summaryrefslogtreecommitdiff
path: root/include/linux/mmzone.h
blob: 310b6e7ce58aa30ee43deb98eca108c738135fc0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_MMZONE_H
#define _LINUX_MMZONE_H

#ifndef __ASSEMBLY__
#ifndef __GENERATING_BOUNDS_H

#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/bitops.h>
#include <linux/cache.h>
#include <linux/threads.h>
#include <linux/numa.h>
#include <linux/init.h>
#include <linux/seqlock.h>
#include <linux/nodemask.h>
#include <linux/pageblock-flags.h>
#include <linux/page-flags-layout.h>
#include <linux/atomic.h>
#include <linux/mm_types.h>
#include <linux/page-flags.h>
#include <linux/local_lock.h>
#include <asm/page.h>

/* Free memory management - zoned buddy allocator.  */
#ifndef CONFIG_FORCE_MAX_ZONEORDER
#define MAX_ORDER 11
#else
#define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
#endif
#define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))

/*
 * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
 * costly to service.  That is between allocation orders which should
 * coalesce naturally under reasonable reclaim pressure and those which
 * will not.
 */
#define PAGE_ALLOC_COSTLY_ORDER 3

enum migratetype {
	MIGRATE_UNMOVABLE,
	MIGRATE_MOVABLE,
	MIGRATE_RECLAIMABLE,
	MIGRATE_PCPTYPES,	/* the number of types on the pcp lists */
	MIGRATE_HIGHATOMIC = MIGRATE_PCPTYPES,
#ifdef CONFIG_CMA
	/*
	 * MIGRATE_CMA migration type is designed to mimic the way
	 * ZONE_MOVABLE works.  Only movable pages can be allocated
	 * from MIGRATE_CMA pageblocks and page allocator never
	 * implicitly change migration type of MIGRATE_CMA pageblock.
	 *
	 * The way to use it is to change migratetype of a range of
	 * pageblocks to MIGRATE_CMA which can be done by
	 * __free_pageblock_cma() function.  What is important though
	 * is that a range of pageblocks must be aligned to
	 * MAX_ORDER_NR_PAGES should biggest page be bigger than
	 * a single pageblock.
	 */
	MIGRATE_CMA,
#endif
#ifdef CONFIG_MEMORY_ISOLATION
	MIGRATE_ISOLATE,	/* can't allocate from here */
#endif
	MIGRATE_TYPES
};

/* In mm/page_alloc.c; keep in sync also with show_migration_types() there */
extern const char * const migratetype_names[MIGRATE_TYPES];

#ifdef CONFIG_CMA
#  define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
#  define is_migrate_cma_page(_page) (get_pageblock_migratetype(_page) == MIGRATE_CMA)
#else
#  define is_migrate_cma(migratetype) false
#  define is_migrate_cma_page(_page) false
#endif

static inline bool is_migrate_movable(int mt)
{
	return is_migrate_cma(mt) || mt == MIGRATE_MOVABLE;
}

/*
 * Check whether a migratetype can be merged with another migratetype.
 *
 * It is only mergeable when it can fall back to other migratetypes for
 * allocation. See fallbacks[MIGRATE_TYPES][3] in page_alloc.c.
 */
static inline bool migratetype_is_mergeable(int mt)
{
	return mt < MIGRATE_PCPTYPES;
}

#define for_each_migratetype_order(order, type) \
	for (order = 0; order < MAX_ORDER; order++) \
		for (type = 0; type < MIGRATE_TYPES; type++)

extern int page_group_by_mobility_disabled;

#define MIGRATETYPE_MASK ((1UL << PB_migratetype_bits) - 1)

#define get_pageblock_migratetype(page)					\
	get_pfnblock_flags_mask(page, page_to_pfn(page), MIGRATETYPE_MASK)

struct free_area {
	struct list_head	free_list[MIGRATE_TYPES];
	unsigned long		nr_free;
};

static inline struct page *get_page_from_free_area(struct free_area *area,
					    int migratetype)
{
	return list_first_entry_or_null(&area->free_list[migratetype],
					struct page, lru);
}

static inline bool free_area_empty(struct free_area *area, int migratetype)
{
	return list_empty(&area->free_list[migratetype]);
}

struct pglist_data;

/*
 * Add a wild amount of padding here to ensure data fall into separate
 * cachelines.  There are very few zone structures in the machine, so space
 * consumption is not a concern here.
 */
#if defined(CONFIG_SMP)
struct zone_padding {
	char x[0];
} ____cacheline_internodealigned_in_smp;
#define ZONE_PADDING(name)	struct zone_padding name;
#else
#define ZONE_PADDING(name)
#endif

#ifdef CONFIG_NUMA
enum numa_stat_item {
	NUMA_HIT,		/* allocated in intended node */
	NUMA_MISS,		/* allocated in non intended node */
	NUMA_FOREIGN,		/* was intended here, hit elsewhere */
	NUMA_INTERLEAVE_HIT,	/* interleaver preferred this zone */
	NUMA_LOCAL,		/* allocation from local node */
	NUMA_OTHER,		/* allocation from other node */
	NR_VM_NUMA_EVENT_ITEMS
};
#else
#define NR_VM_NUMA_EVENT_ITEMS 0
#endif

enum zone_stat_item {
	/* First 128 byte cacheline (assuming 64 bit words) */
	NR_FREE_PAGES,
	NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */
	NR_ZONE_INACTIVE_ANON = NR_ZONE_LRU_BASE,
	NR_ZONE_ACTIVE_ANON,
	NR_ZONE_INACTIVE_FILE,
	NR_ZONE_ACTIVE_FILE,
	NR_ZONE_UNEVICTABLE,
	NR_ZONE_WRITE_PENDING,	/* Count of dirty, writeback and unstable pages */
	NR_MLOCK,		/* mlock()ed pages found and moved off LRU */
	/* Second 128 byte cacheline */
	NR_BOUNCE,
#if IS_ENABLED(CONFIG_ZSMALLOC)
	NR_ZSPAGES,		/* allocated in zsmalloc */
#endif
	NR_FREE_CMA_PAGES,
	NR_VM_ZONE_STAT_ITEMS };

enum node_stat_item {
	NR_LRU_BASE,
	NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
	NR_ACTIVE_ANON,		/*  "     "     "   "       "         */
	NR_INACTIVE_FILE,	/*  "     "     "   "       "         */
	NR_ACTIVE_FILE,		/*  "     "     "   "       "         */
	NR_UNEVICTABLE,		/*  "     "     "   "       "         */
	NR_SLAB_RECLAIMABLE_B,
	NR_SLAB_UNRECLAIMABLE_B,
	NR_ISOLATED_ANON,	/* Temporary isolated pages from anon lru */
	NR_ISOLATED_FILE,	/* Temporary isolated pages from file lru */
	WORKINGSET_NODES,
	WORKINGSET_REFAULT_BASE,
	WORKINGSET_REFAULT_ANON = WORKINGSET_REFAULT_BASE,
	WORKINGSET_REFAULT_FILE,
	WORKINGSET_ACTIVATE_BASE,
	WORKINGSET_ACTIVATE_ANON = WORKINGSET_ACTIVATE_BASE,
	WORKINGSET_ACTIVATE_FILE,
	WORKINGSET_RESTORE_BASE,
	WORKINGSET_RESTORE_ANON = WORKINGSET_RESTORE_BASE,
	WORKINGSET_RESTORE_FILE,
	WORKINGSET_NODERECLAIM,
	NR_ANON_MAPPED,	/* Mapped anonymous pages */
	NR_FILE_MAPPED,	/* pagecache pages mapped into pagetables.
			   only modified from process context */
	NR_FILE_PAGES,
	NR_FILE_DIRTY,
	NR_WRITEBACK,
	NR_WRITEBACK_TEMP,	/* Writeback using temporary buffers */
	NR_SHMEM,		/* shmem pages (included tmpfs/GEM pages) */
	NR_SHMEM_THPS,
	NR_SHMEM_PMDMAPPED,
	NR_FILE_THPS,
	NR_FILE_PMDMAPPED,
	NR_ANON_THPS,
	NR_VMSCAN_WRITE,
	NR_VMSCAN_IMMEDIATE,	/* Prioritise for reclaim when writeback ends */
	NR_DIRTIED,		/* page dirtyings since bootup */
	NR_WRITTEN,		/* page writings since bootup */
	NR_THROTTLED_WRITTEN,	/* NR_WRITTEN while reclaim throttled */
	NR_KERNEL_MISC_RECLAIMABLE,	/* reclaimable non-slab kernel pages */
	NR_FOLL_PIN_ACQUIRED,	/* via: pin_user_page(), gup flag: FOLL_PIN */
	NR_FOLL_PIN_RELEASED,	/* pages returned via unpin_user_page() */
	NR_KERNEL_STACK_KB,	/* measured in KiB */
#if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
	NR_KERNEL_SCS_KB,	/* measured in KiB */
#endif
	NR_PAGETABLE,		/* used for pagetables */
#ifdef CONFIG_SWAP
	NR_SWAPCACHE,
#endif
#ifdef CONFIG_NUMA_BALANCING
	PGPROMOTE_SUCCESS,	/* promote successfully */
#endif
	NR_VM_NODE_STAT_ITEMS
};

/*
 * Returns true if the item should be printed in THPs (/proc/vmstat
 * currently prints number of anon, file and shmem THPs. But the item
 * is charged in pages).
 */
static __always_inline bool vmstat_item_print_in_thp(enum node_stat_item item)
{
	if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
		return false;

	return item == NR_ANON_THPS ||
	       item == NR_FILE_THPS ||
	       item == NR_SHMEM_THPS ||
	       item == NR_SHMEM_PMDMAPPED ||
	       item == NR_FILE_PMDMAPPED;
}

/*
 * Returns true if the value is measured in bytes (most vmstat values are
 * measured in pages). This defines the API part, the internal representation
 * might be different.
 */
static __always_inline bool vmstat_item_in_bytes(int idx)
{
	/*
	 * Global and per-node slab counters track slab pages.
	 * It's expected that changes are multiples of PAGE_SIZE.
	 * Internally values are stored in pages.
	 *
	 * Per-memcg and per-lruvec counters track memory, consumed
	 * by individual slab objects. These counters are actually
	 * byte-precise.
	 */
	return (idx == NR_SLAB_RECLAIMABLE_B ||
		idx == NR_SLAB_UNRECLAIMABLE_B);
}

/*
 * We do arithmetic on the LRU lists in various places in the code,
 * so it is important to keep the active lists LRU_ACTIVE higher in
 * the array than the corresponding inactive lists, and to keep
 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
 *
 * This has to be kept in sync with the statistics in zone_stat_item
 * above and the descriptions in vmstat_text in mm/vmstat.c
 */
#define LRU_BASE 0
#define LRU_ACTIVE 1
#define LRU_FILE 2

enum lru_list {
	LRU_INACTIVE_ANON = LRU_BASE,
	LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
	LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
	LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
	LRU_UNEVICTABLE,
	NR_LRU_LISTS
};

enum vmscan_throttle_state {
	VMSCAN_THROTTLE_WRITEBACK,
	VMSCAN_THROTTLE_ISOLATED,
	VMSCAN_THROTTLE_NOPROGRESS,
	VMSCAN_THROTTLE_CONGESTED,
	NR_VMSCAN_THROTTLE,
};

#define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++)

#define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++)

static inline bool is_file_lru(enum lru_list lru)
{
	return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE);
}

static inline bool is_active_lru(enum lru_list lru)
{
	return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE);
}

#define ANON_AND_FILE 2

enum lruvec_flags {
	LRUVEC_CONGESTED,		/* lruvec has many dirty pages
					 * backed by a congested BDI
					 */
};

struct lruvec {
	struct list_head		lists[NR_LRU_LISTS];
	/* per lruvec lru_lock for memcg */
	spinlock_t			lru_lock;
	/*
	 * These track the cost of reclaiming one LRU - file or anon -
	 * over the other. As the observed cost of reclaiming one LRU
	 * increases, the reclaim scan balance tips toward the other.
	 */
	unsigned long			anon_cost;
	unsigned long			file_cost;
	/* Non-resident age, driven by LRU movement */
	atomic_long_t			nonresident_age;
	/* Refaults at the time of last reclaim cycle */
	unsigned long			refaults[ANON_AND_FILE];
	/* Various lruvec state flags (enum lruvec_flags) */
	unsigned long			flags;
#ifdef CONFIG_MEMCG
	struct pglist_data *pgdat;
#endif
};

/* Isolate unmapped pages */
#define ISOLATE_UNMAPPED	((__force isolate_mode_t)0x2)
/* Isolate for asynchronous migration */
#define ISOLATE_ASYNC_MIGRATE	((__force isolate_mode_t)0x4)
/* Isolate unevictable pages */
#define ISOLATE_UNEVICTABLE	((__force isolate_mode_t)0x8)

/* LRU Isolation modes. */
typedef unsigned __bitwise isolate_mode_t;

enum zone_watermarks {
	WMARK_MIN,
	WMARK_LOW,
	WMARK_HIGH,
	NR_WMARK
};

/*
 * One per migratetype for each PAGE_ALLOC_COSTLY_ORDER plus one additional
 * for pageblock size for THP if configured.
 */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define NR_PCP_THP 1
#else
#define NR_PCP_THP 0
#endif
#define NR_PCP_LISTS (MIGRATE_PCPTYPES * (PAGE_ALLOC_COSTLY_ORDER + 1 + NR_PCP_THP))

/*
 * Shift to encode migratetype and order in the same integer, with order
 * in the least significant bits.
 */
#define NR_PCP_ORDER_WIDTH 8
#define NR_PCP_ORDER_MASK ((1<<NR_PCP_ORDER_WIDTH) - 1)

#define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost)
#define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost)
#define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost)
#define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost)

/* Fields and list protected by pagesets local_lock in page_alloc.c */
struct per_cpu_pages {
	int count;		/* number of pages in the list */
	int high;		/* high watermark, emptying needed */
	int batch;		/* chunk size for buddy add/remove */
	short free_factor;	/* batch scaling factor during free */
#ifdef CONFIG_NUMA
	short expire;		/* When 0, remote pagesets are drained */
#endif

	/* Lists of pages, one per migrate type stored on the pcp-lists */
	struct list_head lists[NR_PCP_LISTS];
};

struct per_cpu_zonestat {
#ifdef CONFIG_SMP
	s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
	s8 stat_threshold;
#endif
#ifdef CONFIG_NUMA
	/*
	 * Low priority inaccurate counters that are only folded
	 * on demand. Use a large type to avoid the overhead of
	 * folding during refresh_cpu_vm_stats.
	 */
	unsigned long vm_numa_event[NR_VM_NUMA_EVENT_ITEMS];
#endif
};

struct per_cpu_nodestat {
	s8 stat_threshold;
	s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS];
};

#endif /* !__GENERATING_BOUNDS.H */

enum zone_type {
	/*
	 * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able
	 * to DMA to all of the addressable memory (ZONE_NORMAL).
	 * On architectures where this area covers the whole 32 bit address
	 * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller
	 * DMA addressing constraints. This distinction is important as a 32bit
	 * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit
	 * platforms may need both zones as they support peripherals with
	 * different DMA addressing limitations.
	 */
#ifdef CONFIG_ZONE_DMA
	ZONE_DMA,
#endif
#ifdef CONFIG_ZONE_DMA32
	ZONE_DMA32,
#endif
	/*
	 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
	 * performed on pages in ZONE_NORMAL if the DMA devices support
	 * transfers to all addressable memory.
	 */
	ZONE_NORMAL,
#ifdef CONFIG_HIGHMEM
	/*
	 * A memory area that is only addressable by the kernel through
	 * mapping portions into its own address space. This is for example
	 * used by i386 to allow the kernel to address the memory beyond
	 * 900MB. The kernel will set up special mappings (page
	 * table entries on i386) for each page that the kernel needs to
	 * access.
	 */
	ZONE_HIGHMEM,
#endif
	/*
	 * ZONE_MOVABLE is similar to ZONE_NORMAL, except that it contains
	 * movable pages with few exceptional cases described below. Main use
	 * cases for ZONE_MOVABLE are to make memory offlining/unplug more
	 * likely to succeed, and to locally limit unmovable allocations - e.g.,
	 * to increase the number of THP/huge pages. Notable special cases are:
	 *
	 * 1. Pinned pages: (long-term) pinning of movable pages might
	 *    essentially turn such pages unmovable. Therefore, we do not allow
	 *    pinning long-term pages in ZONE_MOVABLE. When pages are pinned and
	 *    faulted, they come from the right zone right away. However, it is
	 *    still possible that address space already has pages in
	 *    ZONE_MOVABLE at the time when pages are pinned (i.e. user has
	 *    touches that memory before pinning). In such case we migrate them
	 *    to a different zone. When migration fails - pinning fails.
	 * 2. memblock allocations: kernelcore/movablecore setups might create
	 *    situations where ZONE_MOVABLE contains unmovable allocations
	 *    after boot. Memory offlining and allocations fail early.
	 * 3. Memory holes: kernelcore/movablecore setups might create very rare
	 *    situations where ZONE_MOVABLE contains memory holes after boot,
	 *    for example, if we have sections that are only partially
	 *    populated. Memory offlining and allocations fail early.
	 * 4. PG_hwpoison pages: while poisoned pages can be skipped during
	 *    memory offlining, such pages cannot be allocated.
	 * 5. Unmovable PG_offline pages: in paravirtualized environments,
	 *    hotplugged memory blocks might only partially be managed by the
	 *    buddy (e.g., via XEN-balloon, Hyper-V balloon, virtio-mem). The
	 *    parts not manged by the buddy are unmovable PG_offline pages. In
	 *    some cases (virtio-mem), such pages can be skipped during
	 *    memory offlining, however, cannot be moved/allocated. These
	 *    techniques might use alloc_contig_range() to hide previously
	 *    exposed pages from the buddy again (e.g., to implement some sort
	 *    of memory unplug in virtio-mem).
	 * 6. ZERO_PAGE(0), kernelcore/movablecore setups might create
	 *    situations where ZERO_PAGE(0) which is allocated differently
	 *    on different platforms may end up in a movable zone. ZERO_PAGE(0)
	 *    cannot be migrated.
	 * 7. Memory-hotplug: when using memmap_on_memory and onlining the
	 *    memory to the MOVABLE zone, the vmemmap pages are also placed in
	 *    such zone. Such pages cannot be really moved around as they are
	 *    self-stored in the range, but they are treated as movable when
	 *    the range they describe is about to be offlined.
	 *
	 * In general, no unmovable allocations that degrade memory offlining
	 * should end up in ZONE_MOVABLE. Allocators (like alloc_contig_range())
	 * have to expect that migrating pages in ZONE_MOVABLE can fail (even
	 * if has_unmovable_pages() states that there are no unmovable pages,
	 * there can be false negatives).
	 */
	ZONE_MOVABLE,
#ifdef CONFIG_ZONE_DEVICE
	ZONE_DEVICE,
#endif
	__MAX_NR_ZONES

};

#ifndef __GENERATING_BOUNDS_H

#define ASYNC_AND_SYNC 2

struct zone {
	/* Read-mostly fields */

	/* zone watermarks, access with *_wmark_pages(zone) macros */
	unsigned long _watermark[NR_WMARK];
	unsigned long watermark_boost;

	unsigned long nr_reserved_highatomic;

	/*
	 * We don't know if the memory that we're going to allocate will be
	 * freeable or/and it will be released eventually, so to avoid totally
	 * wasting several GB of ram we must reserve some of the lower zone
	 * memory (otherwise we risk to run OOM on the lower zones despite
	 * there being tons of freeable ram on the higher zones).  This array is
	 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl
	 * changes.
	 */
	long lowmem_reserve[MAX_NR_ZONES];

#ifdef CONFIG_NUMA
	int node;
#endif
	struct pglist_data	*zone_pgdat;
	struct per_cpu_pages	__percpu *per_cpu_pageset;
	struct per_cpu_zonestat	__percpu *per_cpu_zonestats;
	/*
	 * the high and batch values are copied to individual pagesets for
	 * faster access
	 */
	int pageset_high;
	int pageset_batch;

#ifndef CONFIG_SPARSEMEM
	/*
	 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
	 * In SPARSEMEM, this map is stored in struct mem_section
	 */
	unsigned long		*pageblock_flags;
#endif /* CONFIG_SPARSEMEM */

	/* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
	unsigned long		zone_start_pfn;

	/*
	 * spanned_pages is the total pages spanned by the zone, including
	 * holes, which is calculated as:
	 * 	spanned_pages = zone_end_pfn - zone_start_pfn;
	 *
	 * present_pages is physical pages existing within the zone, which
	 * is calculated as:
	 *	present_pages = spanned_pages - absent_pages(pages in holes);
	 *
	 * present_early_pages is present pages existing within the zone
	 * located on memory available since early boot, excluding hotplugged
	 * memory.
	 *
	 * managed_pages is present pages managed by the buddy system, which
	 * is calculated as (reserved_pages includes pages allocated by the
	 * bootmem allocator):
	 *	managed_pages = present_pages - reserved_pages;
	 *
	 * cma pages is present pages that are assigned for CMA use
	 * (MIGRATE_CMA).
	 *
	 * So present_pages may be used by memory hotplug or memory power
	 * management logic to figure out unmanaged pages by checking
	 * (present_pages - managed_pages). And managed_pages should be used
	 * by page allocator and vm scanner to calculate all kinds of watermarks
	 * and thresholds.
	 *
	 * Locking rules:
	 *
	 * zone_start_pfn and spanned_pages are protected by span_seqlock.
	 * It is a seqlock because it has to be read outside of zone->lock,
	 * and it is done in the main allocator path.  But, it is written
	 * quite infrequently.
	 *
	 * The span_seq lock is declared along with zone->lock because it is
	 * frequently read in proximity to zone->lock.  It's good to
	 * give them a chance of being in the same cacheline.
	 *
	 * Write access to present_pages at runtime should be protected by
	 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of
	 * present_pages should get_online_mems() to get a stable value.
	 */
	atomic_long_t		managed_pages;
	unsigned long		spanned_pages;
	unsigned long		present_pages;
#if defined(CONFIG_MEMORY_HOTPLUG)
	unsigned long		present_early_pages;
#endif
#ifdef CONFIG_CMA
	unsigned long		cma_pages;
#endif

	const char		*name;

#ifdef CONFIG_MEMORY_ISOLATION
	/*
	 * Number of isolated pageblock. It is used to solve incorrect
	 * freepage counting problem due to racy retrieving migratetype
	 * of pageblock. Protected by zone->lock.
	 */
	unsigned long		nr_isolate_pageblock;
#endif

#ifdef CONFIG_MEMORY_HOTPLUG
	/* see spanned/present_pages for more description */
	seqlock_t		span_seqlock;
#endif

	int initialized;

	/* Write-intensive fields used from the page allocator */
	ZONE_PADDING(_pad1_)

	/* free areas of different sizes */
	struct free_area	free_area[MAX_ORDER];

	/* zone flags, see below */
	unsigned long		flags;

	/* Primarily protects free_area */
	spinlock_t		lock;

	/* Write-intensive fields used by compaction and vmstats. */
	ZONE_PADDING(_pad2_)

	/*
	 * When free pages are below this point, additional steps are taken
	 * when reading the number of free pages to avoid per-cpu counter
	 * drift allowing watermarks to be breached
	 */
	unsigned long percpu_drift_mark;

#if defined CONFIG_COMPACTION || defined CONFIG_CMA
	/* pfn where compaction free scanner should start */
	unsigned long		compact_cached_free_pfn;
	/* pfn where compaction migration scanner should start */
	unsigned long		compact_cached_migrate_pfn[ASYNC_AND_SYNC];
	unsigned long		compact_init_migrate_pfn;
	unsigned long		compact_init_free_pfn;
#endif

#ifdef CONFIG_COMPACTION
	/*
	 * On compaction failure, 1<<compact_defer_shift compactions
	 * are skipped before trying again. The number attempted since
	 * last failure is tracked with compact_considered.
	 * compact_order_failed is the minimum compaction failed order.
	 */
	unsigned int		compact_considered;
	unsigned int		compact_defer_shift;
	int			compact_order_failed;
#endif

#if defined CONFIG_COMPACTION || defined CONFIG_CMA
	/* Set to true when the PG_migrate_skip bits should be cleared */
	bool			compact_blockskip_flush;
#endif

	bool			contiguous;

	ZONE_PADDING(_pad3_)
	/* Zone statistics */
	atomic_long_t		vm_stat[NR_VM_ZONE_STAT_ITEMS];
	atomic_long_t		vm_numa_event[NR_VM_NUMA_EVENT_ITEMS];
} ____cacheline_internodealigned_in_smp;

enum pgdat_flags {
	PGDAT_DIRTY,			/* reclaim scanning has recently found
					 * many dirty file pages at the tail
					 * of the LRU.
					 */
	PGDAT_WRITEBACK,		/* reclaim scanning has recently found
					 * many pages under writeback
					 */
	PGDAT_RECLAIM_LOCKED,		/* prevents concurrent reclaim */
};

enum zone_flags {
	ZONE_BOOSTED_WATERMARK,		/* zone recently boosted watermarks.
					 * Cleared when kswapd is woken.
					 */
	ZONE_RECLAIM_ACTIVE,		/* kswapd may be scanning the zone. */
};

static inline unsigned long zone_managed_pages(struct zone *zone)
{
	return (unsigned long)atomic_long_read(&zone->managed_pages);
}

static inline unsigned long zone_cma_pages(struct zone *zone)
{
#ifdef CONFIG_CMA
	return zone->cma_pages;
#else
	return 0;
#endif
}

static inline unsigned long zone_end_pfn(const struct zone *zone)
{
	return zone->zone_start_pfn + zone->spanned_pages;
}

static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)
{
	return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone);
}

static inline bool zone_is_initialized(struct zone *zone)
{
	return zone->initialized;
}

static inline bool zone_is_empty(struct zone *zone)
{
	return zone->spanned_pages == 0;
}

/*
 * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty
 * intersection with the given zone
 */
static inline bool zone_intersects(struct zone *zone,
		unsigned long start_pfn, unsigned long nr_pages)
{
	if (zone_is_empty(zone))
		return false;
	if (start_pfn >= zone_end_pfn(zone) ||
	    start_pfn + nr_pages <= zone->zone_start_pfn)
		return false;

	return true;
}

/*
 * The "priority" of VM scanning is how much of the queues we will scan in one
 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
 * queues ("queue_length >> 12") during an aging round.
 */
#define DEF_PRIORITY 12

/* Maximum number of zones on a zonelist */
#define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)

enum {
	ZONELIST_FALLBACK,	/* zonelist with fallback */
#ifdef CONFIG_NUMA
	/*
	 * The NUMA zonelists are doubled because we need zonelists that
	 * restrict the allocations to a single node for __GFP_THISNODE.
	 */
	ZONELIST_NOFALLBACK,	/* zonelist without fallback (__GFP_THISNODE) */
#endif
	MAX_ZONELISTS
};

/*
 * This struct contains information about a zone in a zonelist. It is stored
 * here to avoid dereferences into large structures and lookups of tables
 */
struct zoneref {
	struct zone *zone;	/* Pointer to actual zone */
	int zone_idx;		/* zone_idx(zoneref->zone) */
};

/*
 * One allocation request operates on a zonelist. A zonelist
 * is a list of zones, the first one is the 'goal' of the
 * allocation, the other zones are fallback zones, in decreasing
 * priority.
 *
 * To speed the reading of the zonelist, the zonerefs contain the zone index
 * of the entry being read. Helper functions to access information given
 * a struct zoneref are
 *
 * zonelist_zone()	- Return the struct zone * for an entry in _zonerefs
 * zonelist_zone_idx()	- Return the index of the zone for an entry
 * zonelist_node_idx()	- Return the index of the node for an entry
 */
struct zonelist {
	struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
};

/*
 * The array of struct pages for flatmem.
 * It must be declared for SPARSEMEM as well because there are configurations
 * that rely on that.
 */
extern struct page *mem_map;

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
struct deferred_split {
	spinlock_t split_queue_lock;
	struct list_head split_queue;
	unsigned long split_queue_len;
};
#endif

/*
 * On NUMA machines, each NUMA node would have a pg_data_t to describe
 * it's memory layout. On UMA machines there is a single pglist_data which
 * describes the whole memory.
 *
 * Memory statistics and page replacement data structures are maintained on a
 * per-zone basis.
 */
typedef struct pglist_data {
	/*
	 * node_zones contains just the zones for THIS node. Not all of the
	 * zones may be populated, but it is the full list. It is referenced by
	 * this node's node_zonelists as well as other node's node_zonelists.
	 */
	struct zone node_zones[MAX_NR_ZONES];

	/*
	 * node_zonelists contains references to all zones in all nodes.
	 * Generally the first zones will be references to this node's
	 * node_zones.
	 */
	struct zonelist node_zonelists[MAX_ZONELISTS];

	int nr_zones; /* number of populated zones in this node */
#ifdef CONFIG_FLATMEM	/* means !SPARSEMEM */
	struct page *node_mem_map;
#ifdef CONFIG_PAGE_EXTENSION
	struct page_ext *node_page_ext;
#endif
#endif
#if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
	/*
	 * Must be held any time you expect node_start_pfn,
	 * node_present_pages, node_spanned_pages or nr_zones to stay constant.
	 * Also synchronizes pgdat->first_deferred_pfn during deferred page
	 * init.
	 *
	 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to
	 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG
	 * or CONFIG_DEFERRED_STRUCT_PAGE_INIT.
	 *
	 * Nests above zone->lock and zone->span_seqlock
	 */
	spinlock_t node_size_lock;
#endif
	unsigned long node_start_pfn;
	unsigned long node_present_pages; /* total number of physical pages */
	unsigned long node_spanned_pages; /* total size of physical page
					     range, including holes */
	int node_id;
	wait_queue_head_t kswapd_wait;
	wait_queue_head_t pfmemalloc_wait;

	/* workqueues for throttling reclaim for different reasons. */
	wait_queue_head_t reclaim_wait[NR_VMSCAN_THROTTLE];

	atomic_t nr_writeback_throttled;/* nr of writeback-throttled tasks */
	unsigned long nr_reclaim_start;	/* nr pages written while throttled
					 * when throttling started. */
	struct task_struct *kswapd;	/* Protected by
					   mem_hotplug_begin/end() */
	int kswapd_order;
	enum zone_type kswapd_highest_zoneidx;

	int kswapd_failures;		/* Number of 'reclaimed == 0' runs */

#ifdef CONFIG_COMPACTION
	int kcompactd_max_order;
	enum zone_type kcompactd_highest_zoneidx;
	wait_queue_head_t kcompactd_wait;
	struct task_struct *kcompactd;
	bool proactive_compact_trigger;
#endif
	/*
	 * This is a per-node reserve of pages that are not available
	 * to userspace allocations.
	 */
	unsigned long		totalreserve_pages;

#ifdef CONFIG_NUMA
	/*
	 * node reclaim becomes active if more unmapped pages exist.
	 */
	unsigned long		min_unmapped_pages;
	unsigned long		min_slab_pages;
#endif /* CONFIG_NUMA */

	/* Write-intensive fields used by page reclaim */
	ZONE_PADDING(_pad1_)

#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
	/*
	 * If memory initialisation on large machines is deferred then this
	 * is the first PFN that needs to be initialised.
	 */
	unsigned long first_deferred_pfn;
#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
	struct deferred_split deferred_split_queue;
#endif

	/* Fields commonly accessed by the page reclaim scanner */

	/*
	 * NOTE: THIS IS UNUSED IF MEMCG IS ENABLED.
	 *
	 * Use mem_cgroup_lruvec() to look up lruvecs.
	 */
	struct lruvec		__lruvec;

	unsigned long		flags;

	ZONE_PADDING(_pad2_)

	/* Per-node vmstats */
	struct per_cpu_nodestat __percpu *per_cpu_nodestats;
	atomic_long_t		vm_stat[NR_VM_NODE_STAT_ITEMS];
} pg_data_t;

#define node_present_pages(nid)	(NODE_DATA(nid)->node_present_pages)
#define node_spanned_pages(nid)	(NODE_DATA(nid)->node_spanned_pages)

#define node_start_pfn(nid)	(NODE_DATA(nid)->node_start_pfn)
#define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))

static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat)
{
	return pgdat->node_start_pfn + pgdat->node_spanned_pages;
}

static inline bool pgdat_is_empty(pg_data_t *pgdat)
{
	return !pgdat->node_start_pfn && !pgdat->node_spanned_pages;
}

#include <linux/memory_hotplug.h>

void build_all_zonelists(pg_data_t *pgdat);
void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order,
		   enum zone_type highest_zoneidx);
bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
			 int highest_zoneidx, unsigned int alloc_flags,
			 long free_pages);
bool zone_watermark_ok(struct zone *z, unsigned int order,
		unsigned long mark, int highest_zoneidx,
		unsigned int alloc_flags);
bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
		unsigned long mark, int highest_zoneidx);
/*
 * Memory initialization context, use to differentiate memory added by
 * the platform statically or via memory hotplug interface.
 */
enum meminit_context {
	MEMINIT_EARLY,
	MEMINIT_HOTPLUG,
};

extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
				     unsigned long size);

extern void lruvec_init(struct lruvec *lruvec);

static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec)
{
#ifdef CONFIG_MEMCG
	return lruvec->pgdat;
#else
	return container_of(lruvec, struct pglist_data, __lruvec);
#endif
}

#ifdef CONFIG_HAVE_MEMORYLESS_NODES
int local_memory_node(int node_id);
#else
static inline int local_memory_node(int node_id) { return node_id; };
#endif

/*
 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
 */
#define zone_idx(zone)		((zone) - (zone)->zone_pgdat->node_zones)

#ifdef CONFIG_ZONE_DEVICE
static inline bool zone_is_zone_device(struct zone *zone)
{
	return zone_idx(zone) == ZONE_DEVICE;
}
#else
static inline bool zone_is_zone_device(struct zone *zone)
{
	return false;
}
#endif

/*
 * Returns true if a zone has pages managed by the buddy allocator.
 * All the reclaim decisions have to use this function rather than
 * populated_zone(). If the whole zone is reserved then we can easily
 * end up with populated_zone() && !managed_zone().
 */
static inline bool managed_zone(struct zone *zone)
{
	return zone_managed_pages(zone);
}

/* Returns true if a zone has memory */
static inline bool populated_zone(struct zone *zone)
{
	return zone->present_pages;
}

#ifdef CONFIG_NUMA
static inline int zone_to_nid(struct zone *zone)
{
	return zone->node;
}

static inline void zone_set_nid(struct zone *zone, int nid)
{
	zone->node = nid;
}
#else
static inline int zone_to_nid(struct zone *zone)
{
	return 0;
}

static inline void zone_set_nid(struct zone *zone, int nid) {}
#endif

extern int movable_zone;

static inline int is_highmem_idx(enum zone_type idx)
{
#ifdef CONFIG_HIGHMEM
	return (idx == ZONE_HIGHMEM ||
		(idx == ZONE_MOVABLE && movable_zone == ZONE_HIGHMEM));
#else
	return 0;
#endif
}

#ifdef CONFIG_ZONE_DMA
bool has_managed_dma(void);
#else
static inline bool has_managed_dma(void)
{
	return false;
}
#endif

/**
 * is_highmem - helper function to quickly check if a struct zone is a
 *              highmem zone or not.  This is an attempt to keep references
 *              to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
 * @zone: pointer to struct zone variable
 * Return: 1 for a highmem zone, 0 otherwise
 */
static inline int is_highmem(struct zone *zone)
{
#ifdef CONFIG_HIGHMEM
	return is_highmem_idx(zone_idx(zone));
#else
	return 0;
#endif
}

/* These two functions are used to setup the per zone pages min values */
struct ctl_table;

int min_free_kbytes_sysctl_handler(struct ctl_table *, int, void *, size_t *,
		loff_t *);
int watermark_scale_factor_sysctl_handler(struct ctl_table *, int, void *,
		size_t *, loff_t *);
extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES];
int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, void *,
		size_t *, loff_t *);
int percpu_pagelist_high_fraction_sysctl_handler(struct ctl_table *, int,
		void *, size_t *, loff_t *);
int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
		void *, size_t *, loff_t *);
int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
		void *, size_t *, loff_t *);
int numa_zonelist_order_handler(struct ctl_table *, int,
		void *, size_t *, loff_t *);
extern int percpu_pagelist_high_fraction;
extern char numa_zonelist_order[];
#define NUMA_ZONELIST_ORDER_LEN	16

#ifndef CONFIG_NUMA

extern struct pglist_data contig_page_data;
static inline struct pglist_data *NODE_DATA(int nid)
{
	return &contig_page_data;
}

#else /* CONFIG_NUMA */

#include <asm/mmzone.h>

#endif /* !CONFIG_NUMA */

extern struct pglist_data *first_online_pgdat(void);
extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
extern struct zone *next_zone(struct zone *zone);

/**
 * for_each_online_pgdat - helper macro to iterate over all online nodes
 * @pgdat: pointer to a pg_data_t variable
 */
#define for_each_online_pgdat(pgdat)			\
	for (pgdat = first_online_pgdat();		\
	     pgdat;					\
	     pgdat = next_online_pgdat(pgdat))
/**
 * for_each_zone - helper macro to iterate over all memory zones
 * @zone: pointer to struct zone variable
 *
 * The user only needs to declare the zone variable, for_each_zone
 * fills it in.
 */
#define for_each_zone(zone)			        \
	for (zone = (first_online_pgdat())->node_zones; \
	     zone;					\
	     zone = next_zone(zone))

#define for_each_populated_zone(zone)		        \
	for (zone = (first_online_pgdat())->node_zones; \
	     zone;					\
	     zone = next_zone(zone))			\
		if (!populated_zone(zone))		\
			; /* do nothing */		\
		else

static inline struct zone *zonelist_zone(struct zoneref *zoneref)
{
	return zoneref->zone;
}

static inline int zonelist_zone_idx(struct zoneref *zoneref)
{
	return zoneref->zone_idx;
}

static inline int zonelist_node_idx(struct zoneref *zoneref)
{
	return zone_to_nid(zoneref->zone);
}

struct zoneref *__next_zones_zonelist(struct zoneref *z,
					enum zone_type highest_zoneidx,
					nodemask_t *nodes);

/**
 * 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
 * @z: The cursor used as a starting point for the search
 * @highest_zoneidx: The zone index of the highest zone to return
 * @nodes: An optional nodemask to filter the zonelist with
 *
 * This function returns the next zone at or below a given zone index that is
 * within the allowed nodemask using a cursor as the starting point for the
 * search. The zoneref returned is a cursor that represents the current zone
 * being examined. It should be advanced by one before calling
 * next_zones_zonelist again.
 *
 * Return: the next zone at or below highest_zoneidx within the allowed
 * nodemask using a cursor within a zonelist as a starting point
 */
static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z,
					enum zone_type highest_zoneidx,
					nodemask_t *nodes)
{
	if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx))
		return z;
	return __next_zones_zonelist(z, highest_zoneidx, nodes);
}

/**
 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
 * @zonelist: The zonelist to search for a suitable zone
 * @highest_zoneidx: The zone index of the highest zone to return
 * @nodes: An optional nodemask to filter the zonelist with
 *
 * This function returns the first zone at or below a given zone index that is
 * within the allowed nodemask. The zoneref returned is a cursor that can be
 * used to iterate the zonelist with next_zones_zonelist by advancing it by
 * one before calling.
 *
 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is
 * never NULL). This may happen either genuinely, or due to concurrent nodemask
 * update due to cpuset modification.
 *
 * Return: Zoneref pointer for the first suitable zone found
 */
static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
					enum zone_type highest_zoneidx,
					nodemask_t *nodes)
{
	return next_zones_zonelist(zonelist->_zonerefs,
							highest_zoneidx, nodes);
}

/**
 * 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
 * @zone: The current zone in the iterator
 * @z: The current pointer within zonelist->_zonerefs being iterated
 * @zlist: The zonelist being iterated
 * @highidx: The zone index of the highest zone to return
 * @nodemask: Nodemask allowed by the allocator
 *
 * This iterator iterates though all zones at or below a given zone index and
 * within a given nodemask
 */
#define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
	for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z);	\
		zone;							\
		z = next_zones_zonelist(++z, highidx, nodemask),	\
			zone = zonelist_zone(z))

#define for_next_zone_zonelist_nodemask(zone, z, highidx, nodemask) \
	for (zone = z->zone;	\
		zone;							\
		z = next_zones_zonelist(++z, highidx, nodemask),	\
			zone = zonelist_zone(z))


/**
 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
 * @zone: The current zone in the iterator
 * @z: The current pointer within zonelist->zones being iterated
 * @zlist: The zonelist being iterated
 * @highidx: The zone index of the highest zone to return
 *
 * This iterator iterates though all zones at or below a given zone index.
 */
#define for_each_zone_zonelist(zone, z, zlist, highidx) \
	for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)

/* Whether the 'nodes' are all movable nodes */
static inline bool movable_only_nodes(nodemask_t *nodes)
{
	struct zonelist *zonelist;
	struct zoneref *z;
	int nid;

	if (nodes_empty(*nodes))
		return false;

	/*
	 * We can chose arbitrary node from the nodemask to get a
	 * zonelist as they are interlinked. We just need to find
	 * at least one zone that can satisfy kernel allocations.
	 */
	nid = first_node(*nodes);
	zonelist = &NODE_DATA(nid)->node_zonelists[ZONELIST_FALLBACK];
	z = first_zones_zonelist(zonelist, ZONE_NORMAL,	nodes);
	return (!z->zone) ? true : false;
}


#ifdef CONFIG_SPARSEMEM
#include <asm/sparsemem.h>
#endif

#ifdef CONFIG_FLATMEM
#define pfn_to_nid(pfn)		(0)
#endif

#ifdef CONFIG_SPARSEMEM

/*
 * PA_SECTION_SHIFT		physical address to/from section number
 * PFN_SECTION_SHIFT		pfn to/from section number
 */
#define PA_SECTION_SHIFT	(SECTION_SIZE_BITS)
#define PFN_SECTION_SHIFT	(SECTION_SIZE_BITS - PAGE_SHIFT)

#define NR_MEM_SECTIONS		(1UL << SECTIONS_SHIFT)

#define PAGES_PER_SECTION       (1UL << PFN_SECTION_SHIFT)
#define PAGE_SECTION_MASK	(~(PAGES_PER_SECTION-1))

#define SECTION_BLOCKFLAGS_BITS \
	((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)

#if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
#error Allocator MAX_ORDER exceeds SECTION_SIZE
#endif

static inline unsigned long pfn_to_section_nr(unsigned long pfn)
{
	return pfn >> PFN_SECTION_SHIFT;
}
static inline unsigned long section_nr_to_pfn(unsigned long sec)
{
	return sec << PFN_SECTION_SHIFT;
}

#define SECTION_ALIGN_UP(pfn)	(((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)
#define SECTION_ALIGN_DOWN(pfn)	((pfn) & PAGE_SECTION_MASK)

#define SUBSECTION_SHIFT 21
#define SUBSECTION_SIZE (1UL << SUBSECTION_SHIFT)

#define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT)
#define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT)
#define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1))

#if SUBSECTION_SHIFT > SECTION_SIZE_BITS
#error Subsection size exceeds section size
#else
#define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT))
#endif

#define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION)
#define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK)

struct mem_section_usage {
#ifdef CONFIG_SPARSEMEM_VMEMMAP
	DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION);
#endif
	/* See declaration of similar field in struct zone */
	unsigned long pageblock_flags[0];
};

void subsection_map_init(unsigned long pfn, unsigned long nr_pages);

struct page;
struct page_ext;
struct mem_section {
	/*
	 * This is, logically, a pointer to an array of struct
	 * pages.  However, it is stored with some other magic.
	 * (see sparse.c::sparse_init_one_section())
	 *
	 * Additionally during early boot we encode node id of
	 * the location of the section here to guide allocation.
	 * (see sparse.c::memory_present())
	 *
	 * Making it a UL at least makes someone do a cast
	 * before using it wrong.
	 */
	unsigned long section_mem_map;

	struct mem_section_usage *usage;
#ifdef CONFIG_PAGE_EXTENSION
	/*
	 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use
	 * section. (see page_ext.h about this.)
	 */
	struct page_ext *page_ext;
	unsigned long pad;
#endif
	/*
	 * WARNING: mem_section must be a power-of-2 in size for the
	 * calculation and use of SECTION_ROOT_MASK to make sense.
	 */
};

#ifdef CONFIG_SPARSEMEM_EXTREME
#define SECTIONS_PER_ROOT       (PAGE_SIZE / sizeof (struct mem_section))
#else
#define SECTIONS_PER_ROOT	1
#endif

#define SECTION_NR_TO_ROOT(sec)	((sec) / SECTIONS_PER_ROOT)
#define NR_SECTION_ROOTS	DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT)
#define SECTION_ROOT_MASK	(SECTIONS_PER_ROOT - 1)

#ifdef CONFIG_SPARSEMEM_EXTREME
extern struct mem_section **mem_section;
#else
extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
#endif

static inline unsigned long *section_to_usemap(struct mem_section *ms)
{
	return ms->usage->pageblock_flags;
}

static inline struct mem_section *__nr_to_section(unsigned long nr)
{
#ifdef CONFIG_SPARSEMEM_EXTREME
	if (!mem_section)
		return NULL;
#endif
	if (!mem_section[SECTION_NR_TO_ROOT(nr)])
		return NULL;
	return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
}
extern size_t mem_section_usage_size(void);

/*
 * We use the lower bits of the mem_map pointer to store
 * a little bit of information.  The pointer is calculated
 * as mem_map - section_nr_to_pfn(pnum).  The result is
 * aligned to the minimum alignment of the two values:
 *   1. All mem_map arrays are page-aligned.
 *   2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT
 *      lowest bits.  PFN_SECTION_SHIFT is arch-specific
 *      (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the
 *      worst combination is powerpc with 256k pages,
 *      which results in PFN_SECTION_SHIFT equal 6.
 * To sum it up, at least 6 bits are available.
 */
#define SECTION_MARKED_PRESENT		(1UL<<0)
#define SECTION_HAS_MEM_MAP		(1UL<<1)
#define SECTION_IS_ONLINE		(1UL<<2)
#define SECTION_IS_EARLY		(1UL<<3)
#define SECTION_TAINT_ZONE_DEVICE	(1UL<<4)
#define SECTION_MAP_LAST_BIT		(1UL<<5)
#define SECTION_MAP_MASK		(~(SECTION_MAP_LAST_BIT-1))
#define SECTION_NID_SHIFT		6

static inline struct page *__section_mem_map_addr(struct mem_section *section)
{
	unsigned long map = section->section_mem_map;
	map &= SECTION_MAP_MASK;
	return (struct page *)map;
}

static inline int present_section(struct mem_section *section)
{
	return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
}

static inline int present_section_nr(unsigned long nr)
{
	return present_section(__nr_to_section(nr));
}

static inline int valid_section(struct mem_section *section)
{
	return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
}

static inline int early_section(struct mem_section *section)
{
	return (section && (section->section_mem_map & SECTION_IS_EARLY));
}

static inline int valid_section_nr(unsigned long nr)
{
	return valid_section(__nr_to_section(nr));
}

static inline int online_section(struct mem_section *section)
{
	return (section && (section->section_mem_map & SECTION_IS_ONLINE));
}

static inline int online_device_section(struct mem_section *section)
{
	unsigned long flags = SECTION_IS_ONLINE | SECTION_TAINT_ZONE_DEVICE;

	return section && ((section->section_mem_map & flags) == flags);
}

static inline int online_section_nr(unsigned long nr)
{
	return online_section(__nr_to_section(nr));
}

#ifdef CONFIG_MEMORY_HOTPLUG
void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
#endif

static inline struct mem_section *__pfn_to_section(unsigned long pfn)
{
	return __nr_to_section(pfn_to_section_nr(pfn));
}

extern unsigned long __highest_present_section_nr;

static inline int subsection_map_index(unsigned long pfn)
{
	return (pfn & ~(PAGE_SECTION_MASK)) / PAGES_PER_SUBSECTION;
}

#ifdef CONFIG_SPARSEMEM_VMEMMAP
static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
{
	int idx = subsection_map_index(pfn);

	return test_bit(idx, ms->usage->subsection_map);
}
#else
static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
{
	return 1;
}
#endif

#ifndef CONFIG_HAVE_ARCH_PFN_VALID
/**
 * pfn_valid - check if there is a valid memory map entry for a PFN
 * @pfn: the page frame number to check
 *
 * Check if there is a valid memory map entry aka struct page for the @pfn.
 * Note, that availability of the memory map entry does not imply that
 * there is actual usable memory at that @pfn. The struct page may
 * represent a hole or an unusable page frame.
 *
 * Return: 1 for PFNs that have memory map entries and 0 otherwise
 */
static inline int pfn_valid(unsigned long pfn)
{
	struct mem_section *ms;

	/*
	 * Ensure the upper PAGE_SHIFT bits are clear in the
	 * pfn. Else it might lead to false positives when
	 * some of the upper bits are set, but the lower bits
	 * match a valid pfn.
	 */
	if (PHYS_PFN(PFN_PHYS(pfn)) != pfn)
		return 0;

	if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
		return 0;
	ms = __pfn_to_section(pfn);
	if (!valid_section(ms))
		return 0;
	/*
	 * Traditionally early sections always returned pfn_valid() for
	 * the entire section-sized span.
	 */
	return early_section(ms) || pfn_section_valid(ms, pfn);
}
#endif

static inline int pfn_in_present_section(unsigned long pfn)
{
	if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
		return 0;
	return present_section(__pfn_to_section(pfn));
}

static inline unsigned long next_present_section_nr(unsigned long section_nr)
{
	while (++section_nr <= __highest_present_section_nr) {
		if (present_section_nr(section_nr))
			return section_nr;
	}

	return -1;
}

/*
 * These are _only_ used during initialisation, therefore they
 * can use __initdata ...  They could have names to indicate
 * this restriction.
 */
#ifdef CONFIG_NUMA
#define pfn_to_nid(pfn)							\
({									\
	unsigned long __pfn_to_nid_pfn = (pfn);				\
	page_to_nid(pfn_to_page(__pfn_to_nid_pfn));			\
})
#else
#define pfn_to_nid(pfn)		(0)
#endif

void sparse_init(void);
#else
#define sparse_init()	do {} while (0)
#define sparse_index_init(_sec, _nid)  do {} while (0)
#define pfn_in_present_section pfn_valid
#define subsection_map_init(_pfn, _nr_pages) do {} while (0)
#endif /* CONFIG_SPARSEMEM */

#endif /* !__GENERATING_BOUNDS.H */
#endif /* !__ASSEMBLY__ */
#endif /* _LINUX_MMZONE_H */