1 #ifndef _LINUX_MMZONE_H 2 #define _LINUX_MMZONE_H 3 4 #ifndef __ASSEMBLY__ 5 #ifndef __GENERATING_BOUNDS_H 6 7 #include <linux/spinlock.h> 8 #include <linux/list.h> 9 #include <linux/wait.h> 10 #include <linux/bitops.h> 11 #include <linux/cache.h> 12 #include <linux/threads.h> 13 #include <linux/numa.h> 14 #include <linux/init.h> 15 #include <linux/seqlock.h> 16 #include <linux/nodemask.h> 17 #include <linux/pageblock-flags.h> 18 #include <linux/page-flags-layout.h> 19 #include <linux/atomic.h> 20 #include <asm/page.h> 21 22 /* Free memory management - zoned buddy allocator. */ 23 #ifndef CONFIG_FORCE_MAX_ZONEORDER 24 #define MAX_ORDER 11 25 #else 26 #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER 27 #endif 28 #define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1)) 29 30 /* 31 * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed 32 * costly to service. That is between allocation orders which should 33 * coalesce naturally under reasonable reclaim pressure and those which 34 * will not. 35 */ 36 #define PAGE_ALLOC_COSTLY_ORDER 3 37 38 enum migratetype { 39 MIGRATE_UNMOVABLE, 40 MIGRATE_MOVABLE, 41 MIGRATE_RECLAIMABLE, 42 MIGRATE_PCPTYPES, /* the number of types on the pcp lists */ 43 MIGRATE_HIGHATOMIC = MIGRATE_PCPTYPES, 44 #ifdef CONFIG_CMA 45 /* 46 * MIGRATE_CMA migration type is designed to mimic the way 47 * ZONE_MOVABLE works. Only movable pages can be allocated 48 * from MIGRATE_CMA pageblocks and page allocator never 49 * implicitly change migration type of MIGRATE_CMA pageblock. 50 * 51 * The way to use it is to change migratetype of a range of 52 * pageblocks to MIGRATE_CMA which can be done by 53 * __free_pageblock_cma() function. What is important though 54 * is that a range of pageblocks must be aligned to 55 * MAX_ORDER_NR_PAGES should biggest page be bigger then 56 * a single pageblock. 57 */ 58 MIGRATE_CMA, 59 #endif 60 #ifdef CONFIG_MEMORY_ISOLATION 61 MIGRATE_ISOLATE, /* can't allocate from here */ 62 #endif 63 MIGRATE_TYPES 64 }; 65 66 /* In mm/page_alloc.c; keep in sync also with show_migration_types() there */ 67 extern char * const migratetype_names[MIGRATE_TYPES]; 68 69 #ifdef CONFIG_CMA 70 # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA) 71 # define is_migrate_cma_page(_page) (get_pageblock_migratetype(_page) == MIGRATE_CMA) 72 #else 73 # define is_migrate_cma(migratetype) false 74 # define is_migrate_cma_page(_page) false 75 #endif 76 77 #define for_each_migratetype_order(order, type) \ 78 for (order = 0; order < MAX_ORDER; order++) \ 79 for (type = 0; type < MIGRATE_TYPES; type++) 80 81 extern int page_group_by_mobility_disabled; 82 83 #define NR_MIGRATETYPE_BITS (PB_migrate_end - PB_migrate + 1) 84 #define MIGRATETYPE_MASK ((1UL << NR_MIGRATETYPE_BITS) - 1) 85 86 #define get_pageblock_migratetype(page) \ 87 get_pfnblock_flags_mask(page, page_to_pfn(page), \ 88 PB_migrate_end, MIGRATETYPE_MASK) 89 90 struct free_area { 91 struct list_head free_list[MIGRATE_TYPES]; 92 unsigned long nr_free; 93 }; 94 95 struct pglist_data; 96 97 /* 98 * zone->lock and the zone lru_lock are two of the hottest locks in the kernel. 99 * So add a wild amount of padding here to ensure that they fall into separate 100 * cachelines. There are very few zone structures in the machine, so space 101 * consumption is not a concern here. 102 */ 103 #if defined(CONFIG_SMP) 104 struct zone_padding { 105 char x[0]; 106 } ____cacheline_internodealigned_in_smp; 107 #define ZONE_PADDING(name) struct zone_padding name; 108 #else 109 #define ZONE_PADDING(name) 110 #endif 111 112 enum zone_stat_item { 113 /* First 128 byte cacheline (assuming 64 bit words) */ 114 NR_FREE_PAGES, 115 NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */ 116 NR_ZONE_INACTIVE_ANON = NR_ZONE_LRU_BASE, 117 NR_ZONE_ACTIVE_ANON, 118 NR_ZONE_INACTIVE_FILE, 119 NR_ZONE_ACTIVE_FILE, 120 NR_ZONE_UNEVICTABLE, 121 NR_ZONE_WRITE_PENDING, /* Count of dirty, writeback and unstable pages */ 122 NR_MLOCK, /* mlock()ed pages found and moved off LRU */ 123 NR_SLAB_RECLAIMABLE, 124 NR_SLAB_UNRECLAIMABLE, 125 NR_PAGETABLE, /* used for pagetables */ 126 NR_KERNEL_STACK_KB, /* measured in KiB */ 127 /* Second 128 byte cacheline */ 128 NR_BOUNCE, 129 #if IS_ENABLED(CONFIG_ZSMALLOC) 130 NR_ZSPAGES, /* allocated in zsmalloc */ 131 #endif 132 #ifdef CONFIG_NUMA 133 NUMA_HIT, /* allocated in intended node */ 134 NUMA_MISS, /* allocated in non intended node */ 135 NUMA_FOREIGN, /* was intended here, hit elsewhere */ 136 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */ 137 NUMA_LOCAL, /* allocation from local node */ 138 NUMA_OTHER, /* allocation from other node */ 139 #endif 140 NR_FREE_CMA_PAGES, 141 NR_VM_ZONE_STAT_ITEMS }; 142 143 enum node_stat_item { 144 NR_LRU_BASE, 145 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */ 146 NR_ACTIVE_ANON, /* " " " " " */ 147 NR_INACTIVE_FILE, /* " " " " " */ 148 NR_ACTIVE_FILE, /* " " " " " */ 149 NR_UNEVICTABLE, /* " " " " " */ 150 NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */ 151 NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */ 152 WORKINGSET_REFAULT, 153 WORKINGSET_ACTIVATE, 154 WORKINGSET_NODERECLAIM, 155 NR_ANON_MAPPED, /* Mapped anonymous pages */ 156 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables. 157 only modified from process context */ 158 NR_FILE_PAGES, 159 NR_FILE_DIRTY, 160 NR_WRITEBACK, 161 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */ 162 NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */ 163 NR_SHMEM_THPS, 164 NR_SHMEM_PMDMAPPED, 165 NR_ANON_THPS, 166 NR_UNSTABLE_NFS, /* NFS unstable pages */ 167 NR_VMSCAN_WRITE, 168 NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */ 169 NR_DIRTIED, /* page dirtyings since bootup */ 170 NR_WRITTEN, /* page writings since bootup */ 171 NR_VM_NODE_STAT_ITEMS 172 }; 173 174 /* 175 * We do arithmetic on the LRU lists in various places in the code, 176 * so it is important to keep the active lists LRU_ACTIVE higher in 177 * the array than the corresponding inactive lists, and to keep 178 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists. 179 * 180 * This has to be kept in sync with the statistics in zone_stat_item 181 * above and the descriptions in vmstat_text in mm/vmstat.c 182 */ 183 #define LRU_BASE 0 184 #define LRU_ACTIVE 1 185 #define LRU_FILE 2 186 187 enum lru_list { 188 LRU_INACTIVE_ANON = LRU_BASE, 189 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE, 190 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE, 191 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE, 192 LRU_UNEVICTABLE, 193 NR_LRU_LISTS 194 }; 195 196 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++) 197 198 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++) 199 200 static inline int is_file_lru(enum lru_list lru) 201 { 202 return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE); 203 } 204 205 static inline int is_active_lru(enum lru_list lru) 206 { 207 return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE); 208 } 209 210 struct zone_reclaim_stat { 211 /* 212 * The pageout code in vmscan.c keeps track of how many of the 213 * mem/swap backed and file backed pages are referenced. 214 * The higher the rotated/scanned ratio, the more valuable 215 * that cache is. 216 * 217 * The anon LRU stats live in [0], file LRU stats in [1] 218 */ 219 unsigned long recent_rotated[2]; 220 unsigned long recent_scanned[2]; 221 }; 222 223 struct lruvec { 224 struct list_head lists[NR_LRU_LISTS]; 225 struct zone_reclaim_stat reclaim_stat; 226 /* Evictions & activations on the inactive file list */ 227 atomic_long_t inactive_age; 228 /* Refaults at the time of last reclaim cycle */ 229 unsigned long refaults; 230 #ifdef CONFIG_MEMCG 231 struct pglist_data *pgdat; 232 #endif 233 }; 234 235 /* Mask used at gathering information at once (see memcontrol.c) */ 236 #define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE)) 237 #define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON)) 238 #define LRU_ALL ((1 << NR_LRU_LISTS) - 1) 239 240 /* Isolate unmapped file */ 241 #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2) 242 /* Isolate for asynchronous migration */ 243 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4) 244 /* Isolate unevictable pages */ 245 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8) 246 247 /* LRU Isolation modes. */ 248 typedef unsigned __bitwise isolate_mode_t; 249 250 enum zone_watermarks { 251 WMARK_MIN, 252 WMARK_LOW, 253 WMARK_HIGH, 254 NR_WMARK 255 }; 256 257 #define min_wmark_pages(z) (z->watermark[WMARK_MIN]) 258 #define low_wmark_pages(z) (z->watermark[WMARK_LOW]) 259 #define high_wmark_pages(z) (z->watermark[WMARK_HIGH]) 260 261 struct per_cpu_pages { 262 int count; /* number of pages in the list */ 263 int high; /* high watermark, emptying needed */ 264 int batch; /* chunk size for buddy add/remove */ 265 266 /* Lists of pages, one per migrate type stored on the pcp-lists */ 267 struct list_head lists[MIGRATE_PCPTYPES]; 268 }; 269 270 struct per_cpu_pageset { 271 struct per_cpu_pages pcp; 272 #ifdef CONFIG_NUMA 273 s8 expire; 274 #endif 275 #ifdef CONFIG_SMP 276 s8 stat_threshold; 277 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS]; 278 #endif 279 }; 280 281 struct per_cpu_nodestat { 282 s8 stat_threshold; 283 s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS]; 284 }; 285 286 #endif /* !__GENERATING_BOUNDS.H */ 287 288 enum zone_type { 289 #ifdef CONFIG_ZONE_DMA 290 /* 291 * ZONE_DMA is used when there are devices that are not able 292 * to do DMA to all of addressable memory (ZONE_NORMAL). Then we 293 * carve out the portion of memory that is needed for these devices. 294 * The range is arch specific. 295 * 296 * Some examples 297 * 298 * Architecture Limit 299 * --------------------------- 300 * parisc, ia64, sparc <4G 301 * s390 <2G 302 * arm Various 303 * alpha Unlimited or 0-16MB. 304 * 305 * i386, x86_64 and multiple other arches 306 * <16M. 307 */ 308 ZONE_DMA, 309 #endif 310 #ifdef CONFIG_ZONE_DMA32 311 /* 312 * x86_64 needs two ZONE_DMAs because it supports devices that are 313 * only able to do DMA to the lower 16M but also 32 bit devices that 314 * can only do DMA areas below 4G. 315 */ 316 ZONE_DMA32, 317 #endif 318 /* 319 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be 320 * performed on pages in ZONE_NORMAL if the DMA devices support 321 * transfers to all addressable memory. 322 */ 323 ZONE_NORMAL, 324 #ifdef CONFIG_HIGHMEM 325 /* 326 * A memory area that is only addressable by the kernel through 327 * mapping portions into its own address space. This is for example 328 * used by i386 to allow the kernel to address the memory beyond 329 * 900MB. The kernel will set up special mappings (page 330 * table entries on i386) for each page that the kernel needs to 331 * access. 332 */ 333 ZONE_HIGHMEM, 334 #endif 335 ZONE_MOVABLE, 336 #ifdef CONFIG_ZONE_DEVICE 337 ZONE_DEVICE, 338 #endif 339 __MAX_NR_ZONES 340 341 }; 342 343 #ifndef __GENERATING_BOUNDS_H 344 345 struct zone { 346 /* Read-mostly fields */ 347 348 /* zone watermarks, access with *_wmark_pages(zone) macros */ 349 unsigned long watermark[NR_WMARK]; 350 351 unsigned long nr_reserved_highatomic; 352 353 /* 354 * We don't know if the memory that we're going to allocate will be 355 * freeable or/and it will be released eventually, so to avoid totally 356 * wasting several GB of ram we must reserve some of the lower zone 357 * memory (otherwise we risk to run OOM on the lower zones despite 358 * there being tons of freeable ram on the higher zones). This array is 359 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl 360 * changes. 361 */ 362 long lowmem_reserve[MAX_NR_ZONES]; 363 364 #ifdef CONFIG_NUMA 365 int node; 366 #endif 367 struct pglist_data *zone_pgdat; 368 struct per_cpu_pageset __percpu *pageset; 369 370 #ifndef CONFIG_SPARSEMEM 371 /* 372 * Flags for a pageblock_nr_pages block. See pageblock-flags.h. 373 * In SPARSEMEM, this map is stored in struct mem_section 374 */ 375 unsigned long *pageblock_flags; 376 #endif /* CONFIG_SPARSEMEM */ 377 378 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */ 379 unsigned long zone_start_pfn; 380 381 /* 382 * spanned_pages is the total pages spanned by the zone, including 383 * holes, which is calculated as: 384 * spanned_pages = zone_end_pfn - zone_start_pfn; 385 * 386 * present_pages is physical pages existing within the zone, which 387 * is calculated as: 388 * present_pages = spanned_pages - absent_pages(pages in holes); 389 * 390 * managed_pages is present pages managed by the buddy system, which 391 * is calculated as (reserved_pages includes pages allocated by the 392 * bootmem allocator): 393 * managed_pages = present_pages - reserved_pages; 394 * 395 * So present_pages may be used by memory hotplug or memory power 396 * management logic to figure out unmanaged pages by checking 397 * (present_pages - managed_pages). And managed_pages should be used 398 * by page allocator and vm scanner to calculate all kinds of watermarks 399 * and thresholds. 400 * 401 * Locking rules: 402 * 403 * zone_start_pfn and spanned_pages are protected by span_seqlock. 404 * It is a seqlock because it has to be read outside of zone->lock, 405 * and it is done in the main allocator path. But, it is written 406 * quite infrequently. 407 * 408 * The span_seq lock is declared along with zone->lock because it is 409 * frequently read in proximity to zone->lock. It's good to 410 * give them a chance of being in the same cacheline. 411 * 412 * Write access to present_pages at runtime should be protected by 413 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of 414 * present_pages should get_online_mems() to get a stable value. 415 * 416 * Read access to managed_pages should be safe because it's unsigned 417 * long. Write access to zone->managed_pages and totalram_pages are 418 * protected by managed_page_count_lock at runtime. Idealy only 419 * adjust_managed_page_count() should be used instead of directly 420 * touching zone->managed_pages and totalram_pages. 421 */ 422 unsigned long managed_pages; 423 unsigned long spanned_pages; 424 unsigned long present_pages; 425 426 const char *name; 427 428 #ifdef CONFIG_MEMORY_ISOLATION 429 /* 430 * Number of isolated pageblock. It is used to solve incorrect 431 * freepage counting problem due to racy retrieving migratetype 432 * of pageblock. Protected by zone->lock. 433 */ 434 unsigned long nr_isolate_pageblock; 435 #endif 436 437 #ifdef CONFIG_MEMORY_HOTPLUG 438 /* see spanned/present_pages for more description */ 439 seqlock_t span_seqlock; 440 #endif 441 442 int initialized; 443 444 /* Write-intensive fields used from the page allocator */ 445 ZONE_PADDING(_pad1_) 446 447 /* free areas of different sizes */ 448 struct free_area free_area[MAX_ORDER]; 449 450 /* zone flags, see below */ 451 unsigned long flags; 452 453 /* Primarily protects free_area */ 454 spinlock_t lock; 455 456 /* Write-intensive fields used by compaction and vmstats. */ 457 ZONE_PADDING(_pad2_) 458 459 /* 460 * When free pages are below this point, additional steps are taken 461 * when reading the number of free pages to avoid per-cpu counter 462 * drift allowing watermarks to be breached 463 */ 464 unsigned long percpu_drift_mark; 465 466 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 467 /* pfn where compaction free scanner should start */ 468 unsigned long compact_cached_free_pfn; 469 /* pfn where async and sync compaction migration scanner should start */ 470 unsigned long compact_cached_migrate_pfn[2]; 471 #endif 472 473 #ifdef CONFIG_COMPACTION 474 /* 475 * On compaction failure, 1<<compact_defer_shift compactions 476 * are skipped before trying again. The number attempted since 477 * last failure is tracked with compact_considered. 478 */ 479 unsigned int compact_considered; 480 unsigned int compact_defer_shift; 481 int compact_order_failed; 482 #endif 483 484 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 485 /* Set to true when the PG_migrate_skip bits should be cleared */ 486 bool compact_blockskip_flush; 487 #endif 488 489 bool contiguous; 490 491 ZONE_PADDING(_pad3_) 492 /* Zone statistics */ 493 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; 494 } ____cacheline_internodealigned_in_smp; 495 496 enum pgdat_flags { 497 PGDAT_CONGESTED, /* pgdat has many dirty pages backed by 498 * a congested BDI 499 */ 500 PGDAT_DIRTY, /* reclaim scanning has recently found 501 * many dirty file pages at the tail 502 * of the LRU. 503 */ 504 PGDAT_WRITEBACK, /* reclaim scanning has recently found 505 * many pages under writeback 506 */ 507 PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */ 508 }; 509 510 static inline unsigned long zone_end_pfn(const struct zone *zone) 511 { 512 return zone->zone_start_pfn + zone->spanned_pages; 513 } 514 515 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn) 516 { 517 return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone); 518 } 519 520 static inline bool zone_is_initialized(struct zone *zone) 521 { 522 return zone->initialized; 523 } 524 525 static inline bool zone_is_empty(struct zone *zone) 526 { 527 return zone->spanned_pages == 0; 528 } 529 530 /* 531 * The "priority" of VM scanning is how much of the queues we will scan in one 532 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the 533 * queues ("queue_length >> 12") during an aging round. 534 */ 535 #define DEF_PRIORITY 12 536 537 /* Maximum number of zones on a zonelist */ 538 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES) 539 540 enum { 541 ZONELIST_FALLBACK, /* zonelist with fallback */ 542 #ifdef CONFIG_NUMA 543 /* 544 * The NUMA zonelists are doubled because we need zonelists that 545 * restrict the allocations to a single node for __GFP_THISNODE. 546 */ 547 ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */ 548 #endif 549 MAX_ZONELISTS 550 }; 551 552 /* 553 * This struct contains information about a zone in a zonelist. It is stored 554 * here to avoid dereferences into large structures and lookups of tables 555 */ 556 struct zoneref { 557 struct zone *zone; /* Pointer to actual zone */ 558 int zone_idx; /* zone_idx(zoneref->zone) */ 559 }; 560 561 /* 562 * One allocation request operates on a zonelist. A zonelist 563 * is a list of zones, the first one is the 'goal' of the 564 * allocation, the other zones are fallback zones, in decreasing 565 * priority. 566 * 567 * To speed the reading of the zonelist, the zonerefs contain the zone index 568 * of the entry being read. Helper functions to access information given 569 * a struct zoneref are 570 * 571 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs 572 * zonelist_zone_idx() - Return the index of the zone for an entry 573 * zonelist_node_idx() - Return the index of the node for an entry 574 */ 575 struct zonelist { 576 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1]; 577 }; 578 579 #ifndef CONFIG_DISCONTIGMEM 580 /* The array of struct pages - for discontigmem use pgdat->lmem_map */ 581 extern struct page *mem_map; 582 #endif 583 584 /* 585 * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM 586 * (mostly NUMA machines?) to denote a higher-level memory zone than the 587 * zone denotes. 588 * 589 * On NUMA machines, each NUMA node would have a pg_data_t to describe 590 * it's memory layout. 591 * 592 * Memory statistics and page replacement data structures are maintained on a 593 * per-zone basis. 594 */ 595 struct bootmem_data; 596 typedef struct pglist_data { 597 struct zone node_zones[MAX_NR_ZONES]; 598 struct zonelist node_zonelists[MAX_ZONELISTS]; 599 int nr_zones; 600 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */ 601 struct page *node_mem_map; 602 #ifdef CONFIG_PAGE_EXTENSION 603 struct page_ext *node_page_ext; 604 #endif 605 #endif 606 #ifndef CONFIG_NO_BOOTMEM 607 struct bootmem_data *bdata; 608 #endif 609 #ifdef CONFIG_MEMORY_HOTPLUG 610 /* 611 * Must be held any time you expect node_start_pfn, node_present_pages 612 * or node_spanned_pages stay constant. Holding this will also 613 * guarantee that any pfn_valid() stays that way. 614 * 615 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to 616 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG. 617 * 618 * Nests above zone->lock and zone->span_seqlock 619 */ 620 spinlock_t node_size_lock; 621 #endif 622 unsigned long node_start_pfn; 623 unsigned long node_present_pages; /* total number of physical pages */ 624 unsigned long node_spanned_pages; /* total size of physical page 625 range, including holes */ 626 int node_id; 627 wait_queue_head_t kswapd_wait; 628 wait_queue_head_t pfmemalloc_wait; 629 struct task_struct *kswapd; /* Protected by 630 mem_hotplug_begin/end() */ 631 int kswapd_order; 632 enum zone_type kswapd_classzone_idx; 633 634 int kswapd_failures; /* Number of 'reclaimed == 0' runs */ 635 636 #ifdef CONFIG_COMPACTION 637 int kcompactd_max_order; 638 enum zone_type kcompactd_classzone_idx; 639 wait_queue_head_t kcompactd_wait; 640 struct task_struct *kcompactd; 641 #endif 642 #ifdef CONFIG_NUMA_BALANCING 643 /* Lock serializing the migrate rate limiting window */ 644 spinlock_t numabalancing_migrate_lock; 645 646 /* Rate limiting time interval */ 647 unsigned long numabalancing_migrate_next_window; 648 649 /* Number of pages migrated during the rate limiting time interval */ 650 unsigned long numabalancing_migrate_nr_pages; 651 #endif 652 /* 653 * This is a per-node reserve of pages that are not available 654 * to userspace allocations. 655 */ 656 unsigned long totalreserve_pages; 657 658 #ifdef CONFIG_NUMA 659 /* 660 * zone reclaim becomes active if more unmapped pages exist. 661 */ 662 unsigned long min_unmapped_pages; 663 unsigned long min_slab_pages; 664 #endif /* CONFIG_NUMA */ 665 666 /* Write-intensive fields used by page reclaim */ 667 ZONE_PADDING(_pad1_) 668 spinlock_t lru_lock; 669 670 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 671 /* 672 * If memory initialisation on large machines is deferred then this 673 * is the first PFN that needs to be initialised. 674 */ 675 unsigned long first_deferred_pfn; 676 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ 677 678 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 679 spinlock_t split_queue_lock; 680 struct list_head split_queue; 681 unsigned long split_queue_len; 682 #endif 683 684 /* Fields commonly accessed by the page reclaim scanner */ 685 struct lruvec lruvec; 686 687 /* 688 * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on 689 * this node's LRU. Maintained by the pageout code. 690 */ 691 unsigned int inactive_ratio; 692 693 unsigned long flags; 694 695 ZONE_PADDING(_pad2_) 696 697 /* Per-node vmstats */ 698 struct per_cpu_nodestat __percpu *per_cpu_nodestats; 699 atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS]; 700 } pg_data_t; 701 702 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages) 703 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages) 704 #ifdef CONFIG_FLAT_NODE_MEM_MAP 705 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr)) 706 #else 707 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr)) 708 #endif 709 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr)) 710 711 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) 712 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid)) 713 static inline spinlock_t *zone_lru_lock(struct zone *zone) 714 { 715 return &zone->zone_pgdat->lru_lock; 716 } 717 718 static inline struct lruvec *node_lruvec(struct pglist_data *pgdat) 719 { 720 return &pgdat->lruvec; 721 } 722 723 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat) 724 { 725 return pgdat->node_start_pfn + pgdat->node_spanned_pages; 726 } 727 728 static inline bool pgdat_is_empty(pg_data_t *pgdat) 729 { 730 return !pgdat->node_start_pfn && !pgdat->node_spanned_pages; 731 } 732 733 static inline int zone_id(const struct zone *zone) 734 { 735 struct pglist_data *pgdat = zone->zone_pgdat; 736 737 return zone - pgdat->node_zones; 738 } 739 740 #ifdef CONFIG_ZONE_DEVICE 741 static inline bool is_dev_zone(const struct zone *zone) 742 { 743 return zone_id(zone) == ZONE_DEVICE; 744 } 745 #else 746 static inline bool is_dev_zone(const struct zone *zone) 747 { 748 return false; 749 } 750 #endif 751 752 #include <linux/memory_hotplug.h> 753 754 extern struct mutex zonelists_mutex; 755 void build_all_zonelists(pg_data_t *pgdat, struct zone *zone); 756 void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx); 757 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, 758 int classzone_idx, unsigned int alloc_flags, 759 long free_pages); 760 bool zone_watermark_ok(struct zone *z, unsigned int order, 761 unsigned long mark, int classzone_idx, 762 unsigned int alloc_flags); 763 bool zone_watermark_ok_safe(struct zone *z, unsigned int order, 764 unsigned long mark, int classzone_idx); 765 enum memmap_context { 766 MEMMAP_EARLY, 767 MEMMAP_HOTPLUG, 768 }; 769 extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn, 770 unsigned long size); 771 772 extern void lruvec_init(struct lruvec *lruvec); 773 774 static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec) 775 { 776 #ifdef CONFIG_MEMCG 777 return lruvec->pgdat; 778 #else 779 return container_of(lruvec, struct pglist_data, lruvec); 780 #endif 781 } 782 783 extern unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, int zone_idx); 784 785 #ifdef CONFIG_HAVE_MEMORY_PRESENT 786 void memory_present(int nid, unsigned long start, unsigned long end); 787 #else 788 static inline void memory_present(int nid, unsigned long start, unsigned long end) {} 789 #endif 790 791 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 792 int local_memory_node(int node_id); 793 #else 794 static inline int local_memory_node(int node_id) { return node_id; }; 795 #endif 796 797 #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE 798 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long); 799 #endif 800 801 /* 802 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc. 803 */ 804 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones) 805 806 /* 807 * Returns true if a zone has pages managed by the buddy allocator. 808 * All the reclaim decisions have to use this function rather than 809 * populated_zone(). If the whole zone is reserved then we can easily 810 * end up with populated_zone() && !managed_zone(). 811 */ 812 static inline bool managed_zone(struct zone *zone) 813 { 814 return zone->managed_pages; 815 } 816 817 /* Returns true if a zone has memory */ 818 static inline bool populated_zone(struct zone *zone) 819 { 820 return zone->present_pages; 821 } 822 823 extern int movable_zone; 824 825 #ifdef CONFIG_HIGHMEM 826 static inline int zone_movable_is_highmem(void) 827 { 828 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 829 return movable_zone == ZONE_HIGHMEM; 830 #else 831 return (ZONE_MOVABLE - 1) == ZONE_HIGHMEM; 832 #endif 833 } 834 #endif 835 836 static inline int is_highmem_idx(enum zone_type idx) 837 { 838 #ifdef CONFIG_HIGHMEM 839 return (idx == ZONE_HIGHMEM || 840 (idx == ZONE_MOVABLE && zone_movable_is_highmem())); 841 #else 842 return 0; 843 #endif 844 } 845 846 /** 847 * is_highmem - helper function to quickly check if a struct zone is a 848 * highmem zone or not. This is an attempt to keep references 849 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum. 850 * @zone - pointer to struct zone variable 851 */ 852 static inline int is_highmem(struct zone *zone) 853 { 854 #ifdef CONFIG_HIGHMEM 855 return is_highmem_idx(zone_idx(zone)); 856 #else 857 return 0; 858 #endif 859 } 860 861 /* These two functions are used to setup the per zone pages min values */ 862 struct ctl_table; 863 int min_free_kbytes_sysctl_handler(struct ctl_table *, int, 864 void __user *, size_t *, loff_t *); 865 int watermark_scale_factor_sysctl_handler(struct ctl_table *, int, 866 void __user *, size_t *, loff_t *); 867 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1]; 868 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, 869 void __user *, size_t *, loff_t *); 870 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, 871 void __user *, size_t *, loff_t *); 872 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int, 873 void __user *, size_t *, loff_t *); 874 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int, 875 void __user *, size_t *, loff_t *); 876 877 extern int numa_zonelist_order_handler(struct ctl_table *, int, 878 void __user *, size_t *, loff_t *); 879 extern char numa_zonelist_order[]; 880 #define NUMA_ZONELIST_ORDER_LEN 16 /* string buffer size */ 881 882 #ifndef CONFIG_NEED_MULTIPLE_NODES 883 884 extern struct pglist_data contig_page_data; 885 #define NODE_DATA(nid) (&contig_page_data) 886 #define NODE_MEM_MAP(nid) mem_map 887 888 #else /* CONFIG_NEED_MULTIPLE_NODES */ 889 890 #include <asm/mmzone.h> 891 892 #endif /* !CONFIG_NEED_MULTIPLE_NODES */ 893 894 extern struct pglist_data *first_online_pgdat(void); 895 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat); 896 extern struct zone *next_zone(struct zone *zone); 897 898 /** 899 * for_each_online_pgdat - helper macro to iterate over all online nodes 900 * @pgdat - pointer to a pg_data_t variable 901 */ 902 #define for_each_online_pgdat(pgdat) \ 903 for (pgdat = first_online_pgdat(); \ 904 pgdat; \ 905 pgdat = next_online_pgdat(pgdat)) 906 /** 907 * for_each_zone - helper macro to iterate over all memory zones 908 * @zone - pointer to struct zone variable 909 * 910 * The user only needs to declare the zone variable, for_each_zone 911 * fills it in. 912 */ 913 #define for_each_zone(zone) \ 914 for (zone = (first_online_pgdat())->node_zones; \ 915 zone; \ 916 zone = next_zone(zone)) 917 918 #define for_each_populated_zone(zone) \ 919 for (zone = (first_online_pgdat())->node_zones; \ 920 zone; \ 921 zone = next_zone(zone)) \ 922 if (!populated_zone(zone)) \ 923 ; /* do nothing */ \ 924 else 925 926 static inline struct zone *zonelist_zone(struct zoneref *zoneref) 927 { 928 return zoneref->zone; 929 } 930 931 static inline int zonelist_zone_idx(struct zoneref *zoneref) 932 { 933 return zoneref->zone_idx; 934 } 935 936 static inline int zonelist_node_idx(struct zoneref *zoneref) 937 { 938 #ifdef CONFIG_NUMA 939 /* zone_to_nid not available in this context */ 940 return zoneref->zone->node; 941 #else 942 return 0; 943 #endif /* CONFIG_NUMA */ 944 } 945 946 struct zoneref *__next_zones_zonelist(struct zoneref *z, 947 enum zone_type highest_zoneidx, 948 nodemask_t *nodes); 949 950 /** 951 * 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 952 * @z - The cursor used as a starting point for the search 953 * @highest_zoneidx - The zone index of the highest zone to return 954 * @nodes - An optional nodemask to filter the zonelist with 955 * 956 * This function returns the next zone at or below a given zone index that is 957 * within the allowed nodemask using a cursor as the starting point for the 958 * search. The zoneref returned is a cursor that represents the current zone 959 * being examined. It should be advanced by one before calling 960 * next_zones_zonelist again. 961 */ 962 static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z, 963 enum zone_type highest_zoneidx, 964 nodemask_t *nodes) 965 { 966 if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx)) 967 return z; 968 return __next_zones_zonelist(z, highest_zoneidx, nodes); 969 } 970 971 /** 972 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist 973 * @zonelist - The zonelist to search for a suitable zone 974 * @highest_zoneidx - The zone index of the highest zone to return 975 * @nodes - An optional nodemask to filter the zonelist with 976 * @return - Zoneref pointer for the first suitable zone found (see below) 977 * 978 * This function returns the first zone at or below a given zone index that is 979 * within the allowed nodemask. The zoneref returned is a cursor that can be 980 * used to iterate the zonelist with next_zones_zonelist by advancing it by 981 * one before calling. 982 * 983 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is 984 * never NULL). This may happen either genuinely, or due to concurrent nodemask 985 * update due to cpuset modification. 986 */ 987 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist, 988 enum zone_type highest_zoneidx, 989 nodemask_t *nodes) 990 { 991 return next_zones_zonelist(zonelist->_zonerefs, 992 highest_zoneidx, nodes); 993 } 994 995 /** 996 * 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 997 * @zone - The current zone in the iterator 998 * @z - The current pointer within zonelist->zones being iterated 999 * @zlist - The zonelist being iterated 1000 * @highidx - The zone index of the highest zone to return 1001 * @nodemask - Nodemask allowed by the allocator 1002 * 1003 * This iterator iterates though all zones at or below a given zone index and 1004 * within a given nodemask 1005 */ 1006 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \ 1007 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \ 1008 zone; \ 1009 z = next_zones_zonelist(++z, highidx, nodemask), \ 1010 zone = zonelist_zone(z)) 1011 1012 #define for_next_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \ 1013 for (zone = z->zone; \ 1014 zone; \ 1015 z = next_zones_zonelist(++z, highidx, nodemask), \ 1016 zone = zonelist_zone(z)) 1017 1018 1019 /** 1020 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index 1021 * @zone - The current zone in the iterator 1022 * @z - The current pointer within zonelist->zones being iterated 1023 * @zlist - The zonelist being iterated 1024 * @highidx - The zone index of the highest zone to return 1025 * 1026 * This iterator iterates though all zones at or below a given zone index. 1027 */ 1028 #define for_each_zone_zonelist(zone, z, zlist, highidx) \ 1029 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL) 1030 1031 #ifdef CONFIG_SPARSEMEM 1032 #include <asm/sparsemem.h> 1033 #endif 1034 1035 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \ 1036 !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) 1037 static inline unsigned long early_pfn_to_nid(unsigned long pfn) 1038 { 1039 return 0; 1040 } 1041 #endif 1042 1043 #ifdef CONFIG_FLATMEM 1044 #define pfn_to_nid(pfn) (0) 1045 #endif 1046 1047 #ifdef CONFIG_SPARSEMEM 1048 1049 /* 1050 * SECTION_SHIFT #bits space required to store a section # 1051 * 1052 * PA_SECTION_SHIFT physical address to/from section number 1053 * PFN_SECTION_SHIFT pfn to/from section number 1054 */ 1055 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS) 1056 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT) 1057 1058 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT) 1059 1060 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT) 1061 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1)) 1062 1063 #define SECTION_BLOCKFLAGS_BITS \ 1064 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS) 1065 1066 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS 1067 #error Allocator MAX_ORDER exceeds SECTION_SIZE 1068 #endif 1069 1070 #define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT) 1071 #define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT) 1072 1073 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK) 1074 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK) 1075 1076 struct page; 1077 struct page_ext; 1078 struct mem_section { 1079 /* 1080 * This is, logically, a pointer to an array of struct 1081 * pages. However, it is stored with some other magic. 1082 * (see sparse.c::sparse_init_one_section()) 1083 * 1084 * Additionally during early boot we encode node id of 1085 * the location of the section here to guide allocation. 1086 * (see sparse.c::memory_present()) 1087 * 1088 * Making it a UL at least makes someone do a cast 1089 * before using it wrong. 1090 */ 1091 unsigned long section_mem_map; 1092 1093 /* See declaration of similar field in struct zone */ 1094 unsigned long *pageblock_flags; 1095 #ifdef CONFIG_PAGE_EXTENSION 1096 /* 1097 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use 1098 * section. (see page_ext.h about this.) 1099 */ 1100 struct page_ext *page_ext; 1101 unsigned long pad; 1102 #endif 1103 /* 1104 * WARNING: mem_section must be a power-of-2 in size for the 1105 * calculation and use of SECTION_ROOT_MASK to make sense. 1106 */ 1107 }; 1108 1109 #ifdef CONFIG_SPARSEMEM_EXTREME 1110 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section)) 1111 #else 1112 #define SECTIONS_PER_ROOT 1 1113 #endif 1114 1115 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT) 1116 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT) 1117 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1) 1118 1119 #ifdef CONFIG_SPARSEMEM_EXTREME 1120 extern struct mem_section *mem_section[NR_SECTION_ROOTS]; 1121 #else 1122 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; 1123 #endif 1124 1125 static inline struct mem_section *__nr_to_section(unsigned long nr) 1126 { 1127 if (!mem_section[SECTION_NR_TO_ROOT(nr)]) 1128 return NULL; 1129 return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; 1130 } 1131 extern int __section_nr(struct mem_section* ms); 1132 extern unsigned long usemap_size(void); 1133 1134 /* 1135 * We use the lower bits of the mem_map pointer to store 1136 * a little bit of information. There should be at least 1137 * 3 bits here due to 32-bit alignment. 1138 */ 1139 #define SECTION_MARKED_PRESENT (1UL<<0) 1140 #define SECTION_HAS_MEM_MAP (1UL<<1) 1141 #define SECTION_MAP_LAST_BIT (1UL<<2) 1142 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1)) 1143 #define SECTION_NID_SHIFT 2 1144 1145 static inline struct page *__section_mem_map_addr(struct mem_section *section) 1146 { 1147 unsigned long map = section->section_mem_map; 1148 map &= SECTION_MAP_MASK; 1149 return (struct page *)map; 1150 } 1151 1152 static inline int present_section(struct mem_section *section) 1153 { 1154 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT)); 1155 } 1156 1157 static inline int present_section_nr(unsigned long nr) 1158 { 1159 return present_section(__nr_to_section(nr)); 1160 } 1161 1162 static inline int valid_section(struct mem_section *section) 1163 { 1164 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP)); 1165 } 1166 1167 static inline int valid_section_nr(unsigned long nr) 1168 { 1169 return valid_section(__nr_to_section(nr)); 1170 } 1171 1172 static inline struct mem_section *__pfn_to_section(unsigned long pfn) 1173 { 1174 return __nr_to_section(pfn_to_section_nr(pfn)); 1175 } 1176 1177 #ifndef CONFIG_HAVE_ARCH_PFN_VALID 1178 static inline int pfn_valid(unsigned long pfn) 1179 { 1180 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 1181 return 0; 1182 return valid_section(__nr_to_section(pfn_to_section_nr(pfn))); 1183 } 1184 #endif 1185 1186 static inline int pfn_present(unsigned long pfn) 1187 { 1188 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 1189 return 0; 1190 return present_section(__nr_to_section(pfn_to_section_nr(pfn))); 1191 } 1192 1193 /* 1194 * These are _only_ used during initialisation, therefore they 1195 * can use __initdata ... They could have names to indicate 1196 * this restriction. 1197 */ 1198 #ifdef CONFIG_NUMA 1199 #define pfn_to_nid(pfn) \ 1200 ({ \ 1201 unsigned long __pfn_to_nid_pfn = (pfn); \ 1202 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \ 1203 }) 1204 #else 1205 #define pfn_to_nid(pfn) (0) 1206 #endif 1207 1208 #define early_pfn_valid(pfn) pfn_valid(pfn) 1209 void sparse_init(void); 1210 #else 1211 #define sparse_init() do {} while (0) 1212 #define sparse_index_init(_sec, _nid) do {} while (0) 1213 #endif /* CONFIG_SPARSEMEM */ 1214 1215 /* 1216 * During memory init memblocks map pfns to nids. The search is expensive and 1217 * this caches recent lookups. The implementation of __early_pfn_to_nid 1218 * may treat start/end as pfns or sections. 1219 */ 1220 struct mminit_pfnnid_cache { 1221 unsigned long last_start; 1222 unsigned long last_end; 1223 int last_nid; 1224 }; 1225 1226 #ifndef early_pfn_valid 1227 #define early_pfn_valid(pfn) (1) 1228 #endif 1229 1230 void memory_present(int nid, unsigned long start, unsigned long end); 1231 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long); 1232 1233 /* 1234 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we 1235 * need to check pfn validility within that MAX_ORDER_NR_PAGES block. 1236 * pfn_valid_within() should be used in this case; we optimise this away 1237 * when we have no holes within a MAX_ORDER_NR_PAGES block. 1238 */ 1239 #ifdef CONFIG_HOLES_IN_ZONE 1240 #define pfn_valid_within(pfn) pfn_valid(pfn) 1241 #else 1242 #define pfn_valid_within(pfn) (1) 1243 #endif 1244 1245 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL 1246 /* 1247 * pfn_valid() is meant to be able to tell if a given PFN has valid memmap 1248 * associated with it or not. In FLATMEM, it is expected that holes always 1249 * have valid memmap as long as there is valid PFNs either side of the hole. 1250 * In SPARSEMEM, it is assumed that a valid section has a memmap for the 1251 * entire section. 1252 * 1253 * However, an ARM, and maybe other embedded architectures in the future 1254 * free memmap backing holes to save memory on the assumption the memmap is 1255 * never used. The page_zone linkages are then broken even though pfn_valid() 1256 * returns true. A walker of the full memmap must then do this additional 1257 * check to ensure the memmap they are looking at is sane by making sure 1258 * the zone and PFN linkages are still valid. This is expensive, but walkers 1259 * of the full memmap are extremely rare. 1260 */ 1261 bool memmap_valid_within(unsigned long pfn, 1262 struct page *page, struct zone *zone); 1263 #else 1264 static inline bool memmap_valid_within(unsigned long pfn, 1265 struct page *page, struct zone *zone) 1266 { 1267 return true; 1268 } 1269 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */ 1270 1271 #endif /* !__GENERATING_BOUNDS.H */ 1272 #endif /* !__ASSEMBLY__ */ 1273 #endif /* _LINUX_MMZONE_H */ 1274