page_alloc.c revision 5f8dcc21211a3d4e3a7a5ca366b469fb88117f61
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/kmemcheck.h> 27#include <linux/module.h> 28#include <linux/suspend.h> 29#include <linux/pagevec.h> 30#include <linux/blkdev.h> 31#include <linux/slab.h> 32#include <linux/oom.h> 33#include <linux/notifier.h> 34#include <linux/topology.h> 35#include <linux/sysctl.h> 36#include <linux/cpu.h> 37#include <linux/cpuset.h> 38#include <linux/memory_hotplug.h> 39#include <linux/nodemask.h> 40#include <linux/vmalloc.h> 41#include <linux/mempolicy.h> 42#include <linux/stop_machine.h> 43#include <linux/sort.h> 44#include <linux/pfn.h> 45#include <linux/backing-dev.h> 46#include <linux/fault-inject.h> 47#include <linux/page-isolation.h> 48#include <linux/page_cgroup.h> 49#include <linux/debugobjects.h> 50#include <linux/kmemleak.h> 51#include <trace/events/kmem.h> 52 53#include <asm/tlbflush.h> 54#include <asm/div64.h> 55#include "internal.h" 56 57/* 58 * Array of node states. 59 */ 60nodemask_t node_states[NR_NODE_STATES] __read_mostly = { 61 [N_POSSIBLE] = NODE_MASK_ALL, 62 [N_ONLINE] = { { [0] = 1UL } }, 63#ifndef CONFIG_NUMA 64 [N_NORMAL_MEMORY] = { { [0] = 1UL } }, 65#ifdef CONFIG_HIGHMEM 66 [N_HIGH_MEMORY] = { { [0] = 1UL } }, 67#endif 68 [N_CPU] = { { [0] = 1UL } }, 69#endif /* NUMA */ 70}; 71EXPORT_SYMBOL(node_states); 72 73unsigned long totalram_pages __read_mostly; 74unsigned long totalreserve_pages __read_mostly; 75unsigned long highest_memmap_pfn __read_mostly; 76int percpu_pagelist_fraction; 77gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; 78 79#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 80int pageblock_order __read_mostly; 81#endif 82 83static void __free_pages_ok(struct page *page, unsigned int order); 84 85/* 86 * results with 256, 32 in the lowmem_reserve sysctl: 87 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) 88 * 1G machine -> (16M dma, 784M normal, 224M high) 89 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA 90 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL 91 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA 92 * 93 * TBD: should special case ZONE_DMA32 machines here - in those we normally 94 * don't need any ZONE_NORMAL reservation 95 */ 96int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 97#ifdef CONFIG_ZONE_DMA 98 256, 99#endif 100#ifdef CONFIG_ZONE_DMA32 101 256, 102#endif 103#ifdef CONFIG_HIGHMEM 104 32, 105#endif 106 32, 107}; 108 109EXPORT_SYMBOL(totalram_pages); 110 111static char * const zone_names[MAX_NR_ZONES] = { 112#ifdef CONFIG_ZONE_DMA 113 "DMA", 114#endif 115#ifdef CONFIG_ZONE_DMA32 116 "DMA32", 117#endif 118 "Normal", 119#ifdef CONFIG_HIGHMEM 120 "HighMem", 121#endif 122 "Movable", 123}; 124 125int min_free_kbytes = 1024; 126 127static unsigned long __meminitdata nr_kernel_pages; 128static unsigned long __meminitdata nr_all_pages; 129static unsigned long __meminitdata dma_reserve; 130 131#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 132 /* 133 * MAX_ACTIVE_REGIONS determines the maximum number of distinct 134 * ranges of memory (RAM) that may be registered with add_active_range(). 135 * Ranges passed to add_active_range() will be merged if possible 136 * so the number of times add_active_range() can be called is 137 * related to the number of nodes and the number of holes 138 */ 139 #ifdef CONFIG_MAX_ACTIVE_REGIONS 140 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */ 141 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS 142 #else 143 #if MAX_NUMNODES >= 32 144 /* If there can be many nodes, allow up to 50 holes per node */ 145 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50) 146 #else 147 /* By default, allow up to 256 distinct regions */ 148 #define MAX_ACTIVE_REGIONS 256 149 #endif 150 #endif 151 152 static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS]; 153 static int __meminitdata nr_nodemap_entries; 154 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; 155 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; 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; 167int nr_online_nodes __read_mostly = 1; 168EXPORT_SYMBOL(nr_node_ids); 169EXPORT_SYMBOL(nr_online_nodes); 170#endif 171 172int page_group_by_mobility_disabled __read_mostly; 173 174static void set_pageblock_migratetype(struct page *page, int migratetype) 175{ 176 177 if (unlikely(page_group_by_mobility_disabled)) 178 migratetype = MIGRATE_UNMOVABLE; 179 180 set_pageblock_flags_group(page, (unsigned long)migratetype, 181 PB_migrate, PB_migrate_end); 182} 183 184bool oom_killer_disabled __read_mostly; 185 186#ifdef CONFIG_DEBUG_VM 187static int page_outside_zone_boundaries(struct zone *zone, struct page *page) 188{ 189 int ret = 0; 190 unsigned seq; 191 unsigned long pfn = page_to_pfn(page); 192 193 do { 194 seq = zone_span_seqbegin(zone); 195 if (pfn >= zone->zone_start_pfn + zone->spanned_pages) 196 ret = 1; 197 else if (pfn < zone->zone_start_pfn) 198 ret = 1; 199 } while (zone_span_seqretry(zone, seq)); 200 201 return ret; 202} 203 204static int page_is_consistent(struct zone *zone, struct page *page) 205{ 206 if (!pfn_valid_within(page_to_pfn(page))) 207 return 0; 208 if (zone != page_zone(page)) 209 return 0; 210 211 return 1; 212} 213/* 214 * Temporary debugging check for pages not lying within a given zone. 215 */ 216static int bad_range(struct zone *zone, struct page *page) 217{ 218 if (page_outside_zone_boundaries(zone, page)) 219 return 1; 220 if (!page_is_consistent(zone, page)) 221 return 1; 222 223 return 0; 224} 225#else 226static inline int bad_range(struct zone *zone, struct page *page) 227{ 228 return 0; 229} 230#endif 231 232static void bad_page(struct page *page) 233{ 234 static unsigned long resume; 235 static unsigned long nr_shown; 236 static unsigned long nr_unshown; 237 238 /* 239 * Allow a burst of 60 reports, then keep quiet for that minute; 240 * or allow a steady drip of one report per second. 241 */ 242 if (nr_shown == 60) { 243 if (time_before(jiffies, resume)) { 244 nr_unshown++; 245 goto out; 246 } 247 if (nr_unshown) { 248 printk(KERN_ALERT 249 "BUG: Bad page state: %lu messages suppressed\n", 250 nr_unshown); 251 nr_unshown = 0; 252 } 253 nr_shown = 0; 254 } 255 if (nr_shown++ == 0) 256 resume = jiffies + 60 * HZ; 257 258 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n", 259 current->comm, page_to_pfn(page)); 260 printk(KERN_ALERT 261 "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n", 262 page, (void *)page->flags, page_count(page), 263 page_mapcount(page), page->mapping, page->index); 264 265 dump_stack(); 266out: 267 /* Leave bad fields for debug, except PageBuddy could make trouble */ 268 __ClearPageBuddy(page); 269 add_taint(TAINT_BAD_PAGE); 270} 271 272/* 273 * Higher-order pages are called "compound pages". They are structured thusly: 274 * 275 * The first PAGE_SIZE page is called the "head page". 276 * 277 * The remaining PAGE_SIZE pages are called "tail pages". 278 * 279 * All pages have PG_compound set. All pages have their ->private pointing at 280 * the head page (even the head page has this). 281 * 282 * The first tail page's ->lru.next holds the address of the compound page's 283 * put_page() function. Its ->lru.prev holds the order of allocation. 284 * This usage means that zero-order pages may not be compound. 285 */ 286 287static void free_compound_page(struct page *page) 288{ 289 __free_pages_ok(page, compound_order(page)); 290} 291 292void prep_compound_page(struct page *page, unsigned long order) 293{ 294 int i; 295 int nr_pages = 1 << order; 296 297 set_compound_page_dtor(page, free_compound_page); 298 set_compound_order(page, order); 299 __SetPageHead(page); 300 for (i = 1; i < nr_pages; i++) { 301 struct page *p = page + i; 302 303 __SetPageTail(p); 304 p->first_page = page; 305 } 306} 307 308static int destroy_compound_page(struct page *page, unsigned long order) 309{ 310 int i; 311 int nr_pages = 1 << order; 312 int bad = 0; 313 314 if (unlikely(compound_order(page) != order) || 315 unlikely(!PageHead(page))) { 316 bad_page(page); 317 bad++; 318 } 319 320 __ClearPageHead(page); 321 322 for (i = 1; i < nr_pages; i++) { 323 struct page *p = page + i; 324 325 if (unlikely(!PageTail(p) || (p->first_page != page))) { 326 bad_page(page); 327 bad++; 328 } 329 __ClearPageTail(p); 330 } 331 332 return bad; 333} 334 335static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) 336{ 337 int i; 338 339 /* 340 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO 341 * and __GFP_HIGHMEM from hard or soft interrupt context. 342 */ 343 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); 344 for (i = 0; i < (1 << order); i++) 345 clear_highpage(page + i); 346} 347 348static inline void set_page_order(struct page *page, int order) 349{ 350 set_page_private(page, order); 351 __SetPageBuddy(page); 352} 353 354static inline void rmv_page_order(struct page *page) 355{ 356 __ClearPageBuddy(page); 357 set_page_private(page, 0); 358} 359 360/* 361 * Locate the struct page for both the matching buddy in our 362 * pair (buddy1) and the combined O(n+1) page they form (page). 363 * 364 * 1) Any buddy B1 will have an order O twin B2 which satisfies 365 * the following equation: 366 * B2 = B1 ^ (1 << O) 367 * For example, if the starting buddy (buddy2) is #8 its order 368 * 1 buddy is #10: 369 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 370 * 371 * 2) Any buddy B will have an order O+1 parent P which 372 * satisfies the following equation: 373 * P = B & ~(1 << O) 374 * 375 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 376 */ 377static inline struct page * 378__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order) 379{ 380 unsigned long buddy_idx = page_idx ^ (1 << order); 381 382 return page + (buddy_idx - page_idx); 383} 384 385static inline unsigned long 386__find_combined_index(unsigned long page_idx, unsigned int order) 387{ 388 return (page_idx & ~(1 << order)); 389} 390 391/* 392 * This function checks whether a page is free && is the buddy 393 * we can do coalesce a page and its buddy if 394 * (a) the buddy is not in a hole && 395 * (b) the buddy is in the buddy system && 396 * (c) a page and its buddy have the same order && 397 * (d) a page and its buddy are in the same zone. 398 * 399 * For recording whether a page is in the buddy system, we use PG_buddy. 400 * Setting, clearing, and testing PG_buddy is serialized by zone->lock. 401 * 402 * For recording page's order, we use page_private(page). 403 */ 404static inline int page_is_buddy(struct page *page, struct page *buddy, 405 int order) 406{ 407 if (!pfn_valid_within(page_to_pfn(buddy))) 408 return 0; 409 410 if (page_zone_id(page) != page_zone_id(buddy)) 411 return 0; 412 413 if (PageBuddy(buddy) && page_order(buddy) == order) { 414 VM_BUG_ON(page_count(buddy) != 0); 415 return 1; 416 } 417 return 0; 418} 419 420/* 421 * Freeing function for a buddy system allocator. 422 * 423 * The concept of a buddy system is to maintain direct-mapped table 424 * (containing bit values) for memory blocks of various "orders". 425 * The bottom level table contains the map for the smallest allocatable 426 * units of memory (here, pages), and each level above it describes 427 * pairs of units from the levels below, hence, "buddies". 428 * At a high level, all that happens here is marking the table entry 429 * at the bottom level available, and propagating the changes upward 430 * as necessary, plus some accounting needed to play nicely with other 431 * parts of the VM system. 432 * At each level, we keep a list of pages, which are heads of continuous 433 * free pages of length of (1 << order) and marked with PG_buddy. Page's 434 * order is recorded in page_private(page) field. 435 * So when we are allocating or freeing one, we can derive the state of the 436 * other. That is, if we allocate a small block, and both were 437 * free, the remainder of the region must be split into blocks. 438 * If a block is freed, and its buddy is also free, then this 439 * triggers coalescing into a block of larger size. 440 * 441 * -- wli 442 */ 443 444static inline void __free_one_page(struct page *page, 445 struct zone *zone, unsigned int order, 446 int migratetype) 447{ 448 unsigned long page_idx; 449 450 if (unlikely(PageCompound(page))) 451 if (unlikely(destroy_compound_page(page, order))) 452 return; 453 454 VM_BUG_ON(migratetype == -1); 455 456 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); 457 458 VM_BUG_ON(page_idx & ((1 << order) - 1)); 459 VM_BUG_ON(bad_range(zone, page)); 460 461 while (order < MAX_ORDER-1) { 462 unsigned long combined_idx; 463 struct page *buddy; 464 465 buddy = __page_find_buddy(page, page_idx, order); 466 if (!page_is_buddy(page, buddy, order)) 467 break; 468 469 /* Our buddy is free, merge with it and move up one order. */ 470 list_del(&buddy->lru); 471 zone->free_area[order].nr_free--; 472 rmv_page_order(buddy); 473 combined_idx = __find_combined_index(page_idx, order); 474 page = page + (combined_idx - page_idx); 475 page_idx = combined_idx; 476 order++; 477 } 478 set_page_order(page, order); 479 list_add(&page->lru, 480 &zone->free_area[order].free_list[migratetype]); 481 zone->free_area[order].nr_free++; 482} 483 484#ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT 485/* 486 * free_page_mlock() -- clean up attempts to free and mlocked() page. 487 * Page should not be on lru, so no need to fix that up. 488 * free_pages_check() will verify... 489 */ 490static inline void free_page_mlock(struct page *page) 491{ 492 __dec_zone_page_state(page, NR_MLOCK); 493 __count_vm_event(UNEVICTABLE_MLOCKFREED); 494} 495#else 496static void free_page_mlock(struct page *page) { } 497#endif 498 499static inline int free_pages_check(struct page *page) 500{ 501 if (unlikely(page_mapcount(page) | 502 (page->mapping != NULL) | 503 (atomic_read(&page->_count) != 0) | 504 (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) { 505 bad_page(page); 506 return 1; 507 } 508 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP) 509 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; 510 return 0; 511} 512 513/* 514 * Frees a number of pages from the PCP lists 515 * Assumes all pages on list are in same zone, and of same order. 516 * count is the number of pages to free. 517 * 518 * If the zone was previously in an "all pages pinned" state then look to 519 * see if this freeing clears that state. 520 * 521 * And clear the zone's pages_scanned counter, to hold off the "all pages are 522 * pinned" detection logic. 523 */ 524static void free_pcppages_bulk(struct zone *zone, int count, 525 struct per_cpu_pages *pcp) 526{ 527 int migratetype = 0; 528 529 spin_lock(&zone->lock); 530 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); 531 zone->pages_scanned = 0; 532 533 __mod_zone_page_state(zone, NR_FREE_PAGES, count); 534 while (count--) { 535 struct page *page; 536 struct list_head *list; 537 538 /* 539 * Remove pages from lists in a round-robin fashion. This spinning 540 * around potentially empty lists is bloody awful, alternatives that 541 * don't suck are welcome 542 */ 543 do { 544 if (++migratetype == MIGRATE_PCPTYPES) 545 migratetype = 0; 546 list = &pcp->lists[migratetype]; 547 } while (list_empty(list)); 548 549 page = list_entry(list->prev, struct page, lru); 550 /* have to delete it as __free_one_page list manipulates */ 551 list_del(&page->lru); 552 trace_mm_page_pcpu_drain(page, 0, migratetype); 553 __free_one_page(page, zone, 0, migratetype); 554 } 555 spin_unlock(&zone->lock); 556} 557 558static void free_one_page(struct zone *zone, struct page *page, int order, 559 int migratetype) 560{ 561 spin_lock(&zone->lock); 562 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); 563 zone->pages_scanned = 0; 564 565 __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order); 566 __free_one_page(page, zone, order, migratetype); 567 spin_unlock(&zone->lock); 568} 569 570static void __free_pages_ok(struct page *page, unsigned int order) 571{ 572 unsigned long flags; 573 int i; 574 int bad = 0; 575 int wasMlocked = __TestClearPageMlocked(page); 576 577 kmemcheck_free_shadow(page, order); 578 579 for (i = 0 ; i < (1 << order) ; ++i) 580 bad += free_pages_check(page + i); 581 if (bad) 582 return; 583 584 if (!PageHighMem(page)) { 585 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order); 586 debug_check_no_obj_freed(page_address(page), 587 PAGE_SIZE << order); 588 } 589 arch_free_page(page, order); 590 kernel_map_pages(page, 1 << order, 0); 591 592 local_irq_save(flags); 593 if (unlikely(wasMlocked)) 594 free_page_mlock(page); 595 __count_vm_events(PGFREE, 1 << order); 596 free_one_page(page_zone(page), page, order, 597 get_pageblock_migratetype(page)); 598 local_irq_restore(flags); 599} 600 601/* 602 * permit the bootmem allocator to evade page validation on high-order frees 603 */ 604void __meminit __free_pages_bootmem(struct page *page, unsigned int order) 605{ 606 if (order == 0) { 607 __ClearPageReserved(page); 608 set_page_count(page, 0); 609 set_page_refcounted(page); 610 __free_page(page); 611 } else { 612 int loop; 613 614 prefetchw(page); 615 for (loop = 0; loop < BITS_PER_LONG; loop++) { 616 struct page *p = &page[loop]; 617 618 if (loop + 1 < BITS_PER_LONG) 619 prefetchw(p + 1); 620 __ClearPageReserved(p); 621 set_page_count(p, 0); 622 } 623 624 set_page_refcounted(page); 625 __free_pages(page, order); 626 } 627} 628 629 630/* 631 * The order of subdivision here is critical for the IO subsystem. 632 * Please do not alter this order without good reasons and regression 633 * testing. Specifically, as large blocks of memory are subdivided, 634 * the order in which smaller blocks are delivered depends on the order 635 * they're subdivided in this function. This is the primary factor 636 * influencing the order in which pages are delivered to the IO 637 * subsystem according to empirical testing, and this is also justified 638 * by considering the behavior of a buddy system containing a single 639 * large block of memory acted on by a series of small allocations. 640 * This behavior is a critical factor in sglist merging's success. 641 * 642 * -- wli 643 */ 644static inline void expand(struct zone *zone, struct page *page, 645 int low, int high, struct free_area *area, 646 int migratetype) 647{ 648 unsigned long size = 1 << high; 649 650 while (high > low) { 651 area--; 652 high--; 653 size >>= 1; 654 VM_BUG_ON(bad_range(zone, &page[size])); 655 list_add(&page[size].lru, &area->free_list[migratetype]); 656 area->nr_free++; 657 set_page_order(&page[size], high); 658 } 659} 660 661/* 662 * This page is about to be returned from the page allocator 663 */ 664static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) 665{ 666 if (unlikely(page_mapcount(page) | 667 (page->mapping != NULL) | 668 (atomic_read(&page->_count) != 0) | 669 (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) { 670 bad_page(page); 671 return 1; 672 } 673 674 set_page_private(page, 0); 675 set_page_refcounted(page); 676 677 arch_alloc_page(page, order); 678 kernel_map_pages(page, 1 << order, 1); 679 680 if (gfp_flags & __GFP_ZERO) 681 prep_zero_page(page, order, gfp_flags); 682 683 if (order && (gfp_flags & __GFP_COMP)) 684 prep_compound_page(page, order); 685 686 return 0; 687} 688 689/* 690 * Go through the free lists for the given migratetype and remove 691 * the smallest available page from the freelists 692 */ 693static inline 694struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, 695 int migratetype) 696{ 697 unsigned int current_order; 698 struct free_area * area; 699 struct page *page; 700 701 /* Find a page of the appropriate size in the preferred list */ 702 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 703 area = &(zone->free_area[current_order]); 704 if (list_empty(&area->free_list[migratetype])) 705 continue; 706 707 page = list_entry(area->free_list[migratetype].next, 708 struct page, lru); 709 list_del(&page->lru); 710 rmv_page_order(page); 711 area->nr_free--; 712 expand(zone, page, order, current_order, area, migratetype); 713 return page; 714 } 715 716 return NULL; 717} 718 719 720/* 721 * This array describes the order lists are fallen back to when 722 * the free lists for the desirable migrate type are depleted 723 */ 724static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = { 725 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 726 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 727 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, 728 [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */ 729}; 730 731/* 732 * Move the free pages in a range to the free lists of the requested type. 733 * Note that start_page and end_pages are not aligned on a pageblock 734 * boundary. If alignment is required, use move_freepages_block() 735 */ 736static int move_freepages(struct zone *zone, 737 struct page *start_page, struct page *end_page, 738 int migratetype) 739{ 740 struct page *page; 741 unsigned long order; 742 int pages_moved = 0; 743 744#ifndef CONFIG_HOLES_IN_ZONE 745 /* 746 * page_zone is not safe to call in this context when 747 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant 748 * anyway as we check zone boundaries in move_freepages_block(). 749 * Remove at a later date when no bug reports exist related to 750 * grouping pages by mobility 751 */ 752 BUG_ON(page_zone(start_page) != page_zone(end_page)); 753#endif 754 755 for (page = start_page; page <= end_page;) { 756 /* Make sure we are not inadvertently changing nodes */ 757 VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone)); 758 759 if (!pfn_valid_within(page_to_pfn(page))) { 760 page++; 761 continue; 762 } 763 764 if (!PageBuddy(page)) { 765 page++; 766 continue; 767 } 768 769 order = page_order(page); 770 list_del(&page->lru); 771 list_add(&page->lru, 772 &zone->free_area[order].free_list[migratetype]); 773 page += 1 << order; 774 pages_moved += 1 << order; 775 } 776 777 return pages_moved; 778} 779 780static int move_freepages_block(struct zone *zone, struct page *page, 781 int migratetype) 782{ 783 unsigned long start_pfn, end_pfn; 784 struct page *start_page, *end_page; 785 786 start_pfn = page_to_pfn(page); 787 start_pfn = start_pfn & ~(pageblock_nr_pages-1); 788 start_page = pfn_to_page(start_pfn); 789 end_page = start_page + pageblock_nr_pages - 1; 790 end_pfn = start_pfn + pageblock_nr_pages - 1; 791 792 /* Do not cross zone boundaries */ 793 if (start_pfn < zone->zone_start_pfn) 794 start_page = page; 795 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages) 796 return 0; 797 798 return move_freepages(zone, start_page, end_page, migratetype); 799} 800 801static void change_pageblock_range(struct page *pageblock_page, 802 int start_order, int migratetype) 803{ 804 int nr_pageblocks = 1 << (start_order - pageblock_order); 805 806 while (nr_pageblocks--) { 807 set_pageblock_migratetype(pageblock_page, migratetype); 808 pageblock_page += pageblock_nr_pages; 809 } 810} 811 812/* Remove an element from the buddy allocator from the fallback list */ 813static inline struct page * 814__rmqueue_fallback(struct zone *zone, int order, int start_migratetype) 815{ 816 struct free_area * area; 817 int current_order; 818 struct page *page; 819 int migratetype, i; 820 821 /* Find the largest possible block of pages in the other list */ 822 for (current_order = MAX_ORDER-1; current_order >= order; 823 --current_order) { 824 for (i = 0; i < MIGRATE_TYPES - 1; i++) { 825 migratetype = fallbacks[start_migratetype][i]; 826 827 /* MIGRATE_RESERVE handled later if necessary */ 828 if (migratetype == MIGRATE_RESERVE) 829 continue; 830 831 area = &(zone->free_area[current_order]); 832 if (list_empty(&area->free_list[migratetype])) 833 continue; 834 835 page = list_entry(area->free_list[migratetype].next, 836 struct page, lru); 837 area->nr_free--; 838 839 /* 840 * If breaking a large block of pages, move all free 841 * pages to the preferred allocation list. If falling 842 * back for a reclaimable kernel allocation, be more 843 * agressive about taking ownership of free pages 844 */ 845 if (unlikely(current_order >= (pageblock_order >> 1)) || 846 start_migratetype == MIGRATE_RECLAIMABLE || 847 page_group_by_mobility_disabled) { 848 unsigned long pages; 849 pages = move_freepages_block(zone, page, 850 start_migratetype); 851 852 /* Claim the whole block if over half of it is free */ 853 if (pages >= (1 << (pageblock_order-1)) || 854 page_group_by_mobility_disabled) 855 set_pageblock_migratetype(page, 856 start_migratetype); 857 858 migratetype = start_migratetype; 859 } 860 861 /* Remove the page from the freelists */ 862 list_del(&page->lru); 863 rmv_page_order(page); 864 865 /* Take ownership for orders >= pageblock_order */ 866 if (current_order >= pageblock_order) 867 change_pageblock_range(page, current_order, 868 start_migratetype); 869 870 expand(zone, page, order, current_order, area, migratetype); 871 872 trace_mm_page_alloc_extfrag(page, order, current_order, 873 start_migratetype, migratetype); 874 875 return page; 876 } 877 } 878 879 return NULL; 880} 881 882/* 883 * Do the hard work of removing an element from the buddy allocator. 884 * Call me with the zone->lock already held. 885 */ 886static struct page *__rmqueue(struct zone *zone, unsigned int order, 887 int migratetype) 888{ 889 struct page *page; 890 891retry_reserve: 892 page = __rmqueue_smallest(zone, order, migratetype); 893 894 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) { 895 page = __rmqueue_fallback(zone, order, migratetype); 896 897 /* 898 * Use MIGRATE_RESERVE rather than fail an allocation. goto 899 * is used because __rmqueue_smallest is an inline function 900 * and we want just one call site 901 */ 902 if (!page) { 903 migratetype = MIGRATE_RESERVE; 904 goto retry_reserve; 905 } 906 } 907 908 trace_mm_page_alloc_zone_locked(page, order, migratetype); 909 return page; 910} 911 912/* 913 * Obtain a specified number of elements from the buddy allocator, all under 914 * a single hold of the lock, for efficiency. Add them to the supplied list. 915 * Returns the number of new pages which were placed at *list. 916 */ 917static int rmqueue_bulk(struct zone *zone, unsigned int order, 918 unsigned long count, struct list_head *list, 919 int migratetype, int cold) 920{ 921 int i; 922 923 spin_lock(&zone->lock); 924 for (i = 0; i < count; ++i) { 925 struct page *page = __rmqueue(zone, order, migratetype); 926 if (unlikely(page == NULL)) 927 break; 928 929 /* 930 * Split buddy pages returned by expand() are received here 931 * in physical page order. The page is added to the callers and 932 * list and the list head then moves forward. From the callers 933 * perspective, the linked list is ordered by page number in 934 * some conditions. This is useful for IO devices that can 935 * merge IO requests if the physical pages are ordered 936 * properly. 937 */ 938 if (likely(cold == 0)) 939 list_add(&page->lru, list); 940 else 941 list_add_tail(&page->lru, list); 942 set_page_private(page, migratetype); 943 list = &page->lru; 944 } 945 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); 946 spin_unlock(&zone->lock); 947 return i; 948} 949 950#ifdef CONFIG_NUMA 951/* 952 * Called from the vmstat counter updater to drain pagesets of this 953 * currently executing processor on remote nodes after they have 954 * expired. 955 * 956 * Note that this function must be called with the thread pinned to 957 * a single processor. 958 */ 959void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) 960{ 961 unsigned long flags; 962 int to_drain; 963 964 local_irq_save(flags); 965 if (pcp->count >= pcp->batch) 966 to_drain = pcp->batch; 967 else 968 to_drain = pcp->count; 969 free_pcppages_bulk(zone, to_drain, pcp); 970 pcp->count -= to_drain; 971 local_irq_restore(flags); 972} 973#endif 974 975/* 976 * Drain pages of the indicated processor. 977 * 978 * The processor must either be the current processor and the 979 * thread pinned to the current processor or a processor that 980 * is not online. 981 */ 982static void drain_pages(unsigned int cpu) 983{ 984 unsigned long flags; 985 struct zone *zone; 986 987 for_each_populated_zone(zone) { 988 struct per_cpu_pageset *pset; 989 struct per_cpu_pages *pcp; 990 991 pset = zone_pcp(zone, cpu); 992 993 pcp = &pset->pcp; 994 local_irq_save(flags); 995 free_pcppages_bulk(zone, pcp->count, pcp); 996 pcp->count = 0; 997 local_irq_restore(flags); 998 } 999} 1000 1001/* 1002 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 1003 */ 1004void drain_local_pages(void *arg) 1005{ 1006 drain_pages(smp_processor_id()); 1007} 1008 1009/* 1010 * Spill all the per-cpu pages from all CPUs back into the buddy allocator 1011 */ 1012void drain_all_pages(void) 1013{ 1014 on_each_cpu(drain_local_pages, NULL, 1); 1015} 1016 1017#ifdef CONFIG_HIBERNATION 1018 1019void mark_free_pages(struct zone *zone) 1020{ 1021 unsigned long pfn, max_zone_pfn; 1022 unsigned long flags; 1023 int order, t; 1024 struct list_head *curr; 1025 1026 if (!zone->spanned_pages) 1027 return; 1028 1029 spin_lock_irqsave(&zone->lock, flags); 1030 1031 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; 1032 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 1033 if (pfn_valid(pfn)) { 1034 struct page *page = pfn_to_page(pfn); 1035 1036 if (!swsusp_page_is_forbidden(page)) 1037 swsusp_unset_page_free(page); 1038 } 1039 1040 for_each_migratetype_order(order, t) { 1041 list_for_each(curr, &zone->free_area[order].free_list[t]) { 1042 unsigned long i; 1043 1044 pfn = page_to_pfn(list_entry(curr, struct page, lru)); 1045 for (i = 0; i < (1UL << order); i++) 1046 swsusp_set_page_free(pfn_to_page(pfn + i)); 1047 } 1048 } 1049 spin_unlock_irqrestore(&zone->lock, flags); 1050} 1051#endif /* CONFIG_PM */ 1052 1053/* 1054 * Free a 0-order page 1055 */ 1056static void free_hot_cold_page(struct page *page, int cold) 1057{ 1058 struct zone *zone = page_zone(page); 1059 struct per_cpu_pages *pcp; 1060 unsigned long flags; 1061 int migratetype; 1062 int wasMlocked = __TestClearPageMlocked(page); 1063 1064 kmemcheck_free_shadow(page, 0); 1065 1066 if (PageAnon(page)) 1067 page->mapping = NULL; 1068 if (free_pages_check(page)) 1069 return; 1070 1071 if (!PageHighMem(page)) { 1072 debug_check_no_locks_freed(page_address(page), PAGE_SIZE); 1073 debug_check_no_obj_freed(page_address(page), PAGE_SIZE); 1074 } 1075 arch_free_page(page, 0); 1076 kernel_map_pages(page, 1, 0); 1077 1078 pcp = &zone_pcp(zone, get_cpu())->pcp; 1079 migratetype = get_pageblock_migratetype(page); 1080 set_page_private(page, migratetype); 1081 local_irq_save(flags); 1082 if (unlikely(wasMlocked)) 1083 free_page_mlock(page); 1084 __count_vm_event(PGFREE); 1085 1086 /* 1087 * We only track unmovable, reclaimable and movable on pcp lists. 1088 * Free ISOLATE pages back to the allocator because they are being 1089 * offlined but treat RESERVE as movable pages so we can get those 1090 * areas back if necessary. Otherwise, we may have to free 1091 * excessively into the page allocator 1092 */ 1093 if (migratetype >= MIGRATE_PCPTYPES) { 1094 if (unlikely(migratetype == MIGRATE_ISOLATE)) { 1095 free_one_page(zone, page, 0, migratetype); 1096 goto out; 1097 } 1098 migratetype = MIGRATE_MOVABLE; 1099 } 1100 1101 if (cold) 1102 list_add_tail(&page->lru, &pcp->lists[migratetype]); 1103 else 1104 list_add(&page->lru, &pcp->lists[migratetype]); 1105 pcp->count++; 1106 if (pcp->count >= pcp->high) { 1107 free_pcppages_bulk(zone, pcp->batch, pcp); 1108 pcp->count -= pcp->batch; 1109 } 1110 1111out: 1112 local_irq_restore(flags); 1113 put_cpu(); 1114} 1115 1116void free_hot_page(struct page *page) 1117{ 1118 trace_mm_page_free_direct(page, 0); 1119 free_hot_cold_page(page, 0); 1120} 1121 1122/* 1123 * split_page takes a non-compound higher-order page, and splits it into 1124 * n (1<<order) sub-pages: page[0..n] 1125 * Each sub-page must be freed individually. 1126 * 1127 * Note: this is probably too low level an operation for use in drivers. 1128 * Please consult with lkml before using this in your driver. 1129 */ 1130void split_page(struct page *page, unsigned int order) 1131{ 1132 int i; 1133 1134 VM_BUG_ON(PageCompound(page)); 1135 VM_BUG_ON(!page_count(page)); 1136 1137#ifdef CONFIG_KMEMCHECK 1138 /* 1139 * Split shadow pages too, because free(page[0]) would 1140 * otherwise free the whole shadow. 1141 */ 1142 if (kmemcheck_page_is_tracked(page)) 1143 split_page(virt_to_page(page[0].shadow), order); 1144#endif 1145 1146 for (i = 1; i < (1 << order); i++) 1147 set_page_refcounted(page + i); 1148} 1149 1150/* 1151 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 1152 * we cheat by calling it from here, in the order > 0 path. Saves a branch 1153 * or two. 1154 */ 1155static inline 1156struct page *buffered_rmqueue(struct zone *preferred_zone, 1157 struct zone *zone, int order, gfp_t gfp_flags, 1158 int migratetype) 1159{ 1160 unsigned long flags; 1161 struct page *page; 1162 int cold = !!(gfp_flags & __GFP_COLD); 1163 int cpu; 1164 1165again: 1166 cpu = get_cpu(); 1167 if (likely(order == 0)) { 1168 struct per_cpu_pages *pcp; 1169 struct list_head *list; 1170 1171 pcp = &zone_pcp(zone, cpu)->pcp; 1172 list = &pcp->lists[migratetype]; 1173 local_irq_save(flags); 1174 if (list_empty(list)) { 1175 pcp->count += rmqueue_bulk(zone, 0, 1176 pcp->batch, list, 1177 migratetype, cold); 1178 if (unlikely(list_empty(list))) 1179 goto failed; 1180 } 1181 1182 if (cold) 1183 page = list_entry(list->prev, struct page, lru); 1184 else 1185 page = list_entry(list->next, struct page, lru); 1186 1187 list_del(&page->lru); 1188 pcp->count--; 1189 } else { 1190 if (unlikely(gfp_flags & __GFP_NOFAIL)) { 1191 /* 1192 * __GFP_NOFAIL is not to be used in new code. 1193 * 1194 * All __GFP_NOFAIL callers should be fixed so that they 1195 * properly detect and handle allocation failures. 1196 * 1197 * We most definitely don't want callers attempting to 1198 * allocate greater than order-1 page units with 1199 * __GFP_NOFAIL. 1200 */ 1201 WARN_ON_ONCE(order > 1); 1202 } 1203 spin_lock_irqsave(&zone->lock, flags); 1204 page = __rmqueue(zone, order, migratetype); 1205 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order)); 1206 spin_unlock(&zone->lock); 1207 if (!page) 1208 goto failed; 1209 } 1210 1211 __count_zone_vm_events(PGALLOC, zone, 1 << order); 1212 zone_statistics(preferred_zone, zone); 1213 local_irq_restore(flags); 1214 put_cpu(); 1215 1216 VM_BUG_ON(bad_range(zone, page)); 1217 if (prep_new_page(page, order, gfp_flags)) 1218 goto again; 1219 return page; 1220 1221failed: 1222 local_irq_restore(flags); 1223 put_cpu(); 1224 return NULL; 1225} 1226 1227/* The ALLOC_WMARK bits are used as an index to zone->watermark */ 1228#define ALLOC_WMARK_MIN WMARK_MIN 1229#define ALLOC_WMARK_LOW WMARK_LOW 1230#define ALLOC_WMARK_HIGH WMARK_HIGH 1231#define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 1232 1233/* Mask to get the watermark bits */ 1234#define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 1235 1236#define ALLOC_HARDER 0x10 /* try to alloc harder */ 1237#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 1238#define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 1239 1240#ifdef CONFIG_FAIL_PAGE_ALLOC 1241 1242static struct fail_page_alloc_attr { 1243 struct fault_attr attr; 1244 1245 u32 ignore_gfp_highmem; 1246 u32 ignore_gfp_wait; 1247 u32 min_order; 1248 1249#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1250 1251 struct dentry *ignore_gfp_highmem_file; 1252 struct dentry *ignore_gfp_wait_file; 1253 struct dentry *min_order_file; 1254 1255#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1256 1257} fail_page_alloc = { 1258 .attr = FAULT_ATTR_INITIALIZER, 1259 .ignore_gfp_wait = 1, 1260 .ignore_gfp_highmem = 1, 1261 .min_order = 1, 1262}; 1263 1264static int __init setup_fail_page_alloc(char *str) 1265{ 1266 return setup_fault_attr(&fail_page_alloc.attr, str); 1267} 1268__setup("fail_page_alloc=", setup_fail_page_alloc); 1269 1270static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1271{ 1272 if (order < fail_page_alloc.min_order) 1273 return 0; 1274 if (gfp_mask & __GFP_NOFAIL) 1275 return 0; 1276 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 1277 return 0; 1278 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) 1279 return 0; 1280 1281 return should_fail(&fail_page_alloc.attr, 1 << order); 1282} 1283 1284#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1285 1286static int __init fail_page_alloc_debugfs(void) 1287{ 1288 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; 1289 struct dentry *dir; 1290 int err; 1291 1292 err = init_fault_attr_dentries(&fail_page_alloc.attr, 1293 "fail_page_alloc"); 1294 if (err) 1295 return err; 1296 dir = fail_page_alloc.attr.dentries.dir; 1297 1298 fail_page_alloc.ignore_gfp_wait_file = 1299 debugfs_create_bool("ignore-gfp-wait", mode, dir, 1300 &fail_page_alloc.ignore_gfp_wait); 1301 1302 fail_page_alloc.ignore_gfp_highmem_file = 1303 debugfs_create_bool("ignore-gfp-highmem", mode, dir, 1304 &fail_page_alloc.ignore_gfp_highmem); 1305 fail_page_alloc.min_order_file = 1306 debugfs_create_u32("min-order", mode, dir, 1307 &fail_page_alloc.min_order); 1308 1309 if (!fail_page_alloc.ignore_gfp_wait_file || 1310 !fail_page_alloc.ignore_gfp_highmem_file || 1311 !fail_page_alloc.min_order_file) { 1312 err = -ENOMEM; 1313 debugfs_remove(fail_page_alloc.ignore_gfp_wait_file); 1314 debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file); 1315 debugfs_remove(fail_page_alloc.min_order_file); 1316 cleanup_fault_attr_dentries(&fail_page_alloc.attr); 1317 } 1318 1319 return err; 1320} 1321 1322late_initcall(fail_page_alloc_debugfs); 1323 1324#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1325 1326#else /* CONFIG_FAIL_PAGE_ALLOC */ 1327 1328static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1329{ 1330 return 0; 1331} 1332 1333#endif /* CONFIG_FAIL_PAGE_ALLOC */ 1334 1335/* 1336 * Return 1 if free pages are above 'mark'. This takes into account the order 1337 * of the allocation. 1338 */ 1339int zone_watermark_ok(struct zone *z, int order, unsigned long mark, 1340 int classzone_idx, int alloc_flags) 1341{ 1342 /* free_pages my go negative - that's OK */ 1343 long min = mark; 1344 long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1; 1345 int o; 1346 1347 if (alloc_flags & ALLOC_HIGH) 1348 min -= min / 2; 1349 if (alloc_flags & ALLOC_HARDER) 1350 min -= min / 4; 1351 1352 if (free_pages <= min + z->lowmem_reserve[classzone_idx]) 1353 return 0; 1354 for (o = 0; o < order; o++) { 1355 /* At the next order, this order's pages become unavailable */ 1356 free_pages -= z->free_area[o].nr_free << o; 1357 1358 /* Require fewer higher order pages to be free */ 1359 min >>= 1; 1360 1361 if (free_pages <= min) 1362 return 0; 1363 } 1364 return 1; 1365} 1366 1367#ifdef CONFIG_NUMA 1368/* 1369 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to 1370 * skip over zones that are not allowed by the cpuset, or that have 1371 * been recently (in last second) found to be nearly full. See further 1372 * comments in mmzone.h. Reduces cache footprint of zonelist scans 1373 * that have to skip over a lot of full or unallowed zones. 1374 * 1375 * If the zonelist cache is present in the passed in zonelist, then 1376 * returns a pointer to the allowed node mask (either the current 1377 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].) 1378 * 1379 * If the zonelist cache is not available for this zonelist, does 1380 * nothing and returns NULL. 1381 * 1382 * If the fullzones BITMAP in the zonelist cache is stale (more than 1383 * a second since last zap'd) then we zap it out (clear its bits.) 1384 * 1385 * We hold off even calling zlc_setup, until after we've checked the 1386 * first zone in the zonelist, on the theory that most allocations will 1387 * be satisfied from that first zone, so best to examine that zone as 1388 * quickly as we can. 1389 */ 1390static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1391{ 1392 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1393 nodemask_t *allowednodes; /* zonelist_cache approximation */ 1394 1395 zlc = zonelist->zlcache_ptr; 1396 if (!zlc) 1397 return NULL; 1398 1399 if (time_after(jiffies, zlc->last_full_zap + HZ)) { 1400 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1401 zlc->last_full_zap = jiffies; 1402 } 1403 1404 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? 1405 &cpuset_current_mems_allowed : 1406 &node_states[N_HIGH_MEMORY]; 1407 return allowednodes; 1408} 1409 1410/* 1411 * Given 'z' scanning a zonelist, run a couple of quick checks to see 1412 * if it is worth looking at further for free memory: 1413 * 1) Check that the zone isn't thought to be full (doesn't have its 1414 * bit set in the zonelist_cache fullzones BITMAP). 1415 * 2) Check that the zones node (obtained from the zonelist_cache 1416 * z_to_n[] mapping) is allowed in the passed in allowednodes mask. 1417 * Return true (non-zero) if zone is worth looking at further, or 1418 * else return false (zero) if it is not. 1419 * 1420 * This check -ignores- the distinction between various watermarks, 1421 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is 1422 * found to be full for any variation of these watermarks, it will 1423 * be considered full for up to one second by all requests, unless 1424 * we are so low on memory on all allowed nodes that we are forced 1425 * into the second scan of the zonelist. 1426 * 1427 * In the second scan we ignore this zonelist cache and exactly 1428 * apply the watermarks to all zones, even it is slower to do so. 1429 * We are low on memory in the second scan, and should leave no stone 1430 * unturned looking for a free page. 1431 */ 1432static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1433 nodemask_t *allowednodes) 1434{ 1435 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1436 int i; /* index of *z in zonelist zones */ 1437 int n; /* node that zone *z is on */ 1438 1439 zlc = zonelist->zlcache_ptr; 1440 if (!zlc) 1441 return 1; 1442 1443 i = z - zonelist->_zonerefs; 1444 n = zlc->z_to_n[i]; 1445 1446 /* This zone is worth trying if it is allowed but not full */ 1447 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); 1448} 1449 1450/* 1451 * Given 'z' scanning a zonelist, set the corresponding bit in 1452 * zlc->fullzones, so that subsequent attempts to allocate a page 1453 * from that zone don't waste time re-examining it. 1454 */ 1455static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1456{ 1457 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1458 int i; /* index of *z in zonelist zones */ 1459 1460 zlc = zonelist->zlcache_ptr; 1461 if (!zlc) 1462 return; 1463 1464 i = z - zonelist->_zonerefs; 1465 1466 set_bit(i, zlc->fullzones); 1467} 1468 1469#else /* CONFIG_NUMA */ 1470 1471static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1472{ 1473 return NULL; 1474} 1475 1476static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1477 nodemask_t *allowednodes) 1478{ 1479 return 1; 1480} 1481 1482static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1483{ 1484} 1485#endif /* CONFIG_NUMA */ 1486 1487/* 1488 * get_page_from_freelist goes through the zonelist trying to allocate 1489 * a page. 1490 */ 1491static struct page * 1492get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order, 1493 struct zonelist *zonelist, int high_zoneidx, int alloc_flags, 1494 struct zone *preferred_zone, int migratetype) 1495{ 1496 struct zoneref *z; 1497 struct page *page = NULL; 1498 int classzone_idx; 1499 struct zone *zone; 1500 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ 1501 int zlc_active = 0; /* set if using zonelist_cache */ 1502 int did_zlc_setup = 0; /* just call zlc_setup() one time */ 1503 1504 classzone_idx = zone_idx(preferred_zone); 1505zonelist_scan: 1506 /* 1507 * Scan zonelist, looking for a zone with enough free. 1508 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1509 */ 1510 for_each_zone_zonelist_nodemask(zone, z, zonelist, 1511 high_zoneidx, nodemask) { 1512 if (NUMA_BUILD && zlc_active && 1513 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 1514 continue; 1515 if ((alloc_flags & ALLOC_CPUSET) && 1516 !cpuset_zone_allowed_softwall(zone, gfp_mask)) 1517 goto try_next_zone; 1518 1519 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK); 1520 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { 1521 unsigned long mark; 1522 int ret; 1523 1524 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK]; 1525 if (zone_watermark_ok(zone, order, mark, 1526 classzone_idx, alloc_flags)) 1527 goto try_this_zone; 1528 1529 if (zone_reclaim_mode == 0) 1530 goto this_zone_full; 1531 1532 ret = zone_reclaim(zone, gfp_mask, order); 1533 switch (ret) { 1534 case ZONE_RECLAIM_NOSCAN: 1535 /* did not scan */ 1536 goto try_next_zone; 1537 case ZONE_RECLAIM_FULL: 1538 /* scanned but unreclaimable */ 1539 goto this_zone_full; 1540 default: 1541 /* did we reclaim enough */ 1542 if (!zone_watermark_ok(zone, order, mark, 1543 classzone_idx, alloc_flags)) 1544 goto this_zone_full; 1545 } 1546 } 1547 1548try_this_zone: 1549 page = buffered_rmqueue(preferred_zone, zone, order, 1550 gfp_mask, migratetype); 1551 if (page) 1552 break; 1553this_zone_full: 1554 if (NUMA_BUILD) 1555 zlc_mark_zone_full(zonelist, z); 1556try_next_zone: 1557 if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) { 1558 /* 1559 * we do zlc_setup after the first zone is tried but only 1560 * if there are multiple nodes make it worthwhile 1561 */ 1562 allowednodes = zlc_setup(zonelist, alloc_flags); 1563 zlc_active = 1; 1564 did_zlc_setup = 1; 1565 } 1566 } 1567 1568 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) { 1569 /* Disable zlc cache for second zonelist scan */ 1570 zlc_active = 0; 1571 goto zonelist_scan; 1572 } 1573 return page; 1574} 1575 1576static inline int 1577should_alloc_retry(gfp_t gfp_mask, unsigned int order, 1578 unsigned long pages_reclaimed) 1579{ 1580 /* Do not loop if specifically requested */ 1581 if (gfp_mask & __GFP_NORETRY) 1582 return 0; 1583 1584 /* 1585 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER 1586 * means __GFP_NOFAIL, but that may not be true in other 1587 * implementations. 1588 */ 1589 if (order <= PAGE_ALLOC_COSTLY_ORDER) 1590 return 1; 1591 1592 /* 1593 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is 1594 * specified, then we retry until we no longer reclaim any pages 1595 * (above), or we've reclaimed an order of pages at least as 1596 * large as the allocation's order. In both cases, if the 1597 * allocation still fails, we stop retrying. 1598 */ 1599 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order)) 1600 return 1; 1601 1602 /* 1603 * Don't let big-order allocations loop unless the caller 1604 * explicitly requests that. 1605 */ 1606 if (gfp_mask & __GFP_NOFAIL) 1607 return 1; 1608 1609 return 0; 1610} 1611 1612static inline struct page * 1613__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, 1614 struct zonelist *zonelist, enum zone_type high_zoneidx, 1615 nodemask_t *nodemask, struct zone *preferred_zone, 1616 int migratetype) 1617{ 1618 struct page *page; 1619 1620 /* Acquire the OOM killer lock for the zones in zonelist */ 1621 if (!try_set_zone_oom(zonelist, gfp_mask)) { 1622 schedule_timeout_uninterruptible(1); 1623 return NULL; 1624 } 1625 1626 /* 1627 * Go through the zonelist yet one more time, keep very high watermark 1628 * here, this is only to catch a parallel oom killing, we must fail if 1629 * we're still under heavy pressure. 1630 */ 1631 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, 1632 order, zonelist, high_zoneidx, 1633 ALLOC_WMARK_HIGH|ALLOC_CPUSET, 1634 preferred_zone, migratetype); 1635 if (page) 1636 goto out; 1637 1638 /* The OOM killer will not help higher order allocs */ 1639 if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_NOFAIL)) 1640 goto out; 1641 1642 /* Exhausted what can be done so it's blamo time */ 1643 out_of_memory(zonelist, gfp_mask, order); 1644 1645out: 1646 clear_zonelist_oom(zonelist, gfp_mask); 1647 return page; 1648} 1649 1650/* The really slow allocator path where we enter direct reclaim */ 1651static inline struct page * 1652__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order, 1653 struct zonelist *zonelist, enum zone_type high_zoneidx, 1654 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, 1655 int migratetype, unsigned long *did_some_progress) 1656{ 1657 struct page *page = NULL; 1658 struct reclaim_state reclaim_state; 1659 struct task_struct *p = current; 1660 1661 cond_resched(); 1662 1663 /* We now go into synchronous reclaim */ 1664 cpuset_memory_pressure_bump(); 1665 p->flags |= PF_MEMALLOC; 1666 lockdep_set_current_reclaim_state(gfp_mask); 1667 reclaim_state.reclaimed_slab = 0; 1668 p->reclaim_state = &reclaim_state; 1669 1670 *did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask); 1671 1672 p->reclaim_state = NULL; 1673 lockdep_clear_current_reclaim_state(); 1674 p->flags &= ~PF_MEMALLOC; 1675 1676 cond_resched(); 1677 1678 if (order != 0) 1679 drain_all_pages(); 1680 1681 if (likely(*did_some_progress)) 1682 page = get_page_from_freelist(gfp_mask, nodemask, order, 1683 zonelist, high_zoneidx, 1684 alloc_flags, preferred_zone, 1685 migratetype); 1686 return page; 1687} 1688 1689/* 1690 * This is called in the allocator slow-path if the allocation request is of 1691 * sufficient urgency to ignore watermarks and take other desperate measures 1692 */ 1693static inline struct page * 1694__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order, 1695 struct zonelist *zonelist, enum zone_type high_zoneidx, 1696 nodemask_t *nodemask, struct zone *preferred_zone, 1697 int migratetype) 1698{ 1699 struct page *page; 1700 1701 do { 1702 page = get_page_from_freelist(gfp_mask, nodemask, order, 1703 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS, 1704 preferred_zone, migratetype); 1705 1706 if (!page && gfp_mask & __GFP_NOFAIL) 1707 congestion_wait(BLK_RW_ASYNC, HZ/50); 1708 } while (!page && (gfp_mask & __GFP_NOFAIL)); 1709 1710 return page; 1711} 1712 1713static inline 1714void wake_all_kswapd(unsigned int order, struct zonelist *zonelist, 1715 enum zone_type high_zoneidx) 1716{ 1717 struct zoneref *z; 1718 struct zone *zone; 1719 1720 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) 1721 wakeup_kswapd(zone, order); 1722} 1723 1724static inline int 1725gfp_to_alloc_flags(gfp_t gfp_mask) 1726{ 1727 struct task_struct *p = current; 1728 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; 1729 const gfp_t wait = gfp_mask & __GFP_WAIT; 1730 1731 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */ 1732 BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH); 1733 1734 /* 1735 * The caller may dip into page reserves a bit more if the caller 1736 * cannot run direct reclaim, or if the caller has realtime scheduling 1737 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will 1738 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). 1739 */ 1740 alloc_flags |= (gfp_mask & __GFP_HIGH); 1741 1742 if (!wait) { 1743 alloc_flags |= ALLOC_HARDER; 1744 /* 1745 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. 1746 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1747 */ 1748 alloc_flags &= ~ALLOC_CPUSET; 1749 } else if (unlikely(rt_task(p))) 1750 alloc_flags |= ALLOC_HARDER; 1751 1752 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) { 1753 if (!in_interrupt() && 1754 ((p->flags & PF_MEMALLOC) || 1755 unlikely(test_thread_flag(TIF_MEMDIE)))) 1756 alloc_flags |= ALLOC_NO_WATERMARKS; 1757 } 1758 1759 return alloc_flags; 1760} 1761 1762static inline struct page * 1763__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, 1764 struct zonelist *zonelist, enum zone_type high_zoneidx, 1765 nodemask_t *nodemask, struct zone *preferred_zone, 1766 int migratetype) 1767{ 1768 const gfp_t wait = gfp_mask & __GFP_WAIT; 1769 struct page *page = NULL; 1770 int alloc_flags; 1771 unsigned long pages_reclaimed = 0; 1772 unsigned long did_some_progress; 1773 struct task_struct *p = current; 1774 1775 /* 1776 * In the slowpath, we sanity check order to avoid ever trying to 1777 * reclaim >= MAX_ORDER areas which will never succeed. Callers may 1778 * be using allocators in order of preference for an area that is 1779 * too large. 1780 */ 1781 if (order >= MAX_ORDER) { 1782 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN)); 1783 return NULL; 1784 } 1785 1786 /* 1787 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and 1788 * __GFP_NOWARN set) should not cause reclaim since the subsystem 1789 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim 1790 * using a larger set of nodes after it has established that the 1791 * allowed per node queues are empty and that nodes are 1792 * over allocated. 1793 */ 1794 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) 1795 goto nopage; 1796 1797 wake_all_kswapd(order, zonelist, high_zoneidx); 1798 1799restart: 1800 /* 1801 * OK, we're below the kswapd watermark and have kicked background 1802 * reclaim. Now things get more complex, so set up alloc_flags according 1803 * to how we want to proceed. 1804 */ 1805 alloc_flags = gfp_to_alloc_flags(gfp_mask); 1806 1807 /* This is the last chance, in general, before the goto nopage. */ 1808 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, 1809 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS, 1810 preferred_zone, migratetype); 1811 if (page) 1812 goto got_pg; 1813 1814rebalance: 1815 /* Allocate without watermarks if the context allows */ 1816 if (alloc_flags & ALLOC_NO_WATERMARKS) { 1817 page = __alloc_pages_high_priority(gfp_mask, order, 1818 zonelist, high_zoneidx, nodemask, 1819 preferred_zone, migratetype); 1820 if (page) 1821 goto got_pg; 1822 } 1823 1824 /* Atomic allocations - we can't balance anything */ 1825 if (!wait) 1826 goto nopage; 1827 1828 /* Avoid recursion of direct reclaim */ 1829 if (p->flags & PF_MEMALLOC) 1830 goto nopage; 1831 1832 /* Avoid allocations with no watermarks from looping endlessly */ 1833 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL)) 1834 goto nopage; 1835 1836 /* Try direct reclaim and then allocating */ 1837 page = __alloc_pages_direct_reclaim(gfp_mask, order, 1838 zonelist, high_zoneidx, 1839 nodemask, 1840 alloc_flags, preferred_zone, 1841 migratetype, &did_some_progress); 1842 if (page) 1843 goto got_pg; 1844 1845 /* 1846 * If we failed to make any progress reclaiming, then we are 1847 * running out of options and have to consider going OOM 1848 */ 1849 if (!did_some_progress) { 1850 if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { 1851 if (oom_killer_disabled) 1852 goto nopage; 1853 page = __alloc_pages_may_oom(gfp_mask, order, 1854 zonelist, high_zoneidx, 1855 nodemask, preferred_zone, 1856 migratetype); 1857 if (page) 1858 goto got_pg; 1859 1860 /* 1861 * The OOM killer does not trigger for high-order 1862 * ~__GFP_NOFAIL allocations so if no progress is being 1863 * made, there are no other options and retrying is 1864 * unlikely to help. 1865 */ 1866 if (order > PAGE_ALLOC_COSTLY_ORDER && 1867 !(gfp_mask & __GFP_NOFAIL)) 1868 goto nopage; 1869 1870 goto restart; 1871 } 1872 } 1873 1874 /* Check if we should retry the allocation */ 1875 pages_reclaimed += did_some_progress; 1876 if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) { 1877 /* Wait for some write requests to complete then retry */ 1878 congestion_wait(BLK_RW_ASYNC, HZ/50); 1879 goto rebalance; 1880 } 1881 1882nopage: 1883 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { 1884 printk(KERN_WARNING "%s: page allocation failure." 1885 " order:%d, mode:0x%x\n", 1886 p->comm, order, gfp_mask); 1887 dump_stack(); 1888 show_mem(); 1889 } 1890 return page; 1891got_pg: 1892 if (kmemcheck_enabled) 1893 kmemcheck_pagealloc_alloc(page, order, gfp_mask); 1894 return page; 1895 1896} 1897 1898/* 1899 * This is the 'heart' of the zoned buddy allocator. 1900 */ 1901struct page * 1902__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, 1903 struct zonelist *zonelist, nodemask_t *nodemask) 1904{ 1905 enum zone_type high_zoneidx = gfp_zone(gfp_mask); 1906 struct zone *preferred_zone; 1907 struct page *page; 1908 int migratetype = allocflags_to_migratetype(gfp_mask); 1909 1910 gfp_mask &= gfp_allowed_mask; 1911 1912 lockdep_trace_alloc(gfp_mask); 1913 1914 might_sleep_if(gfp_mask & __GFP_WAIT); 1915 1916 if (should_fail_alloc_page(gfp_mask, order)) 1917 return NULL; 1918 1919 /* 1920 * Check the zones suitable for the gfp_mask contain at least one 1921 * valid zone. It's possible to have an empty zonelist as a result 1922 * of GFP_THISNODE and a memoryless node 1923 */ 1924 if (unlikely(!zonelist->_zonerefs->zone)) 1925 return NULL; 1926 1927 /* The preferred zone is used for statistics later */ 1928 first_zones_zonelist(zonelist, high_zoneidx, nodemask, &preferred_zone); 1929 if (!preferred_zone) 1930 return NULL; 1931 1932 /* First allocation attempt */ 1933 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order, 1934 zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET, 1935 preferred_zone, migratetype); 1936 if (unlikely(!page)) 1937 page = __alloc_pages_slowpath(gfp_mask, order, 1938 zonelist, high_zoneidx, nodemask, 1939 preferred_zone, migratetype); 1940 1941 trace_mm_page_alloc(page, order, gfp_mask, migratetype); 1942 return page; 1943} 1944EXPORT_SYMBOL(__alloc_pages_nodemask); 1945 1946/* 1947 * Common helper functions. 1948 */ 1949unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 1950{ 1951 struct page *page; 1952 1953 /* 1954 * __get_free_pages() returns a 32-bit address, which cannot represent 1955 * a highmem page 1956 */ 1957 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 1958 1959 page = alloc_pages(gfp_mask, order); 1960 if (!page) 1961 return 0; 1962 return (unsigned long) page_address(page); 1963} 1964EXPORT_SYMBOL(__get_free_pages); 1965 1966unsigned long get_zeroed_page(gfp_t gfp_mask) 1967{ 1968 return __get_free_pages(gfp_mask | __GFP_ZERO, 0); 1969} 1970EXPORT_SYMBOL(get_zeroed_page); 1971 1972void __pagevec_free(struct pagevec *pvec) 1973{ 1974 int i = pagevec_count(pvec); 1975 1976 while (--i >= 0) { 1977 trace_mm_pagevec_free(pvec->pages[i], pvec->cold); 1978 free_hot_cold_page(pvec->pages[i], pvec->cold); 1979 } 1980} 1981 1982void __free_pages(struct page *page, unsigned int order) 1983{ 1984 if (put_page_testzero(page)) { 1985 trace_mm_page_free_direct(page, order); 1986 if (order == 0) 1987 free_hot_page(page); 1988 else 1989 __free_pages_ok(page, order); 1990 } 1991} 1992 1993EXPORT_SYMBOL(__free_pages); 1994 1995void free_pages(unsigned long addr, unsigned int order) 1996{ 1997 if (addr != 0) { 1998 VM_BUG_ON(!virt_addr_valid((void *)addr)); 1999 __free_pages(virt_to_page((void *)addr), order); 2000 } 2001} 2002 2003EXPORT_SYMBOL(free_pages); 2004 2005/** 2006 * alloc_pages_exact - allocate an exact number physically-contiguous pages. 2007 * @size: the number of bytes to allocate 2008 * @gfp_mask: GFP flags for the allocation 2009 * 2010 * This function is similar to alloc_pages(), except that it allocates the 2011 * minimum number of pages to satisfy the request. alloc_pages() can only 2012 * allocate memory in power-of-two pages. 2013 * 2014 * This function is also limited by MAX_ORDER. 2015 * 2016 * Memory allocated by this function must be released by free_pages_exact(). 2017 */ 2018void *alloc_pages_exact(size_t size, gfp_t gfp_mask) 2019{ 2020 unsigned int order = get_order(size); 2021 unsigned long addr; 2022 2023 addr = __get_free_pages(gfp_mask, order); 2024 if (addr) { 2025 unsigned long alloc_end = addr + (PAGE_SIZE << order); 2026 unsigned long used = addr + PAGE_ALIGN(size); 2027 2028 split_page(virt_to_page((void *)addr), order); 2029 while (used < alloc_end) { 2030 free_page(used); 2031 used += PAGE_SIZE; 2032 } 2033 } 2034 2035 return (void *)addr; 2036} 2037EXPORT_SYMBOL(alloc_pages_exact); 2038 2039/** 2040 * free_pages_exact - release memory allocated via alloc_pages_exact() 2041 * @virt: the value returned by alloc_pages_exact. 2042 * @size: size of allocation, same value as passed to alloc_pages_exact(). 2043 * 2044 * Release the memory allocated by a previous call to alloc_pages_exact. 2045 */ 2046void free_pages_exact(void *virt, size_t size) 2047{ 2048 unsigned long addr = (unsigned long)virt; 2049 unsigned long end = addr + PAGE_ALIGN(size); 2050 2051 while (addr < end) { 2052 free_page(addr); 2053 addr += PAGE_SIZE; 2054 } 2055} 2056EXPORT_SYMBOL(free_pages_exact); 2057 2058static unsigned int nr_free_zone_pages(int offset) 2059{ 2060 struct zoneref *z; 2061 struct zone *zone; 2062 2063 /* Just pick one node, since fallback list is circular */ 2064 unsigned int sum = 0; 2065 2066 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); 2067 2068 for_each_zone_zonelist(zone, z, zonelist, offset) { 2069 unsigned long size = zone->present_pages; 2070 unsigned long high = high_wmark_pages(zone); 2071 if (size > high) 2072 sum += size - high; 2073 } 2074 2075 return sum; 2076} 2077 2078/* 2079 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL 2080 */ 2081unsigned int nr_free_buffer_pages(void) 2082{ 2083 return nr_free_zone_pages(gfp_zone(GFP_USER)); 2084} 2085EXPORT_SYMBOL_GPL(nr_free_buffer_pages); 2086 2087/* 2088 * Amount of free RAM allocatable within all zones 2089 */ 2090unsigned int nr_free_pagecache_pages(void) 2091{ 2092 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); 2093} 2094 2095static inline void show_node(struct zone *zone) 2096{ 2097 if (NUMA_BUILD) 2098 printk("Node %d ", zone_to_nid(zone)); 2099} 2100 2101void si_meminfo(struct sysinfo *val) 2102{ 2103 val->totalram = totalram_pages; 2104 val->sharedram = 0; 2105 val->freeram = global_page_state(NR_FREE_PAGES); 2106 val->bufferram = nr_blockdev_pages(); 2107 val->totalhigh = totalhigh_pages; 2108 val->freehigh = nr_free_highpages(); 2109 val->mem_unit = PAGE_SIZE; 2110} 2111 2112EXPORT_SYMBOL(si_meminfo); 2113 2114#ifdef CONFIG_NUMA 2115void si_meminfo_node(struct sysinfo *val, int nid) 2116{ 2117 pg_data_t *pgdat = NODE_DATA(nid); 2118 2119 val->totalram = pgdat->node_present_pages; 2120 val->freeram = node_page_state(nid, NR_FREE_PAGES); 2121#ifdef CONFIG_HIGHMEM 2122 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; 2123 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], 2124 NR_FREE_PAGES); 2125#else 2126 val->totalhigh = 0; 2127 val->freehigh = 0; 2128#endif 2129 val->mem_unit = PAGE_SIZE; 2130} 2131#endif 2132 2133#define K(x) ((x) << (PAGE_SHIFT-10)) 2134 2135/* 2136 * Show free area list (used inside shift_scroll-lock stuff) 2137 * We also calculate the percentage fragmentation. We do this by counting the 2138 * memory on each free list with the exception of the first item on the list. 2139 */ 2140void show_free_areas(void) 2141{ 2142 int cpu; 2143 struct zone *zone; 2144 2145 for_each_populated_zone(zone) { 2146 show_node(zone); 2147 printk("%s per-cpu:\n", zone->name); 2148 2149 for_each_online_cpu(cpu) { 2150 struct per_cpu_pageset *pageset; 2151 2152 pageset = zone_pcp(zone, cpu); 2153 2154 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n", 2155 cpu, pageset->pcp.high, 2156 pageset->pcp.batch, pageset->pcp.count); 2157 } 2158 } 2159 2160 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n" 2161 " active_file:%lu inactive_file:%lu isolated_file:%lu\n" 2162 " unevictable:%lu" 2163 " dirty:%lu writeback:%lu unstable:%lu buffer:%lu\n" 2164 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n" 2165 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n", 2166 global_page_state(NR_ACTIVE_ANON), 2167 global_page_state(NR_INACTIVE_ANON), 2168 global_page_state(NR_ISOLATED_ANON), 2169 global_page_state(NR_ACTIVE_FILE), 2170 global_page_state(NR_INACTIVE_FILE), 2171 global_page_state(NR_ISOLATED_FILE), 2172 global_page_state(NR_UNEVICTABLE), 2173 global_page_state(NR_FILE_DIRTY), 2174 global_page_state(NR_WRITEBACK), 2175 global_page_state(NR_UNSTABLE_NFS), 2176 nr_blockdev_pages(), 2177 global_page_state(NR_FREE_PAGES), 2178 global_page_state(NR_SLAB_RECLAIMABLE), 2179 global_page_state(NR_SLAB_UNRECLAIMABLE), 2180 global_page_state(NR_FILE_MAPPED), 2181 global_page_state(NR_SHMEM), 2182 global_page_state(NR_PAGETABLE), 2183 global_page_state(NR_BOUNCE)); 2184 2185 for_each_populated_zone(zone) { 2186 int i; 2187 2188 show_node(zone); 2189 printk("%s" 2190 " free:%lukB" 2191 " min:%lukB" 2192 " low:%lukB" 2193 " high:%lukB" 2194 " active_anon:%lukB" 2195 " inactive_anon:%lukB" 2196 " active_file:%lukB" 2197 " inactive_file:%lukB" 2198 " unevictable:%lukB" 2199 " isolated(anon):%lukB" 2200 " isolated(file):%lukB" 2201 " present:%lukB" 2202 " mlocked:%lukB" 2203 " dirty:%lukB" 2204 " writeback:%lukB" 2205 " mapped:%lukB" 2206 " shmem:%lukB" 2207 " slab_reclaimable:%lukB" 2208 " slab_unreclaimable:%lukB" 2209 " kernel_stack:%lukB" 2210 " pagetables:%lukB" 2211 " unstable:%lukB" 2212 " bounce:%lukB" 2213 " writeback_tmp:%lukB" 2214 " pages_scanned:%lu" 2215 " all_unreclaimable? %s" 2216 "\n", 2217 zone->name, 2218 K(zone_page_state(zone, NR_FREE_PAGES)), 2219 K(min_wmark_pages(zone)), 2220 K(low_wmark_pages(zone)), 2221 K(high_wmark_pages(zone)), 2222 K(zone_page_state(zone, NR_ACTIVE_ANON)), 2223 K(zone_page_state(zone, NR_INACTIVE_ANON)), 2224 K(zone_page_state(zone, NR_ACTIVE_FILE)), 2225 K(zone_page_state(zone, NR_INACTIVE_FILE)), 2226 K(zone_page_state(zone, NR_UNEVICTABLE)), 2227 K(zone_page_state(zone, NR_ISOLATED_ANON)), 2228 K(zone_page_state(zone, NR_ISOLATED_FILE)), 2229 K(zone->present_pages), 2230 K(zone_page_state(zone, NR_MLOCK)), 2231 K(zone_page_state(zone, NR_FILE_DIRTY)), 2232 K(zone_page_state(zone, NR_WRITEBACK)), 2233 K(zone_page_state(zone, NR_FILE_MAPPED)), 2234 K(zone_page_state(zone, NR_SHMEM)), 2235 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)), 2236 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)), 2237 zone_page_state(zone, NR_KERNEL_STACK) * 2238 THREAD_SIZE / 1024, 2239 K(zone_page_state(zone, NR_PAGETABLE)), 2240 K(zone_page_state(zone, NR_UNSTABLE_NFS)), 2241 K(zone_page_state(zone, NR_BOUNCE)), 2242 K(zone_page_state(zone, NR_WRITEBACK_TEMP)), 2243 zone->pages_scanned, 2244 (zone_is_all_unreclaimable(zone) ? "yes" : "no") 2245 ); 2246 printk("lowmem_reserve[]:"); 2247 for (i = 0; i < MAX_NR_ZONES; i++) 2248 printk(" %lu", zone->lowmem_reserve[i]); 2249 printk("\n"); 2250 } 2251 2252 for_each_populated_zone(zone) { 2253 unsigned long nr[MAX_ORDER], flags, order, total = 0; 2254 2255 show_node(zone); 2256 printk("%s: ", zone->name); 2257 2258 spin_lock_irqsave(&zone->lock, flags); 2259 for (order = 0; order < MAX_ORDER; order++) { 2260 nr[order] = zone->free_area[order].nr_free; 2261 total += nr[order] << order; 2262 } 2263 spin_unlock_irqrestore(&zone->lock, flags); 2264 for (order = 0; order < MAX_ORDER; order++) 2265 printk("%lu*%lukB ", nr[order], K(1UL) << order); 2266 printk("= %lukB\n", K(total)); 2267 } 2268 2269 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES)); 2270 2271 show_swap_cache_info(); 2272} 2273 2274static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) 2275{ 2276 zoneref->zone = zone; 2277 zoneref->zone_idx = zone_idx(zone); 2278} 2279 2280/* 2281 * Builds allocation fallback zone lists. 2282 * 2283 * Add all populated zones of a node to the zonelist. 2284 */ 2285static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, 2286 int nr_zones, enum zone_type zone_type) 2287{ 2288 struct zone *zone; 2289 2290 BUG_ON(zone_type >= MAX_NR_ZONES); 2291 zone_type++; 2292 2293 do { 2294 zone_type--; 2295 zone = pgdat->node_zones + zone_type; 2296 if (populated_zone(zone)) { 2297 zoneref_set_zone(zone, 2298 &zonelist->_zonerefs[nr_zones++]); 2299 check_highest_zone(zone_type); 2300 } 2301 2302 } while (zone_type); 2303 return nr_zones; 2304} 2305 2306 2307/* 2308 * zonelist_order: 2309 * 0 = automatic detection of better ordering. 2310 * 1 = order by ([node] distance, -zonetype) 2311 * 2 = order by (-zonetype, [node] distance) 2312 * 2313 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create 2314 * the same zonelist. So only NUMA can configure this param. 2315 */ 2316#define ZONELIST_ORDER_DEFAULT 0 2317#define ZONELIST_ORDER_NODE 1 2318#define ZONELIST_ORDER_ZONE 2 2319 2320/* zonelist order in the kernel. 2321 * set_zonelist_order() will set this to NODE or ZONE. 2322 */ 2323static int current_zonelist_order = ZONELIST_ORDER_DEFAULT; 2324static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"}; 2325 2326 2327#ifdef CONFIG_NUMA 2328/* The value user specified ....changed by config */ 2329static int user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2330/* string for sysctl */ 2331#define NUMA_ZONELIST_ORDER_LEN 16 2332char numa_zonelist_order[16] = "default"; 2333 2334/* 2335 * interface for configure zonelist ordering. 2336 * command line option "numa_zonelist_order" 2337 * = "[dD]efault - default, automatic configuration. 2338 * = "[nN]ode - order by node locality, then by zone within node 2339 * = "[zZ]one - order by zone, then by locality within zone 2340 */ 2341 2342static int __parse_numa_zonelist_order(char *s) 2343{ 2344 if (*s == 'd' || *s == 'D') { 2345 user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2346 } else if (*s == 'n' || *s == 'N') { 2347 user_zonelist_order = ZONELIST_ORDER_NODE; 2348 } else if (*s == 'z' || *s == 'Z') { 2349 user_zonelist_order = ZONELIST_ORDER_ZONE; 2350 } else { 2351 printk(KERN_WARNING 2352 "Ignoring invalid numa_zonelist_order value: " 2353 "%s\n", s); 2354 return -EINVAL; 2355 } 2356 return 0; 2357} 2358 2359static __init int setup_numa_zonelist_order(char *s) 2360{ 2361 if (s) 2362 return __parse_numa_zonelist_order(s); 2363 return 0; 2364} 2365early_param("numa_zonelist_order", setup_numa_zonelist_order); 2366 2367/* 2368 * sysctl handler for numa_zonelist_order 2369 */ 2370int numa_zonelist_order_handler(ctl_table *table, int write, 2371 struct file *file, void __user *buffer, size_t *length, 2372 loff_t *ppos) 2373{ 2374 char saved_string[NUMA_ZONELIST_ORDER_LEN]; 2375 int ret; 2376 2377 if (write) 2378 strncpy(saved_string, (char*)table->data, 2379 NUMA_ZONELIST_ORDER_LEN); 2380 ret = proc_dostring(table, write, file, buffer, length, ppos); 2381 if (ret) 2382 return ret; 2383 if (write) { 2384 int oldval = user_zonelist_order; 2385 if (__parse_numa_zonelist_order((char*)table->data)) { 2386 /* 2387 * bogus value. restore saved string 2388 */ 2389 strncpy((char*)table->data, saved_string, 2390 NUMA_ZONELIST_ORDER_LEN); 2391 user_zonelist_order = oldval; 2392 } else if (oldval != user_zonelist_order) 2393 build_all_zonelists(); 2394 } 2395 return 0; 2396} 2397 2398 2399#define MAX_NODE_LOAD (nr_online_nodes) 2400static int node_load[MAX_NUMNODES]; 2401 2402/** 2403 * find_next_best_node - find the next node that should appear in a given node's fallback list 2404 * @node: node whose fallback list we're appending 2405 * @used_node_mask: nodemask_t of already used nodes 2406 * 2407 * We use a number of factors to determine which is the next node that should 2408 * appear on a given node's fallback list. The node should not have appeared 2409 * already in @node's fallback list, and it should be the next closest node 2410 * according to the distance array (which contains arbitrary distance values 2411 * from each node to each node in the system), and should also prefer nodes 2412 * with no CPUs, since presumably they'll have very little allocation pressure 2413 * on them otherwise. 2414 * It returns -1 if no node is found. 2415 */ 2416static int find_next_best_node(int node, nodemask_t *used_node_mask) 2417{ 2418 int n, val; 2419 int min_val = INT_MAX; 2420 int best_node = -1; 2421 const struct cpumask *tmp = cpumask_of_node(0); 2422 2423 /* Use the local node if we haven't already */ 2424 if (!node_isset(node, *used_node_mask)) { 2425 node_set(node, *used_node_mask); 2426 return node; 2427 } 2428 2429 for_each_node_state(n, N_HIGH_MEMORY) { 2430 2431 /* Don't want a node to appear more than once */ 2432 if (node_isset(n, *used_node_mask)) 2433 continue; 2434 2435 /* Use the distance array to find the distance */ 2436 val = node_distance(node, n); 2437 2438 /* Penalize nodes under us ("prefer the next node") */ 2439 val += (n < node); 2440 2441 /* Give preference to headless and unused nodes */ 2442 tmp = cpumask_of_node(n); 2443 if (!cpumask_empty(tmp)) 2444 val += PENALTY_FOR_NODE_WITH_CPUS; 2445 2446 /* Slight preference for less loaded node */ 2447 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 2448 val += node_load[n]; 2449 2450 if (val < min_val) { 2451 min_val = val; 2452 best_node = n; 2453 } 2454 } 2455 2456 if (best_node >= 0) 2457 node_set(best_node, *used_node_mask); 2458 2459 return best_node; 2460} 2461 2462 2463/* 2464 * Build zonelists ordered by node and zones within node. 2465 * This results in maximum locality--normal zone overflows into local 2466 * DMA zone, if any--but risks exhausting DMA zone. 2467 */ 2468static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) 2469{ 2470 int j; 2471 struct zonelist *zonelist; 2472 2473 zonelist = &pgdat->node_zonelists[0]; 2474 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++) 2475 ; 2476 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2477 MAX_NR_ZONES - 1); 2478 zonelist->_zonerefs[j].zone = NULL; 2479 zonelist->_zonerefs[j].zone_idx = 0; 2480} 2481 2482/* 2483 * Build gfp_thisnode zonelists 2484 */ 2485static void build_thisnode_zonelists(pg_data_t *pgdat) 2486{ 2487 int j; 2488 struct zonelist *zonelist; 2489 2490 zonelist = &pgdat->node_zonelists[1]; 2491 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2492 zonelist->_zonerefs[j].zone = NULL; 2493 zonelist->_zonerefs[j].zone_idx = 0; 2494} 2495 2496/* 2497 * Build zonelists ordered by zone and nodes within zones. 2498 * This results in conserving DMA zone[s] until all Normal memory is 2499 * exhausted, but results in overflowing to remote node while memory 2500 * may still exist in local DMA zone. 2501 */ 2502static int node_order[MAX_NUMNODES]; 2503 2504static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) 2505{ 2506 int pos, j, node; 2507 int zone_type; /* needs to be signed */ 2508 struct zone *z; 2509 struct zonelist *zonelist; 2510 2511 zonelist = &pgdat->node_zonelists[0]; 2512 pos = 0; 2513 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) { 2514 for (j = 0; j < nr_nodes; j++) { 2515 node = node_order[j]; 2516 z = &NODE_DATA(node)->node_zones[zone_type]; 2517 if (populated_zone(z)) { 2518 zoneref_set_zone(z, 2519 &zonelist->_zonerefs[pos++]); 2520 check_highest_zone(zone_type); 2521 } 2522 } 2523 } 2524 zonelist->_zonerefs[pos].zone = NULL; 2525 zonelist->_zonerefs[pos].zone_idx = 0; 2526} 2527 2528static int default_zonelist_order(void) 2529{ 2530 int nid, zone_type; 2531 unsigned long low_kmem_size,total_size; 2532 struct zone *z; 2533 int average_size; 2534 /* 2535 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem. 2536 * If they are really small and used heavily, the system can fall 2537 * into OOM very easily. 2538 * This function detect ZONE_DMA/DMA32 size and confgigures zone order. 2539 */ 2540 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */ 2541 low_kmem_size = 0; 2542 total_size = 0; 2543 for_each_online_node(nid) { 2544 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2545 z = &NODE_DATA(nid)->node_zones[zone_type]; 2546 if (populated_zone(z)) { 2547 if (zone_type < ZONE_NORMAL) 2548 low_kmem_size += z->present_pages; 2549 total_size += z->present_pages; 2550 } 2551 } 2552 } 2553 if (!low_kmem_size || /* there are no DMA area. */ 2554 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */ 2555 return ZONELIST_ORDER_NODE; 2556 /* 2557 * look into each node's config. 2558 * If there is a node whose DMA/DMA32 memory is very big area on 2559 * local memory, NODE_ORDER may be suitable. 2560 */ 2561 average_size = total_size / 2562 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1); 2563 for_each_online_node(nid) { 2564 low_kmem_size = 0; 2565 total_size = 0; 2566 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2567 z = &NODE_DATA(nid)->node_zones[zone_type]; 2568 if (populated_zone(z)) { 2569 if (zone_type < ZONE_NORMAL) 2570 low_kmem_size += z->present_pages; 2571 total_size += z->present_pages; 2572 } 2573 } 2574 if (low_kmem_size && 2575 total_size > average_size && /* ignore small node */ 2576 low_kmem_size > total_size * 70/100) 2577 return ZONELIST_ORDER_NODE; 2578 } 2579 return ZONELIST_ORDER_ZONE; 2580} 2581 2582static void set_zonelist_order(void) 2583{ 2584 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT) 2585 current_zonelist_order = default_zonelist_order(); 2586 else 2587 current_zonelist_order = user_zonelist_order; 2588} 2589 2590static void build_zonelists(pg_data_t *pgdat) 2591{ 2592 int j, node, load; 2593 enum zone_type i; 2594 nodemask_t used_mask; 2595 int local_node, prev_node; 2596 struct zonelist *zonelist; 2597 int order = current_zonelist_order; 2598 2599 /* initialize zonelists */ 2600 for (i = 0; i < MAX_ZONELISTS; i++) { 2601 zonelist = pgdat->node_zonelists + i; 2602 zonelist->_zonerefs[0].zone = NULL; 2603 zonelist->_zonerefs[0].zone_idx = 0; 2604 } 2605 2606 /* NUMA-aware ordering of nodes */ 2607 local_node = pgdat->node_id; 2608 load = nr_online_nodes; 2609 prev_node = local_node; 2610 nodes_clear(used_mask); 2611 2612 memset(node_order, 0, sizeof(node_order)); 2613 j = 0; 2614 2615 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 2616 int distance = node_distance(local_node, node); 2617 2618 /* 2619 * If another node is sufficiently far away then it is better 2620 * to reclaim pages in a zone before going off node. 2621 */ 2622 if (distance > RECLAIM_DISTANCE) 2623 zone_reclaim_mode = 1; 2624 2625 /* 2626 * We don't want to pressure a particular node. 2627 * So adding penalty to the first node in same 2628 * distance group to make it round-robin. 2629 */ 2630 if (distance != node_distance(local_node, prev_node)) 2631 node_load[node] = load; 2632 2633 prev_node = node; 2634 load--; 2635 if (order == ZONELIST_ORDER_NODE) 2636 build_zonelists_in_node_order(pgdat, node); 2637 else 2638 node_order[j++] = node; /* remember order */ 2639 } 2640 2641 if (order == ZONELIST_ORDER_ZONE) { 2642 /* calculate node order -- i.e., DMA last! */ 2643 build_zonelists_in_zone_order(pgdat, j); 2644 } 2645 2646 build_thisnode_zonelists(pgdat); 2647} 2648 2649/* Construct the zonelist performance cache - see further mmzone.h */ 2650static void build_zonelist_cache(pg_data_t *pgdat) 2651{ 2652 struct zonelist *zonelist; 2653 struct zonelist_cache *zlc; 2654 struct zoneref *z; 2655 2656 zonelist = &pgdat->node_zonelists[0]; 2657 zonelist->zlcache_ptr = zlc = &zonelist->zlcache; 2658 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 2659 for (z = zonelist->_zonerefs; z->zone; z++) 2660 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z); 2661} 2662 2663 2664#else /* CONFIG_NUMA */ 2665 2666static void set_zonelist_order(void) 2667{ 2668 current_zonelist_order = ZONELIST_ORDER_ZONE; 2669} 2670 2671static void build_zonelists(pg_data_t *pgdat) 2672{ 2673 int node, local_node; 2674 enum zone_type j; 2675 struct zonelist *zonelist; 2676 2677 local_node = pgdat->node_id; 2678 2679 zonelist = &pgdat->node_zonelists[0]; 2680 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2681 2682 /* 2683 * Now we build the zonelist so that it contains the zones 2684 * of all the other nodes. 2685 * We don't want to pressure a particular node, so when 2686 * building the zones for node N, we make sure that the 2687 * zones coming right after the local ones are those from 2688 * node N+1 (modulo N) 2689 */ 2690 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 2691 if (!node_online(node)) 2692 continue; 2693 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2694 MAX_NR_ZONES - 1); 2695 } 2696 for (node = 0; node < local_node; node++) { 2697 if (!node_online(node)) 2698 continue; 2699 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2700 MAX_NR_ZONES - 1); 2701 } 2702 2703 zonelist->_zonerefs[j].zone = NULL; 2704 zonelist->_zonerefs[j].zone_idx = 0; 2705} 2706 2707/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ 2708static void build_zonelist_cache(pg_data_t *pgdat) 2709{ 2710 pgdat->node_zonelists[0].zlcache_ptr = NULL; 2711} 2712 2713#endif /* CONFIG_NUMA */ 2714 2715/* return values int ....just for stop_machine() */ 2716static int __build_all_zonelists(void *dummy) 2717{ 2718 int nid; 2719 2720#ifdef CONFIG_NUMA 2721 memset(node_load, 0, sizeof(node_load)); 2722#endif 2723 for_each_online_node(nid) { 2724 pg_data_t *pgdat = NODE_DATA(nid); 2725 2726 build_zonelists(pgdat); 2727 build_zonelist_cache(pgdat); 2728 } 2729 return 0; 2730} 2731 2732void build_all_zonelists(void) 2733{ 2734 set_zonelist_order(); 2735 2736 if (system_state == SYSTEM_BOOTING) { 2737 __build_all_zonelists(NULL); 2738 mminit_verify_zonelist(); 2739 cpuset_init_current_mems_allowed(); 2740 } else { 2741 /* we have to stop all cpus to guarantee there is no user 2742 of zonelist */ 2743 stop_machine(__build_all_zonelists, NULL, NULL); 2744 /* cpuset refresh routine should be here */ 2745 } 2746 vm_total_pages = nr_free_pagecache_pages(); 2747 /* 2748 * Disable grouping by mobility if the number of pages in the 2749 * system is too low to allow the mechanism to work. It would be 2750 * more accurate, but expensive to check per-zone. This check is 2751 * made on memory-hotadd so a system can start with mobility 2752 * disabled and enable it later 2753 */ 2754 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) 2755 page_group_by_mobility_disabled = 1; 2756 else 2757 page_group_by_mobility_disabled = 0; 2758 2759 printk("Built %i zonelists in %s order, mobility grouping %s. " 2760 "Total pages: %ld\n", 2761 nr_online_nodes, 2762 zonelist_order_name[current_zonelist_order], 2763 page_group_by_mobility_disabled ? "off" : "on", 2764 vm_total_pages); 2765#ifdef CONFIG_NUMA 2766 printk("Policy zone: %s\n", zone_names[policy_zone]); 2767#endif 2768} 2769 2770/* 2771 * Helper functions to size the waitqueue hash table. 2772 * Essentially these want to choose hash table sizes sufficiently 2773 * large so that collisions trying to wait on pages are rare. 2774 * But in fact, the number of active page waitqueues on typical 2775 * systems is ridiculously low, less than 200. So this is even 2776 * conservative, even though it seems large. 2777 * 2778 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 2779 * waitqueues, i.e. the size of the waitq table given the number of pages. 2780 */ 2781#define PAGES_PER_WAITQUEUE 256 2782 2783#ifndef CONFIG_MEMORY_HOTPLUG 2784static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2785{ 2786 unsigned long size = 1; 2787 2788 pages /= PAGES_PER_WAITQUEUE; 2789 2790 while (size < pages) 2791 size <<= 1; 2792 2793 /* 2794 * Once we have dozens or even hundreds of threads sleeping 2795 * on IO we've got bigger problems than wait queue collision. 2796 * Limit the size of the wait table to a reasonable size. 2797 */ 2798 size = min(size, 4096UL); 2799 2800 return max(size, 4UL); 2801} 2802#else 2803/* 2804 * A zone's size might be changed by hot-add, so it is not possible to determine 2805 * a suitable size for its wait_table. So we use the maximum size now. 2806 * 2807 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: 2808 * 2809 * i386 (preemption config) : 4096 x 16 = 64Kbyte. 2810 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. 2811 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. 2812 * 2813 * The maximum entries are prepared when a zone's memory is (512K + 256) pages 2814 * or more by the traditional way. (See above). It equals: 2815 * 2816 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. 2817 * ia64(16K page size) : = ( 8G + 4M)byte. 2818 * powerpc (64K page size) : = (32G +16M)byte. 2819 */ 2820static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2821{ 2822 return 4096UL; 2823} 2824#endif 2825 2826/* 2827 * This is an integer logarithm so that shifts can be used later 2828 * to extract the more random high bits from the multiplicative 2829 * hash function before the remainder is taken. 2830 */ 2831static inline unsigned long wait_table_bits(unsigned long size) 2832{ 2833 return ffz(~size); 2834} 2835 2836#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) 2837 2838/* 2839 * Mark a number of pageblocks as MIGRATE_RESERVE. The number 2840 * of blocks reserved is based on min_wmark_pages(zone). The memory within 2841 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes 2842 * higher will lead to a bigger reserve which will get freed as contiguous 2843 * blocks as reclaim kicks in 2844 */ 2845static void setup_zone_migrate_reserve(struct zone *zone) 2846{ 2847 unsigned long start_pfn, pfn, end_pfn; 2848 struct page *page; 2849 unsigned long block_migratetype; 2850 int reserve; 2851 2852 /* Get the start pfn, end pfn and the number of blocks to reserve */ 2853 start_pfn = zone->zone_start_pfn; 2854 end_pfn = start_pfn + zone->spanned_pages; 2855 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >> 2856 pageblock_order; 2857 2858 /* 2859 * Reserve blocks are generally in place to help high-order atomic 2860 * allocations that are short-lived. A min_free_kbytes value that 2861 * would result in more than 2 reserve blocks for atomic allocations 2862 * is assumed to be in place to help anti-fragmentation for the 2863 * future allocation of hugepages at runtime. 2864 */ 2865 reserve = min(2, reserve); 2866 2867 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 2868 if (!pfn_valid(pfn)) 2869 continue; 2870 page = pfn_to_page(pfn); 2871 2872 /* Watch out for overlapping nodes */ 2873 if (page_to_nid(page) != zone_to_nid(zone)) 2874 continue; 2875 2876 /* Blocks with reserved pages will never free, skip them. */ 2877 if (PageReserved(page)) 2878 continue; 2879 2880 block_migratetype = get_pageblock_migratetype(page); 2881 2882 /* If this block is reserved, account for it */ 2883 if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) { 2884 reserve--; 2885 continue; 2886 } 2887 2888 /* Suitable for reserving if this block is movable */ 2889 if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) { 2890 set_pageblock_migratetype(page, MIGRATE_RESERVE); 2891 move_freepages_block(zone, page, MIGRATE_RESERVE); 2892 reserve--; 2893 continue; 2894 } 2895 2896 /* 2897 * If the reserve is met and this is a previous reserved block, 2898 * take it back 2899 */ 2900 if (block_migratetype == MIGRATE_RESERVE) { 2901 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 2902 move_freepages_block(zone, page, MIGRATE_MOVABLE); 2903 } 2904 } 2905} 2906 2907/* 2908 * Initially all pages are reserved - free ones are freed 2909 * up by free_all_bootmem() once the early boot process is 2910 * done. Non-atomic initialization, single-pass. 2911 */ 2912void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 2913 unsigned long start_pfn, enum memmap_context context) 2914{ 2915 struct page *page; 2916 unsigned long end_pfn = start_pfn + size; 2917 unsigned long pfn; 2918 struct zone *z; 2919 2920 if (highest_memmap_pfn < end_pfn - 1) 2921 highest_memmap_pfn = end_pfn - 1; 2922 2923 z = &NODE_DATA(nid)->node_zones[zone]; 2924 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 2925 /* 2926 * There can be holes in boot-time mem_map[]s 2927 * handed to this function. They do not 2928 * exist on hotplugged memory. 2929 */ 2930 if (context == MEMMAP_EARLY) { 2931 if (!early_pfn_valid(pfn)) 2932 continue; 2933 if (!early_pfn_in_nid(pfn, nid)) 2934 continue; 2935 } 2936 page = pfn_to_page(pfn); 2937 set_page_links(page, zone, nid, pfn); 2938 mminit_verify_page_links(page, zone, nid, pfn); 2939 init_page_count(page); 2940 reset_page_mapcount(page); 2941 SetPageReserved(page); 2942 /* 2943 * Mark the block movable so that blocks are reserved for 2944 * movable at startup. This will force kernel allocations 2945 * to reserve their blocks rather than leaking throughout 2946 * the address space during boot when many long-lived 2947 * kernel allocations are made. Later some blocks near 2948 * the start are marked MIGRATE_RESERVE by 2949 * setup_zone_migrate_reserve() 2950 * 2951 * bitmap is created for zone's valid pfn range. but memmap 2952 * can be created for invalid pages (for alignment) 2953 * check here not to call set_pageblock_migratetype() against 2954 * pfn out of zone. 2955 */ 2956 if ((z->zone_start_pfn <= pfn) 2957 && (pfn < z->zone_start_pfn + z->spanned_pages) 2958 && !(pfn & (pageblock_nr_pages - 1))) 2959 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 2960 2961 INIT_LIST_HEAD(&page->lru); 2962#ifdef WANT_PAGE_VIRTUAL 2963 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 2964 if (!is_highmem_idx(zone)) 2965 set_page_address(page, __va(pfn << PAGE_SHIFT)); 2966#endif 2967 } 2968} 2969 2970static void __meminit zone_init_free_lists(struct zone *zone) 2971{ 2972 int order, t; 2973 for_each_migratetype_order(order, t) { 2974 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); 2975 zone->free_area[order].nr_free = 0; 2976 } 2977} 2978 2979#ifndef __HAVE_ARCH_MEMMAP_INIT 2980#define memmap_init(size, nid, zone, start_pfn) \ 2981 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) 2982#endif 2983 2984static int zone_batchsize(struct zone *zone) 2985{ 2986#ifdef CONFIG_MMU 2987 int batch; 2988 2989 /* 2990 * The per-cpu-pages pools are set to around 1000th of the 2991 * size of the zone. But no more than 1/2 of a meg. 2992 * 2993 * OK, so we don't know how big the cache is. So guess. 2994 */ 2995 batch = zone->present_pages / 1024; 2996 if (batch * PAGE_SIZE > 512 * 1024) 2997 batch = (512 * 1024) / PAGE_SIZE; 2998 batch /= 4; /* We effectively *= 4 below */ 2999 if (batch < 1) 3000 batch = 1; 3001 3002 /* 3003 * Clamp the batch to a 2^n - 1 value. Having a power 3004 * of 2 value was found to be more likely to have 3005 * suboptimal cache aliasing properties in some cases. 3006 * 3007 * For example if 2 tasks are alternately allocating 3008 * batches of pages, one task can end up with a lot 3009 * of pages of one half of the possible page colors 3010 * and the other with pages of the other colors. 3011 */ 3012 batch = rounddown_pow_of_two(batch + batch/2) - 1; 3013 3014 return batch; 3015 3016#else 3017 /* The deferral and batching of frees should be suppressed under NOMMU 3018 * conditions. 3019 * 3020 * The problem is that NOMMU needs to be able to allocate large chunks 3021 * of contiguous memory as there's no hardware page translation to 3022 * assemble apparent contiguous memory from discontiguous pages. 3023 * 3024 * Queueing large contiguous runs of pages for batching, however, 3025 * causes the pages to actually be freed in smaller chunks. As there 3026 * can be a significant delay between the individual batches being 3027 * recycled, this leads to the once large chunks of space being 3028 * fragmented and becoming unavailable for high-order allocations. 3029 */ 3030 return 0; 3031#endif 3032} 3033 3034static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 3035{ 3036 struct per_cpu_pages *pcp; 3037 int migratetype; 3038 3039 memset(p, 0, sizeof(*p)); 3040 3041 pcp = &p->pcp; 3042 pcp->count = 0; 3043 pcp->high = 6 * batch; 3044 pcp->batch = max(1UL, 1 * batch); 3045 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++) 3046 INIT_LIST_HEAD(&pcp->lists[migratetype]); 3047} 3048 3049/* 3050 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist 3051 * to the value high for the pageset p. 3052 */ 3053 3054static void setup_pagelist_highmark(struct per_cpu_pageset *p, 3055 unsigned long high) 3056{ 3057 struct per_cpu_pages *pcp; 3058 3059 pcp = &p->pcp; 3060 pcp->high = high; 3061 pcp->batch = max(1UL, high/4); 3062 if ((high/4) > (PAGE_SHIFT * 8)) 3063 pcp->batch = PAGE_SHIFT * 8; 3064} 3065 3066 3067#ifdef CONFIG_NUMA 3068/* 3069 * Boot pageset table. One per cpu which is going to be used for all 3070 * zones and all nodes. The parameters will be set in such a way 3071 * that an item put on a list will immediately be handed over to 3072 * the buddy list. This is safe since pageset manipulation is done 3073 * with interrupts disabled. 3074 * 3075 * Some NUMA counter updates may also be caught by the boot pagesets. 3076 * 3077 * The boot_pagesets must be kept even after bootup is complete for 3078 * unused processors and/or zones. They do play a role for bootstrapping 3079 * hotplugged processors. 3080 * 3081 * zoneinfo_show() and maybe other functions do 3082 * not check if the processor is online before following the pageset pointer. 3083 * Other parts of the kernel may not check if the zone is available. 3084 */ 3085static struct per_cpu_pageset boot_pageset[NR_CPUS]; 3086 3087/* 3088 * Dynamically allocate memory for the 3089 * per cpu pageset array in struct zone. 3090 */ 3091static int __cpuinit process_zones(int cpu) 3092{ 3093 struct zone *zone, *dzone; 3094 int node = cpu_to_node(cpu); 3095 3096 node_set_state(node, N_CPU); /* this node has a cpu */ 3097 3098 for_each_populated_zone(zone) { 3099 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset), 3100 GFP_KERNEL, node); 3101 if (!zone_pcp(zone, cpu)) 3102 goto bad; 3103 3104 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone)); 3105 3106 if (percpu_pagelist_fraction) 3107 setup_pagelist_highmark(zone_pcp(zone, cpu), 3108 (zone->present_pages / percpu_pagelist_fraction)); 3109 } 3110 3111 return 0; 3112bad: 3113 for_each_zone(dzone) { 3114 if (!populated_zone(dzone)) 3115 continue; 3116 if (dzone == zone) 3117 break; 3118 kfree(zone_pcp(dzone, cpu)); 3119 zone_pcp(dzone, cpu) = &boot_pageset[cpu]; 3120 } 3121 return -ENOMEM; 3122} 3123 3124static inline void free_zone_pagesets(int cpu) 3125{ 3126 struct zone *zone; 3127 3128 for_each_zone(zone) { 3129 struct per_cpu_pageset *pset = zone_pcp(zone, cpu); 3130 3131 /* Free per_cpu_pageset if it is slab allocated */ 3132 if (pset != &boot_pageset[cpu]) 3133 kfree(pset); 3134 zone_pcp(zone, cpu) = &boot_pageset[cpu]; 3135 } 3136} 3137 3138static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb, 3139 unsigned long action, 3140 void *hcpu) 3141{ 3142 int cpu = (long)hcpu; 3143 int ret = NOTIFY_OK; 3144 3145 switch (action) { 3146 case CPU_UP_PREPARE: 3147 case CPU_UP_PREPARE_FROZEN: 3148 if (process_zones(cpu)) 3149 ret = NOTIFY_BAD; 3150 break; 3151 case CPU_UP_CANCELED: 3152 case CPU_UP_CANCELED_FROZEN: 3153 case CPU_DEAD: 3154 case CPU_DEAD_FROZEN: 3155 free_zone_pagesets(cpu); 3156 break; 3157 default: 3158 break; 3159 } 3160 return ret; 3161} 3162 3163static struct notifier_block __cpuinitdata pageset_notifier = 3164 { &pageset_cpuup_callback, NULL, 0 }; 3165 3166void __init setup_per_cpu_pageset(void) 3167{ 3168 int err; 3169 3170 /* Initialize per_cpu_pageset for cpu 0. 3171 * A cpuup callback will do this for every cpu 3172 * as it comes online 3173 */ 3174 err = process_zones(smp_processor_id()); 3175 BUG_ON(err); 3176 register_cpu_notifier(&pageset_notifier); 3177} 3178 3179#endif 3180 3181static noinline __init_refok 3182int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 3183{ 3184 int i; 3185 struct pglist_data *pgdat = zone->zone_pgdat; 3186 size_t alloc_size; 3187 3188 /* 3189 * The per-page waitqueue mechanism uses hashed waitqueues 3190 * per zone. 3191 */ 3192 zone->wait_table_hash_nr_entries = 3193 wait_table_hash_nr_entries(zone_size_pages); 3194 zone->wait_table_bits = 3195 wait_table_bits(zone->wait_table_hash_nr_entries); 3196 alloc_size = zone->wait_table_hash_nr_entries 3197 * sizeof(wait_queue_head_t); 3198 3199 if (!slab_is_available()) { 3200 zone->wait_table = (wait_queue_head_t *) 3201 alloc_bootmem_node(pgdat, alloc_size); 3202 } else { 3203 /* 3204 * This case means that a zone whose size was 0 gets new memory 3205 * via memory hot-add. 3206 * But it may be the case that a new node was hot-added. In 3207 * this case vmalloc() will not be able to use this new node's 3208 * memory - this wait_table must be initialized to use this new 3209 * node itself as well. 3210 * To use this new node's memory, further consideration will be 3211 * necessary. 3212 */ 3213 zone->wait_table = vmalloc(alloc_size); 3214 } 3215 if (!zone->wait_table) 3216 return -ENOMEM; 3217 3218 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i) 3219 init_waitqueue_head(zone->wait_table + i); 3220 3221 return 0; 3222} 3223 3224static int __zone_pcp_update(void *data) 3225{ 3226 struct zone *zone = data; 3227 int cpu; 3228 unsigned long batch = zone_batchsize(zone), flags; 3229 3230 for (cpu = 0; cpu < NR_CPUS; cpu++) { 3231 struct per_cpu_pageset *pset; 3232 struct per_cpu_pages *pcp; 3233 3234 pset = zone_pcp(zone, cpu); 3235 pcp = &pset->pcp; 3236 3237 local_irq_save(flags); 3238 free_pcppages_bulk(zone, pcp->count, pcp); 3239 setup_pageset(pset, batch); 3240 local_irq_restore(flags); 3241 } 3242 return 0; 3243} 3244 3245void zone_pcp_update(struct zone *zone) 3246{ 3247 stop_machine(__zone_pcp_update, zone, NULL); 3248} 3249 3250static __meminit void zone_pcp_init(struct zone *zone) 3251{ 3252 int cpu; 3253 unsigned long batch = zone_batchsize(zone); 3254 3255 for (cpu = 0; cpu < NR_CPUS; cpu++) { 3256#ifdef CONFIG_NUMA 3257 /* Early boot. Slab allocator not functional yet */ 3258 zone_pcp(zone, cpu) = &boot_pageset[cpu]; 3259 setup_pageset(&boot_pageset[cpu],0); 3260#else 3261 setup_pageset(zone_pcp(zone,cpu), batch); 3262#endif 3263 } 3264 if (zone->present_pages) 3265 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", 3266 zone->name, zone->present_pages, batch); 3267} 3268 3269__meminit int init_currently_empty_zone(struct zone *zone, 3270 unsigned long zone_start_pfn, 3271 unsigned long size, 3272 enum memmap_context context) 3273{ 3274 struct pglist_data *pgdat = zone->zone_pgdat; 3275 int ret; 3276 ret = zone_wait_table_init(zone, size); 3277 if (ret) 3278 return ret; 3279 pgdat->nr_zones = zone_idx(zone) + 1; 3280 3281 zone->zone_start_pfn = zone_start_pfn; 3282 3283 mminit_dprintk(MMINIT_TRACE, "memmap_init", 3284 "Initialising map node %d zone %lu pfns %lu -> %lu\n", 3285 pgdat->node_id, 3286 (unsigned long)zone_idx(zone), 3287 zone_start_pfn, (zone_start_pfn + size)); 3288 3289 zone_init_free_lists(zone); 3290 3291 return 0; 3292} 3293 3294#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3295/* 3296 * Basic iterator support. Return the first range of PFNs for a node 3297 * Note: nid == MAX_NUMNODES returns first region regardless of node 3298 */ 3299static int __meminit first_active_region_index_in_nid(int nid) 3300{ 3301 int i; 3302 3303 for (i = 0; i < nr_nodemap_entries; i++) 3304 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid) 3305 return i; 3306 3307 return -1; 3308} 3309 3310/* 3311 * Basic iterator support. Return the next active range of PFNs for a node 3312 * Note: nid == MAX_NUMNODES returns next region regardless of node 3313 */ 3314static int __meminit next_active_region_index_in_nid(int index, int nid) 3315{ 3316 for (index = index + 1; index < nr_nodemap_entries; index++) 3317 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid) 3318 return index; 3319 3320 return -1; 3321} 3322 3323#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID 3324/* 3325 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. 3326 * Architectures may implement their own version but if add_active_range() 3327 * was used and there are no special requirements, this is a convenient 3328 * alternative 3329 */ 3330int __meminit __early_pfn_to_nid(unsigned long pfn) 3331{ 3332 int i; 3333 3334 for (i = 0; i < nr_nodemap_entries; i++) { 3335 unsigned long start_pfn = early_node_map[i].start_pfn; 3336 unsigned long end_pfn = early_node_map[i].end_pfn; 3337 3338 if (start_pfn <= pfn && pfn < end_pfn) 3339 return early_node_map[i].nid; 3340 } 3341 /* This is a memory hole */ 3342 return -1; 3343} 3344#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ 3345 3346int __meminit early_pfn_to_nid(unsigned long pfn) 3347{ 3348 int nid; 3349 3350 nid = __early_pfn_to_nid(pfn); 3351 if (nid >= 0) 3352 return nid; 3353 /* just returns 0 */ 3354 return 0; 3355} 3356 3357#ifdef CONFIG_NODES_SPAN_OTHER_NODES 3358bool __meminit early_pfn_in_nid(unsigned long pfn, int node) 3359{ 3360 int nid; 3361 3362 nid = __early_pfn_to_nid(pfn); 3363 if (nid >= 0 && nid != node) 3364 return false; 3365 return true; 3366} 3367#endif 3368 3369/* Basic iterator support to walk early_node_map[] */ 3370#define for_each_active_range_index_in_nid(i, nid) \ 3371 for (i = first_active_region_index_in_nid(nid); i != -1; \ 3372 i = next_active_region_index_in_nid(i, nid)) 3373 3374/** 3375 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range 3376 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. 3377 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node 3378 * 3379 * If an architecture guarantees that all ranges registered with 3380 * add_active_ranges() contain no holes and may be freed, this 3381 * this function may be used instead of calling free_bootmem() manually. 3382 */ 3383void __init free_bootmem_with_active_regions(int nid, 3384 unsigned long max_low_pfn) 3385{ 3386 int i; 3387 3388 for_each_active_range_index_in_nid(i, nid) { 3389 unsigned long size_pages = 0; 3390 unsigned long end_pfn = early_node_map[i].end_pfn; 3391 3392 if (early_node_map[i].start_pfn >= max_low_pfn) 3393 continue; 3394 3395 if (end_pfn > max_low_pfn) 3396 end_pfn = max_low_pfn; 3397 3398 size_pages = end_pfn - early_node_map[i].start_pfn; 3399 free_bootmem_node(NODE_DATA(early_node_map[i].nid), 3400 PFN_PHYS(early_node_map[i].start_pfn), 3401 size_pages << PAGE_SHIFT); 3402 } 3403} 3404 3405void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data) 3406{ 3407 int i; 3408 int ret; 3409 3410 for_each_active_range_index_in_nid(i, nid) { 3411 ret = work_fn(early_node_map[i].start_pfn, 3412 early_node_map[i].end_pfn, data); 3413 if (ret) 3414 break; 3415 } 3416} 3417/** 3418 * sparse_memory_present_with_active_regions - Call memory_present for each active range 3419 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. 3420 * 3421 * If an architecture guarantees that all ranges registered with 3422 * add_active_ranges() contain no holes and may be freed, this 3423 * function may be used instead of calling memory_present() manually. 3424 */ 3425void __init sparse_memory_present_with_active_regions(int nid) 3426{ 3427 int i; 3428 3429 for_each_active_range_index_in_nid(i, nid) 3430 memory_present(early_node_map[i].nid, 3431 early_node_map[i].start_pfn, 3432 early_node_map[i].end_pfn); 3433} 3434 3435/** 3436 * get_pfn_range_for_nid - Return the start and end page frames for a node 3437 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. 3438 * @start_pfn: Passed by reference. On return, it will have the node start_pfn. 3439 * @end_pfn: Passed by reference. On return, it will have the node end_pfn. 3440 * 3441 * It returns the start and end page frame of a node based on information 3442 * provided by an arch calling add_active_range(). If called for a node 3443 * with no available memory, a warning is printed and the start and end 3444 * PFNs will be 0. 3445 */ 3446void __meminit get_pfn_range_for_nid(unsigned int nid, 3447 unsigned long *start_pfn, unsigned long *end_pfn) 3448{ 3449 int i; 3450 *start_pfn = -1UL; 3451 *end_pfn = 0; 3452 3453 for_each_active_range_index_in_nid(i, nid) { 3454 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn); 3455 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn); 3456 } 3457 3458 if (*start_pfn == -1UL) 3459 *start_pfn = 0; 3460} 3461 3462/* 3463 * This finds a zone that can be used for ZONE_MOVABLE pages. The 3464 * assumption is made that zones within a node are ordered in monotonic 3465 * increasing memory addresses so that the "highest" populated zone is used 3466 */ 3467static void __init find_usable_zone_for_movable(void) 3468{ 3469 int zone_index; 3470 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { 3471 if (zone_index == ZONE_MOVABLE) 3472 continue; 3473 3474 if (arch_zone_highest_possible_pfn[zone_index] > 3475 arch_zone_lowest_possible_pfn[zone_index]) 3476 break; 3477 } 3478 3479 VM_BUG_ON(zone_index == -1); 3480 movable_zone = zone_index; 3481} 3482 3483/* 3484 * The zone ranges provided by the architecture do not include ZONE_MOVABLE 3485 * because it is sized independant of architecture. Unlike the other zones, 3486 * the starting point for ZONE_MOVABLE is not fixed. It may be different 3487 * in each node depending on the size of each node and how evenly kernelcore 3488 * is distributed. This helper function adjusts the zone ranges 3489 * provided by the architecture for a given node by using the end of the 3490 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that 3491 * zones within a node are in order of monotonic increases memory addresses 3492 */ 3493static void __meminit adjust_zone_range_for_zone_movable(int nid, 3494 unsigned long zone_type, 3495 unsigned long node_start_pfn, 3496 unsigned long node_end_pfn, 3497 unsigned long *zone_start_pfn, 3498 unsigned long *zone_end_pfn) 3499{ 3500 /* Only adjust if ZONE_MOVABLE is on this node */ 3501 if (zone_movable_pfn[nid]) { 3502 /* Size ZONE_MOVABLE */ 3503 if (zone_type == ZONE_MOVABLE) { 3504 *zone_start_pfn = zone_movable_pfn[nid]; 3505 *zone_end_pfn = min(node_end_pfn, 3506 arch_zone_highest_possible_pfn[movable_zone]); 3507 3508 /* Adjust for ZONE_MOVABLE starting within this range */ 3509 } else if (*zone_start_pfn < zone_movable_pfn[nid] && 3510 *zone_end_pfn > zone_movable_pfn[nid]) { 3511 *zone_end_pfn = zone_movable_pfn[nid]; 3512 3513 /* Check if this whole range is within ZONE_MOVABLE */ 3514 } else if (*zone_start_pfn >= zone_movable_pfn[nid]) 3515 *zone_start_pfn = *zone_end_pfn; 3516 } 3517} 3518 3519/* 3520 * Return the number of pages a zone spans in a node, including holes 3521 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() 3522 */ 3523static unsigned long __meminit zone_spanned_pages_in_node(int nid, 3524 unsigned long zone_type, 3525 unsigned long *ignored) 3526{ 3527 unsigned long node_start_pfn, node_end_pfn; 3528 unsigned long zone_start_pfn, zone_end_pfn; 3529 3530 /* Get the start and end of the node and zone */ 3531 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3532 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; 3533 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; 3534 adjust_zone_range_for_zone_movable(nid, zone_type, 3535 node_start_pfn, node_end_pfn, 3536 &zone_start_pfn, &zone_end_pfn); 3537 3538 /* Check that this node has pages within the zone's required range */ 3539 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) 3540 return 0; 3541 3542 /* Move the zone boundaries inside the node if necessary */ 3543 zone_end_pfn = min(zone_end_pfn, node_end_pfn); 3544 zone_start_pfn = max(zone_start_pfn, node_start_pfn); 3545 3546 /* Return the spanned pages */ 3547 return zone_end_pfn - zone_start_pfn; 3548} 3549 3550/* 3551 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, 3552 * then all holes in the requested range will be accounted for. 3553 */ 3554static unsigned long __meminit __absent_pages_in_range(int nid, 3555 unsigned long range_start_pfn, 3556 unsigned long range_end_pfn) 3557{ 3558 int i = 0; 3559 unsigned long prev_end_pfn = 0, hole_pages = 0; 3560 unsigned long start_pfn; 3561 3562 /* Find the end_pfn of the first active range of pfns in the node */ 3563 i = first_active_region_index_in_nid(nid); 3564 if (i == -1) 3565 return 0; 3566 3567 prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 3568 3569 /* Account for ranges before physical memory on this node */ 3570 if (early_node_map[i].start_pfn > range_start_pfn) 3571 hole_pages = prev_end_pfn - range_start_pfn; 3572 3573 /* Find all holes for the zone within the node */ 3574 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) { 3575 3576 /* No need to continue if prev_end_pfn is outside the zone */ 3577 if (prev_end_pfn >= range_end_pfn) 3578 break; 3579 3580 /* Make sure the end of the zone is not within the hole */ 3581 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 3582 prev_end_pfn = max(prev_end_pfn, range_start_pfn); 3583 3584 /* Update the hole size cound and move on */ 3585 if (start_pfn > range_start_pfn) { 3586 BUG_ON(prev_end_pfn > start_pfn); 3587 hole_pages += start_pfn - prev_end_pfn; 3588 } 3589 prev_end_pfn = early_node_map[i].end_pfn; 3590 } 3591 3592 /* Account for ranges past physical memory on this node */ 3593 if (range_end_pfn > prev_end_pfn) 3594 hole_pages += range_end_pfn - 3595 max(range_start_pfn, prev_end_pfn); 3596 3597 return hole_pages; 3598} 3599 3600/** 3601 * absent_pages_in_range - Return number of page frames in holes within a range 3602 * @start_pfn: The start PFN to start searching for holes 3603 * @end_pfn: The end PFN to stop searching for holes 3604 * 3605 * It returns the number of pages frames in memory holes within a range. 3606 */ 3607unsigned long __init absent_pages_in_range(unsigned long start_pfn, 3608 unsigned long end_pfn) 3609{ 3610 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); 3611} 3612 3613/* Return the number of page frames in holes in a zone on a node */ 3614static unsigned long __meminit zone_absent_pages_in_node(int nid, 3615 unsigned long zone_type, 3616 unsigned long *ignored) 3617{ 3618 unsigned long node_start_pfn, node_end_pfn; 3619 unsigned long zone_start_pfn, zone_end_pfn; 3620 3621 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3622 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type], 3623 node_start_pfn); 3624 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type], 3625 node_end_pfn); 3626 3627 adjust_zone_range_for_zone_movable(nid, zone_type, 3628 node_start_pfn, node_end_pfn, 3629 &zone_start_pfn, &zone_end_pfn); 3630 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); 3631} 3632 3633#else 3634static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, 3635 unsigned long zone_type, 3636 unsigned long *zones_size) 3637{ 3638 return zones_size[zone_type]; 3639} 3640 3641static inline unsigned long __meminit zone_absent_pages_in_node(int nid, 3642 unsigned long zone_type, 3643 unsigned long *zholes_size) 3644{ 3645 if (!zholes_size) 3646 return 0; 3647 3648 return zholes_size[zone_type]; 3649} 3650 3651#endif 3652 3653static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, 3654 unsigned long *zones_size, unsigned long *zholes_size) 3655{ 3656 unsigned long realtotalpages, totalpages = 0; 3657 enum zone_type i; 3658 3659 for (i = 0; i < MAX_NR_ZONES; i++) 3660 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i, 3661 zones_size); 3662 pgdat->node_spanned_pages = totalpages; 3663 3664 realtotalpages = totalpages; 3665 for (i = 0; i < MAX_NR_ZONES; i++) 3666 realtotalpages -= 3667 zone_absent_pages_in_node(pgdat->node_id, i, 3668 zholes_size); 3669 pgdat->node_present_pages = realtotalpages; 3670 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, 3671 realtotalpages); 3672} 3673 3674#ifndef CONFIG_SPARSEMEM 3675/* 3676 * Calculate the size of the zone->blockflags rounded to an unsigned long 3677 * Start by making sure zonesize is a multiple of pageblock_order by rounding 3678 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally 3679 * round what is now in bits to nearest long in bits, then return it in 3680 * bytes. 3681 */ 3682static unsigned long __init usemap_size(unsigned long zonesize) 3683{ 3684 unsigned long usemapsize; 3685 3686 usemapsize = roundup(zonesize, pageblock_nr_pages); 3687 usemapsize = usemapsize >> pageblock_order; 3688 usemapsize *= NR_PAGEBLOCK_BITS; 3689 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); 3690 3691 return usemapsize / 8; 3692} 3693 3694static void __init setup_usemap(struct pglist_data *pgdat, 3695 struct zone *zone, unsigned long zonesize) 3696{ 3697 unsigned long usemapsize = usemap_size(zonesize); 3698 zone->pageblock_flags = NULL; 3699 if (usemapsize) 3700 zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize); 3701} 3702#else 3703static void inline setup_usemap(struct pglist_data *pgdat, 3704 struct zone *zone, unsigned long zonesize) {} 3705#endif /* CONFIG_SPARSEMEM */ 3706 3707#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 3708 3709/* Return a sensible default order for the pageblock size. */ 3710static inline int pageblock_default_order(void) 3711{ 3712 if (HPAGE_SHIFT > PAGE_SHIFT) 3713 return HUGETLB_PAGE_ORDER; 3714 3715 return MAX_ORDER-1; 3716} 3717 3718/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ 3719static inline void __init set_pageblock_order(unsigned int order) 3720{ 3721 /* Check that pageblock_nr_pages has not already been setup */ 3722 if (pageblock_order) 3723 return; 3724 3725 /* 3726 * Assume the largest contiguous order of interest is a huge page. 3727 * This value may be variable depending on boot parameters on IA64 3728 */ 3729 pageblock_order = order; 3730} 3731#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 3732 3733/* 3734 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() 3735 * and pageblock_default_order() are unused as pageblock_order is set 3736 * at compile-time. See include/linux/pageblock-flags.h for the values of 3737 * pageblock_order based on the kernel config 3738 */ 3739static inline int pageblock_default_order(unsigned int order) 3740{ 3741 return MAX_ORDER-1; 3742} 3743#define set_pageblock_order(x) do {} while (0) 3744 3745#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 3746 3747/* 3748 * Set up the zone data structures: 3749 * - mark all pages reserved 3750 * - mark all memory queues empty 3751 * - clear the memory bitmaps 3752 */ 3753static void __paginginit free_area_init_core(struct pglist_data *pgdat, 3754 unsigned long *zones_size, unsigned long *zholes_size) 3755{ 3756 enum zone_type j; 3757 int nid = pgdat->node_id; 3758 unsigned long zone_start_pfn = pgdat->node_start_pfn; 3759 int ret; 3760 3761 pgdat_resize_init(pgdat); 3762 pgdat->nr_zones = 0; 3763 init_waitqueue_head(&pgdat->kswapd_wait); 3764 pgdat->kswapd_max_order = 0; 3765 pgdat_page_cgroup_init(pgdat); 3766 3767 for (j = 0; j < MAX_NR_ZONES; j++) { 3768 struct zone *zone = pgdat->node_zones + j; 3769 unsigned long size, realsize, memmap_pages; 3770 enum lru_list l; 3771 3772 size = zone_spanned_pages_in_node(nid, j, zones_size); 3773 realsize = size - zone_absent_pages_in_node(nid, j, 3774 zholes_size); 3775 3776 /* 3777 * Adjust realsize so that it accounts for how much memory 3778 * is used by this zone for memmap. This affects the watermark 3779 * and per-cpu initialisations 3780 */ 3781 memmap_pages = 3782 PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT; 3783 if (realsize >= memmap_pages) { 3784 realsize -= memmap_pages; 3785 if (memmap_pages) 3786 printk(KERN_DEBUG 3787 " %s zone: %lu pages used for memmap\n", 3788 zone_names[j], memmap_pages); 3789 } else 3790 printk(KERN_WARNING 3791 " %s zone: %lu pages exceeds realsize %lu\n", 3792 zone_names[j], memmap_pages, realsize); 3793 3794 /* Account for reserved pages */ 3795 if (j == 0 && realsize > dma_reserve) { 3796 realsize -= dma_reserve; 3797 printk(KERN_DEBUG " %s zone: %lu pages reserved\n", 3798 zone_names[0], dma_reserve); 3799 } 3800 3801 if (!is_highmem_idx(j)) 3802 nr_kernel_pages += realsize; 3803 nr_all_pages += realsize; 3804 3805 zone->spanned_pages = size; 3806 zone->present_pages = realsize; 3807#ifdef CONFIG_NUMA 3808 zone->node = nid; 3809 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio) 3810 / 100; 3811 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100; 3812#endif 3813 zone->name = zone_names[j]; 3814 spin_lock_init(&zone->lock); 3815 spin_lock_init(&zone->lru_lock); 3816 zone_seqlock_init(zone); 3817 zone->zone_pgdat = pgdat; 3818 3819 zone->prev_priority = DEF_PRIORITY; 3820 3821 zone_pcp_init(zone); 3822 for_each_lru(l) { 3823 INIT_LIST_HEAD(&zone->lru[l].list); 3824 zone->reclaim_stat.nr_saved_scan[l] = 0; 3825 } 3826 zone->reclaim_stat.recent_rotated[0] = 0; 3827 zone->reclaim_stat.recent_rotated[1] = 0; 3828 zone->reclaim_stat.recent_scanned[0] = 0; 3829 zone->reclaim_stat.recent_scanned[1] = 0; 3830 zap_zone_vm_stats(zone); 3831 zone->flags = 0; 3832 if (!size) 3833 continue; 3834 3835 set_pageblock_order(pageblock_default_order()); 3836 setup_usemap(pgdat, zone, size); 3837 ret = init_currently_empty_zone(zone, zone_start_pfn, 3838 size, MEMMAP_EARLY); 3839 BUG_ON(ret); 3840 memmap_init(size, nid, j, zone_start_pfn); 3841 zone_start_pfn += size; 3842 } 3843} 3844 3845static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat) 3846{ 3847 /* Skip empty nodes */ 3848 if (!pgdat->node_spanned_pages) 3849 return; 3850 3851#ifdef CONFIG_FLAT_NODE_MEM_MAP 3852 /* ia64 gets its own node_mem_map, before this, without bootmem */ 3853 if (!pgdat->node_mem_map) { 3854 unsigned long size, start, end; 3855 struct page *map; 3856 3857 /* 3858 * The zone's endpoints aren't required to be MAX_ORDER 3859 * aligned but the node_mem_map endpoints must be in order 3860 * for the buddy allocator to function correctly. 3861 */ 3862 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); 3863 end = pgdat->node_start_pfn + pgdat->node_spanned_pages; 3864 end = ALIGN(end, MAX_ORDER_NR_PAGES); 3865 size = (end - start) * sizeof(struct page); 3866 map = alloc_remap(pgdat->node_id, size); 3867 if (!map) 3868 map = alloc_bootmem_node(pgdat, size); 3869 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); 3870 } 3871#ifndef CONFIG_NEED_MULTIPLE_NODES 3872 /* 3873 * With no DISCONTIG, the global mem_map is just set as node 0's 3874 */ 3875 if (pgdat == NODE_DATA(0)) { 3876 mem_map = NODE_DATA(0)->node_mem_map; 3877#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3878 if (page_to_pfn(mem_map) != pgdat->node_start_pfn) 3879 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET); 3880#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 3881 } 3882#endif 3883#endif /* CONFIG_FLAT_NODE_MEM_MAP */ 3884} 3885 3886void __paginginit free_area_init_node(int nid, unsigned long *zones_size, 3887 unsigned long node_start_pfn, unsigned long *zholes_size) 3888{ 3889 pg_data_t *pgdat = NODE_DATA(nid); 3890 3891 pgdat->node_id = nid; 3892 pgdat->node_start_pfn = node_start_pfn; 3893 calculate_node_totalpages(pgdat, zones_size, zholes_size); 3894 3895 alloc_node_mem_map(pgdat); 3896#ifdef CONFIG_FLAT_NODE_MEM_MAP 3897 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n", 3898 nid, (unsigned long)pgdat, 3899 (unsigned long)pgdat->node_mem_map); 3900#endif 3901 3902 free_area_init_core(pgdat, zones_size, zholes_size); 3903} 3904 3905#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3906 3907#if MAX_NUMNODES > 1 3908/* 3909 * Figure out the number of possible node ids. 3910 */ 3911static void __init setup_nr_node_ids(void) 3912{ 3913 unsigned int node; 3914 unsigned int highest = 0; 3915 3916 for_each_node_mask(node, node_possible_map) 3917 highest = node; 3918 nr_node_ids = highest + 1; 3919} 3920#else 3921static inline void setup_nr_node_ids(void) 3922{ 3923} 3924#endif 3925 3926/** 3927 * add_active_range - Register a range of PFNs backed by physical memory 3928 * @nid: The node ID the range resides on 3929 * @start_pfn: The start PFN of the available physical memory 3930 * @end_pfn: The end PFN of the available physical memory 3931 * 3932 * These ranges are stored in an early_node_map[] and later used by 3933 * free_area_init_nodes() to calculate zone sizes and holes. If the 3934 * range spans a memory hole, it is up to the architecture to ensure 3935 * the memory is not freed by the bootmem allocator. If possible 3936 * the range being registered will be merged with existing ranges. 3937 */ 3938void __init add_active_range(unsigned int nid, unsigned long start_pfn, 3939 unsigned long end_pfn) 3940{ 3941 int i; 3942 3943 mminit_dprintk(MMINIT_TRACE, "memory_register", 3944 "Entering add_active_range(%d, %#lx, %#lx) " 3945 "%d entries of %d used\n", 3946 nid, start_pfn, end_pfn, 3947 nr_nodemap_entries, MAX_ACTIVE_REGIONS); 3948 3949 mminit_validate_memmodel_limits(&start_pfn, &end_pfn); 3950 3951 /* Merge with existing active regions if possible */ 3952 for (i = 0; i < nr_nodemap_entries; i++) { 3953 if (early_node_map[i].nid != nid) 3954 continue; 3955 3956 /* Skip if an existing region covers this new one */ 3957 if (start_pfn >= early_node_map[i].start_pfn && 3958 end_pfn <= early_node_map[i].end_pfn) 3959 return; 3960 3961 /* Merge forward if suitable */ 3962 if (start_pfn <= early_node_map[i].end_pfn && 3963 end_pfn > early_node_map[i].end_pfn) { 3964 early_node_map[i].end_pfn = end_pfn; 3965 return; 3966 } 3967 3968 /* Merge backward if suitable */ 3969 if (start_pfn < early_node_map[i].end_pfn && 3970 end_pfn >= early_node_map[i].start_pfn) { 3971 early_node_map[i].start_pfn = start_pfn; 3972 return; 3973 } 3974 } 3975 3976 /* Check that early_node_map is large enough */ 3977 if (i >= MAX_ACTIVE_REGIONS) { 3978 printk(KERN_CRIT "More than %d memory regions, truncating\n", 3979 MAX_ACTIVE_REGIONS); 3980 return; 3981 } 3982 3983 early_node_map[i].nid = nid; 3984 early_node_map[i].start_pfn = start_pfn; 3985 early_node_map[i].end_pfn = end_pfn; 3986 nr_nodemap_entries = i + 1; 3987} 3988 3989/** 3990 * remove_active_range - Shrink an existing registered range of PFNs 3991 * @nid: The node id the range is on that should be shrunk 3992 * @start_pfn: The new PFN of the range 3993 * @end_pfn: The new PFN of the range 3994 * 3995 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node. 3996 * The map is kept near the end physical page range that has already been 3997 * registered. This function allows an arch to shrink an existing registered 3998 * range. 3999 */ 4000void __init remove_active_range(unsigned int nid, unsigned long start_pfn, 4001 unsigned long end_pfn) 4002{ 4003 int i, j; 4004 int removed = 0; 4005 4006 printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n", 4007 nid, start_pfn, end_pfn); 4008 4009 /* Find the old active region end and shrink */ 4010 for_each_active_range_index_in_nid(i, nid) { 4011 if (early_node_map[i].start_pfn >= start_pfn && 4012 early_node_map[i].end_pfn <= end_pfn) { 4013 /* clear it */ 4014 early_node_map[i].start_pfn = 0; 4015 early_node_map[i].end_pfn = 0; 4016 removed = 1; 4017 continue; 4018 } 4019 if (early_node_map[i].start_pfn < start_pfn && 4020 early_node_map[i].end_pfn > start_pfn) { 4021 unsigned long temp_end_pfn = early_node_map[i].end_pfn; 4022 early_node_map[i].end_pfn = start_pfn; 4023 if (temp_end_pfn > end_pfn) 4024 add_active_range(nid, end_pfn, temp_end_pfn); 4025 continue; 4026 } 4027 if (early_node_map[i].start_pfn >= start_pfn && 4028 early_node_map[i].end_pfn > end_pfn && 4029 early_node_map[i].start_pfn < end_pfn) { 4030 early_node_map[i].start_pfn = end_pfn; 4031 continue; 4032 } 4033 } 4034 4035 if (!removed) 4036 return; 4037 4038 /* remove the blank ones */ 4039 for (i = nr_nodemap_entries - 1; i > 0; i--) { 4040 if (early_node_map[i].nid != nid) 4041 continue; 4042 if (early_node_map[i].end_pfn) 4043 continue; 4044 /* we found it, get rid of it */ 4045 for (j = i; j < nr_nodemap_entries - 1; j++) 4046 memcpy(&early_node_map[j], &early_node_map[j+1], 4047 sizeof(early_node_map[j])); 4048 j = nr_nodemap_entries - 1; 4049 memset(&early_node_map[j], 0, sizeof(early_node_map[j])); 4050 nr_nodemap_entries--; 4051 } 4052} 4053 4054/** 4055 * remove_all_active_ranges - Remove all currently registered regions 4056 * 4057 * During discovery, it may be found that a table like SRAT is invalid 4058 * and an alternative discovery method must be used. This function removes 4059 * all currently registered regions. 4060 */ 4061void __init remove_all_active_ranges(void) 4062{ 4063 memset(early_node_map, 0, sizeof(early_node_map)); 4064 nr_nodemap_entries = 0; 4065} 4066 4067/* Compare two active node_active_regions */ 4068static int __init cmp_node_active_region(const void *a, const void *b) 4069{ 4070 struct node_active_region *arange = (struct node_active_region *)a; 4071 struct node_active_region *brange = (struct node_active_region *)b; 4072 4073 /* Done this way to avoid overflows */ 4074 if (arange->start_pfn > brange->start_pfn) 4075 return 1; 4076 if (arange->start_pfn < brange->start_pfn) 4077 return -1; 4078 4079 return 0; 4080} 4081 4082/* sort the node_map by start_pfn */ 4083static void __init sort_node_map(void) 4084{ 4085 sort(early_node_map, (size_t)nr_nodemap_entries, 4086 sizeof(struct node_active_region), 4087 cmp_node_active_region, NULL); 4088} 4089 4090/* Find the lowest pfn for a node */ 4091static unsigned long __init find_min_pfn_for_node(int nid) 4092{ 4093 int i; 4094 unsigned long min_pfn = ULONG_MAX; 4095 4096 /* Assuming a sorted map, the first range found has the starting pfn */ 4097 for_each_active_range_index_in_nid(i, nid) 4098 min_pfn = min(min_pfn, early_node_map[i].start_pfn); 4099 4100 if (min_pfn == ULONG_MAX) { 4101 printk(KERN_WARNING 4102 "Could not find start_pfn for node %d\n", nid); 4103 return 0; 4104 } 4105 4106 return min_pfn; 4107} 4108 4109/** 4110 * find_min_pfn_with_active_regions - Find the minimum PFN registered 4111 * 4112 * It returns the minimum PFN based on information provided via 4113 * add_active_range(). 4114 */ 4115unsigned long __init find_min_pfn_with_active_regions(void) 4116{ 4117 return find_min_pfn_for_node(MAX_NUMNODES); 4118} 4119 4120/* 4121 * early_calculate_totalpages() 4122 * Sum pages in active regions for movable zone. 4123 * Populate N_HIGH_MEMORY for calculating usable_nodes. 4124 */ 4125static unsigned long __init early_calculate_totalpages(void) 4126{ 4127 int i; 4128 unsigned long totalpages = 0; 4129 4130 for (i = 0; i < nr_nodemap_entries; i++) { 4131 unsigned long pages = early_node_map[i].end_pfn - 4132 early_node_map[i].start_pfn; 4133 totalpages += pages; 4134 if (pages) 4135 node_set_state(early_node_map[i].nid, N_HIGH_MEMORY); 4136 } 4137 return totalpages; 4138} 4139 4140/* 4141 * Find the PFN the Movable zone begins in each node. Kernel memory 4142 * is spread evenly between nodes as long as the nodes have enough 4143 * memory. When they don't, some nodes will have more kernelcore than 4144 * others 4145 */ 4146static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn) 4147{ 4148 int i, nid; 4149 unsigned long usable_startpfn; 4150 unsigned long kernelcore_node, kernelcore_remaining; 4151 /* save the state before borrow the nodemask */ 4152 nodemask_t saved_node_state = node_states[N_HIGH_MEMORY]; 4153 unsigned long totalpages = early_calculate_totalpages(); 4154 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]); 4155 4156 /* 4157 * If movablecore was specified, calculate what size of 4158 * kernelcore that corresponds so that memory usable for 4159 * any allocation type is evenly spread. If both kernelcore 4160 * and movablecore are specified, then the value of kernelcore 4161 * will be used for required_kernelcore if it's greater than 4162 * what movablecore would have allowed. 4163 */ 4164 if (required_movablecore) { 4165 unsigned long corepages; 4166 4167 /* 4168 * Round-up so that ZONE_MOVABLE is at least as large as what 4169 * was requested by the user 4170 */ 4171 required_movablecore = 4172 roundup(required_movablecore, MAX_ORDER_NR_PAGES); 4173 corepages = totalpages - required_movablecore; 4174 4175 required_kernelcore = max(required_kernelcore, corepages); 4176 } 4177 4178 /* If kernelcore was not specified, there is no ZONE_MOVABLE */ 4179 if (!required_kernelcore) 4180 goto out; 4181 4182 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ 4183 find_usable_zone_for_movable(); 4184 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; 4185 4186restart: 4187 /* Spread kernelcore memory as evenly as possible throughout nodes */ 4188 kernelcore_node = required_kernelcore / usable_nodes; 4189 for_each_node_state(nid, N_HIGH_MEMORY) { 4190 /* 4191 * Recalculate kernelcore_node if the division per node 4192 * now exceeds what is necessary to satisfy the requested 4193 * amount of memory for the kernel 4194 */ 4195 if (required_kernelcore < kernelcore_node) 4196 kernelcore_node = required_kernelcore / usable_nodes; 4197 4198 /* 4199 * As the map is walked, we track how much memory is usable 4200 * by the kernel using kernelcore_remaining. When it is 4201 * 0, the rest of the node is usable by ZONE_MOVABLE 4202 */ 4203 kernelcore_remaining = kernelcore_node; 4204 4205 /* Go through each range of PFNs within this node */ 4206 for_each_active_range_index_in_nid(i, nid) { 4207 unsigned long start_pfn, end_pfn; 4208 unsigned long size_pages; 4209 4210 start_pfn = max(early_node_map[i].start_pfn, 4211 zone_movable_pfn[nid]); 4212 end_pfn = early_node_map[i].end_pfn; 4213 if (start_pfn >= end_pfn) 4214 continue; 4215 4216 /* Account for what is only usable for kernelcore */ 4217 if (start_pfn < usable_startpfn) { 4218 unsigned long kernel_pages; 4219 kernel_pages = min(end_pfn, usable_startpfn) 4220 - start_pfn; 4221 4222 kernelcore_remaining -= min(kernel_pages, 4223 kernelcore_remaining); 4224 required_kernelcore -= min(kernel_pages, 4225 required_kernelcore); 4226 4227 /* Continue if range is now fully accounted */ 4228 if (end_pfn <= usable_startpfn) { 4229 4230 /* 4231 * Push zone_movable_pfn to the end so 4232 * that if we have to rebalance 4233 * kernelcore across nodes, we will 4234 * not double account here 4235 */ 4236 zone_movable_pfn[nid] = end_pfn; 4237 continue; 4238 } 4239 start_pfn = usable_startpfn; 4240 } 4241 4242 /* 4243 * The usable PFN range for ZONE_MOVABLE is from 4244 * start_pfn->end_pfn. Calculate size_pages as the 4245 * number of pages used as kernelcore 4246 */ 4247 size_pages = end_pfn - start_pfn; 4248 if (size_pages > kernelcore_remaining) 4249 size_pages = kernelcore_remaining; 4250 zone_movable_pfn[nid] = start_pfn + size_pages; 4251 4252 /* 4253 * Some kernelcore has been met, update counts and 4254 * break if the kernelcore for this node has been 4255 * satisified 4256 */ 4257 required_kernelcore -= min(required_kernelcore, 4258 size_pages); 4259 kernelcore_remaining -= size_pages; 4260 if (!kernelcore_remaining) 4261 break; 4262 } 4263 } 4264 4265 /* 4266 * If there is still required_kernelcore, we do another pass with one 4267 * less node in the count. This will push zone_movable_pfn[nid] further 4268 * along on the nodes that still have memory until kernelcore is 4269 * satisified 4270 */ 4271 usable_nodes--; 4272 if (usable_nodes && required_kernelcore > usable_nodes) 4273 goto restart; 4274 4275 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ 4276 for (nid = 0; nid < MAX_NUMNODES; nid++) 4277 zone_movable_pfn[nid] = 4278 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); 4279 4280out: 4281 /* restore the node_state */ 4282 node_states[N_HIGH_MEMORY] = saved_node_state; 4283} 4284 4285/* Any regular memory on that node ? */ 4286static void check_for_regular_memory(pg_data_t *pgdat) 4287{ 4288#ifdef CONFIG_HIGHMEM 4289 enum zone_type zone_type; 4290 4291 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) { 4292 struct zone *zone = &pgdat->node_zones[zone_type]; 4293 if (zone->present_pages) 4294 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY); 4295 } 4296#endif 4297} 4298 4299/** 4300 * free_area_init_nodes - Initialise all pg_data_t and zone data 4301 * @max_zone_pfn: an array of max PFNs for each zone 4302 * 4303 * This will call free_area_init_node() for each active node in the system. 4304 * Using the page ranges provided by add_active_range(), the size of each 4305 * zone in each node and their holes is calculated. If the maximum PFN 4306 * between two adjacent zones match, it is assumed that the zone is empty. 4307 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed 4308 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone 4309 * starts where the previous one ended. For example, ZONE_DMA32 starts 4310 * at arch_max_dma_pfn. 4311 */ 4312void __init free_area_init_nodes(unsigned long *max_zone_pfn) 4313{ 4314 unsigned long nid; 4315 int i; 4316 4317 /* Sort early_node_map as initialisation assumes it is sorted */ 4318 sort_node_map(); 4319 4320 /* Record where the zone boundaries are */ 4321 memset(arch_zone_lowest_possible_pfn, 0, 4322 sizeof(arch_zone_lowest_possible_pfn)); 4323 memset(arch_zone_highest_possible_pfn, 0, 4324 sizeof(arch_zone_highest_possible_pfn)); 4325 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); 4326 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; 4327 for (i = 1; i < MAX_NR_ZONES; i++) { 4328 if (i == ZONE_MOVABLE) 4329 continue; 4330 arch_zone_lowest_possible_pfn[i] = 4331 arch_zone_highest_possible_pfn[i-1]; 4332 arch_zone_highest_possible_pfn[i] = 4333 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); 4334 } 4335 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0; 4336 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0; 4337 4338 /* Find the PFNs that ZONE_MOVABLE begins at in each node */ 4339 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); 4340 find_zone_movable_pfns_for_nodes(zone_movable_pfn); 4341 4342 /* Print out the zone ranges */ 4343 printk("Zone PFN ranges:\n"); 4344 for (i = 0; i < MAX_NR_ZONES; i++) { 4345 if (i == ZONE_MOVABLE) 4346 continue; 4347 printk(" %-8s %0#10lx -> %0#10lx\n", 4348 zone_names[i], 4349 arch_zone_lowest_possible_pfn[i], 4350 arch_zone_highest_possible_pfn[i]); 4351 } 4352 4353 /* Print out the PFNs ZONE_MOVABLE begins at in each node */ 4354 printk("Movable zone start PFN for each node\n"); 4355 for (i = 0; i < MAX_NUMNODES; i++) { 4356 if (zone_movable_pfn[i]) 4357 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]); 4358 } 4359 4360 /* Print out the early_node_map[] */ 4361 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries); 4362 for (i = 0; i < nr_nodemap_entries; i++) 4363 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid, 4364 early_node_map[i].start_pfn, 4365 early_node_map[i].end_pfn); 4366 4367 /* Initialise every node */ 4368 mminit_verify_pageflags_layout(); 4369 setup_nr_node_ids(); 4370 for_each_online_node(nid) { 4371 pg_data_t *pgdat = NODE_DATA(nid); 4372 free_area_init_node(nid, NULL, 4373 find_min_pfn_for_node(nid), NULL); 4374 4375 /* Any memory on that node */ 4376 if (pgdat->node_present_pages) 4377 node_set_state(nid, N_HIGH_MEMORY); 4378 check_for_regular_memory(pgdat); 4379 } 4380} 4381 4382static int __init cmdline_parse_core(char *p, unsigned long *core) 4383{ 4384 unsigned long long coremem; 4385 if (!p) 4386 return -EINVAL; 4387 4388 coremem = memparse(p, &p); 4389 *core = coremem >> PAGE_SHIFT; 4390 4391 /* Paranoid check that UL is enough for the coremem value */ 4392 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); 4393 4394 return 0; 4395} 4396 4397/* 4398 * kernelcore=size sets the amount of memory for use for allocations that 4399 * cannot be reclaimed or migrated. 4400 */ 4401static int __init cmdline_parse_kernelcore(char *p) 4402{ 4403 return cmdline_parse_core(p, &required_kernelcore); 4404} 4405 4406/* 4407 * movablecore=size sets the amount of memory for use for allocations that 4408 * can be reclaimed or migrated. 4409 */ 4410static int __init cmdline_parse_movablecore(char *p) 4411{ 4412 return cmdline_parse_core(p, &required_movablecore); 4413} 4414 4415early_param("kernelcore", cmdline_parse_kernelcore); 4416early_param("movablecore", cmdline_parse_movablecore); 4417 4418#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 4419 4420/** 4421 * set_dma_reserve - set the specified number of pages reserved in the first zone 4422 * @new_dma_reserve: The number of pages to mark reserved 4423 * 4424 * The per-cpu batchsize and zone watermarks are determined by present_pages. 4425 * In the DMA zone, a significant percentage may be consumed by kernel image 4426 * and other unfreeable allocations which can skew the watermarks badly. This 4427 * function may optionally be used to account for unfreeable pages in the 4428 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and 4429 * smaller per-cpu batchsize. 4430 */ 4431void __init set_dma_reserve(unsigned long new_dma_reserve) 4432{ 4433 dma_reserve = new_dma_reserve; 4434} 4435 4436#ifndef CONFIG_NEED_MULTIPLE_NODES 4437struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] }; 4438EXPORT_SYMBOL(contig_page_data); 4439#endif 4440 4441void __init free_area_init(unsigned long *zones_size) 4442{ 4443 free_area_init_node(0, zones_size, 4444 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 4445} 4446 4447static int page_alloc_cpu_notify(struct notifier_block *self, 4448 unsigned long action, void *hcpu) 4449{ 4450 int cpu = (unsigned long)hcpu; 4451 4452 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { 4453 drain_pages(cpu); 4454 4455 /* 4456 * Spill the event counters of the dead processor 4457 * into the current processors event counters. 4458 * This artificially elevates the count of the current 4459 * processor. 4460 */ 4461 vm_events_fold_cpu(cpu); 4462 4463 /* 4464 * Zero the differential counters of the dead processor 4465 * so that the vm statistics are consistent. 4466 * 4467 * This is only okay since the processor is dead and cannot 4468 * race with what we are doing. 4469 */ 4470 refresh_cpu_vm_stats(cpu); 4471 } 4472 return NOTIFY_OK; 4473} 4474 4475void __init page_alloc_init(void) 4476{ 4477 hotcpu_notifier(page_alloc_cpu_notify, 0); 4478} 4479 4480/* 4481 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio 4482 * or min_free_kbytes changes. 4483 */ 4484static void calculate_totalreserve_pages(void) 4485{ 4486 struct pglist_data *pgdat; 4487 unsigned long reserve_pages = 0; 4488 enum zone_type i, j; 4489 4490 for_each_online_pgdat(pgdat) { 4491 for (i = 0; i < MAX_NR_ZONES; i++) { 4492 struct zone *zone = pgdat->node_zones + i; 4493 unsigned long max = 0; 4494 4495 /* Find valid and maximum lowmem_reserve in the zone */ 4496 for (j = i; j < MAX_NR_ZONES; j++) { 4497 if (zone->lowmem_reserve[j] > max) 4498 max = zone->lowmem_reserve[j]; 4499 } 4500 4501 /* we treat the high watermark as reserved pages. */ 4502 max += high_wmark_pages(zone); 4503 4504 if (max > zone->present_pages) 4505 max = zone->present_pages; 4506 reserve_pages += max; 4507 } 4508 } 4509 totalreserve_pages = reserve_pages; 4510} 4511 4512/* 4513 * setup_per_zone_lowmem_reserve - called whenever 4514 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 4515 * has a correct pages reserved value, so an adequate number of 4516 * pages are left in the zone after a successful __alloc_pages(). 4517 */ 4518static void setup_per_zone_lowmem_reserve(void) 4519{ 4520 struct pglist_data *pgdat; 4521 enum zone_type j, idx; 4522 4523 for_each_online_pgdat(pgdat) { 4524 for (j = 0; j < MAX_NR_ZONES; j++) { 4525 struct zone *zone = pgdat->node_zones + j; 4526 unsigned long present_pages = zone->present_pages; 4527 4528 zone->lowmem_reserve[j] = 0; 4529 4530 idx = j; 4531 while (idx) { 4532 struct zone *lower_zone; 4533 4534 idx--; 4535 4536 if (sysctl_lowmem_reserve_ratio[idx] < 1) 4537 sysctl_lowmem_reserve_ratio[idx] = 1; 4538 4539 lower_zone = pgdat->node_zones + idx; 4540 lower_zone->lowmem_reserve[j] = present_pages / 4541 sysctl_lowmem_reserve_ratio[idx]; 4542 present_pages += lower_zone->present_pages; 4543 } 4544 } 4545 } 4546 4547 /* update totalreserve_pages */ 4548 calculate_totalreserve_pages(); 4549} 4550 4551/** 4552 * setup_per_zone_wmarks - called when min_free_kbytes changes 4553 * or when memory is hot-{added|removed} 4554 * 4555 * Ensures that the watermark[min,low,high] values for each zone are set 4556 * correctly with respect to min_free_kbytes. 4557 */ 4558void setup_per_zone_wmarks(void) 4559{ 4560 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 4561 unsigned long lowmem_pages = 0; 4562 struct zone *zone; 4563 unsigned long flags; 4564 4565 /* Calculate total number of !ZONE_HIGHMEM pages */ 4566 for_each_zone(zone) { 4567 if (!is_highmem(zone)) 4568 lowmem_pages += zone->present_pages; 4569 } 4570 4571 for_each_zone(zone) { 4572 u64 tmp; 4573 4574 spin_lock_irqsave(&zone->lock, flags); 4575 tmp = (u64)pages_min * zone->present_pages; 4576 do_div(tmp, lowmem_pages); 4577 if (is_highmem(zone)) { 4578 /* 4579 * __GFP_HIGH and PF_MEMALLOC allocations usually don't 4580 * need highmem pages, so cap pages_min to a small 4581 * value here. 4582 * 4583 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN) 4584 * deltas controls asynch page reclaim, and so should 4585 * not be capped for highmem. 4586 */ 4587 int min_pages; 4588 4589 min_pages = zone->present_pages / 1024; 4590 if (min_pages < SWAP_CLUSTER_MAX) 4591 min_pages = SWAP_CLUSTER_MAX; 4592 if (min_pages > 128) 4593 min_pages = 128; 4594 zone->watermark[WMARK_MIN] = min_pages; 4595 } else { 4596 /* 4597 * If it's a lowmem zone, reserve a number of pages 4598 * proportionate to the zone's size. 4599 */ 4600 zone->watermark[WMARK_MIN] = tmp; 4601 } 4602 4603 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2); 4604 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1); 4605 setup_zone_migrate_reserve(zone); 4606 spin_unlock_irqrestore(&zone->lock, flags); 4607 } 4608 4609 /* update totalreserve_pages */ 4610 calculate_totalreserve_pages(); 4611} 4612 4613/* 4614 * The inactive anon list should be small enough that the VM never has to 4615 * do too much work, but large enough that each inactive page has a chance 4616 * to be referenced again before it is swapped out. 4617 * 4618 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to 4619 * INACTIVE_ANON pages on this zone's LRU, maintained by the 4620 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of 4621 * the anonymous pages are kept on the inactive list. 4622 * 4623 * total target max 4624 * memory ratio inactive anon 4625 * ------------------------------------- 4626 * 10MB 1 5MB 4627 * 100MB 1 50MB 4628 * 1GB 3 250MB 4629 * 10GB 10 0.9GB 4630 * 100GB 31 3GB 4631 * 1TB 101 10GB 4632 * 10TB 320 32GB 4633 */ 4634void calculate_zone_inactive_ratio(struct zone *zone) 4635{ 4636 unsigned int gb, ratio; 4637 4638 /* Zone size in gigabytes */ 4639 gb = zone->present_pages >> (30 - PAGE_SHIFT); 4640 if (gb) 4641 ratio = int_sqrt(10 * gb); 4642 else 4643 ratio = 1; 4644 4645 zone->inactive_ratio = ratio; 4646} 4647 4648static void __init setup_per_zone_inactive_ratio(void) 4649{ 4650 struct zone *zone; 4651 4652 for_each_zone(zone) 4653 calculate_zone_inactive_ratio(zone); 4654} 4655 4656/* 4657 * Initialise min_free_kbytes. 4658 * 4659 * For small machines we want it small (128k min). For large machines 4660 * we want it large (64MB max). But it is not linear, because network 4661 * bandwidth does not increase linearly with machine size. We use 4662 * 4663 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 4664 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 4665 * 4666 * which yields 4667 * 4668 * 16MB: 512k 4669 * 32MB: 724k 4670 * 64MB: 1024k 4671 * 128MB: 1448k 4672 * 256MB: 2048k 4673 * 512MB: 2896k 4674 * 1024MB: 4096k 4675 * 2048MB: 5792k 4676 * 4096MB: 8192k 4677 * 8192MB: 11584k 4678 * 16384MB: 16384k 4679 */ 4680static int __init init_per_zone_wmark_min(void) 4681{ 4682 unsigned long lowmem_kbytes; 4683 4684 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 4685 4686 min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 4687 if (min_free_kbytes < 128) 4688 min_free_kbytes = 128; 4689 if (min_free_kbytes > 65536) 4690 min_free_kbytes = 65536; 4691 setup_per_zone_wmarks(); 4692 setup_per_zone_lowmem_reserve(); 4693 setup_per_zone_inactive_ratio(); 4694 return 0; 4695} 4696module_init(init_per_zone_wmark_min) 4697 4698/* 4699 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 4700 * that we can call two helper functions whenever min_free_kbytes 4701 * changes. 4702 */ 4703int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 4704 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4705{ 4706 proc_dointvec(table, write, file, buffer, length, ppos); 4707 if (write) 4708 setup_per_zone_wmarks(); 4709 return 0; 4710} 4711 4712#ifdef CONFIG_NUMA 4713int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, 4714 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4715{ 4716 struct zone *zone; 4717 int rc; 4718 4719 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4720 if (rc) 4721 return rc; 4722 4723 for_each_zone(zone) 4724 zone->min_unmapped_pages = (zone->present_pages * 4725 sysctl_min_unmapped_ratio) / 100; 4726 return 0; 4727} 4728 4729int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write, 4730 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4731{ 4732 struct zone *zone; 4733 int rc; 4734 4735 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4736 if (rc) 4737 return rc; 4738 4739 for_each_zone(zone) 4740 zone->min_slab_pages = (zone->present_pages * 4741 sysctl_min_slab_ratio) / 100; 4742 return 0; 4743} 4744#endif 4745 4746/* 4747 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 4748 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 4749 * whenever sysctl_lowmem_reserve_ratio changes. 4750 * 4751 * The reserve ratio obviously has absolutely no relation with the 4752 * minimum watermarks. The lowmem reserve ratio can only make sense 4753 * if in function of the boot time zone sizes. 4754 */ 4755int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, 4756 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4757{ 4758 proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4759 setup_per_zone_lowmem_reserve(); 4760 return 0; 4761} 4762 4763/* 4764 * percpu_pagelist_fraction - changes the pcp->high for each zone on each 4765 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist 4766 * can have before it gets flushed back to buddy allocator. 4767 */ 4768 4769int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, 4770 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4771{ 4772 struct zone *zone; 4773 unsigned int cpu; 4774 int ret; 4775 4776 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4777 if (!write || (ret == -EINVAL)) 4778 return ret; 4779 for_each_populated_zone(zone) { 4780 for_each_online_cpu(cpu) { 4781 unsigned long high; 4782 high = zone->present_pages / percpu_pagelist_fraction; 4783 setup_pagelist_highmark(zone_pcp(zone, cpu), high); 4784 } 4785 } 4786 return 0; 4787} 4788 4789int hashdist = HASHDIST_DEFAULT; 4790 4791#ifdef CONFIG_NUMA 4792static int __init set_hashdist(char *str) 4793{ 4794 if (!str) 4795 return 0; 4796 hashdist = simple_strtoul(str, &str, 0); 4797 return 1; 4798} 4799__setup("hashdist=", set_hashdist); 4800#endif 4801 4802/* 4803 * allocate a large system hash table from bootmem 4804 * - it is assumed that the hash table must contain an exact power-of-2 4805 * quantity of entries 4806 * - limit is the number of hash buckets, not the total allocation size 4807 */ 4808void *__init alloc_large_system_hash(const char *tablename, 4809 unsigned long bucketsize, 4810 unsigned long numentries, 4811 int scale, 4812 int flags, 4813 unsigned int *_hash_shift, 4814 unsigned int *_hash_mask, 4815 unsigned long limit) 4816{ 4817 unsigned long long max = limit; 4818 unsigned long log2qty, size; 4819 void *table = NULL; 4820 4821 /* allow the kernel cmdline to have a say */ 4822 if (!numentries) { 4823 /* round applicable memory size up to nearest megabyte */ 4824 numentries = nr_kernel_pages; 4825 numentries += (1UL << (20 - PAGE_SHIFT)) - 1; 4826 numentries >>= 20 - PAGE_SHIFT; 4827 numentries <<= 20 - PAGE_SHIFT; 4828 4829 /* limit to 1 bucket per 2^scale bytes of low memory */ 4830 if (scale > PAGE_SHIFT) 4831 numentries >>= (scale - PAGE_SHIFT); 4832 else 4833 numentries <<= (PAGE_SHIFT - scale); 4834 4835 /* Make sure we've got at least a 0-order allocation.. */ 4836 if (unlikely(flags & HASH_SMALL)) { 4837 /* Makes no sense without HASH_EARLY */ 4838 WARN_ON(!(flags & HASH_EARLY)); 4839 if (!(numentries >> *_hash_shift)) { 4840 numentries = 1UL << *_hash_shift; 4841 BUG_ON(!numentries); 4842 } 4843 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE)) 4844 numentries = PAGE_SIZE / bucketsize; 4845 } 4846 numentries = roundup_pow_of_two(numentries); 4847 4848 /* limit allocation size to 1/16 total memory by default */ 4849 if (max == 0) { 4850 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 4851 do_div(max, bucketsize); 4852 } 4853 4854 if (numentries > max) 4855 numentries = max; 4856 4857 log2qty = ilog2(numentries); 4858 4859 do { 4860 size = bucketsize << log2qty; 4861 if (flags & HASH_EARLY) 4862 table = alloc_bootmem_nopanic(size); 4863 else if (hashdist) 4864 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 4865 else { 4866 /* 4867 * If bucketsize is not a power-of-two, we may free 4868 * some pages at the end of hash table which 4869 * alloc_pages_exact() automatically does 4870 */ 4871 if (get_order(size) < MAX_ORDER) { 4872 table = alloc_pages_exact(size, GFP_ATOMIC); 4873 kmemleak_alloc(table, size, 1, GFP_ATOMIC); 4874 } 4875 } 4876 } while (!table && size > PAGE_SIZE && --log2qty); 4877 4878 if (!table) 4879 panic("Failed to allocate %s hash table\n", tablename); 4880 4881 printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n", 4882 tablename, 4883 (1U << log2qty), 4884 ilog2(size) - PAGE_SHIFT, 4885 size); 4886 4887 if (_hash_shift) 4888 *_hash_shift = log2qty; 4889 if (_hash_mask) 4890 *_hash_mask = (1 << log2qty) - 1; 4891 4892 return table; 4893} 4894 4895/* Return a pointer to the bitmap storing bits affecting a block of pages */ 4896static inline unsigned long *get_pageblock_bitmap(struct zone *zone, 4897 unsigned long pfn) 4898{ 4899#ifdef CONFIG_SPARSEMEM 4900 return __pfn_to_section(pfn)->pageblock_flags; 4901#else 4902 return zone->pageblock_flags; 4903#endif /* CONFIG_SPARSEMEM */ 4904} 4905 4906static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) 4907{ 4908#ifdef CONFIG_SPARSEMEM 4909 pfn &= (PAGES_PER_SECTION-1); 4910 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 4911#else 4912 pfn = pfn - zone->zone_start_pfn; 4913 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 4914#endif /* CONFIG_SPARSEMEM */ 4915} 4916 4917/** 4918 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages 4919 * @page: The page within the block of interest 4920 * @start_bitidx: The first bit of interest to retrieve 4921 * @end_bitidx: The last bit of interest 4922 * returns pageblock_bits flags 4923 */ 4924unsigned long get_pageblock_flags_group(struct page *page, 4925 int start_bitidx, int end_bitidx) 4926{ 4927 struct zone *zone; 4928 unsigned long *bitmap; 4929 unsigned long pfn, bitidx; 4930 unsigned long flags = 0; 4931 unsigned long value = 1; 4932 4933 zone = page_zone(page); 4934 pfn = page_to_pfn(page); 4935 bitmap = get_pageblock_bitmap(zone, pfn); 4936 bitidx = pfn_to_bitidx(zone, pfn); 4937 4938 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 4939 if (test_bit(bitidx + start_bitidx, bitmap)) 4940 flags |= value; 4941 4942 return flags; 4943} 4944 4945/** 4946 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages 4947 * @page: The page within the block of interest 4948 * @start_bitidx: The first bit of interest 4949 * @end_bitidx: The last bit of interest 4950 * @flags: The flags to set 4951 */ 4952void set_pageblock_flags_group(struct page *page, unsigned long flags, 4953 int start_bitidx, int end_bitidx) 4954{ 4955 struct zone *zone; 4956 unsigned long *bitmap; 4957 unsigned long pfn, bitidx; 4958 unsigned long value = 1; 4959 4960 zone = page_zone(page); 4961 pfn = page_to_pfn(page); 4962 bitmap = get_pageblock_bitmap(zone, pfn); 4963 bitidx = pfn_to_bitidx(zone, pfn); 4964 VM_BUG_ON(pfn < zone->zone_start_pfn); 4965 VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages); 4966 4967 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 4968 if (flags & value) 4969 __set_bit(bitidx + start_bitidx, bitmap); 4970 else 4971 __clear_bit(bitidx + start_bitidx, bitmap); 4972} 4973 4974/* 4975 * This is designed as sub function...plz see page_isolation.c also. 4976 * set/clear page block's type to be ISOLATE. 4977 * page allocater never alloc memory from ISOLATE block. 4978 */ 4979 4980int set_migratetype_isolate(struct page *page) 4981{ 4982 struct zone *zone; 4983 unsigned long flags; 4984 int ret = -EBUSY; 4985 int zone_idx; 4986 4987 zone = page_zone(page); 4988 zone_idx = zone_idx(zone); 4989 spin_lock_irqsave(&zone->lock, flags); 4990 /* 4991 * In future, more migrate types will be able to be isolation target. 4992 */ 4993 if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE && 4994 zone_idx != ZONE_MOVABLE) 4995 goto out; 4996 set_pageblock_migratetype(page, MIGRATE_ISOLATE); 4997 move_freepages_block(zone, page, MIGRATE_ISOLATE); 4998 ret = 0; 4999out: 5000 spin_unlock_irqrestore(&zone->lock, flags); 5001 if (!ret) 5002 drain_all_pages(); 5003 return ret; 5004} 5005 5006void unset_migratetype_isolate(struct page *page) 5007{ 5008 struct zone *zone; 5009 unsigned long flags; 5010 zone = page_zone(page); 5011 spin_lock_irqsave(&zone->lock, flags); 5012 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE) 5013 goto out; 5014 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 5015 move_freepages_block(zone, page, MIGRATE_MOVABLE); 5016out: 5017 spin_unlock_irqrestore(&zone->lock, flags); 5018} 5019 5020#ifdef CONFIG_MEMORY_HOTREMOVE 5021/* 5022 * All pages in the range must be isolated before calling this. 5023 */ 5024void 5025__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) 5026{ 5027 struct page *page; 5028 struct zone *zone; 5029 int order, i; 5030 unsigned long pfn; 5031 unsigned long flags; 5032 /* find the first valid pfn */ 5033 for (pfn = start_pfn; pfn < end_pfn; pfn++) 5034 if (pfn_valid(pfn)) 5035 break; 5036 if (pfn == end_pfn) 5037 return; 5038 zone = page_zone(pfn_to_page(pfn)); 5039 spin_lock_irqsave(&zone->lock, flags); 5040 pfn = start_pfn; 5041 while (pfn < end_pfn) { 5042 if (!pfn_valid(pfn)) { 5043 pfn++; 5044 continue; 5045 } 5046 page = pfn_to_page(pfn); 5047 BUG_ON(page_count(page)); 5048 BUG_ON(!PageBuddy(page)); 5049 order = page_order(page); 5050#ifdef CONFIG_DEBUG_VM 5051 printk(KERN_INFO "remove from free list %lx %d %lx\n", 5052 pfn, 1 << order, end_pfn); 5053#endif 5054 list_del(&page->lru); 5055 rmv_page_order(page); 5056 zone->free_area[order].nr_free--; 5057 __mod_zone_page_state(zone, NR_FREE_PAGES, 5058 - (1UL << order)); 5059 for (i = 0; i < (1 << order); i++) 5060 SetPageReserved((page+i)); 5061 pfn += (1 << order); 5062 } 5063 spin_unlock_irqrestore(&zone->lock, flags); 5064} 5065#endif 5066