page_alloc.c revision 938929f14cb595f43cd1a4e63e22d36cab1e4a1f
1/* 2 * linux/mm/page_alloc.c 3 * 4 * Manages the free list, the system allocates free pages here. 5 * Note that kmalloc() lives in slab.c 6 * 7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 8 * Swap reorganised 29.12.95, Stephen Tweedie 9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999 11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999 12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000 13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002 14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton) 15 */ 16 17#include <linux/stddef.h> 18#include <linux/mm.h> 19#include <linux/swap.h> 20#include <linux/interrupt.h> 21#include <linux/pagemap.h> 22#include <linux/jiffies.h> 23#include <linux/bootmem.h> 24#include <linux/memblock.h> 25#include <linux/compiler.h> 26#include <linux/kernel.h> 27#include <linux/kmemcheck.h> 28#include <linux/module.h> 29#include <linux/suspend.h> 30#include <linux/pagevec.h> 31#include <linux/blkdev.h> 32#include <linux/slab.h> 33#include <linux/ratelimit.h> 34#include <linux/oom.h> 35#include <linux/notifier.h> 36#include <linux/topology.h> 37#include <linux/sysctl.h> 38#include <linux/cpu.h> 39#include <linux/cpuset.h> 40#include <linux/memory_hotplug.h> 41#include <linux/nodemask.h> 42#include <linux/vmalloc.h> 43#include <linux/vmstat.h> 44#include <linux/mempolicy.h> 45#include <linux/stop_machine.h> 46#include <linux/sort.h> 47#include <linux/pfn.h> 48#include <linux/backing-dev.h> 49#include <linux/fault-inject.h> 50#include <linux/page-isolation.h> 51#include <linux/page_cgroup.h> 52#include <linux/debugobjects.h> 53#include <linux/kmemleak.h> 54#include <linux/memory.h> 55#include <linux/compaction.h> 56#include <trace/events/kmem.h> 57#include <linux/ftrace_event.h> 58#include <linux/memcontrol.h> 59#include <linux/prefetch.h> 60 61#include <asm/tlbflush.h> 62#include <asm/div64.h> 63#include "internal.h" 64 65#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID 66DEFINE_PER_CPU(int, numa_node); 67EXPORT_PER_CPU_SYMBOL(numa_node); 68#endif 69 70#ifdef CONFIG_HAVE_MEMORYLESS_NODES 71/* 72 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly. 73 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined. 74 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem() 75 * defined in <linux/topology.h>. 76 */ 77DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */ 78EXPORT_PER_CPU_SYMBOL(_numa_mem_); 79#endif 80 81/* 82 * Array of node states. 83 */ 84nodemask_t node_states[NR_NODE_STATES] __read_mostly = { 85 [N_POSSIBLE] = NODE_MASK_ALL, 86 [N_ONLINE] = { { [0] = 1UL } }, 87#ifndef CONFIG_NUMA 88 [N_NORMAL_MEMORY] = { { [0] = 1UL } }, 89#ifdef CONFIG_HIGHMEM 90 [N_HIGH_MEMORY] = { { [0] = 1UL } }, 91#endif 92 [N_CPU] = { { [0] = 1UL } }, 93#endif /* NUMA */ 94}; 95EXPORT_SYMBOL(node_states); 96 97unsigned long totalram_pages __read_mostly; 98unsigned long totalreserve_pages __read_mostly; 99int percpu_pagelist_fraction; 100gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; 101 102#ifdef CONFIG_PM_SLEEP 103/* 104 * The following functions are used by the suspend/hibernate code to temporarily 105 * change gfp_allowed_mask in order to avoid using I/O during memory allocations 106 * while devices are suspended. To avoid races with the suspend/hibernate code, 107 * they should always be called with pm_mutex held (gfp_allowed_mask also should 108 * only be modified with pm_mutex held, unless the suspend/hibernate code is 109 * guaranteed not to run in parallel with that modification). 110 */ 111 112static gfp_t saved_gfp_mask; 113 114void pm_restore_gfp_mask(void) 115{ 116 WARN_ON(!mutex_is_locked(&pm_mutex)); 117 if (saved_gfp_mask) { 118 gfp_allowed_mask = saved_gfp_mask; 119 saved_gfp_mask = 0; 120 } 121} 122 123void pm_restrict_gfp_mask(void) 124{ 125 WARN_ON(!mutex_is_locked(&pm_mutex)); 126 WARN_ON(saved_gfp_mask); 127 saved_gfp_mask = gfp_allowed_mask; 128 gfp_allowed_mask &= ~GFP_IOFS; 129} 130#endif /* CONFIG_PM_SLEEP */ 131 132#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 133int pageblock_order __read_mostly; 134#endif 135 136static void __free_pages_ok(struct page *page, unsigned int order); 137 138/* 139 * results with 256, 32 in the lowmem_reserve sysctl: 140 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) 141 * 1G machine -> (16M dma, 784M normal, 224M high) 142 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA 143 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL 144 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA 145 * 146 * TBD: should special case ZONE_DMA32 machines here - in those we normally 147 * don't need any ZONE_NORMAL reservation 148 */ 149int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 150#ifdef CONFIG_ZONE_DMA 151 256, 152#endif 153#ifdef CONFIG_ZONE_DMA32 154 256, 155#endif 156#ifdef CONFIG_HIGHMEM 157 32, 158#endif 159 32, 160}; 161 162EXPORT_SYMBOL(totalram_pages); 163 164static char * const zone_names[MAX_NR_ZONES] = { 165#ifdef CONFIG_ZONE_DMA 166 "DMA", 167#endif 168#ifdef CONFIG_ZONE_DMA32 169 "DMA32", 170#endif 171 "Normal", 172#ifdef CONFIG_HIGHMEM 173 "HighMem", 174#endif 175 "Movable", 176}; 177 178int min_free_kbytes = 1024; 179 180static unsigned long __meminitdata nr_kernel_pages; 181static unsigned long __meminitdata nr_all_pages; 182static unsigned long __meminitdata dma_reserve; 183 184#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 185static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; 186static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; 187static unsigned long __initdata required_kernelcore; 188static unsigned long __initdata required_movablecore; 189static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES]; 190 191/* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ 192int movable_zone; 193EXPORT_SYMBOL(movable_zone); 194#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 195 196#if MAX_NUMNODES > 1 197int nr_node_ids __read_mostly = MAX_NUMNODES; 198int nr_online_nodes __read_mostly = 1; 199EXPORT_SYMBOL(nr_node_ids); 200EXPORT_SYMBOL(nr_online_nodes); 201#endif 202 203int page_group_by_mobility_disabled __read_mostly; 204 205static void set_pageblock_migratetype(struct page *page, int migratetype) 206{ 207 208 if (unlikely(page_group_by_mobility_disabled)) 209 migratetype = MIGRATE_UNMOVABLE; 210 211 set_pageblock_flags_group(page, (unsigned long)migratetype, 212 PB_migrate, PB_migrate_end); 213} 214 215bool oom_killer_disabled __read_mostly; 216 217#ifdef CONFIG_DEBUG_VM 218static int page_outside_zone_boundaries(struct zone *zone, struct page *page) 219{ 220 int ret = 0; 221 unsigned seq; 222 unsigned long pfn = page_to_pfn(page); 223 224 do { 225 seq = zone_span_seqbegin(zone); 226 if (pfn >= zone->zone_start_pfn + zone->spanned_pages) 227 ret = 1; 228 else if (pfn < zone->zone_start_pfn) 229 ret = 1; 230 } while (zone_span_seqretry(zone, seq)); 231 232 return ret; 233} 234 235static int page_is_consistent(struct zone *zone, struct page *page) 236{ 237 if (!pfn_valid_within(page_to_pfn(page))) 238 return 0; 239 if (zone != page_zone(page)) 240 return 0; 241 242 return 1; 243} 244/* 245 * Temporary debugging check for pages not lying within a given zone. 246 */ 247static int bad_range(struct zone *zone, struct page *page) 248{ 249 if (page_outside_zone_boundaries(zone, page)) 250 return 1; 251 if (!page_is_consistent(zone, page)) 252 return 1; 253 254 return 0; 255} 256#else 257static inline int bad_range(struct zone *zone, struct page *page) 258{ 259 return 0; 260} 261#endif 262 263static void bad_page(struct page *page) 264{ 265 static unsigned long resume; 266 static unsigned long nr_shown; 267 static unsigned long nr_unshown; 268 269 /* Don't complain about poisoned pages */ 270 if (PageHWPoison(page)) { 271 reset_page_mapcount(page); /* remove PageBuddy */ 272 return; 273 } 274 275 /* 276 * Allow a burst of 60 reports, then keep quiet for that minute; 277 * or allow a steady drip of one report per second. 278 */ 279 if (nr_shown == 60) { 280 if (time_before(jiffies, resume)) { 281 nr_unshown++; 282 goto out; 283 } 284 if (nr_unshown) { 285 printk(KERN_ALERT 286 "BUG: Bad page state: %lu messages suppressed\n", 287 nr_unshown); 288 nr_unshown = 0; 289 } 290 nr_shown = 0; 291 } 292 if (nr_shown++ == 0) 293 resume = jiffies + 60 * HZ; 294 295 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n", 296 current->comm, page_to_pfn(page)); 297 dump_page(page); 298 299 print_modules(); 300 dump_stack(); 301out: 302 /* Leave bad fields for debug, except PageBuddy could make trouble */ 303 reset_page_mapcount(page); /* remove PageBuddy */ 304 add_taint(TAINT_BAD_PAGE); 305} 306 307/* 308 * Higher-order pages are called "compound pages". They are structured thusly: 309 * 310 * The first PAGE_SIZE page is called the "head page". 311 * 312 * The remaining PAGE_SIZE pages are called "tail pages". 313 * 314 * All pages have PG_compound set. All tail pages have their ->first_page 315 * pointing at the head page. 316 * 317 * The first tail page's ->lru.next holds the address of the compound page's 318 * put_page() function. Its ->lru.prev holds the order of allocation. 319 * This usage means that zero-order pages may not be compound. 320 */ 321 322static void free_compound_page(struct page *page) 323{ 324 __free_pages_ok(page, compound_order(page)); 325} 326 327void prep_compound_page(struct page *page, unsigned long order) 328{ 329 int i; 330 int nr_pages = 1 << order; 331 332 set_compound_page_dtor(page, free_compound_page); 333 set_compound_order(page, order); 334 __SetPageHead(page); 335 for (i = 1; i < nr_pages; i++) { 336 struct page *p = page + i; 337 __SetPageTail(p); 338 set_page_count(p, 0); 339 p->first_page = page; 340 } 341} 342 343/* update __split_huge_page_refcount if you change this function */ 344static int destroy_compound_page(struct page *page, unsigned long order) 345{ 346 int i; 347 int nr_pages = 1 << order; 348 int bad = 0; 349 350 if (unlikely(compound_order(page) != order) || 351 unlikely(!PageHead(page))) { 352 bad_page(page); 353 bad++; 354 } 355 356 __ClearPageHead(page); 357 358 for (i = 1; i < nr_pages; i++) { 359 struct page *p = page + i; 360 361 if (unlikely(!PageTail(p) || (p->first_page != page))) { 362 bad_page(page); 363 bad++; 364 } 365 __ClearPageTail(p); 366 } 367 368 return bad; 369} 370 371static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) 372{ 373 int i; 374 375 /* 376 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO 377 * and __GFP_HIGHMEM from hard or soft interrupt context. 378 */ 379 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); 380 for (i = 0; i < (1 << order); i++) 381 clear_highpage(page + i); 382} 383 384static inline void set_page_order(struct page *page, int order) 385{ 386 set_page_private(page, order); 387 __SetPageBuddy(page); 388} 389 390static inline void rmv_page_order(struct page *page) 391{ 392 __ClearPageBuddy(page); 393 set_page_private(page, 0); 394} 395 396/* 397 * Locate the struct page for both the matching buddy in our 398 * pair (buddy1) and the combined O(n+1) page they form (page). 399 * 400 * 1) Any buddy B1 will have an order O twin B2 which satisfies 401 * the following equation: 402 * B2 = B1 ^ (1 << O) 403 * For example, if the starting buddy (buddy2) is #8 its order 404 * 1 buddy is #10: 405 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 406 * 407 * 2) Any buddy B will have an order O+1 parent P which 408 * satisfies the following equation: 409 * P = B & ~(1 << O) 410 * 411 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 412 */ 413static inline unsigned long 414__find_buddy_index(unsigned long page_idx, unsigned int order) 415{ 416 return page_idx ^ (1 << order); 417} 418 419/* 420 * This function checks whether a page is free && is the buddy 421 * we can do coalesce a page and its buddy if 422 * (a) the buddy is not in a hole && 423 * (b) the buddy is in the buddy system && 424 * (c) a page and its buddy have the same order && 425 * (d) a page and its buddy are in the same zone. 426 * 427 * For recording whether a page is in the buddy system, we set ->_mapcount -2. 428 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock. 429 * 430 * For recording page's order, we use page_private(page). 431 */ 432static inline int page_is_buddy(struct page *page, struct page *buddy, 433 int order) 434{ 435 if (!pfn_valid_within(page_to_pfn(buddy))) 436 return 0; 437 438 if (page_zone_id(page) != page_zone_id(buddy)) 439 return 0; 440 441 if (PageBuddy(buddy) && page_order(buddy) == order) { 442 VM_BUG_ON(page_count(buddy) != 0); 443 return 1; 444 } 445 return 0; 446} 447 448/* 449 * Freeing function for a buddy system allocator. 450 * 451 * The concept of a buddy system is to maintain direct-mapped table 452 * (containing bit values) for memory blocks of various "orders". 453 * The bottom level table contains the map for the smallest allocatable 454 * units of memory (here, pages), and each level above it describes 455 * pairs of units from the levels below, hence, "buddies". 456 * At a high level, all that happens here is marking the table entry 457 * at the bottom level available, and propagating the changes upward 458 * as necessary, plus some accounting needed to play nicely with other 459 * parts of the VM system. 460 * At each level, we keep a list of pages, which are heads of continuous 461 * free pages of length of (1 << order) and marked with _mapcount -2. Page's 462 * order is recorded in page_private(page) field. 463 * So when we are allocating or freeing one, we can derive the state of the 464 * other. That is, if we allocate a small block, and both were 465 * free, the remainder of the region must be split into blocks. 466 * If a block is freed, and its buddy is also free, then this 467 * triggers coalescing into a block of larger size. 468 * 469 * -- wli 470 */ 471 472static inline void __free_one_page(struct page *page, 473 struct zone *zone, unsigned int order, 474 int migratetype) 475{ 476 unsigned long page_idx; 477 unsigned long combined_idx; 478 unsigned long uninitialized_var(buddy_idx); 479 struct page *buddy; 480 481 if (unlikely(PageCompound(page))) 482 if (unlikely(destroy_compound_page(page, order))) 483 return; 484 485 VM_BUG_ON(migratetype == -1); 486 487 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); 488 489 VM_BUG_ON(page_idx & ((1 << order) - 1)); 490 VM_BUG_ON(bad_range(zone, page)); 491 492 while (order < MAX_ORDER-1) { 493 buddy_idx = __find_buddy_index(page_idx, order); 494 buddy = page + (buddy_idx - page_idx); 495 if (!page_is_buddy(page, buddy, order)) 496 break; 497 498 /* Our buddy is free, merge with it and move up one order. */ 499 list_del(&buddy->lru); 500 zone->free_area[order].nr_free--; 501 rmv_page_order(buddy); 502 combined_idx = buddy_idx & page_idx; 503 page = page + (combined_idx - page_idx); 504 page_idx = combined_idx; 505 order++; 506 } 507 set_page_order(page, order); 508 509 /* 510 * If this is not the largest possible page, check if the buddy 511 * of the next-highest order is free. If it is, it's possible 512 * that pages are being freed that will coalesce soon. In case, 513 * that is happening, add the free page to the tail of the list 514 * so it's less likely to be used soon and more likely to be merged 515 * as a higher order page 516 */ 517 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) { 518 struct page *higher_page, *higher_buddy; 519 combined_idx = buddy_idx & page_idx; 520 higher_page = page + (combined_idx - page_idx); 521 buddy_idx = __find_buddy_index(combined_idx, order + 1); 522 higher_buddy = page + (buddy_idx - combined_idx); 523 if (page_is_buddy(higher_page, higher_buddy, order + 1)) { 524 list_add_tail(&page->lru, 525 &zone->free_area[order].free_list[migratetype]); 526 goto out; 527 } 528 } 529 530 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]); 531out: 532 zone->free_area[order].nr_free++; 533} 534 535/* 536 * free_page_mlock() -- clean up attempts to free and mlocked() page. 537 * Page should not be on lru, so no need to fix that up. 538 * free_pages_check() will verify... 539 */ 540static inline void free_page_mlock(struct page *page) 541{ 542 __dec_zone_page_state(page, NR_MLOCK); 543 __count_vm_event(UNEVICTABLE_MLOCKFREED); 544} 545 546static inline int free_pages_check(struct page *page) 547{ 548 if (unlikely(page_mapcount(page) | 549 (page->mapping != NULL) | 550 (atomic_read(&page->_count) != 0) | 551 (page->flags & PAGE_FLAGS_CHECK_AT_FREE) | 552 (mem_cgroup_bad_page_check(page)))) { 553 bad_page(page); 554 return 1; 555 } 556 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP) 557 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; 558 return 0; 559} 560 561/* 562 * Frees a number of pages from the PCP lists 563 * Assumes all pages on list are in same zone, and of same order. 564 * count is the number of pages to free. 565 * 566 * If the zone was previously in an "all pages pinned" state then look to 567 * see if this freeing clears that state. 568 * 569 * And clear the zone's pages_scanned counter, to hold off the "all pages are 570 * pinned" detection logic. 571 */ 572static void free_pcppages_bulk(struct zone *zone, int count, 573 struct per_cpu_pages *pcp) 574{ 575 int migratetype = 0; 576 int batch_free = 0; 577 int to_free = count; 578 579 spin_lock(&zone->lock); 580 zone->all_unreclaimable = 0; 581 zone->pages_scanned = 0; 582 583 while (to_free) { 584 struct page *page; 585 struct list_head *list; 586 587 /* 588 * Remove pages from lists in a round-robin fashion. A 589 * batch_free count is maintained that is incremented when an 590 * empty list is encountered. This is so more pages are freed 591 * off fuller lists instead of spinning excessively around empty 592 * lists 593 */ 594 do { 595 batch_free++; 596 if (++migratetype == MIGRATE_PCPTYPES) 597 migratetype = 0; 598 list = &pcp->lists[migratetype]; 599 } while (list_empty(list)); 600 601 /* This is the only non-empty list. Free them all. */ 602 if (batch_free == MIGRATE_PCPTYPES) 603 batch_free = to_free; 604 605 do { 606 page = list_entry(list->prev, struct page, lru); 607 /* must delete as __free_one_page list manipulates */ 608 list_del(&page->lru); 609 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */ 610 __free_one_page(page, zone, 0, page_private(page)); 611 trace_mm_page_pcpu_drain(page, 0, page_private(page)); 612 } while (--to_free && --batch_free && !list_empty(list)); 613 } 614 __mod_zone_page_state(zone, NR_FREE_PAGES, count); 615 spin_unlock(&zone->lock); 616} 617 618static void free_one_page(struct zone *zone, struct page *page, int order, 619 int migratetype) 620{ 621 spin_lock(&zone->lock); 622 zone->all_unreclaimable = 0; 623 zone->pages_scanned = 0; 624 625 __free_one_page(page, zone, order, migratetype); 626 __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order); 627 spin_unlock(&zone->lock); 628} 629 630static bool free_pages_prepare(struct page *page, unsigned int order) 631{ 632 int i; 633 int bad = 0; 634 635 trace_mm_page_free(page, order); 636 kmemcheck_free_shadow(page, order); 637 638 if (PageAnon(page)) 639 page->mapping = NULL; 640 for (i = 0; i < (1 << order); i++) 641 bad += free_pages_check(page + i); 642 if (bad) 643 return false; 644 645 if (!PageHighMem(page)) { 646 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order); 647 debug_check_no_obj_freed(page_address(page), 648 PAGE_SIZE << order); 649 } 650 arch_free_page(page, order); 651 kernel_map_pages(page, 1 << order, 0); 652 653 return true; 654} 655 656static void __free_pages_ok(struct page *page, unsigned int order) 657{ 658 unsigned long flags; 659 int wasMlocked = __TestClearPageMlocked(page); 660 661 if (!free_pages_prepare(page, order)) 662 return; 663 664 local_irq_save(flags); 665 if (unlikely(wasMlocked)) 666 free_page_mlock(page); 667 __count_vm_events(PGFREE, 1 << order); 668 free_one_page(page_zone(page), page, order, 669 get_pageblock_migratetype(page)); 670 local_irq_restore(flags); 671} 672 673/* 674 * permit the bootmem allocator to evade page validation on high-order frees 675 */ 676void __meminit __free_pages_bootmem(struct page *page, unsigned int order) 677{ 678 if (order == 0) { 679 __ClearPageReserved(page); 680 set_page_count(page, 0); 681 set_page_refcounted(page); 682 __free_page(page); 683 } else { 684 int loop; 685 686 prefetchw(page); 687 for (loop = 0; loop < (1 << order); loop++) { 688 struct page *p = &page[loop]; 689 690 if (loop + 1 < (1 << order)) 691 prefetchw(p + 1); 692 __ClearPageReserved(p); 693 set_page_count(p, 0); 694 } 695 696 set_page_refcounted(page); 697 __free_pages(page, order); 698 } 699} 700 701 702/* 703 * The order of subdivision here is critical for the IO subsystem. 704 * Please do not alter this order without good reasons and regression 705 * testing. Specifically, as large blocks of memory are subdivided, 706 * the order in which smaller blocks are delivered depends on the order 707 * they're subdivided in this function. This is the primary factor 708 * influencing the order in which pages are delivered to the IO 709 * subsystem according to empirical testing, and this is also justified 710 * by considering the behavior of a buddy system containing a single 711 * large block of memory acted on by a series of small allocations. 712 * This behavior is a critical factor in sglist merging's success. 713 * 714 * -- wli 715 */ 716static inline void expand(struct zone *zone, struct page *page, 717 int low, int high, struct free_area *area, 718 int migratetype) 719{ 720 unsigned long size = 1 << high; 721 722 while (high > low) { 723 area--; 724 high--; 725 size >>= 1; 726 VM_BUG_ON(bad_range(zone, &page[size])); 727 list_add(&page[size].lru, &area->free_list[migratetype]); 728 area->nr_free++; 729 set_page_order(&page[size], high); 730 } 731} 732 733/* 734 * This page is about to be returned from the page allocator 735 */ 736static inline int check_new_page(struct page *page) 737{ 738 if (unlikely(page_mapcount(page) | 739 (page->mapping != NULL) | 740 (atomic_read(&page->_count) != 0) | 741 (page->flags & PAGE_FLAGS_CHECK_AT_PREP) | 742 (mem_cgroup_bad_page_check(page)))) { 743 bad_page(page); 744 return 1; 745 } 746 return 0; 747} 748 749static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) 750{ 751 int i; 752 753 for (i = 0; i < (1 << order); i++) { 754 struct page *p = page + i; 755 if (unlikely(check_new_page(p))) 756 return 1; 757 } 758 759 set_page_private(page, 0); 760 set_page_refcounted(page); 761 762 arch_alloc_page(page, order); 763 kernel_map_pages(page, 1 << order, 1); 764 765 if (gfp_flags & __GFP_ZERO) 766 prep_zero_page(page, order, gfp_flags); 767 768 if (order && (gfp_flags & __GFP_COMP)) 769 prep_compound_page(page, order); 770 771 return 0; 772} 773 774/* 775 * Go through the free lists for the given migratetype and remove 776 * the smallest available page from the freelists 777 */ 778static inline 779struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, 780 int migratetype) 781{ 782 unsigned int current_order; 783 struct free_area * area; 784 struct page *page; 785 786 /* Find a page of the appropriate size in the preferred list */ 787 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 788 area = &(zone->free_area[current_order]); 789 if (list_empty(&area->free_list[migratetype])) 790 continue; 791 792 page = list_entry(area->free_list[migratetype].next, 793 struct page, lru); 794 list_del(&page->lru); 795 rmv_page_order(page); 796 area->nr_free--; 797 expand(zone, page, order, current_order, area, migratetype); 798 return page; 799 } 800 801 return NULL; 802} 803 804 805/* 806 * This array describes the order lists are fallen back to when 807 * the free lists for the desirable migrate type are depleted 808 */ 809static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = { 810 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 811 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 812 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, 813 [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */ 814}; 815 816/* 817 * Move the free pages in a range to the free lists of the requested type. 818 * Note that start_page and end_pages are not aligned on a pageblock 819 * boundary. If alignment is required, use move_freepages_block() 820 */ 821static int move_freepages(struct zone *zone, 822 struct page *start_page, struct page *end_page, 823 int migratetype) 824{ 825 struct page *page; 826 unsigned long order; 827 int pages_moved = 0; 828 829#ifndef CONFIG_HOLES_IN_ZONE 830 /* 831 * page_zone is not safe to call in this context when 832 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant 833 * anyway as we check zone boundaries in move_freepages_block(). 834 * Remove at a later date when no bug reports exist related to 835 * grouping pages by mobility 836 */ 837 BUG_ON(page_zone(start_page) != page_zone(end_page)); 838#endif 839 840 for (page = start_page; page <= end_page;) { 841 /* Make sure we are not inadvertently changing nodes */ 842 VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone)); 843 844 if (!pfn_valid_within(page_to_pfn(page))) { 845 page++; 846 continue; 847 } 848 849 if (!PageBuddy(page)) { 850 page++; 851 continue; 852 } 853 854 order = page_order(page); 855 list_move(&page->lru, 856 &zone->free_area[order].free_list[migratetype]); 857 page += 1 << order; 858 pages_moved += 1 << order; 859 } 860 861 return pages_moved; 862} 863 864static int move_freepages_block(struct zone *zone, struct page *page, 865 int migratetype) 866{ 867 unsigned long start_pfn, end_pfn; 868 struct page *start_page, *end_page; 869 870 start_pfn = page_to_pfn(page); 871 start_pfn = start_pfn & ~(pageblock_nr_pages-1); 872 start_page = pfn_to_page(start_pfn); 873 end_page = start_page + pageblock_nr_pages - 1; 874 end_pfn = start_pfn + pageblock_nr_pages - 1; 875 876 /* Do not cross zone boundaries */ 877 if (start_pfn < zone->zone_start_pfn) 878 start_page = page; 879 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages) 880 return 0; 881 882 return move_freepages(zone, start_page, end_page, migratetype); 883} 884 885static void change_pageblock_range(struct page *pageblock_page, 886 int start_order, int migratetype) 887{ 888 int nr_pageblocks = 1 << (start_order - pageblock_order); 889 890 while (nr_pageblocks--) { 891 set_pageblock_migratetype(pageblock_page, migratetype); 892 pageblock_page += pageblock_nr_pages; 893 } 894} 895 896/* Remove an element from the buddy allocator from the fallback list */ 897static inline struct page * 898__rmqueue_fallback(struct zone *zone, int order, int start_migratetype) 899{ 900 struct free_area * area; 901 int current_order; 902 struct page *page; 903 int migratetype, i; 904 905 /* Find the largest possible block of pages in the other list */ 906 for (current_order = MAX_ORDER-1; current_order >= order; 907 --current_order) { 908 for (i = 0; i < MIGRATE_TYPES - 1; i++) { 909 migratetype = fallbacks[start_migratetype][i]; 910 911 /* MIGRATE_RESERVE handled later if necessary */ 912 if (migratetype == MIGRATE_RESERVE) 913 continue; 914 915 area = &(zone->free_area[current_order]); 916 if (list_empty(&area->free_list[migratetype])) 917 continue; 918 919 page = list_entry(area->free_list[migratetype].next, 920 struct page, lru); 921 area->nr_free--; 922 923 /* 924 * If breaking a large block of pages, move all free 925 * pages to the preferred allocation list. If falling 926 * back for a reclaimable kernel allocation, be more 927 * aggressive about taking ownership of free pages 928 */ 929 if (unlikely(current_order >= (pageblock_order >> 1)) || 930 start_migratetype == MIGRATE_RECLAIMABLE || 931 page_group_by_mobility_disabled) { 932 unsigned long pages; 933 pages = move_freepages_block(zone, page, 934 start_migratetype); 935 936 /* Claim the whole block if over half of it is free */ 937 if (pages >= (1 << (pageblock_order-1)) || 938 page_group_by_mobility_disabled) 939 set_pageblock_migratetype(page, 940 start_migratetype); 941 942 migratetype = start_migratetype; 943 } 944 945 /* Remove the page from the freelists */ 946 list_del(&page->lru); 947 rmv_page_order(page); 948 949 /* Take ownership for orders >= pageblock_order */ 950 if (current_order >= pageblock_order) 951 change_pageblock_range(page, current_order, 952 start_migratetype); 953 954 expand(zone, page, order, current_order, area, migratetype); 955 956 trace_mm_page_alloc_extfrag(page, order, current_order, 957 start_migratetype, migratetype); 958 959 return page; 960 } 961 } 962 963 return NULL; 964} 965 966/* 967 * Do the hard work of removing an element from the buddy allocator. 968 * Call me with the zone->lock already held. 969 */ 970static struct page *__rmqueue(struct zone *zone, unsigned int order, 971 int migratetype) 972{ 973 struct page *page; 974 975retry_reserve: 976 page = __rmqueue_smallest(zone, order, migratetype); 977 978 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) { 979 page = __rmqueue_fallback(zone, order, migratetype); 980 981 /* 982 * Use MIGRATE_RESERVE rather than fail an allocation. goto 983 * is used because __rmqueue_smallest is an inline function 984 * and we want just one call site 985 */ 986 if (!page) { 987 migratetype = MIGRATE_RESERVE; 988 goto retry_reserve; 989 } 990 } 991 992 trace_mm_page_alloc_zone_locked(page, order, migratetype); 993 return page; 994} 995 996/* 997 * Obtain a specified number of elements from the buddy allocator, all under 998 * a single hold of the lock, for efficiency. Add them to the supplied list. 999 * Returns the number of new pages which were placed at *list. 1000 */ 1001static int rmqueue_bulk(struct zone *zone, unsigned int order, 1002 unsigned long count, struct list_head *list, 1003 int migratetype, int cold) 1004{ 1005 int i; 1006 1007 spin_lock(&zone->lock); 1008 for (i = 0; i < count; ++i) { 1009 struct page *page = __rmqueue(zone, order, migratetype); 1010 if (unlikely(page == NULL)) 1011 break; 1012 1013 /* 1014 * Split buddy pages returned by expand() are received here 1015 * in physical page order. The page is added to the callers and 1016 * list and the list head then moves forward. From the callers 1017 * perspective, the linked list is ordered by page number in 1018 * some conditions. This is useful for IO devices that can 1019 * merge IO requests if the physical pages are ordered 1020 * properly. 1021 */ 1022 if (likely(cold == 0)) 1023 list_add(&page->lru, list); 1024 else 1025 list_add_tail(&page->lru, list); 1026 set_page_private(page, migratetype); 1027 list = &page->lru; 1028 } 1029 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); 1030 spin_unlock(&zone->lock); 1031 return i; 1032} 1033 1034#ifdef CONFIG_NUMA 1035/* 1036 * Called from the vmstat counter updater to drain pagesets of this 1037 * currently executing processor on remote nodes after they have 1038 * expired. 1039 * 1040 * Note that this function must be called with the thread pinned to 1041 * a single processor. 1042 */ 1043void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) 1044{ 1045 unsigned long flags; 1046 int to_drain; 1047 1048 local_irq_save(flags); 1049 if (pcp->count >= pcp->batch) 1050 to_drain = pcp->batch; 1051 else 1052 to_drain = pcp->count; 1053 free_pcppages_bulk(zone, to_drain, pcp); 1054 pcp->count -= to_drain; 1055 local_irq_restore(flags); 1056} 1057#endif 1058 1059/* 1060 * Drain pages of the indicated processor. 1061 * 1062 * The processor must either be the current processor and the 1063 * thread pinned to the current processor or a processor that 1064 * is not online. 1065 */ 1066static void drain_pages(unsigned int cpu) 1067{ 1068 unsigned long flags; 1069 struct zone *zone; 1070 1071 for_each_populated_zone(zone) { 1072 struct per_cpu_pageset *pset; 1073 struct per_cpu_pages *pcp; 1074 1075 local_irq_save(flags); 1076 pset = per_cpu_ptr(zone->pageset, cpu); 1077 1078 pcp = &pset->pcp; 1079 if (pcp->count) { 1080 free_pcppages_bulk(zone, pcp->count, pcp); 1081 pcp->count = 0; 1082 } 1083 local_irq_restore(flags); 1084 } 1085} 1086 1087/* 1088 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 1089 */ 1090void drain_local_pages(void *arg) 1091{ 1092 drain_pages(smp_processor_id()); 1093} 1094 1095/* 1096 * Spill all the per-cpu pages from all CPUs back into the buddy allocator 1097 */ 1098void drain_all_pages(void) 1099{ 1100 on_each_cpu(drain_local_pages, NULL, 1); 1101} 1102 1103#ifdef CONFIG_HIBERNATION 1104 1105void mark_free_pages(struct zone *zone) 1106{ 1107 unsigned long pfn, max_zone_pfn; 1108 unsigned long flags; 1109 int order, t; 1110 struct list_head *curr; 1111 1112 if (!zone->spanned_pages) 1113 return; 1114 1115 spin_lock_irqsave(&zone->lock, flags); 1116 1117 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; 1118 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 1119 if (pfn_valid(pfn)) { 1120 struct page *page = pfn_to_page(pfn); 1121 1122 if (!swsusp_page_is_forbidden(page)) 1123 swsusp_unset_page_free(page); 1124 } 1125 1126 for_each_migratetype_order(order, t) { 1127 list_for_each(curr, &zone->free_area[order].free_list[t]) { 1128 unsigned long i; 1129 1130 pfn = page_to_pfn(list_entry(curr, struct page, lru)); 1131 for (i = 0; i < (1UL << order); i++) 1132 swsusp_set_page_free(pfn_to_page(pfn + i)); 1133 } 1134 } 1135 spin_unlock_irqrestore(&zone->lock, flags); 1136} 1137#endif /* CONFIG_PM */ 1138 1139/* 1140 * Free a 0-order page 1141 * cold == 1 ? free a cold page : free a hot page 1142 */ 1143void free_hot_cold_page(struct page *page, int cold) 1144{ 1145 struct zone *zone = page_zone(page); 1146 struct per_cpu_pages *pcp; 1147 unsigned long flags; 1148 int migratetype; 1149 int wasMlocked = __TestClearPageMlocked(page); 1150 1151 if (!free_pages_prepare(page, 0)) 1152 return; 1153 1154 migratetype = get_pageblock_migratetype(page); 1155 set_page_private(page, migratetype); 1156 local_irq_save(flags); 1157 if (unlikely(wasMlocked)) 1158 free_page_mlock(page); 1159 __count_vm_event(PGFREE); 1160 1161 /* 1162 * We only track unmovable, reclaimable and movable on pcp lists. 1163 * Free ISOLATE pages back to the allocator because they are being 1164 * offlined but treat RESERVE as movable pages so we can get those 1165 * areas back if necessary. Otherwise, we may have to free 1166 * excessively into the page allocator 1167 */ 1168 if (migratetype >= MIGRATE_PCPTYPES) { 1169 if (unlikely(migratetype == MIGRATE_ISOLATE)) { 1170 free_one_page(zone, page, 0, migratetype); 1171 goto out; 1172 } 1173 migratetype = MIGRATE_MOVABLE; 1174 } 1175 1176 pcp = &this_cpu_ptr(zone->pageset)->pcp; 1177 if (cold) 1178 list_add_tail(&page->lru, &pcp->lists[migratetype]); 1179 else 1180 list_add(&page->lru, &pcp->lists[migratetype]); 1181 pcp->count++; 1182 if (pcp->count >= pcp->high) { 1183 free_pcppages_bulk(zone, pcp->batch, pcp); 1184 pcp->count -= pcp->batch; 1185 } 1186 1187out: 1188 local_irq_restore(flags); 1189} 1190 1191/* 1192 * Free a list of 0-order pages 1193 */ 1194void free_hot_cold_page_list(struct list_head *list, int cold) 1195{ 1196 struct page *page, *next; 1197 1198 list_for_each_entry_safe(page, next, list, lru) { 1199 trace_mm_page_free_batched(page, cold); 1200 free_hot_cold_page(page, cold); 1201 } 1202} 1203 1204/* 1205 * split_page takes a non-compound higher-order page, and splits it into 1206 * n (1<<order) sub-pages: page[0..n] 1207 * Each sub-page must be freed individually. 1208 * 1209 * Note: this is probably too low level an operation for use in drivers. 1210 * Please consult with lkml before using this in your driver. 1211 */ 1212void split_page(struct page *page, unsigned int order) 1213{ 1214 int i; 1215 1216 VM_BUG_ON(PageCompound(page)); 1217 VM_BUG_ON(!page_count(page)); 1218 1219#ifdef CONFIG_KMEMCHECK 1220 /* 1221 * Split shadow pages too, because free(page[0]) would 1222 * otherwise free the whole shadow. 1223 */ 1224 if (kmemcheck_page_is_tracked(page)) 1225 split_page(virt_to_page(page[0].shadow), order); 1226#endif 1227 1228 for (i = 1; i < (1 << order); i++) 1229 set_page_refcounted(page + i); 1230} 1231 1232/* 1233 * Similar to split_page except the page is already free. As this is only 1234 * being used for migration, the migratetype of the block also changes. 1235 * As this is called with interrupts disabled, the caller is responsible 1236 * for calling arch_alloc_page() and kernel_map_page() after interrupts 1237 * are enabled. 1238 * 1239 * Note: this is probably too low level an operation for use in drivers. 1240 * Please consult with lkml before using this in your driver. 1241 */ 1242int split_free_page(struct page *page) 1243{ 1244 unsigned int order; 1245 unsigned long watermark; 1246 struct zone *zone; 1247 1248 BUG_ON(!PageBuddy(page)); 1249 1250 zone = page_zone(page); 1251 order = page_order(page); 1252 1253 /* Obey watermarks as if the page was being allocated */ 1254 watermark = low_wmark_pages(zone) + (1 << order); 1255 if (!zone_watermark_ok(zone, 0, watermark, 0, 0)) 1256 return 0; 1257 1258 /* Remove page from free list */ 1259 list_del(&page->lru); 1260 zone->free_area[order].nr_free--; 1261 rmv_page_order(page); 1262 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order)); 1263 1264 /* Split into individual pages */ 1265 set_page_refcounted(page); 1266 split_page(page, order); 1267 1268 if (order >= pageblock_order - 1) { 1269 struct page *endpage = page + (1 << order) - 1; 1270 for (; page < endpage; page += pageblock_nr_pages) 1271 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 1272 } 1273 1274 return 1 << order; 1275} 1276 1277/* 1278 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 1279 * we cheat by calling it from here, in the order > 0 path. Saves a branch 1280 * or two. 1281 */ 1282static inline 1283struct page *buffered_rmqueue(struct zone *preferred_zone, 1284 struct zone *zone, int order, gfp_t gfp_flags, 1285 int migratetype) 1286{ 1287 unsigned long flags; 1288 struct page *page; 1289 int cold = !!(gfp_flags & __GFP_COLD); 1290 1291again: 1292 if (likely(order == 0)) { 1293 struct per_cpu_pages *pcp; 1294 struct list_head *list; 1295 1296 local_irq_save(flags); 1297 pcp = &this_cpu_ptr(zone->pageset)->pcp; 1298 list = &pcp->lists[migratetype]; 1299 if (list_empty(list)) { 1300 pcp->count += rmqueue_bulk(zone, 0, 1301 pcp->batch, list, 1302 migratetype, cold); 1303 if (unlikely(list_empty(list))) 1304 goto failed; 1305 } 1306 1307 if (cold) 1308 page = list_entry(list->prev, struct page, lru); 1309 else 1310 page = list_entry(list->next, struct page, lru); 1311 1312 list_del(&page->lru); 1313 pcp->count--; 1314 } else { 1315 if (unlikely(gfp_flags & __GFP_NOFAIL)) { 1316 /* 1317 * __GFP_NOFAIL is not to be used in new code. 1318 * 1319 * All __GFP_NOFAIL callers should be fixed so that they 1320 * properly detect and handle allocation failures. 1321 * 1322 * We most definitely don't want callers attempting to 1323 * allocate greater than order-1 page units with 1324 * __GFP_NOFAIL. 1325 */ 1326 WARN_ON_ONCE(order > 1); 1327 } 1328 spin_lock_irqsave(&zone->lock, flags); 1329 page = __rmqueue(zone, order, migratetype); 1330 spin_unlock(&zone->lock); 1331 if (!page) 1332 goto failed; 1333 __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order)); 1334 } 1335 1336 __count_zone_vm_events(PGALLOC, zone, 1 << order); 1337 zone_statistics(preferred_zone, zone, gfp_flags); 1338 local_irq_restore(flags); 1339 1340 VM_BUG_ON(bad_range(zone, page)); 1341 if (prep_new_page(page, order, gfp_flags)) 1342 goto again; 1343 return page; 1344 1345failed: 1346 local_irq_restore(flags); 1347 return NULL; 1348} 1349 1350/* The ALLOC_WMARK bits are used as an index to zone->watermark */ 1351#define ALLOC_WMARK_MIN WMARK_MIN 1352#define ALLOC_WMARK_LOW WMARK_LOW 1353#define ALLOC_WMARK_HIGH WMARK_HIGH 1354#define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */ 1355 1356/* Mask to get the watermark bits */ 1357#define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1) 1358 1359#define ALLOC_HARDER 0x10 /* try to alloc harder */ 1360#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 1361#define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 1362 1363#ifdef CONFIG_FAIL_PAGE_ALLOC 1364 1365static struct { 1366 struct fault_attr attr; 1367 1368 u32 ignore_gfp_highmem; 1369 u32 ignore_gfp_wait; 1370 u32 min_order; 1371} fail_page_alloc = { 1372 .attr = FAULT_ATTR_INITIALIZER, 1373 .ignore_gfp_wait = 1, 1374 .ignore_gfp_highmem = 1, 1375 .min_order = 1, 1376}; 1377 1378static int __init setup_fail_page_alloc(char *str) 1379{ 1380 return setup_fault_attr(&fail_page_alloc.attr, str); 1381} 1382__setup("fail_page_alloc=", setup_fail_page_alloc); 1383 1384static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1385{ 1386 if (order < fail_page_alloc.min_order) 1387 return 0; 1388 if (gfp_mask & __GFP_NOFAIL) 1389 return 0; 1390 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 1391 return 0; 1392 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) 1393 return 0; 1394 1395 return should_fail(&fail_page_alloc.attr, 1 << order); 1396} 1397 1398#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1399 1400static int __init fail_page_alloc_debugfs(void) 1401{ 1402 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR; 1403 struct dentry *dir; 1404 1405 dir = fault_create_debugfs_attr("fail_page_alloc", NULL, 1406 &fail_page_alloc.attr); 1407 if (IS_ERR(dir)) 1408 return PTR_ERR(dir); 1409 1410 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir, 1411 &fail_page_alloc.ignore_gfp_wait)) 1412 goto fail; 1413 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir, 1414 &fail_page_alloc.ignore_gfp_highmem)) 1415 goto fail; 1416 if (!debugfs_create_u32("min-order", mode, dir, 1417 &fail_page_alloc.min_order)) 1418 goto fail; 1419 1420 return 0; 1421fail: 1422 debugfs_remove_recursive(dir); 1423 1424 return -ENOMEM; 1425} 1426 1427late_initcall(fail_page_alloc_debugfs); 1428 1429#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1430 1431#else /* CONFIG_FAIL_PAGE_ALLOC */ 1432 1433static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1434{ 1435 return 0; 1436} 1437 1438#endif /* CONFIG_FAIL_PAGE_ALLOC */ 1439 1440/* 1441 * Return true if free pages are above 'mark'. This takes into account the order 1442 * of the allocation. 1443 */ 1444static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark, 1445 int classzone_idx, int alloc_flags, long free_pages) 1446{ 1447 /* free_pages my go negative - that's OK */ 1448 long min = mark; 1449 int o; 1450 1451 free_pages -= (1 << order) + 1; 1452 if (alloc_flags & ALLOC_HIGH) 1453 min -= min / 2; 1454 if (alloc_flags & ALLOC_HARDER) 1455 min -= min / 4; 1456 1457 if (free_pages <= min + z->lowmem_reserve[classzone_idx]) 1458 return false; 1459 for (o = 0; o < order; o++) { 1460 /* At the next order, this order's pages become unavailable */ 1461 free_pages -= z->free_area[o].nr_free << o; 1462 1463 /* Require fewer higher order pages to be free */ 1464 min >>= 1; 1465 1466 if (free_pages <= min) 1467 return false; 1468 } 1469 return true; 1470} 1471 1472bool zone_watermark_ok(struct zone *z, int order, unsigned long mark, 1473 int classzone_idx, int alloc_flags) 1474{ 1475 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, 1476 zone_page_state(z, NR_FREE_PAGES)); 1477} 1478 1479bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark, 1480 int classzone_idx, int alloc_flags) 1481{ 1482 long free_pages = zone_page_state(z, NR_FREE_PAGES); 1483 1484 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark) 1485 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES); 1486 1487 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, 1488 free_pages); 1489} 1490 1491#ifdef CONFIG_NUMA 1492/* 1493 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to 1494 * skip over zones that are not allowed by the cpuset, or that have 1495 * been recently (in last second) found to be nearly full. See further 1496 * comments in mmzone.h. Reduces cache footprint of zonelist scans 1497 * that have to skip over a lot of full or unallowed zones. 1498 * 1499 * If the zonelist cache is present in the passed in zonelist, then 1500 * returns a pointer to the allowed node mask (either the current 1501 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].) 1502 * 1503 * If the zonelist cache is not available for this zonelist, does 1504 * nothing and returns NULL. 1505 * 1506 * If the fullzones BITMAP in the zonelist cache is stale (more than 1507 * a second since last zap'd) then we zap it out (clear its bits.) 1508 * 1509 * We hold off even calling zlc_setup, until after we've checked the 1510 * first zone in the zonelist, on the theory that most allocations will 1511 * be satisfied from that first zone, so best to examine that zone as 1512 * quickly as we can. 1513 */ 1514static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1515{ 1516 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1517 nodemask_t *allowednodes; /* zonelist_cache approximation */ 1518 1519 zlc = zonelist->zlcache_ptr; 1520 if (!zlc) 1521 return NULL; 1522 1523 if (time_after(jiffies, zlc->last_full_zap + HZ)) { 1524 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1525 zlc->last_full_zap = jiffies; 1526 } 1527 1528 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? 1529 &cpuset_current_mems_allowed : 1530 &node_states[N_HIGH_MEMORY]; 1531 return allowednodes; 1532} 1533 1534/* 1535 * Given 'z' scanning a zonelist, run a couple of quick checks to see 1536 * if it is worth looking at further for free memory: 1537 * 1) Check that the zone isn't thought to be full (doesn't have its 1538 * bit set in the zonelist_cache fullzones BITMAP). 1539 * 2) Check that the zones node (obtained from the zonelist_cache 1540 * z_to_n[] mapping) is allowed in the passed in allowednodes mask. 1541 * Return true (non-zero) if zone is worth looking at further, or 1542 * else return false (zero) if it is not. 1543 * 1544 * This check -ignores- the distinction between various watermarks, 1545 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is 1546 * found to be full for any variation of these watermarks, it will 1547 * be considered full for up to one second by all requests, unless 1548 * we are so low on memory on all allowed nodes that we are forced 1549 * into the second scan of the zonelist. 1550 * 1551 * In the second scan we ignore this zonelist cache and exactly 1552 * apply the watermarks to all zones, even it is slower to do so. 1553 * We are low on memory in the second scan, and should leave no stone 1554 * unturned looking for a free page. 1555 */ 1556static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1557 nodemask_t *allowednodes) 1558{ 1559 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1560 int i; /* index of *z in zonelist zones */ 1561 int n; /* node that zone *z is on */ 1562 1563 zlc = zonelist->zlcache_ptr; 1564 if (!zlc) 1565 return 1; 1566 1567 i = z - zonelist->_zonerefs; 1568 n = zlc->z_to_n[i]; 1569 1570 /* This zone is worth trying if it is allowed but not full */ 1571 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); 1572} 1573 1574/* 1575 * Given 'z' scanning a zonelist, set the corresponding bit in 1576 * zlc->fullzones, so that subsequent attempts to allocate a page 1577 * from that zone don't waste time re-examining it. 1578 */ 1579static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1580{ 1581 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1582 int i; /* index of *z in zonelist zones */ 1583 1584 zlc = zonelist->zlcache_ptr; 1585 if (!zlc) 1586 return; 1587 1588 i = z - zonelist->_zonerefs; 1589 1590 set_bit(i, zlc->fullzones); 1591} 1592 1593/* 1594 * clear all zones full, called after direct reclaim makes progress so that 1595 * a zone that was recently full is not skipped over for up to a second 1596 */ 1597static void zlc_clear_zones_full(struct zonelist *zonelist) 1598{ 1599 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1600 1601 zlc = zonelist->zlcache_ptr; 1602 if (!zlc) 1603 return; 1604 1605 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1606} 1607 1608#else /* CONFIG_NUMA */ 1609 1610static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1611{ 1612 return NULL; 1613} 1614 1615static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1616 nodemask_t *allowednodes) 1617{ 1618 return 1; 1619} 1620 1621static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1622{ 1623} 1624 1625static void zlc_clear_zones_full(struct zonelist *zonelist) 1626{ 1627} 1628#endif /* CONFIG_NUMA */ 1629 1630/* 1631 * get_page_from_freelist goes through the zonelist trying to allocate 1632 * a page. 1633 */ 1634static struct page * 1635get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order, 1636 struct zonelist *zonelist, int high_zoneidx, int alloc_flags, 1637 struct zone *preferred_zone, int migratetype) 1638{ 1639 struct zoneref *z; 1640 struct page *page = NULL; 1641 int classzone_idx; 1642 struct zone *zone; 1643 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ 1644 int zlc_active = 0; /* set if using zonelist_cache */ 1645 int did_zlc_setup = 0; /* just call zlc_setup() one time */ 1646 1647 classzone_idx = zone_idx(preferred_zone); 1648zonelist_scan: 1649 /* 1650 * Scan zonelist, looking for a zone with enough free. 1651 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1652 */ 1653 for_each_zone_zonelist_nodemask(zone, z, zonelist, 1654 high_zoneidx, nodemask) { 1655 if (NUMA_BUILD && zlc_active && 1656 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 1657 continue; 1658 if ((alloc_flags & ALLOC_CPUSET) && 1659 !cpuset_zone_allowed_softwall(zone, gfp_mask)) 1660 continue; 1661 1662 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK); 1663 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { 1664 unsigned long mark; 1665 int ret; 1666 1667 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK]; 1668 if (zone_watermark_ok(zone, order, mark, 1669 classzone_idx, alloc_flags)) 1670 goto try_this_zone; 1671 1672 if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) { 1673 /* 1674 * we do zlc_setup if there are multiple nodes 1675 * and before considering the first zone allowed 1676 * by the cpuset. 1677 */ 1678 allowednodes = zlc_setup(zonelist, alloc_flags); 1679 zlc_active = 1; 1680 did_zlc_setup = 1; 1681 } 1682 1683 if (zone_reclaim_mode == 0) 1684 goto this_zone_full; 1685 1686 /* 1687 * As we may have just activated ZLC, check if the first 1688 * eligible zone has failed zone_reclaim recently. 1689 */ 1690 if (NUMA_BUILD && zlc_active && 1691 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 1692 continue; 1693 1694 ret = zone_reclaim(zone, gfp_mask, order); 1695 switch (ret) { 1696 case ZONE_RECLAIM_NOSCAN: 1697 /* did not scan */ 1698 continue; 1699 case ZONE_RECLAIM_FULL: 1700 /* scanned but unreclaimable */ 1701 continue; 1702 default: 1703 /* did we reclaim enough */ 1704 if (!zone_watermark_ok(zone, order, mark, 1705 classzone_idx, alloc_flags)) 1706 goto this_zone_full; 1707 } 1708 } 1709 1710try_this_zone: 1711 page = buffered_rmqueue(preferred_zone, zone, order, 1712 gfp_mask, migratetype); 1713 if (page) 1714 break; 1715this_zone_full: 1716 if (NUMA_BUILD) 1717 zlc_mark_zone_full(zonelist, z); 1718 } 1719 1720 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) { 1721 /* Disable zlc cache for second zonelist scan */ 1722 zlc_active = 0; 1723 goto zonelist_scan; 1724 } 1725 return page; 1726} 1727 1728/* 1729 * Large machines with many possible nodes should not always dump per-node 1730 * meminfo in irq context. 1731 */ 1732static inline bool should_suppress_show_mem(void) 1733{ 1734 bool ret = false; 1735 1736#if NODES_SHIFT > 8 1737 ret = in_interrupt(); 1738#endif 1739 return ret; 1740} 1741 1742static DEFINE_RATELIMIT_STATE(nopage_rs, 1743 DEFAULT_RATELIMIT_INTERVAL, 1744 DEFAULT_RATELIMIT_BURST); 1745 1746void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...) 1747{ 1748 unsigned int filter = SHOW_MEM_FILTER_NODES; 1749 1750 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs)) 1751 return; 1752 1753 /* 1754 * This documents exceptions given to allocations in certain 1755 * contexts that are allowed to allocate outside current's set 1756 * of allowed nodes. 1757 */ 1758 if (!(gfp_mask & __GFP_NOMEMALLOC)) 1759 if (test_thread_flag(TIF_MEMDIE) || 1760 (current->flags & (PF_MEMALLOC | PF_EXITING))) 1761 filter &= ~SHOW_MEM_FILTER_NODES; 1762 if (in_interrupt() || !(gfp_mask & __GFP_WAIT)) 1763 filter &= ~SHOW_MEM_FILTER_NODES; 1764 1765 if (fmt) { 1766 struct va_format vaf; 1767 va_list args; 1768 1769 va_start(args, fmt); 1770 1771 vaf.fmt = fmt; 1772 vaf.va = &args; 1773 1774 pr_warn("%pV", &vaf); 1775 1776 va_end(args); 1777 } 1778 1779 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n", 1780 current->comm, order, gfp_mask); 1781 1782 dump_stack(); 1783 if (!should_suppress_show_mem()) 1784 show_mem(filter); 1785} 1786 1787static inline int 1788should_alloc_retry(gfp_t gfp_mask, unsigned int order, 1789 unsigned long pages_reclaimed) 1790{ 1791 /* Do not loop if specifically requested */ 1792 if (gfp_mask & __GFP_NORETRY) 1793 return 0; 1794 1795 /* 1796 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER 1797 * means __GFP_NOFAIL, but that may not be true in other 1798 * implementations. 1799 */ 1800 if (order <= PAGE_ALLOC_COSTLY_ORDER) 1801 return 1; 1802 1803 /* 1804 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is 1805 * specified, then we retry until we no longer reclaim any pages 1806 * (above), or we've reclaimed an order of pages at least as 1807 * large as the allocation's order. In both cases, if the 1808 * allocation still fails, we stop retrying. 1809 */ 1810 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order)) 1811 return 1; 1812 1813 /* 1814 * Don't let big-order allocations loop unless the caller 1815 * explicitly requests that. 1816 */ 1817 if (gfp_mask & __GFP_NOFAIL) 1818 return 1; 1819 1820 return 0; 1821} 1822 1823static inline struct page * 1824__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, 1825 struct zonelist *zonelist, enum zone_type high_zoneidx, 1826 nodemask_t *nodemask, struct zone *preferred_zone, 1827 int migratetype) 1828{ 1829 struct page *page; 1830 1831 /* Acquire the OOM killer lock for the zones in zonelist */ 1832 if (!try_set_zonelist_oom(zonelist, gfp_mask)) { 1833 schedule_timeout_uninterruptible(1); 1834 return NULL; 1835 } 1836 1837 /* 1838 * Go through the zonelist yet one more time, keep very high watermark 1839 * here, this is only to catch a parallel oom killing, we must fail if 1840 * we're still under heavy pressure. 1841 */ 1842 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, 1843 order, zonelist, high_zoneidx, 1844 ALLOC_WMARK_HIGH|ALLOC_CPUSET, 1845 preferred_zone, migratetype); 1846 if (page) 1847 goto out; 1848 1849 if (!(gfp_mask & __GFP_NOFAIL)) { 1850 /* The OOM killer will not help higher order allocs */ 1851 if (order > PAGE_ALLOC_COSTLY_ORDER) 1852 goto out; 1853 /* The OOM killer does not needlessly kill tasks for lowmem */ 1854 if (high_zoneidx < ZONE_NORMAL) 1855 goto out; 1856 /* 1857 * GFP_THISNODE contains __GFP_NORETRY and we never hit this. 1858 * Sanity check for bare calls of __GFP_THISNODE, not real OOM. 1859 * The caller should handle page allocation failure by itself if 1860 * it specifies __GFP_THISNODE. 1861 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER. 1862 */ 1863 if (gfp_mask & __GFP_THISNODE) 1864 goto out; 1865 } 1866 /* Exhausted what can be done so it's blamo time */ 1867 out_of_memory(zonelist, gfp_mask, order, nodemask); 1868 1869out: 1870 clear_zonelist_oom(zonelist, gfp_mask); 1871 return page; 1872} 1873 1874#ifdef CONFIG_COMPACTION 1875/* Try memory compaction for high-order allocations before reclaim */ 1876static struct page * 1877__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, 1878 struct zonelist *zonelist, enum zone_type high_zoneidx, 1879 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, 1880 int migratetype, unsigned long *did_some_progress, 1881 bool sync_migration) 1882{ 1883 struct page *page; 1884 1885 if (!order || compaction_deferred(preferred_zone)) 1886 return NULL; 1887 1888 current->flags |= PF_MEMALLOC; 1889 *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask, 1890 nodemask, sync_migration); 1891 current->flags &= ~PF_MEMALLOC; 1892 if (*did_some_progress != COMPACT_SKIPPED) { 1893 1894 /* Page migration frees to the PCP lists but we want merging */ 1895 drain_pages(get_cpu()); 1896 put_cpu(); 1897 1898 page = get_page_from_freelist(gfp_mask, nodemask, 1899 order, zonelist, high_zoneidx, 1900 alloc_flags, preferred_zone, 1901 migratetype); 1902 if (page) { 1903 preferred_zone->compact_considered = 0; 1904 preferred_zone->compact_defer_shift = 0; 1905 count_vm_event(COMPACTSUCCESS); 1906 return page; 1907 } 1908 1909 /* 1910 * It's bad if compaction run occurs and fails. 1911 * The most likely reason is that pages exist, 1912 * but not enough to satisfy watermarks. 1913 */ 1914 count_vm_event(COMPACTFAIL); 1915 defer_compaction(preferred_zone); 1916 1917 cond_resched(); 1918 } 1919 1920 return NULL; 1921} 1922#else 1923static inline struct page * 1924__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, 1925 struct zonelist *zonelist, enum zone_type high_zoneidx, 1926 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, 1927 int migratetype, unsigned long *did_some_progress, 1928 bool sync_migration) 1929{ 1930 return NULL; 1931} 1932#endif /* CONFIG_COMPACTION */ 1933 1934/* The really slow allocator path where we enter direct reclaim */ 1935static inline struct page * 1936__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order, 1937 struct zonelist *zonelist, enum zone_type high_zoneidx, 1938 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, 1939 int migratetype, unsigned long *did_some_progress) 1940{ 1941 struct page *page = NULL; 1942 struct reclaim_state reclaim_state; 1943 bool drained = false; 1944 1945 cond_resched(); 1946 1947 /* We now go into synchronous reclaim */ 1948 cpuset_memory_pressure_bump(); 1949 current->flags |= PF_MEMALLOC; 1950 lockdep_set_current_reclaim_state(gfp_mask); 1951 reclaim_state.reclaimed_slab = 0; 1952 current->reclaim_state = &reclaim_state; 1953 1954 *did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask); 1955 1956 current->reclaim_state = NULL; 1957 lockdep_clear_current_reclaim_state(); 1958 current->flags &= ~PF_MEMALLOC; 1959 1960 cond_resched(); 1961 1962 if (unlikely(!(*did_some_progress))) 1963 return NULL; 1964 1965 /* After successful reclaim, reconsider all zones for allocation */ 1966 if (NUMA_BUILD) 1967 zlc_clear_zones_full(zonelist); 1968 1969retry: 1970 page = get_page_from_freelist(gfp_mask, nodemask, order, 1971 zonelist, high_zoneidx, 1972 alloc_flags, preferred_zone, 1973 migratetype); 1974 1975 /* 1976 * If an allocation failed after direct reclaim, it could be because 1977 * pages are pinned on the per-cpu lists. Drain them and try again 1978 */ 1979 if (!page && !drained) { 1980 drain_all_pages(); 1981 drained = true; 1982 goto retry; 1983 } 1984 1985 return page; 1986} 1987 1988/* 1989 * This is called in the allocator slow-path if the allocation request is of 1990 * sufficient urgency to ignore watermarks and take other desperate measures 1991 */ 1992static inline struct page * 1993__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order, 1994 struct zonelist *zonelist, enum zone_type high_zoneidx, 1995 nodemask_t *nodemask, struct zone *preferred_zone, 1996 int migratetype) 1997{ 1998 struct page *page; 1999 2000 do { 2001 page = get_page_from_freelist(gfp_mask, nodemask, order, 2002 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS, 2003 preferred_zone, migratetype); 2004 2005 if (!page && gfp_mask & __GFP_NOFAIL) 2006 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50); 2007 } while (!page && (gfp_mask & __GFP_NOFAIL)); 2008 2009 return page; 2010} 2011 2012static inline 2013void wake_all_kswapd(unsigned int order, struct zonelist *zonelist, 2014 enum zone_type high_zoneidx, 2015 enum zone_type classzone_idx) 2016{ 2017 struct zoneref *z; 2018 struct zone *zone; 2019 2020 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) 2021 wakeup_kswapd(zone, order, classzone_idx); 2022} 2023 2024static inline int 2025gfp_to_alloc_flags(gfp_t gfp_mask) 2026{ 2027 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; 2028 const gfp_t wait = gfp_mask & __GFP_WAIT; 2029 2030 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */ 2031 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH); 2032 2033 /* 2034 * The caller may dip into page reserves a bit more if the caller 2035 * cannot run direct reclaim, or if the caller has realtime scheduling 2036 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will 2037 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). 2038 */ 2039 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH); 2040 2041 if (!wait) { 2042 /* 2043 * Not worth trying to allocate harder for 2044 * __GFP_NOMEMALLOC even if it can't schedule. 2045 */ 2046 if (!(gfp_mask & __GFP_NOMEMALLOC)) 2047 alloc_flags |= ALLOC_HARDER; 2048 /* 2049 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. 2050 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 2051 */ 2052 alloc_flags &= ~ALLOC_CPUSET; 2053 } else if (unlikely(rt_task(current)) && !in_interrupt()) 2054 alloc_flags |= ALLOC_HARDER; 2055 2056 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) { 2057 if (!in_interrupt() && 2058 ((current->flags & PF_MEMALLOC) || 2059 unlikely(test_thread_flag(TIF_MEMDIE)))) 2060 alloc_flags |= ALLOC_NO_WATERMARKS; 2061 } 2062 2063 return alloc_flags; 2064} 2065 2066static inline struct page * 2067__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, 2068 struct zonelist *zonelist, enum zone_type high_zoneidx, 2069 nodemask_t *nodemask, struct zone *preferred_zone, 2070 int migratetype) 2071{ 2072 const gfp_t wait = gfp_mask & __GFP_WAIT; 2073 struct page *page = NULL; 2074 int alloc_flags; 2075 unsigned long pages_reclaimed = 0; 2076 unsigned long did_some_progress; 2077 bool sync_migration = false; 2078 2079 /* 2080 * In the slowpath, we sanity check order to avoid ever trying to 2081 * reclaim >= MAX_ORDER areas which will never succeed. Callers may 2082 * be using allocators in order of preference for an area that is 2083 * too large. 2084 */ 2085 if (order >= MAX_ORDER) { 2086 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN)); 2087 return NULL; 2088 } 2089 2090 /* 2091 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and 2092 * __GFP_NOWARN set) should not cause reclaim since the subsystem 2093 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim 2094 * using a larger set of nodes after it has established that the 2095 * allowed per node queues are empty and that nodes are 2096 * over allocated. 2097 */ 2098 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) 2099 goto nopage; 2100 2101restart: 2102 if (!(gfp_mask & __GFP_NO_KSWAPD)) 2103 wake_all_kswapd(order, zonelist, high_zoneidx, 2104 zone_idx(preferred_zone)); 2105 2106 /* 2107 * OK, we're below the kswapd watermark and have kicked background 2108 * reclaim. Now things get more complex, so set up alloc_flags according 2109 * to how we want to proceed. 2110 */ 2111 alloc_flags = gfp_to_alloc_flags(gfp_mask); 2112 2113 /* 2114 * Find the true preferred zone if the allocation is unconstrained by 2115 * cpusets. 2116 */ 2117 if (!(alloc_flags & ALLOC_CPUSET) && !nodemask) 2118 first_zones_zonelist(zonelist, high_zoneidx, NULL, 2119 &preferred_zone); 2120 2121rebalance: 2122 /* This is the last chance, in general, before the goto nopage. */ 2123 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, 2124 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS, 2125 preferred_zone, migratetype); 2126 if (page) 2127 goto got_pg; 2128 2129 /* Allocate without watermarks if the context allows */ 2130 if (alloc_flags & ALLOC_NO_WATERMARKS) { 2131 page = __alloc_pages_high_priority(gfp_mask, order, 2132 zonelist, high_zoneidx, nodemask, 2133 preferred_zone, migratetype); 2134 if (page) 2135 goto got_pg; 2136 } 2137 2138 /* Atomic allocations - we can't balance anything */ 2139 if (!wait) 2140 goto nopage; 2141 2142 /* Avoid recursion of direct reclaim */ 2143 if (current->flags & PF_MEMALLOC) 2144 goto nopage; 2145 2146 /* Avoid allocations with no watermarks from looping endlessly */ 2147 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL)) 2148 goto nopage; 2149 2150 /* 2151 * Try direct compaction. The first pass is asynchronous. Subsequent 2152 * attempts after direct reclaim are synchronous 2153 */ 2154 page = __alloc_pages_direct_compact(gfp_mask, order, 2155 zonelist, high_zoneidx, 2156 nodemask, 2157 alloc_flags, preferred_zone, 2158 migratetype, &did_some_progress, 2159 sync_migration); 2160 if (page) 2161 goto got_pg; 2162 sync_migration = true; 2163 2164 /* Try direct reclaim and then allocating */ 2165 page = __alloc_pages_direct_reclaim(gfp_mask, order, 2166 zonelist, high_zoneidx, 2167 nodemask, 2168 alloc_flags, preferred_zone, 2169 migratetype, &did_some_progress); 2170 if (page) 2171 goto got_pg; 2172 2173 /* 2174 * If we failed to make any progress reclaiming, then we are 2175 * running out of options and have to consider going OOM 2176 */ 2177 if (!did_some_progress) { 2178 if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { 2179 if (oom_killer_disabled) 2180 goto nopage; 2181 page = __alloc_pages_may_oom(gfp_mask, order, 2182 zonelist, high_zoneidx, 2183 nodemask, preferred_zone, 2184 migratetype); 2185 if (page) 2186 goto got_pg; 2187 2188 if (!(gfp_mask & __GFP_NOFAIL)) { 2189 /* 2190 * The oom killer is not called for high-order 2191 * allocations that may fail, so if no progress 2192 * is being made, there are no other options and 2193 * retrying is unlikely to help. 2194 */ 2195 if (order > PAGE_ALLOC_COSTLY_ORDER) 2196 goto nopage; 2197 /* 2198 * The oom killer is not called for lowmem 2199 * allocations to prevent needlessly killing 2200 * innocent tasks. 2201 */ 2202 if (high_zoneidx < ZONE_NORMAL) 2203 goto nopage; 2204 } 2205 2206 goto restart; 2207 } 2208 } 2209 2210 /* Check if we should retry the allocation */ 2211 pages_reclaimed += did_some_progress; 2212 if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) { 2213 /* Wait for some write requests to complete then retry */ 2214 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50); 2215 goto rebalance; 2216 } else { 2217 /* 2218 * High-order allocations do not necessarily loop after 2219 * direct reclaim and reclaim/compaction depends on compaction 2220 * being called after reclaim so call directly if necessary 2221 */ 2222 page = __alloc_pages_direct_compact(gfp_mask, order, 2223 zonelist, high_zoneidx, 2224 nodemask, 2225 alloc_flags, preferred_zone, 2226 migratetype, &did_some_progress, 2227 sync_migration); 2228 if (page) 2229 goto got_pg; 2230 } 2231 2232nopage: 2233 warn_alloc_failed(gfp_mask, order, NULL); 2234 return page; 2235got_pg: 2236 if (kmemcheck_enabled) 2237 kmemcheck_pagealloc_alloc(page, order, gfp_mask); 2238 return page; 2239 2240} 2241 2242/* 2243 * This is the 'heart' of the zoned buddy allocator. 2244 */ 2245struct page * 2246__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, 2247 struct zonelist *zonelist, nodemask_t *nodemask) 2248{ 2249 enum zone_type high_zoneidx = gfp_zone(gfp_mask); 2250 struct zone *preferred_zone; 2251 struct page *page; 2252 int migratetype = allocflags_to_migratetype(gfp_mask); 2253 2254 gfp_mask &= gfp_allowed_mask; 2255 2256 lockdep_trace_alloc(gfp_mask); 2257 2258 might_sleep_if(gfp_mask & __GFP_WAIT); 2259 2260 if (should_fail_alloc_page(gfp_mask, order)) 2261 return NULL; 2262 2263 /* 2264 * Check the zones suitable for the gfp_mask contain at least one 2265 * valid zone. It's possible to have an empty zonelist as a result 2266 * of GFP_THISNODE and a memoryless node 2267 */ 2268 if (unlikely(!zonelist->_zonerefs->zone)) 2269 return NULL; 2270 2271 get_mems_allowed(); 2272 /* The preferred zone is used for statistics later */ 2273 first_zones_zonelist(zonelist, high_zoneidx, 2274 nodemask ? : &cpuset_current_mems_allowed, 2275 &preferred_zone); 2276 if (!preferred_zone) { 2277 put_mems_allowed(); 2278 return NULL; 2279 } 2280 2281 /* First allocation attempt */ 2282 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order, 2283 zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET, 2284 preferred_zone, migratetype); 2285 if (unlikely(!page)) 2286 page = __alloc_pages_slowpath(gfp_mask, order, 2287 zonelist, high_zoneidx, nodemask, 2288 preferred_zone, migratetype); 2289 put_mems_allowed(); 2290 2291 trace_mm_page_alloc(page, order, gfp_mask, migratetype); 2292 return page; 2293} 2294EXPORT_SYMBOL(__alloc_pages_nodemask); 2295 2296/* 2297 * Common helper functions. 2298 */ 2299unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 2300{ 2301 struct page *page; 2302 2303 /* 2304 * __get_free_pages() returns a 32-bit address, which cannot represent 2305 * a highmem page 2306 */ 2307 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 2308 2309 page = alloc_pages(gfp_mask, order); 2310 if (!page) 2311 return 0; 2312 return (unsigned long) page_address(page); 2313} 2314EXPORT_SYMBOL(__get_free_pages); 2315 2316unsigned long get_zeroed_page(gfp_t gfp_mask) 2317{ 2318 return __get_free_pages(gfp_mask | __GFP_ZERO, 0); 2319} 2320EXPORT_SYMBOL(get_zeroed_page); 2321 2322void __free_pages(struct page *page, unsigned int order) 2323{ 2324 if (put_page_testzero(page)) { 2325 if (order == 0) 2326 free_hot_cold_page(page, 0); 2327 else 2328 __free_pages_ok(page, order); 2329 } 2330} 2331 2332EXPORT_SYMBOL(__free_pages); 2333 2334void free_pages(unsigned long addr, unsigned int order) 2335{ 2336 if (addr != 0) { 2337 VM_BUG_ON(!virt_addr_valid((void *)addr)); 2338 __free_pages(virt_to_page((void *)addr), order); 2339 } 2340} 2341 2342EXPORT_SYMBOL(free_pages); 2343 2344static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size) 2345{ 2346 if (addr) { 2347 unsigned long alloc_end = addr + (PAGE_SIZE << order); 2348 unsigned long used = addr + PAGE_ALIGN(size); 2349 2350 split_page(virt_to_page((void *)addr), order); 2351 while (used < alloc_end) { 2352 free_page(used); 2353 used += PAGE_SIZE; 2354 } 2355 } 2356 return (void *)addr; 2357} 2358 2359/** 2360 * alloc_pages_exact - allocate an exact number physically-contiguous pages. 2361 * @size: the number of bytes to allocate 2362 * @gfp_mask: GFP flags for the allocation 2363 * 2364 * This function is similar to alloc_pages(), except that it allocates the 2365 * minimum number of pages to satisfy the request. alloc_pages() can only 2366 * allocate memory in power-of-two pages. 2367 * 2368 * This function is also limited by MAX_ORDER. 2369 * 2370 * Memory allocated by this function must be released by free_pages_exact(). 2371 */ 2372void *alloc_pages_exact(size_t size, gfp_t gfp_mask) 2373{ 2374 unsigned int order = get_order(size); 2375 unsigned long addr; 2376 2377 addr = __get_free_pages(gfp_mask, order); 2378 return make_alloc_exact(addr, order, size); 2379} 2380EXPORT_SYMBOL(alloc_pages_exact); 2381 2382/** 2383 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous 2384 * pages on a node. 2385 * @nid: the preferred node ID where memory should be allocated 2386 * @size: the number of bytes to allocate 2387 * @gfp_mask: GFP flags for the allocation 2388 * 2389 * Like alloc_pages_exact(), but try to allocate on node nid first before falling 2390 * back. 2391 * Note this is not alloc_pages_exact_node() which allocates on a specific node, 2392 * but is not exact. 2393 */ 2394void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask) 2395{ 2396 unsigned order = get_order(size); 2397 struct page *p = alloc_pages_node(nid, gfp_mask, order); 2398 if (!p) 2399 return NULL; 2400 return make_alloc_exact((unsigned long)page_address(p), order, size); 2401} 2402EXPORT_SYMBOL(alloc_pages_exact_nid); 2403 2404/** 2405 * free_pages_exact - release memory allocated via alloc_pages_exact() 2406 * @virt: the value returned by alloc_pages_exact. 2407 * @size: size of allocation, same value as passed to alloc_pages_exact(). 2408 * 2409 * Release the memory allocated by a previous call to alloc_pages_exact. 2410 */ 2411void free_pages_exact(void *virt, size_t size) 2412{ 2413 unsigned long addr = (unsigned long)virt; 2414 unsigned long end = addr + PAGE_ALIGN(size); 2415 2416 while (addr < end) { 2417 free_page(addr); 2418 addr += PAGE_SIZE; 2419 } 2420} 2421EXPORT_SYMBOL(free_pages_exact); 2422 2423static unsigned int nr_free_zone_pages(int offset) 2424{ 2425 struct zoneref *z; 2426 struct zone *zone; 2427 2428 /* Just pick one node, since fallback list is circular */ 2429 unsigned int sum = 0; 2430 2431 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); 2432 2433 for_each_zone_zonelist(zone, z, zonelist, offset) { 2434 unsigned long size = zone->present_pages; 2435 unsigned long high = high_wmark_pages(zone); 2436 if (size > high) 2437 sum += size - high; 2438 } 2439 2440 return sum; 2441} 2442 2443/* 2444 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL 2445 */ 2446unsigned int nr_free_buffer_pages(void) 2447{ 2448 return nr_free_zone_pages(gfp_zone(GFP_USER)); 2449} 2450EXPORT_SYMBOL_GPL(nr_free_buffer_pages); 2451 2452/* 2453 * Amount of free RAM allocatable within all zones 2454 */ 2455unsigned int nr_free_pagecache_pages(void) 2456{ 2457 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); 2458} 2459 2460static inline void show_node(struct zone *zone) 2461{ 2462 if (NUMA_BUILD) 2463 printk("Node %d ", zone_to_nid(zone)); 2464} 2465 2466void si_meminfo(struct sysinfo *val) 2467{ 2468 val->totalram = totalram_pages; 2469 val->sharedram = 0; 2470 val->freeram = global_page_state(NR_FREE_PAGES); 2471 val->bufferram = nr_blockdev_pages(); 2472 val->totalhigh = totalhigh_pages; 2473 val->freehigh = nr_free_highpages(); 2474 val->mem_unit = PAGE_SIZE; 2475} 2476 2477EXPORT_SYMBOL(si_meminfo); 2478 2479#ifdef CONFIG_NUMA 2480void si_meminfo_node(struct sysinfo *val, int nid) 2481{ 2482 pg_data_t *pgdat = NODE_DATA(nid); 2483 2484 val->totalram = pgdat->node_present_pages; 2485 val->freeram = node_page_state(nid, NR_FREE_PAGES); 2486#ifdef CONFIG_HIGHMEM 2487 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; 2488 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], 2489 NR_FREE_PAGES); 2490#else 2491 val->totalhigh = 0; 2492 val->freehigh = 0; 2493#endif 2494 val->mem_unit = PAGE_SIZE; 2495} 2496#endif 2497 2498/* 2499 * Determine whether the node should be displayed or not, depending on whether 2500 * SHOW_MEM_FILTER_NODES was passed to show_free_areas(). 2501 */ 2502bool skip_free_areas_node(unsigned int flags, int nid) 2503{ 2504 bool ret = false; 2505 2506 if (!(flags & SHOW_MEM_FILTER_NODES)) 2507 goto out; 2508 2509 get_mems_allowed(); 2510 ret = !node_isset(nid, cpuset_current_mems_allowed); 2511 put_mems_allowed(); 2512out: 2513 return ret; 2514} 2515 2516#define K(x) ((x) << (PAGE_SHIFT-10)) 2517 2518/* 2519 * Show free area list (used inside shift_scroll-lock stuff) 2520 * We also calculate the percentage fragmentation. We do this by counting the 2521 * memory on each free list with the exception of the first item on the list. 2522 * Suppresses nodes that are not allowed by current's cpuset if 2523 * SHOW_MEM_FILTER_NODES is passed. 2524 */ 2525void show_free_areas(unsigned int filter) 2526{ 2527 int cpu; 2528 struct zone *zone; 2529 2530 for_each_populated_zone(zone) { 2531 if (skip_free_areas_node(filter, zone_to_nid(zone))) 2532 continue; 2533 show_node(zone); 2534 printk("%s per-cpu:\n", zone->name); 2535 2536 for_each_online_cpu(cpu) { 2537 struct per_cpu_pageset *pageset; 2538 2539 pageset = per_cpu_ptr(zone->pageset, cpu); 2540 2541 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n", 2542 cpu, pageset->pcp.high, 2543 pageset->pcp.batch, pageset->pcp.count); 2544 } 2545 } 2546 2547 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n" 2548 " active_file:%lu inactive_file:%lu isolated_file:%lu\n" 2549 " unevictable:%lu" 2550 " dirty:%lu writeback:%lu unstable:%lu\n" 2551 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n" 2552 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n", 2553 global_page_state(NR_ACTIVE_ANON), 2554 global_page_state(NR_INACTIVE_ANON), 2555 global_page_state(NR_ISOLATED_ANON), 2556 global_page_state(NR_ACTIVE_FILE), 2557 global_page_state(NR_INACTIVE_FILE), 2558 global_page_state(NR_ISOLATED_FILE), 2559 global_page_state(NR_UNEVICTABLE), 2560 global_page_state(NR_FILE_DIRTY), 2561 global_page_state(NR_WRITEBACK), 2562 global_page_state(NR_UNSTABLE_NFS), 2563 global_page_state(NR_FREE_PAGES), 2564 global_page_state(NR_SLAB_RECLAIMABLE), 2565 global_page_state(NR_SLAB_UNRECLAIMABLE), 2566 global_page_state(NR_FILE_MAPPED), 2567 global_page_state(NR_SHMEM), 2568 global_page_state(NR_PAGETABLE), 2569 global_page_state(NR_BOUNCE)); 2570 2571 for_each_populated_zone(zone) { 2572 int i; 2573 2574 if (skip_free_areas_node(filter, zone_to_nid(zone))) 2575 continue; 2576 show_node(zone); 2577 printk("%s" 2578 " free:%lukB" 2579 " min:%lukB" 2580 " low:%lukB" 2581 " high:%lukB" 2582 " active_anon:%lukB" 2583 " inactive_anon:%lukB" 2584 " active_file:%lukB" 2585 " inactive_file:%lukB" 2586 " unevictable:%lukB" 2587 " isolated(anon):%lukB" 2588 " isolated(file):%lukB" 2589 " present:%lukB" 2590 " mlocked:%lukB" 2591 " dirty:%lukB" 2592 " writeback:%lukB" 2593 " mapped:%lukB" 2594 " shmem:%lukB" 2595 " slab_reclaimable:%lukB" 2596 " slab_unreclaimable:%lukB" 2597 " kernel_stack:%lukB" 2598 " pagetables:%lukB" 2599 " unstable:%lukB" 2600 " bounce:%lukB" 2601 " writeback_tmp:%lukB" 2602 " pages_scanned:%lu" 2603 " all_unreclaimable? %s" 2604 "\n", 2605 zone->name, 2606 K(zone_page_state(zone, NR_FREE_PAGES)), 2607 K(min_wmark_pages(zone)), 2608 K(low_wmark_pages(zone)), 2609 K(high_wmark_pages(zone)), 2610 K(zone_page_state(zone, NR_ACTIVE_ANON)), 2611 K(zone_page_state(zone, NR_INACTIVE_ANON)), 2612 K(zone_page_state(zone, NR_ACTIVE_FILE)), 2613 K(zone_page_state(zone, NR_INACTIVE_FILE)), 2614 K(zone_page_state(zone, NR_UNEVICTABLE)), 2615 K(zone_page_state(zone, NR_ISOLATED_ANON)), 2616 K(zone_page_state(zone, NR_ISOLATED_FILE)), 2617 K(zone->present_pages), 2618 K(zone_page_state(zone, NR_MLOCK)), 2619 K(zone_page_state(zone, NR_FILE_DIRTY)), 2620 K(zone_page_state(zone, NR_WRITEBACK)), 2621 K(zone_page_state(zone, NR_FILE_MAPPED)), 2622 K(zone_page_state(zone, NR_SHMEM)), 2623 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)), 2624 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)), 2625 zone_page_state(zone, NR_KERNEL_STACK) * 2626 THREAD_SIZE / 1024, 2627 K(zone_page_state(zone, NR_PAGETABLE)), 2628 K(zone_page_state(zone, NR_UNSTABLE_NFS)), 2629 K(zone_page_state(zone, NR_BOUNCE)), 2630 K(zone_page_state(zone, NR_WRITEBACK_TEMP)), 2631 zone->pages_scanned, 2632 (zone->all_unreclaimable ? "yes" : "no") 2633 ); 2634 printk("lowmem_reserve[]:"); 2635 for (i = 0; i < MAX_NR_ZONES; i++) 2636 printk(" %lu", zone->lowmem_reserve[i]); 2637 printk("\n"); 2638 } 2639 2640 for_each_populated_zone(zone) { 2641 unsigned long nr[MAX_ORDER], flags, order, total = 0; 2642 2643 if (skip_free_areas_node(filter, zone_to_nid(zone))) 2644 continue; 2645 show_node(zone); 2646 printk("%s: ", zone->name); 2647 2648 spin_lock_irqsave(&zone->lock, flags); 2649 for (order = 0; order < MAX_ORDER; order++) { 2650 nr[order] = zone->free_area[order].nr_free; 2651 total += nr[order] << order; 2652 } 2653 spin_unlock_irqrestore(&zone->lock, flags); 2654 for (order = 0; order < MAX_ORDER; order++) 2655 printk("%lu*%lukB ", nr[order], K(1UL) << order); 2656 printk("= %lukB\n", K(total)); 2657 } 2658 2659 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES)); 2660 2661 show_swap_cache_info(); 2662} 2663 2664static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) 2665{ 2666 zoneref->zone = zone; 2667 zoneref->zone_idx = zone_idx(zone); 2668} 2669 2670/* 2671 * Builds allocation fallback zone lists. 2672 * 2673 * Add all populated zones of a node to the zonelist. 2674 */ 2675static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, 2676 int nr_zones, enum zone_type zone_type) 2677{ 2678 struct zone *zone; 2679 2680 BUG_ON(zone_type >= MAX_NR_ZONES); 2681 zone_type++; 2682 2683 do { 2684 zone_type--; 2685 zone = pgdat->node_zones + zone_type; 2686 if (populated_zone(zone)) { 2687 zoneref_set_zone(zone, 2688 &zonelist->_zonerefs[nr_zones++]); 2689 check_highest_zone(zone_type); 2690 } 2691 2692 } while (zone_type); 2693 return nr_zones; 2694} 2695 2696 2697/* 2698 * zonelist_order: 2699 * 0 = automatic detection of better ordering. 2700 * 1 = order by ([node] distance, -zonetype) 2701 * 2 = order by (-zonetype, [node] distance) 2702 * 2703 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create 2704 * the same zonelist. So only NUMA can configure this param. 2705 */ 2706#define ZONELIST_ORDER_DEFAULT 0 2707#define ZONELIST_ORDER_NODE 1 2708#define ZONELIST_ORDER_ZONE 2 2709 2710/* zonelist order in the kernel. 2711 * set_zonelist_order() will set this to NODE or ZONE. 2712 */ 2713static int current_zonelist_order = ZONELIST_ORDER_DEFAULT; 2714static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"}; 2715 2716 2717#ifdef CONFIG_NUMA 2718/* The value user specified ....changed by config */ 2719static int user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2720/* string for sysctl */ 2721#define NUMA_ZONELIST_ORDER_LEN 16 2722char numa_zonelist_order[16] = "default"; 2723 2724/* 2725 * interface for configure zonelist ordering. 2726 * command line option "numa_zonelist_order" 2727 * = "[dD]efault - default, automatic configuration. 2728 * = "[nN]ode - order by node locality, then by zone within node 2729 * = "[zZ]one - order by zone, then by locality within zone 2730 */ 2731 2732static int __parse_numa_zonelist_order(char *s) 2733{ 2734 if (*s == 'd' || *s == 'D') { 2735 user_zonelist_order = ZONELIST_ORDER_DEFAULT; 2736 } else if (*s == 'n' || *s == 'N') { 2737 user_zonelist_order = ZONELIST_ORDER_NODE; 2738 } else if (*s == 'z' || *s == 'Z') { 2739 user_zonelist_order = ZONELIST_ORDER_ZONE; 2740 } else { 2741 printk(KERN_WARNING 2742 "Ignoring invalid numa_zonelist_order value: " 2743 "%s\n", s); 2744 return -EINVAL; 2745 } 2746 return 0; 2747} 2748 2749static __init int setup_numa_zonelist_order(char *s) 2750{ 2751 int ret; 2752 2753 if (!s) 2754 return 0; 2755 2756 ret = __parse_numa_zonelist_order(s); 2757 if (ret == 0) 2758 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN); 2759 2760 return ret; 2761} 2762early_param("numa_zonelist_order", setup_numa_zonelist_order); 2763 2764/* 2765 * sysctl handler for numa_zonelist_order 2766 */ 2767int numa_zonelist_order_handler(ctl_table *table, int write, 2768 void __user *buffer, size_t *length, 2769 loff_t *ppos) 2770{ 2771 char saved_string[NUMA_ZONELIST_ORDER_LEN]; 2772 int ret; 2773 static DEFINE_MUTEX(zl_order_mutex); 2774 2775 mutex_lock(&zl_order_mutex); 2776 if (write) 2777 strcpy(saved_string, (char*)table->data); 2778 ret = proc_dostring(table, write, buffer, length, ppos); 2779 if (ret) 2780 goto out; 2781 if (write) { 2782 int oldval = user_zonelist_order; 2783 if (__parse_numa_zonelist_order((char*)table->data)) { 2784 /* 2785 * bogus value. restore saved string 2786 */ 2787 strncpy((char*)table->data, saved_string, 2788 NUMA_ZONELIST_ORDER_LEN); 2789 user_zonelist_order = oldval; 2790 } else if (oldval != user_zonelist_order) { 2791 mutex_lock(&zonelists_mutex); 2792 build_all_zonelists(NULL); 2793 mutex_unlock(&zonelists_mutex); 2794 } 2795 } 2796out: 2797 mutex_unlock(&zl_order_mutex); 2798 return ret; 2799} 2800 2801 2802#define MAX_NODE_LOAD (nr_online_nodes) 2803static int node_load[MAX_NUMNODES]; 2804 2805/** 2806 * find_next_best_node - find the next node that should appear in a given node's fallback list 2807 * @node: node whose fallback list we're appending 2808 * @used_node_mask: nodemask_t of already used nodes 2809 * 2810 * We use a number of factors to determine which is the next node that should 2811 * appear on a given node's fallback list. The node should not have appeared 2812 * already in @node's fallback list, and it should be the next closest node 2813 * according to the distance array (which contains arbitrary distance values 2814 * from each node to each node in the system), and should also prefer nodes 2815 * with no CPUs, since presumably they'll have very little allocation pressure 2816 * on them otherwise. 2817 * It returns -1 if no node is found. 2818 */ 2819static int find_next_best_node(int node, nodemask_t *used_node_mask) 2820{ 2821 int n, val; 2822 int min_val = INT_MAX; 2823 int best_node = -1; 2824 const struct cpumask *tmp = cpumask_of_node(0); 2825 2826 /* Use the local node if we haven't already */ 2827 if (!node_isset(node, *used_node_mask)) { 2828 node_set(node, *used_node_mask); 2829 return node; 2830 } 2831 2832 for_each_node_state(n, N_HIGH_MEMORY) { 2833 2834 /* Don't want a node to appear more than once */ 2835 if (node_isset(n, *used_node_mask)) 2836 continue; 2837 2838 /* Use the distance array to find the distance */ 2839 val = node_distance(node, n); 2840 2841 /* Penalize nodes under us ("prefer the next node") */ 2842 val += (n < node); 2843 2844 /* Give preference to headless and unused nodes */ 2845 tmp = cpumask_of_node(n); 2846 if (!cpumask_empty(tmp)) 2847 val += PENALTY_FOR_NODE_WITH_CPUS; 2848 2849 /* Slight preference for less loaded node */ 2850 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 2851 val += node_load[n]; 2852 2853 if (val < min_val) { 2854 min_val = val; 2855 best_node = n; 2856 } 2857 } 2858 2859 if (best_node >= 0) 2860 node_set(best_node, *used_node_mask); 2861 2862 return best_node; 2863} 2864 2865 2866/* 2867 * Build zonelists ordered by node and zones within node. 2868 * This results in maximum locality--normal zone overflows into local 2869 * DMA zone, if any--but risks exhausting DMA zone. 2870 */ 2871static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) 2872{ 2873 int j; 2874 struct zonelist *zonelist; 2875 2876 zonelist = &pgdat->node_zonelists[0]; 2877 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++) 2878 ; 2879 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 2880 MAX_NR_ZONES - 1); 2881 zonelist->_zonerefs[j].zone = NULL; 2882 zonelist->_zonerefs[j].zone_idx = 0; 2883} 2884 2885/* 2886 * Build gfp_thisnode zonelists 2887 */ 2888static void build_thisnode_zonelists(pg_data_t *pgdat) 2889{ 2890 int j; 2891 struct zonelist *zonelist; 2892 2893 zonelist = &pgdat->node_zonelists[1]; 2894 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 2895 zonelist->_zonerefs[j].zone = NULL; 2896 zonelist->_zonerefs[j].zone_idx = 0; 2897} 2898 2899/* 2900 * Build zonelists ordered by zone and nodes within zones. 2901 * This results in conserving DMA zone[s] until all Normal memory is 2902 * exhausted, but results in overflowing to remote node while memory 2903 * may still exist in local DMA zone. 2904 */ 2905static int node_order[MAX_NUMNODES]; 2906 2907static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) 2908{ 2909 int pos, j, node; 2910 int zone_type; /* needs to be signed */ 2911 struct zone *z; 2912 struct zonelist *zonelist; 2913 2914 zonelist = &pgdat->node_zonelists[0]; 2915 pos = 0; 2916 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) { 2917 for (j = 0; j < nr_nodes; j++) { 2918 node = node_order[j]; 2919 z = &NODE_DATA(node)->node_zones[zone_type]; 2920 if (populated_zone(z)) { 2921 zoneref_set_zone(z, 2922 &zonelist->_zonerefs[pos++]); 2923 check_highest_zone(zone_type); 2924 } 2925 } 2926 } 2927 zonelist->_zonerefs[pos].zone = NULL; 2928 zonelist->_zonerefs[pos].zone_idx = 0; 2929} 2930 2931static int default_zonelist_order(void) 2932{ 2933 int nid, zone_type; 2934 unsigned long low_kmem_size,total_size; 2935 struct zone *z; 2936 int average_size; 2937 /* 2938 * ZONE_DMA and ZONE_DMA32 can be very small area in the system. 2939 * If they are really small and used heavily, the system can fall 2940 * into OOM very easily. 2941 * This function detect ZONE_DMA/DMA32 size and configures zone order. 2942 */ 2943 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */ 2944 low_kmem_size = 0; 2945 total_size = 0; 2946 for_each_online_node(nid) { 2947 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2948 z = &NODE_DATA(nid)->node_zones[zone_type]; 2949 if (populated_zone(z)) { 2950 if (zone_type < ZONE_NORMAL) 2951 low_kmem_size += z->present_pages; 2952 total_size += z->present_pages; 2953 } else if (zone_type == ZONE_NORMAL) { 2954 /* 2955 * If any node has only lowmem, then node order 2956 * is preferred to allow kernel allocations 2957 * locally; otherwise, they can easily infringe 2958 * on other nodes when there is an abundance of 2959 * lowmem available to allocate from. 2960 */ 2961 return ZONELIST_ORDER_NODE; 2962 } 2963 } 2964 } 2965 if (!low_kmem_size || /* there are no DMA area. */ 2966 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */ 2967 return ZONELIST_ORDER_NODE; 2968 /* 2969 * look into each node's config. 2970 * If there is a node whose DMA/DMA32 memory is very big area on 2971 * local memory, NODE_ORDER may be suitable. 2972 */ 2973 average_size = total_size / 2974 (nodes_weight(node_states[N_HIGH_MEMORY]) + 1); 2975 for_each_online_node(nid) { 2976 low_kmem_size = 0; 2977 total_size = 0; 2978 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 2979 z = &NODE_DATA(nid)->node_zones[zone_type]; 2980 if (populated_zone(z)) { 2981 if (zone_type < ZONE_NORMAL) 2982 low_kmem_size += z->present_pages; 2983 total_size += z->present_pages; 2984 } 2985 } 2986 if (low_kmem_size && 2987 total_size > average_size && /* ignore small node */ 2988 low_kmem_size > total_size * 70/100) 2989 return ZONELIST_ORDER_NODE; 2990 } 2991 return ZONELIST_ORDER_ZONE; 2992} 2993 2994static void set_zonelist_order(void) 2995{ 2996 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT) 2997 current_zonelist_order = default_zonelist_order(); 2998 else 2999 current_zonelist_order = user_zonelist_order; 3000} 3001 3002static void build_zonelists(pg_data_t *pgdat) 3003{ 3004 int j, node, load; 3005 enum zone_type i; 3006 nodemask_t used_mask; 3007 int local_node, prev_node; 3008 struct zonelist *zonelist; 3009 int order = current_zonelist_order; 3010 3011 /* initialize zonelists */ 3012 for (i = 0; i < MAX_ZONELISTS; i++) { 3013 zonelist = pgdat->node_zonelists + i; 3014 zonelist->_zonerefs[0].zone = NULL; 3015 zonelist->_zonerefs[0].zone_idx = 0; 3016 } 3017 3018 /* NUMA-aware ordering of nodes */ 3019 local_node = pgdat->node_id; 3020 load = nr_online_nodes; 3021 prev_node = local_node; 3022 nodes_clear(used_mask); 3023 3024 memset(node_order, 0, sizeof(node_order)); 3025 j = 0; 3026 3027 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 3028 int distance = node_distance(local_node, node); 3029 3030 /* 3031 * If another node is sufficiently far away then it is better 3032 * to reclaim pages in a zone before going off node. 3033 */ 3034 if (distance > RECLAIM_DISTANCE) 3035 zone_reclaim_mode = 1; 3036 3037 /* 3038 * We don't want to pressure a particular node. 3039 * So adding penalty to the first node in same 3040 * distance group to make it round-robin. 3041 */ 3042 if (distance != node_distance(local_node, prev_node)) 3043 node_load[node] = load; 3044 3045 prev_node = node; 3046 load--; 3047 if (order == ZONELIST_ORDER_NODE) 3048 build_zonelists_in_node_order(pgdat, node); 3049 else 3050 node_order[j++] = node; /* remember order */ 3051 } 3052 3053 if (order == ZONELIST_ORDER_ZONE) { 3054 /* calculate node order -- i.e., DMA last! */ 3055 build_zonelists_in_zone_order(pgdat, j); 3056 } 3057 3058 build_thisnode_zonelists(pgdat); 3059} 3060 3061/* Construct the zonelist performance cache - see further mmzone.h */ 3062static void build_zonelist_cache(pg_data_t *pgdat) 3063{ 3064 struct zonelist *zonelist; 3065 struct zonelist_cache *zlc; 3066 struct zoneref *z; 3067 3068 zonelist = &pgdat->node_zonelists[0]; 3069 zonelist->zlcache_ptr = zlc = &zonelist->zlcache; 3070 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 3071 for (z = zonelist->_zonerefs; z->zone; z++) 3072 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z); 3073} 3074 3075#ifdef CONFIG_HAVE_MEMORYLESS_NODES 3076/* 3077 * Return node id of node used for "local" allocations. 3078 * I.e., first node id of first zone in arg node's generic zonelist. 3079 * Used for initializing percpu 'numa_mem', which is used primarily 3080 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist. 3081 */ 3082int local_memory_node(int node) 3083{ 3084 struct zone *zone; 3085 3086 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL), 3087 gfp_zone(GFP_KERNEL), 3088 NULL, 3089 &zone); 3090 return zone->node; 3091} 3092#endif 3093 3094#else /* CONFIG_NUMA */ 3095 3096static void set_zonelist_order(void) 3097{ 3098 current_zonelist_order = ZONELIST_ORDER_ZONE; 3099} 3100 3101static void build_zonelists(pg_data_t *pgdat) 3102{ 3103 int node, local_node; 3104 enum zone_type j; 3105 struct zonelist *zonelist; 3106 3107 local_node = pgdat->node_id; 3108 3109 zonelist = &pgdat->node_zonelists[0]; 3110 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 3111 3112 /* 3113 * Now we build the zonelist so that it contains the zones 3114 * of all the other nodes. 3115 * We don't want to pressure a particular node, so when 3116 * building the zones for node N, we make sure that the 3117 * zones coming right after the local ones are those from 3118 * node N+1 (modulo N) 3119 */ 3120 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 3121 if (!node_online(node)) 3122 continue; 3123 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 3124 MAX_NR_ZONES - 1); 3125 } 3126 for (node = 0; node < local_node; node++) { 3127 if (!node_online(node)) 3128 continue; 3129 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 3130 MAX_NR_ZONES - 1); 3131 } 3132 3133 zonelist->_zonerefs[j].zone = NULL; 3134 zonelist->_zonerefs[j].zone_idx = 0; 3135} 3136 3137/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ 3138static void build_zonelist_cache(pg_data_t *pgdat) 3139{ 3140 pgdat->node_zonelists[0].zlcache_ptr = NULL; 3141} 3142 3143#endif /* CONFIG_NUMA */ 3144 3145/* 3146 * Boot pageset table. One per cpu which is going to be used for all 3147 * zones and all nodes. The parameters will be set in such a way 3148 * that an item put on a list will immediately be handed over to 3149 * the buddy list. This is safe since pageset manipulation is done 3150 * with interrupts disabled. 3151 * 3152 * The boot_pagesets must be kept even after bootup is complete for 3153 * unused processors and/or zones. They do play a role for bootstrapping 3154 * hotplugged processors. 3155 * 3156 * zoneinfo_show() and maybe other functions do 3157 * not check if the processor is online before following the pageset pointer. 3158 * Other parts of the kernel may not check if the zone is available. 3159 */ 3160static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch); 3161static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset); 3162static void setup_zone_pageset(struct zone *zone); 3163 3164/* 3165 * Global mutex to protect against size modification of zonelists 3166 * as well as to serialize pageset setup for the new populated zone. 3167 */ 3168DEFINE_MUTEX(zonelists_mutex); 3169 3170/* return values int ....just for stop_machine() */ 3171static __init_refok int __build_all_zonelists(void *data) 3172{ 3173 int nid; 3174 int cpu; 3175 3176#ifdef CONFIG_NUMA 3177 memset(node_load, 0, sizeof(node_load)); 3178#endif 3179 for_each_online_node(nid) { 3180 pg_data_t *pgdat = NODE_DATA(nid); 3181 3182 build_zonelists(pgdat); 3183 build_zonelist_cache(pgdat); 3184 } 3185 3186 /* 3187 * Initialize the boot_pagesets that are going to be used 3188 * for bootstrapping processors. The real pagesets for 3189 * each zone will be allocated later when the per cpu 3190 * allocator is available. 3191 * 3192 * boot_pagesets are used also for bootstrapping offline 3193 * cpus if the system is already booted because the pagesets 3194 * are needed to initialize allocators on a specific cpu too. 3195 * F.e. the percpu allocator needs the page allocator which 3196 * needs the percpu allocator in order to allocate its pagesets 3197 * (a chicken-egg dilemma). 3198 */ 3199 for_each_possible_cpu(cpu) { 3200 setup_pageset(&per_cpu(boot_pageset, cpu), 0); 3201 3202#ifdef CONFIG_HAVE_MEMORYLESS_NODES 3203 /* 3204 * We now know the "local memory node" for each node-- 3205 * i.e., the node of the first zone in the generic zonelist. 3206 * Set up numa_mem percpu variable for on-line cpus. During 3207 * boot, only the boot cpu should be on-line; we'll init the 3208 * secondary cpus' numa_mem as they come on-line. During 3209 * node/memory hotplug, we'll fixup all on-line cpus. 3210 */ 3211 if (cpu_online(cpu)) 3212 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu))); 3213#endif 3214 } 3215 3216 return 0; 3217} 3218 3219/* 3220 * Called with zonelists_mutex held always 3221 * unless system_state == SYSTEM_BOOTING. 3222 */ 3223void __ref build_all_zonelists(void *data) 3224{ 3225 set_zonelist_order(); 3226 3227 if (system_state == SYSTEM_BOOTING) { 3228 __build_all_zonelists(NULL); 3229 mminit_verify_zonelist(); 3230 cpuset_init_current_mems_allowed(); 3231 } else { 3232 /* we have to stop all cpus to guarantee there is no user 3233 of zonelist */ 3234#ifdef CONFIG_MEMORY_HOTPLUG 3235 if (data) 3236 setup_zone_pageset((struct zone *)data); 3237#endif 3238 stop_machine(__build_all_zonelists, NULL, NULL); 3239 /* cpuset refresh routine should be here */ 3240 } 3241 vm_total_pages = nr_free_pagecache_pages(); 3242 /* 3243 * Disable grouping by mobility if the number of pages in the 3244 * system is too low to allow the mechanism to work. It would be 3245 * more accurate, but expensive to check per-zone. This check is 3246 * made on memory-hotadd so a system can start with mobility 3247 * disabled and enable it later 3248 */ 3249 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) 3250 page_group_by_mobility_disabled = 1; 3251 else 3252 page_group_by_mobility_disabled = 0; 3253 3254 printk("Built %i zonelists in %s order, mobility grouping %s. " 3255 "Total pages: %ld\n", 3256 nr_online_nodes, 3257 zonelist_order_name[current_zonelist_order], 3258 page_group_by_mobility_disabled ? "off" : "on", 3259 vm_total_pages); 3260#ifdef CONFIG_NUMA 3261 printk("Policy zone: %s\n", zone_names[policy_zone]); 3262#endif 3263} 3264 3265/* 3266 * Helper functions to size the waitqueue hash table. 3267 * Essentially these want to choose hash table sizes sufficiently 3268 * large so that collisions trying to wait on pages are rare. 3269 * But in fact, the number of active page waitqueues on typical 3270 * systems is ridiculously low, less than 200. So this is even 3271 * conservative, even though it seems large. 3272 * 3273 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 3274 * waitqueues, i.e. the size of the waitq table given the number of pages. 3275 */ 3276#define PAGES_PER_WAITQUEUE 256 3277 3278#ifndef CONFIG_MEMORY_HOTPLUG 3279static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 3280{ 3281 unsigned long size = 1; 3282 3283 pages /= PAGES_PER_WAITQUEUE; 3284 3285 while (size < pages) 3286 size <<= 1; 3287 3288 /* 3289 * Once we have dozens or even hundreds of threads sleeping 3290 * on IO we've got bigger problems than wait queue collision. 3291 * Limit the size of the wait table to a reasonable size. 3292 */ 3293 size = min(size, 4096UL); 3294 3295 return max(size, 4UL); 3296} 3297#else 3298/* 3299 * A zone's size might be changed by hot-add, so it is not possible to determine 3300 * a suitable size for its wait_table. So we use the maximum size now. 3301 * 3302 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: 3303 * 3304 * i386 (preemption config) : 4096 x 16 = 64Kbyte. 3305 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. 3306 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. 3307 * 3308 * The maximum entries are prepared when a zone's memory is (512K + 256) pages 3309 * or more by the traditional way. (See above). It equals: 3310 * 3311 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. 3312 * ia64(16K page size) : = ( 8G + 4M)byte. 3313 * powerpc (64K page size) : = (32G +16M)byte. 3314 */ 3315static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 3316{ 3317 return 4096UL; 3318} 3319#endif 3320 3321/* 3322 * This is an integer logarithm so that shifts can be used later 3323 * to extract the more random high bits from the multiplicative 3324 * hash function before the remainder is taken. 3325 */ 3326static inline unsigned long wait_table_bits(unsigned long size) 3327{ 3328 return ffz(~size); 3329} 3330 3331#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) 3332 3333/* 3334 * Check if a pageblock contains reserved pages 3335 */ 3336static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn) 3337{ 3338 unsigned long pfn; 3339 3340 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 3341 if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn))) 3342 return 1; 3343 } 3344 return 0; 3345} 3346 3347/* 3348 * Mark a number of pageblocks as MIGRATE_RESERVE. The number 3349 * of blocks reserved is based on min_wmark_pages(zone). The memory within 3350 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes 3351 * higher will lead to a bigger reserve which will get freed as contiguous 3352 * blocks as reclaim kicks in 3353 */ 3354static void setup_zone_migrate_reserve(struct zone *zone) 3355{ 3356 unsigned long start_pfn, pfn, end_pfn, block_end_pfn; 3357 struct page *page; 3358 unsigned long block_migratetype; 3359 int reserve; 3360 3361 /* 3362 * Get the start pfn, end pfn and the number of blocks to reserve 3363 * We have to be careful to be aligned to pageblock_nr_pages to 3364 * make sure that we always check pfn_valid for the first page in 3365 * the block. 3366 */ 3367 start_pfn = zone->zone_start_pfn; 3368 end_pfn = start_pfn + zone->spanned_pages; 3369 start_pfn = roundup(start_pfn, pageblock_nr_pages); 3370 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >> 3371 pageblock_order; 3372 3373 /* 3374 * Reserve blocks are generally in place to help high-order atomic 3375 * allocations that are short-lived. A min_free_kbytes value that 3376 * would result in more than 2 reserve blocks for atomic allocations 3377 * is assumed to be in place to help anti-fragmentation for the 3378 * future allocation of hugepages at runtime. 3379 */ 3380 reserve = min(2, reserve); 3381 3382 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 3383 if (!pfn_valid(pfn)) 3384 continue; 3385 page = pfn_to_page(pfn); 3386 3387 /* Watch out for overlapping nodes */ 3388 if (page_to_nid(page) != zone_to_nid(zone)) 3389 continue; 3390 3391 block_migratetype = get_pageblock_migratetype(page); 3392 3393 /* Only test what is necessary when the reserves are not met */ 3394 if (reserve > 0) { 3395 /* 3396 * Blocks with reserved pages will never free, skip 3397 * them. 3398 */ 3399 block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn); 3400 if (pageblock_is_reserved(pfn, block_end_pfn)) 3401 continue; 3402 3403 /* If this block is reserved, account for it */ 3404 if (block_migratetype == MIGRATE_RESERVE) { 3405 reserve--; 3406 continue; 3407 } 3408 3409 /* Suitable for reserving if this block is movable */ 3410 if (block_migratetype == MIGRATE_MOVABLE) { 3411 set_pageblock_migratetype(page, 3412 MIGRATE_RESERVE); 3413 move_freepages_block(zone, page, 3414 MIGRATE_RESERVE); 3415 reserve--; 3416 continue; 3417 } 3418 } 3419 3420 /* 3421 * If the reserve is met and this is a previous reserved block, 3422 * take it back 3423 */ 3424 if (block_migratetype == MIGRATE_RESERVE) { 3425 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 3426 move_freepages_block(zone, page, MIGRATE_MOVABLE); 3427 } 3428 } 3429} 3430 3431/* 3432 * Initially all pages are reserved - free ones are freed 3433 * up by free_all_bootmem() once the early boot process is 3434 * done. Non-atomic initialization, single-pass. 3435 */ 3436void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 3437 unsigned long start_pfn, enum memmap_context context) 3438{ 3439 struct page *page; 3440 unsigned long end_pfn = start_pfn + size; 3441 unsigned long pfn; 3442 struct zone *z; 3443 3444 if (highest_memmap_pfn < end_pfn - 1) 3445 highest_memmap_pfn = end_pfn - 1; 3446 3447 z = &NODE_DATA(nid)->node_zones[zone]; 3448 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 3449 /* 3450 * There can be holes in boot-time mem_map[]s 3451 * handed to this function. They do not 3452 * exist on hotplugged memory. 3453 */ 3454 if (context == MEMMAP_EARLY) { 3455 if (!early_pfn_valid(pfn)) 3456 continue; 3457 if (!early_pfn_in_nid(pfn, nid)) 3458 continue; 3459 } 3460 page = pfn_to_page(pfn); 3461 set_page_links(page, zone, nid, pfn); 3462 mminit_verify_page_links(page, zone, nid, pfn); 3463 init_page_count(page); 3464 reset_page_mapcount(page); 3465 SetPageReserved(page); 3466 /* 3467 * Mark the block movable so that blocks are reserved for 3468 * movable at startup. This will force kernel allocations 3469 * to reserve their blocks rather than leaking throughout 3470 * the address space during boot when many long-lived 3471 * kernel allocations are made. Later some blocks near 3472 * the start are marked MIGRATE_RESERVE by 3473 * setup_zone_migrate_reserve() 3474 * 3475 * bitmap is created for zone's valid pfn range. but memmap 3476 * can be created for invalid pages (for alignment) 3477 * check here not to call set_pageblock_migratetype() against 3478 * pfn out of zone. 3479 */ 3480 if ((z->zone_start_pfn <= pfn) 3481 && (pfn < z->zone_start_pfn + z->spanned_pages) 3482 && !(pfn & (pageblock_nr_pages - 1))) 3483 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 3484 3485 INIT_LIST_HEAD(&page->lru); 3486#ifdef WANT_PAGE_VIRTUAL 3487 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 3488 if (!is_highmem_idx(zone)) 3489 set_page_address(page, __va(pfn << PAGE_SHIFT)); 3490#endif 3491 } 3492} 3493 3494static void __meminit zone_init_free_lists(struct zone *zone) 3495{ 3496 int order, t; 3497 for_each_migratetype_order(order, t) { 3498 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); 3499 zone->free_area[order].nr_free = 0; 3500 } 3501} 3502 3503#ifndef __HAVE_ARCH_MEMMAP_INIT 3504#define memmap_init(size, nid, zone, start_pfn) \ 3505 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) 3506#endif 3507 3508static int zone_batchsize(struct zone *zone) 3509{ 3510#ifdef CONFIG_MMU 3511 int batch; 3512 3513 /* 3514 * The per-cpu-pages pools are set to around 1000th of the 3515 * size of the zone. But no more than 1/2 of a meg. 3516 * 3517 * OK, so we don't know how big the cache is. So guess. 3518 */ 3519 batch = zone->present_pages / 1024; 3520 if (batch * PAGE_SIZE > 512 * 1024) 3521 batch = (512 * 1024) / PAGE_SIZE; 3522 batch /= 4; /* We effectively *= 4 below */ 3523 if (batch < 1) 3524 batch = 1; 3525 3526 /* 3527 * Clamp the batch to a 2^n - 1 value. Having a power 3528 * of 2 value was found to be more likely to have 3529 * suboptimal cache aliasing properties in some cases. 3530 * 3531 * For example if 2 tasks are alternately allocating 3532 * batches of pages, one task can end up with a lot 3533 * of pages of one half of the possible page colors 3534 * and the other with pages of the other colors. 3535 */ 3536 batch = rounddown_pow_of_two(batch + batch/2) - 1; 3537 3538 return batch; 3539 3540#else 3541 /* The deferral and batching of frees should be suppressed under NOMMU 3542 * conditions. 3543 * 3544 * The problem is that NOMMU needs to be able to allocate large chunks 3545 * of contiguous memory as there's no hardware page translation to 3546 * assemble apparent contiguous memory from discontiguous pages. 3547 * 3548 * Queueing large contiguous runs of pages for batching, however, 3549 * causes the pages to actually be freed in smaller chunks. As there 3550 * can be a significant delay between the individual batches being 3551 * recycled, this leads to the once large chunks of space being 3552 * fragmented and becoming unavailable for high-order allocations. 3553 */ 3554 return 0; 3555#endif 3556} 3557 3558static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 3559{ 3560 struct per_cpu_pages *pcp; 3561 int migratetype; 3562 3563 memset(p, 0, sizeof(*p)); 3564 3565 pcp = &p->pcp; 3566 pcp->count = 0; 3567 pcp->high = 6 * batch; 3568 pcp->batch = max(1UL, 1 * batch); 3569 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++) 3570 INIT_LIST_HEAD(&pcp->lists[migratetype]); 3571} 3572 3573/* 3574 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist 3575 * to the value high for the pageset p. 3576 */ 3577 3578static void setup_pagelist_highmark(struct per_cpu_pageset *p, 3579 unsigned long high) 3580{ 3581 struct per_cpu_pages *pcp; 3582 3583 pcp = &p->pcp; 3584 pcp->high = high; 3585 pcp->batch = max(1UL, high/4); 3586 if ((high/4) > (PAGE_SHIFT * 8)) 3587 pcp->batch = PAGE_SHIFT * 8; 3588} 3589 3590static void setup_zone_pageset(struct zone *zone) 3591{ 3592 int cpu; 3593 3594 zone->pageset = alloc_percpu(struct per_cpu_pageset); 3595 3596 for_each_possible_cpu(cpu) { 3597 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu); 3598 3599 setup_pageset(pcp, zone_batchsize(zone)); 3600 3601 if (percpu_pagelist_fraction) 3602 setup_pagelist_highmark(pcp, 3603 (zone->present_pages / 3604 percpu_pagelist_fraction)); 3605 } 3606} 3607 3608/* 3609 * Allocate per cpu pagesets and initialize them. 3610 * Before this call only boot pagesets were available. 3611 */ 3612void __init setup_per_cpu_pageset(void) 3613{ 3614 struct zone *zone; 3615 3616 for_each_populated_zone(zone) 3617 setup_zone_pageset(zone); 3618} 3619 3620static noinline __init_refok 3621int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 3622{ 3623 int i; 3624 struct pglist_data *pgdat = zone->zone_pgdat; 3625 size_t alloc_size; 3626 3627 /* 3628 * The per-page waitqueue mechanism uses hashed waitqueues 3629 * per zone. 3630 */ 3631 zone->wait_table_hash_nr_entries = 3632 wait_table_hash_nr_entries(zone_size_pages); 3633 zone->wait_table_bits = 3634 wait_table_bits(zone->wait_table_hash_nr_entries); 3635 alloc_size = zone->wait_table_hash_nr_entries 3636 * sizeof(wait_queue_head_t); 3637 3638 if (!slab_is_available()) { 3639 zone->wait_table = (wait_queue_head_t *) 3640 alloc_bootmem_node_nopanic(pgdat, alloc_size); 3641 } else { 3642 /* 3643 * This case means that a zone whose size was 0 gets new memory 3644 * via memory hot-add. 3645 * But it may be the case that a new node was hot-added. In 3646 * this case vmalloc() will not be able to use this new node's 3647 * memory - this wait_table must be initialized to use this new 3648 * node itself as well. 3649 * To use this new node's memory, further consideration will be 3650 * necessary. 3651 */ 3652 zone->wait_table = vmalloc(alloc_size); 3653 } 3654 if (!zone->wait_table) 3655 return -ENOMEM; 3656 3657 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i) 3658 init_waitqueue_head(zone->wait_table + i); 3659 3660 return 0; 3661} 3662 3663static int __zone_pcp_update(void *data) 3664{ 3665 struct zone *zone = data; 3666 int cpu; 3667 unsigned long batch = zone_batchsize(zone), flags; 3668 3669 for_each_possible_cpu(cpu) { 3670 struct per_cpu_pageset *pset; 3671 struct per_cpu_pages *pcp; 3672 3673 pset = per_cpu_ptr(zone->pageset, cpu); 3674 pcp = &pset->pcp; 3675 3676 local_irq_save(flags); 3677 free_pcppages_bulk(zone, pcp->count, pcp); 3678 setup_pageset(pset, batch); 3679 local_irq_restore(flags); 3680 } 3681 return 0; 3682} 3683 3684void zone_pcp_update(struct zone *zone) 3685{ 3686 stop_machine(__zone_pcp_update, zone, NULL); 3687} 3688 3689static __meminit void zone_pcp_init(struct zone *zone) 3690{ 3691 /* 3692 * per cpu subsystem is not up at this point. The following code 3693 * relies on the ability of the linker to provide the 3694 * offset of a (static) per cpu variable into the per cpu area. 3695 */ 3696 zone->pageset = &boot_pageset; 3697 3698 if (zone->present_pages) 3699 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n", 3700 zone->name, zone->present_pages, 3701 zone_batchsize(zone)); 3702} 3703 3704__meminit int init_currently_empty_zone(struct zone *zone, 3705 unsigned long zone_start_pfn, 3706 unsigned long size, 3707 enum memmap_context context) 3708{ 3709 struct pglist_data *pgdat = zone->zone_pgdat; 3710 int ret; 3711 ret = zone_wait_table_init(zone, size); 3712 if (ret) 3713 return ret; 3714 pgdat->nr_zones = zone_idx(zone) + 1; 3715 3716 zone->zone_start_pfn = zone_start_pfn; 3717 3718 mminit_dprintk(MMINIT_TRACE, "memmap_init", 3719 "Initialising map node %d zone %lu pfns %lu -> %lu\n", 3720 pgdat->node_id, 3721 (unsigned long)zone_idx(zone), 3722 zone_start_pfn, (zone_start_pfn + size)); 3723 3724 zone_init_free_lists(zone); 3725 3726 return 0; 3727} 3728 3729#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 3730#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID 3731/* 3732 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. 3733 * Architectures may implement their own version but if add_active_range() 3734 * was used and there are no special requirements, this is a convenient 3735 * alternative 3736 */ 3737int __meminit __early_pfn_to_nid(unsigned long pfn) 3738{ 3739 unsigned long start_pfn, end_pfn; 3740 int i, nid; 3741 3742 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) 3743 if (start_pfn <= pfn && pfn < end_pfn) 3744 return nid; 3745 /* This is a memory hole */ 3746 return -1; 3747} 3748#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ 3749 3750int __meminit early_pfn_to_nid(unsigned long pfn) 3751{ 3752 int nid; 3753 3754 nid = __early_pfn_to_nid(pfn); 3755 if (nid >= 0) 3756 return nid; 3757 /* just returns 0 */ 3758 return 0; 3759} 3760 3761#ifdef CONFIG_NODES_SPAN_OTHER_NODES 3762bool __meminit early_pfn_in_nid(unsigned long pfn, int node) 3763{ 3764 int nid; 3765 3766 nid = __early_pfn_to_nid(pfn); 3767 if (nid >= 0 && nid != node) 3768 return false; 3769 return true; 3770} 3771#endif 3772 3773/** 3774 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range 3775 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. 3776 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node 3777 * 3778 * If an architecture guarantees that all ranges registered with 3779 * add_active_ranges() contain no holes and may be freed, this 3780 * this function may be used instead of calling free_bootmem() manually. 3781 */ 3782void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn) 3783{ 3784 unsigned long start_pfn, end_pfn; 3785 int i, this_nid; 3786 3787 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) { 3788 start_pfn = min(start_pfn, max_low_pfn); 3789 end_pfn = min(end_pfn, max_low_pfn); 3790 3791 if (start_pfn < end_pfn) 3792 free_bootmem_node(NODE_DATA(this_nid), 3793 PFN_PHYS(start_pfn), 3794 (end_pfn - start_pfn) << PAGE_SHIFT); 3795 } 3796} 3797 3798int __init add_from_early_node_map(struct range *range, int az, 3799 int nr_range, int nid) 3800{ 3801 unsigned long start_pfn, end_pfn; 3802 int i; 3803 3804 /* need to go over early_node_map to find out good range for node */ 3805 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) 3806 nr_range = add_range(range, az, nr_range, start_pfn, end_pfn); 3807 return nr_range; 3808} 3809 3810/** 3811 * sparse_memory_present_with_active_regions - Call memory_present for each active range 3812 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. 3813 * 3814 * If an architecture guarantees that all ranges registered with 3815 * add_active_ranges() contain no holes and may be freed, this 3816 * function may be used instead of calling memory_present() manually. 3817 */ 3818void __init sparse_memory_present_with_active_regions(int nid) 3819{ 3820 unsigned long start_pfn, end_pfn; 3821 int i, this_nid; 3822 3823 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) 3824 memory_present(this_nid, start_pfn, end_pfn); 3825} 3826 3827/** 3828 * get_pfn_range_for_nid - Return the start and end page frames for a node 3829 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. 3830 * @start_pfn: Passed by reference. On return, it will have the node start_pfn. 3831 * @end_pfn: Passed by reference. On return, it will have the node end_pfn. 3832 * 3833 * It returns the start and end page frame of a node based on information 3834 * provided by an arch calling add_active_range(). If called for a node 3835 * with no available memory, a warning is printed and the start and end 3836 * PFNs will be 0. 3837 */ 3838void __meminit get_pfn_range_for_nid(unsigned int nid, 3839 unsigned long *start_pfn, unsigned long *end_pfn) 3840{ 3841 unsigned long this_start_pfn, this_end_pfn; 3842 int i; 3843 3844 *start_pfn = -1UL; 3845 *end_pfn = 0; 3846 3847 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) { 3848 *start_pfn = min(*start_pfn, this_start_pfn); 3849 *end_pfn = max(*end_pfn, this_end_pfn); 3850 } 3851 3852 if (*start_pfn == -1UL) 3853 *start_pfn = 0; 3854} 3855 3856/* 3857 * This finds a zone that can be used for ZONE_MOVABLE pages. The 3858 * assumption is made that zones within a node are ordered in monotonic 3859 * increasing memory addresses so that the "highest" populated zone is used 3860 */ 3861static void __init find_usable_zone_for_movable(void) 3862{ 3863 int zone_index; 3864 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { 3865 if (zone_index == ZONE_MOVABLE) 3866 continue; 3867 3868 if (arch_zone_highest_possible_pfn[zone_index] > 3869 arch_zone_lowest_possible_pfn[zone_index]) 3870 break; 3871 } 3872 3873 VM_BUG_ON(zone_index == -1); 3874 movable_zone = zone_index; 3875} 3876 3877/* 3878 * The zone ranges provided by the architecture do not include ZONE_MOVABLE 3879 * because it is sized independent of architecture. Unlike the other zones, 3880 * the starting point for ZONE_MOVABLE is not fixed. It may be different 3881 * in each node depending on the size of each node and how evenly kernelcore 3882 * is distributed. This helper function adjusts the zone ranges 3883 * provided by the architecture for a given node by using the end of the 3884 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that 3885 * zones within a node are in order of monotonic increases memory addresses 3886 */ 3887static void __meminit adjust_zone_range_for_zone_movable(int nid, 3888 unsigned long zone_type, 3889 unsigned long node_start_pfn, 3890 unsigned long node_end_pfn, 3891 unsigned long *zone_start_pfn, 3892 unsigned long *zone_end_pfn) 3893{ 3894 /* Only adjust if ZONE_MOVABLE is on this node */ 3895 if (zone_movable_pfn[nid]) { 3896 /* Size ZONE_MOVABLE */ 3897 if (zone_type == ZONE_MOVABLE) { 3898 *zone_start_pfn = zone_movable_pfn[nid]; 3899 *zone_end_pfn = min(node_end_pfn, 3900 arch_zone_highest_possible_pfn[movable_zone]); 3901 3902 /* Adjust for ZONE_MOVABLE starting within this range */ 3903 } else if (*zone_start_pfn < zone_movable_pfn[nid] && 3904 *zone_end_pfn > zone_movable_pfn[nid]) { 3905 *zone_end_pfn = zone_movable_pfn[nid]; 3906 3907 /* Check if this whole range is within ZONE_MOVABLE */ 3908 } else if (*zone_start_pfn >= zone_movable_pfn[nid]) 3909 *zone_start_pfn = *zone_end_pfn; 3910 } 3911} 3912 3913/* 3914 * Return the number of pages a zone spans in a node, including holes 3915 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() 3916 */ 3917static unsigned long __meminit zone_spanned_pages_in_node(int nid, 3918 unsigned long zone_type, 3919 unsigned long *ignored) 3920{ 3921 unsigned long node_start_pfn, node_end_pfn; 3922 unsigned long zone_start_pfn, zone_end_pfn; 3923 3924 /* Get the start and end of the node and zone */ 3925 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3926 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; 3927 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; 3928 adjust_zone_range_for_zone_movable(nid, zone_type, 3929 node_start_pfn, node_end_pfn, 3930 &zone_start_pfn, &zone_end_pfn); 3931 3932 /* Check that this node has pages within the zone's required range */ 3933 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) 3934 return 0; 3935 3936 /* Move the zone boundaries inside the node if necessary */ 3937 zone_end_pfn = min(zone_end_pfn, node_end_pfn); 3938 zone_start_pfn = max(zone_start_pfn, node_start_pfn); 3939 3940 /* Return the spanned pages */ 3941 return zone_end_pfn - zone_start_pfn; 3942} 3943 3944/* 3945 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, 3946 * then all holes in the requested range will be accounted for. 3947 */ 3948unsigned long __meminit __absent_pages_in_range(int nid, 3949 unsigned long range_start_pfn, 3950 unsigned long range_end_pfn) 3951{ 3952 unsigned long nr_absent = range_end_pfn - range_start_pfn; 3953 unsigned long start_pfn, end_pfn; 3954 int i; 3955 3956 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { 3957 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn); 3958 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn); 3959 nr_absent -= end_pfn - start_pfn; 3960 } 3961 return nr_absent; 3962} 3963 3964/** 3965 * absent_pages_in_range - Return number of page frames in holes within a range 3966 * @start_pfn: The start PFN to start searching for holes 3967 * @end_pfn: The end PFN to stop searching for holes 3968 * 3969 * It returns the number of pages frames in memory holes within a range. 3970 */ 3971unsigned long __init absent_pages_in_range(unsigned long start_pfn, 3972 unsigned long end_pfn) 3973{ 3974 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); 3975} 3976 3977/* Return the number of page frames in holes in a zone on a node */ 3978static unsigned long __meminit zone_absent_pages_in_node(int nid, 3979 unsigned long zone_type, 3980 unsigned long *ignored) 3981{ 3982 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type]; 3983 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type]; 3984 unsigned long node_start_pfn, node_end_pfn; 3985 unsigned long zone_start_pfn, zone_end_pfn; 3986 3987 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 3988 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high); 3989 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high); 3990 3991 adjust_zone_range_for_zone_movable(nid, zone_type, 3992 node_start_pfn, node_end_pfn, 3993 &zone_start_pfn, &zone_end_pfn); 3994 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); 3995} 3996 3997#else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 3998static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, 3999 unsigned long zone_type, 4000 unsigned long *zones_size) 4001{ 4002 return zones_size[zone_type]; 4003} 4004 4005static inline unsigned long __meminit zone_absent_pages_in_node(int nid, 4006 unsigned long zone_type, 4007 unsigned long *zholes_size) 4008{ 4009 if (!zholes_size) 4010 return 0; 4011 4012 return zholes_size[zone_type]; 4013} 4014 4015#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 4016 4017static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, 4018 unsigned long *zones_size, unsigned long *zholes_size) 4019{ 4020 unsigned long realtotalpages, totalpages = 0; 4021 enum zone_type i; 4022 4023 for (i = 0; i < MAX_NR_ZONES; i++) 4024 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i, 4025 zones_size); 4026 pgdat->node_spanned_pages = totalpages; 4027 4028 realtotalpages = totalpages; 4029 for (i = 0; i < MAX_NR_ZONES; i++) 4030 realtotalpages -= 4031 zone_absent_pages_in_node(pgdat->node_id, i, 4032 zholes_size); 4033 pgdat->node_present_pages = realtotalpages; 4034 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, 4035 realtotalpages); 4036} 4037 4038#ifndef CONFIG_SPARSEMEM 4039/* 4040 * Calculate the size of the zone->blockflags rounded to an unsigned long 4041 * Start by making sure zonesize is a multiple of pageblock_order by rounding 4042 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally 4043 * round what is now in bits to nearest long in bits, then return it in 4044 * bytes. 4045 */ 4046static unsigned long __init usemap_size(unsigned long zonesize) 4047{ 4048 unsigned long usemapsize; 4049 4050 usemapsize = roundup(zonesize, pageblock_nr_pages); 4051 usemapsize = usemapsize >> pageblock_order; 4052 usemapsize *= NR_PAGEBLOCK_BITS; 4053 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); 4054 4055 return usemapsize / 8; 4056} 4057 4058static void __init setup_usemap(struct pglist_data *pgdat, 4059 struct zone *zone, unsigned long zonesize) 4060{ 4061 unsigned long usemapsize = usemap_size(zonesize); 4062 zone->pageblock_flags = NULL; 4063 if (usemapsize) 4064 zone->pageblock_flags = alloc_bootmem_node_nopanic(pgdat, 4065 usemapsize); 4066} 4067#else 4068static inline void setup_usemap(struct pglist_data *pgdat, 4069 struct zone *zone, unsigned long zonesize) {} 4070#endif /* CONFIG_SPARSEMEM */ 4071 4072#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 4073 4074/* Return a sensible default order for the pageblock size. */ 4075static inline int pageblock_default_order(void) 4076{ 4077 if (HPAGE_SHIFT > PAGE_SHIFT) 4078 return HUGETLB_PAGE_ORDER; 4079 4080 return MAX_ORDER-1; 4081} 4082 4083/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ 4084static inline void __init set_pageblock_order(unsigned int order) 4085{ 4086 /* Check that pageblock_nr_pages has not already been setup */ 4087 if (pageblock_order) 4088 return; 4089 4090 /* 4091 * Assume the largest contiguous order of interest is a huge page. 4092 * This value may be variable depending on boot parameters on IA64 4093 */ 4094 pageblock_order = order; 4095} 4096#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 4097 4098/* 4099 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() 4100 * and pageblock_default_order() are unused as pageblock_order is set 4101 * at compile-time. See include/linux/pageblock-flags.h for the values of 4102 * pageblock_order based on the kernel config 4103 */ 4104static inline int pageblock_default_order(unsigned int order) 4105{ 4106 return MAX_ORDER-1; 4107} 4108#define set_pageblock_order(x) do {} while (0) 4109 4110#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 4111 4112/* 4113 * Set up the zone data structures: 4114 * - mark all pages reserved 4115 * - mark all memory queues empty 4116 * - clear the memory bitmaps 4117 */ 4118static void __paginginit free_area_init_core(struct pglist_data *pgdat, 4119 unsigned long *zones_size, unsigned long *zholes_size) 4120{ 4121 enum zone_type j; 4122 int nid = pgdat->node_id; 4123 unsigned long zone_start_pfn = pgdat->node_start_pfn; 4124 int ret; 4125 4126 pgdat_resize_init(pgdat); 4127 pgdat->nr_zones = 0; 4128 init_waitqueue_head(&pgdat->kswapd_wait); 4129 pgdat->kswapd_max_order = 0; 4130 pgdat_page_cgroup_init(pgdat); 4131 4132 for (j = 0; j < MAX_NR_ZONES; j++) { 4133 struct zone *zone = pgdat->node_zones + j; 4134 unsigned long size, realsize, memmap_pages; 4135 enum lru_list l; 4136 4137 size = zone_spanned_pages_in_node(nid, j, zones_size); 4138 realsize = size - zone_absent_pages_in_node(nid, j, 4139 zholes_size); 4140 4141 /* 4142 * Adjust realsize so that it accounts for how much memory 4143 * is used by this zone for memmap. This affects the watermark 4144 * and per-cpu initialisations 4145 */ 4146 memmap_pages = 4147 PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT; 4148 if (realsize >= memmap_pages) { 4149 realsize -= memmap_pages; 4150 if (memmap_pages) 4151 printk(KERN_DEBUG 4152 " %s zone: %lu pages used for memmap\n", 4153 zone_names[j], memmap_pages); 4154 } else 4155 printk(KERN_WARNING 4156 " %s zone: %lu pages exceeds realsize %lu\n", 4157 zone_names[j], memmap_pages, realsize); 4158 4159 /* Account for reserved pages */ 4160 if (j == 0 && realsize > dma_reserve) { 4161 realsize -= dma_reserve; 4162 printk(KERN_DEBUG " %s zone: %lu pages reserved\n", 4163 zone_names[0], dma_reserve); 4164 } 4165 4166 if (!is_highmem_idx(j)) 4167 nr_kernel_pages += realsize; 4168 nr_all_pages += realsize; 4169 4170 zone->spanned_pages = size; 4171 zone->present_pages = realsize; 4172#ifdef CONFIG_NUMA 4173 zone->node = nid; 4174 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio) 4175 / 100; 4176 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100; 4177#endif 4178 zone->name = zone_names[j]; 4179 spin_lock_init(&zone->lock); 4180 spin_lock_init(&zone->lru_lock); 4181 zone_seqlock_init(zone); 4182 zone->zone_pgdat = pgdat; 4183 4184 zone_pcp_init(zone); 4185 for_each_lru(l) 4186 INIT_LIST_HEAD(&zone->lru[l].list); 4187 zone->reclaim_stat.recent_rotated[0] = 0; 4188 zone->reclaim_stat.recent_rotated[1] = 0; 4189 zone->reclaim_stat.recent_scanned[0] = 0; 4190 zone->reclaim_stat.recent_scanned[1] = 0; 4191 zap_zone_vm_stats(zone); 4192 zone->flags = 0; 4193 if (!size) 4194 continue; 4195 4196 set_pageblock_order(pageblock_default_order()); 4197 setup_usemap(pgdat, zone, size); 4198 ret = init_currently_empty_zone(zone, zone_start_pfn, 4199 size, MEMMAP_EARLY); 4200 BUG_ON(ret); 4201 memmap_init(size, nid, j, zone_start_pfn); 4202 zone_start_pfn += size; 4203 } 4204} 4205 4206static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat) 4207{ 4208 /* Skip empty nodes */ 4209 if (!pgdat->node_spanned_pages) 4210 return; 4211 4212#ifdef CONFIG_FLAT_NODE_MEM_MAP 4213 /* ia64 gets its own node_mem_map, before this, without bootmem */ 4214 if (!pgdat->node_mem_map) { 4215 unsigned long size, start, end; 4216 struct page *map; 4217 4218 /* 4219 * The zone's endpoints aren't required to be MAX_ORDER 4220 * aligned but the node_mem_map endpoints must be in order 4221 * for the buddy allocator to function correctly. 4222 */ 4223 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); 4224 end = pgdat->node_start_pfn + pgdat->node_spanned_pages; 4225 end = ALIGN(end, MAX_ORDER_NR_PAGES); 4226 size = (end - start) * sizeof(struct page); 4227 map = alloc_remap(pgdat->node_id, size); 4228 if (!map) 4229 map = alloc_bootmem_node_nopanic(pgdat, size); 4230 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); 4231 } 4232#ifndef CONFIG_NEED_MULTIPLE_NODES 4233 /* 4234 * With no DISCONTIG, the global mem_map is just set as node 0's 4235 */ 4236 if (pgdat == NODE_DATA(0)) { 4237 mem_map = NODE_DATA(0)->node_mem_map; 4238#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 4239 if (page_to_pfn(mem_map) != pgdat->node_start_pfn) 4240 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET); 4241#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 4242 } 4243#endif 4244#endif /* CONFIG_FLAT_NODE_MEM_MAP */ 4245} 4246 4247void __paginginit free_area_init_node(int nid, unsigned long *zones_size, 4248 unsigned long node_start_pfn, unsigned long *zholes_size) 4249{ 4250 pg_data_t *pgdat = NODE_DATA(nid); 4251 4252 pgdat->node_id = nid; 4253 pgdat->node_start_pfn = node_start_pfn; 4254 calculate_node_totalpages(pgdat, zones_size, zholes_size); 4255 4256 alloc_node_mem_map(pgdat); 4257#ifdef CONFIG_FLAT_NODE_MEM_MAP 4258 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n", 4259 nid, (unsigned long)pgdat, 4260 (unsigned long)pgdat->node_mem_map); 4261#endif 4262 4263 free_area_init_core(pgdat, zones_size, zholes_size); 4264} 4265 4266#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 4267 4268#if MAX_NUMNODES > 1 4269/* 4270 * Figure out the number of possible node ids. 4271 */ 4272static void __init setup_nr_node_ids(void) 4273{ 4274 unsigned int node; 4275 unsigned int highest = 0; 4276 4277 for_each_node_mask(node, node_possible_map) 4278 highest = node; 4279 nr_node_ids = highest + 1; 4280} 4281#else 4282static inline void setup_nr_node_ids(void) 4283{ 4284} 4285#endif 4286 4287/** 4288 * node_map_pfn_alignment - determine the maximum internode alignment 4289 * 4290 * This function should be called after node map is populated and sorted. 4291 * It calculates the maximum power of two alignment which can distinguish 4292 * all the nodes. 4293 * 4294 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value 4295 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the 4296 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is 4297 * shifted, 1GiB is enough and this function will indicate so. 4298 * 4299 * This is used to test whether pfn -> nid mapping of the chosen memory 4300 * model has fine enough granularity to avoid incorrect mapping for the 4301 * populated node map. 4302 * 4303 * Returns the determined alignment in pfn's. 0 if there is no alignment 4304 * requirement (single node). 4305 */ 4306unsigned long __init node_map_pfn_alignment(void) 4307{ 4308 unsigned long accl_mask = 0, last_end = 0; 4309 unsigned long start, end, mask; 4310 int last_nid = -1; 4311 int i, nid; 4312 4313 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) { 4314 if (!start || last_nid < 0 || last_nid == nid) { 4315 last_nid = nid; 4316 last_end = end; 4317 continue; 4318 } 4319 4320 /* 4321 * Start with a mask granular enough to pin-point to the 4322 * start pfn and tick off bits one-by-one until it becomes 4323 * too coarse to separate the current node from the last. 4324 */ 4325 mask = ~((1 << __ffs(start)) - 1); 4326 while (mask && last_end <= (start & (mask << 1))) 4327 mask <<= 1; 4328 4329 /* accumulate all internode masks */ 4330 accl_mask |= mask; 4331 } 4332 4333 /* convert mask to number of pages */ 4334 return ~accl_mask + 1; 4335} 4336 4337/* Find the lowest pfn for a node */ 4338static unsigned long __init find_min_pfn_for_node(int nid) 4339{ 4340 unsigned long min_pfn = ULONG_MAX; 4341 unsigned long start_pfn; 4342 int i; 4343 4344 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL) 4345 min_pfn = min(min_pfn, start_pfn); 4346 4347 if (min_pfn == ULONG_MAX) { 4348 printk(KERN_WARNING 4349 "Could not find start_pfn for node %d\n", nid); 4350 return 0; 4351 } 4352 4353 return min_pfn; 4354} 4355 4356/** 4357 * find_min_pfn_with_active_regions - Find the minimum PFN registered 4358 * 4359 * It returns the minimum PFN based on information provided via 4360 * add_active_range(). 4361 */ 4362unsigned long __init find_min_pfn_with_active_regions(void) 4363{ 4364 return find_min_pfn_for_node(MAX_NUMNODES); 4365} 4366 4367/* 4368 * early_calculate_totalpages() 4369 * Sum pages in active regions for movable zone. 4370 * Populate N_HIGH_MEMORY for calculating usable_nodes. 4371 */ 4372static unsigned long __init early_calculate_totalpages(void) 4373{ 4374 unsigned long totalpages = 0; 4375 unsigned long start_pfn, end_pfn; 4376 int i, nid; 4377 4378 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { 4379 unsigned long pages = end_pfn - start_pfn; 4380 4381 totalpages += pages; 4382 if (pages) 4383 node_set_state(nid, N_HIGH_MEMORY); 4384 } 4385 return totalpages; 4386} 4387 4388/* 4389 * Find the PFN the Movable zone begins in each node. Kernel memory 4390 * is spread evenly between nodes as long as the nodes have enough 4391 * memory. When they don't, some nodes will have more kernelcore than 4392 * others 4393 */ 4394static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn) 4395{ 4396 int i, nid; 4397 unsigned long usable_startpfn; 4398 unsigned long kernelcore_node, kernelcore_remaining; 4399 /* save the state before borrow the nodemask */ 4400 nodemask_t saved_node_state = node_states[N_HIGH_MEMORY]; 4401 unsigned long totalpages = early_calculate_totalpages(); 4402 int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]); 4403 4404 /* 4405 * If movablecore was specified, calculate what size of 4406 * kernelcore that corresponds so that memory usable for 4407 * any allocation type is evenly spread. If both kernelcore 4408 * and movablecore are specified, then the value of kernelcore 4409 * will be used for required_kernelcore if it's greater than 4410 * what movablecore would have allowed. 4411 */ 4412 if (required_movablecore) { 4413 unsigned long corepages; 4414 4415 /* 4416 * Round-up so that ZONE_MOVABLE is at least as large as what 4417 * was requested by the user 4418 */ 4419 required_movablecore = 4420 roundup(required_movablecore, MAX_ORDER_NR_PAGES); 4421 corepages = totalpages - required_movablecore; 4422 4423 required_kernelcore = max(required_kernelcore, corepages); 4424 } 4425 4426 /* If kernelcore was not specified, there is no ZONE_MOVABLE */ 4427 if (!required_kernelcore) 4428 goto out; 4429 4430 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ 4431 find_usable_zone_for_movable(); 4432 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; 4433 4434restart: 4435 /* Spread kernelcore memory as evenly as possible throughout nodes */ 4436 kernelcore_node = required_kernelcore / usable_nodes; 4437 for_each_node_state(nid, N_HIGH_MEMORY) { 4438 unsigned long start_pfn, end_pfn; 4439 4440 /* 4441 * Recalculate kernelcore_node if the division per node 4442 * now exceeds what is necessary to satisfy the requested 4443 * amount of memory for the kernel 4444 */ 4445 if (required_kernelcore < kernelcore_node) 4446 kernelcore_node = required_kernelcore / usable_nodes; 4447 4448 /* 4449 * As the map is walked, we track how much memory is usable 4450 * by the kernel using kernelcore_remaining. When it is 4451 * 0, the rest of the node is usable by ZONE_MOVABLE 4452 */ 4453 kernelcore_remaining = kernelcore_node; 4454 4455 /* Go through each range of PFNs within this node */ 4456 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { 4457 unsigned long size_pages; 4458 4459 start_pfn = max(start_pfn, zone_movable_pfn[nid]); 4460 if (start_pfn >= end_pfn) 4461 continue; 4462 4463 /* Account for what is only usable for kernelcore */ 4464 if (start_pfn < usable_startpfn) { 4465 unsigned long kernel_pages; 4466 kernel_pages = min(end_pfn, usable_startpfn) 4467 - start_pfn; 4468 4469 kernelcore_remaining -= min(kernel_pages, 4470 kernelcore_remaining); 4471 required_kernelcore -= min(kernel_pages, 4472 required_kernelcore); 4473 4474 /* Continue if range is now fully accounted */ 4475 if (end_pfn <= usable_startpfn) { 4476 4477 /* 4478 * Push zone_movable_pfn to the end so 4479 * that if we have to rebalance 4480 * kernelcore across nodes, we will 4481 * not double account here 4482 */ 4483 zone_movable_pfn[nid] = end_pfn; 4484 continue; 4485 } 4486 start_pfn = usable_startpfn; 4487 } 4488 4489 /* 4490 * The usable PFN range for ZONE_MOVABLE is from 4491 * start_pfn->end_pfn. Calculate size_pages as the 4492 * number of pages used as kernelcore 4493 */ 4494 size_pages = end_pfn - start_pfn; 4495 if (size_pages > kernelcore_remaining) 4496 size_pages = kernelcore_remaining; 4497 zone_movable_pfn[nid] = start_pfn + size_pages; 4498 4499 /* 4500 * Some kernelcore has been met, update counts and 4501 * break if the kernelcore for this node has been 4502 * satisified 4503 */ 4504 required_kernelcore -= min(required_kernelcore, 4505 size_pages); 4506 kernelcore_remaining -= size_pages; 4507 if (!kernelcore_remaining) 4508 break; 4509 } 4510 } 4511 4512 /* 4513 * If there is still required_kernelcore, we do another pass with one 4514 * less node in the count. This will push zone_movable_pfn[nid] further 4515 * along on the nodes that still have memory until kernelcore is 4516 * satisified 4517 */ 4518 usable_nodes--; 4519 if (usable_nodes && required_kernelcore > usable_nodes) 4520 goto restart; 4521 4522 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ 4523 for (nid = 0; nid < MAX_NUMNODES; nid++) 4524 zone_movable_pfn[nid] = 4525 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); 4526 4527out: 4528 /* restore the node_state */ 4529 node_states[N_HIGH_MEMORY] = saved_node_state; 4530} 4531 4532/* Any regular memory on that node ? */ 4533static void check_for_regular_memory(pg_data_t *pgdat) 4534{ 4535#ifdef CONFIG_HIGHMEM 4536 enum zone_type zone_type; 4537 4538 for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) { 4539 struct zone *zone = &pgdat->node_zones[zone_type]; 4540 if (zone->present_pages) 4541 node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY); 4542 } 4543#endif 4544} 4545 4546/** 4547 * free_area_init_nodes - Initialise all pg_data_t and zone data 4548 * @max_zone_pfn: an array of max PFNs for each zone 4549 * 4550 * This will call free_area_init_node() for each active node in the system. 4551 * Using the page ranges provided by add_active_range(), the size of each 4552 * zone in each node and their holes is calculated. If the maximum PFN 4553 * between two adjacent zones match, it is assumed that the zone is empty. 4554 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed 4555 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone 4556 * starts where the previous one ended. For example, ZONE_DMA32 starts 4557 * at arch_max_dma_pfn. 4558 */ 4559void __init free_area_init_nodes(unsigned long *max_zone_pfn) 4560{ 4561 unsigned long start_pfn, end_pfn; 4562 int i, nid; 4563 4564 /* Record where the zone boundaries are */ 4565 memset(arch_zone_lowest_possible_pfn, 0, 4566 sizeof(arch_zone_lowest_possible_pfn)); 4567 memset(arch_zone_highest_possible_pfn, 0, 4568 sizeof(arch_zone_highest_possible_pfn)); 4569 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); 4570 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; 4571 for (i = 1; i < MAX_NR_ZONES; i++) { 4572 if (i == ZONE_MOVABLE) 4573 continue; 4574 arch_zone_lowest_possible_pfn[i] = 4575 arch_zone_highest_possible_pfn[i-1]; 4576 arch_zone_highest_possible_pfn[i] = 4577 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); 4578 } 4579 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0; 4580 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0; 4581 4582 /* Find the PFNs that ZONE_MOVABLE begins at in each node */ 4583 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); 4584 find_zone_movable_pfns_for_nodes(zone_movable_pfn); 4585 4586 /* Print out the zone ranges */ 4587 printk("Zone PFN ranges:\n"); 4588 for (i = 0; i < MAX_NR_ZONES; i++) { 4589 if (i == ZONE_MOVABLE) 4590 continue; 4591 printk(" %-8s ", zone_names[i]); 4592 if (arch_zone_lowest_possible_pfn[i] == 4593 arch_zone_highest_possible_pfn[i]) 4594 printk("empty\n"); 4595 else 4596 printk("%0#10lx -> %0#10lx\n", 4597 arch_zone_lowest_possible_pfn[i], 4598 arch_zone_highest_possible_pfn[i]); 4599 } 4600 4601 /* Print out the PFNs ZONE_MOVABLE begins at in each node */ 4602 printk("Movable zone start PFN for each node\n"); 4603 for (i = 0; i < MAX_NUMNODES; i++) { 4604 if (zone_movable_pfn[i]) 4605 printk(" Node %d: %lu\n", i, zone_movable_pfn[i]); 4606 } 4607 4608 /* Print out the early_node_map[] */ 4609 printk("Early memory PFN ranges\n"); 4610 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) 4611 printk(" %3d: %0#10lx -> %0#10lx\n", nid, start_pfn, end_pfn); 4612 4613 /* Initialise every node */ 4614 mminit_verify_pageflags_layout(); 4615 setup_nr_node_ids(); 4616 for_each_online_node(nid) { 4617 pg_data_t *pgdat = NODE_DATA(nid); 4618 free_area_init_node(nid, NULL, 4619 find_min_pfn_for_node(nid), NULL); 4620 4621 /* Any memory on that node */ 4622 if (pgdat->node_present_pages) 4623 node_set_state(nid, N_HIGH_MEMORY); 4624 check_for_regular_memory(pgdat); 4625 } 4626} 4627 4628static int __init cmdline_parse_core(char *p, unsigned long *core) 4629{ 4630 unsigned long long coremem; 4631 if (!p) 4632 return -EINVAL; 4633 4634 coremem = memparse(p, &p); 4635 *core = coremem >> PAGE_SHIFT; 4636 4637 /* Paranoid check that UL is enough for the coremem value */ 4638 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); 4639 4640 return 0; 4641} 4642 4643/* 4644 * kernelcore=size sets the amount of memory for use for allocations that 4645 * cannot be reclaimed or migrated. 4646 */ 4647static int __init cmdline_parse_kernelcore(char *p) 4648{ 4649 return cmdline_parse_core(p, &required_kernelcore); 4650} 4651 4652/* 4653 * movablecore=size sets the amount of memory for use for allocations that 4654 * can be reclaimed or migrated. 4655 */ 4656static int __init cmdline_parse_movablecore(char *p) 4657{ 4658 return cmdline_parse_core(p, &required_movablecore); 4659} 4660 4661early_param("kernelcore", cmdline_parse_kernelcore); 4662early_param("movablecore", cmdline_parse_movablecore); 4663 4664#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 4665 4666/** 4667 * set_dma_reserve - set the specified number of pages reserved in the first zone 4668 * @new_dma_reserve: The number of pages to mark reserved 4669 * 4670 * The per-cpu batchsize and zone watermarks are determined by present_pages. 4671 * In the DMA zone, a significant percentage may be consumed by kernel image 4672 * and other unfreeable allocations which can skew the watermarks badly. This 4673 * function may optionally be used to account for unfreeable pages in the 4674 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and 4675 * smaller per-cpu batchsize. 4676 */ 4677void __init set_dma_reserve(unsigned long new_dma_reserve) 4678{ 4679 dma_reserve = new_dma_reserve; 4680} 4681 4682void __init free_area_init(unsigned long *zones_size) 4683{ 4684 free_area_init_node(0, zones_size, 4685 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 4686} 4687 4688static int page_alloc_cpu_notify(struct notifier_block *self, 4689 unsigned long action, void *hcpu) 4690{ 4691 int cpu = (unsigned long)hcpu; 4692 4693 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { 4694 drain_pages(cpu); 4695 4696 /* 4697 * Spill the event counters of the dead processor 4698 * into the current processors event counters. 4699 * This artificially elevates the count of the current 4700 * processor. 4701 */ 4702 vm_events_fold_cpu(cpu); 4703 4704 /* 4705 * Zero the differential counters of the dead processor 4706 * so that the vm statistics are consistent. 4707 * 4708 * This is only okay since the processor is dead and cannot 4709 * race with what we are doing. 4710 */ 4711 refresh_cpu_vm_stats(cpu); 4712 } 4713 return NOTIFY_OK; 4714} 4715 4716void __init page_alloc_init(void) 4717{ 4718 hotcpu_notifier(page_alloc_cpu_notify, 0); 4719} 4720 4721/* 4722 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio 4723 * or min_free_kbytes changes. 4724 */ 4725static void calculate_totalreserve_pages(void) 4726{ 4727 struct pglist_data *pgdat; 4728 unsigned long reserve_pages = 0; 4729 enum zone_type i, j; 4730 4731 for_each_online_pgdat(pgdat) { 4732 for (i = 0; i < MAX_NR_ZONES; i++) { 4733 struct zone *zone = pgdat->node_zones + i; 4734 unsigned long max = 0; 4735 4736 /* Find valid and maximum lowmem_reserve in the zone */ 4737 for (j = i; j < MAX_NR_ZONES; j++) { 4738 if (zone->lowmem_reserve[j] > max) 4739 max = zone->lowmem_reserve[j]; 4740 } 4741 4742 /* we treat the high watermark as reserved pages. */ 4743 max += high_wmark_pages(zone); 4744 4745 if (max > zone->present_pages) 4746 max = zone->present_pages; 4747 reserve_pages += max; 4748 } 4749 } 4750 totalreserve_pages = reserve_pages; 4751} 4752 4753/* 4754 * setup_per_zone_lowmem_reserve - called whenever 4755 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 4756 * has a correct pages reserved value, so an adequate number of 4757 * pages are left in the zone after a successful __alloc_pages(). 4758 */ 4759static void setup_per_zone_lowmem_reserve(void) 4760{ 4761 struct pglist_data *pgdat; 4762 enum zone_type j, idx; 4763 4764 for_each_online_pgdat(pgdat) { 4765 for (j = 0; j < MAX_NR_ZONES; j++) { 4766 struct zone *zone = pgdat->node_zones + j; 4767 unsigned long present_pages = zone->present_pages; 4768 4769 zone->lowmem_reserve[j] = 0; 4770 4771 idx = j; 4772 while (idx) { 4773 struct zone *lower_zone; 4774 4775 idx--; 4776 4777 if (sysctl_lowmem_reserve_ratio[idx] < 1) 4778 sysctl_lowmem_reserve_ratio[idx] = 1; 4779 4780 lower_zone = pgdat->node_zones + idx; 4781 lower_zone->lowmem_reserve[j] = present_pages / 4782 sysctl_lowmem_reserve_ratio[idx]; 4783 present_pages += lower_zone->present_pages; 4784 } 4785 } 4786 } 4787 4788 /* update totalreserve_pages */ 4789 calculate_totalreserve_pages(); 4790} 4791 4792/** 4793 * setup_per_zone_wmarks - called when min_free_kbytes changes 4794 * or when memory is hot-{added|removed} 4795 * 4796 * Ensures that the watermark[min,low,high] values for each zone are set 4797 * correctly with respect to min_free_kbytes. 4798 */ 4799void setup_per_zone_wmarks(void) 4800{ 4801 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 4802 unsigned long lowmem_pages = 0; 4803 struct zone *zone; 4804 unsigned long flags; 4805 4806 /* Calculate total number of !ZONE_HIGHMEM pages */ 4807 for_each_zone(zone) { 4808 if (!is_highmem(zone)) 4809 lowmem_pages += zone->present_pages; 4810 } 4811 4812 for_each_zone(zone) { 4813 u64 tmp; 4814 4815 spin_lock_irqsave(&zone->lock, flags); 4816 tmp = (u64)pages_min * zone->present_pages; 4817 do_div(tmp, lowmem_pages); 4818 if (is_highmem(zone)) { 4819 /* 4820 * __GFP_HIGH and PF_MEMALLOC allocations usually don't 4821 * need highmem pages, so cap pages_min to a small 4822 * value here. 4823 * 4824 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN) 4825 * deltas controls asynch page reclaim, and so should 4826 * not be capped for highmem. 4827 */ 4828 int min_pages; 4829 4830 min_pages = zone->present_pages / 1024; 4831 if (min_pages < SWAP_CLUSTER_MAX) 4832 min_pages = SWAP_CLUSTER_MAX; 4833 if (min_pages > 128) 4834 min_pages = 128; 4835 zone->watermark[WMARK_MIN] = min_pages; 4836 } else { 4837 /* 4838 * If it's a lowmem zone, reserve a number of pages 4839 * proportionate to the zone's size. 4840 */ 4841 zone->watermark[WMARK_MIN] = tmp; 4842 } 4843 4844 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2); 4845 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1); 4846 setup_zone_migrate_reserve(zone); 4847 spin_unlock_irqrestore(&zone->lock, flags); 4848 } 4849 4850 /* update totalreserve_pages */ 4851 calculate_totalreserve_pages(); 4852} 4853 4854/* 4855 * The inactive anon list should be small enough that the VM never has to 4856 * do too much work, but large enough that each inactive page has a chance 4857 * to be referenced again before it is swapped out. 4858 * 4859 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to 4860 * INACTIVE_ANON pages on this zone's LRU, maintained by the 4861 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of 4862 * the anonymous pages are kept on the inactive list. 4863 * 4864 * total target max 4865 * memory ratio inactive anon 4866 * ------------------------------------- 4867 * 10MB 1 5MB 4868 * 100MB 1 50MB 4869 * 1GB 3 250MB 4870 * 10GB 10 0.9GB 4871 * 100GB 31 3GB 4872 * 1TB 101 10GB 4873 * 10TB 320 32GB 4874 */ 4875static void __meminit calculate_zone_inactive_ratio(struct zone *zone) 4876{ 4877 unsigned int gb, ratio; 4878 4879 /* Zone size in gigabytes */ 4880 gb = zone->present_pages >> (30 - PAGE_SHIFT); 4881 if (gb) 4882 ratio = int_sqrt(10 * gb); 4883 else 4884 ratio = 1; 4885 4886 zone->inactive_ratio = ratio; 4887} 4888 4889static void __meminit setup_per_zone_inactive_ratio(void) 4890{ 4891 struct zone *zone; 4892 4893 for_each_zone(zone) 4894 calculate_zone_inactive_ratio(zone); 4895} 4896 4897/* 4898 * Initialise min_free_kbytes. 4899 * 4900 * For small machines we want it small (128k min). For large machines 4901 * we want it large (64MB max). But it is not linear, because network 4902 * bandwidth does not increase linearly with machine size. We use 4903 * 4904 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 4905 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 4906 * 4907 * which yields 4908 * 4909 * 16MB: 512k 4910 * 32MB: 724k 4911 * 64MB: 1024k 4912 * 128MB: 1448k 4913 * 256MB: 2048k 4914 * 512MB: 2896k 4915 * 1024MB: 4096k 4916 * 2048MB: 5792k 4917 * 4096MB: 8192k 4918 * 8192MB: 11584k 4919 * 16384MB: 16384k 4920 */ 4921int __meminit init_per_zone_wmark_min(void) 4922{ 4923 unsigned long lowmem_kbytes; 4924 4925 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 4926 4927 min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 4928 if (min_free_kbytes < 128) 4929 min_free_kbytes = 128; 4930 if (min_free_kbytes > 65536) 4931 min_free_kbytes = 65536; 4932 setup_per_zone_wmarks(); 4933 refresh_zone_stat_thresholds(); 4934 setup_per_zone_lowmem_reserve(); 4935 setup_per_zone_inactive_ratio(); 4936 return 0; 4937} 4938module_init(init_per_zone_wmark_min) 4939 4940/* 4941 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 4942 * that we can call two helper functions whenever min_free_kbytes 4943 * changes. 4944 */ 4945int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 4946 void __user *buffer, size_t *length, loff_t *ppos) 4947{ 4948 proc_dointvec(table, write, buffer, length, ppos); 4949 if (write) 4950 setup_per_zone_wmarks(); 4951 return 0; 4952} 4953 4954#ifdef CONFIG_NUMA 4955int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, 4956 void __user *buffer, size_t *length, loff_t *ppos) 4957{ 4958 struct zone *zone; 4959 int rc; 4960 4961 rc = proc_dointvec_minmax(table, write, buffer, length, ppos); 4962 if (rc) 4963 return rc; 4964 4965 for_each_zone(zone) 4966 zone->min_unmapped_pages = (zone->present_pages * 4967 sysctl_min_unmapped_ratio) / 100; 4968 return 0; 4969} 4970 4971int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write, 4972 void __user *buffer, size_t *length, loff_t *ppos) 4973{ 4974 struct zone *zone; 4975 int rc; 4976 4977 rc = proc_dointvec_minmax(table, write, buffer, length, ppos); 4978 if (rc) 4979 return rc; 4980 4981 for_each_zone(zone) 4982 zone->min_slab_pages = (zone->present_pages * 4983 sysctl_min_slab_ratio) / 100; 4984 return 0; 4985} 4986#endif 4987 4988/* 4989 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 4990 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 4991 * whenever sysctl_lowmem_reserve_ratio changes. 4992 * 4993 * The reserve ratio obviously has absolutely no relation with the 4994 * minimum watermarks. The lowmem reserve ratio can only make sense 4995 * if in function of the boot time zone sizes. 4996 */ 4997int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, 4998 void __user *buffer, size_t *length, loff_t *ppos) 4999{ 5000 proc_dointvec_minmax(table, write, buffer, length, ppos); 5001 setup_per_zone_lowmem_reserve(); 5002 return 0; 5003} 5004 5005/* 5006 * percpu_pagelist_fraction - changes the pcp->high for each zone on each 5007 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist 5008 * can have before it gets flushed back to buddy allocator. 5009 */ 5010 5011int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, 5012 void __user *buffer, size_t *length, loff_t *ppos) 5013{ 5014 struct zone *zone; 5015 unsigned int cpu; 5016 int ret; 5017 5018 ret = proc_dointvec_minmax(table, write, buffer, length, ppos); 5019 if (!write || (ret == -EINVAL)) 5020 return ret; 5021 for_each_populated_zone(zone) { 5022 for_each_possible_cpu(cpu) { 5023 unsigned long high; 5024 high = zone->present_pages / percpu_pagelist_fraction; 5025 setup_pagelist_highmark( 5026 per_cpu_ptr(zone->pageset, cpu), high); 5027 } 5028 } 5029 return 0; 5030} 5031 5032int hashdist = HASHDIST_DEFAULT; 5033 5034#ifdef CONFIG_NUMA 5035static int __init set_hashdist(char *str) 5036{ 5037 if (!str) 5038 return 0; 5039 hashdist = simple_strtoul(str, &str, 0); 5040 return 1; 5041} 5042__setup("hashdist=", set_hashdist); 5043#endif 5044 5045/* 5046 * allocate a large system hash table from bootmem 5047 * - it is assumed that the hash table must contain an exact power-of-2 5048 * quantity of entries 5049 * - limit is the number of hash buckets, not the total allocation size 5050 */ 5051void *__init alloc_large_system_hash(const char *tablename, 5052 unsigned long bucketsize, 5053 unsigned long numentries, 5054 int scale, 5055 int flags, 5056 unsigned int *_hash_shift, 5057 unsigned int *_hash_mask, 5058 unsigned long limit) 5059{ 5060 unsigned long long max = limit; 5061 unsigned long log2qty, size; 5062 void *table = NULL; 5063 5064 /* allow the kernel cmdline to have a say */ 5065 if (!numentries) { 5066 /* round applicable memory size up to nearest megabyte */ 5067 numentries = nr_kernel_pages; 5068 numentries += (1UL << (20 - PAGE_SHIFT)) - 1; 5069 numentries >>= 20 - PAGE_SHIFT; 5070 numentries <<= 20 - PAGE_SHIFT; 5071 5072 /* limit to 1 bucket per 2^scale bytes of low memory */ 5073 if (scale > PAGE_SHIFT) 5074 numentries >>= (scale - PAGE_SHIFT); 5075 else 5076 numentries <<= (PAGE_SHIFT - scale); 5077 5078 /* Make sure we've got at least a 0-order allocation.. */ 5079 if (unlikely(flags & HASH_SMALL)) { 5080 /* Makes no sense without HASH_EARLY */ 5081 WARN_ON(!(flags & HASH_EARLY)); 5082 if (!(numentries >> *_hash_shift)) { 5083 numentries = 1UL << *_hash_shift; 5084 BUG_ON(!numentries); 5085 } 5086 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE)) 5087 numentries = PAGE_SIZE / bucketsize; 5088 } 5089 numentries = roundup_pow_of_two(numentries); 5090 5091 /* limit allocation size to 1/16 total memory by default */ 5092 if (max == 0) { 5093 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 5094 do_div(max, bucketsize); 5095 } 5096 5097 if (numentries > max) 5098 numentries = max; 5099 5100 log2qty = ilog2(numentries); 5101 5102 do { 5103 size = bucketsize << log2qty; 5104 if (flags & HASH_EARLY) 5105 table = alloc_bootmem_nopanic(size); 5106 else if (hashdist) 5107 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 5108 else { 5109 /* 5110 * If bucketsize is not a power-of-two, we may free 5111 * some pages at the end of hash table which 5112 * alloc_pages_exact() automatically does 5113 */ 5114 if (get_order(size) < MAX_ORDER) { 5115 table = alloc_pages_exact(size, GFP_ATOMIC); 5116 kmemleak_alloc(table, size, 1, GFP_ATOMIC); 5117 } 5118 } 5119 } while (!table && size > PAGE_SIZE && --log2qty); 5120 5121 if (!table) 5122 panic("Failed to allocate %s hash table\n", tablename); 5123 5124 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n", 5125 tablename, 5126 (1UL << log2qty), 5127 ilog2(size) - PAGE_SHIFT, 5128 size); 5129 5130 if (_hash_shift) 5131 *_hash_shift = log2qty; 5132 if (_hash_mask) 5133 *_hash_mask = (1 << log2qty) - 1; 5134 5135 return table; 5136} 5137 5138/* Return a pointer to the bitmap storing bits affecting a block of pages */ 5139static inline unsigned long *get_pageblock_bitmap(struct zone *zone, 5140 unsigned long pfn) 5141{ 5142#ifdef CONFIG_SPARSEMEM 5143 return __pfn_to_section(pfn)->pageblock_flags; 5144#else 5145 return zone->pageblock_flags; 5146#endif /* CONFIG_SPARSEMEM */ 5147} 5148 5149static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) 5150{ 5151#ifdef CONFIG_SPARSEMEM 5152 pfn &= (PAGES_PER_SECTION-1); 5153 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 5154#else 5155 pfn = pfn - zone->zone_start_pfn; 5156 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 5157#endif /* CONFIG_SPARSEMEM */ 5158} 5159 5160/** 5161 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages 5162 * @page: The page within the block of interest 5163 * @start_bitidx: The first bit of interest to retrieve 5164 * @end_bitidx: The last bit of interest 5165 * returns pageblock_bits flags 5166 */ 5167unsigned long get_pageblock_flags_group(struct page *page, 5168 int start_bitidx, int end_bitidx) 5169{ 5170 struct zone *zone; 5171 unsigned long *bitmap; 5172 unsigned long pfn, bitidx; 5173 unsigned long flags = 0; 5174 unsigned long value = 1; 5175 5176 zone = page_zone(page); 5177 pfn = page_to_pfn(page); 5178 bitmap = get_pageblock_bitmap(zone, pfn); 5179 bitidx = pfn_to_bitidx(zone, pfn); 5180 5181 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 5182 if (test_bit(bitidx + start_bitidx, bitmap)) 5183 flags |= value; 5184 5185 return flags; 5186} 5187 5188/** 5189 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages 5190 * @page: The page within the block of interest 5191 * @start_bitidx: The first bit of interest 5192 * @end_bitidx: The last bit of interest 5193 * @flags: The flags to set 5194 */ 5195void set_pageblock_flags_group(struct page *page, unsigned long flags, 5196 int start_bitidx, int end_bitidx) 5197{ 5198 struct zone *zone; 5199 unsigned long *bitmap; 5200 unsigned long pfn, bitidx; 5201 unsigned long value = 1; 5202 5203 zone = page_zone(page); 5204 pfn = page_to_pfn(page); 5205 bitmap = get_pageblock_bitmap(zone, pfn); 5206 bitidx = pfn_to_bitidx(zone, pfn); 5207 VM_BUG_ON(pfn < zone->zone_start_pfn); 5208 VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages); 5209 5210 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 5211 if (flags & value) 5212 __set_bit(bitidx + start_bitidx, bitmap); 5213 else 5214 __clear_bit(bitidx + start_bitidx, bitmap); 5215} 5216 5217/* 5218 * This is designed as sub function...plz see page_isolation.c also. 5219 * set/clear page block's type to be ISOLATE. 5220 * page allocater never alloc memory from ISOLATE block. 5221 */ 5222 5223static int 5224__count_immobile_pages(struct zone *zone, struct page *page, int count) 5225{ 5226 unsigned long pfn, iter, found; 5227 /* 5228 * For avoiding noise data, lru_add_drain_all() should be called 5229 * If ZONE_MOVABLE, the zone never contains immobile pages 5230 */ 5231 if (zone_idx(zone) == ZONE_MOVABLE) 5232 return true; 5233 5234 if (get_pageblock_migratetype(page) == MIGRATE_MOVABLE) 5235 return true; 5236 5237 pfn = page_to_pfn(page); 5238 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) { 5239 unsigned long check = pfn + iter; 5240 5241 if (!pfn_valid_within(check)) 5242 continue; 5243 5244 page = pfn_to_page(check); 5245 if (!page_count(page)) { 5246 if (PageBuddy(page)) 5247 iter += (1 << page_order(page)) - 1; 5248 continue; 5249 } 5250 if (!PageLRU(page)) 5251 found++; 5252 /* 5253 * If there are RECLAIMABLE pages, we need to check it. 5254 * But now, memory offline itself doesn't call shrink_slab() 5255 * and it still to be fixed. 5256 */ 5257 /* 5258 * If the page is not RAM, page_count()should be 0. 5259 * we don't need more check. This is an _used_ not-movable page. 5260 * 5261 * The problematic thing here is PG_reserved pages. PG_reserved 5262 * is set to both of a memory hole page and a _used_ kernel 5263 * page at boot. 5264 */ 5265 if (found > count) 5266 return false; 5267 } 5268 return true; 5269} 5270 5271bool is_pageblock_removable_nolock(struct page *page) 5272{ 5273 struct zone *zone = page_zone(page); 5274 return __count_immobile_pages(zone, page, 0); 5275} 5276 5277int set_migratetype_isolate(struct page *page) 5278{ 5279 struct zone *zone; 5280 unsigned long flags, pfn; 5281 struct memory_isolate_notify arg; 5282 int notifier_ret; 5283 int ret = -EBUSY; 5284 5285 zone = page_zone(page); 5286 5287 spin_lock_irqsave(&zone->lock, flags); 5288 5289 pfn = page_to_pfn(page); 5290 arg.start_pfn = pfn; 5291 arg.nr_pages = pageblock_nr_pages; 5292 arg.pages_found = 0; 5293 5294 /* 5295 * It may be possible to isolate a pageblock even if the 5296 * migratetype is not MIGRATE_MOVABLE. The memory isolation 5297 * notifier chain is used by balloon drivers to return the 5298 * number of pages in a range that are held by the balloon 5299 * driver to shrink memory. If all the pages are accounted for 5300 * by balloons, are free, or on the LRU, isolation can continue. 5301 * Later, for example, when memory hotplug notifier runs, these 5302 * pages reported as "can be isolated" should be isolated(freed) 5303 * by the balloon driver through the memory notifier chain. 5304 */ 5305 notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg); 5306 notifier_ret = notifier_to_errno(notifier_ret); 5307 if (notifier_ret) 5308 goto out; 5309 /* 5310 * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself. 5311 * We just check MOVABLE pages. 5312 */ 5313 if (__count_immobile_pages(zone, page, arg.pages_found)) 5314 ret = 0; 5315 5316 /* 5317 * immobile means "not-on-lru" paes. If immobile is larger than 5318 * removable-by-driver pages reported by notifier, we'll fail. 5319 */ 5320 5321out: 5322 if (!ret) { 5323 set_pageblock_migratetype(page, MIGRATE_ISOLATE); 5324 move_freepages_block(zone, page, MIGRATE_ISOLATE); 5325 } 5326 5327 spin_unlock_irqrestore(&zone->lock, flags); 5328 if (!ret) 5329 drain_all_pages(); 5330 return ret; 5331} 5332 5333void unset_migratetype_isolate(struct page *page) 5334{ 5335 struct zone *zone; 5336 unsigned long flags; 5337 zone = page_zone(page); 5338 spin_lock_irqsave(&zone->lock, flags); 5339 if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE) 5340 goto out; 5341 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 5342 move_freepages_block(zone, page, MIGRATE_MOVABLE); 5343out: 5344 spin_unlock_irqrestore(&zone->lock, flags); 5345} 5346 5347#ifdef CONFIG_MEMORY_HOTREMOVE 5348/* 5349 * All pages in the range must be isolated before calling this. 5350 */ 5351void 5352__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) 5353{ 5354 struct page *page; 5355 struct zone *zone; 5356 int order, i; 5357 unsigned long pfn; 5358 unsigned long flags; 5359 /* find the first valid pfn */ 5360 for (pfn = start_pfn; pfn < end_pfn; pfn++) 5361 if (pfn_valid(pfn)) 5362 break; 5363 if (pfn == end_pfn) 5364 return; 5365 zone = page_zone(pfn_to_page(pfn)); 5366 spin_lock_irqsave(&zone->lock, flags); 5367 pfn = start_pfn; 5368 while (pfn < end_pfn) { 5369 if (!pfn_valid(pfn)) { 5370 pfn++; 5371 continue; 5372 } 5373 page = pfn_to_page(pfn); 5374 BUG_ON(page_count(page)); 5375 BUG_ON(!PageBuddy(page)); 5376 order = page_order(page); 5377#ifdef CONFIG_DEBUG_VM 5378 printk(KERN_INFO "remove from free list %lx %d %lx\n", 5379 pfn, 1 << order, end_pfn); 5380#endif 5381 list_del(&page->lru); 5382 rmv_page_order(page); 5383 zone->free_area[order].nr_free--; 5384 __mod_zone_page_state(zone, NR_FREE_PAGES, 5385 - (1UL << order)); 5386 for (i = 0; i < (1 << order); i++) 5387 SetPageReserved((page+i)); 5388 pfn += (1 << order); 5389 } 5390 spin_unlock_irqrestore(&zone->lock, flags); 5391} 5392#endif 5393 5394#ifdef CONFIG_MEMORY_FAILURE 5395bool is_free_buddy_page(struct page *page) 5396{ 5397 struct zone *zone = page_zone(page); 5398 unsigned long pfn = page_to_pfn(page); 5399 unsigned long flags; 5400 int order; 5401 5402 spin_lock_irqsave(&zone->lock, flags); 5403 for (order = 0; order < MAX_ORDER; order++) { 5404 struct page *page_head = page - (pfn & ((1 << order) - 1)); 5405 5406 if (PageBuddy(page_head) && page_order(page_head) >= order) 5407 break; 5408 } 5409 spin_unlock_irqrestore(&zone->lock, flags); 5410 5411 return order < MAX_ORDER; 5412} 5413#endif 5414 5415static struct trace_print_flags pageflag_names[] = { 5416 {1UL << PG_locked, "locked" }, 5417 {1UL << PG_error, "error" }, 5418 {1UL << PG_referenced, "referenced" }, 5419 {1UL << PG_uptodate, "uptodate" }, 5420 {1UL << PG_dirty, "dirty" }, 5421 {1UL << PG_lru, "lru" }, 5422 {1UL << PG_active, "active" }, 5423 {1UL << PG_slab, "slab" }, 5424 {1UL << PG_owner_priv_1, "owner_priv_1" }, 5425 {1UL << PG_arch_1, "arch_1" }, 5426 {1UL << PG_reserved, "reserved" }, 5427 {1UL << PG_private, "private" }, 5428 {1UL << PG_private_2, "private_2" }, 5429 {1UL << PG_writeback, "writeback" }, 5430#ifdef CONFIG_PAGEFLAGS_EXTENDED 5431 {1UL << PG_head, "head" }, 5432 {1UL << PG_tail, "tail" }, 5433#else 5434 {1UL << PG_compound, "compound" }, 5435#endif 5436 {1UL << PG_swapcache, "swapcache" }, 5437 {1UL << PG_mappedtodisk, "mappedtodisk" }, 5438 {1UL << PG_reclaim, "reclaim" }, 5439 {1UL << PG_swapbacked, "swapbacked" }, 5440 {1UL << PG_unevictable, "unevictable" }, 5441#ifdef CONFIG_MMU 5442 {1UL << PG_mlocked, "mlocked" }, 5443#endif 5444#ifdef CONFIG_ARCH_USES_PG_UNCACHED 5445 {1UL << PG_uncached, "uncached" }, 5446#endif 5447#ifdef CONFIG_MEMORY_FAILURE 5448 {1UL << PG_hwpoison, "hwpoison" }, 5449#endif 5450 {-1UL, NULL }, 5451}; 5452 5453static void dump_page_flags(unsigned long flags) 5454{ 5455 const char *delim = ""; 5456 unsigned long mask; 5457 int i; 5458 5459 printk(KERN_ALERT "page flags: %#lx(", flags); 5460 5461 /* remove zone id */ 5462 flags &= (1UL << NR_PAGEFLAGS) - 1; 5463 5464 for (i = 0; pageflag_names[i].name && flags; i++) { 5465 5466 mask = pageflag_names[i].mask; 5467 if ((flags & mask) != mask) 5468 continue; 5469 5470 flags &= ~mask; 5471 printk("%s%s", delim, pageflag_names[i].name); 5472 delim = "|"; 5473 } 5474 5475 /* check for left over flags */ 5476 if (flags) 5477 printk("%s%#lx", delim, flags); 5478 5479 printk(")\n"); 5480} 5481 5482void dump_page(struct page *page) 5483{ 5484 printk(KERN_ALERT 5485 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n", 5486 page, atomic_read(&page->_count), page_mapcount(page), 5487 page->mapping, page->index); 5488 dump_page_flags(page->flags); 5489 mem_cgroup_print_bad_page(page); 5490} 5491