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 plus one additional 359 * for pageblock size for THP if configured. 360 */ 361 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 362 #define NR_PCP_THP 1 363 #else 364 #define NR_PCP_THP 0 365 #endif 366 #define NR_PCP_LISTS (MIGRATE_PCPTYPES * (PAGE_ALLOC_COSTLY_ORDER + 1 + NR_PCP_THP)) 367 368 /* 369 * Shift to encode migratetype and order in the same integer, with order 370 * in the least significant bits. 371 */ 372 #define NR_PCP_ORDER_WIDTH 8 373 #define NR_PCP_ORDER_MASK ((1<<NR_PCP_ORDER_WIDTH) - 1) 374 375 #define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost) 376 #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost) 377 #define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost) 378 #define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost) 379 380 /* Fields and list protected by pagesets local_lock in page_alloc.c */ 381 struct per_cpu_pages { 382 int count; /* number of pages in the list */ 383 int high; /* high watermark, emptying needed */ 384 int batch; /* chunk size for buddy add/remove */ 385 short free_factor; /* batch scaling factor during free */ 386 #ifdef CONFIG_NUMA 387 short expire; /* When 0, remote pagesets are drained */ 388 #endif 389 390 /* Lists of pages, one per migrate type stored on the pcp-lists */ 391 struct list_head lists[NR_PCP_LISTS]; 392 }; 393 394 struct per_cpu_zonestat { 395 #ifdef CONFIG_SMP 396 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS]; 397 s8 stat_threshold; 398 #endif 399 #ifdef CONFIG_NUMA 400 /* 401 * Low priority inaccurate counters that are only folded 402 * on demand. Use a large type to avoid the overhead of 403 * folding during refresh_cpu_vm_stats. 404 */ 405 unsigned long vm_numa_event[NR_VM_NUMA_EVENT_ITEMS]; 406 #endif 407 }; 408 409 struct per_cpu_nodestat { 410 s8 stat_threshold; 411 s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS]; 412 }; 413 414 #endif /* !__GENERATING_BOUNDS.H */ 415 416 enum zone_type { 417 /* 418 * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able 419 * to DMA to all of the addressable memory (ZONE_NORMAL). 420 * On architectures where this area covers the whole 32 bit address 421 * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller 422 * DMA addressing constraints. This distinction is important as a 32bit 423 * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit 424 * platforms may need both zones as they support peripherals with 425 * different DMA addressing limitations. 426 */ 427 #ifdef CONFIG_ZONE_DMA 428 ZONE_DMA, 429 #endif 430 #ifdef CONFIG_ZONE_DMA32 431 ZONE_DMA32, 432 #endif 433 /* 434 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be 435 * performed on pages in ZONE_NORMAL if the DMA devices support 436 * transfers to all addressable memory. 437 */ 438 ZONE_NORMAL, 439 #ifdef CONFIG_HIGHMEM 440 /* 441 * A memory area that is only addressable by the kernel through 442 * mapping portions into its own address space. This is for example 443 * used by i386 to allow the kernel to address the memory beyond 444 * 900MB. The kernel will set up special mappings (page 445 * table entries on i386) for each page that the kernel needs to 446 * access. 447 */ 448 ZONE_HIGHMEM, 449 #endif 450 /* 451 * ZONE_MOVABLE is similar to ZONE_NORMAL, except that it contains 452 * movable pages with few exceptional cases described below. Main use 453 * cases for ZONE_MOVABLE are to make memory offlining/unplug more 454 * likely to succeed, and to locally limit unmovable allocations - e.g., 455 * to increase the number of THP/huge pages. Notable special cases are: 456 * 457 * 1. Pinned pages: (long-term) pinning of movable pages might 458 * essentially turn such pages unmovable. Therefore, we do not allow 459 * pinning long-term pages in ZONE_MOVABLE. When pages are pinned and 460 * faulted, they come from the right zone right away. However, it is 461 * still possible that address space already has pages in 462 * ZONE_MOVABLE at the time when pages are pinned (i.e. user has 463 * touches that memory before pinning). In such case we migrate them 464 * to a different zone. When migration fails - pinning fails. 465 * 2. memblock allocations: kernelcore/movablecore setups might create 466 * situations where ZONE_MOVABLE contains unmovable allocations 467 * after boot. Memory offlining and allocations fail early. 468 * 3. Memory holes: kernelcore/movablecore setups might create very rare 469 * situations where ZONE_MOVABLE contains memory holes after boot, 470 * for example, if we have sections that are only partially 471 * populated. Memory offlining and allocations fail early. 472 * 4. PG_hwpoison pages: while poisoned pages can be skipped during 473 * memory offlining, such pages cannot be allocated. 474 * 5. Unmovable PG_offline pages: in paravirtualized environments, 475 * hotplugged memory blocks might only partially be managed by the 476 * buddy (e.g., via XEN-balloon, Hyper-V balloon, virtio-mem). The 477 * parts not manged by the buddy are unmovable PG_offline pages. In 478 * some cases (virtio-mem), such pages can be skipped during 479 * memory offlining, however, cannot be moved/allocated. These 480 * techniques might use alloc_contig_range() to hide previously 481 * exposed pages from the buddy again (e.g., to implement some sort 482 * of memory unplug in virtio-mem). 483 * 6. ZERO_PAGE(0), kernelcore/movablecore setups might create 484 * situations where ZERO_PAGE(0) which is allocated differently 485 * on different platforms may end up in a movable zone. ZERO_PAGE(0) 486 * cannot be migrated. 487 * 7. Memory-hotplug: when using memmap_on_memory and onlining the 488 * memory to the MOVABLE zone, the vmemmap pages are also placed in 489 * such zone. Such pages cannot be really moved around as they are 490 * self-stored in the range, but they are treated as movable when 491 * the range they describe is about to be offlined. 492 * 493 * In general, no unmovable allocations that degrade memory offlining 494 * should end up in ZONE_MOVABLE. Allocators (like alloc_contig_range()) 495 * have to expect that migrating pages in ZONE_MOVABLE can fail (even 496 * if has_unmovable_pages() states that there are no unmovable pages, 497 * there can be false negatives). 498 */ 499 ZONE_MOVABLE, 500 #ifdef CONFIG_ZONE_DEVICE 501 ZONE_DEVICE, 502 #endif 503 __MAX_NR_ZONES 504 505 }; 506 507 #ifndef __GENERATING_BOUNDS_H 508 509 #define ASYNC_AND_SYNC 2 510 511 struct zone { 512 /* Read-mostly fields */ 513 514 /* zone watermarks, access with *_wmark_pages(zone) macros */ 515 unsigned long _watermark[NR_WMARK]; 516 unsigned long watermark_boost; 517 518 unsigned long nr_reserved_highatomic; 519 520 /* 521 * We don't know if the memory that we're going to allocate will be 522 * freeable or/and it will be released eventually, so to avoid totally 523 * wasting several GB of ram we must reserve some of the lower zone 524 * memory (otherwise we risk to run OOM on the lower zones despite 525 * there being tons of freeable ram on the higher zones). This array is 526 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl 527 * changes. 528 */ 529 long lowmem_reserve[MAX_NR_ZONES]; 530 531 #ifdef CONFIG_NUMA 532 int node; 533 #endif 534 struct pglist_data *zone_pgdat; 535 struct per_cpu_pages __percpu *per_cpu_pageset; 536 struct per_cpu_zonestat __percpu *per_cpu_zonestats; 537 /* 538 * the high and batch values are copied to individual pagesets for 539 * faster access 540 */ 541 int pageset_high; 542 int pageset_batch; 543 544 #ifndef CONFIG_SPARSEMEM 545 /* 546 * Flags for a pageblock_nr_pages block. See pageblock-flags.h. 547 * In SPARSEMEM, this map is stored in struct mem_section 548 */ 549 unsigned long *pageblock_flags; 550 #endif /* CONFIG_SPARSEMEM */ 551 552 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */ 553 unsigned long zone_start_pfn; 554 555 /* 556 * spanned_pages is the total pages spanned by the zone, including 557 * holes, which is calculated as: 558 * spanned_pages = zone_end_pfn - zone_start_pfn; 559 * 560 * present_pages is physical pages existing within the zone, which 561 * is calculated as: 562 * present_pages = spanned_pages - absent_pages(pages in holes); 563 * 564 * present_early_pages is present pages existing within the zone 565 * located on memory available since early boot, excluding hotplugged 566 * memory. 567 * 568 * managed_pages is present pages managed by the buddy system, which 569 * is calculated as (reserved_pages includes pages allocated by the 570 * bootmem allocator): 571 * managed_pages = present_pages - reserved_pages; 572 * 573 * cma pages is present pages that are assigned for CMA use 574 * (MIGRATE_CMA). 575 * 576 * So present_pages may be used by memory hotplug or memory power 577 * management logic to figure out unmanaged pages by checking 578 * (present_pages - managed_pages). And managed_pages should be used 579 * by page allocator and vm scanner to calculate all kinds of watermarks 580 * and thresholds. 581 * 582 * Locking rules: 583 * 584 * zone_start_pfn and spanned_pages are protected by span_seqlock. 585 * It is a seqlock because it has to be read outside of zone->lock, 586 * and it is done in the main allocator path. But, it is written 587 * quite infrequently. 588 * 589 * The span_seq lock is declared along with zone->lock because it is 590 * frequently read in proximity to zone->lock. It's good to 591 * give them a chance of being in the same cacheline. 592 * 593 * Write access to present_pages at runtime should be protected by 594 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of 595 * present_pages should get_online_mems() to get a stable value. 596 */ 597 atomic_long_t managed_pages; 598 unsigned long spanned_pages; 599 unsigned long present_pages; 600 #if defined(CONFIG_MEMORY_HOTPLUG) 601 unsigned long present_early_pages; 602 #endif 603 #ifdef CONFIG_CMA 604 unsigned long cma_pages; 605 #endif 606 607 const char *name; 608 609 #ifdef CONFIG_MEMORY_ISOLATION 610 /* 611 * Number of isolated pageblock. It is used to solve incorrect 612 * freepage counting problem due to racy retrieving migratetype 613 * of pageblock. Protected by zone->lock. 614 */ 615 unsigned long nr_isolate_pageblock; 616 #endif 617 618 #ifdef CONFIG_MEMORY_HOTPLUG 619 /* see spanned/present_pages for more description */ 620 seqlock_t span_seqlock; 621 #endif 622 623 int initialized; 624 625 /* Write-intensive fields used from the page allocator */ 626 ZONE_PADDING(_pad1_) 627 628 /* free areas of different sizes */ 629 struct free_area free_area[MAX_ORDER]; 630 631 /* zone flags, see below */ 632 unsigned long flags; 633 634 /* Primarily protects free_area */ 635 spinlock_t lock; 636 637 /* Write-intensive fields used by compaction and vmstats. */ 638 ZONE_PADDING(_pad2_) 639 640 /* 641 * When free pages are below this point, additional steps are taken 642 * when reading the number of free pages to avoid per-cpu counter 643 * drift allowing watermarks to be breached 644 */ 645 unsigned long percpu_drift_mark; 646 647 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 648 /* pfn where compaction free scanner should start */ 649 unsigned long compact_cached_free_pfn; 650 /* pfn where compaction migration scanner should start */ 651 unsigned long compact_cached_migrate_pfn[ASYNC_AND_SYNC]; 652 unsigned long compact_init_migrate_pfn; 653 unsigned long compact_init_free_pfn; 654 #endif 655 656 #ifdef CONFIG_COMPACTION 657 /* 658 * On compaction failure, 1<<compact_defer_shift compactions 659 * are skipped before trying again. The number attempted since 660 * last failure is tracked with compact_considered. 661 * compact_order_failed is the minimum compaction failed order. 662 */ 663 unsigned int compact_considered; 664 unsigned int compact_defer_shift; 665 int compact_order_failed; 666 #endif 667 668 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 669 /* Set to true when the PG_migrate_skip bits should be cleared */ 670 bool compact_blockskip_flush; 671 #endif 672 673 bool contiguous; 674 675 ZONE_PADDING(_pad3_) 676 /* Zone statistics */ 677 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; 678 atomic_long_t vm_numa_event[NR_VM_NUMA_EVENT_ITEMS]; 679 } ____cacheline_internodealigned_in_smp; 680 681 enum pgdat_flags { 682 PGDAT_DIRTY, /* reclaim scanning has recently found 683 * many dirty file pages at the tail 684 * of the LRU. 685 */ 686 PGDAT_WRITEBACK, /* reclaim scanning has recently found 687 * many pages under writeback 688 */ 689 PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */ 690 }; 691 692 enum zone_flags { 693 ZONE_BOOSTED_WATERMARK, /* zone recently boosted watermarks. 694 * Cleared when kswapd is woken. 695 */ 696 ZONE_RECLAIM_ACTIVE, /* kswapd may be scanning the zone. */ 697 }; 698 699 static inline unsigned long zone_managed_pages(struct zone *zone) 700 { 701 return (unsigned long)atomic_long_read(&zone->managed_pages); 702 } 703 704 static inline unsigned long zone_cma_pages(struct zone *zone) 705 { 706 #ifdef CONFIG_CMA 707 return zone->cma_pages; 708 #else 709 return 0; 710 #endif 711 } 712 713 static inline unsigned long zone_end_pfn(const struct zone *zone) 714 { 715 return zone->zone_start_pfn + zone->spanned_pages; 716 } 717 718 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn) 719 { 720 return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone); 721 } 722 723 static inline bool zone_is_initialized(struct zone *zone) 724 { 725 return zone->initialized; 726 } 727 728 static inline bool zone_is_empty(struct zone *zone) 729 { 730 return zone->spanned_pages == 0; 731 } 732 733 /* 734 * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty 735 * intersection with the given zone 736 */ 737 static inline bool zone_intersects(struct zone *zone, 738 unsigned long start_pfn, unsigned long nr_pages) 739 { 740 if (zone_is_empty(zone)) 741 return false; 742 if (start_pfn >= zone_end_pfn(zone) || 743 start_pfn + nr_pages <= zone->zone_start_pfn) 744 return false; 745 746 return true; 747 } 748 749 /* 750 * The "priority" of VM scanning is how much of the queues we will scan in one 751 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the 752 * queues ("queue_length >> 12") during an aging round. 753 */ 754 #define DEF_PRIORITY 12 755 756 /* Maximum number of zones on a zonelist */ 757 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES) 758 759 enum { 760 ZONELIST_FALLBACK, /* zonelist with fallback */ 761 #ifdef CONFIG_NUMA 762 /* 763 * The NUMA zonelists are doubled because we need zonelists that 764 * restrict the allocations to a single node for __GFP_THISNODE. 765 */ 766 ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */ 767 #endif 768 MAX_ZONELISTS 769 }; 770 771 /* 772 * This struct contains information about a zone in a zonelist. It is stored 773 * here to avoid dereferences into large structures and lookups of tables 774 */ 775 struct zoneref { 776 struct zone *zone; /* Pointer to actual zone */ 777 int zone_idx; /* zone_idx(zoneref->zone) */ 778 }; 779 780 /* 781 * One allocation request operates on a zonelist. A zonelist 782 * is a list of zones, the first one is the 'goal' of the 783 * allocation, the other zones are fallback zones, in decreasing 784 * priority. 785 * 786 * To speed the reading of the zonelist, the zonerefs contain the zone index 787 * of the entry being read. Helper functions to access information given 788 * a struct zoneref are 789 * 790 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs 791 * zonelist_zone_idx() - Return the index of the zone for an entry 792 * zonelist_node_idx() - Return the index of the node for an entry 793 */ 794 struct zonelist { 795 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1]; 796 }; 797 798 /* 799 * The array of struct pages for flatmem. 800 * It must be declared for SPARSEMEM as well because there are configurations 801 * that rely on that. 802 */ 803 extern struct page *mem_map; 804 805 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 806 struct deferred_split { 807 spinlock_t split_queue_lock; 808 struct list_head split_queue; 809 unsigned long split_queue_len; 810 }; 811 #endif 812 813 /* 814 * On NUMA machines, each NUMA node would have a pg_data_t to describe 815 * it's memory layout. On UMA machines there is a single pglist_data which 816 * describes the whole memory. 817 * 818 * Memory statistics and page replacement data structures are maintained on a 819 * per-zone basis. 820 */ 821 typedef struct pglist_data { 822 /* 823 * node_zones contains just the zones for THIS node. Not all of the 824 * zones may be populated, but it is the full list. It is referenced by 825 * this node's node_zonelists as well as other node's node_zonelists. 826 */ 827 struct zone node_zones[MAX_NR_ZONES]; 828 829 /* 830 * node_zonelists contains references to all zones in all nodes. 831 * Generally the first zones will be references to this node's 832 * node_zones. 833 */ 834 struct zonelist node_zonelists[MAX_ZONELISTS]; 835 836 int nr_zones; /* number of populated zones in this node */ 837 #ifdef CONFIG_FLATMEM /* means !SPARSEMEM */ 838 struct page *node_mem_map; 839 #ifdef CONFIG_PAGE_EXTENSION 840 struct page_ext *node_page_ext; 841 #endif 842 #endif 843 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT) 844 /* 845 * Must be held any time you expect node_start_pfn, 846 * node_present_pages, node_spanned_pages or nr_zones to stay constant. 847 * Also synchronizes pgdat->first_deferred_pfn during deferred page 848 * init. 849 * 850 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to 851 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG 852 * or CONFIG_DEFERRED_STRUCT_PAGE_INIT. 853 * 854 * Nests above zone->lock and zone->span_seqlock 855 */ 856 spinlock_t node_size_lock; 857 #endif 858 unsigned long node_start_pfn; 859 unsigned long node_present_pages; /* total number of physical pages */ 860 unsigned long node_spanned_pages; /* total size of physical page 861 range, including holes */ 862 int node_id; 863 wait_queue_head_t kswapd_wait; 864 wait_queue_head_t pfmemalloc_wait; 865 866 /* workqueues for throttling reclaim for different reasons. */ 867 wait_queue_head_t reclaim_wait[NR_VMSCAN_THROTTLE]; 868 869 atomic_t nr_writeback_throttled;/* nr of writeback-throttled tasks */ 870 unsigned long nr_reclaim_start; /* nr pages written while throttled 871 * when throttling started. */ 872 struct task_struct *kswapd; /* Protected by 873 mem_hotplug_begin/end() */ 874 int kswapd_order; 875 enum zone_type kswapd_highest_zoneidx; 876 877 int kswapd_failures; /* Number of 'reclaimed == 0' runs */ 878 879 #ifdef CONFIG_COMPACTION 880 int kcompactd_max_order; 881 enum zone_type kcompactd_highest_zoneidx; 882 wait_queue_head_t kcompactd_wait; 883 struct task_struct *kcompactd; 884 bool proactive_compact_trigger; 885 #endif 886 /* 887 * This is a per-node reserve of pages that are not available 888 * to userspace allocations. 889 */ 890 unsigned long totalreserve_pages; 891 892 #ifdef CONFIG_NUMA 893 /* 894 * node reclaim becomes active if more unmapped pages exist. 895 */ 896 unsigned long min_unmapped_pages; 897 unsigned long min_slab_pages; 898 #endif /* CONFIG_NUMA */ 899 900 /* Write-intensive fields used by page reclaim */ 901 ZONE_PADDING(_pad1_) 902 903 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 904 /* 905 * If memory initialisation on large machines is deferred then this 906 * is the first PFN that needs to be initialised. 907 */ 908 unsigned long first_deferred_pfn; 909 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ 910 911 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 912 struct deferred_split deferred_split_queue; 913 #endif 914 915 /* Fields commonly accessed by the page reclaim scanner */ 916 917 /* 918 * NOTE: THIS IS UNUSED IF MEMCG IS ENABLED. 919 * 920 * Use mem_cgroup_lruvec() to look up lruvecs. 921 */ 922 struct lruvec __lruvec; 923 924 unsigned long flags; 925 926 ZONE_PADDING(_pad2_) 927 928 /* Per-node vmstats */ 929 struct per_cpu_nodestat __percpu *per_cpu_nodestats; 930 atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS]; 931 } pg_data_t; 932 933 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages) 934 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages) 935 936 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) 937 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid)) 938 939 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat) 940 { 941 return pgdat->node_start_pfn + pgdat->node_spanned_pages; 942 } 943 944 static inline bool pgdat_is_empty(pg_data_t *pgdat) 945 { 946 return !pgdat->node_start_pfn && !pgdat->node_spanned_pages; 947 } 948 949 #include <linux/memory_hotplug.h> 950 951 void build_all_zonelists(pg_data_t *pgdat); 952 void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order, 953 enum zone_type highest_zoneidx); 954 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, 955 int highest_zoneidx, unsigned int alloc_flags, 956 long free_pages); 957 bool zone_watermark_ok(struct zone *z, unsigned int order, 958 unsigned long mark, int highest_zoneidx, 959 unsigned int alloc_flags); 960 bool zone_watermark_ok_safe(struct zone *z, unsigned int order, 961 unsigned long mark, int highest_zoneidx); 962 /* 963 * Memory initialization context, use to differentiate memory added by 964 * the platform statically or via memory hotplug interface. 965 */ 966 enum meminit_context { 967 MEMINIT_EARLY, 968 MEMINIT_HOTPLUG, 969 }; 970 971 extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn, 972 unsigned long size); 973 974 extern void lruvec_init(struct lruvec *lruvec); 975 976 static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec) 977 { 978 #ifdef CONFIG_MEMCG 979 return lruvec->pgdat; 980 #else 981 return container_of(lruvec, struct pglist_data, __lruvec); 982 #endif 983 } 984 985 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 986 int local_memory_node(int node_id); 987 #else 988 static inline int local_memory_node(int node_id) { return node_id; }; 989 #endif 990 991 /* 992 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc. 993 */ 994 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones) 995 996 #ifdef CONFIG_ZONE_DEVICE 997 static inline bool zone_is_zone_device(struct zone *zone) 998 { 999 return zone_idx(zone) == ZONE_DEVICE; 1000 } 1001 #else 1002 static inline bool zone_is_zone_device(struct zone *zone) 1003 { 1004 return false; 1005 } 1006 #endif 1007 1008 /* 1009 * Returns true if a zone has pages managed by the buddy allocator. 1010 * All the reclaim decisions have to use this function rather than 1011 * populated_zone(). If the whole zone is reserved then we can easily 1012 * end up with populated_zone() && !managed_zone(). 1013 */ 1014 static inline bool managed_zone(struct zone *zone) 1015 { 1016 return zone_managed_pages(zone); 1017 } 1018 1019 /* Returns true if a zone has memory */ 1020 static inline bool populated_zone(struct zone *zone) 1021 { 1022 return zone->present_pages; 1023 } 1024 1025 #ifdef CONFIG_NUMA 1026 static inline int zone_to_nid(struct zone *zone) 1027 { 1028 return zone->node; 1029 } 1030 1031 static inline void zone_set_nid(struct zone *zone, int nid) 1032 { 1033 zone->node = nid; 1034 } 1035 #else 1036 static inline int zone_to_nid(struct zone *zone) 1037 { 1038 return 0; 1039 } 1040 1041 static inline void zone_set_nid(struct zone *zone, int nid) {} 1042 #endif 1043 1044 extern int movable_zone; 1045 1046 static inline int is_highmem_idx(enum zone_type idx) 1047 { 1048 #ifdef CONFIG_HIGHMEM 1049 return (idx == ZONE_HIGHMEM || 1050 (idx == ZONE_MOVABLE && movable_zone == ZONE_HIGHMEM)); 1051 #else 1052 return 0; 1053 #endif 1054 } 1055 1056 #ifdef CONFIG_ZONE_DMA 1057 bool has_managed_dma(void); 1058 #else 1059 static inline bool has_managed_dma(void) 1060 { 1061 return false; 1062 } 1063 #endif 1064 1065 /** 1066 * is_highmem - helper function to quickly check if a struct zone is a 1067 * highmem zone or not. This is an attempt to keep references 1068 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum. 1069 * @zone: pointer to struct zone variable 1070 * Return: 1 for a highmem zone, 0 otherwise 1071 */ 1072 static inline int is_highmem(struct zone *zone) 1073 { 1074 #ifdef CONFIG_HIGHMEM 1075 return is_highmem_idx(zone_idx(zone)); 1076 #else 1077 return 0; 1078 #endif 1079 } 1080 1081 /* These two functions are used to setup the per zone pages min values */ 1082 struct ctl_table; 1083 1084 int min_free_kbytes_sysctl_handler(struct ctl_table *, int, void *, size_t *, 1085 loff_t *); 1086 int watermark_scale_factor_sysctl_handler(struct ctl_table *, int, void *, 1087 size_t *, loff_t *); 1088 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES]; 1089 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, void *, 1090 size_t *, loff_t *); 1091 int percpu_pagelist_high_fraction_sysctl_handler(struct ctl_table *, int, 1092 void *, size_t *, loff_t *); 1093 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int, 1094 void *, size_t *, loff_t *); 1095 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int, 1096 void *, size_t *, loff_t *); 1097 int numa_zonelist_order_handler(struct ctl_table *, int, 1098 void *, size_t *, loff_t *); 1099 extern int percpu_pagelist_high_fraction; 1100 extern char numa_zonelist_order[]; 1101 #define NUMA_ZONELIST_ORDER_LEN 16 1102 1103 #ifndef CONFIG_NUMA 1104 1105 extern struct pglist_data contig_page_data; 1106 static inline struct pglist_data *NODE_DATA(int nid) 1107 { 1108 return &contig_page_data; 1109 } 1110 1111 #else /* CONFIG_NUMA */ 1112 1113 #include <asm/mmzone.h> 1114 1115 #endif /* !CONFIG_NUMA */ 1116 1117 extern struct pglist_data *first_online_pgdat(void); 1118 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat); 1119 extern struct zone *next_zone(struct zone *zone); 1120 1121 /** 1122 * for_each_online_pgdat - helper macro to iterate over all online nodes 1123 * @pgdat: pointer to a pg_data_t variable 1124 */ 1125 #define for_each_online_pgdat(pgdat) \ 1126 for (pgdat = first_online_pgdat(); \ 1127 pgdat; \ 1128 pgdat = next_online_pgdat(pgdat)) 1129 /** 1130 * for_each_zone - helper macro to iterate over all memory zones 1131 * @zone: pointer to struct zone variable 1132 * 1133 * The user only needs to declare the zone variable, for_each_zone 1134 * fills it in. 1135 */ 1136 #define for_each_zone(zone) \ 1137 for (zone = (first_online_pgdat())->node_zones; \ 1138 zone; \ 1139 zone = next_zone(zone)) 1140 1141 #define for_each_populated_zone(zone) \ 1142 for (zone = (first_online_pgdat())->node_zones; \ 1143 zone; \ 1144 zone = next_zone(zone)) \ 1145 if (!populated_zone(zone)) \ 1146 ; /* do nothing */ \ 1147 else 1148 1149 static inline struct zone *zonelist_zone(struct zoneref *zoneref) 1150 { 1151 return zoneref->zone; 1152 } 1153 1154 static inline int zonelist_zone_idx(struct zoneref *zoneref) 1155 { 1156 return zoneref->zone_idx; 1157 } 1158 1159 static inline int zonelist_node_idx(struct zoneref *zoneref) 1160 { 1161 return zone_to_nid(zoneref->zone); 1162 } 1163 1164 struct zoneref *__next_zones_zonelist(struct zoneref *z, 1165 enum zone_type highest_zoneidx, 1166 nodemask_t *nodes); 1167 1168 /** 1169 * 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 1170 * @z: The cursor used as a starting point for the search 1171 * @highest_zoneidx: The zone index of the highest zone to return 1172 * @nodes: An optional nodemask to filter the zonelist with 1173 * 1174 * This function returns the next zone at or below a given zone index that is 1175 * within the allowed nodemask using a cursor as the starting point for the 1176 * search. The zoneref returned is a cursor that represents the current zone 1177 * being examined. It should be advanced by one before calling 1178 * next_zones_zonelist again. 1179 * 1180 * Return: the next zone at or below highest_zoneidx within the allowed 1181 * nodemask using a cursor within a zonelist as a starting point 1182 */ 1183 static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z, 1184 enum zone_type highest_zoneidx, 1185 nodemask_t *nodes) 1186 { 1187 if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx)) 1188 return z; 1189 return __next_zones_zonelist(z, highest_zoneidx, nodes); 1190 } 1191 1192 /** 1193 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist 1194 * @zonelist: The zonelist to search for a suitable zone 1195 * @highest_zoneidx: The zone index of the highest zone to return 1196 * @nodes: An optional nodemask to filter the zonelist with 1197 * 1198 * This function returns the first zone at or below a given zone index that is 1199 * within the allowed nodemask. The zoneref returned is a cursor that can be 1200 * used to iterate the zonelist with next_zones_zonelist by advancing it by 1201 * one before calling. 1202 * 1203 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is 1204 * never NULL). This may happen either genuinely, or due to concurrent nodemask 1205 * update due to cpuset modification. 1206 * 1207 * Return: Zoneref pointer for the first suitable zone found 1208 */ 1209 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist, 1210 enum zone_type highest_zoneidx, 1211 nodemask_t *nodes) 1212 { 1213 return next_zones_zonelist(zonelist->_zonerefs, 1214 highest_zoneidx, nodes); 1215 } 1216 1217 /** 1218 * 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 1219 * @zone: The current zone in the iterator 1220 * @z: The current pointer within zonelist->_zonerefs being iterated 1221 * @zlist: The zonelist being iterated 1222 * @highidx: The zone index of the highest zone to return 1223 * @nodemask: Nodemask allowed by the allocator 1224 * 1225 * This iterator iterates though all zones at or below a given zone index and 1226 * within a given nodemask 1227 */ 1228 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \ 1229 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \ 1230 zone; \ 1231 z = next_zones_zonelist(++z, highidx, nodemask), \ 1232 zone = zonelist_zone(z)) 1233 1234 #define for_next_zone_zonelist_nodemask(zone, z, highidx, nodemask) \ 1235 for (zone = z->zone; \ 1236 zone; \ 1237 z = next_zones_zonelist(++z, highidx, nodemask), \ 1238 zone = zonelist_zone(z)) 1239 1240 1241 /** 1242 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index 1243 * @zone: The current zone in the iterator 1244 * @z: The current pointer within zonelist->zones being iterated 1245 * @zlist: The zonelist being iterated 1246 * @highidx: The zone index of the highest zone to return 1247 * 1248 * This iterator iterates though all zones at or below a given zone index. 1249 */ 1250 #define for_each_zone_zonelist(zone, z, zlist, highidx) \ 1251 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL) 1252 1253 /* Whether the 'nodes' are all movable nodes */ 1254 static inline bool movable_only_nodes(nodemask_t *nodes) 1255 { 1256 struct zonelist *zonelist; 1257 struct zoneref *z; 1258 int nid; 1259 1260 if (nodes_empty(*nodes)) 1261 return false; 1262 1263 /* 1264 * We can chose arbitrary node from the nodemask to get a 1265 * zonelist as they are interlinked. We just need to find 1266 * at least one zone that can satisfy kernel allocations. 1267 */ 1268 nid = first_node(*nodes); 1269 zonelist = &NODE_DATA(nid)->node_zonelists[ZONELIST_FALLBACK]; 1270 z = first_zones_zonelist(zonelist, ZONE_NORMAL, nodes); 1271 return (!z->zone) ? true : false; 1272 } 1273 1274 1275 #ifdef CONFIG_SPARSEMEM 1276 #include <asm/sparsemem.h> 1277 #endif 1278 1279 #ifdef CONFIG_FLATMEM 1280 #define pfn_to_nid(pfn) (0) 1281 #endif 1282 1283 #ifdef CONFIG_SPARSEMEM 1284 1285 /* 1286 * PA_SECTION_SHIFT physical address to/from section number 1287 * PFN_SECTION_SHIFT pfn to/from section number 1288 */ 1289 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS) 1290 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT) 1291 1292 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT) 1293 1294 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT) 1295 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1)) 1296 1297 #define SECTION_BLOCKFLAGS_BITS \ 1298 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS) 1299 1300 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS 1301 #error Allocator MAX_ORDER exceeds SECTION_SIZE 1302 #endif 1303 1304 static inline unsigned long pfn_to_section_nr(unsigned long pfn) 1305 { 1306 return pfn >> PFN_SECTION_SHIFT; 1307 } 1308 static inline unsigned long section_nr_to_pfn(unsigned long sec) 1309 { 1310 return sec << PFN_SECTION_SHIFT; 1311 } 1312 1313 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK) 1314 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK) 1315 1316 #define SUBSECTION_SHIFT 21 1317 #define SUBSECTION_SIZE (1UL << SUBSECTION_SHIFT) 1318 1319 #define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT) 1320 #define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT) 1321 #define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1)) 1322 1323 #if SUBSECTION_SHIFT > SECTION_SIZE_BITS 1324 #error Subsection size exceeds section size 1325 #else 1326 #define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT)) 1327 #endif 1328 1329 #define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION) 1330 #define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK) 1331 1332 struct mem_section_usage { 1333 #ifdef CONFIG_SPARSEMEM_VMEMMAP 1334 DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION); 1335 #endif 1336 /* See declaration of similar field in struct zone */ 1337 unsigned long pageblock_flags[0]; 1338 }; 1339 1340 void subsection_map_init(unsigned long pfn, unsigned long nr_pages); 1341 1342 struct page; 1343 struct page_ext; 1344 struct mem_section { 1345 /* 1346 * This is, logically, a pointer to an array of struct 1347 * pages. However, it is stored with some other magic. 1348 * (see sparse.c::sparse_init_one_section()) 1349 * 1350 * Additionally during early boot we encode node id of 1351 * the location of the section here to guide allocation. 1352 * (see sparse.c::memory_present()) 1353 * 1354 * Making it a UL at least makes someone do a cast 1355 * before using it wrong. 1356 */ 1357 unsigned long section_mem_map; 1358 1359 struct mem_section_usage *usage; 1360 #ifdef CONFIG_PAGE_EXTENSION 1361 /* 1362 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use 1363 * section. (see page_ext.h about this.) 1364 */ 1365 struct page_ext *page_ext; 1366 unsigned long pad; 1367 #endif 1368 /* 1369 * WARNING: mem_section must be a power-of-2 in size for the 1370 * calculation and use of SECTION_ROOT_MASK to make sense. 1371 */ 1372 }; 1373 1374 #ifdef CONFIG_SPARSEMEM_EXTREME 1375 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section)) 1376 #else 1377 #define SECTIONS_PER_ROOT 1 1378 #endif 1379 1380 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT) 1381 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT) 1382 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1) 1383 1384 #ifdef CONFIG_SPARSEMEM_EXTREME 1385 extern struct mem_section **mem_section; 1386 #else 1387 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; 1388 #endif 1389 1390 static inline unsigned long *section_to_usemap(struct mem_section *ms) 1391 { 1392 return ms->usage->pageblock_flags; 1393 } 1394 1395 static inline struct mem_section *__nr_to_section(unsigned long nr) 1396 { 1397 unsigned long root = SECTION_NR_TO_ROOT(nr); 1398 1399 if (unlikely(root >= NR_SECTION_ROOTS)) 1400 return NULL; 1401 1402 #ifdef CONFIG_SPARSEMEM_EXTREME 1403 if (!mem_section || !mem_section[root]) 1404 return NULL; 1405 #endif 1406 return &mem_section[root][nr & SECTION_ROOT_MASK]; 1407 } 1408 extern size_t mem_section_usage_size(void); 1409 1410 /* 1411 * We use the lower bits of the mem_map pointer to store 1412 * a little bit of information. The pointer is calculated 1413 * as mem_map - section_nr_to_pfn(pnum). The result is 1414 * aligned to the minimum alignment of the two values: 1415 * 1. All mem_map arrays are page-aligned. 1416 * 2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT 1417 * lowest bits. PFN_SECTION_SHIFT is arch-specific 1418 * (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the 1419 * worst combination is powerpc with 256k pages, 1420 * which results in PFN_SECTION_SHIFT equal 6. 1421 * To sum it up, at least 6 bits are available. 1422 */ 1423 #define SECTION_MARKED_PRESENT (1UL<<0) 1424 #define SECTION_HAS_MEM_MAP (1UL<<1) 1425 #define SECTION_IS_ONLINE (1UL<<2) 1426 #define SECTION_IS_EARLY (1UL<<3) 1427 #define SECTION_TAINT_ZONE_DEVICE (1UL<<4) 1428 #define SECTION_MAP_LAST_BIT (1UL<<5) 1429 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1)) 1430 #define SECTION_NID_SHIFT 6 1431 1432 static inline struct page *__section_mem_map_addr(struct mem_section *section) 1433 { 1434 unsigned long map = section->section_mem_map; 1435 map &= SECTION_MAP_MASK; 1436 return (struct page *)map; 1437 } 1438 1439 static inline int present_section(struct mem_section *section) 1440 { 1441 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT)); 1442 } 1443 1444 static inline int present_section_nr(unsigned long nr) 1445 { 1446 return present_section(__nr_to_section(nr)); 1447 } 1448 1449 static inline int valid_section(struct mem_section *section) 1450 { 1451 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP)); 1452 } 1453 1454 static inline int early_section(struct mem_section *section) 1455 { 1456 return (section && (section->section_mem_map & SECTION_IS_EARLY)); 1457 } 1458 1459 static inline int valid_section_nr(unsigned long nr) 1460 { 1461 return valid_section(__nr_to_section(nr)); 1462 } 1463 1464 static inline int online_section(struct mem_section *section) 1465 { 1466 return (section && (section->section_mem_map & SECTION_IS_ONLINE)); 1467 } 1468 1469 static inline int online_device_section(struct mem_section *section) 1470 { 1471 unsigned long flags = SECTION_IS_ONLINE | SECTION_TAINT_ZONE_DEVICE; 1472 1473 return section && ((section->section_mem_map & flags) == flags); 1474 } 1475 1476 static inline int online_section_nr(unsigned long nr) 1477 { 1478 return online_section(__nr_to_section(nr)); 1479 } 1480 1481 #ifdef CONFIG_MEMORY_HOTPLUG 1482 void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn); 1483 void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn); 1484 #endif 1485 1486 static inline struct mem_section *__pfn_to_section(unsigned long pfn) 1487 { 1488 return __nr_to_section(pfn_to_section_nr(pfn)); 1489 } 1490 1491 extern unsigned long __highest_present_section_nr; 1492 1493 static inline int subsection_map_index(unsigned long pfn) 1494 { 1495 return (pfn & ~(PAGE_SECTION_MASK)) / PAGES_PER_SUBSECTION; 1496 } 1497 1498 #ifdef CONFIG_SPARSEMEM_VMEMMAP 1499 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn) 1500 { 1501 int idx = subsection_map_index(pfn); 1502 1503 return test_bit(idx, ms->usage->subsection_map); 1504 } 1505 #else 1506 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn) 1507 { 1508 return 1; 1509 } 1510 #endif 1511 1512 #ifndef CONFIG_HAVE_ARCH_PFN_VALID 1513 /** 1514 * pfn_valid - check if there is a valid memory map entry for a PFN 1515 * @pfn: the page frame number to check 1516 * 1517 * Check if there is a valid memory map entry aka struct page for the @pfn. 1518 * Note, that availability of the memory map entry does not imply that 1519 * there is actual usable memory at that @pfn. The struct page may 1520 * represent a hole or an unusable page frame. 1521 * 1522 * Return: 1 for PFNs that have memory map entries and 0 otherwise 1523 */ 1524 static inline int pfn_valid(unsigned long pfn) 1525 { 1526 struct mem_section *ms; 1527 1528 /* 1529 * Ensure the upper PAGE_SHIFT bits are clear in the 1530 * pfn. Else it might lead to false positives when 1531 * some of the upper bits are set, but the lower bits 1532 * match a valid pfn. 1533 */ 1534 if (PHYS_PFN(PFN_PHYS(pfn)) != pfn) 1535 return 0; 1536 1537 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 1538 return 0; 1539 ms = __pfn_to_section(pfn); 1540 if (!valid_section(ms)) 1541 return 0; 1542 /* 1543 * Traditionally early sections always returned pfn_valid() for 1544 * the entire section-sized span. 1545 */ 1546 return early_section(ms) || pfn_section_valid(ms, pfn); 1547 } 1548 #endif 1549 1550 static inline int pfn_in_present_section(unsigned long pfn) 1551 { 1552 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 1553 return 0; 1554 return present_section(__pfn_to_section(pfn)); 1555 } 1556 1557 static inline unsigned long next_present_section_nr(unsigned long section_nr) 1558 { 1559 while (++section_nr <= __highest_present_section_nr) { 1560 if (present_section_nr(section_nr)) 1561 return section_nr; 1562 } 1563 1564 return -1; 1565 } 1566 1567 /* 1568 * These are _only_ used during initialisation, therefore they 1569 * can use __initdata ... They could have names to indicate 1570 * this restriction. 1571 */ 1572 #ifdef CONFIG_NUMA 1573 #define pfn_to_nid(pfn) \ 1574 ({ \ 1575 unsigned long __pfn_to_nid_pfn = (pfn); \ 1576 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \ 1577 }) 1578 #else 1579 #define pfn_to_nid(pfn) (0) 1580 #endif 1581 1582 void sparse_init(void); 1583 #else 1584 #define sparse_init() do {} while (0) 1585 #define sparse_index_init(_sec, _nid) do {} while (0) 1586 #define pfn_in_present_section pfn_valid 1587 #define subsection_map_init(_pfn, _nr_pages) do {} while (0) 1588 #endif /* CONFIG_SPARSEMEM */ 1589 1590 #endif /* !__GENERATING_BOUNDS.H */ 1591 #endif /* !__ASSEMBLY__ */ 1592 #endif /* _LINUX_MMZONE_H */ 1593