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 static inline bool is_migrate_movable(int mt) 78 { 79 return is_migrate_cma(mt) || mt == MIGRATE_MOVABLE; 80 } 81 82 #define for_each_migratetype_order(order, type) \ 83 for (order = 0; order < MAX_ORDER; order++) \ 84 for (type = 0; type < MIGRATE_TYPES; type++) 85 86 extern int page_group_by_mobility_disabled; 87 88 #define NR_MIGRATETYPE_BITS (PB_migrate_end - PB_migrate + 1) 89 #define MIGRATETYPE_MASK ((1UL << NR_MIGRATETYPE_BITS) - 1) 90 91 #define get_pageblock_migratetype(page) \ 92 get_pfnblock_flags_mask(page, page_to_pfn(page), \ 93 PB_migrate_end, MIGRATETYPE_MASK) 94 95 struct free_area { 96 struct list_head free_list[MIGRATE_TYPES]; 97 unsigned long nr_free; 98 }; 99 100 struct pglist_data; 101 102 /* 103 * zone->lock and the zone lru_lock are two of the hottest locks in the kernel. 104 * So add a wild amount of padding here to ensure that they fall into separate 105 * cachelines. There are very few zone structures in the machine, so space 106 * consumption is not a concern here. 107 */ 108 #if defined(CONFIG_SMP) 109 struct zone_padding { 110 char x[0]; 111 } ____cacheline_internodealigned_in_smp; 112 #define ZONE_PADDING(name) struct zone_padding name; 113 #else 114 #define ZONE_PADDING(name) 115 #endif 116 117 enum zone_stat_item { 118 /* First 128 byte cacheline (assuming 64 bit words) */ 119 NR_FREE_PAGES, 120 NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */ 121 NR_ZONE_INACTIVE_ANON = NR_ZONE_LRU_BASE, 122 NR_ZONE_ACTIVE_ANON, 123 NR_ZONE_INACTIVE_FILE, 124 NR_ZONE_ACTIVE_FILE, 125 NR_ZONE_UNEVICTABLE, 126 NR_ZONE_WRITE_PENDING, /* Count of dirty, writeback and unstable pages */ 127 NR_MLOCK, /* mlock()ed pages found and moved off LRU */ 128 NR_SLAB_RECLAIMABLE, 129 NR_SLAB_UNRECLAIMABLE, 130 NR_PAGETABLE, /* used for pagetables */ 131 NR_KERNEL_STACK_KB, /* measured in KiB */ 132 /* Second 128 byte cacheline */ 133 NR_BOUNCE, 134 #if IS_ENABLED(CONFIG_ZSMALLOC) 135 NR_ZSPAGES, /* allocated in zsmalloc */ 136 #endif 137 #ifdef CONFIG_NUMA 138 NUMA_HIT, /* allocated in intended node */ 139 NUMA_MISS, /* allocated in non intended node */ 140 NUMA_FOREIGN, /* was intended here, hit elsewhere */ 141 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */ 142 NUMA_LOCAL, /* allocation from local node */ 143 NUMA_OTHER, /* allocation from other node */ 144 #endif 145 NR_FREE_CMA_PAGES, 146 NR_VM_ZONE_STAT_ITEMS }; 147 148 enum node_stat_item { 149 NR_LRU_BASE, 150 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */ 151 NR_ACTIVE_ANON, /* " " " " " */ 152 NR_INACTIVE_FILE, /* " " " " " */ 153 NR_ACTIVE_FILE, /* " " " " " */ 154 NR_UNEVICTABLE, /* " " " " " */ 155 NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */ 156 NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */ 157 WORKINGSET_REFAULT, 158 WORKINGSET_ACTIVATE, 159 WORKINGSET_NODERECLAIM, 160 NR_ANON_MAPPED, /* Mapped anonymous pages */ 161 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables. 162 only modified from process context */ 163 NR_FILE_PAGES, 164 NR_FILE_DIRTY, 165 NR_WRITEBACK, 166 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */ 167 NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */ 168 NR_SHMEM_THPS, 169 NR_SHMEM_PMDMAPPED, 170 NR_ANON_THPS, 171 NR_UNSTABLE_NFS, /* NFS unstable pages */ 172 NR_VMSCAN_WRITE, 173 NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */ 174 NR_DIRTIED, /* page dirtyings since bootup */ 175 NR_WRITTEN, /* page writings since bootup */ 176 NR_VM_NODE_STAT_ITEMS 177 }; 178 179 /* 180 * We do arithmetic on the LRU lists in various places in the code, 181 * so it is important to keep the active lists LRU_ACTIVE higher in 182 * the array than the corresponding inactive lists, and to keep 183 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists. 184 * 185 * This has to be kept in sync with the statistics in zone_stat_item 186 * above and the descriptions in vmstat_text in mm/vmstat.c 187 */ 188 #define LRU_BASE 0 189 #define LRU_ACTIVE 1 190 #define LRU_FILE 2 191 192 enum lru_list { 193 LRU_INACTIVE_ANON = LRU_BASE, 194 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE, 195 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE, 196 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE, 197 LRU_UNEVICTABLE, 198 NR_LRU_LISTS 199 }; 200 201 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++) 202 203 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++) 204 205 static inline int is_file_lru(enum lru_list lru) 206 { 207 return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE); 208 } 209 210 static inline int is_active_lru(enum lru_list lru) 211 { 212 return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE); 213 } 214 215 struct zone_reclaim_stat { 216 /* 217 * The pageout code in vmscan.c keeps track of how many of the 218 * mem/swap backed and file backed pages are referenced. 219 * The higher the rotated/scanned ratio, the more valuable 220 * that cache is. 221 * 222 * The anon LRU stats live in [0], file LRU stats in [1] 223 */ 224 unsigned long recent_rotated[2]; 225 unsigned long recent_scanned[2]; 226 }; 227 228 struct lruvec { 229 struct list_head lists[NR_LRU_LISTS]; 230 struct zone_reclaim_stat reclaim_stat; 231 /* Evictions & activations on the inactive file list */ 232 atomic_long_t inactive_age; 233 /* Refaults at the time of last reclaim cycle */ 234 unsigned long refaults; 235 #ifdef CONFIG_MEMCG 236 struct pglist_data *pgdat; 237 #endif 238 }; 239 240 /* Mask used at gathering information at once (see memcontrol.c) */ 241 #define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE)) 242 #define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON)) 243 #define LRU_ALL ((1 << NR_LRU_LISTS) - 1) 244 245 /* Isolate unmapped file */ 246 #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2) 247 /* Isolate for asynchronous migration */ 248 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4) 249 /* Isolate unevictable pages */ 250 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8) 251 252 /* LRU Isolation modes. */ 253 typedef unsigned __bitwise isolate_mode_t; 254 255 enum zone_watermarks { 256 WMARK_MIN, 257 WMARK_LOW, 258 WMARK_HIGH, 259 NR_WMARK 260 }; 261 262 #define min_wmark_pages(z) (z->watermark[WMARK_MIN]) 263 #define low_wmark_pages(z) (z->watermark[WMARK_LOW]) 264 #define high_wmark_pages(z) (z->watermark[WMARK_HIGH]) 265 266 struct per_cpu_pages { 267 int count; /* number of pages in the list */ 268 int high; /* high watermark, emptying needed */ 269 int batch; /* chunk size for buddy add/remove */ 270 271 /* Lists of pages, one per migrate type stored on the pcp-lists */ 272 struct list_head lists[MIGRATE_PCPTYPES]; 273 }; 274 275 struct per_cpu_pageset { 276 struct per_cpu_pages pcp; 277 #ifdef CONFIG_NUMA 278 s8 expire; 279 #endif 280 #ifdef CONFIG_SMP 281 s8 stat_threshold; 282 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS]; 283 #endif 284 }; 285 286 struct per_cpu_nodestat { 287 s8 stat_threshold; 288 s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS]; 289 }; 290 291 #endif /* !__GENERATING_BOUNDS.H */ 292 293 enum zone_type { 294 #ifdef CONFIG_ZONE_DMA 295 /* 296 * ZONE_DMA is used when there are devices that are not able 297 * to do DMA to all of addressable memory (ZONE_NORMAL). Then we 298 * carve out the portion of memory that is needed for these devices. 299 * The range is arch specific. 300 * 301 * Some examples 302 * 303 * Architecture Limit 304 * --------------------------- 305 * parisc, ia64, sparc <4G 306 * s390 <2G 307 * arm Various 308 * alpha Unlimited or 0-16MB. 309 * 310 * i386, x86_64 and multiple other arches 311 * <16M. 312 */ 313 ZONE_DMA, 314 #endif 315 #ifdef CONFIG_ZONE_DMA32 316 /* 317 * x86_64 needs two ZONE_DMAs because it supports devices that are 318 * only able to do DMA to the lower 16M but also 32 bit devices that 319 * can only do DMA areas below 4G. 320 */ 321 ZONE_DMA32, 322 #endif 323 /* 324 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be 325 * performed on pages in ZONE_NORMAL if the DMA devices support 326 * transfers to all addressable memory. 327 */ 328 ZONE_NORMAL, 329 #ifdef CONFIG_HIGHMEM 330 /* 331 * A memory area that is only addressable by the kernel through 332 * mapping portions into its own address space. This is for example 333 * used by i386 to allow the kernel to address the memory beyond 334 * 900MB. The kernel will set up special mappings (page 335 * table entries on i386) for each page that the kernel needs to 336 * access. 337 */ 338 ZONE_HIGHMEM, 339 #endif 340 ZONE_MOVABLE, 341 #ifdef CONFIG_ZONE_DEVICE 342 ZONE_DEVICE, 343 #endif 344 __MAX_NR_ZONES 345 346 }; 347 348 #ifndef __GENERATING_BOUNDS_H 349 350 struct zone { 351 /* Read-mostly fields */ 352 353 /* zone watermarks, access with *_wmark_pages(zone) macros */ 354 unsigned long watermark[NR_WMARK]; 355 356 unsigned long nr_reserved_highatomic; 357 358 /* 359 * We don't know if the memory that we're going to allocate will be 360 * freeable or/and it will be released eventually, so to avoid totally 361 * wasting several GB of ram we must reserve some of the lower zone 362 * memory (otherwise we risk to run OOM on the lower zones despite 363 * there being tons of freeable ram on the higher zones). This array is 364 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl 365 * changes. 366 */ 367 long lowmem_reserve[MAX_NR_ZONES]; 368 369 #ifdef CONFIG_NUMA 370 int node; 371 #endif 372 struct pglist_data *zone_pgdat; 373 struct per_cpu_pageset __percpu *pageset; 374 375 #ifndef CONFIG_SPARSEMEM 376 /* 377 * Flags for a pageblock_nr_pages block. See pageblock-flags.h. 378 * In SPARSEMEM, this map is stored in struct mem_section 379 */ 380 unsigned long *pageblock_flags; 381 #endif /* CONFIG_SPARSEMEM */ 382 383 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */ 384 unsigned long zone_start_pfn; 385 386 /* 387 * spanned_pages is the total pages spanned by the zone, including 388 * holes, which is calculated as: 389 * spanned_pages = zone_end_pfn - zone_start_pfn; 390 * 391 * present_pages is physical pages existing within the zone, which 392 * is calculated as: 393 * present_pages = spanned_pages - absent_pages(pages in holes); 394 * 395 * managed_pages is present pages managed by the buddy system, which 396 * is calculated as (reserved_pages includes pages allocated by the 397 * bootmem allocator): 398 * managed_pages = present_pages - reserved_pages; 399 * 400 * So present_pages may be used by memory hotplug or memory power 401 * management logic to figure out unmanaged pages by checking 402 * (present_pages - managed_pages). And managed_pages should be used 403 * by page allocator and vm scanner to calculate all kinds of watermarks 404 * and thresholds. 405 * 406 * Locking rules: 407 * 408 * zone_start_pfn and spanned_pages are protected by span_seqlock. 409 * It is a seqlock because it has to be read outside of zone->lock, 410 * and it is done in the main allocator path. But, it is written 411 * quite infrequently. 412 * 413 * The span_seq lock is declared along with zone->lock because it is 414 * frequently read in proximity to zone->lock. It's good to 415 * give them a chance of being in the same cacheline. 416 * 417 * Write access to present_pages at runtime should be protected by 418 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of 419 * present_pages should get_online_mems() to get a stable value. 420 * 421 * Read access to managed_pages should be safe because it's unsigned 422 * long. Write access to zone->managed_pages and totalram_pages are 423 * protected by managed_page_count_lock at runtime. Idealy only 424 * adjust_managed_page_count() should be used instead of directly 425 * touching zone->managed_pages and totalram_pages. 426 */ 427 unsigned long managed_pages; 428 unsigned long spanned_pages; 429 unsigned long present_pages; 430 431 const char *name; 432 433 #ifdef CONFIG_MEMORY_ISOLATION 434 /* 435 * Number of isolated pageblock. It is used to solve incorrect 436 * freepage counting problem due to racy retrieving migratetype 437 * of pageblock. Protected by zone->lock. 438 */ 439 unsigned long nr_isolate_pageblock; 440 #endif 441 442 #ifdef CONFIG_MEMORY_HOTPLUG 443 /* see spanned/present_pages for more description */ 444 seqlock_t span_seqlock; 445 #endif 446 447 int initialized; 448 449 /* Write-intensive fields used from the page allocator */ 450 ZONE_PADDING(_pad1_) 451 452 /* free areas of different sizes */ 453 struct free_area free_area[MAX_ORDER]; 454 455 /* zone flags, see below */ 456 unsigned long flags; 457 458 /* Primarily protects free_area */ 459 spinlock_t lock; 460 461 /* Write-intensive fields used by compaction and vmstats. */ 462 ZONE_PADDING(_pad2_) 463 464 /* 465 * When free pages are below this point, additional steps are taken 466 * when reading the number of free pages to avoid per-cpu counter 467 * drift allowing watermarks to be breached 468 */ 469 unsigned long percpu_drift_mark; 470 471 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 472 /* pfn where compaction free scanner should start */ 473 unsigned long compact_cached_free_pfn; 474 /* pfn where async and sync compaction migration scanner should start */ 475 unsigned long compact_cached_migrate_pfn[2]; 476 #endif 477 478 #ifdef CONFIG_COMPACTION 479 /* 480 * On compaction failure, 1<<compact_defer_shift compactions 481 * are skipped before trying again. The number attempted since 482 * last failure is tracked with compact_considered. 483 */ 484 unsigned int compact_considered; 485 unsigned int compact_defer_shift; 486 int compact_order_failed; 487 #endif 488 489 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 490 /* Set to true when the PG_migrate_skip bits should be cleared */ 491 bool compact_blockskip_flush; 492 #endif 493 494 bool contiguous; 495 496 ZONE_PADDING(_pad3_) 497 /* Zone statistics */ 498 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; 499 } ____cacheline_internodealigned_in_smp; 500 501 enum pgdat_flags { 502 PGDAT_CONGESTED, /* pgdat has many dirty pages backed by 503 * a congested BDI 504 */ 505 PGDAT_DIRTY, /* reclaim scanning has recently found 506 * many dirty file pages at the tail 507 * of the LRU. 508 */ 509 PGDAT_WRITEBACK, /* reclaim scanning has recently found 510 * many pages under writeback 511 */ 512 PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */ 513 }; 514 515 static inline unsigned long zone_end_pfn(const struct zone *zone) 516 { 517 return zone->zone_start_pfn + zone->spanned_pages; 518 } 519 520 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn) 521 { 522 return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone); 523 } 524 525 static inline bool zone_is_initialized(struct zone *zone) 526 { 527 return zone->initialized; 528 } 529 530 static inline bool zone_is_empty(struct zone *zone) 531 { 532 return zone->spanned_pages == 0; 533 } 534 535 /* 536 * The "priority" of VM scanning is how much of the queues we will scan in one 537 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the 538 * queues ("queue_length >> 12") during an aging round. 539 */ 540 #define DEF_PRIORITY 12 541 542 /* Maximum number of zones on a zonelist */ 543 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES) 544 545 enum { 546 ZONELIST_FALLBACK, /* zonelist with fallback */ 547 #ifdef CONFIG_NUMA 548 /* 549 * The NUMA zonelists are doubled because we need zonelists that 550 * restrict the allocations to a single node for __GFP_THISNODE. 551 */ 552 ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */ 553 #endif 554 MAX_ZONELISTS 555 }; 556 557 /* 558 * This struct contains information about a zone in a zonelist. It is stored 559 * here to avoid dereferences into large structures and lookups of tables 560 */ 561 struct zoneref { 562 struct zone *zone; /* Pointer to actual zone */ 563 int zone_idx; /* zone_idx(zoneref->zone) */ 564 }; 565 566 /* 567 * One allocation request operates on a zonelist. A zonelist 568 * is a list of zones, the first one is the 'goal' of the 569 * allocation, the other zones are fallback zones, in decreasing 570 * priority. 571 * 572 * To speed the reading of the zonelist, the zonerefs contain the zone index 573 * of the entry being read. Helper functions to access information given 574 * a struct zoneref are 575 * 576 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs 577 * zonelist_zone_idx() - Return the index of the zone for an entry 578 * zonelist_node_idx() - Return the index of the node for an entry 579 */ 580 struct zonelist { 581 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1]; 582 }; 583 584 #ifndef CONFIG_DISCONTIGMEM 585 /* The array of struct pages - for discontigmem use pgdat->lmem_map */ 586 extern struct page *mem_map; 587 #endif 588 589 /* 590 * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM 591 * (mostly NUMA machines?) to denote a higher-level memory zone than the 592 * zone denotes. 593 * 594 * On NUMA machines, each NUMA node would have a pg_data_t to describe 595 * it's memory layout. 596 * 597 * Memory statistics and page replacement data structures are maintained on a 598 * per-zone basis. 599 */ 600 struct bootmem_data; 601 typedef struct pglist_data { 602 struct zone node_zones[MAX_NR_ZONES]; 603 struct zonelist node_zonelists[MAX_ZONELISTS]; 604 int nr_zones; 605 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */ 606 struct page *node_mem_map; 607 #ifdef CONFIG_PAGE_EXTENSION 608 struct page_ext *node_page_ext; 609 #endif 610 #endif 611 #ifndef CONFIG_NO_BOOTMEM 612 struct bootmem_data *bdata; 613 #endif 614 #ifdef CONFIG_MEMORY_HOTPLUG 615 /* 616 * Must be held any time you expect node_start_pfn, node_present_pages 617 * or node_spanned_pages stay constant. Holding this will also 618 * guarantee that any pfn_valid() stays that way. 619 * 620 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to 621 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG. 622 * 623 * Nests above zone->lock and zone->span_seqlock 624 */ 625 spinlock_t node_size_lock; 626 #endif 627 unsigned long node_start_pfn; 628 unsigned long node_present_pages; /* total number of physical pages */ 629 unsigned long node_spanned_pages; /* total size of physical page 630 range, including holes */ 631 int node_id; 632 wait_queue_head_t kswapd_wait; 633 wait_queue_head_t pfmemalloc_wait; 634 struct task_struct *kswapd; /* Protected by 635 mem_hotplug_begin/end() */ 636 int kswapd_order; 637 enum zone_type kswapd_classzone_idx; 638 639 int kswapd_failures; /* Number of 'reclaimed == 0' runs */ 640 641 #ifdef CONFIG_COMPACTION 642 int kcompactd_max_order; 643 enum zone_type kcompactd_classzone_idx; 644 wait_queue_head_t kcompactd_wait; 645 struct task_struct *kcompactd; 646 #endif 647 #ifdef CONFIG_NUMA_BALANCING 648 /* Lock serializing the migrate rate limiting window */ 649 spinlock_t numabalancing_migrate_lock; 650 651 /* Rate limiting time interval */ 652 unsigned long numabalancing_migrate_next_window; 653 654 /* Number of pages migrated during the rate limiting time interval */ 655 unsigned long numabalancing_migrate_nr_pages; 656 #endif 657 /* 658 * This is a per-node reserve of pages that are not available 659 * to userspace allocations. 660 */ 661 unsigned long totalreserve_pages; 662 663 #ifdef CONFIG_NUMA 664 /* 665 * zone reclaim becomes active if more unmapped pages exist. 666 */ 667 unsigned long min_unmapped_pages; 668 unsigned long min_slab_pages; 669 #endif /* CONFIG_NUMA */ 670 671 /* Write-intensive fields used by page reclaim */ 672 ZONE_PADDING(_pad1_) 673 spinlock_t lru_lock; 674 675 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 676 /* 677 * If memory initialisation on large machines is deferred then this 678 * is the first PFN that needs to be initialised. 679 */ 680 unsigned long first_deferred_pfn; 681 unsigned long static_init_size; 682 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ 683 684 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 685 spinlock_t split_queue_lock; 686 struct list_head split_queue; 687 unsigned long split_queue_len; 688 #endif 689 690 /* Fields commonly accessed by the page reclaim scanner */ 691 struct lruvec lruvec; 692 693 /* 694 * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on 695 * this node's LRU. Maintained by the pageout code. 696 */ 697 unsigned int inactive_ratio; 698 699 unsigned long flags; 700 701 ZONE_PADDING(_pad2_) 702 703 /* Per-node vmstats */ 704 struct per_cpu_nodestat __percpu *per_cpu_nodestats; 705 atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS]; 706 } pg_data_t; 707 708 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages) 709 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages) 710 #ifdef CONFIG_FLAT_NODE_MEM_MAP 711 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr)) 712 #else 713 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr)) 714 #endif 715 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr)) 716 717 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) 718 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid)) 719 static inline spinlock_t *zone_lru_lock(struct zone *zone) 720 { 721 return &zone->zone_pgdat->lru_lock; 722 } 723 724 static inline struct lruvec *node_lruvec(struct pglist_data *pgdat) 725 { 726 return &pgdat->lruvec; 727 } 728 729 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat) 730 { 731 return pgdat->node_start_pfn + pgdat->node_spanned_pages; 732 } 733 734 static inline bool pgdat_is_empty(pg_data_t *pgdat) 735 { 736 return !pgdat->node_start_pfn && !pgdat->node_spanned_pages; 737 } 738 739 static inline int zone_id(const struct zone *zone) 740 { 741 struct pglist_data *pgdat = zone->zone_pgdat; 742 743 return zone - pgdat->node_zones; 744 } 745 746 #ifdef CONFIG_ZONE_DEVICE 747 static inline bool is_dev_zone(const struct zone *zone) 748 { 749 return zone_id(zone) == ZONE_DEVICE; 750 } 751 #else 752 static inline bool is_dev_zone(const struct zone *zone) 753 { 754 return false; 755 } 756 #endif 757 758 #include <linux/memory_hotplug.h> 759 760 extern struct mutex zonelists_mutex; 761 void build_all_zonelists(pg_data_t *pgdat, struct zone *zone); 762 void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx); 763 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, 764 int classzone_idx, unsigned int alloc_flags, 765 long free_pages); 766 bool zone_watermark_ok(struct zone *z, unsigned int order, 767 unsigned long mark, int classzone_idx, 768 unsigned int alloc_flags); 769 bool zone_watermark_ok_safe(struct zone *z, unsigned int order, 770 unsigned long mark, int classzone_idx); 771 enum memmap_context { 772 MEMMAP_EARLY, 773 MEMMAP_HOTPLUG, 774 }; 775 extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn, 776 unsigned long size); 777 778 extern void lruvec_init(struct lruvec *lruvec); 779 780 static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec) 781 { 782 #ifdef CONFIG_MEMCG 783 return lruvec->pgdat; 784 #else 785 return container_of(lruvec, struct pglist_data, lruvec); 786 #endif 787 } 788 789 extern unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, int zone_idx); 790 791 #ifdef CONFIG_HAVE_MEMORY_PRESENT 792 void memory_present(int nid, unsigned long start, unsigned long end); 793 #else 794 static inline void memory_present(int nid, unsigned long start, unsigned long end) {} 795 #endif 796 797 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 798 int local_memory_node(int node_id); 799 #else 800 static inline int local_memory_node(int node_id) { return node_id; }; 801 #endif 802 803 #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE 804 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long); 805 #endif 806 807 /* 808 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc. 809 */ 810 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones) 811 812 /* 813 * Returns true if a zone has pages managed by the buddy allocator. 814 * All the reclaim decisions have to use this function rather than 815 * populated_zone(). If the whole zone is reserved then we can easily 816 * end up with populated_zone() && !managed_zone(). 817 */ 818 static inline bool managed_zone(struct zone *zone) 819 { 820 return zone->managed_pages; 821 } 822 823 /* Returns true if a zone has memory */ 824 static inline bool populated_zone(struct zone *zone) 825 { 826 return zone->present_pages; 827 } 828 829 extern int movable_zone; 830 831 #ifdef CONFIG_HIGHMEM 832 static inline int zone_movable_is_highmem(void) 833 { 834 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 835 return movable_zone == ZONE_HIGHMEM; 836 #else 837 return (ZONE_MOVABLE - 1) == ZONE_HIGHMEM; 838 #endif 839 } 840 #endif 841 842 static inline int is_highmem_idx(enum zone_type idx) 843 { 844 #ifdef CONFIG_HIGHMEM 845 return (idx == ZONE_HIGHMEM || 846 (idx == ZONE_MOVABLE && zone_movable_is_highmem())); 847 #else 848 return 0; 849 #endif 850 } 851 852 /** 853 * is_highmem - helper function to quickly check if a struct zone is a 854 * highmem zone or not. This is an attempt to keep references 855 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum. 856 * @zone - pointer to struct zone variable 857 */ 858 static inline int is_highmem(struct zone *zone) 859 { 860 #ifdef CONFIG_HIGHMEM 861 return is_highmem_idx(zone_idx(zone)); 862 #else 863 return 0; 864 #endif 865 } 866 867 /* These two functions are used to setup the per zone pages min values */ 868 struct ctl_table; 869 int min_free_kbytes_sysctl_handler(struct ctl_table *, int, 870 void __user *, size_t *, loff_t *); 871 int watermark_scale_factor_sysctl_handler(struct ctl_table *, int, 872 void __user *, size_t *, loff_t *); 873 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1]; 874 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, 875 void __user *, size_t *, loff_t *); 876 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, 877 void __user *, size_t *, loff_t *); 878 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int, 879 void __user *, size_t *, loff_t *); 880 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int, 881 void __user *, size_t *, loff_t *); 882 883 extern int numa_zonelist_order_handler(struct ctl_table *, int, 884 void __user *, size_t *, loff_t *); 885 extern char numa_zonelist_order[]; 886 #define NUMA_ZONELIST_ORDER_LEN 16 /* string buffer size */ 887 888 #ifndef CONFIG_NEED_MULTIPLE_NODES 889 890 extern struct pglist_data contig_page_data; 891 #define NODE_DATA(nid) (&contig_page_data) 892 #define NODE_MEM_MAP(nid) mem_map 893 894 #else /* CONFIG_NEED_MULTIPLE_NODES */ 895 896 #include <asm/mmzone.h> 897 898 #endif /* !CONFIG_NEED_MULTIPLE_NODES */ 899 900 extern struct pglist_data *first_online_pgdat(void); 901 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat); 902 extern struct zone *next_zone(struct zone *zone); 903 904 /** 905 * for_each_online_pgdat - helper macro to iterate over all online nodes 906 * @pgdat - pointer to a pg_data_t variable 907 */ 908 #define for_each_online_pgdat(pgdat) \ 909 for (pgdat = first_online_pgdat(); \ 910 pgdat; \ 911 pgdat = next_online_pgdat(pgdat)) 912 /** 913 * for_each_zone - helper macro to iterate over all memory zones 914 * @zone - pointer to struct zone variable 915 * 916 * The user only needs to declare the zone variable, for_each_zone 917 * fills it in. 918 */ 919 #define for_each_zone(zone) \ 920 for (zone = (first_online_pgdat())->node_zones; \ 921 zone; \ 922 zone = next_zone(zone)) 923 924 #define for_each_populated_zone(zone) \ 925 for (zone = (first_online_pgdat())->node_zones; \ 926 zone; \ 927 zone = next_zone(zone)) \ 928 if (!populated_zone(zone)) \ 929 ; /* do nothing */ \ 930 else 931 932 static inline struct zone *zonelist_zone(struct zoneref *zoneref) 933 { 934 return zoneref->zone; 935 } 936 937 static inline int zonelist_zone_idx(struct zoneref *zoneref) 938 { 939 return zoneref->zone_idx; 940 } 941 942 static inline int zonelist_node_idx(struct zoneref *zoneref) 943 { 944 #ifdef CONFIG_NUMA 945 /* zone_to_nid not available in this context */ 946 return zoneref->zone->node; 947 #else 948 return 0; 949 #endif /* CONFIG_NUMA */ 950 } 951 952 struct zoneref *__next_zones_zonelist(struct zoneref *z, 953 enum zone_type highest_zoneidx, 954 nodemask_t *nodes); 955 956 /** 957 * 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 958 * @z - The cursor used as a starting point for the search 959 * @highest_zoneidx - The zone index of the highest zone to return 960 * @nodes - An optional nodemask to filter the zonelist with 961 * 962 * This function returns the next zone at or below a given zone index that is 963 * within the allowed nodemask using a cursor as the starting point for the 964 * search. The zoneref returned is a cursor that represents the current zone 965 * being examined. It should be advanced by one before calling 966 * next_zones_zonelist again. 967 */ 968 static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z, 969 enum zone_type highest_zoneidx, 970 nodemask_t *nodes) 971 { 972 if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx)) 973 return z; 974 return __next_zones_zonelist(z, highest_zoneidx, nodes); 975 } 976 977 /** 978 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist 979 * @zonelist - The zonelist to search for a suitable zone 980 * @highest_zoneidx - The zone index of the highest zone to return 981 * @nodes - An optional nodemask to filter the zonelist with 982 * @return - Zoneref pointer for the first suitable zone found (see below) 983 * 984 * This function returns the first zone at or below a given zone index that is 985 * within the allowed nodemask. The zoneref returned is a cursor that can be 986 * used to iterate the zonelist with next_zones_zonelist by advancing it by 987 * one before calling. 988 * 989 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is 990 * never NULL). This may happen either genuinely, or due to concurrent nodemask 991 * update due to cpuset modification. 992 */ 993 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist, 994 enum zone_type highest_zoneidx, 995 nodemask_t *nodes) 996 { 997 return next_zones_zonelist(zonelist->_zonerefs, 998 highest_zoneidx, nodes); 999 } 1000 1001 /** 1002 * 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 1003 * @zone - The current zone in the iterator 1004 * @z - The current pointer within zonelist->zones being iterated 1005 * @zlist - The zonelist being iterated 1006 * @highidx - The zone index of the highest zone to return 1007 * @nodemask - Nodemask allowed by the allocator 1008 * 1009 * This iterator iterates though all zones at or below a given zone index and 1010 * within a given nodemask 1011 */ 1012 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \ 1013 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \ 1014 zone; \ 1015 z = next_zones_zonelist(++z, highidx, nodemask), \ 1016 zone = zonelist_zone(z)) 1017 1018 #define for_next_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \ 1019 for (zone = z->zone; \ 1020 zone; \ 1021 z = next_zones_zonelist(++z, highidx, nodemask), \ 1022 zone = zonelist_zone(z)) 1023 1024 1025 /** 1026 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index 1027 * @zone - The current zone in the iterator 1028 * @z - The current pointer within zonelist->zones being iterated 1029 * @zlist - The zonelist being iterated 1030 * @highidx - The zone index of the highest zone to return 1031 * 1032 * This iterator iterates though all zones at or below a given zone index. 1033 */ 1034 #define for_each_zone_zonelist(zone, z, zlist, highidx) \ 1035 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL) 1036 1037 #ifdef CONFIG_SPARSEMEM 1038 #include <asm/sparsemem.h> 1039 #endif 1040 1041 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \ 1042 !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) 1043 static inline unsigned long early_pfn_to_nid(unsigned long pfn) 1044 { 1045 return 0; 1046 } 1047 #endif 1048 1049 #ifdef CONFIG_FLATMEM 1050 #define pfn_to_nid(pfn) (0) 1051 #endif 1052 1053 #ifdef CONFIG_SPARSEMEM 1054 1055 /* 1056 * SECTION_SHIFT #bits space required to store a section # 1057 * 1058 * PA_SECTION_SHIFT physical address to/from section number 1059 * PFN_SECTION_SHIFT pfn to/from section number 1060 */ 1061 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS) 1062 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT) 1063 1064 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT) 1065 1066 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT) 1067 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1)) 1068 1069 #define SECTION_BLOCKFLAGS_BITS \ 1070 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS) 1071 1072 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS 1073 #error Allocator MAX_ORDER exceeds SECTION_SIZE 1074 #endif 1075 1076 #define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT) 1077 #define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT) 1078 1079 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK) 1080 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK) 1081 1082 struct page; 1083 struct page_ext; 1084 struct mem_section { 1085 /* 1086 * This is, logically, a pointer to an array of struct 1087 * pages. However, it is stored with some other magic. 1088 * (see sparse.c::sparse_init_one_section()) 1089 * 1090 * Additionally during early boot we encode node id of 1091 * the location of the section here to guide allocation. 1092 * (see sparse.c::memory_present()) 1093 * 1094 * Making it a UL at least makes someone do a cast 1095 * before using it wrong. 1096 */ 1097 unsigned long section_mem_map; 1098 1099 /* See declaration of similar field in struct zone */ 1100 unsigned long *pageblock_flags; 1101 #ifdef CONFIG_PAGE_EXTENSION 1102 /* 1103 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use 1104 * section. (see page_ext.h about this.) 1105 */ 1106 struct page_ext *page_ext; 1107 unsigned long pad; 1108 #endif 1109 /* 1110 * WARNING: mem_section must be a power-of-2 in size for the 1111 * calculation and use of SECTION_ROOT_MASK to make sense. 1112 */ 1113 }; 1114 1115 #ifdef CONFIG_SPARSEMEM_EXTREME 1116 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section)) 1117 #else 1118 #define SECTIONS_PER_ROOT 1 1119 #endif 1120 1121 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT) 1122 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT) 1123 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1) 1124 1125 #ifdef CONFIG_SPARSEMEM_EXTREME 1126 extern struct mem_section *mem_section[NR_SECTION_ROOTS]; 1127 #else 1128 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; 1129 #endif 1130 1131 static inline struct mem_section *__nr_to_section(unsigned long nr) 1132 { 1133 if (!mem_section[SECTION_NR_TO_ROOT(nr)]) 1134 return NULL; 1135 return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; 1136 } 1137 extern int __section_nr(struct mem_section* ms); 1138 extern unsigned long usemap_size(void); 1139 1140 /* 1141 * We use the lower bits of the mem_map pointer to store 1142 * a little bit of information. There should be at least 1143 * 3 bits here due to 32-bit alignment. 1144 */ 1145 #define SECTION_MARKED_PRESENT (1UL<<0) 1146 #define SECTION_HAS_MEM_MAP (1UL<<1) 1147 #define SECTION_MAP_LAST_BIT (1UL<<2) 1148 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1)) 1149 #define SECTION_NID_SHIFT 2 1150 1151 static inline struct page *__section_mem_map_addr(struct mem_section *section) 1152 { 1153 unsigned long map = section->section_mem_map; 1154 map &= SECTION_MAP_MASK; 1155 return (struct page *)map; 1156 } 1157 1158 static inline int present_section(struct mem_section *section) 1159 { 1160 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT)); 1161 } 1162 1163 static inline int present_section_nr(unsigned long nr) 1164 { 1165 return present_section(__nr_to_section(nr)); 1166 } 1167 1168 static inline int valid_section(struct mem_section *section) 1169 { 1170 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP)); 1171 } 1172 1173 static inline int valid_section_nr(unsigned long nr) 1174 { 1175 return valid_section(__nr_to_section(nr)); 1176 } 1177 1178 static inline struct mem_section *__pfn_to_section(unsigned long pfn) 1179 { 1180 return __nr_to_section(pfn_to_section_nr(pfn)); 1181 } 1182 1183 #ifndef CONFIG_HAVE_ARCH_PFN_VALID 1184 static inline int pfn_valid(unsigned long pfn) 1185 { 1186 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 1187 return 0; 1188 return valid_section(__nr_to_section(pfn_to_section_nr(pfn))); 1189 } 1190 #endif 1191 1192 static inline int pfn_present(unsigned long pfn) 1193 { 1194 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 1195 return 0; 1196 return present_section(__nr_to_section(pfn_to_section_nr(pfn))); 1197 } 1198 1199 /* 1200 * These are _only_ used during initialisation, therefore they 1201 * can use __initdata ... They could have names to indicate 1202 * this restriction. 1203 */ 1204 #ifdef CONFIG_NUMA 1205 #define pfn_to_nid(pfn) \ 1206 ({ \ 1207 unsigned long __pfn_to_nid_pfn = (pfn); \ 1208 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \ 1209 }) 1210 #else 1211 #define pfn_to_nid(pfn) (0) 1212 #endif 1213 1214 #define early_pfn_valid(pfn) pfn_valid(pfn) 1215 void sparse_init(void); 1216 #else 1217 #define sparse_init() do {} while (0) 1218 #define sparse_index_init(_sec, _nid) do {} while (0) 1219 #endif /* CONFIG_SPARSEMEM */ 1220 1221 /* 1222 * During memory init memblocks map pfns to nids. The search is expensive and 1223 * this caches recent lookups. The implementation of __early_pfn_to_nid 1224 * may treat start/end as pfns or sections. 1225 */ 1226 struct mminit_pfnnid_cache { 1227 unsigned long last_start; 1228 unsigned long last_end; 1229 int last_nid; 1230 }; 1231 1232 #ifndef early_pfn_valid 1233 #define early_pfn_valid(pfn) (1) 1234 #endif 1235 1236 void memory_present(int nid, unsigned long start, unsigned long end); 1237 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long); 1238 1239 /* 1240 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we 1241 * need to check pfn validility within that MAX_ORDER_NR_PAGES block. 1242 * pfn_valid_within() should be used in this case; we optimise this away 1243 * when we have no holes within a MAX_ORDER_NR_PAGES block. 1244 */ 1245 #ifdef CONFIG_HOLES_IN_ZONE 1246 #define pfn_valid_within(pfn) pfn_valid(pfn) 1247 #else 1248 #define pfn_valid_within(pfn) (1) 1249 #endif 1250 1251 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL 1252 /* 1253 * pfn_valid() is meant to be able to tell if a given PFN has valid memmap 1254 * associated with it or not. In FLATMEM, it is expected that holes always 1255 * have valid memmap as long as there is valid PFNs either side of the hole. 1256 * In SPARSEMEM, it is assumed that a valid section has a memmap for the 1257 * entire section. 1258 * 1259 * However, an ARM, and maybe other embedded architectures in the future 1260 * free memmap backing holes to save memory on the assumption the memmap is 1261 * never used. The page_zone linkages are then broken even though pfn_valid() 1262 * returns true. A walker of the full memmap must then do this additional 1263 * check to ensure the memmap they are looking at is sane by making sure 1264 * the zone and PFN linkages are still valid. This is expensive, but walkers 1265 * of the full memmap are extremely rare. 1266 */ 1267 bool memmap_valid_within(unsigned long pfn, 1268 struct page *page, struct zone *zone); 1269 #else 1270 static inline bool memmap_valid_within(unsigned long pfn, 1271 struct page *page, struct zone *zone) 1272 { 1273 return true; 1274 } 1275 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */ 1276 1277 #endif /* !__GENERATING_BOUNDS.H */ 1278 #endif /* !__ASSEMBLY__ */ 1279 #endif /* _LINUX_MMZONE_H */ 1280