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