1 /* 2 * linux/mm/page_alloc.c 3 * 4 * Manages the free list, the system allocates free pages here. 5 * Note that kmalloc() lives in slab.c 6 * 7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 8 * Swap reorganised 29.12.95, Stephen Tweedie 9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999 11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999 12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000 13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002 14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton) 15 */ 16 17 #include <linux/config.h> 18 #include <linux/stddef.h> 19 #include <linux/mm.h> 20 #include <linux/swap.h> 21 #include <linux/interrupt.h> 22 #include <linux/pagemap.h> 23 #include <linux/bootmem.h> 24 #include <linux/compiler.h> 25 #include <linux/kernel.h> 26 #include <linux/module.h> 27 #include <linux/suspend.h> 28 #include <linux/pagevec.h> 29 #include <linux/blkdev.h> 30 #include <linux/slab.h> 31 #include <linux/notifier.h> 32 #include <linux/topology.h> 33 #include <linux/sysctl.h> 34 #include <linux/cpu.h> 35 #include <linux/cpuset.h> 36 #include <linux/memory_hotplug.h> 37 #include <linux/nodemask.h> 38 #include <linux/vmalloc.h> 39 40 #include <asm/tlbflush.h> 41 #include "internal.h" 42 43 /* 44 * MCD - HACK: Find somewhere to initialize this EARLY, or make this 45 * initializer cleaner 46 */ 47 nodemask_t node_online_map __read_mostly = { { [0] = 1UL } }; 48 EXPORT_SYMBOL(node_online_map); 49 nodemask_t node_possible_map __read_mostly = NODE_MASK_ALL; 50 EXPORT_SYMBOL(node_possible_map); 51 struct pglist_data *pgdat_list __read_mostly; 52 unsigned long totalram_pages __read_mostly; 53 unsigned long totalhigh_pages __read_mostly; 54 long nr_swap_pages; 55 56 /* 57 * results with 256, 32 in the lowmem_reserve sysctl: 58 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) 59 * 1G machine -> (16M dma, 784M normal, 224M high) 60 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA 61 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL 62 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA 63 */ 64 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 256, 32 }; 65 66 EXPORT_SYMBOL(totalram_pages); 67 EXPORT_SYMBOL(nr_swap_pages); 68 69 /* 70 * Used by page_zone() to look up the address of the struct zone whose 71 * id is encoded in the upper bits of page->flags 72 */ 73 struct zone *zone_table[1 << ZONETABLE_SHIFT] __read_mostly; 74 EXPORT_SYMBOL(zone_table); 75 76 static char *zone_names[MAX_NR_ZONES] = { "DMA", "Normal", "HighMem" }; 77 int min_free_kbytes = 1024; 78 79 unsigned long __initdata nr_kernel_pages; 80 unsigned long __initdata nr_all_pages; 81 82 static int page_outside_zone_boundaries(struct zone *zone, struct page *page) 83 { 84 int ret = 0; 85 unsigned seq; 86 unsigned long pfn = page_to_pfn(page); 87 88 do { 89 seq = zone_span_seqbegin(zone); 90 if (pfn >= zone->zone_start_pfn + zone->spanned_pages) 91 ret = 1; 92 else if (pfn < zone->zone_start_pfn) 93 ret = 1; 94 } while (zone_span_seqretry(zone, seq)); 95 96 return ret; 97 } 98 99 static int page_is_consistent(struct zone *zone, struct page *page) 100 { 101 #ifdef CONFIG_HOLES_IN_ZONE 102 if (!pfn_valid(page_to_pfn(page))) 103 return 0; 104 #endif 105 if (zone != page_zone(page)) 106 return 0; 107 108 return 1; 109 } 110 /* 111 * Temporary debugging check for pages not lying within a given zone. 112 */ 113 static int bad_range(struct zone *zone, struct page *page) 114 { 115 if (page_outside_zone_boundaries(zone, page)) 116 return 1; 117 if (!page_is_consistent(zone, page)) 118 return 1; 119 120 return 0; 121 } 122 123 static void bad_page(const char *function, struct page *page) 124 { 125 printk(KERN_EMERG "Bad page state at %s (in process '%s', page %p)\n", 126 function, current->comm, page); 127 printk(KERN_EMERG "flags:0x%0*lx mapping:%p mapcount:%d count:%d\n", 128 (int)(2*sizeof(page_flags_t)), (unsigned long)page->flags, 129 page->mapping, page_mapcount(page), page_count(page)); 130 printk(KERN_EMERG "Backtrace:\n"); 131 dump_stack(); 132 printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n"); 133 page->flags &= ~(1 << PG_lru | 134 1 << PG_private | 135 1 << PG_locked | 136 1 << PG_active | 137 1 << PG_dirty | 138 1 << PG_reclaim | 139 1 << PG_slab | 140 1 << PG_swapcache | 141 1 << PG_writeback | 142 1 << PG_reserved ); 143 set_page_count(page, 0); 144 reset_page_mapcount(page); 145 page->mapping = NULL; 146 add_taint(TAINT_BAD_PAGE); 147 } 148 149 #ifndef CONFIG_HUGETLB_PAGE 150 #define prep_compound_page(page, order) do { } while (0) 151 #define destroy_compound_page(page, order) do { } while (0) 152 #else 153 /* 154 * Higher-order pages are called "compound pages". They are structured thusly: 155 * 156 * The first PAGE_SIZE page is called the "head page". 157 * 158 * The remaining PAGE_SIZE pages are called "tail pages". 159 * 160 * All pages have PG_compound set. All pages have their ->private pointing at 161 * the head page (even the head page has this). 162 * 163 * The first tail page's ->mapping, if non-zero, holds the address of the 164 * compound page's put_page() function. 165 * 166 * The order of the allocation is stored in the first tail page's ->index 167 * This is only for debug at present. This usage means that zero-order pages 168 * may not be compound. 169 */ 170 static void prep_compound_page(struct page *page, unsigned long order) 171 { 172 int i; 173 int nr_pages = 1 << order; 174 175 page[1].mapping = NULL; 176 page[1].index = order; 177 for (i = 0; i < nr_pages; i++) { 178 struct page *p = page + i; 179 180 SetPageCompound(p); 181 set_page_private(p, (unsigned long)page); 182 } 183 } 184 185 static void destroy_compound_page(struct page *page, unsigned long order) 186 { 187 int i; 188 int nr_pages = 1 << order; 189 190 if (!PageCompound(page)) 191 return; 192 193 if (page[1].index != order) 194 bad_page(__FUNCTION__, page); 195 196 for (i = 0; i < nr_pages; i++) { 197 struct page *p = page + i; 198 199 if (!PageCompound(p)) 200 bad_page(__FUNCTION__, page); 201 if (page_private(p) != (unsigned long)page) 202 bad_page(__FUNCTION__, page); 203 ClearPageCompound(p); 204 } 205 } 206 #endif /* CONFIG_HUGETLB_PAGE */ 207 208 /* 209 * function for dealing with page's order in buddy system. 210 * zone->lock is already acquired when we use these. 211 * So, we don't need atomic page->flags operations here. 212 */ 213 static inline unsigned long page_order(struct page *page) { 214 return page_private(page); 215 } 216 217 static inline void set_page_order(struct page *page, int order) { 218 set_page_private(page, order); 219 __SetPagePrivate(page); 220 } 221 222 static inline void rmv_page_order(struct page *page) 223 { 224 __ClearPagePrivate(page); 225 set_page_private(page, 0); 226 } 227 228 /* 229 * Locate the struct page for both the matching buddy in our 230 * pair (buddy1) and the combined O(n+1) page they form (page). 231 * 232 * 1) Any buddy B1 will have an order O twin B2 which satisfies 233 * the following equation: 234 * B2 = B1 ^ (1 << O) 235 * For example, if the starting buddy (buddy2) is #8 its order 236 * 1 buddy is #10: 237 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 238 * 239 * 2) Any buddy B will have an order O+1 parent P which 240 * satisfies the following equation: 241 * P = B & ~(1 << O) 242 * 243 * Assumption: *_mem_map is contigious at least up to MAX_ORDER 244 */ 245 static inline struct page * 246 __page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order) 247 { 248 unsigned long buddy_idx = page_idx ^ (1 << order); 249 250 return page + (buddy_idx - page_idx); 251 } 252 253 static inline unsigned long 254 __find_combined_index(unsigned long page_idx, unsigned int order) 255 { 256 return (page_idx & ~(1 << order)); 257 } 258 259 /* 260 * This function checks whether a page is free && is the buddy 261 * we can do coalesce a page and its buddy if 262 * (a) the buddy is free && 263 * (b) the buddy is on the buddy system && 264 * (c) a page and its buddy have the same order. 265 * for recording page's order, we use page_private(page) and PG_private. 266 * 267 */ 268 static inline int page_is_buddy(struct page *page, int order) 269 { 270 if (PagePrivate(page) && 271 (page_order(page) == order) && 272 page_count(page) == 0) 273 return 1; 274 return 0; 275 } 276 277 /* 278 * Freeing function for a buddy system allocator. 279 * 280 * The concept of a buddy system is to maintain direct-mapped table 281 * (containing bit values) for memory blocks of various "orders". 282 * The bottom level table contains the map for the smallest allocatable 283 * units of memory (here, pages), and each level above it describes 284 * pairs of units from the levels below, hence, "buddies". 285 * At a high level, all that happens here is marking the table entry 286 * at the bottom level available, and propagating the changes upward 287 * as necessary, plus some accounting needed to play nicely with other 288 * parts of the VM system. 289 * At each level, we keep a list of pages, which are heads of continuous 290 * free pages of length of (1 << order) and marked with PG_Private.Page's 291 * order is recorded in page_private(page) field. 292 * So when we are allocating or freeing one, we can derive the state of the 293 * other. That is, if we allocate a small block, and both were 294 * free, the remainder of the region must be split into blocks. 295 * If a block is freed, and its buddy is also free, then this 296 * triggers coalescing into a block of larger size. 297 * 298 * -- wli 299 */ 300 301 static inline void __free_pages_bulk (struct page *page, 302 struct zone *zone, unsigned int order) 303 { 304 unsigned long page_idx; 305 int order_size = 1 << order; 306 307 if (unlikely(order)) 308 destroy_compound_page(page, order); 309 310 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); 311 312 BUG_ON(page_idx & (order_size - 1)); 313 BUG_ON(bad_range(zone, page)); 314 315 zone->free_pages += order_size; 316 while (order < MAX_ORDER-1) { 317 unsigned long combined_idx; 318 struct free_area *area; 319 struct page *buddy; 320 321 combined_idx = __find_combined_index(page_idx, order); 322 buddy = __page_find_buddy(page, page_idx, order); 323 324 if (bad_range(zone, buddy)) 325 break; 326 if (!page_is_buddy(buddy, order)) 327 break; /* Move the buddy up one level. */ 328 list_del(&buddy->lru); 329 area = zone->free_area + order; 330 area->nr_free--; 331 rmv_page_order(buddy); 332 page = page + (combined_idx - page_idx); 333 page_idx = combined_idx; 334 order++; 335 } 336 set_page_order(page, order); 337 list_add(&page->lru, &zone->free_area[order].free_list); 338 zone->free_area[order].nr_free++; 339 } 340 341 static inline void free_pages_check(const char *function, struct page *page) 342 { 343 if ( page_mapcount(page) || 344 page->mapping != NULL || 345 page_count(page) != 0 || 346 (page->flags & ( 347 1 << PG_lru | 348 1 << PG_private | 349 1 << PG_locked | 350 1 << PG_active | 351 1 << PG_reclaim | 352 1 << PG_slab | 353 1 << PG_swapcache | 354 1 << PG_writeback | 355 1 << PG_reserved ))) 356 bad_page(function, page); 357 if (PageDirty(page)) 358 __ClearPageDirty(page); 359 } 360 361 /* 362 * Frees a list of pages. 363 * Assumes all pages on list are in same zone, and of same order. 364 * count is the number of pages to free. 365 * 366 * If the zone was previously in an "all pages pinned" state then look to 367 * see if this freeing clears that state. 368 * 369 * And clear the zone's pages_scanned counter, to hold off the "all pages are 370 * pinned" detection logic. 371 */ 372 static int 373 free_pages_bulk(struct zone *zone, int count, 374 struct list_head *list, unsigned int order) 375 { 376 unsigned long flags; 377 struct page *page = NULL; 378 int ret = 0; 379 380 spin_lock_irqsave(&zone->lock, flags); 381 zone->all_unreclaimable = 0; 382 zone->pages_scanned = 0; 383 while (!list_empty(list) && count--) { 384 page = list_entry(list->prev, struct page, lru); 385 /* have to delete it as __free_pages_bulk list manipulates */ 386 list_del(&page->lru); 387 __free_pages_bulk(page, zone, order); 388 ret++; 389 } 390 spin_unlock_irqrestore(&zone->lock, flags); 391 return ret; 392 } 393 394 void __free_pages_ok(struct page *page, unsigned int order) 395 { 396 LIST_HEAD(list); 397 int i; 398 399 arch_free_page(page, order); 400 401 mod_page_state(pgfree, 1 << order); 402 403 #ifndef CONFIG_MMU 404 if (order > 0) 405 for (i = 1 ; i < (1 << order) ; ++i) 406 __put_page(page + i); 407 #endif 408 409 for (i = 0 ; i < (1 << order) ; ++i) 410 free_pages_check(__FUNCTION__, page + i); 411 list_add(&page->lru, &list); 412 kernel_map_pages(page, 1<<order, 0); 413 free_pages_bulk(page_zone(page), 1, &list, order); 414 } 415 416 417 /* 418 * The order of subdivision here is critical for the IO subsystem. 419 * Please do not alter this order without good reasons and regression 420 * testing. Specifically, as large blocks of memory are subdivided, 421 * the order in which smaller blocks are delivered depends on the order 422 * they're subdivided in this function. This is the primary factor 423 * influencing the order in which pages are delivered to the IO 424 * subsystem according to empirical testing, and this is also justified 425 * by considering the behavior of a buddy system containing a single 426 * large block of memory acted on by a series of small allocations. 427 * This behavior is a critical factor in sglist merging's success. 428 * 429 * -- wli 430 */ 431 static inline struct page * 432 expand(struct zone *zone, struct page *page, 433 int low, int high, struct free_area *area) 434 { 435 unsigned long size = 1 << high; 436 437 while (high > low) { 438 area--; 439 high--; 440 size >>= 1; 441 BUG_ON(bad_range(zone, &page[size])); 442 list_add(&page[size].lru, &area->free_list); 443 area->nr_free++; 444 set_page_order(&page[size], high); 445 } 446 return page; 447 } 448 449 void set_page_refs(struct page *page, int order) 450 { 451 #ifdef CONFIG_MMU 452 set_page_count(page, 1); 453 #else 454 int i; 455 456 /* 457 * We need to reference all the pages for this order, otherwise if 458 * anyone accesses one of the pages with (get/put) it will be freed. 459 * - eg: access_process_vm() 460 */ 461 for (i = 0; i < (1 << order); i++) 462 set_page_count(page + i, 1); 463 #endif /* CONFIG_MMU */ 464 } 465 466 /* 467 * This page is about to be returned from the page allocator 468 */ 469 static void prep_new_page(struct page *page, int order) 470 { 471 if ( page_mapcount(page) || 472 page->mapping != NULL || 473 page_count(page) != 0 || 474 (page->flags & ( 475 1 << PG_lru | 476 1 << PG_private | 477 1 << PG_locked | 478 1 << PG_active | 479 1 << PG_dirty | 480 1 << PG_reclaim | 481 1 << PG_slab | 482 1 << PG_swapcache | 483 1 << PG_writeback | 484 1 << PG_reserved ))) 485 bad_page(__FUNCTION__, page); 486 487 page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 488 1 << PG_referenced | 1 << PG_arch_1 | 489 1 << PG_checked | 1 << PG_mappedtodisk); 490 set_page_private(page, 0); 491 set_page_refs(page, order); 492 kernel_map_pages(page, 1 << order, 1); 493 } 494 495 /* 496 * Do the hard work of removing an element from the buddy allocator. 497 * Call me with the zone->lock already held. 498 */ 499 static struct page *__rmqueue(struct zone *zone, unsigned int order) 500 { 501 struct free_area * area; 502 unsigned int current_order; 503 struct page *page; 504 505 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 506 area = zone->free_area + current_order; 507 if (list_empty(&area->free_list)) 508 continue; 509 510 page = list_entry(area->free_list.next, struct page, lru); 511 list_del(&page->lru); 512 rmv_page_order(page); 513 area->nr_free--; 514 zone->free_pages -= 1UL << order; 515 return expand(zone, page, order, current_order, area); 516 } 517 518 return NULL; 519 } 520 521 /* 522 * Obtain a specified number of elements from the buddy allocator, all under 523 * a single hold of the lock, for efficiency. Add them to the supplied list. 524 * Returns the number of new pages which were placed at *list. 525 */ 526 static int rmqueue_bulk(struct zone *zone, unsigned int order, 527 unsigned long count, struct list_head *list) 528 { 529 unsigned long flags; 530 int i; 531 int allocated = 0; 532 struct page *page; 533 534 spin_lock_irqsave(&zone->lock, flags); 535 for (i = 0; i < count; ++i) { 536 page = __rmqueue(zone, order); 537 if (page == NULL) 538 break; 539 allocated++; 540 list_add_tail(&page->lru, list); 541 } 542 spin_unlock_irqrestore(&zone->lock, flags); 543 return allocated; 544 } 545 546 #ifdef CONFIG_NUMA 547 /* Called from the slab reaper to drain remote pagesets */ 548 void drain_remote_pages(void) 549 { 550 struct zone *zone; 551 int i; 552 unsigned long flags; 553 554 local_irq_save(flags); 555 for_each_zone(zone) { 556 struct per_cpu_pageset *pset; 557 558 /* Do not drain local pagesets */ 559 if (zone->zone_pgdat->node_id == numa_node_id()) 560 continue; 561 562 pset = zone->pageset[smp_processor_id()]; 563 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) { 564 struct per_cpu_pages *pcp; 565 566 pcp = &pset->pcp[i]; 567 if (pcp->count) 568 pcp->count -= free_pages_bulk(zone, pcp->count, 569 &pcp->list, 0); 570 } 571 } 572 local_irq_restore(flags); 573 } 574 #endif 575 576 #if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU) 577 static void __drain_pages(unsigned int cpu) 578 { 579 struct zone *zone; 580 int i; 581 582 for_each_zone(zone) { 583 struct per_cpu_pageset *pset; 584 585 pset = zone_pcp(zone, cpu); 586 for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) { 587 struct per_cpu_pages *pcp; 588 589 pcp = &pset->pcp[i]; 590 pcp->count -= free_pages_bulk(zone, pcp->count, 591 &pcp->list, 0); 592 } 593 } 594 } 595 #endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */ 596 597 #ifdef CONFIG_PM 598 599 void mark_free_pages(struct zone *zone) 600 { 601 unsigned long zone_pfn, flags; 602 int order; 603 struct list_head *curr; 604 605 if (!zone->spanned_pages) 606 return; 607 608 spin_lock_irqsave(&zone->lock, flags); 609 for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn) 610 ClearPageNosaveFree(pfn_to_page(zone_pfn + zone->zone_start_pfn)); 611 612 for (order = MAX_ORDER - 1; order >= 0; --order) 613 list_for_each(curr, &zone->free_area[order].free_list) { 614 unsigned long start_pfn, i; 615 616 start_pfn = page_to_pfn(list_entry(curr, struct page, lru)); 617 618 for (i=0; i < (1<<order); i++) 619 SetPageNosaveFree(pfn_to_page(start_pfn+i)); 620 } 621 spin_unlock_irqrestore(&zone->lock, flags); 622 } 623 624 /* 625 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 626 */ 627 void drain_local_pages(void) 628 { 629 unsigned long flags; 630 631 local_irq_save(flags); 632 __drain_pages(smp_processor_id()); 633 local_irq_restore(flags); 634 } 635 #endif /* CONFIG_PM */ 636 637 static void zone_statistics(struct zonelist *zonelist, struct zone *z) 638 { 639 #ifdef CONFIG_NUMA 640 unsigned long flags; 641 int cpu; 642 pg_data_t *pg = z->zone_pgdat; 643 pg_data_t *orig = zonelist->zones[0]->zone_pgdat; 644 struct per_cpu_pageset *p; 645 646 local_irq_save(flags); 647 cpu = smp_processor_id(); 648 p = zone_pcp(z,cpu); 649 if (pg == orig) { 650 p->numa_hit++; 651 } else { 652 p->numa_miss++; 653 zone_pcp(zonelist->zones[0], cpu)->numa_foreign++; 654 } 655 if (pg == NODE_DATA(numa_node_id())) 656 p->local_node++; 657 else 658 p->other_node++; 659 local_irq_restore(flags); 660 #endif 661 } 662 663 /* 664 * Free a 0-order page 665 */ 666 static void FASTCALL(free_hot_cold_page(struct page *page, int cold)); 667 static void fastcall free_hot_cold_page(struct page *page, int cold) 668 { 669 struct zone *zone = page_zone(page); 670 struct per_cpu_pages *pcp; 671 unsigned long flags; 672 673 arch_free_page(page, 0); 674 675 kernel_map_pages(page, 1, 0); 676 inc_page_state(pgfree); 677 if (PageAnon(page)) 678 page->mapping = NULL; 679 free_pages_check(__FUNCTION__, page); 680 pcp = &zone_pcp(zone, get_cpu())->pcp[cold]; 681 local_irq_save(flags); 682 list_add(&page->lru, &pcp->list); 683 pcp->count++; 684 if (pcp->count >= pcp->high) 685 pcp->count -= free_pages_bulk(zone, pcp->batch, &pcp->list, 0); 686 local_irq_restore(flags); 687 put_cpu(); 688 } 689 690 void fastcall free_hot_page(struct page *page) 691 { 692 free_hot_cold_page(page, 0); 693 } 694 695 void fastcall free_cold_page(struct page *page) 696 { 697 free_hot_cold_page(page, 1); 698 } 699 700 static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) 701 { 702 int i; 703 704 BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM); 705 for(i = 0; i < (1 << order); i++) 706 clear_highpage(page + i); 707 } 708 709 /* 710 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 711 * we cheat by calling it from here, in the order > 0 path. Saves a branch 712 * or two. 713 */ 714 static struct page * 715 buffered_rmqueue(struct zone *zone, int order, gfp_t gfp_flags) 716 { 717 unsigned long flags; 718 struct page *page = NULL; 719 int cold = !!(gfp_flags & __GFP_COLD); 720 721 if (order == 0) { 722 struct per_cpu_pages *pcp; 723 724 pcp = &zone_pcp(zone, get_cpu())->pcp[cold]; 725 local_irq_save(flags); 726 if (pcp->count <= pcp->low) 727 pcp->count += rmqueue_bulk(zone, 0, 728 pcp->batch, &pcp->list); 729 if (pcp->count) { 730 page = list_entry(pcp->list.next, struct page, lru); 731 list_del(&page->lru); 732 pcp->count--; 733 } 734 local_irq_restore(flags); 735 put_cpu(); 736 } 737 738 if (page == NULL) { 739 spin_lock_irqsave(&zone->lock, flags); 740 page = __rmqueue(zone, order); 741 spin_unlock_irqrestore(&zone->lock, flags); 742 } 743 744 if (page != NULL) { 745 BUG_ON(bad_range(zone, page)); 746 mod_page_state_zone(zone, pgalloc, 1 << order); 747 prep_new_page(page, order); 748 749 if (gfp_flags & __GFP_ZERO) 750 prep_zero_page(page, order, gfp_flags); 751 752 if (order && (gfp_flags & __GFP_COMP)) 753 prep_compound_page(page, order); 754 } 755 return page; 756 } 757 758 /* 759 * Return 1 if free pages are above 'mark'. This takes into account the order 760 * of the allocation. 761 */ 762 int zone_watermark_ok(struct zone *z, int order, unsigned long mark, 763 int classzone_idx, int can_try_harder, gfp_t gfp_high) 764 { 765 /* free_pages my go negative - that's OK */ 766 long min = mark, free_pages = z->free_pages - (1 << order) + 1; 767 int o; 768 769 if (gfp_high) 770 min -= min / 2; 771 if (can_try_harder) 772 min -= min / 4; 773 774 if (free_pages <= min + z->lowmem_reserve[classzone_idx]) 775 return 0; 776 for (o = 0; o < order; o++) { 777 /* At the next order, this order's pages become unavailable */ 778 free_pages -= z->free_area[o].nr_free << o; 779 780 /* Require fewer higher order pages to be free */ 781 min >>= 1; 782 783 if (free_pages <= min) 784 return 0; 785 } 786 return 1; 787 } 788 789 static inline int 790 should_reclaim_zone(struct zone *z, gfp_t gfp_mask) 791 { 792 if (!z->reclaim_pages) 793 return 0; 794 if (gfp_mask & __GFP_NORECLAIM) 795 return 0; 796 return 1; 797 } 798 799 /* 800 * This is the 'heart' of the zoned buddy allocator. 801 */ 802 struct page * fastcall 803 __alloc_pages(gfp_t gfp_mask, unsigned int order, 804 struct zonelist *zonelist) 805 { 806 const gfp_t wait = gfp_mask & __GFP_WAIT; 807 struct zone **zones, *z; 808 struct page *page; 809 struct reclaim_state reclaim_state; 810 struct task_struct *p = current; 811 int i; 812 int classzone_idx; 813 int do_retry; 814 int can_try_harder; 815 int did_some_progress; 816 817 might_sleep_if(wait); 818 819 /* 820 * The caller may dip into page reserves a bit more if the caller 821 * cannot run direct reclaim, or is the caller has realtime scheduling 822 * policy 823 */ 824 can_try_harder = (unlikely(rt_task(p)) && !in_interrupt()) || !wait; 825 826 zones = zonelist->zones; /* the list of zones suitable for gfp_mask */ 827 828 if (unlikely(zones[0] == NULL)) { 829 /* Should this ever happen?? */ 830 return NULL; 831 } 832 833 classzone_idx = zone_idx(zones[0]); 834 835 restart: 836 /* 837 * Go through the zonelist once, looking for a zone with enough free. 838 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 839 */ 840 for (i = 0; (z = zones[i]) != NULL; i++) { 841 int do_reclaim = should_reclaim_zone(z, gfp_mask); 842 843 if (!cpuset_zone_allowed(z, __GFP_HARDWALL)) 844 continue; 845 846 /* 847 * If the zone is to attempt early page reclaim then this loop 848 * will try to reclaim pages and check the watermark a second 849 * time before giving up and falling back to the next zone. 850 */ 851 zone_reclaim_retry: 852 if (!zone_watermark_ok(z, order, z->pages_low, 853 classzone_idx, 0, 0)) { 854 if (!do_reclaim) 855 continue; 856 else { 857 zone_reclaim(z, gfp_mask, order); 858 /* Only try reclaim once */ 859 do_reclaim = 0; 860 goto zone_reclaim_retry; 861 } 862 } 863 864 page = buffered_rmqueue(z, order, gfp_mask); 865 if (page) 866 goto got_pg; 867 } 868 869 for (i = 0; (z = zones[i]) != NULL; i++) 870 wakeup_kswapd(z, order); 871 872 /* 873 * Go through the zonelist again. Let __GFP_HIGH and allocations 874 * coming from realtime tasks to go deeper into reserves 875 * 876 * This is the last chance, in general, before the goto nopage. 877 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. 878 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 879 */ 880 for (i = 0; (z = zones[i]) != NULL; i++) { 881 if (!zone_watermark_ok(z, order, z->pages_min, 882 classzone_idx, can_try_harder, 883 gfp_mask & __GFP_HIGH)) 884 continue; 885 886 if (wait && !cpuset_zone_allowed(z, gfp_mask)) 887 continue; 888 889 page = buffered_rmqueue(z, order, gfp_mask); 890 if (page) 891 goto got_pg; 892 } 893 894 /* This allocation should allow future memory freeing. */ 895 896 if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) 897 && !in_interrupt()) { 898 if (!(gfp_mask & __GFP_NOMEMALLOC)) { 899 /* go through the zonelist yet again, ignoring mins */ 900 for (i = 0; (z = zones[i]) != NULL; i++) { 901 if (!cpuset_zone_allowed(z, gfp_mask)) 902 continue; 903 page = buffered_rmqueue(z, order, gfp_mask); 904 if (page) 905 goto got_pg; 906 } 907 } 908 goto nopage; 909 } 910 911 /* Atomic allocations - we can't balance anything */ 912 if (!wait) 913 goto nopage; 914 915 rebalance: 916 cond_resched(); 917 918 /* We now go into synchronous reclaim */ 919 p->flags |= PF_MEMALLOC; 920 reclaim_state.reclaimed_slab = 0; 921 p->reclaim_state = &reclaim_state; 922 923 did_some_progress = try_to_free_pages(zones, gfp_mask); 924 925 p->reclaim_state = NULL; 926 p->flags &= ~PF_MEMALLOC; 927 928 cond_resched(); 929 930 if (likely(did_some_progress)) { 931 for (i = 0; (z = zones[i]) != NULL; i++) { 932 if (!zone_watermark_ok(z, order, z->pages_min, 933 classzone_idx, can_try_harder, 934 gfp_mask & __GFP_HIGH)) 935 continue; 936 937 if (!cpuset_zone_allowed(z, gfp_mask)) 938 continue; 939 940 page = buffered_rmqueue(z, order, gfp_mask); 941 if (page) 942 goto got_pg; 943 } 944 } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { 945 /* 946 * Go through the zonelist yet one more time, keep 947 * very high watermark here, this is only to catch 948 * a parallel oom killing, we must fail if we're still 949 * under heavy pressure. 950 */ 951 for (i = 0; (z = zones[i]) != NULL; i++) { 952 if (!zone_watermark_ok(z, order, z->pages_high, 953 classzone_idx, 0, 0)) 954 continue; 955 956 if (!cpuset_zone_allowed(z, __GFP_HARDWALL)) 957 continue; 958 959 page = buffered_rmqueue(z, order, gfp_mask); 960 if (page) 961 goto got_pg; 962 } 963 964 out_of_memory(gfp_mask, order); 965 goto restart; 966 } 967 968 /* 969 * Don't let big-order allocations loop unless the caller explicitly 970 * requests that. Wait for some write requests to complete then retry. 971 * 972 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order 973 * <= 3, but that may not be true in other implementations. 974 */ 975 do_retry = 0; 976 if (!(gfp_mask & __GFP_NORETRY)) { 977 if ((order <= 3) || (gfp_mask & __GFP_REPEAT)) 978 do_retry = 1; 979 if (gfp_mask & __GFP_NOFAIL) 980 do_retry = 1; 981 } 982 if (do_retry) { 983 blk_congestion_wait(WRITE, HZ/50); 984 goto rebalance; 985 } 986 987 nopage: 988 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) { 989 printk(KERN_WARNING "%s: page allocation failure." 990 " order:%d, mode:0x%x\n", 991 p->comm, order, gfp_mask); 992 dump_stack(); 993 show_mem(); 994 } 995 return NULL; 996 got_pg: 997 zone_statistics(zonelist, z); 998 return page; 999 } 1000 1001 EXPORT_SYMBOL(__alloc_pages); 1002 1003 /* 1004 * Common helper functions. 1005 */ 1006 fastcall unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 1007 { 1008 struct page * page; 1009 page = alloc_pages(gfp_mask, order); 1010 if (!page) 1011 return 0; 1012 return (unsigned long) page_address(page); 1013 } 1014 1015 EXPORT_SYMBOL(__get_free_pages); 1016 1017 fastcall unsigned long get_zeroed_page(gfp_t gfp_mask) 1018 { 1019 struct page * page; 1020 1021 /* 1022 * get_zeroed_page() returns a 32-bit address, which cannot represent 1023 * a highmem page 1024 */ 1025 BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 1026 1027 page = alloc_pages(gfp_mask | __GFP_ZERO, 0); 1028 if (page) 1029 return (unsigned long) page_address(page); 1030 return 0; 1031 } 1032 1033 EXPORT_SYMBOL(get_zeroed_page); 1034 1035 void __pagevec_free(struct pagevec *pvec) 1036 { 1037 int i = pagevec_count(pvec); 1038 1039 while (--i >= 0) 1040 free_hot_cold_page(pvec->pages[i], pvec->cold); 1041 } 1042 1043 fastcall void __free_pages(struct page *page, unsigned int order) 1044 { 1045 if (put_page_testzero(page)) { 1046 if (order == 0) 1047 free_hot_page(page); 1048 else 1049 __free_pages_ok(page, order); 1050 } 1051 } 1052 1053 EXPORT_SYMBOL(__free_pages); 1054 1055 fastcall void free_pages(unsigned long addr, unsigned int order) 1056 { 1057 if (addr != 0) { 1058 BUG_ON(!virt_addr_valid((void *)addr)); 1059 __free_pages(virt_to_page((void *)addr), order); 1060 } 1061 } 1062 1063 EXPORT_SYMBOL(free_pages); 1064 1065 /* 1066 * Total amount of free (allocatable) RAM: 1067 */ 1068 unsigned int nr_free_pages(void) 1069 { 1070 unsigned int sum = 0; 1071 struct zone *zone; 1072 1073 for_each_zone(zone) 1074 sum += zone->free_pages; 1075 1076 return sum; 1077 } 1078 1079 EXPORT_SYMBOL(nr_free_pages); 1080 1081 #ifdef CONFIG_NUMA 1082 unsigned int nr_free_pages_pgdat(pg_data_t *pgdat) 1083 { 1084 unsigned int i, sum = 0; 1085 1086 for (i = 0; i < MAX_NR_ZONES; i++) 1087 sum += pgdat->node_zones[i].free_pages; 1088 1089 return sum; 1090 } 1091 #endif 1092 1093 static unsigned int nr_free_zone_pages(int offset) 1094 { 1095 /* Just pick one node, since fallback list is circular */ 1096 pg_data_t *pgdat = NODE_DATA(numa_node_id()); 1097 unsigned int sum = 0; 1098 1099 struct zonelist *zonelist = pgdat->node_zonelists + offset; 1100 struct zone **zonep = zonelist->zones; 1101 struct zone *zone; 1102 1103 for (zone = *zonep++; zone; zone = *zonep++) { 1104 unsigned long size = zone->present_pages; 1105 unsigned long high = zone->pages_high; 1106 if (size > high) 1107 sum += size - high; 1108 } 1109 1110 return sum; 1111 } 1112 1113 /* 1114 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL 1115 */ 1116 unsigned int nr_free_buffer_pages(void) 1117 { 1118 return nr_free_zone_pages(gfp_zone(GFP_USER)); 1119 } 1120 1121 /* 1122 * Amount of free RAM allocatable within all zones 1123 */ 1124 unsigned int nr_free_pagecache_pages(void) 1125 { 1126 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER)); 1127 } 1128 1129 #ifdef CONFIG_HIGHMEM 1130 unsigned int nr_free_highpages (void) 1131 { 1132 pg_data_t *pgdat; 1133 unsigned int pages = 0; 1134 1135 for_each_pgdat(pgdat) 1136 pages += pgdat->node_zones[ZONE_HIGHMEM].free_pages; 1137 1138 return pages; 1139 } 1140 #endif 1141 1142 #ifdef CONFIG_NUMA 1143 static void show_node(struct zone *zone) 1144 { 1145 printk("Node %d ", zone->zone_pgdat->node_id); 1146 } 1147 #else 1148 #define show_node(zone) do { } while (0) 1149 #endif 1150 1151 /* 1152 * Accumulate the page_state information across all CPUs. 1153 * The result is unavoidably approximate - it can change 1154 * during and after execution of this function. 1155 */ 1156 static DEFINE_PER_CPU(struct page_state, page_states) = {0}; 1157 1158 atomic_t nr_pagecache = ATOMIC_INIT(0); 1159 EXPORT_SYMBOL(nr_pagecache); 1160 #ifdef CONFIG_SMP 1161 DEFINE_PER_CPU(long, nr_pagecache_local) = 0; 1162 #endif 1163 1164 void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask) 1165 { 1166 int cpu = 0; 1167 1168 memset(ret, 0, sizeof(*ret)); 1169 cpus_and(*cpumask, *cpumask, cpu_online_map); 1170 1171 cpu = first_cpu(*cpumask); 1172 while (cpu < NR_CPUS) { 1173 unsigned long *in, *out, off; 1174 1175 in = (unsigned long *)&per_cpu(page_states, cpu); 1176 1177 cpu = next_cpu(cpu, *cpumask); 1178 1179 if (cpu < NR_CPUS) 1180 prefetch(&per_cpu(page_states, cpu)); 1181 1182 out = (unsigned long *)ret; 1183 for (off = 0; off < nr; off++) 1184 *out++ += *in++; 1185 } 1186 } 1187 1188 void get_page_state_node(struct page_state *ret, int node) 1189 { 1190 int nr; 1191 cpumask_t mask = node_to_cpumask(node); 1192 1193 nr = offsetof(struct page_state, GET_PAGE_STATE_LAST); 1194 nr /= sizeof(unsigned long); 1195 1196 __get_page_state(ret, nr+1, &mask); 1197 } 1198 1199 void get_page_state(struct page_state *ret) 1200 { 1201 int nr; 1202 cpumask_t mask = CPU_MASK_ALL; 1203 1204 nr = offsetof(struct page_state, GET_PAGE_STATE_LAST); 1205 nr /= sizeof(unsigned long); 1206 1207 __get_page_state(ret, nr + 1, &mask); 1208 } 1209 1210 void get_full_page_state(struct page_state *ret) 1211 { 1212 cpumask_t mask = CPU_MASK_ALL; 1213 1214 __get_page_state(ret, sizeof(*ret) / sizeof(unsigned long), &mask); 1215 } 1216 1217 unsigned long __read_page_state(unsigned long offset) 1218 { 1219 unsigned long ret = 0; 1220 int cpu; 1221 1222 for_each_online_cpu(cpu) { 1223 unsigned long in; 1224 1225 in = (unsigned long)&per_cpu(page_states, cpu) + offset; 1226 ret += *((unsigned long *)in); 1227 } 1228 return ret; 1229 } 1230 1231 void __mod_page_state(unsigned long offset, unsigned long delta) 1232 { 1233 unsigned long flags; 1234 void* ptr; 1235 1236 local_irq_save(flags); 1237 ptr = &__get_cpu_var(page_states); 1238 *(unsigned long*)(ptr + offset) += delta; 1239 local_irq_restore(flags); 1240 } 1241 1242 EXPORT_SYMBOL(__mod_page_state); 1243 1244 void __get_zone_counts(unsigned long *active, unsigned long *inactive, 1245 unsigned long *free, struct pglist_data *pgdat) 1246 { 1247 struct zone *zones = pgdat->node_zones; 1248 int i; 1249 1250 *active = 0; 1251 *inactive = 0; 1252 *free = 0; 1253 for (i = 0; i < MAX_NR_ZONES; i++) { 1254 *active += zones[i].nr_active; 1255 *inactive += zones[i].nr_inactive; 1256 *free += zones[i].free_pages; 1257 } 1258 } 1259 1260 void get_zone_counts(unsigned long *active, 1261 unsigned long *inactive, unsigned long *free) 1262 { 1263 struct pglist_data *pgdat; 1264 1265 *active = 0; 1266 *inactive = 0; 1267 *free = 0; 1268 for_each_pgdat(pgdat) { 1269 unsigned long l, m, n; 1270 __get_zone_counts(&l, &m, &n, pgdat); 1271 *active += l; 1272 *inactive += m; 1273 *free += n; 1274 } 1275 } 1276 1277 void si_meminfo(struct sysinfo *val) 1278 { 1279 val->totalram = totalram_pages; 1280 val->sharedram = 0; 1281 val->freeram = nr_free_pages(); 1282 val->bufferram = nr_blockdev_pages(); 1283 #ifdef CONFIG_HIGHMEM 1284 val->totalhigh = totalhigh_pages; 1285 val->freehigh = nr_free_highpages(); 1286 #else 1287 val->totalhigh = 0; 1288 val->freehigh = 0; 1289 #endif 1290 val->mem_unit = PAGE_SIZE; 1291 } 1292 1293 EXPORT_SYMBOL(si_meminfo); 1294 1295 #ifdef CONFIG_NUMA 1296 void si_meminfo_node(struct sysinfo *val, int nid) 1297 { 1298 pg_data_t *pgdat = NODE_DATA(nid); 1299 1300 val->totalram = pgdat->node_present_pages; 1301 val->freeram = nr_free_pages_pgdat(pgdat); 1302 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; 1303 val->freehigh = pgdat->node_zones[ZONE_HIGHMEM].free_pages; 1304 val->mem_unit = PAGE_SIZE; 1305 } 1306 #endif 1307 1308 #define K(x) ((x) << (PAGE_SHIFT-10)) 1309 1310 /* 1311 * Show free area list (used inside shift_scroll-lock stuff) 1312 * We also calculate the percentage fragmentation. We do this by counting the 1313 * memory on each free list with the exception of the first item on the list. 1314 */ 1315 void show_free_areas(void) 1316 { 1317 struct page_state ps; 1318 int cpu, temperature; 1319 unsigned long active; 1320 unsigned long inactive; 1321 unsigned long free; 1322 struct zone *zone; 1323 1324 for_each_zone(zone) { 1325 show_node(zone); 1326 printk("%s per-cpu:", zone->name); 1327 1328 if (!zone->present_pages) { 1329 printk(" empty\n"); 1330 continue; 1331 } else 1332 printk("\n"); 1333 1334 for_each_cpu(cpu) { 1335 struct per_cpu_pageset *pageset; 1336 1337 pageset = zone_pcp(zone, cpu); 1338 1339 for (temperature = 0; temperature < 2; temperature++) 1340 printk("cpu %d %s: low %d, high %d, batch %d used:%d\n", 1341 cpu, 1342 temperature ? "cold" : "hot", 1343 pageset->pcp[temperature].low, 1344 pageset->pcp[temperature].high, 1345 pageset->pcp[temperature].batch, 1346 pageset->pcp[temperature].count); 1347 } 1348 } 1349 1350 get_page_state(&ps); 1351 get_zone_counts(&active, &inactive, &free); 1352 1353 printk("Free pages: %11ukB (%ukB HighMem)\n", 1354 K(nr_free_pages()), 1355 K(nr_free_highpages())); 1356 1357 printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu " 1358 "unstable:%lu free:%u slab:%lu mapped:%lu pagetables:%lu\n", 1359 active, 1360 inactive, 1361 ps.nr_dirty, 1362 ps.nr_writeback, 1363 ps.nr_unstable, 1364 nr_free_pages(), 1365 ps.nr_slab, 1366 ps.nr_mapped, 1367 ps.nr_page_table_pages); 1368 1369 for_each_zone(zone) { 1370 int i; 1371 1372 show_node(zone); 1373 printk("%s" 1374 " free:%lukB" 1375 " min:%lukB" 1376 " low:%lukB" 1377 " high:%lukB" 1378 " active:%lukB" 1379 " inactive:%lukB" 1380 " present:%lukB" 1381 " pages_scanned:%lu" 1382 " all_unreclaimable? %s" 1383 "\n", 1384 zone->name, 1385 K(zone->free_pages), 1386 K(zone->pages_min), 1387 K(zone->pages_low), 1388 K(zone->pages_high), 1389 K(zone->nr_active), 1390 K(zone->nr_inactive), 1391 K(zone->present_pages), 1392 zone->pages_scanned, 1393 (zone->all_unreclaimable ? "yes" : "no") 1394 ); 1395 printk("lowmem_reserve[]:"); 1396 for (i = 0; i < MAX_NR_ZONES; i++) 1397 printk(" %lu", zone->lowmem_reserve[i]); 1398 printk("\n"); 1399 } 1400 1401 for_each_zone(zone) { 1402 unsigned long nr, flags, order, total = 0; 1403 1404 show_node(zone); 1405 printk("%s: ", zone->name); 1406 if (!zone->present_pages) { 1407 printk("empty\n"); 1408 continue; 1409 } 1410 1411 spin_lock_irqsave(&zone->lock, flags); 1412 for (order = 0; order < MAX_ORDER; order++) { 1413 nr = zone->free_area[order].nr_free; 1414 total += nr << order; 1415 printk("%lu*%lukB ", nr, K(1UL) << order); 1416 } 1417 spin_unlock_irqrestore(&zone->lock, flags); 1418 printk("= %lukB\n", K(total)); 1419 } 1420 1421 show_swap_cache_info(); 1422 } 1423 1424 /* 1425 * Builds allocation fallback zone lists. 1426 */ 1427 static int __init build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, int j, int k) 1428 { 1429 switch (k) { 1430 struct zone *zone; 1431 default: 1432 BUG(); 1433 case ZONE_HIGHMEM: 1434 zone = pgdat->node_zones + ZONE_HIGHMEM; 1435 if (zone->present_pages) { 1436 #ifndef CONFIG_HIGHMEM 1437 BUG(); 1438 #endif 1439 zonelist->zones[j++] = zone; 1440 } 1441 case ZONE_NORMAL: 1442 zone = pgdat->node_zones + ZONE_NORMAL; 1443 if (zone->present_pages) 1444 zonelist->zones[j++] = zone; 1445 case ZONE_DMA: 1446 zone = pgdat->node_zones + ZONE_DMA; 1447 if (zone->present_pages) 1448 zonelist->zones[j++] = zone; 1449 } 1450 1451 return j; 1452 } 1453 1454 static inline int highest_zone(int zone_bits) 1455 { 1456 int res = ZONE_NORMAL; 1457 if (zone_bits & (__force int)__GFP_HIGHMEM) 1458 res = ZONE_HIGHMEM; 1459 if (zone_bits & (__force int)__GFP_DMA) 1460 res = ZONE_DMA; 1461 return res; 1462 } 1463 1464 #ifdef CONFIG_NUMA 1465 #define MAX_NODE_LOAD (num_online_nodes()) 1466 static int __initdata node_load[MAX_NUMNODES]; 1467 /** 1468 * find_next_best_node - find the next node that should appear in a given node's fallback list 1469 * @node: node whose fallback list we're appending 1470 * @used_node_mask: nodemask_t of already used nodes 1471 * 1472 * We use a number of factors to determine which is the next node that should 1473 * appear on a given node's fallback list. The node should not have appeared 1474 * already in @node's fallback list, and it should be the next closest node 1475 * according to the distance array (which contains arbitrary distance values 1476 * from each node to each node in the system), and should also prefer nodes 1477 * with no CPUs, since presumably they'll have very little allocation pressure 1478 * on them otherwise. 1479 * It returns -1 if no node is found. 1480 */ 1481 static int __init find_next_best_node(int node, nodemask_t *used_node_mask) 1482 { 1483 int i, n, val; 1484 int min_val = INT_MAX; 1485 int best_node = -1; 1486 1487 for_each_online_node(i) { 1488 cpumask_t tmp; 1489 1490 /* Start from local node */ 1491 n = (node+i) % num_online_nodes(); 1492 1493 /* Don't want a node to appear more than once */ 1494 if (node_isset(n, *used_node_mask)) 1495 continue; 1496 1497 /* Use the local node if we haven't already */ 1498 if (!node_isset(node, *used_node_mask)) { 1499 best_node = node; 1500 break; 1501 } 1502 1503 /* Use the distance array to find the distance */ 1504 val = node_distance(node, n); 1505 1506 /* Give preference to headless and unused nodes */ 1507 tmp = node_to_cpumask(n); 1508 if (!cpus_empty(tmp)) 1509 val += PENALTY_FOR_NODE_WITH_CPUS; 1510 1511 /* Slight preference for less loaded node */ 1512 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 1513 val += node_load[n]; 1514 1515 if (val < min_val) { 1516 min_val = val; 1517 best_node = n; 1518 } 1519 } 1520 1521 if (best_node >= 0) 1522 node_set(best_node, *used_node_mask); 1523 1524 return best_node; 1525 } 1526 1527 static void __init build_zonelists(pg_data_t *pgdat) 1528 { 1529 int i, j, k, node, local_node; 1530 int prev_node, load; 1531 struct zonelist *zonelist; 1532 nodemask_t used_mask; 1533 1534 /* initialize zonelists */ 1535 for (i = 0; i < GFP_ZONETYPES; i++) { 1536 zonelist = pgdat->node_zonelists + i; 1537 zonelist->zones[0] = NULL; 1538 } 1539 1540 /* NUMA-aware ordering of nodes */ 1541 local_node = pgdat->node_id; 1542 load = num_online_nodes(); 1543 prev_node = local_node; 1544 nodes_clear(used_mask); 1545 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 1546 /* 1547 * We don't want to pressure a particular node. 1548 * So adding penalty to the first node in same 1549 * distance group to make it round-robin. 1550 */ 1551 if (node_distance(local_node, node) != 1552 node_distance(local_node, prev_node)) 1553 node_load[node] += load; 1554 prev_node = node; 1555 load--; 1556 for (i = 0; i < GFP_ZONETYPES; i++) { 1557 zonelist = pgdat->node_zonelists + i; 1558 for (j = 0; zonelist->zones[j] != NULL; j++); 1559 1560 k = highest_zone(i); 1561 1562 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k); 1563 zonelist->zones[j] = NULL; 1564 } 1565 } 1566 } 1567 1568 #else /* CONFIG_NUMA */ 1569 1570 static void __init build_zonelists(pg_data_t *pgdat) 1571 { 1572 int i, j, k, node, local_node; 1573 1574 local_node = pgdat->node_id; 1575 for (i = 0; i < GFP_ZONETYPES; i++) { 1576 struct zonelist *zonelist; 1577 1578 zonelist = pgdat->node_zonelists + i; 1579 1580 j = 0; 1581 k = highest_zone(i); 1582 j = build_zonelists_node(pgdat, zonelist, j, k); 1583 /* 1584 * Now we build the zonelist so that it contains the zones 1585 * of all the other nodes. 1586 * We don't want to pressure a particular node, so when 1587 * building the zones for node N, we make sure that the 1588 * zones coming right after the local ones are those from 1589 * node N+1 (modulo N) 1590 */ 1591 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 1592 if (!node_online(node)) 1593 continue; 1594 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k); 1595 } 1596 for (node = 0; node < local_node; node++) { 1597 if (!node_online(node)) 1598 continue; 1599 j = build_zonelists_node(NODE_DATA(node), zonelist, j, k); 1600 } 1601 1602 zonelist->zones[j] = NULL; 1603 } 1604 } 1605 1606 #endif /* CONFIG_NUMA */ 1607 1608 void __init build_all_zonelists(void) 1609 { 1610 int i; 1611 1612 for_each_online_node(i) 1613 build_zonelists(NODE_DATA(i)); 1614 printk("Built %i zonelists\n", num_online_nodes()); 1615 cpuset_init_current_mems_allowed(); 1616 } 1617 1618 /* 1619 * Helper functions to size the waitqueue hash table. 1620 * Essentially these want to choose hash table sizes sufficiently 1621 * large so that collisions trying to wait on pages are rare. 1622 * But in fact, the number of active page waitqueues on typical 1623 * systems is ridiculously low, less than 200. So this is even 1624 * conservative, even though it seems large. 1625 * 1626 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 1627 * waitqueues, i.e. the size of the waitq table given the number of pages. 1628 */ 1629 #define PAGES_PER_WAITQUEUE 256 1630 1631 static inline unsigned long wait_table_size(unsigned long pages) 1632 { 1633 unsigned long size = 1; 1634 1635 pages /= PAGES_PER_WAITQUEUE; 1636 1637 while (size < pages) 1638 size <<= 1; 1639 1640 /* 1641 * Once we have dozens or even hundreds of threads sleeping 1642 * on IO we've got bigger problems than wait queue collision. 1643 * Limit the size of the wait table to a reasonable size. 1644 */ 1645 size = min(size, 4096UL); 1646 1647 return max(size, 4UL); 1648 } 1649 1650 /* 1651 * This is an integer logarithm so that shifts can be used later 1652 * to extract the more random high bits from the multiplicative 1653 * hash function before the remainder is taken. 1654 */ 1655 static inline unsigned long wait_table_bits(unsigned long size) 1656 { 1657 return ffz(~size); 1658 } 1659 1660 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) 1661 1662 static void __init calculate_zone_totalpages(struct pglist_data *pgdat, 1663 unsigned long *zones_size, unsigned long *zholes_size) 1664 { 1665 unsigned long realtotalpages, totalpages = 0; 1666 int i; 1667 1668 for (i = 0; i < MAX_NR_ZONES; i++) 1669 totalpages += zones_size[i]; 1670 pgdat->node_spanned_pages = totalpages; 1671 1672 realtotalpages = totalpages; 1673 if (zholes_size) 1674 for (i = 0; i < MAX_NR_ZONES; i++) 1675 realtotalpages -= zholes_size[i]; 1676 pgdat->node_present_pages = realtotalpages; 1677 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages); 1678 } 1679 1680 1681 /* 1682 * Initially all pages are reserved - free ones are freed 1683 * up by free_all_bootmem() once the early boot process is 1684 * done. Non-atomic initialization, single-pass. 1685 */ 1686 void __devinit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 1687 unsigned long start_pfn) 1688 { 1689 struct page *page; 1690 unsigned long end_pfn = start_pfn + size; 1691 unsigned long pfn; 1692 1693 for (pfn = start_pfn; pfn < end_pfn; pfn++, page++) { 1694 if (!early_pfn_valid(pfn)) 1695 continue; 1696 if (!early_pfn_in_nid(pfn, nid)) 1697 continue; 1698 page = pfn_to_page(pfn); 1699 set_page_links(page, zone, nid, pfn); 1700 set_page_count(page, 1); 1701 reset_page_mapcount(page); 1702 SetPageReserved(page); 1703 INIT_LIST_HEAD(&page->lru); 1704 #ifdef WANT_PAGE_VIRTUAL 1705 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 1706 if (!is_highmem_idx(zone)) 1707 set_page_address(page, __va(pfn << PAGE_SHIFT)); 1708 #endif 1709 } 1710 } 1711 1712 void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone, 1713 unsigned long size) 1714 { 1715 int order; 1716 for (order = 0; order < MAX_ORDER ; order++) { 1717 INIT_LIST_HEAD(&zone->free_area[order].free_list); 1718 zone->free_area[order].nr_free = 0; 1719 } 1720 } 1721 1722 #define ZONETABLE_INDEX(x, zone_nr) ((x << ZONES_SHIFT) | zone_nr) 1723 void zonetable_add(struct zone *zone, int nid, int zid, unsigned long pfn, 1724 unsigned long size) 1725 { 1726 unsigned long snum = pfn_to_section_nr(pfn); 1727 unsigned long end = pfn_to_section_nr(pfn + size); 1728 1729 if (FLAGS_HAS_NODE) 1730 zone_table[ZONETABLE_INDEX(nid, zid)] = zone; 1731 else 1732 for (; snum <= end; snum++) 1733 zone_table[ZONETABLE_INDEX(snum, zid)] = zone; 1734 } 1735 1736 #ifndef __HAVE_ARCH_MEMMAP_INIT 1737 #define memmap_init(size, nid, zone, start_pfn) \ 1738 memmap_init_zone((size), (nid), (zone), (start_pfn)) 1739 #endif 1740 1741 static int __devinit zone_batchsize(struct zone *zone) 1742 { 1743 int batch; 1744 1745 /* 1746 * The per-cpu-pages pools are set to around 1000th of the 1747 * size of the zone. But no more than 1/2 of a meg. 1748 * 1749 * OK, so we don't know how big the cache is. So guess. 1750 */ 1751 batch = zone->present_pages / 1024; 1752 if (batch * PAGE_SIZE > 512 * 1024) 1753 batch = (512 * 1024) / PAGE_SIZE; 1754 batch /= 4; /* We effectively *= 4 below */ 1755 if (batch < 1) 1756 batch = 1; 1757 1758 /* 1759 * We will be trying to allcoate bigger chunks of contiguous 1760 * memory of the order of fls(batch). This should result in 1761 * better cache coloring. 1762 * 1763 * A sanity check also to ensure that batch is still in limits. 1764 */ 1765 batch = (1 << fls(batch + batch/2)); 1766 1767 if (fls(batch) >= (PAGE_SHIFT + MAX_ORDER - 2)) 1768 batch = PAGE_SHIFT + ((MAX_ORDER - 1 - PAGE_SHIFT)/2); 1769 1770 return batch; 1771 } 1772 1773 inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 1774 { 1775 struct per_cpu_pages *pcp; 1776 1777 memset(p, 0, sizeof(*p)); 1778 1779 pcp = &p->pcp[0]; /* hot */ 1780 pcp->count = 0; 1781 pcp->low = 0; 1782 pcp->high = 6 * batch; 1783 pcp->batch = max(1UL, 1 * batch); 1784 INIT_LIST_HEAD(&pcp->list); 1785 1786 pcp = &p->pcp[1]; /* cold*/ 1787 pcp->count = 0; 1788 pcp->low = 0; 1789 pcp->high = 2 * batch; 1790 pcp->batch = max(1UL, batch/2); 1791 INIT_LIST_HEAD(&pcp->list); 1792 } 1793 1794 #ifdef CONFIG_NUMA 1795 /* 1796 * Boot pageset table. One per cpu which is going to be used for all 1797 * zones and all nodes. The parameters will be set in such a way 1798 * that an item put on a list will immediately be handed over to 1799 * the buddy list. This is safe since pageset manipulation is done 1800 * with interrupts disabled. 1801 * 1802 * Some NUMA counter updates may also be caught by the boot pagesets. 1803 * 1804 * The boot_pagesets must be kept even after bootup is complete for 1805 * unused processors and/or zones. They do play a role for bootstrapping 1806 * hotplugged processors. 1807 * 1808 * zoneinfo_show() and maybe other functions do 1809 * not check if the processor is online before following the pageset pointer. 1810 * Other parts of the kernel may not check if the zone is available. 1811 */ 1812 static struct per_cpu_pageset 1813 boot_pageset[NR_CPUS]; 1814 1815 /* 1816 * Dynamically allocate memory for the 1817 * per cpu pageset array in struct zone. 1818 */ 1819 static int __devinit process_zones(int cpu) 1820 { 1821 struct zone *zone, *dzone; 1822 1823 for_each_zone(zone) { 1824 1825 zone->pageset[cpu] = kmalloc_node(sizeof(struct per_cpu_pageset), 1826 GFP_KERNEL, cpu_to_node(cpu)); 1827 if (!zone->pageset[cpu]) 1828 goto bad; 1829 1830 setup_pageset(zone->pageset[cpu], zone_batchsize(zone)); 1831 } 1832 1833 return 0; 1834 bad: 1835 for_each_zone(dzone) { 1836 if (dzone == zone) 1837 break; 1838 kfree(dzone->pageset[cpu]); 1839 dzone->pageset[cpu] = NULL; 1840 } 1841 return -ENOMEM; 1842 } 1843 1844 static inline void free_zone_pagesets(int cpu) 1845 { 1846 #ifdef CONFIG_NUMA 1847 struct zone *zone; 1848 1849 for_each_zone(zone) { 1850 struct per_cpu_pageset *pset = zone_pcp(zone, cpu); 1851 1852 zone_pcp(zone, cpu) = NULL; 1853 kfree(pset); 1854 } 1855 #endif 1856 } 1857 1858 static int __devinit pageset_cpuup_callback(struct notifier_block *nfb, 1859 unsigned long action, 1860 void *hcpu) 1861 { 1862 int cpu = (long)hcpu; 1863 int ret = NOTIFY_OK; 1864 1865 switch (action) { 1866 case CPU_UP_PREPARE: 1867 if (process_zones(cpu)) 1868 ret = NOTIFY_BAD; 1869 break; 1870 #ifdef CONFIG_HOTPLUG_CPU 1871 case CPU_DEAD: 1872 free_zone_pagesets(cpu); 1873 break; 1874 #endif 1875 default: 1876 break; 1877 } 1878 return ret; 1879 } 1880 1881 static struct notifier_block pageset_notifier = 1882 { &pageset_cpuup_callback, NULL, 0 }; 1883 1884 void __init setup_per_cpu_pageset() 1885 { 1886 int err; 1887 1888 /* Initialize per_cpu_pageset for cpu 0. 1889 * A cpuup callback will do this for every cpu 1890 * as it comes online 1891 */ 1892 err = process_zones(smp_processor_id()); 1893 BUG_ON(err); 1894 register_cpu_notifier(&pageset_notifier); 1895 } 1896 1897 #endif 1898 1899 static __devinit 1900 void zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 1901 { 1902 int i; 1903 struct pglist_data *pgdat = zone->zone_pgdat; 1904 1905 /* 1906 * The per-page waitqueue mechanism uses hashed waitqueues 1907 * per zone. 1908 */ 1909 zone->wait_table_size = wait_table_size(zone_size_pages); 1910 zone->wait_table_bits = wait_table_bits(zone->wait_table_size); 1911 zone->wait_table = (wait_queue_head_t *) 1912 alloc_bootmem_node(pgdat, zone->wait_table_size 1913 * sizeof(wait_queue_head_t)); 1914 1915 for(i = 0; i < zone->wait_table_size; ++i) 1916 init_waitqueue_head(zone->wait_table + i); 1917 } 1918 1919 static __devinit void zone_pcp_init(struct zone *zone) 1920 { 1921 int cpu; 1922 unsigned long batch = zone_batchsize(zone); 1923 1924 for (cpu = 0; cpu < NR_CPUS; cpu++) { 1925 #ifdef CONFIG_NUMA 1926 /* Early boot. Slab allocator not functional yet */ 1927 zone->pageset[cpu] = &boot_pageset[cpu]; 1928 setup_pageset(&boot_pageset[cpu],0); 1929 #else 1930 setup_pageset(zone_pcp(zone,cpu), batch); 1931 #endif 1932 } 1933 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%lu\n", 1934 zone->name, zone->present_pages, batch); 1935 } 1936 1937 static __devinit void init_currently_empty_zone(struct zone *zone, 1938 unsigned long zone_start_pfn, unsigned long size) 1939 { 1940 struct pglist_data *pgdat = zone->zone_pgdat; 1941 1942 zone_wait_table_init(zone, size); 1943 pgdat->nr_zones = zone_idx(zone) + 1; 1944 1945 zone->zone_mem_map = pfn_to_page(zone_start_pfn); 1946 zone->zone_start_pfn = zone_start_pfn; 1947 1948 memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn); 1949 1950 zone_init_free_lists(pgdat, zone, zone->spanned_pages); 1951 } 1952 1953 /* 1954 * Set up the zone data structures: 1955 * - mark all pages reserved 1956 * - mark all memory queues empty 1957 * - clear the memory bitmaps 1958 */ 1959 static void __init free_area_init_core(struct pglist_data *pgdat, 1960 unsigned long *zones_size, unsigned long *zholes_size) 1961 { 1962 unsigned long j; 1963 int nid = pgdat->node_id; 1964 unsigned long zone_start_pfn = pgdat->node_start_pfn; 1965 1966 pgdat_resize_init(pgdat); 1967 pgdat->nr_zones = 0; 1968 init_waitqueue_head(&pgdat->kswapd_wait); 1969 pgdat->kswapd_max_order = 0; 1970 1971 for (j = 0; j < MAX_NR_ZONES; j++) { 1972 struct zone *zone = pgdat->node_zones + j; 1973 unsigned long size, realsize; 1974 1975 realsize = size = zones_size[j]; 1976 if (zholes_size) 1977 realsize -= zholes_size[j]; 1978 1979 if (j == ZONE_DMA || j == ZONE_NORMAL) 1980 nr_kernel_pages += realsize; 1981 nr_all_pages += realsize; 1982 1983 zone->spanned_pages = size; 1984 zone->present_pages = realsize; 1985 zone->name = zone_names[j]; 1986 spin_lock_init(&zone->lock); 1987 spin_lock_init(&zone->lru_lock); 1988 zone_seqlock_init(zone); 1989 zone->zone_pgdat = pgdat; 1990 zone->free_pages = 0; 1991 1992 zone->temp_priority = zone->prev_priority = DEF_PRIORITY; 1993 1994 zone_pcp_init(zone); 1995 INIT_LIST_HEAD(&zone->active_list); 1996 INIT_LIST_HEAD(&zone->inactive_list); 1997 zone->nr_scan_active = 0; 1998 zone->nr_scan_inactive = 0; 1999 zone->nr_active = 0; 2000 zone->nr_inactive = 0; 2001 atomic_set(&zone->reclaim_in_progress, 0); 2002 if (!size) 2003 continue; 2004 2005 zonetable_add(zone, nid, j, zone_start_pfn, size); 2006 init_currently_empty_zone(zone, zone_start_pfn, size); 2007 zone_start_pfn += size; 2008 } 2009 } 2010 2011 static void __init alloc_node_mem_map(struct pglist_data *pgdat) 2012 { 2013 /* Skip empty nodes */ 2014 if (!pgdat->node_spanned_pages) 2015 return; 2016 2017 #ifdef CONFIG_FLAT_NODE_MEM_MAP 2018 /* ia64 gets its own node_mem_map, before this, without bootmem */ 2019 if (!pgdat->node_mem_map) { 2020 unsigned long size; 2021 struct page *map; 2022 2023 size = (pgdat->node_spanned_pages + 1) * sizeof(struct page); 2024 map = alloc_remap(pgdat->node_id, size); 2025 if (!map) 2026 map = alloc_bootmem_node(pgdat, size); 2027 pgdat->node_mem_map = map; 2028 } 2029 #ifdef CONFIG_FLATMEM 2030 /* 2031 * With no DISCONTIG, the global mem_map is just set as node 0's 2032 */ 2033 if (pgdat == NODE_DATA(0)) 2034 mem_map = NODE_DATA(0)->node_mem_map; 2035 #endif 2036 #endif /* CONFIG_FLAT_NODE_MEM_MAP */ 2037 } 2038 2039 void __init free_area_init_node(int nid, struct pglist_data *pgdat, 2040 unsigned long *zones_size, unsigned long node_start_pfn, 2041 unsigned long *zholes_size) 2042 { 2043 pgdat->node_id = nid; 2044 pgdat->node_start_pfn = node_start_pfn; 2045 calculate_zone_totalpages(pgdat, zones_size, zholes_size); 2046 2047 alloc_node_mem_map(pgdat); 2048 2049 free_area_init_core(pgdat, zones_size, zholes_size); 2050 } 2051 2052 #ifndef CONFIG_NEED_MULTIPLE_NODES 2053 static bootmem_data_t contig_bootmem_data; 2054 struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data }; 2055 2056 EXPORT_SYMBOL(contig_page_data); 2057 #endif 2058 2059 void __init free_area_init(unsigned long *zones_size) 2060 { 2061 free_area_init_node(0, NODE_DATA(0), zones_size, 2062 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 2063 } 2064 2065 #ifdef CONFIG_PROC_FS 2066 2067 #include <linux/seq_file.h> 2068 2069 static void *frag_start(struct seq_file *m, loff_t *pos) 2070 { 2071 pg_data_t *pgdat; 2072 loff_t node = *pos; 2073 2074 for (pgdat = pgdat_list; pgdat && node; pgdat = pgdat->pgdat_next) 2075 --node; 2076 2077 return pgdat; 2078 } 2079 2080 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos) 2081 { 2082 pg_data_t *pgdat = (pg_data_t *)arg; 2083 2084 (*pos)++; 2085 return pgdat->pgdat_next; 2086 } 2087 2088 static void frag_stop(struct seq_file *m, void *arg) 2089 { 2090 } 2091 2092 /* 2093 * This walks the free areas for each zone. 2094 */ 2095 static int frag_show(struct seq_file *m, void *arg) 2096 { 2097 pg_data_t *pgdat = (pg_data_t *)arg; 2098 struct zone *zone; 2099 struct zone *node_zones = pgdat->node_zones; 2100 unsigned long flags; 2101 int order; 2102 2103 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { 2104 if (!zone->present_pages) 2105 continue; 2106 2107 spin_lock_irqsave(&zone->lock, flags); 2108 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); 2109 for (order = 0; order < MAX_ORDER; ++order) 2110 seq_printf(m, "%6lu ", zone->free_area[order].nr_free); 2111 spin_unlock_irqrestore(&zone->lock, flags); 2112 seq_putc(m, '\n'); 2113 } 2114 return 0; 2115 } 2116 2117 struct seq_operations fragmentation_op = { 2118 .start = frag_start, 2119 .next = frag_next, 2120 .stop = frag_stop, 2121 .show = frag_show, 2122 }; 2123 2124 /* 2125 * Output information about zones in @pgdat. 2126 */ 2127 static int zoneinfo_show(struct seq_file *m, void *arg) 2128 { 2129 pg_data_t *pgdat = arg; 2130 struct zone *zone; 2131 struct zone *node_zones = pgdat->node_zones; 2132 unsigned long flags; 2133 2134 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; zone++) { 2135 int i; 2136 2137 if (!zone->present_pages) 2138 continue; 2139 2140 spin_lock_irqsave(&zone->lock, flags); 2141 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name); 2142 seq_printf(m, 2143 "\n pages free %lu" 2144 "\n min %lu" 2145 "\n low %lu" 2146 "\n high %lu" 2147 "\n active %lu" 2148 "\n inactive %lu" 2149 "\n scanned %lu (a: %lu i: %lu)" 2150 "\n spanned %lu" 2151 "\n present %lu", 2152 zone->free_pages, 2153 zone->pages_min, 2154 zone->pages_low, 2155 zone->pages_high, 2156 zone->nr_active, 2157 zone->nr_inactive, 2158 zone->pages_scanned, 2159 zone->nr_scan_active, zone->nr_scan_inactive, 2160 zone->spanned_pages, 2161 zone->present_pages); 2162 seq_printf(m, 2163 "\n protection: (%lu", 2164 zone->lowmem_reserve[0]); 2165 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++) 2166 seq_printf(m, ", %lu", zone->lowmem_reserve[i]); 2167 seq_printf(m, 2168 ")" 2169 "\n pagesets"); 2170 for (i = 0; i < ARRAY_SIZE(zone->pageset); i++) { 2171 struct per_cpu_pageset *pageset; 2172 int j; 2173 2174 pageset = zone_pcp(zone, i); 2175 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) { 2176 if (pageset->pcp[j].count) 2177 break; 2178 } 2179 if (j == ARRAY_SIZE(pageset->pcp)) 2180 continue; 2181 for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) { 2182 seq_printf(m, 2183 "\n cpu: %i pcp: %i" 2184 "\n count: %i" 2185 "\n low: %i" 2186 "\n high: %i" 2187 "\n batch: %i", 2188 i, j, 2189 pageset->pcp[j].count, 2190 pageset->pcp[j].low, 2191 pageset->pcp[j].high, 2192 pageset->pcp[j].batch); 2193 } 2194 #ifdef CONFIG_NUMA 2195 seq_printf(m, 2196 "\n numa_hit: %lu" 2197 "\n numa_miss: %lu" 2198 "\n numa_foreign: %lu" 2199 "\n interleave_hit: %lu" 2200 "\n local_node: %lu" 2201 "\n other_node: %lu", 2202 pageset->numa_hit, 2203 pageset->numa_miss, 2204 pageset->numa_foreign, 2205 pageset->interleave_hit, 2206 pageset->local_node, 2207 pageset->other_node); 2208 #endif 2209 } 2210 seq_printf(m, 2211 "\n all_unreclaimable: %u" 2212 "\n prev_priority: %i" 2213 "\n temp_priority: %i" 2214 "\n start_pfn: %lu", 2215 zone->all_unreclaimable, 2216 zone->prev_priority, 2217 zone->temp_priority, 2218 zone->zone_start_pfn); 2219 spin_unlock_irqrestore(&zone->lock, flags); 2220 seq_putc(m, '\n'); 2221 } 2222 return 0; 2223 } 2224 2225 struct seq_operations zoneinfo_op = { 2226 .start = frag_start, /* iterate over all zones. The same as in 2227 * fragmentation. */ 2228 .next = frag_next, 2229 .stop = frag_stop, 2230 .show = zoneinfo_show, 2231 }; 2232 2233 static char *vmstat_text[] = { 2234 "nr_dirty", 2235 "nr_writeback", 2236 "nr_unstable", 2237 "nr_page_table_pages", 2238 "nr_mapped", 2239 "nr_slab", 2240 2241 "pgpgin", 2242 "pgpgout", 2243 "pswpin", 2244 "pswpout", 2245 "pgalloc_high", 2246 2247 "pgalloc_normal", 2248 "pgalloc_dma", 2249 "pgfree", 2250 "pgactivate", 2251 "pgdeactivate", 2252 2253 "pgfault", 2254 "pgmajfault", 2255 "pgrefill_high", 2256 "pgrefill_normal", 2257 "pgrefill_dma", 2258 2259 "pgsteal_high", 2260 "pgsteal_normal", 2261 "pgsteal_dma", 2262 "pgscan_kswapd_high", 2263 "pgscan_kswapd_normal", 2264 2265 "pgscan_kswapd_dma", 2266 "pgscan_direct_high", 2267 "pgscan_direct_normal", 2268 "pgscan_direct_dma", 2269 "pginodesteal", 2270 2271 "slabs_scanned", 2272 "kswapd_steal", 2273 "kswapd_inodesteal", 2274 "pageoutrun", 2275 "allocstall", 2276 2277 "pgrotated", 2278 "nr_bounce", 2279 }; 2280 2281 static void *vmstat_start(struct seq_file *m, loff_t *pos) 2282 { 2283 struct page_state *ps; 2284 2285 if (*pos >= ARRAY_SIZE(vmstat_text)) 2286 return NULL; 2287 2288 ps = kmalloc(sizeof(*ps), GFP_KERNEL); 2289 m->private = ps; 2290 if (!ps) 2291 return ERR_PTR(-ENOMEM); 2292 get_full_page_state(ps); 2293 ps->pgpgin /= 2; /* sectors -> kbytes */ 2294 ps->pgpgout /= 2; 2295 return (unsigned long *)ps + *pos; 2296 } 2297 2298 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos) 2299 { 2300 (*pos)++; 2301 if (*pos >= ARRAY_SIZE(vmstat_text)) 2302 return NULL; 2303 return (unsigned long *)m->private + *pos; 2304 } 2305 2306 static int vmstat_show(struct seq_file *m, void *arg) 2307 { 2308 unsigned long *l = arg; 2309 unsigned long off = l - (unsigned long *)m->private; 2310 2311 seq_printf(m, "%s %lu\n", vmstat_text[off], *l); 2312 return 0; 2313 } 2314 2315 static void vmstat_stop(struct seq_file *m, void *arg) 2316 { 2317 kfree(m->private); 2318 m->private = NULL; 2319 } 2320 2321 struct seq_operations vmstat_op = { 2322 .start = vmstat_start, 2323 .next = vmstat_next, 2324 .stop = vmstat_stop, 2325 .show = vmstat_show, 2326 }; 2327 2328 #endif /* CONFIG_PROC_FS */ 2329 2330 #ifdef CONFIG_HOTPLUG_CPU 2331 static int page_alloc_cpu_notify(struct notifier_block *self, 2332 unsigned long action, void *hcpu) 2333 { 2334 int cpu = (unsigned long)hcpu; 2335 long *count; 2336 unsigned long *src, *dest; 2337 2338 if (action == CPU_DEAD) { 2339 int i; 2340 2341 /* Drain local pagecache count. */ 2342 count = &per_cpu(nr_pagecache_local, cpu); 2343 atomic_add(*count, &nr_pagecache); 2344 *count = 0; 2345 local_irq_disable(); 2346 __drain_pages(cpu); 2347 2348 /* Add dead cpu's page_states to our own. */ 2349 dest = (unsigned long *)&__get_cpu_var(page_states); 2350 src = (unsigned long *)&per_cpu(page_states, cpu); 2351 2352 for (i = 0; i < sizeof(struct page_state)/sizeof(unsigned long); 2353 i++) { 2354 dest[i] += src[i]; 2355 src[i] = 0; 2356 } 2357 2358 local_irq_enable(); 2359 } 2360 return NOTIFY_OK; 2361 } 2362 #endif /* CONFIG_HOTPLUG_CPU */ 2363 2364 void __init page_alloc_init(void) 2365 { 2366 hotcpu_notifier(page_alloc_cpu_notify, 0); 2367 } 2368 2369 /* 2370 * setup_per_zone_lowmem_reserve - called whenever 2371 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 2372 * has a correct pages reserved value, so an adequate number of 2373 * pages are left in the zone after a successful __alloc_pages(). 2374 */ 2375 static void setup_per_zone_lowmem_reserve(void) 2376 { 2377 struct pglist_data *pgdat; 2378 int j, idx; 2379 2380 for_each_pgdat(pgdat) { 2381 for (j = 0; j < MAX_NR_ZONES; j++) { 2382 struct zone *zone = pgdat->node_zones + j; 2383 unsigned long present_pages = zone->present_pages; 2384 2385 zone->lowmem_reserve[j] = 0; 2386 2387 for (idx = j-1; idx >= 0; idx--) { 2388 struct zone *lower_zone; 2389 2390 if (sysctl_lowmem_reserve_ratio[idx] < 1) 2391 sysctl_lowmem_reserve_ratio[idx] = 1; 2392 2393 lower_zone = pgdat->node_zones + idx; 2394 lower_zone->lowmem_reserve[j] = present_pages / 2395 sysctl_lowmem_reserve_ratio[idx]; 2396 present_pages += lower_zone->present_pages; 2397 } 2398 } 2399 } 2400 } 2401 2402 /* 2403 * setup_per_zone_pages_min - called when min_free_kbytes changes. Ensures 2404 * that the pages_{min,low,high} values for each zone are set correctly 2405 * with respect to min_free_kbytes. 2406 */ 2407 void setup_per_zone_pages_min(void) 2408 { 2409 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 2410 unsigned long lowmem_pages = 0; 2411 struct zone *zone; 2412 unsigned long flags; 2413 2414 /* Calculate total number of !ZONE_HIGHMEM pages */ 2415 for_each_zone(zone) { 2416 if (!is_highmem(zone)) 2417 lowmem_pages += zone->present_pages; 2418 } 2419 2420 for_each_zone(zone) { 2421 spin_lock_irqsave(&zone->lru_lock, flags); 2422 if (is_highmem(zone)) { 2423 /* 2424 * Often, highmem doesn't need to reserve any pages. 2425 * But the pages_min/low/high values are also used for 2426 * batching up page reclaim activity so we need a 2427 * decent value here. 2428 */ 2429 int min_pages; 2430 2431 min_pages = zone->present_pages / 1024; 2432 if (min_pages < SWAP_CLUSTER_MAX) 2433 min_pages = SWAP_CLUSTER_MAX; 2434 if (min_pages > 128) 2435 min_pages = 128; 2436 zone->pages_min = min_pages; 2437 } else { 2438 /* if it's a lowmem zone, reserve a number of pages 2439 * proportionate to the zone's size. 2440 */ 2441 zone->pages_min = (pages_min * zone->present_pages) / 2442 lowmem_pages; 2443 } 2444 2445 /* 2446 * When interpreting these watermarks, just keep in mind that: 2447 * zone->pages_min == (zone->pages_min * 4) / 4; 2448 */ 2449 zone->pages_low = (zone->pages_min * 5) / 4; 2450 zone->pages_high = (zone->pages_min * 6) / 4; 2451 spin_unlock_irqrestore(&zone->lru_lock, flags); 2452 } 2453 } 2454 2455 /* 2456 * Initialise min_free_kbytes. 2457 * 2458 * For small machines we want it small (128k min). For large machines 2459 * we want it large (64MB max). But it is not linear, because network 2460 * bandwidth does not increase linearly with machine size. We use 2461 * 2462 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 2463 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 2464 * 2465 * which yields 2466 * 2467 * 16MB: 512k 2468 * 32MB: 724k 2469 * 64MB: 1024k 2470 * 128MB: 1448k 2471 * 256MB: 2048k 2472 * 512MB: 2896k 2473 * 1024MB: 4096k 2474 * 2048MB: 5792k 2475 * 4096MB: 8192k 2476 * 8192MB: 11584k 2477 * 16384MB: 16384k 2478 */ 2479 static int __init init_per_zone_pages_min(void) 2480 { 2481 unsigned long lowmem_kbytes; 2482 2483 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 2484 2485 min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 2486 if (min_free_kbytes < 128) 2487 min_free_kbytes = 128; 2488 if (min_free_kbytes > 65536) 2489 min_free_kbytes = 65536; 2490 setup_per_zone_pages_min(); 2491 setup_per_zone_lowmem_reserve(); 2492 return 0; 2493 } 2494 module_init(init_per_zone_pages_min) 2495 2496 /* 2497 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 2498 * that we can call two helper functions whenever min_free_kbytes 2499 * changes. 2500 */ 2501 int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 2502 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 2503 { 2504 proc_dointvec(table, write, file, buffer, length, ppos); 2505 setup_per_zone_pages_min(); 2506 return 0; 2507 } 2508 2509 /* 2510 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 2511 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 2512 * whenever sysctl_lowmem_reserve_ratio changes. 2513 * 2514 * The reserve ratio obviously has absolutely no relation with the 2515 * pages_min watermarks. The lowmem reserve ratio can only make sense 2516 * if in function of the boot time zone sizes. 2517 */ 2518 int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, 2519 struct file *file, void __user *buffer, size_t *length, loff_t *ppos) 2520 { 2521 proc_dointvec_minmax(table, write, file, buffer, length, ppos); 2522 setup_per_zone_lowmem_reserve(); 2523 return 0; 2524 } 2525 2526 __initdata int hashdist = HASHDIST_DEFAULT; 2527 2528 #ifdef CONFIG_NUMA 2529 static int __init set_hashdist(char *str) 2530 { 2531 if (!str) 2532 return 0; 2533 hashdist = simple_strtoul(str, &str, 0); 2534 return 1; 2535 } 2536 __setup("hashdist=", set_hashdist); 2537 #endif 2538 2539 /* 2540 * allocate a large system hash table from bootmem 2541 * - it is assumed that the hash table must contain an exact power-of-2 2542 * quantity of entries 2543 * - limit is the number of hash buckets, not the total allocation size 2544 */ 2545 void *__init alloc_large_system_hash(const char *tablename, 2546 unsigned long bucketsize, 2547 unsigned long numentries, 2548 int scale, 2549 int flags, 2550 unsigned int *_hash_shift, 2551 unsigned int *_hash_mask, 2552 unsigned long limit) 2553 { 2554 unsigned long long max = limit; 2555 unsigned long log2qty, size; 2556 void *table = NULL; 2557 2558 /* allow the kernel cmdline to have a say */ 2559 if (!numentries) { 2560 /* round applicable memory size up to nearest megabyte */ 2561 numentries = (flags & HASH_HIGHMEM) ? nr_all_pages : nr_kernel_pages; 2562 numentries += (1UL << (20 - PAGE_SHIFT)) - 1; 2563 numentries >>= 20 - PAGE_SHIFT; 2564 numentries <<= 20 - PAGE_SHIFT; 2565 2566 /* limit to 1 bucket per 2^scale bytes of low memory */ 2567 if (scale > PAGE_SHIFT) 2568 numentries >>= (scale - PAGE_SHIFT); 2569 else 2570 numentries <<= (PAGE_SHIFT - scale); 2571 } 2572 /* rounded up to nearest power of 2 in size */ 2573 numentries = 1UL << (long_log2(numentries) + 1); 2574 2575 /* limit allocation size to 1/16 total memory by default */ 2576 if (max == 0) { 2577 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 2578 do_div(max, bucketsize); 2579 } 2580 2581 if (numentries > max) 2582 numentries = max; 2583 2584 log2qty = long_log2(numentries); 2585 2586 do { 2587 size = bucketsize << log2qty; 2588 if (flags & HASH_EARLY) 2589 table = alloc_bootmem(size); 2590 else if (hashdist) 2591 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 2592 else { 2593 unsigned long order; 2594 for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++) 2595 ; 2596 table = (void*) __get_free_pages(GFP_ATOMIC, order); 2597 } 2598 } while (!table && size > PAGE_SIZE && --log2qty); 2599 2600 if (!table) 2601 panic("Failed to allocate %s hash table\n", tablename); 2602 2603 printk("%s hash table entries: %d (order: %d, %lu bytes)\n", 2604 tablename, 2605 (1U << log2qty), 2606 long_log2(size) - PAGE_SHIFT, 2607 size); 2608 2609 if (_hash_shift) 2610 *_hash_shift = log2qty; 2611 if (_hash_mask) 2612 *_hash_mask = (1 << log2qty) - 1; 2613 2614 return table; 2615 } 2616