page_alloc.c revision 112067f0905b2de862c607ee62411cf47d2fe5c4
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 52#include <asm/tlbflush.h> 53#include <asm/div64.h> 54#include "internal.h" 55 56/* 57 * Array of node states. 58 */ 59nodemask_t node_states[NR_NODE_STATES] __read_mostly = { 60 [N_POSSIBLE] = NODE_MASK_ALL, 61 [N_ONLINE] = { { [0] = 1UL } }, 62#ifndef CONFIG_NUMA 63 [N_NORMAL_MEMORY] = { { [0] = 1UL } }, 64#ifdef CONFIG_HIGHMEM 65 [N_HIGH_MEMORY] = { { [0] = 1UL } }, 66#endif 67 [N_CPU] = { { [0] = 1UL } }, 68#endif /* NUMA */ 69}; 70EXPORT_SYMBOL(node_states); 71 72unsigned long totalram_pages __read_mostly; 73unsigned long totalreserve_pages __read_mostly; 74unsigned long highest_memmap_pfn __read_mostly; 75int percpu_pagelist_fraction; 76gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; 77 78#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 79int pageblock_order __read_mostly; 80#endif 81 82static void __free_pages_ok(struct page *page, unsigned int order); 83 84/* 85 * results with 256, 32 in the lowmem_reserve sysctl: 86 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) 87 * 1G machine -> (16M dma, 784M normal, 224M high) 88 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA 89 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL 90 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA 91 * 92 * TBD: should special case ZONE_DMA32 machines here - in those we normally 93 * don't need any ZONE_NORMAL reservation 94 */ 95int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 96#ifdef CONFIG_ZONE_DMA 97 256, 98#endif 99#ifdef CONFIG_ZONE_DMA32 100 256, 101#endif 102#ifdef CONFIG_HIGHMEM 103 32, 104#endif 105 32, 106}; 107 108EXPORT_SYMBOL(totalram_pages); 109 110static char * const zone_names[MAX_NR_ZONES] = { 111#ifdef CONFIG_ZONE_DMA 112 "DMA", 113#endif 114#ifdef CONFIG_ZONE_DMA32 115 "DMA32", 116#endif 117 "Normal", 118#ifdef CONFIG_HIGHMEM 119 "HighMem", 120#endif 121 "Movable", 122}; 123 124int min_free_kbytes = 1024; 125 126unsigned long __meminitdata nr_kernel_pages; 127unsigned long __meminitdata nr_all_pages; 128static unsigned long __meminitdata dma_reserve; 129 130#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 131 /* 132 * MAX_ACTIVE_REGIONS determines the maximum number of distinct 133 * ranges of memory (RAM) that may be registered with add_active_range(). 134 * Ranges passed to add_active_range() will be merged if possible 135 * so the number of times add_active_range() can be called is 136 * related to the number of nodes and the number of holes 137 */ 138 #ifdef CONFIG_MAX_ACTIVE_REGIONS 139 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */ 140 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS 141 #else 142 #if MAX_NUMNODES >= 32 143 /* If there can be many nodes, allow up to 50 holes per node */ 144 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50) 145 #else 146 /* By default, allow up to 256 distinct regions */ 147 #define MAX_ACTIVE_REGIONS 256 148 #endif 149 #endif 150 151 static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS]; 152 static int __meminitdata nr_nodemap_entries; 153 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; 154 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; 155 static unsigned long __initdata required_kernelcore; 156 static unsigned long __initdata required_movablecore; 157 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES]; 158 159 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ 160 int movable_zone; 161 EXPORT_SYMBOL(movable_zone); 162#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 163 164#if MAX_NUMNODES > 1 165int nr_node_ids __read_mostly = MAX_NUMNODES; 166int nr_online_nodes __read_mostly = 1; 167EXPORT_SYMBOL(nr_node_ids); 168EXPORT_SYMBOL(nr_online_nodes); 169#endif 170 171int page_group_by_mobility_disabled __read_mostly; 172 173static void set_pageblock_migratetype(struct page *page, int migratetype) 174{ 175 176 if (unlikely(page_group_by_mobility_disabled)) 177 migratetype = MIGRATE_UNMOVABLE; 178 179 set_pageblock_flags_group(page, (unsigned long)migratetype, 180 PB_migrate, PB_migrate_end); 181} 182 183bool oom_killer_disabled __read_mostly; 184 185#ifdef CONFIG_DEBUG_VM 186static int page_outside_zone_boundaries(struct zone *zone, struct page *page) 187{ 188 int ret = 0; 189 unsigned seq; 190 unsigned long pfn = page_to_pfn(page); 191 192 do { 193 seq = zone_span_seqbegin(zone); 194 if (pfn >= zone->zone_start_pfn + zone->spanned_pages) 195 ret = 1; 196 else if (pfn < zone->zone_start_pfn) 197 ret = 1; 198 } while (zone_span_seqretry(zone, seq)); 199 200 return ret; 201} 202 203static int page_is_consistent(struct zone *zone, struct page *page) 204{ 205 if (!pfn_valid_within(page_to_pfn(page))) 206 return 0; 207 if (zone != page_zone(page)) 208 return 0; 209 210 return 1; 211} 212/* 213 * Temporary debugging check for pages not lying within a given zone. 214 */ 215static int bad_range(struct zone *zone, struct page *page) 216{ 217 if (page_outside_zone_boundaries(zone, page)) 218 return 1; 219 if (!page_is_consistent(zone, page)) 220 return 1; 221 222 return 0; 223} 224#else 225static inline int bad_range(struct zone *zone, struct page *page) 226{ 227 return 0; 228} 229#endif 230 231static void bad_page(struct page *page) 232{ 233 static unsigned long resume; 234 static unsigned long nr_shown; 235 static unsigned long nr_unshown; 236 237 /* 238 * Allow a burst of 60 reports, then keep quiet for that minute; 239 * or allow a steady drip of one report per second. 240 */ 241 if (nr_shown == 60) { 242 if (time_before(jiffies, resume)) { 243 nr_unshown++; 244 goto out; 245 } 246 if (nr_unshown) { 247 printk(KERN_ALERT 248 "BUG: Bad page state: %lu messages suppressed\n", 249 nr_unshown); 250 nr_unshown = 0; 251 } 252 nr_shown = 0; 253 } 254 if (nr_shown++ == 0) 255 resume = jiffies + 60 * HZ; 256 257 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n", 258 current->comm, page_to_pfn(page)); 259 printk(KERN_ALERT 260 "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n", 261 page, (void *)page->flags, page_count(page), 262 page_mapcount(page), page->mapping, page->index); 263 264 dump_stack(); 265out: 266 /* Leave bad fields for debug, except PageBuddy could make trouble */ 267 __ClearPageBuddy(page); 268 add_taint(TAINT_BAD_PAGE); 269} 270 271/* 272 * Higher-order pages are called "compound pages". They are structured thusly: 273 * 274 * The first PAGE_SIZE page is called the "head page". 275 * 276 * The remaining PAGE_SIZE pages are called "tail pages". 277 * 278 * All pages have PG_compound set. All pages have their ->private pointing at 279 * the head page (even the head page has this). 280 * 281 * The first tail page's ->lru.next holds the address of the compound page's 282 * put_page() function. Its ->lru.prev holds the order of allocation. 283 * This usage means that zero-order pages may not be compound. 284 */ 285 286static void free_compound_page(struct page *page) 287{ 288 __free_pages_ok(page, compound_order(page)); 289} 290 291void prep_compound_page(struct page *page, unsigned long order) 292{ 293 int i; 294 int nr_pages = 1 << order; 295 296 set_compound_page_dtor(page, free_compound_page); 297 set_compound_order(page, order); 298 __SetPageHead(page); 299 for (i = 1; i < nr_pages; i++) { 300 struct page *p = page + i; 301 302 __SetPageTail(p); 303 p->first_page = page; 304 } 305} 306 307static int destroy_compound_page(struct page *page, unsigned long order) 308{ 309 int i; 310 int nr_pages = 1 << order; 311 int bad = 0; 312 313 if (unlikely(compound_order(page) != order) || 314 unlikely(!PageHead(page))) { 315 bad_page(page); 316 bad++; 317 } 318 319 __ClearPageHead(page); 320 321 for (i = 1; i < nr_pages; i++) { 322 struct page *p = page + i; 323 324 if (unlikely(!PageTail(p) || (p->first_page != page))) { 325 bad_page(page); 326 bad++; 327 } 328 __ClearPageTail(p); 329 } 330 331 return bad; 332} 333 334static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) 335{ 336 int i; 337 338 /* 339 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO 340 * and __GFP_HIGHMEM from hard or soft interrupt context. 341 */ 342 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); 343 for (i = 0; i < (1 << order); i++) 344 clear_highpage(page + i); 345} 346 347static inline void set_page_order(struct page *page, int order) 348{ 349 set_page_private(page, order); 350 __SetPageBuddy(page); 351} 352 353static inline void rmv_page_order(struct page *page) 354{ 355 __ClearPageBuddy(page); 356 set_page_private(page, 0); 357} 358 359/* 360 * Locate the struct page for both the matching buddy in our 361 * pair (buddy1) and the combined O(n+1) page they form (page). 362 * 363 * 1) Any buddy B1 will have an order O twin B2 which satisfies 364 * the following equation: 365 * B2 = B1 ^ (1 << O) 366 * For example, if the starting buddy (buddy2) is #8 its order 367 * 1 buddy is #10: 368 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 369 * 370 * 2) Any buddy B will have an order O+1 parent P which 371 * satisfies the following equation: 372 * P = B & ~(1 << O) 373 * 374 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 375 */ 376static inline struct page * 377__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order) 378{ 379 unsigned long buddy_idx = page_idx ^ (1 << order); 380 381 return page + (buddy_idx - page_idx); 382} 383 384static inline unsigned long 385__find_combined_index(unsigned long page_idx, unsigned int order) 386{ 387 return (page_idx & ~(1 << order)); 388} 389 390/* 391 * This function checks whether a page is free && is the buddy 392 * we can do coalesce a page and its buddy if 393 * (a) the buddy is not in a hole && 394 * (b) the buddy is in the buddy system && 395 * (c) a page and its buddy have the same order && 396 * (d) a page and its buddy are in the same zone. 397 * 398 * For recording whether a page is in the buddy system, we use PG_buddy. 399 * Setting, clearing, and testing PG_buddy is serialized by zone->lock. 400 * 401 * For recording page's order, we use page_private(page). 402 */ 403static inline int page_is_buddy(struct page *page, struct page *buddy, 404 int order) 405{ 406 if (!pfn_valid_within(page_to_pfn(buddy))) 407 return 0; 408 409 if (page_zone_id(page) != page_zone_id(buddy)) 410 return 0; 411 412 if (PageBuddy(buddy) && page_order(buddy) == order) { 413 VM_BUG_ON(page_count(buddy) != 0); 414 return 1; 415 } 416 return 0; 417} 418 419/* 420 * Freeing function for a buddy system allocator. 421 * 422 * The concept of a buddy system is to maintain direct-mapped table 423 * (containing bit values) for memory blocks of various "orders". 424 * The bottom level table contains the map for the smallest allocatable 425 * units of memory (here, pages), and each level above it describes 426 * pairs of units from the levels below, hence, "buddies". 427 * At a high level, all that happens here is marking the table entry 428 * at the bottom level available, and propagating the changes upward 429 * as necessary, plus some accounting needed to play nicely with other 430 * parts of the VM system. 431 * At each level, we keep a list of pages, which are heads of continuous 432 * free pages of length of (1 << order) and marked with PG_buddy. Page's 433 * order is recorded in page_private(page) field. 434 * So when we are allocating or freeing one, we can derive the state of the 435 * other. That is, if we allocate a small block, and both were 436 * free, the remainder of the region must be split into blocks. 437 * If a block is freed, and its buddy is also free, then this 438 * triggers coalescing into a block of larger size. 439 * 440 * -- wli 441 */ 442 443static inline void __free_one_page(struct page *page, 444 struct zone *zone, unsigned int order, 445 int migratetype) 446{ 447 unsigned long page_idx; 448 449 if (unlikely(PageCompound(page))) 450 if (unlikely(destroy_compound_page(page, order))) 451 return; 452 453 VM_BUG_ON(migratetype == -1); 454 455 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); 456 457 VM_BUG_ON(page_idx & ((1 << order) - 1)); 458 VM_BUG_ON(bad_range(zone, page)); 459 460 while (order < MAX_ORDER-1) { 461 unsigned long combined_idx; 462 struct page *buddy; 463 464 buddy = __page_find_buddy(page, page_idx, order); 465 if (!page_is_buddy(page, buddy, order)) 466 break; 467 468 /* Our buddy is free, merge with it and move up one order. */ 469 list_del(&buddy->lru); 470 zone->free_area[order].nr_free--; 471 rmv_page_order(buddy); 472 combined_idx = __find_combined_index(page_idx, order); 473 page = page + (combined_idx - page_idx); 474 page_idx = combined_idx; 475 order++; 476 } 477 set_page_order(page, order); 478 list_add(&page->lru, 479 &zone->free_area[order].free_list[migratetype]); 480 zone->free_area[order].nr_free++; 481} 482 483#ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT 484/* 485 * free_page_mlock() -- clean up attempts to free and mlocked() page. 486 * Page should not be on lru, so no need to fix that up. 487 * free_pages_check() will verify... 488 */ 489static inline void free_page_mlock(struct page *page) 490{ 491 __dec_zone_page_state(page, NR_MLOCK); 492 __count_vm_event(UNEVICTABLE_MLOCKFREED); 493} 494#else 495static void free_page_mlock(struct page *page) { } 496#endif 497 498static inline int free_pages_check(struct page *page) 499{ 500 if (unlikely(page_mapcount(page) | 501 (page->mapping != NULL) | 502 (atomic_read(&page->_count) != 0) | 503 (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) { 504 bad_page(page); 505 return 1; 506 } 507 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP) 508 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; 509 return 0; 510} 511 512/* 513 * Frees a list of pages. 514 * Assumes all pages on list are in same zone, and of same order. 515 * count is the number of pages to free. 516 * 517 * If the zone was previously in an "all pages pinned" state then look to 518 * see if this freeing clears that state. 519 * 520 * And clear the zone's pages_scanned counter, to hold off the "all pages are 521 * pinned" detection logic. 522 */ 523static void free_pages_bulk(struct zone *zone, int count, 524 struct list_head *list, int order) 525{ 526 spin_lock(&zone->lock); 527 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); 528 zone->pages_scanned = 0; 529 530 __mod_zone_page_state(zone, NR_FREE_PAGES, count << order); 531 while (count--) { 532 struct page *page; 533 534 VM_BUG_ON(list_empty(list)); 535 page = list_entry(list->prev, struct page, lru); 536 /* have to delete it as __free_one_page list manipulates */ 537 list_del(&page->lru); 538 __free_one_page(page, zone, order, page_private(page)); 539 } 540 spin_unlock(&zone->lock); 541} 542 543static void free_one_page(struct zone *zone, struct page *page, int order, 544 int migratetype) 545{ 546 spin_lock(&zone->lock); 547 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); 548 zone->pages_scanned = 0; 549 550 __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order); 551 __free_one_page(page, zone, order, migratetype); 552 spin_unlock(&zone->lock); 553} 554 555static void __free_pages_ok(struct page *page, unsigned int order) 556{ 557 unsigned long flags; 558 int i; 559 int bad = 0; 560 int wasMlocked = TestClearPageMlocked(page); 561 562 kmemcheck_free_shadow(page, order); 563 564 for (i = 0 ; i < (1 << order) ; ++i) 565 bad += free_pages_check(page + i); 566 if (bad) 567 return; 568 569 if (!PageHighMem(page)) { 570 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order); 571 debug_check_no_obj_freed(page_address(page), 572 PAGE_SIZE << order); 573 } 574 arch_free_page(page, order); 575 kernel_map_pages(page, 1 << order, 0); 576 577 local_irq_save(flags); 578 if (unlikely(wasMlocked)) 579 free_page_mlock(page); 580 __count_vm_events(PGFREE, 1 << order); 581 free_one_page(page_zone(page), page, order, 582 get_pageblock_migratetype(page)); 583 local_irq_restore(flags); 584} 585 586/* 587 * permit the bootmem allocator to evade page validation on high-order frees 588 */ 589void __meminit __free_pages_bootmem(struct page *page, unsigned int order) 590{ 591 if (order == 0) { 592 __ClearPageReserved(page); 593 set_page_count(page, 0); 594 set_page_refcounted(page); 595 __free_page(page); 596 } else { 597 int loop; 598 599 prefetchw(page); 600 for (loop = 0; loop < BITS_PER_LONG; loop++) { 601 struct page *p = &page[loop]; 602 603 if (loop + 1 < BITS_PER_LONG) 604 prefetchw(p + 1); 605 __ClearPageReserved(p); 606 set_page_count(p, 0); 607 } 608 609 set_page_refcounted(page); 610 __free_pages(page, order); 611 } 612} 613 614 615/* 616 * The order of subdivision here is critical for the IO subsystem. 617 * Please do not alter this order without good reasons and regression 618 * testing. Specifically, as large blocks of memory are subdivided, 619 * the order in which smaller blocks are delivered depends on the order 620 * they're subdivided in this function. This is the primary factor 621 * influencing the order in which pages are delivered to the IO 622 * subsystem according to empirical testing, and this is also justified 623 * by considering the behavior of a buddy system containing a single 624 * large block of memory acted on by a series of small allocations. 625 * This behavior is a critical factor in sglist merging's success. 626 * 627 * -- wli 628 */ 629static inline void expand(struct zone *zone, struct page *page, 630 int low, int high, struct free_area *area, 631 int migratetype) 632{ 633 unsigned long size = 1 << high; 634 635 while (high > low) { 636 area--; 637 high--; 638 size >>= 1; 639 VM_BUG_ON(bad_range(zone, &page[size])); 640 list_add(&page[size].lru, &area->free_list[migratetype]); 641 area->nr_free++; 642 set_page_order(&page[size], high); 643 } 644} 645 646/* 647 * This page is about to be returned from the page allocator 648 */ 649static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) 650{ 651 if (unlikely(page_mapcount(page) | 652 (page->mapping != NULL) | 653 (atomic_read(&page->_count) != 0) | 654 (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) { 655 bad_page(page); 656 return 1; 657 } 658 659 set_page_private(page, 0); 660 set_page_refcounted(page); 661 662 arch_alloc_page(page, order); 663 kernel_map_pages(page, 1 << order, 1); 664 665 if (gfp_flags & __GFP_ZERO) 666 prep_zero_page(page, order, gfp_flags); 667 668 if (order && (gfp_flags & __GFP_COMP)) 669 prep_compound_page(page, order); 670 671 return 0; 672} 673 674/* 675 * Go through the free lists for the given migratetype and remove 676 * the smallest available page from the freelists 677 */ 678static inline 679struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, 680 int migratetype) 681{ 682 unsigned int current_order; 683 struct free_area * area; 684 struct page *page; 685 686 /* Find a page of the appropriate size in the preferred list */ 687 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 688 area = &(zone->free_area[current_order]); 689 if (list_empty(&area->free_list[migratetype])) 690 continue; 691 692 page = list_entry(area->free_list[migratetype].next, 693 struct page, lru); 694 list_del(&page->lru); 695 rmv_page_order(page); 696 area->nr_free--; 697 expand(zone, page, order, current_order, area, migratetype); 698 return page; 699 } 700 701 return NULL; 702} 703 704 705/* 706 * This array describes the order lists are fallen back to when 707 * the free lists for the desirable migrate type are depleted 708 */ 709static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = { 710 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 711 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 712 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, 713 [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */ 714}; 715 716/* 717 * Move the free pages in a range to the free lists of the requested type. 718 * Note that start_page and end_pages are not aligned on a pageblock 719 * boundary. If alignment is required, use move_freepages_block() 720 */ 721static int move_freepages(struct zone *zone, 722 struct page *start_page, struct page *end_page, 723 int migratetype) 724{ 725 struct page *page; 726 unsigned long order; 727 int pages_moved = 0; 728 729#ifndef CONFIG_HOLES_IN_ZONE 730 /* 731 * page_zone is not safe to call in this context when 732 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant 733 * anyway as we check zone boundaries in move_freepages_block(). 734 * Remove at a later date when no bug reports exist related to 735 * grouping pages by mobility 736 */ 737 BUG_ON(page_zone(start_page) != page_zone(end_page)); 738#endif 739 740 for (page = start_page; page <= end_page;) { 741 /* Make sure we are not inadvertently changing nodes */ 742 VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone)); 743 744 if (!pfn_valid_within(page_to_pfn(page))) { 745 page++; 746 continue; 747 } 748 749 if (!PageBuddy(page)) { 750 page++; 751 continue; 752 } 753 754 order = page_order(page); 755 list_del(&page->lru); 756 list_add(&page->lru, 757 &zone->free_area[order].free_list[migratetype]); 758 page += 1 << order; 759 pages_moved += 1 << order; 760 } 761 762 return pages_moved; 763} 764 765static int move_freepages_block(struct zone *zone, struct page *page, 766 int migratetype) 767{ 768 unsigned long start_pfn, end_pfn; 769 struct page *start_page, *end_page; 770 771 start_pfn = page_to_pfn(page); 772 start_pfn = start_pfn & ~(pageblock_nr_pages-1); 773 start_page = pfn_to_page(start_pfn); 774 end_page = start_page + pageblock_nr_pages - 1; 775 end_pfn = start_pfn + pageblock_nr_pages - 1; 776 777 /* Do not cross zone boundaries */ 778 if (start_pfn < zone->zone_start_pfn) 779 start_page = page; 780 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages) 781 return 0; 782 783 return move_freepages(zone, start_page, end_page, migratetype); 784} 785 786/* Remove an element from the buddy allocator from the fallback list */ 787static inline struct page * 788__rmqueue_fallback(struct zone *zone, int order, int start_migratetype) 789{ 790 struct free_area * area; 791 int current_order; 792 struct page *page; 793 int migratetype, i; 794 795 /* Find the largest possible block of pages in the other list */ 796 for (current_order = MAX_ORDER-1; current_order >= order; 797 --current_order) { 798 for (i = 0; i < MIGRATE_TYPES - 1; i++) { 799 migratetype = fallbacks[start_migratetype][i]; 800 801 /* MIGRATE_RESERVE handled later if necessary */ 802 if (migratetype == MIGRATE_RESERVE) 803 continue; 804 805 area = &(zone->free_area[current_order]); 806 if (list_empty(&area->free_list[migratetype])) 807 continue; 808 809 page = list_entry(area->free_list[migratetype].next, 810 struct page, lru); 811 area->nr_free--; 812 813 /* 814 * If breaking a large block of pages, move all free 815 * pages to the preferred allocation list. If falling 816 * back for a reclaimable kernel allocation, be more 817 * agressive about taking ownership of free pages 818 */ 819 if (unlikely(current_order >= (pageblock_order >> 1)) || 820 start_migratetype == MIGRATE_RECLAIMABLE || 821 page_group_by_mobility_disabled) { 822 unsigned long pages; 823 pages = move_freepages_block(zone, page, 824 start_migratetype); 825 826 /* Claim the whole block if over half of it is free */ 827 if (pages >= (1 << (pageblock_order-1)) || 828 page_group_by_mobility_disabled) 829 set_pageblock_migratetype(page, 830 start_migratetype); 831 832 migratetype = start_migratetype; 833 } 834 835 /* Remove the page from the freelists */ 836 list_del(&page->lru); 837 rmv_page_order(page); 838 839 if (current_order == pageblock_order) 840 set_pageblock_migratetype(page, 841 start_migratetype); 842 843 expand(zone, page, order, current_order, area, migratetype); 844 return page; 845 } 846 } 847 848 return NULL; 849} 850 851/* 852 * Do the hard work of removing an element from the buddy allocator. 853 * Call me with the zone->lock already held. 854 */ 855static struct page *__rmqueue(struct zone *zone, unsigned int order, 856 int migratetype) 857{ 858 struct page *page; 859 860retry_reserve: 861 page = __rmqueue_smallest(zone, order, migratetype); 862 863 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) { 864 page = __rmqueue_fallback(zone, order, migratetype); 865 866 /* 867 * Use MIGRATE_RESERVE rather than fail an allocation. goto 868 * is used because __rmqueue_smallest is an inline function 869 * and we want just one call site 870 */ 871 if (!page) { 872 migratetype = MIGRATE_RESERVE; 873 goto retry_reserve; 874 } 875 } 876 877 return page; 878} 879 880/* 881 * Obtain a specified number of elements from the buddy allocator, all under 882 * a single hold of the lock, for efficiency. Add them to the supplied list. 883 * Returns the number of new pages which were placed at *list. 884 */ 885static int rmqueue_bulk(struct zone *zone, unsigned int order, 886 unsigned long count, struct list_head *list, 887 int migratetype, int cold) 888{ 889 int i; 890 891 spin_lock(&zone->lock); 892 for (i = 0; i < count; ++i) { 893 struct page *page = __rmqueue(zone, order, migratetype); 894 if (unlikely(page == NULL)) 895 break; 896 897 /* 898 * Split buddy pages returned by expand() are received here 899 * in physical page order. The page is added to the callers and 900 * list and the list head then moves forward. From the callers 901 * perspective, the linked list is ordered by page number in 902 * some conditions. This is useful for IO devices that can 903 * merge IO requests if the physical pages are ordered 904 * properly. 905 */ 906 if (likely(cold == 0)) 907 list_add(&page->lru, list); 908 else 909 list_add_tail(&page->lru, list); 910 set_page_private(page, migratetype); 911 list = &page->lru; 912 } 913 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); 914 spin_unlock(&zone->lock); 915 return i; 916} 917 918#ifdef CONFIG_NUMA 919/* 920 * Called from the vmstat counter updater to drain pagesets of this 921 * currently executing processor on remote nodes after they have 922 * expired. 923 * 924 * Note that this function must be called with the thread pinned to 925 * a single processor. 926 */ 927void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) 928{ 929 unsigned long flags; 930 int to_drain; 931 932 local_irq_save(flags); 933 if (pcp->count >= pcp->batch) 934 to_drain = pcp->batch; 935 else 936 to_drain = pcp->count; 937 free_pages_bulk(zone, to_drain, &pcp->list, 0); 938 pcp->count -= to_drain; 939 local_irq_restore(flags); 940} 941#endif 942 943/* 944 * Drain pages of the indicated processor. 945 * 946 * The processor must either be the current processor and the 947 * thread pinned to the current processor or a processor that 948 * is not online. 949 */ 950static void drain_pages(unsigned int cpu) 951{ 952 unsigned long flags; 953 struct zone *zone; 954 955 for_each_populated_zone(zone) { 956 struct per_cpu_pageset *pset; 957 struct per_cpu_pages *pcp; 958 959 pset = zone_pcp(zone, cpu); 960 961 pcp = &pset->pcp; 962 local_irq_save(flags); 963 free_pages_bulk(zone, pcp->count, &pcp->list, 0); 964 pcp->count = 0; 965 local_irq_restore(flags); 966 } 967} 968 969/* 970 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 971 */ 972void drain_local_pages(void *arg) 973{ 974 drain_pages(smp_processor_id()); 975} 976 977/* 978 * Spill all the per-cpu pages from all CPUs back into the buddy allocator 979 */ 980void drain_all_pages(void) 981{ 982 on_each_cpu(drain_local_pages, NULL, 1); 983} 984 985#ifdef CONFIG_HIBERNATION 986 987void mark_free_pages(struct zone *zone) 988{ 989 unsigned long pfn, max_zone_pfn; 990 unsigned long flags; 991 int order, t; 992 struct list_head *curr; 993 994 if (!zone->spanned_pages) 995 return; 996 997 spin_lock_irqsave(&zone->lock, flags); 998 999 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; 1000 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 1001 if (pfn_valid(pfn)) { 1002 struct page *page = pfn_to_page(pfn); 1003 1004 if (!swsusp_page_is_forbidden(page)) 1005 swsusp_unset_page_free(page); 1006 } 1007 1008 for_each_migratetype_order(order, t) { 1009 list_for_each(curr, &zone->free_area[order].free_list[t]) { 1010 unsigned long i; 1011 1012 pfn = page_to_pfn(list_entry(curr, struct page, lru)); 1013 for (i = 0; i < (1UL << order); i++) 1014 swsusp_set_page_free(pfn_to_page(pfn + i)); 1015 } 1016 } 1017 spin_unlock_irqrestore(&zone->lock, flags); 1018} 1019#endif /* CONFIG_PM */ 1020 1021/* 1022 * Free a 0-order page 1023 */ 1024static void free_hot_cold_page(struct page *page, int cold) 1025{ 1026 struct zone *zone = page_zone(page); 1027 struct per_cpu_pages *pcp; 1028 unsigned long flags; 1029 int wasMlocked = TestClearPageMlocked(page); 1030 1031 kmemcheck_free_shadow(page, 0); 1032 1033 if (PageAnon(page)) 1034 page->mapping = NULL; 1035 if (free_pages_check(page)) 1036 return; 1037 1038 if (!PageHighMem(page)) { 1039 debug_check_no_locks_freed(page_address(page), PAGE_SIZE); 1040 debug_check_no_obj_freed(page_address(page), PAGE_SIZE); 1041 } 1042 arch_free_page(page, 0); 1043 kernel_map_pages(page, 1, 0); 1044 1045 pcp = &zone_pcp(zone, get_cpu())->pcp; 1046 set_page_private(page, get_pageblock_migratetype(page)); 1047 local_irq_save(flags); 1048 if (unlikely(wasMlocked)) 1049 free_page_mlock(page); 1050 __count_vm_event(PGFREE); 1051 1052 if (cold) 1053 list_add_tail(&page->lru, &pcp->list); 1054 else 1055 list_add(&page->lru, &pcp->list); 1056 pcp->count++; 1057 if (pcp->count >= pcp->high) { 1058 free_pages_bulk(zone, pcp->batch, &pcp->list, 0); 1059 pcp->count -= pcp->batch; 1060 } 1061 local_irq_restore(flags); 1062 put_cpu(); 1063} 1064 1065void free_hot_page(struct page *page) 1066{ 1067 free_hot_cold_page(page, 0); 1068} 1069 1070void free_cold_page(struct page *page) 1071{ 1072 free_hot_cold_page(page, 1); 1073} 1074 1075/* 1076 * split_page takes a non-compound higher-order page, and splits it into 1077 * n (1<<order) sub-pages: page[0..n] 1078 * Each sub-page must be freed individually. 1079 * 1080 * Note: this is probably too low level an operation for use in drivers. 1081 * Please consult with lkml before using this in your driver. 1082 */ 1083void split_page(struct page *page, unsigned int order) 1084{ 1085 int i; 1086 1087 VM_BUG_ON(PageCompound(page)); 1088 VM_BUG_ON(!page_count(page)); 1089 1090#ifdef CONFIG_KMEMCHECK 1091 /* 1092 * Split shadow pages too, because free(page[0]) would 1093 * otherwise free the whole shadow. 1094 */ 1095 if (kmemcheck_page_is_tracked(page)) 1096 split_page(virt_to_page(page[0].shadow), order); 1097#endif 1098 1099 for (i = 1; i < (1 << order); i++) 1100 set_page_refcounted(page + i); 1101} 1102 1103/* 1104 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 1105 * we cheat by calling it from here, in the order > 0 path. Saves a branch 1106 * or two. 1107 */ 1108static inline 1109struct page *buffered_rmqueue(struct zone *preferred_zone, 1110 struct zone *zone, int order, gfp_t gfp_flags, 1111 int migratetype) 1112{ 1113 unsigned long flags; 1114 struct page *page; 1115 int cold = !!(gfp_flags & __GFP_COLD); 1116 int cpu; 1117 1118again: 1119 cpu = get_cpu(); 1120 if (likely(order == 0)) { 1121 struct per_cpu_pages *pcp; 1122 1123 pcp = &zone_pcp(zone, cpu)->pcp; 1124 local_irq_save(flags); 1125 if (!pcp->count) { 1126 pcp->count = rmqueue_bulk(zone, 0, 1127 pcp->batch, &pcp->list, 1128 migratetype, cold); 1129 if (unlikely(!pcp->count)) 1130 goto failed; 1131 } 1132 1133 /* Find a page of the appropriate migrate type */ 1134 if (cold) { 1135 list_for_each_entry_reverse(page, &pcp->list, lru) 1136 if (page_private(page) == migratetype) 1137 break; 1138 } else { 1139 list_for_each_entry(page, &pcp->list, lru) 1140 if (page_private(page) == migratetype) 1141 break; 1142 } 1143 1144 /* Allocate more to the pcp list if necessary */ 1145 if (unlikely(&page->lru == &pcp->list)) { 1146 pcp->count += rmqueue_bulk(zone, 0, 1147 pcp->batch, &pcp->list, 1148 migratetype, cold); 1149 page = list_entry(pcp->list.next, struct page, lru); 1150 } 1151 1152 list_del(&page->lru); 1153 pcp->count--; 1154 } else { 1155 if (unlikely(gfp_flags & __GFP_NOFAIL)) { 1156 /* 1157 * __GFP_NOFAIL is not to be used in new code. 1158 * 1159 * All __GFP_NOFAIL callers should be fixed so that they 1160 * properly detect and handle allocation failures. 1161 * 1162 * We most definitely don't want callers attempting to 1163 * allocate greater than order-1 page units with 1164 * __GFP_NOFAIL. 1165 */ 1166 WARN_ON_ONCE(order > 1); 1167 } 1168 spin_lock_irqsave(&zone->lock, flags); 1169 page = __rmqueue(zone, order, migratetype); 1170 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order)); 1171 spin_unlock(&zone->lock); 1172 if (!page) 1173 goto failed; 1174 } 1175 1176 __count_zone_vm_events(PGALLOC, zone, 1 << order); 1177 zone_statistics(preferred_zone, zone); 1178 local_irq_restore(flags); 1179 put_cpu(); 1180 1181 VM_BUG_ON(bad_range(zone, page)); 1182 if (prep_new_page(page, order, gfp_flags)) 1183 goto again; 1184 return page; 1185 1186failed: 1187 local_irq_restore(flags); 1188 put_cpu(); 1189 return NULL; 1190} 1191 1192/* The ALLOC_WMARK bits are used as an index to zone->watermark */ 1193#define ALLOC_WMARK_MIN WMARK_MIN 1194#define ALLOC_WMARK_LOW WMARK_LOW 1195#define ALLOC_WMARK_HIGH WMARK_HIGH 1196#define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 1197 1198/* Mask to get the watermark bits */ 1199#define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 1200 1201#define ALLOC_HARDER 0x10 /* try to alloc harder */ 1202#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 1203#define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 1204 1205#ifdef CONFIG_FAIL_PAGE_ALLOC 1206 1207static struct fail_page_alloc_attr { 1208 struct fault_attr attr; 1209 1210 u32 ignore_gfp_highmem; 1211 u32 ignore_gfp_wait; 1212 u32 min_order; 1213 1214#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1215 1216 struct dentry *ignore_gfp_highmem_file; 1217 struct dentry *ignore_gfp_wait_file; 1218 struct dentry *min_order_file; 1219 1220#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1221 1222} fail_page_alloc = { 1223 .attr = FAULT_ATTR_INITIALIZER, 1224 .ignore_gfp_wait = 1, 1225 .ignore_gfp_highmem = 1, 1226 .min_order = 1, 1227}; 1228 1229static int __init setup_fail_page_alloc(char *str) 1230{ 1231 return setup_fault_attr(&fail_page_alloc.attr, str); 1232} 1233__setup("fail_page_alloc=", setup_fail_page_alloc); 1234 1235static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1236{ 1237 if (order < fail_page_alloc.min_order) 1238 return 0; 1239 if (gfp_mask & __GFP_NOFAIL) 1240 return 0; 1241 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 1242 return 0; 1243 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) 1244 return 0; 1245 1246 return should_fail(&fail_page_alloc.attr, 1 << order); 1247} 1248 1249#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1250 1251static int __init fail_page_alloc_debugfs(void) 1252{ 1253 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; 1254 struct dentry *dir; 1255 int err; 1256 1257 err = init_fault_attr_dentries(&fail_page_alloc.attr, 1258 "fail_page_alloc"); 1259 if (err) 1260 return err; 1261 dir = fail_page_alloc.attr.dentries.dir; 1262 1263 fail_page_alloc.ignore_gfp_wait_file = 1264 debugfs_create_bool("ignore-gfp-wait", mode, dir, 1265 &fail_page_alloc.ignore_gfp_wait); 1266 1267 fail_page_alloc.ignore_gfp_highmem_file = 1268 debugfs_create_bool("ignore-gfp-highmem", mode, dir, 1269 &fail_page_alloc.ignore_gfp_highmem); 1270 fail_page_alloc.min_order_file = 1271 debugfs_create_u32("min-order", mode, dir, 1272 &fail_page_alloc.min_order); 1273 1274 if (!fail_page_alloc.ignore_gfp_wait_file || 1275 !fail_page_alloc.ignore_gfp_highmem_file || 1276 !fail_page_alloc.min_order_file) { 1277 err = -ENOMEM; 1278 debugfs_remove(fail_page_alloc.ignore_gfp_wait_file); 1279 debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file); 1280 debugfs_remove(fail_page_alloc.min_order_file); 1281 cleanup_fault_attr_dentries(&fail_page_alloc.attr); 1282 } 1283 1284 return err; 1285} 1286 1287late_initcall(fail_page_alloc_debugfs); 1288 1289#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1290 1291#else /* CONFIG_FAIL_PAGE_ALLOC */ 1292 1293static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1294{ 1295 return 0; 1296} 1297 1298#endif /* CONFIG_FAIL_PAGE_ALLOC */ 1299 1300/* 1301 * Return 1 if free pages are above 'mark'. This takes into account the order 1302 * of the allocation. 1303 */ 1304int zone_watermark_ok(struct zone *z, int order, unsigned long mark, 1305 int classzone_idx, int alloc_flags) 1306{ 1307 /* free_pages my go negative - that's OK */ 1308 long min = mark; 1309 long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1; 1310 int o; 1311 1312 if (alloc_flags & ALLOC_HIGH) 1313 min -= min / 2; 1314 if (alloc_flags & ALLOC_HARDER) 1315 min -= min / 4; 1316 1317 if (free_pages <= min + z->lowmem_reserve[classzone_idx]) 1318 return 0; 1319 for (o = 0; o < order; o++) { 1320 /* At the next order, this order's pages become unavailable */ 1321 free_pages -= z->free_area[o].nr_free << o; 1322 1323 /* Require fewer higher order pages to be free */ 1324 min >>= 1; 1325 1326 if (free_pages <= min) 1327 return 0; 1328 } 1329 return 1; 1330} 1331 1332#ifdef CONFIG_NUMA 1333/* 1334 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to 1335 * skip over zones that are not allowed by the cpuset, or that have 1336 * been recently (in last second) found to be nearly full. See further 1337 * comments in mmzone.h. Reduces cache footprint of zonelist scans 1338 * that have to skip over a lot of full or unallowed zones. 1339 * 1340 * If the zonelist cache is present in the passed in zonelist, then 1341 * returns a pointer to the allowed node mask (either the current 1342 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].) 1343 * 1344 * If the zonelist cache is not available for this zonelist, does 1345 * nothing and returns NULL. 1346 * 1347 * If the fullzones BITMAP in the zonelist cache is stale (more than 1348 * a second since last zap'd) then we zap it out (clear its bits.) 1349 * 1350 * We hold off even calling zlc_setup, until after we've checked the 1351 * first zone in the zonelist, on the theory that most allocations will 1352 * be satisfied from that first zone, so best to examine that zone as 1353 * quickly as we can. 1354 */ 1355static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1356{ 1357 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1358 nodemask_t *allowednodes; /* zonelist_cache approximation */ 1359 1360 zlc = zonelist->zlcache_ptr; 1361 if (!zlc) 1362 return NULL; 1363 1364 if (time_after(jiffies, zlc->last_full_zap + HZ)) { 1365 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1366 zlc->last_full_zap = jiffies; 1367 } 1368 1369 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? 1370 &cpuset_current_mems_allowed : 1371 &node_states[N_HIGH_MEMORY]; 1372 return allowednodes; 1373} 1374 1375/* 1376 * Given 'z' scanning a zonelist, run a couple of quick checks to see 1377 * if it is worth looking at further for free memory: 1378 * 1) Check that the zone isn't thought to be full (doesn't have its 1379 * bit set in the zonelist_cache fullzones BITMAP). 1380 * 2) Check that the zones node (obtained from the zonelist_cache 1381 * z_to_n[] mapping) is allowed in the passed in allowednodes mask. 1382 * Return true (non-zero) if zone is worth looking at further, or 1383 * else return false (zero) if it is not. 1384 * 1385 * This check -ignores- the distinction between various watermarks, 1386 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is 1387 * found to be full for any variation of these watermarks, it will 1388 * be considered full for up to one second by all requests, unless 1389 * we are so low on memory on all allowed nodes that we are forced 1390 * into the second scan of the zonelist. 1391 * 1392 * In the second scan we ignore this zonelist cache and exactly 1393 * apply the watermarks to all zones, even it is slower to do so. 1394 * We are low on memory in the second scan, and should leave no stone 1395 * unturned looking for a free page. 1396 */ 1397static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1398 nodemask_t *allowednodes) 1399{ 1400 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1401 int i; /* index of *z in zonelist zones */ 1402 int n; /* node that zone *z is on */ 1403 1404 zlc = zonelist->zlcache_ptr; 1405 if (!zlc) 1406 return 1; 1407 1408 i = z - zonelist->_zonerefs; 1409 n = zlc->z_to_n[i]; 1410 1411 /* This zone is worth trying if it is allowed but not full */ 1412 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); 1413} 1414 1415/* 1416 * Given 'z' scanning a zonelist, set the corresponding bit in 1417 * zlc->fullzones, so that subsequent attempts to allocate a page 1418 * from that zone don't waste time re-examining it. 1419 */ 1420static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1421{ 1422 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1423 int i; /* index of *z in zonelist zones */ 1424 1425 zlc = zonelist->zlcache_ptr; 1426 if (!zlc) 1427 return; 1428 1429 i = z - zonelist->_zonerefs; 1430 1431 set_bit(i, zlc->fullzones); 1432} 1433 1434#else /* CONFIG_NUMA */ 1435 1436static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1437{ 1438 return NULL; 1439} 1440 1441static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1442 nodemask_t *allowednodes) 1443{ 1444 return 1; 1445} 1446 1447static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1448{ 1449} 1450#endif /* CONFIG_NUMA */ 1451 1452/* 1453 * get_page_from_freelist goes through the zonelist trying to allocate 1454 * a page. 1455 */ 1456static struct page * 1457get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order, 1458 struct zonelist *zonelist, int high_zoneidx, int alloc_flags, 1459 struct zone *preferred_zone, int migratetype) 1460{ 1461 struct zoneref *z; 1462 struct page *page = NULL; 1463 int classzone_idx; 1464 struct zone *zone; 1465 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ 1466 int zlc_active = 0; /* set if using zonelist_cache */ 1467 int did_zlc_setup = 0; /* just call zlc_setup() one time */ 1468 1469 classzone_idx = zone_idx(preferred_zone); 1470zonelist_scan: 1471 /* 1472 * Scan zonelist, looking for a zone with enough free. 1473 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1474 */ 1475 for_each_zone_zonelist_nodemask(zone, z, zonelist, 1476 high_zoneidx, nodemask) { 1477 if (NUMA_BUILD && zlc_active && 1478 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 1479 continue; 1480 if ((alloc_flags & ALLOC_CPUSET) && 1481 !cpuset_zone_allowed_softwall(zone, gfp_mask)) 1482 goto try_next_zone; 1483 1484 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK); 1485 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { 1486 unsigned long mark; 1487 int ret; 1488 1489 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK]; 1490 if (zone_watermark_ok(zone, order, mark, 1491 classzone_idx, alloc_flags)) 1492 goto try_this_zone; 1493 1494 if (zone_reclaim_mode == 0) 1495 goto this_zone_full; 1496 1497 ret = zone_reclaim(zone, gfp_mask, order); 1498 switch (ret) { 1499 case ZONE_RECLAIM_NOSCAN: 1500 /* did not scan */ 1501 goto try_next_zone; 1502 case ZONE_RECLAIM_FULL: 1503 /* scanned but unreclaimable */ 1504 goto this_zone_full; 1505 default: 1506 /* did we reclaim enough */ 1507 if (!zone_watermark_ok(zone, order, mark, 1508 classzone_idx, alloc_flags)) 1509 goto this_zone_full; 1510 } 1511 } 1512 1513try_this_zone: 1514 page = buffered_rmqueue(preferred_zone, zone, order, 1515 gfp_mask, migratetype); 1516 if (page) 1517 break; 1518this_zone_full: 1519 if (NUMA_BUILD) 1520 zlc_mark_zone_full(zonelist, z); 1521try_next_zone: 1522 if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) { 1523 /* 1524 * we do zlc_setup after the first zone is tried but only 1525 * if there are multiple nodes make it worthwhile 1526 */ 1527 allowednodes = zlc_setup(zonelist, alloc_flags); 1528 zlc_active = 1; 1529 did_zlc_setup = 1; 1530 } 1531 } 1532 1533 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) { 1534 /* Disable zlc cache for second zonelist scan */ 1535 zlc_active = 0; 1536 goto zonelist_scan; 1537 } 1538 return page; 1539} 1540 1541static inline int 1542should_alloc_retry(gfp_t gfp_mask, unsigned int order, 1543 unsigned long pages_reclaimed) 1544{ 1545 /* Do not loop if specifically requested */ 1546 if (gfp_mask & __GFP_NORETRY) 1547 return 0; 1548 1549 /* 1550 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER 1551 * means __GFP_NOFAIL, but that may not be true in other 1552 * implementations. 1553 */ 1554 if (order <= PAGE_ALLOC_COSTLY_ORDER) 1555 return 1; 1556 1557 /* 1558 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is 1559 * specified, then we retry until we no longer reclaim any pages 1560 * (above), or we've reclaimed an order of pages at least as 1561 * large as the allocation's order. In both cases, if the 1562 * allocation still fails, we stop retrying. 1563 */ 1564 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order)) 1565 return 1; 1566 1567 /* 1568 * Don't let big-order allocations loop unless the caller 1569 * explicitly requests that. 1570 */ 1571 if (gfp_mask & __GFP_NOFAIL) 1572 return 1; 1573 1574 return 0; 1575} 1576 1577static inline struct page * 1578__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, 1579 struct zonelist *zonelist, enum zone_type high_zoneidx, 1580 nodemask_t *nodemask, struct zone *preferred_zone, 1581 int migratetype) 1582{ 1583 struct page *page; 1584 1585 /* Acquire the OOM killer lock for the zones in zonelist */ 1586 if (!try_set_zone_oom(zonelist, gfp_mask)) { 1587 schedule_timeout_uninterruptible(1); 1588 return NULL; 1589 } 1590 1591 /* 1592 * Go through the zonelist yet one more time, keep very high watermark 1593 * here, this is only to catch a parallel oom killing, we must fail if 1594 * we're still under heavy pressure. 1595 */ 1596 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, 1597 order, zonelist, high_zoneidx, 1598 ALLOC_WMARK_HIGH|ALLOC_CPUSET, 1599 preferred_zone, migratetype); 1600 if (page) 1601 goto out; 1602 1603 /* The OOM killer will not help higher order allocs */ 1604 if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_NOFAIL)) 1605 goto out; 1606 1607 /* Exhausted what can be done so it's blamo time */ 1608 out_of_memory(zonelist, gfp_mask, order); 1609 1610out: 1611 clear_zonelist_oom(zonelist, gfp_mask); 1612 return page; 1613} 1614 1615/* The really slow allocator path where we enter direct reclaim */ 1616static inline struct page * 1617__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order, 1618 struct zonelist *zonelist, enum zone_type high_zoneidx, 1619 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, 1620 int migratetype, unsigned long *did_some_progress) 1621{ 1622 struct page *page = NULL; 1623 struct reclaim_state reclaim_state; 1624 struct task_struct *p = current; 1625 1626 cond_resched(); 1627 1628 /* We now go into synchronous reclaim */ 1629 cpuset_memory_pressure_bump(); 1630 p->flags |= PF_MEMALLOC; 1631 lockdep_set_current_reclaim_state(gfp_mask); 1632 reclaim_state.reclaimed_slab = 0; 1633 p->reclaim_state = &reclaim_state; 1634 1635 *did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask); 1636 1637 p->reclaim_state = NULL; 1638 lockdep_clear_current_reclaim_state(); 1639 p->flags &= ~PF_MEMALLOC; 1640 1641 cond_resched(); 1642 1643 if (order != 0) 1644 drain_all_pages(); 1645 1646 if (likely(*did_some_progress)) 1647 page = get_page_from_freelist(gfp_mask, nodemask, order, 1648 zonelist, high_zoneidx, 1649 alloc_flags, preferred_zone, 1650 migratetype); 1651 return page; 1652} 1653 1654/* 1655 * This is called in the allocator slow-path if the allocation request is of 1656 * sufficient urgency to ignore watermarks and take other desperate measures 1657 */ 1658static inline struct page * 1659__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order, 1660 struct zonelist *zonelist, enum zone_type high_zoneidx, 1661 nodemask_t *nodemask, struct zone *preferred_zone, 1662 int migratetype) 1663{ 1664 struct page *page; 1665 1666 do { 1667 page = get_page_from_freelist(gfp_mask, nodemask, order, 1668 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS, 1669 preferred_zone, migratetype); 1670 1671 if (!page && gfp_mask & __GFP_NOFAIL) 1672 congestion_wait(BLK_RW_ASYNC, HZ/50); 1673 } while (!page && (gfp_mask & __GFP_NOFAIL)); 1674 1675 return page; 1676} 1677 1678static inline 1679void wake_all_kswapd(unsigned int order, struct zonelist *zonelist, 1680 enum zone_type high_zoneidx) 1681{ 1682 struct zoneref *z; 1683 struct zone *zone; 1684 1685 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) 1686 wakeup_kswapd(zone, order); 1687} 1688 1689static inline int 1690gfp_to_alloc_flags(gfp_t gfp_mask) 1691{ 1692 struct task_struct *p = current; 1693 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; 1694 const gfp_t wait = gfp_mask & __GFP_WAIT; 1695 1696 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */ 1697 BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH); 1698 1699 /* 1700 * The caller may dip into page reserves a bit more if the caller 1701 * cannot run direct reclaim, or if the caller has realtime scheduling 1702 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will 1703 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). 1704 */ 1705 alloc_flags |= (gfp_mask & __GFP_HIGH); 1706 1707 if (!wait) { 1708 alloc_flags |= ALLOC_HARDER; 1709 /* 1710 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. 1711 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1712 */ 1713 alloc_flags &= ~ALLOC_CPUSET; 1714 } else if (unlikely(rt_task(p))) 1715 alloc_flags |= ALLOC_HARDER; 1716 1717 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) { 1718 if (!in_interrupt() && 1719 ((p->flags & PF_MEMALLOC) || 1720 unlikely(test_thread_flag(TIF_MEMDIE)))) 1721 alloc_flags |= ALLOC_NO_WATERMARKS; 1722 } 1723 1724 return alloc_flags; 1725} 1726 1727static inline struct page * 1728__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, 1729 struct zonelist *zonelist, enum zone_type high_zoneidx, 1730 nodemask_t *nodemask, struct zone *preferred_zone, 1731 int migratetype) 1732{ 1733 const gfp_t wait = gfp_mask & __GFP_WAIT; 1734 struct page *page = NULL; 1735 int alloc_flags; 1736 unsigned long pages_reclaimed = 0; 1737 unsigned long did_some_progress; 1738 struct task_struct *p = current; 1739 1740 /* 1741 * In the slowpath, we sanity check order to avoid ever trying to 1742 * reclaim >= MAX_ORDER areas which will never succeed. Callers may 1743 * be using allocators in order of preference for an area that is 1744 * too large. 1745 */ 1746 if (order >= MAX_ORDER) { 1747 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN)); 1748 return NULL; 1749 } 1750 1751 /* 1752 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and 1753 * __GFP_NOWARN set) should not cause reclaim since the subsystem 1754 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim 1755 * using a larger set of nodes after it has established that the 1756 * allowed per node queues are empty and that nodes are 1757 * over allocated. 1758 */ 1759 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) 1760 goto nopage; 1761 1762 wake_all_kswapd(order, zonelist, high_zoneidx); 1763 1764 /* 1765 * OK, we're below the kswapd watermark and have kicked background 1766 * reclaim. Now things get more complex, so set up alloc_flags according 1767 * to how we want to proceed. 1768 */ 1769 alloc_flags = gfp_to_alloc_flags(gfp_mask); 1770 1771restart: 1772 /* This is the last chance, in general, before the goto nopage. */ 1773 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, 1774 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS, 1775 preferred_zone, migratetype); 1776 if (page) 1777 goto got_pg; 1778 1779rebalance: 1780 /* Allocate without watermarks if the context allows */ 1781 if (alloc_flags & ALLOC_NO_WATERMARKS) { 1782 page = __alloc_pages_high_priority(gfp_mask, order, 1783 zonelist, high_zoneidx, nodemask, 1784 preferred_zone, migratetype); 1785 if (page) 1786 goto got_pg; 1787 } 1788 1789 /* Atomic allocations - we can't balance anything */ 1790 if (!wait) 1791 goto nopage; 1792 1793 /* Avoid recursion of direct reclaim */ 1794 if (p->flags & PF_MEMALLOC) 1795 goto nopage; 1796 1797 /* Avoid allocations with no watermarks from looping endlessly */ 1798 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL)) 1799 goto nopage; 1800 1801 /* Try direct reclaim and then allocating */ 1802 page = __alloc_pages_direct_reclaim(gfp_mask, order, 1803 zonelist, high_zoneidx, 1804 nodemask, 1805 alloc_flags, preferred_zone, 1806 migratetype, &did_some_progress); 1807 if (page) 1808 goto got_pg; 1809 1810 /* 1811 * If we failed to make any progress reclaiming, then we are 1812 * running out of options and have to consider going OOM 1813 */ 1814 if (!did_some_progress) { 1815 if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { 1816 if (oom_killer_disabled) 1817 goto nopage; 1818 page = __alloc_pages_may_oom(gfp_mask, order, 1819 zonelist, high_zoneidx, 1820 nodemask, preferred_zone, 1821 migratetype); 1822 if (page) 1823 goto got_pg; 1824 1825 /* 1826 * The OOM killer does not trigger for high-order 1827 * ~__GFP_NOFAIL allocations so if no progress is being 1828 * made, there are no other options and retrying is 1829 * unlikely to help. 1830 */ 1831 if (order > PAGE_ALLOC_COSTLY_ORDER && 1832 !(gfp_mask & __GFP_NOFAIL)) 1833 goto nopage; 1834 1835 goto restart; 1836 } 1837 } 1838 1839 /* Check if we should retry the allocation */ 1840 pages_reclaimed += did_some_progress; 1841 if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) { 1842 /* Wait for some write requests to complete then retry */ 1843 congestion_wait(BLK_RW_ASYNC, HZ/50); 1844 goto rebalance; 1845 } 1846 1847nopage: 1848 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { 1849 printk(KERN_WARNING "%s: page allocation failure." 1850 " order:%d, mode:0x%x\n", 1851 p->comm, order, gfp_mask); 1852 dump_stack(); 1853 show_mem(); 1854 } 1855 return page; 1856got_pg: 1857 if (kmemcheck_enabled) 1858 kmemcheck_pagealloc_alloc(page, order, gfp_mask); 1859 return page; 1860 1861} 1862 1863/* 1864 * This is the 'heart' of the zoned buddy allocator. 1865 */ 1866struct page * 1867__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, 1868 struct zonelist *zonelist, nodemask_t *nodemask) 1869{ 1870 enum zone_type high_zoneidx = gfp_zone(gfp_mask); 1871 struct zone *preferred_zone; 1872 struct page *page; 1873 int migratetype = allocflags_to_migratetype(gfp_mask); 1874 1875 gfp_mask &= gfp_allowed_mask; 1876 1877 lockdep_trace_alloc(gfp_mask); 1878 1879 might_sleep_if(gfp_mask & __GFP_WAIT); 1880 1881 if (should_fail_alloc_page(gfp_mask, order)) 1882 return NULL; 1883 1884 /* 1885 * Check the zones suitable for the gfp_mask contain at least one 1886 * valid zone. It's possible to have an empty zonelist as a result 1887 * of GFP_THISNODE and a memoryless node 1888 */ 1889 if (unlikely(!zonelist->_zonerefs->zone)) 1890 return NULL; 1891 1892 /* The preferred zone is used for statistics later */ 1893 first_zones_zonelist(zonelist, high_zoneidx, nodemask, &preferred_zone); 1894 if (!preferred_zone) 1895 return NULL; 1896 1897 /* First allocation attempt */ 1898 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order, 1899 zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET, 1900 preferred_zone, migratetype); 1901 if (unlikely(!page)) 1902 page = __alloc_pages_slowpath(gfp_mask, order, 1903 zonelist, high_zoneidx, nodemask, 1904 preferred_zone, migratetype); 1905 1906 return page; 1907} 1908EXPORT_SYMBOL(__alloc_pages_nodemask); 1909 1910/* 1911 * Common helper functions. 1912 */ 1913unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 1914{ 1915 struct page * page; 1916 page = alloc_pages(gfp_mask, order); 1917 if (!page) 1918 return 0; 1919 return (unsigned long) page_address(page); 1920} 1921 1922EXPORT_SYMBOL(__get_free_pages); 1923 1924unsigned long get_zeroed_page(gfp_t gfp_mask) 1925{ 1926 struct page * page; 1927 1928 /* 1929 * get_zeroed_page() returns a 32-bit address, which cannot represent 1930 * a highmem page 1931 */ 1932 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 1933 1934 page = alloc_pages(gfp_mask | __GFP_ZERO, 0); 1935 if (page) 1936 return (unsigned long) page_address(page); 1937 return 0; 1938} 1939 1940EXPORT_SYMBOL(get_zeroed_page); 1941 1942void __pagevec_free(struct pagevec *pvec) 1943{ 1944 int i = pagevec_count(pvec); 1945 1946 while (--i >= 0) 1947 free_hot_cold_page(pvec->pages[i], pvec->cold); 1948} 1949 1950void __free_pages(struct page *page, unsigned int order) 1951{ 1952 if (put_page_testzero(page)) { 1953 if (order == 0) 1954 free_hot_page(page); 1955 else 1956 __free_pages_ok(page, order); 1957 } 1958} 1959 1960EXPORT_SYMBOL(__free_pages); 1961 1962void free_pages(unsigned long addr, unsigned int order) 1963{ 1964 if (addr != 0) { 1965 VM_BUG_ON(!virt_addr_valid((void *)addr)); 1966 __free_pages(virt_to_page((void *)addr), order); 1967 } 1968} 1969 1970EXPORT_SYMBOL(free_pages); 1971 1972/** 1973 * alloc_pages_exact - allocate an exact number physically-contiguous pages. 1974 * @size: the number of bytes to allocate 1975 * @gfp_mask: GFP flags for the allocation 1976 * 1977 * This function is similar to alloc_pages(), except that it allocates the 1978 * minimum number of pages to satisfy the request. alloc_pages() can only 1979 * allocate memory in power-of-two pages. 1980 * 1981 * This function is also limited by MAX_ORDER. 1982 * 1983 * Memory allocated by this function must be released by free_pages_exact(). 1984 */ 1985void *alloc_pages_exact(size_t size, gfp_t gfp_mask) 1986{ 1987 unsigned int order = get_order(size); 1988 unsigned long addr; 1989 1990 addr = __get_free_pages(gfp_mask, order); 1991 if (addr) { 1992 unsigned long alloc_end = addr + (PAGE_SIZE << order); 1993 unsigned long used = addr + PAGE_ALIGN(size); 1994 1995 split_page(virt_to_page((void *)addr), order); 1996 while (used < alloc_end) { 1997 free_page(used); 1998 used += PAGE_SIZE; 1999 } 2000 } 2001 2002 return (void *)addr; 2003} 2004EXPORT_SYMBOL(alloc_pages_exact); 2005 2006/** 2007 * free_pages_exact - release memory allocated via alloc_pages_exact() 2008 * @virt: the value returned by alloc_pages_exact. 2009 * @size: size of allocation, same value as passed to alloc_pages_exact(). 2010 * 2011 * Release the memory allocated by a previous call to alloc_pages_exact. 2012 */ 2013void free_pages_exact(void *virt, size_t size) 2014{ 2015 unsigned long addr = (unsigned long)virt; 2016 unsigned long end = addr + PAGE_ALIGN(size); 2017 2018 while (addr < end) { 2019 free_page(addr); 2020 addr += PAGE_SIZE; 2021 } 2022} 2023EXPORT_SYMBOL(free_pages_exact); 2024 2025static unsigned int nr_free_zone_pages(int offset) 2026{ 2027 struct zoneref *z; 2028 struct zone *zone; 2029 2030 /* Just pick one node, since fallback list is circular */ 2031 unsigned int sum = 0; 2032 2033 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); 2034 2035 for_each_zone_zonelist(zone, z, zonelist, offset) { 2036 unsigned long size = zone->present_pages; 2037 unsigned long high = high_wmark_pages(zone); 2038 if (size > high) 2039 sum += size - high; 2040 } 2041 2042 return sum; 2043} 2044 2045/* 2046 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL 2047 */ 2048unsigned int nr_free_buffer_pages(void) 2049{ 2050 return nr_free_zone_pages(gfp_zone(GFP_USER)); 2051} 2052EXPORT_SYMBOL_GPL(nr_free_buffer_pages); 2053 2054/* 2055 * Amount of free RAM allocatable within all zones 2056 */ 2057unsigned int nr_free_pagecache_pages(void) 2058{ 2059 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); 2060} 2061 2062static inline void show_node(struct zone *zone) 2063{ 2064 if (NUMA_BUILD) 2065 printk("Node %d ", zone_to_nid(zone)); 2066} 2067 2068void si_meminfo(struct sysinfo *val) 2069{ 2070 val->totalram = totalram_pages; 2071 val->sharedram = 0; 2072 val->freeram = global_page_state(NR_FREE_PAGES); 2073 val->bufferram = nr_blockdev_pages(); 2074 val->totalhigh = totalhigh_pages; 2075 val->freehigh = nr_free_highpages(); 2076 val->mem_unit = PAGE_SIZE; 2077} 2078 2079EXPORT_SYMBOL(si_meminfo); 2080 2081#ifdef CONFIG_NUMA 2082void si_meminfo_node(struct sysinfo *val, int nid) 2083{ 2084 pg_data_t *pgdat = NODE_DATA(nid); 2085 2086 val->totalram = pgdat->node_present_pages; 2087 val->freeram = node_page_state(nid, NR_FREE_PAGES); 2088#ifdef CONFIG_HIGHMEM 2089 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; 2090 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], 2091 NR_FREE_PAGES); 2092#else 2093 val->totalhigh = 0; 2094 val->freehigh = 0; 2095#endif 2096 val->mem_unit = PAGE_SIZE; 2097} 2098#endif 2099 2100#define K(x) ((x) << (PAGE_SHIFT-10)) 2101 2102/* 2103 * Show free area list (used inside shift_scroll-lock stuff) 2104 * We also calculate the percentage fragmentation. We do this by counting the 2105 * memory on each free list with the exception of the first item on the list. 2106 */ 2107void show_free_areas(void) 2108{ 2109 int cpu; 2110 struct zone *zone; 2111 2112 for_each_populated_zone(zone) { 2113 show_node(zone); 2114 printk("%s per-cpu:\n", zone->name); 2115 2116 for_each_online_cpu(cpu) { 2117 struct per_cpu_pageset *pageset; 2118 2119 pageset = zone_pcp(zone, cpu); 2120 2121 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n", 2122 cpu, pageset->pcp.high, 2123 pageset->pcp.batch, pageset->pcp.count); 2124 } 2125 } 2126 2127 printk("Active_anon:%lu active_file:%lu inactive_anon:%lu\n" 2128 " inactive_file:%lu" 2129 " unevictable:%lu" 2130 " dirty:%lu writeback:%lu unstable:%lu\n" 2131 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n", 2132 global_page_state(NR_ACTIVE_ANON), 2133 global_page_state(NR_ACTIVE_FILE), 2134 global_page_state(NR_INACTIVE_ANON), 2135 global_page_state(NR_INACTIVE_FILE), 2136 global_page_state(NR_UNEVICTABLE), 2137 global_page_state(NR_FILE_DIRTY), 2138 global_page_state(NR_WRITEBACK), 2139 global_page_state(NR_UNSTABLE_NFS), 2140 global_page_state(NR_FREE_PAGES), 2141 global_page_state(NR_SLAB_RECLAIMABLE) + 2142 global_page_state(NR_SLAB_UNRECLAIMABLE), 2143 global_page_state(NR_FILE_MAPPED), 2144 global_page_state(NR_PAGETABLE), 2145 global_page_state(NR_BOUNCE)); 2146 2147 for_each_populated_zone(zone) { 2148 int i; 2149 2150 show_node(zone); 2151 printk("%s" 2152 " free:%lukB" 2153 " min:%lukB" 2154 " low:%lukB" 2155 " high:%lukB" 2156 " active_anon:%lukB" 2157 " inactive_anon:%lukB" 2158 " active_file:%lukB" 2159 " inactive_file:%lukB" 2160 " unevictable:%lukB" 2161 " present:%lukB" 2162 " pages_scanned:%lu" 2163 " all_unreclaimable? %s" 2164 "\n", 2165 zone->name, 2166 K(zone_page_state(zone, NR_FREE_PAGES)), 2167 K(min_wmark_pages(zone)), 2168 K(low_wmark_pages(zone)), 2169 K(high_wmark_pages(zone)), 2170 K(zone_page_state(zone, NR_ACTIVE_ANON)), 2171 K(zone_page_state(zone, NR_INACTIVE_ANON)), 2172 K(zone_page_state(zone, NR_ACTIVE_FILE)), 2173 K(zone_page_state(zone, NR_INACTIVE_FILE)), 2174 K(zone_page_state(zone, NR_UNEVICTABLE)), 2175 K(zone->present_pages), 2176 zone->pages_scanned, 2177 (zone_is_all_unreclaimable(zone) ? "yes" : "no") 2178 ); 2179 printk("lowmem_reserve[]:"); 2180 for (i = 0; i < MAX_NR_ZONES; i++) 2181 printk(" %lu", zone->lowmem_reserve[i]); 2182 printk("\n"); 2183 } 2184 2185 for_each_populated_zone(zone) { 2186 unsigned long nr[MAX_ORDER], flags, order, total = 0; 2187 2188 show_node(zone); 2189 printk("%s: ", zone->name); 2190 2191 spin_lock_irqsave(&zone->lock, flags); 2192 for (order = 0; order < MAX_ORDER; order++) { 2193 nr[order] = zone->free_area[order].nr_free; 2194 total += nr[order] << order; 2195 } 2196 spin_unlock_irqrestore(&zone->lock, flags); 2197 for (order = 0; order < MAX_ORDER; order++) 2198 printk("%lu*%lukB ", nr[order], K(1UL) << order); 2199 printk("= %lukB\n", K(total)); 2200 } 2201 2202 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES)); 2203 2204 show_swap_cache_info(); 2205} 2206 2207static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) 2208{ 2209 zoneref->zone = zone; 2210 zoneref->zone_idx = zone_idx(zone); 2211} 2212 2213/* 2214 * Builds allocation fallback zone lists. 2215 * 2216 * Add all populated zones of a node to the zonelist. 2217 */ 2218static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, 2219 int nr_zones, enum zone_type zone_type) 2220{ 2221 struct zone *zone; 2222 2223 BUG_ON(zone_type >= MAX_NR_ZONES); 2224 zone_type++; 2225 2226 do { 2227 zone_type--; 2228 zone = pgdat->node_zones + zone_type; 2229 if (populated_zone(zone)) { 2230 zoneref_set_zone(zone, 2231 &zonelist->_zonerefs[nr_zones++]); 2232 check_highest_zone(zone_type); 2233 } 2234 2235 } while (zone_type); 2236 return nr_zones; 2237} 2238 2239 2240/* 2241 * zonelist_order: 2242 * 0 = automatic detection of better ordering. 2243 * 1 = order by ([node] distance, -zonetype) 2244 * 2 = order by (-zonetype, [node] distance) 2245 * 2246 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create 2247 * the same zonelist. So only NUMA can configure this param. 2248 */ 2249#define ZONELIST_ORDER_DEFAULT 0 2250#define ZONELIST_ORDER_NODE 1 2251#define ZONELIST_ORDER_ZONE 2 2252 2253/* zonelist order in the kernel. 2254 * set_zonelist_order() will set this to NODE or ZONE. 2255 */ 2256static int current_zonelist_order = ZONELIST_ORDER_DEFAULT; 2257static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"}; 2258 2259 2260#ifdef CONFIG_NUMA 2261/* The value user specified ....changed by config */ 2262static int user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2263/* string for sysctl */ 2264#define NUMA_ZONELIST_ORDER_LEN 16 2265char numa_zonelist_order[16] = "default"; 2266 2267/* 2268 * interface for configure zonelist ordering. 2269 * command line option "numa_zonelist_order" 2270 * = "[dD]efault - default, automatic configuration. 2271 * = "[nN]ode - order by node locality, then by zone within node 2272 * = "[zZ]one - order by zone, then by locality within zone 2273 */ 2274 2275static int __parse_numa_zonelist_order(char *s) 2276{ 2277 if (*s == 'd' || *s == 'D') { 2278 user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2279 } else if (*s == 'n' || *s == 'N') { 2280 user_zonelist_order = ZONELIST_ORDER_NODE; 2281 } else if (*s == 'z' || *s == 'Z') { 2282 user_zonelist_order = ZONELIST_ORDER_ZONE; 2283 } else { 2284 printk(KERN_WARNING 2285 "Ignoring invalid numa_zonelist_order value: " 2286 "%s\n", s); 2287 return -EINVAL; 2288 } 2289 return 0; 2290} 2291 2292static __init int setup_numa_zonelist_order(char *s) 2293{ 2294 if (s) 2295 return __parse_numa_zonelist_order(s); 2296 return 0; 2297} 2298early_param("numa_zonelist_order", setup_numa_zonelist_order); 2299 2300/* 2301 * sysctl handler for numa_zonelist_order 2302 */ 2303int numa_zonelist_order_handler(ctl_table *table, int write, 2304 struct file *file, void __user *buffer, size_t *length, 2305 loff_t *ppos) 2306{ 2307 char saved_string[NUMA_ZONELIST_ORDER_LEN]; 2308 int ret; 2309 2310 if (write) 2311 strncpy(saved_string, (char*)table->data, 2312 NUMA_ZONELIST_ORDER_LEN); 2313 ret = proc_dostring(table, write, file, buffer, length, ppos); 2314 if (ret) 2315 return ret; 2316 if (write) { 2317 int oldval = user_zonelist_order; 2318 if (__parse_numa_zonelist_order((char*)table->data)) { 2319 /* 2320 * bogus value. restore saved string 2321 */ 2322 strncpy((char*)table->data, saved_string, 2323 NUMA_ZONELIST_ORDER_LEN); 2324 user_zonelist_order = oldval; 2325 } else if (oldval != user_zonelist_order) 2326 build_all_zonelists(); 2327 } 2328 return 0; 2329} 2330 2331 2332#define MAX_NODE_LOAD (nr_online_nodes) 2333static int node_load[MAX_NUMNODES]; 2334 2335/** 2336 * find_next_best_node - find the next node that should appear in a given node's fallback list 2337 * @node: node whose fallback list we're appending 2338 * @used_node_mask: nodemask_t of already used nodes 2339 * 2340 * We use a number of factors to determine which is the next node that should 2341 * appear on a given node's fallback list. The node should not have appeared 2342 * already in @node's fallback list, and it should be the next closest node 2343 * according to the distance array (which contains arbitrary distance values 2344 * from each node to each node in the system), and should also prefer nodes 2345 * with no CPUs, since presumably they'll have very little allocation pressure 2346 * on them otherwise. 2347 * It returns -1 if no node is found. 2348 */ 2349static int find_next_best_node(int node, nodemask_t *used_node_mask) 2350{ 2351 int n, val; 2352 int min_val = INT_MAX; 2353 int best_node = -1; 2354 const struct cpumask *tmp = cpumask_of_node(0); 2355 2356 /* Use the local node if we haven't already */ 2357 if (!node_isset(node, *used_node_mask)) { 2358 node_set(node, *used_node_mask); 2359 return node; 2360 } 2361 2362 for_each_node_state(n, N_HIGH_MEMORY) { 2363 2364 /* Don't want a node to appear more than once */ 2365 if (node_isset(n, *used_node_mask)) 2366 continue; 2367 2368 /* Use the distance array to find the distance */ 2369 val = node_distance(node, n); 2370 2371 /* Penalize nodes under us ("prefer the next node") */ 2372 val += (n < node); 2373 2374 /* Give preference to headless and unused nodes */ 2375 tmp = cpumask_of_node(n); 2376 if (!cpumask_empty(tmp)) 2377 val += PENALTY_FOR_NODE_WITH_CPUS; 2378 2379 /* Slight preference for less loaded node */ 2380 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 2381 val += node_load[n]; 2382 2383 if (val < min_val) { 2384 min_val = val; 2385 best_node = n; 2386 } 2387 } 2388 2389 if (best_node >= 0) 2390 node_set(best_node, *used_node_mask); 2391 2392 return best_node; 2393} 2394 2395 2396/* 2397 * Build zonelists ordered by node and zones within node. 2398 * This results in maximum locality--normal zone overflows into local 2399 * DMA zone, if any--but risks exhausting DMA zone. 2400 */ 2401static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) 2402{ 2403 int j; 2404 struct zonelist *zonelist; 2405 2406 zonelist = &pgdat->node_zonelists[0]; 2407 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++) 2408 ; 2409 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2410 MAX_NR_ZONES - 1); 2411 zonelist->_zonerefs[j].zone = NULL; 2412 zonelist->_zonerefs[j].zone_idx = 0; 2413} 2414 2415/* 2416 * Build gfp_thisnode zonelists 2417 */ 2418static void build_thisnode_zonelists(pg_data_t *pgdat) 2419{ 2420 int j; 2421 struct zonelist *zonelist; 2422 2423 zonelist = &pgdat->node_zonelists[1]; 2424 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2425 zonelist->_zonerefs[j].zone = NULL; 2426 zonelist->_zonerefs[j].zone_idx = 0; 2427} 2428 2429/* 2430 * Build zonelists ordered by zone and nodes within zones. 2431 * This results in conserving DMA zone[s] until all Normal memory is 2432 * exhausted, but results in overflowing to remote node while memory 2433 * may still exist in local DMA zone. 2434 */ 2435static int node_order[MAX_NUMNODES]; 2436 2437static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) 2438{ 2439 int pos, j, node; 2440 int zone_type; /* needs to be signed */ 2441 struct zone *z; 2442 struct zonelist *zonelist; 2443 2444 zonelist = &pgdat->node_zonelists[0]; 2445 pos = 0; 2446 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) { 2447 for (j = 0; j < nr_nodes; j++) { 2448 node = node_order[j]; 2449 z = &NODE_DATA(node)->node_zones[zone_type]; 2450 if (populated_zone(z)) { 2451 zoneref_set_zone(z, 2452 &zonelist->_zonerefs[pos++]); 2453 check_highest_zone(zone_type); 2454 } 2455 } 2456 } 2457 zonelist->_zonerefs[pos].zone = NULL; 2458 zonelist->_zonerefs[pos].zone_idx = 0; 2459} 2460 2461static int default_zonelist_order(void) 2462{ 2463 int nid, zone_type; 2464 unsigned long low_kmem_size,total_size; 2465 struct zone *z; 2466 int average_size; 2467 /* 2468 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem. 2469 * If they are really small and used heavily, the system can fall 2470 * into OOM very easily. 2471 * This function detect ZONE_DMA/DMA32 size and confgigures zone order. 2472 */ 2473 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */ 2474 low_kmem_size = 0; 2475 total_size = 0; 2476 for_each_online_node(nid) { 2477 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2478 z = &NODE_DATA(nid)->node_zones[zone_type]; 2479 if (populated_zone(z)) { 2480 if (zone_type < ZONE_NORMAL) 2481 low_kmem_size += z->present_pages; 2482 total_size += z->present_pages; 2483 } 2484 } 2485 } 2486 if (!low_kmem_size || /* there are no DMA area. */ 2487 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */ 2488 return ZONELIST_ORDER_NODE; 2489 /* 2490 * look into each node's config. 2491 * If there is a node whose DMA/DMA32 memory is very big area on 2492 * local memory, NODE_ORDER may be suitable. 2493 */ 2494 average_size = total_size / 2495 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1); 2496 for_each_online_node(nid) { 2497 low_kmem_size = 0; 2498 total_size = 0; 2499 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2500 z = &NODE_DATA(nid)->node_zones[zone_type]; 2501 if (populated_zone(z)) { 2502 if (zone_type < ZONE_NORMAL) 2503 low_kmem_size += z->present_pages; 2504 total_size += z->present_pages; 2505 } 2506 } 2507 if (low_kmem_size && 2508 total_size > average_size && /* ignore small node */ 2509 low_kmem_size > total_size * 70/100) 2510 return ZONELIST_ORDER_NODE; 2511 } 2512 return ZONELIST_ORDER_ZONE; 2513} 2514 2515static void set_zonelist_order(void) 2516{ 2517 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT) 2518 current_zonelist_order = default_zonelist_order(); 2519 else 2520 current_zonelist_order = user_zonelist_order; 2521} 2522 2523static void build_zonelists(pg_data_t *pgdat) 2524{ 2525 int j, node, load; 2526 enum zone_type i; 2527 nodemask_t used_mask; 2528 int local_node, prev_node; 2529 struct zonelist *zonelist; 2530 int order = current_zonelist_order; 2531 2532 /* initialize zonelists */ 2533 for (i = 0; i < MAX_ZONELISTS; i++) { 2534 zonelist = pgdat->node_zonelists + i; 2535 zonelist->_zonerefs[0].zone = NULL; 2536 zonelist->_zonerefs[0].zone_idx = 0; 2537 } 2538 2539 /* NUMA-aware ordering of nodes */ 2540 local_node = pgdat->node_id; 2541 load = nr_online_nodes; 2542 prev_node = local_node; 2543 nodes_clear(used_mask); 2544 2545 memset(node_order, 0, sizeof(node_order)); 2546 j = 0; 2547 2548 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 2549 int distance = node_distance(local_node, node); 2550 2551 /* 2552 * If another node is sufficiently far away then it is better 2553 * to reclaim pages in a zone before going off node. 2554 */ 2555 if (distance > RECLAIM_DISTANCE) 2556 zone_reclaim_mode = 1; 2557 2558 /* 2559 * We don't want to pressure a particular node. 2560 * So adding penalty to the first node in same 2561 * distance group to make it round-robin. 2562 */ 2563 if (distance != node_distance(local_node, prev_node)) 2564 node_load[node] = load; 2565 2566 prev_node = node; 2567 load--; 2568 if (order == ZONELIST_ORDER_NODE) 2569 build_zonelists_in_node_order(pgdat, node); 2570 else 2571 node_order[j++] = node; /* remember order */ 2572 } 2573 2574 if (order == ZONELIST_ORDER_ZONE) { 2575 /* calculate node order -- i.e., DMA last! */ 2576 build_zonelists_in_zone_order(pgdat, j); 2577 } 2578 2579 build_thisnode_zonelists(pgdat); 2580} 2581 2582/* Construct the zonelist performance cache - see further mmzone.h */ 2583static void build_zonelist_cache(pg_data_t *pgdat) 2584{ 2585 struct zonelist *zonelist; 2586 struct zonelist_cache *zlc; 2587 struct zoneref *z; 2588 2589 zonelist = &pgdat->node_zonelists[0]; 2590 zonelist->zlcache_ptr = zlc = &zonelist->zlcache; 2591 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 2592 for (z = zonelist->_zonerefs; z->zone; z++) 2593 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z); 2594} 2595 2596 2597#else /* CONFIG_NUMA */ 2598 2599static void set_zonelist_order(void) 2600{ 2601 current_zonelist_order = ZONELIST_ORDER_ZONE; 2602} 2603 2604static void build_zonelists(pg_data_t *pgdat) 2605{ 2606 int node, local_node; 2607 enum zone_type j; 2608 struct zonelist *zonelist; 2609 2610 local_node = pgdat->node_id; 2611 2612 zonelist = &pgdat->node_zonelists[0]; 2613 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2614 2615 /* 2616 * Now we build the zonelist so that it contains the zones 2617 * of all the other nodes. 2618 * We don't want to pressure a particular node, so when 2619 * building the zones for node N, we make sure that the 2620 * zones coming right after the local ones are those from 2621 * node N+1 (modulo N) 2622 */ 2623 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 2624 if (!node_online(node)) 2625 continue; 2626 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2627 MAX_NR_ZONES - 1); 2628 } 2629 for (node = 0; node < local_node; node++) { 2630 if (!node_online(node)) 2631 continue; 2632 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2633 MAX_NR_ZONES - 1); 2634 } 2635 2636 zonelist->_zonerefs[j].zone = NULL; 2637 zonelist->_zonerefs[j].zone_idx = 0; 2638} 2639 2640/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ 2641static void build_zonelist_cache(pg_data_t *pgdat) 2642{ 2643 pgdat->node_zonelists[0].zlcache_ptr = NULL; 2644} 2645 2646#endif /* CONFIG_NUMA */ 2647 2648/* return values int ....just for stop_machine() */ 2649static int __build_all_zonelists(void *dummy) 2650{ 2651 int nid; 2652 2653#ifdef CONFIG_NUMA 2654 memset(node_load, 0, sizeof(node_load)); 2655#endif 2656 for_each_online_node(nid) { 2657 pg_data_t *pgdat = NODE_DATA(nid); 2658 2659 build_zonelists(pgdat); 2660 build_zonelist_cache(pgdat); 2661 } 2662 return 0; 2663} 2664 2665void build_all_zonelists(void) 2666{ 2667 set_zonelist_order(); 2668 2669 if (system_state == SYSTEM_BOOTING) { 2670 __build_all_zonelists(NULL); 2671 mminit_verify_zonelist(); 2672 cpuset_init_current_mems_allowed(); 2673 } else { 2674 /* we have to stop all cpus to guarantee there is no user 2675 of zonelist */ 2676 stop_machine(__build_all_zonelists, NULL, NULL); 2677 /* cpuset refresh routine should be here */ 2678 } 2679 vm_total_pages = nr_free_pagecache_pages(); 2680 /* 2681 * Disable grouping by mobility if the number of pages in the 2682 * system is too low to allow the mechanism to work. It would be 2683 * more accurate, but expensive to check per-zone. This check is 2684 * made on memory-hotadd so a system can start with mobility 2685 * disabled and enable it later 2686 */ 2687 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) 2688 page_group_by_mobility_disabled = 1; 2689 else 2690 page_group_by_mobility_disabled = 0; 2691 2692 printk("Built %i zonelists in %s order, mobility grouping %s. " 2693 "Total pages: %ld\n", 2694 nr_online_nodes, 2695 zonelist_order_name[current_zonelist_order], 2696 page_group_by_mobility_disabled ? "off" : "on", 2697 vm_total_pages); 2698#ifdef CONFIG_NUMA 2699 printk("Policy zone: %s\n", zone_names[policy_zone]); 2700#endif 2701} 2702 2703/* 2704 * Helper functions to size the waitqueue hash table. 2705 * Essentially these want to choose hash table sizes sufficiently 2706 * large so that collisions trying to wait on pages are rare. 2707 * But in fact, the number of active page waitqueues on typical 2708 * systems is ridiculously low, less than 200. So this is even 2709 * conservative, even though it seems large. 2710 * 2711 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 2712 * waitqueues, i.e. the size of the waitq table given the number of pages. 2713 */ 2714#define PAGES_PER_WAITQUEUE 256 2715 2716#ifndef CONFIG_MEMORY_HOTPLUG 2717static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2718{ 2719 unsigned long size = 1; 2720 2721 pages /= PAGES_PER_WAITQUEUE; 2722 2723 while (size < pages) 2724 size <<= 1; 2725 2726 /* 2727 * Once we have dozens or even hundreds of threads sleeping 2728 * on IO we've got bigger problems than wait queue collision. 2729 * Limit the size of the wait table to a reasonable size. 2730 */ 2731 size = min(size, 4096UL); 2732 2733 return max(size, 4UL); 2734} 2735#else 2736/* 2737 * A zone's size might be changed by hot-add, so it is not possible to determine 2738 * a suitable size for its wait_table. So we use the maximum size now. 2739 * 2740 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: 2741 * 2742 * i386 (preemption config) : 4096 x 16 = 64Kbyte. 2743 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. 2744 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. 2745 * 2746 * The maximum entries are prepared when a zone's memory is (512K + 256) pages 2747 * or more by the traditional way. (See above). It equals: 2748 * 2749 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. 2750 * ia64(16K page size) : = ( 8G + 4M)byte. 2751 * powerpc (64K page size) : = (32G +16M)byte. 2752 */ 2753static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2754{ 2755 return 4096UL; 2756} 2757#endif 2758 2759/* 2760 * This is an integer logarithm so that shifts can be used later 2761 * to extract the more random high bits from the multiplicative 2762 * hash function before the remainder is taken. 2763 */ 2764static inline unsigned long wait_table_bits(unsigned long size) 2765{ 2766 return ffz(~size); 2767} 2768 2769#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) 2770 2771/* 2772 * Mark a number of pageblocks as MIGRATE_RESERVE. The number 2773 * of blocks reserved is based on min_wmark_pages(zone). The memory within 2774 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes 2775 * higher will lead to a bigger reserve which will get freed as contiguous 2776 * blocks as reclaim kicks in 2777 */ 2778static void setup_zone_migrate_reserve(struct zone *zone) 2779{ 2780 unsigned long start_pfn, pfn, end_pfn; 2781 struct page *page; 2782 unsigned long reserve, block_migratetype; 2783 2784 /* Get the start pfn, end pfn and the number of blocks to reserve */ 2785 start_pfn = zone->zone_start_pfn; 2786 end_pfn = start_pfn + zone->spanned_pages; 2787 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >> 2788 pageblock_order; 2789 2790 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 2791 if (!pfn_valid(pfn)) 2792 continue; 2793 page = pfn_to_page(pfn); 2794 2795 /* Watch out for overlapping nodes */ 2796 if (page_to_nid(page) != zone_to_nid(zone)) 2797 continue; 2798 2799 /* Blocks with reserved pages will never free, skip them. */ 2800 if (PageReserved(page)) 2801 continue; 2802 2803 block_migratetype = get_pageblock_migratetype(page); 2804 2805 /* If this block is reserved, account for it */ 2806 if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) { 2807 reserve--; 2808 continue; 2809 } 2810 2811 /* Suitable for reserving if this block is movable */ 2812 if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) { 2813 set_pageblock_migratetype(page, MIGRATE_RESERVE); 2814 move_freepages_block(zone, page, MIGRATE_RESERVE); 2815 reserve--; 2816 continue; 2817 } 2818 2819 /* 2820 * If the reserve is met and this is a previous reserved block, 2821 * take it back 2822 */ 2823 if (block_migratetype == MIGRATE_RESERVE) { 2824 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 2825 move_freepages_block(zone, page, MIGRATE_MOVABLE); 2826 } 2827 } 2828} 2829 2830/* 2831 * Initially all pages are reserved - free ones are freed 2832 * up by free_all_bootmem() once the early boot process is 2833 * done. Non-atomic initialization, single-pass. 2834 */ 2835void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 2836 unsigned long start_pfn, enum memmap_context context) 2837{ 2838 struct page *page; 2839 unsigned long end_pfn = start_pfn + size; 2840 unsigned long pfn; 2841 struct zone *z; 2842 2843 if (highest_memmap_pfn < end_pfn - 1) 2844 highest_memmap_pfn = end_pfn - 1; 2845 2846 z = &NODE_DATA(nid)->node_zones[zone]; 2847 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 2848 /* 2849 * There can be holes in boot-time mem_map[]s 2850 * handed to this function. They do not 2851 * exist on hotplugged memory. 2852 */ 2853 if (context == MEMMAP_EARLY) { 2854 if (!early_pfn_valid(pfn)) 2855 continue; 2856 if (!early_pfn_in_nid(pfn, nid)) 2857 continue; 2858 } 2859 page = pfn_to_page(pfn); 2860 set_page_links(page, zone, nid, pfn); 2861 mminit_verify_page_links(page, zone, nid, pfn); 2862 init_page_count(page); 2863 reset_page_mapcount(page); 2864 SetPageReserved(page); 2865 /* 2866 * Mark the block movable so that blocks are reserved for 2867 * movable at startup. This will force kernel allocations 2868 * to reserve their blocks rather than leaking throughout 2869 * the address space during boot when many long-lived 2870 * kernel allocations are made. Later some blocks near 2871 * the start are marked MIGRATE_RESERVE by 2872 * setup_zone_migrate_reserve() 2873 * 2874 * bitmap is created for zone's valid pfn range. but memmap 2875 * can be created for invalid pages (for alignment) 2876 * check here not to call set_pageblock_migratetype() against 2877 * pfn out of zone. 2878 */ 2879 if ((z->zone_start_pfn <= pfn) 2880 && (pfn < z->zone_start_pfn + z->spanned_pages) 2881 && !(pfn & (pageblock_nr_pages - 1))) 2882 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 2883 2884 INIT_LIST_HEAD(&page->lru); 2885#ifdef WANT_PAGE_VIRTUAL 2886 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 2887 if (!is_highmem_idx(zone)) 2888 set_page_address(page, __va(pfn << PAGE_SHIFT)); 2889#endif 2890 } 2891} 2892 2893static void __meminit zone_init_free_lists(struct zone *zone) 2894{ 2895 int order, t; 2896 for_each_migratetype_order(order, t) { 2897 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); 2898 zone->free_area[order].nr_free = 0; 2899 } 2900} 2901 2902#ifndef __HAVE_ARCH_MEMMAP_INIT 2903#define memmap_init(size, nid, zone, start_pfn) \ 2904 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) 2905#endif 2906 2907static int zone_batchsize(struct zone *zone) 2908{ 2909#ifdef CONFIG_MMU 2910 int batch; 2911 2912 /* 2913 * The per-cpu-pages pools are set to around 1000th of the 2914 * size of the zone. But no more than 1/2 of a meg. 2915 * 2916 * OK, so we don't know how big the cache is. So guess. 2917 */ 2918 batch = zone->present_pages / 1024; 2919 if (batch * PAGE_SIZE > 512 * 1024) 2920 batch = (512 * 1024) / PAGE_SIZE; 2921 batch /= 4; /* We effectively *= 4 below */ 2922 if (batch < 1) 2923 batch = 1; 2924 2925 /* 2926 * Clamp the batch to a 2^n - 1 value. Having a power 2927 * of 2 value was found to be more likely to have 2928 * suboptimal cache aliasing properties in some cases. 2929 * 2930 * For example if 2 tasks are alternately allocating 2931 * batches of pages, one task can end up with a lot 2932 * of pages of one half of the possible page colors 2933 * and the other with pages of the other colors. 2934 */ 2935 batch = rounddown_pow_of_two(batch + batch/2) - 1; 2936 2937 return batch; 2938 2939#else 2940 /* The deferral and batching of frees should be suppressed under NOMMU 2941 * conditions. 2942 * 2943 * The problem is that NOMMU needs to be able to allocate large chunks 2944 * of contiguous memory as there's no hardware page translation to 2945 * assemble apparent contiguous memory from discontiguous pages. 2946 * 2947 * Queueing large contiguous runs of pages for batching, however, 2948 * causes the pages to actually be freed in smaller chunks. As there 2949 * can be a significant delay between the individual batches being 2950 * recycled, this leads to the once large chunks of space being 2951 * fragmented and becoming unavailable for high-order allocations. 2952 */ 2953 return 0; 2954#endif 2955} 2956 2957static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 2958{ 2959 struct per_cpu_pages *pcp; 2960 2961 memset(p, 0, sizeof(*p)); 2962 2963 pcp = &p->pcp; 2964 pcp->count = 0; 2965 pcp->high = 6 * batch; 2966 pcp->batch = max(1UL, 1 * batch); 2967 INIT_LIST_HEAD(&pcp->list); 2968} 2969 2970/* 2971 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist 2972 * to the value high for the pageset p. 2973 */ 2974 2975static void setup_pagelist_highmark(struct per_cpu_pageset *p, 2976 unsigned long high) 2977{ 2978 struct per_cpu_pages *pcp; 2979 2980 pcp = &p->pcp; 2981 pcp->high = high; 2982 pcp->batch = max(1UL, high/4); 2983 if ((high/4) > (PAGE_SHIFT * 8)) 2984 pcp->batch = PAGE_SHIFT * 8; 2985} 2986 2987 2988#ifdef CONFIG_NUMA 2989/* 2990 * Boot pageset table. One per cpu which is going to be used for all 2991 * zones and all nodes. The parameters will be set in such a way 2992 * that an item put on a list will immediately be handed over to 2993 * the buddy list. This is safe since pageset manipulation is done 2994 * with interrupts disabled. 2995 * 2996 * Some NUMA counter updates may also be caught by the boot pagesets. 2997 * 2998 * The boot_pagesets must be kept even after bootup is complete for 2999 * unused processors and/or zones. They do play a role for bootstrapping 3000 * hotplugged processors. 3001 * 3002 * zoneinfo_show() and maybe other functions do 3003 * not check if the processor is online before following the pageset pointer. 3004 * Other parts of the kernel may not check if the zone is available. 3005 */ 3006static struct per_cpu_pageset boot_pageset[NR_CPUS]; 3007 3008/* 3009 * Dynamically allocate memory for the 3010 * per cpu pageset array in struct zone. 3011 */ 3012static int __cpuinit process_zones(int cpu) 3013{ 3014 struct zone *zone, *dzone; 3015 int node = cpu_to_node(cpu); 3016 3017 node_set_state(node, N_CPU); /* this node has a cpu */ 3018 3019 for_each_populated_zone(zone) { 3020 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset), 3021 GFP_KERNEL, node); 3022 if (!zone_pcp(zone, cpu)) 3023 goto bad; 3024 3025 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone)); 3026 3027 if (percpu_pagelist_fraction) 3028 setup_pagelist_highmark(zone_pcp(zone, cpu), 3029 (zone->present_pages / percpu_pagelist_fraction)); 3030 } 3031 3032 return 0; 3033bad: 3034 for_each_zone(dzone) { 3035 if (!populated_zone(dzone)) 3036 continue; 3037 if (dzone == zone) 3038 break; 3039 kfree(zone_pcp(dzone, cpu)); 3040 zone_pcp(dzone, cpu) = &boot_pageset[cpu]; 3041 } 3042 return -ENOMEM; 3043} 3044 3045static inline void free_zone_pagesets(int cpu) 3046{ 3047 struct zone *zone; 3048 3049 for_each_zone(zone) { 3050 struct per_cpu_pageset *pset = zone_pcp(zone, cpu); 3051 3052 /* Free per_cpu_pageset if it is slab allocated */ 3053 if (pset != &boot_pageset[cpu]) 3054 kfree(pset); 3055 zone_pcp(zone, cpu) = &boot_pageset[cpu]; 3056 } 3057} 3058 3059static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb, 3060 unsigned long action, 3061 void *hcpu) 3062{ 3063 int cpu = (long)hcpu; 3064 int ret = NOTIFY_OK; 3065 3066 switch (action) { 3067 case CPU_UP_PREPARE: 3068 case CPU_UP_PREPARE_FROZEN: 3069 if (process_zones(cpu)) 3070 ret = NOTIFY_BAD; 3071 break; 3072 case CPU_UP_CANCELED: 3073 case CPU_UP_CANCELED_FROZEN: 3074 case CPU_DEAD: 3075 case CPU_DEAD_FROZEN: 3076 free_zone_pagesets(cpu); 3077 break; 3078 default: 3079 break; 3080 } 3081 return ret; 3082} 3083 3084static struct notifier_block __cpuinitdata pageset_notifier = 3085 { &pageset_cpuup_callback, NULL, 0 }; 3086 3087void __init setup_per_cpu_pageset(void) 3088{ 3089 int err; 3090 3091 /* Initialize per_cpu_pageset for cpu 0. 3092 * A cpuup callback will do this for every cpu 3093 * as it comes online 3094 */ 3095 err = process_zones(smp_processor_id()); 3096 BUG_ON(err); 3097 register_cpu_notifier(&pageset_notifier); 3098} 3099 3100#endif 3101 3102static noinline __init_refok 3103int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 3104{ 3105 int i; 3106 struct pglist_data *pgdat = zone->zone_pgdat; 3107 size_t alloc_size; 3108 3109 /* 3110 * The per-page waitqueue mechanism uses hashed waitqueues 3111 * per zone. 3112 */ 3113 zone->wait_table_hash_nr_entries = 3114 wait_table_hash_nr_entries(zone_size_pages); 3115 zone->wait_table_bits = 3116 wait_table_bits(zone->wait_table_hash_nr_entries); 3117 alloc_size = zone->wait_table_hash_nr_entries 3118 * sizeof(wait_queue_head_t); 3119 3120 if (!slab_is_available()) { 3121 zone->wait_table = (wait_queue_head_t *) 3122 alloc_bootmem_node(pgdat, alloc_size); 3123 } else { 3124 /* 3125 * This case means that a zone whose size was 0 gets new memory 3126 * via memory hot-add. 3127 * But it may be the case that a new node was hot-added. In 3128 * this case vmalloc() will not be able to use this new node's 3129 * memory - this wait_table must be initialized to use this new 3130 * node itself as well. 3131 * To use this new node's memory, further consideration will be 3132 * necessary. 3133 */ 3134 zone->wait_table = vmalloc(alloc_size); 3135 } 3136 if (!zone->wait_table) 3137 return -ENOMEM; 3138 3139 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i) 3140 init_waitqueue_head(zone->wait_table + i); 3141 3142 return 0; 3143} 3144 3145static int __zone_pcp_update(void *data) 3146{ 3147 struct zone *zone = data; 3148 int cpu; 3149 unsigned long batch = zone_batchsize(zone), flags; 3150 3151 for (cpu = 0; cpu < NR_CPUS; cpu++) { 3152 struct per_cpu_pageset *pset; 3153 struct per_cpu_pages *pcp; 3154 3155 pset = zone_pcp(zone, cpu); 3156 pcp = &pset->pcp; 3157 3158 local_irq_save(flags); 3159 free_pages_bulk(zone, pcp->count, &pcp->list, 0); 3160 setup_pageset(pset, batch); 3161 local_irq_restore(flags); 3162 } 3163 return 0; 3164} 3165 3166void zone_pcp_update(struct zone *zone) 3167{ 3168 stop_machine(__zone_pcp_update, zone, NULL); 3169} 3170 3171static __meminit void zone_pcp_init(struct zone *zone) 3172{ 3173 int cpu; 3174 unsigned long batch = zone_batchsize(zone); 3175 3176 for (cpu = 0; cpu < NR_CPUS; cpu++) { 3177#ifdef CONFIG_NUMA 3178 /* Early boot. Slab allocator not functional yet */ 3179 zone_pcp(zone, cpu) = &boot_pageset[cpu]; 3180 setup_pageset(&boot_pageset[cpu],0); 3181#else 3182 setup_pageset(zone_pcp(zone,cpu), batch); 3183#endif 3184 } 3185 if (zone->present_pages) 3186 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", 3187 zone->name, zone->present_pages, batch); 3188} 3189 3190__meminit int init_currently_empty_zone(struct zone *zone, 3191 unsigned long zone_start_pfn, 3192 unsigned long size, 3193 enum memmap_context context) 3194{ 3195 struct pglist_data *pgdat = zone->zone_pgdat; 3196 int ret; 3197 ret = zone_wait_table_init(zone, size); 3198 if (ret) 3199 return ret; 3200 pgdat->nr_zones = zone_idx(zone) + 1; 3201 3202 zone->zone_start_pfn = zone_start_pfn; 3203 3204 mminit_dprintk(MMINIT_TRACE, "memmap_init", 3205 "Initialising map node %d zone %lu pfns %lu -> %lu\n", 3206 pgdat->node_id, 3207 (unsigned long)zone_idx(zone), 3208 zone_start_pfn, (zone_start_pfn + size)); 3209 3210 zone_init_free_lists(zone); 3211 3212 return 0; 3213} 3214 3215#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3216/* 3217 * Basic iterator support. Return the first range of PFNs for a node 3218 * Note: nid == MAX_NUMNODES returns first region regardless of node 3219 */ 3220static int __meminit first_active_region_index_in_nid(int nid) 3221{ 3222 int i; 3223 3224 for (i = 0; i < nr_nodemap_entries; i++) 3225 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid) 3226 return i; 3227 3228 return -1; 3229} 3230 3231/* 3232 * Basic iterator support. Return the next active range of PFNs for a node 3233 * Note: nid == MAX_NUMNODES returns next region regardless of node 3234 */ 3235static int __meminit next_active_region_index_in_nid(int index, int nid) 3236{ 3237 for (index = index + 1; index < nr_nodemap_entries; index++) 3238 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid) 3239 return index; 3240 3241 return -1; 3242} 3243 3244#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID 3245/* 3246 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. 3247 * Architectures may implement their own version but if add_active_range() 3248 * was used and there are no special requirements, this is a convenient 3249 * alternative 3250 */ 3251int __meminit __early_pfn_to_nid(unsigned long pfn) 3252{ 3253 int i; 3254 3255 for (i = 0; i < nr_nodemap_entries; i++) { 3256 unsigned long start_pfn = early_node_map[i].start_pfn; 3257 unsigned long end_pfn = early_node_map[i].end_pfn; 3258 3259 if (start_pfn <= pfn && pfn < end_pfn) 3260 return early_node_map[i].nid; 3261 } 3262 /* This is a memory hole */ 3263 return -1; 3264} 3265#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ 3266 3267int __meminit early_pfn_to_nid(unsigned long pfn) 3268{ 3269 int nid; 3270 3271 nid = __early_pfn_to_nid(pfn); 3272 if (nid >= 0) 3273 return nid; 3274 /* just returns 0 */ 3275 return 0; 3276} 3277 3278#ifdef CONFIG_NODES_SPAN_OTHER_NODES 3279bool __meminit early_pfn_in_nid(unsigned long pfn, int node) 3280{ 3281 int nid; 3282 3283 nid = __early_pfn_to_nid(pfn); 3284 if (nid >= 0 && nid != node) 3285 return false; 3286 return true; 3287} 3288#endif 3289 3290/* Basic iterator support to walk early_node_map[] */ 3291#define for_each_active_range_index_in_nid(i, nid) \ 3292 for (i = first_active_region_index_in_nid(nid); i != -1; \ 3293 i = next_active_region_index_in_nid(i, nid)) 3294 3295/** 3296 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range 3297 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. 3298 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node 3299 * 3300 * If an architecture guarantees that all ranges registered with 3301 * add_active_ranges() contain no holes and may be freed, this 3302 * this function may be used instead of calling free_bootmem() manually. 3303 */ 3304void __init free_bootmem_with_active_regions(int nid, 3305 unsigned long max_low_pfn) 3306{ 3307 int i; 3308 3309 for_each_active_range_index_in_nid(i, nid) { 3310 unsigned long size_pages = 0; 3311 unsigned long end_pfn = early_node_map[i].end_pfn; 3312 3313 if (early_node_map[i].start_pfn >= max_low_pfn) 3314 continue; 3315 3316 if (end_pfn > max_low_pfn) 3317 end_pfn = max_low_pfn; 3318 3319 size_pages = end_pfn - early_node_map[i].start_pfn; 3320 free_bootmem_node(NODE_DATA(early_node_map[i].nid), 3321 PFN_PHYS(early_node_map[i].start_pfn), 3322 size_pages << PAGE_SHIFT); 3323 } 3324} 3325 3326void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data) 3327{ 3328 int i; 3329 int ret; 3330 3331 for_each_active_range_index_in_nid(i, nid) { 3332 ret = work_fn(early_node_map[i].start_pfn, 3333 early_node_map[i].end_pfn, data); 3334 if (ret) 3335 break; 3336 } 3337} 3338/** 3339 * sparse_memory_present_with_active_regions - Call memory_present for each active range 3340 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. 3341 * 3342 * If an architecture guarantees that all ranges registered with 3343 * add_active_ranges() contain no holes and may be freed, this 3344 * function may be used instead of calling memory_present() manually. 3345 */ 3346void __init sparse_memory_present_with_active_regions(int nid) 3347{ 3348 int i; 3349 3350 for_each_active_range_index_in_nid(i, nid) 3351 memory_present(early_node_map[i].nid, 3352 early_node_map[i].start_pfn, 3353 early_node_map[i].end_pfn); 3354} 3355 3356/** 3357 * get_pfn_range_for_nid - Return the start and end page frames for a node 3358 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. 3359 * @start_pfn: Passed by reference. On return, it will have the node start_pfn. 3360 * @end_pfn: Passed by reference. On return, it will have the node end_pfn. 3361 * 3362 * It returns the start and end page frame of a node based on information 3363 * provided by an arch calling add_active_range(). If called for a node 3364 * with no available memory, a warning is printed and the start and end 3365 * PFNs will be 0. 3366 */ 3367void __meminit get_pfn_range_for_nid(unsigned int nid, 3368 unsigned long *start_pfn, unsigned long *end_pfn) 3369{ 3370 int i; 3371 *start_pfn = -1UL; 3372 *end_pfn = 0; 3373 3374 for_each_active_range_index_in_nid(i, nid) { 3375 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn); 3376 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn); 3377 } 3378 3379 if (*start_pfn == -1UL) 3380 *start_pfn = 0; 3381} 3382 3383/* 3384 * This finds a zone that can be used for ZONE_MOVABLE pages. The 3385 * assumption is made that zones within a node are ordered in monotonic 3386 * increasing memory addresses so that the "highest" populated zone is used 3387 */ 3388static void __init find_usable_zone_for_movable(void) 3389{ 3390 int zone_index; 3391 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { 3392 if (zone_index == ZONE_MOVABLE) 3393 continue; 3394 3395 if (arch_zone_highest_possible_pfn[zone_index] > 3396 arch_zone_lowest_possible_pfn[zone_index]) 3397 break; 3398 } 3399 3400 VM_BUG_ON(zone_index == -1); 3401 movable_zone = zone_index; 3402} 3403 3404/* 3405 * The zone ranges provided by the architecture do not include ZONE_MOVABLE 3406 * because it is sized independant of architecture. Unlike the other zones, 3407 * the starting point for ZONE_MOVABLE is not fixed. It may be different 3408 * in each node depending on the size of each node and how evenly kernelcore 3409 * is distributed. This helper function adjusts the zone ranges 3410 * provided by the architecture for a given node by using the end of the 3411 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that 3412 * zones within a node are in order of monotonic increases memory addresses 3413 */ 3414static void __meminit adjust_zone_range_for_zone_movable(int nid, 3415 unsigned long zone_type, 3416 unsigned long node_start_pfn, 3417 unsigned long node_end_pfn, 3418 unsigned long *zone_start_pfn, 3419 unsigned long *zone_end_pfn) 3420{ 3421 /* Only adjust if ZONE_MOVABLE is on this node */ 3422 if (zone_movable_pfn[nid]) { 3423 /* Size ZONE_MOVABLE */ 3424 if (zone_type == ZONE_MOVABLE) { 3425 *zone_start_pfn = zone_movable_pfn[nid]; 3426 *zone_end_pfn = min(node_end_pfn, 3427 arch_zone_highest_possible_pfn[movable_zone]); 3428 3429 /* Adjust for ZONE_MOVABLE starting within this range */ 3430 } else if (*zone_start_pfn < zone_movable_pfn[nid] && 3431 *zone_end_pfn > zone_movable_pfn[nid]) { 3432 *zone_end_pfn = zone_movable_pfn[nid]; 3433 3434 /* Check if this whole range is within ZONE_MOVABLE */ 3435 } else if (*zone_start_pfn >= zone_movable_pfn[nid]) 3436 *zone_start_pfn = *zone_end_pfn; 3437 } 3438} 3439 3440/* 3441 * Return the number of pages a zone spans in a node, including holes 3442 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() 3443 */ 3444static unsigned long __meminit zone_spanned_pages_in_node(int nid, 3445 unsigned long zone_type, 3446 unsigned long *ignored) 3447{ 3448 unsigned long node_start_pfn, node_end_pfn; 3449 unsigned long zone_start_pfn, zone_end_pfn; 3450 3451 /* Get the start and end of the node and zone */ 3452 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3453 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; 3454 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; 3455 adjust_zone_range_for_zone_movable(nid, zone_type, 3456 node_start_pfn, node_end_pfn, 3457 &zone_start_pfn, &zone_end_pfn); 3458 3459 /* Check that this node has pages within the zone's required range */ 3460 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) 3461 return 0; 3462 3463 /* Move the zone boundaries inside the node if necessary */ 3464 zone_end_pfn = min(zone_end_pfn, node_end_pfn); 3465 zone_start_pfn = max(zone_start_pfn, node_start_pfn); 3466 3467 /* Return the spanned pages */ 3468 return zone_end_pfn - zone_start_pfn; 3469} 3470 3471/* 3472 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, 3473 * then all holes in the requested range will be accounted for. 3474 */ 3475static unsigned long __meminit __absent_pages_in_range(int nid, 3476 unsigned long range_start_pfn, 3477 unsigned long range_end_pfn) 3478{ 3479 int i = 0; 3480 unsigned long prev_end_pfn = 0, hole_pages = 0; 3481 unsigned long start_pfn; 3482 3483 /* Find the end_pfn of the first active range of pfns in the node */ 3484 i = first_active_region_index_in_nid(nid); 3485 if (i == -1) 3486 return 0; 3487 3488 prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 3489 3490 /* Account for ranges before physical memory on this node */ 3491 if (early_node_map[i].start_pfn > range_start_pfn) 3492 hole_pages = prev_end_pfn - range_start_pfn; 3493 3494 /* Find all holes for the zone within the node */ 3495 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) { 3496 3497 /* No need to continue if prev_end_pfn is outside the zone */ 3498 if (prev_end_pfn >= range_end_pfn) 3499 break; 3500 3501 /* Make sure the end of the zone is not within the hole */ 3502 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 3503 prev_end_pfn = max(prev_end_pfn, range_start_pfn); 3504 3505 /* Update the hole size cound and move on */ 3506 if (start_pfn > range_start_pfn) { 3507 BUG_ON(prev_end_pfn > start_pfn); 3508 hole_pages += start_pfn - prev_end_pfn; 3509 } 3510 prev_end_pfn = early_node_map[i].end_pfn; 3511 } 3512 3513 /* Account for ranges past physical memory on this node */ 3514 if (range_end_pfn > prev_end_pfn) 3515 hole_pages += range_end_pfn - 3516 max(range_start_pfn, prev_end_pfn); 3517 3518 return hole_pages; 3519} 3520 3521/** 3522 * absent_pages_in_range - Return number of page frames in holes within a range 3523 * @start_pfn: The start PFN to start searching for holes 3524 * @end_pfn: The end PFN to stop searching for holes 3525 * 3526 * It returns the number of pages frames in memory holes within a range. 3527 */ 3528unsigned long __init absent_pages_in_range(unsigned long start_pfn, 3529 unsigned long end_pfn) 3530{ 3531 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); 3532} 3533 3534/* Return the number of page frames in holes in a zone on a node */ 3535static unsigned long __meminit zone_absent_pages_in_node(int nid, 3536 unsigned long zone_type, 3537 unsigned long *ignored) 3538{ 3539 unsigned long node_start_pfn, node_end_pfn; 3540 unsigned long zone_start_pfn, zone_end_pfn; 3541 3542 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3543 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type], 3544 node_start_pfn); 3545 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type], 3546 node_end_pfn); 3547 3548 adjust_zone_range_for_zone_movable(nid, zone_type, 3549 node_start_pfn, node_end_pfn, 3550 &zone_start_pfn, &zone_end_pfn); 3551 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); 3552} 3553 3554#else 3555static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, 3556 unsigned long zone_type, 3557 unsigned long *zones_size) 3558{ 3559 return zones_size[zone_type]; 3560} 3561 3562static inline unsigned long __meminit zone_absent_pages_in_node(int nid, 3563 unsigned long zone_type, 3564 unsigned long *zholes_size) 3565{ 3566 if (!zholes_size) 3567 return 0; 3568 3569 return zholes_size[zone_type]; 3570} 3571 3572#endif 3573 3574static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, 3575 unsigned long *zones_size, unsigned long *zholes_size) 3576{ 3577 unsigned long realtotalpages, totalpages = 0; 3578 enum zone_type i; 3579 3580 for (i = 0; i < MAX_NR_ZONES; i++) 3581 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i, 3582 zones_size); 3583 pgdat->node_spanned_pages = totalpages; 3584 3585 realtotalpages = totalpages; 3586 for (i = 0; i < MAX_NR_ZONES; i++) 3587 realtotalpages -= 3588 zone_absent_pages_in_node(pgdat->node_id, i, 3589 zholes_size); 3590 pgdat->node_present_pages = realtotalpages; 3591 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, 3592 realtotalpages); 3593} 3594 3595#ifndef CONFIG_SPARSEMEM 3596/* 3597 * Calculate the size of the zone->blockflags rounded to an unsigned long 3598 * Start by making sure zonesize is a multiple of pageblock_order by rounding 3599 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally 3600 * round what is now in bits to nearest long in bits, then return it in 3601 * bytes. 3602 */ 3603static unsigned long __init usemap_size(unsigned long zonesize) 3604{ 3605 unsigned long usemapsize; 3606 3607 usemapsize = roundup(zonesize, pageblock_nr_pages); 3608 usemapsize = usemapsize >> pageblock_order; 3609 usemapsize *= NR_PAGEBLOCK_BITS; 3610 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); 3611 3612 return usemapsize / 8; 3613} 3614 3615static void __init setup_usemap(struct pglist_data *pgdat, 3616 struct zone *zone, unsigned long zonesize) 3617{ 3618 unsigned long usemapsize = usemap_size(zonesize); 3619 zone->pageblock_flags = NULL; 3620 if (usemapsize) 3621 zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize); 3622} 3623#else 3624static void inline setup_usemap(struct pglist_data *pgdat, 3625 struct zone *zone, unsigned long zonesize) {} 3626#endif /* CONFIG_SPARSEMEM */ 3627 3628#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 3629 3630/* Return a sensible default order for the pageblock size. */ 3631static inline int pageblock_default_order(void) 3632{ 3633 if (HPAGE_SHIFT > PAGE_SHIFT) 3634 return HUGETLB_PAGE_ORDER; 3635 3636 return MAX_ORDER-1; 3637} 3638 3639/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ 3640static inline void __init set_pageblock_order(unsigned int order) 3641{ 3642 /* Check that pageblock_nr_pages has not already been setup */ 3643 if (pageblock_order) 3644 return; 3645 3646 /* 3647 * Assume the largest contiguous order of interest is a huge page. 3648 * This value may be variable depending on boot parameters on IA64 3649 */ 3650 pageblock_order = order; 3651} 3652#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 3653 3654/* 3655 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() 3656 * and pageblock_default_order() are unused as pageblock_order is set 3657 * at compile-time. See include/linux/pageblock-flags.h for the values of 3658 * pageblock_order based on the kernel config 3659 */ 3660static inline int pageblock_default_order(unsigned int order) 3661{ 3662 return MAX_ORDER-1; 3663} 3664#define set_pageblock_order(x) do {} while (0) 3665 3666#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 3667 3668/* 3669 * Set up the zone data structures: 3670 * - mark all pages reserved 3671 * - mark all memory queues empty 3672 * - clear the memory bitmaps 3673 */ 3674static void __paginginit free_area_init_core(struct pglist_data *pgdat, 3675 unsigned long *zones_size, unsigned long *zholes_size) 3676{ 3677 enum zone_type j; 3678 int nid = pgdat->node_id; 3679 unsigned long zone_start_pfn = pgdat->node_start_pfn; 3680 int ret; 3681 3682 pgdat_resize_init(pgdat); 3683 pgdat->nr_zones = 0; 3684 init_waitqueue_head(&pgdat->kswapd_wait); 3685 pgdat->kswapd_max_order = 0; 3686 pgdat_page_cgroup_init(pgdat); 3687 3688 for (j = 0; j < MAX_NR_ZONES; j++) { 3689 struct zone *zone = pgdat->node_zones + j; 3690 unsigned long size, realsize, memmap_pages; 3691 enum lru_list l; 3692 3693 size = zone_spanned_pages_in_node(nid, j, zones_size); 3694 realsize = size - zone_absent_pages_in_node(nid, j, 3695 zholes_size); 3696 3697 /* 3698 * Adjust realsize so that it accounts for how much memory 3699 * is used by this zone for memmap. This affects the watermark 3700 * and per-cpu initialisations 3701 */ 3702 memmap_pages = 3703 PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT; 3704 if (realsize >= memmap_pages) { 3705 realsize -= memmap_pages; 3706 if (memmap_pages) 3707 printk(KERN_DEBUG 3708 " %s zone: %lu pages used for memmap\n", 3709 zone_names[j], memmap_pages); 3710 } else 3711 printk(KERN_WARNING 3712 " %s zone: %lu pages exceeds realsize %lu\n", 3713 zone_names[j], memmap_pages, realsize); 3714 3715 /* Account for reserved pages */ 3716 if (j == 0 && realsize > dma_reserve) { 3717 realsize -= dma_reserve; 3718 printk(KERN_DEBUG " %s zone: %lu pages reserved\n", 3719 zone_names[0], dma_reserve); 3720 } 3721 3722 if (!is_highmem_idx(j)) 3723 nr_kernel_pages += realsize; 3724 nr_all_pages += realsize; 3725 3726 zone->spanned_pages = size; 3727 zone->present_pages = realsize; 3728#ifdef CONFIG_NUMA 3729 zone->node = nid; 3730 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio) 3731 / 100; 3732 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100; 3733#endif 3734 zone->name = zone_names[j]; 3735 spin_lock_init(&zone->lock); 3736 spin_lock_init(&zone->lru_lock); 3737 zone_seqlock_init(zone); 3738 zone->zone_pgdat = pgdat; 3739 3740 zone->prev_priority = DEF_PRIORITY; 3741 3742 zone_pcp_init(zone); 3743 for_each_lru(l) { 3744 INIT_LIST_HEAD(&zone->lru[l].list); 3745 zone->lru[l].nr_saved_scan = 0; 3746 } 3747 zone->reclaim_stat.recent_rotated[0] = 0; 3748 zone->reclaim_stat.recent_rotated[1] = 0; 3749 zone->reclaim_stat.recent_scanned[0] = 0; 3750 zone->reclaim_stat.recent_scanned[1] = 0; 3751 zap_zone_vm_stats(zone); 3752 zone->flags = 0; 3753 if (!size) 3754 continue; 3755 3756 set_pageblock_order(pageblock_default_order()); 3757 setup_usemap(pgdat, zone, size); 3758 ret = init_currently_empty_zone(zone, zone_start_pfn, 3759 size, MEMMAP_EARLY); 3760 BUG_ON(ret); 3761 memmap_init(size, nid, j, zone_start_pfn); 3762 zone_start_pfn += size; 3763 } 3764} 3765 3766static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat) 3767{ 3768 /* Skip empty nodes */ 3769 if (!pgdat->node_spanned_pages) 3770 return; 3771 3772#ifdef CONFIG_FLAT_NODE_MEM_MAP 3773 /* ia64 gets its own node_mem_map, before this, without bootmem */ 3774 if (!pgdat->node_mem_map) { 3775 unsigned long size, start, end; 3776 struct page *map; 3777 3778 /* 3779 * The zone's endpoints aren't required to be MAX_ORDER 3780 * aligned but the node_mem_map endpoints must be in order 3781 * for the buddy allocator to function correctly. 3782 */ 3783 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); 3784 end = pgdat->node_start_pfn + pgdat->node_spanned_pages; 3785 end = ALIGN(end, MAX_ORDER_NR_PAGES); 3786 size = (end - start) * sizeof(struct page); 3787 map = alloc_remap(pgdat->node_id, size); 3788 if (!map) 3789 map = alloc_bootmem_node(pgdat, size); 3790 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); 3791 } 3792#ifndef CONFIG_NEED_MULTIPLE_NODES 3793 /* 3794 * With no DISCONTIG, the global mem_map is just set as node 0's 3795 */ 3796 if (pgdat == NODE_DATA(0)) { 3797 mem_map = NODE_DATA(0)->node_mem_map; 3798#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3799 if (page_to_pfn(mem_map) != pgdat->node_start_pfn) 3800 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET); 3801#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 3802 } 3803#endif 3804#endif /* CONFIG_FLAT_NODE_MEM_MAP */ 3805} 3806 3807void __paginginit free_area_init_node(int nid, unsigned long *zones_size, 3808 unsigned long node_start_pfn, unsigned long *zholes_size) 3809{ 3810 pg_data_t *pgdat = NODE_DATA(nid); 3811 3812 pgdat->node_id = nid; 3813 pgdat->node_start_pfn = node_start_pfn; 3814 calculate_node_totalpages(pgdat, zones_size, zholes_size); 3815 3816 alloc_node_mem_map(pgdat); 3817#ifdef CONFIG_FLAT_NODE_MEM_MAP 3818 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n", 3819 nid, (unsigned long)pgdat, 3820 (unsigned long)pgdat->node_mem_map); 3821#endif 3822 3823 free_area_init_core(pgdat, zones_size, zholes_size); 3824} 3825 3826#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3827 3828#if MAX_NUMNODES > 1 3829/* 3830 * Figure out the number of possible node ids. 3831 */ 3832static void __init setup_nr_node_ids(void) 3833{ 3834 unsigned int node; 3835 unsigned int highest = 0; 3836 3837 for_each_node_mask(node, node_possible_map) 3838 highest = node; 3839 nr_node_ids = highest + 1; 3840} 3841#else 3842static inline void setup_nr_node_ids(void) 3843{ 3844} 3845#endif 3846 3847/** 3848 * add_active_range - Register a range of PFNs backed by physical memory 3849 * @nid: The node ID the range resides on 3850 * @start_pfn: The start PFN of the available physical memory 3851 * @end_pfn: The end PFN of the available physical memory 3852 * 3853 * These ranges are stored in an early_node_map[] and later used by 3854 * free_area_init_nodes() to calculate zone sizes and holes. If the 3855 * range spans a memory hole, it is up to the architecture to ensure 3856 * the memory is not freed by the bootmem allocator. If possible 3857 * the range being registered will be merged with existing ranges. 3858 */ 3859void __init add_active_range(unsigned int nid, unsigned long start_pfn, 3860 unsigned long end_pfn) 3861{ 3862 int i; 3863 3864 mminit_dprintk(MMINIT_TRACE, "memory_register", 3865 "Entering add_active_range(%d, %#lx, %#lx) " 3866 "%d entries of %d used\n", 3867 nid, start_pfn, end_pfn, 3868 nr_nodemap_entries, MAX_ACTIVE_REGIONS); 3869 3870 mminit_validate_memmodel_limits(&start_pfn, &end_pfn); 3871 3872 /* Merge with existing active regions if possible */ 3873 for (i = 0; i < nr_nodemap_entries; i++) { 3874 if (early_node_map[i].nid != nid) 3875 continue; 3876 3877 /* Skip if an existing region covers this new one */ 3878 if (start_pfn >= early_node_map[i].start_pfn && 3879 end_pfn <= early_node_map[i].end_pfn) 3880 return; 3881 3882 /* Merge forward if suitable */ 3883 if (start_pfn <= early_node_map[i].end_pfn && 3884 end_pfn > early_node_map[i].end_pfn) { 3885 early_node_map[i].end_pfn = end_pfn; 3886 return; 3887 } 3888 3889 /* Merge backward if suitable */ 3890 if (start_pfn < early_node_map[i].end_pfn && 3891 end_pfn >= early_node_map[i].start_pfn) { 3892 early_node_map[i].start_pfn = start_pfn; 3893 return; 3894 } 3895 } 3896 3897 /* Check that early_node_map is large enough */ 3898 if (i >= MAX_ACTIVE_REGIONS) { 3899 printk(KERN_CRIT "More than %d memory regions, truncating\n", 3900 MAX_ACTIVE_REGIONS); 3901 return; 3902 } 3903 3904 early_node_map[i].nid = nid; 3905 early_node_map[i].start_pfn = start_pfn; 3906 early_node_map[i].end_pfn = end_pfn; 3907 nr_nodemap_entries = i + 1; 3908} 3909 3910/** 3911 * remove_active_range - Shrink an existing registered range of PFNs 3912 * @nid: The node id the range is on that should be shrunk 3913 * @start_pfn: The new PFN of the range 3914 * @end_pfn: The new PFN of the range 3915 * 3916 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node. 3917 * The map is kept near the end physical page range that has already been 3918 * registered. This function allows an arch to shrink an existing registered 3919 * range. 3920 */ 3921void __init remove_active_range(unsigned int nid, unsigned long start_pfn, 3922 unsigned long end_pfn) 3923{ 3924 int i, j; 3925 int removed = 0; 3926 3927 printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n", 3928 nid, start_pfn, end_pfn); 3929 3930 /* Find the old active region end and shrink */ 3931 for_each_active_range_index_in_nid(i, nid) { 3932 if (early_node_map[i].start_pfn >= start_pfn && 3933 early_node_map[i].end_pfn <= end_pfn) { 3934 /* clear it */ 3935 early_node_map[i].start_pfn = 0; 3936 early_node_map[i].end_pfn = 0; 3937 removed = 1; 3938 continue; 3939 } 3940 if (early_node_map[i].start_pfn < start_pfn && 3941 early_node_map[i].end_pfn > start_pfn) { 3942 unsigned long temp_end_pfn = early_node_map[i].end_pfn; 3943 early_node_map[i].end_pfn = start_pfn; 3944 if (temp_end_pfn > end_pfn) 3945 add_active_range(nid, end_pfn, temp_end_pfn); 3946 continue; 3947 } 3948 if (early_node_map[i].start_pfn >= start_pfn && 3949 early_node_map[i].end_pfn > end_pfn && 3950 early_node_map[i].start_pfn < end_pfn) { 3951 early_node_map[i].start_pfn = end_pfn; 3952 continue; 3953 } 3954 } 3955 3956 if (!removed) 3957 return; 3958 3959 /* remove the blank ones */ 3960 for (i = nr_nodemap_entries - 1; i > 0; i--) { 3961 if (early_node_map[i].nid != nid) 3962 continue; 3963 if (early_node_map[i].end_pfn) 3964 continue; 3965 /* we found it, get rid of it */ 3966 for (j = i; j < nr_nodemap_entries - 1; j++) 3967 memcpy(&early_node_map[j], &early_node_map[j+1], 3968 sizeof(early_node_map[j])); 3969 j = nr_nodemap_entries - 1; 3970 memset(&early_node_map[j], 0, sizeof(early_node_map[j])); 3971 nr_nodemap_entries--; 3972 } 3973} 3974 3975/** 3976 * remove_all_active_ranges - Remove all currently registered regions 3977 * 3978 * During discovery, it may be found that a table like SRAT is invalid 3979 * and an alternative discovery method must be used. This function removes 3980 * all currently registered regions. 3981 */ 3982void __init remove_all_active_ranges(void) 3983{ 3984 memset(early_node_map, 0, sizeof(early_node_map)); 3985 nr_nodemap_entries = 0; 3986} 3987 3988/* Compare two active node_active_regions */ 3989static int __init cmp_node_active_region(const void *a, const void *b) 3990{ 3991 struct node_active_region *arange = (struct node_active_region *)a; 3992 struct node_active_region *brange = (struct node_active_region *)b; 3993 3994 /* Done this way to avoid overflows */ 3995 if (arange->start_pfn > brange->start_pfn) 3996 return 1; 3997 if (arange->start_pfn < brange->start_pfn) 3998 return -1; 3999 4000 return 0; 4001} 4002 4003/* sort the node_map by start_pfn */ 4004static void __init sort_node_map(void) 4005{ 4006 sort(early_node_map, (size_t)nr_nodemap_entries, 4007 sizeof(struct node_active_region), 4008 cmp_node_active_region, NULL); 4009} 4010 4011/* Find the lowest pfn for a node */ 4012static unsigned long __init find_min_pfn_for_node(int nid) 4013{ 4014 int i; 4015 unsigned long min_pfn = ULONG_MAX; 4016 4017 /* Assuming a sorted map, the first range found has the starting pfn */ 4018 for_each_active_range_index_in_nid(i, nid) 4019 min_pfn = min(min_pfn, early_node_map[i].start_pfn); 4020 4021 if (min_pfn == ULONG_MAX) { 4022 printk(KERN_WARNING 4023 "Could not find start_pfn for node %d\n", nid); 4024 return 0; 4025 } 4026 4027 return min_pfn; 4028} 4029 4030/** 4031 * find_min_pfn_with_active_regions - Find the minimum PFN registered 4032 * 4033 * It returns the minimum PFN based on information provided via 4034 * add_active_range(). 4035 */ 4036unsigned long __init find_min_pfn_with_active_regions(void) 4037{ 4038 return find_min_pfn_for_node(MAX_NUMNODES); 4039} 4040 4041/* 4042 * early_calculate_totalpages() 4043 * Sum pages in active regions for movable zone. 4044 * Populate N_HIGH_MEMORY for calculating usable_nodes. 4045 */ 4046static unsigned long __init early_calculate_totalpages(void) 4047{ 4048 int i; 4049 unsigned long totalpages = 0; 4050 4051 for (i = 0; i < nr_nodemap_entries; i++) { 4052 unsigned long pages = early_node_map[i].end_pfn - 4053 early_node_map[i].start_pfn; 4054 totalpages += pages; 4055 if (pages) 4056 node_set_state(early_node_map[i].nid, N_HIGH_MEMORY); 4057 } 4058 return totalpages; 4059} 4060 4061/* 4062 * Find the PFN the Movable zone begins in each node. Kernel memory 4063 * is spread evenly between nodes as long as the nodes have enough 4064 * memory. When they don't, some nodes will have more kernelcore than 4065 * others 4066 */ 4067static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn) 4068{ 4069 int i, nid; 4070 unsigned long usable_startpfn; 4071 unsigned long kernelcore_node, kernelcore_remaining; 4072 /* save the state before borrow the nodemask */ 4073 nodemask_t saved_node_state = node_states[N_HIGH_MEMORY]; 4074 unsigned long totalpages = early_calculate_totalpages(); 4075 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]); 4076 4077 /* 4078 * If movablecore was specified, calculate what size of 4079 * kernelcore that corresponds so that memory usable for 4080 * any allocation type is evenly spread. If both kernelcore 4081 * and movablecore are specified, then the value of kernelcore 4082 * will be used for required_kernelcore if it's greater than 4083 * what movablecore would have allowed. 4084 */ 4085 if (required_movablecore) { 4086 unsigned long corepages; 4087 4088 /* 4089 * Round-up so that ZONE_MOVABLE is at least as large as what 4090 * was requested by the user 4091 */ 4092 required_movablecore = 4093 roundup(required_movablecore, MAX_ORDER_NR_PAGES); 4094 corepages = totalpages - required_movablecore; 4095 4096 required_kernelcore = max(required_kernelcore, corepages); 4097 } 4098 4099 /* If kernelcore was not specified, there is no ZONE_MOVABLE */ 4100 if (!required_kernelcore) 4101 goto out; 4102 4103 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ 4104 find_usable_zone_for_movable(); 4105 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; 4106 4107restart: 4108 /* Spread kernelcore memory as evenly as possible throughout nodes */ 4109 kernelcore_node = required_kernelcore / usable_nodes; 4110 for_each_node_state(nid, N_HIGH_MEMORY) { 4111 /* 4112 * Recalculate kernelcore_node if the division per node 4113 * now exceeds what is necessary to satisfy the requested 4114 * amount of memory for the kernel 4115 */ 4116 if (required_kernelcore < kernelcore_node) 4117 kernelcore_node = required_kernelcore / usable_nodes; 4118 4119 /* 4120 * As the map is walked, we track how much memory is usable 4121 * by the kernel using kernelcore_remaining. When it is 4122 * 0, the rest of the node is usable by ZONE_MOVABLE 4123 */ 4124 kernelcore_remaining = kernelcore_node; 4125 4126 /* Go through each range of PFNs within this node */ 4127 for_each_active_range_index_in_nid(i, nid) { 4128 unsigned long start_pfn, end_pfn; 4129 unsigned long size_pages; 4130 4131 start_pfn = max(early_node_map[i].start_pfn, 4132 zone_movable_pfn[nid]); 4133 end_pfn = early_node_map[i].end_pfn; 4134 if (start_pfn >= end_pfn) 4135 continue; 4136 4137 /* Account for what is only usable for kernelcore */ 4138 if (start_pfn < usable_startpfn) { 4139 unsigned long kernel_pages; 4140 kernel_pages = min(end_pfn, usable_startpfn) 4141 - start_pfn; 4142 4143 kernelcore_remaining -= min(kernel_pages, 4144 kernelcore_remaining); 4145 required_kernelcore -= min(kernel_pages, 4146 required_kernelcore); 4147 4148 /* Continue if range is now fully accounted */ 4149 if (end_pfn <= usable_startpfn) { 4150 4151 /* 4152 * Push zone_movable_pfn to the end so 4153 * that if we have to rebalance 4154 * kernelcore across nodes, we will 4155 * not double account here 4156 */ 4157 zone_movable_pfn[nid] = end_pfn; 4158 continue; 4159 } 4160 start_pfn = usable_startpfn; 4161 } 4162 4163 /* 4164 * The usable PFN range for ZONE_MOVABLE is from 4165 * start_pfn->end_pfn. Calculate size_pages as the 4166 * number of pages used as kernelcore 4167 */ 4168 size_pages = end_pfn - start_pfn; 4169 if (size_pages > kernelcore_remaining) 4170 size_pages = kernelcore_remaining; 4171 zone_movable_pfn[nid] = start_pfn + size_pages; 4172 4173 /* 4174 * Some kernelcore has been met, update counts and 4175 * break if the kernelcore for this node has been 4176 * satisified 4177 */ 4178 required_kernelcore -= min(required_kernelcore, 4179 size_pages); 4180 kernelcore_remaining -= size_pages; 4181 if (!kernelcore_remaining) 4182 break; 4183 } 4184 } 4185 4186 /* 4187 * If there is still required_kernelcore, we do another pass with one 4188 * less node in the count. This will push zone_movable_pfn[nid] further 4189 * along on the nodes that still have memory until kernelcore is 4190 * satisified 4191 */ 4192 usable_nodes--; 4193 if (usable_nodes && required_kernelcore > usable_nodes) 4194 goto restart; 4195 4196 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ 4197 for (nid = 0; nid < MAX_NUMNODES; nid++) 4198 zone_movable_pfn[nid] = 4199 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); 4200 4201out: 4202 /* restore the node_state */ 4203 node_states[N_HIGH_MEMORY] = saved_node_state; 4204} 4205 4206/* Any regular memory on that node ? */ 4207static void check_for_regular_memory(pg_data_t *pgdat) 4208{ 4209#ifdef CONFIG_HIGHMEM 4210 enum zone_type zone_type; 4211 4212 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) { 4213 struct zone *zone = &pgdat->node_zones[zone_type]; 4214 if (zone->present_pages) 4215 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY); 4216 } 4217#endif 4218} 4219 4220/** 4221 * free_area_init_nodes - Initialise all pg_data_t and zone data 4222 * @max_zone_pfn: an array of max PFNs for each zone 4223 * 4224 * This will call free_area_init_node() for each active node in the system. 4225 * Using the page ranges provided by add_active_range(), the size of each 4226 * zone in each node and their holes is calculated. If the maximum PFN 4227 * between two adjacent zones match, it is assumed that the zone is empty. 4228 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed 4229 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone 4230 * starts where the previous one ended. For example, ZONE_DMA32 starts 4231 * at arch_max_dma_pfn. 4232 */ 4233void __init free_area_init_nodes(unsigned long *max_zone_pfn) 4234{ 4235 unsigned long nid; 4236 int i; 4237 4238 /* Sort early_node_map as initialisation assumes it is sorted */ 4239 sort_node_map(); 4240 4241 /* Record where the zone boundaries are */ 4242 memset(arch_zone_lowest_possible_pfn, 0, 4243 sizeof(arch_zone_lowest_possible_pfn)); 4244 memset(arch_zone_highest_possible_pfn, 0, 4245 sizeof(arch_zone_highest_possible_pfn)); 4246 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); 4247 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; 4248 for (i = 1; i < MAX_NR_ZONES; i++) { 4249 if (i == ZONE_MOVABLE) 4250 continue; 4251 arch_zone_lowest_possible_pfn[i] = 4252 arch_zone_highest_possible_pfn[i-1]; 4253 arch_zone_highest_possible_pfn[i] = 4254 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); 4255 } 4256 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0; 4257 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0; 4258 4259 /* Find the PFNs that ZONE_MOVABLE begins at in each node */ 4260 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); 4261 find_zone_movable_pfns_for_nodes(zone_movable_pfn); 4262 4263 /* Print out the zone ranges */ 4264 printk("Zone PFN ranges:\n"); 4265 for (i = 0; i < MAX_NR_ZONES; i++) { 4266 if (i == ZONE_MOVABLE) 4267 continue; 4268 printk(" %-8s %0#10lx -> %0#10lx\n", 4269 zone_names[i], 4270 arch_zone_lowest_possible_pfn[i], 4271 arch_zone_highest_possible_pfn[i]); 4272 } 4273 4274 /* Print out the PFNs ZONE_MOVABLE begins at in each node */ 4275 printk("Movable zone start PFN for each node\n"); 4276 for (i = 0; i < MAX_NUMNODES; i++) { 4277 if (zone_movable_pfn[i]) 4278 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]); 4279 } 4280 4281 /* Print out the early_node_map[] */ 4282 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries); 4283 for (i = 0; i < nr_nodemap_entries; i++) 4284 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid, 4285 early_node_map[i].start_pfn, 4286 early_node_map[i].end_pfn); 4287 4288 /* Initialise every node */ 4289 mminit_verify_pageflags_layout(); 4290 setup_nr_node_ids(); 4291 for_each_online_node(nid) { 4292 pg_data_t *pgdat = NODE_DATA(nid); 4293 free_area_init_node(nid, NULL, 4294 find_min_pfn_for_node(nid), NULL); 4295 4296 /* Any memory on that node */ 4297 if (pgdat->node_present_pages) 4298 node_set_state(nid, N_HIGH_MEMORY); 4299 check_for_regular_memory(pgdat); 4300 } 4301} 4302 4303static int __init cmdline_parse_core(char *p, unsigned long *core) 4304{ 4305 unsigned long long coremem; 4306 if (!p) 4307 return -EINVAL; 4308 4309 coremem = memparse(p, &p); 4310 *core = coremem >> PAGE_SHIFT; 4311 4312 /* Paranoid check that UL is enough for the coremem value */ 4313 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); 4314 4315 return 0; 4316} 4317 4318/* 4319 * kernelcore=size sets the amount of memory for use for allocations that 4320 * cannot be reclaimed or migrated. 4321 */ 4322static int __init cmdline_parse_kernelcore(char *p) 4323{ 4324 return cmdline_parse_core(p, &required_kernelcore); 4325} 4326 4327/* 4328 * movablecore=size sets the amount of memory for use for allocations that 4329 * can be reclaimed or migrated. 4330 */ 4331static int __init cmdline_parse_movablecore(char *p) 4332{ 4333 return cmdline_parse_core(p, &required_movablecore); 4334} 4335 4336early_param("kernelcore", cmdline_parse_kernelcore); 4337early_param("movablecore", cmdline_parse_movablecore); 4338 4339#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 4340 4341/** 4342 * set_dma_reserve - set the specified number of pages reserved in the first zone 4343 * @new_dma_reserve: The number of pages to mark reserved 4344 * 4345 * The per-cpu batchsize and zone watermarks are determined by present_pages. 4346 * In the DMA zone, a significant percentage may be consumed by kernel image 4347 * and other unfreeable allocations which can skew the watermarks badly. This 4348 * function may optionally be used to account for unfreeable pages in the 4349 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and 4350 * smaller per-cpu batchsize. 4351 */ 4352void __init set_dma_reserve(unsigned long new_dma_reserve) 4353{ 4354 dma_reserve = new_dma_reserve; 4355} 4356 4357#ifndef CONFIG_NEED_MULTIPLE_NODES 4358struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] }; 4359EXPORT_SYMBOL(contig_page_data); 4360#endif 4361 4362void __init free_area_init(unsigned long *zones_size) 4363{ 4364 free_area_init_node(0, zones_size, 4365 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 4366} 4367 4368static int page_alloc_cpu_notify(struct notifier_block *self, 4369 unsigned long action, void *hcpu) 4370{ 4371 int cpu = (unsigned long)hcpu; 4372 4373 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { 4374 drain_pages(cpu); 4375 4376 /* 4377 * Spill the event counters of the dead processor 4378 * into the current processors event counters. 4379 * This artificially elevates the count of the current 4380 * processor. 4381 */ 4382 vm_events_fold_cpu(cpu); 4383 4384 /* 4385 * Zero the differential counters of the dead processor 4386 * so that the vm statistics are consistent. 4387 * 4388 * This is only okay since the processor is dead and cannot 4389 * race with what we are doing. 4390 */ 4391 refresh_cpu_vm_stats(cpu); 4392 } 4393 return NOTIFY_OK; 4394} 4395 4396void __init page_alloc_init(void) 4397{ 4398 hotcpu_notifier(page_alloc_cpu_notify, 0); 4399} 4400 4401/* 4402 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio 4403 * or min_free_kbytes changes. 4404 */ 4405static void calculate_totalreserve_pages(void) 4406{ 4407 struct pglist_data *pgdat; 4408 unsigned long reserve_pages = 0; 4409 enum zone_type i, j; 4410 4411 for_each_online_pgdat(pgdat) { 4412 for (i = 0; i < MAX_NR_ZONES; i++) { 4413 struct zone *zone = pgdat->node_zones + i; 4414 unsigned long max = 0; 4415 4416 /* Find valid and maximum lowmem_reserve in the zone */ 4417 for (j = i; j < MAX_NR_ZONES; j++) { 4418 if (zone->lowmem_reserve[j] > max) 4419 max = zone->lowmem_reserve[j]; 4420 } 4421 4422 /* we treat the high watermark as reserved pages. */ 4423 max += high_wmark_pages(zone); 4424 4425 if (max > zone->present_pages) 4426 max = zone->present_pages; 4427 reserve_pages += max; 4428 } 4429 } 4430 totalreserve_pages = reserve_pages; 4431} 4432 4433/* 4434 * setup_per_zone_lowmem_reserve - called whenever 4435 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 4436 * has a correct pages reserved value, so an adequate number of 4437 * pages are left in the zone after a successful __alloc_pages(). 4438 */ 4439static void setup_per_zone_lowmem_reserve(void) 4440{ 4441 struct pglist_data *pgdat; 4442 enum zone_type j, idx; 4443 4444 for_each_online_pgdat(pgdat) { 4445 for (j = 0; j < MAX_NR_ZONES; j++) { 4446 struct zone *zone = pgdat->node_zones + j; 4447 unsigned long present_pages = zone->present_pages; 4448 4449 zone->lowmem_reserve[j] = 0; 4450 4451 idx = j; 4452 while (idx) { 4453 struct zone *lower_zone; 4454 4455 idx--; 4456 4457 if (sysctl_lowmem_reserve_ratio[idx] < 1) 4458 sysctl_lowmem_reserve_ratio[idx] = 1; 4459 4460 lower_zone = pgdat->node_zones + idx; 4461 lower_zone->lowmem_reserve[j] = present_pages / 4462 sysctl_lowmem_reserve_ratio[idx]; 4463 present_pages += lower_zone->present_pages; 4464 } 4465 } 4466 } 4467 4468 /* update totalreserve_pages */ 4469 calculate_totalreserve_pages(); 4470} 4471 4472/** 4473 * setup_per_zone_wmarks - called when min_free_kbytes changes 4474 * or when memory is hot-{added|removed} 4475 * 4476 * Ensures that the watermark[min,low,high] values for each zone are set 4477 * correctly with respect to min_free_kbytes. 4478 */ 4479void setup_per_zone_wmarks(void) 4480{ 4481 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 4482 unsigned long lowmem_pages = 0; 4483 struct zone *zone; 4484 unsigned long flags; 4485 4486 /* Calculate total number of !ZONE_HIGHMEM pages */ 4487 for_each_zone(zone) { 4488 if (!is_highmem(zone)) 4489 lowmem_pages += zone->present_pages; 4490 } 4491 4492 for_each_zone(zone) { 4493 u64 tmp; 4494 4495 spin_lock_irqsave(&zone->lock, flags); 4496 tmp = (u64)pages_min * zone->present_pages; 4497 do_div(tmp, lowmem_pages); 4498 if (is_highmem(zone)) { 4499 /* 4500 * __GFP_HIGH and PF_MEMALLOC allocations usually don't 4501 * need highmem pages, so cap pages_min to a small 4502 * value here. 4503 * 4504 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN) 4505 * deltas controls asynch page reclaim, and so should 4506 * not be capped for highmem. 4507 */ 4508 int min_pages; 4509 4510 min_pages = zone->present_pages / 1024; 4511 if (min_pages < SWAP_CLUSTER_MAX) 4512 min_pages = SWAP_CLUSTER_MAX; 4513 if (min_pages > 128) 4514 min_pages = 128; 4515 zone->watermark[WMARK_MIN] = min_pages; 4516 } else { 4517 /* 4518 * If it's a lowmem zone, reserve a number of pages 4519 * proportionate to the zone's size. 4520 */ 4521 zone->watermark[WMARK_MIN] = tmp; 4522 } 4523 4524 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2); 4525 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1); 4526 setup_zone_migrate_reserve(zone); 4527 spin_unlock_irqrestore(&zone->lock, flags); 4528 } 4529 4530 /* update totalreserve_pages */ 4531 calculate_totalreserve_pages(); 4532} 4533 4534/** 4535 * The inactive anon list should be small enough that the VM never has to 4536 * do too much work, but large enough that each inactive page has a chance 4537 * to be referenced again before it is swapped out. 4538 * 4539 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to 4540 * INACTIVE_ANON pages on this zone's LRU, maintained by the 4541 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of 4542 * the anonymous pages are kept on the inactive list. 4543 * 4544 * total target max 4545 * memory ratio inactive anon 4546 * ------------------------------------- 4547 * 10MB 1 5MB 4548 * 100MB 1 50MB 4549 * 1GB 3 250MB 4550 * 10GB 10 0.9GB 4551 * 100GB 31 3GB 4552 * 1TB 101 10GB 4553 * 10TB 320 32GB 4554 */ 4555void calculate_zone_inactive_ratio(struct zone *zone) 4556{ 4557 unsigned int gb, ratio; 4558 4559 /* Zone size in gigabytes */ 4560 gb = zone->present_pages >> (30 - PAGE_SHIFT); 4561 if (gb) 4562 ratio = int_sqrt(10 * gb); 4563 else 4564 ratio = 1; 4565 4566 zone->inactive_ratio = ratio; 4567} 4568 4569static void __init setup_per_zone_inactive_ratio(void) 4570{ 4571 struct zone *zone; 4572 4573 for_each_zone(zone) 4574 calculate_zone_inactive_ratio(zone); 4575} 4576 4577/* 4578 * Initialise min_free_kbytes. 4579 * 4580 * For small machines we want it small (128k min). For large machines 4581 * we want it large (64MB max). But it is not linear, because network 4582 * bandwidth does not increase linearly with machine size. We use 4583 * 4584 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 4585 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 4586 * 4587 * which yields 4588 * 4589 * 16MB: 512k 4590 * 32MB: 724k 4591 * 64MB: 1024k 4592 * 128MB: 1448k 4593 * 256MB: 2048k 4594 * 512MB: 2896k 4595 * 1024MB: 4096k 4596 * 2048MB: 5792k 4597 * 4096MB: 8192k 4598 * 8192MB: 11584k 4599 * 16384MB: 16384k 4600 */ 4601static int __init init_per_zone_wmark_min(void) 4602{ 4603 unsigned long lowmem_kbytes; 4604 4605 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 4606 4607 min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 4608 if (min_free_kbytes < 128) 4609 min_free_kbytes = 128; 4610 if (min_free_kbytes > 65536) 4611 min_free_kbytes = 65536; 4612 setup_per_zone_wmarks(); 4613 setup_per_zone_lowmem_reserve(); 4614 setup_per_zone_inactive_ratio(); 4615 return 0; 4616} 4617module_init(init_per_zone_wmark_min) 4618 4619/* 4620 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 4621 * that we can call two helper functions whenever min_free_kbytes 4622 * changes. 4623 */ 4624int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 4625 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4626{ 4627 proc_dointvec(table, write, file, buffer, length, ppos); 4628 if (write) 4629 setup_per_zone_wmarks(); 4630 return 0; 4631} 4632 4633#ifdef CONFIG_NUMA 4634int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, 4635 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4636{ 4637 struct zone *zone; 4638 int rc; 4639 4640 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4641 if (rc) 4642 return rc; 4643 4644 for_each_zone(zone) 4645 zone->min_unmapped_pages = (zone->present_pages * 4646 sysctl_min_unmapped_ratio) / 100; 4647 return 0; 4648} 4649 4650int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write, 4651 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4652{ 4653 struct zone *zone; 4654 int rc; 4655 4656 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4657 if (rc) 4658 return rc; 4659 4660 for_each_zone(zone) 4661 zone->min_slab_pages = (zone->present_pages * 4662 sysctl_min_slab_ratio) / 100; 4663 return 0; 4664} 4665#endif 4666 4667/* 4668 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 4669 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 4670 * whenever sysctl_lowmem_reserve_ratio changes. 4671 * 4672 * The reserve ratio obviously has absolutely no relation with the 4673 * minimum watermarks. The lowmem reserve ratio can only make sense 4674 * if in function of the boot time zone sizes. 4675 */ 4676int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, 4677 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4678{ 4679 proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4680 setup_per_zone_lowmem_reserve(); 4681 return 0; 4682} 4683 4684/* 4685 * percpu_pagelist_fraction - changes the pcp->high for each zone on each 4686 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist 4687 * can have before it gets flushed back to buddy allocator. 4688 */ 4689 4690int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, 4691 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4692{ 4693 struct zone *zone; 4694 unsigned int cpu; 4695 int ret; 4696 4697 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4698 if (!write || (ret == -EINVAL)) 4699 return ret; 4700 for_each_populated_zone(zone) { 4701 for_each_online_cpu(cpu) { 4702 unsigned long high; 4703 high = zone->present_pages / percpu_pagelist_fraction; 4704 setup_pagelist_highmark(zone_pcp(zone, cpu), high); 4705 } 4706 } 4707 return 0; 4708} 4709 4710int hashdist = HASHDIST_DEFAULT; 4711 4712#ifdef CONFIG_NUMA 4713static int __init set_hashdist(char *str) 4714{ 4715 if (!str) 4716 return 0; 4717 hashdist = simple_strtoul(str, &str, 0); 4718 return 1; 4719} 4720__setup("hashdist=", set_hashdist); 4721#endif 4722 4723/* 4724 * allocate a large system hash table from bootmem 4725 * - it is assumed that the hash table must contain an exact power-of-2 4726 * quantity of entries 4727 * - limit is the number of hash buckets, not the total allocation size 4728 */ 4729void *__init alloc_large_system_hash(const char *tablename, 4730 unsigned long bucketsize, 4731 unsigned long numentries, 4732 int scale, 4733 int flags, 4734 unsigned int *_hash_shift, 4735 unsigned int *_hash_mask, 4736 unsigned long limit) 4737{ 4738 unsigned long long max = limit; 4739 unsigned long log2qty, size; 4740 void *table = NULL; 4741 4742 /* allow the kernel cmdline to have a say */ 4743 if (!numentries) { 4744 /* round applicable memory size up to nearest megabyte */ 4745 numentries = nr_kernel_pages; 4746 numentries += (1UL << (20 - PAGE_SHIFT)) - 1; 4747 numentries >>= 20 - PAGE_SHIFT; 4748 numentries <<= 20 - PAGE_SHIFT; 4749 4750 /* limit to 1 bucket per 2^scale bytes of low memory */ 4751 if (scale > PAGE_SHIFT) 4752 numentries >>= (scale - PAGE_SHIFT); 4753 else 4754 numentries <<= (PAGE_SHIFT - scale); 4755 4756 /* Make sure we've got at least a 0-order allocation.. */ 4757 if (unlikely((numentries * bucketsize) < PAGE_SIZE)) 4758 numentries = PAGE_SIZE / bucketsize; 4759 } 4760 numentries = roundup_pow_of_two(numentries); 4761 4762 /* limit allocation size to 1/16 total memory by default */ 4763 if (max == 0) { 4764 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 4765 do_div(max, bucketsize); 4766 } 4767 4768 if (numentries > max) 4769 numentries = max; 4770 4771 log2qty = ilog2(numentries); 4772 4773 do { 4774 size = bucketsize << log2qty; 4775 if (flags & HASH_EARLY) 4776 table = alloc_bootmem_nopanic(size); 4777 else if (hashdist) 4778 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 4779 else { 4780 /* 4781 * If bucketsize is not a power-of-two, we may free 4782 * some pages at the end of hash table which 4783 * alloc_pages_exact() automatically does 4784 */ 4785 if (get_order(size) < MAX_ORDER) { 4786 table = alloc_pages_exact(size, GFP_ATOMIC); 4787 kmemleak_alloc(table, size, 1, GFP_ATOMIC); 4788 } 4789 } 4790 } while (!table && size > PAGE_SIZE && --log2qty); 4791 4792 if (!table) 4793 panic("Failed to allocate %s hash table\n", tablename); 4794 4795 printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n", 4796 tablename, 4797 (1U << log2qty), 4798 ilog2(size) - PAGE_SHIFT, 4799 size); 4800 4801 if (_hash_shift) 4802 *_hash_shift = log2qty; 4803 if (_hash_mask) 4804 *_hash_mask = (1 << log2qty) - 1; 4805 4806 return table; 4807} 4808 4809/* Return a pointer to the bitmap storing bits affecting a block of pages */ 4810static inline unsigned long *get_pageblock_bitmap(struct zone *zone, 4811 unsigned long pfn) 4812{ 4813#ifdef CONFIG_SPARSEMEM 4814 return __pfn_to_section(pfn)->pageblock_flags; 4815#else 4816 return zone->pageblock_flags; 4817#endif /* CONFIG_SPARSEMEM */ 4818} 4819 4820static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) 4821{ 4822#ifdef CONFIG_SPARSEMEM 4823 pfn &= (PAGES_PER_SECTION-1); 4824 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 4825#else 4826 pfn = pfn - zone->zone_start_pfn; 4827 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 4828#endif /* CONFIG_SPARSEMEM */ 4829} 4830 4831/** 4832 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages 4833 * @page: The page within the block of interest 4834 * @start_bitidx: The first bit of interest to retrieve 4835 * @end_bitidx: The last bit of interest 4836 * returns pageblock_bits flags 4837 */ 4838unsigned long get_pageblock_flags_group(struct page *page, 4839 int start_bitidx, int end_bitidx) 4840{ 4841 struct zone *zone; 4842 unsigned long *bitmap; 4843 unsigned long pfn, bitidx; 4844 unsigned long flags = 0; 4845 unsigned long value = 1; 4846 4847 zone = page_zone(page); 4848 pfn = page_to_pfn(page); 4849 bitmap = get_pageblock_bitmap(zone, pfn); 4850 bitidx = pfn_to_bitidx(zone, pfn); 4851 4852 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 4853 if (test_bit(bitidx + start_bitidx, bitmap)) 4854 flags |= value; 4855 4856 return flags; 4857} 4858 4859/** 4860 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages 4861 * @page: The page within the block of interest 4862 * @start_bitidx: The first bit of interest 4863 * @end_bitidx: The last bit of interest 4864 * @flags: The flags to set 4865 */ 4866void set_pageblock_flags_group(struct page *page, unsigned long flags, 4867 int start_bitidx, int end_bitidx) 4868{ 4869 struct zone *zone; 4870 unsigned long *bitmap; 4871 unsigned long pfn, bitidx; 4872 unsigned long value = 1; 4873 4874 zone = page_zone(page); 4875 pfn = page_to_pfn(page); 4876 bitmap = get_pageblock_bitmap(zone, pfn); 4877 bitidx = pfn_to_bitidx(zone, pfn); 4878 VM_BUG_ON(pfn < zone->zone_start_pfn); 4879 VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages); 4880 4881 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 4882 if (flags & value) 4883 __set_bit(bitidx + start_bitidx, bitmap); 4884 else 4885 __clear_bit(bitidx + start_bitidx, bitmap); 4886} 4887 4888/* 4889 * This is designed as sub function...plz see page_isolation.c also. 4890 * set/clear page block's type to be ISOLATE. 4891 * page allocater never alloc memory from ISOLATE block. 4892 */ 4893 4894int set_migratetype_isolate(struct page *page) 4895{ 4896 struct zone *zone; 4897 unsigned long flags; 4898 int ret = -EBUSY; 4899 4900 zone = page_zone(page); 4901 spin_lock_irqsave(&zone->lock, flags); 4902 /* 4903 * In future, more migrate types will be able to be isolation target. 4904 */ 4905 if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE) 4906 goto out; 4907 set_pageblock_migratetype(page, MIGRATE_ISOLATE); 4908 move_freepages_block(zone, page, MIGRATE_ISOLATE); 4909 ret = 0; 4910out: 4911 spin_unlock_irqrestore(&zone->lock, flags); 4912 if (!ret) 4913 drain_all_pages(); 4914 return ret; 4915} 4916 4917void unset_migratetype_isolate(struct page *page) 4918{ 4919 struct zone *zone; 4920 unsigned long flags; 4921 zone = page_zone(page); 4922 spin_lock_irqsave(&zone->lock, flags); 4923 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE) 4924 goto out; 4925 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 4926 move_freepages_block(zone, page, MIGRATE_MOVABLE); 4927out: 4928 spin_unlock_irqrestore(&zone->lock, flags); 4929} 4930 4931#ifdef CONFIG_MEMORY_HOTREMOVE 4932/* 4933 * All pages in the range must be isolated before calling this. 4934 */ 4935void 4936__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) 4937{ 4938 struct page *page; 4939 struct zone *zone; 4940 int order, i; 4941 unsigned long pfn; 4942 unsigned long flags; 4943 /* find the first valid pfn */ 4944 for (pfn = start_pfn; pfn < end_pfn; pfn++) 4945 if (pfn_valid(pfn)) 4946 break; 4947 if (pfn == end_pfn) 4948 return; 4949 zone = page_zone(pfn_to_page(pfn)); 4950 spin_lock_irqsave(&zone->lock, flags); 4951 pfn = start_pfn; 4952 while (pfn < end_pfn) { 4953 if (!pfn_valid(pfn)) { 4954 pfn++; 4955 continue; 4956 } 4957 page = pfn_to_page(pfn); 4958 BUG_ON(page_count(page)); 4959 BUG_ON(!PageBuddy(page)); 4960 order = page_order(page); 4961#ifdef CONFIG_DEBUG_VM 4962 printk(KERN_INFO "remove from free list %lx %d %lx\n", 4963 pfn, 1 << order, end_pfn); 4964#endif 4965 list_del(&page->lru); 4966 rmv_page_order(page); 4967 zone->free_area[order].nr_free--; 4968 __mod_zone_page_state(zone, NR_FREE_PAGES, 4969 - (1UL << order)); 4970 for (i = 0; i < (1 << order); i++) 4971 SetPageReserved((page+i)); 4972 pfn += (1 << order); 4973 } 4974 spin_unlock_irqrestore(&zone->lock, flags); 4975} 4976#endif 4977