linux/mm/page_alloc.c
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   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/compiler.h>
  25#include <linux/kernel.h>
  26#include <linux/module.h>
  27#include <linux/suspend.h>
  28#include <linux/pagevec.h>
  29#include <linux/blkdev.h>
  30#include <linux/slab.h>
  31#include <linux/oom.h>
  32#include <linux/notifier.h>
  33#include <linux/topology.h>
  34#include <linux/sysctl.h>
  35#include <linux/cpu.h>
  36#include <linux/cpuset.h>
  37#include <linux/memory_hotplug.h>
  38#include <linux/nodemask.h>
  39#include <linux/vmalloc.h>
  40#include <linux/mempolicy.h>
  41#include <linux/stop_machine.h>
  42#include <linux/sort.h>
  43#include <linux/pfn.h>
  44#include <linux/backing-dev.h>
  45#include <linux/fault-inject.h>
  46#include <linux/page-isolation.h>
  47#include <linux/memcontrol.h>
  48#include <linux/debugobjects.h>
  49
  50#include <asm/tlbflush.h>
  51#include <asm/div64.h>
  52#include "internal.h"
  53
  54/*
  55 * Array of node states.
  56 */
  57nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
  58        [N_POSSIBLE] = NODE_MASK_ALL,
  59        [N_ONLINE] = { { [0] = 1UL } },
  60#ifndef CONFIG_NUMA
  61        [N_NORMAL_MEMORY] = { { [0] = 1UL } },
  62#ifdef CONFIG_HIGHMEM
  63        [N_HIGH_MEMORY] = { { [0] = 1UL } },
  64#endif
  65        [N_CPU] = { { [0] = 1UL } },
  66#endif  /* NUMA */
  67};
  68EXPORT_SYMBOL(node_states);
  69
  70unsigned long totalram_pages __read_mostly;
  71unsigned long totalreserve_pages __read_mostly;
  72long nr_swap_pages;
  73int percpu_pagelist_fraction;
  74
  75#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
  76int pageblock_order __read_mostly;
  77#endif
  78
  79static void __free_pages_ok(struct page *page, unsigned int order);
  80
  81/*
  82 * results with 256, 32 in the lowmem_reserve sysctl:
  83 *      1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
  84 *      1G machine -> (16M dma, 784M normal, 224M high)
  85 *      NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
  86 *      HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
  87 *      HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
  88 *
  89 * TBD: should special case ZONE_DMA32 machines here - in those we normally
  90 * don't need any ZONE_NORMAL reservation
  91 */
  92int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
  93#ifdef CONFIG_ZONE_DMA
  94         256,
  95#endif
  96#ifdef CONFIG_ZONE_DMA32
  97         256,
  98#endif
  99#ifdef CONFIG_HIGHMEM
 100         32,
 101#endif
 102         32,
 103};
 104
 105EXPORT_SYMBOL(totalram_pages);
 106
 107static char * const zone_names[MAX_NR_ZONES] = {
 108#ifdef CONFIG_ZONE_DMA
 109         "DMA",
 110#endif
 111#ifdef CONFIG_ZONE_DMA32
 112         "DMA32",
 113#endif
 114         "Normal",
 115#ifdef CONFIG_HIGHMEM
 116         "HighMem",
 117#endif
 118         "Movable",
 119};
 120
 121int min_free_kbytes = 1024;
 122
 123unsigned long __meminitdata nr_kernel_pages;
 124unsigned long __meminitdata nr_all_pages;
 125static unsigned long __meminitdata dma_reserve;
 126
 127#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
 128  /*
 129   * MAX_ACTIVE_REGIONS determines the maximum number of distinct
 130   * ranges of memory (RAM) that may be registered with add_active_range().
 131   * Ranges passed to add_active_range() will be merged if possible
 132   * so the number of times add_active_range() can be called is
 133   * related to the number of nodes and the number of holes
 134   */
 135  #ifdef CONFIG_MAX_ACTIVE_REGIONS
 136    /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
 137    #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
 138  #else
 139    #if MAX_NUMNODES >= 32
 140      /* If there can be many nodes, allow up to 50 holes per node */
 141      #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
 142    #else
 143      /* By default, allow up to 256 distinct regions */
 144      #define MAX_ACTIVE_REGIONS 256
 145    #endif
 146  #endif
 147
 148  static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS];
 149  static int __meminitdata nr_nodemap_entries;
 150  static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
 151  static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
 152#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
 153  static unsigned long __meminitdata node_boundary_start_pfn[MAX_NUMNODES];
 154  static unsigned long __meminitdata node_boundary_end_pfn[MAX_NUMNODES];
 155#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
 156  unsigned long __initdata required_kernelcore;
 157  static unsigned long __initdata required_movablecore;
 158  unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
 159
 160  /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
 161  int movable_zone;
 162  EXPORT_SYMBOL(movable_zone);
 163#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
 164
 165#if MAX_NUMNODES > 1
 166int nr_node_ids __read_mostly = MAX_NUMNODES;
 167EXPORT_SYMBOL(nr_node_ids);
 168#endif
 169
 170int page_group_by_mobility_disabled __read_mostly;
 171
 172static void set_pageblock_migratetype(struct page *page, int migratetype)
 173{
 174        set_pageblock_flags_group(page, (unsigned long)migratetype,
 175                                        PB_migrate, PB_migrate_end);
 176}
 177
 178#ifdef CONFIG_DEBUG_VM
 179static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
 180{
 181        int ret = 0;
 182        unsigned seq;
 183        unsigned long pfn = page_to_pfn(page);
 184
 185        do {
 186                seq = zone_span_seqbegin(zone);
 187                if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
 188                        ret = 1;
 189                else if (pfn < zone->zone_start_pfn)
 190                        ret = 1;
 191        } while (zone_span_seqretry(zone, seq));
 192
 193        return ret;
 194}
 195
 196static int page_is_consistent(struct zone *zone, struct page *page)
 197{
 198        if (!pfn_valid_within(page_to_pfn(page)))
 199                return 0;
 200        if (zone != page_zone(page))
 201                return 0;
 202
 203        return 1;
 204}
 205/*
 206 * Temporary debugging check for pages not lying within a given zone.
 207 */
 208static int bad_range(struct zone *zone, struct page *page)
 209{
 210        if (page_outside_zone_boundaries(zone, page))
 211                return 1;
 212        if (!page_is_consistent(zone, page))
 213                return 1;
 214
 215        return 0;
 216}
 217#else
 218static inline int bad_range(struct zone *zone, struct page *page)
 219{
 220        return 0;
 221}
 222#endif
 223
 224static void bad_page(struct page *page)
 225{
 226        void *pc = page_get_page_cgroup(page);
 227
 228        printk(KERN_EMERG "Bad page state in process '%s'\n" KERN_EMERG
 229                "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
 230                current->comm, page, (int)(2*sizeof(unsigned long)),
 231                (unsigned long)page->flags, page->mapping,
 232                page_mapcount(page), page_count(page));
 233        if (pc) {
 234                printk(KERN_EMERG "cgroup:%p\n", pc);
 235                page_reset_bad_cgroup(page);
 236        }
 237        printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n"
 238                KERN_EMERG "Backtrace:\n");
 239        dump_stack();
 240        page->flags &= ~PAGE_FLAGS_CLEAR_WHEN_BAD;
 241        set_page_count(page, 0);
 242        reset_page_mapcount(page);
 243        page->mapping = NULL;
 244        add_taint(TAINT_BAD_PAGE);
 245}
 246
 247/*
 248 * Higher-order pages are called "compound pages".  They are structured thusly:
 249 *
 250 * The first PAGE_SIZE page is called the "head page".
 251 *
 252 * The remaining PAGE_SIZE pages are called "tail pages".
 253 *
 254 * All pages have PG_compound set.  All pages have their ->private pointing at
 255 * the head page (even the head page has this).
 256 *
 257 * The first tail page's ->lru.next holds the address of the compound page's
 258 * put_page() function.  Its ->lru.prev holds the order of allocation.
 259 * This usage means that zero-order pages may not be compound.
 260 */
 261
 262static void free_compound_page(struct page *page)
 263{
 264        __free_pages_ok(page, compound_order(page));
 265}
 266
 267static void prep_compound_page(struct page *page, unsigned long order)
 268{
 269        int i;
 270        int nr_pages = 1 << order;
 271
 272        set_compound_page_dtor(page, free_compound_page);
 273        set_compound_order(page, order);
 274        __SetPageHead(page);
 275        for (i = 1; i < nr_pages; i++) {
 276                struct page *p = page + i;
 277
 278                __SetPageTail(p);
 279                p->first_page = page;
 280        }
 281}
 282
 283static void destroy_compound_page(struct page *page, unsigned long order)
 284{
 285        int i;
 286        int nr_pages = 1 << order;
 287
 288        if (unlikely(compound_order(page) != order))
 289                bad_page(page);
 290
 291        if (unlikely(!PageHead(page)))
 292                        bad_page(page);
 293        __ClearPageHead(page);
 294        for (i = 1; i < nr_pages; i++) {
 295                struct page *p = page + i;
 296
 297                if (unlikely(!PageTail(p) |
 298                                (p->first_page != page)))
 299                        bad_page(page);
 300                __ClearPageTail(p);
 301        }
 302}
 303
 304static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
 305{
 306        int i;
 307
 308        /*
 309         * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
 310         * and __GFP_HIGHMEM from hard or soft interrupt context.
 311         */
 312        VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
 313        for (i = 0; i < (1 << order); i++)
 314                clear_highpage(page + i);
 315}
 316
 317static inline void set_page_order(struct page *page, int order)
 318{
 319        set_page_private(page, order);
 320        __SetPageBuddy(page);
 321}
 322
 323static inline void rmv_page_order(struct page *page)
 324{
 325        __ClearPageBuddy(page);
 326        set_page_private(page, 0);
 327}
 328
 329/*
 330 * Locate the struct page for both the matching buddy in our
 331 * pair (buddy1) and the combined O(n+1) page they form (page).
 332 *
 333 * 1) Any buddy B1 will have an order O twin B2 which satisfies
 334 * the following equation:
 335 *     B2 = B1 ^ (1 << O)
 336 * For example, if the starting buddy (buddy2) is #8 its order
 337 * 1 buddy is #10:
 338 *     B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
 339 *
 340 * 2) Any buddy B will have an order O+1 parent P which
 341 * satisfies the following equation:
 342 *     P = B & ~(1 << O)
 343 *
 344 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
 345 */
 346static inline struct page *
 347__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order)
 348{
 349        unsigned long buddy_idx = page_idx ^ (1 << order);
 350
 351        return page + (buddy_idx - page_idx);
 352}
 353
 354static inline unsigned long
 355__find_combined_index(unsigned long page_idx, unsigned int order)
 356{
 357        return (page_idx & ~(1 << order));
 358}
 359
 360/*
 361 * This function checks whether a page is free && is the buddy
 362 * we can do coalesce a page and its buddy if
 363 * (a) the buddy is not in a hole &&
 364 * (b) the buddy is in the buddy system &&
 365 * (c) a page and its buddy have the same order &&
 366 * (d) a page and its buddy are in the same zone.
 367 *
 368 * For recording whether a page is in the buddy system, we use PG_buddy.
 369 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
 370 *
 371 * For recording page's order, we use page_private(page).
 372 */
 373static inline int page_is_buddy(struct page *page, struct page *buddy,
 374                                                                int order)
 375{
 376        if (!pfn_valid_within(page_to_pfn(buddy)))
 377                return 0;
 378
 379        if (page_zone_id(page) != page_zone_id(buddy))
 380                return 0;
 381
 382        if (PageBuddy(buddy) && page_order(buddy) == order) {
 383                BUG_ON(page_count(buddy) != 0);
 384                return 1;
 385        }
 386        return 0;
 387}
 388
 389/*
 390 * Freeing function for a buddy system allocator.
 391 *
 392 * The concept of a buddy system is to maintain direct-mapped table
 393 * (containing bit values) for memory blocks of various "orders".
 394 * The bottom level table contains the map for the smallest allocatable
 395 * units of memory (here, pages), and each level above it describes
 396 * pairs of units from the levels below, hence, "buddies".
 397 * At a high level, all that happens here is marking the table entry
 398 * at the bottom level available, and propagating the changes upward
 399 * as necessary, plus some accounting needed to play nicely with other
 400 * parts of the VM system.
 401 * At each level, we keep a list of pages, which are heads of continuous
 402 * free pages of length of (1 << order) and marked with PG_buddy. Page's
 403 * order is recorded in page_private(page) field.
 404 * So when we are allocating or freeing one, we can derive the state of the
 405 * other.  That is, if we allocate a small block, and both were   
 406 * free, the remainder of the region must be split into blocks.   
 407 * If a block is freed, and its buddy is also free, then this
 408 * triggers coalescing into a block of larger size.            
 409 *
 410 * -- wli
 411 */
 412
 413static inline void __free_one_page(struct page *page,
 414                struct zone *zone, unsigned int order)
 415{
 416        unsigned long page_idx;
 417        int order_size = 1 << order;
 418        int migratetype = get_pageblock_migratetype(page);
 419
 420        if (unlikely(PageCompound(page)))
 421                destroy_compound_page(page, order);
 422
 423        page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
 424
 425        VM_BUG_ON(page_idx & (order_size - 1));
 426        VM_BUG_ON(bad_range(zone, page));
 427
 428        __mod_zone_page_state(zone, NR_FREE_PAGES, order_size);
 429        while (order < MAX_ORDER-1) {
 430                unsigned long combined_idx;
 431                struct page *buddy;
 432
 433                buddy = __page_find_buddy(page, page_idx, order);
 434                if (!page_is_buddy(page, buddy, order))
 435                        break;          /* Move the buddy up one level. */
 436
 437                list_del(&buddy->lru);
 438                zone->free_area[order].nr_free--;
 439                rmv_page_order(buddy);
 440                combined_idx = __find_combined_index(page_idx, order);
 441                page = page + (combined_idx - page_idx);
 442                page_idx = combined_idx;
 443                order++;
 444        }
 445        set_page_order(page, order);
 446        list_add(&page->lru,
 447                &zone->free_area[order].free_list[migratetype]);
 448        zone->free_area[order].nr_free++;
 449}
 450
 451static inline int free_pages_check(struct page *page)
 452{
 453        if (unlikely(page_mapcount(page) |
 454                (page->mapping != NULL)  |
 455                (page_get_page_cgroup(page) != NULL) |
 456                (page_count(page) != 0)  |
 457                (page->flags & PAGE_FLAGS_CHECK_AT_FREE)))
 458                bad_page(page);
 459        if (PageDirty(page))
 460                __ClearPageDirty(page);
 461        /*
 462         * For now, we report if PG_reserved was found set, but do not
 463         * clear it, and do not free the page.  But we shall soon need
 464         * to do more, for when the ZERO_PAGE count wraps negative.
 465         */
 466        return PageReserved(page);
 467}
 468
 469/*
 470 * Frees a list of pages. 
 471 * Assumes all pages on list are in same zone, and of same order.
 472 * count is the number of pages to free.
 473 *
 474 * If the zone was previously in an "all pages pinned" state then look to
 475 * see if this freeing clears that state.
 476 *
 477 * And clear the zone's pages_scanned counter, to hold off the "all pages are
 478 * pinned" detection logic.
 479 */
 480static void free_pages_bulk(struct zone *zone, int count,
 481                                        struct list_head *list, int order)
 482{
 483        spin_lock(&zone->lock);
 484        zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
 485        zone->pages_scanned = 0;
 486        while (count--) {
 487                struct page *page;
 488
 489                VM_BUG_ON(list_empty(list));
 490                page = list_entry(list->prev, struct page, lru);
 491                /* have to delete it as __free_one_page list manipulates */
 492                list_del(&page->lru);
 493                __free_one_page(page, zone, order);
 494        }
 495        spin_unlock(&zone->lock);
 496}
 497
 498static void free_one_page(struct zone *zone, struct page *page, int order)
 499{
 500        spin_lock(&zone->lock);
 501        zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
 502        zone->pages_scanned = 0;
 503        __free_one_page(page, zone, order);
 504        spin_unlock(&zone->lock);
 505}
 506
 507static void __free_pages_ok(struct page *page, unsigned int order)
 508{
 509        unsigned long flags;
 510        int i;
 511        int reserved = 0;
 512
 513        for (i = 0 ; i < (1 << order) ; ++i)
 514                reserved += free_pages_check(page + i);
 515        if (reserved)
 516                return;
 517
 518        if (!PageHighMem(page)) {
 519                debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
 520                debug_check_no_obj_freed(page_address(page),
 521                                           PAGE_SIZE << order);
 522        }
 523        arch_free_page(page, order);
 524        kernel_map_pages(page, 1 << order, 0);
 525
 526        local_irq_save(flags);
 527        __count_vm_events(PGFREE, 1 << order);
 528        free_one_page(page_zone(page), page, order);
 529        local_irq_restore(flags);
 530}
 531
 532/*
 533 * permit the bootmem allocator to evade page validation on high-order frees
 534 */
 535void __free_pages_bootmem(struct page *page, unsigned int order)
 536{
 537        if (order == 0) {
 538                __ClearPageReserved(page);
 539                set_page_count(page, 0);
 540                set_page_refcounted(page);
 541                __free_page(page);
 542        } else {
 543                int loop;
 544
 545                prefetchw(page);
 546                for (loop = 0; loop < BITS_PER_LONG; loop++) {
 547                        struct page *p = &page[loop];
 548
 549                        if (loop + 1 < BITS_PER_LONG)
 550                                prefetchw(p + 1);
 551                        __ClearPageReserved(p);
 552                        set_page_count(p, 0);
 553                }
 554
 555                set_page_refcounted(page);
 556                __free_pages(page, order);
 557        }
 558}
 559
 560
 561/*
 562 * The order of subdivision here is critical for the IO subsystem.
 563 * Please do not alter this order without good reasons and regression
 564 * testing. Specifically, as large blocks of memory are subdivided,
 565 * the order in which smaller blocks are delivered depends on the order
 566 * they're subdivided in this function. This is the primary factor
 567 * influencing the order in which pages are delivered to the IO
 568 * subsystem according to empirical testing, and this is also justified
 569 * by considering the behavior of a buddy system containing a single
 570 * large block of memory acted on by a series of small allocations.
 571 * This behavior is a critical factor in sglist merging's success.
 572 *
 573 * -- wli
 574 */
 575static inline void expand(struct zone *zone, struct page *page,
 576        int low, int high, struct free_area *area,
 577        int migratetype)
 578{
 579        unsigned long size = 1 << high;
 580
 581        while (high > low) {
 582                area--;
 583                high--;
 584                size >>= 1;
 585                VM_BUG_ON(bad_range(zone, &page[size]));
 586                list_add(&page[size].lru, &area->free_list[migratetype]);
 587                area->nr_free++;
 588                set_page_order(&page[size], high);
 589        }
 590}
 591
 592/*
 593 * This page is about to be returned from the page allocator
 594 */
 595static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
 596{
 597        if (unlikely(page_mapcount(page) |
 598                (page->mapping != NULL)  |
 599                (page_get_page_cgroup(page) != NULL) |
 600                (page_count(page) != 0)  |
 601                (page->flags & PAGE_FLAGS_CHECK_AT_PREP)))
 602                bad_page(page);
 603
 604        /*
 605         * For now, we report if PG_reserved was found set, but do not
 606         * clear it, and do not allocate the page: as a safety net.
 607         */
 608        if (PageReserved(page))
 609                return 1;
 610
 611        page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_reclaim |
 612                        1 << PG_referenced | 1 << PG_arch_1 |
 613                        1 << PG_owner_priv_1 | 1 << PG_mappedtodisk);
 614        set_page_private(page, 0);
 615        set_page_refcounted(page);
 616
 617        arch_alloc_page(page, order);
 618        kernel_map_pages(page, 1 << order, 1);
 619
 620        if (gfp_flags & __GFP_ZERO)
 621                prep_zero_page(page, order, gfp_flags);
 622
 623        if (order && (gfp_flags & __GFP_COMP))
 624                prep_compound_page(page, order);
 625
 626        return 0;
 627}
 628
 629/*
 630 * Go through the free lists for the given migratetype and remove
 631 * the smallest available page from the freelists
 632 */
 633static struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
 634                                                int migratetype)
 635{
 636        unsigned int current_order;
 637        struct free_area * area;
 638        struct page *page;
 639
 640        /* Find a page of the appropriate size in the preferred list */
 641        for (current_order = order; current_order < MAX_ORDER; ++current_order) {
 642                area = &(zone->free_area[current_order]);
 643                if (list_empty(&area->free_list[migratetype]))
 644                        continue;
 645
 646                page = list_entry(area->free_list[migratetype].next,
 647                                                        struct page, lru);
 648                list_del(&page->lru);
 649                rmv_page_order(page);
 650                area->nr_free--;
 651                __mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order));
 652                expand(zone, page, order, current_order, area, migratetype);
 653                return page;
 654        }
 655
 656        return NULL;
 657}
 658
 659
 660/*
 661 * This array describes the order lists are fallen back to when
 662 * the free lists for the desirable migrate type are depleted
 663 */
 664static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
 665        [MIGRATE_UNMOVABLE]   = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE,   MIGRATE_RESERVE },
 666        [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE,   MIGRATE_MOVABLE,   MIGRATE_RESERVE },
 667        [MIGRATE_MOVABLE]     = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
 668        [MIGRATE_RESERVE]     = { MIGRATE_RESERVE,     MIGRATE_RESERVE,   MIGRATE_RESERVE }, /* Never used */
 669};
 670
 671/*
 672 * Move the free pages in a range to the free lists of the requested type.
 673 * Note that start_page and end_pages are not aligned on a pageblock
 674 * boundary. If alignment is required, use move_freepages_block()
 675 */
 676int move_freepages(struct zone *zone,
 677                        struct page *start_page, struct page *end_page,
 678                        int migratetype)
 679{
 680        struct page *page;
 681        unsigned long order;
 682        int pages_moved = 0;
 683
 684#ifndef CONFIG_HOLES_IN_ZONE
 685        /*
 686         * page_zone is not safe to call in this context when
 687         * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
 688         * anyway as we check zone boundaries in move_freepages_block().
 689         * Remove at a later date when no bug reports exist related to
 690         * grouping pages by mobility
 691         */
 692        BUG_ON(page_zone(start_page) != page_zone(end_page));
 693#endif
 694
 695        for (page = start_page; page <= end_page;) {
 696                /* Make sure we are not inadvertently changing nodes */
 697                VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));
 698
 699                if (!pfn_valid_within(page_to_pfn(page))) {
 700                        page++;
 701                        continue;
 702                }
 703
 704                if (!PageBuddy(page)) {
 705                        page++;
 706                        continue;
 707                }
 708
 709                order = page_order(page);
 710                list_del(&page->lru);
 711                list_add(&page->lru,
 712                        &zone->free_area[order].free_list[migratetype]);
 713                page += 1 << order;
 714                pages_moved += 1 << order;
 715        }
 716
 717        return pages_moved;
 718}
 719
 720int move_freepages_block(struct zone *zone, struct page *page, int migratetype)
 721{
 722        unsigned long start_pfn, end_pfn;
 723        struct page *start_page, *end_page;
 724
 725        start_pfn = page_to_pfn(page);
 726        start_pfn = start_pfn & ~(pageblock_nr_pages-1);
 727        start_page = pfn_to_page(start_pfn);
 728        end_page = start_page + pageblock_nr_pages - 1;
 729        end_pfn = start_pfn + pageblock_nr_pages - 1;
 730
 731        /* Do not cross zone boundaries */
 732        if (start_pfn < zone->zone_start_pfn)
 733                start_page = page;
 734        if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages)
 735                return 0;
 736
 737        return move_freepages(zone, start_page, end_page, migratetype);
 738}
 739
 740/* Remove an element from the buddy allocator from the fallback list */
 741static struct page *__rmqueue_fallback(struct zone *zone, int order,
 742                                                int start_migratetype)
 743{
 744        struct free_area * area;
 745        int current_order;
 746        struct page *page;
 747        int migratetype, i;
 748
 749        /* Find the largest possible block of pages in the other list */
 750        for (current_order = MAX_ORDER-1; current_order >= order;
 751                                                --current_order) {
 752                for (i = 0; i < MIGRATE_TYPES - 1; i++) {
 753                        migratetype = fallbacks[start_migratetype][i];
 754
 755                        /* MIGRATE_RESERVE handled later if necessary */
 756                        if (migratetype == MIGRATE_RESERVE)
 757                                continue;
 758
 759                        area = &(zone->free_area[current_order]);
 760                        if (list_empty(&area->free_list[migratetype]))
 761                                continue;
 762
 763                        page = list_entry(area->free_list[migratetype].next,
 764                                        struct page, lru);
 765                        area->nr_free--;
 766
 767                        /*
 768                         * If breaking a large block of pages, move all free
 769                         * pages to the preferred allocation list. If falling
 770                         * back for a reclaimable kernel allocation, be more
 771                         * agressive about taking ownership of free pages
 772                         */
 773                        if (unlikely(current_order >= (pageblock_order >> 1)) ||
 774                                        start_migratetype == MIGRATE_RECLAIMABLE) {
 775                                unsigned long pages;
 776                                pages = move_freepages_block(zone, page,
 777                                                                start_migratetype);
 778
 779                                /* Claim the whole block if over half of it is free */
 780                                if (pages >= (1 << (pageblock_order-1)))
 781                                        set_pageblock_migratetype(page,
 782                                                                start_migratetype);
 783
 784                                migratetype = start_migratetype;
 785                        }
 786
 787                        /* Remove the page from the freelists */
 788                        list_del(&page->lru);
 789                        rmv_page_order(page);
 790                        __mod_zone_page_state(zone, NR_FREE_PAGES,
 791                                                        -(1UL << order));
 792
 793                        if (current_order == pageblock_order)
 794                                set_pageblock_migratetype(page,
 795                                                        start_migratetype);
 796
 797                        expand(zone, page, order, current_order, area, migratetype);
 798                        return page;
 799                }
 800        }
 801
 802        /* Use MIGRATE_RESERVE rather than fail an allocation */
 803        return __rmqueue_smallest(zone, order, MIGRATE_RESERVE);
 804}
 805
 806/*
 807 * Do the hard work of removing an element from the buddy allocator.
 808 * Call me with the zone->lock already held.
 809 */
 810static struct page *__rmqueue(struct zone *zone, unsigned int order,
 811                                                int migratetype)
 812{
 813        struct page *page;
 814
 815        page = __rmqueue_smallest(zone, order, migratetype);
 816
 817        if (unlikely(!page))
 818                page = __rmqueue_fallback(zone, order, migratetype);
 819
 820        return page;
 821}
 822
 823/* 
 824 * Obtain a specified number of elements from the buddy allocator, all under
 825 * a single hold of the lock, for efficiency.  Add them to the supplied list.
 826 * Returns the number of new pages which were placed at *list.
 827 */
 828static int rmqueue_bulk(struct zone *zone, unsigned int order, 
 829                        unsigned long count, struct list_head *list,
 830                        int migratetype)
 831{
 832        int i;
 833        
 834        spin_lock(&zone->lock);
 835        for (i = 0; i < count; ++i) {
 836                struct page *page = __rmqueue(zone, order, migratetype);
 837                if (unlikely(page == NULL))
 838                        break;
 839
 840                /*
 841                 * Split buddy pages returned by expand() are received here
 842                 * in physical page order. The page is added to the callers and
 843                 * list and the list head then moves forward. From the callers
 844                 * perspective, the linked list is ordered by page number in
 845                 * some conditions. This is useful for IO devices that can
 846                 * merge IO requests if the physical pages are ordered
 847                 * properly.
 848                 */
 849                list_add(&page->lru, list);
 850                set_page_private(page, migratetype);
 851                list = &page->lru;
 852        }
 853        spin_unlock(&zone->lock);
 854        return i;
 855}
 856
 857#ifdef CONFIG_NUMA
 858/*
 859 * Called from the vmstat counter updater to drain pagesets of this
 860 * currently executing processor on remote nodes after they have
 861 * expired.
 862 *
 863 * Note that this function must be called with the thread pinned to
 864 * a single processor.
 865 */
 866void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
 867{
 868        unsigned long flags;
 869        int to_drain;
 870
 871        local_irq_save(flags);
 872        if (pcp->count >= pcp->batch)
 873                to_drain = pcp->batch;
 874        else
 875                to_drain = pcp->count;
 876        free_pages_bulk(zone, to_drain, &pcp->list, 0);
 877        pcp->count -= to_drain;
 878        local_irq_restore(flags);
 879}
 880#endif
 881
 882/*
 883 * Drain pages of the indicated processor.
 884 *
 885 * The processor must either be the current processor and the
 886 * thread pinned to the current processor or a processor that
 887 * is not online.
 888 */
 889static void drain_pages(unsigned int cpu)
 890{
 891        unsigned long flags;
 892        struct zone *zone;
 893
 894        for_each_zone(zone) {
 895                struct per_cpu_pageset *pset;
 896                struct per_cpu_pages *pcp;
 897
 898                if (!populated_zone(zone))
 899                        continue;
 900
 901                pset = zone_pcp(zone, cpu);
 902
 903                pcp = &pset->pcp;
 904                local_irq_save(flags);
 905                free_pages_bulk(zone, pcp->count, &pcp->list, 0);
 906                pcp->count = 0;
 907                local_irq_restore(flags);
 908        }
 909}
 910
 911/*
 912 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
 913 */
 914void drain_local_pages(void *arg)
 915{
 916        drain_pages(smp_processor_id());
 917}
 918
 919/*
 920 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
 921 */
 922void drain_all_pages(void)
 923{
 924        on_each_cpu(drain_local_pages, NULL, 0, 1);
 925}
 926
 927#ifdef CONFIG_HIBERNATION
 928
 929void mark_free_pages(struct zone *zone)
 930{
 931        unsigned long pfn, max_zone_pfn;
 932        unsigned long flags;
 933        int order, t;
 934        struct list_head *curr;
 935
 936        if (!zone->spanned_pages)
 937                return;
 938
 939        spin_lock_irqsave(&zone->lock, flags);
 940
 941        max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
 942        for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
 943                if (pfn_valid(pfn)) {
 944                        struct page *page = pfn_to_page(pfn);
 945
 946                        if (!swsusp_page_is_forbidden(page))
 947                                swsusp_unset_page_free(page);
 948                }
 949
 950        for_each_migratetype_order(order, t) {
 951                list_for_each(curr, &zone->free_area[order].free_list[t]) {
 952                        unsigned long i;
 953
 954                        pfn = page_to_pfn(list_entry(curr, struct page, lru));
 955                        for (i = 0; i < (1UL << order); i++)
 956                                swsusp_set_page_free(pfn_to_page(pfn + i));
 957                }
 958        }
 959        spin_unlock_irqrestore(&zone->lock, flags);
 960}
 961#endif /* CONFIG_PM */
 962
 963/*
 964 * Free a 0-order page
 965 */
 966static void free_hot_cold_page(struct page *page, int cold)
 967{
 968        struct zone *zone = page_zone(page);
 969        struct per_cpu_pages *pcp;
 970        unsigned long flags;
 971
 972        if (PageAnon(page))
 973                page->mapping = NULL;
 974        if (free_pages_check(page))
 975                return;
 976
 977        if (!PageHighMem(page)) {
 978                debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
 979                debug_check_no_obj_freed(page_address(page), PAGE_SIZE);
 980        }
 981        arch_free_page(page, 0);
 982        kernel_map_pages(page, 1, 0);
 983
 984        pcp = &zone_pcp(zone, get_cpu())->pcp;
 985        local_irq_save(flags);
 986        __count_vm_event(PGFREE);
 987        if (cold)
 988                list_add_tail(&page->lru, &pcp->list);
 989        else
 990                list_add(&page->lru, &pcp->list);
 991        set_page_private(page, get_pageblock_migratetype(page));
 992        pcp->count++;
 993        if (pcp->count >= pcp->high) {
 994                free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
 995                pcp->count -= pcp->batch;
 996        }
 997        local_irq_restore(flags);
 998        put_cpu();
 999}
1000
1001void free_hot_page(struct page *page)
1002{
1003        free_hot_cold_page(page, 0);
1004}
1005        
1006void free_cold_page(struct page *page)
1007{
1008        free_hot_cold_page(page, 1);
1009}
1010
1011/*
1012 * split_page takes a non-compound higher-order page, and splits it into
1013 * n (1<<order) sub-pages: page[0..n]
1014 * Each sub-page must be freed individually.
1015 *
1016 * Note: this is probably too low level an operation for use in drivers.
1017 * Please consult with lkml before using this in your driver.
1018 */
1019void split_page(struct page *page, unsigned int order)
1020{
1021        int i;
1022
1023        VM_BUG_ON(PageCompound(page));
1024        VM_BUG_ON(!page_count(page));
1025        for (i = 1; i < (1 << order); i++)
1026                set_page_refcounted(page + i);
1027}
1028
1029/*
1030 * Really, prep_compound_page() should be called from __rmqueue_bulk().  But
1031 * we cheat by calling it from here, in the order > 0 path.  Saves a branch
1032 * or two.
1033 */
1034static struct page *buffered_rmqueue(struct zone *preferred_zone,
1035                        struct zone *zone, int order, gfp_t gfp_flags)
1036{
1037        unsigned long flags;
1038        struct page *page;
1039        int cold = !!(gfp_flags & __GFP_COLD);
1040        int cpu;
1041        int migratetype = allocflags_to_migratetype(gfp_flags);
1042
1043again:
1044        cpu  = get_cpu();
1045        if (likely(order == 0)) {
1046                struct per_cpu_pages *pcp;
1047
1048                pcp = &zone_pcp(zone, cpu)->pcp;
1049                local_irq_save(flags);
1050                if (!pcp->count) {
1051                        pcp->count = rmqueue_bulk(zone, 0,
1052                                        pcp->batch, &pcp->list, migratetype);
1053                        if (unlikely(!pcp->count))
1054                                goto failed;
1055                }
1056
1057                /* Find a page of the appropriate migrate type */
1058                if (cold) {
1059                        list_for_each_entry_reverse(page, &pcp->list, lru)
1060                                if (page_private(page) == migratetype)
1061                                        break;
1062                } else {
1063                        list_for_each_entry(page, &pcp->list, lru)
1064                                if (page_private(page) == migratetype)
1065                                        break;
1066                }
1067
1068                /* Allocate more to the pcp list if necessary */
1069                if (unlikely(&page->lru == &pcp->list)) {
1070                        pcp->count += rmqueue_bulk(zone, 0,
1071                                        pcp->batch, &pcp->list, migratetype);
1072                        page = list_entry(pcp->list.next, struct page, lru);
1073                }
1074
1075                list_del(&page->lru);
1076                pcp->count--;
1077        } else {
1078                spin_lock_irqsave(&zone->lock, flags);
1079                page = __rmqueue(zone, order, migratetype);
1080                spin_unlock(&zone->lock);
1081                if (!page)
1082                        goto failed;
1083        }
1084
1085        __count_zone_vm_events(PGALLOC, zone, 1 << order);
1086        zone_statistics(preferred_zone, zone);
1087        local_irq_restore(flags);
1088        put_cpu();
1089
1090        VM_BUG_ON(bad_range(zone, page));
1091        if (prep_new_page(page, order, gfp_flags))
1092                goto again;
1093        return page;
1094
1095failed:
1096        local_irq_restore(flags);
1097        put_cpu();
1098        return NULL;
1099}
1100
1101#define ALLOC_NO_WATERMARKS     0x01 /* don't check watermarks at all */
1102#define ALLOC_WMARK_MIN         0x02 /* use pages_min watermark */
1103#define ALLOC_WMARK_LOW         0x04 /* use pages_low watermark */
1104#define ALLOC_WMARK_HIGH        0x08 /* use pages_high watermark */
1105#define ALLOC_HARDER            0x10 /* try to alloc harder */
1106#define ALLOC_HIGH              0x20 /* __GFP_HIGH set */
1107#define ALLOC_CPUSET            0x40 /* check for correct cpuset */
1108
1109#ifdef CONFIG_FAIL_PAGE_ALLOC
1110
1111static struct fail_page_alloc_attr {
1112        struct fault_attr attr;
1113
1114        u32 ignore_gfp_highmem;
1115        u32 ignore_gfp_wait;
1116        u32 min_order;
1117
1118#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1119
1120        struct dentry *ignore_gfp_highmem_file;
1121        struct dentry *ignore_gfp_wait_file;
1122        struct dentry *min_order_file;
1123
1124#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1125
1126} fail_page_alloc = {
1127        .attr = FAULT_ATTR_INITIALIZER,
1128        .ignore_gfp_wait = 1,
1129        .ignore_gfp_highmem = 1,
1130        .min_order = 1,
1131};
1132
1133static int __init setup_fail_page_alloc(char *str)
1134{
1135        return setup_fault_attr(&fail_page_alloc.attr, str);
1136}
1137__setup("fail_page_alloc=", setup_fail_page_alloc);
1138
1139static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1140{
1141        if (order < fail_page_alloc.min_order)
1142                return 0;
1143        if (gfp_mask & __GFP_NOFAIL)
1144                return 0;
1145        if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1146                return 0;
1147        if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1148                return 0;
1149
1150        return should_fail(&fail_page_alloc.attr, 1 << order);
1151}
1152
1153#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
1154
1155static int __init fail_page_alloc_debugfs(void)
1156{
1157        mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1158        struct dentry *dir;
1159        int err;
1160
1161        err = init_fault_attr_dentries(&fail_page_alloc.attr,
1162                                       "fail_page_alloc");
1163        if (err)
1164                return err;
1165        dir = fail_page_alloc.attr.dentries.dir;
1166
1167        fail_page_alloc.ignore_gfp_wait_file =
1168                debugfs_create_bool("ignore-gfp-wait", mode, dir,
1169                                      &fail_page_alloc.ignore_gfp_wait);
1170
1171        fail_page_alloc.ignore_gfp_highmem_file =
1172                debugfs_create_bool("ignore-gfp-highmem", mode, dir,
1173                                      &fail_page_alloc.ignore_gfp_highmem);
1174        fail_page_alloc.min_order_file =
1175                debugfs_create_u32("min-order", mode, dir,
1176                                   &fail_page_alloc.min_order);
1177
1178        if (!fail_page_alloc.ignore_gfp_wait_file ||
1179            !fail_page_alloc.ignore_gfp_highmem_file ||
1180            !fail_page_alloc.min_order_file) {
1181                err = -ENOMEM;
1182                debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
1183                debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1184                debugfs_remove(fail_page_alloc.min_order_file);
1185                cleanup_fault_attr_dentries(&fail_page_alloc.attr);
1186        }
1187
1188        return err;
1189}
1190
1191late_initcall(fail_page_alloc_debugfs);
1192
1193#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
1194
1195#else /* CONFIG_FAIL_PAGE_ALLOC */
1196
1197static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1198{
1199        return 0;
1200}
1201
1202#endif /* CONFIG_FAIL_PAGE_ALLOC */
1203
1204/*
1205 * Return 1 if free pages are above 'mark'. This takes into account the order
1206 * of the allocation.
1207 */
1208int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
1209                      int classzone_idx, int alloc_flags)
1210{
1211        /* free_pages my go negative - that's OK */
1212        long min = mark;
1213        long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
1214        int o;
1215
1216        if (alloc_flags & ALLOC_HIGH)
1217                min -= min / 2;
1218        if (alloc_flags & ALLOC_HARDER)
1219                min -= min / 4;
1220
1221        if (free_pages <= min + z->lowmem_reserve[classzone_idx])
1222                return 0;
1223        for (o = 0; o < order; o++) {
1224                /* At the next order, this order's pages become unavailable */
1225                free_pages -= z->free_area[o].nr_free << o;
1226
1227                /* Require fewer higher order pages to be free */
1228                min >>= 1;
1229
1230                if (free_pages <= min)
1231                        return 0;
1232        }
1233        return 1;
1234}
1235
1236#ifdef CONFIG_NUMA
1237/*
1238 * zlc_setup - Setup for "zonelist cache".  Uses cached zone data to
1239 * skip over zones that are not allowed by the cpuset, or that have
1240 * been recently (in last second) found to be nearly full.  See further
1241 * comments in mmzone.h.  Reduces cache footprint of zonelist scans
1242 * that have to skip over a lot of full or unallowed zones.
1243 *
1244 * If the zonelist cache is present in the passed in zonelist, then
1245 * returns a pointer to the allowed node mask (either the current
1246 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1247 *
1248 * If the zonelist cache is not available for this zonelist, does
1249 * nothing and returns NULL.
1250 *
1251 * If the fullzones BITMAP in the zonelist cache is stale (more than
1252 * a second since last zap'd) then we zap it out (clear its bits.)
1253 *
1254 * We hold off even calling zlc_setup, until after we've checked the
1255 * first zone in the zonelist, on the theory that most allocations will
1256 * be satisfied from that first zone, so best to examine that zone as
1257 * quickly as we can.
1258 */
1259static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1260{
1261        struct zonelist_cache *zlc;     /* cached zonelist speedup info */
1262        nodemask_t *allowednodes;       /* zonelist_cache approximation */
1263
1264        zlc = zonelist->zlcache_ptr;
1265        if (!zlc)
1266                return NULL;
1267
1268        if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1269                bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
1270                zlc->last_full_zap = jiffies;
1271        }
1272
1273        allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
1274                                        &cpuset_current_mems_allowed :
1275                                        &node_states[N_HIGH_MEMORY];
1276        return allowednodes;
1277}
1278
1279/*
1280 * Given 'z' scanning a zonelist, run a couple of quick checks to see
1281 * if it is worth looking at further for free memory:
1282 *  1) Check that the zone isn't thought to be full (doesn't have its
1283 *     bit set in the zonelist_cache fullzones BITMAP).
1284 *  2) Check that the zones node (obtained from the zonelist_cache
1285 *     z_to_n[] mapping) is allowed in the passed in allowednodes mask.
1286 * Return true (non-zero) if zone is worth looking at further, or
1287 * else return false (zero) if it is not.
1288 *
1289 * This check -ignores- the distinction between various watermarks,
1290 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ...  If a zone is
1291 * found to be full for any variation of these watermarks, it will
1292 * be considered full for up to one second by all requests, unless
1293 * we are so low on memory on all allowed nodes that we are forced
1294 * into the second scan of the zonelist.
1295 *
1296 * In the second scan we ignore this zonelist cache and exactly
1297 * apply the watermarks to all zones, even it is slower to do so.
1298 * We are low on memory in the second scan, and should leave no stone
1299 * unturned looking for a free page.
1300 */
1301static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1302                                                nodemask_t *allowednodes)
1303{
1304        struct zonelist_cache *zlc;     /* cached zonelist speedup info */
1305        int i;                          /* index of *z in zonelist zones */
1306        int n;                          /* node that zone *z is on */
1307
1308        zlc = zonelist->zlcache_ptr;
1309        if (!zlc)
1310                return 1;
1311
1312        i = z - zonelist->_zonerefs;
1313        n = zlc->z_to_n[i];
1314
1315        /* This zone is worth trying if it is allowed but not full */
1316        return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
1317}
1318
1319/*
1320 * Given 'z' scanning a zonelist, set the corresponding bit in
1321 * zlc->fullzones, so that subsequent attempts to allocate a page
1322 * from that zone don't waste time re-examining it.
1323 */
1324static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1325{
1326        struct zonelist_cache *zlc;     /* cached zonelist speedup info */
1327        int i;                          /* index of *z in zonelist zones */
1328
1329        zlc = zonelist->zlcache_ptr;
1330        if (!zlc)
1331                return;
1332
1333        i = z - zonelist->_zonerefs;
1334
1335        set_bit(i, zlc->fullzones);
1336}
1337
1338#else   /* CONFIG_NUMA */
1339
1340static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
1341{
1342        return NULL;
1343}
1344
1345static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1346                                nodemask_t *allowednodes)
1347{
1348        return 1;
1349}
1350
1351static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1352{
1353}
1354#endif  /* CONFIG_NUMA */
1355
1356/*
1357 * get_page_from_freelist goes through the zonelist trying to allocate
1358 * a page.
1359 */
1360static struct page *
1361get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1362                struct zonelist *zonelist, int high_zoneidx, int alloc_flags)
1363{
1364        struct zoneref *z;
1365        struct page *page = NULL;
1366        int classzone_idx;
1367        struct zone *zone, *preferred_zone;
1368        nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
1369        int zlc_active = 0;             /* set if using zonelist_cache */
1370        int did_zlc_setup = 0;          /* just call zlc_setup() one time */
1371
1372        (void)first_zones_zonelist(zonelist, high_zoneidx, nodemask,
1373                                                        &preferred_zone);
1374        if (!preferred_zone)
1375                return NULL;
1376
1377        classzone_idx = zone_idx(preferred_zone);
1378
1379zonelist_scan:
1380        /*
1381         * Scan zonelist, looking for a zone with enough free.
1382         * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1383         */
1384        for_each_zone_zonelist_nodemask(zone, z, zonelist,
1385                                                high_zoneidx, nodemask) {
1386                if (NUMA_BUILD && zlc_active &&
1387                        !zlc_zone_worth_trying(zonelist, z, allowednodes))
1388                                continue;
1389                if ((alloc_flags & ALLOC_CPUSET) &&
1390                        !cpuset_zone_allowed_softwall(zone, gfp_mask))
1391                                goto try_next_zone;
1392
1393                if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1394                        unsigned long mark;
1395                        if (alloc_flags & ALLOC_WMARK_MIN)
1396                                mark = zone->pages_min;
1397                        else if (alloc_flags & ALLOC_WMARK_LOW)
1398                                mark = zone->pages_low;
1399                        else
1400                                mark = zone->pages_high;
1401                        if (!zone_watermark_ok(zone, order, mark,
1402                                    classzone_idx, alloc_flags)) {
1403                                if (!zone_reclaim_mode ||
1404                                    !zone_reclaim(zone, gfp_mask, order))
1405                                        goto this_zone_full;
1406                        }
1407                }
1408
1409                page = buffered_rmqueue(preferred_zone, zone, order, gfp_mask);
1410                if (page)
1411                        break;
1412this_zone_full:
1413                if (NUMA_BUILD)
1414                        zlc_mark_zone_full(zonelist, z);
1415try_next_zone:
1416                if (NUMA_BUILD && !did_zlc_setup) {
1417                        /* we do zlc_setup after the first zone is tried */
1418                        allowednodes = zlc_setup(zonelist, alloc_flags);
1419                        zlc_active = 1;
1420                        did_zlc_setup = 1;
1421                }
1422        }
1423
1424        if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
1425                /* Disable zlc cache for second zonelist scan */
1426                zlc_active = 0;
1427                goto zonelist_scan;
1428        }
1429        return page;
1430}
1431
1432/*
1433 * This is the 'heart' of the zoned buddy allocator.
1434 */
1435static struct page *
1436__alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
1437                        struct zonelist *zonelist, nodemask_t *nodemask)
1438{
1439        const gfp_t wait = gfp_mask & __GFP_WAIT;
1440        enum zone_type high_zoneidx = gfp_zone(gfp_mask);
1441        struct zoneref *z;
1442        struct zone *zone;
1443        struct page *page;
1444        struct reclaim_state reclaim_state;
1445        struct task_struct *p = current;
1446        int do_retry;
1447        int alloc_flags;
1448        unsigned long did_some_progress;
1449        unsigned long pages_reclaimed = 0;
1450
1451        might_sleep_if(wait);
1452
1453        if (should_fail_alloc_page(gfp_mask, order))
1454                return NULL;
1455
1456restart:
1457        z = zonelist->_zonerefs;  /* the list of zones suitable for gfp_mask */
1458
1459        if (unlikely(!z->zone)) {
1460                /*
1461                 * Happens if we have an empty zonelist as a result of
1462                 * GFP_THISNODE being used on a memoryless node
1463                 */
1464                return NULL;
1465        }
1466
1467        page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
1468                        zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET);
1469        if (page)
1470                goto got_pg;
1471
1472        /*
1473         * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
1474         * __GFP_NOWARN set) should not cause reclaim since the subsystem
1475         * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
1476         * using a larger set of nodes after it has established that the
1477         * allowed per node queues are empty and that nodes are
1478         * over allocated.
1479         */
1480        if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
1481                goto nopage;
1482
1483        for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
1484                wakeup_kswapd(zone, order);
1485
1486        /*
1487         * OK, we're below the kswapd watermark and have kicked background
1488         * reclaim. Now things get more complex, so set up alloc_flags according
1489         * to how we want to proceed.
1490         *
1491         * The caller may dip into page reserves a bit more if the caller
1492         * cannot run direct reclaim, or if the caller has realtime scheduling
1493         * policy or is asking for __GFP_HIGH memory.  GFP_ATOMIC requests will
1494         * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1495         */
1496        alloc_flags = ALLOC_WMARK_MIN;
1497        if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)
1498                alloc_flags |= ALLOC_HARDER;
1499        if (gfp_mask & __GFP_HIGH)
1500                alloc_flags |= ALLOC_HIGH;
1501        if (wait)
1502                alloc_flags |= ALLOC_CPUSET;
1503
1504        /*
1505         * Go through the zonelist again. Let __GFP_HIGH and allocations
1506         * coming from realtime tasks go deeper into reserves.
1507         *
1508         * This is the last chance, in general, before the goto nopage.
1509         * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1510         * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1511         */
1512        page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1513                                                high_zoneidx, alloc_flags);
1514        if (page)
1515                goto got_pg;
1516
1517        /* This allocation should allow future memory freeing. */
1518
1519rebalance:
1520        if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
1521                        && !in_interrupt()) {
1522                if (!(gfp_mask & __GFP_NOMEMALLOC)) {
1523nofail_alloc:
1524                        /* go through the zonelist yet again, ignoring mins */
1525                        page = get_page_from_freelist(gfp_mask, nodemask, order,
1526                                zonelist, high_zoneidx, ALLOC_NO_WATERMARKS);
1527                        if (page)
1528                                goto got_pg;
1529                        if (gfp_mask & __GFP_NOFAIL) {
1530                                congestion_wait(WRITE, HZ/50);
1531                                goto nofail_alloc;
1532                        }
1533                }
1534                goto nopage;
1535        }
1536
1537        /* Atomic allocations - we can't balance anything */
1538        if (!wait)
1539                goto nopage;
1540
1541        cond_resched();
1542
1543        /* We now go into synchronous reclaim */
1544        cpuset_memory_pressure_bump();
1545        p->flags |= PF_MEMALLOC;
1546        reclaim_state.reclaimed_slab = 0;
1547        p->reclaim_state = &reclaim_state;
1548
1549        did_some_progress = try_to_free_pages(zonelist, order, gfp_mask);
1550
1551        p->reclaim_state = NULL;
1552        p->flags &= ~PF_MEMALLOC;
1553
1554        cond_resched();
1555
1556        if (order != 0)
1557                drain_all_pages();
1558
1559        if (likely(did_some_progress)) {
1560                page = get_page_from_freelist(gfp_mask, nodemask, order,
1561                                        zonelist, high_zoneidx, alloc_flags);
1562                if (page)
1563                        goto got_pg;
1564        } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1565                if (!try_set_zone_oom(zonelist, gfp_mask)) {
1566                        schedule_timeout_uninterruptible(1);
1567                        goto restart;
1568                }
1569
1570                /*
1571                 * Go through the zonelist yet one more time, keep
1572                 * very high watermark here, this is only to catch
1573                 * a parallel oom killing, we must fail if we're still
1574                 * under heavy pressure.
1575                 */
1576                page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
1577                        order, zonelist, high_zoneidx,
1578                        ALLOC_WMARK_HIGH|ALLOC_CPUSET);
1579                if (page) {
1580                        clear_zonelist_oom(zonelist, gfp_mask);
1581                        goto got_pg;
1582                }
1583
1584                /* The OOM killer will not help higher order allocs so fail */
1585                if (order > PAGE_ALLOC_COSTLY_ORDER) {
1586                        clear_zonelist_oom(zonelist, gfp_mask);
1587                        goto nopage;
1588                }
1589
1590                out_of_memory(zonelist, gfp_mask, order);
1591                clear_zonelist_oom(zonelist, gfp_mask);
1592                goto restart;
1593        }
1594
1595        /*
1596         * Don't let big-order allocations loop unless the caller explicitly
1597         * requests that.  Wait for some write requests to complete then retry.
1598         *
1599         * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
1600         * means __GFP_NOFAIL, but that may not be true in other
1601         * implementations.
1602         *
1603         * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
1604         * specified, then we retry until we no longer reclaim any pages
1605         * (above), or we've reclaimed an order of pages at least as
1606         * large as the allocation's order. In both cases, if the
1607         * allocation still fails, we stop retrying.
1608         */
1609        pages_reclaimed += did_some_progress;
1610        do_retry = 0;
1611        if (!(gfp_mask & __GFP_NORETRY)) {
1612                if (order <= PAGE_ALLOC_COSTLY_ORDER) {
1613                        do_retry = 1;
1614                } else {
1615                        if (gfp_mask & __GFP_REPEAT &&
1616                                pages_reclaimed < (1 << order))
1617                                        do_retry = 1;
1618                }
1619                if (gfp_mask & __GFP_NOFAIL)
1620                        do_retry = 1;
1621        }
1622        if (do_retry) {
1623                congestion_wait(WRITE, HZ/50);
1624                goto rebalance;
1625        }
1626
1627nopage:
1628        if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
1629                printk(KERN_WARNING "%s: page allocation failure."
1630                        " order:%d, mode:0x%x\n",
1631                        p->comm, order, gfp_mask);
1632                dump_stack();
1633                show_mem();
1634        }
1635got_pg:
1636        return page;
1637}
1638
1639struct page *
1640__alloc_pages(gfp_t gfp_mask, unsigned int order,
1641                struct zonelist *zonelist)
1642{
1643        return __alloc_pages_internal(gfp_mask, order, zonelist, NULL);
1644}
1645
1646struct page *
1647__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
1648                struct zonelist *zonelist, nodemask_t *nodemask)
1649{
1650        return __alloc_pages_internal(gfp_mask, order, zonelist, nodemask);
1651}
1652
1653EXPORT_SYMBOL(__alloc_pages);
1654
1655/*
1656 * Common helper functions.
1657 */
1658unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
1659{
1660        struct page * page;
1661        page = alloc_pages(gfp_mask, order);
1662        if (!page)
1663                return 0;
1664        return (unsigned long) page_address(page);
1665}
1666
1667EXPORT_SYMBOL(__get_free_pages);
1668
1669unsigned long get_zeroed_page(gfp_t gfp_mask)
1670{
1671        struct page * page;
1672
1673        /*
1674         * get_zeroed_page() returns a 32-bit address, which cannot represent
1675         * a highmem page
1676         */
1677        VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
1678
1679        page = alloc_pages(gfp_mask | __GFP_ZERO, 0);
1680        if (page)
1681                return (unsigned long) page_address(page);
1682        return 0;
1683}
1684
1685EXPORT_SYMBOL(get_zeroed_page);
1686
1687void __pagevec_free(struct pagevec *pvec)
1688{
1689        int i = pagevec_count(pvec);
1690
1691        while (--i >= 0)
1692                free_hot_cold_page(pvec->pages[i], pvec->cold);
1693}
1694
1695void __free_pages(struct page *page, unsigned int order)
1696{
1697        if (put_page_testzero(page)) {
1698                if (order == 0)
1699                        free_hot_page(page);
1700                else
1701                        __free_pages_ok(page, order);
1702        }
1703}
1704
1705EXPORT_SYMBOL(__free_pages);
1706
1707void free_pages(unsigned long addr, unsigned int order)
1708{
1709        if (addr != 0) {
1710                VM_BUG_ON(!virt_addr_valid((void *)addr));
1711                __free_pages(virt_to_page((void *)addr), order);
1712        }
1713}
1714
1715EXPORT_SYMBOL(free_pages);
1716
1717static unsigned int nr_free_zone_pages(int offset)
1718{
1719        struct zoneref *z;
1720        struct zone *zone;
1721
1722        /* Just pick one node, since fallback list is circular */
1723        unsigned int sum = 0;
1724
1725        struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
1726
1727        for_each_zone_zonelist(zone, z, zonelist, offset) {
1728                unsigned long size = zone->present_pages;
1729                unsigned long high = zone->pages_high;
1730                if (size > high)
1731                        sum += size - high;
1732        }
1733
1734        return sum;
1735}
1736
1737/*
1738 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
1739 */
1740unsigned int nr_free_buffer_pages(void)
1741{
1742        return nr_free_zone_pages(gfp_zone(GFP_USER));
1743}
1744EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
1745
1746/*
1747 * Amount of free RAM allocatable within all zones
1748 */
1749unsigned int nr_free_pagecache_pages(void)
1750{
1751        return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
1752}
1753
1754static inline void show_node(struct zone *zone)
1755{
1756        if (NUMA_BUILD)
1757                printk("Node %d ", zone_to_nid(zone));
1758}
1759
1760void si_meminfo(struct sysinfo *val)
1761{
1762        val->totalram = totalram_pages;
1763        val->sharedram = 0;
1764        val->freeram = global_page_state(NR_FREE_PAGES);
1765        val->bufferram = nr_blockdev_pages();
1766        val->totalhigh = totalhigh_pages;
1767        val->freehigh = nr_free_highpages();
1768        val->mem_unit = PAGE_SIZE;
1769}
1770
1771EXPORT_SYMBOL(si_meminfo);
1772
1773#ifdef CONFIG_NUMA
1774void si_meminfo_node(struct sysinfo *val, int nid)
1775{
1776        pg_data_t *pgdat = NODE_DATA(nid);
1777
1778        val->totalram = pgdat->node_present_pages;
1779        val->freeram = node_page_state(nid, NR_FREE_PAGES);
1780#ifdef CONFIG_HIGHMEM
1781        val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
1782        val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
1783                        NR_FREE_PAGES);
1784#else
1785        val->totalhigh = 0;
1786        val->freehigh = 0;
1787#endif
1788        val->mem_unit = PAGE_SIZE;
1789}
1790#endif
1791
1792#define K(x) ((x) << (PAGE_SHIFT-10))
1793
1794/*
1795 * Show free area list (used inside shift_scroll-lock stuff)
1796 * We also calculate the percentage fragmentation. We do this by counting the
1797 * memory on each free list with the exception of the first item on the list.
1798 */
1799void show_free_areas(void)
1800{
1801        int cpu;
1802        struct zone *zone;
1803
1804        for_each_zone(zone) {
1805                if (!populated_zone(zone))
1806                        continue;
1807
1808                show_node(zone);
1809                printk("%s per-cpu:\n", zone->name);
1810
1811                for_each_online_cpu(cpu) {
1812                        struct per_cpu_pageset *pageset;
1813
1814                        pageset = zone_pcp(zone, cpu);
1815
1816                        printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
1817                               cpu, pageset->pcp.high,
1818                               pageset->pcp.batch, pageset->pcp.count);
1819                }
1820        }
1821
1822        printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu\n"
1823                " free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
1824                global_page_state(NR_ACTIVE),
1825                global_page_state(NR_INACTIVE),
1826                global_page_state(NR_FILE_DIRTY),
1827                global_page_state(NR_WRITEBACK),
1828                global_page_state(NR_UNSTABLE_NFS),
1829                global_page_state(NR_FREE_PAGES),
1830                global_page_state(NR_SLAB_RECLAIMABLE) +
1831                        global_page_state(NR_SLAB_UNRECLAIMABLE),
1832                global_page_state(NR_FILE_MAPPED),
1833                global_page_state(NR_PAGETABLE),
1834                global_page_state(NR_BOUNCE));
1835
1836        for_each_zone(zone) {
1837                int i;
1838
1839                if (!populated_zone(zone))
1840                        continue;
1841
1842                show_node(zone);
1843                printk("%s"
1844                        " free:%lukB"
1845                        " min:%lukB"
1846                        " low:%lukB"
1847                        " high:%lukB"
1848                        " active:%lukB"
1849                        " inactive:%lukB"
1850                        " present:%lukB"
1851                        " pages_scanned:%lu"
1852                        " all_unreclaimable? %s"
1853                        "\n",
1854                        zone->name,
1855                        K(zone_page_state(zone, NR_FREE_PAGES)),
1856                        K(zone->pages_min),
1857                        K(zone->pages_low),
1858                        K(zone->pages_high),
1859                        K(zone_page_state(zone, NR_ACTIVE)),
1860                        K(zone_page_state(zone, NR_INACTIVE)),
1861                        K(zone->present_pages),
1862                        zone->pages_scanned,
1863                        (zone_is_all_unreclaimable(zone) ? "yes" : "no")
1864                        );
1865                printk("lowmem_reserve[]:");
1866                for (i = 0; i < MAX_NR_ZONES; i++)
1867                        printk(" %lu", zone->lowmem_reserve[i]);
1868                printk("\n");
1869        }
1870
1871        for_each_zone(zone) {
1872                unsigned long nr[MAX_ORDER], flags, order, total = 0;
1873
1874                if (!populated_zone(zone))
1875                        continue;
1876
1877                show_node(zone);
1878                printk("%s: ", zone->name);
1879
1880                spin_lock_irqsave(&zone->lock, flags);
1881                for (order = 0; order < MAX_ORDER; order++) {
1882                        nr[order] = zone->free_area[order].nr_free;
1883                        total += nr[order] << order;
1884                }
1885                spin_unlock_irqrestore(&zone->lock, flags);
1886                for (order = 0; order < MAX_ORDER; order++)
1887                        printk("%lu*%lukB ", nr[order], K(1UL) << order);
1888                printk("= %lukB\n", K(total));
1889        }
1890
1891        printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
1892
1893        show_swap_cache_info();
1894}
1895
1896static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
1897{
1898        zoneref->zone = zone;
1899        zoneref->zone_idx = zone_idx(zone);
1900}
1901
1902/*
1903 * Builds allocation fallback zone lists.
1904 *
1905 * Add all populated zones of a node to the zonelist.
1906 */
1907static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
1908                                int nr_zones, enum zone_type zone_type)
1909{
1910        struct zone *zone;
1911
1912        BUG_ON(zone_type >= MAX_NR_ZONES);
1913        zone_type++;
1914
1915        do {
1916                zone_type--;
1917                zone = pgdat->node_zones + zone_type;
1918                if (populated_zone(zone)) {
1919                        zoneref_set_zone(zone,
1920                                &zonelist->_zonerefs[nr_zones++]);
1921                        check_highest_zone(zone_type);
1922                }
1923
1924        } while (zone_type);
1925        return nr_zones;
1926}
1927
1928
1929/*
1930 *  zonelist_order:
1931 *  0 = automatic detection of better ordering.
1932 *  1 = order by ([node] distance, -zonetype)
1933 *  2 = order by (-zonetype, [node] distance)
1934 *
1935 *  If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
1936 *  the same zonelist. So only NUMA can configure this param.
1937 */
1938#define ZONELIST_ORDER_DEFAULT  0
1939#define ZONELIST_ORDER_NODE     1
1940#define ZONELIST_ORDER_ZONE     2
1941
1942/* zonelist order in the kernel.
1943 * set_zonelist_order() will set this to NODE or ZONE.
1944 */
1945static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
1946static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
1947
1948
1949#ifdef CONFIG_NUMA
1950/* The value user specified ....changed by config */
1951static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
1952/* string for sysctl */
1953#define NUMA_ZONELIST_ORDER_LEN 16
1954char numa_zonelist_order[16] = "default";
1955
1956/*
1957 * interface for configure zonelist ordering.
1958 * command line option "numa_zonelist_order"
1959 *      = "[dD]efault   - default, automatic configuration.
1960 *      = "[nN]ode      - order by node locality, then by zone within node
1961 *      = "[zZ]one      - order by zone, then by locality within zone
1962 */
1963
1964static int __parse_numa_zonelist_order(char *s)
1965{
1966        if (*s == 'd' || *s == 'D') {
1967                user_zonelist_order = ZONELIST_ORDER_DEFAULT;
1968        } else if (*s == 'n' || *s == 'N') {
1969                user_zonelist_order = ZONELIST_ORDER_NODE;
1970        } else if (*s == 'z' || *s == 'Z') {
1971                user_zonelist_order = ZONELIST_ORDER_ZONE;
1972        } else {
1973                printk(KERN_WARNING
1974                        "Ignoring invalid numa_zonelist_order value:  "
1975                        "%s\n", s);
1976                return -EINVAL;
1977        }
1978        return 0;
1979}
1980
1981static __init int setup_numa_zonelist_order(char *s)
1982{
1983        if (s)
1984                return __parse_numa_zonelist_order(s);
1985        return 0;
1986}
1987early_param("numa_zonelist_order", setup_numa_zonelist_order);
1988
1989/*
1990 * sysctl handler for numa_zonelist_order
1991 */
1992int numa_zonelist_order_handler(ctl_table *table, int write,
1993                struct file *file, void __user *buffer, size_t *length,
1994                loff_t *ppos)
1995{
1996        char saved_string[NUMA_ZONELIST_ORDER_LEN];
1997        int ret;
1998
1999        if (write)
2000                strncpy(saved_string, (char*)table->data,
2001                        NUMA_ZONELIST_ORDER_LEN);
2002        ret = proc_dostring(table, write, file, buffer, length, ppos);
2003        if (ret)
2004                return ret;
2005        if (write) {
2006                int oldval = user_zonelist_order;
2007                if (__parse_numa_zonelist_order((char*)table->data)) {
2008                        /*
2009                         * bogus value.  restore saved string
2010                         */
2011                        strncpy((char*)table->data, saved_string,
2012                                NUMA_ZONELIST_ORDER_LEN);
2013                        user_zonelist_order = oldval;
2014                } else if (oldval != user_zonelist_order)
2015                        build_all_zonelists();
2016        }
2017        return 0;
2018}
2019
2020
2021#define MAX_NODE_LOAD (num_online_nodes())
2022static int node_load[MAX_NUMNODES];
2023
2024/**
2025 * find_next_best_node - find the next node that should appear in a given node's fallback list
2026 * @node: node whose fallback list we're appending
2027 * @used_node_mask: nodemask_t of already used nodes
2028 *
2029 * We use a number of factors to determine which is the next node that should
2030 * appear on a given node's fallback list.  The node should not have appeared
2031 * already in @node's fallback list, and it should be the next closest node
2032 * according to the distance array (which contains arbitrary distance values
2033 * from each node to each node in the system), and should also prefer nodes
2034 * with no CPUs, since presumably they'll have very little allocation pressure
2035 * on them otherwise.
2036 * It returns -1 if no node is found.
2037 */
2038static int find_next_best_node(int node, nodemask_t *used_node_mask)
2039{
2040        int n, val;
2041        int min_val = INT_MAX;
2042        int best_node = -1;
2043        node_to_cpumask_ptr(tmp, 0);
2044
2045        /* Use the local node if we haven't already */
2046        if (!node_isset(node, *used_node_mask)) {
2047                node_set(node, *used_node_mask);
2048                return node;
2049        }
2050
2051        for_each_node_state(n, N_HIGH_MEMORY) {
2052
2053                /* Don't want a node to appear more than once */
2054                if (node_isset(n, *used_node_mask))
2055                        continue;
2056
2057                /* Use the distance array to find the distance */
2058                val = node_distance(node, n);
2059
2060                /* Penalize nodes under us ("prefer the next node") */
2061                val += (n < node);
2062
2063                /* Give preference to headless and unused nodes */
2064                node_to_cpumask_ptr_next(tmp, n);
2065                if (!cpus_empty(*tmp))
2066                        val += PENALTY_FOR_NODE_WITH_CPUS;
2067
2068                /* Slight preference for less loaded node */
2069                val *= (MAX_NODE_LOAD*MAX_NUMNODES);
2070                val += node_load[n];
2071
2072                if (val < min_val) {
2073                        min_val = val;
2074                        best_node = n;
2075                }
2076        }
2077
2078        if (best_node >= 0)
2079                node_set(best_node, *used_node_mask);
2080
2081        return best_node;
2082}
2083
2084
2085/*
2086 * Build zonelists ordered by node and zones within node.
2087 * This results in maximum locality--normal zone overflows into local
2088 * DMA zone, if any--but risks exhausting DMA zone.
2089 */
2090static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
2091{
2092        int j;
2093        struct zonelist *zonelist;
2094
2095        zonelist = &pgdat->node_zonelists[0];
2096        for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2097                ;
2098        j = build_zonelists_node(NODE_DATA(node), zonelist, j,
2099                                                        MAX_NR_ZONES - 1);
2100        zonelist->_zonerefs[j].zone = NULL;
2101        zonelist->_zonerefs[j].zone_idx = 0;
2102}
2103
2104/*
2105 * Build gfp_thisnode zonelists
2106 */
2107static void build_thisnode_zonelists(pg_data_t *pgdat)
2108{
2109        int j;
2110        struct zonelist *zonelist;
2111
2112        zonelist = &pgdat->node_zonelists[1];
2113        j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2114        zonelist->_zonerefs[j].zone = NULL;
2115        zonelist->_zonerefs[j].zone_idx = 0;
2116}
2117
2118/*
2119 * Build zonelists ordered by zone and nodes within zones.
2120 * This results in conserving DMA zone[s] until all Normal memory is
2121 * exhausted, but results in overflowing to remote node while memory
2122 * may still exist in local DMA zone.
2123 */
2124static int node_order[MAX_NUMNODES];
2125
2126static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
2127{
2128        int pos, j, node;
2129        int zone_type;          /* needs to be signed */
2130        struct zone *z;
2131        struct zonelist *zonelist;
2132
2133        zonelist = &pgdat->node_zonelists[0];
2134        pos = 0;
2135        for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
2136                for (j = 0; j < nr_nodes; j++) {
2137                        node = node_order[j];
2138                        z = &NODE_DATA(node)->node_zones[zone_type];
2139                        if (populated_zone(z)) {
2140                                zoneref_set_zone(z,
2141                                        &zonelist->_zonerefs[pos++]);
2142                                check_highest_zone(zone_type);
2143                        }
2144                }
2145        }
2146        zonelist->_zonerefs[pos].zone = NULL;
2147        zonelist->_zonerefs[pos].zone_idx = 0;
2148}
2149
2150static int default_zonelist_order(void)
2151{
2152        int nid, zone_type;
2153        unsigned long low_kmem_size,total_size;
2154        struct zone *z;
2155        int average_size;
2156        /*
2157         * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
2158         * If they are really small and used heavily, the system can fall
2159         * into OOM very easily.
2160         * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
2161         */
2162        /* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
2163        low_kmem_size = 0;
2164        total_size = 0;
2165        for_each_online_node(nid) {
2166                for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
2167                        z = &NODE_DATA(nid)->node_zones[zone_type];
2168                        if (populated_zone(z)) {
2169                                if (zone_type < ZONE_NORMAL)
2170                                        low_kmem_size += z->present_pages;
2171                                total_size += z->present_pages;
2172                        }
2173                }
2174        }
2175        if (!low_kmem_size ||  /* there are no DMA area. */
2176            low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
2177                return ZONELIST_ORDER_NODE;
2178        /*
2179         * look into each node's config.
2180         * If there is a node whose DMA/DMA32 memory is very big area on
2181         * local memory, NODE_ORDER may be suitable.
2182         */
2183        average_size = total_size /
2184                                (nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2185        for_each_online_node(nid) {
2186                low_kmem_size = 0;
2187                total_size = 0;
2188                for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
2189                        z = &NODE_DATA(nid)->node_zones[zone_type];
2190                        if (populated_zone(z)) {
2191                                if (zone_type < ZONE_NORMAL)
2192                                        low_kmem_size += z->present_pages;
2193                                total_size += z->present_pages;
2194                        }
2195                }
2196                if (low_kmem_size &&
2197                    total_size > average_size && /* ignore small node */
2198                    low_kmem_size > total_size * 70/100)
2199                        return ZONELIST_ORDER_NODE;
2200        }
2201        return ZONELIST_ORDER_ZONE;
2202}
2203
2204static void set_zonelist_order(void)
2205{
2206        if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
2207                current_zonelist_order = default_zonelist_order();
2208        else
2209                current_zonelist_order = user_zonelist_order;
2210}
2211
2212static void build_zonelists(pg_data_t *pgdat)
2213{
2214        int j, node, load;
2215        enum zone_type i;
2216        nodemask_t used_mask;
2217        int local_node, prev_node;
2218        struct zonelist *zonelist;
2219        int order = current_zonelist_order;
2220
2221        /* initialize zonelists */
2222        for (i = 0; i < MAX_ZONELISTS; i++) {
2223                zonelist = pgdat->node_zonelists + i;
2224                zonelist->_zonerefs[0].zone = NULL;
2225                zonelist->_zonerefs[0].zone_idx = 0;
2226        }
2227
2228        /* NUMA-aware ordering of nodes */
2229        local_node = pgdat->node_id;
2230        load = num_online_nodes();
2231        prev_node = local_node;
2232        nodes_clear(used_mask);
2233
2234        memset(node_load, 0, sizeof(node_load));
2235        memset(node_order, 0, sizeof(node_order));
2236        j = 0;
2237
2238        while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2239                int distance = node_distance(local_node, node);
2240
2241                /*
2242                 * If another node is sufficiently far away then it is better
2243                 * to reclaim pages in a zone before going off node.
2244                 */
2245                if (distance > RECLAIM_DISTANCE)
2246                        zone_reclaim_mode = 1;
2247
2248                /*
2249                 * We don't want to pressure a particular node.
2250                 * So adding penalty to the first node in same
2251                 * distance group to make it round-robin.
2252                 */
2253                if (distance != node_distance(local_node, prev_node))
2254                        node_load[node] = load;
2255
2256                prev_node = node;
2257                load--;
2258                if (order == ZONELIST_ORDER_NODE)
2259                        build_zonelists_in_node_order(pgdat, node);
2260                else
2261                        node_order[j++] = node; /* remember order */
2262        }
2263
2264        if (order == ZONELIST_ORDER_ZONE) {
2265                /* calculate node order -- i.e., DMA last! */
2266                build_zonelists_in_zone_order(pgdat, j);
2267        }
2268
2269        build_thisnode_zonelists(pgdat);
2270}
2271
2272/* Construct the zonelist performance cache - see further mmzone.h */
2273static void build_zonelist_cache(pg_data_t *pgdat)
2274{
2275        struct zonelist *zonelist;
2276        struct zonelist_cache *zlc;
2277        struct zoneref *z;
2278
2279        zonelist = &pgdat->node_zonelists[0];
2280        zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
2281        bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2282        for (z = zonelist->_zonerefs; z->zone; z++)
2283                zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2284}
2285
2286
2287#else   /* CONFIG_NUMA */
2288
2289static void set_zonelist_order(void)
2290{
2291        current_zonelist_order = ZONELIST_ORDER_ZONE;
2292}
2293
2294static void build_zonelists(pg_data_t *pgdat)
2295{
2296        int node, local_node;
2297        enum zone_type j;
2298        struct zonelist *zonelist;
2299
2300        local_node = pgdat->node_id;
2301
2302        zonelist = &pgdat->node_zonelists[0];
2303        j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2304
2305        /*
2306         * Now we build the zonelist so that it contains the zones
2307         * of all the other nodes.
2308         * We don't want to pressure a particular node, so when
2309         * building the zones for node N, we make sure that the
2310         * zones coming right after the local ones are those from
2311         * node N+1 (modulo N)
2312         */
2313        for (node = local_node + 1; node < MAX_NUMNODES; node++) {
2314                if (!node_online(node))
2315                        continue;
2316                j = build_zonelists_node(NODE_DATA(node), zonelist, j,
2317                                                        MAX_NR_ZONES - 1);
2318        }
2319        for (node = 0; node < local_node; node++) {
2320                if (!node_online(node))
2321                        continue;
2322                j = build_zonelists_node(NODE_DATA(node), zonelist, j,
2323                                                        MAX_NR_ZONES - 1);
2324        }
2325
2326        zonelist->_zonerefs[j].zone = NULL;
2327        zonelist->_zonerefs[j].zone_idx = 0;
2328}
2329
2330/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2331static void build_zonelist_cache(pg_data_t *pgdat)
2332{
2333        pgdat->node_zonelists[0].zlcache_ptr = NULL;
2334}
2335
2336#endif  /* CONFIG_NUMA */
2337
2338/* return values int ....just for stop_machine_run() */
2339static int __build_all_zonelists(void *dummy)
2340{
2341        int nid;
2342
2343        for_each_online_node(nid) {
2344                pg_data_t *pgdat = NODE_DATA(nid);
2345
2346                build_zonelists(pgdat);
2347                build_zonelist_cache(pgdat);
2348        }
2349        return 0;
2350}
2351
2352void build_all_zonelists(void)
2353{
2354        set_zonelist_order();
2355
2356        if (system_state == SYSTEM_BOOTING) {
2357                __build_all_zonelists(NULL);
2358                cpuset_init_current_mems_allowed();
2359        } else {
2360                /* we have to stop all cpus to guarantee there is no user
2361                   of zonelist */
2362                stop_machine_run(__build_all_zonelists, NULL, NR_CPUS);
2363                /* cpuset refresh routine should be here */
2364        }
2365        vm_total_pages = nr_free_pagecache_pages();
2366        /*
2367         * Disable grouping by mobility if the number of pages in the
2368         * system is too low to allow the mechanism to work. It would be
2369         * more accurate, but expensive to check per-zone. This check is
2370         * made on memory-hotadd so a system can start with mobility
2371         * disabled and enable it later
2372         */
2373        if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2374                page_group_by_mobility_disabled = 1;
2375        else
2376                page_group_by_mobility_disabled = 0;
2377
2378        printk("Built %i zonelists in %s order, mobility grouping %s.  "
2379                "Total pages: %ld\n",
2380                        num_online_nodes(),
2381                        zonelist_order_name[current_zonelist_order],
2382                        page_group_by_mobility_disabled ? "off" : "on",
2383                        vm_total_pages);
2384#ifdef CONFIG_NUMA
2385        printk("Policy zone: %s\n", zone_names[policy_zone]);
2386#endif
2387}
2388
2389/*
2390 * Helper functions to size the waitqueue hash table.
2391 * Essentially these want to choose hash table sizes sufficiently
2392 * large so that collisions trying to wait on pages are rare.
2393 * But in fact, the number of active page waitqueues on typical
2394 * systems is ridiculously low, less than 200. So this is even
2395 * conservative, even though it seems large.
2396 *
2397 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
2398 * waitqueues, i.e. the size of the waitq table given the number of pages.
2399 */
2400#define PAGES_PER_WAITQUEUE     256
2401
2402#ifndef CONFIG_MEMORY_HOTPLUG
2403static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
2404{
2405        unsigned long size = 1;
2406
2407        pages /= PAGES_PER_WAITQUEUE;
2408
2409        while (size < pages)
2410                size <<= 1;
2411
2412        /*
2413         * Once we have dozens or even hundreds of threads sleeping
2414         * on IO we've got bigger problems than wait queue collision.
2415         * Limit the size of the wait table to a reasonable size.
2416         */
2417        size = min(size, 4096UL);
2418
2419        return max(size, 4UL);
2420}
2421#else
2422/*
2423 * A zone's size might be changed by hot-add, so it is not possible to determine
2424 * a suitable size for its wait_table.  So we use the maximum size now.
2425 *
2426 * The max wait table size = 4096 x sizeof(wait_queue_head_t).   ie:
2427 *
2428 *    i386 (preemption config)    : 4096 x 16 = 64Kbyte.
2429 *    ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
2430 *    ia64, x86-64 (preemption)   : 4096 x 24 = 96Kbyte.
2431 *
2432 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
2433 * or more by the traditional way. (See above).  It equals:
2434 *
2435 *    i386, x86-64, powerpc(4K page size) : =  ( 2G + 1M)byte.
2436 *    ia64(16K page size)                 : =  ( 8G + 4M)byte.
2437 *    powerpc (64K page size)             : =  (32G +16M)byte.
2438 */
2439static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
2440{
2441        return 4096UL;
2442}
2443#endif
2444
2445/*
2446 * This is an integer logarithm so that shifts can be used later
2447 * to extract the more random high bits from the multiplicative
2448 * hash function before the remainder is taken.
2449 */
2450static inline unsigned long wait_table_bits(unsigned long size)
2451{
2452        return ffz(~size);
2453}
2454
2455#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))
2456
2457/*
2458 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2459 * of blocks reserved is based on zone->pages_min. The memory within the
2460 * reserve will tend to store contiguous free pages. Setting min_free_kbytes
2461 * higher will lead to a bigger reserve which will get freed as contiguous
2462 * blocks as reclaim kicks in
2463 */
2464static void setup_zone_migrate_reserve(struct zone *zone)
2465{
2466        unsigned long start_pfn, pfn, end_pfn;
2467        struct page *page;
2468        unsigned long reserve, block_migratetype;
2469
2470        /* Get the start pfn, end pfn and the number of blocks to reserve */
2471        start_pfn = zone->zone_start_pfn;
2472        end_pfn = start_pfn + zone->spanned_pages;
2473        reserve = roundup(zone->pages_min, pageblock_nr_pages) >>
2474                                                        pageblock_order;
2475
2476        for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2477                if (!pfn_valid(pfn))
2478                        continue;
2479                page = pfn_to_page(pfn);
2480
2481                /* Watch out for overlapping nodes */
2482                if (page_to_nid(page) != zone_to_nid(zone))
2483                        continue;
2484
2485                /* Blocks with reserved pages will never free, skip them. */
2486                if (PageReserved(page))
2487                        continue;
2488
2489                block_migratetype = get_pageblock_migratetype(page);
2490
2491                /* If this block is reserved, account for it */
2492                if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) {
2493                        reserve--;
2494                        continue;
2495                }
2496
2497                /* Suitable for reserving if this block is movable */
2498                if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) {
2499                        set_pageblock_migratetype(page, MIGRATE_RESERVE);
2500                        move_freepages_block(zone, page, MIGRATE_RESERVE);
2501                        reserve--;
2502                        continue;
2503                }
2504
2505                /*
2506                 * If the reserve is met and this is a previous reserved block,
2507                 * take it back
2508                 */
2509                if (block_migratetype == MIGRATE_RESERVE) {
2510                        set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2511                        move_freepages_block(zone, page, MIGRATE_MOVABLE);
2512                }
2513        }
2514}
2515
2516/*
2517 * Initially all pages are reserved - free ones are freed
2518 * up by free_all_bootmem() once the early boot process is
2519 * done. Non-atomic initialization, single-pass.
2520 */
2521void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
2522                unsigned long start_pfn, enum memmap_context context)
2523{
2524        struct page *page;
2525        unsigned long end_pfn = start_pfn + size;
2526        unsigned long pfn;
2527        struct zone *z;
2528
2529        z = &NODE_DATA(nid)->node_zones[zone];
2530        for (pfn = start_pfn; pfn < end_pfn; pfn++) {
2531                /*
2532                 * There can be holes in boot-time mem_map[]s
2533                 * handed to this function.  They do not
2534                 * exist on hotplugged memory.
2535                 */
2536                if (context == MEMMAP_EARLY) {
2537                        if (!early_pfn_valid(pfn))
2538                                continue;
2539                        if (!early_pfn_in_nid(pfn, nid))
2540                                continue;
2541                }
2542                page = pfn_to_page(pfn);
2543                set_page_links(page, zone, nid, pfn);
2544                init_page_count(page);
2545                reset_page_mapcount(page);
2546                SetPageReserved(page);
2547                /*
2548                 * Mark the block movable so that blocks are reserved for
2549                 * movable at startup. This will force kernel allocations
2550                 * to reserve their blocks rather than leaking throughout
2551                 * the address space during boot when many long-lived
2552                 * kernel allocations are made. Later some blocks near
2553                 * the start are marked MIGRATE_RESERVE by
2554                 * setup_zone_migrate_reserve()
2555                 *
2556                 * bitmap is created for zone's valid pfn range. but memmap
2557                 * can be created for invalid pages (for alignment)
2558                 * check here not to call set_pageblock_migratetype() against
2559                 * pfn out of zone.
2560                 */
2561                if ((z->zone_start_pfn <= pfn)
2562                    && (pfn < z->zone_start_pfn + z->spanned_pages)
2563                    && !(pfn & (pageblock_nr_pages - 1)))
2564                        set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2565
2566                INIT_LIST_HEAD(&page->lru);
2567#ifdef WANT_PAGE_VIRTUAL
2568                /* The shift won't overflow because ZONE_NORMAL is below 4G. */
2569                if (!is_highmem_idx(zone))
2570                        set_page_address(page, __va(pfn << PAGE_SHIFT));
2571#endif
2572        }
2573}
2574
2575static void __meminit zone_init_free_lists(struct zone *zone)
2576{
2577        int order, t;
2578        for_each_migratetype_order(order, t) {
2579                INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
2580                zone->free_area[order].nr_free = 0;
2581        }
2582}
2583
2584#ifndef __HAVE_ARCH_MEMMAP_INIT
2585#define memmap_init(size, nid, zone, start_pfn) \
2586        memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
2587#endif
2588
2589static int zone_batchsize(struct zone *zone)
2590{
2591        int batch;
2592
2593        /*
2594         * The per-cpu-pages pools are set to around 1000th of the
2595         * size of the zone.  But no more than 1/2 of a meg.
2596         *
2597         * OK, so we don't know how big the cache is.  So guess.
2598         */
2599        batch = zone->present_pages / 1024;
2600        if (batch * PAGE_SIZE > 512 * 1024)
2601                batch = (512 * 1024) / PAGE_SIZE;
2602        batch /= 4;             /* We effectively *= 4 below */
2603        if (batch < 1)
2604                batch = 1;
2605
2606        /*
2607         * Clamp the batch to a 2^n - 1 value. Having a power
2608         * of 2 value was found to be more likely to have
2609         * suboptimal cache aliasing properties in some cases.
2610         *
2611         * For example if 2 tasks are alternately allocating
2612         * batches of pages, one task can end up with a lot
2613         * of pages of one half of the possible page colors
2614         * and the other with pages of the other colors.
2615         */
2616        batch = (1 << (fls(batch + batch/2)-1)) - 1;
2617
2618        return batch;
2619}
2620
2621inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
2622{
2623        struct per_cpu_pages *pcp;
2624
2625        memset(p, 0, sizeof(*p));
2626
2627        pcp = &p->pcp;
2628        pcp->count = 0;
2629        pcp->high = 6 * batch;
2630        pcp->batch = max(1UL, 1 * batch);
2631        INIT_LIST_HEAD(&pcp->list);
2632}
2633
2634/*
2635 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
2636 * to the value high for the pageset p.
2637 */
2638
2639static void setup_pagelist_highmark(struct per_cpu_pageset *p,
2640                                unsigned long high)
2641{
2642        struct per_cpu_pages *pcp;
2643
2644        pcp = &p->pcp;
2645        pcp->high = high;
2646        pcp->batch = max(1UL, high/4);
2647        if ((high/4) > (PAGE_SHIFT * 8))
2648                pcp->batch = PAGE_SHIFT * 8;
2649}
2650
2651
2652#ifdef CONFIG_NUMA
2653/*
2654 * Boot pageset table. One per cpu which is going to be used for all
2655 * zones and all nodes. The parameters will be set in such a way
2656 * that an item put on a list will immediately be handed over to
2657 * the buddy list. This is safe since pageset manipulation is done
2658 * with interrupts disabled.
2659 *
2660 * Some NUMA counter updates may also be caught by the boot pagesets.
2661 *
2662 * The boot_pagesets must be kept even after bootup is complete for
2663 * unused processors and/or zones. They do play a role for bootstrapping
2664 * hotplugged processors.
2665 *
2666 * zoneinfo_show() and maybe other functions do
2667 * not check if the processor is online before following the pageset pointer.
2668 * Other parts of the kernel may not check if the zone is available.
2669 */
2670static struct per_cpu_pageset boot_pageset[NR_CPUS];
2671
2672/*
2673 * Dynamically allocate memory for the
2674 * per cpu pageset array in struct zone.
2675 */
2676static int __cpuinit process_zones(int cpu)
2677{
2678        struct zone *zone, *dzone;
2679        int node = cpu_to_node(cpu);
2680
2681        node_set_state(node, N_CPU);    /* this node has a cpu */
2682
2683        for_each_zone(zone) {
2684
2685                if (!populated_zone(zone))
2686                        continue;
2687
2688                zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
2689                                         GFP_KERNEL, node);
2690                if (!zone_pcp(zone, cpu))
2691                        goto bad;
2692
2693                setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
2694
2695                if (percpu_pagelist_fraction)
2696                        setup_pagelist_highmark(zone_pcp(zone, cpu),
2697                                (zone->present_pages / percpu_pagelist_fraction));
2698        }
2699
2700        return 0;
2701bad:
2702        for_each_zone(dzone) {
2703                if (!populated_zone(dzone))
2704                        continue;
2705                if (dzone == zone)
2706                        break;
2707                kfree(zone_pcp(dzone, cpu));
2708                zone_pcp(dzone, cpu) = NULL;
2709        }
2710        return -ENOMEM;
2711}
2712
2713static inline void free_zone_pagesets(int cpu)
2714{
2715        struct zone *zone;
2716
2717        for_each_zone(zone) {
2718                struct per_cpu_pageset *pset = zone_pcp(zone, cpu);
2719
2720                /* Free per_cpu_pageset if it is slab allocated */
2721                if (pset != &boot_pageset[cpu])
2722                        kfree(pset);
2723                zone_pcp(zone, cpu) = NULL;
2724        }
2725}
2726
2727static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
2728                unsigned long action,
2729                void *hcpu)
2730{
2731        int cpu = (long)hcpu;
2732        int ret = NOTIFY_OK;
2733
2734        switch (action) {
2735        case CPU_UP_PREPARE:
2736        case CPU_UP_PREPARE_FROZEN:
2737                if (process_zones(cpu))
2738                        ret = NOTIFY_BAD;
2739                break;
2740        case CPU_UP_CANCELED:
2741        case CPU_UP_CANCELED_FROZEN:
2742        case CPU_DEAD:
2743        case CPU_DEAD_FROZEN:
2744                free_zone_pagesets(cpu);
2745                break;
2746        default:
2747                break;
2748        }
2749        return ret;
2750}
2751
2752static struct notifier_block __cpuinitdata pageset_notifier =
2753        { &pageset_cpuup_callback, NULL, 0 };
2754
2755void __init setup_per_cpu_pageset(void)
2756{
2757        int err;
2758
2759        /* Initialize per_cpu_pageset for cpu 0.
2760         * A cpuup callback will do this for every cpu
2761         * as it comes online
2762         */
2763        err = process_zones(smp_processor_id());
2764        BUG_ON(err);
2765        register_cpu_notifier(&pageset_notifier);
2766}
2767
2768#endif
2769
2770static noinline __init_refok
2771int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
2772{
2773        int i;
2774        struct pglist_data *pgdat = zone->zone_pgdat;
2775        size_t alloc_size;
2776
2777        /*
2778         * The per-page waitqueue mechanism uses hashed waitqueues
2779         * per zone.
2780         */
2781        zone->wait_table_hash_nr_entries =
2782                 wait_table_hash_nr_entries(zone_size_pages);
2783        zone->wait_table_bits =
2784                wait_table_bits(zone->wait_table_hash_nr_entries);
2785        alloc_size = zone->wait_table_hash_nr_entries
2786                                        * sizeof(wait_queue_head_t);
2787
2788        if (!slab_is_available()) {
2789                zone->wait_table = (wait_queue_head_t *)
2790                        alloc_bootmem_node(pgdat, alloc_size);
2791        } else {
2792                /*
2793                 * This case means that a zone whose size was 0 gets new memory
2794                 * via memory hot-add.
2795                 * But it may be the case that a new node was hot-added.  In
2796                 * this case vmalloc() will not be able to use this new node's
2797                 * memory - this wait_table must be initialized to use this new
2798                 * node itself as well.
2799                 * To use this new node's memory, further consideration will be
2800                 * necessary.
2801                 */
2802                zone->wait_table = vmalloc(alloc_size);
2803        }
2804        if (!zone->wait_table)
2805                return -ENOMEM;
2806
2807        for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
2808                init_waitqueue_head(zone->wait_table + i);
2809
2810        return 0;
2811}
2812
2813static __meminit void zone_pcp_init(struct zone *zone)
2814{
2815        int cpu;
2816        unsigned long batch = zone_batchsize(zone);
2817
2818        for (cpu = 0; cpu < NR_CPUS; cpu++) {
2819#ifdef CONFIG_NUMA
2820                /* Early boot. Slab allocator not functional yet */
2821                zone_pcp(zone, cpu) = &boot_pageset[cpu];
2822                setup_pageset(&boot_pageset[cpu],0);
2823#else
2824                setup_pageset(zone_pcp(zone,cpu), batch);
2825#endif
2826        }
2827        if (zone->present_pages)
2828                printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%lu\n",
2829                        zone->name, zone->present_pages, batch);
2830}
2831
2832__meminit int init_currently_empty_zone(struct zone *zone,
2833                                        unsigned long zone_start_pfn,
2834                                        unsigned long size,
2835                                        enum memmap_context context)
2836{
2837        struct pglist_data *pgdat = zone->zone_pgdat;
2838        int ret;
2839        ret = zone_wait_table_init(zone, size);
2840        if (ret)
2841                return ret;
2842        pgdat->nr_zones = zone_idx(zone) + 1;
2843
2844        zone->zone_start_pfn = zone_start_pfn;
2845
2846        zone_init_free_lists(zone);
2847
2848        return 0;
2849}
2850
2851#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
2852/*
2853 * Basic iterator support. Return the first range of PFNs for a node
2854 * Note: nid == MAX_NUMNODES returns first region regardless of node
2855 */
2856static int __meminit first_active_region_index_in_nid(int nid)
2857{
2858        int i;
2859
2860        for (i = 0; i < nr_nodemap_entries; i++)
2861                if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
2862                        return i;
2863
2864        return -1;
2865}
2866
2867/*
2868 * Basic iterator support. Return the next active range of PFNs for a node
2869 * Note: nid == MAX_NUMNODES returns next region regardless of node
2870 */
2871static int __meminit next_active_region_index_in_nid(int index, int nid)
2872{
2873        for (index = index + 1; index < nr_nodemap_entries; index++)
2874                if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
2875                        return index;
2876
2877        return -1;
2878}
2879
2880#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
2881/*
2882 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
2883 * Architectures may implement their own version but if add_active_range()
2884 * was used and there are no special requirements, this is a convenient
2885 * alternative
2886 */
2887int __meminit early_pfn_to_nid(unsigned long pfn)
2888{
2889        int i;
2890
2891        for (i = 0; i < nr_nodemap_entries; i++) {
2892                unsigned long start_pfn = early_node_map[i].start_pfn;
2893                unsigned long end_pfn = early_node_map[i].end_pfn;
2894
2895                if (start_pfn <= pfn && pfn < end_pfn)
2896                        return early_node_map[i].nid;
2897        }
2898
2899        return 0;
2900}
2901#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
2902
2903/* Basic iterator support to walk early_node_map[] */
2904#define for_each_active_range_index_in_nid(i, nid) \
2905        for (i = first_active_region_index_in_nid(nid); i != -1; \
2906                                i = next_active_region_index_in_nid(i, nid))
2907
2908/**
2909 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
2910 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
2911 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
2912 *
2913 * If an architecture guarantees that all ranges registered with
2914 * add_active_ranges() contain no holes and may be freed, this
2915 * this function may be used instead of calling free_bootmem() manually.
2916 */
2917void __init free_bootmem_with_active_regions(int nid,
2918                                                unsigned long max_low_pfn)
2919{
2920        int i;
2921
2922        for_each_active_range_index_in_nid(i, nid) {
2923                unsigned long size_pages = 0;
2924                unsigned long end_pfn = early_node_map[i].end_pfn;
2925
2926                if (early_node_map[i].start_pfn >= max_low_pfn)
2927                        continue;
2928
2929                if (end_pfn > max_low_pfn)
2930                        end_pfn = max_low_pfn;
2931
2932                size_pages = end_pfn - early_node_map[i].start_pfn;
2933                free_bootmem_node(NODE_DATA(early_node_map[i].nid),
2934                                PFN_PHYS(early_node_map[i].start_pfn),
2935                                size_pages << PAGE_SHIFT);
2936        }
2937}
2938
2939/**
2940 * sparse_memory_present_with_active_regions - Call memory_present for each active range
2941 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
2942 *
2943 * If an architecture guarantees that all ranges registered with
2944 * add_active_ranges() contain no holes and may be freed, this
2945 * function may be used instead of calling memory_present() manually.
2946 */
2947void __init sparse_memory_present_with_active_regions(int nid)
2948{
2949        int i;
2950
2951        for_each_active_range_index_in_nid(i, nid)
2952                memory_present(early_node_map[i].nid,
2953                                early_node_map[i].start_pfn,
2954                                early_node_map[i].end_pfn);
2955}
2956
2957/**
2958 * push_node_boundaries - Push node boundaries to at least the requested boundary
2959 * @nid: The nid of the node to push the boundary for
2960 * @start_pfn: The start pfn of the node
2961 * @end_pfn: The end pfn of the node
2962 *
2963 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
2964 * time. Specifically, on x86_64, SRAT will report ranges that can potentially
2965 * be hotplugged even though no physical memory exists. This function allows
2966 * an arch to push out the node boundaries so mem_map is allocated that can
2967 * be used later.
2968 */
2969#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
2970void __init push_node_boundaries(unsigned int nid,
2971                unsigned long start_pfn, unsigned long end_pfn)
2972{
2973        printk(KERN_DEBUG "Entering push_node_boundaries(%u, %lu, %lu)\n",
2974                        nid, start_pfn, end_pfn);
2975
2976        /* Initialise the boundary for this node if necessary */
2977        if (node_boundary_end_pfn[nid] == 0)
2978                node_boundary_start_pfn[nid] = -1UL;
2979
2980        /* Update the boundaries */
2981        if (node_boundary_start_pfn[nid] > start_pfn)
2982                node_boundary_start_pfn[nid] = start_pfn;
2983        if (node_boundary_end_pfn[nid] < end_pfn)
2984                node_boundary_end_pfn[nid] = end_pfn;
2985}
2986
2987/* If necessary, push the node boundary out for reserve hotadd */
2988static void __meminit account_node_boundary(unsigned int nid,
2989                unsigned long *start_pfn, unsigned long *end_pfn)
2990{
2991        printk(KERN_DEBUG "Entering account_node_boundary(%u, %lu, %lu)\n",
2992                        nid, *start_pfn, *end_pfn);
2993
2994        /* Return if boundary information has not been provided */
2995        if (node_boundary_end_pfn[nid] == 0)
2996                return;
2997
2998        /* Check the boundaries and update if necessary */
2999        if (node_boundary_start_pfn[nid] < *start_pfn)
3000                *start_pfn = node_boundary_start_pfn[nid];
3001        if (node_boundary_end_pfn[nid] > *end_pfn)
3002                *end_pfn = node_boundary_end_pfn[nid];
3003}
3004#else
3005void __init push_node_boundaries(unsigned int nid,
3006                unsigned long start_pfn, unsigned long end_pfn) {}
3007
3008static void __meminit account_node_boundary(unsigned int nid,
3009                unsigned long *start_pfn, unsigned long *end_pfn) {}
3010#endif
3011
3012
3013/**
3014 * get_pfn_range_for_nid - Return the start and end page frames for a node
3015 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
3016 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
3017 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3018 *
3019 * It returns the start and end page frame of a node based on information
3020 * provided by an arch calling add_active_range(). If called for a node
3021 * with no available memory, a warning is printed and the start and end
3022 * PFNs will be 0.
3023 */
3024void __meminit get_pfn_range_for_nid(unsigned int nid,
3025                        unsigned long *start_pfn, unsigned long *end_pfn)
3026{
3027        int i;
3028        *start_pfn = -1UL;
3029        *end_pfn = 0;
3030
3031        for_each_active_range_index_in_nid(i, nid) {
3032                *start_pfn = min(*start_pfn, early_node_map[i].start_pfn);
3033                *end_pfn = max(*end_pfn, early_node_map[i].end_pfn);
3034        }
3035
3036        if (*start_pfn == -1UL)
3037                *start_pfn = 0;
3038
3039        /* Push the node boundaries out if requested */
3040        account_node_boundary(nid, start_pfn, end_pfn);
3041}
3042
3043/*
3044 * This finds a zone that can be used for ZONE_MOVABLE pages. The
3045 * assumption is made that zones within a node are ordered in monotonic
3046 * increasing memory addresses so that the "highest" populated zone is used
3047 */
3048void __init find_usable_zone_for_movable(void)
3049{
3050        int zone_index;
3051        for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
3052                if (zone_index == ZONE_MOVABLE)
3053                        continue;
3054
3055                if (arch_zone_highest_possible_pfn[zone_index] >
3056                                arch_zone_lowest_possible_pfn[zone_index])
3057                        break;
3058        }
3059
3060        VM_BUG_ON(zone_index == -1);
3061        movable_zone = zone_index;
3062}
3063
3064/*
3065 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
3066 * because it is sized independant of architecture. Unlike the other zones,
3067 * the starting point for ZONE_MOVABLE is not fixed. It may be different
3068 * in each node depending on the size of each node and how evenly kernelcore
3069 * is distributed. This helper function adjusts the zone ranges
3070 * provided by the architecture for a given node by using the end of the
3071 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
3072 * zones within a node are in order of monotonic increases memory addresses
3073 */
3074void __meminit adjust_zone_range_for_zone_movable(int nid,
3075                                        unsigned long zone_type,
3076                                        unsigned long node_start_pfn,
3077                                        unsigned long node_end_pfn,
3078                                        unsigned long *zone_start_pfn,
3079                                        unsigned long *zone_end_pfn)
3080{
3081        /* Only adjust if ZONE_MOVABLE is on this node */
3082        if (zone_movable_pfn[nid]) {
3083                /* Size ZONE_MOVABLE */
3084                if (zone_type == ZONE_MOVABLE) {
3085                        *zone_start_pfn = zone_movable_pfn[nid];
3086                        *zone_end_pfn = min(node_end_pfn,
3087                                arch_zone_highest_possible_pfn[movable_zone]);
3088
3089                /* Adjust for ZONE_MOVABLE starting within this range */
3090                } else if (*zone_start_pfn < zone_movable_pfn[nid] &&
3091                                *zone_end_pfn > zone_movable_pfn[nid]) {
3092                        *zone_end_pfn = zone_movable_pfn[nid];
3093
3094                /* Check if this whole range is within ZONE_MOVABLE */
3095                } else if (*zone_start_pfn >= zone_movable_pfn[nid])
3096                        *zone_start_pfn = *zone_end_pfn;
3097        }
3098}
3099
3100/*
3101 * Return the number of pages a zone spans in a node, including holes
3102 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
3103 */
3104static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3105                                        unsigned long zone_type,
3106                                        unsigned long *ignored)
3107{
3108        unsigned long node_start_pfn, node_end_pfn;
3109        unsigned long zone_start_pfn, zone_end_pfn;
3110
3111        /* Get the start and end of the node and zone */
3112        get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
3113        zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
3114        zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
3115        adjust_zone_range_for_zone_movable(nid, zone_type,
3116                                node_start_pfn, node_end_pfn,
3117                                &zone_start_pfn, &zone_end_pfn);
3118
3119        /* Check that this node has pages within the zone's required range */
3120        if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
3121                return 0;
3122
3123        /* Move the zone boundaries inside the node if necessary */
3124        zone_end_pfn = min(zone_end_pfn, node_end_pfn);
3125        zone_start_pfn = max(zone_start_pfn, node_start_pfn);
3126
3127        /* Return the spanned pages */
3128        return zone_end_pfn - zone_start_pfn;
3129}
3130
3131/*
3132 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3133 * then all holes in the requested range will be accounted for.
3134 */
3135unsigned long __meminit __absent_pages_in_range(int nid,
3136                                unsigned long range_start_pfn,
3137                                unsigned long range_end_pfn)
3138{
3139        int i = 0;
3140        unsigned long prev_end_pfn = 0, hole_pages = 0;
3141        unsigned long start_pfn;
3142
3143        /* Find the end_pfn of the first active range of pfns in the node */
3144        i = first_active_region_index_in_nid(nid);
3145        if (i == -1)
3146                return 0;
3147
3148        prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
3149
3150        /* Account for ranges before physical memory on this node */
3151        if (early_node_map[i].start_pfn > range_start_pfn)
3152                hole_pages = prev_end_pfn - range_start_pfn;
3153
3154        /* Find all holes for the zone within the node */
3155        for (; i != -1; i = next_active_region_index_in_nid(i, nid)) {
3156
3157                /* No need to continue if prev_end_pfn is outside the zone */
3158                if (prev_end_pfn >= range_end_pfn)
3159                        break;
3160
3161                /* Make sure the end of the zone is not within the hole */
3162                start_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
3163                prev_end_pfn = max(prev_end_pfn, range_start_pfn);
3164
3165                /* Update the hole size cound and move on */
3166                if (start_pfn > range_start_pfn) {
3167                        BUG_ON(prev_end_pfn > start_pfn);
3168                        hole_pages += start_pfn - prev_end_pfn;
3169                }
3170                prev_end_pfn = early_node_map[i].end_pfn;
3171        }
3172
3173        /* Account for ranges past physical memory on this node */
3174        if (range_end_pfn > prev_end_pfn)
3175                hole_pages += range_end_pfn -
3176                                max(range_start_pfn, prev_end_pfn);
3177
3178        return hole_pages;
3179}
3180
3181/**
3182 * absent_pages_in_range - Return number of page frames in holes within a range
3183 * @start_pfn: The start PFN to start searching for holes
3184 * @end_pfn: The end PFN to stop searching for holes
3185 *
3186 * It returns the number of pages frames in memory holes within a range.
3187 */
3188unsigned long __init absent_pages_in_range(unsigned long start_pfn,
3189                                                        unsigned long end_pfn)
3190{
3191        return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
3192}
3193
3194/* Return the number of page frames in holes in a zone on a node */
3195static unsigned long __meminit zone_absent_pages_in_node(int nid,
3196                                        unsigned long zone_type,
3197                                        unsigned long *ignored)
3198{
3199        unsigned long node_start_pfn, node_end_pfn;
3200        unsigned long zone_start_pfn, zone_end_pfn;
3201
3202        get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
3203        zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type],
3204                                                        node_start_pfn);
3205        zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type],
3206                                                        node_end_pfn);
3207
3208        adjust_zone_range_for_zone_movable(nid, zone_type,
3209                        node_start_pfn, node_end_pfn,
3210                        &zone_start_pfn, &zone_end_pfn);
3211        return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3212}
3213
3214#else
3215static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3216                                        unsigned long zone_type,
3217                                        unsigned long *zones_size)
3218{
3219        return zones_size[zone_type];
3220}
3221
3222static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3223                                                unsigned long zone_type,
3224                                                unsigned long *zholes_size)
3225{
3226        if (!zholes_size)
3227                return 0;
3228
3229        return zholes_size[zone_type];
3230}
3231
3232#endif
3233
3234static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3235                unsigned long *zones_size, unsigned long *zholes_size)
3236{
3237        unsigned long realtotalpages, totalpages = 0;
3238        enum zone_type i;
3239
3240        for (i = 0; i < MAX_NR_ZONES; i++)
3241                totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
3242                                                                zones_size);
3243        pgdat->node_spanned_pages = totalpages;
3244
3245        realtotalpages = totalpages;
3246        for (i = 0; i < MAX_NR_ZONES; i++)
3247                realtotalpages -=
3248                        zone_absent_pages_in_node(pgdat->node_id, i,
3249                                                                zholes_size);
3250        pgdat->node_present_pages = realtotalpages;
3251        printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
3252                                                        realtotalpages);
3253}
3254
3255#ifndef CONFIG_SPARSEMEM
3256/*
3257 * Calculate the size of the zone->blockflags rounded to an unsigned long
3258 * Start by making sure zonesize is a multiple of pageblock_order by rounding
3259 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3260 * round what is now in bits to nearest long in bits, then return it in
3261 * bytes.
3262 */
3263static unsigned long __init usemap_size(unsigned long zonesize)
3264{
3265        unsigned long usemapsize;
3266
3267        usemapsize = roundup(zonesize, pageblock_nr_pages);
3268        usemapsize = usemapsize >> pageblock_order;
3269        usemapsize *= NR_PAGEBLOCK_BITS;
3270        usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
3271
3272        return usemapsize / 8;
3273}
3274
3275static void __init setup_usemap(struct pglist_data *pgdat,
3276                                struct zone *zone, unsigned long zonesize)
3277{
3278        unsigned long usemapsize = usemap_size(zonesize);
3279        zone->pageblock_flags = NULL;
3280        if (usemapsize) {
3281                zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize);
3282                memset(zone->pageblock_flags, 0, usemapsize);
3283        }
3284}
3285#else
3286static void inline setup_usemap(struct pglist_data *pgdat,
3287                                struct zone *zone, unsigned long zonesize) {}
3288#endif /* CONFIG_SPARSEMEM */
3289
3290#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3291
3292/* Return a sensible default order for the pageblock size. */
3293static inline int pageblock_default_order(void)
3294{
3295        if (HPAGE_SHIFT > PAGE_SHIFT)
3296                return HUGETLB_PAGE_ORDER;
3297
3298        return MAX_ORDER-1;
3299}
3300
3301/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
3302static inline void __init set_pageblock_order(unsigned int order)
3303{
3304        /* Check that pageblock_nr_pages has not already been setup */
3305        if (pageblock_order)
3306                return;
3307
3308        /*
3309         * Assume the largest contiguous order of interest is a huge page.
3310         * This value may be variable depending on boot parameters on IA64
3311         */
3312        pageblock_order = order;
3313}
3314#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3315
3316/*
3317 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
3318 * and pageblock_default_order() are unused as pageblock_order is set
3319 * at compile-time. See include/linux/pageblock-flags.h for the values of
3320 * pageblock_order based on the kernel config
3321 */
3322static inline int pageblock_default_order(unsigned int order)
3323{
3324        return MAX_ORDER-1;
3325}
3326#define set_pageblock_order(x)  do {} while (0)
3327
3328#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
3329
3330/*
3331 * Set up the zone data structures:
3332 *   - mark all pages reserved
3333 *   - mark all memory queues empty
3334 *   - clear the memory bitmaps
3335 */
3336static void __paginginit free_area_init_core(struct pglist_data *pgdat,
3337                unsigned long *zones_size, unsigned long *zholes_size)
3338{
3339        enum zone_type j;
3340        int nid = pgdat->node_id;
3341        unsigned long zone_start_pfn = pgdat->node_start_pfn;
3342        int ret;
3343
3344        pgdat_resize_init(pgdat);
3345        pgdat->nr_zones = 0;
3346        init_waitqueue_head(&pgdat->kswapd_wait);
3347        pgdat->kswapd_max_order = 0;
3348        
3349        for (j = 0; j < MAX_NR_ZONES; j++) {
3350                struct zone *zone = pgdat->node_zones + j;
3351                unsigned long size, realsize, memmap_pages;
3352
3353                size = zone_spanned_pages_in_node(nid, j, zones_size);
3354                realsize = size - zone_absent_pages_in_node(nid, j,
3355                                                                zholes_size);
3356
3357                /*
3358                 * Adjust realsize so that it accounts for how much memory
3359                 * is used by this zone for memmap. This affects the watermark
3360                 * and per-cpu initialisations
3361                 */
3362                memmap_pages =
3363                        PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
3364                if (realsize >= memmap_pages) {
3365                        realsize -= memmap_pages;
3366                        printk(KERN_DEBUG
3367                                "  %s zone: %lu pages used for memmap\n",
3368                                zone_names[j], memmap_pages);
3369                } else
3370                        printk(KERN_WARNING
3371                                "  %s zone: %lu pages exceeds realsize %lu\n",
3372                                zone_names[j], memmap_pages, realsize);
3373
3374                /* Account for reserved pages */
3375                if (j == 0 && realsize > dma_reserve) {
3376                        realsize -= dma_reserve;
3377                        printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
3378                                        zone_names[0], dma_reserve);
3379                }
3380
3381                if (!is_highmem_idx(j))
3382                        nr_kernel_pages += realsize;
3383                nr_all_pages += realsize;
3384
3385                zone->spanned_pages = size;
3386                zone->present_pages = realsize;
3387#ifdef CONFIG_NUMA
3388                zone->node = nid;
3389                zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3390                                                / 100;
3391                zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3392#endif
3393                zone->name = zone_names[j];
3394                spin_lock_init(&zone->lock);
3395                spin_lock_init(&zone->lru_lock);
3396                zone_seqlock_init(zone);
3397                zone->zone_pgdat = pgdat;
3398
3399                zone->prev_priority = DEF_PRIORITY;
3400
3401                zone_pcp_init(zone);
3402                INIT_LIST_HEAD(&zone->active_list);
3403                INIT_LIST_HEAD(&zone->inactive_list);
3404                zone->nr_scan_active = 0;
3405                zone->nr_scan_inactive = 0;
3406                zap_zone_vm_stats(zone);
3407                zone->flags = 0;
3408                if (!size)
3409                        continue;
3410
3411                set_pageblock_order(pageblock_default_order());
3412                setup_usemap(pgdat, zone, size);
3413                ret = init_currently_empty_zone(zone, zone_start_pfn,
3414                                                size, MEMMAP_EARLY);
3415                BUG_ON(ret);
3416                memmap_init(size, nid, j, zone_start_pfn);
3417                zone_start_pfn += size;
3418        }
3419}
3420
3421static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
3422{
3423        /* Skip empty nodes */
3424        if (!pgdat->node_spanned_pages)
3425                return;
3426
3427#ifdef CONFIG_FLAT_NODE_MEM_MAP
3428        /* ia64 gets its own node_mem_map, before this, without bootmem */
3429        if (!pgdat->node_mem_map) {
3430                unsigned long size, start, end;
3431                struct page *map;
3432
3433                /*
3434                 * The zone's endpoints aren't required to be MAX_ORDER
3435                 * aligned but the node_mem_map endpoints must be in order
3436                 * for the buddy allocator to function correctly.
3437                 */
3438                start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
3439                end = pgdat->node_start_pfn + pgdat->node_spanned_pages;
3440                end = ALIGN(end, MAX_ORDER_NR_PAGES);
3441                size =  (end - start) * sizeof(struct page);
3442                map = alloc_remap(pgdat->node_id, size);
3443                if (!map)
3444                        map = alloc_bootmem_node(pgdat, size);
3445                pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
3446        }
3447#ifndef CONFIG_NEED_MULTIPLE_NODES
3448        /*
3449         * With no DISCONTIG, the global mem_map is just set as node 0's
3450         */
3451        if (pgdat == NODE_DATA(0)) {
3452                mem_map = NODE_DATA(0)->node_mem_map;
3453#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3454                if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3455                        mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3456#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3457        }
3458#endif
3459#endif /* CONFIG_FLAT_NODE_MEM_MAP */
3460}
3461
3462void __paginginit free_area_init_node(int nid, struct pglist_data *pgdat,
3463                unsigned long *zones_size, unsigned long node_start_pfn,
3464                unsigned long *zholes_size)
3465{
3466        pgdat->node_id = nid;
3467        pgdat->node_start_pfn = node_start_pfn;
3468        calculate_node_totalpages(pgdat, zones_size, zholes_size);
3469
3470        alloc_node_mem_map(pgdat);
3471
3472        free_area_init_core(pgdat, zones_size, zholes_size);
3473}
3474
3475#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
3476
3477#if MAX_NUMNODES > 1
3478/*
3479 * Figure out the number of possible node ids.
3480 */
3481static void __init setup_nr_node_ids(void)
3482{
3483        unsigned int node;
3484        unsigned int highest = 0;
3485
3486        for_each_node_mask(node, node_possible_map)
3487                highest = node;
3488        nr_node_ids = highest + 1;
3489}
3490#else
3491static inline void setup_nr_node_ids(void)
3492{
3493}
3494#endif
3495
3496/**
3497 * add_active_range - Register a range of PFNs backed by physical memory
3498 * @nid: The node ID the range resides on
3499 * @start_pfn: The start PFN of the available physical memory
3500 * @end_pfn: The end PFN of the available physical memory
3501 *
3502 * These ranges are stored in an early_node_map[] and later used by
3503 * free_area_init_nodes() to calculate zone sizes and holes. If the
3504 * range spans a memory hole, it is up to the architecture to ensure
3505 * the memory is not freed by the bootmem allocator. If possible
3506 * the range being registered will be merged with existing ranges.
3507 */
3508void __init add_active_range(unsigned int nid, unsigned long start_pfn,
3509                                                unsigned long end_pfn)
3510{
3511        int i;
3512
3513        printk(KERN_DEBUG "Entering add_active_range(%d, %lu, %lu) "
3514                          "%d entries of %d used\n",
3515                          nid, start_pfn, end_pfn,
3516                          nr_nodemap_entries, MAX_ACTIVE_REGIONS);
3517
3518        /* Merge with existing active regions if possible */
3519        for (i = 0; i < nr_nodemap_entries; i++) {
3520                if (early_node_map[i].nid != nid)
3521                        continue;
3522
3523                /* Skip if an existing region covers this new one */
3524                if (start_pfn >= early_node_map[i].start_pfn &&
3525                                end_pfn <= early_node_map[i].end_pfn)
3526                        return;
3527
3528                /* Merge forward if suitable */
3529                if (start_pfn <= early_node_map[i].end_pfn &&
3530                                end_pfn > early_node_map[i].end_pfn) {
3531                        early_node_map[i].end_pfn = end_pfn;
3532                        return;
3533                }
3534
3535                /* Merge backward if suitable */
3536                if (start_pfn < early_node_map[i].end_pfn &&
3537                                end_pfn >= early_node_map[i].start_pfn) {
3538                        early_node_map[i].start_pfn = start_pfn;
3539                        return;
3540                }
3541        }
3542
3543        /* Check that early_node_map is large enough */
3544        if (i >= MAX_ACTIVE_REGIONS) {
3545                printk(KERN_CRIT "More than %d memory regions, truncating\n",
3546                                                        MAX_ACTIVE_REGIONS);
3547                return;
3548        }
3549
3550        early_node_map[i].nid = nid;
3551        early_node_map[i].start_pfn = start_pfn;
3552        early_node_map[i].end_pfn = end_pfn;
3553        nr_nodemap_entries = i + 1;
3554}
3555
3556/**
3557 * shrink_active_range - Shrink an existing registered range of PFNs
3558 * @nid: The node id the range is on that should be shrunk
3559 * @old_end_pfn: The old end PFN of the range
3560 * @new_end_pfn: The new PFN of the range
3561 *
3562 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3563 * The map is kept at the end physical page range that has already been
3564 * registered with add_active_range(). This function allows an arch to shrink
3565 * an existing registered range.
3566 */
3567void __init shrink_active_range(unsigned int nid, unsigned long old_end_pfn,
3568                                                unsigned long new_end_pfn)
3569{
3570        int i;
3571
3572        /* Find the old active region end and shrink */
3573        for_each_active_range_index_in_nid(i, nid)
3574                if (early_node_map[i].end_pfn == old_end_pfn) {
3575                        early_node_map[i].end_pfn = new_end_pfn;
3576                        break;
3577                }
3578}
3579
3580/**
3581 * remove_all_active_ranges - Remove all currently registered regions
3582 *
3583 * During discovery, it may be found that a table like SRAT is invalid
3584 * and an alternative discovery method must be used. This function removes
3585 * all currently registered regions.
3586 */
3587void __init remove_all_active_ranges(void)
3588{
3589        memset(early_node_map, 0, sizeof(early_node_map));
3590        nr_nodemap_entries = 0;
3591#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
3592        memset(node_boundary_start_pfn, 0, sizeof(node_boundary_start_pfn));
3593        memset(node_boundary_end_pfn, 0, sizeof(node_boundary_end_pfn));
3594#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
3595}
3596
3597/* Compare two active node_active_regions */
3598static int __init cmp_node_active_region(const void *a, const void *b)
3599{
3600        struct node_active_region *arange = (struct node_active_region *)a;
3601        struct node_active_region *brange = (struct node_active_region *)b;
3602
3603        /* Done this way to avoid overflows */
3604        if (arange->start_pfn > brange->start_pfn)
3605                return 1;
3606        if (arange->start_pfn < brange->start_pfn)
3607                return -1;
3608
3609        return 0;
3610}
3611
3612/* sort the node_map by start_pfn */
3613static void __init sort_node_map(void)
3614{
3615        sort(early_node_map, (size_t)nr_nodemap_entries,
3616                        sizeof(struct node_active_region),
3617                        cmp_node_active_region, NULL);
3618}
3619
3620/* Find the lowest pfn for a node */
3621unsigned long __init find_min_pfn_for_node(unsigned long nid)
3622{
3623        int i;
3624        unsigned long min_pfn = ULONG_MAX;
3625
3626        /* Assuming a sorted map, the first range found has the starting pfn */
3627        for_each_active_range_index_in_nid(i, nid)
3628                min_pfn = min(min_pfn, early_node_map[i].start_pfn);
3629
3630        if (min_pfn == ULONG_MAX) {
3631                printk(KERN_WARNING
3632                        "Could not find start_pfn for node %lu\n", nid);
3633                return 0;
3634        }
3635
3636        return min_pfn;
3637}
3638
3639/**
3640 * find_min_pfn_with_active_regions - Find the minimum PFN registered
3641 *
3642 * It returns the minimum PFN based on information provided via
3643 * add_active_range().
3644 */
3645unsigned long __init find_min_pfn_with_active_regions(void)
3646{
3647        return find_min_pfn_for_node(MAX_NUMNODES);
3648}
3649
3650/**
3651 * find_max_pfn_with_active_regions - Find the maximum PFN registered
3652 *
3653 * It returns the maximum PFN based on information provided via
3654 * add_active_range().
3655 */
3656unsigned long __init find_max_pfn_with_active_regions(void)
3657{
3658        int i;
3659        unsigned long max_pfn = 0;
3660
3661        for (i = 0; i < nr_nodemap_entries; i++)
3662                max_pfn = max(max_pfn, early_node_map[i].end_pfn);
3663
3664        return max_pfn;
3665}
3666
3667/*
3668 * early_calculate_totalpages()
3669 * Sum pages in active regions for movable zone.
3670 * Populate N_HIGH_MEMORY for calculating usable_nodes.
3671 */
3672static unsigned long __init early_calculate_totalpages(void)
3673{
3674        int i;
3675        unsigned long totalpages = 0;
3676
3677        for (i = 0; i < nr_nodemap_entries; i++) {
3678                unsigned long pages = early_node_map[i].end_pfn -
3679                                                early_node_map[i].start_pfn;
3680                totalpages += pages;
3681                if (pages)
3682                        node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
3683        }
3684        return totalpages;
3685}
3686
3687/*
3688 * Find the PFN the Movable zone begins in each node. Kernel memory
3689 * is spread evenly between nodes as long as the nodes have enough
3690 * memory. When they don't, some nodes will have more kernelcore than
3691 * others
3692 */
3693void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
3694{
3695        int i, nid;
3696        unsigned long usable_startpfn;
3697        unsigned long kernelcore_node, kernelcore_remaining;
3698        unsigned long totalpages = early_calculate_totalpages();
3699        int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
3700
3701        /*
3702         * If movablecore was specified, calculate what size of
3703         * kernelcore that corresponds so that memory usable for
3704         * any allocation type is evenly spread. If both kernelcore
3705         * and movablecore are specified, then the value of kernelcore
3706         * will be used for required_kernelcore if it's greater than
3707         * what movablecore would have allowed.
3708         */
3709        if (required_movablecore) {
3710                unsigned long corepages;
3711
3712                /*
3713                 * Round-up so that ZONE_MOVABLE is at least as large as what
3714                 * was requested by the user
3715                 */
3716                required_movablecore =
3717                        roundup(required_movablecore, MAX_ORDER_NR_PAGES);
3718                corepages = totalpages - required_movablecore;
3719
3720                required_kernelcore = max(required_kernelcore, corepages);
3721        }
3722
3723        /* If kernelcore was not specified, there is no ZONE_MOVABLE */
3724        if (!required_kernelcore)
3725                return;
3726
3727        /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
3728        find_usable_zone_for_movable();
3729        usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
3730
3731restart:
3732        /* Spread kernelcore memory as evenly as possible throughout nodes */
3733        kernelcore_node = required_kernelcore / usable_nodes;
3734        for_each_node_state(nid, N_HIGH_MEMORY) {
3735                /*
3736                 * Recalculate kernelcore_node if the division per node
3737                 * now exceeds what is necessary to satisfy the requested
3738                 * amount of memory for the kernel
3739                 */
3740                if (required_kernelcore < kernelcore_node)
3741                        kernelcore_node = required_kernelcore / usable_nodes;
3742
3743                /*
3744                 * As the map is walked, we track how much memory is usable
3745                 * by the kernel using kernelcore_remaining. When it is
3746                 * 0, the rest of the node is usable by ZONE_MOVABLE
3747                 */
3748                kernelcore_remaining = kernelcore_node;
3749
3750                /* Go through each range of PFNs within this node */
3751                for_each_active_range_index_in_nid(i, nid) {
3752                        unsigned long start_pfn, end_pfn;
3753                        unsigned long size_pages;
3754
3755                        start_pfn = max(early_node_map[i].start_pfn,
3756                                                zone_movable_pfn[nid]);
3757                        end_pfn = early_node_map[i].end_pfn;
3758                        if (start_pfn >= end_pfn)
3759                                continue;
3760
3761                        /* Account for what is only usable for kernelcore */
3762                        if (start_pfn < usable_startpfn) {
3763                                unsigned long kernel_pages;
3764                                kernel_pages = min(end_pfn, usable_startpfn)
3765                                                                - start_pfn;
3766
3767                                kernelcore_remaining -= min(kernel_pages,
3768                                                        kernelcore_remaining);
3769                                required_kernelcore -= min(kernel_pages,
3770                                                        required_kernelcore);
3771
3772                                /* Continue if range is now fully accounted */
3773                                if (end_pfn <= usable_startpfn) {
3774
3775                                        /*
3776                                         * Push zone_movable_pfn to the end so
3777                                         * that if we have to rebalance
3778                                         * kernelcore across nodes, we will
3779                                         * not double account here
3780                                         */
3781                                        zone_movable_pfn[nid] = end_pfn;
3782                                        continue;
3783                                }
3784                                start_pfn = usable_startpfn;
3785                        }
3786
3787                        /*
3788                         * The usable PFN range for ZONE_MOVABLE is from
3789                         * start_pfn->end_pfn. Calculate size_pages as the
3790                         * number of pages used as kernelcore
3791                         */
3792                        size_pages = end_pfn - start_pfn;
3793                        if (size_pages > kernelcore_remaining)
3794                                size_pages = kernelcore_remaining;
3795                        zone_movable_pfn[nid] = start_pfn + size_pages;
3796
3797                        /*
3798                         * Some kernelcore has been met, update counts and
3799                         * break if the kernelcore for this node has been
3800                         * satisified
3801                         */
3802                        required_kernelcore -= min(required_kernelcore,
3803                                                                size_pages);
3804                        kernelcore_remaining -= size_pages;
3805                        if (!kernelcore_remaining)
3806                                break;
3807                }
3808        }
3809
3810        /*
3811         * If there is still required_kernelcore, we do another pass with one
3812         * less node in the count. This will push zone_movable_pfn[nid] further
3813         * along on the nodes that still have memory until kernelcore is
3814         * satisified
3815         */
3816        usable_nodes--;
3817        if (usable_nodes && required_kernelcore > usable_nodes)
3818                goto restart;
3819
3820        /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
3821        for (nid = 0; nid < MAX_NUMNODES; nid++)
3822                zone_movable_pfn[nid] =
3823                        roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
3824}
3825
3826/* Any regular memory on that node ? */
3827static void check_for_regular_memory(pg_data_t *pgdat)
3828{
3829#ifdef CONFIG_HIGHMEM
3830        enum zone_type zone_type;
3831
3832        for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) {
3833                struct zone *zone = &pgdat->node_zones[zone_type];
3834                if (zone->present_pages)
3835                        node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
3836        }
3837#endif
3838}
3839
3840/**
3841 * free_area_init_nodes - Initialise all pg_data_t and zone data
3842 * @max_zone_pfn: an array of max PFNs for each zone
3843 *
3844 * This will call free_area_init_node() for each active node in the system.
3845 * Using the page ranges provided by add_active_range(), the size of each
3846 * zone in each node and their holes is calculated. If the maximum PFN
3847 * between two adjacent zones match, it is assumed that the zone is empty.
3848 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
3849 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
3850 * starts where the previous one ended. For example, ZONE_DMA32 starts
3851 * at arch_max_dma_pfn.
3852 */
3853void __init free_area_init_nodes(unsigned long *max_zone_pfn)
3854{
3855        unsigned long nid;
3856        enum zone_type i;
3857
3858        /* Sort early_node_map as initialisation assumes it is sorted */
3859        sort_node_map();
3860
3861        /* Record where the zone boundaries are */
3862        memset(arch_zone_lowest_possible_pfn, 0,
3863                                sizeof(arch_zone_lowest_possible_pfn));
3864        memset(arch_zone_highest_possible_pfn, 0,
3865                                sizeof(arch_zone_highest_possible_pfn));
3866        arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
3867        arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
3868        for (i = 1; i < MAX_NR_ZONES; i++) {
3869                if (i == ZONE_MOVABLE)
3870                        continue;
3871                arch_zone_lowest_possible_pfn[i] =
3872                        arch_zone_highest_possible_pfn[i-1];
3873                arch_zone_highest_possible_pfn[i] =
3874                        max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
3875        }
3876        arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
3877        arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
3878
3879        /* Find the PFNs that ZONE_MOVABLE begins at in each node */
3880        memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
3881        find_zone_movable_pfns_for_nodes(zone_movable_pfn);
3882
3883        /* Print out the zone ranges */
3884        printk("Zone PFN ranges:\n");
3885        for (i = 0; i < MAX_NR_ZONES; i++) {
3886                if (i == ZONE_MOVABLE)
3887                        continue;
3888                printk("  %-8s %8lu -> %8lu\n",
3889                                zone_names[i],
3890                                arch_zone_lowest_possible_pfn[i],
3891                                arch_zone_highest_possible_pfn[i]);
3892        }
3893
3894        /* Print out the PFNs ZONE_MOVABLE begins at in each node */
3895        printk("Movable zone start PFN for each node\n");
3896        for (i = 0; i < MAX_NUMNODES; i++) {
3897                if (zone_movable_pfn[i])
3898                        printk("  Node %d: %lu\n", i, zone_movable_pfn[i]);
3899        }
3900
3901        /* Print out the early_node_map[] */
3902        printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries);
3903        for (i = 0; i < nr_nodemap_entries; i++)
3904                printk("  %3d: %8lu -> %8lu\n", early_node_map[i].nid,
3905                                                early_node_map[i].start_pfn,
3906                                                early_node_map[i].end_pfn);
3907
3908        /* Initialise every node */
3909        setup_nr_node_ids();
3910        for_each_online_node(nid) {
3911                pg_data_t *pgdat = NODE_DATA(nid);
3912                free_area_init_node(nid, pgdat, NULL,
3913                                find_min_pfn_for_node(nid), NULL);
3914
3915                /* Any memory on that node */
3916                if (pgdat->node_present_pages)
3917                        node_set_state(nid, N_HIGH_MEMORY);
3918                check_for_regular_memory(pgdat);
3919        }
3920}
3921
3922static int __init cmdline_parse_core(char *p, unsigned long *core)
3923{
3924        unsigned long long coremem;
3925        if (!p)
3926                return -EINVAL;
3927
3928        coremem = memparse(p, &p);
3929        *core = coremem >> PAGE_SHIFT;
3930
3931        /* Paranoid check that UL is enough for the coremem value */
3932        WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
3933
3934        return 0;
3935}
3936
3937/*
3938 * kernelcore=size sets the amount of memory for use for allocations that
3939 * cannot be reclaimed or migrated.
3940 */
3941static int __init cmdline_parse_kernelcore(char *p)
3942{
3943        return cmdline_parse_core(p, &required_kernelcore);
3944}
3945
3946/*
3947 * movablecore=size sets the amount of memory for use for allocations that
3948 * can be reclaimed or migrated.
3949 */
3950static int __init cmdline_parse_movablecore(char *p)
3951{
3952        return cmdline_parse_core(p, &required_movablecore);
3953}
3954
3955early_param("kernelcore", cmdline_parse_kernelcore);
3956early_param("movablecore", cmdline_parse_movablecore);
3957
3958#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
3959
3960/**
3961 * set_dma_reserve - set the specified number of pages reserved in the first zone
3962 * @new_dma_reserve: The number of pages to mark reserved
3963 *
3964 * The per-cpu batchsize and zone watermarks are determined by present_pages.
3965 * In the DMA zone, a significant percentage may be consumed by kernel image
3966 * and other unfreeable allocations which can skew the watermarks badly. This
3967 * function may optionally be used to account for unfreeable pages in the
3968 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
3969 * smaller per-cpu batchsize.
3970 */
3971void __init set_dma_reserve(unsigned long new_dma_reserve)
3972{
3973        dma_reserve = new_dma_reserve;
3974}
3975
3976#ifndef CONFIG_NEED_MULTIPLE_NODES
3977static bootmem_data_t contig_bootmem_data;
3978struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data };
3979
3980EXPORT_SYMBOL(contig_page_data);
3981#endif
3982
3983void __init free_area_init(unsigned long *zones_size)
3984{
3985        free_area_init_node(0, NODE_DATA(0), zones_size,
3986                        __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
3987}
3988
3989static int page_alloc_cpu_notify(struct notifier_block *self,
3990                                 unsigned long action, void *hcpu)
3991{
3992        int cpu = (unsigned long)hcpu;
3993
3994        if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
3995                drain_pages(cpu);
3996
3997                /*
3998                 * Spill the event counters of the dead processor
3999                 * into the current processors event counters.
4000                 * This artificially elevates the count of the current
4001                 * processor.
4002                 */
4003                vm_events_fold_cpu(cpu);
4004
4005                /*
4006                 * Zero the differential counters of the dead processor
4007                 * so that the vm statistics are consistent.
4008                 *
4009                 * This is only okay since the processor is dead and cannot
4010                 * race with what we are doing.
4011                 */
4012                refresh_cpu_vm_stats(cpu);
4013        }
4014        return NOTIFY_OK;
4015}
4016
4017void __init page_alloc_init(void)
4018{
4019        hotcpu_notifier(page_alloc_cpu_notify, 0);
4020}
4021
4022/*
4023 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
4024 *      or min_free_kbytes changes.
4025 */
4026static void calculate_totalreserve_pages(void)
4027{
4028        struct pglist_data *pgdat;
4029        unsigned long reserve_pages = 0;
4030        enum zone_type i, j;
4031
4032        for_each_online_pgdat(pgdat) {
4033                for (i = 0; i < MAX_NR_ZONES; i++) {
4034                        struct zone *zone = pgdat->node_zones + i;
4035                        unsigned long max = 0;
4036
4037                        /* Find valid and maximum lowmem_reserve in the zone */
4038                        for (j = i; j < MAX_NR_ZONES; j++) {
4039                                if (zone->lowmem_reserve[j] > max)
4040                                        max = zone->lowmem_reserve[j];
4041                        }
4042
4043                        /* we treat pages_high as reserved pages. */
4044                        max += zone->pages_high;
4045
4046                        if (max > zone->present_pages)
4047                                max = zone->present_pages;
4048                        reserve_pages += max;
4049                }
4050        }
4051        totalreserve_pages = reserve_pages;
4052}
4053
4054/*
4055 * setup_per_zone_lowmem_reserve - called whenever
4056 *      sysctl_lower_zone_reserve_ratio changes.  Ensures that each zone
4057 *      has a correct pages reserved value, so an adequate number of
4058 *      pages are left in the zone after a successful __alloc_pages().
4059 */
4060static void setup_per_zone_lowmem_reserve(void)
4061{
4062        struct pglist_data *pgdat;
4063        enum zone_type j, idx;
4064
4065        for_each_online_pgdat(pgdat) {
4066                for (j = 0; j < MAX_NR_ZONES; j++) {
4067                        struct zone *zone = pgdat->node_zones + j;
4068                        unsigned long present_pages = zone->present_pages;
4069
4070                        zone->lowmem_reserve[j] = 0;
4071
4072                        idx = j;
4073                        while (idx) {
4074                                struct zone *lower_zone;
4075
4076                                idx--;
4077
4078                                if (sysctl_lowmem_reserve_ratio[idx] < 1)
4079                                        sysctl_lowmem_reserve_ratio[idx] = 1;
4080
4081                                lower_zone = pgdat->node_zones + idx;
4082                                lower_zone->lowmem_reserve[j] = present_pages /
4083                                        sysctl_lowmem_reserve_ratio[idx];
4084                                present_pages += lower_zone->present_pages;
4085                        }
4086                }
4087        }
4088
4089        /* update totalreserve_pages */
4090        calculate_totalreserve_pages();
4091}
4092
4093/**
4094 * setup_per_zone_pages_min - called when min_free_kbytes changes.
4095 *
4096 * Ensures that the pages_{min,low,high} values for each zone are set correctly
4097 * with respect to min_free_kbytes.
4098 */
4099void setup_per_zone_pages_min(void)
4100{
4101        unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
4102        unsigned long lowmem_pages = 0;
4103        struct zone *zone;
4104        unsigned long flags;
4105
4106        /* Calculate total number of !ZONE_HIGHMEM pages */
4107        for_each_zone(zone) {
4108                if (!is_highmem(zone))
4109                        lowmem_pages += zone->present_pages;
4110        }
4111
4112        for_each_zone(zone) {
4113                u64 tmp;
4114
4115                spin_lock_irqsave(&zone->lru_lock, flags);
4116                tmp = (u64)pages_min * zone->present_pages;
4117                do_div(tmp, lowmem_pages);
4118                if (is_highmem(zone)) {
4119                        /*
4120                         * __GFP_HIGH and PF_MEMALLOC allocations usually don't
4121                         * need highmem pages, so cap pages_min to a small
4122                         * value here.
4123                         *
4124                         * The (pages_high-pages_low) and (pages_low-pages_min)
4125                         * deltas controls asynch page reclaim, and so should
4126                         * not be capped for highmem.
4127                         */
4128                        int min_pages;
4129
4130                        min_pages = zone->present_pages / 1024;
4131                        if (min_pages < SWAP_CLUSTER_MAX)
4132                                min_pages = SWAP_CLUSTER_MAX;
4133                        if (min_pages > 128)
4134                                min_pages = 128;
4135                        zone->pages_min = min_pages;
4136                } else {
4137                        /*
4138                         * If it's a lowmem zone, reserve a number of pages
4139                         * proportionate to the zone's size.
4140                         */
4141                        zone->pages_min = tmp;
4142                }
4143
4144                zone->pages_low   = zone->pages_min + (tmp >> 2);
4145                zone->pages_high  = zone->pages_min + (tmp >> 1);
4146                setup_zone_migrate_reserve(zone);
4147                spin_unlock_irqrestore(&zone->lru_lock, flags);
4148        }
4149
4150        /* update totalreserve_pages */
4151        calculate_totalreserve_pages();
4152}
4153
4154/*
4155 * Initialise min_free_kbytes.
4156 *
4157 * For small machines we want it small (128k min).  For large machines
4158 * we want it large (64MB max).  But it is not linear, because network
4159 * bandwidth does not increase linearly with machine size.  We use
4160 *
4161 *      min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
4162 *      min_free_kbytes = sqrt(lowmem_kbytes * 16)
4163 *
4164 * which yields
4165 *
4166 * 16MB:        512k
4167 * 32MB:        724k
4168 * 64MB:        1024k
4169 * 128MB:       1448k
4170 * 256MB:       2048k
4171 * 512MB:       2896k
4172 * 1024MB:      4096k
4173 * 2048MB:      5792k
4174 * 4096MB:      8192k
4175 * 8192MB:      11584k
4176 * 16384MB:     16384k
4177 */
4178static int __init init_per_zone_pages_min(void)
4179{
4180        unsigned long lowmem_kbytes;
4181
4182        lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
4183
4184        min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
4185        if (min_free_kbytes < 128)
4186                min_free_kbytes = 128;
4187        if (min_free_kbytes > 65536)
4188                min_free_kbytes = 65536;
4189        setup_per_zone_pages_min();
4190        setup_per_zone_lowmem_reserve();
4191        return 0;
4192}
4193module_init(init_per_zone_pages_min)
4194
4195/*
4196 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 
4197 *      that we can call two helper functions whenever min_free_kbytes
4198 *      changes.
4199 */
4200int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 
4201        struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4202{
4203        proc_dointvec(table, write, file, buffer, length, ppos);
4204        if (write)
4205                setup_per_zone_pages_min();
4206        return 0;
4207}
4208
4209#ifdef CONFIG_NUMA
4210int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
4211        struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4212{
4213        struct zone *zone;
4214        int rc;
4215
4216        rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4217        if (rc)
4218                return rc;
4219
4220        for_each_zone(zone)
4221                zone->min_unmapped_pages = (zone->present_pages *
4222                                sysctl_min_unmapped_ratio) / 100;
4223        return 0;
4224}
4225
4226int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
4227        struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4228{
4229        struct zone *zone;
4230        int rc;
4231
4232        rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4233        if (rc)
4234                return rc;
4235
4236        for_each_zone(zone)
4237                zone->min_slab_pages = (zone->present_pages *
4238                                sysctl_min_slab_ratio) / 100;
4239        return 0;
4240}
4241#endif
4242
4243/*
4244 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
4245 *      proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
4246 *      whenever sysctl_lowmem_reserve_ratio changes.
4247 *
4248 * The reserve ratio obviously has absolutely no relation with the
4249 * pages_min watermarks. The lowmem reserve ratio can only make sense
4250 * if in function of the boot time zone sizes.
4251 */
4252int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
4253        struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4254{
4255        proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4256        setup_per_zone_lowmem_reserve();
4257        return 0;
4258}
4259
4260/*
4261 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
4262 * cpu.  It is the fraction of total pages in each zone that a hot per cpu pagelist
4263 * can have before it gets flushed back to buddy allocator.
4264 */
4265
4266int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
4267        struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
4268{
4269        struct zone *zone;
4270        unsigned int cpu;
4271        int ret;
4272
4273        ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
4274        if (!write || (ret == -EINVAL))
4275                return ret;
4276        for_each_zone(zone) {
4277                for_each_online_cpu(cpu) {
4278                        unsigned long  high;
4279                        high = zone->present_pages / percpu_pagelist_fraction;
4280                        setup_pagelist_highmark(zone_pcp(zone, cpu), high);
4281                }
4282        }
4283        return 0;
4284}
4285
4286int hashdist = HASHDIST_DEFAULT;
4287
4288#ifdef CONFIG_NUMA
4289static int __init set_hashdist(char *str)
4290{
4291        if (!str)
4292                return 0;
4293        hashdist = simple_strtoul(str, &str, 0);
4294        return 1;
4295}
4296__setup("hashdist=", set_hashdist);
4297#endif
4298
4299/*
4300 * allocate a large system hash table from bootmem
4301 * - it is assumed that the hash table must contain an exact power-of-2
4302 *   quantity of entries
4303 * - limit is the number of hash buckets, not the total allocation size
4304 */
4305void *__init alloc_large_system_hash(const char *tablename,
4306                                     unsigned long bucketsize,
4307                                     unsigned long numentries,
4308                                     int scale,
4309                                     int flags,
4310                                     unsigned int *_hash_shift,
4311                                     unsigned int *_hash_mask,
4312                                     unsigned long limit)
4313{
4314        unsigned long long max = limit;
4315        unsigned long log2qty, size;
4316        void *table = NULL;
4317
4318        /* allow the kernel cmdline to have a say */
4319        if (!numentries) {
4320                /* round applicable memory size up to nearest megabyte */
4321                numentries = nr_kernel_pages;
4322                numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
4323                numentries >>= 20 - PAGE_SHIFT;
4324                numentries <<= 20 - PAGE_SHIFT;
4325
4326                /* limit to 1 bucket per 2^scale bytes of low memory */
4327                if (scale > PAGE_SHIFT)
4328                        numentries >>= (scale - PAGE_SHIFT);
4329                else
4330                        numentries <<= (PAGE_SHIFT - scale);
4331
4332                /* Make sure we've got at least a 0-order allocation.. */
4333                if (unlikely((numentries * bucketsize) < PAGE_SIZE))
4334                        numentries = PAGE_SIZE / bucketsize;
4335        }
4336        numentries = roundup_pow_of_two(numentries);
4337
4338        /* limit allocation size to 1/16 total memory by default */
4339        if (max == 0) {
4340                max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
4341                do_div(max, bucketsize);
4342        }
4343
4344        if (numentries > max)
4345                numentries = max;
4346
4347        log2qty = ilog2(numentries);
4348
4349        do {
4350                size = bucketsize << log2qty;
4351                if (flags & HASH_EARLY)
4352                        table = alloc_bootmem(size);
4353                else if (hashdist)
4354                        table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
4355                else {
4356                        unsigned long order = get_order(size);
4357                        table = (void*) __get_free_pages(GFP_ATOMIC, order);
4358                        /*
4359                         * If bucketsize is not a power-of-two, we may free
4360                         * some pages at the end of hash table.
4361                         */
4362                        if (table) {
4363                                unsigned long alloc_end = (unsigned long)table +
4364                                                (PAGE_SIZE << order);
4365                                unsigned long used = (unsigned long)table +
4366                                                PAGE_ALIGN(size);
4367                                split_page(virt_to_page(table), order);
4368                                while (used < alloc_end) {
4369                                        free_page(used);
4370                                        used += PAGE_SIZE;
4371                                }
4372                        }
4373                }
4374        } while (!table && size > PAGE_SIZE && --log2qty);
4375
4376        if (!table)
4377                panic("Failed to allocate %s hash table\n", tablename);
4378
4379        printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
4380               tablename,
4381               (1U << log2qty),
4382               ilog2(size) - PAGE_SHIFT,
4383               size);
4384
4385        if (_hash_shift)
4386                *_hash_shift = log2qty;
4387        if (_hash_mask)
4388                *_hash_mask = (1 << log2qty) - 1;
4389
4390        return table;
4391}
4392
4393#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
4394struct page *pfn_to_page(unsigned long pfn)
4395{
4396        return __pfn_to_page(pfn);
4397}
4398unsigned long page_to_pfn(struct page *page)
4399{
4400        return __page_to_pfn(page);
4401}
4402EXPORT_SYMBOL(pfn_to_page);
4403EXPORT_SYMBOL(page_to_pfn);
4404#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
4405
4406/* Return a pointer to the bitmap storing bits affecting a block of pages */
4407static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
4408                                                        unsigned long pfn)
4409{
4410#ifdef CONFIG_SPARSEMEM
4411        return __pfn_to_section(pfn)->pageblock_flags;
4412#else
4413        return zone->pageblock_flags;
4414#endif /* CONFIG_SPARSEMEM */
4415}
4416
4417static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
4418{
4419#ifdef CONFIG_SPARSEMEM
4420        pfn &= (PAGES_PER_SECTION-1);
4421        return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4422#else
4423        pfn = pfn - zone->zone_start_pfn;
4424        return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4425#endif /* CONFIG_SPARSEMEM */
4426}
4427
4428/**
4429 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4430 * @page: The page within the block of interest
4431 * @start_bitidx: The first bit of interest to retrieve
4432 * @end_bitidx: The last bit of interest
4433 * returns pageblock_bits flags
4434 */
4435unsigned long get_pageblock_flags_group(struct page *page,
4436                                        int start_bitidx, int end_bitidx)
4437{
4438        struct zone *zone;
4439        unsigned long *bitmap;
4440        unsigned long pfn, bitidx;
4441        unsigned long flags = 0;
4442        unsigned long value = 1;
4443
4444        zone = page_zone(page);
4445        pfn = page_to_pfn(page);
4446        bitmap = get_pageblock_bitmap(zone, pfn);
4447        bitidx = pfn_to_bitidx(zone, pfn);
4448
4449        for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
4450                if (test_bit(bitidx + start_bitidx, bitmap))
4451                        flags |= value;
4452
4453        return flags;
4454}
4455
4456/**
4457 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4458 * @page: The page within the block of interest
4459 * @start_bitidx: The first bit of interest
4460 * @end_bitidx: The last bit of interest
4461 * @flags: The flags to set
4462 */
4463void set_pageblock_flags_group(struct page *page, unsigned long flags,
4464                                        int start_bitidx, int end_bitidx)
4465{
4466        struct zone *zone;
4467        unsigned long *bitmap;
4468        unsigned long pfn, bitidx;
4469        unsigned long value = 1;
4470
4471        zone = page_zone(page);
4472        pfn = page_to_pfn(page);
4473        bitmap = get_pageblock_bitmap(zone, pfn);
4474        bitidx = pfn_to_bitidx(zone, pfn);
4475        VM_BUG_ON(pfn < zone->zone_start_pfn);
4476        VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
4477
4478        for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
4479                if (flags & value)
4480                        __set_bit(bitidx + start_bitidx, bitmap);
4481                else
4482                        __clear_bit(bitidx + start_bitidx, bitmap);
4483}
4484
4485/*
4486 * This is designed as sub function...plz see page_isolation.c also.
4487 * set/clear page block's type to be ISOLATE.
4488 * page allocater never alloc memory from ISOLATE block.
4489 */
4490
4491int set_migratetype_isolate(struct page *page)
4492{
4493        struct zone *zone;
4494        unsigned long flags;
4495        int ret = -EBUSY;
4496
4497        zone = page_zone(page);
4498        spin_lock_irqsave(&zone->lock, flags);
4499        /*
4500         * In future, more migrate types will be able to be isolation target.
4501         */
4502        if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE)
4503                goto out;
4504        set_pageblock_migratetype(page, MIGRATE_ISOLATE);
4505        move_freepages_block(zone, page, MIGRATE_ISOLATE);
4506        ret = 0;
4507out:
4508        spin_unlock_irqrestore(&zone->lock, flags);
4509        if (!ret)
4510                drain_all_pages();
4511        return ret;
4512}
4513
4514void unset_migratetype_isolate(struct page *page)
4515{
4516        struct zone *zone;
4517        unsigned long flags;
4518        zone = page_zone(page);
4519        spin_lock_irqsave(&zone->lock, flags);
4520        if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
4521                goto out;
4522        set_pageblock_migratetype(page, MIGRATE_MOVABLE);
4523        move_freepages_block(zone, page, MIGRATE_MOVABLE);
4524out:
4525        spin_unlock_irqrestore(&zone->lock, flags);
4526}
4527
4528#ifdef CONFIG_MEMORY_HOTREMOVE
4529/*
4530 * All pages in the range must be isolated before calling this.
4531 */
4532void
4533__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
4534{
4535        struct page *page;
4536        struct zone *zone;
4537        int order, i;
4538        unsigned long pfn;
4539        unsigned long flags;
4540        /* find the first valid pfn */
4541        for (pfn = start_pfn; pfn < end_pfn; pfn++)
4542                if (pfn_valid(pfn))
4543                        break;
4544        if (pfn == end_pfn)
4545                return;
4546        zone = page_zone(pfn_to_page(pfn));
4547        spin_lock_irqsave(&zone->lock, flags);
4548        pfn = start_pfn;
4549        while (pfn < end_pfn) {
4550                if (!pfn_valid(pfn)) {
4551                        pfn++;
4552                        continue;
4553                }
4554                page = pfn_to_page(pfn);
4555                BUG_ON(page_count(page));
4556                BUG_ON(!PageBuddy(page));
4557                order = page_order(page);
4558#ifdef CONFIG_DEBUG_VM
4559                printk(KERN_INFO "remove from free list %lx %d %lx\n",
4560                       pfn, 1 << order, end_pfn);
4561#endif
4562                list_del(&page->lru);
4563                rmv_page_order(page);
4564                zone->free_area[order].nr_free--;
4565                __mod_zone_page_state(zone, NR_FREE_PAGES,
4566                                      - (1UL << order));
4567                for (i = 0; i < (1 << order); i++)
4568                        SetPageReserved((page+i));
4569                pfn += (1 << order);
4570        }
4571        spin_unlock_irqrestore(&zone->lock, flags);
4572}
4573#endif
4574