :
818 : unsigned long nr_reserved_highatomic;
819 :
820 : /*
821 : * We don't know if the memory that we're going to allocate will be
822 : * freeable or/and it will be released eventually, so to avoid totally
823 : * wasting several GB of ram we must reserve some of the lower zone
824 : * memory (otherwise we risk to run OOM on the lower zones despite
825 : * there being tons of freeable ram on the higher zones). This array is
826 : * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl
827 : * changes.
828 : */
829 : long lowmem_reserve[MAX_NR_ZONES];
830 :
831 : #ifdef CONFIG_NUMA
832 : int node;
833 : #endif
834 : struct pglist_data *zone_pgdat;
835 : struct per_cpu_pages __percpu *per_cpu_pageset;
836 : struct per_cpu_zonestat __percpu *per_cpu_zonestats;
837 : /*
838 : * the high and batch values are copied to individual pagesets for
839 : * faster access
840 : */
841 : int pageset_high;
842 : int pageset_batch;
843 :
844 : #ifndef CONFIG_SPARSEMEM
845 : /*
846 : * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
847 : * In SPARSEMEM, this map is stored in struct mem_section
848 : */
849 : unsigned long *pageblock_flags;
850 : #endif /* CONFIG_SPARSEMEM */
851 :
852 : /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
853 : unsigned long zone_start_pfn;
854 :
855 : /*
856 : * spanned_pages is the total pages spanned by the zone, including
857 : * holes, which is calculated as:
858 : * spanned_pages = zone_end_pfn - zone_start_pfn;
859 : *
860 : * present_pages is physical pages existing within the zone, which
861 : * is calculated as:
862 : * present_pages = spanned_pages - absent_pages(pages in holes);
863 : *
864 : * present_early_pages is present pages existing within the zone
865 : * located on memory available since early boot, excluding hotplugged
866 : * memory.
867 : *
868 : * managed_pages is present pages managed by the buddy system, which
869 : * is calculated as (reserved_pages includes pages allocated by the
870 : * bootmem allocator):
871 : * managed_pages = present_pages - reserved_pages;
872 : *
873 : * cma pages is present pages that are assigned for CMA use
874 : * (MIGRATE_CMA).
875 : *
876 : * So present_pages may be used by memory hotplug or memory power
877 : * management logic to figure out unmanaged pages by checking
878 : * (present_pages - managed_pages). And managed_pages should be used
879 : * by page allocator and vm scanner to calculate all kinds of watermarks
880 : * and thresholds.
881 : *
882 : * Locking rules:
883 : *
884 : * zone_start_pfn and spanned_pages are protected by span_seqlock.
885 : * It is a seqlock because it has to be read outside of zone->lock,
886 : * and it is done in the main allocator path. But, it is written
887 : * quite infrequently.
888 : *
889 : * The span_seq lock is declared along with zone->lock because it is
890 : * frequently read in proximity to zone->lock. It's good to
891 : * give them a chance of being in the same cacheline.
892 : *
893 : * Write access to present_pages at runtime should be protected by
894 : * mem_hotplug_begin/done(). Any reader who can't tolerant drift of
895 : * present_pages should use get_online_mems() to get a stable value.
896 : */
897 : atomic_long_t managed_pages;
898 : unsigned long spanned_pages;
899 : unsigned long present_pages;
900 : #if defined(CONFIG_MEMORY_HOTPLUG)
901 : unsigned long present_early_pages;
902 : #endif
903 : #ifdef CONFIG_CMA
904 : unsigned long cma_pages;
905 : #endif
906 :
907 : const char *name;
908 :
909 : #ifdef CONFIG_MEMORY_ISOLATION
910 : /*
911 : * Number of isolated pageblock. It is used to solve incorrect
912 : * freepage counting problem due to racy retrieving migratetype
913 : * of pageblock. Protected by zone->lock.
914 : */
915 : unsigned long nr_isolate_pageblock;
916 : #endif
917 :
918 : #ifdef CONFIG_MEMORY_HOTPLUG
919 : /* see spanned/present_pages for more description */
920 : seqlock_t span_seqlock;
921 : #endif
922 :
923 : int initialized;
924 :
925 : /* Write-intensive fields used from the page allocator */
926 : CACHELINE_PADDING(_pad1_);
927 :
928 : /* free areas of different sizes */
929 : struct free_area free_area[MAX_ORDER + 1];
930 :
931 : #ifdef CONFIG_UNACCEPTED_MEMORY
932 : /* Pages to be accepted. All pages on the list are MAX_ORDER */
933 : struct list_head unaccepted_pages;
934 : #endif
935 :
936 : /* zone flags, see below */
937 : unsigned long flags;
938 :
939 : /* Primarily protects free_area */
940 : spinlock_t lock;
941 :
942 : /* Write-intensive fields used by compaction and vmstats. */
943 : CACHELINE_PADDING(_pad2_);
944 :
945 : /*
946 : * When free pages are below this point, additional steps are taken
947 : * when reading the number of free pages to avoid per-cpu counter
948 : * drift allowing watermarks to be breached
949 : */
950 : unsigned long percpu_drift_mark;
951 :
952 : #if defined CONFIG_COMPACTION || defined CONFIG_CMA
953 : /* pfn where compaction free scanner should start */
954 : unsigned long compact_cached_free_pfn;
955 : /* pfn where compaction migration scanner should start */
956 : unsigned long compact_cached_migrate_pfn[ASYNC_AND_SYNC];
957 : unsigned long compact_init_migrate_pfn;
958 : unsigned long compact_init_free_pfn;
959 : #endif
960 :
961 : #ifdef CONFIG_COMPACTION
962 : /*
963 : * On compaction failure, 1<<compact_defer_shift compactions
964 : * are skipped before trying again. The number attempted since
965 : * last failure is tracked with compact_considered.
966 : * compact_order_failed is the minimum compaction failed order.
967 : */
968 : unsigned int compact_considered;
969 : unsigned int compact_defer_shift;
970 : int compact_order_failed;
971 : #endif
972 :
973 : #if defined CONFIG_COMPACTION || defined CONFIG_CMA
974 : /* Set to true when the PG_migrate_skip bits should be cleared */
975 : bool compact_blockskip_flush;
976 : #endif
977 :
978 : bool contiguous;
979 :
980 : CACHELINE_PADDING(_pad3_);
981 : /* Zone statistics */
982 : atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
983 : atomic_long_t vm_numa_event[NR_VM_NUMA_EVENT_ITEMS];
984 : } ____cacheline_internodealigned_in_smp;
985 :
986 : enum pgdat_flags {
987 : PGDAT_DIRTY, /* reclaim scanning has recently found
988 : * many dirty file pages at the tail
989 : * of the LRU.
990 : */
991 : PGDAT_WRITEBACK, /* reclaim scanning has recently found
992 : * many pages under writeback
993 : */
994 : PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */
995 : };
996 :
997 : enum zone_flags {
998 : ZONE_BOOSTED_WATERMARK, /* zone recently boosted watermarks.
999 : * Cleared when kswapd is woken.
1000 : */
1001 : ZONE_RECLAIM_ACTIVE, /* kswapd may be scanning the zone. */
1002 : };
1003 :
1004 : static inline unsigned long zone_managed_pages(struct zone *zone)
1005 : {
1006 : return (unsigned long)atomic_long_read(&zone->managed_pages);
1007 : }
1008 :
1009 : static inline unsigned long zone_cma_pages(struct zone *zone)
1010 : {
1011 : #ifdef CONFIG_CMA
1012 : return zone->cma_pages;
1013 : #else
1014 : return 0;
1015 : #endif
1016 : }
1017 :
1018 : static inline unsigned long zone_end_pfn(const struct zone *zone)
1019 : {
1020 : return zone->zone_start_pfn + zone->spanned_pages;
1021 : }
1022 :
1023 : static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)
1024 : {
1025 : return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone);
1026 : }
1027 :
1028 : static inline bool zone_is_initialized(struct zone *zone)
1029 : {
1030 : return zone->initialized;
1031 : }
1032 :
1033 : static inline bool zone_is_empty(struct zone *zone)
1034 : {
1035 : return zone->spanned_pages == 0;
1036 : }
1037 :
1038 : #ifndef BUILD_VDSO32_64
1039 : /*
1040 : * The zone field is never updated after free_area_init_core()
1041 : * sets it, so none of the operations on it need to be atomic.
1042 : */
1043 :
1044 : /* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_CPUPID] | ... | FLAGS | */
1045 : #define SECTIONS_PGOFF ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
1046 : #define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH)
1047 : #define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH)
1048 : #define LAST_CPUPID_PGOFF (ZONES_PGOFF - LAST_CPUPID_WIDTH)
1049 : #define KASAN_TAG_PGOFF (LAST_CPUPID_PGOFF - KASAN_TAG_WIDTH)
1050 : #define LRU_GEN_PGOFF (KASAN_TAG_PGOFF - LRU_GEN_WIDTH)
1051 : #define LRU_REFS_PGOFF (LRU_GEN_PGOFF - LRU_REFS_WIDTH)
1052 :
1053 : /*
1054 : * Define the bit shifts to access each section. For non-existent
1055 : * sections we define the shift as 0; that plus a 0 mask ensures
1056 : * the compiler will optimise away reference to them.
1057 : */
1058 : #define SECTIONS_PGSHIFT (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
1059 : #define NODES_PGSHIFT (NODES_PGOFF * (NODES_WIDTH != 0))
1060 : #define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_WIDTH != 0))
1061 : #define LAST_CPUPID_PGSHIFT (LAST_CPUPID_PGOFF * (LAST_CPUPID_WIDTH != 0))
1062 : #define KASAN_TAG_PGSHIFT (KASAN_TAG_PGOFF * (KASAN_TAG_WIDTH != 0))
1063 :
1064 : /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */
1065 : #ifdef NODE_NOT_IN_PAGE_FLAGS
1066 : #define ZONEID_SHIFT (SECTIONS_SHIFT + ZONES_SHIFT)
1067 : #define ZONEID_PGOFF ((SECTIONS_PGOFF < ZONES_PGOFF) ? \
1068 : SECTIONS_PGOFF : ZONES_PGOFF)
1069 : #else
1070 : #define ZONEID_SHIFT (NODES_SHIFT + ZONES_SHIFT)
1071 : #define ZONEID_PGOFF ((NODES_PGOFF < ZONES_PGOFF) ? \
1072 : NODES_PGOFF : ZONES_PGOFF)
1073 : #endif
1074 :
1075 : #define ZONEID_PGSHIFT (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
1076 :
1077 : #define ZONES_MASK ((1UL << ZONES_WIDTH) - 1)
1078 : #define NODES_MASK ((1UL << NODES_WIDTH) - 1)
1079 : #define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1)
1080 : #define LAST_CPUPID_MASK ((1UL << LAST_CPUPID_SHIFT) - 1)
1081 : #define KASAN_TAG_MASK ((1UL << KASAN_TAG_WIDTH) - 1)
1082 : #define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1)
1083 :
1084 : static inline enum zone_type page_zonenum(const struct page *page)
1085 : {
1086 149445070 : ASSERT_EXCLUSIVE_BITS(page->flags, ZONES_MASK << ZONES_PGSHIFT);
1087 149445070 : return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
1088 : }
1089 :
1090 : static inline enum zone_type folio_zonenum(const struct folio *folio)
1091 : {
1092 : return page_zonenum(&folio->page);
1093 : }
1094 :
1095 : #ifdef CONFIG_ZONE_DEVICE
1096 : static inline bool is_zone_device_page(const struct page *page)
1097 : {
1098 : return page_zonenum(page) == ZONE_DEVICE;
1099 : }
1100 :
1101 : /*
1102 : * Consecutive zone device pages should not be merged into the same sgl
1103 : * or bvec segment with other types of pages or if they belong to different
1104 : * pgmaps. Otherwise getting the pgmap of a given segment is not possible
1105 : * without scanning the entire segment. This helper returns true either if
1106 : * both pages are not zone device pages or both pages are zone device pages
1107 : * with the same pgmap.
1108 : */
1109 : static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
1110 : const struct page *b)
1111 : {
1112 : if (is_zone_device_page(a) != is_zone_device_page(b))
1113 : return false;
1114 : if (!is_zone_device_page(a))
1115 : return true;
1116 : return a->pgmap == b->pgmap;
1117 : }
1118 :
1119 : extern void memmap_init_zone_device(struct zone *, unsigned long,
1120 : unsigned long, struct dev_pagemap *);
1121 : #else
1122 : static inline bool is_zone_device_page(const struct page *page)
1123 : {
1124 : return false;
1125 : }
1126 : static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
1127 : const struct page *b)
1128 : {
1129 : return true;
1130 : }
1131 : #endif
1132 :
1133 : static inline bool folio_is_zone_device(const struct folio *folio)
1134 : {
1135 : return is_zone_device_page(&folio->page);
1136 : }
1137 :
1138 : static inline bool is_zone_movable_page(const struct page *page)
1139 : {
1140 : return page_zonenum(page) == ZONE_MOVABLE;
1141 : }
1142 :
1143 : static inline bool folio_is_zone_movable(const struct folio *folio)
1144 : {
1145 : return folio_zonenum(folio) == ZONE_MOVABLE;
1146 : }
1147 : #endif
1148 :
1149 : /*
1150 : * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty
1151 : * intersection with the given zone
1152 : */
1153 : static inline bool zone_intersects(struct zone *zone,
1154 : unsigned long start_pfn, unsigned long nr_pages)
1155 : {
1156 : if (zone_is_empty(zone))
1157 : return false;
1158 : if (start_pfn >= zone_end_pfn(zone) ||
1159 : start_pfn + nr_pages <= zone->zone_start_pfn)
1160 : return false;
1161 :
1162 : return true;
1163 : }
1164 :
1165 : /*
1166 : * The "priority" of VM scanning is how much of the queues we will scan in one
1167 : * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
1168 : * queues ("queue_length >> 12") during an aging round.
1169 : */
1170 : #define DEF_PRIORITY 12
1171 :
1172 : /* Maximum number of zones on a zonelist */
1173 : #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
1174 :
1175 : enum {
1176 : ZONELIST_FALLBACK, /* zonelist with fallback */
1177 : #ifdef CONFIG_NUMA
1178 : /*
1179 : * The NUMA zonelists are doubled because we need zonelists that
1180 : * restrict the allocations to a single node for __GFP_THISNODE.
1181 : */
1182 : ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */
1183 : #endif
1184 : MAX_ZONELISTS
1185 : };
1186 :
1187 : /*
1188 : * This struct contains information about a zone in a zonelist. It is stored
1189 : * here to avoid dereferences into large structures and lookups of tables
1190 : */
1191 : struct zoneref {
1192 : struct zone *zone; /* Pointer to actual zone */
1193 : int zone_idx; /* zone_idx(zoneref->zone) */
1194 : };
1195 :
1196 : /*
1197 : * One allocation request operates on a zonelist. A zonelist
1198 : * is a list of zones, the first one is the 'goal' of the
1199 : * allocation, the other zones are fallback zones, in decreasing
1200 : * priority.
1201 : *
1202 : * To speed the reading of the zonelist, the zonerefs contain the zone index
1203 : * of the entry being read. Helper functions to access information given
1204 : * a struct zoneref are
1205 : *
1206 : * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
1207 : * zonelist_zone_idx() - Return the index of the zone for an entry
1208 : * zonelist_node_idx() - Return the index of the node for an entry
1209 : */
1210 : struct zonelist {
1211 : struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
1212 : };
1213 :
1214 : /*
1215 : * The array of struct pages for flatmem.
1216 : * It must be declared for SPARSEMEM as well because there are configurations
1217 : * that rely on that.
1218 : */
1219 : extern struct page *mem_map;
1220 :
1221 : #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1222 : struct deferred_split {
1223 : spinlock_t split_queue_lock;
1224 : struct list_head split_queue;
1225 : unsigned long split_queue_len;
1226 : };
1227 : #endif
1228 :
1229 : #ifdef CONFIG_MEMORY_FAILURE
1230 : /*
1231 : * Per NUMA node memory failure handling statistics.
1232 : */
1233 : struct memory_failure_stats {
1234 : /*
1235 : * Number of raw pages poisoned.
1236 : * Cases not accounted: memory outside kernel control, offline page,
1237 : * arch-specific memory_failure (SGX), hwpoison_filter() filtered
1238 : * error events, and unpoison actions from hwpoison_unpoison.
1239 : */
1240 : unsigned long total;
1241 : /*
1242 : * Recovery results of poisoned raw pages handled by memory_failure,
1243 : * in sync with mf_result.
1244 : * total = ignored + failed + delayed + recovered.
1245 : * total * PAGE_SIZE * #nodes = /proc/meminfo/HardwareCorrupted.
1246 : */
1247 : unsigned long ignored;
1248 : unsigned long failed;
1249 : unsigned long delayed;
1250 : unsigned long recovered;
1251 : };
1252 : #endif
1253 :
1254 : /*
1255 : * On NUMA machines, each NUMA node would have a pg_data_t to describe
1256 : * it's memory layout. On UMA machines there is a single pglist_data which
1257 : * describes the whole memory.
1258 : *
1259 : * Memory statistics and page replacement data structures are maintained on a
1260 : * per-zone basis.
1261 : */
1262 : typedef struct pglist_data {
1263 : /*
1264 : * node_zones contains just the zones for THIS node. Not all of the
1265 : * zones may be populated, but it is the full list. It is referenced by
1266 : * this node's node_zonelists as well as other node's node_zonelists.
1267 : */
1268 : struct zone node_zones[MAX_NR_ZONES];
1269 :
1270 : /*
1271 : * node_zonelists contains references to all zones in all nodes.
1272 : * Generally the first zones will be references to this node's
1273 : * node_zones.
1274 : */
1275 : struct zonelist node_zonelists[MAX_ZONELISTS];
1276 :
1277 : int nr_zones; /* number of populated zones in this node */
1278 : #ifdef CONFIG_FLATMEM /* means !SPARSEMEM */
1279 : struct page *node_mem_map;
1280 : #ifdef CONFIG_PAGE_EXTENSION
1281 : struct page_ext *node_page_ext;
1282 : #endif
1283 : #endif
1284 : #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
1285 : /*
1286 : * Must be held any time you expect node_start_pfn,
1287 : * node_present_pages, node_spanned_pages or nr_zones to stay constant.
1288 : * Also synchronizes pgdat->first_deferred_pfn during deferred page
1289 : * init.
1290 : *
1291 : * pgdat_resize_lock() and pgdat_resize_unlock() are provided to
1292 : * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG
1293 : * or CONFIG_DEFERRED_STRUCT_PAGE_INIT.
1294 : *
1295 : * Nests above zone->lock and zone->span_seqlock
1296 : */
1297 : spinlock_t node_size_lock;
1298 : #endif
1299 : unsigned long node_start_pfn;
1300 : unsigned long node_present_pages; /* total number of physical pages */
1301 : unsigned long node_spanned_pages; /* total size of physical page
1302 : range, including holes */
1303 : int node_id;
1304 : wait_queue_head_t kswapd_wait;
1305 : wait_queue_head_t pfmemalloc_wait;
1306 :
1307 : /* workqueues for throttling reclaim for different reasons. */
1308 : wait_queue_head_t reclaim_wait[NR_VMSCAN_THROTTLE];
1309 :
1310 : atomic_t nr_writeback_throttled;/* nr of writeback-throttled tasks */
1311 : unsigned long nr_reclaim_start; /* nr pages written while throttled
1312 : * when throttling started. */
1313 : #ifdef CONFIG_MEMORY_HOTPLUG
1314 : struct mutex kswapd_lock;
1315 : #endif
1316 : struct task_struct *kswapd; /* Protected by kswapd_lock */
1317 : int kswapd_order;
1318 : enum zone_type kswapd_highest_zoneidx;
1319 :
1320 : int kswapd_failures; /* Number of 'reclaimed == 0' runs */
1321 :
1322 : #ifdef CONFIG_COMPACTION
1323 : int kcompactd_max_order;
1324 : enum zone_type kcompactd_highest_zoneidx;
1325 : wait_queue_head_t kcompactd_wait;
1326 : struct task_struct *kcompactd;
1327 : bool proactive_compact_trigger;
1328 : #endif
1329 : /*
1330 : * This is a per-node reserve of pages that are not available
1331 : * to userspace allocations.
1332 : */
1333 : unsigned long totalreserve_pages;
1334 :
1335 : #ifdef CONFIG_NUMA
1336 : /*
1337 : * node reclaim becomes active if more unmapped pages exist.
1338 : */
1339 : unsigned long min_unmapped_pages;
1340 : unsigned long min_slab_pages;
1341 : #endif /* CONFIG_NUMA */
1342 :
1343 : /* Write-intensive fields used by page reclaim */
1344 : CACHELINE_PADDING(_pad1_);
1345 :
1346 : #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1347 : /*
1348 : * If memory initialisation on large machines is deferred then this
1349 : * is the first PFN that needs to be initialised.
1350 : */
1351 : unsigned long first_deferred_pfn;
1352 : #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1353 :
1354 : #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1355 : struct deferred_split deferred_split_queue;
1356 : #endif
1357 :
1358 : #ifdef CONFIG_NUMA_BALANCING
1359 : /* start time in ms of current promote rate limit period */
1360 : unsigned int nbp_rl_start;
1361 : /* number of promote candidate pages at start time of current rate limit period */
1362 : unsigned long nbp_rl_nr_cand;
1363 : /* promote threshold in ms */
1364 : unsigned int nbp_threshold;
1365 : /* start time in ms of current promote threshold adjustment period */
1366 : unsigned int nbp_th_start;
1367 : /*
1368 : * number of promote candidate pages at start time of current promote
1369 : * threshold adjustment period
1370 : */
1371 : unsigned long nbp_th_nr_cand;
1372 : #endif
1373 : /* Fields commonly accessed by the page reclaim scanner */
1374 :
1375 : /*
1376 : * NOTE: THIS IS UNUSED IF MEMCG IS ENABLED.
1377 : *
1378 : * Use mem_cgroup_lruvec() to look up lruvecs.
1379 : */
1380 : struct lruvec __lruvec;
1381 :
1382 : unsigned long flags;
1383 :
1384 : #ifdef CONFIG_LRU_GEN
1385 : /* kswap mm walk data */
1386 : struct lru_gen_mm_walk mm_walk;
1387 : /* lru_gen_folio list */
1388 : struct lru_gen_memcg memcg_lru;
1389 : #endif
1390 :
1391 : CACHELINE_PADDING(_pad2_);
1392 :
1393 : /* Per-node vmstats */
1394 : struct per_cpu_nodestat __percpu *per_cpu_nodestats;
1395 : atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS];
1396 : #ifdef CONFIG_NUMA
1397 : struct memory_tier __rcu *memtier;
1398 : #endif
1399 : #ifdef CONFIG_MEMORY_FAILURE
1400 : struct memory_failure_stats mf_stats;
1401 : #endif
1402 : } pg_data_t;
1403 :
1404 : #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
1405 : #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
1406 :
1407 : #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn)
1408 : #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))
1409 :
1410 : static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat)
1411 : {
1412 : return pgdat->node_start_pfn + pgdat->node_spanned_pages;
1413 : }
1414 :
1415 : #include <linux/memory_hotplug.h>
1416 :
1417 : void build_all_zonelists(pg_data_t *pgdat);
1418 : void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order,
1419 : enum zone_type highest_zoneidx);
1420 : bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
1421 : int highest_zoneidx, unsigned int alloc_flags,
1422 : long free_pages);
1423 : bool zone_watermark_ok(struct zone *z, unsigned int order,
1424 : unsigned long mark, int highest_zoneidx,
1425 : unsigned int alloc_flags);
1426 : bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
1427 : unsigned long mark, int highest_zoneidx);
1428 : /*
1429 : * Memory initialization context, use to differentiate memory added by
1430 : * the platform statically or via memory hotplug interface.
1431 : */
1432 : enum meminit_context {
1433 : MEMINIT_EARLY,
1434 : MEMINIT_HOTPLUG,
1435 : };
1436 :
1437 : extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
1438 : unsigned long size);
1439 :
1440 : extern void lruvec_init(struct lruvec *lruvec);
1441 :
1442 : static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec)
1443 : {
1444 : #ifdef CONFIG_MEMCG
1445 : return lruvec->pgdat;
1446 : #else
1447 : return container_of(lruvec, struct pglist_data, __lruvec);
1448 : #endif
1449 : }
1450 :
1451 : #ifdef CONFIG_HAVE_MEMORYLESS_NODES
1452 : int local_memory_node(int node_id);
1453 : #else
1454 : static inline int local_memory_node(int node_id) { return node_id; };
1455 : #endif
1456 :
1457 : /*
1458 : * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
1459 : */
1460 : #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
1461 :
1462 : #ifdef CONFIG_ZONE_DEVICE
1463 : static inline bool zone_is_zone_device(struct zone *zone)
1464 : {
1465 : return zone_idx(zone) == ZONE_DEVICE;
1466 : }
1467 : #else
1468 : static inline bool zone_is_zone_device(struct zone *zone)
1469 : {
1470 : return false;
1471 : }
1472 : #endif
1473 :
1474 : /*
1475 : * Returns true if a zone has pages managed by the buddy allocator.
1476 : * All the reclaim decisions have to use this function rather than
1477 : * populated_zone(). If the whole zone is reserved then we can easily
1478 : * end up with populated_zone() && !managed_zone().
1479 : */
1480 : static inline bool managed_zone(struct zone *zone)
1481 : {
1482 : return zone_managed_pages(zone);
1483 : }
1484 :
1485 : /* Returns true if a zone has memory */
1486 : static inline bool populated_zone(struct zone *zone)
1487 : {
1488 129091756 : return zone->present_pages;
1489 : }
1490 :
1491 : #ifdef CONFIG_NUMA
1492 : static inline int zone_to_nid(struct zone *zone)
1493 : {
1494 : return zone->node;
1495 : }
1496 :
1497 : static inline void zone_set_nid(struct zone *zone, int nid)
1498 : {
1499 : zone->node = nid;
1500 : }
1501 : #else
1502 : static inline int zone_to_nid(struct zone *zone)
1503 : {
1504 : return 0;
1505 : }
1506 :
1507 : static inline void zone_set_nid(struct zone *zone, int nid) {}
1508 : #endif
1509 :
1510 : extern int movable_zone;
1511 :
1512 : static inline int is_highmem_idx(enum zone_type idx)
1513 : {
1514 : #ifdef CONFIG_HIGHMEM
1515 : return (idx == ZONE_HIGHMEM ||
1516 : (idx == ZONE_MOVABLE && movable_zone == ZONE_HIGHMEM));
1517 : #else
1518 : return 0;
1519 : #endif
1520 : }
1521 :
1522 : /**
1523 : * is_highmem - helper function to quickly check if a struct zone is a
1524 : * highmem zone or not. This is an attempt to keep references
1525 : * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
1526 : * @zone: pointer to struct zone variable
1527 : * Return: 1 for a highmem zone, 0 otherwise
1528 : */
1529 : static inline int is_highmem(struct zone *zone)
1530 : {
1531 : return is_highmem_idx(zone_idx(zone));
1532 : }
1533 :
1534 : #ifdef CONFIG_ZONE_DMA
1535 : bool has_managed_dma(void);
1536 : #else
1537 : static inline bool has_managed_dma(void)
1538 : {
1539 : return false;
1540 : }
1541 : #endif
1542 :
1543 :
1544 : #ifndef CONFIG_NUMA
1545 :
1546 : extern struct pglist_data contig_page_data;
1547 : static inline struct pglist_data *NODE_DATA(int nid)
1548 : {
1549 : return &contig_page_data;
1550 : }
1551 :
1552 : #else /* CONFIG_NUMA */
1553 :
1554 : #include <asm/mmzone.h>
1555 :
1556 : #endif /* !CONFIG_NUMA */
1557 :
1558 : extern struct pglist_data *first_online_pgdat(void);
1559 : extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
1560 : extern struct zone *next_zone(struct zone *zone);
1561 :
1562 : /**
1563 : * for_each_online_pgdat - helper macro to iterate over all online nodes
1564 : * @pgdat: pointer to a pg_data_t variable
1565 : */
1566 : #define for_each_online_pgdat(pgdat) \
1567 : for (pgdat = first_online_pgdat(); \
1568 : pgdat; \
1569 : pgdat = next_online_pgdat(pgdat))
1570 : /**
1571 : * for_each_zone - helper macro to iterate over all memory zones
1572 : * @zone: pointer to struct zone variable
1573 : *
1574 : * The user only needs to declare the zone variable, for_each_zone
1575 : * fills it in.
1576 : */
1577 : #define for_each_zone(zone) \
1578 : for (zone = (first_online_pgdat())->node_zones; \
1579 : zone; \
1580 : zone = next_zone(zone))
1581 :
1582 : #define for_each_populated_zone(zone) \
1583 : for (zone = (first_online_pgdat())->node_zones; \
1584 : zone; \
1585 : zone = next_zone(zone)) \
1586 : if (!populated_zone(zone)) \
1587 : ; /* do nothing */ \
1588 : else
1589 :
1590 : static inline struct zone *zonelist_zone(struct zoneref *zoneref)
1591 : {
1592 : return zoneref->zone;
1593 : }
1594 :
1595 : static inline int zonelist_zone_idx(struct zoneref *zoneref)
1596 : {
1597 : return zoneref->zone_idx;
1598 : }
1599 :
1600 : static inline int zonelist_node_idx(struct zoneref *zoneref)
1601 : {
1602 : return zone_to_nid(zoneref->zone);
1603 : }
1604 :
1605 : struct zoneref *__next_zones_zonelist(struct zoneref *z,
1606 : enum zone_type highest_zoneidx,
1607 : nodemask_t *nodes);
1608 :
1609 : /**
1610 : * 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
1611 : * @z: The cursor used as a starting point for the search
1612 : * @highest_zoneidx: The zone index of the highest zone to return
1613 : * @nodes: An optional nodemask to filter the zonelist with
1614 : *
1615 : * This function returns the next zone at or below a given zone index that is
1616 : * within the allowed nodemask using a cursor as the starting point for the
1617 : * search. The zoneref returned is a cursor that represents the current zone
1618 : * being examined. It should be advanced by one before calling
1619 : * next_zones_zonelist again.
1620 : *
1621 : * Return: the next zone at or below highest_zoneidx within the allowed
1622 : * nodemask using a cursor within a zonelist as a starting point
1623 : */
1624 : static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z,
1625 : enum zone_type highest_zoneidx,
1626 : nodemask_t *nodes)
1627 : {
1628 : if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx))
1629 : return z;
1630 : return __next_zones_zonelist(z, highest_zoneidx, nodes);
1631 : }
1632 :
1633 : /**
1634 : * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
1635 : * @zonelist: The zonelist to search for a suitable zone
1636 : * @highest_zoneidx: The zone index of the highest zone to return
1637 : * @nodes: An optional nodemask to filter the zonelist with
1638 : *
1639 : * This function returns the first zone at or below a given zone index that is
1640 : * within the allowed nodemask. The zoneref returned is a cursor that can be
1641 : * used to iterate the zonelist with next_zones_zonelist by advancing it by
1642 : * one before calling.
1643 : *
1644 : * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is
1645 : * never NULL). This may happen either genuinely, or due to concurrent nodemask
1646 : * update due to cpuset modification.
1647 : *
1648 : * Return: Zoneref pointer for the first suitable zone found
1649 : */
1650 : static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
1651 : enum zone_type highest_zoneidx,
1652 : nodemask_t *nodes)
1653 : {
1654 : return next_zones_zonelist(zonelist->_zonerefs,
1655 : highest_zoneidx, nodes);
1656 : }
1657 :
1658 : /**
1659 : * 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
1660 : * @zone: The current zone in the iterator
1661 : * @z: The current pointer within zonelist->_zonerefs being iterated
1662 : * @zlist: The zonelist being iterated
1663 : * @highidx: The zone index of the highest zone to return
1664 : * @nodemask: Nodemask allowed by the allocator
1665 : *
1666 : * This iterator iterates though all zones at or below a given zone index and
1667 : * within a given nodemask
1668 : */
1669 : #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
1670 : for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \
1671 : zone; \
1672 : z = next_zones_zonelist(++z, highidx, nodemask), \
1673 : zone = zonelist_zone(z))
1674 :
1675 : #define for_next_zone_zonelist_nodemask(zone, z, highidx, nodemask) \
1676 : for (zone = z->zone; \
1677 : zone; \
1678 : z = next_zones_zonelist(++z, highidx, nodemask), \
1679 : zone = zonelist_zone(z))
1680 :
1681 :
1682 : /**
1683 : * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
1684 : * @zone: The current zone in the iterator
1685 : * @z: The current pointer within zonelist->zones being iterated
1686 : * @zlist: The zonelist being iterated
1687 : * @highidx: The zone index of the highest zone to return
1688 : *
1689 : * This iterator iterates though all zones at or below a given zone index.
1690 : */
1691 : #define for_each_zone_zonelist(zone, z, zlist, highidx) \
1692 : for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
1693 :
1694 : /* Whether the 'nodes' are all movable nodes */
1695 : static inline bool movable_only_nodes(nodemask_t *nodes)
1696 : {
1697 : struct zonelist *zonelist;
1698 : struct zoneref *z;
1699 : int nid;
1700 :
1701 : if (nodes_empty(*nodes))
1702 : return false;
1703 :
1704 : /*
1705 : * We can chose arbitrary node from the nodemask to get a
1706 : * zonelist as they are interlinked. We just need to find
1707 : * at least one zone that can satisfy kernel allocations.
1708 : */
1709 : nid = first_node(*nodes);
1710 : zonelist = &NODE_DATA(nid)->node_zonelists[ZONELIST_FALLBACK];
1711 : z = first_zones_zonelist(zonelist, ZONE_NORMAL, nodes);
1712 : return (!z->zone) ? true : false;
1713 : }
1714 :
1715 :
1716 : #ifdef CONFIG_SPARSEMEM
1717 : #include <asm/sparsemem.h>
1718 : #endif
1719 :
1720 : #ifdef CONFIG_FLATMEM
1721 : #define pfn_to_nid(pfn) (0)
1722 : #endif
1723 :
1724 : #ifdef CONFIG_SPARSEMEM
1725 :
1726 : /*
1727 : * PA_SECTION_SHIFT physical address to/from section number
1728 : * PFN_SECTION_SHIFT pfn to/from section number
1729 : */
1730 : #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
1731 : #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
1732 :
1733 : #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
1734 :
1735 : #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
1736 : #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
1737 :
1738 : #define SECTION_BLOCKFLAGS_BITS \
1739 : ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
1740 :
1741 : #if (MAX_ORDER + PAGE_SHIFT) > SECTION_SIZE_BITS
1742 : #error Allocator MAX_ORDER exceeds SECTION_SIZE
1743 : #endif
1744 :
1745 : static inline unsigned long pfn_to_section_nr(unsigned long pfn)
1746 : {
1747 : return pfn >> PFN_SECTION_SHIFT;
1748 : }
1749 : static inline unsigned long section_nr_to_pfn(unsigned long sec)
1750 : {
1751 : return sec << PFN_SECTION_SHIFT;
1752 : }
1753 :
1754 : #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)
1755 : #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK)
1756 :
1757 : #define SUBSECTION_SHIFT 21
1758 : #define SUBSECTION_SIZE (1UL << SUBSECTION_SHIFT)
1759 :
1760 : #define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT)
1761 : #define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT)
1762 : #define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1))
1763 :
1764 : #if SUBSECTION_SHIFT > SECTION_SIZE_BITS
1765 : #error Subsection size exceeds section size
1766 : #else
1767 : #define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT))
1768 : #endif
1769 :
1770 : #define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION)
1771 : #define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK)
1772 :
1773 : struct mem_section_usage {
1774 : #ifdef CONFIG_SPARSEMEM_VMEMMAP
1775 : DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION);
1776 : #endif
1777 : /* See declaration of similar field in struct zone */
1778 : unsigned long pageblock_flags[0];
1779 : };
1780 :
1781 : void subsection_map_init(unsigned long pfn, unsigned long nr_pages);
1782 :
1783 : struct page;
1784 : struct page_ext;
1785 : struct mem_section {
1786 : /*
1787 : * This is, logically, a pointer to an array of struct
1788 : * pages. However, it is stored with some other magic.
1789 : * (see sparse.c::sparse_init_one_section())
1790 : *
1791 : * Additionally during early boot we encode node id of
1792 : * the location of the section here to guide allocation.
1793 : * (see sparse.c::memory_present())
1794 : *
1795 : * Making it a UL at least makes someone do a cast
1796 : * before using it wrong.
1797 : */
1798 : unsigned long section_mem_map;
1799 :
1800 : struct mem_section_usage *usage;
1801 : #ifdef CONFIG_PAGE_EXTENSION
1802 : /*
1803 : * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use
1804 : * section. (see page_ext.h about this.)
1805 : */
1806 : struct page_ext *page_ext;
1807 : unsigned long pad;
1808 : #endif
1809 : /*
1810 : * WARNING: mem_section must be a power-of-2 in size for the
1811 : * calculation and use of SECTION_ROOT_MASK to make sense.
1812 : */
1813 : };
1814 :
1815 : #ifdef CONFIG_SPARSEMEM_EXTREME
1816 : #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
1817 : #else
1818 : #define SECTIONS_PER_ROOT 1
1819 : #endif
1820 :
1821 : #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
1822 : #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT)
1823 : #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
1824 :
1825 : #ifdef CONFIG_SPARSEMEM_EXTREME
1826 : extern struct mem_section **mem_section;
1827 : #else
1828 : extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
1829 : #endif
1830 :
1831 : static inline unsigned long *section_to_usemap(struct mem_section *ms)
1832 : {
1833 : return ms->usage->pageblock_flags;
1834 : }
1835 :
1836 : static inline struct mem_section *__nr_to_section(unsigned long nr)
1837 : {
1838 : unsigned long root = SECTION_NR_TO_ROOT(nr);
1839 :
1840 : if (unlikely(root >= NR_SECTION_ROOTS))
1841 : return NULL;
1842 :
1843 : #ifdef CONFIG_SPARSEMEM_EXTREME
1844 : if (!mem_section || !mem_section[root])
1845 : return NULL;
1846 : #endif
1847 : return &mem_section[root][nr & SECTION_ROOT_MASK];
1848 : }
1849 : extern size_t mem_section_usage_size(void);
1850 :
1851 : /*
1852 : * We use the lower bits of the mem_map pointer to store
1853 : * a little bit of information. The pointer is calculated
1854 : * as mem_map - section_nr_to_pfn(pnum). The result is
1855 : * aligned to the minimum alignment of the two values:
1856 : * 1. All mem_map arrays are page-aligned.
1857 : * 2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT
1858 : * lowest bits. PFN_SECTION_SHIFT is arch-specific
1859 : * (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the
1860 : * worst combination is powerpc with 256k pages,
1861 : * which results in PFN_SECTION_SHIFT equal 6.
1862 : * To sum it up, at least 6 bits are available on all architectures.
1863 : * However, we can exceed 6 bits on some other architectures except
1864 : * powerpc (e.g. 15 bits are available on x86_64, 13 bits are available
1865 : * with the worst case of 64K pages on arm64) if we make sure the
1866 : * exceeded bit is not applicable to powerpc.
1867 : */
1868 : enum {
1869 : SECTION_MARKED_PRESENT_BIT,
1870 : SECTION_HAS_MEM_MAP_BIT,
1871 : SECTION_IS_ONLINE_BIT,
1872 : SECTION_IS_EARLY_BIT,
1873 : #ifdef CONFIG_ZONE_DEVICE
1874 : SECTION_TAINT_ZONE_DEVICE_BIT,
1875 : #endif
1876 : SECTION_MAP_LAST_BIT,
1877 : };
1878 :
1879 : #define SECTION_MARKED_PRESENT BIT(SECTION_MARKED_PRESENT_BIT)
1880 : #define SECTION_HAS_MEM_MAP BIT(SECTION_HAS_MEM_MAP_BIT)
1881 : #define SECTION_IS_ONLINE BIT(SECTION_IS_ONLINE_BIT)
1882 : #define SECTION_IS_EARLY BIT(SECTION_IS_EARLY_BIT)
1883 : #ifdef CONFIG_ZONE_DEVICE
1884 : #define SECTION_TAINT_ZONE_DEVICE BIT(SECTION_TAINT_ZONE_DEVICE_BIT)
1885 : #endif
1886 : #define SECTION_MAP_MASK (~(BIT(SECTION_MAP_LAST_BIT) - 1))
1887 : #define SECTION_NID_SHIFT SECTION_MAP_LAST_BIT
1888 :
1889 : static inline struct page *__section_mem_map_addr(struct mem_section *section)
1890 : {
1891 : unsigned long map = section->section_mem_map;
1892 : map &= SECTION_MAP_MASK;
1893 : return (struct page *)map;
1894 : }
1895 :
1896 : static inline int present_section(struct mem_section *section)
1897 : {
1898 : return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
1899 : }
1900 :
1901 : static inline int present_section_nr(unsigned long nr)
1902 : {
1903 : return present_section(__nr_to_section(nr));
1904 : }
1905 :
1906 : static inline int valid_section(struct mem_section *section)
1907 : {
1908 : return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
1909 : }
1910 :
1911 : static inline int early_section(struct mem_section *section)
1912 : {
1913 : return (section && (section->section_mem_map & SECTION_IS_EARLY));
1914 : }
1915 :
1916 : static inline int valid_section_nr(unsigned long nr)
1917 : {
1918 : return valid_section(__nr_to_section(nr));
1919 : }
1920 :
1921 : static inline int online_section(struct mem_section *section)
1922 : {
1923 : return (section && (section->section_mem_map & SECTION_IS_ONLINE));
1924 : }
1925 :
1926 : #ifdef CONFIG_ZONE_DEVICE
1927 : static inline int online_device_section(struct mem_section *section)
1928 : {
1929 : unsigned long flags = SECTION_IS_ONLINE | SECTION_TAINT_ZONE_DEVICE;
1930 :
1931 : return section && ((section->section_mem_map & flags) == flags);
1932 : }
1933 : #else
1934 : static inline int online_device_section(struct mem_section *section)
1935 : {
1936 : return 0;
1937 : }
1938 : #endif
1939 :
1940 : static inline int online_section_nr(unsigned long nr)
1941 : {
1942 : return online_section(__nr_to_section(nr));
1943 : }
1944 :
1945 : #ifdef CONFIG_MEMORY_HOTPLUG
1946 : void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
1947 : void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
1948 : #endif
1949 :
1950 : static inline struct mem_section *__pfn_to_section(unsigned long pfn)
1951 : {
1952 : return __nr_to_section(pfn_to_section_nr(pfn));
1953 : }
1954 :
1955 : extern unsigned long __highest_present_section_nr;
1956 :
1957 : static inline int subsection_map_index(unsigned long pfn)
1958 : {
1959 : return (pfn & ~(PAGE_SECTION_MASK)) / PAGES_PER_SUBSECTION;
1960 : }
1961 :
1962 : #ifdef CONFIG_SPARSEMEM_VMEMMAP
1963 : static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
1964 : {
1965 : int idx = subsection_map_index(pfn);
1966 :
1967 : return test_bit(idx, ms->usage->subsection_map);
1968 : }
1969 : #else
1970 : static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
1971 : {
1972 : return 1;
1973 : }
1974 : #endif
1975 :
1976 : #ifndef CONFIG_HAVE_ARCH_PFN_VALID
1977 : /**
1978 : * pfn_valid - check if there is a valid memory map entry for a PFN
1979 : * @pfn: the page frame number to check
1980 : *
1981 : * Check if there is a valid memory map entry aka struct page for the @pfn.
1982 : * Note, that availability of the memory map entry does not imply that
1983 : * there is actual usable memory at that @pfn. The struct page may
1984 : * represent a hole or an unusable page frame.
1985 : *
1986 : * Return: 1 for PFNs that have memory map entries and 0 otherwise
1987 : */
1988 : static inline int pfn_valid(unsigned long pfn)
1989 : {
1990 : struct mem_section *ms;
1991 :
1992 : /*
1993 : * Ensure the upper PAGE_SHIFT bits are clear in the
1994 : * pfn. Else it might lead to false positives when
1995 : * some of the upper bits are set, but the lower bits
1996 : * match a valid pfn.
1997 : */
1998 : if (PHYS_PFN(PFN_PHYS(pfn)) != pfn)
1999 : return 0;
2000 :
2001 : if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
2002 : return 0;
2003 : ms = __pfn_to_section(pfn);
2004 : if (!valid_section(ms))
2005 : return 0;
2006 : /*
2007 : * Traditionally early sections always returned pfn_valid() for
2008 : * the entire section-sized span.
2009 : */
2010 : return early_section(ms) || pfn_section_valid(ms, pfn);
2011 : }
2012 : #endif
2013 :
2014 : static inline int pfn_in_present_section(unsigned long pfn)
2015 : {
2016 : if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
2017 : return 0;
2018 : return present_section(__pfn_to_section(pfn));
2019 : }
2020 :
2021 : static inline unsigned long next_present_section_nr(unsigned long section_nr)
2022 : {
2023 : while (++section_nr <= __highest_present_section_nr) {
2024 : if (present_section_nr(section_nr))
2025 : return section_nr;
2026 : }
2027 :
2028 : return -1;
2029 : }
2030 :
2031 : /*
2032 : * These are _only_ used during initialisation, therefore they
2033 : * can use __initdata ... They could have names to indicate
2034 : * this restriction.
2035 : */
2036 : #ifdef CONFIG_NUMA
2037 : #define pfn_to_nid(pfn) \
2038 : ({ \
2039 : unsigned long __pfn_to_nid_pfn = (pfn); \
2040 : page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
2041 : })
2042 : #else
2043 : #define pfn_to_nid(pfn) (0)
2044 : #endif
2045 :
2046 : void sparse_init(void);
2047 : #else
2048 : #define sparse_init() do {} while (0)
2049 : #define sparse_index_init(_sec, _nid) do {} while (0)
2050 : #define pfn_in_present_section pfn_valid
2051 : #define subsection_map_init(_pfn, _nr_pages) do {} while (0)
2052 : #endif /* CONFIG_SPARSEMEM */
2053 :
2054 : #endif /* !__GENERATING_BOUNDS.H */
2055 : #endif /* !__ASSEMBLY__ */
2056 : #endif /* _LINUX_MMZONE_H */
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