page_alloc.c revision 985737cf2ea096ea946aed82c7484d40defc71a8
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/memcontrol.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; 72long nr_swap_pages; 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 void *pc = page_get_page_cgroup(page); 227 228 printk(KERN_EMERG "Bad page state in process '%s'\n" KERN_EMERG 229 "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n", 230 current->comm, page, (int)(2*sizeof(unsigned long)), 231 (unsigned long)page->flags, page->mapping, 232 page_mapcount(page), page_count(page)); 233 if (pc) { 234 printk(KERN_EMERG "cgroup:%p\n", pc); 235 page_reset_bad_cgroup(page); 236 } 237 printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n" 238 KERN_EMERG "Backtrace:\n"); 239 dump_stack(); 240 page->flags &= ~PAGE_FLAGS_CLEAR_WHEN_BAD; 241 set_page_count(page, 0); 242 reset_page_mapcount(page); 243 page->mapping = NULL; 244 add_taint(TAINT_BAD_PAGE); 245} 246 247/* 248 * Higher-order pages are called "compound pages". They are structured thusly: 249 * 250 * The first PAGE_SIZE page is called the "head page". 251 * 252 * The remaining PAGE_SIZE pages are called "tail pages". 253 * 254 * All pages have PG_compound set. All pages have their ->private pointing at 255 * the head page (even the head page has this). 256 * 257 * The first tail page's ->lru.next holds the address of the compound page's 258 * put_page() function. Its ->lru.prev holds the order of allocation. 259 * This usage means that zero-order pages may not be compound. 260 */ 261 262static void free_compound_page(struct page *page) 263{ 264 __free_pages_ok(page, compound_order(page)); 265} 266 267void prep_compound_page(struct page *page, unsigned long order) 268{ 269 int i; 270 int nr_pages = 1 << order; 271 struct page *p = page + 1; 272 273 set_compound_page_dtor(page, free_compound_page); 274 set_compound_order(page, order); 275 __SetPageHead(page); 276 for (i = 1; i < nr_pages; i++, p++) { 277 if (unlikely((i & (MAX_ORDER_NR_PAGES - 1)) == 0)) 278 p = pfn_to_page(page_to_pfn(page) + i); 279 __SetPageTail(p); 280 p->first_page = page; 281 } 282} 283 284static void destroy_compound_page(struct page *page, unsigned long order) 285{ 286 int i; 287 int nr_pages = 1 << order; 288 struct page *p = page + 1; 289 290 if (unlikely(compound_order(page) != order)) 291 bad_page(page); 292 293 if (unlikely(!PageHead(page))) 294 bad_page(page); 295 __ClearPageHead(page); 296 for (i = 1; i < nr_pages; i++, p++) { 297 if (unlikely((i & (MAX_ORDER_NR_PAGES - 1)) == 0)) 298 p = pfn_to_page(page_to_pfn(page) + i); 299 300 if (unlikely(!PageTail(p) | 301 (p->first_page != page))) 302 bad_page(page); 303 __ClearPageTail(p); 304 } 305} 306 307static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) 308{ 309 int i; 310 311 /* 312 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO 313 * and __GFP_HIGHMEM from hard or soft interrupt context. 314 */ 315 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); 316 for (i = 0; i < (1 << order); i++) 317 clear_highpage(page + i); 318} 319 320static inline void set_page_order(struct page *page, int order) 321{ 322 set_page_private(page, order); 323 __SetPageBuddy(page); 324} 325 326static inline void rmv_page_order(struct page *page) 327{ 328 __ClearPageBuddy(page); 329 set_page_private(page, 0); 330} 331 332/* 333 * Locate the struct page for both the matching buddy in our 334 * pair (buddy1) and the combined O(n+1) page they form (page). 335 * 336 * 1) Any buddy B1 will have an order O twin B2 which satisfies 337 * the following equation: 338 * B2 = B1 ^ (1 << O) 339 * For example, if the starting buddy (buddy2) is #8 its order 340 * 1 buddy is #10: 341 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 342 * 343 * 2) Any buddy B will have an order O+1 parent P which 344 * satisfies the following equation: 345 * P = B & ~(1 << O) 346 * 347 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 348 */ 349static inline struct page * 350__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order) 351{ 352 unsigned long buddy_idx = page_idx ^ (1 << order); 353 354 return page + (buddy_idx - page_idx); 355} 356 357static inline unsigned long 358__find_combined_index(unsigned long page_idx, unsigned int order) 359{ 360 return (page_idx & ~(1 << order)); 361} 362 363/* 364 * This function checks whether a page is free && is the buddy 365 * we can do coalesce a page and its buddy if 366 * (a) the buddy is not in a hole && 367 * (b) the buddy is in the buddy system && 368 * (c) a page and its buddy have the same order && 369 * (d) a page and its buddy are in the same zone. 370 * 371 * For recording whether a page is in the buddy system, we use PG_buddy. 372 * Setting, clearing, and testing PG_buddy is serialized by zone->lock. 373 * 374 * For recording page's order, we use page_private(page). 375 */ 376static inline int page_is_buddy(struct page *page, struct page *buddy, 377 int order) 378{ 379 if (!pfn_valid_within(page_to_pfn(buddy))) 380 return 0; 381 382 if (page_zone_id(page) != page_zone_id(buddy)) 383 return 0; 384 385 if (PageBuddy(buddy) && page_order(buddy) == order) { 386 BUG_ON(page_count(buddy) != 0); 387 return 1; 388 } 389 return 0; 390} 391 392/* 393 * Freeing function for a buddy system allocator. 394 * 395 * The concept of a buddy system is to maintain direct-mapped table 396 * (containing bit values) for memory blocks of various "orders". 397 * The bottom level table contains the map for the smallest allocatable 398 * units of memory (here, pages), and each level above it describes 399 * pairs of units from the levels below, hence, "buddies". 400 * At a high level, all that happens here is marking the table entry 401 * at the bottom level available, and propagating the changes upward 402 * as necessary, plus some accounting needed to play nicely with other 403 * parts of the VM system. 404 * At each level, we keep a list of pages, which are heads of continuous 405 * free pages of length of (1 << order) and marked with PG_buddy. Page's 406 * order is recorded in page_private(page) field. 407 * So when we are allocating or freeing one, we can derive the state of the 408 * other. That is, if we allocate a small block, and both were 409 * free, the remainder of the region must be split into blocks. 410 * If a block is freed, and its buddy is also free, then this 411 * triggers coalescing into a block of larger size. 412 * 413 * -- wli 414 */ 415 416static inline void __free_one_page(struct page *page, 417 struct zone *zone, unsigned int order) 418{ 419 unsigned long page_idx; 420 int order_size = 1 << order; 421 int migratetype = get_pageblock_migratetype(page); 422 423 if (unlikely(PageCompound(page))) 424 destroy_compound_page(page, order); 425 426 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); 427 428 VM_BUG_ON(page_idx & (order_size - 1)); 429 VM_BUG_ON(bad_range(zone, page)); 430 431 __mod_zone_page_state(zone, NR_FREE_PAGES, order_size); 432 while (order < MAX_ORDER-1) { 433 unsigned long combined_idx; 434 struct page *buddy; 435 436 buddy = __page_find_buddy(page, page_idx, order); 437 if (!page_is_buddy(page, buddy, order)) 438 break; 439 440 /* Our buddy is free, merge with it and move up one order. */ 441 list_del(&buddy->lru); 442 zone->free_area[order].nr_free--; 443 rmv_page_order(buddy); 444 combined_idx = __find_combined_index(page_idx, order); 445 page = page + (combined_idx - page_idx); 446 page_idx = combined_idx; 447 order++; 448 } 449 set_page_order(page, order); 450 list_add(&page->lru, 451 &zone->free_area[order].free_list[migratetype]); 452 zone->free_area[order].nr_free++; 453} 454 455static inline int free_pages_check(struct page *page) 456{ 457 free_page_mlock(page); 458 if (unlikely(page_mapcount(page) | 459 (page->mapping != NULL) | 460 (page_get_page_cgroup(page) != NULL) | 461 (page_count(page) != 0) | 462 (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) 463 bad_page(page); 464 if (PageDirty(page)) 465 __ClearPageDirty(page); 466 if (PageSwapBacked(page)) 467 __ClearPageSwapBacked(page); 468 /* 469 * For now, we report if PG_reserved was found set, but do not 470 * clear it, and do not free the page. But we shall soon need 471 * to do more, for when the ZERO_PAGE count wraps negative. 472 */ 473 return PageReserved(page); 474} 475 476/* 477 * Frees a list of pages. 478 * Assumes all pages on list are in same zone, and of same order. 479 * count is the number of pages to free. 480 * 481 * If the zone was previously in an "all pages pinned" state then look to 482 * see if this freeing clears that state. 483 * 484 * And clear the zone's pages_scanned counter, to hold off the "all pages are 485 * pinned" detection logic. 486 */ 487static void free_pages_bulk(struct zone *zone, int count, 488 struct list_head *list, int order) 489{ 490 spin_lock(&zone->lock); 491 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); 492 zone->pages_scanned = 0; 493 while (count--) { 494 struct page *page; 495 496 VM_BUG_ON(list_empty(list)); 497 page = list_entry(list->prev, struct page, lru); 498 /* have to delete it as __free_one_page list manipulates */ 499 list_del(&page->lru); 500 __free_one_page(page, zone, order); 501 } 502 spin_unlock(&zone->lock); 503} 504 505static void free_one_page(struct zone *zone, struct page *page, int order) 506{ 507 spin_lock(&zone->lock); 508 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); 509 zone->pages_scanned = 0; 510 __free_one_page(page, zone, order); 511 spin_unlock(&zone->lock); 512} 513 514static void __free_pages_ok(struct page *page, unsigned int order) 515{ 516 unsigned long flags; 517 int i; 518 int reserved = 0; 519 520 for (i = 0 ; i < (1 << order) ; ++i) 521 reserved += free_pages_check(page + i); 522 if (reserved) 523 return; 524 525 if (!PageHighMem(page)) { 526 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order); 527 debug_check_no_obj_freed(page_address(page), 528 PAGE_SIZE << order); 529 } 530 arch_free_page(page, order); 531 kernel_map_pages(page, 1 << order, 0); 532 533 local_irq_save(flags); 534 __count_vm_events(PGFREE, 1 << order); 535 free_one_page(page_zone(page), page, order); 536 local_irq_restore(flags); 537} 538 539/* 540 * permit the bootmem allocator to evade page validation on high-order frees 541 */ 542void __meminit __free_pages_bootmem(struct page *page, unsigned int order) 543{ 544 if (order == 0) { 545 __ClearPageReserved(page); 546 set_page_count(page, 0); 547 set_page_refcounted(page); 548 __free_page(page); 549 } else { 550 int loop; 551 552 prefetchw(page); 553 for (loop = 0; loop < BITS_PER_LONG; loop++) { 554 struct page *p = &page[loop]; 555 556 if (loop + 1 < BITS_PER_LONG) 557 prefetchw(p + 1); 558 __ClearPageReserved(p); 559 set_page_count(p, 0); 560 } 561 562 set_page_refcounted(page); 563 __free_pages(page, order); 564 } 565} 566 567 568/* 569 * The order of subdivision here is critical for the IO subsystem. 570 * Please do not alter this order without good reasons and regression 571 * testing. Specifically, as large blocks of memory are subdivided, 572 * the order in which smaller blocks are delivered depends on the order 573 * they're subdivided in this function. This is the primary factor 574 * influencing the order in which pages are delivered to the IO 575 * subsystem according to empirical testing, and this is also justified 576 * by considering the behavior of a buddy system containing a single 577 * large block of memory acted on by a series of small allocations. 578 * This behavior is a critical factor in sglist merging's success. 579 * 580 * -- wli 581 */ 582static inline void expand(struct zone *zone, struct page *page, 583 int low, int high, struct free_area *area, 584 int migratetype) 585{ 586 unsigned long size = 1 << high; 587 588 while (high > low) { 589 area--; 590 high--; 591 size >>= 1; 592 VM_BUG_ON(bad_range(zone, &page[size])); 593 list_add(&page[size].lru, &area->free_list[migratetype]); 594 area->nr_free++; 595 set_page_order(&page[size], high); 596 } 597} 598 599/* 600 * This page is about to be returned from the page allocator 601 */ 602static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) 603{ 604 if (unlikely(page_mapcount(page) | 605 (page->mapping != NULL) | 606 (page_get_page_cgroup(page) != NULL) | 607 (page_count(page) != 0) | 608 (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) 609 bad_page(page); 610 611 /* 612 * For now, we report if PG_reserved was found set, but do not 613 * clear it, and do not allocate the page: as a safety net. 614 */ 615 if (PageReserved(page)) 616 return 1; 617 618 page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_reclaim | 619 1 << PG_referenced | 1 << PG_arch_1 | 620 1 << PG_owner_priv_1 | 1 << PG_mappedtodisk 621#ifdef CONFIG_UNEVICTABLE_LRU 622 | 1 << PG_mlocked 623#endif 624 ); 625 set_page_private(page, 0); 626 set_page_refcounted(page); 627 628 arch_alloc_page(page, order); 629 kernel_map_pages(page, 1 << order, 1); 630 631 if (gfp_flags & __GFP_ZERO) 632 prep_zero_page(page, order, gfp_flags); 633 634 if (order && (gfp_flags & __GFP_COMP)) 635 prep_compound_page(page, order); 636 637 return 0; 638} 639 640/* 641 * Go through the free lists for the given migratetype and remove 642 * the smallest available page from the freelists 643 */ 644static struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, 645 int migratetype) 646{ 647 unsigned int current_order; 648 struct free_area * area; 649 struct page *page; 650 651 /* Find a page of the appropriate size in the preferred list */ 652 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 653 area = &(zone->free_area[current_order]); 654 if (list_empty(&area->free_list[migratetype])) 655 continue; 656 657 page = list_entry(area->free_list[migratetype].next, 658 struct page, lru); 659 list_del(&page->lru); 660 rmv_page_order(page); 661 area->nr_free--; 662 __mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order)); 663 expand(zone, page, order, current_order, area, migratetype); 664 return page; 665 } 666 667 return NULL; 668} 669 670 671/* 672 * This array describes the order lists are fallen back to when 673 * the free lists for the desirable migrate type are depleted 674 */ 675static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = { 676 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 677 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 678 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, 679 [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */ 680}; 681 682/* 683 * Move the free pages in a range to the free lists of the requested type. 684 * Note that start_page and end_pages are not aligned on a pageblock 685 * boundary. If alignment is required, use move_freepages_block() 686 */ 687static int move_freepages(struct zone *zone, 688 struct page *start_page, struct page *end_page, 689 int migratetype) 690{ 691 struct page *page; 692 unsigned long order; 693 int pages_moved = 0; 694 695#ifndef CONFIG_HOLES_IN_ZONE 696 /* 697 * page_zone is not safe to call in this context when 698 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant 699 * anyway as we check zone boundaries in move_freepages_block(). 700 * Remove at a later date when no bug reports exist related to 701 * grouping pages by mobility 702 */ 703 BUG_ON(page_zone(start_page) != page_zone(end_page)); 704#endif 705 706 for (page = start_page; page <= end_page;) { 707 /* Make sure we are not inadvertently changing nodes */ 708 VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone)); 709 710 if (!pfn_valid_within(page_to_pfn(page))) { 711 page++; 712 continue; 713 } 714 715 if (!PageBuddy(page)) { 716 page++; 717 continue; 718 } 719 720 order = page_order(page); 721 list_del(&page->lru); 722 list_add(&page->lru, 723 &zone->free_area[order].free_list[migratetype]); 724 page += 1 << order; 725 pages_moved += 1 << order; 726 } 727 728 return pages_moved; 729} 730 731static int move_freepages_block(struct zone *zone, struct page *page, 732 int migratetype) 733{ 734 unsigned long start_pfn, end_pfn; 735 struct page *start_page, *end_page; 736 737 start_pfn = page_to_pfn(page); 738 start_pfn = start_pfn & ~(pageblock_nr_pages-1); 739 start_page = pfn_to_page(start_pfn); 740 end_page = start_page + pageblock_nr_pages - 1; 741 end_pfn = start_pfn + pageblock_nr_pages - 1; 742 743 /* Do not cross zone boundaries */ 744 if (start_pfn < zone->zone_start_pfn) 745 start_page = page; 746 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages) 747 return 0; 748 749 return move_freepages(zone, start_page, end_page, migratetype); 750} 751 752/* Remove an element from the buddy allocator from the fallback list */ 753static struct page *__rmqueue_fallback(struct zone *zone, int order, 754 int start_migratetype) 755{ 756 struct free_area * area; 757 int current_order; 758 struct page *page; 759 int migratetype, i; 760 761 /* Find the largest possible block of pages in the other list */ 762 for (current_order = MAX_ORDER-1; current_order >= order; 763 --current_order) { 764 for (i = 0; i < MIGRATE_TYPES - 1; i++) { 765 migratetype = fallbacks[start_migratetype][i]; 766 767 /* MIGRATE_RESERVE handled later if necessary */ 768 if (migratetype == MIGRATE_RESERVE) 769 continue; 770 771 area = &(zone->free_area[current_order]); 772 if (list_empty(&area->free_list[migratetype])) 773 continue; 774 775 page = list_entry(area->free_list[migratetype].next, 776 struct page, lru); 777 area->nr_free--; 778 779 /* 780 * If breaking a large block of pages, move all free 781 * pages to the preferred allocation list. If falling 782 * back for a reclaimable kernel allocation, be more 783 * agressive about taking ownership of free pages 784 */ 785 if (unlikely(current_order >= (pageblock_order >> 1)) || 786 start_migratetype == MIGRATE_RECLAIMABLE) { 787 unsigned long pages; 788 pages = move_freepages_block(zone, page, 789 start_migratetype); 790 791 /* Claim the whole block if over half of it is free */ 792 if (pages >= (1 << (pageblock_order-1))) 793 set_pageblock_migratetype(page, 794 start_migratetype); 795 796 migratetype = start_migratetype; 797 } 798 799 /* Remove the page from the freelists */ 800 list_del(&page->lru); 801 rmv_page_order(page); 802 __mod_zone_page_state(zone, NR_FREE_PAGES, 803 -(1UL << order)); 804 805 if (current_order == pageblock_order) 806 set_pageblock_migratetype(page, 807 start_migratetype); 808 809 expand(zone, page, order, current_order, area, migratetype); 810 return page; 811 } 812 } 813 814 /* Use MIGRATE_RESERVE rather than fail an allocation */ 815 return __rmqueue_smallest(zone, order, MIGRATE_RESERVE); 816} 817 818/* 819 * Do the hard work of removing an element from the buddy allocator. 820 * Call me with the zone->lock already held. 821 */ 822static struct page *__rmqueue(struct zone *zone, unsigned int order, 823 int migratetype) 824{ 825 struct page *page; 826 827 page = __rmqueue_smallest(zone, order, migratetype); 828 829 if (unlikely(!page)) 830 page = __rmqueue_fallback(zone, order, migratetype); 831 832 return page; 833} 834 835/* 836 * Obtain a specified number of elements from the buddy allocator, all under 837 * a single hold of the lock, for efficiency. Add them to the supplied list. 838 * Returns the number of new pages which were placed at *list. 839 */ 840static int rmqueue_bulk(struct zone *zone, unsigned int order, 841 unsigned long count, struct list_head *list, 842 int migratetype) 843{ 844 int i; 845 846 spin_lock(&zone->lock); 847 for (i = 0; i < count; ++i) { 848 struct page *page = __rmqueue(zone, order, migratetype); 849 if (unlikely(page == NULL)) 850 break; 851 852 /* 853 * Split buddy pages returned by expand() are received here 854 * in physical page order. The page is added to the callers and 855 * list and the list head then moves forward. From the callers 856 * perspective, the linked list is ordered by page number in 857 * some conditions. This is useful for IO devices that can 858 * merge IO requests if the physical pages are ordered 859 * properly. 860 */ 861 list_add(&page->lru, list); 862 set_page_private(page, migratetype); 863 list = &page->lru; 864 } 865 spin_unlock(&zone->lock); 866 return i; 867} 868 869#ifdef CONFIG_NUMA 870/* 871 * Called from the vmstat counter updater to drain pagesets of this 872 * currently executing processor on remote nodes after they have 873 * expired. 874 * 875 * Note that this function must be called with the thread pinned to 876 * a single processor. 877 */ 878void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) 879{ 880 unsigned long flags; 881 int to_drain; 882 883 local_irq_save(flags); 884 if (pcp->count >= pcp->batch) 885 to_drain = pcp->batch; 886 else 887 to_drain = pcp->count; 888 free_pages_bulk(zone, to_drain, &pcp->list, 0); 889 pcp->count -= to_drain; 890 local_irq_restore(flags); 891} 892#endif 893 894/* 895 * Drain pages of the indicated processor. 896 * 897 * The processor must either be the current processor and the 898 * thread pinned to the current processor or a processor that 899 * is not online. 900 */ 901static void drain_pages(unsigned int cpu) 902{ 903 unsigned long flags; 904 struct zone *zone; 905 906 for_each_zone(zone) { 907 struct per_cpu_pageset *pset; 908 struct per_cpu_pages *pcp; 909 910 if (!populated_zone(zone)) 911 continue; 912 913 pset = zone_pcp(zone, cpu); 914 915 pcp = &pset->pcp; 916 local_irq_save(flags); 917 free_pages_bulk(zone, pcp->count, &pcp->list, 0); 918 pcp->count = 0; 919 local_irq_restore(flags); 920 } 921} 922 923/* 924 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 925 */ 926void drain_local_pages(void *arg) 927{ 928 drain_pages(smp_processor_id()); 929} 930 931/* 932 * Spill all the per-cpu pages from all CPUs back into the buddy allocator 933 */ 934void drain_all_pages(void) 935{ 936 on_each_cpu(drain_local_pages, NULL, 1); 937} 938 939#ifdef CONFIG_HIBERNATION 940 941void mark_free_pages(struct zone *zone) 942{ 943 unsigned long pfn, max_zone_pfn; 944 unsigned long flags; 945 int order, t; 946 struct list_head *curr; 947 948 if (!zone->spanned_pages) 949 return; 950 951 spin_lock_irqsave(&zone->lock, flags); 952 953 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; 954 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 955 if (pfn_valid(pfn)) { 956 struct page *page = pfn_to_page(pfn); 957 958 if (!swsusp_page_is_forbidden(page)) 959 swsusp_unset_page_free(page); 960 } 961 962 for_each_migratetype_order(order, t) { 963 list_for_each(curr, &zone->free_area[order].free_list[t]) { 964 unsigned long i; 965 966 pfn = page_to_pfn(list_entry(curr, struct page, lru)); 967 for (i = 0; i < (1UL << order); i++) 968 swsusp_set_page_free(pfn_to_page(pfn + i)); 969 } 970 } 971 spin_unlock_irqrestore(&zone->lock, flags); 972} 973#endif /* CONFIG_PM */ 974 975/* 976 * Free a 0-order page 977 */ 978static void free_hot_cold_page(struct page *page, int cold) 979{ 980 struct zone *zone = page_zone(page); 981 struct per_cpu_pages *pcp; 982 unsigned long flags; 983 984 if (PageAnon(page)) 985 page->mapping = NULL; 986 if (free_pages_check(page)) 987 return; 988 989 if (!PageHighMem(page)) { 990 debug_check_no_locks_freed(page_address(page), PAGE_SIZE); 991 debug_check_no_obj_freed(page_address(page), PAGE_SIZE); 992 } 993 arch_free_page(page, 0); 994 kernel_map_pages(page, 1, 0); 995 996 pcp = &zone_pcp(zone, get_cpu())->pcp; 997 local_irq_save(flags); 998 __count_vm_event(PGFREE); 999 if (cold) 1000 list_add_tail(&page->lru, &pcp->list); 1001 else 1002 list_add(&page->lru, &pcp->list); 1003 set_page_private(page, get_pageblock_migratetype(page)); 1004 pcp->count++; 1005 if (pcp->count >= pcp->high) { 1006 free_pages_bulk(zone, pcp->batch, &pcp->list, 0); 1007 pcp->count -= pcp->batch; 1008 } 1009 local_irq_restore(flags); 1010 put_cpu(); 1011} 1012 1013void free_hot_page(struct page *page) 1014{ 1015 free_hot_cold_page(page, 0); 1016} 1017 1018void free_cold_page(struct page *page) 1019{ 1020 free_hot_cold_page(page, 1); 1021} 1022 1023/* 1024 * split_page takes a non-compound higher-order page, and splits it into 1025 * n (1<<order) sub-pages: page[0..n] 1026 * Each sub-page must be freed individually. 1027 * 1028 * Note: this is probably too low level an operation for use in drivers. 1029 * Please consult with lkml before using this in your driver. 1030 */ 1031void split_page(struct page *page, unsigned int order) 1032{ 1033 int i; 1034 1035 VM_BUG_ON(PageCompound(page)); 1036 VM_BUG_ON(!page_count(page)); 1037 for (i = 1; i < (1 << order); i++) 1038 set_page_refcounted(page + i); 1039} 1040 1041/* 1042 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 1043 * we cheat by calling it from here, in the order > 0 path. Saves a branch 1044 * or two. 1045 */ 1046static struct page *buffered_rmqueue(struct zone *preferred_zone, 1047 struct zone *zone, int order, gfp_t gfp_flags) 1048{ 1049 unsigned long flags; 1050 struct page *page; 1051 int cold = !!(gfp_flags & __GFP_COLD); 1052 int cpu; 1053 int migratetype = allocflags_to_migratetype(gfp_flags); 1054 1055again: 1056 cpu = get_cpu(); 1057 if (likely(order == 0)) { 1058 struct per_cpu_pages *pcp; 1059 1060 pcp = &zone_pcp(zone, cpu)->pcp; 1061 local_irq_save(flags); 1062 if (!pcp->count) { 1063 pcp->count = rmqueue_bulk(zone, 0, 1064 pcp->batch, &pcp->list, migratetype); 1065 if (unlikely(!pcp->count)) 1066 goto failed; 1067 } 1068 1069 /* Find a page of the appropriate migrate type */ 1070 if (cold) { 1071 list_for_each_entry_reverse(page, &pcp->list, lru) 1072 if (page_private(page) == migratetype) 1073 break; 1074 } else { 1075 list_for_each_entry(page, &pcp->list, lru) 1076 if (page_private(page) == migratetype) 1077 break; 1078 } 1079 1080 /* Allocate more to the pcp list if necessary */ 1081 if (unlikely(&page->lru == &pcp->list)) { 1082 pcp->count += rmqueue_bulk(zone, 0, 1083 pcp->batch, &pcp->list, migratetype); 1084 page = list_entry(pcp->list.next, struct page, lru); 1085 } 1086 1087 list_del(&page->lru); 1088 pcp->count--; 1089 } else { 1090 spin_lock_irqsave(&zone->lock, flags); 1091 page = __rmqueue(zone, order, migratetype); 1092 spin_unlock(&zone->lock); 1093 if (!page) 1094 goto failed; 1095 } 1096 1097 __count_zone_vm_events(PGALLOC, zone, 1 << order); 1098 zone_statistics(preferred_zone, zone); 1099 local_irq_restore(flags); 1100 put_cpu(); 1101 1102 VM_BUG_ON(bad_range(zone, page)); 1103 if (prep_new_page(page, order, gfp_flags)) 1104 goto again; 1105 return page; 1106 1107failed: 1108 local_irq_restore(flags); 1109 put_cpu(); 1110 return NULL; 1111} 1112 1113#define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */ 1114#define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */ 1115#define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */ 1116#define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */ 1117#define ALLOC_HARDER 0x10 /* try to alloc harder */ 1118#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 1119#define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 1120 1121#ifdef CONFIG_FAIL_PAGE_ALLOC 1122 1123static struct fail_page_alloc_attr { 1124 struct fault_attr attr; 1125 1126 u32 ignore_gfp_highmem; 1127 u32 ignore_gfp_wait; 1128 u32 min_order; 1129 1130#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1131 1132 struct dentry *ignore_gfp_highmem_file; 1133 struct dentry *ignore_gfp_wait_file; 1134 struct dentry *min_order_file; 1135 1136#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1137 1138} fail_page_alloc = { 1139 .attr = FAULT_ATTR_INITIALIZER, 1140 .ignore_gfp_wait = 1, 1141 .ignore_gfp_highmem = 1, 1142 .min_order = 1, 1143}; 1144 1145static int __init setup_fail_page_alloc(char *str) 1146{ 1147 return setup_fault_attr(&fail_page_alloc.attr, str); 1148} 1149__setup("fail_page_alloc=", setup_fail_page_alloc); 1150 1151static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1152{ 1153 if (order < fail_page_alloc.min_order) 1154 return 0; 1155 if (gfp_mask & __GFP_NOFAIL) 1156 return 0; 1157 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 1158 return 0; 1159 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) 1160 return 0; 1161 1162 return should_fail(&fail_page_alloc.attr, 1 << order); 1163} 1164 1165#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1166 1167static int __init fail_page_alloc_debugfs(void) 1168{ 1169 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; 1170 struct dentry *dir; 1171 int err; 1172 1173 err = init_fault_attr_dentries(&fail_page_alloc.attr, 1174 "fail_page_alloc"); 1175 if (err) 1176 return err; 1177 dir = fail_page_alloc.attr.dentries.dir; 1178 1179 fail_page_alloc.ignore_gfp_wait_file = 1180 debugfs_create_bool("ignore-gfp-wait", mode, dir, 1181 &fail_page_alloc.ignore_gfp_wait); 1182 1183 fail_page_alloc.ignore_gfp_highmem_file = 1184 debugfs_create_bool("ignore-gfp-highmem", mode, dir, 1185 &fail_page_alloc.ignore_gfp_highmem); 1186 fail_page_alloc.min_order_file = 1187 debugfs_create_u32("min-order", mode, dir, 1188 &fail_page_alloc.min_order); 1189 1190 if (!fail_page_alloc.ignore_gfp_wait_file || 1191 !fail_page_alloc.ignore_gfp_highmem_file || 1192 !fail_page_alloc.min_order_file) { 1193 err = -ENOMEM; 1194 debugfs_remove(fail_page_alloc.ignore_gfp_wait_file); 1195 debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file); 1196 debugfs_remove(fail_page_alloc.min_order_file); 1197 cleanup_fault_attr_dentries(&fail_page_alloc.attr); 1198 } 1199 1200 return err; 1201} 1202 1203late_initcall(fail_page_alloc_debugfs); 1204 1205#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1206 1207#else /* CONFIG_FAIL_PAGE_ALLOC */ 1208 1209static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1210{ 1211 return 0; 1212} 1213 1214#endif /* CONFIG_FAIL_PAGE_ALLOC */ 1215 1216/* 1217 * Return 1 if free pages are above 'mark'. This takes into account the order 1218 * of the allocation. 1219 */ 1220int zone_watermark_ok(struct zone *z, int order, unsigned long mark, 1221 int classzone_idx, int alloc_flags) 1222{ 1223 /* free_pages my go negative - that's OK */ 1224 long min = mark; 1225 long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1; 1226 int o; 1227 1228 if (alloc_flags & ALLOC_HIGH) 1229 min -= min / 2; 1230 if (alloc_flags & ALLOC_HARDER) 1231 min -= min / 4; 1232 1233 if (free_pages <= min + z->lowmem_reserve[classzone_idx]) 1234 return 0; 1235 for (o = 0; o < order; o++) { 1236 /* At the next order, this order's pages become unavailable */ 1237 free_pages -= z->free_area[o].nr_free << o; 1238 1239 /* Require fewer higher order pages to be free */ 1240 min >>= 1; 1241 1242 if (free_pages <= min) 1243 return 0; 1244 } 1245 return 1; 1246} 1247 1248#ifdef CONFIG_NUMA 1249/* 1250 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to 1251 * skip over zones that are not allowed by the cpuset, or that have 1252 * been recently (in last second) found to be nearly full. See further 1253 * comments in mmzone.h. Reduces cache footprint of zonelist scans 1254 * that have to skip over a lot of full or unallowed zones. 1255 * 1256 * If the zonelist cache is present in the passed in zonelist, then 1257 * returns a pointer to the allowed node mask (either the current 1258 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].) 1259 * 1260 * If the zonelist cache is not available for this zonelist, does 1261 * nothing and returns NULL. 1262 * 1263 * If the fullzones BITMAP in the zonelist cache is stale (more than 1264 * a second since last zap'd) then we zap it out (clear its bits.) 1265 * 1266 * We hold off even calling zlc_setup, until after we've checked the 1267 * first zone in the zonelist, on the theory that most allocations will 1268 * be satisfied from that first zone, so best to examine that zone as 1269 * quickly as we can. 1270 */ 1271static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1272{ 1273 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1274 nodemask_t *allowednodes; /* zonelist_cache approximation */ 1275 1276 zlc = zonelist->zlcache_ptr; 1277 if (!zlc) 1278 return NULL; 1279 1280 if (time_after(jiffies, zlc->last_full_zap + HZ)) { 1281 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1282 zlc->last_full_zap = jiffies; 1283 } 1284 1285 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? 1286 &cpuset_current_mems_allowed : 1287 &node_states[N_HIGH_MEMORY]; 1288 return allowednodes; 1289} 1290 1291/* 1292 * Given 'z' scanning a zonelist, run a couple of quick checks to see 1293 * if it is worth looking at further for free memory: 1294 * 1) Check that the zone isn't thought to be full (doesn't have its 1295 * bit set in the zonelist_cache fullzones BITMAP). 1296 * 2) Check that the zones node (obtained from the zonelist_cache 1297 * z_to_n[] mapping) is allowed in the passed in allowednodes mask. 1298 * Return true (non-zero) if zone is worth looking at further, or 1299 * else return false (zero) if it is not. 1300 * 1301 * This check -ignores- the distinction between various watermarks, 1302 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is 1303 * found to be full for any variation of these watermarks, it will 1304 * be considered full for up to one second by all requests, unless 1305 * we are so low on memory on all allowed nodes that we are forced 1306 * into the second scan of the zonelist. 1307 * 1308 * In the second scan we ignore this zonelist cache and exactly 1309 * apply the watermarks to all zones, even it is slower to do so. 1310 * We are low on memory in the second scan, and should leave no stone 1311 * unturned looking for a free page. 1312 */ 1313static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1314 nodemask_t *allowednodes) 1315{ 1316 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1317 int i; /* index of *z in zonelist zones */ 1318 int n; /* node that zone *z is on */ 1319 1320 zlc = zonelist->zlcache_ptr; 1321 if (!zlc) 1322 return 1; 1323 1324 i = z - zonelist->_zonerefs; 1325 n = zlc->z_to_n[i]; 1326 1327 /* This zone is worth trying if it is allowed but not full */ 1328 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); 1329} 1330 1331/* 1332 * Given 'z' scanning a zonelist, set the corresponding bit in 1333 * zlc->fullzones, so that subsequent attempts to allocate a page 1334 * from that zone don't waste time re-examining it. 1335 */ 1336static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1337{ 1338 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1339 int i; /* index of *z in zonelist zones */ 1340 1341 zlc = zonelist->zlcache_ptr; 1342 if (!zlc) 1343 return; 1344 1345 i = z - zonelist->_zonerefs; 1346 1347 set_bit(i, zlc->fullzones); 1348} 1349 1350#else /* CONFIG_NUMA */ 1351 1352static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1353{ 1354 return NULL; 1355} 1356 1357static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1358 nodemask_t *allowednodes) 1359{ 1360 return 1; 1361} 1362 1363static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1364{ 1365} 1366#endif /* CONFIG_NUMA */ 1367 1368/* 1369 * get_page_from_freelist goes through the zonelist trying to allocate 1370 * a page. 1371 */ 1372static struct page * 1373get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order, 1374 struct zonelist *zonelist, int high_zoneidx, int alloc_flags) 1375{ 1376 struct zoneref *z; 1377 struct page *page = NULL; 1378 int classzone_idx; 1379 struct zone *zone, *preferred_zone; 1380 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ 1381 int zlc_active = 0; /* set if using zonelist_cache */ 1382 int did_zlc_setup = 0; /* just call zlc_setup() one time */ 1383 1384 (void)first_zones_zonelist(zonelist, high_zoneidx, nodemask, 1385 &preferred_zone); 1386 if (!preferred_zone) 1387 return NULL; 1388 1389 classzone_idx = zone_idx(preferred_zone); 1390 1391zonelist_scan: 1392 /* 1393 * Scan zonelist, looking for a zone with enough free. 1394 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1395 */ 1396 for_each_zone_zonelist_nodemask(zone, z, zonelist, 1397 high_zoneidx, nodemask) { 1398 if (NUMA_BUILD && zlc_active && 1399 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 1400 continue; 1401 if ((alloc_flags & ALLOC_CPUSET) && 1402 !cpuset_zone_allowed_softwall(zone, gfp_mask)) 1403 goto try_next_zone; 1404 1405 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { 1406 unsigned long mark; 1407 if (alloc_flags & ALLOC_WMARK_MIN) 1408 mark = zone->pages_min; 1409 else if (alloc_flags & ALLOC_WMARK_LOW) 1410 mark = zone->pages_low; 1411 else 1412 mark = zone->pages_high; 1413 if (!zone_watermark_ok(zone, order, mark, 1414 classzone_idx, alloc_flags)) { 1415 if (!zone_reclaim_mode || 1416 !zone_reclaim(zone, gfp_mask, order)) 1417 goto this_zone_full; 1418 } 1419 } 1420 1421 page = buffered_rmqueue(preferred_zone, zone, order, gfp_mask); 1422 if (page) 1423 break; 1424this_zone_full: 1425 if (NUMA_BUILD) 1426 zlc_mark_zone_full(zonelist, z); 1427try_next_zone: 1428 if (NUMA_BUILD && !did_zlc_setup) { 1429 /* we do zlc_setup after the first zone is tried */ 1430 allowednodes = zlc_setup(zonelist, alloc_flags); 1431 zlc_active = 1; 1432 did_zlc_setup = 1; 1433 } 1434 } 1435 1436 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) { 1437 /* Disable zlc cache for second zonelist scan */ 1438 zlc_active = 0; 1439 goto zonelist_scan; 1440 } 1441 return page; 1442} 1443 1444/* 1445 * This is the 'heart' of the zoned buddy allocator. 1446 */ 1447struct page * 1448__alloc_pages_internal(gfp_t gfp_mask, unsigned int order, 1449 struct zonelist *zonelist, nodemask_t *nodemask) 1450{ 1451 const gfp_t wait = gfp_mask & __GFP_WAIT; 1452 enum zone_type high_zoneidx = gfp_zone(gfp_mask); 1453 struct zoneref *z; 1454 struct zone *zone; 1455 struct page *page; 1456 struct reclaim_state reclaim_state; 1457 struct task_struct *p = current; 1458 int do_retry; 1459 int alloc_flags; 1460 unsigned long did_some_progress; 1461 unsigned long pages_reclaimed = 0; 1462 1463 might_sleep_if(wait); 1464 1465 if (should_fail_alloc_page(gfp_mask, order)) 1466 return NULL; 1467 1468restart: 1469 z = zonelist->_zonerefs; /* the list of zones suitable for gfp_mask */ 1470 1471 if (unlikely(!z->zone)) { 1472 /* 1473 * Happens if we have an empty zonelist as a result of 1474 * GFP_THISNODE being used on a memoryless node 1475 */ 1476 return NULL; 1477 } 1478 1479 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order, 1480 zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET); 1481 if (page) 1482 goto got_pg; 1483 1484 /* 1485 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and 1486 * __GFP_NOWARN set) should not cause reclaim since the subsystem 1487 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim 1488 * using a larger set of nodes after it has established that the 1489 * allowed per node queues are empty and that nodes are 1490 * over allocated. 1491 */ 1492 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) 1493 goto nopage; 1494 1495 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) 1496 wakeup_kswapd(zone, order); 1497 1498 /* 1499 * OK, we're below the kswapd watermark and have kicked background 1500 * reclaim. Now things get more complex, so set up alloc_flags according 1501 * to how we want to proceed. 1502 * 1503 * The caller may dip into page reserves a bit more if the caller 1504 * cannot run direct reclaim, or if the caller has realtime scheduling 1505 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will 1506 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). 1507 */ 1508 alloc_flags = ALLOC_WMARK_MIN; 1509 if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait) 1510 alloc_flags |= ALLOC_HARDER; 1511 if (gfp_mask & __GFP_HIGH) 1512 alloc_flags |= ALLOC_HIGH; 1513 if (wait) 1514 alloc_flags |= ALLOC_CPUSET; 1515 1516 /* 1517 * Go through the zonelist again. Let __GFP_HIGH and allocations 1518 * coming from realtime tasks go deeper into reserves. 1519 * 1520 * This is the last chance, in general, before the goto nopage. 1521 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. 1522 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1523 */ 1524 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, 1525 high_zoneidx, alloc_flags); 1526 if (page) 1527 goto got_pg; 1528 1529 /* This allocation should allow future memory freeing. */ 1530 1531rebalance: 1532 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) 1533 && !in_interrupt()) { 1534 if (!(gfp_mask & __GFP_NOMEMALLOC)) { 1535nofail_alloc: 1536 /* go through the zonelist yet again, ignoring mins */ 1537 page = get_page_from_freelist(gfp_mask, nodemask, order, 1538 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS); 1539 if (page) 1540 goto got_pg; 1541 if (gfp_mask & __GFP_NOFAIL) { 1542 congestion_wait(WRITE, HZ/50); 1543 goto nofail_alloc; 1544 } 1545 } 1546 goto nopage; 1547 } 1548 1549 /* Atomic allocations - we can't balance anything */ 1550 if (!wait) 1551 goto nopage; 1552 1553 cond_resched(); 1554 1555 /* We now go into synchronous reclaim */ 1556 cpuset_memory_pressure_bump(); 1557 p->flags |= PF_MEMALLOC; 1558 reclaim_state.reclaimed_slab = 0; 1559 p->reclaim_state = &reclaim_state; 1560 1561 did_some_progress = try_to_free_pages(zonelist, order, gfp_mask); 1562 1563 p->reclaim_state = NULL; 1564 p->flags &= ~PF_MEMALLOC; 1565 1566 cond_resched(); 1567 1568 if (order != 0) 1569 drain_all_pages(); 1570 1571 if (likely(did_some_progress)) { 1572 page = get_page_from_freelist(gfp_mask, nodemask, order, 1573 zonelist, high_zoneidx, alloc_flags); 1574 if (page) 1575 goto got_pg; 1576 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { 1577 if (!try_set_zone_oom(zonelist, gfp_mask)) { 1578 schedule_timeout_uninterruptible(1); 1579 goto restart; 1580 } 1581 1582 /* 1583 * Go through the zonelist yet one more time, keep 1584 * very high watermark here, this is only to catch 1585 * a parallel oom killing, we must fail if we're still 1586 * under heavy pressure. 1587 */ 1588 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, 1589 order, zonelist, high_zoneidx, 1590 ALLOC_WMARK_HIGH|ALLOC_CPUSET); 1591 if (page) { 1592 clear_zonelist_oom(zonelist, gfp_mask); 1593 goto got_pg; 1594 } 1595 1596 /* The OOM killer will not help higher order allocs so fail */ 1597 if (order > PAGE_ALLOC_COSTLY_ORDER) { 1598 clear_zonelist_oom(zonelist, gfp_mask); 1599 goto nopage; 1600 } 1601 1602 out_of_memory(zonelist, gfp_mask, order); 1603 clear_zonelist_oom(zonelist, gfp_mask); 1604 goto restart; 1605 } 1606 1607 /* 1608 * Don't let big-order allocations loop unless the caller explicitly 1609 * requests that. Wait for some write requests to complete then retry. 1610 * 1611 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER 1612 * means __GFP_NOFAIL, but that may not be true in other 1613 * implementations. 1614 * 1615 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is 1616 * specified, then we retry until we no longer reclaim any pages 1617 * (above), or we've reclaimed an order of pages at least as 1618 * large as the allocation's order. In both cases, if the 1619 * allocation still fails, we stop retrying. 1620 */ 1621 pages_reclaimed += did_some_progress; 1622 do_retry = 0; 1623 if (!(gfp_mask & __GFP_NORETRY)) { 1624 if (order <= PAGE_ALLOC_COSTLY_ORDER) { 1625 do_retry = 1; 1626 } else { 1627 if (gfp_mask & __GFP_REPEAT && 1628 pages_reclaimed < (1 << order)) 1629 do_retry = 1; 1630 } 1631 if (gfp_mask & __GFP_NOFAIL) 1632 do_retry = 1; 1633 } 1634 if (do_retry) { 1635 congestion_wait(WRITE, HZ/50); 1636 goto rebalance; 1637 } 1638 1639nopage: 1640 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { 1641 printk(KERN_WARNING "%s: page allocation failure." 1642 " order:%d, mode:0x%x\n", 1643 p->comm, order, gfp_mask); 1644 dump_stack(); 1645 show_mem(); 1646 } 1647got_pg: 1648 return page; 1649} 1650EXPORT_SYMBOL(__alloc_pages_internal); 1651 1652/* 1653 * Common helper functions. 1654 */ 1655unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 1656{ 1657 struct page * page; 1658 page = alloc_pages(gfp_mask, order); 1659 if (!page) 1660 return 0; 1661 return (unsigned long) page_address(page); 1662} 1663 1664EXPORT_SYMBOL(__get_free_pages); 1665 1666unsigned long get_zeroed_page(gfp_t gfp_mask) 1667{ 1668 struct page * page; 1669 1670 /* 1671 * get_zeroed_page() returns a 32-bit address, which cannot represent 1672 * a highmem page 1673 */ 1674 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 1675 1676 page = alloc_pages(gfp_mask | __GFP_ZERO, 0); 1677 if (page) 1678 return (unsigned long) page_address(page); 1679 return 0; 1680} 1681 1682EXPORT_SYMBOL(get_zeroed_page); 1683 1684void __pagevec_free(struct pagevec *pvec) 1685{ 1686 int i = pagevec_count(pvec); 1687 1688 while (--i >= 0) 1689 free_hot_cold_page(pvec->pages[i], pvec->cold); 1690} 1691 1692void __free_pages(struct page *page, unsigned int order) 1693{ 1694 if (put_page_testzero(page)) { 1695 if (order == 0) 1696 free_hot_page(page); 1697 else 1698 __free_pages_ok(page, order); 1699 } 1700} 1701 1702EXPORT_SYMBOL(__free_pages); 1703 1704void free_pages(unsigned long addr, unsigned int order) 1705{ 1706 if (addr != 0) { 1707 VM_BUG_ON(!virt_addr_valid((void *)addr)); 1708 __free_pages(virt_to_page((void *)addr), order); 1709 } 1710} 1711 1712EXPORT_SYMBOL(free_pages); 1713 1714/** 1715 * alloc_pages_exact - allocate an exact number physically-contiguous pages. 1716 * @size: the number of bytes to allocate 1717 * @gfp_mask: GFP flags for the allocation 1718 * 1719 * This function is similar to alloc_pages(), except that it allocates the 1720 * minimum number of pages to satisfy the request. alloc_pages() can only 1721 * allocate memory in power-of-two pages. 1722 * 1723 * This function is also limited by MAX_ORDER. 1724 * 1725 * Memory allocated by this function must be released by free_pages_exact(). 1726 */ 1727void *alloc_pages_exact(size_t size, gfp_t gfp_mask) 1728{ 1729 unsigned int order = get_order(size); 1730 unsigned long addr; 1731 1732 addr = __get_free_pages(gfp_mask, order); 1733 if (addr) { 1734 unsigned long alloc_end = addr + (PAGE_SIZE << order); 1735 unsigned long used = addr + PAGE_ALIGN(size); 1736 1737 split_page(virt_to_page(addr), order); 1738 while (used < alloc_end) { 1739 free_page(used); 1740 used += PAGE_SIZE; 1741 } 1742 } 1743 1744 return (void *)addr; 1745} 1746EXPORT_SYMBOL(alloc_pages_exact); 1747 1748/** 1749 * free_pages_exact - release memory allocated via alloc_pages_exact() 1750 * @virt: the value returned by alloc_pages_exact. 1751 * @size: size of allocation, same value as passed to alloc_pages_exact(). 1752 * 1753 * Release the memory allocated by a previous call to alloc_pages_exact. 1754 */ 1755void free_pages_exact(void *virt, size_t size) 1756{ 1757 unsigned long addr = (unsigned long)virt; 1758 unsigned long end = addr + PAGE_ALIGN(size); 1759 1760 while (addr < end) { 1761 free_page(addr); 1762 addr += PAGE_SIZE; 1763 } 1764} 1765EXPORT_SYMBOL(free_pages_exact); 1766 1767static unsigned int nr_free_zone_pages(int offset) 1768{ 1769 struct zoneref *z; 1770 struct zone *zone; 1771 1772 /* Just pick one node, since fallback list is circular */ 1773 unsigned int sum = 0; 1774 1775 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); 1776 1777 for_each_zone_zonelist(zone, z, zonelist, offset) { 1778 unsigned long size = zone->present_pages; 1779 unsigned long high = zone->pages_high; 1780 if (size > high) 1781 sum += size - high; 1782 } 1783 1784 return sum; 1785} 1786 1787/* 1788 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL 1789 */ 1790unsigned int nr_free_buffer_pages(void) 1791{ 1792 return nr_free_zone_pages(gfp_zone(GFP_USER)); 1793} 1794EXPORT_SYMBOL_GPL(nr_free_buffer_pages); 1795 1796/* 1797 * Amount of free RAM allocatable within all zones 1798 */ 1799unsigned int nr_free_pagecache_pages(void) 1800{ 1801 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); 1802} 1803 1804static inline void show_node(struct zone *zone) 1805{ 1806 if (NUMA_BUILD) 1807 printk("Node %d ", zone_to_nid(zone)); 1808} 1809 1810void si_meminfo(struct sysinfo *val) 1811{ 1812 val->totalram = totalram_pages; 1813 val->sharedram = 0; 1814 val->freeram = global_page_state(NR_FREE_PAGES); 1815 val->bufferram = nr_blockdev_pages(); 1816 val->totalhigh = totalhigh_pages; 1817 val->freehigh = nr_free_highpages(); 1818 val->mem_unit = PAGE_SIZE; 1819} 1820 1821EXPORT_SYMBOL(si_meminfo); 1822 1823#ifdef CONFIG_NUMA 1824void si_meminfo_node(struct sysinfo *val, int nid) 1825{ 1826 pg_data_t *pgdat = NODE_DATA(nid); 1827 1828 val->totalram = pgdat->node_present_pages; 1829 val->freeram = node_page_state(nid, NR_FREE_PAGES); 1830#ifdef CONFIG_HIGHMEM 1831 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; 1832 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], 1833 NR_FREE_PAGES); 1834#else 1835 val->totalhigh = 0; 1836 val->freehigh = 0; 1837#endif 1838 val->mem_unit = PAGE_SIZE; 1839} 1840#endif 1841 1842#define K(x) ((x) << (PAGE_SHIFT-10)) 1843 1844/* 1845 * Show free area list (used inside shift_scroll-lock stuff) 1846 * We also calculate the percentage fragmentation. We do this by counting the 1847 * memory on each free list with the exception of the first item on the list. 1848 */ 1849void show_free_areas(void) 1850{ 1851 int cpu; 1852 struct zone *zone; 1853 1854 for_each_zone(zone) { 1855 if (!populated_zone(zone)) 1856 continue; 1857 1858 show_node(zone); 1859 printk("%s per-cpu:\n", zone->name); 1860 1861 for_each_online_cpu(cpu) { 1862 struct per_cpu_pageset *pageset; 1863 1864 pageset = zone_pcp(zone, cpu); 1865 1866 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n", 1867 cpu, pageset->pcp.high, 1868 pageset->pcp.batch, pageset->pcp.count); 1869 } 1870 } 1871 1872 printk("Active_anon:%lu active_file:%lu inactive_anon:%lu\n" 1873 " inactive_file:%lu" 1874//TODO: check/adjust line lengths 1875#ifdef CONFIG_UNEVICTABLE_LRU 1876 " unevictable:%lu" 1877#endif 1878 " dirty:%lu writeback:%lu unstable:%lu\n" 1879 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n", 1880 global_page_state(NR_ACTIVE_ANON), 1881 global_page_state(NR_ACTIVE_FILE), 1882 global_page_state(NR_INACTIVE_ANON), 1883 global_page_state(NR_INACTIVE_FILE), 1884#ifdef CONFIG_UNEVICTABLE_LRU 1885 global_page_state(NR_UNEVICTABLE), 1886#endif 1887 global_page_state(NR_FILE_DIRTY), 1888 global_page_state(NR_WRITEBACK), 1889 global_page_state(NR_UNSTABLE_NFS), 1890 global_page_state(NR_FREE_PAGES), 1891 global_page_state(NR_SLAB_RECLAIMABLE) + 1892 global_page_state(NR_SLAB_UNRECLAIMABLE), 1893 global_page_state(NR_FILE_MAPPED), 1894 global_page_state(NR_PAGETABLE), 1895 global_page_state(NR_BOUNCE)); 1896 1897 for_each_zone(zone) { 1898 int i; 1899 1900 if (!populated_zone(zone)) 1901 continue; 1902 1903 show_node(zone); 1904 printk("%s" 1905 " free:%lukB" 1906 " min:%lukB" 1907 " low:%lukB" 1908 " high:%lukB" 1909 " active_anon:%lukB" 1910 " inactive_anon:%lukB" 1911 " active_file:%lukB" 1912 " inactive_file:%lukB" 1913#ifdef CONFIG_UNEVICTABLE_LRU 1914 " unevictable:%lukB" 1915#endif 1916 " present:%lukB" 1917 " pages_scanned:%lu" 1918 " all_unreclaimable? %s" 1919 "\n", 1920 zone->name, 1921 K(zone_page_state(zone, NR_FREE_PAGES)), 1922 K(zone->pages_min), 1923 K(zone->pages_low), 1924 K(zone->pages_high), 1925 K(zone_page_state(zone, NR_ACTIVE_ANON)), 1926 K(zone_page_state(zone, NR_INACTIVE_ANON)), 1927 K(zone_page_state(zone, NR_ACTIVE_FILE)), 1928 K(zone_page_state(zone, NR_INACTIVE_FILE)), 1929#ifdef CONFIG_UNEVICTABLE_LRU 1930 K(zone_page_state(zone, NR_UNEVICTABLE)), 1931#endif 1932 K(zone->present_pages), 1933 zone->pages_scanned, 1934 (zone_is_all_unreclaimable(zone) ? "yes" : "no") 1935 ); 1936 printk("lowmem_reserve[]:"); 1937 for (i = 0; i < MAX_NR_ZONES; i++) 1938 printk(" %lu", zone->lowmem_reserve[i]); 1939 printk("\n"); 1940 } 1941 1942 for_each_zone(zone) { 1943 unsigned long nr[MAX_ORDER], flags, order, total = 0; 1944 1945 if (!populated_zone(zone)) 1946 continue; 1947 1948 show_node(zone); 1949 printk("%s: ", zone->name); 1950 1951 spin_lock_irqsave(&zone->lock, flags); 1952 for (order = 0; order < MAX_ORDER; order++) { 1953 nr[order] = zone->free_area[order].nr_free; 1954 total += nr[order] << order; 1955 } 1956 spin_unlock_irqrestore(&zone->lock, flags); 1957 for (order = 0; order < MAX_ORDER; order++) 1958 printk("%lu*%lukB ", nr[order], K(1UL) << order); 1959 printk("= %lukB\n", K(total)); 1960 } 1961 1962 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES)); 1963 1964 show_swap_cache_info(); 1965} 1966 1967static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) 1968{ 1969 zoneref->zone = zone; 1970 zoneref->zone_idx = zone_idx(zone); 1971} 1972 1973/* 1974 * Builds allocation fallback zone lists. 1975 * 1976 * Add all populated zones of a node to the zonelist. 1977 */ 1978static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, 1979 int nr_zones, enum zone_type zone_type) 1980{ 1981 struct zone *zone; 1982 1983 BUG_ON(zone_type >= MAX_NR_ZONES); 1984 zone_type++; 1985 1986 do { 1987 zone_type--; 1988 zone = pgdat->node_zones + zone_type; 1989 if (populated_zone(zone)) { 1990 zoneref_set_zone(zone, 1991 &zonelist->_zonerefs[nr_zones++]); 1992 check_highest_zone(zone_type); 1993 } 1994 1995 } while (zone_type); 1996 return nr_zones; 1997} 1998 1999 2000/* 2001 * zonelist_order: 2002 * 0 = automatic detection of better ordering. 2003 * 1 = order by ([node] distance, -zonetype) 2004 * 2 = order by (-zonetype, [node] distance) 2005 * 2006 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create 2007 * the same zonelist. So only NUMA can configure this param. 2008 */ 2009#define ZONELIST_ORDER_DEFAULT 0 2010#define ZONELIST_ORDER_NODE 1 2011#define ZONELIST_ORDER_ZONE 2 2012 2013/* zonelist order in the kernel. 2014 * set_zonelist_order() will set this to NODE or ZONE. 2015 */ 2016static int current_zonelist_order = ZONELIST_ORDER_DEFAULT; 2017static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"}; 2018 2019 2020#ifdef CONFIG_NUMA 2021/* The value user specified ....changed by config */ 2022static int user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2023/* string for sysctl */ 2024#define NUMA_ZONELIST_ORDER_LEN 16 2025char numa_zonelist_order[16] = "default"; 2026 2027/* 2028 * interface for configure zonelist ordering. 2029 * command line option "numa_zonelist_order" 2030 * = "[dD]efault - default, automatic configuration. 2031 * = "[nN]ode - order by node locality, then by zone within node 2032 * = "[zZ]one - order by zone, then by locality within zone 2033 */ 2034 2035static int __parse_numa_zonelist_order(char *s) 2036{ 2037 if (*s == 'd' || *s == 'D') { 2038 user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2039 } else if (*s == 'n' || *s == 'N') { 2040 user_zonelist_order = ZONELIST_ORDER_NODE; 2041 } else if (*s == 'z' || *s == 'Z') { 2042 user_zonelist_order = ZONELIST_ORDER_ZONE; 2043 } else { 2044 printk(KERN_WARNING 2045 "Ignoring invalid numa_zonelist_order value: " 2046 "%s\n", s); 2047 return -EINVAL; 2048 } 2049 return 0; 2050} 2051 2052static __init int setup_numa_zonelist_order(char *s) 2053{ 2054 if (s) 2055 return __parse_numa_zonelist_order(s); 2056 return 0; 2057} 2058early_param("numa_zonelist_order", setup_numa_zonelist_order); 2059 2060/* 2061 * sysctl handler for numa_zonelist_order 2062 */ 2063int numa_zonelist_order_handler(ctl_table *table, int write, 2064 struct file *file, void __user *buffer, size_t *length, 2065 loff_t *ppos) 2066{ 2067 char saved_string[NUMA_ZONELIST_ORDER_LEN]; 2068 int ret; 2069 2070 if (write) 2071 strncpy(saved_string, (char*)table->data, 2072 NUMA_ZONELIST_ORDER_LEN); 2073 ret = proc_dostring(table, write, file, buffer, length, ppos); 2074 if (ret) 2075 return ret; 2076 if (write) { 2077 int oldval = user_zonelist_order; 2078 if (__parse_numa_zonelist_order((char*)table->data)) { 2079 /* 2080 * bogus value. restore saved string 2081 */ 2082 strncpy((char*)table->data, saved_string, 2083 NUMA_ZONELIST_ORDER_LEN); 2084 user_zonelist_order = oldval; 2085 } else if (oldval != user_zonelist_order) 2086 build_all_zonelists(); 2087 } 2088 return 0; 2089} 2090 2091 2092#define MAX_NODE_LOAD (num_online_nodes()) 2093static int node_load[MAX_NUMNODES]; 2094 2095/** 2096 * find_next_best_node - find the next node that should appear in a given node's fallback list 2097 * @node: node whose fallback list we're appending 2098 * @used_node_mask: nodemask_t of already used nodes 2099 * 2100 * We use a number of factors to determine which is the next node that should 2101 * appear on a given node's fallback list. The node should not have appeared 2102 * already in @node's fallback list, and it should be the next closest node 2103 * according to the distance array (which contains arbitrary distance values 2104 * from each node to each node in the system), and should also prefer nodes 2105 * with no CPUs, since presumably they'll have very little allocation pressure 2106 * on them otherwise. 2107 * It returns -1 if no node is found. 2108 */ 2109static int find_next_best_node(int node, nodemask_t *used_node_mask) 2110{ 2111 int n, val; 2112 int min_val = INT_MAX; 2113 int best_node = -1; 2114 node_to_cpumask_ptr(tmp, 0); 2115 2116 /* Use the local node if we haven't already */ 2117 if (!node_isset(node, *used_node_mask)) { 2118 node_set(node, *used_node_mask); 2119 return node; 2120 } 2121 2122 for_each_node_state(n, N_HIGH_MEMORY) { 2123 2124 /* Don't want a node to appear more than once */ 2125 if (node_isset(n, *used_node_mask)) 2126 continue; 2127 2128 /* Use the distance array to find the distance */ 2129 val = node_distance(node, n); 2130 2131 /* Penalize nodes under us ("prefer the next node") */ 2132 val += (n < node); 2133 2134 /* Give preference to headless and unused nodes */ 2135 node_to_cpumask_ptr_next(tmp, n); 2136 if (!cpus_empty(*tmp)) 2137 val += PENALTY_FOR_NODE_WITH_CPUS; 2138 2139 /* Slight preference for less loaded node */ 2140 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 2141 val += node_load[n]; 2142 2143 if (val < min_val) { 2144 min_val = val; 2145 best_node = n; 2146 } 2147 } 2148 2149 if (best_node >= 0) 2150 node_set(best_node, *used_node_mask); 2151 2152 return best_node; 2153} 2154 2155 2156/* 2157 * Build zonelists ordered by node and zones within node. 2158 * This results in maximum locality--normal zone overflows into local 2159 * DMA zone, if any--but risks exhausting DMA zone. 2160 */ 2161static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) 2162{ 2163 int j; 2164 struct zonelist *zonelist; 2165 2166 zonelist = &pgdat->node_zonelists[0]; 2167 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++) 2168 ; 2169 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2170 MAX_NR_ZONES - 1); 2171 zonelist->_zonerefs[j].zone = NULL; 2172 zonelist->_zonerefs[j].zone_idx = 0; 2173} 2174 2175/* 2176 * Build gfp_thisnode zonelists 2177 */ 2178static void build_thisnode_zonelists(pg_data_t *pgdat) 2179{ 2180 int j; 2181 struct zonelist *zonelist; 2182 2183 zonelist = &pgdat->node_zonelists[1]; 2184 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2185 zonelist->_zonerefs[j].zone = NULL; 2186 zonelist->_zonerefs[j].zone_idx = 0; 2187} 2188 2189/* 2190 * Build zonelists ordered by zone and nodes within zones. 2191 * This results in conserving DMA zone[s] until all Normal memory is 2192 * exhausted, but results in overflowing to remote node while memory 2193 * may still exist in local DMA zone. 2194 */ 2195static int node_order[MAX_NUMNODES]; 2196 2197static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) 2198{ 2199 int pos, j, node; 2200 int zone_type; /* needs to be signed */ 2201 struct zone *z; 2202 struct zonelist *zonelist; 2203 2204 zonelist = &pgdat->node_zonelists[0]; 2205 pos = 0; 2206 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) { 2207 for (j = 0; j < nr_nodes; j++) { 2208 node = node_order[j]; 2209 z = &NODE_DATA(node)->node_zones[zone_type]; 2210 if (populated_zone(z)) { 2211 zoneref_set_zone(z, 2212 &zonelist->_zonerefs[pos++]); 2213 check_highest_zone(zone_type); 2214 } 2215 } 2216 } 2217 zonelist->_zonerefs[pos].zone = NULL; 2218 zonelist->_zonerefs[pos].zone_idx = 0; 2219} 2220 2221static int default_zonelist_order(void) 2222{ 2223 int nid, zone_type; 2224 unsigned long low_kmem_size,total_size; 2225 struct zone *z; 2226 int average_size; 2227 /* 2228 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem. 2229 * If they are really small and used heavily, the system can fall 2230 * into OOM very easily. 2231 * This function detect ZONE_DMA/DMA32 size and confgigures zone order. 2232 */ 2233 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */ 2234 low_kmem_size = 0; 2235 total_size = 0; 2236 for_each_online_node(nid) { 2237 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2238 z = &NODE_DATA(nid)->node_zones[zone_type]; 2239 if (populated_zone(z)) { 2240 if (zone_type < ZONE_NORMAL) 2241 low_kmem_size += z->present_pages; 2242 total_size += z->present_pages; 2243 } 2244 } 2245 } 2246 if (!low_kmem_size || /* there are no DMA area. */ 2247 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */ 2248 return ZONELIST_ORDER_NODE; 2249 /* 2250 * look into each node's config. 2251 * If there is a node whose DMA/DMA32 memory is very big area on 2252 * local memory, NODE_ORDER may be suitable. 2253 */ 2254 average_size = total_size / 2255 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1); 2256 for_each_online_node(nid) { 2257 low_kmem_size = 0; 2258 total_size = 0; 2259 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2260 z = &NODE_DATA(nid)->node_zones[zone_type]; 2261 if (populated_zone(z)) { 2262 if (zone_type < ZONE_NORMAL) 2263 low_kmem_size += z->present_pages; 2264 total_size += z->present_pages; 2265 } 2266 } 2267 if (low_kmem_size && 2268 total_size > average_size && /* ignore small node */ 2269 low_kmem_size > total_size * 70/100) 2270 return ZONELIST_ORDER_NODE; 2271 } 2272 return ZONELIST_ORDER_ZONE; 2273} 2274 2275static void set_zonelist_order(void) 2276{ 2277 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT) 2278 current_zonelist_order = default_zonelist_order(); 2279 else 2280 current_zonelist_order = user_zonelist_order; 2281} 2282 2283static void build_zonelists(pg_data_t *pgdat) 2284{ 2285 int j, node, load; 2286 enum zone_type i; 2287 nodemask_t used_mask; 2288 int local_node, prev_node; 2289 struct zonelist *zonelist; 2290 int order = current_zonelist_order; 2291 2292 /* initialize zonelists */ 2293 for (i = 0; i < MAX_ZONELISTS; i++) { 2294 zonelist = pgdat->node_zonelists + i; 2295 zonelist->_zonerefs[0].zone = NULL; 2296 zonelist->_zonerefs[0].zone_idx = 0; 2297 } 2298 2299 /* NUMA-aware ordering of nodes */ 2300 local_node = pgdat->node_id; 2301 load = num_online_nodes(); 2302 prev_node = local_node; 2303 nodes_clear(used_mask); 2304 2305 memset(node_load, 0, sizeof(node_load)); 2306 memset(node_order, 0, sizeof(node_order)); 2307 j = 0; 2308 2309 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 2310 int distance = node_distance(local_node, node); 2311 2312 /* 2313 * If another node is sufficiently far away then it is better 2314 * to reclaim pages in a zone before going off node. 2315 */ 2316 if (distance > RECLAIM_DISTANCE) 2317 zone_reclaim_mode = 1; 2318 2319 /* 2320 * We don't want to pressure a particular node. 2321 * So adding penalty to the first node in same 2322 * distance group to make it round-robin. 2323 */ 2324 if (distance != node_distance(local_node, prev_node)) 2325 node_load[node] = load; 2326 2327 prev_node = node; 2328 load--; 2329 if (order == ZONELIST_ORDER_NODE) 2330 build_zonelists_in_node_order(pgdat, node); 2331 else 2332 node_order[j++] = node; /* remember order */ 2333 } 2334 2335 if (order == ZONELIST_ORDER_ZONE) { 2336 /* calculate node order -- i.e., DMA last! */ 2337 build_zonelists_in_zone_order(pgdat, j); 2338 } 2339 2340 build_thisnode_zonelists(pgdat); 2341} 2342 2343/* Construct the zonelist performance cache - see further mmzone.h */ 2344static void build_zonelist_cache(pg_data_t *pgdat) 2345{ 2346 struct zonelist *zonelist; 2347 struct zonelist_cache *zlc; 2348 struct zoneref *z; 2349 2350 zonelist = &pgdat->node_zonelists[0]; 2351 zonelist->zlcache_ptr = zlc = &zonelist->zlcache; 2352 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 2353 for (z = zonelist->_zonerefs; z->zone; z++) 2354 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z); 2355} 2356 2357 2358#else /* CONFIG_NUMA */ 2359 2360static void set_zonelist_order(void) 2361{ 2362 current_zonelist_order = ZONELIST_ORDER_ZONE; 2363} 2364 2365static void build_zonelists(pg_data_t *pgdat) 2366{ 2367 int node, local_node; 2368 enum zone_type j; 2369 struct zonelist *zonelist; 2370 2371 local_node = pgdat->node_id; 2372 2373 zonelist = &pgdat->node_zonelists[0]; 2374 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2375 2376 /* 2377 * Now we build the zonelist so that it contains the zones 2378 * of all the other nodes. 2379 * We don't want to pressure a particular node, so when 2380 * building the zones for node N, we make sure that the 2381 * zones coming right after the local ones are those from 2382 * node N+1 (modulo N) 2383 */ 2384 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 2385 if (!node_online(node)) 2386 continue; 2387 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2388 MAX_NR_ZONES - 1); 2389 } 2390 for (node = 0; node < local_node; node++) { 2391 if (!node_online(node)) 2392 continue; 2393 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2394 MAX_NR_ZONES - 1); 2395 } 2396 2397 zonelist->_zonerefs[j].zone = NULL; 2398 zonelist->_zonerefs[j].zone_idx = 0; 2399} 2400 2401/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ 2402static void build_zonelist_cache(pg_data_t *pgdat) 2403{ 2404 pgdat->node_zonelists[0].zlcache_ptr = NULL; 2405} 2406 2407#endif /* CONFIG_NUMA */ 2408 2409/* return values int ....just for stop_machine() */ 2410static int __build_all_zonelists(void *dummy) 2411{ 2412 int nid; 2413 2414 for_each_online_node(nid) { 2415 pg_data_t *pgdat = NODE_DATA(nid); 2416 2417 build_zonelists(pgdat); 2418 build_zonelist_cache(pgdat); 2419 } 2420 return 0; 2421} 2422 2423void build_all_zonelists(void) 2424{ 2425 set_zonelist_order(); 2426 2427 if (system_state == SYSTEM_BOOTING) { 2428 __build_all_zonelists(NULL); 2429 mminit_verify_zonelist(); 2430 cpuset_init_current_mems_allowed(); 2431 } else { 2432 /* we have to stop all cpus to guarantee there is no user 2433 of zonelist */ 2434 stop_machine(__build_all_zonelists, NULL, NULL); 2435 /* cpuset refresh routine should be here */ 2436 } 2437 vm_total_pages = nr_free_pagecache_pages(); 2438 /* 2439 * Disable grouping by mobility if the number of pages in the 2440 * system is too low to allow the mechanism to work. It would be 2441 * more accurate, but expensive to check per-zone. This check is 2442 * made on memory-hotadd so a system can start with mobility 2443 * disabled and enable it later 2444 */ 2445 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) 2446 page_group_by_mobility_disabled = 1; 2447 else 2448 page_group_by_mobility_disabled = 0; 2449 2450 printk("Built %i zonelists in %s order, mobility grouping %s. " 2451 "Total pages: %ld\n", 2452 num_online_nodes(), 2453 zonelist_order_name[current_zonelist_order], 2454 page_group_by_mobility_disabled ? "off" : "on", 2455 vm_total_pages); 2456#ifdef CONFIG_NUMA 2457 printk("Policy zone: %s\n", zone_names[policy_zone]); 2458#endif 2459} 2460 2461/* 2462 * Helper functions to size the waitqueue hash table. 2463 * Essentially these want to choose hash table sizes sufficiently 2464 * large so that collisions trying to wait on pages are rare. 2465 * But in fact, the number of active page waitqueues on typical 2466 * systems is ridiculously low, less than 200. So this is even 2467 * conservative, even though it seems large. 2468 * 2469 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 2470 * waitqueues, i.e. the size of the waitq table given the number of pages. 2471 */ 2472#define PAGES_PER_WAITQUEUE 256 2473 2474#ifndef CONFIG_MEMORY_HOTPLUG 2475static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2476{ 2477 unsigned long size = 1; 2478 2479 pages /= PAGES_PER_WAITQUEUE; 2480 2481 while (size < pages) 2482 size <<= 1; 2483 2484 /* 2485 * Once we have dozens or even hundreds of threads sleeping 2486 * on IO we've got bigger problems than wait queue collision. 2487 * Limit the size of the wait table to a reasonable size. 2488 */ 2489 size = min(size, 4096UL); 2490 2491 return max(size, 4UL); 2492} 2493#else 2494/* 2495 * A zone's size might be changed by hot-add, so it is not possible to determine 2496 * a suitable size for its wait_table. So we use the maximum size now. 2497 * 2498 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: 2499 * 2500 * i386 (preemption config) : 4096 x 16 = 64Kbyte. 2501 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. 2502 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. 2503 * 2504 * The maximum entries are prepared when a zone's memory is (512K + 256) pages 2505 * or more by the traditional way. (See above). It equals: 2506 * 2507 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. 2508 * ia64(16K page size) : = ( 8G + 4M)byte. 2509 * powerpc (64K page size) : = (32G +16M)byte. 2510 */ 2511static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2512{ 2513 return 4096UL; 2514} 2515#endif 2516 2517/* 2518 * This is an integer logarithm so that shifts can be used later 2519 * to extract the more random high bits from the multiplicative 2520 * hash function before the remainder is taken. 2521 */ 2522static inline unsigned long wait_table_bits(unsigned long size) 2523{ 2524 return ffz(~size); 2525} 2526 2527#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) 2528 2529/* 2530 * Mark a number of pageblocks as MIGRATE_RESERVE. The number 2531 * of blocks reserved is based on zone->pages_min. The memory within the 2532 * reserve will tend to store contiguous free pages. Setting min_free_kbytes 2533 * higher will lead to a bigger reserve which will get freed as contiguous 2534 * blocks as reclaim kicks in 2535 */ 2536static void setup_zone_migrate_reserve(struct zone *zone) 2537{ 2538 unsigned long start_pfn, pfn, end_pfn; 2539 struct page *page; 2540 unsigned long reserve, block_migratetype; 2541 2542 /* Get the start pfn, end pfn and the number of blocks to reserve */ 2543 start_pfn = zone->zone_start_pfn; 2544 end_pfn = start_pfn + zone->spanned_pages; 2545 reserve = roundup(zone->pages_min, pageblock_nr_pages) >> 2546 pageblock_order; 2547 2548 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 2549 if (!pfn_valid(pfn)) 2550 continue; 2551 page = pfn_to_page(pfn); 2552 2553 /* Watch out for overlapping nodes */ 2554 if (page_to_nid(page) != zone_to_nid(zone)) 2555 continue; 2556 2557 /* Blocks with reserved pages will never free, skip them. */ 2558 if (PageReserved(page)) 2559 continue; 2560 2561 block_migratetype = get_pageblock_migratetype(page); 2562 2563 /* If this block is reserved, account for it */ 2564 if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) { 2565 reserve--; 2566 continue; 2567 } 2568 2569 /* Suitable for reserving if this block is movable */ 2570 if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) { 2571 set_pageblock_migratetype(page, MIGRATE_RESERVE); 2572 move_freepages_block(zone, page, MIGRATE_RESERVE); 2573 reserve--; 2574 continue; 2575 } 2576 2577 /* 2578 * If the reserve is met and this is a previous reserved block, 2579 * take it back 2580 */ 2581 if (block_migratetype == MIGRATE_RESERVE) { 2582 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 2583 move_freepages_block(zone, page, MIGRATE_MOVABLE); 2584 } 2585 } 2586} 2587 2588/* 2589 * Initially all pages are reserved - free ones are freed 2590 * up by free_all_bootmem() once the early boot process is 2591 * done. Non-atomic initialization, single-pass. 2592 */ 2593void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 2594 unsigned long start_pfn, enum memmap_context context) 2595{ 2596 struct page *page; 2597 unsigned long end_pfn = start_pfn + size; 2598 unsigned long pfn; 2599 struct zone *z; 2600 2601 z = &NODE_DATA(nid)->node_zones[zone]; 2602 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 2603 /* 2604 * There can be holes in boot-time mem_map[]s 2605 * handed to this function. They do not 2606 * exist on hotplugged memory. 2607 */ 2608 if (context == MEMMAP_EARLY) { 2609 if (!early_pfn_valid(pfn)) 2610 continue; 2611 if (!early_pfn_in_nid(pfn, nid)) 2612 continue; 2613 } 2614 page = pfn_to_page(pfn); 2615 set_page_links(page, zone, nid, pfn); 2616 mminit_verify_page_links(page, zone, nid, pfn); 2617 init_page_count(page); 2618 reset_page_mapcount(page); 2619 SetPageReserved(page); 2620 /* 2621 * Mark the block movable so that blocks are reserved for 2622 * movable at startup. This will force kernel allocations 2623 * to reserve their blocks rather than leaking throughout 2624 * the address space during boot when many long-lived 2625 * kernel allocations are made. Later some blocks near 2626 * the start are marked MIGRATE_RESERVE by 2627 * setup_zone_migrate_reserve() 2628 * 2629 * bitmap is created for zone's valid pfn range. but memmap 2630 * can be created for invalid pages (for alignment) 2631 * check here not to call set_pageblock_migratetype() against 2632 * pfn out of zone. 2633 */ 2634 if ((z->zone_start_pfn <= pfn) 2635 && (pfn < z->zone_start_pfn + z->spanned_pages) 2636 && !(pfn & (pageblock_nr_pages - 1))) 2637 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 2638 2639 INIT_LIST_HEAD(&page->lru); 2640#ifdef WANT_PAGE_VIRTUAL 2641 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 2642 if (!is_highmem_idx(zone)) 2643 set_page_address(page, __va(pfn << PAGE_SHIFT)); 2644#endif 2645 } 2646} 2647 2648static void __meminit zone_init_free_lists(struct zone *zone) 2649{ 2650 int order, t; 2651 for_each_migratetype_order(order, t) { 2652 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); 2653 zone->free_area[order].nr_free = 0; 2654 } 2655} 2656 2657#ifndef __HAVE_ARCH_MEMMAP_INIT 2658#define memmap_init(size, nid, zone, start_pfn) \ 2659 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) 2660#endif 2661 2662static int zone_batchsize(struct zone *zone) 2663{ 2664 int batch; 2665 2666 /* 2667 * The per-cpu-pages pools are set to around 1000th of the 2668 * size of the zone. But no more than 1/2 of a meg. 2669 * 2670 * OK, so we don't know how big the cache is. So guess. 2671 */ 2672 batch = zone->present_pages / 1024; 2673 if (batch * PAGE_SIZE > 512 * 1024) 2674 batch = (512 * 1024) / PAGE_SIZE; 2675 batch /= 4; /* We effectively *= 4 below */ 2676 if (batch < 1) 2677 batch = 1; 2678 2679 /* 2680 * Clamp the batch to a 2^n - 1 value. Having a power 2681 * of 2 value was found to be more likely to have 2682 * suboptimal cache aliasing properties in some cases. 2683 * 2684 * For example if 2 tasks are alternately allocating 2685 * batches of pages, one task can end up with a lot 2686 * of pages of one half of the possible page colors 2687 * and the other with pages of the other colors. 2688 */ 2689 batch = (1 << (fls(batch + batch/2)-1)) - 1; 2690 2691 return batch; 2692} 2693 2694static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 2695{ 2696 struct per_cpu_pages *pcp; 2697 2698 memset(p, 0, sizeof(*p)); 2699 2700 pcp = &p->pcp; 2701 pcp->count = 0; 2702 pcp->high = 6 * batch; 2703 pcp->batch = max(1UL, 1 * batch); 2704 INIT_LIST_HEAD(&pcp->list); 2705} 2706 2707/* 2708 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist 2709 * to the value high for the pageset p. 2710 */ 2711 2712static void setup_pagelist_highmark(struct per_cpu_pageset *p, 2713 unsigned long high) 2714{ 2715 struct per_cpu_pages *pcp; 2716 2717 pcp = &p->pcp; 2718 pcp->high = high; 2719 pcp->batch = max(1UL, high/4); 2720 if ((high/4) > (PAGE_SHIFT * 8)) 2721 pcp->batch = PAGE_SHIFT * 8; 2722} 2723 2724 2725#ifdef CONFIG_NUMA 2726/* 2727 * Boot pageset table. One per cpu which is going to be used for all 2728 * zones and all nodes. The parameters will be set in such a way 2729 * that an item put on a list will immediately be handed over to 2730 * the buddy list. This is safe since pageset manipulation is done 2731 * with interrupts disabled. 2732 * 2733 * Some NUMA counter updates may also be caught by the boot pagesets. 2734 * 2735 * The boot_pagesets must be kept even after bootup is complete for 2736 * unused processors and/or zones. They do play a role for bootstrapping 2737 * hotplugged processors. 2738 * 2739 * zoneinfo_show() and maybe other functions do 2740 * not check if the processor is online before following the pageset pointer. 2741 * Other parts of the kernel may not check if the zone is available. 2742 */ 2743static struct per_cpu_pageset boot_pageset[NR_CPUS]; 2744 2745/* 2746 * Dynamically allocate memory for the 2747 * per cpu pageset array in struct zone. 2748 */ 2749static int __cpuinit process_zones(int cpu) 2750{ 2751 struct zone *zone, *dzone; 2752 int node = cpu_to_node(cpu); 2753 2754 node_set_state(node, N_CPU); /* this node has a cpu */ 2755 2756 for_each_zone(zone) { 2757 2758 if (!populated_zone(zone)) 2759 continue; 2760 2761 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset), 2762 GFP_KERNEL, node); 2763 if (!zone_pcp(zone, cpu)) 2764 goto bad; 2765 2766 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone)); 2767 2768 if (percpu_pagelist_fraction) 2769 setup_pagelist_highmark(zone_pcp(zone, cpu), 2770 (zone->present_pages / percpu_pagelist_fraction)); 2771 } 2772 2773 return 0; 2774bad: 2775 for_each_zone(dzone) { 2776 if (!populated_zone(dzone)) 2777 continue; 2778 if (dzone == zone) 2779 break; 2780 kfree(zone_pcp(dzone, cpu)); 2781 zone_pcp(dzone, cpu) = NULL; 2782 } 2783 return -ENOMEM; 2784} 2785 2786static inline void free_zone_pagesets(int cpu) 2787{ 2788 struct zone *zone; 2789 2790 for_each_zone(zone) { 2791 struct per_cpu_pageset *pset = zone_pcp(zone, cpu); 2792 2793 /* Free per_cpu_pageset if it is slab allocated */ 2794 if (pset != &boot_pageset[cpu]) 2795 kfree(pset); 2796 zone_pcp(zone, cpu) = NULL; 2797 } 2798} 2799 2800static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb, 2801 unsigned long action, 2802 void *hcpu) 2803{ 2804 int cpu = (long)hcpu; 2805 int ret = NOTIFY_OK; 2806 2807 switch (action) { 2808 case CPU_UP_PREPARE: 2809 case CPU_UP_PREPARE_FROZEN: 2810 if (process_zones(cpu)) 2811 ret = NOTIFY_BAD; 2812 break; 2813 case CPU_UP_CANCELED: 2814 case CPU_UP_CANCELED_FROZEN: 2815 case CPU_DEAD: 2816 case CPU_DEAD_FROZEN: 2817 free_zone_pagesets(cpu); 2818 break; 2819 default: 2820 break; 2821 } 2822 return ret; 2823} 2824 2825static struct notifier_block __cpuinitdata pageset_notifier = 2826 { &pageset_cpuup_callback, NULL, 0 }; 2827 2828void __init setup_per_cpu_pageset(void) 2829{ 2830 int err; 2831 2832 /* Initialize per_cpu_pageset for cpu 0. 2833 * A cpuup callback will do this for every cpu 2834 * as it comes online 2835 */ 2836 err = process_zones(smp_processor_id()); 2837 BUG_ON(err); 2838 register_cpu_notifier(&pageset_notifier); 2839} 2840 2841#endif 2842 2843static noinline __init_refok 2844int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 2845{ 2846 int i; 2847 struct pglist_data *pgdat = zone->zone_pgdat; 2848 size_t alloc_size; 2849 2850 /* 2851 * The per-page waitqueue mechanism uses hashed waitqueues 2852 * per zone. 2853 */ 2854 zone->wait_table_hash_nr_entries = 2855 wait_table_hash_nr_entries(zone_size_pages); 2856 zone->wait_table_bits = 2857 wait_table_bits(zone->wait_table_hash_nr_entries); 2858 alloc_size = zone->wait_table_hash_nr_entries 2859 * sizeof(wait_queue_head_t); 2860 2861 if (!slab_is_available()) { 2862 zone->wait_table = (wait_queue_head_t *) 2863 alloc_bootmem_node(pgdat, alloc_size); 2864 } else { 2865 /* 2866 * This case means that a zone whose size was 0 gets new memory 2867 * via memory hot-add. 2868 * But it may be the case that a new node was hot-added. In 2869 * this case vmalloc() will not be able to use this new node's 2870 * memory - this wait_table must be initialized to use this new 2871 * node itself as well. 2872 * To use this new node's memory, further consideration will be 2873 * necessary. 2874 */ 2875 zone->wait_table = vmalloc(alloc_size); 2876 } 2877 if (!zone->wait_table) 2878 return -ENOMEM; 2879 2880 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i) 2881 init_waitqueue_head(zone->wait_table + i); 2882 2883 return 0; 2884} 2885 2886static __meminit void zone_pcp_init(struct zone *zone) 2887{ 2888 int cpu; 2889 unsigned long batch = zone_batchsize(zone); 2890 2891 for (cpu = 0; cpu < NR_CPUS; cpu++) { 2892#ifdef CONFIG_NUMA 2893 /* Early boot. Slab allocator not functional yet */ 2894 zone_pcp(zone, cpu) = &boot_pageset[cpu]; 2895 setup_pageset(&boot_pageset[cpu],0); 2896#else 2897 setup_pageset(zone_pcp(zone,cpu), batch); 2898#endif 2899 } 2900 if (zone->present_pages) 2901 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", 2902 zone->name, zone->present_pages, batch); 2903} 2904 2905__meminit int init_currently_empty_zone(struct zone *zone, 2906 unsigned long zone_start_pfn, 2907 unsigned long size, 2908 enum memmap_context context) 2909{ 2910 struct pglist_data *pgdat = zone->zone_pgdat; 2911 int ret; 2912 ret = zone_wait_table_init(zone, size); 2913 if (ret) 2914 return ret; 2915 pgdat->nr_zones = zone_idx(zone) + 1; 2916 2917 zone->zone_start_pfn = zone_start_pfn; 2918 2919 mminit_dprintk(MMINIT_TRACE, "memmap_init", 2920 "Initialising map node %d zone %lu pfns %lu -> %lu\n", 2921 pgdat->node_id, 2922 (unsigned long)zone_idx(zone), 2923 zone_start_pfn, (zone_start_pfn + size)); 2924 2925 zone_init_free_lists(zone); 2926 2927 return 0; 2928} 2929 2930#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 2931/* 2932 * Basic iterator support. Return the first range of PFNs for a node 2933 * Note: nid == MAX_NUMNODES returns first region regardless of node 2934 */ 2935static int __meminit first_active_region_index_in_nid(int nid) 2936{ 2937 int i; 2938 2939 for (i = 0; i < nr_nodemap_entries; i++) 2940 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid) 2941 return i; 2942 2943 return -1; 2944} 2945 2946/* 2947 * Basic iterator support. Return the next active range of PFNs for a node 2948 * Note: nid == MAX_NUMNODES returns next region regardless of node 2949 */ 2950static int __meminit next_active_region_index_in_nid(int index, int nid) 2951{ 2952 for (index = index + 1; index < nr_nodemap_entries; index++) 2953 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid) 2954 return index; 2955 2956 return -1; 2957} 2958 2959#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID 2960/* 2961 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. 2962 * Architectures may implement their own version but if add_active_range() 2963 * was used and there are no special requirements, this is a convenient 2964 * alternative 2965 */ 2966int __meminit early_pfn_to_nid(unsigned long pfn) 2967{ 2968 int i; 2969 2970 for (i = 0; i < nr_nodemap_entries; i++) { 2971 unsigned long start_pfn = early_node_map[i].start_pfn; 2972 unsigned long end_pfn = early_node_map[i].end_pfn; 2973 2974 if (start_pfn <= pfn && pfn < end_pfn) 2975 return early_node_map[i].nid; 2976 } 2977 2978 return 0; 2979} 2980#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ 2981 2982/* Basic iterator support to walk early_node_map[] */ 2983#define for_each_active_range_index_in_nid(i, nid) \ 2984 for (i = first_active_region_index_in_nid(nid); i != -1; \ 2985 i = next_active_region_index_in_nid(i, nid)) 2986 2987/** 2988 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range 2989 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. 2990 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node 2991 * 2992 * If an architecture guarantees that all ranges registered with 2993 * add_active_ranges() contain no holes and may be freed, this 2994 * this function may be used instead of calling free_bootmem() manually. 2995 */ 2996void __init free_bootmem_with_active_regions(int nid, 2997 unsigned long max_low_pfn) 2998{ 2999 int i; 3000 3001 for_each_active_range_index_in_nid(i, nid) { 3002 unsigned long size_pages = 0; 3003 unsigned long end_pfn = early_node_map[i].end_pfn; 3004 3005 if (early_node_map[i].start_pfn >= max_low_pfn) 3006 continue; 3007 3008 if (end_pfn > max_low_pfn) 3009 end_pfn = max_low_pfn; 3010 3011 size_pages = end_pfn - early_node_map[i].start_pfn; 3012 free_bootmem_node(NODE_DATA(early_node_map[i].nid), 3013 PFN_PHYS(early_node_map[i].start_pfn), 3014 size_pages << PAGE_SHIFT); 3015 } 3016} 3017 3018void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data) 3019{ 3020 int i; 3021 int ret; 3022 3023 for_each_active_range_index_in_nid(i, nid) { 3024 ret = work_fn(early_node_map[i].start_pfn, 3025 early_node_map[i].end_pfn, data); 3026 if (ret) 3027 break; 3028 } 3029} 3030/** 3031 * sparse_memory_present_with_active_regions - Call memory_present for each active range 3032 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. 3033 * 3034 * If an architecture guarantees that all ranges registered with 3035 * add_active_ranges() contain no holes and may be freed, this 3036 * function may be used instead of calling memory_present() manually. 3037 */ 3038void __init sparse_memory_present_with_active_regions(int nid) 3039{ 3040 int i; 3041 3042 for_each_active_range_index_in_nid(i, nid) 3043 memory_present(early_node_map[i].nid, 3044 early_node_map[i].start_pfn, 3045 early_node_map[i].end_pfn); 3046} 3047 3048/** 3049 * push_node_boundaries - Push node boundaries to at least the requested boundary 3050 * @nid: The nid of the node to push the boundary for 3051 * @start_pfn: The start pfn of the node 3052 * @end_pfn: The end pfn of the node 3053 * 3054 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd 3055 * time. Specifically, on x86_64, SRAT will report ranges that can potentially 3056 * be hotplugged even though no physical memory exists. This function allows 3057 * an arch to push out the node boundaries so mem_map is allocated that can 3058 * be used later. 3059 */ 3060#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE 3061void __init push_node_boundaries(unsigned int nid, 3062 unsigned long start_pfn, unsigned long end_pfn) 3063{ 3064 mminit_dprintk(MMINIT_TRACE, "zoneboundary", 3065 "Entering push_node_boundaries(%u, %lu, %lu)\n", 3066 nid, start_pfn, end_pfn); 3067 3068 /* Initialise the boundary for this node if necessary */ 3069 if (node_boundary_end_pfn[nid] == 0) 3070 node_boundary_start_pfn[nid] = -1UL; 3071 3072 /* Update the boundaries */ 3073 if (node_boundary_start_pfn[nid] > start_pfn) 3074 node_boundary_start_pfn[nid] = start_pfn; 3075 if (node_boundary_end_pfn[nid] < end_pfn) 3076 node_boundary_end_pfn[nid] = end_pfn; 3077} 3078 3079/* If necessary, push the node boundary out for reserve hotadd */ 3080static void __meminit account_node_boundary(unsigned int nid, 3081 unsigned long *start_pfn, unsigned long *end_pfn) 3082{ 3083 mminit_dprintk(MMINIT_TRACE, "zoneboundary", 3084 "Entering account_node_boundary(%u, %lu, %lu)\n", 3085 nid, *start_pfn, *end_pfn); 3086 3087 /* Return if boundary information has not been provided */ 3088 if (node_boundary_end_pfn[nid] == 0) 3089 return; 3090 3091 /* Check the boundaries and update if necessary */ 3092 if (node_boundary_start_pfn[nid] < *start_pfn) 3093 *start_pfn = node_boundary_start_pfn[nid]; 3094 if (node_boundary_end_pfn[nid] > *end_pfn) 3095 *end_pfn = node_boundary_end_pfn[nid]; 3096} 3097#else 3098void __init push_node_boundaries(unsigned int nid, 3099 unsigned long start_pfn, unsigned long end_pfn) {} 3100 3101static void __meminit account_node_boundary(unsigned int nid, 3102 unsigned long *start_pfn, unsigned long *end_pfn) {} 3103#endif 3104 3105 3106/** 3107 * get_pfn_range_for_nid - Return the start and end page frames for a node 3108 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. 3109 * @start_pfn: Passed by reference. On return, it will have the node start_pfn. 3110 * @end_pfn: Passed by reference. On return, it will have the node end_pfn. 3111 * 3112 * It returns the start and end page frame of a node based on information 3113 * provided by an arch calling add_active_range(). If called for a node 3114 * with no available memory, a warning is printed and the start and end 3115 * PFNs will be 0. 3116 */ 3117void __meminit get_pfn_range_for_nid(unsigned int nid, 3118 unsigned long *start_pfn, unsigned long *end_pfn) 3119{ 3120 int i; 3121 *start_pfn = -1UL; 3122 *end_pfn = 0; 3123 3124 for_each_active_range_index_in_nid(i, nid) { 3125 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn); 3126 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn); 3127 } 3128 3129 if (*start_pfn == -1UL) 3130 *start_pfn = 0; 3131 3132 /* Push the node boundaries out if requested */ 3133 account_node_boundary(nid, start_pfn, end_pfn); 3134} 3135 3136/* 3137 * This finds a zone that can be used for ZONE_MOVABLE pages. The 3138 * assumption is made that zones within a node are ordered in monotonic 3139 * increasing memory addresses so that the "highest" populated zone is used 3140 */ 3141static void __init find_usable_zone_for_movable(void) 3142{ 3143 int zone_index; 3144 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { 3145 if (zone_index == ZONE_MOVABLE) 3146 continue; 3147 3148 if (arch_zone_highest_possible_pfn[zone_index] > 3149 arch_zone_lowest_possible_pfn[zone_index]) 3150 break; 3151 } 3152 3153 VM_BUG_ON(zone_index == -1); 3154 movable_zone = zone_index; 3155} 3156 3157/* 3158 * The zone ranges provided by the architecture do not include ZONE_MOVABLE 3159 * because it is sized independant of architecture. Unlike the other zones, 3160 * the starting point for ZONE_MOVABLE is not fixed. It may be different 3161 * in each node depending on the size of each node and how evenly kernelcore 3162 * is distributed. This helper function adjusts the zone ranges 3163 * provided by the architecture for a given node by using the end of the 3164 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that 3165 * zones within a node are in order of monotonic increases memory addresses 3166 */ 3167static void __meminit adjust_zone_range_for_zone_movable(int nid, 3168 unsigned long zone_type, 3169 unsigned long node_start_pfn, 3170 unsigned long node_end_pfn, 3171 unsigned long *zone_start_pfn, 3172 unsigned long *zone_end_pfn) 3173{ 3174 /* Only adjust if ZONE_MOVABLE is on this node */ 3175 if (zone_movable_pfn[nid]) { 3176 /* Size ZONE_MOVABLE */ 3177 if (zone_type == ZONE_MOVABLE) { 3178 *zone_start_pfn = zone_movable_pfn[nid]; 3179 *zone_end_pfn = min(node_end_pfn, 3180 arch_zone_highest_possible_pfn[movable_zone]); 3181 3182 /* Adjust for ZONE_MOVABLE starting within this range */ 3183 } else if (*zone_start_pfn < zone_movable_pfn[nid] && 3184 *zone_end_pfn > zone_movable_pfn[nid]) { 3185 *zone_end_pfn = zone_movable_pfn[nid]; 3186 3187 /* Check if this whole range is within ZONE_MOVABLE */ 3188 } else if (*zone_start_pfn >= zone_movable_pfn[nid]) 3189 *zone_start_pfn = *zone_end_pfn; 3190 } 3191} 3192 3193/* 3194 * Return the number of pages a zone spans in a node, including holes 3195 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() 3196 */ 3197static unsigned long __meminit zone_spanned_pages_in_node(int nid, 3198 unsigned long zone_type, 3199 unsigned long *ignored) 3200{ 3201 unsigned long node_start_pfn, node_end_pfn; 3202 unsigned long zone_start_pfn, zone_end_pfn; 3203 3204 /* Get the start and end of the node and zone */ 3205 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3206 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; 3207 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; 3208 adjust_zone_range_for_zone_movable(nid, zone_type, 3209 node_start_pfn, node_end_pfn, 3210 &zone_start_pfn, &zone_end_pfn); 3211 3212 /* Check that this node has pages within the zone's required range */ 3213 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) 3214 return 0; 3215 3216 /* Move the zone boundaries inside the node if necessary */ 3217 zone_end_pfn = min(zone_end_pfn, node_end_pfn); 3218 zone_start_pfn = max(zone_start_pfn, node_start_pfn); 3219 3220 /* Return the spanned pages */ 3221 return zone_end_pfn - zone_start_pfn; 3222} 3223 3224/* 3225 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, 3226 * then all holes in the requested range will be accounted for. 3227 */ 3228static unsigned long __meminit __absent_pages_in_range(int nid, 3229 unsigned long range_start_pfn, 3230 unsigned long range_end_pfn) 3231{ 3232 int i = 0; 3233 unsigned long prev_end_pfn = 0, hole_pages = 0; 3234 unsigned long start_pfn; 3235 3236 /* Find the end_pfn of the first active range of pfns in the node */ 3237 i = first_active_region_index_in_nid(nid); 3238 if (i == -1) 3239 return 0; 3240 3241 prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 3242 3243 /* Account for ranges before physical memory on this node */ 3244 if (early_node_map[i].start_pfn > range_start_pfn) 3245 hole_pages = prev_end_pfn - range_start_pfn; 3246 3247 /* Find all holes for the zone within the node */ 3248 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) { 3249 3250 /* No need to continue if prev_end_pfn is outside the zone */ 3251 if (prev_end_pfn >= range_end_pfn) 3252 break; 3253 3254 /* Make sure the end of the zone is not within the hole */ 3255 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 3256 prev_end_pfn = max(prev_end_pfn, range_start_pfn); 3257 3258 /* Update the hole size cound and move on */ 3259 if (start_pfn > range_start_pfn) { 3260 BUG_ON(prev_end_pfn > start_pfn); 3261 hole_pages += start_pfn - prev_end_pfn; 3262 } 3263 prev_end_pfn = early_node_map[i].end_pfn; 3264 } 3265 3266 /* Account for ranges past physical memory on this node */ 3267 if (range_end_pfn > prev_end_pfn) 3268 hole_pages += range_end_pfn - 3269 max(range_start_pfn, prev_end_pfn); 3270 3271 return hole_pages; 3272} 3273 3274/** 3275 * absent_pages_in_range - Return number of page frames in holes within a range 3276 * @start_pfn: The start PFN to start searching for holes 3277 * @end_pfn: The end PFN to stop searching for holes 3278 * 3279 * It returns the number of pages frames in memory holes within a range. 3280 */ 3281unsigned long __init absent_pages_in_range(unsigned long start_pfn, 3282 unsigned long end_pfn) 3283{ 3284 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); 3285} 3286 3287/* Return the number of page frames in holes in a zone on a node */ 3288static unsigned long __meminit zone_absent_pages_in_node(int nid, 3289 unsigned long zone_type, 3290 unsigned long *ignored) 3291{ 3292 unsigned long node_start_pfn, node_end_pfn; 3293 unsigned long zone_start_pfn, zone_end_pfn; 3294 3295 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3296 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type], 3297 node_start_pfn); 3298 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type], 3299 node_end_pfn); 3300 3301 adjust_zone_range_for_zone_movable(nid, zone_type, 3302 node_start_pfn, node_end_pfn, 3303 &zone_start_pfn, &zone_end_pfn); 3304 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); 3305} 3306 3307#else 3308static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, 3309 unsigned long zone_type, 3310 unsigned long *zones_size) 3311{ 3312 return zones_size[zone_type]; 3313} 3314 3315static inline unsigned long __meminit zone_absent_pages_in_node(int nid, 3316 unsigned long zone_type, 3317 unsigned long *zholes_size) 3318{ 3319 if (!zholes_size) 3320 return 0; 3321 3322 return zholes_size[zone_type]; 3323} 3324 3325#endif 3326 3327static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, 3328 unsigned long *zones_size, unsigned long *zholes_size) 3329{ 3330 unsigned long realtotalpages, totalpages = 0; 3331 enum zone_type i; 3332 3333 for (i = 0; i < MAX_NR_ZONES; i++) 3334 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i, 3335 zones_size); 3336 pgdat->node_spanned_pages = totalpages; 3337 3338 realtotalpages = totalpages; 3339 for (i = 0; i < MAX_NR_ZONES; i++) 3340 realtotalpages -= 3341 zone_absent_pages_in_node(pgdat->node_id, i, 3342 zholes_size); 3343 pgdat->node_present_pages = realtotalpages; 3344 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, 3345 realtotalpages); 3346} 3347 3348#ifndef CONFIG_SPARSEMEM 3349/* 3350 * Calculate the size of the zone->blockflags rounded to an unsigned long 3351 * Start by making sure zonesize is a multiple of pageblock_order by rounding 3352 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally 3353 * round what is now in bits to nearest long in bits, then return it in 3354 * bytes. 3355 */ 3356static unsigned long __init usemap_size(unsigned long zonesize) 3357{ 3358 unsigned long usemapsize; 3359 3360 usemapsize = roundup(zonesize, pageblock_nr_pages); 3361 usemapsize = usemapsize >> pageblock_order; 3362 usemapsize *= NR_PAGEBLOCK_BITS; 3363 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); 3364 3365 return usemapsize / 8; 3366} 3367 3368static void __init setup_usemap(struct pglist_data *pgdat, 3369 struct zone *zone, unsigned long zonesize) 3370{ 3371 unsigned long usemapsize = usemap_size(zonesize); 3372 zone->pageblock_flags = NULL; 3373 if (usemapsize) { 3374 zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize); 3375 memset(zone->pageblock_flags, 0, usemapsize); 3376 } 3377} 3378#else 3379static void inline setup_usemap(struct pglist_data *pgdat, 3380 struct zone *zone, unsigned long zonesize) {} 3381#endif /* CONFIG_SPARSEMEM */ 3382 3383#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 3384 3385/* Return a sensible default order for the pageblock size. */ 3386static inline int pageblock_default_order(void) 3387{ 3388 if (HPAGE_SHIFT > PAGE_SHIFT) 3389 return HUGETLB_PAGE_ORDER; 3390 3391 return MAX_ORDER-1; 3392} 3393 3394/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ 3395static inline void __init set_pageblock_order(unsigned int order) 3396{ 3397 /* Check that pageblock_nr_pages has not already been setup */ 3398 if (pageblock_order) 3399 return; 3400 3401 /* 3402 * Assume the largest contiguous order of interest is a huge page. 3403 * This value may be variable depending on boot parameters on IA64 3404 */ 3405 pageblock_order = order; 3406} 3407#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 3408 3409/* 3410 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() 3411 * and pageblock_default_order() are unused as pageblock_order is set 3412 * at compile-time. See include/linux/pageblock-flags.h for the values of 3413 * pageblock_order based on the kernel config 3414 */ 3415static inline int pageblock_default_order(unsigned int order) 3416{ 3417 return MAX_ORDER-1; 3418} 3419#define set_pageblock_order(x) do {} while (0) 3420 3421#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 3422 3423/* 3424 * Set up the zone data structures: 3425 * - mark all pages reserved 3426 * - mark all memory queues empty 3427 * - clear the memory bitmaps 3428 */ 3429static void __paginginit free_area_init_core(struct pglist_data *pgdat, 3430 unsigned long *zones_size, unsigned long *zholes_size) 3431{ 3432 enum zone_type j; 3433 int nid = pgdat->node_id; 3434 unsigned long zone_start_pfn = pgdat->node_start_pfn; 3435 int ret; 3436 3437 pgdat_resize_init(pgdat); 3438 pgdat->nr_zones = 0; 3439 init_waitqueue_head(&pgdat->kswapd_wait); 3440 pgdat->kswapd_max_order = 0; 3441 3442 for (j = 0; j < MAX_NR_ZONES; j++) { 3443 struct zone *zone = pgdat->node_zones + j; 3444 unsigned long size, realsize, memmap_pages; 3445 enum lru_list l; 3446 3447 size = zone_spanned_pages_in_node(nid, j, zones_size); 3448 realsize = size - zone_absent_pages_in_node(nid, j, 3449 zholes_size); 3450 3451 /* 3452 * Adjust realsize so that it accounts for how much memory 3453 * is used by this zone for memmap. This affects the watermark 3454 * and per-cpu initialisations 3455 */ 3456 memmap_pages = 3457 PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT; 3458 if (realsize >= memmap_pages) { 3459 realsize -= memmap_pages; 3460 mminit_dprintk(MMINIT_TRACE, "memmap_init", 3461 "%s zone: %lu pages used for memmap\n", 3462 zone_names[j], memmap_pages); 3463 } else 3464 printk(KERN_WARNING 3465 " %s zone: %lu pages exceeds realsize %lu\n", 3466 zone_names[j], memmap_pages, realsize); 3467 3468 /* Account for reserved pages */ 3469 if (j == 0 && realsize > dma_reserve) { 3470 realsize -= dma_reserve; 3471 mminit_dprintk(MMINIT_TRACE, "memmap_init", 3472 "%s zone: %lu pages reserved\n", 3473 zone_names[0], dma_reserve); 3474 } 3475 3476 if (!is_highmem_idx(j)) 3477 nr_kernel_pages += realsize; 3478 nr_all_pages += realsize; 3479 3480 zone->spanned_pages = size; 3481 zone->present_pages = realsize; 3482#ifdef CONFIG_NUMA 3483 zone->node = nid; 3484 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio) 3485 / 100; 3486 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100; 3487#endif 3488 zone->name = zone_names[j]; 3489 spin_lock_init(&zone->lock); 3490 spin_lock_init(&zone->lru_lock); 3491 zone_seqlock_init(zone); 3492 zone->zone_pgdat = pgdat; 3493 3494 zone->prev_priority = DEF_PRIORITY; 3495 3496 zone_pcp_init(zone); 3497 for_each_lru(l) { 3498 INIT_LIST_HEAD(&zone->lru[l].list); 3499 zone->lru[l].nr_scan = 0; 3500 } 3501 zone->recent_rotated[0] = 0; 3502 zone->recent_rotated[1] = 0; 3503 zone->recent_scanned[0] = 0; 3504 zone->recent_scanned[1] = 0; 3505 zap_zone_vm_stats(zone); 3506 zone->flags = 0; 3507 if (!size) 3508 continue; 3509 3510 set_pageblock_order(pageblock_default_order()); 3511 setup_usemap(pgdat, zone, size); 3512 ret = init_currently_empty_zone(zone, zone_start_pfn, 3513 size, MEMMAP_EARLY); 3514 BUG_ON(ret); 3515 memmap_init(size, nid, j, zone_start_pfn); 3516 zone_start_pfn += size; 3517 } 3518} 3519 3520static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat) 3521{ 3522 /* Skip empty nodes */ 3523 if (!pgdat->node_spanned_pages) 3524 return; 3525 3526#ifdef CONFIG_FLAT_NODE_MEM_MAP 3527 /* ia64 gets its own node_mem_map, before this, without bootmem */ 3528 if (!pgdat->node_mem_map) { 3529 unsigned long size, start, end; 3530 struct page *map; 3531 3532 /* 3533 * The zone's endpoints aren't required to be MAX_ORDER 3534 * aligned but the node_mem_map endpoints must be in order 3535 * for the buddy allocator to function correctly. 3536 */ 3537 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); 3538 end = pgdat->node_start_pfn + pgdat->node_spanned_pages; 3539 end = ALIGN(end, MAX_ORDER_NR_PAGES); 3540 size = (end - start) * sizeof(struct page); 3541 map = alloc_remap(pgdat->node_id, size); 3542 if (!map) 3543 map = alloc_bootmem_node(pgdat, size); 3544 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); 3545 } 3546#ifndef CONFIG_NEED_MULTIPLE_NODES 3547 /* 3548 * With no DISCONTIG, the global mem_map is just set as node 0's 3549 */ 3550 if (pgdat == NODE_DATA(0)) { 3551 mem_map = NODE_DATA(0)->node_mem_map; 3552#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3553 if (page_to_pfn(mem_map) != pgdat->node_start_pfn) 3554 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET); 3555#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 3556 } 3557#endif 3558#endif /* CONFIG_FLAT_NODE_MEM_MAP */ 3559} 3560 3561void __paginginit free_area_init_node(int nid, unsigned long *zones_size, 3562 unsigned long node_start_pfn, unsigned long *zholes_size) 3563{ 3564 pg_data_t *pgdat = NODE_DATA(nid); 3565 3566 pgdat->node_id = nid; 3567 pgdat->node_start_pfn = node_start_pfn; 3568 calculate_node_totalpages(pgdat, zones_size, zholes_size); 3569 3570 alloc_node_mem_map(pgdat); 3571#ifdef CONFIG_FLAT_NODE_MEM_MAP 3572 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n", 3573 nid, (unsigned long)pgdat, 3574 (unsigned long)pgdat->node_mem_map); 3575#endif 3576 3577 free_area_init_core(pgdat, zones_size, zholes_size); 3578} 3579 3580#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3581 3582#if MAX_NUMNODES > 1 3583/* 3584 * Figure out the number of possible node ids. 3585 */ 3586static void __init setup_nr_node_ids(void) 3587{ 3588 unsigned int node; 3589 unsigned int highest = 0; 3590 3591 for_each_node_mask(node, node_possible_map) 3592 highest = node; 3593 nr_node_ids = highest + 1; 3594} 3595#else 3596static inline void setup_nr_node_ids(void) 3597{ 3598} 3599#endif 3600 3601/** 3602 * add_active_range - Register a range of PFNs backed by physical memory 3603 * @nid: The node ID the range resides on 3604 * @start_pfn: The start PFN of the available physical memory 3605 * @end_pfn: The end PFN of the available physical memory 3606 * 3607 * These ranges are stored in an early_node_map[] and later used by 3608 * free_area_init_nodes() to calculate zone sizes and holes. If the 3609 * range spans a memory hole, it is up to the architecture to ensure 3610 * the memory is not freed by the bootmem allocator. If possible 3611 * the range being registered will be merged with existing ranges. 3612 */ 3613void __init add_active_range(unsigned int nid, unsigned long start_pfn, 3614 unsigned long end_pfn) 3615{ 3616 int i; 3617 3618 mminit_dprintk(MMINIT_TRACE, "memory_register", 3619 "Entering add_active_range(%d, %#lx, %#lx) " 3620 "%d entries of %d used\n", 3621 nid, start_pfn, end_pfn, 3622 nr_nodemap_entries, MAX_ACTIVE_REGIONS); 3623 3624 mminit_validate_memmodel_limits(&start_pfn, &end_pfn); 3625 3626 /* Merge with existing active regions if possible */ 3627 for (i = 0; i < nr_nodemap_entries; i++) { 3628 if (early_node_map[i].nid != nid) 3629 continue; 3630 3631 /* Skip if an existing region covers this new one */ 3632 if (start_pfn >= early_node_map[i].start_pfn && 3633 end_pfn <= early_node_map[i].end_pfn) 3634 return; 3635 3636 /* Merge forward if suitable */ 3637 if (start_pfn <= early_node_map[i].end_pfn && 3638 end_pfn > early_node_map[i].end_pfn) { 3639 early_node_map[i].end_pfn = end_pfn; 3640 return; 3641 } 3642 3643 /* Merge backward if suitable */ 3644 if (start_pfn < early_node_map[i].end_pfn && 3645 end_pfn >= early_node_map[i].start_pfn) { 3646 early_node_map[i].start_pfn = start_pfn; 3647 return; 3648 } 3649 } 3650 3651 /* Check that early_node_map is large enough */ 3652 if (i >= MAX_ACTIVE_REGIONS) { 3653 printk(KERN_CRIT "More than %d memory regions, truncating\n", 3654 MAX_ACTIVE_REGIONS); 3655 return; 3656 } 3657 3658 early_node_map[i].nid = nid; 3659 early_node_map[i].start_pfn = start_pfn; 3660 early_node_map[i].end_pfn = end_pfn; 3661 nr_nodemap_entries = i + 1; 3662} 3663 3664/** 3665 * remove_active_range - Shrink an existing registered range of PFNs 3666 * @nid: The node id the range is on that should be shrunk 3667 * @start_pfn: The new PFN of the range 3668 * @end_pfn: The new PFN of the range 3669 * 3670 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node. 3671 * The map is kept near the end physical page range that has already been 3672 * registered. This function allows an arch to shrink an existing registered 3673 * range. 3674 */ 3675void __init remove_active_range(unsigned int nid, unsigned long start_pfn, 3676 unsigned long end_pfn) 3677{ 3678 int i, j; 3679 int removed = 0; 3680 3681 printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n", 3682 nid, start_pfn, end_pfn); 3683 3684 /* Find the old active region end and shrink */ 3685 for_each_active_range_index_in_nid(i, nid) { 3686 if (early_node_map[i].start_pfn >= start_pfn && 3687 early_node_map[i].end_pfn <= end_pfn) { 3688 /* clear it */ 3689 early_node_map[i].start_pfn = 0; 3690 early_node_map[i].end_pfn = 0; 3691 removed = 1; 3692 continue; 3693 } 3694 if (early_node_map[i].start_pfn < start_pfn && 3695 early_node_map[i].end_pfn > start_pfn) { 3696 unsigned long temp_end_pfn = early_node_map[i].end_pfn; 3697 early_node_map[i].end_pfn = start_pfn; 3698 if (temp_end_pfn > end_pfn) 3699 add_active_range(nid, end_pfn, temp_end_pfn); 3700 continue; 3701 } 3702 if (early_node_map[i].start_pfn >= start_pfn && 3703 early_node_map[i].end_pfn > end_pfn && 3704 early_node_map[i].start_pfn < end_pfn) { 3705 early_node_map[i].start_pfn = end_pfn; 3706 continue; 3707 } 3708 } 3709 3710 if (!removed) 3711 return; 3712 3713 /* remove the blank ones */ 3714 for (i = nr_nodemap_entries - 1; i > 0; i--) { 3715 if (early_node_map[i].nid != nid) 3716 continue; 3717 if (early_node_map[i].end_pfn) 3718 continue; 3719 /* we found it, get rid of it */ 3720 for (j = i; j < nr_nodemap_entries - 1; j++) 3721 memcpy(&early_node_map[j], &early_node_map[j+1], 3722 sizeof(early_node_map[j])); 3723 j = nr_nodemap_entries - 1; 3724 memset(&early_node_map[j], 0, sizeof(early_node_map[j])); 3725 nr_nodemap_entries--; 3726 } 3727} 3728 3729/** 3730 * remove_all_active_ranges - Remove all currently registered regions 3731 * 3732 * During discovery, it may be found that a table like SRAT is invalid 3733 * and an alternative discovery method must be used. This function removes 3734 * all currently registered regions. 3735 */ 3736void __init remove_all_active_ranges(void) 3737{ 3738 memset(early_node_map, 0, sizeof(early_node_map)); 3739 nr_nodemap_entries = 0; 3740#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE 3741 memset(node_boundary_start_pfn, 0, sizeof(node_boundary_start_pfn)); 3742 memset(node_boundary_end_pfn, 0, sizeof(node_boundary_end_pfn)); 3743#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */ 3744} 3745 3746/* Compare two active node_active_regions */ 3747static int __init cmp_node_active_region(const void *a, const void *b) 3748{ 3749 struct node_active_region *arange = (struct node_active_region *)a; 3750 struct node_active_region *brange = (struct node_active_region *)b; 3751 3752 /* Done this way to avoid overflows */ 3753 if (arange->start_pfn > brange->start_pfn) 3754 return 1; 3755 if (arange->start_pfn < brange->start_pfn) 3756 return -1; 3757 3758 return 0; 3759} 3760 3761/* sort the node_map by start_pfn */ 3762static void __init sort_node_map(void) 3763{ 3764 sort(early_node_map, (size_t)nr_nodemap_entries, 3765 sizeof(struct node_active_region), 3766 cmp_node_active_region, NULL); 3767} 3768 3769/* Find the lowest pfn for a node */ 3770static unsigned long __init find_min_pfn_for_node(int nid) 3771{ 3772 int i; 3773 unsigned long min_pfn = ULONG_MAX; 3774 3775 /* Assuming a sorted map, the first range found has the starting pfn */ 3776 for_each_active_range_index_in_nid(i, nid) 3777 min_pfn = min(min_pfn, early_node_map[i].start_pfn); 3778 3779 if (min_pfn == ULONG_MAX) { 3780 printk(KERN_WARNING 3781 "Could not find start_pfn for node %d\n", nid); 3782 return 0; 3783 } 3784 3785 return min_pfn; 3786} 3787 3788/** 3789 * find_min_pfn_with_active_regions - Find the minimum PFN registered 3790 * 3791 * It returns the minimum PFN based on information provided via 3792 * add_active_range(). 3793 */ 3794unsigned long __init find_min_pfn_with_active_regions(void) 3795{ 3796 return find_min_pfn_for_node(MAX_NUMNODES); 3797} 3798 3799/* 3800 * early_calculate_totalpages() 3801 * Sum pages in active regions for movable zone. 3802 * Populate N_HIGH_MEMORY for calculating usable_nodes. 3803 */ 3804static unsigned long __init early_calculate_totalpages(void) 3805{ 3806 int i; 3807 unsigned long totalpages = 0; 3808 3809 for (i = 0; i < nr_nodemap_entries; i++) { 3810 unsigned long pages = early_node_map[i].end_pfn - 3811 early_node_map[i].start_pfn; 3812 totalpages += pages; 3813 if (pages) 3814 node_set_state(early_node_map[i].nid, N_HIGH_MEMORY); 3815 } 3816 return totalpages; 3817} 3818 3819/* 3820 * Find the PFN the Movable zone begins in each node. Kernel memory 3821 * is spread evenly between nodes as long as the nodes have enough 3822 * memory. When they don't, some nodes will have more kernelcore than 3823 * others 3824 */ 3825static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn) 3826{ 3827 int i, nid; 3828 unsigned long usable_startpfn; 3829 unsigned long kernelcore_node, kernelcore_remaining; 3830 unsigned long totalpages = early_calculate_totalpages(); 3831 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]); 3832 3833 /* 3834 * If movablecore was specified, calculate what size of 3835 * kernelcore that corresponds so that memory usable for 3836 * any allocation type is evenly spread. If both kernelcore 3837 * and movablecore are specified, then the value of kernelcore 3838 * will be used for required_kernelcore if it's greater than 3839 * what movablecore would have allowed. 3840 */ 3841 if (required_movablecore) { 3842 unsigned long corepages; 3843 3844 /* 3845 * Round-up so that ZONE_MOVABLE is at least as large as what 3846 * was requested by the user 3847 */ 3848 required_movablecore = 3849 roundup(required_movablecore, MAX_ORDER_NR_PAGES); 3850 corepages = totalpages - required_movablecore; 3851 3852 required_kernelcore = max(required_kernelcore, corepages); 3853 } 3854 3855 /* If kernelcore was not specified, there is no ZONE_MOVABLE */ 3856 if (!required_kernelcore) 3857 return; 3858 3859 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ 3860 find_usable_zone_for_movable(); 3861 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; 3862 3863restart: 3864 /* Spread kernelcore memory as evenly as possible throughout nodes */ 3865 kernelcore_node = required_kernelcore / usable_nodes; 3866 for_each_node_state(nid, N_HIGH_MEMORY) { 3867 /* 3868 * Recalculate kernelcore_node if the division per node 3869 * now exceeds what is necessary to satisfy the requested 3870 * amount of memory for the kernel 3871 */ 3872 if (required_kernelcore < kernelcore_node) 3873 kernelcore_node = required_kernelcore / usable_nodes; 3874 3875 /* 3876 * As the map is walked, we track how much memory is usable 3877 * by the kernel using kernelcore_remaining. When it is 3878 * 0, the rest of the node is usable by ZONE_MOVABLE 3879 */ 3880 kernelcore_remaining = kernelcore_node; 3881 3882 /* Go through each range of PFNs within this node */ 3883 for_each_active_range_index_in_nid(i, nid) { 3884 unsigned long start_pfn, end_pfn; 3885 unsigned long size_pages; 3886 3887 start_pfn = max(early_node_map[i].start_pfn, 3888 zone_movable_pfn[nid]); 3889 end_pfn = early_node_map[i].end_pfn; 3890 if (start_pfn >= end_pfn) 3891 continue; 3892 3893 /* Account for what is only usable for kernelcore */ 3894 if (start_pfn < usable_startpfn) { 3895 unsigned long kernel_pages; 3896 kernel_pages = min(end_pfn, usable_startpfn) 3897 - start_pfn; 3898 3899 kernelcore_remaining -= min(kernel_pages, 3900 kernelcore_remaining); 3901 required_kernelcore -= min(kernel_pages, 3902 required_kernelcore); 3903 3904 /* Continue if range is now fully accounted */ 3905 if (end_pfn <= usable_startpfn) { 3906 3907 /* 3908 * Push zone_movable_pfn to the end so 3909 * that if we have to rebalance 3910 * kernelcore across nodes, we will 3911 * not double account here 3912 */ 3913 zone_movable_pfn[nid] = end_pfn; 3914 continue; 3915 } 3916 start_pfn = usable_startpfn; 3917 } 3918 3919 /* 3920 * The usable PFN range for ZONE_MOVABLE is from 3921 * start_pfn->end_pfn. Calculate size_pages as the 3922 * number of pages used as kernelcore 3923 */ 3924 size_pages = end_pfn - start_pfn; 3925 if (size_pages > kernelcore_remaining) 3926 size_pages = kernelcore_remaining; 3927 zone_movable_pfn[nid] = start_pfn + size_pages; 3928 3929 /* 3930 * Some kernelcore has been met, update counts and 3931 * break if the kernelcore for this node has been 3932 * satisified 3933 */ 3934 required_kernelcore -= min(required_kernelcore, 3935 size_pages); 3936 kernelcore_remaining -= size_pages; 3937 if (!kernelcore_remaining) 3938 break; 3939 } 3940 } 3941 3942 /* 3943 * If there is still required_kernelcore, we do another pass with one 3944 * less node in the count. This will push zone_movable_pfn[nid] further 3945 * along on the nodes that still have memory until kernelcore is 3946 * satisified 3947 */ 3948 usable_nodes--; 3949 if (usable_nodes && required_kernelcore > usable_nodes) 3950 goto restart; 3951 3952 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ 3953 for (nid = 0; nid < MAX_NUMNODES; nid++) 3954 zone_movable_pfn[nid] = 3955 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); 3956} 3957 3958/* Any regular memory on that node ? */ 3959static void check_for_regular_memory(pg_data_t *pgdat) 3960{ 3961#ifdef CONFIG_HIGHMEM 3962 enum zone_type zone_type; 3963 3964 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) { 3965 struct zone *zone = &pgdat->node_zones[zone_type]; 3966 if (zone->present_pages) 3967 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY); 3968 } 3969#endif 3970} 3971 3972/** 3973 * free_area_init_nodes - Initialise all pg_data_t and zone data 3974 * @max_zone_pfn: an array of max PFNs for each zone 3975 * 3976 * This will call free_area_init_node() for each active node in the system. 3977 * Using the page ranges provided by add_active_range(), the size of each 3978 * zone in each node and their holes is calculated. If the maximum PFN 3979 * between two adjacent zones match, it is assumed that the zone is empty. 3980 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed 3981 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone 3982 * starts where the previous one ended. For example, ZONE_DMA32 starts 3983 * at arch_max_dma_pfn. 3984 */ 3985void __init free_area_init_nodes(unsigned long *max_zone_pfn) 3986{ 3987 unsigned long nid; 3988 int i; 3989 3990 /* Sort early_node_map as initialisation assumes it is sorted */ 3991 sort_node_map(); 3992 3993 /* Record where the zone boundaries are */ 3994 memset(arch_zone_lowest_possible_pfn, 0, 3995 sizeof(arch_zone_lowest_possible_pfn)); 3996 memset(arch_zone_highest_possible_pfn, 0, 3997 sizeof(arch_zone_highest_possible_pfn)); 3998 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); 3999 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; 4000 for (i = 1; i < MAX_NR_ZONES; i++) { 4001 if (i == ZONE_MOVABLE) 4002 continue; 4003 arch_zone_lowest_possible_pfn[i] = 4004 arch_zone_highest_possible_pfn[i-1]; 4005 arch_zone_highest_possible_pfn[i] = 4006 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); 4007 } 4008 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0; 4009 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0; 4010 4011 /* Find the PFNs that ZONE_MOVABLE begins at in each node */ 4012 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); 4013 find_zone_movable_pfns_for_nodes(zone_movable_pfn); 4014 4015 /* Print out the zone ranges */ 4016 printk("Zone PFN ranges:\n"); 4017 for (i = 0; i < MAX_NR_ZONES; i++) { 4018 if (i == ZONE_MOVABLE) 4019 continue; 4020 printk(" %-8s %0#10lx -> %0#10lx\n", 4021 zone_names[i], 4022 arch_zone_lowest_possible_pfn[i], 4023 arch_zone_highest_possible_pfn[i]); 4024 } 4025 4026 /* Print out the PFNs ZONE_MOVABLE begins at in each node */ 4027 printk("Movable zone start PFN for each node\n"); 4028 for (i = 0; i < MAX_NUMNODES; i++) { 4029 if (zone_movable_pfn[i]) 4030 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]); 4031 } 4032 4033 /* Print out the early_node_map[] */ 4034 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries); 4035 for (i = 0; i < nr_nodemap_entries; i++) 4036 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid, 4037 early_node_map[i].start_pfn, 4038 early_node_map[i].end_pfn); 4039 4040 /* Initialise every node */ 4041 mminit_verify_pageflags_layout(); 4042 setup_nr_node_ids(); 4043 for_each_online_node(nid) { 4044 pg_data_t *pgdat = NODE_DATA(nid); 4045 free_area_init_node(nid, NULL, 4046 find_min_pfn_for_node(nid), NULL); 4047 4048 /* Any memory on that node */ 4049 if (pgdat->node_present_pages) 4050 node_set_state(nid, N_HIGH_MEMORY); 4051 check_for_regular_memory(pgdat); 4052 } 4053} 4054 4055static int __init cmdline_parse_core(char *p, unsigned long *core) 4056{ 4057 unsigned long long coremem; 4058 if (!p) 4059 return -EINVAL; 4060 4061 coremem = memparse(p, &p); 4062 *core = coremem >> PAGE_SHIFT; 4063 4064 /* Paranoid check that UL is enough for the coremem value */ 4065 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); 4066 4067 return 0; 4068} 4069 4070/* 4071 * kernelcore=size sets the amount of memory for use for allocations that 4072 * cannot be reclaimed or migrated. 4073 */ 4074static int __init cmdline_parse_kernelcore(char *p) 4075{ 4076 return cmdline_parse_core(p, &required_kernelcore); 4077} 4078 4079/* 4080 * movablecore=size sets the amount of memory for use for allocations that 4081 * can be reclaimed or migrated. 4082 */ 4083static int __init cmdline_parse_movablecore(char *p) 4084{ 4085 return cmdline_parse_core(p, &required_movablecore); 4086} 4087 4088early_param("kernelcore", cmdline_parse_kernelcore); 4089early_param("movablecore", cmdline_parse_movablecore); 4090 4091#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 4092 4093/** 4094 * set_dma_reserve - set the specified number of pages reserved in the first zone 4095 * @new_dma_reserve: The number of pages to mark reserved 4096 * 4097 * The per-cpu batchsize and zone watermarks are determined by present_pages. 4098 * In the DMA zone, a significant percentage may be consumed by kernel image 4099 * and other unfreeable allocations which can skew the watermarks badly. This 4100 * function may optionally be used to account for unfreeable pages in the 4101 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and 4102 * smaller per-cpu batchsize. 4103 */ 4104void __init set_dma_reserve(unsigned long new_dma_reserve) 4105{ 4106 dma_reserve = new_dma_reserve; 4107} 4108 4109#ifndef CONFIG_NEED_MULTIPLE_NODES 4110struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] }; 4111EXPORT_SYMBOL(contig_page_data); 4112#endif 4113 4114void __init free_area_init(unsigned long *zones_size) 4115{ 4116 free_area_init_node(0, zones_size, 4117 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 4118} 4119 4120static int page_alloc_cpu_notify(struct notifier_block *self, 4121 unsigned long action, void *hcpu) 4122{ 4123 int cpu = (unsigned long)hcpu; 4124 4125 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { 4126 drain_pages(cpu); 4127 4128 /* 4129 * Spill the event counters of the dead processor 4130 * into the current processors event counters. 4131 * This artificially elevates the count of the current 4132 * processor. 4133 */ 4134 vm_events_fold_cpu(cpu); 4135 4136 /* 4137 * Zero the differential counters of the dead processor 4138 * so that the vm statistics are consistent. 4139 * 4140 * This is only okay since the processor is dead and cannot 4141 * race with what we are doing. 4142 */ 4143 refresh_cpu_vm_stats(cpu); 4144 } 4145 return NOTIFY_OK; 4146} 4147 4148void __init page_alloc_init(void) 4149{ 4150 hotcpu_notifier(page_alloc_cpu_notify, 0); 4151} 4152 4153/* 4154 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio 4155 * or min_free_kbytes changes. 4156 */ 4157static void calculate_totalreserve_pages(void) 4158{ 4159 struct pglist_data *pgdat; 4160 unsigned long reserve_pages = 0; 4161 enum zone_type i, j; 4162 4163 for_each_online_pgdat(pgdat) { 4164 for (i = 0; i < MAX_NR_ZONES; i++) { 4165 struct zone *zone = pgdat->node_zones + i; 4166 unsigned long max = 0; 4167 4168 /* Find valid and maximum lowmem_reserve in the zone */ 4169 for (j = i; j < MAX_NR_ZONES; j++) { 4170 if (zone->lowmem_reserve[j] > max) 4171 max = zone->lowmem_reserve[j]; 4172 } 4173 4174 /* we treat pages_high as reserved pages. */ 4175 max += zone->pages_high; 4176 4177 if (max > zone->present_pages) 4178 max = zone->present_pages; 4179 reserve_pages += max; 4180 } 4181 } 4182 totalreserve_pages = reserve_pages; 4183} 4184 4185/* 4186 * setup_per_zone_lowmem_reserve - called whenever 4187 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 4188 * has a correct pages reserved value, so an adequate number of 4189 * pages are left in the zone after a successful __alloc_pages(). 4190 */ 4191static void setup_per_zone_lowmem_reserve(void) 4192{ 4193 struct pglist_data *pgdat; 4194 enum zone_type j, idx; 4195 4196 for_each_online_pgdat(pgdat) { 4197 for (j = 0; j < MAX_NR_ZONES; j++) { 4198 struct zone *zone = pgdat->node_zones + j; 4199 unsigned long present_pages = zone->present_pages; 4200 4201 zone->lowmem_reserve[j] = 0; 4202 4203 idx = j; 4204 while (idx) { 4205 struct zone *lower_zone; 4206 4207 idx--; 4208 4209 if (sysctl_lowmem_reserve_ratio[idx] < 1) 4210 sysctl_lowmem_reserve_ratio[idx] = 1; 4211 4212 lower_zone = pgdat->node_zones + idx; 4213 lower_zone->lowmem_reserve[j] = present_pages / 4214 sysctl_lowmem_reserve_ratio[idx]; 4215 present_pages += lower_zone->present_pages; 4216 } 4217 } 4218 } 4219 4220 /* update totalreserve_pages */ 4221 calculate_totalreserve_pages(); 4222} 4223 4224/** 4225 * setup_per_zone_pages_min - called when min_free_kbytes changes. 4226 * 4227 * Ensures that the pages_{min,low,high} values for each zone are set correctly 4228 * with respect to min_free_kbytes. 4229 */ 4230void setup_per_zone_pages_min(void) 4231{ 4232 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 4233 unsigned long lowmem_pages = 0; 4234 struct zone *zone; 4235 unsigned long flags; 4236 4237 /* Calculate total number of !ZONE_HIGHMEM pages */ 4238 for_each_zone(zone) { 4239 if (!is_highmem(zone)) 4240 lowmem_pages += zone->present_pages; 4241 } 4242 4243 for_each_zone(zone) { 4244 u64 tmp; 4245 4246 spin_lock_irqsave(&zone->lru_lock, flags); 4247 tmp = (u64)pages_min * zone->present_pages; 4248 do_div(tmp, lowmem_pages); 4249 if (is_highmem(zone)) { 4250 /* 4251 * __GFP_HIGH and PF_MEMALLOC allocations usually don't 4252 * need highmem pages, so cap pages_min to a small 4253 * value here. 4254 * 4255 * The (pages_high-pages_low) and (pages_low-pages_min) 4256 * deltas controls asynch page reclaim, and so should 4257 * not be capped for highmem. 4258 */ 4259 int min_pages; 4260 4261 min_pages = zone->present_pages / 1024; 4262 if (min_pages < SWAP_CLUSTER_MAX) 4263 min_pages = SWAP_CLUSTER_MAX; 4264 if (min_pages > 128) 4265 min_pages = 128; 4266 zone->pages_min = min_pages; 4267 } else { 4268 /* 4269 * If it's a lowmem zone, reserve a number of pages 4270 * proportionate to the zone's size. 4271 */ 4272 zone->pages_min = tmp; 4273 } 4274 4275 zone->pages_low = zone->pages_min + (tmp >> 2); 4276 zone->pages_high = zone->pages_min + (tmp >> 1); 4277 setup_zone_migrate_reserve(zone); 4278 spin_unlock_irqrestore(&zone->lru_lock, flags); 4279 } 4280 4281 /* update totalreserve_pages */ 4282 calculate_totalreserve_pages(); 4283} 4284 4285/** 4286 * setup_per_zone_inactive_ratio - called when min_free_kbytes changes. 4287 * 4288 * The inactive anon list should be small enough that the VM never has to 4289 * do too much work, but large enough that each inactive page has a chance 4290 * to be referenced again before it is swapped out. 4291 * 4292 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to 4293 * INACTIVE_ANON pages on this zone's LRU, maintained by the 4294 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of 4295 * the anonymous pages are kept on the inactive list. 4296 * 4297 * total target max 4298 * memory ratio inactive anon 4299 * ------------------------------------- 4300 * 10MB 1 5MB 4301 * 100MB 1 50MB 4302 * 1GB 3 250MB 4303 * 10GB 10 0.9GB 4304 * 100GB 31 3GB 4305 * 1TB 101 10GB 4306 * 10TB 320 32GB 4307 */ 4308void setup_per_zone_inactive_ratio(void) 4309{ 4310 struct zone *zone; 4311 4312 for_each_zone(zone) { 4313 unsigned int gb, ratio; 4314 4315 /* Zone size in gigabytes */ 4316 gb = zone->present_pages >> (30 - PAGE_SHIFT); 4317 ratio = int_sqrt(10 * gb); 4318 if (!ratio) 4319 ratio = 1; 4320 4321 zone->inactive_ratio = ratio; 4322 } 4323} 4324 4325/* 4326 * Initialise min_free_kbytes. 4327 * 4328 * For small machines we want it small (128k min). For large machines 4329 * we want it large (64MB max). But it is not linear, because network 4330 * bandwidth does not increase linearly with machine size. We use 4331 * 4332 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 4333 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 4334 * 4335 * which yields 4336 * 4337 * 16MB: 512k 4338 * 32MB: 724k 4339 * 64MB: 1024k 4340 * 128MB: 1448k 4341 * 256MB: 2048k 4342 * 512MB: 2896k 4343 * 1024MB: 4096k 4344 * 2048MB: 5792k 4345 * 4096MB: 8192k 4346 * 8192MB: 11584k 4347 * 16384MB: 16384k 4348 */ 4349static int __init init_per_zone_pages_min(void) 4350{ 4351 unsigned long lowmem_kbytes; 4352 4353 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 4354 4355 min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 4356 if (min_free_kbytes < 128) 4357 min_free_kbytes = 128; 4358 if (min_free_kbytes > 65536) 4359 min_free_kbytes = 65536; 4360 setup_per_zone_pages_min(); 4361 setup_per_zone_lowmem_reserve(); 4362 setup_per_zone_inactive_ratio(); 4363 return 0; 4364} 4365module_init(init_per_zone_pages_min) 4366 4367/* 4368 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 4369 * that we can call two helper functions whenever min_free_kbytes 4370 * changes. 4371 */ 4372int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 4373 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4374{ 4375 proc_dointvec(table, write, file, buffer, length, ppos); 4376 if (write) 4377 setup_per_zone_pages_min(); 4378 return 0; 4379} 4380 4381#ifdef CONFIG_NUMA 4382int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, 4383 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4384{ 4385 struct zone *zone; 4386 int rc; 4387 4388 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4389 if (rc) 4390 return rc; 4391 4392 for_each_zone(zone) 4393 zone->min_unmapped_pages = (zone->present_pages * 4394 sysctl_min_unmapped_ratio) / 100; 4395 return 0; 4396} 4397 4398int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write, 4399 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4400{ 4401 struct zone *zone; 4402 int rc; 4403 4404 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4405 if (rc) 4406 return rc; 4407 4408 for_each_zone(zone) 4409 zone->min_slab_pages = (zone->present_pages * 4410 sysctl_min_slab_ratio) / 100; 4411 return 0; 4412} 4413#endif 4414 4415/* 4416 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 4417 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 4418 * whenever sysctl_lowmem_reserve_ratio changes. 4419 * 4420 * The reserve ratio obviously has absolutely no relation with the 4421 * pages_min watermarks. The lowmem reserve ratio can only make sense 4422 * if in function of the boot time zone sizes. 4423 */ 4424int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, 4425 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4426{ 4427 proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4428 setup_per_zone_lowmem_reserve(); 4429 return 0; 4430} 4431 4432/* 4433 * percpu_pagelist_fraction - changes the pcp->high for each zone on each 4434 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist 4435 * can have before it gets flushed back to buddy allocator. 4436 */ 4437 4438int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, 4439 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4440{ 4441 struct zone *zone; 4442 unsigned int cpu; 4443 int ret; 4444 4445 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4446 if (!write || (ret == -EINVAL)) 4447 return ret; 4448 for_each_zone(zone) { 4449 for_each_online_cpu(cpu) { 4450 unsigned long high; 4451 high = zone->present_pages / percpu_pagelist_fraction; 4452 setup_pagelist_highmark(zone_pcp(zone, cpu), high); 4453 } 4454 } 4455 return 0; 4456} 4457 4458int hashdist = HASHDIST_DEFAULT; 4459 4460#ifdef CONFIG_NUMA 4461static int __init set_hashdist(char *str) 4462{ 4463 if (!str) 4464 return 0; 4465 hashdist = simple_strtoul(str, &str, 0); 4466 return 1; 4467} 4468__setup("hashdist=", set_hashdist); 4469#endif 4470 4471/* 4472 * allocate a large system hash table from bootmem 4473 * - it is assumed that the hash table must contain an exact power-of-2 4474 * quantity of entries 4475 * - limit is the number of hash buckets, not the total allocation size 4476 */ 4477void *__init alloc_large_system_hash(const char *tablename, 4478 unsigned long bucketsize, 4479 unsigned long numentries, 4480 int scale, 4481 int flags, 4482 unsigned int *_hash_shift, 4483 unsigned int *_hash_mask, 4484 unsigned long limit) 4485{ 4486 unsigned long long max = limit; 4487 unsigned long log2qty, size; 4488 void *table = NULL; 4489 4490 /* allow the kernel cmdline to have a say */ 4491 if (!numentries) { 4492 /* round applicable memory size up to nearest megabyte */ 4493 numentries = nr_kernel_pages; 4494 numentries += (1UL << (20 - PAGE_SHIFT)) - 1; 4495 numentries >>= 20 - PAGE_SHIFT; 4496 numentries <<= 20 - PAGE_SHIFT; 4497 4498 /* limit to 1 bucket per 2^scale bytes of low memory */ 4499 if (scale > PAGE_SHIFT) 4500 numentries >>= (scale - PAGE_SHIFT); 4501 else 4502 numentries <<= (PAGE_SHIFT - scale); 4503 4504 /* Make sure we've got at least a 0-order allocation.. */ 4505 if (unlikely((numentries * bucketsize) < PAGE_SIZE)) 4506 numentries = PAGE_SIZE / bucketsize; 4507 } 4508 numentries = roundup_pow_of_two(numentries); 4509 4510 /* limit allocation size to 1/16 total memory by default */ 4511 if (max == 0) { 4512 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 4513 do_div(max, bucketsize); 4514 } 4515 4516 if (numentries > max) 4517 numentries = max; 4518 4519 log2qty = ilog2(numentries); 4520 4521 do { 4522 size = bucketsize << log2qty; 4523 if (flags & HASH_EARLY) 4524 table = alloc_bootmem_nopanic(size); 4525 else if (hashdist) 4526 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 4527 else { 4528 unsigned long order = get_order(size); 4529 table = (void*) __get_free_pages(GFP_ATOMIC, order); 4530 /* 4531 * If bucketsize is not a power-of-two, we may free 4532 * some pages at the end of hash table. 4533 */ 4534 if (table) { 4535 unsigned long alloc_end = (unsigned long)table + 4536 (PAGE_SIZE << order); 4537 unsigned long used = (unsigned long)table + 4538 PAGE_ALIGN(size); 4539 split_page(virt_to_page(table), order); 4540 while (used < alloc_end) { 4541 free_page(used); 4542 used += PAGE_SIZE; 4543 } 4544 } 4545 } 4546 } while (!table && size > PAGE_SIZE && --log2qty); 4547 4548 if (!table) 4549 panic("Failed to allocate %s hash table\n", tablename); 4550 4551 printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n", 4552 tablename, 4553 (1U << log2qty), 4554 ilog2(size) - PAGE_SHIFT, 4555 size); 4556 4557 if (_hash_shift) 4558 *_hash_shift = log2qty; 4559 if (_hash_mask) 4560 *_hash_mask = (1 << log2qty) - 1; 4561 4562 return table; 4563} 4564 4565#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE 4566struct page *pfn_to_page(unsigned long pfn) 4567{ 4568 return __pfn_to_page(pfn); 4569} 4570unsigned long page_to_pfn(struct page *page) 4571{ 4572 return __page_to_pfn(page); 4573} 4574EXPORT_SYMBOL(pfn_to_page); 4575EXPORT_SYMBOL(page_to_pfn); 4576#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */ 4577 4578/* Return a pointer to the bitmap storing bits affecting a block of pages */ 4579static inline unsigned long *get_pageblock_bitmap(struct zone *zone, 4580 unsigned long pfn) 4581{ 4582#ifdef CONFIG_SPARSEMEM 4583 return __pfn_to_section(pfn)->pageblock_flags; 4584#else 4585 return zone->pageblock_flags; 4586#endif /* CONFIG_SPARSEMEM */ 4587} 4588 4589static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) 4590{ 4591#ifdef CONFIG_SPARSEMEM 4592 pfn &= (PAGES_PER_SECTION-1); 4593 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 4594#else 4595 pfn = pfn - zone->zone_start_pfn; 4596 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 4597#endif /* CONFIG_SPARSEMEM */ 4598} 4599 4600/** 4601 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages 4602 * @page: The page within the block of interest 4603 * @start_bitidx: The first bit of interest to retrieve 4604 * @end_bitidx: The last bit of interest 4605 * returns pageblock_bits flags 4606 */ 4607unsigned long get_pageblock_flags_group(struct page *page, 4608 int start_bitidx, int end_bitidx) 4609{ 4610 struct zone *zone; 4611 unsigned long *bitmap; 4612 unsigned long pfn, bitidx; 4613 unsigned long flags = 0; 4614 unsigned long value = 1; 4615 4616 zone = page_zone(page); 4617 pfn = page_to_pfn(page); 4618 bitmap = get_pageblock_bitmap(zone, pfn); 4619 bitidx = pfn_to_bitidx(zone, pfn); 4620 4621 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 4622 if (test_bit(bitidx + start_bitidx, bitmap)) 4623 flags |= value; 4624 4625 return flags; 4626} 4627 4628/** 4629 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages 4630 * @page: The page within the block of interest 4631 * @start_bitidx: The first bit of interest 4632 * @end_bitidx: The last bit of interest 4633 * @flags: The flags to set 4634 */ 4635void set_pageblock_flags_group(struct page *page, unsigned long flags, 4636 int start_bitidx, int end_bitidx) 4637{ 4638 struct zone *zone; 4639 unsigned long *bitmap; 4640 unsigned long pfn, bitidx; 4641 unsigned long value = 1; 4642 4643 zone = page_zone(page); 4644 pfn = page_to_pfn(page); 4645 bitmap = get_pageblock_bitmap(zone, pfn); 4646 bitidx = pfn_to_bitidx(zone, pfn); 4647 VM_BUG_ON(pfn < zone->zone_start_pfn); 4648 VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages); 4649 4650 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 4651 if (flags & value) 4652 __set_bit(bitidx + start_bitidx, bitmap); 4653 else 4654 __clear_bit(bitidx + start_bitidx, bitmap); 4655} 4656 4657/* 4658 * This is designed as sub function...plz see page_isolation.c also. 4659 * set/clear page block's type to be ISOLATE. 4660 * page allocater never alloc memory from ISOLATE block. 4661 */ 4662 4663int set_migratetype_isolate(struct page *page) 4664{ 4665 struct zone *zone; 4666 unsigned long flags; 4667 int ret = -EBUSY; 4668 4669 zone = page_zone(page); 4670 spin_lock_irqsave(&zone->lock, flags); 4671 /* 4672 * In future, more migrate types will be able to be isolation target. 4673 */ 4674 if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE) 4675 goto out; 4676 set_pageblock_migratetype(page, MIGRATE_ISOLATE); 4677 move_freepages_block(zone, page, MIGRATE_ISOLATE); 4678 ret = 0; 4679out: 4680 spin_unlock_irqrestore(&zone->lock, flags); 4681 if (!ret) 4682 drain_all_pages(); 4683 return ret; 4684} 4685 4686void unset_migratetype_isolate(struct page *page) 4687{ 4688 struct zone *zone; 4689 unsigned long flags; 4690 zone = page_zone(page); 4691 spin_lock_irqsave(&zone->lock, flags); 4692 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE) 4693 goto out; 4694 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 4695 move_freepages_block(zone, page, MIGRATE_MOVABLE); 4696out: 4697 spin_unlock_irqrestore(&zone->lock, flags); 4698} 4699 4700#ifdef CONFIG_MEMORY_HOTREMOVE 4701/* 4702 * All pages in the range must be isolated before calling this. 4703 */ 4704void 4705__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) 4706{ 4707 struct page *page; 4708 struct zone *zone; 4709 int order, i; 4710 unsigned long pfn; 4711 unsigned long flags; 4712 /* find the first valid pfn */ 4713 for (pfn = start_pfn; pfn < end_pfn; pfn++) 4714 if (pfn_valid(pfn)) 4715 break; 4716 if (pfn == end_pfn) 4717 return; 4718 zone = page_zone(pfn_to_page(pfn)); 4719 spin_lock_irqsave(&zone->lock, flags); 4720 pfn = start_pfn; 4721 while (pfn < end_pfn) { 4722 if (!pfn_valid(pfn)) { 4723 pfn++; 4724 continue; 4725 } 4726 page = pfn_to_page(pfn); 4727 BUG_ON(page_count(page)); 4728 BUG_ON(!PageBuddy(page)); 4729 order = page_order(page); 4730#ifdef CONFIG_DEBUG_VM 4731 printk(KERN_INFO "remove from free list %lx %d %lx\n", 4732 pfn, 1 << order, end_pfn); 4733#endif 4734 list_del(&page->lru); 4735 rmv_page_order(page); 4736 zone->free_area[order].nr_free--; 4737 __mod_zone_page_state(zone, NR_FREE_PAGES, 4738 - (1UL << order)); 4739 for (i = 0; i < (1 << order); i++) 4740 SetPageReserved((page+i)); 4741 pfn += (1 << order); 4742 } 4743 spin_unlock_irqrestore(&zone->lock, flags); 4744} 4745#endif 4746