page_alloc.c revision 5c87eada68fe5d29a5f67528f81b6e45124f579b
1/* 2 * linux/mm/page_alloc.c 3 * 4 * Manages the free list, the system allocates free pages here. 5 * Note that kmalloc() lives in slab.c 6 * 7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 8 * Swap reorganised 29.12.95, Stephen Tweedie 9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999 11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999 12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000 13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002 14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton) 15 */ 16 17#include <linux/stddef.h> 18#include <linux/mm.h> 19#include <linux/swap.h> 20#include <linux/interrupt.h> 21#include <linux/pagemap.h> 22#include <linux/jiffies.h> 23#include <linux/bootmem.h> 24#include <linux/compiler.h> 25#include <linux/kernel.h> 26#include <linux/module.h> 27#include <linux/suspend.h> 28#include <linux/pagevec.h> 29#include <linux/blkdev.h> 30#include <linux/slab.h> 31#include <linux/oom.h> 32#include <linux/notifier.h> 33#include <linux/topology.h> 34#include <linux/sysctl.h> 35#include <linux/cpu.h> 36#include <linux/cpuset.h> 37#include <linux/memory_hotplug.h> 38#include <linux/nodemask.h> 39#include <linux/vmalloc.h> 40#include <linux/mempolicy.h> 41#include <linux/stop_machine.h> 42#include <linux/sort.h> 43#include <linux/pfn.h> 44#include <linux/backing-dev.h> 45#include <linux/fault-inject.h> 46#include <linux/page-isolation.h> 47#include <linux/page_cgroup.h> 48#include <linux/debugobjects.h> 49#include <linux/kmemleak.h> 50 51#include <asm/tlbflush.h> 52#include <asm/div64.h> 53#include "internal.h" 54 55/* 56 * Array of node states. 57 */ 58nodemask_t node_states[NR_NODE_STATES] __read_mostly = { 59 [N_POSSIBLE] = NODE_MASK_ALL, 60 [N_ONLINE] = { { [0] = 1UL } }, 61#ifndef CONFIG_NUMA 62 [N_NORMAL_MEMORY] = { { [0] = 1UL } }, 63#ifdef CONFIG_HIGHMEM 64 [N_HIGH_MEMORY] = { { [0] = 1UL } }, 65#endif 66 [N_CPU] = { { [0] = 1UL } }, 67#endif /* NUMA */ 68}; 69EXPORT_SYMBOL(node_states); 70 71unsigned long totalram_pages __read_mostly; 72unsigned long totalreserve_pages __read_mostly; 73unsigned long highest_memmap_pfn __read_mostly; 74int percpu_pagelist_fraction; 75 76#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 77int pageblock_order __read_mostly; 78#endif 79 80static void __free_pages_ok(struct page *page, unsigned int order); 81 82/* 83 * results with 256, 32 in the lowmem_reserve sysctl: 84 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) 85 * 1G machine -> (16M dma, 784M normal, 224M high) 86 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA 87 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL 88 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA 89 * 90 * TBD: should special case ZONE_DMA32 machines here - in those we normally 91 * don't need any ZONE_NORMAL reservation 92 */ 93int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 94#ifdef CONFIG_ZONE_DMA 95 256, 96#endif 97#ifdef CONFIG_ZONE_DMA32 98 256, 99#endif 100#ifdef CONFIG_HIGHMEM 101 32, 102#endif 103 32, 104}; 105 106EXPORT_SYMBOL(totalram_pages); 107 108static char * const zone_names[MAX_NR_ZONES] = { 109#ifdef CONFIG_ZONE_DMA 110 "DMA", 111#endif 112#ifdef CONFIG_ZONE_DMA32 113 "DMA32", 114#endif 115 "Normal", 116#ifdef CONFIG_HIGHMEM 117 "HighMem", 118#endif 119 "Movable", 120}; 121 122int min_free_kbytes = 1024; 123 124unsigned long __meminitdata nr_kernel_pages; 125unsigned long __meminitdata nr_all_pages; 126static unsigned long __meminitdata dma_reserve; 127 128#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 129 /* 130 * MAX_ACTIVE_REGIONS determines the maximum number of distinct 131 * ranges of memory (RAM) that may be registered with add_active_range(). 132 * Ranges passed to add_active_range() will be merged if possible 133 * so the number of times add_active_range() can be called is 134 * related to the number of nodes and the number of holes 135 */ 136 #ifdef CONFIG_MAX_ACTIVE_REGIONS 137 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */ 138 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS 139 #else 140 #if MAX_NUMNODES >= 32 141 /* If there can be many nodes, allow up to 50 holes per node */ 142 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50) 143 #else 144 /* By default, allow up to 256 distinct regions */ 145 #define MAX_ACTIVE_REGIONS 256 146 #endif 147 #endif 148 149 static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS]; 150 static int __meminitdata nr_nodemap_entries; 151 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; 152 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; 153 static unsigned long __initdata required_kernelcore; 154 static unsigned long __initdata required_movablecore; 155 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES]; 156 157 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ 158 int movable_zone; 159 EXPORT_SYMBOL(movable_zone); 160#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 161 162#if MAX_NUMNODES > 1 163int nr_node_ids __read_mostly = MAX_NUMNODES; 164int nr_online_nodes __read_mostly = 1; 165EXPORT_SYMBOL(nr_node_ids); 166EXPORT_SYMBOL(nr_online_nodes); 167#endif 168 169int page_group_by_mobility_disabled __read_mostly; 170 171static void set_pageblock_migratetype(struct page *page, int migratetype) 172{ 173 174 if (unlikely(page_group_by_mobility_disabled)) 175 migratetype = MIGRATE_UNMOVABLE; 176 177 set_pageblock_flags_group(page, (unsigned long)migratetype, 178 PB_migrate, PB_migrate_end); 179} 180 181#ifdef CONFIG_DEBUG_VM 182static int page_outside_zone_boundaries(struct zone *zone, struct page *page) 183{ 184 int ret = 0; 185 unsigned seq; 186 unsigned long pfn = page_to_pfn(page); 187 188 do { 189 seq = zone_span_seqbegin(zone); 190 if (pfn >= zone->zone_start_pfn + zone->spanned_pages) 191 ret = 1; 192 else if (pfn < zone->zone_start_pfn) 193 ret = 1; 194 } while (zone_span_seqretry(zone, seq)); 195 196 return ret; 197} 198 199static int page_is_consistent(struct zone *zone, struct page *page) 200{ 201 if (!pfn_valid_within(page_to_pfn(page))) 202 return 0; 203 if (zone != page_zone(page)) 204 return 0; 205 206 return 1; 207} 208/* 209 * Temporary debugging check for pages not lying within a given zone. 210 */ 211static int bad_range(struct zone *zone, struct page *page) 212{ 213 if (page_outside_zone_boundaries(zone, page)) 214 return 1; 215 if (!page_is_consistent(zone, page)) 216 return 1; 217 218 return 0; 219} 220#else 221static inline int bad_range(struct zone *zone, struct page *page) 222{ 223 return 0; 224} 225#endif 226 227static void bad_page(struct page *page) 228{ 229 static unsigned long resume; 230 static unsigned long nr_shown; 231 static unsigned long nr_unshown; 232 233 /* 234 * Allow a burst of 60 reports, then keep quiet for that minute; 235 * or allow a steady drip of one report per second. 236 */ 237 if (nr_shown == 60) { 238 if (time_before(jiffies, resume)) { 239 nr_unshown++; 240 goto out; 241 } 242 if (nr_unshown) { 243 printk(KERN_ALERT 244 "BUG: Bad page state: %lu messages suppressed\n", 245 nr_unshown); 246 nr_unshown = 0; 247 } 248 nr_shown = 0; 249 } 250 if (nr_shown++ == 0) 251 resume = jiffies + 60 * HZ; 252 253 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n", 254 current->comm, page_to_pfn(page)); 255 printk(KERN_ALERT 256 "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n", 257 page, (void *)page->flags, page_count(page), 258 page_mapcount(page), page->mapping, page->index); 259 260 dump_stack(); 261out: 262 /* Leave bad fields for debug, except PageBuddy could make trouble */ 263 __ClearPageBuddy(page); 264 add_taint(TAINT_BAD_PAGE); 265} 266 267/* 268 * Higher-order pages are called "compound pages". They are structured thusly: 269 * 270 * The first PAGE_SIZE page is called the "head page". 271 * 272 * The remaining PAGE_SIZE pages are called "tail pages". 273 * 274 * All pages have PG_compound set. All pages have their ->private pointing at 275 * the head page (even the head page has this). 276 * 277 * The first tail page's ->lru.next holds the address of the compound page's 278 * put_page() function. Its ->lru.prev holds the order of allocation. 279 * This usage means that zero-order pages may not be compound. 280 */ 281 282static void free_compound_page(struct page *page) 283{ 284 __free_pages_ok(page, compound_order(page)); 285} 286 287void prep_compound_page(struct page *page, unsigned long order) 288{ 289 int i; 290 int nr_pages = 1 << order; 291 292 set_compound_page_dtor(page, free_compound_page); 293 set_compound_order(page, order); 294 __SetPageHead(page); 295 for (i = 1; i < nr_pages; i++) { 296 struct page *p = page + i; 297 298 __SetPageTail(p); 299 p->first_page = page; 300 } 301} 302 303static int destroy_compound_page(struct page *page, unsigned long order) 304{ 305 int i; 306 int nr_pages = 1 << order; 307 int bad = 0; 308 309 if (unlikely(compound_order(page) != order) || 310 unlikely(!PageHead(page))) { 311 bad_page(page); 312 bad++; 313 } 314 315 __ClearPageHead(page); 316 317 for (i = 1; i < nr_pages; i++) { 318 struct page *p = page + i; 319 320 if (unlikely(!PageTail(p) || (p->first_page != page))) { 321 bad_page(page); 322 bad++; 323 } 324 __ClearPageTail(p); 325 } 326 327 return bad; 328} 329 330static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) 331{ 332 int i; 333 334 /* 335 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO 336 * and __GFP_HIGHMEM from hard or soft interrupt context. 337 */ 338 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); 339 for (i = 0; i < (1 << order); i++) 340 clear_highpage(page + i); 341} 342 343static inline void set_page_order(struct page *page, int order) 344{ 345 set_page_private(page, order); 346 __SetPageBuddy(page); 347} 348 349static inline void rmv_page_order(struct page *page) 350{ 351 __ClearPageBuddy(page); 352 set_page_private(page, 0); 353} 354 355/* 356 * Locate the struct page for both the matching buddy in our 357 * pair (buddy1) and the combined O(n+1) page they form (page). 358 * 359 * 1) Any buddy B1 will have an order O twin B2 which satisfies 360 * the following equation: 361 * B2 = B1 ^ (1 << O) 362 * For example, if the starting buddy (buddy2) is #8 its order 363 * 1 buddy is #10: 364 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 365 * 366 * 2) Any buddy B will have an order O+1 parent P which 367 * satisfies the following equation: 368 * P = B & ~(1 << O) 369 * 370 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 371 */ 372static inline struct page * 373__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order) 374{ 375 unsigned long buddy_idx = page_idx ^ (1 << order); 376 377 return page + (buddy_idx - page_idx); 378} 379 380static inline unsigned long 381__find_combined_index(unsigned long page_idx, unsigned int order) 382{ 383 return (page_idx & ~(1 << order)); 384} 385 386/* 387 * This function checks whether a page is free && is the buddy 388 * we can do coalesce a page and its buddy if 389 * (a) the buddy is not in a hole && 390 * (b) the buddy is in the buddy system && 391 * (c) a page and its buddy have the same order && 392 * (d) a page and its buddy are in the same zone. 393 * 394 * For recording whether a page is in the buddy system, we use PG_buddy. 395 * Setting, clearing, and testing PG_buddy is serialized by zone->lock. 396 * 397 * For recording page's order, we use page_private(page). 398 */ 399static inline int page_is_buddy(struct page *page, struct page *buddy, 400 int order) 401{ 402 if (!pfn_valid_within(page_to_pfn(buddy))) 403 return 0; 404 405 if (page_zone_id(page) != page_zone_id(buddy)) 406 return 0; 407 408 if (PageBuddy(buddy) && page_order(buddy) == order) { 409 VM_BUG_ON(page_count(buddy) != 0); 410 return 1; 411 } 412 return 0; 413} 414 415/* 416 * Freeing function for a buddy system allocator. 417 * 418 * The concept of a buddy system is to maintain direct-mapped table 419 * (containing bit values) for memory blocks of various "orders". 420 * The bottom level table contains the map for the smallest allocatable 421 * units of memory (here, pages), and each level above it describes 422 * pairs of units from the levels below, hence, "buddies". 423 * At a high level, all that happens here is marking the table entry 424 * at the bottom level available, and propagating the changes upward 425 * as necessary, plus some accounting needed to play nicely with other 426 * parts of the VM system. 427 * At each level, we keep a list of pages, which are heads of continuous 428 * free pages of length of (1 << order) and marked with PG_buddy. Page's 429 * order is recorded in page_private(page) field. 430 * So when we are allocating or freeing one, we can derive the state of the 431 * other. That is, if we allocate a small block, and both were 432 * free, the remainder of the region must be split into blocks. 433 * If a block is freed, and its buddy is also free, then this 434 * triggers coalescing into a block of larger size. 435 * 436 * -- wli 437 */ 438 439static inline void __free_one_page(struct page *page, 440 struct zone *zone, unsigned int order, 441 int migratetype) 442{ 443 unsigned long page_idx; 444 445 if (unlikely(PageCompound(page))) 446 if (unlikely(destroy_compound_page(page, order))) 447 return; 448 449 VM_BUG_ON(migratetype == -1); 450 451 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); 452 453 VM_BUG_ON(page_idx & ((1 << order) - 1)); 454 VM_BUG_ON(bad_range(zone, page)); 455 456 while (order < MAX_ORDER-1) { 457 unsigned long combined_idx; 458 struct page *buddy; 459 460 buddy = __page_find_buddy(page, page_idx, order); 461 if (!page_is_buddy(page, buddy, order)) 462 break; 463 464 /* Our buddy is free, merge with it and move up one order. */ 465 list_del(&buddy->lru); 466 zone->free_area[order].nr_free--; 467 rmv_page_order(buddy); 468 combined_idx = __find_combined_index(page_idx, order); 469 page = page + (combined_idx - page_idx); 470 page_idx = combined_idx; 471 order++; 472 } 473 set_page_order(page, order); 474 list_add(&page->lru, 475 &zone->free_area[order].free_list[migratetype]); 476 zone->free_area[order].nr_free++; 477} 478 479#ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT 480/* 481 * free_page_mlock() -- clean up attempts to free and mlocked() page. 482 * Page should not be on lru, so no need to fix that up. 483 * free_pages_check() will verify... 484 */ 485static inline void free_page_mlock(struct page *page) 486{ 487 __ClearPageMlocked(page); 488 __dec_zone_page_state(page, NR_MLOCK); 489 __count_vm_event(UNEVICTABLE_MLOCKFREED); 490} 491#else 492static void free_page_mlock(struct page *page) { } 493#endif 494 495static inline int free_pages_check(struct page *page) 496{ 497 if (unlikely(page_mapcount(page) | 498 (page->mapping != NULL) | 499 (atomic_read(&page->_count) != 0) | 500 (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) { 501 bad_page(page); 502 return 1; 503 } 504 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP) 505 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; 506 return 0; 507} 508 509/* 510 * Frees a list of pages. 511 * Assumes all pages on list are in same zone, and of same order. 512 * count is the number of pages to free. 513 * 514 * If the zone was previously in an "all pages pinned" state then look to 515 * see if this freeing clears that state. 516 * 517 * And clear the zone's pages_scanned counter, to hold off the "all pages are 518 * pinned" detection logic. 519 */ 520static void free_pages_bulk(struct zone *zone, int count, 521 struct list_head *list, int order) 522{ 523 spin_lock(&zone->lock); 524 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); 525 zone->pages_scanned = 0; 526 527 __mod_zone_page_state(zone, NR_FREE_PAGES, count << order); 528 while (count--) { 529 struct page *page; 530 531 VM_BUG_ON(list_empty(list)); 532 page = list_entry(list->prev, struct page, lru); 533 /* have to delete it as __free_one_page list manipulates */ 534 list_del(&page->lru); 535 __free_one_page(page, zone, order, page_private(page)); 536 } 537 spin_unlock(&zone->lock); 538} 539 540static void free_one_page(struct zone *zone, struct page *page, int order, 541 int migratetype) 542{ 543 spin_lock(&zone->lock); 544 zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); 545 zone->pages_scanned = 0; 546 547 __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order); 548 __free_one_page(page, zone, order, migratetype); 549 spin_unlock(&zone->lock); 550} 551 552static void __free_pages_ok(struct page *page, unsigned int order) 553{ 554 unsigned long flags; 555 int i; 556 int bad = 0; 557 int clearMlocked = PageMlocked(page); 558 559 for (i = 0 ; i < (1 << order) ; ++i) 560 bad += free_pages_check(page + i); 561 if (bad) 562 return; 563 564 if (!PageHighMem(page)) { 565 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order); 566 debug_check_no_obj_freed(page_address(page), 567 PAGE_SIZE << order); 568 } 569 arch_free_page(page, order); 570 kernel_map_pages(page, 1 << order, 0); 571 572 local_irq_save(flags); 573 if (unlikely(clearMlocked)) 574 free_page_mlock(page); 575 __count_vm_events(PGFREE, 1 << order); 576 free_one_page(page_zone(page), page, order, 577 get_pageblock_migratetype(page)); 578 local_irq_restore(flags); 579} 580 581/* 582 * permit the bootmem allocator to evade page validation on high-order frees 583 */ 584void __meminit __free_pages_bootmem(struct page *page, unsigned int order) 585{ 586 if (order == 0) { 587 __ClearPageReserved(page); 588 set_page_count(page, 0); 589 set_page_refcounted(page); 590 __free_page(page); 591 } else { 592 int loop; 593 594 prefetchw(page); 595 for (loop = 0; loop < BITS_PER_LONG; loop++) { 596 struct page *p = &page[loop]; 597 598 if (loop + 1 < BITS_PER_LONG) 599 prefetchw(p + 1); 600 __ClearPageReserved(p); 601 set_page_count(p, 0); 602 } 603 604 set_page_refcounted(page); 605 __free_pages(page, order); 606 } 607} 608 609 610/* 611 * The order of subdivision here is critical for the IO subsystem. 612 * Please do not alter this order without good reasons and regression 613 * testing. Specifically, as large blocks of memory are subdivided, 614 * the order in which smaller blocks are delivered depends on the order 615 * they're subdivided in this function. This is the primary factor 616 * influencing the order in which pages are delivered to the IO 617 * subsystem according to empirical testing, and this is also justified 618 * by considering the behavior of a buddy system containing a single 619 * large block of memory acted on by a series of small allocations. 620 * This behavior is a critical factor in sglist merging's success. 621 * 622 * -- wli 623 */ 624static inline void expand(struct zone *zone, struct page *page, 625 int low, int high, struct free_area *area, 626 int migratetype) 627{ 628 unsigned long size = 1 << high; 629 630 while (high > low) { 631 area--; 632 high--; 633 size >>= 1; 634 VM_BUG_ON(bad_range(zone, &page[size])); 635 list_add(&page[size].lru, &area->free_list[migratetype]); 636 area->nr_free++; 637 set_page_order(&page[size], high); 638 } 639} 640 641/* 642 * This page is about to be returned from the page allocator 643 */ 644static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) 645{ 646 if (unlikely(page_mapcount(page) | 647 (page->mapping != NULL) | 648 (atomic_read(&page->_count) != 0) | 649 (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) { 650 bad_page(page); 651 return 1; 652 } 653 654 set_page_private(page, 0); 655 set_page_refcounted(page); 656 657 arch_alloc_page(page, order); 658 kernel_map_pages(page, 1 << order, 1); 659 660 if (gfp_flags & __GFP_ZERO) 661 prep_zero_page(page, order, gfp_flags); 662 663 if (order && (gfp_flags & __GFP_COMP)) 664 prep_compound_page(page, order); 665 666 return 0; 667} 668 669/* 670 * Go through the free lists for the given migratetype and remove 671 * the smallest available page from the freelists 672 */ 673static inline 674struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, 675 int migratetype) 676{ 677 unsigned int current_order; 678 struct free_area * area; 679 struct page *page; 680 681 /* Find a page of the appropriate size in the preferred list */ 682 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 683 area = &(zone->free_area[current_order]); 684 if (list_empty(&area->free_list[migratetype])) 685 continue; 686 687 page = list_entry(area->free_list[migratetype].next, 688 struct page, lru); 689 list_del(&page->lru); 690 rmv_page_order(page); 691 area->nr_free--; 692 expand(zone, page, order, current_order, area, migratetype); 693 return page; 694 } 695 696 return NULL; 697} 698 699 700/* 701 * This array describes the order lists are fallen back to when 702 * the free lists for the desirable migrate type are depleted 703 */ 704static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = { 705 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 706 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 707 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, 708 [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */ 709}; 710 711/* 712 * Move the free pages in a range to the free lists of the requested type. 713 * Note that start_page and end_pages are not aligned on a pageblock 714 * boundary. If alignment is required, use move_freepages_block() 715 */ 716static int move_freepages(struct zone *zone, 717 struct page *start_page, struct page *end_page, 718 int migratetype) 719{ 720 struct page *page; 721 unsigned long order; 722 int pages_moved = 0; 723 724#ifndef CONFIG_HOLES_IN_ZONE 725 /* 726 * page_zone is not safe to call in this context when 727 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant 728 * anyway as we check zone boundaries in move_freepages_block(). 729 * Remove at a later date when no bug reports exist related to 730 * grouping pages by mobility 731 */ 732 BUG_ON(page_zone(start_page) != page_zone(end_page)); 733#endif 734 735 for (page = start_page; page <= end_page;) { 736 /* Make sure we are not inadvertently changing nodes */ 737 VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone)); 738 739 if (!pfn_valid_within(page_to_pfn(page))) { 740 page++; 741 continue; 742 } 743 744 if (!PageBuddy(page)) { 745 page++; 746 continue; 747 } 748 749 order = page_order(page); 750 list_del(&page->lru); 751 list_add(&page->lru, 752 &zone->free_area[order].free_list[migratetype]); 753 page += 1 << order; 754 pages_moved += 1 << order; 755 } 756 757 return pages_moved; 758} 759 760static int move_freepages_block(struct zone *zone, struct page *page, 761 int migratetype) 762{ 763 unsigned long start_pfn, end_pfn; 764 struct page *start_page, *end_page; 765 766 start_pfn = page_to_pfn(page); 767 start_pfn = start_pfn & ~(pageblock_nr_pages-1); 768 start_page = pfn_to_page(start_pfn); 769 end_page = start_page + pageblock_nr_pages - 1; 770 end_pfn = start_pfn + pageblock_nr_pages - 1; 771 772 /* Do not cross zone boundaries */ 773 if (start_pfn < zone->zone_start_pfn) 774 start_page = page; 775 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages) 776 return 0; 777 778 return move_freepages(zone, start_page, end_page, migratetype); 779} 780 781/* Remove an element from the buddy allocator from the fallback list */ 782static inline struct page * 783__rmqueue_fallback(struct zone *zone, int order, int start_migratetype) 784{ 785 struct free_area * area; 786 int current_order; 787 struct page *page; 788 int migratetype, i; 789 790 /* Find the largest possible block of pages in the other list */ 791 for (current_order = MAX_ORDER-1; current_order >= order; 792 --current_order) { 793 for (i = 0; i < MIGRATE_TYPES - 1; i++) { 794 migratetype = fallbacks[start_migratetype][i]; 795 796 /* MIGRATE_RESERVE handled later if necessary */ 797 if (migratetype == MIGRATE_RESERVE) 798 continue; 799 800 area = &(zone->free_area[current_order]); 801 if (list_empty(&area->free_list[migratetype])) 802 continue; 803 804 page = list_entry(area->free_list[migratetype].next, 805 struct page, lru); 806 area->nr_free--; 807 808 /* 809 * If breaking a large block of pages, move all free 810 * pages to the preferred allocation list. If falling 811 * back for a reclaimable kernel allocation, be more 812 * agressive about taking ownership of free pages 813 */ 814 if (unlikely(current_order >= (pageblock_order >> 1)) || 815 start_migratetype == MIGRATE_RECLAIMABLE) { 816 unsigned long pages; 817 pages = move_freepages_block(zone, page, 818 start_migratetype); 819 820 /* Claim the whole block if over half of it is free */ 821 if (pages >= (1 << (pageblock_order-1))) 822 set_pageblock_migratetype(page, 823 start_migratetype); 824 825 migratetype = start_migratetype; 826 } 827 828 /* Remove the page from the freelists */ 829 list_del(&page->lru); 830 rmv_page_order(page); 831 832 if (current_order == pageblock_order) 833 set_pageblock_migratetype(page, 834 start_migratetype); 835 836 expand(zone, page, order, current_order, area, migratetype); 837 return page; 838 } 839 } 840 841 return NULL; 842} 843 844/* 845 * Do the hard work of removing an element from the buddy allocator. 846 * Call me with the zone->lock already held. 847 */ 848static struct page *__rmqueue(struct zone *zone, unsigned int order, 849 int migratetype) 850{ 851 struct page *page; 852 853retry_reserve: 854 page = __rmqueue_smallest(zone, order, migratetype); 855 856 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) { 857 page = __rmqueue_fallback(zone, order, migratetype); 858 859 /* 860 * Use MIGRATE_RESERVE rather than fail an allocation. goto 861 * is used because __rmqueue_smallest is an inline function 862 * and we want just one call site 863 */ 864 if (!page) { 865 migratetype = MIGRATE_RESERVE; 866 goto retry_reserve; 867 } 868 } 869 870 return page; 871} 872 873/* 874 * Obtain a specified number of elements from the buddy allocator, all under 875 * a single hold of the lock, for efficiency. Add them to the supplied list. 876 * Returns the number of new pages which were placed at *list. 877 */ 878static int rmqueue_bulk(struct zone *zone, unsigned int order, 879 unsigned long count, struct list_head *list, 880 int migratetype) 881{ 882 int i; 883 884 spin_lock(&zone->lock); 885 for (i = 0; i < count; ++i) { 886 struct page *page = __rmqueue(zone, order, migratetype); 887 if (unlikely(page == NULL)) 888 break; 889 890 /* 891 * Split buddy pages returned by expand() are received here 892 * in physical page order. The page is added to the callers and 893 * list and the list head then moves forward. From the callers 894 * perspective, the linked list is ordered by page number in 895 * some conditions. This is useful for IO devices that can 896 * merge IO requests if the physical pages are ordered 897 * properly. 898 */ 899 list_add(&page->lru, list); 900 set_page_private(page, migratetype); 901 list = &page->lru; 902 } 903 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); 904 spin_unlock(&zone->lock); 905 return i; 906} 907 908#ifdef CONFIG_NUMA 909/* 910 * Called from the vmstat counter updater to drain pagesets of this 911 * currently executing processor on remote nodes after they have 912 * expired. 913 * 914 * Note that this function must be called with the thread pinned to 915 * a single processor. 916 */ 917void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) 918{ 919 unsigned long flags; 920 int to_drain; 921 922 local_irq_save(flags); 923 if (pcp->count >= pcp->batch) 924 to_drain = pcp->batch; 925 else 926 to_drain = pcp->count; 927 free_pages_bulk(zone, to_drain, &pcp->list, 0); 928 pcp->count -= to_drain; 929 local_irq_restore(flags); 930} 931#endif 932 933/* 934 * Drain pages of the indicated processor. 935 * 936 * The processor must either be the current processor and the 937 * thread pinned to the current processor or a processor that 938 * is not online. 939 */ 940static void drain_pages(unsigned int cpu) 941{ 942 unsigned long flags; 943 struct zone *zone; 944 945 for_each_populated_zone(zone) { 946 struct per_cpu_pageset *pset; 947 struct per_cpu_pages *pcp; 948 949 pset = zone_pcp(zone, cpu); 950 951 pcp = &pset->pcp; 952 local_irq_save(flags); 953 free_pages_bulk(zone, pcp->count, &pcp->list, 0); 954 pcp->count = 0; 955 local_irq_restore(flags); 956 } 957} 958 959/* 960 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 961 */ 962void drain_local_pages(void *arg) 963{ 964 drain_pages(smp_processor_id()); 965} 966 967/* 968 * Spill all the per-cpu pages from all CPUs back into the buddy allocator 969 */ 970void drain_all_pages(void) 971{ 972 on_each_cpu(drain_local_pages, NULL, 1); 973} 974 975#ifdef CONFIG_HIBERNATION 976 977void mark_free_pages(struct zone *zone) 978{ 979 unsigned long pfn, max_zone_pfn; 980 unsigned long flags; 981 int order, t; 982 struct list_head *curr; 983 984 if (!zone->spanned_pages) 985 return; 986 987 spin_lock_irqsave(&zone->lock, flags); 988 989 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; 990 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 991 if (pfn_valid(pfn)) { 992 struct page *page = pfn_to_page(pfn); 993 994 if (!swsusp_page_is_forbidden(page)) 995 swsusp_unset_page_free(page); 996 } 997 998 for_each_migratetype_order(order, t) { 999 list_for_each(curr, &zone->free_area[order].free_list[t]) { 1000 unsigned long i; 1001 1002 pfn = page_to_pfn(list_entry(curr, struct page, lru)); 1003 for (i = 0; i < (1UL << order); i++) 1004 swsusp_set_page_free(pfn_to_page(pfn + i)); 1005 } 1006 } 1007 spin_unlock_irqrestore(&zone->lock, flags); 1008} 1009#endif /* CONFIG_PM */ 1010 1011/* 1012 * Free a 0-order page 1013 */ 1014static void free_hot_cold_page(struct page *page, int cold) 1015{ 1016 struct zone *zone = page_zone(page); 1017 struct per_cpu_pages *pcp; 1018 unsigned long flags; 1019 int clearMlocked = PageMlocked(page); 1020 1021 if (PageAnon(page)) 1022 page->mapping = NULL; 1023 if (free_pages_check(page)) 1024 return; 1025 1026 if (!PageHighMem(page)) { 1027 debug_check_no_locks_freed(page_address(page), PAGE_SIZE); 1028 debug_check_no_obj_freed(page_address(page), PAGE_SIZE); 1029 } 1030 arch_free_page(page, 0); 1031 kernel_map_pages(page, 1, 0); 1032 1033 pcp = &zone_pcp(zone, get_cpu())->pcp; 1034 set_page_private(page, get_pageblock_migratetype(page)); 1035 local_irq_save(flags); 1036 if (unlikely(clearMlocked)) 1037 free_page_mlock(page); 1038 __count_vm_event(PGFREE); 1039 1040 if (cold) 1041 list_add_tail(&page->lru, &pcp->list); 1042 else 1043 list_add(&page->lru, &pcp->list); 1044 pcp->count++; 1045 if (pcp->count >= pcp->high) { 1046 free_pages_bulk(zone, pcp->batch, &pcp->list, 0); 1047 pcp->count -= pcp->batch; 1048 } 1049 local_irq_restore(flags); 1050 put_cpu(); 1051} 1052 1053void free_hot_page(struct page *page) 1054{ 1055 free_hot_cold_page(page, 0); 1056} 1057 1058void free_cold_page(struct page *page) 1059{ 1060 free_hot_cold_page(page, 1); 1061} 1062 1063/* 1064 * split_page takes a non-compound higher-order page, and splits it into 1065 * n (1<<order) sub-pages: page[0..n] 1066 * Each sub-page must be freed individually. 1067 * 1068 * Note: this is probably too low level an operation for use in drivers. 1069 * Please consult with lkml before using this in your driver. 1070 */ 1071void split_page(struct page *page, unsigned int order) 1072{ 1073 int i; 1074 1075 VM_BUG_ON(PageCompound(page)); 1076 VM_BUG_ON(!page_count(page)); 1077 for (i = 1; i < (1 << order); i++) 1078 set_page_refcounted(page + i); 1079} 1080 1081/* 1082 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 1083 * we cheat by calling it from here, in the order > 0 path. Saves a branch 1084 * or two. 1085 */ 1086static inline 1087struct page *buffered_rmqueue(struct zone *preferred_zone, 1088 struct zone *zone, int order, gfp_t gfp_flags, 1089 int migratetype) 1090{ 1091 unsigned long flags; 1092 struct page *page; 1093 int cold = !!(gfp_flags & __GFP_COLD); 1094 int cpu; 1095 1096again: 1097 cpu = get_cpu(); 1098 if (likely(order == 0)) { 1099 struct per_cpu_pages *pcp; 1100 1101 pcp = &zone_pcp(zone, cpu)->pcp; 1102 local_irq_save(flags); 1103 if (!pcp->count) { 1104 pcp->count = rmqueue_bulk(zone, 0, 1105 pcp->batch, &pcp->list, migratetype); 1106 if (unlikely(!pcp->count)) 1107 goto failed; 1108 } 1109 1110 /* Find a page of the appropriate migrate type */ 1111 if (cold) { 1112 list_for_each_entry_reverse(page, &pcp->list, lru) 1113 if (page_private(page) == migratetype) 1114 break; 1115 } else { 1116 list_for_each_entry(page, &pcp->list, lru) 1117 if (page_private(page) == migratetype) 1118 break; 1119 } 1120 1121 /* Allocate more to the pcp list if necessary */ 1122 if (unlikely(&page->lru == &pcp->list)) { 1123 pcp->count += rmqueue_bulk(zone, 0, 1124 pcp->batch, &pcp->list, migratetype); 1125 page = list_entry(pcp->list.next, struct page, lru); 1126 } 1127 1128 list_del(&page->lru); 1129 pcp->count--; 1130 } else { 1131 spin_lock_irqsave(&zone->lock, flags); 1132 page = __rmqueue(zone, order, migratetype); 1133 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order)); 1134 spin_unlock(&zone->lock); 1135 if (!page) 1136 goto failed; 1137 } 1138 1139 __count_zone_vm_events(PGALLOC, zone, 1 << order); 1140 zone_statistics(preferred_zone, zone); 1141 local_irq_restore(flags); 1142 put_cpu(); 1143 1144 VM_BUG_ON(bad_range(zone, page)); 1145 if (prep_new_page(page, order, gfp_flags)) 1146 goto again; 1147 return page; 1148 1149failed: 1150 local_irq_restore(flags); 1151 put_cpu(); 1152 return NULL; 1153} 1154 1155/* The ALLOC_WMARK bits are used as an index to zone->watermark */ 1156#define ALLOC_WMARK_MIN WMARK_MIN 1157#define ALLOC_WMARK_LOW WMARK_LOW 1158#define ALLOC_WMARK_HIGH WMARK_HIGH 1159#define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 1160 1161/* Mask to get the watermark bits */ 1162#define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 1163 1164#define ALLOC_HARDER 0x10 /* try to alloc harder */ 1165#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 1166#define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 1167 1168#ifdef CONFIG_FAIL_PAGE_ALLOC 1169 1170static struct fail_page_alloc_attr { 1171 struct fault_attr attr; 1172 1173 u32 ignore_gfp_highmem; 1174 u32 ignore_gfp_wait; 1175 u32 min_order; 1176 1177#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1178 1179 struct dentry *ignore_gfp_highmem_file; 1180 struct dentry *ignore_gfp_wait_file; 1181 struct dentry *min_order_file; 1182 1183#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1184 1185} fail_page_alloc = { 1186 .attr = FAULT_ATTR_INITIALIZER, 1187 .ignore_gfp_wait = 1, 1188 .ignore_gfp_highmem = 1, 1189 .min_order = 1, 1190}; 1191 1192static int __init setup_fail_page_alloc(char *str) 1193{ 1194 return setup_fault_attr(&fail_page_alloc.attr, str); 1195} 1196__setup("fail_page_alloc=", setup_fail_page_alloc); 1197 1198static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1199{ 1200 if (order < fail_page_alloc.min_order) 1201 return 0; 1202 if (gfp_mask & __GFP_NOFAIL) 1203 return 0; 1204 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 1205 return 0; 1206 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) 1207 return 0; 1208 1209 return should_fail(&fail_page_alloc.attr, 1 << order); 1210} 1211 1212#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1213 1214static int __init fail_page_alloc_debugfs(void) 1215{ 1216 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; 1217 struct dentry *dir; 1218 int err; 1219 1220 err = init_fault_attr_dentries(&fail_page_alloc.attr, 1221 "fail_page_alloc"); 1222 if (err) 1223 return err; 1224 dir = fail_page_alloc.attr.dentries.dir; 1225 1226 fail_page_alloc.ignore_gfp_wait_file = 1227 debugfs_create_bool("ignore-gfp-wait", mode, dir, 1228 &fail_page_alloc.ignore_gfp_wait); 1229 1230 fail_page_alloc.ignore_gfp_highmem_file = 1231 debugfs_create_bool("ignore-gfp-highmem", mode, dir, 1232 &fail_page_alloc.ignore_gfp_highmem); 1233 fail_page_alloc.min_order_file = 1234 debugfs_create_u32("min-order", mode, dir, 1235 &fail_page_alloc.min_order); 1236 1237 if (!fail_page_alloc.ignore_gfp_wait_file || 1238 !fail_page_alloc.ignore_gfp_highmem_file || 1239 !fail_page_alloc.min_order_file) { 1240 err = -ENOMEM; 1241 debugfs_remove(fail_page_alloc.ignore_gfp_wait_file); 1242 debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file); 1243 debugfs_remove(fail_page_alloc.min_order_file); 1244 cleanup_fault_attr_dentries(&fail_page_alloc.attr); 1245 } 1246 1247 return err; 1248} 1249 1250late_initcall(fail_page_alloc_debugfs); 1251 1252#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1253 1254#else /* CONFIG_FAIL_PAGE_ALLOC */ 1255 1256static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1257{ 1258 return 0; 1259} 1260 1261#endif /* CONFIG_FAIL_PAGE_ALLOC */ 1262 1263/* 1264 * Return 1 if free pages are above 'mark'. This takes into account the order 1265 * of the allocation. 1266 */ 1267int zone_watermark_ok(struct zone *z, int order, unsigned long mark, 1268 int classzone_idx, int alloc_flags) 1269{ 1270 /* free_pages my go negative - that's OK */ 1271 long min = mark; 1272 long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1; 1273 int o; 1274 1275 if (alloc_flags & ALLOC_HIGH) 1276 min -= min / 2; 1277 if (alloc_flags & ALLOC_HARDER) 1278 min -= min / 4; 1279 1280 if (free_pages <= min + z->lowmem_reserve[classzone_idx]) 1281 return 0; 1282 for (o = 0; o < order; o++) { 1283 /* At the next order, this order's pages become unavailable */ 1284 free_pages -= z->free_area[o].nr_free << o; 1285 1286 /* Require fewer higher order pages to be free */ 1287 min >>= 1; 1288 1289 if (free_pages <= min) 1290 return 0; 1291 } 1292 return 1; 1293} 1294 1295#ifdef CONFIG_NUMA 1296/* 1297 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to 1298 * skip over zones that are not allowed by the cpuset, or that have 1299 * been recently (in last second) found to be nearly full. See further 1300 * comments in mmzone.h. Reduces cache footprint of zonelist scans 1301 * that have to skip over a lot of full or unallowed zones. 1302 * 1303 * If the zonelist cache is present in the passed in zonelist, then 1304 * returns a pointer to the allowed node mask (either the current 1305 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].) 1306 * 1307 * If the zonelist cache is not available for this zonelist, does 1308 * nothing and returns NULL. 1309 * 1310 * If the fullzones BITMAP in the zonelist cache is stale (more than 1311 * a second since last zap'd) then we zap it out (clear its bits.) 1312 * 1313 * We hold off even calling zlc_setup, until after we've checked the 1314 * first zone in the zonelist, on the theory that most allocations will 1315 * be satisfied from that first zone, so best to examine that zone as 1316 * quickly as we can. 1317 */ 1318static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1319{ 1320 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1321 nodemask_t *allowednodes; /* zonelist_cache approximation */ 1322 1323 zlc = zonelist->zlcache_ptr; 1324 if (!zlc) 1325 return NULL; 1326 1327 if (time_after(jiffies, zlc->last_full_zap + HZ)) { 1328 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1329 zlc->last_full_zap = jiffies; 1330 } 1331 1332 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? 1333 &cpuset_current_mems_allowed : 1334 &node_states[N_HIGH_MEMORY]; 1335 return allowednodes; 1336} 1337 1338/* 1339 * Given 'z' scanning a zonelist, run a couple of quick checks to see 1340 * if it is worth looking at further for free memory: 1341 * 1) Check that the zone isn't thought to be full (doesn't have its 1342 * bit set in the zonelist_cache fullzones BITMAP). 1343 * 2) Check that the zones node (obtained from the zonelist_cache 1344 * z_to_n[] mapping) is allowed in the passed in allowednodes mask. 1345 * Return true (non-zero) if zone is worth looking at further, or 1346 * else return false (zero) if it is not. 1347 * 1348 * This check -ignores- the distinction between various watermarks, 1349 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is 1350 * found to be full for any variation of these watermarks, it will 1351 * be considered full for up to one second by all requests, unless 1352 * we are so low on memory on all allowed nodes that we are forced 1353 * into the second scan of the zonelist. 1354 * 1355 * In the second scan we ignore this zonelist cache and exactly 1356 * apply the watermarks to all zones, even it is slower to do so. 1357 * We are low on memory in the second scan, and should leave no stone 1358 * unturned looking for a free page. 1359 */ 1360static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1361 nodemask_t *allowednodes) 1362{ 1363 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1364 int i; /* index of *z in zonelist zones */ 1365 int n; /* node that zone *z is on */ 1366 1367 zlc = zonelist->zlcache_ptr; 1368 if (!zlc) 1369 return 1; 1370 1371 i = z - zonelist->_zonerefs; 1372 n = zlc->z_to_n[i]; 1373 1374 /* This zone is worth trying if it is allowed but not full */ 1375 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); 1376} 1377 1378/* 1379 * Given 'z' scanning a zonelist, set the corresponding bit in 1380 * zlc->fullzones, so that subsequent attempts to allocate a page 1381 * from that zone don't waste time re-examining it. 1382 */ 1383static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1384{ 1385 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1386 int i; /* index of *z in zonelist zones */ 1387 1388 zlc = zonelist->zlcache_ptr; 1389 if (!zlc) 1390 return; 1391 1392 i = z - zonelist->_zonerefs; 1393 1394 set_bit(i, zlc->fullzones); 1395} 1396 1397#else /* CONFIG_NUMA */ 1398 1399static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1400{ 1401 return NULL; 1402} 1403 1404static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1405 nodemask_t *allowednodes) 1406{ 1407 return 1; 1408} 1409 1410static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1411{ 1412} 1413#endif /* CONFIG_NUMA */ 1414 1415/* 1416 * get_page_from_freelist goes through the zonelist trying to allocate 1417 * a page. 1418 */ 1419static struct page * 1420get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order, 1421 struct zonelist *zonelist, int high_zoneidx, int alloc_flags, 1422 struct zone *preferred_zone, int migratetype) 1423{ 1424 struct zoneref *z; 1425 struct page *page = NULL; 1426 int classzone_idx; 1427 struct zone *zone; 1428 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ 1429 int zlc_active = 0; /* set if using zonelist_cache */ 1430 int did_zlc_setup = 0; /* just call zlc_setup() one time */ 1431 1432 classzone_idx = zone_idx(preferred_zone); 1433zonelist_scan: 1434 /* 1435 * Scan zonelist, looking for a zone with enough free. 1436 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1437 */ 1438 for_each_zone_zonelist_nodemask(zone, z, zonelist, 1439 high_zoneidx, nodemask) { 1440 if (NUMA_BUILD && zlc_active && 1441 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 1442 continue; 1443 if ((alloc_flags & ALLOC_CPUSET) && 1444 !cpuset_zone_allowed_softwall(zone, gfp_mask)) 1445 goto try_next_zone; 1446 1447 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK); 1448 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { 1449 unsigned long mark; 1450 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK]; 1451 if (!zone_watermark_ok(zone, order, mark, 1452 classzone_idx, alloc_flags)) { 1453 if (!zone_reclaim_mode || 1454 !zone_reclaim(zone, gfp_mask, order)) 1455 goto this_zone_full; 1456 } 1457 } 1458 1459 page = buffered_rmqueue(preferred_zone, zone, order, 1460 gfp_mask, migratetype); 1461 if (page) 1462 break; 1463this_zone_full: 1464 if (NUMA_BUILD) 1465 zlc_mark_zone_full(zonelist, z); 1466try_next_zone: 1467 if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) { 1468 /* 1469 * we do zlc_setup after the first zone is tried but only 1470 * if there are multiple nodes make it worthwhile 1471 */ 1472 allowednodes = zlc_setup(zonelist, alloc_flags); 1473 zlc_active = 1; 1474 did_zlc_setup = 1; 1475 } 1476 } 1477 1478 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) { 1479 /* Disable zlc cache for second zonelist scan */ 1480 zlc_active = 0; 1481 goto zonelist_scan; 1482 } 1483 return page; 1484} 1485 1486static inline int 1487should_alloc_retry(gfp_t gfp_mask, unsigned int order, 1488 unsigned long pages_reclaimed) 1489{ 1490 /* Do not loop if specifically requested */ 1491 if (gfp_mask & __GFP_NORETRY) 1492 return 0; 1493 1494 /* 1495 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER 1496 * means __GFP_NOFAIL, but that may not be true in other 1497 * implementations. 1498 */ 1499 if (order <= PAGE_ALLOC_COSTLY_ORDER) 1500 return 1; 1501 1502 /* 1503 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is 1504 * specified, then we retry until we no longer reclaim any pages 1505 * (above), or we've reclaimed an order of pages at least as 1506 * large as the allocation's order. In both cases, if the 1507 * allocation still fails, we stop retrying. 1508 */ 1509 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order)) 1510 return 1; 1511 1512 /* 1513 * Don't let big-order allocations loop unless the caller 1514 * explicitly requests that. 1515 */ 1516 if (gfp_mask & __GFP_NOFAIL) 1517 return 1; 1518 1519 return 0; 1520} 1521 1522static inline struct page * 1523__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, 1524 struct zonelist *zonelist, enum zone_type high_zoneidx, 1525 nodemask_t *nodemask, struct zone *preferred_zone, 1526 int migratetype) 1527{ 1528 struct page *page; 1529 1530 /* Acquire the OOM killer lock for the zones in zonelist */ 1531 if (!try_set_zone_oom(zonelist, gfp_mask)) { 1532 schedule_timeout_uninterruptible(1); 1533 return NULL; 1534 } 1535 1536 /* 1537 * Go through the zonelist yet one more time, keep very high watermark 1538 * here, this is only to catch a parallel oom killing, we must fail if 1539 * we're still under heavy pressure. 1540 */ 1541 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, 1542 order, zonelist, high_zoneidx, 1543 ALLOC_WMARK_HIGH|ALLOC_CPUSET, 1544 preferred_zone, migratetype); 1545 if (page) 1546 goto out; 1547 1548 /* The OOM killer will not help higher order allocs */ 1549 if (order > PAGE_ALLOC_COSTLY_ORDER) 1550 goto out; 1551 1552 /* Exhausted what can be done so it's blamo time */ 1553 out_of_memory(zonelist, gfp_mask, order); 1554 1555out: 1556 clear_zonelist_oom(zonelist, gfp_mask); 1557 return page; 1558} 1559 1560/* The really slow allocator path where we enter direct reclaim */ 1561static inline struct page * 1562__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order, 1563 struct zonelist *zonelist, enum zone_type high_zoneidx, 1564 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, 1565 int migratetype, unsigned long *did_some_progress) 1566{ 1567 struct page *page = NULL; 1568 struct reclaim_state reclaim_state; 1569 struct task_struct *p = current; 1570 1571 cond_resched(); 1572 1573 /* We now go into synchronous reclaim */ 1574 cpuset_memory_pressure_bump(); 1575 1576 /* 1577 * The task's cpuset might have expanded its set of allowable nodes 1578 */ 1579 p->flags |= PF_MEMALLOC; 1580 lockdep_set_current_reclaim_state(gfp_mask); 1581 reclaim_state.reclaimed_slab = 0; 1582 p->reclaim_state = &reclaim_state; 1583 1584 *did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask); 1585 1586 p->reclaim_state = NULL; 1587 lockdep_clear_current_reclaim_state(); 1588 p->flags &= ~PF_MEMALLOC; 1589 1590 cond_resched(); 1591 1592 if (order != 0) 1593 drain_all_pages(); 1594 1595 if (likely(*did_some_progress)) 1596 page = get_page_from_freelist(gfp_mask, nodemask, order, 1597 zonelist, high_zoneidx, 1598 alloc_flags, preferred_zone, 1599 migratetype); 1600 return page; 1601} 1602 1603/* 1604 * This is called in the allocator slow-path if the allocation request is of 1605 * sufficient urgency to ignore watermarks and take other desperate measures 1606 */ 1607static inline struct page * 1608__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order, 1609 struct zonelist *zonelist, enum zone_type high_zoneidx, 1610 nodemask_t *nodemask, struct zone *preferred_zone, 1611 int migratetype) 1612{ 1613 struct page *page; 1614 1615 do { 1616 page = get_page_from_freelist(gfp_mask, nodemask, order, 1617 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS, 1618 preferred_zone, migratetype); 1619 1620 if (!page && gfp_mask & __GFP_NOFAIL) 1621 congestion_wait(WRITE, HZ/50); 1622 } while (!page && (gfp_mask & __GFP_NOFAIL)); 1623 1624 return page; 1625} 1626 1627static inline 1628void wake_all_kswapd(unsigned int order, struct zonelist *zonelist, 1629 enum zone_type high_zoneidx) 1630{ 1631 struct zoneref *z; 1632 struct zone *zone; 1633 1634 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) 1635 wakeup_kswapd(zone, order); 1636} 1637 1638static inline int 1639gfp_to_alloc_flags(gfp_t gfp_mask) 1640{ 1641 struct task_struct *p = current; 1642 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; 1643 const gfp_t wait = gfp_mask & __GFP_WAIT; 1644 1645 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */ 1646 BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH); 1647 1648 /* 1649 * The caller may dip into page reserves a bit more if the caller 1650 * cannot run direct reclaim, or if the caller has realtime scheduling 1651 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will 1652 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). 1653 */ 1654 alloc_flags |= (gfp_mask & __GFP_HIGH); 1655 1656 if (!wait) { 1657 alloc_flags |= ALLOC_HARDER; 1658 /* 1659 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. 1660 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1661 */ 1662 alloc_flags &= ~ALLOC_CPUSET; 1663 } else if (unlikely(rt_task(p))) 1664 alloc_flags |= ALLOC_HARDER; 1665 1666 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) { 1667 if (!in_interrupt() && 1668 ((p->flags & PF_MEMALLOC) || 1669 unlikely(test_thread_flag(TIF_MEMDIE)))) 1670 alloc_flags |= ALLOC_NO_WATERMARKS; 1671 } 1672 1673 return alloc_flags; 1674} 1675 1676static inline struct page * 1677__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, 1678 struct zonelist *zonelist, enum zone_type high_zoneidx, 1679 nodemask_t *nodemask, struct zone *preferred_zone, 1680 int migratetype) 1681{ 1682 const gfp_t wait = gfp_mask & __GFP_WAIT; 1683 struct page *page = NULL; 1684 int alloc_flags; 1685 unsigned long pages_reclaimed = 0; 1686 unsigned long did_some_progress; 1687 struct task_struct *p = current; 1688 1689 /* 1690 * In the slowpath, we sanity check order to avoid ever trying to 1691 * reclaim >= MAX_ORDER areas which will never succeed. Callers may 1692 * be using allocators in order of preference for an area that is 1693 * too large. 1694 */ 1695 if (WARN_ON_ONCE(order >= MAX_ORDER)) 1696 return NULL; 1697 1698 /* 1699 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and 1700 * __GFP_NOWARN set) should not cause reclaim since the subsystem 1701 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim 1702 * using a larger set of nodes after it has established that the 1703 * allowed per node queues are empty and that nodes are 1704 * over allocated. 1705 */ 1706 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) 1707 goto nopage; 1708 1709 wake_all_kswapd(order, zonelist, high_zoneidx); 1710 1711 /* 1712 * OK, we're below the kswapd watermark and have kicked background 1713 * reclaim. Now things get more complex, so set up alloc_flags according 1714 * to how we want to proceed. 1715 */ 1716 alloc_flags = gfp_to_alloc_flags(gfp_mask); 1717 1718restart: 1719 /* This is the last chance, in general, before the goto nopage. */ 1720 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, 1721 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS, 1722 preferred_zone, migratetype); 1723 if (page) 1724 goto got_pg; 1725 1726rebalance: 1727 /* Allocate without watermarks if the context allows */ 1728 if (alloc_flags & ALLOC_NO_WATERMARKS) { 1729 page = __alloc_pages_high_priority(gfp_mask, order, 1730 zonelist, high_zoneidx, nodemask, 1731 preferred_zone, migratetype); 1732 if (page) 1733 goto got_pg; 1734 } 1735 1736 /* Atomic allocations - we can't balance anything */ 1737 if (!wait) 1738 goto nopage; 1739 1740 /* Avoid recursion of direct reclaim */ 1741 if (p->flags & PF_MEMALLOC) 1742 goto nopage; 1743 1744 /* Try direct reclaim and then allocating */ 1745 page = __alloc_pages_direct_reclaim(gfp_mask, order, 1746 zonelist, high_zoneidx, 1747 nodemask, 1748 alloc_flags, preferred_zone, 1749 migratetype, &did_some_progress); 1750 if (page) 1751 goto got_pg; 1752 1753 /* 1754 * If we failed to make any progress reclaiming, then we are 1755 * running out of options and have to consider going OOM 1756 */ 1757 if (!did_some_progress) { 1758 if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { 1759 page = __alloc_pages_may_oom(gfp_mask, order, 1760 zonelist, high_zoneidx, 1761 nodemask, preferred_zone, 1762 migratetype); 1763 if (page) 1764 goto got_pg; 1765 1766 /* 1767 * The OOM killer does not trigger for high-order allocations 1768 * but if no progress is being made, there are no other 1769 * options and retrying is unlikely to help 1770 */ 1771 if (order > PAGE_ALLOC_COSTLY_ORDER) 1772 goto nopage; 1773 1774 goto restart; 1775 } 1776 } 1777 1778 /* Check if we should retry the allocation */ 1779 pages_reclaimed += did_some_progress; 1780 if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) { 1781 /* Wait for some write requests to complete then retry */ 1782 congestion_wait(WRITE, HZ/50); 1783 goto rebalance; 1784 } 1785 1786nopage: 1787 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { 1788 printk(KERN_WARNING "%s: page allocation failure." 1789 " order:%d, mode:0x%x\n", 1790 p->comm, order, gfp_mask); 1791 dump_stack(); 1792 show_mem(); 1793 } 1794got_pg: 1795 return page; 1796 1797} 1798 1799/* 1800 * This is the 'heart' of the zoned buddy allocator. 1801 */ 1802struct page * 1803__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, 1804 struct zonelist *zonelist, nodemask_t *nodemask) 1805{ 1806 enum zone_type high_zoneidx = gfp_zone(gfp_mask); 1807 struct zone *preferred_zone; 1808 struct page *page; 1809 int migratetype = allocflags_to_migratetype(gfp_mask); 1810 1811 lockdep_trace_alloc(gfp_mask); 1812 1813 might_sleep_if(gfp_mask & __GFP_WAIT); 1814 1815 if (should_fail_alloc_page(gfp_mask, order)) 1816 return NULL; 1817 1818 /* 1819 * Check the zones suitable for the gfp_mask contain at least one 1820 * valid zone. It's possible to have an empty zonelist as a result 1821 * of GFP_THISNODE and a memoryless node 1822 */ 1823 if (unlikely(!zonelist->_zonerefs->zone)) 1824 return NULL; 1825 1826 /* The preferred zone is used for statistics later */ 1827 first_zones_zonelist(zonelist, high_zoneidx, nodemask, &preferred_zone); 1828 if (!preferred_zone) 1829 return NULL; 1830 1831 /* First allocation attempt */ 1832 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order, 1833 zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET, 1834 preferred_zone, migratetype); 1835 if (unlikely(!page)) 1836 page = __alloc_pages_slowpath(gfp_mask, order, 1837 zonelist, high_zoneidx, nodemask, 1838 preferred_zone, migratetype); 1839 1840 return page; 1841} 1842EXPORT_SYMBOL(__alloc_pages_nodemask); 1843 1844/* 1845 * Common helper functions. 1846 */ 1847unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 1848{ 1849 struct page * page; 1850 page = alloc_pages(gfp_mask, order); 1851 if (!page) 1852 return 0; 1853 return (unsigned long) page_address(page); 1854} 1855 1856EXPORT_SYMBOL(__get_free_pages); 1857 1858unsigned long get_zeroed_page(gfp_t gfp_mask) 1859{ 1860 struct page * page; 1861 1862 /* 1863 * get_zeroed_page() returns a 32-bit address, which cannot represent 1864 * a highmem page 1865 */ 1866 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 1867 1868 page = alloc_pages(gfp_mask | __GFP_ZERO, 0); 1869 if (page) 1870 return (unsigned long) page_address(page); 1871 return 0; 1872} 1873 1874EXPORT_SYMBOL(get_zeroed_page); 1875 1876void __pagevec_free(struct pagevec *pvec) 1877{ 1878 int i = pagevec_count(pvec); 1879 1880 while (--i >= 0) 1881 free_hot_cold_page(pvec->pages[i], pvec->cold); 1882} 1883 1884void __free_pages(struct page *page, unsigned int order) 1885{ 1886 if (put_page_testzero(page)) { 1887 if (order == 0) 1888 free_hot_page(page); 1889 else 1890 __free_pages_ok(page, order); 1891 } 1892} 1893 1894EXPORT_SYMBOL(__free_pages); 1895 1896void free_pages(unsigned long addr, unsigned int order) 1897{ 1898 if (addr != 0) { 1899 VM_BUG_ON(!virt_addr_valid((void *)addr)); 1900 __free_pages(virt_to_page((void *)addr), order); 1901 } 1902} 1903 1904EXPORT_SYMBOL(free_pages); 1905 1906/** 1907 * alloc_pages_exact - allocate an exact number physically-contiguous pages. 1908 * @size: the number of bytes to allocate 1909 * @gfp_mask: GFP flags for the allocation 1910 * 1911 * This function is similar to alloc_pages(), except that it allocates the 1912 * minimum number of pages to satisfy the request. alloc_pages() can only 1913 * allocate memory in power-of-two pages. 1914 * 1915 * This function is also limited by MAX_ORDER. 1916 * 1917 * Memory allocated by this function must be released by free_pages_exact(). 1918 */ 1919void *alloc_pages_exact(size_t size, gfp_t gfp_mask) 1920{ 1921 unsigned int order = get_order(size); 1922 unsigned long addr; 1923 1924 addr = __get_free_pages(gfp_mask, order); 1925 if (addr) { 1926 unsigned long alloc_end = addr + (PAGE_SIZE << order); 1927 unsigned long used = addr + PAGE_ALIGN(size); 1928 1929 split_page(virt_to_page(addr), order); 1930 while (used < alloc_end) { 1931 free_page(used); 1932 used += PAGE_SIZE; 1933 } 1934 } 1935 1936 return (void *)addr; 1937} 1938EXPORT_SYMBOL(alloc_pages_exact); 1939 1940/** 1941 * free_pages_exact - release memory allocated via alloc_pages_exact() 1942 * @virt: the value returned by alloc_pages_exact. 1943 * @size: size of allocation, same value as passed to alloc_pages_exact(). 1944 * 1945 * Release the memory allocated by a previous call to alloc_pages_exact. 1946 */ 1947void free_pages_exact(void *virt, size_t size) 1948{ 1949 unsigned long addr = (unsigned long)virt; 1950 unsigned long end = addr + PAGE_ALIGN(size); 1951 1952 while (addr < end) { 1953 free_page(addr); 1954 addr += PAGE_SIZE; 1955 } 1956} 1957EXPORT_SYMBOL(free_pages_exact); 1958 1959static unsigned int nr_free_zone_pages(int offset) 1960{ 1961 struct zoneref *z; 1962 struct zone *zone; 1963 1964 /* Just pick one node, since fallback list is circular */ 1965 unsigned int sum = 0; 1966 1967 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); 1968 1969 for_each_zone_zonelist(zone, z, zonelist, offset) { 1970 unsigned long size = zone->present_pages; 1971 unsigned long high = high_wmark_pages(zone); 1972 if (size > high) 1973 sum += size - high; 1974 } 1975 1976 return sum; 1977} 1978 1979/* 1980 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL 1981 */ 1982unsigned int nr_free_buffer_pages(void) 1983{ 1984 return nr_free_zone_pages(gfp_zone(GFP_USER)); 1985} 1986EXPORT_SYMBOL_GPL(nr_free_buffer_pages); 1987 1988/* 1989 * Amount of free RAM allocatable within all zones 1990 */ 1991unsigned int nr_free_pagecache_pages(void) 1992{ 1993 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); 1994} 1995 1996static inline void show_node(struct zone *zone) 1997{ 1998 if (NUMA_BUILD) 1999 printk("Node %d ", zone_to_nid(zone)); 2000} 2001 2002void si_meminfo(struct sysinfo *val) 2003{ 2004 val->totalram = totalram_pages; 2005 val->sharedram = 0; 2006 val->freeram = global_page_state(NR_FREE_PAGES); 2007 val->bufferram = nr_blockdev_pages(); 2008 val->totalhigh = totalhigh_pages; 2009 val->freehigh = nr_free_highpages(); 2010 val->mem_unit = PAGE_SIZE; 2011} 2012 2013EXPORT_SYMBOL(si_meminfo); 2014 2015#ifdef CONFIG_NUMA 2016void si_meminfo_node(struct sysinfo *val, int nid) 2017{ 2018 pg_data_t *pgdat = NODE_DATA(nid); 2019 2020 val->totalram = pgdat->node_present_pages; 2021 val->freeram = node_page_state(nid, NR_FREE_PAGES); 2022#ifdef CONFIG_HIGHMEM 2023 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; 2024 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], 2025 NR_FREE_PAGES); 2026#else 2027 val->totalhigh = 0; 2028 val->freehigh = 0; 2029#endif 2030 val->mem_unit = PAGE_SIZE; 2031} 2032#endif 2033 2034#define K(x) ((x) << (PAGE_SHIFT-10)) 2035 2036/* 2037 * Show free area list (used inside shift_scroll-lock stuff) 2038 * We also calculate the percentage fragmentation. We do this by counting the 2039 * memory on each free list with the exception of the first item on the list. 2040 */ 2041void show_free_areas(void) 2042{ 2043 int cpu; 2044 struct zone *zone; 2045 2046 for_each_populated_zone(zone) { 2047 show_node(zone); 2048 printk("%s per-cpu:\n", zone->name); 2049 2050 for_each_online_cpu(cpu) { 2051 struct per_cpu_pageset *pageset; 2052 2053 pageset = zone_pcp(zone, cpu); 2054 2055 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n", 2056 cpu, pageset->pcp.high, 2057 pageset->pcp.batch, pageset->pcp.count); 2058 } 2059 } 2060 2061 printk("Active_anon:%lu active_file:%lu inactive_anon:%lu\n" 2062 " inactive_file:%lu" 2063//TODO: check/adjust line lengths 2064#ifdef CONFIG_UNEVICTABLE_LRU 2065 " unevictable:%lu" 2066#endif 2067 " dirty:%lu writeback:%lu unstable:%lu\n" 2068 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n", 2069 global_page_state(NR_ACTIVE_ANON), 2070 global_page_state(NR_ACTIVE_FILE), 2071 global_page_state(NR_INACTIVE_ANON), 2072 global_page_state(NR_INACTIVE_FILE), 2073#ifdef CONFIG_UNEVICTABLE_LRU 2074 global_page_state(NR_UNEVICTABLE), 2075#endif 2076 global_page_state(NR_FILE_DIRTY), 2077 global_page_state(NR_WRITEBACK), 2078 global_page_state(NR_UNSTABLE_NFS), 2079 global_page_state(NR_FREE_PAGES), 2080 global_page_state(NR_SLAB_RECLAIMABLE) + 2081 global_page_state(NR_SLAB_UNRECLAIMABLE), 2082 global_page_state(NR_FILE_MAPPED), 2083 global_page_state(NR_PAGETABLE), 2084 global_page_state(NR_BOUNCE)); 2085 2086 for_each_populated_zone(zone) { 2087 int i; 2088 2089 show_node(zone); 2090 printk("%s" 2091 " free:%lukB" 2092 " min:%lukB" 2093 " low:%lukB" 2094 " high:%lukB" 2095 " active_anon:%lukB" 2096 " inactive_anon:%lukB" 2097 " active_file:%lukB" 2098 " inactive_file:%lukB" 2099#ifdef CONFIG_UNEVICTABLE_LRU 2100 " unevictable:%lukB" 2101#endif 2102 " present:%lukB" 2103 " pages_scanned:%lu" 2104 " all_unreclaimable? %s" 2105 "\n", 2106 zone->name, 2107 K(zone_page_state(zone, NR_FREE_PAGES)), 2108 K(min_wmark_pages(zone)), 2109 K(low_wmark_pages(zone)), 2110 K(high_wmark_pages(zone)), 2111 K(zone_page_state(zone, NR_ACTIVE_ANON)), 2112 K(zone_page_state(zone, NR_INACTIVE_ANON)), 2113 K(zone_page_state(zone, NR_ACTIVE_FILE)), 2114 K(zone_page_state(zone, NR_INACTIVE_FILE)), 2115#ifdef CONFIG_UNEVICTABLE_LRU 2116 K(zone_page_state(zone, NR_UNEVICTABLE)), 2117#endif 2118 K(zone->present_pages), 2119 zone->pages_scanned, 2120 (zone_is_all_unreclaimable(zone) ? "yes" : "no") 2121 ); 2122 printk("lowmem_reserve[]:"); 2123 for (i = 0; i < MAX_NR_ZONES; i++) 2124 printk(" %lu", zone->lowmem_reserve[i]); 2125 printk("\n"); 2126 } 2127 2128 for_each_populated_zone(zone) { 2129 unsigned long nr[MAX_ORDER], flags, order, total = 0; 2130 2131 show_node(zone); 2132 printk("%s: ", zone->name); 2133 2134 spin_lock_irqsave(&zone->lock, flags); 2135 for (order = 0; order < MAX_ORDER; order++) { 2136 nr[order] = zone->free_area[order].nr_free; 2137 total += nr[order] << order; 2138 } 2139 spin_unlock_irqrestore(&zone->lock, flags); 2140 for (order = 0; order < MAX_ORDER; order++) 2141 printk("%lu*%lukB ", nr[order], K(1UL) << order); 2142 printk("= %lukB\n", K(total)); 2143 } 2144 2145 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES)); 2146 2147 show_swap_cache_info(); 2148} 2149 2150static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) 2151{ 2152 zoneref->zone = zone; 2153 zoneref->zone_idx = zone_idx(zone); 2154} 2155 2156/* 2157 * Builds allocation fallback zone lists. 2158 * 2159 * Add all populated zones of a node to the zonelist. 2160 */ 2161static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, 2162 int nr_zones, enum zone_type zone_type) 2163{ 2164 struct zone *zone; 2165 2166 BUG_ON(zone_type >= MAX_NR_ZONES); 2167 zone_type++; 2168 2169 do { 2170 zone_type--; 2171 zone = pgdat->node_zones + zone_type; 2172 if (populated_zone(zone)) { 2173 zoneref_set_zone(zone, 2174 &zonelist->_zonerefs[nr_zones++]); 2175 check_highest_zone(zone_type); 2176 } 2177 2178 } while (zone_type); 2179 return nr_zones; 2180} 2181 2182 2183/* 2184 * zonelist_order: 2185 * 0 = automatic detection of better ordering. 2186 * 1 = order by ([node] distance, -zonetype) 2187 * 2 = order by (-zonetype, [node] distance) 2188 * 2189 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create 2190 * the same zonelist. So only NUMA can configure this param. 2191 */ 2192#define ZONELIST_ORDER_DEFAULT 0 2193#define ZONELIST_ORDER_NODE 1 2194#define ZONELIST_ORDER_ZONE 2 2195 2196/* zonelist order in the kernel. 2197 * set_zonelist_order() will set this to NODE or ZONE. 2198 */ 2199static int current_zonelist_order = ZONELIST_ORDER_DEFAULT; 2200static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"}; 2201 2202 2203#ifdef CONFIG_NUMA 2204/* The value user specified ....changed by config */ 2205static int user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2206/* string for sysctl */ 2207#define NUMA_ZONELIST_ORDER_LEN 16 2208char numa_zonelist_order[16] = "default"; 2209 2210/* 2211 * interface for configure zonelist ordering. 2212 * command line option "numa_zonelist_order" 2213 * = "[dD]efault - default, automatic configuration. 2214 * = "[nN]ode - order by node locality, then by zone within node 2215 * = "[zZ]one - order by zone, then by locality within zone 2216 */ 2217 2218static int __parse_numa_zonelist_order(char *s) 2219{ 2220 if (*s == 'd' || *s == 'D') { 2221 user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2222 } else if (*s == 'n' || *s == 'N') { 2223 user_zonelist_order = ZONELIST_ORDER_NODE; 2224 } else if (*s == 'z' || *s == 'Z') { 2225 user_zonelist_order = ZONELIST_ORDER_ZONE; 2226 } else { 2227 printk(KERN_WARNING 2228 "Ignoring invalid numa_zonelist_order value: " 2229 "%s\n", s); 2230 return -EINVAL; 2231 } 2232 return 0; 2233} 2234 2235static __init int setup_numa_zonelist_order(char *s) 2236{ 2237 if (s) 2238 return __parse_numa_zonelist_order(s); 2239 return 0; 2240} 2241early_param("numa_zonelist_order", setup_numa_zonelist_order); 2242 2243/* 2244 * sysctl handler for numa_zonelist_order 2245 */ 2246int numa_zonelist_order_handler(ctl_table *table, int write, 2247 struct file *file, void __user *buffer, size_t *length, 2248 loff_t *ppos) 2249{ 2250 char saved_string[NUMA_ZONELIST_ORDER_LEN]; 2251 int ret; 2252 2253 if (write) 2254 strncpy(saved_string, (char*)table->data, 2255 NUMA_ZONELIST_ORDER_LEN); 2256 ret = proc_dostring(table, write, file, buffer, length, ppos); 2257 if (ret) 2258 return ret; 2259 if (write) { 2260 int oldval = user_zonelist_order; 2261 if (__parse_numa_zonelist_order((char*)table->data)) { 2262 /* 2263 * bogus value. restore saved string 2264 */ 2265 strncpy((char*)table->data, saved_string, 2266 NUMA_ZONELIST_ORDER_LEN); 2267 user_zonelist_order = oldval; 2268 } else if (oldval != user_zonelist_order) 2269 build_all_zonelists(); 2270 } 2271 return 0; 2272} 2273 2274 2275#define MAX_NODE_LOAD (nr_online_nodes) 2276static int node_load[MAX_NUMNODES]; 2277 2278/** 2279 * find_next_best_node - find the next node that should appear in a given node's fallback list 2280 * @node: node whose fallback list we're appending 2281 * @used_node_mask: nodemask_t of already used nodes 2282 * 2283 * We use a number of factors to determine which is the next node that should 2284 * appear on a given node's fallback list. The node should not have appeared 2285 * already in @node's fallback list, and it should be the next closest node 2286 * according to the distance array (which contains arbitrary distance values 2287 * from each node to each node in the system), and should also prefer nodes 2288 * with no CPUs, since presumably they'll have very little allocation pressure 2289 * on them otherwise. 2290 * It returns -1 if no node is found. 2291 */ 2292static int find_next_best_node(int node, nodemask_t *used_node_mask) 2293{ 2294 int n, val; 2295 int min_val = INT_MAX; 2296 int best_node = -1; 2297 const struct cpumask *tmp = cpumask_of_node(0); 2298 2299 /* Use the local node if we haven't already */ 2300 if (!node_isset(node, *used_node_mask)) { 2301 node_set(node, *used_node_mask); 2302 return node; 2303 } 2304 2305 for_each_node_state(n, N_HIGH_MEMORY) { 2306 2307 /* Don't want a node to appear more than once */ 2308 if (node_isset(n, *used_node_mask)) 2309 continue; 2310 2311 /* Use the distance array to find the distance */ 2312 val = node_distance(node, n); 2313 2314 /* Penalize nodes under us ("prefer the next node") */ 2315 val += (n < node); 2316 2317 /* Give preference to headless and unused nodes */ 2318 tmp = cpumask_of_node(n); 2319 if (!cpumask_empty(tmp)) 2320 val += PENALTY_FOR_NODE_WITH_CPUS; 2321 2322 /* Slight preference for less loaded node */ 2323 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 2324 val += node_load[n]; 2325 2326 if (val < min_val) { 2327 min_val = val; 2328 best_node = n; 2329 } 2330 } 2331 2332 if (best_node >= 0) 2333 node_set(best_node, *used_node_mask); 2334 2335 return best_node; 2336} 2337 2338 2339/* 2340 * Build zonelists ordered by node and zones within node. 2341 * This results in maximum locality--normal zone overflows into local 2342 * DMA zone, if any--but risks exhausting DMA zone. 2343 */ 2344static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) 2345{ 2346 int j; 2347 struct zonelist *zonelist; 2348 2349 zonelist = &pgdat->node_zonelists[0]; 2350 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++) 2351 ; 2352 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2353 MAX_NR_ZONES - 1); 2354 zonelist->_zonerefs[j].zone = NULL; 2355 zonelist->_zonerefs[j].zone_idx = 0; 2356} 2357 2358/* 2359 * Build gfp_thisnode zonelists 2360 */ 2361static void build_thisnode_zonelists(pg_data_t *pgdat) 2362{ 2363 int j; 2364 struct zonelist *zonelist; 2365 2366 zonelist = &pgdat->node_zonelists[1]; 2367 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2368 zonelist->_zonerefs[j].zone = NULL; 2369 zonelist->_zonerefs[j].zone_idx = 0; 2370} 2371 2372/* 2373 * Build zonelists ordered by zone and nodes within zones. 2374 * This results in conserving DMA zone[s] until all Normal memory is 2375 * exhausted, but results in overflowing to remote node while memory 2376 * may still exist in local DMA zone. 2377 */ 2378static int node_order[MAX_NUMNODES]; 2379 2380static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) 2381{ 2382 int pos, j, node; 2383 int zone_type; /* needs to be signed */ 2384 struct zone *z; 2385 struct zonelist *zonelist; 2386 2387 zonelist = &pgdat->node_zonelists[0]; 2388 pos = 0; 2389 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) { 2390 for (j = 0; j < nr_nodes; j++) { 2391 node = node_order[j]; 2392 z = &NODE_DATA(node)->node_zones[zone_type]; 2393 if (populated_zone(z)) { 2394 zoneref_set_zone(z, 2395 &zonelist->_zonerefs[pos++]); 2396 check_highest_zone(zone_type); 2397 } 2398 } 2399 } 2400 zonelist->_zonerefs[pos].zone = NULL; 2401 zonelist->_zonerefs[pos].zone_idx = 0; 2402} 2403 2404static int default_zonelist_order(void) 2405{ 2406 int nid, zone_type; 2407 unsigned long low_kmem_size,total_size; 2408 struct zone *z; 2409 int average_size; 2410 /* 2411 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem. 2412 * If they are really small and used heavily, the system can fall 2413 * into OOM very easily. 2414 * This function detect ZONE_DMA/DMA32 size and confgigures zone order. 2415 */ 2416 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */ 2417 low_kmem_size = 0; 2418 total_size = 0; 2419 for_each_online_node(nid) { 2420 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2421 z = &NODE_DATA(nid)->node_zones[zone_type]; 2422 if (populated_zone(z)) { 2423 if (zone_type < ZONE_NORMAL) 2424 low_kmem_size += z->present_pages; 2425 total_size += z->present_pages; 2426 } 2427 } 2428 } 2429 if (!low_kmem_size || /* there are no DMA area. */ 2430 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */ 2431 return ZONELIST_ORDER_NODE; 2432 /* 2433 * look into each node's config. 2434 * If there is a node whose DMA/DMA32 memory is very big area on 2435 * local memory, NODE_ORDER may be suitable. 2436 */ 2437 average_size = total_size / 2438 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1); 2439 for_each_online_node(nid) { 2440 low_kmem_size = 0; 2441 total_size = 0; 2442 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2443 z = &NODE_DATA(nid)->node_zones[zone_type]; 2444 if (populated_zone(z)) { 2445 if (zone_type < ZONE_NORMAL) 2446 low_kmem_size += z->present_pages; 2447 total_size += z->present_pages; 2448 } 2449 } 2450 if (low_kmem_size && 2451 total_size > average_size && /* ignore small node */ 2452 low_kmem_size > total_size * 70/100) 2453 return ZONELIST_ORDER_NODE; 2454 } 2455 return ZONELIST_ORDER_ZONE; 2456} 2457 2458static void set_zonelist_order(void) 2459{ 2460 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT) 2461 current_zonelist_order = default_zonelist_order(); 2462 else 2463 current_zonelist_order = user_zonelist_order; 2464} 2465 2466static void build_zonelists(pg_data_t *pgdat) 2467{ 2468 int j, node, load; 2469 enum zone_type i; 2470 nodemask_t used_mask; 2471 int local_node, prev_node; 2472 struct zonelist *zonelist; 2473 int order = current_zonelist_order; 2474 2475 /* initialize zonelists */ 2476 for (i = 0; i < MAX_ZONELISTS; i++) { 2477 zonelist = pgdat->node_zonelists + i; 2478 zonelist->_zonerefs[0].zone = NULL; 2479 zonelist->_zonerefs[0].zone_idx = 0; 2480 } 2481 2482 /* NUMA-aware ordering of nodes */ 2483 local_node = pgdat->node_id; 2484 load = nr_online_nodes; 2485 prev_node = local_node; 2486 nodes_clear(used_mask); 2487 2488 memset(node_load, 0, sizeof(node_load)); 2489 memset(node_order, 0, sizeof(node_order)); 2490 j = 0; 2491 2492 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 2493 int distance = node_distance(local_node, node); 2494 2495 /* 2496 * If another node is sufficiently far away then it is better 2497 * to reclaim pages in a zone before going off node. 2498 */ 2499 if (distance > RECLAIM_DISTANCE) 2500 zone_reclaim_mode = 1; 2501 2502 /* 2503 * We don't want to pressure a particular node. 2504 * So adding penalty to the first node in same 2505 * distance group to make it round-robin. 2506 */ 2507 if (distance != node_distance(local_node, prev_node)) 2508 node_load[node] = load; 2509 2510 prev_node = node; 2511 load--; 2512 if (order == ZONELIST_ORDER_NODE) 2513 build_zonelists_in_node_order(pgdat, node); 2514 else 2515 node_order[j++] = node; /* remember order */ 2516 } 2517 2518 if (order == ZONELIST_ORDER_ZONE) { 2519 /* calculate node order -- i.e., DMA last! */ 2520 build_zonelists_in_zone_order(pgdat, j); 2521 } 2522 2523 build_thisnode_zonelists(pgdat); 2524} 2525 2526/* Construct the zonelist performance cache - see further mmzone.h */ 2527static void build_zonelist_cache(pg_data_t *pgdat) 2528{ 2529 struct zonelist *zonelist; 2530 struct zonelist_cache *zlc; 2531 struct zoneref *z; 2532 2533 zonelist = &pgdat->node_zonelists[0]; 2534 zonelist->zlcache_ptr = zlc = &zonelist->zlcache; 2535 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 2536 for (z = zonelist->_zonerefs; z->zone; z++) 2537 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z); 2538} 2539 2540 2541#else /* CONFIG_NUMA */ 2542 2543static void set_zonelist_order(void) 2544{ 2545 current_zonelist_order = ZONELIST_ORDER_ZONE; 2546} 2547 2548static void build_zonelists(pg_data_t *pgdat) 2549{ 2550 int node, local_node; 2551 enum zone_type j; 2552 struct zonelist *zonelist; 2553 2554 local_node = pgdat->node_id; 2555 2556 zonelist = &pgdat->node_zonelists[0]; 2557 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2558 2559 /* 2560 * Now we build the zonelist so that it contains the zones 2561 * of all the other nodes. 2562 * We don't want to pressure a particular node, so when 2563 * building the zones for node N, we make sure that the 2564 * zones coming right after the local ones are those from 2565 * node N+1 (modulo N) 2566 */ 2567 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 2568 if (!node_online(node)) 2569 continue; 2570 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2571 MAX_NR_ZONES - 1); 2572 } 2573 for (node = 0; node < local_node; node++) { 2574 if (!node_online(node)) 2575 continue; 2576 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2577 MAX_NR_ZONES - 1); 2578 } 2579 2580 zonelist->_zonerefs[j].zone = NULL; 2581 zonelist->_zonerefs[j].zone_idx = 0; 2582} 2583 2584/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ 2585static void build_zonelist_cache(pg_data_t *pgdat) 2586{ 2587 pgdat->node_zonelists[0].zlcache_ptr = NULL; 2588} 2589 2590#endif /* CONFIG_NUMA */ 2591 2592/* return values int ....just for stop_machine() */ 2593static int __build_all_zonelists(void *dummy) 2594{ 2595 int nid; 2596 2597 for_each_online_node(nid) { 2598 pg_data_t *pgdat = NODE_DATA(nid); 2599 2600 build_zonelists(pgdat); 2601 build_zonelist_cache(pgdat); 2602 } 2603 return 0; 2604} 2605 2606void build_all_zonelists(void) 2607{ 2608 set_zonelist_order(); 2609 2610 if (system_state == SYSTEM_BOOTING) { 2611 __build_all_zonelists(NULL); 2612 mminit_verify_zonelist(); 2613 cpuset_init_current_mems_allowed(); 2614 } else { 2615 /* we have to stop all cpus to guarantee there is no user 2616 of zonelist */ 2617 stop_machine(__build_all_zonelists, NULL, NULL); 2618 /* cpuset refresh routine should be here */ 2619 } 2620 vm_total_pages = nr_free_pagecache_pages(); 2621 /* 2622 * Disable grouping by mobility if the number of pages in the 2623 * system is too low to allow the mechanism to work. It would be 2624 * more accurate, but expensive to check per-zone. This check is 2625 * made on memory-hotadd so a system can start with mobility 2626 * disabled and enable it later 2627 */ 2628 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) 2629 page_group_by_mobility_disabled = 1; 2630 else 2631 page_group_by_mobility_disabled = 0; 2632 2633 printk("Built %i zonelists in %s order, mobility grouping %s. " 2634 "Total pages: %ld\n", 2635 nr_online_nodes, 2636 zonelist_order_name[current_zonelist_order], 2637 page_group_by_mobility_disabled ? "off" : "on", 2638 vm_total_pages); 2639#ifdef CONFIG_NUMA 2640 printk("Policy zone: %s\n", zone_names[policy_zone]); 2641#endif 2642} 2643 2644/* 2645 * Helper functions to size the waitqueue hash table. 2646 * Essentially these want to choose hash table sizes sufficiently 2647 * large so that collisions trying to wait on pages are rare. 2648 * But in fact, the number of active page waitqueues on typical 2649 * systems is ridiculously low, less than 200. So this is even 2650 * conservative, even though it seems large. 2651 * 2652 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 2653 * waitqueues, i.e. the size of the waitq table given the number of pages. 2654 */ 2655#define PAGES_PER_WAITQUEUE 256 2656 2657#ifndef CONFIG_MEMORY_HOTPLUG 2658static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2659{ 2660 unsigned long size = 1; 2661 2662 pages /= PAGES_PER_WAITQUEUE; 2663 2664 while (size < pages) 2665 size <<= 1; 2666 2667 /* 2668 * Once we have dozens or even hundreds of threads sleeping 2669 * on IO we've got bigger problems than wait queue collision. 2670 * Limit the size of the wait table to a reasonable size. 2671 */ 2672 size = min(size, 4096UL); 2673 2674 return max(size, 4UL); 2675} 2676#else 2677/* 2678 * A zone's size might be changed by hot-add, so it is not possible to determine 2679 * a suitable size for its wait_table. So we use the maximum size now. 2680 * 2681 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: 2682 * 2683 * i386 (preemption config) : 4096 x 16 = 64Kbyte. 2684 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. 2685 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. 2686 * 2687 * The maximum entries are prepared when a zone's memory is (512K + 256) pages 2688 * or more by the traditional way. (See above). It equals: 2689 * 2690 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. 2691 * ia64(16K page size) : = ( 8G + 4M)byte. 2692 * powerpc (64K page size) : = (32G +16M)byte. 2693 */ 2694static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2695{ 2696 return 4096UL; 2697} 2698#endif 2699 2700/* 2701 * This is an integer logarithm so that shifts can be used later 2702 * to extract the more random high bits from the multiplicative 2703 * hash function before the remainder is taken. 2704 */ 2705static inline unsigned long wait_table_bits(unsigned long size) 2706{ 2707 return ffz(~size); 2708} 2709 2710#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) 2711 2712/* 2713 * Mark a number of pageblocks as MIGRATE_RESERVE. The number 2714 * of blocks reserved is based on min_wmark_pages(zone). The memory within 2715 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes 2716 * higher will lead to a bigger reserve which will get freed as contiguous 2717 * blocks as reclaim kicks in 2718 */ 2719static void setup_zone_migrate_reserve(struct zone *zone) 2720{ 2721 unsigned long start_pfn, pfn, end_pfn; 2722 struct page *page; 2723 unsigned long reserve, block_migratetype; 2724 2725 /* Get the start pfn, end pfn and the number of blocks to reserve */ 2726 start_pfn = zone->zone_start_pfn; 2727 end_pfn = start_pfn + zone->spanned_pages; 2728 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >> 2729 pageblock_order; 2730 2731 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 2732 if (!pfn_valid(pfn)) 2733 continue; 2734 page = pfn_to_page(pfn); 2735 2736 /* Watch out for overlapping nodes */ 2737 if (page_to_nid(page) != zone_to_nid(zone)) 2738 continue; 2739 2740 /* Blocks with reserved pages will never free, skip them. */ 2741 if (PageReserved(page)) 2742 continue; 2743 2744 block_migratetype = get_pageblock_migratetype(page); 2745 2746 /* If this block is reserved, account for it */ 2747 if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) { 2748 reserve--; 2749 continue; 2750 } 2751 2752 /* Suitable for reserving if this block is movable */ 2753 if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) { 2754 set_pageblock_migratetype(page, MIGRATE_RESERVE); 2755 move_freepages_block(zone, page, MIGRATE_RESERVE); 2756 reserve--; 2757 continue; 2758 } 2759 2760 /* 2761 * If the reserve is met and this is a previous reserved block, 2762 * take it back 2763 */ 2764 if (block_migratetype == MIGRATE_RESERVE) { 2765 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 2766 move_freepages_block(zone, page, MIGRATE_MOVABLE); 2767 } 2768 } 2769} 2770 2771/* 2772 * Initially all pages are reserved - free ones are freed 2773 * up by free_all_bootmem() once the early boot process is 2774 * done. Non-atomic initialization, single-pass. 2775 */ 2776void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 2777 unsigned long start_pfn, enum memmap_context context) 2778{ 2779 struct page *page; 2780 unsigned long end_pfn = start_pfn + size; 2781 unsigned long pfn; 2782 struct zone *z; 2783 2784 if (highest_memmap_pfn < end_pfn - 1) 2785 highest_memmap_pfn = end_pfn - 1; 2786 2787 z = &NODE_DATA(nid)->node_zones[zone]; 2788 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 2789 /* 2790 * There can be holes in boot-time mem_map[]s 2791 * handed to this function. They do not 2792 * exist on hotplugged memory. 2793 */ 2794 if (context == MEMMAP_EARLY) { 2795 if (!early_pfn_valid(pfn)) 2796 continue; 2797 if (!early_pfn_in_nid(pfn, nid)) 2798 continue; 2799 } 2800 page = pfn_to_page(pfn); 2801 set_page_links(page, zone, nid, pfn); 2802 mminit_verify_page_links(page, zone, nid, pfn); 2803 init_page_count(page); 2804 reset_page_mapcount(page); 2805 SetPageReserved(page); 2806 /* 2807 * Mark the block movable so that blocks are reserved for 2808 * movable at startup. This will force kernel allocations 2809 * to reserve their blocks rather than leaking throughout 2810 * the address space during boot when many long-lived 2811 * kernel allocations are made. Later some blocks near 2812 * the start are marked MIGRATE_RESERVE by 2813 * setup_zone_migrate_reserve() 2814 * 2815 * bitmap is created for zone's valid pfn range. but memmap 2816 * can be created for invalid pages (for alignment) 2817 * check here not to call set_pageblock_migratetype() against 2818 * pfn out of zone. 2819 */ 2820 if ((z->zone_start_pfn <= pfn) 2821 && (pfn < z->zone_start_pfn + z->spanned_pages) 2822 && !(pfn & (pageblock_nr_pages - 1))) 2823 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 2824 2825 INIT_LIST_HEAD(&page->lru); 2826#ifdef WANT_PAGE_VIRTUAL 2827 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 2828 if (!is_highmem_idx(zone)) 2829 set_page_address(page, __va(pfn << PAGE_SHIFT)); 2830#endif 2831 } 2832} 2833 2834static void __meminit zone_init_free_lists(struct zone *zone) 2835{ 2836 int order, t; 2837 for_each_migratetype_order(order, t) { 2838 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); 2839 zone->free_area[order].nr_free = 0; 2840 } 2841} 2842 2843#ifndef __HAVE_ARCH_MEMMAP_INIT 2844#define memmap_init(size, nid, zone, start_pfn) \ 2845 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) 2846#endif 2847 2848static int zone_batchsize(struct zone *zone) 2849{ 2850#ifdef CONFIG_MMU 2851 int batch; 2852 2853 /* 2854 * The per-cpu-pages pools are set to around 1000th of the 2855 * size of the zone. But no more than 1/2 of a meg. 2856 * 2857 * OK, so we don't know how big the cache is. So guess. 2858 */ 2859 batch = zone->present_pages / 1024; 2860 if (batch * PAGE_SIZE > 512 * 1024) 2861 batch = (512 * 1024) / PAGE_SIZE; 2862 batch /= 4; /* We effectively *= 4 below */ 2863 if (batch < 1) 2864 batch = 1; 2865 2866 /* 2867 * Clamp the batch to a 2^n - 1 value. Having a power 2868 * of 2 value was found to be more likely to have 2869 * suboptimal cache aliasing properties in some cases. 2870 * 2871 * For example if 2 tasks are alternately allocating 2872 * batches of pages, one task can end up with a lot 2873 * of pages of one half of the possible page colors 2874 * and the other with pages of the other colors. 2875 */ 2876 batch = rounddown_pow_of_two(batch + batch/2) - 1; 2877 2878 return batch; 2879 2880#else 2881 /* The deferral and batching of frees should be suppressed under NOMMU 2882 * conditions. 2883 * 2884 * The problem is that NOMMU needs to be able to allocate large chunks 2885 * of contiguous memory as there's no hardware page translation to 2886 * assemble apparent contiguous memory from discontiguous pages. 2887 * 2888 * Queueing large contiguous runs of pages for batching, however, 2889 * causes the pages to actually be freed in smaller chunks. As there 2890 * can be a significant delay between the individual batches being 2891 * recycled, this leads to the once large chunks of space being 2892 * fragmented and becoming unavailable for high-order allocations. 2893 */ 2894 return 0; 2895#endif 2896} 2897 2898static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 2899{ 2900 struct per_cpu_pages *pcp; 2901 2902 memset(p, 0, sizeof(*p)); 2903 2904 pcp = &p->pcp; 2905 pcp->count = 0; 2906 pcp->high = 6 * batch; 2907 pcp->batch = max(1UL, 1 * batch); 2908 INIT_LIST_HEAD(&pcp->list); 2909} 2910 2911/* 2912 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist 2913 * to the value high for the pageset p. 2914 */ 2915 2916static void setup_pagelist_highmark(struct per_cpu_pageset *p, 2917 unsigned long high) 2918{ 2919 struct per_cpu_pages *pcp; 2920 2921 pcp = &p->pcp; 2922 pcp->high = high; 2923 pcp->batch = max(1UL, high/4); 2924 if ((high/4) > (PAGE_SHIFT * 8)) 2925 pcp->batch = PAGE_SHIFT * 8; 2926} 2927 2928 2929#ifdef CONFIG_NUMA 2930/* 2931 * Boot pageset table. One per cpu which is going to be used for all 2932 * zones and all nodes. The parameters will be set in such a way 2933 * that an item put on a list will immediately be handed over to 2934 * the buddy list. This is safe since pageset manipulation is done 2935 * with interrupts disabled. 2936 * 2937 * Some NUMA counter updates may also be caught by the boot pagesets. 2938 * 2939 * The boot_pagesets must be kept even after bootup is complete for 2940 * unused processors and/or zones. They do play a role for bootstrapping 2941 * hotplugged processors. 2942 * 2943 * zoneinfo_show() and maybe other functions do 2944 * not check if the processor is online before following the pageset pointer. 2945 * Other parts of the kernel may not check if the zone is available. 2946 */ 2947static struct per_cpu_pageset boot_pageset[NR_CPUS]; 2948 2949/* 2950 * Dynamically allocate memory for the 2951 * per cpu pageset array in struct zone. 2952 */ 2953static int __cpuinit process_zones(int cpu) 2954{ 2955 struct zone *zone, *dzone; 2956 int node = cpu_to_node(cpu); 2957 2958 node_set_state(node, N_CPU); /* this node has a cpu */ 2959 2960 for_each_populated_zone(zone) { 2961 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset), 2962 GFP_KERNEL, node); 2963 if (!zone_pcp(zone, cpu)) 2964 goto bad; 2965 2966 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone)); 2967 2968 if (percpu_pagelist_fraction) 2969 setup_pagelist_highmark(zone_pcp(zone, cpu), 2970 (zone->present_pages / percpu_pagelist_fraction)); 2971 } 2972 2973 return 0; 2974bad: 2975 for_each_zone(dzone) { 2976 if (!populated_zone(dzone)) 2977 continue; 2978 if (dzone == zone) 2979 break; 2980 kfree(zone_pcp(dzone, cpu)); 2981 zone_pcp(dzone, cpu) = NULL; 2982 } 2983 return -ENOMEM; 2984} 2985 2986static inline void free_zone_pagesets(int cpu) 2987{ 2988 struct zone *zone; 2989 2990 for_each_zone(zone) { 2991 struct per_cpu_pageset *pset = zone_pcp(zone, cpu); 2992 2993 /* Free per_cpu_pageset if it is slab allocated */ 2994 if (pset != &boot_pageset[cpu]) 2995 kfree(pset); 2996 zone_pcp(zone, cpu) = NULL; 2997 } 2998} 2999 3000static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb, 3001 unsigned long action, 3002 void *hcpu) 3003{ 3004 int cpu = (long)hcpu; 3005 int ret = NOTIFY_OK; 3006 3007 switch (action) { 3008 case CPU_UP_PREPARE: 3009 case CPU_UP_PREPARE_FROZEN: 3010 if (process_zones(cpu)) 3011 ret = NOTIFY_BAD; 3012 break; 3013 case CPU_UP_CANCELED: 3014 case CPU_UP_CANCELED_FROZEN: 3015 case CPU_DEAD: 3016 case CPU_DEAD_FROZEN: 3017 free_zone_pagesets(cpu); 3018 break; 3019 default: 3020 break; 3021 } 3022 return ret; 3023} 3024 3025static struct notifier_block __cpuinitdata pageset_notifier = 3026 { &pageset_cpuup_callback, NULL, 0 }; 3027 3028void __init setup_per_cpu_pageset(void) 3029{ 3030 int err; 3031 3032 /* Initialize per_cpu_pageset for cpu 0. 3033 * A cpuup callback will do this for every cpu 3034 * as it comes online 3035 */ 3036 err = process_zones(smp_processor_id()); 3037 BUG_ON(err); 3038 register_cpu_notifier(&pageset_notifier); 3039} 3040 3041#endif 3042 3043static noinline __init_refok 3044int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 3045{ 3046 int i; 3047 struct pglist_data *pgdat = zone->zone_pgdat; 3048 size_t alloc_size; 3049 3050 /* 3051 * The per-page waitqueue mechanism uses hashed waitqueues 3052 * per zone. 3053 */ 3054 zone->wait_table_hash_nr_entries = 3055 wait_table_hash_nr_entries(zone_size_pages); 3056 zone->wait_table_bits = 3057 wait_table_bits(zone->wait_table_hash_nr_entries); 3058 alloc_size = zone->wait_table_hash_nr_entries 3059 * sizeof(wait_queue_head_t); 3060 3061 if (!slab_is_available()) { 3062 zone->wait_table = (wait_queue_head_t *) 3063 alloc_bootmem_node(pgdat, alloc_size); 3064 } else { 3065 /* 3066 * This case means that a zone whose size was 0 gets new memory 3067 * via memory hot-add. 3068 * But it may be the case that a new node was hot-added. In 3069 * this case vmalloc() will not be able to use this new node's 3070 * memory - this wait_table must be initialized to use this new 3071 * node itself as well. 3072 * To use this new node's memory, further consideration will be 3073 * necessary. 3074 */ 3075 zone->wait_table = vmalloc(alloc_size); 3076 } 3077 if (!zone->wait_table) 3078 return -ENOMEM; 3079 3080 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i) 3081 init_waitqueue_head(zone->wait_table + i); 3082 3083 return 0; 3084} 3085 3086static __meminit void zone_pcp_init(struct zone *zone) 3087{ 3088 int cpu; 3089 unsigned long batch = zone_batchsize(zone); 3090 3091 for (cpu = 0; cpu < NR_CPUS; cpu++) { 3092#ifdef CONFIG_NUMA 3093 /* Early boot. Slab allocator not functional yet */ 3094 zone_pcp(zone, cpu) = &boot_pageset[cpu]; 3095 setup_pageset(&boot_pageset[cpu],0); 3096#else 3097 setup_pageset(zone_pcp(zone,cpu), batch); 3098#endif 3099 } 3100 if (zone->present_pages) 3101 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", 3102 zone->name, zone->present_pages, batch); 3103} 3104 3105__meminit int init_currently_empty_zone(struct zone *zone, 3106 unsigned long zone_start_pfn, 3107 unsigned long size, 3108 enum memmap_context context) 3109{ 3110 struct pglist_data *pgdat = zone->zone_pgdat; 3111 int ret; 3112 ret = zone_wait_table_init(zone, size); 3113 if (ret) 3114 return ret; 3115 pgdat->nr_zones = zone_idx(zone) + 1; 3116 3117 zone->zone_start_pfn = zone_start_pfn; 3118 3119 mminit_dprintk(MMINIT_TRACE, "memmap_init", 3120 "Initialising map node %d zone %lu pfns %lu -> %lu\n", 3121 pgdat->node_id, 3122 (unsigned long)zone_idx(zone), 3123 zone_start_pfn, (zone_start_pfn + size)); 3124 3125 zone_init_free_lists(zone); 3126 3127 return 0; 3128} 3129 3130#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3131/* 3132 * Basic iterator support. Return the first range of PFNs for a node 3133 * Note: nid == MAX_NUMNODES returns first region regardless of node 3134 */ 3135static int __meminit first_active_region_index_in_nid(int nid) 3136{ 3137 int i; 3138 3139 for (i = 0; i < nr_nodemap_entries; i++) 3140 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid) 3141 return i; 3142 3143 return -1; 3144} 3145 3146/* 3147 * Basic iterator support. Return the next active range of PFNs for a node 3148 * Note: nid == MAX_NUMNODES returns next region regardless of node 3149 */ 3150static int __meminit next_active_region_index_in_nid(int index, int nid) 3151{ 3152 for (index = index + 1; index < nr_nodemap_entries; index++) 3153 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid) 3154 return index; 3155 3156 return -1; 3157} 3158 3159#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID 3160/* 3161 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. 3162 * Architectures may implement their own version but if add_active_range() 3163 * was used and there are no special requirements, this is a convenient 3164 * alternative 3165 */ 3166int __meminit __early_pfn_to_nid(unsigned long pfn) 3167{ 3168 int i; 3169 3170 for (i = 0; i < nr_nodemap_entries; i++) { 3171 unsigned long start_pfn = early_node_map[i].start_pfn; 3172 unsigned long end_pfn = early_node_map[i].end_pfn; 3173 3174 if (start_pfn <= pfn && pfn < end_pfn) 3175 return early_node_map[i].nid; 3176 } 3177 /* This is a memory hole */ 3178 return -1; 3179} 3180#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ 3181 3182int __meminit early_pfn_to_nid(unsigned long pfn) 3183{ 3184 int nid; 3185 3186 nid = __early_pfn_to_nid(pfn); 3187 if (nid >= 0) 3188 return nid; 3189 /* just returns 0 */ 3190 return 0; 3191} 3192 3193#ifdef CONFIG_NODES_SPAN_OTHER_NODES 3194bool __meminit early_pfn_in_nid(unsigned long pfn, int node) 3195{ 3196 int nid; 3197 3198 nid = __early_pfn_to_nid(pfn); 3199 if (nid >= 0 && nid != node) 3200 return false; 3201 return true; 3202} 3203#endif 3204 3205/* Basic iterator support to walk early_node_map[] */ 3206#define for_each_active_range_index_in_nid(i, nid) \ 3207 for (i = first_active_region_index_in_nid(nid); i != -1; \ 3208 i = next_active_region_index_in_nid(i, nid)) 3209 3210/** 3211 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range 3212 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. 3213 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node 3214 * 3215 * If an architecture guarantees that all ranges registered with 3216 * add_active_ranges() contain no holes and may be freed, this 3217 * this function may be used instead of calling free_bootmem() manually. 3218 */ 3219void __init free_bootmem_with_active_regions(int nid, 3220 unsigned long max_low_pfn) 3221{ 3222 int i; 3223 3224 for_each_active_range_index_in_nid(i, nid) { 3225 unsigned long size_pages = 0; 3226 unsigned long end_pfn = early_node_map[i].end_pfn; 3227 3228 if (early_node_map[i].start_pfn >= max_low_pfn) 3229 continue; 3230 3231 if (end_pfn > max_low_pfn) 3232 end_pfn = max_low_pfn; 3233 3234 size_pages = end_pfn - early_node_map[i].start_pfn; 3235 free_bootmem_node(NODE_DATA(early_node_map[i].nid), 3236 PFN_PHYS(early_node_map[i].start_pfn), 3237 size_pages << PAGE_SHIFT); 3238 } 3239} 3240 3241void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data) 3242{ 3243 int i; 3244 int ret; 3245 3246 for_each_active_range_index_in_nid(i, nid) { 3247 ret = work_fn(early_node_map[i].start_pfn, 3248 early_node_map[i].end_pfn, data); 3249 if (ret) 3250 break; 3251 } 3252} 3253/** 3254 * sparse_memory_present_with_active_regions - Call memory_present for each active range 3255 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. 3256 * 3257 * If an architecture guarantees that all ranges registered with 3258 * add_active_ranges() contain no holes and may be freed, this 3259 * function may be used instead of calling memory_present() manually. 3260 */ 3261void __init sparse_memory_present_with_active_regions(int nid) 3262{ 3263 int i; 3264 3265 for_each_active_range_index_in_nid(i, nid) 3266 memory_present(early_node_map[i].nid, 3267 early_node_map[i].start_pfn, 3268 early_node_map[i].end_pfn); 3269} 3270 3271/** 3272 * get_pfn_range_for_nid - Return the start and end page frames for a node 3273 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. 3274 * @start_pfn: Passed by reference. On return, it will have the node start_pfn. 3275 * @end_pfn: Passed by reference. On return, it will have the node end_pfn. 3276 * 3277 * It returns the start and end page frame of a node based on information 3278 * provided by an arch calling add_active_range(). If called for a node 3279 * with no available memory, a warning is printed and the start and end 3280 * PFNs will be 0. 3281 */ 3282void __meminit get_pfn_range_for_nid(unsigned int nid, 3283 unsigned long *start_pfn, unsigned long *end_pfn) 3284{ 3285 int i; 3286 *start_pfn = -1UL; 3287 *end_pfn = 0; 3288 3289 for_each_active_range_index_in_nid(i, nid) { 3290 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn); 3291 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn); 3292 } 3293 3294 if (*start_pfn == -1UL) 3295 *start_pfn = 0; 3296} 3297 3298/* 3299 * This finds a zone that can be used for ZONE_MOVABLE pages. The 3300 * assumption is made that zones within a node are ordered in monotonic 3301 * increasing memory addresses so that the "highest" populated zone is used 3302 */ 3303static void __init find_usable_zone_for_movable(void) 3304{ 3305 int zone_index; 3306 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { 3307 if (zone_index == ZONE_MOVABLE) 3308 continue; 3309 3310 if (arch_zone_highest_possible_pfn[zone_index] > 3311 arch_zone_lowest_possible_pfn[zone_index]) 3312 break; 3313 } 3314 3315 VM_BUG_ON(zone_index == -1); 3316 movable_zone = zone_index; 3317} 3318 3319/* 3320 * The zone ranges provided by the architecture do not include ZONE_MOVABLE 3321 * because it is sized independant of architecture. Unlike the other zones, 3322 * the starting point for ZONE_MOVABLE is not fixed. It may be different 3323 * in each node depending on the size of each node and how evenly kernelcore 3324 * is distributed. This helper function adjusts the zone ranges 3325 * provided by the architecture for a given node by using the end of the 3326 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that 3327 * zones within a node are in order of monotonic increases memory addresses 3328 */ 3329static void __meminit adjust_zone_range_for_zone_movable(int nid, 3330 unsigned long zone_type, 3331 unsigned long node_start_pfn, 3332 unsigned long node_end_pfn, 3333 unsigned long *zone_start_pfn, 3334 unsigned long *zone_end_pfn) 3335{ 3336 /* Only adjust if ZONE_MOVABLE is on this node */ 3337 if (zone_movable_pfn[nid]) { 3338 /* Size ZONE_MOVABLE */ 3339 if (zone_type == ZONE_MOVABLE) { 3340 *zone_start_pfn = zone_movable_pfn[nid]; 3341 *zone_end_pfn = min(node_end_pfn, 3342 arch_zone_highest_possible_pfn[movable_zone]); 3343 3344 /* Adjust for ZONE_MOVABLE starting within this range */ 3345 } else if (*zone_start_pfn < zone_movable_pfn[nid] && 3346 *zone_end_pfn > zone_movable_pfn[nid]) { 3347 *zone_end_pfn = zone_movable_pfn[nid]; 3348 3349 /* Check if this whole range is within ZONE_MOVABLE */ 3350 } else if (*zone_start_pfn >= zone_movable_pfn[nid]) 3351 *zone_start_pfn = *zone_end_pfn; 3352 } 3353} 3354 3355/* 3356 * Return the number of pages a zone spans in a node, including holes 3357 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() 3358 */ 3359static unsigned long __meminit zone_spanned_pages_in_node(int nid, 3360 unsigned long zone_type, 3361 unsigned long *ignored) 3362{ 3363 unsigned long node_start_pfn, node_end_pfn; 3364 unsigned long zone_start_pfn, zone_end_pfn; 3365 3366 /* Get the start and end of the node and zone */ 3367 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3368 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; 3369 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; 3370 adjust_zone_range_for_zone_movable(nid, zone_type, 3371 node_start_pfn, node_end_pfn, 3372 &zone_start_pfn, &zone_end_pfn); 3373 3374 /* Check that this node has pages within the zone's required range */ 3375 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) 3376 return 0; 3377 3378 /* Move the zone boundaries inside the node if necessary */ 3379 zone_end_pfn = min(zone_end_pfn, node_end_pfn); 3380 zone_start_pfn = max(zone_start_pfn, node_start_pfn); 3381 3382 /* Return the spanned pages */ 3383 return zone_end_pfn - zone_start_pfn; 3384} 3385 3386/* 3387 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, 3388 * then all holes in the requested range will be accounted for. 3389 */ 3390static unsigned long __meminit __absent_pages_in_range(int nid, 3391 unsigned long range_start_pfn, 3392 unsigned long range_end_pfn) 3393{ 3394 int i = 0; 3395 unsigned long prev_end_pfn = 0, hole_pages = 0; 3396 unsigned long start_pfn; 3397 3398 /* Find the end_pfn of the first active range of pfns in the node */ 3399 i = first_active_region_index_in_nid(nid); 3400 if (i == -1) 3401 return 0; 3402 3403 prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 3404 3405 /* Account for ranges before physical memory on this node */ 3406 if (early_node_map[i].start_pfn > range_start_pfn) 3407 hole_pages = prev_end_pfn - range_start_pfn; 3408 3409 /* Find all holes for the zone within the node */ 3410 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) { 3411 3412 /* No need to continue if prev_end_pfn is outside the zone */ 3413 if (prev_end_pfn >= range_end_pfn) 3414 break; 3415 3416 /* Make sure the end of the zone is not within the hole */ 3417 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 3418 prev_end_pfn = max(prev_end_pfn, range_start_pfn); 3419 3420 /* Update the hole size cound and move on */ 3421 if (start_pfn > range_start_pfn) { 3422 BUG_ON(prev_end_pfn > start_pfn); 3423 hole_pages += start_pfn - prev_end_pfn; 3424 } 3425 prev_end_pfn = early_node_map[i].end_pfn; 3426 } 3427 3428 /* Account for ranges past physical memory on this node */ 3429 if (range_end_pfn > prev_end_pfn) 3430 hole_pages += range_end_pfn - 3431 max(range_start_pfn, prev_end_pfn); 3432 3433 return hole_pages; 3434} 3435 3436/** 3437 * absent_pages_in_range - Return number of page frames in holes within a range 3438 * @start_pfn: The start PFN to start searching for holes 3439 * @end_pfn: The end PFN to stop searching for holes 3440 * 3441 * It returns the number of pages frames in memory holes within a range. 3442 */ 3443unsigned long __init absent_pages_in_range(unsigned long start_pfn, 3444 unsigned long end_pfn) 3445{ 3446 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); 3447} 3448 3449/* Return the number of page frames in holes in a zone on a node */ 3450static unsigned long __meminit zone_absent_pages_in_node(int nid, 3451 unsigned long zone_type, 3452 unsigned long *ignored) 3453{ 3454 unsigned long node_start_pfn, node_end_pfn; 3455 unsigned long zone_start_pfn, zone_end_pfn; 3456 3457 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3458 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type], 3459 node_start_pfn); 3460 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type], 3461 node_end_pfn); 3462 3463 adjust_zone_range_for_zone_movable(nid, zone_type, 3464 node_start_pfn, node_end_pfn, 3465 &zone_start_pfn, &zone_end_pfn); 3466 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); 3467} 3468 3469#else 3470static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, 3471 unsigned long zone_type, 3472 unsigned long *zones_size) 3473{ 3474 return zones_size[zone_type]; 3475} 3476 3477static inline unsigned long __meminit zone_absent_pages_in_node(int nid, 3478 unsigned long zone_type, 3479 unsigned long *zholes_size) 3480{ 3481 if (!zholes_size) 3482 return 0; 3483 3484 return zholes_size[zone_type]; 3485} 3486 3487#endif 3488 3489static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, 3490 unsigned long *zones_size, unsigned long *zholes_size) 3491{ 3492 unsigned long realtotalpages, totalpages = 0; 3493 enum zone_type i; 3494 3495 for (i = 0; i < MAX_NR_ZONES; i++) 3496 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i, 3497 zones_size); 3498 pgdat->node_spanned_pages = totalpages; 3499 3500 realtotalpages = totalpages; 3501 for (i = 0; i < MAX_NR_ZONES; i++) 3502 realtotalpages -= 3503 zone_absent_pages_in_node(pgdat->node_id, i, 3504 zholes_size); 3505 pgdat->node_present_pages = realtotalpages; 3506 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, 3507 realtotalpages); 3508} 3509 3510#ifndef CONFIG_SPARSEMEM 3511/* 3512 * Calculate the size of the zone->blockflags rounded to an unsigned long 3513 * Start by making sure zonesize is a multiple of pageblock_order by rounding 3514 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally 3515 * round what is now in bits to nearest long in bits, then return it in 3516 * bytes. 3517 */ 3518static unsigned long __init usemap_size(unsigned long zonesize) 3519{ 3520 unsigned long usemapsize; 3521 3522 usemapsize = roundup(zonesize, pageblock_nr_pages); 3523 usemapsize = usemapsize >> pageblock_order; 3524 usemapsize *= NR_PAGEBLOCK_BITS; 3525 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); 3526 3527 return usemapsize / 8; 3528} 3529 3530static void __init setup_usemap(struct pglist_data *pgdat, 3531 struct zone *zone, unsigned long zonesize) 3532{ 3533 unsigned long usemapsize = usemap_size(zonesize); 3534 zone->pageblock_flags = NULL; 3535 if (usemapsize) 3536 zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize); 3537} 3538#else 3539static void inline setup_usemap(struct pglist_data *pgdat, 3540 struct zone *zone, unsigned long zonesize) {} 3541#endif /* CONFIG_SPARSEMEM */ 3542 3543#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 3544 3545/* Return a sensible default order for the pageblock size. */ 3546static inline int pageblock_default_order(void) 3547{ 3548 if (HPAGE_SHIFT > PAGE_SHIFT) 3549 return HUGETLB_PAGE_ORDER; 3550 3551 return MAX_ORDER-1; 3552} 3553 3554/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ 3555static inline void __init set_pageblock_order(unsigned int order) 3556{ 3557 /* Check that pageblock_nr_pages has not already been setup */ 3558 if (pageblock_order) 3559 return; 3560 3561 /* 3562 * Assume the largest contiguous order of interest is a huge page. 3563 * This value may be variable depending on boot parameters on IA64 3564 */ 3565 pageblock_order = order; 3566} 3567#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 3568 3569/* 3570 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() 3571 * and pageblock_default_order() are unused as pageblock_order is set 3572 * at compile-time. See include/linux/pageblock-flags.h for the values of 3573 * pageblock_order based on the kernel config 3574 */ 3575static inline int pageblock_default_order(unsigned int order) 3576{ 3577 return MAX_ORDER-1; 3578} 3579#define set_pageblock_order(x) do {} while (0) 3580 3581#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 3582 3583/* 3584 * Set up the zone data structures: 3585 * - mark all pages reserved 3586 * - mark all memory queues empty 3587 * - clear the memory bitmaps 3588 */ 3589static void __paginginit free_area_init_core(struct pglist_data *pgdat, 3590 unsigned long *zones_size, unsigned long *zholes_size) 3591{ 3592 enum zone_type j; 3593 int nid = pgdat->node_id; 3594 unsigned long zone_start_pfn = pgdat->node_start_pfn; 3595 int ret; 3596 3597 pgdat_resize_init(pgdat); 3598 pgdat->nr_zones = 0; 3599 init_waitqueue_head(&pgdat->kswapd_wait); 3600 pgdat->kswapd_max_order = 0; 3601 pgdat_page_cgroup_init(pgdat); 3602 3603 for (j = 0; j < MAX_NR_ZONES; j++) { 3604 struct zone *zone = pgdat->node_zones + j; 3605 unsigned long size, realsize, memmap_pages; 3606 enum lru_list l; 3607 3608 size = zone_spanned_pages_in_node(nid, j, zones_size); 3609 realsize = size - zone_absent_pages_in_node(nid, j, 3610 zholes_size); 3611 3612 /* 3613 * Adjust realsize so that it accounts for how much memory 3614 * is used by this zone for memmap. This affects the watermark 3615 * and per-cpu initialisations 3616 */ 3617 memmap_pages = 3618 PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT; 3619 if (realsize >= memmap_pages) { 3620 realsize -= memmap_pages; 3621 if (memmap_pages) 3622 printk(KERN_DEBUG 3623 " %s zone: %lu pages used for memmap\n", 3624 zone_names[j], memmap_pages); 3625 } else 3626 printk(KERN_WARNING 3627 " %s zone: %lu pages exceeds realsize %lu\n", 3628 zone_names[j], memmap_pages, realsize); 3629 3630 /* Account for reserved pages */ 3631 if (j == 0 && realsize > dma_reserve) { 3632 realsize -= dma_reserve; 3633 printk(KERN_DEBUG " %s zone: %lu pages reserved\n", 3634 zone_names[0], dma_reserve); 3635 } 3636 3637 if (!is_highmem_idx(j)) 3638 nr_kernel_pages += realsize; 3639 nr_all_pages += realsize; 3640 3641 zone->spanned_pages = size; 3642 zone->present_pages = realsize; 3643#ifdef CONFIG_NUMA 3644 zone->node = nid; 3645 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio) 3646 / 100; 3647 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100; 3648#endif 3649 zone->name = zone_names[j]; 3650 spin_lock_init(&zone->lock); 3651 spin_lock_init(&zone->lru_lock); 3652 zone_seqlock_init(zone); 3653 zone->zone_pgdat = pgdat; 3654 3655 zone->prev_priority = DEF_PRIORITY; 3656 3657 zone_pcp_init(zone); 3658 for_each_lru(l) { 3659 INIT_LIST_HEAD(&zone->lru[l].list); 3660 zone->lru[l].nr_saved_scan = 0; 3661 } 3662 zone->reclaim_stat.recent_rotated[0] = 0; 3663 zone->reclaim_stat.recent_rotated[1] = 0; 3664 zone->reclaim_stat.recent_scanned[0] = 0; 3665 zone->reclaim_stat.recent_scanned[1] = 0; 3666 zap_zone_vm_stats(zone); 3667 zone->flags = 0; 3668 if (!size) 3669 continue; 3670 3671 set_pageblock_order(pageblock_default_order()); 3672 setup_usemap(pgdat, zone, size); 3673 ret = init_currently_empty_zone(zone, zone_start_pfn, 3674 size, MEMMAP_EARLY); 3675 BUG_ON(ret); 3676 memmap_init(size, nid, j, zone_start_pfn); 3677 zone_start_pfn += size; 3678 } 3679} 3680 3681static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat) 3682{ 3683 /* Skip empty nodes */ 3684 if (!pgdat->node_spanned_pages) 3685 return; 3686 3687#ifdef CONFIG_FLAT_NODE_MEM_MAP 3688 /* ia64 gets its own node_mem_map, before this, without bootmem */ 3689 if (!pgdat->node_mem_map) { 3690 unsigned long size, start, end; 3691 struct page *map; 3692 3693 /* 3694 * The zone's endpoints aren't required to be MAX_ORDER 3695 * aligned but the node_mem_map endpoints must be in order 3696 * for the buddy allocator to function correctly. 3697 */ 3698 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); 3699 end = pgdat->node_start_pfn + pgdat->node_spanned_pages; 3700 end = ALIGN(end, MAX_ORDER_NR_PAGES); 3701 size = (end - start) * sizeof(struct page); 3702 map = alloc_remap(pgdat->node_id, size); 3703 if (!map) 3704 map = alloc_bootmem_node(pgdat, size); 3705 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); 3706 } 3707#ifndef CONFIG_NEED_MULTIPLE_NODES 3708 /* 3709 * With no DISCONTIG, the global mem_map is just set as node 0's 3710 */ 3711 if (pgdat == NODE_DATA(0)) { 3712 mem_map = NODE_DATA(0)->node_mem_map; 3713#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3714 if (page_to_pfn(mem_map) != pgdat->node_start_pfn) 3715 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET); 3716#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 3717 } 3718#endif 3719#endif /* CONFIG_FLAT_NODE_MEM_MAP */ 3720} 3721 3722void __paginginit free_area_init_node(int nid, unsigned long *zones_size, 3723 unsigned long node_start_pfn, unsigned long *zholes_size) 3724{ 3725 pg_data_t *pgdat = NODE_DATA(nid); 3726 3727 pgdat->node_id = nid; 3728 pgdat->node_start_pfn = node_start_pfn; 3729 calculate_node_totalpages(pgdat, zones_size, zholes_size); 3730 3731 alloc_node_mem_map(pgdat); 3732#ifdef CONFIG_FLAT_NODE_MEM_MAP 3733 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n", 3734 nid, (unsigned long)pgdat, 3735 (unsigned long)pgdat->node_mem_map); 3736#endif 3737 3738 free_area_init_core(pgdat, zones_size, zholes_size); 3739} 3740 3741#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 3742 3743#if MAX_NUMNODES > 1 3744/* 3745 * Figure out the number of possible node ids. 3746 */ 3747static void __init setup_nr_node_ids(void) 3748{ 3749 unsigned int node; 3750 unsigned int highest = 0; 3751 3752 for_each_node_mask(node, node_possible_map) 3753 highest = node; 3754 nr_node_ids = highest + 1; 3755} 3756#else 3757static inline void setup_nr_node_ids(void) 3758{ 3759} 3760#endif 3761 3762/** 3763 * add_active_range - Register a range of PFNs backed by physical memory 3764 * @nid: The node ID the range resides on 3765 * @start_pfn: The start PFN of the available physical memory 3766 * @end_pfn: The end PFN of the available physical memory 3767 * 3768 * These ranges are stored in an early_node_map[] and later used by 3769 * free_area_init_nodes() to calculate zone sizes and holes. If the 3770 * range spans a memory hole, it is up to the architecture to ensure 3771 * the memory is not freed by the bootmem allocator. If possible 3772 * the range being registered will be merged with existing ranges. 3773 */ 3774void __init add_active_range(unsigned int nid, unsigned long start_pfn, 3775 unsigned long end_pfn) 3776{ 3777 int i; 3778 3779 mminit_dprintk(MMINIT_TRACE, "memory_register", 3780 "Entering add_active_range(%d, %#lx, %#lx) " 3781 "%d entries of %d used\n", 3782 nid, start_pfn, end_pfn, 3783 nr_nodemap_entries, MAX_ACTIVE_REGIONS); 3784 3785 mminit_validate_memmodel_limits(&start_pfn, &end_pfn); 3786 3787 /* Merge with existing active regions if possible */ 3788 for (i = 0; i < nr_nodemap_entries; i++) { 3789 if (early_node_map[i].nid != nid) 3790 continue; 3791 3792 /* Skip if an existing region covers this new one */ 3793 if (start_pfn >= early_node_map[i].start_pfn && 3794 end_pfn <= early_node_map[i].end_pfn) 3795 return; 3796 3797 /* Merge forward if suitable */ 3798 if (start_pfn <= early_node_map[i].end_pfn && 3799 end_pfn > early_node_map[i].end_pfn) { 3800 early_node_map[i].end_pfn = end_pfn; 3801 return; 3802 } 3803 3804 /* Merge backward if suitable */ 3805 if (start_pfn < early_node_map[i].end_pfn && 3806 end_pfn >= early_node_map[i].start_pfn) { 3807 early_node_map[i].start_pfn = start_pfn; 3808 return; 3809 } 3810 } 3811 3812 /* Check that early_node_map is large enough */ 3813 if (i >= MAX_ACTIVE_REGIONS) { 3814 printk(KERN_CRIT "More than %d memory regions, truncating\n", 3815 MAX_ACTIVE_REGIONS); 3816 return; 3817 } 3818 3819 early_node_map[i].nid = nid; 3820 early_node_map[i].start_pfn = start_pfn; 3821 early_node_map[i].end_pfn = end_pfn; 3822 nr_nodemap_entries = i + 1; 3823} 3824 3825/** 3826 * remove_active_range - Shrink an existing registered range of PFNs 3827 * @nid: The node id the range is on that should be shrunk 3828 * @start_pfn: The new PFN of the range 3829 * @end_pfn: The new PFN of the range 3830 * 3831 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node. 3832 * The map is kept near the end physical page range that has already been 3833 * registered. This function allows an arch to shrink an existing registered 3834 * range. 3835 */ 3836void __init remove_active_range(unsigned int nid, unsigned long start_pfn, 3837 unsigned long end_pfn) 3838{ 3839 int i, j; 3840 int removed = 0; 3841 3842 printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n", 3843 nid, start_pfn, end_pfn); 3844 3845 /* Find the old active region end and shrink */ 3846 for_each_active_range_index_in_nid(i, nid) { 3847 if (early_node_map[i].start_pfn >= start_pfn && 3848 early_node_map[i].end_pfn <= end_pfn) { 3849 /* clear it */ 3850 early_node_map[i].start_pfn = 0; 3851 early_node_map[i].end_pfn = 0; 3852 removed = 1; 3853 continue; 3854 } 3855 if (early_node_map[i].start_pfn < start_pfn && 3856 early_node_map[i].end_pfn > start_pfn) { 3857 unsigned long temp_end_pfn = early_node_map[i].end_pfn; 3858 early_node_map[i].end_pfn = start_pfn; 3859 if (temp_end_pfn > end_pfn) 3860 add_active_range(nid, end_pfn, temp_end_pfn); 3861 continue; 3862 } 3863 if (early_node_map[i].start_pfn >= start_pfn && 3864 early_node_map[i].end_pfn > end_pfn && 3865 early_node_map[i].start_pfn < end_pfn) { 3866 early_node_map[i].start_pfn = end_pfn; 3867 continue; 3868 } 3869 } 3870 3871 if (!removed) 3872 return; 3873 3874 /* remove the blank ones */ 3875 for (i = nr_nodemap_entries - 1; i > 0; i--) { 3876 if (early_node_map[i].nid != nid) 3877 continue; 3878 if (early_node_map[i].end_pfn) 3879 continue; 3880 /* we found it, get rid of it */ 3881 for (j = i; j < nr_nodemap_entries - 1; j++) 3882 memcpy(&early_node_map[j], &early_node_map[j+1], 3883 sizeof(early_node_map[j])); 3884 j = nr_nodemap_entries - 1; 3885 memset(&early_node_map[j], 0, sizeof(early_node_map[j])); 3886 nr_nodemap_entries--; 3887 } 3888} 3889 3890/** 3891 * remove_all_active_ranges - Remove all currently registered regions 3892 * 3893 * During discovery, it may be found that a table like SRAT is invalid 3894 * and an alternative discovery method must be used. This function removes 3895 * all currently registered regions. 3896 */ 3897void __init remove_all_active_ranges(void) 3898{ 3899 memset(early_node_map, 0, sizeof(early_node_map)); 3900 nr_nodemap_entries = 0; 3901} 3902 3903/* Compare two active node_active_regions */ 3904static int __init cmp_node_active_region(const void *a, const void *b) 3905{ 3906 struct node_active_region *arange = (struct node_active_region *)a; 3907 struct node_active_region *brange = (struct node_active_region *)b; 3908 3909 /* Done this way to avoid overflows */ 3910 if (arange->start_pfn > brange->start_pfn) 3911 return 1; 3912 if (arange->start_pfn < brange->start_pfn) 3913 return -1; 3914 3915 return 0; 3916} 3917 3918/* sort the node_map by start_pfn */ 3919static void __init sort_node_map(void) 3920{ 3921 sort(early_node_map, (size_t)nr_nodemap_entries, 3922 sizeof(struct node_active_region), 3923 cmp_node_active_region, NULL); 3924} 3925 3926/* Find the lowest pfn for a node */ 3927static unsigned long __init find_min_pfn_for_node(int nid) 3928{ 3929 int i; 3930 unsigned long min_pfn = ULONG_MAX; 3931 3932 /* Assuming a sorted map, the first range found has the starting pfn */ 3933 for_each_active_range_index_in_nid(i, nid) 3934 min_pfn = min(min_pfn, early_node_map[i].start_pfn); 3935 3936 if (min_pfn == ULONG_MAX) { 3937 printk(KERN_WARNING 3938 "Could not find start_pfn for node %d\n", nid); 3939 return 0; 3940 } 3941 3942 return min_pfn; 3943} 3944 3945/** 3946 * find_min_pfn_with_active_regions - Find the minimum PFN registered 3947 * 3948 * It returns the minimum PFN based on information provided via 3949 * add_active_range(). 3950 */ 3951unsigned long __init find_min_pfn_with_active_regions(void) 3952{ 3953 return find_min_pfn_for_node(MAX_NUMNODES); 3954} 3955 3956/* 3957 * early_calculate_totalpages() 3958 * Sum pages in active regions for movable zone. 3959 * Populate N_HIGH_MEMORY for calculating usable_nodes. 3960 */ 3961static unsigned long __init early_calculate_totalpages(void) 3962{ 3963 int i; 3964 unsigned long totalpages = 0; 3965 3966 for (i = 0; i < nr_nodemap_entries; i++) { 3967 unsigned long pages = early_node_map[i].end_pfn - 3968 early_node_map[i].start_pfn; 3969 totalpages += pages; 3970 if (pages) 3971 node_set_state(early_node_map[i].nid, N_HIGH_MEMORY); 3972 } 3973 return totalpages; 3974} 3975 3976/* 3977 * Find the PFN the Movable zone begins in each node. Kernel memory 3978 * is spread evenly between nodes as long as the nodes have enough 3979 * memory. When they don't, some nodes will have more kernelcore than 3980 * others 3981 */ 3982static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn) 3983{ 3984 int i, nid; 3985 unsigned long usable_startpfn; 3986 unsigned long kernelcore_node, kernelcore_remaining; 3987 unsigned long totalpages = early_calculate_totalpages(); 3988 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]); 3989 3990 /* 3991 * If movablecore was specified, calculate what size of 3992 * kernelcore that corresponds so that memory usable for 3993 * any allocation type is evenly spread. If both kernelcore 3994 * and movablecore are specified, then the value of kernelcore 3995 * will be used for required_kernelcore if it's greater than 3996 * what movablecore would have allowed. 3997 */ 3998 if (required_movablecore) { 3999 unsigned long corepages; 4000 4001 /* 4002 * Round-up so that ZONE_MOVABLE is at least as large as what 4003 * was requested by the user 4004 */ 4005 required_movablecore = 4006 roundup(required_movablecore, MAX_ORDER_NR_PAGES); 4007 corepages = totalpages - required_movablecore; 4008 4009 required_kernelcore = max(required_kernelcore, corepages); 4010 } 4011 4012 /* If kernelcore was not specified, there is no ZONE_MOVABLE */ 4013 if (!required_kernelcore) 4014 return; 4015 4016 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ 4017 find_usable_zone_for_movable(); 4018 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; 4019 4020restart: 4021 /* Spread kernelcore memory as evenly as possible throughout nodes */ 4022 kernelcore_node = required_kernelcore / usable_nodes; 4023 for_each_node_state(nid, N_HIGH_MEMORY) { 4024 /* 4025 * Recalculate kernelcore_node if the division per node 4026 * now exceeds what is necessary to satisfy the requested 4027 * amount of memory for the kernel 4028 */ 4029 if (required_kernelcore < kernelcore_node) 4030 kernelcore_node = required_kernelcore / usable_nodes; 4031 4032 /* 4033 * As the map is walked, we track how much memory is usable 4034 * by the kernel using kernelcore_remaining. When it is 4035 * 0, the rest of the node is usable by ZONE_MOVABLE 4036 */ 4037 kernelcore_remaining = kernelcore_node; 4038 4039 /* Go through each range of PFNs within this node */ 4040 for_each_active_range_index_in_nid(i, nid) { 4041 unsigned long start_pfn, end_pfn; 4042 unsigned long size_pages; 4043 4044 start_pfn = max(early_node_map[i].start_pfn, 4045 zone_movable_pfn[nid]); 4046 end_pfn = early_node_map[i].end_pfn; 4047 if (start_pfn >= end_pfn) 4048 continue; 4049 4050 /* Account for what is only usable for kernelcore */ 4051 if (start_pfn < usable_startpfn) { 4052 unsigned long kernel_pages; 4053 kernel_pages = min(end_pfn, usable_startpfn) 4054 - start_pfn; 4055 4056 kernelcore_remaining -= min(kernel_pages, 4057 kernelcore_remaining); 4058 required_kernelcore -= min(kernel_pages, 4059 required_kernelcore); 4060 4061 /* Continue if range is now fully accounted */ 4062 if (end_pfn <= usable_startpfn) { 4063 4064 /* 4065 * Push zone_movable_pfn to the end so 4066 * that if we have to rebalance 4067 * kernelcore across nodes, we will 4068 * not double account here 4069 */ 4070 zone_movable_pfn[nid] = end_pfn; 4071 continue; 4072 } 4073 start_pfn = usable_startpfn; 4074 } 4075 4076 /* 4077 * The usable PFN range for ZONE_MOVABLE is from 4078 * start_pfn->end_pfn. Calculate size_pages as the 4079 * number of pages used as kernelcore 4080 */ 4081 size_pages = end_pfn - start_pfn; 4082 if (size_pages > kernelcore_remaining) 4083 size_pages = kernelcore_remaining; 4084 zone_movable_pfn[nid] = start_pfn + size_pages; 4085 4086 /* 4087 * Some kernelcore has been met, update counts and 4088 * break if the kernelcore for this node has been 4089 * satisified 4090 */ 4091 required_kernelcore -= min(required_kernelcore, 4092 size_pages); 4093 kernelcore_remaining -= size_pages; 4094 if (!kernelcore_remaining) 4095 break; 4096 } 4097 } 4098 4099 /* 4100 * If there is still required_kernelcore, we do another pass with one 4101 * less node in the count. This will push zone_movable_pfn[nid] further 4102 * along on the nodes that still have memory until kernelcore is 4103 * satisified 4104 */ 4105 usable_nodes--; 4106 if (usable_nodes && required_kernelcore > usable_nodes) 4107 goto restart; 4108 4109 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ 4110 for (nid = 0; nid < MAX_NUMNODES; nid++) 4111 zone_movable_pfn[nid] = 4112 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); 4113} 4114 4115/* Any regular memory on that node ? */ 4116static void check_for_regular_memory(pg_data_t *pgdat) 4117{ 4118#ifdef CONFIG_HIGHMEM 4119 enum zone_type zone_type; 4120 4121 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) { 4122 struct zone *zone = &pgdat->node_zones[zone_type]; 4123 if (zone->present_pages) 4124 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY); 4125 } 4126#endif 4127} 4128 4129/** 4130 * free_area_init_nodes - Initialise all pg_data_t and zone data 4131 * @max_zone_pfn: an array of max PFNs for each zone 4132 * 4133 * This will call free_area_init_node() for each active node in the system. 4134 * Using the page ranges provided by add_active_range(), the size of each 4135 * zone in each node and their holes is calculated. If the maximum PFN 4136 * between two adjacent zones match, it is assumed that the zone is empty. 4137 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed 4138 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone 4139 * starts where the previous one ended. For example, ZONE_DMA32 starts 4140 * at arch_max_dma_pfn. 4141 */ 4142void __init free_area_init_nodes(unsigned long *max_zone_pfn) 4143{ 4144 unsigned long nid; 4145 int i; 4146 4147 /* Sort early_node_map as initialisation assumes it is sorted */ 4148 sort_node_map(); 4149 4150 /* Record where the zone boundaries are */ 4151 memset(arch_zone_lowest_possible_pfn, 0, 4152 sizeof(arch_zone_lowest_possible_pfn)); 4153 memset(arch_zone_highest_possible_pfn, 0, 4154 sizeof(arch_zone_highest_possible_pfn)); 4155 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); 4156 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; 4157 for (i = 1; i < MAX_NR_ZONES; i++) { 4158 if (i == ZONE_MOVABLE) 4159 continue; 4160 arch_zone_lowest_possible_pfn[i] = 4161 arch_zone_highest_possible_pfn[i-1]; 4162 arch_zone_highest_possible_pfn[i] = 4163 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); 4164 } 4165 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0; 4166 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0; 4167 4168 /* Find the PFNs that ZONE_MOVABLE begins at in each node */ 4169 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); 4170 find_zone_movable_pfns_for_nodes(zone_movable_pfn); 4171 4172 /* Print out the zone ranges */ 4173 printk("Zone PFN ranges:\n"); 4174 for (i = 0; i < MAX_NR_ZONES; i++) { 4175 if (i == ZONE_MOVABLE) 4176 continue; 4177 printk(" %-8s %0#10lx -> %0#10lx\n", 4178 zone_names[i], 4179 arch_zone_lowest_possible_pfn[i], 4180 arch_zone_highest_possible_pfn[i]); 4181 } 4182 4183 /* Print out the PFNs ZONE_MOVABLE begins at in each node */ 4184 printk("Movable zone start PFN for each node\n"); 4185 for (i = 0; i < MAX_NUMNODES; i++) { 4186 if (zone_movable_pfn[i]) 4187 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]); 4188 } 4189 4190 /* Print out the early_node_map[] */ 4191 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries); 4192 for (i = 0; i < nr_nodemap_entries; i++) 4193 printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid, 4194 early_node_map[i].start_pfn, 4195 early_node_map[i].end_pfn); 4196 4197 /* Initialise every node */ 4198 mminit_verify_pageflags_layout(); 4199 setup_nr_node_ids(); 4200 for_each_online_node(nid) { 4201 pg_data_t *pgdat = NODE_DATA(nid); 4202 free_area_init_node(nid, NULL, 4203 find_min_pfn_for_node(nid), NULL); 4204 4205 /* Any memory on that node */ 4206 if (pgdat->node_present_pages) 4207 node_set_state(nid, N_HIGH_MEMORY); 4208 check_for_regular_memory(pgdat); 4209 } 4210} 4211 4212static int __init cmdline_parse_core(char *p, unsigned long *core) 4213{ 4214 unsigned long long coremem; 4215 if (!p) 4216 return -EINVAL; 4217 4218 coremem = memparse(p, &p); 4219 *core = coremem >> PAGE_SHIFT; 4220 4221 /* Paranoid check that UL is enough for the coremem value */ 4222 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); 4223 4224 return 0; 4225} 4226 4227/* 4228 * kernelcore=size sets the amount of memory for use for allocations that 4229 * cannot be reclaimed or migrated. 4230 */ 4231static int __init cmdline_parse_kernelcore(char *p) 4232{ 4233 return cmdline_parse_core(p, &required_kernelcore); 4234} 4235 4236/* 4237 * movablecore=size sets the amount of memory for use for allocations that 4238 * can be reclaimed or migrated. 4239 */ 4240static int __init cmdline_parse_movablecore(char *p) 4241{ 4242 return cmdline_parse_core(p, &required_movablecore); 4243} 4244 4245early_param("kernelcore", cmdline_parse_kernelcore); 4246early_param("movablecore", cmdline_parse_movablecore); 4247 4248#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 4249 4250/** 4251 * set_dma_reserve - set the specified number of pages reserved in the first zone 4252 * @new_dma_reserve: The number of pages to mark reserved 4253 * 4254 * The per-cpu batchsize and zone watermarks are determined by present_pages. 4255 * In the DMA zone, a significant percentage may be consumed by kernel image 4256 * and other unfreeable allocations which can skew the watermarks badly. This 4257 * function may optionally be used to account for unfreeable pages in the 4258 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and 4259 * smaller per-cpu batchsize. 4260 */ 4261void __init set_dma_reserve(unsigned long new_dma_reserve) 4262{ 4263 dma_reserve = new_dma_reserve; 4264} 4265 4266#ifndef CONFIG_NEED_MULTIPLE_NODES 4267struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] }; 4268EXPORT_SYMBOL(contig_page_data); 4269#endif 4270 4271void __init free_area_init(unsigned long *zones_size) 4272{ 4273 free_area_init_node(0, zones_size, 4274 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 4275} 4276 4277static int page_alloc_cpu_notify(struct notifier_block *self, 4278 unsigned long action, void *hcpu) 4279{ 4280 int cpu = (unsigned long)hcpu; 4281 4282 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { 4283 drain_pages(cpu); 4284 4285 /* 4286 * Spill the event counters of the dead processor 4287 * into the current processors event counters. 4288 * This artificially elevates the count of the current 4289 * processor. 4290 */ 4291 vm_events_fold_cpu(cpu); 4292 4293 /* 4294 * Zero the differential counters of the dead processor 4295 * so that the vm statistics are consistent. 4296 * 4297 * This is only okay since the processor is dead and cannot 4298 * race with what we are doing. 4299 */ 4300 refresh_cpu_vm_stats(cpu); 4301 } 4302 return NOTIFY_OK; 4303} 4304 4305void __init page_alloc_init(void) 4306{ 4307 hotcpu_notifier(page_alloc_cpu_notify, 0); 4308} 4309 4310/* 4311 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio 4312 * or min_free_kbytes changes. 4313 */ 4314static void calculate_totalreserve_pages(void) 4315{ 4316 struct pglist_data *pgdat; 4317 unsigned long reserve_pages = 0; 4318 enum zone_type i, j; 4319 4320 for_each_online_pgdat(pgdat) { 4321 for (i = 0; i < MAX_NR_ZONES; i++) { 4322 struct zone *zone = pgdat->node_zones + i; 4323 unsigned long max = 0; 4324 4325 /* Find valid and maximum lowmem_reserve in the zone */ 4326 for (j = i; j < MAX_NR_ZONES; j++) { 4327 if (zone->lowmem_reserve[j] > max) 4328 max = zone->lowmem_reserve[j]; 4329 } 4330 4331 /* we treat the high watermark as reserved pages. */ 4332 max += high_wmark_pages(zone); 4333 4334 if (max > zone->present_pages) 4335 max = zone->present_pages; 4336 reserve_pages += max; 4337 } 4338 } 4339 totalreserve_pages = reserve_pages; 4340} 4341 4342/* 4343 * setup_per_zone_lowmem_reserve - called whenever 4344 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 4345 * has a correct pages reserved value, so an adequate number of 4346 * pages are left in the zone after a successful __alloc_pages(). 4347 */ 4348static void setup_per_zone_lowmem_reserve(void) 4349{ 4350 struct pglist_data *pgdat; 4351 enum zone_type j, idx; 4352 4353 for_each_online_pgdat(pgdat) { 4354 for (j = 0; j < MAX_NR_ZONES; j++) { 4355 struct zone *zone = pgdat->node_zones + j; 4356 unsigned long present_pages = zone->present_pages; 4357 4358 zone->lowmem_reserve[j] = 0; 4359 4360 idx = j; 4361 while (idx) { 4362 struct zone *lower_zone; 4363 4364 idx--; 4365 4366 if (sysctl_lowmem_reserve_ratio[idx] < 1) 4367 sysctl_lowmem_reserve_ratio[idx] = 1; 4368 4369 lower_zone = pgdat->node_zones + idx; 4370 lower_zone->lowmem_reserve[j] = present_pages / 4371 sysctl_lowmem_reserve_ratio[idx]; 4372 present_pages += lower_zone->present_pages; 4373 } 4374 } 4375 } 4376 4377 /* update totalreserve_pages */ 4378 calculate_totalreserve_pages(); 4379} 4380 4381/** 4382 * setup_per_zone_pages_min - called when min_free_kbytes changes. 4383 * 4384 * Ensures that the pages_{min,low,high} values for each zone are set correctly 4385 * with respect to min_free_kbytes. 4386 */ 4387void setup_per_zone_pages_min(void) 4388{ 4389 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 4390 unsigned long lowmem_pages = 0; 4391 struct zone *zone; 4392 unsigned long flags; 4393 4394 /* Calculate total number of !ZONE_HIGHMEM pages */ 4395 for_each_zone(zone) { 4396 if (!is_highmem(zone)) 4397 lowmem_pages += zone->present_pages; 4398 } 4399 4400 for_each_zone(zone) { 4401 u64 tmp; 4402 4403 spin_lock_irqsave(&zone->lock, flags); 4404 tmp = (u64)pages_min * zone->present_pages; 4405 do_div(tmp, lowmem_pages); 4406 if (is_highmem(zone)) { 4407 /* 4408 * __GFP_HIGH and PF_MEMALLOC allocations usually don't 4409 * need highmem pages, so cap pages_min to a small 4410 * value here. 4411 * 4412 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN) 4413 * deltas controls asynch page reclaim, and so should 4414 * not be capped for highmem. 4415 */ 4416 int min_pages; 4417 4418 min_pages = zone->present_pages / 1024; 4419 if (min_pages < SWAP_CLUSTER_MAX) 4420 min_pages = SWAP_CLUSTER_MAX; 4421 if (min_pages > 128) 4422 min_pages = 128; 4423 zone->watermark[WMARK_MIN] = min_pages; 4424 } else { 4425 /* 4426 * If it's a lowmem zone, reserve a number of pages 4427 * proportionate to the zone's size. 4428 */ 4429 zone->watermark[WMARK_MIN] = tmp; 4430 } 4431 4432 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2); 4433 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1); 4434 setup_zone_migrate_reserve(zone); 4435 spin_unlock_irqrestore(&zone->lock, flags); 4436 } 4437 4438 /* update totalreserve_pages */ 4439 calculate_totalreserve_pages(); 4440} 4441 4442/** 4443 * setup_per_zone_inactive_ratio - called when min_free_kbytes changes. 4444 * 4445 * The inactive anon list should be small enough that the VM never has to 4446 * do too much work, but large enough that each inactive page has a chance 4447 * to be referenced again before it is swapped out. 4448 * 4449 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to 4450 * INACTIVE_ANON pages on this zone's LRU, maintained by the 4451 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of 4452 * the anonymous pages are kept on the inactive list. 4453 * 4454 * total target max 4455 * memory ratio inactive anon 4456 * ------------------------------------- 4457 * 10MB 1 5MB 4458 * 100MB 1 50MB 4459 * 1GB 3 250MB 4460 * 10GB 10 0.9GB 4461 * 100GB 31 3GB 4462 * 1TB 101 10GB 4463 * 10TB 320 32GB 4464 */ 4465static void setup_per_zone_inactive_ratio(void) 4466{ 4467 struct zone *zone; 4468 4469 for_each_zone(zone) { 4470 unsigned int gb, ratio; 4471 4472 /* Zone size in gigabytes */ 4473 gb = zone->present_pages >> (30 - PAGE_SHIFT); 4474 if (gb) 4475 ratio = int_sqrt(10 * gb); 4476 else 4477 ratio = 1; 4478 4479 zone->inactive_ratio = ratio; 4480 } 4481} 4482 4483/* 4484 * Initialise min_free_kbytes. 4485 * 4486 * For small machines we want it small (128k min). For large machines 4487 * we want it large (64MB max). But it is not linear, because network 4488 * bandwidth does not increase linearly with machine size. We use 4489 * 4490 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 4491 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 4492 * 4493 * which yields 4494 * 4495 * 16MB: 512k 4496 * 32MB: 724k 4497 * 64MB: 1024k 4498 * 128MB: 1448k 4499 * 256MB: 2048k 4500 * 512MB: 2896k 4501 * 1024MB: 4096k 4502 * 2048MB: 5792k 4503 * 4096MB: 8192k 4504 * 8192MB: 11584k 4505 * 16384MB: 16384k 4506 */ 4507static int __init init_per_zone_pages_min(void) 4508{ 4509 unsigned long lowmem_kbytes; 4510 4511 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 4512 4513 min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 4514 if (min_free_kbytes < 128) 4515 min_free_kbytes = 128; 4516 if (min_free_kbytes > 65536) 4517 min_free_kbytes = 65536; 4518 setup_per_zone_pages_min(); 4519 setup_per_zone_lowmem_reserve(); 4520 setup_per_zone_inactive_ratio(); 4521 return 0; 4522} 4523module_init(init_per_zone_pages_min) 4524 4525/* 4526 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 4527 * that we can call two helper functions whenever min_free_kbytes 4528 * changes. 4529 */ 4530int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 4531 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4532{ 4533 proc_dointvec(table, write, file, buffer, length, ppos); 4534 if (write) 4535 setup_per_zone_pages_min(); 4536 return 0; 4537} 4538 4539#ifdef CONFIG_NUMA 4540int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, 4541 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4542{ 4543 struct zone *zone; 4544 int rc; 4545 4546 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4547 if (rc) 4548 return rc; 4549 4550 for_each_zone(zone) 4551 zone->min_unmapped_pages = (zone->present_pages * 4552 sysctl_min_unmapped_ratio) / 100; 4553 return 0; 4554} 4555 4556int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write, 4557 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4558{ 4559 struct zone *zone; 4560 int rc; 4561 4562 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4563 if (rc) 4564 return rc; 4565 4566 for_each_zone(zone) 4567 zone->min_slab_pages = (zone->present_pages * 4568 sysctl_min_slab_ratio) / 100; 4569 return 0; 4570} 4571#endif 4572 4573/* 4574 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 4575 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 4576 * whenever sysctl_lowmem_reserve_ratio changes. 4577 * 4578 * The reserve ratio obviously has absolutely no relation with the 4579 * minimum watermarks. The lowmem reserve ratio can only make sense 4580 * if in function of the boot time zone sizes. 4581 */ 4582int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, 4583 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4584{ 4585 proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4586 setup_per_zone_lowmem_reserve(); 4587 return 0; 4588} 4589 4590/* 4591 * percpu_pagelist_fraction - changes the pcp->high for each zone on each 4592 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist 4593 * can have before it gets flushed back to buddy allocator. 4594 */ 4595 4596int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, 4597 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 4598{ 4599 struct zone *zone; 4600 unsigned int cpu; 4601 int ret; 4602 4603 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 4604 if (!write || (ret == -EINVAL)) 4605 return ret; 4606 for_each_zone(zone) { 4607 for_each_online_cpu(cpu) { 4608 unsigned long high; 4609 high = zone->present_pages / percpu_pagelist_fraction; 4610 setup_pagelist_highmark(zone_pcp(zone, cpu), high); 4611 } 4612 } 4613 return 0; 4614} 4615 4616int hashdist = HASHDIST_DEFAULT; 4617 4618#ifdef CONFIG_NUMA 4619static int __init set_hashdist(char *str) 4620{ 4621 if (!str) 4622 return 0; 4623 hashdist = simple_strtoul(str, &str, 0); 4624 return 1; 4625} 4626__setup("hashdist=", set_hashdist); 4627#endif 4628 4629/* 4630 * allocate a large system hash table from bootmem 4631 * - it is assumed that the hash table must contain an exact power-of-2 4632 * quantity of entries 4633 * - limit is the number of hash buckets, not the total allocation size 4634 */ 4635void *__init alloc_large_system_hash(const char *tablename, 4636 unsigned long bucketsize, 4637 unsigned long numentries, 4638 int scale, 4639 int flags, 4640 unsigned int *_hash_shift, 4641 unsigned int *_hash_mask, 4642 unsigned long limit) 4643{ 4644 unsigned long long max = limit; 4645 unsigned long log2qty, size; 4646 void *table = NULL; 4647 4648 /* allow the kernel cmdline to have a say */ 4649 if (!numentries) { 4650 /* round applicable memory size up to nearest megabyte */ 4651 numentries = nr_kernel_pages; 4652 numentries += (1UL << (20 - PAGE_SHIFT)) - 1; 4653 numentries >>= 20 - PAGE_SHIFT; 4654 numentries <<= 20 - PAGE_SHIFT; 4655 4656 /* limit to 1 bucket per 2^scale bytes of low memory */ 4657 if (scale > PAGE_SHIFT) 4658 numentries >>= (scale - PAGE_SHIFT); 4659 else 4660 numentries <<= (PAGE_SHIFT - scale); 4661 4662 /* Make sure we've got at least a 0-order allocation.. */ 4663 if (unlikely((numentries * bucketsize) < PAGE_SIZE)) 4664 numentries = PAGE_SIZE / bucketsize; 4665 } 4666 numentries = roundup_pow_of_two(numentries); 4667 4668 /* limit allocation size to 1/16 total memory by default */ 4669 if (max == 0) { 4670 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 4671 do_div(max, bucketsize); 4672 } 4673 4674 if (numentries > max) 4675 numentries = max; 4676 4677 log2qty = ilog2(numentries); 4678 4679 do { 4680 size = bucketsize << log2qty; 4681 if (flags & HASH_EARLY) 4682 table = alloc_bootmem_nopanic(size); 4683 else if (hashdist) 4684 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 4685 else { 4686 /* 4687 * If bucketsize is not a power-of-two, we may free 4688 * some pages at the end of hash table which 4689 * alloc_pages_exact() automatically does 4690 */ 4691 if (get_order(size) < MAX_ORDER) 4692 table = alloc_pages_exact(size, GFP_ATOMIC); 4693 } 4694 } while (!table && size > PAGE_SIZE && --log2qty); 4695 4696 if (!table) 4697 panic("Failed to allocate %s hash table\n", tablename); 4698 4699 printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n", 4700 tablename, 4701 (1U << log2qty), 4702 ilog2(size) - PAGE_SHIFT, 4703 size); 4704 4705 if (_hash_shift) 4706 *_hash_shift = log2qty; 4707 if (_hash_mask) 4708 *_hash_mask = (1 << log2qty) - 1; 4709 4710 /* 4711 * If hashdist is set, the table allocation is done with __vmalloc() 4712 * which invokes the kmemleak_alloc() callback. This function may also 4713 * be called before the slab and kmemleak are initialised when 4714 * kmemleak simply buffers the request to be executed later 4715 * (GFP_ATOMIC flag ignored in this case). 4716 */ 4717 if (!hashdist) 4718 kmemleak_alloc(table, size, 1, GFP_ATOMIC); 4719 4720 return table; 4721} 4722 4723/* Return a pointer to the bitmap storing bits affecting a block of pages */ 4724static inline unsigned long *get_pageblock_bitmap(struct zone *zone, 4725 unsigned long pfn) 4726{ 4727#ifdef CONFIG_SPARSEMEM 4728 return __pfn_to_section(pfn)->pageblock_flags; 4729#else 4730 return zone->pageblock_flags; 4731#endif /* CONFIG_SPARSEMEM */ 4732} 4733 4734static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) 4735{ 4736#ifdef CONFIG_SPARSEMEM 4737 pfn &= (PAGES_PER_SECTION-1); 4738 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 4739#else 4740 pfn = pfn - zone->zone_start_pfn; 4741 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 4742#endif /* CONFIG_SPARSEMEM */ 4743} 4744 4745/** 4746 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages 4747 * @page: The page within the block of interest 4748 * @start_bitidx: The first bit of interest to retrieve 4749 * @end_bitidx: The last bit of interest 4750 * returns pageblock_bits flags 4751 */ 4752unsigned long get_pageblock_flags_group(struct page *page, 4753 int start_bitidx, int end_bitidx) 4754{ 4755 struct zone *zone; 4756 unsigned long *bitmap; 4757 unsigned long pfn, bitidx; 4758 unsigned long flags = 0; 4759 unsigned long value = 1; 4760 4761 zone = page_zone(page); 4762 pfn = page_to_pfn(page); 4763 bitmap = get_pageblock_bitmap(zone, pfn); 4764 bitidx = pfn_to_bitidx(zone, pfn); 4765 4766 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 4767 if (test_bit(bitidx + start_bitidx, bitmap)) 4768 flags |= value; 4769 4770 return flags; 4771} 4772 4773/** 4774 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages 4775 * @page: The page within the block of interest 4776 * @start_bitidx: The first bit of interest 4777 * @end_bitidx: The last bit of interest 4778 * @flags: The flags to set 4779 */ 4780void set_pageblock_flags_group(struct page *page, unsigned long flags, 4781 int start_bitidx, int end_bitidx) 4782{ 4783 struct zone *zone; 4784 unsigned long *bitmap; 4785 unsigned long pfn, bitidx; 4786 unsigned long value = 1; 4787 4788 zone = page_zone(page); 4789 pfn = page_to_pfn(page); 4790 bitmap = get_pageblock_bitmap(zone, pfn); 4791 bitidx = pfn_to_bitidx(zone, pfn); 4792 VM_BUG_ON(pfn < zone->zone_start_pfn); 4793 VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages); 4794 4795 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 4796 if (flags & value) 4797 __set_bit(bitidx + start_bitidx, bitmap); 4798 else 4799 __clear_bit(bitidx + start_bitidx, bitmap); 4800} 4801 4802/* 4803 * This is designed as sub function...plz see page_isolation.c also. 4804 * set/clear page block's type to be ISOLATE. 4805 * page allocater never alloc memory from ISOLATE block. 4806 */ 4807 4808int set_migratetype_isolate(struct page *page) 4809{ 4810 struct zone *zone; 4811 unsigned long flags; 4812 int ret = -EBUSY; 4813 4814 zone = page_zone(page); 4815 spin_lock_irqsave(&zone->lock, flags); 4816 /* 4817 * In future, more migrate types will be able to be isolation target. 4818 */ 4819 if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE) 4820 goto out; 4821 set_pageblock_migratetype(page, MIGRATE_ISOLATE); 4822 move_freepages_block(zone, page, MIGRATE_ISOLATE); 4823 ret = 0; 4824out: 4825 spin_unlock_irqrestore(&zone->lock, flags); 4826 if (!ret) 4827 drain_all_pages(); 4828 return ret; 4829} 4830 4831void unset_migratetype_isolate(struct page *page) 4832{ 4833 struct zone *zone; 4834 unsigned long flags; 4835 zone = page_zone(page); 4836 spin_lock_irqsave(&zone->lock, flags); 4837 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE) 4838 goto out; 4839 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 4840 move_freepages_block(zone, page, MIGRATE_MOVABLE); 4841out: 4842 spin_unlock_irqrestore(&zone->lock, flags); 4843} 4844 4845#ifdef CONFIG_MEMORY_HOTREMOVE 4846/* 4847 * All pages in the range must be isolated before calling this. 4848 */ 4849void 4850__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) 4851{ 4852 struct page *page; 4853 struct zone *zone; 4854 int order, i; 4855 unsigned long pfn; 4856 unsigned long flags; 4857 /* find the first valid pfn */ 4858 for (pfn = start_pfn; pfn < end_pfn; pfn++) 4859 if (pfn_valid(pfn)) 4860 break; 4861 if (pfn == end_pfn) 4862 return; 4863 zone = page_zone(pfn_to_page(pfn)); 4864 spin_lock_irqsave(&zone->lock, flags); 4865 pfn = start_pfn; 4866 while (pfn < end_pfn) { 4867 if (!pfn_valid(pfn)) { 4868 pfn++; 4869 continue; 4870 } 4871 page = pfn_to_page(pfn); 4872 BUG_ON(page_count(page)); 4873 BUG_ON(!PageBuddy(page)); 4874 order = page_order(page); 4875#ifdef CONFIG_DEBUG_VM 4876 printk(KERN_INFO "remove from free list %lx %d %lx\n", 4877 pfn, 1 << order, end_pfn); 4878#endif 4879 list_del(&page->lru); 4880 rmv_page_order(page); 4881 zone->free_area[order].nr_free--; 4882 __mod_zone_page_state(zone, NR_FREE_PAGES, 4883 - (1UL << order)); 4884 for (i = 0; i < (1 << order); i++) 4885 SetPageReserved((page+i)); 4886 pfn += (1 << order); 4887 } 4888 spin_unlock_irqrestore(&zone->lock, flags); 4889} 4890#endif 4891