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, e.g. KVM pagetables */
212 #ifdef CONFIG_NUMA_BALANCING
213 PGPROMOTE_SUCCESS, /* promote successfully */
214 PGPROMOTE_CANDIDATE, /* candidate pages to promote */
216 /* PGDEMOTE_*: pages demoted */
220 NR_VM_NODE_STAT_ITEMS
224 * Returns true if the item should be printed in THPs (/proc/vmstat
225 * currently prints number of anon, file and shmem THPs. But the item
226 * is charged in pages).
228 static __always_inline bool vmstat_item_print_in_thp(enum node_stat_item item)
230 if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
233 return item == NR_ANON_THPS ||
234 item == NR_FILE_THPS ||
235 item == NR_SHMEM_THPS ||
236 item == NR_SHMEM_PMDMAPPED ||
237 item == NR_FILE_PMDMAPPED;
241 * Returns true if the value is measured in bytes (most vmstat values are
242 * measured in pages). This defines the API part, the internal representation
243 * might be different.
245 static __always_inline bool vmstat_item_in_bytes(int idx)
248 * Global and per-node slab counters track slab pages.
249 * It's expected that changes are multiples of PAGE_SIZE.
250 * Internally values are stored in pages.
252 * Per-memcg and per-lruvec counters track memory, consumed
253 * by individual slab objects. These counters are actually
256 return (idx == NR_SLAB_RECLAIMABLE_B ||
257 idx == NR_SLAB_UNRECLAIMABLE_B);
261 * We do arithmetic on the LRU lists in various places in the code,
262 * so it is important to keep the active lists LRU_ACTIVE higher in
263 * the array than the corresponding inactive lists, and to keep
264 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
266 * This has to be kept in sync with the statistics in zone_stat_item
267 * above and the descriptions in vmstat_text in mm/vmstat.c
274 LRU_INACTIVE_ANON = LRU_BASE,
275 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
276 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
277 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
282 enum vmscan_throttle_state {
283 VMSCAN_THROTTLE_WRITEBACK,
284 VMSCAN_THROTTLE_ISOLATED,
285 VMSCAN_THROTTLE_NOPROGRESS,
286 VMSCAN_THROTTLE_CONGESTED,
290 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++)
292 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++)
294 static inline bool is_file_lru(enum lru_list lru)
296 return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE);
299 static inline bool is_active_lru(enum lru_list lru)
301 return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE);
304 #define WORKINGSET_ANON 0
305 #define WORKINGSET_FILE 1
306 #define ANON_AND_FILE 2
310 * An lruvec has many dirty pages backed by a congested BDI:
311 * 1. LRUVEC_CGROUP_CONGESTED is set by cgroup-level reclaim.
312 * It can be cleared by cgroup reclaim or kswapd.
313 * 2. LRUVEC_NODE_CONGESTED is set by kswapd node-level reclaim.
314 * It can only be cleared by kswapd.
316 * Essentially, kswapd can unthrottle an lruvec throttled by cgroup
317 * reclaim, but not vice versa. This only applies to the root cgroup.
318 * The goal is to prevent cgroup reclaim on the root cgroup (e.g.
319 * memory.reclaim) to unthrottle an unbalanced node (that was throttled
322 LRUVEC_CGROUP_CONGESTED,
323 LRUVEC_NODE_CONGESTED,
326 #endif /* !__GENERATING_BOUNDS_H */
329 * Evictable pages are divided into multiple generations. The youngest and the
330 * oldest generation numbers, max_seq and min_seq, are monotonically increasing.
331 * They form a sliding window of a variable size [MIN_NR_GENS, MAX_NR_GENS]. An
332 * offset within MAX_NR_GENS, i.e., gen, indexes the LRU list of the
333 * corresponding generation. The gen counter in folio->flags stores gen+1 while
334 * a page is on one of lrugen->folios[]. Otherwise it stores 0.
336 * A page is added to the youngest generation on faulting. The aging needs to
337 * check the accessed bit at least twice before handing this page over to the
338 * eviction. The first check takes care of the accessed bit set on the initial
339 * fault; the second check makes sure this page hasn't been used since then.
340 * This process, AKA second chance, requires a minimum of two generations,
341 * hence MIN_NR_GENS. And to maintain ABI compatibility with the active/inactive
342 * LRU, e.g., /proc/vmstat, these two generations are considered active; the
343 * rest of generations, if they exist, are considered inactive. See
344 * lru_gen_is_active().
346 * PG_active is always cleared while a page is on one of lrugen->folios[] so
347 * that the aging needs not to worry about it. And it's set again when a page
348 * considered active is isolated for non-reclaiming purposes, e.g., migration.
349 * See lru_gen_add_folio() and lru_gen_del_folio().
351 * MAX_NR_GENS is set to 4 so that the multi-gen LRU can support twice the
352 * number of categories of the active/inactive LRU when keeping track of
353 * accesses through page tables. This requires order_base_2(MAX_NR_GENS+1) bits
356 #define MIN_NR_GENS 2U
357 #define MAX_NR_GENS 4U
360 * Each generation is divided into multiple tiers. A page accessed N times
361 * through file descriptors is in tier order_base_2(N). A page in the first tier
362 * (N=0,1) is marked by PG_referenced unless it was faulted in through page
363 * tables or read ahead. A page in any other tier (N>1) is marked by
364 * PG_referenced and PG_workingset. This implies a minimum of two tiers is
365 * supported without using additional bits in folio->flags.
367 * In contrast to moving across generations which requires the LRU lock, moving
368 * across tiers only involves atomic operations on folio->flags and therefore
369 * has a negligible cost in the buffered access path. In the eviction path,
370 * comparisons of refaulted/(evicted+protected) from the first tier and the
371 * rest infer whether pages accessed multiple times through file descriptors
372 * are statistically hot and thus worth protecting.
374 * MAX_NR_TIERS is set to 4 so that the multi-gen LRU can support twice the
375 * number of categories of the active/inactive LRU when keeping track of
376 * accesses through file descriptors. This uses MAX_NR_TIERS-2 spare bits in
379 #define MAX_NR_TIERS 4U
381 #ifndef __GENERATING_BOUNDS_H
384 struct page_vma_mapped_walk;
386 #define LRU_GEN_MASK ((BIT(LRU_GEN_WIDTH) - 1) << LRU_GEN_PGOFF)
387 #define LRU_REFS_MASK ((BIT(LRU_REFS_WIDTH) - 1) << LRU_REFS_PGOFF)
389 #ifdef CONFIG_LRU_GEN
399 LRU_GEN_NONLEAF_YOUNG,
403 #define MIN_LRU_BATCH BITS_PER_LONG
404 #define MAX_LRU_BATCH (MIN_LRU_BATCH * 64)
406 /* whether to keep historical stats from evicted generations */
407 #ifdef CONFIG_LRU_GEN_STATS
408 #define NR_HIST_GENS MAX_NR_GENS
410 #define NR_HIST_GENS 1U
414 * The youngest generation number is stored in max_seq for both anon and file
415 * types as they are aged on an equal footing. The oldest generation numbers are
416 * stored in min_seq[] separately for anon and file types as clean file pages
417 * can be evicted regardless of swap constraints.
419 * Normally anon and file min_seq are in sync. But if swapping is constrained,
420 * e.g., out of swap space, file min_seq is allowed to advance and leave anon
423 * The number of pages in each generation is eventually consistent and therefore
424 * can be transiently negative when reset_batch_size() is pending.
426 struct lru_gen_folio {
427 /* the aging increments the youngest generation number */
428 unsigned long max_seq;
429 /* the eviction increments the oldest generation numbers */
430 unsigned long min_seq[ANON_AND_FILE];
431 /* the birth time of each generation in jiffies */
432 unsigned long timestamps[MAX_NR_GENS];
433 /* the multi-gen LRU lists, lazily sorted on eviction */
434 struct list_head folios[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES];
435 /* the multi-gen LRU sizes, eventually consistent */
436 long nr_pages[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES];
437 /* the exponential moving average of refaulted */
438 unsigned long avg_refaulted[ANON_AND_FILE][MAX_NR_TIERS];
439 /* the exponential moving average of evicted+protected */
440 unsigned long avg_total[ANON_AND_FILE][MAX_NR_TIERS];
441 /* the first tier doesn't need protection, hence the minus one */
442 unsigned long protected[NR_HIST_GENS][ANON_AND_FILE][MAX_NR_TIERS - 1];
443 /* can be modified without holding the LRU lock */
444 atomic_long_t evicted[NR_HIST_GENS][ANON_AND_FILE][MAX_NR_TIERS];
445 atomic_long_t refaulted[NR_HIST_GENS][ANON_AND_FILE][MAX_NR_TIERS];
446 /* whether the multi-gen LRU is enabled */
448 /* the memcg generation this lru_gen_folio belongs to */
450 /* the list segment this lru_gen_folio belongs to */
452 /* per-node lru_gen_folio list for global reclaim */
453 struct hlist_nulls_node list;
457 MM_LEAF_TOTAL, /* total leaf entries */
458 MM_LEAF_OLD, /* old leaf entries */
459 MM_LEAF_YOUNG, /* young leaf entries */
460 MM_NONLEAF_TOTAL, /* total non-leaf entries */
461 MM_NONLEAF_FOUND, /* non-leaf entries found in Bloom filters */
462 MM_NONLEAF_ADDED, /* non-leaf entries added to Bloom filters */
466 /* double-buffering Bloom filters */
467 #define NR_BLOOM_FILTERS 2
469 struct lru_gen_mm_state {
470 /* synced with max_seq after each iteration */
472 /* where the current iteration continues after */
473 struct list_head *head;
474 /* where the last iteration ended before */
475 struct list_head *tail;
476 /* Bloom filters flip after each iteration */
477 unsigned long *filters[NR_BLOOM_FILTERS];
478 /* the mm stats for debugging */
479 unsigned long stats[NR_HIST_GENS][NR_MM_STATS];
482 struct lru_gen_mm_walk {
483 /* the lruvec under reclaim */
484 struct lruvec *lruvec;
485 /* max_seq from lru_gen_folio: can be out of date */
487 /* the next address within an mm to scan */
488 unsigned long next_addr;
489 /* to batch promoted pages */
490 int nr_pages[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES];
491 /* to batch the mm stats */
492 int mm_stats[NR_MM_STATS];
493 /* total batched items */
500 * For each node, memcgs are divided into two generations: the old and the
501 * young. For each generation, memcgs are randomly sharded into multiple bins
502 * to improve scalability. For each bin, the hlist_nulls is virtually divided
503 * into three segments: the head, the tail and the default.
505 * An onlining memcg is added to the tail of a random bin in the old generation.
506 * The eviction starts at the head of a random bin in the old generation. The
507 * per-node memcg generation counter, whose reminder (mod MEMCG_NR_GENS) indexes
508 * the old generation, is incremented when all its bins become empty.
510 * There are four operations:
511 * 1. MEMCG_LRU_HEAD, which moves a memcg to the head of a random bin in its
512 * current generation (old or young) and updates its "seg" to "head";
513 * 2. MEMCG_LRU_TAIL, which moves a memcg to the tail of a random bin in its
514 * current generation (old or young) and updates its "seg" to "tail";
515 * 3. MEMCG_LRU_OLD, which moves a memcg to the head of a random bin in the old
516 * generation, updates its "gen" to "old" and resets its "seg" to "default";
517 * 4. MEMCG_LRU_YOUNG, which moves a memcg to the tail of a random bin in the
518 * young generation, updates its "gen" to "young" and resets its "seg" to
521 * The events that trigger the above operations are:
522 * 1. Exceeding the soft limit, which triggers MEMCG_LRU_HEAD;
523 * 2. The first attempt to reclaim a memcg below low, which triggers
525 * 3. The first attempt to reclaim a memcg offlined or below reclaimable size
526 * threshold, which triggers MEMCG_LRU_TAIL;
527 * 4. The second attempt to reclaim a memcg offlined or below reclaimable size
528 * threshold, which triggers MEMCG_LRU_YOUNG;
529 * 5. Attempting to reclaim a memcg below min, which triggers MEMCG_LRU_YOUNG;
530 * 6. Finishing the aging on the eviction path, which triggers MEMCG_LRU_YOUNG;
531 * 7. Offlining a memcg, which triggers MEMCG_LRU_OLD.
534 * 1. Memcg LRU only applies to global reclaim, and the round-robin incrementing
535 * of their max_seq counters ensures the eventual fairness to all eligible
536 * memcgs. For memcg reclaim, it still relies on mem_cgroup_iter().
537 * 2. There are only two valid generations: old (seq) and young (seq+1).
538 * MEMCG_NR_GENS is set to three so that when reading the generation counter
539 * locklessly, a stale value (seq-1) does not wraparound to young.
541 #define MEMCG_NR_GENS 3
542 #define MEMCG_NR_BINS 8
544 struct lru_gen_memcg {
545 /* the per-node memcg generation counter */
547 /* each memcg has one lru_gen_folio per node */
548 unsigned long nr_memcgs[MEMCG_NR_GENS];
549 /* per-node lru_gen_folio list for global reclaim */
550 struct hlist_nulls_head fifo[MEMCG_NR_GENS][MEMCG_NR_BINS];
551 /* protects the above */
555 void lru_gen_init_pgdat(struct pglist_data *pgdat);
556 void lru_gen_init_lruvec(struct lruvec *lruvec);
557 void lru_gen_look_around(struct page_vma_mapped_walk *pvmw);
559 void lru_gen_init_memcg(struct mem_cgroup *memcg);
560 void lru_gen_exit_memcg(struct mem_cgroup *memcg);
561 void lru_gen_online_memcg(struct mem_cgroup *memcg);
562 void lru_gen_offline_memcg(struct mem_cgroup *memcg);
563 void lru_gen_release_memcg(struct mem_cgroup *memcg);
564 void lru_gen_soft_reclaim(struct mem_cgroup *memcg, int nid);
566 #else /* !CONFIG_LRU_GEN */
568 static inline void lru_gen_init_pgdat(struct pglist_data *pgdat)
572 static inline void lru_gen_init_lruvec(struct lruvec *lruvec)
576 static inline void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
580 static inline void lru_gen_init_memcg(struct mem_cgroup *memcg)
584 static inline void lru_gen_exit_memcg(struct mem_cgroup *memcg)
588 static inline void lru_gen_online_memcg(struct mem_cgroup *memcg)
592 static inline void lru_gen_offline_memcg(struct mem_cgroup *memcg)
596 static inline void lru_gen_release_memcg(struct mem_cgroup *memcg)
600 static inline void lru_gen_soft_reclaim(struct mem_cgroup *memcg, int nid)
604 #endif /* CONFIG_LRU_GEN */
607 struct list_head lists[NR_LRU_LISTS];
608 /* per lruvec lru_lock for memcg */
611 * These track the cost of reclaiming one LRU - file or anon -
612 * over the other. As the observed cost of reclaiming one LRU
613 * increases, the reclaim scan balance tips toward the other.
615 unsigned long anon_cost;
616 unsigned long file_cost;
617 /* Non-resident age, driven by LRU movement */
618 atomic_long_t nonresident_age;
619 /* Refaults at the time of last reclaim cycle */
620 unsigned long refaults[ANON_AND_FILE];
621 /* Various lruvec state flags (enum lruvec_flags) */
623 #ifdef CONFIG_LRU_GEN
624 /* evictable pages divided into generations */
625 struct lru_gen_folio lrugen;
626 #ifdef CONFIG_LRU_GEN_WALKS_MMU
627 /* to concurrently iterate lru_gen_mm_list */
628 struct lru_gen_mm_state mm_state;
630 #endif /* CONFIG_LRU_GEN */
632 struct pglist_data *pgdat;
634 struct zswap_lruvec_state zswap_lruvec_state;
637 /* Isolate for asynchronous migration */
638 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4)
639 /* Isolate unevictable pages */
640 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8)
642 /* LRU Isolation modes. */
643 typedef unsigned __bitwise isolate_mode_t;
645 enum zone_watermarks {
654 * One per migratetype for each PAGE_ALLOC_COSTLY_ORDER. One additional list
655 * for THP which will usually be GFP_MOVABLE. Even if it is another type,
656 * it should not contribute to serious fragmentation causing THP allocation
659 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
664 #define NR_LOWORDER_PCP_LISTS (MIGRATE_PCPTYPES * (PAGE_ALLOC_COSTLY_ORDER + 1))
665 #define NR_PCP_LISTS (NR_LOWORDER_PCP_LISTS + NR_PCP_THP)
667 #define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost)
668 #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost)
669 #define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost)
670 #define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost)
673 * Flags used in pcp->flags field.
675 * PCPF_PREV_FREE_HIGH_ORDER: a high-order page is freed in the
676 * previous page freeing. To avoid to drain PCP for an accident
677 * high-order page freeing.
679 * PCPF_FREE_HIGH_BATCH: preserve "pcp->batch" pages in PCP before
680 * draining PCP for consecutive high-order pages freeing without
681 * allocation if data cache slice of CPU is large enough. To reduce
682 * zone lock contention and keep cache-hot pages reusing.
684 #define PCPF_PREV_FREE_HIGH_ORDER BIT(0)
685 #define PCPF_FREE_HIGH_BATCH BIT(1)
687 struct per_cpu_pages {
688 spinlock_t lock; /* Protects lists field */
689 int count; /* number of pages in the list */
690 int high; /* high watermark, emptying needed */
691 int high_min; /* min high watermark */
692 int high_max; /* max high watermark */
693 int batch; /* chunk size for buddy add/remove */
694 u8 flags; /* protected by pcp->lock */
695 u8 alloc_factor; /* batch scaling factor during allocate */
697 u8 expire; /* When 0, remote pagesets are drained */
699 short free_count; /* consecutive free count */
701 /* Lists of pages, one per migrate type stored on the pcp-lists */
702 struct list_head lists[NR_PCP_LISTS];
703 } ____cacheline_aligned_in_smp;
705 struct per_cpu_zonestat {
707 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
712 * Low priority inaccurate counters that are only folded
713 * on demand. Use a large type to avoid the overhead of
714 * folding during refresh_cpu_vm_stats.
716 unsigned long vm_numa_event[NR_VM_NUMA_EVENT_ITEMS];
720 struct per_cpu_nodestat {
722 s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS];
725 #endif /* !__GENERATING_BOUNDS.H */
729 * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able
730 * to DMA to all of the addressable memory (ZONE_NORMAL).
731 * On architectures where this area covers the whole 32 bit address
732 * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller
733 * DMA addressing constraints. This distinction is important as a 32bit
734 * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit
735 * platforms may need both zones as they support peripherals with
736 * different DMA addressing limitations.
738 #ifdef CONFIG_ZONE_DMA
741 #ifdef CONFIG_ZONE_DMA32
745 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
746 * performed on pages in ZONE_NORMAL if the DMA devices support
747 * transfers to all addressable memory.
750 #ifdef CONFIG_HIGHMEM
752 * A memory area that is only addressable by the kernel through
753 * mapping portions into its own address space. This is for example
754 * used by i386 to allow the kernel to address the memory beyond
755 * 900MB. The kernel will set up special mappings (page
756 * table entries on i386) for each page that the kernel needs to
762 * ZONE_MOVABLE is similar to ZONE_NORMAL, except that it contains
763 * movable pages with few exceptional cases described below. Main use
764 * cases for ZONE_MOVABLE are to make memory offlining/unplug more
765 * likely to succeed, and to locally limit unmovable allocations - e.g.,
766 * to increase the number of THP/huge pages. Notable special cases are:
768 * 1. Pinned pages: (long-term) pinning of movable pages might
769 * essentially turn such pages unmovable. Therefore, we do not allow
770 * pinning long-term pages in ZONE_MOVABLE. When pages are pinned and
771 * faulted, they come from the right zone right away. However, it is
772 * still possible that address space already has pages in
773 * ZONE_MOVABLE at the time when pages are pinned (i.e. user has
774 * touches that memory before pinning). In such case we migrate them
775 * to a different zone. When migration fails - pinning fails.
776 * 2. memblock allocations: kernelcore/movablecore setups might create
777 * situations where ZONE_MOVABLE contains unmovable allocations
778 * after boot. Memory offlining and allocations fail early.
779 * 3. Memory holes: kernelcore/movablecore setups might create very rare
780 * situations where ZONE_MOVABLE contains memory holes after boot,
781 * for example, if we have sections that are only partially
782 * populated. Memory offlining and allocations fail early.
783 * 4. PG_hwpoison pages: while poisoned pages can be skipped during
784 * memory offlining, such pages cannot be allocated.
785 * 5. Unmovable PG_offline pages: in paravirtualized environments,
786 * hotplugged memory blocks might only partially be managed by the
787 * buddy (e.g., via XEN-balloon, Hyper-V balloon, virtio-mem). The
788 * parts not manged by the buddy are unmovable PG_offline pages. In
789 * some cases (virtio-mem), such pages can be skipped during
790 * memory offlining, however, cannot be moved/allocated. These
791 * techniques might use alloc_contig_range() to hide previously
792 * exposed pages from the buddy again (e.g., to implement some sort
793 * of memory unplug in virtio-mem).
794 * 6. ZERO_PAGE(0), kernelcore/movablecore setups might create
795 * situations where ZERO_PAGE(0) which is allocated differently
796 * on different platforms may end up in a movable zone. ZERO_PAGE(0)
797 * cannot be migrated.
798 * 7. Memory-hotplug: when using memmap_on_memory and onlining the
799 * memory to the MOVABLE zone, the vmemmap pages are also placed in
800 * such zone. Such pages cannot be really moved around as they are
801 * self-stored in the range, but they are treated as movable when
802 * the range they describe is about to be offlined.
804 * In general, no unmovable allocations that degrade memory offlining
805 * should end up in ZONE_MOVABLE. Allocators (like alloc_contig_range())
806 * have to expect that migrating pages in ZONE_MOVABLE can fail (even
807 * if has_unmovable_pages() states that there are no unmovable pages,
808 * there can be false negatives).
811 #ifdef CONFIG_ZONE_DEVICE
818 #ifndef __GENERATING_BOUNDS_H
820 #define ASYNC_AND_SYNC 2
823 /* Read-mostly fields */
825 /* zone watermarks, access with *_wmark_pages(zone) macros */
826 unsigned long _watermark[NR_WMARK];
827 unsigned long watermark_boost;
829 unsigned long nr_reserved_highatomic;
832 * We don't know if the memory that we're going to allocate will be
833 * freeable or/and it will be released eventually, so to avoid totally
834 * wasting several GB of ram we must reserve some of the lower zone
835 * memory (otherwise we risk to run OOM on the lower zones despite
836 * there being tons of freeable ram on the higher zones). This array is
837 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl
840 long lowmem_reserve[MAX_NR_ZONES];
845 struct pglist_data *zone_pgdat;
846 struct per_cpu_pages __percpu *per_cpu_pageset;
847 struct per_cpu_zonestat __percpu *per_cpu_zonestats;
849 * the high and batch values are copied to individual pagesets for
852 int pageset_high_min;
853 int pageset_high_max;
856 #ifndef CONFIG_SPARSEMEM
858 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
859 * In SPARSEMEM, this map is stored in struct mem_section
861 unsigned long *pageblock_flags;
862 #endif /* CONFIG_SPARSEMEM */
864 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
865 unsigned long zone_start_pfn;
868 * spanned_pages is the total pages spanned by the zone, including
869 * holes, which is calculated as:
870 * spanned_pages = zone_end_pfn - zone_start_pfn;
872 * present_pages is physical pages existing within the zone, which
874 * present_pages = spanned_pages - absent_pages(pages in holes);
876 * present_early_pages is present pages existing within the zone
877 * located on memory available since early boot, excluding hotplugged
880 * managed_pages is present pages managed by the buddy system, which
881 * is calculated as (reserved_pages includes pages allocated by the
882 * bootmem allocator):
883 * managed_pages = present_pages - reserved_pages;
885 * cma pages is present pages that are assigned for CMA use
888 * So present_pages may be used by memory hotplug or memory power
889 * management logic to figure out unmanaged pages by checking
890 * (present_pages - managed_pages). And managed_pages should be used
891 * by page allocator and vm scanner to calculate all kinds of watermarks
896 * zone_start_pfn and spanned_pages are protected by span_seqlock.
897 * It is a seqlock because it has to be read outside of zone->lock,
898 * and it is done in the main allocator path. But, it is written
899 * quite infrequently.
901 * The span_seq lock is declared along with zone->lock because it is
902 * frequently read in proximity to zone->lock. It's good to
903 * give them a chance of being in the same cacheline.
905 * Write access to present_pages at runtime should be protected by
906 * mem_hotplug_begin/done(). Any reader who can't tolerant drift of
907 * present_pages should use get_online_mems() to get a stable value.
909 atomic_long_t managed_pages;
910 unsigned long spanned_pages;
911 unsigned long present_pages;
912 #if defined(CONFIG_MEMORY_HOTPLUG)
913 unsigned long present_early_pages;
916 unsigned long cma_pages;
921 #ifdef CONFIG_MEMORY_ISOLATION
923 * Number of isolated pageblock. It is used to solve incorrect
924 * freepage counting problem due to racy retrieving migratetype
925 * of pageblock. Protected by zone->lock.
927 unsigned long nr_isolate_pageblock;
930 #ifdef CONFIG_MEMORY_HOTPLUG
931 /* see spanned/present_pages for more description */
932 seqlock_t span_seqlock;
937 /* Write-intensive fields used from the page allocator */
938 CACHELINE_PADDING(_pad1_);
940 /* free areas of different sizes */
941 struct free_area free_area[NR_PAGE_ORDERS];
943 #ifdef CONFIG_UNACCEPTED_MEMORY
944 /* Pages to be accepted. All pages on the list are MAX_PAGE_ORDER */
945 struct list_head unaccepted_pages;
948 /* zone flags, see below */
951 /* Primarily protects free_area */
954 /* Write-intensive fields used by compaction and vmstats. */
955 CACHELINE_PADDING(_pad2_);
958 * When free pages are below this point, additional steps are taken
959 * when reading the number of free pages to avoid per-cpu counter
960 * drift allowing watermarks to be breached
962 unsigned long percpu_drift_mark;
964 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
965 /* pfn where compaction free scanner should start */
966 unsigned long compact_cached_free_pfn;
967 /* pfn where compaction migration scanner should start */
968 unsigned long compact_cached_migrate_pfn[ASYNC_AND_SYNC];
969 unsigned long compact_init_migrate_pfn;
970 unsigned long compact_init_free_pfn;
973 #ifdef CONFIG_COMPACTION
975 * On compaction failure, 1<<compact_defer_shift compactions
976 * are skipped before trying again. The number attempted since
977 * last failure is tracked with compact_considered.
978 * compact_order_failed is the minimum compaction failed order.
980 unsigned int compact_considered;
981 unsigned int compact_defer_shift;
982 int compact_order_failed;
985 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
986 /* Set to true when the PG_migrate_skip bits should be cleared */
987 bool compact_blockskip_flush;
992 CACHELINE_PADDING(_pad3_);
993 /* Zone statistics */
994 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
995 atomic_long_t vm_numa_event[NR_VM_NUMA_EVENT_ITEMS];
996 } ____cacheline_internodealigned_in_smp;
999 PGDAT_DIRTY, /* reclaim scanning has recently found
1000 * many dirty file pages at the tail
1003 PGDAT_WRITEBACK, /* reclaim scanning has recently found
1004 * many pages under writeback
1006 PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */
1010 ZONE_BOOSTED_WATERMARK, /* zone recently boosted watermarks.
1011 * Cleared when kswapd is woken.
1013 ZONE_RECLAIM_ACTIVE, /* kswapd may be scanning the zone. */
1014 ZONE_BELOW_HIGH, /* zone is below high watermark. */
1017 static inline unsigned long zone_managed_pages(struct zone *zone)
1019 return (unsigned long)atomic_long_read(&zone->managed_pages);
1022 static inline unsigned long zone_cma_pages(struct zone *zone)
1025 return zone->cma_pages;
1031 static inline unsigned long zone_end_pfn(const struct zone *zone)
1033 return zone->zone_start_pfn + zone->spanned_pages;
1036 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)
1038 return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone);
1041 static inline bool zone_is_initialized(struct zone *zone)
1043 return zone->initialized;
1046 static inline bool zone_is_empty(struct zone *zone)
1048 return zone->spanned_pages == 0;
1051 #ifndef BUILD_VDSO32_64
1053 * The zone field is never updated after free_area_init_core()
1054 * sets it, so none of the operations on it need to be atomic.
1057 /* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_CPUPID] | ... | FLAGS | */
1058 #define SECTIONS_PGOFF ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
1059 #define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH)
1060 #define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH)
1061 #define LAST_CPUPID_PGOFF (ZONES_PGOFF - LAST_CPUPID_WIDTH)
1062 #define KASAN_TAG_PGOFF (LAST_CPUPID_PGOFF - KASAN_TAG_WIDTH)
1063 #define LRU_GEN_PGOFF (KASAN_TAG_PGOFF - LRU_GEN_WIDTH)
1064 #define LRU_REFS_PGOFF (LRU_GEN_PGOFF - LRU_REFS_WIDTH)
1067 * Define the bit shifts to access each section. For non-existent
1068 * sections we define the shift as 0; that plus a 0 mask ensures
1069 * the compiler will optimise away reference to them.
1071 #define SECTIONS_PGSHIFT (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
1072 #define NODES_PGSHIFT (NODES_PGOFF * (NODES_WIDTH != 0))
1073 #define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_WIDTH != 0))
1074 #define LAST_CPUPID_PGSHIFT (LAST_CPUPID_PGOFF * (LAST_CPUPID_WIDTH != 0))
1075 #define KASAN_TAG_PGSHIFT (KASAN_TAG_PGOFF * (KASAN_TAG_WIDTH != 0))
1077 /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */
1078 #ifdef NODE_NOT_IN_PAGE_FLAGS
1079 #define ZONEID_SHIFT (SECTIONS_SHIFT + ZONES_SHIFT)
1080 #define ZONEID_PGOFF ((SECTIONS_PGOFF < ZONES_PGOFF) ? \
1081 SECTIONS_PGOFF : ZONES_PGOFF)
1083 #define ZONEID_SHIFT (NODES_SHIFT + ZONES_SHIFT)
1084 #define ZONEID_PGOFF ((NODES_PGOFF < ZONES_PGOFF) ? \
1085 NODES_PGOFF : ZONES_PGOFF)
1088 #define ZONEID_PGSHIFT (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
1090 #define ZONES_MASK ((1UL << ZONES_WIDTH) - 1)
1091 #define NODES_MASK ((1UL << NODES_WIDTH) - 1)
1092 #define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1)
1093 #define LAST_CPUPID_MASK ((1UL << LAST_CPUPID_SHIFT) - 1)
1094 #define KASAN_TAG_MASK ((1UL << KASAN_TAG_WIDTH) - 1)
1095 #define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1)
1097 static inline enum zone_type page_zonenum(const struct page *page)
1099 ASSERT_EXCLUSIVE_BITS(page->flags, ZONES_MASK << ZONES_PGSHIFT);
1100 return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
1103 static inline enum zone_type folio_zonenum(const struct folio *folio)
1105 return page_zonenum(&folio->page);
1108 #ifdef CONFIG_ZONE_DEVICE
1109 static inline bool is_zone_device_page(const struct page *page)
1111 return page_zonenum(page) == ZONE_DEVICE;
1115 * Consecutive zone device pages should not be merged into the same sgl
1116 * or bvec segment with other types of pages or if they belong to different
1117 * pgmaps. Otherwise getting the pgmap of a given segment is not possible
1118 * without scanning the entire segment. This helper returns true either if
1119 * both pages are not zone device pages or both pages are zone device pages
1120 * with the same pgmap.
1122 static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
1123 const struct page *b)
1125 if (is_zone_device_page(a) != is_zone_device_page(b))
1127 if (!is_zone_device_page(a))
1129 return a->pgmap == b->pgmap;
1132 extern void memmap_init_zone_device(struct zone *, unsigned long,
1133 unsigned long, struct dev_pagemap *);
1135 static inline bool is_zone_device_page(const struct page *page)
1139 static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
1140 const struct page *b)
1146 static inline bool folio_is_zone_device(const struct folio *folio)
1148 return is_zone_device_page(&folio->page);
1151 static inline bool is_zone_movable_page(const struct page *page)
1153 return page_zonenum(page) == ZONE_MOVABLE;
1156 static inline bool folio_is_zone_movable(const struct folio *folio)
1158 return folio_zonenum(folio) == ZONE_MOVABLE;
1163 * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty
1164 * intersection with the given zone
1166 static inline bool zone_intersects(struct zone *zone,
1167 unsigned long start_pfn, unsigned long nr_pages)
1169 if (zone_is_empty(zone))
1171 if (start_pfn >= zone_end_pfn(zone) ||
1172 start_pfn + nr_pages <= zone->zone_start_pfn)
1179 * The "priority" of VM scanning is how much of the queues we will scan in one
1180 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
1181 * queues ("queue_length >> 12") during an aging round.
1183 #define DEF_PRIORITY 12
1185 /* Maximum number of zones on a zonelist */
1186 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
1189 ZONELIST_FALLBACK, /* zonelist with fallback */
1192 * The NUMA zonelists are doubled because we need zonelists that
1193 * restrict the allocations to a single node for __GFP_THISNODE.
1195 ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */
1201 * This struct contains information about a zone in a zonelist. It is stored
1202 * here to avoid dereferences into large structures and lookups of tables
1205 struct zone *zone; /* Pointer to actual zone */
1206 int zone_idx; /* zone_idx(zoneref->zone) */
1210 * One allocation request operates on a zonelist. A zonelist
1211 * is a list of zones, the first one is the 'goal' of the
1212 * allocation, the other zones are fallback zones, in decreasing
1215 * To speed the reading of the zonelist, the zonerefs contain the zone index
1216 * of the entry being read. Helper functions to access information given
1217 * a struct zoneref are
1219 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
1220 * zonelist_zone_idx() - Return the index of the zone for an entry
1221 * zonelist_node_idx() - Return the index of the node for an entry
1224 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
1228 * The array of struct pages for flatmem.
1229 * It must be declared for SPARSEMEM as well because there are configurations
1230 * that rely on that.
1232 extern struct page *mem_map;
1234 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1235 struct deferred_split {
1236 spinlock_t split_queue_lock;
1237 struct list_head split_queue;
1238 unsigned long split_queue_len;
1242 #ifdef CONFIG_MEMORY_FAILURE
1244 * Per NUMA node memory failure handling statistics.
1246 struct memory_failure_stats {
1248 * Number of raw pages poisoned.
1249 * Cases not accounted: memory outside kernel control, offline page,
1250 * arch-specific memory_failure (SGX), hwpoison_filter() filtered
1251 * error events, and unpoison actions from hwpoison_unpoison.
1253 unsigned long total;
1255 * Recovery results of poisoned raw pages handled by memory_failure,
1256 * in sync with mf_result.
1257 * total = ignored + failed + delayed + recovered.
1258 * total * PAGE_SIZE * #nodes = /proc/meminfo/HardwareCorrupted.
1260 unsigned long ignored;
1261 unsigned long failed;
1262 unsigned long delayed;
1263 unsigned long recovered;
1268 * On NUMA machines, each NUMA node would have a pg_data_t to describe
1269 * it's memory layout. On UMA machines there is a single pglist_data which
1270 * describes the whole memory.
1272 * Memory statistics and page replacement data structures are maintained on a
1275 typedef struct pglist_data {
1277 * node_zones contains just the zones for THIS node. Not all of the
1278 * zones may be populated, but it is the full list. It is referenced by
1279 * this node's node_zonelists as well as other node's node_zonelists.
1281 struct zone node_zones[MAX_NR_ZONES];
1284 * node_zonelists contains references to all zones in all nodes.
1285 * Generally the first zones will be references to this node's
1288 struct zonelist node_zonelists[MAX_ZONELISTS];
1290 int nr_zones; /* number of populated zones in this node */
1291 #ifdef CONFIG_FLATMEM /* means !SPARSEMEM */
1292 struct page *node_mem_map;
1293 #ifdef CONFIG_PAGE_EXTENSION
1294 struct page_ext *node_page_ext;
1297 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
1299 * Must be held any time you expect node_start_pfn,
1300 * node_present_pages, node_spanned_pages or nr_zones to stay constant.
1301 * Also synchronizes pgdat->first_deferred_pfn during deferred page
1304 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to
1305 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG
1306 * or CONFIG_DEFERRED_STRUCT_PAGE_INIT.
1308 * Nests above zone->lock and zone->span_seqlock
1310 spinlock_t node_size_lock;
1312 unsigned long node_start_pfn;
1313 unsigned long node_present_pages; /* total number of physical pages */
1314 unsigned long node_spanned_pages; /* total size of physical page
1315 range, including holes */
1317 wait_queue_head_t kswapd_wait;
1318 wait_queue_head_t pfmemalloc_wait;
1320 /* workqueues for throttling reclaim for different reasons. */
1321 wait_queue_head_t reclaim_wait[NR_VMSCAN_THROTTLE];
1323 atomic_t nr_writeback_throttled;/* nr of writeback-throttled tasks */
1324 unsigned long nr_reclaim_start; /* nr pages written while throttled
1325 * when throttling started. */
1326 #ifdef CONFIG_MEMORY_HOTPLUG
1327 struct mutex kswapd_lock;
1329 struct task_struct *kswapd; /* Protected by kswapd_lock */
1331 enum zone_type kswapd_highest_zoneidx;
1333 int kswapd_failures; /* Number of 'reclaimed == 0' runs */
1335 #ifdef CONFIG_COMPACTION
1336 int kcompactd_max_order;
1337 enum zone_type kcompactd_highest_zoneidx;
1338 wait_queue_head_t kcompactd_wait;
1339 struct task_struct *kcompactd;
1340 bool proactive_compact_trigger;
1343 * This is a per-node reserve of pages that are not available
1344 * to userspace allocations.
1346 unsigned long totalreserve_pages;
1350 * node reclaim becomes active if more unmapped pages exist.
1352 unsigned long min_unmapped_pages;
1353 unsigned long min_slab_pages;
1354 #endif /* CONFIG_NUMA */
1356 /* Write-intensive fields used by page reclaim */
1357 CACHELINE_PADDING(_pad1_);
1359 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
1361 * If memory initialisation on large machines is deferred then this
1362 * is the first PFN that needs to be initialised.
1364 unsigned long first_deferred_pfn;
1365 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
1367 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1368 struct deferred_split deferred_split_queue;
1371 #ifdef CONFIG_NUMA_BALANCING
1372 /* start time in ms of current promote rate limit period */
1373 unsigned int nbp_rl_start;
1374 /* number of promote candidate pages at start time of current rate limit period */
1375 unsigned long nbp_rl_nr_cand;
1376 /* promote threshold in ms */
1377 unsigned int nbp_threshold;
1378 /* start time in ms of current promote threshold adjustment period */
1379 unsigned int nbp_th_start;
1381 * number of promote candidate pages at start time of current promote
1382 * threshold adjustment period
1384 unsigned long nbp_th_nr_cand;
1386 /* Fields commonly accessed by the page reclaim scanner */
1389 * NOTE: THIS IS UNUSED IF MEMCG IS ENABLED.
1391 * Use mem_cgroup_lruvec() to look up lruvecs.
1393 struct lruvec __lruvec;
1395 unsigned long flags;
1397 #ifdef CONFIG_LRU_GEN
1398 /* kswap mm walk data */
1399 struct lru_gen_mm_walk mm_walk;
1400 /* lru_gen_folio list */
1401 struct lru_gen_memcg memcg_lru;
1404 CACHELINE_PADDING(_pad2_);
1406 /* Per-node vmstats */
1407 struct per_cpu_nodestat __percpu *per_cpu_nodestats;
1408 atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS];
1410 struct memory_tier __rcu *memtier;
1412 #ifdef CONFIG_MEMORY_FAILURE
1413 struct memory_failure_stats mf_stats;
1417 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
1418 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
1420 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn)
1421 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))
1423 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat)
1425 return pgdat->node_start_pfn + pgdat->node_spanned_pages;
1428 #include <linux/memory_hotplug.h>
1430 void build_all_zonelists(pg_data_t *pgdat);
1431 void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order,
1432 enum zone_type highest_zoneidx);
1433 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
1434 int highest_zoneidx, unsigned int alloc_flags,
1436 bool zone_watermark_ok(struct zone *z, unsigned int order,
1437 unsigned long mark, int highest_zoneidx,
1438 unsigned int alloc_flags);
1439 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
1440 unsigned long mark, int highest_zoneidx);
1442 * Memory initialization context, use to differentiate memory added by
1443 * the platform statically or via memory hotplug interface.
1445 enum meminit_context {
1450 extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
1451 unsigned long size);
1453 extern void lruvec_init(struct lruvec *lruvec);
1455 static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec)
1458 return lruvec->pgdat;
1460 return container_of(lruvec, struct pglist_data, __lruvec);
1464 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
1465 int local_memory_node(int node_id);
1467 static inline int local_memory_node(int node_id) { return node_id; };
1471 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
1473 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
1475 #ifdef CONFIG_ZONE_DEVICE
1476 static inline bool zone_is_zone_device(struct zone *zone)
1478 return zone_idx(zone) == ZONE_DEVICE;
1481 static inline bool zone_is_zone_device(struct zone *zone)
1488 * Returns true if a zone has pages managed by the buddy allocator.
1489 * All the reclaim decisions have to use this function rather than
1490 * populated_zone(). If the whole zone is reserved then we can easily
1491 * end up with populated_zone() && !managed_zone().
1493 static inline bool managed_zone(struct zone *zone)
1495 return zone_managed_pages(zone);
1498 /* Returns true if a zone has memory */
1499 static inline bool populated_zone(struct zone *zone)
1501 return zone->present_pages;
1505 static inline int zone_to_nid(struct zone *zone)
1510 static inline void zone_set_nid(struct zone *zone, int nid)
1515 static inline int zone_to_nid(struct zone *zone)
1520 static inline void zone_set_nid(struct zone *zone, int nid) {}
1523 extern int movable_zone;
1525 static inline int is_highmem_idx(enum zone_type idx)
1527 #ifdef CONFIG_HIGHMEM
1528 return (idx == ZONE_HIGHMEM ||
1529 (idx == ZONE_MOVABLE && movable_zone == ZONE_HIGHMEM));
1536 * is_highmem - helper function to quickly check if a struct zone is a
1537 * highmem zone or not. This is an attempt to keep references
1538 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
1539 * @zone: pointer to struct zone variable
1540 * Return: 1 for a highmem zone, 0 otherwise
1542 static inline int is_highmem(struct zone *zone)
1544 return is_highmem_idx(zone_idx(zone));
1547 #ifdef CONFIG_ZONE_DMA
1548 bool has_managed_dma(void);
1550 static inline bool has_managed_dma(void)
1559 extern struct pglist_data contig_page_data;
1560 static inline struct pglist_data *NODE_DATA(int nid)
1562 return &contig_page_data;
1565 #else /* CONFIG_NUMA */
1567 #include <asm/mmzone.h>
1569 #endif /* !CONFIG_NUMA */
1571 extern struct pglist_data *first_online_pgdat(void);
1572 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
1573 extern struct zone *next_zone(struct zone *zone);
1576 * for_each_online_pgdat - helper macro to iterate over all online nodes
1577 * @pgdat: pointer to a pg_data_t variable
1579 #define for_each_online_pgdat(pgdat) \
1580 for (pgdat = first_online_pgdat(); \
1582 pgdat = next_online_pgdat(pgdat))
1584 * for_each_zone - helper macro to iterate over all memory zones
1585 * @zone: pointer to struct zone variable
1587 * The user only needs to declare the zone variable, for_each_zone
1590 #define for_each_zone(zone) \
1591 for (zone = (first_online_pgdat())->node_zones; \
1593 zone = next_zone(zone))
1595 #define for_each_populated_zone(zone) \
1596 for (zone = (first_online_pgdat())->node_zones; \
1598 zone = next_zone(zone)) \
1599 if (!populated_zone(zone)) \
1600 ; /* do nothing */ \
1603 static inline struct zone *zonelist_zone(struct zoneref *zoneref)
1605 return zoneref->zone;
1608 static inline int zonelist_zone_idx(struct zoneref *zoneref)
1610 return zoneref->zone_idx;
1613 static inline int zonelist_node_idx(struct zoneref *zoneref)
1615 return zone_to_nid(zoneref->zone);
1618 struct zoneref *__next_zones_zonelist(struct zoneref *z,
1619 enum zone_type highest_zoneidx,
1623 * 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
1624 * @z: The cursor used as a starting point for the search
1625 * @highest_zoneidx: The zone index of the highest zone to return
1626 * @nodes: An optional nodemask to filter the zonelist with
1628 * This function returns the next zone at or below a given zone index that is
1629 * within the allowed nodemask using a cursor as the starting point for the
1630 * search. The zoneref returned is a cursor that represents the current zone
1631 * being examined. It should be advanced by one before calling
1632 * next_zones_zonelist again.
1634 * Return: the next zone at or below highest_zoneidx within the allowed
1635 * nodemask using a cursor within a zonelist as a starting point
1637 static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z,
1638 enum zone_type highest_zoneidx,
1641 if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx))
1643 return __next_zones_zonelist(z, highest_zoneidx, nodes);
1647 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
1648 * @zonelist: The zonelist to search for a suitable zone
1649 * @highest_zoneidx: The zone index of the highest zone to return
1650 * @nodes: An optional nodemask to filter the zonelist with
1652 * This function returns the first zone at or below a given zone index that is
1653 * within the allowed nodemask. The zoneref returned is a cursor that can be
1654 * used to iterate the zonelist with next_zones_zonelist by advancing it by
1655 * one before calling.
1657 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is
1658 * never NULL). This may happen either genuinely, or due to concurrent nodemask
1659 * update due to cpuset modification.
1661 * Return: Zoneref pointer for the first suitable zone found
1663 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
1664 enum zone_type highest_zoneidx,
1667 return next_zones_zonelist(zonelist->_zonerefs,
1668 highest_zoneidx, nodes);
1672 * 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
1673 * @zone: The current zone in the iterator
1674 * @z: The current pointer within zonelist->_zonerefs being iterated
1675 * @zlist: The zonelist being iterated
1676 * @highidx: The zone index of the highest zone to return
1677 * @nodemask: Nodemask allowed by the allocator
1679 * This iterator iterates though all zones at or below a given zone index and
1680 * within a given nodemask
1682 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
1683 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \
1685 z = next_zones_zonelist(++z, highidx, nodemask), \
1686 zone = zonelist_zone(z))
1688 #define for_next_zone_zonelist_nodemask(zone, z, highidx, nodemask) \
1689 for (zone = z->zone; \
1691 z = next_zones_zonelist(++z, highidx, nodemask), \
1692 zone = zonelist_zone(z))
1696 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
1697 * @zone: The current zone in the iterator
1698 * @z: The current pointer within zonelist->zones being iterated
1699 * @zlist: The zonelist being iterated
1700 * @highidx: The zone index of the highest zone to return
1702 * This iterator iterates though all zones at or below a given zone index.
1704 #define for_each_zone_zonelist(zone, z, zlist, highidx) \
1705 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
1707 /* Whether the 'nodes' are all movable nodes */
1708 static inline bool movable_only_nodes(nodemask_t *nodes)
1710 struct zonelist *zonelist;
1714 if (nodes_empty(*nodes))
1718 * We can chose arbitrary node from the nodemask to get a
1719 * zonelist as they are interlinked. We just need to find
1720 * at least one zone that can satisfy kernel allocations.
1722 nid = first_node(*nodes);
1723 zonelist = &NODE_DATA(nid)->node_zonelists[ZONELIST_FALLBACK];
1724 z = first_zones_zonelist(zonelist, ZONE_NORMAL, nodes);
1725 return (!z->zone) ? true : false;
1729 #ifdef CONFIG_SPARSEMEM
1730 #include <asm/sparsemem.h>
1733 #ifdef CONFIG_FLATMEM
1734 #define pfn_to_nid(pfn) (0)
1737 #ifdef CONFIG_SPARSEMEM
1740 * PA_SECTION_SHIFT physical address to/from section number
1741 * PFN_SECTION_SHIFT pfn to/from section number
1743 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
1744 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
1746 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
1748 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
1749 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
1751 #define SECTION_BLOCKFLAGS_BITS \
1752 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
1754 #if (MAX_PAGE_ORDER + PAGE_SHIFT) > SECTION_SIZE_BITS
1755 #error Allocator MAX_PAGE_ORDER exceeds SECTION_SIZE
1758 static inline unsigned long pfn_to_section_nr(unsigned long pfn)
1760 return pfn >> PFN_SECTION_SHIFT;
1762 static inline unsigned long section_nr_to_pfn(unsigned long sec)
1764 return sec << PFN_SECTION_SHIFT;
1767 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)
1768 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK)
1770 #define SUBSECTION_SHIFT 21
1771 #define SUBSECTION_SIZE (1UL << SUBSECTION_SHIFT)
1773 #define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT)
1774 #define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT)
1775 #define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1))
1777 #if SUBSECTION_SHIFT > SECTION_SIZE_BITS
1778 #error Subsection size exceeds section size
1780 #define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT))
1783 #define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION)
1784 #define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK)
1786 struct mem_section_usage {
1787 struct rcu_head rcu;
1788 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1789 DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION);
1791 /* See declaration of similar field in struct zone */
1792 unsigned long pageblock_flags[0];
1795 void subsection_map_init(unsigned long pfn, unsigned long nr_pages);
1799 struct mem_section {
1801 * This is, logically, a pointer to an array of struct
1802 * pages. However, it is stored with some other magic.
1803 * (see sparse.c::sparse_init_one_section())
1805 * Additionally during early boot we encode node id of
1806 * the location of the section here to guide allocation.
1807 * (see sparse.c::memory_present())
1809 * Making it a UL at least makes someone do a cast
1810 * before using it wrong.
1812 unsigned long section_mem_map;
1814 struct mem_section_usage *usage;
1815 #ifdef CONFIG_PAGE_EXTENSION
1817 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use
1818 * section. (see page_ext.h about this.)
1820 struct page_ext *page_ext;
1824 * WARNING: mem_section must be a power-of-2 in size for the
1825 * calculation and use of SECTION_ROOT_MASK to make sense.
1829 #ifdef CONFIG_SPARSEMEM_EXTREME
1830 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
1832 #define SECTIONS_PER_ROOT 1
1835 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
1836 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT)
1837 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
1839 #ifdef CONFIG_SPARSEMEM_EXTREME
1840 extern struct mem_section **mem_section;
1842 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
1845 static inline unsigned long *section_to_usemap(struct mem_section *ms)
1847 return ms->usage->pageblock_flags;
1850 static inline struct mem_section *__nr_to_section(unsigned long nr)
1852 unsigned long root = SECTION_NR_TO_ROOT(nr);
1854 if (unlikely(root >= NR_SECTION_ROOTS))
1857 #ifdef CONFIG_SPARSEMEM_EXTREME
1858 if (!mem_section || !mem_section[root])
1861 return &mem_section[root][nr & SECTION_ROOT_MASK];
1863 extern size_t mem_section_usage_size(void);
1866 * We use the lower bits of the mem_map pointer to store
1867 * a little bit of information. The pointer is calculated
1868 * as mem_map - section_nr_to_pfn(pnum). The result is
1869 * aligned to the minimum alignment of the two values:
1870 * 1. All mem_map arrays are page-aligned.
1871 * 2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT
1872 * lowest bits. PFN_SECTION_SHIFT is arch-specific
1873 * (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the
1874 * worst combination is powerpc with 256k pages,
1875 * which results in PFN_SECTION_SHIFT equal 6.
1876 * To sum it up, at least 6 bits are available on all architectures.
1877 * However, we can exceed 6 bits on some other architectures except
1878 * powerpc (e.g. 15 bits are available on x86_64, 13 bits are available
1879 * with the worst case of 64K pages on arm64) if we make sure the
1880 * exceeded bit is not applicable to powerpc.
1883 SECTION_MARKED_PRESENT_BIT,
1884 SECTION_HAS_MEM_MAP_BIT,
1885 SECTION_IS_ONLINE_BIT,
1886 SECTION_IS_EARLY_BIT,
1887 #ifdef CONFIG_ZONE_DEVICE
1888 SECTION_TAINT_ZONE_DEVICE_BIT,
1890 SECTION_MAP_LAST_BIT,
1893 #define SECTION_MARKED_PRESENT BIT(SECTION_MARKED_PRESENT_BIT)
1894 #define SECTION_HAS_MEM_MAP BIT(SECTION_HAS_MEM_MAP_BIT)
1895 #define SECTION_IS_ONLINE BIT(SECTION_IS_ONLINE_BIT)
1896 #define SECTION_IS_EARLY BIT(SECTION_IS_EARLY_BIT)
1897 #ifdef CONFIG_ZONE_DEVICE
1898 #define SECTION_TAINT_ZONE_DEVICE BIT(SECTION_TAINT_ZONE_DEVICE_BIT)
1900 #define SECTION_MAP_MASK (~(BIT(SECTION_MAP_LAST_BIT) - 1))
1901 #define SECTION_NID_SHIFT SECTION_MAP_LAST_BIT
1903 static inline struct page *__section_mem_map_addr(struct mem_section *section)
1905 unsigned long map = section->section_mem_map;
1906 map &= SECTION_MAP_MASK;
1907 return (struct page *)map;
1910 static inline int present_section(struct mem_section *section)
1912 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
1915 static inline int present_section_nr(unsigned long nr)
1917 return present_section(__nr_to_section(nr));
1920 static inline int valid_section(struct mem_section *section)
1922 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
1925 static inline int early_section(struct mem_section *section)
1927 return (section && (section->section_mem_map & SECTION_IS_EARLY));
1930 static inline int valid_section_nr(unsigned long nr)
1932 return valid_section(__nr_to_section(nr));
1935 static inline int online_section(struct mem_section *section)
1937 return (section && (section->section_mem_map & SECTION_IS_ONLINE));
1940 #ifdef CONFIG_ZONE_DEVICE
1941 static inline int online_device_section(struct mem_section *section)
1943 unsigned long flags = SECTION_IS_ONLINE | SECTION_TAINT_ZONE_DEVICE;
1945 return section && ((section->section_mem_map & flags) == flags);
1948 static inline int online_device_section(struct mem_section *section)
1954 static inline int online_section_nr(unsigned long nr)
1956 return online_section(__nr_to_section(nr));
1959 #ifdef CONFIG_MEMORY_HOTPLUG
1960 void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
1961 void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
1964 static inline struct mem_section *__pfn_to_section(unsigned long pfn)
1966 return __nr_to_section(pfn_to_section_nr(pfn));
1969 extern unsigned long __highest_present_section_nr;
1971 static inline int subsection_map_index(unsigned long pfn)
1973 return (pfn & ~(PAGE_SECTION_MASK)) / PAGES_PER_SUBSECTION;
1976 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1977 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
1979 int idx = subsection_map_index(pfn);
1981 return test_bit(idx, READ_ONCE(ms->usage)->subsection_map);
1984 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
1990 #ifndef CONFIG_HAVE_ARCH_PFN_VALID
1992 * pfn_valid - check if there is a valid memory map entry for a PFN
1993 * @pfn: the page frame number to check
1995 * Check if there is a valid memory map entry aka struct page for the @pfn.
1996 * Note, that availability of the memory map entry does not imply that
1997 * there is actual usable memory at that @pfn. The struct page may
1998 * represent a hole or an unusable page frame.
2000 * Return: 1 for PFNs that have memory map entries and 0 otherwise
2002 static inline int pfn_valid(unsigned long pfn)
2004 struct mem_section *ms;
2008 * Ensure the upper PAGE_SHIFT bits are clear in the
2009 * pfn. Else it might lead to false positives when
2010 * some of the upper bits are set, but the lower bits
2011 * match a valid pfn.
2013 if (PHYS_PFN(PFN_PHYS(pfn)) != pfn)
2016 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
2018 ms = __pfn_to_section(pfn);
2019 rcu_read_lock_sched();
2020 if (!valid_section(ms)) {
2021 rcu_read_unlock_sched();
2025 * Traditionally early sections always returned pfn_valid() for
2026 * the entire section-sized span.
2028 ret = early_section(ms) || pfn_section_valid(ms, pfn);
2029 rcu_read_unlock_sched();
2035 static inline int pfn_in_present_section(unsigned long pfn)
2037 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
2039 return present_section(__pfn_to_section(pfn));
2042 static inline unsigned long next_present_section_nr(unsigned long section_nr)
2044 while (++section_nr <= __highest_present_section_nr) {
2045 if (present_section_nr(section_nr))
2053 * These are _only_ used during initialisation, therefore they
2054 * can use __initdata ... They could have names to indicate
2058 #define pfn_to_nid(pfn) \
2060 unsigned long __pfn_to_nid_pfn = (pfn); \
2061 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
2064 #define pfn_to_nid(pfn) (0)
2067 void sparse_init(void);
2069 #define sparse_init() do {} while (0)
2070 #define sparse_index_init(_sec, _nid) do {} while (0)
2071 #define pfn_in_present_section pfn_valid
2072 #define subsection_map_init(_pfn, _nr_pages) do {} while (0)
2073 #endif /* CONFIG_SPARSEMEM */
2075 #endif /* !__GENERATING_BOUNDS.H */
2076 #endif /* !__ASSEMBLY__ */
2077 #endif /* _LINUX_MMZONE_H */