page_alloc.c revision d936cf9b39b06c8d2e0d7fb5e7b4f176e18dec69
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 50#include <asm/tlbflush.h> 51#include <asm/div64.h> 52#include "internal.h" 53 54/* 55 * Array of node states. 56 */ 57nodemask_t node_states[NR_NODE_STATES] __read_mostly = { 58 [N_POSSIBLE] = NODE_MASK_ALL, 59 [N_ONLINE] = { { [0] = 1UL } }, 60#ifndef CONFIG_NUMA 61 [N_NORMAL_MEMORY] = { { [0] = 1UL } }, 62#ifdef CONFIG_HIGHMEM 63 [N_HIGH_MEMORY] = { { [0] = 1UL } }, 64#endif 65 [N_CPU] = { { [0] = 1UL } }, 66#endif /* NUMA */ 67}; 68EXPORT_SYMBOL(node_states); 69 70unsigned long totalram_pages __read_mostly; 71unsigned long totalreserve_pages __read_mostly; 72unsigned long highest_memmap_pfn __read_mostly; 73int percpu_pagelist_fraction; 74 75#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 76int pageblock_order __read_mostly; 77#endif 78 79static void __free_pages_ok(struct page *page, unsigned int order); 80 81/* 82 * results with 256, 32 in the lowmem_reserve sysctl: 83 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) 84 * 1G machine -> (16M dma, 784M normal, 224M high) 85 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA 86 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL 87 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA 88 * 89 * TBD: should special case ZONE_DMA32 machines here - in those we normally 90 * don't need any ZONE_NORMAL reservation 91 */ 92int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 93#ifdef CONFIG_ZONE_DMA 94 256, 95#endif 96#ifdef CONFIG_ZONE_DMA32 97 256, 98#endif 99#ifdef CONFIG_HIGHMEM 100 32, 101#endif 102 32, 103}; 104 105EXPORT_SYMBOL(totalram_pages); 106 107static char * const zone_names[MAX_NR_ZONES] = { 108#ifdef CONFIG_ZONE_DMA 109 "DMA", 110#endif 111#ifdef CONFIG_ZONE_DMA32 112 "DMA32", 113#endif 114 "Normal", 115#ifdef CONFIG_HIGHMEM 116 "HighMem", 117#endif 118 "Movable", 119}; 120 121int min_free_kbytes = 1024; 122 123unsigned long __meminitdata nr_kernel_pages; 124unsigned long __meminitdata nr_all_pages; 125static unsigned long __meminitdata dma_reserve; 126 127#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 128 /* 129 * MAX_ACTIVE_REGIONS determines the maximum number of distinct 130 * ranges of memory (RAM) that may be registered with add_active_range(). 131 * Ranges passed to add_active_range() will be merged if possible 132 * so the number of times add_active_range() can be called is 133 * related to the number of nodes and the number of holes 134 */ 135 #ifdef CONFIG_MAX_ACTIVE_REGIONS 136 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */ 137 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS 138 #else 139 #if MAX_NUMNODES >= 32 140 /* If there can be many nodes, allow up to 50 holes per node */ 141 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50) 142 #else 143 /* By default, allow up to 256 distinct regions */ 144 #define MAX_ACTIVE_REGIONS 256 145 #endif 146 #endif 147 148 static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS]; 149 static int __meminitdata nr_nodemap_entries; 150 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; 151 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; 152#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE 153 static unsigned long __meminitdata node_boundary_start_pfn[MAX_NUMNODES]; 154 static unsigned long __meminitdata node_boundary_end_pfn[MAX_NUMNODES]; 155#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */ 156 static unsigned long __initdata required_kernelcore; 157 static unsigned long __initdata required_movablecore; 158 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES]; 159 160 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ 161 int movable_zone; 162 EXPORT_SYMBOL(movable_zone); 163#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 164 165#if MAX_NUMNODES > 1 166int nr_node_ids __read_mostly = MAX_NUMNODES; 167EXPORT_SYMBOL(nr_node_ids); 168#endif 169 170int page_group_by_mobility_disabled __read_mostly; 171 172static void set_pageblock_migratetype(struct page *page, int migratetype) 173{ 174 set_pageblock_flags_group(page, (unsigned long)migratetype, 175 PB_migrate, PB_migrate_end); 176} 177 178#ifdef CONFIG_DEBUG_VM 179static int page_outside_zone_boundaries(struct zone *zone, struct page *page) 180{ 181 int ret = 0; 182 unsigned seq; 183 unsigned long pfn = page_to_pfn(page); 184 185 do { 186 seq = zone_span_seqbegin(zone); 187 if (pfn >= zone->zone_start_pfn + zone->spanned_pages) 188 ret = 1; 189 else if (pfn < zone->zone_start_pfn) 190 ret = 1; 191 } while (zone_span_seqretry(zone, seq)); 192 193 return ret; 194} 195 196static int page_is_consistent(struct zone *zone, struct page *page) 197{ 198 if (!pfn_valid_within(page_to_pfn(page))) 199 return 0; 200 if (zone != page_zone(page)) 201 return 0; 202 203 return 1; 204} 205/* 206 * Temporary debugging check for pages not lying within a given zone. 207 */ 208static int bad_range(struct zone *zone, struct page *page) 209{ 210 if (page_outside_zone_boundaries(zone, page)) 211 return 1; 212 if (!page_is_consistent(zone, page)) 213 return 1; 214 215 return 0; 216} 217#else 218static inline int bad_range(struct zone *zone, struct page *page) 219{ 220 return 0; 221} 222#endif 223 224static void bad_page(struct page *page) 225{ 226 static unsigned long resume; 227 static unsigned long nr_shown; 228 static unsigned long nr_unshown; 229 230 /* 231 * Allow a burst of 60 reports, then keep quiet for that minute; 232 * or allow a steady drip of one report per second. 233 */ 234 if (nr_shown == 60) { 235 if (time_before(jiffies, resume)) { 236 nr_unshown++; 237 goto out; 238 } 239 if (nr_unshown) { 240 printk(KERN_EMERG 241 "Bad page state: %lu messages suppressed\n", 242 nr_unshown); 243 nr_unshown = 0; 244 } 245 nr_shown = 0; 246 } 247 if (nr_shown++ == 0) 248 resume = jiffies + 60 * HZ; 249 250 printk(KERN_EMERG "Bad page state in process %s pfn:%05lx\n", 251 current->comm, page_to_pfn(page)); 252 printk(KERN_EMERG 253 "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n", 254 page, (void *)page->flags, page_count(page), 255 page_mapcount(page), page->mapping, page->index); 256 printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n"); 257 258 dump_stack(); 259out: 260 /* Leave bad fields for debug, except PageBuddy could make trouble */ 261 __ClearPageBuddy(page); 262 add_taint(TAINT_BAD_PAGE); 263} 264 265/* 266 * Higher-order pages are called "compound pages". They are structured thusly: 267 * 268 * The first PAGE_SIZE page is called the "head page". 269 * 270 * The remaining PAGE_SIZE pages are called "tail pages". 271 * 272 * All pages have PG_compound set. All pages have their ->private pointing at 273 * the head page (even the head page has this). 274 * 275 * The first tail page's ->lru.next holds the address of the compound page's 276 * put_page() function. Its ->lru.prev holds the order of allocation. 277 * This usage means that zero-order pages may not be compound. 278 */ 279 280static void free_compound_page(struct page *page) 281{ 282 __free_pages_ok(page, compound_order(page)); 283} 284 285void prep_compound_page(struct page *page, unsigned long order) 286{ 287 int i; 288 int nr_pages = 1 << order; 289 290 set_compound_page_dtor(page, free_compound_page); 291 set_compound_order(page, order); 292 __SetPageHead(page); 293 for (i = 1; i < nr_pages; i++) { 294 struct page *p = page + i; 295 296 __SetPageTail(p); 297 p->first_page = page; 298 } 299} 300 301#ifdef CONFIG_HUGETLBFS 302void prep_compound_gigantic_page(struct page *page, unsigned long order) 303{ 304 int i; 305 int nr_pages = 1 << order; 306 struct page *p = page + 1; 307 308 set_compound_page_dtor(page, free_compound_page); 309 set_compound_order(page, order); 310 __SetPageHead(page); 311 for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) { 312 __SetPageTail(p); 313 p->first_page = page; 314 } 315} 316#endif 317 318static int destroy_compound_page(struct page *page, unsigned long order) 319{ 320 int i; 321 int nr_pages = 1 << order; 322 int bad = 0; 323 324 if (unlikely(compound_order(page) != order) || 325 unlikely(!PageHead(page))) { 326 bad_page(page); 327 bad++; 328 } 329 330 __ClearPageHead(page); 331 332 for (i = 1; i < nr_pages; i++) { 333 struct page *p = page + i; 334 335 if (unlikely(!PageTail(p) | (p->first_page != page))) { 336 bad_page(page); 337 bad++; 338 } 339 __ClearPageTail(p); 340 } 341 342 return bad; 343} 344 345static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) 346{ 347 int i; 348 349 /* 350 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO 351 * and __GFP_HIGHMEM from hard or soft interrupt context. 352 */ 353 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); 354 for (i = 0; i < (1 << order); i++) 355 clear_highpage(page + i); 356} 357 358static inline void set_page_order(struct page *page, int order) 359{ 360 set_page_private(page, order); 361 __SetPageBuddy(page); 362} 363 364static inline void rmv_page_order(struct page *page) 365{ 366 __ClearPageBuddy(page); 367 set_page_private(page, 0); 368} 369 370/* 371 * Locate the struct page for both the matching buddy in our 372 * pair (buddy1) and the combined O(n+1) page they form (page). 373 * 374 * 1) Any buddy B1 will have an order O twin B2 which satisfies 375 * the following equation: 376 * B2 = B1 ^ (1 << O) 377 * For example, if the starting buddy (buddy2) is #8 its order 378 * 1 buddy is #10: 379 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 380 * 381 * 2) Any buddy B will have an order O+1 parent P which 382 * satisfies the following equation: 383 * P = B & ~(1 << O) 384 * 385 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 386 */ 387static inline struct page * 388__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order) 389{ 390 unsigned long buddy_idx = page_idx ^ (1 << order); 391 392 return page + (buddy_idx - page_idx); 393} 394 395static inline unsigned long 396__find_combined_index(unsigned long page_idx, unsigned int order) 397{ 398 return (page_idx & ~(1 << order)); 399} 400 401/* 402 * This function checks whether a page is free && is the buddy 403 * we can do coalesce a page and its buddy if 404 * (a) the buddy is not in a hole && 405 * (b) the buddy is in the buddy system && 406 * (c) a page and its buddy have the same order && 407 * (d) a page and its buddy are in the same zone. 408 * 409 * For recording whether a page is in the buddy system, we use PG_buddy. 410 * Setting, clearing, and testing PG_buddy is serialized by zone->lock. 411 * 412 * For recording page's order, we use page_private(page). 413 */ 414static inline int page_is_buddy(struct page *page, struct page *buddy, 415 int order) 416{ 417 if (!pfn_valid_within(page_to_pfn(buddy))) 418 return 0; 419 420 if (page_zone_id(page) != page_zone_id(buddy)) 421 return 0; 422 423 if (PageBuddy(buddy) && page_order(buddy) == order) { 424 BUG_ON(page_count(buddy) != 0); 425 return 1; 426 } 427 return 0; 428} 429 430/* 431 * Freeing function for a buddy system allocator. 432 * 433 * The concept of a buddy system is to maintain direct-mapped table 434 * (containing bit values) for memory blocks of various "orders". 435 * The bottom level table contains the map for the smallest allocatable 436 * units of memory (here, pages), and each level above it describes 437 * pairs of units from the levels below, hence, "buddies". 438 * At a high level, all that happens here is marking the table entry 439 * at the bottom level available, and propagating the changes upward 440 * as necessary, plus some accounting needed to play nicely with other 441 * parts of the VM system. 442 * At each level, we keep a list of pages, which are heads of continuous 443 * free pages of length of (1 << order) and marked with PG_buddy. Page's 444 * order is recorded in page_private(page) field. 445 * So when we are allocating or freeing one, we can derive the state of the 446 * other. That is, if we allocate a small block, and both were 447 * free, the remainder of the region must be split into blocks. 448 * If a block is freed, and its buddy is also free, then this 449 * triggers coalescing into a block of larger size. 450 * 451 * -- wli 452 */ 453 454static inline void __free_one_page(struct page *page, 455 struct zone *zone, unsigned int order) 456{ 457 unsigned long page_idx; 458 int order_size = 1 << order; 459 int migratetype = get_pageblock_migratetype(page); 460 461 if (unlikely(PageCompound(page))) 462 if (unlikely(destroy_compound_page(page, order))) 463 return; 464 465 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); 466 467 VM_BUG_ON(page_idx & (order_size - 1)); 468 VM_BUG_ON(bad_range(zone, page)); 469 470 __mod_zone_page_state(zone, NR_FREE_PAGES, order_size); 471 while (order < MAX_ORDER-1) { 472 unsigned long combined_idx; 473 struct page *buddy; 474 475 buddy = __page_find_buddy(page, page_idx, order); 476 if (!page_is_buddy(page, buddy, order)) 477 break; 478 479 /* Our buddy is free, merge with it and move up one order. */ 480 list_del(&buddy->lru); 481 zone->free_area[order].nr_free--; 482 rmv_page_order(buddy); 483 combined_idx = __find_combined_index(page_idx, order); 484 page = page + (combined_idx - page_idx); 485 page_idx = combined_idx; 486 order++; 487 } 488 set_page_order(page, order); 489 list_add(&page->lru, 490 &zone->free_area[order].free_list[migratetype]); 491 zone->free_area[order].nr_free++; 492} 493 494static inline int free_pages_check(struct page *page) 495{ 496 free_page_mlock(page); 497 if (unlikely(page_mapcount(page) | 498 (page->mapping != NULL) | 499 (page_count(page) != 0) | 500 (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) { 501 bad_page(page); 502 return 1; 503 } 504 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP) 505 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; 506 return 0; 507} 508 509/* 510 * Frees a list of pages. 511 * Assumes all pages on list are in same zone, and of same order. 512 * count is the number of pages to free. 513 * 514 * If the zone was previously in an "all pages pinned" state then look to 515 * see if this freeing clears that state. 516 * 517 * And clear the zone's pages_scanned counter, to hold off the "all pages are 518 * pinned" detection logic. 519 */ 520static void free_pages_bulk(struct zone *zone, int count, 521 struct list_head *list, int order) 522{ 523 spin_lock(&zone->lock); 524 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); 525 zone->pages_scanned = 0; 526 while (count--) { 527 struct page *page; 528 529 VM_BUG_ON(list_empty(list)); 530 page = list_entry(list->prev, struct page, lru); 531 /* have to delete it as __free_one_page list manipulates */ 532 list_del(&page->lru); 533 __free_one_page(page, zone, order); 534 } 535 spin_unlock(&zone->lock); 536} 537 538static void free_one_page(struct zone *zone, struct page *page, int order) 539{ 540 spin_lock(&zone->lock); 541 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); 542 zone->pages_scanned = 0; 543 __free_one_page(page, zone, order); 544 spin_unlock(&zone->lock); 545} 546 547static void __free_pages_ok(struct page *page, unsigned int order) 548{ 549 unsigned long flags; 550 int i; 551 int bad = 0; 552 553 for (i = 0 ; i < (1 << order) ; ++i) 554 bad += free_pages_check(page + i); 555 if (bad) 556 return; 557 558 if (!PageHighMem(page)) { 559 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order); 560 debug_check_no_obj_freed(page_address(page), 561 PAGE_SIZE << order); 562 } 563 arch_free_page(page, order); 564 kernel_map_pages(page, 1 << order, 0); 565 566 local_irq_save(flags); 567 __count_vm_events(PGFREE, 1 << order); 568 free_one_page(page_zone(page), page, order); 569 local_irq_restore(flags); 570} 571 572/* 573 * permit the bootmem allocator to evade page validation on high-order frees 574 */ 575void __meminit __free_pages_bootmem(struct page *page, unsigned int order) 576{ 577 if (order == 0) { 578 __ClearPageReserved(page); 579 set_page_count(page, 0); 580 set_page_refcounted(page); 581 __free_page(page); 582 } else { 583 int loop; 584 585 prefetchw(page); 586 for (loop = 0; loop < BITS_PER_LONG; loop++) { 587 struct page *p = &page[loop]; 588 589 if (loop + 1 < BITS_PER_LONG) 590 prefetchw(p + 1); 591 __ClearPageReserved(p); 592 set_page_count(p, 0); 593 } 594 595 set_page_refcounted(page); 596 __free_pages(page, order); 597 } 598} 599 600 601/* 602 * The order of subdivision here is critical for the IO subsystem. 603 * Please do not alter this order without good reasons and regression 604 * testing. Specifically, as large blocks of memory are subdivided, 605 * the order in which smaller blocks are delivered depends on the order 606 * they're subdivided in this function. This is the primary factor 607 * influencing the order in which pages are delivered to the IO 608 * subsystem according to empirical testing, and this is also justified 609 * by considering the behavior of a buddy system containing a single 610 * large block of memory acted on by a series of small allocations. 611 * This behavior is a critical factor in sglist merging's success. 612 * 613 * -- wli 614 */ 615static inline void expand(struct zone *zone, struct page *page, 616 int low, int high, struct free_area *area, 617 int migratetype) 618{ 619 unsigned long size = 1 << high; 620 621 while (high > low) { 622 area--; 623 high--; 624 size >>= 1; 625 VM_BUG_ON(bad_range(zone, &page[size])); 626 list_add(&page[size].lru, &area->free_list[migratetype]); 627 area->nr_free++; 628 set_page_order(&page[size], high); 629 } 630} 631 632/* 633 * This page is about to be returned from the page allocator 634 */ 635static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) 636{ 637 if (unlikely(page_mapcount(page) | 638 (page->mapping != NULL) | 639 (page_count(page) != 0) | 640 (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) { 641 bad_page(page); 642 return 1; 643 } 644 645 set_page_private(page, 0); 646 set_page_refcounted(page); 647 648 arch_alloc_page(page, order); 649 kernel_map_pages(page, 1 << order, 1); 650 651 if (gfp_flags & __GFP_ZERO) 652 prep_zero_page(page, order, gfp_flags); 653 654 if (order && (gfp_flags & __GFP_COMP)) 655 prep_compound_page(page, order); 656 657 return 0; 658} 659 660/* 661 * Go through the free lists for the given migratetype and remove 662 * the smallest available page from the freelists 663 */ 664static struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, 665 int migratetype) 666{ 667 unsigned int current_order; 668 struct free_area * area; 669 struct page *page; 670 671 /* Find a page of the appropriate size in the preferred list */ 672 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 673 area = &(zone->free_area[current_order]); 674 if (list_empty(&area->free_list[migratetype])) 675 continue; 676 677 page = list_entry(area->free_list[migratetype].next, 678 struct page, lru); 679 list_del(&page->lru); 680 rmv_page_order(page); 681 area->nr_free--; 682 __mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order)); 683 expand(zone, page, order, current_order, area, migratetype); 684 return page; 685 } 686 687 return NULL; 688} 689 690 691/* 692 * This array describes the order lists are fallen back to when 693 * the free lists for the desirable migrate type are depleted 694 */ 695static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = { 696 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 697 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 698 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, 699 [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */ 700}; 701 702/* 703 * Move the free pages in a range to the free lists of the requested type. 704 * Note that start_page and end_pages are not aligned on a pageblock 705 * boundary. If alignment is required, use move_freepages_block() 706 */ 707static int move_freepages(struct zone *zone, 708 struct page *start_page, struct page *end_page, 709 int migratetype) 710{ 711 struct page *page; 712 unsigned long order; 713 int pages_moved = 0; 714 715#ifndef CONFIG_HOLES_IN_ZONE 716 /* 717 * page_zone is not safe to call in this context when 718 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant 719 * anyway as we check zone boundaries in move_freepages_block(). 720 * Remove at a later date when no bug reports exist related to 721 * grouping pages by mobility 722 */ 723 BUG_ON(page_zone(start_page) != page_zone(end_page)); 724#endif 725 726 for (page = start_page; page <= end_page;) { 727 /* Make sure we are not inadvertently changing nodes */ 728 VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone)); 729 730 if (!pfn_valid_within(page_to_pfn(page))) { 731 page++; 732 continue; 733 } 734 735 if (!PageBuddy(page)) { 736 page++; 737 continue; 738 } 739 740 order = page_order(page); 741 list_del(&page->lru); 742 list_add(&page->lru, 743 &zone->free_area[order].free_list[migratetype]); 744 page += 1 << order; 745 pages_moved += 1 << order; 746 } 747 748 return pages_moved; 749} 750 751static int move_freepages_block(struct zone *zone, struct page *page, 752 int migratetype) 753{ 754 unsigned long start_pfn, end_pfn; 755 struct page *start_page, *end_page; 756 757 start_pfn = page_to_pfn(page); 758 start_pfn = start_pfn & ~(pageblock_nr_pages-1); 759 start_page = pfn_to_page(start_pfn); 760 end_page = start_page + pageblock_nr_pages - 1; 761 end_pfn = start_pfn + pageblock_nr_pages - 1; 762 763 /* Do not cross zone boundaries */ 764 if (start_pfn < zone->zone_start_pfn) 765 start_page = page; 766 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages) 767 return 0; 768 769 return move_freepages(zone, start_page, end_page, migratetype); 770} 771 772/* Remove an element from the buddy allocator from the fallback list */ 773static struct page *__rmqueue_fallback(struct zone *zone, int order, 774 int start_migratetype) 775{ 776 struct free_area * area; 777 int current_order; 778 struct page *page; 779 int migratetype, i; 780 781 /* Find the largest possible block of pages in the other list */ 782 for (current_order = MAX_ORDER-1; current_order >= order; 783 --current_order) { 784 for (i = 0; i < MIGRATE_TYPES - 1; i++) { 785 migratetype = fallbacks[start_migratetype][i]; 786 787 /* MIGRATE_RESERVE handled later if necessary */ 788 if (migratetype == MIGRATE_RESERVE) 789 continue; 790 791 area = &(zone->free_area[current_order]); 792 if (list_empty(&area->free_list[migratetype])) 793 continue; 794 795 page = list_entry(area->free_list[migratetype].next, 796 struct page, lru); 797 area->nr_free--; 798 799 /* 800 * If breaking a large block of pages, move all free 801 * pages to the preferred allocation list. If falling 802 * back for a reclaimable kernel allocation, be more 803 * agressive about taking ownership of free pages 804 */ 805 if (unlikely(current_order >= (pageblock_order >> 1)) || 806 start_migratetype == MIGRATE_RECLAIMABLE) { 807 unsigned long pages; 808 pages = move_freepages_block(zone, page, 809 start_migratetype); 810 811 /* Claim the whole block if over half of it is free */ 812 if (pages >= (1 << (pageblock_order-1))) 813 set_pageblock_migratetype(page, 814 start_migratetype); 815 816 migratetype = start_migratetype; 817 } 818 819 /* Remove the page from the freelists */ 820 list_del(&page->lru); 821 rmv_page_order(page); 822 __mod_zone_page_state(zone, NR_FREE_PAGES, 823 -(1UL << order)); 824 825 if (current_order == pageblock_order) 826 set_pageblock_migratetype(page, 827 start_migratetype); 828 829 expand(zone, page, order, current_order, area, migratetype); 830 return page; 831 } 832 } 833 834 /* Use MIGRATE_RESERVE rather than fail an allocation */ 835 return __rmqueue_smallest(zone, order, MIGRATE_RESERVE); 836} 837 838/* 839 * Do the hard work of removing an element from the buddy allocator. 840 * Call me with the zone->lock already held. 841 */ 842static struct page *__rmqueue(struct zone *zone, unsigned int order, 843 int migratetype) 844{ 845 struct page *page; 846 847 page = __rmqueue_smallest(zone, order, migratetype); 848 849 if (unlikely(!page)) 850 page = __rmqueue_fallback(zone, order, migratetype); 851 852 return page; 853} 854 855/* 856 * Obtain a specified number of elements from the buddy allocator, all under 857 * a single hold of the lock, for efficiency. Add them to the supplied list. 858 * Returns the number of new pages which were placed at *list. 859 */ 860static int rmqueue_bulk(struct zone *zone, unsigned int order, 861 unsigned long count, struct list_head *list, 862 int migratetype) 863{ 864 int i; 865 866 spin_lock(&zone->lock); 867 for (i = 0; i < count; ++i) { 868 struct page *page = __rmqueue(zone, order, migratetype); 869 if (unlikely(page == NULL)) 870 break; 871 872 /* 873 * Split buddy pages returned by expand() are received here 874 * in physical page order. The page is added to the callers and 875 * list and the list head then moves forward. From the callers 876 * perspective, the linked list is ordered by page number in 877 * some conditions. This is useful for IO devices that can 878 * merge IO requests if the physical pages are ordered 879 * properly. 880 */ 881 list_add(&page->lru, list); 882 set_page_private(page, migratetype); 883 list = &page->lru; 884 } 885 spin_unlock(&zone->lock); 886 return i; 887} 888 889#ifdef CONFIG_NUMA 890/* 891 * Called from the vmstat counter updater to drain pagesets of this 892 * currently executing processor on remote nodes after they have 893 * expired. 894 * 895 * Note that this function must be called with the thread pinned to 896 * a single processor. 897 */ 898void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) 899{ 900 unsigned long flags; 901 int to_drain; 902 903 local_irq_save(flags); 904 if (pcp->count >= pcp->batch) 905 to_drain = pcp->batch; 906 else 907 to_drain = pcp->count; 908 free_pages_bulk(zone, to_drain, &pcp->list, 0); 909 pcp->count -= to_drain; 910 local_irq_restore(flags); 911} 912#endif 913 914/* 915 * Drain pages of the indicated processor. 916 * 917 * The processor must either be the current processor and the 918 * thread pinned to the current processor or a processor that 919 * is not online. 920 */ 921static void drain_pages(unsigned int cpu) 922{ 923 unsigned long flags; 924 struct zone *zone; 925 926 for_each_zone(zone) { 927 struct per_cpu_pageset *pset; 928 struct per_cpu_pages *pcp; 929 930 if (!populated_zone(zone)) 931 continue; 932 933 pset = zone_pcp(zone, cpu); 934 935 pcp = &pset->pcp; 936 local_irq_save(flags); 937 free_pages_bulk(zone, pcp->count, &pcp->list, 0); 938 pcp->count = 0; 939 local_irq_restore(flags); 940 } 941} 942 943/* 944 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 945 */ 946void drain_local_pages(void *arg) 947{ 948 drain_pages(smp_processor_id()); 949} 950 951/* 952 * Spill all the per-cpu pages from all CPUs back into the buddy allocator 953 */ 954void drain_all_pages(void) 955{ 956 on_each_cpu(drain_local_pages, NULL, 1); 957} 958 959#ifdef CONFIG_HIBERNATION 960 961void mark_free_pages(struct zone *zone) 962{ 963 unsigned long pfn, max_zone_pfn; 964 unsigned long flags; 965 int order, t; 966 struct list_head *curr; 967 968 if (!zone->spanned_pages) 969 return; 970 971 spin_lock_irqsave(&zone->lock, flags); 972 973 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; 974 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 975 if (pfn_valid(pfn)) { 976 struct page *page = pfn_to_page(pfn); 977 978 if (!swsusp_page_is_forbidden(page)) 979 swsusp_unset_page_free(page); 980 } 981 982 for_each_migratetype_order(order, t) { 983 list_for_each(curr, &zone->free_area[order].free_list[t]) { 984 unsigned long i; 985 986 pfn = page_to_pfn(list_entry(curr, struct page, lru)); 987 for (i = 0; i < (1UL << order); i++) 988 swsusp_set_page_free(pfn_to_page(pfn + i)); 989 } 990 } 991 spin_unlock_irqrestore(&zone->lock, flags); 992} 993#endif /* CONFIG_PM */ 994 995/* 996 * Free a 0-order page 997 */ 998static void free_hot_cold_page(struct page *page, int cold) 999{ 1000 struct zone *zone = page_zone(page); 1001 struct per_cpu_pages *pcp; 1002 unsigned long flags; 1003 1004 if (PageAnon(page)) 1005 page->mapping = NULL; 1006 if (free_pages_check(page)) 1007 return; 1008 1009 if (!PageHighMem(page)) { 1010 debug_check_no_locks_freed(page_address(page), PAGE_SIZE); 1011 debug_check_no_obj_freed(page_address(page), PAGE_SIZE); 1012 } 1013 arch_free_page(page, 0); 1014 kernel_map_pages(page, 1, 0); 1015 1016 pcp = &zone_pcp(zone, get_cpu())->pcp; 1017 local_irq_save(flags); 1018 __count_vm_event(PGFREE); 1019 if (cold) 1020 list_add_tail(&page->lru, &pcp->list); 1021 else 1022 list_add(&page->lru, &pcp->list); 1023 set_page_private(page, get_pageblock_migratetype(page)); 1024 pcp->count++; 1025 if (pcp->count >= pcp->high) { 1026 free_pages_bulk(zone, pcp->batch, &pcp->list, 0); 1027 pcp->count -= pcp->batch; 1028 } 1029 local_irq_restore(flags); 1030 put_cpu(); 1031} 1032 1033void free_hot_page(struct page *page) 1034{ 1035 free_hot_cold_page(page, 0); 1036} 1037 1038void free_cold_page(struct page *page) 1039{ 1040 free_hot_cold_page(page, 1); 1041} 1042 1043/* 1044 * split_page takes a non-compound higher-order page, and splits it into 1045 * n (1<<order) sub-pages: page[0..n] 1046 * Each sub-page must be freed individually. 1047 * 1048 * Note: this is probably too low level an operation for use in drivers. 1049 * Please consult with lkml before using this in your driver. 1050 */ 1051void split_page(struct page *page, unsigned int order) 1052{ 1053 int i; 1054 1055 VM_BUG_ON(PageCompound(page)); 1056 VM_BUG_ON(!page_count(page)); 1057 for (i = 1; i < (1 << order); i++) 1058 set_page_refcounted(page + i); 1059} 1060 1061/* 1062 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 1063 * we cheat by calling it from here, in the order > 0 path. Saves a branch 1064 * or two. 1065 */ 1066static struct page *buffered_rmqueue(struct zone *preferred_zone, 1067 struct zone *zone, int order, gfp_t gfp_flags) 1068{ 1069 unsigned long flags; 1070 struct page *page; 1071 int cold = !!(gfp_flags & __GFP_COLD); 1072 int cpu; 1073 int migratetype = allocflags_to_migratetype(gfp_flags); 1074 1075again: 1076 cpu = get_cpu(); 1077 if (likely(order == 0)) { 1078 struct per_cpu_pages *pcp; 1079 1080 pcp = &zone_pcp(zone, cpu)->pcp; 1081 local_irq_save(flags); 1082 if (!pcp->count) { 1083 pcp->count = rmqueue_bulk(zone, 0, 1084 pcp->batch, &pcp->list, migratetype); 1085 if (unlikely(!pcp->count)) 1086 goto failed; 1087 } 1088 1089 /* Find a page of the appropriate migrate type */ 1090 if (cold) { 1091 list_for_each_entry_reverse(page, &pcp->list, lru) 1092 if (page_private(page) == migratetype) 1093 break; 1094 } else { 1095 list_for_each_entry(page, &pcp->list, lru) 1096 if (page_private(page) == migratetype) 1097 break; 1098 } 1099 1100 /* Allocate more to the pcp list if necessary */ 1101 if (unlikely(&page->lru == &pcp->list)) { 1102 pcp->count += rmqueue_bulk(zone, 0, 1103 pcp->batch, &pcp->list, migratetype); 1104 page = list_entry(pcp->list.next, struct page, lru); 1105 } 1106 1107 list_del(&page->lru); 1108 pcp->count--; 1109 } else { 1110 spin_lock_irqsave(&zone->lock, flags); 1111 page = __rmqueue(zone, order, migratetype); 1112 spin_unlock(&zone->lock); 1113 if (!page) 1114 goto failed; 1115 } 1116 1117 __count_zone_vm_events(PGALLOC, zone, 1 << order); 1118 zone_statistics(preferred_zone, zone); 1119 local_irq_restore(flags); 1120 put_cpu(); 1121 1122 VM_BUG_ON(bad_range(zone, page)); 1123 if (prep_new_page(page, order, gfp_flags)) 1124 goto again; 1125 return page; 1126 1127failed: 1128 local_irq_restore(flags); 1129 put_cpu(); 1130 return NULL; 1131} 1132 1133#define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */ 1134#define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */ 1135#define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */ 1136#define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */ 1137#define ALLOC_HARDER 0x10 /* try to alloc harder */ 1138#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 1139#define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 1140 1141#ifdef CONFIG_FAIL_PAGE_ALLOC 1142 1143static struct fail_page_alloc_attr { 1144 struct fault_attr attr; 1145 1146 u32 ignore_gfp_highmem; 1147 u32 ignore_gfp_wait; 1148 u32 min_order; 1149 1150#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1151 1152 struct dentry *ignore_gfp_highmem_file; 1153 struct dentry *ignore_gfp_wait_file; 1154 struct dentry *min_order_file; 1155 1156#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1157 1158} fail_page_alloc = { 1159 .attr = FAULT_ATTR_INITIALIZER, 1160 .ignore_gfp_wait = 1, 1161 .ignore_gfp_highmem = 1, 1162 .min_order = 1, 1163}; 1164 1165static int __init setup_fail_page_alloc(char *str) 1166{ 1167 return setup_fault_attr(&fail_page_alloc.attr, str); 1168} 1169__setup("fail_page_alloc=", setup_fail_page_alloc); 1170 1171static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1172{ 1173 if (order < fail_page_alloc.min_order) 1174 return 0; 1175 if (gfp_mask & __GFP_NOFAIL) 1176 return 0; 1177 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 1178 return 0; 1179 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) 1180 return 0; 1181 1182 return should_fail(&fail_page_alloc.attr, 1 << order); 1183} 1184 1185#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1186 1187static int __init fail_page_alloc_debugfs(void) 1188{ 1189 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; 1190 struct dentry *dir; 1191 int err; 1192 1193 err = init_fault_attr_dentries(&fail_page_alloc.attr, 1194 "fail_page_alloc"); 1195 if (err) 1196 return err; 1197 dir = fail_page_alloc.attr.dentries.dir; 1198 1199 fail_page_alloc.ignore_gfp_wait_file = 1200 debugfs_create_bool("ignore-gfp-wait", mode, dir, 1201 &fail_page_alloc.ignore_gfp_wait); 1202 1203 fail_page_alloc.ignore_gfp_highmem_file = 1204 debugfs_create_bool("ignore-gfp-highmem", mode, dir, 1205 &fail_page_alloc.ignore_gfp_highmem); 1206 fail_page_alloc.min_order_file = 1207 debugfs_create_u32("min-order", mode, dir, 1208 &fail_page_alloc.min_order); 1209 1210 if (!fail_page_alloc.ignore_gfp_wait_file || 1211 !fail_page_alloc.ignore_gfp_highmem_file || 1212 !fail_page_alloc.min_order_file) { 1213 err = -ENOMEM; 1214 debugfs_remove(fail_page_alloc.ignore_gfp_wait_file); 1215 debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file); 1216 debugfs_remove(fail_page_alloc.min_order_file); 1217 cleanup_fault_attr_dentries(&fail_page_alloc.attr); 1218 } 1219 1220 return err; 1221} 1222 1223late_initcall(fail_page_alloc_debugfs); 1224 1225#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1226 1227#else /* CONFIG_FAIL_PAGE_ALLOC */ 1228 1229static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1230{ 1231 return 0; 1232} 1233 1234#endif /* CONFIG_FAIL_PAGE_ALLOC */ 1235 1236/* 1237 * Return 1 if free pages are above 'mark'. This takes into account the order 1238 * of the allocation. 1239 */ 1240int zone_watermark_ok(struct zone *z, int order, unsigned long mark, 1241 int classzone_idx, int alloc_flags) 1242{ 1243 /* free_pages my go negative - that's OK */ 1244 long min = mark; 1245 long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1; 1246 int o; 1247 1248 if (alloc_flags & ALLOC_HIGH) 1249 min -= min / 2; 1250 if (alloc_flags & ALLOC_HARDER) 1251 min -= min / 4; 1252 1253 if (free_pages <= min + z->lowmem_reserve[classzone_idx]) 1254 return 0; 1255 for (o = 0; o < order; o++) { 1256 /* At the next order, this order's pages become unavailable */ 1257 free_pages -= z->free_area[o].nr_free << o; 1258 1259 /* Require fewer higher order pages to be free */ 1260 min >>= 1; 1261 1262 if (free_pages <= min) 1263 return 0; 1264 } 1265 return 1; 1266} 1267 1268#ifdef CONFIG_NUMA 1269/* 1270 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to 1271 * skip over zones that are not allowed by the cpuset, or that have 1272 * been recently (in last second) found to be nearly full. See further 1273 * comments in mmzone.h. Reduces cache footprint of zonelist scans 1274 * that have to skip over a lot of full or unallowed zones. 1275 * 1276 * If the zonelist cache is present in the passed in zonelist, then 1277 * returns a pointer to the allowed node mask (either the current 1278 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].) 1279 * 1280 * If the zonelist cache is not available for this zonelist, does 1281 * nothing and returns NULL. 1282 * 1283 * If the fullzones BITMAP in the zonelist cache is stale (more than 1284 * a second since last zap'd) then we zap it out (clear its bits.) 1285 * 1286 * We hold off even calling zlc_setup, until after we've checked the 1287 * first zone in the zonelist, on the theory that most allocations will 1288 * be satisfied from that first zone, so best to examine that zone as 1289 * quickly as we can. 1290 */ 1291static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1292{ 1293 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1294 nodemask_t *allowednodes; /* zonelist_cache approximation */ 1295 1296 zlc = zonelist->zlcache_ptr; 1297 if (!zlc) 1298 return NULL; 1299 1300 if (time_after(jiffies, zlc->last_full_zap + HZ)) { 1301 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1302 zlc->last_full_zap = jiffies; 1303 } 1304 1305 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? 1306 &cpuset_current_mems_allowed : 1307 &node_states[N_HIGH_MEMORY]; 1308 return allowednodes; 1309} 1310 1311/* 1312 * Given 'z' scanning a zonelist, run a couple of quick checks to see 1313 * if it is worth looking at further for free memory: 1314 * 1) Check that the zone isn't thought to be full (doesn't have its 1315 * bit set in the zonelist_cache fullzones BITMAP). 1316 * 2) Check that the zones node (obtained from the zonelist_cache 1317 * z_to_n[] mapping) is allowed in the passed in allowednodes mask. 1318 * Return true (non-zero) if zone is worth looking at further, or 1319 * else return false (zero) if it is not. 1320 * 1321 * This check -ignores- the distinction between various watermarks, 1322 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is 1323 * found to be full for any variation of these watermarks, it will 1324 * be considered full for up to one second by all requests, unless 1325 * we are so low on memory on all allowed nodes that we are forced 1326 * into the second scan of the zonelist. 1327 * 1328 * In the second scan we ignore this zonelist cache and exactly 1329 * apply the watermarks to all zones, even it is slower to do so. 1330 * We are low on memory in the second scan, and should leave no stone 1331 * unturned looking for a free page. 1332 */ 1333static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1334 nodemask_t *allowednodes) 1335{ 1336 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1337 int i; /* index of *z in zonelist zones */ 1338 int n; /* node that zone *z is on */ 1339 1340 zlc = zonelist->zlcache_ptr; 1341 if (!zlc) 1342 return 1; 1343 1344 i = z - zonelist->_zonerefs; 1345 n = zlc->z_to_n[i]; 1346 1347 /* This zone is worth trying if it is allowed but not full */ 1348 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); 1349} 1350 1351/* 1352 * Given 'z' scanning a zonelist, set the corresponding bit in 1353 * zlc->fullzones, so that subsequent attempts to allocate a page 1354 * from that zone don't waste time re-examining it. 1355 */ 1356static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1357{ 1358 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1359 int i; /* index of *z in zonelist zones */ 1360 1361 zlc = zonelist->zlcache_ptr; 1362 if (!zlc) 1363 return; 1364 1365 i = z - zonelist->_zonerefs; 1366 1367 set_bit(i, zlc->fullzones); 1368} 1369 1370#else /* CONFIG_NUMA */ 1371 1372static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1373{ 1374 return NULL; 1375} 1376 1377static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1378 nodemask_t *allowednodes) 1379{ 1380 return 1; 1381} 1382 1383static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1384{ 1385} 1386#endif /* CONFIG_NUMA */ 1387 1388/* 1389 * get_page_from_freelist goes through the zonelist trying to allocate 1390 * a page. 1391 */ 1392static struct page * 1393get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order, 1394 struct zonelist *zonelist, int high_zoneidx, int alloc_flags) 1395{ 1396 struct zoneref *z; 1397 struct page *page = NULL; 1398 int classzone_idx; 1399 struct zone *zone, *preferred_zone; 1400 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ 1401 int zlc_active = 0; /* set if using zonelist_cache */ 1402 int did_zlc_setup = 0; /* just call zlc_setup() one time */ 1403 1404 (void)first_zones_zonelist(zonelist, high_zoneidx, nodemask, 1405 &preferred_zone); 1406 if (!preferred_zone) 1407 return NULL; 1408 1409 classzone_idx = zone_idx(preferred_zone); 1410 1411zonelist_scan: 1412 /* 1413 * Scan zonelist, looking for a zone with enough free. 1414 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1415 */ 1416 for_each_zone_zonelist_nodemask(zone, z, zonelist, 1417 high_zoneidx, nodemask) { 1418 if (NUMA_BUILD && zlc_active && 1419 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 1420 continue; 1421 if ((alloc_flags & ALLOC_CPUSET) && 1422 !cpuset_zone_allowed_softwall(zone, gfp_mask)) 1423 goto try_next_zone; 1424 1425 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { 1426 unsigned long mark; 1427 if (alloc_flags & ALLOC_WMARK_MIN) 1428 mark = zone->pages_min; 1429 else if (alloc_flags & ALLOC_WMARK_LOW) 1430 mark = zone->pages_low; 1431 else 1432 mark = zone->pages_high; 1433 if (!zone_watermark_ok(zone, order, mark, 1434 classzone_idx, alloc_flags)) { 1435 if (!zone_reclaim_mode || 1436 !zone_reclaim(zone, gfp_mask, order)) 1437 goto this_zone_full; 1438 } 1439 } 1440 1441 page = buffered_rmqueue(preferred_zone, zone, order, gfp_mask); 1442 if (page) 1443 break; 1444this_zone_full: 1445 if (NUMA_BUILD) 1446 zlc_mark_zone_full(zonelist, z); 1447try_next_zone: 1448 if (NUMA_BUILD && !did_zlc_setup) { 1449 /* we do zlc_setup after the first zone is tried */ 1450 allowednodes = zlc_setup(zonelist, alloc_flags); 1451 zlc_active = 1; 1452 did_zlc_setup = 1; 1453 } 1454 } 1455 1456 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) { 1457 /* Disable zlc cache for second zonelist scan */ 1458 zlc_active = 0; 1459 goto zonelist_scan; 1460 } 1461 return page; 1462} 1463 1464/* 1465 * This is the 'heart' of the zoned buddy allocator. 1466 */ 1467struct page * 1468__alloc_pages_internal(gfp_t gfp_mask, unsigned int order, 1469 struct zonelist *zonelist, nodemask_t *nodemask) 1470{ 1471 const gfp_t wait = gfp_mask & __GFP_WAIT; 1472 enum zone_type high_zoneidx = gfp_zone(gfp_mask); 1473 struct zoneref *z; 1474 struct zone *zone; 1475 struct page *page; 1476 struct reclaim_state reclaim_state; 1477 struct task_struct *p = current; 1478 int do_retry; 1479 int alloc_flags; 1480 unsigned long did_some_progress; 1481 unsigned long pages_reclaimed = 0; 1482 1483 might_sleep_if(wait); 1484 1485 if (should_fail_alloc_page(gfp_mask, order)) 1486 return NULL; 1487 1488restart: 1489 z = zonelist->_zonerefs; /* the list of zones suitable for gfp_mask */ 1490 1491 if (unlikely(!z->zone)) { 1492 /* 1493 * Happens if we have an empty zonelist as a result of 1494 * GFP_THISNODE being used on a memoryless node 1495 */ 1496 return NULL; 1497 } 1498 1499 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order, 1500 zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET); 1501 if (page) 1502 goto got_pg; 1503 1504 /* 1505 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and 1506 * __GFP_NOWARN set) should not cause reclaim since the subsystem 1507 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim 1508 * using a larger set of nodes after it has established that the 1509 * allowed per node queues are empty and that nodes are 1510 * over allocated. 1511 */ 1512 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) 1513 goto nopage; 1514 1515 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) 1516 wakeup_kswapd(zone, order); 1517 1518 /* 1519 * OK, we're below the kswapd watermark and have kicked background 1520 * reclaim. Now things get more complex, so set up alloc_flags according 1521 * to how we want to proceed. 1522 * 1523 * The caller may dip into page reserves a bit more if the caller 1524 * cannot run direct reclaim, or if the caller has realtime scheduling 1525 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will 1526 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). 1527 */ 1528 alloc_flags = ALLOC_WMARK_MIN; 1529 if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait) 1530 alloc_flags |= ALLOC_HARDER; 1531 if (gfp_mask & __GFP_HIGH) 1532 alloc_flags |= ALLOC_HIGH; 1533 if (wait) 1534 alloc_flags |= ALLOC_CPUSET; 1535 1536 /* 1537 * Go through the zonelist again. Let __GFP_HIGH and allocations 1538 * coming from realtime tasks go deeper into reserves. 1539 * 1540 * This is the last chance, in general, before the goto nopage. 1541 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. 1542 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1543 */ 1544 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, 1545 high_zoneidx, alloc_flags); 1546 if (page) 1547 goto got_pg; 1548 1549 /* This allocation should allow future memory freeing. */ 1550 1551rebalance: 1552 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) 1553 && !in_interrupt()) { 1554 if (!(gfp_mask & __GFP_NOMEMALLOC)) { 1555nofail_alloc: 1556 /* go through the zonelist yet again, ignoring mins */ 1557 page = get_page_from_freelist(gfp_mask, nodemask, order, 1558 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS); 1559 if (page) 1560 goto got_pg; 1561 if (gfp_mask & __GFP_NOFAIL) { 1562 congestion_wait(WRITE, HZ/50); 1563 goto nofail_alloc; 1564 } 1565 } 1566 goto nopage; 1567 } 1568 1569 /* Atomic allocations - we can't balance anything */ 1570 if (!wait) 1571 goto nopage; 1572 1573 cond_resched(); 1574 1575 /* We now go into synchronous reclaim */ 1576 cpuset_memory_pressure_bump(); 1577 /* 1578 * The task's cpuset might have expanded its set of allowable nodes 1579 */ 1580 cpuset_update_task_memory_state(); 1581 p->flags |= PF_MEMALLOC; 1582 reclaim_state.reclaimed_slab = 0; 1583 p->reclaim_state = &reclaim_state; 1584 1585 did_some_progress = try_to_free_pages(zonelist, order, gfp_mask); 1586 1587 p->reclaim_state = NULL; 1588 p->flags &= ~PF_MEMALLOC; 1589 1590 cond_resched(); 1591 1592 if (order != 0) 1593 drain_all_pages(); 1594 1595 if (likely(did_some_progress)) { 1596 page = get_page_from_freelist(gfp_mask, nodemask, order, 1597 zonelist, high_zoneidx, alloc_flags); 1598 if (page) 1599 goto got_pg; 1600 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { 1601 if (!try_set_zone_oom(zonelist, gfp_mask)) { 1602 schedule_timeout_uninterruptible(1); 1603 goto restart; 1604 } 1605 1606 /* 1607 * Go through the zonelist yet one more time, keep 1608 * very high watermark here, this is only to catch 1609 * a parallel oom killing, we must fail if we're still 1610 * under heavy pressure. 1611 */ 1612 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, 1613 order, zonelist, high_zoneidx, 1614 ALLOC_WMARK_HIGH|ALLOC_CPUSET); 1615 if (page) { 1616 clear_zonelist_oom(zonelist, gfp_mask); 1617 goto got_pg; 1618 } 1619 1620 /* The OOM killer will not help higher order allocs so fail */ 1621 if (order > PAGE_ALLOC_COSTLY_ORDER) { 1622 clear_zonelist_oom(zonelist, gfp_mask); 1623 goto nopage; 1624 } 1625 1626 out_of_memory(zonelist, gfp_mask, order); 1627 clear_zonelist_oom(zonelist, gfp_mask); 1628 goto restart; 1629 } 1630 1631 /* 1632 * Don't let big-order allocations loop unless the caller explicitly 1633 * requests that. Wait for some write requests to complete then retry. 1634 * 1635 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER 1636 * means __GFP_NOFAIL, but that may not be true in other 1637 * implementations. 1638 * 1639 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is 1640 * specified, then we retry until we no longer reclaim any pages 1641 * (above), or we've reclaimed an order of pages at least as 1642 * large as the allocation's order. In both cases, if the 1643 * allocation still fails, we stop retrying. 1644 */ 1645 pages_reclaimed += did_some_progress; 1646 do_retry = 0; 1647 if (!(gfp_mask & __GFP_NORETRY)) { 1648 if (order <= PAGE_ALLOC_COSTLY_ORDER) { 1649 do_retry = 1; 1650 } else { 1651 if (gfp_mask & __GFP_REPEAT && 1652 pages_reclaimed < (1 << order)) 1653 do_retry = 1; 1654 } 1655 if (gfp_mask & __GFP_NOFAIL) 1656 do_retry = 1; 1657 } 1658 if (do_retry) { 1659 congestion_wait(WRITE, HZ/50); 1660 goto rebalance; 1661 } 1662 1663nopage: 1664 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { 1665 printk(KERN_WARNING "%s: page allocation failure." 1666 " order:%d, mode:0x%x\n", 1667 p->comm, order, gfp_mask); 1668 dump_stack(); 1669 show_mem(); 1670 } 1671got_pg: 1672 return page; 1673} 1674EXPORT_SYMBOL(__alloc_pages_internal); 1675 1676/* 1677 * Common helper functions. 1678 */ 1679unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 1680{ 1681 struct page * page; 1682 page = alloc_pages(gfp_mask, order); 1683 if (!page) 1684 return 0; 1685 return (unsigned long) page_address(page); 1686} 1687 1688EXPORT_SYMBOL(__get_free_pages); 1689 1690unsigned long get_zeroed_page(gfp_t gfp_mask) 1691{ 1692 struct page * page; 1693 1694 /* 1695 * get_zeroed_page() returns a 32-bit address, which cannot represent 1696 * a highmem page 1697 */ 1698 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 1699 1700 page = alloc_pages(gfp_mask | __GFP_ZERO, 0); 1701 if (page) 1702 return (unsigned long) page_address(page); 1703 return 0; 1704} 1705 1706EXPORT_SYMBOL(get_zeroed_page); 1707 1708void __pagevec_free(struct pagevec *pvec) 1709{ 1710 int i = pagevec_count(pvec); 1711 1712 while (--i >= 0) 1713 free_hot_cold_page(pvec->pages[i], pvec->cold); 1714} 1715 1716void __free_pages(struct page *page, unsigned int order) 1717{ 1718 if (put_page_testzero(page)) { 1719 if (order == 0) 1720 free_hot_page(page); 1721 else 1722 __free_pages_ok(page, order); 1723 } 1724} 1725 1726EXPORT_SYMBOL(__free_pages); 1727 1728void free_pages(unsigned long addr, unsigned int order) 1729{ 1730 if (addr != 0) { 1731 VM_BUG_ON(!virt_addr_valid((void *)addr)); 1732 __free_pages(virt_to_page((void *)addr), order); 1733 } 1734} 1735 1736EXPORT_SYMBOL(free_pages); 1737 1738/** 1739 * alloc_pages_exact - allocate an exact number physically-contiguous pages. 1740 * @size: the number of bytes to allocate 1741 * @gfp_mask: GFP flags for the allocation 1742 * 1743 * This function is similar to alloc_pages(), except that it allocates the 1744 * minimum number of pages to satisfy the request. alloc_pages() can only 1745 * allocate memory in power-of-two pages. 1746 * 1747 * This function is also limited by MAX_ORDER. 1748 * 1749 * Memory allocated by this function must be released by free_pages_exact(). 1750 */ 1751void *alloc_pages_exact(size_t size, gfp_t gfp_mask) 1752{ 1753 unsigned int order = get_order(size); 1754 unsigned long addr; 1755 1756 addr = __get_free_pages(gfp_mask, order); 1757 if (addr) { 1758 unsigned long alloc_end = addr + (PAGE_SIZE << order); 1759 unsigned long used = addr + PAGE_ALIGN(size); 1760 1761 split_page(virt_to_page(addr), order); 1762 while (used < alloc_end) { 1763 free_page(used); 1764 used += PAGE_SIZE; 1765 } 1766 } 1767 1768 return (void *)addr; 1769} 1770EXPORT_SYMBOL(alloc_pages_exact); 1771 1772/** 1773 * free_pages_exact - release memory allocated via alloc_pages_exact() 1774 * @virt: the value returned by alloc_pages_exact. 1775 * @size: size of allocation, same value as passed to alloc_pages_exact(). 1776 * 1777 * Release the memory allocated by a previous call to alloc_pages_exact. 1778 */ 1779void free_pages_exact(void *virt, size_t size) 1780{ 1781 unsigned long addr = (unsigned long)virt; 1782 unsigned long end = addr + PAGE_ALIGN(size); 1783 1784 while (addr < end) { 1785 free_page(addr); 1786 addr += PAGE_SIZE; 1787 } 1788} 1789EXPORT_SYMBOL(free_pages_exact); 1790 1791static unsigned int nr_free_zone_pages(int offset) 1792{ 1793 struct zoneref *z; 1794 struct zone *zone; 1795 1796 /* Just pick one node, since fallback list is circular */ 1797 unsigned int sum = 0; 1798 1799 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); 1800 1801 for_each_zone_zonelist(zone, z, zonelist, offset) { 1802 unsigned long size = zone->present_pages; 1803 unsigned long high = zone->pages_high; 1804 if (size > high) 1805 sum += size - high; 1806 } 1807 1808 return sum; 1809} 1810 1811/* 1812 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL 1813 */ 1814unsigned int nr_free_buffer_pages(void) 1815{ 1816 return nr_free_zone_pages(gfp_zone(GFP_USER)); 1817} 1818EXPORT_SYMBOL_GPL(nr_free_buffer_pages); 1819 1820/* 1821 * Amount of free RAM allocatable within all zones 1822 */ 1823unsigned int nr_free_pagecache_pages(void) 1824{ 1825 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); 1826} 1827 1828static inline void show_node(struct zone *zone) 1829{ 1830 if (NUMA_BUILD) 1831 printk("Node %d ", zone_to_nid(zone)); 1832} 1833 1834void si_meminfo(struct sysinfo *val) 1835{ 1836 val->totalram = totalram_pages; 1837 val->sharedram = 0; 1838 val->freeram = global_page_state(NR_FREE_PAGES); 1839 val->bufferram = nr_blockdev_pages(); 1840 val->totalhigh = totalhigh_pages; 1841 val->freehigh = nr_free_highpages(); 1842 val->mem_unit = PAGE_SIZE; 1843} 1844 1845EXPORT_SYMBOL(si_meminfo); 1846 1847#ifdef CONFIG_NUMA 1848void si_meminfo_node(struct sysinfo *val, int nid) 1849{ 1850 pg_data_t *pgdat = NODE_DATA(nid); 1851 1852 val->totalram = pgdat->node_present_pages; 1853 val->freeram = node_page_state(nid, NR_FREE_PAGES); 1854#ifdef CONFIG_HIGHMEM 1855 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; 1856 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], 1857 NR_FREE_PAGES); 1858#else 1859 val->totalhigh = 0; 1860 val->freehigh = 0; 1861#endif 1862 val->mem_unit = PAGE_SIZE; 1863} 1864#endif 1865 1866#define K(x) ((x) << (PAGE_SHIFT-10)) 1867 1868/* 1869 * Show free area list (used inside shift_scroll-lock stuff) 1870 * We also calculate the percentage fragmentation. We do this by counting the 1871 * memory on each free list with the exception of the first item on the list. 1872 */ 1873void show_free_areas(void) 1874{ 1875 int cpu; 1876 struct zone *zone; 1877 1878 for_each_zone(zone) { 1879 if (!populated_zone(zone)) 1880 continue; 1881 1882 show_node(zone); 1883 printk("%s per-cpu:\n", zone->name); 1884 1885 for_each_online_cpu(cpu) { 1886 struct per_cpu_pageset *pageset; 1887 1888 pageset = zone_pcp(zone, cpu); 1889 1890 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n", 1891 cpu, pageset->pcp.high, 1892 pageset->pcp.batch, pageset->pcp.count); 1893 } 1894 } 1895 1896 printk("Active_anon:%lu active_file:%lu inactive_anon:%lu\n" 1897 " inactive_file:%lu" 1898//TODO: check/adjust line lengths 1899#ifdef CONFIG_UNEVICTABLE_LRU 1900 " unevictable:%lu" 1901#endif 1902 " dirty:%lu writeback:%lu unstable:%lu\n" 1903 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n", 1904 global_page_state(NR_ACTIVE_ANON), 1905 global_page_state(NR_ACTIVE_FILE), 1906 global_page_state(NR_INACTIVE_ANON), 1907 global_page_state(NR_INACTIVE_FILE), 1908#ifdef CONFIG_UNEVICTABLE_LRU 1909 global_page_state(NR_UNEVICTABLE), 1910#endif 1911 global_page_state(NR_FILE_DIRTY), 1912 global_page_state(NR_WRITEBACK), 1913 global_page_state(NR_UNSTABLE_NFS), 1914 global_page_state(NR_FREE_PAGES), 1915 global_page_state(NR_SLAB_RECLAIMABLE) + 1916 global_page_state(NR_SLAB_UNRECLAIMABLE), 1917 global_page_state(NR_FILE_MAPPED), 1918 global_page_state(NR_PAGETABLE), 1919 global_page_state(NR_BOUNCE)); 1920 1921 for_each_zone(zone) { 1922 int i; 1923 1924 if (!populated_zone(zone)) 1925 continue; 1926 1927 show_node(zone); 1928 printk("%s" 1929 " free:%lukB" 1930 " min:%lukB" 1931 " low:%lukB" 1932 " high:%lukB" 1933 " active_anon:%lukB" 1934 " inactive_anon:%lukB" 1935 " active_file:%lukB" 1936 " inactive_file:%lukB" 1937#ifdef CONFIG_UNEVICTABLE_LRU 1938 " unevictable:%lukB" 1939#endif 1940 " present:%lukB" 1941 " pages_scanned:%lu" 1942 " all_unreclaimable? %s" 1943 "\n", 1944 zone->name, 1945 K(zone_page_state(zone, NR_FREE_PAGES)), 1946 K(zone->pages_min), 1947 K(zone->pages_low), 1948 K(zone->pages_high), 1949 K(zone_page_state(zone, NR_ACTIVE_ANON)), 1950 K(zone_page_state(zone, NR_INACTIVE_ANON)), 1951 K(zone_page_state(zone, NR_ACTIVE_FILE)), 1952 K(zone_page_state(zone, NR_INACTIVE_FILE)), 1953#ifdef CONFIG_UNEVICTABLE_LRU 1954 K(zone_page_state(zone, NR_UNEVICTABLE)), 1955#endif 1956 K(zone->present_pages), 1957 zone->pages_scanned, 1958 (zone_is_all_unreclaimable(zone) ? "yes" : "no") 1959 ); 1960 printk("lowmem_reserve[]:"); 1961 for (i = 0; i < MAX_NR_ZONES; i++) 1962 printk(" %lu", zone->lowmem_reserve[i]); 1963 printk("\n"); 1964 } 1965 1966 for_each_zone(zone) { 1967 unsigned long nr[MAX_ORDER], flags, order, total = 0; 1968 1969 if (!populated_zone(zone)) 1970 continue; 1971 1972 show_node(zone); 1973 printk("%s: ", zone->name); 1974 1975 spin_lock_irqsave(&zone->lock, flags); 1976 for (order = 0; order < MAX_ORDER; order++) { 1977 nr[order] = zone->free_area[order].nr_free; 1978 total += nr[order] << order; 1979 } 1980 spin_unlock_irqrestore(&zone->lock, flags); 1981 for (order = 0; order < MAX_ORDER; order++) 1982 printk("%lu*%lukB ", nr[order], K(1UL) << order); 1983 printk("= %lukB\n", K(total)); 1984 } 1985 1986 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES)); 1987 1988 show_swap_cache_info(); 1989} 1990 1991static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) 1992{ 1993 zoneref->zone = zone; 1994 zoneref->zone_idx = zone_idx(zone); 1995} 1996 1997/* 1998 * Builds allocation fallback zone lists. 1999 * 2000 * Add all populated zones of a node to the zonelist. 2001 */ 2002static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, 2003 int nr_zones, enum zone_type zone_type) 2004{ 2005 struct zone *zone; 2006 2007 BUG_ON(zone_type >= MAX_NR_ZONES); 2008 zone_type++; 2009 2010 do { 2011 zone_type--; 2012 zone = pgdat->node_zones + zone_type; 2013 if (populated_zone(zone)) { 2014 zoneref_set_zone(zone, 2015 &zonelist->_zonerefs[nr_zones++]); 2016 check_highest_zone(zone_type); 2017 } 2018 2019 } while (zone_type); 2020 return nr_zones; 2021} 2022 2023 2024/* 2025 * zonelist_order: 2026 * 0 = automatic detection of better ordering. 2027 * 1 = order by ([node] distance, -zonetype) 2028 * 2 = order by (-zonetype, [node] distance) 2029 * 2030 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create 2031 * the same zonelist. So only NUMA can configure this param. 2032 */ 2033#define ZONELIST_ORDER_DEFAULT 0 2034#define ZONELIST_ORDER_NODE 1 2035#define ZONELIST_ORDER_ZONE 2 2036 2037/* zonelist order in the kernel. 2038 * set_zonelist_order() will set this to NODE or ZONE. 2039 */ 2040static int current_zonelist_order = ZONELIST_ORDER_DEFAULT; 2041static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"}; 2042 2043 2044#ifdef CONFIG_NUMA 2045/* The value user specified ....changed by config */ 2046static int user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2047/* string for sysctl */ 2048#define NUMA_ZONELIST_ORDER_LEN 16 2049char numa_zonelist_order[16] = "default"; 2050 2051/* 2052 * interface for configure zonelist ordering. 2053 * command line option "numa_zonelist_order" 2054 * = "[dD]efault - default, automatic configuration. 2055 * = "[nN]ode - order by node locality, then by zone within node 2056 * = "[zZ]one - order by zone, then by locality within zone 2057 */ 2058 2059static int __parse_numa_zonelist_order(char *s) 2060{ 2061 if (*s == 'd' || *s == 'D') { 2062 user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2063 } else if (*s == 'n' || *s == 'N') { 2064 user_zonelist_order = ZONELIST_ORDER_NODE; 2065 } else if (*s == 'z' || *s == 'Z') { 2066 user_zonelist_order = ZONELIST_ORDER_ZONE; 2067 } else { 2068 printk(KERN_WARNING 2069 "Ignoring invalid numa_zonelist_order value: " 2070 "%s\n", s); 2071 return -EINVAL; 2072 } 2073 return 0; 2074} 2075 2076static __init int setup_numa_zonelist_order(char *s) 2077{ 2078 if (s) 2079 return __parse_numa_zonelist_order(s); 2080 return 0; 2081} 2082early_param("numa_zonelist_order", setup_numa_zonelist_order); 2083 2084/* 2085 * sysctl handler for numa_zonelist_order 2086 */ 2087int numa_zonelist_order_handler(ctl_table *table, int write, 2088 struct file *file, void __user *buffer, size_t *length, 2089 loff_t *ppos) 2090{ 2091 char saved_string[NUMA_ZONELIST_ORDER_LEN]; 2092 int ret; 2093 2094 if (write) 2095 strncpy(saved_string, (char*)table->data, 2096 NUMA_ZONELIST_ORDER_LEN); 2097 ret = proc_dostring(table, write, file, buffer, length, ppos); 2098 if (ret) 2099 return ret; 2100 if (write) { 2101 int oldval = user_zonelist_order; 2102 if (__parse_numa_zonelist_order((char*)table->data)) { 2103 /* 2104 * bogus value. restore saved string 2105 */ 2106 strncpy((char*)table->data, saved_string, 2107 NUMA_ZONELIST_ORDER_LEN); 2108 user_zonelist_order = oldval; 2109 } else if (oldval != user_zonelist_order) 2110 build_all_zonelists(); 2111 } 2112 return 0; 2113} 2114 2115 2116#define MAX_NODE_LOAD (num_online_nodes()) 2117static int node_load[MAX_NUMNODES]; 2118 2119/** 2120 * find_next_best_node - find the next node that should appear in a given node's fallback list 2121 * @node: node whose fallback list we're appending 2122 * @used_node_mask: nodemask_t of already used nodes 2123 * 2124 * We use a number of factors to determine which is the next node that should 2125 * appear on a given node's fallback list. The node should not have appeared 2126 * already in @node's fallback list, and it should be the next closest node 2127 * according to the distance array (which contains arbitrary distance values 2128 * from each node to each node in the system), and should also prefer nodes 2129 * with no CPUs, since presumably they'll have very little allocation pressure 2130 * on them otherwise. 2131 * It returns -1 if no node is found. 2132 */ 2133static int find_next_best_node(int node, nodemask_t *used_node_mask) 2134{ 2135 int n, val; 2136 int min_val = INT_MAX; 2137 int best_node = -1; 2138 node_to_cpumask_ptr(tmp, 0); 2139 2140 /* Use the local node if we haven't already */ 2141 if (!node_isset(node, *used_node_mask)) { 2142 node_set(node, *used_node_mask); 2143 return node; 2144 } 2145 2146 for_each_node_state(n, N_HIGH_MEMORY) { 2147 2148 /* Don't want a node to appear more than once */ 2149 if (node_isset(n, *used_node_mask)) 2150 continue; 2151 2152 /* Use the distance array to find the distance */ 2153 val = node_distance(node, n); 2154 2155 /* Penalize nodes under us ("prefer the next node") */ 2156 val += (n < node); 2157 2158 /* Give preference to headless and unused nodes */ 2159 node_to_cpumask_ptr_next(tmp, n); 2160 if (!cpus_empty(*tmp)) 2161 val += PENALTY_FOR_NODE_WITH_CPUS; 2162 2163 /* Slight preference for less loaded node */ 2164 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 2165 val += node_load[n]; 2166 2167 if (val < min_val) { 2168 min_val = val; 2169 best_node = n; 2170 } 2171 } 2172 2173 if (best_node >= 0) 2174 node_set(best_node, *used_node_mask); 2175 2176 return best_node; 2177} 2178 2179 2180/* 2181 * Build zonelists ordered by node and zones within node. 2182 * This results in maximum locality--normal zone overflows into local 2183 * DMA zone, if any--but risks exhausting DMA zone. 2184 */ 2185static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) 2186{ 2187 int j; 2188 struct zonelist *zonelist; 2189 2190 zonelist = &pgdat->node_zonelists[0]; 2191 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++) 2192 ; 2193 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2194 MAX_NR_ZONES - 1); 2195 zonelist->_zonerefs[j].zone = NULL; 2196 zonelist->_zonerefs[j].zone_idx = 0; 2197} 2198 2199/* 2200 * Build gfp_thisnode zonelists 2201 */ 2202static void build_thisnode_zonelists(pg_data_t *pgdat) 2203{ 2204 int j; 2205 struct zonelist *zonelist; 2206 2207 zonelist = &pgdat->node_zonelists[1]; 2208 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2209 zonelist->_zonerefs[j].zone = NULL; 2210 zonelist->_zonerefs[j].zone_idx = 0; 2211} 2212 2213/* 2214 * Build zonelists ordered by zone and nodes within zones. 2215 * This results in conserving DMA zone[s] until all Normal memory is 2216 * exhausted, but results in overflowing to remote node while memory 2217 * may still exist in local DMA zone. 2218 */ 2219static int node_order[MAX_NUMNODES]; 2220 2221static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) 2222{ 2223 int pos, j, node; 2224 int zone_type; /* needs to be signed */ 2225 struct zone *z; 2226 struct zonelist *zonelist; 2227 2228 zonelist = &pgdat->node_zonelists[0]; 2229 pos = 0; 2230 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) { 2231 for (j = 0; j < nr_nodes; j++) { 2232 node = node_order[j]; 2233 z = &NODE_DATA(node)->node_zones[zone_type]; 2234 if (populated_zone(z)) { 2235 zoneref_set_zone(z, 2236 &zonelist->_zonerefs[pos++]); 2237 check_highest_zone(zone_type); 2238 } 2239 } 2240 } 2241 zonelist->_zonerefs[pos].zone = NULL; 2242 zonelist->_zonerefs[pos].zone_idx = 0; 2243} 2244 2245static int default_zonelist_order(void) 2246{ 2247 int nid, zone_type; 2248 unsigned long low_kmem_size,total_size; 2249 struct zone *z; 2250 int average_size; 2251 /* 2252 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem. 2253 * If they are really small and used heavily, the system can fall 2254 * into OOM very easily. 2255 * This function detect ZONE_DMA/DMA32 size and confgigures zone order. 2256 */ 2257 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */ 2258 low_kmem_size = 0; 2259 total_size = 0; 2260 for_each_online_node(nid) { 2261 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2262 z = &NODE_DATA(nid)->node_zones[zone_type]; 2263 if (populated_zone(z)) { 2264 if (zone_type < ZONE_NORMAL) 2265 low_kmem_size += z->present_pages; 2266 total_size += z->present_pages; 2267 } 2268 } 2269 } 2270 if (!low_kmem_size || /* there are no DMA area. */ 2271 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */ 2272 return ZONELIST_ORDER_NODE; 2273 /* 2274 * look into each node's config. 2275 * If there is a node whose DMA/DMA32 memory is very big area on 2276 * local memory, NODE_ORDER may be suitable. 2277 */ 2278 average_size = total_size / 2279 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1); 2280 for_each_online_node(nid) { 2281 low_kmem_size = 0; 2282 total_size = 0; 2283 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2284 z = &NODE_DATA(nid)->node_zones[zone_type]; 2285 if (populated_zone(z)) { 2286 if (zone_type < ZONE_NORMAL) 2287 low_kmem_size += z->present_pages; 2288 total_size += z->present_pages; 2289 } 2290 } 2291 if (low_kmem_size && 2292 total_size > average_size && /* ignore small node */ 2293 low_kmem_size > total_size * 70/100) 2294 return ZONELIST_ORDER_NODE; 2295 } 2296 return ZONELIST_ORDER_ZONE; 2297} 2298 2299static void set_zonelist_order(void) 2300{ 2301 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT) 2302 current_zonelist_order = default_zonelist_order(); 2303 else 2304 current_zonelist_order = user_zonelist_order; 2305} 2306 2307static void build_zonelists(pg_data_t *pgdat) 2308{ 2309 int j, node, load; 2310 enum zone_type i; 2311 nodemask_t used_mask; 2312 int local_node, prev_node; 2313 struct zonelist *zonelist; 2314 int order = current_zonelist_order; 2315 2316 /* initialize zonelists */ 2317 for (i = 0; i < MAX_ZONELISTS; i++) { 2318 zonelist = pgdat->node_zonelists + i; 2319 zonelist->_zonerefs[0].zone = NULL; 2320 zonelist->_zonerefs[0].zone_idx = 0; 2321 } 2322 2323 /* NUMA-aware ordering of nodes */ 2324 local_node = pgdat->node_id; 2325 load = num_online_nodes(); 2326 prev_node = local_node; 2327 nodes_clear(used_mask); 2328 2329 memset(node_load, 0, sizeof(node_load)); 2330 memset(node_order, 0, sizeof(node_order)); 2331 j = 0; 2332 2333 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 2334 int distance = node_distance(local_node, node); 2335 2336 /* 2337 * If another node is sufficiently far away then it is better 2338 * to reclaim pages in a zone before going off node. 2339 */ 2340 if (distance > RECLAIM_DISTANCE) 2341 zone_reclaim_mode = 1; 2342 2343 /* 2344 * We don't want to pressure a particular node. 2345 * So adding penalty to the first node in same 2346 * distance group to make it round-robin. 2347 */ 2348 if (distance != node_distance(local_node, prev_node)) 2349 node_load[node] = load; 2350 2351 prev_node = node; 2352 load--; 2353 if (order == ZONELIST_ORDER_NODE) 2354 build_zonelists_in_node_order(pgdat, node); 2355 else 2356 node_order[j++] = node; /* remember order */ 2357 } 2358 2359 if (order == ZONELIST_ORDER_ZONE) { 2360 /* calculate node order -- i.e., DMA last! */ 2361 build_zonelists_in_zone_order(pgdat, j); 2362 } 2363 2364 build_thisnode_zonelists(pgdat); 2365} 2366 2367/* Construct the zonelist performance cache - see further mmzone.h */ 2368static void build_zonelist_cache(pg_data_t *pgdat) 2369{ 2370 struct zonelist *zonelist; 2371 struct zonelist_cache *zlc; 2372 struct zoneref *z; 2373 2374 zonelist = &pgdat->node_zonelists[0]; 2375 zonelist->zlcache_ptr = zlc = &zonelist->zlcache; 2376 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 2377 for (z = zonelist->_zonerefs; z->zone; z++) 2378 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z); 2379} 2380 2381 2382#else /* CONFIG_NUMA */ 2383 2384static void set_zonelist_order(void) 2385{ 2386 current_zonelist_order = ZONELIST_ORDER_ZONE; 2387} 2388 2389static void build_zonelists(pg_data_t *pgdat) 2390{ 2391 int node, local_node; 2392 enum zone_type j; 2393 struct zonelist *zonelist; 2394 2395 local_node = pgdat->node_id; 2396 2397 zonelist = &pgdat->node_zonelists[0]; 2398 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2399 2400 /* 2401 * Now we build the zonelist so that it contains the zones 2402 * of all the other nodes. 2403 * We don't want to pressure a particular node, so when 2404 * building the zones for node N, we make sure that the 2405 * zones coming right after the local ones are those from 2406 * node N+1 (modulo N) 2407 */ 2408 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 2409 if (!node_online(node)) 2410 continue; 2411 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2412 MAX_NR_ZONES - 1); 2413 } 2414 for (node = 0; node < local_node; node++) { 2415 if (!node_online(node)) 2416 continue; 2417 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2418 MAX_NR_ZONES - 1); 2419 } 2420 2421 zonelist->_zonerefs[j].zone = NULL; 2422 zonelist->_zonerefs[j].zone_idx = 0; 2423} 2424 2425/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ 2426static void build_zonelist_cache(pg_data_t *pgdat) 2427{ 2428 pgdat->node_zonelists[0].zlcache_ptr = NULL; 2429} 2430 2431#endif /* CONFIG_NUMA */ 2432 2433/* return values int ....just for stop_machine() */ 2434static int __build_all_zonelists(void *dummy) 2435{ 2436 int nid; 2437 2438 for_each_online_node(nid) { 2439 pg_data_t *pgdat = NODE_DATA(nid); 2440 2441 build_zonelists(pgdat); 2442 build_zonelist_cache(pgdat); 2443 } 2444 return 0; 2445} 2446 2447void build_all_zonelists(void) 2448{ 2449 set_zonelist_order(); 2450 2451 if (system_state == SYSTEM_BOOTING) { 2452 __build_all_zonelists(NULL); 2453 mminit_verify_zonelist(); 2454 cpuset_init_current_mems_allowed(); 2455 } else { 2456 /* we have to stop all cpus to guarantee there is no user 2457 of zonelist */ 2458 stop_machine(__build_all_zonelists, NULL, NULL); 2459 /* cpuset refresh routine should be here */ 2460 } 2461 vm_total_pages = nr_free_pagecache_pages(); 2462 /* 2463 * Disable grouping by mobility if the number of pages in the 2464 * system is too low to allow the mechanism to work. It would be 2465 * more accurate, but expensive to check per-zone. This check is 2466 * made on memory-hotadd so a system can start with mobility 2467 * disabled and enable it later 2468 */ 2469 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) 2470 page_group_by_mobility_disabled = 1; 2471 else 2472 page_group_by_mobility_disabled = 0; 2473 2474 printk("Built %i zonelists in %s order, mobility grouping %s. " 2475 "Total pages: %ld\n", 2476 num_online_nodes(), 2477 zonelist_order_name[current_zonelist_order], 2478 page_group_by_mobility_disabled ? "off" : "on", 2479 vm_total_pages); 2480#ifdef CONFIG_NUMA 2481 printk("Policy zone: %s\n", zone_names[policy_zone]); 2482#endif 2483} 2484 2485/* 2486 * Helper functions to size the waitqueue hash table. 2487 * Essentially these want to choose hash table sizes sufficiently 2488 * large so that collisions trying to wait on pages are rare. 2489 * But in fact, the number of active page waitqueues on typical 2490 * systems is ridiculously low, less than 200. So this is even 2491 * conservative, even though it seems large. 2492 * 2493 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 2494 * waitqueues, i.e. the size of the waitq table given the number of pages. 2495 */ 2496#define PAGES_PER_WAITQUEUE 256 2497 2498#ifndef CONFIG_MEMORY_HOTPLUG 2499static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2500{ 2501 unsigned long size = 1; 2502 2503 pages /= PAGES_PER_WAITQUEUE; 2504 2505 while (size < pages) 2506 size <<= 1; 2507 2508 /* 2509 * Once we have dozens or even hundreds of threads sleeping 2510 * on IO we've got bigger problems than wait queue collision. 2511 * Limit the size of the wait table to a reasonable size. 2512 */ 2513 size = min(size, 4096UL); 2514 2515 return max(size, 4UL); 2516} 2517#else 2518/* 2519 * A zone's size might be changed by hot-add, so it is not possible to determine 2520 * a suitable size for its wait_table. So we use the maximum size now. 2521 * 2522 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: 2523 * 2524 * i386 (preemption config) : 4096 x 16 = 64Kbyte. 2525 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. 2526 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. 2527 * 2528 * The maximum entries are prepared when a zone's memory is (512K + 256) pages 2529 * or more by the traditional way. (See above). It equals: 2530 * 2531 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. 2532 * ia64(16K page size) : = ( 8G + 4M)byte. 2533 * powerpc (64K page size) : = (32G +16M)byte. 2534 */ 2535static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2536{ 2537 return 4096UL; 2538} 2539#endif 2540 2541/* 2542 * This is an integer logarithm so that shifts can be used later 2543 * to extract the more random high bits from the multiplicative 2544 * hash function before the remainder is taken. 2545 */ 2546static inline unsigned long wait_table_bits(unsigned long size) 2547{ 2548 return ffz(~size); 2549} 2550 2551#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) 2552 2553/* 2554 * Mark a number of pageblocks as MIGRATE_RESERVE. The number 2555 * of blocks reserved is based on zone->pages_min. The memory within the 2556 * reserve will tend to store contiguous free pages. Setting min_free_kbytes 2557 * higher will lead to a bigger reserve which will get freed as contiguous 2558 * blocks as reclaim kicks in 2559 */ 2560static void setup_zone_migrate_reserve(struct zone *zone) 2561{ 2562 unsigned long start_pfn, pfn, end_pfn; 2563 struct page *page; 2564 unsigned long reserve, block_migratetype; 2565 2566 /* Get the start pfn, end pfn and the number of blocks to reserve */ 2567 start_pfn = zone->zone_start_pfn; 2568 end_pfn = start_pfn + zone->spanned_pages; 2569 reserve = roundup(zone->pages_min, pageblock_nr_pages) >> 2570 pageblock_order; 2571 2572 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 2573 if (!pfn_valid(pfn)) 2574 continue; 2575 page = pfn_to_page(pfn); 2576 2577 /* Watch out for overlapping nodes */ 2578 if (page_to_nid(page) != zone_to_nid(zone)) 2579 continue; 2580 2581 /* Blocks with reserved pages will never free, skip them. */ 2582 if (PageReserved(page)) 2583 continue; 2584 2585 block_migratetype = get_pageblock_migratetype(page); 2586 2587 /* If this block is reserved, account for it */ 2588 if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) { 2589 reserve--; 2590 continue; 2591 } 2592 2593 /* Suitable for reserving if this block is movable */ 2594 if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) { 2595 set_pageblock_migratetype(page, MIGRATE_RESERVE); 2596 move_freepages_block(zone, page, MIGRATE_RESERVE); 2597 reserve--; 2598 continue; 2599 } 2600 2601 /* 2602 * If the reserve is met and this is a previous reserved block, 2603 * take it back 2604 */ 2605 if (block_migratetype == MIGRATE_RESERVE) { 2606 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 2607 move_freepages_block(zone, page, MIGRATE_MOVABLE); 2608 } 2609 } 2610} 2611 2612/* 2613 * Initially all pages are reserved - free ones are freed 2614 * up by free_all_bootmem() once the early boot process is 2615 * done. Non-atomic initialization, single-pass. 2616 */ 2617void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 2618 unsigned long start_pfn, enum memmap_context context) 2619{ 2620 struct page *page; 2621 unsigned long end_pfn = start_pfn + size; 2622 unsigned long pfn; 2623 struct zone *z; 2624 2625 if (highest_memmap_pfn < end_pfn - 1) 2626 highest_memmap_pfn = end_pfn - 1; 2627 2628 z = &NODE_DATA(nid)->node_zones[zone]; 2629 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 2630 /* 2631 * There can be holes in boot-time mem_map[]s 2632 * handed to this function. They do not 2633 * exist on hotplugged memory. 2634 */ 2635 if (context == MEMMAP_EARLY) { 2636 if (!early_pfn_valid(pfn)) 2637 continue; 2638 if (!early_pfn_in_nid(pfn, nid)) 2639 continue; 2640 } 2641 page = pfn_to_page(pfn); 2642 set_page_links(page, zone, nid, pfn); 2643 mminit_verify_page_links(page, zone, nid, pfn); 2644 init_page_count(page); 2645 reset_page_mapcount(page); 2646 SetPageReserved(page); 2647 /* 2648 * Mark the block movable so that blocks are reserved for 2649 * movable at startup. This will force kernel allocations 2650 * to reserve their blocks rather than leaking throughout 2651 * the address space during boot when many long-lived 2652 * kernel allocations are made. Later some blocks near 2653 * the start are marked MIGRATE_RESERVE by 2654 * setup_zone_migrate_reserve() 2655 * 2656 * bitmap is created for zone's valid pfn range. but memmap 2657 * can be created for invalid pages (for alignment) 2658 * check here not to call set_pageblock_migratetype() against 2659 * pfn out of zone. 2660 */ 2661 if ((z->zone_start_pfn <= pfn) 2662 && (pfn < z->zone_start_pfn + z->spanned_pages) 2663 && !(pfn & (pageblock_nr_pages - 1))) 2664 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 2665 2666 INIT_LIST_HEAD(&page->lru); 2667#ifdef WANT_PAGE_VIRTUAL 2668 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 2669 if (!is_highmem_idx(zone)) 2670 set_page_address(page, __va(pfn << PAGE_SHIFT)); 2671#endif 2672 } 2673} 2674 2675static void __meminit zone_init_free_lists(struct zone *zone) 2676{ 2677 int order, t; 2678 for_each_migratetype_order(order, t) { 2679 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); 2680 zone->free_area[order].nr_free = 0; 2681 } 2682} 2683 2684#ifndef __HAVE_ARCH_MEMMAP_INIT 2685#define memmap_init(size, nid, zone, start_pfn) \ 2686 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) 2687#endif 2688 2689static int zone_batchsize(struct zone *zone) 2690{ 2691 int batch; 2692 2693 /* 2694 * The per-cpu-pages pools are set to around 1000th of the 2695 * size of the zone. But no more than 1/2 of a meg. 2696 * 2697 * OK, so we don't know how big the cache is. So guess. 2698 */ 2699 batch = zone->present_pages / 1024; 2700 if (batch * PAGE_SIZE > 512 * 1024) 2701 batch = (512 * 1024) / PAGE_SIZE; 2702 batch /= 4; /* We effectively *= 4 below */ 2703 if (batch < 1) 2704 batch = 1; 2705 2706 /* 2707 * Clamp the batch to a 2^n - 1 value. Having a power 2708 * of 2 value was found to be more likely to have 2709 * suboptimal cache aliasing properties in some cases. 2710 * 2711 * For example if 2 tasks are alternately allocating 2712 * batches of pages, one task can end up with a lot 2713 * of pages of one half of the possible page colors 2714 * and the other with pages of the other colors. 2715 */ 2716 batch = (1 << (fls(batch + batch/2)-1)) - 1; 2717 2718 return batch; 2719} 2720 2721static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 2722{ 2723 struct per_cpu_pages *pcp; 2724 2725 memset(p, 0, sizeof(*p)); 2726 2727 pcp = &p->pcp; 2728 pcp->count = 0; 2729 pcp->high = 6 * batch; 2730 pcp->batch = max(1UL, 1 * batch); 2731 INIT_LIST_HEAD(&pcp->list); 2732} 2733 2734/* 2735 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist 2736 * to the value high for the pageset p. 2737 */ 2738 2739static void setup_pagelist_highmark(struct per_cpu_pageset *p, 2740 unsigned long high) 2741{ 2742 struct per_cpu_pages *pcp; 2743 2744 pcp = &p->pcp; 2745 pcp->high = high; 2746 pcp->batch = max(1UL, high/4); 2747 if ((high/4) > (PAGE_SHIFT * 8)) 2748 pcp->batch = PAGE_SHIFT * 8; 2749} 2750 2751 2752#ifdef CONFIG_NUMA 2753/* 2754 * Boot pageset table. One per cpu which is going to be used for all 2755 * zones and all nodes. The parameters will be set in such a way 2756 * that an item put on a list will immediately be handed over to 2757 * the buddy list. This is safe since pageset manipulation is done 2758 * with interrupts disabled. 2759 * 2760 * Some NUMA counter updates may also be caught by the boot pagesets. 2761 * 2762 * The boot_pagesets must be kept even after bootup is complete for 2763 * unused processors and/or zones. They do play a role for bootstrapping 2764 * hotplugged processors. 2765 * 2766 * zoneinfo_show() and maybe other functions do 2767 * not check if the processor is online before following the pageset pointer. 2768 * Other parts of the kernel may not check if the zone is available. 2769 */ 2770static struct per_cpu_pageset boot_pageset[NR_CPUS]; 2771 2772/* 2773 * Dynamically allocate memory for the 2774 * per cpu pageset array in struct zone. 2775 */ 2776static int __cpuinit process_zones(int cpu) 2777{ 2778 struct zone *zone, *dzone; 2779 int node = cpu_to_node(cpu); 2780 2781 node_set_state(node, N_CPU); /* this node has a cpu */ 2782 2783 for_each_zone(zone) { 2784 2785 if (!populated_zone(zone)) 2786 continue; 2787 2788 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset), 2789 GFP_KERNEL, node); 2790 if (!zone_pcp(zone, cpu)) 2791 goto bad; 2792 2793 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone)); 2794 2795 if (percpu_pagelist_fraction) 2796 setup_pagelist_highmark(zone_pcp(zone, cpu), 2797 (zone->present_pages / percpu_pagelist_fraction)); 2798 } 2799 2800 return 0; 2801bad: 2802 for_each_zone(dzone) { 2803 if (!populated_zone(dzone)) 2804 continue; 2805 if (dzone == zone) 2806 break; 2807 kfree(zone_pcp(dzone, cpu)); 2808 zone_pcp(dzone, cpu) = NULL; 2809 } 2810 return -ENOMEM; 2811} 2812 2813static inline void free_zone_pagesets(int cpu) 2814{ 2815 struct zone *zone; 2816 2817 for_each_zone(zone) { 2818 struct per_cpu_pageset *pset = zone_pcp(zone, cpu); 2819 2820 /* Free per_cpu_pageset if it is slab allocated */ 2821 if (pset != &boot_pageset[cpu]) 2822 kfree(pset); 2823 zone_pcp(zone, cpu) = NULL; 2824 } 2825} 2826 2827static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb, 2828 unsigned long action, 2829 void *hcpu) 2830{ 2831 int cpu = (long)hcpu; 2832 int ret = NOTIFY_OK; 2833 2834 switch (action) { 2835 case CPU_UP_PREPARE: 2836 case CPU_UP_PREPARE_FROZEN: 2837 if (process_zones(cpu)) 2838 ret = NOTIFY_BAD; 2839 break; 2840 case CPU_UP_CANCELED: 2841 case CPU_UP_CANCELED_FROZEN: 2842 case CPU_DEAD: 2843 case CPU_DEAD_FROZEN: 2844 free_zone_pagesets(cpu); 2845 break; 2846 default: 2847 break; 2848 } 2849 return ret; 2850} 2851 2852static struct notifier_block __cpuinitdata pageset_notifier = 2853 { &pageset_cpuup_callback, NULL, 0 }; 2854 2855void __init setup_per_cpu_pageset(void) 2856{ 2857 int err; 2858 2859 /* Initialize per_cpu_pageset for cpu 0. 2860 * A cpuup callback will do this for every cpu 2861 * as it comes online 2862 */ 2863 err = process_zones(smp_processor_id()); 2864 BUG_ON(err); 2865 register_cpu_notifier(&pageset_notifier); 2866} 2867 2868#endif 2869 2870static noinline __init_refok 2871int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 2872{ 2873 int i; 2874 struct pglist_data *pgdat = zone->zone_pgdat; 2875 size_t alloc_size; 2876 2877 /* 2878 * The per-page waitqueue mechanism uses hashed waitqueues 2879 * per zone. 2880 */ 2881 zone->wait_table_hash_nr_entries = 2882 wait_table_hash_nr_entries(zone_size_pages); 2883 zone->wait_table_bits = 2884 wait_table_bits(zone->wait_table_hash_nr_entries); 2885 alloc_size = zone->wait_table_hash_nr_entries 2886 * sizeof(wait_queue_head_t); 2887 2888 if (!slab_is_available()) { 2889 zone->wait_table = (wait_queue_head_t *) 2890 alloc_bootmem_node(pgdat, alloc_size); 2891 } else { 2892 /* 2893 * This case means that a zone whose size was 0 gets new memory 2894 * via memory hot-add. 2895 * But it may be the case that a new node was hot-added. In 2896 * this case vmalloc() will not be able to use this new node's 2897 * memory - this wait_table must be initialized to use this new 2898 * node itself as well. 2899 * To use this new node's memory, further consideration will be 2900 * necessary. 2901 */ 2902 zone->wait_table = vmalloc(alloc_size); 2903 } 2904 if (!zone->wait_table) 2905 return -ENOMEM; 2906 2907 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i) 2908 init_waitqueue_head(zone->wait_table + i); 2909 2910 return 0; 2911} 2912 2913static __meminit void zone_pcp_init(struct zone *zone) 2914{ 2915 int cpu; 2916 unsigned long batch = zone_batchsize(zone); 2917 2918 for (cpu = 0; cpu < NR_CPUS; cpu++) { 2919#ifdef CONFIG_NUMA 2920 /* Early boot. Slab allocator not functional yet */ 2921 zone_pcp(zone, cpu) = &boot_pageset[cpu]; 2922 setup_pageset(&boot_pageset[cpu],0); 2923#else 2924 setup_pageset(zone_pcp(zone,cpu), batch); 2925#endif 2926 } 2927 if (zone->present_pages) 2928 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", 2929 zone->name, zone->present_pages, batch); 2930} 2931 2932__meminit int init_currently_empty_zone(struct zone *zone, 2933 unsigned long zone_start_pfn, 2934 unsigned long size, 2935 enum memmap_context context) 2936{ 2937 struct pglist_data *pgdat = zone->zone_pgdat; 2938 int ret; 2939 ret = zone_wait_table_init(zone, size); 2940 if (ret) 2941 return ret; 2942 pgdat->nr_zones = zone_idx(zone) + 1; 2943 2944 zone->zone_start_pfn = zone_start_pfn; 2945 2946 mminit_dprintk(MMINIT_TRACE, "memmap_init", 2947 "Initialising map node %d zone %lu pfns %lu -> %lu\n", 2948 pgdat->node_id, 2949 (unsigned long)zone_idx(zone), 2950 zone_start_pfn, (zone_start_pfn + size)); 2951 2952 zone_init_free_lists(zone); 2953 2954 return 0; 2955} 2956 2957#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 2958/* 2959 * Basic iterator support. Return the first range of PFNs for a node 2960 * Note: nid == MAX_NUMNODES returns first region regardless of node 2961 */ 2962static int __meminit first_active_region_index_in_nid(int nid) 2963{ 2964 int i; 2965 2966 for (i = 0; i < nr_nodemap_entries; i++) 2967 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid) 2968 return i; 2969 2970 return -1; 2971} 2972 2973/* 2974 * Basic iterator support. Return the next active range of PFNs for a node 2975 * Note: nid == MAX_NUMNODES returns next region regardless of node 2976 */ 2977static int __meminit next_active_region_index_in_nid(int index, int nid) 2978{ 2979 for (index = index + 1; index < nr_nodemap_entries; index++) 2980 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid) 2981 return index; 2982 2983 return -1; 2984} 2985 2986#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID 2987/* 2988 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. 2989 * Architectures may implement their own version but if add_active_range() 2990 * was used and there are no special requirements, this is a convenient 2991 * alternative 2992 */ 2993int __meminit early_pfn_to_nid(unsigned long pfn) 2994{ 2995 int i; 2996 2997 for (i = 0; i < nr_nodemap_entries; i++) { 2998 unsigned long start_pfn = early_node_map[i].start_pfn; 2999 unsigned long end_pfn = early_node_map[i].end_pfn; 3000 3001 if (start_pfn <= pfn && pfn < end_pfn) 3002 return early_node_map[i].nid; 3003 } 3004 3005 return 0; 3006} 3007#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ 3008 3009/* Basic iterator support to walk early_node_map[] */ 3010#define for_each_active_range_index_in_nid(i, nid) \ 3011 for (i = first_active_region_index_in_nid(nid); i != -1; \ 3012 i = next_active_region_index_in_nid(i, nid)) 3013 3014/** 3015 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range 3016 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. 3017 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node 3018 * 3019 * If an architecture guarantees that all ranges registered with 3020 * add_active_ranges() contain no holes and may be freed, this 3021 * this function may be used instead of calling free_bootmem() manually. 3022 */ 3023void __init free_bootmem_with_active_regions(int nid, 3024 unsigned long max_low_pfn) 3025{ 3026 int i; 3027 3028 for_each_active_range_index_in_nid(i, nid) { 3029 unsigned long size_pages = 0; 3030 unsigned long end_pfn = early_node_map[i].end_pfn; 3031 3032 if (early_node_map[i].start_pfn >= max_low_pfn) 3033 continue; 3034 3035 if (end_pfn > max_low_pfn) 3036 end_pfn = max_low_pfn; 3037 3038 size_pages = end_pfn - early_node_map[i].start_pfn; 3039 free_bootmem_node(NODE_DATA(early_node_map[i].nid), 3040 PFN_PHYS(early_node_map[i].start_pfn), 3041 size_pages << PAGE_SHIFT); 3042 } 3043} 3044 3045void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data) 3046{ 3047 int i; 3048 int ret; 3049 3050 for_each_active_range_index_in_nid(i, nid) { 3051 ret = work_fn(early_node_map[i].start_pfn, 3052 early_node_map[i].end_pfn, data); 3053 if (ret) 3054 break; 3055 } 3056} 3057/** 3058 * sparse_memory_present_with_active_regions - Call memory_present for each active range 3059 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. 3060 * 3061 * If an architecture guarantees that all ranges registered with 3062 * add_active_ranges() contain no holes and may be freed, this 3063 * function may be used instead of calling memory_present() manually. 3064 */ 3065void __init sparse_memory_present_with_active_regions(int nid) 3066{ 3067 int i; 3068 3069 for_each_active_range_index_in_nid(i, nid) 3070 memory_present(early_node_map[i].nid, 3071 early_node_map[i].start_pfn, 3072 early_node_map[i].end_pfn); 3073} 3074 3075/** 3076 * push_node_boundaries - Push node boundaries to at least the requested boundary 3077 * @nid: The nid of the node to push the boundary for 3078 * @start_pfn: The start pfn of the node 3079 * @end_pfn: The end pfn of the node 3080 * 3081 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd 3082 * time. Specifically, on x86_64, SRAT will report ranges that can potentially 3083 * be hotplugged even though no physical memory exists. This function allows 3084 * an arch to push out the node boundaries so mem_map is allocated that can 3085 * be used later. 3086 */ 3087#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE 3088void __init push_node_boundaries(unsigned int nid, 3089 unsigned long start_pfn, unsigned long end_pfn) 3090{ 3091 mminit_dprintk(MMINIT_TRACE, "zoneboundary", 3092 "Entering push_node_boundaries(%u, %lu, %lu)\n", 3093 nid, start_pfn, end_pfn); 3094 3095 /* Initialise the boundary for this node if necessary */ 3096 if (node_boundary_end_pfn[nid] == 0) 3097 node_boundary_start_pfn[nid] = -1UL; 3098 3099 /* Update the boundaries */ 3100 if (node_boundary_start_pfn[nid] > start_pfn) 3101 node_boundary_start_pfn[nid] = start_pfn; 3102 if (node_boundary_end_pfn[nid] < end_pfn) 3103 node_boundary_end_pfn[nid] = end_pfn; 3104} 3105 3106/* If necessary, push the node boundary out for reserve hotadd */ 3107static void __meminit account_node_boundary(unsigned int nid, 3108 unsigned long *start_pfn, unsigned long *end_pfn) 3109{ 3110 mminit_dprintk(MMINIT_TRACE, "zoneboundary", 3111 "Entering account_node_boundary(%u, %lu, %lu)\n", 3112 nid, *start_pfn, *end_pfn); 3113 3114 /* Return if boundary information has not been provided */ 3115 if (node_boundary_end_pfn[nid] == 0) 3116 return; 3117 3118 /* Check the boundaries and update if necessary */ 3119 if (node_boundary_start_pfn[nid] < *start_pfn) 3120 *start_pfn = node_boundary_start_pfn[nid]; 3121 if (node_boundary_end_pfn[nid] > *end_pfn) 3122 *end_pfn = node_boundary_end_pfn[nid]; 3123} 3124#else 3125void __init push_node_boundaries(unsigned int nid, 3126 unsigned long start_pfn, unsigned long end_pfn) {} 3127 3128static void __meminit account_node_boundary(unsigned int nid, 3129 unsigned long *start_pfn, unsigned long *end_pfn) {} 3130#endif 3131 3132 3133/** 3134 * get_pfn_range_for_nid - Return the start and end page frames for a node 3135 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. 3136 * @start_pfn: Passed by reference. On return, it will have the node start_pfn. 3137 * @end_pfn: Passed by reference. On return, it will have the node end_pfn. 3138 * 3139 * It returns the start and end page frame of a node based on information 3140 * provided by an arch calling add_active_range(). If called for a node 3141 * with no available memory, a warning is printed and the start and end 3142 * PFNs will be 0. 3143 */ 3144void __meminit get_pfn_range_for_nid(unsigned int nid, 3145 unsigned long *start_pfn, unsigned long *end_pfn) 3146{ 3147 int i; 3148 *start_pfn = -1UL; 3149 *end_pfn = 0; 3150 3151 for_each_active_range_index_in_nid(i, nid) { 3152 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn); 3153 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn); 3154 } 3155 3156 if (*start_pfn == -1UL) 3157 *start_pfn = 0; 3158 3159 /* Push the node boundaries out if requested */ 3160 account_node_boundary(nid, start_pfn, end_pfn); 3161} 3162 3163/* 3164 * This finds a zone that can be used for ZONE_MOVABLE pages. The 3165 * assumption is made that zones within a node are ordered in monotonic 3166 * increasing memory addresses so that the "highest" populated zone is used 3167 */ 3168static void __init find_usable_zone_for_movable(void) 3169{ 3170 int zone_index; 3171 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { 3172 if (zone_index == ZONE_MOVABLE) 3173 continue; 3174 3175 if (arch_zone_highest_possible_pfn[zone_index] > 3176 arch_zone_lowest_possible_pfn[zone_index]) 3177 break; 3178 } 3179 3180 VM_BUG_ON(zone_index == -1); 3181 movable_zone = zone_index; 3182} 3183 3184/* 3185 * The zone ranges provided by the architecture do not include ZONE_MOVABLE 3186 * because it is sized independant of architecture. Unlike the other zones, 3187 * the starting point for ZONE_MOVABLE is not fixed. It may be different 3188 * in each node depending on the size of each node and how evenly kernelcore 3189 * is distributed. This helper function adjusts the zone ranges 3190 * provided by the architecture for a given node by using the end of the 3191 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that 3192 * zones within a node are in order of monotonic increases memory addresses 3193 */ 3194static void __meminit adjust_zone_range_for_zone_movable(int nid, 3195 unsigned long zone_type, 3196 unsigned long node_start_pfn, 3197 unsigned long node_end_pfn, 3198 unsigned long *zone_start_pfn, 3199 unsigned long *zone_end_pfn) 3200{ 3201 /* Only adjust if ZONE_MOVABLE is on this node */ 3202 if (zone_movable_pfn[nid]) { 3203 /* Size ZONE_MOVABLE */ 3204 if (zone_type == ZONE_MOVABLE) { 3205 *zone_start_pfn = zone_movable_pfn[nid]; 3206 *zone_end_pfn = min(node_end_pfn, 3207 arch_zone_highest_possible_pfn[movable_zone]); 3208 3209 /* Adjust for ZONE_MOVABLE starting within this range */ 3210 } else if (*zone_start_pfn < zone_movable_pfn[nid] && 3211 *zone_end_pfn > zone_movable_pfn[nid]) { 3212 *zone_end_pfn = zone_movable_pfn[nid]; 3213 3214 /* Check if this whole range is within ZONE_MOVABLE */ 3215 } else if (*zone_start_pfn >= zone_movable_pfn[nid]) 3216 *zone_start_pfn = *zone_end_pfn; 3217 } 3218} 3219 3220/* 3221 * Return the number of pages a zone spans in a node, including holes 3222 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() 3223 */ 3224static unsigned long __meminit zone_spanned_pages_in_node(int nid, 3225 unsigned long zone_type, 3226 unsigned long *ignored) 3227{ 3228 unsigned long node_start_pfn, node_end_pfn; 3229 unsigned long zone_start_pfn, zone_end_pfn; 3230 3231 /* Get the start and end of the node and zone */ 3232 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3233 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; 3234 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; 3235 adjust_zone_range_for_zone_movable(nid, zone_type, 3236 node_start_pfn, node_end_pfn, 3237 &zone_start_pfn, &zone_end_pfn); 3238 3239 /* Check that this node has pages within the zone's required range */ 3240 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) 3241 return 0; 3242 3243 /* Move the zone boundaries inside the node if necessary */ 3244 zone_end_pfn = min(zone_end_pfn, node_end_pfn); 3245 zone_start_pfn = max(zone_start_pfn, node_start_pfn); 3246 3247 /* Return the spanned pages */ 3248 return zone_end_pfn - zone_start_pfn; 3249} 3250 3251/* 3252 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, 3253 * then all holes in the requested range will be accounted for. 3254 */ 3255static unsigned long __meminit __absent_pages_in_range(int nid, 3256 unsigned long range_start_pfn, 3257 unsigned long range_end_pfn) 3258{ 3259 int i = 0; 3260 unsigned long prev_end_pfn = 0, hole_pages = 0; 3261 unsigned long start_pfn; 3262 3263 /* Find the end_pfn of the first active range of pfns in the node */ 3264 i = first_active_region_index_in_nid(nid); 3265 if (i == -1) 3266 return 0; 3267 3268 prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 3269 3270 /* Account for ranges before physical memory on this node */ 3271 if (early_node_map[i].start_pfn > range_start_pfn) 3272 hole_pages = prev_end_pfn - range_start_pfn; 3273 3274 /* Find all holes for the zone within the node */ 3275 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) { 3276 3277 /* No need to continue if prev_end_pfn is outside the zone */ 3278 if (prev_end_pfn >= range_end_pfn) 3279 break; 3280 3281 /* Make sure the end of the zone is not within the hole */ 3282 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 3283 prev_end_pfn = max(prev_end_pfn, range_start_pfn); 3284 3285 /* Update the hole size cound and move on */ 3286 if (start_pfn > range_start_pfn) { 3287 BUG_ON(prev_end_pfn > start_pfn); 3288 hole_pages += start_pfn - prev_end_pfn; 3289 } 3290 prev_end_pfn = early_node_map[i].end_pfn; 3291 } 3292 3293 /* Account for ranges past physical memory on this node */ 3294 if (range_end_pfn > prev_end_pfn) 3295 hole_pages += range_end_pfn - 3296 max(range_start_pfn, prev_end_pfn); 3297 3298 return hole_pages; 3299} 3300 3301/** 3302 * absent_pages_in_range - Return number of page frames in holes within a range 3303 * @start_pfn: The start PFN to start searching for holes 3304 * @end_pfn: The end PFN to stop searching for holes 3305 * 3306 * It returns the number of pages frames in memory holes within a range. 3307 */ 3308unsigned long __init absent_pages_in_range(unsigned long start_pfn, 3309 unsigned long end_pfn) 3310{ 3311 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); 3312} 3313 3314/* Return the number of page frames in holes in a zone on a node */ 3315static unsigned long __meminit zone_absent_pages_in_node(int nid, 3316 unsigned long zone_type, 3317 unsigned long *ignored) 3318{ 3319 unsigned long node_start_pfn, node_end_pfn; 3320 unsigned long zone_start_pfn, zone_end_pfn; 3321 3322 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3323 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type], 3324 node_start_pfn); 3325 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type], 3326 node_end_pfn); 3327 3328 adjust_zone_range_for_zone_movable(nid, zone_type, 3329 node_start_pfn, node_end_pfn, 3330 &zone_start_pfn, &zone_end_pfn); 3331 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); 3332} 3333 3334#else 3335static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, 3336 unsigned long zone_type, 3337 unsigned long *zones_size) 3338{ 3339 return zones_size[zone_type]; 3340} 3341 3342static inline unsigned long __meminit zone_absent_pages_in_node(int nid, 3343 unsigned long zone_type, 3344 unsigned long *zholes_size) 3345{ 3346 if (!zholes_size) 3347 return 0; 3348 3349 return zholes_size[zone_type]; 3350} 3351 3352#endif 3353 3354static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, 3355 unsigned long *zones_size, unsigned long *zholes_size) 3356{ 3357 unsigned long realtotalpages, totalpages = 0; 3358 enum zone_type i; 3359 3360 for (i = 0; i < MAX_NR_ZONES; i++) 3361 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i, 3362 zones_size); 3363 pgdat->node_spanned_pages = totalpages; 3364 3365 realtotalpages = totalpages; 3366 for (i = 0; i < MAX_NR_ZONES; i++) 3367 realtotalpages -= 3368 zone_absent_pages_in_node(pgdat->node_id, i, 3369 zholes_size); 3370 pgdat->node_present_pages = realtotalpages; 3371 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, 3372 realtotalpages); 3373} 3374 3375#ifndef CONFIG_SPARSEMEM 3376/* 3377 * Calculate the size of the zone->blockflags rounded to an unsigned long 3378 * Start by making sure zonesize is a multiple of pageblock_order by rounding 3379 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally 3380 * round what is now in bits to nearest long in bits, then return it in 3381 * bytes. 3382 */ 3383static unsigned long __init usemap_size(unsigned long zonesize) 3384{ 3385 unsigned long usemapsize; 3386 3387 usemapsize = roundup(zonesize, pageblock_nr_pages); 3388 usemapsize = usemapsize >> pageblock_order; 3389 usemapsize *= NR_PAGEBLOCK_BITS; 3390 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); 3391 3392 return usemapsize / 8; 3393} 3394 3395static void __init setup_usemap(struct pglist_data *pgdat, 3396 struct zone *zone, unsigned long zonesize) 3397{ 3398 unsigned long usemapsize = usemap_size(zonesize); 3399 zone->pageblock_flags = NULL; 3400 if (usemapsize) 3401 zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize); 3402} 3403#else 3404static void inline setup_usemap(struct pglist_data *pgdat, 3405 struct zone *zone, unsigned long zonesize) {} 3406#endif /* CONFIG_SPARSEMEM */ 3407 3408#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 3409 3410/* Return a sensible default order for the pageblock size. */ 3411static inline int pageblock_default_order(void) 3412{ 3413 if (HPAGE_SHIFT > PAGE_SHIFT) 3414 return HUGETLB_PAGE_ORDER; 3415 3416 return MAX_ORDER-1; 3417} 3418 3419/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ 3420static inline void __init set_pageblock_order(unsigned int order) 3421{ 3422 /* Check that pageblock_nr_pages has not already been setup */ 3423 if (pageblock_order) 3424 return; 3425 3426 /* 3427 * Assume the largest contiguous order of interest is a huge page. 3428 * This value may be variable depending on boot parameters on IA64 3429 */ 3430 pageblock_order = order; 3431} 3432#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 3433 3434/* 3435 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() 3436 * and pageblock_default_order() are unused as pageblock_order is set 3437 * at compile-time. See include/linux/pageblock-flags.h for the values of 3438 * pageblock_order based on the kernel config 3439 */ 3440static inline int pageblock_default_order(unsigned int order) 3441{ 3442 return MAX_ORDER-1; 3443} 3444#define set_pageblock_order(x) do {} while (0) 3445 3446#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 3447 3448/* 3449 * Set up the zone data structures: 3450 * - mark all pages reserved 3451 * - mark all memory queues empty 3452 * - clear the memory bitmaps 3453 */ 3454static void __paginginit free_area_init_core(struct pglist_data *pgdat, 3455 unsigned long *zones_size, unsigned long *zholes_size) 3456{ 3457 enum zone_type j; 3458 int nid = pgdat->node_id; 3459 unsigned long zone_start_pfn = pgdat->node_start_pfn; 3460 int ret; 3461 3462 pgdat_resize_init(pgdat); 3463 pgdat->nr_zones = 0; 3464 init_waitqueue_head(&pgdat->kswapd_wait); 3465 pgdat->kswapd_max_order = 0; 3466 pgdat_page_cgroup_init(pgdat); 3467 3468 for (j = 0; j < MAX_NR_ZONES; j++) { 3469 struct zone *zone = pgdat->node_zones + j; 3470 unsigned long size, realsize, memmap_pages; 3471 enum lru_list l; 3472 3473 size = zone_spanned_pages_in_node(nid, j, zones_size); 3474 realsize = size - zone_absent_pages_in_node(nid, j, 3475 zholes_size); 3476 3477 /* 3478 * Adjust realsize so that it accounts for how much memory 3479 * is used by this zone for memmap. This affects the watermark 3480 * and per-cpu initialisations 3481 */ 3482 memmap_pages = 3483 PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT; 3484 if (realsize >= memmap_pages) { 3485 realsize -= memmap_pages; 3486 if (memmap_pages) 3487 printk(KERN_DEBUG 3488 " %s zone: %lu pages used for memmap\n", 3489 zone_names[j], memmap_pages); 3490 } else 3491 printk(KERN_WARNING 3492 " %s zone: %lu pages exceeds realsize %lu\n", 3493 zone_names[j], memmap_pages, realsize); 3494 3495 /* Account for reserved pages */ 3496 if (j == 0 && realsize > dma_reserve) { 3497 realsize -= dma_reserve; 3498 printk(KERN_DEBUG " %s zone: %lu pages reserved\n", 3499 zone_names[0], dma_reserve); 3500 } 3501 3502 if (!is_highmem_idx(j)) 3503 nr_kernel_pages += realsize; 3504 nr_all_pages += realsize; 3505 3506 zone->spanned_pages = size; 3507 zone->present_pages = realsize; 3508#ifdef CONFIG_NUMA 3509 zone->node = nid; 3510 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio) 3511 / 100; 3512 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100; 3513#endif 3514 zone->name = zone_names[j]; 3515 spin_lock_init(&zone->lock); 3516 spin_lock_init(&zone->lru_lock); 3517 zone_seqlock_init(zone); 3518 zone->zone_pgdat = pgdat; 3519 3520 zone->prev_priority = DEF_PRIORITY; 3521 3522 zone_pcp_init(zone); 3523 for_each_lru(l) { 3524 INIT_LIST_HEAD(&zone->lru[l].list); 3525 zone->lru[l].nr_scan = 0; 3526 } 3527 zone->recent_rotated[0] = 0; 3528 zone->recent_rotated[1] = 0; 3529 zone->recent_scanned[0] = 0; 3530 zone->recent_scanned[1] = 0; 3531 zap_zone_vm_stats(zone); 3532 zone->flags = 0; 3533 if (!size) 3534 continue; 3535 3536 set_pageblock_order(pageblock_default_order()); 3537 setup_usemap(pgdat, zone, size); 3538 ret = init_currently_empty_zone(zone, zone_start_pfn, 3539 size, MEMMAP_EARLY); 3540 BUG_ON(ret); 3541 memmap_init(size, nid, j, zone_start_pfn); 3542 zone_start_pfn += size; 3543 } 3544} 3545 3546static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat) 3547{ 3548 /* Skip empty nodes */ 3549 if (!pgdat->node_spanned_pages) 3550 return; 3551 3552#ifdef CONFIG_FLAT_NODE_MEM_MAP 3553 /* ia64 gets its own node_mem_map, before this, without bootmem */ 3554 if (!pgdat->node_mem_map) { 3555 unsigned long size, start, end; 3556 struct page *map; 3557 3558 /* 3559 * The zone's endpoints aren't required to be MAX_ORDER 3560 * aligned but the node_mem_map endpoints must be in order 3561 * for the buddy allocator to function correctly. 3562 */ 3563 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); 3564 end = pgdat->node_start_pfn + pgdat->node_spanned_pages; 3565 end = ALIGN(end, MAX_ORDER_NR_PAGES); 3566 size = (end - start) * sizeof(struct page); 3567 map = alloc_remap(pgdat->node_id, size); 3568 if (!map) 3569 map = alloc_bootmem_node(pgdat, size); 3570 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); 3571 } 3572#ifndef CONFIG_NEED_MULTIPLE_NODES 3573 /* 3574 * With no DISCONTIG, the global mem_map is just set as node 0's 3575 */ 3576 if (pgdat == NODE_DATA(0)) { 3577 mem_map = NODE_DATA(0)->node_mem_map; 3578#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3579 if (page_to_pfn(mem_map) != pgdat->node_start_pfn) 3580 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET); 3581#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 3582 } 3583#endif 3584#endif /* CONFIG_FLAT_NODE_MEM_MAP */ 3585} 3586 3587void __paginginit free_area_init_node(int nid, unsigned long *zones_size, 3588 unsigned long node_start_pfn, unsigned long *zholes_size) 3589{ 3590 pg_data_t *pgdat = NODE_DATA(nid); 3591 3592 pgdat->node_id = nid; 3593 pgdat->node_start_pfn = node_start_pfn; 3594 calculate_node_totalpages(pgdat, zones_size, zholes_size); 3595 3596 alloc_node_mem_map(pgdat); 3597#ifdef CONFIG_FLAT_NODE_MEM_MAP 3598 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n", 3599 nid, (unsigned long)pgdat, 3600 (unsigned long)pgdat->node_mem_map); 3601#endif 3602 3603 free_area_init_core(pgdat, zones_size, zholes_size); 3604} 3605 3606#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3607 3608#if MAX_NUMNODES > 1 3609/* 3610 * Figure out the number of possible node ids. 3611 */ 3612static void __init setup_nr_node_ids(void) 3613{ 3614 unsigned int node; 3615 unsigned int highest = 0; 3616 3617 for_each_node_mask(node, node_possible_map) 3618 highest = node; 3619 nr_node_ids = highest + 1; 3620} 3621#else 3622static inline void setup_nr_node_ids(void) 3623{ 3624} 3625#endif 3626 3627/** 3628 * add_active_range - Register a range of PFNs backed by physical memory 3629 * @nid: The node ID the range resides on 3630 * @start_pfn: The start PFN of the available physical memory 3631 * @end_pfn: The end PFN of the available physical memory 3632 * 3633 * These ranges are stored in an early_node_map[] and later used by 3634 * free_area_init_nodes() to calculate zone sizes and holes. If the 3635 * range spans a memory hole, it is up to the architecture to ensure 3636 * the memory is not freed by the bootmem allocator. If possible 3637 * the range being registered will be merged with existing ranges. 3638 */ 3639void __init add_active_range(unsigned int nid, unsigned long start_pfn, 3640 unsigned long end_pfn) 3641{ 3642 int i; 3643 3644 mminit_dprintk(MMINIT_TRACE, "memory_register", 3645 "Entering add_active_range(%d, %#lx, %#lx) " 3646 "%d entries of %d used\n", 3647 nid, start_pfn, end_pfn, 3648 nr_nodemap_entries, MAX_ACTIVE_REGIONS); 3649 3650 mminit_validate_memmodel_limits(&start_pfn, &end_pfn); 3651 3652 /* Merge with existing active regions if possible */ 3653 for (i = 0; i < nr_nodemap_entries; i++) { 3654 if (early_node_map[i].nid != nid) 3655 continue; 3656 3657 /* Skip if an existing region covers this new one */ 3658 if (start_pfn >= early_node_map[i].start_pfn && 3659 end_pfn <= early_node_map[i].end_pfn) 3660 return; 3661 3662 /* Merge forward if suitable */ 3663 if (start_pfn <= early_node_map[i].end_pfn && 3664 end_pfn > early_node_map[i].end_pfn) { 3665 early_node_map[i].end_pfn = end_pfn; 3666 return; 3667 } 3668 3669 /* Merge backward if suitable */ 3670 if (start_pfn < early_node_map[i].end_pfn && 3671 end_pfn >= early_node_map[i].start_pfn) { 3672 early_node_map[i].start_pfn = start_pfn; 3673 return; 3674 } 3675 } 3676 3677 /* Check that early_node_map is large enough */ 3678 if (i >= MAX_ACTIVE_REGIONS) { 3679 printk(KERN_CRIT "More than %d memory regions, truncating\n", 3680 MAX_ACTIVE_REGIONS); 3681 return; 3682 } 3683 3684 early_node_map[i].nid = nid; 3685 early_node_map[i].start_pfn = start_pfn; 3686 early_node_map[i].end_pfn = end_pfn; 3687 nr_nodemap_entries = i + 1; 3688} 3689 3690/** 3691 * remove_active_range - Shrink an existing registered range of PFNs 3692 * @nid: The node id the range is on that should be shrunk 3693 * @start_pfn: The new PFN of the range 3694 * @end_pfn: The new PFN of the range 3695 * 3696 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node. 3697 * The map is kept near the end physical page range that has already been 3698 * registered. This function allows an arch to shrink an existing registered 3699 * range. 3700 */ 3701void __init remove_active_range(unsigned int nid, unsigned long start_pfn, 3702 unsigned long end_pfn) 3703{ 3704 int i, j; 3705 int removed = 0; 3706 3707 printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n", 3708 nid, start_pfn, end_pfn); 3709 3710 /* Find the old active region end and shrink */ 3711 for_each_active_range_index_in_nid(i, nid) { 3712 if (early_node_map[i].start_pfn >= start_pfn && 3713 early_node_map[i].end_pfn <= end_pfn) { 3714 /* clear it */ 3715 early_node_map[i].start_pfn = 0; 3716 early_node_map[i].end_pfn = 0; 3717 removed = 1; 3718 continue; 3719 } 3720 if (early_node_map[i].start_pfn < start_pfn && 3721 early_node_map[i].end_pfn > start_pfn) { 3722 unsigned long temp_end_pfn = early_node_map[i].end_pfn; 3723 early_node_map[i].end_pfn = start_pfn; 3724 if (temp_end_pfn > end_pfn) 3725 add_active_range(nid, end_pfn, temp_end_pfn); 3726 continue; 3727 } 3728 if (early_node_map[i].start_pfn >= start_pfn && 3729 early_node_map[i].end_pfn > end_pfn && 3730 early_node_map[i].start_pfn < end_pfn) { 3731 early_node_map[i].start_pfn = end_pfn; 3732 continue; 3733 } 3734 } 3735 3736 if (!removed) 3737 return; 3738 3739 /* remove the blank ones */ 3740 for (i = nr_nodemap_entries - 1; i > 0; i--) { 3741 if (early_node_map[i].nid != nid) 3742 continue; 3743 if (early_node_map[i].end_pfn) 3744 continue; 3745 /* we found it, get rid of it */ 3746 for (j = i; j < nr_nodemap_entries - 1; j++) 3747 memcpy(&early_node_map[j], &early_node_map[j+1], 3748 sizeof(early_node_map[j])); 3749 j = nr_nodemap_entries - 1; 3750 memset(&early_node_map[j], 0, sizeof(early_node_map[j])); 3751 nr_nodemap_entries--; 3752 } 3753} 3754 3755/** 3756 * remove_all_active_ranges - Remove all currently registered regions 3757 * 3758 * During discovery, it may be found that a table like SRAT is invalid 3759 * and an alternative discovery method must be used. This function removes 3760 * all currently registered regions. 3761 */ 3762void __init remove_all_active_ranges(void) 3763{ 3764 memset(early_node_map, 0, sizeof(early_node_map)); 3765 nr_nodemap_entries = 0; 3766#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE 3767 memset(node_boundary_start_pfn, 0, sizeof(node_boundary_start_pfn)); 3768 memset(node_boundary_end_pfn, 0, sizeof(node_boundary_end_pfn)); 3769#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */ 3770} 3771 3772/* Compare two active node_active_regions */ 3773static int __init cmp_node_active_region(const void *a, const void *b) 3774{ 3775 struct node_active_region *arange = (struct node_active_region *)a; 3776 struct node_active_region *brange = (struct node_active_region *)b; 3777 3778 /* Done this way to avoid overflows */ 3779 if (arange->start_pfn > brange->start_pfn) 3780 return 1; 3781 if (arange->start_pfn < brange->start_pfn) 3782 return -1; 3783 3784 return 0; 3785} 3786 3787/* sort the node_map by start_pfn */ 3788static void __init sort_node_map(void) 3789{ 3790 sort(early_node_map, (size_t)nr_nodemap_entries, 3791 sizeof(struct node_active_region), 3792 cmp_node_active_region, NULL); 3793} 3794 3795/* Find the lowest pfn for a node */ 3796static unsigned long __init find_min_pfn_for_node(int nid) 3797{ 3798 int i; 3799 unsigned long min_pfn = ULONG_MAX; 3800 3801 /* Assuming a sorted map, the first range found has the starting pfn */ 3802 for_each_active_range_index_in_nid(i, nid) 3803 min_pfn = min(min_pfn, early_node_map[i].start_pfn); 3804 3805 if (min_pfn == ULONG_MAX) { 3806 printk(KERN_WARNING 3807 "Could not find start_pfn for node %d\n", nid); 3808 return 0; 3809 } 3810 3811 return min_pfn; 3812} 3813 3814/** 3815 * find_min_pfn_with_active_regions - Find the minimum PFN registered 3816 * 3817 * It returns the minimum PFN based on information provided via 3818 * add_active_range(). 3819 */ 3820unsigned long __init find_min_pfn_with_active_regions(void) 3821{ 3822 return find_min_pfn_for_node(MAX_NUMNODES); 3823} 3824 3825/* 3826 * early_calculate_totalpages() 3827 * Sum pages in active regions for movable zone. 3828 * Populate N_HIGH_MEMORY for calculating usable_nodes. 3829 */ 3830static unsigned long __init early_calculate_totalpages(void) 3831{ 3832 int i; 3833 unsigned long totalpages = 0; 3834 3835 for (i = 0; i < nr_nodemap_entries; i++) { 3836 unsigned long pages = early_node_map[i].end_pfn - 3837 early_node_map[i].start_pfn; 3838 totalpages += pages; 3839 if (pages) 3840 node_set_state(early_node_map[i].nid, N_HIGH_MEMORY); 3841 } 3842 return totalpages; 3843} 3844 3845/* 3846 * Find the PFN the Movable zone begins in each node. Kernel memory 3847 * is spread evenly between nodes as long as the nodes have enough 3848 * memory. When they don't, some nodes will have more kernelcore than 3849 * others 3850 */ 3851static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn) 3852{ 3853 int i, nid; 3854 unsigned long usable_startpfn; 3855 unsigned long kernelcore_node, kernelcore_remaining; 3856 unsigned long totalpages = early_calculate_totalpages(); 3857 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]); 3858 3859 /* 3860 * If movablecore was specified, calculate what size of 3861 * kernelcore that corresponds so that memory usable for 3862 * any allocation type is evenly spread. If both kernelcore 3863 * and movablecore are specified, then the value of kernelcore 3864 * will be used for required_kernelcore if it's greater than 3865 * what movablecore would have allowed. 3866 */ 3867 if (required_movablecore) { 3868 unsigned long corepages; 3869 3870 /* 3871 * Round-up so that ZONE_MOVABLE is at least as large as what 3872 * was requested by the user 3873 */ 3874 required_movablecore = 3875 roundup(required_movablecore, MAX_ORDER_NR_PAGES); 3876 corepages = totalpages - required_movablecore; 3877 3878 required_kernelcore = max(required_kernelcore, corepages); 3879 } 3880 3881 /* If kernelcore was not specified, there is no ZONE_MOVABLE */ 3882 if (!required_kernelcore) 3883 return; 3884 3885 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ 3886 find_usable_zone_for_movable(); 3887 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; 3888 3889restart: 3890 /* Spread kernelcore memory as evenly as possible throughout nodes */ 3891 kernelcore_node = required_kernelcore / usable_nodes; 3892 for_each_node_state(nid, N_HIGH_MEMORY) { 3893 /* 3894 * Recalculate kernelcore_node if the division per node 3895 * now exceeds what is necessary to satisfy the requested 3896 * amount of memory for the kernel 3897 */ 3898 if (required_kernelcore < kernelcore_node) 3899 kernelcore_node = required_kernelcore / usable_nodes; 3900 3901 /* 3902 * As the map is walked, we track how much memory is usable 3903 * by the kernel using kernelcore_remaining. When it is 3904 * 0, the rest of the node is usable by ZONE_MOVABLE 3905 */ 3906 kernelcore_remaining = kernelcore_node; 3907 3908 /* Go through each range of PFNs within this node */ 3909 for_each_active_range_index_in_nid(i, nid) { 3910 unsigned long start_pfn, end_pfn; 3911 unsigned long size_pages; 3912 3913 start_pfn = max(early_node_map[i].start_pfn, 3914 zone_movable_pfn[nid]); 3915 end_pfn = early_node_map[i].end_pfn; 3916 if (start_pfn >= end_pfn) 3917 continue; 3918 3919 /* Account for what is only usable for kernelcore */ 3920 if (start_pfn < usable_startpfn) { 3921 unsigned long kernel_pages; 3922 kernel_pages = min(end_pfn, usable_startpfn) 3923 - start_pfn; 3924 3925 kernelcore_remaining -= min(kernel_pages, 3926 kernelcore_remaining); 3927 required_kernelcore -= min(kernel_pages, 3928 required_kernelcore); 3929 3930 /* Continue if range is now fully accounted */ 3931 if (end_pfn <= usable_startpfn) { 3932 3933 /* 3934 * Push zone_movable_pfn to the end so 3935 * that if we have to rebalance 3936 * kernelcore across nodes, we will 3937 * not double account here 3938 */ 3939 zone_movable_pfn[nid] = end_pfn; 3940 continue; 3941 } 3942 start_pfn = usable_startpfn; 3943 } 3944 3945 /* 3946 * The usable PFN range for ZONE_MOVABLE is from 3947 * start_pfn->end_pfn. Calculate size_pages as the 3948 * number of pages used as kernelcore 3949 */ 3950 size_pages = end_pfn - start_pfn; 3951 if (size_pages > kernelcore_remaining) 3952 size_pages = kernelcore_remaining; 3953 zone_movable_pfn[nid] = start_pfn + size_pages; 3954 3955 /* 3956 * Some kernelcore has been met, update counts and 3957 * break if the kernelcore for this node has been 3958 * satisified 3959 */ 3960 required_kernelcore -= min(required_kernelcore, 3961 size_pages); 3962 kernelcore_remaining -= size_pages; 3963 if (!kernelcore_remaining) 3964 break; 3965 } 3966 } 3967 3968 /* 3969 * If there is still required_kernelcore, we do another pass with one 3970 * less node in the count. This will push zone_movable_pfn[nid] further 3971 * along on the nodes that still have memory until kernelcore is 3972 * satisified 3973 */ 3974 usable_nodes--; 3975 if (usable_nodes && required_kernelcore > usable_nodes) 3976 goto restart; 3977 3978 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ 3979 for (nid = 0; nid < MAX_NUMNODES; nid++) 3980 zone_movable_pfn[nid] = 3981 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); 3982} 3983 3984/* Any regular memory on that node ? */ 3985static void check_for_regular_memory(pg_data_t *pgdat) 3986{ 3987#ifdef CONFIG_HIGHMEM 3988 enum zone_type zone_type; 3989 3990 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) { 3991 struct zone *zone = &pgdat->node_zones[zone_type]; 3992 if (zone->present_pages) 3993 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY); 3994 } 3995#endif 3996} 3997 3998/** 3999 * free_area_init_nodes - Initialise all pg_data_t and zone data 4000 * @max_zone_pfn: an array of max PFNs for each zone 4001 * 4002 * This will call free_area_init_node() for each active node in the system. 4003 * Using the page ranges provided by add_active_range(), the size of each 4004 * zone in each node and their holes is calculated. If the maximum PFN 4005 * between two adjacent zones match, it is assumed that the zone is empty. 4006 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed 4007 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone 4008 * starts where the previous one ended. For example, ZONE_DMA32 starts 4009 * at arch_max_dma_pfn. 4010 */ 4011void __init free_area_init_nodes(unsigned long *max_zone_pfn) 4012{ 4013 unsigned long nid; 4014 int i; 4015 4016 /* Sort early_node_map as initialisation assumes it is sorted */ 4017 sort_node_map(); 4018 4019 /* Record where the zone boundaries are */ 4020 memset(arch_zone_lowest_possible_pfn, 0, 4021 sizeof(arch_zone_lowest_possible_pfn)); 4022 memset(arch_zone_highest_possible_pfn, 0, 4023 sizeof(arch_zone_highest_possible_pfn)); 4024 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); 4025 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; 4026 for (i = 1; i < MAX_NR_ZONES; i++) { 4027 if (i == ZONE_MOVABLE) 4028 continue; 4029 arch_zone_lowest_possible_pfn[i] = 4030 arch_zone_highest_possible_pfn[i-1]; 4031 arch_zone_highest_possible_pfn[i] = 4032 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); 4033 } 4034 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0; 4035 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0; 4036 4037 /* Find the PFNs that ZONE_MOVABLE begins at in each node */ 4038 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); 4039 find_zone_movable_pfns_for_nodes(zone_movable_pfn); 4040 4041 /* Print out the zone ranges */ 4042 printk("Zone PFN ranges:\n"); 4043 for (i = 0; i < MAX_NR_ZONES; i++) { 4044 if (i == ZONE_MOVABLE) 4045 continue; 4046 printk(" %-8s %0#10lx -> %0#10lx\n", 4047 zone_names[i], 4048 arch_zone_lowest_possible_pfn[i], 4049 arch_zone_highest_possible_pfn[i]); 4050 } 4051 4052 /* Print out the PFNs ZONE_MOVABLE begins at in each node */ 4053 printk("Movable zone start PFN for each node\n"); 4054 for (i = 0; i < MAX_NUMNODES; i++) { 4055 if (zone_movable_pfn[i]) 4056 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]); 4057 } 4058 4059 /* Print out the early_node_map[] */ 4060 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries); 4061 for (i = 0; i < nr_nodemap_entries; i++) 4062 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid, 4063 early_node_map[i].start_pfn, 4064 early_node_map[i].end_pfn); 4065 4066 /* Initialise every node */ 4067 mminit_verify_pageflags_layout(); 4068 setup_nr_node_ids(); 4069 for_each_online_node(nid) { 4070 pg_data_t *pgdat = NODE_DATA(nid); 4071 free_area_init_node(nid, NULL, 4072 find_min_pfn_for_node(nid), NULL); 4073 4074 /* Any memory on that node */ 4075 if (pgdat->node_present_pages) 4076 node_set_state(nid, N_HIGH_MEMORY); 4077 check_for_regular_memory(pgdat); 4078 } 4079} 4080 4081static int __init cmdline_parse_core(char *p, unsigned long *core) 4082{ 4083 unsigned long long coremem; 4084 if (!p) 4085 return -EINVAL; 4086 4087 coremem = memparse(p, &p); 4088 *core = coremem >> PAGE_SHIFT; 4089 4090 /* Paranoid check that UL is enough for the coremem value */ 4091 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); 4092 4093 return 0; 4094} 4095 4096/* 4097 * kernelcore=size sets the amount of memory for use for allocations that 4098 * cannot be reclaimed or migrated. 4099 */ 4100static int __init cmdline_parse_kernelcore(char *p) 4101{ 4102 return cmdline_parse_core(p, &required_kernelcore); 4103} 4104 4105/* 4106 * movablecore=size sets the amount of memory for use for allocations that 4107 * can be reclaimed or migrated. 4108 */ 4109static int __init cmdline_parse_movablecore(char *p) 4110{ 4111 return cmdline_parse_core(p, &required_movablecore); 4112} 4113 4114early_param("kernelcore", cmdline_parse_kernelcore); 4115early_param("movablecore", cmdline_parse_movablecore); 4116 4117#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 4118 4119/** 4120 * set_dma_reserve - set the specified number of pages reserved in the first zone 4121 * @new_dma_reserve: The number of pages to mark reserved 4122 * 4123 * The per-cpu batchsize and zone watermarks are determined by present_pages. 4124 * In the DMA zone, a significant percentage may be consumed by kernel image 4125 * and other unfreeable allocations which can skew the watermarks badly. This 4126 * function may optionally be used to account for unfreeable pages in the 4127 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and 4128 * smaller per-cpu batchsize. 4129 */ 4130void __init set_dma_reserve(unsigned long new_dma_reserve) 4131{ 4132 dma_reserve = new_dma_reserve; 4133} 4134 4135#ifndef CONFIG_NEED_MULTIPLE_NODES 4136struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] }; 4137EXPORT_SYMBOL(contig_page_data); 4138#endif 4139 4140void __init free_area_init(unsigned long *zones_size) 4141{ 4142 free_area_init_node(0, zones_size, 4143 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 4144} 4145 4146static int page_alloc_cpu_notify(struct notifier_block *self, 4147 unsigned long action, void *hcpu) 4148{ 4149 int cpu = (unsigned long)hcpu; 4150 4151 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { 4152 drain_pages(cpu); 4153 4154 /* 4155 * Spill the event counters of the dead processor 4156 * into the current processors event counters. 4157 * This artificially elevates the count of the current 4158 * processor. 4159 */ 4160 vm_events_fold_cpu(cpu); 4161 4162 /* 4163 * Zero the differential counters of the dead processor 4164 * so that the vm statistics are consistent. 4165 * 4166 * This is only okay since the processor is dead and cannot 4167 * race with what we are doing. 4168 */ 4169 refresh_cpu_vm_stats(cpu); 4170 } 4171 return NOTIFY_OK; 4172} 4173 4174void __init page_alloc_init(void) 4175{ 4176 hotcpu_notifier(page_alloc_cpu_notify, 0); 4177} 4178 4179/* 4180 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio 4181 * or min_free_kbytes changes. 4182 */ 4183static void calculate_totalreserve_pages(void) 4184{ 4185 struct pglist_data *pgdat; 4186 unsigned long reserve_pages = 0; 4187 enum zone_type i, j; 4188 4189 for_each_online_pgdat(pgdat) { 4190 for (i = 0; i < MAX_NR_ZONES; i++) { 4191 struct zone *zone = pgdat->node_zones + i; 4192 unsigned long max = 0; 4193 4194 /* Find valid and maximum lowmem_reserve in the zone */ 4195 for (j = i; j < MAX_NR_ZONES; j++) { 4196 if (zone->lowmem_reserve[j] > max) 4197 max = zone->lowmem_reserve[j]; 4198 } 4199 4200 /* we treat pages_high as reserved pages. */ 4201 max += zone->pages_high; 4202 4203 if (max > zone->present_pages) 4204 max = zone->present_pages; 4205 reserve_pages += max; 4206 } 4207 } 4208 totalreserve_pages = reserve_pages; 4209} 4210 4211/* 4212 * setup_per_zone_lowmem_reserve - called whenever 4213 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 4214 * has a correct pages reserved value, so an adequate number of 4215 * pages are left in the zone after a successful __alloc_pages(). 4216 */ 4217static void setup_per_zone_lowmem_reserve(void) 4218{ 4219 struct pglist_data *pgdat; 4220 enum zone_type j, idx; 4221 4222 for_each_online_pgdat(pgdat) { 4223 for (j = 0; j < MAX_NR_ZONES; j++) { 4224 struct zone *zone = pgdat->node_zones + j; 4225 unsigned long present_pages = zone->present_pages; 4226 4227 zone->lowmem_reserve[j] = 0; 4228 4229 idx = j; 4230 while (idx) { 4231 struct zone *lower_zone; 4232 4233 idx--; 4234 4235 if (sysctl_lowmem_reserve_ratio[idx] < 1) 4236 sysctl_lowmem_reserve_ratio[idx] = 1; 4237 4238 lower_zone = pgdat->node_zones + idx; 4239 lower_zone->lowmem_reserve[j] = present_pages / 4240 sysctl_lowmem_reserve_ratio[idx]; 4241 present_pages += lower_zone->present_pages; 4242 } 4243 } 4244 } 4245 4246 /* update totalreserve_pages */ 4247 calculate_totalreserve_pages(); 4248} 4249 4250/** 4251 * setup_per_zone_pages_min - called when min_free_kbytes changes. 4252 * 4253 * Ensures that the pages_{min,low,high} values for each zone are set correctly 4254 * with respect to min_free_kbytes. 4255 */ 4256void setup_per_zone_pages_min(void) 4257{ 4258 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 4259 unsigned long lowmem_pages = 0; 4260 struct zone *zone; 4261 unsigned long flags; 4262 4263 /* Calculate total number of !ZONE_HIGHMEM pages */ 4264 for_each_zone(zone) { 4265 if (!is_highmem(zone)) 4266 lowmem_pages += zone->present_pages; 4267 } 4268 4269 for_each_zone(zone) { 4270 u64 tmp; 4271 4272 spin_lock_irqsave(&zone->lock, flags); 4273 tmp = (u64)pages_min * zone->present_pages; 4274 do_div(tmp, lowmem_pages); 4275 if (is_highmem(zone)) { 4276 /* 4277 * __GFP_HIGH and PF_MEMALLOC allocations usually don't 4278 * need highmem pages, so cap pages_min to a small 4279 * value here. 4280 * 4281 * The (pages_high-pages_low) and (pages_low-pages_min) 4282 * deltas controls asynch page reclaim, and so should 4283 * not be capped for highmem. 4284 */ 4285 int min_pages; 4286 4287 min_pages = zone->present_pages / 1024; 4288 if (min_pages < SWAP_CLUSTER_MAX) 4289 min_pages = SWAP_CLUSTER_MAX; 4290 if (min_pages > 128) 4291 min_pages = 128; 4292 zone->pages_min = min_pages; 4293 } else { 4294 /* 4295 * If it's a lowmem zone, reserve a number of pages 4296 * proportionate to the zone's size. 4297 */ 4298 zone->pages_min = tmp; 4299 } 4300 4301 zone->pages_low = zone->pages_min + (tmp >> 2); 4302 zone->pages_high = zone->pages_min + (tmp >> 1); 4303 setup_zone_migrate_reserve(zone); 4304 spin_unlock_irqrestore(&zone->lock, flags); 4305 } 4306 4307 /* update totalreserve_pages */ 4308 calculate_totalreserve_pages(); 4309} 4310 4311/** 4312 * setup_per_zone_inactive_ratio - called when min_free_kbytes changes. 4313 * 4314 * The inactive anon list should be small enough that the VM never has to 4315 * do too much work, but large enough that each inactive page has a chance 4316 * to be referenced again before it is swapped out. 4317 * 4318 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to 4319 * INACTIVE_ANON pages on this zone's LRU, maintained by the 4320 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of 4321 * the anonymous pages are kept on the inactive list. 4322 * 4323 * total target max 4324 * memory ratio inactive anon 4325 * ------------------------------------- 4326 * 10MB 1 5MB 4327 * 100MB 1 50MB 4328 * 1GB 3 250MB 4329 * 10GB 10 0.9GB 4330 * 100GB 31 3GB 4331 * 1TB 101 10GB 4332 * 10TB 320 32GB 4333 */ 4334static void setup_per_zone_inactive_ratio(void) 4335{ 4336 struct zone *zone; 4337 4338 for_each_zone(zone) { 4339 unsigned int gb, ratio; 4340 4341 /* Zone size in gigabytes */ 4342 gb = zone->present_pages >> (30 - PAGE_SHIFT); 4343 ratio = int_sqrt(10 * gb); 4344 if (!ratio) 4345 ratio = 1; 4346 4347 zone->inactive_ratio = ratio; 4348 } 4349} 4350 4351/* 4352 * Initialise min_free_kbytes. 4353 * 4354 * For small machines we want it small (128k min). For large machines 4355 * we want it large (64MB max). But it is not linear, because network 4356 * bandwidth does not increase linearly with machine size. We use 4357 * 4358 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 4359 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 4360 * 4361 * which yields 4362 * 4363 * 16MB: 512k 4364 * 32MB: 724k 4365 * 64MB: 1024k 4366 * 128MB: 1448k 4367 * 256MB: 2048k 4368 * 512MB: 2896k 4369 * 1024MB: 4096k 4370 * 2048MB: 5792k 4371 * 4096MB: 8192k 4372 * 8192MB: 11584k 4373 * 16384MB: 16384k 4374 */ 4375static int __init init_per_zone_pages_min(void) 4376{ 4377 unsigned long lowmem_kbytes; 4378 4379 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 4380 4381 min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 4382 if (min_free_kbytes < 128) 4383 min_free_kbytes = 128; 4384 if (min_free_kbytes > 65536) 4385 min_free_kbytes = 65536; 4386 setup_per_zone_pages_min(); 4387 setup_per_zone_lowmem_reserve(); 4388 setup_per_zone_inactive_ratio(); 4389 return 0; 4390} 4391module_init(init_per_zone_pages_min) 4392 4393/* 4394 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 4395 * that we can call two helper functions whenever min_free_kbytes 4396 * changes. 4397 */ 4398int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 4399 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4400{ 4401 proc_dointvec(table, write, file, buffer, length, ppos); 4402 if (write) 4403 setup_per_zone_pages_min(); 4404 return 0; 4405} 4406 4407#ifdef CONFIG_NUMA 4408int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, 4409 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4410{ 4411 struct zone *zone; 4412 int rc; 4413 4414 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4415 if (rc) 4416 return rc; 4417 4418 for_each_zone(zone) 4419 zone->min_unmapped_pages = (zone->present_pages * 4420 sysctl_min_unmapped_ratio) / 100; 4421 return 0; 4422} 4423 4424int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write, 4425 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4426{ 4427 struct zone *zone; 4428 int rc; 4429 4430 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4431 if (rc) 4432 return rc; 4433 4434 for_each_zone(zone) 4435 zone->min_slab_pages = (zone->present_pages * 4436 sysctl_min_slab_ratio) / 100; 4437 return 0; 4438} 4439#endif 4440 4441/* 4442 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 4443 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 4444 * whenever sysctl_lowmem_reserve_ratio changes. 4445 * 4446 * The reserve ratio obviously has absolutely no relation with the 4447 * pages_min watermarks. The lowmem reserve ratio can only make sense 4448 * if in function of the boot time zone sizes. 4449 */ 4450int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, 4451 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4452{ 4453 proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4454 setup_per_zone_lowmem_reserve(); 4455 return 0; 4456} 4457 4458/* 4459 * percpu_pagelist_fraction - changes the pcp->high for each zone on each 4460 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist 4461 * can have before it gets flushed back to buddy allocator. 4462 */ 4463 4464int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, 4465 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4466{ 4467 struct zone *zone; 4468 unsigned int cpu; 4469 int ret; 4470 4471 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4472 if (!write || (ret == -EINVAL)) 4473 return ret; 4474 for_each_zone(zone) { 4475 for_each_online_cpu(cpu) { 4476 unsigned long high; 4477 high = zone->present_pages / percpu_pagelist_fraction; 4478 setup_pagelist_highmark(zone_pcp(zone, cpu), high); 4479 } 4480 } 4481 return 0; 4482} 4483 4484int hashdist = HASHDIST_DEFAULT; 4485 4486#ifdef CONFIG_NUMA 4487static int __init set_hashdist(char *str) 4488{ 4489 if (!str) 4490 return 0; 4491 hashdist = simple_strtoul(str, &str, 0); 4492 return 1; 4493} 4494__setup("hashdist=", set_hashdist); 4495#endif 4496 4497/* 4498 * allocate a large system hash table from bootmem 4499 * - it is assumed that the hash table must contain an exact power-of-2 4500 * quantity of entries 4501 * - limit is the number of hash buckets, not the total allocation size 4502 */ 4503void *__init alloc_large_system_hash(const char *tablename, 4504 unsigned long bucketsize, 4505 unsigned long numentries, 4506 int scale, 4507 int flags, 4508 unsigned int *_hash_shift, 4509 unsigned int *_hash_mask, 4510 unsigned long limit) 4511{ 4512 unsigned long long max = limit; 4513 unsigned long log2qty, size; 4514 void *table = NULL; 4515 4516 /* allow the kernel cmdline to have a say */ 4517 if (!numentries) { 4518 /* round applicable memory size up to nearest megabyte */ 4519 numentries = nr_kernel_pages; 4520 numentries += (1UL << (20 - PAGE_SHIFT)) - 1; 4521 numentries >>= 20 - PAGE_SHIFT; 4522 numentries <<= 20 - PAGE_SHIFT; 4523 4524 /* limit to 1 bucket per 2^scale bytes of low memory */ 4525 if (scale > PAGE_SHIFT) 4526 numentries >>= (scale - PAGE_SHIFT); 4527 else 4528 numentries <<= (PAGE_SHIFT - scale); 4529 4530 /* Make sure we've got at least a 0-order allocation.. */ 4531 if (unlikely((numentries * bucketsize) < PAGE_SIZE)) 4532 numentries = PAGE_SIZE / bucketsize; 4533 } 4534 numentries = roundup_pow_of_two(numentries); 4535 4536 /* limit allocation size to 1/16 total memory by default */ 4537 if (max == 0) { 4538 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 4539 do_div(max, bucketsize); 4540 } 4541 4542 if (numentries > max) 4543 numentries = max; 4544 4545 log2qty = ilog2(numentries); 4546 4547 do { 4548 size = bucketsize << log2qty; 4549 if (flags & HASH_EARLY) 4550 table = alloc_bootmem_nopanic(size); 4551 else if (hashdist) 4552 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 4553 else { 4554 unsigned long order = get_order(size); 4555 table = (void*) __get_free_pages(GFP_ATOMIC, order); 4556 /* 4557 * If bucketsize is not a power-of-two, we may free 4558 * some pages at the end of hash table. 4559 */ 4560 if (table) { 4561 unsigned long alloc_end = (unsigned long)table + 4562 (PAGE_SIZE << order); 4563 unsigned long used = (unsigned long)table + 4564 PAGE_ALIGN(size); 4565 split_page(virt_to_page(table), order); 4566 while (used < alloc_end) { 4567 free_page(used); 4568 used += PAGE_SIZE; 4569 } 4570 } 4571 } 4572 } while (!table && size > PAGE_SIZE && --log2qty); 4573 4574 if (!table) 4575 panic("Failed to allocate %s hash table\n", tablename); 4576 4577 printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n", 4578 tablename, 4579 (1U << log2qty), 4580 ilog2(size) - PAGE_SHIFT, 4581 size); 4582 4583 if (_hash_shift) 4584 *_hash_shift = log2qty; 4585 if (_hash_mask) 4586 *_hash_mask = (1 << log2qty) - 1; 4587 4588 return table; 4589} 4590 4591#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE 4592struct page *pfn_to_page(unsigned long pfn) 4593{ 4594 return __pfn_to_page(pfn); 4595} 4596unsigned long page_to_pfn(struct page *page) 4597{ 4598 return __page_to_pfn(page); 4599} 4600EXPORT_SYMBOL(pfn_to_page); 4601EXPORT_SYMBOL(page_to_pfn); 4602#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */ 4603 4604/* Return a pointer to the bitmap storing bits affecting a block of pages */ 4605static inline unsigned long *get_pageblock_bitmap(struct zone *zone, 4606 unsigned long pfn) 4607{ 4608#ifdef CONFIG_SPARSEMEM 4609 return __pfn_to_section(pfn)->pageblock_flags; 4610#else 4611 return zone->pageblock_flags; 4612#endif /* CONFIG_SPARSEMEM */ 4613} 4614 4615static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) 4616{ 4617#ifdef CONFIG_SPARSEMEM 4618 pfn &= (PAGES_PER_SECTION-1); 4619 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 4620#else 4621 pfn = pfn - zone->zone_start_pfn; 4622 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 4623#endif /* CONFIG_SPARSEMEM */ 4624} 4625 4626/** 4627 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages 4628 * @page: The page within the block of interest 4629 * @start_bitidx: The first bit of interest to retrieve 4630 * @end_bitidx: The last bit of interest 4631 * returns pageblock_bits flags 4632 */ 4633unsigned long get_pageblock_flags_group(struct page *page, 4634 int start_bitidx, int end_bitidx) 4635{ 4636 struct zone *zone; 4637 unsigned long *bitmap; 4638 unsigned long pfn, bitidx; 4639 unsigned long flags = 0; 4640 unsigned long value = 1; 4641 4642 zone = page_zone(page); 4643 pfn = page_to_pfn(page); 4644 bitmap = get_pageblock_bitmap(zone, pfn); 4645 bitidx = pfn_to_bitidx(zone, pfn); 4646 4647 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 4648 if (test_bit(bitidx + start_bitidx, bitmap)) 4649 flags |= value; 4650 4651 return flags; 4652} 4653 4654/** 4655 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages 4656 * @page: The page within the block of interest 4657 * @start_bitidx: The first bit of interest 4658 * @end_bitidx: The last bit of interest 4659 * @flags: The flags to set 4660 */ 4661void set_pageblock_flags_group(struct page *page, unsigned long flags, 4662 int start_bitidx, int end_bitidx) 4663{ 4664 struct zone *zone; 4665 unsigned long *bitmap; 4666 unsigned long pfn, bitidx; 4667 unsigned long value = 1; 4668 4669 zone = page_zone(page); 4670 pfn = page_to_pfn(page); 4671 bitmap = get_pageblock_bitmap(zone, pfn); 4672 bitidx = pfn_to_bitidx(zone, pfn); 4673 VM_BUG_ON(pfn < zone->zone_start_pfn); 4674 VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages); 4675 4676 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 4677 if (flags & value) 4678 __set_bit(bitidx + start_bitidx, bitmap); 4679 else 4680 __clear_bit(bitidx + start_bitidx, bitmap); 4681} 4682 4683/* 4684 * This is designed as sub function...plz see page_isolation.c also. 4685 * set/clear page block's type to be ISOLATE. 4686 * page allocater never alloc memory from ISOLATE block. 4687 */ 4688 4689int set_migratetype_isolate(struct page *page) 4690{ 4691 struct zone *zone; 4692 unsigned long flags; 4693 int ret = -EBUSY; 4694 4695 zone = page_zone(page); 4696 spin_lock_irqsave(&zone->lock, flags); 4697 /* 4698 * In future, more migrate types will be able to be isolation target. 4699 */ 4700 if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE) 4701 goto out; 4702 set_pageblock_migratetype(page, MIGRATE_ISOLATE); 4703 move_freepages_block(zone, page, MIGRATE_ISOLATE); 4704 ret = 0; 4705out: 4706 spin_unlock_irqrestore(&zone->lock, flags); 4707 if (!ret) 4708 drain_all_pages(); 4709 return ret; 4710} 4711 4712void unset_migratetype_isolate(struct page *page) 4713{ 4714 struct zone *zone; 4715 unsigned long flags; 4716 zone = page_zone(page); 4717 spin_lock_irqsave(&zone->lock, flags); 4718 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE) 4719 goto out; 4720 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 4721 move_freepages_block(zone, page, MIGRATE_MOVABLE); 4722out: 4723 spin_unlock_irqrestore(&zone->lock, flags); 4724} 4725 4726#ifdef CONFIG_MEMORY_HOTREMOVE 4727/* 4728 * All pages in the range must be isolated before calling this. 4729 */ 4730void 4731__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) 4732{ 4733 struct page *page; 4734 struct zone *zone; 4735 int order, i; 4736 unsigned long pfn; 4737 unsigned long flags; 4738 /* find the first valid pfn */ 4739 for (pfn = start_pfn; pfn < end_pfn; pfn++) 4740 if (pfn_valid(pfn)) 4741 break; 4742 if (pfn == end_pfn) 4743 return; 4744 zone = page_zone(pfn_to_page(pfn)); 4745 spin_lock_irqsave(&zone->lock, flags); 4746 pfn = start_pfn; 4747 while (pfn < end_pfn) { 4748 if (!pfn_valid(pfn)) { 4749 pfn++; 4750 continue; 4751 } 4752 page = pfn_to_page(pfn); 4753 BUG_ON(page_count(page)); 4754 BUG_ON(!PageBuddy(page)); 4755 order = page_order(page); 4756#ifdef CONFIG_DEBUG_VM 4757 printk(KERN_INFO "remove from free list %lx %d %lx\n", 4758 pfn, 1 << order, end_pfn); 4759#endif 4760 list_del(&page->lru); 4761 rmv_page_order(page); 4762 zone->free_area[order].nr_free--; 4763 __mod_zone_page_state(zone, NR_FREE_PAGES, 4764 - (1UL << order)); 4765 for (i = 0; i < (1 << order); i++) 4766 SetPageReserved((page+i)); 4767 pfn += (1 << order); 4768 } 4769 spin_unlock_irqrestore(&zone->lock, flags); 4770} 4771#endif 4772