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 <linux/zswap.h> 26 #include <asm/page.h> 27 28 /* Free memory management - zoned buddy allocator. */ 29 #ifndef CONFIG_ARCH_FORCE_MAX_ORDER 30 #define MAX_PAGE_ORDER 10 31 #else 32 #define MAX_PAGE_ORDER CONFIG_ARCH_FORCE_MAX_ORDER 33 #endif 34 #define MAX_ORDER_NR_PAGES (1 << MAX_PAGE_ORDER) 35 36 #define IS_MAX_ORDER_ALIGNED(pfn) IS_ALIGNED(pfn, MAX_ORDER_NR_PAGES) 37 38 #define NR_PAGE_ORDERS (MAX_PAGE_ORDER + 1) 39 40 /* 41 * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed 42 * costly to service. That is between allocation orders which should 43 * coalesce naturally under reasonable reclaim pressure and those which 44 * will not. 45 */ 46 #define PAGE_ALLOC_COSTLY_ORDER 3 47 48 enum migratetype { 49 MIGRATE_UNMOVABLE, 50 MIGRATE_MOVABLE, 51 MIGRATE_RECLAIMABLE, 52 MIGRATE_PCPTYPES, /* the number of types on the pcp lists */ 53 MIGRATE_HIGHATOMIC = MIGRATE_PCPTYPES, 54 #ifdef CONFIG_CMA 55 /* 56 * MIGRATE_CMA migration type is designed to mimic the way 57 * ZONE_MOVABLE works. Only movable pages can be allocated 58 * from MIGRATE_CMA pageblocks and page allocator never 59 * implicitly change migration type of MIGRATE_CMA pageblock. 60 * 61 * The way to use it is to change migratetype of a range of 62 * pageblocks to MIGRATE_CMA which can be done by 63 * __free_pageblock_cma() function. 64 */ 65 MIGRATE_CMA, 66 #endif 67 #ifdef CONFIG_MEMORY_ISOLATION 68 MIGRATE_ISOLATE, /* can't allocate from here */ 69 #endif 70 MIGRATE_TYPES 71 }; 72 73 /* In mm/page_alloc.c; keep in sync also with show_migration_types() there */ 74 extern const char * const migratetype_names[MIGRATE_TYPES]; 75 76 #ifdef CONFIG_CMA 77 # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA) 78 # define is_migrate_cma_page(_page) (get_pageblock_migratetype(_page) == MIGRATE_CMA) 79 # define is_migrate_cma_folio(folio, pfn) (MIGRATE_CMA == \ 80 get_pfnblock_flags_mask(&folio->page, pfn, MIGRATETYPE_MASK)) 81 #else 82 # define is_migrate_cma(migratetype) false 83 # define is_migrate_cma_page(_page) false 84 # define is_migrate_cma_folio(folio, pfn) false 85 #endif 86 is_migrate_movable(int mt)87 static inline bool is_migrate_movable(int mt) 88 { 89 return is_migrate_cma(mt) || mt == MIGRATE_MOVABLE; 90 } 91 92 /* 93 * Check whether a migratetype can be merged with another migratetype. 94 * 95 * It is only mergeable when it can fall back to other migratetypes for 96 * allocation. See fallbacks[MIGRATE_TYPES][3] in page_alloc.c. 97 */ migratetype_is_mergeable(int mt)98 static inline bool migratetype_is_mergeable(int mt) 99 { 100 return mt < MIGRATE_PCPTYPES; 101 } 102 103 #define for_each_migratetype_order(order, type) \ 104 for (order = 0; order < NR_PAGE_ORDERS; order++) \ 105 for (type = 0; type < MIGRATE_TYPES; type++) 106 107 extern int page_group_by_mobility_disabled; 108 109 #define MIGRATETYPE_MASK ((1UL << PB_migratetype_bits) - 1) 110 111 #define get_pageblock_migratetype(page) \ 112 get_pfnblock_flags_mask(page, page_to_pfn(page), MIGRATETYPE_MASK) 113 114 #define folio_migratetype(folio) \ 115 get_pfnblock_flags_mask(&folio->page, folio_pfn(folio), \ 116 MIGRATETYPE_MASK) 117 struct free_area { 118 struct list_head free_list[MIGRATE_TYPES]; 119 unsigned long nr_free; 120 }; 121 122 struct pglist_data; 123 124 #ifdef CONFIG_NUMA 125 enum numa_stat_item { 126 NUMA_HIT, /* allocated in intended node */ 127 NUMA_MISS, /* allocated in non intended node */ 128 NUMA_FOREIGN, /* was intended here, hit elsewhere */ 129 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */ 130 NUMA_LOCAL, /* allocation from local node */ 131 NUMA_OTHER, /* allocation from other node */ 132 NR_VM_NUMA_EVENT_ITEMS 133 }; 134 #else 135 #define NR_VM_NUMA_EVENT_ITEMS 0 136 #endif 137 138 enum zone_stat_item { 139 /* First 128 byte cacheline (assuming 64 bit words) */ 140 NR_FREE_PAGES, 141 NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */ 142 NR_ZONE_INACTIVE_ANON = NR_ZONE_LRU_BASE, 143 NR_ZONE_ACTIVE_ANON, 144 NR_ZONE_INACTIVE_FILE, 145 NR_ZONE_ACTIVE_FILE, 146 NR_ZONE_UNEVICTABLE, 147 NR_ZONE_WRITE_PENDING, /* Count of dirty, writeback and unstable pages */ 148 NR_MLOCK, /* mlock()ed pages found and moved off LRU */ 149 /* Second 128 byte cacheline */ 150 NR_BOUNCE, 151 #if IS_ENABLED(CONFIG_ZSMALLOC) 152 NR_ZSPAGES, /* allocated in zsmalloc */ 153 #endif 154 NR_FREE_CMA_PAGES, 155 #ifdef CONFIG_UNACCEPTED_MEMORY 156 NR_UNACCEPTED, 157 #endif 158 NR_VM_ZONE_STAT_ITEMS }; 159 160 enum node_stat_item { 161 NR_LRU_BASE, 162 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */ 163 NR_ACTIVE_ANON, /* " " " " " */ 164 NR_INACTIVE_FILE, /* " " " " " */ 165 NR_ACTIVE_FILE, /* " " " " " */ 166 NR_UNEVICTABLE, /* " " " " " */ 167 NR_SLAB_RECLAIMABLE_B, 168 NR_SLAB_UNRECLAIMABLE_B, 169 NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */ 170 NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */ 171 WORKINGSET_NODES, 172 WORKINGSET_REFAULT_BASE, 173 WORKINGSET_REFAULT_ANON = WORKINGSET_REFAULT_BASE, 174 WORKINGSET_REFAULT_FILE, 175 WORKINGSET_ACTIVATE_BASE, 176 WORKINGSET_ACTIVATE_ANON = WORKINGSET_ACTIVATE_BASE, 177 WORKINGSET_ACTIVATE_FILE, 178 WORKINGSET_RESTORE_BASE, 179 WORKINGSET_RESTORE_ANON = WORKINGSET_RESTORE_BASE, 180 WORKINGSET_RESTORE_FILE, 181 WORKINGSET_NODERECLAIM, 182 NR_ANON_MAPPED, /* Mapped anonymous pages */ 183 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables. 184 only modified from process context */ 185 NR_FILE_PAGES, 186 NR_FILE_DIRTY, 187 NR_WRITEBACK, 188 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */ 189 NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */ 190 NR_SHMEM_THPS, 191 NR_SHMEM_PMDMAPPED, 192 NR_FILE_THPS, 193 NR_FILE_PMDMAPPED, 194 NR_ANON_THPS, 195 NR_VMSCAN_WRITE, 196 NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */ 197 NR_DIRTIED, /* page dirtyings since bootup */ 198 NR_WRITTEN, /* page writings since bootup */ 199 NR_THROTTLED_WRITTEN, /* NR_WRITTEN while reclaim throttled */ 200 NR_KERNEL_MISC_RECLAIMABLE, /* reclaimable non-slab kernel pages */ 201 NR_FOLL_PIN_ACQUIRED, /* via: pin_user_page(), gup flag: FOLL_PIN */ 202 NR_FOLL_PIN_RELEASED, /* pages returned via unpin_user_page() */ 203 NR_KERNEL_STACK_KB, /* measured in KiB */ 204 #if IS_ENABLED(CONFIG_SHADOW_CALL_STACK) 205 NR_KERNEL_SCS_KB, /* measured in KiB */ 206 #endif 207 NR_PAGETABLE, /* used for pagetables */ 208 NR_SECONDARY_PAGETABLE, /* secondary pagetables, KVM & IOMMU */ 209 #ifdef CONFIG_IOMMU_SUPPORT 210 NR_IOMMU_PAGES, /* # of pages allocated by IOMMU */ 211 #endif 212 #ifdef CONFIG_SWAP 213 NR_SWAPCACHE, 214 #endif 215 #ifdef CONFIG_NUMA_BALANCING 216 PGPROMOTE_SUCCESS, /* promote successfully */ 217 PGPROMOTE_CANDIDATE, /* candidate pages to promote */ 218 #endif 219 /* PGDEMOTE_*: pages demoted */ 220 PGDEMOTE_KSWAPD, 221 PGDEMOTE_DIRECT, 222 PGDEMOTE_KHUGEPAGED, 223 NR_VM_NODE_STAT_ITEMS 224 }; 225 226 /* 227 * Returns true if the item should be printed in THPs (/proc/vmstat 228 * currently prints number of anon, file and shmem THPs. But the item 229 * is charged in pages). 230 */ vmstat_item_print_in_thp(enum node_stat_item item)231 static __always_inline bool vmstat_item_print_in_thp(enum node_stat_item item) 232 { 233 if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) 234 return false; 235 236 return item == NR_ANON_THPS || 237 item == NR_FILE_THPS || 238 item == NR_SHMEM_THPS || 239 item == NR_SHMEM_PMDMAPPED || 240 item == NR_FILE_PMDMAPPED; 241 } 242 243 /* 244 * Returns true if the value is measured in bytes (most vmstat values are 245 * measured in pages). This defines the API part, the internal representation 246 * might be different. 247 */ vmstat_item_in_bytes(int idx)248 static __always_inline bool vmstat_item_in_bytes(int idx) 249 { 250 /* 251 * Global and per-node slab counters track slab pages. 252 * It's expected that changes are multiples of PAGE_SIZE. 253 * Internally values are stored in pages. 254 * 255 * Per-memcg and per-lruvec counters track memory, consumed 256 * by individual slab objects. These counters are actually 257 * byte-precise. 258 */ 259 return (idx == NR_SLAB_RECLAIMABLE_B || 260 idx == NR_SLAB_UNRECLAIMABLE_B); 261 } 262 263 /* 264 * We do arithmetic on the LRU lists in various places in the code, 265 * so it is important to keep the active lists LRU_ACTIVE higher in 266 * the array than the corresponding inactive lists, and to keep 267 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists. 268 * 269 * This has to be kept in sync with the statistics in zone_stat_item 270 * above and the descriptions in vmstat_text in mm/vmstat.c 271 */ 272 #define LRU_BASE 0 273 #define LRU_ACTIVE 1 274 #define LRU_FILE 2 275 276 enum lru_list { 277 LRU_INACTIVE_ANON = LRU_BASE, 278 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE, 279 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE, 280 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE, 281 LRU_UNEVICTABLE, 282 NR_LRU_LISTS 283 }; 284 285 enum vmscan_throttle_state { 286 VMSCAN_THROTTLE_WRITEBACK, 287 VMSCAN_THROTTLE_ISOLATED, 288 VMSCAN_THROTTLE_NOPROGRESS, 289 VMSCAN_THROTTLE_CONGESTED, 290 NR_VMSCAN_THROTTLE, 291 }; 292 293 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++) 294 295 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++) 296 is_file_lru(enum lru_list lru)297 static inline bool is_file_lru(enum lru_list lru) 298 { 299 return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE); 300 } 301 is_active_lru(enum lru_list lru)302 static inline bool is_active_lru(enum lru_list lru) 303 { 304 return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE); 305 } 306 307 #define WORKINGSET_ANON 0 308 #define WORKINGSET_FILE 1 309 #define ANON_AND_FILE 2 310 311 enum lruvec_flags { 312 /* 313 * An lruvec has many dirty pages backed by a congested BDI: 314 * 1. LRUVEC_CGROUP_CONGESTED is set by cgroup-level reclaim. 315 * It can be cleared by cgroup reclaim or kswapd. 316 * 2. LRUVEC_NODE_CONGESTED is set by kswapd node-level reclaim. 317 * It can only be cleared by kswapd. 318 * 319 * Essentially, kswapd can unthrottle an lruvec throttled by cgroup 320 * reclaim, but not vice versa. This only applies to the root cgroup. 321 * The goal is to prevent cgroup reclaim on the root cgroup (e.g. 322 * memory.reclaim) to unthrottle an unbalanced node (that was throttled 323 * by kswapd). 324 */ 325 LRUVEC_CGROUP_CONGESTED, 326 LRUVEC_NODE_CONGESTED, 327 }; 328 329 #endif /* !__GENERATING_BOUNDS_H */ 330 331 /* 332 * Evictable pages are divided into multiple generations. The youngest and the 333 * oldest generation numbers, max_seq and min_seq, are monotonically increasing. 334 * They form a sliding window of a variable size [MIN_NR_GENS, MAX_NR_GENS]. An 335 * offset within MAX_NR_GENS, i.e., gen, indexes the LRU list of the 336 * corresponding generation. The gen counter in folio->flags stores gen+1 while 337 * a page is on one of lrugen->folios[]. Otherwise it stores 0. 338 * 339 * A page is added to the youngest generation on faulting. The aging needs to 340 * check the accessed bit at least twice before handing this page over to the 341 * eviction. The first check takes care of the accessed bit set on the initial 342 * fault; the second check makes sure this page hasn't been used since then. 343 * This process, AKA second chance, requires a minimum of two generations, 344 * hence MIN_NR_GENS. And to maintain ABI compatibility with the active/inactive 345 * LRU, e.g., /proc/vmstat, these two generations are considered active; the 346 * rest of generations, if they exist, are considered inactive. See 347 * lru_gen_is_active(). 348 * 349 * PG_active is always cleared while a page is on one of lrugen->folios[] so 350 * that the aging needs not to worry about it. And it's set again when a page 351 * considered active is isolated for non-reclaiming purposes, e.g., migration. 352 * See lru_gen_add_folio() and lru_gen_del_folio(). 353 * 354 * MAX_NR_GENS is set to 4 so that the multi-gen LRU can support twice the 355 * number of categories of the active/inactive LRU when keeping track of 356 * accesses through page tables. This requires order_base_2(MAX_NR_GENS+1) bits 357 * in folio->flags. 358 */ 359 #define MIN_NR_GENS 2U 360 #define MAX_NR_GENS 4U 361 362 /* 363 * Each generation is divided into multiple tiers. A page accessed N times 364 * through file descriptors is in tier order_base_2(N). A page in the first tier 365 * (N=0,1) is marked by PG_referenced unless it was faulted in through page 366 * tables or read ahead. A page in any other tier (N>1) is marked by 367 * PG_referenced and PG_workingset. This implies a minimum of two tiers is 368 * supported without using additional bits in folio->flags. 369 * 370 * In contrast to moving across generations which requires the LRU lock, moving 371 * across tiers only involves atomic operations on folio->flags and therefore 372 * has a negligible cost in the buffered access path. In the eviction path, 373 * comparisons of refaulted/(evicted+protected) from the first tier and the 374 * rest infer whether pages accessed multiple times through file descriptors 375 * are statistically hot and thus worth protecting. 376 * 377 * MAX_NR_TIERS is set to 4 so that the multi-gen LRU can support twice the 378 * number of categories of the active/inactive LRU when keeping track of 379 * accesses through file descriptors. This uses MAX_NR_TIERS-2 spare bits in 380 * folio->flags. 381 */ 382 #define MAX_NR_TIERS 4U 383 384 #ifndef __GENERATING_BOUNDS_H 385 386 struct lruvec; 387 struct page_vma_mapped_walk; 388 389 #define LRU_GEN_MASK ((BIT(LRU_GEN_WIDTH) - 1) << LRU_GEN_PGOFF) 390 #define LRU_REFS_MASK ((BIT(LRU_REFS_WIDTH) - 1) << LRU_REFS_PGOFF) 391 392 #ifdef CONFIG_LRU_GEN 393 394 enum { 395 LRU_GEN_ANON, 396 LRU_GEN_FILE, 397 }; 398 399 enum { 400 LRU_GEN_CORE, 401 LRU_GEN_MM_WALK, 402 LRU_GEN_NONLEAF_YOUNG, 403 NR_LRU_GEN_CAPS 404 }; 405 406 #define MIN_LRU_BATCH BITS_PER_LONG 407 #define MAX_LRU_BATCH (MIN_LRU_BATCH * 64) 408 409 /* whether to keep historical stats from evicted generations */ 410 #ifdef CONFIG_LRU_GEN_STATS 411 #define NR_HIST_GENS MAX_NR_GENS 412 #else 413 #define NR_HIST_GENS 1U 414 #endif 415 416 /* 417 * The youngest generation number is stored in max_seq for both anon and file 418 * types as they are aged on an equal footing. The oldest generation numbers are 419 * stored in min_seq[] separately for anon and file types as clean file pages 420 * can be evicted regardless of swap constraints. 421 * 422 * Normally anon and file min_seq are in sync. But if swapping is constrained, 423 * e.g., out of swap space, file min_seq is allowed to advance and leave anon 424 * min_seq behind. 425 * 426 * The number of pages in each generation is eventually consistent and therefore 427 * can be transiently negative when reset_batch_size() is pending. 428 */ 429 struct lru_gen_folio { 430 /* the aging increments the youngest generation number */ 431 unsigned long max_seq; 432 /* the eviction increments the oldest generation numbers */ 433 unsigned long min_seq[ANON_AND_FILE]; 434 /* the birth time of each generation in jiffies */ 435 unsigned long timestamps[MAX_NR_GENS]; 436 /* the multi-gen LRU lists, lazily sorted on eviction */ 437 struct list_head folios[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES]; 438 /* the multi-gen LRU sizes, eventually consistent */ 439 long nr_pages[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES]; 440 /* the exponential moving average of refaulted */ 441 unsigned long avg_refaulted[ANON_AND_FILE][MAX_NR_TIERS]; 442 /* the exponential moving average of evicted+protected */ 443 unsigned long avg_total[ANON_AND_FILE][MAX_NR_TIERS]; 444 /* the first tier doesn't need protection, hence the minus one */ 445 unsigned long protected[NR_HIST_GENS][ANON_AND_FILE][MAX_NR_TIERS - 1]; 446 /* can be modified without holding the LRU lock */ 447 atomic_long_t evicted[NR_HIST_GENS][ANON_AND_FILE][MAX_NR_TIERS]; 448 atomic_long_t refaulted[NR_HIST_GENS][ANON_AND_FILE][MAX_NR_TIERS]; 449 /* whether the multi-gen LRU is enabled */ 450 bool enabled; 451 /* the memcg generation this lru_gen_folio belongs to */ 452 u8 gen; 453 /* the list segment this lru_gen_folio belongs to */ 454 u8 seg; 455 /* per-node lru_gen_folio list for global reclaim */ 456 struct hlist_nulls_node list; 457 }; 458 459 enum { 460 MM_LEAF_TOTAL, /* total leaf entries */ 461 MM_LEAF_YOUNG, /* young leaf entries */ 462 MM_NONLEAF_FOUND, /* non-leaf entries found in Bloom filters */ 463 MM_NONLEAF_ADDED, /* non-leaf entries added to Bloom filters */ 464 NR_MM_STATS 465 }; 466 467 /* double-buffering Bloom filters */ 468 #define NR_BLOOM_FILTERS 2 469 470 struct lru_gen_mm_state { 471 /* synced with max_seq after each iteration */ 472 unsigned long seq; 473 /* where the current iteration continues after */ 474 struct list_head *head; 475 /* where the last iteration ended before */ 476 struct list_head *tail; 477 /* Bloom filters flip after each iteration */ 478 unsigned long *filters[NR_BLOOM_FILTERS]; 479 /* the mm stats for debugging */ 480 unsigned long stats[NR_HIST_GENS][NR_MM_STATS]; 481 }; 482 483 struct lru_gen_mm_walk { 484 /* the lruvec under reclaim */ 485 struct lruvec *lruvec; 486 /* max_seq from lru_gen_folio: can be out of date */ 487 unsigned long seq; 488 /* the next address within an mm to scan */ 489 unsigned long next_addr; 490 /* to batch promoted pages */ 491 int nr_pages[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES]; 492 /* to batch the mm stats */ 493 int mm_stats[NR_MM_STATS]; 494 /* total batched items */ 495 int batched; 496 bool can_swap; 497 bool force_scan; 498 }; 499 500 /* 501 * For each node, memcgs are divided into two generations: the old and the 502 * young. For each generation, memcgs are randomly sharded into multiple bins 503 * to improve scalability. For each bin, the hlist_nulls is virtually divided 504 * into three segments: the head, the tail and the default. 505 * 506 * An onlining memcg is added to the tail of a random bin in the old generation. 507 * The eviction starts at the head of a random bin in the old generation. The 508 * per-node memcg generation counter, whose reminder (mod MEMCG_NR_GENS) indexes 509 * the old generation, is incremented when all its bins become empty. 510 * 511 * There are four operations: 512 * 1. MEMCG_LRU_HEAD, which moves a memcg to the head of a random bin in its 513 * current generation (old or young) and updates its "seg" to "head"; 514 * 2. MEMCG_LRU_TAIL, which moves a memcg to the tail of a random bin in its 515 * current generation (old or young) and updates its "seg" to "tail"; 516 * 3. MEMCG_LRU_OLD, which moves a memcg to the head of a random bin in the old 517 * generation, updates its "gen" to "old" and resets its "seg" to "default"; 518 * 4. MEMCG_LRU_YOUNG, which moves a memcg to the tail of a random bin in the 519 * young generation, updates its "gen" to "young" and resets its "seg" to 520 * "default". 521 * 522 * The events that trigger the above operations are: 523 * 1. Exceeding the soft limit, which triggers MEMCG_LRU_HEAD; 524 * 2. The first attempt to reclaim a memcg below low, which triggers 525 * MEMCG_LRU_TAIL; 526 * 3. The first attempt to reclaim a memcg offlined or below reclaimable size 527 * threshold, which triggers MEMCG_LRU_TAIL; 528 * 4. The second attempt to reclaim a memcg offlined or below reclaimable size 529 * threshold, which triggers MEMCG_LRU_YOUNG; 530 * 5. Attempting to reclaim a memcg below min, which triggers MEMCG_LRU_YOUNG; 531 * 6. Finishing the aging on the eviction path, which triggers MEMCG_LRU_YOUNG; 532 * 7. Offlining a memcg, which triggers MEMCG_LRU_OLD. 533 * 534 * Notes: 535 * 1. Memcg LRU only applies to global reclaim, and the round-robin incrementing 536 * of their max_seq counters ensures the eventual fairness to all eligible 537 * memcgs. For memcg reclaim, it still relies on mem_cgroup_iter(). 538 * 2. There are only two valid generations: old (seq) and young (seq+1). 539 * MEMCG_NR_GENS is set to three so that when reading the generation counter 540 * locklessly, a stale value (seq-1) does not wraparound to young. 541 */ 542 #define MEMCG_NR_GENS 3 543 #define MEMCG_NR_BINS 8 544 545 struct lru_gen_memcg { 546 /* the per-node memcg generation counter */ 547 unsigned long seq; 548 /* each memcg has one lru_gen_folio per node */ 549 unsigned long nr_memcgs[MEMCG_NR_GENS]; 550 /* per-node lru_gen_folio list for global reclaim */ 551 struct hlist_nulls_head fifo[MEMCG_NR_GENS][MEMCG_NR_BINS]; 552 /* protects the above */ 553 spinlock_t lock; 554 }; 555 556 void lru_gen_init_pgdat(struct pglist_data *pgdat); 557 void lru_gen_init_lruvec(struct lruvec *lruvec); 558 bool lru_gen_look_around(struct page_vma_mapped_walk *pvmw); 559 560 void lru_gen_init_memcg(struct mem_cgroup *memcg); 561 void lru_gen_exit_memcg(struct mem_cgroup *memcg); 562 void lru_gen_online_memcg(struct mem_cgroup *memcg); 563 void lru_gen_offline_memcg(struct mem_cgroup *memcg); 564 void lru_gen_release_memcg(struct mem_cgroup *memcg); 565 void lru_gen_soft_reclaim(struct mem_cgroup *memcg, int nid); 566 567 #else /* !CONFIG_LRU_GEN */ 568 lru_gen_init_pgdat(struct pglist_data * pgdat)569 static inline void lru_gen_init_pgdat(struct pglist_data *pgdat) 570 { 571 } 572 lru_gen_init_lruvec(struct lruvec * lruvec)573 static inline void lru_gen_init_lruvec(struct lruvec *lruvec) 574 { 575 } 576 lru_gen_look_around(struct page_vma_mapped_walk * pvmw)577 static inline bool lru_gen_look_around(struct page_vma_mapped_walk *pvmw) 578 { 579 return false; 580 } 581 lru_gen_init_memcg(struct mem_cgroup * memcg)582 static inline void lru_gen_init_memcg(struct mem_cgroup *memcg) 583 { 584 } 585 lru_gen_exit_memcg(struct mem_cgroup * memcg)586 static inline void lru_gen_exit_memcg(struct mem_cgroup *memcg) 587 { 588 } 589 lru_gen_online_memcg(struct mem_cgroup * memcg)590 static inline void lru_gen_online_memcg(struct mem_cgroup *memcg) 591 { 592 } 593 lru_gen_offline_memcg(struct mem_cgroup * memcg)594 static inline void lru_gen_offline_memcg(struct mem_cgroup *memcg) 595 { 596 } 597 lru_gen_release_memcg(struct mem_cgroup * memcg)598 static inline void lru_gen_release_memcg(struct mem_cgroup *memcg) 599 { 600 } 601 lru_gen_soft_reclaim(struct mem_cgroup * memcg,int nid)602 static inline void lru_gen_soft_reclaim(struct mem_cgroup *memcg, int nid) 603 { 604 } 605 606 #endif /* CONFIG_LRU_GEN */ 607 608 struct lruvec { 609 struct list_head lists[NR_LRU_LISTS]; 610 /* per lruvec lru_lock for memcg */ 611 spinlock_t lru_lock; 612 /* 613 * These track the cost of reclaiming one LRU - file or anon - 614 * over the other. As the observed cost of reclaiming one LRU 615 * increases, the reclaim scan balance tips toward the other. 616 */ 617 unsigned long anon_cost; 618 unsigned long file_cost; 619 /* Non-resident age, driven by LRU movement */ 620 atomic_long_t nonresident_age; 621 /* Refaults at the time of last reclaim cycle */ 622 unsigned long refaults[ANON_AND_FILE]; 623 /* Various lruvec state flags (enum lruvec_flags) */ 624 unsigned long flags; 625 #ifdef CONFIG_LRU_GEN 626 /* evictable pages divided into generations */ 627 struct lru_gen_folio lrugen; 628 #ifdef CONFIG_LRU_GEN_WALKS_MMU 629 /* to concurrently iterate lru_gen_mm_list */ 630 struct lru_gen_mm_state mm_state; 631 #endif 632 #endif /* CONFIG_LRU_GEN */ 633 #ifdef CONFIG_MEMCG 634 struct pglist_data *pgdat; 635 #endif 636 struct zswap_lruvec_state zswap_lruvec_state; 637 }; 638 639 /* Isolate for asynchronous migration */ 640 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4) 641 /* Isolate unevictable pages */ 642 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8) 643 644 /* LRU Isolation modes. */ 645 typedef unsigned __bitwise isolate_mode_t; 646 647 enum zone_watermarks { 648 WMARK_MIN, 649 WMARK_LOW, 650 WMARK_HIGH, 651 WMARK_PROMO, 652 NR_WMARK 653 }; 654 655 /* 656 * One per migratetype for each PAGE_ALLOC_COSTLY_ORDER. Two additional lists 657 * are added for THP. One PCP list is used by GPF_MOVABLE, and the other PCP list 658 * is used by GFP_UNMOVABLE and GFP_RECLAIMABLE. 659 */ 660 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 661 #define NR_PCP_THP 2 662 #else 663 #define NR_PCP_THP 0 664 #endif 665 #define NR_LOWORDER_PCP_LISTS (MIGRATE_PCPTYPES * (PAGE_ALLOC_COSTLY_ORDER + 1)) 666 #define NR_PCP_LISTS (NR_LOWORDER_PCP_LISTS + NR_PCP_THP) 667 668 /* 669 * Flags used in pcp->flags field. 670 * 671 * PCPF_PREV_FREE_HIGH_ORDER: a high-order page is freed in the 672 * previous page freeing. To avoid to drain PCP for an accident 673 * high-order page freeing. 674 * 675 * PCPF_FREE_HIGH_BATCH: preserve "pcp->batch" pages in PCP before 676 * draining PCP for consecutive high-order pages freeing without 677 * allocation if data cache slice of CPU is large enough. To reduce 678 * zone lock contention and keep cache-hot pages reusing. 679 */ 680 #define PCPF_PREV_FREE_HIGH_ORDER BIT(0) 681 #define PCPF_FREE_HIGH_BATCH BIT(1) 682 683 struct per_cpu_pages { 684 spinlock_t lock; /* Protects lists field */ 685 int count; /* number of pages in the list */ 686 int high; /* high watermark, emptying needed */ 687 int high_min; /* min high watermark */ 688 int high_max; /* max high watermark */ 689 int batch; /* chunk size for buddy add/remove */ 690 u8 flags; /* protected by pcp->lock */ 691 u8 alloc_factor; /* batch scaling factor during allocate */ 692 #ifdef CONFIG_NUMA 693 u8 expire; /* When 0, remote pagesets are drained */ 694 #endif 695 short free_count; /* consecutive free count */ 696 697 /* Lists of pages, one per migrate type stored on the pcp-lists */ 698 struct list_head lists[NR_PCP_LISTS]; 699 } ____cacheline_aligned_in_smp; 700 701 struct per_cpu_zonestat { 702 #ifdef CONFIG_SMP 703 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS]; 704 s8 stat_threshold; 705 #endif 706 #ifdef CONFIG_NUMA 707 /* 708 * Low priority inaccurate counters that are only folded 709 * on demand. Use a large type to avoid the overhead of 710 * folding during refresh_cpu_vm_stats. 711 */ 712 unsigned long vm_numa_event[NR_VM_NUMA_EVENT_ITEMS]; 713 #endif 714 }; 715 716 struct per_cpu_nodestat { 717 s8 stat_threshold; 718 s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS]; 719 }; 720 721 #endif /* !__GENERATING_BOUNDS.H */ 722 723 enum zone_type { 724 /* 725 * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able 726 * to DMA to all of the addressable memory (ZONE_NORMAL). 727 * On architectures where this area covers the whole 32 bit address 728 * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller 729 * DMA addressing constraints. This distinction is important as a 32bit 730 * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit 731 * platforms may need both zones as they support peripherals with 732 * different DMA addressing limitations. 733 */ 734 #ifdef CONFIG_ZONE_DMA 735 ZONE_DMA, 736 #endif 737 #ifdef CONFIG_ZONE_DMA32 738 ZONE_DMA32, 739 #endif 740 /* 741 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be 742 * performed on pages in ZONE_NORMAL if the DMA devices support 743 * transfers to all addressable memory. 744 */ 745 ZONE_NORMAL, 746 #ifdef CONFIG_HIGHMEM 747 /* 748 * A memory area that is only addressable by the kernel through 749 * mapping portions into its own address space. This is for example 750 * used by i386 to allow the kernel to address the memory beyond 751 * 900MB. The kernel will set up special mappings (page 752 * table entries on i386) for each page that the kernel needs to 753 * access. 754 */ 755 ZONE_HIGHMEM, 756 #endif 757 /* 758 * ZONE_MOVABLE is similar to ZONE_NORMAL, except that it contains 759 * movable pages with few exceptional cases described below. Main use 760 * cases for ZONE_MOVABLE are to make memory offlining/unplug more 761 * likely to succeed, and to locally limit unmovable allocations - e.g., 762 * to increase the number of THP/huge pages. Notable special cases are: 763 * 764 * 1. Pinned pages: (long-term) pinning of movable pages might 765 * essentially turn such pages unmovable. Therefore, we do not allow 766 * pinning long-term pages in ZONE_MOVABLE. When pages are pinned and 767 * faulted, they come from the right zone right away. However, it is 768 * still possible that address space already has pages in 769 * ZONE_MOVABLE at the time when pages are pinned (i.e. user has 770 * touches that memory before pinning). In such case we migrate them 771 * to a different zone. When migration fails - pinning fails. 772 * 2. memblock allocations: kernelcore/movablecore setups might create 773 * situations where ZONE_MOVABLE contains unmovable allocations 774 * after boot. Memory offlining and allocations fail early. 775 * 3. Memory holes: kernelcore/movablecore setups might create very rare 776 * situations where ZONE_MOVABLE contains memory holes after boot, 777 * for example, if we have sections that are only partially 778 * populated. Memory offlining and allocations fail early. 779 * 4. PG_hwpoison pages: while poisoned pages can be skipped during 780 * memory offlining, such pages cannot be allocated. 781 * 5. Unmovable PG_offline pages: in paravirtualized environments, 782 * hotplugged memory blocks might only partially be managed by the 783 * buddy (e.g., via XEN-balloon, Hyper-V balloon, virtio-mem). The 784 * parts not manged by the buddy are unmovable PG_offline pages. In 785 * some cases (virtio-mem), such pages can be skipped during 786 * memory offlining, however, cannot be moved/allocated. These 787 * techniques might use alloc_contig_range() to hide previously 788 * exposed pages from the buddy again (e.g., to implement some sort 789 * of memory unplug in virtio-mem). 790 * 6. ZERO_PAGE(0), kernelcore/movablecore setups might create 791 * situations where ZERO_PAGE(0) which is allocated differently 792 * on different platforms may end up in a movable zone. ZERO_PAGE(0) 793 * cannot be migrated. 794 * 7. Memory-hotplug: when using memmap_on_memory and onlining the 795 * memory to the MOVABLE zone, the vmemmap pages are also placed in 796 * such zone. Such pages cannot be really moved around as they are 797 * self-stored in the range, but they are treated as movable when 798 * the range they describe is about to be offlined. 799 * 800 * In general, no unmovable allocations that degrade memory offlining 801 * should end up in ZONE_MOVABLE. Allocators (like alloc_contig_range()) 802 * have to expect that migrating pages in ZONE_MOVABLE can fail (even 803 * if has_unmovable_pages() states that there are no unmovable pages, 804 * there can be false negatives). 805 */ 806 ZONE_MOVABLE, 807 #ifdef CONFIG_ZONE_DEVICE 808 ZONE_DEVICE, 809 #endif 810 __MAX_NR_ZONES 811 812 }; 813 814 #ifndef __GENERATING_BOUNDS_H 815 816 #define ASYNC_AND_SYNC 2 817 818 struct zone { 819 /* Read-mostly fields */ 820 821 /* zone watermarks, access with *_wmark_pages(zone) macros */ 822 unsigned long _watermark[NR_WMARK]; 823 unsigned long watermark_boost; 824 825 unsigned long nr_reserved_highatomic; 826 unsigned long nr_free_highatomic; 827 828 /* 829 * We don't know if the memory that we're going to allocate will be 830 * freeable or/and it will be released eventually, so to avoid totally 831 * wasting several GB of ram we must reserve some of the lower zone 832 * memory (otherwise we risk to run OOM on the lower zones despite 833 * there being tons of freeable ram on the higher zones). This array is 834 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl 835 * changes. 836 */ 837 long lowmem_reserve[MAX_NR_ZONES]; 838 839 #ifdef CONFIG_NUMA 840 int node; 841 #endif 842 struct pglist_data *zone_pgdat; 843 struct per_cpu_pages __percpu *per_cpu_pageset; 844 struct per_cpu_zonestat __percpu *per_cpu_zonestats; 845 /* 846 * the high and batch values are copied to individual pagesets for 847 * faster access 848 */ 849 int pageset_high_min; 850 int pageset_high_max; 851 int pageset_batch; 852 853 #ifndef CONFIG_SPARSEMEM 854 /* 855 * Flags for a pageblock_nr_pages block. See pageblock-flags.h. 856 * In SPARSEMEM, this map is stored in struct mem_section 857 */ 858 unsigned long *pageblock_flags; 859 #endif /* CONFIG_SPARSEMEM */ 860 861 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */ 862 unsigned long zone_start_pfn; 863 864 /* 865 * spanned_pages is the total pages spanned by the zone, including 866 * holes, which is calculated as: 867 * spanned_pages = zone_end_pfn - zone_start_pfn; 868 * 869 * present_pages is physical pages existing within the zone, which 870 * is calculated as: 871 * present_pages = spanned_pages - absent_pages(pages in holes); 872 * 873 * present_early_pages is present pages existing within the zone 874 * located on memory available since early boot, excluding hotplugged 875 * memory. 876 * 877 * managed_pages is present pages managed by the buddy system, which 878 * is calculated as (reserved_pages includes pages allocated by the 879 * bootmem allocator): 880 * managed_pages = present_pages - reserved_pages; 881 * 882 * cma pages is present pages that are assigned for CMA use 883 * (MIGRATE_CMA). 884 * 885 * So present_pages may be used by memory hotplug or memory power 886 * management logic to figure out unmanaged pages by checking 887 * (present_pages - managed_pages). And managed_pages should be used 888 * by page allocator and vm scanner to calculate all kinds of watermarks 889 * and thresholds. 890 * 891 * Locking rules: 892 * 893 * zone_start_pfn and spanned_pages are protected by span_seqlock. 894 * It is a seqlock because it has to be read outside of zone->lock, 895 * and it is done in the main allocator path. But, it is written 896 * quite infrequently. 897 * 898 * The span_seq lock is declared along with zone->lock because it is 899 * frequently read in proximity to zone->lock. It's good to 900 * give them a chance of being in the same cacheline. 901 * 902 * Write access to present_pages at runtime should be protected by 903 * mem_hotplug_begin/done(). Any reader who can't tolerant drift of 904 * present_pages should use get_online_mems() to get a stable value. 905 */ 906 atomic_long_t managed_pages; 907 unsigned long spanned_pages; 908 unsigned long present_pages; 909 #if defined(CONFIG_MEMORY_HOTPLUG) 910 unsigned long present_early_pages; 911 #endif 912 #ifdef CONFIG_CMA 913 unsigned long cma_pages; 914 #endif 915 916 const char *name; 917 918 #ifdef CONFIG_MEMORY_ISOLATION 919 /* 920 * Number of isolated pageblock. It is used to solve incorrect 921 * freepage counting problem due to racy retrieving migratetype 922 * of pageblock. Protected by zone->lock. 923 */ 924 unsigned long nr_isolate_pageblock; 925 #endif 926 927 #ifdef CONFIG_MEMORY_HOTPLUG 928 /* see spanned/present_pages for more description */ 929 seqlock_t span_seqlock; 930 #endif 931 932 int initialized; 933 934 /* Write-intensive fields used from the page allocator */ 935 CACHELINE_PADDING(_pad1_); 936 937 /* free areas of different sizes */ 938 struct free_area free_area[NR_PAGE_ORDERS]; 939 940 #ifdef CONFIG_UNACCEPTED_MEMORY 941 /* Pages to be accepted. All pages on the list are MAX_PAGE_ORDER */ 942 struct list_head unaccepted_pages; 943 #endif 944 945 /* zone flags, see below */ 946 unsigned long flags; 947 948 /* Primarily protects free_area */ 949 spinlock_t lock; 950 951 /* Write-intensive fields used by compaction and vmstats. */ 952 CACHELINE_PADDING(_pad2_); 953 954 /* 955 * When free pages are below this point, additional steps are taken 956 * when reading the number of free pages to avoid per-cpu counter 957 * drift allowing watermarks to be breached 958 */ 959 unsigned long percpu_drift_mark; 960 961 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 962 /* pfn where compaction free scanner should start */ 963 unsigned long compact_cached_free_pfn; 964 /* pfn where compaction migration scanner should start */ 965 unsigned long compact_cached_migrate_pfn[ASYNC_AND_SYNC]; 966 unsigned long compact_init_migrate_pfn; 967 unsigned long compact_init_free_pfn; 968 #endif 969 970 #ifdef CONFIG_COMPACTION 971 /* 972 * On compaction failure, 1<<compact_defer_shift compactions 973 * are skipped before trying again. The number attempted since 974 * last failure is tracked with compact_considered. 975 * compact_order_failed is the minimum compaction failed order. 976 */ 977 unsigned int compact_considered; 978 unsigned int compact_defer_shift; 979 int compact_order_failed; 980 #endif 981 982 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 983 /* Set to true when the PG_migrate_skip bits should be cleared */ 984 bool compact_blockskip_flush; 985 #endif 986 987 bool contiguous; 988 989 CACHELINE_PADDING(_pad3_); 990 /* Zone statistics */ 991 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; 992 atomic_long_t vm_numa_event[NR_VM_NUMA_EVENT_ITEMS]; 993 } ____cacheline_internodealigned_in_smp; 994 995 enum pgdat_flags { 996 PGDAT_DIRTY, /* reclaim scanning has recently found 997 * many dirty file pages at the tail 998 * of the LRU. 999 */ 1000 PGDAT_WRITEBACK, /* reclaim scanning has recently found 1001 * many pages under writeback 1002 */ 1003 PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */ 1004 }; 1005 1006 enum zone_flags { 1007 ZONE_BOOSTED_WATERMARK, /* zone recently boosted watermarks. 1008 * Cleared when kswapd is woken. 1009 */ 1010 ZONE_RECLAIM_ACTIVE, /* kswapd may be scanning the zone. */ 1011 ZONE_BELOW_HIGH, /* zone is below high watermark. */ 1012 }; 1013 wmark_pages(const struct zone * z,enum zone_watermarks w)1014 static inline unsigned long wmark_pages(const struct zone *z, 1015 enum zone_watermarks w) 1016 { 1017 return z->_watermark[w] + z->watermark_boost; 1018 } 1019 min_wmark_pages(const struct zone * z)1020 static inline unsigned long min_wmark_pages(const struct zone *z) 1021 { 1022 return wmark_pages(z, WMARK_MIN); 1023 } 1024 low_wmark_pages(const struct zone * z)1025 static inline unsigned long low_wmark_pages(const struct zone *z) 1026 { 1027 return wmark_pages(z, WMARK_LOW); 1028 } 1029 high_wmark_pages(const struct zone * z)1030 static inline unsigned long high_wmark_pages(const struct zone *z) 1031 { 1032 return wmark_pages(z, WMARK_HIGH); 1033 } 1034 promo_wmark_pages(const struct zone * z)1035 static inline unsigned long promo_wmark_pages(const struct zone *z) 1036 { 1037 return wmark_pages(z, WMARK_PROMO); 1038 } 1039 zone_managed_pages(struct zone * zone)1040 static inline unsigned long zone_managed_pages(struct zone *zone) 1041 { 1042 return (unsigned long)atomic_long_read(&zone->managed_pages); 1043 } 1044 zone_cma_pages(struct zone * zone)1045 static inline unsigned long zone_cma_pages(struct zone *zone) 1046 { 1047 #ifdef CONFIG_CMA 1048 return zone->cma_pages; 1049 #else 1050 return 0; 1051 #endif 1052 } 1053 zone_end_pfn(const struct zone * zone)1054 static inline unsigned long zone_end_pfn(const struct zone *zone) 1055 { 1056 return zone->zone_start_pfn + zone->spanned_pages; 1057 } 1058 zone_spans_pfn(const struct zone * zone,unsigned long pfn)1059 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn) 1060 { 1061 return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone); 1062 } 1063 zone_is_initialized(struct zone * zone)1064 static inline bool zone_is_initialized(struct zone *zone) 1065 { 1066 return zone->initialized; 1067 } 1068 zone_is_empty(struct zone * zone)1069 static inline bool zone_is_empty(struct zone *zone) 1070 { 1071 return zone->spanned_pages == 0; 1072 } 1073 1074 #ifndef BUILD_VDSO32_64 1075 /* 1076 * The zone field is never updated after free_area_init_core() 1077 * sets it, so none of the operations on it need to be atomic. 1078 */ 1079 1080 /* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_CPUPID] | ... | FLAGS | */ 1081 #define SECTIONS_PGOFF ((sizeof(unsigned long)*8) - SECTIONS_WIDTH) 1082 #define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH) 1083 #define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH) 1084 #define LAST_CPUPID_PGOFF (ZONES_PGOFF - LAST_CPUPID_WIDTH) 1085 #define KASAN_TAG_PGOFF (LAST_CPUPID_PGOFF - KASAN_TAG_WIDTH) 1086 #define LRU_GEN_PGOFF (KASAN_TAG_PGOFF - LRU_GEN_WIDTH) 1087 #define LRU_REFS_PGOFF (LRU_GEN_PGOFF - LRU_REFS_WIDTH) 1088 1089 /* 1090 * Define the bit shifts to access each section. For non-existent 1091 * sections we define the shift as 0; that plus a 0 mask ensures 1092 * the compiler will optimise away reference to them. 1093 */ 1094 #define SECTIONS_PGSHIFT (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0)) 1095 #define NODES_PGSHIFT (NODES_PGOFF * (NODES_WIDTH != 0)) 1096 #define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_WIDTH != 0)) 1097 #define LAST_CPUPID_PGSHIFT (LAST_CPUPID_PGOFF * (LAST_CPUPID_WIDTH != 0)) 1098 #define KASAN_TAG_PGSHIFT (KASAN_TAG_PGOFF * (KASAN_TAG_WIDTH != 0)) 1099 1100 /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */ 1101 #ifdef NODE_NOT_IN_PAGE_FLAGS 1102 #define ZONEID_SHIFT (SECTIONS_SHIFT + ZONES_SHIFT) 1103 #define ZONEID_PGOFF ((SECTIONS_PGOFF < ZONES_PGOFF) ? \ 1104 SECTIONS_PGOFF : ZONES_PGOFF) 1105 #else 1106 #define ZONEID_SHIFT (NODES_SHIFT + ZONES_SHIFT) 1107 #define ZONEID_PGOFF ((NODES_PGOFF < ZONES_PGOFF) ? \ 1108 NODES_PGOFF : ZONES_PGOFF) 1109 #endif 1110 1111 #define ZONEID_PGSHIFT (ZONEID_PGOFF * (ZONEID_SHIFT != 0)) 1112 1113 #define ZONES_MASK ((1UL << ZONES_WIDTH) - 1) 1114 #define NODES_MASK ((1UL << NODES_WIDTH) - 1) 1115 #define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1) 1116 #define LAST_CPUPID_MASK ((1UL << LAST_CPUPID_SHIFT) - 1) 1117 #define KASAN_TAG_MASK ((1UL << KASAN_TAG_WIDTH) - 1) 1118 #define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1) 1119 page_zonenum(const struct page * page)1120 static inline enum zone_type page_zonenum(const struct page *page) 1121 { 1122 ASSERT_EXCLUSIVE_BITS(page->flags, ZONES_MASK << ZONES_PGSHIFT); 1123 return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK; 1124 } 1125 folio_zonenum(const struct folio * folio)1126 static inline enum zone_type folio_zonenum(const struct folio *folio) 1127 { 1128 return page_zonenum(&folio->page); 1129 } 1130 1131 #ifdef CONFIG_ZONE_DEVICE is_zone_device_page(const struct page * page)1132 static inline bool is_zone_device_page(const struct page *page) 1133 { 1134 return page_zonenum(page) == ZONE_DEVICE; 1135 } 1136 1137 /* 1138 * Consecutive zone device pages should not be merged into the same sgl 1139 * or bvec segment with other types of pages or if they belong to different 1140 * pgmaps. Otherwise getting the pgmap of a given segment is not possible 1141 * without scanning the entire segment. This helper returns true either if 1142 * both pages are not zone device pages or both pages are zone device pages 1143 * with the same pgmap. 1144 */ zone_device_pages_have_same_pgmap(const struct page * a,const struct page * b)1145 static inline bool zone_device_pages_have_same_pgmap(const struct page *a, 1146 const struct page *b) 1147 { 1148 if (is_zone_device_page(a) != is_zone_device_page(b)) 1149 return false; 1150 if (!is_zone_device_page(a)) 1151 return true; 1152 return a->pgmap == b->pgmap; 1153 } 1154 1155 extern void memmap_init_zone_device(struct zone *, unsigned long, 1156 unsigned long, struct dev_pagemap *); 1157 #else is_zone_device_page(const struct page * page)1158 static inline bool is_zone_device_page(const struct page *page) 1159 { 1160 return false; 1161 } zone_device_pages_have_same_pgmap(const struct page * a,const struct page * b)1162 static inline bool zone_device_pages_have_same_pgmap(const struct page *a, 1163 const struct page *b) 1164 { 1165 return true; 1166 } 1167 #endif 1168 folio_is_zone_device(const struct folio * folio)1169 static inline bool folio_is_zone_device(const struct folio *folio) 1170 { 1171 return is_zone_device_page(&folio->page); 1172 } 1173 is_zone_movable_page(const struct page * page)1174 static inline bool is_zone_movable_page(const struct page *page) 1175 { 1176 return page_zonenum(page) == ZONE_MOVABLE; 1177 } 1178 folio_is_zone_movable(const struct folio * folio)1179 static inline bool folio_is_zone_movable(const struct folio *folio) 1180 { 1181 return folio_zonenum(folio) == ZONE_MOVABLE; 1182 } 1183 #endif 1184 1185 /* 1186 * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty 1187 * intersection with the given zone 1188 */ zone_intersects(struct zone * zone,unsigned long start_pfn,unsigned long nr_pages)1189 static inline bool zone_intersects(struct zone *zone, 1190 unsigned long start_pfn, unsigned long nr_pages) 1191 { 1192 if (zone_is_empty(zone)) 1193 return false; 1194 if (start_pfn >= zone_end_pfn(zone) || 1195 start_pfn + nr_pages <= zone->zone_start_pfn) 1196 return false; 1197 1198 return true; 1199 } 1200 1201 /* 1202 * The "priority" of VM scanning is how much of the queues we will scan in one 1203 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the 1204 * queues ("queue_length >> 12") during an aging round. 1205 */ 1206 #define DEF_PRIORITY 12 1207 1208 /* Maximum number of zones on a zonelist */ 1209 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES) 1210 1211 enum { 1212 ZONELIST_FALLBACK, /* zonelist with fallback */ 1213 #ifdef CONFIG_NUMA 1214 /* 1215 * The NUMA zonelists are doubled because we need zonelists that 1216 * restrict the allocations to a single node for __GFP_THISNODE. 1217 */ 1218 ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */ 1219 #endif 1220 MAX_ZONELISTS 1221 }; 1222 1223 /* 1224 * This struct contains information about a zone in a zonelist. It is stored 1225 * here to avoid dereferences into large structures and lookups of tables 1226 */ 1227 struct zoneref { 1228 struct zone *zone; /* Pointer to actual zone */ 1229 int zone_idx; /* zone_idx(zoneref->zone) */ 1230 }; 1231 1232 /* 1233 * One allocation request operates on a zonelist. A zonelist 1234 * is a list of zones, the first one is the 'goal' of the 1235 * allocation, the other zones are fallback zones, in decreasing 1236 * priority. 1237 * 1238 * To speed the reading of the zonelist, the zonerefs contain the zone index 1239 * of the entry being read. Helper functions to access information given 1240 * a struct zoneref are 1241 * 1242 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs 1243 * zonelist_zone_idx() - Return the index of the zone for an entry 1244 * zonelist_node_idx() - Return the index of the node for an entry 1245 */ 1246 struct zonelist { 1247 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1]; 1248 }; 1249 1250 /* 1251 * The array of struct pages for flatmem. 1252 * It must be declared for SPARSEMEM as well because there are configurations 1253 * that rely on that. 1254 */ 1255 extern struct page *mem_map; 1256 1257 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 1258 struct deferred_split { 1259 spinlock_t split_queue_lock; 1260 struct list_head split_queue; 1261 unsigned long split_queue_len; 1262 }; 1263 #endif 1264 1265 #ifdef CONFIG_MEMORY_FAILURE 1266 /* 1267 * Per NUMA node memory failure handling statistics. 1268 */ 1269 struct memory_failure_stats { 1270 /* 1271 * Number of raw pages poisoned. 1272 * Cases not accounted: memory outside kernel control, offline page, 1273 * arch-specific memory_failure (SGX), hwpoison_filter() filtered 1274 * error events, and unpoison actions from hwpoison_unpoison. 1275 */ 1276 unsigned long total; 1277 /* 1278 * Recovery results of poisoned raw pages handled by memory_failure, 1279 * in sync with mf_result. 1280 * total = ignored + failed + delayed + recovered. 1281 * total * PAGE_SIZE * #nodes = /proc/meminfo/HardwareCorrupted. 1282 */ 1283 unsigned long ignored; 1284 unsigned long failed; 1285 unsigned long delayed; 1286 unsigned long recovered; 1287 }; 1288 #endif 1289 1290 /* 1291 * On NUMA machines, each NUMA node would have a pg_data_t to describe 1292 * it's memory layout. On UMA machines there is a single pglist_data which 1293 * describes the whole memory. 1294 * 1295 * Memory statistics and page replacement data structures are maintained on a 1296 * per-zone basis. 1297 */ 1298 typedef struct pglist_data { 1299 /* 1300 * node_zones contains just the zones for THIS node. Not all of the 1301 * zones may be populated, but it is the full list. It is referenced by 1302 * this node's node_zonelists as well as other node's node_zonelists. 1303 */ 1304 struct zone node_zones[MAX_NR_ZONES]; 1305 1306 /* 1307 * node_zonelists contains references to all zones in all nodes. 1308 * Generally the first zones will be references to this node's 1309 * node_zones. 1310 */ 1311 struct zonelist node_zonelists[MAX_ZONELISTS]; 1312 1313 int nr_zones; /* number of populated zones in this node */ 1314 #ifdef CONFIG_FLATMEM /* means !SPARSEMEM */ 1315 struct page *node_mem_map; 1316 #ifdef CONFIG_PAGE_EXTENSION 1317 struct page_ext *node_page_ext; 1318 #endif 1319 #endif 1320 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT) 1321 /* 1322 * Must be held any time you expect node_start_pfn, 1323 * node_present_pages, node_spanned_pages or nr_zones to stay constant. 1324 * Also synchronizes pgdat->first_deferred_pfn during deferred page 1325 * init. 1326 * 1327 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to 1328 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG 1329 * or CONFIG_DEFERRED_STRUCT_PAGE_INIT. 1330 * 1331 * Nests above zone->lock and zone->span_seqlock 1332 */ 1333 spinlock_t node_size_lock; 1334 #endif 1335 unsigned long node_start_pfn; 1336 unsigned long node_present_pages; /* total number of physical pages */ 1337 unsigned long node_spanned_pages; /* total size of physical page 1338 range, including holes */ 1339 int node_id; 1340 wait_queue_head_t kswapd_wait; 1341 wait_queue_head_t pfmemalloc_wait; 1342 1343 /* workqueues for throttling reclaim for different reasons. */ 1344 wait_queue_head_t reclaim_wait[NR_VMSCAN_THROTTLE]; 1345 1346 atomic_t nr_writeback_throttled;/* nr of writeback-throttled tasks */ 1347 unsigned long nr_reclaim_start; /* nr pages written while throttled 1348 * when throttling started. */ 1349 #ifdef CONFIG_MEMORY_HOTPLUG 1350 struct mutex kswapd_lock; 1351 #endif 1352 struct task_struct *kswapd; /* Protected by kswapd_lock */ 1353 int kswapd_order; 1354 enum zone_type kswapd_highest_zoneidx; 1355 1356 int kswapd_failures; /* Number of 'reclaimed == 0' runs */ 1357 1358 #ifdef CONFIG_COMPACTION 1359 int kcompactd_max_order; 1360 enum zone_type kcompactd_highest_zoneidx; 1361 wait_queue_head_t kcompactd_wait; 1362 struct task_struct *kcompactd; 1363 bool proactive_compact_trigger; 1364 #endif 1365 /* 1366 * This is a per-node reserve of pages that are not available 1367 * to userspace allocations. 1368 */ 1369 unsigned long totalreserve_pages; 1370 1371 #ifdef CONFIG_NUMA 1372 /* 1373 * node reclaim becomes active if more unmapped pages exist. 1374 */ 1375 unsigned long min_unmapped_pages; 1376 unsigned long min_slab_pages; 1377 #endif /* CONFIG_NUMA */ 1378 1379 /* Write-intensive fields used by page reclaim */ 1380 CACHELINE_PADDING(_pad1_); 1381 1382 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 1383 /* 1384 * If memory initialisation on large machines is deferred then this 1385 * is the first PFN that needs to be initialised. 1386 */ 1387 unsigned long first_deferred_pfn; 1388 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ 1389 1390 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 1391 struct deferred_split deferred_split_queue; 1392 #endif 1393 1394 #ifdef CONFIG_NUMA_BALANCING 1395 /* start time in ms of current promote rate limit period */ 1396 unsigned int nbp_rl_start; 1397 /* number of promote candidate pages at start time of current rate limit period */ 1398 unsigned long nbp_rl_nr_cand; 1399 /* promote threshold in ms */ 1400 unsigned int nbp_threshold; 1401 /* start time in ms of current promote threshold adjustment period */ 1402 unsigned int nbp_th_start; 1403 /* 1404 * number of promote candidate pages at start time of current promote 1405 * threshold adjustment period 1406 */ 1407 unsigned long nbp_th_nr_cand; 1408 #endif 1409 /* Fields commonly accessed by the page reclaim scanner */ 1410 1411 /* 1412 * NOTE: THIS IS UNUSED IF MEMCG IS ENABLED. 1413 * 1414 * Use mem_cgroup_lruvec() to look up lruvecs. 1415 */ 1416 struct lruvec __lruvec; 1417 1418 unsigned long flags; 1419 1420 #ifdef CONFIG_LRU_GEN 1421 /* kswap mm walk data */ 1422 struct lru_gen_mm_walk mm_walk; 1423 /* lru_gen_folio list */ 1424 struct lru_gen_memcg memcg_lru; 1425 #endif 1426 1427 CACHELINE_PADDING(_pad2_); 1428 1429 /* Per-node vmstats */ 1430 struct per_cpu_nodestat __percpu *per_cpu_nodestats; 1431 atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS]; 1432 #ifdef CONFIG_NUMA 1433 struct memory_tier __rcu *memtier; 1434 #endif 1435 #ifdef CONFIG_MEMORY_FAILURE 1436 struct memory_failure_stats mf_stats; 1437 #endif 1438 } pg_data_t; 1439 1440 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages) 1441 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages) 1442 1443 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) 1444 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid)) 1445 pgdat_end_pfn(pg_data_t * pgdat)1446 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat) 1447 { 1448 return pgdat->node_start_pfn + pgdat->node_spanned_pages; 1449 } 1450 1451 #include <linux/memory_hotplug.h> 1452 1453 void build_all_zonelists(pg_data_t *pgdat); 1454 void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order, 1455 enum zone_type highest_zoneidx); 1456 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, 1457 int highest_zoneidx, unsigned int alloc_flags, 1458 long free_pages); 1459 bool zone_watermark_ok(struct zone *z, unsigned int order, 1460 unsigned long mark, int highest_zoneidx, 1461 unsigned int alloc_flags); 1462 bool zone_watermark_ok_safe(struct zone *z, unsigned int order, 1463 unsigned long mark, int highest_zoneidx); 1464 /* 1465 * Memory initialization context, use to differentiate memory added by 1466 * the platform statically or via memory hotplug interface. 1467 */ 1468 enum meminit_context { 1469 MEMINIT_EARLY, 1470 MEMINIT_HOTPLUG, 1471 }; 1472 1473 extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn, 1474 unsigned long size); 1475 1476 extern void lruvec_init(struct lruvec *lruvec); 1477 lruvec_pgdat(struct lruvec * lruvec)1478 static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec) 1479 { 1480 #ifdef CONFIG_MEMCG 1481 return lruvec->pgdat; 1482 #else 1483 return container_of(lruvec, struct pglist_data, __lruvec); 1484 #endif 1485 } 1486 1487 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 1488 int local_memory_node(int node_id); 1489 #else local_memory_node(int node_id)1490 static inline int local_memory_node(int node_id) { return node_id; }; 1491 #endif 1492 1493 /* 1494 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc. 1495 */ 1496 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones) 1497 1498 #ifdef CONFIG_ZONE_DEVICE zone_is_zone_device(struct zone * zone)1499 static inline bool zone_is_zone_device(struct zone *zone) 1500 { 1501 return zone_idx(zone) == ZONE_DEVICE; 1502 } 1503 #else zone_is_zone_device(struct zone * zone)1504 static inline bool zone_is_zone_device(struct zone *zone) 1505 { 1506 return false; 1507 } 1508 #endif 1509 1510 /* 1511 * Returns true if a zone has pages managed by the buddy allocator. 1512 * All the reclaim decisions have to use this function rather than 1513 * populated_zone(). If the whole zone is reserved then we can easily 1514 * end up with populated_zone() && !managed_zone(). 1515 */ managed_zone(struct zone * zone)1516 static inline bool managed_zone(struct zone *zone) 1517 { 1518 return zone_managed_pages(zone); 1519 } 1520 1521 /* Returns true if a zone has memory */ populated_zone(struct zone * zone)1522 static inline bool populated_zone(struct zone *zone) 1523 { 1524 return zone->present_pages; 1525 } 1526 1527 #ifdef CONFIG_NUMA zone_to_nid(struct zone * zone)1528 static inline int zone_to_nid(struct zone *zone) 1529 { 1530 return zone->node; 1531 } 1532 zone_set_nid(struct zone * zone,int nid)1533 static inline void zone_set_nid(struct zone *zone, int nid) 1534 { 1535 zone->node = nid; 1536 } 1537 #else zone_to_nid(struct zone * zone)1538 static inline int zone_to_nid(struct zone *zone) 1539 { 1540 return 0; 1541 } 1542 zone_set_nid(struct zone * zone,int nid)1543 static inline void zone_set_nid(struct zone *zone, int nid) {} 1544 #endif 1545 1546 extern int movable_zone; 1547 is_highmem_idx(enum zone_type idx)1548 static inline int is_highmem_idx(enum zone_type idx) 1549 { 1550 #ifdef CONFIG_HIGHMEM 1551 return (idx == ZONE_HIGHMEM || 1552 (idx == ZONE_MOVABLE && movable_zone == ZONE_HIGHMEM)); 1553 #else 1554 return 0; 1555 #endif 1556 } 1557 1558 /** 1559 * is_highmem - helper function to quickly check if a struct zone is a 1560 * highmem zone or not. This is an attempt to keep references 1561 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum. 1562 * @zone: pointer to struct zone variable 1563 * Return: 1 for a highmem zone, 0 otherwise 1564 */ is_highmem(struct zone * zone)1565 static inline int is_highmem(struct zone *zone) 1566 { 1567 return is_highmem_idx(zone_idx(zone)); 1568 } 1569 1570 #ifdef CONFIG_ZONE_DMA 1571 bool has_managed_dma(void); 1572 #else has_managed_dma(void)1573 static inline bool has_managed_dma(void) 1574 { 1575 return false; 1576 } 1577 #endif 1578 1579 1580 #ifndef CONFIG_NUMA 1581 1582 extern struct pglist_data contig_page_data; NODE_DATA(int nid)1583 static inline struct pglist_data *NODE_DATA(int nid) 1584 { 1585 return &contig_page_data; 1586 } 1587 1588 #else /* CONFIG_NUMA */ 1589 1590 #include <asm/mmzone.h> 1591 1592 #endif /* !CONFIG_NUMA */ 1593 1594 extern struct pglist_data *first_online_pgdat(void); 1595 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat); 1596 extern struct zone *next_zone(struct zone *zone); 1597 1598 /** 1599 * for_each_online_pgdat - helper macro to iterate over all online nodes 1600 * @pgdat: pointer to a pg_data_t variable 1601 */ 1602 #define for_each_online_pgdat(pgdat) \ 1603 for (pgdat = first_online_pgdat(); \ 1604 pgdat; \ 1605 pgdat = next_online_pgdat(pgdat)) 1606 /** 1607 * for_each_zone - helper macro to iterate over all memory zones 1608 * @zone: pointer to struct zone variable 1609 * 1610 * The user only needs to declare the zone variable, for_each_zone 1611 * fills it in. 1612 */ 1613 #define for_each_zone(zone) \ 1614 for (zone = (first_online_pgdat())->node_zones; \ 1615 zone; \ 1616 zone = next_zone(zone)) 1617 1618 #define for_each_populated_zone(zone) \ 1619 for (zone = (first_online_pgdat())->node_zones; \ 1620 zone; \ 1621 zone = next_zone(zone)) \ 1622 if (!populated_zone(zone)) \ 1623 ; /* do nothing */ \ 1624 else 1625 zonelist_zone(struct zoneref * zoneref)1626 static inline struct zone *zonelist_zone(struct zoneref *zoneref) 1627 { 1628 return zoneref->zone; 1629 } 1630 zonelist_zone_idx(struct zoneref * zoneref)1631 static inline int zonelist_zone_idx(struct zoneref *zoneref) 1632 { 1633 return zoneref->zone_idx; 1634 } 1635 zonelist_node_idx(struct zoneref * zoneref)1636 static inline int zonelist_node_idx(struct zoneref *zoneref) 1637 { 1638 return zone_to_nid(zoneref->zone); 1639 } 1640 1641 struct zoneref *__next_zones_zonelist(struct zoneref *z, 1642 enum zone_type highest_zoneidx, 1643 nodemask_t *nodes); 1644 1645 /** 1646 * 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 1647 * @z: The cursor used as a starting point for the search 1648 * @highest_zoneidx: The zone index of the highest zone to return 1649 * @nodes: An optional nodemask to filter the zonelist with 1650 * 1651 * This function returns the next zone at or below a given zone index that is 1652 * within the allowed nodemask using a cursor as the starting point for the 1653 * search. The zoneref returned is a cursor that represents the current zone 1654 * being examined. It should be advanced by one before calling 1655 * next_zones_zonelist again. 1656 * 1657 * Return: the next zone at or below highest_zoneidx within the allowed 1658 * nodemask using a cursor within a zonelist as a starting point 1659 */ next_zones_zonelist(struct zoneref * z,enum zone_type highest_zoneidx,nodemask_t * nodes)1660 static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z, 1661 enum zone_type highest_zoneidx, 1662 nodemask_t *nodes) 1663 { 1664 if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx)) 1665 return z; 1666 return __next_zones_zonelist(z, highest_zoneidx, nodes); 1667 } 1668 1669 /** 1670 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist 1671 * @zonelist: The zonelist to search for a suitable zone 1672 * @highest_zoneidx: The zone index of the highest zone to return 1673 * @nodes: An optional nodemask to filter the zonelist with 1674 * 1675 * This function returns the first zone at or below a given zone index that is 1676 * within the allowed nodemask. The zoneref returned is a cursor that can be 1677 * used to iterate the zonelist with next_zones_zonelist by advancing it by 1678 * one before calling. 1679 * 1680 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is 1681 * never NULL). This may happen either genuinely, or due to concurrent nodemask 1682 * update due to cpuset modification. 1683 * 1684 * Return: Zoneref pointer for the first suitable zone found 1685 */ first_zones_zonelist(struct zonelist * zonelist,enum zone_type highest_zoneidx,nodemask_t * nodes)1686 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist, 1687 enum zone_type highest_zoneidx, 1688 nodemask_t *nodes) 1689 { 1690 return next_zones_zonelist(zonelist->_zonerefs, 1691 highest_zoneidx, nodes); 1692 } 1693 1694 /** 1695 * 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 1696 * @zone: The current zone in the iterator 1697 * @z: The current pointer within zonelist->_zonerefs being iterated 1698 * @zlist: The zonelist being iterated 1699 * @highidx: The zone index of the highest zone to return 1700 * @nodemask: Nodemask allowed by the allocator 1701 * 1702 * This iterator iterates though all zones at or below a given zone index and 1703 * within a given nodemask 1704 */ 1705 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \ 1706 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \ 1707 zone; \ 1708 z = next_zones_zonelist(++z, highidx, nodemask), \ 1709 zone = zonelist_zone(z)) 1710 1711 #define for_next_zone_zonelist_nodemask(zone, z, highidx, nodemask) \ 1712 for (zone = zonelist_zone(z); \ 1713 zone; \ 1714 z = next_zones_zonelist(++z, highidx, nodemask), \ 1715 zone = zonelist_zone(z)) 1716 1717 1718 /** 1719 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index 1720 * @zone: The current zone in the iterator 1721 * @z: The current pointer within zonelist->zones being iterated 1722 * @zlist: The zonelist being iterated 1723 * @highidx: The zone index of the highest zone to return 1724 * 1725 * This iterator iterates though all zones at or below a given zone index. 1726 */ 1727 #define for_each_zone_zonelist(zone, z, zlist, highidx) \ 1728 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL) 1729 1730 /* Whether the 'nodes' are all movable nodes */ movable_only_nodes(nodemask_t * nodes)1731 static inline bool movable_only_nodes(nodemask_t *nodes) 1732 { 1733 struct zonelist *zonelist; 1734 struct zoneref *z; 1735 int nid; 1736 1737 if (nodes_empty(*nodes)) 1738 return false; 1739 1740 /* 1741 * We can chose arbitrary node from the nodemask to get a 1742 * zonelist as they are interlinked. We just need to find 1743 * at least one zone that can satisfy kernel allocations. 1744 */ 1745 nid = first_node(*nodes); 1746 zonelist = &NODE_DATA(nid)->node_zonelists[ZONELIST_FALLBACK]; 1747 z = first_zones_zonelist(zonelist, ZONE_NORMAL, nodes); 1748 return (!zonelist_zone(z)) ? true : false; 1749 } 1750 1751 1752 #ifdef CONFIG_SPARSEMEM 1753 #include <asm/sparsemem.h> 1754 #endif 1755 1756 #ifdef CONFIG_FLATMEM 1757 #define pfn_to_nid(pfn) (0) 1758 #endif 1759 1760 #ifdef CONFIG_SPARSEMEM 1761 1762 /* 1763 * PA_SECTION_SHIFT physical address to/from section number 1764 * PFN_SECTION_SHIFT pfn to/from section number 1765 */ 1766 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS) 1767 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT) 1768 1769 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT) 1770 1771 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT) 1772 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1)) 1773 1774 #define SECTION_BLOCKFLAGS_BITS \ 1775 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS) 1776 1777 #if (MAX_PAGE_ORDER + PAGE_SHIFT) > SECTION_SIZE_BITS 1778 #error Allocator MAX_PAGE_ORDER exceeds SECTION_SIZE 1779 #endif 1780 pfn_to_section_nr(unsigned long pfn)1781 static inline unsigned long pfn_to_section_nr(unsigned long pfn) 1782 { 1783 return pfn >> PFN_SECTION_SHIFT; 1784 } section_nr_to_pfn(unsigned long sec)1785 static inline unsigned long section_nr_to_pfn(unsigned long sec) 1786 { 1787 return sec << PFN_SECTION_SHIFT; 1788 } 1789 1790 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK) 1791 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK) 1792 1793 #define SUBSECTION_SHIFT 21 1794 #define SUBSECTION_SIZE (1UL << SUBSECTION_SHIFT) 1795 1796 #define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT) 1797 #define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT) 1798 #define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1)) 1799 1800 #if SUBSECTION_SHIFT > SECTION_SIZE_BITS 1801 #error Subsection size exceeds section size 1802 #else 1803 #define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT)) 1804 #endif 1805 1806 #define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION) 1807 #define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK) 1808 1809 struct mem_section_usage { 1810 struct rcu_head rcu; 1811 #ifdef CONFIG_SPARSEMEM_VMEMMAP 1812 DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION); 1813 #endif 1814 /* See declaration of similar field in struct zone */ 1815 unsigned long pageblock_flags[0]; 1816 }; 1817 1818 void subsection_map_init(unsigned long pfn, unsigned long nr_pages); 1819 1820 struct page; 1821 struct page_ext; 1822 struct mem_section { 1823 /* 1824 * This is, logically, a pointer to an array of struct 1825 * pages. However, it is stored with some other magic. 1826 * (see sparse.c::sparse_init_one_section()) 1827 * 1828 * Additionally during early boot we encode node id of 1829 * the location of the section here to guide allocation. 1830 * (see sparse.c::memory_present()) 1831 * 1832 * Making it a UL at least makes someone do a cast 1833 * before using it wrong. 1834 */ 1835 unsigned long section_mem_map; 1836 1837 struct mem_section_usage *usage; 1838 #ifdef CONFIG_PAGE_EXTENSION 1839 /* 1840 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use 1841 * section. (see page_ext.h about this.) 1842 */ 1843 struct page_ext *page_ext; 1844 unsigned long pad; 1845 #endif 1846 /* 1847 * WARNING: mem_section must be a power-of-2 in size for the 1848 * calculation and use of SECTION_ROOT_MASK to make sense. 1849 */ 1850 }; 1851 1852 #ifdef CONFIG_SPARSEMEM_EXTREME 1853 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section)) 1854 #else 1855 #define SECTIONS_PER_ROOT 1 1856 #endif 1857 1858 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT) 1859 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT) 1860 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1) 1861 1862 #ifdef CONFIG_SPARSEMEM_EXTREME 1863 extern struct mem_section **mem_section; 1864 #else 1865 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; 1866 #endif 1867 section_to_usemap(struct mem_section * ms)1868 static inline unsigned long *section_to_usemap(struct mem_section *ms) 1869 { 1870 return ms->usage->pageblock_flags; 1871 } 1872 __nr_to_section(unsigned long nr)1873 static inline struct mem_section *__nr_to_section(unsigned long nr) 1874 { 1875 unsigned long root = SECTION_NR_TO_ROOT(nr); 1876 1877 if (unlikely(root >= NR_SECTION_ROOTS)) 1878 return NULL; 1879 1880 #ifdef CONFIG_SPARSEMEM_EXTREME 1881 if (!mem_section || !mem_section[root]) 1882 return NULL; 1883 #endif 1884 return &mem_section[root][nr & SECTION_ROOT_MASK]; 1885 } 1886 extern size_t mem_section_usage_size(void); 1887 1888 /* 1889 * We use the lower bits of the mem_map pointer to store 1890 * a little bit of information. The pointer is calculated 1891 * as mem_map - section_nr_to_pfn(pnum). The result is 1892 * aligned to the minimum alignment of the two values: 1893 * 1. All mem_map arrays are page-aligned. 1894 * 2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT 1895 * lowest bits. PFN_SECTION_SHIFT is arch-specific 1896 * (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the 1897 * worst combination is powerpc with 256k pages, 1898 * which results in PFN_SECTION_SHIFT equal 6. 1899 * To sum it up, at least 6 bits are available on all architectures. 1900 * However, we can exceed 6 bits on some other architectures except 1901 * powerpc (e.g. 15 bits are available on x86_64, 13 bits are available 1902 * with the worst case of 64K pages on arm64) if we make sure the 1903 * exceeded bit is not applicable to powerpc. 1904 */ 1905 enum { 1906 SECTION_MARKED_PRESENT_BIT, 1907 SECTION_HAS_MEM_MAP_BIT, 1908 SECTION_IS_ONLINE_BIT, 1909 SECTION_IS_EARLY_BIT, 1910 #ifdef CONFIG_ZONE_DEVICE 1911 SECTION_TAINT_ZONE_DEVICE_BIT, 1912 #endif 1913 SECTION_MAP_LAST_BIT, 1914 }; 1915 1916 #define SECTION_MARKED_PRESENT BIT(SECTION_MARKED_PRESENT_BIT) 1917 #define SECTION_HAS_MEM_MAP BIT(SECTION_HAS_MEM_MAP_BIT) 1918 #define SECTION_IS_ONLINE BIT(SECTION_IS_ONLINE_BIT) 1919 #define SECTION_IS_EARLY BIT(SECTION_IS_EARLY_BIT) 1920 #ifdef CONFIG_ZONE_DEVICE 1921 #define SECTION_TAINT_ZONE_DEVICE BIT(SECTION_TAINT_ZONE_DEVICE_BIT) 1922 #endif 1923 #define SECTION_MAP_MASK (~(BIT(SECTION_MAP_LAST_BIT) - 1)) 1924 #define SECTION_NID_SHIFT SECTION_MAP_LAST_BIT 1925 __section_mem_map_addr(struct mem_section * section)1926 static inline struct page *__section_mem_map_addr(struct mem_section *section) 1927 { 1928 unsigned long map = section->section_mem_map; 1929 map &= SECTION_MAP_MASK; 1930 return (struct page *)map; 1931 } 1932 present_section(struct mem_section * section)1933 static inline int present_section(struct mem_section *section) 1934 { 1935 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT)); 1936 } 1937 present_section_nr(unsigned long nr)1938 static inline int present_section_nr(unsigned long nr) 1939 { 1940 return present_section(__nr_to_section(nr)); 1941 } 1942 valid_section(struct mem_section * section)1943 static inline int valid_section(struct mem_section *section) 1944 { 1945 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP)); 1946 } 1947 early_section(struct mem_section * section)1948 static inline int early_section(struct mem_section *section) 1949 { 1950 return (section && (section->section_mem_map & SECTION_IS_EARLY)); 1951 } 1952 valid_section_nr(unsigned long nr)1953 static inline int valid_section_nr(unsigned long nr) 1954 { 1955 return valid_section(__nr_to_section(nr)); 1956 } 1957 online_section(struct mem_section * section)1958 static inline int online_section(struct mem_section *section) 1959 { 1960 return (section && (section->section_mem_map & SECTION_IS_ONLINE)); 1961 } 1962 1963 #ifdef CONFIG_ZONE_DEVICE online_device_section(struct mem_section * section)1964 static inline int online_device_section(struct mem_section *section) 1965 { 1966 unsigned long flags = SECTION_IS_ONLINE | SECTION_TAINT_ZONE_DEVICE; 1967 1968 return section && ((section->section_mem_map & flags) == flags); 1969 } 1970 #else online_device_section(struct mem_section * section)1971 static inline int online_device_section(struct mem_section *section) 1972 { 1973 return 0; 1974 } 1975 #endif 1976 online_section_nr(unsigned long nr)1977 static inline int online_section_nr(unsigned long nr) 1978 { 1979 return online_section(__nr_to_section(nr)); 1980 } 1981 1982 #ifdef CONFIG_MEMORY_HOTPLUG 1983 void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn); 1984 void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn); 1985 #endif 1986 __pfn_to_section(unsigned long pfn)1987 static inline struct mem_section *__pfn_to_section(unsigned long pfn) 1988 { 1989 return __nr_to_section(pfn_to_section_nr(pfn)); 1990 } 1991 1992 extern unsigned long __highest_present_section_nr; 1993 subsection_map_index(unsigned long pfn)1994 static inline int subsection_map_index(unsigned long pfn) 1995 { 1996 return (pfn & ~(PAGE_SECTION_MASK)) / PAGES_PER_SUBSECTION; 1997 } 1998 1999 #ifdef CONFIG_SPARSEMEM_VMEMMAP pfn_section_valid(struct mem_section * ms,unsigned long pfn)2000 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn) 2001 { 2002 int idx = subsection_map_index(pfn); 2003 struct mem_section_usage *usage = READ_ONCE(ms->usage); 2004 2005 return usage ? test_bit(idx, usage->subsection_map) : 0; 2006 } 2007 #else pfn_section_valid(struct mem_section * ms,unsigned long pfn)2008 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn) 2009 { 2010 return 1; 2011 } 2012 #endif 2013 2014 #ifndef CONFIG_HAVE_ARCH_PFN_VALID 2015 /** 2016 * pfn_valid - check if there is a valid memory map entry for a PFN 2017 * @pfn: the page frame number to check 2018 * 2019 * Check if there is a valid memory map entry aka struct page for the @pfn. 2020 * Note, that availability of the memory map entry does not imply that 2021 * there is actual usable memory at that @pfn. The struct page may 2022 * represent a hole or an unusable page frame. 2023 * 2024 * Return: 1 for PFNs that have memory map entries and 0 otherwise 2025 */ pfn_valid(unsigned long pfn)2026 static inline int pfn_valid(unsigned long pfn) 2027 { 2028 struct mem_section *ms; 2029 int ret; 2030 2031 /* 2032 * Ensure the upper PAGE_SHIFT bits are clear in the 2033 * pfn. Else it might lead to false positives when 2034 * some of the upper bits are set, but the lower bits 2035 * match a valid pfn. 2036 */ 2037 if (PHYS_PFN(PFN_PHYS(pfn)) != pfn) 2038 return 0; 2039 2040 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 2041 return 0; 2042 ms = __pfn_to_section(pfn); 2043 rcu_read_lock_sched(); 2044 if (!valid_section(ms)) { 2045 rcu_read_unlock_sched(); 2046 return 0; 2047 } 2048 /* 2049 * Traditionally early sections always returned pfn_valid() for 2050 * the entire section-sized span. 2051 */ 2052 ret = early_section(ms) || pfn_section_valid(ms, pfn); 2053 rcu_read_unlock_sched(); 2054 2055 return ret; 2056 } 2057 #endif 2058 pfn_in_present_section(unsigned long pfn)2059 static inline int pfn_in_present_section(unsigned long pfn) 2060 { 2061 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 2062 return 0; 2063 return present_section(__pfn_to_section(pfn)); 2064 } 2065 next_present_section_nr(unsigned long section_nr)2066 static inline unsigned long next_present_section_nr(unsigned long section_nr) 2067 { 2068 while (++section_nr <= __highest_present_section_nr) { 2069 if (present_section_nr(section_nr)) 2070 return section_nr; 2071 } 2072 2073 return -1; 2074 } 2075 2076 /* 2077 * These are _only_ used during initialisation, therefore they 2078 * can use __initdata ... They could have names to indicate 2079 * this restriction. 2080 */ 2081 #ifdef CONFIG_NUMA 2082 #define pfn_to_nid(pfn) \ 2083 ({ \ 2084 unsigned long __pfn_to_nid_pfn = (pfn); \ 2085 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \ 2086 }) 2087 #else 2088 #define pfn_to_nid(pfn) (0) 2089 #endif 2090 2091 void sparse_init(void); 2092 #else 2093 #define sparse_init() do {} while (0) 2094 #define sparse_index_init(_sec, _nid) do {} while (0) 2095 #define pfn_in_present_section pfn_valid 2096 #define subsection_map_init(_pfn, _nr_pages) do {} while (0) 2097 #endif /* CONFIG_SPARSEMEM */ 2098 2099 #endif /* !__GENERATING_BOUNDS.H */ 2100 #endif /* !__ASSEMBLY__ */ 2101 #endif /* _LINUX_MMZONE_H */ 2102