page_alloc.c revision 6c0db4664b49417d80988953e69c323721353227
1/* 2 * linux/mm/page_alloc.c 3 * 4 * Manages the free list, the system allocates free pages here. 5 * Note that kmalloc() lives in slab.c 6 * 7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 8 * Swap reorganised 29.12.95, Stephen Tweedie 9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999 11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999 12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000 13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002 14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton) 15 */ 16 17#include <linux/stddef.h> 18#include <linux/mm.h> 19#include <linux/swap.h> 20#include <linux/interrupt.h> 21#include <linux/pagemap.h> 22#include <linux/jiffies.h> 23#include <linux/bootmem.h> 24#include <linux/compiler.h> 25#include <linux/kernel.h> 26#include <linux/module.h> 27#include <linux/suspend.h> 28#include <linux/pagevec.h> 29#include <linux/blkdev.h> 30#include <linux/slab.h> 31#include <linux/oom.h> 32#include <linux/notifier.h> 33#include <linux/topology.h> 34#include <linux/sysctl.h> 35#include <linux/cpu.h> 36#include <linux/cpuset.h> 37#include <linux/memory_hotplug.h> 38#include <linux/nodemask.h> 39#include <linux/vmalloc.h> 40#include <linux/mempolicy.h> 41#include <linux/stop_machine.h> 42#include <linux/sort.h> 43#include <linux/pfn.h> 44#include <linux/backing-dev.h> 45#include <linux/fault-inject.h> 46#include <linux/page-isolation.h> 47#include <linux/page_cgroup.h> 48#include <linux/debugobjects.h> 49#include <linux/kmemleak.h> 50 51#include <asm/tlbflush.h> 52#include <asm/div64.h> 53#include "internal.h" 54 55/* 56 * Array of node states. 57 */ 58nodemask_t node_states[NR_NODE_STATES] __read_mostly = { 59 [N_POSSIBLE] = NODE_MASK_ALL, 60 [N_ONLINE] = { { [0] = 1UL } }, 61#ifndef CONFIG_NUMA 62 [N_NORMAL_MEMORY] = { { [0] = 1UL } }, 63#ifdef CONFIG_HIGHMEM 64 [N_HIGH_MEMORY] = { { [0] = 1UL } }, 65#endif 66 [N_CPU] = { { [0] = 1UL } }, 67#endif /* NUMA */ 68}; 69EXPORT_SYMBOL(node_states); 70 71unsigned long totalram_pages __read_mostly; 72unsigned long totalreserve_pages __read_mostly; 73unsigned long highest_memmap_pfn __read_mostly; 74int percpu_pagelist_fraction; 75 76#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 77int pageblock_order __read_mostly; 78#endif 79 80static void __free_pages_ok(struct page *page, unsigned int order); 81 82/* 83 * results with 256, 32 in the lowmem_reserve sysctl: 84 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) 85 * 1G machine -> (16M dma, 784M normal, 224M high) 86 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA 87 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL 88 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA 89 * 90 * TBD: should special case ZONE_DMA32 machines here - in those we normally 91 * don't need any ZONE_NORMAL reservation 92 */ 93int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 94#ifdef CONFIG_ZONE_DMA 95 256, 96#endif 97#ifdef CONFIG_ZONE_DMA32 98 256, 99#endif 100#ifdef CONFIG_HIGHMEM 101 32, 102#endif 103 32, 104}; 105 106EXPORT_SYMBOL(totalram_pages); 107 108static char * const zone_names[MAX_NR_ZONES] = { 109#ifdef CONFIG_ZONE_DMA 110 "DMA", 111#endif 112#ifdef CONFIG_ZONE_DMA32 113 "DMA32", 114#endif 115 "Normal", 116#ifdef CONFIG_HIGHMEM 117 "HighMem", 118#endif 119 "Movable", 120}; 121 122int min_free_kbytes = 1024; 123 124unsigned long __meminitdata nr_kernel_pages; 125unsigned long __meminitdata nr_all_pages; 126static unsigned long __meminitdata dma_reserve; 127 128#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 129 /* 130 * MAX_ACTIVE_REGIONS determines the maximum number of distinct 131 * ranges of memory (RAM) that may be registered with add_active_range(). 132 * Ranges passed to add_active_range() will be merged if possible 133 * so the number of times add_active_range() can be called is 134 * related to the number of nodes and the number of holes 135 */ 136 #ifdef CONFIG_MAX_ACTIVE_REGIONS 137 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */ 138 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS 139 #else 140 #if MAX_NUMNODES >= 32 141 /* If there can be many nodes, allow up to 50 holes per node */ 142 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50) 143 #else 144 /* By default, allow up to 256 distinct regions */ 145 #define MAX_ACTIVE_REGIONS 256 146 #endif 147 #endif 148 149 static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS]; 150 static int __meminitdata nr_nodemap_entries; 151 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; 152 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; 153 static unsigned long __initdata required_kernelcore; 154 static unsigned long __initdata required_movablecore; 155 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES]; 156 157 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ 158 int movable_zone; 159 EXPORT_SYMBOL(movable_zone); 160#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 161 162#if MAX_NUMNODES > 1 163int nr_node_ids __read_mostly = MAX_NUMNODES; 164EXPORT_SYMBOL(nr_node_ids); 165#endif 166 167int page_group_by_mobility_disabled __read_mostly; 168 169static void set_pageblock_migratetype(struct page *page, int migratetype) 170{ 171 set_pageblock_flags_group(page, (unsigned long)migratetype, 172 PB_migrate, PB_migrate_end); 173} 174 175#ifdef CONFIG_DEBUG_VM 176static int page_outside_zone_boundaries(struct zone *zone, struct page *page) 177{ 178 int ret = 0; 179 unsigned seq; 180 unsigned long pfn = page_to_pfn(page); 181 182 do { 183 seq = zone_span_seqbegin(zone); 184 if (pfn >= zone->zone_start_pfn + zone->spanned_pages) 185 ret = 1; 186 else if (pfn < zone->zone_start_pfn) 187 ret = 1; 188 } while (zone_span_seqretry(zone, seq)); 189 190 return ret; 191} 192 193static int page_is_consistent(struct zone *zone, struct page *page) 194{ 195 if (!pfn_valid_within(page_to_pfn(page))) 196 return 0; 197 if (zone != page_zone(page)) 198 return 0; 199 200 return 1; 201} 202/* 203 * Temporary debugging check for pages not lying within a given zone. 204 */ 205static int bad_range(struct zone *zone, struct page *page) 206{ 207 if (page_outside_zone_boundaries(zone, page)) 208 return 1; 209 if (!page_is_consistent(zone, page)) 210 return 1; 211 212 return 0; 213} 214#else 215static inline int bad_range(struct zone *zone, struct page *page) 216{ 217 return 0; 218} 219#endif 220 221static void bad_page(struct page *page) 222{ 223 static unsigned long resume; 224 static unsigned long nr_shown; 225 static unsigned long nr_unshown; 226 227 /* 228 * Allow a burst of 60 reports, then keep quiet for that minute; 229 * or allow a steady drip of one report per second. 230 */ 231 if (nr_shown == 60) { 232 if (time_before(jiffies, resume)) { 233 nr_unshown++; 234 goto out; 235 } 236 if (nr_unshown) { 237 printk(KERN_ALERT 238 "BUG: Bad page state: %lu messages suppressed\n", 239 nr_unshown); 240 nr_unshown = 0; 241 } 242 nr_shown = 0; 243 } 244 if (nr_shown++ == 0) 245 resume = jiffies + 60 * HZ; 246 247 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n", 248 current->comm, page_to_pfn(page)); 249 printk(KERN_ALERT 250 "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n", 251 page, (void *)page->flags, page_count(page), 252 page_mapcount(page), page->mapping, page->index); 253 254 dump_stack(); 255out: 256 /* Leave bad fields for debug, except PageBuddy could make trouble */ 257 __ClearPageBuddy(page); 258 add_taint(TAINT_BAD_PAGE); 259} 260 261/* 262 * Higher-order pages are called "compound pages". They are structured thusly: 263 * 264 * The first PAGE_SIZE page is called the "head page". 265 * 266 * The remaining PAGE_SIZE pages are called "tail pages". 267 * 268 * All pages have PG_compound set. All pages have their ->private pointing at 269 * the head page (even the head page has this). 270 * 271 * The first tail page's ->lru.next holds the address of the compound page's 272 * put_page() function. Its ->lru.prev holds the order of allocation. 273 * This usage means that zero-order pages may not be compound. 274 */ 275 276static void free_compound_page(struct page *page) 277{ 278 __free_pages_ok(page, compound_order(page)); 279} 280 281void prep_compound_page(struct page *page, unsigned long order) 282{ 283 int i; 284 int nr_pages = 1 << order; 285 286 set_compound_page_dtor(page, free_compound_page); 287 set_compound_order(page, order); 288 __SetPageHead(page); 289 for (i = 1; i < nr_pages; i++) { 290 struct page *p = page + i; 291 292 __SetPageTail(p); 293 p->first_page = page; 294 } 295} 296 297#ifdef CONFIG_HUGETLBFS 298void prep_compound_gigantic_page(struct page *page, unsigned long order) 299{ 300 int i; 301 int nr_pages = 1 << order; 302 struct page *p = page + 1; 303 304 set_compound_page_dtor(page, free_compound_page); 305 set_compound_order(page, order); 306 __SetPageHead(page); 307 for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 308 __SetPageTail(p); 309 p->first_page = page; 310 } 311} 312#endif 313 314static int destroy_compound_page(struct page *page, unsigned long order) 315{ 316 int i; 317 int nr_pages = 1 << order; 318 int bad = 0; 319 320 if (unlikely(compound_order(page) != order) || 321 unlikely(!PageHead(page))) { 322 bad_page(page); 323 bad++; 324 } 325 326 __ClearPageHead(page); 327 328 for (i = 1; i < nr_pages; i++) { 329 struct page *p = page + i; 330 331 if (unlikely(!PageTail(p) || (p->first_page != page))) { 332 bad_page(page); 333 bad++; 334 } 335 __ClearPageTail(p); 336 } 337 338 return bad; 339} 340 341static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) 342{ 343 int i; 344 345 /* 346 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO 347 * and __GFP_HIGHMEM from hard or soft interrupt context. 348 */ 349 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); 350 for (i = 0; i < (1 << order); i++) 351 clear_highpage(page + i); 352} 353 354static inline void set_page_order(struct page *page, int order) 355{ 356 set_page_private(page, order); 357 __SetPageBuddy(page); 358} 359 360static inline void rmv_page_order(struct page *page) 361{ 362 __ClearPageBuddy(page); 363 set_page_private(page, 0); 364} 365 366/* 367 * Locate the struct page for both the matching buddy in our 368 * pair (buddy1) and the combined O(n+1) page they form (page). 369 * 370 * 1) Any buddy B1 will have an order O twin B2 which satisfies 371 * the following equation: 372 * B2 = B1 ^ (1 << O) 373 * For example, if the starting buddy (buddy2) is #8 its order 374 * 1 buddy is #10: 375 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 376 * 377 * 2) Any buddy B will have an order O+1 parent P which 378 * satisfies the following equation: 379 * P = B & ~(1 << O) 380 * 381 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 382 */ 383static inline struct page * 384__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order) 385{ 386 unsigned long buddy_idx = page_idx ^ (1 << order); 387 388 return page + (buddy_idx - page_idx); 389} 390 391static inline unsigned long 392__find_combined_index(unsigned long page_idx, unsigned int order) 393{ 394 return (page_idx & ~(1 << order)); 395} 396 397/* 398 * This function checks whether a page is free && is the buddy 399 * we can do coalesce a page and its buddy if 400 * (a) the buddy is not in a hole && 401 * (b) the buddy is in the buddy system && 402 * (c) a page and its buddy have the same order && 403 * (d) a page and its buddy are in the same zone. 404 * 405 * For recording whether a page is in the buddy system, we use PG_buddy. 406 * Setting, clearing, and testing PG_buddy is serialized by zone->lock. 407 * 408 * For recording page's order, we use page_private(page). 409 */ 410static inline int page_is_buddy(struct page *page, struct page *buddy, 411 int order) 412{ 413 if (!pfn_valid_within(page_to_pfn(buddy))) 414 return 0; 415 416 if (page_zone_id(page) != page_zone_id(buddy)) 417 return 0; 418 419 if (PageBuddy(buddy) && page_order(buddy) == order) { 420 BUG_ON(page_count(buddy) != 0); 421 return 1; 422 } 423 return 0; 424} 425 426/* 427 * Freeing function for a buddy system allocator. 428 * 429 * The concept of a buddy system is to maintain direct-mapped table 430 * (containing bit values) for memory blocks of various "orders". 431 * The bottom level table contains the map for the smallest allocatable 432 * units of memory (here, pages), and each level above it describes 433 * pairs of units from the levels below, hence, "buddies". 434 * At a high level, all that happens here is marking the table entry 435 * at the bottom level available, and propagating the changes upward 436 * as necessary, plus some accounting needed to play nicely with other 437 * parts of the VM system. 438 * At each level, we keep a list of pages, which are heads of continuous 439 * free pages of length of (1 << order) and marked with PG_buddy. Page's 440 * order is recorded in page_private(page) field. 441 * So when we are allocating or freeing one, we can derive the state of the 442 * other. That is, if we allocate a small block, and both were 443 * free, the remainder of the region must be split into blocks. 444 * If a block is freed, and its buddy is also free, then this 445 * triggers coalescing into a block of larger size. 446 * 447 * -- wli 448 */ 449 450static inline void __free_one_page(struct page *page, 451 struct zone *zone, unsigned int order) 452{ 453 unsigned long page_idx; 454 int order_size = 1 << order; 455 int migratetype = get_pageblock_migratetype(page); 456 457 if (unlikely(PageCompound(page))) 458 if (unlikely(destroy_compound_page(page, order))) 459 return; 460 461 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); 462 463 VM_BUG_ON(page_idx & (order_size - 1)); 464 VM_BUG_ON(bad_range(zone, page)); 465 466 __mod_zone_page_state(zone, NR_FREE_PAGES, order_size); 467 while (order < MAX_ORDER-1) { 468 unsigned long combined_idx; 469 struct page *buddy; 470 471 buddy = __page_find_buddy(page, page_idx, order); 472 if (!page_is_buddy(page, buddy, order)) 473 break; 474 475 /* Our buddy is free, merge with it and move up one order. */ 476 list_del(&buddy->lru); 477 zone->free_area[order].nr_free--; 478 rmv_page_order(buddy); 479 combined_idx = __find_combined_index(page_idx, order); 480 page = page + (combined_idx - page_idx); 481 page_idx = combined_idx; 482 order++; 483 } 484 set_page_order(page, order); 485 list_add(&page->lru, 486 &zone->free_area[order].free_list[migratetype]); 487 zone->free_area[order].nr_free++; 488} 489 490static inline int free_pages_check(struct page *page) 491{ 492 free_page_mlock(page); 493 if (unlikely(page_mapcount(page) | 494 (page->mapping != NULL) | 495 (page_count(page) != 0) | 496 (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) { 497 bad_page(page); 498 return 1; 499 } 500 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP) 501 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; 502 return 0; 503} 504 505/* 506 * Frees a list of pages. 507 * Assumes all pages on list are in same zone, and of same order. 508 * count is the number of pages to free. 509 * 510 * If the zone was previously in an "all pages pinned" state then look to 511 * see if this freeing clears that state. 512 * 513 * And clear the zone's pages_scanned counter, to hold off the "all pages are 514 * pinned" detection logic. 515 */ 516static void free_pages_bulk(struct zone *zone, int count, 517 struct list_head *list, int order) 518{ 519 spin_lock(&zone->lock); 520 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); 521 zone->pages_scanned = 0; 522 while (count--) { 523 struct page *page; 524 525 VM_BUG_ON(list_empty(list)); 526 page = list_entry(list->prev, struct page, lru); 527 /* have to delete it as __free_one_page list manipulates */ 528 list_del(&page->lru); 529 __free_one_page(page, zone, order); 530 } 531 spin_unlock(&zone->lock); 532} 533 534static void free_one_page(struct zone *zone, struct page *page, int order) 535{ 536 spin_lock(&zone->lock); 537 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); 538 zone->pages_scanned = 0; 539 __free_one_page(page, zone, order); 540 spin_unlock(&zone->lock); 541} 542 543static void __free_pages_ok(struct page *page, unsigned int order) 544{ 545 unsigned long flags; 546 int i; 547 int bad = 0; 548 549 for (i = 0 ; i < (1 << order) ; ++i) 550 bad += free_pages_check(page + i); 551 if (bad) 552 return; 553 554 if (!PageHighMem(page)) { 555 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order); 556 debug_check_no_obj_freed(page_address(page), 557 PAGE_SIZE << order); 558 } 559 arch_free_page(page, order); 560 kernel_map_pages(page, 1 << order, 0); 561 562 local_irq_save(flags); 563 __count_vm_events(PGFREE, 1 << order); 564 free_one_page(page_zone(page), page, order); 565 local_irq_restore(flags); 566} 567 568/* 569 * permit the bootmem allocator to evade page validation on high-order frees 570 */ 571void __meminit __free_pages_bootmem(struct page *page, unsigned int order) 572{ 573 if (order == 0) { 574 __ClearPageReserved(page); 575 set_page_count(page, 0); 576 set_page_refcounted(page); 577 __free_page(page); 578 } else { 579 int loop; 580 581 prefetchw(page); 582 for (loop = 0; loop < BITS_PER_LONG; loop++) { 583 struct page *p = &page[loop]; 584 585 if (loop + 1 < BITS_PER_LONG) 586 prefetchw(p + 1); 587 __ClearPageReserved(p); 588 set_page_count(p, 0); 589 } 590 591 set_page_refcounted(page); 592 __free_pages(page, order); 593 } 594} 595 596 597/* 598 * The order of subdivision here is critical for the IO subsystem. 599 * Please do not alter this order without good reasons and regression 600 * testing. Specifically, as large blocks of memory are subdivided, 601 * the order in which smaller blocks are delivered depends on the order 602 * they're subdivided in this function. This is the primary factor 603 * influencing the order in which pages are delivered to the IO 604 * subsystem according to empirical testing, and this is also justified 605 * by considering the behavior of a buddy system containing a single 606 * large block of memory acted on by a series of small allocations. 607 * This behavior is a critical factor in sglist merging's success. 608 * 609 * -- wli 610 */ 611static inline void expand(struct zone *zone, struct page *page, 612 int low, int high, struct free_area *area, 613 int migratetype) 614{ 615 unsigned long size = 1 << high; 616 617 while (high > low) { 618 area--; 619 high--; 620 size >>= 1; 621 VM_BUG_ON(bad_range(zone, &page[size])); 622 list_add(&page[size].lru, &area->free_list[migratetype]); 623 area->nr_free++; 624 set_page_order(&page[size], high); 625 } 626} 627 628/* 629 * This page is about to be returned from the page allocator 630 */ 631static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) 632{ 633 if (unlikely(page_mapcount(page) | 634 (page->mapping != NULL) | 635 (page_count(page) != 0) | 636 (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) { 637 bad_page(page); 638 return 1; 639 } 640 641 set_page_private(page, 0); 642 set_page_refcounted(page); 643 644 arch_alloc_page(page, order); 645 kernel_map_pages(page, 1 << order, 1); 646 647 if (gfp_flags & __GFP_ZERO) 648 prep_zero_page(page, order, gfp_flags); 649 650 if (order && (gfp_flags & __GFP_COMP)) 651 prep_compound_page(page, order); 652 653 return 0; 654} 655 656/* 657 * Go through the free lists for the given migratetype and remove 658 * the smallest available page from the freelists 659 */ 660static struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, 661 int migratetype) 662{ 663 unsigned int current_order; 664 struct free_area * area; 665 struct page *page; 666 667 /* Find a page of the appropriate size in the preferred list */ 668 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 669 area = &(zone->free_area[current_order]); 670 if (list_empty(&area->free_list[migratetype])) 671 continue; 672 673 page = list_entry(area->free_list[migratetype].next, 674 struct page, lru); 675 list_del(&page->lru); 676 rmv_page_order(page); 677 area->nr_free--; 678 __mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order)); 679 expand(zone, page, order, current_order, area, migratetype); 680 return page; 681 } 682 683 return NULL; 684} 685 686 687/* 688 * This array describes the order lists are fallen back to when 689 * the free lists for the desirable migrate type are depleted 690 */ 691static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = { 692 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 693 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 694 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, 695 [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */ 696}; 697 698/* 699 * Move the free pages in a range to the free lists of the requested type. 700 * Note that start_page and end_pages are not aligned on a pageblock 701 * boundary. If alignment is required, use move_freepages_block() 702 */ 703static int move_freepages(struct zone *zone, 704 struct page *start_page, struct page *end_page, 705 int migratetype) 706{ 707 struct page *page; 708 unsigned long order; 709 int pages_moved = 0; 710 711#ifndef CONFIG_HOLES_IN_ZONE 712 /* 713 * page_zone is not safe to call in this context when 714 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant 715 * anyway as we check zone boundaries in move_freepages_block(). 716 * Remove at a later date when no bug reports exist related to 717 * grouping pages by mobility 718 */ 719 BUG_ON(page_zone(start_page) != page_zone(end_page)); 720#endif 721 722 for (page = start_page; page <= end_page;) { 723 /* Make sure we are not inadvertently changing nodes */ 724 VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone)); 725 726 if (!pfn_valid_within(page_to_pfn(page))) { 727 page++; 728 continue; 729 } 730 731 if (!PageBuddy(page)) { 732 page++; 733 continue; 734 } 735 736 order = page_order(page); 737 list_del(&page->lru); 738 list_add(&page->lru, 739 &zone->free_area[order].free_list[migratetype]); 740 page += 1 << order; 741 pages_moved += 1 << order; 742 } 743 744 return pages_moved; 745} 746 747static int move_freepages_block(struct zone *zone, struct page *page, 748 int migratetype) 749{ 750 unsigned long start_pfn, end_pfn; 751 struct page *start_page, *end_page; 752 753 start_pfn = page_to_pfn(page); 754 start_pfn = start_pfn & ~(pageblock_nr_pages-1); 755 start_page = pfn_to_page(start_pfn); 756 end_page = start_page + pageblock_nr_pages - 1; 757 end_pfn = start_pfn + pageblock_nr_pages - 1; 758 759 /* Do not cross zone boundaries */ 760 if (start_pfn < zone->zone_start_pfn) 761 start_page = page; 762 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages) 763 return 0; 764 765 return move_freepages(zone, start_page, end_page, migratetype); 766} 767 768/* Remove an element from the buddy allocator from the fallback list */ 769static struct page *__rmqueue_fallback(struct zone *zone, int order, 770 int start_migratetype) 771{ 772 struct free_area * area; 773 int current_order; 774 struct page *page; 775 int migratetype, i; 776 777 /* Find the largest possible block of pages in the other list */ 778 for (current_order = MAX_ORDER-1; current_order >= order; 779 --current_order) { 780 for (i = 0; i < MIGRATE_TYPES - 1; i++) { 781 migratetype = fallbacks[start_migratetype][i]; 782 783 /* MIGRATE_RESERVE handled later if necessary */ 784 if (migratetype == MIGRATE_RESERVE) 785 continue; 786 787 area = &(zone->free_area[current_order]); 788 if (list_empty(&area->free_list[migratetype])) 789 continue; 790 791 page = list_entry(area->free_list[migratetype].next, 792 struct page, lru); 793 area->nr_free--; 794 795 /* 796 * If breaking a large block of pages, move all free 797 * pages to the preferred allocation list. If falling 798 * back for a reclaimable kernel allocation, be more 799 * agressive about taking ownership of free pages 800 */ 801 if (unlikely(current_order >= (pageblock_order >> 1)) || 802 start_migratetype == MIGRATE_RECLAIMABLE) { 803 unsigned long pages; 804 pages = move_freepages_block(zone, page, 805 start_migratetype); 806 807 /* Claim the whole block if over half of it is free */ 808 if (pages >= (1 << (pageblock_order-1))) 809 set_pageblock_migratetype(page, 810 start_migratetype); 811 812 migratetype = start_migratetype; 813 } 814 815 /* Remove the page from the freelists */ 816 list_del(&page->lru); 817 rmv_page_order(page); 818 __mod_zone_page_state(zone, NR_FREE_PAGES, 819 -(1UL << order)); 820 821 if (current_order == pageblock_order) 822 set_pageblock_migratetype(page, 823 start_migratetype); 824 825 expand(zone, page, order, current_order, area, migratetype); 826 return page; 827 } 828 } 829 830 /* Use MIGRATE_RESERVE rather than fail an allocation */ 831 return __rmqueue_smallest(zone, order, MIGRATE_RESERVE); 832} 833 834/* 835 * Do the hard work of removing an element from the buddy allocator. 836 * Call me with the zone->lock already held. 837 */ 838static struct page *__rmqueue(struct zone *zone, unsigned int order, 839 int migratetype) 840{ 841 struct page *page; 842 843 page = __rmqueue_smallest(zone, order, migratetype); 844 845 if (unlikely(!page)) 846 page = __rmqueue_fallback(zone, order, migratetype); 847 848 return page; 849} 850 851/* 852 * Obtain a specified number of elements from the buddy allocator, all under 853 * a single hold of the lock, for efficiency. Add them to the supplied list. 854 * Returns the number of new pages which were placed at *list. 855 */ 856static int rmqueue_bulk(struct zone *zone, unsigned int order, 857 unsigned long count, struct list_head *list, 858 int migratetype) 859{ 860 int i; 861 862 spin_lock(&zone->lock); 863 for (i = 0; i < count; ++i) { 864 struct page *page = __rmqueue(zone, order, migratetype); 865 if (unlikely(page == NULL)) 866 break; 867 868 /* 869 * Split buddy pages returned by expand() are received here 870 * in physical page order. The page is added to the callers and 871 * list and the list head then moves forward. From the callers 872 * perspective, the linked list is ordered by page number in 873 * some conditions. This is useful for IO devices that can 874 * merge IO requests if the physical pages are ordered 875 * properly. 876 */ 877 list_add(&page->lru, list); 878 set_page_private(page, migratetype); 879 list = &page->lru; 880 } 881 spin_unlock(&zone->lock); 882 return i; 883} 884 885#ifdef CONFIG_NUMA 886/* 887 * Called from the vmstat counter updater to drain pagesets of this 888 * currently executing processor on remote nodes after they have 889 * expired. 890 * 891 * Note that this function must be called with the thread pinned to 892 * a single processor. 893 */ 894void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) 895{ 896 unsigned long flags; 897 int to_drain; 898 899 local_irq_save(flags); 900 if (pcp->count >= pcp->batch) 901 to_drain = pcp->batch; 902 else 903 to_drain = pcp->count; 904 free_pages_bulk(zone, to_drain, &pcp->list, 0); 905 pcp->count -= to_drain; 906 local_irq_restore(flags); 907} 908#endif 909 910/* 911 * Drain pages of the indicated processor. 912 * 913 * The processor must either be the current processor and the 914 * thread pinned to the current processor or a processor that 915 * is not online. 916 */ 917static void drain_pages(unsigned int cpu) 918{ 919 unsigned long flags; 920 struct zone *zone; 921 922 for_each_populated_zone(zone) { 923 struct per_cpu_pageset *pset; 924 struct per_cpu_pages *pcp; 925 926 pset = zone_pcp(zone, cpu); 927 928 pcp = &pset->pcp; 929 local_irq_save(flags); 930 free_pages_bulk(zone, pcp->count, &pcp->list, 0); 931 pcp->count = 0; 932 local_irq_restore(flags); 933 } 934} 935 936/* 937 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 938 */ 939void drain_local_pages(void *arg) 940{ 941 drain_pages(smp_processor_id()); 942} 943 944/* 945 * Spill all the per-cpu pages from all CPUs back into the buddy allocator 946 */ 947void drain_all_pages(void) 948{ 949 on_each_cpu(drain_local_pages, NULL, 1); 950} 951 952#ifdef CONFIG_HIBERNATION 953 954void mark_free_pages(struct zone *zone) 955{ 956 unsigned long pfn, max_zone_pfn; 957 unsigned long flags; 958 int order, t; 959 struct list_head *curr; 960 961 if (!zone->spanned_pages) 962 return; 963 964 spin_lock_irqsave(&zone->lock, flags); 965 966 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; 967 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 968 if (pfn_valid(pfn)) { 969 struct page *page = pfn_to_page(pfn); 970 971 if (!swsusp_page_is_forbidden(page)) 972 swsusp_unset_page_free(page); 973 } 974 975 for_each_migratetype_order(order, t) { 976 list_for_each(curr, &zone->free_area[order].free_list[t]) { 977 unsigned long i; 978 979 pfn = page_to_pfn(list_entry(curr, struct page, lru)); 980 for (i = 0; i < (1UL << order); i++) 981 swsusp_set_page_free(pfn_to_page(pfn + i)); 982 } 983 } 984 spin_unlock_irqrestore(&zone->lock, flags); 985} 986#endif /* CONFIG_PM */ 987 988/* 989 * Free a 0-order page 990 */ 991static void free_hot_cold_page(struct page *page, int cold) 992{ 993 struct zone *zone = page_zone(page); 994 struct per_cpu_pages *pcp; 995 unsigned long flags; 996 997 if (PageAnon(page)) 998 page->mapping = NULL; 999 if (free_pages_check(page)) 1000 return; 1001 1002 if (!PageHighMem(page)) { 1003 debug_check_no_locks_freed(page_address(page), PAGE_SIZE); 1004 debug_check_no_obj_freed(page_address(page), PAGE_SIZE); 1005 } 1006 arch_free_page(page, 0); 1007 kernel_map_pages(page, 1, 0); 1008 1009 pcp = &zone_pcp(zone, get_cpu())->pcp; 1010 local_irq_save(flags); 1011 __count_vm_event(PGFREE); 1012 if (cold) 1013 list_add_tail(&page->lru, &pcp->list); 1014 else 1015 list_add(&page->lru, &pcp->list); 1016 set_page_private(page, get_pageblock_migratetype(page)); 1017 pcp->count++; 1018 if (pcp->count >= pcp->high) { 1019 free_pages_bulk(zone, pcp->batch, &pcp->list, 0); 1020 pcp->count -= pcp->batch; 1021 } 1022 local_irq_restore(flags); 1023 put_cpu(); 1024} 1025 1026void free_hot_page(struct page *page) 1027{ 1028 free_hot_cold_page(page, 0); 1029} 1030 1031void free_cold_page(struct page *page) 1032{ 1033 free_hot_cold_page(page, 1); 1034} 1035 1036/* 1037 * split_page takes a non-compound higher-order page, and splits it into 1038 * n (1<<order) sub-pages: page[0..n] 1039 * Each sub-page must be freed individually. 1040 * 1041 * Note: this is probably too low level an operation for use in drivers. 1042 * Please consult with lkml before using this in your driver. 1043 */ 1044void split_page(struct page *page, unsigned int order) 1045{ 1046 int i; 1047 1048 VM_BUG_ON(PageCompound(page)); 1049 VM_BUG_ON(!page_count(page)); 1050 for (i = 1; i < (1 << order); i++) 1051 set_page_refcounted(page + i); 1052} 1053 1054/* 1055 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 1056 * we cheat by calling it from here, in the order > 0 path. Saves a branch 1057 * or two. 1058 */ 1059static struct page *buffered_rmqueue(struct zone *preferred_zone, 1060 struct zone *zone, int order, gfp_t gfp_flags) 1061{ 1062 unsigned long flags; 1063 struct page *page; 1064 int cold = !!(gfp_flags & __GFP_COLD); 1065 int cpu; 1066 int migratetype = allocflags_to_migratetype(gfp_flags); 1067 1068again: 1069 cpu = get_cpu(); 1070 if (likely(order == 0)) { 1071 struct per_cpu_pages *pcp; 1072 1073 pcp = &zone_pcp(zone, cpu)->pcp; 1074 local_irq_save(flags); 1075 if (!pcp->count) { 1076 pcp->count = rmqueue_bulk(zone, 0, 1077 pcp->batch, &pcp->list, migratetype); 1078 if (unlikely(!pcp->count)) 1079 goto failed; 1080 } 1081 1082 /* Find a page of the appropriate migrate type */ 1083 if (cold) { 1084 list_for_each_entry_reverse(page, &pcp->list, lru) 1085 if (page_private(page) == migratetype) 1086 break; 1087 } else { 1088 list_for_each_entry(page, &pcp->list, lru) 1089 if (page_private(page) == migratetype) 1090 break; 1091 } 1092 1093 /* Allocate more to the pcp list if necessary */ 1094 if (unlikely(&page->lru == &pcp->list)) { 1095 pcp->count += rmqueue_bulk(zone, 0, 1096 pcp->batch, &pcp->list, migratetype); 1097 page = list_entry(pcp->list.next, struct page, lru); 1098 } 1099 1100 list_del(&page->lru); 1101 pcp->count--; 1102 } else { 1103 spin_lock_irqsave(&zone->lock, flags); 1104 page = __rmqueue(zone, order, migratetype); 1105 spin_unlock(&zone->lock); 1106 if (!page) 1107 goto failed; 1108 } 1109 1110 __count_zone_vm_events(PGALLOC, zone, 1 << order); 1111 zone_statistics(preferred_zone, zone); 1112 local_irq_restore(flags); 1113 put_cpu(); 1114 1115 VM_BUG_ON(bad_range(zone, page)); 1116 if (prep_new_page(page, order, gfp_flags)) 1117 goto again; 1118 return page; 1119 1120failed: 1121 local_irq_restore(flags); 1122 put_cpu(); 1123 return NULL; 1124} 1125 1126#define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */ 1127#define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */ 1128#define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */ 1129#define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */ 1130#define ALLOC_HARDER 0x10 /* try to alloc harder */ 1131#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 1132#define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 1133 1134#ifdef CONFIG_FAIL_PAGE_ALLOC 1135 1136static struct fail_page_alloc_attr { 1137 struct fault_attr attr; 1138 1139 u32 ignore_gfp_highmem; 1140 u32 ignore_gfp_wait; 1141 u32 min_order; 1142 1143#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1144 1145 struct dentry *ignore_gfp_highmem_file; 1146 struct dentry *ignore_gfp_wait_file; 1147 struct dentry *min_order_file; 1148 1149#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1150 1151} fail_page_alloc = { 1152 .attr = FAULT_ATTR_INITIALIZER, 1153 .ignore_gfp_wait = 1, 1154 .ignore_gfp_highmem = 1, 1155 .min_order = 1, 1156}; 1157 1158static int __init setup_fail_page_alloc(char *str) 1159{ 1160 return setup_fault_attr(&fail_page_alloc.attr, str); 1161} 1162__setup("fail_page_alloc=", setup_fail_page_alloc); 1163 1164static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1165{ 1166 if (order < fail_page_alloc.min_order) 1167 return 0; 1168 if (gfp_mask & __GFP_NOFAIL) 1169 return 0; 1170 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 1171 return 0; 1172 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) 1173 return 0; 1174 1175 return should_fail(&fail_page_alloc.attr, 1 << order); 1176} 1177 1178#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1179 1180static int __init fail_page_alloc_debugfs(void) 1181{ 1182 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; 1183 struct dentry *dir; 1184 int err; 1185 1186 err = init_fault_attr_dentries(&fail_page_alloc.attr, 1187 "fail_page_alloc"); 1188 if (err) 1189 return err; 1190 dir = fail_page_alloc.attr.dentries.dir; 1191 1192 fail_page_alloc.ignore_gfp_wait_file = 1193 debugfs_create_bool("ignore-gfp-wait", mode, dir, 1194 &fail_page_alloc.ignore_gfp_wait); 1195 1196 fail_page_alloc.ignore_gfp_highmem_file = 1197 debugfs_create_bool("ignore-gfp-highmem", mode, dir, 1198 &fail_page_alloc.ignore_gfp_highmem); 1199 fail_page_alloc.min_order_file = 1200 debugfs_create_u32("min-order", mode, dir, 1201 &fail_page_alloc.min_order); 1202 1203 if (!fail_page_alloc.ignore_gfp_wait_file || 1204 !fail_page_alloc.ignore_gfp_highmem_file || 1205 !fail_page_alloc.min_order_file) { 1206 err = -ENOMEM; 1207 debugfs_remove(fail_page_alloc.ignore_gfp_wait_file); 1208 debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file); 1209 debugfs_remove(fail_page_alloc.min_order_file); 1210 cleanup_fault_attr_dentries(&fail_page_alloc.attr); 1211 } 1212 1213 return err; 1214} 1215 1216late_initcall(fail_page_alloc_debugfs); 1217 1218#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1219 1220#else /* CONFIG_FAIL_PAGE_ALLOC */ 1221 1222static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1223{ 1224 return 0; 1225} 1226 1227#endif /* CONFIG_FAIL_PAGE_ALLOC */ 1228 1229/* 1230 * Return 1 if free pages are above 'mark'. This takes into account the order 1231 * of the allocation. 1232 */ 1233int zone_watermark_ok(struct zone *z, int order, unsigned long mark, 1234 int classzone_idx, int alloc_flags) 1235{ 1236 /* free_pages my go negative - that's OK */ 1237 long min = mark; 1238 long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1; 1239 int o; 1240 1241 if (alloc_flags & ALLOC_HIGH) 1242 min -= min / 2; 1243 if (alloc_flags & ALLOC_HARDER) 1244 min -= min / 4; 1245 1246 if (free_pages <= min + z->lowmem_reserve[classzone_idx]) 1247 return 0; 1248 for (o = 0; o < order; o++) { 1249 /* At the next order, this order's pages become unavailable */ 1250 free_pages -= z->free_area[o].nr_free << o; 1251 1252 /* Require fewer higher order pages to be free */ 1253 min >>= 1; 1254 1255 if (free_pages <= min) 1256 return 0; 1257 } 1258 return 1; 1259} 1260 1261#ifdef CONFIG_NUMA 1262/* 1263 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to 1264 * skip over zones that are not allowed by the cpuset, or that have 1265 * been recently (in last second) found to be nearly full. See further 1266 * comments in mmzone.h. Reduces cache footprint of zonelist scans 1267 * that have to skip over a lot of full or unallowed zones. 1268 * 1269 * If the zonelist cache is present in the passed in zonelist, then 1270 * returns a pointer to the allowed node mask (either the current 1271 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].) 1272 * 1273 * If the zonelist cache is not available for this zonelist, does 1274 * nothing and returns NULL. 1275 * 1276 * If the fullzones BITMAP in the zonelist cache is stale (more than 1277 * a second since last zap'd) then we zap it out (clear its bits.) 1278 * 1279 * We hold off even calling zlc_setup, until after we've checked the 1280 * first zone in the zonelist, on the theory that most allocations will 1281 * be satisfied from that first zone, so best to examine that zone as 1282 * quickly as we can. 1283 */ 1284static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1285{ 1286 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1287 nodemask_t *allowednodes; /* zonelist_cache approximation */ 1288 1289 zlc = zonelist->zlcache_ptr; 1290 if (!zlc) 1291 return NULL; 1292 1293 if (time_after(jiffies, zlc->last_full_zap + HZ)) { 1294 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1295 zlc->last_full_zap = jiffies; 1296 } 1297 1298 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? 1299 &cpuset_current_mems_allowed : 1300 &node_states[N_HIGH_MEMORY]; 1301 return allowednodes; 1302} 1303 1304/* 1305 * Given 'z' scanning a zonelist, run a couple of quick checks to see 1306 * if it is worth looking at further for free memory: 1307 * 1) Check that the zone isn't thought to be full (doesn't have its 1308 * bit set in the zonelist_cache fullzones BITMAP). 1309 * 2) Check that the zones node (obtained from the zonelist_cache 1310 * z_to_n[] mapping) is allowed in the passed in allowednodes mask. 1311 * Return true (non-zero) if zone is worth looking at further, or 1312 * else return false (zero) if it is not. 1313 * 1314 * This check -ignores- the distinction between various watermarks, 1315 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is 1316 * found to be full for any variation of these watermarks, it will 1317 * be considered full for up to one second by all requests, unless 1318 * we are so low on memory on all allowed nodes that we are forced 1319 * into the second scan of the zonelist. 1320 * 1321 * In the second scan we ignore this zonelist cache and exactly 1322 * apply the watermarks to all zones, even it is slower to do so. 1323 * We are low on memory in the second scan, and should leave no stone 1324 * unturned looking for a free page. 1325 */ 1326static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1327 nodemask_t *allowednodes) 1328{ 1329 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1330 int i; /* index of *z in zonelist zones */ 1331 int n; /* node that zone *z is on */ 1332 1333 zlc = zonelist->zlcache_ptr; 1334 if (!zlc) 1335 return 1; 1336 1337 i = z - zonelist->_zonerefs; 1338 n = zlc->z_to_n[i]; 1339 1340 /* This zone is worth trying if it is allowed but not full */ 1341 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); 1342} 1343 1344/* 1345 * Given 'z' scanning a zonelist, set the corresponding bit in 1346 * zlc->fullzones, so that subsequent attempts to allocate a page 1347 * from that zone don't waste time re-examining it. 1348 */ 1349static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1350{ 1351 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1352 int i; /* index of *z in zonelist zones */ 1353 1354 zlc = zonelist->zlcache_ptr; 1355 if (!zlc) 1356 return; 1357 1358 i = z - zonelist->_zonerefs; 1359 1360 set_bit(i, zlc->fullzones); 1361} 1362 1363#else /* CONFIG_NUMA */ 1364 1365static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1366{ 1367 return NULL; 1368} 1369 1370static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1371 nodemask_t *allowednodes) 1372{ 1373 return 1; 1374} 1375 1376static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1377{ 1378} 1379#endif /* CONFIG_NUMA */ 1380 1381/* 1382 * get_page_from_freelist goes through the zonelist trying to allocate 1383 * a page. 1384 */ 1385static struct page * 1386get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order, 1387 struct zonelist *zonelist, int high_zoneidx, int alloc_flags) 1388{ 1389 struct zoneref *z; 1390 struct page *page = NULL; 1391 int classzone_idx; 1392 struct zone *zone, *preferred_zone; 1393 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ 1394 int zlc_active = 0; /* set if using zonelist_cache */ 1395 int did_zlc_setup = 0; /* just call zlc_setup() one time */ 1396 1397 (void)first_zones_zonelist(zonelist, high_zoneidx, nodemask, 1398 &preferred_zone); 1399 if (!preferred_zone) 1400 return NULL; 1401 1402 classzone_idx = zone_idx(preferred_zone); 1403 1404zonelist_scan: 1405 /* 1406 * Scan zonelist, looking for a zone with enough free. 1407 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1408 */ 1409 for_each_zone_zonelist_nodemask(zone, z, zonelist, 1410 high_zoneidx, nodemask) { 1411 if (NUMA_BUILD && zlc_active && 1412 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 1413 continue; 1414 if ((alloc_flags & ALLOC_CPUSET) && 1415 !cpuset_zone_allowed_softwall(zone, gfp_mask)) 1416 goto try_next_zone; 1417 1418 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { 1419 unsigned long mark; 1420 if (alloc_flags & ALLOC_WMARK_MIN) 1421 mark = zone->pages_min; 1422 else if (alloc_flags & ALLOC_WMARK_LOW) 1423 mark = zone->pages_low; 1424 else 1425 mark = zone->pages_high; 1426 if (!zone_watermark_ok(zone, order, mark, 1427 classzone_idx, alloc_flags)) { 1428 if (!zone_reclaim_mode || 1429 !zone_reclaim(zone, gfp_mask, order)) 1430 goto this_zone_full; 1431 } 1432 } 1433 1434 page = buffered_rmqueue(preferred_zone, zone, order, gfp_mask); 1435 if (page) 1436 break; 1437this_zone_full: 1438 if (NUMA_BUILD) 1439 zlc_mark_zone_full(zonelist, z); 1440try_next_zone: 1441 if (NUMA_BUILD && !did_zlc_setup) { 1442 /* we do zlc_setup after the first zone is tried */ 1443 allowednodes = zlc_setup(zonelist, alloc_flags); 1444 zlc_active = 1; 1445 did_zlc_setup = 1; 1446 } 1447 } 1448 1449 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) { 1450 /* Disable zlc cache for second zonelist scan */ 1451 zlc_active = 0; 1452 goto zonelist_scan; 1453 } 1454 return page; 1455} 1456 1457/* 1458 * This is the 'heart' of the zoned buddy allocator. 1459 */ 1460struct page * 1461__alloc_pages_internal(gfp_t gfp_mask, unsigned int order, 1462 struct zonelist *zonelist, nodemask_t *nodemask) 1463{ 1464 const gfp_t wait = gfp_mask & __GFP_WAIT; 1465 enum zone_type high_zoneidx = gfp_zone(gfp_mask); 1466 struct zoneref *z; 1467 struct zone *zone; 1468 struct page *page; 1469 struct reclaim_state reclaim_state; 1470 struct task_struct *p = current; 1471 int do_retry; 1472 int alloc_flags; 1473 unsigned long did_some_progress; 1474 unsigned long pages_reclaimed = 0; 1475 1476 lockdep_trace_alloc(gfp_mask); 1477 1478 might_sleep_if(wait); 1479 1480 if (should_fail_alloc_page(gfp_mask, order)) 1481 return NULL; 1482 1483restart: 1484 z = zonelist->_zonerefs; /* the list of zones suitable for gfp_mask */ 1485 1486 if (unlikely(!z->zone)) { 1487 /* 1488 * Happens if we have an empty zonelist as a result of 1489 * GFP_THISNODE being used on a memoryless node 1490 */ 1491 return NULL; 1492 } 1493 1494 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order, 1495 zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET); 1496 if (page) 1497 goto got_pg; 1498 1499 /* 1500 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and 1501 * __GFP_NOWARN set) should not cause reclaim since the subsystem 1502 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim 1503 * using a larger set of nodes after it has established that the 1504 * allowed per node queues are empty and that nodes are 1505 * over allocated. 1506 */ 1507 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) 1508 goto nopage; 1509 1510 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) 1511 wakeup_kswapd(zone, order); 1512 1513 /* 1514 * OK, we're below the kswapd watermark and have kicked background 1515 * reclaim. Now things get more complex, so set up alloc_flags according 1516 * to how we want to proceed. 1517 * 1518 * The caller may dip into page reserves a bit more if the caller 1519 * cannot run direct reclaim, or if the caller has realtime scheduling 1520 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will 1521 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). 1522 */ 1523 alloc_flags = ALLOC_WMARK_MIN; 1524 if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait) 1525 alloc_flags |= ALLOC_HARDER; 1526 if (gfp_mask & __GFP_HIGH) 1527 alloc_flags |= ALLOC_HIGH; 1528 if (wait) 1529 alloc_flags |= ALLOC_CPUSET; 1530 1531 /* 1532 * Go through the zonelist again. Let __GFP_HIGH and allocations 1533 * coming from realtime tasks go deeper into reserves. 1534 * 1535 * This is the last chance, in general, before the goto nopage. 1536 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. 1537 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1538 */ 1539 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, 1540 high_zoneidx, alloc_flags); 1541 if (page) 1542 goto got_pg; 1543 1544 /* This allocation should allow future memory freeing. */ 1545 1546rebalance: 1547 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) 1548 && !in_interrupt()) { 1549 if (!(gfp_mask & __GFP_NOMEMALLOC)) { 1550nofail_alloc: 1551 /* go through the zonelist yet again, ignoring mins */ 1552 page = get_page_from_freelist(gfp_mask, nodemask, order, 1553 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS); 1554 if (page) 1555 goto got_pg; 1556 if (gfp_mask & __GFP_NOFAIL) { 1557 congestion_wait(WRITE, HZ/50); 1558 goto nofail_alloc; 1559 } 1560 } 1561 goto nopage; 1562 } 1563 1564 /* Atomic allocations - we can't balance anything */ 1565 if (!wait) 1566 goto nopage; 1567 1568 cond_resched(); 1569 1570 /* We now go into synchronous reclaim */ 1571 cpuset_memory_pressure_bump(); 1572 1573 p->flags |= PF_MEMALLOC; 1574 1575 lockdep_set_current_reclaim_state(gfp_mask); 1576 reclaim_state.reclaimed_slab = 0; 1577 p->reclaim_state = &reclaim_state; 1578 1579 did_some_progress = try_to_free_pages(zonelist, order, 1580 gfp_mask, nodemask); 1581 1582 p->reclaim_state = NULL; 1583 lockdep_clear_current_reclaim_state(); 1584 p->flags &= ~PF_MEMALLOC; 1585 1586 cond_resched(); 1587 1588 if (order != 0) 1589 drain_all_pages(); 1590 1591 if (likely(did_some_progress)) { 1592 page = get_page_from_freelist(gfp_mask, nodemask, order, 1593 zonelist, high_zoneidx, alloc_flags); 1594 if (page) 1595 goto got_pg; 1596 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { 1597 if (!try_set_zone_oom(zonelist, gfp_mask)) { 1598 schedule_timeout_uninterruptible(1); 1599 goto restart; 1600 } 1601 1602 /* 1603 * Go through the zonelist yet one more time, keep 1604 * very high watermark here, this is only to catch 1605 * a parallel oom killing, we must fail if we're still 1606 * under heavy pressure. 1607 */ 1608 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, 1609 order, zonelist, high_zoneidx, 1610 ALLOC_WMARK_HIGH|ALLOC_CPUSET); 1611 if (page) { 1612 clear_zonelist_oom(zonelist, gfp_mask); 1613 goto got_pg; 1614 } 1615 1616 /* The OOM killer will not help higher order allocs so fail */ 1617 if (order > PAGE_ALLOC_COSTLY_ORDER) { 1618 clear_zonelist_oom(zonelist, gfp_mask); 1619 goto nopage; 1620 } 1621 1622 out_of_memory(zonelist, gfp_mask, order); 1623 clear_zonelist_oom(zonelist, gfp_mask); 1624 goto restart; 1625 } 1626 1627 /* 1628 * Don't let big-order allocations loop unless the caller explicitly 1629 * requests that. Wait for some write requests to complete then retry. 1630 * 1631 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER 1632 * means __GFP_NOFAIL, but that may not be true in other 1633 * implementations. 1634 * 1635 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is 1636 * specified, then we retry until we no longer reclaim any pages 1637 * (above), or we've reclaimed an order of pages at least as 1638 * large as the allocation's order. In both cases, if the 1639 * allocation still fails, we stop retrying. 1640 */ 1641 pages_reclaimed += did_some_progress; 1642 do_retry = 0; 1643 if (!(gfp_mask & __GFP_NORETRY)) { 1644 if (order <= PAGE_ALLOC_COSTLY_ORDER) { 1645 do_retry = 1; 1646 } else { 1647 if (gfp_mask & __GFP_REPEAT && 1648 pages_reclaimed < (1 << order)) 1649 do_retry = 1; 1650 } 1651 if (gfp_mask & __GFP_NOFAIL) 1652 do_retry = 1; 1653 } 1654 if (do_retry) { 1655 congestion_wait(WRITE, HZ/50); 1656 goto rebalance; 1657 } 1658 1659nopage: 1660 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { 1661 printk(KERN_WARNING "%s: page allocation failure." 1662 " order:%d, mode:0x%x\n", 1663 p->comm, order, gfp_mask); 1664 dump_stack(); 1665 show_mem(); 1666 } 1667got_pg: 1668 return page; 1669} 1670EXPORT_SYMBOL(__alloc_pages_internal); 1671 1672/* 1673 * Common helper functions. 1674 */ 1675unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 1676{ 1677 struct page * page; 1678 page = alloc_pages(gfp_mask, order); 1679 if (!page) 1680 return 0; 1681 return (unsigned long) page_address(page); 1682} 1683 1684EXPORT_SYMBOL(__get_free_pages); 1685 1686unsigned long get_zeroed_page(gfp_t gfp_mask) 1687{ 1688 struct page * page; 1689 1690 /* 1691 * get_zeroed_page() returns a 32-bit address, which cannot represent 1692 * a highmem page 1693 */ 1694 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 1695 1696 page = alloc_pages(gfp_mask | __GFP_ZERO, 0); 1697 if (page) 1698 return (unsigned long) page_address(page); 1699 return 0; 1700} 1701 1702EXPORT_SYMBOL(get_zeroed_page); 1703 1704void __pagevec_free(struct pagevec *pvec) 1705{ 1706 int i = pagevec_count(pvec); 1707 1708 while (--i >= 0) 1709 free_hot_cold_page(pvec->pages[i], pvec->cold); 1710} 1711 1712void __free_pages(struct page *page, unsigned int order) 1713{ 1714 if (put_page_testzero(page)) { 1715 if (order == 0) 1716 free_hot_page(page); 1717 else 1718 __free_pages_ok(page, order); 1719 } 1720} 1721 1722EXPORT_SYMBOL(__free_pages); 1723 1724void free_pages(unsigned long addr, unsigned int order) 1725{ 1726 if (addr != 0) { 1727 VM_BUG_ON(!virt_addr_valid((void *)addr)); 1728 __free_pages(virt_to_page((void *)addr), order); 1729 } 1730} 1731 1732EXPORT_SYMBOL(free_pages); 1733 1734/** 1735 * alloc_pages_exact - allocate an exact number physically-contiguous pages. 1736 * @size: the number of bytes to allocate 1737 * @gfp_mask: GFP flags for the allocation 1738 * 1739 * This function is similar to alloc_pages(), except that it allocates the 1740 * minimum number of pages to satisfy the request. alloc_pages() can only 1741 * allocate memory in power-of-two pages. 1742 * 1743 * This function is also limited by MAX_ORDER. 1744 * 1745 * Memory allocated by this function must be released by free_pages_exact(). 1746 */ 1747void *alloc_pages_exact(size_t size, gfp_t gfp_mask) 1748{ 1749 unsigned int order = get_order(size); 1750 unsigned long addr; 1751 1752 addr = __get_free_pages(gfp_mask, order); 1753 if (addr) { 1754 unsigned long alloc_end = addr + (PAGE_SIZE << order); 1755 unsigned long used = addr + PAGE_ALIGN(size); 1756 1757 split_page(virt_to_page(addr), order); 1758 while (used < alloc_end) { 1759 free_page(used); 1760 used += PAGE_SIZE; 1761 } 1762 } 1763 1764 return (void *)addr; 1765} 1766EXPORT_SYMBOL(alloc_pages_exact); 1767 1768/** 1769 * free_pages_exact - release memory allocated via alloc_pages_exact() 1770 * @virt: the value returned by alloc_pages_exact. 1771 * @size: size of allocation, same value as passed to alloc_pages_exact(). 1772 * 1773 * Release the memory allocated by a previous call to alloc_pages_exact. 1774 */ 1775void free_pages_exact(void *virt, size_t size) 1776{ 1777 unsigned long addr = (unsigned long)virt; 1778 unsigned long end = addr + PAGE_ALIGN(size); 1779 1780 while (addr < end) { 1781 free_page(addr); 1782 addr += PAGE_SIZE; 1783 } 1784} 1785EXPORT_SYMBOL(free_pages_exact); 1786 1787static unsigned int nr_free_zone_pages(int offset) 1788{ 1789 struct zoneref *z; 1790 struct zone *zone; 1791 1792 /* Just pick one node, since fallback list is circular */ 1793 unsigned int sum = 0; 1794 1795 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); 1796 1797 for_each_zone_zonelist(zone, z, zonelist, offset) { 1798 unsigned long size = zone->present_pages; 1799 unsigned long high = zone->pages_high; 1800 if (size > high) 1801 sum += size - high; 1802 } 1803 1804 return sum; 1805} 1806 1807/* 1808 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL 1809 */ 1810unsigned int nr_free_buffer_pages(void) 1811{ 1812 return nr_free_zone_pages(gfp_zone(GFP_USER)); 1813} 1814EXPORT_SYMBOL_GPL(nr_free_buffer_pages); 1815 1816/* 1817 * Amount of free RAM allocatable within all zones 1818 */ 1819unsigned int nr_free_pagecache_pages(void) 1820{ 1821 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); 1822} 1823 1824static inline void show_node(struct zone *zone) 1825{ 1826 if (NUMA_BUILD) 1827 printk("Node %d ", zone_to_nid(zone)); 1828} 1829 1830void si_meminfo(struct sysinfo *val) 1831{ 1832 val->totalram = totalram_pages; 1833 val->sharedram = 0; 1834 val->freeram = global_page_state(NR_FREE_PAGES); 1835 val->bufferram = nr_blockdev_pages(); 1836 val->totalhigh = totalhigh_pages; 1837 val->freehigh = nr_free_highpages(); 1838 val->mem_unit = PAGE_SIZE; 1839} 1840 1841EXPORT_SYMBOL(si_meminfo); 1842 1843#ifdef CONFIG_NUMA 1844void si_meminfo_node(struct sysinfo *val, int nid) 1845{ 1846 pg_data_t *pgdat = NODE_DATA(nid); 1847 1848 val->totalram = pgdat->node_present_pages; 1849 val->freeram = node_page_state(nid, NR_FREE_PAGES); 1850#ifdef CONFIG_HIGHMEM 1851 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; 1852 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], 1853 NR_FREE_PAGES); 1854#else 1855 val->totalhigh = 0; 1856 val->freehigh = 0; 1857#endif 1858 val->mem_unit = PAGE_SIZE; 1859} 1860#endif 1861 1862#define K(x) ((x) << (PAGE_SHIFT-10)) 1863 1864/* 1865 * Show free area list (used inside shift_scroll-lock stuff) 1866 * We also calculate the percentage fragmentation. We do this by counting the 1867 * memory on each free list with the exception of the first item on the list. 1868 */ 1869void show_free_areas(void) 1870{ 1871 int cpu; 1872 struct zone *zone; 1873 1874 for_each_populated_zone(zone) { 1875 show_node(zone); 1876 printk("%s per-cpu:\n", zone->name); 1877 1878 for_each_online_cpu(cpu) { 1879 struct per_cpu_pageset *pageset; 1880 1881 pageset = zone_pcp(zone, cpu); 1882 1883 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n", 1884 cpu, pageset->pcp.high, 1885 pageset->pcp.batch, pageset->pcp.count); 1886 } 1887 } 1888 1889 printk("Active_anon:%lu active_file:%lu inactive_anon:%lu\n" 1890 " inactive_file:%lu" 1891//TODO: check/adjust line lengths 1892#ifdef CONFIG_UNEVICTABLE_LRU 1893 " unevictable:%lu" 1894#endif 1895 " dirty:%lu writeback:%lu unstable:%lu\n" 1896 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n", 1897 global_page_state(NR_ACTIVE_ANON), 1898 global_page_state(NR_ACTIVE_FILE), 1899 global_page_state(NR_INACTIVE_ANON), 1900 global_page_state(NR_INACTIVE_FILE), 1901#ifdef CONFIG_UNEVICTABLE_LRU 1902 global_page_state(NR_UNEVICTABLE), 1903#endif 1904 global_page_state(NR_FILE_DIRTY), 1905 global_page_state(NR_WRITEBACK), 1906 global_page_state(NR_UNSTABLE_NFS), 1907 global_page_state(NR_FREE_PAGES), 1908 global_page_state(NR_SLAB_RECLAIMABLE) + 1909 global_page_state(NR_SLAB_UNRECLAIMABLE), 1910 global_page_state(NR_FILE_MAPPED), 1911 global_page_state(NR_PAGETABLE), 1912 global_page_state(NR_BOUNCE)); 1913 1914 for_each_populated_zone(zone) { 1915 int i; 1916 1917 show_node(zone); 1918 printk("%s" 1919 " free:%lukB" 1920 " min:%lukB" 1921 " low:%lukB" 1922 " high:%lukB" 1923 " active_anon:%lukB" 1924 " inactive_anon:%lukB" 1925 " active_file:%lukB" 1926 " inactive_file:%lukB" 1927#ifdef CONFIG_UNEVICTABLE_LRU 1928 " unevictable:%lukB" 1929#endif 1930 " present:%lukB" 1931 " pages_scanned:%lu" 1932 " all_unreclaimable? %s" 1933 "\n", 1934 zone->name, 1935 K(zone_page_state(zone, NR_FREE_PAGES)), 1936 K(zone->pages_min), 1937 K(zone->pages_low), 1938 K(zone->pages_high), 1939 K(zone_page_state(zone, NR_ACTIVE_ANON)), 1940 K(zone_page_state(zone, NR_INACTIVE_ANON)), 1941 K(zone_page_state(zone, NR_ACTIVE_FILE)), 1942 K(zone_page_state(zone, NR_INACTIVE_FILE)), 1943#ifdef CONFIG_UNEVICTABLE_LRU 1944 K(zone_page_state(zone, NR_UNEVICTABLE)), 1945#endif 1946 K(zone->present_pages), 1947 zone->pages_scanned, 1948 (zone_is_all_unreclaimable(zone) ? "yes" : "no") 1949 ); 1950 printk("lowmem_reserve[]:"); 1951 for (i = 0; i < MAX_NR_ZONES; i++) 1952 printk(" %lu", zone->lowmem_reserve[i]); 1953 printk("\n"); 1954 } 1955 1956 for_each_populated_zone(zone) { 1957 unsigned long nr[MAX_ORDER], flags, order, total = 0; 1958 1959 show_node(zone); 1960 printk("%s: ", zone->name); 1961 1962 spin_lock_irqsave(&zone->lock, flags); 1963 for (order = 0; order < MAX_ORDER; order++) { 1964 nr[order] = zone->free_area[order].nr_free; 1965 total += nr[order] << order; 1966 } 1967 spin_unlock_irqrestore(&zone->lock, flags); 1968 for (order = 0; order < MAX_ORDER; order++) 1969 printk("%lu*%lukB ", nr[order], K(1UL) << order); 1970 printk("= %lukB\n", K(total)); 1971 } 1972 1973 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES)); 1974 1975 show_swap_cache_info(); 1976} 1977 1978static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) 1979{ 1980 zoneref->zone = zone; 1981 zoneref->zone_idx = zone_idx(zone); 1982} 1983 1984/* 1985 * Builds allocation fallback zone lists. 1986 * 1987 * Add all populated zones of a node to the zonelist. 1988 */ 1989static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, 1990 int nr_zones, enum zone_type zone_type) 1991{ 1992 struct zone *zone; 1993 1994 BUG_ON(zone_type >= MAX_NR_ZONES); 1995 zone_type++; 1996 1997 do { 1998 zone_type--; 1999 zone = pgdat->node_zones + zone_type; 2000 if (populated_zone(zone)) { 2001 zoneref_set_zone(zone, 2002 &zonelist->_zonerefs[nr_zones++]); 2003 check_highest_zone(zone_type); 2004 } 2005 2006 } while (zone_type); 2007 return nr_zones; 2008} 2009 2010 2011/* 2012 * zonelist_order: 2013 * 0 = automatic detection of better ordering. 2014 * 1 = order by ([node] distance, -zonetype) 2015 * 2 = order by (-zonetype, [node] distance) 2016 * 2017 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create 2018 * the same zonelist. So only NUMA can configure this param. 2019 */ 2020#define ZONELIST_ORDER_DEFAULT 0 2021#define ZONELIST_ORDER_NODE 1 2022#define ZONELIST_ORDER_ZONE 2 2023 2024/* zonelist order in the kernel. 2025 * set_zonelist_order() will set this to NODE or ZONE. 2026 */ 2027static int current_zonelist_order = ZONELIST_ORDER_DEFAULT; 2028static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"}; 2029 2030 2031#ifdef CONFIG_NUMA 2032/* The value user specified ....changed by config */ 2033static int user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2034/* string for sysctl */ 2035#define NUMA_ZONELIST_ORDER_LEN 16 2036char numa_zonelist_order[16] = "default"; 2037 2038/* 2039 * interface for configure zonelist ordering. 2040 * command line option "numa_zonelist_order" 2041 * = "[dD]efault - default, automatic configuration. 2042 * = "[nN]ode - order by node locality, then by zone within node 2043 * = "[zZ]one - order by zone, then by locality within zone 2044 */ 2045 2046static int __parse_numa_zonelist_order(char *s) 2047{ 2048 if (*s == 'd' || *s == 'D') { 2049 user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2050 } else if (*s == 'n' || *s == 'N') { 2051 user_zonelist_order = ZONELIST_ORDER_NODE; 2052 } else if (*s == 'z' || *s == 'Z') { 2053 user_zonelist_order = ZONELIST_ORDER_ZONE; 2054 } else { 2055 printk(KERN_WARNING 2056 "Ignoring invalid numa_zonelist_order value: " 2057 "%s\n", s); 2058 return -EINVAL; 2059 } 2060 return 0; 2061} 2062 2063static __init int setup_numa_zonelist_order(char *s) 2064{ 2065 if (s) 2066 return __parse_numa_zonelist_order(s); 2067 return 0; 2068} 2069early_param("numa_zonelist_order", setup_numa_zonelist_order); 2070 2071/* 2072 * sysctl handler for numa_zonelist_order 2073 */ 2074int numa_zonelist_order_handler(ctl_table *table, int write, 2075 struct file *file, void __user *buffer, size_t *length, 2076 loff_t *ppos) 2077{ 2078 char saved_string[NUMA_ZONELIST_ORDER_LEN]; 2079 int ret; 2080 2081 if (write) 2082 strncpy(saved_string, (char*)table->data, 2083 NUMA_ZONELIST_ORDER_LEN); 2084 ret = proc_dostring(table, write, file, buffer, length, ppos); 2085 if (ret) 2086 return ret; 2087 if (write) { 2088 int oldval = user_zonelist_order; 2089 if (__parse_numa_zonelist_order((char*)table->data)) { 2090 /* 2091 * bogus value. restore saved string 2092 */ 2093 strncpy((char*)table->data, saved_string, 2094 NUMA_ZONELIST_ORDER_LEN); 2095 user_zonelist_order = oldval; 2096 } else if (oldval != user_zonelist_order) 2097 build_all_zonelists(); 2098 } 2099 return 0; 2100} 2101 2102 2103#define MAX_NODE_LOAD (num_online_nodes()) 2104static int node_load[MAX_NUMNODES]; 2105 2106/** 2107 * find_next_best_node - find the next node that should appear in a given node's fallback list 2108 * @node: node whose fallback list we're appending 2109 * @used_node_mask: nodemask_t of already used nodes 2110 * 2111 * We use a number of factors to determine which is the next node that should 2112 * appear on a given node's fallback list. The node should not have appeared 2113 * already in @node's fallback list, and it should be the next closest node 2114 * according to the distance array (which contains arbitrary distance values 2115 * from each node to each node in the system), and should also prefer nodes 2116 * with no CPUs, since presumably they'll have very little allocation pressure 2117 * on them otherwise. 2118 * It returns -1 if no node is found. 2119 */ 2120static int find_next_best_node(int node, nodemask_t *used_node_mask) 2121{ 2122 int n, val; 2123 int min_val = INT_MAX; 2124 int best_node = -1; 2125 const struct cpumask *tmp = cpumask_of_node(0); 2126 2127 /* Use the local node if we haven't already */ 2128 if (!node_isset(node, *used_node_mask)) { 2129 node_set(node, *used_node_mask); 2130 return node; 2131 } 2132 2133 for_each_node_state(n, N_HIGH_MEMORY) { 2134 2135 /* Don't want a node to appear more than once */ 2136 if (node_isset(n, *used_node_mask)) 2137 continue; 2138 2139 /* Use the distance array to find the distance */ 2140 val = node_distance(node, n); 2141 2142 /* Penalize nodes under us ("prefer the next node") */ 2143 val += (n < node); 2144 2145 /* Give preference to headless and unused nodes */ 2146 tmp = cpumask_of_node(n); 2147 if (!cpumask_empty(tmp)) 2148 val += PENALTY_FOR_NODE_WITH_CPUS; 2149 2150 /* Slight preference for less loaded node */ 2151 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 2152 val += node_load[n]; 2153 2154 if (val < min_val) { 2155 min_val = val; 2156 best_node = n; 2157 } 2158 } 2159 2160 if (best_node >= 0) 2161 node_set(best_node, *used_node_mask); 2162 2163 return best_node; 2164} 2165 2166 2167/* 2168 * Build zonelists ordered by node and zones within node. 2169 * This results in maximum locality--normal zone overflows into local 2170 * DMA zone, if any--but risks exhausting DMA zone. 2171 */ 2172static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) 2173{ 2174 int j; 2175 struct zonelist *zonelist; 2176 2177 zonelist = &pgdat->node_zonelists[0]; 2178 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++) 2179 ; 2180 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2181 MAX_NR_ZONES - 1); 2182 zonelist->_zonerefs[j].zone = NULL; 2183 zonelist->_zonerefs[j].zone_idx = 0; 2184} 2185 2186/* 2187 * Build gfp_thisnode zonelists 2188 */ 2189static void build_thisnode_zonelists(pg_data_t *pgdat) 2190{ 2191 int j; 2192 struct zonelist *zonelist; 2193 2194 zonelist = &pgdat->node_zonelists[1]; 2195 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2196 zonelist->_zonerefs[j].zone = NULL; 2197 zonelist->_zonerefs[j].zone_idx = 0; 2198} 2199 2200/* 2201 * Build zonelists ordered by zone and nodes within zones. 2202 * This results in conserving DMA zone[s] until all Normal memory is 2203 * exhausted, but results in overflowing to remote node while memory 2204 * may still exist in local DMA zone. 2205 */ 2206static int node_order[MAX_NUMNODES]; 2207 2208static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) 2209{ 2210 int pos, j, node; 2211 int zone_type; /* needs to be signed */ 2212 struct zone *z; 2213 struct zonelist *zonelist; 2214 2215 zonelist = &pgdat->node_zonelists[0]; 2216 pos = 0; 2217 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) { 2218 for (j = 0; j < nr_nodes; j++) { 2219 node = node_order[j]; 2220 z = &NODE_DATA(node)->node_zones[zone_type]; 2221 if (populated_zone(z)) { 2222 zoneref_set_zone(z, 2223 &zonelist->_zonerefs[pos++]); 2224 check_highest_zone(zone_type); 2225 } 2226 } 2227 } 2228 zonelist->_zonerefs[pos].zone = NULL; 2229 zonelist->_zonerefs[pos].zone_idx = 0; 2230} 2231 2232static int default_zonelist_order(void) 2233{ 2234 int nid, zone_type; 2235 unsigned long low_kmem_size,total_size; 2236 struct zone *z; 2237 int average_size; 2238 /* 2239 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem. 2240 * If they are really small and used heavily, the system can fall 2241 * into OOM very easily. 2242 * This function detect ZONE_DMA/DMA32 size and confgigures zone order. 2243 */ 2244 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */ 2245 low_kmem_size = 0; 2246 total_size = 0; 2247 for_each_online_node(nid) { 2248 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2249 z = &NODE_DATA(nid)->node_zones[zone_type]; 2250 if (populated_zone(z)) { 2251 if (zone_type < ZONE_NORMAL) 2252 low_kmem_size += z->present_pages; 2253 total_size += z->present_pages; 2254 } 2255 } 2256 } 2257 if (!low_kmem_size || /* there are no DMA area. */ 2258 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */ 2259 return ZONELIST_ORDER_NODE; 2260 /* 2261 * look into each node's config. 2262 * If there is a node whose DMA/DMA32 memory is very big area on 2263 * local memory, NODE_ORDER may be suitable. 2264 */ 2265 average_size = total_size / 2266 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1); 2267 for_each_online_node(nid) { 2268 low_kmem_size = 0; 2269 total_size = 0; 2270 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2271 z = &NODE_DATA(nid)->node_zones[zone_type]; 2272 if (populated_zone(z)) { 2273 if (zone_type < ZONE_NORMAL) 2274 low_kmem_size += z->present_pages; 2275 total_size += z->present_pages; 2276 } 2277 } 2278 if (low_kmem_size && 2279 total_size > average_size && /* ignore small node */ 2280 low_kmem_size > total_size * 70/100) 2281 return ZONELIST_ORDER_NODE; 2282 } 2283 return ZONELIST_ORDER_ZONE; 2284} 2285 2286static void set_zonelist_order(void) 2287{ 2288 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT) 2289 current_zonelist_order = default_zonelist_order(); 2290 else 2291 current_zonelist_order = user_zonelist_order; 2292} 2293 2294static void build_zonelists(pg_data_t *pgdat) 2295{ 2296 int j, node, load; 2297 enum zone_type i; 2298 nodemask_t used_mask; 2299 int local_node, prev_node; 2300 struct zonelist *zonelist; 2301 int order = current_zonelist_order; 2302 2303 /* initialize zonelists */ 2304 for (i = 0; i < MAX_ZONELISTS; i++) { 2305 zonelist = pgdat->node_zonelists + i; 2306 zonelist->_zonerefs[0].zone = NULL; 2307 zonelist->_zonerefs[0].zone_idx = 0; 2308 } 2309 2310 /* NUMA-aware ordering of nodes */ 2311 local_node = pgdat->node_id; 2312 load = num_online_nodes(); 2313 prev_node = local_node; 2314 nodes_clear(used_mask); 2315 2316 memset(node_load, 0, sizeof(node_load)); 2317 memset(node_order, 0, sizeof(node_order)); 2318 j = 0; 2319 2320 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 2321 int distance = node_distance(local_node, node); 2322 2323 /* 2324 * If another node is sufficiently far away then it is better 2325 * to reclaim pages in a zone before going off node. 2326 */ 2327 if (distance > RECLAIM_DISTANCE) 2328 zone_reclaim_mode = 1; 2329 2330 /* 2331 * We don't want to pressure a particular node. 2332 * So adding penalty to the first node in same 2333 * distance group to make it round-robin. 2334 */ 2335 if (distance != node_distance(local_node, prev_node)) 2336 node_load[node] = load; 2337 2338 prev_node = node; 2339 load--; 2340 if (order == ZONELIST_ORDER_NODE) 2341 build_zonelists_in_node_order(pgdat, node); 2342 else 2343 node_order[j++] = node; /* remember order */ 2344 } 2345 2346 if (order == ZONELIST_ORDER_ZONE) { 2347 /* calculate node order -- i.e., DMA last! */ 2348 build_zonelists_in_zone_order(pgdat, j); 2349 } 2350 2351 build_thisnode_zonelists(pgdat); 2352} 2353 2354/* Construct the zonelist performance cache - see further mmzone.h */ 2355static void build_zonelist_cache(pg_data_t *pgdat) 2356{ 2357 struct zonelist *zonelist; 2358 struct zonelist_cache *zlc; 2359 struct zoneref *z; 2360 2361 zonelist = &pgdat->node_zonelists[0]; 2362 zonelist->zlcache_ptr = zlc = &zonelist->zlcache; 2363 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 2364 for (z = zonelist->_zonerefs; z->zone; z++) 2365 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z); 2366} 2367 2368 2369#else /* CONFIG_NUMA */ 2370 2371static void set_zonelist_order(void) 2372{ 2373 current_zonelist_order = ZONELIST_ORDER_ZONE; 2374} 2375 2376static void build_zonelists(pg_data_t *pgdat) 2377{ 2378 int node, local_node; 2379 enum zone_type j; 2380 struct zonelist *zonelist; 2381 2382 local_node = pgdat->node_id; 2383 2384 zonelist = &pgdat->node_zonelists[0]; 2385 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2386 2387 /* 2388 * Now we build the zonelist so that it contains the zones 2389 * of all the other nodes. 2390 * We don't want to pressure a particular node, so when 2391 * building the zones for node N, we make sure that the 2392 * zones coming right after the local ones are those from 2393 * node N+1 (modulo N) 2394 */ 2395 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 2396 if (!node_online(node)) 2397 continue; 2398 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2399 MAX_NR_ZONES - 1); 2400 } 2401 for (node = 0; node < local_node; node++) { 2402 if (!node_online(node)) 2403 continue; 2404 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2405 MAX_NR_ZONES - 1); 2406 } 2407 2408 zonelist->_zonerefs[j].zone = NULL; 2409 zonelist->_zonerefs[j].zone_idx = 0; 2410} 2411 2412/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ 2413static void build_zonelist_cache(pg_data_t *pgdat) 2414{ 2415 pgdat->node_zonelists[0].zlcache_ptr = NULL; 2416} 2417 2418#endif /* CONFIG_NUMA */ 2419 2420/* return values int ....just for stop_machine() */ 2421static int __build_all_zonelists(void *dummy) 2422{ 2423 int nid; 2424 2425 for_each_online_node(nid) { 2426 pg_data_t *pgdat = NODE_DATA(nid); 2427 2428 build_zonelists(pgdat); 2429 build_zonelist_cache(pgdat); 2430 } 2431 return 0; 2432} 2433 2434void build_all_zonelists(void) 2435{ 2436 set_zonelist_order(); 2437 2438 if (system_state == SYSTEM_BOOTING) { 2439 __build_all_zonelists(NULL); 2440 mminit_verify_zonelist(); 2441 cpuset_init_current_mems_allowed(); 2442 } else { 2443 /* we have to stop all cpus to guarantee there is no user 2444 of zonelist */ 2445 stop_machine(__build_all_zonelists, NULL, NULL); 2446 /* cpuset refresh routine should be here */ 2447 } 2448 vm_total_pages = nr_free_pagecache_pages(); 2449 /* 2450 * Disable grouping by mobility if the number of pages in the 2451 * system is too low to allow the mechanism to work. It would be 2452 * more accurate, but expensive to check per-zone. This check is 2453 * made on memory-hotadd so a system can start with mobility 2454 * disabled and enable it later 2455 */ 2456 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) 2457 page_group_by_mobility_disabled = 1; 2458 else 2459 page_group_by_mobility_disabled = 0; 2460 2461 printk("Built %i zonelists in %s order, mobility grouping %s. " 2462 "Total pages: %ld\n", 2463 num_online_nodes(), 2464 zonelist_order_name[current_zonelist_order], 2465 page_group_by_mobility_disabled ? "off" : "on", 2466 vm_total_pages); 2467#ifdef CONFIG_NUMA 2468 printk("Policy zone: %s\n", zone_names[policy_zone]); 2469#endif 2470} 2471 2472/* 2473 * Helper functions to size the waitqueue hash table. 2474 * Essentially these want to choose hash table sizes sufficiently 2475 * large so that collisions trying to wait on pages are rare. 2476 * But in fact, the number of active page waitqueues on typical 2477 * systems is ridiculously low, less than 200. So this is even 2478 * conservative, even though it seems large. 2479 * 2480 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 2481 * waitqueues, i.e. the size of the waitq table given the number of pages. 2482 */ 2483#define PAGES_PER_WAITQUEUE 256 2484 2485#ifndef CONFIG_MEMORY_HOTPLUG 2486static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2487{ 2488 unsigned long size = 1; 2489 2490 pages /= PAGES_PER_WAITQUEUE; 2491 2492 while (size < pages) 2493 size <<= 1; 2494 2495 /* 2496 * Once we have dozens or even hundreds of threads sleeping 2497 * on IO we've got bigger problems than wait queue collision. 2498 * Limit the size of the wait table to a reasonable size. 2499 */ 2500 size = min(size, 4096UL); 2501 2502 return max(size, 4UL); 2503} 2504#else 2505/* 2506 * A zone's size might be changed by hot-add, so it is not possible to determine 2507 * a suitable size for its wait_table. So we use the maximum size now. 2508 * 2509 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: 2510 * 2511 * i386 (preemption config) : 4096 x 16 = 64Kbyte. 2512 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. 2513 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. 2514 * 2515 * The maximum entries are prepared when a zone's memory is (512K + 256) pages 2516 * or more by the traditional way. (See above). It equals: 2517 * 2518 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. 2519 * ia64(16K page size) : = ( 8G + 4M)byte. 2520 * powerpc (64K page size) : = (32G +16M)byte. 2521 */ 2522static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2523{ 2524 return 4096UL; 2525} 2526#endif 2527 2528/* 2529 * This is an integer logarithm so that shifts can be used later 2530 * to extract the more random high bits from the multiplicative 2531 * hash function before the remainder is taken. 2532 */ 2533static inline unsigned long wait_table_bits(unsigned long size) 2534{ 2535 return ffz(~size); 2536} 2537 2538#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) 2539 2540/* 2541 * Mark a number of pageblocks as MIGRATE_RESERVE. The number 2542 * of blocks reserved is based on zone->pages_min. The memory within the 2543 * reserve will tend to store contiguous free pages. Setting min_free_kbytes 2544 * higher will lead to a bigger reserve which will get freed as contiguous 2545 * blocks as reclaim kicks in 2546 */ 2547static void setup_zone_migrate_reserve(struct zone *zone) 2548{ 2549 unsigned long start_pfn, pfn, end_pfn; 2550 struct page *page; 2551 unsigned long reserve, block_migratetype; 2552 2553 /* Get the start pfn, end pfn and the number of blocks to reserve */ 2554 start_pfn = zone->zone_start_pfn; 2555 end_pfn = start_pfn + zone->spanned_pages; 2556 reserve = roundup(zone->pages_min, pageblock_nr_pages) >> 2557 pageblock_order; 2558 2559 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 2560 if (!pfn_valid(pfn)) 2561 continue; 2562 page = pfn_to_page(pfn); 2563 2564 /* Watch out for overlapping nodes */ 2565 if (page_to_nid(page) != zone_to_nid(zone)) 2566 continue; 2567 2568 /* Blocks with reserved pages will never free, skip them. */ 2569 if (PageReserved(page)) 2570 continue; 2571 2572 block_migratetype = get_pageblock_migratetype(page); 2573 2574 /* If this block is reserved, account for it */ 2575 if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) { 2576 reserve--; 2577 continue; 2578 } 2579 2580 /* Suitable for reserving if this block is movable */ 2581 if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) { 2582 set_pageblock_migratetype(page, MIGRATE_RESERVE); 2583 move_freepages_block(zone, page, MIGRATE_RESERVE); 2584 reserve--; 2585 continue; 2586 } 2587 2588 /* 2589 * If the reserve is met and this is a previous reserved block, 2590 * take it back 2591 */ 2592 if (block_migratetype == MIGRATE_RESERVE) { 2593 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 2594 move_freepages_block(zone, page, MIGRATE_MOVABLE); 2595 } 2596 } 2597} 2598 2599/* 2600 * Initially all pages are reserved - free ones are freed 2601 * up by free_all_bootmem() once the early boot process is 2602 * done. Non-atomic initialization, single-pass. 2603 */ 2604void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 2605 unsigned long start_pfn, enum memmap_context context) 2606{ 2607 struct page *page; 2608 unsigned long end_pfn = start_pfn + size; 2609 unsigned long pfn; 2610 struct zone *z; 2611 2612 if (highest_memmap_pfn < end_pfn - 1) 2613 highest_memmap_pfn = end_pfn - 1; 2614 2615 z = &NODE_DATA(nid)->node_zones[zone]; 2616 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 2617 /* 2618 * There can be holes in boot-time mem_map[]s 2619 * handed to this function. They do not 2620 * exist on hotplugged memory. 2621 */ 2622 if (context == MEMMAP_EARLY) { 2623 if (!early_pfn_valid(pfn)) 2624 continue; 2625 if (!early_pfn_in_nid(pfn, nid)) 2626 continue; 2627 } 2628 page = pfn_to_page(pfn); 2629 set_page_links(page, zone, nid, pfn); 2630 mminit_verify_page_links(page, zone, nid, pfn); 2631 init_page_count(page); 2632 reset_page_mapcount(page); 2633 SetPageReserved(page); 2634 /* 2635 * Mark the block movable so that blocks are reserved for 2636 * movable at startup. This will force kernel allocations 2637 * to reserve their blocks rather than leaking throughout 2638 * the address space during boot when many long-lived 2639 * kernel allocations are made. Later some blocks near 2640 * the start are marked MIGRATE_RESERVE by 2641 * setup_zone_migrate_reserve() 2642 * 2643 * bitmap is created for zone's valid pfn range. but memmap 2644 * can be created for invalid pages (for alignment) 2645 * check here not to call set_pageblock_migratetype() against 2646 * pfn out of zone. 2647 */ 2648 if ((z->zone_start_pfn <= pfn) 2649 && (pfn < z->zone_start_pfn + z->spanned_pages) 2650 && !(pfn & (pageblock_nr_pages - 1))) 2651 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 2652 2653 INIT_LIST_HEAD(&page->lru); 2654#ifdef WANT_PAGE_VIRTUAL 2655 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 2656 if (!is_highmem_idx(zone)) 2657 set_page_address(page, __va(pfn << PAGE_SHIFT)); 2658#endif 2659 } 2660} 2661 2662static void __meminit zone_init_free_lists(struct zone *zone) 2663{ 2664 int order, t; 2665 for_each_migratetype_order(order, t) { 2666 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); 2667 zone->free_area[order].nr_free = 0; 2668 } 2669} 2670 2671#ifndef __HAVE_ARCH_MEMMAP_INIT 2672#define memmap_init(size, nid, zone, start_pfn) \ 2673 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) 2674#endif 2675 2676static int zone_batchsize(struct zone *zone) 2677{ 2678#ifdef CONFIG_MMU 2679 int batch; 2680 2681 /* 2682 * The per-cpu-pages pools are set to around 1000th of the 2683 * size of the zone. But no more than 1/2 of a meg. 2684 * 2685 * OK, so we don't know how big the cache is. So guess. 2686 */ 2687 batch = zone->present_pages / 1024; 2688 if (batch * PAGE_SIZE > 512 * 1024) 2689 batch = (512 * 1024) / PAGE_SIZE; 2690 batch /= 4; /* We effectively *= 4 below */ 2691 if (batch < 1) 2692 batch = 1; 2693 2694 /* 2695 * Clamp the batch to a 2^n - 1 value. Having a power 2696 * of 2 value was found to be more likely to have 2697 * suboptimal cache aliasing properties in some cases. 2698 * 2699 * For example if 2 tasks are alternately allocating 2700 * batches of pages, one task can end up with a lot 2701 * of pages of one half of the possible page colors 2702 * and the other with pages of the other colors. 2703 */ 2704 batch = rounddown_pow_of_two(batch + batch/2) - 1; 2705 2706 return batch; 2707 2708#else 2709 /* The deferral and batching of frees should be suppressed under NOMMU 2710 * conditions. 2711 * 2712 * The problem is that NOMMU needs to be able to allocate large chunks 2713 * of contiguous memory as there's no hardware page translation to 2714 * assemble apparent contiguous memory from discontiguous pages. 2715 * 2716 * Queueing large contiguous runs of pages for batching, however, 2717 * causes the pages to actually be freed in smaller chunks. As there 2718 * can be a significant delay between the individual batches being 2719 * recycled, this leads to the once large chunks of space being 2720 * fragmented and becoming unavailable for high-order allocations. 2721 */ 2722 return 0; 2723#endif 2724} 2725 2726static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 2727{ 2728 struct per_cpu_pages *pcp; 2729 2730 memset(p, 0, sizeof(*p)); 2731 2732 pcp = &p->pcp; 2733 pcp->count = 0; 2734 pcp->high = 6 * batch; 2735 pcp->batch = max(1UL, 1 * batch); 2736 INIT_LIST_HEAD(&pcp->list); 2737} 2738 2739/* 2740 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist 2741 * to the value high for the pageset p. 2742 */ 2743 2744static void setup_pagelist_highmark(struct per_cpu_pageset *p, 2745 unsigned long high) 2746{ 2747 struct per_cpu_pages *pcp; 2748 2749 pcp = &p->pcp; 2750 pcp->high = high; 2751 pcp->batch = max(1UL, high/4); 2752 if ((high/4) > (PAGE_SHIFT * 8)) 2753 pcp->batch = PAGE_SHIFT * 8; 2754} 2755 2756 2757#ifdef CONFIG_NUMA 2758/* 2759 * Boot pageset table. One per cpu which is going to be used for all 2760 * zones and all nodes. The parameters will be set in such a way 2761 * that an item put on a list will immediately be handed over to 2762 * the buddy list. This is safe since pageset manipulation is done 2763 * with interrupts disabled. 2764 * 2765 * Some NUMA counter updates may also be caught by the boot pagesets. 2766 * 2767 * The boot_pagesets must be kept even after bootup is complete for 2768 * unused processors and/or zones. They do play a role for bootstrapping 2769 * hotplugged processors. 2770 * 2771 * zoneinfo_show() and maybe other functions do 2772 * not check if the processor is online before following the pageset pointer. 2773 * Other parts of the kernel may not check if the zone is available. 2774 */ 2775static struct per_cpu_pageset boot_pageset[NR_CPUS]; 2776 2777/* 2778 * Dynamically allocate memory for the 2779 * per cpu pageset array in struct zone. 2780 */ 2781static int __cpuinit process_zones(int cpu) 2782{ 2783 struct zone *zone, *dzone; 2784 int node = cpu_to_node(cpu); 2785 2786 node_set_state(node, N_CPU); /* this node has a cpu */ 2787 2788 for_each_populated_zone(zone) { 2789 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset), 2790 GFP_KERNEL, node); 2791 if (!zone_pcp(zone, cpu)) 2792 goto bad; 2793 2794 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone)); 2795 2796 if (percpu_pagelist_fraction) 2797 setup_pagelist_highmark(zone_pcp(zone, cpu), 2798 (zone->present_pages / percpu_pagelist_fraction)); 2799 } 2800 2801 return 0; 2802bad: 2803 for_each_zone(dzone) { 2804 if (!populated_zone(dzone)) 2805 continue; 2806 if (dzone == zone) 2807 break; 2808 kfree(zone_pcp(dzone, cpu)); 2809 zone_pcp(dzone, cpu) = NULL; 2810 } 2811 return -ENOMEM; 2812} 2813 2814static inline void free_zone_pagesets(int cpu) 2815{ 2816 struct zone *zone; 2817 2818 for_each_zone(zone) { 2819 struct per_cpu_pageset *pset = zone_pcp(zone, cpu); 2820 2821 /* Free per_cpu_pageset if it is slab allocated */ 2822 if (pset != &boot_pageset[cpu]) 2823 kfree(pset); 2824 zone_pcp(zone, cpu) = NULL; 2825 } 2826} 2827 2828static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb, 2829 unsigned long action, 2830 void *hcpu) 2831{ 2832 int cpu = (long)hcpu; 2833 int ret = NOTIFY_OK; 2834 2835 switch (action) { 2836 case CPU_UP_PREPARE: 2837 case CPU_UP_PREPARE_FROZEN: 2838 if (process_zones(cpu)) 2839 ret = NOTIFY_BAD; 2840 break; 2841 case CPU_UP_CANCELED: 2842 case CPU_UP_CANCELED_FROZEN: 2843 case CPU_DEAD: 2844 case CPU_DEAD_FROZEN: 2845 free_zone_pagesets(cpu); 2846 break; 2847 default: 2848 break; 2849 } 2850 return ret; 2851} 2852 2853static struct notifier_block __cpuinitdata pageset_notifier = 2854 { &pageset_cpuup_callback, NULL, 0 }; 2855 2856void __init setup_per_cpu_pageset(void) 2857{ 2858 int err; 2859 2860 /* Initialize per_cpu_pageset for cpu 0. 2861 * A cpuup callback will do this for every cpu 2862 * as it comes online 2863 */ 2864 err = process_zones(smp_processor_id()); 2865 BUG_ON(err); 2866 register_cpu_notifier(&pageset_notifier); 2867} 2868 2869#endif 2870 2871static noinline __init_refok 2872int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 2873{ 2874 int i; 2875 struct pglist_data *pgdat = zone->zone_pgdat; 2876 size_t alloc_size; 2877 2878 /* 2879 * The per-page waitqueue mechanism uses hashed waitqueues 2880 * per zone. 2881 */ 2882 zone->wait_table_hash_nr_entries = 2883 wait_table_hash_nr_entries(zone_size_pages); 2884 zone->wait_table_bits = 2885 wait_table_bits(zone->wait_table_hash_nr_entries); 2886 alloc_size = zone->wait_table_hash_nr_entries 2887 * sizeof(wait_queue_head_t); 2888 2889 if (!slab_is_available()) { 2890 zone->wait_table = (wait_queue_head_t *) 2891 alloc_bootmem_node(pgdat, alloc_size); 2892 } else { 2893 /* 2894 * This case means that a zone whose size was 0 gets new memory 2895 * via memory hot-add. 2896 * But it may be the case that a new node was hot-added. In 2897 * this case vmalloc() will not be able to use this new node's 2898 * memory - this wait_table must be initialized to use this new 2899 * node itself as well. 2900 * To use this new node's memory, further consideration will be 2901 * necessary. 2902 */ 2903 zone->wait_table = vmalloc(alloc_size); 2904 } 2905 if (!zone->wait_table) 2906 return -ENOMEM; 2907 2908 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i) 2909 init_waitqueue_head(zone->wait_table + i); 2910 2911 return 0; 2912} 2913 2914static __meminit void zone_pcp_init(struct zone *zone) 2915{ 2916 int cpu; 2917 unsigned long batch = zone_batchsize(zone); 2918 2919 for (cpu = 0; cpu < NR_CPUS; cpu++) { 2920#ifdef CONFIG_NUMA 2921 /* Early boot. Slab allocator not functional yet */ 2922 zone_pcp(zone, cpu) = &boot_pageset[cpu]; 2923 setup_pageset(&boot_pageset[cpu],0); 2924#else 2925 setup_pageset(zone_pcp(zone,cpu), batch); 2926#endif 2927 } 2928 if (zone->present_pages) 2929 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", 2930 zone->name, zone->present_pages, batch); 2931} 2932 2933__meminit int init_currently_empty_zone(struct zone *zone, 2934 unsigned long zone_start_pfn, 2935 unsigned long size, 2936 enum memmap_context context) 2937{ 2938 struct pglist_data *pgdat = zone->zone_pgdat; 2939 int ret; 2940 ret = zone_wait_table_init(zone, size); 2941 if (ret) 2942 return ret; 2943 pgdat->nr_zones = zone_idx(zone) + 1; 2944 2945 zone->zone_start_pfn = zone_start_pfn; 2946 2947 mminit_dprintk(MMINIT_TRACE, "memmap_init", 2948 "Initialising map node %d zone %lu pfns %lu -> %lu\n", 2949 pgdat->node_id, 2950 (unsigned long)zone_idx(zone), 2951 zone_start_pfn, (zone_start_pfn + size)); 2952 2953 zone_init_free_lists(zone); 2954 2955 return 0; 2956} 2957 2958#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 2959/* 2960 * Basic iterator support. Return the first range of PFNs for a node 2961 * Note: nid == MAX_NUMNODES returns first region regardless of node 2962 */ 2963static int __meminit first_active_region_index_in_nid(int nid) 2964{ 2965 int i; 2966 2967 for (i = 0; i < nr_nodemap_entries; i++) 2968 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid) 2969 return i; 2970 2971 return -1; 2972} 2973 2974/* 2975 * Basic iterator support. Return the next active range of PFNs for a node 2976 * Note: nid == MAX_NUMNODES returns next region regardless of node 2977 */ 2978static int __meminit next_active_region_index_in_nid(int index, int nid) 2979{ 2980 for (index = index + 1; index < nr_nodemap_entries; index++) 2981 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid) 2982 return index; 2983 2984 return -1; 2985} 2986 2987#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID 2988/* 2989 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. 2990 * Architectures may implement their own version but if add_active_range() 2991 * was used and there are no special requirements, this is a convenient 2992 * alternative 2993 */ 2994int __meminit __early_pfn_to_nid(unsigned long pfn) 2995{ 2996 int i; 2997 2998 for (i = 0; i < nr_nodemap_entries; i++) { 2999 unsigned long start_pfn = early_node_map[i].start_pfn; 3000 unsigned long end_pfn = early_node_map[i].end_pfn; 3001 3002 if (start_pfn <= pfn && pfn < end_pfn) 3003 return early_node_map[i].nid; 3004 } 3005 /* This is a memory hole */ 3006 return -1; 3007} 3008#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ 3009 3010int __meminit early_pfn_to_nid(unsigned long pfn) 3011{ 3012 int nid; 3013 3014 nid = __early_pfn_to_nid(pfn); 3015 if (nid >= 0) 3016 return nid; 3017 /* just returns 0 */ 3018 return 0; 3019} 3020 3021#ifdef CONFIG_NODES_SPAN_OTHER_NODES 3022bool __meminit early_pfn_in_nid(unsigned long pfn, int node) 3023{ 3024 int nid; 3025 3026 nid = __early_pfn_to_nid(pfn); 3027 if (nid >= 0 && nid != node) 3028 return false; 3029 return true; 3030} 3031#endif 3032 3033/* Basic iterator support to walk early_node_map[] */ 3034#define for_each_active_range_index_in_nid(i, nid) \ 3035 for (i = first_active_region_index_in_nid(nid); i != -1; \ 3036 i = next_active_region_index_in_nid(i, nid)) 3037 3038/** 3039 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range 3040 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. 3041 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node 3042 * 3043 * If an architecture guarantees that all ranges registered with 3044 * add_active_ranges() contain no holes and may be freed, this 3045 * this function may be used instead of calling free_bootmem() manually. 3046 */ 3047void __init free_bootmem_with_active_regions(int nid, 3048 unsigned long max_low_pfn) 3049{ 3050 int i; 3051 3052 for_each_active_range_index_in_nid(i, nid) { 3053 unsigned long size_pages = 0; 3054 unsigned long end_pfn = early_node_map[i].end_pfn; 3055 3056 if (early_node_map[i].start_pfn >= max_low_pfn) 3057 continue; 3058 3059 if (end_pfn > max_low_pfn) 3060 end_pfn = max_low_pfn; 3061 3062 size_pages = end_pfn - early_node_map[i].start_pfn; 3063 free_bootmem_node(NODE_DATA(early_node_map[i].nid), 3064 PFN_PHYS(early_node_map[i].start_pfn), 3065 size_pages << PAGE_SHIFT); 3066 } 3067} 3068 3069void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data) 3070{ 3071 int i; 3072 int ret; 3073 3074 for_each_active_range_index_in_nid(i, nid) { 3075 ret = work_fn(early_node_map[i].start_pfn, 3076 early_node_map[i].end_pfn, data); 3077 if (ret) 3078 break; 3079 } 3080} 3081/** 3082 * sparse_memory_present_with_active_regions - Call memory_present for each active range 3083 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. 3084 * 3085 * If an architecture guarantees that all ranges registered with 3086 * add_active_ranges() contain no holes and may be freed, this 3087 * function may be used instead of calling memory_present() manually. 3088 */ 3089void __init sparse_memory_present_with_active_regions(int nid) 3090{ 3091 int i; 3092 3093 for_each_active_range_index_in_nid(i, nid) 3094 memory_present(early_node_map[i].nid, 3095 early_node_map[i].start_pfn, 3096 early_node_map[i].end_pfn); 3097} 3098 3099/** 3100 * get_pfn_range_for_nid - Return the start and end page frames for a node 3101 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. 3102 * @start_pfn: Passed by reference. On return, it will have the node start_pfn. 3103 * @end_pfn: Passed by reference. On return, it will have the node end_pfn. 3104 * 3105 * It returns the start and end page frame of a node based on information 3106 * provided by an arch calling add_active_range(). If called for a node 3107 * with no available memory, a warning is printed and the start and end 3108 * PFNs will be 0. 3109 */ 3110void __meminit get_pfn_range_for_nid(unsigned int nid, 3111 unsigned long *start_pfn, unsigned long *end_pfn) 3112{ 3113 int i; 3114 *start_pfn = -1UL; 3115 *end_pfn = 0; 3116 3117 for_each_active_range_index_in_nid(i, nid) { 3118 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn); 3119 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn); 3120 } 3121 3122 if (*start_pfn == -1UL) 3123 *start_pfn = 0; 3124} 3125 3126/* 3127 * This finds a zone that can be used for ZONE_MOVABLE pages. The 3128 * assumption is made that zones within a node are ordered in monotonic 3129 * increasing memory addresses so that the "highest" populated zone is used 3130 */ 3131static void __init find_usable_zone_for_movable(void) 3132{ 3133 int zone_index; 3134 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { 3135 if (zone_index == ZONE_MOVABLE) 3136 continue; 3137 3138 if (arch_zone_highest_possible_pfn[zone_index] > 3139 arch_zone_lowest_possible_pfn[zone_index]) 3140 break; 3141 } 3142 3143 VM_BUG_ON(zone_index == -1); 3144 movable_zone = zone_index; 3145} 3146 3147/* 3148 * The zone ranges provided by the architecture do not include ZONE_MOVABLE 3149 * because it is sized independant of architecture. Unlike the other zones, 3150 * the starting point for ZONE_MOVABLE is not fixed. It may be different 3151 * in each node depending on the size of each node and how evenly kernelcore 3152 * is distributed. This helper function adjusts the zone ranges 3153 * provided by the architecture for a given node by using the end of the 3154 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that 3155 * zones within a node are in order of monotonic increases memory addresses 3156 */ 3157static void __meminit adjust_zone_range_for_zone_movable(int nid, 3158 unsigned long zone_type, 3159 unsigned long node_start_pfn, 3160 unsigned long node_end_pfn, 3161 unsigned long *zone_start_pfn, 3162 unsigned long *zone_end_pfn) 3163{ 3164 /* Only adjust if ZONE_MOVABLE is on this node */ 3165 if (zone_movable_pfn[nid]) { 3166 /* Size ZONE_MOVABLE */ 3167 if (zone_type == ZONE_MOVABLE) { 3168 *zone_start_pfn = zone_movable_pfn[nid]; 3169 *zone_end_pfn = min(node_end_pfn, 3170 arch_zone_highest_possible_pfn[movable_zone]); 3171 3172 /* Adjust for ZONE_MOVABLE starting within this range */ 3173 } else if (*zone_start_pfn < zone_movable_pfn[nid] && 3174 *zone_end_pfn > zone_movable_pfn[nid]) { 3175 *zone_end_pfn = zone_movable_pfn[nid]; 3176 3177 /* Check if this whole range is within ZONE_MOVABLE */ 3178 } else if (*zone_start_pfn >= zone_movable_pfn[nid]) 3179 *zone_start_pfn = *zone_end_pfn; 3180 } 3181} 3182 3183/* 3184 * Return the number of pages a zone spans in a node, including holes 3185 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() 3186 */ 3187static unsigned long __meminit zone_spanned_pages_in_node(int nid, 3188 unsigned long zone_type, 3189 unsigned long *ignored) 3190{ 3191 unsigned long node_start_pfn, node_end_pfn; 3192 unsigned long zone_start_pfn, zone_end_pfn; 3193 3194 /* Get the start and end of the node and zone */ 3195 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3196 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; 3197 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; 3198 adjust_zone_range_for_zone_movable(nid, zone_type, 3199 node_start_pfn, node_end_pfn, 3200 &zone_start_pfn, &zone_end_pfn); 3201 3202 /* Check that this node has pages within the zone's required range */ 3203 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) 3204 return 0; 3205 3206 /* Move the zone boundaries inside the node if necessary */ 3207 zone_end_pfn = min(zone_end_pfn, node_end_pfn); 3208 zone_start_pfn = max(zone_start_pfn, node_start_pfn); 3209 3210 /* Return the spanned pages */ 3211 return zone_end_pfn - zone_start_pfn; 3212} 3213 3214/* 3215 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, 3216 * then all holes in the requested range will be accounted for. 3217 */ 3218static unsigned long __meminit __absent_pages_in_range(int nid, 3219 unsigned long range_start_pfn, 3220 unsigned long range_end_pfn) 3221{ 3222 int i = 0; 3223 unsigned long prev_end_pfn = 0, hole_pages = 0; 3224 unsigned long start_pfn; 3225 3226 /* Find the end_pfn of the first active range of pfns in the node */ 3227 i = first_active_region_index_in_nid(nid); 3228 if (i == -1) 3229 return 0; 3230 3231 prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 3232 3233 /* Account for ranges before physical memory on this node */ 3234 if (early_node_map[i].start_pfn > range_start_pfn) 3235 hole_pages = prev_end_pfn - range_start_pfn; 3236 3237 /* Find all holes for the zone within the node */ 3238 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) { 3239 3240 /* No need to continue if prev_end_pfn is outside the zone */ 3241 if (prev_end_pfn >= range_end_pfn) 3242 break; 3243 3244 /* Make sure the end of the zone is not within the hole */ 3245 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 3246 prev_end_pfn = max(prev_end_pfn, range_start_pfn); 3247 3248 /* Update the hole size cound and move on */ 3249 if (start_pfn > range_start_pfn) { 3250 BUG_ON(prev_end_pfn > start_pfn); 3251 hole_pages += start_pfn - prev_end_pfn; 3252 } 3253 prev_end_pfn = early_node_map[i].end_pfn; 3254 } 3255 3256 /* Account for ranges past physical memory on this node */ 3257 if (range_end_pfn > prev_end_pfn) 3258 hole_pages += range_end_pfn - 3259 max(range_start_pfn, prev_end_pfn); 3260 3261 return hole_pages; 3262} 3263 3264/** 3265 * absent_pages_in_range - Return number of page frames in holes within a range 3266 * @start_pfn: The start PFN to start searching for holes 3267 * @end_pfn: The end PFN to stop searching for holes 3268 * 3269 * It returns the number of pages frames in memory holes within a range. 3270 */ 3271unsigned long __init absent_pages_in_range(unsigned long start_pfn, 3272 unsigned long end_pfn) 3273{ 3274 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); 3275} 3276 3277/* Return the number of page frames in holes in a zone on a node */ 3278static unsigned long __meminit zone_absent_pages_in_node(int nid, 3279 unsigned long zone_type, 3280 unsigned long *ignored) 3281{ 3282 unsigned long node_start_pfn, node_end_pfn; 3283 unsigned long zone_start_pfn, zone_end_pfn; 3284 3285 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3286 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type], 3287 node_start_pfn); 3288 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type], 3289 node_end_pfn); 3290 3291 adjust_zone_range_for_zone_movable(nid, zone_type, 3292 node_start_pfn, node_end_pfn, 3293 &zone_start_pfn, &zone_end_pfn); 3294 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); 3295} 3296 3297#else 3298static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, 3299 unsigned long zone_type, 3300 unsigned long *zones_size) 3301{ 3302 return zones_size[zone_type]; 3303} 3304 3305static inline unsigned long __meminit zone_absent_pages_in_node(int nid, 3306 unsigned long zone_type, 3307 unsigned long *zholes_size) 3308{ 3309 if (!zholes_size) 3310 return 0; 3311 3312 return zholes_size[zone_type]; 3313} 3314 3315#endif 3316 3317static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, 3318 unsigned long *zones_size, unsigned long *zholes_size) 3319{ 3320 unsigned long realtotalpages, totalpages = 0; 3321 enum zone_type i; 3322 3323 for (i = 0; i < MAX_NR_ZONES; i++) 3324 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i, 3325 zones_size); 3326 pgdat->node_spanned_pages = totalpages; 3327 3328 realtotalpages = totalpages; 3329 for (i = 0; i < MAX_NR_ZONES; i++) 3330 realtotalpages -= 3331 zone_absent_pages_in_node(pgdat->node_id, i, 3332 zholes_size); 3333 pgdat->node_present_pages = realtotalpages; 3334 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, 3335 realtotalpages); 3336} 3337 3338#ifndef CONFIG_SPARSEMEM 3339/* 3340 * Calculate the size of the zone->blockflags rounded to an unsigned long 3341 * Start by making sure zonesize is a multiple of pageblock_order by rounding 3342 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally 3343 * round what is now in bits to nearest long in bits, then return it in 3344 * bytes. 3345 */ 3346static unsigned long __init usemap_size(unsigned long zonesize) 3347{ 3348 unsigned long usemapsize; 3349 3350 usemapsize = roundup(zonesize, pageblock_nr_pages); 3351 usemapsize = usemapsize >> pageblock_order; 3352 usemapsize *= NR_PAGEBLOCK_BITS; 3353 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); 3354 3355 return usemapsize / 8; 3356} 3357 3358static void __init setup_usemap(struct pglist_data *pgdat, 3359 struct zone *zone, unsigned long zonesize) 3360{ 3361 unsigned long usemapsize = usemap_size(zonesize); 3362 zone->pageblock_flags = NULL; 3363 if (usemapsize) 3364 zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize); 3365} 3366#else 3367static void inline setup_usemap(struct pglist_data *pgdat, 3368 struct zone *zone, unsigned long zonesize) {} 3369#endif /* CONFIG_SPARSEMEM */ 3370 3371#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 3372 3373/* Return a sensible default order for the pageblock size. */ 3374static inline int pageblock_default_order(void) 3375{ 3376 if (HPAGE_SHIFT > PAGE_SHIFT) 3377 return HUGETLB_PAGE_ORDER; 3378 3379 return MAX_ORDER-1; 3380} 3381 3382/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ 3383static inline void __init set_pageblock_order(unsigned int order) 3384{ 3385 /* Check that pageblock_nr_pages has not already been setup */ 3386 if (pageblock_order) 3387 return; 3388 3389 /* 3390 * Assume the largest contiguous order of interest is a huge page. 3391 * This value may be variable depending on boot parameters on IA64 3392 */ 3393 pageblock_order = order; 3394} 3395#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 3396 3397/* 3398 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() 3399 * and pageblock_default_order() are unused as pageblock_order is set 3400 * at compile-time. See include/linux/pageblock-flags.h for the values of 3401 * pageblock_order based on the kernel config 3402 */ 3403static inline int pageblock_default_order(unsigned int order) 3404{ 3405 return MAX_ORDER-1; 3406} 3407#define set_pageblock_order(x) do {} while (0) 3408 3409#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 3410 3411/* 3412 * Set up the zone data structures: 3413 * - mark all pages reserved 3414 * - mark all memory queues empty 3415 * - clear the memory bitmaps 3416 */ 3417static void __paginginit free_area_init_core(struct pglist_data *pgdat, 3418 unsigned long *zones_size, unsigned long *zholes_size) 3419{ 3420 enum zone_type j; 3421 int nid = pgdat->node_id; 3422 unsigned long zone_start_pfn = pgdat->node_start_pfn; 3423 int ret; 3424 3425 pgdat_resize_init(pgdat); 3426 pgdat->nr_zones = 0; 3427 init_waitqueue_head(&pgdat->kswapd_wait); 3428 pgdat->kswapd_max_order = 0; 3429 pgdat_page_cgroup_init(pgdat); 3430 3431 for (j = 0; j < MAX_NR_ZONES; j++) { 3432 struct zone *zone = pgdat->node_zones + j; 3433 unsigned long size, realsize, memmap_pages; 3434 enum lru_list l; 3435 3436 size = zone_spanned_pages_in_node(nid, j, zones_size); 3437 realsize = size - zone_absent_pages_in_node(nid, j, 3438 zholes_size); 3439 3440 /* 3441 * Adjust realsize so that it accounts for how much memory 3442 * is used by this zone for memmap. This affects the watermark 3443 * and per-cpu initialisations 3444 */ 3445 memmap_pages = 3446 PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT; 3447 if (realsize >= memmap_pages) { 3448 realsize -= memmap_pages; 3449 if (memmap_pages) 3450 printk(KERN_DEBUG 3451 " %s zone: %lu pages used for memmap\n", 3452 zone_names[j], memmap_pages); 3453 } else 3454 printk(KERN_WARNING 3455 " %s zone: %lu pages exceeds realsize %lu\n", 3456 zone_names[j], memmap_pages, realsize); 3457 3458 /* Account for reserved pages */ 3459 if (j == 0 && realsize > dma_reserve) { 3460 realsize -= dma_reserve; 3461 printk(KERN_DEBUG " %s zone: %lu pages reserved\n", 3462 zone_names[0], dma_reserve); 3463 } 3464 3465 if (!is_highmem_idx(j)) 3466 nr_kernel_pages += realsize; 3467 nr_all_pages += realsize; 3468 3469 zone->spanned_pages = size; 3470 zone->present_pages = realsize; 3471#ifdef CONFIG_NUMA 3472 zone->node = nid; 3473 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio) 3474 / 100; 3475 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100; 3476#endif 3477 zone->name = zone_names[j]; 3478 spin_lock_init(&zone->lock); 3479 spin_lock_init(&zone->lru_lock); 3480 zone_seqlock_init(zone); 3481 zone->zone_pgdat = pgdat; 3482 3483 zone->prev_priority = DEF_PRIORITY; 3484 3485 zone_pcp_init(zone); 3486 for_each_lru(l) { 3487 INIT_LIST_HEAD(&zone->lru[l].list); 3488 zone->lru[l].nr_scan = 0; 3489 } 3490 zone->reclaim_stat.recent_rotated[0] = 0; 3491 zone->reclaim_stat.recent_rotated[1] = 0; 3492 zone->reclaim_stat.recent_scanned[0] = 0; 3493 zone->reclaim_stat.recent_scanned[1] = 0; 3494 zap_zone_vm_stats(zone); 3495 zone->flags = 0; 3496 if (!size) 3497 continue; 3498 3499 set_pageblock_order(pageblock_default_order()); 3500 setup_usemap(pgdat, zone, size); 3501 ret = init_currently_empty_zone(zone, zone_start_pfn, 3502 size, MEMMAP_EARLY); 3503 BUG_ON(ret); 3504 memmap_init(size, nid, j, zone_start_pfn); 3505 zone_start_pfn += size; 3506 } 3507} 3508 3509static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat) 3510{ 3511 /* Skip empty nodes */ 3512 if (!pgdat->node_spanned_pages) 3513 return; 3514 3515#ifdef CONFIG_FLAT_NODE_MEM_MAP 3516 /* ia64 gets its own node_mem_map, before this, without bootmem */ 3517 if (!pgdat->node_mem_map) { 3518 unsigned long size, start, end; 3519 struct page *map; 3520 3521 /* 3522 * The zone's endpoints aren't required to be MAX_ORDER 3523 * aligned but the node_mem_map endpoints must be in order 3524 * for the buddy allocator to function correctly. 3525 */ 3526 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); 3527 end = pgdat->node_start_pfn + pgdat->node_spanned_pages; 3528 end = ALIGN(end, MAX_ORDER_NR_PAGES); 3529 size = (end - start) * sizeof(struct page); 3530 map = alloc_remap(pgdat->node_id, size); 3531 if (!map) 3532 map = alloc_bootmem_node(pgdat, size); 3533 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); 3534 } 3535#ifndef CONFIG_NEED_MULTIPLE_NODES 3536 /* 3537 * With no DISCONTIG, the global mem_map is just set as node 0's 3538 */ 3539 if (pgdat == NODE_DATA(0)) { 3540 mem_map = NODE_DATA(0)->node_mem_map; 3541#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3542 if (page_to_pfn(mem_map) != pgdat->node_start_pfn) 3543 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET); 3544#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 3545 } 3546#endif 3547#endif /* CONFIG_FLAT_NODE_MEM_MAP */ 3548} 3549 3550void __paginginit free_area_init_node(int nid, unsigned long *zones_size, 3551 unsigned long node_start_pfn, unsigned long *zholes_size) 3552{ 3553 pg_data_t *pgdat = NODE_DATA(nid); 3554 3555 pgdat->node_id = nid; 3556 pgdat->node_start_pfn = node_start_pfn; 3557 calculate_node_totalpages(pgdat, zones_size, zholes_size); 3558 3559 alloc_node_mem_map(pgdat); 3560#ifdef CONFIG_FLAT_NODE_MEM_MAP 3561 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n", 3562 nid, (unsigned long)pgdat, 3563 (unsigned long)pgdat->node_mem_map); 3564#endif 3565 3566 free_area_init_core(pgdat, zones_size, zholes_size); 3567} 3568 3569#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3570 3571#if MAX_NUMNODES > 1 3572/* 3573 * Figure out the number of possible node ids. 3574 */ 3575static void __init setup_nr_node_ids(void) 3576{ 3577 unsigned int node; 3578 unsigned int highest = 0; 3579 3580 for_each_node_mask(node, node_possible_map) 3581 highest = node; 3582 nr_node_ids = highest + 1; 3583} 3584#else 3585static inline void setup_nr_node_ids(void) 3586{ 3587} 3588#endif 3589 3590/** 3591 * add_active_range - Register a range of PFNs backed by physical memory 3592 * @nid: The node ID the range resides on 3593 * @start_pfn: The start PFN of the available physical memory 3594 * @end_pfn: The end PFN of the available physical memory 3595 * 3596 * These ranges are stored in an early_node_map[] and later used by 3597 * free_area_init_nodes() to calculate zone sizes and holes. If the 3598 * range spans a memory hole, it is up to the architecture to ensure 3599 * the memory is not freed by the bootmem allocator. If possible 3600 * the range being registered will be merged with existing ranges. 3601 */ 3602void __init add_active_range(unsigned int nid, unsigned long start_pfn, 3603 unsigned long end_pfn) 3604{ 3605 int i; 3606 3607 mminit_dprintk(MMINIT_TRACE, "memory_register", 3608 "Entering add_active_range(%d, %#lx, %#lx) " 3609 "%d entries of %d used\n", 3610 nid, start_pfn, end_pfn, 3611 nr_nodemap_entries, MAX_ACTIVE_REGIONS); 3612 3613 mminit_validate_memmodel_limits(&start_pfn, &end_pfn); 3614 3615 /* Merge with existing active regions if possible */ 3616 for (i = 0; i < nr_nodemap_entries; i++) { 3617 if (early_node_map[i].nid != nid) 3618 continue; 3619 3620 /* Skip if an existing region covers this new one */ 3621 if (start_pfn >= early_node_map[i].start_pfn && 3622 end_pfn <= early_node_map[i].end_pfn) 3623 return; 3624 3625 /* Merge forward if suitable */ 3626 if (start_pfn <= early_node_map[i].end_pfn && 3627 end_pfn > early_node_map[i].end_pfn) { 3628 early_node_map[i].end_pfn = end_pfn; 3629 return; 3630 } 3631 3632 /* Merge backward if suitable */ 3633 if (start_pfn < early_node_map[i].end_pfn && 3634 end_pfn >= early_node_map[i].start_pfn) { 3635 early_node_map[i].start_pfn = start_pfn; 3636 return; 3637 } 3638 } 3639 3640 /* Check that early_node_map is large enough */ 3641 if (i >= MAX_ACTIVE_REGIONS) { 3642 printk(KERN_CRIT "More than %d memory regions, truncating\n", 3643 MAX_ACTIVE_REGIONS); 3644 return; 3645 } 3646 3647 early_node_map[i].nid = nid; 3648 early_node_map[i].start_pfn = start_pfn; 3649 early_node_map[i].end_pfn = end_pfn; 3650 nr_nodemap_entries = i + 1; 3651} 3652 3653/** 3654 * remove_active_range - Shrink an existing registered range of PFNs 3655 * @nid: The node id the range is on that should be shrunk 3656 * @start_pfn: The new PFN of the range 3657 * @end_pfn: The new PFN of the range 3658 * 3659 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node. 3660 * The map is kept near the end physical page range that has already been 3661 * registered. This function allows an arch to shrink an existing registered 3662 * range. 3663 */ 3664void __init remove_active_range(unsigned int nid, unsigned long start_pfn, 3665 unsigned long end_pfn) 3666{ 3667 int i, j; 3668 int removed = 0; 3669 3670 printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n", 3671 nid, start_pfn, end_pfn); 3672 3673 /* Find the old active region end and shrink */ 3674 for_each_active_range_index_in_nid(i, nid) { 3675 if (early_node_map[i].start_pfn >= start_pfn && 3676 early_node_map[i].end_pfn <= end_pfn) { 3677 /* clear it */ 3678 early_node_map[i].start_pfn = 0; 3679 early_node_map[i].end_pfn = 0; 3680 removed = 1; 3681 continue; 3682 } 3683 if (early_node_map[i].start_pfn < start_pfn && 3684 early_node_map[i].end_pfn > start_pfn) { 3685 unsigned long temp_end_pfn = early_node_map[i].end_pfn; 3686 early_node_map[i].end_pfn = start_pfn; 3687 if (temp_end_pfn > end_pfn) 3688 add_active_range(nid, end_pfn, temp_end_pfn); 3689 continue; 3690 } 3691 if (early_node_map[i].start_pfn >= start_pfn && 3692 early_node_map[i].end_pfn > end_pfn && 3693 early_node_map[i].start_pfn < end_pfn) { 3694 early_node_map[i].start_pfn = end_pfn; 3695 continue; 3696 } 3697 } 3698 3699 if (!removed) 3700 return; 3701 3702 /* remove the blank ones */ 3703 for (i = nr_nodemap_entries - 1; i > 0; i--) { 3704 if (early_node_map[i].nid != nid) 3705 continue; 3706 if (early_node_map[i].end_pfn) 3707 continue; 3708 /* we found it, get rid of it */ 3709 for (j = i; j < nr_nodemap_entries - 1; j++) 3710 memcpy(&early_node_map[j], &early_node_map[j+1], 3711 sizeof(early_node_map[j])); 3712 j = nr_nodemap_entries - 1; 3713 memset(&early_node_map[j], 0, sizeof(early_node_map[j])); 3714 nr_nodemap_entries--; 3715 } 3716} 3717 3718/** 3719 * remove_all_active_ranges - Remove all currently registered regions 3720 * 3721 * During discovery, it may be found that a table like SRAT is invalid 3722 * and an alternative discovery method must be used. This function removes 3723 * all currently registered regions. 3724 */ 3725void __init remove_all_active_ranges(void) 3726{ 3727 memset(early_node_map, 0, sizeof(early_node_map)); 3728 nr_nodemap_entries = 0; 3729} 3730 3731/* Compare two active node_active_regions */ 3732static int __init cmp_node_active_region(const void *a, const void *b) 3733{ 3734 struct node_active_region *arange = (struct node_active_region *)a; 3735 struct node_active_region *brange = (struct node_active_region *)b; 3736 3737 /* Done this way to avoid overflows */ 3738 if (arange->start_pfn > brange->start_pfn) 3739 return 1; 3740 if (arange->start_pfn < brange->start_pfn) 3741 return -1; 3742 3743 return 0; 3744} 3745 3746/* sort the node_map by start_pfn */ 3747static void __init sort_node_map(void) 3748{ 3749 sort(early_node_map, (size_t)nr_nodemap_entries, 3750 sizeof(struct node_active_region), 3751 cmp_node_active_region, NULL); 3752} 3753 3754/* Find the lowest pfn for a node */ 3755static unsigned long __init find_min_pfn_for_node(int nid) 3756{ 3757 int i; 3758 unsigned long min_pfn = ULONG_MAX; 3759 3760 /* Assuming a sorted map, the first range found has the starting pfn */ 3761 for_each_active_range_index_in_nid(i, nid) 3762 min_pfn = min(min_pfn, early_node_map[i].start_pfn); 3763 3764 if (min_pfn == ULONG_MAX) { 3765 printk(KERN_WARNING 3766 "Could not find start_pfn for node %d\n", nid); 3767 return 0; 3768 } 3769 3770 return min_pfn; 3771} 3772 3773/** 3774 * find_min_pfn_with_active_regions - Find the minimum PFN registered 3775 * 3776 * It returns the minimum PFN based on information provided via 3777 * add_active_range(). 3778 */ 3779unsigned long __init find_min_pfn_with_active_regions(void) 3780{ 3781 return find_min_pfn_for_node(MAX_NUMNODES); 3782} 3783 3784/* 3785 * early_calculate_totalpages() 3786 * Sum pages in active regions for movable zone. 3787 * Populate N_HIGH_MEMORY for calculating usable_nodes. 3788 */ 3789static unsigned long __init early_calculate_totalpages(void) 3790{ 3791 int i; 3792 unsigned long totalpages = 0; 3793 3794 for (i = 0; i < nr_nodemap_entries; i++) { 3795 unsigned long pages = early_node_map[i].end_pfn - 3796 early_node_map[i].start_pfn; 3797 totalpages += pages; 3798 if (pages) 3799 node_set_state(early_node_map[i].nid, N_HIGH_MEMORY); 3800 } 3801 return totalpages; 3802} 3803 3804/* 3805 * Find the PFN the Movable zone begins in each node. Kernel memory 3806 * is spread evenly between nodes as long as the nodes have enough 3807 * memory. When they don't, some nodes will have more kernelcore than 3808 * others 3809 */ 3810static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn) 3811{ 3812 int i, nid; 3813 unsigned long usable_startpfn; 3814 unsigned long kernelcore_node, kernelcore_remaining; 3815 unsigned long totalpages = early_calculate_totalpages(); 3816 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]); 3817 3818 /* 3819 * If movablecore was specified, calculate what size of 3820 * kernelcore that corresponds so that memory usable for 3821 * any allocation type is evenly spread. If both kernelcore 3822 * and movablecore are specified, then the value of kernelcore 3823 * will be used for required_kernelcore if it's greater than 3824 * what movablecore would have allowed. 3825 */ 3826 if (required_movablecore) { 3827 unsigned long corepages; 3828 3829 /* 3830 * Round-up so that ZONE_MOVABLE is at least as large as what 3831 * was requested by the user 3832 */ 3833 required_movablecore = 3834 roundup(required_movablecore, MAX_ORDER_NR_PAGES); 3835 corepages = totalpages - required_movablecore; 3836 3837 required_kernelcore = max(required_kernelcore, corepages); 3838 } 3839 3840 /* If kernelcore was not specified, there is no ZONE_MOVABLE */ 3841 if (!required_kernelcore) 3842 return; 3843 3844 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ 3845 find_usable_zone_for_movable(); 3846 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; 3847 3848restart: 3849 /* Spread kernelcore memory as evenly as possible throughout nodes */ 3850 kernelcore_node = required_kernelcore / usable_nodes; 3851 for_each_node_state(nid, N_HIGH_MEMORY) { 3852 /* 3853 * Recalculate kernelcore_node if the division per node 3854 * now exceeds what is necessary to satisfy the requested 3855 * amount of memory for the kernel 3856 */ 3857 if (required_kernelcore < kernelcore_node) 3858 kernelcore_node = required_kernelcore / usable_nodes; 3859 3860 /* 3861 * As the map is walked, we track how much memory is usable 3862 * by the kernel using kernelcore_remaining. When it is 3863 * 0, the rest of the node is usable by ZONE_MOVABLE 3864 */ 3865 kernelcore_remaining = kernelcore_node; 3866 3867 /* Go through each range of PFNs within this node */ 3868 for_each_active_range_index_in_nid(i, nid) { 3869 unsigned long start_pfn, end_pfn; 3870 unsigned long size_pages; 3871 3872 start_pfn = max(early_node_map[i].start_pfn, 3873 zone_movable_pfn[nid]); 3874 end_pfn = early_node_map[i].end_pfn; 3875 if (start_pfn >= end_pfn) 3876 continue; 3877 3878 /* Account for what is only usable for kernelcore */ 3879 if (start_pfn < usable_startpfn) { 3880 unsigned long kernel_pages; 3881 kernel_pages = min(end_pfn, usable_startpfn) 3882 - start_pfn; 3883 3884 kernelcore_remaining -= min(kernel_pages, 3885 kernelcore_remaining); 3886 required_kernelcore -= min(kernel_pages, 3887 required_kernelcore); 3888 3889 /* Continue if range is now fully accounted */ 3890 if (end_pfn <= usable_startpfn) { 3891 3892 /* 3893 * Push zone_movable_pfn to the end so 3894 * that if we have to rebalance 3895 * kernelcore across nodes, we will 3896 * not double account here 3897 */ 3898 zone_movable_pfn[nid] = end_pfn; 3899 continue; 3900 } 3901 start_pfn = usable_startpfn; 3902 } 3903 3904 /* 3905 * The usable PFN range for ZONE_MOVABLE is from 3906 * start_pfn->end_pfn. Calculate size_pages as the 3907 * number of pages used as kernelcore 3908 */ 3909 size_pages = end_pfn - start_pfn; 3910 if (size_pages > kernelcore_remaining) 3911 size_pages = kernelcore_remaining; 3912 zone_movable_pfn[nid] = start_pfn + size_pages; 3913 3914 /* 3915 * Some kernelcore has been met, update counts and 3916 * break if the kernelcore for this node has been 3917 * satisified 3918 */ 3919 required_kernelcore -= min(required_kernelcore, 3920 size_pages); 3921 kernelcore_remaining -= size_pages; 3922 if (!kernelcore_remaining) 3923 break; 3924 } 3925 } 3926 3927 /* 3928 * If there is still required_kernelcore, we do another pass with one 3929 * less node in the count. This will push zone_movable_pfn[nid] further 3930 * along on the nodes that still have memory until kernelcore is 3931 * satisified 3932 */ 3933 usable_nodes--; 3934 if (usable_nodes && required_kernelcore > usable_nodes) 3935 goto restart; 3936 3937 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ 3938 for (nid = 0; nid < MAX_NUMNODES; nid++) 3939 zone_movable_pfn[nid] = 3940 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); 3941} 3942 3943/* Any regular memory on that node ? */ 3944static void check_for_regular_memory(pg_data_t *pgdat) 3945{ 3946#ifdef CONFIG_HIGHMEM 3947 enum zone_type zone_type; 3948 3949 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) { 3950 struct zone *zone = &pgdat->node_zones[zone_type]; 3951 if (zone->present_pages) 3952 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY); 3953 } 3954#endif 3955} 3956 3957/** 3958 * free_area_init_nodes - Initialise all pg_data_t and zone data 3959 * @max_zone_pfn: an array of max PFNs for each zone 3960 * 3961 * This will call free_area_init_node() for each active node in the system. 3962 * Using the page ranges provided by add_active_range(), the size of each 3963 * zone in each node and their holes is calculated. If the maximum PFN 3964 * between two adjacent zones match, it is assumed that the zone is empty. 3965 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed 3966 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone 3967 * starts where the previous one ended. For example, ZONE_DMA32 starts 3968 * at arch_max_dma_pfn. 3969 */ 3970void __init free_area_init_nodes(unsigned long *max_zone_pfn) 3971{ 3972 unsigned long nid; 3973 int i; 3974 3975 /* Sort early_node_map as initialisation assumes it is sorted */ 3976 sort_node_map(); 3977 3978 /* Record where the zone boundaries are */ 3979 memset(arch_zone_lowest_possible_pfn, 0, 3980 sizeof(arch_zone_lowest_possible_pfn)); 3981 memset(arch_zone_highest_possible_pfn, 0, 3982 sizeof(arch_zone_highest_possible_pfn)); 3983 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); 3984 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; 3985 for (i = 1; i < MAX_NR_ZONES; i++) { 3986 if (i == ZONE_MOVABLE) 3987 continue; 3988 arch_zone_lowest_possible_pfn[i] = 3989 arch_zone_highest_possible_pfn[i-1]; 3990 arch_zone_highest_possible_pfn[i] = 3991 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); 3992 } 3993 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0; 3994 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0; 3995 3996 /* Find the PFNs that ZONE_MOVABLE begins at in each node */ 3997 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); 3998 find_zone_movable_pfns_for_nodes(zone_movable_pfn); 3999 4000 /* Print out the zone ranges */ 4001 printk("Zone PFN ranges:\n"); 4002 for (i = 0; i < MAX_NR_ZONES; i++) { 4003 if (i == ZONE_MOVABLE) 4004 continue; 4005 printk(" %-8s %0#10lx -> %0#10lx\n", 4006 zone_names[i], 4007 arch_zone_lowest_possible_pfn[i], 4008 arch_zone_highest_possible_pfn[i]); 4009 } 4010 4011 /* Print out the PFNs ZONE_MOVABLE begins at in each node */ 4012 printk("Movable zone start PFN for each node\n"); 4013 for (i = 0; i < MAX_NUMNODES; i++) { 4014 if (zone_movable_pfn[i]) 4015 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]); 4016 } 4017 4018 /* Print out the early_node_map[] */ 4019 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries); 4020 for (i = 0; i < nr_nodemap_entries; i++) 4021 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid, 4022 early_node_map[i].start_pfn, 4023 early_node_map[i].end_pfn); 4024 4025 /* Initialise every node */ 4026 mminit_verify_pageflags_layout(); 4027 setup_nr_node_ids(); 4028 for_each_online_node(nid) { 4029 pg_data_t *pgdat = NODE_DATA(nid); 4030 free_area_init_node(nid, NULL, 4031 find_min_pfn_for_node(nid), NULL); 4032 4033 /* Any memory on that node */ 4034 if (pgdat->node_present_pages) 4035 node_set_state(nid, N_HIGH_MEMORY); 4036 check_for_regular_memory(pgdat); 4037 } 4038} 4039 4040static int __init cmdline_parse_core(char *p, unsigned long *core) 4041{ 4042 unsigned long long coremem; 4043 if (!p) 4044 return -EINVAL; 4045 4046 coremem = memparse(p, &p); 4047 *core = coremem >> PAGE_SHIFT; 4048 4049 /* Paranoid check that UL is enough for the coremem value */ 4050 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); 4051 4052 return 0; 4053} 4054 4055/* 4056 * kernelcore=size sets the amount of memory for use for allocations that 4057 * cannot be reclaimed or migrated. 4058 */ 4059static int __init cmdline_parse_kernelcore(char *p) 4060{ 4061 return cmdline_parse_core(p, &required_kernelcore); 4062} 4063 4064/* 4065 * movablecore=size sets the amount of memory for use for allocations that 4066 * can be reclaimed or migrated. 4067 */ 4068static int __init cmdline_parse_movablecore(char *p) 4069{ 4070 return cmdline_parse_core(p, &required_movablecore); 4071} 4072 4073early_param("kernelcore", cmdline_parse_kernelcore); 4074early_param("movablecore", cmdline_parse_movablecore); 4075 4076#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 4077 4078/** 4079 * set_dma_reserve - set the specified number of pages reserved in the first zone 4080 * @new_dma_reserve: The number of pages to mark reserved 4081 * 4082 * The per-cpu batchsize and zone watermarks are determined by present_pages. 4083 * In the DMA zone, a significant percentage may be consumed by kernel image 4084 * and other unfreeable allocations which can skew the watermarks badly. This 4085 * function may optionally be used to account for unfreeable pages in the 4086 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and 4087 * smaller per-cpu batchsize. 4088 */ 4089void __init set_dma_reserve(unsigned long new_dma_reserve) 4090{ 4091 dma_reserve = new_dma_reserve; 4092} 4093 4094#ifndef CONFIG_NEED_MULTIPLE_NODES 4095struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] }; 4096EXPORT_SYMBOL(contig_page_data); 4097#endif 4098 4099void __init free_area_init(unsigned long *zones_size) 4100{ 4101 free_area_init_node(0, zones_size, 4102 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 4103} 4104 4105static int page_alloc_cpu_notify(struct notifier_block *self, 4106 unsigned long action, void *hcpu) 4107{ 4108 int cpu = (unsigned long)hcpu; 4109 4110 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { 4111 drain_pages(cpu); 4112 4113 /* 4114 * Spill the event counters of the dead processor 4115 * into the current processors event counters. 4116 * This artificially elevates the count of the current 4117 * processor. 4118 */ 4119 vm_events_fold_cpu(cpu); 4120 4121 /* 4122 * Zero the differential counters of the dead processor 4123 * so that the vm statistics are consistent. 4124 * 4125 * This is only okay since the processor is dead and cannot 4126 * race with what we are doing. 4127 */ 4128 refresh_cpu_vm_stats(cpu); 4129 } 4130 return NOTIFY_OK; 4131} 4132 4133void __init page_alloc_init(void) 4134{ 4135 hotcpu_notifier(page_alloc_cpu_notify, 0); 4136} 4137 4138/* 4139 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio 4140 * or min_free_kbytes changes. 4141 */ 4142static void calculate_totalreserve_pages(void) 4143{ 4144 struct pglist_data *pgdat; 4145 unsigned long reserve_pages = 0; 4146 enum zone_type i, j; 4147 4148 for_each_online_pgdat(pgdat) { 4149 for (i = 0; i < MAX_NR_ZONES; i++) { 4150 struct zone *zone = pgdat->node_zones + i; 4151 unsigned long max = 0; 4152 4153 /* Find valid and maximum lowmem_reserve in the zone */ 4154 for (j = i; j < MAX_NR_ZONES; j++) { 4155 if (zone->lowmem_reserve[j] > max) 4156 max = zone->lowmem_reserve[j]; 4157 } 4158 4159 /* we treat pages_high as reserved pages. */ 4160 max += zone->pages_high; 4161 4162 if (max > zone->present_pages) 4163 max = zone->present_pages; 4164 reserve_pages += max; 4165 } 4166 } 4167 totalreserve_pages = reserve_pages; 4168} 4169 4170/* 4171 * setup_per_zone_lowmem_reserve - called whenever 4172 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 4173 * has a correct pages reserved value, so an adequate number of 4174 * pages are left in the zone after a successful __alloc_pages(). 4175 */ 4176static void setup_per_zone_lowmem_reserve(void) 4177{ 4178 struct pglist_data *pgdat; 4179 enum zone_type j, idx; 4180 4181 for_each_online_pgdat(pgdat) { 4182 for (j = 0; j < MAX_NR_ZONES; j++) { 4183 struct zone *zone = pgdat->node_zones + j; 4184 unsigned long present_pages = zone->present_pages; 4185 4186 zone->lowmem_reserve[j] = 0; 4187 4188 idx = j; 4189 while (idx) { 4190 struct zone *lower_zone; 4191 4192 idx--; 4193 4194 if (sysctl_lowmem_reserve_ratio[idx] < 1) 4195 sysctl_lowmem_reserve_ratio[idx] = 1; 4196 4197 lower_zone = pgdat->node_zones + idx; 4198 lower_zone->lowmem_reserve[j] = present_pages / 4199 sysctl_lowmem_reserve_ratio[idx]; 4200 present_pages += lower_zone->present_pages; 4201 } 4202 } 4203 } 4204 4205 /* update totalreserve_pages */ 4206 calculate_totalreserve_pages(); 4207} 4208 4209/** 4210 * setup_per_zone_pages_min - called when min_free_kbytes changes. 4211 * 4212 * Ensures that the pages_{min,low,high} values for each zone are set correctly 4213 * with respect to min_free_kbytes. 4214 */ 4215void setup_per_zone_pages_min(void) 4216{ 4217 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 4218 unsigned long lowmem_pages = 0; 4219 struct zone *zone; 4220 unsigned long flags; 4221 4222 /* Calculate total number of !ZONE_HIGHMEM pages */ 4223 for_each_zone(zone) { 4224 if (!is_highmem(zone)) 4225 lowmem_pages += zone->present_pages; 4226 } 4227 4228 for_each_zone(zone) { 4229 u64 tmp; 4230 4231 spin_lock_irqsave(&zone->lock, flags); 4232 tmp = (u64)pages_min * zone->present_pages; 4233 do_div(tmp, lowmem_pages); 4234 if (is_highmem(zone)) { 4235 /* 4236 * __GFP_HIGH and PF_MEMALLOC allocations usually don't 4237 * need highmem pages, so cap pages_min to a small 4238 * value here. 4239 * 4240 * The (pages_high-pages_low) and (pages_low-pages_min) 4241 * deltas controls asynch page reclaim, and so should 4242 * not be capped for highmem. 4243 */ 4244 int min_pages; 4245 4246 min_pages = zone->present_pages / 1024; 4247 if (min_pages < SWAP_CLUSTER_MAX) 4248 min_pages = SWAP_CLUSTER_MAX; 4249 if (min_pages > 128) 4250 min_pages = 128; 4251 zone->pages_min = min_pages; 4252 } else { 4253 /* 4254 * If it's a lowmem zone, reserve a number of pages 4255 * proportionate to the zone's size. 4256 */ 4257 zone->pages_min = tmp; 4258 } 4259 4260 zone->pages_low = zone->pages_min + (tmp >> 2); 4261 zone->pages_high = zone->pages_min + (tmp >> 1); 4262 setup_zone_migrate_reserve(zone); 4263 spin_unlock_irqrestore(&zone->lock, flags); 4264 } 4265 4266 /* update totalreserve_pages */ 4267 calculate_totalreserve_pages(); 4268} 4269 4270/** 4271 * setup_per_zone_inactive_ratio - called when min_free_kbytes changes. 4272 * 4273 * The inactive anon list should be small enough that the VM never has to 4274 * do too much work, but large enough that each inactive page has a chance 4275 * to be referenced again before it is swapped out. 4276 * 4277 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to 4278 * INACTIVE_ANON pages on this zone's LRU, maintained by the 4279 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of 4280 * the anonymous pages are kept on the inactive list. 4281 * 4282 * total target max 4283 * memory ratio inactive anon 4284 * ------------------------------------- 4285 * 10MB 1 5MB 4286 * 100MB 1 50MB 4287 * 1GB 3 250MB 4288 * 10GB 10 0.9GB 4289 * 100GB 31 3GB 4290 * 1TB 101 10GB 4291 * 10TB 320 32GB 4292 */ 4293static void setup_per_zone_inactive_ratio(void) 4294{ 4295 struct zone *zone; 4296 4297 for_each_zone(zone) { 4298 unsigned int gb, ratio; 4299 4300 /* Zone size in gigabytes */ 4301 gb = zone->present_pages >> (30 - PAGE_SHIFT); 4302 ratio = int_sqrt(10 * gb); 4303 if (!ratio) 4304 ratio = 1; 4305 4306 zone->inactive_ratio = ratio; 4307 } 4308} 4309 4310/* 4311 * Initialise min_free_kbytes. 4312 * 4313 * For small machines we want it small (128k min). For large machines 4314 * we want it large (64MB max). But it is not linear, because network 4315 * bandwidth does not increase linearly with machine size. We use 4316 * 4317 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 4318 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 4319 * 4320 * which yields 4321 * 4322 * 16MB: 512k 4323 * 32MB: 724k 4324 * 64MB: 1024k 4325 * 128MB: 1448k 4326 * 256MB: 2048k 4327 * 512MB: 2896k 4328 * 1024MB: 4096k 4329 * 2048MB: 5792k 4330 * 4096MB: 8192k 4331 * 8192MB: 11584k 4332 * 16384MB: 16384k 4333 */ 4334static int __init init_per_zone_pages_min(void) 4335{ 4336 unsigned long lowmem_kbytes; 4337 4338 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 4339 4340 min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 4341 if (min_free_kbytes < 128) 4342 min_free_kbytes = 128; 4343 if (min_free_kbytes > 65536) 4344 min_free_kbytes = 65536; 4345 setup_per_zone_pages_min(); 4346 setup_per_zone_lowmem_reserve(); 4347 setup_per_zone_inactive_ratio(); 4348 return 0; 4349} 4350module_init(init_per_zone_pages_min) 4351 4352/* 4353 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 4354 * that we can call two helper functions whenever min_free_kbytes 4355 * changes. 4356 */ 4357int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 4358 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4359{ 4360 proc_dointvec(table, write, file, buffer, length, ppos); 4361 if (write) 4362 setup_per_zone_pages_min(); 4363 return 0; 4364} 4365 4366#ifdef CONFIG_NUMA 4367int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, 4368 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4369{ 4370 struct zone *zone; 4371 int rc; 4372 4373 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4374 if (rc) 4375 return rc; 4376 4377 for_each_zone(zone) 4378 zone->min_unmapped_pages = (zone->present_pages * 4379 sysctl_min_unmapped_ratio) / 100; 4380 return 0; 4381} 4382 4383int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write, 4384 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4385{ 4386 struct zone *zone; 4387 int rc; 4388 4389 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4390 if (rc) 4391 return rc; 4392 4393 for_each_zone(zone) 4394 zone->min_slab_pages = (zone->present_pages * 4395 sysctl_min_slab_ratio) / 100; 4396 return 0; 4397} 4398#endif 4399 4400/* 4401 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 4402 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 4403 * whenever sysctl_lowmem_reserve_ratio changes. 4404 * 4405 * The reserve ratio obviously has absolutely no relation with the 4406 * pages_min watermarks. The lowmem reserve ratio can only make sense 4407 * if in function of the boot time zone sizes. 4408 */ 4409int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, 4410 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4411{ 4412 proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4413 setup_per_zone_lowmem_reserve(); 4414 return 0; 4415} 4416 4417/* 4418 * percpu_pagelist_fraction - changes the pcp->high for each zone on each 4419 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist 4420 * can have before it gets flushed back to buddy allocator. 4421 */ 4422 4423int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, 4424 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4425{ 4426 struct zone *zone; 4427 unsigned int cpu; 4428 int ret; 4429 4430 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4431 if (!write || (ret == -EINVAL)) 4432 return ret; 4433 for_each_zone(zone) { 4434 for_each_online_cpu(cpu) { 4435 unsigned long high; 4436 high = zone->present_pages / percpu_pagelist_fraction; 4437 setup_pagelist_highmark(zone_pcp(zone, cpu), high); 4438 } 4439 } 4440 return 0; 4441} 4442 4443int hashdist = HASHDIST_DEFAULT; 4444 4445#ifdef CONFIG_NUMA 4446static int __init set_hashdist(char *str) 4447{ 4448 if (!str) 4449 return 0; 4450 hashdist = simple_strtoul(str, &str, 0); 4451 return 1; 4452} 4453__setup("hashdist=", set_hashdist); 4454#endif 4455 4456/* 4457 * allocate a large system hash table from bootmem 4458 * - it is assumed that the hash table must contain an exact power-of-2 4459 * quantity of entries 4460 * - limit is the number of hash buckets, not the total allocation size 4461 */ 4462void *__init alloc_large_system_hash(const char *tablename, 4463 unsigned long bucketsize, 4464 unsigned long numentries, 4465 int scale, 4466 int flags, 4467 unsigned int *_hash_shift, 4468 unsigned int *_hash_mask, 4469 unsigned long limit) 4470{ 4471 unsigned long long max = limit; 4472 unsigned long log2qty, size; 4473 void *table = NULL; 4474 4475 /* allow the kernel cmdline to have a say */ 4476 if (!numentries) { 4477 /* round applicable memory size up to nearest megabyte */ 4478 numentries = nr_kernel_pages; 4479 numentries += (1UL << (20 - PAGE_SHIFT)) - 1; 4480 numentries >>= 20 - PAGE_SHIFT; 4481 numentries <<= 20 - PAGE_SHIFT; 4482 4483 /* limit to 1 bucket per 2^scale bytes of low memory */ 4484 if (scale > PAGE_SHIFT) 4485 numentries >>= (scale - PAGE_SHIFT); 4486 else 4487 numentries <<= (PAGE_SHIFT - scale); 4488 4489 /* Make sure we've got at least a 0-order allocation.. */ 4490 if (unlikely((numentries * bucketsize) < PAGE_SIZE)) 4491 numentries = PAGE_SIZE / bucketsize; 4492 } 4493 numentries = roundup_pow_of_two(numentries); 4494 4495 /* limit allocation size to 1/16 total memory by default */ 4496 if (max == 0) { 4497 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 4498 do_div(max, bucketsize); 4499 } 4500 4501 if (numentries > max) 4502 numentries = max; 4503 4504 log2qty = ilog2(numentries); 4505 4506 do { 4507 size = bucketsize << log2qty; 4508 if (flags & HASH_EARLY) 4509 table = alloc_bootmem_nopanic(size); 4510 else if (hashdist) 4511 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 4512 else { 4513 unsigned long order = get_order(size); 4514 4515 if (order < MAX_ORDER) 4516 table = (void *)__get_free_pages(GFP_ATOMIC, 4517 order); 4518 /* 4519 * If bucketsize is not a power-of-two, we may free 4520 * some pages at the end of hash table. 4521 */ 4522 if (table) { 4523 unsigned long alloc_end = (unsigned long)table + 4524 (PAGE_SIZE << order); 4525 unsigned long used = (unsigned long)table + 4526 PAGE_ALIGN(size); 4527 split_page(virt_to_page(table), order); 4528 while (used < alloc_end) { 4529 free_page(used); 4530 used += PAGE_SIZE; 4531 } 4532 } 4533 } 4534 } while (!table && size > PAGE_SIZE && --log2qty); 4535 4536 if (!table) 4537 panic("Failed to allocate %s hash table\n", tablename); 4538 4539 printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n", 4540 tablename, 4541 (1U << log2qty), 4542 ilog2(size) - PAGE_SHIFT, 4543 size); 4544 4545 if (_hash_shift) 4546 *_hash_shift = log2qty; 4547 if (_hash_mask) 4548 *_hash_mask = (1 << log2qty) - 1; 4549 4550 /* 4551 * If hashdist is set, the table allocation is done with __vmalloc() 4552 * which invokes the kmemleak_alloc() callback. This function may also 4553 * be called before the slab and kmemleak are initialised when 4554 * kmemleak simply buffers the request to be executed later 4555 * (GFP_ATOMIC flag ignored in this case). 4556 */ 4557 if (!hashdist) 4558 kmemleak_alloc(table, size, 1, GFP_ATOMIC); 4559 4560 return table; 4561} 4562 4563/* Return a pointer to the bitmap storing bits affecting a block of pages */ 4564static inline unsigned long *get_pageblock_bitmap(struct zone *zone, 4565 unsigned long pfn) 4566{ 4567#ifdef CONFIG_SPARSEMEM 4568 return __pfn_to_section(pfn)->pageblock_flags; 4569#else 4570 return zone->pageblock_flags; 4571#endif /* CONFIG_SPARSEMEM */ 4572} 4573 4574static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) 4575{ 4576#ifdef CONFIG_SPARSEMEM 4577 pfn &= (PAGES_PER_SECTION-1); 4578 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 4579#else 4580 pfn = pfn - zone->zone_start_pfn; 4581 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 4582#endif /* CONFIG_SPARSEMEM */ 4583} 4584 4585/** 4586 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages 4587 * @page: The page within the block of interest 4588 * @start_bitidx: The first bit of interest to retrieve 4589 * @end_bitidx: The last bit of interest 4590 * returns pageblock_bits flags 4591 */ 4592unsigned long get_pageblock_flags_group(struct page *page, 4593 int start_bitidx, int end_bitidx) 4594{ 4595 struct zone *zone; 4596 unsigned long *bitmap; 4597 unsigned long pfn, bitidx; 4598 unsigned long flags = 0; 4599 unsigned long value = 1; 4600 4601 zone = page_zone(page); 4602 pfn = page_to_pfn(page); 4603 bitmap = get_pageblock_bitmap(zone, pfn); 4604 bitidx = pfn_to_bitidx(zone, pfn); 4605 4606 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 4607 if (test_bit(bitidx + start_bitidx, bitmap)) 4608 flags |= value; 4609 4610 return flags; 4611} 4612 4613/** 4614 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages 4615 * @page: The page within the block of interest 4616 * @start_bitidx: The first bit of interest 4617 * @end_bitidx: The last bit of interest 4618 * @flags: The flags to set 4619 */ 4620void set_pageblock_flags_group(struct page *page, unsigned long flags, 4621 int start_bitidx, int end_bitidx) 4622{ 4623 struct zone *zone; 4624 unsigned long *bitmap; 4625 unsigned long pfn, bitidx; 4626 unsigned long value = 1; 4627 4628 zone = page_zone(page); 4629 pfn = page_to_pfn(page); 4630 bitmap = get_pageblock_bitmap(zone, pfn); 4631 bitidx = pfn_to_bitidx(zone, pfn); 4632 VM_BUG_ON(pfn < zone->zone_start_pfn); 4633 VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages); 4634 4635 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 4636 if (flags & value) 4637 __set_bit(bitidx + start_bitidx, bitmap); 4638 else 4639 __clear_bit(bitidx + start_bitidx, bitmap); 4640} 4641 4642/* 4643 * This is designed as sub function...plz see page_isolation.c also. 4644 * set/clear page block's type to be ISOLATE. 4645 * page allocater never alloc memory from ISOLATE block. 4646 */ 4647 4648int set_migratetype_isolate(struct page *page) 4649{ 4650 struct zone *zone; 4651 unsigned long flags; 4652 int ret = -EBUSY; 4653 4654 zone = page_zone(page); 4655 spin_lock_irqsave(&zone->lock, flags); 4656 /* 4657 * In future, more migrate types will be able to be isolation target. 4658 */ 4659 if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE) 4660 goto out; 4661 set_pageblock_migratetype(page, MIGRATE_ISOLATE); 4662 move_freepages_block(zone, page, MIGRATE_ISOLATE); 4663 ret = 0; 4664out: 4665 spin_unlock_irqrestore(&zone->lock, flags); 4666 if (!ret) 4667 drain_all_pages(); 4668 return ret; 4669} 4670 4671void unset_migratetype_isolate(struct page *page) 4672{ 4673 struct zone *zone; 4674 unsigned long flags; 4675 zone = page_zone(page); 4676 spin_lock_irqsave(&zone->lock, flags); 4677 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE) 4678 goto out; 4679 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 4680 move_freepages_block(zone, page, MIGRATE_MOVABLE); 4681out: 4682 spin_unlock_irqrestore(&zone->lock, flags); 4683} 4684 4685#ifdef CONFIG_MEMORY_HOTREMOVE 4686/* 4687 * All pages in the range must be isolated before calling this. 4688 */ 4689void 4690__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) 4691{ 4692 struct page *page; 4693 struct zone *zone; 4694 int order, i; 4695 unsigned long pfn; 4696 unsigned long flags; 4697 /* find the first valid pfn */ 4698 for (pfn = start_pfn; pfn < end_pfn; pfn++) 4699 if (pfn_valid(pfn)) 4700 break; 4701 if (pfn == end_pfn) 4702 return; 4703 zone = page_zone(pfn_to_page(pfn)); 4704 spin_lock_irqsave(&zone->lock, flags); 4705 pfn = start_pfn; 4706 while (pfn < end_pfn) { 4707 if (!pfn_valid(pfn)) { 4708 pfn++; 4709 continue; 4710 } 4711 page = pfn_to_page(pfn); 4712 BUG_ON(page_count(page)); 4713 BUG_ON(!PageBuddy(page)); 4714 order = page_order(page); 4715#ifdef CONFIG_DEBUG_VM 4716 printk(KERN_INFO "remove from free list %lx %d %lx\n", 4717 pfn, 1 << order, end_pfn); 4718#endif 4719 list_del(&page->lru); 4720 rmv_page_order(page); 4721 zone->free_area[order].nr_free--; 4722 __mod_zone_page_state(zone, NR_FREE_PAGES, 4723 - (1UL << order)); 4724 for (i = 0; i < (1 << order); i++) 4725 SetPageReserved((page+i)); 4726 pfn += (1 << order); 4727 } 4728 spin_unlock_irqrestore(&zone->lock, flags); 4729} 4730#endif 4731