1 /* 2 * linux/mm/page_alloc.c 3 * 4 * Manages the free list, the system allocates free pages here. 5 * Note that kmalloc() lives in slab.c 6 * 7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 8 * Swap reorganised 29.12.95, Stephen Tweedie 9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999 11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999 12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000 13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002 14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton) 15 */ 16 17 #include <linux/stddef.h> 18 #include <linux/mm.h> 19 #include <linux/swap.h> 20 #include <linux/interrupt.h> 21 #include <linux/pagemap.h> 22 #include <linux/jiffies.h> 23 #include <linux/bootmem.h> 24 #include <linux/memblock.h> 25 #include <linux/compiler.h> 26 #include <linux/kernel.h> 27 #include <linux/kmemcheck.h> 28 #include <linux/module.h> 29 #include <linux/suspend.h> 30 #include <linux/pagevec.h> 31 #include <linux/blkdev.h> 32 #include <linux/slab.h> 33 #include <linux/ratelimit.h> 34 #include <linux/oom.h> 35 #include <linux/notifier.h> 36 #include <linux/topology.h> 37 #include <linux/sysctl.h> 38 #include <linux/cpu.h> 39 #include <linux/cpuset.h> 40 #include <linux/memory_hotplug.h> 41 #include <linux/nodemask.h> 42 #include <linux/vmalloc.h> 43 #include <linux/vmstat.h> 44 #include <linux/mempolicy.h> 45 #include <linux/stop_machine.h> 46 #include <linux/sort.h> 47 #include <linux/pfn.h> 48 #include <linux/backing-dev.h> 49 #include <linux/fault-inject.h> 50 #include <linux/page-isolation.h> 51 #include <linux/page_cgroup.h> 52 #include <linux/debugobjects.h> 53 #include <linux/kmemleak.h> 54 #include <linux/compaction.h> 55 #include <trace/events/kmem.h> 56 #include <linux/ftrace_event.h> 57 #include <linux/memcontrol.h> 58 #include <linux/prefetch.h> 59 #include <linux/migrate.h> 60 #include <linux/page-debug-flags.h> 61 62 #include <asm/tlbflush.h> 63 #include <asm/div64.h> 64 #include "internal.h" 65 66 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID 67 DEFINE_PER_CPU(int, numa_node); 68 EXPORT_PER_CPU_SYMBOL(numa_node); 69 #endif 70 71 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 72 /* 73 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly. 74 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined. 75 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem() 76 * defined in <linux/topology.h>. 77 */ 78 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */ 79 EXPORT_PER_CPU_SYMBOL(_numa_mem_); 80 #endif 81 82 /* 83 * Array of node states. 84 */ 85 nodemask_t node_states[NR_NODE_STATES] __read_mostly = { 86 [N_POSSIBLE] = NODE_MASK_ALL, 87 [N_ONLINE] = { { [0] = 1UL } }, 88 #ifndef CONFIG_NUMA 89 [N_NORMAL_MEMORY] = { { [0] = 1UL } }, 90 #ifdef CONFIG_HIGHMEM 91 [N_HIGH_MEMORY] = { { [0] = 1UL } }, 92 #endif 93 #ifdef CONFIG_MOVABLE_NODE 94 [N_MEMORY] = { { [0] = 1UL } }, 95 #endif 96 [N_CPU] = { { [0] = 1UL } }, 97 #endif /* NUMA */ 98 }; 99 EXPORT_SYMBOL(node_states); 100 101 unsigned long totalram_pages __read_mostly; 102 unsigned long totalreserve_pages __read_mostly; 103 /* 104 * When calculating the number of globally allowed dirty pages, there 105 * is a certain number of per-zone reserves that should not be 106 * considered dirtyable memory. This is the sum of those reserves 107 * over all existing zones that contribute dirtyable memory. 108 */ 109 unsigned long dirty_balance_reserve __read_mostly; 110 111 int percpu_pagelist_fraction; 112 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; 113 114 #ifdef CONFIG_PM_SLEEP 115 /* 116 * The following functions are used by the suspend/hibernate code to temporarily 117 * change gfp_allowed_mask in order to avoid using I/O during memory allocations 118 * while devices are suspended. To avoid races with the suspend/hibernate code, 119 * they should always be called with pm_mutex held (gfp_allowed_mask also should 120 * only be modified with pm_mutex held, unless the suspend/hibernate code is 121 * guaranteed not to run in parallel with that modification). 122 */ 123 124 static gfp_t saved_gfp_mask; 125 126 void pm_restore_gfp_mask(void) 127 { 128 WARN_ON(!mutex_is_locked(&pm_mutex)); 129 if (saved_gfp_mask) { 130 gfp_allowed_mask = saved_gfp_mask; 131 saved_gfp_mask = 0; 132 } 133 } 134 135 void pm_restrict_gfp_mask(void) 136 { 137 WARN_ON(!mutex_is_locked(&pm_mutex)); 138 WARN_ON(saved_gfp_mask); 139 saved_gfp_mask = gfp_allowed_mask; 140 gfp_allowed_mask &= ~GFP_IOFS; 141 } 142 143 bool pm_suspended_storage(void) 144 { 145 if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS) 146 return false; 147 return true; 148 } 149 #endif /* CONFIG_PM_SLEEP */ 150 151 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 152 int pageblock_order __read_mostly; 153 #endif 154 155 static void __free_pages_ok(struct page *page, unsigned int order); 156 157 /* 158 * results with 256, 32 in the lowmem_reserve sysctl: 159 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) 160 * 1G machine -> (16M dma, 784M normal, 224M high) 161 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA 162 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL 163 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA 164 * 165 * TBD: should special case ZONE_DMA32 machines here - in those we normally 166 * don't need any ZONE_NORMAL reservation 167 */ 168 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 169 #ifdef CONFIG_ZONE_DMA 170 256, 171 #endif 172 #ifdef CONFIG_ZONE_DMA32 173 256, 174 #endif 175 #ifdef CONFIG_HIGHMEM 176 32, 177 #endif 178 32, 179 }; 180 181 EXPORT_SYMBOL(totalram_pages); 182 183 static char * const zone_names[MAX_NR_ZONES] = { 184 #ifdef CONFIG_ZONE_DMA 185 "DMA", 186 #endif 187 #ifdef CONFIG_ZONE_DMA32 188 "DMA32", 189 #endif 190 "Normal", 191 #ifdef CONFIG_HIGHMEM 192 "HighMem", 193 #endif 194 "Movable", 195 }; 196 197 int min_free_kbytes = 1024; 198 199 static unsigned long __meminitdata nr_kernel_pages; 200 static unsigned long __meminitdata nr_all_pages; 201 static unsigned long __meminitdata dma_reserve; 202 203 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 204 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; 205 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; 206 static unsigned long __initdata required_kernelcore; 207 static unsigned long __initdata required_movablecore; 208 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES]; 209 210 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ 211 int movable_zone; 212 EXPORT_SYMBOL(movable_zone); 213 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 214 215 #if MAX_NUMNODES > 1 216 int nr_node_ids __read_mostly = MAX_NUMNODES; 217 int nr_online_nodes __read_mostly = 1; 218 EXPORT_SYMBOL(nr_node_ids); 219 EXPORT_SYMBOL(nr_online_nodes); 220 #endif 221 222 int page_group_by_mobility_disabled __read_mostly; 223 224 void set_pageblock_migratetype(struct page *page, int migratetype) 225 { 226 227 if (unlikely(page_group_by_mobility_disabled)) 228 migratetype = MIGRATE_UNMOVABLE; 229 230 set_pageblock_flags_group(page, (unsigned long)migratetype, 231 PB_migrate, PB_migrate_end); 232 } 233 234 bool oom_killer_disabled __read_mostly; 235 236 #ifdef CONFIG_DEBUG_VM 237 static int page_outside_zone_boundaries(struct zone *zone, struct page *page) 238 { 239 int ret = 0; 240 unsigned seq; 241 unsigned long pfn = page_to_pfn(page); 242 243 do { 244 seq = zone_span_seqbegin(zone); 245 if (pfn >= zone->zone_start_pfn + zone->spanned_pages) 246 ret = 1; 247 else if (pfn < zone->zone_start_pfn) 248 ret = 1; 249 } while (zone_span_seqretry(zone, seq)); 250 251 return ret; 252 } 253 254 static int page_is_consistent(struct zone *zone, struct page *page) 255 { 256 if (!pfn_valid_within(page_to_pfn(page))) 257 return 0; 258 if (zone != page_zone(page)) 259 return 0; 260 261 return 1; 262 } 263 /* 264 * Temporary debugging check for pages not lying within a given zone. 265 */ 266 static int bad_range(struct zone *zone, struct page *page) 267 { 268 if (page_outside_zone_boundaries(zone, page)) 269 return 1; 270 if (!page_is_consistent(zone, page)) 271 return 1; 272 273 return 0; 274 } 275 #else 276 static inline int bad_range(struct zone *zone, struct page *page) 277 { 278 return 0; 279 } 280 #endif 281 282 static void bad_page(struct page *page) 283 { 284 static unsigned long resume; 285 static unsigned long nr_shown; 286 static unsigned long nr_unshown; 287 288 /* Don't complain about poisoned pages */ 289 if (PageHWPoison(page)) { 290 reset_page_mapcount(page); /* remove PageBuddy */ 291 return; 292 } 293 294 /* 295 * Allow a burst of 60 reports, then keep quiet for that minute; 296 * or allow a steady drip of one report per second. 297 */ 298 if (nr_shown == 60) { 299 if (time_before(jiffies, resume)) { 300 nr_unshown++; 301 goto out; 302 } 303 if (nr_unshown) { 304 printk(KERN_ALERT 305 "BUG: Bad page state: %lu messages suppressed\n", 306 nr_unshown); 307 nr_unshown = 0; 308 } 309 nr_shown = 0; 310 } 311 if (nr_shown++ == 0) 312 resume = jiffies + 60 * HZ; 313 314 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n", 315 current->comm, page_to_pfn(page)); 316 dump_page(page); 317 318 print_modules(); 319 dump_stack(); 320 out: 321 /* Leave bad fields for debug, except PageBuddy could make trouble */ 322 reset_page_mapcount(page); /* remove PageBuddy */ 323 add_taint(TAINT_BAD_PAGE); 324 } 325 326 /* 327 * Higher-order pages are called "compound pages". They are structured thusly: 328 * 329 * The first PAGE_SIZE page is called the "head page". 330 * 331 * The remaining PAGE_SIZE pages are called "tail pages". 332 * 333 * All pages have PG_compound set. All tail pages have their ->first_page 334 * pointing at the head page. 335 * 336 * The first tail page's ->lru.next holds the address of the compound page's 337 * put_page() function. Its ->lru.prev holds the order of allocation. 338 * This usage means that zero-order pages may not be compound. 339 */ 340 341 static void free_compound_page(struct page *page) 342 { 343 __free_pages_ok(page, compound_order(page)); 344 } 345 346 void prep_compound_page(struct page *page, unsigned long order) 347 { 348 int i; 349 int nr_pages = 1 << order; 350 351 set_compound_page_dtor(page, free_compound_page); 352 set_compound_order(page, order); 353 __SetPageHead(page); 354 for (i = 1; i < nr_pages; i++) { 355 struct page *p = page + i; 356 __SetPageTail(p); 357 set_page_count(p, 0); 358 p->first_page = page; 359 } 360 } 361 362 /* update __split_huge_page_refcount if you change this function */ 363 static int destroy_compound_page(struct page *page, unsigned long order) 364 { 365 int i; 366 int nr_pages = 1 << order; 367 int bad = 0; 368 369 if (unlikely(compound_order(page) != order)) { 370 bad_page(page); 371 bad++; 372 } 373 374 __ClearPageHead(page); 375 376 for (i = 1; i < nr_pages; i++) { 377 struct page *p = page + i; 378 379 if (unlikely(!PageTail(p) || (p->first_page != page))) { 380 bad_page(page); 381 bad++; 382 } 383 __ClearPageTail(p); 384 } 385 386 return bad; 387 } 388 389 static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags) 390 { 391 int i; 392 393 /* 394 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO 395 * and __GFP_HIGHMEM from hard or soft interrupt context. 396 */ 397 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); 398 for (i = 0; i < (1 << order); i++) 399 clear_highpage(page + i); 400 } 401 402 #ifdef CONFIG_DEBUG_PAGEALLOC 403 unsigned int _debug_guardpage_minorder; 404 405 static int __init debug_guardpage_minorder_setup(char *buf) 406 { 407 unsigned long res; 408 409 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) { 410 printk(KERN_ERR "Bad debug_guardpage_minorder value\n"); 411 return 0; 412 } 413 _debug_guardpage_minorder = res; 414 printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res); 415 return 0; 416 } 417 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup); 418 419 static inline void set_page_guard_flag(struct page *page) 420 { 421 __set_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags); 422 } 423 424 static inline void clear_page_guard_flag(struct page *page) 425 { 426 __clear_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags); 427 } 428 #else 429 static inline void set_page_guard_flag(struct page *page) { } 430 static inline void clear_page_guard_flag(struct page *page) { } 431 #endif 432 433 static inline void set_page_order(struct page *page, int order) 434 { 435 set_page_private(page, order); 436 __SetPageBuddy(page); 437 } 438 439 static inline void rmv_page_order(struct page *page) 440 { 441 __ClearPageBuddy(page); 442 set_page_private(page, 0); 443 } 444 445 /* 446 * Locate the struct page for both the matching buddy in our 447 * pair (buddy1) and the combined O(n+1) page they form (page). 448 * 449 * 1) Any buddy B1 will have an order O twin B2 which satisfies 450 * the following equation: 451 * B2 = B1 ^ (1 << O) 452 * For example, if the starting buddy (buddy2) is #8 its order 453 * 1 buddy is #10: 454 * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 455 * 456 * 2) Any buddy B will have an order O+1 parent P which 457 * satisfies the following equation: 458 * P = B & ~(1 << O) 459 * 460 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER 461 */ 462 static inline unsigned long 463 __find_buddy_index(unsigned long page_idx, unsigned int order) 464 { 465 return page_idx ^ (1 << order); 466 } 467 468 /* 469 * This function checks whether a page is free && is the buddy 470 * we can do coalesce a page and its buddy if 471 * (a) the buddy is not in a hole && 472 * (b) the buddy is in the buddy system && 473 * (c) a page and its buddy have the same order && 474 * (d) a page and its buddy are in the same zone. 475 * 476 * For recording whether a page is in the buddy system, we set ->_mapcount -2. 477 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock. 478 * 479 * For recording page's order, we use page_private(page). 480 */ 481 static inline int page_is_buddy(struct page *page, struct page *buddy, 482 int order) 483 { 484 if (!pfn_valid_within(page_to_pfn(buddy))) 485 return 0; 486 487 if (page_zone_id(page) != page_zone_id(buddy)) 488 return 0; 489 490 if (page_is_guard(buddy) && page_order(buddy) == order) { 491 VM_BUG_ON(page_count(buddy) != 0); 492 return 1; 493 } 494 495 if (PageBuddy(buddy) && page_order(buddy) == order) { 496 VM_BUG_ON(page_count(buddy) != 0); 497 return 1; 498 } 499 return 0; 500 } 501 502 /* 503 * Freeing function for a buddy system allocator. 504 * 505 * The concept of a buddy system is to maintain direct-mapped table 506 * (containing bit values) for memory blocks of various "orders". 507 * The bottom level table contains the map for the smallest allocatable 508 * units of memory (here, pages), and each level above it describes 509 * pairs of units from the levels below, hence, "buddies". 510 * At a high level, all that happens here is marking the table entry 511 * at the bottom level available, and propagating the changes upward 512 * as necessary, plus some accounting needed to play nicely with other 513 * parts of the VM system. 514 * At each level, we keep a list of pages, which are heads of continuous 515 * free pages of length of (1 << order) and marked with _mapcount -2. Page's 516 * order is recorded in page_private(page) field. 517 * So when we are allocating or freeing one, we can derive the state of the 518 * other. That is, if we allocate a small block, and both were 519 * free, the remainder of the region must be split into blocks. 520 * If a block is freed, and its buddy is also free, then this 521 * triggers coalescing into a block of larger size. 522 * 523 * -- nyc 524 */ 525 526 static inline void __free_one_page(struct page *page, 527 struct zone *zone, unsigned int order, 528 int migratetype) 529 { 530 unsigned long page_idx; 531 unsigned long combined_idx; 532 unsigned long uninitialized_var(buddy_idx); 533 struct page *buddy; 534 535 if (unlikely(PageCompound(page))) 536 if (unlikely(destroy_compound_page(page, order))) 537 return; 538 539 VM_BUG_ON(migratetype == -1); 540 541 page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); 542 543 VM_BUG_ON(page_idx & ((1 << order) - 1)); 544 VM_BUG_ON(bad_range(zone, page)); 545 546 while (order < MAX_ORDER-1) { 547 buddy_idx = __find_buddy_index(page_idx, order); 548 buddy = page + (buddy_idx - page_idx); 549 if (!page_is_buddy(page, buddy, order)) 550 break; 551 /* 552 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page, 553 * merge with it and move up one order. 554 */ 555 if (page_is_guard(buddy)) { 556 clear_page_guard_flag(buddy); 557 set_page_private(page, 0); 558 __mod_zone_freepage_state(zone, 1 << order, 559 migratetype); 560 } else { 561 list_del(&buddy->lru); 562 zone->free_area[order].nr_free--; 563 rmv_page_order(buddy); 564 } 565 combined_idx = buddy_idx & page_idx; 566 page = page + (combined_idx - page_idx); 567 page_idx = combined_idx; 568 order++; 569 } 570 set_page_order(page, order); 571 572 /* 573 * If this is not the largest possible page, check if the buddy 574 * of the next-highest order is free. If it is, it's possible 575 * that pages are being freed that will coalesce soon. In case, 576 * that is happening, add the free page to the tail of the list 577 * so it's less likely to be used soon and more likely to be merged 578 * as a higher order page 579 */ 580 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) { 581 struct page *higher_page, *higher_buddy; 582 combined_idx = buddy_idx & page_idx; 583 higher_page = page + (combined_idx - page_idx); 584 buddy_idx = __find_buddy_index(combined_idx, order + 1); 585 higher_buddy = higher_page + (buddy_idx - combined_idx); 586 if (page_is_buddy(higher_page, higher_buddy, order + 1)) { 587 list_add_tail(&page->lru, 588 &zone->free_area[order].free_list[migratetype]); 589 goto out; 590 } 591 } 592 593 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]); 594 out: 595 zone->free_area[order].nr_free++; 596 } 597 598 static inline int free_pages_check(struct page *page) 599 { 600 if (unlikely(page_mapcount(page) | 601 (page->mapping != NULL) | 602 (atomic_read(&page->_count) != 0) | 603 (page->flags & PAGE_FLAGS_CHECK_AT_FREE) | 604 (mem_cgroup_bad_page_check(page)))) { 605 bad_page(page); 606 return 1; 607 } 608 reset_page_last_nid(page); 609 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP) 610 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; 611 return 0; 612 } 613 614 /* 615 * Frees a number of pages from the PCP lists 616 * Assumes all pages on list are in same zone, and of same order. 617 * count is the number of pages to free. 618 * 619 * If the zone was previously in an "all pages pinned" state then look to 620 * see if this freeing clears that state. 621 * 622 * And clear the zone's pages_scanned counter, to hold off the "all pages are 623 * pinned" detection logic. 624 */ 625 static void free_pcppages_bulk(struct zone *zone, int count, 626 struct per_cpu_pages *pcp) 627 { 628 int migratetype = 0; 629 int batch_free = 0; 630 int to_free = count; 631 632 spin_lock(&zone->lock); 633 zone->all_unreclaimable = 0; 634 zone->pages_scanned = 0; 635 636 while (to_free) { 637 struct page *page; 638 struct list_head *list; 639 640 /* 641 * Remove pages from lists in a round-robin fashion. A 642 * batch_free count is maintained that is incremented when an 643 * empty list is encountered. This is so more pages are freed 644 * off fuller lists instead of spinning excessively around empty 645 * lists 646 */ 647 do { 648 batch_free++; 649 if (++migratetype == MIGRATE_PCPTYPES) 650 migratetype = 0; 651 list = &pcp->lists[migratetype]; 652 } while (list_empty(list)); 653 654 /* This is the only non-empty list. Free them all. */ 655 if (batch_free == MIGRATE_PCPTYPES) 656 batch_free = to_free; 657 658 do { 659 int mt; /* migratetype of the to-be-freed page */ 660 661 page = list_entry(list->prev, struct page, lru); 662 /* must delete as __free_one_page list manipulates */ 663 list_del(&page->lru); 664 mt = get_freepage_migratetype(page); 665 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */ 666 __free_one_page(page, zone, 0, mt); 667 trace_mm_page_pcpu_drain(page, 0, mt); 668 if (likely(get_pageblock_migratetype(page) != MIGRATE_ISOLATE)) { 669 __mod_zone_page_state(zone, NR_FREE_PAGES, 1); 670 if (is_migrate_cma(mt)) 671 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1); 672 } 673 } while (--to_free && --batch_free && !list_empty(list)); 674 } 675 spin_unlock(&zone->lock); 676 } 677 678 static void free_one_page(struct zone *zone, struct page *page, int order, 679 int migratetype) 680 { 681 spin_lock(&zone->lock); 682 zone->all_unreclaimable = 0; 683 zone->pages_scanned = 0; 684 685 __free_one_page(page, zone, order, migratetype); 686 if (unlikely(migratetype != MIGRATE_ISOLATE)) 687 __mod_zone_freepage_state(zone, 1 << order, migratetype); 688 spin_unlock(&zone->lock); 689 } 690 691 static bool free_pages_prepare(struct page *page, unsigned int order) 692 { 693 int i; 694 int bad = 0; 695 696 trace_mm_page_free(page, order); 697 kmemcheck_free_shadow(page, order); 698 699 if (PageAnon(page)) 700 page->mapping = NULL; 701 for (i = 0; i < (1 << order); i++) 702 bad += free_pages_check(page + i); 703 if (bad) 704 return false; 705 706 if (!PageHighMem(page)) { 707 debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order); 708 debug_check_no_obj_freed(page_address(page), 709 PAGE_SIZE << order); 710 } 711 arch_free_page(page, order); 712 kernel_map_pages(page, 1 << order, 0); 713 714 return true; 715 } 716 717 static void __free_pages_ok(struct page *page, unsigned int order) 718 { 719 unsigned long flags; 720 int migratetype; 721 722 if (!free_pages_prepare(page, order)) 723 return; 724 725 local_irq_save(flags); 726 __count_vm_events(PGFREE, 1 << order); 727 migratetype = get_pageblock_migratetype(page); 728 set_freepage_migratetype(page, migratetype); 729 free_one_page(page_zone(page), page, order, migratetype); 730 local_irq_restore(flags); 731 } 732 733 /* 734 * Read access to zone->managed_pages is safe because it's unsigned long, 735 * but we still need to serialize writers. Currently all callers of 736 * __free_pages_bootmem() except put_page_bootmem() should only be used 737 * at boot time. So for shorter boot time, we shift the burden to 738 * put_page_bootmem() to serialize writers. 739 */ 740 void __meminit __free_pages_bootmem(struct page *page, unsigned int order) 741 { 742 unsigned int nr_pages = 1 << order; 743 unsigned int loop; 744 745 prefetchw(page); 746 for (loop = 0; loop < nr_pages; loop++) { 747 struct page *p = &page[loop]; 748 749 if (loop + 1 < nr_pages) 750 prefetchw(p + 1); 751 __ClearPageReserved(p); 752 set_page_count(p, 0); 753 } 754 755 page_zone(page)->managed_pages += 1 << order; 756 set_page_refcounted(page); 757 __free_pages(page, order); 758 } 759 760 #ifdef CONFIG_CMA 761 /* Free whole pageblock and set it's migration type to MIGRATE_CMA. */ 762 void __init init_cma_reserved_pageblock(struct page *page) 763 { 764 unsigned i = pageblock_nr_pages; 765 struct page *p = page; 766 767 do { 768 __ClearPageReserved(p); 769 set_page_count(p, 0); 770 } while (++p, --i); 771 772 set_page_refcounted(page); 773 set_pageblock_migratetype(page, MIGRATE_CMA); 774 __free_pages(page, pageblock_order); 775 totalram_pages += pageblock_nr_pages; 776 #ifdef CONFIG_HIGHMEM 777 if (PageHighMem(page)) 778 totalhigh_pages += pageblock_nr_pages; 779 #endif 780 } 781 #endif 782 783 /* 784 * The order of subdivision here is critical for the IO subsystem. 785 * Please do not alter this order without good reasons and regression 786 * testing. Specifically, as large blocks of memory are subdivided, 787 * the order in which smaller blocks are delivered depends on the order 788 * they're subdivided in this function. This is the primary factor 789 * influencing the order in which pages are delivered to the IO 790 * subsystem according to empirical testing, and this is also justified 791 * by considering the behavior of a buddy system containing a single 792 * large block of memory acted on by a series of small allocations. 793 * This behavior is a critical factor in sglist merging's success. 794 * 795 * -- nyc 796 */ 797 static inline void expand(struct zone *zone, struct page *page, 798 int low, int high, struct free_area *area, 799 int migratetype) 800 { 801 unsigned long size = 1 << high; 802 803 while (high > low) { 804 area--; 805 high--; 806 size >>= 1; 807 VM_BUG_ON(bad_range(zone, &page[size])); 808 809 #ifdef CONFIG_DEBUG_PAGEALLOC 810 if (high < debug_guardpage_minorder()) { 811 /* 812 * Mark as guard pages (or page), that will allow to 813 * merge back to allocator when buddy will be freed. 814 * Corresponding page table entries will not be touched, 815 * pages will stay not present in virtual address space 816 */ 817 INIT_LIST_HEAD(&page[size].lru); 818 set_page_guard_flag(&page[size]); 819 set_page_private(&page[size], high); 820 /* Guard pages are not available for any usage */ 821 __mod_zone_freepage_state(zone, -(1 << high), 822 migratetype); 823 continue; 824 } 825 #endif 826 list_add(&page[size].lru, &area->free_list[migratetype]); 827 area->nr_free++; 828 set_page_order(&page[size], high); 829 } 830 } 831 832 /* 833 * This page is about to be returned from the page allocator 834 */ 835 static inline int check_new_page(struct page *page) 836 { 837 if (unlikely(page_mapcount(page) | 838 (page->mapping != NULL) | 839 (atomic_read(&page->_count) != 0) | 840 (page->flags & PAGE_FLAGS_CHECK_AT_PREP) | 841 (mem_cgroup_bad_page_check(page)))) { 842 bad_page(page); 843 return 1; 844 } 845 return 0; 846 } 847 848 static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) 849 { 850 int i; 851 852 for (i = 0; i < (1 << order); i++) { 853 struct page *p = page + i; 854 if (unlikely(check_new_page(p))) 855 return 1; 856 } 857 858 set_page_private(page, 0); 859 set_page_refcounted(page); 860 861 arch_alloc_page(page, order); 862 kernel_map_pages(page, 1 << order, 1); 863 864 if (gfp_flags & __GFP_ZERO) 865 prep_zero_page(page, order, gfp_flags); 866 867 if (order && (gfp_flags & __GFP_COMP)) 868 prep_compound_page(page, order); 869 870 return 0; 871 } 872 873 /* 874 * Go through the free lists for the given migratetype and remove 875 * the smallest available page from the freelists 876 */ 877 static inline 878 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, 879 int migratetype) 880 { 881 unsigned int current_order; 882 struct free_area * area; 883 struct page *page; 884 885 /* Find a page of the appropriate size in the preferred list */ 886 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 887 area = &(zone->free_area[current_order]); 888 if (list_empty(&area->free_list[migratetype])) 889 continue; 890 891 page = list_entry(area->free_list[migratetype].next, 892 struct page, lru); 893 list_del(&page->lru); 894 rmv_page_order(page); 895 area->nr_free--; 896 expand(zone, page, order, current_order, area, migratetype); 897 return page; 898 } 899 900 return NULL; 901 } 902 903 904 /* 905 * This array describes the order lists are fallen back to when 906 * the free lists for the desirable migrate type are depleted 907 */ 908 static int fallbacks[MIGRATE_TYPES][4] = { 909 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 910 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 911 #ifdef CONFIG_CMA 912 [MIGRATE_MOVABLE] = { MIGRATE_CMA, MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, 913 [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */ 914 #else 915 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, 916 #endif 917 [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */ 918 [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */ 919 }; 920 921 /* 922 * Move the free pages in a range to the free lists of the requested type. 923 * Note that start_page and end_pages are not aligned on a pageblock 924 * boundary. If alignment is required, use move_freepages_block() 925 */ 926 int move_freepages(struct zone *zone, 927 struct page *start_page, struct page *end_page, 928 int migratetype) 929 { 930 struct page *page; 931 unsigned long order; 932 int pages_moved = 0; 933 934 #ifndef CONFIG_HOLES_IN_ZONE 935 /* 936 * page_zone is not safe to call in this context when 937 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant 938 * anyway as we check zone boundaries in move_freepages_block(). 939 * Remove at a later date when no bug reports exist related to 940 * grouping pages by mobility 941 */ 942 BUG_ON(page_zone(start_page) != page_zone(end_page)); 943 #endif 944 945 for (page = start_page; page <= end_page;) { 946 /* Make sure we are not inadvertently changing nodes */ 947 VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone)); 948 949 if (!pfn_valid_within(page_to_pfn(page))) { 950 page++; 951 continue; 952 } 953 954 if (!PageBuddy(page)) { 955 page++; 956 continue; 957 } 958 959 order = page_order(page); 960 list_move(&page->lru, 961 &zone->free_area[order].free_list[migratetype]); 962 set_freepage_migratetype(page, migratetype); 963 page += 1 << order; 964 pages_moved += 1 << order; 965 } 966 967 return pages_moved; 968 } 969 970 int move_freepages_block(struct zone *zone, struct page *page, 971 int migratetype) 972 { 973 unsigned long start_pfn, end_pfn; 974 struct page *start_page, *end_page; 975 976 start_pfn = page_to_pfn(page); 977 start_pfn = start_pfn & ~(pageblock_nr_pages-1); 978 start_page = pfn_to_page(start_pfn); 979 end_page = start_page + pageblock_nr_pages - 1; 980 end_pfn = start_pfn + pageblock_nr_pages - 1; 981 982 /* Do not cross zone boundaries */ 983 if (start_pfn < zone->zone_start_pfn) 984 start_page = page; 985 if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages) 986 return 0; 987 988 return move_freepages(zone, start_page, end_page, migratetype); 989 } 990 991 static void change_pageblock_range(struct page *pageblock_page, 992 int start_order, int migratetype) 993 { 994 int nr_pageblocks = 1 << (start_order - pageblock_order); 995 996 while (nr_pageblocks--) { 997 set_pageblock_migratetype(pageblock_page, migratetype); 998 pageblock_page += pageblock_nr_pages; 999 } 1000 } 1001 1002 /* Remove an element from the buddy allocator from the fallback list */ 1003 static inline struct page * 1004 __rmqueue_fallback(struct zone *zone, int order, int start_migratetype) 1005 { 1006 struct free_area * area; 1007 int current_order; 1008 struct page *page; 1009 int migratetype, i; 1010 1011 /* Find the largest possible block of pages in the other list */ 1012 for (current_order = MAX_ORDER-1; current_order >= order; 1013 --current_order) { 1014 for (i = 0;; i++) { 1015 migratetype = fallbacks[start_migratetype][i]; 1016 1017 /* MIGRATE_RESERVE handled later if necessary */ 1018 if (migratetype == MIGRATE_RESERVE) 1019 break; 1020 1021 area = &(zone->free_area[current_order]); 1022 if (list_empty(&area->free_list[migratetype])) 1023 continue; 1024 1025 page = list_entry(area->free_list[migratetype].next, 1026 struct page, lru); 1027 area->nr_free--; 1028 1029 /* 1030 * If breaking a large block of pages, move all free 1031 * pages to the preferred allocation list. If falling 1032 * back for a reclaimable kernel allocation, be more 1033 * aggressive about taking ownership of free pages 1034 * 1035 * On the other hand, never change migration 1036 * type of MIGRATE_CMA pageblocks nor move CMA 1037 * pages on different free lists. We don't 1038 * want unmovable pages to be allocated from 1039 * MIGRATE_CMA areas. 1040 */ 1041 if (!is_migrate_cma(migratetype) && 1042 (unlikely(current_order >= pageblock_order / 2) || 1043 start_migratetype == MIGRATE_RECLAIMABLE || 1044 page_group_by_mobility_disabled)) { 1045 int pages; 1046 pages = move_freepages_block(zone, page, 1047 start_migratetype); 1048 1049 /* Claim the whole block if over half of it is free */ 1050 if (pages >= (1 << (pageblock_order-1)) || 1051 page_group_by_mobility_disabled) 1052 set_pageblock_migratetype(page, 1053 start_migratetype); 1054 1055 migratetype = start_migratetype; 1056 } 1057 1058 /* Remove the page from the freelists */ 1059 list_del(&page->lru); 1060 rmv_page_order(page); 1061 1062 /* Take ownership for orders >= pageblock_order */ 1063 if (current_order >= pageblock_order && 1064 !is_migrate_cma(migratetype)) 1065 change_pageblock_range(page, current_order, 1066 start_migratetype); 1067 1068 expand(zone, page, order, current_order, area, 1069 is_migrate_cma(migratetype) 1070 ? migratetype : start_migratetype); 1071 1072 trace_mm_page_alloc_extfrag(page, order, current_order, 1073 start_migratetype, migratetype); 1074 1075 return page; 1076 } 1077 } 1078 1079 return NULL; 1080 } 1081 1082 /* 1083 * Do the hard work of removing an element from the buddy allocator. 1084 * Call me with the zone->lock already held. 1085 */ 1086 static struct page *__rmqueue(struct zone *zone, unsigned int order, 1087 int migratetype) 1088 { 1089 struct page *page; 1090 1091 retry_reserve: 1092 page = __rmqueue_smallest(zone, order, migratetype); 1093 1094 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) { 1095 page = __rmqueue_fallback(zone, order, migratetype); 1096 1097 /* 1098 * Use MIGRATE_RESERVE rather than fail an allocation. goto 1099 * is used because __rmqueue_smallest is an inline function 1100 * and we want just one call site 1101 */ 1102 if (!page) { 1103 migratetype = MIGRATE_RESERVE; 1104 goto retry_reserve; 1105 } 1106 } 1107 1108 trace_mm_page_alloc_zone_locked(page, order, migratetype); 1109 return page; 1110 } 1111 1112 /* 1113 * Obtain a specified number of elements from the buddy allocator, all under 1114 * a single hold of the lock, for efficiency. Add them to the supplied list. 1115 * Returns the number of new pages which were placed at *list. 1116 */ 1117 static int rmqueue_bulk(struct zone *zone, unsigned int order, 1118 unsigned long count, struct list_head *list, 1119 int migratetype, int cold) 1120 { 1121 int mt = migratetype, i; 1122 1123 spin_lock(&zone->lock); 1124 for (i = 0; i < count; ++i) { 1125 struct page *page = __rmqueue(zone, order, migratetype); 1126 if (unlikely(page == NULL)) 1127 break; 1128 1129 /* 1130 * Split buddy pages returned by expand() are received here 1131 * in physical page order. The page is added to the callers and 1132 * list and the list head then moves forward. From the callers 1133 * perspective, the linked list is ordered by page number in 1134 * some conditions. This is useful for IO devices that can 1135 * merge IO requests if the physical pages are ordered 1136 * properly. 1137 */ 1138 if (likely(cold == 0)) 1139 list_add(&page->lru, list); 1140 else 1141 list_add_tail(&page->lru, list); 1142 if (IS_ENABLED(CONFIG_CMA)) { 1143 mt = get_pageblock_migratetype(page); 1144 if (!is_migrate_cma(mt) && mt != MIGRATE_ISOLATE) 1145 mt = migratetype; 1146 } 1147 set_freepage_migratetype(page, mt); 1148 list = &page->lru; 1149 if (is_migrate_cma(mt)) 1150 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1151 -(1 << order)); 1152 } 1153 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); 1154 spin_unlock(&zone->lock); 1155 return i; 1156 } 1157 1158 #ifdef CONFIG_NUMA 1159 /* 1160 * Called from the vmstat counter updater to drain pagesets of this 1161 * currently executing processor on remote nodes after they have 1162 * expired. 1163 * 1164 * Note that this function must be called with the thread pinned to 1165 * a single processor. 1166 */ 1167 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) 1168 { 1169 unsigned long flags; 1170 int to_drain; 1171 1172 local_irq_save(flags); 1173 if (pcp->count >= pcp->batch) 1174 to_drain = pcp->batch; 1175 else 1176 to_drain = pcp->count; 1177 if (to_drain > 0) { 1178 free_pcppages_bulk(zone, to_drain, pcp); 1179 pcp->count -= to_drain; 1180 } 1181 local_irq_restore(flags); 1182 } 1183 #endif 1184 1185 /* 1186 * Drain pages of the indicated processor. 1187 * 1188 * The processor must either be the current processor and the 1189 * thread pinned to the current processor or a processor that 1190 * is not online. 1191 */ 1192 static void drain_pages(unsigned int cpu) 1193 { 1194 unsigned long flags; 1195 struct zone *zone; 1196 1197 for_each_populated_zone(zone) { 1198 struct per_cpu_pageset *pset; 1199 struct per_cpu_pages *pcp; 1200 1201 local_irq_save(flags); 1202 pset = per_cpu_ptr(zone->pageset, cpu); 1203 1204 pcp = &pset->pcp; 1205 if (pcp->count) { 1206 free_pcppages_bulk(zone, pcp->count, pcp); 1207 pcp->count = 0; 1208 } 1209 local_irq_restore(flags); 1210 } 1211 } 1212 1213 /* 1214 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 1215 */ 1216 void drain_local_pages(void *arg) 1217 { 1218 drain_pages(smp_processor_id()); 1219 } 1220 1221 /* 1222 * Spill all the per-cpu pages from all CPUs back into the buddy allocator. 1223 * 1224 * Note that this code is protected against sending an IPI to an offline 1225 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs: 1226 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but 1227 * nothing keeps CPUs from showing up after we populated the cpumask and 1228 * before the call to on_each_cpu_mask(). 1229 */ 1230 void drain_all_pages(void) 1231 { 1232 int cpu; 1233 struct per_cpu_pageset *pcp; 1234 struct zone *zone; 1235 1236 /* 1237 * Allocate in the BSS so we wont require allocation in 1238 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y 1239 */ 1240 static cpumask_t cpus_with_pcps; 1241 1242 /* 1243 * We don't care about racing with CPU hotplug event 1244 * as offline notification will cause the notified 1245 * cpu to drain that CPU pcps and on_each_cpu_mask 1246 * disables preemption as part of its processing 1247 */ 1248 for_each_online_cpu(cpu) { 1249 bool has_pcps = false; 1250 for_each_populated_zone(zone) { 1251 pcp = per_cpu_ptr(zone->pageset, cpu); 1252 if (pcp->pcp.count) { 1253 has_pcps = true; 1254 break; 1255 } 1256 } 1257 if (has_pcps) 1258 cpumask_set_cpu(cpu, &cpus_with_pcps); 1259 else 1260 cpumask_clear_cpu(cpu, &cpus_with_pcps); 1261 } 1262 on_each_cpu_mask(&cpus_with_pcps, drain_local_pages, NULL, 1); 1263 } 1264 1265 #ifdef CONFIG_HIBERNATION 1266 1267 void mark_free_pages(struct zone *zone) 1268 { 1269 unsigned long pfn, max_zone_pfn; 1270 unsigned long flags; 1271 int order, t; 1272 struct list_head *curr; 1273 1274 if (!zone->spanned_pages) 1275 return; 1276 1277 spin_lock_irqsave(&zone->lock, flags); 1278 1279 max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; 1280 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 1281 if (pfn_valid(pfn)) { 1282 struct page *page = pfn_to_page(pfn); 1283 1284 if (!swsusp_page_is_forbidden(page)) 1285 swsusp_unset_page_free(page); 1286 } 1287 1288 for_each_migratetype_order(order, t) { 1289 list_for_each(curr, &zone->free_area[order].free_list[t]) { 1290 unsigned long i; 1291 1292 pfn = page_to_pfn(list_entry(curr, struct page, lru)); 1293 for (i = 0; i < (1UL << order); i++) 1294 swsusp_set_page_free(pfn_to_page(pfn + i)); 1295 } 1296 } 1297 spin_unlock_irqrestore(&zone->lock, flags); 1298 } 1299 #endif /* CONFIG_PM */ 1300 1301 /* 1302 * Free a 0-order page 1303 * cold == 1 ? free a cold page : free a hot page 1304 */ 1305 void free_hot_cold_page(struct page *page, int cold) 1306 { 1307 struct zone *zone = page_zone(page); 1308 struct per_cpu_pages *pcp; 1309 unsigned long flags; 1310 int migratetype; 1311 1312 if (!free_pages_prepare(page, 0)) 1313 return; 1314 1315 migratetype = get_pageblock_migratetype(page); 1316 set_freepage_migratetype(page, migratetype); 1317 local_irq_save(flags); 1318 __count_vm_event(PGFREE); 1319 1320 /* 1321 * We only track unmovable, reclaimable and movable on pcp lists. 1322 * Free ISOLATE pages back to the allocator because they are being 1323 * offlined but treat RESERVE as movable pages so we can get those 1324 * areas back if necessary. Otherwise, we may have to free 1325 * excessively into the page allocator 1326 */ 1327 if (migratetype >= MIGRATE_PCPTYPES) { 1328 if (unlikely(migratetype == MIGRATE_ISOLATE)) { 1329 free_one_page(zone, page, 0, migratetype); 1330 goto out; 1331 } 1332 migratetype = MIGRATE_MOVABLE; 1333 } 1334 1335 pcp = &this_cpu_ptr(zone->pageset)->pcp; 1336 if (cold) 1337 list_add_tail(&page->lru, &pcp->lists[migratetype]); 1338 else 1339 list_add(&page->lru, &pcp->lists[migratetype]); 1340 pcp->count++; 1341 if (pcp->count >= pcp->high) { 1342 free_pcppages_bulk(zone, pcp->batch, pcp); 1343 pcp->count -= pcp->batch; 1344 } 1345 1346 out: 1347 local_irq_restore(flags); 1348 } 1349 1350 /* 1351 * Free a list of 0-order pages 1352 */ 1353 void free_hot_cold_page_list(struct list_head *list, int cold) 1354 { 1355 struct page *page, *next; 1356 1357 list_for_each_entry_safe(page, next, list, lru) { 1358 trace_mm_page_free_batched(page, cold); 1359 free_hot_cold_page(page, cold); 1360 } 1361 } 1362 1363 /* 1364 * split_page takes a non-compound higher-order page, and splits it into 1365 * n (1<<order) sub-pages: page[0..n] 1366 * Each sub-page must be freed individually. 1367 * 1368 * Note: this is probably too low level an operation for use in drivers. 1369 * Please consult with lkml before using this in your driver. 1370 */ 1371 void split_page(struct page *page, unsigned int order) 1372 { 1373 int i; 1374 1375 VM_BUG_ON(PageCompound(page)); 1376 VM_BUG_ON(!page_count(page)); 1377 1378 #ifdef CONFIG_KMEMCHECK 1379 /* 1380 * Split shadow pages too, because free(page[0]) would 1381 * otherwise free the whole shadow. 1382 */ 1383 if (kmemcheck_page_is_tracked(page)) 1384 split_page(virt_to_page(page[0].shadow), order); 1385 #endif 1386 1387 for (i = 1; i < (1 << order); i++) 1388 set_page_refcounted(page + i); 1389 } 1390 1391 static int __isolate_free_page(struct page *page, unsigned int order) 1392 { 1393 unsigned long watermark; 1394 struct zone *zone; 1395 int mt; 1396 1397 BUG_ON(!PageBuddy(page)); 1398 1399 zone = page_zone(page); 1400 mt = get_pageblock_migratetype(page); 1401 1402 if (mt != MIGRATE_ISOLATE) { 1403 /* Obey watermarks as if the page was being allocated */ 1404 watermark = low_wmark_pages(zone) + (1 << order); 1405 if (!zone_watermark_ok(zone, 0, watermark, 0, 0)) 1406 return 0; 1407 1408 __mod_zone_freepage_state(zone, -(1UL << order), mt); 1409 } 1410 1411 /* Remove page from free list */ 1412 list_del(&page->lru); 1413 zone->free_area[order].nr_free--; 1414 rmv_page_order(page); 1415 1416 /* Set the pageblock if the isolated page is at least a pageblock */ 1417 if (order >= pageblock_order - 1) { 1418 struct page *endpage = page + (1 << order) - 1; 1419 for (; page < endpage; page += pageblock_nr_pages) { 1420 int mt = get_pageblock_migratetype(page); 1421 if (mt != MIGRATE_ISOLATE && !is_migrate_cma(mt)) 1422 set_pageblock_migratetype(page, 1423 MIGRATE_MOVABLE); 1424 } 1425 } 1426 1427 return 1UL << order; 1428 } 1429 1430 /* 1431 * Similar to split_page except the page is already free. As this is only 1432 * being used for migration, the migratetype of the block also changes. 1433 * As this is called with interrupts disabled, the caller is responsible 1434 * for calling arch_alloc_page() and kernel_map_page() after interrupts 1435 * are enabled. 1436 * 1437 * Note: this is probably too low level an operation for use in drivers. 1438 * Please consult with lkml before using this in your driver. 1439 */ 1440 int split_free_page(struct page *page) 1441 { 1442 unsigned int order; 1443 int nr_pages; 1444 1445 order = page_order(page); 1446 1447 nr_pages = __isolate_free_page(page, order); 1448 if (!nr_pages) 1449 return 0; 1450 1451 /* Split into individual pages */ 1452 set_page_refcounted(page); 1453 split_page(page, order); 1454 return nr_pages; 1455 } 1456 1457 /* 1458 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 1459 * we cheat by calling it from here, in the order > 0 path. Saves a branch 1460 * or two. 1461 */ 1462 static inline 1463 struct page *buffered_rmqueue(struct zone *preferred_zone, 1464 struct zone *zone, int order, gfp_t gfp_flags, 1465 int migratetype) 1466 { 1467 unsigned long flags; 1468 struct page *page; 1469 int cold = !!(gfp_flags & __GFP_COLD); 1470 1471 again: 1472 if (likely(order == 0)) { 1473 struct per_cpu_pages *pcp; 1474 struct list_head *list; 1475 1476 local_irq_save(flags); 1477 pcp = &this_cpu_ptr(zone->pageset)->pcp; 1478 list = &pcp->lists[migratetype]; 1479 if (list_empty(list)) { 1480 pcp->count += rmqueue_bulk(zone, 0, 1481 pcp->batch, list, 1482 migratetype, cold); 1483 if (unlikely(list_empty(list))) 1484 goto failed; 1485 } 1486 1487 if (cold) 1488 page = list_entry(list->prev, struct page, lru); 1489 else 1490 page = list_entry(list->next, struct page, lru); 1491 1492 list_del(&page->lru); 1493 pcp->count--; 1494 } else { 1495 if (unlikely(gfp_flags & __GFP_NOFAIL)) { 1496 /* 1497 * __GFP_NOFAIL is not to be used in new code. 1498 * 1499 * All __GFP_NOFAIL callers should be fixed so that they 1500 * properly detect and handle allocation failures. 1501 * 1502 * We most definitely don't want callers attempting to 1503 * allocate greater than order-1 page units with 1504 * __GFP_NOFAIL. 1505 */ 1506 WARN_ON_ONCE(order > 1); 1507 } 1508 spin_lock_irqsave(&zone->lock, flags); 1509 page = __rmqueue(zone, order, migratetype); 1510 spin_unlock(&zone->lock); 1511 if (!page) 1512 goto failed; 1513 __mod_zone_freepage_state(zone, -(1 << order), 1514 get_pageblock_migratetype(page)); 1515 } 1516 1517 __count_zone_vm_events(PGALLOC, zone, 1 << order); 1518 zone_statistics(preferred_zone, zone, gfp_flags); 1519 local_irq_restore(flags); 1520 1521 VM_BUG_ON(bad_range(zone, page)); 1522 if (prep_new_page(page, order, gfp_flags)) 1523 goto again; 1524 return page; 1525 1526 failed: 1527 local_irq_restore(flags); 1528 return NULL; 1529 } 1530 1531 #ifdef CONFIG_FAIL_PAGE_ALLOC 1532 1533 static struct { 1534 struct fault_attr attr; 1535 1536 u32 ignore_gfp_highmem; 1537 u32 ignore_gfp_wait; 1538 u32 min_order; 1539 } fail_page_alloc = { 1540 .attr = FAULT_ATTR_INITIALIZER, 1541 .ignore_gfp_wait = 1, 1542 .ignore_gfp_highmem = 1, 1543 .min_order = 1, 1544 }; 1545 1546 static int __init setup_fail_page_alloc(char *str) 1547 { 1548 return setup_fault_attr(&fail_page_alloc.attr, str); 1549 } 1550 __setup("fail_page_alloc=", setup_fail_page_alloc); 1551 1552 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1553 { 1554 if (order < fail_page_alloc.min_order) 1555 return false; 1556 if (gfp_mask & __GFP_NOFAIL) 1557 return false; 1558 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 1559 return false; 1560 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) 1561 return false; 1562 1563 return should_fail(&fail_page_alloc.attr, 1 << order); 1564 } 1565 1566 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1567 1568 static int __init fail_page_alloc_debugfs(void) 1569 { 1570 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR; 1571 struct dentry *dir; 1572 1573 dir = fault_create_debugfs_attr("fail_page_alloc", NULL, 1574 &fail_page_alloc.attr); 1575 if (IS_ERR(dir)) 1576 return PTR_ERR(dir); 1577 1578 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir, 1579 &fail_page_alloc.ignore_gfp_wait)) 1580 goto fail; 1581 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir, 1582 &fail_page_alloc.ignore_gfp_highmem)) 1583 goto fail; 1584 if (!debugfs_create_u32("min-order", mode, dir, 1585 &fail_page_alloc.min_order)) 1586 goto fail; 1587 1588 return 0; 1589 fail: 1590 debugfs_remove_recursive(dir); 1591 1592 return -ENOMEM; 1593 } 1594 1595 late_initcall(fail_page_alloc_debugfs); 1596 1597 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1598 1599 #else /* CONFIG_FAIL_PAGE_ALLOC */ 1600 1601 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1602 { 1603 return false; 1604 } 1605 1606 #endif /* CONFIG_FAIL_PAGE_ALLOC */ 1607 1608 /* 1609 * Return true if free pages are above 'mark'. This takes into account the order 1610 * of the allocation. 1611 */ 1612 static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark, 1613 int classzone_idx, int alloc_flags, long free_pages) 1614 { 1615 /* free_pages my go negative - that's OK */ 1616 long min = mark; 1617 long lowmem_reserve = z->lowmem_reserve[classzone_idx]; 1618 int o; 1619 1620 free_pages -= (1 << order) - 1; 1621 if (alloc_flags & ALLOC_HIGH) 1622 min -= min / 2; 1623 if (alloc_flags & ALLOC_HARDER) 1624 min -= min / 4; 1625 #ifdef CONFIG_CMA 1626 /* If allocation can't use CMA areas don't use free CMA pages */ 1627 if (!(alloc_flags & ALLOC_CMA)) 1628 free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES); 1629 #endif 1630 if (free_pages <= min + lowmem_reserve) 1631 return false; 1632 for (o = 0; o < order; o++) { 1633 /* At the next order, this order's pages become unavailable */ 1634 free_pages -= z->free_area[o].nr_free << o; 1635 1636 /* Require fewer higher order pages to be free */ 1637 min >>= 1; 1638 1639 if (free_pages <= min) 1640 return false; 1641 } 1642 return true; 1643 } 1644 1645 bool zone_watermark_ok(struct zone *z, int order, unsigned long mark, 1646 int classzone_idx, int alloc_flags) 1647 { 1648 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, 1649 zone_page_state(z, NR_FREE_PAGES)); 1650 } 1651 1652 bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark, 1653 int classzone_idx, int alloc_flags) 1654 { 1655 long free_pages = zone_page_state(z, NR_FREE_PAGES); 1656 1657 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark) 1658 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES); 1659 1660 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, 1661 free_pages); 1662 } 1663 1664 #ifdef CONFIG_NUMA 1665 /* 1666 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to 1667 * skip over zones that are not allowed by the cpuset, or that have 1668 * been recently (in last second) found to be nearly full. See further 1669 * comments in mmzone.h. Reduces cache footprint of zonelist scans 1670 * that have to skip over a lot of full or unallowed zones. 1671 * 1672 * If the zonelist cache is present in the passed in zonelist, then 1673 * returns a pointer to the allowed node mask (either the current 1674 * tasks mems_allowed, or node_states[N_MEMORY].) 1675 * 1676 * If the zonelist cache is not available for this zonelist, does 1677 * nothing and returns NULL. 1678 * 1679 * If the fullzones BITMAP in the zonelist cache is stale (more than 1680 * a second since last zap'd) then we zap it out (clear its bits.) 1681 * 1682 * We hold off even calling zlc_setup, until after we've checked the 1683 * first zone in the zonelist, on the theory that most allocations will 1684 * be satisfied from that first zone, so best to examine that zone as 1685 * quickly as we can. 1686 */ 1687 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1688 { 1689 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1690 nodemask_t *allowednodes; /* zonelist_cache approximation */ 1691 1692 zlc = zonelist->zlcache_ptr; 1693 if (!zlc) 1694 return NULL; 1695 1696 if (time_after(jiffies, zlc->last_full_zap + HZ)) { 1697 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1698 zlc->last_full_zap = jiffies; 1699 } 1700 1701 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? 1702 &cpuset_current_mems_allowed : 1703 &node_states[N_MEMORY]; 1704 return allowednodes; 1705 } 1706 1707 /* 1708 * Given 'z' scanning a zonelist, run a couple of quick checks to see 1709 * if it is worth looking at further for free memory: 1710 * 1) Check that the zone isn't thought to be full (doesn't have its 1711 * bit set in the zonelist_cache fullzones BITMAP). 1712 * 2) Check that the zones node (obtained from the zonelist_cache 1713 * z_to_n[] mapping) is allowed in the passed in allowednodes mask. 1714 * Return true (non-zero) if zone is worth looking at further, or 1715 * else return false (zero) if it is not. 1716 * 1717 * This check -ignores- the distinction between various watermarks, 1718 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is 1719 * found to be full for any variation of these watermarks, it will 1720 * be considered full for up to one second by all requests, unless 1721 * we are so low on memory on all allowed nodes that we are forced 1722 * into the second scan of the zonelist. 1723 * 1724 * In the second scan we ignore this zonelist cache and exactly 1725 * apply the watermarks to all zones, even it is slower to do so. 1726 * We are low on memory in the second scan, and should leave no stone 1727 * unturned looking for a free page. 1728 */ 1729 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1730 nodemask_t *allowednodes) 1731 { 1732 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1733 int i; /* index of *z in zonelist zones */ 1734 int n; /* node that zone *z is on */ 1735 1736 zlc = zonelist->zlcache_ptr; 1737 if (!zlc) 1738 return 1; 1739 1740 i = z - zonelist->_zonerefs; 1741 n = zlc->z_to_n[i]; 1742 1743 /* This zone is worth trying if it is allowed but not full */ 1744 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); 1745 } 1746 1747 /* 1748 * Given 'z' scanning a zonelist, set the corresponding bit in 1749 * zlc->fullzones, so that subsequent attempts to allocate a page 1750 * from that zone don't waste time re-examining it. 1751 */ 1752 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1753 { 1754 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1755 int i; /* index of *z in zonelist zones */ 1756 1757 zlc = zonelist->zlcache_ptr; 1758 if (!zlc) 1759 return; 1760 1761 i = z - zonelist->_zonerefs; 1762 1763 set_bit(i, zlc->fullzones); 1764 } 1765 1766 /* 1767 * clear all zones full, called after direct reclaim makes progress so that 1768 * a zone that was recently full is not skipped over for up to a second 1769 */ 1770 static void zlc_clear_zones_full(struct zonelist *zonelist) 1771 { 1772 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1773 1774 zlc = zonelist->zlcache_ptr; 1775 if (!zlc) 1776 return; 1777 1778 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1779 } 1780 1781 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) 1782 { 1783 return node_isset(local_zone->node, zone->zone_pgdat->reclaim_nodes); 1784 } 1785 1786 static void __paginginit init_zone_allows_reclaim(int nid) 1787 { 1788 int i; 1789 1790 for_each_online_node(i) 1791 if (node_distance(nid, i) <= RECLAIM_DISTANCE) 1792 node_set(i, NODE_DATA(nid)->reclaim_nodes); 1793 else 1794 zone_reclaim_mode = 1; 1795 } 1796 1797 #else /* CONFIG_NUMA */ 1798 1799 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1800 { 1801 return NULL; 1802 } 1803 1804 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1805 nodemask_t *allowednodes) 1806 { 1807 return 1; 1808 } 1809 1810 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1811 { 1812 } 1813 1814 static void zlc_clear_zones_full(struct zonelist *zonelist) 1815 { 1816 } 1817 1818 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) 1819 { 1820 return true; 1821 } 1822 1823 static inline void init_zone_allows_reclaim(int nid) 1824 { 1825 } 1826 #endif /* CONFIG_NUMA */ 1827 1828 /* 1829 * get_page_from_freelist goes through the zonelist trying to allocate 1830 * a page. 1831 */ 1832 static struct page * 1833 get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order, 1834 struct zonelist *zonelist, int high_zoneidx, int alloc_flags, 1835 struct zone *preferred_zone, int migratetype) 1836 { 1837 struct zoneref *z; 1838 struct page *page = NULL; 1839 int classzone_idx; 1840 struct zone *zone; 1841 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ 1842 int zlc_active = 0; /* set if using zonelist_cache */ 1843 int did_zlc_setup = 0; /* just call zlc_setup() one time */ 1844 1845 classzone_idx = zone_idx(preferred_zone); 1846 zonelist_scan: 1847 /* 1848 * Scan zonelist, looking for a zone with enough free. 1849 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 1850 */ 1851 for_each_zone_zonelist_nodemask(zone, z, zonelist, 1852 high_zoneidx, nodemask) { 1853 if (IS_ENABLED(CONFIG_NUMA) && zlc_active && 1854 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 1855 continue; 1856 if ((alloc_flags & ALLOC_CPUSET) && 1857 !cpuset_zone_allowed_softwall(zone, gfp_mask)) 1858 continue; 1859 /* 1860 * When allocating a page cache page for writing, we 1861 * want to get it from a zone that is within its dirty 1862 * limit, such that no single zone holds more than its 1863 * proportional share of globally allowed dirty pages. 1864 * The dirty limits take into account the zone's 1865 * lowmem reserves and high watermark so that kswapd 1866 * should be able to balance it without having to 1867 * write pages from its LRU list. 1868 * 1869 * This may look like it could increase pressure on 1870 * lower zones by failing allocations in higher zones 1871 * before they are full. But the pages that do spill 1872 * over are limited as the lower zones are protected 1873 * by this very same mechanism. It should not become 1874 * a practical burden to them. 1875 * 1876 * XXX: For now, allow allocations to potentially 1877 * exceed the per-zone dirty limit in the slowpath 1878 * (ALLOC_WMARK_LOW unset) before going into reclaim, 1879 * which is important when on a NUMA setup the allowed 1880 * zones are together not big enough to reach the 1881 * global limit. The proper fix for these situations 1882 * will require awareness of zones in the 1883 * dirty-throttling and the flusher threads. 1884 */ 1885 if ((alloc_flags & ALLOC_WMARK_LOW) && 1886 (gfp_mask & __GFP_WRITE) && !zone_dirty_ok(zone)) 1887 goto this_zone_full; 1888 1889 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK); 1890 if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { 1891 unsigned long mark; 1892 int ret; 1893 1894 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK]; 1895 if (zone_watermark_ok(zone, order, mark, 1896 classzone_idx, alloc_flags)) 1897 goto try_this_zone; 1898 1899 if (IS_ENABLED(CONFIG_NUMA) && 1900 !did_zlc_setup && nr_online_nodes > 1) { 1901 /* 1902 * we do zlc_setup if there are multiple nodes 1903 * and before considering the first zone allowed 1904 * by the cpuset. 1905 */ 1906 allowednodes = zlc_setup(zonelist, alloc_flags); 1907 zlc_active = 1; 1908 did_zlc_setup = 1; 1909 } 1910 1911 if (zone_reclaim_mode == 0 || 1912 !zone_allows_reclaim(preferred_zone, zone)) 1913 goto this_zone_full; 1914 1915 /* 1916 * As we may have just activated ZLC, check if the first 1917 * eligible zone has failed zone_reclaim recently. 1918 */ 1919 if (IS_ENABLED(CONFIG_NUMA) && zlc_active && 1920 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 1921 continue; 1922 1923 ret = zone_reclaim(zone, gfp_mask, order); 1924 switch (ret) { 1925 case ZONE_RECLAIM_NOSCAN: 1926 /* did not scan */ 1927 continue; 1928 case ZONE_RECLAIM_FULL: 1929 /* scanned but unreclaimable */ 1930 continue; 1931 default: 1932 /* did we reclaim enough */ 1933 if (!zone_watermark_ok(zone, order, mark, 1934 classzone_idx, alloc_flags)) 1935 goto this_zone_full; 1936 } 1937 } 1938 1939 try_this_zone: 1940 page = buffered_rmqueue(preferred_zone, zone, order, 1941 gfp_mask, migratetype); 1942 if (page) 1943 break; 1944 this_zone_full: 1945 if (IS_ENABLED(CONFIG_NUMA)) 1946 zlc_mark_zone_full(zonelist, z); 1947 } 1948 1949 if (unlikely(IS_ENABLED(CONFIG_NUMA) && page == NULL && zlc_active)) { 1950 /* Disable zlc cache for second zonelist scan */ 1951 zlc_active = 0; 1952 goto zonelist_scan; 1953 } 1954 1955 if (page) 1956 /* 1957 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was 1958 * necessary to allocate the page. The expectation is 1959 * that the caller is taking steps that will free more 1960 * memory. The caller should avoid the page being used 1961 * for !PFMEMALLOC purposes. 1962 */ 1963 page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS); 1964 1965 return page; 1966 } 1967 1968 /* 1969 * Large machines with many possible nodes should not always dump per-node 1970 * meminfo in irq context. 1971 */ 1972 static inline bool should_suppress_show_mem(void) 1973 { 1974 bool ret = false; 1975 1976 #if NODES_SHIFT > 8 1977 ret = in_interrupt(); 1978 #endif 1979 return ret; 1980 } 1981 1982 static DEFINE_RATELIMIT_STATE(nopage_rs, 1983 DEFAULT_RATELIMIT_INTERVAL, 1984 DEFAULT_RATELIMIT_BURST); 1985 1986 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...) 1987 { 1988 unsigned int filter = SHOW_MEM_FILTER_NODES; 1989 1990 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) || 1991 debug_guardpage_minorder() > 0) 1992 return; 1993 1994 /* 1995 * This documents exceptions given to allocations in certain 1996 * contexts that are allowed to allocate outside current's set 1997 * of allowed nodes. 1998 */ 1999 if (!(gfp_mask & __GFP_NOMEMALLOC)) 2000 if (test_thread_flag(TIF_MEMDIE) || 2001 (current->flags & (PF_MEMALLOC | PF_EXITING))) 2002 filter &= ~SHOW_MEM_FILTER_NODES; 2003 if (in_interrupt() || !(gfp_mask & __GFP_WAIT)) 2004 filter &= ~SHOW_MEM_FILTER_NODES; 2005 2006 if (fmt) { 2007 struct va_format vaf; 2008 va_list args; 2009 2010 va_start(args, fmt); 2011 2012 vaf.fmt = fmt; 2013 vaf.va = &args; 2014 2015 pr_warn("%pV", &vaf); 2016 2017 va_end(args); 2018 } 2019 2020 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n", 2021 current->comm, order, gfp_mask); 2022 2023 dump_stack(); 2024 if (!should_suppress_show_mem()) 2025 show_mem(filter); 2026 } 2027 2028 static inline int 2029 should_alloc_retry(gfp_t gfp_mask, unsigned int order, 2030 unsigned long did_some_progress, 2031 unsigned long pages_reclaimed) 2032 { 2033 /* Do not loop if specifically requested */ 2034 if (gfp_mask & __GFP_NORETRY) 2035 return 0; 2036 2037 /* Always retry if specifically requested */ 2038 if (gfp_mask & __GFP_NOFAIL) 2039 return 1; 2040 2041 /* 2042 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim 2043 * making forward progress without invoking OOM. Suspend also disables 2044 * storage devices so kswapd will not help. Bail if we are suspending. 2045 */ 2046 if (!did_some_progress && pm_suspended_storage()) 2047 return 0; 2048 2049 /* 2050 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER 2051 * means __GFP_NOFAIL, but that may not be true in other 2052 * implementations. 2053 */ 2054 if (order <= PAGE_ALLOC_COSTLY_ORDER) 2055 return 1; 2056 2057 /* 2058 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is 2059 * specified, then we retry until we no longer reclaim any pages 2060 * (above), or we've reclaimed an order of pages at least as 2061 * large as the allocation's order. In both cases, if the 2062 * allocation still fails, we stop retrying. 2063 */ 2064 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order)) 2065 return 1; 2066 2067 return 0; 2068 } 2069 2070 static inline struct page * 2071 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, 2072 struct zonelist *zonelist, enum zone_type high_zoneidx, 2073 nodemask_t *nodemask, struct zone *preferred_zone, 2074 int migratetype) 2075 { 2076 struct page *page; 2077 2078 /* Acquire the OOM killer lock for the zones in zonelist */ 2079 if (!try_set_zonelist_oom(zonelist, gfp_mask)) { 2080 schedule_timeout_uninterruptible(1); 2081 return NULL; 2082 } 2083 2084 /* 2085 * Go through the zonelist yet one more time, keep very high watermark 2086 * here, this is only to catch a parallel oom killing, we must fail if 2087 * we're still under heavy pressure. 2088 */ 2089 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, 2090 order, zonelist, high_zoneidx, 2091 ALLOC_WMARK_HIGH|ALLOC_CPUSET, 2092 preferred_zone, migratetype); 2093 if (page) 2094 goto out; 2095 2096 if (!(gfp_mask & __GFP_NOFAIL)) { 2097 /* The OOM killer will not help higher order allocs */ 2098 if (order > PAGE_ALLOC_COSTLY_ORDER) 2099 goto out; 2100 /* The OOM killer does not needlessly kill tasks for lowmem */ 2101 if (high_zoneidx < ZONE_NORMAL) 2102 goto out; 2103 /* 2104 * GFP_THISNODE contains __GFP_NORETRY and we never hit this. 2105 * Sanity check for bare calls of __GFP_THISNODE, not real OOM. 2106 * The caller should handle page allocation failure by itself if 2107 * it specifies __GFP_THISNODE. 2108 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER. 2109 */ 2110 if (gfp_mask & __GFP_THISNODE) 2111 goto out; 2112 } 2113 /* Exhausted what can be done so it's blamo time */ 2114 out_of_memory(zonelist, gfp_mask, order, nodemask, false); 2115 2116 out: 2117 clear_zonelist_oom(zonelist, gfp_mask); 2118 return page; 2119 } 2120 2121 #ifdef CONFIG_COMPACTION 2122 /* Try memory compaction for high-order allocations before reclaim */ 2123 static struct page * 2124 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, 2125 struct zonelist *zonelist, enum zone_type high_zoneidx, 2126 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, 2127 int migratetype, bool sync_migration, 2128 bool *contended_compaction, bool *deferred_compaction, 2129 unsigned long *did_some_progress) 2130 { 2131 if (!order) 2132 return NULL; 2133 2134 if (compaction_deferred(preferred_zone, order)) { 2135 *deferred_compaction = true; 2136 return NULL; 2137 } 2138 2139 current->flags |= PF_MEMALLOC; 2140 *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask, 2141 nodemask, sync_migration, 2142 contended_compaction); 2143 current->flags &= ~PF_MEMALLOC; 2144 2145 if (*did_some_progress != COMPACT_SKIPPED) { 2146 struct page *page; 2147 2148 /* Page migration frees to the PCP lists but we want merging */ 2149 drain_pages(get_cpu()); 2150 put_cpu(); 2151 2152 page = get_page_from_freelist(gfp_mask, nodemask, 2153 order, zonelist, high_zoneidx, 2154 alloc_flags & ~ALLOC_NO_WATERMARKS, 2155 preferred_zone, migratetype); 2156 if (page) { 2157 preferred_zone->compact_blockskip_flush = false; 2158 preferred_zone->compact_considered = 0; 2159 preferred_zone->compact_defer_shift = 0; 2160 if (order >= preferred_zone->compact_order_failed) 2161 preferred_zone->compact_order_failed = order + 1; 2162 count_vm_event(COMPACTSUCCESS); 2163 return page; 2164 } 2165 2166 /* 2167 * It's bad if compaction run occurs and fails. 2168 * The most likely reason is that pages exist, 2169 * but not enough to satisfy watermarks. 2170 */ 2171 count_vm_event(COMPACTFAIL); 2172 2173 /* 2174 * As async compaction considers a subset of pageblocks, only 2175 * defer if the failure was a sync compaction failure. 2176 */ 2177 if (sync_migration) 2178 defer_compaction(preferred_zone, order); 2179 2180 cond_resched(); 2181 } 2182 2183 return NULL; 2184 } 2185 #else 2186 static inline struct page * 2187 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, 2188 struct zonelist *zonelist, enum zone_type high_zoneidx, 2189 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, 2190 int migratetype, bool sync_migration, 2191 bool *contended_compaction, bool *deferred_compaction, 2192 unsigned long *did_some_progress) 2193 { 2194 return NULL; 2195 } 2196 #endif /* CONFIG_COMPACTION */ 2197 2198 /* Perform direct synchronous page reclaim */ 2199 static int 2200 __perform_reclaim(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist, 2201 nodemask_t *nodemask) 2202 { 2203 struct reclaim_state reclaim_state; 2204 int progress; 2205 2206 cond_resched(); 2207 2208 /* We now go into synchronous reclaim */ 2209 cpuset_memory_pressure_bump(); 2210 current->flags |= PF_MEMALLOC; 2211 lockdep_set_current_reclaim_state(gfp_mask); 2212 reclaim_state.reclaimed_slab = 0; 2213 current->reclaim_state = &reclaim_state; 2214 2215 progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask); 2216 2217 current->reclaim_state = NULL; 2218 lockdep_clear_current_reclaim_state(); 2219 current->flags &= ~PF_MEMALLOC; 2220 2221 cond_resched(); 2222 2223 return progress; 2224 } 2225 2226 /* The really slow allocator path where we enter direct reclaim */ 2227 static inline struct page * 2228 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order, 2229 struct zonelist *zonelist, enum zone_type high_zoneidx, 2230 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, 2231 int migratetype, unsigned long *did_some_progress) 2232 { 2233 struct page *page = NULL; 2234 bool drained = false; 2235 2236 *did_some_progress = __perform_reclaim(gfp_mask, order, zonelist, 2237 nodemask); 2238 if (unlikely(!(*did_some_progress))) 2239 return NULL; 2240 2241 /* After successful reclaim, reconsider all zones for allocation */ 2242 if (IS_ENABLED(CONFIG_NUMA)) 2243 zlc_clear_zones_full(zonelist); 2244 2245 retry: 2246 page = get_page_from_freelist(gfp_mask, nodemask, order, 2247 zonelist, high_zoneidx, 2248 alloc_flags & ~ALLOC_NO_WATERMARKS, 2249 preferred_zone, migratetype); 2250 2251 /* 2252 * If an allocation failed after direct reclaim, it could be because 2253 * pages are pinned on the per-cpu lists. Drain them and try again 2254 */ 2255 if (!page && !drained) { 2256 drain_all_pages(); 2257 drained = true; 2258 goto retry; 2259 } 2260 2261 return page; 2262 } 2263 2264 /* 2265 * This is called in the allocator slow-path if the allocation request is of 2266 * sufficient urgency to ignore watermarks and take other desperate measures 2267 */ 2268 static inline struct page * 2269 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order, 2270 struct zonelist *zonelist, enum zone_type high_zoneidx, 2271 nodemask_t *nodemask, struct zone *preferred_zone, 2272 int migratetype) 2273 { 2274 struct page *page; 2275 2276 do { 2277 page = get_page_from_freelist(gfp_mask, nodemask, order, 2278 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS, 2279 preferred_zone, migratetype); 2280 2281 if (!page && gfp_mask & __GFP_NOFAIL) 2282 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50); 2283 } while (!page && (gfp_mask & __GFP_NOFAIL)); 2284 2285 return page; 2286 } 2287 2288 static inline 2289 void wake_all_kswapd(unsigned int order, struct zonelist *zonelist, 2290 enum zone_type high_zoneidx, 2291 enum zone_type classzone_idx) 2292 { 2293 struct zoneref *z; 2294 struct zone *zone; 2295 2296 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) 2297 wakeup_kswapd(zone, order, classzone_idx); 2298 } 2299 2300 static inline int 2301 gfp_to_alloc_flags(gfp_t gfp_mask) 2302 { 2303 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; 2304 const gfp_t wait = gfp_mask & __GFP_WAIT; 2305 2306 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */ 2307 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH); 2308 2309 /* 2310 * The caller may dip into page reserves a bit more if the caller 2311 * cannot run direct reclaim, or if the caller has realtime scheduling 2312 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will 2313 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). 2314 */ 2315 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH); 2316 2317 if (!wait) { 2318 /* 2319 * Not worth trying to allocate harder for 2320 * __GFP_NOMEMALLOC even if it can't schedule. 2321 */ 2322 if (!(gfp_mask & __GFP_NOMEMALLOC)) 2323 alloc_flags |= ALLOC_HARDER; 2324 /* 2325 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. 2326 * See also cpuset_zone_allowed() comment in kernel/cpuset.c. 2327 */ 2328 alloc_flags &= ~ALLOC_CPUSET; 2329 } else if (unlikely(rt_task(current)) && !in_interrupt()) 2330 alloc_flags |= ALLOC_HARDER; 2331 2332 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) { 2333 if (gfp_mask & __GFP_MEMALLOC) 2334 alloc_flags |= ALLOC_NO_WATERMARKS; 2335 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC)) 2336 alloc_flags |= ALLOC_NO_WATERMARKS; 2337 else if (!in_interrupt() && 2338 ((current->flags & PF_MEMALLOC) || 2339 unlikely(test_thread_flag(TIF_MEMDIE)))) 2340 alloc_flags |= ALLOC_NO_WATERMARKS; 2341 } 2342 #ifdef CONFIG_CMA 2343 if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE) 2344 alloc_flags |= ALLOC_CMA; 2345 #endif 2346 return alloc_flags; 2347 } 2348 2349 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask) 2350 { 2351 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS); 2352 } 2353 2354 static inline struct page * 2355 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, 2356 struct zonelist *zonelist, enum zone_type high_zoneidx, 2357 nodemask_t *nodemask, struct zone *preferred_zone, 2358 int migratetype) 2359 { 2360 const gfp_t wait = gfp_mask & __GFP_WAIT; 2361 struct page *page = NULL; 2362 int alloc_flags; 2363 unsigned long pages_reclaimed = 0; 2364 unsigned long did_some_progress; 2365 bool sync_migration = false; 2366 bool deferred_compaction = false; 2367 bool contended_compaction = false; 2368 2369 /* 2370 * In the slowpath, we sanity check order to avoid ever trying to 2371 * reclaim >= MAX_ORDER areas which will never succeed. Callers may 2372 * be using allocators in order of preference for an area that is 2373 * too large. 2374 */ 2375 if (order >= MAX_ORDER) { 2376 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN)); 2377 return NULL; 2378 } 2379 2380 /* 2381 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and 2382 * __GFP_NOWARN set) should not cause reclaim since the subsystem 2383 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim 2384 * using a larger set of nodes after it has established that the 2385 * allowed per node queues are empty and that nodes are 2386 * over allocated. 2387 */ 2388 if (IS_ENABLED(CONFIG_NUMA) && 2389 (gfp_mask & GFP_THISNODE) == GFP_THISNODE) 2390 goto nopage; 2391 2392 restart: 2393 if (!(gfp_mask & __GFP_NO_KSWAPD)) 2394 wake_all_kswapd(order, zonelist, high_zoneidx, 2395 zone_idx(preferred_zone)); 2396 2397 /* 2398 * OK, we're below the kswapd watermark and have kicked background 2399 * reclaim. Now things get more complex, so set up alloc_flags according 2400 * to how we want to proceed. 2401 */ 2402 alloc_flags = gfp_to_alloc_flags(gfp_mask); 2403 2404 /* 2405 * Find the true preferred zone if the allocation is unconstrained by 2406 * cpusets. 2407 */ 2408 if (!(alloc_flags & ALLOC_CPUSET) && !nodemask) 2409 first_zones_zonelist(zonelist, high_zoneidx, NULL, 2410 &preferred_zone); 2411 2412 rebalance: 2413 /* This is the last chance, in general, before the goto nopage. */ 2414 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, 2415 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS, 2416 preferred_zone, migratetype); 2417 if (page) 2418 goto got_pg; 2419 2420 /* Allocate without watermarks if the context allows */ 2421 if (alloc_flags & ALLOC_NO_WATERMARKS) { 2422 /* 2423 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds 2424 * the allocation is high priority and these type of 2425 * allocations are system rather than user orientated 2426 */ 2427 zonelist = node_zonelist(numa_node_id(), gfp_mask); 2428 2429 page = __alloc_pages_high_priority(gfp_mask, order, 2430 zonelist, high_zoneidx, nodemask, 2431 preferred_zone, migratetype); 2432 if (page) { 2433 goto got_pg; 2434 } 2435 } 2436 2437 /* Atomic allocations - we can't balance anything */ 2438 if (!wait) 2439 goto nopage; 2440 2441 /* Avoid recursion of direct reclaim */ 2442 if (current->flags & PF_MEMALLOC) 2443 goto nopage; 2444 2445 /* Avoid allocations with no watermarks from looping endlessly */ 2446 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL)) 2447 goto nopage; 2448 2449 /* 2450 * Try direct compaction. The first pass is asynchronous. Subsequent 2451 * attempts after direct reclaim are synchronous 2452 */ 2453 page = __alloc_pages_direct_compact(gfp_mask, order, 2454 zonelist, high_zoneidx, 2455 nodemask, 2456 alloc_flags, preferred_zone, 2457 migratetype, sync_migration, 2458 &contended_compaction, 2459 &deferred_compaction, 2460 &did_some_progress); 2461 if (page) 2462 goto got_pg; 2463 sync_migration = true; 2464 2465 /* 2466 * If compaction is deferred for high-order allocations, it is because 2467 * sync compaction recently failed. In this is the case and the caller 2468 * requested a movable allocation that does not heavily disrupt the 2469 * system then fail the allocation instead of entering direct reclaim. 2470 */ 2471 if ((deferred_compaction || contended_compaction) && 2472 (gfp_mask & __GFP_NO_KSWAPD)) 2473 goto nopage; 2474 2475 /* Try direct reclaim and then allocating */ 2476 page = __alloc_pages_direct_reclaim(gfp_mask, order, 2477 zonelist, high_zoneidx, 2478 nodemask, 2479 alloc_flags, preferred_zone, 2480 migratetype, &did_some_progress); 2481 if (page) 2482 goto got_pg; 2483 2484 /* 2485 * If we failed to make any progress reclaiming, then we are 2486 * running out of options and have to consider going OOM 2487 */ 2488 if (!did_some_progress) { 2489 if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { 2490 if (oom_killer_disabled) 2491 goto nopage; 2492 /* Coredumps can quickly deplete all memory reserves */ 2493 if ((current->flags & PF_DUMPCORE) && 2494 !(gfp_mask & __GFP_NOFAIL)) 2495 goto nopage; 2496 page = __alloc_pages_may_oom(gfp_mask, order, 2497 zonelist, high_zoneidx, 2498 nodemask, preferred_zone, 2499 migratetype); 2500 if (page) 2501 goto got_pg; 2502 2503 if (!(gfp_mask & __GFP_NOFAIL)) { 2504 /* 2505 * The oom killer is not called for high-order 2506 * allocations that may fail, so if no progress 2507 * is being made, there are no other options and 2508 * retrying is unlikely to help. 2509 */ 2510 if (order > PAGE_ALLOC_COSTLY_ORDER) 2511 goto nopage; 2512 /* 2513 * The oom killer is not called for lowmem 2514 * allocations to prevent needlessly killing 2515 * innocent tasks. 2516 */ 2517 if (high_zoneidx < ZONE_NORMAL) 2518 goto nopage; 2519 } 2520 2521 goto restart; 2522 } 2523 } 2524 2525 /* Check if we should retry the allocation */ 2526 pages_reclaimed += did_some_progress; 2527 if (should_alloc_retry(gfp_mask, order, did_some_progress, 2528 pages_reclaimed)) { 2529 /* Wait for some write requests to complete then retry */ 2530 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50); 2531 goto rebalance; 2532 } else { 2533 /* 2534 * High-order allocations do not necessarily loop after 2535 * direct reclaim and reclaim/compaction depends on compaction 2536 * being called after reclaim so call directly if necessary 2537 */ 2538 page = __alloc_pages_direct_compact(gfp_mask, order, 2539 zonelist, high_zoneidx, 2540 nodemask, 2541 alloc_flags, preferred_zone, 2542 migratetype, sync_migration, 2543 &contended_compaction, 2544 &deferred_compaction, 2545 &did_some_progress); 2546 if (page) 2547 goto got_pg; 2548 } 2549 2550 nopage: 2551 warn_alloc_failed(gfp_mask, order, NULL); 2552 return page; 2553 got_pg: 2554 if (kmemcheck_enabled) 2555 kmemcheck_pagealloc_alloc(page, order, gfp_mask); 2556 2557 return page; 2558 } 2559 2560 /* 2561 * This is the 'heart' of the zoned buddy allocator. 2562 */ 2563 struct page * 2564 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, 2565 struct zonelist *zonelist, nodemask_t *nodemask) 2566 { 2567 enum zone_type high_zoneidx = gfp_zone(gfp_mask); 2568 struct zone *preferred_zone; 2569 struct page *page = NULL; 2570 int migratetype = allocflags_to_migratetype(gfp_mask); 2571 unsigned int cpuset_mems_cookie; 2572 int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET; 2573 struct mem_cgroup *memcg = NULL; 2574 2575 gfp_mask &= gfp_allowed_mask; 2576 2577 lockdep_trace_alloc(gfp_mask); 2578 2579 might_sleep_if(gfp_mask & __GFP_WAIT); 2580 2581 if (should_fail_alloc_page(gfp_mask, order)) 2582 return NULL; 2583 2584 /* 2585 * Check the zones suitable for the gfp_mask contain at least one 2586 * valid zone. It's possible to have an empty zonelist as a result 2587 * of GFP_THISNODE and a memoryless node 2588 */ 2589 if (unlikely(!zonelist->_zonerefs->zone)) 2590 return NULL; 2591 2592 /* 2593 * Will only have any effect when __GFP_KMEMCG is set. This is 2594 * verified in the (always inline) callee 2595 */ 2596 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order)) 2597 return NULL; 2598 2599 retry_cpuset: 2600 cpuset_mems_cookie = get_mems_allowed(); 2601 2602 /* The preferred zone is used for statistics later */ 2603 first_zones_zonelist(zonelist, high_zoneidx, 2604 nodemask ? : &cpuset_current_mems_allowed, 2605 &preferred_zone); 2606 if (!preferred_zone) 2607 goto out; 2608 2609 #ifdef CONFIG_CMA 2610 if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE) 2611 alloc_flags |= ALLOC_CMA; 2612 #endif 2613 /* First allocation attempt */ 2614 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order, 2615 zonelist, high_zoneidx, alloc_flags, 2616 preferred_zone, migratetype); 2617 if (unlikely(!page)) 2618 page = __alloc_pages_slowpath(gfp_mask, order, 2619 zonelist, high_zoneidx, nodemask, 2620 preferred_zone, migratetype); 2621 2622 trace_mm_page_alloc(page, order, gfp_mask, migratetype); 2623 2624 out: 2625 /* 2626 * When updating a task's mems_allowed, it is possible to race with 2627 * parallel threads in such a way that an allocation can fail while 2628 * the mask is being updated. If a page allocation is about to fail, 2629 * check if the cpuset changed during allocation and if so, retry. 2630 */ 2631 if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) 2632 goto retry_cpuset; 2633 2634 memcg_kmem_commit_charge(page, memcg, order); 2635 2636 return page; 2637 } 2638 EXPORT_SYMBOL(__alloc_pages_nodemask); 2639 2640 /* 2641 * Common helper functions. 2642 */ 2643 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 2644 { 2645 struct page *page; 2646 2647 /* 2648 * __get_free_pages() returns a 32-bit address, which cannot represent 2649 * a highmem page 2650 */ 2651 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 2652 2653 page = alloc_pages(gfp_mask, order); 2654 if (!page) 2655 return 0; 2656 return (unsigned long) page_address(page); 2657 } 2658 EXPORT_SYMBOL(__get_free_pages); 2659 2660 unsigned long get_zeroed_page(gfp_t gfp_mask) 2661 { 2662 return __get_free_pages(gfp_mask | __GFP_ZERO, 0); 2663 } 2664 EXPORT_SYMBOL(get_zeroed_page); 2665 2666 void __free_pages(struct page *page, unsigned int order) 2667 { 2668 if (put_page_testzero(page)) { 2669 if (order == 0) 2670 free_hot_cold_page(page, 0); 2671 else 2672 __free_pages_ok(page, order); 2673 } 2674 } 2675 2676 EXPORT_SYMBOL(__free_pages); 2677 2678 void free_pages(unsigned long addr, unsigned int order) 2679 { 2680 if (addr != 0) { 2681 VM_BUG_ON(!virt_addr_valid((void *)addr)); 2682 __free_pages(virt_to_page((void *)addr), order); 2683 } 2684 } 2685 2686 EXPORT_SYMBOL(free_pages); 2687 2688 /* 2689 * __free_memcg_kmem_pages and free_memcg_kmem_pages will free 2690 * pages allocated with __GFP_KMEMCG. 2691 * 2692 * Those pages are accounted to a particular memcg, embedded in the 2693 * corresponding page_cgroup. To avoid adding a hit in the allocator to search 2694 * for that information only to find out that it is NULL for users who have no 2695 * interest in that whatsoever, we provide these functions. 2696 * 2697 * The caller knows better which flags it relies on. 2698 */ 2699 void __free_memcg_kmem_pages(struct page *page, unsigned int order) 2700 { 2701 memcg_kmem_uncharge_pages(page, order); 2702 __free_pages(page, order); 2703 } 2704 2705 void free_memcg_kmem_pages(unsigned long addr, unsigned int order) 2706 { 2707 if (addr != 0) { 2708 VM_BUG_ON(!virt_addr_valid((void *)addr)); 2709 __free_memcg_kmem_pages(virt_to_page((void *)addr), order); 2710 } 2711 } 2712 2713 static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size) 2714 { 2715 if (addr) { 2716 unsigned long alloc_end = addr + (PAGE_SIZE << order); 2717 unsigned long used = addr + PAGE_ALIGN(size); 2718 2719 split_page(virt_to_page((void *)addr), order); 2720 while (used < alloc_end) { 2721 free_page(used); 2722 used += PAGE_SIZE; 2723 } 2724 } 2725 return (void *)addr; 2726 } 2727 2728 /** 2729 * alloc_pages_exact - allocate an exact number physically-contiguous pages. 2730 * @size: the number of bytes to allocate 2731 * @gfp_mask: GFP flags for the allocation 2732 * 2733 * This function is similar to alloc_pages(), except that it allocates the 2734 * minimum number of pages to satisfy the request. alloc_pages() can only 2735 * allocate memory in power-of-two pages. 2736 * 2737 * This function is also limited by MAX_ORDER. 2738 * 2739 * Memory allocated by this function must be released by free_pages_exact(). 2740 */ 2741 void *alloc_pages_exact(size_t size, gfp_t gfp_mask) 2742 { 2743 unsigned int order = get_order(size); 2744 unsigned long addr; 2745 2746 addr = __get_free_pages(gfp_mask, order); 2747 return make_alloc_exact(addr, order, size); 2748 } 2749 EXPORT_SYMBOL(alloc_pages_exact); 2750 2751 /** 2752 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous 2753 * pages on a node. 2754 * @nid: the preferred node ID where memory should be allocated 2755 * @size: the number of bytes to allocate 2756 * @gfp_mask: GFP flags for the allocation 2757 * 2758 * Like alloc_pages_exact(), but try to allocate on node nid first before falling 2759 * back. 2760 * Note this is not alloc_pages_exact_node() which allocates on a specific node, 2761 * but is not exact. 2762 */ 2763 void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask) 2764 { 2765 unsigned order = get_order(size); 2766 struct page *p = alloc_pages_node(nid, gfp_mask, order); 2767 if (!p) 2768 return NULL; 2769 return make_alloc_exact((unsigned long)page_address(p), order, size); 2770 } 2771 EXPORT_SYMBOL(alloc_pages_exact_nid); 2772 2773 /** 2774 * free_pages_exact - release memory allocated via alloc_pages_exact() 2775 * @virt: the value returned by alloc_pages_exact. 2776 * @size: size of allocation, same value as passed to alloc_pages_exact(). 2777 * 2778 * Release the memory allocated by a previous call to alloc_pages_exact. 2779 */ 2780 void free_pages_exact(void *virt, size_t size) 2781 { 2782 unsigned long addr = (unsigned long)virt; 2783 unsigned long end = addr + PAGE_ALIGN(size); 2784 2785 while (addr < end) { 2786 free_page(addr); 2787 addr += PAGE_SIZE; 2788 } 2789 } 2790 EXPORT_SYMBOL(free_pages_exact); 2791 2792 static unsigned int nr_free_zone_pages(int offset) 2793 { 2794 struct zoneref *z; 2795 struct zone *zone; 2796 2797 /* Just pick one node, since fallback list is circular */ 2798 unsigned int sum = 0; 2799 2800 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); 2801 2802 for_each_zone_zonelist(zone, z, zonelist, offset) { 2803 unsigned long size = zone->present_pages; 2804 unsigned long high = high_wmark_pages(zone); 2805 if (size > high) 2806 sum += size - high; 2807 } 2808 2809 return sum; 2810 } 2811 2812 /* 2813 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL 2814 */ 2815 unsigned int nr_free_buffer_pages(void) 2816 { 2817 return nr_free_zone_pages(gfp_zone(GFP_USER)); 2818 } 2819 EXPORT_SYMBOL_GPL(nr_free_buffer_pages); 2820 2821 /* 2822 * Amount of free RAM allocatable within all zones 2823 */ 2824 unsigned int nr_free_pagecache_pages(void) 2825 { 2826 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); 2827 } 2828 2829 static inline void show_node(struct zone *zone) 2830 { 2831 if (IS_ENABLED(CONFIG_NUMA)) 2832 printk("Node %d ", zone_to_nid(zone)); 2833 } 2834 2835 void si_meminfo(struct sysinfo *val) 2836 { 2837 val->totalram = totalram_pages; 2838 val->sharedram = 0; 2839 val->freeram = global_page_state(NR_FREE_PAGES); 2840 val->bufferram = nr_blockdev_pages(); 2841 val->totalhigh = totalhigh_pages; 2842 val->freehigh = nr_free_highpages(); 2843 val->mem_unit = PAGE_SIZE; 2844 } 2845 2846 EXPORT_SYMBOL(si_meminfo); 2847 2848 #ifdef CONFIG_NUMA 2849 void si_meminfo_node(struct sysinfo *val, int nid) 2850 { 2851 pg_data_t *pgdat = NODE_DATA(nid); 2852 2853 val->totalram = pgdat->node_present_pages; 2854 val->freeram = node_page_state(nid, NR_FREE_PAGES); 2855 #ifdef CONFIG_HIGHMEM 2856 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; 2857 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], 2858 NR_FREE_PAGES); 2859 #else 2860 val->totalhigh = 0; 2861 val->freehigh = 0; 2862 #endif 2863 val->mem_unit = PAGE_SIZE; 2864 } 2865 #endif 2866 2867 /* 2868 * Determine whether the node should be displayed or not, depending on whether 2869 * SHOW_MEM_FILTER_NODES was passed to show_free_areas(). 2870 */ 2871 bool skip_free_areas_node(unsigned int flags, int nid) 2872 { 2873 bool ret = false; 2874 unsigned int cpuset_mems_cookie; 2875 2876 if (!(flags & SHOW_MEM_FILTER_NODES)) 2877 goto out; 2878 2879 do { 2880 cpuset_mems_cookie = get_mems_allowed(); 2881 ret = !node_isset(nid, cpuset_current_mems_allowed); 2882 } while (!put_mems_allowed(cpuset_mems_cookie)); 2883 out: 2884 return ret; 2885 } 2886 2887 #define K(x) ((x) << (PAGE_SHIFT-10)) 2888 2889 static void show_migration_types(unsigned char type) 2890 { 2891 static const char types[MIGRATE_TYPES] = { 2892 [MIGRATE_UNMOVABLE] = 'U', 2893 [MIGRATE_RECLAIMABLE] = 'E', 2894 [MIGRATE_MOVABLE] = 'M', 2895 [MIGRATE_RESERVE] = 'R', 2896 #ifdef CONFIG_CMA 2897 [MIGRATE_CMA] = 'C', 2898 #endif 2899 [MIGRATE_ISOLATE] = 'I', 2900 }; 2901 char tmp[MIGRATE_TYPES + 1]; 2902 char *p = tmp; 2903 int i; 2904 2905 for (i = 0; i < MIGRATE_TYPES; i++) { 2906 if (type & (1 << i)) 2907 *p++ = types[i]; 2908 } 2909 2910 *p = '\0'; 2911 printk("(%s) ", tmp); 2912 } 2913 2914 /* 2915 * Show free area list (used inside shift_scroll-lock stuff) 2916 * We also calculate the percentage fragmentation. We do this by counting the 2917 * memory on each free list with the exception of the first item on the list. 2918 * Suppresses nodes that are not allowed by current's cpuset if 2919 * SHOW_MEM_FILTER_NODES is passed. 2920 */ 2921 void show_free_areas(unsigned int filter) 2922 { 2923 int cpu; 2924 struct zone *zone; 2925 2926 for_each_populated_zone(zone) { 2927 if (skip_free_areas_node(filter, zone_to_nid(zone))) 2928 continue; 2929 show_node(zone); 2930 printk("%s per-cpu:\n", zone->name); 2931 2932 for_each_online_cpu(cpu) { 2933 struct per_cpu_pageset *pageset; 2934 2935 pageset = per_cpu_ptr(zone->pageset, cpu); 2936 2937 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n", 2938 cpu, pageset->pcp.high, 2939 pageset->pcp.batch, pageset->pcp.count); 2940 } 2941 } 2942 2943 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n" 2944 " active_file:%lu inactive_file:%lu isolated_file:%lu\n" 2945 " unevictable:%lu" 2946 " dirty:%lu writeback:%lu unstable:%lu\n" 2947 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n" 2948 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n" 2949 " free_cma:%lu\n", 2950 global_page_state(NR_ACTIVE_ANON), 2951 global_page_state(NR_INACTIVE_ANON), 2952 global_page_state(NR_ISOLATED_ANON), 2953 global_page_state(NR_ACTIVE_FILE), 2954 global_page_state(NR_INACTIVE_FILE), 2955 global_page_state(NR_ISOLATED_FILE), 2956 global_page_state(NR_UNEVICTABLE), 2957 global_page_state(NR_FILE_DIRTY), 2958 global_page_state(NR_WRITEBACK), 2959 global_page_state(NR_UNSTABLE_NFS), 2960 global_page_state(NR_FREE_PAGES), 2961 global_page_state(NR_SLAB_RECLAIMABLE), 2962 global_page_state(NR_SLAB_UNRECLAIMABLE), 2963 global_page_state(NR_FILE_MAPPED), 2964 global_page_state(NR_SHMEM), 2965 global_page_state(NR_PAGETABLE), 2966 global_page_state(NR_BOUNCE), 2967 global_page_state(NR_FREE_CMA_PAGES)); 2968 2969 for_each_populated_zone(zone) { 2970 int i; 2971 2972 if (skip_free_areas_node(filter, zone_to_nid(zone))) 2973 continue; 2974 show_node(zone); 2975 printk("%s" 2976 " free:%lukB" 2977 " min:%lukB" 2978 " low:%lukB" 2979 " high:%lukB" 2980 " active_anon:%lukB" 2981 " inactive_anon:%lukB" 2982 " active_file:%lukB" 2983 " inactive_file:%lukB" 2984 " unevictable:%lukB" 2985 " isolated(anon):%lukB" 2986 " isolated(file):%lukB" 2987 " present:%lukB" 2988 " managed:%lukB" 2989 " mlocked:%lukB" 2990 " dirty:%lukB" 2991 " writeback:%lukB" 2992 " mapped:%lukB" 2993 " shmem:%lukB" 2994 " slab_reclaimable:%lukB" 2995 " slab_unreclaimable:%lukB" 2996 " kernel_stack:%lukB" 2997 " pagetables:%lukB" 2998 " unstable:%lukB" 2999 " bounce:%lukB" 3000 " free_cma:%lukB" 3001 " writeback_tmp:%lukB" 3002 " pages_scanned:%lu" 3003 " all_unreclaimable? %s" 3004 "\n", 3005 zone->name, 3006 K(zone_page_state(zone, NR_FREE_PAGES)), 3007 K(min_wmark_pages(zone)), 3008 K(low_wmark_pages(zone)), 3009 K(high_wmark_pages(zone)), 3010 K(zone_page_state(zone, NR_ACTIVE_ANON)), 3011 K(zone_page_state(zone, NR_INACTIVE_ANON)), 3012 K(zone_page_state(zone, NR_ACTIVE_FILE)), 3013 K(zone_page_state(zone, NR_INACTIVE_FILE)), 3014 K(zone_page_state(zone, NR_UNEVICTABLE)), 3015 K(zone_page_state(zone, NR_ISOLATED_ANON)), 3016 K(zone_page_state(zone, NR_ISOLATED_FILE)), 3017 K(zone->present_pages), 3018 K(zone->managed_pages), 3019 K(zone_page_state(zone, NR_MLOCK)), 3020 K(zone_page_state(zone, NR_FILE_DIRTY)), 3021 K(zone_page_state(zone, NR_WRITEBACK)), 3022 K(zone_page_state(zone, NR_FILE_MAPPED)), 3023 K(zone_page_state(zone, NR_SHMEM)), 3024 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)), 3025 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)), 3026 zone_page_state(zone, NR_KERNEL_STACK) * 3027 THREAD_SIZE / 1024, 3028 K(zone_page_state(zone, NR_PAGETABLE)), 3029 K(zone_page_state(zone, NR_UNSTABLE_NFS)), 3030 K(zone_page_state(zone, NR_BOUNCE)), 3031 K(zone_page_state(zone, NR_FREE_CMA_PAGES)), 3032 K(zone_page_state(zone, NR_WRITEBACK_TEMP)), 3033 zone->pages_scanned, 3034 (zone->all_unreclaimable ? "yes" : "no") 3035 ); 3036 printk("lowmem_reserve[]:"); 3037 for (i = 0; i < MAX_NR_ZONES; i++) 3038 printk(" %lu", zone->lowmem_reserve[i]); 3039 printk("\n"); 3040 } 3041 3042 for_each_populated_zone(zone) { 3043 unsigned long nr[MAX_ORDER], flags, order, total = 0; 3044 unsigned char types[MAX_ORDER]; 3045 3046 if (skip_free_areas_node(filter, zone_to_nid(zone))) 3047 continue; 3048 show_node(zone); 3049 printk("%s: ", zone->name); 3050 3051 spin_lock_irqsave(&zone->lock, flags); 3052 for (order = 0; order < MAX_ORDER; order++) { 3053 struct free_area *area = &zone->free_area[order]; 3054 int type; 3055 3056 nr[order] = area->nr_free; 3057 total += nr[order] << order; 3058 3059 types[order] = 0; 3060 for (type = 0; type < MIGRATE_TYPES; type++) { 3061 if (!list_empty(&area->free_list[type])) 3062 types[order] |= 1 << type; 3063 } 3064 } 3065 spin_unlock_irqrestore(&zone->lock, flags); 3066 for (order = 0; order < MAX_ORDER; order++) { 3067 printk("%lu*%lukB ", nr[order], K(1UL) << order); 3068 if (nr[order]) 3069 show_migration_types(types[order]); 3070 } 3071 printk("= %lukB\n", K(total)); 3072 } 3073 3074 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES)); 3075 3076 show_swap_cache_info(); 3077 } 3078 3079 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) 3080 { 3081 zoneref->zone = zone; 3082 zoneref->zone_idx = zone_idx(zone); 3083 } 3084 3085 /* 3086 * Builds allocation fallback zone lists. 3087 * 3088 * Add all populated zones of a node to the zonelist. 3089 */ 3090 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, 3091 int nr_zones, enum zone_type zone_type) 3092 { 3093 struct zone *zone; 3094 3095 BUG_ON(zone_type >= MAX_NR_ZONES); 3096 zone_type++; 3097 3098 do { 3099 zone_type--; 3100 zone = pgdat->node_zones + zone_type; 3101 if (populated_zone(zone)) { 3102 zoneref_set_zone(zone, 3103 &zonelist->_zonerefs[nr_zones++]); 3104 check_highest_zone(zone_type); 3105 } 3106 3107 } while (zone_type); 3108 return nr_zones; 3109 } 3110 3111 3112 /* 3113 * zonelist_order: 3114 * 0 = automatic detection of better ordering. 3115 * 1 = order by ([node] distance, -zonetype) 3116 * 2 = order by (-zonetype, [node] distance) 3117 * 3118 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create 3119 * the same zonelist. So only NUMA can configure this param. 3120 */ 3121 #define ZONELIST_ORDER_DEFAULT 0 3122 #define ZONELIST_ORDER_NODE 1 3123 #define ZONELIST_ORDER_ZONE 2 3124 3125 /* zonelist order in the kernel. 3126 * set_zonelist_order() will set this to NODE or ZONE. 3127 */ 3128 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT; 3129 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"}; 3130 3131 3132 #ifdef CONFIG_NUMA 3133 /* The value user specified ....changed by config */ 3134 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT; 3135 /* string for sysctl */ 3136 #define NUMA_ZONELIST_ORDER_LEN 16 3137 char numa_zonelist_order[16] = "default"; 3138 3139 /* 3140 * interface for configure zonelist ordering. 3141 * command line option "numa_zonelist_order" 3142 * = "[dD]efault - default, automatic configuration. 3143 * = "[nN]ode - order by node locality, then by zone within node 3144 * = "[zZ]one - order by zone, then by locality within zone 3145 */ 3146 3147 static int __parse_numa_zonelist_order(char *s) 3148 { 3149 if (*s == 'd' || *s == 'D') { 3150 user_zonelist_order = ZONELIST_ORDER_DEFAULT; 3151 } else if (*s == 'n' || *s == 'N') { 3152 user_zonelist_order = ZONELIST_ORDER_NODE; 3153 } else if (*s == 'z' || *s == 'Z') { 3154 user_zonelist_order = ZONELIST_ORDER_ZONE; 3155 } else { 3156 printk(KERN_WARNING 3157 "Ignoring invalid numa_zonelist_order value: " 3158 "%s\n", s); 3159 return -EINVAL; 3160 } 3161 return 0; 3162 } 3163 3164 static __init int setup_numa_zonelist_order(char *s) 3165 { 3166 int ret; 3167 3168 if (!s) 3169 return 0; 3170 3171 ret = __parse_numa_zonelist_order(s); 3172 if (ret == 0) 3173 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN); 3174 3175 return ret; 3176 } 3177 early_param("numa_zonelist_order", setup_numa_zonelist_order); 3178 3179 /* 3180 * sysctl handler for numa_zonelist_order 3181 */ 3182 int numa_zonelist_order_handler(ctl_table *table, int write, 3183 void __user *buffer, size_t *length, 3184 loff_t *ppos) 3185 { 3186 char saved_string[NUMA_ZONELIST_ORDER_LEN]; 3187 int ret; 3188 static DEFINE_MUTEX(zl_order_mutex); 3189 3190 mutex_lock(&zl_order_mutex); 3191 if (write) 3192 strcpy(saved_string, (char*)table->data); 3193 ret = proc_dostring(table, write, buffer, length, ppos); 3194 if (ret) 3195 goto out; 3196 if (write) { 3197 int oldval = user_zonelist_order; 3198 if (__parse_numa_zonelist_order((char*)table->data)) { 3199 /* 3200 * bogus value. restore saved string 3201 */ 3202 strncpy((char*)table->data, saved_string, 3203 NUMA_ZONELIST_ORDER_LEN); 3204 user_zonelist_order = oldval; 3205 } else if (oldval != user_zonelist_order) { 3206 mutex_lock(&zonelists_mutex); 3207 build_all_zonelists(NULL, NULL); 3208 mutex_unlock(&zonelists_mutex); 3209 } 3210 } 3211 out: 3212 mutex_unlock(&zl_order_mutex); 3213 return ret; 3214 } 3215 3216 3217 #define MAX_NODE_LOAD (nr_online_nodes) 3218 static int node_load[MAX_NUMNODES]; 3219 3220 /** 3221 * find_next_best_node - find the next node that should appear in a given node's fallback list 3222 * @node: node whose fallback list we're appending 3223 * @used_node_mask: nodemask_t of already used nodes 3224 * 3225 * We use a number of factors to determine which is the next node that should 3226 * appear on a given node's fallback list. The node should not have appeared 3227 * already in @node's fallback list, and it should be the next closest node 3228 * according to the distance array (which contains arbitrary distance values 3229 * from each node to each node in the system), and should also prefer nodes 3230 * with no CPUs, since presumably they'll have very little allocation pressure 3231 * on them otherwise. 3232 * It returns -1 if no node is found. 3233 */ 3234 static int find_next_best_node(int node, nodemask_t *used_node_mask) 3235 { 3236 int n, val; 3237 int min_val = INT_MAX; 3238 int best_node = -1; 3239 const struct cpumask *tmp = cpumask_of_node(0); 3240 3241 /* Use the local node if we haven't already */ 3242 if (!node_isset(node, *used_node_mask)) { 3243 node_set(node, *used_node_mask); 3244 return node; 3245 } 3246 3247 for_each_node_state(n, N_MEMORY) { 3248 3249 /* Don't want a node to appear more than once */ 3250 if (node_isset(n, *used_node_mask)) 3251 continue; 3252 3253 /* Use the distance array to find the distance */ 3254 val = node_distance(node, n); 3255 3256 /* Penalize nodes under us ("prefer the next node") */ 3257 val += (n < node); 3258 3259 /* Give preference to headless and unused nodes */ 3260 tmp = cpumask_of_node(n); 3261 if (!cpumask_empty(tmp)) 3262 val += PENALTY_FOR_NODE_WITH_CPUS; 3263 3264 /* Slight preference for less loaded node */ 3265 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 3266 val += node_load[n]; 3267 3268 if (val < min_val) { 3269 min_val = val; 3270 best_node = n; 3271 } 3272 } 3273 3274 if (best_node >= 0) 3275 node_set(best_node, *used_node_mask); 3276 3277 return best_node; 3278 } 3279 3280 3281 /* 3282 * Build zonelists ordered by node and zones within node. 3283 * This results in maximum locality--normal zone overflows into local 3284 * DMA zone, if any--but risks exhausting DMA zone. 3285 */ 3286 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) 3287 { 3288 int j; 3289 struct zonelist *zonelist; 3290 3291 zonelist = &pgdat->node_zonelists[0]; 3292 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++) 3293 ; 3294 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 3295 MAX_NR_ZONES - 1); 3296 zonelist->_zonerefs[j].zone = NULL; 3297 zonelist->_zonerefs[j].zone_idx = 0; 3298 } 3299 3300 /* 3301 * Build gfp_thisnode zonelists 3302 */ 3303 static void build_thisnode_zonelists(pg_data_t *pgdat) 3304 { 3305 int j; 3306 struct zonelist *zonelist; 3307 3308 zonelist = &pgdat->node_zonelists[1]; 3309 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 3310 zonelist->_zonerefs[j].zone = NULL; 3311 zonelist->_zonerefs[j].zone_idx = 0; 3312 } 3313 3314 /* 3315 * Build zonelists ordered by zone and nodes within zones. 3316 * This results in conserving DMA zone[s] until all Normal memory is 3317 * exhausted, but results in overflowing to remote node while memory 3318 * may still exist in local DMA zone. 3319 */ 3320 static int node_order[MAX_NUMNODES]; 3321 3322 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) 3323 { 3324 int pos, j, node; 3325 int zone_type; /* needs to be signed */ 3326 struct zone *z; 3327 struct zonelist *zonelist; 3328 3329 zonelist = &pgdat->node_zonelists[0]; 3330 pos = 0; 3331 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) { 3332 for (j = 0; j < nr_nodes; j++) { 3333 node = node_order[j]; 3334 z = &NODE_DATA(node)->node_zones[zone_type]; 3335 if (populated_zone(z)) { 3336 zoneref_set_zone(z, 3337 &zonelist->_zonerefs[pos++]); 3338 check_highest_zone(zone_type); 3339 } 3340 } 3341 } 3342 zonelist->_zonerefs[pos].zone = NULL; 3343 zonelist->_zonerefs[pos].zone_idx = 0; 3344 } 3345 3346 static int default_zonelist_order(void) 3347 { 3348 int nid, zone_type; 3349 unsigned long low_kmem_size,total_size; 3350 struct zone *z; 3351 int average_size; 3352 /* 3353 * ZONE_DMA and ZONE_DMA32 can be very small area in the system. 3354 * If they are really small and used heavily, the system can fall 3355 * into OOM very easily. 3356 * This function detect ZONE_DMA/DMA32 size and configures zone order. 3357 */ 3358 /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */ 3359 low_kmem_size = 0; 3360 total_size = 0; 3361 for_each_online_node(nid) { 3362 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 3363 z = &NODE_DATA(nid)->node_zones[zone_type]; 3364 if (populated_zone(z)) { 3365 if (zone_type < ZONE_NORMAL) 3366 low_kmem_size += z->present_pages; 3367 total_size += z->present_pages; 3368 } else if (zone_type == ZONE_NORMAL) { 3369 /* 3370 * If any node has only lowmem, then node order 3371 * is preferred to allow kernel allocations 3372 * locally; otherwise, they can easily infringe 3373 * on other nodes when there is an abundance of 3374 * lowmem available to allocate from. 3375 */ 3376 return ZONELIST_ORDER_NODE; 3377 } 3378 } 3379 } 3380 if (!low_kmem_size || /* there are no DMA area. */ 3381 low_kmem_size > total_size/2) /* DMA/DMA32 is big. */ 3382 return ZONELIST_ORDER_NODE; 3383 /* 3384 * look into each node's config. 3385 * If there is a node whose DMA/DMA32 memory is very big area on 3386 * local memory, NODE_ORDER may be suitable. 3387 */ 3388 average_size = total_size / 3389 (nodes_weight(node_states[N_MEMORY]) + 1); 3390 for_each_online_node(nid) { 3391 low_kmem_size = 0; 3392 total_size = 0; 3393 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) { 3394 z = &NODE_DATA(nid)->node_zones[zone_type]; 3395 if (populated_zone(z)) { 3396 if (zone_type < ZONE_NORMAL) 3397 low_kmem_size += z->present_pages; 3398 total_size += z->present_pages; 3399 } 3400 } 3401 if (low_kmem_size && 3402 total_size > average_size && /* ignore small node */ 3403 low_kmem_size > total_size * 70/100) 3404 return ZONELIST_ORDER_NODE; 3405 } 3406 return ZONELIST_ORDER_ZONE; 3407 } 3408 3409 static void set_zonelist_order(void) 3410 { 3411 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT) 3412 current_zonelist_order = default_zonelist_order(); 3413 else 3414 current_zonelist_order = user_zonelist_order; 3415 } 3416 3417 static void build_zonelists(pg_data_t *pgdat) 3418 { 3419 int j, node, load; 3420 enum zone_type i; 3421 nodemask_t used_mask; 3422 int local_node, prev_node; 3423 struct zonelist *zonelist; 3424 int order = current_zonelist_order; 3425 3426 /* initialize zonelists */ 3427 for (i = 0; i < MAX_ZONELISTS; i++) { 3428 zonelist = pgdat->node_zonelists + i; 3429 zonelist->_zonerefs[0].zone = NULL; 3430 zonelist->_zonerefs[0].zone_idx = 0; 3431 } 3432 3433 /* NUMA-aware ordering of nodes */ 3434 local_node = pgdat->node_id; 3435 load = nr_online_nodes; 3436 prev_node = local_node; 3437 nodes_clear(used_mask); 3438 3439 memset(node_order, 0, sizeof(node_order)); 3440 j = 0; 3441 3442 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 3443 /* 3444 * We don't want to pressure a particular node. 3445 * So adding penalty to the first node in same 3446 * distance group to make it round-robin. 3447 */ 3448 if (node_distance(local_node, node) != 3449 node_distance(local_node, prev_node)) 3450 node_load[node] = load; 3451 3452 prev_node = node; 3453 load--; 3454 if (order == ZONELIST_ORDER_NODE) 3455 build_zonelists_in_node_order(pgdat, node); 3456 else 3457 node_order[j++] = node; /* remember order */ 3458 } 3459 3460 if (order == ZONELIST_ORDER_ZONE) { 3461 /* calculate node order -- i.e., DMA last! */ 3462 build_zonelists_in_zone_order(pgdat, j); 3463 } 3464 3465 build_thisnode_zonelists(pgdat); 3466 } 3467 3468 /* Construct the zonelist performance cache - see further mmzone.h */ 3469 static void build_zonelist_cache(pg_data_t *pgdat) 3470 { 3471 struct zonelist *zonelist; 3472 struct zonelist_cache *zlc; 3473 struct zoneref *z; 3474 3475 zonelist = &pgdat->node_zonelists[0]; 3476 zonelist->zlcache_ptr = zlc = &zonelist->zlcache; 3477 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 3478 for (z = zonelist->_zonerefs; z->zone; z++) 3479 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z); 3480 } 3481 3482 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 3483 /* 3484 * Return node id of node used for "local" allocations. 3485 * I.e., first node id of first zone in arg node's generic zonelist. 3486 * Used for initializing percpu 'numa_mem', which is used primarily 3487 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist. 3488 */ 3489 int local_memory_node(int node) 3490 { 3491 struct zone *zone; 3492 3493 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL), 3494 gfp_zone(GFP_KERNEL), 3495 NULL, 3496 &zone); 3497 return zone->node; 3498 } 3499 #endif 3500 3501 #else /* CONFIG_NUMA */ 3502 3503 static void set_zonelist_order(void) 3504 { 3505 current_zonelist_order = ZONELIST_ORDER_ZONE; 3506 } 3507 3508 static void build_zonelists(pg_data_t *pgdat) 3509 { 3510 int node, local_node; 3511 enum zone_type j; 3512 struct zonelist *zonelist; 3513 3514 local_node = pgdat->node_id; 3515 3516 zonelist = &pgdat->node_zonelists[0]; 3517 j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); 3518 3519 /* 3520 * Now we build the zonelist so that it contains the zones 3521 * of all the other nodes. 3522 * We don't want to pressure a particular node, so when 3523 * building the zones for node N, we make sure that the 3524 * zones coming right after the local ones are those from 3525 * node N+1 (modulo N) 3526 */ 3527 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 3528 if (!node_online(node)) 3529 continue; 3530 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 3531 MAX_NR_ZONES - 1); 3532 } 3533 for (node = 0; node < local_node; node++) { 3534 if (!node_online(node)) 3535 continue; 3536 j = build_zonelists_node(NODE_DATA(node), zonelist, j, 3537 MAX_NR_ZONES - 1); 3538 } 3539 3540 zonelist->_zonerefs[j].zone = NULL; 3541 zonelist->_zonerefs[j].zone_idx = 0; 3542 } 3543 3544 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ 3545 static void build_zonelist_cache(pg_data_t *pgdat) 3546 { 3547 pgdat->node_zonelists[0].zlcache_ptr = NULL; 3548 } 3549 3550 #endif /* CONFIG_NUMA */ 3551 3552 /* 3553 * Boot pageset table. One per cpu which is going to be used for all 3554 * zones and all nodes. The parameters will be set in such a way 3555 * that an item put on a list will immediately be handed over to 3556 * the buddy list. This is safe since pageset manipulation is done 3557 * with interrupts disabled. 3558 * 3559 * The boot_pagesets must be kept even after bootup is complete for 3560 * unused processors and/or zones. They do play a role for bootstrapping 3561 * hotplugged processors. 3562 * 3563 * zoneinfo_show() and maybe other functions do 3564 * not check if the processor is online before following the pageset pointer. 3565 * Other parts of the kernel may not check if the zone is available. 3566 */ 3567 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch); 3568 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset); 3569 static void setup_zone_pageset(struct zone *zone); 3570 3571 /* 3572 * Global mutex to protect against size modification of zonelists 3573 * as well as to serialize pageset setup for the new populated zone. 3574 */ 3575 DEFINE_MUTEX(zonelists_mutex); 3576 3577 /* return values int ....just for stop_machine() */ 3578 static int __build_all_zonelists(void *data) 3579 { 3580 int nid; 3581 int cpu; 3582 pg_data_t *self = data; 3583 3584 #ifdef CONFIG_NUMA 3585 memset(node_load, 0, sizeof(node_load)); 3586 #endif 3587 3588 if (self && !node_online(self->node_id)) { 3589 build_zonelists(self); 3590 build_zonelist_cache(self); 3591 } 3592 3593 for_each_online_node(nid) { 3594 pg_data_t *pgdat = NODE_DATA(nid); 3595 3596 build_zonelists(pgdat); 3597 build_zonelist_cache(pgdat); 3598 } 3599 3600 /* 3601 * Initialize the boot_pagesets that are going to be used 3602 * for bootstrapping processors. The real pagesets for 3603 * each zone will be allocated later when the per cpu 3604 * allocator is available. 3605 * 3606 * boot_pagesets are used also for bootstrapping offline 3607 * cpus if the system is already booted because the pagesets 3608 * are needed to initialize allocators on a specific cpu too. 3609 * F.e. the percpu allocator needs the page allocator which 3610 * needs the percpu allocator in order to allocate its pagesets 3611 * (a chicken-egg dilemma). 3612 */ 3613 for_each_possible_cpu(cpu) { 3614 setup_pageset(&per_cpu(boot_pageset, cpu), 0); 3615 3616 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 3617 /* 3618 * We now know the "local memory node" for each node-- 3619 * i.e., the node of the first zone in the generic zonelist. 3620 * Set up numa_mem percpu variable for on-line cpus. During 3621 * boot, only the boot cpu should be on-line; we'll init the 3622 * secondary cpus' numa_mem as they come on-line. During 3623 * node/memory hotplug, we'll fixup all on-line cpus. 3624 */ 3625 if (cpu_online(cpu)) 3626 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu))); 3627 #endif 3628 } 3629 3630 return 0; 3631 } 3632 3633 /* 3634 * Called with zonelists_mutex held always 3635 * unless system_state == SYSTEM_BOOTING. 3636 */ 3637 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone) 3638 { 3639 set_zonelist_order(); 3640 3641 if (system_state == SYSTEM_BOOTING) { 3642 __build_all_zonelists(NULL); 3643 mminit_verify_zonelist(); 3644 cpuset_init_current_mems_allowed(); 3645 } else { 3646 /* we have to stop all cpus to guarantee there is no user 3647 of zonelist */ 3648 #ifdef CONFIG_MEMORY_HOTPLUG 3649 if (zone) 3650 setup_zone_pageset(zone); 3651 #endif 3652 stop_machine(__build_all_zonelists, pgdat, NULL); 3653 /* cpuset refresh routine should be here */ 3654 } 3655 vm_total_pages = nr_free_pagecache_pages(); 3656 /* 3657 * Disable grouping by mobility if the number of pages in the 3658 * system is too low to allow the mechanism to work. It would be 3659 * more accurate, but expensive to check per-zone. This check is 3660 * made on memory-hotadd so a system can start with mobility 3661 * disabled and enable it later 3662 */ 3663 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) 3664 page_group_by_mobility_disabled = 1; 3665 else 3666 page_group_by_mobility_disabled = 0; 3667 3668 printk("Built %i zonelists in %s order, mobility grouping %s. " 3669 "Total pages: %ld\n", 3670 nr_online_nodes, 3671 zonelist_order_name[current_zonelist_order], 3672 page_group_by_mobility_disabled ? "off" : "on", 3673 vm_total_pages); 3674 #ifdef CONFIG_NUMA 3675 printk("Policy zone: %s\n", zone_names[policy_zone]); 3676 #endif 3677 } 3678 3679 /* 3680 * Helper functions to size the waitqueue hash table. 3681 * Essentially these want to choose hash table sizes sufficiently 3682 * large so that collisions trying to wait on pages are rare. 3683 * But in fact, the number of active page waitqueues on typical 3684 * systems is ridiculously low, less than 200. So this is even 3685 * conservative, even though it seems large. 3686 * 3687 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 3688 * waitqueues, i.e. the size of the waitq table given the number of pages. 3689 */ 3690 #define PAGES_PER_WAITQUEUE 256 3691 3692 #ifndef CONFIG_MEMORY_HOTPLUG 3693 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 3694 { 3695 unsigned long size = 1; 3696 3697 pages /= PAGES_PER_WAITQUEUE; 3698 3699 while (size < pages) 3700 size <<= 1; 3701 3702 /* 3703 * Once we have dozens or even hundreds of threads sleeping 3704 * on IO we've got bigger problems than wait queue collision. 3705 * Limit the size of the wait table to a reasonable size. 3706 */ 3707 size = min(size, 4096UL); 3708 3709 return max(size, 4UL); 3710 } 3711 #else 3712 /* 3713 * A zone's size might be changed by hot-add, so it is not possible to determine 3714 * a suitable size for its wait_table. So we use the maximum size now. 3715 * 3716 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: 3717 * 3718 * i386 (preemption config) : 4096 x 16 = 64Kbyte. 3719 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. 3720 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. 3721 * 3722 * The maximum entries are prepared when a zone's memory is (512K + 256) pages 3723 * or more by the traditional way. (See above). It equals: 3724 * 3725 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. 3726 * ia64(16K page size) : = ( 8G + 4M)byte. 3727 * powerpc (64K page size) : = (32G +16M)byte. 3728 */ 3729 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 3730 { 3731 return 4096UL; 3732 } 3733 #endif 3734 3735 /* 3736 * This is an integer logarithm so that shifts can be used later 3737 * to extract the more random high bits from the multiplicative 3738 * hash function before the remainder is taken. 3739 */ 3740 static inline unsigned long wait_table_bits(unsigned long size) 3741 { 3742 return ffz(~size); 3743 } 3744 3745 #define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1)) 3746 3747 /* 3748 * Check if a pageblock contains reserved pages 3749 */ 3750 static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn) 3751 { 3752 unsigned long pfn; 3753 3754 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 3755 if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn))) 3756 return 1; 3757 } 3758 return 0; 3759 } 3760 3761 /* 3762 * Mark a number of pageblocks as MIGRATE_RESERVE. The number 3763 * of blocks reserved is based on min_wmark_pages(zone). The memory within 3764 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes 3765 * higher will lead to a bigger reserve which will get freed as contiguous 3766 * blocks as reclaim kicks in 3767 */ 3768 static void setup_zone_migrate_reserve(struct zone *zone) 3769 { 3770 unsigned long start_pfn, pfn, end_pfn, block_end_pfn; 3771 struct page *page; 3772 unsigned long block_migratetype; 3773 int reserve; 3774 3775 /* 3776 * Get the start pfn, end pfn and the number of blocks to reserve 3777 * We have to be careful to be aligned to pageblock_nr_pages to 3778 * make sure that we always check pfn_valid for the first page in 3779 * the block. 3780 */ 3781 start_pfn = zone->zone_start_pfn; 3782 end_pfn = start_pfn + zone->spanned_pages; 3783 start_pfn = roundup(start_pfn, pageblock_nr_pages); 3784 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >> 3785 pageblock_order; 3786 3787 /* 3788 * Reserve blocks are generally in place to help high-order atomic 3789 * allocations that are short-lived. A min_free_kbytes value that 3790 * would result in more than 2 reserve blocks for atomic allocations 3791 * is assumed to be in place to help anti-fragmentation for the 3792 * future allocation of hugepages at runtime. 3793 */ 3794 reserve = min(2, reserve); 3795 3796 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 3797 if (!pfn_valid(pfn)) 3798 continue; 3799 page = pfn_to_page(pfn); 3800 3801 /* Watch out for overlapping nodes */ 3802 if (page_to_nid(page) != zone_to_nid(zone)) 3803 continue; 3804 3805 block_migratetype = get_pageblock_migratetype(page); 3806 3807 /* Only test what is necessary when the reserves are not met */ 3808 if (reserve > 0) { 3809 /* 3810 * Blocks with reserved pages will never free, skip 3811 * them. 3812 */ 3813 block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn); 3814 if (pageblock_is_reserved(pfn, block_end_pfn)) 3815 continue; 3816 3817 /* If this block is reserved, account for it */ 3818 if (block_migratetype == MIGRATE_RESERVE) { 3819 reserve--; 3820 continue; 3821 } 3822 3823 /* Suitable for reserving if this block is movable */ 3824 if (block_migratetype == MIGRATE_MOVABLE) { 3825 set_pageblock_migratetype(page, 3826 MIGRATE_RESERVE); 3827 move_freepages_block(zone, page, 3828 MIGRATE_RESERVE); 3829 reserve--; 3830 continue; 3831 } 3832 } 3833 3834 /* 3835 * If the reserve is met and this is a previous reserved block, 3836 * take it back 3837 */ 3838 if (block_migratetype == MIGRATE_RESERVE) { 3839 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 3840 move_freepages_block(zone, page, MIGRATE_MOVABLE); 3841 } 3842 } 3843 } 3844 3845 /* 3846 * Initially all pages are reserved - free ones are freed 3847 * up by free_all_bootmem() once the early boot process is 3848 * done. Non-atomic initialization, single-pass. 3849 */ 3850 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 3851 unsigned long start_pfn, enum memmap_context context) 3852 { 3853 struct page *page; 3854 unsigned long end_pfn = start_pfn + size; 3855 unsigned long pfn; 3856 struct zone *z; 3857 3858 if (highest_memmap_pfn < end_pfn - 1) 3859 highest_memmap_pfn = end_pfn - 1; 3860 3861 z = &NODE_DATA(nid)->node_zones[zone]; 3862 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 3863 /* 3864 * There can be holes in boot-time mem_map[]s 3865 * handed to this function. They do not 3866 * exist on hotplugged memory. 3867 */ 3868 if (context == MEMMAP_EARLY) { 3869 if (!early_pfn_valid(pfn)) 3870 continue; 3871 if (!early_pfn_in_nid(pfn, nid)) 3872 continue; 3873 } 3874 page = pfn_to_page(pfn); 3875 set_page_links(page, zone, nid, pfn); 3876 mminit_verify_page_links(page, zone, nid, pfn); 3877 init_page_count(page); 3878 reset_page_mapcount(page); 3879 reset_page_last_nid(page); 3880 SetPageReserved(page); 3881 /* 3882 * Mark the block movable so that blocks are reserved for 3883 * movable at startup. This will force kernel allocations 3884 * to reserve their blocks rather than leaking throughout 3885 * the address space during boot when many long-lived 3886 * kernel allocations are made. Later some blocks near 3887 * the start are marked MIGRATE_RESERVE by 3888 * setup_zone_migrate_reserve() 3889 * 3890 * bitmap is created for zone's valid pfn range. but memmap 3891 * can be created for invalid pages (for alignment) 3892 * check here not to call set_pageblock_migratetype() against 3893 * pfn out of zone. 3894 */ 3895 if ((z->zone_start_pfn <= pfn) 3896 && (pfn < z->zone_start_pfn + z->spanned_pages) 3897 && !(pfn & (pageblock_nr_pages - 1))) 3898 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 3899 3900 INIT_LIST_HEAD(&page->lru); 3901 #ifdef WANT_PAGE_VIRTUAL 3902 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 3903 if (!is_highmem_idx(zone)) 3904 set_page_address(page, __va(pfn << PAGE_SHIFT)); 3905 #endif 3906 } 3907 } 3908 3909 static void __meminit zone_init_free_lists(struct zone *zone) 3910 { 3911 int order, t; 3912 for_each_migratetype_order(order, t) { 3913 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); 3914 zone->free_area[order].nr_free = 0; 3915 } 3916 } 3917 3918 #ifndef __HAVE_ARCH_MEMMAP_INIT 3919 #define memmap_init(size, nid, zone, start_pfn) \ 3920 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) 3921 #endif 3922 3923 static int __meminit zone_batchsize(struct zone *zone) 3924 { 3925 #ifdef CONFIG_MMU 3926 int batch; 3927 3928 /* 3929 * The per-cpu-pages pools are set to around 1000th of the 3930 * size of the zone. But no more than 1/2 of a meg. 3931 * 3932 * OK, so we don't know how big the cache is. So guess. 3933 */ 3934 batch = zone->present_pages / 1024; 3935 if (batch * PAGE_SIZE > 512 * 1024) 3936 batch = (512 * 1024) / PAGE_SIZE; 3937 batch /= 4; /* We effectively *= 4 below */ 3938 if (batch < 1) 3939 batch = 1; 3940 3941 /* 3942 * Clamp the batch to a 2^n - 1 value. Having a power 3943 * of 2 value was found to be more likely to have 3944 * suboptimal cache aliasing properties in some cases. 3945 * 3946 * For example if 2 tasks are alternately allocating 3947 * batches of pages, one task can end up with a lot 3948 * of pages of one half of the possible page colors 3949 * and the other with pages of the other colors. 3950 */ 3951 batch = rounddown_pow_of_two(batch + batch/2) - 1; 3952 3953 return batch; 3954 3955 #else 3956 /* The deferral and batching of frees should be suppressed under NOMMU 3957 * conditions. 3958 * 3959 * The problem is that NOMMU needs to be able to allocate large chunks 3960 * of contiguous memory as there's no hardware page translation to 3961 * assemble apparent contiguous memory from discontiguous pages. 3962 * 3963 * Queueing large contiguous runs of pages for batching, however, 3964 * causes the pages to actually be freed in smaller chunks. As there 3965 * can be a significant delay between the individual batches being 3966 * recycled, this leads to the once large chunks of space being 3967 * fragmented and becoming unavailable for high-order allocations. 3968 */ 3969 return 0; 3970 #endif 3971 } 3972 3973 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 3974 { 3975 struct per_cpu_pages *pcp; 3976 int migratetype; 3977 3978 memset(p, 0, sizeof(*p)); 3979 3980 pcp = &p->pcp; 3981 pcp->count = 0; 3982 pcp->high = 6 * batch; 3983 pcp->batch = max(1UL, 1 * batch); 3984 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++) 3985 INIT_LIST_HEAD(&pcp->lists[migratetype]); 3986 } 3987 3988 /* 3989 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist 3990 * to the value high for the pageset p. 3991 */ 3992 3993 static void setup_pagelist_highmark(struct per_cpu_pageset *p, 3994 unsigned long high) 3995 { 3996 struct per_cpu_pages *pcp; 3997 3998 pcp = &p->pcp; 3999 pcp->high = high; 4000 pcp->batch = max(1UL, high/4); 4001 if ((high/4) > (PAGE_SHIFT * 8)) 4002 pcp->batch = PAGE_SHIFT * 8; 4003 } 4004 4005 static void __meminit setup_zone_pageset(struct zone *zone) 4006 { 4007 int cpu; 4008 4009 zone->pageset = alloc_percpu(struct per_cpu_pageset); 4010 4011 for_each_possible_cpu(cpu) { 4012 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu); 4013 4014 setup_pageset(pcp, zone_batchsize(zone)); 4015 4016 if (percpu_pagelist_fraction) 4017 setup_pagelist_highmark(pcp, 4018 (zone->present_pages / 4019 percpu_pagelist_fraction)); 4020 } 4021 } 4022 4023 /* 4024 * Allocate per cpu pagesets and initialize them. 4025 * Before this call only boot pagesets were available. 4026 */ 4027 void __init setup_per_cpu_pageset(void) 4028 { 4029 struct zone *zone; 4030 4031 for_each_populated_zone(zone) 4032 setup_zone_pageset(zone); 4033 } 4034 4035 static noinline __init_refok 4036 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 4037 { 4038 int i; 4039 struct pglist_data *pgdat = zone->zone_pgdat; 4040 size_t alloc_size; 4041 4042 /* 4043 * The per-page waitqueue mechanism uses hashed waitqueues 4044 * per zone. 4045 */ 4046 zone->wait_table_hash_nr_entries = 4047 wait_table_hash_nr_entries(zone_size_pages); 4048 zone->wait_table_bits = 4049 wait_table_bits(zone->wait_table_hash_nr_entries); 4050 alloc_size = zone->wait_table_hash_nr_entries 4051 * sizeof(wait_queue_head_t); 4052 4053 if (!slab_is_available()) { 4054 zone->wait_table = (wait_queue_head_t *) 4055 alloc_bootmem_node_nopanic(pgdat, alloc_size); 4056 } else { 4057 /* 4058 * This case means that a zone whose size was 0 gets new memory 4059 * via memory hot-add. 4060 * But it may be the case that a new node was hot-added. In 4061 * this case vmalloc() will not be able to use this new node's 4062 * memory - this wait_table must be initialized to use this new 4063 * node itself as well. 4064 * To use this new node's memory, further consideration will be 4065 * necessary. 4066 */ 4067 zone->wait_table = vmalloc(alloc_size); 4068 } 4069 if (!zone->wait_table) 4070 return -ENOMEM; 4071 4072 for(i = 0; i < zone->wait_table_hash_nr_entries; ++i) 4073 init_waitqueue_head(zone->wait_table + i); 4074 4075 return 0; 4076 } 4077 4078 static __meminit void zone_pcp_init(struct zone *zone) 4079 { 4080 /* 4081 * per cpu subsystem is not up at this point. The following code 4082 * relies on the ability of the linker to provide the 4083 * offset of a (static) per cpu variable into the per cpu area. 4084 */ 4085 zone->pageset = &boot_pageset; 4086 4087 if (zone->present_pages) 4088 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n", 4089 zone->name, zone->present_pages, 4090 zone_batchsize(zone)); 4091 } 4092 4093 int __meminit init_currently_empty_zone(struct zone *zone, 4094 unsigned long zone_start_pfn, 4095 unsigned long size, 4096 enum memmap_context context) 4097 { 4098 struct pglist_data *pgdat = zone->zone_pgdat; 4099 int ret; 4100 ret = zone_wait_table_init(zone, size); 4101 if (ret) 4102 return ret; 4103 pgdat->nr_zones = zone_idx(zone) + 1; 4104 4105 zone->zone_start_pfn = zone_start_pfn; 4106 4107 mminit_dprintk(MMINIT_TRACE, "memmap_init", 4108 "Initialising map node %d zone %lu pfns %lu -> %lu\n", 4109 pgdat->node_id, 4110 (unsigned long)zone_idx(zone), 4111 zone_start_pfn, (zone_start_pfn + size)); 4112 4113 zone_init_free_lists(zone); 4114 4115 return 0; 4116 } 4117 4118 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 4119 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID 4120 /* 4121 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. 4122 * Architectures may implement their own version but if add_active_range() 4123 * was used and there are no special requirements, this is a convenient 4124 * alternative 4125 */ 4126 int __meminit __early_pfn_to_nid(unsigned long pfn) 4127 { 4128 unsigned long start_pfn, end_pfn; 4129 int i, nid; 4130 4131 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) 4132 if (start_pfn <= pfn && pfn < end_pfn) 4133 return nid; 4134 /* This is a memory hole */ 4135 return -1; 4136 } 4137 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ 4138 4139 int __meminit early_pfn_to_nid(unsigned long pfn) 4140 { 4141 int nid; 4142 4143 nid = __early_pfn_to_nid(pfn); 4144 if (nid >= 0) 4145 return nid; 4146 /* just returns 0 */ 4147 return 0; 4148 } 4149 4150 #ifdef CONFIG_NODES_SPAN_OTHER_NODES 4151 bool __meminit early_pfn_in_nid(unsigned long pfn, int node) 4152 { 4153 int nid; 4154 4155 nid = __early_pfn_to_nid(pfn); 4156 if (nid >= 0 && nid != node) 4157 return false; 4158 return true; 4159 } 4160 #endif 4161 4162 /** 4163 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range 4164 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. 4165 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node 4166 * 4167 * If an architecture guarantees that all ranges registered with 4168 * add_active_ranges() contain no holes and may be freed, this 4169 * this function may be used instead of calling free_bootmem() manually. 4170 */ 4171 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn) 4172 { 4173 unsigned long start_pfn, end_pfn; 4174 int i, this_nid; 4175 4176 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) { 4177 start_pfn = min(start_pfn, max_low_pfn); 4178 end_pfn = min(end_pfn, max_low_pfn); 4179 4180 if (start_pfn < end_pfn) 4181 free_bootmem_node(NODE_DATA(this_nid), 4182 PFN_PHYS(start_pfn), 4183 (end_pfn - start_pfn) << PAGE_SHIFT); 4184 } 4185 } 4186 4187 /** 4188 * sparse_memory_present_with_active_regions - Call memory_present for each active range 4189 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. 4190 * 4191 * If an architecture guarantees that all ranges registered with 4192 * add_active_ranges() contain no holes and may be freed, this 4193 * function may be used instead of calling memory_present() manually. 4194 */ 4195 void __init sparse_memory_present_with_active_regions(int nid) 4196 { 4197 unsigned long start_pfn, end_pfn; 4198 int i, this_nid; 4199 4200 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) 4201 memory_present(this_nid, start_pfn, end_pfn); 4202 } 4203 4204 /** 4205 * get_pfn_range_for_nid - Return the start and end page frames for a node 4206 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. 4207 * @start_pfn: Passed by reference. On return, it will have the node start_pfn. 4208 * @end_pfn: Passed by reference. On return, it will have the node end_pfn. 4209 * 4210 * It returns the start and end page frame of a node based on information 4211 * provided by an arch calling add_active_range(). If called for a node 4212 * with no available memory, a warning is printed and the start and end 4213 * PFNs will be 0. 4214 */ 4215 void __meminit get_pfn_range_for_nid(unsigned int nid, 4216 unsigned long *start_pfn, unsigned long *end_pfn) 4217 { 4218 unsigned long this_start_pfn, this_end_pfn; 4219 int i; 4220 4221 *start_pfn = -1UL; 4222 *end_pfn = 0; 4223 4224 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) { 4225 *start_pfn = min(*start_pfn, this_start_pfn); 4226 *end_pfn = max(*end_pfn, this_end_pfn); 4227 } 4228 4229 if (*start_pfn == -1UL) 4230 *start_pfn = 0; 4231 } 4232 4233 /* 4234 * This finds a zone that can be used for ZONE_MOVABLE pages. The 4235 * assumption is made that zones within a node are ordered in monotonic 4236 * increasing memory addresses so that the "highest" populated zone is used 4237 */ 4238 static void __init find_usable_zone_for_movable(void) 4239 { 4240 int zone_index; 4241 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { 4242 if (zone_index == ZONE_MOVABLE) 4243 continue; 4244 4245 if (arch_zone_highest_possible_pfn[zone_index] > 4246 arch_zone_lowest_possible_pfn[zone_index]) 4247 break; 4248 } 4249 4250 VM_BUG_ON(zone_index == -1); 4251 movable_zone = zone_index; 4252 } 4253 4254 /* 4255 * The zone ranges provided by the architecture do not include ZONE_MOVABLE 4256 * because it is sized independent of architecture. Unlike the other zones, 4257 * the starting point for ZONE_MOVABLE is not fixed. It may be different 4258 * in each node depending on the size of each node and how evenly kernelcore 4259 * is distributed. This helper function adjusts the zone ranges 4260 * provided by the architecture for a given node by using the end of the 4261 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that 4262 * zones within a node are in order of monotonic increases memory addresses 4263 */ 4264 static void __meminit adjust_zone_range_for_zone_movable(int nid, 4265 unsigned long zone_type, 4266 unsigned long node_start_pfn, 4267 unsigned long node_end_pfn, 4268 unsigned long *zone_start_pfn, 4269 unsigned long *zone_end_pfn) 4270 { 4271 /* Only adjust if ZONE_MOVABLE is on this node */ 4272 if (zone_movable_pfn[nid]) { 4273 /* Size ZONE_MOVABLE */ 4274 if (zone_type == ZONE_MOVABLE) { 4275 *zone_start_pfn = zone_movable_pfn[nid]; 4276 *zone_end_pfn = min(node_end_pfn, 4277 arch_zone_highest_possible_pfn[movable_zone]); 4278 4279 /* Adjust for ZONE_MOVABLE starting within this range */ 4280 } else if (*zone_start_pfn < zone_movable_pfn[nid] && 4281 *zone_end_pfn > zone_movable_pfn[nid]) { 4282 *zone_end_pfn = zone_movable_pfn[nid]; 4283 4284 /* Check if this whole range is within ZONE_MOVABLE */ 4285 } else if (*zone_start_pfn >= zone_movable_pfn[nid]) 4286 *zone_start_pfn = *zone_end_pfn; 4287 } 4288 } 4289 4290 /* 4291 * Return the number of pages a zone spans in a node, including holes 4292 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() 4293 */ 4294 static unsigned long __meminit zone_spanned_pages_in_node(int nid, 4295 unsigned long zone_type, 4296 unsigned long *ignored) 4297 { 4298 unsigned long node_start_pfn, node_end_pfn; 4299 unsigned long zone_start_pfn, zone_end_pfn; 4300 4301 /* Get the start and end of the node and zone */ 4302 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 4303 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; 4304 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; 4305 adjust_zone_range_for_zone_movable(nid, zone_type, 4306 node_start_pfn, node_end_pfn, 4307 &zone_start_pfn, &zone_end_pfn); 4308 4309 /* Check that this node has pages within the zone's required range */ 4310 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) 4311 return 0; 4312 4313 /* Move the zone boundaries inside the node if necessary */ 4314 zone_end_pfn = min(zone_end_pfn, node_end_pfn); 4315 zone_start_pfn = max(zone_start_pfn, node_start_pfn); 4316 4317 /* Return the spanned pages */ 4318 return zone_end_pfn - zone_start_pfn; 4319 } 4320 4321 /* 4322 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, 4323 * then all holes in the requested range will be accounted for. 4324 */ 4325 unsigned long __meminit __absent_pages_in_range(int nid, 4326 unsigned long range_start_pfn, 4327 unsigned long range_end_pfn) 4328 { 4329 unsigned long nr_absent = range_end_pfn - range_start_pfn; 4330 unsigned long start_pfn, end_pfn; 4331 int i; 4332 4333 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { 4334 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn); 4335 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn); 4336 nr_absent -= end_pfn - start_pfn; 4337 } 4338 return nr_absent; 4339 } 4340 4341 /** 4342 * absent_pages_in_range - Return number of page frames in holes within a range 4343 * @start_pfn: The start PFN to start searching for holes 4344 * @end_pfn: The end PFN to stop searching for holes 4345 * 4346 * It returns the number of pages frames in memory holes within a range. 4347 */ 4348 unsigned long __init absent_pages_in_range(unsigned long start_pfn, 4349 unsigned long end_pfn) 4350 { 4351 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); 4352 } 4353 4354 /* Return the number of page frames in holes in a zone on a node */ 4355 static unsigned long __meminit zone_absent_pages_in_node(int nid, 4356 unsigned long zone_type, 4357 unsigned long *ignored) 4358 { 4359 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type]; 4360 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type]; 4361 unsigned long node_start_pfn, node_end_pfn; 4362 unsigned long zone_start_pfn, zone_end_pfn; 4363 4364 get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn); 4365 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high); 4366 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high); 4367 4368 adjust_zone_range_for_zone_movable(nid, zone_type, 4369 node_start_pfn, node_end_pfn, 4370 &zone_start_pfn, &zone_end_pfn); 4371 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); 4372 } 4373 4374 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 4375 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, 4376 unsigned long zone_type, 4377 unsigned long *zones_size) 4378 { 4379 return zones_size[zone_type]; 4380 } 4381 4382 static inline unsigned long __meminit zone_absent_pages_in_node(int nid, 4383 unsigned long zone_type, 4384 unsigned long *zholes_size) 4385 { 4386 if (!zholes_size) 4387 return 0; 4388 4389 return zholes_size[zone_type]; 4390 } 4391 4392 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 4393 4394 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, 4395 unsigned long *zones_size, unsigned long *zholes_size) 4396 { 4397 unsigned long realtotalpages, totalpages = 0; 4398 enum zone_type i; 4399 4400 for (i = 0; i < MAX_NR_ZONES; i++) 4401 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i, 4402 zones_size); 4403 pgdat->node_spanned_pages = totalpages; 4404 4405 realtotalpages = totalpages; 4406 for (i = 0; i < MAX_NR_ZONES; i++) 4407 realtotalpages -= 4408 zone_absent_pages_in_node(pgdat->node_id, i, 4409 zholes_size); 4410 pgdat->node_present_pages = realtotalpages; 4411 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, 4412 realtotalpages); 4413 } 4414 4415 #ifndef CONFIG_SPARSEMEM 4416 /* 4417 * Calculate the size of the zone->blockflags rounded to an unsigned long 4418 * Start by making sure zonesize is a multiple of pageblock_order by rounding 4419 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally 4420 * round what is now in bits to nearest long in bits, then return it in 4421 * bytes. 4422 */ 4423 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize) 4424 { 4425 unsigned long usemapsize; 4426 4427 zonesize += zone_start_pfn & (pageblock_nr_pages-1); 4428 usemapsize = roundup(zonesize, pageblock_nr_pages); 4429 usemapsize = usemapsize >> pageblock_order; 4430 usemapsize *= NR_PAGEBLOCK_BITS; 4431 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); 4432 4433 return usemapsize / 8; 4434 } 4435 4436 static void __init setup_usemap(struct pglist_data *pgdat, 4437 struct zone *zone, 4438 unsigned long zone_start_pfn, 4439 unsigned long zonesize) 4440 { 4441 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize); 4442 zone->pageblock_flags = NULL; 4443 if (usemapsize) 4444 zone->pageblock_flags = alloc_bootmem_node_nopanic(pgdat, 4445 usemapsize); 4446 } 4447 #else 4448 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone, 4449 unsigned long zone_start_pfn, unsigned long zonesize) {} 4450 #endif /* CONFIG_SPARSEMEM */ 4451 4452 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 4453 4454 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ 4455 void __init set_pageblock_order(void) 4456 { 4457 unsigned int order; 4458 4459 /* Check that pageblock_nr_pages has not already been setup */ 4460 if (pageblock_order) 4461 return; 4462 4463 if (HPAGE_SHIFT > PAGE_SHIFT) 4464 order = HUGETLB_PAGE_ORDER; 4465 else 4466 order = MAX_ORDER - 1; 4467 4468 /* 4469 * Assume the largest contiguous order of interest is a huge page. 4470 * This value may be variable depending on boot parameters on IA64 and 4471 * powerpc. 4472 */ 4473 pageblock_order = order; 4474 } 4475 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 4476 4477 /* 4478 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() 4479 * is unused as pageblock_order is set at compile-time. See 4480 * include/linux/pageblock-flags.h for the values of pageblock_order based on 4481 * the kernel config 4482 */ 4483 void __init set_pageblock_order(void) 4484 { 4485 } 4486 4487 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 4488 4489 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages, 4490 unsigned long present_pages) 4491 { 4492 unsigned long pages = spanned_pages; 4493 4494 /* 4495 * Provide a more accurate estimation if there are holes within 4496 * the zone and SPARSEMEM is in use. If there are holes within the 4497 * zone, each populated memory region may cost us one or two extra 4498 * memmap pages due to alignment because memmap pages for each 4499 * populated regions may not naturally algined on page boundary. 4500 * So the (present_pages >> 4) heuristic is a tradeoff for that. 4501 */ 4502 if (spanned_pages > present_pages + (present_pages >> 4) && 4503 IS_ENABLED(CONFIG_SPARSEMEM)) 4504 pages = present_pages; 4505 4506 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT; 4507 } 4508 4509 /* 4510 * Set up the zone data structures: 4511 * - mark all pages reserved 4512 * - mark all memory queues empty 4513 * - clear the memory bitmaps 4514 * 4515 * NOTE: pgdat should get zeroed by caller. 4516 */ 4517 static void __paginginit free_area_init_core(struct pglist_data *pgdat, 4518 unsigned long *zones_size, unsigned long *zholes_size) 4519 { 4520 enum zone_type j; 4521 int nid = pgdat->node_id; 4522 unsigned long zone_start_pfn = pgdat->node_start_pfn; 4523 int ret; 4524 4525 pgdat_resize_init(pgdat); 4526 #ifdef CONFIG_NUMA_BALANCING 4527 spin_lock_init(&pgdat->numabalancing_migrate_lock); 4528 pgdat->numabalancing_migrate_nr_pages = 0; 4529 pgdat->numabalancing_migrate_next_window = jiffies; 4530 #endif 4531 init_waitqueue_head(&pgdat->kswapd_wait); 4532 init_waitqueue_head(&pgdat->pfmemalloc_wait); 4533 pgdat_page_cgroup_init(pgdat); 4534 4535 for (j = 0; j < MAX_NR_ZONES; j++) { 4536 struct zone *zone = pgdat->node_zones + j; 4537 unsigned long size, realsize, freesize, memmap_pages; 4538 4539 size = zone_spanned_pages_in_node(nid, j, zones_size); 4540 realsize = freesize = size - zone_absent_pages_in_node(nid, j, 4541 zholes_size); 4542 4543 /* 4544 * Adjust freesize so that it accounts for how much memory 4545 * is used by this zone for memmap. This affects the watermark 4546 * and per-cpu initialisations 4547 */ 4548 memmap_pages = calc_memmap_size(size, realsize); 4549 if (freesize >= memmap_pages) { 4550 freesize -= memmap_pages; 4551 if (memmap_pages) 4552 printk(KERN_DEBUG 4553 " %s zone: %lu pages used for memmap\n", 4554 zone_names[j], memmap_pages); 4555 } else 4556 printk(KERN_WARNING 4557 " %s zone: %lu pages exceeds freesize %lu\n", 4558 zone_names[j], memmap_pages, freesize); 4559 4560 /* Account for reserved pages */ 4561 if (j == 0 && freesize > dma_reserve) { 4562 freesize -= dma_reserve; 4563 printk(KERN_DEBUG " %s zone: %lu pages reserved\n", 4564 zone_names[0], dma_reserve); 4565 } 4566 4567 if (!is_highmem_idx(j)) 4568 nr_kernel_pages += freesize; 4569 /* Charge for highmem memmap if there are enough kernel pages */ 4570 else if (nr_kernel_pages > memmap_pages * 2) 4571 nr_kernel_pages -= memmap_pages; 4572 nr_all_pages += freesize; 4573 4574 zone->spanned_pages = size; 4575 zone->present_pages = freesize; 4576 /* 4577 * Set an approximate value for lowmem here, it will be adjusted 4578 * when the bootmem allocator frees pages into the buddy system. 4579 * And all highmem pages will be managed by the buddy system. 4580 */ 4581 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize; 4582 #ifdef CONFIG_NUMA 4583 zone->node = nid; 4584 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio) 4585 / 100; 4586 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100; 4587 #endif 4588 zone->name = zone_names[j]; 4589 spin_lock_init(&zone->lock); 4590 spin_lock_init(&zone->lru_lock); 4591 zone_seqlock_init(zone); 4592 zone->zone_pgdat = pgdat; 4593 4594 zone_pcp_init(zone); 4595 lruvec_init(&zone->lruvec); 4596 if (!size) 4597 continue; 4598 4599 set_pageblock_order(); 4600 setup_usemap(pgdat, zone, zone_start_pfn, size); 4601 ret = init_currently_empty_zone(zone, zone_start_pfn, 4602 size, MEMMAP_EARLY); 4603 BUG_ON(ret); 4604 memmap_init(size, nid, j, zone_start_pfn); 4605 zone_start_pfn += size; 4606 } 4607 } 4608 4609 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat) 4610 { 4611 /* Skip empty nodes */ 4612 if (!pgdat->node_spanned_pages) 4613 return; 4614 4615 #ifdef CONFIG_FLAT_NODE_MEM_MAP 4616 /* ia64 gets its own node_mem_map, before this, without bootmem */ 4617 if (!pgdat->node_mem_map) { 4618 unsigned long size, start, end; 4619 struct page *map; 4620 4621 /* 4622 * The zone's endpoints aren't required to be MAX_ORDER 4623 * aligned but the node_mem_map endpoints must be in order 4624 * for the buddy allocator to function correctly. 4625 */ 4626 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); 4627 end = pgdat->node_start_pfn + pgdat->node_spanned_pages; 4628 end = ALIGN(end, MAX_ORDER_NR_PAGES); 4629 size = (end - start) * sizeof(struct page); 4630 map = alloc_remap(pgdat->node_id, size); 4631 if (!map) 4632 map = alloc_bootmem_node_nopanic(pgdat, size); 4633 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); 4634 } 4635 #ifndef CONFIG_NEED_MULTIPLE_NODES 4636 /* 4637 * With no DISCONTIG, the global mem_map is just set as node 0's 4638 */ 4639 if (pgdat == NODE_DATA(0)) { 4640 mem_map = NODE_DATA(0)->node_mem_map; 4641 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 4642 if (page_to_pfn(mem_map) != pgdat->node_start_pfn) 4643 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET); 4644 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 4645 } 4646 #endif 4647 #endif /* CONFIG_FLAT_NODE_MEM_MAP */ 4648 } 4649 4650 void __paginginit free_area_init_node(int nid, unsigned long *zones_size, 4651 unsigned long node_start_pfn, unsigned long *zholes_size) 4652 { 4653 pg_data_t *pgdat = NODE_DATA(nid); 4654 4655 /* pg_data_t should be reset to zero when it's allocated */ 4656 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx); 4657 4658 pgdat->node_id = nid; 4659 pgdat->node_start_pfn = node_start_pfn; 4660 init_zone_allows_reclaim(nid); 4661 calculate_node_totalpages(pgdat, zones_size, zholes_size); 4662 4663 alloc_node_mem_map(pgdat); 4664 #ifdef CONFIG_FLAT_NODE_MEM_MAP 4665 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n", 4666 nid, (unsigned long)pgdat, 4667 (unsigned long)pgdat->node_mem_map); 4668 #endif 4669 4670 free_area_init_core(pgdat, zones_size, zholes_size); 4671 } 4672 4673 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 4674 4675 #if MAX_NUMNODES > 1 4676 /* 4677 * Figure out the number of possible node ids. 4678 */ 4679 static void __init setup_nr_node_ids(void) 4680 { 4681 unsigned int node; 4682 unsigned int highest = 0; 4683 4684 for_each_node_mask(node, node_possible_map) 4685 highest = node; 4686 nr_node_ids = highest + 1; 4687 } 4688 #else 4689 static inline void setup_nr_node_ids(void) 4690 { 4691 } 4692 #endif 4693 4694 /** 4695 * node_map_pfn_alignment - determine the maximum internode alignment 4696 * 4697 * This function should be called after node map is populated and sorted. 4698 * It calculates the maximum power of two alignment which can distinguish 4699 * all the nodes. 4700 * 4701 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value 4702 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the 4703 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is 4704 * shifted, 1GiB is enough and this function will indicate so. 4705 * 4706 * This is used to test whether pfn -> nid mapping of the chosen memory 4707 * model has fine enough granularity to avoid incorrect mapping for the 4708 * populated node map. 4709 * 4710 * Returns the determined alignment in pfn's. 0 if there is no alignment 4711 * requirement (single node). 4712 */ 4713 unsigned long __init node_map_pfn_alignment(void) 4714 { 4715 unsigned long accl_mask = 0, last_end = 0; 4716 unsigned long start, end, mask; 4717 int last_nid = -1; 4718 int i, nid; 4719 4720 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) { 4721 if (!start || last_nid < 0 || last_nid == nid) { 4722 last_nid = nid; 4723 last_end = end; 4724 continue; 4725 } 4726 4727 /* 4728 * Start with a mask granular enough to pin-point to the 4729 * start pfn and tick off bits one-by-one until it becomes 4730 * too coarse to separate the current node from the last. 4731 */ 4732 mask = ~((1 << __ffs(start)) - 1); 4733 while (mask && last_end <= (start & (mask << 1))) 4734 mask <<= 1; 4735 4736 /* accumulate all internode masks */ 4737 accl_mask |= mask; 4738 } 4739 4740 /* convert mask to number of pages */ 4741 return ~accl_mask + 1; 4742 } 4743 4744 /* Find the lowest pfn for a node */ 4745 static unsigned long __init find_min_pfn_for_node(int nid) 4746 { 4747 unsigned long min_pfn = ULONG_MAX; 4748 unsigned long start_pfn; 4749 int i; 4750 4751 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL) 4752 min_pfn = min(min_pfn, start_pfn); 4753 4754 if (min_pfn == ULONG_MAX) { 4755 printk(KERN_WARNING 4756 "Could not find start_pfn for node %d\n", nid); 4757 return 0; 4758 } 4759 4760 return min_pfn; 4761 } 4762 4763 /** 4764 * find_min_pfn_with_active_regions - Find the minimum PFN registered 4765 * 4766 * It returns the minimum PFN based on information provided via 4767 * add_active_range(). 4768 */ 4769 unsigned long __init find_min_pfn_with_active_regions(void) 4770 { 4771 return find_min_pfn_for_node(MAX_NUMNODES); 4772 } 4773 4774 /* 4775 * early_calculate_totalpages() 4776 * Sum pages in active regions for movable zone. 4777 * Populate N_MEMORY for calculating usable_nodes. 4778 */ 4779 static unsigned long __init early_calculate_totalpages(void) 4780 { 4781 unsigned long totalpages = 0; 4782 unsigned long start_pfn, end_pfn; 4783 int i, nid; 4784 4785 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { 4786 unsigned long pages = end_pfn - start_pfn; 4787 4788 totalpages += pages; 4789 if (pages) 4790 node_set_state(nid, N_MEMORY); 4791 } 4792 return totalpages; 4793 } 4794 4795 /* 4796 * Find the PFN the Movable zone begins in each node. Kernel memory 4797 * is spread evenly between nodes as long as the nodes have enough 4798 * memory. When they don't, some nodes will have more kernelcore than 4799 * others 4800 */ 4801 static void __init find_zone_movable_pfns_for_nodes(void) 4802 { 4803 int i, nid; 4804 unsigned long usable_startpfn; 4805 unsigned long kernelcore_node, kernelcore_remaining; 4806 /* save the state before borrow the nodemask */ 4807 nodemask_t saved_node_state = node_states[N_MEMORY]; 4808 unsigned long totalpages = early_calculate_totalpages(); 4809 int usable_nodes = nodes_weight(node_states[N_MEMORY]); 4810 4811 /* 4812 * If movablecore was specified, calculate what size of 4813 * kernelcore that corresponds so that memory usable for 4814 * any allocation type is evenly spread. If both kernelcore 4815 * and movablecore are specified, then the value of kernelcore 4816 * will be used for required_kernelcore if it's greater than 4817 * what movablecore would have allowed. 4818 */ 4819 if (required_movablecore) { 4820 unsigned long corepages; 4821 4822 /* 4823 * Round-up so that ZONE_MOVABLE is at least as large as what 4824 * was requested by the user 4825 */ 4826 required_movablecore = 4827 roundup(required_movablecore, MAX_ORDER_NR_PAGES); 4828 corepages = totalpages - required_movablecore; 4829 4830 required_kernelcore = max(required_kernelcore, corepages); 4831 } 4832 4833 /* If kernelcore was not specified, there is no ZONE_MOVABLE */ 4834 if (!required_kernelcore) 4835 goto out; 4836 4837 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ 4838 find_usable_zone_for_movable(); 4839 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; 4840 4841 restart: 4842 /* Spread kernelcore memory as evenly as possible throughout nodes */ 4843 kernelcore_node = required_kernelcore / usable_nodes; 4844 for_each_node_state(nid, N_MEMORY) { 4845 unsigned long start_pfn, end_pfn; 4846 4847 /* 4848 * Recalculate kernelcore_node if the division per node 4849 * now exceeds what is necessary to satisfy the requested 4850 * amount of memory for the kernel 4851 */ 4852 if (required_kernelcore < kernelcore_node) 4853 kernelcore_node = required_kernelcore / usable_nodes; 4854 4855 /* 4856 * As the map is walked, we track how much memory is usable 4857 * by the kernel using kernelcore_remaining. When it is 4858 * 0, the rest of the node is usable by ZONE_MOVABLE 4859 */ 4860 kernelcore_remaining = kernelcore_node; 4861 4862 /* Go through each range of PFNs within this node */ 4863 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { 4864 unsigned long size_pages; 4865 4866 start_pfn = max(start_pfn, zone_movable_pfn[nid]); 4867 if (start_pfn >= end_pfn) 4868 continue; 4869 4870 /* Account for what is only usable for kernelcore */ 4871 if (start_pfn < usable_startpfn) { 4872 unsigned long kernel_pages; 4873 kernel_pages = min(end_pfn, usable_startpfn) 4874 - start_pfn; 4875 4876 kernelcore_remaining -= min(kernel_pages, 4877 kernelcore_remaining); 4878 required_kernelcore -= min(kernel_pages, 4879 required_kernelcore); 4880 4881 /* Continue if range is now fully accounted */ 4882 if (end_pfn <= usable_startpfn) { 4883 4884 /* 4885 * Push zone_movable_pfn to the end so 4886 * that if we have to rebalance 4887 * kernelcore across nodes, we will 4888 * not double account here 4889 */ 4890 zone_movable_pfn[nid] = end_pfn; 4891 continue; 4892 } 4893 start_pfn = usable_startpfn; 4894 } 4895 4896 /* 4897 * The usable PFN range for ZONE_MOVABLE is from 4898 * start_pfn->end_pfn. Calculate size_pages as the 4899 * number of pages used as kernelcore 4900 */ 4901 size_pages = end_pfn - start_pfn; 4902 if (size_pages > kernelcore_remaining) 4903 size_pages = kernelcore_remaining; 4904 zone_movable_pfn[nid] = start_pfn + size_pages; 4905 4906 /* 4907 * Some kernelcore has been met, update counts and 4908 * break if the kernelcore for this node has been 4909 * satisified 4910 */ 4911 required_kernelcore -= min(required_kernelcore, 4912 size_pages); 4913 kernelcore_remaining -= size_pages; 4914 if (!kernelcore_remaining) 4915 break; 4916 } 4917 } 4918 4919 /* 4920 * If there is still required_kernelcore, we do another pass with one 4921 * less node in the count. This will push zone_movable_pfn[nid] further 4922 * along on the nodes that still have memory until kernelcore is 4923 * satisified 4924 */ 4925 usable_nodes--; 4926 if (usable_nodes && required_kernelcore > usable_nodes) 4927 goto restart; 4928 4929 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ 4930 for (nid = 0; nid < MAX_NUMNODES; nid++) 4931 zone_movable_pfn[nid] = 4932 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); 4933 4934 out: 4935 /* restore the node_state */ 4936 node_states[N_MEMORY] = saved_node_state; 4937 } 4938 4939 /* Any regular or high memory on that node ? */ 4940 static void check_for_memory(pg_data_t *pgdat, int nid) 4941 { 4942 enum zone_type zone_type; 4943 4944 if (N_MEMORY == N_NORMAL_MEMORY) 4945 return; 4946 4947 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) { 4948 struct zone *zone = &pgdat->node_zones[zone_type]; 4949 if (zone->present_pages) { 4950 node_set_state(nid, N_HIGH_MEMORY); 4951 if (N_NORMAL_MEMORY != N_HIGH_MEMORY && 4952 zone_type <= ZONE_NORMAL) 4953 node_set_state(nid, N_NORMAL_MEMORY); 4954 break; 4955 } 4956 } 4957 } 4958 4959 /** 4960 * free_area_init_nodes - Initialise all pg_data_t and zone data 4961 * @max_zone_pfn: an array of max PFNs for each zone 4962 * 4963 * This will call free_area_init_node() for each active node in the system. 4964 * Using the page ranges provided by add_active_range(), the size of each 4965 * zone in each node and their holes is calculated. If the maximum PFN 4966 * between two adjacent zones match, it is assumed that the zone is empty. 4967 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed 4968 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone 4969 * starts where the previous one ended. For example, ZONE_DMA32 starts 4970 * at arch_max_dma_pfn. 4971 */ 4972 void __init free_area_init_nodes(unsigned long *max_zone_pfn) 4973 { 4974 unsigned long start_pfn, end_pfn; 4975 int i, nid; 4976 4977 /* Record where the zone boundaries are */ 4978 memset(arch_zone_lowest_possible_pfn, 0, 4979 sizeof(arch_zone_lowest_possible_pfn)); 4980 memset(arch_zone_highest_possible_pfn, 0, 4981 sizeof(arch_zone_highest_possible_pfn)); 4982 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); 4983 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; 4984 for (i = 1; i < MAX_NR_ZONES; i++) { 4985 if (i == ZONE_MOVABLE) 4986 continue; 4987 arch_zone_lowest_possible_pfn[i] = 4988 arch_zone_highest_possible_pfn[i-1]; 4989 arch_zone_highest_possible_pfn[i] = 4990 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); 4991 } 4992 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0; 4993 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0; 4994 4995 /* Find the PFNs that ZONE_MOVABLE begins at in each node */ 4996 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); 4997 find_zone_movable_pfns_for_nodes(); 4998 4999 /* Print out the zone ranges */ 5000 printk("Zone ranges:\n"); 5001 for (i = 0; i < MAX_NR_ZONES; i++) { 5002 if (i == ZONE_MOVABLE) 5003 continue; 5004 printk(KERN_CONT " %-8s ", zone_names[i]); 5005 if (arch_zone_lowest_possible_pfn[i] == 5006 arch_zone_highest_possible_pfn[i]) 5007 printk(KERN_CONT "empty\n"); 5008 else 5009 printk(KERN_CONT "[mem %0#10lx-%0#10lx]\n", 5010 arch_zone_lowest_possible_pfn[i] << PAGE_SHIFT, 5011 (arch_zone_highest_possible_pfn[i] 5012 << PAGE_SHIFT) - 1); 5013 } 5014 5015 /* Print out the PFNs ZONE_MOVABLE begins at in each node */ 5016 printk("Movable zone start for each node\n"); 5017 for (i = 0; i < MAX_NUMNODES; i++) { 5018 if (zone_movable_pfn[i]) 5019 printk(" Node %d: %#010lx\n", i, 5020 zone_movable_pfn[i] << PAGE_SHIFT); 5021 } 5022 5023 /* Print out the early node map */ 5024 printk("Early memory node ranges\n"); 5025 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) 5026 printk(" node %3d: [mem %#010lx-%#010lx]\n", nid, 5027 start_pfn << PAGE_SHIFT, (end_pfn << PAGE_SHIFT) - 1); 5028 5029 /* Initialise every node */ 5030 mminit_verify_pageflags_layout(); 5031 setup_nr_node_ids(); 5032 for_each_online_node(nid) { 5033 pg_data_t *pgdat = NODE_DATA(nid); 5034 free_area_init_node(nid, NULL, 5035 find_min_pfn_for_node(nid), NULL); 5036 5037 /* Any memory on that node */ 5038 if (pgdat->node_present_pages) 5039 node_set_state(nid, N_MEMORY); 5040 check_for_memory(pgdat, nid); 5041 } 5042 } 5043 5044 static int __init cmdline_parse_core(char *p, unsigned long *core) 5045 { 5046 unsigned long long coremem; 5047 if (!p) 5048 return -EINVAL; 5049 5050 coremem = memparse(p, &p); 5051 *core = coremem >> PAGE_SHIFT; 5052 5053 /* Paranoid check that UL is enough for the coremem value */ 5054 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); 5055 5056 return 0; 5057 } 5058 5059 /* 5060 * kernelcore=size sets the amount of memory for use for allocations that 5061 * cannot be reclaimed or migrated. 5062 */ 5063 static int __init cmdline_parse_kernelcore(char *p) 5064 { 5065 return cmdline_parse_core(p, &required_kernelcore); 5066 } 5067 5068 /* 5069 * movablecore=size sets the amount of memory for use for allocations that 5070 * can be reclaimed or migrated. 5071 */ 5072 static int __init cmdline_parse_movablecore(char *p) 5073 { 5074 return cmdline_parse_core(p, &required_movablecore); 5075 } 5076 5077 early_param("kernelcore", cmdline_parse_kernelcore); 5078 early_param("movablecore", cmdline_parse_movablecore); 5079 5080 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 5081 5082 /** 5083 * set_dma_reserve - set the specified number of pages reserved in the first zone 5084 * @new_dma_reserve: The number of pages to mark reserved 5085 * 5086 * The per-cpu batchsize and zone watermarks are determined by present_pages. 5087 * In the DMA zone, a significant percentage may be consumed by kernel image 5088 * and other unfreeable allocations which can skew the watermarks badly. This 5089 * function may optionally be used to account for unfreeable pages in the 5090 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and 5091 * smaller per-cpu batchsize. 5092 */ 5093 void __init set_dma_reserve(unsigned long new_dma_reserve) 5094 { 5095 dma_reserve = new_dma_reserve; 5096 } 5097 5098 void __init free_area_init(unsigned long *zones_size) 5099 { 5100 free_area_init_node(0, zones_size, 5101 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 5102 } 5103 5104 static int page_alloc_cpu_notify(struct notifier_block *self, 5105 unsigned long action, void *hcpu) 5106 { 5107 int cpu = (unsigned long)hcpu; 5108 5109 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { 5110 lru_add_drain_cpu(cpu); 5111 drain_pages(cpu); 5112 5113 /* 5114 * Spill the event counters of the dead processor 5115 * into the current processors event counters. 5116 * This artificially elevates the count of the current 5117 * processor. 5118 */ 5119 vm_events_fold_cpu(cpu); 5120 5121 /* 5122 * Zero the differential counters of the dead processor 5123 * so that the vm statistics are consistent. 5124 * 5125 * This is only okay since the processor is dead and cannot 5126 * race with what we are doing. 5127 */ 5128 refresh_cpu_vm_stats(cpu); 5129 } 5130 return NOTIFY_OK; 5131 } 5132 5133 void __init page_alloc_init(void) 5134 { 5135 hotcpu_notifier(page_alloc_cpu_notify, 0); 5136 } 5137 5138 /* 5139 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio 5140 * or min_free_kbytes changes. 5141 */ 5142 static void calculate_totalreserve_pages(void) 5143 { 5144 struct pglist_data *pgdat; 5145 unsigned long reserve_pages = 0; 5146 enum zone_type i, j; 5147 5148 for_each_online_pgdat(pgdat) { 5149 for (i = 0; i < MAX_NR_ZONES; i++) { 5150 struct zone *zone = pgdat->node_zones + i; 5151 unsigned long max = 0; 5152 5153 /* Find valid and maximum lowmem_reserve in the zone */ 5154 for (j = i; j < MAX_NR_ZONES; j++) { 5155 if (zone->lowmem_reserve[j] > max) 5156 max = zone->lowmem_reserve[j]; 5157 } 5158 5159 /* we treat the high watermark as reserved pages. */ 5160 max += high_wmark_pages(zone); 5161 5162 if (max > zone->present_pages) 5163 max = zone->present_pages; 5164 reserve_pages += max; 5165 /* 5166 * Lowmem reserves are not available to 5167 * GFP_HIGHUSER page cache allocations and 5168 * kswapd tries to balance zones to their high 5169 * watermark. As a result, neither should be 5170 * regarded as dirtyable memory, to prevent a 5171 * situation where reclaim has to clean pages 5172 * in order to balance the zones. 5173 */ 5174 zone->dirty_balance_reserve = max; 5175 } 5176 } 5177 dirty_balance_reserve = reserve_pages; 5178 totalreserve_pages = reserve_pages; 5179 } 5180 5181 /* 5182 * setup_per_zone_lowmem_reserve - called whenever 5183 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 5184 * has a correct pages reserved value, so an adequate number of 5185 * pages are left in the zone after a successful __alloc_pages(). 5186 */ 5187 static void setup_per_zone_lowmem_reserve(void) 5188 { 5189 struct pglist_data *pgdat; 5190 enum zone_type j, idx; 5191 5192 for_each_online_pgdat(pgdat) { 5193 for (j = 0; j < MAX_NR_ZONES; j++) { 5194 struct zone *zone = pgdat->node_zones + j; 5195 unsigned long present_pages = zone->present_pages; 5196 5197 zone->lowmem_reserve[j] = 0; 5198 5199 idx = j; 5200 while (idx) { 5201 struct zone *lower_zone; 5202 5203 idx--; 5204 5205 if (sysctl_lowmem_reserve_ratio[idx] < 1) 5206 sysctl_lowmem_reserve_ratio[idx] = 1; 5207 5208 lower_zone = pgdat->node_zones + idx; 5209 lower_zone->lowmem_reserve[j] = present_pages / 5210 sysctl_lowmem_reserve_ratio[idx]; 5211 present_pages += lower_zone->present_pages; 5212 } 5213 } 5214 } 5215 5216 /* update totalreserve_pages */ 5217 calculate_totalreserve_pages(); 5218 } 5219 5220 static void __setup_per_zone_wmarks(void) 5221 { 5222 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 5223 unsigned long lowmem_pages = 0; 5224 struct zone *zone; 5225 unsigned long flags; 5226 5227 /* Calculate total number of !ZONE_HIGHMEM pages */ 5228 for_each_zone(zone) { 5229 if (!is_highmem(zone)) 5230 lowmem_pages += zone->present_pages; 5231 } 5232 5233 for_each_zone(zone) { 5234 u64 tmp; 5235 5236 spin_lock_irqsave(&zone->lock, flags); 5237 tmp = (u64)pages_min * zone->present_pages; 5238 do_div(tmp, lowmem_pages); 5239 if (is_highmem(zone)) { 5240 /* 5241 * __GFP_HIGH and PF_MEMALLOC allocations usually don't 5242 * need highmem pages, so cap pages_min to a small 5243 * value here. 5244 * 5245 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN) 5246 * deltas controls asynch page reclaim, and so should 5247 * not be capped for highmem. 5248 */ 5249 int min_pages; 5250 5251 min_pages = zone->present_pages / 1024; 5252 if (min_pages < SWAP_CLUSTER_MAX) 5253 min_pages = SWAP_CLUSTER_MAX; 5254 if (min_pages > 128) 5255 min_pages = 128; 5256 zone->watermark[WMARK_MIN] = min_pages; 5257 } else { 5258 /* 5259 * If it's a lowmem zone, reserve a number of pages 5260 * proportionate to the zone's size. 5261 */ 5262 zone->watermark[WMARK_MIN] = tmp; 5263 } 5264 5265 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2); 5266 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1); 5267 5268 setup_zone_migrate_reserve(zone); 5269 spin_unlock_irqrestore(&zone->lock, flags); 5270 } 5271 5272 /* update totalreserve_pages */ 5273 calculate_totalreserve_pages(); 5274 } 5275 5276 /** 5277 * setup_per_zone_wmarks - called when min_free_kbytes changes 5278 * or when memory is hot-{added|removed} 5279 * 5280 * Ensures that the watermark[min,low,high] values for each zone are set 5281 * correctly with respect to min_free_kbytes. 5282 */ 5283 void setup_per_zone_wmarks(void) 5284 { 5285 mutex_lock(&zonelists_mutex); 5286 __setup_per_zone_wmarks(); 5287 mutex_unlock(&zonelists_mutex); 5288 } 5289 5290 /* 5291 * The inactive anon list should be small enough that the VM never has to 5292 * do too much work, but large enough that each inactive page has a chance 5293 * to be referenced again before it is swapped out. 5294 * 5295 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to 5296 * INACTIVE_ANON pages on this zone's LRU, maintained by the 5297 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of 5298 * the anonymous pages are kept on the inactive list. 5299 * 5300 * total target max 5301 * memory ratio inactive anon 5302 * ------------------------------------- 5303 * 10MB 1 5MB 5304 * 100MB 1 50MB 5305 * 1GB 3 250MB 5306 * 10GB 10 0.9GB 5307 * 100GB 31 3GB 5308 * 1TB 101 10GB 5309 * 10TB 320 32GB 5310 */ 5311 static void __meminit calculate_zone_inactive_ratio(struct zone *zone) 5312 { 5313 unsigned int gb, ratio; 5314 5315 /* Zone size in gigabytes */ 5316 gb = zone->present_pages >> (30 - PAGE_SHIFT); 5317 if (gb) 5318 ratio = int_sqrt(10 * gb); 5319 else 5320 ratio = 1; 5321 5322 zone->inactive_ratio = ratio; 5323 } 5324 5325 static void __meminit setup_per_zone_inactive_ratio(void) 5326 { 5327 struct zone *zone; 5328 5329 for_each_zone(zone) 5330 calculate_zone_inactive_ratio(zone); 5331 } 5332 5333 /* 5334 * Initialise min_free_kbytes. 5335 * 5336 * For small machines we want it small (128k min). For large machines 5337 * we want it large (64MB max). But it is not linear, because network 5338 * bandwidth does not increase linearly with machine size. We use 5339 * 5340 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 5341 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 5342 * 5343 * which yields 5344 * 5345 * 16MB: 512k 5346 * 32MB: 724k 5347 * 64MB: 1024k 5348 * 128MB: 1448k 5349 * 256MB: 2048k 5350 * 512MB: 2896k 5351 * 1024MB: 4096k 5352 * 2048MB: 5792k 5353 * 4096MB: 8192k 5354 * 8192MB: 11584k 5355 * 16384MB: 16384k 5356 */ 5357 int __meminit init_per_zone_wmark_min(void) 5358 { 5359 unsigned long lowmem_kbytes; 5360 5361 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 5362 5363 min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 5364 if (min_free_kbytes < 128) 5365 min_free_kbytes = 128; 5366 if (min_free_kbytes > 65536) 5367 min_free_kbytes = 65536; 5368 setup_per_zone_wmarks(); 5369 refresh_zone_stat_thresholds(); 5370 setup_per_zone_lowmem_reserve(); 5371 setup_per_zone_inactive_ratio(); 5372 return 0; 5373 } 5374 module_init(init_per_zone_wmark_min) 5375 5376 /* 5377 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 5378 * that we can call two helper functions whenever min_free_kbytes 5379 * changes. 5380 */ 5381 int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 5382 void __user *buffer, size_t *length, loff_t *ppos) 5383 { 5384 proc_dointvec(table, write, buffer, length, ppos); 5385 if (write) 5386 setup_per_zone_wmarks(); 5387 return 0; 5388 } 5389 5390 #ifdef CONFIG_NUMA 5391 int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write, 5392 void __user *buffer, size_t *length, loff_t *ppos) 5393 { 5394 struct zone *zone; 5395 int rc; 5396 5397 rc = proc_dointvec_minmax(table, write, buffer, length, ppos); 5398 if (rc) 5399 return rc; 5400 5401 for_each_zone(zone) 5402 zone->min_unmapped_pages = (zone->present_pages * 5403 sysctl_min_unmapped_ratio) / 100; 5404 return 0; 5405 } 5406 5407 int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write, 5408 void __user *buffer, size_t *length, loff_t *ppos) 5409 { 5410 struct zone *zone; 5411 int rc; 5412 5413 rc = proc_dointvec_minmax(table, write, buffer, length, ppos); 5414 if (rc) 5415 return rc; 5416 5417 for_each_zone(zone) 5418 zone->min_slab_pages = (zone->present_pages * 5419 sysctl_min_slab_ratio) / 100; 5420 return 0; 5421 } 5422 #endif 5423 5424 /* 5425 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 5426 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 5427 * whenever sysctl_lowmem_reserve_ratio changes. 5428 * 5429 * The reserve ratio obviously has absolutely no relation with the 5430 * minimum watermarks. The lowmem reserve ratio can only make sense 5431 * if in function of the boot time zone sizes. 5432 */ 5433 int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write, 5434 void __user *buffer, size_t *length, loff_t *ppos) 5435 { 5436 proc_dointvec_minmax(table, write, buffer, length, ppos); 5437 setup_per_zone_lowmem_reserve(); 5438 return 0; 5439 } 5440 5441 /* 5442 * percpu_pagelist_fraction - changes the pcp->high for each zone on each 5443 * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist 5444 * can have before it gets flushed back to buddy allocator. 5445 */ 5446 5447 int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write, 5448 void __user *buffer, size_t *length, loff_t *ppos) 5449 { 5450 struct zone *zone; 5451 unsigned int cpu; 5452 int ret; 5453 5454 ret = proc_dointvec_minmax(table, write, buffer, length, ppos); 5455 if (!write || (ret < 0)) 5456 return ret; 5457 for_each_populated_zone(zone) { 5458 for_each_possible_cpu(cpu) { 5459 unsigned long high; 5460 high = zone->present_pages / percpu_pagelist_fraction; 5461 setup_pagelist_highmark( 5462 per_cpu_ptr(zone->pageset, cpu), high); 5463 } 5464 } 5465 return 0; 5466 } 5467 5468 int hashdist = HASHDIST_DEFAULT; 5469 5470 #ifdef CONFIG_NUMA 5471 static int __init set_hashdist(char *str) 5472 { 5473 if (!str) 5474 return 0; 5475 hashdist = simple_strtoul(str, &str, 0); 5476 return 1; 5477 } 5478 __setup("hashdist=", set_hashdist); 5479 #endif 5480 5481 /* 5482 * allocate a large system hash table from bootmem 5483 * - it is assumed that the hash table must contain an exact power-of-2 5484 * quantity of entries 5485 * - limit is the number of hash buckets, not the total allocation size 5486 */ 5487 void *__init alloc_large_system_hash(const char *tablename, 5488 unsigned long bucketsize, 5489 unsigned long numentries, 5490 int scale, 5491 int flags, 5492 unsigned int *_hash_shift, 5493 unsigned int *_hash_mask, 5494 unsigned long low_limit, 5495 unsigned long high_limit) 5496 { 5497 unsigned long long max = high_limit; 5498 unsigned long log2qty, size; 5499 void *table = NULL; 5500 5501 /* allow the kernel cmdline to have a say */ 5502 if (!numentries) { 5503 /* round applicable memory size up to nearest megabyte */ 5504 numentries = nr_kernel_pages; 5505 numentries += (1UL << (20 - PAGE_SHIFT)) - 1; 5506 numentries >>= 20 - PAGE_SHIFT; 5507 numentries <<= 20 - PAGE_SHIFT; 5508 5509 /* limit to 1 bucket per 2^scale bytes of low memory */ 5510 if (scale > PAGE_SHIFT) 5511 numentries >>= (scale - PAGE_SHIFT); 5512 else 5513 numentries <<= (PAGE_SHIFT - scale); 5514 5515 /* Make sure we've got at least a 0-order allocation.. */ 5516 if (unlikely(flags & HASH_SMALL)) { 5517 /* Makes no sense without HASH_EARLY */ 5518 WARN_ON(!(flags & HASH_EARLY)); 5519 if (!(numentries >> *_hash_shift)) { 5520 numentries = 1UL << *_hash_shift; 5521 BUG_ON(!numentries); 5522 } 5523 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE)) 5524 numentries = PAGE_SIZE / bucketsize; 5525 } 5526 numentries = roundup_pow_of_two(numentries); 5527 5528 /* limit allocation size to 1/16 total memory by default */ 5529 if (max == 0) { 5530 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 5531 do_div(max, bucketsize); 5532 } 5533 max = min(max, 0x80000000ULL); 5534 5535 if (numentries < low_limit) 5536 numentries = low_limit; 5537 if (numentries > max) 5538 numentries = max; 5539 5540 log2qty = ilog2(numentries); 5541 5542 do { 5543 size = bucketsize << log2qty; 5544 if (flags & HASH_EARLY) 5545 table = alloc_bootmem_nopanic(size); 5546 else if (hashdist) 5547 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 5548 else { 5549 /* 5550 * If bucketsize is not a power-of-two, we may free 5551 * some pages at the end of hash table which 5552 * alloc_pages_exact() automatically does 5553 */ 5554 if (get_order(size) < MAX_ORDER) { 5555 table = alloc_pages_exact(size, GFP_ATOMIC); 5556 kmemleak_alloc(table, size, 1, GFP_ATOMIC); 5557 } 5558 } 5559 } while (!table && size > PAGE_SIZE && --log2qty); 5560 5561 if (!table) 5562 panic("Failed to allocate %s hash table\n", tablename); 5563 5564 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n", 5565 tablename, 5566 (1UL << log2qty), 5567 ilog2(size) - PAGE_SHIFT, 5568 size); 5569 5570 if (_hash_shift) 5571 *_hash_shift = log2qty; 5572 if (_hash_mask) 5573 *_hash_mask = (1 << log2qty) - 1; 5574 5575 return table; 5576 } 5577 5578 /* Return a pointer to the bitmap storing bits affecting a block of pages */ 5579 static inline unsigned long *get_pageblock_bitmap(struct zone *zone, 5580 unsigned long pfn) 5581 { 5582 #ifdef CONFIG_SPARSEMEM 5583 return __pfn_to_section(pfn)->pageblock_flags; 5584 #else 5585 return zone->pageblock_flags; 5586 #endif /* CONFIG_SPARSEMEM */ 5587 } 5588 5589 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) 5590 { 5591 #ifdef CONFIG_SPARSEMEM 5592 pfn &= (PAGES_PER_SECTION-1); 5593 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 5594 #else 5595 pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages); 5596 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 5597 #endif /* CONFIG_SPARSEMEM */ 5598 } 5599 5600 /** 5601 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages 5602 * @page: The page within the block of interest 5603 * @start_bitidx: The first bit of interest to retrieve 5604 * @end_bitidx: The last bit of interest 5605 * returns pageblock_bits flags 5606 */ 5607 unsigned long get_pageblock_flags_group(struct page *page, 5608 int start_bitidx, int end_bitidx) 5609 { 5610 struct zone *zone; 5611 unsigned long *bitmap; 5612 unsigned long pfn, bitidx; 5613 unsigned long flags = 0; 5614 unsigned long value = 1; 5615 5616 zone = page_zone(page); 5617 pfn = page_to_pfn(page); 5618 bitmap = get_pageblock_bitmap(zone, pfn); 5619 bitidx = pfn_to_bitidx(zone, pfn); 5620 5621 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 5622 if (test_bit(bitidx + start_bitidx, bitmap)) 5623 flags |= value; 5624 5625 return flags; 5626 } 5627 5628 /** 5629 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages 5630 * @page: The page within the block of interest 5631 * @start_bitidx: The first bit of interest 5632 * @end_bitidx: The last bit of interest 5633 * @flags: The flags to set 5634 */ 5635 void set_pageblock_flags_group(struct page *page, unsigned long flags, 5636 int start_bitidx, int end_bitidx) 5637 { 5638 struct zone *zone; 5639 unsigned long *bitmap; 5640 unsigned long pfn, bitidx; 5641 unsigned long value = 1; 5642 5643 zone = page_zone(page); 5644 pfn = page_to_pfn(page); 5645 bitmap = get_pageblock_bitmap(zone, pfn); 5646 bitidx = pfn_to_bitidx(zone, pfn); 5647 VM_BUG_ON(pfn < zone->zone_start_pfn); 5648 VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages); 5649 5650 for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) 5651 if (flags & value) 5652 __set_bit(bitidx + start_bitidx, bitmap); 5653 else 5654 __clear_bit(bitidx + start_bitidx, bitmap); 5655 } 5656 5657 /* 5658 * This function checks whether pageblock includes unmovable pages or not. 5659 * If @count is not zero, it is okay to include less @count unmovable pages 5660 * 5661 * PageLRU check wihtout isolation or lru_lock could race so that 5662 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't 5663 * expect this function should be exact. 5664 */ 5665 bool has_unmovable_pages(struct zone *zone, struct page *page, int count, 5666 bool skip_hwpoisoned_pages) 5667 { 5668 unsigned long pfn, iter, found; 5669 int mt; 5670 5671 /* 5672 * For avoiding noise data, lru_add_drain_all() should be called 5673 * If ZONE_MOVABLE, the zone never contains unmovable pages 5674 */ 5675 if (zone_idx(zone) == ZONE_MOVABLE) 5676 return false; 5677 mt = get_pageblock_migratetype(page); 5678 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt)) 5679 return false; 5680 5681 pfn = page_to_pfn(page); 5682 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) { 5683 unsigned long check = pfn + iter; 5684 5685 if (!pfn_valid_within(check)) 5686 continue; 5687 5688 page = pfn_to_page(check); 5689 /* 5690 * We can't use page_count without pin a page 5691 * because another CPU can free compound page. 5692 * This check already skips compound tails of THP 5693 * because their page->_count is zero at all time. 5694 */ 5695 if (!atomic_read(&page->_count)) { 5696 if (PageBuddy(page)) 5697 iter += (1 << page_order(page)) - 1; 5698 continue; 5699 } 5700 5701 /* 5702 * The HWPoisoned page may be not in buddy system, and 5703 * page_count() is not 0. 5704 */ 5705 if (skip_hwpoisoned_pages && PageHWPoison(page)) 5706 continue; 5707 5708 if (!PageLRU(page)) 5709 found++; 5710 /* 5711 * If there are RECLAIMABLE pages, we need to check it. 5712 * But now, memory offline itself doesn't call shrink_slab() 5713 * and it still to be fixed. 5714 */ 5715 /* 5716 * If the page is not RAM, page_count()should be 0. 5717 * we don't need more check. This is an _used_ not-movable page. 5718 * 5719 * The problematic thing here is PG_reserved pages. PG_reserved 5720 * is set to both of a memory hole page and a _used_ kernel 5721 * page at boot. 5722 */ 5723 if (found > count) 5724 return true; 5725 } 5726 return false; 5727 } 5728 5729 bool is_pageblock_removable_nolock(struct page *page) 5730 { 5731 struct zone *zone; 5732 unsigned long pfn; 5733 5734 /* 5735 * We have to be careful here because we are iterating over memory 5736 * sections which are not zone aware so we might end up outside of 5737 * the zone but still within the section. 5738 * We have to take care about the node as well. If the node is offline 5739 * its NODE_DATA will be NULL - see page_zone. 5740 */ 5741 if (!node_online(page_to_nid(page))) 5742 return false; 5743 5744 zone = page_zone(page); 5745 pfn = page_to_pfn(page); 5746 if (zone->zone_start_pfn > pfn || 5747 zone->zone_start_pfn + zone->spanned_pages <= pfn) 5748 return false; 5749 5750 return !has_unmovable_pages(zone, page, 0, true); 5751 } 5752 5753 #ifdef CONFIG_CMA 5754 5755 static unsigned long pfn_max_align_down(unsigned long pfn) 5756 { 5757 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES, 5758 pageblock_nr_pages) - 1); 5759 } 5760 5761 static unsigned long pfn_max_align_up(unsigned long pfn) 5762 { 5763 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES, 5764 pageblock_nr_pages)); 5765 } 5766 5767 /* [start, end) must belong to a single zone. */ 5768 static int __alloc_contig_migrate_range(struct compact_control *cc, 5769 unsigned long start, unsigned long end) 5770 { 5771 /* This function is based on compact_zone() from compaction.c. */ 5772 unsigned long nr_reclaimed; 5773 unsigned long pfn = start; 5774 unsigned int tries = 0; 5775 int ret = 0; 5776 5777 migrate_prep(); 5778 5779 while (pfn < end || !list_empty(&cc->migratepages)) { 5780 if (fatal_signal_pending(current)) { 5781 ret = -EINTR; 5782 break; 5783 } 5784 5785 if (list_empty(&cc->migratepages)) { 5786 cc->nr_migratepages = 0; 5787 pfn = isolate_migratepages_range(cc->zone, cc, 5788 pfn, end, true); 5789 if (!pfn) { 5790 ret = -EINTR; 5791 break; 5792 } 5793 tries = 0; 5794 } else if (++tries == 5) { 5795 ret = ret < 0 ? ret : -EBUSY; 5796 break; 5797 } 5798 5799 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone, 5800 &cc->migratepages); 5801 cc->nr_migratepages -= nr_reclaimed; 5802 5803 ret = migrate_pages(&cc->migratepages, 5804 alloc_migrate_target, 5805 0, false, MIGRATE_SYNC, 5806 MR_CMA); 5807 } 5808 5809 putback_movable_pages(&cc->migratepages); 5810 return ret > 0 ? 0 : ret; 5811 } 5812 5813 /** 5814 * alloc_contig_range() -- tries to allocate given range of pages 5815 * @start: start PFN to allocate 5816 * @end: one-past-the-last PFN to allocate 5817 * @migratetype: migratetype of the underlaying pageblocks (either 5818 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks 5819 * in range must have the same migratetype and it must 5820 * be either of the two. 5821 * 5822 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES 5823 * aligned, however it's the caller's responsibility to guarantee that 5824 * we are the only thread that changes migrate type of pageblocks the 5825 * pages fall in. 5826 * 5827 * The PFN range must belong to a single zone. 5828 * 5829 * Returns zero on success or negative error code. On success all 5830 * pages which PFN is in [start, end) are allocated for the caller and 5831 * need to be freed with free_contig_range(). 5832 */ 5833 int alloc_contig_range(unsigned long start, unsigned long end, 5834 unsigned migratetype) 5835 { 5836 unsigned long outer_start, outer_end; 5837 int ret = 0, order; 5838 5839 struct compact_control cc = { 5840 .nr_migratepages = 0, 5841 .order = -1, 5842 .zone = page_zone(pfn_to_page(start)), 5843 .sync = true, 5844 .ignore_skip_hint = true, 5845 }; 5846 INIT_LIST_HEAD(&cc.migratepages); 5847 5848 /* 5849 * What we do here is we mark all pageblocks in range as 5850 * MIGRATE_ISOLATE. Because pageblock and max order pages may 5851 * have different sizes, and due to the way page allocator 5852 * work, we align the range to biggest of the two pages so 5853 * that page allocator won't try to merge buddies from 5854 * different pageblocks and change MIGRATE_ISOLATE to some 5855 * other migration type. 5856 * 5857 * Once the pageblocks are marked as MIGRATE_ISOLATE, we 5858 * migrate the pages from an unaligned range (ie. pages that 5859 * we are interested in). This will put all the pages in 5860 * range back to page allocator as MIGRATE_ISOLATE. 5861 * 5862 * When this is done, we take the pages in range from page 5863 * allocator removing them from the buddy system. This way 5864 * page allocator will never consider using them. 5865 * 5866 * This lets us mark the pageblocks back as 5867 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the 5868 * aligned range but not in the unaligned, original range are 5869 * put back to page allocator so that buddy can use them. 5870 */ 5871 5872 ret = start_isolate_page_range(pfn_max_align_down(start), 5873 pfn_max_align_up(end), migratetype, 5874 false); 5875 if (ret) 5876 return ret; 5877 5878 ret = __alloc_contig_migrate_range(&cc, start, end); 5879 if (ret) 5880 goto done; 5881 5882 /* 5883 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES 5884 * aligned blocks that are marked as MIGRATE_ISOLATE. What's 5885 * more, all pages in [start, end) are free in page allocator. 5886 * What we are going to do is to allocate all pages from 5887 * [start, end) (that is remove them from page allocator). 5888 * 5889 * The only problem is that pages at the beginning and at the 5890 * end of interesting range may be not aligned with pages that 5891 * page allocator holds, ie. they can be part of higher order 5892 * pages. Because of this, we reserve the bigger range and 5893 * once this is done free the pages we are not interested in. 5894 * 5895 * We don't have to hold zone->lock here because the pages are 5896 * isolated thus they won't get removed from buddy. 5897 */ 5898 5899 lru_add_drain_all(); 5900 drain_all_pages(); 5901 5902 order = 0; 5903 outer_start = start; 5904 while (!PageBuddy(pfn_to_page(outer_start))) { 5905 if (++order >= MAX_ORDER) { 5906 ret = -EBUSY; 5907 goto done; 5908 } 5909 outer_start &= ~0UL << order; 5910 } 5911 5912 /* Make sure the range is really isolated. */ 5913 if (test_pages_isolated(outer_start, end, false)) { 5914 pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n", 5915 outer_start, end); 5916 ret = -EBUSY; 5917 goto done; 5918 } 5919 5920 5921 /* Grab isolated pages from freelists. */ 5922 outer_end = isolate_freepages_range(&cc, outer_start, end); 5923 if (!outer_end) { 5924 ret = -EBUSY; 5925 goto done; 5926 } 5927 5928 /* Free head and tail (if any) */ 5929 if (start != outer_start) 5930 free_contig_range(outer_start, start - outer_start); 5931 if (end != outer_end) 5932 free_contig_range(end, outer_end - end); 5933 5934 done: 5935 undo_isolate_page_range(pfn_max_align_down(start), 5936 pfn_max_align_up(end), migratetype); 5937 return ret; 5938 } 5939 5940 void free_contig_range(unsigned long pfn, unsigned nr_pages) 5941 { 5942 unsigned int count = 0; 5943 5944 for (; nr_pages--; pfn++) { 5945 struct page *page = pfn_to_page(pfn); 5946 5947 count += page_count(page) != 1; 5948 __free_page(page); 5949 } 5950 WARN(count != 0, "%d pages are still in use!\n", count); 5951 } 5952 #endif 5953 5954 #ifdef CONFIG_MEMORY_HOTPLUG 5955 static int __meminit __zone_pcp_update(void *data) 5956 { 5957 struct zone *zone = data; 5958 int cpu; 5959 unsigned long batch = zone_batchsize(zone), flags; 5960 5961 for_each_possible_cpu(cpu) { 5962 struct per_cpu_pageset *pset; 5963 struct per_cpu_pages *pcp; 5964 5965 pset = per_cpu_ptr(zone->pageset, cpu); 5966 pcp = &pset->pcp; 5967 5968 local_irq_save(flags); 5969 if (pcp->count > 0) 5970 free_pcppages_bulk(zone, pcp->count, pcp); 5971 drain_zonestat(zone, pset); 5972 setup_pageset(pset, batch); 5973 local_irq_restore(flags); 5974 } 5975 return 0; 5976 } 5977 5978 void __meminit zone_pcp_update(struct zone *zone) 5979 { 5980 stop_machine(__zone_pcp_update, zone, NULL); 5981 } 5982 #endif 5983 5984 void zone_pcp_reset(struct zone *zone) 5985 { 5986 unsigned long flags; 5987 int cpu; 5988 struct per_cpu_pageset *pset; 5989 5990 /* avoid races with drain_pages() */ 5991 local_irq_save(flags); 5992 if (zone->pageset != &boot_pageset) { 5993 for_each_online_cpu(cpu) { 5994 pset = per_cpu_ptr(zone->pageset, cpu); 5995 drain_zonestat(zone, pset); 5996 } 5997 free_percpu(zone->pageset); 5998 zone->pageset = &boot_pageset; 5999 } 6000 local_irq_restore(flags); 6001 } 6002 6003 #ifdef CONFIG_MEMORY_HOTREMOVE 6004 /* 6005 * All pages in the range must be isolated before calling this. 6006 */ 6007 void 6008 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) 6009 { 6010 struct page *page; 6011 struct zone *zone; 6012 int order, i; 6013 unsigned long pfn; 6014 unsigned long flags; 6015 /* find the first valid pfn */ 6016 for (pfn = start_pfn; pfn < end_pfn; pfn++) 6017 if (pfn_valid(pfn)) 6018 break; 6019 if (pfn == end_pfn) 6020 return; 6021 zone = page_zone(pfn_to_page(pfn)); 6022 spin_lock_irqsave(&zone->lock, flags); 6023 pfn = start_pfn; 6024 while (pfn < end_pfn) { 6025 if (!pfn_valid(pfn)) { 6026 pfn++; 6027 continue; 6028 } 6029 page = pfn_to_page(pfn); 6030 /* 6031 * The HWPoisoned page may be not in buddy system, and 6032 * page_count() is not 0. 6033 */ 6034 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) { 6035 pfn++; 6036 SetPageReserved(page); 6037 continue; 6038 } 6039 6040 BUG_ON(page_count(page)); 6041 BUG_ON(!PageBuddy(page)); 6042 order = page_order(page); 6043 #ifdef CONFIG_DEBUG_VM 6044 printk(KERN_INFO "remove from free list %lx %d %lx\n", 6045 pfn, 1 << order, end_pfn); 6046 #endif 6047 list_del(&page->lru); 6048 rmv_page_order(page); 6049 zone->free_area[order].nr_free--; 6050 for (i = 0; i < (1 << order); i++) 6051 SetPageReserved((page+i)); 6052 pfn += (1 << order); 6053 } 6054 spin_unlock_irqrestore(&zone->lock, flags); 6055 } 6056 #endif 6057 6058 #ifdef CONFIG_MEMORY_FAILURE 6059 bool is_free_buddy_page(struct page *page) 6060 { 6061 struct zone *zone = page_zone(page); 6062 unsigned long pfn = page_to_pfn(page); 6063 unsigned long flags; 6064 int order; 6065 6066 spin_lock_irqsave(&zone->lock, flags); 6067 for (order = 0; order < MAX_ORDER; order++) { 6068 struct page *page_head = page - (pfn & ((1 << order) - 1)); 6069 6070 if (PageBuddy(page_head) && page_order(page_head) >= order) 6071 break; 6072 } 6073 spin_unlock_irqrestore(&zone->lock, flags); 6074 6075 return order < MAX_ORDER; 6076 } 6077 #endif 6078 6079 static const struct trace_print_flags pageflag_names[] = { 6080 {1UL << PG_locked, "locked" }, 6081 {1UL << PG_error, "error" }, 6082 {1UL << PG_referenced, "referenced" }, 6083 {1UL << PG_uptodate, "uptodate" }, 6084 {1UL << PG_dirty, "dirty" }, 6085 {1UL << PG_lru, "lru" }, 6086 {1UL << PG_active, "active" }, 6087 {1UL << PG_slab, "slab" }, 6088 {1UL << PG_owner_priv_1, "owner_priv_1" }, 6089 {1UL << PG_arch_1, "arch_1" }, 6090 {1UL << PG_reserved, "reserved" }, 6091 {1UL << PG_private, "private" }, 6092 {1UL << PG_private_2, "private_2" }, 6093 {1UL << PG_writeback, "writeback" }, 6094 #ifdef CONFIG_PAGEFLAGS_EXTENDED 6095 {1UL << PG_head, "head" }, 6096 {1UL << PG_tail, "tail" }, 6097 #else 6098 {1UL << PG_compound, "compound" }, 6099 #endif 6100 {1UL << PG_swapcache, "swapcache" }, 6101 {1UL << PG_mappedtodisk, "mappedtodisk" }, 6102 {1UL << PG_reclaim, "reclaim" }, 6103 {1UL << PG_swapbacked, "swapbacked" }, 6104 {1UL << PG_unevictable, "unevictable" }, 6105 #ifdef CONFIG_MMU 6106 {1UL << PG_mlocked, "mlocked" }, 6107 #endif 6108 #ifdef CONFIG_ARCH_USES_PG_UNCACHED 6109 {1UL << PG_uncached, "uncached" }, 6110 #endif 6111 #ifdef CONFIG_MEMORY_FAILURE 6112 {1UL << PG_hwpoison, "hwpoison" }, 6113 #endif 6114 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 6115 {1UL << PG_compound_lock, "compound_lock" }, 6116 #endif 6117 }; 6118 6119 static void dump_page_flags(unsigned long flags) 6120 { 6121 const char *delim = ""; 6122 unsigned long mask; 6123 int i; 6124 6125 BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS); 6126 6127 printk(KERN_ALERT "page flags: %#lx(", flags); 6128 6129 /* remove zone id */ 6130 flags &= (1UL << NR_PAGEFLAGS) - 1; 6131 6132 for (i = 0; i < ARRAY_SIZE(pageflag_names) && flags; i++) { 6133 6134 mask = pageflag_names[i].mask; 6135 if ((flags & mask) != mask) 6136 continue; 6137 6138 flags &= ~mask; 6139 printk("%s%s", delim, pageflag_names[i].name); 6140 delim = "|"; 6141 } 6142 6143 /* check for left over flags */ 6144 if (flags) 6145 printk("%s%#lx", delim, flags); 6146 6147 printk(")\n"); 6148 } 6149 6150 void dump_page(struct page *page) 6151 { 6152 printk(KERN_ALERT 6153 "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n", 6154 page, atomic_read(&page->_count), page_mapcount(page), 6155 page->mapping, page->index); 6156 dump_page_flags(page->flags); 6157 mem_cgroup_print_bad_page(page); 6158 } 6159