page_alloc.c revision 74768ed833344bb0f82b97cee46320a3d7f09ecd
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; 271 272 set_compound_page_dtor(page, free_compound_page); 273 set_compound_order(page, order); 274 __SetPageHead(page); 275 for (i = 1; i < nr_pages; i++) { 276 struct page *p = page + i; 277 278 __SetPageTail(p); 279 p->first_page = page; 280 } 281} 282 283static void destroy_compound_page(struct page *page, unsigned long order) 284{ 285 int i; 286 int nr_pages = 1 << order; 287 288 if (unlikely(compound_order(page) != order)) 289 bad_page(page); 290 291 if (unlikely(!PageHead(page))) 292 bad_page(page); 293 __ClearPageHead(page); 294 for (i = 1; i < nr_pages; i++) { 295 struct page *p = page + i; 296 297 if (unlikely(!PageTail(p) | 298 (p->first_page != page))) 299 bad_page(page); 300 __ClearPageTail(p); 301 } 302} 303 304static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) 305{ 306 int i; 307 308 /* 309 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO 310 * and __GFP_HIGHMEM from hard or soft interrupt context. 311 */ 312 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); 313 for (i = 0; i < (1 << order); i++) 314 clear_highpage(page + i); 315} 316 317static inline void set_page_order(struct page *page, int order) 318{ 319 set_page_private(page, order); 320 __SetPageBuddy(page); 321} 322 323static inline void rmv_page_order(struct page *page) 324{ 325 __ClearPageBuddy(page); 326 set_page_private(page, 0); 327} 328 329/* 330 * Locate the struct page for both the matching buddy in our 331 * pair (buddy1) and the combined O(n+1) page they form (page). 332 * 333 * 1) Any buddy B1 will have an order O twin B2 which satisfies 334 * the following equation: 335 * B2 = B1 ^ (1 << O) 336 * For example, if the starting buddy (buddy2) is #8 its order 337 * 1 buddy is #10: 338 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 339 * 340 * 2) Any buddy B will have an order O+1 parent P which 341 * satisfies the following equation: 342 * P = B & ~(1 << O) 343 * 344 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 345 */ 346static inline struct page * 347__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order) 348{ 349 unsigned long buddy_idx = page_idx ^ (1 << order); 350 351 return page + (buddy_idx - page_idx); 352} 353 354static inline unsigned long 355__find_combined_index(unsigned long page_idx, unsigned int order) 356{ 357 return (page_idx & ~(1 << order)); 358} 359 360/* 361 * This function checks whether a page is free && is the buddy 362 * we can do coalesce a page and its buddy if 363 * (a) the buddy is not in a hole && 364 * (b) the buddy is in the buddy system && 365 * (c) a page and its buddy have the same order && 366 * (d) a page and its buddy are in the same zone. 367 * 368 * For recording whether a page is in the buddy system, we use PG_buddy. 369 * Setting, clearing, and testing PG_buddy is serialized by zone->lock. 370 * 371 * For recording page's order, we use page_private(page). 372 */ 373static inline int page_is_buddy(struct page *page, struct page *buddy, 374 int order) 375{ 376 if (!pfn_valid_within(page_to_pfn(buddy))) 377 return 0; 378 379 if (page_zone_id(page) != page_zone_id(buddy)) 380 return 0; 381 382 if (PageBuddy(buddy) && page_order(buddy) == order) { 383 BUG_ON(page_count(buddy) != 0); 384 return 1; 385 } 386 return 0; 387} 388 389/* 390 * Freeing function for a buddy system allocator. 391 * 392 * The concept of a buddy system is to maintain direct-mapped table 393 * (containing bit values) for memory blocks of various "orders". 394 * The bottom level table contains the map for the smallest allocatable 395 * units of memory (here, pages), and each level above it describes 396 * pairs of units from the levels below, hence, "buddies". 397 * At a high level, all that happens here is marking the table entry 398 * at the bottom level available, and propagating the changes upward 399 * as necessary, plus some accounting needed to play nicely with other 400 * parts of the VM system. 401 * At each level, we keep a list of pages, which are heads of continuous 402 * free pages of length of (1 << order) and marked with PG_buddy. Page's 403 * order is recorded in page_private(page) field. 404 * So when we are allocating or freeing one, we can derive the state of the 405 * other. That is, if we allocate a small block, and both were 406 * free, the remainder of the region must be split into blocks. 407 * If a block is freed, and its buddy is also free, then this 408 * triggers coalescing into a block of larger size. 409 * 410 * -- wli 411 */ 412 413static inline void __free_one_page(struct page *page, 414 struct zone *zone, unsigned int order) 415{ 416 unsigned long page_idx; 417 int order_size = 1 << order; 418 int migratetype = get_pageblock_migratetype(page); 419 420 if (unlikely(PageCompound(page))) 421 destroy_compound_page(page, order); 422 423 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); 424 425 VM_BUG_ON(page_idx & (order_size - 1)); 426 VM_BUG_ON(bad_range(zone, page)); 427 428 __mod_zone_page_state(zone, NR_FREE_PAGES, order_size); 429 while (order < MAX_ORDER-1) { 430 unsigned long combined_idx; 431 struct page *buddy; 432 433 buddy = __page_find_buddy(page, page_idx, order); 434 if (!page_is_buddy(page, buddy, order)) 435 break; 436 437 /* Our buddy is free, merge with it and move up one order. */ 438 list_del(&buddy->lru); 439 zone->free_area[order].nr_free--; 440 rmv_page_order(buddy); 441 combined_idx = __find_combined_index(page_idx, order); 442 page = page + (combined_idx - page_idx); 443 page_idx = combined_idx; 444 order++; 445 } 446 set_page_order(page, order); 447 list_add(&page->lru, 448 &zone->free_area[order].free_list[migratetype]); 449 zone->free_area[order].nr_free++; 450} 451 452static inline int free_pages_check(struct page *page) 453{ 454 if (unlikely(page_mapcount(page) | 455 (page->mapping != NULL) | 456 (page_get_page_cgroup(page) != NULL) | 457 (page_count(page) != 0) | 458 (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) 459 bad_page(page); 460 if (PageDirty(page)) 461 __ClearPageDirty(page); 462 /* 463 * For now, we report if PG_reserved was found set, but do not 464 * clear it, and do not free the page. But we shall soon need 465 * to do more, for when the ZERO_PAGE count wraps negative. 466 */ 467 return PageReserved(page); 468} 469 470/* 471 * Frees a list of pages. 472 * Assumes all pages on list are in same zone, and of same order. 473 * count is the number of pages to free. 474 * 475 * If the zone was previously in an "all pages pinned" state then look to 476 * see if this freeing clears that state. 477 * 478 * And clear the zone's pages_scanned counter, to hold off the "all pages are 479 * pinned" detection logic. 480 */ 481static void free_pages_bulk(struct zone *zone, int count, 482 struct list_head *list, int order) 483{ 484 spin_lock(&zone->lock); 485 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); 486 zone->pages_scanned = 0; 487 while (count--) { 488 struct page *page; 489 490 VM_BUG_ON(list_empty(list)); 491 page = list_entry(list->prev, struct page, lru); 492 /* have to delete it as __free_one_page list manipulates */ 493 list_del(&page->lru); 494 __free_one_page(page, zone, order); 495 } 496 spin_unlock(&zone->lock); 497} 498 499static void free_one_page(struct zone *zone, struct page *page, int order) 500{ 501 spin_lock(&zone->lock); 502 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); 503 zone->pages_scanned = 0; 504 __free_one_page(page, zone, order); 505 spin_unlock(&zone->lock); 506} 507 508static void __free_pages_ok(struct page *page, unsigned int order) 509{ 510 unsigned long flags; 511 int i; 512 int reserved = 0; 513 514 for (i = 0 ; i < (1 << order) ; ++i) 515 reserved += free_pages_check(page + i); 516 if (reserved) 517 return; 518 519 if (!PageHighMem(page)) { 520 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order); 521 debug_check_no_obj_freed(page_address(page), 522 PAGE_SIZE << order); 523 } 524 arch_free_page(page, order); 525 kernel_map_pages(page, 1 << order, 0); 526 527 local_irq_save(flags); 528 __count_vm_events(PGFREE, 1 << order); 529 free_one_page(page_zone(page), page, order); 530 local_irq_restore(flags); 531} 532 533/* 534 * permit the bootmem allocator to evade page validation on high-order frees 535 */ 536void __meminit __free_pages_bootmem(struct page *page, unsigned int order) 537{ 538 if (order == 0) { 539 __ClearPageReserved(page); 540 set_page_count(page, 0); 541 set_page_refcounted(page); 542 __free_page(page); 543 } else { 544 int loop; 545 546 prefetchw(page); 547 for (loop = 0; loop < BITS_PER_LONG; loop++) { 548 struct page *p = &page[loop]; 549 550 if (loop + 1 < BITS_PER_LONG) 551 prefetchw(p + 1); 552 __ClearPageReserved(p); 553 set_page_count(p, 0); 554 } 555 556 set_page_refcounted(page); 557 __free_pages(page, order); 558 } 559} 560 561 562/* 563 * The order of subdivision here is critical for the IO subsystem. 564 * Please do not alter this order without good reasons and regression 565 * testing. Specifically, as large blocks of memory are subdivided, 566 * the order in which smaller blocks are delivered depends on the order 567 * they're subdivided in this function. This is the primary factor 568 * influencing the order in which pages are delivered to the IO 569 * subsystem according to empirical testing, and this is also justified 570 * by considering the behavior of a buddy system containing a single 571 * large block of memory acted on by a series of small allocations. 572 * This behavior is a critical factor in sglist merging's success. 573 * 574 * -- wli 575 */ 576static inline void expand(struct zone *zone, struct page *page, 577 int low, int high, struct free_area *area, 578 int migratetype) 579{ 580 unsigned long size = 1 << high; 581 582 while (high > low) { 583 area--; 584 high--; 585 size >>= 1; 586 VM_BUG_ON(bad_range(zone, &page[size])); 587 list_add(&page[size].lru, &area->free_list[migratetype]); 588 area->nr_free++; 589 set_page_order(&page[size], high); 590 } 591} 592 593/* 594 * This page is about to be returned from the page allocator 595 */ 596static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) 597{ 598 if (unlikely(page_mapcount(page) | 599 (page->mapping != NULL) | 600 (page_get_page_cgroup(page) != NULL) | 601 (page_count(page) != 0) | 602 (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) 603 bad_page(page); 604 605 /* 606 * For now, we report if PG_reserved was found set, but do not 607 * clear it, and do not allocate the page: as a safety net. 608 */ 609 if (PageReserved(page)) 610 return 1; 611 612 page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_reclaim | 613 1 << PG_referenced | 1 << PG_arch_1 | 614 1 << PG_owner_priv_1 | 1 << PG_mappedtodisk); 615 set_page_private(page, 0); 616 set_page_refcounted(page); 617 618 arch_alloc_page(page, order); 619 kernel_map_pages(page, 1 << order, 1); 620 621 if (gfp_flags & __GFP_ZERO) 622 prep_zero_page(page, order, gfp_flags); 623 624 if (order && (gfp_flags & __GFP_COMP)) 625 prep_compound_page(page, order); 626 627 return 0; 628} 629 630/* 631 * Go through the free lists for the given migratetype and remove 632 * the smallest available page from the freelists 633 */ 634static struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, 635 int migratetype) 636{ 637 unsigned int current_order; 638 struct free_area * area; 639 struct page *page; 640 641 /* Find a page of the appropriate size in the preferred list */ 642 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 643 area = &(zone->free_area[current_order]); 644 if (list_empty(&area->free_list[migratetype])) 645 continue; 646 647 page = list_entry(area->free_list[migratetype].next, 648 struct page, lru); 649 list_del(&page->lru); 650 rmv_page_order(page); 651 area->nr_free--; 652 __mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order)); 653 expand(zone, page, order, current_order, area, migratetype); 654 return page; 655 } 656 657 return NULL; 658} 659 660 661/* 662 * This array describes the order lists are fallen back to when 663 * the free lists for the desirable migrate type are depleted 664 */ 665static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = { 666 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 667 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 668 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, 669 [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */ 670}; 671 672/* 673 * Move the free pages in a range to the free lists of the requested type. 674 * Note that start_page and end_pages are not aligned on a pageblock 675 * boundary. If alignment is required, use move_freepages_block() 676 */ 677static int move_freepages(struct zone *zone, 678 struct page *start_page, struct page *end_page, 679 int migratetype) 680{ 681 struct page *page; 682 unsigned long order; 683 int pages_moved = 0; 684 685#ifndef CONFIG_HOLES_IN_ZONE 686 /* 687 * page_zone is not safe to call in this context when 688 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant 689 * anyway as we check zone boundaries in move_freepages_block(). 690 * Remove at a later date when no bug reports exist related to 691 * grouping pages by mobility 692 */ 693 BUG_ON(page_zone(start_page) != page_zone(end_page)); 694#endif 695 696 for (page = start_page; page <= end_page;) { 697 if (!pfn_valid_within(page_to_pfn(page))) { 698 page++; 699 continue; 700 } 701 702 if (!PageBuddy(page)) { 703 page++; 704 continue; 705 } 706 707 order = page_order(page); 708 list_del(&page->lru); 709 list_add(&page->lru, 710 &zone->free_area[order].free_list[migratetype]); 711 page += 1 << order; 712 pages_moved += 1 << order; 713 } 714 715 return pages_moved; 716} 717 718static int move_freepages_block(struct zone *zone, struct page *page, 719 int migratetype) 720{ 721 unsigned long start_pfn, end_pfn; 722 struct page *start_page, *end_page; 723 724 start_pfn = page_to_pfn(page); 725 start_pfn = start_pfn & ~(pageblock_nr_pages-1); 726 start_page = pfn_to_page(start_pfn); 727 end_page = start_page + pageblock_nr_pages - 1; 728 end_pfn = start_pfn + pageblock_nr_pages - 1; 729 730 /* Do not cross zone boundaries */ 731 if (start_pfn < zone->zone_start_pfn) 732 start_page = page; 733 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages) 734 return 0; 735 736 return move_freepages(zone, start_page, end_page, migratetype); 737} 738 739/* Remove an element from the buddy allocator from the fallback list */ 740static struct page *__rmqueue_fallback(struct zone *zone, int order, 741 int start_migratetype) 742{ 743 struct free_area * area; 744 int current_order; 745 struct page *page; 746 int migratetype, i; 747 748 /* Find the largest possible block of pages in the other list */ 749 for (current_order = MAX_ORDER-1; current_order >= order; 750 --current_order) { 751 for (i = 0; i < MIGRATE_TYPES - 1; i++) { 752 migratetype = fallbacks[start_migratetype][i]; 753 754 /* MIGRATE_RESERVE handled later if necessary */ 755 if (migratetype == MIGRATE_RESERVE) 756 continue; 757 758 area = &(zone->free_area[current_order]); 759 if (list_empty(&area->free_list[migratetype])) 760 continue; 761 762 page = list_entry(area->free_list[migratetype].next, 763 struct page, lru); 764 area->nr_free--; 765 766 /* 767 * If breaking a large block of pages, move all free 768 * pages to the preferred allocation list. If falling 769 * back for a reclaimable kernel allocation, be more 770 * agressive about taking ownership of free pages 771 */ 772 if (unlikely(current_order >= (pageblock_order >> 1)) || 773 start_migratetype == MIGRATE_RECLAIMABLE) { 774 unsigned long pages; 775 pages = move_freepages_block(zone, page, 776 start_migratetype); 777 778 /* Claim the whole block if over half of it is free */ 779 if (pages >= (1 << (pageblock_order-1))) 780 set_pageblock_migratetype(page, 781 start_migratetype); 782 783 migratetype = start_migratetype; 784 } 785 786 /* Remove the page from the freelists */ 787 list_del(&page->lru); 788 rmv_page_order(page); 789 __mod_zone_page_state(zone, NR_FREE_PAGES, 790 -(1UL << order)); 791 792 if (current_order == pageblock_order) 793 set_pageblock_migratetype(page, 794 start_migratetype); 795 796 expand(zone, page, order, current_order, area, migratetype); 797 return page; 798 } 799 } 800 801 /* Use MIGRATE_RESERVE rather than fail an allocation */ 802 return __rmqueue_smallest(zone, order, MIGRATE_RESERVE); 803} 804 805/* 806 * Do the hard work of removing an element from the buddy allocator. 807 * Call me with the zone->lock already held. 808 */ 809static struct page *__rmqueue(struct zone *zone, unsigned int order, 810 int migratetype) 811{ 812 struct page *page; 813 814 page = __rmqueue_smallest(zone, order, migratetype); 815 816 if (unlikely(!page)) 817 page = __rmqueue_fallback(zone, order, migratetype); 818 819 return page; 820} 821 822/* 823 * Obtain a specified number of elements from the buddy allocator, all under 824 * a single hold of the lock, for efficiency. Add them to the supplied list. 825 * Returns the number of new pages which were placed at *list. 826 */ 827static int rmqueue_bulk(struct zone *zone, unsigned int order, 828 unsigned long count, struct list_head *list, 829 int migratetype) 830{ 831 int i; 832 833 spin_lock(&zone->lock); 834 for (i = 0; i < count; ++i) { 835 struct page *page = __rmqueue(zone, order, migratetype); 836 if (unlikely(page == NULL)) 837 break; 838 839 /* 840 * Split buddy pages returned by expand() are received here 841 * in physical page order. The page is added to the callers and 842 * list and the list head then moves forward. From the callers 843 * perspective, the linked list is ordered by page number in 844 * some conditions. This is useful for IO devices that can 845 * merge IO requests if the physical pages are ordered 846 * properly. 847 */ 848 list_add(&page->lru, list); 849 set_page_private(page, migratetype); 850 list = &page->lru; 851 } 852 spin_unlock(&zone->lock); 853 return i; 854} 855 856#ifdef CONFIG_NUMA 857/* 858 * Called from the vmstat counter updater to drain pagesets of this 859 * currently executing processor on remote nodes after they have 860 * expired. 861 * 862 * Note that this function must be called with the thread pinned to 863 * a single processor. 864 */ 865void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) 866{ 867 unsigned long flags; 868 int to_drain; 869 870 local_irq_save(flags); 871 if (pcp->count >= pcp->batch) 872 to_drain = pcp->batch; 873 else 874 to_drain = pcp->count; 875 free_pages_bulk(zone, to_drain, &pcp->list, 0); 876 pcp->count -= to_drain; 877 local_irq_restore(flags); 878} 879#endif 880 881/* 882 * Drain pages of the indicated processor. 883 * 884 * The processor must either be the current processor and the 885 * thread pinned to the current processor or a processor that 886 * is not online. 887 */ 888static void drain_pages(unsigned int cpu) 889{ 890 unsigned long flags; 891 struct zone *zone; 892 893 for_each_zone(zone) { 894 struct per_cpu_pageset *pset; 895 struct per_cpu_pages *pcp; 896 897 if (!populated_zone(zone)) 898 continue; 899 900 pset = zone_pcp(zone, cpu); 901 902 pcp = &pset->pcp; 903 local_irq_save(flags); 904 free_pages_bulk(zone, pcp->count, &pcp->list, 0); 905 pcp->count = 0; 906 local_irq_restore(flags); 907 } 908} 909 910/* 911 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 912 */ 913void drain_local_pages(void *arg) 914{ 915 drain_pages(smp_processor_id()); 916} 917 918/* 919 * Spill all the per-cpu pages from all CPUs back into the buddy allocator 920 */ 921void drain_all_pages(void) 922{ 923 on_each_cpu(drain_local_pages, NULL, 1); 924} 925 926#ifdef CONFIG_HIBERNATION 927 928void mark_free_pages(struct zone *zone) 929{ 930 unsigned long pfn, max_zone_pfn; 931 unsigned long flags; 932 int order, t; 933 struct list_head *curr; 934 935 if (!zone->spanned_pages) 936 return; 937 938 spin_lock_irqsave(&zone->lock, flags); 939 940 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; 941 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 942 if (pfn_valid(pfn)) { 943 struct page *page = pfn_to_page(pfn); 944 945 if (!swsusp_page_is_forbidden(page)) 946 swsusp_unset_page_free(page); 947 } 948 949 for_each_migratetype_order(order, t) { 950 list_for_each(curr, &zone->free_area[order].free_list[t]) { 951 unsigned long i; 952 953 pfn = page_to_pfn(list_entry(curr, struct page, lru)); 954 for (i = 0; i < (1UL << order); i++) 955 swsusp_set_page_free(pfn_to_page(pfn + i)); 956 } 957 } 958 spin_unlock_irqrestore(&zone->lock, flags); 959} 960#endif /* CONFIG_PM */ 961 962/* 963 * Free a 0-order page 964 */ 965static void free_hot_cold_page(struct page *page, int cold) 966{ 967 struct zone *zone = page_zone(page); 968 struct per_cpu_pages *pcp; 969 unsigned long flags; 970 971 if (PageAnon(page)) 972 page->mapping = NULL; 973 if (free_pages_check(page)) 974 return; 975 976 if (!PageHighMem(page)) { 977 debug_check_no_locks_freed(page_address(page), PAGE_SIZE); 978 debug_check_no_obj_freed(page_address(page), PAGE_SIZE); 979 } 980 arch_free_page(page, 0); 981 kernel_map_pages(page, 1, 0); 982 983 pcp = &zone_pcp(zone, get_cpu())->pcp; 984 local_irq_save(flags); 985 __count_vm_event(PGFREE); 986 if (cold) 987 list_add_tail(&page->lru, &pcp->list); 988 else 989 list_add(&page->lru, &pcp->list); 990 set_page_private(page, get_pageblock_migratetype(page)); 991 pcp->count++; 992 if (pcp->count >= pcp->high) { 993 free_pages_bulk(zone, pcp->batch, &pcp->list, 0); 994 pcp->count -= pcp->batch; 995 } 996 local_irq_restore(flags); 997 put_cpu(); 998} 999 1000void free_hot_page(struct page *page) 1001{ 1002 free_hot_cold_page(page, 0); 1003} 1004 1005void free_cold_page(struct page *page) 1006{ 1007 free_hot_cold_page(page, 1); 1008} 1009 1010/* 1011 * split_page takes a non-compound higher-order page, and splits it into 1012 * n (1<<order) sub-pages: page[0..n] 1013 * Each sub-page must be freed individually. 1014 * 1015 * Note: this is probably too low level an operation for use in drivers. 1016 * Please consult with lkml before using this in your driver. 1017 */ 1018void split_page(struct page *page, unsigned int order) 1019{ 1020 int i; 1021 1022 VM_BUG_ON(PageCompound(page)); 1023 VM_BUG_ON(!page_count(page)); 1024 for (i = 1; i < (1 << order); i++) 1025 set_page_refcounted(page + i); 1026} 1027 1028/* 1029 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 1030 * we cheat by calling it from here, in the order > 0 path. Saves a branch 1031 * or two. 1032 */ 1033static struct page *buffered_rmqueue(struct zone *preferred_zone, 1034 struct zone *zone, int order, gfp_t gfp_flags) 1035{ 1036 unsigned long flags; 1037 struct page *page; 1038 int cold = !!(gfp_flags & __GFP_COLD); 1039 int cpu; 1040 int migratetype = allocflags_to_migratetype(gfp_flags); 1041 1042again: 1043 cpu = get_cpu(); 1044 if (likely(order == 0)) { 1045 struct per_cpu_pages *pcp; 1046 1047 pcp = &zone_pcp(zone, cpu)->pcp; 1048 local_irq_save(flags); 1049 if (!pcp->count) { 1050 pcp->count = rmqueue_bulk(zone, 0, 1051 pcp->batch, &pcp->list, migratetype); 1052 if (unlikely(!pcp->count)) 1053 goto failed; 1054 } 1055 1056 /* Find a page of the appropriate migrate type */ 1057 if (cold) { 1058 list_for_each_entry_reverse(page, &pcp->list, lru) 1059 if (page_private(page) == migratetype) 1060 break; 1061 } else { 1062 list_for_each_entry(page, &pcp->list, lru) 1063 if (page_private(page) == migratetype) 1064 break; 1065 } 1066 1067 /* Allocate more to the pcp list if necessary */ 1068 if (unlikely(&page->lru == &pcp->list)) { 1069 pcp->count += rmqueue_bulk(zone, 0, 1070 pcp->batch, &pcp->list, migratetype); 1071 page = list_entry(pcp->list.next, struct page, lru); 1072 } 1073 1074 list_del(&page->lru); 1075 pcp->count--; 1076 } else { 1077 spin_lock_irqsave(&zone->lock, flags); 1078 page = __rmqueue(zone, order, migratetype); 1079 spin_unlock(&zone->lock); 1080 if (!page) 1081 goto failed; 1082 } 1083 1084 __count_zone_vm_events(PGALLOC, zone, 1 << order); 1085 zone_statistics(preferred_zone, zone); 1086 local_irq_restore(flags); 1087 put_cpu(); 1088 1089 VM_BUG_ON(bad_range(zone, page)); 1090 if (prep_new_page(page, order, gfp_flags)) 1091 goto again; 1092 return page; 1093 1094failed: 1095 local_irq_restore(flags); 1096 put_cpu(); 1097 return NULL; 1098} 1099 1100#define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */ 1101#define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */ 1102#define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */ 1103#define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */ 1104#define ALLOC_HARDER 0x10 /* try to alloc harder */ 1105#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 1106#define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 1107 1108#ifdef CONFIG_FAIL_PAGE_ALLOC 1109 1110static struct fail_page_alloc_attr { 1111 struct fault_attr attr; 1112 1113 u32 ignore_gfp_highmem; 1114 u32 ignore_gfp_wait; 1115 u32 min_order; 1116 1117#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1118 1119 struct dentry *ignore_gfp_highmem_file; 1120 struct dentry *ignore_gfp_wait_file; 1121 struct dentry *min_order_file; 1122 1123#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1124 1125} fail_page_alloc = { 1126 .attr = FAULT_ATTR_INITIALIZER, 1127 .ignore_gfp_wait = 1, 1128 .ignore_gfp_highmem = 1, 1129 .min_order = 1, 1130}; 1131 1132static int __init setup_fail_page_alloc(char *str) 1133{ 1134 return setup_fault_attr(&fail_page_alloc.attr, str); 1135} 1136__setup("fail_page_alloc=", setup_fail_page_alloc); 1137 1138static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1139{ 1140 if (order < fail_page_alloc.min_order) 1141 return 0; 1142 if (gfp_mask & __GFP_NOFAIL) 1143 return 0; 1144 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 1145 return 0; 1146 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) 1147 return 0; 1148 1149 return should_fail(&fail_page_alloc.attr, 1 << order); 1150} 1151 1152#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1153 1154static int __init fail_page_alloc_debugfs(void) 1155{ 1156 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; 1157 struct dentry *dir; 1158 int err; 1159 1160 err = init_fault_attr_dentries(&fail_page_alloc.attr, 1161 "fail_page_alloc"); 1162 if (err) 1163 return err; 1164 dir = fail_page_alloc.attr.dentries.dir; 1165 1166 fail_page_alloc.ignore_gfp_wait_file = 1167 debugfs_create_bool("ignore-gfp-wait", mode, dir, 1168 &fail_page_alloc.ignore_gfp_wait); 1169 1170 fail_page_alloc.ignore_gfp_highmem_file = 1171 debugfs_create_bool("ignore-gfp-highmem", mode, dir, 1172 &fail_page_alloc.ignore_gfp_highmem); 1173 fail_page_alloc.min_order_file = 1174 debugfs_create_u32("min-order", mode, dir, 1175 &fail_page_alloc.min_order); 1176 1177 if (!fail_page_alloc.ignore_gfp_wait_file || 1178 !fail_page_alloc.ignore_gfp_highmem_file || 1179 !fail_page_alloc.min_order_file) { 1180 err = -ENOMEM; 1181 debugfs_remove(fail_page_alloc.ignore_gfp_wait_file); 1182 debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file); 1183 debugfs_remove(fail_page_alloc.min_order_file); 1184 cleanup_fault_attr_dentries(&fail_page_alloc.attr); 1185 } 1186 1187 return err; 1188} 1189 1190late_initcall(fail_page_alloc_debugfs); 1191 1192#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1193 1194#else /* CONFIG_FAIL_PAGE_ALLOC */ 1195 1196static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1197{ 1198 return 0; 1199} 1200 1201#endif /* CONFIG_FAIL_PAGE_ALLOC */ 1202 1203/* 1204 * Return 1 if free pages are above 'mark'. This takes into account the order 1205 * of the allocation. 1206 */ 1207int zone_watermark_ok(struct zone *z, int order, unsigned long mark, 1208 int classzone_idx, int alloc_flags) 1209{ 1210 /* free_pages my go negative - that's OK */ 1211 long min = mark; 1212 long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1; 1213 int o; 1214 1215 if (alloc_flags & ALLOC_HIGH) 1216 min -= min / 2; 1217 if (alloc_flags & ALLOC_HARDER) 1218 min -= min / 4; 1219 1220 if (free_pages <= min + z->lowmem_reserve[classzone_idx]) 1221 return 0; 1222 for (o = 0; o < order; o++) { 1223 /* At the next order, this order's pages become unavailable */ 1224 free_pages -= z->free_area[o].nr_free << o; 1225 1226 /* Require fewer higher order pages to be free */ 1227 min >>= 1; 1228 1229 if (free_pages <= min) 1230 return 0; 1231 } 1232 return 1; 1233} 1234 1235#ifdef CONFIG_NUMA 1236/* 1237 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to 1238 * skip over zones that are not allowed by the cpuset, or that have 1239 * been recently (in last second) found to be nearly full. See further 1240 * comments in mmzone.h. Reduces cache footprint of zonelist scans 1241 * that have to skip over a lot of full or unallowed zones. 1242 * 1243 * If the zonelist cache is present in the passed in zonelist, then 1244 * returns a pointer to the allowed node mask (either the current 1245 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].) 1246 * 1247 * If the zonelist cache is not available for this zonelist, does 1248 * nothing and returns NULL. 1249 * 1250 * If the fullzones BITMAP in the zonelist cache is stale (more than 1251 * a second since last zap'd) then we zap it out (clear its bits.) 1252 * 1253 * We hold off even calling zlc_setup, until after we've checked the 1254 * first zone in the zonelist, on the theory that most allocations will 1255 * be satisfied from that first zone, so best to examine that zone as 1256 * quickly as we can. 1257 */ 1258static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1259{ 1260 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1261 nodemask_t *allowednodes; /* zonelist_cache approximation */ 1262 1263 zlc = zonelist->zlcache_ptr; 1264 if (!zlc) 1265 return NULL; 1266 1267 if (time_after(jiffies, zlc->last_full_zap + HZ)) { 1268 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1269 zlc->last_full_zap = jiffies; 1270 } 1271 1272 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? 1273 &cpuset_current_mems_allowed : 1274 &node_states[N_HIGH_MEMORY]; 1275 return allowednodes; 1276} 1277 1278/* 1279 * Given 'z' scanning a zonelist, run a couple of quick checks to see 1280 * if it is worth looking at further for free memory: 1281 * 1) Check that the zone isn't thought to be full (doesn't have its 1282 * bit set in the zonelist_cache fullzones BITMAP). 1283 * 2) Check that the zones node (obtained from the zonelist_cache 1284 * z_to_n[] mapping) is allowed in the passed in allowednodes mask. 1285 * Return true (non-zero) if zone is worth looking at further, or 1286 * else return false (zero) if it is not. 1287 * 1288 * This check -ignores- the distinction between various watermarks, 1289 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is 1290 * found to be full for any variation of these watermarks, it will 1291 * be considered full for up to one second by all requests, unless 1292 * we are so low on memory on all allowed nodes that we are forced 1293 * into the second scan of the zonelist. 1294 * 1295 * In the second scan we ignore this zonelist cache and exactly 1296 * apply the watermarks to all zones, even it is slower to do so. 1297 * We are low on memory in the second scan, and should leave no stone 1298 * unturned looking for a free page. 1299 */ 1300static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1301 nodemask_t *allowednodes) 1302{ 1303 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1304 int i; /* index of *z in zonelist zones */ 1305 int n; /* node that zone *z is on */ 1306 1307 zlc = zonelist->zlcache_ptr; 1308 if (!zlc) 1309 return 1; 1310 1311 i = z - zonelist->_zonerefs; 1312 n = zlc->z_to_n[i]; 1313 1314 /* This zone is worth trying if it is allowed but not full */ 1315 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); 1316} 1317 1318/* 1319 * Given 'z' scanning a zonelist, set the corresponding bit in 1320 * zlc->fullzones, so that subsequent attempts to allocate a page 1321 * from that zone don't waste time re-examining it. 1322 */ 1323static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1324{ 1325 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1326 int i; /* index of *z in zonelist zones */ 1327 1328 zlc = zonelist->zlcache_ptr; 1329 if (!zlc) 1330 return; 1331 1332 i = z - zonelist->_zonerefs; 1333 1334 set_bit(i, zlc->fullzones); 1335} 1336 1337#else /* CONFIG_NUMA */ 1338 1339static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1340{ 1341 return NULL; 1342} 1343 1344static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1345 nodemask_t *allowednodes) 1346{ 1347 return 1; 1348} 1349 1350static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1351{ 1352} 1353#endif /* CONFIG_NUMA */ 1354 1355/* 1356 * get_page_from_freelist goes through the zonelist trying to allocate 1357 * a page. 1358 */ 1359static struct page * 1360get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order, 1361 struct zonelist *zonelist, int high_zoneidx, int alloc_flags) 1362{ 1363 struct zoneref *z; 1364 struct page *page = NULL; 1365 int classzone_idx; 1366 struct zone *zone, *preferred_zone; 1367 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ 1368 int zlc_active = 0; /* set if using zonelist_cache */ 1369 int did_zlc_setup = 0; /* just call zlc_setup() one time */ 1370 1371 (void)first_zones_zonelist(zonelist, high_zoneidx, nodemask, 1372 &preferred_zone); 1373 if (!preferred_zone) 1374 return NULL; 1375 1376 classzone_idx = zone_idx(preferred_zone); 1377 1378zonelist_scan: 1379 /* 1380 * Scan zonelist, looking for a zone with enough free. 1381 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1382 */ 1383 for_each_zone_zonelist_nodemask(zone, z, zonelist, 1384 high_zoneidx, nodemask) { 1385 if (NUMA_BUILD && zlc_active && 1386 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 1387 continue; 1388 if ((alloc_flags & ALLOC_CPUSET) && 1389 !cpuset_zone_allowed_softwall(zone, gfp_mask)) 1390 goto try_next_zone; 1391 1392 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { 1393 unsigned long mark; 1394 if (alloc_flags & ALLOC_WMARK_MIN) 1395 mark = zone->pages_min; 1396 else if (alloc_flags & ALLOC_WMARK_LOW) 1397 mark = zone->pages_low; 1398 else 1399 mark = zone->pages_high; 1400 if (!zone_watermark_ok(zone, order, mark, 1401 classzone_idx, alloc_flags)) { 1402 if (!zone_reclaim_mode || 1403 !zone_reclaim(zone, gfp_mask, order)) 1404 goto this_zone_full; 1405 } 1406 } 1407 1408 page = buffered_rmqueue(preferred_zone, zone, order, gfp_mask); 1409 if (page) 1410 break; 1411this_zone_full: 1412 if (NUMA_BUILD) 1413 zlc_mark_zone_full(zonelist, z); 1414try_next_zone: 1415 if (NUMA_BUILD && !did_zlc_setup) { 1416 /* we do zlc_setup after the first zone is tried */ 1417 allowednodes = zlc_setup(zonelist, alloc_flags); 1418 zlc_active = 1; 1419 did_zlc_setup = 1; 1420 } 1421 } 1422 1423 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) { 1424 /* Disable zlc cache for second zonelist scan */ 1425 zlc_active = 0; 1426 goto zonelist_scan; 1427 } 1428 return page; 1429} 1430 1431/* 1432 * This is the 'heart' of the zoned buddy allocator. 1433 */ 1434struct page * 1435__alloc_pages_internal(gfp_t gfp_mask, unsigned int order, 1436 struct zonelist *zonelist, nodemask_t *nodemask) 1437{ 1438 const gfp_t wait = gfp_mask & __GFP_WAIT; 1439 enum zone_type high_zoneidx = gfp_zone(gfp_mask); 1440 struct zoneref *z; 1441 struct zone *zone; 1442 struct page *page; 1443 struct reclaim_state reclaim_state; 1444 struct task_struct *p = current; 1445 int do_retry; 1446 int alloc_flags; 1447 unsigned long did_some_progress; 1448 unsigned long pages_reclaimed = 0; 1449 1450 might_sleep_if(wait); 1451 1452 if (should_fail_alloc_page(gfp_mask, order)) 1453 return NULL; 1454 1455restart: 1456 z = zonelist->_zonerefs; /* the list of zones suitable for gfp_mask */ 1457 1458 if (unlikely(!z->zone)) { 1459 /* 1460 * Happens if we have an empty zonelist as a result of 1461 * GFP_THISNODE being used on a memoryless node 1462 */ 1463 return NULL; 1464 } 1465 1466 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order, 1467 zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET); 1468 if (page) 1469 goto got_pg; 1470 1471 /* 1472 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and 1473 * __GFP_NOWARN set) should not cause reclaim since the subsystem 1474 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim 1475 * using a larger set of nodes after it has established that the 1476 * allowed per node queues are empty and that nodes are 1477 * over allocated. 1478 */ 1479 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) 1480 goto nopage; 1481 1482 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) 1483 wakeup_kswapd(zone, order); 1484 1485 /* 1486 * OK, we're below the kswapd watermark and have kicked background 1487 * reclaim. Now things get more complex, so set up alloc_flags according 1488 * to how we want to proceed. 1489 * 1490 * The caller may dip into page reserves a bit more if the caller 1491 * cannot run direct reclaim, or if the caller has realtime scheduling 1492 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will 1493 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). 1494 */ 1495 alloc_flags = ALLOC_WMARK_MIN; 1496 if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait) 1497 alloc_flags |= ALLOC_HARDER; 1498 if (gfp_mask & __GFP_HIGH) 1499 alloc_flags |= ALLOC_HIGH; 1500 if (wait) 1501 alloc_flags |= ALLOC_CPUSET; 1502 1503 /* 1504 * Go through the zonelist again. Let __GFP_HIGH and allocations 1505 * coming from realtime tasks go deeper into reserves. 1506 * 1507 * This is the last chance, in general, before the goto nopage. 1508 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. 1509 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1510 */ 1511 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, 1512 high_zoneidx, alloc_flags); 1513 if (page) 1514 goto got_pg; 1515 1516 /* This allocation should allow future memory freeing. */ 1517 1518rebalance: 1519 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) 1520 && !in_interrupt()) { 1521 if (!(gfp_mask & __GFP_NOMEMALLOC)) { 1522nofail_alloc: 1523 /* go through the zonelist yet again, ignoring mins */ 1524 page = get_page_from_freelist(gfp_mask, nodemask, order, 1525 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS); 1526 if (page) 1527 goto got_pg; 1528 if (gfp_mask & __GFP_NOFAIL) { 1529 congestion_wait(WRITE, HZ/50); 1530 goto nofail_alloc; 1531 } 1532 } 1533 goto nopage; 1534 } 1535 1536 /* Atomic allocations - we can't balance anything */ 1537 if (!wait) 1538 goto nopage; 1539 1540 cond_resched(); 1541 1542 /* We now go into synchronous reclaim */ 1543 cpuset_memory_pressure_bump(); 1544 p->flags |= PF_MEMALLOC; 1545 reclaim_state.reclaimed_slab = 0; 1546 p->reclaim_state = &reclaim_state; 1547 1548 did_some_progress = try_to_free_pages(zonelist, order, gfp_mask); 1549 1550 p->reclaim_state = NULL; 1551 p->flags &= ~PF_MEMALLOC; 1552 1553 cond_resched(); 1554 1555 if (order != 0) 1556 drain_all_pages(); 1557 1558 if (likely(did_some_progress)) { 1559 page = get_page_from_freelist(gfp_mask, nodemask, order, 1560 zonelist, high_zoneidx, alloc_flags); 1561 if (page) 1562 goto got_pg; 1563 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { 1564 if (!try_set_zone_oom(zonelist, gfp_mask)) { 1565 schedule_timeout_uninterruptible(1); 1566 goto restart; 1567 } 1568 1569 /* 1570 * Go through the zonelist yet one more time, keep 1571 * very high watermark here, this is only to catch 1572 * a parallel oom killing, we must fail if we're still 1573 * under heavy pressure. 1574 */ 1575 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, 1576 order, zonelist, high_zoneidx, 1577 ALLOC_WMARK_HIGH|ALLOC_CPUSET); 1578 if (page) { 1579 clear_zonelist_oom(zonelist, gfp_mask); 1580 goto got_pg; 1581 } 1582 1583 /* The OOM killer will not help higher order allocs so fail */ 1584 if (order > PAGE_ALLOC_COSTLY_ORDER) { 1585 clear_zonelist_oom(zonelist, gfp_mask); 1586 goto nopage; 1587 } 1588 1589 out_of_memory(zonelist, gfp_mask, order); 1590 clear_zonelist_oom(zonelist, gfp_mask); 1591 goto restart; 1592 } 1593 1594 /* 1595 * Don't let big-order allocations loop unless the caller explicitly 1596 * requests that. Wait for some write requests to complete then retry. 1597 * 1598 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER 1599 * means __GFP_NOFAIL, but that may not be true in other 1600 * implementations. 1601 * 1602 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is 1603 * specified, then we retry until we no longer reclaim any pages 1604 * (above), or we've reclaimed an order of pages at least as 1605 * large as the allocation's order. In both cases, if the 1606 * allocation still fails, we stop retrying. 1607 */ 1608 pages_reclaimed += did_some_progress; 1609 do_retry = 0; 1610 if (!(gfp_mask & __GFP_NORETRY)) { 1611 if (order <= PAGE_ALLOC_COSTLY_ORDER) { 1612 do_retry = 1; 1613 } else { 1614 if (gfp_mask & __GFP_REPEAT && 1615 pages_reclaimed < (1 << order)) 1616 do_retry = 1; 1617 } 1618 if (gfp_mask & __GFP_NOFAIL) 1619 do_retry = 1; 1620 } 1621 if (do_retry) { 1622 congestion_wait(WRITE, HZ/50); 1623 goto rebalance; 1624 } 1625 1626nopage: 1627 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { 1628 printk(KERN_WARNING "%s: page allocation failure." 1629 " order:%d, mode:0x%x\n", 1630 p->comm, order, gfp_mask); 1631 dump_stack(); 1632 show_mem(); 1633 } 1634got_pg: 1635 return page; 1636} 1637EXPORT_SYMBOL(__alloc_pages_internal); 1638 1639/* 1640 * Common helper functions. 1641 */ 1642unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 1643{ 1644 struct page * page; 1645 page = alloc_pages(gfp_mask, order); 1646 if (!page) 1647 return 0; 1648 return (unsigned long) page_address(page); 1649} 1650 1651EXPORT_SYMBOL(__get_free_pages); 1652 1653unsigned long get_zeroed_page(gfp_t gfp_mask) 1654{ 1655 struct page * page; 1656 1657 /* 1658 * get_zeroed_page() returns a 32-bit address, which cannot represent 1659 * a highmem page 1660 */ 1661 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 1662 1663 page = alloc_pages(gfp_mask | __GFP_ZERO, 0); 1664 if (page) 1665 return (unsigned long) page_address(page); 1666 return 0; 1667} 1668 1669EXPORT_SYMBOL(get_zeroed_page); 1670 1671void __pagevec_free(struct pagevec *pvec) 1672{ 1673 int i = pagevec_count(pvec); 1674 1675 while (--i >= 0) 1676 free_hot_cold_page(pvec->pages[i], pvec->cold); 1677} 1678 1679void __free_pages(struct page *page, unsigned int order) 1680{ 1681 if (put_page_testzero(page)) { 1682 if (order == 0) 1683 free_hot_page(page); 1684 else 1685 __free_pages_ok(page, order); 1686 } 1687} 1688 1689EXPORT_SYMBOL(__free_pages); 1690 1691void free_pages(unsigned long addr, unsigned int order) 1692{ 1693 if (addr != 0) { 1694 VM_BUG_ON(!virt_addr_valid((void *)addr)); 1695 __free_pages(virt_to_page((void *)addr), order); 1696 } 1697} 1698 1699EXPORT_SYMBOL(free_pages); 1700 1701/** 1702 * alloc_pages_exact - allocate an exact number physically-contiguous pages. 1703 * @size: the number of bytes to allocate 1704 * @gfp_mask: GFP flags for the allocation 1705 * 1706 * This function is similar to alloc_pages(), except that it allocates the 1707 * minimum number of pages to satisfy the request. alloc_pages() can only 1708 * allocate memory in power-of-two pages. 1709 * 1710 * This function is also limited by MAX_ORDER. 1711 * 1712 * Memory allocated by this function must be released by free_pages_exact(). 1713 */ 1714void *alloc_pages_exact(size_t size, gfp_t gfp_mask) 1715{ 1716 unsigned int order = get_order(size); 1717 unsigned long addr; 1718 1719 addr = __get_free_pages(gfp_mask, order); 1720 if (addr) { 1721 unsigned long alloc_end = addr + (PAGE_SIZE << order); 1722 unsigned long used = addr + PAGE_ALIGN(size); 1723 1724 split_page(virt_to_page(addr), order); 1725 while (used < alloc_end) { 1726 free_page(used); 1727 used += PAGE_SIZE; 1728 } 1729 } 1730 1731 return (void *)addr; 1732} 1733EXPORT_SYMBOL(alloc_pages_exact); 1734 1735/** 1736 * free_pages_exact - release memory allocated via alloc_pages_exact() 1737 * @virt: the value returned by alloc_pages_exact. 1738 * @size: size of allocation, same value as passed to alloc_pages_exact(). 1739 * 1740 * Release the memory allocated by a previous call to alloc_pages_exact. 1741 */ 1742void free_pages_exact(void *virt, size_t size) 1743{ 1744 unsigned long addr = (unsigned long)virt; 1745 unsigned long end = addr + PAGE_ALIGN(size); 1746 1747 while (addr < end) { 1748 free_page(addr); 1749 addr += PAGE_SIZE; 1750 } 1751} 1752EXPORT_SYMBOL(free_pages_exact); 1753 1754static unsigned int nr_free_zone_pages(int offset) 1755{ 1756 struct zoneref *z; 1757 struct zone *zone; 1758 1759 /* Just pick one node, since fallback list is circular */ 1760 unsigned int sum = 0; 1761 1762 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); 1763 1764 for_each_zone_zonelist(zone, z, zonelist, offset) { 1765 unsigned long size = zone->present_pages; 1766 unsigned long high = zone->pages_high; 1767 if (size > high) 1768 sum += size - high; 1769 } 1770 1771 return sum; 1772} 1773 1774/* 1775 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL 1776 */ 1777unsigned int nr_free_buffer_pages(void) 1778{ 1779 return nr_free_zone_pages(gfp_zone(GFP_USER)); 1780} 1781EXPORT_SYMBOL_GPL(nr_free_buffer_pages); 1782 1783/* 1784 * Amount of free RAM allocatable within all zones 1785 */ 1786unsigned int nr_free_pagecache_pages(void) 1787{ 1788 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); 1789} 1790 1791static inline void show_node(struct zone *zone) 1792{ 1793 if (NUMA_BUILD) 1794 printk("Node %d ", zone_to_nid(zone)); 1795} 1796 1797void si_meminfo(struct sysinfo *val) 1798{ 1799 val->totalram = totalram_pages; 1800 val->sharedram = 0; 1801 val->freeram = global_page_state(NR_FREE_PAGES); 1802 val->bufferram = nr_blockdev_pages(); 1803 val->totalhigh = totalhigh_pages; 1804 val->freehigh = nr_free_highpages(); 1805 val->mem_unit = PAGE_SIZE; 1806} 1807 1808EXPORT_SYMBOL(si_meminfo); 1809 1810#ifdef CONFIG_NUMA 1811void si_meminfo_node(struct sysinfo *val, int nid) 1812{ 1813 pg_data_t *pgdat = NODE_DATA(nid); 1814 1815 val->totalram = pgdat->node_present_pages; 1816 val->freeram = node_page_state(nid, NR_FREE_PAGES); 1817#ifdef CONFIG_HIGHMEM 1818 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; 1819 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], 1820 NR_FREE_PAGES); 1821#else 1822 val->totalhigh = 0; 1823 val->freehigh = 0; 1824#endif 1825 val->mem_unit = PAGE_SIZE; 1826} 1827#endif 1828 1829#define K(x) ((x) << (PAGE_SHIFT-10)) 1830 1831/* 1832 * Show free area list (used inside shift_scroll-lock stuff) 1833 * We also calculate the percentage fragmentation. We do this by counting the 1834 * memory on each free list with the exception of the first item on the list. 1835 */ 1836void show_free_areas(void) 1837{ 1838 int cpu; 1839 struct zone *zone; 1840 1841 for_each_zone(zone) { 1842 if (!populated_zone(zone)) 1843 continue; 1844 1845 show_node(zone); 1846 printk("%s per-cpu:\n", zone->name); 1847 1848 for_each_online_cpu(cpu) { 1849 struct per_cpu_pageset *pageset; 1850 1851 pageset = zone_pcp(zone, cpu); 1852 1853 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n", 1854 cpu, pageset->pcp.high, 1855 pageset->pcp.batch, pageset->pcp.count); 1856 } 1857 } 1858 1859 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu\n" 1860 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n", 1861 global_page_state(NR_ACTIVE), 1862 global_page_state(NR_INACTIVE), 1863 global_page_state(NR_FILE_DIRTY), 1864 global_page_state(NR_WRITEBACK), 1865 global_page_state(NR_UNSTABLE_NFS), 1866 global_page_state(NR_FREE_PAGES), 1867 global_page_state(NR_SLAB_RECLAIMABLE) + 1868 global_page_state(NR_SLAB_UNRECLAIMABLE), 1869 global_page_state(NR_FILE_MAPPED), 1870 global_page_state(NR_PAGETABLE), 1871 global_page_state(NR_BOUNCE)); 1872 1873 for_each_zone(zone) { 1874 int i; 1875 1876 if (!populated_zone(zone)) 1877 continue; 1878 1879 show_node(zone); 1880 printk("%s" 1881 " free:%lukB" 1882 " min:%lukB" 1883 " low:%lukB" 1884 " high:%lukB" 1885 " active:%lukB" 1886 " inactive:%lukB" 1887 " present:%lukB" 1888 " pages_scanned:%lu" 1889 " all_unreclaimable? %s" 1890 "\n", 1891 zone->name, 1892 K(zone_page_state(zone, NR_FREE_PAGES)), 1893 K(zone->pages_min), 1894 K(zone->pages_low), 1895 K(zone->pages_high), 1896 K(zone_page_state(zone, NR_ACTIVE)), 1897 K(zone_page_state(zone, NR_INACTIVE)), 1898 K(zone->present_pages), 1899 zone->pages_scanned, 1900 (zone_is_all_unreclaimable(zone) ? "yes" : "no") 1901 ); 1902 printk("lowmem_reserve[]:"); 1903 for (i = 0; i < MAX_NR_ZONES; i++) 1904 printk(" %lu", zone->lowmem_reserve[i]); 1905 printk("\n"); 1906 } 1907 1908 for_each_zone(zone) { 1909 unsigned long nr[MAX_ORDER], flags, order, total = 0; 1910 1911 if (!populated_zone(zone)) 1912 continue; 1913 1914 show_node(zone); 1915 printk("%s: ", zone->name); 1916 1917 spin_lock_irqsave(&zone->lock, flags); 1918 for (order = 0; order < MAX_ORDER; order++) { 1919 nr[order] = zone->free_area[order].nr_free; 1920 total += nr[order] << order; 1921 } 1922 spin_unlock_irqrestore(&zone->lock, flags); 1923 for (order = 0; order < MAX_ORDER; order++) 1924 printk("%lu*%lukB ", nr[order], K(1UL) << order); 1925 printk("= %lukB\n", K(total)); 1926 } 1927 1928 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES)); 1929 1930 show_swap_cache_info(); 1931} 1932 1933static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) 1934{ 1935 zoneref->zone = zone; 1936 zoneref->zone_idx = zone_idx(zone); 1937} 1938 1939/* 1940 * Builds allocation fallback zone lists. 1941 * 1942 * Add all populated zones of a node to the zonelist. 1943 */ 1944static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, 1945 int nr_zones, enum zone_type zone_type) 1946{ 1947 struct zone *zone; 1948 1949 BUG_ON(zone_type >= MAX_NR_ZONES); 1950 zone_type++; 1951 1952 do { 1953 zone_type--; 1954 zone = pgdat->node_zones + zone_type; 1955 if (populated_zone(zone)) { 1956 zoneref_set_zone(zone, 1957 &zonelist->_zonerefs[nr_zones++]); 1958 check_highest_zone(zone_type); 1959 } 1960 1961 } while (zone_type); 1962 return nr_zones; 1963} 1964 1965 1966/* 1967 * zonelist_order: 1968 * 0 = automatic detection of better ordering. 1969 * 1 = order by ([node] distance, -zonetype) 1970 * 2 = order by (-zonetype, [node] distance) 1971 * 1972 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create 1973 * the same zonelist. So only NUMA can configure this param. 1974 */ 1975#define ZONELIST_ORDER_DEFAULT 0 1976#define ZONELIST_ORDER_NODE 1 1977#define ZONELIST_ORDER_ZONE 2 1978 1979/* zonelist order in the kernel. 1980 * set_zonelist_order() will set this to NODE or ZONE. 1981 */ 1982static int current_zonelist_order = ZONELIST_ORDER_DEFAULT; 1983static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"}; 1984 1985 1986#ifdef CONFIG_NUMA 1987/* The value user specified ....changed by config */ 1988static int user_zonelist_order = ZONELIST_ORDER_DEFAULT; 1989/* string for sysctl */ 1990#define NUMA_ZONELIST_ORDER_LEN 16 1991char numa_zonelist_order[16] = "default"; 1992 1993/* 1994 * interface for configure zonelist ordering. 1995 * command line option "numa_zonelist_order" 1996 * = "[dD]efault - default, automatic configuration. 1997 * = "[nN]ode - order by node locality, then by zone within node 1998 * = "[zZ]one - order by zone, then by locality within zone 1999 */ 2000 2001static int __parse_numa_zonelist_order(char *s) 2002{ 2003 if (*s == 'd' || *s == 'D') { 2004 user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2005 } else if (*s == 'n' || *s == 'N') { 2006 user_zonelist_order = ZONELIST_ORDER_NODE; 2007 } else if (*s == 'z' || *s == 'Z') { 2008 user_zonelist_order = ZONELIST_ORDER_ZONE; 2009 } else { 2010 printk(KERN_WARNING 2011 "Ignoring invalid numa_zonelist_order value: " 2012 "%s\n", s); 2013 return -EINVAL; 2014 } 2015 return 0; 2016} 2017 2018static __init int setup_numa_zonelist_order(char *s) 2019{ 2020 if (s) 2021 return __parse_numa_zonelist_order(s); 2022 return 0; 2023} 2024early_param("numa_zonelist_order", setup_numa_zonelist_order); 2025 2026/* 2027 * sysctl handler for numa_zonelist_order 2028 */ 2029int numa_zonelist_order_handler(ctl_table *table, int write, 2030 struct file *file, void __user *buffer, size_t *length, 2031 loff_t *ppos) 2032{ 2033 char saved_string[NUMA_ZONELIST_ORDER_LEN]; 2034 int ret; 2035 2036 if (write) 2037 strncpy(saved_string, (char*)table->data, 2038 NUMA_ZONELIST_ORDER_LEN); 2039 ret = proc_dostring(table, write, file, buffer, length, ppos); 2040 if (ret) 2041 return ret; 2042 if (write) { 2043 int oldval = user_zonelist_order; 2044 if (__parse_numa_zonelist_order((char*)table->data)) { 2045 /* 2046 * bogus value. restore saved string 2047 */ 2048 strncpy((char*)table->data, saved_string, 2049 NUMA_ZONELIST_ORDER_LEN); 2050 user_zonelist_order = oldval; 2051 } else if (oldval != user_zonelist_order) 2052 build_all_zonelists(); 2053 } 2054 return 0; 2055} 2056 2057 2058#define MAX_NODE_LOAD (num_online_nodes()) 2059static int node_load[MAX_NUMNODES]; 2060 2061/** 2062 * find_next_best_node - find the next node that should appear in a given node's fallback list 2063 * @node: node whose fallback list we're appending 2064 * @used_node_mask: nodemask_t of already used nodes 2065 * 2066 * We use a number of factors to determine which is the next node that should 2067 * appear on a given node's fallback list. The node should not have appeared 2068 * already in @node's fallback list, and it should be the next closest node 2069 * according to the distance array (which contains arbitrary distance values 2070 * from each node to each node in the system), and should also prefer nodes 2071 * with no CPUs, since presumably they'll have very little allocation pressure 2072 * on them otherwise. 2073 * It returns -1 if no node is found. 2074 */ 2075static int find_next_best_node(int node, nodemask_t *used_node_mask) 2076{ 2077 int n, val; 2078 int min_val = INT_MAX; 2079 int best_node = -1; 2080 node_to_cpumask_ptr(tmp, 0); 2081 2082 /* Use the local node if we haven't already */ 2083 if (!node_isset(node, *used_node_mask)) { 2084 node_set(node, *used_node_mask); 2085 return node; 2086 } 2087 2088 for_each_node_state(n, N_HIGH_MEMORY) { 2089 2090 /* Don't want a node to appear more than once */ 2091 if (node_isset(n, *used_node_mask)) 2092 continue; 2093 2094 /* Use the distance array to find the distance */ 2095 val = node_distance(node, n); 2096 2097 /* Penalize nodes under us ("prefer the next node") */ 2098 val += (n < node); 2099 2100 /* Give preference to headless and unused nodes */ 2101 node_to_cpumask_ptr_next(tmp, n); 2102 if (!cpus_empty(*tmp)) 2103 val += PENALTY_FOR_NODE_WITH_CPUS; 2104 2105 /* Slight preference for less loaded node */ 2106 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 2107 val += node_load[n]; 2108 2109 if (val < min_val) { 2110 min_val = val; 2111 best_node = n; 2112 } 2113 } 2114 2115 if (best_node >= 0) 2116 node_set(best_node, *used_node_mask); 2117 2118 return best_node; 2119} 2120 2121 2122/* 2123 * Build zonelists ordered by node and zones within node. 2124 * This results in maximum locality--normal zone overflows into local 2125 * DMA zone, if any--but risks exhausting DMA zone. 2126 */ 2127static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) 2128{ 2129 int j; 2130 struct zonelist *zonelist; 2131 2132 zonelist = &pgdat->node_zonelists[0]; 2133 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++) 2134 ; 2135 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2136 MAX_NR_ZONES - 1); 2137 zonelist->_zonerefs[j].zone = NULL; 2138 zonelist->_zonerefs[j].zone_idx = 0; 2139} 2140 2141/* 2142 * Build gfp_thisnode zonelists 2143 */ 2144static void build_thisnode_zonelists(pg_data_t *pgdat) 2145{ 2146 int j; 2147 struct zonelist *zonelist; 2148 2149 zonelist = &pgdat->node_zonelists[1]; 2150 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2151 zonelist->_zonerefs[j].zone = NULL; 2152 zonelist->_zonerefs[j].zone_idx = 0; 2153} 2154 2155/* 2156 * Build zonelists ordered by zone and nodes within zones. 2157 * This results in conserving DMA zone[s] until all Normal memory is 2158 * exhausted, but results in overflowing to remote node while memory 2159 * may still exist in local DMA zone. 2160 */ 2161static int node_order[MAX_NUMNODES]; 2162 2163static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) 2164{ 2165 int pos, j, node; 2166 int zone_type; /* needs to be signed */ 2167 struct zone *z; 2168 struct zonelist *zonelist; 2169 2170 zonelist = &pgdat->node_zonelists[0]; 2171 pos = 0; 2172 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) { 2173 for (j = 0; j < nr_nodes; j++) { 2174 node = node_order[j]; 2175 z = &NODE_DATA(node)->node_zones[zone_type]; 2176 if (populated_zone(z)) { 2177 zoneref_set_zone(z, 2178 &zonelist->_zonerefs[pos++]); 2179 check_highest_zone(zone_type); 2180 } 2181 } 2182 } 2183 zonelist->_zonerefs[pos].zone = NULL; 2184 zonelist->_zonerefs[pos].zone_idx = 0; 2185} 2186 2187static int default_zonelist_order(void) 2188{ 2189 int nid, zone_type; 2190 unsigned long low_kmem_size,total_size; 2191 struct zone *z; 2192 int average_size; 2193 /* 2194 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem. 2195 * If they are really small and used heavily, the system can fall 2196 * into OOM very easily. 2197 * This function detect ZONE_DMA/DMA32 size and confgigures zone order. 2198 */ 2199 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */ 2200 low_kmem_size = 0; 2201 total_size = 0; 2202 for_each_online_node(nid) { 2203 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2204 z = &NODE_DATA(nid)->node_zones[zone_type]; 2205 if (populated_zone(z)) { 2206 if (zone_type < ZONE_NORMAL) 2207 low_kmem_size += z->present_pages; 2208 total_size += z->present_pages; 2209 } 2210 } 2211 } 2212 if (!low_kmem_size || /* there are no DMA area. */ 2213 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */ 2214 return ZONELIST_ORDER_NODE; 2215 /* 2216 * look into each node's config. 2217 * If there is a node whose DMA/DMA32 memory is very big area on 2218 * local memory, NODE_ORDER may be suitable. 2219 */ 2220 average_size = total_size / 2221 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1); 2222 for_each_online_node(nid) { 2223 low_kmem_size = 0; 2224 total_size = 0; 2225 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2226 z = &NODE_DATA(nid)->node_zones[zone_type]; 2227 if (populated_zone(z)) { 2228 if (zone_type < ZONE_NORMAL) 2229 low_kmem_size += z->present_pages; 2230 total_size += z->present_pages; 2231 } 2232 } 2233 if (low_kmem_size && 2234 total_size > average_size && /* ignore small node */ 2235 low_kmem_size > total_size * 70/100) 2236 return ZONELIST_ORDER_NODE; 2237 } 2238 return ZONELIST_ORDER_ZONE; 2239} 2240 2241static void set_zonelist_order(void) 2242{ 2243 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT) 2244 current_zonelist_order = default_zonelist_order(); 2245 else 2246 current_zonelist_order = user_zonelist_order; 2247} 2248 2249static void build_zonelists(pg_data_t *pgdat) 2250{ 2251 int j, node, load; 2252 enum zone_type i; 2253 nodemask_t used_mask; 2254 int local_node, prev_node; 2255 struct zonelist *zonelist; 2256 int order = current_zonelist_order; 2257 2258 /* initialize zonelists */ 2259 for (i = 0; i < MAX_ZONELISTS; i++) { 2260 zonelist = pgdat->node_zonelists + i; 2261 zonelist->_zonerefs[0].zone = NULL; 2262 zonelist->_zonerefs[0].zone_idx = 0; 2263 } 2264 2265 /* NUMA-aware ordering of nodes */ 2266 local_node = pgdat->node_id; 2267 load = num_online_nodes(); 2268 prev_node = local_node; 2269 nodes_clear(used_mask); 2270 2271 memset(node_load, 0, sizeof(node_load)); 2272 memset(node_order, 0, sizeof(node_order)); 2273 j = 0; 2274 2275 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 2276 int distance = node_distance(local_node, node); 2277 2278 /* 2279 * If another node is sufficiently far away then it is better 2280 * to reclaim pages in a zone before going off node. 2281 */ 2282 if (distance > RECLAIM_DISTANCE) 2283 zone_reclaim_mode = 1; 2284 2285 /* 2286 * We don't want to pressure a particular node. 2287 * So adding penalty to the first node in same 2288 * distance group to make it round-robin. 2289 */ 2290 if (distance != node_distance(local_node, prev_node)) 2291 node_load[node] = load; 2292 2293 prev_node = node; 2294 load--; 2295 if (order == ZONELIST_ORDER_NODE) 2296 build_zonelists_in_node_order(pgdat, node); 2297 else 2298 node_order[j++] = node; /* remember order */ 2299 } 2300 2301 if (order == ZONELIST_ORDER_ZONE) { 2302 /* calculate node order -- i.e., DMA last! */ 2303 build_zonelists_in_zone_order(pgdat, j); 2304 } 2305 2306 build_thisnode_zonelists(pgdat); 2307} 2308 2309/* Construct the zonelist performance cache - see further mmzone.h */ 2310static void build_zonelist_cache(pg_data_t *pgdat) 2311{ 2312 struct zonelist *zonelist; 2313 struct zonelist_cache *zlc; 2314 struct zoneref *z; 2315 2316 zonelist = &pgdat->node_zonelists[0]; 2317 zonelist->zlcache_ptr = zlc = &zonelist->zlcache; 2318 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 2319 for (z = zonelist->_zonerefs; z->zone; z++) 2320 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z); 2321} 2322 2323 2324#else /* CONFIG_NUMA */ 2325 2326static void set_zonelist_order(void) 2327{ 2328 current_zonelist_order = ZONELIST_ORDER_ZONE; 2329} 2330 2331static void build_zonelists(pg_data_t *pgdat) 2332{ 2333 int node, local_node; 2334 enum zone_type j; 2335 struct zonelist *zonelist; 2336 2337 local_node = pgdat->node_id; 2338 2339 zonelist = &pgdat->node_zonelists[0]; 2340 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2341 2342 /* 2343 * Now we build the zonelist so that it contains the zones 2344 * of all the other nodes. 2345 * We don't want to pressure a particular node, so when 2346 * building the zones for node N, we make sure that the 2347 * zones coming right after the local ones are those from 2348 * node N+1 (modulo N) 2349 */ 2350 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 2351 if (!node_online(node)) 2352 continue; 2353 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2354 MAX_NR_ZONES - 1); 2355 } 2356 for (node = 0; node < local_node; node++) { 2357 if (!node_online(node)) 2358 continue; 2359 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2360 MAX_NR_ZONES - 1); 2361 } 2362 2363 zonelist->_zonerefs[j].zone = NULL; 2364 zonelist->_zonerefs[j].zone_idx = 0; 2365} 2366 2367/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ 2368static void build_zonelist_cache(pg_data_t *pgdat) 2369{ 2370 pgdat->node_zonelists[0].zlcache_ptr = NULL; 2371} 2372 2373#endif /* CONFIG_NUMA */ 2374 2375/* return values int ....just for stop_machine() */ 2376static int __build_all_zonelists(void *dummy) 2377{ 2378 int nid; 2379 2380 for_each_online_node(nid) { 2381 pg_data_t *pgdat = NODE_DATA(nid); 2382 2383 build_zonelists(pgdat); 2384 build_zonelist_cache(pgdat); 2385 } 2386 return 0; 2387} 2388 2389void build_all_zonelists(void) 2390{ 2391 set_zonelist_order(); 2392 2393 if (system_state == SYSTEM_BOOTING) { 2394 __build_all_zonelists(NULL); 2395 mminit_verify_zonelist(); 2396 cpuset_init_current_mems_allowed(); 2397 } else { 2398 /* we have to stop all cpus to guarantee there is no user 2399 of zonelist */ 2400 stop_machine(__build_all_zonelists, NULL, NULL); 2401 /* cpuset refresh routine should be here */ 2402 } 2403 vm_total_pages = nr_free_pagecache_pages(); 2404 /* 2405 * Disable grouping by mobility if the number of pages in the 2406 * system is too low to allow the mechanism to work. It would be 2407 * more accurate, but expensive to check per-zone. This check is 2408 * made on memory-hotadd so a system can start with mobility 2409 * disabled and enable it later 2410 */ 2411 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) 2412 page_group_by_mobility_disabled = 1; 2413 else 2414 page_group_by_mobility_disabled = 0; 2415 2416 printk("Built %i zonelists in %s order, mobility grouping %s. " 2417 "Total pages: %ld\n", 2418 num_online_nodes(), 2419 zonelist_order_name[current_zonelist_order], 2420 page_group_by_mobility_disabled ? "off" : "on", 2421 vm_total_pages); 2422#ifdef CONFIG_NUMA 2423 printk("Policy zone: %s\n", zone_names[policy_zone]); 2424#endif 2425} 2426 2427/* 2428 * Helper functions to size the waitqueue hash table. 2429 * Essentially these want to choose hash table sizes sufficiently 2430 * large so that collisions trying to wait on pages are rare. 2431 * But in fact, the number of active page waitqueues on typical 2432 * systems is ridiculously low, less than 200. So this is even 2433 * conservative, even though it seems large. 2434 * 2435 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 2436 * waitqueues, i.e. the size of the waitq table given the number of pages. 2437 */ 2438#define PAGES_PER_WAITQUEUE 256 2439 2440#ifndef CONFIG_MEMORY_HOTPLUG 2441static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2442{ 2443 unsigned long size = 1; 2444 2445 pages /= PAGES_PER_WAITQUEUE; 2446 2447 while (size < pages) 2448 size <<= 1; 2449 2450 /* 2451 * Once we have dozens or even hundreds of threads sleeping 2452 * on IO we've got bigger problems than wait queue collision. 2453 * Limit the size of the wait table to a reasonable size. 2454 */ 2455 size = min(size, 4096UL); 2456 2457 return max(size, 4UL); 2458} 2459#else 2460/* 2461 * A zone's size might be changed by hot-add, so it is not possible to determine 2462 * a suitable size for its wait_table. So we use the maximum size now. 2463 * 2464 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: 2465 * 2466 * i386 (preemption config) : 4096 x 16 = 64Kbyte. 2467 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. 2468 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. 2469 * 2470 * The maximum entries are prepared when a zone's memory is (512K + 256) pages 2471 * or more by the traditional way. (See above). It equals: 2472 * 2473 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. 2474 * ia64(16K page size) : = ( 8G + 4M)byte. 2475 * powerpc (64K page size) : = (32G +16M)byte. 2476 */ 2477static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2478{ 2479 return 4096UL; 2480} 2481#endif 2482 2483/* 2484 * This is an integer logarithm so that shifts can be used later 2485 * to extract the more random high bits from the multiplicative 2486 * hash function before the remainder is taken. 2487 */ 2488static inline unsigned long wait_table_bits(unsigned long size) 2489{ 2490 return ffz(~size); 2491} 2492 2493#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) 2494 2495/* 2496 * Mark a number of pageblocks as MIGRATE_RESERVE. The number 2497 * of blocks reserved is based on zone->pages_min. The memory within the 2498 * reserve will tend to store contiguous free pages. Setting min_free_kbytes 2499 * higher will lead to a bigger reserve which will get freed as contiguous 2500 * blocks as reclaim kicks in 2501 */ 2502static void setup_zone_migrate_reserve(struct zone *zone) 2503{ 2504 unsigned long start_pfn, pfn, end_pfn; 2505 struct page *page; 2506 unsigned long reserve, block_migratetype; 2507 2508 /* Get the start pfn, end pfn and the number of blocks to reserve */ 2509 start_pfn = zone->zone_start_pfn; 2510 end_pfn = start_pfn + zone->spanned_pages; 2511 reserve = roundup(zone->pages_min, pageblock_nr_pages) >> 2512 pageblock_order; 2513 2514 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 2515 if (!pfn_valid(pfn)) 2516 continue; 2517 page = pfn_to_page(pfn); 2518 2519 /* Blocks with reserved pages will never free, skip them. */ 2520 if (PageReserved(page)) 2521 continue; 2522 2523 block_migratetype = get_pageblock_migratetype(page); 2524 2525 /* If this block is reserved, account for it */ 2526 if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) { 2527 reserve--; 2528 continue; 2529 } 2530 2531 /* Suitable for reserving if this block is movable */ 2532 if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) { 2533 set_pageblock_migratetype(page, MIGRATE_RESERVE); 2534 move_freepages_block(zone, page, MIGRATE_RESERVE); 2535 reserve--; 2536 continue; 2537 } 2538 2539 /* 2540 * If the reserve is met and this is a previous reserved block, 2541 * take it back 2542 */ 2543 if (block_migratetype == MIGRATE_RESERVE) { 2544 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 2545 move_freepages_block(zone, page, MIGRATE_MOVABLE); 2546 } 2547 } 2548} 2549 2550/* 2551 * Initially all pages are reserved - free ones are freed 2552 * up by free_all_bootmem() once the early boot process is 2553 * done. Non-atomic initialization, single-pass. 2554 */ 2555void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 2556 unsigned long start_pfn, enum memmap_context context) 2557{ 2558 struct page *page; 2559 unsigned long end_pfn = start_pfn + size; 2560 unsigned long pfn; 2561 struct zone *z; 2562 2563 z = &NODE_DATA(nid)->node_zones[zone]; 2564 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 2565 /* 2566 * There can be holes in boot-time mem_map[]s 2567 * handed to this function. They do not 2568 * exist on hotplugged memory. 2569 */ 2570 if (context == MEMMAP_EARLY) { 2571 if (!early_pfn_valid(pfn)) 2572 continue; 2573 if (!early_pfn_in_nid(pfn, nid)) 2574 continue; 2575 } 2576 page = pfn_to_page(pfn); 2577 set_page_links(page, zone, nid, pfn); 2578 mminit_verify_page_links(page, zone, nid, pfn); 2579 init_page_count(page); 2580 reset_page_mapcount(page); 2581 SetPageReserved(page); 2582 /* 2583 * Mark the block movable so that blocks are reserved for 2584 * movable at startup. This will force kernel allocations 2585 * to reserve their blocks rather than leaking throughout 2586 * the address space during boot when many long-lived 2587 * kernel allocations are made. Later some blocks near 2588 * the start are marked MIGRATE_RESERVE by 2589 * setup_zone_migrate_reserve() 2590 * 2591 * bitmap is created for zone's valid pfn range. but memmap 2592 * can be created for invalid pages (for alignment) 2593 * check here not to call set_pageblock_migratetype() against 2594 * pfn out of zone. 2595 */ 2596 if ((z->zone_start_pfn <= pfn) 2597 && (pfn < z->zone_start_pfn + z->spanned_pages) 2598 && !(pfn & (pageblock_nr_pages - 1))) 2599 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 2600 2601 INIT_LIST_HEAD(&page->lru); 2602#ifdef WANT_PAGE_VIRTUAL 2603 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 2604 if (!is_highmem_idx(zone)) 2605 set_page_address(page, __va(pfn << PAGE_SHIFT)); 2606#endif 2607 } 2608} 2609 2610static void __meminit zone_init_free_lists(struct zone *zone) 2611{ 2612 int order, t; 2613 for_each_migratetype_order(order, t) { 2614 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); 2615 zone->free_area[order].nr_free = 0; 2616 } 2617} 2618 2619#ifndef __HAVE_ARCH_MEMMAP_INIT 2620#define memmap_init(size, nid, zone, start_pfn) \ 2621 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) 2622#endif 2623 2624static int zone_batchsize(struct zone *zone) 2625{ 2626 int batch; 2627 2628 /* 2629 * The per-cpu-pages pools are set to around 1000th of the 2630 * size of the zone. But no more than 1/2 of a meg. 2631 * 2632 * OK, so we don't know how big the cache is. So guess. 2633 */ 2634 batch = zone->present_pages / 1024; 2635 if (batch * PAGE_SIZE > 512 * 1024) 2636 batch = (512 * 1024) / PAGE_SIZE; 2637 batch /= 4; /* We effectively *= 4 below */ 2638 if (batch < 1) 2639 batch = 1; 2640 2641 /* 2642 * Clamp the batch to a 2^n - 1 value. Having a power 2643 * of 2 value was found to be more likely to have 2644 * suboptimal cache aliasing properties in some cases. 2645 * 2646 * For example if 2 tasks are alternately allocating 2647 * batches of pages, one task can end up with a lot 2648 * of pages of one half of the possible page colors 2649 * and the other with pages of the other colors. 2650 */ 2651 batch = (1 << (fls(batch + batch/2)-1)) - 1; 2652 2653 return batch; 2654} 2655 2656static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 2657{ 2658 struct per_cpu_pages *pcp; 2659 2660 memset(p, 0, sizeof(*p)); 2661 2662 pcp = &p->pcp; 2663 pcp->count = 0; 2664 pcp->high = 6 * batch; 2665 pcp->batch = max(1UL, 1 * batch); 2666 INIT_LIST_HEAD(&pcp->list); 2667} 2668 2669/* 2670 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist 2671 * to the value high for the pageset p. 2672 */ 2673 2674static void setup_pagelist_highmark(struct per_cpu_pageset *p, 2675 unsigned long high) 2676{ 2677 struct per_cpu_pages *pcp; 2678 2679 pcp = &p->pcp; 2680 pcp->high = high; 2681 pcp->batch = max(1UL, high/4); 2682 if ((high/4) > (PAGE_SHIFT * 8)) 2683 pcp->batch = PAGE_SHIFT * 8; 2684} 2685 2686 2687#ifdef CONFIG_NUMA 2688/* 2689 * Boot pageset table. One per cpu which is going to be used for all 2690 * zones and all nodes. The parameters will be set in such a way 2691 * that an item put on a list will immediately be handed over to 2692 * the buddy list. This is safe since pageset manipulation is done 2693 * with interrupts disabled. 2694 * 2695 * Some NUMA counter updates may also be caught by the boot pagesets. 2696 * 2697 * The boot_pagesets must be kept even after bootup is complete for 2698 * unused processors and/or zones. They do play a role for bootstrapping 2699 * hotplugged processors. 2700 * 2701 * zoneinfo_show() and maybe other functions do 2702 * not check if the processor is online before following the pageset pointer. 2703 * Other parts of the kernel may not check if the zone is available. 2704 */ 2705static struct per_cpu_pageset boot_pageset[NR_CPUS]; 2706 2707/* 2708 * Dynamically allocate memory for the 2709 * per cpu pageset array in struct zone. 2710 */ 2711static int __cpuinit process_zones(int cpu) 2712{ 2713 struct zone *zone, *dzone; 2714 int node = cpu_to_node(cpu); 2715 2716 node_set_state(node, N_CPU); /* this node has a cpu */ 2717 2718 for_each_zone(zone) { 2719 2720 if (!populated_zone(zone)) 2721 continue; 2722 2723 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset), 2724 GFP_KERNEL, node); 2725 if (!zone_pcp(zone, cpu)) 2726 goto bad; 2727 2728 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone)); 2729 2730 if (percpu_pagelist_fraction) 2731 setup_pagelist_highmark(zone_pcp(zone, cpu), 2732 (zone->present_pages / percpu_pagelist_fraction)); 2733 } 2734 2735 return 0; 2736bad: 2737 for_each_zone(dzone) { 2738 if (!populated_zone(dzone)) 2739 continue; 2740 if (dzone == zone) 2741 break; 2742 kfree(zone_pcp(dzone, cpu)); 2743 zone_pcp(dzone, cpu) = NULL; 2744 } 2745 return -ENOMEM; 2746} 2747 2748static inline void free_zone_pagesets(int cpu) 2749{ 2750 struct zone *zone; 2751 2752 for_each_zone(zone) { 2753 struct per_cpu_pageset *pset = zone_pcp(zone, cpu); 2754 2755 /* Free per_cpu_pageset if it is slab allocated */ 2756 if (pset != &boot_pageset[cpu]) 2757 kfree(pset); 2758 zone_pcp(zone, cpu) = NULL; 2759 } 2760} 2761 2762static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb, 2763 unsigned long action, 2764 void *hcpu) 2765{ 2766 int cpu = (long)hcpu; 2767 int ret = NOTIFY_OK; 2768 2769 switch (action) { 2770 case CPU_UP_PREPARE: 2771 case CPU_UP_PREPARE_FROZEN: 2772 if (process_zones(cpu)) 2773 ret = NOTIFY_BAD; 2774 break; 2775 case CPU_UP_CANCELED: 2776 case CPU_UP_CANCELED_FROZEN: 2777 case CPU_DEAD: 2778 case CPU_DEAD_FROZEN: 2779 free_zone_pagesets(cpu); 2780 break; 2781 default: 2782 break; 2783 } 2784 return ret; 2785} 2786 2787static struct notifier_block __cpuinitdata pageset_notifier = 2788 { &pageset_cpuup_callback, NULL, 0 }; 2789 2790void __init setup_per_cpu_pageset(void) 2791{ 2792 int err; 2793 2794 /* Initialize per_cpu_pageset for cpu 0. 2795 * A cpuup callback will do this for every cpu 2796 * as it comes online 2797 */ 2798 err = process_zones(smp_processor_id()); 2799 BUG_ON(err); 2800 register_cpu_notifier(&pageset_notifier); 2801} 2802 2803#endif 2804 2805static noinline __init_refok 2806int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 2807{ 2808 int i; 2809 struct pglist_data *pgdat = zone->zone_pgdat; 2810 size_t alloc_size; 2811 2812 /* 2813 * The per-page waitqueue mechanism uses hashed waitqueues 2814 * per zone. 2815 */ 2816 zone->wait_table_hash_nr_entries = 2817 wait_table_hash_nr_entries(zone_size_pages); 2818 zone->wait_table_bits = 2819 wait_table_bits(zone->wait_table_hash_nr_entries); 2820 alloc_size = zone->wait_table_hash_nr_entries 2821 * sizeof(wait_queue_head_t); 2822 2823 if (!slab_is_available()) { 2824 zone->wait_table = (wait_queue_head_t *) 2825 alloc_bootmem_node(pgdat, alloc_size); 2826 } else { 2827 /* 2828 * This case means that a zone whose size was 0 gets new memory 2829 * via memory hot-add. 2830 * But it may be the case that a new node was hot-added. In 2831 * this case vmalloc() will not be able to use this new node's 2832 * memory - this wait_table must be initialized to use this new 2833 * node itself as well. 2834 * To use this new node's memory, further consideration will be 2835 * necessary. 2836 */ 2837 zone->wait_table = vmalloc(alloc_size); 2838 } 2839 if (!zone->wait_table) 2840 return -ENOMEM; 2841 2842 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i) 2843 init_waitqueue_head(zone->wait_table + i); 2844 2845 return 0; 2846} 2847 2848static __meminit void zone_pcp_init(struct zone *zone) 2849{ 2850 int cpu; 2851 unsigned long batch = zone_batchsize(zone); 2852 2853 for (cpu = 0; cpu < NR_CPUS; cpu++) { 2854#ifdef CONFIG_NUMA 2855 /* Early boot. Slab allocator not functional yet */ 2856 zone_pcp(zone, cpu) = &boot_pageset[cpu]; 2857 setup_pageset(&boot_pageset[cpu],0); 2858#else 2859 setup_pageset(zone_pcp(zone,cpu), batch); 2860#endif 2861 } 2862 if (zone->present_pages) 2863 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", 2864 zone->name, zone->present_pages, batch); 2865} 2866 2867__meminit int init_currently_empty_zone(struct zone *zone, 2868 unsigned long zone_start_pfn, 2869 unsigned long size, 2870 enum memmap_context context) 2871{ 2872 struct pglist_data *pgdat = zone->zone_pgdat; 2873 int ret; 2874 ret = zone_wait_table_init(zone, size); 2875 if (ret) 2876 return ret; 2877 pgdat->nr_zones = zone_idx(zone) + 1; 2878 2879 zone->zone_start_pfn = zone_start_pfn; 2880 2881 mminit_dprintk(MMINIT_TRACE, "memmap_init", 2882 "Initialising map node %d zone %lu pfns %lu -> %lu\n", 2883 pgdat->node_id, 2884 (unsigned long)zone_idx(zone), 2885 zone_start_pfn, (zone_start_pfn + size)); 2886 2887 zone_init_free_lists(zone); 2888 2889 return 0; 2890} 2891 2892#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 2893/* 2894 * Basic iterator support. Return the first range of PFNs for a node 2895 * Note: nid == MAX_NUMNODES returns first region regardless of node 2896 */ 2897static int __meminit first_active_region_index_in_nid(int nid) 2898{ 2899 int i; 2900 2901 for (i = 0; i < nr_nodemap_entries; i++) 2902 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid) 2903 return i; 2904 2905 return -1; 2906} 2907 2908/* 2909 * Basic iterator support. Return the next active range of PFNs for a node 2910 * Note: nid == MAX_NUMNODES returns next region regardless of node 2911 */ 2912static int __meminit next_active_region_index_in_nid(int index, int nid) 2913{ 2914 for (index = index + 1; index < nr_nodemap_entries; index++) 2915 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid) 2916 return index; 2917 2918 return -1; 2919} 2920 2921#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID 2922/* 2923 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. 2924 * Architectures may implement their own version but if add_active_range() 2925 * was used and there are no special requirements, this is a convenient 2926 * alternative 2927 */ 2928int __meminit early_pfn_to_nid(unsigned long pfn) 2929{ 2930 int i; 2931 2932 for (i = 0; i < nr_nodemap_entries; i++) { 2933 unsigned long start_pfn = early_node_map[i].start_pfn; 2934 unsigned long end_pfn = early_node_map[i].end_pfn; 2935 2936 if (start_pfn <= pfn && pfn < end_pfn) 2937 return early_node_map[i].nid; 2938 } 2939 2940 return 0; 2941} 2942#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ 2943 2944/* Basic iterator support to walk early_node_map[] */ 2945#define for_each_active_range_index_in_nid(i, nid) \ 2946 for (i = first_active_region_index_in_nid(nid); i != -1; \ 2947 i = next_active_region_index_in_nid(i, nid)) 2948 2949/** 2950 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range 2951 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. 2952 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node 2953 * 2954 * If an architecture guarantees that all ranges registered with 2955 * add_active_ranges() contain no holes and may be freed, this 2956 * this function may be used instead of calling free_bootmem() manually. 2957 */ 2958void __init free_bootmem_with_active_regions(int nid, 2959 unsigned long max_low_pfn) 2960{ 2961 int i; 2962 2963 for_each_active_range_index_in_nid(i, nid) { 2964 unsigned long size_pages = 0; 2965 unsigned long end_pfn = early_node_map[i].end_pfn; 2966 2967 if (early_node_map[i].start_pfn >= max_low_pfn) 2968 continue; 2969 2970 if (end_pfn > max_low_pfn) 2971 end_pfn = max_low_pfn; 2972 2973 size_pages = end_pfn - early_node_map[i].start_pfn; 2974 free_bootmem_node(NODE_DATA(early_node_map[i].nid), 2975 PFN_PHYS(early_node_map[i].start_pfn), 2976 size_pages << PAGE_SHIFT); 2977 } 2978} 2979 2980void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data) 2981{ 2982 int i; 2983 int ret; 2984 2985 for_each_active_range_index_in_nid(i, nid) { 2986 ret = work_fn(early_node_map[i].start_pfn, 2987 early_node_map[i].end_pfn, data); 2988 if (ret) 2989 break; 2990 } 2991} 2992/** 2993 * sparse_memory_present_with_active_regions - Call memory_present for each active range 2994 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. 2995 * 2996 * If an architecture guarantees that all ranges registered with 2997 * add_active_ranges() contain no holes and may be freed, this 2998 * function may be used instead of calling memory_present() manually. 2999 */ 3000void __init sparse_memory_present_with_active_regions(int nid) 3001{ 3002 int i; 3003 3004 for_each_active_range_index_in_nid(i, nid) 3005 memory_present(early_node_map[i].nid, 3006 early_node_map[i].start_pfn, 3007 early_node_map[i].end_pfn); 3008} 3009 3010/** 3011 * push_node_boundaries - Push node boundaries to at least the requested boundary 3012 * @nid: The nid of the node to push the boundary for 3013 * @start_pfn: The start pfn of the node 3014 * @end_pfn: The end pfn of the node 3015 * 3016 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd 3017 * time. Specifically, on x86_64, SRAT will report ranges that can potentially 3018 * be hotplugged even though no physical memory exists. This function allows 3019 * an arch to push out the node boundaries so mem_map is allocated that can 3020 * be used later. 3021 */ 3022#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE 3023void __init push_node_boundaries(unsigned int nid, 3024 unsigned long start_pfn, unsigned long end_pfn) 3025{ 3026 mminit_dprintk(MMINIT_TRACE, "zoneboundary", 3027 "Entering push_node_boundaries(%u, %lu, %lu)\n", 3028 nid, start_pfn, end_pfn); 3029 3030 /* Initialise the boundary for this node if necessary */ 3031 if (node_boundary_end_pfn[nid] == 0) 3032 node_boundary_start_pfn[nid] = -1UL; 3033 3034 /* Update the boundaries */ 3035 if (node_boundary_start_pfn[nid] > start_pfn) 3036 node_boundary_start_pfn[nid] = start_pfn; 3037 if (node_boundary_end_pfn[nid] < end_pfn) 3038 node_boundary_end_pfn[nid] = end_pfn; 3039} 3040 3041/* If necessary, push the node boundary out for reserve hotadd */ 3042static void __meminit account_node_boundary(unsigned int nid, 3043 unsigned long *start_pfn, unsigned long *end_pfn) 3044{ 3045 mminit_dprintk(MMINIT_TRACE, "zoneboundary", 3046 "Entering account_node_boundary(%u, %lu, %lu)\n", 3047 nid, *start_pfn, *end_pfn); 3048 3049 /* Return if boundary information has not been provided */ 3050 if (node_boundary_end_pfn[nid] == 0) 3051 return; 3052 3053 /* Check the boundaries and update if necessary */ 3054 if (node_boundary_start_pfn[nid] < *start_pfn) 3055 *start_pfn = node_boundary_start_pfn[nid]; 3056 if (node_boundary_end_pfn[nid] > *end_pfn) 3057 *end_pfn = node_boundary_end_pfn[nid]; 3058} 3059#else 3060void __init push_node_boundaries(unsigned int nid, 3061 unsigned long start_pfn, unsigned long end_pfn) {} 3062 3063static void __meminit account_node_boundary(unsigned int nid, 3064 unsigned long *start_pfn, unsigned long *end_pfn) {} 3065#endif 3066 3067 3068/** 3069 * get_pfn_range_for_nid - Return the start and end page frames for a node 3070 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. 3071 * @start_pfn: Passed by reference. On return, it will have the node start_pfn. 3072 * @end_pfn: Passed by reference. On return, it will have the node end_pfn. 3073 * 3074 * It returns the start and end page frame of a node based on information 3075 * provided by an arch calling add_active_range(). If called for a node 3076 * with no available memory, a warning is printed and the start and end 3077 * PFNs will be 0. 3078 */ 3079void __meminit get_pfn_range_for_nid(unsigned int nid, 3080 unsigned long *start_pfn, unsigned long *end_pfn) 3081{ 3082 int i; 3083 *start_pfn = -1UL; 3084 *end_pfn = 0; 3085 3086 for_each_active_range_index_in_nid(i, nid) { 3087 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn); 3088 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn); 3089 } 3090 3091 if (*start_pfn == -1UL) 3092 *start_pfn = 0; 3093 3094 /* Push the node boundaries out if requested */ 3095 account_node_boundary(nid, start_pfn, end_pfn); 3096} 3097 3098/* 3099 * This finds a zone that can be used for ZONE_MOVABLE pages. The 3100 * assumption is made that zones within a node are ordered in monotonic 3101 * increasing memory addresses so that the "highest" populated zone is used 3102 */ 3103static void __init find_usable_zone_for_movable(void) 3104{ 3105 int zone_index; 3106 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { 3107 if (zone_index == ZONE_MOVABLE) 3108 continue; 3109 3110 if (arch_zone_highest_possible_pfn[zone_index] > 3111 arch_zone_lowest_possible_pfn[zone_index]) 3112 break; 3113 } 3114 3115 VM_BUG_ON(zone_index == -1); 3116 movable_zone = zone_index; 3117} 3118 3119/* 3120 * The zone ranges provided by the architecture do not include ZONE_MOVABLE 3121 * because it is sized independant of architecture. Unlike the other zones, 3122 * the starting point for ZONE_MOVABLE is not fixed. It may be different 3123 * in each node depending on the size of each node and how evenly kernelcore 3124 * is distributed. This helper function adjusts the zone ranges 3125 * provided by the architecture for a given node by using the end of the 3126 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that 3127 * zones within a node are in order of monotonic increases memory addresses 3128 */ 3129static void __meminit adjust_zone_range_for_zone_movable(int nid, 3130 unsigned long zone_type, 3131 unsigned long node_start_pfn, 3132 unsigned long node_end_pfn, 3133 unsigned long *zone_start_pfn, 3134 unsigned long *zone_end_pfn) 3135{ 3136 /* Only adjust if ZONE_MOVABLE is on this node */ 3137 if (zone_movable_pfn[nid]) { 3138 /* Size ZONE_MOVABLE */ 3139 if (zone_type == ZONE_MOVABLE) { 3140 *zone_start_pfn = zone_movable_pfn[nid]; 3141 *zone_end_pfn = min(node_end_pfn, 3142 arch_zone_highest_possible_pfn[movable_zone]); 3143 3144 /* Adjust for ZONE_MOVABLE starting within this range */ 3145 } else if (*zone_start_pfn < zone_movable_pfn[nid] && 3146 *zone_end_pfn > zone_movable_pfn[nid]) { 3147 *zone_end_pfn = zone_movable_pfn[nid]; 3148 3149 /* Check if this whole range is within ZONE_MOVABLE */ 3150 } else if (*zone_start_pfn >= zone_movable_pfn[nid]) 3151 *zone_start_pfn = *zone_end_pfn; 3152 } 3153} 3154 3155/* 3156 * Return the number of pages a zone spans in a node, including holes 3157 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() 3158 */ 3159static unsigned long __meminit zone_spanned_pages_in_node(int nid, 3160 unsigned long zone_type, 3161 unsigned long *ignored) 3162{ 3163 unsigned long node_start_pfn, node_end_pfn; 3164 unsigned long zone_start_pfn, zone_end_pfn; 3165 3166 /* Get the start and end of the node and zone */ 3167 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3168 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; 3169 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; 3170 adjust_zone_range_for_zone_movable(nid, zone_type, 3171 node_start_pfn, node_end_pfn, 3172 &zone_start_pfn, &zone_end_pfn); 3173 3174 /* Check that this node has pages within the zone's required range */ 3175 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) 3176 return 0; 3177 3178 /* Move the zone boundaries inside the node if necessary */ 3179 zone_end_pfn = min(zone_end_pfn, node_end_pfn); 3180 zone_start_pfn = max(zone_start_pfn, node_start_pfn); 3181 3182 /* Return the spanned pages */ 3183 return zone_end_pfn - zone_start_pfn; 3184} 3185 3186/* 3187 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, 3188 * then all holes in the requested range will be accounted for. 3189 */ 3190static unsigned long __meminit __absent_pages_in_range(int nid, 3191 unsigned long range_start_pfn, 3192 unsigned long range_end_pfn) 3193{ 3194 int i = 0; 3195 unsigned long prev_end_pfn = 0, hole_pages = 0; 3196 unsigned long start_pfn; 3197 3198 /* Find the end_pfn of the first active range of pfns in the node */ 3199 i = first_active_region_index_in_nid(nid); 3200 if (i == -1) 3201 return 0; 3202 3203 prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 3204 3205 /* Account for ranges before physical memory on this node */ 3206 if (early_node_map[i].start_pfn > range_start_pfn) 3207 hole_pages = prev_end_pfn - range_start_pfn; 3208 3209 /* Find all holes for the zone within the node */ 3210 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) { 3211 3212 /* No need to continue if prev_end_pfn is outside the zone */ 3213 if (prev_end_pfn >= range_end_pfn) 3214 break; 3215 3216 /* Make sure the end of the zone is not within the hole */ 3217 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 3218 prev_end_pfn = max(prev_end_pfn, range_start_pfn); 3219 3220 /* Update the hole size cound and move on */ 3221 if (start_pfn > range_start_pfn) { 3222 BUG_ON(prev_end_pfn > start_pfn); 3223 hole_pages += start_pfn - prev_end_pfn; 3224 } 3225 prev_end_pfn = early_node_map[i].end_pfn; 3226 } 3227 3228 /* Account for ranges past physical memory on this node */ 3229 if (range_end_pfn > prev_end_pfn) 3230 hole_pages += range_end_pfn - 3231 max(range_start_pfn, prev_end_pfn); 3232 3233 return hole_pages; 3234} 3235 3236/** 3237 * absent_pages_in_range - Return number of page frames in holes within a range 3238 * @start_pfn: The start PFN to start searching for holes 3239 * @end_pfn: The end PFN to stop searching for holes 3240 * 3241 * It returns the number of pages frames in memory holes within a range. 3242 */ 3243unsigned long __init absent_pages_in_range(unsigned long start_pfn, 3244 unsigned long end_pfn) 3245{ 3246 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); 3247} 3248 3249/* Return the number of page frames in holes in a zone on a node */ 3250static unsigned long __meminit zone_absent_pages_in_node(int nid, 3251 unsigned long zone_type, 3252 unsigned long *ignored) 3253{ 3254 unsigned long node_start_pfn, node_end_pfn; 3255 unsigned long zone_start_pfn, zone_end_pfn; 3256 3257 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3258 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type], 3259 node_start_pfn); 3260 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type], 3261 node_end_pfn); 3262 3263 adjust_zone_range_for_zone_movable(nid, zone_type, 3264 node_start_pfn, node_end_pfn, 3265 &zone_start_pfn, &zone_end_pfn); 3266 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); 3267} 3268 3269#else 3270static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, 3271 unsigned long zone_type, 3272 unsigned long *zones_size) 3273{ 3274 return zones_size[zone_type]; 3275} 3276 3277static inline unsigned long __meminit zone_absent_pages_in_node(int nid, 3278 unsigned long zone_type, 3279 unsigned long *zholes_size) 3280{ 3281 if (!zholes_size) 3282 return 0; 3283 3284 return zholes_size[zone_type]; 3285} 3286 3287#endif 3288 3289static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, 3290 unsigned long *zones_size, unsigned long *zholes_size) 3291{ 3292 unsigned long realtotalpages, totalpages = 0; 3293 enum zone_type i; 3294 3295 for (i = 0; i < MAX_NR_ZONES; i++) 3296 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i, 3297 zones_size); 3298 pgdat->node_spanned_pages = totalpages; 3299 3300 realtotalpages = totalpages; 3301 for (i = 0; i < MAX_NR_ZONES; i++) 3302 realtotalpages -= 3303 zone_absent_pages_in_node(pgdat->node_id, i, 3304 zholes_size); 3305 pgdat->node_present_pages = realtotalpages; 3306 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, 3307 realtotalpages); 3308} 3309 3310#ifndef CONFIG_SPARSEMEM 3311/* 3312 * Calculate the size of the zone->blockflags rounded to an unsigned long 3313 * Start by making sure zonesize is a multiple of pageblock_order by rounding 3314 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally 3315 * round what is now in bits to nearest long in bits, then return it in 3316 * bytes. 3317 */ 3318static unsigned long __init usemap_size(unsigned long zonesize) 3319{ 3320 unsigned long usemapsize; 3321 3322 usemapsize = roundup(zonesize, pageblock_nr_pages); 3323 usemapsize = usemapsize >> pageblock_order; 3324 usemapsize *= NR_PAGEBLOCK_BITS; 3325 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); 3326 3327 return usemapsize / 8; 3328} 3329 3330static void __init setup_usemap(struct pglist_data *pgdat, 3331 struct zone *zone, unsigned long zonesize) 3332{ 3333 unsigned long usemapsize = usemap_size(zonesize); 3334 zone->pageblock_flags = NULL; 3335 if (usemapsize) { 3336 zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize); 3337 memset(zone->pageblock_flags, 0, usemapsize); 3338 } 3339} 3340#else 3341static void inline setup_usemap(struct pglist_data *pgdat, 3342 struct zone *zone, unsigned long zonesize) {} 3343#endif /* CONFIG_SPARSEMEM */ 3344 3345#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 3346 3347/* Return a sensible default order for the pageblock size. */ 3348static inline int pageblock_default_order(void) 3349{ 3350 if (HPAGE_SHIFT > PAGE_SHIFT) 3351 return HUGETLB_PAGE_ORDER; 3352 3353 return MAX_ORDER-1; 3354} 3355 3356/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ 3357static inline void __init set_pageblock_order(unsigned int order) 3358{ 3359 /* Check that pageblock_nr_pages has not already been setup */ 3360 if (pageblock_order) 3361 return; 3362 3363 /* 3364 * Assume the largest contiguous order of interest is a huge page. 3365 * This value may be variable depending on boot parameters on IA64 3366 */ 3367 pageblock_order = order; 3368} 3369#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 3370 3371/* 3372 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() 3373 * and pageblock_default_order() are unused as pageblock_order is set 3374 * at compile-time. See include/linux/pageblock-flags.h for the values of 3375 * pageblock_order based on the kernel config 3376 */ 3377static inline int pageblock_default_order(unsigned int order) 3378{ 3379 return MAX_ORDER-1; 3380} 3381#define set_pageblock_order(x) do {} while (0) 3382 3383#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 3384 3385/* 3386 * Set up the zone data structures: 3387 * - mark all pages reserved 3388 * - mark all memory queues empty 3389 * - clear the memory bitmaps 3390 */ 3391static void __paginginit free_area_init_core(struct pglist_data *pgdat, 3392 unsigned long *zones_size, unsigned long *zholes_size) 3393{ 3394 enum zone_type j; 3395 int nid = pgdat->node_id; 3396 unsigned long zone_start_pfn = pgdat->node_start_pfn; 3397 int ret; 3398 3399 pgdat_resize_init(pgdat); 3400 pgdat->nr_zones = 0; 3401 init_waitqueue_head(&pgdat->kswapd_wait); 3402 pgdat->kswapd_max_order = 0; 3403 3404 for (j = 0; j < MAX_NR_ZONES; j++) { 3405 struct zone *zone = pgdat->node_zones + j; 3406 unsigned long size, realsize, memmap_pages; 3407 3408 size = zone_spanned_pages_in_node(nid, j, zones_size); 3409 realsize = size - zone_absent_pages_in_node(nid, j, 3410 zholes_size); 3411 3412 /* 3413 * Adjust realsize so that it accounts for how much memory 3414 * is used by this zone for memmap. This affects the watermark 3415 * and per-cpu initialisations 3416 */ 3417 memmap_pages = 3418 PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT; 3419 if (realsize >= memmap_pages) { 3420 realsize -= memmap_pages; 3421 mminit_dprintk(MMINIT_TRACE, "memmap_init", 3422 "%s zone: %lu pages used for memmap\n", 3423 zone_names[j], memmap_pages); 3424 } else 3425 printk(KERN_WARNING 3426 " %s zone: %lu pages exceeds realsize %lu\n", 3427 zone_names[j], memmap_pages, realsize); 3428 3429 /* Account for reserved pages */ 3430 if (j == 0 && realsize > dma_reserve) { 3431 realsize -= dma_reserve; 3432 mminit_dprintk(MMINIT_TRACE, "memmap_init", 3433 "%s zone: %lu pages reserved\n", 3434 zone_names[0], dma_reserve); 3435 } 3436 3437 if (!is_highmem_idx(j)) 3438 nr_kernel_pages += realsize; 3439 nr_all_pages += realsize; 3440 3441 zone->spanned_pages = size; 3442 zone->present_pages = realsize; 3443#ifdef CONFIG_NUMA 3444 zone->node = nid; 3445 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio) 3446 / 100; 3447 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100; 3448#endif 3449 zone->name = zone_names[j]; 3450 spin_lock_init(&zone->lock); 3451 spin_lock_init(&zone->lru_lock); 3452 zone_seqlock_init(zone); 3453 zone->zone_pgdat = pgdat; 3454 3455 zone->prev_priority = DEF_PRIORITY; 3456 3457 zone_pcp_init(zone); 3458 INIT_LIST_HEAD(&zone->active_list); 3459 INIT_LIST_HEAD(&zone->inactive_list); 3460 zone->nr_scan_active = 0; 3461 zone->nr_scan_inactive = 0; 3462 zap_zone_vm_stats(zone); 3463 zone->flags = 0; 3464 if (!size) 3465 continue; 3466 3467 set_pageblock_order(pageblock_default_order()); 3468 setup_usemap(pgdat, zone, size); 3469 ret = init_currently_empty_zone(zone, zone_start_pfn, 3470 size, MEMMAP_EARLY); 3471 BUG_ON(ret); 3472 memmap_init(size, nid, j, zone_start_pfn); 3473 zone_start_pfn += size; 3474 } 3475} 3476 3477static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat) 3478{ 3479 /* Skip empty nodes */ 3480 if (!pgdat->node_spanned_pages) 3481 return; 3482 3483#ifdef CONFIG_FLAT_NODE_MEM_MAP 3484 /* ia64 gets its own node_mem_map, before this, without bootmem */ 3485 if (!pgdat->node_mem_map) { 3486 unsigned long size, start, end; 3487 struct page *map; 3488 3489 /* 3490 * The zone's endpoints aren't required to be MAX_ORDER 3491 * aligned but the node_mem_map endpoints must be in order 3492 * for the buddy allocator to function correctly. 3493 */ 3494 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); 3495 end = pgdat->node_start_pfn + pgdat->node_spanned_pages; 3496 end = ALIGN(end, MAX_ORDER_NR_PAGES); 3497 size = (end - start) * sizeof(struct page); 3498 map = alloc_remap(pgdat->node_id, size); 3499 if (!map) 3500 map = alloc_bootmem_node(pgdat, size); 3501 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); 3502 } 3503#ifndef CONFIG_NEED_MULTIPLE_NODES 3504 /* 3505 * With no DISCONTIG, the global mem_map is just set as node 0's 3506 */ 3507 if (pgdat == NODE_DATA(0)) { 3508 mem_map = NODE_DATA(0)->node_mem_map; 3509#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3510 if (page_to_pfn(mem_map) != pgdat->node_start_pfn) 3511 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET); 3512#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 3513 } 3514#endif 3515#endif /* CONFIG_FLAT_NODE_MEM_MAP */ 3516} 3517 3518void __paginginit free_area_init_node(int nid, unsigned long *zones_size, 3519 unsigned long node_start_pfn, unsigned long *zholes_size) 3520{ 3521 pg_data_t *pgdat = NODE_DATA(nid); 3522 3523 pgdat->node_id = nid; 3524 pgdat->node_start_pfn = node_start_pfn; 3525 calculate_node_totalpages(pgdat, zones_size, zholes_size); 3526 3527 alloc_node_mem_map(pgdat); 3528#ifdef CONFIG_FLAT_NODE_MEM_MAP 3529 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n", 3530 nid, (unsigned long)pgdat, 3531 (unsigned long)pgdat->node_mem_map); 3532#endif 3533 3534 free_area_init_core(pgdat, zones_size, zholes_size); 3535} 3536 3537#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3538 3539#if MAX_NUMNODES > 1 3540/* 3541 * Figure out the number of possible node ids. 3542 */ 3543static void __init setup_nr_node_ids(void) 3544{ 3545 unsigned int node; 3546 unsigned int highest = 0; 3547 3548 for_each_node_mask(node, node_possible_map) 3549 highest = node; 3550 nr_node_ids = highest + 1; 3551} 3552#else 3553static inline void setup_nr_node_ids(void) 3554{ 3555} 3556#endif 3557 3558/** 3559 * add_active_range - Register a range of PFNs backed by physical memory 3560 * @nid: The node ID the range resides on 3561 * @start_pfn: The start PFN of the available physical memory 3562 * @end_pfn: The end PFN of the available physical memory 3563 * 3564 * These ranges are stored in an early_node_map[] and later used by 3565 * free_area_init_nodes() to calculate zone sizes and holes. If the 3566 * range spans a memory hole, it is up to the architecture to ensure 3567 * the memory is not freed by the bootmem allocator. If possible 3568 * the range being registered will be merged with existing ranges. 3569 */ 3570void __init add_active_range(unsigned int nid, unsigned long start_pfn, 3571 unsigned long end_pfn) 3572{ 3573 int i; 3574 3575 mminit_dprintk(MMINIT_TRACE, "memory_register", 3576 "Entering add_active_range(%d, %#lx, %#lx) " 3577 "%d entries of %d used\n", 3578 nid, start_pfn, end_pfn, 3579 nr_nodemap_entries, MAX_ACTIVE_REGIONS); 3580 3581 mminit_validate_memmodel_limits(&start_pfn, &end_pfn); 3582 3583 /* Merge with existing active regions if possible */ 3584 for (i = 0; i < nr_nodemap_entries; i++) { 3585 if (early_node_map[i].nid != nid) 3586 continue; 3587 3588 /* Skip if an existing region covers this new one */ 3589 if (start_pfn >= early_node_map[i].start_pfn && 3590 end_pfn <= early_node_map[i].end_pfn) 3591 return; 3592 3593 /* Merge forward if suitable */ 3594 if (start_pfn <= early_node_map[i].end_pfn && 3595 end_pfn > early_node_map[i].end_pfn) { 3596 early_node_map[i].end_pfn = end_pfn; 3597 return; 3598 } 3599 3600 /* Merge backward if suitable */ 3601 if (start_pfn < early_node_map[i].end_pfn && 3602 end_pfn >= early_node_map[i].start_pfn) { 3603 early_node_map[i].start_pfn = start_pfn; 3604 return; 3605 } 3606 } 3607 3608 /* Check that early_node_map is large enough */ 3609 if (i >= MAX_ACTIVE_REGIONS) { 3610 printk(KERN_CRIT "More than %d memory regions, truncating\n", 3611 MAX_ACTIVE_REGIONS); 3612 return; 3613 } 3614 3615 early_node_map[i].nid = nid; 3616 early_node_map[i].start_pfn = start_pfn; 3617 early_node_map[i].end_pfn = end_pfn; 3618 nr_nodemap_entries = i + 1; 3619} 3620 3621/** 3622 * remove_active_range - Shrink an existing registered range of PFNs 3623 * @nid: The node id the range is on that should be shrunk 3624 * @start_pfn: The new PFN of the range 3625 * @end_pfn: The new PFN of the range 3626 * 3627 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node. 3628 * The map is kept near the end physical page range that has already been 3629 * registered. This function allows an arch to shrink an existing registered 3630 * range. 3631 */ 3632void __init remove_active_range(unsigned int nid, unsigned long start_pfn, 3633 unsigned long end_pfn) 3634{ 3635 int i, j; 3636 int removed = 0; 3637 3638 printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n", 3639 nid, start_pfn, end_pfn); 3640 3641 /* Find the old active region end and shrink */ 3642 for_each_active_range_index_in_nid(i, nid) { 3643 if (early_node_map[i].start_pfn >= start_pfn && 3644 early_node_map[i].end_pfn <= end_pfn) { 3645 /* clear it */ 3646 early_node_map[i].start_pfn = 0; 3647 early_node_map[i].end_pfn = 0; 3648 removed = 1; 3649 continue; 3650 } 3651 if (early_node_map[i].start_pfn < start_pfn && 3652 early_node_map[i].end_pfn > start_pfn) { 3653 unsigned long temp_end_pfn = early_node_map[i].end_pfn; 3654 early_node_map[i].end_pfn = start_pfn; 3655 if (temp_end_pfn > end_pfn) 3656 add_active_range(nid, end_pfn, temp_end_pfn); 3657 continue; 3658 } 3659 if (early_node_map[i].start_pfn >= start_pfn && 3660 early_node_map[i].end_pfn > end_pfn && 3661 early_node_map[i].start_pfn < end_pfn) { 3662 early_node_map[i].start_pfn = end_pfn; 3663 continue; 3664 } 3665 } 3666 3667 if (!removed) 3668 return; 3669 3670 /* remove the blank ones */ 3671 for (i = nr_nodemap_entries - 1; i > 0; i--) { 3672 if (early_node_map[i].nid != nid) 3673 continue; 3674 if (early_node_map[i].end_pfn) 3675 continue; 3676 /* we found it, get rid of it */ 3677 for (j = i; j < nr_nodemap_entries - 1; j++) 3678 memcpy(&early_node_map[j], &early_node_map[j+1], 3679 sizeof(early_node_map[j])); 3680 j = nr_nodemap_entries - 1; 3681 memset(&early_node_map[j], 0, sizeof(early_node_map[j])); 3682 nr_nodemap_entries--; 3683 } 3684} 3685 3686/** 3687 * remove_all_active_ranges - Remove all currently registered regions 3688 * 3689 * During discovery, it may be found that a table like SRAT is invalid 3690 * and an alternative discovery method must be used. This function removes 3691 * all currently registered regions. 3692 */ 3693void __init remove_all_active_ranges(void) 3694{ 3695 memset(early_node_map, 0, sizeof(early_node_map)); 3696 nr_nodemap_entries = 0; 3697#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE 3698 memset(node_boundary_start_pfn, 0, sizeof(node_boundary_start_pfn)); 3699 memset(node_boundary_end_pfn, 0, sizeof(node_boundary_end_pfn)); 3700#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */ 3701} 3702 3703/* Compare two active node_active_regions */ 3704static int __init cmp_node_active_region(const void *a, const void *b) 3705{ 3706 struct node_active_region *arange = (struct node_active_region *)a; 3707 struct node_active_region *brange = (struct node_active_region *)b; 3708 3709 /* Done this way to avoid overflows */ 3710 if (arange->start_pfn > brange->start_pfn) 3711 return 1; 3712 if (arange->start_pfn < brange->start_pfn) 3713 return -1; 3714 3715 return 0; 3716} 3717 3718/* sort the node_map by start_pfn */ 3719static void __init sort_node_map(void) 3720{ 3721 sort(early_node_map, (size_t)nr_nodemap_entries, 3722 sizeof(struct node_active_region), 3723 cmp_node_active_region, NULL); 3724} 3725 3726/* Find the lowest pfn for a node */ 3727static unsigned long __init find_min_pfn_for_node(int nid) 3728{ 3729 int i; 3730 unsigned long min_pfn = ULONG_MAX; 3731 3732 /* Assuming a sorted map, the first range found has the starting pfn */ 3733 for_each_active_range_index_in_nid(i, nid) 3734 min_pfn = min(min_pfn, early_node_map[i].start_pfn); 3735 3736 if (min_pfn == ULONG_MAX) { 3737 printk(KERN_WARNING 3738 "Could not find start_pfn for node %d\n", nid); 3739 return 0; 3740 } 3741 3742 return min_pfn; 3743} 3744 3745/** 3746 * find_min_pfn_with_active_regions - Find the minimum PFN registered 3747 * 3748 * It returns the minimum PFN based on information provided via 3749 * add_active_range(). 3750 */ 3751unsigned long __init find_min_pfn_with_active_regions(void) 3752{ 3753 return find_min_pfn_for_node(MAX_NUMNODES); 3754} 3755 3756/* 3757 * early_calculate_totalpages() 3758 * Sum pages in active regions for movable zone. 3759 * Populate N_HIGH_MEMORY for calculating usable_nodes. 3760 */ 3761static unsigned long __init early_calculate_totalpages(void) 3762{ 3763 int i; 3764 unsigned long totalpages = 0; 3765 3766 for (i = 0; i < nr_nodemap_entries; i++) { 3767 unsigned long pages = early_node_map[i].end_pfn - 3768 early_node_map[i].start_pfn; 3769 totalpages += pages; 3770 if (pages) 3771 node_set_state(early_node_map[i].nid, N_HIGH_MEMORY); 3772 } 3773 return totalpages; 3774} 3775 3776/* 3777 * Find the PFN the Movable zone begins in each node. Kernel memory 3778 * is spread evenly between nodes as long as the nodes have enough 3779 * memory. When they don't, some nodes will have more kernelcore than 3780 * others 3781 */ 3782static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn) 3783{ 3784 int i, nid; 3785 unsigned long usable_startpfn; 3786 unsigned long kernelcore_node, kernelcore_remaining; 3787 unsigned long totalpages = early_calculate_totalpages(); 3788 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]); 3789 3790 /* 3791 * If movablecore was specified, calculate what size of 3792 * kernelcore that corresponds so that memory usable for 3793 * any allocation type is evenly spread. If both kernelcore 3794 * and movablecore are specified, then the value of kernelcore 3795 * will be used for required_kernelcore if it's greater than 3796 * what movablecore would have allowed. 3797 */ 3798 if (required_movablecore) { 3799 unsigned long corepages; 3800 3801 /* 3802 * Round-up so that ZONE_MOVABLE is at least as large as what 3803 * was requested by the user 3804 */ 3805 required_movablecore = 3806 roundup(required_movablecore, MAX_ORDER_NR_PAGES); 3807 corepages = totalpages - required_movablecore; 3808 3809 required_kernelcore = max(required_kernelcore, corepages); 3810 } 3811 3812 /* If kernelcore was not specified, there is no ZONE_MOVABLE */ 3813 if (!required_kernelcore) 3814 return; 3815 3816 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ 3817 find_usable_zone_for_movable(); 3818 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; 3819 3820restart: 3821 /* Spread kernelcore memory as evenly as possible throughout nodes */ 3822 kernelcore_node = required_kernelcore / usable_nodes; 3823 for_each_node_state(nid, N_HIGH_MEMORY) { 3824 /* 3825 * Recalculate kernelcore_node if the division per node 3826 * now exceeds what is necessary to satisfy the requested 3827 * amount of memory for the kernel 3828 */ 3829 if (required_kernelcore < kernelcore_node) 3830 kernelcore_node = required_kernelcore / usable_nodes; 3831 3832 /* 3833 * As the map is walked, we track how much memory is usable 3834 * by the kernel using kernelcore_remaining. When it is 3835 * 0, the rest of the node is usable by ZONE_MOVABLE 3836 */ 3837 kernelcore_remaining = kernelcore_node; 3838 3839 /* Go through each range of PFNs within this node */ 3840 for_each_active_range_index_in_nid(i, nid) { 3841 unsigned long start_pfn, end_pfn; 3842 unsigned long size_pages; 3843 3844 start_pfn = max(early_node_map[i].start_pfn, 3845 zone_movable_pfn[nid]); 3846 end_pfn = early_node_map[i].end_pfn; 3847 if (start_pfn >= end_pfn) 3848 continue; 3849 3850 /* Account for what is only usable for kernelcore */ 3851 if (start_pfn < usable_startpfn) { 3852 unsigned long kernel_pages; 3853 kernel_pages = min(end_pfn, usable_startpfn) 3854 - start_pfn; 3855 3856 kernelcore_remaining -= min(kernel_pages, 3857 kernelcore_remaining); 3858 required_kernelcore -= min(kernel_pages, 3859 required_kernelcore); 3860 3861 /* Continue if range is now fully accounted */ 3862 if (end_pfn <= usable_startpfn) { 3863 3864 /* 3865 * Push zone_movable_pfn to the end so 3866 * that if we have to rebalance 3867 * kernelcore across nodes, we will 3868 * not double account here 3869 */ 3870 zone_movable_pfn[nid] = end_pfn; 3871 continue; 3872 } 3873 start_pfn = usable_startpfn; 3874 } 3875 3876 /* 3877 * The usable PFN range for ZONE_MOVABLE is from 3878 * start_pfn->end_pfn. Calculate size_pages as the 3879 * number of pages used as kernelcore 3880 */ 3881 size_pages = end_pfn - start_pfn; 3882 if (size_pages > kernelcore_remaining) 3883 size_pages = kernelcore_remaining; 3884 zone_movable_pfn[nid] = start_pfn + size_pages; 3885 3886 /* 3887 * Some kernelcore has been met, update counts and 3888 * break if the kernelcore for this node has been 3889 * satisified 3890 */ 3891 required_kernelcore -= min(required_kernelcore, 3892 size_pages); 3893 kernelcore_remaining -= size_pages; 3894 if (!kernelcore_remaining) 3895 break; 3896 } 3897 } 3898 3899 /* 3900 * If there is still required_kernelcore, we do another pass with one 3901 * less node in the count. This will push zone_movable_pfn[nid] further 3902 * along on the nodes that still have memory until kernelcore is 3903 * satisified 3904 */ 3905 usable_nodes--; 3906 if (usable_nodes && required_kernelcore > usable_nodes) 3907 goto restart; 3908 3909 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ 3910 for (nid = 0; nid < MAX_NUMNODES; nid++) 3911 zone_movable_pfn[nid] = 3912 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); 3913} 3914 3915/* Any regular memory on that node ? */ 3916static void check_for_regular_memory(pg_data_t *pgdat) 3917{ 3918#ifdef CONFIG_HIGHMEM 3919 enum zone_type zone_type; 3920 3921 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) { 3922 struct zone *zone = &pgdat->node_zones[zone_type]; 3923 if (zone->present_pages) 3924 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY); 3925 } 3926#endif 3927} 3928 3929/** 3930 * free_area_init_nodes - Initialise all pg_data_t and zone data 3931 * @max_zone_pfn: an array of max PFNs for each zone 3932 * 3933 * This will call free_area_init_node() for each active node in the system. 3934 * Using the page ranges provided by add_active_range(), the size of each 3935 * zone in each node and their holes is calculated. If the maximum PFN 3936 * between two adjacent zones match, it is assumed that the zone is empty. 3937 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed 3938 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone 3939 * starts where the previous one ended. For example, ZONE_DMA32 starts 3940 * at arch_max_dma_pfn. 3941 */ 3942void __init free_area_init_nodes(unsigned long *max_zone_pfn) 3943{ 3944 unsigned long nid; 3945 enum zone_type i; 3946 3947 /* Sort early_node_map as initialisation assumes it is sorted */ 3948 sort_node_map(); 3949 3950 /* Record where the zone boundaries are */ 3951 memset(arch_zone_lowest_possible_pfn, 0, 3952 sizeof(arch_zone_lowest_possible_pfn)); 3953 memset(arch_zone_highest_possible_pfn, 0, 3954 sizeof(arch_zone_highest_possible_pfn)); 3955 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); 3956 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; 3957 for (i = 1; i < MAX_NR_ZONES; i++) { 3958 if (i == ZONE_MOVABLE) 3959 continue; 3960 arch_zone_lowest_possible_pfn[i] = 3961 arch_zone_highest_possible_pfn[i-1]; 3962 arch_zone_highest_possible_pfn[i] = 3963 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); 3964 } 3965 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0; 3966 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0; 3967 3968 /* Find the PFNs that ZONE_MOVABLE begins at in each node */ 3969 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); 3970 find_zone_movable_pfns_for_nodes(zone_movable_pfn); 3971 3972 /* Print out the zone ranges */ 3973 printk("Zone PFN ranges:\n"); 3974 for (i = 0; i < MAX_NR_ZONES; i++) { 3975 if (i == ZONE_MOVABLE) 3976 continue; 3977 printk(" %-8s %0#10lx -> %0#10lx\n", 3978 zone_names[i], 3979 arch_zone_lowest_possible_pfn[i], 3980 arch_zone_highest_possible_pfn[i]); 3981 } 3982 3983 /* Print out the PFNs ZONE_MOVABLE begins at in each node */ 3984 printk("Movable zone start PFN for each node\n"); 3985 for (i = 0; i < MAX_NUMNODES; i++) { 3986 if (zone_movable_pfn[i]) 3987 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]); 3988 } 3989 3990 /* Print out the early_node_map[] */ 3991 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries); 3992 for (i = 0; i < nr_nodemap_entries; i++) 3993 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid, 3994 early_node_map[i].start_pfn, 3995 early_node_map[i].end_pfn); 3996 3997 /* Initialise every node */ 3998 mminit_verify_pageflags_layout(); 3999 setup_nr_node_ids(); 4000 for_each_online_node(nid) { 4001 pg_data_t *pgdat = NODE_DATA(nid); 4002 free_area_init_node(nid, NULL, 4003 find_min_pfn_for_node(nid), NULL); 4004 4005 /* Any memory on that node */ 4006 if (pgdat->node_present_pages) 4007 node_set_state(nid, N_HIGH_MEMORY); 4008 check_for_regular_memory(pgdat); 4009 } 4010} 4011 4012static int __init cmdline_parse_core(char *p, unsigned long *core) 4013{ 4014 unsigned long long coremem; 4015 if (!p) 4016 return -EINVAL; 4017 4018 coremem = memparse(p, &p); 4019 *core = coremem >> PAGE_SHIFT; 4020 4021 /* Paranoid check that UL is enough for the coremem value */ 4022 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); 4023 4024 return 0; 4025} 4026 4027/* 4028 * kernelcore=size sets the amount of memory for use for allocations that 4029 * cannot be reclaimed or migrated. 4030 */ 4031static int __init cmdline_parse_kernelcore(char *p) 4032{ 4033 return cmdline_parse_core(p, &required_kernelcore); 4034} 4035 4036/* 4037 * movablecore=size sets the amount of memory for use for allocations that 4038 * can be reclaimed or migrated. 4039 */ 4040static int __init cmdline_parse_movablecore(char *p) 4041{ 4042 return cmdline_parse_core(p, &required_movablecore); 4043} 4044 4045early_param("kernelcore", cmdline_parse_kernelcore); 4046early_param("movablecore", cmdline_parse_movablecore); 4047 4048#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 4049 4050/** 4051 * set_dma_reserve - set the specified number of pages reserved in the first zone 4052 * @new_dma_reserve: The number of pages to mark reserved 4053 * 4054 * The per-cpu batchsize and zone watermarks are determined by present_pages. 4055 * In the DMA zone, a significant percentage may be consumed by kernel image 4056 * and other unfreeable allocations which can skew the watermarks badly. This 4057 * function may optionally be used to account for unfreeable pages in the 4058 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and 4059 * smaller per-cpu batchsize. 4060 */ 4061void __init set_dma_reserve(unsigned long new_dma_reserve) 4062{ 4063 dma_reserve = new_dma_reserve; 4064} 4065 4066#ifndef CONFIG_NEED_MULTIPLE_NODES 4067struct pglist_data contig_page_data = { .bdata = &bootmem_node_data[0] }; 4068EXPORT_SYMBOL(contig_page_data); 4069#endif 4070 4071void __init free_area_init(unsigned long *zones_size) 4072{ 4073 free_area_init_node(0, zones_size, 4074 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 4075} 4076 4077static int page_alloc_cpu_notify(struct notifier_block *self, 4078 unsigned long action, void *hcpu) 4079{ 4080 int cpu = (unsigned long)hcpu; 4081 4082 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { 4083 drain_pages(cpu); 4084 4085 /* 4086 * Spill the event counters of the dead processor 4087 * into the current processors event counters. 4088 * This artificially elevates the count of the current 4089 * processor. 4090 */ 4091 vm_events_fold_cpu(cpu); 4092 4093 /* 4094 * Zero the differential counters of the dead processor 4095 * so that the vm statistics are consistent. 4096 * 4097 * This is only okay since the processor is dead and cannot 4098 * race with what we are doing. 4099 */ 4100 refresh_cpu_vm_stats(cpu); 4101 } 4102 return NOTIFY_OK; 4103} 4104 4105void __init page_alloc_init(void) 4106{ 4107 hotcpu_notifier(page_alloc_cpu_notify, 0); 4108} 4109 4110/* 4111 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio 4112 * or min_free_kbytes changes. 4113 */ 4114static void calculate_totalreserve_pages(void) 4115{ 4116 struct pglist_data *pgdat; 4117 unsigned long reserve_pages = 0; 4118 enum zone_type i, j; 4119 4120 for_each_online_pgdat(pgdat) { 4121 for (i = 0; i < MAX_NR_ZONES; i++) { 4122 struct zone *zone = pgdat->node_zones + i; 4123 unsigned long max = 0; 4124 4125 /* Find valid and maximum lowmem_reserve in the zone */ 4126 for (j = i; j < MAX_NR_ZONES; j++) { 4127 if (zone->lowmem_reserve[j] > max) 4128 max = zone->lowmem_reserve[j]; 4129 } 4130 4131 /* we treat pages_high as reserved pages. */ 4132 max += zone->pages_high; 4133 4134 if (max > zone->present_pages) 4135 max = zone->present_pages; 4136 reserve_pages += max; 4137 } 4138 } 4139 totalreserve_pages = reserve_pages; 4140} 4141 4142/* 4143 * setup_per_zone_lowmem_reserve - called whenever 4144 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 4145 * has a correct pages reserved value, so an adequate number of 4146 * pages are left in the zone after a successful __alloc_pages(). 4147 */ 4148static void setup_per_zone_lowmem_reserve(void) 4149{ 4150 struct pglist_data *pgdat; 4151 enum zone_type j, idx; 4152 4153 for_each_online_pgdat(pgdat) { 4154 for (j = 0; j < MAX_NR_ZONES; j++) { 4155 struct zone *zone = pgdat->node_zones + j; 4156 unsigned long present_pages = zone->present_pages; 4157 4158 zone->lowmem_reserve[j] = 0; 4159 4160 idx = j; 4161 while (idx) { 4162 struct zone *lower_zone; 4163 4164 idx--; 4165 4166 if (sysctl_lowmem_reserve_ratio[idx] < 1) 4167 sysctl_lowmem_reserve_ratio[idx] = 1; 4168 4169 lower_zone = pgdat->node_zones + idx; 4170 lower_zone->lowmem_reserve[j] = present_pages / 4171 sysctl_lowmem_reserve_ratio[idx]; 4172 present_pages += lower_zone->present_pages; 4173 } 4174 } 4175 } 4176 4177 /* update totalreserve_pages */ 4178 calculate_totalreserve_pages(); 4179} 4180 4181/** 4182 * setup_per_zone_pages_min - called when min_free_kbytes changes. 4183 * 4184 * Ensures that the pages_{min,low,high} values for each zone are set correctly 4185 * with respect to min_free_kbytes. 4186 */ 4187void setup_per_zone_pages_min(void) 4188{ 4189 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 4190 unsigned long lowmem_pages = 0; 4191 struct zone *zone; 4192 unsigned long flags; 4193 4194 /* Calculate total number of !ZONE_HIGHMEM pages */ 4195 for_each_zone(zone) { 4196 if (!is_highmem(zone)) 4197 lowmem_pages += zone->present_pages; 4198 } 4199 4200 for_each_zone(zone) { 4201 u64 tmp; 4202 4203 spin_lock_irqsave(&zone->lru_lock, flags); 4204 tmp = (u64)pages_min * zone->present_pages; 4205 do_div(tmp, lowmem_pages); 4206 if (is_highmem(zone)) { 4207 /* 4208 * __GFP_HIGH and PF_MEMALLOC allocations usually don't 4209 * need highmem pages, so cap pages_min to a small 4210 * value here. 4211 * 4212 * The (pages_high-pages_low) and (pages_low-pages_min) 4213 * deltas controls asynch page reclaim, and so should 4214 * not be capped for highmem. 4215 */ 4216 int min_pages; 4217 4218 min_pages = zone->present_pages / 1024; 4219 if (min_pages < SWAP_CLUSTER_MAX) 4220 min_pages = SWAP_CLUSTER_MAX; 4221 if (min_pages > 128) 4222 min_pages = 128; 4223 zone->pages_min = min_pages; 4224 } else { 4225 /* 4226 * If it's a lowmem zone, reserve a number of pages 4227 * proportionate to the zone's size. 4228 */ 4229 zone->pages_min = tmp; 4230 } 4231 4232 zone->pages_low = zone->pages_min + (tmp >> 2); 4233 zone->pages_high = zone->pages_min + (tmp >> 1); 4234 setup_zone_migrate_reserve(zone); 4235 spin_unlock_irqrestore(&zone->lru_lock, flags); 4236 } 4237 4238 /* update totalreserve_pages */ 4239 calculate_totalreserve_pages(); 4240} 4241 4242/* 4243 * Initialise min_free_kbytes. 4244 * 4245 * For small machines we want it small (128k min). For large machines 4246 * we want it large (64MB max). But it is not linear, because network 4247 * bandwidth does not increase linearly with machine size. We use 4248 * 4249 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 4250 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 4251 * 4252 * which yields 4253 * 4254 * 16MB: 512k 4255 * 32MB: 724k 4256 * 64MB: 1024k 4257 * 128MB: 1448k 4258 * 256MB: 2048k 4259 * 512MB: 2896k 4260 * 1024MB: 4096k 4261 * 2048MB: 5792k 4262 * 4096MB: 8192k 4263 * 8192MB: 11584k 4264 * 16384MB: 16384k 4265 */ 4266static int __init init_per_zone_pages_min(void) 4267{ 4268 unsigned long lowmem_kbytes; 4269 4270 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 4271 4272 min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 4273 if (min_free_kbytes < 128) 4274 min_free_kbytes = 128; 4275 if (min_free_kbytes > 65536) 4276 min_free_kbytes = 65536; 4277 setup_per_zone_pages_min(); 4278 setup_per_zone_lowmem_reserve(); 4279 return 0; 4280} 4281module_init(init_per_zone_pages_min) 4282 4283/* 4284 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 4285 * that we can call two helper functions whenever min_free_kbytes 4286 * changes. 4287 */ 4288int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 4289 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4290{ 4291 proc_dointvec(table, write, file, buffer, length, ppos); 4292 if (write) 4293 setup_per_zone_pages_min(); 4294 return 0; 4295} 4296 4297#ifdef CONFIG_NUMA 4298int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, 4299 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4300{ 4301 struct zone *zone; 4302 int rc; 4303 4304 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4305 if (rc) 4306 return rc; 4307 4308 for_each_zone(zone) 4309 zone->min_unmapped_pages = (zone->present_pages * 4310 sysctl_min_unmapped_ratio) / 100; 4311 return 0; 4312} 4313 4314int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write, 4315 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4316{ 4317 struct zone *zone; 4318 int rc; 4319 4320 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4321 if (rc) 4322 return rc; 4323 4324 for_each_zone(zone) 4325 zone->min_slab_pages = (zone->present_pages * 4326 sysctl_min_slab_ratio) / 100; 4327 return 0; 4328} 4329#endif 4330 4331/* 4332 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 4333 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 4334 * whenever sysctl_lowmem_reserve_ratio changes. 4335 * 4336 * The reserve ratio obviously has absolutely no relation with the 4337 * pages_min watermarks. The lowmem reserve ratio can only make sense 4338 * if in function of the boot time zone sizes. 4339 */ 4340int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, 4341 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4342{ 4343 proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4344 setup_per_zone_lowmem_reserve(); 4345 return 0; 4346} 4347 4348/* 4349 * percpu_pagelist_fraction - changes the pcp->high for each zone on each 4350 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist 4351 * can have before it gets flushed back to buddy allocator. 4352 */ 4353 4354int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, 4355 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4356{ 4357 struct zone *zone; 4358 unsigned int cpu; 4359 int ret; 4360 4361 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4362 if (!write || (ret == -EINVAL)) 4363 return ret; 4364 for_each_zone(zone) { 4365 for_each_online_cpu(cpu) { 4366 unsigned long high; 4367 high = zone->present_pages / percpu_pagelist_fraction; 4368 setup_pagelist_highmark(zone_pcp(zone, cpu), high); 4369 } 4370 } 4371 return 0; 4372} 4373 4374int hashdist = HASHDIST_DEFAULT; 4375 4376#ifdef CONFIG_NUMA 4377static int __init set_hashdist(char *str) 4378{ 4379 if (!str) 4380 return 0; 4381 hashdist = simple_strtoul(str, &str, 0); 4382 return 1; 4383} 4384__setup("hashdist=", set_hashdist); 4385#endif 4386 4387/* 4388 * allocate a large system hash table from bootmem 4389 * - it is assumed that the hash table must contain an exact power-of-2 4390 * quantity of entries 4391 * - limit is the number of hash buckets, not the total allocation size 4392 */ 4393void *__init alloc_large_system_hash(const char *tablename, 4394 unsigned long bucketsize, 4395 unsigned long numentries, 4396 int scale, 4397 int flags, 4398 unsigned int *_hash_shift, 4399 unsigned int *_hash_mask, 4400 unsigned long limit) 4401{ 4402 unsigned long long max = limit; 4403 unsigned long log2qty, size; 4404 void *table = NULL; 4405 4406 /* allow the kernel cmdline to have a say */ 4407 if (!numentries) { 4408 /* round applicable memory size up to nearest megabyte */ 4409 numentries = nr_kernel_pages; 4410 numentries += (1UL << (20 - PAGE_SHIFT)) - 1; 4411 numentries >>= 20 - PAGE_SHIFT; 4412 numentries <<= 20 - PAGE_SHIFT; 4413 4414 /* limit to 1 bucket per 2^scale bytes of low memory */ 4415 if (scale > PAGE_SHIFT) 4416 numentries >>= (scale - PAGE_SHIFT); 4417 else 4418 numentries <<= (PAGE_SHIFT - scale); 4419 4420 /* Make sure we've got at least a 0-order allocation.. */ 4421 if (unlikely((numentries * bucketsize) < PAGE_SIZE)) 4422 numentries = PAGE_SIZE / bucketsize; 4423 } 4424 numentries = roundup_pow_of_two(numentries); 4425 4426 /* limit allocation size to 1/16 total memory by default */ 4427 if (max == 0) { 4428 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 4429 do_div(max, bucketsize); 4430 } 4431 4432 if (numentries > max) 4433 numentries = max; 4434 4435 log2qty = ilog2(numentries); 4436 4437 do { 4438 size = bucketsize << log2qty; 4439 if (flags & HASH_EARLY) 4440 table = alloc_bootmem_nopanic(size); 4441 else if (hashdist) 4442 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 4443 else { 4444 unsigned long order = get_order(size); 4445 table = (void*) __get_free_pages(GFP_ATOMIC, order); 4446 /* 4447 * If bucketsize is not a power-of-two, we may free 4448 * some pages at the end of hash table. 4449 */ 4450 if (table) { 4451 unsigned long alloc_end = (unsigned long)table + 4452 (PAGE_SIZE << order); 4453 unsigned long used = (unsigned long)table + 4454 PAGE_ALIGN(size); 4455 split_page(virt_to_page(table), order); 4456 while (used < alloc_end) { 4457 free_page(used); 4458 used += PAGE_SIZE; 4459 } 4460 } 4461 } 4462 } while (!table && size > PAGE_SIZE && --log2qty); 4463 4464 if (!table) 4465 panic("Failed to allocate %s hash table\n", tablename); 4466 4467 printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n", 4468 tablename, 4469 (1U << log2qty), 4470 ilog2(size) - PAGE_SHIFT, 4471 size); 4472 4473 if (_hash_shift) 4474 *_hash_shift = log2qty; 4475 if (_hash_mask) 4476 *_hash_mask = (1 << log2qty) - 1; 4477 4478 return table; 4479} 4480 4481#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE 4482struct page *pfn_to_page(unsigned long pfn) 4483{ 4484 return __pfn_to_page(pfn); 4485} 4486unsigned long page_to_pfn(struct page *page) 4487{ 4488 return __page_to_pfn(page); 4489} 4490EXPORT_SYMBOL(pfn_to_page); 4491EXPORT_SYMBOL(page_to_pfn); 4492#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */ 4493 4494/* Return a pointer to the bitmap storing bits affecting a block of pages */ 4495static inline unsigned long *get_pageblock_bitmap(struct zone *zone, 4496 unsigned long pfn) 4497{ 4498#ifdef CONFIG_SPARSEMEM 4499 return __pfn_to_section(pfn)->pageblock_flags; 4500#else 4501 return zone->pageblock_flags; 4502#endif /* CONFIG_SPARSEMEM */ 4503} 4504 4505static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) 4506{ 4507#ifdef CONFIG_SPARSEMEM 4508 pfn &= (PAGES_PER_SECTION-1); 4509 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 4510#else 4511 pfn = pfn - zone->zone_start_pfn; 4512 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 4513#endif /* CONFIG_SPARSEMEM */ 4514} 4515 4516/** 4517 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages 4518 * @page: The page within the block of interest 4519 * @start_bitidx: The first bit of interest to retrieve 4520 * @end_bitidx: The last bit of interest 4521 * returns pageblock_bits flags 4522 */ 4523unsigned long get_pageblock_flags_group(struct page *page, 4524 int start_bitidx, int end_bitidx) 4525{ 4526 struct zone *zone; 4527 unsigned long *bitmap; 4528 unsigned long pfn, bitidx; 4529 unsigned long flags = 0; 4530 unsigned long value = 1; 4531 4532 zone = page_zone(page); 4533 pfn = page_to_pfn(page); 4534 bitmap = get_pageblock_bitmap(zone, pfn); 4535 bitidx = pfn_to_bitidx(zone, pfn); 4536 4537 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 4538 if (test_bit(bitidx + start_bitidx, bitmap)) 4539 flags |= value; 4540 4541 return flags; 4542} 4543 4544/** 4545 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages 4546 * @page: The page within the block of interest 4547 * @start_bitidx: The first bit of interest 4548 * @end_bitidx: The last bit of interest 4549 * @flags: The flags to set 4550 */ 4551void set_pageblock_flags_group(struct page *page, unsigned long flags, 4552 int start_bitidx, int end_bitidx) 4553{ 4554 struct zone *zone; 4555 unsigned long *bitmap; 4556 unsigned long pfn, bitidx; 4557 unsigned long value = 1; 4558 4559 zone = page_zone(page); 4560 pfn = page_to_pfn(page); 4561 bitmap = get_pageblock_bitmap(zone, pfn); 4562 bitidx = pfn_to_bitidx(zone, pfn); 4563 VM_BUG_ON(pfn < zone->zone_start_pfn); 4564 VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages); 4565 4566 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 4567 if (flags & value) 4568 __set_bit(bitidx + start_bitidx, bitmap); 4569 else 4570 __clear_bit(bitidx + start_bitidx, bitmap); 4571} 4572 4573/* 4574 * This is designed as sub function...plz see page_isolation.c also. 4575 * set/clear page block's type to be ISOLATE. 4576 * page allocater never alloc memory from ISOLATE block. 4577 */ 4578 4579int set_migratetype_isolate(struct page *page) 4580{ 4581 struct zone *zone; 4582 unsigned long flags; 4583 int ret = -EBUSY; 4584 4585 zone = page_zone(page); 4586 spin_lock_irqsave(&zone->lock, flags); 4587 /* 4588 * In future, more migrate types will be able to be isolation target. 4589 */ 4590 if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE) 4591 goto out; 4592 set_pageblock_migratetype(page, MIGRATE_ISOLATE); 4593 move_freepages_block(zone, page, MIGRATE_ISOLATE); 4594 ret = 0; 4595out: 4596 spin_unlock_irqrestore(&zone->lock, flags); 4597 if (!ret) 4598 drain_all_pages(); 4599 return ret; 4600} 4601 4602void unset_migratetype_isolate(struct page *page) 4603{ 4604 struct zone *zone; 4605 unsigned long flags; 4606 zone = page_zone(page); 4607 spin_lock_irqsave(&zone->lock, flags); 4608 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE) 4609 goto out; 4610 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 4611 move_freepages_block(zone, page, MIGRATE_MOVABLE); 4612out: 4613 spin_unlock_irqrestore(&zone->lock, flags); 4614} 4615 4616#ifdef CONFIG_MEMORY_HOTREMOVE 4617/* 4618 * All pages in the range must be isolated before calling this. 4619 */ 4620void 4621__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) 4622{ 4623 struct page *page; 4624 struct zone *zone; 4625 int order, i; 4626 unsigned long pfn; 4627 unsigned long flags; 4628 /* find the first valid pfn */ 4629 for (pfn = start_pfn; pfn < end_pfn; pfn++) 4630 if (pfn_valid(pfn)) 4631 break; 4632 if (pfn == end_pfn) 4633 return; 4634 zone = page_zone(pfn_to_page(pfn)); 4635 spin_lock_irqsave(&zone->lock, flags); 4636 pfn = start_pfn; 4637 while (pfn < end_pfn) { 4638 if (!pfn_valid(pfn)) { 4639 pfn++; 4640 continue; 4641 } 4642 page = pfn_to_page(pfn); 4643 BUG_ON(page_count(page)); 4644 BUG_ON(!PageBuddy(page)); 4645 order = page_order(page); 4646#ifdef CONFIG_DEBUG_VM 4647 printk(KERN_INFO "remove from free list %lx %d %lx\n", 4648 pfn, 1 << order, end_pfn); 4649#endif 4650 list_del(&page->lru); 4651 rmv_page_order(page); 4652 zone->free_area[order].nr_free--; 4653 __mod_zone_page_state(zone, NR_FREE_PAGES, 4654 - (1UL << order)); 4655 for (i = 0; i < (1 << order); i++) 4656 SetPageReserved((page+i)); 4657 pfn += (1 << order); 4658 } 4659 spin_unlock_irqrestore(&zone->lock, flags); 4660} 4661#endif 4662