1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_MMZONE_H
3 #define _LINUX_MMZONE_H
6 #ifndef __GENERATING_BOUNDS_H
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 <linux/zswap.h>
28 /* Free memory management - zoned buddy allocator. */
29 #ifndef CONFIG_ARCH_FORCE_MAX_ORDER
30 #define MAX_PAGE_ORDER 10
32 #define MAX_PAGE_ORDER CONFIG_ARCH_FORCE_MAX_ORDER
34 #define MAX_ORDER_NR_PAGES (1 << MAX_PAGE_ORDER)
36 #define IS_MAX_ORDER_ALIGNED(pfn) IS_ALIGNED(pfn, MAX_ORDER_NR_PAGES)
38 #define NR_PAGE_ORDERS (MAX_PAGE_ORDER + 1)
41 * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
42 * costly to service. That is between allocation orders which should
43 * coalesce naturally under reasonable reclaim pressure and those which
46 #define PAGE_ALLOC_COSTLY_ORDER 3
52 MIGRATE_PCPTYPES, /* the number of types on the pcp lists */
53 MIGRATE_HIGHATOMIC = MIGRATE_PCPTYPES,
56 * MIGRATE_CMA migration type is designed to mimic the way
57 * ZONE_MOVABLE works. Only movable pages can be allocated
58 * from MIGRATE_CMA pageblocks and page allocator never
59 * implicitly change migration type of MIGRATE_CMA pageblock.
61 * The way to use it is to change migratetype of a range of
62 * pageblocks to MIGRATE_CMA which can be done by
63 * __free_pageblock_cma() function.
67 #ifdef CONFIG_MEMORY_ISOLATION
68 MIGRATE_ISOLATE, /* can't allocate from here */
73 /* In mm/page_alloc.c; keep in sync also with show_migration_types() there */
74 extern const char * const migratetype_names[MIGRATE_TYPES];
77 # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
78 # define is_migrate_cma_page(_page) (get_pageblock_migratetype(_page) == MIGRATE_CMA)
79 # define is_migrate_cma_folio(folio, pfn) (MIGRATE_CMA == \
80 get_pfnblock_flags_mask(&folio->page, pfn, MIGRATETYPE_MASK))
82 # define is_migrate_cma(migratetype) false
83 # define is_migrate_cma_page(_page) false
84 # define is_migrate_cma_folio(folio, pfn) false
87 static inline bool is_migrate_movable(int mt)
89 return is_migrate_cma(mt) || mt == MIGRATE_MOVABLE;
93 * Check whether a migratetype can be merged with another migratetype.
95 * It is only mergeable when it can fall back to other migratetypes for
96 * allocation. See fallbacks[MIGRATE_TYPES][3] in page_alloc.c.
98 static inline bool migratetype_is_mergeable(int mt)
100 return mt < MIGRATE_PCPTYPES;
103 #define for_each_migratetype_order(order, type) \
104 for (order = 0; order < NR_PAGE_ORDERS; order++) \
105 for (type = 0; type < MIGRATE_TYPES; type++)
107 extern int page_group_by_mobility_disabled;
109 #define MIGRATETYPE_MASK ((1UL << PB_migratetype_bits) - 1)
111 #define get_pageblock_migratetype(page) \
112 get_pfnblock_flags_mask(page, page_to_pfn(page), MIGRATETYPE_MASK)
114 #define folio_migratetype(folio) \
115 get_pfnblock_flags_mask(&folio->page, folio_pfn(folio), \
118 struct list_head free_list[MIGRATE_TYPES];
119 unsigned long nr_free;
125 enum numa_stat_item {
126 NUMA_HIT, /* allocated in intended node */
127 NUMA_MISS, /* allocated in non intended node */
128 NUMA_FOREIGN, /* was intended here, hit elsewhere */
129 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
130 NUMA_LOCAL, /* allocation from local node */
131 NUMA_OTHER, /* allocation from other node */
132 NR_VM_NUMA_EVENT_ITEMS
135 #define NR_VM_NUMA_EVENT_ITEMS 0
138 enum zone_stat_item {
139 /* First 128 byte cacheline (assuming 64 bit words) */
141 NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */
142 NR_ZONE_INACTIVE_ANON = NR_ZONE_LRU_BASE,
144 NR_ZONE_INACTIVE_FILE,
147 NR_ZONE_WRITE_PENDING, /* Count of dirty, writeback and unstable pages */
148 NR_MLOCK, /* mlock()ed pages found and moved off LRU */
149 /* Second 128 byte cacheline */
151 #if IS_ENABLED(CONFIG_ZSMALLOC)
152 NR_ZSPAGES, /* allocated in zsmalloc */
155 #ifdef CONFIG_UNACCEPTED_MEMORY
158 NR_VM_ZONE_STAT_ITEMS };
160 enum node_stat_item {
162 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
163 NR_ACTIVE_ANON, /* " " " " " */
164 NR_INACTIVE_FILE, /* " " " " " */
165 NR_ACTIVE_FILE, /* " " " " " */
166 NR_UNEVICTABLE, /* " " " " " */
167 NR_SLAB_RECLAIMABLE_B,
168 NR_SLAB_UNRECLAIMABLE_B,
169 NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */
170 NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
172 WORKINGSET_REFAULT_BASE,
173 WORKINGSET_REFAULT_ANON = WORKINGSET_REFAULT_BASE,
174 WORKINGSET_REFAULT_FILE,
175 WORKINGSET_ACTIVATE_BASE,
176 WORKINGSET_ACTIVATE_ANON = WORKINGSET_ACTIVATE_BASE,
177 WORKINGSET_ACTIVATE_FILE,
178 WORKINGSET_RESTORE_BASE,
179 WORKINGSET_RESTORE_ANON = WORKINGSET_RESTORE_BASE,
180 WORKINGSET_RESTORE_FILE,
181 WORKINGSET_NODERECLAIM,
182 NR_ANON_MAPPED, /* Mapped anonymous pages */
183 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
184 only modified from process context */
188 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
189 NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */
196 NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */
197 NR_DIRTIED, /* page dirtyings since bootup */
198 NR_WRITTEN, /* page writings since bootup */
199 NR_THROTTLED_WRITTEN, /* NR_WRITTEN while reclaim throttled */
200 NR_KERNEL_MISC_RECLAIMABLE, /* reclaimable non-slab kernel pages */
201 NR_FOLL_PIN_ACQUIRED, /* via: pin_user_page(), gup flag: FOLL_PIN */
202 NR_FOLL_PIN_RELEASED, /* pages returned via unpin_user_page() */
203 NR_KERNEL_STACK_KB, /* measured in KiB */
204 #if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
205 NR_KERNEL_SCS_KB, /* measured in KiB */
207 NR_PAGETABLE, /* used for pagetables */
208 NR_SECONDARY_PAGETABLE, /* secondary pagetables, KVM & IOMMU */
209 #ifdef CONFIG_IOMMU_SUPPORT
210 NR_IOMMU_PAGES, /* # of pages allocated by IOMMU */
215 #ifdef CONFIG_NUMA_BALANCING
216 PGPROMOTE_SUCCESS, /* promote successfully */
217 PGPROMOTE_CANDIDATE, /* candidate pages to promote */
219 /* PGDEMOTE_*: pages demoted */
223 NR_VM_NODE_STAT_ITEMS
227 * Returns true if the item should be printed in THPs (/proc/vmstat
228 * currently prints number of anon, file and shmem THPs. But the item
229 * is charged in pages).
231 static __always_inline bool vmstat_item_print_in_thp(enum node_stat_item item)
233 if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
236 return item == NR_ANON_THPS ||
237 item == NR_FILE_THPS ||
238 item == NR_SHMEM_THPS ||
239 item == NR_SHMEM_PMDMAPPED ||
240 item == NR_FILE_PMDMAPPED;
244 * Returns true if the value is measured in bytes (most vmstat values are
245 * measured in pages). This defines the API part, the internal representation
246 * might be different.
248 static __always_inline bool vmstat_item_in_bytes(int idx)
251 * Global and per-node slab counters track slab pages.
252 * It's expected that changes are multiples of PAGE_SIZE.
253 * Internally values are stored in pages.
255 * Per-memcg and per-lruvec counters track memory, consumed
256 * by individual slab objects. These counters are actually
259 return (idx == NR_SLAB_RECLAIMABLE_B ||
260 idx == NR_SLAB_UNRECLAIMABLE_B);
264 * We do arithmetic on the LRU lists in various places in the code,
265 * so it is important to keep the active lists LRU_ACTIVE higher in
266 * the array than the corresponding inactive lists, and to keep
267 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
269 * This has to be kept in sync with the statistics in zone_stat_item
270 * above and the descriptions in vmstat_text in mm/vmstat.c
277 LRU_INACTIVE_ANON = LRU_BASE,
278 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
279 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
280 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
285 enum vmscan_throttle_state {
286 VMSCAN_THROTTLE_WRITEBACK,
287 VMSCAN_THROTTLE_ISOLATED,
288 VMSCAN_THROTTLE_NOPROGRESS,
289 VMSCAN_THROTTLE_CONGESTED,
293 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++)
295 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++)
297 static inline bool is_file_lru(enum lru_list lru)
299 return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE);
302 static inline bool is_active_lru(enum lru_list lru)
304 return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE);
307 #define WORKINGSET_ANON 0
308 #define WORKINGSET_FILE 1
309 #define ANON_AND_FILE 2
313 * An lruvec has many dirty pages backed by a congested BDI:
314 * 1. LRUVEC_CGROUP_CONGESTED is set by cgroup-level reclaim.
315 * It can be cleared by cgroup reclaim or kswapd.
316 * 2. LRUVEC_NODE_CONGESTED is set by kswapd node-level reclaim.
317 * It can only be cleared by kswapd.
319 * Essentially, kswapd can unthrottle an lruvec throttled by cgroup
320 * reclaim, but not vice versa. This only applies to the root cgroup.
321 * The goal is to prevent cgroup reclaim on the root cgroup (e.g.
322 * memory.reclaim) to unthrottle an unbalanced node (that was throttled
325 LRUVEC_CGROUP_CONGESTED,
326 LRUVEC_NODE_CONGESTED,
329 #endif /* !__GENERATING_BOUNDS_H */
332 * Evictable pages are divided into multiple generations. The youngest and the
333 * oldest generation numbers, max_seq and min_seq, are monotonically increasing.
334 * They form a sliding window of a variable size [MIN_NR_GENS, MAX_NR_GENS]. An
335 * offset within MAX_NR_GENS, i.e., gen, indexes the LRU list of the
336 * corresponding generation. The gen counter in folio->flags stores gen+1 while
337 * a page is on one of lrugen->folios[]. Otherwise it stores 0.
339 * A page is added to the youngest generation on faulting. The aging needs to
340 * check the accessed bit at least twice before handing this page over to the
341 * eviction. The first check takes care of the accessed bit set on the initial
342 * fault; the second check makes sure this page hasn't been used since then.
343 * This process, AKA second chance, requires a minimum of two generations,
344 * hence MIN_NR_GENS. And to maintain ABI compatibility with the active/inactive
345 * LRU, e.g., /proc/vmstat, these two generations are considered active; the
346 * rest of generations, if they exist, are considered inactive. See
347 * lru_gen_is_active().
349 * PG_active is always cleared while a page is on one of lrugen->folios[] so
350 * that the aging needs not to worry about it. And it's set again when a page
351 * considered active is isolated for non-reclaiming purposes, e.g., migration.
352 * See lru_gen_add_folio() and lru_gen_del_folio().
354 * MAX_NR_GENS is set to 4 so that the multi-gen LRU can support twice the
355 * number of categories of the active/inactive LRU when keeping track of
356 * accesses through page tables. This requires order_base_2(MAX_NR_GENS+1) bits
359 #define MIN_NR_GENS 2U
360 #define MAX_NR_GENS 4U
363 * Each generation is divided into multiple tiers. A page accessed N times
364 * through file descriptors is in tier order_base_2(N). A page in the first tier
365 * (N=0,1) is marked by PG_referenced unless it was faulted in through page
366 * tables or read ahead. A page in any other tier (N>1) is marked by
367 * PG_referenced and PG_workingset. This implies a minimum of two tiers is
368 * supported without using additional bits in folio->flags.
370 * In contrast to moving across generations which requires the LRU lock, moving
371 * across tiers only involves atomic operations on folio->flags and therefore
372 * has a negligible cost in the buffered access path. In the eviction path,
373 * comparisons of refaulted/(evicted+protected) from the first tier and the
374 * rest infer whether pages accessed multiple times through file descriptors
375 * are statistically hot and thus worth protecting.
377 * MAX_NR_TIERS is set to 4 so that the multi-gen LRU can support twice the
378 * number of categories of the active/inactive LRU when keeping track of
379 * accesses through file descriptors. This uses MAX_NR_TIERS-2 spare bits in
382 #define MAX_NR_TIERS 4U
384 #ifndef __GENERATING_BOUNDS_H
387 struct page_vma_mapped_walk;
389 #define LRU_GEN_MASK ((BIT(LRU_GEN_WIDTH) - 1) << LRU_GEN_PGOFF)
390 #define LRU_REFS_MASK ((BIT(LRU_REFS_WIDTH) - 1) << LRU_REFS_PGOFF)
392 #ifdef CONFIG_LRU_GEN
402 LRU_GEN_NONLEAF_YOUNG,
406 #define MIN_LRU_BATCH BITS_PER_LONG
407 #define MAX_LRU_BATCH (MIN_LRU_BATCH * 64)
409 /* whether to keep historical stats from evicted generations */
410 #ifdef CONFIG_LRU_GEN_STATS
411 #define NR_HIST_GENS MAX_NR_GENS
413 #define NR_HIST_GENS 1U
417 * The youngest generation number is stored in max_seq for both anon and file
418 * types as they are aged on an equal footing. The oldest generation numbers are
419 * stored in min_seq[] separately for anon and file types as clean file pages
420 * can be evicted regardless of swap constraints.
422 * Normally anon and file min_seq are in sync. But if swapping is constrained,
423 * e.g., out of swap space, file min_seq is allowed to advance and leave anon
426 * The number of pages in each generation is eventually consistent and therefore
427 * can be transiently negative when reset_batch_size() is pending.
429 struct lru_gen_folio {
430 /* the aging increments the youngest generation number */
431 unsigned long max_seq;
432 /* the eviction increments the oldest generation numbers */
433 unsigned long min_seq[ANON_AND_FILE];
434 /* the birth time of each generation in jiffies */
435 unsigned long timestamps[MAX_NR_GENS];
436 /* the multi-gen LRU lists, lazily sorted on eviction */
437 struct list_head folios[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES];
438 /* the multi-gen LRU sizes, eventually consistent */
439 long nr_pages[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES];
440 /* the exponential moving average of refaulted */
441 unsigned long avg_refaulted[ANON_AND_FILE][MAX_NR_TIERS];
442 /* the exponential moving average of evicted+protected */
443 unsigned long avg_total[ANON_AND_FILE][MAX_NR_TIERS];
444 /* the first tier doesn't need protection, hence the minus one */
445 unsigned long protected[NR_HIST_GENS][ANON_AND_FILE][MAX_NR_TIERS - 1];
446 /* can be modified without holding the LRU lock */
447 atomic_long_t evicted[NR_HIST_GENS][ANON_AND_FILE][MAX_NR_TIERS];
448 atomic_long_t refaulted[NR_HIST_GENS][ANON_AND_FILE][MAX_NR_TIERS];
449 /* whether the multi-gen LRU is enabled */
451 /* the memcg generation this lru_gen_folio belongs to */
453 /* the list segment this lru_gen_folio belongs to */
455 /* per-node lru_gen_folio list for global reclaim */
456 struct hlist_nulls_node list;
460 MM_LEAF_TOTAL, /* total leaf entries */
461 MM_LEAF_OLD, /* old leaf entries */
462 MM_LEAF_YOUNG, /* young leaf entries */
463 MM_NONLEAF_TOTAL, /* total non-leaf entries */
464 MM_NONLEAF_FOUND, /* non-leaf entries found in Bloom filters */
465 MM_NONLEAF_ADDED, /* non-leaf entries added to Bloom filters */
469 /* double-buffering Bloom filters */
470 #define NR_BLOOM_FILTERS 2
472 struct lru_gen_mm_state {
473 /* synced with max_seq after each iteration */
475 /* where the current iteration continues after */
476 struct list_head *head;
477 /* where the last iteration ended before */
478 struct list_head *tail;
479 /* Bloom filters flip after each iteration */
480 unsigned long *filters[NR_BLOOM_FILTERS];
481 /* the mm stats for debugging */
482 unsigned long stats[NR_HIST_GENS][NR_MM_STATS];
485 struct lru_gen_mm_walk {
486 /* the lruvec under reclaim */
487 struct lruvec *lruvec;
488 /* max_seq from lru_gen_folio: can be out of date */
490 /* the next address within an mm to scan */
491 unsigned long next_addr;
492 /* to batch promoted pages */
493 int nr_pages[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES];
494 /* to batch the mm stats */
495 int mm_stats[NR_MM_STATS];
496 /* total batched items */
503 * For each node, memcgs are divided into two generations: the old and the
504 * young. For each generation, memcgs are randomly sharded into multiple bins
505 * to improve scalability. For each bin, the hlist_nulls is virtually divided
506 * into three segments: the head, the tail and the default.
508 * An onlining memcg is added to the tail of a random bin in the old generation.
509 * The eviction starts at the head of a random bin in the old generation. The
510 * per-node memcg generation counter, whose reminder (mod MEMCG_NR_GENS) indexes
511 * the old generation, is incremented when all its bins become empty.
513 * There are four operations:
514 * 1. MEMCG_LRU_HEAD, which moves a memcg to the head of a random bin in its
515 * current generation (old or young) and updates its "seg" to "head";
516 * 2. MEMCG_LRU_TAIL, which moves a memcg to the tail of a random bin in its
517 * current generation (old or young) and updates its "seg" to "tail";
518 * 3. MEMCG_LRU_OLD, which moves a memcg to the head of a random bin in the old
519 * generation, updates its "gen" to "old" and resets its "seg" to "default";
520 * 4. MEMCG_LRU_YOUNG, which moves a memcg to the tail of a random bin in the
521 * young generation, updates its "gen" to "young" and resets its "seg" to
524 * The events that trigger the above operations are:
525 * 1. Exceeding the soft limit, which triggers MEMCG_LRU_HEAD;
526 * 2. The first attempt to reclaim a memcg below low, which triggers
528 * 3. The first attempt to reclaim a memcg offlined or below reclaimable size
529 * threshold, which triggers MEMCG_LRU_TAIL;
530 * 4. The second attempt to reclaim a memcg offlined or below reclaimable size
531 * threshold, which triggers MEMCG_LRU_YOUNG;
532 * 5. Attempting to reclaim a memcg below min, which triggers MEMCG_LRU_YOUNG;
533 * 6. Finishing the aging on the eviction path, which triggers MEMCG_LRU_YOUNG;
534 * 7. Offlining a memcg, which triggers MEMCG_LRU_OLD.
537 * 1. Memcg LRU only applies to global reclaim, and the round-robin incrementing
538 * of their max_seq counters ensures the eventual fairness to all eligible
539 * memcgs. For memcg reclaim, it still relies on mem_cgroup_iter().
540 * 2. There are only two valid generations: old (seq) and young (seq+1).
541 * MEMCG_NR_GENS is set to three so that when reading the generation counter
542 * locklessly, a stale value (seq-1) does not wraparound to young.
544 #define MEMCG_NR_GENS 3
545 #define MEMCG_NR_BINS 8
547 struct lru_gen_memcg {
548 /* the per-node memcg generation counter */
550 /* each memcg has one lru_gen_folio per node */
551 unsigned long nr_memcgs[MEMCG_NR_GENS];
552 /* per-node lru_gen_folio list for global reclaim */
553 struct hlist_nulls_head fifo[MEMCG_NR_GENS][MEMCG_NR_BINS];
554 /* protects the above */
558 void lru_gen_init_pgdat(struct pglist_data *pgdat);
559 void lru_gen_init_lruvec(struct lruvec *lruvec);
560 void lru_gen_look_around(struct page_vma_mapped_walk *pvmw);
562 void lru_gen_init_memcg(struct mem_cgroup *memcg);
563 void lru_gen_exit_memcg(struct mem_cgroup *memcg);
564 void lru_gen_online_memcg(struct mem_cgroup *memcg);
565 void lru_gen_offline_memcg(struct mem_cgroup *memcg);
566 void lru_gen_release_memcg(struct mem_cgroup *memcg);
567 void lru_gen_soft_reclaim(struct mem_cgroup *memcg, int nid);
569 #else /* !CONFIG_LRU_GEN */
571 static inline void lru_gen_init_pgdat(struct pglist_data *pgdat)
575 static inline void lru_gen_init_lruvec(struct lruvec *lruvec)
579 static inline void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
583 static inline void lru_gen_init_memcg(struct mem_cgroup *memcg)
587 static inline void lru_gen_exit_memcg(struct mem_cgroup *memcg)
591 static inline void lru_gen_online_memcg(struct mem_cgroup *memcg)
595 static inline void lru_gen_offline_memcg(struct mem_cgroup *memcg)
599 static inline void lru_gen_release_memcg(struct mem_cgroup *memcg)
603 static inline void lru_gen_soft_reclaim(struct mem_cgroup *memcg, int nid)
607 #endif /* CONFIG_LRU_GEN */
610 struct list_head lists[NR_LRU_LISTS];
611 /* per lruvec lru_lock for memcg */
614 * These track the cost of reclaiming one LRU - file or anon -
615 * over the other. As the observed cost of reclaiming one LRU
616 * increases, the reclaim scan balance tips toward the other.
618 unsigned long anon_cost;
619 unsigned long file_cost;
620 /* Non-resident age, driven by LRU movement */
621 atomic_long_t nonresident_age;
622 /* Refaults at the time of last reclaim cycle */
623 unsigned long refaults[ANON_AND_FILE];
624 /* Various lruvec state flags (enum lruvec_flags) */
626 #ifdef CONFIG_LRU_GEN
627 /* evictable pages divided into generations */
628 struct lru_gen_folio lrugen;
629 #ifdef CONFIG_LRU_GEN_WALKS_MMU
630 /* to concurrently iterate lru_gen_mm_list */
631 struct lru_gen_mm_state mm_state;
633 #endif /* CONFIG_LRU_GEN */
635 struct pglist_data *pgdat;
637 struct zswap_lruvec_state zswap_lruvec_state;
640 /* Isolate for asynchronous migration */
641 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4)
642 /* Isolate unevictable pages */
643 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8)
645 /* LRU Isolation modes. */
646 typedef unsigned __bitwise isolate_mode_t;
648 enum zone_watermarks {
657 * One per migratetype for each PAGE_ALLOC_COSTLY_ORDER. One additional list
658 * for THP which will usually be GFP_MOVABLE. Even if it is another type,
659 * it should not contribute to serious fragmentation causing THP allocation
662 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
667 #define NR_LOWORDER_PCP_LISTS (MIGRATE_PCPTYPES * (PAGE_ALLOC_COSTLY_ORDER + 1))
668 #define NR_PCP_LISTS (NR_LOWORDER_PCP_LISTS + NR_PCP_THP)
670 #define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost)
671 #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost)
672 #define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost)
673 #define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost)
676 * Flags used in pcp->flags field.
678 * PCPF_PREV_FREE_HIGH_ORDER: a high-order page is freed in the
679 * previous page freeing. To avoid to drain PCP for an accident
680 * high-order page freeing.
682 * PCPF_FREE_HIGH_BATCH: preserve "pcp->batch" pages in PCP before
683 * draining PCP for consecutive high-order pages freeing without
684 * allocation if data cache slice of CPU is large enough. To reduce
685 * zone lock contention and keep cache-hot pages reusing.
687 #define PCPF_PREV_FREE_HIGH_ORDER BIT(0)
688 #define PCPF_FREE_HIGH_BATCH BIT(1)
690 struct per_cpu_pages {
691 spinlock_t lock; /* Protects lists field */
692 int count; /* number of pages in the list */
693 int high; /* high watermark, emptying needed */
694 int high_min; /* min high watermark */
695 int high_max; /* max high watermark */
696 int batch; /* chunk size for buddy add/remove */
697 u8 flags; /* protected by pcp->lock */
698 u8 alloc_factor; /* batch scaling factor during allocate */
700 u8 expire; /* When 0, remote pagesets are drained */
702 short free_count; /* consecutive free count */
704 /* Lists of pages, one per migrate type stored on the pcp-lists */
705 struct list_head lists[NR_PCP_LISTS];
706 } ____cacheline_aligned_in_smp;
708 struct per_cpu_zonestat {
710 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
715 * Low priority inaccurate counters that are only folded
716 * on demand. Use a large type to avoid the overhead of
717 * folding during refresh_cpu_vm_stats.
719 unsigned long vm_numa_event[NR_VM_NUMA_EVENT_ITEMS];
723 struct per_cpu_nodestat {
725 s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS];
728 #endif /* !__GENERATING_BOUNDS.H */
732 * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able
733 * to DMA to all of the addressable memory (ZONE_NORMAL).
734 * On architectures where this area covers the whole 32 bit address
735 * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller
736 * DMA addressing constraints. This distinction is important as a 32bit
737 * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit
738 * platforms may need both zones as they support peripherals with
739 * different DMA addressing limitations.
741 #ifdef CONFIG_ZONE_DMA
744 #ifdef CONFIG_ZONE_DMA32
748 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
749 * performed on pages in ZONE_NORMAL if the DMA devices support
750 * transfers to all addressable memory.
753 #ifdef CONFIG_HIGHMEM
755 * A memory area that is only addressable by the kernel through
756 * mapping portions into its own address space. This is for example
757 * used by i386 to allow the kernel to address the memory beyond
758 * 900MB. The kernel will set up special mappings (page
759 * table entries on i386) for each page that the kernel needs to
765 * ZONE_MOVABLE is similar to ZONE_NORMAL, except that it contains
766 * movable pages with few exceptional cases described below. Main use
767 * cases for ZONE_MOVABLE are to make memory offlining/unplug more
768 * likely to succeed, and to locally limit unmovable allocations - e.g.,
769 * to increase the number of THP/huge pages. Notable special cases are:
771 * 1. Pinned pages: (long-term) pinning of movable pages might
772 * essentially turn such pages unmovable. Therefore, we do not allow
773 * pinning long-term pages in ZONE_MOVABLE. When pages are pinned and
774 * faulted, they come from the right zone right away. However, it is
775 * still possible that address space already has pages in
776 * ZONE_MOVABLE at the time when pages are pinned (i.e. user has
777 * touches that memory before pinning). In such case we migrate them
778 * to a different zone. When migration fails - pinning fails.
779 * 2. memblock allocations: kernelcore/movablecore setups might create
780 * situations where ZONE_MOVABLE contains unmovable allocations
781 * after boot. Memory offlining and allocations fail early.
782 * 3. Memory holes: kernelcore/movablecore setups might create very rare
783 * situations where ZONE_MOVABLE contains memory holes after boot,
784 * for example, if we have sections that are only partially
785 * populated. Memory offlining and allocations fail early.
786 * 4. PG_hwpoison pages: while poisoned pages can be skipped during
787 * memory offlining, such pages cannot be allocated.
788 * 5. Unmovable PG_offline pages: in paravirtualized environments,
789 * hotplugged memory blocks might only partially be managed by the
790 * buddy (e.g., via XEN-balloon, Hyper-V balloon, virtio-mem). The
791 * parts not manged by the buddy are unmovable PG_offline pages. In
792 * some cases (virtio-mem), such pages can be skipped during
793 * memory offlining, however, cannot be moved/allocated. These
794 * techniques might use alloc_contig_range() to hide previously
795 * exposed pages from the buddy again (e.g., to implement some sort
796 * of memory unplug in virtio-mem).
797 * 6. ZERO_PAGE(0), kernelcore/movablecore setups might create
798 * situations where ZERO_PAGE(0) which is allocated differently
799 * on different platforms may end up in a movable zone. ZERO_PAGE(0)
800 * cannot be migrated.
801 * 7. Memory-hotplug: when using memmap_on_memory and onlining the
802 * memory to the MOVABLE zone, the vmemmap pages are also placed in
803 * such zone. Such pages cannot be really moved around as they are
804 * self-stored in the range, but they are treated as movable when
805 * the range they describe is about to be offlined.
807 * In general, no unmovable allocations that degrade memory offlining
808 * should end up in ZONE_MOVABLE. Allocators (like alloc_contig_range())
809 * have to expect that migrating pages in ZONE_MOVABLE can fail (even
810 * if has_unmovable_pages() states that there are no unmovable pages,
811 * there can be false negatives).
814 #ifdef CONFIG_ZONE_DEVICE
821 #ifndef __GENERATING_BOUNDS_H
823 #define ASYNC_AND_SYNC 2
826 /* Read-mostly fields */
828 /* zone watermarks, access with *_wmark_pages(zone) macros */
829 unsigned long _watermark[NR_WMARK];
830 unsigned long watermark_boost;
832 unsigned long nr_reserved_highatomic;
835 * We don't know if the memory that we're going to allocate will be
836 * freeable or/and it will be released eventually, so to avoid totally
837 * wasting several GB of ram we must reserve some of the lower zone
838 * memory (otherwise we risk to run OOM on the lower zones despite
839 * there being tons of freeable ram on the higher zones). This array is
840 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl
843 long lowmem_reserve[MAX_NR_ZONES];
848 struct pglist_data *zone_pgdat;
849 struct per_cpu_pages __percpu *per_cpu_pageset;
850 struct per_cpu_zonestat __percpu *per_cpu_zonestats;
852 * the high and batch values are copied to individual pagesets for
855 int pageset_high_min;
856 int pageset_high_max;
859 #ifndef CONFIG_SPARSEMEM
861 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
862 * In SPARSEMEM, this map is stored in struct mem_section
864 unsigned long *pageblock_flags;
865 #endif /* CONFIG_SPARSEMEM */
867 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
868 unsigned long zone_start_pfn;
871 * spanned_pages is the total pages spanned by the zone, including
872 * holes, which is calculated as:
873 * spanned_pages = zone_end_pfn - zone_start_pfn;
875 * present_pages is physical pages existing within the zone, which
877 * present_pages = spanned_pages - absent_pages(pages in holes);
879 * present_early_pages is present pages existing within the zone
880 * located on memory available since early boot, excluding hotplugged
883 * managed_pages is present pages managed by the buddy system, which
884 * is calculated as (reserved_pages includes pages allocated by the
885 * bootmem allocator):
886 * managed_pages = present_pages - reserved_pages;
888 * cma pages is present pages that are assigned for CMA use
891 * So present_pages may be used by memory hotplug or memory power
892 * management logic to figure out unmanaged pages by checking
893 * (present_pages - managed_pages). And managed_pages should be used
894 * by page allocator and vm scanner to calculate all kinds of watermarks
899 * zone_start_pfn and spanned_pages are protected by span_seqlock.
900 * It is a seqlock because it has to be read outside of zone->lock,
901 * and it is done in the main allocator path. But, it is written
902 * quite infrequently.
904 * The span_seq lock is declared along with zone->lock because it is
905 * frequently read in proximity to zone->lock. It's good to
906 * give them a chance of being in the same cacheline.
908 * Write access to present_pages at runtime should be protected by
909 * mem_hotplug_begin/done(). Any reader who can't tolerant drift of
910 * present_pages should use get_online_mems() to get a stable value.
912 atomic_long_t managed_pages;
913 unsigned long spanned_pages;
914 unsigned long present_pages;
915 #if defined(CONFIG_MEMORY_HOTPLUG)
916 unsigned long present_early_pages;
919 unsigned long cma_pages;
924 #ifdef CONFIG_MEMORY_ISOLATION
926 * Number of isolated pageblock. It is used to solve incorrect
927 * freepage counting problem due to racy retrieving migratetype
928 * of pageblock. Protected by zone->lock.
930 unsigned long nr_isolate_pageblock;
933 #ifdef CONFIG_MEMORY_HOTPLUG
934 /* see spanned/present_pages for more description */
935 seqlock_t span_seqlock;
940 /* Write-intensive fields used from the page allocator */
941 CACHELINE_PADDING(_pad1_);
943 /* free areas of different sizes */
944 struct free_area free_area[NR_PAGE_ORDERS];
946 #ifdef CONFIG_UNACCEPTED_MEMORY
947 /* Pages to be accepted. All pages on the list are MAX_PAGE_ORDER */
948 struct list_head unaccepted_pages;
951 /* zone flags, see below */
954 /* Primarily protects free_area */
957 /* Write-intensive fields used by compaction and vmstats. */
958 CACHELINE_PADDING(_pad2_);
961 * When free pages are below this point, additional steps are taken
962 * when reading the number of free pages to avoid per-cpu counter
963 * drift allowing watermarks to be breached
965 unsigned long percpu_drift_mark;
967 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
968 /* pfn where compaction free scanner should start */
969 unsigned long compact_cached_free_pfn;
970 /* pfn where compaction migration scanner should start */
971 unsigned long compact_cached_migrate_pfn[ASYNC_AND_SYNC];
972 unsigned long compact_init_migrate_pfn;
973 unsigned long compact_init_free_pfn;
976 #ifdef CONFIG_COMPACTION
978 * On compaction failure, 1<<compact_defer_shift compactions
979 * are skipped before trying again. The number attempted since
980 * last failure is tracked with compact_considered.
981 * compact_order_failed is the minimum compaction failed order.
983 unsigned int compact_considered;
984 unsigned int compact_defer_shift;
985 int compact_order_failed;
988 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
989 /* Set to true when the PG_migrate_skip bits should be cleared */
990 bool compact_blockskip_flush;
995 CACHELINE_PADDING(_pad3_);
996 /* Zone statistics */
997 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
998 atomic_long_t vm_numa_event[NR_VM_NUMA_EVENT_ITEMS];
999 } ____cacheline_internodealigned_in_smp;
1002 PGDAT_DIRTY, /* reclaim scanning has recently found
1003 * many dirty file pages at the tail
1006 PGDAT_WRITEBACK, /* reclaim scanning has recently found
1007 * many pages under writeback
1009 PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */
1013 ZONE_BOOSTED_WATERMARK, /* zone recently boosted watermarks.
1014 * Cleared when kswapd is woken.
1016 ZONE_RECLAIM_ACTIVE, /* kswapd may be scanning the zone. */
1017 ZONE_BELOW_HIGH, /* zone is below high watermark. */
1020 static inline unsigned long zone_managed_pages(struct zone *zone)
1022 return (unsigned long)atomic_long_read(&zone->managed_pages);
1025 static inline unsigned long zone_cma_pages(struct zone *zone)
1028 return zone->cma_pages;
1034 static inline unsigned long zone_end_pfn(const struct zone *zone)
1036 return zone->zone_start_pfn + zone->spanned_pages;
1039 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)
1041 return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone);
1044 static inline bool zone_is_initialized(struct zone *zone)
1046 return zone->initialized;
1049 static inline bool zone_is_empty(struct zone *zone)
1051 return zone->spanned_pages == 0;
1054 #ifndef BUILD_VDSO32_64
1056 * The zone field is never updated after free_area_init_core()
1057 * sets it, so none of the operations on it need to be atomic.
1060 /* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_CPUPID] | ... | FLAGS | */
1061 #define SECTIONS_PGOFF ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
1062 #define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH)
1063 #define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH)
1064 #define LAST_CPUPID_PGOFF (ZONES_PGOFF - LAST_CPUPID_WIDTH)
1065 #define KASAN_TAG_PGOFF (LAST_CPUPID_PGOFF - KASAN_TAG_WIDTH)
1066 #define LRU_GEN_PGOFF (KASAN_TAG_PGOFF - LRU_GEN_WIDTH)
1067 #define LRU_REFS_PGOFF (LRU_GEN_PGOFF - LRU_REFS_WIDTH)
1070 * Define the bit shifts to access each section. For non-existent
1071 * sections we define the shift as 0; that plus a 0 mask ensures
1072 * the compiler will optimise away reference to them.
1074 #define SECTIONS_PGSHIFT (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
1075 #define NODES_PGSHIFT (NODES_PGOFF * (NODES_WIDTH != 0))
1076 #define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_WIDTH != 0))
1077 #define LAST_CPUPID_PGSHIFT (LAST_CPUPID_PGOFF * (LAST_CPUPID_WIDTH != 0))
1078 #define KASAN_TAG_PGSHIFT (KASAN_TAG_PGOFF * (KASAN_TAG_WIDTH != 0))
1080 /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */
1081 #ifdef NODE_NOT_IN_PAGE_FLAGS
1082 #define ZONEID_SHIFT (SECTIONS_SHIFT + ZONES_SHIFT)
1083 #define ZONEID_PGOFF ((SECTIONS_PGOFF < ZONES_PGOFF) ? \
1084 SECTIONS_PGOFF : ZONES_PGOFF)
1086 #define ZONEID_SHIFT (NODES_SHIFT + ZONES_SHIFT)
1087 #define ZONEID_PGOFF ((NODES_PGOFF < ZONES_PGOFF) ? \
1088 NODES_PGOFF : ZONES_PGOFF)
1091 #define ZONEID_PGSHIFT (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
1093 #define ZONES_MASK ((1UL << ZONES_WIDTH) - 1)
1094 #define NODES_MASK ((1UL << NODES_WIDTH) - 1)
1095 #define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1)
1096 #define LAST_CPUPID_MASK ((1UL << LAST_CPUPID_SHIFT) - 1)
1097 #define KASAN_TAG_MASK ((1UL << KASAN_TAG_WIDTH) - 1)
1098 #define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1)
1100 static inline enum zone_type page_zonenum(const struct page *page)
1102 ASSERT_EXCLUSIVE_BITS(page->flags, ZONES_MASK << ZONES_PGSHIFT);
1103 return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
1106 static inline enum zone_type folio_zonenum(const struct folio *folio)
1108 return page_zonenum(&folio->page);
1111 #ifdef CONFIG_ZONE_DEVICE
1112 static inline bool is_zone_device_page(const struct page *page)
1114 return page_zonenum(page) == ZONE_DEVICE;
1118 * Consecutive zone device pages should not be merged into the same sgl
1119 * or bvec segment with other types of pages or if they belong to different
1120 * pgmaps. Otherwise getting the pgmap of a given segment is not possible
1121 * without scanning the entire segment. This helper returns true either if
1122 * both pages are not zone device pages or both pages are zone device pages
1123 * with the same pgmap.
1125 static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
1126 const struct page *b)
1128 if (is_zone_device_page(a) != is_zone_device_page(b))
1130 if (!is_zone_device_page(a))
1132 return a->pgmap == b->pgmap;
1135 extern void memmap_init_zone_device(struct zone *, unsigned long,
1136 unsigned long, struct dev_pagemap *);
1138 static inline bool is_zone_device_page(const struct page *page)
1142 static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
1143 const struct page *b)
1149 static inline bool folio_is_zone_device(const struct folio *folio)
1151 return is_zone_device_page(&folio->page);
1154 static inline bool is_zone_movable_page(const struct page *page)
1156 return page_zonenum(page) == ZONE_MOVABLE;
1159 static inline bool folio_is_zone_movable(const struct folio *folio)
1161 return folio_zonenum(folio) == ZONE_MOVABLE;
1166 * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty
1167 * intersection with the given zone
1169 static inline bool zone_intersects(struct zone *zone,
1170 unsigned long start_pfn, unsigned long nr_pages)
1172 if (zone_is_empty(zone))
1174 if (start_pfn >= zone_end_pfn(zone) ||
1175 start_pfn + nr_pages <= zone->zone_start_pfn)
1182 * The "priority" of VM scanning is how much of the queues we will scan in one
1183 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
1184 * queues ("queue_length >> 12") during an aging round.
1186 #define DEF_PRIORITY 12
1188 /* Maximum number of zones on a zonelist */
1189 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
1192 ZONELIST_FALLBACK, /* zonelist with fallback */
1195 * The NUMA zonelists are doubled because we need zonelists that
1196 * restrict the allocations to a single node for __GFP_THISNODE.
1198 ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */
1204 * This struct contains information about a zone in a zonelist. It is stored
1205 * here to avoid dereferences into large structures and lookups of tables
1208 struct zone *zone; /* Pointer to actual zone */
1209 int zone_idx; /* zone_idx(zoneref->zone) */
1213 * One allocation request operates on a zonelist. A zonelist
1214 * is a list of zones, the first one is the 'goal' of the
1215 * allocation, the other zones are fallback zones, in decreasing
1218 * To speed the reading of the zonelist, the zonerefs contain the zone index
1219 * of the entry being read. Helper functions to access information given
1220 * a struct zoneref are
1222 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
1223 * zonelist_zone_idx() - Return the index of the zone for an entry
1224 * zonelist_node_idx() - Return the index of the node for an entry
1227 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
1231 * The array of struct pages for flatmem.
1232 * It must be declared for SPARSEMEM as well because there are configurations
1233 * that rely on that.
1235 extern struct page *mem_map;
1237 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1238 struct deferred_split {
1239 spinlock_t split_queue_lock;
1240 struct list_head split_queue;
1241 unsigned long split_queue_len;
1245 #ifdef CONFIG_MEMORY_FAILURE
1247 * Per NUMA node memory failure handling statistics.
1249 struct memory_failure_stats {
1251 * Number of raw pages poisoned.
1252 * Cases not accounted: memory outside kernel control, offline page,
1253 * arch-specific memory_failure (SGX), hwpoison_filter() filtered
1254 * error events, and unpoison actions from hwpoison_unpoison.
1256 unsigned long total;
1258 * Recovery results of poisoned raw pages handled by memory_failure,
1259 * in sync with mf_result.
1260 * total = ignored + failed + delayed + recovered.
1261 * total * PAGE_SIZE * #nodes = /proc/meminfo/HardwareCorrupted.
1263 unsigned long ignored;
1264 unsigned long failed;
1265 unsigned long delayed;
1266 unsigned long recovered;
1271 * On NUMA machines, each NUMA node would have a pg_data_t to describe
1272 * it's memory layout. On UMA machines there is a single pglist_data which
1273 * describes the whole memory.
1275 * Memory statistics and page replacement data structures are maintained on a
1278 typedef struct pglist_data {
1280 * node_zones contains just the zones for THIS node. Not all of the
1281 * zones may be populated, but it is the full list. It is referenced by
1282 * this node's node_zonelists as well as other node's node_zonelists.
1284 struct zone node_zones[MAX_NR_ZONES];
1287 * node_zonelists contains references to all zones in all nodes.
1288 * Generally the first zones will be references to this node's
1291 struct zonelist node_zonelists[MAX_ZONELISTS];
1293 int nr_zones; /* number of populated zones in this node */
1294 #ifdef CONFIG_FLATMEM /* means !SPARSEMEM */
1295 struct page *node_mem_map;
1296 #ifdef CONFIG_PAGE_EXTENSION
1297 struct page_ext *node_page_ext;
1300 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
1302 * Must be held any time you expect node_start_pfn,
1303 * node_present_pages, node_spanned_pages or nr_zones to stay constant.
1304 * Also synchronizes pgdat->first_deferred_pfn during deferred page
1307 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to
1308 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG
1309 * or CONFIG_DEFERRED_STRUCT_PAGE_INIT.
1311 * Nests above zone->lock and zone->span_seqlock
1313 spinlock_t node_size_lock;
1315 unsigned long node_start_pfn;
1316 unsigned long node_present_pages; /* total number of physical pages */
1317 unsigned long node_spanned_pages; /* total size of physical page
1318 range, including holes */
1320 wait_queue_head_t kswapd_wait;
1321 wait_queue_head_t pfmemalloc_wait;
1323 /* workqueues for throttling reclaim for different reasons. */
1324 wait_queue_head_t reclaim_wait[NR_VMSCAN_THROTTLE];
1326 atomic_t nr_writeback_throttled;/* nr of writeback-throttled tasks */
1327 unsigned long nr_reclaim_start; /* nr pages written while throttled
1328 * when throttling started. */
1329 #ifdef CONFIG_MEMORY_HOTPLUG
1330 struct mutex kswapd_lock;
1332 struct task_struct *kswapd; /* Protected by kswapd_lock */
1334 enum zone_type kswapd_highest_zoneidx;
1336 int kswapd_failures; /* Number of 'reclaimed == 0' runs */
1338 #ifdef CONFIG_COMPACTION
1339 int kcompactd_max_order;
1340 enum zone_type kcompactd_highest_zoneidx;
1341 wait_queue_head_t kcompactd_wait;
1342 struct task_struct *kcompactd;
1343 bool proactive_compact_trigger;
1346 * This is a per-node reserve of pages that are not available
1347 * to userspace allocations.
1349 unsigned long totalreserve_pages;
1353 * node reclaim becomes active if more unmapped pages exist.
1355 unsigned long min_unmapped_pages;
1356 unsigned long min_slab_pages;
1357 #endif /* CONFIG_NUMA */
1359 /* Write-intensive fields used by page reclaim */
1360 CACHELINE_PADDING(_pad1_);
1362 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1364 * If memory initialisation on large machines is deferred then this
1365 * is the first PFN that needs to be initialised.
1367 unsigned long first_deferred_pfn;
1368 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1370 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1371 struct deferred_split deferred_split_queue;
1374 #ifdef CONFIG_NUMA_BALANCING
1375 /* start time in ms of current promote rate limit period */
1376 unsigned int nbp_rl_start;
1377 /* number of promote candidate pages at start time of current rate limit period */
1378 unsigned long nbp_rl_nr_cand;
1379 /* promote threshold in ms */
1380 unsigned int nbp_threshold;
1381 /* start time in ms of current promote threshold adjustment period */
1382 unsigned int nbp_th_start;
1384 * number of promote candidate pages at start time of current promote
1385 * threshold adjustment period
1387 unsigned long nbp_th_nr_cand;
1389 /* Fields commonly accessed by the page reclaim scanner */
1392 * NOTE: THIS IS UNUSED IF MEMCG IS ENABLED.
1394 * Use mem_cgroup_lruvec() to look up lruvecs.
1396 struct lruvec __lruvec;
1398 unsigned long flags;
1400 #ifdef CONFIG_LRU_GEN
1401 /* kswap mm walk data */
1402 struct lru_gen_mm_walk mm_walk;
1403 /* lru_gen_folio list */
1404 struct lru_gen_memcg memcg_lru;
1407 CACHELINE_PADDING(_pad2_);
1409 /* Per-node vmstats */
1410 struct per_cpu_nodestat __percpu *per_cpu_nodestats;
1411 atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS];
1413 struct memory_tier __rcu *memtier;
1415 #ifdef CONFIG_MEMORY_FAILURE
1416 struct memory_failure_stats mf_stats;
1420 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
1421 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
1423 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn)
1424 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))
1426 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat)
1428 return pgdat->node_start_pfn + pgdat->node_spanned_pages;
1431 #include <linux/memory_hotplug.h>
1433 void build_all_zonelists(pg_data_t *pgdat);
1434 void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order,
1435 enum zone_type highest_zoneidx);
1436 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
1437 int highest_zoneidx, unsigned int alloc_flags,
1439 bool zone_watermark_ok(struct zone *z, unsigned int order,
1440 unsigned long mark, int highest_zoneidx,
1441 unsigned int alloc_flags);
1442 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
1443 unsigned long mark, int highest_zoneidx);
1445 * Memory initialization context, use to differentiate memory added by
1446 * the platform statically or via memory hotplug interface.
1448 enum meminit_context {
1453 extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
1454 unsigned long size);
1456 extern void lruvec_init(struct lruvec *lruvec);
1458 static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec)
1461 return lruvec->pgdat;
1463 return container_of(lruvec, struct pglist_data, __lruvec);
1467 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
1468 int local_memory_node(int node_id);
1470 static inline int local_memory_node(int node_id) { return node_id; };
1474 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
1476 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
1478 #ifdef CONFIG_ZONE_DEVICE
1479 static inline bool zone_is_zone_device(struct zone *zone)
1481 return zone_idx(zone) == ZONE_DEVICE;
1484 static inline bool zone_is_zone_device(struct zone *zone)
1491 * Returns true if a zone has pages managed by the buddy allocator.
1492 * All the reclaim decisions have to use this function rather than
1493 * populated_zone(). If the whole zone is reserved then we can easily
1494 * end up with populated_zone() && !managed_zone().
1496 static inline bool managed_zone(struct zone *zone)
1498 return zone_managed_pages(zone);
1501 /* Returns true if a zone has memory */
1502 static inline bool populated_zone(struct zone *zone)
1504 return zone->present_pages;
1508 static inline int zone_to_nid(struct zone *zone)
1513 static inline void zone_set_nid(struct zone *zone, int nid)
1518 static inline int zone_to_nid(struct zone *zone)
1523 static inline void zone_set_nid(struct zone *zone, int nid) {}
1526 extern int movable_zone;
1528 static inline int is_highmem_idx(enum zone_type idx)
1530 #ifdef CONFIG_HIGHMEM
1531 return (idx == ZONE_HIGHMEM ||
1532 (idx == ZONE_MOVABLE && movable_zone == ZONE_HIGHMEM));
1539 * is_highmem - helper function to quickly check if a struct zone is a
1540 * highmem zone or not. This is an attempt to keep references
1541 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
1542 * @zone: pointer to struct zone variable
1543 * Return: 1 for a highmem zone, 0 otherwise
1545 static inline int is_highmem(struct zone *zone)
1547 return is_highmem_idx(zone_idx(zone));
1550 #ifdef CONFIG_ZONE_DMA
1551 bool has_managed_dma(void);
1553 static inline bool has_managed_dma(void)
1562 extern struct pglist_data contig_page_data;
1563 static inline struct pglist_data *NODE_DATA(int nid)
1565 return &contig_page_data;
1568 #else /* CONFIG_NUMA */
1570 #include <asm/mmzone.h>
1572 #endif /* !CONFIG_NUMA */
1574 extern struct pglist_data *first_online_pgdat(void);
1575 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
1576 extern struct zone *next_zone(struct zone *zone);
1579 * for_each_online_pgdat - helper macro to iterate over all online nodes
1580 * @pgdat: pointer to a pg_data_t variable
1582 #define for_each_online_pgdat(pgdat) \
1583 for (pgdat = first_online_pgdat(); \
1585 pgdat = next_online_pgdat(pgdat))
1587 * for_each_zone - helper macro to iterate over all memory zones
1588 * @zone: pointer to struct zone variable
1590 * The user only needs to declare the zone variable, for_each_zone
1593 #define for_each_zone(zone) \
1594 for (zone = (first_online_pgdat())->node_zones; \
1596 zone = next_zone(zone))
1598 #define for_each_populated_zone(zone) \
1599 for (zone = (first_online_pgdat())->node_zones; \
1601 zone = next_zone(zone)) \
1602 if (!populated_zone(zone)) \
1603 ; /* do nothing */ \
1606 static inline struct zone *zonelist_zone(struct zoneref *zoneref)
1608 return zoneref->zone;
1611 static inline int zonelist_zone_idx(struct zoneref *zoneref)
1613 return zoneref->zone_idx;
1616 static inline int zonelist_node_idx(struct zoneref *zoneref)
1618 return zone_to_nid(zoneref->zone);
1621 struct zoneref *__next_zones_zonelist(struct zoneref *z,
1622 enum zone_type highest_zoneidx,
1626 * 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
1627 * @z: The cursor used as a starting point for the search
1628 * @highest_zoneidx: The zone index of the highest zone to return
1629 * @nodes: An optional nodemask to filter the zonelist with
1631 * This function returns the next zone at or below a given zone index that is
1632 * within the allowed nodemask using a cursor as the starting point for the
1633 * search. The zoneref returned is a cursor that represents the current zone
1634 * being examined. It should be advanced by one before calling
1635 * next_zones_zonelist again.
1637 * Return: the next zone at or below highest_zoneidx within the allowed
1638 * nodemask using a cursor within a zonelist as a starting point
1640 static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z,
1641 enum zone_type highest_zoneidx,
1644 if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx))
1646 return __next_zones_zonelist(z, highest_zoneidx, nodes);
1650 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
1651 * @zonelist: The zonelist to search for a suitable zone
1652 * @highest_zoneidx: The zone index of the highest zone to return
1653 * @nodes: An optional nodemask to filter the zonelist with
1655 * This function returns the first zone at or below a given zone index that is
1656 * within the allowed nodemask. The zoneref returned is a cursor that can be
1657 * used to iterate the zonelist with next_zones_zonelist by advancing it by
1658 * one before calling.
1660 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is
1661 * never NULL). This may happen either genuinely, or due to concurrent nodemask
1662 * update due to cpuset modification.
1664 * Return: Zoneref pointer for the first suitable zone found
1666 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
1667 enum zone_type highest_zoneidx,
1670 return next_zones_zonelist(zonelist->_zonerefs,
1671 highest_zoneidx, nodes);
1675 * 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
1676 * @zone: The current zone in the iterator
1677 * @z: The current pointer within zonelist->_zonerefs being iterated
1678 * @zlist: The zonelist being iterated
1679 * @highidx: The zone index of the highest zone to return
1680 * @nodemask: Nodemask allowed by the allocator
1682 * This iterator iterates though all zones at or below a given zone index and
1683 * within a given nodemask
1685 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
1686 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \
1688 z = next_zones_zonelist(++z, highidx, nodemask), \
1689 zone = zonelist_zone(z))
1691 #define for_next_zone_zonelist_nodemask(zone, z, highidx, nodemask) \
1692 for (zone = z->zone; \
1694 z = next_zones_zonelist(++z, highidx, nodemask), \
1695 zone = zonelist_zone(z))
1699 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
1700 * @zone: The current zone in the iterator
1701 * @z: The current pointer within zonelist->zones being iterated
1702 * @zlist: The zonelist being iterated
1703 * @highidx: The zone index of the highest zone to return
1705 * This iterator iterates though all zones at or below a given zone index.
1707 #define for_each_zone_zonelist(zone, z, zlist, highidx) \
1708 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
1710 /* Whether the 'nodes' are all movable nodes */
1711 static inline bool movable_only_nodes(nodemask_t *nodes)
1713 struct zonelist *zonelist;
1717 if (nodes_empty(*nodes))
1721 * We can chose arbitrary node from the nodemask to get a
1722 * zonelist as they are interlinked. We just need to find
1723 * at least one zone that can satisfy kernel allocations.
1725 nid = first_node(*nodes);
1726 zonelist = &NODE_DATA(nid)->node_zonelists[ZONELIST_FALLBACK];
1727 z = first_zones_zonelist(zonelist, ZONE_NORMAL, nodes);
1728 return (!z->zone) ? true : false;
1732 #ifdef CONFIG_SPARSEMEM
1733 #include <asm/sparsemem.h>
1736 #ifdef CONFIG_FLATMEM
1737 #define pfn_to_nid(pfn) (0)
1740 #ifdef CONFIG_SPARSEMEM
1743 * PA_SECTION_SHIFT physical address to/from section number
1744 * PFN_SECTION_SHIFT pfn to/from section number
1746 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
1747 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
1749 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
1751 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
1752 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
1754 #define SECTION_BLOCKFLAGS_BITS \
1755 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
1757 #if (MAX_PAGE_ORDER + PAGE_SHIFT) > SECTION_SIZE_BITS
1758 #error Allocator MAX_PAGE_ORDER exceeds SECTION_SIZE
1761 static inline unsigned long pfn_to_section_nr(unsigned long pfn)
1763 return pfn >> PFN_SECTION_SHIFT;
1765 static inline unsigned long section_nr_to_pfn(unsigned long sec)
1767 return sec << PFN_SECTION_SHIFT;
1770 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)
1771 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK)
1773 #define SUBSECTION_SHIFT 21
1774 #define SUBSECTION_SIZE (1UL << SUBSECTION_SHIFT)
1776 #define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT)
1777 #define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT)
1778 #define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1))
1780 #if SUBSECTION_SHIFT > SECTION_SIZE_BITS
1781 #error Subsection size exceeds section size
1783 #define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT))
1786 #define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION)
1787 #define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK)
1789 struct mem_section_usage {
1790 struct rcu_head rcu;
1791 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1792 DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION);
1794 /* See declaration of similar field in struct zone */
1795 unsigned long pageblock_flags[0];
1798 void subsection_map_init(unsigned long pfn, unsigned long nr_pages);
1802 struct mem_section {
1804 * This is, logically, a pointer to an array of struct
1805 * pages. However, it is stored with some other magic.
1806 * (see sparse.c::sparse_init_one_section())
1808 * Additionally during early boot we encode node id of
1809 * the location of the section here to guide allocation.
1810 * (see sparse.c::memory_present())
1812 * Making it a UL at least makes someone do a cast
1813 * before using it wrong.
1815 unsigned long section_mem_map;
1817 struct mem_section_usage *usage;
1818 #ifdef CONFIG_PAGE_EXTENSION
1820 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use
1821 * section. (see page_ext.h about this.)
1823 struct page_ext *page_ext;
1827 * WARNING: mem_section must be a power-of-2 in size for the
1828 * calculation and use of SECTION_ROOT_MASK to make sense.
1832 #ifdef CONFIG_SPARSEMEM_EXTREME
1833 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
1835 #define SECTIONS_PER_ROOT 1
1838 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
1839 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT)
1840 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
1842 #ifdef CONFIG_SPARSEMEM_EXTREME
1843 extern struct mem_section **mem_section;
1845 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
1848 static inline unsigned long *section_to_usemap(struct mem_section *ms)
1850 return ms->usage->pageblock_flags;
1853 static inline struct mem_section *__nr_to_section(unsigned long nr)
1855 unsigned long root = SECTION_NR_TO_ROOT(nr);
1857 if (unlikely(root >= NR_SECTION_ROOTS))
1860 #ifdef CONFIG_SPARSEMEM_EXTREME
1861 if (!mem_section || !mem_section[root])
1864 return &mem_section[root][nr & SECTION_ROOT_MASK];
1866 extern size_t mem_section_usage_size(void);
1869 * We use the lower bits of the mem_map pointer to store
1870 * a little bit of information. The pointer is calculated
1871 * as mem_map - section_nr_to_pfn(pnum). The result is
1872 * aligned to the minimum alignment of the two values:
1873 * 1. All mem_map arrays are page-aligned.
1874 * 2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT
1875 * lowest bits. PFN_SECTION_SHIFT is arch-specific
1876 * (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the
1877 * worst combination is powerpc with 256k pages,
1878 * which results in PFN_SECTION_SHIFT equal 6.
1879 * To sum it up, at least 6 bits are available on all architectures.
1880 * However, we can exceed 6 bits on some other architectures except
1881 * powerpc (e.g. 15 bits are available on x86_64, 13 bits are available
1882 * with the worst case of 64K pages on arm64) if we make sure the
1883 * exceeded bit is not applicable to powerpc.
1886 SECTION_MARKED_PRESENT_BIT,
1887 SECTION_HAS_MEM_MAP_BIT,
1888 SECTION_IS_ONLINE_BIT,
1889 SECTION_IS_EARLY_BIT,
1890 #ifdef CONFIG_ZONE_DEVICE
1891 SECTION_TAINT_ZONE_DEVICE_BIT,
1893 SECTION_MAP_LAST_BIT,
1896 #define SECTION_MARKED_PRESENT BIT(SECTION_MARKED_PRESENT_BIT)
1897 #define SECTION_HAS_MEM_MAP BIT(SECTION_HAS_MEM_MAP_BIT)
1898 #define SECTION_IS_ONLINE BIT(SECTION_IS_ONLINE_BIT)
1899 #define SECTION_IS_EARLY BIT(SECTION_IS_EARLY_BIT)
1900 #ifdef CONFIG_ZONE_DEVICE
1901 #define SECTION_TAINT_ZONE_DEVICE BIT(SECTION_TAINT_ZONE_DEVICE_BIT)
1903 #define SECTION_MAP_MASK (~(BIT(SECTION_MAP_LAST_BIT) - 1))
1904 #define SECTION_NID_SHIFT SECTION_MAP_LAST_BIT
1906 static inline struct page *__section_mem_map_addr(struct mem_section *section)
1908 unsigned long map = section->section_mem_map;
1909 map &= SECTION_MAP_MASK;
1910 return (struct page *)map;
1913 static inline int present_section(struct mem_section *section)
1915 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
1918 static inline int present_section_nr(unsigned long nr)
1920 return present_section(__nr_to_section(nr));
1923 static inline int valid_section(struct mem_section *section)
1925 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
1928 static inline int early_section(struct mem_section *section)
1930 return (section && (section->section_mem_map & SECTION_IS_EARLY));
1933 static inline int valid_section_nr(unsigned long nr)
1935 return valid_section(__nr_to_section(nr));
1938 static inline int online_section(struct mem_section *section)
1940 return (section && (section->section_mem_map & SECTION_IS_ONLINE));
1943 #ifdef CONFIG_ZONE_DEVICE
1944 static inline int online_device_section(struct mem_section *section)
1946 unsigned long flags = SECTION_IS_ONLINE | SECTION_TAINT_ZONE_DEVICE;
1948 return section && ((section->section_mem_map & flags) == flags);
1951 static inline int online_device_section(struct mem_section *section)
1957 static inline int online_section_nr(unsigned long nr)
1959 return online_section(__nr_to_section(nr));
1962 #ifdef CONFIG_MEMORY_HOTPLUG
1963 void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
1964 void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
1967 static inline struct mem_section *__pfn_to_section(unsigned long pfn)
1969 return __nr_to_section(pfn_to_section_nr(pfn));
1972 extern unsigned long __highest_present_section_nr;
1974 static inline int subsection_map_index(unsigned long pfn)
1976 return (pfn & ~(PAGE_SECTION_MASK)) / PAGES_PER_SUBSECTION;
1979 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1980 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
1982 int idx = subsection_map_index(pfn);
1984 return test_bit(idx, READ_ONCE(ms->usage)->subsection_map);
1987 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
1993 #ifndef CONFIG_HAVE_ARCH_PFN_VALID
1995 * pfn_valid - check if there is a valid memory map entry for a PFN
1996 * @pfn: the page frame number to check
1998 * Check if there is a valid memory map entry aka struct page for the @pfn.
1999 * Note, that availability of the memory map entry does not imply that
2000 * there is actual usable memory at that @pfn. The struct page may
2001 * represent a hole or an unusable page frame.
2003 * Return: 1 for PFNs that have memory map entries and 0 otherwise
2005 static inline int pfn_valid(unsigned long pfn)
2007 struct mem_section *ms;
2011 * Ensure the upper PAGE_SHIFT bits are clear in the
2012 * pfn. Else it might lead to false positives when
2013 * some of the upper bits are set, but the lower bits
2014 * match a valid pfn.
2016 if (PHYS_PFN(PFN_PHYS(pfn)) != pfn)
2019 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
2021 ms = __pfn_to_section(pfn);
2022 rcu_read_lock_sched();
2023 if (!valid_section(ms)) {
2024 rcu_read_unlock_sched();
2028 * Traditionally early sections always returned pfn_valid() for
2029 * the entire section-sized span.
2031 ret = early_section(ms) || pfn_section_valid(ms, pfn);
2032 rcu_read_unlock_sched();
2038 static inline int pfn_in_present_section(unsigned long pfn)
2040 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
2042 return present_section(__pfn_to_section(pfn));
2045 static inline unsigned long next_present_section_nr(unsigned long section_nr)
2047 while (++section_nr <= __highest_present_section_nr) {
2048 if (present_section_nr(section_nr))
2056 * These are _only_ used during initialisation, therefore they
2057 * can use __initdata ... They could have names to indicate
2061 #define pfn_to_nid(pfn) \
2063 unsigned long __pfn_to_nid_pfn = (pfn); \
2064 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
2067 #define pfn_to_nid(pfn) (0)
2070 void sparse_init(void);
2072 #define sparse_init() do {} while (0)
2073 #define sparse_index_init(_sec, _nid) do {} while (0)
2074 #define pfn_in_present_section pfn_valid
2075 #define subsection_map_init(_pfn, _nr_pages) do {} while (0)
2076 #endif /* CONFIG_SPARSEMEM */
2078 #endif /* !__GENERATING_BOUNDS.H */
2079 #endif /* !__ASSEMBLY__ */
2080 #endif /* _LINUX_MMZONE_H */