page_alloc.c revision 3947be1969a9ce455ec30f60ef51efb10e4323d1
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/config.h> 18#include <linux/stddef.h> 19#include <linux/mm.h> 20#include <linux/swap.h> 21#include <linux/interrupt.h> 22#include <linux/pagemap.h> 23#include <linux/bootmem.h> 24#include <linux/compiler.h> 25#include <linux/kernel.h> 26#include <linux/module.h> 27#include <linux/suspend.h> 28#include <linux/pagevec.h> 29#include <linux/blkdev.h> 30#include <linux/slab.h> 31#include <linux/notifier.h> 32#include <linux/topology.h> 33#include <linux/sysctl.h> 34#include <linux/cpu.h> 35#include <linux/cpuset.h> 36#include <linux/memory_hotplug.h> 37#include <linux/nodemask.h> 38#include <linux/vmalloc.h> 39 40#include <asm/tlbflush.h> 41#include "internal.h" 42 43/* 44 * MCD - HACK: Find somewhere to initialize this EARLY, or make this 45 * initializer cleaner 46 */ 47nodemask_t node_online_map __read_mostly = { { [0] = 1UL } }; 48EXPORT_SYMBOL(node_online_map); 49nodemask_t node_possible_map __read_mostly = NODE_MASK_ALL; 50EXPORT_SYMBOL(node_possible_map); 51struct pglist_data *pgdat_list __read_mostly; 52unsigned long totalram_pages __read_mostly; 53unsigned long totalhigh_pages __read_mostly; 54long nr_swap_pages; 55 56/* 57 * results with 256, 32 in the lowmem_reserve sysctl: 58 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) 59 * 1G machine -> (16M dma, 784M normal, 224M high) 60 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA 61 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL 62 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA 63 */ 64int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 256, 32 }; 65 66EXPORT_SYMBOL(totalram_pages); 67EXPORT_SYMBOL(nr_swap_pages); 68 69/* 70 * Used by page_zone() to look up the address of the struct zone whose 71 * id is encoded in the upper bits of page->flags 72 */ 73struct zone *zone_table[1 << ZONETABLE_SHIFT] __read_mostly; 74EXPORT_SYMBOL(zone_table); 75 76static char *zone_names[MAX_NR_ZONES] = { "DMA", "Normal", "HighMem" }; 77int min_free_kbytes = 1024; 78 79unsigned long __initdata nr_kernel_pages; 80unsigned long __initdata nr_all_pages; 81 82static int page_outside_zone_boundaries(struct zone *zone, struct page *page) 83{ 84 int ret = 0; 85 unsigned seq; 86 unsigned long pfn = page_to_pfn(page); 87 88 do { 89 seq = zone_span_seqbegin(zone); 90 if (pfn >= zone->zone_start_pfn + zone->spanned_pages) 91 ret = 1; 92 else if (pfn < zone->zone_start_pfn) 93 ret = 1; 94 } while (zone_span_seqretry(zone, seq)); 95 96 return ret; 97} 98 99static int page_is_consistent(struct zone *zone, struct page *page) 100{ 101#ifdef CONFIG_HOLES_IN_ZONE 102 if (!pfn_valid(page_to_pfn(page))) 103 return 0; 104#endif 105 if (zone != page_zone(page)) 106 return 0; 107 108 return 1; 109} 110/* 111 * Temporary debugging check for pages not lying within a given zone. 112 */ 113static int bad_range(struct zone *zone, struct page *page) 114{ 115 if (page_outside_zone_boundaries(zone, page)) 116 return 1; 117 if (!page_is_consistent(zone, page)) 118 return 1; 119 120 return 0; 121} 122 123static void bad_page(const char *function, struct page *page) 124{ 125 printk(KERN_EMERG "Bad page state at %s (in process '%s', page %p)\n", 126 function, current->comm, page); 127 printk(KERN_EMERG "flags:0x%0*lx mapping:%p mapcount:%d count:%d\n", 128 (int)(2*sizeof(page_flags_t)), (unsigned long)page->flags, 129 page->mapping, page_mapcount(page), page_count(page)); 130 printk(KERN_EMERG "Backtrace:\n"); 131 dump_stack(); 132 printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n"); 133 page->flags &= ~(1 << PG_lru | 134 1 << PG_private | 135 1 << PG_locked | 136 1 << PG_active | 137 1 << PG_dirty | 138 1 << PG_reclaim | 139 1 << PG_slab | 140 1 << PG_swapcache | 141 1 << PG_writeback | 142 1 << PG_reserved ); 143 set_page_count(page, 0); 144 reset_page_mapcount(page); 145 page->mapping = NULL; 146 add_taint(TAINT_BAD_PAGE); 147} 148 149#ifndef CONFIG_HUGETLB_PAGE 150#define prep_compound_page(page, order) do { } while (0) 151#define destroy_compound_page(page, order) do { } while (0) 152#else 153/* 154 * Higher-order pages are called "compound pages". They are structured thusly: 155 * 156 * The first PAGE_SIZE page is called the "head page". 157 * 158 * The remaining PAGE_SIZE pages are called "tail pages". 159 * 160 * All pages have PG_compound set. All pages have their ->private pointing at 161 * the head page (even the head page has this). 162 * 163 * The first tail page's ->mapping, if non-zero, holds the address of the 164 * compound page's put_page() function. 165 * 166 * The order of the allocation is stored in the first tail page's ->index 167 * This is only for debug at present. This usage means that zero-order pages 168 * may not be compound. 169 */ 170static void prep_compound_page(struct page *page, unsigned long order) 171{ 172 int i; 173 int nr_pages = 1 << order; 174 175 page[1].mapping = NULL; 176 page[1].index = order; 177 for (i = 0; i < nr_pages; i++) { 178 struct page *p = page + i; 179 180 SetPageCompound(p); 181 set_page_private(p, (unsigned long)page); 182 } 183} 184 185static void destroy_compound_page(struct page *page, unsigned long order) 186{ 187 int i; 188 int nr_pages = 1 << order; 189 190 if (!PageCompound(page)) 191 return; 192 193 if (page[1].index != order) 194 bad_page(__FUNCTION__, page); 195 196 for (i = 0; i < nr_pages; i++) { 197 struct page *p = page + i; 198 199 if (!PageCompound(p)) 200 bad_page(__FUNCTION__, page); 201 if (page_private(p) != (unsigned long)page) 202 bad_page(__FUNCTION__, page); 203 ClearPageCompound(p); 204 } 205} 206#endif /* CONFIG_HUGETLB_PAGE */ 207 208/* 209 * function for dealing with page's order in buddy system. 210 * zone->lock is already acquired when we use these. 211 * So, we don't need atomic page->flags operations here. 212 */ 213static inline unsigned long page_order(struct page *page) { 214 return page_private(page); 215} 216 217static inline void set_page_order(struct page *page, int order) { 218 set_page_private(page, order); 219 __SetPagePrivate(page); 220} 221 222static inline void rmv_page_order(struct page *page) 223{ 224 __ClearPagePrivate(page); 225 set_page_private(page, 0); 226} 227 228/* 229 * Locate the struct page for both the matching buddy in our 230 * pair (buddy1) and the combined O(n+1) page they form (page). 231 * 232 * 1) Any buddy B1 will have an order O twin B2 which satisfies 233 * the following equation: 234 * B2 = B1 ^ (1 << O) 235 * For example, if the starting buddy (buddy2) is #8 its order 236 * 1 buddy is #10: 237 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 238 * 239 * 2) Any buddy B will have an order O+1 parent P which 240 * satisfies the following equation: 241 * P = B & ~(1 << O) 242 * 243 * Assumption: *_mem_map is contigious at least up to MAX_ORDER 244 */ 245static inline struct page * 246__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order) 247{ 248 unsigned long buddy_idx = page_idx ^ (1 << order); 249 250 return page + (buddy_idx - page_idx); 251} 252 253static inline unsigned long 254__find_combined_index(unsigned long page_idx, unsigned int order) 255{ 256 return (page_idx & ~(1 << order)); 257} 258 259/* 260 * This function checks whether a page is free && is the buddy 261 * we can do coalesce a page and its buddy if 262 * (a) the buddy is free && 263 * (b) the buddy is on the buddy system && 264 * (c) a page and its buddy have the same order. 265 * for recording page's order, we use page_private(page) and PG_private. 266 * 267 */ 268static inline int page_is_buddy(struct page *page, int order) 269{ 270 if (PagePrivate(page) && 271 (page_order(page) == order) && 272 page_count(page) == 0) 273 return 1; 274 return 0; 275} 276 277/* 278 * Freeing function for a buddy system allocator. 279 * 280 * The concept of a buddy system is to maintain direct-mapped table 281 * (containing bit values) for memory blocks of various "orders". 282 * The bottom level table contains the map for the smallest allocatable 283 * units of memory (here, pages), and each level above it describes 284 * pairs of units from the levels below, hence, "buddies". 285 * At a high level, all that happens here is marking the table entry 286 * at the bottom level available, and propagating the changes upward 287 * as necessary, plus some accounting needed to play nicely with other 288 * parts of the VM system. 289 * At each level, we keep a list of pages, which are heads of continuous 290 * free pages of length of (1 << order) and marked with PG_Private.Page's 291 * order is recorded in page_private(page) field. 292 * So when we are allocating or freeing one, we can derive the state of the 293 * other. That is, if we allocate a small block, and both were 294 * free, the remainder of the region must be split into blocks. 295 * If a block is freed, and its buddy is also free, then this 296 * triggers coalescing into a block of larger size. 297 * 298 * -- wli 299 */ 300 301static inline void __free_pages_bulk (struct page *page, 302 struct zone *zone, unsigned int order) 303{ 304 unsigned long page_idx; 305 int order_size = 1 << order; 306 307 if (unlikely(order)) 308 destroy_compound_page(page, order); 309 310 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); 311 312 BUG_ON(page_idx & (order_size - 1)); 313 BUG_ON(bad_range(zone, page)); 314 315 zone->free_pages += order_size; 316 while (order < MAX_ORDER-1) { 317 unsigned long combined_idx; 318 struct free_area *area; 319 struct page *buddy; 320 321 combined_idx = __find_combined_index(page_idx, order); 322 buddy = __page_find_buddy(page, page_idx, order); 323 324 if (bad_range(zone, buddy)) 325 break; 326 if (!page_is_buddy(buddy, order)) 327 break; /* Move the buddy up one level. */ 328 list_del(&buddy->lru); 329 area = zone->free_area + order; 330 area->nr_free--; 331 rmv_page_order(buddy); 332 page = page + (combined_idx - page_idx); 333 page_idx = combined_idx; 334 order++; 335 } 336 set_page_order(page, order); 337 list_add(&page->lru, &zone->free_area[order].free_list); 338 zone->free_area[order].nr_free++; 339} 340 341static inline void free_pages_check(const char *function, struct page *page) 342{ 343 if ( page_mapcount(page) || 344 page->mapping != NULL || 345 page_count(page) != 0 || 346 (page->flags & ( 347 1 << PG_lru | 348 1 << PG_private | 349 1 << PG_locked | 350 1 << PG_active | 351 1 << PG_reclaim | 352 1 << PG_slab | 353 1 << PG_swapcache | 354 1 << PG_writeback | 355 1 << PG_reserved ))) 356 bad_page(function, page); 357 if (PageDirty(page)) 358 __ClearPageDirty(page); 359} 360 361/* 362 * Frees a list of pages. 363 * Assumes all pages on list are in same zone, and of same order. 364 * count is the number of pages to free. 365 * 366 * If the zone was previously in an "all pages pinned" state then look to 367 * see if this freeing clears that state. 368 * 369 * And clear the zone's pages_scanned counter, to hold off the "all pages are 370 * pinned" detection logic. 371 */ 372static int 373free_pages_bulk(struct zone *zone, int count, 374 struct list_head *list, unsigned int order) 375{ 376 unsigned long flags; 377 struct page *page = NULL; 378 int ret = 0; 379 380 spin_lock_irqsave(&zone->lock, flags); 381 zone->all_unreclaimable = 0; 382 zone->pages_scanned = 0; 383 while (!list_empty(list) && count--) { 384 page = list_entry(list->prev, struct page, lru); 385 /* have to delete it as __free_pages_bulk list manipulates */ 386 list_del(&page->lru); 387 __free_pages_bulk(page, zone, order); 388 ret++; 389 } 390 spin_unlock_irqrestore(&zone->lock, flags); 391 return ret; 392} 393 394void __free_pages_ok(struct page *page, unsigned int order) 395{ 396 LIST_HEAD(list); 397 int i; 398 399 arch_free_page(page, order); 400 401 mod_page_state(pgfree, 1 << order); 402 403#ifndef CONFIG_MMU 404 if (order > 0) 405 for (i = 1 ; i < (1 << order) ; ++i) 406 __put_page(page + i); 407#endif 408 409 for (i = 0 ; i < (1 << order) ; ++i) 410 free_pages_check(__FUNCTION__, page + i); 411 list_add(&page->lru, &list); 412 kernel_map_pages(page, 1<<order, 0); 413 free_pages_bulk(page_zone(page), 1, &list, order); 414} 415 416 417/* 418 * The order of subdivision here is critical for the IO subsystem. 419 * Please do not alter this order without good reasons and regression 420 * testing. Specifically, as large blocks of memory are subdivided, 421 * the order in which smaller blocks are delivered depends on the order 422 * they're subdivided in this function. This is the primary factor 423 * influencing the order in which pages are delivered to the IO 424 * subsystem according to empirical testing, and this is also justified 425 * by considering the behavior of a buddy system containing a single 426 * large block of memory acted on by a series of small allocations. 427 * This behavior is a critical factor in sglist merging's success. 428 * 429 * -- wli 430 */ 431static inline struct page * 432expand(struct zone *zone, struct page *page, 433 int low, int high, struct free_area *area) 434{ 435 unsigned long size = 1 << high; 436 437 while (high > low) { 438 area--; 439 high--; 440 size >>= 1; 441 BUG_ON(bad_range(zone, &page[size])); 442 list_add(&page[size].lru, &area->free_list); 443 area->nr_free++; 444 set_page_order(&page[size], high); 445 } 446 return page; 447} 448 449void set_page_refs(struct page *page, int order) 450{ 451#ifdef CONFIG_MMU 452 set_page_count(page, 1); 453#else 454 int i; 455 456 /* 457 * We need to reference all the pages for this order, otherwise if 458 * anyone accesses one of the pages with (get/put) it will be freed. 459 * - eg: access_process_vm() 460 */ 461 for (i = 0; i < (1 << order); i++) 462 set_page_count(page + i, 1); 463#endif /* CONFIG_MMU */ 464} 465 466/* 467 * This page is about to be returned from the page allocator 468 */ 469static void prep_new_page(struct page *page, int order) 470{ 471 if ( page_mapcount(page) || 472 page->mapping != NULL || 473 page_count(page) != 0 || 474 (page->flags & ( 475 1 << PG_lru | 476 1 << PG_private | 477 1 << PG_locked | 478 1 << PG_active | 479 1 << PG_dirty | 480 1 << PG_reclaim | 481 1 << PG_slab | 482 1 << PG_swapcache | 483 1 << PG_writeback | 484 1 << PG_reserved ))) 485 bad_page(__FUNCTION__, page); 486 487 page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 488 1 << PG_referenced | 1 << PG_arch_1 | 489 1 << PG_checked | 1 << PG_mappedtodisk); 490 set_page_private(page, 0); 491 set_page_refs(page, order); 492 kernel_map_pages(page, 1 << order, 1); 493} 494 495/* 496 * Do the hard work of removing an element from the buddy allocator. 497 * Call me with the zone->lock already held. 498 */ 499static struct page *__rmqueue(struct zone *zone, unsigned int order) 500{ 501 struct free_area * area; 502 unsigned int current_order; 503 struct page *page; 504 505 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 506 area = zone->free_area + current_order; 507 if (list_empty(&area->free_list)) 508 continue; 509 510 page = list_entry(area->free_list.next, struct page, lru); 511 list_del(&page->lru); 512 rmv_page_order(page); 513 area->nr_free--; 514 zone->free_pages -= 1UL << order; 515 return expand(zone, page, order, current_order, area); 516 } 517 518 return NULL; 519} 520 521/* 522 * Obtain a specified number of elements from the buddy allocator, all under 523 * a single hold of the lock, for efficiency. Add them to the supplied list. 524 * Returns the number of new pages which were placed at *list. 525 */ 526static int rmqueue_bulk(struct zone *zone, unsigned int order, 527 unsigned long count, struct list_head *list) 528{ 529 unsigned long flags; 530 int i; 531 int allocated = 0; 532 struct page *page; 533 534 spin_lock_irqsave(&zone->lock, flags); 535 for (i = 0; i < count; ++i) { 536 page = __rmqueue(zone, order); 537 if (page == NULL) 538 break; 539 allocated++; 540 list_add_tail(&page->lru, list); 541 } 542 spin_unlock_irqrestore(&zone->lock, flags); 543 return allocated; 544} 545 546#ifdef CONFIG_NUMA 547/* Called from the slab reaper to drain remote pagesets */ 548void drain_remote_pages(void) 549{ 550 struct zone *zone; 551 int i; 552 unsigned long flags; 553 554 local_irq_save(flags); 555 for_each_zone(zone) { 556 struct per_cpu_pageset *pset; 557 558 /* Do not drain local pagesets */ 559 if (zone->zone_pgdat->node_id == numa_node_id()) 560 continue; 561 562 pset = zone->pageset[smp_processor_id()]; 563 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) { 564 struct per_cpu_pages *pcp; 565 566 pcp = &pset->pcp[i]; 567 if (pcp->count) 568 pcp->count -= free_pages_bulk(zone, pcp->count, 569 &pcp->list, 0); 570 } 571 } 572 local_irq_restore(flags); 573} 574#endif 575 576#if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU) 577static void __drain_pages(unsigned int cpu) 578{ 579 struct zone *zone; 580 int i; 581 582 for_each_zone(zone) { 583 struct per_cpu_pageset *pset; 584 585 pset = zone_pcp(zone, cpu); 586 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) { 587 struct per_cpu_pages *pcp; 588 589 pcp = &pset->pcp[i]; 590 pcp->count -= free_pages_bulk(zone, pcp->count, 591 &pcp->list, 0); 592 } 593 } 594} 595#endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */ 596 597#ifdef CONFIG_PM 598 599void mark_free_pages(struct zone *zone) 600{ 601 unsigned long zone_pfn, flags; 602 int order; 603 struct list_head *curr; 604 605 if (!zone->spanned_pages) 606 return; 607 608 spin_lock_irqsave(&zone->lock, flags); 609 for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) 610 ClearPageNosaveFree(pfn_to_page(zone_pfn + zone->zone_start_pfn)); 611 612 for (order = MAX_ORDER - 1; order >= 0; --order) 613 list_for_each(curr, &zone->free_area[order].free_list) { 614 unsigned long start_pfn, i; 615 616 start_pfn = page_to_pfn(list_entry(curr, struct page, lru)); 617 618 for (i=0; i < (1<<order); i++) 619 SetPageNosaveFree(pfn_to_page(start_pfn+i)); 620 } 621 spin_unlock_irqrestore(&zone->lock, flags); 622} 623 624/* 625 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 626 */ 627void drain_local_pages(void) 628{ 629 unsigned long flags; 630 631 local_irq_save(flags); 632 __drain_pages(smp_processor_id()); 633 local_irq_restore(flags); 634} 635#endif /* CONFIG_PM */ 636 637static void zone_statistics(struct zonelist *zonelist, struct zone *z) 638{ 639#ifdef CONFIG_NUMA 640 unsigned long flags; 641 int cpu; 642 pg_data_t *pg = z->zone_pgdat; 643 pg_data_t *orig = zonelist->zones[0]->zone_pgdat; 644 struct per_cpu_pageset *p; 645 646 local_irq_save(flags); 647 cpu = smp_processor_id(); 648 p = zone_pcp(z,cpu); 649 if (pg == orig) { 650 p->numa_hit++; 651 } else { 652 p->numa_miss++; 653 zone_pcp(zonelist->zones[0], cpu)->numa_foreign++; 654 } 655 if (pg == NODE_DATA(numa_node_id())) 656 p->local_node++; 657 else 658 p->other_node++; 659 local_irq_restore(flags); 660#endif 661} 662 663/* 664 * Free a 0-order page 665 */ 666static void FASTCALL(free_hot_cold_page(struct page *page, int cold)); 667static void fastcall free_hot_cold_page(struct page *page, int cold) 668{ 669 struct zone *zone = page_zone(page); 670 struct per_cpu_pages *pcp; 671 unsigned long flags; 672 673 arch_free_page(page, 0); 674 675 kernel_map_pages(page, 1, 0); 676 inc_page_state(pgfree); 677 if (PageAnon(page)) 678 page->mapping = NULL; 679 free_pages_check(__FUNCTION__, page); 680 pcp = &zone_pcp(zone, get_cpu())->pcp[cold]; 681 local_irq_save(flags); 682 list_add(&page->lru, &pcp->list); 683 pcp->count++; 684 if (pcp->count >= pcp->high) 685 pcp->count -= free_pages_bulk(zone, pcp->batch, &pcp->list, 0); 686 local_irq_restore(flags); 687 put_cpu(); 688} 689 690void fastcall free_hot_page(struct page *page) 691{ 692 free_hot_cold_page(page, 0); 693} 694 695void fastcall free_cold_page(struct page *page) 696{ 697 free_hot_cold_page(page, 1); 698} 699 700static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) 701{ 702 int i; 703 704 BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM); 705 for(i = 0; i < (1 << order); i++) 706 clear_highpage(page + i); 707} 708 709/* 710 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 711 * we cheat by calling it from here, in the order > 0 path. Saves a branch 712 * or two. 713 */ 714static struct page * 715buffered_rmqueue(struct zone *zone, int order, gfp_t gfp_flags) 716{ 717 unsigned long flags; 718 struct page *page = NULL; 719 int cold = !!(gfp_flags & __GFP_COLD); 720 721 if (order == 0) { 722 struct per_cpu_pages *pcp; 723 724 pcp = &zone_pcp(zone, get_cpu())->pcp[cold]; 725 local_irq_save(flags); 726 if (pcp->count <= pcp->low) 727 pcp->count += rmqueue_bulk(zone, 0, 728 pcp->batch, &pcp->list); 729 if (pcp->count) { 730 page = list_entry(pcp->list.next, struct page, lru); 731 list_del(&page->lru); 732 pcp->count--; 733 } 734 local_irq_restore(flags); 735 put_cpu(); 736 } 737 738 if (page == NULL) { 739 spin_lock_irqsave(&zone->lock, flags); 740 page = __rmqueue(zone, order); 741 spin_unlock_irqrestore(&zone->lock, flags); 742 } 743 744 if (page != NULL) { 745 BUG_ON(bad_range(zone, page)); 746 mod_page_state_zone(zone, pgalloc, 1 << order); 747 prep_new_page(page, order); 748 749 if (gfp_flags & __GFP_ZERO) 750 prep_zero_page(page, order, gfp_flags); 751 752 if (order && (gfp_flags & __GFP_COMP)) 753 prep_compound_page(page, order); 754 } 755 return page; 756} 757 758/* 759 * Return 1 if free pages are above 'mark'. This takes into account the order 760 * of the allocation. 761 */ 762int zone_watermark_ok(struct zone *z, int order, unsigned long mark, 763 int classzone_idx, int can_try_harder, gfp_t gfp_high) 764{ 765 /* free_pages my go negative - that's OK */ 766 long min = mark, free_pages = z->free_pages - (1 << order) + 1; 767 int o; 768 769 if (gfp_high) 770 min -= min / 2; 771 if (can_try_harder) 772 min -= min / 4; 773 774 if (free_pages <= min + z->lowmem_reserve[classzone_idx]) 775 return 0; 776 for (o = 0; o < order; o++) { 777 /* At the next order, this order's pages become unavailable */ 778 free_pages -= z->free_area[o].nr_free << o; 779 780 /* Require fewer higher order pages to be free */ 781 min >>= 1; 782 783 if (free_pages <= min) 784 return 0; 785 } 786 return 1; 787} 788 789static inline int 790should_reclaim_zone(struct zone *z, gfp_t gfp_mask) 791{ 792 if (!z->reclaim_pages) 793 return 0; 794 if (gfp_mask & __GFP_NORECLAIM) 795 return 0; 796 return 1; 797} 798 799/* 800 * This is the 'heart' of the zoned buddy allocator. 801 */ 802struct page * fastcall 803__alloc_pages(gfp_t gfp_mask, unsigned int order, 804 struct zonelist *zonelist) 805{ 806 const gfp_t wait = gfp_mask & __GFP_WAIT; 807 struct zone **zones, *z; 808 struct page *page; 809 struct reclaim_state reclaim_state; 810 struct task_struct *p = current; 811 int i; 812 int classzone_idx; 813 int do_retry; 814 int can_try_harder; 815 int did_some_progress; 816 817 might_sleep_if(wait); 818 819 /* 820 * The caller may dip into page reserves a bit more if the caller 821 * cannot run direct reclaim, or is the caller has realtime scheduling 822 * policy 823 */ 824 can_try_harder = (unlikely(rt_task(p)) && !in_interrupt()) || !wait; 825 826 zones = zonelist->zones; /* the list of zones suitable for gfp_mask */ 827 828 if (unlikely(zones[0] == NULL)) { 829 /* Should this ever happen?? */ 830 return NULL; 831 } 832 833 classzone_idx = zone_idx(zones[0]); 834 835restart: 836 /* 837 * Go through the zonelist once, looking for a zone with enough free. 838 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 839 */ 840 for (i = 0; (z = zones[i]) != NULL; i++) { 841 int do_reclaim = should_reclaim_zone(z, gfp_mask); 842 843 if (!cpuset_zone_allowed(z, __GFP_HARDWALL)) 844 continue; 845 846 /* 847 * If the zone is to attempt early page reclaim then this loop 848 * will try to reclaim pages and check the watermark a second 849 * time before giving up and falling back to the next zone. 850 */ 851zone_reclaim_retry: 852 if (!zone_watermark_ok(z, order, z->pages_low, 853 classzone_idx, 0, 0)) { 854 if (!do_reclaim) 855 continue; 856 else { 857 zone_reclaim(z, gfp_mask, order); 858 /* Only try reclaim once */ 859 do_reclaim = 0; 860 goto zone_reclaim_retry; 861 } 862 } 863 864 page = buffered_rmqueue(z, order, gfp_mask); 865 if (page) 866 goto got_pg; 867 } 868 869 for (i = 0; (z = zones[i]) != NULL; i++) 870 wakeup_kswapd(z, order); 871 872 /* 873 * Go through the zonelist again. Let __GFP_HIGH and allocations 874 * coming from realtime tasks to go deeper into reserves 875 * 876 * This is the last chance, in general, before the goto nopage. 877 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. 878 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 879 */ 880 for (i = 0; (z = zones[i]) != NULL; i++) { 881 if (!zone_watermark_ok(z, order, z->pages_min, 882 classzone_idx, can_try_harder, 883 gfp_mask & __GFP_HIGH)) 884 continue; 885 886 if (wait && !cpuset_zone_allowed(z, gfp_mask)) 887 continue; 888 889 page = buffered_rmqueue(z, order, gfp_mask); 890 if (page) 891 goto got_pg; 892 } 893 894 /* This allocation should allow future memory freeing. */ 895 896 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) 897 && !in_interrupt()) { 898 if (!(gfp_mask & __GFP_NOMEMALLOC)) { 899 /* go through the zonelist yet again, ignoring mins */ 900 for (i = 0; (z = zones[i]) != NULL; i++) { 901 if (!cpuset_zone_allowed(z, gfp_mask)) 902 continue; 903 page = buffered_rmqueue(z, order, gfp_mask); 904 if (page) 905 goto got_pg; 906 } 907 } 908 goto nopage; 909 } 910 911 /* Atomic allocations - we can't balance anything */ 912 if (!wait) 913 goto nopage; 914 915rebalance: 916 cond_resched(); 917 918 /* We now go into synchronous reclaim */ 919 p->flags |= PF_MEMALLOC; 920 reclaim_state.reclaimed_slab = 0; 921 p->reclaim_state = &reclaim_state; 922 923 did_some_progress = try_to_free_pages(zones, gfp_mask); 924 925 p->reclaim_state = NULL; 926 p->flags &= ~PF_MEMALLOC; 927 928 cond_resched(); 929 930 if (likely(did_some_progress)) { 931 for (i = 0; (z = zones[i]) != NULL; i++) { 932 if (!zone_watermark_ok(z, order, z->pages_min, 933 classzone_idx, can_try_harder, 934 gfp_mask & __GFP_HIGH)) 935 continue; 936 937 if (!cpuset_zone_allowed(z, gfp_mask)) 938 continue; 939 940 page = buffered_rmqueue(z, order, gfp_mask); 941 if (page) 942 goto got_pg; 943 } 944 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { 945 /* 946 * Go through the zonelist yet one more time, keep 947 * very high watermark here, this is only to catch 948 * a parallel oom killing, we must fail if we're still 949 * under heavy pressure. 950 */ 951 for (i = 0; (z = zones[i]) != NULL; i++) { 952 if (!zone_watermark_ok(z, order, z->pages_high, 953 classzone_idx, 0, 0)) 954 continue; 955 956 if (!cpuset_zone_allowed(z, __GFP_HARDWALL)) 957 continue; 958 959 page = buffered_rmqueue(z, order, gfp_mask); 960 if (page) 961 goto got_pg; 962 } 963 964 out_of_memory(gfp_mask, order); 965 goto restart; 966 } 967 968 /* 969 * Don't let big-order allocations loop unless the caller explicitly 970 * requests that. Wait for some write requests to complete then retry. 971 * 972 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order 973 * <= 3, but that may not be true in other implementations. 974 */ 975 do_retry = 0; 976 if (!(gfp_mask & __GFP_NORETRY)) { 977 if ((order <= 3) || (gfp_mask & __GFP_REPEAT)) 978 do_retry = 1; 979 if (gfp_mask & __GFP_NOFAIL) 980 do_retry = 1; 981 } 982 if (do_retry) { 983 blk_congestion_wait(WRITE, HZ/50); 984 goto rebalance; 985 } 986 987nopage: 988 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { 989 printk(KERN_WARNING "%s: page allocation failure." 990 " order:%d, mode:0x%x\n", 991 p->comm, order, gfp_mask); 992 dump_stack(); 993 show_mem(); 994 } 995 return NULL; 996got_pg: 997 zone_statistics(zonelist, z); 998 return page; 999} 1000 1001EXPORT_SYMBOL(__alloc_pages); 1002 1003/* 1004 * Common helper functions. 1005 */ 1006fastcall unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 1007{ 1008 struct page * page; 1009 page = alloc_pages(gfp_mask, order); 1010 if (!page) 1011 return 0; 1012 return (unsigned long) page_address(page); 1013} 1014 1015EXPORT_SYMBOL(__get_free_pages); 1016 1017fastcall unsigned long get_zeroed_page(gfp_t gfp_mask) 1018{ 1019 struct page * page; 1020 1021 /* 1022 * get_zeroed_page() returns a 32-bit address, which cannot represent 1023 * a highmem page 1024 */ 1025 BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 1026 1027 page = alloc_pages(gfp_mask | __GFP_ZERO, 0); 1028 if (page) 1029 return (unsigned long) page_address(page); 1030 return 0; 1031} 1032 1033EXPORT_SYMBOL(get_zeroed_page); 1034 1035void __pagevec_free(struct pagevec *pvec) 1036{ 1037 int i = pagevec_count(pvec); 1038 1039 while (--i >= 0) 1040 free_hot_cold_page(pvec->pages[i], pvec->cold); 1041} 1042 1043fastcall void __free_pages(struct page *page, unsigned int order) 1044{ 1045 if (put_page_testzero(page)) { 1046 if (order == 0) 1047 free_hot_page(page); 1048 else 1049 __free_pages_ok(page, order); 1050 } 1051} 1052 1053EXPORT_SYMBOL(__free_pages); 1054 1055fastcall void free_pages(unsigned long addr, unsigned int order) 1056{ 1057 if (addr != 0) { 1058 BUG_ON(!virt_addr_valid((void *)addr)); 1059 __free_pages(virt_to_page((void *)addr), order); 1060 } 1061} 1062 1063EXPORT_SYMBOL(free_pages); 1064 1065/* 1066 * Total amount of free (allocatable) RAM: 1067 */ 1068unsigned int nr_free_pages(void) 1069{ 1070 unsigned int sum = 0; 1071 struct zone *zone; 1072 1073 for_each_zone(zone) 1074 sum += zone->free_pages; 1075 1076 return sum; 1077} 1078 1079EXPORT_SYMBOL(nr_free_pages); 1080 1081#ifdef CONFIG_NUMA 1082unsigned int nr_free_pages_pgdat(pg_data_t *pgdat) 1083{ 1084 unsigned int i, sum = 0; 1085 1086 for (i = 0; i < MAX_NR_ZONES; i++) 1087 sum += pgdat->node_zones[i].free_pages; 1088 1089 return sum; 1090} 1091#endif 1092 1093static unsigned int nr_free_zone_pages(int offset) 1094{ 1095 /* Just pick one node, since fallback list is circular */ 1096 pg_data_t *pgdat = NODE_DATA(numa_node_id()); 1097 unsigned int sum = 0; 1098 1099 struct zonelist *zonelist = pgdat->node_zonelists + offset; 1100 struct zone **zonep = zonelist->zones; 1101 struct zone *zone; 1102 1103 for (zone = *zonep++; zone; zone = *zonep++) { 1104 unsigned long size = zone->present_pages; 1105 unsigned long high = zone->pages_high; 1106 if (size > high) 1107 sum += size - high; 1108 } 1109 1110 return sum; 1111} 1112 1113/* 1114 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL 1115 */ 1116unsigned int nr_free_buffer_pages(void) 1117{ 1118 return nr_free_zone_pages(gfp_zone(GFP_USER)); 1119} 1120 1121/* 1122 * Amount of free RAM allocatable within all zones 1123 */ 1124unsigned int nr_free_pagecache_pages(void) 1125{ 1126 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER)); 1127} 1128 1129#ifdef CONFIG_HIGHMEM 1130unsigned int nr_free_highpages (void) 1131{ 1132 pg_data_t *pgdat; 1133 unsigned int pages = 0; 1134 1135 for_each_pgdat(pgdat) 1136 pages += pgdat->node_zones[ZONE_HIGHMEM].free_pages; 1137 1138 return pages; 1139} 1140#endif 1141 1142#ifdef CONFIG_NUMA 1143static void show_node(struct zone *zone) 1144{ 1145 printk("Node %d ", zone->zone_pgdat->node_id); 1146} 1147#else 1148#define show_node(zone) do { } while (0) 1149#endif 1150 1151/* 1152 * Accumulate the page_state information across all CPUs. 1153 * The result is unavoidably approximate - it can change 1154 * during and after execution of this function. 1155 */ 1156static DEFINE_PER_CPU(struct page_state, page_states) = {0}; 1157 1158atomic_t nr_pagecache = ATOMIC_INIT(0); 1159EXPORT_SYMBOL(nr_pagecache); 1160#ifdef CONFIG_SMP 1161DEFINE_PER_CPU(long, nr_pagecache_local) = 0; 1162#endif 1163 1164void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask) 1165{ 1166 int cpu = 0; 1167 1168 memset(ret, 0, sizeof(*ret)); 1169 cpus_and(*cpumask, *cpumask, cpu_online_map); 1170 1171 cpu = first_cpu(*cpumask); 1172 while (cpu < NR_CPUS) { 1173 unsigned long *in, *out, off; 1174 1175 in = (unsigned long *)&per_cpu(page_states, cpu); 1176 1177 cpu = next_cpu(cpu, *cpumask); 1178 1179 if (cpu < NR_CPUS) 1180 prefetch(&per_cpu(page_states, cpu)); 1181 1182 out = (unsigned long *)ret; 1183 for (off = 0; off < nr; off++) 1184 *out++ += *in++; 1185 } 1186} 1187 1188void get_page_state_node(struct page_state *ret, int node) 1189{ 1190 int nr; 1191 cpumask_t mask = node_to_cpumask(node); 1192 1193 nr = offsetof(struct page_state, GET_PAGE_STATE_LAST); 1194 nr /= sizeof(unsigned long); 1195 1196 __get_page_state(ret, nr+1, &mask); 1197} 1198 1199void get_page_state(struct page_state *ret) 1200{ 1201 int nr; 1202 cpumask_t mask = CPU_MASK_ALL; 1203 1204 nr = offsetof(struct page_state, GET_PAGE_STATE_LAST); 1205 nr /= sizeof(unsigned long); 1206 1207 __get_page_state(ret, nr + 1, &mask); 1208} 1209 1210void get_full_page_state(struct page_state *ret) 1211{ 1212 cpumask_t mask = CPU_MASK_ALL; 1213 1214 __get_page_state(ret, sizeof(*ret) / sizeof(unsigned long), &mask); 1215} 1216 1217unsigned long __read_page_state(unsigned long offset) 1218{ 1219 unsigned long ret = 0; 1220 int cpu; 1221 1222 for_each_online_cpu(cpu) { 1223 unsigned long in; 1224 1225 in = (unsigned long)&per_cpu(page_states, cpu) + offset; 1226 ret += *((unsigned long *)in); 1227 } 1228 return ret; 1229} 1230 1231void __mod_page_state(unsigned long offset, unsigned long delta) 1232{ 1233 unsigned long flags; 1234 void* ptr; 1235 1236 local_irq_save(flags); 1237 ptr = &__get_cpu_var(page_states); 1238 *(unsigned long*)(ptr + offset) += delta; 1239 local_irq_restore(flags); 1240} 1241 1242EXPORT_SYMBOL(__mod_page_state); 1243 1244void __get_zone_counts(unsigned long *active, unsigned long *inactive, 1245 unsigned long *free, struct pglist_data *pgdat) 1246{ 1247 struct zone *zones = pgdat->node_zones; 1248 int i; 1249 1250 *active = 0; 1251 *inactive = 0; 1252 *free = 0; 1253 for (i = 0; i < MAX_NR_ZONES; i++) { 1254 *active += zones[i].nr_active; 1255 *inactive += zones[i].nr_inactive; 1256 *free += zones[i].free_pages; 1257 } 1258} 1259 1260void get_zone_counts(unsigned long *active, 1261 unsigned long *inactive, unsigned long *free) 1262{ 1263 struct pglist_data *pgdat; 1264 1265 *active = 0; 1266 *inactive = 0; 1267 *free = 0; 1268 for_each_pgdat(pgdat) { 1269 unsigned long l, m, n; 1270 __get_zone_counts(&l, &m, &n, pgdat); 1271 *active += l; 1272 *inactive += m; 1273 *free += n; 1274 } 1275} 1276 1277void si_meminfo(struct sysinfo *val) 1278{ 1279 val->totalram = totalram_pages; 1280 val->sharedram = 0; 1281 val->freeram = nr_free_pages(); 1282 val->bufferram = nr_blockdev_pages(); 1283#ifdef CONFIG_HIGHMEM 1284 val->totalhigh = totalhigh_pages; 1285 val->freehigh = nr_free_highpages(); 1286#else 1287 val->totalhigh = 0; 1288 val->freehigh = 0; 1289#endif 1290 val->mem_unit = PAGE_SIZE; 1291} 1292 1293EXPORT_SYMBOL(si_meminfo); 1294 1295#ifdef CONFIG_NUMA 1296void si_meminfo_node(struct sysinfo *val, int nid) 1297{ 1298 pg_data_t *pgdat = NODE_DATA(nid); 1299 1300 val->totalram = pgdat->node_present_pages; 1301 val->freeram = nr_free_pages_pgdat(pgdat); 1302 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; 1303 val->freehigh = pgdat->node_zones[ZONE_HIGHMEM].free_pages; 1304 val->mem_unit = PAGE_SIZE; 1305} 1306#endif 1307 1308#define K(x) ((x) << (PAGE_SHIFT-10)) 1309 1310/* 1311 * Show free area list (used inside shift_scroll-lock stuff) 1312 * We also calculate the percentage fragmentation. We do this by counting the 1313 * memory on each free list with the exception of the first item on the list. 1314 */ 1315void show_free_areas(void) 1316{ 1317 struct page_state ps; 1318 int cpu, temperature; 1319 unsigned long active; 1320 unsigned long inactive; 1321 unsigned long free; 1322 struct zone *zone; 1323 1324 for_each_zone(zone) { 1325 show_node(zone); 1326 printk("%s per-cpu:", zone->name); 1327 1328 if (!zone->present_pages) { 1329 printk(" empty\n"); 1330 continue; 1331 } else 1332 printk("\n"); 1333 1334 for (cpu = 0; cpu < NR_CPUS; ++cpu) { 1335 struct per_cpu_pageset *pageset; 1336 1337 if (!cpu_possible(cpu)) 1338 continue; 1339 1340 pageset = zone_pcp(zone, cpu); 1341 1342 for (temperature = 0; temperature < 2; temperature++) 1343 printk("cpu %d %s: low %d, high %d, batch %d used:%d\n", 1344 cpu, 1345 temperature ? "cold" : "hot", 1346 pageset->pcp[temperature].low, 1347 pageset->pcp[temperature].high, 1348 pageset->pcp[temperature].batch, 1349 pageset->pcp[temperature].count); 1350 } 1351 } 1352 1353 get_page_state(&ps); 1354 get_zone_counts(&active, &inactive, &free); 1355 1356 printk("Free pages: %11ukB (%ukB HighMem)\n", 1357 K(nr_free_pages()), 1358 K(nr_free_highpages())); 1359 1360 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu " 1361 "unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n", 1362 active, 1363 inactive, 1364 ps.nr_dirty, 1365 ps.nr_writeback, 1366 ps.nr_unstable, 1367 nr_free_pages(), 1368 ps.nr_slab, 1369 ps.nr_mapped, 1370 ps.nr_page_table_pages); 1371 1372 for_each_zone(zone) { 1373 int i; 1374 1375 show_node(zone); 1376 printk("%s" 1377 " free:%lukB" 1378 " min:%lukB" 1379 " low:%lukB" 1380 " high:%lukB" 1381 " active:%lukB" 1382 " inactive:%lukB" 1383 " present:%lukB" 1384 " pages_scanned:%lu" 1385 " all_unreclaimable? %s" 1386 "\n", 1387 zone->name, 1388 K(zone->free_pages), 1389 K(zone->pages_min), 1390 K(zone->pages_low), 1391 K(zone->pages_high), 1392 K(zone->nr_active), 1393 K(zone->nr_inactive), 1394 K(zone->present_pages), 1395 zone->pages_scanned, 1396 (zone->all_unreclaimable ? "yes" : "no") 1397 ); 1398 printk("lowmem_reserve[]:"); 1399 for (i = 0; i < MAX_NR_ZONES; i++) 1400 printk(" %lu", zone->lowmem_reserve[i]); 1401 printk("\n"); 1402 } 1403 1404 for_each_zone(zone) { 1405 unsigned long nr, flags, order, total = 0; 1406 1407 show_node(zone); 1408 printk("%s: ", zone->name); 1409 if (!zone->present_pages) { 1410 printk("empty\n"); 1411 continue; 1412 } 1413 1414 spin_lock_irqsave(&zone->lock, flags); 1415 for (order = 0; order < MAX_ORDER; order++) { 1416 nr = zone->free_area[order].nr_free; 1417 total += nr << order; 1418 printk("%lu*%lukB ", nr, K(1UL) << order); 1419 } 1420 spin_unlock_irqrestore(&zone->lock, flags); 1421 printk("= %lukB\n", K(total)); 1422 } 1423 1424 show_swap_cache_info(); 1425} 1426 1427/* 1428 * Builds allocation fallback zone lists. 1429 */ 1430static int __init build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, int j, int k) 1431{ 1432 switch (k) { 1433 struct zone *zone; 1434 default: 1435 BUG(); 1436 case ZONE_HIGHMEM: 1437 zone = pgdat->node_zones + ZONE_HIGHMEM; 1438 if (zone->present_pages) { 1439#ifndef CONFIG_HIGHMEM 1440 BUG(); 1441#endif 1442 zonelist->zones[j++] = zone; 1443 } 1444 case ZONE_NORMAL: 1445 zone = pgdat->node_zones + ZONE_NORMAL; 1446 if (zone->present_pages) 1447 zonelist->zones[j++] = zone; 1448 case ZONE_DMA: 1449 zone = pgdat->node_zones + ZONE_DMA; 1450 if (zone->present_pages) 1451 zonelist->zones[j++] = zone; 1452 } 1453 1454 return j; 1455} 1456 1457static inline int highest_zone(int zone_bits) 1458{ 1459 int res = ZONE_NORMAL; 1460 if (zone_bits & (__force int)__GFP_HIGHMEM) 1461 res = ZONE_HIGHMEM; 1462 if (zone_bits & (__force int)__GFP_DMA) 1463 res = ZONE_DMA; 1464 return res; 1465} 1466 1467#ifdef CONFIG_NUMA 1468#define MAX_NODE_LOAD (num_online_nodes()) 1469static int __initdata node_load[MAX_NUMNODES]; 1470/** 1471 * find_next_best_node - find the next node that should appear in a given node's fallback list 1472 * @node: node whose fallback list we're appending 1473 * @used_node_mask: nodemask_t of already used nodes 1474 * 1475 * We use a number of factors to determine which is the next node that should 1476 * appear on a given node's fallback list. The node should not have appeared 1477 * already in @node's fallback list, and it should be the next closest node 1478 * according to the distance array (which contains arbitrary distance values 1479 * from each node to each node in the system), and should also prefer nodes 1480 * with no CPUs, since presumably they'll have very little allocation pressure 1481 * on them otherwise. 1482 * It returns -1 if no node is found. 1483 */ 1484static int __init find_next_best_node(int node, nodemask_t *used_node_mask) 1485{ 1486 int i, n, val; 1487 int min_val = INT_MAX; 1488 int best_node = -1; 1489 1490 for_each_online_node(i) { 1491 cpumask_t tmp; 1492 1493 /* Start from local node */ 1494 n = (node+i) % num_online_nodes(); 1495 1496 /* Don't want a node to appear more than once */ 1497 if (node_isset(n, *used_node_mask)) 1498 continue; 1499 1500 /* Use the local node if we haven't already */ 1501 if (!node_isset(node, *used_node_mask)) { 1502 best_node = node; 1503 break; 1504 } 1505 1506 /* Use the distance array to find the distance */ 1507 val = node_distance(node, n); 1508 1509 /* Give preference to headless and unused nodes */ 1510 tmp = node_to_cpumask(n); 1511 if (!cpus_empty(tmp)) 1512 val += PENALTY_FOR_NODE_WITH_CPUS; 1513 1514 /* Slight preference for less loaded node */ 1515 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 1516 val += node_load[n]; 1517 1518 if (val < min_val) { 1519 min_val = val; 1520 best_node = n; 1521 } 1522 } 1523 1524 if (best_node >= 0) 1525 node_set(best_node, *used_node_mask); 1526 1527 return best_node; 1528} 1529 1530static void __init build_zonelists(pg_data_t *pgdat) 1531{ 1532 int i, j, k, node, local_node; 1533 int prev_node, load; 1534 struct zonelist *zonelist; 1535 nodemask_t used_mask; 1536 1537 /* initialize zonelists */ 1538 for (i = 0; i < GFP_ZONETYPES; i++) { 1539 zonelist = pgdat->node_zonelists + i; 1540 zonelist->zones[0] = NULL; 1541 } 1542 1543 /* NUMA-aware ordering of nodes */ 1544 local_node = pgdat->node_id; 1545 load = num_online_nodes(); 1546 prev_node = local_node; 1547 nodes_clear(used_mask); 1548 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 1549 /* 1550 * We don't want to pressure a particular node. 1551 * So adding penalty to the first node in same 1552 * distance group to make it round-robin. 1553 */ 1554 if (node_distance(local_node, node) != 1555 node_distance(local_node, prev_node)) 1556 node_load[node] += load; 1557 prev_node = node; 1558 load--; 1559 for (i = 0; i < GFP_ZONETYPES; i++) { 1560 zonelist = pgdat->node_zonelists + i; 1561 for (j = 0; zonelist->zones[j] != NULL; j++); 1562 1563 k = highest_zone(i); 1564 1565 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k); 1566 zonelist->zones[j] = NULL; 1567 } 1568 } 1569} 1570 1571#else /* CONFIG_NUMA */ 1572 1573static void __init build_zonelists(pg_data_t *pgdat) 1574{ 1575 int i, j, k, node, local_node; 1576 1577 local_node = pgdat->node_id; 1578 for (i = 0; i < GFP_ZONETYPES; i++) { 1579 struct zonelist *zonelist; 1580 1581 zonelist = pgdat->node_zonelists + i; 1582 1583 j = 0; 1584 k = highest_zone(i); 1585 j = build_zonelists_node(pgdat, zonelist, j, k); 1586 /* 1587 * Now we build the zonelist so that it contains the zones 1588 * of all the other nodes. 1589 * We don't want to pressure a particular node, so when 1590 * building the zones for node N, we make sure that the 1591 * zones coming right after the local ones are those from 1592 * node N+1 (modulo N) 1593 */ 1594 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 1595 if (!node_online(node)) 1596 continue; 1597 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k); 1598 } 1599 for (node = 0; node < local_node; node++) { 1600 if (!node_online(node)) 1601 continue; 1602 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k); 1603 } 1604 1605 zonelist->zones[j] = NULL; 1606 } 1607} 1608 1609#endif /* CONFIG_NUMA */ 1610 1611void __init build_all_zonelists(void) 1612{ 1613 int i; 1614 1615 for_each_online_node(i) 1616 build_zonelists(NODE_DATA(i)); 1617 printk("Built %i zonelists\n", num_online_nodes()); 1618 cpuset_init_current_mems_allowed(); 1619} 1620 1621/* 1622 * Helper functions to size the waitqueue hash table. 1623 * Essentially these want to choose hash table sizes sufficiently 1624 * large so that collisions trying to wait on pages are rare. 1625 * But in fact, the number of active page waitqueues on typical 1626 * systems is ridiculously low, less than 200. So this is even 1627 * conservative, even though it seems large. 1628 * 1629 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 1630 * waitqueues, i.e. the size of the waitq table given the number of pages. 1631 */ 1632#define PAGES_PER_WAITQUEUE 256 1633 1634static inline unsigned long wait_table_size(unsigned long pages) 1635{ 1636 unsigned long size = 1; 1637 1638 pages /= PAGES_PER_WAITQUEUE; 1639 1640 while (size < pages) 1641 size <<= 1; 1642 1643 /* 1644 * Once we have dozens or even hundreds of threads sleeping 1645 * on IO we've got bigger problems than wait queue collision. 1646 * Limit the size of the wait table to a reasonable size. 1647 */ 1648 size = min(size, 4096UL); 1649 1650 return max(size, 4UL); 1651} 1652 1653/* 1654 * This is an integer logarithm so that shifts can be used later 1655 * to extract the more random high bits from the multiplicative 1656 * hash function before the remainder is taken. 1657 */ 1658static inline unsigned long wait_table_bits(unsigned long size) 1659{ 1660 return ffz(~size); 1661} 1662 1663#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) 1664 1665static void __init calculate_zone_totalpages(struct pglist_data *pgdat, 1666 unsigned long *zones_size, unsigned long *zholes_size) 1667{ 1668 unsigned long realtotalpages, totalpages = 0; 1669 int i; 1670 1671 for (i = 0; i < MAX_NR_ZONES; i++) 1672 totalpages += zones_size[i]; 1673 pgdat->node_spanned_pages = totalpages; 1674 1675 realtotalpages = totalpages; 1676 if (zholes_size) 1677 for (i = 0; i < MAX_NR_ZONES; i++) 1678 realtotalpages -= zholes_size[i]; 1679 pgdat->node_present_pages = realtotalpages; 1680 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages); 1681} 1682 1683 1684/* 1685 * Initially all pages are reserved - free ones are freed 1686 * up by free_all_bootmem() once the early boot process is 1687 * done. Non-atomic initialization, single-pass. 1688 */ 1689void __devinit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 1690 unsigned long start_pfn) 1691{ 1692 struct page *page; 1693 unsigned long end_pfn = start_pfn + size; 1694 unsigned long pfn; 1695 1696 for (pfn = start_pfn; pfn < end_pfn; pfn++, page++) { 1697 if (!early_pfn_valid(pfn)) 1698 continue; 1699 if (!early_pfn_in_nid(pfn, nid)) 1700 continue; 1701 page = pfn_to_page(pfn); 1702 set_page_links(page, zone, nid, pfn); 1703 set_page_count(page, 1); 1704 reset_page_mapcount(page); 1705 SetPageReserved(page); 1706 INIT_LIST_HEAD(&page->lru); 1707#ifdef WANT_PAGE_VIRTUAL 1708 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 1709 if (!is_highmem_idx(zone)) 1710 set_page_address(page, __va(pfn << PAGE_SHIFT)); 1711#endif 1712 } 1713} 1714 1715void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone, 1716 unsigned long size) 1717{ 1718 int order; 1719 for (order = 0; order < MAX_ORDER ; order++) { 1720 INIT_LIST_HEAD(&zone->free_area[order].free_list); 1721 zone->free_area[order].nr_free = 0; 1722 } 1723} 1724 1725#define ZONETABLE_INDEX(x, zone_nr) ((x << ZONES_SHIFT) | zone_nr) 1726void zonetable_add(struct zone *zone, int nid, int zid, unsigned long pfn, 1727 unsigned long size) 1728{ 1729 unsigned long snum = pfn_to_section_nr(pfn); 1730 unsigned long end = pfn_to_section_nr(pfn + size); 1731 1732 if (FLAGS_HAS_NODE) 1733 zone_table[ZONETABLE_INDEX(nid, zid)] = zone; 1734 else 1735 for (; snum <= end; snum++) 1736 zone_table[ZONETABLE_INDEX(snum, zid)] = zone; 1737} 1738 1739#ifndef __HAVE_ARCH_MEMMAP_INIT 1740#define memmap_init(size, nid, zone, start_pfn) \ 1741 memmap_init_zone((size), (nid), (zone), (start_pfn)) 1742#endif 1743 1744static int __devinit zone_batchsize(struct zone *zone) 1745{ 1746 int batch; 1747 1748 /* 1749 * The per-cpu-pages pools are set to around 1000th of the 1750 * size of the zone. But no more than 1/2 of a meg. 1751 * 1752 * OK, so we don't know how big the cache is. So guess. 1753 */ 1754 batch = zone->present_pages / 1024; 1755 if (batch * PAGE_SIZE > 512 * 1024) 1756 batch = (512 * 1024) / PAGE_SIZE; 1757 batch /= 4; /* We effectively *= 4 below */ 1758 if (batch < 1) 1759 batch = 1; 1760 1761 /* 1762 * We will be trying to allcoate bigger chunks of contiguous 1763 * memory of the order of fls(batch). This should result in 1764 * better cache coloring. 1765 * 1766 * A sanity check also to ensure that batch is still in limits. 1767 */ 1768 batch = (1 << fls(batch + batch/2)); 1769 1770 if (fls(batch) >= (PAGE_SHIFT + MAX_ORDER - 2)) 1771 batch = PAGE_SHIFT + ((MAX_ORDER - 1 - PAGE_SHIFT)/2); 1772 1773 return batch; 1774} 1775 1776inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 1777{ 1778 struct per_cpu_pages *pcp; 1779 1780 memset(p, 0, sizeof(*p)); 1781 1782 pcp = &p->pcp[0]; /* hot */ 1783 pcp->count = 0; 1784 pcp->low = 0; 1785 pcp->high = 6 * batch; 1786 pcp->batch = max(1UL, 1 * batch); 1787 INIT_LIST_HEAD(&pcp->list); 1788 1789 pcp = &p->pcp[1]; /* cold*/ 1790 pcp->count = 0; 1791 pcp->low = 0; 1792 pcp->high = 2 * batch; 1793 pcp->batch = max(1UL, batch/2); 1794 INIT_LIST_HEAD(&pcp->list); 1795} 1796 1797#ifdef CONFIG_NUMA 1798/* 1799 * Boot pageset table. One per cpu which is going to be used for all 1800 * zones and all nodes. The parameters will be set in such a way 1801 * that an item put on a list will immediately be handed over to 1802 * the buddy list. This is safe since pageset manipulation is done 1803 * with interrupts disabled. 1804 * 1805 * Some NUMA counter updates may also be caught by the boot pagesets. 1806 * 1807 * The boot_pagesets must be kept even after bootup is complete for 1808 * unused processors and/or zones. They do play a role for bootstrapping 1809 * hotplugged processors. 1810 * 1811 * zoneinfo_show() and maybe other functions do 1812 * not check if the processor is online before following the pageset pointer. 1813 * Other parts of the kernel may not check if the zone is available. 1814 */ 1815static struct per_cpu_pageset 1816 boot_pageset[NR_CPUS]; 1817 1818/* 1819 * Dynamically allocate memory for the 1820 * per cpu pageset array in struct zone. 1821 */ 1822static int __devinit process_zones(int cpu) 1823{ 1824 struct zone *zone, *dzone; 1825 1826 for_each_zone(zone) { 1827 1828 zone->pageset[cpu] = kmalloc_node(sizeof(struct per_cpu_pageset), 1829 GFP_KERNEL, cpu_to_node(cpu)); 1830 if (!zone->pageset[cpu]) 1831 goto bad; 1832 1833 setup_pageset(zone->pageset[cpu], zone_batchsize(zone)); 1834 } 1835 1836 return 0; 1837bad: 1838 for_each_zone(dzone) { 1839 if (dzone == zone) 1840 break; 1841 kfree(dzone->pageset[cpu]); 1842 dzone->pageset[cpu] = NULL; 1843 } 1844 return -ENOMEM; 1845} 1846 1847static inline void free_zone_pagesets(int cpu) 1848{ 1849#ifdef CONFIG_NUMA 1850 struct zone *zone; 1851 1852 for_each_zone(zone) { 1853 struct per_cpu_pageset *pset = zone_pcp(zone, cpu); 1854 1855 zone_pcp(zone, cpu) = NULL; 1856 kfree(pset); 1857 } 1858#endif 1859} 1860 1861static int __devinit pageset_cpuup_callback(struct notifier_block *nfb, 1862 unsigned long action, 1863 void *hcpu) 1864{ 1865 int cpu = (long)hcpu; 1866 int ret = NOTIFY_OK; 1867 1868 switch (action) { 1869 case CPU_UP_PREPARE: 1870 if (process_zones(cpu)) 1871 ret = NOTIFY_BAD; 1872 break; 1873#ifdef CONFIG_HOTPLUG_CPU 1874 case CPU_DEAD: 1875 free_zone_pagesets(cpu); 1876 break; 1877#endif 1878 default: 1879 break; 1880 } 1881 return ret; 1882} 1883 1884static struct notifier_block pageset_notifier = 1885 { &pageset_cpuup_callback, NULL, 0 }; 1886 1887void __init setup_per_cpu_pageset() 1888{ 1889 int err; 1890 1891 /* Initialize per_cpu_pageset for cpu 0. 1892 * A cpuup callback will do this for every cpu 1893 * as it comes online 1894 */ 1895 err = process_zones(smp_processor_id()); 1896 BUG_ON(err); 1897 register_cpu_notifier(&pageset_notifier); 1898} 1899 1900#endif 1901 1902static __devinit 1903void zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 1904{ 1905 int i; 1906 struct pglist_data *pgdat = zone->zone_pgdat; 1907 1908 /* 1909 * The per-page waitqueue mechanism uses hashed waitqueues 1910 * per zone. 1911 */ 1912 zone->wait_table_size = wait_table_size(zone_size_pages); 1913 zone->wait_table_bits = wait_table_bits(zone->wait_table_size); 1914 zone->wait_table = (wait_queue_head_t *) 1915 alloc_bootmem_node(pgdat, zone->wait_table_size 1916 * sizeof(wait_queue_head_t)); 1917 1918 for(i = 0; i < zone->wait_table_size; ++i) 1919 init_waitqueue_head(zone->wait_table + i); 1920} 1921 1922static __devinit void zone_pcp_init(struct zone *zone) 1923{ 1924 int cpu; 1925 unsigned long batch = zone_batchsize(zone); 1926 1927 for (cpu = 0; cpu < NR_CPUS; cpu++) { 1928#ifdef CONFIG_NUMA 1929 /* Early boot. Slab allocator not functional yet */ 1930 zone->pageset[cpu] = &boot_pageset[cpu]; 1931 setup_pageset(&boot_pageset[cpu],0); 1932#else 1933 setup_pageset(zone_pcp(zone,cpu), batch); 1934#endif 1935 } 1936 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", 1937 zone->name, zone->present_pages, batch); 1938} 1939 1940static __devinit void init_currently_empty_zone(struct zone *zone, 1941 unsigned long zone_start_pfn, unsigned long size) 1942{ 1943 struct pglist_data *pgdat = zone->zone_pgdat; 1944 1945 zone_wait_table_init(zone, size); 1946 pgdat->nr_zones = zone_idx(zone) + 1; 1947 1948 zone->zone_mem_map = pfn_to_page(zone_start_pfn); 1949 zone->zone_start_pfn = zone_start_pfn; 1950 1951 memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn); 1952 1953 zone_init_free_lists(pgdat, zone, zone->spanned_pages); 1954} 1955 1956/* 1957 * Set up the zone data structures: 1958 * - mark all pages reserved 1959 * - mark all memory queues empty 1960 * - clear the memory bitmaps 1961 */ 1962static void __init free_area_init_core(struct pglist_data *pgdat, 1963 unsigned long *zones_size, unsigned long *zholes_size) 1964{ 1965 unsigned long j; 1966 int nid = pgdat->node_id; 1967 unsigned long zone_start_pfn = pgdat->node_start_pfn; 1968 1969 pgdat_resize_init(pgdat); 1970 pgdat->nr_zones = 0; 1971 init_waitqueue_head(&pgdat->kswapd_wait); 1972 pgdat->kswapd_max_order = 0; 1973 1974 for (j = 0; j < MAX_NR_ZONES; j++) { 1975 struct zone *zone = pgdat->node_zones + j; 1976 unsigned long size, realsize; 1977 1978 realsize = size = zones_size[j]; 1979 if (zholes_size) 1980 realsize -= zholes_size[j]; 1981 1982 if (j == ZONE_DMA || j == ZONE_NORMAL) 1983 nr_kernel_pages += realsize; 1984 nr_all_pages += realsize; 1985 1986 zone->spanned_pages = size; 1987 zone->present_pages = realsize; 1988 zone->name = zone_names[j]; 1989 spin_lock_init(&zone->lock); 1990 spin_lock_init(&zone->lru_lock); 1991 zone_seqlock_init(zone); 1992 zone->zone_pgdat = pgdat; 1993 zone->free_pages = 0; 1994 1995 zone->temp_priority = zone->prev_priority = DEF_PRIORITY; 1996 1997 zone_pcp_init(zone); 1998 INIT_LIST_HEAD(&zone->active_list); 1999 INIT_LIST_HEAD(&zone->inactive_list); 2000 zone->nr_scan_active = 0; 2001 zone->nr_scan_inactive = 0; 2002 zone->nr_active = 0; 2003 zone->nr_inactive = 0; 2004 atomic_set(&zone->reclaim_in_progress, 0); 2005 if (!size) 2006 continue; 2007 2008 zonetable_add(zone, nid, j, zone_start_pfn, size); 2009 init_currently_empty_zone(zone, zone_start_pfn, size); 2010 zone_start_pfn += size; 2011 } 2012} 2013 2014static void __init alloc_node_mem_map(struct pglist_data *pgdat) 2015{ 2016 /* Skip empty nodes */ 2017 if (!pgdat->node_spanned_pages) 2018 return; 2019 2020#ifdef CONFIG_FLAT_NODE_MEM_MAP 2021 /* ia64 gets its own node_mem_map, before this, without bootmem */ 2022 if (!pgdat->node_mem_map) { 2023 unsigned long size; 2024 struct page *map; 2025 2026 size = (pgdat->node_spanned_pages + 1) * sizeof(struct page); 2027 map = alloc_remap(pgdat->node_id, size); 2028 if (!map) 2029 map = alloc_bootmem_node(pgdat, size); 2030 pgdat->node_mem_map = map; 2031 } 2032#ifdef CONFIG_FLATMEM 2033 /* 2034 * With no DISCONTIG, the global mem_map is just set as node 0's 2035 */ 2036 if (pgdat == NODE_DATA(0)) 2037 mem_map = NODE_DATA(0)->node_mem_map; 2038#endif 2039#endif /* CONFIG_FLAT_NODE_MEM_MAP */ 2040} 2041 2042void __init free_area_init_node(int nid, struct pglist_data *pgdat, 2043 unsigned long *zones_size, unsigned long node_start_pfn, 2044 unsigned long *zholes_size) 2045{ 2046 pgdat->node_id = nid; 2047 pgdat->node_start_pfn = node_start_pfn; 2048 calculate_zone_totalpages(pgdat, zones_size, zholes_size); 2049 2050 alloc_node_mem_map(pgdat); 2051 2052 free_area_init_core(pgdat, zones_size, zholes_size); 2053} 2054 2055#ifndef CONFIG_NEED_MULTIPLE_NODES 2056static bootmem_data_t contig_bootmem_data; 2057struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data }; 2058 2059EXPORT_SYMBOL(contig_page_data); 2060#endif 2061 2062void __init free_area_init(unsigned long *zones_size) 2063{ 2064 free_area_init_node(0, NODE_DATA(0), zones_size, 2065 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 2066} 2067 2068#ifdef CONFIG_PROC_FS 2069 2070#include <linux/seq_file.h> 2071 2072static void *frag_start(struct seq_file *m, loff_t *pos) 2073{ 2074 pg_data_t *pgdat; 2075 loff_t node = *pos; 2076 2077 for (pgdat = pgdat_list; pgdat && node; pgdat = pgdat->pgdat_next) 2078 --node; 2079 2080 return pgdat; 2081} 2082 2083static void *frag_next(struct seq_file *m, void *arg, loff_t *pos) 2084{ 2085 pg_data_t *pgdat = (pg_data_t *)arg; 2086 2087 (*pos)++; 2088 return pgdat->pgdat_next; 2089} 2090 2091static void frag_stop(struct seq_file *m, void *arg) 2092{ 2093} 2094 2095/* 2096 * This walks the free areas for each zone. 2097 */ 2098static int frag_show(struct seq_file *m, void *arg) 2099{ 2100 pg_data_t *pgdat = (pg_data_t *)arg; 2101 struct zone *zone; 2102 struct zone *node_zones = pgdat->node_zones; 2103 unsigned long flags; 2104 int order; 2105 2106 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { 2107 if (!zone->present_pages) 2108 continue; 2109 2110 spin_lock_irqsave(&zone->lock, flags); 2111 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); 2112 for (order = 0; order < MAX_ORDER; ++order) 2113 seq_printf(m, "%6lu ", zone->free_area[order].nr_free); 2114 spin_unlock_irqrestore(&zone->lock, flags); 2115 seq_putc(m, '\n'); 2116 } 2117 return 0; 2118} 2119 2120struct seq_operations fragmentation_op = { 2121 .start = frag_start, 2122 .next = frag_next, 2123 .stop = frag_stop, 2124 .show = frag_show, 2125}; 2126 2127/* 2128 * Output information about zones in @pgdat. 2129 */ 2130static int zoneinfo_show(struct seq_file *m, void *arg) 2131{ 2132 pg_data_t *pgdat = arg; 2133 struct zone *zone; 2134 struct zone *node_zones = pgdat->node_zones; 2135 unsigned long flags; 2136 2137 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; zone++) { 2138 int i; 2139 2140 if (!zone->present_pages) 2141 continue; 2142 2143 spin_lock_irqsave(&zone->lock, flags); 2144 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name); 2145 seq_printf(m, 2146 "\n pages free %lu" 2147 "\n min %lu" 2148 "\n low %lu" 2149 "\n high %lu" 2150 "\n active %lu" 2151 "\n inactive %lu" 2152 "\n scanned %lu (a: %lu i: %lu)" 2153 "\n spanned %lu" 2154 "\n present %lu", 2155 zone->free_pages, 2156 zone->pages_min, 2157 zone->pages_low, 2158 zone->pages_high, 2159 zone->nr_active, 2160 zone->nr_inactive, 2161 zone->pages_scanned, 2162 zone->nr_scan_active, zone->nr_scan_inactive, 2163 zone->spanned_pages, 2164 zone->present_pages); 2165 seq_printf(m, 2166 "\n protection: (%lu", 2167 zone->lowmem_reserve[0]); 2168 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++) 2169 seq_printf(m, ", %lu", zone->lowmem_reserve[i]); 2170 seq_printf(m, 2171 ")" 2172 "\n pagesets"); 2173 for (i = 0; i < ARRAY_SIZE(zone->pageset); i++) { 2174 struct per_cpu_pageset *pageset; 2175 int j; 2176 2177 pageset = zone_pcp(zone, i); 2178 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) { 2179 if (pageset->pcp[j].count) 2180 break; 2181 } 2182 if (j == ARRAY_SIZE(pageset->pcp)) 2183 continue; 2184 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) { 2185 seq_printf(m, 2186 "\n cpu: %i pcp: %i" 2187 "\n count: %i" 2188 "\n low: %i" 2189 "\n high: %i" 2190 "\n batch: %i", 2191 i, j, 2192 pageset->pcp[j].count, 2193 pageset->pcp[j].low, 2194 pageset->pcp[j].high, 2195 pageset->pcp[j].batch); 2196 } 2197#ifdef CONFIG_NUMA 2198 seq_printf(m, 2199 "\n numa_hit: %lu" 2200 "\n numa_miss: %lu" 2201 "\n numa_foreign: %lu" 2202 "\n interleave_hit: %lu" 2203 "\n local_node: %lu" 2204 "\n other_node: %lu", 2205 pageset->numa_hit, 2206 pageset->numa_miss, 2207 pageset->numa_foreign, 2208 pageset->interleave_hit, 2209 pageset->local_node, 2210 pageset->other_node); 2211#endif 2212 } 2213 seq_printf(m, 2214 "\n all_unreclaimable: %u" 2215 "\n prev_priority: %i" 2216 "\n temp_priority: %i" 2217 "\n start_pfn: %lu", 2218 zone->all_unreclaimable, 2219 zone->prev_priority, 2220 zone->temp_priority, 2221 zone->zone_start_pfn); 2222 spin_unlock_irqrestore(&zone->lock, flags); 2223 seq_putc(m, '\n'); 2224 } 2225 return 0; 2226} 2227 2228struct seq_operations zoneinfo_op = { 2229 .start = frag_start, /* iterate over all zones. The same as in 2230 * fragmentation. */ 2231 .next = frag_next, 2232 .stop = frag_stop, 2233 .show = zoneinfo_show, 2234}; 2235 2236static char *vmstat_text[] = { 2237 "nr_dirty", 2238 "nr_writeback", 2239 "nr_unstable", 2240 "nr_page_table_pages", 2241 "nr_mapped", 2242 "nr_slab", 2243 2244 "pgpgin", 2245 "pgpgout", 2246 "pswpin", 2247 "pswpout", 2248 "pgalloc_high", 2249 2250 "pgalloc_normal", 2251 "pgalloc_dma", 2252 "pgfree", 2253 "pgactivate", 2254 "pgdeactivate", 2255 2256 "pgfault", 2257 "pgmajfault", 2258 "pgrefill_high", 2259 "pgrefill_normal", 2260 "pgrefill_dma", 2261 2262 "pgsteal_high", 2263 "pgsteal_normal", 2264 "pgsteal_dma", 2265 "pgscan_kswapd_high", 2266 "pgscan_kswapd_normal", 2267 2268 "pgscan_kswapd_dma", 2269 "pgscan_direct_high", 2270 "pgscan_direct_normal", 2271 "pgscan_direct_dma", 2272 "pginodesteal", 2273 2274 "slabs_scanned", 2275 "kswapd_steal", 2276 "kswapd_inodesteal", 2277 "pageoutrun", 2278 "allocstall", 2279 2280 "pgrotated", 2281 "nr_bounce", 2282}; 2283 2284static void *vmstat_start(struct seq_file *m, loff_t *pos) 2285{ 2286 struct page_state *ps; 2287 2288 if (*pos >= ARRAY_SIZE(vmstat_text)) 2289 return NULL; 2290 2291 ps = kmalloc(sizeof(*ps), GFP_KERNEL); 2292 m->private = ps; 2293 if (!ps) 2294 return ERR_PTR(-ENOMEM); 2295 get_full_page_state(ps); 2296 ps->pgpgin /= 2; /* sectors -> kbytes */ 2297 ps->pgpgout /= 2; 2298 return (unsigned long *)ps + *pos; 2299} 2300 2301static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos) 2302{ 2303 (*pos)++; 2304 if (*pos >= ARRAY_SIZE(vmstat_text)) 2305 return NULL; 2306 return (unsigned long *)m->private + *pos; 2307} 2308 2309static int vmstat_show(struct seq_file *m, void *arg) 2310{ 2311 unsigned long *l = arg; 2312 unsigned long off = l - (unsigned long *)m->private; 2313 2314 seq_printf(m, "%s %lu\n", vmstat_text[off], *l); 2315 return 0; 2316} 2317 2318static void vmstat_stop(struct seq_file *m, void *arg) 2319{ 2320 kfree(m->private); 2321 m->private = NULL; 2322} 2323 2324struct seq_operations vmstat_op = { 2325 .start = vmstat_start, 2326 .next = vmstat_next, 2327 .stop = vmstat_stop, 2328 .show = vmstat_show, 2329}; 2330 2331#endif /* CONFIG_PROC_FS */ 2332 2333#ifdef CONFIG_HOTPLUG_CPU 2334static int page_alloc_cpu_notify(struct notifier_block *self, 2335 unsigned long action, void *hcpu) 2336{ 2337 int cpu = (unsigned long)hcpu; 2338 long *count; 2339 unsigned long *src, *dest; 2340 2341 if (action == CPU_DEAD) { 2342 int i; 2343 2344 /* Drain local pagecache count. */ 2345 count = &per_cpu(nr_pagecache_local, cpu); 2346 atomic_add(*count, &nr_pagecache); 2347 *count = 0; 2348 local_irq_disable(); 2349 __drain_pages(cpu); 2350 2351 /* Add dead cpu's page_states to our own. */ 2352 dest = (unsigned long *)&__get_cpu_var(page_states); 2353 src = (unsigned long *)&per_cpu(page_states, cpu); 2354 2355 for (i = 0; i < sizeof(struct page_state)/sizeof(unsigned long); 2356 i++) { 2357 dest[i] += src[i]; 2358 src[i] = 0; 2359 } 2360 2361 local_irq_enable(); 2362 } 2363 return NOTIFY_OK; 2364} 2365#endif /* CONFIG_HOTPLUG_CPU */ 2366 2367void __init page_alloc_init(void) 2368{ 2369 hotcpu_notifier(page_alloc_cpu_notify, 0); 2370} 2371 2372/* 2373 * setup_per_zone_lowmem_reserve - called whenever 2374 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 2375 * has a correct pages reserved value, so an adequate number of 2376 * pages are left in the zone after a successful __alloc_pages(). 2377 */ 2378static void setup_per_zone_lowmem_reserve(void) 2379{ 2380 struct pglist_data *pgdat; 2381 int j, idx; 2382 2383 for_each_pgdat(pgdat) { 2384 for (j = 0; j < MAX_NR_ZONES; j++) { 2385 struct zone *zone = pgdat->node_zones + j; 2386 unsigned long present_pages = zone->present_pages; 2387 2388 zone->lowmem_reserve[j] = 0; 2389 2390 for (idx = j-1; idx >= 0; idx--) { 2391 struct zone *lower_zone; 2392 2393 if (sysctl_lowmem_reserve_ratio[idx] < 1) 2394 sysctl_lowmem_reserve_ratio[idx] = 1; 2395 2396 lower_zone = pgdat->node_zones + idx; 2397 lower_zone->lowmem_reserve[j] = present_pages / 2398 sysctl_lowmem_reserve_ratio[idx]; 2399 present_pages += lower_zone->present_pages; 2400 } 2401 } 2402 } 2403} 2404 2405/* 2406 * setup_per_zone_pages_min - called when min_free_kbytes changes. Ensures 2407 * that the pages_{min,low,high} values for each zone are set correctly 2408 * with respect to min_free_kbytes. 2409 */ 2410void setup_per_zone_pages_min(void) 2411{ 2412 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 2413 unsigned long lowmem_pages = 0; 2414 struct zone *zone; 2415 unsigned long flags; 2416 2417 /* Calculate total number of !ZONE_HIGHMEM pages */ 2418 for_each_zone(zone) { 2419 if (!is_highmem(zone)) 2420 lowmem_pages += zone->present_pages; 2421 } 2422 2423 for_each_zone(zone) { 2424 spin_lock_irqsave(&zone->lru_lock, flags); 2425 if (is_highmem(zone)) { 2426 /* 2427 * Often, highmem doesn't need to reserve any pages. 2428 * But the pages_min/low/high values are also used for 2429 * batching up page reclaim activity so we need a 2430 * decent value here. 2431 */ 2432 int min_pages; 2433 2434 min_pages = zone->present_pages / 1024; 2435 if (min_pages < SWAP_CLUSTER_MAX) 2436 min_pages = SWAP_CLUSTER_MAX; 2437 if (min_pages > 128) 2438 min_pages = 128; 2439 zone->pages_min = min_pages; 2440 } else { 2441 /* if it's a lowmem zone, reserve a number of pages 2442 * proportionate to the zone's size. 2443 */ 2444 zone->pages_min = (pages_min * zone->present_pages) / 2445 lowmem_pages; 2446 } 2447 2448 /* 2449 * When interpreting these watermarks, just keep in mind that: 2450 * zone->pages_min == (zone->pages_min * 4) / 4; 2451 */ 2452 zone->pages_low = (zone->pages_min * 5) / 4; 2453 zone->pages_high = (zone->pages_min * 6) / 4; 2454 spin_unlock_irqrestore(&zone->lru_lock, flags); 2455 } 2456} 2457 2458/* 2459 * Initialise min_free_kbytes. 2460 * 2461 * For small machines we want it small (128k min). For large machines 2462 * we want it large (64MB max). But it is not linear, because network 2463 * bandwidth does not increase linearly with machine size. We use 2464 * 2465 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 2466 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 2467 * 2468 * which yields 2469 * 2470 * 16MB: 512k 2471 * 32MB: 724k 2472 * 64MB: 1024k 2473 * 128MB: 1448k 2474 * 256MB: 2048k 2475 * 512MB: 2896k 2476 * 1024MB: 4096k 2477 * 2048MB: 5792k 2478 * 4096MB: 8192k 2479 * 8192MB: 11584k 2480 * 16384MB: 16384k 2481 */ 2482static int __init init_per_zone_pages_min(void) 2483{ 2484 unsigned long lowmem_kbytes; 2485 2486 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 2487 2488 min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 2489 if (min_free_kbytes < 128) 2490 min_free_kbytes = 128; 2491 if (min_free_kbytes > 65536) 2492 min_free_kbytes = 65536; 2493 setup_per_zone_pages_min(); 2494 setup_per_zone_lowmem_reserve(); 2495 return 0; 2496} 2497module_init(init_per_zone_pages_min) 2498 2499/* 2500 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 2501 * that we can call two helper functions whenever min_free_kbytes 2502 * changes. 2503 */ 2504int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 2505 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 2506{ 2507 proc_dointvec(table, write, file, buffer, length, ppos); 2508 setup_per_zone_pages_min(); 2509 return 0; 2510} 2511 2512/* 2513 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 2514 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 2515 * whenever sysctl_lowmem_reserve_ratio changes. 2516 * 2517 * The reserve ratio obviously has absolutely no relation with the 2518 * pages_min watermarks. The lowmem reserve ratio can only make sense 2519 * if in function of the boot time zone sizes. 2520 */ 2521int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, 2522 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 2523{ 2524 proc_dointvec_minmax(table, write, file, buffer, length, ppos); 2525 setup_per_zone_lowmem_reserve(); 2526 return 0; 2527} 2528 2529__initdata int hashdist = HASHDIST_DEFAULT; 2530 2531#ifdef CONFIG_NUMA 2532static int __init set_hashdist(char *str) 2533{ 2534 if (!str) 2535 return 0; 2536 hashdist = simple_strtoul(str, &str, 0); 2537 return 1; 2538} 2539__setup("hashdist=", set_hashdist); 2540#endif 2541 2542/* 2543 * allocate a large system hash table from bootmem 2544 * - it is assumed that the hash table must contain an exact power-of-2 2545 * quantity of entries 2546 * - limit is the number of hash buckets, not the total allocation size 2547 */ 2548void *__init alloc_large_system_hash(const char *tablename, 2549 unsigned long bucketsize, 2550 unsigned long numentries, 2551 int scale, 2552 int flags, 2553 unsigned int *_hash_shift, 2554 unsigned int *_hash_mask, 2555 unsigned long limit) 2556{ 2557 unsigned long long max = limit; 2558 unsigned long log2qty, size; 2559 void *table = NULL; 2560 2561 /* allow the kernel cmdline to have a say */ 2562 if (!numentries) { 2563 /* round applicable memory size up to nearest megabyte */ 2564 numentries = (flags & HASH_HIGHMEM) ? nr_all_pages : nr_kernel_pages; 2565 numentries += (1UL << (20 - PAGE_SHIFT)) - 1; 2566 numentries >>= 20 - PAGE_SHIFT; 2567 numentries <<= 20 - PAGE_SHIFT; 2568 2569 /* limit to 1 bucket per 2^scale bytes of low memory */ 2570 if (scale > PAGE_SHIFT) 2571 numentries >>= (scale - PAGE_SHIFT); 2572 else 2573 numentries <<= (PAGE_SHIFT - scale); 2574 } 2575 /* rounded up to nearest power of 2 in size */ 2576 numentries = 1UL << (long_log2(numentries) + 1); 2577 2578 /* limit allocation size to 1/16 total memory by default */ 2579 if (max == 0) { 2580 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 2581 do_div(max, bucketsize); 2582 } 2583 2584 if (numentries > max) 2585 numentries = max; 2586 2587 log2qty = long_log2(numentries); 2588 2589 do { 2590 size = bucketsize << log2qty; 2591 if (flags & HASH_EARLY) 2592 table = alloc_bootmem(size); 2593 else if (hashdist) 2594 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 2595 else { 2596 unsigned long order; 2597 for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++) 2598 ; 2599 table = (void*) __get_free_pages(GFP_ATOMIC, order); 2600 } 2601 } while (!table && size > PAGE_SIZE && --log2qty); 2602 2603 if (!table) 2604 panic("Failed to allocate %s hash table\n", tablename); 2605 2606 printk("%s hash table entries: %d (order: %d, %lu bytes)\n", 2607 tablename, 2608 (1U << log2qty), 2609 long_log2(size) - PAGE_SHIFT, 2610 size); 2611 2612 if (_hash_shift) 2613 *_hash_shift = log2qty; 2614 if (_hash_mask) 2615 *_hash_mask = (1 << log2qty) - 1; 2616 2617 return table; 2618} 2619