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/kasan.h> 29 #include <linux/module.h> 30 #include <linux/suspend.h> 31 #include <linux/pagevec.h> 32 #include <linux/blkdev.h> 33 #include <linux/slab.h> 34 #include <linux/ratelimit.h> 35 #include <linux/oom.h> 36 #include <linux/notifier.h> 37 #include <linux/topology.h> 38 #include <linux/sysctl.h> 39 #include <linux/cpu.h> 40 #include <linux/cpuset.h> 41 #include <linux/memory_hotplug.h> 42 #include <linux/nodemask.h> 43 #include <linux/vmalloc.h> 44 #include <linux/vmstat.h> 45 #include <linux/mempolicy.h> 46 #include <linux/stop_machine.h> 47 #include <linux/sort.h> 48 #include <linux/pfn.h> 49 #include <linux/backing-dev.h> 50 #include <linux/fault-inject.h> 51 #include <linux/page-isolation.h> 52 #include <linux/page_ext.h> 53 #include <linux/debugobjects.h> 54 #include <linux/kmemleak.h> 55 #include <linux/compaction.h> 56 #include <trace/events/kmem.h> 57 #include <linux/prefetch.h> 58 #include <linux/mm_inline.h> 59 #include <linux/migrate.h> 60 #include <linux/page_ext.h> 61 #include <linux/hugetlb.h> 62 #include <linux/sched/rt.h> 63 #include <linux/page_owner.h> 64 #include <linux/kthread.h> 65 66 #include <asm/sections.h> 67 #include <asm/tlbflush.h> 68 #include <asm/div64.h> 69 #include "internal.h" 70 71 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */ 72 static DEFINE_MUTEX(pcp_batch_high_lock); 73 #define MIN_PERCPU_PAGELIST_FRACTION (8) 74 75 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID 76 DEFINE_PER_CPU(int, numa_node); 77 EXPORT_PER_CPU_SYMBOL(numa_node); 78 #endif 79 80 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 81 /* 82 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly. 83 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined. 84 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem() 85 * defined in <linux/topology.h>. 86 */ 87 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */ 88 EXPORT_PER_CPU_SYMBOL(_numa_mem_); 89 int _node_numa_mem_[MAX_NUMNODES]; 90 #endif 91 92 /* 93 * Array of node states. 94 */ 95 nodemask_t node_states[NR_NODE_STATES] __read_mostly = { 96 [N_POSSIBLE] = NODE_MASK_ALL, 97 [N_ONLINE] = { { [0] = 1UL } }, 98 #ifndef CONFIG_NUMA 99 [N_NORMAL_MEMORY] = { { [0] = 1UL } }, 100 #ifdef CONFIG_HIGHMEM 101 [N_HIGH_MEMORY] = { { [0] = 1UL } }, 102 #endif 103 #ifdef CONFIG_MOVABLE_NODE 104 [N_MEMORY] = { { [0] = 1UL } }, 105 #endif 106 [N_CPU] = { { [0] = 1UL } }, 107 #endif /* NUMA */ 108 }; 109 EXPORT_SYMBOL(node_states); 110 111 /* Protect totalram_pages and zone->managed_pages */ 112 static DEFINE_SPINLOCK(managed_page_count_lock); 113 114 unsigned long totalram_pages __read_mostly; 115 unsigned long totalreserve_pages __read_mostly; 116 unsigned long totalcma_pages __read_mostly; 117 /* 118 * When calculating the number of globally allowed dirty pages, there 119 * is a certain number of per-zone reserves that should not be 120 * considered dirtyable memory. This is the sum of those reserves 121 * over all existing zones that contribute dirtyable memory. 122 */ 123 unsigned long dirty_balance_reserve __read_mostly; 124 125 int percpu_pagelist_fraction; 126 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; 127 128 #ifdef CONFIG_PM_SLEEP 129 /* 130 * The following functions are used by the suspend/hibernate code to temporarily 131 * change gfp_allowed_mask in order to avoid using I/O during memory allocations 132 * while devices are suspended. To avoid races with the suspend/hibernate code, 133 * they should always be called with pm_mutex held (gfp_allowed_mask also should 134 * only be modified with pm_mutex held, unless the suspend/hibernate code is 135 * guaranteed not to run in parallel with that modification). 136 */ 137 138 static gfp_t saved_gfp_mask; 139 140 void pm_restore_gfp_mask(void) 141 { 142 WARN_ON(!mutex_is_locked(&pm_mutex)); 143 if (saved_gfp_mask) { 144 gfp_allowed_mask = saved_gfp_mask; 145 saved_gfp_mask = 0; 146 } 147 } 148 149 void pm_restrict_gfp_mask(void) 150 { 151 WARN_ON(!mutex_is_locked(&pm_mutex)); 152 WARN_ON(saved_gfp_mask); 153 saved_gfp_mask = gfp_allowed_mask; 154 gfp_allowed_mask &= ~GFP_IOFS; 155 } 156 157 bool pm_suspended_storage(void) 158 { 159 if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS) 160 return false; 161 return true; 162 } 163 #endif /* CONFIG_PM_SLEEP */ 164 165 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 166 int pageblock_order __read_mostly; 167 #endif 168 169 static void __free_pages_ok(struct page *page, unsigned int order); 170 171 /* 172 * results with 256, 32 in the lowmem_reserve sysctl: 173 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) 174 * 1G machine -> (16M dma, 784M normal, 224M high) 175 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA 176 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL 177 * HIGHMEM allocation will leave (224M+784M)/256 of ram reserved in ZONE_DMA 178 * 179 * TBD: should special case ZONE_DMA32 machines here - in those we normally 180 * don't need any ZONE_NORMAL reservation 181 */ 182 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 183 #ifdef CONFIG_ZONE_DMA 184 256, 185 #endif 186 #ifdef CONFIG_ZONE_DMA32 187 256, 188 #endif 189 #ifdef CONFIG_HIGHMEM 190 32, 191 #endif 192 32, 193 }; 194 195 EXPORT_SYMBOL(totalram_pages); 196 197 static char * const zone_names[MAX_NR_ZONES] = { 198 #ifdef CONFIG_ZONE_DMA 199 "DMA", 200 #endif 201 #ifdef CONFIG_ZONE_DMA32 202 "DMA32", 203 #endif 204 "Normal", 205 #ifdef CONFIG_HIGHMEM 206 "HighMem", 207 #endif 208 "Movable", 209 }; 210 211 int min_free_kbytes = 1024; 212 int user_min_free_kbytes = -1; 213 214 static unsigned long __meminitdata nr_kernel_pages; 215 static unsigned long __meminitdata nr_all_pages; 216 static unsigned long __meminitdata dma_reserve; 217 218 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 219 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; 220 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; 221 static unsigned long __initdata required_kernelcore; 222 static unsigned long __initdata required_movablecore; 223 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES]; 224 225 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ 226 int movable_zone; 227 EXPORT_SYMBOL(movable_zone); 228 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 229 230 #if MAX_NUMNODES > 1 231 int nr_node_ids __read_mostly = MAX_NUMNODES; 232 int nr_online_nodes __read_mostly = 1; 233 EXPORT_SYMBOL(nr_node_ids); 234 EXPORT_SYMBOL(nr_online_nodes); 235 #endif 236 237 int page_group_by_mobility_disabled __read_mostly; 238 239 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 240 static inline void reset_deferred_meminit(pg_data_t *pgdat) 241 { 242 pgdat->first_deferred_pfn = ULONG_MAX; 243 } 244 245 /* Returns true if the struct page for the pfn is uninitialised */ 246 static inline bool __meminit early_page_uninitialised(unsigned long pfn) 247 { 248 if (pfn >= NODE_DATA(early_pfn_to_nid(pfn))->first_deferred_pfn) 249 return true; 250 251 return false; 252 } 253 254 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid) 255 { 256 if (pfn >= NODE_DATA(nid)->first_deferred_pfn) 257 return true; 258 259 return false; 260 } 261 262 /* 263 * Returns false when the remaining initialisation should be deferred until 264 * later in the boot cycle when it can be parallelised. 265 */ 266 static inline bool update_defer_init(pg_data_t *pgdat, 267 unsigned long pfn, unsigned long zone_end, 268 unsigned long *nr_initialised) 269 { 270 /* Always populate low zones for address-contrained allocations */ 271 if (zone_end < pgdat_end_pfn(pgdat)) 272 return true; 273 274 /* Initialise at least 2G of the highest zone */ 275 (*nr_initialised)++; 276 if (*nr_initialised > (2UL << (30 - PAGE_SHIFT)) && 277 (pfn & (PAGES_PER_SECTION - 1)) == 0) { 278 pgdat->first_deferred_pfn = pfn; 279 return false; 280 } 281 282 return true; 283 } 284 #else 285 static inline void reset_deferred_meminit(pg_data_t *pgdat) 286 { 287 } 288 289 static inline bool early_page_uninitialised(unsigned long pfn) 290 { 291 return false; 292 } 293 294 static inline bool early_page_nid_uninitialised(unsigned long pfn, int nid) 295 { 296 return false; 297 } 298 299 static inline bool update_defer_init(pg_data_t *pgdat, 300 unsigned long pfn, unsigned long zone_end, 301 unsigned long *nr_initialised) 302 { 303 return true; 304 } 305 #endif 306 307 308 void set_pageblock_migratetype(struct page *page, int migratetype) 309 { 310 if (unlikely(page_group_by_mobility_disabled && 311 migratetype < MIGRATE_PCPTYPES)) 312 migratetype = MIGRATE_UNMOVABLE; 313 314 set_pageblock_flags_group(page, (unsigned long)migratetype, 315 PB_migrate, PB_migrate_end); 316 } 317 318 #ifdef CONFIG_DEBUG_VM 319 static int page_outside_zone_boundaries(struct zone *zone, struct page *page) 320 { 321 int ret = 0; 322 unsigned seq; 323 unsigned long pfn = page_to_pfn(page); 324 unsigned long sp, start_pfn; 325 326 do { 327 seq = zone_span_seqbegin(zone); 328 start_pfn = zone->zone_start_pfn; 329 sp = zone->spanned_pages; 330 if (!zone_spans_pfn(zone, pfn)) 331 ret = 1; 332 } while (zone_span_seqretry(zone, seq)); 333 334 if (ret) 335 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n", 336 pfn, zone_to_nid(zone), zone->name, 337 start_pfn, start_pfn + sp); 338 339 return ret; 340 } 341 342 static int page_is_consistent(struct zone *zone, struct page *page) 343 { 344 if (!pfn_valid_within(page_to_pfn(page))) 345 return 0; 346 if (zone != page_zone(page)) 347 return 0; 348 349 return 1; 350 } 351 /* 352 * Temporary debugging check for pages not lying within a given zone. 353 */ 354 static int bad_range(struct zone *zone, struct page *page) 355 { 356 if (page_outside_zone_boundaries(zone, page)) 357 return 1; 358 if (!page_is_consistent(zone, page)) 359 return 1; 360 361 return 0; 362 } 363 #else 364 static inline int bad_range(struct zone *zone, struct page *page) 365 { 366 return 0; 367 } 368 #endif 369 370 static void bad_page(struct page *page, const char *reason, 371 unsigned long bad_flags) 372 { 373 static unsigned long resume; 374 static unsigned long nr_shown; 375 static unsigned long nr_unshown; 376 377 /* Don't complain about poisoned pages */ 378 if (PageHWPoison(page)) { 379 page_mapcount_reset(page); /* remove PageBuddy */ 380 return; 381 } 382 383 /* 384 * Allow a burst of 60 reports, then keep quiet for that minute; 385 * or allow a steady drip of one report per second. 386 */ 387 if (nr_shown == 60) { 388 if (time_before(jiffies, resume)) { 389 nr_unshown++; 390 goto out; 391 } 392 if (nr_unshown) { 393 printk(KERN_ALERT 394 "BUG: Bad page state: %lu messages suppressed\n", 395 nr_unshown); 396 nr_unshown = 0; 397 } 398 nr_shown = 0; 399 } 400 if (nr_shown++ == 0) 401 resume = jiffies + 60 * HZ; 402 403 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n", 404 current->comm, page_to_pfn(page)); 405 dump_page_badflags(page, reason, bad_flags); 406 407 print_modules(); 408 dump_stack(); 409 out: 410 /* Leave bad fields for debug, except PageBuddy could make trouble */ 411 page_mapcount_reset(page); /* remove PageBuddy */ 412 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); 413 } 414 415 /* 416 * Higher-order pages are called "compound pages". They are structured thusly: 417 * 418 * The first PAGE_SIZE page is called the "head page". 419 * 420 * The remaining PAGE_SIZE pages are called "tail pages". 421 * 422 * All pages have PG_compound set. All tail pages have their ->first_page 423 * pointing at the head page. 424 * 425 * The first tail page's ->lru.next holds the address of the compound page's 426 * put_page() function. Its ->lru.prev holds the order of allocation. 427 * This usage means that zero-order pages may not be compound. 428 */ 429 430 static void free_compound_page(struct page *page) 431 { 432 __free_pages_ok(page, compound_order(page)); 433 } 434 435 void prep_compound_page(struct page *page, unsigned long order) 436 { 437 int i; 438 int nr_pages = 1 << order; 439 440 set_compound_page_dtor(page, free_compound_page); 441 set_compound_order(page, order); 442 __SetPageHead(page); 443 for (i = 1; i < nr_pages; i++) { 444 struct page *p = page + i; 445 set_page_count(p, 0); 446 p->first_page = page; 447 /* Make sure p->first_page is always valid for PageTail() */ 448 smp_wmb(); 449 __SetPageTail(p); 450 } 451 } 452 453 #ifdef CONFIG_DEBUG_PAGEALLOC 454 unsigned int _debug_guardpage_minorder; 455 bool _debug_pagealloc_enabled __read_mostly; 456 bool _debug_guardpage_enabled __read_mostly; 457 458 static int __init early_debug_pagealloc(char *buf) 459 { 460 if (!buf) 461 return -EINVAL; 462 463 if (strcmp(buf, "on") == 0) 464 _debug_pagealloc_enabled = true; 465 466 return 0; 467 } 468 early_param("debug_pagealloc", early_debug_pagealloc); 469 470 static bool need_debug_guardpage(void) 471 { 472 /* If we don't use debug_pagealloc, we don't need guard page */ 473 if (!debug_pagealloc_enabled()) 474 return false; 475 476 return true; 477 } 478 479 static void init_debug_guardpage(void) 480 { 481 if (!debug_pagealloc_enabled()) 482 return; 483 484 _debug_guardpage_enabled = true; 485 } 486 487 struct page_ext_operations debug_guardpage_ops = { 488 .need = need_debug_guardpage, 489 .init = init_debug_guardpage, 490 }; 491 492 static int __init debug_guardpage_minorder_setup(char *buf) 493 { 494 unsigned long res; 495 496 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) { 497 printk(KERN_ERR "Bad debug_guardpage_minorder value\n"); 498 return 0; 499 } 500 _debug_guardpage_minorder = res; 501 printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res); 502 return 0; 503 } 504 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup); 505 506 static inline void set_page_guard(struct zone *zone, struct page *page, 507 unsigned int order, int migratetype) 508 { 509 struct page_ext *page_ext; 510 511 if (!debug_guardpage_enabled()) 512 return; 513 514 page_ext = lookup_page_ext(page); 515 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags); 516 517 INIT_LIST_HEAD(&page->lru); 518 set_page_private(page, order); 519 /* Guard pages are not available for any usage */ 520 __mod_zone_freepage_state(zone, -(1 << order), migratetype); 521 } 522 523 static inline void clear_page_guard(struct zone *zone, struct page *page, 524 unsigned int order, int migratetype) 525 { 526 struct page_ext *page_ext; 527 528 if (!debug_guardpage_enabled()) 529 return; 530 531 page_ext = lookup_page_ext(page); 532 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags); 533 534 set_page_private(page, 0); 535 if (!is_migrate_isolate(migratetype)) 536 __mod_zone_freepage_state(zone, (1 << order), migratetype); 537 } 538 #else 539 struct page_ext_operations debug_guardpage_ops = { NULL, }; 540 static inline void set_page_guard(struct zone *zone, struct page *page, 541 unsigned int order, int migratetype) {} 542 static inline void clear_page_guard(struct zone *zone, struct page *page, 543 unsigned int order, int migratetype) {} 544 #endif 545 546 static inline void set_page_order(struct page *page, unsigned int order) 547 { 548 set_page_private(page, order); 549 __SetPageBuddy(page); 550 } 551 552 static inline void rmv_page_order(struct page *page) 553 { 554 __ClearPageBuddy(page); 555 set_page_private(page, 0); 556 } 557 558 /* 559 * This function checks whether a page is free && is the buddy 560 * we can do coalesce a page and its buddy if 561 * (a) the buddy is not in a hole && 562 * (b) the buddy is in the buddy system && 563 * (c) a page and its buddy have the same order && 564 * (d) a page and its buddy are in the same zone. 565 * 566 * For recording whether a page is in the buddy system, we set ->_mapcount 567 * PAGE_BUDDY_MAPCOUNT_VALUE. 568 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is 569 * serialized by zone->lock. 570 * 571 * For recording page's order, we use page_private(page). 572 */ 573 static inline int page_is_buddy(struct page *page, struct page *buddy, 574 unsigned int order) 575 { 576 if (!pfn_valid_within(page_to_pfn(buddy))) 577 return 0; 578 579 if (page_is_guard(buddy) && page_order(buddy) == order) { 580 if (page_zone_id(page) != page_zone_id(buddy)) 581 return 0; 582 583 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); 584 585 return 1; 586 } 587 588 if (PageBuddy(buddy) && page_order(buddy) == order) { 589 /* 590 * zone check is done late to avoid uselessly 591 * calculating zone/node ids for pages that could 592 * never merge. 593 */ 594 if (page_zone_id(page) != page_zone_id(buddy)) 595 return 0; 596 597 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); 598 599 return 1; 600 } 601 return 0; 602 } 603 604 /* 605 * Freeing function for a buddy system allocator. 606 * 607 * The concept of a buddy system is to maintain direct-mapped table 608 * (containing bit values) for memory blocks of various "orders". 609 * The bottom level table contains the map for the smallest allocatable 610 * units of memory (here, pages), and each level above it describes 611 * pairs of units from the levels below, hence, "buddies". 612 * At a high level, all that happens here is marking the table entry 613 * at the bottom level available, and propagating the changes upward 614 * as necessary, plus some accounting needed to play nicely with other 615 * parts of the VM system. 616 * At each level, we keep a list of pages, which are heads of continuous 617 * free pages of length of (1 << order) and marked with _mapcount 618 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page) 619 * field. 620 * So when we are allocating or freeing one, we can derive the state of the 621 * other. That is, if we allocate a small block, and both were 622 * free, the remainder of the region must be split into blocks. 623 * If a block is freed, and its buddy is also free, then this 624 * triggers coalescing into a block of larger size. 625 * 626 * -- nyc 627 */ 628 629 static inline void __free_one_page(struct page *page, 630 unsigned long pfn, 631 struct zone *zone, unsigned int order, 632 int migratetype) 633 { 634 unsigned long page_idx; 635 unsigned long combined_idx; 636 unsigned long uninitialized_var(buddy_idx); 637 struct page *buddy; 638 int max_order = MAX_ORDER; 639 640 VM_BUG_ON(!zone_is_initialized(zone)); 641 VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page); 642 643 VM_BUG_ON(migratetype == -1); 644 if (is_migrate_isolate(migratetype)) { 645 /* 646 * We restrict max order of merging to prevent merge 647 * between freepages on isolate pageblock and normal 648 * pageblock. Without this, pageblock isolation 649 * could cause incorrect freepage accounting. 650 */ 651 max_order = min(MAX_ORDER, pageblock_order + 1); 652 } else { 653 __mod_zone_freepage_state(zone, 1 << order, migratetype); 654 } 655 656 page_idx = pfn & ((1 << max_order) - 1); 657 658 VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page); 659 VM_BUG_ON_PAGE(bad_range(zone, page), page); 660 661 while (order < max_order - 1) { 662 buddy_idx = __find_buddy_index(page_idx, order); 663 buddy = page + (buddy_idx - page_idx); 664 if (!page_is_buddy(page, buddy, order)) 665 break; 666 /* 667 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page, 668 * merge with it and move up one order. 669 */ 670 if (page_is_guard(buddy)) { 671 clear_page_guard(zone, buddy, order, migratetype); 672 } else { 673 list_del(&buddy->lru); 674 zone->free_area[order].nr_free--; 675 rmv_page_order(buddy); 676 } 677 combined_idx = buddy_idx & page_idx; 678 page = page + (combined_idx - page_idx); 679 page_idx = combined_idx; 680 order++; 681 } 682 set_page_order(page, order); 683 684 /* 685 * If this is not the largest possible page, check if the buddy 686 * of the next-highest order is free. If it is, it's possible 687 * that pages are being freed that will coalesce soon. In case, 688 * that is happening, add the free page to the tail of the list 689 * so it's less likely to be used soon and more likely to be merged 690 * as a higher order page 691 */ 692 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) { 693 struct page *higher_page, *higher_buddy; 694 combined_idx = buddy_idx & page_idx; 695 higher_page = page + (combined_idx - page_idx); 696 buddy_idx = __find_buddy_index(combined_idx, order + 1); 697 higher_buddy = higher_page + (buddy_idx - combined_idx); 698 if (page_is_buddy(higher_page, higher_buddy, order + 1)) { 699 list_add_tail(&page->lru, 700 &zone->free_area[order].free_list[migratetype]); 701 goto out; 702 } 703 } 704 705 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]); 706 out: 707 zone->free_area[order].nr_free++; 708 } 709 710 static inline int free_pages_check(struct page *page) 711 { 712 const char *bad_reason = NULL; 713 unsigned long bad_flags = 0; 714 715 if (unlikely(page_mapcount(page))) 716 bad_reason = "nonzero mapcount"; 717 if (unlikely(page->mapping != NULL)) 718 bad_reason = "non-NULL mapping"; 719 if (unlikely(atomic_read(&page->_count) != 0)) 720 bad_reason = "nonzero _count"; 721 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) { 722 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set"; 723 bad_flags = PAGE_FLAGS_CHECK_AT_FREE; 724 } 725 #ifdef CONFIG_MEMCG 726 if (unlikely(page->mem_cgroup)) 727 bad_reason = "page still charged to cgroup"; 728 #endif 729 if (unlikely(bad_reason)) { 730 bad_page(page, bad_reason, bad_flags); 731 return 1; 732 } 733 page_cpupid_reset_last(page); 734 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP) 735 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; 736 return 0; 737 } 738 739 /* 740 * Frees a number of pages from the PCP lists 741 * Assumes all pages on list are in same zone, and of same order. 742 * count is the number of pages to free. 743 * 744 * If the zone was previously in an "all pages pinned" state then look to 745 * see if this freeing clears that state. 746 * 747 * And clear the zone's pages_scanned counter, to hold off the "all pages are 748 * pinned" detection logic. 749 */ 750 static void free_pcppages_bulk(struct zone *zone, int count, 751 struct per_cpu_pages *pcp) 752 { 753 int migratetype = 0; 754 int batch_free = 0; 755 int to_free = count; 756 unsigned long nr_scanned; 757 758 spin_lock(&zone->lock); 759 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED); 760 if (nr_scanned) 761 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned); 762 763 while (to_free) { 764 struct page *page; 765 struct list_head *list; 766 767 /* 768 * Remove pages from lists in a round-robin fashion. A 769 * batch_free count is maintained that is incremented when an 770 * empty list is encountered. This is so more pages are freed 771 * off fuller lists instead of spinning excessively around empty 772 * lists 773 */ 774 do { 775 batch_free++; 776 if (++migratetype == MIGRATE_PCPTYPES) 777 migratetype = 0; 778 list = &pcp->lists[migratetype]; 779 } while (list_empty(list)); 780 781 /* This is the only non-empty list. Free them all. */ 782 if (batch_free == MIGRATE_PCPTYPES) 783 batch_free = to_free; 784 785 do { 786 int mt; /* migratetype of the to-be-freed page */ 787 788 page = list_entry(list->prev, struct page, lru); 789 /* must delete as __free_one_page list manipulates */ 790 list_del(&page->lru); 791 mt = get_freepage_migratetype(page); 792 if (unlikely(has_isolate_pageblock(zone))) 793 mt = get_pageblock_migratetype(page); 794 795 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */ 796 __free_one_page(page, page_to_pfn(page), zone, 0, mt); 797 trace_mm_page_pcpu_drain(page, 0, mt); 798 } while (--to_free && --batch_free && !list_empty(list)); 799 } 800 spin_unlock(&zone->lock); 801 } 802 803 static void free_one_page(struct zone *zone, 804 struct page *page, unsigned long pfn, 805 unsigned int order, 806 int migratetype) 807 { 808 unsigned long nr_scanned; 809 spin_lock(&zone->lock); 810 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED); 811 if (nr_scanned) 812 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned); 813 814 if (unlikely(has_isolate_pageblock(zone) || 815 is_migrate_isolate(migratetype))) { 816 migratetype = get_pfnblock_migratetype(page, pfn); 817 } 818 __free_one_page(page, pfn, zone, order, migratetype); 819 spin_unlock(&zone->lock); 820 } 821 822 static int free_tail_pages_check(struct page *head_page, struct page *page) 823 { 824 if (!IS_ENABLED(CONFIG_DEBUG_VM)) 825 return 0; 826 if (unlikely(!PageTail(page))) { 827 bad_page(page, "PageTail not set", 0); 828 return 1; 829 } 830 if (unlikely(page->first_page != head_page)) { 831 bad_page(page, "first_page not consistent", 0); 832 return 1; 833 } 834 return 0; 835 } 836 837 static void __meminit __init_single_page(struct page *page, unsigned long pfn, 838 unsigned long zone, int nid) 839 { 840 set_page_links(page, zone, nid, pfn); 841 init_page_count(page); 842 page_mapcount_reset(page); 843 page_cpupid_reset_last(page); 844 845 INIT_LIST_HEAD(&page->lru); 846 #ifdef WANT_PAGE_VIRTUAL 847 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 848 if (!is_highmem_idx(zone)) 849 set_page_address(page, __va(pfn << PAGE_SHIFT)); 850 #endif 851 } 852 853 static void __meminit __init_single_pfn(unsigned long pfn, unsigned long zone, 854 int nid) 855 { 856 return __init_single_page(pfn_to_page(pfn), pfn, zone, nid); 857 } 858 859 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 860 static void init_reserved_page(unsigned long pfn) 861 { 862 pg_data_t *pgdat; 863 int nid, zid; 864 865 if (!early_page_uninitialised(pfn)) 866 return; 867 868 nid = early_pfn_to_nid(pfn); 869 pgdat = NODE_DATA(nid); 870 871 for (zid = 0; zid < MAX_NR_ZONES; zid++) { 872 struct zone *zone = &pgdat->node_zones[zid]; 873 874 if (pfn >= zone->zone_start_pfn && pfn < zone_end_pfn(zone)) 875 break; 876 } 877 __init_single_pfn(pfn, zid, nid); 878 } 879 #else 880 static inline void init_reserved_page(unsigned long pfn) 881 { 882 } 883 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ 884 885 /* 886 * Initialised pages do not have PageReserved set. This function is 887 * called for each range allocated by the bootmem allocator and 888 * marks the pages PageReserved. The remaining valid pages are later 889 * sent to the buddy page allocator. 890 */ 891 void __meminit reserve_bootmem_region(unsigned long start, unsigned long end) 892 { 893 unsigned long start_pfn = PFN_DOWN(start); 894 unsigned long end_pfn = PFN_UP(end); 895 896 for (; start_pfn < end_pfn; start_pfn++) { 897 if (pfn_valid(start_pfn)) { 898 struct page *page = pfn_to_page(start_pfn); 899 900 init_reserved_page(start_pfn); 901 SetPageReserved(page); 902 } 903 } 904 } 905 906 static bool free_pages_prepare(struct page *page, unsigned int order) 907 { 908 bool compound = PageCompound(page); 909 int i, bad = 0; 910 911 VM_BUG_ON_PAGE(PageTail(page), page); 912 VM_BUG_ON_PAGE(compound && compound_order(page) != order, page); 913 914 trace_mm_page_free(page, order); 915 kmemcheck_free_shadow(page, order); 916 kasan_free_pages(page, order); 917 918 if (PageAnon(page)) 919 page->mapping = NULL; 920 bad += free_pages_check(page); 921 for (i = 1; i < (1 << order); i++) { 922 if (compound) 923 bad += free_tail_pages_check(page, page + i); 924 bad += free_pages_check(page + i); 925 } 926 if (bad) 927 return false; 928 929 reset_page_owner(page, order); 930 931 if (!PageHighMem(page)) { 932 debug_check_no_locks_freed(page_address(page), 933 PAGE_SIZE << order); 934 debug_check_no_obj_freed(page_address(page), 935 PAGE_SIZE << order); 936 } 937 arch_free_page(page, order); 938 kernel_map_pages(page, 1 << order, 0); 939 940 return true; 941 } 942 943 static void __free_pages_ok(struct page *page, unsigned int order) 944 { 945 unsigned long flags; 946 int migratetype; 947 unsigned long pfn = page_to_pfn(page); 948 949 if (!free_pages_prepare(page, order)) 950 return; 951 952 migratetype = get_pfnblock_migratetype(page, pfn); 953 local_irq_save(flags); 954 __count_vm_events(PGFREE, 1 << order); 955 set_freepage_migratetype(page, migratetype); 956 free_one_page(page_zone(page), page, pfn, order, migratetype); 957 local_irq_restore(flags); 958 } 959 960 static void __init __free_pages_boot_core(struct page *page, 961 unsigned long pfn, unsigned int order) 962 { 963 unsigned int nr_pages = 1 << order; 964 struct page *p = page; 965 unsigned int loop; 966 967 prefetchw(p); 968 for (loop = 0; loop < (nr_pages - 1); loop++, p++) { 969 prefetchw(p + 1); 970 __ClearPageReserved(p); 971 set_page_count(p, 0); 972 } 973 __ClearPageReserved(p); 974 set_page_count(p, 0); 975 976 page_zone(page)->managed_pages += nr_pages; 977 set_page_refcounted(page); 978 __free_pages(page, order); 979 } 980 981 #if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \ 982 defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) 983 984 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata; 985 986 int __meminit early_pfn_to_nid(unsigned long pfn) 987 { 988 static DEFINE_SPINLOCK(early_pfn_lock); 989 int nid; 990 991 spin_lock(&early_pfn_lock); 992 nid = __early_pfn_to_nid(pfn, &early_pfnnid_cache); 993 if (nid < 0) 994 nid = 0; 995 spin_unlock(&early_pfn_lock); 996 997 return nid; 998 } 999 #endif 1000 1001 #ifdef CONFIG_NODES_SPAN_OTHER_NODES 1002 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node, 1003 struct mminit_pfnnid_cache *state) 1004 { 1005 int nid; 1006 1007 nid = __early_pfn_to_nid(pfn, state); 1008 if (nid >= 0 && nid != node) 1009 return false; 1010 return true; 1011 } 1012 1013 /* Only safe to use early in boot when initialisation is single-threaded */ 1014 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node) 1015 { 1016 return meminit_pfn_in_nid(pfn, node, &early_pfnnid_cache); 1017 } 1018 1019 #else 1020 1021 static inline bool __meminit early_pfn_in_nid(unsigned long pfn, int node) 1022 { 1023 return true; 1024 } 1025 static inline bool __meminit meminit_pfn_in_nid(unsigned long pfn, int node, 1026 struct mminit_pfnnid_cache *state) 1027 { 1028 return true; 1029 } 1030 #endif 1031 1032 1033 void __init __free_pages_bootmem(struct page *page, unsigned long pfn, 1034 unsigned int order) 1035 { 1036 if (early_page_uninitialised(pfn)) 1037 return; 1038 return __free_pages_boot_core(page, pfn, order); 1039 } 1040 1041 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 1042 static void __init deferred_free_range(struct page *page, 1043 unsigned long pfn, int nr_pages) 1044 { 1045 int i; 1046 1047 if (!page) 1048 return; 1049 1050 /* Free a large naturally-aligned chunk if possible */ 1051 if (nr_pages == MAX_ORDER_NR_PAGES && 1052 (pfn & (MAX_ORDER_NR_PAGES-1)) == 0) { 1053 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 1054 __free_pages_boot_core(page, pfn, MAX_ORDER-1); 1055 return; 1056 } 1057 1058 for (i = 0; i < nr_pages; i++, page++, pfn++) 1059 __free_pages_boot_core(page, pfn, 0); 1060 } 1061 1062 /* Completion tracking for deferred_init_memmap() threads */ 1063 static atomic_t pgdat_init_n_undone __initdata; 1064 static __initdata DECLARE_COMPLETION(pgdat_init_all_done_comp); 1065 1066 static inline void __init pgdat_init_report_one_done(void) 1067 { 1068 if (atomic_dec_and_test(&pgdat_init_n_undone)) 1069 complete(&pgdat_init_all_done_comp); 1070 } 1071 1072 /* Initialise remaining memory on a node */ 1073 static int __init deferred_init_memmap(void *data) 1074 { 1075 pg_data_t *pgdat = data; 1076 int nid = pgdat->node_id; 1077 struct mminit_pfnnid_cache nid_init_state = { }; 1078 unsigned long start = jiffies; 1079 unsigned long nr_pages = 0; 1080 unsigned long walk_start, walk_end; 1081 int i, zid; 1082 struct zone *zone; 1083 unsigned long first_init_pfn = pgdat->first_deferred_pfn; 1084 const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id); 1085 1086 if (first_init_pfn == ULONG_MAX) { 1087 pgdat_init_report_one_done(); 1088 return 0; 1089 } 1090 1091 /* Bind memory initialisation thread to a local node if possible */ 1092 if (!cpumask_empty(cpumask)) 1093 set_cpus_allowed_ptr(current, cpumask); 1094 1095 /* Sanity check boundaries */ 1096 BUG_ON(pgdat->first_deferred_pfn < pgdat->node_start_pfn); 1097 BUG_ON(pgdat->first_deferred_pfn > pgdat_end_pfn(pgdat)); 1098 pgdat->first_deferred_pfn = ULONG_MAX; 1099 1100 /* Only the highest zone is deferred so find it */ 1101 for (zid = 0; zid < MAX_NR_ZONES; zid++) { 1102 zone = pgdat->node_zones + zid; 1103 if (first_init_pfn < zone_end_pfn(zone)) 1104 break; 1105 } 1106 1107 for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) { 1108 unsigned long pfn, end_pfn; 1109 struct page *page = NULL; 1110 struct page *free_base_page = NULL; 1111 unsigned long free_base_pfn = 0; 1112 int nr_to_free = 0; 1113 1114 end_pfn = min(walk_end, zone_end_pfn(zone)); 1115 pfn = first_init_pfn; 1116 if (pfn < walk_start) 1117 pfn = walk_start; 1118 if (pfn < zone->zone_start_pfn) 1119 pfn = zone->zone_start_pfn; 1120 1121 for (; pfn < end_pfn; pfn++) { 1122 if (!pfn_valid_within(pfn)) 1123 goto free_range; 1124 1125 /* 1126 * Ensure pfn_valid is checked every 1127 * MAX_ORDER_NR_PAGES for memory holes 1128 */ 1129 if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) { 1130 if (!pfn_valid(pfn)) { 1131 page = NULL; 1132 goto free_range; 1133 } 1134 } 1135 1136 if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) { 1137 page = NULL; 1138 goto free_range; 1139 } 1140 1141 /* Minimise pfn page lookups and scheduler checks */ 1142 if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) { 1143 page++; 1144 } else { 1145 nr_pages += nr_to_free; 1146 deferred_free_range(free_base_page, 1147 free_base_pfn, nr_to_free); 1148 free_base_page = NULL; 1149 free_base_pfn = nr_to_free = 0; 1150 1151 page = pfn_to_page(pfn); 1152 cond_resched(); 1153 } 1154 1155 if (page->flags) { 1156 VM_BUG_ON(page_zone(page) != zone); 1157 goto free_range; 1158 } 1159 1160 __init_single_page(page, pfn, zid, nid); 1161 if (!free_base_page) { 1162 free_base_page = page; 1163 free_base_pfn = pfn; 1164 nr_to_free = 0; 1165 } 1166 nr_to_free++; 1167 1168 /* Where possible, batch up pages for a single free */ 1169 continue; 1170 free_range: 1171 /* Free the current block of pages to allocator */ 1172 nr_pages += nr_to_free; 1173 deferred_free_range(free_base_page, free_base_pfn, 1174 nr_to_free); 1175 free_base_page = NULL; 1176 free_base_pfn = nr_to_free = 0; 1177 } 1178 1179 first_init_pfn = max(end_pfn, first_init_pfn); 1180 } 1181 1182 /* Sanity check that the next zone really is unpopulated */ 1183 WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone)); 1184 1185 pr_info("node %d initialised, %lu pages in %ums\n", nid, nr_pages, 1186 jiffies_to_msecs(jiffies - start)); 1187 1188 pgdat_init_report_one_done(); 1189 return 0; 1190 } 1191 1192 void __init page_alloc_init_late(void) 1193 { 1194 int nid; 1195 1196 /* There will be num_node_state(N_MEMORY) threads */ 1197 atomic_set(&pgdat_init_n_undone, num_node_state(N_MEMORY)); 1198 for_each_node_state(nid, N_MEMORY) { 1199 kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid); 1200 } 1201 1202 /* Block until all are initialised */ 1203 wait_for_completion(&pgdat_init_all_done_comp); 1204 1205 /* Reinit limits that are based on free pages after the kernel is up */ 1206 files_maxfiles_init(); 1207 } 1208 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ 1209 1210 #ifdef CONFIG_CMA 1211 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */ 1212 void __init init_cma_reserved_pageblock(struct page *page) 1213 { 1214 unsigned i = pageblock_nr_pages; 1215 struct page *p = page; 1216 1217 do { 1218 __ClearPageReserved(p); 1219 set_page_count(p, 0); 1220 } while (++p, --i); 1221 1222 set_pageblock_migratetype(page, MIGRATE_CMA); 1223 1224 if (pageblock_order >= MAX_ORDER) { 1225 i = pageblock_nr_pages; 1226 p = page; 1227 do { 1228 set_page_refcounted(p); 1229 __free_pages(p, MAX_ORDER - 1); 1230 p += MAX_ORDER_NR_PAGES; 1231 } while (i -= MAX_ORDER_NR_PAGES); 1232 } else { 1233 set_page_refcounted(page); 1234 __free_pages(page, pageblock_order); 1235 } 1236 1237 adjust_managed_page_count(page, pageblock_nr_pages); 1238 } 1239 #endif 1240 1241 /* 1242 * The order of subdivision here is critical for the IO subsystem. 1243 * Please do not alter this order without good reasons and regression 1244 * testing. Specifically, as large blocks of memory are subdivided, 1245 * the order in which smaller blocks are delivered depends on the order 1246 * they're subdivided in this function. This is the primary factor 1247 * influencing the order in which pages are delivered to the IO 1248 * subsystem according to empirical testing, and this is also justified 1249 * by considering the behavior of a buddy system containing a single 1250 * large block of memory acted on by a series of small allocations. 1251 * This behavior is a critical factor in sglist merging's success. 1252 * 1253 * -- nyc 1254 */ 1255 static inline void expand(struct zone *zone, struct page *page, 1256 int low, int high, struct free_area *area, 1257 int migratetype) 1258 { 1259 unsigned long size = 1 << high; 1260 1261 while (high > low) { 1262 area--; 1263 high--; 1264 size >>= 1; 1265 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]); 1266 1267 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) && 1268 debug_guardpage_enabled() && 1269 high < debug_guardpage_minorder()) { 1270 /* 1271 * Mark as guard pages (or page), that will allow to 1272 * merge back to allocator when buddy will be freed. 1273 * Corresponding page table entries will not be touched, 1274 * pages will stay not present in virtual address space 1275 */ 1276 set_page_guard(zone, &page[size], high, migratetype); 1277 continue; 1278 } 1279 list_add(&page[size].lru, &area->free_list[migratetype]); 1280 area->nr_free++; 1281 set_page_order(&page[size], high); 1282 } 1283 } 1284 1285 /* 1286 * This page is about to be returned from the page allocator 1287 */ 1288 static inline int check_new_page(struct page *page) 1289 { 1290 const char *bad_reason = NULL; 1291 unsigned long bad_flags = 0; 1292 1293 if (unlikely(page_mapcount(page))) 1294 bad_reason = "nonzero mapcount"; 1295 if (unlikely(page->mapping != NULL)) 1296 bad_reason = "non-NULL mapping"; 1297 if (unlikely(atomic_read(&page->_count) != 0)) 1298 bad_reason = "nonzero _count"; 1299 if (unlikely(page->flags & __PG_HWPOISON)) { 1300 bad_reason = "HWPoisoned (hardware-corrupted)"; 1301 bad_flags = __PG_HWPOISON; 1302 } 1303 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) { 1304 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set"; 1305 bad_flags = PAGE_FLAGS_CHECK_AT_PREP; 1306 } 1307 #ifdef CONFIG_MEMCG 1308 if (unlikely(page->mem_cgroup)) 1309 bad_reason = "page still charged to cgroup"; 1310 #endif 1311 if (unlikely(bad_reason)) { 1312 bad_page(page, bad_reason, bad_flags); 1313 return 1; 1314 } 1315 return 0; 1316 } 1317 1318 static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags, 1319 int alloc_flags) 1320 { 1321 int i; 1322 1323 for (i = 0; i < (1 << order); i++) { 1324 struct page *p = page + i; 1325 if (unlikely(check_new_page(p))) 1326 return 1; 1327 } 1328 1329 set_page_private(page, 0); 1330 set_page_refcounted(page); 1331 1332 arch_alloc_page(page, order); 1333 kernel_map_pages(page, 1 << order, 1); 1334 kasan_alloc_pages(page, order); 1335 1336 if (gfp_flags & __GFP_ZERO) 1337 for (i = 0; i < (1 << order); i++) 1338 clear_highpage(page + i); 1339 1340 if (order && (gfp_flags & __GFP_COMP)) 1341 prep_compound_page(page, order); 1342 1343 set_page_owner(page, order, gfp_flags); 1344 1345 /* 1346 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to 1347 * allocate the page. The expectation is that the caller is taking 1348 * steps that will free more memory. The caller should avoid the page 1349 * being used for !PFMEMALLOC purposes. 1350 */ 1351 if (alloc_flags & ALLOC_NO_WATERMARKS) 1352 set_page_pfmemalloc(page); 1353 else 1354 clear_page_pfmemalloc(page); 1355 1356 return 0; 1357 } 1358 1359 /* 1360 * Go through the free lists for the given migratetype and remove 1361 * the smallest available page from the freelists 1362 */ 1363 static inline 1364 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, 1365 int migratetype) 1366 { 1367 unsigned int current_order; 1368 struct free_area *area; 1369 struct page *page; 1370 1371 /* Find a page of the appropriate size in the preferred list */ 1372 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 1373 area = &(zone->free_area[current_order]); 1374 if (list_empty(&area->free_list[migratetype])) 1375 continue; 1376 1377 page = list_entry(area->free_list[migratetype].next, 1378 struct page, lru); 1379 list_del(&page->lru); 1380 rmv_page_order(page); 1381 area->nr_free--; 1382 expand(zone, page, order, current_order, area, migratetype); 1383 set_freepage_migratetype(page, migratetype); 1384 return page; 1385 } 1386 1387 return NULL; 1388 } 1389 1390 1391 /* 1392 * This array describes the order lists are fallen back to when 1393 * the free lists for the desirable migrate type are depleted 1394 */ 1395 static int fallbacks[MIGRATE_TYPES][4] = { 1396 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 1397 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 1398 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, 1399 #ifdef CONFIG_CMA 1400 [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */ 1401 #endif 1402 [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */ 1403 #ifdef CONFIG_MEMORY_ISOLATION 1404 [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */ 1405 #endif 1406 }; 1407 1408 #ifdef CONFIG_CMA 1409 static struct page *__rmqueue_cma_fallback(struct zone *zone, 1410 unsigned int order) 1411 { 1412 return __rmqueue_smallest(zone, order, MIGRATE_CMA); 1413 } 1414 #else 1415 static inline struct page *__rmqueue_cma_fallback(struct zone *zone, 1416 unsigned int order) { return NULL; } 1417 #endif 1418 1419 /* 1420 * Move the free pages in a range to the free lists of the requested type. 1421 * Note that start_page and end_pages are not aligned on a pageblock 1422 * boundary. If alignment is required, use move_freepages_block() 1423 */ 1424 int move_freepages(struct zone *zone, 1425 struct page *start_page, struct page *end_page, 1426 int migratetype) 1427 { 1428 struct page *page; 1429 unsigned long order; 1430 int pages_moved = 0; 1431 1432 #ifndef CONFIG_HOLES_IN_ZONE 1433 /* 1434 * page_zone is not safe to call in this context when 1435 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant 1436 * anyway as we check zone boundaries in move_freepages_block(). 1437 * Remove at a later date when no bug reports exist related to 1438 * grouping pages by mobility 1439 */ 1440 VM_BUG_ON(page_zone(start_page) != page_zone(end_page)); 1441 #endif 1442 1443 for (page = start_page; page <= end_page;) { 1444 /* Make sure we are not inadvertently changing nodes */ 1445 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page); 1446 1447 if (!pfn_valid_within(page_to_pfn(page))) { 1448 page++; 1449 continue; 1450 } 1451 1452 if (!PageBuddy(page)) { 1453 page++; 1454 continue; 1455 } 1456 1457 order = page_order(page); 1458 list_move(&page->lru, 1459 &zone->free_area[order].free_list[migratetype]); 1460 set_freepage_migratetype(page, migratetype); 1461 page += 1 << order; 1462 pages_moved += 1 << order; 1463 } 1464 1465 return pages_moved; 1466 } 1467 1468 int move_freepages_block(struct zone *zone, struct page *page, 1469 int migratetype) 1470 { 1471 unsigned long start_pfn, end_pfn; 1472 struct page *start_page, *end_page; 1473 1474 start_pfn = page_to_pfn(page); 1475 start_pfn = start_pfn & ~(pageblock_nr_pages-1); 1476 start_page = pfn_to_page(start_pfn); 1477 end_page = start_page + pageblock_nr_pages - 1; 1478 end_pfn = start_pfn + pageblock_nr_pages - 1; 1479 1480 /* Do not cross zone boundaries */ 1481 if (!zone_spans_pfn(zone, start_pfn)) 1482 start_page = page; 1483 if (!zone_spans_pfn(zone, end_pfn)) 1484 return 0; 1485 1486 return move_freepages(zone, start_page, end_page, migratetype); 1487 } 1488 1489 static void change_pageblock_range(struct page *pageblock_page, 1490 int start_order, int migratetype) 1491 { 1492 int nr_pageblocks = 1 << (start_order - pageblock_order); 1493 1494 while (nr_pageblocks--) { 1495 set_pageblock_migratetype(pageblock_page, migratetype); 1496 pageblock_page += pageblock_nr_pages; 1497 } 1498 } 1499 1500 /* 1501 * When we are falling back to another migratetype during allocation, try to 1502 * steal extra free pages from the same pageblocks to satisfy further 1503 * allocations, instead of polluting multiple pageblocks. 1504 * 1505 * If we are stealing a relatively large buddy page, it is likely there will 1506 * be more free pages in the pageblock, so try to steal them all. For 1507 * reclaimable and unmovable allocations, we steal regardless of page size, 1508 * as fragmentation caused by those allocations polluting movable pageblocks 1509 * is worse than movable allocations stealing from unmovable and reclaimable 1510 * pageblocks. 1511 */ 1512 static bool can_steal_fallback(unsigned int order, int start_mt) 1513 { 1514 /* 1515 * Leaving this order check is intended, although there is 1516 * relaxed order check in next check. The reason is that 1517 * we can actually steal whole pageblock if this condition met, 1518 * but, below check doesn't guarantee it and that is just heuristic 1519 * so could be changed anytime. 1520 */ 1521 if (order >= pageblock_order) 1522 return true; 1523 1524 if (order >= pageblock_order / 2 || 1525 start_mt == MIGRATE_RECLAIMABLE || 1526 start_mt == MIGRATE_UNMOVABLE || 1527 page_group_by_mobility_disabled) 1528 return true; 1529 1530 return false; 1531 } 1532 1533 /* 1534 * This function implements actual steal behaviour. If order is large enough, 1535 * we can steal whole pageblock. If not, we first move freepages in this 1536 * pageblock and check whether half of pages are moved or not. If half of 1537 * pages are moved, we can change migratetype of pageblock and permanently 1538 * use it's pages as requested migratetype in the future. 1539 */ 1540 static void steal_suitable_fallback(struct zone *zone, struct page *page, 1541 int start_type) 1542 { 1543 int current_order = page_order(page); 1544 int pages; 1545 1546 /* Take ownership for orders >= pageblock_order */ 1547 if (current_order >= pageblock_order) { 1548 change_pageblock_range(page, current_order, start_type); 1549 return; 1550 } 1551 1552 pages = move_freepages_block(zone, page, start_type); 1553 1554 /* Claim the whole block if over half of it is free */ 1555 if (pages >= (1 << (pageblock_order-1)) || 1556 page_group_by_mobility_disabled) 1557 set_pageblock_migratetype(page, start_type); 1558 } 1559 1560 /* 1561 * Check whether there is a suitable fallback freepage with requested order. 1562 * If only_stealable is true, this function returns fallback_mt only if 1563 * we can steal other freepages all together. This would help to reduce 1564 * fragmentation due to mixed migratetype pages in one pageblock. 1565 */ 1566 int find_suitable_fallback(struct free_area *area, unsigned int order, 1567 int migratetype, bool only_stealable, bool *can_steal) 1568 { 1569 int i; 1570 int fallback_mt; 1571 1572 if (area->nr_free == 0) 1573 return -1; 1574 1575 *can_steal = false; 1576 for (i = 0;; i++) { 1577 fallback_mt = fallbacks[migratetype][i]; 1578 if (fallback_mt == MIGRATE_RESERVE) 1579 break; 1580 1581 if (list_empty(&area->free_list[fallback_mt])) 1582 continue; 1583 1584 if (can_steal_fallback(order, migratetype)) 1585 *can_steal = true; 1586 1587 if (!only_stealable) 1588 return fallback_mt; 1589 1590 if (*can_steal) 1591 return fallback_mt; 1592 } 1593 1594 return -1; 1595 } 1596 1597 /* Remove an element from the buddy allocator from the fallback list */ 1598 static inline struct page * 1599 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype) 1600 { 1601 struct free_area *area; 1602 unsigned int current_order; 1603 struct page *page; 1604 int fallback_mt; 1605 bool can_steal; 1606 1607 /* Find the largest possible block of pages in the other list */ 1608 for (current_order = MAX_ORDER-1; 1609 current_order >= order && current_order <= MAX_ORDER-1; 1610 --current_order) { 1611 area = &(zone->free_area[current_order]); 1612 fallback_mt = find_suitable_fallback(area, current_order, 1613 start_migratetype, false, &can_steal); 1614 if (fallback_mt == -1) 1615 continue; 1616 1617 page = list_entry(area->free_list[fallback_mt].next, 1618 struct page, lru); 1619 if (can_steal) 1620 steal_suitable_fallback(zone, page, start_migratetype); 1621 1622 /* Remove the page from the freelists */ 1623 area->nr_free--; 1624 list_del(&page->lru); 1625 rmv_page_order(page); 1626 1627 expand(zone, page, order, current_order, area, 1628 start_migratetype); 1629 /* 1630 * The freepage_migratetype may differ from pageblock's 1631 * migratetype depending on the decisions in 1632 * try_to_steal_freepages(). This is OK as long as it 1633 * does not differ for MIGRATE_CMA pageblocks. For CMA 1634 * we need to make sure unallocated pages flushed from 1635 * pcp lists are returned to the correct freelist. 1636 */ 1637 set_freepage_migratetype(page, start_migratetype); 1638 1639 trace_mm_page_alloc_extfrag(page, order, current_order, 1640 start_migratetype, fallback_mt); 1641 1642 return page; 1643 } 1644 1645 return NULL; 1646 } 1647 1648 /* 1649 * Do the hard work of removing an element from the buddy allocator. 1650 * Call me with the zone->lock already held. 1651 */ 1652 static struct page *__rmqueue(struct zone *zone, unsigned int order, 1653 int migratetype) 1654 { 1655 struct page *page; 1656 1657 retry_reserve: 1658 page = __rmqueue_smallest(zone, order, migratetype); 1659 1660 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) { 1661 if (migratetype == MIGRATE_MOVABLE) 1662 page = __rmqueue_cma_fallback(zone, order); 1663 1664 if (!page) 1665 page = __rmqueue_fallback(zone, order, migratetype); 1666 1667 /* 1668 * Use MIGRATE_RESERVE rather than fail an allocation. goto 1669 * is used because __rmqueue_smallest is an inline function 1670 * and we want just one call site 1671 */ 1672 if (!page) { 1673 migratetype = MIGRATE_RESERVE; 1674 goto retry_reserve; 1675 } 1676 } 1677 1678 trace_mm_page_alloc_zone_locked(page, order, migratetype); 1679 return page; 1680 } 1681 1682 /* 1683 * Obtain a specified number of elements from the buddy allocator, all under 1684 * a single hold of the lock, for efficiency. Add them to the supplied list. 1685 * Returns the number of new pages which were placed at *list. 1686 */ 1687 static int rmqueue_bulk(struct zone *zone, unsigned int order, 1688 unsigned long count, struct list_head *list, 1689 int migratetype, bool cold) 1690 { 1691 int i; 1692 1693 spin_lock(&zone->lock); 1694 for (i = 0; i < count; ++i) { 1695 struct page *page = __rmqueue(zone, order, migratetype); 1696 if (unlikely(page == NULL)) 1697 break; 1698 1699 /* 1700 * Split buddy pages returned by expand() are received here 1701 * in physical page order. The page is added to the callers and 1702 * list and the list head then moves forward. From the callers 1703 * perspective, the linked list is ordered by page number in 1704 * some conditions. This is useful for IO devices that can 1705 * merge IO requests if the physical pages are ordered 1706 * properly. 1707 */ 1708 if (likely(!cold)) 1709 list_add(&page->lru, list); 1710 else 1711 list_add_tail(&page->lru, list); 1712 list = &page->lru; 1713 if (is_migrate_cma(get_freepage_migratetype(page))) 1714 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1715 -(1 << order)); 1716 } 1717 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); 1718 spin_unlock(&zone->lock); 1719 return i; 1720 } 1721 1722 #ifdef CONFIG_NUMA 1723 /* 1724 * Called from the vmstat counter updater to drain pagesets of this 1725 * currently executing processor on remote nodes after they have 1726 * expired. 1727 * 1728 * Note that this function must be called with the thread pinned to 1729 * a single processor. 1730 */ 1731 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) 1732 { 1733 unsigned long flags; 1734 int to_drain, batch; 1735 1736 local_irq_save(flags); 1737 batch = READ_ONCE(pcp->batch); 1738 to_drain = min(pcp->count, batch); 1739 if (to_drain > 0) { 1740 free_pcppages_bulk(zone, to_drain, pcp); 1741 pcp->count -= to_drain; 1742 } 1743 local_irq_restore(flags); 1744 } 1745 #endif 1746 1747 /* 1748 * Drain pcplists of the indicated processor and zone. 1749 * 1750 * The processor must either be the current processor and the 1751 * thread pinned to the current processor or a processor that 1752 * is not online. 1753 */ 1754 static void drain_pages_zone(unsigned int cpu, struct zone *zone) 1755 { 1756 unsigned long flags; 1757 struct per_cpu_pageset *pset; 1758 struct per_cpu_pages *pcp; 1759 1760 local_irq_save(flags); 1761 pset = per_cpu_ptr(zone->pageset, cpu); 1762 1763 pcp = &pset->pcp; 1764 if (pcp->count) { 1765 free_pcppages_bulk(zone, pcp->count, pcp); 1766 pcp->count = 0; 1767 } 1768 local_irq_restore(flags); 1769 } 1770 1771 /* 1772 * Drain pcplists of all zones on the indicated processor. 1773 * 1774 * The processor must either be the current processor and the 1775 * thread pinned to the current processor or a processor that 1776 * is not online. 1777 */ 1778 static void drain_pages(unsigned int cpu) 1779 { 1780 struct zone *zone; 1781 1782 for_each_populated_zone(zone) { 1783 drain_pages_zone(cpu, zone); 1784 } 1785 } 1786 1787 /* 1788 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 1789 * 1790 * The CPU has to be pinned. When zone parameter is non-NULL, spill just 1791 * the single zone's pages. 1792 */ 1793 void drain_local_pages(struct zone *zone) 1794 { 1795 int cpu = smp_processor_id(); 1796 1797 if (zone) 1798 drain_pages_zone(cpu, zone); 1799 else 1800 drain_pages(cpu); 1801 } 1802 1803 /* 1804 * Spill all the per-cpu pages from all CPUs back into the buddy allocator. 1805 * 1806 * When zone parameter is non-NULL, spill just the single zone's pages. 1807 * 1808 * Note that this code is protected against sending an IPI to an offline 1809 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs: 1810 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but 1811 * nothing keeps CPUs from showing up after we populated the cpumask and 1812 * before the call to on_each_cpu_mask(). 1813 */ 1814 void drain_all_pages(struct zone *zone) 1815 { 1816 int cpu; 1817 1818 /* 1819 * Allocate in the BSS so we wont require allocation in 1820 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y 1821 */ 1822 static cpumask_t cpus_with_pcps; 1823 1824 /* 1825 * We don't care about racing with CPU hotplug event 1826 * as offline notification will cause the notified 1827 * cpu to drain that CPU pcps and on_each_cpu_mask 1828 * disables preemption as part of its processing 1829 */ 1830 for_each_online_cpu(cpu) { 1831 struct per_cpu_pageset *pcp; 1832 struct zone *z; 1833 bool has_pcps = false; 1834 1835 if (zone) { 1836 pcp = per_cpu_ptr(zone->pageset, cpu); 1837 if (pcp->pcp.count) 1838 has_pcps = true; 1839 } else { 1840 for_each_populated_zone(z) { 1841 pcp = per_cpu_ptr(z->pageset, cpu); 1842 if (pcp->pcp.count) { 1843 has_pcps = true; 1844 break; 1845 } 1846 } 1847 } 1848 1849 if (has_pcps) 1850 cpumask_set_cpu(cpu, &cpus_with_pcps); 1851 else 1852 cpumask_clear_cpu(cpu, &cpus_with_pcps); 1853 } 1854 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages, 1855 zone, 1); 1856 } 1857 1858 #ifdef CONFIG_HIBERNATION 1859 1860 void mark_free_pages(struct zone *zone) 1861 { 1862 unsigned long pfn, max_zone_pfn; 1863 unsigned long flags; 1864 unsigned int order, t; 1865 struct list_head *curr; 1866 1867 if (zone_is_empty(zone)) 1868 return; 1869 1870 spin_lock_irqsave(&zone->lock, flags); 1871 1872 max_zone_pfn = zone_end_pfn(zone); 1873 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 1874 if (pfn_valid(pfn)) { 1875 struct page *page = pfn_to_page(pfn); 1876 1877 if (!swsusp_page_is_forbidden(page)) 1878 swsusp_unset_page_free(page); 1879 } 1880 1881 for_each_migratetype_order(order, t) { 1882 list_for_each(curr, &zone->free_area[order].free_list[t]) { 1883 unsigned long i; 1884 1885 pfn = page_to_pfn(list_entry(curr, struct page, lru)); 1886 for (i = 0; i < (1UL << order); i++) 1887 swsusp_set_page_free(pfn_to_page(pfn + i)); 1888 } 1889 } 1890 spin_unlock_irqrestore(&zone->lock, flags); 1891 } 1892 #endif /* CONFIG_PM */ 1893 1894 /* 1895 * Free a 0-order page 1896 * cold == true ? free a cold page : free a hot page 1897 */ 1898 void free_hot_cold_page(struct page *page, bool cold) 1899 { 1900 struct zone *zone = page_zone(page); 1901 struct per_cpu_pages *pcp; 1902 unsigned long flags; 1903 unsigned long pfn = page_to_pfn(page); 1904 int migratetype; 1905 1906 if (!free_pages_prepare(page, 0)) 1907 return; 1908 1909 migratetype = get_pfnblock_migratetype(page, pfn); 1910 set_freepage_migratetype(page, migratetype); 1911 local_irq_save(flags); 1912 __count_vm_event(PGFREE); 1913 1914 /* 1915 * We only track unmovable, reclaimable and movable on pcp lists. 1916 * Free ISOLATE pages back to the allocator because they are being 1917 * offlined but treat RESERVE as movable pages so we can get those 1918 * areas back if necessary. Otherwise, we may have to free 1919 * excessively into the page allocator 1920 */ 1921 if (migratetype >= MIGRATE_PCPTYPES) { 1922 if (unlikely(is_migrate_isolate(migratetype))) { 1923 free_one_page(zone, page, pfn, 0, migratetype); 1924 goto out; 1925 } 1926 migratetype = MIGRATE_MOVABLE; 1927 } 1928 1929 pcp = &this_cpu_ptr(zone->pageset)->pcp; 1930 if (!cold) 1931 list_add(&page->lru, &pcp->lists[migratetype]); 1932 else 1933 list_add_tail(&page->lru, &pcp->lists[migratetype]); 1934 pcp->count++; 1935 if (pcp->count >= pcp->high) { 1936 unsigned long batch = READ_ONCE(pcp->batch); 1937 free_pcppages_bulk(zone, batch, pcp); 1938 pcp->count -= batch; 1939 } 1940 1941 out: 1942 local_irq_restore(flags); 1943 } 1944 1945 /* 1946 * Free a list of 0-order pages 1947 */ 1948 void free_hot_cold_page_list(struct list_head *list, bool cold) 1949 { 1950 struct page *page, *next; 1951 1952 list_for_each_entry_safe(page, next, list, lru) { 1953 trace_mm_page_free_batched(page, cold); 1954 free_hot_cold_page(page, cold); 1955 } 1956 } 1957 1958 /* 1959 * split_page takes a non-compound higher-order page, and splits it into 1960 * n (1<<order) sub-pages: page[0..n] 1961 * Each sub-page must be freed individually. 1962 * 1963 * Note: this is probably too low level an operation for use in drivers. 1964 * Please consult with lkml before using this in your driver. 1965 */ 1966 void split_page(struct page *page, unsigned int order) 1967 { 1968 int i; 1969 gfp_t gfp_mask; 1970 1971 VM_BUG_ON_PAGE(PageCompound(page), page); 1972 VM_BUG_ON_PAGE(!page_count(page), page); 1973 1974 #ifdef CONFIG_KMEMCHECK 1975 /* 1976 * Split shadow pages too, because free(page[0]) would 1977 * otherwise free the whole shadow. 1978 */ 1979 if (kmemcheck_page_is_tracked(page)) 1980 split_page(virt_to_page(page[0].shadow), order); 1981 #endif 1982 1983 gfp_mask = get_page_owner_gfp(page); 1984 set_page_owner(page, 0, gfp_mask); 1985 for (i = 1; i < (1 << order); i++) { 1986 set_page_refcounted(page + i); 1987 set_page_owner(page + i, 0, gfp_mask); 1988 } 1989 } 1990 EXPORT_SYMBOL_GPL(split_page); 1991 1992 int __isolate_free_page(struct page *page, unsigned int order) 1993 { 1994 unsigned long watermark; 1995 struct zone *zone; 1996 int mt; 1997 1998 BUG_ON(!PageBuddy(page)); 1999 2000 zone = page_zone(page); 2001 mt = get_pageblock_migratetype(page); 2002 2003 if (!is_migrate_isolate(mt)) { 2004 /* Obey watermarks as if the page was being allocated */ 2005 watermark = low_wmark_pages(zone) + (1 << order); 2006 if (!zone_watermark_ok(zone, 0, watermark, 0, 0)) 2007 return 0; 2008 2009 __mod_zone_freepage_state(zone, -(1UL << order), mt); 2010 } 2011 2012 /* Remove page from free list */ 2013 list_del(&page->lru); 2014 zone->free_area[order].nr_free--; 2015 rmv_page_order(page); 2016 2017 set_page_owner(page, order, __GFP_MOVABLE); 2018 2019 /* Set the pageblock if the isolated page is at least a pageblock */ 2020 if (order >= pageblock_order - 1) { 2021 struct page *endpage = page + (1 << order) - 1; 2022 for (; page < endpage; page += pageblock_nr_pages) { 2023 int mt = get_pageblock_migratetype(page); 2024 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt)) 2025 set_pageblock_migratetype(page, 2026 MIGRATE_MOVABLE); 2027 } 2028 } 2029 2030 2031 return 1UL << order; 2032 } 2033 2034 /* 2035 * Similar to split_page except the page is already free. As this is only 2036 * being used for migration, the migratetype of the block also changes. 2037 * As this is called with interrupts disabled, the caller is responsible 2038 * for calling arch_alloc_page() and kernel_map_page() after interrupts 2039 * are enabled. 2040 * 2041 * Note: this is probably too low level an operation for use in drivers. 2042 * Please consult with lkml before using this in your driver. 2043 */ 2044 int split_free_page(struct page *page) 2045 { 2046 unsigned int order; 2047 int nr_pages; 2048 2049 order = page_order(page); 2050 2051 nr_pages = __isolate_free_page(page, order); 2052 if (!nr_pages) 2053 return 0; 2054 2055 /* Split into individual pages */ 2056 set_page_refcounted(page); 2057 split_page(page, order); 2058 return nr_pages; 2059 } 2060 2061 /* 2062 * Allocate a page from the given zone. Use pcplists for order-0 allocations. 2063 */ 2064 static inline 2065 struct page *buffered_rmqueue(struct zone *preferred_zone, 2066 struct zone *zone, unsigned int order, 2067 gfp_t gfp_flags, int migratetype) 2068 { 2069 unsigned long flags; 2070 struct page *page; 2071 bool cold = ((gfp_flags & __GFP_COLD) != 0); 2072 2073 if (likely(order == 0)) { 2074 struct per_cpu_pages *pcp; 2075 struct list_head *list; 2076 2077 local_irq_save(flags); 2078 pcp = &this_cpu_ptr(zone->pageset)->pcp; 2079 list = &pcp->lists[migratetype]; 2080 if (list_empty(list)) { 2081 pcp->count += rmqueue_bulk(zone, 0, 2082 pcp->batch, list, 2083 migratetype, cold); 2084 if (unlikely(list_empty(list))) 2085 goto failed; 2086 } 2087 2088 if (cold) 2089 page = list_entry(list->prev, struct page, lru); 2090 else 2091 page = list_entry(list->next, struct page, lru); 2092 2093 list_del(&page->lru); 2094 pcp->count--; 2095 } else { 2096 if (unlikely(gfp_flags & __GFP_NOFAIL)) { 2097 /* 2098 * __GFP_NOFAIL is not to be used in new code. 2099 * 2100 * All __GFP_NOFAIL callers should be fixed so that they 2101 * properly detect and handle allocation failures. 2102 * 2103 * We most definitely don't want callers attempting to 2104 * allocate greater than order-1 page units with 2105 * __GFP_NOFAIL. 2106 */ 2107 WARN_ON_ONCE(order > 1); 2108 } 2109 spin_lock_irqsave(&zone->lock, flags); 2110 page = __rmqueue(zone, order, migratetype); 2111 spin_unlock(&zone->lock); 2112 if (!page) 2113 goto failed; 2114 __mod_zone_freepage_state(zone, -(1 << order), 2115 get_freepage_migratetype(page)); 2116 } 2117 2118 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order)); 2119 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 && 2120 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) 2121 set_bit(ZONE_FAIR_DEPLETED, &zone->flags); 2122 2123 __count_zone_vm_events(PGALLOC, zone, 1 << order); 2124 zone_statistics(preferred_zone, zone, gfp_flags); 2125 local_irq_restore(flags); 2126 2127 VM_BUG_ON_PAGE(bad_range(zone, page), page); 2128 return page; 2129 2130 failed: 2131 local_irq_restore(flags); 2132 return NULL; 2133 } 2134 2135 #ifdef CONFIG_FAIL_PAGE_ALLOC 2136 2137 static struct { 2138 struct fault_attr attr; 2139 2140 u32 ignore_gfp_highmem; 2141 u32 ignore_gfp_wait; 2142 u32 min_order; 2143 } fail_page_alloc = { 2144 .attr = FAULT_ATTR_INITIALIZER, 2145 .ignore_gfp_wait = 1, 2146 .ignore_gfp_highmem = 1, 2147 .min_order = 1, 2148 }; 2149 2150 static int __init setup_fail_page_alloc(char *str) 2151 { 2152 return setup_fault_attr(&fail_page_alloc.attr, str); 2153 } 2154 __setup("fail_page_alloc=", setup_fail_page_alloc); 2155 2156 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 2157 { 2158 if (order < fail_page_alloc.min_order) 2159 return false; 2160 if (gfp_mask & __GFP_NOFAIL) 2161 return false; 2162 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 2163 return false; 2164 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) 2165 return false; 2166 2167 return should_fail(&fail_page_alloc.attr, 1 << order); 2168 } 2169 2170 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 2171 2172 static int __init fail_page_alloc_debugfs(void) 2173 { 2174 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR; 2175 struct dentry *dir; 2176 2177 dir = fault_create_debugfs_attr("fail_page_alloc", NULL, 2178 &fail_page_alloc.attr); 2179 if (IS_ERR(dir)) 2180 return PTR_ERR(dir); 2181 2182 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir, 2183 &fail_page_alloc.ignore_gfp_wait)) 2184 goto fail; 2185 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir, 2186 &fail_page_alloc.ignore_gfp_highmem)) 2187 goto fail; 2188 if (!debugfs_create_u32("min-order", mode, dir, 2189 &fail_page_alloc.min_order)) 2190 goto fail; 2191 2192 return 0; 2193 fail: 2194 debugfs_remove_recursive(dir); 2195 2196 return -ENOMEM; 2197 } 2198 2199 late_initcall(fail_page_alloc_debugfs); 2200 2201 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 2202 2203 #else /* CONFIG_FAIL_PAGE_ALLOC */ 2204 2205 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 2206 { 2207 return false; 2208 } 2209 2210 #endif /* CONFIG_FAIL_PAGE_ALLOC */ 2211 2212 /* 2213 * Return true if free pages are above 'mark'. This takes into account the order 2214 * of the allocation. 2215 */ 2216 static bool __zone_watermark_ok(struct zone *z, unsigned int order, 2217 unsigned long mark, int classzone_idx, int alloc_flags, 2218 long free_pages) 2219 { 2220 /* free_pages may go negative - that's OK */ 2221 long min = mark; 2222 int o; 2223 long free_cma = 0; 2224 2225 free_pages -= (1 << order) - 1; 2226 if (alloc_flags & ALLOC_HIGH) 2227 min -= min / 2; 2228 if (alloc_flags & ALLOC_HARDER) 2229 min -= min / 4; 2230 #ifdef CONFIG_CMA 2231 /* If allocation can't use CMA areas don't use free CMA pages */ 2232 if (!(alloc_flags & ALLOC_CMA)) 2233 free_cma = zone_page_state(z, NR_FREE_CMA_PAGES); 2234 #endif 2235 2236 if (free_pages - free_cma <= min + z->lowmem_reserve[classzone_idx]) 2237 return false; 2238 for (o = 0; o < order; o++) { 2239 /* At the next order, this order's pages become unavailable */ 2240 free_pages -= z->free_area[o].nr_free << o; 2241 2242 /* Require fewer higher order pages to be free */ 2243 min >>= 1; 2244 2245 if (free_pages <= min) 2246 return false; 2247 } 2248 return true; 2249 } 2250 2251 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, 2252 int classzone_idx, int alloc_flags) 2253 { 2254 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, 2255 zone_page_state(z, NR_FREE_PAGES)); 2256 } 2257 2258 bool zone_watermark_ok_safe(struct zone *z, unsigned int order, 2259 unsigned long mark, int classzone_idx, int alloc_flags) 2260 { 2261 long free_pages = zone_page_state(z, NR_FREE_PAGES); 2262 2263 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark) 2264 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES); 2265 2266 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, 2267 free_pages); 2268 } 2269 2270 #ifdef CONFIG_NUMA 2271 /* 2272 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to 2273 * skip over zones that are not allowed by the cpuset, or that have 2274 * been recently (in last second) found to be nearly full. See further 2275 * comments in mmzone.h. Reduces cache footprint of zonelist scans 2276 * that have to skip over a lot of full or unallowed zones. 2277 * 2278 * If the zonelist cache is present in the passed zonelist, then 2279 * returns a pointer to the allowed node mask (either the current 2280 * tasks mems_allowed, or node_states[N_MEMORY].) 2281 * 2282 * If the zonelist cache is not available for this zonelist, does 2283 * nothing and returns NULL. 2284 * 2285 * If the fullzones BITMAP in the zonelist cache is stale (more than 2286 * a second since last zap'd) then we zap it out (clear its bits.) 2287 * 2288 * We hold off even calling zlc_setup, until after we've checked the 2289 * first zone in the zonelist, on the theory that most allocations will 2290 * be satisfied from that first zone, so best to examine that zone as 2291 * quickly as we can. 2292 */ 2293 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 2294 { 2295 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 2296 nodemask_t *allowednodes; /* zonelist_cache approximation */ 2297 2298 zlc = zonelist->zlcache_ptr; 2299 if (!zlc) 2300 return NULL; 2301 2302 if (time_after(jiffies, zlc->last_full_zap + HZ)) { 2303 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 2304 zlc->last_full_zap = jiffies; 2305 } 2306 2307 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? 2308 &cpuset_current_mems_allowed : 2309 &node_states[N_MEMORY]; 2310 return allowednodes; 2311 } 2312 2313 /* 2314 * Given 'z' scanning a zonelist, run a couple of quick checks to see 2315 * if it is worth looking at further for free memory: 2316 * 1) Check that the zone isn't thought to be full (doesn't have its 2317 * bit set in the zonelist_cache fullzones BITMAP). 2318 * 2) Check that the zones node (obtained from the zonelist_cache 2319 * z_to_n[] mapping) is allowed in the passed in allowednodes mask. 2320 * Return true (non-zero) if zone is worth looking at further, or 2321 * else return false (zero) if it is not. 2322 * 2323 * This check -ignores- the distinction between various watermarks, 2324 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is 2325 * found to be full for any variation of these watermarks, it will 2326 * be considered full for up to one second by all requests, unless 2327 * we are so low on memory on all allowed nodes that we are forced 2328 * into the second scan of the zonelist. 2329 * 2330 * In the second scan we ignore this zonelist cache and exactly 2331 * apply the watermarks to all zones, even it is slower to do so. 2332 * We are low on memory in the second scan, and should leave no stone 2333 * unturned looking for a free page. 2334 */ 2335 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 2336 nodemask_t *allowednodes) 2337 { 2338 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 2339 int i; /* index of *z in zonelist zones */ 2340 int n; /* node that zone *z is on */ 2341 2342 zlc = zonelist->zlcache_ptr; 2343 if (!zlc) 2344 return 1; 2345 2346 i = z - zonelist->_zonerefs; 2347 n = zlc->z_to_n[i]; 2348 2349 /* This zone is worth trying if it is allowed but not full */ 2350 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); 2351 } 2352 2353 /* 2354 * Given 'z' scanning a zonelist, set the corresponding bit in 2355 * zlc->fullzones, so that subsequent attempts to allocate a page 2356 * from that zone don't waste time re-examining it. 2357 */ 2358 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 2359 { 2360 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 2361 int i; /* index of *z in zonelist zones */ 2362 2363 zlc = zonelist->zlcache_ptr; 2364 if (!zlc) 2365 return; 2366 2367 i = z - zonelist->_zonerefs; 2368 2369 set_bit(i, zlc->fullzones); 2370 } 2371 2372 /* 2373 * clear all zones full, called after direct reclaim makes progress so that 2374 * a zone that was recently full is not skipped over for up to a second 2375 */ 2376 static void zlc_clear_zones_full(struct zonelist *zonelist) 2377 { 2378 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 2379 2380 zlc = zonelist->zlcache_ptr; 2381 if (!zlc) 2382 return; 2383 2384 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 2385 } 2386 2387 static bool zone_local(struct zone *local_zone, struct zone *zone) 2388 { 2389 return local_zone->node == zone->node; 2390 } 2391 2392 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) 2393 { 2394 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) < 2395 RECLAIM_DISTANCE; 2396 } 2397 2398 #else /* CONFIG_NUMA */ 2399 2400 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 2401 { 2402 return NULL; 2403 } 2404 2405 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 2406 nodemask_t *allowednodes) 2407 { 2408 return 1; 2409 } 2410 2411 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 2412 { 2413 } 2414 2415 static void zlc_clear_zones_full(struct zonelist *zonelist) 2416 { 2417 } 2418 2419 static bool zone_local(struct zone *local_zone, struct zone *zone) 2420 { 2421 return true; 2422 } 2423 2424 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) 2425 { 2426 return true; 2427 } 2428 2429 #endif /* CONFIG_NUMA */ 2430 2431 static void reset_alloc_batches(struct zone *preferred_zone) 2432 { 2433 struct zone *zone = preferred_zone->zone_pgdat->node_zones; 2434 2435 do { 2436 mod_zone_page_state(zone, NR_ALLOC_BATCH, 2437 high_wmark_pages(zone) - low_wmark_pages(zone) - 2438 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH])); 2439 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags); 2440 } while (zone++ != preferred_zone); 2441 } 2442 2443 /* 2444 * get_page_from_freelist goes through the zonelist trying to allocate 2445 * a page. 2446 */ 2447 static struct page * 2448 get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, 2449 const struct alloc_context *ac) 2450 { 2451 struct zonelist *zonelist = ac->zonelist; 2452 struct zoneref *z; 2453 struct page *page = NULL; 2454 struct zone *zone; 2455 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ 2456 int zlc_active = 0; /* set if using zonelist_cache */ 2457 int did_zlc_setup = 0; /* just call zlc_setup() one time */ 2458 bool consider_zone_dirty = (alloc_flags & ALLOC_WMARK_LOW) && 2459 (gfp_mask & __GFP_WRITE); 2460 int nr_fair_skipped = 0; 2461 bool zonelist_rescan; 2462 2463 zonelist_scan: 2464 zonelist_rescan = false; 2465 2466 /* 2467 * Scan zonelist, looking for a zone with enough free. 2468 * See also __cpuset_node_allowed() comment in kernel/cpuset.c. 2469 */ 2470 for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx, 2471 ac->nodemask) { 2472 unsigned long mark; 2473 2474 if (IS_ENABLED(CONFIG_NUMA) && zlc_active && 2475 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 2476 continue; 2477 if (cpusets_enabled() && 2478 (alloc_flags & ALLOC_CPUSET) && 2479 !cpuset_zone_allowed(zone, gfp_mask)) 2480 continue; 2481 /* 2482 * Distribute pages in proportion to the individual 2483 * zone size to ensure fair page aging. The zone a 2484 * page was allocated in should have no effect on the 2485 * time the page has in memory before being reclaimed. 2486 */ 2487 if (alloc_flags & ALLOC_FAIR) { 2488 if (!zone_local(ac->preferred_zone, zone)) 2489 break; 2490 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) { 2491 nr_fair_skipped++; 2492 continue; 2493 } 2494 } 2495 /* 2496 * When allocating a page cache page for writing, we 2497 * want to get it from a zone that is within its dirty 2498 * limit, such that no single zone holds more than its 2499 * proportional share of globally allowed dirty pages. 2500 * The dirty limits take into account the zone's 2501 * lowmem reserves and high watermark so that kswapd 2502 * should be able to balance it without having to 2503 * write pages from its LRU list. 2504 * 2505 * This may look like it could increase pressure on 2506 * lower zones by failing allocations in higher zones 2507 * before they are full. But the pages that do spill 2508 * over are limited as the lower zones are protected 2509 * by this very same mechanism. It should not become 2510 * a practical burden to them. 2511 * 2512 * XXX: For now, allow allocations to potentially 2513 * exceed the per-zone dirty limit in the slowpath 2514 * (ALLOC_WMARK_LOW unset) before going into reclaim, 2515 * which is important when on a NUMA setup the allowed 2516 * zones are together not big enough to reach the 2517 * global limit. The proper fix for these situations 2518 * will require awareness of zones in the 2519 * dirty-throttling and the flusher threads. 2520 */ 2521 if (consider_zone_dirty && !zone_dirty_ok(zone)) 2522 continue; 2523 2524 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK]; 2525 if (!zone_watermark_ok(zone, order, mark, 2526 ac->classzone_idx, alloc_flags)) { 2527 int ret; 2528 2529 /* Checked here to keep the fast path fast */ 2530 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK); 2531 if (alloc_flags & ALLOC_NO_WATERMARKS) 2532 goto try_this_zone; 2533 2534 if (IS_ENABLED(CONFIG_NUMA) && 2535 !did_zlc_setup && nr_online_nodes > 1) { 2536 /* 2537 * we do zlc_setup if there are multiple nodes 2538 * and before considering the first zone allowed 2539 * by the cpuset. 2540 */ 2541 allowednodes = zlc_setup(zonelist, alloc_flags); 2542 zlc_active = 1; 2543 did_zlc_setup = 1; 2544 } 2545 2546 if (zone_reclaim_mode == 0 || 2547 !zone_allows_reclaim(ac->preferred_zone, zone)) 2548 goto this_zone_full; 2549 2550 /* 2551 * As we may have just activated ZLC, check if the first 2552 * eligible zone has failed zone_reclaim recently. 2553 */ 2554 if (IS_ENABLED(CONFIG_NUMA) && zlc_active && 2555 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 2556 continue; 2557 2558 ret = zone_reclaim(zone, gfp_mask, order); 2559 switch (ret) { 2560 case ZONE_RECLAIM_NOSCAN: 2561 /* did not scan */ 2562 continue; 2563 case ZONE_RECLAIM_FULL: 2564 /* scanned but unreclaimable */ 2565 continue; 2566 default: 2567 /* did we reclaim enough */ 2568 if (zone_watermark_ok(zone, order, mark, 2569 ac->classzone_idx, alloc_flags)) 2570 goto try_this_zone; 2571 2572 /* 2573 * Failed to reclaim enough to meet watermark. 2574 * Only mark the zone full if checking the min 2575 * watermark or if we failed to reclaim just 2576 * 1<<order pages or else the page allocator 2577 * fastpath will prematurely mark zones full 2578 * when the watermark is between the low and 2579 * min watermarks. 2580 */ 2581 if (((alloc_flags & ALLOC_WMARK_MASK) == ALLOC_WMARK_MIN) || 2582 ret == ZONE_RECLAIM_SOME) 2583 goto this_zone_full; 2584 2585 continue; 2586 } 2587 } 2588 2589 try_this_zone: 2590 page = buffered_rmqueue(ac->preferred_zone, zone, order, 2591 gfp_mask, ac->migratetype); 2592 if (page) { 2593 if (prep_new_page(page, order, gfp_mask, alloc_flags)) 2594 goto try_this_zone; 2595 return page; 2596 } 2597 this_zone_full: 2598 if (IS_ENABLED(CONFIG_NUMA) && zlc_active) 2599 zlc_mark_zone_full(zonelist, z); 2600 } 2601 2602 /* 2603 * The first pass makes sure allocations are spread fairly within the 2604 * local node. However, the local node might have free pages left 2605 * after the fairness batches are exhausted, and remote zones haven't 2606 * even been considered yet. Try once more without fairness, and 2607 * include remote zones now, before entering the slowpath and waking 2608 * kswapd: prefer spilling to a remote zone over swapping locally. 2609 */ 2610 if (alloc_flags & ALLOC_FAIR) { 2611 alloc_flags &= ~ALLOC_FAIR; 2612 if (nr_fair_skipped) { 2613 zonelist_rescan = true; 2614 reset_alloc_batches(ac->preferred_zone); 2615 } 2616 if (nr_online_nodes > 1) 2617 zonelist_rescan = true; 2618 } 2619 2620 if (unlikely(IS_ENABLED(CONFIG_NUMA) && zlc_active)) { 2621 /* Disable zlc cache for second zonelist scan */ 2622 zlc_active = 0; 2623 zonelist_rescan = true; 2624 } 2625 2626 if (zonelist_rescan) 2627 goto zonelist_scan; 2628 2629 return NULL; 2630 } 2631 2632 /* 2633 * Large machines with many possible nodes should not always dump per-node 2634 * meminfo in irq context. 2635 */ 2636 static inline bool should_suppress_show_mem(void) 2637 { 2638 bool ret = false; 2639 2640 #if NODES_SHIFT > 8 2641 ret = in_interrupt(); 2642 #endif 2643 return ret; 2644 } 2645 2646 static DEFINE_RATELIMIT_STATE(nopage_rs, 2647 DEFAULT_RATELIMIT_INTERVAL, 2648 DEFAULT_RATELIMIT_BURST); 2649 2650 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...) 2651 { 2652 unsigned int filter = SHOW_MEM_FILTER_NODES; 2653 2654 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) || 2655 debug_guardpage_minorder() > 0) 2656 return; 2657 2658 /* 2659 * This documents exceptions given to allocations in certain 2660 * contexts that are allowed to allocate outside current's set 2661 * of allowed nodes. 2662 */ 2663 if (!(gfp_mask & __GFP_NOMEMALLOC)) 2664 if (test_thread_flag(TIF_MEMDIE) || 2665 (current->flags & (PF_MEMALLOC | PF_EXITING))) 2666 filter &= ~SHOW_MEM_FILTER_NODES; 2667 if (in_interrupt() || !(gfp_mask & __GFP_WAIT)) 2668 filter &= ~SHOW_MEM_FILTER_NODES; 2669 2670 if (fmt) { 2671 struct va_format vaf; 2672 va_list args; 2673 2674 va_start(args, fmt); 2675 2676 vaf.fmt = fmt; 2677 vaf.va = &args; 2678 2679 pr_warn("%pV", &vaf); 2680 2681 va_end(args); 2682 } 2683 2684 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n", 2685 current->comm, order, gfp_mask); 2686 2687 dump_stack(); 2688 if (!should_suppress_show_mem()) 2689 show_mem(filter); 2690 } 2691 2692 static inline struct page * 2693 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, 2694 const struct alloc_context *ac, unsigned long *did_some_progress) 2695 { 2696 struct page *page; 2697 2698 *did_some_progress = 0; 2699 2700 /* 2701 * Acquire the oom lock. If that fails, somebody else is 2702 * making progress for us. 2703 */ 2704 if (!mutex_trylock(&oom_lock)) { 2705 *did_some_progress = 1; 2706 schedule_timeout_uninterruptible(1); 2707 return NULL; 2708 } 2709 2710 /* 2711 * Go through the zonelist yet one more time, keep very high watermark 2712 * here, this is only to catch a parallel oom killing, we must fail if 2713 * we're still under heavy pressure. 2714 */ 2715 page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order, 2716 ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac); 2717 if (page) 2718 goto out; 2719 2720 if (!(gfp_mask & __GFP_NOFAIL)) { 2721 /* Coredumps can quickly deplete all memory reserves */ 2722 if (current->flags & PF_DUMPCORE) 2723 goto out; 2724 /* The OOM killer will not help higher order allocs */ 2725 if (order > PAGE_ALLOC_COSTLY_ORDER) 2726 goto out; 2727 /* The OOM killer does not needlessly kill tasks for lowmem */ 2728 if (ac->high_zoneidx < ZONE_NORMAL) 2729 goto out; 2730 /* The OOM killer does not compensate for IO-less reclaim */ 2731 if (!(gfp_mask & __GFP_FS)) { 2732 /* 2733 * XXX: Page reclaim didn't yield anything, 2734 * and the OOM killer can't be invoked, but 2735 * keep looping as per tradition. 2736 */ 2737 *did_some_progress = 1; 2738 goto out; 2739 } 2740 if (pm_suspended_storage()) 2741 goto out; 2742 /* The OOM killer may not free memory on a specific node */ 2743 if (gfp_mask & __GFP_THISNODE) 2744 goto out; 2745 } 2746 /* Exhausted what can be done so it's blamo time */ 2747 if (out_of_memory(ac->zonelist, gfp_mask, order, ac->nodemask, false) 2748 || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) 2749 *did_some_progress = 1; 2750 out: 2751 mutex_unlock(&oom_lock); 2752 return page; 2753 } 2754 2755 #ifdef CONFIG_COMPACTION 2756 /* Try memory compaction for high-order allocations before reclaim */ 2757 static struct page * 2758 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, 2759 int alloc_flags, const struct alloc_context *ac, 2760 enum migrate_mode mode, int *contended_compaction, 2761 bool *deferred_compaction) 2762 { 2763 unsigned long compact_result; 2764 struct page *page; 2765 2766 if (!order) 2767 return NULL; 2768 2769 current->flags |= PF_MEMALLOC; 2770 compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac, 2771 mode, contended_compaction); 2772 current->flags &= ~PF_MEMALLOC; 2773 2774 switch (compact_result) { 2775 case COMPACT_DEFERRED: 2776 *deferred_compaction = true; 2777 /* fall-through */ 2778 case COMPACT_SKIPPED: 2779 return NULL; 2780 default: 2781 break; 2782 } 2783 2784 /* 2785 * At least in one zone compaction wasn't deferred or skipped, so let's 2786 * count a compaction stall 2787 */ 2788 count_vm_event(COMPACTSTALL); 2789 2790 page = get_page_from_freelist(gfp_mask, order, 2791 alloc_flags & ~ALLOC_NO_WATERMARKS, ac); 2792 2793 if (page) { 2794 struct zone *zone = page_zone(page); 2795 2796 zone->compact_blockskip_flush = false; 2797 compaction_defer_reset(zone, order, true); 2798 count_vm_event(COMPACTSUCCESS); 2799 return page; 2800 } 2801 2802 /* 2803 * It's bad if compaction run occurs and fails. The most likely reason 2804 * is that pages exist, but not enough to satisfy watermarks. 2805 */ 2806 count_vm_event(COMPACTFAIL); 2807 2808 cond_resched(); 2809 2810 return NULL; 2811 } 2812 #else 2813 static inline struct page * 2814 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, 2815 int alloc_flags, const struct alloc_context *ac, 2816 enum migrate_mode mode, int *contended_compaction, 2817 bool *deferred_compaction) 2818 { 2819 return NULL; 2820 } 2821 #endif /* CONFIG_COMPACTION */ 2822 2823 /* Perform direct synchronous page reclaim */ 2824 static int 2825 __perform_reclaim(gfp_t gfp_mask, unsigned int order, 2826 const struct alloc_context *ac) 2827 { 2828 struct reclaim_state reclaim_state; 2829 int progress; 2830 2831 cond_resched(); 2832 2833 /* We now go into synchronous reclaim */ 2834 cpuset_memory_pressure_bump(); 2835 current->flags |= PF_MEMALLOC; 2836 lockdep_set_current_reclaim_state(gfp_mask); 2837 reclaim_state.reclaimed_slab = 0; 2838 current->reclaim_state = &reclaim_state; 2839 2840 progress = try_to_free_pages(ac->zonelist, order, gfp_mask, 2841 ac->nodemask); 2842 2843 current->reclaim_state = NULL; 2844 lockdep_clear_current_reclaim_state(); 2845 current->flags &= ~PF_MEMALLOC; 2846 2847 cond_resched(); 2848 2849 return progress; 2850 } 2851 2852 /* The really slow allocator path where we enter direct reclaim */ 2853 static inline struct page * 2854 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order, 2855 int alloc_flags, const struct alloc_context *ac, 2856 unsigned long *did_some_progress) 2857 { 2858 struct page *page = NULL; 2859 bool drained = false; 2860 2861 *did_some_progress = __perform_reclaim(gfp_mask, order, ac); 2862 if (unlikely(!(*did_some_progress))) 2863 return NULL; 2864 2865 /* After successful reclaim, reconsider all zones for allocation */ 2866 if (IS_ENABLED(CONFIG_NUMA)) 2867 zlc_clear_zones_full(ac->zonelist); 2868 2869 retry: 2870 page = get_page_from_freelist(gfp_mask, order, 2871 alloc_flags & ~ALLOC_NO_WATERMARKS, ac); 2872 2873 /* 2874 * If an allocation failed after direct reclaim, it could be because 2875 * pages are pinned on the per-cpu lists. Drain them and try again 2876 */ 2877 if (!page && !drained) { 2878 drain_all_pages(NULL); 2879 drained = true; 2880 goto retry; 2881 } 2882 2883 return page; 2884 } 2885 2886 /* 2887 * This is called in the allocator slow-path if the allocation request is of 2888 * sufficient urgency to ignore watermarks and take other desperate measures 2889 */ 2890 static inline struct page * 2891 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order, 2892 const struct alloc_context *ac) 2893 { 2894 struct page *page; 2895 2896 do { 2897 page = get_page_from_freelist(gfp_mask, order, 2898 ALLOC_NO_WATERMARKS, ac); 2899 2900 if (!page && gfp_mask & __GFP_NOFAIL) 2901 wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, 2902 HZ/50); 2903 } while (!page && (gfp_mask & __GFP_NOFAIL)); 2904 2905 return page; 2906 } 2907 2908 static void wake_all_kswapds(unsigned int order, const struct alloc_context *ac) 2909 { 2910 struct zoneref *z; 2911 struct zone *zone; 2912 2913 for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, 2914 ac->high_zoneidx, ac->nodemask) 2915 wakeup_kswapd(zone, order, zone_idx(ac->preferred_zone)); 2916 } 2917 2918 static inline int 2919 gfp_to_alloc_flags(gfp_t gfp_mask) 2920 { 2921 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; 2922 const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD)); 2923 2924 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */ 2925 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH); 2926 2927 /* 2928 * The caller may dip into page reserves a bit more if the caller 2929 * cannot run direct reclaim, or if the caller has realtime scheduling 2930 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will 2931 * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH). 2932 */ 2933 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH); 2934 2935 if (atomic) { 2936 /* 2937 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even 2938 * if it can't schedule. 2939 */ 2940 if (!(gfp_mask & __GFP_NOMEMALLOC)) 2941 alloc_flags |= ALLOC_HARDER; 2942 /* 2943 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the 2944 * comment for __cpuset_node_allowed(). 2945 */ 2946 alloc_flags &= ~ALLOC_CPUSET; 2947 } else if (unlikely(rt_task(current)) && !in_interrupt()) 2948 alloc_flags |= ALLOC_HARDER; 2949 2950 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) { 2951 if (gfp_mask & __GFP_MEMALLOC) 2952 alloc_flags |= ALLOC_NO_WATERMARKS; 2953 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC)) 2954 alloc_flags |= ALLOC_NO_WATERMARKS; 2955 else if (!in_interrupt() && 2956 ((current->flags & PF_MEMALLOC) || 2957 unlikely(test_thread_flag(TIF_MEMDIE)))) 2958 alloc_flags |= ALLOC_NO_WATERMARKS; 2959 } 2960 #ifdef CONFIG_CMA 2961 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE) 2962 alloc_flags |= ALLOC_CMA; 2963 #endif 2964 return alloc_flags; 2965 } 2966 2967 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask) 2968 { 2969 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS); 2970 } 2971 2972 static inline struct page * 2973 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, 2974 struct alloc_context *ac) 2975 { 2976 const gfp_t wait = gfp_mask & __GFP_WAIT; 2977 struct page *page = NULL; 2978 int alloc_flags; 2979 unsigned long pages_reclaimed = 0; 2980 unsigned long did_some_progress; 2981 enum migrate_mode migration_mode = MIGRATE_ASYNC; 2982 bool deferred_compaction = false; 2983 int contended_compaction = COMPACT_CONTENDED_NONE; 2984 2985 /* 2986 * In the slowpath, we sanity check order to avoid ever trying to 2987 * reclaim >= MAX_ORDER areas which will never succeed. Callers may 2988 * be using allocators in order of preference for an area that is 2989 * too large. 2990 */ 2991 if (order >= MAX_ORDER) { 2992 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN)); 2993 return NULL; 2994 } 2995 2996 /* 2997 * If this allocation cannot block and it is for a specific node, then 2998 * fail early. There's no need to wakeup kswapd or retry for a 2999 * speculative node-specific allocation. 3000 */ 3001 if (IS_ENABLED(CONFIG_NUMA) && (gfp_mask & __GFP_THISNODE) && !wait) 3002 goto nopage; 3003 3004 retry: 3005 if (!(gfp_mask & __GFP_NO_KSWAPD)) 3006 wake_all_kswapds(order, ac); 3007 3008 /* 3009 * OK, we're below the kswapd watermark and have kicked background 3010 * reclaim. Now things get more complex, so set up alloc_flags according 3011 * to how we want to proceed. 3012 */ 3013 alloc_flags = gfp_to_alloc_flags(gfp_mask); 3014 3015 /* 3016 * Find the true preferred zone if the allocation is unconstrained by 3017 * cpusets. 3018 */ 3019 if (!(alloc_flags & ALLOC_CPUSET) && !ac->nodemask) { 3020 struct zoneref *preferred_zoneref; 3021 preferred_zoneref = first_zones_zonelist(ac->zonelist, 3022 ac->high_zoneidx, NULL, &ac->preferred_zone); 3023 ac->classzone_idx = zonelist_zone_idx(preferred_zoneref); 3024 } 3025 3026 /* This is the last chance, in general, before the goto nopage. */ 3027 page = get_page_from_freelist(gfp_mask, order, 3028 alloc_flags & ~ALLOC_NO_WATERMARKS, ac); 3029 if (page) 3030 goto got_pg; 3031 3032 /* Allocate without watermarks if the context allows */ 3033 if (alloc_flags & ALLOC_NO_WATERMARKS) { 3034 /* 3035 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds 3036 * the allocation is high priority and these type of 3037 * allocations are system rather than user orientated 3038 */ 3039 ac->zonelist = node_zonelist(numa_node_id(), gfp_mask); 3040 3041 page = __alloc_pages_high_priority(gfp_mask, order, ac); 3042 3043 if (page) { 3044 goto got_pg; 3045 } 3046 } 3047 3048 /* Atomic allocations - we can't balance anything */ 3049 if (!wait) { 3050 /* 3051 * All existing users of the deprecated __GFP_NOFAIL are 3052 * blockable, so warn of any new users that actually allow this 3053 * type of allocation to fail. 3054 */ 3055 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL); 3056 goto nopage; 3057 } 3058 3059 /* Avoid recursion of direct reclaim */ 3060 if (current->flags & PF_MEMALLOC) 3061 goto nopage; 3062 3063 /* Avoid allocations with no watermarks from looping endlessly */ 3064 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL)) 3065 goto nopage; 3066 3067 /* 3068 * Try direct compaction. The first pass is asynchronous. Subsequent 3069 * attempts after direct reclaim are synchronous 3070 */ 3071 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac, 3072 migration_mode, 3073 &contended_compaction, 3074 &deferred_compaction); 3075 if (page) 3076 goto got_pg; 3077 3078 /* Checks for THP-specific high-order allocations */ 3079 if ((gfp_mask & GFP_TRANSHUGE) == GFP_TRANSHUGE) { 3080 /* 3081 * If compaction is deferred for high-order allocations, it is 3082 * because sync compaction recently failed. If this is the case 3083 * and the caller requested a THP allocation, we do not want 3084 * to heavily disrupt the system, so we fail the allocation 3085 * instead of entering direct reclaim. 3086 */ 3087 if (deferred_compaction) 3088 goto nopage; 3089 3090 /* 3091 * In all zones where compaction was attempted (and not 3092 * deferred or skipped), lock contention has been detected. 3093 * For THP allocation we do not want to disrupt the others 3094 * so we fallback to base pages instead. 3095 */ 3096 if (contended_compaction == COMPACT_CONTENDED_LOCK) 3097 goto nopage; 3098 3099 /* 3100 * If compaction was aborted due to need_resched(), we do not 3101 * want to further increase allocation latency, unless it is 3102 * khugepaged trying to collapse. 3103 */ 3104 if (contended_compaction == COMPACT_CONTENDED_SCHED 3105 && !(current->flags & PF_KTHREAD)) 3106 goto nopage; 3107 } 3108 3109 /* 3110 * It can become very expensive to allocate transparent hugepages at 3111 * fault, so use asynchronous memory compaction for THP unless it is 3112 * khugepaged trying to collapse. 3113 */ 3114 if ((gfp_mask & GFP_TRANSHUGE) != GFP_TRANSHUGE || 3115 (current->flags & PF_KTHREAD)) 3116 migration_mode = MIGRATE_SYNC_LIGHT; 3117 3118 /* Try direct reclaim and then allocating */ 3119 page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac, 3120 &did_some_progress); 3121 if (page) 3122 goto got_pg; 3123 3124 /* Do not loop if specifically requested */ 3125 if (gfp_mask & __GFP_NORETRY) 3126 goto noretry; 3127 3128 /* Keep reclaiming pages as long as there is reasonable progress */ 3129 pages_reclaimed += did_some_progress; 3130 if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) || 3131 ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) { 3132 /* Wait for some write requests to complete then retry */ 3133 wait_iff_congested(ac->preferred_zone, BLK_RW_ASYNC, HZ/50); 3134 goto retry; 3135 } 3136 3137 /* Reclaim has failed us, start killing things */ 3138 page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress); 3139 if (page) 3140 goto got_pg; 3141 3142 /* Retry as long as the OOM killer is making progress */ 3143 if (did_some_progress) 3144 goto retry; 3145 3146 noretry: 3147 /* 3148 * High-order allocations do not necessarily loop after 3149 * direct reclaim and reclaim/compaction depends on compaction 3150 * being called after reclaim so call directly if necessary 3151 */ 3152 page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, 3153 ac, migration_mode, 3154 &contended_compaction, 3155 &deferred_compaction); 3156 if (page) 3157 goto got_pg; 3158 nopage: 3159 warn_alloc_failed(gfp_mask, order, NULL); 3160 got_pg: 3161 return page; 3162 } 3163 3164 /* 3165 * This is the 'heart' of the zoned buddy allocator. 3166 */ 3167 struct page * 3168 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, 3169 struct zonelist *zonelist, nodemask_t *nodemask) 3170 { 3171 struct zoneref *preferred_zoneref; 3172 struct page *page = NULL; 3173 unsigned int cpuset_mems_cookie; 3174 int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR; 3175 gfp_t alloc_mask; /* The gfp_t that was actually used for allocation */ 3176 struct alloc_context ac = { 3177 .high_zoneidx = gfp_zone(gfp_mask), 3178 .nodemask = nodemask, 3179 .migratetype = gfpflags_to_migratetype(gfp_mask), 3180 }; 3181 3182 gfp_mask &= gfp_allowed_mask; 3183 3184 lockdep_trace_alloc(gfp_mask); 3185 3186 might_sleep_if(gfp_mask & __GFP_WAIT); 3187 3188 if (should_fail_alloc_page(gfp_mask, order)) 3189 return NULL; 3190 3191 /* 3192 * Check the zones suitable for the gfp_mask contain at least one 3193 * valid zone. It's possible to have an empty zonelist as a result 3194 * of __GFP_THISNODE and a memoryless node 3195 */ 3196 if (unlikely(!zonelist->_zonerefs->zone)) 3197 return NULL; 3198 3199 if (IS_ENABLED(CONFIG_CMA) && ac.migratetype == MIGRATE_MOVABLE) 3200 alloc_flags |= ALLOC_CMA; 3201 3202 retry_cpuset: 3203 cpuset_mems_cookie = read_mems_allowed_begin(); 3204 3205 /* We set it here, as __alloc_pages_slowpath might have changed it */ 3206 ac.zonelist = zonelist; 3207 /* The preferred zone is used for statistics later */ 3208 preferred_zoneref = first_zones_zonelist(ac.zonelist, ac.high_zoneidx, 3209 ac.nodemask ? : &cpuset_current_mems_allowed, 3210 &ac.preferred_zone); 3211 if (!ac.preferred_zone) 3212 goto out; 3213 ac.classzone_idx = zonelist_zone_idx(preferred_zoneref); 3214 3215 /* First allocation attempt */ 3216 alloc_mask = gfp_mask|__GFP_HARDWALL; 3217 page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac); 3218 if (unlikely(!page)) { 3219 /* 3220 * Runtime PM, block IO and its error handling path 3221 * can deadlock because I/O on the device might not 3222 * complete. 3223 */ 3224 alloc_mask = memalloc_noio_flags(gfp_mask); 3225 3226 page = __alloc_pages_slowpath(alloc_mask, order, &ac); 3227 } 3228 3229 if (kmemcheck_enabled && page) 3230 kmemcheck_pagealloc_alloc(page, order, gfp_mask); 3231 3232 trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype); 3233 3234 out: 3235 /* 3236 * When updating a task's mems_allowed, it is possible to race with 3237 * parallel threads in such a way that an allocation can fail while 3238 * the mask is being updated. If a page allocation is about to fail, 3239 * check if the cpuset changed during allocation and if so, retry. 3240 */ 3241 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) 3242 goto retry_cpuset; 3243 3244 return page; 3245 } 3246 EXPORT_SYMBOL(__alloc_pages_nodemask); 3247 3248 /* 3249 * Common helper functions. 3250 */ 3251 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 3252 { 3253 struct page *page; 3254 3255 /* 3256 * __get_free_pages() returns a 32-bit address, which cannot represent 3257 * a highmem page 3258 */ 3259 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 3260 3261 page = alloc_pages(gfp_mask, order); 3262 if (!page) 3263 return 0; 3264 return (unsigned long) page_address(page); 3265 } 3266 EXPORT_SYMBOL(__get_free_pages); 3267 3268 unsigned long get_zeroed_page(gfp_t gfp_mask) 3269 { 3270 return __get_free_pages(gfp_mask | __GFP_ZERO, 0); 3271 } 3272 EXPORT_SYMBOL(get_zeroed_page); 3273 3274 void __free_pages(struct page *page, unsigned int order) 3275 { 3276 if (put_page_testzero(page)) { 3277 if (order == 0) 3278 free_hot_cold_page(page, false); 3279 else 3280 __free_pages_ok(page, order); 3281 } 3282 } 3283 3284 EXPORT_SYMBOL(__free_pages); 3285 3286 void free_pages(unsigned long addr, unsigned int order) 3287 { 3288 if (addr != 0) { 3289 VM_BUG_ON(!virt_addr_valid((void *)addr)); 3290 __free_pages(virt_to_page((void *)addr), order); 3291 } 3292 } 3293 3294 EXPORT_SYMBOL(free_pages); 3295 3296 /* 3297 * Page Fragment: 3298 * An arbitrary-length arbitrary-offset area of memory which resides 3299 * within a 0 or higher order page. Multiple fragments within that page 3300 * are individually refcounted, in the page's reference counter. 3301 * 3302 * The page_frag functions below provide a simple allocation framework for 3303 * page fragments. This is used by the network stack and network device 3304 * drivers to provide a backing region of memory for use as either an 3305 * sk_buff->head, or to be used in the "frags" portion of skb_shared_info. 3306 */ 3307 static struct page *__page_frag_refill(struct page_frag_cache *nc, 3308 gfp_t gfp_mask) 3309 { 3310 struct page *page = NULL; 3311 gfp_t gfp = gfp_mask; 3312 3313 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) 3314 gfp_mask |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY | 3315 __GFP_NOMEMALLOC; 3316 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, 3317 PAGE_FRAG_CACHE_MAX_ORDER); 3318 nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE; 3319 #endif 3320 if (unlikely(!page)) 3321 page = alloc_pages_node(NUMA_NO_NODE, gfp, 0); 3322 3323 nc->va = page ? page_address(page) : NULL; 3324 3325 return page; 3326 } 3327 3328 void *__alloc_page_frag(struct page_frag_cache *nc, 3329 unsigned int fragsz, gfp_t gfp_mask) 3330 { 3331 unsigned int size = PAGE_SIZE; 3332 struct page *page; 3333 int offset; 3334 3335 if (unlikely(!nc->va)) { 3336 refill: 3337 page = __page_frag_refill(nc, gfp_mask); 3338 if (!page) 3339 return NULL; 3340 3341 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) 3342 /* if size can vary use size else just use PAGE_SIZE */ 3343 size = nc->size; 3344 #endif 3345 /* Even if we own the page, we do not use atomic_set(). 3346 * This would break get_page_unless_zero() users. 3347 */ 3348 atomic_add(size - 1, &page->_count); 3349 3350 /* reset page count bias and offset to start of new frag */ 3351 nc->pfmemalloc = page_is_pfmemalloc(page); 3352 nc->pagecnt_bias = size; 3353 nc->offset = size; 3354 } 3355 3356 offset = nc->offset - fragsz; 3357 if (unlikely(offset < 0)) { 3358 page = virt_to_page(nc->va); 3359 3360 if (!atomic_sub_and_test(nc->pagecnt_bias, &page->_count)) 3361 goto refill; 3362 3363 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) 3364 /* if size can vary use size else just use PAGE_SIZE */ 3365 size = nc->size; 3366 #endif 3367 /* OK, page count is 0, we can safely set it */ 3368 atomic_set(&page->_count, size); 3369 3370 /* reset page count bias and offset to start of new frag */ 3371 nc->pagecnt_bias = size; 3372 offset = size - fragsz; 3373 } 3374 3375 nc->pagecnt_bias--; 3376 nc->offset = offset; 3377 3378 return nc->va + offset; 3379 } 3380 EXPORT_SYMBOL(__alloc_page_frag); 3381 3382 /* 3383 * Frees a page fragment allocated out of either a compound or order 0 page. 3384 */ 3385 void __free_page_frag(void *addr) 3386 { 3387 struct page *page = virt_to_head_page(addr); 3388 3389 if (unlikely(put_page_testzero(page))) 3390 __free_pages_ok(page, compound_order(page)); 3391 } 3392 EXPORT_SYMBOL(__free_page_frag); 3393 3394 /* 3395 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter 3396 * of the current memory cgroup. 3397 * 3398 * It should be used when the caller would like to use kmalloc, but since the 3399 * allocation is large, it has to fall back to the page allocator. 3400 */ 3401 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order) 3402 { 3403 struct page *page; 3404 struct mem_cgroup *memcg = NULL; 3405 3406 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order)) 3407 return NULL; 3408 page = alloc_pages(gfp_mask, order); 3409 memcg_kmem_commit_charge(page, memcg, order); 3410 return page; 3411 } 3412 3413 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order) 3414 { 3415 struct page *page; 3416 struct mem_cgroup *memcg = NULL; 3417 3418 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order)) 3419 return NULL; 3420 page = alloc_pages_node(nid, gfp_mask, order); 3421 memcg_kmem_commit_charge(page, memcg, order); 3422 return page; 3423 } 3424 3425 /* 3426 * __free_kmem_pages and free_kmem_pages will free pages allocated with 3427 * alloc_kmem_pages. 3428 */ 3429 void __free_kmem_pages(struct page *page, unsigned int order) 3430 { 3431 memcg_kmem_uncharge_pages(page, order); 3432 __free_pages(page, order); 3433 } 3434 3435 void free_kmem_pages(unsigned long addr, unsigned int order) 3436 { 3437 if (addr != 0) { 3438 VM_BUG_ON(!virt_addr_valid((void *)addr)); 3439 __free_kmem_pages(virt_to_page((void *)addr), order); 3440 } 3441 } 3442 3443 static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size) 3444 { 3445 if (addr) { 3446 unsigned long alloc_end = addr + (PAGE_SIZE << order); 3447 unsigned long used = addr + PAGE_ALIGN(size); 3448 3449 split_page(virt_to_page((void *)addr), order); 3450 while (used < alloc_end) { 3451 free_page(used); 3452 used += PAGE_SIZE; 3453 } 3454 } 3455 return (void *)addr; 3456 } 3457 3458 /** 3459 * alloc_pages_exact - allocate an exact number physically-contiguous pages. 3460 * @size: the number of bytes to allocate 3461 * @gfp_mask: GFP flags for the allocation 3462 * 3463 * This function is similar to alloc_pages(), except that it allocates the 3464 * minimum number of pages to satisfy the request. alloc_pages() can only 3465 * allocate memory in power-of-two pages. 3466 * 3467 * This function is also limited by MAX_ORDER. 3468 * 3469 * Memory allocated by this function must be released by free_pages_exact(). 3470 */ 3471 void *alloc_pages_exact(size_t size, gfp_t gfp_mask) 3472 { 3473 unsigned int order = get_order(size); 3474 unsigned long addr; 3475 3476 addr = __get_free_pages(gfp_mask, order); 3477 return make_alloc_exact(addr, order, size); 3478 } 3479 EXPORT_SYMBOL(alloc_pages_exact); 3480 3481 /** 3482 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous 3483 * pages on a node. 3484 * @nid: the preferred node ID where memory should be allocated 3485 * @size: the number of bytes to allocate 3486 * @gfp_mask: GFP flags for the allocation 3487 * 3488 * Like alloc_pages_exact(), but try to allocate on node nid first before falling 3489 * back. 3490 * Note this is not alloc_pages_exact_node() which allocates on a specific node, 3491 * but is not exact. 3492 */ 3493 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask) 3494 { 3495 unsigned order = get_order(size); 3496 struct page *p = alloc_pages_node(nid, gfp_mask, order); 3497 if (!p) 3498 return NULL; 3499 return make_alloc_exact((unsigned long)page_address(p), order, size); 3500 } 3501 3502 /** 3503 * free_pages_exact - release memory allocated via alloc_pages_exact() 3504 * @virt: the value returned by alloc_pages_exact. 3505 * @size: size of allocation, same value as passed to alloc_pages_exact(). 3506 * 3507 * Release the memory allocated by a previous call to alloc_pages_exact. 3508 */ 3509 void free_pages_exact(void *virt, size_t size) 3510 { 3511 unsigned long addr = (unsigned long)virt; 3512 unsigned long end = addr + PAGE_ALIGN(size); 3513 3514 while (addr < end) { 3515 free_page(addr); 3516 addr += PAGE_SIZE; 3517 } 3518 } 3519 EXPORT_SYMBOL(free_pages_exact); 3520 3521 /** 3522 * nr_free_zone_pages - count number of pages beyond high watermark 3523 * @offset: The zone index of the highest zone 3524 * 3525 * nr_free_zone_pages() counts the number of counts pages which are beyond the 3526 * high watermark within all zones at or below a given zone index. For each 3527 * zone, the number of pages is calculated as: 3528 * managed_pages - high_pages 3529 */ 3530 static unsigned long nr_free_zone_pages(int offset) 3531 { 3532 struct zoneref *z; 3533 struct zone *zone; 3534 3535 /* Just pick one node, since fallback list is circular */ 3536 unsigned long sum = 0; 3537 3538 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); 3539 3540 for_each_zone_zonelist(zone, z, zonelist, offset) { 3541 unsigned long size = zone->managed_pages; 3542 unsigned long high = high_wmark_pages(zone); 3543 if (size > high) 3544 sum += size - high; 3545 } 3546 3547 return sum; 3548 } 3549 3550 /** 3551 * nr_free_buffer_pages - count number of pages beyond high watermark 3552 * 3553 * nr_free_buffer_pages() counts the number of pages which are beyond the high 3554 * watermark within ZONE_DMA and ZONE_NORMAL. 3555 */ 3556 unsigned long nr_free_buffer_pages(void) 3557 { 3558 return nr_free_zone_pages(gfp_zone(GFP_USER)); 3559 } 3560 EXPORT_SYMBOL_GPL(nr_free_buffer_pages); 3561 3562 /** 3563 * nr_free_pagecache_pages - count number of pages beyond high watermark 3564 * 3565 * nr_free_pagecache_pages() counts the number of pages which are beyond the 3566 * high watermark within all zones. 3567 */ 3568 unsigned long nr_free_pagecache_pages(void) 3569 { 3570 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); 3571 } 3572 3573 static inline void show_node(struct zone *zone) 3574 { 3575 if (IS_ENABLED(CONFIG_NUMA)) 3576 printk("Node %d ", zone_to_nid(zone)); 3577 } 3578 3579 void si_meminfo(struct sysinfo *val) 3580 { 3581 val->totalram = totalram_pages; 3582 val->sharedram = global_page_state(NR_SHMEM); 3583 val->freeram = global_page_state(NR_FREE_PAGES); 3584 val->bufferram = nr_blockdev_pages(); 3585 val->totalhigh = totalhigh_pages; 3586 val->freehigh = nr_free_highpages(); 3587 val->mem_unit = PAGE_SIZE; 3588 } 3589 3590 EXPORT_SYMBOL(si_meminfo); 3591 3592 #ifdef CONFIG_NUMA 3593 void si_meminfo_node(struct sysinfo *val, int nid) 3594 { 3595 int zone_type; /* needs to be signed */ 3596 unsigned long managed_pages = 0; 3597 pg_data_t *pgdat = NODE_DATA(nid); 3598 3599 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) 3600 managed_pages += pgdat->node_zones[zone_type].managed_pages; 3601 val->totalram = managed_pages; 3602 val->sharedram = node_page_state(nid, NR_SHMEM); 3603 val->freeram = node_page_state(nid, NR_FREE_PAGES); 3604 #ifdef CONFIG_HIGHMEM 3605 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages; 3606 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], 3607 NR_FREE_PAGES); 3608 #else 3609 val->totalhigh = 0; 3610 val->freehigh = 0; 3611 #endif 3612 val->mem_unit = PAGE_SIZE; 3613 } 3614 #endif 3615 3616 /* 3617 * Determine whether the node should be displayed or not, depending on whether 3618 * SHOW_MEM_FILTER_NODES was passed to show_free_areas(). 3619 */ 3620 bool skip_free_areas_node(unsigned int flags, int nid) 3621 { 3622 bool ret = false; 3623 unsigned int cpuset_mems_cookie; 3624 3625 if (!(flags & SHOW_MEM_FILTER_NODES)) 3626 goto out; 3627 3628 do { 3629 cpuset_mems_cookie = read_mems_allowed_begin(); 3630 ret = !node_isset(nid, cpuset_current_mems_allowed); 3631 } while (read_mems_allowed_retry(cpuset_mems_cookie)); 3632 out: 3633 return ret; 3634 } 3635 3636 #define K(x) ((x) << (PAGE_SHIFT-10)) 3637 3638 static void show_migration_types(unsigned char type) 3639 { 3640 static const char types[MIGRATE_TYPES] = { 3641 [MIGRATE_UNMOVABLE] = 'U', 3642 [MIGRATE_RECLAIMABLE] = 'E', 3643 [MIGRATE_MOVABLE] = 'M', 3644 [MIGRATE_RESERVE] = 'R', 3645 #ifdef CONFIG_CMA 3646 [MIGRATE_CMA] = 'C', 3647 #endif 3648 #ifdef CONFIG_MEMORY_ISOLATION 3649 [MIGRATE_ISOLATE] = 'I', 3650 #endif 3651 }; 3652 char tmp[MIGRATE_TYPES + 1]; 3653 char *p = tmp; 3654 int i; 3655 3656 for (i = 0; i < MIGRATE_TYPES; i++) { 3657 if (type & (1 << i)) 3658 *p++ = types[i]; 3659 } 3660 3661 *p = '\0'; 3662 printk("(%s) ", tmp); 3663 } 3664 3665 /* 3666 * Show free area list (used inside shift_scroll-lock stuff) 3667 * We also calculate the percentage fragmentation. We do this by counting the 3668 * memory on each free list with the exception of the first item on the list. 3669 * 3670 * Bits in @filter: 3671 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's 3672 * cpuset. 3673 */ 3674 void show_free_areas(unsigned int filter) 3675 { 3676 unsigned long free_pcp = 0; 3677 int cpu; 3678 struct zone *zone; 3679 3680 for_each_populated_zone(zone) { 3681 if (skip_free_areas_node(filter, zone_to_nid(zone))) 3682 continue; 3683 3684 for_each_online_cpu(cpu) 3685 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count; 3686 } 3687 3688 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n" 3689 " active_file:%lu inactive_file:%lu isolated_file:%lu\n" 3690 " unevictable:%lu dirty:%lu writeback:%lu unstable:%lu\n" 3691 " slab_reclaimable:%lu slab_unreclaimable:%lu\n" 3692 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n" 3693 " free:%lu free_pcp:%lu free_cma:%lu\n", 3694 global_page_state(NR_ACTIVE_ANON), 3695 global_page_state(NR_INACTIVE_ANON), 3696 global_page_state(NR_ISOLATED_ANON), 3697 global_page_state(NR_ACTIVE_FILE), 3698 global_page_state(NR_INACTIVE_FILE), 3699 global_page_state(NR_ISOLATED_FILE), 3700 global_page_state(NR_UNEVICTABLE), 3701 global_page_state(NR_FILE_DIRTY), 3702 global_page_state(NR_WRITEBACK), 3703 global_page_state(NR_UNSTABLE_NFS), 3704 global_page_state(NR_SLAB_RECLAIMABLE), 3705 global_page_state(NR_SLAB_UNRECLAIMABLE), 3706 global_page_state(NR_FILE_MAPPED), 3707 global_page_state(NR_SHMEM), 3708 global_page_state(NR_PAGETABLE), 3709 global_page_state(NR_BOUNCE), 3710 global_page_state(NR_FREE_PAGES), 3711 free_pcp, 3712 global_page_state(NR_FREE_CMA_PAGES)); 3713 3714 for_each_populated_zone(zone) { 3715 int i; 3716 3717 if (skip_free_areas_node(filter, zone_to_nid(zone))) 3718 continue; 3719 3720 free_pcp = 0; 3721 for_each_online_cpu(cpu) 3722 free_pcp += per_cpu_ptr(zone->pageset, cpu)->pcp.count; 3723 3724 show_node(zone); 3725 printk("%s" 3726 " free:%lukB" 3727 " min:%lukB" 3728 " low:%lukB" 3729 " high:%lukB" 3730 " active_anon:%lukB" 3731 " inactive_anon:%lukB" 3732 " active_file:%lukB" 3733 " inactive_file:%lukB" 3734 " unevictable:%lukB" 3735 " isolated(anon):%lukB" 3736 " isolated(file):%lukB" 3737 " present:%lukB" 3738 " managed:%lukB" 3739 " mlocked:%lukB" 3740 " dirty:%lukB" 3741 " writeback:%lukB" 3742 " mapped:%lukB" 3743 " shmem:%lukB" 3744 " slab_reclaimable:%lukB" 3745 " slab_unreclaimable:%lukB" 3746 " kernel_stack:%lukB" 3747 " pagetables:%lukB" 3748 " unstable:%lukB" 3749 " bounce:%lukB" 3750 " free_pcp:%lukB" 3751 " local_pcp:%ukB" 3752 " free_cma:%lukB" 3753 " writeback_tmp:%lukB" 3754 " pages_scanned:%lu" 3755 " all_unreclaimable? %s" 3756 "\n", 3757 zone->name, 3758 K(zone_page_state(zone, NR_FREE_PAGES)), 3759 K(min_wmark_pages(zone)), 3760 K(low_wmark_pages(zone)), 3761 K(high_wmark_pages(zone)), 3762 K(zone_page_state(zone, NR_ACTIVE_ANON)), 3763 K(zone_page_state(zone, NR_INACTIVE_ANON)), 3764 K(zone_page_state(zone, NR_ACTIVE_FILE)), 3765 K(zone_page_state(zone, NR_INACTIVE_FILE)), 3766 K(zone_page_state(zone, NR_UNEVICTABLE)), 3767 K(zone_page_state(zone, NR_ISOLATED_ANON)), 3768 K(zone_page_state(zone, NR_ISOLATED_FILE)), 3769 K(zone->present_pages), 3770 K(zone->managed_pages), 3771 K(zone_page_state(zone, NR_MLOCK)), 3772 K(zone_page_state(zone, NR_FILE_DIRTY)), 3773 K(zone_page_state(zone, NR_WRITEBACK)), 3774 K(zone_page_state(zone, NR_FILE_MAPPED)), 3775 K(zone_page_state(zone, NR_SHMEM)), 3776 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)), 3777 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)), 3778 zone_page_state(zone, NR_KERNEL_STACK) * 3779 THREAD_SIZE / 1024, 3780 K(zone_page_state(zone, NR_PAGETABLE)), 3781 K(zone_page_state(zone, NR_UNSTABLE_NFS)), 3782 K(zone_page_state(zone, NR_BOUNCE)), 3783 K(free_pcp), 3784 K(this_cpu_read(zone->pageset->pcp.count)), 3785 K(zone_page_state(zone, NR_FREE_CMA_PAGES)), 3786 K(zone_page_state(zone, NR_WRITEBACK_TEMP)), 3787 K(zone_page_state(zone, NR_PAGES_SCANNED)), 3788 (!zone_reclaimable(zone) ? "yes" : "no") 3789 ); 3790 printk("lowmem_reserve[]:"); 3791 for (i = 0; i < MAX_NR_ZONES; i++) 3792 printk(" %ld", zone->lowmem_reserve[i]); 3793 printk("\n"); 3794 } 3795 3796 for_each_populated_zone(zone) { 3797 unsigned long nr[MAX_ORDER], flags, order, total = 0; 3798 unsigned char types[MAX_ORDER]; 3799 3800 if (skip_free_areas_node(filter, zone_to_nid(zone))) 3801 continue; 3802 show_node(zone); 3803 printk("%s: ", zone->name); 3804 3805 spin_lock_irqsave(&zone->lock, flags); 3806 for (order = 0; order < MAX_ORDER; order++) { 3807 struct free_area *area = &zone->free_area[order]; 3808 int type; 3809 3810 nr[order] = area->nr_free; 3811 total += nr[order] << order; 3812 3813 types[order] = 0; 3814 for (type = 0; type < MIGRATE_TYPES; type++) { 3815 if (!list_empty(&area->free_list[type])) 3816 types[order] |= 1 << type; 3817 } 3818 } 3819 spin_unlock_irqrestore(&zone->lock, flags); 3820 for (order = 0; order < MAX_ORDER; order++) { 3821 printk("%lu*%lukB ", nr[order], K(1UL) << order); 3822 if (nr[order]) 3823 show_migration_types(types[order]); 3824 } 3825 printk("= %lukB\n", K(total)); 3826 } 3827 3828 hugetlb_show_meminfo(); 3829 3830 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES)); 3831 3832 show_swap_cache_info(); 3833 } 3834 3835 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) 3836 { 3837 zoneref->zone = zone; 3838 zoneref->zone_idx = zone_idx(zone); 3839 } 3840 3841 /* 3842 * Builds allocation fallback zone lists. 3843 * 3844 * Add all populated zones of a node to the zonelist. 3845 */ 3846 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, 3847 int nr_zones) 3848 { 3849 struct zone *zone; 3850 enum zone_type zone_type = MAX_NR_ZONES; 3851 3852 do { 3853 zone_type--; 3854 zone = pgdat->node_zones + zone_type; 3855 if (populated_zone(zone)) { 3856 zoneref_set_zone(zone, 3857 &zonelist->_zonerefs[nr_zones++]); 3858 check_highest_zone(zone_type); 3859 } 3860 } while (zone_type); 3861 3862 return nr_zones; 3863 } 3864 3865 3866 /* 3867 * zonelist_order: 3868 * 0 = automatic detection of better ordering. 3869 * 1 = order by ([node] distance, -zonetype) 3870 * 2 = order by (-zonetype, [node] distance) 3871 * 3872 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create 3873 * the same zonelist. So only NUMA can configure this param. 3874 */ 3875 #define ZONELIST_ORDER_DEFAULT 0 3876 #define ZONELIST_ORDER_NODE 1 3877 #define ZONELIST_ORDER_ZONE 2 3878 3879 /* zonelist order in the kernel. 3880 * set_zonelist_order() will set this to NODE or ZONE. 3881 */ 3882 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT; 3883 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"}; 3884 3885 3886 #ifdef CONFIG_NUMA 3887 /* The value user specified ....changed by config */ 3888 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT; 3889 /* string for sysctl */ 3890 #define NUMA_ZONELIST_ORDER_LEN 16 3891 char numa_zonelist_order[16] = "default"; 3892 3893 /* 3894 * interface for configure zonelist ordering. 3895 * command line option "numa_zonelist_order" 3896 * = "[dD]efault - default, automatic configuration. 3897 * = "[nN]ode - order by node locality, then by zone within node 3898 * = "[zZ]one - order by zone, then by locality within zone 3899 */ 3900 3901 static int __parse_numa_zonelist_order(char *s) 3902 { 3903 if (*s == 'd' || *s == 'D') { 3904 user_zonelist_order = ZONELIST_ORDER_DEFAULT; 3905 } else if (*s == 'n' || *s == 'N') { 3906 user_zonelist_order = ZONELIST_ORDER_NODE; 3907 } else if (*s == 'z' || *s == 'Z') { 3908 user_zonelist_order = ZONELIST_ORDER_ZONE; 3909 } else { 3910 printk(KERN_WARNING 3911 "Ignoring invalid numa_zonelist_order value: " 3912 "%s\n", s); 3913 return -EINVAL; 3914 } 3915 return 0; 3916 } 3917 3918 static __init int setup_numa_zonelist_order(char *s) 3919 { 3920 int ret; 3921 3922 if (!s) 3923 return 0; 3924 3925 ret = __parse_numa_zonelist_order(s); 3926 if (ret == 0) 3927 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN); 3928 3929 return ret; 3930 } 3931 early_param("numa_zonelist_order", setup_numa_zonelist_order); 3932 3933 /* 3934 * sysctl handler for numa_zonelist_order 3935 */ 3936 int numa_zonelist_order_handler(struct ctl_table *table, int write, 3937 void __user *buffer, size_t *length, 3938 loff_t *ppos) 3939 { 3940 char saved_string[NUMA_ZONELIST_ORDER_LEN]; 3941 int ret; 3942 static DEFINE_MUTEX(zl_order_mutex); 3943 3944 mutex_lock(&zl_order_mutex); 3945 if (write) { 3946 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) { 3947 ret = -EINVAL; 3948 goto out; 3949 } 3950 strcpy(saved_string, (char *)table->data); 3951 } 3952 ret = proc_dostring(table, write, buffer, length, ppos); 3953 if (ret) 3954 goto out; 3955 if (write) { 3956 int oldval = user_zonelist_order; 3957 3958 ret = __parse_numa_zonelist_order((char *)table->data); 3959 if (ret) { 3960 /* 3961 * bogus value. restore saved string 3962 */ 3963 strncpy((char *)table->data, saved_string, 3964 NUMA_ZONELIST_ORDER_LEN); 3965 user_zonelist_order = oldval; 3966 } else if (oldval != user_zonelist_order) { 3967 mutex_lock(&zonelists_mutex); 3968 build_all_zonelists(NULL, NULL); 3969 mutex_unlock(&zonelists_mutex); 3970 } 3971 } 3972 out: 3973 mutex_unlock(&zl_order_mutex); 3974 return ret; 3975 } 3976 3977 3978 #define MAX_NODE_LOAD (nr_online_nodes) 3979 static int node_load[MAX_NUMNODES]; 3980 3981 /** 3982 * find_next_best_node - find the next node that should appear in a given node's fallback list 3983 * @node: node whose fallback list we're appending 3984 * @used_node_mask: nodemask_t of already used nodes 3985 * 3986 * We use a number of factors to determine which is the next node that should 3987 * appear on a given node's fallback list. The node should not have appeared 3988 * already in @node's fallback list, and it should be the next closest node 3989 * according to the distance array (which contains arbitrary distance values 3990 * from each node to each node in the system), and should also prefer nodes 3991 * with no CPUs, since presumably they'll have very little allocation pressure 3992 * on them otherwise. 3993 * It returns -1 if no node is found. 3994 */ 3995 static int find_next_best_node(int node, nodemask_t *used_node_mask) 3996 { 3997 int n, val; 3998 int min_val = INT_MAX; 3999 int best_node = NUMA_NO_NODE; 4000 const struct cpumask *tmp = cpumask_of_node(0); 4001 4002 /* Use the local node if we haven't already */ 4003 if (!node_isset(node, *used_node_mask)) { 4004 node_set(node, *used_node_mask); 4005 return node; 4006 } 4007 4008 for_each_node_state(n, N_MEMORY) { 4009 4010 /* Don't want a node to appear more than once */ 4011 if (node_isset(n, *used_node_mask)) 4012 continue; 4013 4014 /* Use the distance array to find the distance */ 4015 val = node_distance(node, n); 4016 4017 /* Penalize nodes under us ("prefer the next node") */ 4018 val += (n < node); 4019 4020 /* Give preference to headless and unused nodes */ 4021 tmp = cpumask_of_node(n); 4022 if (!cpumask_empty(tmp)) 4023 val += PENALTY_FOR_NODE_WITH_CPUS; 4024 4025 /* Slight preference for less loaded node */ 4026 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 4027 val += node_load[n]; 4028 4029 if (val < min_val) { 4030 min_val = val; 4031 best_node = n; 4032 } 4033 } 4034 4035 if (best_node >= 0) 4036 node_set(best_node, *used_node_mask); 4037 4038 return best_node; 4039 } 4040 4041 4042 /* 4043 * Build zonelists ordered by node and zones within node. 4044 * This results in maximum locality--normal zone overflows into local 4045 * DMA zone, if any--but risks exhausting DMA zone. 4046 */ 4047 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) 4048 { 4049 int j; 4050 struct zonelist *zonelist; 4051 4052 zonelist = &pgdat->node_zonelists[0]; 4053 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++) 4054 ; 4055 j = build_zonelists_node(NODE_DATA(node), zonelist, j); 4056 zonelist->_zonerefs[j].zone = NULL; 4057 zonelist->_zonerefs[j].zone_idx = 0; 4058 } 4059 4060 /* 4061 * Build gfp_thisnode zonelists 4062 */ 4063 static void build_thisnode_zonelists(pg_data_t *pgdat) 4064 { 4065 int j; 4066 struct zonelist *zonelist; 4067 4068 zonelist = &pgdat->node_zonelists[1]; 4069 j = build_zonelists_node(pgdat, zonelist, 0); 4070 zonelist->_zonerefs[j].zone = NULL; 4071 zonelist->_zonerefs[j].zone_idx = 0; 4072 } 4073 4074 /* 4075 * Build zonelists ordered by zone and nodes within zones. 4076 * This results in conserving DMA zone[s] until all Normal memory is 4077 * exhausted, but results in overflowing to remote node while memory 4078 * may still exist in local DMA zone. 4079 */ 4080 static int node_order[MAX_NUMNODES]; 4081 4082 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) 4083 { 4084 int pos, j, node; 4085 int zone_type; /* needs to be signed */ 4086 struct zone *z; 4087 struct zonelist *zonelist; 4088 4089 zonelist = &pgdat->node_zonelists[0]; 4090 pos = 0; 4091 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) { 4092 for (j = 0; j < nr_nodes; j++) { 4093 node = node_order[j]; 4094 z = &NODE_DATA(node)->node_zones[zone_type]; 4095 if (populated_zone(z)) { 4096 zoneref_set_zone(z, 4097 &zonelist->_zonerefs[pos++]); 4098 check_highest_zone(zone_type); 4099 } 4100 } 4101 } 4102 zonelist->_zonerefs[pos].zone = NULL; 4103 zonelist->_zonerefs[pos].zone_idx = 0; 4104 } 4105 4106 #if defined(CONFIG_64BIT) 4107 /* 4108 * Devices that require DMA32/DMA are relatively rare and do not justify a 4109 * penalty to every machine in case the specialised case applies. Default 4110 * to Node-ordering on 64-bit NUMA machines 4111 */ 4112 static int default_zonelist_order(void) 4113 { 4114 return ZONELIST_ORDER_NODE; 4115 } 4116 #else 4117 /* 4118 * On 32-bit, the Normal zone needs to be preserved for allocations accessible 4119 * by the kernel. If processes running on node 0 deplete the low memory zone 4120 * then reclaim will occur more frequency increasing stalls and potentially 4121 * be easier to OOM if a large percentage of the zone is under writeback or 4122 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set. 4123 * Hence, default to zone ordering on 32-bit. 4124 */ 4125 static int default_zonelist_order(void) 4126 { 4127 return ZONELIST_ORDER_ZONE; 4128 } 4129 #endif /* CONFIG_64BIT */ 4130 4131 static void set_zonelist_order(void) 4132 { 4133 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT) 4134 current_zonelist_order = default_zonelist_order(); 4135 else 4136 current_zonelist_order = user_zonelist_order; 4137 } 4138 4139 static void build_zonelists(pg_data_t *pgdat) 4140 { 4141 int j, node, load; 4142 enum zone_type i; 4143 nodemask_t used_mask; 4144 int local_node, prev_node; 4145 struct zonelist *zonelist; 4146 int order = current_zonelist_order; 4147 4148 /* initialize zonelists */ 4149 for (i = 0; i < MAX_ZONELISTS; i++) { 4150 zonelist = pgdat->node_zonelists + i; 4151 zonelist->_zonerefs[0].zone = NULL; 4152 zonelist->_zonerefs[0].zone_idx = 0; 4153 } 4154 4155 /* NUMA-aware ordering of nodes */ 4156 local_node = pgdat->node_id; 4157 load = nr_online_nodes; 4158 prev_node = local_node; 4159 nodes_clear(used_mask); 4160 4161 memset(node_order, 0, sizeof(node_order)); 4162 j = 0; 4163 4164 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 4165 /* 4166 * We don't want to pressure a particular node. 4167 * So adding penalty to the first node in same 4168 * distance group to make it round-robin. 4169 */ 4170 if (node_distance(local_node, node) != 4171 node_distance(local_node, prev_node)) 4172 node_load[node] = load; 4173 4174 prev_node = node; 4175 load--; 4176 if (order == ZONELIST_ORDER_NODE) 4177 build_zonelists_in_node_order(pgdat, node); 4178 else 4179 node_order[j++] = node; /* remember order */ 4180 } 4181 4182 if (order == ZONELIST_ORDER_ZONE) { 4183 /* calculate node order -- i.e., DMA last! */ 4184 build_zonelists_in_zone_order(pgdat, j); 4185 } 4186 4187 build_thisnode_zonelists(pgdat); 4188 } 4189 4190 /* Construct the zonelist performance cache - see further mmzone.h */ 4191 static void build_zonelist_cache(pg_data_t *pgdat) 4192 { 4193 struct zonelist *zonelist; 4194 struct zonelist_cache *zlc; 4195 struct zoneref *z; 4196 4197 zonelist = &pgdat->node_zonelists[0]; 4198 zonelist->zlcache_ptr = zlc = &zonelist->zlcache; 4199 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 4200 for (z = zonelist->_zonerefs; z->zone; z++) 4201 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z); 4202 } 4203 4204 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 4205 /* 4206 * Return node id of node used for "local" allocations. 4207 * I.e., first node id of first zone in arg node's generic zonelist. 4208 * Used for initializing percpu 'numa_mem', which is used primarily 4209 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist. 4210 */ 4211 int local_memory_node(int node) 4212 { 4213 struct zone *zone; 4214 4215 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL), 4216 gfp_zone(GFP_KERNEL), 4217 NULL, 4218 &zone); 4219 return zone->node; 4220 } 4221 #endif 4222 4223 #else /* CONFIG_NUMA */ 4224 4225 static void set_zonelist_order(void) 4226 { 4227 current_zonelist_order = ZONELIST_ORDER_ZONE; 4228 } 4229 4230 static void build_zonelists(pg_data_t *pgdat) 4231 { 4232 int node, local_node; 4233 enum zone_type j; 4234 struct zonelist *zonelist; 4235 4236 local_node = pgdat->node_id; 4237 4238 zonelist = &pgdat->node_zonelists[0]; 4239 j = build_zonelists_node(pgdat, zonelist, 0); 4240 4241 /* 4242 * Now we build the zonelist so that it contains the zones 4243 * of all the other nodes. 4244 * We don't want to pressure a particular node, so when 4245 * building the zones for node N, we make sure that the 4246 * zones coming right after the local ones are those from 4247 * node N+1 (modulo N) 4248 */ 4249 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 4250 if (!node_online(node)) 4251 continue; 4252 j = build_zonelists_node(NODE_DATA(node), zonelist, j); 4253 } 4254 for (node = 0; node < local_node; node++) { 4255 if (!node_online(node)) 4256 continue; 4257 j = build_zonelists_node(NODE_DATA(node), zonelist, j); 4258 } 4259 4260 zonelist->_zonerefs[j].zone = NULL; 4261 zonelist->_zonerefs[j].zone_idx = 0; 4262 } 4263 4264 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ 4265 static void build_zonelist_cache(pg_data_t *pgdat) 4266 { 4267 pgdat->node_zonelists[0].zlcache_ptr = NULL; 4268 } 4269 4270 #endif /* CONFIG_NUMA */ 4271 4272 /* 4273 * Boot pageset table. One per cpu which is going to be used for all 4274 * zones and all nodes. The parameters will be set in such a way 4275 * that an item put on a list will immediately be handed over to 4276 * the buddy list. This is safe since pageset manipulation is done 4277 * with interrupts disabled. 4278 * 4279 * The boot_pagesets must be kept even after bootup is complete for 4280 * unused processors and/or zones. They do play a role for bootstrapping 4281 * hotplugged processors. 4282 * 4283 * zoneinfo_show() and maybe other functions do 4284 * not check if the processor is online before following the pageset pointer. 4285 * Other parts of the kernel may not check if the zone is available. 4286 */ 4287 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch); 4288 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset); 4289 static void setup_zone_pageset(struct zone *zone); 4290 4291 /* 4292 * Global mutex to protect against size modification of zonelists 4293 * as well as to serialize pageset setup for the new populated zone. 4294 */ 4295 DEFINE_MUTEX(zonelists_mutex); 4296 4297 /* return values int ....just for stop_machine() */ 4298 static int __build_all_zonelists(void *data) 4299 { 4300 int nid; 4301 int cpu; 4302 pg_data_t *self = data; 4303 4304 #ifdef CONFIG_NUMA 4305 memset(node_load, 0, sizeof(node_load)); 4306 #endif 4307 4308 if (self && !node_online(self->node_id)) { 4309 build_zonelists(self); 4310 build_zonelist_cache(self); 4311 } 4312 4313 for_each_online_node(nid) { 4314 pg_data_t *pgdat = NODE_DATA(nid); 4315 4316 build_zonelists(pgdat); 4317 build_zonelist_cache(pgdat); 4318 } 4319 4320 /* 4321 * Initialize the boot_pagesets that are going to be used 4322 * for bootstrapping processors. The real pagesets for 4323 * each zone will be allocated later when the per cpu 4324 * allocator is available. 4325 * 4326 * boot_pagesets are used also for bootstrapping offline 4327 * cpus if the system is already booted because the pagesets 4328 * are needed to initialize allocators on a specific cpu too. 4329 * F.e. the percpu allocator needs the page allocator which 4330 * needs the percpu allocator in order to allocate its pagesets 4331 * (a chicken-egg dilemma). 4332 */ 4333 for_each_possible_cpu(cpu) { 4334 setup_pageset(&per_cpu(boot_pageset, cpu), 0); 4335 4336 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 4337 /* 4338 * We now know the "local memory node" for each node-- 4339 * i.e., the node of the first zone in the generic zonelist. 4340 * Set up numa_mem percpu variable for on-line cpus. During 4341 * boot, only the boot cpu should be on-line; we'll init the 4342 * secondary cpus' numa_mem as they come on-line. During 4343 * node/memory hotplug, we'll fixup all on-line cpus. 4344 */ 4345 if (cpu_online(cpu)) 4346 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu))); 4347 #endif 4348 } 4349 4350 return 0; 4351 } 4352 4353 static noinline void __init 4354 build_all_zonelists_init(void) 4355 { 4356 __build_all_zonelists(NULL); 4357 mminit_verify_zonelist(); 4358 cpuset_init_current_mems_allowed(); 4359 } 4360 4361 /* 4362 * Called with zonelists_mutex held always 4363 * unless system_state == SYSTEM_BOOTING. 4364 * 4365 * __ref due to (1) call of __meminit annotated setup_zone_pageset 4366 * [we're only called with non-NULL zone through __meminit paths] and 4367 * (2) call of __init annotated helper build_all_zonelists_init 4368 * [protected by SYSTEM_BOOTING]. 4369 */ 4370 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone) 4371 { 4372 set_zonelist_order(); 4373 4374 if (system_state == SYSTEM_BOOTING) { 4375 build_all_zonelists_init(); 4376 } else { 4377 #ifdef CONFIG_MEMORY_HOTPLUG 4378 if (zone) 4379 setup_zone_pageset(zone); 4380 #endif 4381 /* we have to stop all cpus to guarantee there is no user 4382 of zonelist */ 4383 stop_machine(__build_all_zonelists, pgdat, NULL); 4384 /* cpuset refresh routine should be here */ 4385 } 4386 vm_total_pages = nr_free_pagecache_pages(); 4387 /* 4388 * Disable grouping by mobility if the number of pages in the 4389 * system is too low to allow the mechanism to work. It would be 4390 * more accurate, but expensive to check per-zone. This check is 4391 * made on memory-hotadd so a system can start with mobility 4392 * disabled and enable it later 4393 */ 4394 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) 4395 page_group_by_mobility_disabled = 1; 4396 else 4397 page_group_by_mobility_disabled = 0; 4398 4399 pr_info("Built %i zonelists in %s order, mobility grouping %s. " 4400 "Total pages: %ld\n", 4401 nr_online_nodes, 4402 zonelist_order_name[current_zonelist_order], 4403 page_group_by_mobility_disabled ? "off" : "on", 4404 vm_total_pages); 4405 #ifdef CONFIG_NUMA 4406 pr_info("Policy zone: %s\n", zone_names[policy_zone]); 4407 #endif 4408 } 4409 4410 /* 4411 * Helper functions to size the waitqueue hash table. 4412 * Essentially these want to choose hash table sizes sufficiently 4413 * large so that collisions trying to wait on pages are rare. 4414 * But in fact, the number of active page waitqueues on typical 4415 * systems is ridiculously low, less than 200. So this is even 4416 * conservative, even though it seems large. 4417 * 4418 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 4419 * waitqueues, i.e. the size of the waitq table given the number of pages. 4420 */ 4421 #define PAGES_PER_WAITQUEUE 256 4422 4423 #ifndef CONFIG_MEMORY_HOTPLUG 4424 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 4425 { 4426 unsigned long size = 1; 4427 4428 pages /= PAGES_PER_WAITQUEUE; 4429 4430 while (size < pages) 4431 size <<= 1; 4432 4433 /* 4434 * Once we have dozens or even hundreds of threads sleeping 4435 * on IO we've got bigger problems than wait queue collision. 4436 * Limit the size of the wait table to a reasonable size. 4437 */ 4438 size = min(size, 4096UL); 4439 4440 return max(size, 4UL); 4441 } 4442 #else 4443 /* 4444 * A zone's size might be changed by hot-add, so it is not possible to determine 4445 * a suitable size for its wait_table. So we use the maximum size now. 4446 * 4447 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: 4448 * 4449 * i386 (preemption config) : 4096 x 16 = 64Kbyte. 4450 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. 4451 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. 4452 * 4453 * The maximum entries are prepared when a zone's memory is (512K + 256) pages 4454 * or more by the traditional way. (See above). It equals: 4455 * 4456 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. 4457 * ia64(16K page size) : = ( 8G + 4M)byte. 4458 * powerpc (64K page size) : = (32G +16M)byte. 4459 */ 4460 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 4461 { 4462 return 4096UL; 4463 } 4464 #endif 4465 4466 /* 4467 * This is an integer logarithm so that shifts can be used later 4468 * to extract the more random high bits from the multiplicative 4469 * hash function before the remainder is taken. 4470 */ 4471 static inline unsigned long wait_table_bits(unsigned long size) 4472 { 4473 return ffz(~size); 4474 } 4475 4476 /* 4477 * Check if a pageblock contains reserved pages 4478 */ 4479 static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn) 4480 { 4481 unsigned long pfn; 4482 4483 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 4484 if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn))) 4485 return 1; 4486 } 4487 return 0; 4488 } 4489 4490 /* 4491 * Mark a number of pageblocks as MIGRATE_RESERVE. The number 4492 * of blocks reserved is based on min_wmark_pages(zone). The memory within 4493 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes 4494 * higher will lead to a bigger reserve which will get freed as contiguous 4495 * blocks as reclaim kicks in 4496 */ 4497 static void setup_zone_migrate_reserve(struct zone *zone) 4498 { 4499 unsigned long start_pfn, pfn, end_pfn, block_end_pfn; 4500 struct page *page; 4501 unsigned long block_migratetype; 4502 int reserve; 4503 int old_reserve; 4504 4505 /* 4506 * Get the start pfn, end pfn and the number of blocks to reserve 4507 * We have to be careful to be aligned to pageblock_nr_pages to 4508 * make sure that we always check pfn_valid for the first page in 4509 * the block. 4510 */ 4511 start_pfn = zone->zone_start_pfn; 4512 end_pfn = zone_end_pfn(zone); 4513 start_pfn = roundup(start_pfn, pageblock_nr_pages); 4514 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >> 4515 pageblock_order; 4516 4517 /* 4518 * Reserve blocks are generally in place to help high-order atomic 4519 * allocations that are short-lived. A min_free_kbytes value that 4520 * would result in more than 2 reserve blocks for atomic allocations 4521 * is assumed to be in place to help anti-fragmentation for the 4522 * future allocation of hugepages at runtime. 4523 */ 4524 reserve = min(2, reserve); 4525 old_reserve = zone->nr_migrate_reserve_block; 4526 4527 /* When memory hot-add, we almost always need to do nothing */ 4528 if (reserve == old_reserve) 4529 return; 4530 zone->nr_migrate_reserve_block = reserve; 4531 4532 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 4533 if (!early_page_nid_uninitialised(pfn, zone_to_nid(zone))) 4534 return; 4535 4536 if (!pfn_valid(pfn)) 4537 continue; 4538 page = pfn_to_page(pfn); 4539 4540 /* Watch out for overlapping nodes */ 4541 if (page_to_nid(page) != zone_to_nid(zone)) 4542 continue; 4543 4544 block_migratetype = get_pageblock_migratetype(page); 4545 4546 /* Only test what is necessary when the reserves are not met */ 4547 if (reserve > 0) { 4548 /* 4549 * Blocks with reserved pages will never free, skip 4550 * them. 4551 */ 4552 block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn); 4553 if (pageblock_is_reserved(pfn, block_end_pfn)) 4554 continue; 4555 4556 /* If this block is reserved, account for it */ 4557 if (block_migratetype == MIGRATE_RESERVE) { 4558 reserve--; 4559 continue; 4560 } 4561 4562 /* Suitable for reserving if this block is movable */ 4563 if (block_migratetype == MIGRATE_MOVABLE) { 4564 set_pageblock_migratetype(page, 4565 MIGRATE_RESERVE); 4566 move_freepages_block(zone, page, 4567 MIGRATE_RESERVE); 4568 reserve--; 4569 continue; 4570 } 4571 } else if (!old_reserve) { 4572 /* 4573 * At boot time we don't need to scan the whole zone 4574 * for turning off MIGRATE_RESERVE. 4575 */ 4576 break; 4577 } 4578 4579 /* 4580 * If the reserve is met and this is a previous reserved block, 4581 * take it back 4582 */ 4583 if (block_migratetype == MIGRATE_RESERVE) { 4584 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 4585 move_freepages_block(zone, page, MIGRATE_MOVABLE); 4586 } 4587 } 4588 } 4589 4590 /* 4591 * Initially all pages are reserved - free ones are freed 4592 * up by free_all_bootmem() once the early boot process is 4593 * done. Non-atomic initialization, single-pass. 4594 */ 4595 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 4596 unsigned long start_pfn, enum memmap_context context) 4597 { 4598 pg_data_t *pgdat = NODE_DATA(nid); 4599 unsigned long end_pfn = start_pfn + size; 4600 unsigned long pfn; 4601 struct zone *z; 4602 unsigned long nr_initialised = 0; 4603 4604 if (highest_memmap_pfn < end_pfn - 1) 4605 highest_memmap_pfn = end_pfn - 1; 4606 4607 z = &pgdat->node_zones[zone]; 4608 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 4609 /* 4610 * There can be holes in boot-time mem_map[]s 4611 * handed to this function. They do not 4612 * exist on hotplugged memory. 4613 */ 4614 if (context == MEMMAP_EARLY) { 4615 if (!early_pfn_valid(pfn)) 4616 continue; 4617 if (!early_pfn_in_nid(pfn, nid)) 4618 continue; 4619 if (!update_defer_init(pgdat, pfn, end_pfn, 4620 &nr_initialised)) 4621 break; 4622 } 4623 4624 /* 4625 * Mark the block movable so that blocks are reserved for 4626 * movable at startup. This will force kernel allocations 4627 * to reserve their blocks rather than leaking throughout 4628 * the address space during boot when many long-lived 4629 * kernel allocations are made. Later some blocks near 4630 * the start are marked MIGRATE_RESERVE by 4631 * setup_zone_migrate_reserve() 4632 * 4633 * bitmap is created for zone's valid pfn range. but memmap 4634 * can be created for invalid pages (for alignment) 4635 * check here not to call set_pageblock_migratetype() against 4636 * pfn out of zone. 4637 */ 4638 if (!(pfn & (pageblock_nr_pages - 1))) { 4639 struct page *page = pfn_to_page(pfn); 4640 4641 __init_single_page(page, pfn, zone, nid); 4642 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 4643 } else { 4644 __init_single_pfn(pfn, zone, nid); 4645 } 4646 } 4647 } 4648 4649 static void __meminit zone_init_free_lists(struct zone *zone) 4650 { 4651 unsigned int order, t; 4652 for_each_migratetype_order(order, t) { 4653 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); 4654 zone->free_area[order].nr_free = 0; 4655 } 4656 } 4657 4658 #ifndef __HAVE_ARCH_MEMMAP_INIT 4659 #define memmap_init(size, nid, zone, start_pfn) \ 4660 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) 4661 #endif 4662 4663 static int zone_batchsize(struct zone *zone) 4664 { 4665 #ifdef CONFIG_MMU 4666 int batch; 4667 4668 /* 4669 * The per-cpu-pages pools are set to around 1000th of the 4670 * size of the zone. But no more than 1/2 of a meg. 4671 * 4672 * OK, so we don't know how big the cache is. So guess. 4673 */ 4674 batch = zone->managed_pages / 1024; 4675 if (batch * PAGE_SIZE > 512 * 1024) 4676 batch = (512 * 1024) / PAGE_SIZE; 4677 batch /= 4; /* We effectively *= 4 below */ 4678 if (batch < 1) 4679 batch = 1; 4680 4681 /* 4682 * Clamp the batch to a 2^n - 1 value. Having a power 4683 * of 2 value was found to be more likely to have 4684 * suboptimal cache aliasing properties in some cases. 4685 * 4686 * For example if 2 tasks are alternately allocating 4687 * batches of pages, one task can end up with a lot 4688 * of pages of one half of the possible page colors 4689 * and the other with pages of the other colors. 4690 */ 4691 batch = rounddown_pow_of_two(batch + batch/2) - 1; 4692 4693 return batch; 4694 4695 #else 4696 /* The deferral and batching of frees should be suppressed under NOMMU 4697 * conditions. 4698 * 4699 * The problem is that NOMMU needs to be able to allocate large chunks 4700 * of contiguous memory as there's no hardware page translation to 4701 * assemble apparent contiguous memory from discontiguous pages. 4702 * 4703 * Queueing large contiguous runs of pages for batching, however, 4704 * causes the pages to actually be freed in smaller chunks. As there 4705 * can be a significant delay between the individual batches being 4706 * recycled, this leads to the once large chunks of space being 4707 * fragmented and becoming unavailable for high-order allocations. 4708 */ 4709 return 0; 4710 #endif 4711 } 4712 4713 /* 4714 * pcp->high and pcp->batch values are related and dependent on one another: 4715 * ->batch must never be higher then ->high. 4716 * The following function updates them in a safe manner without read side 4717 * locking. 4718 * 4719 * Any new users of pcp->batch and pcp->high should ensure they can cope with 4720 * those fields changing asynchronously (acording the the above rule). 4721 * 4722 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function 4723 * outside of boot time (or some other assurance that no concurrent updaters 4724 * exist). 4725 */ 4726 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high, 4727 unsigned long batch) 4728 { 4729 /* start with a fail safe value for batch */ 4730 pcp->batch = 1; 4731 smp_wmb(); 4732 4733 /* Update high, then batch, in order */ 4734 pcp->high = high; 4735 smp_wmb(); 4736 4737 pcp->batch = batch; 4738 } 4739 4740 /* a companion to pageset_set_high() */ 4741 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch) 4742 { 4743 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch)); 4744 } 4745 4746 static void pageset_init(struct per_cpu_pageset *p) 4747 { 4748 struct per_cpu_pages *pcp; 4749 int migratetype; 4750 4751 memset(p, 0, sizeof(*p)); 4752 4753 pcp = &p->pcp; 4754 pcp->count = 0; 4755 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++) 4756 INIT_LIST_HEAD(&pcp->lists[migratetype]); 4757 } 4758 4759 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 4760 { 4761 pageset_init(p); 4762 pageset_set_batch(p, batch); 4763 } 4764 4765 /* 4766 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist 4767 * to the value high for the pageset p. 4768 */ 4769 static void pageset_set_high(struct per_cpu_pageset *p, 4770 unsigned long high) 4771 { 4772 unsigned long batch = max(1UL, high / 4); 4773 if ((high / 4) > (PAGE_SHIFT * 8)) 4774 batch = PAGE_SHIFT * 8; 4775 4776 pageset_update(&p->pcp, high, batch); 4777 } 4778 4779 static void pageset_set_high_and_batch(struct zone *zone, 4780 struct per_cpu_pageset *pcp) 4781 { 4782 if (percpu_pagelist_fraction) 4783 pageset_set_high(pcp, 4784 (zone->managed_pages / 4785 percpu_pagelist_fraction)); 4786 else 4787 pageset_set_batch(pcp, zone_batchsize(zone)); 4788 } 4789 4790 static void __meminit zone_pageset_init(struct zone *zone, int cpu) 4791 { 4792 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu); 4793 4794 pageset_init(pcp); 4795 pageset_set_high_and_batch(zone, pcp); 4796 } 4797 4798 static void __meminit setup_zone_pageset(struct zone *zone) 4799 { 4800 int cpu; 4801 zone->pageset = alloc_percpu(struct per_cpu_pageset); 4802 for_each_possible_cpu(cpu) 4803 zone_pageset_init(zone, cpu); 4804 } 4805 4806 /* 4807 * Allocate per cpu pagesets and initialize them. 4808 * Before this call only boot pagesets were available. 4809 */ 4810 void __init setup_per_cpu_pageset(void) 4811 { 4812 struct zone *zone; 4813 4814 for_each_populated_zone(zone) 4815 setup_zone_pageset(zone); 4816 } 4817 4818 static noinline __init_refok 4819 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 4820 { 4821 int i; 4822 size_t alloc_size; 4823 4824 /* 4825 * The per-page waitqueue mechanism uses hashed waitqueues 4826 * per zone. 4827 */ 4828 zone->wait_table_hash_nr_entries = 4829 wait_table_hash_nr_entries(zone_size_pages); 4830 zone->wait_table_bits = 4831 wait_table_bits(zone->wait_table_hash_nr_entries); 4832 alloc_size = zone->wait_table_hash_nr_entries 4833 * sizeof(wait_queue_head_t); 4834 4835 if (!slab_is_available()) { 4836 zone->wait_table = (wait_queue_head_t *) 4837 memblock_virt_alloc_node_nopanic( 4838 alloc_size, zone->zone_pgdat->node_id); 4839 } else { 4840 /* 4841 * This case means that a zone whose size was 0 gets new memory 4842 * via memory hot-add. 4843 * But it may be the case that a new node was hot-added. In 4844 * this case vmalloc() will not be able to use this new node's 4845 * memory - this wait_table must be initialized to use this new 4846 * node itself as well. 4847 * To use this new node's memory, further consideration will be 4848 * necessary. 4849 */ 4850 zone->wait_table = vmalloc(alloc_size); 4851 } 4852 if (!zone->wait_table) 4853 return -ENOMEM; 4854 4855 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i) 4856 init_waitqueue_head(zone->wait_table + i); 4857 4858 return 0; 4859 } 4860 4861 static __meminit void zone_pcp_init(struct zone *zone) 4862 { 4863 /* 4864 * per cpu subsystem is not up at this point. The following code 4865 * relies on the ability of the linker to provide the 4866 * offset of a (static) per cpu variable into the per cpu area. 4867 */ 4868 zone->pageset = &boot_pageset; 4869 4870 if (populated_zone(zone)) 4871 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n", 4872 zone->name, zone->present_pages, 4873 zone_batchsize(zone)); 4874 } 4875 4876 int __meminit init_currently_empty_zone(struct zone *zone, 4877 unsigned long zone_start_pfn, 4878 unsigned long size, 4879 enum memmap_context context) 4880 { 4881 struct pglist_data *pgdat = zone->zone_pgdat; 4882 int ret; 4883 ret = zone_wait_table_init(zone, size); 4884 if (ret) 4885 return ret; 4886 pgdat->nr_zones = zone_idx(zone) + 1; 4887 4888 zone->zone_start_pfn = zone_start_pfn; 4889 4890 mminit_dprintk(MMINIT_TRACE, "memmap_init", 4891 "Initialising map node %d zone %lu pfns %lu -> %lu\n", 4892 pgdat->node_id, 4893 (unsigned long)zone_idx(zone), 4894 zone_start_pfn, (zone_start_pfn + size)); 4895 4896 zone_init_free_lists(zone); 4897 4898 return 0; 4899 } 4900 4901 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 4902 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID 4903 4904 /* 4905 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. 4906 */ 4907 int __meminit __early_pfn_to_nid(unsigned long pfn, 4908 struct mminit_pfnnid_cache *state) 4909 { 4910 unsigned long start_pfn, end_pfn; 4911 int nid; 4912 4913 if (state->last_start <= pfn && pfn < state->last_end) 4914 return state->last_nid; 4915 4916 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn); 4917 if (nid != -1) { 4918 state->last_start = start_pfn; 4919 state->last_end = end_pfn; 4920 state->last_nid = nid; 4921 } 4922 4923 return nid; 4924 } 4925 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ 4926 4927 /** 4928 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range 4929 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. 4930 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid 4931 * 4932 * If an architecture guarantees that all ranges registered contain no holes 4933 * and may be freed, this this function may be used instead of calling 4934 * memblock_free_early_nid() manually. 4935 */ 4936 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn) 4937 { 4938 unsigned long start_pfn, end_pfn; 4939 int i, this_nid; 4940 4941 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) { 4942 start_pfn = min(start_pfn, max_low_pfn); 4943 end_pfn = min(end_pfn, max_low_pfn); 4944 4945 if (start_pfn < end_pfn) 4946 memblock_free_early_nid(PFN_PHYS(start_pfn), 4947 (end_pfn - start_pfn) << PAGE_SHIFT, 4948 this_nid); 4949 } 4950 } 4951 4952 /** 4953 * sparse_memory_present_with_active_regions - Call memory_present for each active range 4954 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. 4955 * 4956 * If an architecture guarantees that all ranges registered contain no holes and may 4957 * be freed, this function may be used instead of calling memory_present() manually. 4958 */ 4959 void __init sparse_memory_present_with_active_regions(int nid) 4960 { 4961 unsigned long start_pfn, end_pfn; 4962 int i, this_nid; 4963 4964 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) 4965 memory_present(this_nid, start_pfn, end_pfn); 4966 } 4967 4968 /** 4969 * get_pfn_range_for_nid - Return the start and end page frames for a node 4970 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. 4971 * @start_pfn: Passed by reference. On return, it will have the node start_pfn. 4972 * @end_pfn: Passed by reference. On return, it will have the node end_pfn. 4973 * 4974 * It returns the start and end page frame of a node based on information 4975 * provided by memblock_set_node(). If called for a node 4976 * with no available memory, a warning is printed and the start and end 4977 * PFNs will be 0. 4978 */ 4979 void __meminit get_pfn_range_for_nid(unsigned int nid, 4980 unsigned long *start_pfn, unsigned long *end_pfn) 4981 { 4982 unsigned long this_start_pfn, this_end_pfn; 4983 int i; 4984 4985 *start_pfn = -1UL; 4986 *end_pfn = 0; 4987 4988 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) { 4989 *start_pfn = min(*start_pfn, this_start_pfn); 4990 *end_pfn = max(*end_pfn, this_end_pfn); 4991 } 4992 4993 if (*start_pfn == -1UL) 4994 *start_pfn = 0; 4995 } 4996 4997 /* 4998 * This finds a zone that can be used for ZONE_MOVABLE pages. The 4999 * assumption is made that zones within a node are ordered in monotonic 5000 * increasing memory addresses so that the "highest" populated zone is used 5001 */ 5002 static void __init find_usable_zone_for_movable(void) 5003 { 5004 int zone_index; 5005 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { 5006 if (zone_index == ZONE_MOVABLE) 5007 continue; 5008 5009 if (arch_zone_highest_possible_pfn[zone_index] > 5010 arch_zone_lowest_possible_pfn[zone_index]) 5011 break; 5012 } 5013 5014 VM_BUG_ON(zone_index == -1); 5015 movable_zone = zone_index; 5016 } 5017 5018 /* 5019 * The zone ranges provided by the architecture do not include ZONE_MOVABLE 5020 * because it is sized independent of architecture. Unlike the other zones, 5021 * the starting point for ZONE_MOVABLE is not fixed. It may be different 5022 * in each node depending on the size of each node and how evenly kernelcore 5023 * is distributed. This helper function adjusts the zone ranges 5024 * provided by the architecture for a given node by using the end of the 5025 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that 5026 * zones within a node are in order of monotonic increases memory addresses 5027 */ 5028 static void __meminit adjust_zone_range_for_zone_movable(int nid, 5029 unsigned long zone_type, 5030 unsigned long node_start_pfn, 5031 unsigned long node_end_pfn, 5032 unsigned long *zone_start_pfn, 5033 unsigned long *zone_end_pfn) 5034 { 5035 /* Only adjust if ZONE_MOVABLE is on this node */ 5036 if (zone_movable_pfn[nid]) { 5037 /* Size ZONE_MOVABLE */ 5038 if (zone_type == ZONE_MOVABLE) { 5039 *zone_start_pfn = zone_movable_pfn[nid]; 5040 *zone_end_pfn = min(node_end_pfn, 5041 arch_zone_highest_possible_pfn[movable_zone]); 5042 5043 /* Adjust for ZONE_MOVABLE starting within this range */ 5044 } else if (*zone_start_pfn < zone_movable_pfn[nid] && 5045 *zone_end_pfn > zone_movable_pfn[nid]) { 5046 *zone_end_pfn = zone_movable_pfn[nid]; 5047 5048 /* Check if this whole range is within ZONE_MOVABLE */ 5049 } else if (*zone_start_pfn >= zone_movable_pfn[nid]) 5050 *zone_start_pfn = *zone_end_pfn; 5051 } 5052 } 5053 5054 /* 5055 * Return the number of pages a zone spans in a node, including holes 5056 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() 5057 */ 5058 static unsigned long __meminit zone_spanned_pages_in_node(int nid, 5059 unsigned long zone_type, 5060 unsigned long node_start_pfn, 5061 unsigned long node_end_pfn, 5062 unsigned long *ignored) 5063 { 5064 unsigned long zone_start_pfn, zone_end_pfn; 5065 5066 /* When hotadd a new node, the node should be empty */ 5067 if (!node_start_pfn && !node_end_pfn) 5068 return 0; 5069 5070 /* Get the start and end of the zone */ 5071 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; 5072 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; 5073 adjust_zone_range_for_zone_movable(nid, zone_type, 5074 node_start_pfn, node_end_pfn, 5075 &zone_start_pfn, &zone_end_pfn); 5076 5077 /* Check that this node has pages within the zone's required range */ 5078 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) 5079 return 0; 5080 5081 /* Move the zone boundaries inside the node if necessary */ 5082 zone_end_pfn = min(zone_end_pfn, node_end_pfn); 5083 zone_start_pfn = max(zone_start_pfn, node_start_pfn); 5084 5085 /* Return the spanned pages */ 5086 return zone_end_pfn - zone_start_pfn; 5087 } 5088 5089 /* 5090 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, 5091 * then all holes in the requested range will be accounted for. 5092 */ 5093 unsigned long __meminit __absent_pages_in_range(int nid, 5094 unsigned long range_start_pfn, 5095 unsigned long range_end_pfn) 5096 { 5097 unsigned long nr_absent = range_end_pfn - range_start_pfn; 5098 unsigned long start_pfn, end_pfn; 5099 int i; 5100 5101 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { 5102 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn); 5103 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn); 5104 nr_absent -= end_pfn - start_pfn; 5105 } 5106 return nr_absent; 5107 } 5108 5109 /** 5110 * absent_pages_in_range - Return number of page frames in holes within a range 5111 * @start_pfn: The start PFN to start searching for holes 5112 * @end_pfn: The end PFN to stop searching for holes 5113 * 5114 * It returns the number of pages frames in memory holes within a range. 5115 */ 5116 unsigned long __init absent_pages_in_range(unsigned long start_pfn, 5117 unsigned long end_pfn) 5118 { 5119 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); 5120 } 5121 5122 /* Return the number of page frames in holes in a zone on a node */ 5123 static unsigned long __meminit zone_absent_pages_in_node(int nid, 5124 unsigned long zone_type, 5125 unsigned long node_start_pfn, 5126 unsigned long node_end_pfn, 5127 unsigned long *ignored) 5128 { 5129 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type]; 5130 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type]; 5131 unsigned long zone_start_pfn, zone_end_pfn; 5132 5133 /* When hotadd a new node, the node should be empty */ 5134 if (!node_start_pfn && !node_end_pfn) 5135 return 0; 5136 5137 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high); 5138 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high); 5139 5140 adjust_zone_range_for_zone_movable(nid, zone_type, 5141 node_start_pfn, node_end_pfn, 5142 &zone_start_pfn, &zone_end_pfn); 5143 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); 5144 } 5145 5146 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 5147 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, 5148 unsigned long zone_type, 5149 unsigned long node_start_pfn, 5150 unsigned long node_end_pfn, 5151 unsigned long *zones_size) 5152 { 5153 return zones_size[zone_type]; 5154 } 5155 5156 static inline unsigned long __meminit zone_absent_pages_in_node(int nid, 5157 unsigned long zone_type, 5158 unsigned long node_start_pfn, 5159 unsigned long node_end_pfn, 5160 unsigned long *zholes_size) 5161 { 5162 if (!zholes_size) 5163 return 0; 5164 5165 return zholes_size[zone_type]; 5166 } 5167 5168 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 5169 5170 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, 5171 unsigned long node_start_pfn, 5172 unsigned long node_end_pfn, 5173 unsigned long *zones_size, 5174 unsigned long *zholes_size) 5175 { 5176 unsigned long realtotalpages = 0, totalpages = 0; 5177 enum zone_type i; 5178 5179 for (i = 0; i < MAX_NR_ZONES; i++) { 5180 struct zone *zone = pgdat->node_zones + i; 5181 unsigned long size, real_size; 5182 5183 size = zone_spanned_pages_in_node(pgdat->node_id, i, 5184 node_start_pfn, 5185 node_end_pfn, 5186 zones_size); 5187 real_size = size - zone_absent_pages_in_node(pgdat->node_id, i, 5188 node_start_pfn, node_end_pfn, 5189 zholes_size); 5190 zone->spanned_pages = size; 5191 zone->present_pages = real_size; 5192 5193 totalpages += size; 5194 realtotalpages += real_size; 5195 } 5196 5197 pgdat->node_spanned_pages = totalpages; 5198 pgdat->node_present_pages = realtotalpages; 5199 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, 5200 realtotalpages); 5201 } 5202 5203 #ifndef CONFIG_SPARSEMEM 5204 /* 5205 * Calculate the size of the zone->blockflags rounded to an unsigned long 5206 * Start by making sure zonesize is a multiple of pageblock_order by rounding 5207 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally 5208 * round what is now in bits to nearest long in bits, then return it in 5209 * bytes. 5210 */ 5211 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize) 5212 { 5213 unsigned long usemapsize; 5214 5215 zonesize += zone_start_pfn & (pageblock_nr_pages-1); 5216 usemapsize = roundup(zonesize, pageblock_nr_pages); 5217 usemapsize = usemapsize >> pageblock_order; 5218 usemapsize *= NR_PAGEBLOCK_BITS; 5219 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); 5220 5221 return usemapsize / 8; 5222 } 5223 5224 static void __init setup_usemap(struct pglist_data *pgdat, 5225 struct zone *zone, 5226 unsigned long zone_start_pfn, 5227 unsigned long zonesize) 5228 { 5229 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize); 5230 zone->pageblock_flags = NULL; 5231 if (usemapsize) 5232 zone->pageblock_flags = 5233 memblock_virt_alloc_node_nopanic(usemapsize, 5234 pgdat->node_id); 5235 } 5236 #else 5237 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone, 5238 unsigned long zone_start_pfn, unsigned long zonesize) {} 5239 #endif /* CONFIG_SPARSEMEM */ 5240 5241 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 5242 5243 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ 5244 void __paginginit set_pageblock_order(void) 5245 { 5246 unsigned int order; 5247 5248 /* Check that pageblock_nr_pages has not already been setup */ 5249 if (pageblock_order) 5250 return; 5251 5252 if (HPAGE_SHIFT > PAGE_SHIFT) 5253 order = HUGETLB_PAGE_ORDER; 5254 else 5255 order = MAX_ORDER - 1; 5256 5257 /* 5258 * Assume the largest contiguous order of interest is a huge page. 5259 * This value may be variable depending on boot parameters on IA64 and 5260 * powerpc. 5261 */ 5262 pageblock_order = order; 5263 } 5264 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 5265 5266 /* 5267 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() 5268 * is unused as pageblock_order is set at compile-time. See 5269 * include/linux/pageblock-flags.h for the values of pageblock_order based on 5270 * the kernel config 5271 */ 5272 void __paginginit set_pageblock_order(void) 5273 { 5274 } 5275 5276 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 5277 5278 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages, 5279 unsigned long present_pages) 5280 { 5281 unsigned long pages = spanned_pages; 5282 5283 /* 5284 * Provide a more accurate estimation if there are holes within 5285 * the zone and SPARSEMEM is in use. If there are holes within the 5286 * zone, each populated memory region may cost us one or two extra 5287 * memmap pages due to alignment because memmap pages for each 5288 * populated regions may not naturally algined on page boundary. 5289 * So the (present_pages >> 4) heuristic is a tradeoff for that. 5290 */ 5291 if (spanned_pages > present_pages + (present_pages >> 4) && 5292 IS_ENABLED(CONFIG_SPARSEMEM)) 5293 pages = present_pages; 5294 5295 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT; 5296 } 5297 5298 /* 5299 * Set up the zone data structures: 5300 * - mark all pages reserved 5301 * - mark all memory queues empty 5302 * - clear the memory bitmaps 5303 * 5304 * NOTE: pgdat should get zeroed by caller. 5305 */ 5306 static void __paginginit free_area_init_core(struct pglist_data *pgdat, 5307 unsigned long node_start_pfn, unsigned long node_end_pfn) 5308 { 5309 enum zone_type j; 5310 int nid = pgdat->node_id; 5311 unsigned long zone_start_pfn = pgdat->node_start_pfn; 5312 int ret; 5313 5314 pgdat_resize_init(pgdat); 5315 #ifdef CONFIG_NUMA_BALANCING 5316 spin_lock_init(&pgdat->numabalancing_migrate_lock); 5317 pgdat->numabalancing_migrate_nr_pages = 0; 5318 pgdat->numabalancing_migrate_next_window = jiffies; 5319 #endif 5320 init_waitqueue_head(&pgdat->kswapd_wait); 5321 init_waitqueue_head(&pgdat->pfmemalloc_wait); 5322 pgdat_page_ext_init(pgdat); 5323 5324 for (j = 0; j < MAX_NR_ZONES; j++) { 5325 struct zone *zone = pgdat->node_zones + j; 5326 unsigned long size, realsize, freesize, memmap_pages; 5327 5328 size = zone->spanned_pages; 5329 realsize = freesize = zone->present_pages; 5330 5331 /* 5332 * Adjust freesize so that it accounts for how much memory 5333 * is used by this zone for memmap. This affects the watermark 5334 * and per-cpu initialisations 5335 */ 5336 memmap_pages = calc_memmap_size(size, realsize); 5337 if (!is_highmem_idx(j)) { 5338 if (freesize >= memmap_pages) { 5339 freesize -= memmap_pages; 5340 if (memmap_pages) 5341 printk(KERN_DEBUG 5342 " %s zone: %lu pages used for memmap\n", 5343 zone_names[j], memmap_pages); 5344 } else 5345 printk(KERN_WARNING 5346 " %s zone: %lu pages exceeds freesize %lu\n", 5347 zone_names[j], memmap_pages, freesize); 5348 } 5349 5350 /* Account for reserved pages */ 5351 if (j == 0 && freesize > dma_reserve) { 5352 freesize -= dma_reserve; 5353 printk(KERN_DEBUG " %s zone: %lu pages reserved\n", 5354 zone_names[0], dma_reserve); 5355 } 5356 5357 if (!is_highmem_idx(j)) 5358 nr_kernel_pages += freesize; 5359 /* Charge for highmem memmap if there are enough kernel pages */ 5360 else if (nr_kernel_pages > memmap_pages * 2) 5361 nr_kernel_pages -= memmap_pages; 5362 nr_all_pages += freesize; 5363 5364 /* 5365 * Set an approximate value for lowmem here, it will be adjusted 5366 * when the bootmem allocator frees pages into the buddy system. 5367 * And all highmem pages will be managed by the buddy system. 5368 */ 5369 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize; 5370 #ifdef CONFIG_NUMA 5371 zone->node = nid; 5372 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio) 5373 / 100; 5374 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100; 5375 #endif 5376 zone->name = zone_names[j]; 5377 spin_lock_init(&zone->lock); 5378 spin_lock_init(&zone->lru_lock); 5379 zone_seqlock_init(zone); 5380 zone->zone_pgdat = pgdat; 5381 zone_pcp_init(zone); 5382 5383 /* For bootup, initialized properly in watermark setup */ 5384 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages); 5385 5386 lruvec_init(&zone->lruvec); 5387 if (!size) 5388 continue; 5389 5390 set_pageblock_order(); 5391 setup_usemap(pgdat, zone, zone_start_pfn, size); 5392 ret = init_currently_empty_zone(zone, zone_start_pfn, 5393 size, MEMMAP_EARLY); 5394 BUG_ON(ret); 5395 memmap_init(size, nid, j, zone_start_pfn); 5396 zone_start_pfn += size; 5397 } 5398 } 5399 5400 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat) 5401 { 5402 /* Skip empty nodes */ 5403 if (!pgdat->node_spanned_pages) 5404 return; 5405 5406 #ifdef CONFIG_FLAT_NODE_MEM_MAP 5407 /* ia64 gets its own node_mem_map, before this, without bootmem */ 5408 if (!pgdat->node_mem_map) { 5409 unsigned long size, start, end; 5410 struct page *map; 5411 5412 /* 5413 * The zone's endpoints aren't required to be MAX_ORDER 5414 * aligned but the node_mem_map endpoints must be in order 5415 * for the buddy allocator to function correctly. 5416 */ 5417 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); 5418 end = pgdat_end_pfn(pgdat); 5419 end = ALIGN(end, MAX_ORDER_NR_PAGES); 5420 size = (end - start) * sizeof(struct page); 5421 map = alloc_remap(pgdat->node_id, size); 5422 if (!map) 5423 map = memblock_virt_alloc_node_nopanic(size, 5424 pgdat->node_id); 5425 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); 5426 } 5427 #ifndef CONFIG_NEED_MULTIPLE_NODES 5428 /* 5429 * With no DISCONTIG, the global mem_map is just set as node 0's 5430 */ 5431 if (pgdat == NODE_DATA(0)) { 5432 mem_map = NODE_DATA(0)->node_mem_map; 5433 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 5434 if (page_to_pfn(mem_map) != pgdat->node_start_pfn) 5435 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET); 5436 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 5437 } 5438 #endif 5439 #endif /* CONFIG_FLAT_NODE_MEM_MAP */ 5440 } 5441 5442 void __paginginit free_area_init_node(int nid, unsigned long *zones_size, 5443 unsigned long node_start_pfn, unsigned long *zholes_size) 5444 { 5445 pg_data_t *pgdat = NODE_DATA(nid); 5446 unsigned long start_pfn = 0; 5447 unsigned long end_pfn = 0; 5448 5449 /* pg_data_t should be reset to zero when it's allocated */ 5450 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx); 5451 5452 reset_deferred_meminit(pgdat); 5453 pgdat->node_id = nid; 5454 pgdat->node_start_pfn = node_start_pfn; 5455 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 5456 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn); 5457 pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid, 5458 (u64)start_pfn << PAGE_SHIFT, ((u64)end_pfn << PAGE_SHIFT) - 1); 5459 #endif 5460 calculate_node_totalpages(pgdat, start_pfn, end_pfn, 5461 zones_size, zholes_size); 5462 5463 alloc_node_mem_map(pgdat); 5464 #ifdef CONFIG_FLAT_NODE_MEM_MAP 5465 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n", 5466 nid, (unsigned long)pgdat, 5467 (unsigned long)pgdat->node_mem_map); 5468 #endif 5469 5470 free_area_init_core(pgdat, start_pfn, end_pfn); 5471 } 5472 5473 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 5474 5475 #if MAX_NUMNODES > 1 5476 /* 5477 * Figure out the number of possible node ids. 5478 */ 5479 void __init setup_nr_node_ids(void) 5480 { 5481 unsigned int node; 5482 unsigned int highest = 0; 5483 5484 for_each_node_mask(node, node_possible_map) 5485 highest = node; 5486 nr_node_ids = highest + 1; 5487 } 5488 #endif 5489 5490 /** 5491 * node_map_pfn_alignment - determine the maximum internode alignment 5492 * 5493 * This function should be called after node map is populated and sorted. 5494 * It calculates the maximum power of two alignment which can distinguish 5495 * all the nodes. 5496 * 5497 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value 5498 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the 5499 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is 5500 * shifted, 1GiB is enough and this function will indicate so. 5501 * 5502 * This is used to test whether pfn -> nid mapping of the chosen memory 5503 * model has fine enough granularity to avoid incorrect mapping for the 5504 * populated node map. 5505 * 5506 * Returns the determined alignment in pfn's. 0 if there is no alignment 5507 * requirement (single node). 5508 */ 5509 unsigned long __init node_map_pfn_alignment(void) 5510 { 5511 unsigned long accl_mask = 0, last_end = 0; 5512 unsigned long start, end, mask; 5513 int last_nid = -1; 5514 int i, nid; 5515 5516 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) { 5517 if (!start || last_nid < 0 || last_nid == nid) { 5518 last_nid = nid; 5519 last_end = end; 5520 continue; 5521 } 5522 5523 /* 5524 * Start with a mask granular enough to pin-point to the 5525 * start pfn and tick off bits one-by-one until it becomes 5526 * too coarse to separate the current node from the last. 5527 */ 5528 mask = ~((1 << __ffs(start)) - 1); 5529 while (mask && last_end <= (start & (mask << 1))) 5530 mask <<= 1; 5531 5532 /* accumulate all internode masks */ 5533 accl_mask |= mask; 5534 } 5535 5536 /* convert mask to number of pages */ 5537 return ~accl_mask + 1; 5538 } 5539 5540 /* Find the lowest pfn for a node */ 5541 static unsigned long __init find_min_pfn_for_node(int nid) 5542 { 5543 unsigned long min_pfn = ULONG_MAX; 5544 unsigned long start_pfn; 5545 int i; 5546 5547 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL) 5548 min_pfn = min(min_pfn, start_pfn); 5549 5550 if (min_pfn == ULONG_MAX) { 5551 printk(KERN_WARNING 5552 "Could not find start_pfn for node %d\n", nid); 5553 return 0; 5554 } 5555 5556 return min_pfn; 5557 } 5558 5559 /** 5560 * find_min_pfn_with_active_regions - Find the minimum PFN registered 5561 * 5562 * It returns the minimum PFN based on information provided via 5563 * memblock_set_node(). 5564 */ 5565 unsigned long __init find_min_pfn_with_active_regions(void) 5566 { 5567 return find_min_pfn_for_node(MAX_NUMNODES); 5568 } 5569 5570 /* 5571 * early_calculate_totalpages() 5572 * Sum pages in active regions for movable zone. 5573 * Populate N_MEMORY for calculating usable_nodes. 5574 */ 5575 static unsigned long __init early_calculate_totalpages(void) 5576 { 5577 unsigned long totalpages = 0; 5578 unsigned long start_pfn, end_pfn; 5579 int i, nid; 5580 5581 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { 5582 unsigned long pages = end_pfn - start_pfn; 5583 5584 totalpages += pages; 5585 if (pages) 5586 node_set_state(nid, N_MEMORY); 5587 } 5588 return totalpages; 5589 } 5590 5591 /* 5592 * Find the PFN the Movable zone begins in each node. Kernel memory 5593 * is spread evenly between nodes as long as the nodes have enough 5594 * memory. When they don't, some nodes will have more kernelcore than 5595 * others 5596 */ 5597 static void __init find_zone_movable_pfns_for_nodes(void) 5598 { 5599 int i, nid; 5600 unsigned long usable_startpfn; 5601 unsigned long kernelcore_node, kernelcore_remaining; 5602 /* save the state before borrow the nodemask */ 5603 nodemask_t saved_node_state = node_states[N_MEMORY]; 5604 unsigned long totalpages = early_calculate_totalpages(); 5605 int usable_nodes = nodes_weight(node_states[N_MEMORY]); 5606 struct memblock_region *r; 5607 5608 /* Need to find movable_zone earlier when movable_node is specified. */ 5609 find_usable_zone_for_movable(); 5610 5611 /* 5612 * If movable_node is specified, ignore kernelcore and movablecore 5613 * options. 5614 */ 5615 if (movable_node_is_enabled()) { 5616 for_each_memblock(memory, r) { 5617 if (!memblock_is_hotpluggable(r)) 5618 continue; 5619 5620 nid = r->nid; 5621 5622 usable_startpfn = PFN_DOWN(r->base); 5623 zone_movable_pfn[nid] = zone_movable_pfn[nid] ? 5624 min(usable_startpfn, zone_movable_pfn[nid]) : 5625 usable_startpfn; 5626 } 5627 5628 goto out2; 5629 } 5630 5631 /* 5632 * If movablecore=nn[KMG] was specified, calculate what size of 5633 * kernelcore that corresponds so that memory usable for 5634 * any allocation type is evenly spread. If both kernelcore 5635 * and movablecore are specified, then the value of kernelcore 5636 * will be used for required_kernelcore if it's greater than 5637 * what movablecore would have allowed. 5638 */ 5639 if (required_movablecore) { 5640 unsigned long corepages; 5641 5642 /* 5643 * Round-up so that ZONE_MOVABLE is at least as large as what 5644 * was requested by the user 5645 */ 5646 required_movablecore = 5647 roundup(required_movablecore, MAX_ORDER_NR_PAGES); 5648 corepages = totalpages - required_movablecore; 5649 5650 required_kernelcore = max(required_kernelcore, corepages); 5651 } 5652 5653 /* If kernelcore was not specified, there is no ZONE_MOVABLE */ 5654 if (!required_kernelcore) 5655 goto out; 5656 5657 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ 5658 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; 5659 5660 restart: 5661 /* Spread kernelcore memory as evenly as possible throughout nodes */ 5662 kernelcore_node = required_kernelcore / usable_nodes; 5663 for_each_node_state(nid, N_MEMORY) { 5664 unsigned long start_pfn, end_pfn; 5665 5666 /* 5667 * Recalculate kernelcore_node if the division per node 5668 * now exceeds what is necessary to satisfy the requested 5669 * amount of memory for the kernel 5670 */ 5671 if (required_kernelcore < kernelcore_node) 5672 kernelcore_node = required_kernelcore / usable_nodes; 5673 5674 /* 5675 * As the map is walked, we track how much memory is usable 5676 * by the kernel using kernelcore_remaining. When it is 5677 * 0, the rest of the node is usable by ZONE_MOVABLE 5678 */ 5679 kernelcore_remaining = kernelcore_node; 5680 5681 /* Go through each range of PFNs within this node */ 5682 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { 5683 unsigned long size_pages; 5684 5685 start_pfn = max(start_pfn, zone_movable_pfn[nid]); 5686 if (start_pfn >= end_pfn) 5687 continue; 5688 5689 /* Account for what is only usable for kernelcore */ 5690 if (start_pfn < usable_startpfn) { 5691 unsigned long kernel_pages; 5692 kernel_pages = min(end_pfn, usable_startpfn) 5693 - start_pfn; 5694 5695 kernelcore_remaining -= min(kernel_pages, 5696 kernelcore_remaining); 5697 required_kernelcore -= min(kernel_pages, 5698 required_kernelcore); 5699 5700 /* Continue if range is now fully accounted */ 5701 if (end_pfn <= usable_startpfn) { 5702 5703 /* 5704 * Push zone_movable_pfn to the end so 5705 * that if we have to rebalance 5706 * kernelcore across nodes, we will 5707 * not double account here 5708 */ 5709 zone_movable_pfn[nid] = end_pfn; 5710 continue; 5711 } 5712 start_pfn = usable_startpfn; 5713 } 5714 5715 /* 5716 * The usable PFN range for ZONE_MOVABLE is from 5717 * start_pfn->end_pfn. Calculate size_pages as the 5718 * number of pages used as kernelcore 5719 */ 5720 size_pages = end_pfn - start_pfn; 5721 if (size_pages > kernelcore_remaining) 5722 size_pages = kernelcore_remaining; 5723 zone_movable_pfn[nid] = start_pfn + size_pages; 5724 5725 /* 5726 * Some kernelcore has been met, update counts and 5727 * break if the kernelcore for this node has been 5728 * satisfied 5729 */ 5730 required_kernelcore -= min(required_kernelcore, 5731 size_pages); 5732 kernelcore_remaining -= size_pages; 5733 if (!kernelcore_remaining) 5734 break; 5735 } 5736 } 5737 5738 /* 5739 * If there is still required_kernelcore, we do another pass with one 5740 * less node in the count. This will push zone_movable_pfn[nid] further 5741 * along on the nodes that still have memory until kernelcore is 5742 * satisfied 5743 */ 5744 usable_nodes--; 5745 if (usable_nodes && required_kernelcore > usable_nodes) 5746 goto restart; 5747 5748 out2: 5749 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ 5750 for (nid = 0; nid < MAX_NUMNODES; nid++) 5751 zone_movable_pfn[nid] = 5752 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); 5753 5754 out: 5755 /* restore the node_state */ 5756 node_states[N_MEMORY] = saved_node_state; 5757 } 5758 5759 /* Any regular or high memory on that node ? */ 5760 static void check_for_memory(pg_data_t *pgdat, int nid) 5761 { 5762 enum zone_type zone_type; 5763 5764 if (N_MEMORY == N_NORMAL_MEMORY) 5765 return; 5766 5767 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) { 5768 struct zone *zone = &pgdat->node_zones[zone_type]; 5769 if (populated_zone(zone)) { 5770 node_set_state(nid, N_HIGH_MEMORY); 5771 if (N_NORMAL_MEMORY != N_HIGH_MEMORY && 5772 zone_type <= ZONE_NORMAL) 5773 node_set_state(nid, N_NORMAL_MEMORY); 5774 break; 5775 } 5776 } 5777 } 5778 5779 /** 5780 * free_area_init_nodes - Initialise all pg_data_t and zone data 5781 * @max_zone_pfn: an array of max PFNs for each zone 5782 * 5783 * This will call free_area_init_node() for each active node in the system. 5784 * Using the page ranges provided by memblock_set_node(), the size of each 5785 * zone in each node and their holes is calculated. If the maximum PFN 5786 * between two adjacent zones match, it is assumed that the zone is empty. 5787 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed 5788 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone 5789 * starts where the previous one ended. For example, ZONE_DMA32 starts 5790 * at arch_max_dma_pfn. 5791 */ 5792 void __init free_area_init_nodes(unsigned long *max_zone_pfn) 5793 { 5794 unsigned long start_pfn, end_pfn; 5795 int i, nid; 5796 5797 /* Record where the zone boundaries are */ 5798 memset(arch_zone_lowest_possible_pfn, 0, 5799 sizeof(arch_zone_lowest_possible_pfn)); 5800 memset(arch_zone_highest_possible_pfn, 0, 5801 sizeof(arch_zone_highest_possible_pfn)); 5802 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); 5803 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; 5804 for (i = 1; i < MAX_NR_ZONES; i++) { 5805 if (i == ZONE_MOVABLE) 5806 continue; 5807 arch_zone_lowest_possible_pfn[i] = 5808 arch_zone_highest_possible_pfn[i-1]; 5809 arch_zone_highest_possible_pfn[i] = 5810 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); 5811 } 5812 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0; 5813 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0; 5814 5815 /* Find the PFNs that ZONE_MOVABLE begins at in each node */ 5816 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); 5817 find_zone_movable_pfns_for_nodes(); 5818 5819 /* Print out the zone ranges */ 5820 pr_info("Zone ranges:\n"); 5821 for (i = 0; i < MAX_NR_ZONES; i++) { 5822 if (i == ZONE_MOVABLE) 5823 continue; 5824 pr_info(" %-8s ", zone_names[i]); 5825 if (arch_zone_lowest_possible_pfn[i] == 5826 arch_zone_highest_possible_pfn[i]) 5827 pr_cont("empty\n"); 5828 else 5829 pr_cont("[mem %#018Lx-%#018Lx]\n", 5830 (u64)arch_zone_lowest_possible_pfn[i] 5831 << PAGE_SHIFT, 5832 ((u64)arch_zone_highest_possible_pfn[i] 5833 << PAGE_SHIFT) - 1); 5834 } 5835 5836 /* Print out the PFNs ZONE_MOVABLE begins at in each node */ 5837 pr_info("Movable zone start for each node\n"); 5838 for (i = 0; i < MAX_NUMNODES; i++) { 5839 if (zone_movable_pfn[i]) 5840 pr_info(" Node %d: %#018Lx\n", i, 5841 (u64)zone_movable_pfn[i] << PAGE_SHIFT); 5842 } 5843 5844 /* Print out the early node map */ 5845 pr_info("Early memory node ranges\n"); 5846 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) 5847 pr_info(" node %3d: [mem %#018Lx-%#018Lx]\n", nid, 5848 (u64)start_pfn << PAGE_SHIFT, 5849 ((u64)end_pfn << PAGE_SHIFT) - 1); 5850 5851 /* Initialise every node */ 5852 mminit_verify_pageflags_layout(); 5853 setup_nr_node_ids(); 5854 for_each_online_node(nid) { 5855 pg_data_t *pgdat = NODE_DATA(nid); 5856 free_area_init_node(nid, NULL, 5857 find_min_pfn_for_node(nid), NULL); 5858 5859 /* Any memory on that node */ 5860 if (pgdat->node_present_pages) 5861 node_set_state(nid, N_MEMORY); 5862 check_for_memory(pgdat, nid); 5863 } 5864 } 5865 5866 static int __init cmdline_parse_core(char *p, unsigned long *core) 5867 { 5868 unsigned long long coremem; 5869 if (!p) 5870 return -EINVAL; 5871 5872 coremem = memparse(p, &p); 5873 *core = coremem >> PAGE_SHIFT; 5874 5875 /* Paranoid check that UL is enough for the coremem value */ 5876 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); 5877 5878 return 0; 5879 } 5880 5881 /* 5882 * kernelcore=size sets the amount of memory for use for allocations that 5883 * cannot be reclaimed or migrated. 5884 */ 5885 static int __init cmdline_parse_kernelcore(char *p) 5886 { 5887 return cmdline_parse_core(p, &required_kernelcore); 5888 } 5889 5890 /* 5891 * movablecore=size sets the amount of memory for use for allocations that 5892 * can be reclaimed or migrated. 5893 */ 5894 static int __init cmdline_parse_movablecore(char *p) 5895 { 5896 return cmdline_parse_core(p, &required_movablecore); 5897 } 5898 5899 early_param("kernelcore", cmdline_parse_kernelcore); 5900 early_param("movablecore", cmdline_parse_movablecore); 5901 5902 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 5903 5904 void adjust_managed_page_count(struct page *page, long count) 5905 { 5906 spin_lock(&managed_page_count_lock); 5907 page_zone(page)->managed_pages += count; 5908 totalram_pages += count; 5909 #ifdef CONFIG_HIGHMEM 5910 if (PageHighMem(page)) 5911 totalhigh_pages += count; 5912 #endif 5913 spin_unlock(&managed_page_count_lock); 5914 } 5915 EXPORT_SYMBOL(adjust_managed_page_count); 5916 5917 unsigned long free_reserved_area(void *start, void *end, int poison, char *s) 5918 { 5919 void *pos; 5920 unsigned long pages = 0; 5921 5922 start = (void *)PAGE_ALIGN((unsigned long)start); 5923 end = (void *)((unsigned long)end & PAGE_MASK); 5924 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) { 5925 if ((unsigned int)poison <= 0xFF) 5926 memset(pos, poison, PAGE_SIZE); 5927 free_reserved_page(virt_to_page(pos)); 5928 } 5929 5930 if (pages && s) 5931 pr_info("Freeing %s memory: %ldK (%p - %p)\n", 5932 s, pages << (PAGE_SHIFT - 10), start, end); 5933 5934 return pages; 5935 } 5936 EXPORT_SYMBOL(free_reserved_area); 5937 5938 #ifdef CONFIG_HIGHMEM 5939 void free_highmem_page(struct page *page) 5940 { 5941 __free_reserved_page(page); 5942 totalram_pages++; 5943 page_zone(page)->managed_pages++; 5944 totalhigh_pages++; 5945 } 5946 #endif 5947 5948 5949 void __init mem_init_print_info(const char *str) 5950 { 5951 unsigned long physpages, codesize, datasize, rosize, bss_size; 5952 unsigned long init_code_size, init_data_size; 5953 5954 physpages = get_num_physpages(); 5955 codesize = _etext - _stext; 5956 datasize = _edata - _sdata; 5957 rosize = __end_rodata - __start_rodata; 5958 bss_size = __bss_stop - __bss_start; 5959 init_data_size = __init_end - __init_begin; 5960 init_code_size = _einittext - _sinittext; 5961 5962 /* 5963 * Detect special cases and adjust section sizes accordingly: 5964 * 1) .init.* may be embedded into .data sections 5965 * 2) .init.text.* may be out of [__init_begin, __init_end], 5966 * please refer to arch/tile/kernel/vmlinux.lds.S. 5967 * 3) .rodata.* may be embedded into .text or .data sections. 5968 */ 5969 #define adj_init_size(start, end, size, pos, adj) \ 5970 do { \ 5971 if (start <= pos && pos < end && size > adj) \ 5972 size -= adj; \ 5973 } while (0) 5974 5975 adj_init_size(__init_begin, __init_end, init_data_size, 5976 _sinittext, init_code_size); 5977 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size); 5978 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size); 5979 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize); 5980 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize); 5981 5982 #undef adj_init_size 5983 5984 pr_info("Memory: %luK/%luK available " 5985 "(%luK kernel code, %luK rwdata, %luK rodata, " 5986 "%luK init, %luK bss, %luK reserved, %luK cma-reserved" 5987 #ifdef CONFIG_HIGHMEM 5988 ", %luK highmem" 5989 #endif 5990 "%s%s)\n", 5991 nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10), 5992 codesize >> 10, datasize >> 10, rosize >> 10, 5993 (init_data_size + init_code_size) >> 10, bss_size >> 10, 5994 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT-10), 5995 totalcma_pages << (PAGE_SHIFT-10), 5996 #ifdef CONFIG_HIGHMEM 5997 totalhigh_pages << (PAGE_SHIFT-10), 5998 #endif 5999 str ? ", " : "", str ? str : ""); 6000 } 6001 6002 /** 6003 * set_dma_reserve - set the specified number of pages reserved in the first zone 6004 * @new_dma_reserve: The number of pages to mark reserved 6005 * 6006 * The per-cpu batchsize and zone watermarks are determined by present_pages. 6007 * In the DMA zone, a significant percentage may be consumed by kernel image 6008 * and other unfreeable allocations which can skew the watermarks badly. This 6009 * function may optionally be used to account for unfreeable pages in the 6010 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and 6011 * smaller per-cpu batchsize. 6012 */ 6013 void __init set_dma_reserve(unsigned long new_dma_reserve) 6014 { 6015 dma_reserve = new_dma_reserve; 6016 } 6017 6018 void __init free_area_init(unsigned long *zones_size) 6019 { 6020 free_area_init_node(0, zones_size, 6021 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 6022 } 6023 6024 static int page_alloc_cpu_notify(struct notifier_block *self, 6025 unsigned long action, void *hcpu) 6026 { 6027 int cpu = (unsigned long)hcpu; 6028 6029 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { 6030 lru_add_drain_cpu(cpu); 6031 drain_pages(cpu); 6032 6033 /* 6034 * Spill the event counters of the dead processor 6035 * into the current processors event counters. 6036 * This artificially elevates the count of the current 6037 * processor. 6038 */ 6039 vm_events_fold_cpu(cpu); 6040 6041 /* 6042 * Zero the differential counters of the dead processor 6043 * so that the vm statistics are consistent. 6044 * 6045 * This is only okay since the processor is dead and cannot 6046 * race with what we are doing. 6047 */ 6048 cpu_vm_stats_fold(cpu); 6049 } 6050 return NOTIFY_OK; 6051 } 6052 6053 void __init page_alloc_init(void) 6054 { 6055 hotcpu_notifier(page_alloc_cpu_notify, 0); 6056 } 6057 6058 /* 6059 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio 6060 * or min_free_kbytes changes. 6061 */ 6062 static void calculate_totalreserve_pages(void) 6063 { 6064 struct pglist_data *pgdat; 6065 unsigned long reserve_pages = 0; 6066 enum zone_type i, j; 6067 6068 for_each_online_pgdat(pgdat) { 6069 for (i = 0; i < MAX_NR_ZONES; i++) { 6070 struct zone *zone = pgdat->node_zones + i; 6071 long max = 0; 6072 6073 /* Find valid and maximum lowmem_reserve in the zone */ 6074 for (j = i; j < MAX_NR_ZONES; j++) { 6075 if (zone->lowmem_reserve[j] > max) 6076 max = zone->lowmem_reserve[j]; 6077 } 6078 6079 /* we treat the high watermark as reserved pages. */ 6080 max += high_wmark_pages(zone); 6081 6082 if (max > zone->managed_pages) 6083 max = zone->managed_pages; 6084 reserve_pages += max; 6085 /* 6086 * Lowmem reserves are not available to 6087 * GFP_HIGHUSER page cache allocations and 6088 * kswapd tries to balance zones to their high 6089 * watermark. As a result, neither should be 6090 * regarded as dirtyable memory, to prevent a 6091 * situation where reclaim has to clean pages 6092 * in order to balance the zones. 6093 */ 6094 zone->dirty_balance_reserve = max; 6095 } 6096 } 6097 dirty_balance_reserve = reserve_pages; 6098 totalreserve_pages = reserve_pages; 6099 } 6100 6101 /* 6102 * setup_per_zone_lowmem_reserve - called whenever 6103 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 6104 * has a correct pages reserved value, so an adequate number of 6105 * pages are left in the zone after a successful __alloc_pages(). 6106 */ 6107 static void setup_per_zone_lowmem_reserve(void) 6108 { 6109 struct pglist_data *pgdat; 6110 enum zone_type j, idx; 6111 6112 for_each_online_pgdat(pgdat) { 6113 for (j = 0; j < MAX_NR_ZONES; j++) { 6114 struct zone *zone = pgdat->node_zones + j; 6115 unsigned long managed_pages = zone->managed_pages; 6116 6117 zone->lowmem_reserve[j] = 0; 6118 6119 idx = j; 6120 while (idx) { 6121 struct zone *lower_zone; 6122 6123 idx--; 6124 6125 if (sysctl_lowmem_reserve_ratio[idx] < 1) 6126 sysctl_lowmem_reserve_ratio[idx] = 1; 6127 6128 lower_zone = pgdat->node_zones + idx; 6129 lower_zone->lowmem_reserve[j] = managed_pages / 6130 sysctl_lowmem_reserve_ratio[idx]; 6131 managed_pages += lower_zone->managed_pages; 6132 } 6133 } 6134 } 6135 6136 /* update totalreserve_pages */ 6137 calculate_totalreserve_pages(); 6138 } 6139 6140 static void __setup_per_zone_wmarks(void) 6141 { 6142 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 6143 unsigned long lowmem_pages = 0; 6144 struct zone *zone; 6145 unsigned long flags; 6146 6147 /* Calculate total number of !ZONE_HIGHMEM pages */ 6148 for_each_zone(zone) { 6149 if (!is_highmem(zone)) 6150 lowmem_pages += zone->managed_pages; 6151 } 6152 6153 for_each_zone(zone) { 6154 u64 tmp; 6155 6156 spin_lock_irqsave(&zone->lock, flags); 6157 tmp = (u64)pages_min * zone->managed_pages; 6158 do_div(tmp, lowmem_pages); 6159 if (is_highmem(zone)) { 6160 /* 6161 * __GFP_HIGH and PF_MEMALLOC allocations usually don't 6162 * need highmem pages, so cap pages_min to a small 6163 * value here. 6164 * 6165 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN) 6166 * deltas control asynch page reclaim, and so should 6167 * not be capped for highmem. 6168 */ 6169 unsigned long min_pages; 6170 6171 min_pages = zone->managed_pages / 1024; 6172 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL); 6173 zone->watermark[WMARK_MIN] = min_pages; 6174 } else { 6175 /* 6176 * If it's a lowmem zone, reserve a number of pages 6177 * proportionate to the zone's size. 6178 */ 6179 zone->watermark[WMARK_MIN] = tmp; 6180 } 6181 6182 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2); 6183 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1); 6184 6185 __mod_zone_page_state(zone, NR_ALLOC_BATCH, 6186 high_wmark_pages(zone) - low_wmark_pages(zone) - 6187 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH])); 6188 6189 setup_zone_migrate_reserve(zone); 6190 spin_unlock_irqrestore(&zone->lock, flags); 6191 } 6192 6193 /* update totalreserve_pages */ 6194 calculate_totalreserve_pages(); 6195 } 6196 6197 /** 6198 * setup_per_zone_wmarks - called when min_free_kbytes changes 6199 * or when memory is hot-{added|removed} 6200 * 6201 * Ensures that the watermark[min,low,high] values for each zone are set 6202 * correctly with respect to min_free_kbytes. 6203 */ 6204 void setup_per_zone_wmarks(void) 6205 { 6206 mutex_lock(&zonelists_mutex); 6207 __setup_per_zone_wmarks(); 6208 mutex_unlock(&zonelists_mutex); 6209 } 6210 6211 /* 6212 * The inactive anon list should be small enough that the VM never has to 6213 * do too much work, but large enough that each inactive page has a chance 6214 * to be referenced again before it is swapped out. 6215 * 6216 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to 6217 * INACTIVE_ANON pages on this zone's LRU, maintained by the 6218 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of 6219 * the anonymous pages are kept on the inactive list. 6220 * 6221 * total target max 6222 * memory ratio inactive anon 6223 * ------------------------------------- 6224 * 10MB 1 5MB 6225 * 100MB 1 50MB 6226 * 1GB 3 250MB 6227 * 10GB 10 0.9GB 6228 * 100GB 31 3GB 6229 * 1TB 101 10GB 6230 * 10TB 320 32GB 6231 */ 6232 static void __meminit calculate_zone_inactive_ratio(struct zone *zone) 6233 { 6234 unsigned int gb, ratio; 6235 6236 /* Zone size in gigabytes */ 6237 gb = zone->managed_pages >> (30 - PAGE_SHIFT); 6238 if (gb) 6239 ratio = int_sqrt(10 * gb); 6240 else 6241 ratio = 1; 6242 6243 zone->inactive_ratio = ratio; 6244 } 6245 6246 static void __meminit setup_per_zone_inactive_ratio(void) 6247 { 6248 struct zone *zone; 6249 6250 for_each_zone(zone) 6251 calculate_zone_inactive_ratio(zone); 6252 } 6253 6254 /* 6255 * Initialise min_free_kbytes. 6256 * 6257 * For small machines we want it small (128k min). For large machines 6258 * we want it large (64MB max). But it is not linear, because network 6259 * bandwidth does not increase linearly with machine size. We use 6260 * 6261 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 6262 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 6263 * 6264 * which yields 6265 * 6266 * 16MB: 512k 6267 * 32MB: 724k 6268 * 64MB: 1024k 6269 * 128MB: 1448k 6270 * 256MB: 2048k 6271 * 512MB: 2896k 6272 * 1024MB: 4096k 6273 * 2048MB: 5792k 6274 * 4096MB: 8192k 6275 * 8192MB: 11584k 6276 * 16384MB: 16384k 6277 */ 6278 int __meminit init_per_zone_wmark_min(void) 6279 { 6280 unsigned long lowmem_kbytes; 6281 int new_min_free_kbytes; 6282 6283 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 6284 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 6285 6286 if (new_min_free_kbytes > user_min_free_kbytes) { 6287 min_free_kbytes = new_min_free_kbytes; 6288 if (min_free_kbytes < 128) 6289 min_free_kbytes = 128; 6290 if (min_free_kbytes > 65536) 6291 min_free_kbytes = 65536; 6292 } else { 6293 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n", 6294 new_min_free_kbytes, user_min_free_kbytes); 6295 } 6296 setup_per_zone_wmarks(); 6297 refresh_zone_stat_thresholds(); 6298 setup_per_zone_lowmem_reserve(); 6299 setup_per_zone_inactive_ratio(); 6300 return 0; 6301 } 6302 module_init(init_per_zone_wmark_min) 6303 6304 /* 6305 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 6306 * that we can call two helper functions whenever min_free_kbytes 6307 * changes. 6308 */ 6309 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write, 6310 void __user *buffer, size_t *length, loff_t *ppos) 6311 { 6312 int rc; 6313 6314 rc = proc_dointvec_minmax(table, write, buffer, length, ppos); 6315 if (rc) 6316 return rc; 6317 6318 if (write) { 6319 user_min_free_kbytes = min_free_kbytes; 6320 setup_per_zone_wmarks(); 6321 } 6322 return 0; 6323 } 6324 6325 #ifdef CONFIG_NUMA 6326 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write, 6327 void __user *buffer, size_t *length, loff_t *ppos) 6328 { 6329 struct zone *zone; 6330 int rc; 6331 6332 rc = proc_dointvec_minmax(table, write, buffer, length, ppos); 6333 if (rc) 6334 return rc; 6335 6336 for_each_zone(zone) 6337 zone->min_unmapped_pages = (zone->managed_pages * 6338 sysctl_min_unmapped_ratio) / 100; 6339 return 0; 6340 } 6341 6342 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write, 6343 void __user *buffer, size_t *length, loff_t *ppos) 6344 { 6345 struct zone *zone; 6346 int rc; 6347 6348 rc = proc_dointvec_minmax(table, write, buffer, length, ppos); 6349 if (rc) 6350 return rc; 6351 6352 for_each_zone(zone) 6353 zone->min_slab_pages = (zone->managed_pages * 6354 sysctl_min_slab_ratio) / 100; 6355 return 0; 6356 } 6357 #endif 6358 6359 /* 6360 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 6361 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 6362 * whenever sysctl_lowmem_reserve_ratio changes. 6363 * 6364 * The reserve ratio obviously has absolutely no relation with the 6365 * minimum watermarks. The lowmem reserve ratio can only make sense 6366 * if in function of the boot time zone sizes. 6367 */ 6368 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write, 6369 void __user *buffer, size_t *length, loff_t *ppos) 6370 { 6371 proc_dointvec_minmax(table, write, buffer, length, ppos); 6372 setup_per_zone_lowmem_reserve(); 6373 return 0; 6374 } 6375 6376 /* 6377 * percpu_pagelist_fraction - changes the pcp->high for each zone on each 6378 * cpu. It is the fraction of total pages in each zone that a hot per cpu 6379 * pagelist can have before it gets flushed back to buddy allocator. 6380 */ 6381 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write, 6382 void __user *buffer, size_t *length, loff_t *ppos) 6383 { 6384 struct zone *zone; 6385 int old_percpu_pagelist_fraction; 6386 int ret; 6387 6388 mutex_lock(&pcp_batch_high_lock); 6389 old_percpu_pagelist_fraction = percpu_pagelist_fraction; 6390 6391 ret = proc_dointvec_minmax(table, write, buffer, length, ppos); 6392 if (!write || ret < 0) 6393 goto out; 6394 6395 /* Sanity checking to avoid pcp imbalance */ 6396 if (percpu_pagelist_fraction && 6397 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) { 6398 percpu_pagelist_fraction = old_percpu_pagelist_fraction; 6399 ret = -EINVAL; 6400 goto out; 6401 } 6402 6403 /* No change? */ 6404 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction) 6405 goto out; 6406 6407 for_each_populated_zone(zone) { 6408 unsigned int cpu; 6409 6410 for_each_possible_cpu(cpu) 6411 pageset_set_high_and_batch(zone, 6412 per_cpu_ptr(zone->pageset, cpu)); 6413 } 6414 out: 6415 mutex_unlock(&pcp_batch_high_lock); 6416 return ret; 6417 } 6418 6419 #ifdef CONFIG_NUMA 6420 int hashdist = HASHDIST_DEFAULT; 6421 6422 static int __init set_hashdist(char *str) 6423 { 6424 if (!str) 6425 return 0; 6426 hashdist = simple_strtoul(str, &str, 0); 6427 return 1; 6428 } 6429 __setup("hashdist=", set_hashdist); 6430 #endif 6431 6432 /* 6433 * allocate a large system hash table from bootmem 6434 * - it is assumed that the hash table must contain an exact power-of-2 6435 * quantity of entries 6436 * - limit is the number of hash buckets, not the total allocation size 6437 */ 6438 void *__init alloc_large_system_hash(const char *tablename, 6439 unsigned long bucketsize, 6440 unsigned long numentries, 6441 int scale, 6442 int flags, 6443 unsigned int *_hash_shift, 6444 unsigned int *_hash_mask, 6445 unsigned long low_limit, 6446 unsigned long high_limit) 6447 { 6448 unsigned long long max = high_limit; 6449 unsigned long log2qty, size; 6450 void *table = NULL; 6451 6452 /* allow the kernel cmdline to have a say */ 6453 if (!numentries) { 6454 /* round applicable memory size up to nearest megabyte */ 6455 numentries = nr_kernel_pages; 6456 6457 /* It isn't necessary when PAGE_SIZE >= 1MB */ 6458 if (PAGE_SHIFT < 20) 6459 numentries = round_up(numentries, (1<<20)/PAGE_SIZE); 6460 6461 /* limit to 1 bucket per 2^scale bytes of low memory */ 6462 if (scale > PAGE_SHIFT) 6463 numentries >>= (scale - PAGE_SHIFT); 6464 else 6465 numentries <<= (PAGE_SHIFT - scale); 6466 6467 /* Make sure we've got at least a 0-order allocation.. */ 6468 if (unlikely(flags & HASH_SMALL)) { 6469 /* Makes no sense without HASH_EARLY */ 6470 WARN_ON(!(flags & HASH_EARLY)); 6471 if (!(numentries >> *_hash_shift)) { 6472 numentries = 1UL << *_hash_shift; 6473 BUG_ON(!numentries); 6474 } 6475 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE)) 6476 numentries = PAGE_SIZE / bucketsize; 6477 } 6478 numentries = roundup_pow_of_two(numentries); 6479 6480 /* limit allocation size to 1/16 total memory by default */ 6481 if (max == 0) { 6482 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 6483 do_div(max, bucketsize); 6484 } 6485 max = min(max, 0x80000000ULL); 6486 6487 if (numentries < low_limit) 6488 numentries = low_limit; 6489 if (numentries > max) 6490 numentries = max; 6491 6492 log2qty = ilog2(numentries); 6493 6494 do { 6495 size = bucketsize << log2qty; 6496 if (flags & HASH_EARLY) 6497 table = memblock_virt_alloc_nopanic(size, 0); 6498 else if (hashdist) 6499 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 6500 else { 6501 /* 6502 * If bucketsize is not a power-of-two, we may free 6503 * some pages at the end of hash table which 6504 * alloc_pages_exact() automatically does 6505 */ 6506 if (get_order(size) < MAX_ORDER) { 6507 table = alloc_pages_exact(size, GFP_ATOMIC); 6508 kmemleak_alloc(table, size, 1, GFP_ATOMIC); 6509 } 6510 } 6511 } while (!table && size > PAGE_SIZE && --log2qty); 6512 6513 if (!table) 6514 panic("Failed to allocate %s hash table\n", tablename); 6515 6516 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n", 6517 tablename, 6518 (1UL << log2qty), 6519 ilog2(size) - PAGE_SHIFT, 6520 size); 6521 6522 if (_hash_shift) 6523 *_hash_shift = log2qty; 6524 if (_hash_mask) 6525 *_hash_mask = (1 << log2qty) - 1; 6526 6527 return table; 6528 } 6529 6530 /* Return a pointer to the bitmap storing bits affecting a block of pages */ 6531 static inline unsigned long *get_pageblock_bitmap(struct zone *zone, 6532 unsigned long pfn) 6533 { 6534 #ifdef CONFIG_SPARSEMEM 6535 return __pfn_to_section(pfn)->pageblock_flags; 6536 #else 6537 return zone->pageblock_flags; 6538 #endif /* CONFIG_SPARSEMEM */ 6539 } 6540 6541 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) 6542 { 6543 #ifdef CONFIG_SPARSEMEM 6544 pfn &= (PAGES_PER_SECTION-1); 6545 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 6546 #else 6547 pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages); 6548 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 6549 #endif /* CONFIG_SPARSEMEM */ 6550 } 6551 6552 /** 6553 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages 6554 * @page: The page within the block of interest 6555 * @pfn: The target page frame number 6556 * @end_bitidx: The last bit of interest to retrieve 6557 * @mask: mask of bits that the caller is interested in 6558 * 6559 * Return: pageblock_bits flags 6560 */ 6561 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn, 6562 unsigned long end_bitidx, 6563 unsigned long mask) 6564 { 6565 struct zone *zone; 6566 unsigned long *bitmap; 6567 unsigned long bitidx, word_bitidx; 6568 unsigned long word; 6569 6570 zone = page_zone(page); 6571 bitmap = get_pageblock_bitmap(zone, pfn); 6572 bitidx = pfn_to_bitidx(zone, pfn); 6573 word_bitidx = bitidx / BITS_PER_LONG; 6574 bitidx &= (BITS_PER_LONG-1); 6575 6576 word = bitmap[word_bitidx]; 6577 bitidx += end_bitidx; 6578 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask; 6579 } 6580 6581 /** 6582 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages 6583 * @page: The page within the block of interest 6584 * @flags: The flags to set 6585 * @pfn: The target page frame number 6586 * @end_bitidx: The last bit of interest 6587 * @mask: mask of bits that the caller is interested in 6588 */ 6589 void set_pfnblock_flags_mask(struct page *page, unsigned long flags, 6590 unsigned long pfn, 6591 unsigned long end_bitidx, 6592 unsigned long mask) 6593 { 6594 struct zone *zone; 6595 unsigned long *bitmap; 6596 unsigned long bitidx, word_bitidx; 6597 unsigned long old_word, word; 6598 6599 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4); 6600 6601 zone = page_zone(page); 6602 bitmap = get_pageblock_bitmap(zone, pfn); 6603 bitidx = pfn_to_bitidx(zone, pfn); 6604 word_bitidx = bitidx / BITS_PER_LONG; 6605 bitidx &= (BITS_PER_LONG-1); 6606 6607 VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page); 6608 6609 bitidx += end_bitidx; 6610 mask <<= (BITS_PER_LONG - bitidx - 1); 6611 flags <<= (BITS_PER_LONG - bitidx - 1); 6612 6613 word = READ_ONCE(bitmap[word_bitidx]); 6614 for (;;) { 6615 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags); 6616 if (word == old_word) 6617 break; 6618 word = old_word; 6619 } 6620 } 6621 6622 /* 6623 * This function checks whether pageblock includes unmovable pages or not. 6624 * If @count is not zero, it is okay to include less @count unmovable pages 6625 * 6626 * PageLRU check without isolation or lru_lock could race so that 6627 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't 6628 * expect this function should be exact. 6629 */ 6630 bool has_unmovable_pages(struct zone *zone, struct page *page, int count, 6631 bool skip_hwpoisoned_pages) 6632 { 6633 unsigned long pfn, iter, found; 6634 int mt; 6635 6636 /* 6637 * For avoiding noise data, lru_add_drain_all() should be called 6638 * If ZONE_MOVABLE, the zone never contains unmovable pages 6639 */ 6640 if (zone_idx(zone) == ZONE_MOVABLE) 6641 return false; 6642 mt = get_pageblock_migratetype(page); 6643 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt)) 6644 return false; 6645 6646 pfn = page_to_pfn(page); 6647 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) { 6648 unsigned long check = pfn + iter; 6649 6650 if (!pfn_valid_within(check)) 6651 continue; 6652 6653 page = pfn_to_page(check); 6654 6655 /* 6656 * Hugepages are not in LRU lists, but they're movable. 6657 * We need not scan over tail pages bacause we don't 6658 * handle each tail page individually in migration. 6659 */ 6660 if (PageHuge(page)) { 6661 iter = round_up(iter + 1, 1<<compound_order(page)) - 1; 6662 continue; 6663 } 6664 6665 /* 6666 * We can't use page_count without pin a page 6667 * because another CPU can free compound page. 6668 * This check already skips compound tails of THP 6669 * because their page->_count is zero at all time. 6670 */ 6671 if (!atomic_read(&page->_count)) { 6672 if (PageBuddy(page)) 6673 iter += (1 << page_order(page)) - 1; 6674 continue; 6675 } 6676 6677 /* 6678 * The HWPoisoned page may be not in buddy system, and 6679 * page_count() is not 0. 6680 */ 6681 if (skip_hwpoisoned_pages && PageHWPoison(page)) 6682 continue; 6683 6684 if (!PageLRU(page)) 6685 found++; 6686 /* 6687 * If there are RECLAIMABLE pages, we need to check 6688 * it. But now, memory offline itself doesn't call 6689 * shrink_node_slabs() and it still to be fixed. 6690 */ 6691 /* 6692 * If the page is not RAM, page_count()should be 0. 6693 * we don't need more check. This is an _used_ not-movable page. 6694 * 6695 * The problematic thing here is PG_reserved pages. PG_reserved 6696 * is set to both of a memory hole page and a _used_ kernel 6697 * page at boot. 6698 */ 6699 if (found > count) 6700 return true; 6701 } 6702 return false; 6703 } 6704 6705 bool is_pageblock_removable_nolock(struct page *page) 6706 { 6707 struct zone *zone; 6708 unsigned long pfn; 6709 6710 /* 6711 * We have to be careful here because we are iterating over memory 6712 * sections which are not zone aware so we might end up outside of 6713 * the zone but still within the section. 6714 * We have to take care about the node as well. If the node is offline 6715 * its NODE_DATA will be NULL - see page_zone. 6716 */ 6717 if (!node_online(page_to_nid(page))) 6718 return false; 6719 6720 zone = page_zone(page); 6721 pfn = page_to_pfn(page); 6722 if (!zone_spans_pfn(zone, pfn)) 6723 return false; 6724 6725 return !has_unmovable_pages(zone, page, 0, true); 6726 } 6727 6728 #ifdef CONFIG_CMA 6729 6730 static unsigned long pfn_max_align_down(unsigned long pfn) 6731 { 6732 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES, 6733 pageblock_nr_pages) - 1); 6734 } 6735 6736 static unsigned long pfn_max_align_up(unsigned long pfn) 6737 { 6738 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES, 6739 pageblock_nr_pages)); 6740 } 6741 6742 /* [start, end) must belong to a single zone. */ 6743 static int __alloc_contig_migrate_range(struct compact_control *cc, 6744 unsigned long start, unsigned long end) 6745 { 6746 /* This function is based on compact_zone() from compaction.c. */ 6747 unsigned long nr_reclaimed; 6748 unsigned long pfn = start; 6749 unsigned int tries = 0; 6750 int ret = 0; 6751 6752 migrate_prep(); 6753 6754 while (pfn < end || !list_empty(&cc->migratepages)) { 6755 if (fatal_signal_pending(current)) { 6756 ret = -EINTR; 6757 break; 6758 } 6759 6760 if (list_empty(&cc->migratepages)) { 6761 cc->nr_migratepages = 0; 6762 pfn = isolate_migratepages_range(cc, pfn, end); 6763 if (!pfn) { 6764 ret = -EINTR; 6765 break; 6766 } 6767 tries = 0; 6768 } else if (++tries == 5) { 6769 ret = ret < 0 ? ret : -EBUSY; 6770 break; 6771 } 6772 6773 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone, 6774 &cc->migratepages); 6775 cc->nr_migratepages -= nr_reclaimed; 6776 6777 ret = migrate_pages(&cc->migratepages, alloc_migrate_target, 6778 NULL, 0, cc->mode, MR_CMA); 6779 } 6780 if (ret < 0) { 6781 putback_movable_pages(&cc->migratepages); 6782 return ret; 6783 } 6784 return 0; 6785 } 6786 6787 /** 6788 * alloc_contig_range() -- tries to allocate given range of pages 6789 * @start: start PFN to allocate 6790 * @end: one-past-the-last PFN to allocate 6791 * @migratetype: migratetype of the underlaying pageblocks (either 6792 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks 6793 * in range must have the same migratetype and it must 6794 * be either of the two. 6795 * 6796 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES 6797 * aligned, however it's the caller's responsibility to guarantee that 6798 * we are the only thread that changes migrate type of pageblocks the 6799 * pages fall in. 6800 * 6801 * The PFN range must belong to a single zone. 6802 * 6803 * Returns zero on success or negative error code. On success all 6804 * pages which PFN is in [start, end) are allocated for the caller and 6805 * need to be freed with free_contig_range(). 6806 */ 6807 int alloc_contig_range(unsigned long start, unsigned long end, 6808 unsigned migratetype) 6809 { 6810 unsigned long outer_start, outer_end; 6811 int ret = 0, order; 6812 6813 struct compact_control cc = { 6814 .nr_migratepages = 0, 6815 .order = -1, 6816 .zone = page_zone(pfn_to_page(start)), 6817 .mode = MIGRATE_SYNC, 6818 .ignore_skip_hint = true, 6819 }; 6820 INIT_LIST_HEAD(&cc.migratepages); 6821 6822 /* 6823 * What we do here is we mark all pageblocks in range as 6824 * MIGRATE_ISOLATE. Because pageblock and max order pages may 6825 * have different sizes, and due to the way page allocator 6826 * work, we align the range to biggest of the two pages so 6827 * that page allocator won't try to merge buddies from 6828 * different pageblocks and change MIGRATE_ISOLATE to some 6829 * other migration type. 6830 * 6831 * Once the pageblocks are marked as MIGRATE_ISOLATE, we 6832 * migrate the pages from an unaligned range (ie. pages that 6833 * we are interested in). This will put all the pages in 6834 * range back to page allocator as MIGRATE_ISOLATE. 6835 * 6836 * When this is done, we take the pages in range from page 6837 * allocator removing them from the buddy system. This way 6838 * page allocator will never consider using them. 6839 * 6840 * This lets us mark the pageblocks back as 6841 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the 6842 * aligned range but not in the unaligned, original range are 6843 * put back to page allocator so that buddy can use them. 6844 */ 6845 6846 ret = start_isolate_page_range(pfn_max_align_down(start), 6847 pfn_max_align_up(end), migratetype, 6848 false); 6849 if (ret) 6850 return ret; 6851 6852 ret = __alloc_contig_migrate_range(&cc, start, end); 6853 if (ret) 6854 goto done; 6855 6856 /* 6857 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES 6858 * aligned blocks that are marked as MIGRATE_ISOLATE. What's 6859 * more, all pages in [start, end) are free in page allocator. 6860 * What we are going to do is to allocate all pages from 6861 * [start, end) (that is remove them from page allocator). 6862 * 6863 * The only problem is that pages at the beginning and at the 6864 * end of interesting range may be not aligned with pages that 6865 * page allocator holds, ie. they can be part of higher order 6866 * pages. Because of this, we reserve the bigger range and 6867 * once this is done free the pages we are not interested in. 6868 * 6869 * We don't have to hold zone->lock here because the pages are 6870 * isolated thus they won't get removed from buddy. 6871 */ 6872 6873 lru_add_drain_all(); 6874 drain_all_pages(cc.zone); 6875 6876 order = 0; 6877 outer_start = start; 6878 while (!PageBuddy(pfn_to_page(outer_start))) { 6879 if (++order >= MAX_ORDER) { 6880 ret = -EBUSY; 6881 goto done; 6882 } 6883 outer_start &= ~0UL << order; 6884 } 6885 6886 /* Make sure the range is really isolated. */ 6887 if (test_pages_isolated(outer_start, end, false)) { 6888 pr_info("%s: [%lx, %lx) PFNs busy\n", 6889 __func__, outer_start, end); 6890 ret = -EBUSY; 6891 goto done; 6892 } 6893 6894 /* Grab isolated pages from freelists. */ 6895 outer_end = isolate_freepages_range(&cc, outer_start, end); 6896 if (!outer_end) { 6897 ret = -EBUSY; 6898 goto done; 6899 } 6900 6901 /* Free head and tail (if any) */ 6902 if (start != outer_start) 6903 free_contig_range(outer_start, start - outer_start); 6904 if (end != outer_end) 6905 free_contig_range(end, outer_end - end); 6906 6907 done: 6908 undo_isolate_page_range(pfn_max_align_down(start), 6909 pfn_max_align_up(end), migratetype); 6910 return ret; 6911 } 6912 6913 void free_contig_range(unsigned long pfn, unsigned nr_pages) 6914 { 6915 unsigned int count = 0; 6916 6917 for (; nr_pages--; pfn++) { 6918 struct page *page = pfn_to_page(pfn); 6919 6920 count += page_count(page) != 1; 6921 __free_page(page); 6922 } 6923 WARN(count != 0, "%d pages are still in use!\n", count); 6924 } 6925 #endif 6926 6927 #ifdef CONFIG_MEMORY_HOTPLUG 6928 /* 6929 * The zone indicated has a new number of managed_pages; batch sizes and percpu 6930 * page high values need to be recalulated. 6931 */ 6932 void __meminit zone_pcp_update(struct zone *zone) 6933 { 6934 unsigned cpu; 6935 mutex_lock(&pcp_batch_high_lock); 6936 for_each_possible_cpu(cpu) 6937 pageset_set_high_and_batch(zone, 6938 per_cpu_ptr(zone->pageset, cpu)); 6939 mutex_unlock(&pcp_batch_high_lock); 6940 } 6941 #endif 6942 6943 void zone_pcp_reset(struct zone *zone) 6944 { 6945 unsigned long flags; 6946 int cpu; 6947 struct per_cpu_pageset *pset; 6948 6949 /* avoid races with drain_pages() */ 6950 local_irq_save(flags); 6951 if (zone->pageset != &boot_pageset) { 6952 for_each_online_cpu(cpu) { 6953 pset = per_cpu_ptr(zone->pageset, cpu); 6954 drain_zonestat(zone, pset); 6955 } 6956 free_percpu(zone->pageset); 6957 zone->pageset = &boot_pageset; 6958 } 6959 local_irq_restore(flags); 6960 } 6961 6962 #ifdef CONFIG_MEMORY_HOTREMOVE 6963 /* 6964 * All pages in the range must be isolated before calling this. 6965 */ 6966 void 6967 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) 6968 { 6969 struct page *page; 6970 struct zone *zone; 6971 unsigned int order, i; 6972 unsigned long pfn; 6973 unsigned long flags; 6974 /* find the first valid pfn */ 6975 for (pfn = start_pfn; pfn < end_pfn; pfn++) 6976 if (pfn_valid(pfn)) 6977 break; 6978 if (pfn == end_pfn) 6979 return; 6980 zone = page_zone(pfn_to_page(pfn)); 6981 spin_lock_irqsave(&zone->lock, flags); 6982 pfn = start_pfn; 6983 while (pfn < end_pfn) { 6984 if (!pfn_valid(pfn)) { 6985 pfn++; 6986 continue; 6987 } 6988 page = pfn_to_page(pfn); 6989 /* 6990 * The HWPoisoned page may be not in buddy system, and 6991 * page_count() is not 0. 6992 */ 6993 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) { 6994 pfn++; 6995 SetPageReserved(page); 6996 continue; 6997 } 6998 6999 BUG_ON(page_count(page)); 7000 BUG_ON(!PageBuddy(page)); 7001 order = page_order(page); 7002 #ifdef CONFIG_DEBUG_VM 7003 printk(KERN_INFO "remove from free list %lx %d %lx\n", 7004 pfn, 1 << order, end_pfn); 7005 #endif 7006 list_del(&page->lru); 7007 rmv_page_order(page); 7008 zone->free_area[order].nr_free--; 7009 for (i = 0; i < (1 << order); i++) 7010 SetPageReserved((page+i)); 7011 pfn += (1 << order); 7012 } 7013 spin_unlock_irqrestore(&zone->lock, flags); 7014 } 7015 #endif 7016 7017 #ifdef CONFIG_MEMORY_FAILURE 7018 bool is_free_buddy_page(struct page *page) 7019 { 7020 struct zone *zone = page_zone(page); 7021 unsigned long pfn = page_to_pfn(page); 7022 unsigned long flags; 7023 unsigned int order; 7024 7025 spin_lock_irqsave(&zone->lock, flags); 7026 for (order = 0; order < MAX_ORDER; order++) { 7027 struct page *page_head = page - (pfn & ((1 << order) - 1)); 7028 7029 if (PageBuddy(page_head) && page_order(page_head) >= order) 7030 break; 7031 } 7032 spin_unlock_irqrestore(&zone->lock, flags); 7033 7034 return order < MAX_ORDER; 7035 } 7036 #endif 7037