page_alloc.c revision 6ea6e6887dad1fd44e6d5020a0fd355af4f2b6b3
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#include <linux/backing-dev.h> 43#include <linux/fault-inject.h> 44 45#include <asm/tlbflush.h> 46#include <asm/div64.h> 47#include "internal.h" 48 49/* 50 * MCD - HACK: Find somewhere to initialize this EARLY, or make this 51 * initializer cleaner 52 */ 53nodemask_t node_online_map __read_mostly = { { [0] = 1UL } }; 54EXPORT_SYMBOL(node_online_map); 55nodemask_t node_possible_map __read_mostly = NODE_MASK_ALL; 56EXPORT_SYMBOL(node_possible_map); 57unsigned long totalram_pages __read_mostly; 58unsigned long totalreserve_pages __read_mostly; 59long nr_swap_pages; 60int percpu_pagelist_fraction; 61 62static void __free_pages_ok(struct page *page, unsigned int order); 63 64/* 65 * results with 256, 32 in the lowmem_reserve sysctl: 66 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) 67 * 1G machine -> (16M dma, 784M normal, 224M high) 68 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA 69 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL 70 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA 71 * 72 * TBD: should special case ZONE_DMA32 machines here - in those we normally 73 * don't need any ZONE_NORMAL reservation 74 */ 75int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 76#ifdef CONFIG_ZONE_DMA 77 256, 78#endif 79#ifdef CONFIG_ZONE_DMA32 80 256, 81#endif 82#ifdef CONFIG_HIGHMEM 83 32 84#endif 85}; 86 87EXPORT_SYMBOL(totalram_pages); 88 89static char * const zone_names[MAX_NR_ZONES] = { 90#ifdef CONFIG_ZONE_DMA 91 "DMA", 92#endif 93#ifdef CONFIG_ZONE_DMA32 94 "DMA32", 95#endif 96 "Normal", 97#ifdef CONFIG_HIGHMEM 98 "HighMem" 99#endif 100}; 101 102int min_free_kbytes = 1024; 103 104unsigned long __meminitdata nr_kernel_pages; 105unsigned long __meminitdata nr_all_pages; 106static unsigned long __meminitdata dma_reserve; 107 108#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 109 /* 110 * MAX_ACTIVE_REGIONS determines the maxmimum number of distinct 111 * ranges of memory (RAM) that may be registered with add_active_range(). 112 * Ranges passed to add_active_range() will be merged if possible 113 * so the number of times add_active_range() can be called is 114 * related to the number of nodes and the number of holes 115 */ 116 #ifdef CONFIG_MAX_ACTIVE_REGIONS 117 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */ 118 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS 119 #else 120 #if MAX_NUMNODES >= 32 121 /* If there can be many nodes, allow up to 50 holes per node */ 122 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50) 123 #else 124 /* By default, allow up to 256 distinct regions */ 125 #define MAX_ACTIVE_REGIONS 256 126 #endif 127 #endif 128 129 static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS]; 130 static int __meminitdata nr_nodemap_entries; 131 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; 132 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; 133#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE 134 static unsigned long __meminitdata node_boundary_start_pfn[MAX_NUMNODES]; 135 static unsigned long __meminitdata node_boundary_end_pfn[MAX_NUMNODES]; 136#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */ 137#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 138 139#if MAX_NUMNODES > 1 140int nr_node_ids __read_mostly = MAX_NUMNODES; 141EXPORT_SYMBOL(nr_node_ids); 142#endif 143 144#ifdef CONFIG_DEBUG_VM 145static int page_outside_zone_boundaries(struct zone *zone, struct page *page) 146{ 147 int ret = 0; 148 unsigned seq; 149 unsigned long pfn = page_to_pfn(page); 150 151 do { 152 seq = zone_span_seqbegin(zone); 153 if (pfn >= zone->zone_start_pfn + zone->spanned_pages) 154 ret = 1; 155 else if (pfn < zone->zone_start_pfn) 156 ret = 1; 157 } while (zone_span_seqretry(zone, seq)); 158 159 return ret; 160} 161 162static int page_is_consistent(struct zone *zone, struct page *page) 163{ 164 if (!pfn_valid_within(page_to_pfn(page))) 165 return 0; 166 if (zone != page_zone(page)) 167 return 0; 168 169 return 1; 170} 171/* 172 * Temporary debugging check for pages not lying within a given zone. 173 */ 174static int bad_range(struct zone *zone, struct page *page) 175{ 176 if (page_outside_zone_boundaries(zone, page)) 177 return 1; 178 if (!page_is_consistent(zone, page)) 179 return 1; 180 181 return 0; 182} 183#else 184static inline int bad_range(struct zone *zone, struct page *page) 185{ 186 return 0; 187} 188#endif 189 190static void bad_page(struct page *page) 191{ 192 printk(KERN_EMERG "Bad page state in process '%s'\n" 193 KERN_EMERG "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n" 194 KERN_EMERG "Trying to fix it up, but a reboot is needed\n" 195 KERN_EMERG "Backtrace:\n", 196 current->comm, page, (int)(2*sizeof(unsigned long)), 197 (unsigned long)page->flags, page->mapping, 198 page_mapcount(page), page_count(page)); 199 dump_stack(); 200 page->flags &= ~(1 << PG_lru | 201 1 << PG_private | 202 1 << PG_locked | 203 1 << PG_active | 204 1 << PG_dirty | 205 1 << PG_reclaim | 206 1 << PG_slab | 207 1 << PG_swapcache | 208 1 << PG_writeback | 209 1 << PG_buddy ); 210 set_page_count(page, 0); 211 reset_page_mapcount(page); 212 page->mapping = NULL; 213 add_taint(TAINT_BAD_PAGE); 214} 215 216/* 217 * Higher-order pages are called "compound pages". They are structured thusly: 218 * 219 * The first PAGE_SIZE page is called the "head page". 220 * 221 * The remaining PAGE_SIZE pages are called "tail pages". 222 * 223 * All pages have PG_compound set. All pages have their ->private pointing at 224 * the head page (even the head page has this). 225 * 226 * The first tail page's ->lru.next holds the address of the compound page's 227 * put_page() function. Its ->lru.prev holds the order of allocation. 228 * This usage means that zero-order pages may not be compound. 229 */ 230 231static void free_compound_page(struct page *page) 232{ 233 __free_pages_ok(page, compound_order(page)); 234} 235 236static void prep_compound_page(struct page *page, unsigned long order) 237{ 238 int i; 239 int nr_pages = 1 << order; 240 241 set_compound_page_dtor(page, free_compound_page); 242 set_compound_order(page, order); 243 __SetPageHead(page); 244 for (i = 1; i < nr_pages; i++) { 245 struct page *p = page + i; 246 247 __SetPageTail(p); 248 p->first_page = page; 249 } 250} 251 252static void destroy_compound_page(struct page *page, unsigned long order) 253{ 254 int i; 255 int nr_pages = 1 << order; 256 257 if (unlikely(compound_order(page) != order)) 258 bad_page(page); 259 260 if (unlikely(!PageHead(page))) 261 bad_page(page); 262 __ClearPageHead(page); 263 for (i = 1; i < nr_pages; i++) { 264 struct page *p = page + i; 265 266 if (unlikely(!PageTail(p) | 267 (p->first_page != page))) 268 bad_page(page); 269 __ClearPageTail(p); 270 } 271} 272 273static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) 274{ 275 int i; 276 277 VM_BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM); 278 /* 279 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO 280 * and __GFP_HIGHMEM from hard or soft interrupt context. 281 */ 282 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); 283 for (i = 0; i < (1 << order); i++) 284 clear_highpage(page + i); 285} 286 287/* 288 * function for dealing with page's order in buddy system. 289 * zone->lock is already acquired when we use these. 290 * So, we don't need atomic page->flags operations here. 291 */ 292static inline unsigned long page_order(struct page *page) 293{ 294 return page_private(page); 295} 296 297static inline void set_page_order(struct page *page, int order) 298{ 299 set_page_private(page, order); 300 __SetPageBuddy(page); 301} 302 303static inline void rmv_page_order(struct page *page) 304{ 305 __ClearPageBuddy(page); 306 set_page_private(page, 0); 307} 308 309/* 310 * Locate the struct page for both the matching buddy in our 311 * pair (buddy1) and the combined O(n+1) page they form (page). 312 * 313 * 1) Any buddy B1 will have an order O twin B2 which satisfies 314 * the following equation: 315 * B2 = B1 ^ (1 << O) 316 * For example, if the starting buddy (buddy2) is #8 its order 317 * 1 buddy is #10: 318 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 319 * 320 * 2) Any buddy B will have an order O+1 parent P which 321 * satisfies the following equation: 322 * P = B & ~(1 << O) 323 * 324 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 325 */ 326static inline struct page * 327__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order) 328{ 329 unsigned long buddy_idx = page_idx ^ (1 << order); 330 331 return page + (buddy_idx - page_idx); 332} 333 334static inline unsigned long 335__find_combined_index(unsigned long page_idx, unsigned int order) 336{ 337 return (page_idx & ~(1 << order)); 338} 339 340/* 341 * This function checks whether a page is free && is the buddy 342 * we can do coalesce a page and its buddy if 343 * (a) the buddy is not in a hole && 344 * (b) the buddy is in the buddy system && 345 * (c) a page and its buddy have the same order && 346 * (d) a page and its buddy are in the same zone. 347 * 348 * For recording whether a page is in the buddy system, we use PG_buddy. 349 * Setting, clearing, and testing PG_buddy is serialized by zone->lock. 350 * 351 * For recording page's order, we use page_private(page). 352 */ 353static inline int page_is_buddy(struct page *page, struct page *buddy, 354 int order) 355{ 356 if (!pfn_valid_within(page_to_pfn(buddy))) 357 return 0; 358 359 if (page_zone_id(page) != page_zone_id(buddy)) 360 return 0; 361 362 if (PageBuddy(buddy) && page_order(buddy) == order) { 363 BUG_ON(page_count(buddy) != 0); 364 return 1; 365 } 366 return 0; 367} 368 369/* 370 * Freeing function for a buddy system allocator. 371 * 372 * The concept of a buddy system is to maintain direct-mapped table 373 * (containing bit values) for memory blocks of various "orders". 374 * The bottom level table contains the map for the smallest allocatable 375 * units of memory (here, pages), and each level above it describes 376 * pairs of units from the levels below, hence, "buddies". 377 * At a high level, all that happens here is marking the table entry 378 * at the bottom level available, and propagating the changes upward 379 * as necessary, plus some accounting needed to play nicely with other 380 * parts of the VM system. 381 * At each level, we keep a list of pages, which are heads of continuous 382 * free pages of length of (1 << order) and marked with PG_buddy. Page's 383 * order is recorded in page_private(page) field. 384 * So when we are allocating or freeing one, we can derive the state of the 385 * other. That is, if we allocate a small block, and both were 386 * free, the remainder of the region must be split into blocks. 387 * If a block is freed, and its buddy is also free, then this 388 * triggers coalescing into a block of larger size. 389 * 390 * -- wli 391 */ 392 393static inline void __free_one_page(struct page *page, 394 struct zone *zone, unsigned int order) 395{ 396 unsigned long page_idx; 397 int order_size = 1 << order; 398 399 if (unlikely(PageCompound(page))) 400 destroy_compound_page(page, order); 401 402 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); 403 404 VM_BUG_ON(page_idx & (order_size - 1)); 405 VM_BUG_ON(bad_range(zone, page)); 406 407 __mod_zone_page_state(zone, NR_FREE_PAGES, order_size); 408 while (order < MAX_ORDER-1) { 409 unsigned long combined_idx; 410 struct free_area *area; 411 struct page *buddy; 412 413 buddy = __page_find_buddy(page, page_idx, order); 414 if (!page_is_buddy(page, buddy, order)) 415 break; /* Move the buddy up one level. */ 416 417 list_del(&buddy->lru); 418 area = zone->free_area + order; 419 area->nr_free--; 420 rmv_page_order(buddy); 421 combined_idx = __find_combined_index(page_idx, order); 422 page = page + (combined_idx - page_idx); 423 page_idx = combined_idx; 424 order++; 425 } 426 set_page_order(page, order); 427 list_add(&page->lru, &zone->free_area[order].free_list); 428 zone->free_area[order].nr_free++; 429} 430 431static inline int free_pages_check(struct page *page) 432{ 433 if (unlikely(page_mapcount(page) | 434 (page->mapping != NULL) | 435 (page_count(page) != 0) | 436 (page->flags & ( 437 1 << PG_lru | 438 1 << PG_private | 439 1 << PG_locked | 440 1 << PG_active | 441 1 << PG_slab | 442 1 << PG_swapcache | 443 1 << PG_writeback | 444 1 << PG_reserved | 445 1 << PG_buddy )))) 446 bad_page(page); 447 /* 448 * PageReclaim == PageTail. It is only an error 449 * for PageReclaim to be set if PageCompound is clear. 450 */ 451 if (unlikely(!PageCompound(page) && PageReclaim(page))) 452 bad_page(page); 453 if (PageDirty(page)) 454 __ClearPageDirty(page); 455 /* 456 * For now, we report if PG_reserved was found set, but do not 457 * clear it, and do not free the page. But we shall soon need 458 * to do more, for when the ZERO_PAGE count wraps negative. 459 */ 460 return PageReserved(page); 461} 462 463/* 464 * Frees a list of pages. 465 * Assumes all pages on list are in same zone, and of same order. 466 * count is the number of pages to free. 467 * 468 * If the zone was previously in an "all pages pinned" state then look to 469 * see if this freeing clears that state. 470 * 471 * And clear the zone's pages_scanned counter, to hold off the "all pages are 472 * pinned" detection logic. 473 */ 474static void free_pages_bulk(struct zone *zone, int count, 475 struct list_head *list, int order) 476{ 477 spin_lock(&zone->lock); 478 zone->all_unreclaimable = 0; 479 zone->pages_scanned = 0; 480 while (count--) { 481 struct page *page; 482 483 VM_BUG_ON(list_empty(list)); 484 page = list_entry(list->prev, struct page, lru); 485 /* have to delete it as __free_one_page list manipulates */ 486 list_del(&page->lru); 487 __free_one_page(page, zone, order); 488 } 489 spin_unlock(&zone->lock); 490} 491 492static void free_one_page(struct zone *zone, struct page *page, int order) 493{ 494 spin_lock(&zone->lock); 495 zone->all_unreclaimable = 0; 496 zone->pages_scanned = 0; 497 __free_one_page(page, zone, order); 498 spin_unlock(&zone->lock); 499} 500 501static void __free_pages_ok(struct page *page, unsigned int order) 502{ 503 unsigned long flags; 504 int i; 505 int reserved = 0; 506 507 for (i = 0 ; i < (1 << order) ; ++i) 508 reserved += free_pages_check(page + i); 509 if (reserved) 510 return; 511 512 if (!PageHighMem(page)) 513 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order); 514 arch_free_page(page, order); 515 kernel_map_pages(page, 1 << order, 0); 516 517 local_irq_save(flags); 518 __count_vm_events(PGFREE, 1 << order); 519 free_one_page(page_zone(page), page, order); 520 local_irq_restore(flags); 521} 522 523/* 524 * permit the bootmem allocator to evade page validation on high-order frees 525 */ 526void fastcall __init __free_pages_bootmem(struct page *page, unsigned int order) 527{ 528 if (order == 0) { 529 __ClearPageReserved(page); 530 set_page_count(page, 0); 531 set_page_refcounted(page); 532 __free_page(page); 533 } else { 534 int loop; 535 536 prefetchw(page); 537 for (loop = 0; loop < BITS_PER_LONG; loop++) { 538 struct page *p = &page[loop]; 539 540 if (loop + 1 < BITS_PER_LONG) 541 prefetchw(p + 1); 542 __ClearPageReserved(p); 543 set_page_count(p, 0); 544 } 545 546 set_page_refcounted(page); 547 __free_pages(page, order); 548 } 549} 550 551 552/* 553 * The order of subdivision here is critical for the IO subsystem. 554 * Please do not alter this order without good reasons and regression 555 * testing. Specifically, as large blocks of memory are subdivided, 556 * the order in which smaller blocks are delivered depends on the order 557 * they're subdivided in this function. This is the primary factor 558 * influencing the order in which pages are delivered to the IO 559 * subsystem according to empirical testing, and this is also justified 560 * by considering the behavior of a buddy system containing a single 561 * large block of memory acted on by a series of small allocations. 562 * This behavior is a critical factor in sglist merging's success. 563 * 564 * -- wli 565 */ 566static inline void expand(struct zone *zone, struct page *page, 567 int low, int high, struct free_area *area) 568{ 569 unsigned long size = 1 << high; 570 571 while (high > low) { 572 area--; 573 high--; 574 size >>= 1; 575 VM_BUG_ON(bad_range(zone, &page[size])); 576 list_add(&page[size].lru, &area->free_list); 577 area->nr_free++; 578 set_page_order(&page[size], high); 579 } 580} 581 582/* 583 * This page is about to be returned from the page allocator 584 */ 585static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) 586{ 587 if (unlikely(page_mapcount(page) | 588 (page->mapping != NULL) | 589 (page_count(page) != 0) | 590 (page->flags & ( 591 1 << PG_lru | 592 1 << PG_private | 593 1 << PG_locked | 594 1 << PG_active | 595 1 << PG_dirty | 596 1 << PG_reclaim | 597 1 << PG_slab | 598 1 << PG_swapcache | 599 1 << PG_writeback | 600 1 << PG_reserved | 601 1 << PG_buddy )))) 602 bad_page(page); 603 604 /* 605 * For now, we report if PG_reserved was found set, but do not 606 * clear it, and do not allocate the page: as a safety net. 607 */ 608 if (PageReserved(page)) 609 return 1; 610 611 page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 612 1 << PG_referenced | 1 << PG_arch_1 | 613 1 << PG_owner_priv_1 | 1 << PG_mappedtodisk); 614 set_page_private(page, 0); 615 set_page_refcounted(page); 616 617 arch_alloc_page(page, order); 618 kernel_map_pages(page, 1 << order, 1); 619 620 if (gfp_flags & __GFP_ZERO) 621 prep_zero_page(page, order, gfp_flags); 622 623 if (order && (gfp_flags & __GFP_COMP)) 624 prep_compound_page(page, order); 625 626 return 0; 627} 628 629/* 630 * Do the hard work of removing an element from the buddy allocator. 631 * Call me with the zone->lock already held. 632 */ 633static struct page *__rmqueue(struct zone *zone, unsigned int order) 634{ 635 struct free_area * area; 636 unsigned int current_order; 637 struct page *page; 638 639 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 640 area = zone->free_area + current_order; 641 if (list_empty(&area->free_list)) 642 continue; 643 644 page = list_entry(area->free_list.next, struct page, lru); 645 list_del(&page->lru); 646 rmv_page_order(page); 647 area->nr_free--; 648 __mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order)); 649 expand(zone, page, order, current_order, area); 650 return page; 651 } 652 653 return NULL; 654} 655 656/* 657 * Obtain a specified number of elements from the buddy allocator, all under 658 * a single hold of the lock, for efficiency. Add them to the supplied list. 659 * Returns the number of new pages which were placed at *list. 660 */ 661static int rmqueue_bulk(struct zone *zone, unsigned int order, 662 unsigned long count, struct list_head *list) 663{ 664 int i; 665 666 spin_lock(&zone->lock); 667 for (i = 0; i < count; ++i) { 668 struct page *page = __rmqueue(zone, order); 669 if (unlikely(page == NULL)) 670 break; 671 list_add_tail(&page->lru, list); 672 } 673 spin_unlock(&zone->lock); 674 return i; 675} 676 677#ifdef CONFIG_NUMA 678/* 679 * Called from the vmstat counter updater to drain pagesets of this 680 * currently executing processor on remote nodes after they have 681 * expired. 682 * 683 * Note that this function must be called with the thread pinned to 684 * a single processor. 685 */ 686void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) 687{ 688 unsigned long flags; 689 int to_drain; 690 691 local_irq_save(flags); 692 if (pcp->count >= pcp->batch) 693 to_drain = pcp->batch; 694 else 695 to_drain = pcp->count; 696 free_pages_bulk(zone, to_drain, &pcp->list, 0); 697 pcp->count -= to_drain; 698 local_irq_restore(flags); 699} 700#endif 701 702static void __drain_pages(unsigned int cpu) 703{ 704 unsigned long flags; 705 struct zone *zone; 706 int i; 707 708 for_each_zone(zone) { 709 struct per_cpu_pageset *pset; 710 711 if (!populated_zone(zone)) 712 continue; 713 714 pset = zone_pcp(zone, cpu); 715 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) { 716 struct per_cpu_pages *pcp; 717 718 pcp = &pset->pcp[i]; 719 local_irq_save(flags); 720 free_pages_bulk(zone, pcp->count, &pcp->list, 0); 721 pcp->count = 0; 722 local_irq_restore(flags); 723 } 724 } 725} 726 727#ifdef CONFIG_PM 728 729void mark_free_pages(struct zone *zone) 730{ 731 unsigned long pfn, max_zone_pfn; 732 unsigned long flags; 733 int order; 734 struct list_head *curr; 735 736 if (!zone->spanned_pages) 737 return; 738 739 spin_lock_irqsave(&zone->lock, flags); 740 741 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; 742 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 743 if (pfn_valid(pfn)) { 744 struct page *page = pfn_to_page(pfn); 745 746 if (!swsusp_page_is_forbidden(page)) 747 swsusp_unset_page_free(page); 748 } 749 750 for (order = MAX_ORDER - 1; order >= 0; --order) 751 list_for_each(curr, &zone->free_area[order].free_list) { 752 unsigned long i; 753 754 pfn = page_to_pfn(list_entry(curr, struct page, lru)); 755 for (i = 0; i < (1UL << order); i++) 756 swsusp_set_page_free(pfn_to_page(pfn + i)); 757 } 758 759 spin_unlock_irqrestore(&zone->lock, flags); 760} 761 762/* 763 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 764 */ 765void drain_local_pages(void) 766{ 767 unsigned long flags; 768 769 local_irq_save(flags); 770 __drain_pages(smp_processor_id()); 771 local_irq_restore(flags); 772} 773#endif /* CONFIG_PM */ 774 775/* 776 * Free a 0-order page 777 */ 778static void fastcall free_hot_cold_page(struct page *page, int cold) 779{ 780 struct zone *zone = page_zone(page); 781 struct per_cpu_pages *pcp; 782 unsigned long flags; 783 784 if (PageAnon(page)) 785 page->mapping = NULL; 786 if (free_pages_check(page)) 787 return; 788 789 if (!PageHighMem(page)) 790 debug_check_no_locks_freed(page_address(page), PAGE_SIZE); 791 arch_free_page(page, 0); 792 kernel_map_pages(page, 1, 0); 793 794 pcp = &zone_pcp(zone, get_cpu())->pcp[cold]; 795 local_irq_save(flags); 796 __count_vm_event(PGFREE); 797 list_add(&page->lru, &pcp->list); 798 pcp->count++; 799 if (pcp->count >= pcp->high) { 800 free_pages_bulk(zone, pcp->batch, &pcp->list, 0); 801 pcp->count -= pcp->batch; 802 } 803 local_irq_restore(flags); 804 put_cpu(); 805} 806 807void fastcall free_hot_page(struct page *page) 808{ 809 free_hot_cold_page(page, 0); 810} 811 812void fastcall free_cold_page(struct page *page) 813{ 814 free_hot_cold_page(page, 1); 815} 816 817/* 818 * split_page takes a non-compound higher-order page, and splits it into 819 * n (1<<order) sub-pages: page[0..n] 820 * Each sub-page must be freed individually. 821 * 822 * Note: this is probably too low level an operation for use in drivers. 823 * Please consult with lkml before using this in your driver. 824 */ 825void split_page(struct page *page, unsigned int order) 826{ 827 int i; 828 829 VM_BUG_ON(PageCompound(page)); 830 VM_BUG_ON(!page_count(page)); 831 for (i = 1; i < (1 << order); i++) 832 set_page_refcounted(page + i); 833} 834 835/* 836 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 837 * we cheat by calling it from here, in the order > 0 path. Saves a branch 838 * or two. 839 */ 840static struct page *buffered_rmqueue(struct zonelist *zonelist, 841 struct zone *zone, int order, gfp_t gfp_flags) 842{ 843 unsigned long flags; 844 struct page *page; 845 int cold = !!(gfp_flags & __GFP_COLD); 846 int cpu; 847 848again: 849 cpu = get_cpu(); 850 if (likely(order == 0)) { 851 struct per_cpu_pages *pcp; 852 853 pcp = &zone_pcp(zone, cpu)->pcp[cold]; 854 local_irq_save(flags); 855 if (!pcp->count) { 856 pcp->count = rmqueue_bulk(zone, 0, 857 pcp->batch, &pcp->list); 858 if (unlikely(!pcp->count)) 859 goto failed; 860 } 861 page = list_entry(pcp->list.next, struct page, lru); 862 list_del(&page->lru); 863 pcp->count--; 864 } else { 865 spin_lock_irqsave(&zone->lock, flags); 866 page = __rmqueue(zone, order); 867 spin_unlock(&zone->lock); 868 if (!page) 869 goto failed; 870 } 871 872 __count_zone_vm_events(PGALLOC, zone, 1 << order); 873 zone_statistics(zonelist, zone); 874 local_irq_restore(flags); 875 put_cpu(); 876 877 VM_BUG_ON(bad_range(zone, page)); 878 if (prep_new_page(page, order, gfp_flags)) 879 goto again; 880 return page; 881 882failed: 883 local_irq_restore(flags); 884 put_cpu(); 885 return NULL; 886} 887 888#define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */ 889#define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */ 890#define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */ 891#define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */ 892#define ALLOC_HARDER 0x10 /* try to alloc harder */ 893#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 894#define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 895 896#ifdef CONFIG_FAIL_PAGE_ALLOC 897 898static struct fail_page_alloc_attr { 899 struct fault_attr attr; 900 901 u32 ignore_gfp_highmem; 902 u32 ignore_gfp_wait; 903 904#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 905 906 struct dentry *ignore_gfp_highmem_file; 907 struct dentry *ignore_gfp_wait_file; 908 909#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 910 911} fail_page_alloc = { 912 .attr = FAULT_ATTR_INITIALIZER, 913 .ignore_gfp_wait = 1, 914 .ignore_gfp_highmem = 1, 915}; 916 917static int __init setup_fail_page_alloc(char *str) 918{ 919 return setup_fault_attr(&fail_page_alloc.attr, str); 920} 921__setup("fail_page_alloc=", setup_fail_page_alloc); 922 923static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 924{ 925 if (gfp_mask & __GFP_NOFAIL) 926 return 0; 927 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 928 return 0; 929 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) 930 return 0; 931 932 return should_fail(&fail_page_alloc.attr, 1 << order); 933} 934 935#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 936 937static int __init fail_page_alloc_debugfs(void) 938{ 939 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; 940 struct dentry *dir; 941 int err; 942 943 err = init_fault_attr_dentries(&fail_page_alloc.attr, 944 "fail_page_alloc"); 945 if (err) 946 return err; 947 dir = fail_page_alloc.attr.dentries.dir; 948 949 fail_page_alloc.ignore_gfp_wait_file = 950 debugfs_create_bool("ignore-gfp-wait", mode, dir, 951 &fail_page_alloc.ignore_gfp_wait); 952 953 fail_page_alloc.ignore_gfp_highmem_file = 954 debugfs_create_bool("ignore-gfp-highmem", mode, dir, 955 &fail_page_alloc.ignore_gfp_highmem); 956 957 if (!fail_page_alloc.ignore_gfp_wait_file || 958 !fail_page_alloc.ignore_gfp_highmem_file) { 959 err = -ENOMEM; 960 debugfs_remove(fail_page_alloc.ignore_gfp_wait_file); 961 debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file); 962 cleanup_fault_attr_dentries(&fail_page_alloc.attr); 963 } 964 965 return err; 966} 967 968late_initcall(fail_page_alloc_debugfs); 969 970#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 971 972#else /* CONFIG_FAIL_PAGE_ALLOC */ 973 974static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 975{ 976 return 0; 977} 978 979#endif /* CONFIG_FAIL_PAGE_ALLOC */ 980 981/* 982 * Return 1 if free pages are above 'mark'. This takes into account the order 983 * of the allocation. 984 */ 985int zone_watermark_ok(struct zone *z, int order, unsigned long mark, 986 int classzone_idx, int alloc_flags) 987{ 988 /* free_pages my go negative - that's OK */ 989 long min = mark; 990 long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1; 991 int o; 992 993 if (alloc_flags & ALLOC_HIGH) 994 min -= min / 2; 995 if (alloc_flags & ALLOC_HARDER) 996 min -= min / 4; 997 998 if (free_pages <= min + z->lowmem_reserve[classzone_idx]) 999 return 0; 1000 for (o = 0; o < order; o++) { 1001 /* At the next order, this order's pages become unavailable */ 1002 free_pages -= z->free_area[o].nr_free << o; 1003 1004 /* Require fewer higher order pages to be free */ 1005 min >>= 1; 1006 1007 if (free_pages <= min) 1008 return 0; 1009 } 1010 return 1; 1011} 1012 1013#ifdef CONFIG_NUMA 1014/* 1015 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to 1016 * skip over zones that are not allowed by the cpuset, or that have 1017 * been recently (in last second) found to be nearly full. See further 1018 * comments in mmzone.h. Reduces cache footprint of zonelist scans 1019 * that have to skip over alot of full or unallowed zones. 1020 * 1021 * If the zonelist cache is present in the passed in zonelist, then 1022 * returns a pointer to the allowed node mask (either the current 1023 * tasks mems_allowed, or node_online_map.) 1024 * 1025 * If the zonelist cache is not available for this zonelist, does 1026 * nothing and returns NULL. 1027 * 1028 * If the fullzones BITMAP in the zonelist cache is stale (more than 1029 * a second since last zap'd) then we zap it out (clear its bits.) 1030 * 1031 * We hold off even calling zlc_setup, until after we've checked the 1032 * first zone in the zonelist, on the theory that most allocations will 1033 * be satisfied from that first zone, so best to examine that zone as 1034 * quickly as we can. 1035 */ 1036static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1037{ 1038 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1039 nodemask_t *allowednodes; /* zonelist_cache approximation */ 1040 1041 zlc = zonelist->zlcache_ptr; 1042 if (!zlc) 1043 return NULL; 1044 1045 if (jiffies - zlc->last_full_zap > 1 * HZ) { 1046 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1047 zlc->last_full_zap = jiffies; 1048 } 1049 1050 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? 1051 &cpuset_current_mems_allowed : 1052 &node_online_map; 1053 return allowednodes; 1054} 1055 1056/* 1057 * Given 'z' scanning a zonelist, run a couple of quick checks to see 1058 * if it is worth looking at further for free memory: 1059 * 1) Check that the zone isn't thought to be full (doesn't have its 1060 * bit set in the zonelist_cache fullzones BITMAP). 1061 * 2) Check that the zones node (obtained from the zonelist_cache 1062 * z_to_n[] mapping) is allowed in the passed in allowednodes mask. 1063 * Return true (non-zero) if zone is worth looking at further, or 1064 * else return false (zero) if it is not. 1065 * 1066 * This check -ignores- the distinction between various watermarks, 1067 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is 1068 * found to be full for any variation of these watermarks, it will 1069 * be considered full for up to one second by all requests, unless 1070 * we are so low on memory on all allowed nodes that we are forced 1071 * into the second scan of the zonelist. 1072 * 1073 * In the second scan we ignore this zonelist cache and exactly 1074 * apply the watermarks to all zones, even it is slower to do so. 1075 * We are low on memory in the second scan, and should leave no stone 1076 * unturned looking for a free page. 1077 */ 1078static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zone **z, 1079 nodemask_t *allowednodes) 1080{ 1081 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1082 int i; /* index of *z in zonelist zones */ 1083 int n; /* node that zone *z is on */ 1084 1085 zlc = zonelist->zlcache_ptr; 1086 if (!zlc) 1087 return 1; 1088 1089 i = z - zonelist->zones; 1090 n = zlc->z_to_n[i]; 1091 1092 /* This zone is worth trying if it is allowed but not full */ 1093 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); 1094} 1095 1096/* 1097 * Given 'z' scanning a zonelist, set the corresponding bit in 1098 * zlc->fullzones, so that subsequent attempts to allocate a page 1099 * from that zone don't waste time re-examining it. 1100 */ 1101static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **z) 1102{ 1103 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1104 int i; /* index of *z in zonelist zones */ 1105 1106 zlc = zonelist->zlcache_ptr; 1107 if (!zlc) 1108 return; 1109 1110 i = z - zonelist->zones; 1111 1112 set_bit(i, zlc->fullzones); 1113} 1114 1115#else /* CONFIG_NUMA */ 1116 1117static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1118{ 1119 return NULL; 1120} 1121 1122static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zone **z, 1123 nodemask_t *allowednodes) 1124{ 1125 return 1; 1126} 1127 1128static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **z) 1129{ 1130} 1131#endif /* CONFIG_NUMA */ 1132 1133/* 1134 * get_page_from_freelist goes through the zonelist trying to allocate 1135 * a page. 1136 */ 1137static struct page * 1138get_page_from_freelist(gfp_t gfp_mask, unsigned int order, 1139 struct zonelist *zonelist, int alloc_flags) 1140{ 1141 struct zone **z; 1142 struct page *page = NULL; 1143 int classzone_idx = zone_idx(zonelist->zones[0]); 1144 struct zone *zone; 1145 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ 1146 int zlc_active = 0; /* set if using zonelist_cache */ 1147 int did_zlc_setup = 0; /* just call zlc_setup() one time */ 1148 1149zonelist_scan: 1150 /* 1151 * Scan zonelist, looking for a zone with enough free. 1152 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1153 */ 1154 z = zonelist->zones; 1155 1156 do { 1157 if (NUMA_BUILD && zlc_active && 1158 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 1159 continue; 1160 zone = *z; 1161 if (unlikely(NUMA_BUILD && (gfp_mask & __GFP_THISNODE) && 1162 zone->zone_pgdat != zonelist->zones[0]->zone_pgdat)) 1163 break; 1164 if ((alloc_flags & ALLOC_CPUSET) && 1165 !cpuset_zone_allowed_softwall(zone, gfp_mask)) 1166 goto try_next_zone; 1167 1168 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { 1169 unsigned long mark; 1170 if (alloc_flags & ALLOC_WMARK_MIN) 1171 mark = zone->pages_min; 1172 else if (alloc_flags & ALLOC_WMARK_LOW) 1173 mark = zone->pages_low; 1174 else 1175 mark = zone->pages_high; 1176 if (!zone_watermark_ok(zone, order, mark, 1177 classzone_idx, alloc_flags)) { 1178 if (!zone_reclaim_mode || 1179 !zone_reclaim(zone, gfp_mask, order)) 1180 goto this_zone_full; 1181 } 1182 } 1183 1184 page = buffered_rmqueue(zonelist, zone, order, gfp_mask); 1185 if (page) 1186 break; 1187this_zone_full: 1188 if (NUMA_BUILD) 1189 zlc_mark_zone_full(zonelist, z); 1190try_next_zone: 1191 if (NUMA_BUILD && !did_zlc_setup) { 1192 /* we do zlc_setup after the first zone is tried */ 1193 allowednodes = zlc_setup(zonelist, alloc_flags); 1194 zlc_active = 1; 1195 did_zlc_setup = 1; 1196 } 1197 } while (*(++z) != NULL); 1198 1199 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) { 1200 /* Disable zlc cache for second zonelist scan */ 1201 zlc_active = 0; 1202 goto zonelist_scan; 1203 } 1204 return page; 1205} 1206 1207/* 1208 * This is the 'heart' of the zoned buddy allocator. 1209 */ 1210struct page * fastcall 1211__alloc_pages(gfp_t gfp_mask, unsigned int order, 1212 struct zonelist *zonelist) 1213{ 1214 const gfp_t wait = gfp_mask & __GFP_WAIT; 1215 struct zone **z; 1216 struct page *page; 1217 struct reclaim_state reclaim_state; 1218 struct task_struct *p = current; 1219 int do_retry; 1220 int alloc_flags; 1221 int did_some_progress; 1222 1223 might_sleep_if(wait); 1224 1225 if (should_fail_alloc_page(gfp_mask, order)) 1226 return NULL; 1227 1228restart: 1229 z = zonelist->zones; /* the list of zones suitable for gfp_mask */ 1230 1231 if (unlikely(*z == NULL)) { 1232 /* Should this ever happen?? */ 1233 return NULL; 1234 } 1235 1236 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order, 1237 zonelist, ALLOC_WMARK_LOW|ALLOC_CPUSET); 1238 if (page) 1239 goto got_pg; 1240 1241 /* 1242 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and 1243 * __GFP_NOWARN set) should not cause reclaim since the subsystem 1244 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim 1245 * using a larger set of nodes after it has established that the 1246 * allowed per node queues are empty and that nodes are 1247 * over allocated. 1248 */ 1249 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) 1250 goto nopage; 1251 1252 for (z = zonelist->zones; *z; z++) 1253 wakeup_kswapd(*z, order); 1254 1255 /* 1256 * OK, we're below the kswapd watermark and have kicked background 1257 * reclaim. Now things get more complex, so set up alloc_flags according 1258 * to how we want to proceed. 1259 * 1260 * The caller may dip into page reserves a bit more if the caller 1261 * cannot run direct reclaim, or if the caller has realtime scheduling 1262 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will 1263 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). 1264 */ 1265 alloc_flags = ALLOC_WMARK_MIN; 1266 if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait) 1267 alloc_flags |= ALLOC_HARDER; 1268 if (gfp_mask & __GFP_HIGH) 1269 alloc_flags |= ALLOC_HIGH; 1270 if (wait) 1271 alloc_flags |= ALLOC_CPUSET; 1272 1273 /* 1274 * Go through the zonelist again. Let __GFP_HIGH and allocations 1275 * coming from realtime tasks go deeper into reserves. 1276 * 1277 * This is the last chance, in general, before the goto nopage. 1278 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. 1279 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1280 */ 1281 page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags); 1282 if (page) 1283 goto got_pg; 1284 1285 /* This allocation should allow future memory freeing. */ 1286 1287rebalance: 1288 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) 1289 && !in_interrupt()) { 1290 if (!(gfp_mask & __GFP_NOMEMALLOC)) { 1291nofail_alloc: 1292 /* go through the zonelist yet again, ignoring mins */ 1293 page = get_page_from_freelist(gfp_mask, order, 1294 zonelist, ALLOC_NO_WATERMARKS); 1295 if (page) 1296 goto got_pg; 1297 if (gfp_mask & __GFP_NOFAIL) { 1298 congestion_wait(WRITE, HZ/50); 1299 goto nofail_alloc; 1300 } 1301 } 1302 goto nopage; 1303 } 1304 1305 /* Atomic allocations - we can't balance anything */ 1306 if (!wait) 1307 goto nopage; 1308 1309 cond_resched(); 1310 1311 /* We now go into synchronous reclaim */ 1312 cpuset_memory_pressure_bump(); 1313 p->flags |= PF_MEMALLOC; 1314 reclaim_state.reclaimed_slab = 0; 1315 p->reclaim_state = &reclaim_state; 1316 1317 did_some_progress = try_to_free_pages(zonelist->zones, gfp_mask); 1318 1319 p->reclaim_state = NULL; 1320 p->flags &= ~PF_MEMALLOC; 1321 1322 cond_resched(); 1323 1324 if (likely(did_some_progress)) { 1325 page = get_page_from_freelist(gfp_mask, order, 1326 zonelist, alloc_flags); 1327 if (page) 1328 goto got_pg; 1329 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { 1330 /* 1331 * Go through the zonelist yet one more time, keep 1332 * very high watermark here, this is only to catch 1333 * a parallel oom killing, we must fail if we're still 1334 * under heavy pressure. 1335 */ 1336 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order, 1337 zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET); 1338 if (page) 1339 goto got_pg; 1340 1341 out_of_memory(zonelist, gfp_mask, order); 1342 goto restart; 1343 } 1344 1345 /* 1346 * Don't let big-order allocations loop unless the caller explicitly 1347 * requests that. Wait for some write requests to complete then retry. 1348 * 1349 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order 1350 * <= 3, but that may not be true in other implementations. 1351 */ 1352 do_retry = 0; 1353 if (!(gfp_mask & __GFP_NORETRY)) { 1354 if ((order <= 3) || (gfp_mask & __GFP_REPEAT)) 1355 do_retry = 1; 1356 if (gfp_mask & __GFP_NOFAIL) 1357 do_retry = 1; 1358 } 1359 if (do_retry) { 1360 congestion_wait(WRITE, HZ/50); 1361 goto rebalance; 1362 } 1363 1364nopage: 1365 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { 1366 printk(KERN_WARNING "%s: page allocation failure." 1367 " order:%d, mode:0x%x\n", 1368 p->comm, order, gfp_mask); 1369 dump_stack(); 1370 show_mem(); 1371 } 1372got_pg: 1373 return page; 1374} 1375 1376EXPORT_SYMBOL(__alloc_pages); 1377 1378/* 1379 * Common helper functions. 1380 */ 1381fastcall unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 1382{ 1383 struct page * page; 1384 page = alloc_pages(gfp_mask, order); 1385 if (!page) 1386 return 0; 1387 return (unsigned long) page_address(page); 1388} 1389 1390EXPORT_SYMBOL(__get_free_pages); 1391 1392fastcall unsigned long get_zeroed_page(gfp_t gfp_mask) 1393{ 1394 struct page * page; 1395 1396 /* 1397 * get_zeroed_page() returns a 32-bit address, which cannot represent 1398 * a highmem page 1399 */ 1400 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 1401 1402 page = alloc_pages(gfp_mask | __GFP_ZERO, 0); 1403 if (page) 1404 return (unsigned long) page_address(page); 1405 return 0; 1406} 1407 1408EXPORT_SYMBOL(get_zeroed_page); 1409 1410void __pagevec_free(struct pagevec *pvec) 1411{ 1412 int i = pagevec_count(pvec); 1413 1414 while (--i >= 0) 1415 free_hot_cold_page(pvec->pages[i], pvec->cold); 1416} 1417 1418fastcall void __free_pages(struct page *page, unsigned int order) 1419{ 1420 if (put_page_testzero(page)) { 1421 if (order == 0) 1422 free_hot_page(page); 1423 else 1424 __free_pages_ok(page, order); 1425 } 1426} 1427 1428EXPORT_SYMBOL(__free_pages); 1429 1430fastcall void free_pages(unsigned long addr, unsigned int order) 1431{ 1432 if (addr != 0) { 1433 VM_BUG_ON(!virt_addr_valid((void *)addr)); 1434 __free_pages(virt_to_page((void *)addr), order); 1435 } 1436} 1437 1438EXPORT_SYMBOL(free_pages); 1439 1440static unsigned int nr_free_zone_pages(int offset) 1441{ 1442 /* Just pick one node, since fallback list is circular */ 1443 pg_data_t *pgdat = NODE_DATA(numa_node_id()); 1444 unsigned int sum = 0; 1445 1446 struct zonelist *zonelist = pgdat->node_zonelists + offset; 1447 struct zone **zonep = zonelist->zones; 1448 struct zone *zone; 1449 1450 for (zone = *zonep++; zone; zone = *zonep++) { 1451 unsigned long size = zone->present_pages; 1452 unsigned long high = zone->pages_high; 1453 if (size > high) 1454 sum += size - high; 1455 } 1456 1457 return sum; 1458} 1459 1460/* 1461 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL 1462 */ 1463unsigned int nr_free_buffer_pages(void) 1464{ 1465 return nr_free_zone_pages(gfp_zone(GFP_USER)); 1466} 1467 1468/* 1469 * Amount of free RAM allocatable within all zones 1470 */ 1471unsigned int nr_free_pagecache_pages(void) 1472{ 1473 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER)); 1474} 1475 1476static inline void show_node(struct zone *zone) 1477{ 1478 if (NUMA_BUILD) 1479 printk("Node %d ", zone_to_nid(zone)); 1480} 1481 1482void si_meminfo(struct sysinfo *val) 1483{ 1484 val->totalram = totalram_pages; 1485 val->sharedram = 0; 1486 val->freeram = global_page_state(NR_FREE_PAGES); 1487 val->bufferram = nr_blockdev_pages(); 1488 val->totalhigh = totalhigh_pages; 1489 val->freehigh = nr_free_highpages(); 1490 val->mem_unit = PAGE_SIZE; 1491} 1492 1493EXPORT_SYMBOL(si_meminfo); 1494 1495#ifdef CONFIG_NUMA 1496void si_meminfo_node(struct sysinfo *val, int nid) 1497{ 1498 pg_data_t *pgdat = NODE_DATA(nid); 1499 1500 val->totalram = pgdat->node_present_pages; 1501 val->freeram = node_page_state(nid, NR_FREE_PAGES); 1502#ifdef CONFIG_HIGHMEM 1503 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; 1504 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], 1505 NR_FREE_PAGES); 1506#else 1507 val->totalhigh = 0; 1508 val->freehigh = 0; 1509#endif 1510 val->mem_unit = PAGE_SIZE; 1511} 1512#endif 1513 1514#define K(x) ((x) << (PAGE_SHIFT-10)) 1515 1516/* 1517 * Show free area list (used inside shift_scroll-lock stuff) 1518 * We also calculate the percentage fragmentation. We do this by counting the 1519 * memory on each free list with the exception of the first item on the list. 1520 */ 1521void show_free_areas(void) 1522{ 1523 int cpu; 1524 struct zone *zone; 1525 1526 for_each_zone(zone) { 1527 if (!populated_zone(zone)) 1528 continue; 1529 1530 show_node(zone); 1531 printk("%s per-cpu:\n", zone->name); 1532 1533 for_each_online_cpu(cpu) { 1534 struct per_cpu_pageset *pageset; 1535 1536 pageset = zone_pcp(zone, cpu); 1537 1538 printk("CPU %4d: Hot: hi:%5d, btch:%4d usd:%4d " 1539 "Cold: hi:%5d, btch:%4d usd:%4d\n", 1540 cpu, pageset->pcp[0].high, 1541 pageset->pcp[0].batch, pageset->pcp[0].count, 1542 pageset->pcp[1].high, pageset->pcp[1].batch, 1543 pageset->pcp[1].count); 1544 } 1545 } 1546 1547 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu\n" 1548 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n", 1549 global_page_state(NR_ACTIVE), 1550 global_page_state(NR_INACTIVE), 1551 global_page_state(NR_FILE_DIRTY), 1552 global_page_state(NR_WRITEBACK), 1553 global_page_state(NR_UNSTABLE_NFS), 1554 global_page_state(NR_FREE_PAGES), 1555 global_page_state(NR_SLAB_RECLAIMABLE) + 1556 global_page_state(NR_SLAB_UNRECLAIMABLE), 1557 global_page_state(NR_FILE_MAPPED), 1558 global_page_state(NR_PAGETABLE), 1559 global_page_state(NR_BOUNCE)); 1560 1561 for_each_zone(zone) { 1562 int i; 1563 1564 if (!populated_zone(zone)) 1565 continue; 1566 1567 show_node(zone); 1568 printk("%s" 1569 " free:%lukB" 1570 " min:%lukB" 1571 " low:%lukB" 1572 " high:%lukB" 1573 " active:%lukB" 1574 " inactive:%lukB" 1575 " present:%lukB" 1576 " pages_scanned:%lu" 1577 " all_unreclaimable? %s" 1578 "\n", 1579 zone->name, 1580 K(zone_page_state(zone, NR_FREE_PAGES)), 1581 K(zone->pages_min), 1582 K(zone->pages_low), 1583 K(zone->pages_high), 1584 K(zone_page_state(zone, NR_ACTIVE)), 1585 K(zone_page_state(zone, NR_INACTIVE)), 1586 K(zone->present_pages), 1587 zone->pages_scanned, 1588 (zone->all_unreclaimable ? "yes" : "no") 1589 ); 1590 printk("lowmem_reserve[]:"); 1591 for (i = 0; i < MAX_NR_ZONES; i++) 1592 printk(" %lu", zone->lowmem_reserve[i]); 1593 printk("\n"); 1594 } 1595 1596 for_each_zone(zone) { 1597 unsigned long nr[MAX_ORDER], flags, order, total = 0; 1598 1599 if (!populated_zone(zone)) 1600 continue; 1601 1602 show_node(zone); 1603 printk("%s: ", zone->name); 1604 1605 spin_lock_irqsave(&zone->lock, flags); 1606 for (order = 0; order < MAX_ORDER; order++) { 1607 nr[order] = zone->free_area[order].nr_free; 1608 total += nr[order] << order; 1609 } 1610 spin_unlock_irqrestore(&zone->lock, flags); 1611 for (order = 0; order < MAX_ORDER; order++) 1612 printk("%lu*%lukB ", nr[order], K(1UL) << order); 1613 printk("= %lukB\n", K(total)); 1614 } 1615 1616 show_swap_cache_info(); 1617} 1618 1619/* 1620 * Builds allocation fallback zone lists. 1621 * 1622 * Add all populated zones of a node to the zonelist. 1623 */ 1624static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, 1625 int nr_zones, enum zone_type zone_type) 1626{ 1627 struct zone *zone; 1628 1629 BUG_ON(zone_type >= MAX_NR_ZONES); 1630 zone_type++; 1631 1632 do { 1633 zone_type--; 1634 zone = pgdat->node_zones + zone_type; 1635 if (populated_zone(zone)) { 1636 zonelist->zones[nr_zones++] = zone; 1637 check_highest_zone(zone_type); 1638 } 1639 1640 } while (zone_type); 1641 return nr_zones; 1642} 1643 1644 1645/* 1646 * zonelist_order: 1647 * 0 = automatic detection of better ordering. 1648 * 1 = order by ([node] distance, -zonetype) 1649 * 2 = order by (-zonetype, [node] distance) 1650 * 1651 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create 1652 * the same zonelist. So only NUMA can configure this param. 1653 */ 1654#define ZONELIST_ORDER_DEFAULT 0 1655#define ZONELIST_ORDER_NODE 1 1656#define ZONELIST_ORDER_ZONE 2 1657 1658/* zonelist order in the kernel. 1659 * set_zonelist_order() will set this to NODE or ZONE. 1660 */ 1661static int current_zonelist_order = ZONELIST_ORDER_DEFAULT; 1662static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"}; 1663 1664 1665#ifdef CONFIG_NUMA 1666/* The value user specified ....changed by config */ 1667static int user_zonelist_order = ZONELIST_ORDER_DEFAULT; 1668/* string for sysctl */ 1669#define NUMA_ZONELIST_ORDER_LEN 16 1670char numa_zonelist_order[16] = "default"; 1671 1672/* 1673 * interface for configure zonelist ordering. 1674 * command line option "numa_zonelist_order" 1675 * = "[dD]efault - default, automatic configuration. 1676 * = "[nN]ode - order by node locality, then by zone within node 1677 * = "[zZ]one - order by zone, then by locality within zone 1678 */ 1679 1680static int __parse_numa_zonelist_order(char *s) 1681{ 1682 if (*s == 'd' || *s == 'D') { 1683 user_zonelist_order = ZONELIST_ORDER_DEFAULT; 1684 } else if (*s == 'n' || *s == 'N') { 1685 user_zonelist_order = ZONELIST_ORDER_NODE; 1686 } else if (*s == 'z' || *s == 'Z') { 1687 user_zonelist_order = ZONELIST_ORDER_ZONE; 1688 } else { 1689 printk(KERN_WARNING 1690 "Ignoring invalid numa_zonelist_order value: " 1691 "%s\n", s); 1692 return -EINVAL; 1693 } 1694 return 0; 1695} 1696 1697static __init int setup_numa_zonelist_order(char *s) 1698{ 1699 if (s) 1700 return __parse_numa_zonelist_order(s); 1701 return 0; 1702} 1703early_param("numa_zonelist_order", setup_numa_zonelist_order); 1704 1705/* 1706 * sysctl handler for numa_zonelist_order 1707 */ 1708int numa_zonelist_order_handler(ctl_table *table, int write, 1709 struct file *file, void __user *buffer, size_t *length, 1710 loff_t *ppos) 1711{ 1712 char saved_string[NUMA_ZONELIST_ORDER_LEN]; 1713 int ret; 1714 1715 if (write) 1716 strncpy(saved_string, (char*)table->data, 1717 NUMA_ZONELIST_ORDER_LEN); 1718 ret = proc_dostring(table, write, file, buffer, length, ppos); 1719 if (ret) 1720 return ret; 1721 if (write) { 1722 int oldval = user_zonelist_order; 1723 if (__parse_numa_zonelist_order((char*)table->data)) { 1724 /* 1725 * bogus value. restore saved string 1726 */ 1727 strncpy((char*)table->data, saved_string, 1728 NUMA_ZONELIST_ORDER_LEN); 1729 user_zonelist_order = oldval; 1730 } else if (oldval != user_zonelist_order) 1731 build_all_zonelists(); 1732 } 1733 return 0; 1734} 1735 1736 1737#define MAX_NODE_LOAD (num_online_nodes()) 1738static int node_load[MAX_NUMNODES]; 1739 1740/** 1741 * find_next_best_node - find the next node that should appear in a given node's fallback list 1742 * @node: node whose fallback list we're appending 1743 * @used_node_mask: nodemask_t of already used nodes 1744 * 1745 * We use a number of factors to determine which is the next node that should 1746 * appear on a given node's fallback list. The node should not have appeared 1747 * already in @node's fallback list, and it should be the next closest node 1748 * according to the distance array (which contains arbitrary distance values 1749 * from each node to each node in the system), and should also prefer nodes 1750 * with no CPUs, since presumably they'll have very little allocation pressure 1751 * on them otherwise. 1752 * It returns -1 if no node is found. 1753 */ 1754static int find_next_best_node(int node, nodemask_t *used_node_mask) 1755{ 1756 int n, val; 1757 int min_val = INT_MAX; 1758 int best_node = -1; 1759 1760 /* Use the local node if we haven't already */ 1761 if (!node_isset(node, *used_node_mask)) { 1762 node_set(node, *used_node_mask); 1763 return node; 1764 } 1765 1766 for_each_online_node(n) { 1767 cpumask_t tmp; 1768 1769 /* Don't want a node to appear more than once */ 1770 if (node_isset(n, *used_node_mask)) 1771 continue; 1772 1773 /* Use the distance array to find the distance */ 1774 val = node_distance(node, n); 1775 1776 /* Penalize nodes under us ("prefer the next node") */ 1777 val += (n < node); 1778 1779 /* Give preference to headless and unused nodes */ 1780 tmp = node_to_cpumask(n); 1781 if (!cpus_empty(tmp)) 1782 val += PENALTY_FOR_NODE_WITH_CPUS; 1783 1784 /* Slight preference for less loaded node */ 1785 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 1786 val += node_load[n]; 1787 1788 if (val < min_val) { 1789 min_val = val; 1790 best_node = n; 1791 } 1792 } 1793 1794 if (best_node >= 0) 1795 node_set(best_node, *used_node_mask); 1796 1797 return best_node; 1798} 1799 1800 1801/* 1802 * Build zonelists ordered by node and zones within node. 1803 * This results in maximum locality--normal zone overflows into local 1804 * DMA zone, if any--but risks exhausting DMA zone. 1805 */ 1806static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) 1807{ 1808 enum zone_type i; 1809 int j; 1810 struct zonelist *zonelist; 1811 1812 for (i = 0; i < MAX_NR_ZONES; i++) { 1813 zonelist = pgdat->node_zonelists + i; 1814 for (j = 0; zonelist->zones[j] != NULL; j++) 1815 ; 1816 j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); 1817 zonelist->zones[j] = NULL; 1818 } 1819} 1820 1821/* 1822 * Build zonelists ordered by zone and nodes within zones. 1823 * This results in conserving DMA zone[s] until all Normal memory is 1824 * exhausted, but results in overflowing to remote node while memory 1825 * may still exist in local DMA zone. 1826 */ 1827static int node_order[MAX_NUMNODES]; 1828 1829static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) 1830{ 1831 enum zone_type i; 1832 int pos, j, node; 1833 int zone_type; /* needs to be signed */ 1834 struct zone *z; 1835 struct zonelist *zonelist; 1836 1837 for (i = 0; i < MAX_NR_ZONES; i++) { 1838 zonelist = pgdat->node_zonelists + i; 1839 pos = 0; 1840 for (zone_type = i; zone_type >= 0; zone_type--) { 1841 for (j = 0; j < nr_nodes; j++) { 1842 node = node_order[j]; 1843 z = &NODE_DATA(node)->node_zones[zone_type]; 1844 if (populated_zone(z)) { 1845 zonelist->zones[pos++] = z; 1846 check_highest_zone(zone_type); 1847 } 1848 } 1849 } 1850 zonelist->zones[pos] = NULL; 1851 } 1852} 1853 1854static int default_zonelist_order(void) 1855{ 1856 int nid, zone_type; 1857 unsigned long low_kmem_size,total_size; 1858 struct zone *z; 1859 int average_size; 1860 /* 1861 * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem. 1862 * If they are really small and used heavily, the system can fall 1863 * into OOM very easily. 1864 * This function detect ZONE_DMA/DMA32 size and confgigures zone order. 1865 */ 1866 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */ 1867 low_kmem_size = 0; 1868 total_size = 0; 1869 for_each_online_node(nid) { 1870 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 1871 z = &NODE_DATA(nid)->node_zones[zone_type]; 1872 if (populated_zone(z)) { 1873 if (zone_type < ZONE_NORMAL) 1874 low_kmem_size += z->present_pages; 1875 total_size += z->present_pages; 1876 } 1877 } 1878 } 1879 if (!low_kmem_size || /* there are no DMA area. */ 1880 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */ 1881 return ZONELIST_ORDER_NODE; 1882 /* 1883 * look into each node's config. 1884 * If there is a node whose DMA/DMA32 memory is very big area on 1885 * local memory, NODE_ORDER may be suitable. 1886 */ 1887 average_size = total_size / (num_online_nodes() + 1); 1888 for_each_online_node(nid) { 1889 low_kmem_size = 0; 1890 total_size = 0; 1891 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 1892 z = &NODE_DATA(nid)->node_zones[zone_type]; 1893 if (populated_zone(z)) { 1894 if (zone_type < ZONE_NORMAL) 1895 low_kmem_size += z->present_pages; 1896 total_size += z->present_pages; 1897 } 1898 } 1899 if (low_kmem_size && 1900 total_size > average_size && /* ignore small node */ 1901 low_kmem_size > total_size * 70/100) 1902 return ZONELIST_ORDER_NODE; 1903 } 1904 return ZONELIST_ORDER_ZONE; 1905} 1906 1907static void set_zonelist_order(void) 1908{ 1909 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT) 1910 current_zonelist_order = default_zonelist_order(); 1911 else 1912 current_zonelist_order = user_zonelist_order; 1913} 1914 1915static void build_zonelists(pg_data_t *pgdat) 1916{ 1917 int j, node, load; 1918 enum zone_type i; 1919 nodemask_t used_mask; 1920 int local_node, prev_node; 1921 struct zonelist *zonelist; 1922 int order = current_zonelist_order; 1923 1924 /* initialize zonelists */ 1925 for (i = 0; i < MAX_NR_ZONES; i++) { 1926 zonelist = pgdat->node_zonelists + i; 1927 zonelist->zones[0] = NULL; 1928 } 1929 1930 /* NUMA-aware ordering of nodes */ 1931 local_node = pgdat->node_id; 1932 load = num_online_nodes(); 1933 prev_node = local_node; 1934 nodes_clear(used_mask); 1935 1936 memset(node_load, 0, sizeof(node_load)); 1937 memset(node_order, 0, sizeof(node_order)); 1938 j = 0; 1939 1940 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 1941 int distance = node_distance(local_node, node); 1942 1943 /* 1944 * If another node is sufficiently far away then it is better 1945 * to reclaim pages in a zone before going off node. 1946 */ 1947 if (distance > RECLAIM_DISTANCE) 1948 zone_reclaim_mode = 1; 1949 1950 /* 1951 * We don't want to pressure a particular node. 1952 * So adding penalty to the first node in same 1953 * distance group to make it round-robin. 1954 */ 1955 if (distance != node_distance(local_node, prev_node)) 1956 node_load[node] = load; 1957 1958 prev_node = node; 1959 load--; 1960 if (order == ZONELIST_ORDER_NODE) 1961 build_zonelists_in_node_order(pgdat, node); 1962 else 1963 node_order[j++] = node; /* remember order */ 1964 } 1965 1966 if (order == ZONELIST_ORDER_ZONE) { 1967 /* calculate node order -- i.e., DMA last! */ 1968 build_zonelists_in_zone_order(pgdat, j); 1969 } 1970} 1971 1972/* Construct the zonelist performance cache - see further mmzone.h */ 1973static void build_zonelist_cache(pg_data_t *pgdat) 1974{ 1975 int i; 1976 1977 for (i = 0; i < MAX_NR_ZONES; i++) { 1978 struct zonelist *zonelist; 1979 struct zonelist_cache *zlc; 1980 struct zone **z; 1981 1982 zonelist = pgdat->node_zonelists + i; 1983 zonelist->zlcache_ptr = zlc = &zonelist->zlcache; 1984 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1985 for (z = zonelist->zones; *z; z++) 1986 zlc->z_to_n[z - zonelist->zones] = zone_to_nid(*z); 1987 } 1988} 1989 1990 1991#else /* CONFIG_NUMA */ 1992 1993static void set_zonelist_order(void) 1994{ 1995 current_zonelist_order = ZONELIST_ORDER_ZONE; 1996} 1997 1998static void build_zonelists(pg_data_t *pgdat) 1999{ 2000 int node, local_node; 2001 enum zone_type i,j; 2002 2003 local_node = pgdat->node_id; 2004 for (i = 0; i < MAX_NR_ZONES; i++) { 2005 struct zonelist *zonelist; 2006 2007 zonelist = pgdat->node_zonelists + i; 2008 2009 j = build_zonelists_node(pgdat, zonelist, 0, i); 2010 /* 2011 * Now we build the zonelist so that it contains the zones 2012 * of all the other nodes. 2013 * We don't want to pressure a particular node, so when 2014 * building the zones for node N, we make sure that the 2015 * zones coming right after the local ones are those from 2016 * node N+1 (modulo N) 2017 */ 2018 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 2019 if (!node_online(node)) 2020 continue; 2021 j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); 2022 } 2023 for (node = 0; node < local_node; node++) { 2024 if (!node_online(node)) 2025 continue; 2026 j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); 2027 } 2028 2029 zonelist->zones[j] = NULL; 2030 } 2031} 2032 2033/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ 2034static void build_zonelist_cache(pg_data_t *pgdat) 2035{ 2036 int i; 2037 2038 for (i = 0; i < MAX_NR_ZONES; i++) 2039 pgdat->node_zonelists[i].zlcache_ptr = NULL; 2040} 2041 2042#endif /* CONFIG_NUMA */ 2043 2044/* return values int ....just for stop_machine_run() */ 2045static int __build_all_zonelists(void *dummy) 2046{ 2047 int nid; 2048 2049 for_each_online_node(nid) { 2050 build_zonelists(NODE_DATA(nid)); 2051 build_zonelist_cache(NODE_DATA(nid)); 2052 } 2053 return 0; 2054} 2055 2056void build_all_zonelists(void) 2057{ 2058 set_zonelist_order(); 2059 2060 if (system_state == SYSTEM_BOOTING) { 2061 __build_all_zonelists(NULL); 2062 cpuset_init_current_mems_allowed(); 2063 } else { 2064 /* we have to stop all cpus to guaranntee there is no user 2065 of zonelist */ 2066 stop_machine_run(__build_all_zonelists, NULL, NR_CPUS); 2067 /* cpuset refresh routine should be here */ 2068 } 2069 vm_total_pages = nr_free_pagecache_pages(); 2070 printk("Built %i zonelists in %s order. Total pages: %ld\n", 2071 num_online_nodes(), 2072 zonelist_order_name[current_zonelist_order], 2073 vm_total_pages); 2074#ifdef CONFIG_NUMA 2075 printk("Policy zone: %s\n", zone_names[policy_zone]); 2076#endif 2077} 2078 2079/* 2080 * Helper functions to size the waitqueue hash table. 2081 * Essentially these want to choose hash table sizes sufficiently 2082 * large so that collisions trying to wait on pages are rare. 2083 * But in fact, the number of active page waitqueues on typical 2084 * systems is ridiculously low, less than 200. So this is even 2085 * conservative, even though it seems large. 2086 * 2087 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 2088 * waitqueues, i.e. the size of the waitq table given the number of pages. 2089 */ 2090#define PAGES_PER_WAITQUEUE 256 2091 2092#ifndef CONFIG_MEMORY_HOTPLUG 2093static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2094{ 2095 unsigned long size = 1; 2096 2097 pages /= PAGES_PER_WAITQUEUE; 2098 2099 while (size < pages) 2100 size <<= 1; 2101 2102 /* 2103 * Once we have dozens or even hundreds of threads sleeping 2104 * on IO we've got bigger problems than wait queue collision. 2105 * Limit the size of the wait table to a reasonable size. 2106 */ 2107 size = min(size, 4096UL); 2108 2109 return max(size, 4UL); 2110} 2111#else 2112/* 2113 * A zone's size might be changed by hot-add, so it is not possible to determine 2114 * a suitable size for its wait_table. So we use the maximum size now. 2115 * 2116 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: 2117 * 2118 * i386 (preemption config) : 4096 x 16 = 64Kbyte. 2119 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. 2120 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. 2121 * 2122 * The maximum entries are prepared when a zone's memory is (512K + 256) pages 2123 * or more by the traditional way. (See above). It equals: 2124 * 2125 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. 2126 * ia64(16K page size) : = ( 8G + 4M)byte. 2127 * powerpc (64K page size) : = (32G +16M)byte. 2128 */ 2129static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 2130{ 2131 return 4096UL; 2132} 2133#endif 2134 2135/* 2136 * This is an integer logarithm so that shifts can be used later 2137 * to extract the more random high bits from the multiplicative 2138 * hash function before the remainder is taken. 2139 */ 2140static inline unsigned long wait_table_bits(unsigned long size) 2141{ 2142 return ffz(~size); 2143} 2144 2145#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) 2146 2147/* 2148 * Initially all pages are reserved - free ones are freed 2149 * up by free_all_bootmem() once the early boot process is 2150 * done. Non-atomic initialization, single-pass. 2151 */ 2152void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 2153 unsigned long start_pfn, enum memmap_context context) 2154{ 2155 struct page *page; 2156 unsigned long end_pfn = start_pfn + size; 2157 unsigned long pfn; 2158 2159 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 2160 /* 2161 * There can be holes in boot-time mem_map[]s 2162 * handed to this function. They do not 2163 * exist on hotplugged memory. 2164 */ 2165 if (context == MEMMAP_EARLY) { 2166 if (!early_pfn_valid(pfn)) 2167 continue; 2168 if (!early_pfn_in_nid(pfn, nid)) 2169 continue; 2170 } 2171 page = pfn_to_page(pfn); 2172 set_page_links(page, zone, nid, pfn); 2173 init_page_count(page); 2174 reset_page_mapcount(page); 2175 SetPageReserved(page); 2176 INIT_LIST_HEAD(&page->lru); 2177#ifdef WANT_PAGE_VIRTUAL 2178 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 2179 if (!is_highmem_idx(zone)) 2180 set_page_address(page, __va(pfn << PAGE_SHIFT)); 2181#endif 2182 } 2183} 2184 2185static void __meminit zone_init_free_lists(struct pglist_data *pgdat, 2186 struct zone *zone, unsigned long size) 2187{ 2188 int order; 2189 for (order = 0; order < MAX_ORDER ; order++) { 2190 INIT_LIST_HEAD(&zone->free_area[order].free_list); 2191 zone->free_area[order].nr_free = 0; 2192 } 2193} 2194 2195#ifndef __HAVE_ARCH_MEMMAP_INIT 2196#define memmap_init(size, nid, zone, start_pfn) \ 2197 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) 2198#endif 2199 2200static int __devinit zone_batchsize(struct zone *zone) 2201{ 2202 int batch; 2203 2204 /* 2205 * The per-cpu-pages pools are set to around 1000th of the 2206 * size of the zone. But no more than 1/2 of a meg. 2207 * 2208 * OK, so we don't know how big the cache is. So guess. 2209 */ 2210 batch = zone->present_pages / 1024; 2211 if (batch * PAGE_SIZE > 512 * 1024) 2212 batch = (512 * 1024) / PAGE_SIZE; 2213 batch /= 4; /* We effectively *= 4 below */ 2214 if (batch < 1) 2215 batch = 1; 2216 2217 /* 2218 * Clamp the batch to a 2^n - 1 value. Having a power 2219 * of 2 value was found to be more likely to have 2220 * suboptimal cache aliasing properties in some cases. 2221 * 2222 * For example if 2 tasks are alternately allocating 2223 * batches of pages, one task can end up with a lot 2224 * of pages of one half of the possible page colors 2225 * and the other with pages of the other colors. 2226 */ 2227 batch = (1 << (fls(batch + batch/2)-1)) - 1; 2228 2229 return batch; 2230} 2231 2232inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 2233{ 2234 struct per_cpu_pages *pcp; 2235 2236 memset(p, 0, sizeof(*p)); 2237 2238 pcp = &p->pcp[0]; /* hot */ 2239 pcp->count = 0; 2240 pcp->high = 6 * batch; 2241 pcp->batch = max(1UL, 1 * batch); 2242 INIT_LIST_HEAD(&pcp->list); 2243 2244 pcp = &p->pcp[1]; /* cold*/ 2245 pcp->count = 0; 2246 pcp->high = 2 * batch; 2247 pcp->batch = max(1UL, batch/2); 2248 INIT_LIST_HEAD(&pcp->list); 2249} 2250 2251/* 2252 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist 2253 * to the value high for the pageset p. 2254 */ 2255 2256static void setup_pagelist_highmark(struct per_cpu_pageset *p, 2257 unsigned long high) 2258{ 2259 struct per_cpu_pages *pcp; 2260 2261 pcp = &p->pcp[0]; /* hot list */ 2262 pcp->high = high; 2263 pcp->batch = max(1UL, high/4); 2264 if ((high/4) > (PAGE_SHIFT * 8)) 2265 pcp->batch = PAGE_SHIFT * 8; 2266} 2267 2268 2269#ifdef CONFIG_NUMA 2270/* 2271 * Boot pageset table. One per cpu which is going to be used for all 2272 * zones and all nodes. The parameters will be set in such a way 2273 * that an item put on a list will immediately be handed over to 2274 * the buddy list. This is safe since pageset manipulation is done 2275 * with interrupts disabled. 2276 * 2277 * Some NUMA counter updates may also be caught by the boot pagesets. 2278 * 2279 * The boot_pagesets must be kept even after bootup is complete for 2280 * unused processors and/or zones. They do play a role for bootstrapping 2281 * hotplugged processors. 2282 * 2283 * zoneinfo_show() and maybe other functions do 2284 * not check if the processor is online before following the pageset pointer. 2285 * Other parts of the kernel may not check if the zone is available. 2286 */ 2287static struct per_cpu_pageset boot_pageset[NR_CPUS]; 2288 2289/* 2290 * Dynamically allocate memory for the 2291 * per cpu pageset array in struct zone. 2292 */ 2293static int __cpuinit process_zones(int cpu) 2294{ 2295 struct zone *zone, *dzone; 2296 2297 for_each_zone(zone) { 2298 2299 if (!populated_zone(zone)) 2300 continue; 2301 2302 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset), 2303 GFP_KERNEL, cpu_to_node(cpu)); 2304 if (!zone_pcp(zone, cpu)) 2305 goto bad; 2306 2307 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone)); 2308 2309 if (percpu_pagelist_fraction) 2310 setup_pagelist_highmark(zone_pcp(zone, cpu), 2311 (zone->present_pages / percpu_pagelist_fraction)); 2312 } 2313 2314 return 0; 2315bad: 2316 for_each_zone(dzone) { 2317 if (dzone == zone) 2318 break; 2319 kfree(zone_pcp(dzone, cpu)); 2320 zone_pcp(dzone, cpu) = NULL; 2321 } 2322 return -ENOMEM; 2323} 2324 2325static inline void free_zone_pagesets(int cpu) 2326{ 2327 struct zone *zone; 2328 2329 for_each_zone(zone) { 2330 struct per_cpu_pageset *pset = zone_pcp(zone, cpu); 2331 2332 /* Free per_cpu_pageset if it is slab allocated */ 2333 if (pset != &boot_pageset[cpu]) 2334 kfree(pset); 2335 zone_pcp(zone, cpu) = NULL; 2336 } 2337} 2338 2339static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb, 2340 unsigned long action, 2341 void *hcpu) 2342{ 2343 int cpu = (long)hcpu; 2344 int ret = NOTIFY_OK; 2345 2346 switch (action) { 2347 case CPU_UP_PREPARE: 2348 case CPU_UP_PREPARE_FROZEN: 2349 if (process_zones(cpu)) 2350 ret = NOTIFY_BAD; 2351 break; 2352 case CPU_UP_CANCELED: 2353 case CPU_UP_CANCELED_FROZEN: 2354 case CPU_DEAD: 2355 case CPU_DEAD_FROZEN: 2356 free_zone_pagesets(cpu); 2357 break; 2358 default: 2359 break; 2360 } 2361 return ret; 2362} 2363 2364static struct notifier_block __cpuinitdata pageset_notifier = 2365 { &pageset_cpuup_callback, NULL, 0 }; 2366 2367void __init setup_per_cpu_pageset(void) 2368{ 2369 int err; 2370 2371 /* Initialize per_cpu_pageset for cpu 0. 2372 * A cpuup callback will do this for every cpu 2373 * as it comes online 2374 */ 2375 err = process_zones(smp_processor_id()); 2376 BUG_ON(err); 2377 register_cpu_notifier(&pageset_notifier); 2378} 2379 2380#endif 2381 2382static noinline __init_refok 2383int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 2384{ 2385 int i; 2386 struct pglist_data *pgdat = zone->zone_pgdat; 2387 size_t alloc_size; 2388 2389 /* 2390 * The per-page waitqueue mechanism uses hashed waitqueues 2391 * per zone. 2392 */ 2393 zone->wait_table_hash_nr_entries = 2394 wait_table_hash_nr_entries(zone_size_pages); 2395 zone->wait_table_bits = 2396 wait_table_bits(zone->wait_table_hash_nr_entries); 2397 alloc_size = zone->wait_table_hash_nr_entries 2398 * sizeof(wait_queue_head_t); 2399 2400 if (system_state == SYSTEM_BOOTING) { 2401 zone->wait_table = (wait_queue_head_t *) 2402 alloc_bootmem_node(pgdat, alloc_size); 2403 } else { 2404 /* 2405 * This case means that a zone whose size was 0 gets new memory 2406 * via memory hot-add. 2407 * But it may be the case that a new node was hot-added. In 2408 * this case vmalloc() will not be able to use this new node's 2409 * memory - this wait_table must be initialized to use this new 2410 * node itself as well. 2411 * To use this new node's memory, further consideration will be 2412 * necessary. 2413 */ 2414 zone->wait_table = (wait_queue_head_t *)vmalloc(alloc_size); 2415 } 2416 if (!zone->wait_table) 2417 return -ENOMEM; 2418 2419 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i) 2420 init_waitqueue_head(zone->wait_table + i); 2421 2422 return 0; 2423} 2424 2425static __meminit void zone_pcp_init(struct zone *zone) 2426{ 2427 int cpu; 2428 unsigned long batch = zone_batchsize(zone); 2429 2430 for (cpu = 0; cpu < NR_CPUS; cpu++) { 2431#ifdef CONFIG_NUMA 2432 /* Early boot. Slab allocator not functional yet */ 2433 zone_pcp(zone, cpu) = &boot_pageset[cpu]; 2434 setup_pageset(&boot_pageset[cpu],0); 2435#else 2436 setup_pageset(zone_pcp(zone,cpu), batch); 2437#endif 2438 } 2439 if (zone->present_pages) 2440 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", 2441 zone->name, zone->present_pages, batch); 2442} 2443 2444__meminit int init_currently_empty_zone(struct zone *zone, 2445 unsigned long zone_start_pfn, 2446 unsigned long size, 2447 enum memmap_context context) 2448{ 2449 struct pglist_data *pgdat = zone->zone_pgdat; 2450 int ret; 2451 ret = zone_wait_table_init(zone, size); 2452 if (ret) 2453 return ret; 2454 pgdat->nr_zones = zone_idx(zone) + 1; 2455 2456 zone->zone_start_pfn = zone_start_pfn; 2457 2458 memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn); 2459 2460 zone_init_free_lists(pgdat, zone, zone->spanned_pages); 2461 2462 return 0; 2463} 2464 2465#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 2466/* 2467 * Basic iterator support. Return the first range of PFNs for a node 2468 * Note: nid == MAX_NUMNODES returns first region regardless of node 2469 */ 2470static int __meminit first_active_region_index_in_nid(int nid) 2471{ 2472 int i; 2473 2474 for (i = 0; i < nr_nodemap_entries; i++) 2475 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid) 2476 return i; 2477 2478 return -1; 2479} 2480 2481/* 2482 * Basic iterator support. Return the next active range of PFNs for a node 2483 * Note: nid == MAX_NUMNODES returns next region regardles of node 2484 */ 2485static int __meminit next_active_region_index_in_nid(int index, int nid) 2486{ 2487 for (index = index + 1; index < nr_nodemap_entries; index++) 2488 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid) 2489 return index; 2490 2491 return -1; 2492} 2493 2494#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID 2495/* 2496 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. 2497 * Architectures may implement their own version but if add_active_range() 2498 * was used and there are no special requirements, this is a convenient 2499 * alternative 2500 */ 2501int __meminit early_pfn_to_nid(unsigned long pfn) 2502{ 2503 int i; 2504 2505 for (i = 0; i < nr_nodemap_entries; i++) { 2506 unsigned long start_pfn = early_node_map[i].start_pfn; 2507 unsigned long end_pfn = early_node_map[i].end_pfn; 2508 2509 if (start_pfn <= pfn && pfn < end_pfn) 2510 return early_node_map[i].nid; 2511 } 2512 2513 return 0; 2514} 2515#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ 2516 2517/* Basic iterator support to walk early_node_map[] */ 2518#define for_each_active_range_index_in_nid(i, nid) \ 2519 for (i = first_active_region_index_in_nid(nid); i != -1; \ 2520 i = next_active_region_index_in_nid(i, nid)) 2521 2522/** 2523 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range 2524 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. 2525 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node 2526 * 2527 * If an architecture guarantees that all ranges registered with 2528 * add_active_ranges() contain no holes and may be freed, this 2529 * this function may be used instead of calling free_bootmem() manually. 2530 */ 2531void __init free_bootmem_with_active_regions(int nid, 2532 unsigned long max_low_pfn) 2533{ 2534 int i; 2535 2536 for_each_active_range_index_in_nid(i, nid) { 2537 unsigned long size_pages = 0; 2538 unsigned long end_pfn = early_node_map[i].end_pfn; 2539 2540 if (early_node_map[i].start_pfn >= max_low_pfn) 2541 continue; 2542 2543 if (end_pfn > max_low_pfn) 2544 end_pfn = max_low_pfn; 2545 2546 size_pages = end_pfn - early_node_map[i].start_pfn; 2547 free_bootmem_node(NODE_DATA(early_node_map[i].nid), 2548 PFN_PHYS(early_node_map[i].start_pfn), 2549 size_pages << PAGE_SHIFT); 2550 } 2551} 2552 2553/** 2554 * sparse_memory_present_with_active_regions - Call memory_present for each active range 2555 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. 2556 * 2557 * If an architecture guarantees that all ranges registered with 2558 * add_active_ranges() contain no holes and may be freed, this 2559 * function may be used instead of calling memory_present() manually. 2560 */ 2561void __init sparse_memory_present_with_active_regions(int nid) 2562{ 2563 int i; 2564 2565 for_each_active_range_index_in_nid(i, nid) 2566 memory_present(early_node_map[i].nid, 2567 early_node_map[i].start_pfn, 2568 early_node_map[i].end_pfn); 2569} 2570 2571/** 2572 * push_node_boundaries - Push node boundaries to at least the requested boundary 2573 * @nid: The nid of the node to push the boundary for 2574 * @start_pfn: The start pfn of the node 2575 * @end_pfn: The end pfn of the node 2576 * 2577 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd 2578 * time. Specifically, on x86_64, SRAT will report ranges that can potentially 2579 * be hotplugged even though no physical memory exists. This function allows 2580 * an arch to push out the node boundaries so mem_map is allocated that can 2581 * be used later. 2582 */ 2583#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE 2584void __init push_node_boundaries(unsigned int nid, 2585 unsigned long start_pfn, unsigned long end_pfn) 2586{ 2587 printk(KERN_DEBUG "Entering push_node_boundaries(%u, %lu, %lu)\n", 2588 nid, start_pfn, end_pfn); 2589 2590 /* Initialise the boundary for this node if necessary */ 2591 if (node_boundary_end_pfn[nid] == 0) 2592 node_boundary_start_pfn[nid] = -1UL; 2593 2594 /* Update the boundaries */ 2595 if (node_boundary_start_pfn[nid] > start_pfn) 2596 node_boundary_start_pfn[nid] = start_pfn; 2597 if (node_boundary_end_pfn[nid] < end_pfn) 2598 node_boundary_end_pfn[nid] = end_pfn; 2599} 2600 2601/* If necessary, push the node boundary out for reserve hotadd */ 2602static void __meminit account_node_boundary(unsigned int nid, 2603 unsigned long *start_pfn, unsigned long *end_pfn) 2604{ 2605 printk(KERN_DEBUG "Entering account_node_boundary(%u, %lu, %lu)\n", 2606 nid, *start_pfn, *end_pfn); 2607 2608 /* Return if boundary information has not been provided */ 2609 if (node_boundary_end_pfn[nid] == 0) 2610 return; 2611 2612 /* Check the boundaries and update if necessary */ 2613 if (node_boundary_start_pfn[nid] < *start_pfn) 2614 *start_pfn = node_boundary_start_pfn[nid]; 2615 if (node_boundary_end_pfn[nid] > *end_pfn) 2616 *end_pfn = node_boundary_end_pfn[nid]; 2617} 2618#else 2619void __init push_node_boundaries(unsigned int nid, 2620 unsigned long start_pfn, unsigned long end_pfn) {} 2621 2622static void __meminit account_node_boundary(unsigned int nid, 2623 unsigned long *start_pfn, unsigned long *end_pfn) {} 2624#endif 2625 2626 2627/** 2628 * get_pfn_range_for_nid - Return the start and end page frames for a node 2629 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. 2630 * @start_pfn: Passed by reference. On return, it will have the node start_pfn. 2631 * @end_pfn: Passed by reference. On return, it will have the node end_pfn. 2632 * 2633 * It returns the start and end page frame of a node based on information 2634 * provided by an arch calling add_active_range(). If called for a node 2635 * with no available memory, a warning is printed and the start and end 2636 * PFNs will be 0. 2637 */ 2638void __meminit get_pfn_range_for_nid(unsigned int nid, 2639 unsigned long *start_pfn, unsigned long *end_pfn) 2640{ 2641 int i; 2642 *start_pfn = -1UL; 2643 *end_pfn = 0; 2644 2645 for_each_active_range_index_in_nid(i, nid) { 2646 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn); 2647 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn); 2648 } 2649 2650 if (*start_pfn == -1UL) { 2651 printk(KERN_WARNING "Node %u active with no memory\n", nid); 2652 *start_pfn = 0; 2653 } 2654 2655 /* Push the node boundaries out if requested */ 2656 account_node_boundary(nid, start_pfn, end_pfn); 2657} 2658 2659/* 2660 * Return the number of pages a zone spans in a node, including holes 2661 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() 2662 */ 2663static unsigned long __meminit zone_spanned_pages_in_node(int nid, 2664 unsigned long zone_type, 2665 unsigned long *ignored) 2666{ 2667 unsigned long node_start_pfn, node_end_pfn; 2668 unsigned long zone_start_pfn, zone_end_pfn; 2669 2670 /* Get the start and end of the node and zone */ 2671 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 2672 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; 2673 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; 2674 2675 /* Check that this node has pages within the zone's required range */ 2676 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) 2677 return 0; 2678 2679 /* Move the zone boundaries inside the node if necessary */ 2680 zone_end_pfn = min(zone_end_pfn, node_end_pfn); 2681 zone_start_pfn = max(zone_start_pfn, node_start_pfn); 2682 2683 /* Return the spanned pages */ 2684 return zone_end_pfn - zone_start_pfn; 2685} 2686 2687/* 2688 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, 2689 * then all holes in the requested range will be accounted for. 2690 */ 2691unsigned long __meminit __absent_pages_in_range(int nid, 2692 unsigned long range_start_pfn, 2693 unsigned long range_end_pfn) 2694{ 2695 int i = 0; 2696 unsigned long prev_end_pfn = 0, hole_pages = 0; 2697 unsigned long start_pfn; 2698 2699 /* Find the end_pfn of the first active range of pfns in the node */ 2700 i = first_active_region_index_in_nid(nid); 2701 if (i == -1) 2702 return 0; 2703 2704 /* Account for ranges before physical memory on this node */ 2705 if (early_node_map[i].start_pfn > range_start_pfn) 2706 hole_pages = early_node_map[i].start_pfn - range_start_pfn; 2707 2708 prev_end_pfn = early_node_map[i].start_pfn; 2709 2710 /* Find all holes for the zone within the node */ 2711 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) { 2712 2713 /* No need to continue if prev_end_pfn is outside the zone */ 2714 if (prev_end_pfn >= range_end_pfn) 2715 break; 2716 2717 /* Make sure the end of the zone is not within the hole */ 2718 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 2719 prev_end_pfn = max(prev_end_pfn, range_start_pfn); 2720 2721 /* Update the hole size cound and move on */ 2722 if (start_pfn > range_start_pfn) { 2723 BUG_ON(prev_end_pfn > start_pfn); 2724 hole_pages += start_pfn - prev_end_pfn; 2725 } 2726 prev_end_pfn = early_node_map[i].end_pfn; 2727 } 2728 2729 /* Account for ranges past physical memory on this node */ 2730 if (range_end_pfn > prev_end_pfn) 2731 hole_pages += range_end_pfn - 2732 max(range_start_pfn, prev_end_pfn); 2733 2734 return hole_pages; 2735} 2736 2737/** 2738 * absent_pages_in_range - Return number of page frames in holes within a range 2739 * @start_pfn: The start PFN to start searching for holes 2740 * @end_pfn: The end PFN to stop searching for holes 2741 * 2742 * It returns the number of pages frames in memory holes within a range. 2743 */ 2744unsigned long __init absent_pages_in_range(unsigned long start_pfn, 2745 unsigned long end_pfn) 2746{ 2747 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); 2748} 2749 2750/* Return the number of page frames in holes in a zone on a node */ 2751static unsigned long __meminit zone_absent_pages_in_node(int nid, 2752 unsigned long zone_type, 2753 unsigned long *ignored) 2754{ 2755 unsigned long node_start_pfn, node_end_pfn; 2756 unsigned long zone_start_pfn, zone_end_pfn; 2757 2758 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 2759 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type], 2760 node_start_pfn); 2761 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type], 2762 node_end_pfn); 2763 2764 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); 2765} 2766 2767#else 2768static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, 2769 unsigned long zone_type, 2770 unsigned long *zones_size) 2771{ 2772 return zones_size[zone_type]; 2773} 2774 2775static inline unsigned long __meminit zone_absent_pages_in_node(int nid, 2776 unsigned long zone_type, 2777 unsigned long *zholes_size) 2778{ 2779 if (!zholes_size) 2780 return 0; 2781 2782 return zholes_size[zone_type]; 2783} 2784 2785#endif 2786 2787static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, 2788 unsigned long *zones_size, unsigned long *zholes_size) 2789{ 2790 unsigned long realtotalpages, totalpages = 0; 2791 enum zone_type i; 2792 2793 for (i = 0; i < MAX_NR_ZONES; i++) 2794 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i, 2795 zones_size); 2796 pgdat->node_spanned_pages = totalpages; 2797 2798 realtotalpages = totalpages; 2799 for (i = 0; i < MAX_NR_ZONES; i++) 2800 realtotalpages -= 2801 zone_absent_pages_in_node(pgdat->node_id, i, 2802 zholes_size); 2803 pgdat->node_present_pages = realtotalpages; 2804 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, 2805 realtotalpages); 2806} 2807 2808/* 2809 * Set up the zone data structures: 2810 * - mark all pages reserved 2811 * - mark all memory queues empty 2812 * - clear the memory bitmaps 2813 */ 2814static void __meminit free_area_init_core(struct pglist_data *pgdat, 2815 unsigned long *zones_size, unsigned long *zholes_size) 2816{ 2817 enum zone_type j; 2818 int nid = pgdat->node_id; 2819 unsigned long zone_start_pfn = pgdat->node_start_pfn; 2820 int ret; 2821 2822 pgdat_resize_init(pgdat); 2823 pgdat->nr_zones = 0; 2824 init_waitqueue_head(&pgdat->kswapd_wait); 2825 pgdat->kswapd_max_order = 0; 2826 2827 for (j = 0; j < MAX_NR_ZONES; j++) { 2828 struct zone *zone = pgdat->node_zones + j; 2829 unsigned long size, realsize, memmap_pages; 2830 2831 size = zone_spanned_pages_in_node(nid, j, zones_size); 2832 realsize = size - zone_absent_pages_in_node(nid, j, 2833 zholes_size); 2834 2835 /* 2836 * Adjust realsize so that it accounts for how much memory 2837 * is used by this zone for memmap. This affects the watermark 2838 * and per-cpu initialisations 2839 */ 2840 memmap_pages = (size * sizeof(struct page)) >> PAGE_SHIFT; 2841 if (realsize >= memmap_pages) { 2842 realsize -= memmap_pages; 2843 printk(KERN_DEBUG 2844 " %s zone: %lu pages used for memmap\n", 2845 zone_names[j], memmap_pages); 2846 } else 2847 printk(KERN_WARNING 2848 " %s zone: %lu pages exceeds realsize %lu\n", 2849 zone_names[j], memmap_pages, realsize); 2850 2851 /* Account for reserved pages */ 2852 if (j == 0 && realsize > dma_reserve) { 2853 realsize -= dma_reserve; 2854 printk(KERN_DEBUG " %s zone: %lu pages reserved\n", 2855 zone_names[0], dma_reserve); 2856 } 2857 2858 if (!is_highmem_idx(j)) 2859 nr_kernel_pages += realsize; 2860 nr_all_pages += realsize; 2861 2862 zone->spanned_pages = size; 2863 zone->present_pages = realsize; 2864#ifdef CONFIG_NUMA 2865 zone->node = nid; 2866 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio) 2867 / 100; 2868 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100; 2869#endif 2870 zone->name = zone_names[j]; 2871 spin_lock_init(&zone->lock); 2872 spin_lock_init(&zone->lru_lock); 2873 zone_seqlock_init(zone); 2874 zone->zone_pgdat = pgdat; 2875 2876 zone->prev_priority = DEF_PRIORITY; 2877 2878 zone_pcp_init(zone); 2879 INIT_LIST_HEAD(&zone->active_list); 2880 INIT_LIST_HEAD(&zone->inactive_list); 2881 zone->nr_scan_active = 0; 2882 zone->nr_scan_inactive = 0; 2883 zap_zone_vm_stats(zone); 2884 atomic_set(&zone->reclaim_in_progress, 0); 2885 if (!size) 2886 continue; 2887 2888 ret = init_currently_empty_zone(zone, zone_start_pfn, 2889 size, MEMMAP_EARLY); 2890 BUG_ON(ret); 2891 zone_start_pfn += size; 2892 } 2893} 2894 2895static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat) 2896{ 2897 /* Skip empty nodes */ 2898 if (!pgdat->node_spanned_pages) 2899 return; 2900 2901#ifdef CONFIG_FLAT_NODE_MEM_MAP 2902 /* ia64 gets its own node_mem_map, before this, without bootmem */ 2903 if (!pgdat->node_mem_map) { 2904 unsigned long size, start, end; 2905 struct page *map; 2906 2907 /* 2908 * The zone's endpoints aren't required to be MAX_ORDER 2909 * aligned but the node_mem_map endpoints must be in order 2910 * for the buddy allocator to function correctly. 2911 */ 2912 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); 2913 end = pgdat->node_start_pfn + pgdat->node_spanned_pages; 2914 end = ALIGN(end, MAX_ORDER_NR_PAGES); 2915 size = (end - start) * sizeof(struct page); 2916 map = alloc_remap(pgdat->node_id, size); 2917 if (!map) 2918 map = alloc_bootmem_node(pgdat, size); 2919 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); 2920 } 2921#ifndef CONFIG_NEED_MULTIPLE_NODES 2922 /* 2923 * With no DISCONTIG, the global mem_map is just set as node 0's 2924 */ 2925 if (pgdat == NODE_DATA(0)) { 2926 mem_map = NODE_DATA(0)->node_mem_map; 2927#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 2928 if (page_to_pfn(mem_map) != pgdat->node_start_pfn) 2929 mem_map -= pgdat->node_start_pfn; 2930#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 2931 } 2932#endif 2933#endif /* CONFIG_FLAT_NODE_MEM_MAP */ 2934} 2935 2936void __meminit free_area_init_node(int nid, struct pglist_data *pgdat, 2937 unsigned long *zones_size, unsigned long node_start_pfn, 2938 unsigned long *zholes_size) 2939{ 2940 pgdat->node_id = nid; 2941 pgdat->node_start_pfn = node_start_pfn; 2942 calculate_node_totalpages(pgdat, zones_size, zholes_size); 2943 2944 alloc_node_mem_map(pgdat); 2945 2946 free_area_init_core(pgdat, zones_size, zholes_size); 2947} 2948 2949#ifdef CONFIG_ARCH_POPULATES_NODE_MAP 2950 2951#if MAX_NUMNODES > 1 2952/* 2953 * Figure out the number of possible node ids. 2954 */ 2955static void __init setup_nr_node_ids(void) 2956{ 2957 unsigned int node; 2958 unsigned int highest = 0; 2959 2960 for_each_node_mask(node, node_possible_map) 2961 highest = node; 2962 nr_node_ids = highest + 1; 2963} 2964#else 2965static inline void setup_nr_node_ids(void) 2966{ 2967} 2968#endif 2969 2970/** 2971 * add_active_range - Register a range of PFNs backed by physical memory 2972 * @nid: The node ID the range resides on 2973 * @start_pfn: The start PFN of the available physical memory 2974 * @end_pfn: The end PFN of the available physical memory 2975 * 2976 * These ranges are stored in an early_node_map[] and later used by 2977 * free_area_init_nodes() to calculate zone sizes and holes. If the 2978 * range spans a memory hole, it is up to the architecture to ensure 2979 * the memory is not freed by the bootmem allocator. If possible 2980 * the range being registered will be merged with existing ranges. 2981 */ 2982void __init add_active_range(unsigned int nid, unsigned long start_pfn, 2983 unsigned long end_pfn) 2984{ 2985 int i; 2986 2987 printk(KERN_DEBUG "Entering add_active_range(%d, %lu, %lu) " 2988 "%d entries of %d used\n", 2989 nid, start_pfn, end_pfn, 2990 nr_nodemap_entries, MAX_ACTIVE_REGIONS); 2991 2992 /* Merge with existing active regions if possible */ 2993 for (i = 0; i < nr_nodemap_entries; i++) { 2994 if (early_node_map[i].nid != nid) 2995 continue; 2996 2997 /* Skip if an existing region covers this new one */ 2998 if (start_pfn >= early_node_map[i].start_pfn && 2999 end_pfn <= early_node_map[i].end_pfn) 3000 return; 3001 3002 /* Merge forward if suitable */ 3003 if (start_pfn <= early_node_map[i].end_pfn && 3004 end_pfn > early_node_map[i].end_pfn) { 3005 early_node_map[i].end_pfn = end_pfn; 3006 return; 3007 } 3008 3009 /* Merge backward if suitable */ 3010 if (start_pfn < early_node_map[i].end_pfn && 3011 end_pfn >= early_node_map[i].start_pfn) { 3012 early_node_map[i].start_pfn = start_pfn; 3013 return; 3014 } 3015 } 3016 3017 /* Check that early_node_map is large enough */ 3018 if (i >= MAX_ACTIVE_REGIONS) { 3019 printk(KERN_CRIT "More than %d memory regions, truncating\n", 3020 MAX_ACTIVE_REGIONS); 3021 return; 3022 } 3023 3024 early_node_map[i].nid = nid; 3025 early_node_map[i].start_pfn = start_pfn; 3026 early_node_map[i].end_pfn = end_pfn; 3027 nr_nodemap_entries = i + 1; 3028} 3029 3030/** 3031 * shrink_active_range - Shrink an existing registered range of PFNs 3032 * @nid: The node id the range is on that should be shrunk 3033 * @old_end_pfn: The old end PFN of the range 3034 * @new_end_pfn: The new PFN of the range 3035 * 3036 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node. 3037 * The map is kept at the end physical page range that has already been 3038 * registered with add_active_range(). This function allows an arch to shrink 3039 * an existing registered range. 3040 */ 3041void __init shrink_active_range(unsigned int nid, unsigned long old_end_pfn, 3042 unsigned long new_end_pfn) 3043{ 3044 int i; 3045 3046 /* Find the old active region end and shrink */ 3047 for_each_active_range_index_in_nid(i, nid) 3048 if (early_node_map[i].end_pfn == old_end_pfn) { 3049 early_node_map[i].end_pfn = new_end_pfn; 3050 break; 3051 } 3052} 3053 3054/** 3055 * remove_all_active_ranges - Remove all currently registered regions 3056 * 3057 * During discovery, it may be found that a table like SRAT is invalid 3058 * and an alternative discovery method must be used. This function removes 3059 * all currently registered regions. 3060 */ 3061void __init remove_all_active_ranges(void) 3062{ 3063 memset(early_node_map, 0, sizeof(early_node_map)); 3064 nr_nodemap_entries = 0; 3065#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE 3066 memset(node_boundary_start_pfn, 0, sizeof(node_boundary_start_pfn)); 3067 memset(node_boundary_end_pfn, 0, sizeof(node_boundary_end_pfn)); 3068#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */ 3069} 3070 3071/* Compare two active node_active_regions */ 3072static int __init cmp_node_active_region(const void *a, const void *b) 3073{ 3074 struct node_active_region *arange = (struct node_active_region *)a; 3075 struct node_active_region *brange = (struct node_active_region *)b; 3076 3077 /* Done this way to avoid overflows */ 3078 if (arange->start_pfn > brange->start_pfn) 3079 return 1; 3080 if (arange->start_pfn < brange->start_pfn) 3081 return -1; 3082 3083 return 0; 3084} 3085 3086/* sort the node_map by start_pfn */ 3087static void __init sort_node_map(void) 3088{ 3089 sort(early_node_map, (size_t)nr_nodemap_entries, 3090 sizeof(struct node_active_region), 3091 cmp_node_active_region, NULL); 3092} 3093 3094/* Find the lowest pfn for a node */ 3095unsigned long __init find_min_pfn_for_node(unsigned long nid) 3096{ 3097 int i; 3098 unsigned long min_pfn = ULONG_MAX; 3099 3100 /* Assuming a sorted map, the first range found has the starting pfn */ 3101 for_each_active_range_index_in_nid(i, nid) 3102 min_pfn = min(min_pfn, early_node_map[i].start_pfn); 3103 3104 if (min_pfn == ULONG_MAX) { 3105 printk(KERN_WARNING 3106 "Could not find start_pfn for node %lu\n", nid); 3107 return 0; 3108 } 3109 3110 return min_pfn; 3111} 3112 3113/** 3114 * find_min_pfn_with_active_regions - Find the minimum PFN registered 3115 * 3116 * It returns the minimum PFN based on information provided via 3117 * add_active_range(). 3118 */ 3119unsigned long __init find_min_pfn_with_active_regions(void) 3120{ 3121 return find_min_pfn_for_node(MAX_NUMNODES); 3122} 3123 3124/** 3125 * find_max_pfn_with_active_regions - Find the maximum PFN registered 3126 * 3127 * It returns the maximum PFN based on information provided via 3128 * add_active_range(). 3129 */ 3130unsigned long __init find_max_pfn_with_active_regions(void) 3131{ 3132 int i; 3133 unsigned long max_pfn = 0; 3134 3135 for (i = 0; i < nr_nodemap_entries; i++) 3136 max_pfn = max(max_pfn, early_node_map[i].end_pfn); 3137 3138 return max_pfn; 3139} 3140 3141/** 3142 * free_area_init_nodes - Initialise all pg_data_t and zone data 3143 * @max_zone_pfn: an array of max PFNs for each zone 3144 * 3145 * This will call free_area_init_node() for each active node in the system. 3146 * Using the page ranges provided by add_active_range(), the size of each 3147 * zone in each node and their holes is calculated. If the maximum PFN 3148 * between two adjacent zones match, it is assumed that the zone is empty. 3149 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed 3150 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone 3151 * starts where the previous one ended. For example, ZONE_DMA32 starts 3152 * at arch_max_dma_pfn. 3153 */ 3154void __init free_area_init_nodes(unsigned long *max_zone_pfn) 3155{ 3156 unsigned long nid; 3157 enum zone_type i; 3158 3159 /* Sort early_node_map as initialisation assumes it is sorted */ 3160 sort_node_map(); 3161 3162 /* Record where the zone boundaries are */ 3163 memset(arch_zone_lowest_possible_pfn, 0, 3164 sizeof(arch_zone_lowest_possible_pfn)); 3165 memset(arch_zone_highest_possible_pfn, 0, 3166 sizeof(arch_zone_highest_possible_pfn)); 3167 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); 3168 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; 3169 for (i = 1; i < MAX_NR_ZONES; i++) { 3170 arch_zone_lowest_possible_pfn[i] = 3171 arch_zone_highest_possible_pfn[i-1]; 3172 arch_zone_highest_possible_pfn[i] = 3173 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); 3174 } 3175 3176 /* Print out the zone ranges */ 3177 printk("Zone PFN ranges:\n"); 3178 for (i = 0; i < MAX_NR_ZONES; i++) 3179 printk(" %-8s %8lu -> %8lu\n", 3180 zone_names[i], 3181 arch_zone_lowest_possible_pfn[i], 3182 arch_zone_highest_possible_pfn[i]); 3183 3184 /* Print out the early_node_map[] */ 3185 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries); 3186 for (i = 0; i < nr_nodemap_entries; i++) 3187 printk(" %3d: %8lu -> %8lu\n", early_node_map[i].nid, 3188 early_node_map[i].start_pfn, 3189 early_node_map[i].end_pfn); 3190 3191 /* Initialise every node */ 3192 setup_nr_node_ids(); 3193 for_each_online_node(nid) { 3194 pg_data_t *pgdat = NODE_DATA(nid); 3195 free_area_init_node(nid, pgdat, NULL, 3196 find_min_pfn_for_node(nid), NULL); 3197 } 3198} 3199#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 3200 3201/** 3202 * set_dma_reserve - set the specified number of pages reserved in the first zone 3203 * @new_dma_reserve: The number of pages to mark reserved 3204 * 3205 * The per-cpu batchsize and zone watermarks are determined by present_pages. 3206 * In the DMA zone, a significant percentage may be consumed by kernel image 3207 * and other unfreeable allocations which can skew the watermarks badly. This 3208 * function may optionally be used to account for unfreeable pages in the 3209 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and 3210 * smaller per-cpu batchsize. 3211 */ 3212void __init set_dma_reserve(unsigned long new_dma_reserve) 3213{ 3214 dma_reserve = new_dma_reserve; 3215} 3216 3217#ifndef CONFIG_NEED_MULTIPLE_NODES 3218static bootmem_data_t contig_bootmem_data; 3219struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data }; 3220 3221EXPORT_SYMBOL(contig_page_data); 3222#endif 3223 3224void __init free_area_init(unsigned long *zones_size) 3225{ 3226 free_area_init_node(0, NODE_DATA(0), zones_size, 3227 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 3228} 3229 3230static int page_alloc_cpu_notify(struct notifier_block *self, 3231 unsigned long action, void *hcpu) 3232{ 3233 int cpu = (unsigned long)hcpu; 3234 3235 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { 3236 local_irq_disable(); 3237 __drain_pages(cpu); 3238 vm_events_fold_cpu(cpu); 3239 local_irq_enable(); 3240 refresh_cpu_vm_stats(cpu); 3241 } 3242 return NOTIFY_OK; 3243} 3244 3245void __init page_alloc_init(void) 3246{ 3247 hotcpu_notifier(page_alloc_cpu_notify, 0); 3248} 3249 3250/* 3251 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio 3252 * or min_free_kbytes changes. 3253 */ 3254static void calculate_totalreserve_pages(void) 3255{ 3256 struct pglist_data *pgdat; 3257 unsigned long reserve_pages = 0; 3258 enum zone_type i, j; 3259 3260 for_each_online_pgdat(pgdat) { 3261 for (i = 0; i < MAX_NR_ZONES; i++) { 3262 struct zone *zone = pgdat->node_zones + i; 3263 unsigned long max = 0; 3264 3265 /* Find valid and maximum lowmem_reserve in the zone */ 3266 for (j = i; j < MAX_NR_ZONES; j++) { 3267 if (zone->lowmem_reserve[j] > max) 3268 max = zone->lowmem_reserve[j]; 3269 } 3270 3271 /* we treat pages_high as reserved pages. */ 3272 max += zone->pages_high; 3273 3274 if (max > zone->present_pages) 3275 max = zone->present_pages; 3276 reserve_pages += max; 3277 } 3278 } 3279 totalreserve_pages = reserve_pages; 3280} 3281 3282/* 3283 * setup_per_zone_lowmem_reserve - called whenever 3284 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 3285 * has a correct pages reserved value, so an adequate number of 3286 * pages are left in the zone after a successful __alloc_pages(). 3287 */ 3288static void setup_per_zone_lowmem_reserve(void) 3289{ 3290 struct pglist_data *pgdat; 3291 enum zone_type j, idx; 3292 3293 for_each_online_pgdat(pgdat) { 3294 for (j = 0; j < MAX_NR_ZONES; j++) { 3295 struct zone *zone = pgdat->node_zones + j; 3296 unsigned long present_pages = zone->present_pages; 3297 3298 zone->lowmem_reserve[j] = 0; 3299 3300 idx = j; 3301 while (idx) { 3302 struct zone *lower_zone; 3303 3304 idx--; 3305 3306 if (sysctl_lowmem_reserve_ratio[idx] < 1) 3307 sysctl_lowmem_reserve_ratio[idx] = 1; 3308 3309 lower_zone = pgdat->node_zones + idx; 3310 lower_zone->lowmem_reserve[j] = present_pages / 3311 sysctl_lowmem_reserve_ratio[idx]; 3312 present_pages += lower_zone->present_pages; 3313 } 3314 } 3315 } 3316 3317 /* update totalreserve_pages */ 3318 calculate_totalreserve_pages(); 3319} 3320 3321/** 3322 * setup_per_zone_pages_min - called when min_free_kbytes changes. 3323 * 3324 * Ensures that the pages_{min,low,high} values for each zone are set correctly 3325 * with respect to min_free_kbytes. 3326 */ 3327void setup_per_zone_pages_min(void) 3328{ 3329 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 3330 unsigned long lowmem_pages = 0; 3331 struct zone *zone; 3332 unsigned long flags; 3333 3334 /* Calculate total number of !ZONE_HIGHMEM pages */ 3335 for_each_zone(zone) { 3336 if (!is_highmem(zone)) 3337 lowmem_pages += zone->present_pages; 3338 } 3339 3340 for_each_zone(zone) { 3341 u64 tmp; 3342 3343 spin_lock_irqsave(&zone->lru_lock, flags); 3344 tmp = (u64)pages_min * zone->present_pages; 3345 do_div(tmp, lowmem_pages); 3346 if (is_highmem(zone)) { 3347 /* 3348 * __GFP_HIGH and PF_MEMALLOC allocations usually don't 3349 * need highmem pages, so cap pages_min to a small 3350 * value here. 3351 * 3352 * The (pages_high-pages_low) and (pages_low-pages_min) 3353 * deltas controls asynch page reclaim, and so should 3354 * not be capped for highmem. 3355 */ 3356 int min_pages; 3357 3358 min_pages = zone->present_pages / 1024; 3359 if (min_pages < SWAP_CLUSTER_MAX) 3360 min_pages = SWAP_CLUSTER_MAX; 3361 if (min_pages > 128) 3362 min_pages = 128; 3363 zone->pages_min = min_pages; 3364 } else { 3365 /* 3366 * If it's a lowmem zone, reserve a number of pages 3367 * proportionate to the zone's size. 3368 */ 3369 zone->pages_min = tmp; 3370 } 3371 3372 zone->pages_low = zone->pages_min + (tmp >> 2); 3373 zone->pages_high = zone->pages_min + (tmp >> 1); 3374 spin_unlock_irqrestore(&zone->lru_lock, flags); 3375 } 3376 3377 /* update totalreserve_pages */ 3378 calculate_totalreserve_pages(); 3379} 3380 3381/* 3382 * Initialise min_free_kbytes. 3383 * 3384 * For small machines we want it small (128k min). For large machines 3385 * we want it large (64MB max). But it is not linear, because network 3386 * bandwidth does not increase linearly with machine size. We use 3387 * 3388 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 3389 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 3390 * 3391 * which yields 3392 * 3393 * 16MB: 512k 3394 * 32MB: 724k 3395 * 64MB: 1024k 3396 * 128MB: 1448k 3397 * 256MB: 2048k 3398 * 512MB: 2896k 3399 * 1024MB: 4096k 3400 * 2048MB: 5792k 3401 * 4096MB: 8192k 3402 * 8192MB: 11584k 3403 * 16384MB: 16384k 3404 */ 3405static int __init init_per_zone_pages_min(void) 3406{ 3407 unsigned long lowmem_kbytes; 3408 3409 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 3410 3411 min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 3412 if (min_free_kbytes < 128) 3413 min_free_kbytes = 128; 3414 if (min_free_kbytes > 65536) 3415 min_free_kbytes = 65536; 3416 setup_per_zone_pages_min(); 3417 setup_per_zone_lowmem_reserve(); 3418 return 0; 3419} 3420module_init(init_per_zone_pages_min) 3421 3422/* 3423 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 3424 * that we can call two helper functions whenever min_free_kbytes 3425 * changes. 3426 */ 3427int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 3428 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 3429{ 3430 proc_dointvec(table, write, file, buffer, length, ppos); 3431 if (write) 3432 setup_per_zone_pages_min(); 3433 return 0; 3434} 3435 3436#ifdef CONFIG_NUMA 3437int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, 3438 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 3439{ 3440 struct zone *zone; 3441 int rc; 3442 3443 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 3444 if (rc) 3445 return rc; 3446 3447 for_each_zone(zone) 3448 zone->min_unmapped_pages = (zone->present_pages * 3449 sysctl_min_unmapped_ratio) / 100; 3450 return 0; 3451} 3452 3453int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write, 3454 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 3455{ 3456 struct zone *zone; 3457 int rc; 3458 3459 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 3460 if (rc) 3461 return rc; 3462 3463 for_each_zone(zone) 3464 zone->min_slab_pages = (zone->present_pages * 3465 sysctl_min_slab_ratio) / 100; 3466 return 0; 3467} 3468#endif 3469 3470/* 3471 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 3472 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 3473 * whenever sysctl_lowmem_reserve_ratio changes. 3474 * 3475 * The reserve ratio obviously has absolutely no relation with the 3476 * pages_min watermarks. The lowmem reserve ratio can only make sense 3477 * if in function of the boot time zone sizes. 3478 */ 3479int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, 3480 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 3481{ 3482 proc_dointvec_minmax(table, write, file, buffer, length, ppos); 3483 setup_per_zone_lowmem_reserve(); 3484 return 0; 3485} 3486 3487/* 3488 * percpu_pagelist_fraction - changes the pcp->high for each zone on each 3489 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist 3490 * can have before it gets flushed back to buddy allocator. 3491 */ 3492 3493int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, 3494 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 3495{ 3496 struct zone *zone; 3497 unsigned int cpu; 3498 int ret; 3499 3500 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 3501 if (!write || (ret == -EINVAL)) 3502 return ret; 3503 for_each_zone(zone) { 3504 for_each_online_cpu(cpu) { 3505 unsigned long high; 3506 high = zone->present_pages / percpu_pagelist_fraction; 3507 setup_pagelist_highmark(zone_pcp(zone, cpu), high); 3508 } 3509 } 3510 return 0; 3511} 3512 3513int hashdist = HASHDIST_DEFAULT; 3514 3515#ifdef CONFIG_NUMA 3516static int __init set_hashdist(char *str) 3517{ 3518 if (!str) 3519 return 0; 3520 hashdist = simple_strtoul(str, &str, 0); 3521 return 1; 3522} 3523__setup("hashdist=", set_hashdist); 3524#endif 3525 3526/* 3527 * allocate a large system hash table from bootmem 3528 * - it is assumed that the hash table must contain an exact power-of-2 3529 * quantity of entries 3530 * - limit is the number of hash buckets, not the total allocation size 3531 */ 3532void *__init alloc_large_system_hash(const char *tablename, 3533 unsigned long bucketsize, 3534 unsigned long numentries, 3535 int scale, 3536 int flags, 3537 unsigned int *_hash_shift, 3538 unsigned int *_hash_mask, 3539 unsigned long limit) 3540{ 3541 unsigned long long max = limit; 3542 unsigned long log2qty, size; 3543 void *table = NULL; 3544 3545 /* allow the kernel cmdline to have a say */ 3546 if (!numentries) { 3547 /* round applicable memory size up to nearest megabyte */ 3548 numentries = nr_kernel_pages; 3549 numentries += (1UL << (20 - PAGE_SHIFT)) - 1; 3550 numentries >>= 20 - PAGE_SHIFT; 3551 numentries <<= 20 - PAGE_SHIFT; 3552 3553 /* limit to 1 bucket per 2^scale bytes of low memory */ 3554 if (scale > PAGE_SHIFT) 3555 numentries >>= (scale - PAGE_SHIFT); 3556 else 3557 numentries <<= (PAGE_SHIFT - scale); 3558 3559 /* Make sure we've got at least a 0-order allocation.. */ 3560 if (unlikely((numentries * bucketsize) < PAGE_SIZE)) 3561 numentries = PAGE_SIZE / bucketsize; 3562 } 3563 numentries = roundup_pow_of_two(numentries); 3564 3565 /* limit allocation size to 1/16 total memory by default */ 3566 if (max == 0) { 3567 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 3568 do_div(max, bucketsize); 3569 } 3570 3571 if (numentries > max) 3572 numentries = max; 3573 3574 log2qty = ilog2(numentries); 3575 3576 do { 3577 size = bucketsize << log2qty; 3578 if (flags & HASH_EARLY) 3579 table = alloc_bootmem(size); 3580 else if (hashdist) 3581 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 3582 else { 3583 unsigned long order; 3584 for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++) 3585 ; 3586 table = (void*) __get_free_pages(GFP_ATOMIC, order); 3587 /* 3588 * If bucketsize is not a power-of-two, we may free 3589 * some pages at the end of hash table. 3590 */ 3591 if (table) { 3592 unsigned long alloc_end = (unsigned long)table + 3593 (PAGE_SIZE << order); 3594 unsigned long used = (unsigned long)table + 3595 PAGE_ALIGN(size); 3596 split_page(virt_to_page(table), order); 3597 while (used < alloc_end) { 3598 free_page(used); 3599 used += PAGE_SIZE; 3600 } 3601 } 3602 } 3603 } while (!table && size > PAGE_SIZE && --log2qty); 3604 3605 if (!table) 3606 panic("Failed to allocate %s hash table\n", tablename); 3607 3608 printk("%s hash table entries: %d (order: %d, %lu bytes)\n", 3609 tablename, 3610 (1U << log2qty), 3611 ilog2(size) - PAGE_SHIFT, 3612 size); 3613 3614 if (_hash_shift) 3615 *_hash_shift = log2qty; 3616 if (_hash_mask) 3617 *_hash_mask = (1 << log2qty) - 1; 3618 3619 return table; 3620} 3621 3622#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE 3623struct page *pfn_to_page(unsigned long pfn) 3624{ 3625 return __pfn_to_page(pfn); 3626} 3627unsigned long page_to_pfn(struct page *page) 3628{ 3629 return __page_to_pfn(page); 3630} 3631EXPORT_SYMBOL(pfn_to_page); 3632EXPORT_SYMBOL(page_to_pfn); 3633#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */ 3634 3635 3636