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