1 /* 2 * linux/mm/page_alloc.c 3 * 4 * Manages the free list, the system allocates free pages here. 5 * Note that kmalloc() lives in slab.c 6 * 7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 8 * Swap reorganised 29.12.95, Stephen Tweedie 9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999 11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999 12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000 13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002 14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton) 15 */ 16 17 #include <linux/stddef.h> 18 #include <linux/mm.h> 19 #include <linux/swap.h> 20 #include <linux/interrupt.h> 21 #include <linux/pagemap.h> 22 #include <linux/bootmem.h> 23 #include <linux/compiler.h> 24 #include <linux/kernel.h> 25 #include <linux/module.h> 26 #include <linux/suspend.h> 27 #include <linux/pagevec.h> 28 #include <linux/blkdev.h> 29 #include <linux/slab.h> 30 #include <linux/notifier.h> 31 #include <linux/topology.h> 32 #include <linux/sysctl.h> 33 #include <linux/cpu.h> 34 #include <linux/cpuset.h> 35 #include <linux/memory_hotplug.h> 36 #include <linux/nodemask.h> 37 #include <linux/vmalloc.h> 38 #include <linux/mempolicy.h> 39 #include <linux/stop_machine.h> 40 #include <linux/sort.h> 41 #include <linux/pfn.h> 42 #include <linux/backing-dev.h> 43 #include <linux/fault-inject.h> 44 45 #include <asm/tlbflush.h> 46 #include <asm/div64.h> 47 #include "internal.h" 48 49 /* 50 * MCD - HACK: Find somewhere to initialize this EARLY, or make this 51 * initializer cleaner 52 */ 53 nodemask_t node_online_map __read_mostly = { { [0] = 1UL } }; 54 EXPORT_SYMBOL(node_online_map); 55 nodemask_t node_possible_map __read_mostly = NODE_MASK_ALL; 56 EXPORT_SYMBOL(node_possible_map); 57 unsigned long totalram_pages __read_mostly; 58 unsigned long totalreserve_pages __read_mostly; 59 long nr_swap_pages; 60 int percpu_pagelist_fraction; 61 62 static void __free_pages_ok(struct page *page, unsigned int order); 63 64 /* 65 * results with 256, 32 in the lowmem_reserve sysctl: 66 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) 67 * 1G machine -> (16M dma, 784M normal, 224M high) 68 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA 69 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL 70 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA 71 * 72 * TBD: should special case ZONE_DMA32 machines here - in those we normally 73 * don't need any ZONE_NORMAL reservation 74 */ 75 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 76 #ifdef CONFIG_ZONE_DMA 77 256, 78 #endif 79 #ifdef CONFIG_ZONE_DMA32 80 256, 81 #endif 82 #ifdef CONFIG_HIGHMEM 83 32 84 #endif 85 }; 86 87 EXPORT_SYMBOL(totalram_pages); 88 89 static char * const zone_names[MAX_NR_ZONES] = { 90 #ifdef CONFIG_ZONE_DMA 91 "DMA", 92 #endif 93 #ifdef CONFIG_ZONE_DMA32 94 "DMA32", 95 #endif 96 "Normal", 97 #ifdef CONFIG_HIGHMEM 98 "HighMem" 99 #endif 100 }; 101 102 int min_free_kbytes = 1024; 103 104 unsigned long __meminitdata nr_kernel_pages; 105 unsigned long __meminitdata nr_all_pages; 106 static unsigned long __meminitdata dma_reserve; 107 108 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP 109 /* 110 * MAX_ACTIVE_REGIONS determines the maxmimum number of distinct 111 * ranges of memory (RAM) that may be registered with add_active_range(). 112 * Ranges passed to add_active_range() will be merged if possible 113 * so the number of times add_active_range() can be called is 114 * related to the number of nodes and the number of holes 115 */ 116 #ifdef CONFIG_MAX_ACTIVE_REGIONS 117 /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */ 118 #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS 119 #else 120 #if MAX_NUMNODES >= 32 121 /* If there can be many nodes, allow up to 50 holes per node */ 122 #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50) 123 #else 124 /* By default, allow up to 256 distinct regions */ 125 #define MAX_ACTIVE_REGIONS 256 126 #endif 127 #endif 128 129 struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS]; 130 int __meminitdata nr_nodemap_entries; 131 unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; 132 unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; 133 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE 134 unsigned long __initdata node_boundary_start_pfn[MAX_NUMNODES]; 135 unsigned long __initdata node_boundary_end_pfn[MAX_NUMNODES]; 136 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */ 137 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 138 139 #ifdef CONFIG_DEBUG_VM 140 static int page_outside_zone_boundaries(struct zone *zone, struct page *page) 141 { 142 int ret = 0; 143 unsigned seq; 144 unsigned long pfn = page_to_pfn(page); 145 146 do { 147 seq = zone_span_seqbegin(zone); 148 if (pfn >= zone->zone_start_pfn + zone->spanned_pages) 149 ret = 1; 150 else if (pfn < zone->zone_start_pfn) 151 ret = 1; 152 } while (zone_span_seqretry(zone, seq)); 153 154 return ret; 155 } 156 157 static int page_is_consistent(struct zone *zone, struct page *page) 158 { 159 if (!pfn_valid_within(page_to_pfn(page))) 160 return 0; 161 if (zone != page_zone(page)) 162 return 0; 163 164 return 1; 165 } 166 /* 167 * Temporary debugging check for pages not lying within a given zone. 168 */ 169 static int bad_range(struct zone *zone, struct page *page) 170 { 171 if (page_outside_zone_boundaries(zone, page)) 172 return 1; 173 if (!page_is_consistent(zone, page)) 174 return 1; 175 176 return 0; 177 } 178 #else 179 static inline int bad_range(struct zone *zone, struct page *page) 180 { 181 return 0; 182 } 183 #endif 184 185 static void bad_page(struct page *page) 186 { 187 printk(KERN_EMERG "Bad page state in process '%s'\n" 188 KERN_EMERG "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n" 189 KERN_EMERG "Trying to fix it up, but a reboot is needed\n" 190 KERN_EMERG "Backtrace:\n", 191 current->comm, page, (int)(2*sizeof(unsigned long)), 192 (unsigned long)page->flags, page->mapping, 193 page_mapcount(page), page_count(page)); 194 dump_stack(); 195 page->flags &= ~(1 << PG_lru | 196 1 << PG_private | 197 1 << PG_locked | 198 1 << PG_active | 199 1 << PG_dirty | 200 1 << PG_reclaim | 201 1 << PG_slab | 202 1 << PG_swapcache | 203 1 << PG_writeback | 204 1 << PG_buddy ); 205 set_page_count(page, 0); 206 reset_page_mapcount(page); 207 page->mapping = NULL; 208 add_taint(TAINT_BAD_PAGE); 209 } 210 211 /* 212 * Higher-order pages are called "compound pages". They are structured thusly: 213 * 214 * The first PAGE_SIZE page is called the "head page". 215 * 216 * The remaining PAGE_SIZE pages are called "tail pages". 217 * 218 * All pages have PG_compound set. All pages have their ->private pointing at 219 * the head page (even the head page has this). 220 * 221 * The first tail page's ->lru.next holds the address of the compound page's 222 * put_page() function. Its ->lru.prev holds the order of allocation. 223 * This usage means that zero-order pages may not be compound. 224 */ 225 226 static void free_compound_page(struct page *page) 227 { 228 __free_pages_ok(page, compound_order(page)); 229 } 230 231 static void prep_compound_page(struct page *page, unsigned long order) 232 { 233 int i; 234 int nr_pages = 1 << order; 235 236 set_compound_page_dtor(page, free_compound_page); 237 set_compound_order(page, order); 238 __SetPageHead(page); 239 for (i = 1; i < nr_pages; i++) { 240 struct page *p = page + i; 241 242 __SetPageTail(p); 243 p->first_page = page; 244 } 245 } 246 247 static void destroy_compound_page(struct page *page, unsigned long order) 248 { 249 int i; 250 int nr_pages = 1 << order; 251 252 if (unlikely(compound_order(page) != order)) 253 bad_page(page); 254 255 if (unlikely(!PageHead(page))) 256 bad_page(page); 257 __ClearPageHead(page); 258 for (i = 1; i < nr_pages; i++) { 259 struct page *p = page + i; 260 261 if (unlikely(!PageTail(p) | 262 (p->first_page != page))) 263 bad_page(page); 264 __ClearPageTail(p); 265 } 266 } 267 268 static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) 269 { 270 int i; 271 272 VM_BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM); 273 /* 274 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO 275 * and __GFP_HIGHMEM from hard or soft interrupt context. 276 */ 277 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); 278 for (i = 0; i < (1 << order); i++) 279 clear_highpage(page + i); 280 } 281 282 /* 283 * function for dealing with page's order in buddy system. 284 * zone->lock is already acquired when we use these. 285 * So, we don't need atomic page->flags operations here. 286 */ 287 static inline unsigned long page_order(struct page *page) 288 { 289 return page_private(page); 290 } 291 292 static inline void set_page_order(struct page *page, int order) 293 { 294 set_page_private(page, order); 295 __SetPageBuddy(page); 296 } 297 298 static inline void rmv_page_order(struct page *page) 299 { 300 __ClearPageBuddy(page); 301 set_page_private(page, 0); 302 } 303 304 /* 305 * Locate the struct page for both the matching buddy in our 306 * pair (buddy1) and the combined O(n+1) page they form (page). 307 * 308 * 1) Any buddy B1 will have an order O twin B2 which satisfies 309 * the following equation: 310 * B2 = B1 ^ (1 << O) 311 * For example, if the starting buddy (buddy2) is #8 its order 312 * 1 buddy is #10: 313 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 314 * 315 * 2) Any buddy B will have an order O+1 parent P which 316 * satisfies the following equation: 317 * P = B & ~(1 << O) 318 * 319 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 320 */ 321 static inline struct page * 322 __page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order) 323 { 324 unsigned long buddy_idx = page_idx ^ (1 << order); 325 326 return page + (buddy_idx - page_idx); 327 } 328 329 static inline unsigned long 330 __find_combined_index(unsigned long page_idx, unsigned int order) 331 { 332 return (page_idx & ~(1 << order)); 333 } 334 335 /* 336 * This function checks whether a page is free && is the buddy 337 * we can do coalesce a page and its buddy if 338 * (a) the buddy is not in a hole && 339 * (b) the buddy is in the buddy system && 340 * (c) a page and its buddy have the same order && 341 * (d) a page and its buddy are in the same zone. 342 * 343 * For recording whether a page is in the buddy system, we use PG_buddy. 344 * Setting, clearing, and testing PG_buddy is serialized by zone->lock. 345 * 346 * For recording page's order, we use page_private(page). 347 */ 348 static inline int page_is_buddy(struct page *page, struct page *buddy, 349 int order) 350 { 351 if (!pfn_valid_within(page_to_pfn(buddy))) 352 return 0; 353 354 if (page_zone_id(page) != page_zone_id(buddy)) 355 return 0; 356 357 if (PageBuddy(buddy) && page_order(buddy) == order) { 358 BUG_ON(page_count(buddy) != 0); 359 return 1; 360 } 361 return 0; 362 } 363 364 /* 365 * Freeing function for a buddy system allocator. 366 * 367 * The concept of a buddy system is to maintain direct-mapped table 368 * (containing bit values) for memory blocks of various "orders". 369 * The bottom level table contains the map for the smallest allocatable 370 * units of memory (here, pages), and each level above it describes 371 * pairs of units from the levels below, hence, "buddies". 372 * At a high level, all that happens here is marking the table entry 373 * at the bottom level available, and propagating the changes upward 374 * as necessary, plus some accounting needed to play nicely with other 375 * parts of the VM system. 376 * At each level, we keep a list of pages, which are heads of continuous 377 * free pages of length of (1 << order) and marked with PG_buddy. Page's 378 * order is recorded in page_private(page) field. 379 * So when we are allocating or freeing one, we can derive the state of the 380 * other. That is, if we allocate a small block, and both were 381 * free, the remainder of the region must be split into blocks. 382 * If a block is freed, and its buddy is also free, then this 383 * triggers coalescing into a block of larger size. 384 * 385 * -- wli 386 */ 387 388 static inline void __free_one_page(struct page *page, 389 struct zone *zone, unsigned int order) 390 { 391 unsigned long page_idx; 392 int order_size = 1 << order; 393 394 if (unlikely(PageCompound(page))) 395 destroy_compound_page(page, order); 396 397 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); 398 399 VM_BUG_ON(page_idx & (order_size - 1)); 400 VM_BUG_ON(bad_range(zone, page)); 401 402 __mod_zone_page_state(zone, NR_FREE_PAGES, order_size); 403 while (order < MAX_ORDER-1) { 404 unsigned long combined_idx; 405 struct free_area *area; 406 struct page *buddy; 407 408 buddy = __page_find_buddy(page, page_idx, order); 409 if (!page_is_buddy(page, buddy, order)) 410 break; /* Move the buddy up one level. */ 411 412 list_del(&buddy->lru); 413 area = zone->free_area + order; 414 area->nr_free--; 415 rmv_page_order(buddy); 416 combined_idx = __find_combined_index(page_idx, order); 417 page = page + (combined_idx - page_idx); 418 page_idx = combined_idx; 419 order++; 420 } 421 set_page_order(page, order); 422 list_add(&page->lru, &zone->free_area[order].free_list); 423 zone->free_area[order].nr_free++; 424 } 425 426 static inline int free_pages_check(struct page *page) 427 { 428 if (unlikely(page_mapcount(page) | 429 (page->mapping != NULL) | 430 (page_count(page) != 0) | 431 (page->flags & ( 432 1 << PG_lru | 433 1 << PG_private | 434 1 << PG_locked | 435 1 << PG_active | 436 1 << PG_slab | 437 1 << PG_swapcache | 438 1 << PG_writeback | 439 1 << PG_reserved | 440 1 << PG_buddy )))) 441 bad_page(page); 442 /* 443 * PageReclaim == PageTail. It is only an error 444 * for PageReclaim to be set if PageCompound is clear. 445 */ 446 if (unlikely(!PageCompound(page) && PageReclaim(page))) 447 bad_page(page); 448 if (PageDirty(page)) 449 __ClearPageDirty(page); 450 /* 451 * For now, we report if PG_reserved was found set, but do not 452 * clear it, and do not free the page. But we shall soon need 453 * to do more, for when the ZERO_PAGE count wraps negative. 454 */ 455 return PageReserved(page); 456 } 457 458 /* 459 * Frees a list of pages. 460 * Assumes all pages on list are in same zone, and of same order. 461 * count is the number of pages to free. 462 * 463 * If the zone was previously in an "all pages pinned" state then look to 464 * see if this freeing clears that state. 465 * 466 * And clear the zone's pages_scanned counter, to hold off the "all pages are 467 * pinned" detection logic. 468 */ 469 static void free_pages_bulk(struct zone *zone, int count, 470 struct list_head *list, int order) 471 { 472 spin_lock(&zone->lock); 473 zone->all_unreclaimable = 0; 474 zone->pages_scanned = 0; 475 while (count--) { 476 struct page *page; 477 478 VM_BUG_ON(list_empty(list)); 479 page = list_entry(list->prev, struct page, lru); 480 /* have to delete it as __free_one_page list manipulates */ 481 list_del(&page->lru); 482 __free_one_page(page, zone, order); 483 } 484 spin_unlock(&zone->lock); 485 } 486 487 static void free_one_page(struct zone *zone, struct page *page, int order) 488 { 489 spin_lock(&zone->lock); 490 zone->all_unreclaimable = 0; 491 zone->pages_scanned = 0; 492 __free_one_page(page, zone, order); 493 spin_unlock(&zone->lock); 494 } 495 496 static void __free_pages_ok(struct page *page, unsigned int order) 497 { 498 unsigned long flags; 499 int i; 500 int reserved = 0; 501 502 for (i = 0 ; i < (1 << order) ; ++i) 503 reserved += free_pages_check(page + i); 504 if (reserved) 505 return; 506 507 if (!PageHighMem(page)) 508 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order); 509 arch_free_page(page, order); 510 kernel_map_pages(page, 1 << order, 0); 511 512 local_irq_save(flags); 513 __count_vm_events(PGFREE, 1 << order); 514 free_one_page(page_zone(page), page, order); 515 local_irq_restore(flags); 516 } 517 518 /* 519 * permit the bootmem allocator to evade page validation on high-order frees 520 */ 521 void fastcall __init __free_pages_bootmem(struct page *page, unsigned int order) 522 { 523 if (order == 0) { 524 __ClearPageReserved(page); 525 set_page_count(page, 0); 526 set_page_refcounted(page); 527 __free_page(page); 528 } else { 529 int loop; 530 531 prefetchw(page); 532 for (loop = 0; loop < BITS_PER_LONG; loop++) { 533 struct page *p = &page[loop]; 534 535 if (loop + 1 < BITS_PER_LONG) 536 prefetchw(p + 1); 537 __ClearPageReserved(p); 538 set_page_count(p, 0); 539 } 540 541 set_page_refcounted(page); 542 __free_pages(page, order); 543 } 544 } 545 546 547 /* 548 * The order of subdivision here is critical for the IO subsystem. 549 * Please do not alter this order without good reasons and regression 550 * testing. Specifically, as large blocks of memory are subdivided, 551 * the order in which smaller blocks are delivered depends on the order 552 * they're subdivided in this function. This is the primary factor 553 * influencing the order in which pages are delivered to the IO 554 * subsystem according to empirical testing, and this is also justified 555 * by considering the behavior of a buddy system containing a single 556 * large block of memory acted on by a series of small allocations. 557 * This behavior is a critical factor in sglist merging's success. 558 * 559 * -- wli 560 */ 561 static inline void expand(struct zone *zone, struct page *page, 562 int low, int high, struct free_area *area) 563 { 564 unsigned long size = 1 << high; 565 566 while (high > low) { 567 area--; 568 high--; 569 size >>= 1; 570 VM_BUG_ON(bad_range(zone, &page[size])); 571 list_add(&page[size].lru, &area->free_list); 572 area->nr_free++; 573 set_page_order(&page[size], high); 574 } 575 } 576 577 /* 578 * This page is about to be returned from the page allocator 579 */ 580 static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) 581 { 582 if (unlikely(page_mapcount(page) | 583 (page->mapping != NULL) | 584 (page_count(page) != 0) | 585 (page->flags & ( 586 1 << PG_lru | 587 1 << PG_private | 588 1 << PG_locked | 589 1 << PG_active | 590 1 << PG_dirty | 591 1 << PG_reclaim | 592 1 << PG_slab | 593 1 << PG_swapcache | 594 1 << PG_writeback | 595 1 << PG_reserved | 596 1 << PG_buddy )))) 597 bad_page(page); 598 599 /* 600 * For now, we report if PG_reserved was found set, but do not 601 * clear it, and do not allocate the page: as a safety net. 602 */ 603 if (PageReserved(page)) 604 return 1; 605 606 page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 607 1 << PG_referenced | 1 << PG_arch_1 | 608 1 << PG_owner_priv_1 | 1 << PG_mappedtodisk); 609 set_page_private(page, 0); 610 set_page_refcounted(page); 611 612 arch_alloc_page(page, order); 613 kernel_map_pages(page, 1 << order, 1); 614 615 if (gfp_flags & __GFP_ZERO) 616 prep_zero_page(page, order, gfp_flags); 617 618 if (order && (gfp_flags & __GFP_COMP)) 619 prep_compound_page(page, order); 620 621 return 0; 622 } 623 624 /* 625 * Do the hard work of removing an element from the buddy allocator. 626 * Call me with the zone->lock already held. 627 */ 628 static struct page *__rmqueue(struct zone *zone, unsigned int order) 629 { 630 struct free_area * area; 631 unsigned int current_order; 632 struct page *page; 633 634 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 635 area = zone->free_area + current_order; 636 if (list_empty(&area->free_list)) 637 continue; 638 639 page = list_entry(area->free_list.next, struct page, lru); 640 list_del(&page->lru); 641 rmv_page_order(page); 642 area->nr_free--; 643 __mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order)); 644 expand(zone, page, order, current_order, area); 645 return page; 646 } 647 648 return NULL; 649 } 650 651 /* 652 * Obtain a specified number of elements from the buddy allocator, all under 653 * a single hold of the lock, for efficiency. Add them to the supplied list. 654 * Returns the number of new pages which were placed at *list. 655 */ 656 static int rmqueue_bulk(struct zone *zone, unsigned int order, 657 unsigned long count, struct list_head *list) 658 { 659 int i; 660 661 spin_lock(&zone->lock); 662 for (i = 0; i < count; ++i) { 663 struct page *page = __rmqueue(zone, order); 664 if (unlikely(page == NULL)) 665 break; 666 list_add_tail(&page->lru, list); 667 } 668 spin_unlock(&zone->lock); 669 return i; 670 } 671 672 #if MAX_NUMNODES > 1 673 int nr_node_ids __read_mostly = MAX_NUMNODES; 674 EXPORT_SYMBOL(nr_node_ids); 675 676 /* 677 * Figure out the number of possible node ids. 678 */ 679 static void __init setup_nr_node_ids(void) 680 { 681 unsigned int node; 682 unsigned int highest = 0; 683 684 for_each_node_mask(node, node_possible_map) 685 highest = node; 686 nr_node_ids = highest + 1; 687 } 688 #else 689 static void __init setup_nr_node_ids(void) {} 690 #endif 691 692 #ifdef CONFIG_NUMA 693 /* 694 * Called from the vmstat counter updater to drain pagesets of this 695 * currently executing processor on remote nodes after they have 696 * expired. 697 * 698 * Note that this function must be called with the thread pinned to 699 * a single processor. 700 */ 701 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) 702 { 703 unsigned long flags; 704 int to_drain; 705 706 local_irq_save(flags); 707 if (pcp->count >= pcp->batch) 708 to_drain = pcp->batch; 709 else 710 to_drain = pcp->count; 711 free_pages_bulk(zone, to_drain, &pcp->list, 0); 712 pcp->count -= to_drain; 713 local_irq_restore(flags); 714 } 715 #endif 716 717 static void __drain_pages(unsigned int cpu) 718 { 719 unsigned long flags; 720 struct zone *zone; 721 int i; 722 723 for_each_zone(zone) { 724 struct per_cpu_pageset *pset; 725 726 if (!populated_zone(zone)) 727 continue; 728 729 pset = zone_pcp(zone, cpu); 730 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) { 731 struct per_cpu_pages *pcp; 732 733 pcp = &pset->pcp[i]; 734 local_irq_save(flags); 735 free_pages_bulk(zone, pcp->count, &pcp->list, 0); 736 pcp->count = 0; 737 local_irq_restore(flags); 738 } 739 } 740 } 741 742 #ifdef CONFIG_PM 743 744 void mark_free_pages(struct zone *zone) 745 { 746 unsigned long pfn, max_zone_pfn; 747 unsigned long flags; 748 int order; 749 struct list_head *curr; 750 751 if (!zone->spanned_pages) 752 return; 753 754 spin_lock_irqsave(&zone->lock, flags); 755 756 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; 757 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 758 if (pfn_valid(pfn)) { 759 struct page *page = pfn_to_page(pfn); 760 761 if (!swsusp_page_is_forbidden(page)) 762 swsusp_unset_page_free(page); 763 } 764 765 for (order = MAX_ORDER - 1; order >= 0; --order) 766 list_for_each(curr, &zone->free_area[order].free_list) { 767 unsigned long i; 768 769 pfn = page_to_pfn(list_entry(curr, struct page, lru)); 770 for (i = 0; i < (1UL << order); i++) 771 swsusp_set_page_free(pfn_to_page(pfn + i)); 772 } 773 774 spin_unlock_irqrestore(&zone->lock, flags); 775 } 776 777 /* 778 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 779 */ 780 void drain_local_pages(void) 781 { 782 unsigned long flags; 783 784 local_irq_save(flags); 785 __drain_pages(smp_processor_id()); 786 local_irq_restore(flags); 787 } 788 #endif /* CONFIG_PM */ 789 790 /* 791 * Free a 0-order page 792 */ 793 static void fastcall free_hot_cold_page(struct page *page, int cold) 794 { 795 struct zone *zone = page_zone(page); 796 struct per_cpu_pages *pcp; 797 unsigned long flags; 798 799 if (PageAnon(page)) 800 page->mapping = NULL; 801 if (free_pages_check(page)) 802 return; 803 804 if (!PageHighMem(page)) 805 debug_check_no_locks_freed(page_address(page), PAGE_SIZE); 806 arch_free_page(page, 0); 807 kernel_map_pages(page, 1, 0); 808 809 pcp = &zone_pcp(zone, get_cpu())->pcp[cold]; 810 local_irq_save(flags); 811 __count_vm_event(PGFREE); 812 list_add(&page->lru, &pcp->list); 813 pcp->count++; 814 if (pcp->count >= pcp->high) { 815 free_pages_bulk(zone, pcp->batch, &pcp->list, 0); 816 pcp->count -= pcp->batch; 817 } 818 local_irq_restore(flags); 819 put_cpu(); 820 } 821 822 void fastcall free_hot_page(struct page *page) 823 { 824 free_hot_cold_page(page, 0); 825 } 826 827 void fastcall free_cold_page(struct page *page) 828 { 829 free_hot_cold_page(page, 1); 830 } 831 832 /* 833 * split_page takes a non-compound higher-order page, and splits it into 834 * n (1<<order) sub-pages: page[0..n] 835 * Each sub-page must be freed individually. 836 * 837 * Note: this is probably too low level an operation for use in drivers. 838 * Please consult with lkml before using this in your driver. 839 */ 840 void split_page(struct page *page, unsigned int order) 841 { 842 int i; 843 844 VM_BUG_ON(PageCompound(page)); 845 VM_BUG_ON(!page_count(page)); 846 for (i = 1; i < (1 << order); i++) 847 set_page_refcounted(page + i); 848 } 849 850 /* 851 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 852 * we cheat by calling it from here, in the order > 0 path. Saves a branch 853 * or two. 854 */ 855 static struct page *buffered_rmqueue(struct zonelist *zonelist, 856 struct zone *zone, int order, gfp_t gfp_flags) 857 { 858 unsigned long flags; 859 struct page *page; 860 int cold = !!(gfp_flags & __GFP_COLD); 861 int cpu; 862 863 again: 864 cpu = get_cpu(); 865 if (likely(order == 0)) { 866 struct per_cpu_pages *pcp; 867 868 pcp = &zone_pcp(zone, cpu)->pcp[cold]; 869 local_irq_save(flags); 870 if (!pcp->count) { 871 pcp->count = rmqueue_bulk(zone, 0, 872 pcp->batch, &pcp->list); 873 if (unlikely(!pcp->count)) 874 goto failed; 875 } 876 page = list_entry(pcp->list.next, struct page, lru); 877 list_del(&page->lru); 878 pcp->count--; 879 } else { 880 spin_lock_irqsave(&zone->lock, flags); 881 page = __rmqueue(zone, order); 882 spin_unlock(&zone->lock); 883 if (!page) 884 goto failed; 885 } 886 887 __count_zone_vm_events(PGALLOC, zone, 1 << order); 888 zone_statistics(zonelist, zone); 889 local_irq_restore(flags); 890 put_cpu(); 891 892 VM_BUG_ON(bad_range(zone, page)); 893 if (prep_new_page(page, order, gfp_flags)) 894 goto again; 895 return page; 896 897 failed: 898 local_irq_restore(flags); 899 put_cpu(); 900 return NULL; 901 } 902 903 #define ALLOC_NO_WATERMARKS 0x01 /* don't check watermarks at all */ 904 #define ALLOC_WMARK_MIN 0x02 /* use pages_min watermark */ 905 #define ALLOC_WMARK_LOW 0x04 /* use pages_low watermark */ 906 #define ALLOC_WMARK_HIGH 0x08 /* use pages_high watermark */ 907 #define ALLOC_HARDER 0x10 /* try to alloc harder */ 908 #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ 909 #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ 910 911 #ifdef CONFIG_FAIL_PAGE_ALLOC 912 913 static struct fail_page_alloc_attr { 914 struct fault_attr attr; 915 916 u32 ignore_gfp_highmem; 917 u32 ignore_gfp_wait; 918 919 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 920 921 struct dentry *ignore_gfp_highmem_file; 922 struct dentry *ignore_gfp_wait_file; 923 924 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 925 926 } fail_page_alloc = { 927 .attr = FAULT_ATTR_INITIALIZER, 928 .ignore_gfp_wait = 1, 929 .ignore_gfp_highmem = 1, 930 }; 931 932 static int __init setup_fail_page_alloc(char *str) 933 { 934 return setup_fault_attr(&fail_page_alloc.attr, str); 935 } 936 __setup("fail_page_alloc=", setup_fail_page_alloc); 937 938 static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 939 { 940 if (gfp_mask & __GFP_NOFAIL) 941 return 0; 942 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 943 return 0; 944 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) 945 return 0; 946 947 return should_fail(&fail_page_alloc.attr, 1 << order); 948 } 949 950 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 951 952 static int __init fail_page_alloc_debugfs(void) 953 { 954 mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; 955 struct dentry *dir; 956 int err; 957 958 err = init_fault_attr_dentries(&fail_page_alloc.attr, 959 "fail_page_alloc"); 960 if (err) 961 return err; 962 dir = fail_page_alloc.attr.dentries.dir; 963 964 fail_page_alloc.ignore_gfp_wait_file = 965 debugfs_create_bool("ignore-gfp-wait", mode, dir, 966 &fail_page_alloc.ignore_gfp_wait); 967 968 fail_page_alloc.ignore_gfp_highmem_file = 969 debugfs_create_bool("ignore-gfp-highmem", mode, dir, 970 &fail_page_alloc.ignore_gfp_highmem); 971 972 if (!fail_page_alloc.ignore_gfp_wait_file || 973 !fail_page_alloc.ignore_gfp_highmem_file) { 974 err = -ENOMEM; 975 debugfs_remove(fail_page_alloc.ignore_gfp_wait_file); 976 debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file); 977 cleanup_fault_attr_dentries(&fail_page_alloc.attr); 978 } 979 980 return err; 981 } 982 983 late_initcall(fail_page_alloc_debugfs); 984 985 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 986 987 #else /* CONFIG_FAIL_PAGE_ALLOC */ 988 989 static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 990 { 991 return 0; 992 } 993 994 #endif /* CONFIG_FAIL_PAGE_ALLOC */ 995 996 /* 997 * Return 1 if free pages are above 'mark'. This takes into account the order 998 * of the allocation. 999 */ 1000 int zone_watermark_ok(struct zone *z, int order, unsigned long mark, 1001 int classzone_idx, int alloc_flags) 1002 { 1003 /* free_pages my go negative - that's OK */ 1004 long min = mark; 1005 long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1; 1006 int o; 1007 1008 if (alloc_flags & ALLOC_HIGH) 1009 min -= min / 2; 1010 if (alloc_flags & ALLOC_HARDER) 1011 min -= min / 4; 1012 1013 if (free_pages <= min + z->lowmem_reserve[classzone_idx]) 1014 return 0; 1015 for (o = 0; o < order; o++) { 1016 /* At the next order, this order's pages become unavailable */ 1017 free_pages -= z->free_area[o].nr_free << o; 1018 1019 /* Require fewer higher order pages to be free */ 1020 min >>= 1; 1021 1022 if (free_pages <= min) 1023 return 0; 1024 } 1025 return 1; 1026 } 1027 1028 #ifdef CONFIG_NUMA 1029 /* 1030 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to 1031 * skip over zones that are not allowed by the cpuset, or that have 1032 * been recently (in last second) found to be nearly full. See further 1033 * comments in mmzone.h. Reduces cache footprint of zonelist scans 1034 * that have to skip over alot of full or unallowed zones. 1035 * 1036 * If the zonelist cache is present in the passed in zonelist, then 1037 * returns a pointer to the allowed node mask (either the current 1038 * tasks mems_allowed, or node_online_map.) 1039 * 1040 * If the zonelist cache is not available for this zonelist, does 1041 * nothing and returns NULL. 1042 * 1043 * If the fullzones BITMAP in the zonelist cache is stale (more than 1044 * a second since last zap'd) then we zap it out (clear its bits.) 1045 * 1046 * We hold off even calling zlc_setup, until after we've checked the 1047 * first zone in the zonelist, on the theory that most allocations will 1048 * be satisfied from that first zone, so best to examine that zone as 1049 * quickly as we can. 1050 */ 1051 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1052 { 1053 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1054 nodemask_t *allowednodes; /* zonelist_cache approximation */ 1055 1056 zlc = zonelist->zlcache_ptr; 1057 if (!zlc) 1058 return NULL; 1059 1060 if (jiffies - zlc->last_full_zap > 1 * HZ) { 1061 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1062 zlc->last_full_zap = jiffies; 1063 } 1064 1065 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? 1066 &cpuset_current_mems_allowed : 1067 &node_online_map; 1068 return allowednodes; 1069 } 1070 1071 /* 1072 * Given 'z' scanning a zonelist, run a couple of quick checks to see 1073 * if it is worth looking at further for free memory: 1074 * 1) Check that the zone isn't thought to be full (doesn't have its 1075 * bit set in the zonelist_cache fullzones BITMAP). 1076 * 2) Check that the zones node (obtained from the zonelist_cache 1077 * z_to_n[] mapping) is allowed in the passed in allowednodes mask. 1078 * Return true (non-zero) if zone is worth looking at further, or 1079 * else return false (zero) if it is not. 1080 * 1081 * This check -ignores- the distinction between various watermarks, 1082 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is 1083 * found to be full for any variation of these watermarks, it will 1084 * be considered full for up to one second by all requests, unless 1085 * we are so low on memory on all allowed nodes that we are forced 1086 * into the second scan of the zonelist. 1087 * 1088 * In the second scan we ignore this zonelist cache and exactly 1089 * apply the watermarks to all zones, even it is slower to do so. 1090 * We are low on memory in the second scan, and should leave no stone 1091 * unturned looking for a free page. 1092 */ 1093 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zone **z, 1094 nodemask_t *allowednodes) 1095 { 1096 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1097 int i; /* index of *z in zonelist zones */ 1098 int n; /* node that zone *z is on */ 1099 1100 zlc = zonelist->zlcache_ptr; 1101 if (!zlc) 1102 return 1; 1103 1104 i = z - zonelist->zones; 1105 n = zlc->z_to_n[i]; 1106 1107 /* This zone is worth trying if it is allowed but not full */ 1108 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); 1109 } 1110 1111 /* 1112 * Given 'z' scanning a zonelist, set the corresponding bit in 1113 * zlc->fullzones, so that subsequent attempts to allocate a page 1114 * from that zone don't waste time re-examining it. 1115 */ 1116 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **z) 1117 { 1118 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1119 int i; /* index of *z in zonelist zones */ 1120 1121 zlc = zonelist->zlcache_ptr; 1122 if (!zlc) 1123 return; 1124 1125 i = z - zonelist->zones; 1126 1127 set_bit(i, zlc->fullzones); 1128 } 1129 1130 #else /* CONFIG_NUMA */ 1131 1132 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1133 { 1134 return NULL; 1135 } 1136 1137 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zone **z, 1138 nodemask_t *allowednodes) 1139 { 1140 return 1; 1141 } 1142 1143 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **z) 1144 { 1145 } 1146 #endif /* CONFIG_NUMA */ 1147 1148 /* 1149 * get_page_from_freelist goes through the zonelist trying to allocate 1150 * a page. 1151 */ 1152 static struct page * 1153 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, 1154 struct zonelist *zonelist, int alloc_flags) 1155 { 1156 struct zone **z; 1157 struct page *page = NULL; 1158 int classzone_idx = zone_idx(zonelist->zones[0]); 1159 struct zone *zone; 1160 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ 1161 int zlc_active = 0; /* set if using zonelist_cache */ 1162 int did_zlc_setup = 0; /* just call zlc_setup() one time */ 1163 1164 zonelist_scan: 1165 /* 1166 * Scan zonelist, looking for a zone with enough free. 1167 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1168 */ 1169 z = zonelist->zones; 1170 1171 do { 1172 if (NUMA_BUILD && zlc_active && 1173 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 1174 continue; 1175 zone = *z; 1176 if (unlikely(NUMA_BUILD && (gfp_mask & __GFP_THISNODE) && 1177 zone->zone_pgdat != zonelist->zones[0]->zone_pgdat)) 1178 break; 1179 if ((alloc_flags & ALLOC_CPUSET) && 1180 !cpuset_zone_allowed_softwall(zone, gfp_mask)) 1181 goto try_next_zone; 1182 1183 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { 1184 unsigned long mark; 1185 if (alloc_flags & ALLOC_WMARK_MIN) 1186 mark = zone->pages_min; 1187 else if (alloc_flags & ALLOC_WMARK_LOW) 1188 mark = zone->pages_low; 1189 else 1190 mark = zone->pages_high; 1191 if (!zone_watermark_ok(zone, order, mark, 1192 classzone_idx, alloc_flags)) { 1193 if (!zone_reclaim_mode || 1194 !zone_reclaim(zone, gfp_mask, order)) 1195 goto this_zone_full; 1196 } 1197 } 1198 1199 page = buffered_rmqueue(zonelist, zone, order, gfp_mask); 1200 if (page) 1201 break; 1202 this_zone_full: 1203 if (NUMA_BUILD) 1204 zlc_mark_zone_full(zonelist, z); 1205 try_next_zone: 1206 if (NUMA_BUILD && !did_zlc_setup) { 1207 /* we do zlc_setup after the first zone is tried */ 1208 allowednodes = zlc_setup(zonelist, alloc_flags); 1209 zlc_active = 1; 1210 did_zlc_setup = 1; 1211 } 1212 } while (*(++z) != NULL); 1213 1214 if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) { 1215 /* Disable zlc cache for second zonelist scan */ 1216 zlc_active = 0; 1217 goto zonelist_scan; 1218 } 1219 return page; 1220 } 1221 1222 /* 1223 * This is the 'heart' of the zoned buddy allocator. 1224 */ 1225 struct page * fastcall 1226 __alloc_pages(gfp_t gfp_mask, unsigned int order, 1227 struct zonelist *zonelist) 1228 { 1229 const gfp_t wait = gfp_mask & __GFP_WAIT; 1230 struct zone **z; 1231 struct page *page; 1232 struct reclaim_state reclaim_state; 1233 struct task_struct *p = current; 1234 int do_retry; 1235 int alloc_flags; 1236 int did_some_progress; 1237 1238 might_sleep_if(wait); 1239 1240 if (should_fail_alloc_page(gfp_mask, order)) 1241 return NULL; 1242 1243 restart: 1244 z = zonelist->zones; /* the list of zones suitable for gfp_mask */ 1245 1246 if (unlikely(*z == NULL)) { 1247 /* Should this ever happen?? */ 1248 return NULL; 1249 } 1250 1251 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order, 1252 zonelist, ALLOC_WMARK_LOW|ALLOC_CPUSET); 1253 if (page) 1254 goto got_pg; 1255 1256 /* 1257 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and 1258 * __GFP_NOWARN set) should not cause reclaim since the subsystem 1259 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim 1260 * using a larger set of nodes after it has established that the 1261 * allowed per node queues are empty and that nodes are 1262 * over allocated. 1263 */ 1264 if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) 1265 goto nopage; 1266 1267 for (z = zonelist->zones; *z; z++) 1268 wakeup_kswapd(*z, order); 1269 1270 /* 1271 * OK, we're below the kswapd watermark and have kicked background 1272 * reclaim. Now things get more complex, so set up alloc_flags according 1273 * to how we want to proceed. 1274 * 1275 * The caller may dip into page reserves a bit more if the caller 1276 * cannot run direct reclaim, or if the caller has realtime scheduling 1277 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will 1278 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). 1279 */ 1280 alloc_flags = ALLOC_WMARK_MIN; 1281 if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait) 1282 alloc_flags |= ALLOC_HARDER; 1283 if (gfp_mask & __GFP_HIGH) 1284 alloc_flags |= ALLOC_HIGH; 1285 if (wait) 1286 alloc_flags |= ALLOC_CPUSET; 1287 1288 /* 1289 * Go through the zonelist again. Let __GFP_HIGH and allocations 1290 * coming from realtime tasks go deeper into reserves. 1291 * 1292 * This is the last chance, in general, before the goto nopage. 1293 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. 1294 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1295 */ 1296 page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags); 1297 if (page) 1298 goto got_pg; 1299 1300 /* This allocation should allow future memory freeing. */ 1301 1302 rebalance: 1303 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) 1304 && !in_interrupt()) { 1305 if (!(gfp_mask & __GFP_NOMEMALLOC)) { 1306 nofail_alloc: 1307 /* go through the zonelist yet again, ignoring mins */ 1308 page = get_page_from_freelist(gfp_mask, order, 1309 zonelist, ALLOC_NO_WATERMARKS); 1310 if (page) 1311 goto got_pg; 1312 if (gfp_mask & __GFP_NOFAIL) { 1313 congestion_wait(WRITE, HZ/50); 1314 goto nofail_alloc; 1315 } 1316 } 1317 goto nopage; 1318 } 1319 1320 /* Atomic allocations - we can't balance anything */ 1321 if (!wait) 1322 goto nopage; 1323 1324 cond_resched(); 1325 1326 /* We now go into synchronous reclaim */ 1327 cpuset_memory_pressure_bump(); 1328 p->flags |= PF_MEMALLOC; 1329 reclaim_state.reclaimed_slab = 0; 1330 p->reclaim_state = &reclaim_state; 1331 1332 did_some_progress = try_to_free_pages(zonelist->zones, gfp_mask); 1333 1334 p->reclaim_state = NULL; 1335 p->flags &= ~PF_MEMALLOC; 1336 1337 cond_resched(); 1338 1339 if (likely(did_some_progress)) { 1340 page = get_page_from_freelist(gfp_mask, order, 1341 zonelist, alloc_flags); 1342 if (page) 1343 goto got_pg; 1344 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { 1345 /* 1346 * Go through the zonelist yet one more time, keep 1347 * very high watermark here, this is only to catch 1348 * a parallel oom killing, we must fail if we're still 1349 * under heavy pressure. 1350 */ 1351 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order, 1352 zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET); 1353 if (page) 1354 goto got_pg; 1355 1356 out_of_memory(zonelist, gfp_mask, order); 1357 goto restart; 1358 } 1359 1360 /* 1361 * Don't let big-order allocations loop unless the caller explicitly 1362 * requests that. Wait for some write requests to complete then retry. 1363 * 1364 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order 1365 * <= 3, but that may not be true in other implementations. 1366 */ 1367 do_retry = 0; 1368 if (!(gfp_mask & __GFP_NORETRY)) { 1369 if ((order <= 3) || (gfp_mask & __GFP_REPEAT)) 1370 do_retry = 1; 1371 if (gfp_mask & __GFP_NOFAIL) 1372 do_retry = 1; 1373 } 1374 if (do_retry) { 1375 congestion_wait(WRITE, HZ/50); 1376 goto rebalance; 1377 } 1378 1379 nopage: 1380 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { 1381 printk(KERN_WARNING "%s: page allocation failure." 1382 " order:%d, mode:0x%x\n", 1383 p->comm, order, gfp_mask); 1384 dump_stack(); 1385 show_mem(); 1386 } 1387 got_pg: 1388 return page; 1389 } 1390 1391 EXPORT_SYMBOL(__alloc_pages); 1392 1393 /* 1394 * Common helper functions. 1395 */ 1396 fastcall unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 1397 { 1398 struct page * page; 1399 page = alloc_pages(gfp_mask, order); 1400 if (!page) 1401 return 0; 1402 return (unsigned long) page_address(page); 1403 } 1404 1405 EXPORT_SYMBOL(__get_free_pages); 1406 1407 fastcall unsigned long get_zeroed_page(gfp_t gfp_mask) 1408 { 1409 struct page * page; 1410 1411 /* 1412 * get_zeroed_page() returns a 32-bit address, which cannot represent 1413 * a highmem page 1414 */ 1415 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 1416 1417 page = alloc_pages(gfp_mask | __GFP_ZERO, 0); 1418 if (page) 1419 return (unsigned long) page_address(page); 1420 return 0; 1421 } 1422 1423 EXPORT_SYMBOL(get_zeroed_page); 1424 1425 void __pagevec_free(struct pagevec *pvec) 1426 { 1427 int i = pagevec_count(pvec); 1428 1429 while (--i >= 0) 1430 free_hot_cold_page(pvec->pages[i], pvec->cold); 1431 } 1432 1433 fastcall void __free_pages(struct page *page, unsigned int order) 1434 { 1435 if (put_page_testzero(page)) { 1436 if (order == 0) 1437 free_hot_page(page); 1438 else 1439 __free_pages_ok(page, order); 1440 } 1441 } 1442 1443 EXPORT_SYMBOL(__free_pages); 1444 1445 fastcall void free_pages(unsigned long addr, unsigned int order) 1446 { 1447 if (addr != 0) { 1448 VM_BUG_ON(!virt_addr_valid((void *)addr)); 1449 __free_pages(virt_to_page((void *)addr), order); 1450 } 1451 } 1452 1453 EXPORT_SYMBOL(free_pages); 1454 1455 static unsigned int nr_free_zone_pages(int offset) 1456 { 1457 /* Just pick one node, since fallback list is circular */ 1458 pg_data_t *pgdat = NODE_DATA(numa_node_id()); 1459 unsigned int sum = 0; 1460 1461 struct zonelist *zonelist = pgdat->node_zonelists + offset; 1462 struct zone **zonep = zonelist->zones; 1463 struct zone *zone; 1464 1465 for (zone = *zonep++; zone; zone = *zonep++) { 1466 unsigned long size = zone->present_pages; 1467 unsigned long high = zone->pages_high; 1468 if (size > high) 1469 sum += size - high; 1470 } 1471 1472 return sum; 1473 } 1474 1475 /* 1476 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL 1477 */ 1478 unsigned int nr_free_buffer_pages(void) 1479 { 1480 return nr_free_zone_pages(gfp_zone(GFP_USER)); 1481 } 1482 1483 /* 1484 * Amount of free RAM allocatable within all zones 1485 */ 1486 unsigned int nr_free_pagecache_pages(void) 1487 { 1488 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER)); 1489 } 1490 1491 static inline void show_node(struct zone *zone) 1492 { 1493 if (NUMA_BUILD) 1494 printk("Node %d ", zone_to_nid(zone)); 1495 } 1496 1497 void si_meminfo(struct sysinfo *val) 1498 { 1499 val->totalram = totalram_pages; 1500 val->sharedram = 0; 1501 val->freeram = global_page_state(NR_FREE_PAGES); 1502 val->bufferram = nr_blockdev_pages(); 1503 val->totalhigh = totalhigh_pages; 1504 val->freehigh = nr_free_highpages(); 1505 val->mem_unit = PAGE_SIZE; 1506 } 1507 1508 EXPORT_SYMBOL(si_meminfo); 1509 1510 #ifdef CONFIG_NUMA 1511 void si_meminfo_node(struct sysinfo *val, int nid) 1512 { 1513 pg_data_t *pgdat = NODE_DATA(nid); 1514 1515 val->totalram = pgdat->node_present_pages; 1516 val->freeram = node_page_state(nid, NR_FREE_PAGES); 1517 #ifdef CONFIG_HIGHMEM 1518 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; 1519 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], 1520 NR_FREE_PAGES); 1521 #else 1522 val->totalhigh = 0; 1523 val->freehigh = 0; 1524 #endif 1525 val->mem_unit = PAGE_SIZE; 1526 } 1527 #endif 1528 1529 #define K(x) ((x) << (PAGE_SHIFT-10)) 1530 1531 /* 1532 * Show free area list (used inside shift_scroll-lock stuff) 1533 * We also calculate the percentage fragmentation. We do this by counting the 1534 * memory on each free list with the exception of the first item on the list. 1535 */ 1536 void show_free_areas(void) 1537 { 1538 int cpu; 1539 struct zone *zone; 1540 1541 for_each_zone(zone) { 1542 if (!populated_zone(zone)) 1543 continue; 1544 1545 show_node(zone); 1546 printk("%s per-cpu:\n", zone->name); 1547 1548 for_each_online_cpu(cpu) { 1549 struct per_cpu_pageset *pageset; 1550 1551 pageset = zone_pcp(zone, cpu); 1552 1553 printk("CPU %4d: Hot: hi:%5d, btch:%4d usd:%4d " 1554 "Cold: hi:%5d, btch:%4d usd:%4d\n", 1555 cpu, pageset->pcp[0].high, 1556 pageset->pcp[0].batch, pageset->pcp[0].count, 1557 pageset->pcp[1].high, pageset->pcp[1].batch, 1558 pageset->pcp[1].count); 1559 } 1560 } 1561 1562 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu\n" 1563 " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n", 1564 global_page_state(NR_ACTIVE), 1565 global_page_state(NR_INACTIVE), 1566 global_page_state(NR_FILE_DIRTY), 1567 global_page_state(NR_WRITEBACK), 1568 global_page_state(NR_UNSTABLE_NFS), 1569 global_page_state(NR_FREE_PAGES), 1570 global_page_state(NR_SLAB_RECLAIMABLE) + 1571 global_page_state(NR_SLAB_UNRECLAIMABLE), 1572 global_page_state(NR_FILE_MAPPED), 1573 global_page_state(NR_PAGETABLE), 1574 global_page_state(NR_BOUNCE)); 1575 1576 for_each_zone(zone) { 1577 int i; 1578 1579 if (!populated_zone(zone)) 1580 continue; 1581 1582 show_node(zone); 1583 printk("%s" 1584 " free:%lukB" 1585 " min:%lukB" 1586 " low:%lukB" 1587 " high:%lukB" 1588 " active:%lukB" 1589 " inactive:%lukB" 1590 " present:%lukB" 1591 " pages_scanned:%lu" 1592 " all_unreclaimable? %s" 1593 "\n", 1594 zone->name, 1595 K(zone_page_state(zone, NR_FREE_PAGES)), 1596 K(zone->pages_min), 1597 K(zone->pages_low), 1598 K(zone->pages_high), 1599 K(zone_page_state(zone, NR_ACTIVE)), 1600 K(zone_page_state(zone, NR_INACTIVE)), 1601 K(zone->present_pages), 1602 zone->pages_scanned, 1603 (zone->all_unreclaimable ? "yes" : "no") 1604 ); 1605 printk("lowmem_reserve[]:"); 1606 for (i = 0; i < MAX_NR_ZONES; i++) 1607 printk(" %lu", zone->lowmem_reserve[i]); 1608 printk("\n"); 1609 } 1610 1611 for_each_zone(zone) { 1612 unsigned long nr[MAX_ORDER], flags, order, total = 0; 1613 1614 if (!populated_zone(zone)) 1615 continue; 1616 1617 show_node(zone); 1618 printk("%s: ", zone->name); 1619 1620 spin_lock_irqsave(&zone->lock, flags); 1621 for (order = 0; order < MAX_ORDER; order++) { 1622 nr[order] = zone->free_area[order].nr_free; 1623 total += nr[order] << order; 1624 } 1625 spin_unlock_irqrestore(&zone->lock, flags); 1626 for (order = 0; order < MAX_ORDER; order++) 1627 printk("%lu*%lukB ", nr[order], K(1UL) << order); 1628 printk("= %lukB\n", K(total)); 1629 } 1630 1631 show_swap_cache_info(); 1632 } 1633 1634 /* 1635 * Builds allocation fallback zone lists. 1636 * 1637 * Add all populated zones of a node to the zonelist. 1638 */ 1639 static int __meminit build_zonelists_node(pg_data_t *pgdat, 1640 struct zonelist *zonelist, int nr_zones, enum zone_type zone_type) 1641 { 1642 struct zone *zone; 1643 1644 BUG_ON(zone_type >= MAX_NR_ZONES); 1645 zone_type++; 1646 1647 do { 1648 zone_type--; 1649 zone = pgdat->node_zones + zone_type; 1650 if (populated_zone(zone)) { 1651 zonelist->zones[nr_zones++] = zone; 1652 check_highest_zone(zone_type); 1653 } 1654 1655 } while (zone_type); 1656 return nr_zones; 1657 } 1658 1659 #ifdef CONFIG_NUMA 1660 #define MAX_NODE_LOAD (num_online_nodes()) 1661 static int __meminitdata node_load[MAX_NUMNODES]; 1662 /** 1663 * find_next_best_node - find the next node that should appear in a given node's fallback list 1664 * @node: node whose fallback list we're appending 1665 * @used_node_mask: nodemask_t of already used nodes 1666 * 1667 * We use a number of factors to determine which is the next node that should 1668 * appear on a given node's fallback list. The node should not have appeared 1669 * already in @node's fallback list, and it should be the next closest node 1670 * according to the distance array (which contains arbitrary distance values 1671 * from each node to each node in the system), and should also prefer nodes 1672 * with no CPUs, since presumably they'll have very little allocation pressure 1673 * on them otherwise. 1674 * It returns -1 if no node is found. 1675 */ 1676 static int __meminit find_next_best_node(int node, nodemask_t *used_node_mask) 1677 { 1678 int n, val; 1679 int min_val = INT_MAX; 1680 int best_node = -1; 1681 1682 /* Use the local node if we haven't already */ 1683 if (!node_isset(node, *used_node_mask)) { 1684 node_set(node, *used_node_mask); 1685 return node; 1686 } 1687 1688 for_each_online_node(n) { 1689 cpumask_t tmp; 1690 1691 /* Don't want a node to appear more than once */ 1692 if (node_isset(n, *used_node_mask)) 1693 continue; 1694 1695 /* Use the distance array to find the distance */ 1696 val = node_distance(node, n); 1697 1698 /* Penalize nodes under us ("prefer the next node") */ 1699 val += (n < node); 1700 1701 /* Give preference to headless and unused nodes */ 1702 tmp = node_to_cpumask(n); 1703 if (!cpus_empty(tmp)) 1704 val += PENALTY_FOR_NODE_WITH_CPUS; 1705 1706 /* Slight preference for less loaded node */ 1707 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 1708 val += node_load[n]; 1709 1710 if (val < min_val) { 1711 min_val = val; 1712 best_node = n; 1713 } 1714 } 1715 1716 if (best_node >= 0) 1717 node_set(best_node, *used_node_mask); 1718 1719 return best_node; 1720 } 1721 1722 static void __meminit build_zonelists(pg_data_t *pgdat) 1723 { 1724 int j, node, local_node; 1725 enum zone_type i; 1726 int prev_node, load; 1727 struct zonelist *zonelist; 1728 nodemask_t used_mask; 1729 1730 /* initialize zonelists */ 1731 for (i = 0; i < MAX_NR_ZONES; i++) { 1732 zonelist = pgdat->node_zonelists + i; 1733 zonelist->zones[0] = NULL; 1734 } 1735 1736 /* NUMA-aware ordering of nodes */ 1737 local_node = pgdat->node_id; 1738 load = num_online_nodes(); 1739 prev_node = local_node; 1740 nodes_clear(used_mask); 1741 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 1742 int distance = node_distance(local_node, node); 1743 1744 /* 1745 * If another node is sufficiently far away then it is better 1746 * to reclaim pages in a zone before going off node. 1747 */ 1748 if (distance > RECLAIM_DISTANCE) 1749 zone_reclaim_mode = 1; 1750 1751 /* 1752 * We don't want to pressure a particular node. 1753 * So adding penalty to the first node in same 1754 * distance group to make it round-robin. 1755 */ 1756 1757 if (distance != node_distance(local_node, prev_node)) 1758 node_load[node] += load; 1759 prev_node = node; 1760 load--; 1761 for (i = 0; i < MAX_NR_ZONES; i++) { 1762 zonelist = pgdat->node_zonelists + i; 1763 for (j = 0; zonelist->zones[j] != NULL; j++); 1764 1765 j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); 1766 zonelist->zones[j] = NULL; 1767 } 1768 } 1769 } 1770 1771 /* Construct the zonelist performance cache - see further mmzone.h */ 1772 static void __meminit build_zonelist_cache(pg_data_t *pgdat) 1773 { 1774 int i; 1775 1776 for (i = 0; i < MAX_NR_ZONES; i++) { 1777 struct zonelist *zonelist; 1778 struct zonelist_cache *zlc; 1779 struct zone **z; 1780 1781 zonelist = pgdat->node_zonelists + i; 1782 zonelist->zlcache_ptr = zlc = &zonelist->zlcache; 1783 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1784 for (z = zonelist->zones; *z; z++) 1785 zlc->z_to_n[z - zonelist->zones] = zone_to_nid(*z); 1786 } 1787 } 1788 1789 #else /* CONFIG_NUMA */ 1790 1791 static void __meminit build_zonelists(pg_data_t *pgdat) 1792 { 1793 int node, local_node; 1794 enum zone_type i,j; 1795 1796 local_node = pgdat->node_id; 1797 for (i = 0; i < MAX_NR_ZONES; i++) { 1798 struct zonelist *zonelist; 1799 1800 zonelist = pgdat->node_zonelists + i; 1801 1802 j = build_zonelists_node(pgdat, zonelist, 0, i); 1803 /* 1804 * Now we build the zonelist so that it contains the zones 1805 * of all the other nodes. 1806 * We don't want to pressure a particular node, so when 1807 * building the zones for node N, we make sure that the 1808 * zones coming right after the local ones are those from 1809 * node N+1 (modulo N) 1810 */ 1811 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 1812 if (!node_online(node)) 1813 continue; 1814 j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); 1815 } 1816 for (node = 0; node < local_node; node++) { 1817 if (!node_online(node)) 1818 continue; 1819 j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); 1820 } 1821 1822 zonelist->zones[j] = NULL; 1823 } 1824 } 1825 1826 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ 1827 static void __meminit build_zonelist_cache(pg_data_t *pgdat) 1828 { 1829 int i; 1830 1831 for (i = 0; i < MAX_NR_ZONES; i++) 1832 pgdat->node_zonelists[i].zlcache_ptr = NULL; 1833 } 1834 1835 #endif /* CONFIG_NUMA */ 1836 1837 /* return values int ....just for stop_machine_run() */ 1838 static int __meminit __build_all_zonelists(void *dummy) 1839 { 1840 int nid; 1841 1842 for_each_online_node(nid) { 1843 build_zonelists(NODE_DATA(nid)); 1844 build_zonelist_cache(NODE_DATA(nid)); 1845 } 1846 return 0; 1847 } 1848 1849 void __meminit build_all_zonelists(void) 1850 { 1851 if (system_state == SYSTEM_BOOTING) { 1852 __build_all_zonelists(NULL); 1853 cpuset_init_current_mems_allowed(); 1854 } else { 1855 /* we have to stop all cpus to guaranntee there is no user 1856 of zonelist */ 1857 stop_machine_run(__build_all_zonelists, NULL, NR_CPUS); 1858 /* cpuset refresh routine should be here */ 1859 } 1860 vm_total_pages = nr_free_pagecache_pages(); 1861 printk("Built %i zonelists. Total pages: %ld\n", 1862 num_online_nodes(), vm_total_pages); 1863 } 1864 1865 /* 1866 * Helper functions to size the waitqueue hash table. 1867 * Essentially these want to choose hash table sizes sufficiently 1868 * large so that collisions trying to wait on pages are rare. 1869 * But in fact, the number of active page waitqueues on typical 1870 * systems is ridiculously low, less than 200. So this is even 1871 * conservative, even though it seems large. 1872 * 1873 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 1874 * waitqueues, i.e. the size of the waitq table given the number of pages. 1875 */ 1876 #define PAGES_PER_WAITQUEUE 256 1877 1878 #ifndef CONFIG_MEMORY_HOTPLUG 1879 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 1880 { 1881 unsigned long size = 1; 1882 1883 pages /= PAGES_PER_WAITQUEUE; 1884 1885 while (size < pages) 1886 size <<= 1; 1887 1888 /* 1889 * Once we have dozens or even hundreds of threads sleeping 1890 * on IO we've got bigger problems than wait queue collision. 1891 * Limit the size of the wait table to a reasonable size. 1892 */ 1893 size = min(size, 4096UL); 1894 1895 return max(size, 4UL); 1896 } 1897 #else 1898 /* 1899 * A zone's size might be changed by hot-add, so it is not possible to determine 1900 * a suitable size for its wait_table. So we use the maximum size now. 1901 * 1902 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: 1903 * 1904 * i386 (preemption config) : 4096 x 16 = 64Kbyte. 1905 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. 1906 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. 1907 * 1908 * The maximum entries are prepared when a zone's memory is (512K + 256) pages 1909 * or more by the traditional way. (See above). It equals: 1910 * 1911 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. 1912 * ia64(16K page size) : = ( 8G + 4M)byte. 1913 * powerpc (64K page size) : = (32G +16M)byte. 1914 */ 1915 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 1916 { 1917 return 4096UL; 1918 } 1919 #endif 1920 1921 /* 1922 * This is an integer logarithm so that shifts can be used later 1923 * to extract the more random high bits from the multiplicative 1924 * hash function before the remainder is taken. 1925 */ 1926 static inline unsigned long wait_table_bits(unsigned long size) 1927 { 1928 return ffz(~size); 1929 } 1930 1931 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) 1932 1933 /* 1934 * Initially all pages are reserved - free ones are freed 1935 * up by free_all_bootmem() once the early boot process is 1936 * done. Non-atomic initialization, single-pass. 1937 */ 1938 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 1939 unsigned long start_pfn, enum memmap_context context) 1940 { 1941 struct page *page; 1942 unsigned long end_pfn = start_pfn + size; 1943 unsigned long pfn; 1944 1945 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1946 /* 1947 * There can be holes in boot-time mem_map[]s 1948 * handed to this function. They do not 1949 * exist on hotplugged memory. 1950 */ 1951 if (context == MEMMAP_EARLY) { 1952 if (!early_pfn_valid(pfn)) 1953 continue; 1954 if (!early_pfn_in_nid(pfn, nid)) 1955 continue; 1956 } 1957 page = pfn_to_page(pfn); 1958 set_page_links(page, zone, nid, pfn); 1959 init_page_count(page); 1960 reset_page_mapcount(page); 1961 SetPageReserved(page); 1962 INIT_LIST_HEAD(&page->lru); 1963 #ifdef WANT_PAGE_VIRTUAL 1964 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 1965 if (!is_highmem_idx(zone)) 1966 set_page_address(page, __va(pfn << PAGE_SHIFT)); 1967 #endif 1968 } 1969 } 1970 1971 void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone, 1972 unsigned long size) 1973 { 1974 int order; 1975 for (order = 0; order < MAX_ORDER ; order++) { 1976 INIT_LIST_HEAD(&zone->free_area[order].free_list); 1977 zone->free_area[order].nr_free = 0; 1978 } 1979 } 1980 1981 #ifndef __HAVE_ARCH_MEMMAP_INIT 1982 #define memmap_init(size, nid, zone, start_pfn) \ 1983 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) 1984 #endif 1985 1986 static int __cpuinit zone_batchsize(struct zone *zone) 1987 { 1988 int batch; 1989 1990 /* 1991 * The per-cpu-pages pools are set to around 1000th of the 1992 * size of the zone. But no more than 1/2 of a meg. 1993 * 1994 * OK, so we don't know how big the cache is. So guess. 1995 */ 1996 batch = zone->present_pages / 1024; 1997 if (batch * PAGE_SIZE > 512 * 1024) 1998 batch = (512 * 1024) / PAGE_SIZE; 1999 batch /= 4; /* We effectively *= 4 below */ 2000 if (batch < 1) 2001 batch = 1; 2002 2003 /* 2004 * Clamp the batch to a 2^n - 1 value. Having a power 2005 * of 2 value was found to be more likely to have 2006 * suboptimal cache aliasing properties in some cases. 2007 * 2008 * For example if 2 tasks are alternately allocating 2009 * batches of pages, one task can end up with a lot 2010 * of pages of one half of the possible page colors 2011 * and the other with pages of the other colors. 2012 */ 2013 batch = (1 << (fls(batch + batch/2)-1)) - 1; 2014 2015 return batch; 2016 } 2017 2018 inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 2019 { 2020 struct per_cpu_pages *pcp; 2021 2022 memset(p, 0, sizeof(*p)); 2023 2024 pcp = &p->pcp[0]; /* hot */ 2025 pcp->count = 0; 2026 pcp->high = 6 * batch; 2027 pcp->batch = max(1UL, 1 * batch); 2028 INIT_LIST_HEAD(&pcp->list); 2029 2030 pcp = &p->pcp[1]; /* cold*/ 2031 pcp->count = 0; 2032 pcp->high = 2 * batch; 2033 pcp->batch = max(1UL, batch/2); 2034 INIT_LIST_HEAD(&pcp->list); 2035 } 2036 2037 /* 2038 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist 2039 * to the value high for the pageset p. 2040 */ 2041 2042 static void setup_pagelist_highmark(struct per_cpu_pageset *p, 2043 unsigned long high) 2044 { 2045 struct per_cpu_pages *pcp; 2046 2047 pcp = &p->pcp[0]; /* hot list */ 2048 pcp->high = high; 2049 pcp->batch = max(1UL, high/4); 2050 if ((high/4) > (PAGE_SHIFT * 8)) 2051 pcp->batch = PAGE_SHIFT * 8; 2052 } 2053 2054 2055 #ifdef CONFIG_NUMA 2056 /* 2057 * Boot pageset table. One per cpu which is going to be used for all 2058 * zones and all nodes. The parameters will be set in such a way 2059 * that an item put on a list will immediately be handed over to 2060 * the buddy list. This is safe since pageset manipulation is done 2061 * with interrupts disabled. 2062 * 2063 * Some NUMA counter updates may also be caught by the boot pagesets. 2064 * 2065 * The boot_pagesets must be kept even after bootup is complete for 2066 * unused processors and/or zones. They do play a role for bootstrapping 2067 * hotplugged processors. 2068 * 2069 * zoneinfo_show() and maybe other functions do 2070 * not check if the processor is online before following the pageset pointer. 2071 * Other parts of the kernel may not check if the zone is available. 2072 */ 2073 static struct per_cpu_pageset boot_pageset[NR_CPUS]; 2074 2075 /* 2076 * Dynamically allocate memory for the 2077 * per cpu pageset array in struct zone. 2078 */ 2079 static int __cpuinit process_zones(int cpu) 2080 { 2081 struct zone *zone, *dzone; 2082 2083 for_each_zone(zone) { 2084 2085 if (!populated_zone(zone)) 2086 continue; 2087 2088 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset), 2089 GFP_KERNEL, cpu_to_node(cpu)); 2090 if (!zone_pcp(zone, cpu)) 2091 goto bad; 2092 2093 setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone)); 2094 2095 if (percpu_pagelist_fraction) 2096 setup_pagelist_highmark(zone_pcp(zone, cpu), 2097 (zone->present_pages / percpu_pagelist_fraction)); 2098 } 2099 2100 return 0; 2101 bad: 2102 for_each_zone(dzone) { 2103 if (dzone == zone) 2104 break; 2105 kfree(zone_pcp(dzone, cpu)); 2106 zone_pcp(dzone, cpu) = NULL; 2107 } 2108 return -ENOMEM; 2109 } 2110 2111 static inline void free_zone_pagesets(int cpu) 2112 { 2113 struct zone *zone; 2114 2115 for_each_zone(zone) { 2116 struct per_cpu_pageset *pset = zone_pcp(zone, cpu); 2117 2118 /* Free per_cpu_pageset if it is slab allocated */ 2119 if (pset != &boot_pageset[cpu]) 2120 kfree(pset); 2121 zone_pcp(zone, cpu) = NULL; 2122 } 2123 } 2124 2125 static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb, 2126 unsigned long action, 2127 void *hcpu) 2128 { 2129 int cpu = (long)hcpu; 2130 int ret = NOTIFY_OK; 2131 2132 switch (action) { 2133 case CPU_UP_PREPARE: 2134 case CPU_UP_PREPARE_FROZEN: 2135 if (process_zones(cpu)) 2136 ret = NOTIFY_BAD; 2137 break; 2138 case CPU_UP_CANCELED: 2139 case CPU_UP_CANCELED_FROZEN: 2140 case CPU_DEAD: 2141 case CPU_DEAD_FROZEN: 2142 free_zone_pagesets(cpu); 2143 break; 2144 default: 2145 break; 2146 } 2147 return ret; 2148 } 2149 2150 static struct notifier_block __cpuinitdata pageset_notifier = 2151 { &pageset_cpuup_callback, NULL, 0 }; 2152 2153 void __init setup_per_cpu_pageset(void) 2154 { 2155 int err; 2156 2157 /* Initialize per_cpu_pageset for cpu 0. 2158 * A cpuup callback will do this for every cpu 2159 * as it comes online 2160 */ 2161 err = process_zones(smp_processor_id()); 2162 BUG_ON(err); 2163 register_cpu_notifier(&pageset_notifier); 2164 } 2165 2166 #endif 2167 2168 static __meminit noinline 2169 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 2170 { 2171 int i; 2172 struct pglist_data *pgdat = zone->zone_pgdat; 2173 size_t alloc_size; 2174 2175 /* 2176 * The per-page waitqueue mechanism uses hashed waitqueues 2177 * per zone. 2178 */ 2179 zone->wait_table_hash_nr_entries = 2180 wait_table_hash_nr_entries(zone_size_pages); 2181 zone->wait_table_bits = 2182 wait_table_bits(zone->wait_table_hash_nr_entries); 2183 alloc_size = zone->wait_table_hash_nr_entries 2184 * sizeof(wait_queue_head_t); 2185 2186 if (system_state == SYSTEM_BOOTING) { 2187 zone->wait_table = (wait_queue_head_t *) 2188 alloc_bootmem_node(pgdat, alloc_size); 2189 } else { 2190 /* 2191 * This case means that a zone whose size was 0 gets new memory 2192 * via memory hot-add. 2193 * But it may be the case that a new node was hot-added. In 2194 * this case vmalloc() will not be able to use this new node's 2195 * memory - this wait_table must be initialized to use this new 2196 * node itself as well. 2197 * To use this new node's memory, further consideration will be 2198 * necessary. 2199 */ 2200 zone->wait_table = (wait_queue_head_t *)vmalloc(alloc_size); 2201 } 2202 if (!zone->wait_table) 2203 return -ENOMEM; 2204 2205 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i) 2206 init_waitqueue_head(zone->wait_table + i); 2207 2208 return 0; 2209 } 2210 2211 static __meminit void zone_pcp_init(struct zone *zone) 2212 { 2213 int cpu; 2214 unsigned long batch = zone_batchsize(zone); 2215 2216 for (cpu = 0; cpu < NR_CPUS; cpu++) { 2217 #ifdef CONFIG_NUMA 2218 /* Early boot. Slab allocator not functional yet */ 2219 zone_pcp(zone, cpu) = &boot_pageset[cpu]; 2220 setup_pageset(&boot_pageset[cpu],0); 2221 #else 2222 setup_pageset(zone_pcp(zone,cpu), batch); 2223 #endif 2224 } 2225 if (zone->present_pages) 2226 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", 2227 zone->name, zone->present_pages, batch); 2228 } 2229 2230 __meminit int init_currently_empty_zone(struct zone *zone, 2231 unsigned long zone_start_pfn, 2232 unsigned long size, 2233 enum memmap_context context) 2234 { 2235 struct pglist_data *pgdat = zone->zone_pgdat; 2236 int ret; 2237 ret = zone_wait_table_init(zone, size); 2238 if (ret) 2239 return ret; 2240 pgdat->nr_zones = zone_idx(zone) + 1; 2241 2242 zone->zone_start_pfn = zone_start_pfn; 2243 2244 memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn); 2245 2246 zone_init_free_lists(pgdat, zone, zone->spanned_pages); 2247 2248 return 0; 2249 } 2250 2251 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP 2252 /* 2253 * Basic iterator support. Return the first range of PFNs for a node 2254 * Note: nid == MAX_NUMNODES returns first region regardless of node 2255 */ 2256 static int __meminit first_active_region_index_in_nid(int nid) 2257 { 2258 int i; 2259 2260 for (i = 0; i < nr_nodemap_entries; i++) 2261 if (nid == MAX_NUMNODES || early_node_map[i].nid == nid) 2262 return i; 2263 2264 return -1; 2265 } 2266 2267 /* 2268 * Basic iterator support. Return the next active range of PFNs for a node 2269 * Note: nid == MAX_NUMNODES returns next region regardles of node 2270 */ 2271 static int __meminit next_active_region_index_in_nid(int index, int nid) 2272 { 2273 for (index = index + 1; index < nr_nodemap_entries; index++) 2274 if (nid == MAX_NUMNODES || early_node_map[index].nid == nid) 2275 return index; 2276 2277 return -1; 2278 } 2279 2280 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID 2281 /* 2282 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. 2283 * Architectures may implement their own version but if add_active_range() 2284 * was used and there are no special requirements, this is a convenient 2285 * alternative 2286 */ 2287 int __meminit early_pfn_to_nid(unsigned long pfn) 2288 { 2289 int i; 2290 2291 for (i = 0; i < nr_nodemap_entries; i++) { 2292 unsigned long start_pfn = early_node_map[i].start_pfn; 2293 unsigned long end_pfn = early_node_map[i].end_pfn; 2294 2295 if (start_pfn <= pfn && pfn < end_pfn) 2296 return early_node_map[i].nid; 2297 } 2298 2299 return 0; 2300 } 2301 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ 2302 2303 /* Basic iterator support to walk early_node_map[] */ 2304 #define for_each_active_range_index_in_nid(i, nid) \ 2305 for (i = first_active_region_index_in_nid(nid); i != -1; \ 2306 i = next_active_region_index_in_nid(i, nid)) 2307 2308 /** 2309 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range 2310 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. 2311 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node 2312 * 2313 * If an architecture guarantees that all ranges registered with 2314 * add_active_ranges() contain no holes and may be freed, this 2315 * this function may be used instead of calling free_bootmem() manually. 2316 */ 2317 void __init free_bootmem_with_active_regions(int nid, 2318 unsigned long max_low_pfn) 2319 { 2320 int i; 2321 2322 for_each_active_range_index_in_nid(i, nid) { 2323 unsigned long size_pages = 0; 2324 unsigned long end_pfn = early_node_map[i].end_pfn; 2325 2326 if (early_node_map[i].start_pfn >= max_low_pfn) 2327 continue; 2328 2329 if (end_pfn > max_low_pfn) 2330 end_pfn = max_low_pfn; 2331 2332 size_pages = end_pfn - early_node_map[i].start_pfn; 2333 free_bootmem_node(NODE_DATA(early_node_map[i].nid), 2334 PFN_PHYS(early_node_map[i].start_pfn), 2335 size_pages << PAGE_SHIFT); 2336 } 2337 } 2338 2339 /** 2340 * sparse_memory_present_with_active_regions - Call memory_present for each active range 2341 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. 2342 * 2343 * If an architecture guarantees that all ranges registered with 2344 * add_active_ranges() contain no holes and may be freed, this 2345 * function may be used instead of calling memory_present() manually. 2346 */ 2347 void __init sparse_memory_present_with_active_regions(int nid) 2348 { 2349 int i; 2350 2351 for_each_active_range_index_in_nid(i, nid) 2352 memory_present(early_node_map[i].nid, 2353 early_node_map[i].start_pfn, 2354 early_node_map[i].end_pfn); 2355 } 2356 2357 /** 2358 * push_node_boundaries - Push node boundaries to at least the requested boundary 2359 * @nid: The nid of the node to push the boundary for 2360 * @start_pfn: The start pfn of the node 2361 * @end_pfn: The end pfn of the node 2362 * 2363 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd 2364 * time. Specifically, on x86_64, SRAT will report ranges that can potentially 2365 * be hotplugged even though no physical memory exists. This function allows 2366 * an arch to push out the node boundaries so mem_map is allocated that can 2367 * be used later. 2368 */ 2369 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE 2370 void __init push_node_boundaries(unsigned int nid, 2371 unsigned long start_pfn, unsigned long end_pfn) 2372 { 2373 printk(KERN_DEBUG "Entering push_node_boundaries(%u, %lu, %lu)\n", 2374 nid, start_pfn, end_pfn); 2375 2376 /* Initialise the boundary for this node if necessary */ 2377 if (node_boundary_end_pfn[nid] == 0) 2378 node_boundary_start_pfn[nid] = -1UL; 2379 2380 /* Update the boundaries */ 2381 if (node_boundary_start_pfn[nid] > start_pfn) 2382 node_boundary_start_pfn[nid] = start_pfn; 2383 if (node_boundary_end_pfn[nid] < end_pfn) 2384 node_boundary_end_pfn[nid] = end_pfn; 2385 } 2386 2387 /* If necessary, push the node boundary out for reserve hotadd */ 2388 static void __init account_node_boundary(unsigned int nid, 2389 unsigned long *start_pfn, unsigned long *end_pfn) 2390 { 2391 printk(KERN_DEBUG "Entering account_node_boundary(%u, %lu, %lu)\n", 2392 nid, *start_pfn, *end_pfn); 2393 2394 /* Return if boundary information has not been provided */ 2395 if (node_boundary_end_pfn[nid] == 0) 2396 return; 2397 2398 /* Check the boundaries and update if necessary */ 2399 if (node_boundary_start_pfn[nid] < *start_pfn) 2400 *start_pfn = node_boundary_start_pfn[nid]; 2401 if (node_boundary_end_pfn[nid] > *end_pfn) 2402 *end_pfn = node_boundary_end_pfn[nid]; 2403 } 2404 #else 2405 void __init push_node_boundaries(unsigned int nid, 2406 unsigned long start_pfn, unsigned long end_pfn) {} 2407 2408 static void __init account_node_boundary(unsigned int nid, 2409 unsigned long *start_pfn, unsigned long *end_pfn) {} 2410 #endif 2411 2412 2413 /** 2414 * get_pfn_range_for_nid - Return the start and end page frames for a node 2415 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. 2416 * @start_pfn: Passed by reference. On return, it will have the node start_pfn. 2417 * @end_pfn: Passed by reference. On return, it will have the node end_pfn. 2418 * 2419 * It returns the start and end page frame of a node based on information 2420 * provided by an arch calling add_active_range(). If called for a node 2421 * with no available memory, a warning is printed and the start and end 2422 * PFNs will be 0. 2423 */ 2424 void __meminit get_pfn_range_for_nid(unsigned int nid, 2425 unsigned long *start_pfn, unsigned long *end_pfn) 2426 { 2427 int i; 2428 *start_pfn = -1UL; 2429 *end_pfn = 0; 2430 2431 for_each_active_range_index_in_nid(i, nid) { 2432 *start_pfn = min(*start_pfn, early_node_map[i].start_pfn); 2433 *end_pfn = max(*end_pfn, early_node_map[i].end_pfn); 2434 } 2435 2436 if (*start_pfn == -1UL) { 2437 printk(KERN_WARNING "Node %u active with no memory\n", nid); 2438 *start_pfn = 0; 2439 } 2440 2441 /* Push the node boundaries out if requested */ 2442 account_node_boundary(nid, start_pfn, end_pfn); 2443 } 2444 2445 /* 2446 * Return the number of pages a zone spans in a node, including holes 2447 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() 2448 */ 2449 unsigned long __meminit zone_spanned_pages_in_node(int nid, 2450 unsigned long zone_type, 2451 unsigned long *ignored) 2452 { 2453 unsigned long node_start_pfn, node_end_pfn; 2454 unsigned long zone_start_pfn, zone_end_pfn; 2455 2456 /* Get the start and end of the node and zone */ 2457 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 2458 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; 2459 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; 2460 2461 /* Check that this node has pages within the zone's required range */ 2462 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) 2463 return 0; 2464 2465 /* Move the zone boundaries inside the node if necessary */ 2466 zone_end_pfn = min(zone_end_pfn, node_end_pfn); 2467 zone_start_pfn = max(zone_start_pfn, node_start_pfn); 2468 2469 /* Return the spanned pages */ 2470 return zone_end_pfn - zone_start_pfn; 2471 } 2472 2473 /* 2474 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, 2475 * then all holes in the requested range will be accounted for. 2476 */ 2477 unsigned long __meminit __absent_pages_in_range(int nid, 2478 unsigned long range_start_pfn, 2479 unsigned long range_end_pfn) 2480 { 2481 int i = 0; 2482 unsigned long prev_end_pfn = 0, hole_pages = 0; 2483 unsigned long start_pfn; 2484 2485 /* Find the end_pfn of the first active range of pfns in the node */ 2486 i = first_active_region_index_in_nid(nid); 2487 if (i == -1) 2488 return 0; 2489 2490 /* Account for ranges before physical memory on this node */ 2491 if (early_node_map[i].start_pfn > range_start_pfn) 2492 hole_pages = early_node_map[i].start_pfn - range_start_pfn; 2493 2494 prev_end_pfn = early_node_map[i].start_pfn; 2495 2496 /* Find all holes for the zone within the node */ 2497 for (; i != -1; i = next_active_region_index_in_nid(i, nid)) { 2498 2499 /* No need to continue if prev_end_pfn is outside the zone */ 2500 if (prev_end_pfn >= range_end_pfn) 2501 break; 2502 2503 /* Make sure the end of the zone is not within the hole */ 2504 start_pfn = min(early_node_map[i].start_pfn, range_end_pfn); 2505 prev_end_pfn = max(prev_end_pfn, range_start_pfn); 2506 2507 /* Update the hole size cound and move on */ 2508 if (start_pfn > range_start_pfn) { 2509 BUG_ON(prev_end_pfn > start_pfn); 2510 hole_pages += start_pfn - prev_end_pfn; 2511 } 2512 prev_end_pfn = early_node_map[i].end_pfn; 2513 } 2514 2515 /* Account for ranges past physical memory on this node */ 2516 if (range_end_pfn > prev_end_pfn) 2517 hole_pages += range_end_pfn - 2518 max(range_start_pfn, prev_end_pfn); 2519 2520 return hole_pages; 2521 } 2522 2523 /** 2524 * absent_pages_in_range - Return number of page frames in holes within a range 2525 * @start_pfn: The start PFN to start searching for holes 2526 * @end_pfn: The end PFN to stop searching for holes 2527 * 2528 * It returns the number of pages frames in memory holes within a range. 2529 */ 2530 unsigned long __init absent_pages_in_range(unsigned long start_pfn, 2531 unsigned long end_pfn) 2532 { 2533 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); 2534 } 2535 2536 /* Return the number of page frames in holes in a zone on a node */ 2537 unsigned long __meminit zone_absent_pages_in_node(int nid, 2538 unsigned long zone_type, 2539 unsigned long *ignored) 2540 { 2541 unsigned long node_start_pfn, node_end_pfn; 2542 unsigned long zone_start_pfn, zone_end_pfn; 2543 2544 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 2545 zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type], 2546 node_start_pfn); 2547 zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type], 2548 node_end_pfn); 2549 2550 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); 2551 } 2552 2553 #else 2554 static inline unsigned long zone_spanned_pages_in_node(int nid, 2555 unsigned long zone_type, 2556 unsigned long *zones_size) 2557 { 2558 return zones_size[zone_type]; 2559 } 2560 2561 static inline unsigned long zone_absent_pages_in_node(int nid, 2562 unsigned long zone_type, 2563 unsigned long *zholes_size) 2564 { 2565 if (!zholes_size) 2566 return 0; 2567 2568 return zholes_size[zone_type]; 2569 } 2570 2571 #endif 2572 2573 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, 2574 unsigned long *zones_size, unsigned long *zholes_size) 2575 { 2576 unsigned long realtotalpages, totalpages = 0; 2577 enum zone_type i; 2578 2579 for (i = 0; i < MAX_NR_ZONES; i++) 2580 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i, 2581 zones_size); 2582 pgdat->node_spanned_pages = totalpages; 2583 2584 realtotalpages = totalpages; 2585 for (i = 0; i < MAX_NR_ZONES; i++) 2586 realtotalpages -= 2587 zone_absent_pages_in_node(pgdat->node_id, i, 2588 zholes_size); 2589 pgdat->node_present_pages = realtotalpages; 2590 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, 2591 realtotalpages); 2592 } 2593 2594 /* 2595 * Set up the zone data structures: 2596 * - mark all pages reserved 2597 * - mark all memory queues empty 2598 * - clear the memory bitmaps 2599 */ 2600 static void __meminit free_area_init_core(struct pglist_data *pgdat, 2601 unsigned long *zones_size, unsigned long *zholes_size) 2602 { 2603 enum zone_type j; 2604 int nid = pgdat->node_id; 2605 unsigned long zone_start_pfn = pgdat->node_start_pfn; 2606 int ret; 2607 2608 pgdat_resize_init(pgdat); 2609 pgdat->nr_zones = 0; 2610 init_waitqueue_head(&pgdat->kswapd_wait); 2611 pgdat->kswapd_max_order = 0; 2612 2613 for (j = 0; j < MAX_NR_ZONES; j++) { 2614 struct zone *zone = pgdat->node_zones + j; 2615 unsigned long size, realsize, memmap_pages; 2616 2617 size = zone_spanned_pages_in_node(nid, j, zones_size); 2618 realsize = size - zone_absent_pages_in_node(nid, j, 2619 zholes_size); 2620 2621 /* 2622 * Adjust realsize so that it accounts for how much memory 2623 * is used by this zone for memmap. This affects the watermark 2624 * and per-cpu initialisations 2625 */ 2626 memmap_pages = (size * sizeof(struct page)) >> PAGE_SHIFT; 2627 if (realsize >= memmap_pages) { 2628 realsize -= memmap_pages; 2629 printk(KERN_DEBUG 2630 " %s zone: %lu pages used for memmap\n", 2631 zone_names[j], memmap_pages); 2632 } else 2633 printk(KERN_WARNING 2634 " %s zone: %lu pages exceeds realsize %lu\n", 2635 zone_names[j], memmap_pages, realsize); 2636 2637 /* Account for reserved pages */ 2638 if (j == 0 && realsize > dma_reserve) { 2639 realsize -= dma_reserve; 2640 printk(KERN_DEBUG " %s zone: %lu pages reserved\n", 2641 zone_names[0], dma_reserve); 2642 } 2643 2644 if (!is_highmem_idx(j)) 2645 nr_kernel_pages += realsize; 2646 nr_all_pages += realsize; 2647 2648 zone->spanned_pages = size; 2649 zone->present_pages = realsize; 2650 #ifdef CONFIG_NUMA 2651 zone->node = nid; 2652 zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio) 2653 / 100; 2654 zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100; 2655 #endif 2656 zone->name = zone_names[j]; 2657 spin_lock_init(&zone->lock); 2658 spin_lock_init(&zone->lru_lock); 2659 zone_seqlock_init(zone); 2660 zone->zone_pgdat = pgdat; 2661 2662 zone->prev_priority = DEF_PRIORITY; 2663 2664 zone_pcp_init(zone); 2665 INIT_LIST_HEAD(&zone->active_list); 2666 INIT_LIST_HEAD(&zone->inactive_list); 2667 zone->nr_scan_active = 0; 2668 zone->nr_scan_inactive = 0; 2669 zap_zone_vm_stats(zone); 2670 atomic_set(&zone->reclaim_in_progress, 0); 2671 if (!size) 2672 continue; 2673 2674 ret = init_currently_empty_zone(zone, zone_start_pfn, 2675 size, MEMMAP_EARLY); 2676 BUG_ON(ret); 2677 zone_start_pfn += size; 2678 } 2679 } 2680 2681 static void __meminit alloc_node_mem_map(struct pglist_data *pgdat) 2682 { 2683 /* Skip empty nodes */ 2684 if (!pgdat->node_spanned_pages) 2685 return; 2686 2687 #ifdef CONFIG_FLAT_NODE_MEM_MAP 2688 /* ia64 gets its own node_mem_map, before this, without bootmem */ 2689 if (!pgdat->node_mem_map) { 2690 unsigned long size, start, end; 2691 struct page *map; 2692 2693 /* 2694 * The zone's endpoints aren't required to be MAX_ORDER 2695 * aligned but the node_mem_map endpoints must be in order 2696 * for the buddy allocator to function correctly. 2697 */ 2698 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); 2699 end = pgdat->node_start_pfn + pgdat->node_spanned_pages; 2700 end = ALIGN(end, MAX_ORDER_NR_PAGES); 2701 size = (end - start) * sizeof(struct page); 2702 map = alloc_remap(pgdat->node_id, size); 2703 if (!map) 2704 map = alloc_bootmem_node(pgdat, size); 2705 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); 2706 } 2707 #ifdef CONFIG_FLATMEM 2708 /* 2709 * With no DISCONTIG, the global mem_map is just set as node 0's 2710 */ 2711 if (pgdat == NODE_DATA(0)) { 2712 mem_map = NODE_DATA(0)->node_mem_map; 2713 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP 2714 if (page_to_pfn(mem_map) != pgdat->node_start_pfn) 2715 mem_map -= pgdat->node_start_pfn; 2716 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 2717 } 2718 #endif 2719 #endif /* CONFIG_FLAT_NODE_MEM_MAP */ 2720 } 2721 2722 void __meminit free_area_init_node(int nid, struct pglist_data *pgdat, 2723 unsigned long *zones_size, unsigned long node_start_pfn, 2724 unsigned long *zholes_size) 2725 { 2726 pgdat->node_id = nid; 2727 pgdat->node_start_pfn = node_start_pfn; 2728 calculate_node_totalpages(pgdat, zones_size, zholes_size); 2729 2730 alloc_node_mem_map(pgdat); 2731 2732 free_area_init_core(pgdat, zones_size, zholes_size); 2733 } 2734 2735 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP 2736 /** 2737 * add_active_range - Register a range of PFNs backed by physical memory 2738 * @nid: The node ID the range resides on 2739 * @start_pfn: The start PFN of the available physical memory 2740 * @end_pfn: The end PFN of the available physical memory 2741 * 2742 * These ranges are stored in an early_node_map[] and later used by 2743 * free_area_init_nodes() to calculate zone sizes and holes. If the 2744 * range spans a memory hole, it is up to the architecture to ensure 2745 * the memory is not freed by the bootmem allocator. If possible 2746 * the range being registered will be merged with existing ranges. 2747 */ 2748 void __init add_active_range(unsigned int nid, unsigned long start_pfn, 2749 unsigned long end_pfn) 2750 { 2751 int i; 2752 2753 printk(KERN_DEBUG "Entering add_active_range(%d, %lu, %lu) " 2754 "%d entries of %d used\n", 2755 nid, start_pfn, end_pfn, 2756 nr_nodemap_entries, MAX_ACTIVE_REGIONS); 2757 2758 /* Merge with existing active regions if possible */ 2759 for (i = 0; i < nr_nodemap_entries; i++) { 2760 if (early_node_map[i].nid != nid) 2761 continue; 2762 2763 /* Skip if an existing region covers this new one */ 2764 if (start_pfn >= early_node_map[i].start_pfn && 2765 end_pfn <= early_node_map[i].end_pfn) 2766 return; 2767 2768 /* Merge forward if suitable */ 2769 if (start_pfn <= early_node_map[i].end_pfn && 2770 end_pfn > early_node_map[i].end_pfn) { 2771 early_node_map[i].end_pfn = end_pfn; 2772 return; 2773 } 2774 2775 /* Merge backward if suitable */ 2776 if (start_pfn < early_node_map[i].end_pfn && 2777 end_pfn >= early_node_map[i].start_pfn) { 2778 early_node_map[i].start_pfn = start_pfn; 2779 return; 2780 } 2781 } 2782 2783 /* Check that early_node_map is large enough */ 2784 if (i >= MAX_ACTIVE_REGIONS) { 2785 printk(KERN_CRIT "More than %d memory regions, truncating\n", 2786 MAX_ACTIVE_REGIONS); 2787 return; 2788 } 2789 2790 early_node_map[i].nid = nid; 2791 early_node_map[i].start_pfn = start_pfn; 2792 early_node_map[i].end_pfn = end_pfn; 2793 nr_nodemap_entries = i + 1; 2794 } 2795 2796 /** 2797 * shrink_active_range - Shrink an existing registered range of PFNs 2798 * @nid: The node id the range is on that should be shrunk 2799 * @old_end_pfn: The old end PFN of the range 2800 * @new_end_pfn: The new PFN of the range 2801 * 2802 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node. 2803 * The map is kept at the end physical page range that has already been 2804 * registered with add_active_range(). This function allows an arch to shrink 2805 * an existing registered range. 2806 */ 2807 void __init shrink_active_range(unsigned int nid, unsigned long old_end_pfn, 2808 unsigned long new_end_pfn) 2809 { 2810 int i; 2811 2812 /* Find the old active region end and shrink */ 2813 for_each_active_range_index_in_nid(i, nid) 2814 if (early_node_map[i].end_pfn == old_end_pfn) { 2815 early_node_map[i].end_pfn = new_end_pfn; 2816 break; 2817 } 2818 } 2819 2820 /** 2821 * remove_all_active_ranges - Remove all currently registered regions 2822 * 2823 * During discovery, it may be found that a table like SRAT is invalid 2824 * and an alternative discovery method must be used. This function removes 2825 * all currently registered regions. 2826 */ 2827 void __init remove_all_active_ranges(void) 2828 { 2829 memset(early_node_map, 0, sizeof(early_node_map)); 2830 nr_nodemap_entries = 0; 2831 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE 2832 memset(node_boundary_start_pfn, 0, sizeof(node_boundary_start_pfn)); 2833 memset(node_boundary_end_pfn, 0, sizeof(node_boundary_end_pfn)); 2834 #endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */ 2835 } 2836 2837 /* Compare two active node_active_regions */ 2838 static int __init cmp_node_active_region(const void *a, const void *b) 2839 { 2840 struct node_active_region *arange = (struct node_active_region *)a; 2841 struct node_active_region *brange = (struct node_active_region *)b; 2842 2843 /* Done this way to avoid overflows */ 2844 if (arange->start_pfn > brange->start_pfn) 2845 return 1; 2846 if (arange->start_pfn < brange->start_pfn) 2847 return -1; 2848 2849 return 0; 2850 } 2851 2852 /* sort the node_map by start_pfn */ 2853 static void __init sort_node_map(void) 2854 { 2855 sort(early_node_map, (size_t)nr_nodemap_entries, 2856 sizeof(struct node_active_region), 2857 cmp_node_active_region, NULL); 2858 } 2859 2860 /* Find the lowest pfn for a node */ 2861 unsigned long __init find_min_pfn_for_node(unsigned long nid) 2862 { 2863 int i; 2864 unsigned long min_pfn = ULONG_MAX; 2865 2866 /* Assuming a sorted map, the first range found has the starting pfn */ 2867 for_each_active_range_index_in_nid(i, nid) 2868 min_pfn = min(min_pfn, early_node_map[i].start_pfn); 2869 2870 if (min_pfn == ULONG_MAX) { 2871 printk(KERN_WARNING 2872 "Could not find start_pfn for node %lu\n", nid); 2873 return 0; 2874 } 2875 2876 return min_pfn; 2877 } 2878 2879 /** 2880 * find_min_pfn_with_active_regions - Find the minimum PFN registered 2881 * 2882 * It returns the minimum PFN based on information provided via 2883 * add_active_range(). 2884 */ 2885 unsigned long __init find_min_pfn_with_active_regions(void) 2886 { 2887 return find_min_pfn_for_node(MAX_NUMNODES); 2888 } 2889 2890 /** 2891 * find_max_pfn_with_active_regions - Find the maximum PFN registered 2892 * 2893 * It returns the maximum PFN based on information provided via 2894 * add_active_range(). 2895 */ 2896 unsigned long __init find_max_pfn_with_active_regions(void) 2897 { 2898 int i; 2899 unsigned long max_pfn = 0; 2900 2901 for (i = 0; i < nr_nodemap_entries; i++) 2902 max_pfn = max(max_pfn, early_node_map[i].end_pfn); 2903 2904 return max_pfn; 2905 } 2906 2907 /** 2908 * free_area_init_nodes - Initialise all pg_data_t and zone data 2909 * @max_zone_pfn: an array of max PFNs for each zone 2910 * 2911 * This will call free_area_init_node() for each active node in the system. 2912 * Using the page ranges provided by add_active_range(), the size of each 2913 * zone in each node and their holes is calculated. If the maximum PFN 2914 * between two adjacent zones match, it is assumed that the zone is empty. 2915 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed 2916 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone 2917 * starts where the previous one ended. For example, ZONE_DMA32 starts 2918 * at arch_max_dma_pfn. 2919 */ 2920 void __init free_area_init_nodes(unsigned long *max_zone_pfn) 2921 { 2922 unsigned long nid; 2923 enum zone_type i; 2924 2925 /* Sort early_node_map as initialisation assumes it is sorted */ 2926 sort_node_map(); 2927 2928 /* Record where the zone boundaries are */ 2929 memset(arch_zone_lowest_possible_pfn, 0, 2930 sizeof(arch_zone_lowest_possible_pfn)); 2931 memset(arch_zone_highest_possible_pfn, 0, 2932 sizeof(arch_zone_highest_possible_pfn)); 2933 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); 2934 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; 2935 for (i = 1; i < MAX_NR_ZONES; i++) { 2936 arch_zone_lowest_possible_pfn[i] = 2937 arch_zone_highest_possible_pfn[i-1]; 2938 arch_zone_highest_possible_pfn[i] = 2939 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); 2940 } 2941 2942 /* Print out the zone ranges */ 2943 printk("Zone PFN ranges:\n"); 2944 for (i = 0; i < MAX_NR_ZONES; i++) 2945 printk(" %-8s %8lu -> %8lu\n", 2946 zone_names[i], 2947 arch_zone_lowest_possible_pfn[i], 2948 arch_zone_highest_possible_pfn[i]); 2949 2950 /* Print out the early_node_map[] */ 2951 printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries); 2952 for (i = 0; i < nr_nodemap_entries; i++) 2953 printk(" %3d: %8lu -> %8lu\n", early_node_map[i].nid, 2954 early_node_map[i].start_pfn, 2955 early_node_map[i].end_pfn); 2956 2957 /* Initialise every node */ 2958 setup_nr_node_ids(); 2959 for_each_online_node(nid) { 2960 pg_data_t *pgdat = NODE_DATA(nid); 2961 free_area_init_node(nid, pgdat, NULL, 2962 find_min_pfn_for_node(nid), NULL); 2963 } 2964 } 2965 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */ 2966 2967 /** 2968 * set_dma_reserve - set the specified number of pages reserved in the first zone 2969 * @new_dma_reserve: The number of pages to mark reserved 2970 * 2971 * The per-cpu batchsize and zone watermarks are determined by present_pages. 2972 * In the DMA zone, a significant percentage may be consumed by kernel image 2973 * and other unfreeable allocations which can skew the watermarks badly. This 2974 * function may optionally be used to account for unfreeable pages in the 2975 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and 2976 * smaller per-cpu batchsize. 2977 */ 2978 void __init set_dma_reserve(unsigned long new_dma_reserve) 2979 { 2980 dma_reserve = new_dma_reserve; 2981 } 2982 2983 #ifndef CONFIG_NEED_MULTIPLE_NODES 2984 static bootmem_data_t contig_bootmem_data; 2985 struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data }; 2986 2987 EXPORT_SYMBOL(contig_page_data); 2988 #endif 2989 2990 void __init free_area_init(unsigned long *zones_size) 2991 { 2992 free_area_init_node(0, NODE_DATA(0), zones_size, 2993 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 2994 } 2995 2996 static int page_alloc_cpu_notify(struct notifier_block *self, 2997 unsigned long action, void *hcpu) 2998 { 2999 int cpu = (unsigned long)hcpu; 3000 3001 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { 3002 local_irq_disable(); 3003 __drain_pages(cpu); 3004 vm_events_fold_cpu(cpu); 3005 local_irq_enable(); 3006 refresh_cpu_vm_stats(cpu); 3007 } 3008 return NOTIFY_OK; 3009 } 3010 3011 void __init page_alloc_init(void) 3012 { 3013 hotcpu_notifier(page_alloc_cpu_notify, 0); 3014 } 3015 3016 /* 3017 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio 3018 * or min_free_kbytes changes. 3019 */ 3020 static void calculate_totalreserve_pages(void) 3021 { 3022 struct pglist_data *pgdat; 3023 unsigned long reserve_pages = 0; 3024 enum zone_type i, j; 3025 3026 for_each_online_pgdat(pgdat) { 3027 for (i = 0; i < MAX_NR_ZONES; i++) { 3028 struct zone *zone = pgdat->node_zones + i; 3029 unsigned long max = 0; 3030 3031 /* Find valid and maximum lowmem_reserve in the zone */ 3032 for (j = i; j < MAX_NR_ZONES; j++) { 3033 if (zone->lowmem_reserve[j] > max) 3034 max = zone->lowmem_reserve[j]; 3035 } 3036 3037 /* we treat pages_high as reserved pages. */ 3038 max += zone->pages_high; 3039 3040 if (max > zone->present_pages) 3041 max = zone->present_pages; 3042 reserve_pages += max; 3043 } 3044 } 3045 totalreserve_pages = reserve_pages; 3046 } 3047 3048 /* 3049 * setup_per_zone_lowmem_reserve - called whenever 3050 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 3051 * has a correct pages reserved value, so an adequate number of 3052 * pages are left in the zone after a successful __alloc_pages(). 3053 */ 3054 static void setup_per_zone_lowmem_reserve(void) 3055 { 3056 struct pglist_data *pgdat; 3057 enum zone_type j, idx; 3058 3059 for_each_online_pgdat(pgdat) { 3060 for (j = 0; j < MAX_NR_ZONES; j++) { 3061 struct zone *zone = pgdat->node_zones + j; 3062 unsigned long present_pages = zone->present_pages; 3063 3064 zone->lowmem_reserve[j] = 0; 3065 3066 idx = j; 3067 while (idx) { 3068 struct zone *lower_zone; 3069 3070 idx--; 3071 3072 if (sysctl_lowmem_reserve_ratio[idx] < 1) 3073 sysctl_lowmem_reserve_ratio[idx] = 1; 3074 3075 lower_zone = pgdat->node_zones + idx; 3076 lower_zone->lowmem_reserve[j] = present_pages / 3077 sysctl_lowmem_reserve_ratio[idx]; 3078 present_pages += lower_zone->present_pages; 3079 } 3080 } 3081 } 3082 3083 /* update totalreserve_pages */ 3084 calculate_totalreserve_pages(); 3085 } 3086 3087 /** 3088 * setup_per_zone_pages_min - called when min_free_kbytes changes. 3089 * 3090 * Ensures that the pages_{min,low,high} values for each zone are set correctly 3091 * with respect to min_free_kbytes. 3092 */ 3093 void setup_per_zone_pages_min(void) 3094 { 3095 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 3096 unsigned long lowmem_pages = 0; 3097 struct zone *zone; 3098 unsigned long flags; 3099 3100 /* Calculate total number of !ZONE_HIGHMEM pages */ 3101 for_each_zone(zone) { 3102 if (!is_highmem(zone)) 3103 lowmem_pages += zone->present_pages; 3104 } 3105 3106 for_each_zone(zone) { 3107 u64 tmp; 3108 3109 spin_lock_irqsave(&zone->lru_lock, flags); 3110 tmp = (u64)pages_min * zone->present_pages; 3111 do_div(tmp, lowmem_pages); 3112 if (is_highmem(zone)) { 3113 /* 3114 * __GFP_HIGH and PF_MEMALLOC allocations usually don't 3115 * need highmem pages, so cap pages_min to a small 3116 * value here. 3117 * 3118 * The (pages_high-pages_low) and (pages_low-pages_min) 3119 * deltas controls asynch page reclaim, and so should 3120 * not be capped for highmem. 3121 */ 3122 int min_pages; 3123 3124 min_pages = zone->present_pages / 1024; 3125 if (min_pages < SWAP_CLUSTER_MAX) 3126 min_pages = SWAP_CLUSTER_MAX; 3127 if (min_pages > 128) 3128 min_pages = 128; 3129 zone->pages_min = min_pages; 3130 } else { 3131 /* 3132 * If it's a lowmem zone, reserve a number of pages 3133 * proportionate to the zone's size. 3134 */ 3135 zone->pages_min = tmp; 3136 } 3137 3138 zone->pages_low = zone->pages_min + (tmp >> 2); 3139 zone->pages_high = zone->pages_min + (tmp >> 1); 3140 spin_unlock_irqrestore(&zone->lru_lock, flags); 3141 } 3142 3143 /* update totalreserve_pages */ 3144 calculate_totalreserve_pages(); 3145 } 3146 3147 /* 3148 * Initialise min_free_kbytes. 3149 * 3150 * For small machines we want it small (128k min). For large machines 3151 * we want it large (64MB max). But it is not linear, because network 3152 * bandwidth does not increase linearly with machine size. We use 3153 * 3154 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 3155 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 3156 * 3157 * which yields 3158 * 3159 * 16MB: 512k 3160 * 32MB: 724k 3161 * 64MB: 1024k 3162 * 128MB: 1448k 3163 * 256MB: 2048k 3164 * 512MB: 2896k 3165 * 1024MB: 4096k 3166 * 2048MB: 5792k 3167 * 4096MB: 8192k 3168 * 8192MB: 11584k 3169 * 16384MB: 16384k 3170 */ 3171 static int __init init_per_zone_pages_min(void) 3172 { 3173 unsigned long lowmem_kbytes; 3174 3175 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 3176 3177 min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 3178 if (min_free_kbytes < 128) 3179 min_free_kbytes = 128; 3180 if (min_free_kbytes > 65536) 3181 min_free_kbytes = 65536; 3182 setup_per_zone_pages_min(); 3183 setup_per_zone_lowmem_reserve(); 3184 return 0; 3185 } 3186 module_init(init_per_zone_pages_min) 3187 3188 /* 3189 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 3190 * that we can call two helper functions whenever min_free_kbytes 3191 * changes. 3192 */ 3193 int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 3194 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 3195 { 3196 proc_dointvec(table, write, file, buffer, length, ppos); 3197 if (write) 3198 setup_per_zone_pages_min(); 3199 return 0; 3200 } 3201 3202 #ifdef CONFIG_NUMA 3203 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, 3204 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 3205 { 3206 struct zone *zone; 3207 int rc; 3208 3209 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 3210 if (rc) 3211 return rc; 3212 3213 for_each_zone(zone) 3214 zone->min_unmapped_pages = (zone->present_pages * 3215 sysctl_min_unmapped_ratio) / 100; 3216 return 0; 3217 } 3218 3219 int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write, 3220 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 3221 { 3222 struct zone *zone; 3223 int rc; 3224 3225 rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 3226 if (rc) 3227 return rc; 3228 3229 for_each_zone(zone) 3230 zone->min_slab_pages = (zone->present_pages * 3231 sysctl_min_slab_ratio) / 100; 3232 return 0; 3233 } 3234 #endif 3235 3236 /* 3237 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 3238 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 3239 * whenever sysctl_lowmem_reserve_ratio changes. 3240 * 3241 * The reserve ratio obviously has absolutely no relation with the 3242 * pages_min watermarks. The lowmem reserve ratio can only make sense 3243 * if in function of the boot time zone sizes. 3244 */ 3245 int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, 3246 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 3247 { 3248 proc_dointvec_minmax(table, write, file, buffer, length, ppos); 3249 setup_per_zone_lowmem_reserve(); 3250 return 0; 3251 } 3252 3253 /* 3254 * percpu_pagelist_fraction - changes the pcp->high for each zone on each 3255 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist 3256 * can have before it gets flushed back to buddy allocator. 3257 */ 3258 3259 int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, 3260 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 3261 { 3262 struct zone *zone; 3263 unsigned int cpu; 3264 int ret; 3265 3266 ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos); 3267 if (!write || (ret == -EINVAL)) 3268 return ret; 3269 for_each_zone(zone) { 3270 for_each_online_cpu(cpu) { 3271 unsigned long high; 3272 high = zone->present_pages / percpu_pagelist_fraction; 3273 setup_pagelist_highmark(zone_pcp(zone, cpu), high); 3274 } 3275 } 3276 return 0; 3277 } 3278 3279 int hashdist = HASHDIST_DEFAULT; 3280 3281 #ifdef CONFIG_NUMA 3282 static int __init set_hashdist(char *str) 3283 { 3284 if (!str) 3285 return 0; 3286 hashdist = simple_strtoul(str, &str, 0); 3287 return 1; 3288 } 3289 __setup("hashdist=", set_hashdist); 3290 #endif 3291 3292 /* 3293 * allocate a large system hash table from bootmem 3294 * - it is assumed that the hash table must contain an exact power-of-2 3295 * quantity of entries 3296 * - limit is the number of hash buckets, not the total allocation size 3297 */ 3298 void *__init alloc_large_system_hash(const char *tablename, 3299 unsigned long bucketsize, 3300 unsigned long numentries, 3301 int scale, 3302 int flags, 3303 unsigned int *_hash_shift, 3304 unsigned int *_hash_mask, 3305 unsigned long limit) 3306 { 3307 unsigned long long max = limit; 3308 unsigned long log2qty, size; 3309 void *table = NULL; 3310 3311 /* allow the kernel cmdline to have a say */ 3312 if (!numentries) { 3313 /* round applicable memory size up to nearest megabyte */ 3314 numentries = nr_kernel_pages; 3315 numentries += (1UL << (20 - PAGE_SHIFT)) - 1; 3316 numentries >>= 20 - PAGE_SHIFT; 3317 numentries <<= 20 - PAGE_SHIFT; 3318 3319 /* limit to 1 bucket per 2^scale bytes of low memory */ 3320 if (scale > PAGE_SHIFT) 3321 numentries >>= (scale - PAGE_SHIFT); 3322 else 3323 numentries <<= (PAGE_SHIFT - scale); 3324 3325 /* Make sure we've got at least a 0-order allocation.. */ 3326 if (unlikely((numentries * bucketsize) < PAGE_SIZE)) 3327 numentries = PAGE_SIZE / bucketsize; 3328 } 3329 numentries = roundup_pow_of_two(numentries); 3330 3331 /* limit allocation size to 1/16 total memory by default */ 3332 if (max == 0) { 3333 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 3334 do_div(max, bucketsize); 3335 } 3336 3337 if (numentries > max) 3338 numentries = max; 3339 3340 log2qty = ilog2(numentries); 3341 3342 do { 3343 size = bucketsize << log2qty; 3344 if (flags & HASH_EARLY) 3345 table = alloc_bootmem(size); 3346 else if (hashdist) 3347 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 3348 else { 3349 unsigned long order; 3350 for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++) 3351 ; 3352 table = (void*) __get_free_pages(GFP_ATOMIC, order); 3353 } 3354 } while (!table && size > PAGE_SIZE && --log2qty); 3355 3356 if (!table) 3357 panic("Failed to allocate %s hash table\n", tablename); 3358 3359 printk("%s hash table entries: %d (order: %d, %lu bytes)\n", 3360 tablename, 3361 (1U << log2qty), 3362 ilog2(size) - PAGE_SHIFT, 3363 size); 3364 3365 if (_hash_shift) 3366 *_hash_shift = log2qty; 3367 if (_hash_mask) 3368 *_hash_mask = (1 << log2qty) - 1; 3369 3370 return table; 3371 } 3372 3373 #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE 3374 struct page *pfn_to_page(unsigned long pfn) 3375 { 3376 return __pfn_to_page(pfn); 3377 } 3378 unsigned long page_to_pfn(struct page *page) 3379 { 3380 return __page_to_pfn(page); 3381 } 3382 EXPORT_SYMBOL(pfn_to_page); 3383 EXPORT_SYMBOL(page_to_pfn); 3384 #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */ 3385 3386 3387