1 /* 2 * linux/mm/page_alloc.c 3 * 4 * Manages the free list, the system allocates free pages here. 5 * Note that kmalloc() lives in slab.c 6 * 7 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 8 * Swap reorganised 29.12.95, Stephen Tweedie 9 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 10 * Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999 11 * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999 12 * Zone balancing, Kanoj Sarcar, SGI, Jan 2000 13 * Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002 14 * (lots of bits borrowed from Ingo Molnar & Andrew Morton) 15 */ 16 17 #include <linux/stddef.h> 18 #include <linux/mm.h> 19 #include <linux/swap.h> 20 #include <linux/interrupt.h> 21 #include <linux/pagemap.h> 22 #include <linux/jiffies.h> 23 #include <linux/bootmem.h> 24 #include <linux/memblock.h> 25 #include <linux/compiler.h> 26 #include <linux/kernel.h> 27 #include <linux/kmemcheck.h> 28 #include <linux/module.h> 29 #include <linux/suspend.h> 30 #include <linux/pagevec.h> 31 #include <linux/blkdev.h> 32 #include <linux/slab.h> 33 #include <linux/ratelimit.h> 34 #include <linux/oom.h> 35 #include <linux/notifier.h> 36 #include <linux/topology.h> 37 #include <linux/sysctl.h> 38 #include <linux/cpu.h> 39 #include <linux/cpuset.h> 40 #include <linux/memory_hotplug.h> 41 #include <linux/nodemask.h> 42 #include <linux/vmalloc.h> 43 #include <linux/vmstat.h> 44 #include <linux/mempolicy.h> 45 #include <linux/stop_machine.h> 46 #include <linux/sort.h> 47 #include <linux/pfn.h> 48 #include <linux/backing-dev.h> 49 #include <linux/fault-inject.h> 50 #include <linux/page-isolation.h> 51 #include <linux/page_ext.h> 52 #include <linux/debugobjects.h> 53 #include <linux/kmemleak.h> 54 #include <linux/compaction.h> 55 #include <trace/events/kmem.h> 56 #include <linux/prefetch.h> 57 #include <linux/mm_inline.h> 58 #include <linux/migrate.h> 59 #include <linux/page_ext.h> 60 #include <linux/hugetlb.h> 61 #include <linux/sched/rt.h> 62 #include <linux/page_owner.h> 63 64 #include <asm/sections.h> 65 #include <asm/tlbflush.h> 66 #include <asm/div64.h> 67 #include "internal.h" 68 69 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */ 70 static DEFINE_MUTEX(pcp_batch_high_lock); 71 #define MIN_PERCPU_PAGELIST_FRACTION (8) 72 73 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID 74 DEFINE_PER_CPU(int, numa_node); 75 EXPORT_PER_CPU_SYMBOL(numa_node); 76 #endif 77 78 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 79 /* 80 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly. 81 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined. 82 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem() 83 * defined in <linux/topology.h>. 84 */ 85 DEFINE_PER_CPU(int, _numa_mem_); /* Kernel "local memory" node */ 86 EXPORT_PER_CPU_SYMBOL(_numa_mem_); 87 int _node_numa_mem_[MAX_NUMNODES]; 88 #endif 89 90 /* 91 * Array of node states. 92 */ 93 nodemask_t node_states[NR_NODE_STATES] __read_mostly = { 94 [N_POSSIBLE] = NODE_MASK_ALL, 95 [N_ONLINE] = { { [0] = 1UL } }, 96 #ifndef CONFIG_NUMA 97 [N_NORMAL_MEMORY] = { { [0] = 1UL } }, 98 #ifdef CONFIG_HIGHMEM 99 [N_HIGH_MEMORY] = { { [0] = 1UL } }, 100 #endif 101 #ifdef CONFIG_MOVABLE_NODE 102 [N_MEMORY] = { { [0] = 1UL } }, 103 #endif 104 [N_CPU] = { { [0] = 1UL } }, 105 #endif /* NUMA */ 106 }; 107 EXPORT_SYMBOL(node_states); 108 109 /* Protect totalram_pages and zone->managed_pages */ 110 static DEFINE_SPINLOCK(managed_page_count_lock); 111 112 unsigned long totalram_pages __read_mostly; 113 unsigned long totalreserve_pages __read_mostly; 114 unsigned long totalcma_pages __read_mostly; 115 /* 116 * When calculating the number of globally allowed dirty pages, there 117 * is a certain number of per-zone reserves that should not be 118 * considered dirtyable memory. This is the sum of those reserves 119 * over all existing zones that contribute dirtyable memory. 120 */ 121 unsigned long dirty_balance_reserve __read_mostly; 122 123 int percpu_pagelist_fraction; 124 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; 125 126 #ifdef CONFIG_PM_SLEEP 127 /* 128 * The following functions are used by the suspend/hibernate code to temporarily 129 * change gfp_allowed_mask in order to avoid using I/O during memory allocations 130 * while devices are suspended. To avoid races with the suspend/hibernate code, 131 * they should always be called with pm_mutex held (gfp_allowed_mask also should 132 * only be modified with pm_mutex held, unless the suspend/hibernate code is 133 * guaranteed not to run in parallel with that modification). 134 */ 135 136 static gfp_t saved_gfp_mask; 137 138 void pm_restore_gfp_mask(void) 139 { 140 WARN_ON(!mutex_is_locked(&pm_mutex)); 141 if (saved_gfp_mask) { 142 gfp_allowed_mask = saved_gfp_mask; 143 saved_gfp_mask = 0; 144 } 145 } 146 147 void pm_restrict_gfp_mask(void) 148 { 149 WARN_ON(!mutex_is_locked(&pm_mutex)); 150 WARN_ON(saved_gfp_mask); 151 saved_gfp_mask = gfp_allowed_mask; 152 gfp_allowed_mask &= ~GFP_IOFS; 153 } 154 155 bool pm_suspended_storage(void) 156 { 157 if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS) 158 return false; 159 return true; 160 } 161 #endif /* CONFIG_PM_SLEEP */ 162 163 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 164 int pageblock_order __read_mostly; 165 #endif 166 167 static void __free_pages_ok(struct page *page, unsigned int order); 168 169 /* 170 * results with 256, 32 in the lowmem_reserve sysctl: 171 * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) 172 * 1G machine -> (16M dma, 784M normal, 224M high) 173 * NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA 174 * HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL 175 * HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA 176 * 177 * TBD: should special case ZONE_DMA32 machines here - in those we normally 178 * don't need any ZONE_NORMAL reservation 179 */ 180 int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { 181 #ifdef CONFIG_ZONE_DMA 182 256, 183 #endif 184 #ifdef CONFIG_ZONE_DMA32 185 256, 186 #endif 187 #ifdef CONFIG_HIGHMEM 188 32, 189 #endif 190 32, 191 }; 192 193 EXPORT_SYMBOL(totalram_pages); 194 195 static char * const zone_names[MAX_NR_ZONES] = { 196 #ifdef CONFIG_ZONE_DMA 197 "DMA", 198 #endif 199 #ifdef CONFIG_ZONE_DMA32 200 "DMA32", 201 #endif 202 "Normal", 203 #ifdef CONFIG_HIGHMEM 204 "HighMem", 205 #endif 206 "Movable", 207 }; 208 209 int min_free_kbytes = 1024; 210 int user_min_free_kbytes = -1; 211 212 static unsigned long __meminitdata nr_kernel_pages; 213 static unsigned long __meminitdata nr_all_pages; 214 static unsigned long __meminitdata dma_reserve; 215 216 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 217 static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES]; 218 static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; 219 static unsigned long __initdata required_kernelcore; 220 static unsigned long __initdata required_movablecore; 221 static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES]; 222 223 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ 224 int movable_zone; 225 EXPORT_SYMBOL(movable_zone); 226 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 227 228 #if MAX_NUMNODES > 1 229 int nr_node_ids __read_mostly = MAX_NUMNODES; 230 int nr_online_nodes __read_mostly = 1; 231 EXPORT_SYMBOL(nr_node_ids); 232 EXPORT_SYMBOL(nr_online_nodes); 233 #endif 234 235 int page_group_by_mobility_disabled __read_mostly; 236 237 void set_pageblock_migratetype(struct page *page, int migratetype) 238 { 239 if (unlikely(page_group_by_mobility_disabled && 240 migratetype < MIGRATE_PCPTYPES)) 241 migratetype = MIGRATE_UNMOVABLE; 242 243 set_pageblock_flags_group(page, (unsigned long)migratetype, 244 PB_migrate, PB_migrate_end); 245 } 246 247 bool oom_killer_disabled __read_mostly; 248 249 #ifdef CONFIG_DEBUG_VM 250 static int page_outside_zone_boundaries(struct zone *zone, struct page *page) 251 { 252 int ret = 0; 253 unsigned seq; 254 unsigned long pfn = page_to_pfn(page); 255 unsigned long sp, start_pfn; 256 257 do { 258 seq = zone_span_seqbegin(zone); 259 start_pfn = zone->zone_start_pfn; 260 sp = zone->spanned_pages; 261 if (!zone_spans_pfn(zone, pfn)) 262 ret = 1; 263 } while (zone_span_seqretry(zone, seq)); 264 265 if (ret) 266 pr_err("page 0x%lx outside node %d zone %s [ 0x%lx - 0x%lx ]\n", 267 pfn, zone_to_nid(zone), zone->name, 268 start_pfn, start_pfn + sp); 269 270 return ret; 271 } 272 273 static int page_is_consistent(struct zone *zone, struct page *page) 274 { 275 if (!pfn_valid_within(page_to_pfn(page))) 276 return 0; 277 if (zone != page_zone(page)) 278 return 0; 279 280 return 1; 281 } 282 /* 283 * Temporary debugging check for pages not lying within a given zone. 284 */ 285 static int bad_range(struct zone *zone, struct page *page) 286 { 287 if (page_outside_zone_boundaries(zone, page)) 288 return 1; 289 if (!page_is_consistent(zone, page)) 290 return 1; 291 292 return 0; 293 } 294 #else 295 static inline int bad_range(struct zone *zone, struct page *page) 296 { 297 return 0; 298 } 299 #endif 300 301 static void bad_page(struct page *page, const char *reason, 302 unsigned long bad_flags) 303 { 304 static unsigned long resume; 305 static unsigned long nr_shown; 306 static unsigned long nr_unshown; 307 308 /* Don't complain about poisoned pages */ 309 if (PageHWPoison(page)) { 310 page_mapcount_reset(page); /* remove PageBuddy */ 311 return; 312 } 313 314 /* 315 * Allow a burst of 60 reports, then keep quiet for that minute; 316 * or allow a steady drip of one report per second. 317 */ 318 if (nr_shown == 60) { 319 if (time_before(jiffies, resume)) { 320 nr_unshown++; 321 goto out; 322 } 323 if (nr_unshown) { 324 printk(KERN_ALERT 325 "BUG: Bad page state: %lu messages suppressed\n", 326 nr_unshown); 327 nr_unshown = 0; 328 } 329 nr_shown = 0; 330 } 331 if (nr_shown++ == 0) 332 resume = jiffies + 60 * HZ; 333 334 printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n", 335 current->comm, page_to_pfn(page)); 336 dump_page_badflags(page, reason, bad_flags); 337 338 print_modules(); 339 dump_stack(); 340 out: 341 /* Leave bad fields for debug, except PageBuddy could make trouble */ 342 page_mapcount_reset(page); /* remove PageBuddy */ 343 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); 344 } 345 346 /* 347 * Higher-order pages are called "compound pages". They are structured thusly: 348 * 349 * The first PAGE_SIZE page is called the "head page". 350 * 351 * The remaining PAGE_SIZE pages are called "tail pages". 352 * 353 * All pages have PG_compound set. All tail pages have their ->first_page 354 * pointing at the head page. 355 * 356 * The first tail page's ->lru.next holds the address of the compound page's 357 * put_page() function. Its ->lru.prev holds the order of allocation. 358 * This usage means that zero-order pages may not be compound. 359 */ 360 361 static void free_compound_page(struct page *page) 362 { 363 __free_pages_ok(page, compound_order(page)); 364 } 365 366 void prep_compound_page(struct page *page, unsigned long order) 367 { 368 int i; 369 int nr_pages = 1 << order; 370 371 set_compound_page_dtor(page, free_compound_page); 372 set_compound_order(page, order); 373 __SetPageHead(page); 374 for (i = 1; i < nr_pages; i++) { 375 struct page *p = page + i; 376 set_page_count(p, 0); 377 p->first_page = page; 378 /* Make sure p->first_page is always valid for PageTail() */ 379 smp_wmb(); 380 __SetPageTail(p); 381 } 382 } 383 384 /* update __split_huge_page_refcount if you change this function */ 385 static int destroy_compound_page(struct page *page, unsigned long order) 386 { 387 int i; 388 int nr_pages = 1 << order; 389 int bad = 0; 390 391 if (unlikely(compound_order(page) != order)) { 392 bad_page(page, "wrong compound order", 0); 393 bad++; 394 } 395 396 __ClearPageHead(page); 397 398 for (i = 1; i < nr_pages; i++) { 399 struct page *p = page + i; 400 401 if (unlikely(!PageTail(p))) { 402 bad_page(page, "PageTail not set", 0); 403 bad++; 404 } else if (unlikely(p->first_page != page)) { 405 bad_page(page, "first_page not consistent", 0); 406 bad++; 407 } 408 __ClearPageTail(p); 409 } 410 411 return bad; 412 } 413 414 static inline void prep_zero_page(struct page *page, unsigned int order, 415 gfp_t gfp_flags) 416 { 417 int i; 418 419 /* 420 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO 421 * and __GFP_HIGHMEM from hard or soft interrupt context. 422 */ 423 VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt()); 424 for (i = 0; i < (1 << order); i++) 425 clear_highpage(page + i); 426 } 427 428 #ifdef CONFIG_DEBUG_PAGEALLOC 429 unsigned int _debug_guardpage_minorder; 430 bool _debug_pagealloc_enabled __read_mostly; 431 bool _debug_guardpage_enabled __read_mostly; 432 433 static int __init early_debug_pagealloc(char *buf) 434 { 435 if (!buf) 436 return -EINVAL; 437 438 if (strcmp(buf, "on") == 0) 439 _debug_pagealloc_enabled = true; 440 441 return 0; 442 } 443 early_param("debug_pagealloc", early_debug_pagealloc); 444 445 static bool need_debug_guardpage(void) 446 { 447 /* If we don't use debug_pagealloc, we don't need guard page */ 448 if (!debug_pagealloc_enabled()) 449 return false; 450 451 return true; 452 } 453 454 static void init_debug_guardpage(void) 455 { 456 if (!debug_pagealloc_enabled()) 457 return; 458 459 _debug_guardpage_enabled = true; 460 } 461 462 struct page_ext_operations debug_guardpage_ops = { 463 .need = need_debug_guardpage, 464 .init = init_debug_guardpage, 465 }; 466 467 static int __init debug_guardpage_minorder_setup(char *buf) 468 { 469 unsigned long res; 470 471 if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) { 472 printk(KERN_ERR "Bad debug_guardpage_minorder value\n"); 473 return 0; 474 } 475 _debug_guardpage_minorder = res; 476 printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res); 477 return 0; 478 } 479 __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup); 480 481 static inline void set_page_guard(struct zone *zone, struct page *page, 482 unsigned int order, int migratetype) 483 { 484 struct page_ext *page_ext; 485 486 if (!debug_guardpage_enabled()) 487 return; 488 489 page_ext = lookup_page_ext(page); 490 __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags); 491 492 INIT_LIST_HEAD(&page->lru); 493 set_page_private(page, order); 494 /* Guard pages are not available for any usage */ 495 __mod_zone_freepage_state(zone, -(1 << order), migratetype); 496 } 497 498 static inline void clear_page_guard(struct zone *zone, struct page *page, 499 unsigned int order, int migratetype) 500 { 501 struct page_ext *page_ext; 502 503 if (!debug_guardpage_enabled()) 504 return; 505 506 page_ext = lookup_page_ext(page); 507 __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags); 508 509 set_page_private(page, 0); 510 if (!is_migrate_isolate(migratetype)) 511 __mod_zone_freepage_state(zone, (1 << order), migratetype); 512 } 513 #else 514 struct page_ext_operations debug_guardpage_ops = { NULL, }; 515 static inline void set_page_guard(struct zone *zone, struct page *page, 516 unsigned int order, int migratetype) {} 517 static inline void clear_page_guard(struct zone *zone, struct page *page, 518 unsigned int order, int migratetype) {} 519 #endif 520 521 static inline void set_page_order(struct page *page, unsigned int order) 522 { 523 set_page_private(page, order); 524 __SetPageBuddy(page); 525 } 526 527 static inline void rmv_page_order(struct page *page) 528 { 529 __ClearPageBuddy(page); 530 set_page_private(page, 0); 531 } 532 533 /* 534 * This function checks whether a page is free && is the buddy 535 * we can do coalesce a page and its buddy if 536 * (a) the buddy is not in a hole && 537 * (b) the buddy is in the buddy system && 538 * (c) a page and its buddy have the same order && 539 * (d) a page and its buddy are in the same zone. 540 * 541 * For recording whether a page is in the buddy system, we set ->_mapcount 542 * PAGE_BUDDY_MAPCOUNT_VALUE. 543 * Setting, clearing, and testing _mapcount PAGE_BUDDY_MAPCOUNT_VALUE is 544 * serialized by zone->lock. 545 * 546 * For recording page's order, we use page_private(page). 547 */ 548 static inline int page_is_buddy(struct page *page, struct page *buddy, 549 unsigned int order) 550 { 551 if (!pfn_valid_within(page_to_pfn(buddy))) 552 return 0; 553 554 if (page_is_guard(buddy) && page_order(buddy) == order) { 555 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); 556 557 if (page_zone_id(page) != page_zone_id(buddy)) 558 return 0; 559 560 return 1; 561 } 562 563 if (PageBuddy(buddy) && page_order(buddy) == order) { 564 VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); 565 566 /* 567 * zone check is done late to avoid uselessly 568 * calculating zone/node ids for pages that could 569 * never merge. 570 */ 571 if (page_zone_id(page) != page_zone_id(buddy)) 572 return 0; 573 574 return 1; 575 } 576 return 0; 577 } 578 579 /* 580 * Freeing function for a buddy system allocator. 581 * 582 * The concept of a buddy system is to maintain direct-mapped table 583 * (containing bit values) for memory blocks of various "orders". 584 * The bottom level table contains the map for the smallest allocatable 585 * units of memory (here, pages), and each level above it describes 586 * pairs of units from the levels below, hence, "buddies". 587 * At a high level, all that happens here is marking the table entry 588 * at the bottom level available, and propagating the changes upward 589 * as necessary, plus some accounting needed to play nicely with other 590 * parts of the VM system. 591 * At each level, we keep a list of pages, which are heads of continuous 592 * free pages of length of (1 << order) and marked with _mapcount 593 * PAGE_BUDDY_MAPCOUNT_VALUE. Page's order is recorded in page_private(page) 594 * field. 595 * So when we are allocating or freeing one, we can derive the state of the 596 * other. That is, if we allocate a small block, and both were 597 * free, the remainder of the region must be split into blocks. 598 * If a block is freed, and its buddy is also free, then this 599 * triggers coalescing into a block of larger size. 600 * 601 * -- nyc 602 */ 603 604 static inline void __free_one_page(struct page *page, 605 unsigned long pfn, 606 struct zone *zone, unsigned int order, 607 int migratetype) 608 { 609 unsigned long page_idx; 610 unsigned long combined_idx; 611 unsigned long uninitialized_var(buddy_idx); 612 struct page *buddy; 613 int max_order = MAX_ORDER; 614 615 VM_BUG_ON(!zone_is_initialized(zone)); 616 617 if (unlikely(PageCompound(page))) 618 if (unlikely(destroy_compound_page(page, order))) 619 return; 620 621 VM_BUG_ON(migratetype == -1); 622 if (is_migrate_isolate(migratetype)) { 623 /* 624 * We restrict max order of merging to prevent merge 625 * between freepages on isolate pageblock and normal 626 * pageblock. Without this, pageblock isolation 627 * could cause incorrect freepage accounting. 628 */ 629 max_order = min(MAX_ORDER, pageblock_order + 1); 630 } else { 631 __mod_zone_freepage_state(zone, 1 << order, migratetype); 632 } 633 634 page_idx = pfn & ((1 << max_order) - 1); 635 636 VM_BUG_ON_PAGE(page_idx & ((1 << order) - 1), page); 637 VM_BUG_ON_PAGE(bad_range(zone, page), page); 638 639 while (order < max_order - 1) { 640 buddy_idx = __find_buddy_index(page_idx, order); 641 buddy = page + (buddy_idx - page_idx); 642 if (!page_is_buddy(page, buddy, order)) 643 break; 644 /* 645 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page, 646 * merge with it and move up one order. 647 */ 648 if (page_is_guard(buddy)) { 649 clear_page_guard(zone, buddy, order, migratetype); 650 } else { 651 list_del(&buddy->lru); 652 zone->free_area[order].nr_free--; 653 rmv_page_order(buddy); 654 } 655 combined_idx = buddy_idx & page_idx; 656 page = page + (combined_idx - page_idx); 657 page_idx = combined_idx; 658 order++; 659 } 660 set_page_order(page, order); 661 662 /* 663 * If this is not the largest possible page, check if the buddy 664 * of the next-highest order is free. If it is, it's possible 665 * that pages are being freed that will coalesce soon. In case, 666 * that is happening, add the free page to the tail of the list 667 * so it's less likely to be used soon and more likely to be merged 668 * as a higher order page 669 */ 670 if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) { 671 struct page *higher_page, *higher_buddy; 672 combined_idx = buddy_idx & page_idx; 673 higher_page = page + (combined_idx - page_idx); 674 buddy_idx = __find_buddy_index(combined_idx, order + 1); 675 higher_buddy = higher_page + (buddy_idx - combined_idx); 676 if (page_is_buddy(higher_page, higher_buddy, order + 1)) { 677 list_add_tail(&page->lru, 678 &zone->free_area[order].free_list[migratetype]); 679 goto out; 680 } 681 } 682 683 list_add(&page->lru, &zone->free_area[order].free_list[migratetype]); 684 out: 685 zone->free_area[order].nr_free++; 686 } 687 688 static inline int free_pages_check(struct page *page) 689 { 690 const char *bad_reason = NULL; 691 unsigned long bad_flags = 0; 692 693 if (unlikely(page_mapcount(page))) 694 bad_reason = "nonzero mapcount"; 695 if (unlikely(page->mapping != NULL)) 696 bad_reason = "non-NULL mapping"; 697 if (unlikely(atomic_read(&page->_count) != 0)) 698 bad_reason = "nonzero _count"; 699 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) { 700 bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set"; 701 bad_flags = PAGE_FLAGS_CHECK_AT_FREE; 702 } 703 #ifdef CONFIG_MEMCG 704 if (unlikely(page->mem_cgroup)) 705 bad_reason = "page still charged to cgroup"; 706 #endif 707 if (unlikely(bad_reason)) { 708 bad_page(page, bad_reason, bad_flags); 709 return 1; 710 } 711 page_cpupid_reset_last(page); 712 if (page->flags & PAGE_FLAGS_CHECK_AT_PREP) 713 page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; 714 return 0; 715 } 716 717 /* 718 * Frees a number of pages from the PCP lists 719 * Assumes all pages on list are in same zone, and of same order. 720 * count is the number of pages to free. 721 * 722 * If the zone was previously in an "all pages pinned" state then look to 723 * see if this freeing clears that state. 724 * 725 * And clear the zone's pages_scanned counter, to hold off the "all pages are 726 * pinned" detection logic. 727 */ 728 static void free_pcppages_bulk(struct zone *zone, int count, 729 struct per_cpu_pages *pcp) 730 { 731 int migratetype = 0; 732 int batch_free = 0; 733 int to_free = count; 734 unsigned long nr_scanned; 735 736 spin_lock(&zone->lock); 737 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED); 738 if (nr_scanned) 739 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned); 740 741 while (to_free) { 742 struct page *page; 743 struct list_head *list; 744 745 /* 746 * Remove pages from lists in a round-robin fashion. A 747 * batch_free count is maintained that is incremented when an 748 * empty list is encountered. This is so more pages are freed 749 * off fuller lists instead of spinning excessively around empty 750 * lists 751 */ 752 do { 753 batch_free++; 754 if (++migratetype == MIGRATE_PCPTYPES) 755 migratetype = 0; 756 list = &pcp->lists[migratetype]; 757 } while (list_empty(list)); 758 759 /* This is the only non-empty list. Free them all. */ 760 if (batch_free == MIGRATE_PCPTYPES) 761 batch_free = to_free; 762 763 do { 764 int mt; /* migratetype of the to-be-freed page */ 765 766 page = list_entry(list->prev, struct page, lru); 767 /* must delete as __free_one_page list manipulates */ 768 list_del(&page->lru); 769 mt = get_freepage_migratetype(page); 770 if (unlikely(has_isolate_pageblock(zone))) 771 mt = get_pageblock_migratetype(page); 772 773 /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */ 774 __free_one_page(page, page_to_pfn(page), zone, 0, mt); 775 trace_mm_page_pcpu_drain(page, 0, mt); 776 } while (--to_free && --batch_free && !list_empty(list)); 777 } 778 spin_unlock(&zone->lock); 779 } 780 781 static void free_one_page(struct zone *zone, 782 struct page *page, unsigned long pfn, 783 unsigned int order, 784 int migratetype) 785 { 786 unsigned long nr_scanned; 787 spin_lock(&zone->lock); 788 nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED); 789 if (nr_scanned) 790 __mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned); 791 792 if (unlikely(has_isolate_pageblock(zone) || 793 is_migrate_isolate(migratetype))) { 794 migratetype = get_pfnblock_migratetype(page, pfn); 795 } 796 __free_one_page(page, pfn, zone, order, migratetype); 797 spin_unlock(&zone->lock); 798 } 799 800 static bool free_pages_prepare(struct page *page, unsigned int order) 801 { 802 int i; 803 int bad = 0; 804 805 VM_BUG_ON_PAGE(PageTail(page), page); 806 VM_BUG_ON_PAGE(PageHead(page) && compound_order(page) != order, page); 807 808 trace_mm_page_free(page, order); 809 kmemcheck_free_shadow(page, order); 810 811 if (PageAnon(page)) 812 page->mapping = NULL; 813 for (i = 0; i < (1 << order); i++) 814 bad += free_pages_check(page + i); 815 if (bad) 816 return false; 817 818 reset_page_owner(page, order); 819 820 if (!PageHighMem(page)) { 821 debug_check_no_locks_freed(page_address(page), 822 PAGE_SIZE << order); 823 debug_check_no_obj_freed(page_address(page), 824 PAGE_SIZE << order); 825 } 826 arch_free_page(page, order); 827 kernel_map_pages(page, 1 << order, 0); 828 829 return true; 830 } 831 832 static void __free_pages_ok(struct page *page, unsigned int order) 833 { 834 unsigned long flags; 835 int migratetype; 836 unsigned long pfn = page_to_pfn(page); 837 838 if (!free_pages_prepare(page, order)) 839 return; 840 841 migratetype = get_pfnblock_migratetype(page, pfn); 842 local_irq_save(flags); 843 __count_vm_events(PGFREE, 1 << order); 844 set_freepage_migratetype(page, migratetype); 845 free_one_page(page_zone(page), page, pfn, order, migratetype); 846 local_irq_restore(flags); 847 } 848 849 void __init __free_pages_bootmem(struct page *page, unsigned int order) 850 { 851 unsigned int nr_pages = 1 << order; 852 struct page *p = page; 853 unsigned int loop; 854 855 prefetchw(p); 856 for (loop = 0; loop < (nr_pages - 1); loop++, p++) { 857 prefetchw(p + 1); 858 __ClearPageReserved(p); 859 set_page_count(p, 0); 860 } 861 __ClearPageReserved(p); 862 set_page_count(p, 0); 863 864 page_zone(page)->managed_pages += nr_pages; 865 set_page_refcounted(page); 866 __free_pages(page, order); 867 } 868 869 #ifdef CONFIG_CMA 870 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */ 871 void __init init_cma_reserved_pageblock(struct page *page) 872 { 873 unsigned i = pageblock_nr_pages; 874 struct page *p = page; 875 876 do { 877 __ClearPageReserved(p); 878 set_page_count(p, 0); 879 } while (++p, --i); 880 881 set_pageblock_migratetype(page, MIGRATE_CMA); 882 883 if (pageblock_order >= MAX_ORDER) { 884 i = pageblock_nr_pages; 885 p = page; 886 do { 887 set_page_refcounted(p); 888 __free_pages(p, MAX_ORDER - 1); 889 p += MAX_ORDER_NR_PAGES; 890 } while (i -= MAX_ORDER_NR_PAGES); 891 } else { 892 set_page_refcounted(page); 893 __free_pages(page, pageblock_order); 894 } 895 896 adjust_managed_page_count(page, pageblock_nr_pages); 897 } 898 #endif 899 900 /* 901 * The order of subdivision here is critical for the IO subsystem. 902 * Please do not alter this order without good reasons and regression 903 * testing. Specifically, as large blocks of memory are subdivided, 904 * the order in which smaller blocks are delivered depends on the order 905 * they're subdivided in this function. This is the primary factor 906 * influencing the order in which pages are delivered to the IO 907 * subsystem according to empirical testing, and this is also justified 908 * by considering the behavior of a buddy system containing a single 909 * large block of memory acted on by a series of small allocations. 910 * This behavior is a critical factor in sglist merging's success. 911 * 912 * -- nyc 913 */ 914 static inline void expand(struct zone *zone, struct page *page, 915 int low, int high, struct free_area *area, 916 int migratetype) 917 { 918 unsigned long size = 1 << high; 919 920 while (high > low) { 921 area--; 922 high--; 923 size >>= 1; 924 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]); 925 926 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) && 927 debug_guardpage_enabled() && 928 high < debug_guardpage_minorder()) { 929 /* 930 * Mark as guard pages (or page), that will allow to 931 * merge back to allocator when buddy will be freed. 932 * Corresponding page table entries will not be touched, 933 * pages will stay not present in virtual address space 934 */ 935 set_page_guard(zone, &page[size], high, migratetype); 936 continue; 937 } 938 list_add(&page[size].lru, &area->free_list[migratetype]); 939 area->nr_free++; 940 set_page_order(&page[size], high); 941 } 942 } 943 944 /* 945 * This page is about to be returned from the page allocator 946 */ 947 static inline int check_new_page(struct page *page) 948 { 949 const char *bad_reason = NULL; 950 unsigned long bad_flags = 0; 951 952 if (unlikely(page_mapcount(page))) 953 bad_reason = "nonzero mapcount"; 954 if (unlikely(page->mapping != NULL)) 955 bad_reason = "non-NULL mapping"; 956 if (unlikely(atomic_read(&page->_count) != 0)) 957 bad_reason = "nonzero _count"; 958 if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) { 959 bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set"; 960 bad_flags = PAGE_FLAGS_CHECK_AT_PREP; 961 } 962 #ifdef CONFIG_MEMCG 963 if (unlikely(page->mem_cgroup)) 964 bad_reason = "page still charged to cgroup"; 965 #endif 966 if (unlikely(bad_reason)) { 967 bad_page(page, bad_reason, bad_flags); 968 return 1; 969 } 970 return 0; 971 } 972 973 static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags) 974 { 975 int i; 976 977 for (i = 0; i < (1 << order); i++) { 978 struct page *p = page + i; 979 if (unlikely(check_new_page(p))) 980 return 1; 981 } 982 983 set_page_private(page, 0); 984 set_page_refcounted(page); 985 986 arch_alloc_page(page, order); 987 kernel_map_pages(page, 1 << order, 1); 988 989 if (gfp_flags & __GFP_ZERO) 990 prep_zero_page(page, order, gfp_flags); 991 992 if (order && (gfp_flags & __GFP_COMP)) 993 prep_compound_page(page, order); 994 995 set_page_owner(page, order, gfp_flags); 996 997 return 0; 998 } 999 1000 /* 1001 * Go through the free lists for the given migratetype and remove 1002 * the smallest available page from the freelists 1003 */ 1004 static inline 1005 struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, 1006 int migratetype) 1007 { 1008 unsigned int current_order; 1009 struct free_area *area; 1010 struct page *page; 1011 1012 /* Find a page of the appropriate size in the preferred list */ 1013 for (current_order = order; current_order < MAX_ORDER; ++current_order) { 1014 area = &(zone->free_area[current_order]); 1015 if (list_empty(&area->free_list[migratetype])) 1016 continue; 1017 1018 page = list_entry(area->free_list[migratetype].next, 1019 struct page, lru); 1020 list_del(&page->lru); 1021 rmv_page_order(page); 1022 area->nr_free--; 1023 expand(zone, page, order, current_order, area, migratetype); 1024 set_freepage_migratetype(page, migratetype); 1025 return page; 1026 } 1027 1028 return NULL; 1029 } 1030 1031 1032 /* 1033 * This array describes the order lists are fallen back to when 1034 * the free lists for the desirable migrate type are depleted 1035 */ 1036 static int fallbacks[MIGRATE_TYPES][4] = { 1037 [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 1038 [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, 1039 #ifdef CONFIG_CMA 1040 [MIGRATE_MOVABLE] = { MIGRATE_CMA, MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, 1041 [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */ 1042 #else 1043 [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, 1044 #endif 1045 [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */ 1046 #ifdef CONFIG_MEMORY_ISOLATION 1047 [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */ 1048 #endif 1049 }; 1050 1051 /* 1052 * Move the free pages in a range to the free lists of the requested type. 1053 * Note that start_page and end_pages are not aligned on a pageblock 1054 * boundary. If alignment is required, use move_freepages_block() 1055 */ 1056 int move_freepages(struct zone *zone, 1057 struct page *start_page, struct page *end_page, 1058 int migratetype) 1059 { 1060 struct page *page; 1061 unsigned long order; 1062 int pages_moved = 0; 1063 1064 #ifndef CONFIG_HOLES_IN_ZONE 1065 /* 1066 * page_zone is not safe to call in this context when 1067 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant 1068 * anyway as we check zone boundaries in move_freepages_block(). 1069 * Remove at a later date when no bug reports exist related to 1070 * grouping pages by mobility 1071 */ 1072 VM_BUG_ON(page_zone(start_page) != page_zone(end_page)); 1073 #endif 1074 1075 for (page = start_page; page <= end_page;) { 1076 /* Make sure we are not inadvertently changing nodes */ 1077 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page); 1078 1079 if (!pfn_valid_within(page_to_pfn(page))) { 1080 page++; 1081 continue; 1082 } 1083 1084 if (!PageBuddy(page)) { 1085 page++; 1086 continue; 1087 } 1088 1089 order = page_order(page); 1090 list_move(&page->lru, 1091 &zone->free_area[order].free_list[migratetype]); 1092 set_freepage_migratetype(page, migratetype); 1093 page += 1 << order; 1094 pages_moved += 1 << order; 1095 } 1096 1097 return pages_moved; 1098 } 1099 1100 int move_freepages_block(struct zone *zone, struct page *page, 1101 int migratetype) 1102 { 1103 unsigned long start_pfn, end_pfn; 1104 struct page *start_page, *end_page; 1105 1106 start_pfn = page_to_pfn(page); 1107 start_pfn = start_pfn & ~(pageblock_nr_pages-1); 1108 start_page = pfn_to_page(start_pfn); 1109 end_page = start_page + pageblock_nr_pages - 1; 1110 end_pfn = start_pfn + pageblock_nr_pages - 1; 1111 1112 /* Do not cross zone boundaries */ 1113 if (!zone_spans_pfn(zone, start_pfn)) 1114 start_page = page; 1115 if (!zone_spans_pfn(zone, end_pfn)) 1116 return 0; 1117 1118 return move_freepages(zone, start_page, end_page, migratetype); 1119 } 1120 1121 static void change_pageblock_range(struct page *pageblock_page, 1122 int start_order, int migratetype) 1123 { 1124 int nr_pageblocks = 1 << (start_order - pageblock_order); 1125 1126 while (nr_pageblocks--) { 1127 set_pageblock_migratetype(pageblock_page, migratetype); 1128 pageblock_page += pageblock_nr_pages; 1129 } 1130 } 1131 1132 /* 1133 * If breaking a large block of pages, move all free pages to the preferred 1134 * allocation list. If falling back for a reclaimable kernel allocation, be 1135 * more aggressive about taking ownership of free pages. 1136 * 1137 * On the other hand, never change migration type of MIGRATE_CMA pageblocks 1138 * nor move CMA pages to different free lists. We don't want unmovable pages 1139 * to be allocated from MIGRATE_CMA areas. 1140 * 1141 * Returns the new migratetype of the pageblock (or the same old migratetype 1142 * if it was unchanged). 1143 */ 1144 static int try_to_steal_freepages(struct zone *zone, struct page *page, 1145 int start_type, int fallback_type) 1146 { 1147 int current_order = page_order(page); 1148 1149 /* 1150 * When borrowing from MIGRATE_CMA, we need to release the excess 1151 * buddy pages to CMA itself. We also ensure the freepage_migratetype 1152 * is set to CMA so it is returned to the correct freelist in case 1153 * the page ends up being not actually allocated from the pcp lists. 1154 */ 1155 if (is_migrate_cma(fallback_type)) 1156 return fallback_type; 1157 1158 /* Take ownership for orders >= pageblock_order */ 1159 if (current_order >= pageblock_order) { 1160 change_pageblock_range(page, current_order, start_type); 1161 return start_type; 1162 } 1163 1164 if (current_order >= pageblock_order / 2 || 1165 start_type == MIGRATE_RECLAIMABLE || 1166 page_group_by_mobility_disabled) { 1167 int pages; 1168 1169 pages = move_freepages_block(zone, page, start_type); 1170 1171 /* Claim the whole block if over half of it is free */ 1172 if (pages >= (1 << (pageblock_order-1)) || 1173 page_group_by_mobility_disabled) { 1174 1175 set_pageblock_migratetype(page, start_type); 1176 return start_type; 1177 } 1178 1179 } 1180 1181 return fallback_type; 1182 } 1183 1184 /* Remove an element from the buddy allocator from the fallback list */ 1185 static inline struct page * 1186 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype) 1187 { 1188 struct free_area *area; 1189 unsigned int current_order; 1190 struct page *page; 1191 int migratetype, new_type, i; 1192 1193 /* Find the largest possible block of pages in the other list */ 1194 for (current_order = MAX_ORDER-1; 1195 current_order >= order && current_order <= MAX_ORDER-1; 1196 --current_order) { 1197 for (i = 0;; i++) { 1198 migratetype = fallbacks[start_migratetype][i]; 1199 1200 /* MIGRATE_RESERVE handled later if necessary */ 1201 if (migratetype == MIGRATE_RESERVE) 1202 break; 1203 1204 area = &(zone->free_area[current_order]); 1205 if (list_empty(&area->free_list[migratetype])) 1206 continue; 1207 1208 page = list_entry(area->free_list[migratetype].next, 1209 struct page, lru); 1210 area->nr_free--; 1211 1212 new_type = try_to_steal_freepages(zone, page, 1213 start_migratetype, 1214 migratetype); 1215 1216 /* Remove the page from the freelists */ 1217 list_del(&page->lru); 1218 rmv_page_order(page); 1219 1220 expand(zone, page, order, current_order, area, 1221 new_type); 1222 /* The freepage_migratetype may differ from pageblock's 1223 * migratetype depending on the decisions in 1224 * try_to_steal_freepages. This is OK as long as it does 1225 * not differ for MIGRATE_CMA type. 1226 */ 1227 set_freepage_migratetype(page, new_type); 1228 1229 trace_mm_page_alloc_extfrag(page, order, current_order, 1230 start_migratetype, migratetype, new_type); 1231 1232 return page; 1233 } 1234 } 1235 1236 return NULL; 1237 } 1238 1239 /* 1240 * Do the hard work of removing an element from the buddy allocator. 1241 * Call me with the zone->lock already held. 1242 */ 1243 static struct page *__rmqueue(struct zone *zone, unsigned int order, 1244 int migratetype) 1245 { 1246 struct page *page; 1247 1248 retry_reserve: 1249 page = __rmqueue_smallest(zone, order, migratetype); 1250 1251 if (unlikely(!page) && migratetype != MIGRATE_RESERVE) { 1252 page = __rmqueue_fallback(zone, order, migratetype); 1253 1254 /* 1255 * Use MIGRATE_RESERVE rather than fail an allocation. goto 1256 * is used because __rmqueue_smallest is an inline function 1257 * and we want just one call site 1258 */ 1259 if (!page) { 1260 migratetype = MIGRATE_RESERVE; 1261 goto retry_reserve; 1262 } 1263 } 1264 1265 trace_mm_page_alloc_zone_locked(page, order, migratetype); 1266 return page; 1267 } 1268 1269 /* 1270 * Obtain a specified number of elements from the buddy allocator, all under 1271 * a single hold of the lock, for efficiency. Add them to the supplied list. 1272 * Returns the number of new pages which were placed at *list. 1273 */ 1274 static int rmqueue_bulk(struct zone *zone, unsigned int order, 1275 unsigned long count, struct list_head *list, 1276 int migratetype, bool cold) 1277 { 1278 int i; 1279 1280 spin_lock(&zone->lock); 1281 for (i = 0; i < count; ++i) { 1282 struct page *page = __rmqueue(zone, order, migratetype); 1283 if (unlikely(page == NULL)) 1284 break; 1285 1286 /* 1287 * Split buddy pages returned by expand() are received here 1288 * in physical page order. The page is added to the callers and 1289 * list and the list head then moves forward. From the callers 1290 * perspective, the linked list is ordered by page number in 1291 * some conditions. This is useful for IO devices that can 1292 * merge IO requests if the physical pages are ordered 1293 * properly. 1294 */ 1295 if (likely(!cold)) 1296 list_add(&page->lru, list); 1297 else 1298 list_add_tail(&page->lru, list); 1299 list = &page->lru; 1300 if (is_migrate_cma(get_freepage_migratetype(page))) 1301 __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1302 -(1 << order)); 1303 } 1304 __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); 1305 spin_unlock(&zone->lock); 1306 return i; 1307 } 1308 1309 #ifdef CONFIG_NUMA 1310 /* 1311 * Called from the vmstat counter updater to drain pagesets of this 1312 * currently executing processor on remote nodes after they have 1313 * expired. 1314 * 1315 * Note that this function must be called with the thread pinned to 1316 * a single processor. 1317 */ 1318 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) 1319 { 1320 unsigned long flags; 1321 int to_drain, batch; 1322 1323 local_irq_save(flags); 1324 batch = ACCESS_ONCE(pcp->batch); 1325 to_drain = min(pcp->count, batch); 1326 if (to_drain > 0) { 1327 free_pcppages_bulk(zone, to_drain, pcp); 1328 pcp->count -= to_drain; 1329 } 1330 local_irq_restore(flags); 1331 } 1332 #endif 1333 1334 /* 1335 * Drain pcplists of the indicated processor and zone. 1336 * 1337 * The processor must either be the current processor and the 1338 * thread pinned to the current processor or a processor that 1339 * is not online. 1340 */ 1341 static void drain_pages_zone(unsigned int cpu, struct zone *zone) 1342 { 1343 unsigned long flags; 1344 struct per_cpu_pageset *pset; 1345 struct per_cpu_pages *pcp; 1346 1347 local_irq_save(flags); 1348 pset = per_cpu_ptr(zone->pageset, cpu); 1349 1350 pcp = &pset->pcp; 1351 if (pcp->count) { 1352 free_pcppages_bulk(zone, pcp->count, pcp); 1353 pcp->count = 0; 1354 } 1355 local_irq_restore(flags); 1356 } 1357 1358 /* 1359 * Drain pcplists of all zones on the indicated processor. 1360 * 1361 * The processor must either be the current processor and the 1362 * thread pinned to the current processor or a processor that 1363 * is not online. 1364 */ 1365 static void drain_pages(unsigned int cpu) 1366 { 1367 struct zone *zone; 1368 1369 for_each_populated_zone(zone) { 1370 drain_pages_zone(cpu, zone); 1371 } 1372 } 1373 1374 /* 1375 * Spill all of this CPU's per-cpu pages back into the buddy allocator. 1376 * 1377 * The CPU has to be pinned. When zone parameter is non-NULL, spill just 1378 * the single zone's pages. 1379 */ 1380 void drain_local_pages(struct zone *zone) 1381 { 1382 int cpu = smp_processor_id(); 1383 1384 if (zone) 1385 drain_pages_zone(cpu, zone); 1386 else 1387 drain_pages(cpu); 1388 } 1389 1390 /* 1391 * Spill all the per-cpu pages from all CPUs back into the buddy allocator. 1392 * 1393 * When zone parameter is non-NULL, spill just the single zone's pages. 1394 * 1395 * Note that this code is protected against sending an IPI to an offline 1396 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs: 1397 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but 1398 * nothing keeps CPUs from showing up after we populated the cpumask and 1399 * before the call to on_each_cpu_mask(). 1400 */ 1401 void drain_all_pages(struct zone *zone) 1402 { 1403 int cpu; 1404 1405 /* 1406 * Allocate in the BSS so we wont require allocation in 1407 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y 1408 */ 1409 static cpumask_t cpus_with_pcps; 1410 1411 /* 1412 * We don't care about racing with CPU hotplug event 1413 * as offline notification will cause the notified 1414 * cpu to drain that CPU pcps and on_each_cpu_mask 1415 * disables preemption as part of its processing 1416 */ 1417 for_each_online_cpu(cpu) { 1418 struct per_cpu_pageset *pcp; 1419 struct zone *z; 1420 bool has_pcps = false; 1421 1422 if (zone) { 1423 pcp = per_cpu_ptr(zone->pageset, cpu); 1424 if (pcp->pcp.count) 1425 has_pcps = true; 1426 } else { 1427 for_each_populated_zone(z) { 1428 pcp = per_cpu_ptr(z->pageset, cpu); 1429 if (pcp->pcp.count) { 1430 has_pcps = true; 1431 break; 1432 } 1433 } 1434 } 1435 1436 if (has_pcps) 1437 cpumask_set_cpu(cpu, &cpus_with_pcps); 1438 else 1439 cpumask_clear_cpu(cpu, &cpus_with_pcps); 1440 } 1441 on_each_cpu_mask(&cpus_with_pcps, (smp_call_func_t) drain_local_pages, 1442 zone, 1); 1443 } 1444 1445 #ifdef CONFIG_HIBERNATION 1446 1447 void mark_free_pages(struct zone *zone) 1448 { 1449 unsigned long pfn, max_zone_pfn; 1450 unsigned long flags; 1451 unsigned int order, t; 1452 struct list_head *curr; 1453 1454 if (zone_is_empty(zone)) 1455 return; 1456 1457 spin_lock_irqsave(&zone->lock, flags); 1458 1459 max_zone_pfn = zone_end_pfn(zone); 1460 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) 1461 if (pfn_valid(pfn)) { 1462 struct page *page = pfn_to_page(pfn); 1463 1464 if (!swsusp_page_is_forbidden(page)) 1465 swsusp_unset_page_free(page); 1466 } 1467 1468 for_each_migratetype_order(order, t) { 1469 list_for_each(curr, &zone->free_area[order].free_list[t]) { 1470 unsigned long i; 1471 1472 pfn = page_to_pfn(list_entry(curr, struct page, lru)); 1473 for (i = 0; i < (1UL << order); i++) 1474 swsusp_set_page_free(pfn_to_page(pfn + i)); 1475 } 1476 } 1477 spin_unlock_irqrestore(&zone->lock, flags); 1478 } 1479 #endif /* CONFIG_PM */ 1480 1481 /* 1482 * Free a 0-order page 1483 * cold == true ? free a cold page : free a hot page 1484 */ 1485 void free_hot_cold_page(struct page *page, bool cold) 1486 { 1487 struct zone *zone = page_zone(page); 1488 struct per_cpu_pages *pcp; 1489 unsigned long flags; 1490 unsigned long pfn = page_to_pfn(page); 1491 int migratetype; 1492 1493 if (!free_pages_prepare(page, 0)) 1494 return; 1495 1496 migratetype = get_pfnblock_migratetype(page, pfn); 1497 set_freepage_migratetype(page, migratetype); 1498 local_irq_save(flags); 1499 __count_vm_event(PGFREE); 1500 1501 /* 1502 * We only track unmovable, reclaimable and movable on pcp lists. 1503 * Free ISOLATE pages back to the allocator because they are being 1504 * offlined but treat RESERVE as movable pages so we can get those 1505 * areas back if necessary. Otherwise, we may have to free 1506 * excessively into the page allocator 1507 */ 1508 if (migratetype >= MIGRATE_PCPTYPES) { 1509 if (unlikely(is_migrate_isolate(migratetype))) { 1510 free_one_page(zone, page, pfn, 0, migratetype); 1511 goto out; 1512 } 1513 migratetype = MIGRATE_MOVABLE; 1514 } 1515 1516 pcp = &this_cpu_ptr(zone->pageset)->pcp; 1517 if (!cold) 1518 list_add(&page->lru, &pcp->lists[migratetype]); 1519 else 1520 list_add_tail(&page->lru, &pcp->lists[migratetype]); 1521 pcp->count++; 1522 if (pcp->count >= pcp->high) { 1523 unsigned long batch = ACCESS_ONCE(pcp->batch); 1524 free_pcppages_bulk(zone, batch, pcp); 1525 pcp->count -= batch; 1526 } 1527 1528 out: 1529 local_irq_restore(flags); 1530 } 1531 1532 /* 1533 * Free a list of 0-order pages 1534 */ 1535 void free_hot_cold_page_list(struct list_head *list, bool cold) 1536 { 1537 struct page *page, *next; 1538 1539 list_for_each_entry_safe(page, next, list, lru) { 1540 trace_mm_page_free_batched(page, cold); 1541 free_hot_cold_page(page, cold); 1542 } 1543 } 1544 1545 /* 1546 * split_page takes a non-compound higher-order page, and splits it into 1547 * n (1<<order) sub-pages: page[0..n] 1548 * Each sub-page must be freed individually. 1549 * 1550 * Note: this is probably too low level an operation for use in drivers. 1551 * Please consult with lkml before using this in your driver. 1552 */ 1553 void split_page(struct page *page, unsigned int order) 1554 { 1555 int i; 1556 1557 VM_BUG_ON_PAGE(PageCompound(page), page); 1558 VM_BUG_ON_PAGE(!page_count(page), page); 1559 1560 #ifdef CONFIG_KMEMCHECK 1561 /* 1562 * Split shadow pages too, because free(page[0]) would 1563 * otherwise free the whole shadow. 1564 */ 1565 if (kmemcheck_page_is_tracked(page)) 1566 split_page(virt_to_page(page[0].shadow), order); 1567 #endif 1568 1569 set_page_owner(page, 0, 0); 1570 for (i = 1; i < (1 << order); i++) { 1571 set_page_refcounted(page + i); 1572 set_page_owner(page + i, 0, 0); 1573 } 1574 } 1575 EXPORT_SYMBOL_GPL(split_page); 1576 1577 int __isolate_free_page(struct page *page, unsigned int order) 1578 { 1579 unsigned long watermark; 1580 struct zone *zone; 1581 int mt; 1582 1583 BUG_ON(!PageBuddy(page)); 1584 1585 zone = page_zone(page); 1586 mt = get_pageblock_migratetype(page); 1587 1588 if (!is_migrate_isolate(mt)) { 1589 /* Obey watermarks as if the page was being allocated */ 1590 watermark = low_wmark_pages(zone) + (1 << order); 1591 if (!zone_watermark_ok(zone, 0, watermark, 0, 0)) 1592 return 0; 1593 1594 __mod_zone_freepage_state(zone, -(1UL << order), mt); 1595 } 1596 1597 /* Remove page from free list */ 1598 list_del(&page->lru); 1599 zone->free_area[order].nr_free--; 1600 rmv_page_order(page); 1601 1602 /* Set the pageblock if the isolated page is at least a pageblock */ 1603 if (order >= pageblock_order - 1) { 1604 struct page *endpage = page + (1 << order) - 1; 1605 for (; page < endpage; page += pageblock_nr_pages) { 1606 int mt = get_pageblock_migratetype(page); 1607 if (!is_migrate_isolate(mt) && !is_migrate_cma(mt)) 1608 set_pageblock_migratetype(page, 1609 MIGRATE_MOVABLE); 1610 } 1611 } 1612 1613 set_page_owner(page, order, 0); 1614 return 1UL << order; 1615 } 1616 1617 /* 1618 * Similar to split_page except the page is already free. As this is only 1619 * being used for migration, the migratetype of the block also changes. 1620 * As this is called with interrupts disabled, the caller is responsible 1621 * for calling arch_alloc_page() and kernel_map_page() after interrupts 1622 * are enabled. 1623 * 1624 * Note: this is probably too low level an operation for use in drivers. 1625 * Please consult with lkml before using this in your driver. 1626 */ 1627 int split_free_page(struct page *page) 1628 { 1629 unsigned int order; 1630 int nr_pages; 1631 1632 order = page_order(page); 1633 1634 nr_pages = __isolate_free_page(page, order); 1635 if (!nr_pages) 1636 return 0; 1637 1638 /* Split into individual pages */ 1639 set_page_refcounted(page); 1640 split_page(page, order); 1641 return nr_pages; 1642 } 1643 1644 /* 1645 * Really, prep_compound_page() should be called from __rmqueue_bulk(). But 1646 * we cheat by calling it from here, in the order > 0 path. Saves a branch 1647 * or two. 1648 */ 1649 static inline 1650 struct page *buffered_rmqueue(struct zone *preferred_zone, 1651 struct zone *zone, unsigned int order, 1652 gfp_t gfp_flags, int migratetype) 1653 { 1654 unsigned long flags; 1655 struct page *page; 1656 bool cold = ((gfp_flags & __GFP_COLD) != 0); 1657 1658 again: 1659 if (likely(order == 0)) { 1660 struct per_cpu_pages *pcp; 1661 struct list_head *list; 1662 1663 local_irq_save(flags); 1664 pcp = &this_cpu_ptr(zone->pageset)->pcp; 1665 list = &pcp->lists[migratetype]; 1666 if (list_empty(list)) { 1667 pcp->count += rmqueue_bulk(zone, 0, 1668 pcp->batch, list, 1669 migratetype, cold); 1670 if (unlikely(list_empty(list))) 1671 goto failed; 1672 } 1673 1674 if (cold) 1675 page = list_entry(list->prev, struct page, lru); 1676 else 1677 page = list_entry(list->next, struct page, lru); 1678 1679 list_del(&page->lru); 1680 pcp->count--; 1681 } else { 1682 if (unlikely(gfp_flags & __GFP_NOFAIL)) { 1683 /* 1684 * __GFP_NOFAIL is not to be used in new code. 1685 * 1686 * All __GFP_NOFAIL callers should be fixed so that they 1687 * properly detect and handle allocation failures. 1688 * 1689 * We most definitely don't want callers attempting to 1690 * allocate greater than order-1 page units with 1691 * __GFP_NOFAIL. 1692 */ 1693 WARN_ON_ONCE(order > 1); 1694 } 1695 spin_lock_irqsave(&zone->lock, flags); 1696 page = __rmqueue(zone, order, migratetype); 1697 spin_unlock(&zone->lock); 1698 if (!page) 1699 goto failed; 1700 __mod_zone_freepage_state(zone, -(1 << order), 1701 get_freepage_migratetype(page)); 1702 } 1703 1704 __mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order)); 1705 if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 && 1706 !test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) 1707 set_bit(ZONE_FAIR_DEPLETED, &zone->flags); 1708 1709 __count_zone_vm_events(PGALLOC, zone, 1 << order); 1710 zone_statistics(preferred_zone, zone, gfp_flags); 1711 local_irq_restore(flags); 1712 1713 VM_BUG_ON_PAGE(bad_range(zone, page), page); 1714 if (prep_new_page(page, order, gfp_flags)) 1715 goto again; 1716 return page; 1717 1718 failed: 1719 local_irq_restore(flags); 1720 return NULL; 1721 } 1722 1723 #ifdef CONFIG_FAIL_PAGE_ALLOC 1724 1725 static struct { 1726 struct fault_attr attr; 1727 1728 u32 ignore_gfp_highmem; 1729 u32 ignore_gfp_wait; 1730 u32 min_order; 1731 } fail_page_alloc = { 1732 .attr = FAULT_ATTR_INITIALIZER, 1733 .ignore_gfp_wait = 1, 1734 .ignore_gfp_highmem = 1, 1735 .min_order = 1, 1736 }; 1737 1738 static int __init setup_fail_page_alloc(char *str) 1739 { 1740 return setup_fault_attr(&fail_page_alloc.attr, str); 1741 } 1742 __setup("fail_page_alloc=", setup_fail_page_alloc); 1743 1744 static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1745 { 1746 if (order < fail_page_alloc.min_order) 1747 return false; 1748 if (gfp_mask & __GFP_NOFAIL) 1749 return false; 1750 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 1751 return false; 1752 if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) 1753 return false; 1754 1755 return should_fail(&fail_page_alloc.attr, 1 << order); 1756 } 1757 1758 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 1759 1760 static int __init fail_page_alloc_debugfs(void) 1761 { 1762 umode_t mode = S_IFREG | S_IRUSR | S_IWUSR; 1763 struct dentry *dir; 1764 1765 dir = fault_create_debugfs_attr("fail_page_alloc", NULL, 1766 &fail_page_alloc.attr); 1767 if (IS_ERR(dir)) 1768 return PTR_ERR(dir); 1769 1770 if (!debugfs_create_bool("ignore-gfp-wait", mode, dir, 1771 &fail_page_alloc.ignore_gfp_wait)) 1772 goto fail; 1773 if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir, 1774 &fail_page_alloc.ignore_gfp_highmem)) 1775 goto fail; 1776 if (!debugfs_create_u32("min-order", mode, dir, 1777 &fail_page_alloc.min_order)) 1778 goto fail; 1779 1780 return 0; 1781 fail: 1782 debugfs_remove_recursive(dir); 1783 1784 return -ENOMEM; 1785 } 1786 1787 late_initcall(fail_page_alloc_debugfs); 1788 1789 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 1790 1791 #else /* CONFIG_FAIL_PAGE_ALLOC */ 1792 1793 static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 1794 { 1795 return false; 1796 } 1797 1798 #endif /* CONFIG_FAIL_PAGE_ALLOC */ 1799 1800 /* 1801 * Return true if free pages are above 'mark'. This takes into account the order 1802 * of the allocation. 1803 */ 1804 static bool __zone_watermark_ok(struct zone *z, unsigned int order, 1805 unsigned long mark, int classzone_idx, int alloc_flags, 1806 long free_pages) 1807 { 1808 /* free_pages may go negative - that's OK */ 1809 long min = mark; 1810 int o; 1811 long free_cma = 0; 1812 1813 free_pages -= (1 << order) - 1; 1814 if (alloc_flags & ALLOC_HIGH) 1815 min -= min / 2; 1816 if (alloc_flags & ALLOC_HARDER) 1817 min -= min / 4; 1818 #ifdef CONFIG_CMA 1819 /* If allocation can't use CMA areas don't use free CMA pages */ 1820 if (!(alloc_flags & ALLOC_CMA)) 1821 free_cma = zone_page_state(z, NR_FREE_CMA_PAGES); 1822 #endif 1823 1824 if (free_pages - free_cma <= min + z->lowmem_reserve[classzone_idx]) 1825 return false; 1826 for (o = 0; o < order; o++) { 1827 /* At the next order, this order's pages become unavailable */ 1828 free_pages -= z->free_area[o].nr_free << o; 1829 1830 /* Require fewer higher order pages to be free */ 1831 min >>= 1; 1832 1833 if (free_pages <= min) 1834 return false; 1835 } 1836 return true; 1837 } 1838 1839 bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, 1840 int classzone_idx, int alloc_flags) 1841 { 1842 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, 1843 zone_page_state(z, NR_FREE_PAGES)); 1844 } 1845 1846 bool zone_watermark_ok_safe(struct zone *z, unsigned int order, 1847 unsigned long mark, int classzone_idx, int alloc_flags) 1848 { 1849 long free_pages = zone_page_state(z, NR_FREE_PAGES); 1850 1851 if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark) 1852 free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES); 1853 1854 return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, 1855 free_pages); 1856 } 1857 1858 #ifdef CONFIG_NUMA 1859 /* 1860 * zlc_setup - Setup for "zonelist cache". Uses cached zone data to 1861 * skip over zones that are not allowed by the cpuset, or that have 1862 * been recently (in last second) found to be nearly full. See further 1863 * comments in mmzone.h. Reduces cache footprint of zonelist scans 1864 * that have to skip over a lot of full or unallowed zones. 1865 * 1866 * If the zonelist cache is present in the passed zonelist, then 1867 * returns a pointer to the allowed node mask (either the current 1868 * tasks mems_allowed, or node_states[N_MEMORY].) 1869 * 1870 * If the zonelist cache is not available for this zonelist, does 1871 * nothing and returns NULL. 1872 * 1873 * If the fullzones BITMAP in the zonelist cache is stale (more than 1874 * a second since last zap'd) then we zap it out (clear its bits.) 1875 * 1876 * We hold off even calling zlc_setup, until after we've checked the 1877 * first zone in the zonelist, on the theory that most allocations will 1878 * be satisfied from that first zone, so best to examine that zone as 1879 * quickly as we can. 1880 */ 1881 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1882 { 1883 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1884 nodemask_t *allowednodes; /* zonelist_cache approximation */ 1885 1886 zlc = zonelist->zlcache_ptr; 1887 if (!zlc) 1888 return NULL; 1889 1890 if (time_after(jiffies, zlc->last_full_zap + HZ)) { 1891 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1892 zlc->last_full_zap = jiffies; 1893 } 1894 1895 allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? 1896 &cpuset_current_mems_allowed : 1897 &node_states[N_MEMORY]; 1898 return allowednodes; 1899 } 1900 1901 /* 1902 * Given 'z' scanning a zonelist, run a couple of quick checks to see 1903 * if it is worth looking at further for free memory: 1904 * 1) Check that the zone isn't thought to be full (doesn't have its 1905 * bit set in the zonelist_cache fullzones BITMAP). 1906 * 2) Check that the zones node (obtained from the zonelist_cache 1907 * z_to_n[] mapping) is allowed in the passed in allowednodes mask. 1908 * Return true (non-zero) if zone is worth looking at further, or 1909 * else return false (zero) if it is not. 1910 * 1911 * This check -ignores- the distinction between various watermarks, 1912 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is 1913 * found to be full for any variation of these watermarks, it will 1914 * be considered full for up to one second by all requests, unless 1915 * we are so low on memory on all allowed nodes that we are forced 1916 * into the second scan of the zonelist. 1917 * 1918 * In the second scan we ignore this zonelist cache and exactly 1919 * apply the watermarks to all zones, even it is slower to do so. 1920 * We are low on memory in the second scan, and should leave no stone 1921 * unturned looking for a free page. 1922 */ 1923 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1924 nodemask_t *allowednodes) 1925 { 1926 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1927 int i; /* index of *z in zonelist zones */ 1928 int n; /* node that zone *z is on */ 1929 1930 zlc = zonelist->zlcache_ptr; 1931 if (!zlc) 1932 return 1; 1933 1934 i = z - zonelist->_zonerefs; 1935 n = zlc->z_to_n[i]; 1936 1937 /* This zone is worth trying if it is allowed but not full */ 1938 return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); 1939 } 1940 1941 /* 1942 * Given 'z' scanning a zonelist, set the corresponding bit in 1943 * zlc->fullzones, so that subsequent attempts to allocate a page 1944 * from that zone don't waste time re-examining it. 1945 */ 1946 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 1947 { 1948 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1949 int i; /* index of *z in zonelist zones */ 1950 1951 zlc = zonelist->zlcache_ptr; 1952 if (!zlc) 1953 return; 1954 1955 i = z - zonelist->_zonerefs; 1956 1957 set_bit(i, zlc->fullzones); 1958 } 1959 1960 /* 1961 * clear all zones full, called after direct reclaim makes progress so that 1962 * a zone that was recently full is not skipped over for up to a second 1963 */ 1964 static void zlc_clear_zones_full(struct zonelist *zonelist) 1965 { 1966 struct zonelist_cache *zlc; /* cached zonelist speedup info */ 1967 1968 zlc = zonelist->zlcache_ptr; 1969 if (!zlc) 1970 return; 1971 1972 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 1973 } 1974 1975 static bool zone_local(struct zone *local_zone, struct zone *zone) 1976 { 1977 return local_zone->node == zone->node; 1978 } 1979 1980 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) 1981 { 1982 return node_distance(zone_to_nid(local_zone), zone_to_nid(zone)) < 1983 RECLAIM_DISTANCE; 1984 } 1985 1986 #else /* CONFIG_NUMA */ 1987 1988 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) 1989 { 1990 return NULL; 1991 } 1992 1993 static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, 1994 nodemask_t *allowednodes) 1995 { 1996 return 1; 1997 } 1998 1999 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) 2000 { 2001 } 2002 2003 static void zlc_clear_zones_full(struct zonelist *zonelist) 2004 { 2005 } 2006 2007 static bool zone_local(struct zone *local_zone, struct zone *zone) 2008 { 2009 return true; 2010 } 2011 2012 static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) 2013 { 2014 return true; 2015 } 2016 2017 #endif /* CONFIG_NUMA */ 2018 2019 static void reset_alloc_batches(struct zone *preferred_zone) 2020 { 2021 struct zone *zone = preferred_zone->zone_pgdat->node_zones; 2022 2023 do { 2024 mod_zone_page_state(zone, NR_ALLOC_BATCH, 2025 high_wmark_pages(zone) - low_wmark_pages(zone) - 2026 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH])); 2027 clear_bit(ZONE_FAIR_DEPLETED, &zone->flags); 2028 } while (zone++ != preferred_zone); 2029 } 2030 2031 /* 2032 * get_page_from_freelist goes through the zonelist trying to allocate 2033 * a page. 2034 */ 2035 static struct page * 2036 get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order, 2037 struct zonelist *zonelist, int high_zoneidx, int alloc_flags, 2038 struct zone *preferred_zone, int classzone_idx, int migratetype) 2039 { 2040 struct zoneref *z; 2041 struct page *page = NULL; 2042 struct zone *zone; 2043 nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ 2044 int zlc_active = 0; /* set if using zonelist_cache */ 2045 int did_zlc_setup = 0; /* just call zlc_setup() one time */ 2046 bool consider_zone_dirty = (alloc_flags & ALLOC_WMARK_LOW) && 2047 (gfp_mask & __GFP_WRITE); 2048 int nr_fair_skipped = 0; 2049 bool zonelist_rescan; 2050 2051 zonelist_scan: 2052 zonelist_rescan = false; 2053 2054 /* 2055 * Scan zonelist, looking for a zone with enough free. 2056 * See also __cpuset_node_allowed() comment in kernel/cpuset.c. 2057 */ 2058 for_each_zone_zonelist_nodemask(zone, z, zonelist, 2059 high_zoneidx, nodemask) { 2060 unsigned long mark; 2061 2062 if (IS_ENABLED(CONFIG_NUMA) && zlc_active && 2063 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 2064 continue; 2065 if (cpusets_enabled() && 2066 (alloc_flags & ALLOC_CPUSET) && 2067 !cpuset_zone_allowed(zone, gfp_mask)) 2068 continue; 2069 /* 2070 * Distribute pages in proportion to the individual 2071 * zone size to ensure fair page aging. The zone a 2072 * page was allocated in should have no effect on the 2073 * time the page has in memory before being reclaimed. 2074 */ 2075 if (alloc_flags & ALLOC_FAIR) { 2076 if (!zone_local(preferred_zone, zone)) 2077 break; 2078 if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) { 2079 nr_fair_skipped++; 2080 continue; 2081 } 2082 } 2083 /* 2084 * When allocating a page cache page for writing, we 2085 * want to get it from a zone that is within its dirty 2086 * limit, such that no single zone holds more than its 2087 * proportional share of globally allowed dirty pages. 2088 * The dirty limits take into account the zone's 2089 * lowmem reserves and high watermark so that kswapd 2090 * should be able to balance it without having to 2091 * write pages from its LRU list. 2092 * 2093 * This may look like it could increase pressure on 2094 * lower zones by failing allocations in higher zones 2095 * before they are full. But the pages that do spill 2096 * over are limited as the lower zones are protected 2097 * by this very same mechanism. It should not become 2098 * a practical burden to them. 2099 * 2100 * XXX: For now, allow allocations to potentially 2101 * exceed the per-zone dirty limit in the slowpath 2102 * (ALLOC_WMARK_LOW unset) before going into reclaim, 2103 * which is important when on a NUMA setup the allowed 2104 * zones are together not big enough to reach the 2105 * global limit. The proper fix for these situations 2106 * will require awareness of zones in the 2107 * dirty-throttling and the flusher threads. 2108 */ 2109 if (consider_zone_dirty && !zone_dirty_ok(zone)) 2110 continue; 2111 2112 mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK]; 2113 if (!zone_watermark_ok(zone, order, mark, 2114 classzone_idx, alloc_flags)) { 2115 int ret; 2116 2117 /* Checked here to keep the fast path fast */ 2118 BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK); 2119 if (alloc_flags & ALLOC_NO_WATERMARKS) 2120 goto try_this_zone; 2121 2122 if (IS_ENABLED(CONFIG_NUMA) && 2123 !did_zlc_setup && nr_online_nodes > 1) { 2124 /* 2125 * we do zlc_setup if there are multiple nodes 2126 * and before considering the first zone allowed 2127 * by the cpuset. 2128 */ 2129 allowednodes = zlc_setup(zonelist, alloc_flags); 2130 zlc_active = 1; 2131 did_zlc_setup = 1; 2132 } 2133 2134 if (zone_reclaim_mode == 0 || 2135 !zone_allows_reclaim(preferred_zone, zone)) 2136 goto this_zone_full; 2137 2138 /* 2139 * As we may have just activated ZLC, check if the first 2140 * eligible zone has failed zone_reclaim recently. 2141 */ 2142 if (IS_ENABLED(CONFIG_NUMA) && zlc_active && 2143 !zlc_zone_worth_trying(zonelist, z, allowednodes)) 2144 continue; 2145 2146 ret = zone_reclaim(zone, gfp_mask, order); 2147 switch (ret) { 2148 case ZONE_RECLAIM_NOSCAN: 2149 /* did not scan */ 2150 continue; 2151 case ZONE_RECLAIM_FULL: 2152 /* scanned but unreclaimable */ 2153 continue; 2154 default: 2155 /* did we reclaim enough */ 2156 if (zone_watermark_ok(zone, order, mark, 2157 classzone_idx, alloc_flags)) 2158 goto try_this_zone; 2159 2160 /* 2161 * Failed to reclaim enough to meet watermark. 2162 * Only mark the zone full if checking the min 2163 * watermark or if we failed to reclaim just 2164 * 1<<order pages or else the page allocator 2165 * fastpath will prematurely mark zones full 2166 * when the watermark is between the low and 2167 * min watermarks. 2168 */ 2169 if (((alloc_flags & ALLOC_WMARK_MASK) == ALLOC_WMARK_MIN) || 2170 ret == ZONE_RECLAIM_SOME) 2171 goto this_zone_full; 2172 2173 continue; 2174 } 2175 } 2176 2177 try_this_zone: 2178 page = buffered_rmqueue(preferred_zone, zone, order, 2179 gfp_mask, migratetype); 2180 if (page) 2181 break; 2182 this_zone_full: 2183 if (IS_ENABLED(CONFIG_NUMA) && zlc_active) 2184 zlc_mark_zone_full(zonelist, z); 2185 } 2186 2187 if (page) { 2188 /* 2189 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was 2190 * necessary to allocate the page. The expectation is 2191 * that the caller is taking steps that will free more 2192 * memory. The caller should avoid the page being used 2193 * for !PFMEMALLOC purposes. 2194 */ 2195 page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS); 2196 return page; 2197 } 2198 2199 /* 2200 * The first pass makes sure allocations are spread fairly within the 2201 * local node. However, the local node might have free pages left 2202 * after the fairness batches are exhausted, and remote zones haven't 2203 * even been considered yet. Try once more without fairness, and 2204 * include remote zones now, before entering the slowpath and waking 2205 * kswapd: prefer spilling to a remote zone over swapping locally. 2206 */ 2207 if (alloc_flags & ALLOC_FAIR) { 2208 alloc_flags &= ~ALLOC_FAIR; 2209 if (nr_fair_skipped) { 2210 zonelist_rescan = true; 2211 reset_alloc_batches(preferred_zone); 2212 } 2213 if (nr_online_nodes > 1) 2214 zonelist_rescan = true; 2215 } 2216 2217 if (unlikely(IS_ENABLED(CONFIG_NUMA) && zlc_active)) { 2218 /* Disable zlc cache for second zonelist scan */ 2219 zlc_active = 0; 2220 zonelist_rescan = true; 2221 } 2222 2223 if (zonelist_rescan) 2224 goto zonelist_scan; 2225 2226 return NULL; 2227 } 2228 2229 /* 2230 * Large machines with many possible nodes should not always dump per-node 2231 * meminfo in irq context. 2232 */ 2233 static inline bool should_suppress_show_mem(void) 2234 { 2235 bool ret = false; 2236 2237 #if NODES_SHIFT > 8 2238 ret = in_interrupt(); 2239 #endif 2240 return ret; 2241 } 2242 2243 static DEFINE_RATELIMIT_STATE(nopage_rs, 2244 DEFAULT_RATELIMIT_INTERVAL, 2245 DEFAULT_RATELIMIT_BURST); 2246 2247 void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...) 2248 { 2249 unsigned int filter = SHOW_MEM_FILTER_NODES; 2250 2251 if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) || 2252 debug_guardpage_minorder() > 0) 2253 return; 2254 2255 /* 2256 * This documents exceptions given to allocations in certain 2257 * contexts that are allowed to allocate outside current's set 2258 * of allowed nodes. 2259 */ 2260 if (!(gfp_mask & __GFP_NOMEMALLOC)) 2261 if (test_thread_flag(TIF_MEMDIE) || 2262 (current->flags & (PF_MEMALLOC | PF_EXITING))) 2263 filter &= ~SHOW_MEM_FILTER_NODES; 2264 if (in_interrupt() || !(gfp_mask & __GFP_WAIT)) 2265 filter &= ~SHOW_MEM_FILTER_NODES; 2266 2267 if (fmt) { 2268 struct va_format vaf; 2269 va_list args; 2270 2271 va_start(args, fmt); 2272 2273 vaf.fmt = fmt; 2274 vaf.va = &args; 2275 2276 pr_warn("%pV", &vaf); 2277 2278 va_end(args); 2279 } 2280 2281 pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n", 2282 current->comm, order, gfp_mask); 2283 2284 dump_stack(); 2285 if (!should_suppress_show_mem()) 2286 show_mem(filter); 2287 } 2288 2289 static inline int 2290 should_alloc_retry(gfp_t gfp_mask, unsigned int order, 2291 unsigned long did_some_progress, 2292 unsigned long pages_reclaimed) 2293 { 2294 /* Do not loop if specifically requested */ 2295 if (gfp_mask & __GFP_NORETRY) 2296 return 0; 2297 2298 /* Always retry if specifically requested */ 2299 if (gfp_mask & __GFP_NOFAIL) 2300 return 1; 2301 2302 /* 2303 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim 2304 * making forward progress without invoking OOM. Suspend also disables 2305 * storage devices so kswapd will not help. Bail if we are suspending. 2306 */ 2307 if (!did_some_progress && pm_suspended_storage()) 2308 return 0; 2309 2310 /* 2311 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER 2312 * means __GFP_NOFAIL, but that may not be true in other 2313 * implementations. 2314 */ 2315 if (order <= PAGE_ALLOC_COSTLY_ORDER) 2316 return 1; 2317 2318 /* 2319 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is 2320 * specified, then we retry until we no longer reclaim any pages 2321 * (above), or we've reclaimed an order of pages at least as 2322 * large as the allocation's order. In both cases, if the 2323 * allocation still fails, we stop retrying. 2324 */ 2325 if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order)) 2326 return 1; 2327 2328 return 0; 2329 } 2330 2331 static inline struct page * 2332 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, 2333 struct zonelist *zonelist, enum zone_type high_zoneidx, 2334 nodemask_t *nodemask, struct zone *preferred_zone, 2335 int classzone_idx, int migratetype, unsigned long *did_some_progress) 2336 { 2337 struct page *page; 2338 2339 *did_some_progress = 0; 2340 2341 if (oom_killer_disabled) 2342 return NULL; 2343 2344 /* 2345 * Acquire the per-zone oom lock for each zone. If that 2346 * fails, somebody else is making progress for us. 2347 */ 2348 if (!oom_zonelist_trylock(zonelist, gfp_mask)) { 2349 *did_some_progress = 1; 2350 schedule_timeout_uninterruptible(1); 2351 return NULL; 2352 } 2353 2354 /* 2355 * PM-freezer should be notified that there might be an OOM killer on 2356 * its way to kill and wake somebody up. This is too early and we might 2357 * end up not killing anything but false positives are acceptable. 2358 * See freeze_processes. 2359 */ 2360 note_oom_kill(); 2361 2362 /* 2363 * Go through the zonelist yet one more time, keep very high watermark 2364 * here, this is only to catch a parallel oom killing, we must fail if 2365 * we're still under heavy pressure. 2366 */ 2367 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, 2368 order, zonelist, high_zoneidx, 2369 ALLOC_WMARK_HIGH|ALLOC_CPUSET, 2370 preferred_zone, classzone_idx, migratetype); 2371 if (page) 2372 goto out; 2373 2374 if (!(gfp_mask & __GFP_NOFAIL)) { 2375 /* Coredumps can quickly deplete all memory reserves */ 2376 if (current->flags & PF_DUMPCORE) 2377 goto out; 2378 /* The OOM killer will not help higher order allocs */ 2379 if (order > PAGE_ALLOC_COSTLY_ORDER) 2380 goto out; 2381 /* The OOM killer does not needlessly kill tasks for lowmem */ 2382 if (high_zoneidx < ZONE_NORMAL) 2383 goto out; 2384 /* The OOM killer does not compensate for light reclaim */ 2385 if (!(gfp_mask & __GFP_FS)) 2386 goto out; 2387 /* 2388 * GFP_THISNODE contains __GFP_NORETRY and we never hit this. 2389 * Sanity check for bare calls of __GFP_THISNODE, not real OOM. 2390 * The caller should handle page allocation failure by itself if 2391 * it specifies __GFP_THISNODE. 2392 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER. 2393 */ 2394 if (gfp_mask & __GFP_THISNODE) 2395 goto out; 2396 } 2397 /* Exhausted what can be done so it's blamo time */ 2398 out_of_memory(zonelist, gfp_mask, order, nodemask, false); 2399 *did_some_progress = 1; 2400 out: 2401 oom_zonelist_unlock(zonelist, gfp_mask); 2402 return page; 2403 } 2404 2405 #ifdef CONFIG_COMPACTION 2406 /* Try memory compaction for high-order allocations before reclaim */ 2407 static struct page * 2408 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, 2409 struct zonelist *zonelist, enum zone_type high_zoneidx, 2410 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, 2411 int classzone_idx, int migratetype, enum migrate_mode mode, 2412 int *contended_compaction, bool *deferred_compaction) 2413 { 2414 unsigned long compact_result; 2415 struct page *page; 2416 2417 if (!order) 2418 return NULL; 2419 2420 current->flags |= PF_MEMALLOC; 2421 compact_result = try_to_compact_pages(zonelist, order, gfp_mask, 2422 nodemask, mode, 2423 contended_compaction, 2424 alloc_flags, classzone_idx); 2425 current->flags &= ~PF_MEMALLOC; 2426 2427 switch (compact_result) { 2428 case COMPACT_DEFERRED: 2429 *deferred_compaction = true; 2430 /* fall-through */ 2431 case COMPACT_SKIPPED: 2432 return NULL; 2433 default: 2434 break; 2435 } 2436 2437 /* 2438 * At least in one zone compaction wasn't deferred or skipped, so let's 2439 * count a compaction stall 2440 */ 2441 count_vm_event(COMPACTSTALL); 2442 2443 page = get_page_from_freelist(gfp_mask, nodemask, 2444 order, zonelist, high_zoneidx, 2445 alloc_flags & ~ALLOC_NO_WATERMARKS, 2446 preferred_zone, classzone_idx, migratetype); 2447 2448 if (page) { 2449 struct zone *zone = page_zone(page); 2450 2451 zone->compact_blockskip_flush = false; 2452 compaction_defer_reset(zone, order, true); 2453 count_vm_event(COMPACTSUCCESS); 2454 return page; 2455 } 2456 2457 /* 2458 * It's bad if compaction run occurs and fails. The most likely reason 2459 * is that pages exist, but not enough to satisfy watermarks. 2460 */ 2461 count_vm_event(COMPACTFAIL); 2462 2463 cond_resched(); 2464 2465 return NULL; 2466 } 2467 #else 2468 static inline struct page * 2469 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, 2470 struct zonelist *zonelist, enum zone_type high_zoneidx, 2471 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, 2472 int classzone_idx, int migratetype, enum migrate_mode mode, 2473 int *contended_compaction, bool *deferred_compaction) 2474 { 2475 return NULL; 2476 } 2477 #endif /* CONFIG_COMPACTION */ 2478 2479 /* Perform direct synchronous page reclaim */ 2480 static int 2481 __perform_reclaim(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist, 2482 nodemask_t *nodemask) 2483 { 2484 struct reclaim_state reclaim_state; 2485 int progress; 2486 2487 cond_resched(); 2488 2489 /* We now go into synchronous reclaim */ 2490 cpuset_memory_pressure_bump(); 2491 current->flags |= PF_MEMALLOC; 2492 lockdep_set_current_reclaim_state(gfp_mask); 2493 reclaim_state.reclaimed_slab = 0; 2494 current->reclaim_state = &reclaim_state; 2495 2496 progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask); 2497 2498 current->reclaim_state = NULL; 2499 lockdep_clear_current_reclaim_state(); 2500 current->flags &= ~PF_MEMALLOC; 2501 2502 cond_resched(); 2503 2504 return progress; 2505 } 2506 2507 /* The really slow allocator path where we enter direct reclaim */ 2508 static inline struct page * 2509 __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order, 2510 struct zonelist *zonelist, enum zone_type high_zoneidx, 2511 nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone, 2512 int classzone_idx, int migratetype, unsigned long *did_some_progress) 2513 { 2514 struct page *page = NULL; 2515 bool drained = false; 2516 2517 *did_some_progress = __perform_reclaim(gfp_mask, order, zonelist, 2518 nodemask); 2519 if (unlikely(!(*did_some_progress))) 2520 return NULL; 2521 2522 /* After successful reclaim, reconsider all zones for allocation */ 2523 if (IS_ENABLED(CONFIG_NUMA)) 2524 zlc_clear_zones_full(zonelist); 2525 2526 retry: 2527 page = get_page_from_freelist(gfp_mask, nodemask, order, 2528 zonelist, high_zoneidx, 2529 alloc_flags & ~ALLOC_NO_WATERMARKS, 2530 preferred_zone, classzone_idx, 2531 migratetype); 2532 2533 /* 2534 * If an allocation failed after direct reclaim, it could be because 2535 * pages are pinned on the per-cpu lists. Drain them and try again 2536 */ 2537 if (!page && !drained) { 2538 drain_all_pages(NULL); 2539 drained = true; 2540 goto retry; 2541 } 2542 2543 return page; 2544 } 2545 2546 /* 2547 * This is called in the allocator slow-path if the allocation request is of 2548 * sufficient urgency to ignore watermarks and take other desperate measures 2549 */ 2550 static inline struct page * 2551 __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order, 2552 struct zonelist *zonelist, enum zone_type high_zoneidx, 2553 nodemask_t *nodemask, struct zone *preferred_zone, 2554 int classzone_idx, int migratetype) 2555 { 2556 struct page *page; 2557 2558 do { 2559 page = get_page_from_freelist(gfp_mask, nodemask, order, 2560 zonelist, high_zoneidx, ALLOC_NO_WATERMARKS, 2561 preferred_zone, classzone_idx, migratetype); 2562 2563 if (!page && gfp_mask & __GFP_NOFAIL) 2564 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50); 2565 } while (!page && (gfp_mask & __GFP_NOFAIL)); 2566 2567 return page; 2568 } 2569 2570 static void wake_all_kswapds(unsigned int order, 2571 struct zonelist *zonelist, 2572 enum zone_type high_zoneidx, 2573 struct zone *preferred_zone, 2574 nodemask_t *nodemask) 2575 { 2576 struct zoneref *z; 2577 struct zone *zone; 2578 2579 for_each_zone_zonelist_nodemask(zone, z, zonelist, 2580 high_zoneidx, nodemask) 2581 wakeup_kswapd(zone, order, zone_idx(preferred_zone)); 2582 } 2583 2584 static inline int 2585 gfp_to_alloc_flags(gfp_t gfp_mask) 2586 { 2587 int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; 2588 const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD)); 2589 2590 /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */ 2591 BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH); 2592 2593 /* 2594 * The caller may dip into page reserves a bit more if the caller 2595 * cannot run direct reclaim, or if the caller has realtime scheduling 2596 * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will 2597 * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH). 2598 */ 2599 alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH); 2600 2601 if (atomic) { 2602 /* 2603 * Not worth trying to allocate harder for __GFP_NOMEMALLOC even 2604 * if it can't schedule. 2605 */ 2606 if (!(gfp_mask & __GFP_NOMEMALLOC)) 2607 alloc_flags |= ALLOC_HARDER; 2608 /* 2609 * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the 2610 * comment for __cpuset_node_allowed(). 2611 */ 2612 alloc_flags &= ~ALLOC_CPUSET; 2613 } else if (unlikely(rt_task(current)) && !in_interrupt()) 2614 alloc_flags |= ALLOC_HARDER; 2615 2616 if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) { 2617 if (gfp_mask & __GFP_MEMALLOC) 2618 alloc_flags |= ALLOC_NO_WATERMARKS; 2619 else if (in_serving_softirq() && (current->flags & PF_MEMALLOC)) 2620 alloc_flags |= ALLOC_NO_WATERMARKS; 2621 else if (!in_interrupt() && 2622 ((current->flags & PF_MEMALLOC) || 2623 unlikely(test_thread_flag(TIF_MEMDIE)))) 2624 alloc_flags |= ALLOC_NO_WATERMARKS; 2625 } 2626 #ifdef CONFIG_CMA 2627 if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE) 2628 alloc_flags |= ALLOC_CMA; 2629 #endif 2630 return alloc_flags; 2631 } 2632 2633 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask) 2634 { 2635 return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS); 2636 } 2637 2638 static inline struct page * 2639 __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, 2640 struct zonelist *zonelist, enum zone_type high_zoneidx, 2641 nodemask_t *nodemask, struct zone *preferred_zone, 2642 int classzone_idx, int migratetype) 2643 { 2644 const gfp_t wait = gfp_mask & __GFP_WAIT; 2645 struct page *page = NULL; 2646 int alloc_flags; 2647 unsigned long pages_reclaimed = 0; 2648 unsigned long did_some_progress; 2649 enum migrate_mode migration_mode = MIGRATE_ASYNC; 2650 bool deferred_compaction = false; 2651 int contended_compaction = COMPACT_CONTENDED_NONE; 2652 2653 /* 2654 * In the slowpath, we sanity check order to avoid ever trying to 2655 * reclaim >= MAX_ORDER areas which will never succeed. Callers may 2656 * be using allocators in order of preference for an area that is 2657 * too large. 2658 */ 2659 if (order >= MAX_ORDER) { 2660 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN)); 2661 return NULL; 2662 } 2663 2664 /* 2665 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and 2666 * __GFP_NOWARN set) should not cause reclaim since the subsystem 2667 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim 2668 * using a larger set of nodes after it has established that the 2669 * allowed per node queues are empty and that nodes are 2670 * over allocated. 2671 */ 2672 if (IS_ENABLED(CONFIG_NUMA) && 2673 (gfp_mask & GFP_THISNODE) == GFP_THISNODE) 2674 goto nopage; 2675 2676 retry: 2677 if (!(gfp_mask & __GFP_NO_KSWAPD)) 2678 wake_all_kswapds(order, zonelist, high_zoneidx, 2679 preferred_zone, nodemask); 2680 2681 /* 2682 * OK, we're below the kswapd watermark and have kicked background 2683 * reclaim. Now things get more complex, so set up alloc_flags according 2684 * to how we want to proceed. 2685 */ 2686 alloc_flags = gfp_to_alloc_flags(gfp_mask); 2687 2688 /* 2689 * Find the true preferred zone if the allocation is unconstrained by 2690 * cpusets. 2691 */ 2692 if (!(alloc_flags & ALLOC_CPUSET) && !nodemask) { 2693 struct zoneref *preferred_zoneref; 2694 preferred_zoneref = first_zones_zonelist(zonelist, high_zoneidx, 2695 NULL, &preferred_zone); 2696 classzone_idx = zonelist_zone_idx(preferred_zoneref); 2697 } 2698 2699 /* This is the last chance, in general, before the goto nopage. */ 2700 page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, 2701 high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS, 2702 preferred_zone, classzone_idx, migratetype); 2703 if (page) 2704 goto got_pg; 2705 2706 /* Allocate without watermarks if the context allows */ 2707 if (alloc_flags & ALLOC_NO_WATERMARKS) { 2708 /* 2709 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds 2710 * the allocation is high priority and these type of 2711 * allocations are system rather than user orientated 2712 */ 2713 zonelist = node_zonelist(numa_node_id(), gfp_mask); 2714 2715 page = __alloc_pages_high_priority(gfp_mask, order, 2716 zonelist, high_zoneidx, nodemask, 2717 preferred_zone, classzone_idx, migratetype); 2718 if (page) { 2719 goto got_pg; 2720 } 2721 } 2722 2723 /* Atomic allocations - we can't balance anything */ 2724 if (!wait) { 2725 /* 2726 * All existing users of the deprecated __GFP_NOFAIL are 2727 * blockable, so warn of any new users that actually allow this 2728 * type of allocation to fail. 2729 */ 2730 WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL); 2731 goto nopage; 2732 } 2733 2734 /* Avoid recursion of direct reclaim */ 2735 if (current->flags & PF_MEMALLOC) 2736 goto nopage; 2737 2738 /* Avoid allocations with no watermarks from looping endlessly */ 2739 if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL)) 2740 goto nopage; 2741 2742 /* 2743 * Try direct compaction. The first pass is asynchronous. Subsequent 2744 * attempts after direct reclaim are synchronous 2745 */ 2746 page = __alloc_pages_direct_compact(gfp_mask, order, zonelist, 2747 high_zoneidx, nodemask, alloc_flags, 2748 preferred_zone, 2749 classzone_idx, migratetype, 2750 migration_mode, &contended_compaction, 2751 &deferred_compaction); 2752 if (page) 2753 goto got_pg; 2754 2755 /* Checks for THP-specific high-order allocations */ 2756 if ((gfp_mask & GFP_TRANSHUGE) == GFP_TRANSHUGE) { 2757 /* 2758 * If compaction is deferred for high-order allocations, it is 2759 * because sync compaction recently failed. If this is the case 2760 * and the caller requested a THP allocation, we do not want 2761 * to heavily disrupt the system, so we fail the allocation 2762 * instead of entering direct reclaim. 2763 */ 2764 if (deferred_compaction) 2765 goto nopage; 2766 2767 /* 2768 * In all zones where compaction was attempted (and not 2769 * deferred or skipped), lock contention has been detected. 2770 * For THP allocation we do not want to disrupt the others 2771 * so we fallback to base pages instead. 2772 */ 2773 if (contended_compaction == COMPACT_CONTENDED_LOCK) 2774 goto nopage; 2775 2776 /* 2777 * If compaction was aborted due to need_resched(), we do not 2778 * want to further increase allocation latency, unless it is 2779 * khugepaged trying to collapse. 2780 */ 2781 if (contended_compaction == COMPACT_CONTENDED_SCHED 2782 && !(current->flags & PF_KTHREAD)) 2783 goto nopage; 2784 } 2785 2786 /* 2787 * It can become very expensive to allocate transparent hugepages at 2788 * fault, so use asynchronous memory compaction for THP unless it is 2789 * khugepaged trying to collapse. 2790 */ 2791 if ((gfp_mask & GFP_TRANSHUGE) != GFP_TRANSHUGE || 2792 (current->flags & PF_KTHREAD)) 2793 migration_mode = MIGRATE_SYNC_LIGHT; 2794 2795 /* Try direct reclaim and then allocating */ 2796 page = __alloc_pages_direct_reclaim(gfp_mask, order, 2797 zonelist, high_zoneidx, 2798 nodemask, 2799 alloc_flags, preferred_zone, 2800 classzone_idx, migratetype, 2801 &did_some_progress); 2802 if (page) 2803 goto got_pg; 2804 2805 /* Check if we should retry the allocation */ 2806 pages_reclaimed += did_some_progress; 2807 if (should_alloc_retry(gfp_mask, order, did_some_progress, 2808 pages_reclaimed)) { 2809 /* 2810 * If we fail to make progress by freeing individual 2811 * pages, but the allocation wants us to keep going, 2812 * start OOM killing tasks. 2813 */ 2814 if (!did_some_progress) { 2815 page = __alloc_pages_may_oom(gfp_mask, order, zonelist, 2816 high_zoneidx, nodemask, 2817 preferred_zone, classzone_idx, 2818 migratetype,&did_some_progress); 2819 if (page) 2820 goto got_pg; 2821 if (!did_some_progress) 2822 goto nopage; 2823 } 2824 /* Wait for some write requests to complete then retry */ 2825 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50); 2826 goto retry; 2827 } else { 2828 /* 2829 * High-order allocations do not necessarily loop after 2830 * direct reclaim and reclaim/compaction depends on compaction 2831 * being called after reclaim so call directly if necessary 2832 */ 2833 page = __alloc_pages_direct_compact(gfp_mask, order, zonelist, 2834 high_zoneidx, nodemask, alloc_flags, 2835 preferred_zone, 2836 classzone_idx, migratetype, 2837 migration_mode, &contended_compaction, 2838 &deferred_compaction); 2839 if (page) 2840 goto got_pg; 2841 } 2842 2843 nopage: 2844 warn_alloc_failed(gfp_mask, order, NULL); 2845 return page; 2846 got_pg: 2847 if (kmemcheck_enabled) 2848 kmemcheck_pagealloc_alloc(page, order, gfp_mask); 2849 2850 return page; 2851 } 2852 2853 /* 2854 * This is the 'heart' of the zoned buddy allocator. 2855 */ 2856 struct page * 2857 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, 2858 struct zonelist *zonelist, nodemask_t *nodemask) 2859 { 2860 enum zone_type high_zoneidx = gfp_zone(gfp_mask); 2861 struct zone *preferred_zone; 2862 struct zoneref *preferred_zoneref; 2863 struct page *page = NULL; 2864 int migratetype = gfpflags_to_migratetype(gfp_mask); 2865 unsigned int cpuset_mems_cookie; 2866 int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR; 2867 int classzone_idx; 2868 2869 gfp_mask &= gfp_allowed_mask; 2870 2871 lockdep_trace_alloc(gfp_mask); 2872 2873 might_sleep_if(gfp_mask & __GFP_WAIT); 2874 2875 if (should_fail_alloc_page(gfp_mask, order)) 2876 return NULL; 2877 2878 /* 2879 * Check the zones suitable for the gfp_mask contain at least one 2880 * valid zone. It's possible to have an empty zonelist as a result 2881 * of GFP_THISNODE and a memoryless node 2882 */ 2883 if (unlikely(!zonelist->_zonerefs->zone)) 2884 return NULL; 2885 2886 if (IS_ENABLED(CONFIG_CMA) && migratetype == MIGRATE_MOVABLE) 2887 alloc_flags |= ALLOC_CMA; 2888 2889 retry_cpuset: 2890 cpuset_mems_cookie = read_mems_allowed_begin(); 2891 2892 /* The preferred zone is used for statistics later */ 2893 preferred_zoneref = first_zones_zonelist(zonelist, high_zoneidx, 2894 nodemask ? : &cpuset_current_mems_allowed, 2895 &preferred_zone); 2896 if (!preferred_zone) 2897 goto out; 2898 classzone_idx = zonelist_zone_idx(preferred_zoneref); 2899 2900 /* First allocation attempt */ 2901 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order, 2902 zonelist, high_zoneidx, alloc_flags, 2903 preferred_zone, classzone_idx, migratetype); 2904 if (unlikely(!page)) { 2905 /* 2906 * Runtime PM, block IO and its error handling path 2907 * can deadlock because I/O on the device might not 2908 * complete. 2909 */ 2910 gfp_mask = memalloc_noio_flags(gfp_mask); 2911 page = __alloc_pages_slowpath(gfp_mask, order, 2912 zonelist, high_zoneidx, nodemask, 2913 preferred_zone, classzone_idx, migratetype); 2914 } 2915 2916 trace_mm_page_alloc(page, order, gfp_mask, migratetype); 2917 2918 out: 2919 /* 2920 * When updating a task's mems_allowed, it is possible to race with 2921 * parallel threads in such a way that an allocation can fail while 2922 * the mask is being updated. If a page allocation is about to fail, 2923 * check if the cpuset changed during allocation and if so, retry. 2924 */ 2925 if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie))) 2926 goto retry_cpuset; 2927 2928 return page; 2929 } 2930 EXPORT_SYMBOL(__alloc_pages_nodemask); 2931 2932 /* 2933 * Common helper functions. 2934 */ 2935 unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order) 2936 { 2937 struct page *page; 2938 2939 /* 2940 * __get_free_pages() returns a 32-bit address, which cannot represent 2941 * a highmem page 2942 */ 2943 VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0); 2944 2945 page = alloc_pages(gfp_mask, order); 2946 if (!page) 2947 return 0; 2948 return (unsigned long) page_address(page); 2949 } 2950 EXPORT_SYMBOL(__get_free_pages); 2951 2952 unsigned long get_zeroed_page(gfp_t gfp_mask) 2953 { 2954 return __get_free_pages(gfp_mask | __GFP_ZERO, 0); 2955 } 2956 EXPORT_SYMBOL(get_zeroed_page); 2957 2958 void __free_pages(struct page *page, unsigned int order) 2959 { 2960 if (put_page_testzero(page)) { 2961 if (order == 0) 2962 free_hot_cold_page(page, false); 2963 else 2964 __free_pages_ok(page, order); 2965 } 2966 } 2967 2968 EXPORT_SYMBOL(__free_pages); 2969 2970 void free_pages(unsigned long addr, unsigned int order) 2971 { 2972 if (addr != 0) { 2973 VM_BUG_ON(!virt_addr_valid((void *)addr)); 2974 __free_pages(virt_to_page((void *)addr), order); 2975 } 2976 } 2977 2978 EXPORT_SYMBOL(free_pages); 2979 2980 /* 2981 * alloc_kmem_pages charges newly allocated pages to the kmem resource counter 2982 * of the current memory cgroup. 2983 * 2984 * It should be used when the caller would like to use kmalloc, but since the 2985 * allocation is large, it has to fall back to the page allocator. 2986 */ 2987 struct page *alloc_kmem_pages(gfp_t gfp_mask, unsigned int order) 2988 { 2989 struct page *page; 2990 struct mem_cgroup *memcg = NULL; 2991 2992 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order)) 2993 return NULL; 2994 page = alloc_pages(gfp_mask, order); 2995 memcg_kmem_commit_charge(page, memcg, order); 2996 return page; 2997 } 2998 2999 struct page *alloc_kmem_pages_node(int nid, gfp_t gfp_mask, unsigned int order) 3000 { 3001 struct page *page; 3002 struct mem_cgroup *memcg = NULL; 3003 3004 if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order)) 3005 return NULL; 3006 page = alloc_pages_node(nid, gfp_mask, order); 3007 memcg_kmem_commit_charge(page, memcg, order); 3008 return page; 3009 } 3010 3011 /* 3012 * __free_kmem_pages and free_kmem_pages will free pages allocated with 3013 * alloc_kmem_pages. 3014 */ 3015 void __free_kmem_pages(struct page *page, unsigned int order) 3016 { 3017 memcg_kmem_uncharge_pages(page, order); 3018 __free_pages(page, order); 3019 } 3020 3021 void free_kmem_pages(unsigned long addr, unsigned int order) 3022 { 3023 if (addr != 0) { 3024 VM_BUG_ON(!virt_addr_valid((void *)addr)); 3025 __free_kmem_pages(virt_to_page((void *)addr), order); 3026 } 3027 } 3028 3029 static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size) 3030 { 3031 if (addr) { 3032 unsigned long alloc_end = addr + (PAGE_SIZE << order); 3033 unsigned long used = addr + PAGE_ALIGN(size); 3034 3035 split_page(virt_to_page((void *)addr), order); 3036 while (used < alloc_end) { 3037 free_page(used); 3038 used += PAGE_SIZE; 3039 } 3040 } 3041 return (void *)addr; 3042 } 3043 3044 /** 3045 * alloc_pages_exact - allocate an exact number physically-contiguous pages. 3046 * @size: the number of bytes to allocate 3047 * @gfp_mask: GFP flags for the allocation 3048 * 3049 * This function is similar to alloc_pages(), except that it allocates the 3050 * minimum number of pages to satisfy the request. alloc_pages() can only 3051 * allocate memory in power-of-two pages. 3052 * 3053 * This function is also limited by MAX_ORDER. 3054 * 3055 * Memory allocated by this function must be released by free_pages_exact(). 3056 */ 3057 void *alloc_pages_exact(size_t size, gfp_t gfp_mask) 3058 { 3059 unsigned int order = get_order(size); 3060 unsigned long addr; 3061 3062 addr = __get_free_pages(gfp_mask, order); 3063 return make_alloc_exact(addr, order, size); 3064 } 3065 EXPORT_SYMBOL(alloc_pages_exact); 3066 3067 /** 3068 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous 3069 * pages on a node. 3070 * @nid: the preferred node ID where memory should be allocated 3071 * @size: the number of bytes to allocate 3072 * @gfp_mask: GFP flags for the allocation 3073 * 3074 * Like alloc_pages_exact(), but try to allocate on node nid first before falling 3075 * back. 3076 * Note this is not alloc_pages_exact_node() which allocates on a specific node, 3077 * but is not exact. 3078 */ 3079 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask) 3080 { 3081 unsigned order = get_order(size); 3082 struct page *p = alloc_pages_node(nid, gfp_mask, order); 3083 if (!p) 3084 return NULL; 3085 return make_alloc_exact((unsigned long)page_address(p), order, size); 3086 } 3087 3088 /** 3089 * free_pages_exact - release memory allocated via alloc_pages_exact() 3090 * @virt: the value returned by alloc_pages_exact. 3091 * @size: size of allocation, same value as passed to alloc_pages_exact(). 3092 * 3093 * Release the memory allocated by a previous call to alloc_pages_exact. 3094 */ 3095 void free_pages_exact(void *virt, size_t size) 3096 { 3097 unsigned long addr = (unsigned long)virt; 3098 unsigned long end = addr + PAGE_ALIGN(size); 3099 3100 while (addr < end) { 3101 free_page(addr); 3102 addr += PAGE_SIZE; 3103 } 3104 } 3105 EXPORT_SYMBOL(free_pages_exact); 3106 3107 /** 3108 * nr_free_zone_pages - count number of pages beyond high watermark 3109 * @offset: The zone index of the highest zone 3110 * 3111 * nr_free_zone_pages() counts the number of counts pages which are beyond the 3112 * high watermark within all zones at or below a given zone index. For each 3113 * zone, the number of pages is calculated as: 3114 * managed_pages - high_pages 3115 */ 3116 static unsigned long nr_free_zone_pages(int offset) 3117 { 3118 struct zoneref *z; 3119 struct zone *zone; 3120 3121 /* Just pick one node, since fallback list is circular */ 3122 unsigned long sum = 0; 3123 3124 struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); 3125 3126 for_each_zone_zonelist(zone, z, zonelist, offset) { 3127 unsigned long size = zone->managed_pages; 3128 unsigned long high = high_wmark_pages(zone); 3129 if (size > high) 3130 sum += size - high; 3131 } 3132 3133 return sum; 3134 } 3135 3136 /** 3137 * nr_free_buffer_pages - count number of pages beyond high watermark 3138 * 3139 * nr_free_buffer_pages() counts the number of pages which are beyond the high 3140 * watermark within ZONE_DMA and ZONE_NORMAL. 3141 */ 3142 unsigned long nr_free_buffer_pages(void) 3143 { 3144 return nr_free_zone_pages(gfp_zone(GFP_USER)); 3145 } 3146 EXPORT_SYMBOL_GPL(nr_free_buffer_pages); 3147 3148 /** 3149 * nr_free_pagecache_pages - count number of pages beyond high watermark 3150 * 3151 * nr_free_pagecache_pages() counts the number of pages which are beyond the 3152 * high watermark within all zones. 3153 */ 3154 unsigned long nr_free_pagecache_pages(void) 3155 { 3156 return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); 3157 } 3158 3159 static inline void show_node(struct zone *zone) 3160 { 3161 if (IS_ENABLED(CONFIG_NUMA)) 3162 printk("Node %d ", zone_to_nid(zone)); 3163 } 3164 3165 void si_meminfo(struct sysinfo *val) 3166 { 3167 val->totalram = totalram_pages; 3168 val->sharedram = global_page_state(NR_SHMEM); 3169 val->freeram = global_page_state(NR_FREE_PAGES); 3170 val->bufferram = nr_blockdev_pages(); 3171 val->totalhigh = totalhigh_pages; 3172 val->freehigh = nr_free_highpages(); 3173 val->mem_unit = PAGE_SIZE; 3174 } 3175 3176 EXPORT_SYMBOL(si_meminfo); 3177 3178 #ifdef CONFIG_NUMA 3179 void si_meminfo_node(struct sysinfo *val, int nid) 3180 { 3181 int zone_type; /* needs to be signed */ 3182 unsigned long managed_pages = 0; 3183 pg_data_t *pgdat = NODE_DATA(nid); 3184 3185 for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) 3186 managed_pages += pgdat->node_zones[zone_type].managed_pages; 3187 val->totalram = managed_pages; 3188 val->sharedram = node_page_state(nid, NR_SHMEM); 3189 val->freeram = node_page_state(nid, NR_FREE_PAGES); 3190 #ifdef CONFIG_HIGHMEM 3191 val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].managed_pages; 3192 val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM], 3193 NR_FREE_PAGES); 3194 #else 3195 val->totalhigh = 0; 3196 val->freehigh = 0; 3197 #endif 3198 val->mem_unit = PAGE_SIZE; 3199 } 3200 #endif 3201 3202 /* 3203 * Determine whether the node should be displayed or not, depending on whether 3204 * SHOW_MEM_FILTER_NODES was passed to show_free_areas(). 3205 */ 3206 bool skip_free_areas_node(unsigned int flags, int nid) 3207 { 3208 bool ret = false; 3209 unsigned int cpuset_mems_cookie; 3210 3211 if (!(flags & SHOW_MEM_FILTER_NODES)) 3212 goto out; 3213 3214 do { 3215 cpuset_mems_cookie = read_mems_allowed_begin(); 3216 ret = !node_isset(nid, cpuset_current_mems_allowed); 3217 } while (read_mems_allowed_retry(cpuset_mems_cookie)); 3218 out: 3219 return ret; 3220 } 3221 3222 #define K(x) ((x) << (PAGE_SHIFT-10)) 3223 3224 static void show_migration_types(unsigned char type) 3225 { 3226 static const char types[MIGRATE_TYPES] = { 3227 [MIGRATE_UNMOVABLE] = 'U', 3228 [MIGRATE_RECLAIMABLE] = 'E', 3229 [MIGRATE_MOVABLE] = 'M', 3230 [MIGRATE_RESERVE] = 'R', 3231 #ifdef CONFIG_CMA 3232 [MIGRATE_CMA] = 'C', 3233 #endif 3234 #ifdef CONFIG_MEMORY_ISOLATION 3235 [MIGRATE_ISOLATE] = 'I', 3236 #endif 3237 }; 3238 char tmp[MIGRATE_TYPES + 1]; 3239 char *p = tmp; 3240 int i; 3241 3242 for (i = 0; i < MIGRATE_TYPES; i++) { 3243 if (type & (1 << i)) 3244 *p++ = types[i]; 3245 } 3246 3247 *p = '\0'; 3248 printk("(%s) ", tmp); 3249 } 3250 3251 /* 3252 * Show free area list (used inside shift_scroll-lock stuff) 3253 * We also calculate the percentage fragmentation. We do this by counting the 3254 * memory on each free list with the exception of the first item on the list. 3255 * Suppresses nodes that are not allowed by current's cpuset if 3256 * SHOW_MEM_FILTER_NODES is passed. 3257 */ 3258 void show_free_areas(unsigned int filter) 3259 { 3260 int cpu; 3261 struct zone *zone; 3262 3263 for_each_populated_zone(zone) { 3264 if (skip_free_areas_node(filter, zone_to_nid(zone))) 3265 continue; 3266 show_node(zone); 3267 printk("%s per-cpu:\n", zone->name); 3268 3269 for_each_online_cpu(cpu) { 3270 struct per_cpu_pageset *pageset; 3271 3272 pageset = per_cpu_ptr(zone->pageset, cpu); 3273 3274 printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n", 3275 cpu, pageset->pcp.high, 3276 pageset->pcp.batch, pageset->pcp.count); 3277 } 3278 } 3279 3280 printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n" 3281 " active_file:%lu inactive_file:%lu isolated_file:%lu\n" 3282 " unevictable:%lu" 3283 " dirty:%lu writeback:%lu unstable:%lu\n" 3284 " free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n" 3285 " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n" 3286 " free_cma:%lu\n", 3287 global_page_state(NR_ACTIVE_ANON), 3288 global_page_state(NR_INACTIVE_ANON), 3289 global_page_state(NR_ISOLATED_ANON), 3290 global_page_state(NR_ACTIVE_FILE), 3291 global_page_state(NR_INACTIVE_FILE), 3292 global_page_state(NR_ISOLATED_FILE), 3293 global_page_state(NR_UNEVICTABLE), 3294 global_page_state(NR_FILE_DIRTY), 3295 global_page_state(NR_WRITEBACK), 3296 global_page_state(NR_UNSTABLE_NFS), 3297 global_page_state(NR_FREE_PAGES), 3298 global_page_state(NR_SLAB_RECLAIMABLE), 3299 global_page_state(NR_SLAB_UNRECLAIMABLE), 3300 global_page_state(NR_FILE_MAPPED), 3301 global_page_state(NR_SHMEM), 3302 global_page_state(NR_PAGETABLE), 3303 global_page_state(NR_BOUNCE), 3304 global_page_state(NR_FREE_CMA_PAGES)); 3305 3306 for_each_populated_zone(zone) { 3307 int i; 3308 3309 if (skip_free_areas_node(filter, zone_to_nid(zone))) 3310 continue; 3311 show_node(zone); 3312 printk("%s" 3313 " free:%lukB" 3314 " min:%lukB" 3315 " low:%lukB" 3316 " high:%lukB" 3317 " active_anon:%lukB" 3318 " inactive_anon:%lukB" 3319 " active_file:%lukB" 3320 " inactive_file:%lukB" 3321 " unevictable:%lukB" 3322 " isolated(anon):%lukB" 3323 " isolated(file):%lukB" 3324 " present:%lukB" 3325 " managed:%lukB" 3326 " mlocked:%lukB" 3327 " dirty:%lukB" 3328 " writeback:%lukB" 3329 " mapped:%lukB" 3330 " shmem:%lukB" 3331 " slab_reclaimable:%lukB" 3332 " slab_unreclaimable:%lukB" 3333 " kernel_stack:%lukB" 3334 " pagetables:%lukB" 3335 " unstable:%lukB" 3336 " bounce:%lukB" 3337 " free_cma:%lukB" 3338 " writeback_tmp:%lukB" 3339 " pages_scanned:%lu" 3340 " all_unreclaimable? %s" 3341 "\n", 3342 zone->name, 3343 K(zone_page_state(zone, NR_FREE_PAGES)), 3344 K(min_wmark_pages(zone)), 3345 K(low_wmark_pages(zone)), 3346 K(high_wmark_pages(zone)), 3347 K(zone_page_state(zone, NR_ACTIVE_ANON)), 3348 K(zone_page_state(zone, NR_INACTIVE_ANON)), 3349 K(zone_page_state(zone, NR_ACTIVE_FILE)), 3350 K(zone_page_state(zone, NR_INACTIVE_FILE)), 3351 K(zone_page_state(zone, NR_UNEVICTABLE)), 3352 K(zone_page_state(zone, NR_ISOLATED_ANON)), 3353 K(zone_page_state(zone, NR_ISOLATED_FILE)), 3354 K(zone->present_pages), 3355 K(zone->managed_pages), 3356 K(zone_page_state(zone, NR_MLOCK)), 3357 K(zone_page_state(zone, NR_FILE_DIRTY)), 3358 K(zone_page_state(zone, NR_WRITEBACK)), 3359 K(zone_page_state(zone, NR_FILE_MAPPED)), 3360 K(zone_page_state(zone, NR_SHMEM)), 3361 K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)), 3362 K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)), 3363 zone_page_state(zone, NR_KERNEL_STACK) * 3364 THREAD_SIZE / 1024, 3365 K(zone_page_state(zone, NR_PAGETABLE)), 3366 K(zone_page_state(zone, NR_UNSTABLE_NFS)), 3367 K(zone_page_state(zone, NR_BOUNCE)), 3368 K(zone_page_state(zone, NR_FREE_CMA_PAGES)), 3369 K(zone_page_state(zone, NR_WRITEBACK_TEMP)), 3370 K(zone_page_state(zone, NR_PAGES_SCANNED)), 3371 (!zone_reclaimable(zone) ? "yes" : "no") 3372 ); 3373 printk("lowmem_reserve[]:"); 3374 for (i = 0; i < MAX_NR_ZONES; i++) 3375 printk(" %ld", zone->lowmem_reserve[i]); 3376 printk("\n"); 3377 } 3378 3379 for_each_populated_zone(zone) { 3380 unsigned long nr[MAX_ORDER], flags, order, total = 0; 3381 unsigned char types[MAX_ORDER]; 3382 3383 if (skip_free_areas_node(filter, zone_to_nid(zone))) 3384 continue; 3385 show_node(zone); 3386 printk("%s: ", zone->name); 3387 3388 spin_lock_irqsave(&zone->lock, flags); 3389 for (order = 0; order < MAX_ORDER; order++) { 3390 struct free_area *area = &zone->free_area[order]; 3391 int type; 3392 3393 nr[order] = area->nr_free; 3394 total += nr[order] << order; 3395 3396 types[order] = 0; 3397 for (type = 0; type < MIGRATE_TYPES; type++) { 3398 if (!list_empty(&area->free_list[type])) 3399 types[order] |= 1 << type; 3400 } 3401 } 3402 spin_unlock_irqrestore(&zone->lock, flags); 3403 for (order = 0; order < MAX_ORDER; order++) { 3404 printk("%lu*%lukB ", nr[order], K(1UL) << order); 3405 if (nr[order]) 3406 show_migration_types(types[order]); 3407 } 3408 printk("= %lukB\n", K(total)); 3409 } 3410 3411 hugetlb_show_meminfo(); 3412 3413 printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES)); 3414 3415 show_swap_cache_info(); 3416 } 3417 3418 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) 3419 { 3420 zoneref->zone = zone; 3421 zoneref->zone_idx = zone_idx(zone); 3422 } 3423 3424 /* 3425 * Builds allocation fallback zone lists. 3426 * 3427 * Add all populated zones of a node to the zonelist. 3428 */ 3429 static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, 3430 int nr_zones) 3431 { 3432 struct zone *zone; 3433 enum zone_type zone_type = MAX_NR_ZONES; 3434 3435 do { 3436 zone_type--; 3437 zone = pgdat->node_zones + zone_type; 3438 if (populated_zone(zone)) { 3439 zoneref_set_zone(zone, 3440 &zonelist->_zonerefs[nr_zones++]); 3441 check_highest_zone(zone_type); 3442 } 3443 } while (zone_type); 3444 3445 return nr_zones; 3446 } 3447 3448 3449 /* 3450 * zonelist_order: 3451 * 0 = automatic detection of better ordering. 3452 * 1 = order by ([node] distance, -zonetype) 3453 * 2 = order by (-zonetype, [node] distance) 3454 * 3455 * If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create 3456 * the same zonelist. So only NUMA can configure this param. 3457 */ 3458 #define ZONELIST_ORDER_DEFAULT 0 3459 #define ZONELIST_ORDER_NODE 1 3460 #define ZONELIST_ORDER_ZONE 2 3461 3462 /* zonelist order in the kernel. 3463 * set_zonelist_order() will set this to NODE or ZONE. 3464 */ 3465 static int current_zonelist_order = ZONELIST_ORDER_DEFAULT; 3466 static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"}; 3467 3468 3469 #ifdef CONFIG_NUMA 3470 /* The value user specified ....changed by config */ 3471 static int user_zonelist_order = ZONELIST_ORDER_DEFAULT; 3472 /* string for sysctl */ 3473 #define NUMA_ZONELIST_ORDER_LEN 16 3474 char numa_zonelist_order[16] = "default"; 3475 3476 /* 3477 * interface for configure zonelist ordering. 3478 * command line option "numa_zonelist_order" 3479 * = "[dD]efault - default, automatic configuration. 3480 * = "[nN]ode - order by node locality, then by zone within node 3481 * = "[zZ]one - order by zone, then by locality within zone 3482 */ 3483 3484 static int __parse_numa_zonelist_order(char *s) 3485 { 3486 if (*s == 'd' || *s == 'D') { 3487 user_zonelist_order = ZONELIST_ORDER_DEFAULT; 3488 } else if (*s == 'n' || *s == 'N') { 3489 user_zonelist_order = ZONELIST_ORDER_NODE; 3490 } else if (*s == 'z' || *s == 'Z') { 3491 user_zonelist_order = ZONELIST_ORDER_ZONE; 3492 } else { 3493 printk(KERN_WARNING 3494 "Ignoring invalid numa_zonelist_order value: " 3495 "%s\n", s); 3496 return -EINVAL; 3497 } 3498 return 0; 3499 } 3500 3501 static __init int setup_numa_zonelist_order(char *s) 3502 { 3503 int ret; 3504 3505 if (!s) 3506 return 0; 3507 3508 ret = __parse_numa_zonelist_order(s); 3509 if (ret == 0) 3510 strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN); 3511 3512 return ret; 3513 } 3514 early_param("numa_zonelist_order", setup_numa_zonelist_order); 3515 3516 /* 3517 * sysctl handler for numa_zonelist_order 3518 */ 3519 int numa_zonelist_order_handler(struct ctl_table *table, int write, 3520 void __user *buffer, size_t *length, 3521 loff_t *ppos) 3522 { 3523 char saved_string[NUMA_ZONELIST_ORDER_LEN]; 3524 int ret; 3525 static DEFINE_MUTEX(zl_order_mutex); 3526 3527 mutex_lock(&zl_order_mutex); 3528 if (write) { 3529 if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) { 3530 ret = -EINVAL; 3531 goto out; 3532 } 3533 strcpy(saved_string, (char *)table->data); 3534 } 3535 ret = proc_dostring(table, write, buffer, length, ppos); 3536 if (ret) 3537 goto out; 3538 if (write) { 3539 int oldval = user_zonelist_order; 3540 3541 ret = __parse_numa_zonelist_order((char *)table->data); 3542 if (ret) { 3543 /* 3544 * bogus value. restore saved string 3545 */ 3546 strncpy((char *)table->data, saved_string, 3547 NUMA_ZONELIST_ORDER_LEN); 3548 user_zonelist_order = oldval; 3549 } else if (oldval != user_zonelist_order) { 3550 mutex_lock(&zonelists_mutex); 3551 build_all_zonelists(NULL, NULL); 3552 mutex_unlock(&zonelists_mutex); 3553 } 3554 } 3555 out: 3556 mutex_unlock(&zl_order_mutex); 3557 return ret; 3558 } 3559 3560 3561 #define MAX_NODE_LOAD (nr_online_nodes) 3562 static int node_load[MAX_NUMNODES]; 3563 3564 /** 3565 * find_next_best_node - find the next node that should appear in a given node's fallback list 3566 * @node: node whose fallback list we're appending 3567 * @used_node_mask: nodemask_t of already used nodes 3568 * 3569 * We use a number of factors to determine which is the next node that should 3570 * appear on a given node's fallback list. The node should not have appeared 3571 * already in @node's fallback list, and it should be the next closest node 3572 * according to the distance array (which contains arbitrary distance values 3573 * from each node to each node in the system), and should also prefer nodes 3574 * with no CPUs, since presumably they'll have very little allocation pressure 3575 * on them otherwise. 3576 * It returns -1 if no node is found. 3577 */ 3578 static int find_next_best_node(int node, nodemask_t *used_node_mask) 3579 { 3580 int n, val; 3581 int min_val = INT_MAX; 3582 int best_node = NUMA_NO_NODE; 3583 const struct cpumask *tmp = cpumask_of_node(0); 3584 3585 /* Use the local node if we haven't already */ 3586 if (!node_isset(node, *used_node_mask)) { 3587 node_set(node, *used_node_mask); 3588 return node; 3589 } 3590 3591 for_each_node_state(n, N_MEMORY) { 3592 3593 /* Don't want a node to appear more than once */ 3594 if (node_isset(n, *used_node_mask)) 3595 continue; 3596 3597 /* Use the distance array to find the distance */ 3598 val = node_distance(node, n); 3599 3600 /* Penalize nodes under us ("prefer the next node") */ 3601 val += (n < node); 3602 3603 /* Give preference to headless and unused nodes */ 3604 tmp = cpumask_of_node(n); 3605 if (!cpumask_empty(tmp)) 3606 val += PENALTY_FOR_NODE_WITH_CPUS; 3607 3608 /* Slight preference for less loaded node */ 3609 val *= (MAX_NODE_LOAD*MAX_NUMNODES); 3610 val += node_load[n]; 3611 3612 if (val < min_val) { 3613 min_val = val; 3614 best_node = n; 3615 } 3616 } 3617 3618 if (best_node >= 0) 3619 node_set(best_node, *used_node_mask); 3620 3621 return best_node; 3622 } 3623 3624 3625 /* 3626 * Build zonelists ordered by node and zones within node. 3627 * This results in maximum locality--normal zone overflows into local 3628 * DMA zone, if any--but risks exhausting DMA zone. 3629 */ 3630 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) 3631 { 3632 int j; 3633 struct zonelist *zonelist; 3634 3635 zonelist = &pgdat->node_zonelists[0]; 3636 for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++) 3637 ; 3638 j = build_zonelists_node(NODE_DATA(node), zonelist, j); 3639 zonelist->_zonerefs[j].zone = NULL; 3640 zonelist->_zonerefs[j].zone_idx = 0; 3641 } 3642 3643 /* 3644 * Build gfp_thisnode zonelists 3645 */ 3646 static void build_thisnode_zonelists(pg_data_t *pgdat) 3647 { 3648 int j; 3649 struct zonelist *zonelist; 3650 3651 zonelist = &pgdat->node_zonelists[1]; 3652 j = build_zonelists_node(pgdat, zonelist, 0); 3653 zonelist->_zonerefs[j].zone = NULL; 3654 zonelist->_zonerefs[j].zone_idx = 0; 3655 } 3656 3657 /* 3658 * Build zonelists ordered by zone and nodes within zones. 3659 * This results in conserving DMA zone[s] until all Normal memory is 3660 * exhausted, but results in overflowing to remote node while memory 3661 * may still exist in local DMA zone. 3662 */ 3663 static int node_order[MAX_NUMNODES]; 3664 3665 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) 3666 { 3667 int pos, j, node; 3668 int zone_type; /* needs to be signed */ 3669 struct zone *z; 3670 struct zonelist *zonelist; 3671 3672 zonelist = &pgdat->node_zonelists[0]; 3673 pos = 0; 3674 for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) { 3675 for (j = 0; j < nr_nodes; j++) { 3676 node = node_order[j]; 3677 z = &NODE_DATA(node)->node_zones[zone_type]; 3678 if (populated_zone(z)) { 3679 zoneref_set_zone(z, 3680 &zonelist->_zonerefs[pos++]); 3681 check_highest_zone(zone_type); 3682 } 3683 } 3684 } 3685 zonelist->_zonerefs[pos].zone = NULL; 3686 zonelist->_zonerefs[pos].zone_idx = 0; 3687 } 3688 3689 #if defined(CONFIG_64BIT) 3690 /* 3691 * Devices that require DMA32/DMA are relatively rare and do not justify a 3692 * penalty to every machine in case the specialised case applies. Default 3693 * to Node-ordering on 64-bit NUMA machines 3694 */ 3695 static int default_zonelist_order(void) 3696 { 3697 return ZONELIST_ORDER_NODE; 3698 } 3699 #else 3700 /* 3701 * On 32-bit, the Normal zone needs to be preserved for allocations accessible 3702 * by the kernel. If processes running on node 0 deplete the low memory zone 3703 * then reclaim will occur more frequency increasing stalls and potentially 3704 * be easier to OOM if a large percentage of the zone is under writeback or 3705 * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set. 3706 * Hence, default to zone ordering on 32-bit. 3707 */ 3708 static int default_zonelist_order(void) 3709 { 3710 return ZONELIST_ORDER_ZONE; 3711 } 3712 #endif /* CONFIG_64BIT */ 3713 3714 static void set_zonelist_order(void) 3715 { 3716 if (user_zonelist_order == ZONELIST_ORDER_DEFAULT) 3717 current_zonelist_order = default_zonelist_order(); 3718 else 3719 current_zonelist_order = user_zonelist_order; 3720 } 3721 3722 static void build_zonelists(pg_data_t *pgdat) 3723 { 3724 int j, node, load; 3725 enum zone_type i; 3726 nodemask_t used_mask; 3727 int local_node, prev_node; 3728 struct zonelist *zonelist; 3729 int order = current_zonelist_order; 3730 3731 /* initialize zonelists */ 3732 for (i = 0; i < MAX_ZONELISTS; i++) { 3733 zonelist = pgdat->node_zonelists + i; 3734 zonelist->_zonerefs[0].zone = NULL; 3735 zonelist->_zonerefs[0].zone_idx = 0; 3736 } 3737 3738 /* NUMA-aware ordering of nodes */ 3739 local_node = pgdat->node_id; 3740 load = nr_online_nodes; 3741 prev_node = local_node; 3742 nodes_clear(used_mask); 3743 3744 memset(node_order, 0, sizeof(node_order)); 3745 j = 0; 3746 3747 while ((node = find_next_best_node(local_node, &used_mask)) >= 0) { 3748 /* 3749 * We don't want to pressure a particular node. 3750 * So adding penalty to the first node in same 3751 * distance group to make it round-robin. 3752 */ 3753 if (node_distance(local_node, node) != 3754 node_distance(local_node, prev_node)) 3755 node_load[node] = load; 3756 3757 prev_node = node; 3758 load--; 3759 if (order == ZONELIST_ORDER_NODE) 3760 build_zonelists_in_node_order(pgdat, node); 3761 else 3762 node_order[j++] = node; /* remember order */ 3763 } 3764 3765 if (order == ZONELIST_ORDER_ZONE) { 3766 /* calculate node order -- i.e., DMA last! */ 3767 build_zonelists_in_zone_order(pgdat, j); 3768 } 3769 3770 build_thisnode_zonelists(pgdat); 3771 } 3772 3773 /* Construct the zonelist performance cache - see further mmzone.h */ 3774 static void build_zonelist_cache(pg_data_t *pgdat) 3775 { 3776 struct zonelist *zonelist; 3777 struct zonelist_cache *zlc; 3778 struct zoneref *z; 3779 3780 zonelist = &pgdat->node_zonelists[0]; 3781 zonelist->zlcache_ptr = zlc = &zonelist->zlcache; 3782 bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); 3783 for (z = zonelist->_zonerefs; z->zone; z++) 3784 zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z); 3785 } 3786 3787 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 3788 /* 3789 * Return node id of node used for "local" allocations. 3790 * I.e., first node id of first zone in arg node's generic zonelist. 3791 * Used for initializing percpu 'numa_mem', which is used primarily 3792 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist. 3793 */ 3794 int local_memory_node(int node) 3795 { 3796 struct zone *zone; 3797 3798 (void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL), 3799 gfp_zone(GFP_KERNEL), 3800 NULL, 3801 &zone); 3802 return zone->node; 3803 } 3804 #endif 3805 3806 #else /* CONFIG_NUMA */ 3807 3808 static void set_zonelist_order(void) 3809 { 3810 current_zonelist_order = ZONELIST_ORDER_ZONE; 3811 } 3812 3813 static void build_zonelists(pg_data_t *pgdat) 3814 { 3815 int node, local_node; 3816 enum zone_type j; 3817 struct zonelist *zonelist; 3818 3819 local_node = pgdat->node_id; 3820 3821 zonelist = &pgdat->node_zonelists[0]; 3822 j = build_zonelists_node(pgdat, zonelist, 0); 3823 3824 /* 3825 * Now we build the zonelist so that it contains the zones 3826 * of all the other nodes. 3827 * We don't want to pressure a particular node, so when 3828 * building the zones for node N, we make sure that the 3829 * zones coming right after the local ones are those from 3830 * node N+1 (modulo N) 3831 */ 3832 for (node = local_node + 1; node < MAX_NUMNODES; node++) { 3833 if (!node_online(node)) 3834 continue; 3835 j = build_zonelists_node(NODE_DATA(node), zonelist, j); 3836 } 3837 for (node = 0; node < local_node; node++) { 3838 if (!node_online(node)) 3839 continue; 3840 j = build_zonelists_node(NODE_DATA(node), zonelist, j); 3841 } 3842 3843 zonelist->_zonerefs[j].zone = NULL; 3844 zonelist->_zonerefs[j].zone_idx = 0; 3845 } 3846 3847 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ 3848 static void build_zonelist_cache(pg_data_t *pgdat) 3849 { 3850 pgdat->node_zonelists[0].zlcache_ptr = NULL; 3851 } 3852 3853 #endif /* CONFIG_NUMA */ 3854 3855 /* 3856 * Boot pageset table. One per cpu which is going to be used for all 3857 * zones and all nodes. The parameters will be set in such a way 3858 * that an item put on a list will immediately be handed over to 3859 * the buddy list. This is safe since pageset manipulation is done 3860 * with interrupts disabled. 3861 * 3862 * The boot_pagesets must be kept even after bootup is complete for 3863 * unused processors and/or zones. They do play a role for bootstrapping 3864 * hotplugged processors. 3865 * 3866 * zoneinfo_show() and maybe other functions do 3867 * not check if the processor is online before following the pageset pointer. 3868 * Other parts of the kernel may not check if the zone is available. 3869 */ 3870 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch); 3871 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset); 3872 static void setup_zone_pageset(struct zone *zone); 3873 3874 /* 3875 * Global mutex to protect against size modification of zonelists 3876 * as well as to serialize pageset setup for the new populated zone. 3877 */ 3878 DEFINE_MUTEX(zonelists_mutex); 3879 3880 /* return values int ....just for stop_machine() */ 3881 static int __build_all_zonelists(void *data) 3882 { 3883 int nid; 3884 int cpu; 3885 pg_data_t *self = data; 3886 3887 #ifdef CONFIG_NUMA 3888 memset(node_load, 0, sizeof(node_load)); 3889 #endif 3890 3891 if (self && !node_online(self->node_id)) { 3892 build_zonelists(self); 3893 build_zonelist_cache(self); 3894 } 3895 3896 for_each_online_node(nid) { 3897 pg_data_t *pgdat = NODE_DATA(nid); 3898 3899 build_zonelists(pgdat); 3900 build_zonelist_cache(pgdat); 3901 } 3902 3903 /* 3904 * Initialize the boot_pagesets that are going to be used 3905 * for bootstrapping processors. The real pagesets for 3906 * each zone will be allocated later when the per cpu 3907 * allocator is available. 3908 * 3909 * boot_pagesets are used also for bootstrapping offline 3910 * cpus if the system is already booted because the pagesets 3911 * are needed to initialize allocators on a specific cpu too. 3912 * F.e. the percpu allocator needs the page allocator which 3913 * needs the percpu allocator in order to allocate its pagesets 3914 * (a chicken-egg dilemma). 3915 */ 3916 for_each_possible_cpu(cpu) { 3917 setup_pageset(&per_cpu(boot_pageset, cpu), 0); 3918 3919 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 3920 /* 3921 * We now know the "local memory node" for each node-- 3922 * i.e., the node of the first zone in the generic zonelist. 3923 * Set up numa_mem percpu variable for on-line cpus. During 3924 * boot, only the boot cpu should be on-line; we'll init the 3925 * secondary cpus' numa_mem as they come on-line. During 3926 * node/memory hotplug, we'll fixup all on-line cpus. 3927 */ 3928 if (cpu_online(cpu)) 3929 set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu))); 3930 #endif 3931 } 3932 3933 return 0; 3934 } 3935 3936 /* 3937 * Called with zonelists_mutex held always 3938 * unless system_state == SYSTEM_BOOTING. 3939 */ 3940 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone) 3941 { 3942 set_zonelist_order(); 3943 3944 if (system_state == SYSTEM_BOOTING) { 3945 __build_all_zonelists(NULL); 3946 mminit_verify_zonelist(); 3947 cpuset_init_current_mems_allowed(); 3948 } else { 3949 #ifdef CONFIG_MEMORY_HOTPLUG 3950 if (zone) 3951 setup_zone_pageset(zone); 3952 #endif 3953 /* we have to stop all cpus to guarantee there is no user 3954 of zonelist */ 3955 stop_machine(__build_all_zonelists, pgdat, NULL); 3956 /* cpuset refresh routine should be here */ 3957 } 3958 vm_total_pages = nr_free_pagecache_pages(); 3959 /* 3960 * Disable grouping by mobility if the number of pages in the 3961 * system is too low to allow the mechanism to work. It would be 3962 * more accurate, but expensive to check per-zone. This check is 3963 * made on memory-hotadd so a system can start with mobility 3964 * disabled and enable it later 3965 */ 3966 if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES)) 3967 page_group_by_mobility_disabled = 1; 3968 else 3969 page_group_by_mobility_disabled = 0; 3970 3971 pr_info("Built %i zonelists in %s order, mobility grouping %s. " 3972 "Total pages: %ld\n", 3973 nr_online_nodes, 3974 zonelist_order_name[current_zonelist_order], 3975 page_group_by_mobility_disabled ? "off" : "on", 3976 vm_total_pages); 3977 #ifdef CONFIG_NUMA 3978 pr_info("Policy zone: %s\n", zone_names[policy_zone]); 3979 #endif 3980 } 3981 3982 /* 3983 * Helper functions to size the waitqueue hash table. 3984 * Essentially these want to choose hash table sizes sufficiently 3985 * large so that collisions trying to wait on pages are rare. 3986 * But in fact, the number of active page waitqueues on typical 3987 * systems is ridiculously low, less than 200. So this is even 3988 * conservative, even though it seems large. 3989 * 3990 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to 3991 * waitqueues, i.e. the size of the waitq table given the number of pages. 3992 */ 3993 #define PAGES_PER_WAITQUEUE 256 3994 3995 #ifndef CONFIG_MEMORY_HOTPLUG 3996 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 3997 { 3998 unsigned long size = 1; 3999 4000 pages /= PAGES_PER_WAITQUEUE; 4001 4002 while (size < pages) 4003 size <<= 1; 4004 4005 /* 4006 * Once we have dozens or even hundreds of threads sleeping 4007 * on IO we've got bigger problems than wait queue collision. 4008 * Limit the size of the wait table to a reasonable size. 4009 */ 4010 size = min(size, 4096UL); 4011 4012 return max(size, 4UL); 4013 } 4014 #else 4015 /* 4016 * A zone's size might be changed by hot-add, so it is not possible to determine 4017 * a suitable size for its wait_table. So we use the maximum size now. 4018 * 4019 * The max wait table size = 4096 x sizeof(wait_queue_head_t). ie: 4020 * 4021 * i386 (preemption config) : 4096 x 16 = 64Kbyte. 4022 * ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte. 4023 * ia64, x86-64 (preemption) : 4096 x 24 = 96Kbyte. 4024 * 4025 * The maximum entries are prepared when a zone's memory is (512K + 256) pages 4026 * or more by the traditional way. (See above). It equals: 4027 * 4028 * i386, x86-64, powerpc(4K page size) : = ( 2G + 1M)byte. 4029 * ia64(16K page size) : = ( 8G + 4M)byte. 4030 * powerpc (64K page size) : = (32G +16M)byte. 4031 */ 4032 static inline unsigned long wait_table_hash_nr_entries(unsigned long pages) 4033 { 4034 return 4096UL; 4035 } 4036 #endif 4037 4038 /* 4039 * This is an integer logarithm so that shifts can be used later 4040 * to extract the more random high bits from the multiplicative 4041 * hash function before the remainder is taken. 4042 */ 4043 static inline unsigned long wait_table_bits(unsigned long size) 4044 { 4045 return ffz(~size); 4046 } 4047 4048 /* 4049 * Check if a pageblock contains reserved pages 4050 */ 4051 static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn) 4052 { 4053 unsigned long pfn; 4054 4055 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 4056 if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn))) 4057 return 1; 4058 } 4059 return 0; 4060 } 4061 4062 /* 4063 * Mark a number of pageblocks as MIGRATE_RESERVE. The number 4064 * of blocks reserved is based on min_wmark_pages(zone). The memory within 4065 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes 4066 * higher will lead to a bigger reserve which will get freed as contiguous 4067 * blocks as reclaim kicks in 4068 */ 4069 static void setup_zone_migrate_reserve(struct zone *zone) 4070 { 4071 unsigned long start_pfn, pfn, end_pfn, block_end_pfn; 4072 struct page *page; 4073 unsigned long block_migratetype; 4074 int reserve; 4075 int old_reserve; 4076 4077 /* 4078 * Get the start pfn, end pfn and the number of blocks to reserve 4079 * We have to be careful to be aligned to pageblock_nr_pages to 4080 * make sure that we always check pfn_valid for the first page in 4081 * the block. 4082 */ 4083 start_pfn = zone->zone_start_pfn; 4084 end_pfn = zone_end_pfn(zone); 4085 start_pfn = roundup(start_pfn, pageblock_nr_pages); 4086 reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >> 4087 pageblock_order; 4088 4089 /* 4090 * Reserve blocks are generally in place to help high-order atomic 4091 * allocations that are short-lived. A min_free_kbytes value that 4092 * would result in more than 2 reserve blocks for atomic allocations 4093 * is assumed to be in place to help anti-fragmentation for the 4094 * future allocation of hugepages at runtime. 4095 */ 4096 reserve = min(2, reserve); 4097 old_reserve = zone->nr_migrate_reserve_block; 4098 4099 /* When memory hot-add, we almost always need to do nothing */ 4100 if (reserve == old_reserve) 4101 return; 4102 zone->nr_migrate_reserve_block = reserve; 4103 4104 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { 4105 if (!pfn_valid(pfn)) 4106 continue; 4107 page = pfn_to_page(pfn); 4108 4109 /* Watch out for overlapping nodes */ 4110 if (page_to_nid(page) != zone_to_nid(zone)) 4111 continue; 4112 4113 block_migratetype = get_pageblock_migratetype(page); 4114 4115 /* Only test what is necessary when the reserves are not met */ 4116 if (reserve > 0) { 4117 /* 4118 * Blocks with reserved pages will never free, skip 4119 * them. 4120 */ 4121 block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn); 4122 if (pageblock_is_reserved(pfn, block_end_pfn)) 4123 continue; 4124 4125 /* If this block is reserved, account for it */ 4126 if (block_migratetype == MIGRATE_RESERVE) { 4127 reserve--; 4128 continue; 4129 } 4130 4131 /* Suitable for reserving if this block is movable */ 4132 if (block_migratetype == MIGRATE_MOVABLE) { 4133 set_pageblock_migratetype(page, 4134 MIGRATE_RESERVE); 4135 move_freepages_block(zone, page, 4136 MIGRATE_RESERVE); 4137 reserve--; 4138 continue; 4139 } 4140 } else if (!old_reserve) { 4141 /* 4142 * At boot time we don't need to scan the whole zone 4143 * for turning off MIGRATE_RESERVE. 4144 */ 4145 break; 4146 } 4147 4148 /* 4149 * If the reserve is met and this is a previous reserved block, 4150 * take it back 4151 */ 4152 if (block_migratetype == MIGRATE_RESERVE) { 4153 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 4154 move_freepages_block(zone, page, MIGRATE_MOVABLE); 4155 } 4156 } 4157 } 4158 4159 /* 4160 * Initially all pages are reserved - free ones are freed 4161 * up by free_all_bootmem() once the early boot process is 4162 * done. Non-atomic initialization, single-pass. 4163 */ 4164 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, 4165 unsigned long start_pfn, enum memmap_context context) 4166 { 4167 struct page *page; 4168 unsigned long end_pfn = start_pfn + size; 4169 unsigned long pfn; 4170 struct zone *z; 4171 4172 if (highest_memmap_pfn < end_pfn - 1) 4173 highest_memmap_pfn = end_pfn - 1; 4174 4175 z = &NODE_DATA(nid)->node_zones[zone]; 4176 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 4177 /* 4178 * There can be holes in boot-time mem_map[]s 4179 * handed to this function. They do not 4180 * exist on hotplugged memory. 4181 */ 4182 if (context == MEMMAP_EARLY) { 4183 if (!early_pfn_valid(pfn)) 4184 continue; 4185 if (!early_pfn_in_nid(pfn, nid)) 4186 continue; 4187 } 4188 page = pfn_to_page(pfn); 4189 set_page_links(page, zone, nid, pfn); 4190 mminit_verify_page_links(page, zone, nid, pfn); 4191 init_page_count(page); 4192 page_mapcount_reset(page); 4193 page_cpupid_reset_last(page); 4194 SetPageReserved(page); 4195 /* 4196 * Mark the block movable so that blocks are reserved for 4197 * movable at startup. This will force kernel allocations 4198 * to reserve their blocks rather than leaking throughout 4199 * the address space during boot when many long-lived 4200 * kernel allocations are made. Later some blocks near 4201 * the start are marked MIGRATE_RESERVE by 4202 * setup_zone_migrate_reserve() 4203 * 4204 * bitmap is created for zone's valid pfn range. but memmap 4205 * can be created for invalid pages (for alignment) 4206 * check here not to call set_pageblock_migratetype() against 4207 * pfn out of zone. 4208 */ 4209 if ((z->zone_start_pfn <= pfn) 4210 && (pfn < zone_end_pfn(z)) 4211 && !(pfn & (pageblock_nr_pages - 1))) 4212 set_pageblock_migratetype(page, MIGRATE_MOVABLE); 4213 4214 INIT_LIST_HEAD(&page->lru); 4215 #ifdef WANT_PAGE_VIRTUAL 4216 /* The shift won't overflow because ZONE_NORMAL is below 4G. */ 4217 if (!is_highmem_idx(zone)) 4218 set_page_address(page, __va(pfn << PAGE_SHIFT)); 4219 #endif 4220 } 4221 } 4222 4223 static void __meminit zone_init_free_lists(struct zone *zone) 4224 { 4225 unsigned int order, t; 4226 for_each_migratetype_order(order, t) { 4227 INIT_LIST_HEAD(&zone->free_area[order].free_list[t]); 4228 zone->free_area[order].nr_free = 0; 4229 } 4230 } 4231 4232 #ifndef __HAVE_ARCH_MEMMAP_INIT 4233 #define memmap_init(size, nid, zone, start_pfn) \ 4234 memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY) 4235 #endif 4236 4237 static int zone_batchsize(struct zone *zone) 4238 { 4239 #ifdef CONFIG_MMU 4240 int batch; 4241 4242 /* 4243 * The per-cpu-pages pools are set to around 1000th of the 4244 * size of the zone. But no more than 1/2 of a meg. 4245 * 4246 * OK, so we don't know how big the cache is. So guess. 4247 */ 4248 batch = zone->managed_pages / 1024; 4249 if (batch * PAGE_SIZE > 512 * 1024) 4250 batch = (512 * 1024) / PAGE_SIZE; 4251 batch /= 4; /* We effectively *= 4 below */ 4252 if (batch < 1) 4253 batch = 1; 4254 4255 /* 4256 * Clamp the batch to a 2^n - 1 value. Having a power 4257 * of 2 value was found to be more likely to have 4258 * suboptimal cache aliasing properties in some cases. 4259 * 4260 * For example if 2 tasks are alternately allocating 4261 * batches of pages, one task can end up with a lot 4262 * of pages of one half of the possible page colors 4263 * and the other with pages of the other colors. 4264 */ 4265 batch = rounddown_pow_of_two(batch + batch/2) - 1; 4266 4267 return batch; 4268 4269 #else 4270 /* The deferral and batching of frees should be suppressed under NOMMU 4271 * conditions. 4272 * 4273 * The problem is that NOMMU needs to be able to allocate large chunks 4274 * of contiguous memory as there's no hardware page translation to 4275 * assemble apparent contiguous memory from discontiguous pages. 4276 * 4277 * Queueing large contiguous runs of pages for batching, however, 4278 * causes the pages to actually be freed in smaller chunks. As there 4279 * can be a significant delay between the individual batches being 4280 * recycled, this leads to the once large chunks of space being 4281 * fragmented and becoming unavailable for high-order allocations. 4282 */ 4283 return 0; 4284 #endif 4285 } 4286 4287 /* 4288 * pcp->high and pcp->batch values are related and dependent on one another: 4289 * ->batch must never be higher then ->high. 4290 * The following function updates them in a safe manner without read side 4291 * locking. 4292 * 4293 * Any new users of pcp->batch and pcp->high should ensure they can cope with 4294 * those fields changing asynchronously (acording the the above rule). 4295 * 4296 * mutex_is_locked(&pcp_batch_high_lock) required when calling this function 4297 * outside of boot time (or some other assurance that no concurrent updaters 4298 * exist). 4299 */ 4300 static void pageset_update(struct per_cpu_pages *pcp, unsigned long high, 4301 unsigned long batch) 4302 { 4303 /* start with a fail safe value for batch */ 4304 pcp->batch = 1; 4305 smp_wmb(); 4306 4307 /* Update high, then batch, in order */ 4308 pcp->high = high; 4309 smp_wmb(); 4310 4311 pcp->batch = batch; 4312 } 4313 4314 /* a companion to pageset_set_high() */ 4315 static void pageset_set_batch(struct per_cpu_pageset *p, unsigned long batch) 4316 { 4317 pageset_update(&p->pcp, 6 * batch, max(1UL, 1 * batch)); 4318 } 4319 4320 static void pageset_init(struct per_cpu_pageset *p) 4321 { 4322 struct per_cpu_pages *pcp; 4323 int migratetype; 4324 4325 memset(p, 0, sizeof(*p)); 4326 4327 pcp = &p->pcp; 4328 pcp->count = 0; 4329 for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++) 4330 INIT_LIST_HEAD(&pcp->lists[migratetype]); 4331 } 4332 4333 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch) 4334 { 4335 pageset_init(p); 4336 pageset_set_batch(p, batch); 4337 } 4338 4339 /* 4340 * pageset_set_high() sets the high water mark for hot per_cpu_pagelist 4341 * to the value high for the pageset p. 4342 */ 4343 static void pageset_set_high(struct per_cpu_pageset *p, 4344 unsigned long high) 4345 { 4346 unsigned long batch = max(1UL, high / 4); 4347 if ((high / 4) > (PAGE_SHIFT * 8)) 4348 batch = PAGE_SHIFT * 8; 4349 4350 pageset_update(&p->pcp, high, batch); 4351 } 4352 4353 static void pageset_set_high_and_batch(struct zone *zone, 4354 struct per_cpu_pageset *pcp) 4355 { 4356 if (percpu_pagelist_fraction) 4357 pageset_set_high(pcp, 4358 (zone->managed_pages / 4359 percpu_pagelist_fraction)); 4360 else 4361 pageset_set_batch(pcp, zone_batchsize(zone)); 4362 } 4363 4364 static void __meminit zone_pageset_init(struct zone *zone, int cpu) 4365 { 4366 struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu); 4367 4368 pageset_init(pcp); 4369 pageset_set_high_and_batch(zone, pcp); 4370 } 4371 4372 static void __meminit setup_zone_pageset(struct zone *zone) 4373 { 4374 int cpu; 4375 zone->pageset = alloc_percpu(struct per_cpu_pageset); 4376 for_each_possible_cpu(cpu) 4377 zone_pageset_init(zone, cpu); 4378 } 4379 4380 /* 4381 * Allocate per cpu pagesets and initialize them. 4382 * Before this call only boot pagesets were available. 4383 */ 4384 void __init setup_per_cpu_pageset(void) 4385 { 4386 struct zone *zone; 4387 4388 for_each_populated_zone(zone) 4389 setup_zone_pageset(zone); 4390 } 4391 4392 static noinline __init_refok 4393 int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) 4394 { 4395 int i; 4396 size_t alloc_size; 4397 4398 /* 4399 * The per-page waitqueue mechanism uses hashed waitqueues 4400 * per zone. 4401 */ 4402 zone->wait_table_hash_nr_entries = 4403 wait_table_hash_nr_entries(zone_size_pages); 4404 zone->wait_table_bits = 4405 wait_table_bits(zone->wait_table_hash_nr_entries); 4406 alloc_size = zone->wait_table_hash_nr_entries 4407 * sizeof(wait_queue_head_t); 4408 4409 if (!slab_is_available()) { 4410 zone->wait_table = (wait_queue_head_t *) 4411 memblock_virt_alloc_node_nopanic( 4412 alloc_size, zone->zone_pgdat->node_id); 4413 } else { 4414 /* 4415 * This case means that a zone whose size was 0 gets new memory 4416 * via memory hot-add. 4417 * But it may be the case that a new node was hot-added. In 4418 * this case vmalloc() will not be able to use this new node's 4419 * memory - this wait_table must be initialized to use this new 4420 * node itself as well. 4421 * To use this new node's memory, further consideration will be 4422 * necessary. 4423 */ 4424 zone->wait_table = vmalloc(alloc_size); 4425 } 4426 if (!zone->wait_table) 4427 return -ENOMEM; 4428 4429 for (i = 0; i < zone->wait_table_hash_nr_entries; ++i) 4430 init_waitqueue_head(zone->wait_table + i); 4431 4432 return 0; 4433 } 4434 4435 static __meminit void zone_pcp_init(struct zone *zone) 4436 { 4437 /* 4438 * per cpu subsystem is not up at this point. The following code 4439 * relies on the ability of the linker to provide the 4440 * offset of a (static) per cpu variable into the per cpu area. 4441 */ 4442 zone->pageset = &boot_pageset; 4443 4444 if (populated_zone(zone)) 4445 printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n", 4446 zone->name, zone->present_pages, 4447 zone_batchsize(zone)); 4448 } 4449 4450 int __meminit init_currently_empty_zone(struct zone *zone, 4451 unsigned long zone_start_pfn, 4452 unsigned long size, 4453 enum memmap_context context) 4454 { 4455 struct pglist_data *pgdat = zone->zone_pgdat; 4456 int ret; 4457 ret = zone_wait_table_init(zone, size); 4458 if (ret) 4459 return ret; 4460 pgdat->nr_zones = zone_idx(zone) + 1; 4461 4462 zone->zone_start_pfn = zone_start_pfn; 4463 4464 mminit_dprintk(MMINIT_TRACE, "memmap_init", 4465 "Initialising map node %d zone %lu pfns %lu -> %lu\n", 4466 pgdat->node_id, 4467 (unsigned long)zone_idx(zone), 4468 zone_start_pfn, (zone_start_pfn + size)); 4469 4470 zone_init_free_lists(zone); 4471 4472 return 0; 4473 } 4474 4475 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 4476 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID 4477 /* 4478 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on. 4479 */ 4480 int __meminit __early_pfn_to_nid(unsigned long pfn) 4481 { 4482 unsigned long start_pfn, end_pfn; 4483 int nid; 4484 /* 4485 * NOTE: The following SMP-unsafe globals are only used early in boot 4486 * when the kernel is running single-threaded. 4487 */ 4488 static unsigned long __meminitdata last_start_pfn, last_end_pfn; 4489 static int __meminitdata last_nid; 4490 4491 if (last_start_pfn <= pfn && pfn < last_end_pfn) 4492 return last_nid; 4493 4494 nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn); 4495 if (nid != -1) { 4496 last_start_pfn = start_pfn; 4497 last_end_pfn = end_pfn; 4498 last_nid = nid; 4499 } 4500 4501 return nid; 4502 } 4503 #endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */ 4504 4505 int __meminit early_pfn_to_nid(unsigned long pfn) 4506 { 4507 int nid; 4508 4509 nid = __early_pfn_to_nid(pfn); 4510 if (nid >= 0) 4511 return nid; 4512 /* just returns 0 */ 4513 return 0; 4514 } 4515 4516 #ifdef CONFIG_NODES_SPAN_OTHER_NODES 4517 bool __meminit early_pfn_in_nid(unsigned long pfn, int node) 4518 { 4519 int nid; 4520 4521 nid = __early_pfn_to_nid(pfn); 4522 if (nid >= 0 && nid != node) 4523 return false; 4524 return true; 4525 } 4526 #endif 4527 4528 /** 4529 * free_bootmem_with_active_regions - Call memblock_free_early_nid for each active range 4530 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed. 4531 * @max_low_pfn: The highest PFN that will be passed to memblock_free_early_nid 4532 * 4533 * If an architecture guarantees that all ranges registered contain no holes 4534 * and may be freed, this this function may be used instead of calling 4535 * memblock_free_early_nid() manually. 4536 */ 4537 void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn) 4538 { 4539 unsigned long start_pfn, end_pfn; 4540 int i, this_nid; 4541 4542 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) { 4543 start_pfn = min(start_pfn, max_low_pfn); 4544 end_pfn = min(end_pfn, max_low_pfn); 4545 4546 if (start_pfn < end_pfn) 4547 memblock_free_early_nid(PFN_PHYS(start_pfn), 4548 (end_pfn - start_pfn) << PAGE_SHIFT, 4549 this_nid); 4550 } 4551 } 4552 4553 /** 4554 * sparse_memory_present_with_active_regions - Call memory_present for each active range 4555 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used. 4556 * 4557 * If an architecture guarantees that all ranges registered contain no holes and may 4558 * be freed, this function may be used instead of calling memory_present() manually. 4559 */ 4560 void __init sparse_memory_present_with_active_regions(int nid) 4561 { 4562 unsigned long start_pfn, end_pfn; 4563 int i, this_nid; 4564 4565 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) 4566 memory_present(this_nid, start_pfn, end_pfn); 4567 } 4568 4569 /** 4570 * get_pfn_range_for_nid - Return the start and end page frames for a node 4571 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned. 4572 * @start_pfn: Passed by reference. On return, it will have the node start_pfn. 4573 * @end_pfn: Passed by reference. On return, it will have the node end_pfn. 4574 * 4575 * It returns the start and end page frame of a node based on information 4576 * provided by memblock_set_node(). If called for a node 4577 * with no available memory, a warning is printed and the start and end 4578 * PFNs will be 0. 4579 */ 4580 void __meminit get_pfn_range_for_nid(unsigned int nid, 4581 unsigned long *start_pfn, unsigned long *end_pfn) 4582 { 4583 unsigned long this_start_pfn, this_end_pfn; 4584 int i; 4585 4586 *start_pfn = -1UL; 4587 *end_pfn = 0; 4588 4589 for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) { 4590 *start_pfn = min(*start_pfn, this_start_pfn); 4591 *end_pfn = max(*end_pfn, this_end_pfn); 4592 } 4593 4594 if (*start_pfn == -1UL) 4595 *start_pfn = 0; 4596 } 4597 4598 /* 4599 * This finds a zone that can be used for ZONE_MOVABLE pages. The 4600 * assumption is made that zones within a node are ordered in monotonic 4601 * increasing memory addresses so that the "highest" populated zone is used 4602 */ 4603 static void __init find_usable_zone_for_movable(void) 4604 { 4605 int zone_index; 4606 for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) { 4607 if (zone_index == ZONE_MOVABLE) 4608 continue; 4609 4610 if (arch_zone_highest_possible_pfn[zone_index] > 4611 arch_zone_lowest_possible_pfn[zone_index]) 4612 break; 4613 } 4614 4615 VM_BUG_ON(zone_index == -1); 4616 movable_zone = zone_index; 4617 } 4618 4619 /* 4620 * The zone ranges provided by the architecture do not include ZONE_MOVABLE 4621 * because it is sized independent of architecture. Unlike the other zones, 4622 * the starting point for ZONE_MOVABLE is not fixed. It may be different 4623 * in each node depending on the size of each node and how evenly kernelcore 4624 * is distributed. This helper function adjusts the zone ranges 4625 * provided by the architecture for a given node by using the end of the 4626 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that 4627 * zones within a node are in order of monotonic increases memory addresses 4628 */ 4629 static void __meminit adjust_zone_range_for_zone_movable(int nid, 4630 unsigned long zone_type, 4631 unsigned long node_start_pfn, 4632 unsigned long node_end_pfn, 4633 unsigned long *zone_start_pfn, 4634 unsigned long *zone_end_pfn) 4635 { 4636 /* Only adjust if ZONE_MOVABLE is on this node */ 4637 if (zone_movable_pfn[nid]) { 4638 /* Size ZONE_MOVABLE */ 4639 if (zone_type == ZONE_MOVABLE) { 4640 *zone_start_pfn = zone_movable_pfn[nid]; 4641 *zone_end_pfn = min(node_end_pfn, 4642 arch_zone_highest_possible_pfn[movable_zone]); 4643 4644 /* Adjust for ZONE_MOVABLE starting within this range */ 4645 } else if (*zone_start_pfn < zone_movable_pfn[nid] && 4646 *zone_end_pfn > zone_movable_pfn[nid]) { 4647 *zone_end_pfn = zone_movable_pfn[nid]; 4648 4649 /* Check if this whole range is within ZONE_MOVABLE */ 4650 } else if (*zone_start_pfn >= zone_movable_pfn[nid]) 4651 *zone_start_pfn = *zone_end_pfn; 4652 } 4653 } 4654 4655 /* 4656 * Return the number of pages a zone spans in a node, including holes 4657 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node() 4658 */ 4659 static unsigned long __meminit zone_spanned_pages_in_node(int nid, 4660 unsigned long zone_type, 4661 unsigned long node_start_pfn, 4662 unsigned long node_end_pfn, 4663 unsigned long *ignored) 4664 { 4665 unsigned long zone_start_pfn, zone_end_pfn; 4666 4667 /* Get the start and end of the zone */ 4668 zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type]; 4669 zone_end_pfn = arch_zone_highest_possible_pfn[zone_type]; 4670 adjust_zone_range_for_zone_movable(nid, zone_type, 4671 node_start_pfn, node_end_pfn, 4672 &zone_start_pfn, &zone_end_pfn); 4673 4674 /* Check that this node has pages within the zone's required range */ 4675 if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn) 4676 return 0; 4677 4678 /* Move the zone boundaries inside the node if necessary */ 4679 zone_end_pfn = min(zone_end_pfn, node_end_pfn); 4680 zone_start_pfn = max(zone_start_pfn, node_start_pfn); 4681 4682 /* Return the spanned pages */ 4683 return zone_end_pfn - zone_start_pfn; 4684 } 4685 4686 /* 4687 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES, 4688 * then all holes in the requested range will be accounted for. 4689 */ 4690 unsigned long __meminit __absent_pages_in_range(int nid, 4691 unsigned long range_start_pfn, 4692 unsigned long range_end_pfn) 4693 { 4694 unsigned long nr_absent = range_end_pfn - range_start_pfn; 4695 unsigned long start_pfn, end_pfn; 4696 int i; 4697 4698 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { 4699 start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn); 4700 end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn); 4701 nr_absent -= end_pfn - start_pfn; 4702 } 4703 return nr_absent; 4704 } 4705 4706 /** 4707 * absent_pages_in_range - Return number of page frames in holes within a range 4708 * @start_pfn: The start PFN to start searching for holes 4709 * @end_pfn: The end PFN to stop searching for holes 4710 * 4711 * It returns the number of pages frames in memory holes within a range. 4712 */ 4713 unsigned long __init absent_pages_in_range(unsigned long start_pfn, 4714 unsigned long end_pfn) 4715 { 4716 return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn); 4717 } 4718 4719 /* Return the number of page frames in holes in a zone on a node */ 4720 static unsigned long __meminit zone_absent_pages_in_node(int nid, 4721 unsigned long zone_type, 4722 unsigned long node_start_pfn, 4723 unsigned long node_end_pfn, 4724 unsigned long *ignored) 4725 { 4726 unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type]; 4727 unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type]; 4728 unsigned long zone_start_pfn, zone_end_pfn; 4729 4730 zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high); 4731 zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high); 4732 4733 adjust_zone_range_for_zone_movable(nid, zone_type, 4734 node_start_pfn, node_end_pfn, 4735 &zone_start_pfn, &zone_end_pfn); 4736 return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); 4737 } 4738 4739 #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 4740 static inline unsigned long __meminit zone_spanned_pages_in_node(int nid, 4741 unsigned long zone_type, 4742 unsigned long node_start_pfn, 4743 unsigned long node_end_pfn, 4744 unsigned long *zones_size) 4745 { 4746 return zones_size[zone_type]; 4747 } 4748 4749 static inline unsigned long __meminit zone_absent_pages_in_node(int nid, 4750 unsigned long zone_type, 4751 unsigned long node_start_pfn, 4752 unsigned long node_end_pfn, 4753 unsigned long *zholes_size) 4754 { 4755 if (!zholes_size) 4756 return 0; 4757 4758 return zholes_size[zone_type]; 4759 } 4760 4761 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 4762 4763 static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, 4764 unsigned long node_start_pfn, 4765 unsigned long node_end_pfn, 4766 unsigned long *zones_size, 4767 unsigned long *zholes_size) 4768 { 4769 unsigned long realtotalpages, totalpages = 0; 4770 enum zone_type i; 4771 4772 for (i = 0; i < MAX_NR_ZONES; i++) 4773 totalpages += zone_spanned_pages_in_node(pgdat->node_id, i, 4774 node_start_pfn, 4775 node_end_pfn, 4776 zones_size); 4777 pgdat->node_spanned_pages = totalpages; 4778 4779 realtotalpages = totalpages; 4780 for (i = 0; i < MAX_NR_ZONES; i++) 4781 realtotalpages -= 4782 zone_absent_pages_in_node(pgdat->node_id, i, 4783 node_start_pfn, node_end_pfn, 4784 zholes_size); 4785 pgdat->node_present_pages = realtotalpages; 4786 printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, 4787 realtotalpages); 4788 } 4789 4790 #ifndef CONFIG_SPARSEMEM 4791 /* 4792 * Calculate the size of the zone->blockflags rounded to an unsigned long 4793 * Start by making sure zonesize is a multiple of pageblock_order by rounding 4794 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally 4795 * round what is now in bits to nearest long in bits, then return it in 4796 * bytes. 4797 */ 4798 static unsigned long __init usemap_size(unsigned long zone_start_pfn, unsigned long zonesize) 4799 { 4800 unsigned long usemapsize; 4801 4802 zonesize += zone_start_pfn & (pageblock_nr_pages-1); 4803 usemapsize = roundup(zonesize, pageblock_nr_pages); 4804 usemapsize = usemapsize >> pageblock_order; 4805 usemapsize *= NR_PAGEBLOCK_BITS; 4806 usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); 4807 4808 return usemapsize / 8; 4809 } 4810 4811 static void __init setup_usemap(struct pglist_data *pgdat, 4812 struct zone *zone, 4813 unsigned long zone_start_pfn, 4814 unsigned long zonesize) 4815 { 4816 unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize); 4817 zone->pageblock_flags = NULL; 4818 if (usemapsize) 4819 zone->pageblock_flags = 4820 memblock_virt_alloc_node_nopanic(usemapsize, 4821 pgdat->node_id); 4822 } 4823 #else 4824 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone, 4825 unsigned long zone_start_pfn, unsigned long zonesize) {} 4826 #endif /* CONFIG_SPARSEMEM */ 4827 4828 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 4829 4830 /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ 4831 void __paginginit set_pageblock_order(void) 4832 { 4833 unsigned int order; 4834 4835 /* Check that pageblock_nr_pages has not already been setup */ 4836 if (pageblock_order) 4837 return; 4838 4839 if (HPAGE_SHIFT > PAGE_SHIFT) 4840 order = HUGETLB_PAGE_ORDER; 4841 else 4842 order = MAX_ORDER - 1; 4843 4844 /* 4845 * Assume the largest contiguous order of interest is a huge page. 4846 * This value may be variable depending on boot parameters on IA64 and 4847 * powerpc. 4848 */ 4849 pageblock_order = order; 4850 } 4851 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 4852 4853 /* 4854 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order() 4855 * is unused as pageblock_order is set at compile-time. See 4856 * include/linux/pageblock-flags.h for the values of pageblock_order based on 4857 * the kernel config 4858 */ 4859 void __paginginit set_pageblock_order(void) 4860 { 4861 } 4862 4863 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 4864 4865 static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages, 4866 unsigned long present_pages) 4867 { 4868 unsigned long pages = spanned_pages; 4869 4870 /* 4871 * Provide a more accurate estimation if there are holes within 4872 * the zone and SPARSEMEM is in use. If there are holes within the 4873 * zone, each populated memory region may cost us one or two extra 4874 * memmap pages due to alignment because memmap pages for each 4875 * populated regions may not naturally algined on page boundary. 4876 * So the (present_pages >> 4) heuristic is a tradeoff for that. 4877 */ 4878 if (spanned_pages > present_pages + (present_pages >> 4) && 4879 IS_ENABLED(CONFIG_SPARSEMEM)) 4880 pages = present_pages; 4881 4882 return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT; 4883 } 4884 4885 /* 4886 * Set up the zone data structures: 4887 * - mark all pages reserved 4888 * - mark all memory queues empty 4889 * - clear the memory bitmaps 4890 * 4891 * NOTE: pgdat should get zeroed by caller. 4892 */ 4893 static void __paginginit free_area_init_core(struct pglist_data *pgdat, 4894 unsigned long node_start_pfn, unsigned long node_end_pfn, 4895 unsigned long *zones_size, unsigned long *zholes_size) 4896 { 4897 enum zone_type j; 4898 int nid = pgdat->node_id; 4899 unsigned long zone_start_pfn = pgdat->node_start_pfn; 4900 int ret; 4901 4902 pgdat_resize_init(pgdat); 4903 #ifdef CONFIG_NUMA_BALANCING 4904 spin_lock_init(&pgdat->numabalancing_migrate_lock); 4905 pgdat->numabalancing_migrate_nr_pages = 0; 4906 pgdat->numabalancing_migrate_next_window = jiffies; 4907 #endif 4908 init_waitqueue_head(&pgdat->kswapd_wait); 4909 init_waitqueue_head(&pgdat->pfmemalloc_wait); 4910 pgdat_page_ext_init(pgdat); 4911 4912 for (j = 0; j < MAX_NR_ZONES; j++) { 4913 struct zone *zone = pgdat->node_zones + j; 4914 unsigned long size, realsize, freesize, memmap_pages; 4915 4916 size = zone_spanned_pages_in_node(nid, j, node_start_pfn, 4917 node_end_pfn, zones_size); 4918 realsize = freesize = size - zone_absent_pages_in_node(nid, j, 4919 node_start_pfn, 4920 node_end_pfn, 4921 zholes_size); 4922 4923 /* 4924 * Adjust freesize so that it accounts for how much memory 4925 * is used by this zone for memmap. This affects the watermark 4926 * and per-cpu initialisations 4927 */ 4928 memmap_pages = calc_memmap_size(size, realsize); 4929 if (!is_highmem_idx(j)) { 4930 if (freesize >= memmap_pages) { 4931 freesize -= memmap_pages; 4932 if (memmap_pages) 4933 printk(KERN_DEBUG 4934 " %s zone: %lu pages used for memmap\n", 4935 zone_names[j], memmap_pages); 4936 } else 4937 printk(KERN_WARNING 4938 " %s zone: %lu pages exceeds freesize %lu\n", 4939 zone_names[j], memmap_pages, freesize); 4940 } 4941 4942 /* Account for reserved pages */ 4943 if (j == 0 && freesize > dma_reserve) { 4944 freesize -= dma_reserve; 4945 printk(KERN_DEBUG " %s zone: %lu pages reserved\n", 4946 zone_names[0], dma_reserve); 4947 } 4948 4949 if (!is_highmem_idx(j)) 4950 nr_kernel_pages += freesize; 4951 /* Charge for highmem memmap if there are enough kernel pages */ 4952 else if (nr_kernel_pages > memmap_pages * 2) 4953 nr_kernel_pages -= memmap_pages; 4954 nr_all_pages += freesize; 4955 4956 zone->spanned_pages = size; 4957 zone->present_pages = realsize; 4958 /* 4959 * Set an approximate value for lowmem here, it will be adjusted 4960 * when the bootmem allocator frees pages into the buddy system. 4961 * And all highmem pages will be managed by the buddy system. 4962 */ 4963 zone->managed_pages = is_highmem_idx(j) ? realsize : freesize; 4964 #ifdef CONFIG_NUMA 4965 zone->node = nid; 4966 zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio) 4967 / 100; 4968 zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100; 4969 #endif 4970 zone->name = zone_names[j]; 4971 spin_lock_init(&zone->lock); 4972 spin_lock_init(&zone->lru_lock); 4973 zone_seqlock_init(zone); 4974 zone->zone_pgdat = pgdat; 4975 zone_pcp_init(zone); 4976 4977 /* For bootup, initialized properly in watermark setup */ 4978 mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages); 4979 4980 lruvec_init(&zone->lruvec); 4981 if (!size) 4982 continue; 4983 4984 set_pageblock_order(); 4985 setup_usemap(pgdat, zone, zone_start_pfn, size); 4986 ret = init_currently_empty_zone(zone, zone_start_pfn, 4987 size, MEMMAP_EARLY); 4988 BUG_ON(ret); 4989 memmap_init(size, nid, j, zone_start_pfn); 4990 zone_start_pfn += size; 4991 } 4992 } 4993 4994 static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat) 4995 { 4996 /* Skip empty nodes */ 4997 if (!pgdat->node_spanned_pages) 4998 return; 4999 5000 #ifdef CONFIG_FLAT_NODE_MEM_MAP 5001 /* ia64 gets its own node_mem_map, before this, without bootmem */ 5002 if (!pgdat->node_mem_map) { 5003 unsigned long size, start, end; 5004 struct page *map; 5005 5006 /* 5007 * The zone's endpoints aren't required to be MAX_ORDER 5008 * aligned but the node_mem_map endpoints must be in order 5009 * for the buddy allocator to function correctly. 5010 */ 5011 start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1); 5012 end = pgdat_end_pfn(pgdat); 5013 end = ALIGN(end, MAX_ORDER_NR_PAGES); 5014 size = (end - start) * sizeof(struct page); 5015 map = alloc_remap(pgdat->node_id, size); 5016 if (!map) 5017 map = memblock_virt_alloc_node_nopanic(size, 5018 pgdat->node_id); 5019 pgdat->node_mem_map = map + (pgdat->node_start_pfn - start); 5020 } 5021 #ifndef CONFIG_NEED_MULTIPLE_NODES 5022 /* 5023 * With no DISCONTIG, the global mem_map is just set as node 0's 5024 */ 5025 if (pgdat == NODE_DATA(0)) { 5026 mem_map = NODE_DATA(0)->node_mem_map; 5027 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 5028 if (page_to_pfn(mem_map) != pgdat->node_start_pfn) 5029 mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET); 5030 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 5031 } 5032 #endif 5033 #endif /* CONFIG_FLAT_NODE_MEM_MAP */ 5034 } 5035 5036 void __paginginit free_area_init_node(int nid, unsigned long *zones_size, 5037 unsigned long node_start_pfn, unsigned long *zholes_size) 5038 { 5039 pg_data_t *pgdat = NODE_DATA(nid); 5040 unsigned long start_pfn = 0; 5041 unsigned long end_pfn = 0; 5042 5043 /* pg_data_t should be reset to zero when it's allocated */ 5044 WARN_ON(pgdat->nr_zones || pgdat->classzone_idx); 5045 5046 pgdat->node_id = nid; 5047 pgdat->node_start_pfn = node_start_pfn; 5048 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 5049 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn); 5050 printk(KERN_INFO "Initmem setup node %d [mem %#010Lx-%#010Lx]\n", nid, 5051 (u64) start_pfn << PAGE_SHIFT, (u64) (end_pfn << PAGE_SHIFT) - 1); 5052 #endif 5053 calculate_node_totalpages(pgdat, start_pfn, end_pfn, 5054 zones_size, zholes_size); 5055 5056 alloc_node_mem_map(pgdat); 5057 #ifdef CONFIG_FLAT_NODE_MEM_MAP 5058 printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n", 5059 nid, (unsigned long)pgdat, 5060 (unsigned long)pgdat->node_mem_map); 5061 #endif 5062 5063 free_area_init_core(pgdat, start_pfn, end_pfn, 5064 zones_size, zholes_size); 5065 } 5066 5067 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 5068 5069 #if MAX_NUMNODES > 1 5070 /* 5071 * Figure out the number of possible node ids. 5072 */ 5073 void __init setup_nr_node_ids(void) 5074 { 5075 unsigned int node; 5076 unsigned int highest = 0; 5077 5078 for_each_node_mask(node, node_possible_map) 5079 highest = node; 5080 nr_node_ids = highest + 1; 5081 } 5082 #endif 5083 5084 /** 5085 * node_map_pfn_alignment - determine the maximum internode alignment 5086 * 5087 * This function should be called after node map is populated and sorted. 5088 * It calculates the maximum power of two alignment which can distinguish 5089 * all the nodes. 5090 * 5091 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value 5092 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)). If the 5093 * nodes are shifted by 256MiB, 256MiB. Note that if only the last node is 5094 * shifted, 1GiB is enough and this function will indicate so. 5095 * 5096 * This is used to test whether pfn -> nid mapping of the chosen memory 5097 * model has fine enough granularity to avoid incorrect mapping for the 5098 * populated node map. 5099 * 5100 * Returns the determined alignment in pfn's. 0 if there is no alignment 5101 * requirement (single node). 5102 */ 5103 unsigned long __init node_map_pfn_alignment(void) 5104 { 5105 unsigned long accl_mask = 0, last_end = 0; 5106 unsigned long start, end, mask; 5107 int last_nid = -1; 5108 int i, nid; 5109 5110 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) { 5111 if (!start || last_nid < 0 || last_nid == nid) { 5112 last_nid = nid; 5113 last_end = end; 5114 continue; 5115 } 5116 5117 /* 5118 * Start with a mask granular enough to pin-point to the 5119 * start pfn and tick off bits one-by-one until it becomes 5120 * too coarse to separate the current node from the last. 5121 */ 5122 mask = ~((1 << __ffs(start)) - 1); 5123 while (mask && last_end <= (start & (mask << 1))) 5124 mask <<= 1; 5125 5126 /* accumulate all internode masks */ 5127 accl_mask |= mask; 5128 } 5129 5130 /* convert mask to number of pages */ 5131 return ~accl_mask + 1; 5132 } 5133 5134 /* Find the lowest pfn for a node */ 5135 static unsigned long __init find_min_pfn_for_node(int nid) 5136 { 5137 unsigned long min_pfn = ULONG_MAX; 5138 unsigned long start_pfn; 5139 int i; 5140 5141 for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL) 5142 min_pfn = min(min_pfn, start_pfn); 5143 5144 if (min_pfn == ULONG_MAX) { 5145 printk(KERN_WARNING 5146 "Could not find start_pfn for node %d\n", nid); 5147 return 0; 5148 } 5149 5150 return min_pfn; 5151 } 5152 5153 /** 5154 * find_min_pfn_with_active_regions - Find the minimum PFN registered 5155 * 5156 * It returns the minimum PFN based on information provided via 5157 * memblock_set_node(). 5158 */ 5159 unsigned long __init find_min_pfn_with_active_regions(void) 5160 { 5161 return find_min_pfn_for_node(MAX_NUMNODES); 5162 } 5163 5164 /* 5165 * early_calculate_totalpages() 5166 * Sum pages in active regions for movable zone. 5167 * Populate N_MEMORY for calculating usable_nodes. 5168 */ 5169 static unsigned long __init early_calculate_totalpages(void) 5170 { 5171 unsigned long totalpages = 0; 5172 unsigned long start_pfn, end_pfn; 5173 int i, nid; 5174 5175 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { 5176 unsigned long pages = end_pfn - start_pfn; 5177 5178 totalpages += pages; 5179 if (pages) 5180 node_set_state(nid, N_MEMORY); 5181 } 5182 return totalpages; 5183 } 5184 5185 /* 5186 * Find the PFN the Movable zone begins in each node. Kernel memory 5187 * is spread evenly between nodes as long as the nodes have enough 5188 * memory. When they don't, some nodes will have more kernelcore than 5189 * others 5190 */ 5191 static void __init find_zone_movable_pfns_for_nodes(void) 5192 { 5193 int i, nid; 5194 unsigned long usable_startpfn; 5195 unsigned long kernelcore_node, kernelcore_remaining; 5196 /* save the state before borrow the nodemask */ 5197 nodemask_t saved_node_state = node_states[N_MEMORY]; 5198 unsigned long totalpages = early_calculate_totalpages(); 5199 int usable_nodes = nodes_weight(node_states[N_MEMORY]); 5200 struct memblock_region *r; 5201 5202 /* Need to find movable_zone earlier when movable_node is specified. */ 5203 find_usable_zone_for_movable(); 5204 5205 /* 5206 * If movable_node is specified, ignore kernelcore and movablecore 5207 * options. 5208 */ 5209 if (movable_node_is_enabled()) { 5210 for_each_memblock(memory, r) { 5211 if (!memblock_is_hotpluggable(r)) 5212 continue; 5213 5214 nid = r->nid; 5215 5216 usable_startpfn = PFN_DOWN(r->base); 5217 zone_movable_pfn[nid] = zone_movable_pfn[nid] ? 5218 min(usable_startpfn, zone_movable_pfn[nid]) : 5219 usable_startpfn; 5220 } 5221 5222 goto out2; 5223 } 5224 5225 /* 5226 * If movablecore=nn[KMG] was specified, calculate what size of 5227 * kernelcore that corresponds so that memory usable for 5228 * any allocation type is evenly spread. If both kernelcore 5229 * and movablecore are specified, then the value of kernelcore 5230 * will be used for required_kernelcore if it's greater than 5231 * what movablecore would have allowed. 5232 */ 5233 if (required_movablecore) { 5234 unsigned long corepages; 5235 5236 /* 5237 * Round-up so that ZONE_MOVABLE is at least as large as what 5238 * was requested by the user 5239 */ 5240 required_movablecore = 5241 roundup(required_movablecore, MAX_ORDER_NR_PAGES); 5242 corepages = totalpages - required_movablecore; 5243 5244 required_kernelcore = max(required_kernelcore, corepages); 5245 } 5246 5247 /* If kernelcore was not specified, there is no ZONE_MOVABLE */ 5248 if (!required_kernelcore) 5249 goto out; 5250 5251 /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ 5252 usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; 5253 5254 restart: 5255 /* Spread kernelcore memory as evenly as possible throughout nodes */ 5256 kernelcore_node = required_kernelcore / usable_nodes; 5257 for_each_node_state(nid, N_MEMORY) { 5258 unsigned long start_pfn, end_pfn; 5259 5260 /* 5261 * Recalculate kernelcore_node if the division per node 5262 * now exceeds what is necessary to satisfy the requested 5263 * amount of memory for the kernel 5264 */ 5265 if (required_kernelcore < kernelcore_node) 5266 kernelcore_node = required_kernelcore / usable_nodes; 5267 5268 /* 5269 * As the map is walked, we track how much memory is usable 5270 * by the kernel using kernelcore_remaining. When it is 5271 * 0, the rest of the node is usable by ZONE_MOVABLE 5272 */ 5273 kernelcore_remaining = kernelcore_node; 5274 5275 /* Go through each range of PFNs within this node */ 5276 for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) { 5277 unsigned long size_pages; 5278 5279 start_pfn = max(start_pfn, zone_movable_pfn[nid]); 5280 if (start_pfn >= end_pfn) 5281 continue; 5282 5283 /* Account for what is only usable for kernelcore */ 5284 if (start_pfn < usable_startpfn) { 5285 unsigned long kernel_pages; 5286 kernel_pages = min(end_pfn, usable_startpfn) 5287 - start_pfn; 5288 5289 kernelcore_remaining -= min(kernel_pages, 5290 kernelcore_remaining); 5291 required_kernelcore -= min(kernel_pages, 5292 required_kernelcore); 5293 5294 /* Continue if range is now fully accounted */ 5295 if (end_pfn <= usable_startpfn) { 5296 5297 /* 5298 * Push zone_movable_pfn to the end so 5299 * that if we have to rebalance 5300 * kernelcore across nodes, we will 5301 * not double account here 5302 */ 5303 zone_movable_pfn[nid] = end_pfn; 5304 continue; 5305 } 5306 start_pfn = usable_startpfn; 5307 } 5308 5309 /* 5310 * The usable PFN range for ZONE_MOVABLE is from 5311 * start_pfn->end_pfn. Calculate size_pages as the 5312 * number of pages used as kernelcore 5313 */ 5314 size_pages = end_pfn - start_pfn; 5315 if (size_pages > kernelcore_remaining) 5316 size_pages = kernelcore_remaining; 5317 zone_movable_pfn[nid] = start_pfn + size_pages; 5318 5319 /* 5320 * Some kernelcore has been met, update counts and 5321 * break if the kernelcore for this node has been 5322 * satisfied 5323 */ 5324 required_kernelcore -= min(required_kernelcore, 5325 size_pages); 5326 kernelcore_remaining -= size_pages; 5327 if (!kernelcore_remaining) 5328 break; 5329 } 5330 } 5331 5332 /* 5333 * If there is still required_kernelcore, we do another pass with one 5334 * less node in the count. This will push zone_movable_pfn[nid] further 5335 * along on the nodes that still have memory until kernelcore is 5336 * satisfied 5337 */ 5338 usable_nodes--; 5339 if (usable_nodes && required_kernelcore > usable_nodes) 5340 goto restart; 5341 5342 out2: 5343 /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ 5344 for (nid = 0; nid < MAX_NUMNODES; nid++) 5345 zone_movable_pfn[nid] = 5346 roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); 5347 5348 out: 5349 /* restore the node_state */ 5350 node_states[N_MEMORY] = saved_node_state; 5351 } 5352 5353 /* Any regular or high memory on that node ? */ 5354 static void check_for_memory(pg_data_t *pgdat, int nid) 5355 { 5356 enum zone_type zone_type; 5357 5358 if (N_MEMORY == N_NORMAL_MEMORY) 5359 return; 5360 5361 for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) { 5362 struct zone *zone = &pgdat->node_zones[zone_type]; 5363 if (populated_zone(zone)) { 5364 node_set_state(nid, N_HIGH_MEMORY); 5365 if (N_NORMAL_MEMORY != N_HIGH_MEMORY && 5366 zone_type <= ZONE_NORMAL) 5367 node_set_state(nid, N_NORMAL_MEMORY); 5368 break; 5369 } 5370 } 5371 } 5372 5373 /** 5374 * free_area_init_nodes - Initialise all pg_data_t and zone data 5375 * @max_zone_pfn: an array of max PFNs for each zone 5376 * 5377 * This will call free_area_init_node() for each active node in the system. 5378 * Using the page ranges provided by memblock_set_node(), the size of each 5379 * zone in each node and their holes is calculated. If the maximum PFN 5380 * between two adjacent zones match, it is assumed that the zone is empty. 5381 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed 5382 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone 5383 * starts where the previous one ended. For example, ZONE_DMA32 starts 5384 * at arch_max_dma_pfn. 5385 */ 5386 void __init free_area_init_nodes(unsigned long *max_zone_pfn) 5387 { 5388 unsigned long start_pfn, end_pfn; 5389 int i, nid; 5390 5391 /* Record where the zone boundaries are */ 5392 memset(arch_zone_lowest_possible_pfn, 0, 5393 sizeof(arch_zone_lowest_possible_pfn)); 5394 memset(arch_zone_highest_possible_pfn, 0, 5395 sizeof(arch_zone_highest_possible_pfn)); 5396 arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions(); 5397 arch_zone_highest_possible_pfn[0] = max_zone_pfn[0]; 5398 for (i = 1; i < MAX_NR_ZONES; i++) { 5399 if (i == ZONE_MOVABLE) 5400 continue; 5401 arch_zone_lowest_possible_pfn[i] = 5402 arch_zone_highest_possible_pfn[i-1]; 5403 arch_zone_highest_possible_pfn[i] = 5404 max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]); 5405 } 5406 arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0; 5407 arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0; 5408 5409 /* Find the PFNs that ZONE_MOVABLE begins at in each node */ 5410 memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn)); 5411 find_zone_movable_pfns_for_nodes(); 5412 5413 /* Print out the zone ranges */ 5414 pr_info("Zone ranges:\n"); 5415 for (i = 0; i < MAX_NR_ZONES; i++) { 5416 if (i == ZONE_MOVABLE) 5417 continue; 5418 pr_info(" %-8s ", zone_names[i]); 5419 if (arch_zone_lowest_possible_pfn[i] == 5420 arch_zone_highest_possible_pfn[i]) 5421 pr_cont("empty\n"); 5422 else 5423 pr_cont("[mem %0#10lx-%0#10lx]\n", 5424 arch_zone_lowest_possible_pfn[i] << PAGE_SHIFT, 5425 (arch_zone_highest_possible_pfn[i] 5426 << PAGE_SHIFT) - 1); 5427 } 5428 5429 /* Print out the PFNs ZONE_MOVABLE begins at in each node */ 5430 pr_info("Movable zone start for each node\n"); 5431 for (i = 0; i < MAX_NUMNODES; i++) { 5432 if (zone_movable_pfn[i]) 5433 pr_info(" Node %d: %#010lx\n", i, 5434 zone_movable_pfn[i] << PAGE_SHIFT); 5435 } 5436 5437 /* Print out the early node map */ 5438 pr_info("Early memory node ranges\n"); 5439 for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) 5440 pr_info(" node %3d: [mem %#010lx-%#010lx]\n", nid, 5441 start_pfn << PAGE_SHIFT, (end_pfn << PAGE_SHIFT) - 1); 5442 5443 /* Initialise every node */ 5444 mminit_verify_pageflags_layout(); 5445 setup_nr_node_ids(); 5446 for_each_online_node(nid) { 5447 pg_data_t *pgdat = NODE_DATA(nid); 5448 free_area_init_node(nid, NULL, 5449 find_min_pfn_for_node(nid), NULL); 5450 5451 /* Any memory on that node */ 5452 if (pgdat->node_present_pages) 5453 node_set_state(nid, N_MEMORY); 5454 check_for_memory(pgdat, nid); 5455 } 5456 } 5457 5458 static int __init cmdline_parse_core(char *p, unsigned long *core) 5459 { 5460 unsigned long long coremem; 5461 if (!p) 5462 return -EINVAL; 5463 5464 coremem = memparse(p, &p); 5465 *core = coremem >> PAGE_SHIFT; 5466 5467 /* Paranoid check that UL is enough for the coremem value */ 5468 WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX); 5469 5470 return 0; 5471 } 5472 5473 /* 5474 * kernelcore=size sets the amount of memory for use for allocations that 5475 * cannot be reclaimed or migrated. 5476 */ 5477 static int __init cmdline_parse_kernelcore(char *p) 5478 { 5479 return cmdline_parse_core(p, &required_kernelcore); 5480 } 5481 5482 /* 5483 * movablecore=size sets the amount of memory for use for allocations that 5484 * can be reclaimed or migrated. 5485 */ 5486 static int __init cmdline_parse_movablecore(char *p) 5487 { 5488 return cmdline_parse_core(p, &required_movablecore); 5489 } 5490 5491 early_param("kernelcore", cmdline_parse_kernelcore); 5492 early_param("movablecore", cmdline_parse_movablecore); 5493 5494 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ 5495 5496 void adjust_managed_page_count(struct page *page, long count) 5497 { 5498 spin_lock(&managed_page_count_lock); 5499 page_zone(page)->managed_pages += count; 5500 totalram_pages += count; 5501 #ifdef CONFIG_HIGHMEM 5502 if (PageHighMem(page)) 5503 totalhigh_pages += count; 5504 #endif 5505 spin_unlock(&managed_page_count_lock); 5506 } 5507 EXPORT_SYMBOL(adjust_managed_page_count); 5508 5509 unsigned long free_reserved_area(void *start, void *end, int poison, char *s) 5510 { 5511 void *pos; 5512 unsigned long pages = 0; 5513 5514 start = (void *)PAGE_ALIGN((unsigned long)start); 5515 end = (void *)((unsigned long)end & PAGE_MASK); 5516 for (pos = start; pos < end; pos += PAGE_SIZE, pages++) { 5517 if ((unsigned int)poison <= 0xFF) 5518 memset(pos, poison, PAGE_SIZE); 5519 free_reserved_page(virt_to_page(pos)); 5520 } 5521 5522 if (pages && s) 5523 pr_info("Freeing %s memory: %ldK (%p - %p)\n", 5524 s, pages << (PAGE_SHIFT - 10), start, end); 5525 5526 return pages; 5527 } 5528 EXPORT_SYMBOL(free_reserved_area); 5529 5530 #ifdef CONFIG_HIGHMEM 5531 void free_highmem_page(struct page *page) 5532 { 5533 __free_reserved_page(page); 5534 totalram_pages++; 5535 page_zone(page)->managed_pages++; 5536 totalhigh_pages++; 5537 } 5538 #endif 5539 5540 5541 void __init mem_init_print_info(const char *str) 5542 { 5543 unsigned long physpages, codesize, datasize, rosize, bss_size; 5544 unsigned long init_code_size, init_data_size; 5545 5546 physpages = get_num_physpages(); 5547 codesize = _etext - _stext; 5548 datasize = _edata - _sdata; 5549 rosize = __end_rodata - __start_rodata; 5550 bss_size = __bss_stop - __bss_start; 5551 init_data_size = __init_end - __init_begin; 5552 init_code_size = _einittext - _sinittext; 5553 5554 /* 5555 * Detect special cases and adjust section sizes accordingly: 5556 * 1) .init.* may be embedded into .data sections 5557 * 2) .init.text.* may be out of [__init_begin, __init_end], 5558 * please refer to arch/tile/kernel/vmlinux.lds.S. 5559 * 3) .rodata.* may be embedded into .text or .data sections. 5560 */ 5561 #define adj_init_size(start, end, size, pos, adj) \ 5562 do { \ 5563 if (start <= pos && pos < end && size > adj) \ 5564 size -= adj; \ 5565 } while (0) 5566 5567 adj_init_size(__init_begin, __init_end, init_data_size, 5568 _sinittext, init_code_size); 5569 adj_init_size(_stext, _etext, codesize, _sinittext, init_code_size); 5570 adj_init_size(_sdata, _edata, datasize, __init_begin, init_data_size); 5571 adj_init_size(_stext, _etext, codesize, __start_rodata, rosize); 5572 adj_init_size(_sdata, _edata, datasize, __start_rodata, rosize); 5573 5574 #undef adj_init_size 5575 5576 pr_info("Memory: %luK/%luK available " 5577 "(%luK kernel code, %luK rwdata, %luK rodata, " 5578 "%luK init, %luK bss, %luK reserved, %luK cma-reserved" 5579 #ifdef CONFIG_HIGHMEM 5580 ", %luK highmem" 5581 #endif 5582 "%s%s)\n", 5583 nr_free_pages() << (PAGE_SHIFT-10), physpages << (PAGE_SHIFT-10), 5584 codesize >> 10, datasize >> 10, rosize >> 10, 5585 (init_data_size + init_code_size) >> 10, bss_size >> 10, 5586 (physpages - totalram_pages - totalcma_pages) << (PAGE_SHIFT-10), 5587 totalcma_pages << (PAGE_SHIFT-10), 5588 #ifdef CONFIG_HIGHMEM 5589 totalhigh_pages << (PAGE_SHIFT-10), 5590 #endif 5591 str ? ", " : "", str ? str : ""); 5592 } 5593 5594 /** 5595 * set_dma_reserve - set the specified number of pages reserved in the first zone 5596 * @new_dma_reserve: The number of pages to mark reserved 5597 * 5598 * The per-cpu batchsize and zone watermarks are determined by present_pages. 5599 * In the DMA zone, a significant percentage may be consumed by kernel image 5600 * and other unfreeable allocations which can skew the watermarks badly. This 5601 * function may optionally be used to account for unfreeable pages in the 5602 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and 5603 * smaller per-cpu batchsize. 5604 */ 5605 void __init set_dma_reserve(unsigned long new_dma_reserve) 5606 { 5607 dma_reserve = new_dma_reserve; 5608 } 5609 5610 void __init free_area_init(unsigned long *zones_size) 5611 { 5612 free_area_init_node(0, zones_size, 5613 __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); 5614 } 5615 5616 static int page_alloc_cpu_notify(struct notifier_block *self, 5617 unsigned long action, void *hcpu) 5618 { 5619 int cpu = (unsigned long)hcpu; 5620 5621 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { 5622 lru_add_drain_cpu(cpu); 5623 drain_pages(cpu); 5624 5625 /* 5626 * Spill the event counters of the dead processor 5627 * into the current processors event counters. 5628 * This artificially elevates the count of the current 5629 * processor. 5630 */ 5631 vm_events_fold_cpu(cpu); 5632 5633 /* 5634 * Zero the differential counters of the dead processor 5635 * so that the vm statistics are consistent. 5636 * 5637 * This is only okay since the processor is dead and cannot 5638 * race with what we are doing. 5639 */ 5640 cpu_vm_stats_fold(cpu); 5641 } 5642 return NOTIFY_OK; 5643 } 5644 5645 void __init page_alloc_init(void) 5646 { 5647 hotcpu_notifier(page_alloc_cpu_notify, 0); 5648 } 5649 5650 /* 5651 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio 5652 * or min_free_kbytes changes. 5653 */ 5654 static void calculate_totalreserve_pages(void) 5655 { 5656 struct pglist_data *pgdat; 5657 unsigned long reserve_pages = 0; 5658 enum zone_type i, j; 5659 5660 for_each_online_pgdat(pgdat) { 5661 for (i = 0; i < MAX_NR_ZONES; i++) { 5662 struct zone *zone = pgdat->node_zones + i; 5663 long max = 0; 5664 5665 /* Find valid and maximum lowmem_reserve in the zone */ 5666 for (j = i; j < MAX_NR_ZONES; j++) { 5667 if (zone->lowmem_reserve[j] > max) 5668 max = zone->lowmem_reserve[j]; 5669 } 5670 5671 /* we treat the high watermark as reserved pages. */ 5672 max += high_wmark_pages(zone); 5673 5674 if (max > zone->managed_pages) 5675 max = zone->managed_pages; 5676 reserve_pages += max; 5677 /* 5678 * Lowmem reserves are not available to 5679 * GFP_HIGHUSER page cache allocations and 5680 * kswapd tries to balance zones to their high 5681 * watermark. As a result, neither should be 5682 * regarded as dirtyable memory, to prevent a 5683 * situation where reclaim has to clean pages 5684 * in order to balance the zones. 5685 */ 5686 zone->dirty_balance_reserve = max; 5687 } 5688 } 5689 dirty_balance_reserve = reserve_pages; 5690 totalreserve_pages = reserve_pages; 5691 } 5692 5693 /* 5694 * setup_per_zone_lowmem_reserve - called whenever 5695 * sysctl_lower_zone_reserve_ratio changes. Ensures that each zone 5696 * has a correct pages reserved value, so an adequate number of 5697 * pages are left in the zone after a successful __alloc_pages(). 5698 */ 5699 static void setup_per_zone_lowmem_reserve(void) 5700 { 5701 struct pglist_data *pgdat; 5702 enum zone_type j, idx; 5703 5704 for_each_online_pgdat(pgdat) { 5705 for (j = 0; j < MAX_NR_ZONES; j++) { 5706 struct zone *zone = pgdat->node_zones + j; 5707 unsigned long managed_pages = zone->managed_pages; 5708 5709 zone->lowmem_reserve[j] = 0; 5710 5711 idx = j; 5712 while (idx) { 5713 struct zone *lower_zone; 5714 5715 idx--; 5716 5717 if (sysctl_lowmem_reserve_ratio[idx] < 1) 5718 sysctl_lowmem_reserve_ratio[idx] = 1; 5719 5720 lower_zone = pgdat->node_zones + idx; 5721 lower_zone->lowmem_reserve[j] = managed_pages / 5722 sysctl_lowmem_reserve_ratio[idx]; 5723 managed_pages += lower_zone->managed_pages; 5724 } 5725 } 5726 } 5727 5728 /* update totalreserve_pages */ 5729 calculate_totalreserve_pages(); 5730 } 5731 5732 static void __setup_per_zone_wmarks(void) 5733 { 5734 unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10); 5735 unsigned long lowmem_pages = 0; 5736 struct zone *zone; 5737 unsigned long flags; 5738 5739 /* Calculate total number of !ZONE_HIGHMEM pages */ 5740 for_each_zone(zone) { 5741 if (!is_highmem(zone)) 5742 lowmem_pages += zone->managed_pages; 5743 } 5744 5745 for_each_zone(zone) { 5746 u64 tmp; 5747 5748 spin_lock_irqsave(&zone->lock, flags); 5749 tmp = (u64)pages_min * zone->managed_pages; 5750 do_div(tmp, lowmem_pages); 5751 if (is_highmem(zone)) { 5752 /* 5753 * __GFP_HIGH and PF_MEMALLOC allocations usually don't 5754 * need highmem pages, so cap pages_min to a small 5755 * value here. 5756 * 5757 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN) 5758 * deltas controls asynch page reclaim, and so should 5759 * not be capped for highmem. 5760 */ 5761 unsigned long min_pages; 5762 5763 min_pages = zone->managed_pages / 1024; 5764 min_pages = clamp(min_pages, SWAP_CLUSTER_MAX, 128UL); 5765 zone->watermark[WMARK_MIN] = min_pages; 5766 } else { 5767 /* 5768 * If it's a lowmem zone, reserve a number of pages 5769 * proportionate to the zone's size. 5770 */ 5771 zone->watermark[WMARK_MIN] = tmp; 5772 } 5773 5774 zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2); 5775 zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1); 5776 5777 __mod_zone_page_state(zone, NR_ALLOC_BATCH, 5778 high_wmark_pages(zone) - low_wmark_pages(zone) - 5779 atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH])); 5780 5781 setup_zone_migrate_reserve(zone); 5782 spin_unlock_irqrestore(&zone->lock, flags); 5783 } 5784 5785 /* update totalreserve_pages */ 5786 calculate_totalreserve_pages(); 5787 } 5788 5789 /** 5790 * setup_per_zone_wmarks - called when min_free_kbytes changes 5791 * or when memory is hot-{added|removed} 5792 * 5793 * Ensures that the watermark[min,low,high] values for each zone are set 5794 * correctly with respect to min_free_kbytes. 5795 */ 5796 void setup_per_zone_wmarks(void) 5797 { 5798 mutex_lock(&zonelists_mutex); 5799 __setup_per_zone_wmarks(); 5800 mutex_unlock(&zonelists_mutex); 5801 } 5802 5803 /* 5804 * The inactive anon list should be small enough that the VM never has to 5805 * do too much work, but large enough that each inactive page has a chance 5806 * to be referenced again before it is swapped out. 5807 * 5808 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to 5809 * INACTIVE_ANON pages on this zone's LRU, maintained by the 5810 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of 5811 * the anonymous pages are kept on the inactive list. 5812 * 5813 * total target max 5814 * memory ratio inactive anon 5815 * ------------------------------------- 5816 * 10MB 1 5MB 5817 * 100MB 1 50MB 5818 * 1GB 3 250MB 5819 * 10GB 10 0.9GB 5820 * 100GB 31 3GB 5821 * 1TB 101 10GB 5822 * 10TB 320 32GB 5823 */ 5824 static void __meminit calculate_zone_inactive_ratio(struct zone *zone) 5825 { 5826 unsigned int gb, ratio; 5827 5828 /* Zone size in gigabytes */ 5829 gb = zone->managed_pages >> (30 - PAGE_SHIFT); 5830 if (gb) 5831 ratio = int_sqrt(10 * gb); 5832 else 5833 ratio = 1; 5834 5835 zone->inactive_ratio = ratio; 5836 } 5837 5838 static void __meminit setup_per_zone_inactive_ratio(void) 5839 { 5840 struct zone *zone; 5841 5842 for_each_zone(zone) 5843 calculate_zone_inactive_ratio(zone); 5844 } 5845 5846 /* 5847 * Initialise min_free_kbytes. 5848 * 5849 * For small machines we want it small (128k min). For large machines 5850 * we want it large (64MB max). But it is not linear, because network 5851 * bandwidth does not increase linearly with machine size. We use 5852 * 5853 * min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy: 5854 * min_free_kbytes = sqrt(lowmem_kbytes * 16) 5855 * 5856 * which yields 5857 * 5858 * 16MB: 512k 5859 * 32MB: 724k 5860 * 64MB: 1024k 5861 * 128MB: 1448k 5862 * 256MB: 2048k 5863 * 512MB: 2896k 5864 * 1024MB: 4096k 5865 * 2048MB: 5792k 5866 * 4096MB: 8192k 5867 * 8192MB: 11584k 5868 * 16384MB: 16384k 5869 */ 5870 int __meminit init_per_zone_wmark_min(void) 5871 { 5872 unsigned long lowmem_kbytes; 5873 int new_min_free_kbytes; 5874 5875 lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10); 5876 new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16); 5877 5878 if (new_min_free_kbytes > user_min_free_kbytes) { 5879 min_free_kbytes = new_min_free_kbytes; 5880 if (min_free_kbytes < 128) 5881 min_free_kbytes = 128; 5882 if (min_free_kbytes > 65536) 5883 min_free_kbytes = 65536; 5884 } else { 5885 pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n", 5886 new_min_free_kbytes, user_min_free_kbytes); 5887 } 5888 setup_per_zone_wmarks(); 5889 refresh_zone_stat_thresholds(); 5890 setup_per_zone_lowmem_reserve(); 5891 setup_per_zone_inactive_ratio(); 5892 return 0; 5893 } 5894 module_init(init_per_zone_wmark_min) 5895 5896 /* 5897 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 5898 * that we can call two helper functions whenever min_free_kbytes 5899 * changes. 5900 */ 5901 int min_free_kbytes_sysctl_handler(struct ctl_table *table, int write, 5902 void __user *buffer, size_t *length, loff_t *ppos) 5903 { 5904 int rc; 5905 5906 rc = proc_dointvec_minmax(table, write, buffer, length, ppos); 5907 if (rc) 5908 return rc; 5909 5910 if (write) { 5911 user_min_free_kbytes = min_free_kbytes; 5912 setup_per_zone_wmarks(); 5913 } 5914 return 0; 5915 } 5916 5917 #ifdef CONFIG_NUMA 5918 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *table, int write, 5919 void __user *buffer, size_t *length, loff_t *ppos) 5920 { 5921 struct zone *zone; 5922 int rc; 5923 5924 rc = proc_dointvec_minmax(table, write, buffer, length, ppos); 5925 if (rc) 5926 return rc; 5927 5928 for_each_zone(zone) 5929 zone->min_unmapped_pages = (zone->managed_pages * 5930 sysctl_min_unmapped_ratio) / 100; 5931 return 0; 5932 } 5933 5934 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *table, int write, 5935 void __user *buffer, size_t *length, loff_t *ppos) 5936 { 5937 struct zone *zone; 5938 int rc; 5939 5940 rc = proc_dointvec_minmax(table, write, buffer, length, ppos); 5941 if (rc) 5942 return rc; 5943 5944 for_each_zone(zone) 5945 zone->min_slab_pages = (zone->managed_pages * 5946 sysctl_min_slab_ratio) / 100; 5947 return 0; 5948 } 5949 #endif 5950 5951 /* 5952 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around 5953 * proc_dointvec() so that we can call setup_per_zone_lowmem_reserve() 5954 * whenever sysctl_lowmem_reserve_ratio changes. 5955 * 5956 * The reserve ratio obviously has absolutely no relation with the 5957 * minimum watermarks. The lowmem reserve ratio can only make sense 5958 * if in function of the boot time zone sizes. 5959 */ 5960 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write, 5961 void __user *buffer, size_t *length, loff_t *ppos) 5962 { 5963 proc_dointvec_minmax(table, write, buffer, length, ppos); 5964 setup_per_zone_lowmem_reserve(); 5965 return 0; 5966 } 5967 5968 /* 5969 * percpu_pagelist_fraction - changes the pcp->high for each zone on each 5970 * cpu. It is the fraction of total pages in each zone that a hot per cpu 5971 * pagelist can have before it gets flushed back to buddy allocator. 5972 */ 5973 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write, 5974 void __user *buffer, size_t *length, loff_t *ppos) 5975 { 5976 struct zone *zone; 5977 int old_percpu_pagelist_fraction; 5978 int ret; 5979 5980 mutex_lock(&pcp_batch_high_lock); 5981 old_percpu_pagelist_fraction = percpu_pagelist_fraction; 5982 5983 ret = proc_dointvec_minmax(table, write, buffer, length, ppos); 5984 if (!write || ret < 0) 5985 goto out; 5986 5987 /* Sanity checking to avoid pcp imbalance */ 5988 if (percpu_pagelist_fraction && 5989 percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) { 5990 percpu_pagelist_fraction = old_percpu_pagelist_fraction; 5991 ret = -EINVAL; 5992 goto out; 5993 } 5994 5995 /* No change? */ 5996 if (percpu_pagelist_fraction == old_percpu_pagelist_fraction) 5997 goto out; 5998 5999 for_each_populated_zone(zone) { 6000 unsigned int cpu; 6001 6002 for_each_possible_cpu(cpu) 6003 pageset_set_high_and_batch(zone, 6004 per_cpu_ptr(zone->pageset, cpu)); 6005 } 6006 out: 6007 mutex_unlock(&pcp_batch_high_lock); 6008 return ret; 6009 } 6010 6011 int hashdist = HASHDIST_DEFAULT; 6012 6013 #ifdef CONFIG_NUMA 6014 static int __init set_hashdist(char *str) 6015 { 6016 if (!str) 6017 return 0; 6018 hashdist = simple_strtoul(str, &str, 0); 6019 return 1; 6020 } 6021 __setup("hashdist=", set_hashdist); 6022 #endif 6023 6024 /* 6025 * allocate a large system hash table from bootmem 6026 * - it is assumed that the hash table must contain an exact power-of-2 6027 * quantity of entries 6028 * - limit is the number of hash buckets, not the total allocation size 6029 */ 6030 void *__init alloc_large_system_hash(const char *tablename, 6031 unsigned long bucketsize, 6032 unsigned long numentries, 6033 int scale, 6034 int flags, 6035 unsigned int *_hash_shift, 6036 unsigned int *_hash_mask, 6037 unsigned long low_limit, 6038 unsigned long high_limit) 6039 { 6040 unsigned long long max = high_limit; 6041 unsigned long log2qty, size; 6042 void *table = NULL; 6043 6044 /* allow the kernel cmdline to have a say */ 6045 if (!numentries) { 6046 /* round applicable memory size up to nearest megabyte */ 6047 numentries = nr_kernel_pages; 6048 6049 /* It isn't necessary when PAGE_SIZE >= 1MB */ 6050 if (PAGE_SHIFT < 20) 6051 numentries = round_up(numentries, (1<<20)/PAGE_SIZE); 6052 6053 /* limit to 1 bucket per 2^scale bytes of low memory */ 6054 if (scale > PAGE_SHIFT) 6055 numentries >>= (scale - PAGE_SHIFT); 6056 else 6057 numentries <<= (PAGE_SHIFT - scale); 6058 6059 /* Make sure we've got at least a 0-order allocation.. */ 6060 if (unlikely(flags & HASH_SMALL)) { 6061 /* Makes no sense without HASH_EARLY */ 6062 WARN_ON(!(flags & HASH_EARLY)); 6063 if (!(numentries >> *_hash_shift)) { 6064 numentries = 1UL << *_hash_shift; 6065 BUG_ON(!numentries); 6066 } 6067 } else if (unlikely((numentries * bucketsize) < PAGE_SIZE)) 6068 numentries = PAGE_SIZE / bucketsize; 6069 } 6070 numentries = roundup_pow_of_two(numentries); 6071 6072 /* limit allocation size to 1/16 total memory by default */ 6073 if (max == 0) { 6074 max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4; 6075 do_div(max, bucketsize); 6076 } 6077 max = min(max, 0x80000000ULL); 6078 6079 if (numentries < low_limit) 6080 numentries = low_limit; 6081 if (numentries > max) 6082 numentries = max; 6083 6084 log2qty = ilog2(numentries); 6085 6086 do { 6087 size = bucketsize << log2qty; 6088 if (flags & HASH_EARLY) 6089 table = memblock_virt_alloc_nopanic(size, 0); 6090 else if (hashdist) 6091 table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); 6092 else { 6093 /* 6094 * If bucketsize is not a power-of-two, we may free 6095 * some pages at the end of hash table which 6096 * alloc_pages_exact() automatically does 6097 */ 6098 if (get_order(size) < MAX_ORDER) { 6099 table = alloc_pages_exact(size, GFP_ATOMIC); 6100 kmemleak_alloc(table, size, 1, GFP_ATOMIC); 6101 } 6102 } 6103 } while (!table && size > PAGE_SIZE && --log2qty); 6104 6105 if (!table) 6106 panic("Failed to allocate %s hash table\n", tablename); 6107 6108 printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n", 6109 tablename, 6110 (1UL << log2qty), 6111 ilog2(size) - PAGE_SHIFT, 6112 size); 6113 6114 if (_hash_shift) 6115 *_hash_shift = log2qty; 6116 if (_hash_mask) 6117 *_hash_mask = (1 << log2qty) - 1; 6118 6119 return table; 6120 } 6121 6122 /* Return a pointer to the bitmap storing bits affecting a block of pages */ 6123 static inline unsigned long *get_pageblock_bitmap(struct zone *zone, 6124 unsigned long pfn) 6125 { 6126 #ifdef CONFIG_SPARSEMEM 6127 return __pfn_to_section(pfn)->pageblock_flags; 6128 #else 6129 return zone->pageblock_flags; 6130 #endif /* CONFIG_SPARSEMEM */ 6131 } 6132 6133 static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) 6134 { 6135 #ifdef CONFIG_SPARSEMEM 6136 pfn &= (PAGES_PER_SECTION-1); 6137 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 6138 #else 6139 pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages); 6140 return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; 6141 #endif /* CONFIG_SPARSEMEM */ 6142 } 6143 6144 /** 6145 * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages 6146 * @page: The page within the block of interest 6147 * @pfn: The target page frame number 6148 * @end_bitidx: The last bit of interest to retrieve 6149 * @mask: mask of bits that the caller is interested in 6150 * 6151 * Return: pageblock_bits flags 6152 */ 6153 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn, 6154 unsigned long end_bitidx, 6155 unsigned long mask) 6156 { 6157 struct zone *zone; 6158 unsigned long *bitmap; 6159 unsigned long bitidx, word_bitidx; 6160 unsigned long word; 6161 6162 zone = page_zone(page); 6163 bitmap = get_pageblock_bitmap(zone, pfn); 6164 bitidx = pfn_to_bitidx(zone, pfn); 6165 word_bitidx = bitidx / BITS_PER_LONG; 6166 bitidx &= (BITS_PER_LONG-1); 6167 6168 word = bitmap[word_bitidx]; 6169 bitidx += end_bitidx; 6170 return (word >> (BITS_PER_LONG - bitidx - 1)) & mask; 6171 } 6172 6173 /** 6174 * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages 6175 * @page: The page within the block of interest 6176 * @flags: The flags to set 6177 * @pfn: The target page frame number 6178 * @end_bitidx: The last bit of interest 6179 * @mask: mask of bits that the caller is interested in 6180 */ 6181 void set_pfnblock_flags_mask(struct page *page, unsigned long flags, 6182 unsigned long pfn, 6183 unsigned long end_bitidx, 6184 unsigned long mask) 6185 { 6186 struct zone *zone; 6187 unsigned long *bitmap; 6188 unsigned long bitidx, word_bitidx; 6189 unsigned long old_word, word; 6190 6191 BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4); 6192 6193 zone = page_zone(page); 6194 bitmap = get_pageblock_bitmap(zone, pfn); 6195 bitidx = pfn_to_bitidx(zone, pfn); 6196 word_bitidx = bitidx / BITS_PER_LONG; 6197 bitidx &= (BITS_PER_LONG-1); 6198 6199 VM_BUG_ON_PAGE(!zone_spans_pfn(zone, pfn), page); 6200 6201 bitidx += end_bitidx; 6202 mask <<= (BITS_PER_LONG - bitidx - 1); 6203 flags <<= (BITS_PER_LONG - bitidx - 1); 6204 6205 word = ACCESS_ONCE(bitmap[word_bitidx]); 6206 for (;;) { 6207 old_word = cmpxchg(&bitmap[word_bitidx], word, (word & ~mask) | flags); 6208 if (word == old_word) 6209 break; 6210 word = old_word; 6211 } 6212 } 6213 6214 /* 6215 * This function checks whether pageblock includes unmovable pages or not. 6216 * If @count is not zero, it is okay to include less @count unmovable pages 6217 * 6218 * PageLRU check without isolation or lru_lock could race so that 6219 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't 6220 * expect this function should be exact. 6221 */ 6222 bool has_unmovable_pages(struct zone *zone, struct page *page, int count, 6223 bool skip_hwpoisoned_pages) 6224 { 6225 unsigned long pfn, iter, found; 6226 int mt; 6227 6228 /* 6229 * For avoiding noise data, lru_add_drain_all() should be called 6230 * If ZONE_MOVABLE, the zone never contains unmovable pages 6231 */ 6232 if (zone_idx(zone) == ZONE_MOVABLE) 6233 return false; 6234 mt = get_pageblock_migratetype(page); 6235 if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt)) 6236 return false; 6237 6238 pfn = page_to_pfn(page); 6239 for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) { 6240 unsigned long check = pfn + iter; 6241 6242 if (!pfn_valid_within(check)) 6243 continue; 6244 6245 page = pfn_to_page(check); 6246 6247 /* 6248 * Hugepages are not in LRU lists, but they're movable. 6249 * We need not scan over tail pages bacause we don't 6250 * handle each tail page individually in migration. 6251 */ 6252 if (PageHuge(page)) { 6253 iter = round_up(iter + 1, 1<<compound_order(page)) - 1; 6254 continue; 6255 } 6256 6257 /* 6258 * We can't use page_count without pin a page 6259 * because another CPU can free compound page. 6260 * This check already skips compound tails of THP 6261 * because their page->_count is zero at all time. 6262 */ 6263 if (!atomic_read(&page->_count)) { 6264 if (PageBuddy(page)) 6265 iter += (1 << page_order(page)) - 1; 6266 continue; 6267 } 6268 6269 /* 6270 * The HWPoisoned page may be not in buddy system, and 6271 * page_count() is not 0. 6272 */ 6273 if (skip_hwpoisoned_pages && PageHWPoison(page)) 6274 continue; 6275 6276 if (!PageLRU(page)) 6277 found++; 6278 /* 6279 * If there are RECLAIMABLE pages, we need to check 6280 * it. But now, memory offline itself doesn't call 6281 * shrink_node_slabs() and it still to be fixed. 6282 */ 6283 /* 6284 * If the page is not RAM, page_count()should be 0. 6285 * we don't need more check. This is an _used_ not-movable page. 6286 * 6287 * The problematic thing here is PG_reserved pages. PG_reserved 6288 * is set to both of a memory hole page and a _used_ kernel 6289 * page at boot. 6290 */ 6291 if (found > count) 6292 return true; 6293 } 6294 return false; 6295 } 6296 6297 bool is_pageblock_removable_nolock(struct page *page) 6298 { 6299 struct zone *zone; 6300 unsigned long pfn; 6301 6302 /* 6303 * We have to be careful here because we are iterating over memory 6304 * sections which are not zone aware so we might end up outside of 6305 * the zone but still within the section. 6306 * We have to take care about the node as well. If the node is offline 6307 * its NODE_DATA will be NULL - see page_zone. 6308 */ 6309 if (!node_online(page_to_nid(page))) 6310 return false; 6311 6312 zone = page_zone(page); 6313 pfn = page_to_pfn(page); 6314 if (!zone_spans_pfn(zone, pfn)) 6315 return false; 6316 6317 return !has_unmovable_pages(zone, page, 0, true); 6318 } 6319 6320 #ifdef CONFIG_CMA 6321 6322 static unsigned long pfn_max_align_down(unsigned long pfn) 6323 { 6324 return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES, 6325 pageblock_nr_pages) - 1); 6326 } 6327 6328 static unsigned long pfn_max_align_up(unsigned long pfn) 6329 { 6330 return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES, 6331 pageblock_nr_pages)); 6332 } 6333 6334 /* [start, end) must belong to a single zone. */ 6335 static int __alloc_contig_migrate_range(struct compact_control *cc, 6336 unsigned long start, unsigned long end) 6337 { 6338 /* This function is based on compact_zone() from compaction.c. */ 6339 unsigned long nr_reclaimed; 6340 unsigned long pfn = start; 6341 unsigned int tries = 0; 6342 int ret = 0; 6343 6344 migrate_prep(); 6345 6346 while (pfn < end || !list_empty(&cc->migratepages)) { 6347 if (fatal_signal_pending(current)) { 6348 ret = -EINTR; 6349 break; 6350 } 6351 6352 if (list_empty(&cc->migratepages)) { 6353 cc->nr_migratepages = 0; 6354 pfn = isolate_migratepages_range(cc, pfn, end); 6355 if (!pfn) { 6356 ret = -EINTR; 6357 break; 6358 } 6359 tries = 0; 6360 } else if (++tries == 5) { 6361 ret = ret < 0 ? ret : -EBUSY; 6362 break; 6363 } 6364 6365 nr_reclaimed = reclaim_clean_pages_from_list(cc->zone, 6366 &cc->migratepages); 6367 cc->nr_migratepages -= nr_reclaimed; 6368 6369 ret = migrate_pages(&cc->migratepages, alloc_migrate_target, 6370 NULL, 0, cc->mode, MR_CMA); 6371 } 6372 if (ret < 0) { 6373 putback_movable_pages(&cc->migratepages); 6374 return ret; 6375 } 6376 return 0; 6377 } 6378 6379 /** 6380 * alloc_contig_range() -- tries to allocate given range of pages 6381 * @start: start PFN to allocate 6382 * @end: one-past-the-last PFN to allocate 6383 * @migratetype: migratetype of the underlaying pageblocks (either 6384 * #MIGRATE_MOVABLE or #MIGRATE_CMA). All pageblocks 6385 * in range must have the same migratetype and it must 6386 * be either of the two. 6387 * 6388 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES 6389 * aligned, however it's the caller's responsibility to guarantee that 6390 * we are the only thread that changes migrate type of pageblocks the 6391 * pages fall in. 6392 * 6393 * The PFN range must belong to a single zone. 6394 * 6395 * Returns zero on success or negative error code. On success all 6396 * pages which PFN is in [start, end) are allocated for the caller and 6397 * need to be freed with free_contig_range(). 6398 */ 6399 int alloc_contig_range(unsigned long start, unsigned long end, 6400 unsigned migratetype) 6401 { 6402 unsigned long outer_start, outer_end; 6403 int ret = 0, order; 6404 6405 struct compact_control cc = { 6406 .nr_migratepages = 0, 6407 .order = -1, 6408 .zone = page_zone(pfn_to_page(start)), 6409 .mode = MIGRATE_SYNC, 6410 .ignore_skip_hint = true, 6411 }; 6412 INIT_LIST_HEAD(&cc.migratepages); 6413 6414 /* 6415 * What we do here is we mark all pageblocks in range as 6416 * MIGRATE_ISOLATE. Because pageblock and max order pages may 6417 * have different sizes, and due to the way page allocator 6418 * work, we align the range to biggest of the two pages so 6419 * that page allocator won't try to merge buddies from 6420 * different pageblocks and change MIGRATE_ISOLATE to some 6421 * other migration type. 6422 * 6423 * Once the pageblocks are marked as MIGRATE_ISOLATE, we 6424 * migrate the pages from an unaligned range (ie. pages that 6425 * we are interested in). This will put all the pages in 6426 * range back to page allocator as MIGRATE_ISOLATE. 6427 * 6428 * When this is done, we take the pages in range from page 6429 * allocator removing them from the buddy system. This way 6430 * page allocator will never consider using them. 6431 * 6432 * This lets us mark the pageblocks back as 6433 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the 6434 * aligned range but not in the unaligned, original range are 6435 * put back to page allocator so that buddy can use them. 6436 */ 6437 6438 ret = start_isolate_page_range(pfn_max_align_down(start), 6439 pfn_max_align_up(end), migratetype, 6440 false); 6441 if (ret) 6442 return ret; 6443 6444 ret = __alloc_contig_migrate_range(&cc, start, end); 6445 if (ret) 6446 goto done; 6447 6448 /* 6449 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES 6450 * aligned blocks that are marked as MIGRATE_ISOLATE. What's 6451 * more, all pages in [start, end) are free in page allocator. 6452 * What we are going to do is to allocate all pages from 6453 * [start, end) (that is remove them from page allocator). 6454 * 6455 * The only problem is that pages at the beginning and at the 6456 * end of interesting range may be not aligned with pages that 6457 * page allocator holds, ie. they can be part of higher order 6458 * pages. Because of this, we reserve the bigger range and 6459 * once this is done free the pages we are not interested in. 6460 * 6461 * We don't have to hold zone->lock here because the pages are 6462 * isolated thus they won't get removed from buddy. 6463 */ 6464 6465 lru_add_drain_all(); 6466 drain_all_pages(cc.zone); 6467 6468 order = 0; 6469 outer_start = start; 6470 while (!PageBuddy(pfn_to_page(outer_start))) { 6471 if (++order >= MAX_ORDER) { 6472 ret = -EBUSY; 6473 goto done; 6474 } 6475 outer_start &= ~0UL << order; 6476 } 6477 6478 /* Make sure the range is really isolated. */ 6479 if (test_pages_isolated(outer_start, end, false)) { 6480 pr_info("%s: [%lx, %lx) PFNs busy\n", 6481 __func__, outer_start, end); 6482 ret = -EBUSY; 6483 goto done; 6484 } 6485 6486 /* Grab isolated pages from freelists. */ 6487 outer_end = isolate_freepages_range(&cc, outer_start, end); 6488 if (!outer_end) { 6489 ret = -EBUSY; 6490 goto done; 6491 } 6492 6493 /* Free head and tail (if any) */ 6494 if (start != outer_start) 6495 free_contig_range(outer_start, start - outer_start); 6496 if (end != outer_end) 6497 free_contig_range(end, outer_end - end); 6498 6499 done: 6500 undo_isolate_page_range(pfn_max_align_down(start), 6501 pfn_max_align_up(end), migratetype); 6502 return ret; 6503 } 6504 6505 void free_contig_range(unsigned long pfn, unsigned nr_pages) 6506 { 6507 unsigned int count = 0; 6508 6509 for (; nr_pages--; pfn++) { 6510 struct page *page = pfn_to_page(pfn); 6511 6512 count += page_count(page) != 1; 6513 __free_page(page); 6514 } 6515 WARN(count != 0, "%d pages are still in use!\n", count); 6516 } 6517 #endif 6518 6519 #ifdef CONFIG_MEMORY_HOTPLUG 6520 /* 6521 * The zone indicated has a new number of managed_pages; batch sizes and percpu 6522 * page high values need to be recalulated. 6523 */ 6524 void __meminit zone_pcp_update(struct zone *zone) 6525 { 6526 unsigned cpu; 6527 mutex_lock(&pcp_batch_high_lock); 6528 for_each_possible_cpu(cpu) 6529 pageset_set_high_and_batch(zone, 6530 per_cpu_ptr(zone->pageset, cpu)); 6531 mutex_unlock(&pcp_batch_high_lock); 6532 } 6533 #endif 6534 6535 void zone_pcp_reset(struct zone *zone) 6536 { 6537 unsigned long flags; 6538 int cpu; 6539 struct per_cpu_pageset *pset; 6540 6541 /* avoid races with drain_pages() */ 6542 local_irq_save(flags); 6543 if (zone->pageset != &boot_pageset) { 6544 for_each_online_cpu(cpu) { 6545 pset = per_cpu_ptr(zone->pageset, cpu); 6546 drain_zonestat(zone, pset); 6547 } 6548 free_percpu(zone->pageset); 6549 zone->pageset = &boot_pageset; 6550 } 6551 local_irq_restore(flags); 6552 } 6553 6554 #ifdef CONFIG_MEMORY_HOTREMOVE 6555 /* 6556 * All pages in the range must be isolated before calling this. 6557 */ 6558 void 6559 __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) 6560 { 6561 struct page *page; 6562 struct zone *zone; 6563 unsigned int order, i; 6564 unsigned long pfn; 6565 unsigned long flags; 6566 /* find the first valid pfn */ 6567 for (pfn = start_pfn; pfn < end_pfn; pfn++) 6568 if (pfn_valid(pfn)) 6569 break; 6570 if (pfn == end_pfn) 6571 return; 6572 zone = page_zone(pfn_to_page(pfn)); 6573 spin_lock_irqsave(&zone->lock, flags); 6574 pfn = start_pfn; 6575 while (pfn < end_pfn) { 6576 if (!pfn_valid(pfn)) { 6577 pfn++; 6578 continue; 6579 } 6580 page = pfn_to_page(pfn); 6581 /* 6582 * The HWPoisoned page may be not in buddy system, and 6583 * page_count() is not 0. 6584 */ 6585 if (unlikely(!PageBuddy(page) && PageHWPoison(page))) { 6586 pfn++; 6587 SetPageReserved(page); 6588 continue; 6589 } 6590 6591 BUG_ON(page_count(page)); 6592 BUG_ON(!PageBuddy(page)); 6593 order = page_order(page); 6594 #ifdef CONFIG_DEBUG_VM 6595 printk(KERN_INFO "remove from free list %lx %d %lx\n", 6596 pfn, 1 << order, end_pfn); 6597 #endif 6598 list_del(&page->lru); 6599 rmv_page_order(page); 6600 zone->free_area[order].nr_free--; 6601 for (i = 0; i < (1 << order); i++) 6602 SetPageReserved((page+i)); 6603 pfn += (1 << order); 6604 } 6605 spin_unlock_irqrestore(&zone->lock, flags); 6606 } 6607 #endif 6608 6609 #ifdef CONFIG_MEMORY_FAILURE 6610 bool is_free_buddy_page(struct page *page) 6611 { 6612 struct zone *zone = page_zone(page); 6613 unsigned long pfn = page_to_pfn(page); 6614 unsigned long flags; 6615 unsigned int order; 6616 6617 spin_lock_irqsave(&zone->lock, flags); 6618 for (order = 0; order < MAX_ORDER; order++) { 6619 struct page *page_head = page - (pfn & ((1 << order) - 1)); 6620 6621 if (PageBuddy(page_head) && page_order(page_head) >= order) 6622 break; 6623 } 6624 spin_unlock_irqrestore(&zone->lock, flags); 6625 6626 return order < MAX_ORDER; 6627 } 6628 #endif 6629