page_alloc.c revision 0e0b864e069c52a7b3e4a7da56e29b03a012fd75
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/bootmem.h> 23#include <linux/compiler.h> 24#include <linux/kernel.h> 25#include <linux/module.h> 26#include <linux/suspend.h> 27#include <linux/pagevec.h> 28#include <linux/blkdev.h> 29#include <linux/slab.h> 30#include <linux/notifier.h> 31#include <linux/topology.h> 32#include <linux/sysctl.h> 33#include <linux/cpu.h> 34#include <linux/cpuset.h> 35#include <linux/memory_hotplug.h> 36#include <linux/nodemask.h> 37#include <linux/vmalloc.h> 38#include <linux/mempolicy.h> 39#include <linux/stop_machine.h> 40#include <linux/sort.h> 41#include <linux/pfn.h> 42 43#include <asm/tlbflush.h> 44#include <asm/div64.h> 45#include "internal.h" 46 47/* 48 * MCD - HACK: Find somewhere to initialize this EARLY, or make this 49 * initializer cleaner 50 */ 51nodemask_t node_online_map __read_mostly = { { [0] = 1UL } }; 52EXPORT_SYMBOL(node_online_map); 53nodemask_t node_possible_map __read_mostly = NODE_MASK_ALL; 54EXPORT_SYMBOL(node_possible_map); 55unsigned long totalram_pages __read_mostly; 56unsigned long totalreserve_pages __read_mostly; 57long nr_swap_pages; 58int percpu_pagelist_fraction; 59 60static void __free_pages_ok(struct page *page, unsigned int order); 61 62/* 63 * results with 256, 32 in the lowmem_reserve sysctl: 64 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) 65 * 1G machine -> (16M dma, 784M normal, 224M high) 66 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA 67 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL 68 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA 69 * 70 * TBD: should special case ZONE_DMA32 machines here - in those we normally 71 * don't need any ZONE_NORMAL reservation 72 */ 73int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 74 256, 75#ifdef CONFIG_ZONE_DMA32 76 256, 77#endif 78#ifdef CONFIG_HIGHMEM 79 32 80#endif 81}; 82 83EXPORT_SYMBOL(totalram_pages); 84 85/* 86 * Used by page_zone() to look up the address of the struct zone whose 87 * id is encoded in the upper bits of page->flags 88 */ 89struct zone *zone_table[1 << ZONETABLE_SHIFT] __read_mostly; 90EXPORT_SYMBOL(zone_table); 91 92static char *zone_names[MAX_NR_ZONES] = { 93 "DMA", 94#ifdef CONFIG_ZONE_DMA32 95 "DMA32", 96#endif 97 "Normal", 98#ifdef CONFIG_HIGHMEM 99 "HighMem" 100#endif 101}; 102 103int min_free_kbytes = 1024; 104 105unsigned long __meminitdata nr_kernel_pages; 106unsigned long __meminitdata nr_all_pages; 107static unsigned long __initdata dma_reserve; 108 109#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 110 /* 111 * MAX_ACTIVE_REGIONS determines the maxmimum number of distinct 112 * ranges of memory (RAM) that may be registered with add_active_range(). 113 * Ranges passed to add_active_range() will be merged if possible 114 * so the number of times add_active_range() can be called is 115 * related to the number of nodes and the number of holes 116 */ 117 #ifdef CONFIG_MAX_ACTIVE_REGIONS 118 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */ 119 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS 120 #else 121 #if MAX_NUMNODES >= 32 122 /* If there can be many nodes, allow up to 50 holes per node */ 123 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50) 124 #else 125 /* By default, allow up to 256 distinct regions */ 126 #define MAX_ACTIVE_REGIONS 256 127 #endif 128 #endif 129 130 struct node_active_region __initdata early_node_map[MAX_ACTIVE_REGIONS]; 131 int __initdata nr_nodemap_entries; 132 unsigned long __initdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; 133 unsigned long __initdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; 134#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 135 136#ifdef CONFIG_DEBUG_VM 137static int page_outside_zone_boundaries(struct zone *zone, struct page *page) 138{ 139 int ret = 0; 140 unsigned seq; 141 unsigned long pfn = page_to_pfn(page); 142 143 do { 144 seq = zone_span_seqbegin(zone); 145 if (pfn >= zone->zone_start_pfn + zone->spanned_pages) 146 ret = 1; 147 else if (pfn < zone->zone_start_pfn) 148 ret = 1; 149 } while (zone_span_seqretry(zone, seq)); 150 151 return ret; 152} 153 154static int page_is_consistent(struct zone *zone, struct page *page) 155{ 156#ifdef CONFIG_HOLES_IN_ZONE 157 if (!pfn_valid(page_to_pfn(page))) 158 return 0; 159#endif 160 if (zone != page_zone(page)) 161 return 0; 162 163 return 1; 164} 165/* 166 * Temporary debugging check for pages not lying within a given zone. 167 */ 168static int bad_range(struct zone *zone, struct page *page) 169{ 170 if (page_outside_zone_boundaries(zone, page)) 171 return 1; 172 if (!page_is_consistent(zone, page)) 173 return 1; 174 175 return 0; 176} 177#else 178static inline int bad_range(struct zone *zone, struct page *page) 179{ 180 return 0; 181} 182#endif 183 184static void bad_page(struct page *page) 185{ 186 printk(KERN_EMERG "Bad page state in process '%s'\n" 187 KERN_EMERG "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n" 188 KERN_EMERG "Trying to fix it up, but a reboot is needed\n" 189 KERN_EMERG "Backtrace:\n", 190 current->comm, page, (int)(2*sizeof(unsigned long)), 191 (unsigned long)page->flags, page->mapping, 192 page_mapcount(page), page_count(page)); 193 dump_stack(); 194 page->flags &= ~(1 << PG_lru | 195 1 << PG_private | 196 1 << PG_locked | 197 1 << PG_active | 198 1 << PG_dirty | 199 1 << PG_reclaim | 200 1 << PG_slab | 201 1 << PG_swapcache | 202 1 << PG_writeback | 203 1 << PG_buddy ); 204 set_page_count(page, 0); 205 reset_page_mapcount(page); 206 page->mapping = NULL; 207 add_taint(TAINT_BAD_PAGE); 208} 209 210/* 211 * Higher-order pages are called "compound pages". They are structured thusly: 212 * 213 * The first PAGE_SIZE page is called the "head page". 214 * 215 * The remaining PAGE_SIZE pages are called "tail pages". 216 * 217 * All pages have PG_compound set. All pages have their ->private pointing at 218 * the head page (even the head page has this). 219 * 220 * The first tail page's ->lru.next holds the address of the compound page's 221 * put_page() function. Its ->lru.prev holds the order of allocation. 222 * This usage means that zero-order pages may not be compound. 223 */ 224 225static void free_compound_page(struct page *page) 226{ 227 __free_pages_ok(page, (unsigned long)page[1].lru.prev); 228} 229 230static void prep_compound_page(struct page *page, unsigned long order) 231{ 232 int i; 233 int nr_pages = 1 << order; 234 235 page[1].lru.next = (void *)free_compound_page; /* set dtor */ 236 page[1].lru.prev = (void *)order; 237 for (i = 0; i < nr_pages; i++) { 238 struct page *p = page + i; 239 240 __SetPageCompound(p); 241 set_page_private(p, (unsigned long)page); 242 } 243} 244 245static void destroy_compound_page(struct page *page, unsigned long order) 246{ 247 int i; 248 int nr_pages = 1 << order; 249 250 if (unlikely((unsigned long)page[1].lru.prev != order)) 251 bad_page(page); 252 253 for (i = 0; i < nr_pages; i++) { 254 struct page *p = page + i; 255 256 if (unlikely(!PageCompound(p) | 257 (page_private(p) != (unsigned long)page))) 258 bad_page(page); 259 __ClearPageCompound(p); 260 } 261} 262 263static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) 264{ 265 int i; 266 267 VM_BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM); 268 /* 269 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO 270 * and __GFP_HIGHMEM from hard or soft interrupt context. 271 */ 272 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); 273 for (i = 0; i < (1 << order); i++) 274 clear_highpage(page + i); 275} 276 277/* 278 * function for dealing with page's order in buddy system. 279 * zone->lock is already acquired when we use these. 280 * So, we don't need atomic page->flags operations here. 281 */ 282static inline unsigned long page_order(struct page *page) 283{ 284 return page_private(page); 285} 286 287static inline void set_page_order(struct page *page, int order) 288{ 289 set_page_private(page, order); 290 __SetPageBuddy(page); 291} 292 293static inline void rmv_page_order(struct page *page) 294{ 295 __ClearPageBuddy(page); 296 set_page_private(page, 0); 297} 298 299/* 300 * Locate the struct page for both the matching buddy in our 301 * pair (buddy1) and the combined O(n+1) page they form (page). 302 * 303 * 1) Any buddy B1 will have an order O twin B2 which satisfies 304 * the following equation: 305 * B2 = B1 ^ (1 << O) 306 * For example, if the starting buddy (buddy2) is #8 its order 307 * 1 buddy is #10: 308 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 309 * 310 * 2) Any buddy B will have an order O+1 parent P which 311 * satisfies the following equation: 312 * P = B & ~(1 << O) 313 * 314 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 315 */ 316static inline struct page * 317__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order) 318{ 319 unsigned long buddy_idx = page_idx ^ (1 << order); 320 321 return page + (buddy_idx - page_idx); 322} 323 324static inline unsigned long 325__find_combined_index(unsigned long page_idx, unsigned int order) 326{ 327 return (page_idx & ~(1 << order)); 328} 329 330/* 331 * This function checks whether a page is free && is the buddy 332 * we can do coalesce a page and its buddy if 333 * (a) the buddy is not in a hole && 334 * (b) the buddy is in the buddy system && 335 * (c) a page and its buddy have the same order && 336 * (d) a page and its buddy are in the same zone. 337 * 338 * For recording whether a page is in the buddy system, we use PG_buddy. 339 * Setting, clearing, and testing PG_buddy is serialized by zone->lock. 340 * 341 * For recording page's order, we use page_private(page). 342 */ 343static inline int page_is_buddy(struct page *page, struct page *buddy, 344 int order) 345{ 346#ifdef CONFIG_HOLES_IN_ZONE 347 if (!pfn_valid(page_to_pfn(buddy))) 348 return 0; 349#endif 350 351 if (page_zone_id(page) != page_zone_id(buddy)) 352 return 0; 353 354 if (PageBuddy(buddy) && page_order(buddy) == order) { 355 BUG_ON(page_count(buddy) != 0); 356 return 1; 357 } 358 return 0; 359} 360 361/* 362 * Freeing function for a buddy system allocator. 363 * 364 * The concept of a buddy system is to maintain direct-mapped table 365 * (containing bit values) for memory blocks of various "orders". 366 * The bottom level table contains the map for the smallest allocatable 367 * units of memory (here, pages), and each level above it describes 368 * pairs of units from the levels below, hence, "buddies". 369 * At a high level, all that happens here is marking the table entry 370 * at the bottom level available, and propagating the changes upward 371 * as necessary, plus some accounting needed to play nicely with other 372 * parts of the VM system. 373 * At each level, we keep a list of pages, which are heads of continuous 374 * free pages of length of (1 << order) and marked with PG_buddy. Page's 375 * order is recorded in page_private(page) field. 376 * So when we are allocating or freeing one, we can derive the state of the 377 * other. That is, if we allocate a small block, and both were 378 * free, the remainder of the region must be split into blocks. 379 * If a block is freed, and its buddy is also free, then this 380 * triggers coalescing into a block of larger size. 381 * 382 * -- wli 383 */ 384 385static inline void __free_one_page(struct page *page, 386 struct zone *zone, unsigned int order) 387{ 388 unsigned long page_idx; 389 int order_size = 1 << order; 390 391 if (unlikely(PageCompound(page))) 392 destroy_compound_page(page, order); 393 394 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); 395 396 VM_BUG_ON(page_idx & (order_size - 1)); 397 VM_BUG_ON(bad_range(zone, page)); 398 399 zone->free_pages += order_size; 400 while (order < MAX_ORDER-1) { 401 unsigned long combined_idx; 402 struct free_area *area; 403 struct page *buddy; 404 405 buddy = __page_find_buddy(page, page_idx, order); 406 if (!page_is_buddy(page, buddy, order)) 407 break; /* Move the buddy up one level. */ 408 409 list_del(&buddy->lru); 410 area = zone->free_area + order; 411 area->nr_free--; 412 rmv_page_order(buddy); 413 combined_idx = __find_combined_index(page_idx, order); 414 page = page + (combined_idx - page_idx); 415 page_idx = combined_idx; 416 order++; 417 } 418 set_page_order(page, order); 419 list_add(&page->lru, &zone->free_area[order].free_list); 420 zone->free_area[order].nr_free++; 421} 422 423static inline int free_pages_check(struct page *page) 424{ 425 if (unlikely(page_mapcount(page) | 426 (page->mapping != NULL) | 427 (page_count(page) != 0) | 428 (page->flags & ( 429 1 << PG_lru | 430 1 << PG_private | 431 1 << PG_locked | 432 1 << PG_active | 433 1 << PG_reclaim | 434 1 << PG_slab | 435 1 << PG_swapcache | 436 1 << PG_writeback | 437 1 << PG_reserved | 438 1 << PG_buddy )))) 439 bad_page(page); 440 if (PageDirty(page)) 441 __ClearPageDirty(page); 442 /* 443 * For now, we report if PG_reserved was found set, but do not 444 * clear it, and do not free the page. But we shall soon need 445 * to do more, for when the ZERO_PAGE count wraps negative. 446 */ 447 return PageReserved(page); 448} 449 450/* 451 * Frees a list of pages. 452 * Assumes all pages on list are in same zone, and of same order. 453 * count is the number of pages to free. 454 * 455 * If the zone was previously in an "all pages pinned" state then look to 456 * see if this freeing clears that state. 457 * 458 * And clear the zone's pages_scanned counter, to hold off the "all pages are 459 * pinned" detection logic. 460 */ 461static void free_pages_bulk(struct zone *zone, int count, 462 struct list_head *list, int order) 463{ 464 spin_lock(&zone->lock); 465 zone->all_unreclaimable = 0; 466 zone->pages_scanned = 0; 467 while (count--) { 468 struct page *page; 469 470 VM_BUG_ON(list_empty(list)); 471 page = list_entry(list->prev, struct page, lru); 472 /* have to delete it as __free_one_page list manipulates */ 473 list_del(&page->lru); 474 __free_one_page(page, zone, order); 475 } 476 spin_unlock(&zone->lock); 477} 478 479static void free_one_page(struct zone *zone, struct page *page, int order) 480{ 481 spin_lock(&zone->lock); 482 zone->all_unreclaimable = 0; 483 zone->pages_scanned = 0; 484 __free_one_page(page, zone ,order); 485 spin_unlock(&zone->lock); 486} 487 488static void __free_pages_ok(struct page *page, unsigned int order) 489{ 490 unsigned long flags; 491 int i; 492 int reserved = 0; 493 494 arch_free_page(page, order); 495 if (!PageHighMem(page)) 496 debug_check_no_locks_freed(page_address(page), 497 PAGE_SIZE<<order); 498 499 for (i = 0 ; i < (1 << order) ; ++i) 500 reserved += free_pages_check(page + i); 501 if (reserved) 502 return; 503 504 kernel_map_pages(page, 1 << order, 0); 505 local_irq_save(flags); 506 __count_vm_events(PGFREE, 1 << order); 507 free_one_page(page_zone(page), page, order); 508 local_irq_restore(flags); 509} 510 511/* 512 * permit the bootmem allocator to evade page validation on high-order frees 513 */ 514void fastcall __init __free_pages_bootmem(struct page *page, unsigned int order) 515{ 516 if (order == 0) { 517 __ClearPageReserved(page); 518 set_page_count(page, 0); 519 set_page_refcounted(page); 520 __free_page(page); 521 } else { 522 int loop; 523 524 prefetchw(page); 525 for (loop = 0; loop < BITS_PER_LONG; loop++) { 526 struct page *p = &page[loop]; 527 528 if (loop + 1 < BITS_PER_LONG) 529 prefetchw(p + 1); 530 __ClearPageReserved(p); 531 set_page_count(p, 0); 532 } 533 534 set_page_refcounted(page); 535 __free_pages(page, order); 536 } 537} 538 539 540/* 541 * The order of subdivision here is critical for the IO subsystem. 542 * Please do not alter this order without good reasons and regression 543 * testing. Specifically, as large blocks of memory are subdivided, 544 * the order in which smaller blocks are delivered depends on the order 545 * they're subdivided in this function. This is the primary factor 546 * influencing the order in which pages are delivered to the IO 547 * subsystem according to empirical testing, and this is also justified 548 * by considering the behavior of a buddy system containing a single 549 * large block of memory acted on by a series of small allocations. 550 * This behavior is a critical factor in sglist merging's success. 551 * 552 * -- wli 553 */ 554static inline void expand(struct zone *zone, struct page *page, 555 int low, int high, struct free_area *area) 556{ 557 unsigned long size = 1 << high; 558 559 while (high > low) { 560 area--; 561 high--; 562 size >>= 1; 563 VM_BUG_ON(bad_range(zone, &page[size])); 564 list_add(&page[size].lru, &area->free_list); 565 area->nr_free++; 566 set_page_order(&page[size], high); 567 } 568} 569 570/* 571 * This page is about to be returned from the page allocator 572 */ 573static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) 574{ 575 if (unlikely(page_mapcount(page) | 576 (page->mapping != NULL) | 577 (page_count(page) != 0) | 578 (page->flags & ( 579 1 << PG_lru | 580 1 << PG_private | 581 1 << PG_locked | 582 1 << PG_active | 583 1 << PG_dirty | 584 1 << PG_reclaim | 585 1 << PG_slab | 586 1 << PG_swapcache | 587 1 << PG_writeback | 588 1 << PG_reserved | 589 1 << PG_buddy )))) 590 bad_page(page); 591 592 /* 593 * For now, we report if PG_reserved was found set, but do not 594 * clear it, and do not allocate the page: as a safety net. 595 */ 596 if (PageReserved(page)) 597 return 1; 598 599 page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 600 1 << PG_referenced | 1 << PG_arch_1 | 601 1 << PG_checked | 1 << PG_mappedtodisk); 602 set_page_private(page, 0); 603 set_page_refcounted(page); 604 kernel_map_pages(page, 1 << order, 1); 605 606 if (gfp_flags & __GFP_ZERO) 607 prep_zero_page(page, order, gfp_flags); 608 609 if (order && (gfp_flags & __GFP_COMP)) 610 prep_compound_page(page, order); 611 612 return 0; 613} 614 615/* 616 * Do the hard work of removing an element from the buddy allocator. 617 * Call me with the zone->lock already held. 618 */ 619static struct page *__rmqueue(struct zone *zone, unsigned int order) 620{ 621 struct free_area * area; 622 unsigned int current_order; 623 struct page *page; 624 625 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 626 area = zone->free_area + current_order; 627 if (list_empty(&area->free_list)) 628 continue; 629 630 page = list_entry(area->free_list.next, struct page, lru); 631 list_del(&page->lru); 632 rmv_page_order(page); 633 area->nr_free--; 634 zone->free_pages -= 1UL << order; 635 expand(zone, page, order, current_order, area); 636 return page; 637 } 638 639 return NULL; 640} 641 642/* 643 * Obtain a specified number of elements from the buddy allocator, all under 644 * a single hold of the lock, for efficiency. Add them to the supplied list. 645 * Returns the number of new pages which were placed at *list. 646 */ 647static int rmqueue_bulk(struct zone *zone, unsigned int order, 648 unsigned long count, struct list_head *list) 649{ 650 int i; 651 652 spin_lock(&zone->lock); 653 for (i = 0; i < count; ++i) { 654 struct page *page = __rmqueue(zone, order); 655 if (unlikely(page == NULL)) 656 break; 657 list_add_tail(&page->lru, list); 658 } 659 spin_unlock(&zone->lock); 660 return i; 661} 662 663#ifdef CONFIG_NUMA 664/* 665 * Called from the slab reaper to drain pagesets on a particular node that 666 * belongs to the currently executing processor. 667 * Note that this function must be called with the thread pinned to 668 * a single processor. 669 */ 670void drain_node_pages(int nodeid) 671{ 672 int i; 673 enum zone_type z; 674 unsigned long flags; 675 676 for (z = 0; z < MAX_NR_ZONES; z++) { 677 struct zone *zone = NODE_DATA(nodeid)->node_zones + z; 678 struct per_cpu_pageset *pset; 679 680 if (!populated_zone(zone)) 681 continue; 682 683 pset = zone_pcp(zone, smp_processor_id()); 684 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) { 685 struct per_cpu_pages *pcp; 686 687 pcp = &pset->pcp[i]; 688 if (pcp->count) { 689 local_irq_save(flags); 690 free_pages_bulk(zone, pcp->count, &pcp->list, 0); 691 pcp->count = 0; 692 local_irq_restore(flags); 693 } 694 } 695 } 696} 697#endif 698 699#if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU) 700static void __drain_pages(unsigned int cpu) 701{ 702 unsigned long flags; 703 struct zone *zone; 704 int i; 705 706 for_each_zone(zone) { 707 struct per_cpu_pageset *pset; 708 709 pset = zone_pcp(zone, cpu); 710 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) { 711 struct per_cpu_pages *pcp; 712 713 pcp = &pset->pcp[i]; 714 local_irq_save(flags); 715 free_pages_bulk(zone, pcp->count, &pcp->list, 0); 716 pcp->count = 0; 717 local_irq_restore(flags); 718 } 719 } 720} 721#endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */ 722 723#ifdef CONFIG_PM 724 725void mark_free_pages(struct zone *zone) 726{ 727 unsigned long pfn, max_zone_pfn; 728 unsigned long flags; 729 int order; 730 struct list_head *curr; 731 732 if (!zone->spanned_pages) 733 return; 734 735 spin_lock_irqsave(&zone->lock, flags); 736 737 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; 738 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 739 if (pfn_valid(pfn)) { 740 struct page *page = pfn_to_page(pfn); 741 742 if (!PageNosave(page)) 743 ClearPageNosaveFree(page); 744 } 745 746 for (order = MAX_ORDER - 1; order >= 0; --order) 747 list_for_each(curr, &zone->free_area[order].free_list) { 748 unsigned long i; 749 750 pfn = page_to_pfn(list_entry(curr, struct page, lru)); 751 for (i = 0; i < (1UL << order); i++) 752 SetPageNosaveFree(pfn_to_page(pfn + i)); 753 } 754 755 spin_unlock_irqrestore(&zone->lock, flags); 756} 757 758/* 759 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 760 */ 761void drain_local_pages(void) 762{ 763 unsigned long flags; 764 765 local_irq_save(flags); 766 __drain_pages(smp_processor_id()); 767 local_irq_restore(flags); 768} 769#endif /* CONFIG_PM */ 770 771/* 772 * Free a 0-order page 773 */ 774static void fastcall free_hot_cold_page(struct page *page, int cold) 775{ 776 struct zone *zone = page_zone(page); 777 struct per_cpu_pages *pcp; 778 unsigned long flags; 779 780 arch_free_page(page, 0); 781 782 if (PageAnon(page)) 783 page->mapping = NULL; 784 if (free_pages_check(page)) 785 return; 786 787 kernel_map_pages(page, 1, 0); 788 789 pcp = &zone_pcp(zone, get_cpu())->pcp[cold]; 790 local_irq_save(flags); 791 __count_vm_event(PGFREE); 792 list_add(&page->lru, &pcp->list); 793 pcp->count++; 794 if (pcp->count >= pcp->high) { 795 free_pages_bulk(zone, pcp->batch, &pcp->list, 0); 796 pcp->count -= pcp->batch; 797 } 798 local_irq_restore(flags); 799 put_cpu(); 800} 801 802void fastcall free_hot_page(struct page *page) 803{ 804 free_hot_cold_page(page, 0); 805} 806 807void fastcall free_cold_page(struct page *page) 808{ 809 free_hot_cold_page(page, 1); 810} 811 812/* 813 * split_page takes a non-compound higher-order page, and splits it into 814 * n (1<<order) sub-pages: page[0..n] 815 * Each sub-page must be freed individually. 816 * 817 * Note: this is probably too low level an operation for use in drivers. 818 * Please consult with lkml before using this in your driver. 819 */ 820void split_page(struct page *page, unsigned int order) 821{ 822 int i; 823 824 VM_BUG_ON(PageCompound(page)); 825 VM_BUG_ON(!page_count(page)); 826 for (i = 1; i < (1 << order); i++) 827 set_page_refcounted(page + i); 828} 829 830/* 831 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 832 * we cheat by calling it from here, in the order > 0 path. Saves a branch 833 * or two. 834 */ 835static struct page *buffered_rmqueue(struct zonelist *zonelist, 836 struct zone *zone, int order, gfp_t gfp_flags) 837{ 838 unsigned long flags; 839 struct page *page; 840 int cold = !!(gfp_flags & __GFP_COLD); 841 int cpu; 842 843again: 844 cpu = get_cpu(); 845 if (likely(order == 0)) { 846 struct per_cpu_pages *pcp; 847 848 pcp = &zone_pcp(zone, cpu)->pcp[cold]; 849 local_irq_save(flags); 850 if (!pcp->count) { 851 pcp->count += rmqueue_bulk(zone, 0, 852 pcp->batch, &pcp->list); 853 if (unlikely(!pcp->count)) 854 goto failed; 855 } 856 page = list_entry(pcp->list.next, struct page, lru); 857 list_del(&page->lru); 858 pcp->count--; 859 } else { 860 spin_lock_irqsave(&zone->lock, flags); 861 page = __rmqueue(zone, order); 862 spin_unlock(&zone->lock); 863 if (!page) 864 goto failed; 865 } 866 867 __count_zone_vm_events(PGALLOC, zone, 1 << order); 868 zone_statistics(zonelist, zone); 869 local_irq_restore(flags); 870 put_cpu(); 871 872 VM_BUG_ON(bad_range(zone, page)); 873 if (prep_new_page(page, order, gfp_flags)) 874 goto again; 875 return page; 876 877failed: 878 local_irq_restore(flags); 879 put_cpu(); 880 return NULL; 881} 882 883#define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */ 884#define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */ 885#define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */ 886#define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */ 887#define ALLOC_HARDER 0x10 /* try to alloc harder */ 888#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 889#define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 890 891/* 892 * Return 1 if free pages are above 'mark'. This takes into account the order 893 * of the allocation. 894 */ 895int zone_watermark_ok(struct zone *z, int order, unsigned long mark, 896 int classzone_idx, int alloc_flags) 897{ 898 /* free_pages my go negative - that's OK */ 899 long min = mark, free_pages = z->free_pages - (1 << order) + 1; 900 int o; 901 902 if (alloc_flags & ALLOC_HIGH) 903 min -= min / 2; 904 if (alloc_flags & ALLOC_HARDER) 905 min -= min / 4; 906 907 if (free_pages <= min + z->lowmem_reserve[classzone_idx]) 908 return 0; 909 for (o = 0; o < order; o++) { 910 /* At the next order, this order's pages become unavailable */ 911 free_pages -= z->free_area[o].nr_free << o; 912 913 /* Require fewer higher order pages to be free */ 914 min >>= 1; 915 916 if (free_pages <= min) 917 return 0; 918 } 919 return 1; 920} 921 922/* 923 * get_page_from_freeliest goes through the zonelist trying to allocate 924 * a page. 925 */ 926static struct page * 927get_page_from_freelist(gfp_t gfp_mask, unsigned int order, 928 struct zonelist *zonelist, int alloc_flags) 929{ 930 struct zone **z = zonelist->zones; 931 struct page *page = NULL; 932 int classzone_idx = zone_idx(*z); 933 struct zone *zone; 934 935 /* 936 * Go through the zonelist once, looking for a zone with enough free. 937 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 938 */ 939 do { 940 zone = *z; 941 if (unlikely((gfp_mask & __GFP_THISNODE) && 942 zone->zone_pgdat != zonelist->zones[0]->zone_pgdat)) 943 break; 944 if ((alloc_flags & ALLOC_CPUSET) && 945 !cpuset_zone_allowed(zone, gfp_mask)) 946 continue; 947 948 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { 949 unsigned long mark; 950 if (alloc_flags & ALLOC_WMARK_MIN) 951 mark = zone->pages_min; 952 else if (alloc_flags & ALLOC_WMARK_LOW) 953 mark = zone->pages_low; 954 else 955 mark = zone->pages_high; 956 if (!zone_watermark_ok(zone , order, mark, 957 classzone_idx, alloc_flags)) 958 if (!zone_reclaim_mode || 959 !zone_reclaim(zone, gfp_mask, order)) 960 continue; 961 } 962 963 page = buffered_rmqueue(zonelist, zone, order, gfp_mask); 964 if (page) { 965 break; 966 } 967 } while (*(++z) != NULL); 968 return page; 969} 970 971/* 972 * This is the 'heart' of the zoned buddy allocator. 973 */ 974struct page * fastcall 975__alloc_pages(gfp_t gfp_mask, unsigned int order, 976 struct zonelist *zonelist) 977{ 978 const gfp_t wait = gfp_mask & __GFP_WAIT; 979 struct zone **z; 980 struct page *page; 981 struct reclaim_state reclaim_state; 982 struct task_struct *p = current; 983 int do_retry; 984 int alloc_flags; 985 int did_some_progress; 986 987 might_sleep_if(wait); 988 989restart: 990 z = zonelist->zones; /* the list of zones suitable for gfp_mask */ 991 992 if (unlikely(*z == NULL)) { 993 /* Should this ever happen?? */ 994 return NULL; 995 } 996 997 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order, 998 zonelist, ALLOC_WMARK_LOW|ALLOC_CPUSET); 999 if (page) 1000 goto got_pg; 1001 1002 do { 1003 wakeup_kswapd(*z, order); 1004 } while (*(++z)); 1005 1006 /* 1007 * OK, we're below the kswapd watermark and have kicked background 1008 * reclaim. Now things get more complex, so set up alloc_flags according 1009 * to how we want to proceed. 1010 * 1011 * The caller may dip into page reserves a bit more if the caller 1012 * cannot run direct reclaim, or if the caller has realtime scheduling 1013 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will 1014 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). 1015 */ 1016 alloc_flags = ALLOC_WMARK_MIN; 1017 if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait) 1018 alloc_flags |= ALLOC_HARDER; 1019 if (gfp_mask & __GFP_HIGH) 1020 alloc_flags |= ALLOC_HIGH; 1021 if (wait) 1022 alloc_flags |= ALLOC_CPUSET; 1023 1024 /* 1025 * Go through the zonelist again. Let __GFP_HIGH and allocations 1026 * coming from realtime tasks go deeper into reserves. 1027 * 1028 * This is the last chance, in general, before the goto nopage. 1029 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. 1030 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1031 */ 1032 page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags); 1033 if (page) 1034 goto got_pg; 1035 1036 /* This allocation should allow future memory freeing. */ 1037 1038 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) 1039 && !in_interrupt()) { 1040 if (!(gfp_mask & __GFP_NOMEMALLOC)) { 1041nofail_alloc: 1042 /* go through the zonelist yet again, ignoring mins */ 1043 page = get_page_from_freelist(gfp_mask, order, 1044 zonelist, ALLOC_NO_WATERMARKS); 1045 if (page) 1046 goto got_pg; 1047 if (gfp_mask & __GFP_NOFAIL) { 1048 blk_congestion_wait(WRITE, HZ/50); 1049 goto nofail_alloc; 1050 } 1051 } 1052 goto nopage; 1053 } 1054 1055 /* Atomic allocations - we can't balance anything */ 1056 if (!wait) 1057 goto nopage; 1058 1059rebalance: 1060 cond_resched(); 1061 1062 /* We now go into synchronous reclaim */ 1063 cpuset_memory_pressure_bump(); 1064 p->flags |= PF_MEMALLOC; 1065 reclaim_state.reclaimed_slab = 0; 1066 p->reclaim_state = &reclaim_state; 1067 1068 did_some_progress = try_to_free_pages(zonelist->zones, gfp_mask); 1069 1070 p->reclaim_state = NULL; 1071 p->flags &= ~PF_MEMALLOC; 1072 1073 cond_resched(); 1074 1075 if (likely(did_some_progress)) { 1076 page = get_page_from_freelist(gfp_mask, order, 1077 zonelist, alloc_flags); 1078 if (page) 1079 goto got_pg; 1080 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { 1081 /* 1082 * Go through the zonelist yet one more time, keep 1083 * very high watermark here, this is only to catch 1084 * a parallel oom killing, we must fail if we're still 1085 * under heavy pressure. 1086 */ 1087 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order, 1088 zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET); 1089 if (page) 1090 goto got_pg; 1091 1092 out_of_memory(zonelist, gfp_mask, order); 1093 goto restart; 1094 } 1095 1096 /* 1097 * Don't let big-order allocations loop unless the caller explicitly 1098 * requests that. Wait for some write requests to complete then retry. 1099 * 1100 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order 1101 * <= 3, but that may not be true in other implementations. 1102 */ 1103 do_retry = 0; 1104 if (!(gfp_mask & __GFP_NORETRY)) { 1105 if ((order <= 3) || (gfp_mask & __GFP_REPEAT)) 1106 do_retry = 1; 1107 if (gfp_mask & __GFP_NOFAIL) 1108 do_retry = 1; 1109 } 1110 if (do_retry) { 1111 blk_congestion_wait(WRITE, HZ/50); 1112 goto rebalance; 1113 } 1114 1115nopage: 1116 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { 1117 printk(KERN_WARNING "%s: page allocation failure." 1118 " order:%d, mode:0x%x\n", 1119 p->comm, order, gfp_mask); 1120 dump_stack(); 1121 show_mem(); 1122 } 1123got_pg: 1124 return page; 1125} 1126 1127EXPORT_SYMBOL(__alloc_pages); 1128 1129/* 1130 * Common helper functions. 1131 */ 1132fastcall unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 1133{ 1134 struct page * page; 1135 page = alloc_pages(gfp_mask, order); 1136 if (!page) 1137 return 0; 1138 return (unsigned long) page_address(page); 1139} 1140 1141EXPORT_SYMBOL(__get_free_pages); 1142 1143fastcall unsigned long get_zeroed_page(gfp_t gfp_mask) 1144{ 1145 struct page * page; 1146 1147 /* 1148 * get_zeroed_page() returns a 32-bit address, which cannot represent 1149 * a highmem page 1150 */ 1151 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 1152 1153 page = alloc_pages(gfp_mask | __GFP_ZERO, 0); 1154 if (page) 1155 return (unsigned long) page_address(page); 1156 return 0; 1157} 1158 1159EXPORT_SYMBOL(get_zeroed_page); 1160 1161void __pagevec_free(struct pagevec *pvec) 1162{ 1163 int i = pagevec_count(pvec); 1164 1165 while (--i >= 0) 1166 free_hot_cold_page(pvec->pages[i], pvec->cold); 1167} 1168 1169fastcall void __free_pages(struct page *page, unsigned int order) 1170{ 1171 if (put_page_testzero(page)) { 1172 if (order == 0) 1173 free_hot_page(page); 1174 else 1175 __free_pages_ok(page, order); 1176 } 1177} 1178 1179EXPORT_SYMBOL(__free_pages); 1180 1181fastcall void free_pages(unsigned long addr, unsigned int order) 1182{ 1183 if (addr != 0) { 1184 VM_BUG_ON(!virt_addr_valid((void *)addr)); 1185 __free_pages(virt_to_page((void *)addr), order); 1186 } 1187} 1188 1189EXPORT_SYMBOL(free_pages); 1190 1191/* 1192 * Total amount of free (allocatable) RAM: 1193 */ 1194unsigned int nr_free_pages(void) 1195{ 1196 unsigned int sum = 0; 1197 struct zone *zone; 1198 1199 for_each_zone(zone) 1200 sum += zone->free_pages; 1201 1202 return sum; 1203} 1204 1205EXPORT_SYMBOL(nr_free_pages); 1206 1207#ifdef CONFIG_NUMA 1208unsigned int nr_free_pages_pgdat(pg_data_t *pgdat) 1209{ 1210 unsigned int sum = 0; 1211 enum zone_type i; 1212 1213 for (i = 0; i < MAX_NR_ZONES; i++) 1214 sum += pgdat->node_zones[i].free_pages; 1215 1216 return sum; 1217} 1218#endif 1219 1220static unsigned int nr_free_zone_pages(int offset) 1221{ 1222 /* Just pick one node, since fallback list is circular */ 1223 pg_data_t *pgdat = NODE_DATA(numa_node_id()); 1224 unsigned int sum = 0; 1225 1226 struct zonelist *zonelist = pgdat->node_zonelists + offset; 1227 struct zone **zonep = zonelist->zones; 1228 struct zone *zone; 1229 1230 for (zone = *zonep++; zone; zone = *zonep++) { 1231 unsigned long size = zone->present_pages; 1232 unsigned long high = zone->pages_high; 1233 if (size > high) 1234 sum += size - high; 1235 } 1236 1237 return sum; 1238} 1239 1240/* 1241 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL 1242 */ 1243unsigned int nr_free_buffer_pages(void) 1244{ 1245 return nr_free_zone_pages(gfp_zone(GFP_USER)); 1246} 1247 1248/* 1249 * Amount of free RAM allocatable within all zones 1250 */ 1251unsigned int nr_free_pagecache_pages(void) 1252{ 1253 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER)); 1254} 1255#ifdef CONFIG_NUMA 1256static void show_node(struct zone *zone) 1257{ 1258 printk("Node %ld ", zone_to_nid(zone)); 1259} 1260#else 1261#define show_node(zone) do { } while (0) 1262#endif 1263 1264void si_meminfo(struct sysinfo *val) 1265{ 1266 val->totalram = totalram_pages; 1267 val->sharedram = 0; 1268 val->freeram = nr_free_pages(); 1269 val->bufferram = nr_blockdev_pages(); 1270 val->totalhigh = totalhigh_pages; 1271 val->freehigh = nr_free_highpages(); 1272 val->mem_unit = PAGE_SIZE; 1273} 1274 1275EXPORT_SYMBOL(si_meminfo); 1276 1277#ifdef CONFIG_NUMA 1278void si_meminfo_node(struct sysinfo *val, int nid) 1279{ 1280 pg_data_t *pgdat = NODE_DATA(nid); 1281 1282 val->totalram = pgdat->node_present_pages; 1283 val->freeram = nr_free_pages_pgdat(pgdat); 1284#ifdef CONFIG_HIGHMEM 1285 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; 1286 val->freehigh = pgdat->node_zones[ZONE_HIGHMEM].free_pages; 1287#else 1288 val->totalhigh = 0; 1289 val->freehigh = 0; 1290#endif 1291 val->mem_unit = PAGE_SIZE; 1292} 1293#endif 1294 1295#define K(x) ((x) << (PAGE_SHIFT-10)) 1296 1297/* 1298 * Show free area list (used inside shift_scroll-lock stuff) 1299 * We also calculate the percentage fragmentation. We do this by counting the 1300 * memory on each free list with the exception of the first item on the list. 1301 */ 1302void show_free_areas(void) 1303{ 1304 int cpu, temperature; 1305 unsigned long active; 1306 unsigned long inactive; 1307 unsigned long free; 1308 struct zone *zone; 1309 1310 for_each_zone(zone) { 1311 show_node(zone); 1312 printk("%s per-cpu:", zone->name); 1313 1314 if (!populated_zone(zone)) { 1315 printk(" empty\n"); 1316 continue; 1317 } else 1318 printk("\n"); 1319 1320 for_each_online_cpu(cpu) { 1321 struct per_cpu_pageset *pageset; 1322 1323 pageset = zone_pcp(zone, cpu); 1324 1325 for (temperature = 0; temperature < 2; temperature++) 1326 printk("cpu %d %s: high %d, batch %d used:%d\n", 1327 cpu, 1328 temperature ? "cold" : "hot", 1329 pageset->pcp[temperature].high, 1330 pageset->pcp[temperature].batch, 1331 pageset->pcp[temperature].count); 1332 } 1333 } 1334 1335 get_zone_counts(&active, &inactive, &free); 1336 1337 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu " 1338 "unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n", 1339 active, 1340 inactive, 1341 global_page_state(NR_FILE_DIRTY), 1342 global_page_state(NR_WRITEBACK), 1343 global_page_state(NR_UNSTABLE_NFS), 1344 nr_free_pages(), 1345 global_page_state(NR_SLAB_RECLAIMABLE) + 1346 global_page_state(NR_SLAB_UNRECLAIMABLE), 1347 global_page_state(NR_FILE_MAPPED), 1348 global_page_state(NR_PAGETABLE)); 1349 1350 for_each_zone(zone) { 1351 int i; 1352 1353 show_node(zone); 1354 printk("%s" 1355 " free:%lukB" 1356 " min:%lukB" 1357 " low:%lukB" 1358 " high:%lukB" 1359 " active:%lukB" 1360 " inactive:%lukB" 1361 " present:%lukB" 1362 " pages_scanned:%lu" 1363 " all_unreclaimable? %s" 1364 "\n", 1365 zone->name, 1366 K(zone->free_pages), 1367 K(zone->pages_min), 1368 K(zone->pages_low), 1369 K(zone->pages_high), 1370 K(zone->nr_active), 1371 K(zone->nr_inactive), 1372 K(zone->present_pages), 1373 zone->pages_scanned, 1374 (zone->all_unreclaimable ? "yes" : "no") 1375 ); 1376 printk("lowmem_reserve[]:"); 1377 for (i = 0; i < MAX_NR_ZONES; i++) 1378 printk(" %lu", zone->lowmem_reserve[i]); 1379 printk("\n"); 1380 } 1381 1382 for_each_zone(zone) { 1383 unsigned long nr[MAX_ORDER], flags, order, total = 0; 1384 1385 show_node(zone); 1386 printk("%s: ", zone->name); 1387 if (!populated_zone(zone)) { 1388 printk("empty\n"); 1389 continue; 1390 } 1391 1392 spin_lock_irqsave(&zone->lock, flags); 1393 for (order = 0; order < MAX_ORDER; order++) { 1394 nr[order] = zone->free_area[order].nr_free; 1395 total += nr[order] << order; 1396 } 1397 spin_unlock_irqrestore(&zone->lock, flags); 1398 for (order = 0; order < MAX_ORDER; order++) 1399 printk("%lu*%lukB ", nr[order], K(1UL) << order); 1400 printk("= %lukB\n", K(total)); 1401 } 1402 1403 show_swap_cache_info(); 1404} 1405 1406/* 1407 * Builds allocation fallback zone lists. 1408 * 1409 * Add all populated zones of a node to the zonelist. 1410 */ 1411static int __meminit build_zonelists_node(pg_data_t *pgdat, 1412 struct zonelist *zonelist, int nr_zones, enum zone_type zone_type) 1413{ 1414 struct zone *zone; 1415 1416 BUG_ON(zone_type >= MAX_NR_ZONES); 1417 zone_type++; 1418 1419 do { 1420 zone_type--; 1421 zone = pgdat->node_zones + zone_type; 1422 if (populated_zone(zone)) { 1423 zonelist->zones[nr_zones++] = zone; 1424 check_highest_zone(zone_type); 1425 } 1426 1427 } while (zone_type); 1428 return nr_zones; 1429} 1430 1431#ifdef CONFIG_NUMA 1432#define MAX_NODE_LOAD (num_online_nodes()) 1433static int __meminitdata node_load[MAX_NUMNODES]; 1434/** 1435 * find_next_best_node - find the next node that should appear in a given node's fallback list 1436 * @node: node whose fallback list we're appending 1437 * @used_node_mask: nodemask_t of already used nodes 1438 * 1439 * We use a number of factors to determine which is the next node that should 1440 * appear on a given node's fallback list. The node should not have appeared 1441 * already in @node's fallback list, and it should be the next closest node 1442 * according to the distance array (which contains arbitrary distance values 1443 * from each node to each node in the system), and should also prefer nodes 1444 * with no CPUs, since presumably they'll have very little allocation pressure 1445 * on them otherwise. 1446 * It returns -1 if no node is found. 1447 */ 1448static int __meminit find_next_best_node(int node, nodemask_t *used_node_mask) 1449{ 1450 int n, val; 1451 int min_val = INT_MAX; 1452 int best_node = -1; 1453 1454 /* Use the local node if we haven't already */ 1455 if (!node_isset(node, *used_node_mask)) { 1456 node_set(node, *used_node_mask); 1457 return node; 1458 } 1459 1460 for_each_online_node(n) { 1461 cpumask_t tmp; 1462 1463 /* Don't want a node to appear more than once */ 1464 if (node_isset(n, *used_node_mask)) 1465 continue; 1466 1467 /* Use the distance array to find the distance */ 1468 val = node_distance(node, n); 1469 1470 /* Penalize nodes under us ("prefer the next node") */ 1471 val += (n < node); 1472 1473 /* Give preference to headless and unused nodes */ 1474 tmp = node_to_cpumask(n); 1475 if (!cpus_empty(tmp)) 1476 val += PENALTY_FOR_NODE_WITH_CPUS; 1477 1478 /* Slight preference for less loaded node */ 1479 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 1480 val += node_load[n]; 1481 1482 if (val < min_val) { 1483 min_val = val; 1484 best_node = n; 1485 } 1486 } 1487 1488 if (best_node >= 0) 1489 node_set(best_node, *used_node_mask); 1490 1491 return best_node; 1492} 1493 1494static void __meminit build_zonelists(pg_data_t *pgdat) 1495{ 1496 int j, node, local_node; 1497 enum zone_type i; 1498 int prev_node, load; 1499 struct zonelist *zonelist; 1500 nodemask_t used_mask; 1501 1502 /* initialize zonelists */ 1503 for (i = 0; i < MAX_NR_ZONES; i++) { 1504 zonelist = pgdat->node_zonelists + i; 1505 zonelist->zones[0] = NULL; 1506 } 1507 1508 /* NUMA-aware ordering of nodes */ 1509 local_node = pgdat->node_id; 1510 load = num_online_nodes(); 1511 prev_node = local_node; 1512 nodes_clear(used_mask); 1513 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 1514 int distance = node_distance(local_node, node); 1515 1516 /* 1517 * If another node is sufficiently far away then it is better 1518 * to reclaim pages in a zone before going off node. 1519 */ 1520 if (distance > RECLAIM_DISTANCE) 1521 zone_reclaim_mode = 1; 1522 1523 /* 1524 * We don't want to pressure a particular node. 1525 * So adding penalty to the first node in same 1526 * distance group to make it round-robin. 1527 */ 1528 1529 if (distance != node_distance(local_node, prev_node)) 1530 node_load[node] += load; 1531 prev_node = node; 1532 load--; 1533 for (i = 0; i < MAX_NR_ZONES; i++) { 1534 zonelist = pgdat->node_zonelists + i; 1535 for (j = 0; zonelist->zones[j] != NULL; j++); 1536 1537 j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); 1538 zonelist->zones[j] = NULL; 1539 } 1540 } 1541} 1542 1543#else /* CONFIG_NUMA */ 1544 1545static void __meminit build_zonelists(pg_data_t *pgdat) 1546{ 1547 int node, local_node; 1548 enum zone_type i,j; 1549 1550 local_node = pgdat->node_id; 1551 for (i = 0; i < MAX_NR_ZONES; i++) { 1552 struct zonelist *zonelist; 1553 1554 zonelist = pgdat->node_zonelists + i; 1555 1556 j = build_zonelists_node(pgdat, zonelist, 0, i); 1557 /* 1558 * Now we build the zonelist so that it contains the zones 1559 * of all the other nodes. 1560 * We don't want to pressure a particular node, so when 1561 * building the zones for node N, we make sure that the 1562 * zones coming right after the local ones are those from 1563 * node N+1 (modulo N) 1564 */ 1565 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 1566 if (!node_online(node)) 1567 continue; 1568 j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); 1569 } 1570 for (node = 0; node < local_node; node++) { 1571 if (!node_online(node)) 1572 continue; 1573 j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); 1574 } 1575 1576 zonelist->zones[j] = NULL; 1577 } 1578} 1579 1580#endif /* CONFIG_NUMA */ 1581 1582/* return values int ....just for stop_machine_run() */ 1583static int __meminit __build_all_zonelists(void *dummy) 1584{ 1585 int nid; 1586 for_each_online_node(nid) 1587 build_zonelists(NODE_DATA(nid)); 1588 return 0; 1589} 1590 1591void __meminit build_all_zonelists(void) 1592{ 1593 if (system_state == SYSTEM_BOOTING) { 1594 __build_all_zonelists(0); 1595 cpuset_init_current_mems_allowed(); 1596 } else { 1597 /* we have to stop all cpus to guaranntee there is no user 1598 of zonelist */ 1599 stop_machine_run(__build_all_zonelists, NULL, NR_CPUS); 1600 /* cpuset refresh routine should be here */ 1601 } 1602 vm_total_pages = nr_free_pagecache_pages(); 1603 printk("Built %i zonelists. Total pages: %ld\n", 1604 num_online_nodes(), vm_total_pages); 1605} 1606 1607/* 1608 * Helper functions to size the waitqueue hash table. 1609 * Essentially these want to choose hash table sizes sufficiently 1610 * large so that collisions trying to wait on pages are rare. 1611 * But in fact, the number of active page waitqueues on typical 1612 * systems is ridiculously low, less than 200. So this is even 1613 * conservative, even though it seems large. 1614 * 1615 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 1616 * waitqueues, i.e. the size of the waitq table given the number of pages. 1617 */ 1618#define PAGES_PER_WAITQUEUE 256 1619 1620#ifndef CONFIG_MEMORY_HOTPLUG 1621static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 1622{ 1623 unsigned long size = 1; 1624 1625 pages /= PAGES_PER_WAITQUEUE; 1626 1627 while (size < pages) 1628 size <<= 1; 1629 1630 /* 1631 * Once we have dozens or even hundreds of threads sleeping 1632 * on IO we've got bigger problems than wait queue collision. 1633 * Limit the size of the wait table to a reasonable size. 1634 */ 1635 size = min(size, 4096UL); 1636 1637 return max(size, 4UL); 1638} 1639#else 1640/* 1641 * A zone's size might be changed by hot-add, so it is not possible to determine 1642 * a suitable size for its wait_table. So we use the maximum size now. 1643 * 1644 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: 1645 * 1646 * i386 (preemption config) : 4096 x 16 = 64Kbyte. 1647 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. 1648 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. 1649 * 1650 * The maximum entries are prepared when a zone's memory is (512K + 256) pages 1651 * or more by the traditional way. (See above). It equals: 1652 * 1653 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. 1654 * ia64(16K page size) : = ( 8G + 4M)byte. 1655 * powerpc (64K page size) : = (32G +16M)byte. 1656 */ 1657static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 1658{ 1659 return 4096UL; 1660} 1661#endif 1662 1663/* 1664 * This is an integer logarithm so that shifts can be used later 1665 * to extract the more random high bits from the multiplicative 1666 * hash function before the remainder is taken. 1667 */ 1668static inline unsigned long wait_table_bits(unsigned long size) 1669{ 1670 return ffz(~size); 1671} 1672 1673#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) 1674 1675/* 1676 * Initially all pages are reserved - free ones are freed 1677 * up by free_all_bootmem() once the early boot process is 1678 * done. Non-atomic initialization, single-pass. 1679 */ 1680void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 1681 unsigned long start_pfn) 1682{ 1683 struct page *page; 1684 unsigned long end_pfn = start_pfn + size; 1685 unsigned long pfn; 1686 1687 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1688 if (!early_pfn_valid(pfn)) 1689 continue; 1690 page = pfn_to_page(pfn); 1691 set_page_links(page, zone, nid, pfn); 1692 init_page_count(page); 1693 reset_page_mapcount(page); 1694 SetPageReserved(page); 1695 INIT_LIST_HEAD(&page->lru); 1696#ifdef WANT_PAGE_VIRTUAL 1697 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 1698 if (!is_highmem_idx(zone)) 1699 set_page_address(page, __va(pfn << PAGE_SHIFT)); 1700#endif 1701 } 1702} 1703 1704void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone, 1705 unsigned long size) 1706{ 1707 int order; 1708 for (order = 0; order < MAX_ORDER ; order++) { 1709 INIT_LIST_HEAD(&zone->free_area[order].free_list); 1710 zone->free_area[order].nr_free = 0; 1711 } 1712} 1713 1714#define ZONETABLE_INDEX(x, zone_nr) ((x << ZONES_SHIFT) | zone_nr) 1715void zonetable_add(struct zone *zone, int nid, enum zone_type zid, 1716 unsigned long pfn, unsigned long size) 1717{ 1718 unsigned long snum = pfn_to_section_nr(pfn); 1719 unsigned long end = pfn_to_section_nr(pfn + size); 1720 1721 if (FLAGS_HAS_NODE) 1722 zone_table[ZONETABLE_INDEX(nid, zid)] = zone; 1723 else 1724 for (; snum <= end; snum++) 1725 zone_table[ZONETABLE_INDEX(snum, zid)] = zone; 1726} 1727 1728#ifndef __HAVE_ARCH_MEMMAP_INIT 1729#define memmap_init(size, nid, zone, start_pfn) \ 1730 memmap_init_zone((size), (nid), (zone), (start_pfn)) 1731#endif 1732 1733static int __cpuinit zone_batchsize(struct zone *zone) 1734{ 1735 int batch; 1736 1737 /* 1738 * The per-cpu-pages pools are set to around 1000th of the 1739 * size of the zone. But no more than 1/2 of a meg. 1740 * 1741 * OK, so we don't know how big the cache is. So guess. 1742 */ 1743 batch = zone->present_pages / 1024; 1744 if (batch * PAGE_SIZE > 512 * 1024) 1745 batch = (512 * 1024) / PAGE_SIZE; 1746 batch /= 4; /* We effectively *= 4 below */ 1747 if (batch < 1) 1748 batch = 1; 1749 1750 /* 1751 * Clamp the batch to a 2^n - 1 value. Having a power 1752 * of 2 value was found to be more likely to have 1753 * suboptimal cache aliasing properties in some cases. 1754 * 1755 * For example if 2 tasks are alternately allocating 1756 * batches of pages, one task can end up with a lot 1757 * of pages of one half of the possible page colors 1758 * and the other with pages of the other colors. 1759 */ 1760 batch = (1 << (fls(batch + batch/2)-1)) - 1; 1761 1762 return batch; 1763} 1764 1765inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 1766{ 1767 struct per_cpu_pages *pcp; 1768 1769 memset(p, 0, sizeof(*p)); 1770 1771 pcp = &p->pcp[0]; /* hot */ 1772 pcp->count = 0; 1773 pcp->high = 6 * batch; 1774 pcp->batch = max(1UL, 1 * batch); 1775 INIT_LIST_HEAD(&pcp->list); 1776 1777 pcp = &p->pcp[1]; /* cold*/ 1778 pcp->count = 0; 1779 pcp->high = 2 * batch; 1780 pcp->batch = max(1UL, batch/2); 1781 INIT_LIST_HEAD(&pcp->list); 1782} 1783 1784/* 1785 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist 1786 * to the value high for the pageset p. 1787 */ 1788 1789static void setup_pagelist_highmark(struct per_cpu_pageset *p, 1790 unsigned long high) 1791{ 1792 struct per_cpu_pages *pcp; 1793 1794 pcp = &p->pcp[0]; /* hot list */ 1795 pcp->high = high; 1796 pcp->batch = max(1UL, high/4); 1797 if ((high/4) > (PAGE_SHIFT * 8)) 1798 pcp->batch = PAGE_SHIFT * 8; 1799} 1800 1801 1802#ifdef CONFIG_NUMA 1803/* 1804 * Boot pageset table. One per cpu which is going to be used for all 1805 * zones and all nodes. The parameters will be set in such a way 1806 * that an item put on a list will immediately be handed over to 1807 * the buddy list. This is safe since pageset manipulation is done 1808 * with interrupts disabled. 1809 * 1810 * Some NUMA counter updates may also be caught by the boot pagesets. 1811 * 1812 * The boot_pagesets must be kept even after bootup is complete for 1813 * unused processors and/or zones. They do play a role for bootstrapping 1814 * hotplugged processors. 1815 * 1816 * zoneinfo_show() and maybe other functions do 1817 * not check if the processor is online before following the pageset pointer. 1818 * Other parts of the kernel may not check if the zone is available. 1819 */ 1820static struct per_cpu_pageset boot_pageset[NR_CPUS]; 1821 1822/* 1823 * Dynamically allocate memory for the 1824 * per cpu pageset array in struct zone. 1825 */ 1826static int __cpuinit process_zones(int cpu) 1827{ 1828 struct zone *zone, *dzone; 1829 1830 for_each_zone(zone) { 1831 1832 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset), 1833 GFP_KERNEL, cpu_to_node(cpu)); 1834 if (!zone_pcp(zone, cpu)) 1835 goto bad; 1836 1837 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone)); 1838 1839 if (percpu_pagelist_fraction) 1840 setup_pagelist_highmark(zone_pcp(zone, cpu), 1841 (zone->present_pages / percpu_pagelist_fraction)); 1842 } 1843 1844 return 0; 1845bad: 1846 for_each_zone(dzone) { 1847 if (dzone == zone) 1848 break; 1849 kfree(zone_pcp(dzone, cpu)); 1850 zone_pcp(dzone, cpu) = NULL; 1851 } 1852 return -ENOMEM; 1853} 1854 1855static inline void free_zone_pagesets(int cpu) 1856{ 1857 struct zone *zone; 1858 1859 for_each_zone(zone) { 1860 struct per_cpu_pageset *pset = zone_pcp(zone, cpu); 1861 1862 /* Free per_cpu_pageset if it is slab allocated */ 1863 if (pset != &boot_pageset[cpu]) 1864 kfree(pset); 1865 zone_pcp(zone, cpu) = NULL; 1866 } 1867} 1868 1869static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb, 1870 unsigned long action, 1871 void *hcpu) 1872{ 1873 int cpu = (long)hcpu; 1874 int ret = NOTIFY_OK; 1875 1876 switch (action) { 1877 case CPU_UP_PREPARE: 1878 if (process_zones(cpu)) 1879 ret = NOTIFY_BAD; 1880 break; 1881 case CPU_UP_CANCELED: 1882 case CPU_DEAD: 1883 free_zone_pagesets(cpu); 1884 break; 1885 default: 1886 break; 1887 } 1888 return ret; 1889} 1890 1891static struct notifier_block __cpuinitdata pageset_notifier = 1892 { &pageset_cpuup_callback, NULL, 0 }; 1893 1894void __init setup_per_cpu_pageset(void) 1895{ 1896 int err; 1897 1898 /* Initialize per_cpu_pageset for cpu 0. 1899 * A cpuup callback will do this for every cpu 1900 * as it comes online 1901 */ 1902 err = process_zones(smp_processor_id()); 1903 BUG_ON(err); 1904 register_cpu_notifier(&pageset_notifier); 1905} 1906 1907#endif 1908 1909static __meminit 1910int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 1911{ 1912 int i; 1913 struct pglist_data *pgdat = zone->zone_pgdat; 1914 size_t alloc_size; 1915 1916 /* 1917 * The per-page waitqueue mechanism uses hashed waitqueues 1918 * per zone. 1919 */ 1920 zone->wait_table_hash_nr_entries = 1921 wait_table_hash_nr_entries(zone_size_pages); 1922 zone->wait_table_bits = 1923 wait_table_bits(zone->wait_table_hash_nr_entries); 1924 alloc_size = zone->wait_table_hash_nr_entries 1925 * sizeof(wait_queue_head_t); 1926 1927 if (system_state == SYSTEM_BOOTING) { 1928 zone->wait_table = (wait_queue_head_t *) 1929 alloc_bootmem_node(pgdat, alloc_size); 1930 } else { 1931 /* 1932 * This case means that a zone whose size was 0 gets new memory 1933 * via memory hot-add. 1934 * But it may be the case that a new node was hot-added. In 1935 * this case vmalloc() will not be able to use this new node's 1936 * memory - this wait_table must be initialized to use this new 1937 * node itself as well. 1938 * To use this new node's memory, further consideration will be 1939 * necessary. 1940 */ 1941 zone->wait_table = (wait_queue_head_t *)vmalloc(alloc_size); 1942 } 1943 if (!zone->wait_table) 1944 return -ENOMEM; 1945 1946 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i) 1947 init_waitqueue_head(zone->wait_table + i); 1948 1949 return 0; 1950} 1951 1952static __meminit void zone_pcp_init(struct zone *zone) 1953{ 1954 int cpu; 1955 unsigned long batch = zone_batchsize(zone); 1956 1957 for (cpu = 0; cpu < NR_CPUS; cpu++) { 1958#ifdef CONFIG_NUMA 1959 /* Early boot. Slab allocator not functional yet */ 1960 zone_pcp(zone, cpu) = &boot_pageset[cpu]; 1961 setup_pageset(&boot_pageset[cpu],0); 1962#else 1963 setup_pageset(zone_pcp(zone,cpu), batch); 1964#endif 1965 } 1966 if (zone->present_pages) 1967 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", 1968 zone->name, zone->present_pages, batch); 1969} 1970 1971__meminit int init_currently_empty_zone(struct zone *zone, 1972 unsigned long zone_start_pfn, 1973 unsigned long size) 1974{ 1975 struct pglist_data *pgdat = zone->zone_pgdat; 1976 int ret; 1977 ret = zone_wait_table_init(zone, size); 1978 if (ret) 1979 return ret; 1980 pgdat->nr_zones = zone_idx(zone) + 1; 1981 1982 zone->zone_start_pfn = zone_start_pfn; 1983 1984 memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn); 1985 1986 zone_init_free_lists(pgdat, zone, zone->spanned_pages); 1987 1988 return 0; 1989} 1990 1991#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 1992/* 1993 * Basic iterator support. Return the first range of PFNs for a node 1994 * Note: nid == MAX_NUMNODES returns first region regardless of node 1995 */ 1996static int __init first_active_region_index_in_nid(int nid) 1997{ 1998 int i; 1999 2000 for (i = 0; i < nr_nodemap_entries; i++) 2001 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid) 2002 return i; 2003 2004 return -1; 2005} 2006 2007/* 2008 * Basic iterator support. Return the next active range of PFNs for a node 2009 * Note: nid == MAX_NUMNODES returns next region regardles of node 2010 */ 2011static int __init next_active_region_index_in_nid(int index, int nid) 2012{ 2013 for (index = index + 1; index < nr_nodemap_entries; index++) 2014 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid) 2015 return index; 2016 2017 return -1; 2018} 2019 2020#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID 2021/* 2022 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. 2023 * Architectures may implement their own version but if add_active_range() 2024 * was used and there are no special requirements, this is a convenient 2025 * alternative 2026 */ 2027int __init early_pfn_to_nid(unsigned long pfn) 2028{ 2029 int i; 2030 2031 for (i = 0; i < nr_nodemap_entries; i++) { 2032 unsigned long start_pfn = early_node_map[i].start_pfn; 2033 unsigned long end_pfn = early_node_map[i].end_pfn; 2034 2035 if (start_pfn <= pfn && pfn < end_pfn) 2036 return early_node_map[i].nid; 2037 } 2038 2039 return 0; 2040} 2041#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ 2042 2043/* Basic iterator support to walk early_node_map[] */ 2044#define for_each_active_range_index_in_nid(i, nid) \ 2045 for (i = first_active_region_index_in_nid(nid); i != -1; \ 2046 i = next_active_region_index_in_nid(i, nid)) 2047 2048/** 2049 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range 2050 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed 2051 * @max_low_pfn: The highest PFN that till be passed to free_bootmem_node 2052 * 2053 * If an architecture guarantees that all ranges registered with 2054 * add_active_ranges() contain no holes and may be freed, this 2055 * this function may be used instead of calling free_bootmem() manually. 2056 */ 2057void __init free_bootmem_with_active_regions(int nid, 2058 unsigned long max_low_pfn) 2059{ 2060 int i; 2061 2062 for_each_active_range_index_in_nid(i, nid) { 2063 unsigned long size_pages = 0; 2064 unsigned long end_pfn = early_node_map[i].end_pfn; 2065 2066 if (early_node_map[i].start_pfn >= max_low_pfn) 2067 continue; 2068 2069 if (end_pfn > max_low_pfn) 2070 end_pfn = max_low_pfn; 2071 2072 size_pages = end_pfn - early_node_map[i].start_pfn; 2073 free_bootmem_node(NODE_DATA(early_node_map[i].nid), 2074 PFN_PHYS(early_node_map[i].start_pfn), 2075 size_pages << PAGE_SHIFT); 2076 } 2077} 2078 2079/** 2080 * sparse_memory_present_with_active_regions - Call memory_present for each active range 2081 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used 2082 * 2083 * If an architecture guarantees that all ranges registered with 2084 * add_active_ranges() contain no holes and may be freed, this 2085 * this function may be used instead of calling memory_present() manually. 2086 */ 2087void __init sparse_memory_present_with_active_regions(int nid) 2088{ 2089 int i; 2090 2091 for_each_active_range_index_in_nid(i, nid) 2092 memory_present(early_node_map[i].nid, 2093 early_node_map[i].start_pfn, 2094 early_node_map[i].end_pfn); 2095} 2096 2097/** 2098 * get_pfn_range_for_nid - Return the start and end page frames for a node 2099 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned 2100 * @start_pfn: Passed by reference. On return, it will have the node start_pfn 2101 * @end_pfn: Passed by reference. On return, it will have the node end_pfn 2102 * 2103 * It returns the start and end page frame of a node based on information 2104 * provided by an arch calling add_active_range(). If called for a node 2105 * with no available memory, a warning is printed and the start and end 2106 * PFNs will be 0 2107 */ 2108void __init get_pfn_range_for_nid(unsigned int nid, 2109 unsigned long *start_pfn, unsigned long *end_pfn) 2110{ 2111 int i; 2112 *start_pfn = -1UL; 2113 *end_pfn = 0; 2114 2115 for_each_active_range_index_in_nid(i, nid) { 2116 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn); 2117 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn); 2118 } 2119 2120 if (*start_pfn == -1UL) { 2121 printk(KERN_WARNING "Node %u active with no memory\n", nid); 2122 *start_pfn = 0; 2123 } 2124} 2125 2126/* 2127 * Return the number of pages a zone spans in a node, including holes 2128 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() 2129 */ 2130unsigned long __init zone_spanned_pages_in_node(int nid, 2131 unsigned long zone_type, 2132 unsigned long *ignored) 2133{ 2134 unsigned long node_start_pfn, node_end_pfn; 2135 unsigned long zone_start_pfn, zone_end_pfn; 2136 2137 /* Get the start and end of the node and zone */ 2138 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 2139 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; 2140 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; 2141 2142 /* Check that this node has pages within the zone's required range */ 2143 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) 2144 return 0; 2145 2146 /* Move the zone boundaries inside the node if necessary */ 2147 zone_end_pfn = min(zone_end_pfn, node_end_pfn); 2148 zone_start_pfn = max(zone_start_pfn, node_start_pfn); 2149 2150 /* Return the spanned pages */ 2151 return zone_end_pfn - zone_start_pfn; 2152} 2153 2154/* 2155 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, 2156 * then all holes in the requested range will be accounted for 2157 */ 2158unsigned long __init __absent_pages_in_range(int nid, 2159 unsigned long range_start_pfn, 2160 unsigned long range_end_pfn) 2161{ 2162 int i = 0; 2163 unsigned long prev_end_pfn = 0, hole_pages = 0; 2164 unsigned long start_pfn; 2165 2166 /* Find the end_pfn of the first active range of pfns in the node */ 2167 i = first_active_region_index_in_nid(nid); 2168 if (i == -1) 2169 return 0; 2170 2171 prev_end_pfn = early_node_map[i].start_pfn; 2172 2173 /* Find all holes for the zone within the node */ 2174 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) { 2175 2176 /* No need to continue if prev_end_pfn is outside the zone */ 2177 if (prev_end_pfn >= range_end_pfn) 2178 break; 2179 2180 /* Make sure the end of the zone is not within the hole */ 2181 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 2182 prev_end_pfn = max(prev_end_pfn, range_start_pfn); 2183 2184 /* Update the hole size cound and move on */ 2185 if (start_pfn > range_start_pfn) { 2186 BUG_ON(prev_end_pfn > start_pfn); 2187 hole_pages += start_pfn - prev_end_pfn; 2188 } 2189 prev_end_pfn = early_node_map[i].end_pfn; 2190 } 2191 2192 return hole_pages; 2193} 2194 2195/** 2196 * absent_pages_in_range - Return number of page frames in holes within a range 2197 * @start_pfn: The start PFN to start searching for holes 2198 * @end_pfn: The end PFN to stop searching for holes 2199 * 2200 * It returns the number of pages frames in memory holes within a range 2201 */ 2202unsigned long __init absent_pages_in_range(unsigned long start_pfn, 2203 unsigned long end_pfn) 2204{ 2205 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); 2206} 2207 2208/* Return the number of page frames in holes in a zone on a node */ 2209unsigned long __init zone_absent_pages_in_node(int nid, 2210 unsigned long zone_type, 2211 unsigned long *ignored) 2212{ 2213 return __absent_pages_in_range(nid, 2214 arch_zone_lowest_possible_pfn[zone_type], 2215 arch_zone_highest_possible_pfn[zone_type]); 2216} 2217 2218/* Return the zone index a PFN is in */ 2219int memmap_zone_idx(struct page *lmem_map) 2220{ 2221 int i; 2222 unsigned long phys_addr = virt_to_phys(lmem_map); 2223 unsigned long pfn = phys_addr >> PAGE_SHIFT; 2224 2225 for (i = 0; i < MAX_NR_ZONES; i++) 2226 if (pfn < arch_zone_highest_possible_pfn[i]) 2227 break; 2228 2229 return i; 2230} 2231#else 2232static inline unsigned long zone_spanned_pages_in_node(int nid, 2233 unsigned long zone_type, 2234 unsigned long *zones_size) 2235{ 2236 return zones_size[zone_type]; 2237} 2238 2239static inline unsigned long zone_absent_pages_in_node(int nid, 2240 unsigned long zone_type, 2241 unsigned long *zholes_size) 2242{ 2243 if (!zholes_size) 2244 return 0; 2245 2246 return zholes_size[zone_type]; 2247} 2248 2249static inline int memmap_zone_idx(struct page *lmem_map) 2250{ 2251 return MAX_NR_ZONES; 2252} 2253#endif 2254 2255static void __init calculate_node_totalpages(struct pglist_data *pgdat, 2256 unsigned long *zones_size, unsigned long *zholes_size) 2257{ 2258 unsigned long realtotalpages, totalpages = 0; 2259 enum zone_type i; 2260 2261 for (i = 0; i < MAX_NR_ZONES; i++) 2262 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i, 2263 zones_size); 2264 pgdat->node_spanned_pages = totalpages; 2265 2266 realtotalpages = totalpages; 2267 for (i = 0; i < MAX_NR_ZONES; i++) 2268 realtotalpages -= 2269 zone_absent_pages_in_node(pgdat->node_id, i, 2270 zholes_size); 2271 pgdat->node_present_pages = realtotalpages; 2272 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, 2273 realtotalpages); 2274} 2275 2276/* 2277 * Set up the zone data structures: 2278 * - mark all pages reserved 2279 * - mark all memory queues empty 2280 * - clear the memory bitmaps 2281 */ 2282static void __meminit free_area_init_core(struct pglist_data *pgdat, 2283 unsigned long *zones_size, unsigned long *zholes_size) 2284{ 2285 enum zone_type j; 2286 int nid = pgdat->node_id; 2287 unsigned long zone_start_pfn = pgdat->node_start_pfn; 2288 int ret; 2289 2290 pgdat_resize_init(pgdat); 2291 pgdat->nr_zones = 0; 2292 init_waitqueue_head(&pgdat->kswapd_wait); 2293 pgdat->kswapd_max_order = 0; 2294 2295 for (j = 0; j < MAX_NR_ZONES; j++) { 2296 struct zone *zone = pgdat->node_zones + j; 2297 unsigned long size, realsize, memmap_pages; 2298 2299 size = zone_spanned_pages_in_node(nid, j, zones_size); 2300 realsize = size - zone_absent_pages_in_node(nid, j, 2301 zholes_size); 2302 2303 /* 2304 * Adjust realsize so that it accounts for how much memory 2305 * is used by this zone for memmap. This affects the watermark 2306 * and per-cpu initialisations 2307 */ 2308 memmap_pages = (size * sizeof(struct page)) >> PAGE_SHIFT; 2309 if (realsize >= memmap_pages) { 2310 realsize -= memmap_pages; 2311 printk(KERN_DEBUG 2312 " %s zone: %lu pages used for memmap\n", 2313 zone_names[j], memmap_pages); 2314 } else 2315 printk(KERN_WARNING 2316 " %s zone: %lu pages exceeds realsize %lu\n", 2317 zone_names[j], memmap_pages, realsize); 2318 2319 /* Account for reserved DMA pages */ 2320 if (j == ZONE_DMA && realsize > dma_reserve) { 2321 realsize -= dma_reserve; 2322 printk(KERN_DEBUG " DMA zone: %lu pages reserved\n", 2323 dma_reserve); 2324 } 2325 2326 if (!is_highmem_idx(j)) 2327 nr_kernel_pages += realsize; 2328 nr_all_pages += realsize; 2329 2330 zone->spanned_pages = size; 2331 zone->present_pages = realsize; 2332#ifdef CONFIG_NUMA 2333 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio) 2334 / 100; 2335 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100; 2336#endif 2337 zone->name = zone_names[j]; 2338 spin_lock_init(&zone->lock); 2339 spin_lock_init(&zone->lru_lock); 2340 zone_seqlock_init(zone); 2341 zone->zone_pgdat = pgdat; 2342 zone->free_pages = 0; 2343 2344 zone->temp_priority = zone->prev_priority = DEF_PRIORITY; 2345 2346 zone_pcp_init(zone); 2347 INIT_LIST_HEAD(&zone->active_list); 2348 INIT_LIST_HEAD(&zone->inactive_list); 2349 zone->nr_scan_active = 0; 2350 zone->nr_scan_inactive = 0; 2351 zone->nr_active = 0; 2352 zone->nr_inactive = 0; 2353 zap_zone_vm_stats(zone); 2354 atomic_set(&zone->reclaim_in_progress, 0); 2355 if (!size) 2356 continue; 2357 2358 zonetable_add(zone, nid, j, zone_start_pfn, size); 2359 ret = init_currently_empty_zone(zone, zone_start_pfn, size); 2360 BUG_ON(ret); 2361 zone_start_pfn += size; 2362 } 2363} 2364 2365static void __init alloc_node_mem_map(struct pglist_data *pgdat) 2366{ 2367 /* Skip empty nodes */ 2368 if (!pgdat->node_spanned_pages) 2369 return; 2370 2371#ifdef CONFIG_FLAT_NODE_MEM_MAP 2372 /* ia64 gets its own node_mem_map, before this, without bootmem */ 2373 if (!pgdat->node_mem_map) { 2374 unsigned long size, start, end; 2375 struct page *map; 2376 2377 /* 2378 * The zone's endpoints aren't required to be MAX_ORDER 2379 * aligned but the node_mem_map endpoints must be in order 2380 * for the buddy allocator to function correctly. 2381 */ 2382 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); 2383 end = pgdat->node_start_pfn + pgdat->node_spanned_pages; 2384 end = ALIGN(end, MAX_ORDER_NR_PAGES); 2385 size = (end - start) * sizeof(struct page); 2386 map = alloc_remap(pgdat->node_id, size); 2387 if (!map) 2388 map = alloc_bootmem_node(pgdat, size); 2389 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); 2390 } 2391#ifdef CONFIG_FLATMEM 2392 /* 2393 * With no DISCONTIG, the global mem_map is just set as node 0's 2394 */ 2395 if (pgdat == NODE_DATA(0)) { 2396 mem_map = NODE_DATA(0)->node_mem_map; 2397#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 2398 if (page_to_pfn(mem_map) != pgdat->node_start_pfn) 2399 mem_map -= pgdat->node_start_pfn; 2400#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 2401 } 2402#endif 2403#endif /* CONFIG_FLAT_NODE_MEM_MAP */ 2404} 2405 2406void __meminit free_area_init_node(int nid, struct pglist_data *pgdat, 2407 unsigned long *zones_size, unsigned long node_start_pfn, 2408 unsigned long *zholes_size) 2409{ 2410 pgdat->node_id = nid; 2411 pgdat->node_start_pfn = node_start_pfn; 2412 calculate_node_totalpages(pgdat, zones_size, zholes_size); 2413 2414 alloc_node_mem_map(pgdat); 2415 2416 free_area_init_core(pgdat, zones_size, zholes_size); 2417} 2418 2419#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 2420/** 2421 * add_active_range - Register a range of PFNs backed by physical memory 2422 * @nid: The node ID the range resides on 2423 * @start_pfn: The start PFN of the available physical memory 2424 * @end_pfn: The end PFN of the available physical memory 2425 * 2426 * These ranges are stored in an early_node_map[] and later used by 2427 * free_area_init_nodes() to calculate zone sizes and holes. If the 2428 * range spans a memory hole, it is up to the architecture to ensure 2429 * the memory is not freed by the bootmem allocator. If possible 2430 * the range being registered will be merged with existing ranges. 2431 */ 2432void __init add_active_range(unsigned int nid, unsigned long start_pfn, 2433 unsigned long end_pfn) 2434{ 2435 int i; 2436 2437 printk(KERN_DEBUG "Entering add_active_range(%d, %lu, %lu) " 2438 "%d entries of %d used\n", 2439 nid, start_pfn, end_pfn, 2440 nr_nodemap_entries, MAX_ACTIVE_REGIONS); 2441 2442 /* Merge with existing active regions if possible */ 2443 for (i = 0; i < nr_nodemap_entries; i++) { 2444 if (early_node_map[i].nid != nid) 2445 continue; 2446 2447 /* Skip if an existing region covers this new one */ 2448 if (start_pfn >= early_node_map[i].start_pfn && 2449 end_pfn <= early_node_map[i].end_pfn) 2450 return; 2451 2452 /* Merge forward if suitable */ 2453 if (start_pfn <= early_node_map[i].end_pfn && 2454 end_pfn > early_node_map[i].end_pfn) { 2455 early_node_map[i].end_pfn = end_pfn; 2456 return; 2457 } 2458 2459 /* Merge backward if suitable */ 2460 if (start_pfn < early_node_map[i].end_pfn && 2461 end_pfn >= early_node_map[i].start_pfn) { 2462 early_node_map[i].start_pfn = start_pfn; 2463 return; 2464 } 2465 } 2466 2467 /* Check that early_node_map is large enough */ 2468 if (i >= MAX_ACTIVE_REGIONS) { 2469 printk(KERN_CRIT "More than %d memory regions, truncating\n", 2470 MAX_ACTIVE_REGIONS); 2471 return; 2472 } 2473 2474 early_node_map[i].nid = nid; 2475 early_node_map[i].start_pfn = start_pfn; 2476 early_node_map[i].end_pfn = end_pfn; 2477 nr_nodemap_entries = i + 1; 2478} 2479 2480/** 2481 * shrink_active_range - Shrink an existing registered range of PFNs 2482 * @nid: The node id the range is on that should be shrunk 2483 * @old_end_pfn: The old end PFN of the range 2484 * @new_end_pfn: The new PFN of the range 2485 * 2486 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node. 2487 * The map is kept at the end physical page range that has already been 2488 * registered with add_active_range(). This function allows an arch to shrink 2489 * an existing registered range. 2490 */ 2491void __init shrink_active_range(unsigned int nid, unsigned long old_end_pfn, 2492 unsigned long new_end_pfn) 2493{ 2494 int i; 2495 2496 /* Find the old active region end and shrink */ 2497 for_each_active_range_index_in_nid(i, nid) 2498 if (early_node_map[i].end_pfn == old_end_pfn) { 2499 early_node_map[i].end_pfn = new_end_pfn; 2500 break; 2501 } 2502} 2503 2504/** 2505 * remove_all_active_ranges - Remove all currently registered regions 2506 * During discovery, it may be found that a table like SRAT is invalid 2507 * and an alternative discovery method must be used. This function removes 2508 * all currently registered regions. 2509 */ 2510void __init remove_all_active_ranges() 2511{ 2512 memset(early_node_map, 0, sizeof(early_node_map)); 2513 nr_nodemap_entries = 0; 2514} 2515 2516/* Compare two active node_active_regions */ 2517static int __init cmp_node_active_region(const void *a, const void *b) 2518{ 2519 struct node_active_region *arange = (struct node_active_region *)a; 2520 struct node_active_region *brange = (struct node_active_region *)b; 2521 2522 /* Done this way to avoid overflows */ 2523 if (arange->start_pfn > brange->start_pfn) 2524 return 1; 2525 if (arange->start_pfn < brange->start_pfn) 2526 return -1; 2527 2528 return 0; 2529} 2530 2531/* sort the node_map by start_pfn */ 2532static void __init sort_node_map(void) 2533{ 2534 sort(early_node_map, (size_t)nr_nodemap_entries, 2535 sizeof(struct node_active_region), 2536 cmp_node_active_region, NULL); 2537} 2538 2539/* Find the lowest pfn for a node. This depends on a sorted early_node_map */ 2540unsigned long __init find_min_pfn_for_node(unsigned long nid) 2541{ 2542 int i; 2543 2544 /* Assuming a sorted map, the first range found has the starting pfn */ 2545 for_each_active_range_index_in_nid(i, nid) 2546 return early_node_map[i].start_pfn; 2547 2548 printk(KERN_WARNING "Could not find start_pfn for node %lu\n", nid); 2549 return 0; 2550} 2551 2552/** 2553 * find_min_pfn_with_active_regions - Find the minimum PFN registered 2554 * 2555 * It returns the minimum PFN based on information provided via 2556 * add_active_range() 2557 */ 2558unsigned long __init find_min_pfn_with_active_regions(void) 2559{ 2560 return find_min_pfn_for_node(MAX_NUMNODES); 2561} 2562 2563/** 2564 * find_max_pfn_with_active_regions - Find the maximum PFN registered 2565 * 2566 * It returns the maximum PFN based on information provided via 2567 * add_active_range() 2568 */ 2569unsigned long __init find_max_pfn_with_active_regions(void) 2570{ 2571 int i; 2572 unsigned long max_pfn = 0; 2573 2574 for (i = 0; i < nr_nodemap_entries; i++) 2575 max_pfn = max(max_pfn, early_node_map[i].end_pfn); 2576 2577 return max_pfn; 2578} 2579 2580/** 2581 * free_area_init_nodes - Initialise all pg_data_t and zone data 2582 * @arch_max_dma_pfn: The maximum PFN usable for ZONE_DMA 2583 * @arch_max_dma32_pfn: The maximum PFN usable for ZONE_DMA32 2584 * @arch_max_low_pfn: The maximum PFN usable for ZONE_NORMAL 2585 * @arch_max_high_pfn: The maximum PFN usable for ZONE_HIGHMEM 2586 * 2587 * This will call free_area_init_node() for each active node in the system. 2588 * Using the page ranges provided by add_active_range(), the size of each 2589 * zone in each node and their holes is calculated. If the maximum PFN 2590 * between two adjacent zones match, it is assumed that the zone is empty. 2591 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed 2592 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone 2593 * starts where the previous one ended. For example, ZONE_DMA32 starts 2594 * at arch_max_dma_pfn. 2595 */ 2596void __init free_area_init_nodes(unsigned long *max_zone_pfn) 2597{ 2598 unsigned long nid; 2599 enum zone_type i; 2600 2601 /* Record where the zone boundaries are */ 2602 memset(arch_zone_lowest_possible_pfn, 0, 2603 sizeof(arch_zone_lowest_possible_pfn)); 2604 memset(arch_zone_highest_possible_pfn, 0, 2605 sizeof(arch_zone_highest_possible_pfn)); 2606 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); 2607 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; 2608 for (i = 1; i < MAX_NR_ZONES; i++) { 2609 arch_zone_lowest_possible_pfn[i] = 2610 arch_zone_highest_possible_pfn[i-1]; 2611 arch_zone_highest_possible_pfn[i] = 2612 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); 2613 } 2614 2615 /* Regions in the early_node_map can be in any order */ 2616 sort_node_map(); 2617 2618 /* Print out the zone ranges */ 2619 printk("Zone PFN ranges:\n"); 2620 for (i = 0; i < MAX_NR_ZONES; i++) 2621 printk(" %-8s %8lu -> %8lu\n", 2622 zone_names[i], 2623 arch_zone_lowest_possible_pfn[i], 2624 arch_zone_highest_possible_pfn[i]); 2625 2626 /* Print out the early_node_map[] */ 2627 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries); 2628 for (i = 0; i < nr_nodemap_entries; i++) 2629 printk(" %3d: %8lu -> %8lu\n", early_node_map[i].nid, 2630 early_node_map[i].start_pfn, 2631 early_node_map[i].end_pfn); 2632 2633 /* Initialise every node */ 2634 for_each_online_node(nid) { 2635 pg_data_t *pgdat = NODE_DATA(nid); 2636 free_area_init_node(nid, pgdat, NULL, 2637 find_min_pfn_for_node(nid), NULL); 2638 } 2639} 2640#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 2641 2642/** 2643 * set_dma_reserve - Account the specified number of pages reserved in ZONE_DMA 2644 * @new_dma_reserve - The number of pages to mark reserved 2645 * 2646 * The per-cpu batchsize and zone watermarks are determined by present_pages. 2647 * In the DMA zone, a significant percentage may be consumed by kernel image 2648 * and other unfreeable allocations which can skew the watermarks badly. This 2649 * function may optionally be used to account for unfreeable pages in 2650 * ZONE_DMA. The effect will be lower watermarks and smaller per-cpu batchsize 2651 */ 2652void __init set_dma_reserve(unsigned long new_dma_reserve) 2653{ 2654 dma_reserve = new_dma_reserve; 2655} 2656 2657#ifndef CONFIG_NEED_MULTIPLE_NODES 2658static bootmem_data_t contig_bootmem_data; 2659struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data }; 2660 2661EXPORT_SYMBOL(contig_page_data); 2662#endif 2663 2664void __init free_area_init(unsigned long *zones_size) 2665{ 2666 free_area_init_node(0, NODE_DATA(0), zones_size, 2667 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 2668} 2669 2670#ifdef CONFIG_HOTPLUG_CPU 2671static int page_alloc_cpu_notify(struct notifier_block *self, 2672 unsigned long action, void *hcpu) 2673{ 2674 int cpu = (unsigned long)hcpu; 2675 2676 if (action == CPU_DEAD) { 2677 local_irq_disable(); 2678 __drain_pages(cpu); 2679 vm_events_fold_cpu(cpu); 2680 local_irq_enable(); 2681 refresh_cpu_vm_stats(cpu); 2682 } 2683 return NOTIFY_OK; 2684} 2685#endif /* CONFIG_HOTPLUG_CPU */ 2686 2687void __init page_alloc_init(void) 2688{ 2689 hotcpu_notifier(page_alloc_cpu_notify, 0); 2690} 2691 2692/* 2693 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio 2694 * or min_free_kbytes changes. 2695 */ 2696static void calculate_totalreserve_pages(void) 2697{ 2698 struct pglist_data *pgdat; 2699 unsigned long reserve_pages = 0; 2700 enum zone_type i, j; 2701 2702 for_each_online_pgdat(pgdat) { 2703 for (i = 0; i < MAX_NR_ZONES; i++) { 2704 struct zone *zone = pgdat->node_zones + i; 2705 unsigned long max = 0; 2706 2707 /* Find valid and maximum lowmem_reserve in the zone */ 2708 for (j = i; j < MAX_NR_ZONES; j++) { 2709 if (zone->lowmem_reserve[j] > max) 2710 max = zone->lowmem_reserve[j]; 2711 } 2712 2713 /* we treat pages_high as reserved pages. */ 2714 max += zone->pages_high; 2715 2716 if (max > zone->present_pages) 2717 max = zone->present_pages; 2718 reserve_pages += max; 2719 } 2720 } 2721 totalreserve_pages = reserve_pages; 2722} 2723 2724/* 2725 * setup_per_zone_lowmem_reserve - called whenever 2726 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 2727 * has a correct pages reserved value, so an adequate number of 2728 * pages are left in the zone after a successful __alloc_pages(). 2729 */ 2730static void setup_per_zone_lowmem_reserve(void) 2731{ 2732 struct pglist_data *pgdat; 2733 enum zone_type j, idx; 2734 2735 for_each_online_pgdat(pgdat) { 2736 for (j = 0; j < MAX_NR_ZONES; j++) { 2737 struct zone *zone = pgdat->node_zones + j; 2738 unsigned long present_pages = zone->present_pages; 2739 2740 zone->lowmem_reserve[j] = 0; 2741 2742 idx = j; 2743 while (idx) { 2744 struct zone *lower_zone; 2745 2746 idx--; 2747 2748 if (sysctl_lowmem_reserve_ratio[idx] < 1) 2749 sysctl_lowmem_reserve_ratio[idx] = 1; 2750 2751 lower_zone = pgdat->node_zones + idx; 2752 lower_zone->lowmem_reserve[j] = present_pages / 2753 sysctl_lowmem_reserve_ratio[idx]; 2754 present_pages += lower_zone->present_pages; 2755 } 2756 } 2757 } 2758 2759 /* update totalreserve_pages */ 2760 calculate_totalreserve_pages(); 2761} 2762 2763/* 2764 * setup_per_zone_pages_min - called when min_free_kbytes changes. Ensures 2765 * that the pages_{min,low,high} values for each zone are set correctly 2766 * with respect to min_free_kbytes. 2767 */ 2768void setup_per_zone_pages_min(void) 2769{ 2770 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 2771 unsigned long lowmem_pages = 0; 2772 struct zone *zone; 2773 unsigned long flags; 2774 2775 /* Calculate total number of !ZONE_HIGHMEM pages */ 2776 for_each_zone(zone) { 2777 if (!is_highmem(zone)) 2778 lowmem_pages += zone->present_pages; 2779 } 2780 2781 for_each_zone(zone) { 2782 u64 tmp; 2783 2784 spin_lock_irqsave(&zone->lru_lock, flags); 2785 tmp = (u64)pages_min * zone->present_pages; 2786 do_div(tmp, lowmem_pages); 2787 if (is_highmem(zone)) { 2788 /* 2789 * __GFP_HIGH and PF_MEMALLOC allocations usually don't 2790 * need highmem pages, so cap pages_min to a small 2791 * value here. 2792 * 2793 * The (pages_high-pages_low) and (pages_low-pages_min) 2794 * deltas controls asynch page reclaim, and so should 2795 * not be capped for highmem. 2796 */ 2797 int min_pages; 2798 2799 min_pages = zone->present_pages / 1024; 2800 if (min_pages < SWAP_CLUSTER_MAX) 2801 min_pages = SWAP_CLUSTER_MAX; 2802 if (min_pages > 128) 2803 min_pages = 128; 2804 zone->pages_min = min_pages; 2805 } else { 2806 /* 2807 * If it's a lowmem zone, reserve a number of pages 2808 * proportionate to the zone's size. 2809 */ 2810 zone->pages_min = tmp; 2811 } 2812 2813 zone->pages_low = zone->pages_min + (tmp >> 2); 2814 zone->pages_high = zone->pages_min + (tmp >> 1); 2815 spin_unlock_irqrestore(&zone->lru_lock, flags); 2816 } 2817 2818 /* update totalreserve_pages */ 2819 calculate_totalreserve_pages(); 2820} 2821 2822/* 2823 * Initialise min_free_kbytes. 2824 * 2825 * For small machines we want it small (128k min). For large machines 2826 * we want it large (64MB max). But it is not linear, because network 2827 * bandwidth does not increase linearly with machine size. We use 2828 * 2829 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 2830 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 2831 * 2832 * which yields 2833 * 2834 * 16MB: 512k 2835 * 32MB: 724k 2836 * 64MB: 1024k 2837 * 128MB: 1448k 2838 * 256MB: 2048k 2839 * 512MB: 2896k 2840 * 1024MB: 4096k 2841 * 2048MB: 5792k 2842 * 4096MB: 8192k 2843 * 8192MB: 11584k 2844 * 16384MB: 16384k 2845 */ 2846static int __init init_per_zone_pages_min(void) 2847{ 2848 unsigned long lowmem_kbytes; 2849 2850 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 2851 2852 min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 2853 if (min_free_kbytes < 128) 2854 min_free_kbytes = 128; 2855 if (min_free_kbytes > 65536) 2856 min_free_kbytes = 65536; 2857 setup_per_zone_pages_min(); 2858 setup_per_zone_lowmem_reserve(); 2859 return 0; 2860} 2861module_init(init_per_zone_pages_min) 2862 2863/* 2864 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 2865 * that we can call two helper functions whenever min_free_kbytes 2866 * changes. 2867 */ 2868int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 2869 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 2870{ 2871 proc_dointvec(table, write, file, buffer, length, ppos); 2872 setup_per_zone_pages_min(); 2873 return 0; 2874} 2875 2876#ifdef CONFIG_NUMA 2877int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, 2878 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 2879{ 2880 struct zone *zone; 2881 int rc; 2882 2883 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 2884 if (rc) 2885 return rc; 2886 2887 for_each_zone(zone) 2888 zone->min_unmapped_pages = (zone->present_pages * 2889 sysctl_min_unmapped_ratio) / 100; 2890 return 0; 2891} 2892 2893int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write, 2894 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 2895{ 2896 struct zone *zone; 2897 int rc; 2898 2899 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 2900 if (rc) 2901 return rc; 2902 2903 for_each_zone(zone) 2904 zone->min_slab_pages = (zone->present_pages * 2905 sysctl_min_slab_ratio) / 100; 2906 return 0; 2907} 2908#endif 2909 2910/* 2911 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 2912 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 2913 * whenever sysctl_lowmem_reserve_ratio changes. 2914 * 2915 * The reserve ratio obviously has absolutely no relation with the 2916 * pages_min watermarks. The lowmem reserve ratio can only make sense 2917 * if in function of the boot time zone sizes. 2918 */ 2919int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, 2920 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 2921{ 2922 proc_dointvec_minmax(table, write, file, buffer, length, ppos); 2923 setup_per_zone_lowmem_reserve(); 2924 return 0; 2925} 2926 2927/* 2928 * percpu_pagelist_fraction - changes the pcp->high for each zone on each 2929 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist 2930 * can have before it gets flushed back to buddy allocator. 2931 */ 2932 2933int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, 2934 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 2935{ 2936 struct zone *zone; 2937 unsigned int cpu; 2938 int ret; 2939 2940 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 2941 if (!write || (ret == -EINVAL)) 2942 return ret; 2943 for_each_zone(zone) { 2944 for_each_online_cpu(cpu) { 2945 unsigned long high; 2946 high = zone->present_pages / percpu_pagelist_fraction; 2947 setup_pagelist_highmark(zone_pcp(zone, cpu), high); 2948 } 2949 } 2950 return 0; 2951} 2952 2953int hashdist = HASHDIST_DEFAULT; 2954 2955#ifdef CONFIG_NUMA 2956static int __init set_hashdist(char *str) 2957{ 2958 if (!str) 2959 return 0; 2960 hashdist = simple_strtoul(str, &str, 0); 2961 return 1; 2962} 2963__setup("hashdist=", set_hashdist); 2964#endif 2965 2966/* 2967 * allocate a large system hash table from bootmem 2968 * - it is assumed that the hash table must contain an exact power-of-2 2969 * quantity of entries 2970 * - limit is the number of hash buckets, not the total allocation size 2971 */ 2972void *__init alloc_large_system_hash(const char *tablename, 2973 unsigned long bucketsize, 2974 unsigned long numentries, 2975 int scale, 2976 int flags, 2977 unsigned int *_hash_shift, 2978 unsigned int *_hash_mask, 2979 unsigned long limit) 2980{ 2981 unsigned long long max = limit; 2982 unsigned long log2qty, size; 2983 void *table = NULL; 2984 2985 /* allow the kernel cmdline to have a say */ 2986 if (!numentries) { 2987 /* round applicable memory size up to nearest megabyte */ 2988 numentries = (flags & HASH_HIGHMEM) ? nr_all_pages : nr_kernel_pages; 2989 numentries += (1UL << (20 - PAGE_SHIFT)) - 1; 2990 numentries >>= 20 - PAGE_SHIFT; 2991 numentries <<= 20 - PAGE_SHIFT; 2992 2993 /* limit to 1 bucket per 2^scale bytes of low memory */ 2994 if (scale > PAGE_SHIFT) 2995 numentries >>= (scale - PAGE_SHIFT); 2996 else 2997 numentries <<= (PAGE_SHIFT - scale); 2998 } 2999 numentries = roundup_pow_of_two(numentries); 3000 3001 /* limit allocation size to 1/16 total memory by default */ 3002 if (max == 0) { 3003 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 3004 do_div(max, bucketsize); 3005 } 3006 3007 if (numentries > max) 3008 numentries = max; 3009 3010 log2qty = long_log2(numentries); 3011 3012 do { 3013 size = bucketsize << log2qty; 3014 if (flags & HASH_EARLY) 3015 table = alloc_bootmem(size); 3016 else if (hashdist) 3017 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 3018 else { 3019 unsigned long order; 3020 for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++) 3021 ; 3022 table = (void*) __get_free_pages(GFP_ATOMIC, order); 3023 } 3024 } while (!table && size > PAGE_SIZE && --log2qty); 3025 3026 if (!table) 3027 panic("Failed to allocate %s hash table\n", tablename); 3028 3029 printk("%s hash table entries: %d (order: %d, %lu bytes)\n", 3030 tablename, 3031 (1U << log2qty), 3032 long_log2(size) - PAGE_SHIFT, 3033 size); 3034 3035 if (_hash_shift) 3036 *_hash_shift = log2qty; 3037 if (_hash_mask) 3038 *_hash_mask = (1 << log2qty) - 1; 3039 3040 return table; 3041} 3042 3043#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE 3044struct page *pfn_to_page(unsigned long pfn) 3045{ 3046 return __pfn_to_page(pfn); 3047} 3048unsigned long page_to_pfn(struct page *page) 3049{ 3050 return __page_to_pfn(page); 3051} 3052EXPORT_SYMBOL(pfn_to_page); 3053EXPORT_SYMBOL(page_to_pfn); 3054#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */ 3055