page_alloc.c 128.8 KB
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/*
 *  linux/mm/page_alloc.c
 *
 *  Manages the free list, the system allocates free pages here.
 *  Note that kmalloc() lives in slab.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *  Swap reorganised 29.12.95, Stephen Tweedie
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *  Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
 *  Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
 *  Zone balancing, Kanoj Sarcar, SGI, Jan 2000
 *  Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
 *          (lots of bits borrowed from Ingo Molnar & Andrew Morton)
 */

#include <linux/stddef.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/interrupt.h>
#include <linux/pagemap.h>
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#include <linux/jiffies.h>
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#include <linux/bootmem.h>
#include <linux/compiler.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
#include <linux/suspend.h>
#include <linux/pagevec.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
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#include <linux/oom.h>
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#include <linux/notifier.h>
#include <linux/topology.h>
#include <linux/sysctl.h>
#include <linux/cpu.h>
#include <linux/cpuset.h>
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#include <linux/memory_hotplug.h>
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#include <linux/nodemask.h>
#include <linux/vmalloc.h>
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#include <linux/mempolicy.h>
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#include <linux/stop_machine.h>
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#include <linux/sort.h>
#include <linux/pfn.h>
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#include <linux/backing-dev.h>
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#include <linux/fault-inject.h>
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#include <linux/page-isolation.h>
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#include <linux/memcontrol.h>
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#include <linux/debugobjects.h>
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#include <asm/tlbflush.h>
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#include <asm/div64.h>
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#include "internal.h"

/*
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 * Array of node states.
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 */
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nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
	[N_POSSIBLE] = NODE_MASK_ALL,
	[N_ONLINE] = { { [0] = 1UL } },
#ifndef CONFIG_NUMA
	[N_NORMAL_MEMORY] = { { [0] = 1UL } },
#ifdef CONFIG_HIGHMEM
	[N_HIGH_MEMORY] = { { [0] = 1UL } },
#endif
	[N_CPU] = { { [0] = 1UL } },
#endif	/* NUMA */
};
EXPORT_SYMBOL(node_states);

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unsigned long totalram_pages __read_mostly;
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unsigned long totalreserve_pages __read_mostly;
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long nr_swap_pages;
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int percpu_pagelist_fraction;
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#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
int pageblock_order __read_mostly;
#endif

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static void __free_pages_ok(struct page *page, unsigned int order);
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/*
 * results with 256, 32 in the lowmem_reserve sysctl:
 *	1G machine -> (16M dma, 800M-16M normal, 1G-800M high)
 *	1G machine -> (16M dma, 784M normal, 224M high)
 *	NORMAL allocation will leave 784M/256 of ram reserved in the ZONE_DMA
 *	HIGHMEM allocation will leave 224M/32 of ram reserved in ZONE_NORMAL
 *	HIGHMEM allocation will (224M+784M)/256 of ram reserved in ZONE_DMA
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 *
 * TBD: should special case ZONE_DMA32 machines here - in those we normally
 * don't need any ZONE_NORMAL reservation
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 */
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int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
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#ifdef CONFIG_ZONE_DMA
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	 256,
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#endif
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#ifdef CONFIG_ZONE_DMA32
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	 256,
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#endif
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#ifdef CONFIG_HIGHMEM
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	 32,
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#endif
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	 32,
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};
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EXPORT_SYMBOL(totalram_pages);

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static char * const zone_names[MAX_NR_ZONES] = {
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#ifdef CONFIG_ZONE_DMA
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	 "DMA",
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#endif
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#ifdef CONFIG_ZONE_DMA32
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	 "DMA32",
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#endif
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	 "Normal",
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#ifdef CONFIG_HIGHMEM
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	 "HighMem",
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#endif
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	 "Movable",
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};

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int min_free_kbytes = 1024;

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unsigned long __meminitdata nr_kernel_pages;
unsigned long __meminitdata nr_all_pages;
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static unsigned long __meminitdata dma_reserve;
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#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
  /*
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   * MAX_ACTIVE_REGIONS determines the maximum number of distinct
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   * ranges of memory (RAM) that may be registered with add_active_range().
   * Ranges passed to add_active_range() will be merged if possible
   * so the number of times add_active_range() can be called is
   * related to the number of nodes and the number of holes
   */
  #ifdef CONFIG_MAX_ACTIVE_REGIONS
    /* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
    #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
  #else
    #if MAX_NUMNODES >= 32
      /* If there can be many nodes, allow up to 50 holes per node */
      #define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
    #else
      /* By default, allow up to 256 distinct regions */
      #define MAX_ACTIVE_REGIONS 256
    #endif
  #endif

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  static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS];
  static int __meminitdata nr_nodemap_entries;
  static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
  static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
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#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
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  static unsigned long __meminitdata node_boundary_start_pfn[MAX_NUMNODES];
  static unsigned long __meminitdata node_boundary_end_pfn[MAX_NUMNODES];
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#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
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  static unsigned long __initdata required_kernelcore;
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  static unsigned long __initdata required_movablecore;
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  static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
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  /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
  int movable_zone;
  EXPORT_SYMBOL(movable_zone);
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#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

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#if MAX_NUMNODES > 1
int nr_node_ids __read_mostly = MAX_NUMNODES;
EXPORT_SYMBOL(nr_node_ids);
#endif

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int page_group_by_mobility_disabled __read_mostly;

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static void set_pageblock_migratetype(struct page *page, int migratetype)
{
	set_pageblock_flags_group(page, (unsigned long)migratetype,
					PB_migrate, PB_migrate_end);
}

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#ifdef CONFIG_DEBUG_VM
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static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
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{
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	int ret = 0;
	unsigned seq;
	unsigned long pfn = page_to_pfn(page);
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	do {
		seq = zone_span_seqbegin(zone);
		if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
			ret = 1;
		else if (pfn < zone->zone_start_pfn)
			ret = 1;
	} while (zone_span_seqretry(zone, seq));

	return ret;
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}

static int page_is_consistent(struct zone *zone, struct page *page)
{
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	if (!pfn_valid_within(page_to_pfn(page)))
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		return 0;
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	if (zone != page_zone(page))
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		return 0;

	return 1;
}
/*
 * Temporary debugging check for pages not lying within a given zone.
 */
static int bad_range(struct zone *zone, struct page *page)
{
	if (page_outside_zone_boundaries(zone, page))
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		return 1;
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	if (!page_is_consistent(zone, page))
		return 1;

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	return 0;
}
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#else
static inline int bad_range(struct zone *zone, struct page *page)
{
	return 0;
}
#endif

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static void bad_page(struct page *page)
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{
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	void *pc = page_get_page_cgroup(page);

	printk(KERN_EMERG "Bad page state in process '%s'\n" KERN_EMERG
		"page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
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		current->comm, page, (int)(2*sizeof(unsigned long)),
		(unsigned long)page->flags, page->mapping,
		page_mapcount(page), page_count(page));
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	if (pc) {
		printk(KERN_EMERG "cgroup:%p\n", pc);
		page_reset_bad_cgroup(page);
	}
	printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n"
		KERN_EMERG "Backtrace:\n");
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	dump_stack();
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	page->flags &= ~PAGE_FLAGS_CLEAR_WHEN_BAD;
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	set_page_count(page, 0);
	reset_page_mapcount(page);
	page->mapping = NULL;
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	add_taint(TAINT_BAD_PAGE);
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}

/*
 * Higher-order pages are called "compound pages".  They are structured thusly:
 *
 * The first PAGE_SIZE page is called the "head page".
 *
 * The remaining PAGE_SIZE pages are called "tail pages".
 *
 * All pages have PG_compound set.  All pages have their ->private pointing at
 * the head page (even the head page has this).
 *
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 * The first tail page's ->lru.next holds the address of the compound page's
 * put_page() function.  Its ->lru.prev holds the order of allocation.
 * This usage means that zero-order pages may not be compound.
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 */
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static void free_compound_page(struct page *page)
{
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	__free_pages_ok(page, compound_order(page));
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}

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void prep_compound_page(struct page *page, unsigned long order)
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{
	int i;
	int nr_pages = 1 << order;
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	struct page *p = page + 1;
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	set_compound_page_dtor(page, free_compound_page);
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	set_compound_order(page, order);
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	__SetPageHead(page);
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	for (i = 1; i < nr_pages; i++, p++) {
		if (unlikely((i & (MAX_ORDER_NR_PAGES - 1)) == 0))
			p = pfn_to_page(page_to_pfn(page) + i);
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		__SetPageTail(p);
		p->first_page = page;
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	}
}

static void destroy_compound_page(struct page *page, unsigned long order)
{
	int i;
	int nr_pages = 1 << order;
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	struct page *p = page + 1;
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	if (unlikely(compound_order(page) != order))
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		bad_page(page);
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	if (unlikely(!PageHead(page)))
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			bad_page(page);
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	__ClearPageHead(page);
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	for (i = 1; i < nr_pages; i++, p++) {
		if (unlikely((i & (MAX_ORDER_NR_PAGES - 1)) == 0))
			p = pfn_to_page(page_to_pfn(page) + i);
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		if (unlikely(!PageTail(p) |
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				(p->first_page != page)))
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			bad_page(page);
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		__ClearPageTail(p);
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	}
}

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static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
{
	int i;

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	/*
	 * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
	 * and __GFP_HIGHMEM from hard or soft interrupt context.
	 */
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	VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
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	for (i = 0; i < (1 << order); i++)
		clear_highpage(page + i);
}

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static inline void set_page_order(struct page *page, int order)
{
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	set_page_private(page, order);
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	__SetPageBuddy(page);
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}

static inline void rmv_page_order(struct page *page)
{
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	__ClearPageBuddy(page);
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	set_page_private(page, 0);
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}

/*
 * Locate the struct page for both the matching buddy in our
 * pair (buddy1) and the combined O(n+1) page they form (page).
 *
 * 1) Any buddy B1 will have an order O twin B2 which satisfies
 * the following equation:
 *     B2 = B1 ^ (1 << O)
 * For example, if the starting buddy (buddy2) is #8 its order
 * 1 buddy is #10:
 *     B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
 *
 * 2) Any buddy B will have an order O+1 parent P which
 * satisfies the following equation:
 *     P = B & ~(1 << O)
 *
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 * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
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 */
static inline struct page *
__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order)
{
	unsigned long buddy_idx = page_idx ^ (1 << order);

	return page + (buddy_idx - page_idx);
}

static inline unsigned long
__find_combined_index(unsigned long page_idx, unsigned int order)
{
	return (page_idx & ~(1 << order));
}

/*
 * This function checks whether a page is free && is the buddy
 * we can do coalesce a page and its buddy if
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 * (a) the buddy is not in a hole &&
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 * (b) the buddy is in the buddy system &&
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 * (c) a page and its buddy have the same order &&
 * (d) a page and its buddy are in the same zone.
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 *
 * For recording whether a page is in the buddy system, we use PG_buddy.
 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
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 *
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 * For recording page's order, we use page_private(page).
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 */
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static inline int page_is_buddy(struct page *page, struct page *buddy,
								int order)
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{
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	if (!pfn_valid_within(page_to_pfn(buddy)))
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		return 0;

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	if (page_zone_id(page) != page_zone_id(buddy))
		return 0;

	if (PageBuddy(buddy) && page_order(buddy) == order) {
		BUG_ON(page_count(buddy) != 0);
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		return 1;
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	}
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	return 0;
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}

/*
 * Freeing function for a buddy system allocator.
 *
 * The concept of a buddy system is to maintain direct-mapped table
 * (containing bit values) for memory blocks of various "orders".
 * The bottom level table contains the map for the smallest allocatable
 * units of memory (here, pages), and each level above it describes
 * pairs of units from the levels below, hence, "buddies".
 * At a high level, all that happens here is marking the table entry
 * at the bottom level available, and propagating the changes upward
 * as necessary, plus some accounting needed to play nicely with other
 * parts of the VM system.
 * At each level, we keep a list of pages, which are heads of continuous
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 * free pages of length of (1 << order) and marked with PG_buddy. Page's
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 * order is recorded in page_private(page) field.
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 * So when we are allocating or freeing one, we can derive the state of the
 * other.  That is, if we allocate a small block, and both were   
 * free, the remainder of the region must be split into blocks.   
 * If a block is freed, and its buddy is also free, then this
 * triggers coalescing into a block of larger size.            
 *
 * -- wli
 */

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static inline void __free_one_page(struct page *page,
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		struct zone *zone, unsigned int order)
{
	unsigned long page_idx;
	int order_size = 1 << order;
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	int migratetype = get_pageblock_migratetype(page);
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	if (unlikely(PageCompound(page)))
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		destroy_compound_page(page, order);

	page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);

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	VM_BUG_ON(page_idx & (order_size - 1));
	VM_BUG_ON(bad_range(zone, page));
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	__mod_zone_page_state(zone, NR_FREE_PAGES, order_size);
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	while (order < MAX_ORDER-1) {
		unsigned long combined_idx;
		struct page *buddy;

		buddy = __page_find_buddy(page, page_idx, order);
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		if (!page_is_buddy(page, buddy, order))
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			break;
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		/* Our buddy is free, merge with it and move up one order. */
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		list_del(&buddy->lru);
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		zone->free_area[order].nr_free--;
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		rmv_page_order(buddy);
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		combined_idx = __find_combined_index(page_idx, order);
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		page = page + (combined_idx - page_idx);
		page_idx = combined_idx;
		order++;
	}
	set_page_order(page, order);
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	list_add(&page->lru,
		&zone->free_area[order].free_list[migratetype]);
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	zone->free_area[order].nr_free++;
}

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static inline int free_pages_check(struct page *page)
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{
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	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
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		(page_get_page_cgroup(page) != NULL) |
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		(page_count(page) != 0)  |
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		(page->flags & PAGE_FLAGS_CHECK_AT_FREE)))
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		bad_page(page);
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	if (PageDirty(page))
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		__ClearPageDirty(page);
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	if (PageSwapBacked(page))
		__ClearPageSwapBacked(page);
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	/*
	 * For now, we report if PG_reserved was found set, but do not
	 * clear it, and do not free the page.  But we shall soon need
	 * to do more, for when the ZERO_PAGE count wraps negative.
	 */
	return PageReserved(page);
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}

/*
 * Frees a list of pages. 
 * Assumes all pages on list are in same zone, and of same order.
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 * count is the number of pages to free.
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 *
 * If the zone was previously in an "all pages pinned" state then look to
 * see if this freeing clears that state.
 *
 * And clear the zone's pages_scanned counter, to hold off the "all pages are
 * pinned" detection logic.
 */
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static void free_pages_bulk(struct zone *zone, int count,
					struct list_head *list, int order)
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{
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	spin_lock(&zone->lock);
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	zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
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	zone->pages_scanned = 0;
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	while (count--) {
		struct page *page;

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		VM_BUG_ON(list_empty(list));
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		page = list_entry(list->prev, struct page, lru);
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		/* have to delete it as __free_one_page list manipulates */
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		list_del(&page->lru);
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		__free_one_page(page, zone, order);
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	}
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	spin_unlock(&zone->lock);
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}

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static void free_one_page(struct zone *zone, struct page *page, int order)
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{
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	spin_lock(&zone->lock);
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	zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
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	zone->pages_scanned = 0;
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	__free_one_page(page, zone, order);
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	spin_unlock(&zone->lock);
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}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
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	int i;
517
	int reserved = 0;
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	for (i = 0 ; i < (1 << order) ; ++i)
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		reserved += free_pages_check(page + i);
521 522 523
	if (reserved)
		return;

524
	if (!PageHighMem(page)) {
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		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
526 527 528
		debug_check_no_obj_freed(page_address(page),
					   PAGE_SIZE << order);
	}
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	arch_free_page(page, order);
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	kernel_map_pages(page, 1 << order, 0);
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	local_irq_save(flags);
533
	__count_vm_events(PGFREE, 1 << order);
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	free_one_page(page_zone(page), page, order);
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	local_irq_restore(flags);
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}

538 539 540
/*
 * permit the bootmem allocator to evade page validation on high-order frees
 */
541
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
542 543 544 545
{
	if (order == 0) {
		__ClearPageReserved(page);
		set_page_count(page, 0);
546
		set_page_refcounted(page);
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		__free_page(page);
548 549 550
	} else {
		int loop;

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		prefetchw(page);
552 553 554
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

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			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
557 558 559 560
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

561
		set_page_refcounted(page);
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		__free_pages(page, order);
563 564 565
	}
}

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/*
 * The order of subdivision here is critical for the IO subsystem.
 * Please do not alter this order without good reasons and regression
 * testing. Specifically, as large blocks of memory are subdivided,
 * the order in which smaller blocks are delivered depends on the order
 * they're subdivided in this function. This is the primary factor
 * influencing the order in which pages are delivered to the IO
 * subsystem according to empirical testing, and this is also justified
 * by considering the behavior of a buddy system containing a single
 * large block of memory acted on by a series of small allocations.
 * This behavior is a critical factor in sglist merging's success.
 *
 * -- wli
 */
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static inline void expand(struct zone *zone, struct page *page,
582 583
	int low, int high, struct free_area *area,
	int migratetype)
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{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
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		VM_BUG_ON(bad_range(zone, &page[size]));
592
		list_add(&page[size].lru, &area->free_list[migratetype]);
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		area->nr_free++;
		set_page_order(&page[size], high);
	}
}

/*
 * This page is about to be returned from the page allocator
 */
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static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
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{
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	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
605
		(page_get_page_cgroup(page) != NULL) |
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		(page_count(page) != 0)  |
607
		(page->flags & PAGE_FLAGS_CHECK_AT_PREP)))
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		bad_page(page);
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610 611 612 613 614 615 616
	/*
	 * For now, we report if PG_reserved was found set, but do not
	 * clear it, and do not allocate the page: as a safety net.
	 */
	if (PageReserved(page))
		return 1;

617
	page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_reclaim |
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			1 << PG_referenced | 1 << PG_arch_1 |
619
			1 << PG_owner_priv_1 | 1 << PG_mappedtodisk);
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	set_page_private(page, 0);
621
	set_page_refcounted(page);
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	arch_alloc_page(page, order);
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	kernel_map_pages(page, 1 << order, 1);
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	if (gfp_flags & __GFP_ZERO)
		prep_zero_page(page, order, gfp_flags);

	if (order && (gfp_flags & __GFP_COMP))
		prep_compound_page(page, order);

632
	return 0;
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}

635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665
/*
 * Go through the free lists for the given migratetype and remove
 * the smallest available page from the freelists
 */
static struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
						int migratetype)
{
	unsigned int current_order;
	struct free_area * area;
	struct page *page;

	/* Find a page of the appropriate size in the preferred list */
	for (current_order = order; current_order < MAX_ORDER; ++current_order) {
		area = &(zone->free_area[current_order]);
		if (list_empty(&area->free_list[migratetype]))
			continue;

		page = list_entry(area->free_list[migratetype].next,
							struct page, lru);
		list_del(&page->lru);
		rmv_page_order(page);
		area->nr_free--;
		__mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order));
		expand(zone, page, order, current_order, area, migratetype);
		return page;
	}

	return NULL;
}


666 667 668 669 670
/*
 * This array describes the order lists are fallen back to when
 * the free lists for the desirable migrate type are depleted
 */
static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
671 672 673 674
	[MIGRATE_UNMOVABLE]   = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE,   MIGRATE_RESERVE },
	[MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE,   MIGRATE_MOVABLE,   MIGRATE_RESERVE },
	[MIGRATE_MOVABLE]     = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
	[MIGRATE_RESERVE]     = { MIGRATE_RESERVE,     MIGRATE_RESERVE,   MIGRATE_RESERVE }, /* Never used */
675 676
};

677 678
/*
 * Move the free pages in a range to the free lists of the requested type.
679
 * Note that start_page and end_pages are not aligned on a pageblock
680 681
 * boundary. If alignment is required, use move_freepages_block()
 */
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static int move_freepages(struct zone *zone,
			  struct page *start_page, struct page *end_page,
			  int migratetype)
685 686 687
{
	struct page *page;
	unsigned long order;
688
	int pages_moved = 0;
689 690 691 692 693 694 695

#ifndef CONFIG_HOLES_IN_ZONE
	/*
	 * page_zone is not safe to call in this context when
	 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
	 * anyway as we check zone boundaries in move_freepages_block().
	 * Remove at a later date when no bug reports exist related to
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	 * grouping pages by mobility
697 698 699 700 701
	 */
	BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif

	for (page = start_page; page <= end_page;) {
702 703 704
		/* Make sure we are not inadvertently changing nodes */
		VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));

705 706 707 708 709 710 711 712 713 714 715 716 717 718 719
		if (!pfn_valid_within(page_to_pfn(page))) {
			page++;
			continue;
		}

		if (!PageBuddy(page)) {
			page++;
			continue;
		}

		order = page_order(page);
		list_del(&page->lru);
		list_add(&page->lru,
			&zone->free_area[order].free_list[migratetype]);
		page += 1 << order;
720
		pages_moved += 1 << order;
721 722
	}

723
	return pages_moved;
724 725
}

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static int move_freepages_block(struct zone *zone, struct page *page,
				int migratetype)
728 729 730 731 732
{
	unsigned long start_pfn, end_pfn;
	struct page *start_page, *end_page;

	start_pfn = page_to_pfn(page);
733
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
734
	start_page = pfn_to_page(start_pfn);
735 736
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
737 738 739 740 741 742 743 744 745 746

	/* Do not cross zone boundaries */
	if (start_pfn < zone->zone_start_pfn)
		start_page = page;
	if (end_pfn >= zone->zone_start_pfn + zone->spanned_pages)
		return 0;

	return move_freepages(zone, start_page, end_page, migratetype);
}

747 748 749 750 751 752 753 754 755 756 757 758 759 760 761
/* Remove an element from the buddy allocator from the fallback list */
static struct page *__rmqueue_fallback(struct zone *zone, int order,
						int start_migratetype)
{
	struct free_area * area;
	int current_order;
	struct page *page;
	int migratetype, i;

	/* Find the largest possible block of pages in the other list */
	for (current_order = MAX_ORDER-1; current_order >= order;
						--current_order) {
		for (i = 0; i < MIGRATE_TYPES - 1; i++) {
			migratetype = fallbacks[start_migratetype][i];

762 763 764
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
				continue;
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766 767 768 769 770 771 772 773 774
			area = &(zone->free_area[current_order]);
			if (list_empty(&area->free_list[migratetype]))
				continue;

			page = list_entry(area->free_list[migratetype].next,
					struct page, lru);
			area->nr_free--;

			/*
775
			 * If breaking a large block of pages, move all free
776 777 778
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
			 * agressive about taking ownership of free pages
779
			 */
780
			if (unlikely(current_order >= (pageblock_order >> 1)) ||
781 782 783 784 785 786
					start_migratetype == MIGRATE_RECLAIMABLE) {
				unsigned long pages;
				pages = move_freepages_block(zone, page,
								start_migratetype);

				/* Claim the whole block if over half of it is free */
787
				if (pages >= (1 << (pageblock_order-1)))
788 789 790
					set_pageblock_migratetype(page,
								start_migratetype);

791
				migratetype = start_migratetype;
792
			}
793 794 795 796 797 798 799

			/* Remove the page from the freelists */
			list_del(&page->lru);
			rmv_page_order(page);
			__mod_zone_page_state(zone, NR_FREE_PAGES,
							-(1UL << order));

800
			if (current_order == pageblock_order)
801 802 803 804 805 806 807 808
				set_pageblock_migratetype(page,
							start_migratetype);

			expand(zone, page, order, current_order, area, migratetype);
			return page;
		}
	}

809 810
	/* Use MIGRATE_RESERVE rather than fail an allocation */
	return __rmqueue_smallest(zone, order, MIGRATE_RESERVE);
811 812
}

813
/*
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 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
817 818
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
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{
	struct page *page;

822
	page = __rmqueue_smallest(zone, order, migratetype);
823

824 825
	if (unlikely(!page))
		page = __rmqueue_fallback(zone, order, migratetype);
826 827

	return page;
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}

/* 
 * Obtain a specified number of elements from the buddy allocator, all under
 * a single hold of the lock, for efficiency.  Add them to the supplied list.
 * Returns the number of new pages which were placed at *list.
 */
static int rmqueue_bulk(struct zone *zone, unsigned int order, 
836 837
			unsigned long count, struct list_head *list,
			int migratetype)
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838 839 840
{
	int i;
	
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	spin_lock(&zone->lock);
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842
	for (i = 0; i < count; ++i) {
843
		struct page *page = __rmqueue(zone, order, migratetype);
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		if (unlikely(page == NULL))
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			break;
846 847 848 849 850 851 852 853 854 855

		/*
		 * Split buddy pages returned by expand() are received here
		 * in physical page order. The page is added to the callers and
		 * list and the list head then moves forward. From the callers
		 * perspective, the linked list is ordered by page number in
		 * some conditions. This is useful for IO devices that can
		 * merge IO requests if the physical pages are ordered
		 * properly.
		 */
856 857
		list_add(&page->lru, list);
		set_page_private(page, migratetype);
858
		list = &page->lru;
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859
	}
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860
	spin_unlock(&zone->lock);
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861
	return i;
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862 863
}

864
#ifdef CONFIG_NUMA
865
/*
866 867 868 869
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
870 871
 * Note that this function must be called with the thread pinned to
 * a single processor.
872
 */
873
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
874 875
{
	unsigned long flags;
876
	int to_drain;
877

878 879 880 881 882 883 884 885
	local_irq_save(flags);
	if (pcp->count >= pcp->batch)
		to_drain = pcp->batch;
	else
		to_drain = pcp->count;
	free_pages_bulk(zone, to_drain, &pcp->list, 0);
	pcp->count -= to_drain;
	local_irq_restore(flags);
886 887 888
}
#endif

889 890 891 892 893 894 895 896
/*
 * Drain pages of the indicated processor.
 *
 * The processor must either be the current processor and the
 * thread pinned to the current processor or a processor that
 * is not online.
 */
static void drain_pages(unsigned int cpu)
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{
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	unsigned long flags;
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	struct zone *zone;

	for_each_zone(zone) {
		struct per_cpu_pageset *pset;
903
		struct per_cpu_pages *pcp;
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905 906 907
		if (!populated_zone(zone))
			continue;

908
		pset = zone_pcp(zone, cpu);
909 910 911 912 913 914

		pcp = &pset->pcp;
		local_irq_save(flags);
		free_pages_bulk(zone, pcp->count, &pcp->list, 0);
		pcp->count = 0;
		local_irq_restore(flags);
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	}
}

918 919 920 921 922 923 924 925 926 927 928 929 930
/*
 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
 */
void drain_local_pages(void *arg)
{
	drain_pages(smp_processor_id());
}

/*
 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
 */
void drain_all_pages(void)
{
931
	on_each_cpu(drain_local_pages, NULL, 1);
932 933
}

934
#ifdef CONFIG_HIBERNATION
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void mark_free_pages(struct zone *zone)
{
938 939
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
940
	int order, t;
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	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
947 948 949 950 951 952

	max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
	for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
		if (pfn_valid(pfn)) {
			struct page *page = pfn_to_page(pfn);

953 954
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
955
		}
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957 958
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
959
			unsigned long i;
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961 962
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
963
				swsusp_set_page_free(pfn_to_page(pfn + i));
964
		}
965
	}
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	spin_unlock_irqrestore(&zone->lock, flags);
}
968
#endif /* CONFIG_PM */
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/*
 * Free a 0-order page
 */
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static void free_hot_cold_page(struct page *page, int cold)
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{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;

	if (PageAnon(page))
		page->mapping = NULL;
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	if (free_pages_check(page))
982 983
		return;

984
	if (!PageHighMem(page)) {
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985
		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
986 987
		debug_check_no_obj_freed(page_address(page), PAGE_SIZE);
	}
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	arch_free_page(page, 0);
989 990
	kernel_map_pages(page, 1, 0);

991
	pcp = &zone_pcp(zone, get_cpu())->pcp;
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	local_irq_save(flags);
993
	__count_vm_event(PGFREE);
994 995 996 997
	if (cold)
		list_add_tail(&page->lru, &pcp->list);
	else
		list_add(&page->lru, &pcp->list);
998
	set_page_private(page, get_pageblock_migratetype(page));
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	pcp->count++;
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1000 1001 1002 1003
	if (pcp->count >= pcp->high) {
		free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
		pcp->count -= pcp->batch;
	}
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	local_irq_restore(flags);
	put_cpu();
}

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void free_hot_page(struct page *page)
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1009 1010 1011 1012
{
	free_hot_cold_page(page, 0);
}
	
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void free_cold_page(struct page *page)
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1014 1015 1016 1017
{
	free_hot_cold_page(page, 1);
}

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/*
 * split_page takes a non-compound higher-order page, and splits it into
 * n (1<<order) sub-pages: page[0..n]
 * Each sub-page must be freed individually.
 *
 * Note: this is probably too low level an operation for use in drivers.
 * Please consult with lkml before using this in your driver.
 */
void split_page(struct page *page, unsigned int order)
{
	int i;

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	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1032 1033
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
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1034 1035
}

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/*
 * Really, prep_compound_page() should be called from __rmqueue_bulk().  But
 * we cheat by calling it from here, in the order > 0 path.  Saves a branch
 * or two.
 */
1041
static struct page *buffered_rmqueue(struct zone *preferred_zone,
N
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1042
			struct zone *zone, int order, gfp_t gfp_flags)
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1043 1044
{
	unsigned long flags;
1045
	struct page *page;
L
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1046
	int cold = !!(gfp_flags & __GFP_COLD);
N
Nick Piggin 已提交
1047
	int cpu;
1048
	int migratetype = allocflags_to_migratetype(gfp_flags);
L
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1049

1050
again:
N
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1051
	cpu  = get_cpu();
N
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1052
	if (likely(order == 0)) {
L
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1053 1054
		struct per_cpu_pages *pcp;

1055
		pcp = &zone_pcp(zone, cpu)->pcp;
L
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1056
		local_irq_save(flags);
N
Nick Piggin 已提交
1057
		if (!pcp->count) {
1058
			pcp->count = rmqueue_bulk(zone, 0,
1059
					pcp->batch, &pcp->list, migratetype);
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Nick Piggin 已提交
1060 1061
			if (unlikely(!pcp->count))
				goto failed;
L
Linus Torvalds 已提交
1062
		}
1063

1064
		/* Find a page of the appropriate migrate type */
1065 1066 1067 1068 1069 1070 1071 1072 1073
		if (cold) {
			list_for_each_entry_reverse(page, &pcp->list, lru)
				if (page_private(page) == migratetype)
					break;
		} else {
			list_for_each_entry(page, &pcp->list, lru)
				if (page_private(page) == migratetype)
					break;
		}
1074

1075 1076
		/* Allocate more to the pcp list if necessary */
		if (unlikely(&page->lru == &pcp->list)) {
1077 1078 1079 1080
			pcp->count += rmqueue_bulk(zone, 0,
					pcp->batch, &pcp->list, migratetype);
			page = list_entry(pcp->list.next, struct page, lru);
		}
1081 1082 1083

		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1084
	} else {
L
Linus Torvalds 已提交
1085
		spin_lock_irqsave(&zone->lock, flags);
1086
		page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1087 1088 1089
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
L
Linus Torvalds 已提交
1090 1091
	}

1092
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1093
	zone_statistics(preferred_zone, zone);
N
Nick Piggin 已提交
1094 1095
	local_irq_restore(flags);
	put_cpu();
L
Linus Torvalds 已提交
1096

N
Nick Piggin 已提交
1097
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1098
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1099
		goto again;
L
Linus Torvalds 已提交
1100
	return page;
N
Nick Piggin 已提交
1101 1102 1103 1104 1105

failed:
	local_irq_restore(flags);
	put_cpu();
	return NULL;
L
Linus Torvalds 已提交
1106 1107
}

R
Rohit Seth 已提交
1108
#define ALLOC_NO_WATERMARKS	0x01 /* don't check watermarks at all */
1109 1110 1111 1112 1113 1114
#define ALLOC_WMARK_MIN		0x02 /* use pages_min watermark */
#define ALLOC_WMARK_LOW		0x04 /* use pages_low watermark */
#define ALLOC_WMARK_HIGH	0x08 /* use pages_high watermark */
#define ALLOC_HARDER		0x10 /* try to alloc harder */
#define ALLOC_HIGH		0x20 /* __GFP_HIGH set */
#define ALLOC_CPUSET		0x40 /* check for correct cpuset */
R
Rohit Seth 已提交
1115

1116 1117 1118 1119 1120 1121 1122
#ifdef CONFIG_FAIL_PAGE_ALLOC

static struct fail_page_alloc_attr {
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1123
	u32 min_order;
1124 1125 1126 1127 1128

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

	struct dentry *ignore_gfp_highmem_file;
	struct dentry *ignore_gfp_wait_file;
1129
	struct dentry *min_order_file;
1130 1131 1132 1133 1134

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1135 1136
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1137
	.min_order = 1,
1138 1139 1140 1141 1142 1143 1144 1145 1146 1147
};

static int __init setup_fail_page_alloc(char *str)
{
	return setup_fault_attr(&fail_page_alloc.attr, str);
}
__setup("fail_page_alloc=", setup_fail_page_alloc);

static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
{
1148 1149
	if (order < fail_page_alloc.min_order)
		return 0;
1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180
	if (gfp_mask & __GFP_NOFAIL)
		return 0;
	if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
		return 0;
	if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
		return 0;

	return should_fail(&fail_page_alloc.attr, 1 << order);
}

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

static int __init fail_page_alloc_debugfs(void)
{
	mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
	struct dentry *dir;
	int err;

	err = init_fault_attr_dentries(&fail_page_alloc.attr,
				       "fail_page_alloc");
	if (err)
		return err;
	dir = fail_page_alloc.attr.dentries.dir;

	fail_page_alloc.ignore_gfp_wait_file =
		debugfs_create_bool("ignore-gfp-wait", mode, dir,
				      &fail_page_alloc.ignore_gfp_wait);

	fail_page_alloc.ignore_gfp_highmem_file =
		debugfs_create_bool("ignore-gfp-highmem", mode, dir,
				      &fail_page_alloc.ignore_gfp_highmem);
1181 1182 1183
	fail_page_alloc.min_order_file =
		debugfs_create_u32("min-order", mode, dir,
				   &fail_page_alloc.min_order);
1184 1185

	if (!fail_page_alloc.ignore_gfp_wait_file ||
1186 1187
            !fail_page_alloc.ignore_gfp_highmem_file ||
            !fail_page_alloc.min_order_file) {
1188 1189 1190
		err = -ENOMEM;
		debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
		debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1191
		debugfs_remove(fail_page_alloc.min_order_file);
1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210
		cleanup_fault_attr_dentries(&fail_page_alloc.attr);
	}

	return err;
}

late_initcall(fail_page_alloc_debugfs);

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

#else /* CONFIG_FAIL_PAGE_ALLOC */

static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
{
	return 0;
}

#endif /* CONFIG_FAIL_PAGE_ALLOC */

L
Linus Torvalds 已提交
1211 1212 1213 1214 1215
/*
 * Return 1 if free pages are above 'mark'. This takes into account the order
 * of the allocation.
 */
int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
R
Rohit Seth 已提交
1216
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
1217 1218
{
	/* free_pages my go negative - that's OK */
1219 1220
	long min = mark;
	long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
L
Linus Torvalds 已提交
1221 1222
	int o;

R
Rohit Seth 已提交
1223
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1224
		min -= min / 2;
R
Rohit Seth 已提交
1225
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242
		min -= min / 4;

	if (free_pages <= min + z->lowmem_reserve[classzone_idx])
		return 0;
	for (o = 0; o < order; o++) {
		/* At the next order, this order's pages become unavailable */
		free_pages -= z->free_area[o].nr_free << o;

		/* Require fewer higher order pages to be free */
		min >>= 1;

		if (free_pages <= min)
			return 0;
	}
	return 1;
}

1243 1244 1245 1246 1247 1248
#ifdef CONFIG_NUMA
/*
 * zlc_setup - Setup for "zonelist cache".  Uses cached zone data to
 * skip over zones that are not allowed by the cpuset, or that have
 * been recently (in last second) found to be nearly full.  See further
 * comments in mmzone.h.  Reduces cache footprint of zonelist scans
S
Simon Arlott 已提交
1249
 * that have to skip over a lot of full or unallowed zones.
1250 1251 1252
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1253
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274
 *
 * If the zonelist cache is not available for this zonelist, does
 * nothing and returns NULL.
 *
 * If the fullzones BITMAP in the zonelist cache is stale (more than
 * a second since last zap'd) then we zap it out (clear its bits.)
 *
 * We hold off even calling zlc_setup, until after we've checked the
 * first zone in the zonelist, on the theory that most allocations will
 * be satisfied from that first zone, so best to examine that zone as
 * quickly as we can.
 */
static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	nodemask_t *allowednodes;	/* zonelist_cache approximation */

	zlc = zonelist->zlcache_ptr;
	if (!zlc)
		return NULL;

S
S.Caglar Onur 已提交
1275
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1276 1277 1278 1279 1280 1281
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1282
					&node_states[N_HIGH_MEMORY];
1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307
	return allowednodes;
}

/*
 * Given 'z' scanning a zonelist, run a couple of quick checks to see
 * if it is worth looking at further for free memory:
 *  1) Check that the zone isn't thought to be full (doesn't have its
 *     bit set in the zonelist_cache fullzones BITMAP).
 *  2) Check that the zones node (obtained from the zonelist_cache
 *     z_to_n[] mapping) is allowed in the passed in allowednodes mask.
 * Return true (non-zero) if zone is worth looking at further, or
 * else return false (zero) if it is not.
 *
 * This check -ignores- the distinction between various watermarks,
 * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ...  If a zone is
 * found to be full for any variation of these watermarks, it will
 * be considered full for up to one second by all requests, unless
 * we are so low on memory on all allowed nodes that we are forced
 * into the second scan of the zonelist.
 *
 * In the second scan we ignore this zonelist cache and exactly
 * apply the watermarks to all zones, even it is slower to do so.
 * We are low on memory in the second scan, and should leave no stone
 * unturned looking for a free page.
 */
1308
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1309 1310 1311 1312 1313 1314 1315 1316 1317 1318
						nodemask_t *allowednodes)
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */
	int n;				/* node that zone *z is on */

	zlc = zonelist->zlcache_ptr;
	if (!zlc)
		return 1;

1319
	i = z - zonelist->_zonerefs;
1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330
	n = zlc->z_to_n[i];

	/* This zone is worth trying if it is allowed but not full */
	return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
}

/*
 * Given 'z' scanning a zonelist, set the corresponding bit in
 * zlc->fullzones, so that subsequent attempts to allocate a page
 * from that zone don't waste time re-examining it.
 */
1331
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1332 1333 1334 1335 1336 1337 1338 1339
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

	zlc = zonelist->zlcache_ptr;
	if (!zlc)
		return;

1340
	i = z - zonelist->_zonerefs;
1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
{
	return NULL;
}

1352
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1353 1354 1355 1356 1357
				nodemask_t *allowednodes)
{
	return 1;
}

1358
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1359 1360 1361 1362
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1363
/*
1364
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1365 1366 1367
 * a page.
 */
static struct page *
1368
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1369
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags)
M
Martin Hicks 已提交
1370
{
1371
	struct zoneref *z;
R
Rohit Seth 已提交
1372
	struct page *page = NULL;
1373
	int classzone_idx;
1374
	struct zone *zone, *preferred_zone;
1375 1376 1377
	nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
	int zlc_active = 0;		/* set if using zonelist_cache */
	int did_zlc_setup = 0;		/* just call zlc_setup() one time */
1378

1379 1380
	(void)first_zones_zonelist(zonelist, high_zoneidx, nodemask,
							&preferred_zone);
1381 1382 1383
	if (!preferred_zone)
		return NULL;

1384
	classzone_idx = zone_idx(preferred_zone);
R
Rohit Seth 已提交
1385

1386
zonelist_scan:
R
Rohit Seth 已提交
1387
	/*
1388
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1389 1390
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1391 1392
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1393 1394 1395
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1396
		if ((alloc_flags & ALLOC_CPUSET) &&
1397
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1398
				goto try_next_zone;
R
Rohit Seth 已提交
1399 1400

		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1401 1402
			unsigned long mark;
			if (alloc_flags & ALLOC_WMARK_MIN)
1403
				mark = zone->pages_min;
1404
			else if (alloc_flags & ALLOC_WMARK_LOW)
1405
				mark = zone->pages_low;
1406
			else
1407
				mark = zone->pages_high;
1408 1409
			if (!zone_watermark_ok(zone, order, mark,
				    classzone_idx, alloc_flags)) {
1410
				if (!zone_reclaim_mode ||
1411
				    !zone_reclaim(zone, gfp_mask, order))
1412
					goto this_zone_full;
1413
			}
R
Rohit Seth 已提交
1414 1415
		}

1416
		page = buffered_rmqueue(preferred_zone, zone, order, gfp_mask);
1417
		if (page)
R
Rohit Seth 已提交
1418
			break;
1419 1420 1421 1422 1423 1424 1425 1426 1427 1428
this_zone_full:
		if (NUMA_BUILD)
			zlc_mark_zone_full(zonelist, z);
try_next_zone:
		if (NUMA_BUILD && !did_zlc_setup) {
			/* we do zlc_setup after the first zone is tried */
			allowednodes = zlc_setup(zonelist, alloc_flags);
			zlc_active = 1;
			did_zlc_setup = 1;
		}
1429
	}
1430 1431 1432 1433 1434 1435

	if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
		/* Disable zlc cache for second zonelist scan */
		zlc_active = 0;
		goto zonelist_scan;
	}
R
Rohit Seth 已提交
1436
	return page;
M
Martin Hicks 已提交
1437 1438
}

L
Linus Torvalds 已提交
1439 1440 1441
/*
 * This is the 'heart' of the zoned buddy allocator.
 */
1442
struct page *
1443 1444
__alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
			struct zonelist *zonelist, nodemask_t *nodemask)
L
Linus Torvalds 已提交
1445
{
A
Al Viro 已提交
1446
	const gfp_t wait = gfp_mask & __GFP_WAIT;
1447
	enum zone_type high_zoneidx = gfp_zone(gfp_mask);
1448 1449
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
1450 1451 1452 1453
	struct page *page;
	struct reclaim_state reclaim_state;
	struct task_struct *p = current;
	int do_retry;
R
Rohit Seth 已提交
1454
	int alloc_flags;
1455 1456
	unsigned long did_some_progress;
	unsigned long pages_reclaimed = 0;
L
Linus Torvalds 已提交
1457 1458 1459

	might_sleep_if(wait);

1460 1461 1462
	if (should_fail_alloc_page(gfp_mask, order))
		return NULL;

1463
restart:
1464
	z = zonelist->_zonerefs;  /* the list of zones suitable for gfp_mask */
L
Linus Torvalds 已提交
1465

1466
	if (unlikely(!z->zone)) {
1467 1468 1469 1470
		/*
		 * Happens if we have an empty zonelist as a result of
		 * GFP_THISNODE being used on a memoryless node
		 */
L
Linus Torvalds 已提交
1471 1472
		return NULL;
	}
1473

1474
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
1475
			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET);
R
Rohit Seth 已提交
1476 1477
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1478

1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489
	/*
	 * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
	 * __GFP_NOWARN set) should not cause reclaim since the subsystem
	 * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
	 * using a larger set of nodes after it has established that the
	 * allowed per node queues are empty and that nodes are
	 * over allocated.
	 */
	if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
		goto nopage;

1490 1491
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
		wakeup_kswapd(zone, order);
L
Linus Torvalds 已提交
1492

1493
	/*
R
Rohit Seth 已提交
1494 1495 1496 1497 1498 1499
	 * OK, we're below the kswapd watermark and have kicked background
	 * reclaim. Now things get more complex, so set up alloc_flags according
	 * to how we want to proceed.
	 *
	 * The caller may dip into page reserves a bit more if the caller
	 * cannot run direct reclaim, or if the caller has realtime scheduling
P
Paul Jackson 已提交
1500 1501
	 * policy or is asking for __GFP_HIGH memory.  GFP_ATOMIC requests will
	 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1502
	 */
1503
	alloc_flags = ALLOC_WMARK_MIN;
R
Rohit Seth 已提交
1504 1505 1506 1507
	if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)
		alloc_flags |= ALLOC_HARDER;
	if (gfp_mask & __GFP_HIGH)
		alloc_flags |= ALLOC_HIGH;
1508 1509
	if (wait)
		alloc_flags |= ALLOC_CPUSET;
L
Linus Torvalds 已提交
1510 1511 1512

	/*
	 * Go through the zonelist again. Let __GFP_HIGH and allocations
R
Rohit Seth 已提交
1513
	 * coming from realtime tasks go deeper into reserves.
L
Linus Torvalds 已提交
1514 1515 1516
	 *
	 * This is the last chance, in general, before the goto nopage.
	 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1517
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
L
Linus Torvalds 已提交
1518
	 */
1519
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1520
						high_zoneidx, alloc_flags);
R
Rohit Seth 已提交
1521 1522
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1523 1524

	/* This allocation should allow future memory freeing. */
1525

1526
rebalance:
1527 1528 1529
	if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
			&& !in_interrupt()) {
		if (!(gfp_mask & __GFP_NOMEMALLOC)) {
K
Kirill Korotaev 已提交
1530
nofail_alloc:
1531
			/* go through the zonelist yet again, ignoring mins */
1532
			page = get_page_from_freelist(gfp_mask, nodemask, order,
1533
				zonelist, high_zoneidx, ALLOC_NO_WATERMARKS);
R
Rohit Seth 已提交
1534 1535
			if (page)
				goto got_pg;
K
Kirill Korotaev 已提交
1536
			if (gfp_mask & __GFP_NOFAIL) {
1537
				congestion_wait(WRITE, HZ/50);
K
Kirill Korotaev 已提交
1538 1539
				goto nofail_alloc;
			}
L
Linus Torvalds 已提交
1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550
		}
		goto nopage;
	}

	/* Atomic allocations - we can't balance anything */
	if (!wait)
		goto nopage;

	cond_resched();

	/* We now go into synchronous reclaim */
1551
	cpuset_memory_pressure_bump();
L
Linus Torvalds 已提交
1552 1553 1554 1555
	p->flags |= PF_MEMALLOC;
	reclaim_state.reclaimed_slab = 0;
	p->reclaim_state = &reclaim_state;

1556
	did_some_progress = try_to_free_pages(zonelist, order, gfp_mask);
L
Linus Torvalds 已提交
1557 1558 1559 1560 1561 1562

	p->reclaim_state = NULL;
	p->flags &= ~PF_MEMALLOC;

	cond_resched();

1563
	if (order != 0)
1564
		drain_all_pages();
1565

L
Linus Torvalds 已提交
1566
	if (likely(did_some_progress)) {
1567
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1568
					zonelist, high_zoneidx, alloc_flags);
R
Rohit Seth 已提交
1569 1570
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
1571
	} else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1572
		if (!try_set_zone_oom(zonelist, gfp_mask)) {
1573 1574 1575 1576
			schedule_timeout_uninterruptible(1);
			goto restart;
		}

L
Linus Torvalds 已提交
1577 1578 1579 1580 1581 1582
		/*
		 * Go through the zonelist yet one more time, keep
		 * very high watermark here, this is only to catch
		 * a parallel oom killing, we must fail if we're still
		 * under heavy pressure.
		 */
1583 1584 1585
		page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
			order, zonelist, high_zoneidx,
			ALLOC_WMARK_HIGH|ALLOC_CPUSET);
1586
		if (page) {
1587
			clear_zonelist_oom(zonelist, gfp_mask);
R
Rohit Seth 已提交
1588
			goto got_pg;
1589
		}
L
Linus Torvalds 已提交
1590

1591
		/* The OOM killer will not help higher order allocs so fail */
1592
		if (order > PAGE_ALLOC_COSTLY_ORDER) {
1593
			clear_zonelist_oom(zonelist, gfp_mask);
1594
			goto nopage;
1595
		}
1596

1597
		out_of_memory(zonelist, gfp_mask, order);
1598
		clear_zonelist_oom(zonelist, gfp_mask);
L
Linus Torvalds 已提交
1599 1600 1601 1602 1603 1604 1605
		goto restart;
	}

	/*
	 * Don't let big-order allocations loop unless the caller explicitly
	 * requests that.  Wait for some write requests to complete then retry.
	 *
1606 1607
	 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
	 * means __GFP_NOFAIL, but that may not be true in other
1608
	 * implementations.
1609 1610 1611 1612 1613 1614
	 *
	 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
	 * specified, then we retry until we no longer reclaim any pages
	 * (above), or we've reclaimed an order of pages at least as
	 * large as the allocation's order. In both cases, if the
	 * allocation still fails, we stop retrying.
L
Linus Torvalds 已提交
1615
	 */
1616
	pages_reclaimed += did_some_progress;
L
Linus Torvalds 已提交
1617 1618
	do_retry = 0;
	if (!(gfp_mask & __GFP_NORETRY)) {
1619
		if (order <= PAGE_ALLOC_COSTLY_ORDER) {
L
Linus Torvalds 已提交
1620
			do_retry = 1;
1621 1622 1623 1624 1625
		} else {
			if (gfp_mask & __GFP_REPEAT &&
				pages_reclaimed < (1 << order))
					do_retry = 1;
		}
L
Linus Torvalds 已提交
1626 1627 1628 1629
		if (gfp_mask & __GFP_NOFAIL)
			do_retry = 1;
	}
	if (do_retry) {
1630
		congestion_wait(WRITE, HZ/50);
L
Linus Torvalds 已提交
1631 1632 1633 1634 1635 1636 1637 1638 1639
		goto rebalance;
	}

nopage:
	if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
		printk(KERN_WARNING "%s: page allocation failure."
			" order:%d, mode:0x%x\n",
			p->comm, order, gfp_mask);
		dump_stack();
J
Janet Morgan 已提交
1640
		show_mem();
L
Linus Torvalds 已提交
1641 1642 1643 1644
	}
got_pg:
	return page;
}
1645
EXPORT_SYMBOL(__alloc_pages_internal);
L
Linus Torvalds 已提交
1646 1647 1648 1649

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
1650
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
1651 1652 1653 1654 1655 1656 1657 1658 1659 1660
{
	struct page * page;
	page = alloc_pages(gfp_mask, order);
	if (!page)
		return 0;
	return (unsigned long) page_address(page);
}

EXPORT_SYMBOL(__get_free_pages);

H
Harvey Harrison 已提交
1661
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
1662 1663 1664 1665 1666 1667 1668
{
	struct page * page;

	/*
	 * get_zeroed_page() returns a 32-bit address, which cannot represent
	 * a highmem page
	 */
N
Nick Piggin 已提交
1669
	VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
L
Linus Torvalds 已提交
1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686

	page = alloc_pages(gfp_mask | __GFP_ZERO, 0);
	if (page)
		return (unsigned long) page_address(page);
	return 0;
}

EXPORT_SYMBOL(get_zeroed_page);

void __pagevec_free(struct pagevec *pvec)
{
	int i = pagevec_count(pvec);

	while (--i >= 0)
		free_hot_cold_page(pvec->pages[i], pvec->cold);
}

H
Harvey Harrison 已提交
1687
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
1688
{
N
Nick Piggin 已提交
1689
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
1690 1691 1692 1693 1694 1695 1696 1697 1698
		if (order == 0)
			free_hot_page(page);
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
1699
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
1700 1701
{
	if (addr != 0) {
N
Nick Piggin 已提交
1702
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
1703 1704 1705 1706 1707 1708
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761
/**
 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
 * @size: the number of bytes to allocate
 * @gfp_mask: GFP flags for the allocation
 *
 * This function is similar to alloc_pages(), except that it allocates the
 * minimum number of pages to satisfy the request.  alloc_pages() can only
 * allocate memory in power-of-two pages.
 *
 * This function is also limited by MAX_ORDER.
 *
 * Memory allocated by this function must be released by free_pages_exact().
 */
void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
{
	unsigned int order = get_order(size);
	unsigned long addr;

	addr = __get_free_pages(gfp_mask, order);
	if (addr) {
		unsigned long alloc_end = addr + (PAGE_SIZE << order);
		unsigned long used = addr + PAGE_ALIGN(size);

		split_page(virt_to_page(addr), order);
		while (used < alloc_end) {
			free_page(used);
			used += PAGE_SIZE;
		}
	}

	return (void *)addr;
}
EXPORT_SYMBOL(alloc_pages_exact);

/**
 * free_pages_exact - release memory allocated via alloc_pages_exact()
 * @virt: the value returned by alloc_pages_exact.
 * @size: size of allocation, same value as passed to alloc_pages_exact().
 *
 * Release the memory allocated by a previous call to alloc_pages_exact.
 */
void free_pages_exact(void *virt, size_t size)
{
	unsigned long addr = (unsigned long)virt;
	unsigned long end = addr + PAGE_ALIGN(size);

	while (addr < end) {
		free_page(addr);
		addr += PAGE_SIZE;
	}
}
EXPORT_SYMBOL(free_pages_exact);

L
Linus Torvalds 已提交
1762 1763
static unsigned int nr_free_zone_pages(int offset)
{
1764
	struct zoneref *z;
1765 1766
	struct zone *zone;

1767
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
1768 1769
	unsigned int sum = 0;

1770
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
1771

1772
	for_each_zone_zonelist(zone, z, zonelist, offset) {
1773 1774 1775 1776
		unsigned long size = zone->present_pages;
		unsigned long high = zone->pages_high;
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
1777 1778 1779 1780 1781 1782 1783 1784 1785 1786
	}

	return sum;
}

/*
 * Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
 */
unsigned int nr_free_buffer_pages(void)
{
A
Al Viro 已提交
1787
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
1788
}
1789
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
1790 1791 1792 1793 1794 1795

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
1796
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
1797
}
1798 1799

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
1800
{
1801
	if (NUMA_BUILD)
1802
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
1803 1804 1805 1806 1807 1808
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
1809
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823
	val->bufferram = nr_blockdev_pages();
	val->totalhigh = totalhigh_pages;
	val->freehigh = nr_free_highpages();
	val->mem_unit = PAGE_SIZE;
}

EXPORT_SYMBOL(si_meminfo);

#ifdef CONFIG_NUMA
void si_meminfo_node(struct sysinfo *val, int nid)
{
	pg_data_t *pgdat = NODE_DATA(nid);

	val->totalram = pgdat->node_present_pages;
1824
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
1825
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
1826
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
1827 1828
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
1829 1830 1831 1832
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845
	val->mem_unit = PAGE_SIZE;
}
#endif

#define K(x) ((x) << (PAGE_SHIFT-10))

/*
 * Show free area list (used inside shift_scroll-lock stuff)
 * We also calculate the percentage fragmentation. We do this by counting the
 * memory on each free list with the exception of the first item on the list.
 */
void show_free_areas(void)
{
1846
	int cpu;
L
Linus Torvalds 已提交
1847 1848 1849
	struct zone *zone;

	for_each_zone(zone) {
1850
		if (!populated_zone(zone))
L
Linus Torvalds 已提交
1851
			continue;
1852 1853 1854

		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
1855

1856
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
1857 1858
			struct per_cpu_pageset *pageset;

1859
			pageset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
1860

1861 1862 1863
			printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
			       cpu, pageset->pcp.high,
			       pageset->pcp.batch, pageset->pcp.count);
L
Linus Torvalds 已提交
1864 1865 1866
		}
	}

1867 1868
	printk("Active_anon:%lu active_file:%lu inactive_anon%lu\n"
		" inactive_file:%lu dirty:%lu writeback:%lu unstable:%lu\n"
1869
		" free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
1870 1871 1872 1873
		global_page_state(NR_ACTIVE_ANON),
		global_page_state(NR_ACTIVE_FILE),
		global_page_state(NR_INACTIVE_ANON),
		global_page_state(NR_INACTIVE_FILE),
1874
		global_page_state(NR_FILE_DIRTY),
1875
		global_page_state(NR_WRITEBACK),
1876
		global_page_state(NR_UNSTABLE_NFS),
1877
		global_page_state(NR_FREE_PAGES),
1878 1879
		global_page_state(NR_SLAB_RECLAIMABLE) +
			global_page_state(NR_SLAB_UNRECLAIMABLE),
1880
		global_page_state(NR_FILE_MAPPED),
1881 1882
		global_page_state(NR_PAGETABLE),
		global_page_state(NR_BOUNCE));
L
Linus Torvalds 已提交
1883 1884 1885 1886

	for_each_zone(zone) {
		int i;

1887 1888 1889
		if (!populated_zone(zone))
			continue;

L
Linus Torvalds 已提交
1890 1891 1892 1893 1894 1895
		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
1896 1897 1898 1899
			" active_anon:%lukB"
			" inactive_anon:%lukB"
			" active_file:%lukB"
			" inactive_file:%lukB"
L
Linus Torvalds 已提交
1900 1901 1902 1903 1904
			" present:%lukB"
			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
1905
			K(zone_page_state(zone, NR_FREE_PAGES)),
L
Linus Torvalds 已提交
1906 1907 1908
			K(zone->pages_min),
			K(zone->pages_low),
			K(zone->pages_high),
1909 1910 1911 1912
			K(zone_page_state(zone, NR_ACTIVE_ANON)),
			K(zone_page_state(zone, NR_INACTIVE_ANON)),
			K(zone_page_state(zone, NR_ACTIVE_FILE)),
			K(zone_page_state(zone, NR_INACTIVE_FILE)),
L
Linus Torvalds 已提交
1913 1914
			K(zone->present_pages),
			zone->pages_scanned,
1915
			(zone_is_all_unreclaimable(zone) ? "yes" : "no")
L
Linus Torvalds 已提交
1916 1917 1918 1919 1920 1921 1922 1923
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

	for_each_zone(zone) {
1924
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
L
Linus Torvalds 已提交
1925

1926 1927 1928
		if (!populated_zone(zone))
			continue;

L
Linus Torvalds 已提交
1929 1930 1931 1932 1933
		show_node(zone);
		printk("%s: ", zone->name);

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
1934 1935
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
L
Linus Torvalds 已提交
1936 1937
		}
		spin_unlock_irqrestore(&zone->lock, flags);
1938 1939
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
L
Linus Torvalds 已提交
1940 1941 1942
		printk("= %lukB\n", K(total));
	}

1943 1944
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

L
Linus Torvalds 已提交
1945 1946 1947
	show_swap_cache_info();
}

1948 1949 1950 1951 1952 1953
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
{
	zoneref->zone = zone;
	zoneref->zone_idx = zone_idx(zone);
}

L
Linus Torvalds 已提交
1954 1955
/*
 * Builds allocation fallback zone lists.
1956 1957
 *
 * Add all populated zones of a node to the zonelist.
L
Linus Torvalds 已提交
1958
 */
1959 1960
static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
				int nr_zones, enum zone_type zone_type)
L
Linus Torvalds 已提交
1961
{
1962 1963
	struct zone *zone;

1964
	BUG_ON(zone_type >= MAX_NR_ZONES);
1965
	zone_type++;
1966 1967

	do {
1968
		zone_type--;
1969
		zone = pgdat->node_zones + zone_type;
1970
		if (populated_zone(zone)) {
1971 1972
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
1973
			check_highest_zone(zone_type);
L
Linus Torvalds 已提交
1974
		}
1975

1976
	} while (zone_type);
1977
	return nr_zones;
L
Linus Torvalds 已提交
1978 1979
}

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

/*
 *  zonelist_order:
 *  0 = automatic detection of better ordering.
 *  1 = order by ([node] distance, -zonetype)
 *  2 = order by (-zonetype, [node] distance)
 *
 *  If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
 *  the same zonelist. So only NUMA can configure this param.
 */
#define ZONELIST_ORDER_DEFAULT  0
#define ZONELIST_ORDER_NODE     1
#define ZONELIST_ORDER_ZONE     2

/* zonelist order in the kernel.
 * set_zonelist_order() will set this to NODE or ZONE.
 */
static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};


L
Linus Torvalds 已提交
2001
#ifdef CONFIG_NUMA
2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072
/* The value user specified ....changed by config */
static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
/* string for sysctl */
#define NUMA_ZONELIST_ORDER_LEN	16
char numa_zonelist_order[16] = "default";

/*
 * interface for configure zonelist ordering.
 * command line option "numa_zonelist_order"
 *	= "[dD]efault	- default, automatic configuration.
 *	= "[nN]ode 	- order by node locality, then by zone within node
 *	= "[zZ]one      - order by zone, then by locality within zone
 */

static int __parse_numa_zonelist_order(char *s)
{
	if (*s == 'd' || *s == 'D') {
		user_zonelist_order = ZONELIST_ORDER_DEFAULT;
	} else if (*s == 'n' || *s == 'N') {
		user_zonelist_order = ZONELIST_ORDER_NODE;
	} else if (*s == 'z' || *s == 'Z') {
		user_zonelist_order = ZONELIST_ORDER_ZONE;
	} else {
		printk(KERN_WARNING
			"Ignoring invalid numa_zonelist_order value:  "
			"%s\n", s);
		return -EINVAL;
	}
	return 0;
}

static __init int setup_numa_zonelist_order(char *s)
{
	if (s)
		return __parse_numa_zonelist_order(s);
	return 0;
}
early_param("numa_zonelist_order", setup_numa_zonelist_order);

/*
 * sysctl handler for numa_zonelist_order
 */
int numa_zonelist_order_handler(ctl_table *table, int write,
		struct file *file, void __user *buffer, size_t *length,
		loff_t *ppos)
{
	char saved_string[NUMA_ZONELIST_ORDER_LEN];
	int ret;

	if (write)
		strncpy(saved_string, (char*)table->data,
			NUMA_ZONELIST_ORDER_LEN);
	ret = proc_dostring(table, write, file, buffer, length, ppos);
	if (ret)
		return ret;
	if (write) {
		int oldval = user_zonelist_order;
		if (__parse_numa_zonelist_order((char*)table->data)) {
			/*
			 * bogus value.  restore saved string
			 */
			strncpy((char*)table->data, saved_string,
				NUMA_ZONELIST_ORDER_LEN);
			user_zonelist_order = oldval;
		} else if (oldval != user_zonelist_order)
			build_all_zonelists();
	}
	return 0;
}


L
Linus Torvalds 已提交
2073
#define MAX_NODE_LOAD (num_online_nodes())
2074 2075
static int node_load[MAX_NUMNODES];

L
Linus Torvalds 已提交
2076
/**
2077
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
Linus Torvalds 已提交
2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089
 * @node: node whose fallback list we're appending
 * @used_node_mask: nodemask_t of already used nodes
 *
 * We use a number of factors to determine which is the next node that should
 * appear on a given node's fallback list.  The node should not have appeared
 * already in @node's fallback list, and it should be the next closest node
 * according to the distance array (which contains arbitrary distance values
 * from each node to each node in the system), and should also prefer nodes
 * with no CPUs, since presumably they'll have very little allocation pressure
 * on them otherwise.
 * It returns -1 if no node is found.
 */
2090
static int find_next_best_node(int node, nodemask_t *used_node_mask)
L
Linus Torvalds 已提交
2091
{
2092
	int n, val;
L
Linus Torvalds 已提交
2093 2094
	int min_val = INT_MAX;
	int best_node = -1;
2095
	node_to_cpumask_ptr(tmp, 0);
L
Linus Torvalds 已提交
2096

2097 2098 2099 2100 2101
	/* Use the local node if we haven't already */
	if (!node_isset(node, *used_node_mask)) {
		node_set(node, *used_node_mask);
		return node;
	}
L
Linus Torvalds 已提交
2102

2103
	for_each_node_state(n, N_HIGH_MEMORY) {
L
Linus Torvalds 已提交
2104 2105 2106 2107 2108 2109 2110 2111

		/* Don't want a node to appear more than once */
		if (node_isset(n, *used_node_mask))
			continue;

		/* Use the distance array to find the distance */
		val = node_distance(node, n);

2112 2113 2114
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
Linus Torvalds 已提交
2115
		/* Give preference to headless and unused nodes */
2116 2117
		node_to_cpumask_ptr_next(tmp, n);
		if (!cpus_empty(*tmp))
L
Linus Torvalds 已提交
2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135
			val += PENALTY_FOR_NODE_WITH_CPUS;

		/* Slight preference for less loaded node */
		val *= (MAX_NODE_LOAD*MAX_NUMNODES);
		val += node_load[n];

		if (val < min_val) {
			min_val = val;
			best_node = n;
		}
	}

	if (best_node >= 0)
		node_set(best_node, *used_node_mask);

	return best_node;
}

2136 2137 2138 2139 2140 2141 2142

/*
 * Build zonelists ordered by node and zones within node.
 * This results in maximum locality--normal zone overflows into local
 * DMA zone, if any--but risks exhausting DMA zone.
 */
static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
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2143
{
2144
	int j;
L
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2145
	struct zonelist *zonelist;
2146

2147
	zonelist = &pgdat->node_zonelists[0];
2148
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2149 2150 2151
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
2152 2153
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2154 2155
}

2156 2157 2158 2159 2160 2161 2162 2163
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

2164 2165
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2166 2167
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2168 2169
}

2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184
/*
 * Build zonelists ordered by zone and nodes within zones.
 * This results in conserving DMA zone[s] until all Normal memory is
 * exhausted, but results in overflowing to remote node while memory
 * may still exist in local DMA zone.
 */
static int node_order[MAX_NUMNODES];

static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
{
	int pos, j, node;
	int zone_type;		/* needs to be signed */
	struct zone *z;
	struct zonelist *zonelist;

2185 2186 2187 2188 2189 2190 2191
	zonelist = &pgdat->node_zonelists[0];
	pos = 0;
	for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
		for (j = 0; j < nr_nodes; j++) {
			node = node_order[j];
			z = &NODE_DATA(node)->node_zones[zone_type];
			if (populated_zone(z)) {
2192 2193
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
2194
				check_highest_zone(zone_type);
2195 2196 2197
			}
		}
	}
2198 2199
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234
}

static int default_zonelist_order(void)
{
	int nid, zone_type;
	unsigned long low_kmem_size,total_size;
	struct zone *z;
	int average_size;
	/*
         * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
	 * If they are really small and used heavily, the system can fall
	 * into OOM very easily.
	 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
	 */
	/* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
	low_kmem_size = 0;
	total_size = 0;
	for_each_online_node(nid) {
		for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
			z = &NODE_DATA(nid)->node_zones[zone_type];
			if (populated_zone(z)) {
				if (zone_type < ZONE_NORMAL)
					low_kmem_size += z->present_pages;
				total_size += z->present_pages;
			}
		}
	}
	if (!low_kmem_size ||  /* there are no DMA area. */
	    low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
		return ZONELIST_ORDER_NODE;
	/*
	 * look into each node's config.
  	 * If there is a node whose DMA/DMA32 memory is very big area on
 	 * local memory, NODE_ORDER may be suitable.
         */
2235 2236
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267
	for_each_online_node(nid) {
		low_kmem_size = 0;
		total_size = 0;
		for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
			z = &NODE_DATA(nid)->node_zones[zone_type];
			if (populated_zone(z)) {
				if (zone_type < ZONE_NORMAL)
					low_kmem_size += z->present_pages;
				total_size += z->present_pages;
			}
		}
		if (low_kmem_size &&
		    total_size > average_size && /* ignore small node */
		    low_kmem_size > total_size * 70/100)
			return ZONELIST_ORDER_NODE;
	}
	return ZONELIST_ORDER_ZONE;
}

static void set_zonelist_order(void)
{
	if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
		current_zonelist_order = default_zonelist_order();
	else
		current_zonelist_order = user_zonelist_order;
}

static void build_zonelists(pg_data_t *pgdat)
{
	int j, node, load;
	enum zone_type i;
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2268
	nodemask_t used_mask;
2269 2270 2271
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
L
Linus Torvalds 已提交
2272 2273

	/* initialize zonelists */
2274
	for (i = 0; i < MAX_ZONELISTS; i++) {
L
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2275
		zonelist = pgdat->node_zonelists + i;
2276 2277
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
L
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2278 2279 2280 2281 2282 2283 2284
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
	load = num_online_nodes();
	prev_node = local_node;
	nodes_clear(used_mask);
2285 2286 2287 2288 2289

	memset(node_load, 0, sizeof(node_load));
	memset(node_order, 0, sizeof(node_order));
	j = 0;

L
Linus Torvalds 已提交
2290
	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2291 2292 2293 2294 2295 2296 2297 2298 2299
		int distance = node_distance(local_node, node);

		/*
		 * If another node is sufficiently far away then it is better
		 * to reclaim pages in a zone before going off node.
		 */
		if (distance > RECLAIM_DISTANCE)
			zone_reclaim_mode = 1;

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2300 2301 2302 2303 2304
		/*
		 * We don't want to pressure a particular node.
		 * So adding penalty to the first node in same
		 * distance group to make it round-robin.
		 */
2305
		if (distance != node_distance(local_node, prev_node))
2306 2307
			node_load[node] = load;

L
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2308 2309
		prev_node = node;
		load--;
2310 2311 2312 2313 2314
		if (order == ZONELIST_ORDER_NODE)
			build_zonelists_in_node_order(pgdat, node);
		else
			node_order[j++] = node;	/* remember order */
	}
L
Linus Torvalds 已提交
2315

2316 2317 2318
	if (order == ZONELIST_ORDER_ZONE) {
		/* calculate node order -- i.e., DMA last! */
		build_zonelists_in_zone_order(pgdat, j);
L
Linus Torvalds 已提交
2319
	}
2320 2321

	build_thisnode_zonelists(pgdat);
L
Linus Torvalds 已提交
2322 2323
}

2324
/* Construct the zonelist performance cache - see further mmzone.h */
2325
static void build_zonelist_cache(pg_data_t *pgdat)
2326
{
2327 2328
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
2329
	struct zoneref *z;
2330

2331 2332 2333
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2334 2335
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2336 2337
}

2338

L
Linus Torvalds 已提交
2339 2340
#else	/* CONFIG_NUMA */

2341 2342 2343 2344 2345 2346
static void set_zonelist_order(void)
{
	current_zonelist_order = ZONELIST_ORDER_ZONE;
}

static void build_zonelists(pg_data_t *pgdat)
L
Linus Torvalds 已提交
2347
{
2348
	int node, local_node;
2349 2350
	enum zone_type j;
	struct zonelist *zonelist;
L
Linus Torvalds 已提交
2351 2352 2353

	local_node = pgdat->node_id;

2354 2355
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
2356

2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369
	/*
	 * Now we build the zonelist so that it contains the zones
	 * of all the other nodes.
	 * We don't want to pressure a particular node, so when
	 * building the zones for node N, we make sure that the
	 * zones coming right after the local ones are those from
	 * node N+1 (modulo N)
	 */
	for (node = local_node + 1; node < MAX_NUMNODES; node++) {
		if (!node_online(node))
			continue;
		j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
2370
	}
2371 2372 2373 2374 2375 2376 2377
	for (node = 0; node < local_node; node++) {
		if (!node_online(node))
			continue;
		j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
	}

2378 2379
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
L
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2380 2381
}

2382
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2383
static void build_zonelist_cache(pg_data_t *pgdat)
2384
{
2385
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
2386 2387
}

L
Linus Torvalds 已提交
2388 2389
#endif	/* CONFIG_NUMA */

2390
/* return values int ....just for stop_machine() */
2391
static int __build_all_zonelists(void *dummy)
L
Linus Torvalds 已提交
2392
{
2393
	int nid;
2394 2395

	for_each_online_node(nid) {
2396 2397 2398 2399
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
2400
	}
2401 2402 2403
	return 0;
}

2404
void build_all_zonelists(void)
2405
{
2406 2407
	set_zonelist_order();

2408
	if (system_state == SYSTEM_BOOTING) {
2409
		__build_all_zonelists(NULL);
2410
		mminit_verify_zonelist();
2411 2412
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
2413
		/* we have to stop all cpus to guarantee there is no user
2414
		   of zonelist */
2415
		stop_machine(__build_all_zonelists, NULL, NULL);
2416 2417
		/* cpuset refresh routine should be here */
	}
2418
	vm_total_pages = nr_free_pagecache_pages();
2419 2420 2421 2422 2423 2424 2425
	/*
	 * Disable grouping by mobility if the number of pages in the
	 * system is too low to allow the mechanism to work. It would be
	 * more accurate, but expensive to check per-zone. This check is
	 * made on memory-hotadd so a system can start with mobility
	 * disabled and enable it later
	 */
2426
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2427 2428 2429 2430 2431 2432
		page_group_by_mobility_disabled = 1;
	else
		page_group_by_mobility_disabled = 0;

	printk("Built %i zonelists in %s order, mobility grouping %s.  "
		"Total pages: %ld\n",
2433 2434
			num_online_nodes(),
			zonelist_order_name[current_zonelist_order],
2435
			page_group_by_mobility_disabled ? "off" : "on",
2436 2437 2438 2439
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
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Linus Torvalds 已提交
2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454
}

/*
 * Helper functions to size the waitqueue hash table.
 * Essentially these want to choose hash table sizes sufficiently
 * large so that collisions trying to wait on pages are rare.
 * But in fact, the number of active page waitqueues on typical
 * systems is ridiculously low, less than 200. So this is even
 * conservative, even though it seems large.
 *
 * The constant PAGES_PER_WAITQUEUE specifies the ratio of pages to
 * waitqueues, i.e. the size of the waitq table given the number of pages.
 */
#define PAGES_PER_WAITQUEUE	256

2455
#ifndef CONFIG_MEMORY_HOTPLUG
2456
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473
{
	unsigned long size = 1;

	pages /= PAGES_PER_WAITQUEUE;

	while (size < pages)
		size <<= 1;

	/*
	 * Once we have dozens or even hundreds of threads sleeping
	 * on IO we've got bigger problems than wait queue collision.
	 * Limit the size of the wait table to a reasonable size.
	 */
	size = min(size, 4096UL);

	return max(size, 4UL);
}
2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496
#else
/*
 * A zone's size might be changed by hot-add, so it is not possible to determine
 * a suitable size for its wait_table.  So we use the maximum size now.
 *
 * The max wait table size = 4096 x sizeof(wait_queue_head_t).   ie:
 *
 *    i386 (preemption config)    : 4096 x 16 = 64Kbyte.
 *    ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
 *    ia64, x86-64 (preemption)   : 4096 x 24 = 96Kbyte.
 *
 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
 * or more by the traditional way. (See above).  It equals:
 *
 *    i386, x86-64, powerpc(4K page size) : =  ( 2G + 1M)byte.
 *    ia64(16K page size)                 : =  ( 8G + 4M)byte.
 *    powerpc (64K page size)             : =  (32G +16M)byte.
 */
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
{
	return 4096UL;
}
#endif
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Linus Torvalds 已提交
2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509

/*
 * This is an integer logarithm so that shifts can be used later
 * to extract the more random high bits from the multiplicative
 * hash function before the remainder is taken.
 */
static inline unsigned long wait_table_bits(unsigned long size)
{
	return ffz(~size);
}

#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))

2510
/*
2511
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525
 * of blocks reserved is based on zone->pages_min. The memory within the
 * reserve will tend to store contiguous free pages. Setting min_free_kbytes
 * higher will lead to a bigger reserve which will get freed as contiguous
 * blocks as reclaim kicks in
 */
static void setup_zone_migrate_reserve(struct zone *zone)
{
	unsigned long start_pfn, pfn, end_pfn;
	struct page *page;
	unsigned long reserve, block_migratetype;

	/* Get the start pfn, end pfn and the number of blocks to reserve */
	start_pfn = zone->zone_start_pfn;
	end_pfn = start_pfn + zone->spanned_pages;
2526 2527
	reserve = roundup(zone->pages_min, pageblock_nr_pages) >>
							pageblock_order;
2528

2529
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2530 2531 2532 2533
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

2534 2535 2536 2537
		/* Watch out for overlapping nodes */
		if (page_to_nid(page) != zone_to_nid(zone))
			continue;

2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567
		/* Blocks with reserved pages will never free, skip them. */
		if (PageReserved(page))
			continue;

		block_migratetype = get_pageblock_migratetype(page);

		/* If this block is reserved, account for it */
		if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) {
			reserve--;
			continue;
		}

		/* Suitable for reserving if this block is movable */
		if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) {
			set_pageblock_migratetype(page, MIGRATE_RESERVE);
			move_freepages_block(zone, page, MIGRATE_RESERVE);
			reserve--;
			continue;
		}

		/*
		 * If the reserve is met and this is a previous reserved block,
		 * take it back
		 */
		if (block_migratetype == MIGRATE_RESERVE) {
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
			move_freepages_block(zone, page, MIGRATE_MOVABLE);
		}
	}
}
M
Mel Gorman 已提交
2568

L
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2569 2570 2571 2572 2573
/*
 * Initially all pages are reserved - free ones are freed
 * up by free_all_bootmem() once the early boot process is
 * done. Non-atomic initialization, single-pass.
 */
2574
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
2575
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
2576 2577
{
	struct page *page;
A
Andy Whitcroft 已提交
2578 2579
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
2580
	struct zone *z;
L
Linus Torvalds 已提交
2581

2582
	z = &NODE_DATA(nid)->node_zones[zone];
2583
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594
		/*
		 * There can be holes in boot-time mem_map[]s
		 * handed to this function.  They do not
		 * exist on hotplugged memory.
		 */
		if (context == MEMMAP_EARLY) {
			if (!early_pfn_valid(pfn))
				continue;
			if (!early_pfn_in_nid(pfn, nid))
				continue;
		}
A
Andy Whitcroft 已提交
2595 2596
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
2597
		mminit_verify_page_links(page, zone, nid, pfn);
2598
		init_page_count(page);
L
Linus Torvalds 已提交
2599 2600
		reset_page_mapcount(page);
		SetPageReserved(page);
2601 2602 2603 2604 2605
		/*
		 * Mark the block movable so that blocks are reserved for
		 * movable at startup. This will force kernel allocations
		 * to reserve their blocks rather than leaking throughout
		 * the address space during boot when many long-lived
2606 2607 2608
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
2609 2610 2611 2612 2613
		 *
		 * bitmap is created for zone's valid pfn range. but memmap
		 * can be created for invalid pages (for alignment)
		 * check here not to call set_pageblock_migratetype() against
		 * pfn out of zone.
2614
		 */
2615 2616 2617
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
2618
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2619

L
Linus Torvalds 已提交
2620 2621 2622 2623
		INIT_LIST_HEAD(&page->lru);
#ifdef WANT_PAGE_VIRTUAL
		/* The shift won't overflow because ZONE_NORMAL is below 4G. */
		if (!is_highmem_idx(zone))
2624
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
2625 2626 2627 2628
#endif
	}
}

2629
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
2630
{
2631 2632 2633
	int order, t;
	for_each_migratetype_order(order, t) {
		INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
L
Linus Torvalds 已提交
2634 2635 2636 2637 2638 2639
		zone->free_area[order].nr_free = 0;
	}
}

#ifndef __HAVE_ARCH_MEMMAP_INIT
#define memmap_init(size, nid, zone, start_pfn) \
D
Dave Hansen 已提交
2640
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
2641 2642
#endif

2643
static int zone_batchsize(struct zone *zone)
2644 2645 2646 2647 2648
{
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
2649
	 * size of the zone.  But no more than 1/2 of a meg.
2650 2651 2652 2653
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
2654 2655
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
2656 2657 2658 2659 2660
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
2661 2662 2663
	 * Clamp the batch to a 2^n - 1 value. Having a power
	 * of 2 value was found to be more likely to have
	 * suboptimal cache aliasing properties in some cases.
2664
	 *
2665 2666 2667 2668
	 * For example if 2 tasks are alternately allocating
	 * batches of pages, one task can end up with a lot
	 * of pages of one half of the possible page colors
	 * and the other with pages of the other colors.
2669
	 */
2670
	batch = (1 << (fls(batch + batch/2)-1)) - 1;
2671

2672 2673 2674
	return batch;
}

A
Adrian Bunk 已提交
2675
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
2676 2677 2678
{
	struct per_cpu_pages *pcp;

2679 2680
	memset(p, 0, sizeof(*p));

2681
	pcp = &p->pcp;
2682 2683 2684 2685 2686 2687
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
	INIT_LIST_HEAD(&pcp->list);
}

2688 2689 2690 2691 2692 2693 2694 2695 2696 2697
/*
 * setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
 * to the value high for the pageset p.
 */

static void setup_pagelist_highmark(struct per_cpu_pageset *p,
				unsigned long high)
{
	struct per_cpu_pages *pcp;

2698
	pcp = &p->pcp;
2699 2700 2701 2702 2703 2704 2705
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}


2706 2707
#ifdef CONFIG_NUMA
/*
2708 2709 2710 2711 2712 2713 2714
 * Boot pageset table. One per cpu which is going to be used for all
 * zones and all nodes. The parameters will be set in such a way
 * that an item put on a list will immediately be handed over to
 * the buddy list. This is safe since pageset manipulation is done
 * with interrupts disabled.
 *
 * Some NUMA counter updates may also be caught by the boot pagesets.
2715 2716 2717 2718 2719 2720 2721 2722
 *
 * The boot_pagesets must be kept even after bootup is complete for
 * unused processors and/or zones. They do play a role for bootstrapping
 * hotplugged processors.
 *
 * zoneinfo_show() and maybe other functions do
 * not check if the processor is online before following the pageset pointer.
 * Other parts of the kernel may not check if the zone is available.
2723
 */
2724
static struct per_cpu_pageset boot_pageset[NR_CPUS];
2725 2726 2727

/*
 * Dynamically allocate memory for the
2728 2729
 * per cpu pageset array in struct zone.
 */
2730
static int __cpuinit process_zones(int cpu)
2731 2732
{
	struct zone *zone, *dzone;
2733 2734 2735
	int node = cpu_to_node(cpu);

	node_set_state(node, N_CPU);	/* this node has a cpu */
2736 2737 2738

	for_each_zone(zone) {

2739 2740 2741
		if (!populated_zone(zone))
			continue;

N
Nick Piggin 已提交
2742
		zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
2743
					 GFP_KERNEL, node);
N
Nick Piggin 已提交
2744
		if (!zone_pcp(zone, cpu))
2745 2746
			goto bad;

N
Nick Piggin 已提交
2747
		setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
2748 2749 2750 2751

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(zone_pcp(zone, cpu),
			 	(zone->present_pages / percpu_pagelist_fraction));
2752 2753 2754 2755 2756
	}

	return 0;
bad:
	for_each_zone(dzone) {
2757 2758
		if (!populated_zone(dzone))
			continue;
2759 2760
		if (dzone == zone)
			break;
N
Nick Piggin 已提交
2761 2762
		kfree(zone_pcp(dzone, cpu));
		zone_pcp(dzone, cpu) = NULL;
2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773
	}
	return -ENOMEM;
}

static inline void free_zone_pagesets(int cpu)
{
	struct zone *zone;

	for_each_zone(zone) {
		struct per_cpu_pageset *pset = zone_pcp(zone, cpu);

2774 2775 2776
		/* Free per_cpu_pageset if it is slab allocated */
		if (pset != &boot_pageset[cpu])
			kfree(pset);
2777 2778 2779 2780
		zone_pcp(zone, cpu) = NULL;
	}
}

2781
static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
2782 2783 2784 2785 2786 2787 2788
		unsigned long action,
		void *hcpu)
{
	int cpu = (long)hcpu;
	int ret = NOTIFY_OK;

	switch (action) {
2789
	case CPU_UP_PREPARE:
2790
	case CPU_UP_PREPARE_FROZEN:
2791 2792 2793 2794
		if (process_zones(cpu))
			ret = NOTIFY_BAD;
		break;
	case CPU_UP_CANCELED:
2795
	case CPU_UP_CANCELED_FROZEN:
2796
	case CPU_DEAD:
2797
	case CPU_DEAD_FROZEN:
2798 2799 2800 2801
		free_zone_pagesets(cpu);
		break;
	default:
		break;
2802 2803 2804 2805
	}
	return ret;
}

2806
static struct notifier_block __cpuinitdata pageset_notifier =
2807 2808
	{ &pageset_cpuup_callback, NULL, 0 };

2809
void __init setup_per_cpu_pageset(void)
2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823
{
	int err;

	/* Initialize per_cpu_pageset for cpu 0.
	 * A cpuup callback will do this for every cpu
	 * as it comes online
	 */
	err = process_zones(smp_processor_id());
	BUG_ON(err);
	register_cpu_notifier(&pageset_notifier);
}

#endif

S
Sam Ravnborg 已提交
2824
static noinline __init_refok
2825
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
2826 2827 2828
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
2829
	size_t alloc_size;
2830 2831 2832 2833 2834

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
2835 2836 2837 2838
	zone->wait_table_hash_nr_entries =
		 wait_table_hash_nr_entries(zone_size_pages);
	zone->wait_table_bits =
		wait_table_bits(zone->wait_table_hash_nr_entries);
2839 2840 2841
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

2842
	if (!slab_is_available()) {
2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855
		zone->wait_table = (wait_queue_head_t *)
			alloc_bootmem_node(pgdat, alloc_size);
	} else {
		/*
		 * This case means that a zone whose size was 0 gets new memory
		 * via memory hot-add.
		 * But it may be the case that a new node was hot-added.  In
		 * this case vmalloc() will not be able to use this new node's
		 * memory - this wait_table must be initialized to use this new
		 * node itself as well.
		 * To use this new node's memory, further consideration will be
		 * necessary.
		 */
2856
		zone->wait_table = vmalloc(alloc_size);
2857 2858 2859
	}
	if (!zone->wait_table)
		return -ENOMEM;
2860

2861
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
2862
		init_waitqueue_head(zone->wait_table + i);
2863 2864

	return 0;
2865 2866
}

2867
static __meminit void zone_pcp_init(struct zone *zone)
2868 2869 2870 2871 2872 2873 2874
{
	int cpu;
	unsigned long batch = zone_batchsize(zone);

	for (cpu = 0; cpu < NR_CPUS; cpu++) {
#ifdef CONFIG_NUMA
		/* Early boot. Slab allocator not functional yet */
N
Nick Piggin 已提交
2875
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
2876 2877 2878 2879 2880
		setup_pageset(&boot_pageset[cpu],0);
#else
		setup_pageset(zone_pcp(zone,cpu), batch);
#endif
	}
A
Anton Blanchard 已提交
2881 2882 2883
	if (zone->present_pages)
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%lu\n",
			zone->name, zone->present_pages, batch);
2884 2885
}

2886 2887
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
2888 2889
					unsigned long size,
					enum memmap_context context)
2890 2891
{
	struct pglist_data *pgdat = zone->zone_pgdat;
2892 2893 2894 2895
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
2896 2897 2898 2899
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

2900 2901 2902 2903 2904 2905
	mminit_dprintk(MMINIT_TRACE, "memmap_init",
			"Initialising map node %d zone %lu pfns %lu -> %lu\n",
			pgdat->node_id,
			(unsigned long)zone_idx(zone),
			zone_start_pfn, (zone_start_pfn + size));

2906
	zone_init_free_lists(zone);
2907 2908

	return 0;
2909 2910
}

2911 2912 2913 2914 2915
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
/*
 * Basic iterator support. Return the first range of PFNs for a node
 * Note: nid == MAX_NUMNODES returns first region regardless of node
 */
2916
static int __meminit first_active_region_index_in_nid(int nid)
2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928
{
	int i;

	for (i = 0; i < nr_nodemap_entries; i++)
		if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
			return i;

	return -1;
}

/*
 * Basic iterator support. Return the next active range of PFNs for a node
S
Simon Arlott 已提交
2929
 * Note: nid == MAX_NUMNODES returns next region regardless of node
2930
 */
2931
static int __meminit next_active_region_index_in_nid(int index, int nid)
2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946
{
	for (index = index + 1; index < nr_nodemap_entries; index++)
		if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
			return index;

	return -1;
}

#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
/*
 * Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
 * Architectures may implement their own version but if add_active_range()
 * was used and there are no special requirements, this is a convenient
 * alternative
 */
2947
int __meminit early_pfn_to_nid(unsigned long pfn)
2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969
{
	int i;

	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long start_pfn = early_node_map[i].start_pfn;
		unsigned long end_pfn = early_node_map[i].end_pfn;

		if (start_pfn <= pfn && pfn < end_pfn)
			return early_node_map[i].nid;
	}

	return 0;
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

/* Basic iterator support to walk early_node_map[] */
#define for_each_active_range_index_in_nid(i, nid) \
	for (i = first_active_region_index_in_nid(nid); i != -1; \
				i = next_active_region_index_in_nid(i, nid))

/**
 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
2970 2971
 * @nid: The node to free memory on. If MAX_NUMNODES, all nodes are freed.
 * @max_low_pfn: The highest PFN that will be passed to free_bootmem_node
2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
 * this function may be used instead of calling free_bootmem() manually.
 */
void __init free_bootmem_with_active_regions(int nid,
						unsigned long max_low_pfn)
{
	int i;

	for_each_active_range_index_in_nid(i, nid) {
		unsigned long size_pages = 0;
		unsigned long end_pfn = early_node_map[i].end_pfn;

		if (early_node_map[i].start_pfn >= max_low_pfn)
			continue;

		if (end_pfn > max_low_pfn)
			end_pfn = max_low_pfn;

		size_pages = end_pfn - early_node_map[i].start_pfn;
		free_bootmem_node(NODE_DATA(early_node_map[i].nid),
				PFN_PHYS(early_node_map[i].start_pfn),
				size_pages << PAGE_SHIFT);
	}
}

2999 3000 3001
void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
{
	int i;
3002
	int ret;
3003

3004 3005 3006 3007 3008 3009
	for_each_active_range_index_in_nid(i, nid) {
		ret = work_fn(early_node_map[i].start_pfn,
			      early_node_map[i].end_pfn, data);
		if (ret)
			break;
	}
3010
}
3011 3012
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3013
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3014 3015 3016
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
3017
 * function may be used instead of calling memory_present() manually.
3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028
 */
void __init sparse_memory_present_with_active_regions(int nid)
{
	int i;

	for_each_active_range_index_in_nid(i, nid)
		memory_present(early_node_map[i].nid,
				early_node_map[i].start_pfn,
				early_node_map[i].end_pfn);
}

3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044
/**
 * push_node_boundaries - Push node boundaries to at least the requested boundary
 * @nid: The nid of the node to push the boundary for
 * @start_pfn: The start pfn of the node
 * @end_pfn: The end pfn of the node
 *
 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
 * time. Specifically, on x86_64, SRAT will report ranges that can potentially
 * be hotplugged even though no physical memory exists. This function allows
 * an arch to push out the node boundaries so mem_map is allocated that can
 * be used later.
 */
#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
void __init push_node_boundaries(unsigned int nid,
		unsigned long start_pfn, unsigned long end_pfn)
{
3045 3046
	mminit_dprintk(MMINIT_TRACE, "zoneboundary",
			"Entering push_node_boundaries(%u, %lu, %lu)\n",
3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060
			nid, start_pfn, end_pfn);

	/* Initialise the boundary for this node if necessary */
	if (node_boundary_end_pfn[nid] == 0)
		node_boundary_start_pfn[nid] = -1UL;

	/* Update the boundaries */
	if (node_boundary_start_pfn[nid] > start_pfn)
		node_boundary_start_pfn[nid] = start_pfn;
	if (node_boundary_end_pfn[nid] < end_pfn)
		node_boundary_end_pfn[nid] = end_pfn;
}

/* If necessary, push the node boundary out for reserve hotadd */
3061
static void __meminit account_node_boundary(unsigned int nid,
3062 3063
		unsigned long *start_pfn, unsigned long *end_pfn)
{
3064 3065
	mminit_dprintk(MMINIT_TRACE, "zoneboundary",
			"Entering account_node_boundary(%u, %lu, %lu)\n",
3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081
			nid, *start_pfn, *end_pfn);

	/* Return if boundary information has not been provided */
	if (node_boundary_end_pfn[nid] == 0)
		return;

	/* Check the boundaries and update if necessary */
	if (node_boundary_start_pfn[nid] < *start_pfn)
		*start_pfn = node_boundary_start_pfn[nid];
	if (node_boundary_end_pfn[nid] > *end_pfn)
		*end_pfn = node_boundary_end_pfn[nid];
}
#else
void __init push_node_boundaries(unsigned int nid,
		unsigned long start_pfn, unsigned long end_pfn) {}

3082
static void __meminit account_node_boundary(unsigned int nid,
3083 3084 3085 3086
		unsigned long *start_pfn, unsigned long *end_pfn) {}
#endif


3087 3088
/**
 * get_pfn_range_for_nid - Return the start and end page frames for a node
3089 3090 3091
 * @nid: The nid to return the range for. If MAX_NUMNODES, the min and max PFN are returned.
 * @start_pfn: Passed by reference. On return, it will have the node start_pfn.
 * @end_pfn: Passed by reference. On return, it will have the node end_pfn.
3092 3093 3094 3095
 *
 * It returns the start and end page frame of a node based on information
 * provided by an arch calling add_active_range(). If called for a node
 * with no available memory, a warning is printed and the start and end
3096
 * PFNs will be 0.
3097
 */
3098
void __meminit get_pfn_range_for_nid(unsigned int nid,
3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109
			unsigned long *start_pfn, unsigned long *end_pfn)
{
	int i;
	*start_pfn = -1UL;
	*end_pfn = 0;

	for_each_active_range_index_in_nid(i, nid) {
		*start_pfn = min(*start_pfn, early_node_map[i].start_pfn);
		*end_pfn = max(*end_pfn, early_node_map[i].end_pfn);
	}

3110
	if (*start_pfn == -1UL)
3111
		*start_pfn = 0;
3112 3113 3114

	/* Push the node boundaries out if requested */
	account_node_boundary(nid, start_pfn, end_pfn);
3115 3116
}

M
Mel Gorman 已提交
3117 3118 3119 3120 3121
/*
 * This finds a zone that can be used for ZONE_MOVABLE pages. The
 * assumption is made that zones within a node are ordered in monotonic
 * increasing memory addresses so that the "highest" populated zone is used
 */
A
Adrian Bunk 已提交
3122
static void __init find_usable_zone_for_movable(void)
M
Mel Gorman 已提交
3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147
{
	int zone_index;
	for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
		if (zone_index == ZONE_MOVABLE)
			continue;

		if (arch_zone_highest_possible_pfn[zone_index] >
				arch_zone_lowest_possible_pfn[zone_index])
			break;
	}

	VM_BUG_ON(zone_index == -1);
	movable_zone = zone_index;
}

/*
 * The zone ranges provided by the architecture do not include ZONE_MOVABLE
 * because it is sized independant of architecture. Unlike the other zones,
 * the starting point for ZONE_MOVABLE is not fixed. It may be different
 * in each node depending on the size of each node and how evenly kernelcore
 * is distributed. This helper function adjusts the zone ranges
 * provided by the architecture for a given node by using the end of the
 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
 * zones within a node are in order of monotonic increases memory addresses
 */
A
Adrian Bunk 已提交
3148
static void __meminit adjust_zone_range_for_zone_movable(int nid,
M
Mel Gorman 已提交
3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173
					unsigned long zone_type,
					unsigned long node_start_pfn,
					unsigned long node_end_pfn,
					unsigned long *zone_start_pfn,
					unsigned long *zone_end_pfn)
{
	/* Only adjust if ZONE_MOVABLE is on this node */
	if (zone_movable_pfn[nid]) {
		/* Size ZONE_MOVABLE */
		if (zone_type == ZONE_MOVABLE) {
			*zone_start_pfn = zone_movable_pfn[nid];
			*zone_end_pfn = min(node_end_pfn,
				arch_zone_highest_possible_pfn[movable_zone]);

		/* Adjust for ZONE_MOVABLE starting within this range */
		} else if (*zone_start_pfn < zone_movable_pfn[nid] &&
				*zone_end_pfn > zone_movable_pfn[nid]) {
			*zone_end_pfn = zone_movable_pfn[nid];

		/* Check if this whole range is within ZONE_MOVABLE */
		} else if (*zone_start_pfn >= zone_movable_pfn[nid])
			*zone_start_pfn = *zone_end_pfn;
	}
}

3174 3175 3176 3177
/*
 * Return the number of pages a zone spans in a node, including holes
 * present_pages = zone_spanned_pages_in_node() - zone_absent_pages_in_node()
 */
P
Paul Mundt 已提交
3178
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3179 3180 3181 3182 3183 3184 3185 3186 3187 3188
					unsigned long zone_type,
					unsigned long *ignored)
{
	unsigned long node_start_pfn, node_end_pfn;
	unsigned long zone_start_pfn, zone_end_pfn;

	/* Get the start and end of the node and zone */
	get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
	zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
	zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
M
Mel Gorman 已提交
3189 3190 3191
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206

	/* Check that this node has pages within the zone's required range */
	if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
		return 0;

	/* Move the zone boundaries inside the node if necessary */
	zone_end_pfn = min(zone_end_pfn, node_end_pfn);
	zone_start_pfn = max(zone_start_pfn, node_start_pfn);

	/* Return the spanned pages */
	return zone_end_pfn - zone_start_pfn;
}

/*
 * Return the number of holes in a range on a node. If nid is MAX_NUMNODES,
3207
 * then all holes in the requested range will be accounted for.
3208
 */
A
Adrian Bunk 已提交
3209
static unsigned long __meminit __absent_pages_in_range(int nid,
3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221
				unsigned long range_start_pfn,
				unsigned long range_end_pfn)
{
	int i = 0;
	unsigned long prev_end_pfn = 0, hole_pages = 0;
	unsigned long start_pfn;

	/* Find the end_pfn of the first active range of pfns in the node */
	i = first_active_region_index_in_nid(nid);
	if (i == -1)
		return 0;

3222 3223
	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);

3224 3225
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
3226
		hole_pages = prev_end_pfn - range_start_pfn;
3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246

	/* Find all holes for the zone within the node */
	for (; i != -1; i = next_active_region_index_in_nid(i, nid)) {

		/* No need to continue if prev_end_pfn is outside the zone */
		if (prev_end_pfn >= range_end_pfn)
			break;

		/* Make sure the end of the zone is not within the hole */
		start_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
		prev_end_pfn = max(prev_end_pfn, range_start_pfn);

		/* Update the hole size cound and move on */
		if (start_pfn > range_start_pfn) {
			BUG_ON(prev_end_pfn > start_pfn);
			hole_pages += start_pfn - prev_end_pfn;
		}
		prev_end_pfn = early_node_map[i].end_pfn;
	}

3247 3248
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
3249
		hole_pages += range_end_pfn -
3250 3251
				max(range_start_pfn, prev_end_pfn);

3252 3253 3254 3255 3256 3257 3258 3259
	return hole_pages;
}

/**
 * absent_pages_in_range - Return number of page frames in holes within a range
 * @start_pfn: The start PFN to start searching for holes
 * @end_pfn: The end PFN to stop searching for holes
 *
3260
 * It returns the number of pages frames in memory holes within a range.
3261 3262 3263 3264 3265 3266 3267 3268
 */
unsigned long __init absent_pages_in_range(unsigned long start_pfn,
							unsigned long end_pfn)
{
	return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
}

/* Return the number of page frames in holes in a zone on a node */
P
Paul Mundt 已提交
3269
static unsigned long __meminit zone_absent_pages_in_node(int nid,
3270 3271 3272
					unsigned long zone_type,
					unsigned long *ignored)
{
3273 3274 3275 3276 3277 3278 3279 3280 3281
	unsigned long node_start_pfn, node_end_pfn;
	unsigned long zone_start_pfn, zone_end_pfn;

	get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
	zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type],
							node_start_pfn);
	zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type],
							node_end_pfn);

M
Mel Gorman 已提交
3282 3283 3284
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
3285
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3286
}
3287

3288
#else
P
Paul Mundt 已提交
3289
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3290 3291 3292 3293 3294 3295
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
3296
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3297 3298 3299 3300 3301 3302 3303 3304
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
3305

3306 3307
#endif

3308
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328
		unsigned long *zones_size, unsigned long *zholes_size)
{
	unsigned long realtotalpages, totalpages = 0;
	enum zone_type i;

	for (i = 0; i < MAX_NR_ZONES; i++)
		totalpages += zone_spanned_pages_in_node(pgdat->node_id, i,
								zones_size);
	pgdat->node_spanned_pages = totalpages;

	realtotalpages = totalpages;
	for (i = 0; i < MAX_NR_ZONES; i++)
		realtotalpages -=
			zone_absent_pages_in_node(pgdat->node_id, i,
								zholes_size);
	pgdat->node_present_pages = realtotalpages;
	printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
							realtotalpages);
}

3329 3330 3331
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
3332 3333
 * Start by making sure zonesize is a multiple of pageblock_order by rounding
 * up. Then use 1 NR_PAGEBLOCK_BITS worth of bits per pageblock, finally
3334 3335 3336 3337 3338 3339 3340
 * round what is now in bits to nearest long in bits, then return it in
 * bytes.
 */
static unsigned long __init usemap_size(unsigned long zonesize)
{
	unsigned long usemapsize;

3341 3342
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363
	usemapsize *= NR_PAGEBLOCK_BITS;
	usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));

	return usemapsize / 8;
}

static void __init setup_usemap(struct pglist_data *pgdat,
				struct zone *zone, unsigned long zonesize)
{
	unsigned long usemapsize = usemap_size(zonesize);
	zone->pageblock_flags = NULL;
	if (usemapsize) {
		zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize);
		memset(zone->pageblock_flags, 0, usemapsize);
	}
}
#else
static void inline setup_usemap(struct pglist_data *pgdat,
				struct zone *zone, unsigned long zonesize) {}
#endif /* CONFIG_SPARSEMEM */

3364
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3365 3366 3367 3368 3369 3370 3371 3372 3373 3374

/* Return a sensible default order for the pageblock size. */
static inline int pageblock_default_order(void)
{
	if (HPAGE_SHIFT > PAGE_SHIFT)
		return HUGETLB_PAGE_ORDER;

	return MAX_ORDER-1;
}

3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389
/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
static inline void __init set_pageblock_order(unsigned int order)
{
	/* Check that pageblock_nr_pages has not already been setup */
	if (pageblock_order)
		return;

	/*
	 * Assume the largest contiguous order of interest is a huge page.
	 * This value may be variable depending on boot parameters on IA64
	 */
	pageblock_order = order;
}
#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

3390 3391 3392 3393 3394 3395 3396 3397 3398 3399
/*
 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
 * and pageblock_default_order() are unused as pageblock_order is set
 * at compile-time. See include/linux/pageblock-flags.h for the values of
 * pageblock_order based on the kernel config
 */
static inline int pageblock_default_order(unsigned int order)
{
	return MAX_ORDER-1;
}
3400 3401 3402 3403
#define set_pageblock_order(x)	do {} while (0)

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
3404 3405 3406 3407 3408 3409
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
3410
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3411 3412
		unsigned long *zones_size, unsigned long *zholes_size)
{
3413
	enum zone_type j;
3414
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
3415
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
3416
	int ret;
L
Linus Torvalds 已提交
3417

3418
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
3419 3420 3421 3422 3423 3424
	pgdat->nr_zones = 0;
	init_waitqueue_head(&pgdat->kswapd_wait);
	pgdat->kswapd_max_order = 0;
	
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
3425
		unsigned long size, realsize, memmap_pages;
3426
		enum lru_list l;
L
Linus Torvalds 已提交
3427

3428 3429 3430
		size = zone_spanned_pages_in_node(nid, j, zones_size);
		realsize = size - zone_absent_pages_in_node(nid, j,
								zholes_size);
L
Linus Torvalds 已提交
3431

3432 3433 3434 3435 3436
		/*
		 * Adjust realsize so that it accounts for how much memory
		 * is used by this zone for memmap. This affects the watermark
		 * and per-cpu initialisations
		 */
3437 3438
		memmap_pages =
			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
3439 3440
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
3441 3442
			mminit_dprintk(MMINIT_TRACE, "memmap_init",
				"%s zone: %lu pages used for memmap\n",
3443 3444 3445 3446 3447 3448
				zone_names[j], memmap_pages);
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

3449 3450
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
3451
			realsize -= dma_reserve;
3452 3453
			mminit_dprintk(MMINIT_TRACE, "memmap_init",
					"%s zone: %lu pages reserved\n",
3454
					zone_names[0], dma_reserve);
3455 3456
		}

3457
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
3458 3459 3460 3461 3462
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
3463
#ifdef CONFIG_NUMA
3464
		zone->node = nid;
3465
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3466
						/ 100;
3467
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3468
#endif
L
Linus Torvalds 已提交
3469 3470 3471
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
3472
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
3473 3474
		zone->zone_pgdat = pgdat;

3475
		zone->prev_priority = DEF_PRIORITY;
L
Linus Torvalds 已提交
3476

3477
		zone_pcp_init(zone);
3478 3479 3480 3481
		for_each_lru(l) {
			INIT_LIST_HEAD(&zone->lru[l].list);
			zone->lru[l].nr_scan = 0;
		}
3482 3483 3484 3485
		zone->recent_rotated[0] = 0;
		zone->recent_rotated[1] = 0;
		zone->recent_scanned[0] = 0;
		zone->recent_scanned[1] = 0;
3486
		zap_zone_vm_stats(zone);
3487
		zone->flags = 0;
L
Linus Torvalds 已提交
3488 3489 3490
		if (!size)
			continue;

3491
		set_pageblock_order(pageblock_default_order());
3492
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
3493 3494
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
3495
		BUG_ON(ret);
3496
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
3497 3498 3499 3500
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
3501
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
3502 3503 3504 3505 3506
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
3507
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
3508 3509
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
3510
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
3511 3512
		struct page *map;

3513 3514 3515 3516 3517 3518 3519 3520 3521
		/*
		 * The zone's endpoints aren't required to be MAX_ORDER
		 * aligned but the node_mem_map endpoints must be in order
		 * for the buddy allocator to function correctly.
		 */
		start = pgdat->node_start_pfn & ~(MAX_ORDER_NR_PAGES - 1);
		end = pgdat->node_start_pfn + pgdat->node_spanned_pages;
		end = ALIGN(end, MAX_ORDER_NR_PAGES);
		size =  (end - start) * sizeof(struct page);
3522 3523 3524
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
3525
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
3526
	}
3527
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
3528 3529 3530
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
3531
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
3532
		mem_map = NODE_DATA(0)->node_mem_map;
3533 3534
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3535
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3536 3537
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
3538
#endif
A
Andy Whitcroft 已提交
3539
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
3540 3541
}

3542 3543
void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
		unsigned long node_start_pfn, unsigned long *zholes_size)
L
Linus Torvalds 已提交
3544
{
3545 3546
	pg_data_t *pgdat = NODE_DATA(nid);

L
Linus Torvalds 已提交
3547 3548
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
3549
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
3550 3551

	alloc_node_mem_map(pgdat);
3552 3553 3554 3555 3556
#ifdef CONFIG_FLAT_NODE_MEM_MAP
	printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
		nid, (unsigned long)pgdat,
		(unsigned long)pgdat->node_mem_map);
#endif
L
Linus Torvalds 已提交
3557 3558 3559 3560

	free_area_init_core(pgdat, zones_size, zholes_size);
}

3561
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
M
Miklos Szeredi 已提交
3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581

#if MAX_NUMNODES > 1
/*
 * Figure out the number of possible node ids.
 */
static void __init setup_nr_node_ids(void)
{
	unsigned int node;
	unsigned int highest = 0;

	for_each_node_mask(node, node_possible_map)
		highest = node;
	nr_node_ids = highest + 1;
}
#else
static inline void setup_nr_node_ids(void)
{
}
#endif

3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598
/**
 * add_active_range - Register a range of PFNs backed by physical memory
 * @nid: The node ID the range resides on
 * @start_pfn: The start PFN of the available physical memory
 * @end_pfn: The end PFN of the available physical memory
 *
 * These ranges are stored in an early_node_map[] and later used by
 * free_area_init_nodes() to calculate zone sizes and holes. If the
 * range spans a memory hole, it is up to the architecture to ensure
 * the memory is not freed by the bootmem allocator. If possible
 * the range being registered will be merged with existing ranges.
 */
void __init add_active_range(unsigned int nid, unsigned long start_pfn,
						unsigned long end_pfn)
{
	int i;

3599 3600 3601 3602 3603
	mminit_dprintk(MMINIT_TRACE, "memory_register",
			"Entering add_active_range(%d, %#lx, %#lx) "
			"%d entries of %d used\n",
			nid, start_pfn, end_pfn,
			nr_nodemap_entries, MAX_ACTIVE_REGIONS);
3604

3605 3606
	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);

3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645
	/* Merge with existing active regions if possible */
	for (i = 0; i < nr_nodemap_entries; i++) {
		if (early_node_map[i].nid != nid)
			continue;

		/* Skip if an existing region covers this new one */
		if (start_pfn >= early_node_map[i].start_pfn &&
				end_pfn <= early_node_map[i].end_pfn)
			return;

		/* Merge forward if suitable */
		if (start_pfn <= early_node_map[i].end_pfn &&
				end_pfn > early_node_map[i].end_pfn) {
			early_node_map[i].end_pfn = end_pfn;
			return;
		}

		/* Merge backward if suitable */
		if (start_pfn < early_node_map[i].end_pfn &&
				end_pfn >= early_node_map[i].start_pfn) {
			early_node_map[i].start_pfn = start_pfn;
			return;
		}
	}

	/* Check that early_node_map is large enough */
	if (i >= MAX_ACTIVE_REGIONS) {
		printk(KERN_CRIT "More than %d memory regions, truncating\n",
							MAX_ACTIVE_REGIONS);
		return;
	}

	early_node_map[i].nid = nid;
	early_node_map[i].start_pfn = start_pfn;
	early_node_map[i].end_pfn = end_pfn;
	nr_nodemap_entries = i + 1;
}

/**
3646
 * remove_active_range - Shrink an existing registered range of PFNs
3647
 * @nid: The node id the range is on that should be shrunk
3648 3649
 * @start_pfn: The new PFN of the range
 * @end_pfn: The new PFN of the range
3650 3651
 *
 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3652 3653 3654
 * The map is kept near the end physical page range that has already been
 * registered. This function allows an arch to shrink an existing registered
 * range.
3655
 */
3656 3657
void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
				unsigned long end_pfn)
3658
{
3659 3660
	int i, j;
	int removed = 0;
3661

3662 3663 3664
	printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
			  nid, start_pfn, end_pfn);

3665
	/* Find the old active region end and shrink */
3666
	for_each_active_range_index_in_nid(i, nid) {
3667 3668
		if (early_node_map[i].start_pfn >= start_pfn &&
		    early_node_map[i].end_pfn <= end_pfn) {
3669
			/* clear it */
3670
			early_node_map[i].start_pfn = 0;
3671 3672 3673 3674
			early_node_map[i].end_pfn = 0;
			removed = 1;
			continue;
		}
3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686
		if (early_node_map[i].start_pfn < start_pfn &&
		    early_node_map[i].end_pfn > start_pfn) {
			unsigned long temp_end_pfn = early_node_map[i].end_pfn;
			early_node_map[i].end_pfn = start_pfn;
			if (temp_end_pfn > end_pfn)
				add_active_range(nid, end_pfn, temp_end_pfn);
			continue;
		}
		if (early_node_map[i].start_pfn >= start_pfn &&
		    early_node_map[i].end_pfn > end_pfn &&
		    early_node_map[i].start_pfn < end_pfn) {
			early_node_map[i].start_pfn = end_pfn;
3687
			continue;
3688
		}
3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707
	}

	if (!removed)
		return;

	/* remove the blank ones */
	for (i = nr_nodemap_entries - 1; i > 0; i--) {
		if (early_node_map[i].nid != nid)
			continue;
		if (early_node_map[i].end_pfn)
			continue;
		/* we found it, get rid of it */
		for (j = i; j < nr_nodemap_entries - 1; j++)
			memcpy(&early_node_map[j], &early_node_map[j+1],
				sizeof(early_node_map[j]));
		j = nr_nodemap_entries - 1;
		memset(&early_node_map[j], 0, sizeof(early_node_map[j]));
		nr_nodemap_entries--;
	}
3708 3709 3710 3711
}

/**
 * remove_all_active_ranges - Remove all currently registered regions
3712
 *
3713 3714 3715 3716
 * During discovery, it may be found that a table like SRAT is invalid
 * and an alternative discovery method must be used. This function removes
 * all currently registered regions.
 */
3717
void __init remove_all_active_ranges(void)
3718 3719 3720
{
	memset(early_node_map, 0, sizeof(early_node_map));
	nr_nodemap_entries = 0;
3721 3722 3723 3724
#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
	memset(node_boundary_start_pfn, 0, sizeof(node_boundary_start_pfn));
	memset(node_boundary_end_pfn, 0, sizeof(node_boundary_end_pfn));
#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749
}

/* Compare two active node_active_regions */
static int __init cmp_node_active_region(const void *a, const void *b)
{
	struct node_active_region *arange = (struct node_active_region *)a;
	struct node_active_region *brange = (struct node_active_region *)b;

	/* Done this way to avoid overflows */
	if (arange->start_pfn > brange->start_pfn)
		return 1;
	if (arange->start_pfn < brange->start_pfn)
		return -1;

	return 0;
}

/* sort the node_map by start_pfn */
static void __init sort_node_map(void)
{
	sort(early_node_map, (size_t)nr_nodemap_entries,
			sizeof(struct node_active_region),
			cmp_node_active_region, NULL);
}

3750
/* Find the lowest pfn for a node */
A
Adrian Bunk 已提交
3751
static unsigned long __init find_min_pfn_for_node(int nid)
3752 3753
{
	int i;
3754
	unsigned long min_pfn = ULONG_MAX;
3755

3756 3757
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
3758
		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
3759

3760 3761
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
3762
			"Could not find start_pfn for node %d\n", nid);
3763 3764 3765 3766
		return 0;
	}

	return min_pfn;
3767 3768 3769 3770 3771 3772
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
3773
 * add_active_range().
3774 3775 3776 3777 3778 3779
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

3780 3781 3782 3783 3784
/*
 * early_calculate_totalpages()
 * Sum pages in active regions for movable zone.
 * Populate N_HIGH_MEMORY for calculating usable_nodes.
 */
A
Adrian Bunk 已提交
3785
static unsigned long __init early_calculate_totalpages(void)
3786 3787 3788 3789
{
	int i;
	unsigned long totalpages = 0;

3790 3791
	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long pages = early_node_map[i].end_pfn -
3792
						early_node_map[i].start_pfn;
3793 3794 3795 3796 3797
		totalpages += pages;
		if (pages)
			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
	}
  	return totalpages;
3798 3799
}

M
Mel Gorman 已提交
3800 3801 3802 3803 3804 3805
/*
 * Find the PFN the Movable zone begins in each node. Kernel memory
 * is spread evenly between nodes as long as the nodes have enough
 * memory. When they don't, some nodes will have more kernelcore than
 * others
 */
A
Adrian Bunk 已提交
3806
static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
M
Mel Gorman 已提交
3807 3808 3809 3810
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
3811 3812
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
3813

3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835
	/*
	 * If movablecore was specified, calculate what size of
	 * kernelcore that corresponds so that memory usable for
	 * any allocation type is evenly spread. If both kernelcore
	 * and movablecore are specified, then the value of kernelcore
	 * will be used for required_kernelcore if it's greater than
	 * what movablecore would have allowed.
	 */
	if (required_movablecore) {
		unsigned long corepages;

		/*
		 * Round-up so that ZONE_MOVABLE is at least as large as what
		 * was requested by the user
		 */
		required_movablecore =
			roundup(required_movablecore, MAX_ORDER_NR_PAGES);
		corepages = totalpages - required_movablecore;

		required_kernelcore = max(required_kernelcore, corepages);
	}

M
Mel Gorman 已提交
3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846
	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
	if (!required_kernelcore)
		return;

	/* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
	find_usable_zone_for_movable();
	usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];

restart:
	/* Spread kernelcore memory as evenly as possible throughout nodes */
	kernelcore_node = required_kernelcore / usable_nodes;
3847
	for_each_node_state(nid, N_HIGH_MEMORY) {
M
Mel Gorman 已提交
3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938
		/*
		 * Recalculate kernelcore_node if the division per node
		 * now exceeds what is necessary to satisfy the requested
		 * amount of memory for the kernel
		 */
		if (required_kernelcore < kernelcore_node)
			kernelcore_node = required_kernelcore / usable_nodes;

		/*
		 * As the map is walked, we track how much memory is usable
		 * by the kernel using kernelcore_remaining. When it is
		 * 0, the rest of the node is usable by ZONE_MOVABLE
		 */
		kernelcore_remaining = kernelcore_node;

		/* Go through each range of PFNs within this node */
		for_each_active_range_index_in_nid(i, nid) {
			unsigned long start_pfn, end_pfn;
			unsigned long size_pages;

			start_pfn = max(early_node_map[i].start_pfn,
						zone_movable_pfn[nid]);
			end_pfn = early_node_map[i].end_pfn;
			if (start_pfn >= end_pfn)
				continue;

			/* Account for what is only usable for kernelcore */
			if (start_pfn < usable_startpfn) {
				unsigned long kernel_pages;
				kernel_pages = min(end_pfn, usable_startpfn)
								- start_pfn;

				kernelcore_remaining -= min(kernel_pages,
							kernelcore_remaining);
				required_kernelcore -= min(kernel_pages,
							required_kernelcore);

				/* Continue if range is now fully accounted */
				if (end_pfn <= usable_startpfn) {

					/*
					 * Push zone_movable_pfn to the end so
					 * that if we have to rebalance
					 * kernelcore across nodes, we will
					 * not double account here
					 */
					zone_movable_pfn[nid] = end_pfn;
					continue;
				}
				start_pfn = usable_startpfn;
			}

			/*
			 * The usable PFN range for ZONE_MOVABLE is from
			 * start_pfn->end_pfn. Calculate size_pages as the
			 * number of pages used as kernelcore
			 */
			size_pages = end_pfn - start_pfn;
			if (size_pages > kernelcore_remaining)
				size_pages = kernelcore_remaining;
			zone_movable_pfn[nid] = start_pfn + size_pages;

			/*
			 * Some kernelcore has been met, update counts and
			 * break if the kernelcore for this node has been
			 * satisified
			 */
			required_kernelcore -= min(required_kernelcore,
								size_pages);
			kernelcore_remaining -= size_pages;
			if (!kernelcore_remaining)
				break;
		}
	}

	/*
	 * If there is still required_kernelcore, we do another pass with one
	 * less node in the count. This will push zone_movable_pfn[nid] further
	 * along on the nodes that still have memory until kernelcore is
	 * satisified
	 */
	usable_nodes--;
	if (usable_nodes && required_kernelcore > usable_nodes)
		goto restart;

	/* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
	for (nid = 0; nid < MAX_NUMNODES; nid++)
		zone_movable_pfn[nid] =
			roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
}

3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952
/* Any regular memory on that node ? */
static void check_for_regular_memory(pg_data_t *pgdat)
{
#ifdef CONFIG_HIGHMEM
	enum zone_type zone_type;

	for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) {
		struct zone *zone = &pgdat->node_zones[zone_type];
		if (zone->present_pages)
			node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
	}
#endif
}

3953 3954
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
3955
 * @max_zone_pfn: an array of max PFNs for each zone
3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968
 *
 * This will call free_area_init_node() for each active node in the system.
 * Using the page ranges provided by add_active_range(), the size of each
 * zone in each node and their holes is calculated. If the maximum PFN
 * between two adjacent zones match, it is assumed that the zone is empty.
 * For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
 * that arch_max_dma32_pfn has no pages. It is also assumed that a zone
 * starts where the previous one ended. For example, ZONE_DMA32 starts
 * at arch_max_dma_pfn.
 */
void __init free_area_init_nodes(unsigned long *max_zone_pfn)
{
	unsigned long nid;
3969
	int i;
3970

3971 3972 3973
	/* Sort early_node_map as initialisation assumes it is sorted */
	sort_node_map();

3974 3975 3976 3977 3978 3979 3980 3981
	/* Record where the zone boundaries are */
	memset(arch_zone_lowest_possible_pfn, 0,
				sizeof(arch_zone_lowest_possible_pfn));
	memset(arch_zone_highest_possible_pfn, 0,
				sizeof(arch_zone_highest_possible_pfn));
	arch_zone_lowest_possible_pfn[0] = find_min_pfn_with_active_regions();
	arch_zone_highest_possible_pfn[0] = max_zone_pfn[0];
	for (i = 1; i < MAX_NR_ZONES; i++) {
M
Mel Gorman 已提交
3982 3983
		if (i == ZONE_MOVABLE)
			continue;
3984 3985 3986 3987 3988
		arch_zone_lowest_possible_pfn[i] =
			arch_zone_highest_possible_pfn[i-1];
		arch_zone_highest_possible_pfn[i] =
			max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
	}
M
Mel Gorman 已提交
3989 3990 3991 3992 3993 3994
	arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
	arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;

	/* Find the PFNs that ZONE_MOVABLE begins at in each node */
	memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
	find_zone_movable_pfns_for_nodes(zone_movable_pfn);
3995 3996 3997

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
M
Mel Gorman 已提交
3998 3999 4000
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
4001
		printk("  %-8s %0#10lx -> %0#10lx\n",
4002 4003 4004
				zone_names[i],
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);
M
Mel Gorman 已提交
4005 4006 4007 4008 4009 4010 4011 4012
	}

	/* Print out the PFNs ZONE_MOVABLE begins at in each node */
	printk("Movable zone start PFN for each node\n");
	for (i = 0; i < MAX_NUMNODES; i++) {
		if (zone_movable_pfn[i])
			printk("  Node %d: %lu\n", i, zone_movable_pfn[i]);
	}
4013 4014 4015 4016

	/* Print out the early_node_map[] */
	printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries);
	for (i = 0; i < nr_nodemap_entries; i++)
4017
		printk("  %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4018 4019 4020 4021
						early_node_map[i].start_pfn,
						early_node_map[i].end_pfn);

	/* Initialise every node */
4022
	mminit_verify_pageflags_layout();
4023
	setup_nr_node_ids();
4024 4025
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
4026
		free_area_init_node(nid, NULL,
4027
				find_min_pfn_for_node(nid), NULL);
4028 4029 4030 4031 4032

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
4033 4034
	}
}
M
Mel Gorman 已提交
4035

4036
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
4037 4038 4039 4040 4041 4042
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
4043
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
4044

4045
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
4046 4047 4048 4049
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
4050

4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068
/*
 * kernelcore=size sets the amount of memory for use for allocations that
 * cannot be reclaimed or migrated.
 */
static int __init cmdline_parse_kernelcore(char *p)
{
	return cmdline_parse_core(p, &required_kernelcore);
}

/*
 * movablecore=size sets the amount of memory for use for allocations that
 * can be reclaimed or migrated.
 */
static int __init cmdline_parse_movablecore(char *p)
{
	return cmdline_parse_core(p, &required_movablecore);
}

M
Mel Gorman 已提交
4069
early_param("kernelcore", cmdline_parse_kernelcore);
4070
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
4071

4072 4073
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

4074
/**
4075 4076
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
4077 4078 4079 4080
 *
 * The per-cpu batchsize and zone watermarks are determined by present_pages.
 * In the DMA zone, a significant percentage may be consumed by kernel image
 * and other unfreeable allocations which can skew the watermarks badly. This
4081 4082 4083
 * function may optionally be used to account for unfreeable pages in the
 * first zone (e.g., ZONE_DMA). The effect will be lower watermarks and
 * smaller per-cpu batchsize.
4084 4085 4086 4087 4088 4089
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

4090
#ifndef CONFIG_NEED_MULTIPLE_NODES
4091
struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] };
L
Linus Torvalds 已提交
4092
EXPORT_SYMBOL(contig_page_data);
4093
#endif
L
Linus Torvalds 已提交
4094 4095 4096

void __init free_area_init(unsigned long *zones_size)
{
4097
	free_area_init_node(0, zones_size,
L
Linus Torvalds 已提交
4098 4099 4100 4101 4102 4103 4104 4105
			__pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
}

static int page_alloc_cpu_notify(struct notifier_block *self,
				 unsigned long action, void *hcpu)
{
	int cpu = (unsigned long)hcpu;

4106
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4107 4108 4109 4110 4111 4112 4113 4114
		drain_pages(cpu);

		/*
		 * Spill the event counters of the dead processor
		 * into the current processors event counters.
		 * This artificially elevates the count of the current
		 * processor.
		 */
4115
		vm_events_fold_cpu(cpu);
4116 4117 4118 4119 4120 4121 4122 4123

		/*
		 * Zero the differential counters of the dead processor
		 * so that the vm statistics are consistent.
		 *
		 * This is only okay since the processor is dead and cannot
		 * race with what we are doing.
		 */
4124
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
4125 4126 4127 4128 4129 4130 4131 4132 4133
	}
	return NOTIFY_OK;
}

void __init page_alloc_init(void)
{
	hotcpu_notifier(page_alloc_cpu_notify, 0);
}

4134 4135 4136 4137 4138 4139 4140 4141
/*
 * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
 *	or min_free_kbytes changes.
 */
static void calculate_totalreserve_pages(void)
{
	struct pglist_data *pgdat;
	unsigned long reserve_pages = 0;
4142
	enum zone_type i, j;
4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165

	for_each_online_pgdat(pgdat) {
		for (i = 0; i < MAX_NR_ZONES; i++) {
			struct zone *zone = pgdat->node_zones + i;
			unsigned long max = 0;

			/* Find valid and maximum lowmem_reserve in the zone */
			for (j = i; j < MAX_NR_ZONES; j++) {
				if (zone->lowmem_reserve[j] > max)
					max = zone->lowmem_reserve[j];
			}

			/* we treat pages_high as reserved pages. */
			max += zone->pages_high;

			if (max > zone->present_pages)
				max = zone->present_pages;
			reserve_pages += max;
		}
	}
	totalreserve_pages = reserve_pages;
}

L
Linus Torvalds 已提交
4166 4167 4168 4169 4170 4171 4172 4173 4174
/*
 * setup_per_zone_lowmem_reserve - called whenever
 *	sysctl_lower_zone_reserve_ratio changes.  Ensures that each zone
 *	has a correct pages reserved value, so an adequate number of
 *	pages are left in the zone after a successful __alloc_pages().
 */
static void setup_per_zone_lowmem_reserve(void)
{
	struct pglist_data *pgdat;
4175
	enum zone_type j, idx;
L
Linus Torvalds 已提交
4176

4177
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
4178 4179 4180 4181 4182 4183
		for (j = 0; j < MAX_NR_ZONES; j++) {
			struct zone *zone = pgdat->node_zones + j;
			unsigned long present_pages = zone->present_pages;

			zone->lowmem_reserve[j] = 0;

4184 4185
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
4186 4187
				struct zone *lower_zone;

4188 4189
				idx--;

L
Linus Torvalds 已提交
4190 4191 4192 4193 4194 4195 4196 4197 4198 4199
				if (sysctl_lowmem_reserve_ratio[idx] < 1)
					sysctl_lowmem_reserve_ratio[idx] = 1;

				lower_zone = pgdat->node_zones + idx;
				lower_zone->lowmem_reserve[j] = present_pages /
					sysctl_lowmem_reserve_ratio[idx];
				present_pages += lower_zone->present_pages;
			}
		}
	}
4200 4201 4202

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4203 4204
}

4205 4206 4207 4208 4209
/**
 * setup_per_zone_pages_min - called when min_free_kbytes changes.
 *
 * Ensures that the pages_{min,low,high} values for each zone are set correctly
 * with respect to min_free_kbytes.
L
Linus Torvalds 已提交
4210
 */
4211
void setup_per_zone_pages_min(void)
L
Linus Torvalds 已提交
4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224
{
	unsigned long pages_min = min_free_kbytes >> (PAGE_SHIFT - 10);
	unsigned long lowmem_pages = 0;
	struct zone *zone;
	unsigned long flags;

	/* Calculate total number of !ZONE_HIGHMEM pages */
	for_each_zone(zone) {
		if (!is_highmem(zone))
			lowmem_pages += zone->present_pages;
	}

	for_each_zone(zone) {
4225 4226
		u64 tmp;

L
Linus Torvalds 已提交
4227
		spin_lock_irqsave(&zone->lru_lock, flags);
4228 4229
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
4230 4231
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
4232 4233 4234 4235 4236 4237 4238
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
			 * The (pages_high-pages_low) and (pages_low-pages_min)
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
Linus Torvalds 已提交
4239 4240 4241 4242 4243 4244 4245 4246 4247 4248
			 */
			int min_pages;

			min_pages = zone->present_pages / 1024;
			if (min_pages < SWAP_CLUSTER_MAX)
				min_pages = SWAP_CLUSTER_MAX;
			if (min_pages > 128)
				min_pages = 128;
			zone->pages_min = min_pages;
		} else {
N
Nick Piggin 已提交
4249 4250
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
4251 4252
			 * proportionate to the zone's size.
			 */
N
Nick Piggin 已提交
4253
			zone->pages_min = tmp;
L
Linus Torvalds 已提交
4254 4255
		}

4256 4257
		zone->pages_low   = zone->pages_min + (tmp >> 2);
		zone->pages_high  = zone->pages_min + (tmp >> 1);
4258
		setup_zone_migrate_reserve(zone);
L
Linus Torvalds 已提交
4259 4260
		spin_unlock_irqrestore(&zone->lru_lock, flags);
	}
4261 4262 4263

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302 4303 4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315
}

/*
 * Initialise min_free_kbytes.
 *
 * For small machines we want it small (128k min).  For large machines
 * we want it large (64MB max).  But it is not linear, because network
 * bandwidth does not increase linearly with machine size.  We use
 *
 * 	min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
 *	min_free_kbytes = sqrt(lowmem_kbytes * 16)
 *
 * which yields
 *
 * 16MB:	512k
 * 32MB:	724k
 * 64MB:	1024k
 * 128MB:	1448k
 * 256MB:	2048k
 * 512MB:	2896k
 * 1024MB:	4096k
 * 2048MB:	5792k
 * 4096MB:	8192k
 * 8192MB:	11584k
 * 16384MB:	16384k
 */
static int __init init_per_zone_pages_min(void)
{
	unsigned long lowmem_kbytes;

	lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);

	min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
	if (min_free_kbytes < 128)
		min_free_kbytes = 128;
	if (min_free_kbytes > 65536)
		min_free_kbytes = 65536;
	setup_per_zone_pages_min();
	setup_per_zone_lowmem_reserve();
	return 0;
}
module_init(init_per_zone_pages_min)

/*
 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 
 *	that we can call two helper functions whenever min_free_kbytes
 *	changes.
 */
int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	proc_dointvec(table, write, file, buffer, length, ppos);
4316 4317
	if (write)
		setup_per_zone_pages_min();
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	return 0;
}

4321 4322 4323 4324 4325 4326 4327 4328 4329 4330 4331 4332
#ifdef CONFIG_NUMA
int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	struct zone *zone;
	int rc;

	rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
	if (rc)
		return rc;

	for_each_zone(zone)
4333
		zone->min_unmapped_pages = (zone->present_pages *
4334 4335 4336
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352

int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	struct zone *zone;
	int rc;

	rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
	if (rc)
		return rc;

	for_each_zone(zone)
		zone->min_slab_pages = (zone->present_pages *
				sysctl_min_slab_ratio) / 100;
	return 0;
}
4353 4354
#endif

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/*
 * lowmem_reserve_ratio_sysctl_handler - just a wrapper around
 *	proc_dointvec() so that we can call setup_per_zone_lowmem_reserve()
 *	whenever sysctl_lowmem_reserve_ratio changes.
 *
 * The reserve ratio obviously has absolutely no relation with the
 * pages_min watermarks. The lowmem reserve ratio can only make sense
 * if in function of the boot time zone sizes.
 */
int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	proc_dointvec_minmax(table, write, file, buffer, length, ppos);
	setup_per_zone_lowmem_reserve();
	return 0;
}

4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395 4396 4397
/*
 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
 * cpu.  It is the fraction of total pages in each zone that a hot per cpu pagelist
 * can have before it gets flushed back to buddy allocator.
 */

int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	struct zone *zone;
	unsigned int cpu;
	int ret;

	ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
	if (!write || (ret == -EINVAL))
		return ret;
	for_each_zone(zone) {
		for_each_online_cpu(cpu) {
			unsigned long  high;
			high = zone->present_pages / percpu_pagelist_fraction;
			setup_pagelist_highmark(zone_pcp(zone, cpu), high);
		}
	}
	return 0;
}

4398
int hashdist = HASHDIST_DEFAULT;
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#ifdef CONFIG_NUMA
static int __init set_hashdist(char *str)
{
	if (!str)
		return 0;
	hashdist = simple_strtoul(str, &str, 0);
	return 1;
}
__setup("hashdist=", set_hashdist);
#endif

/*
 * allocate a large system hash table from bootmem
 * - it is assumed that the hash table must contain an exact power-of-2
 *   quantity of entries
 * - limit is the number of hash buckets, not the total allocation size
 */
void *__init alloc_large_system_hash(const char *tablename,
				     unsigned long bucketsize,
				     unsigned long numentries,
				     int scale,
				     int flags,
				     unsigned int *_hash_shift,
				     unsigned int *_hash_mask,
				     unsigned long limit)
{
	unsigned long long max = limit;
	unsigned long log2qty, size;
	void *table = NULL;

	/* allow the kernel cmdline to have a say */
	if (!numentries) {
		/* round applicable memory size up to nearest megabyte */
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4433
		numentries = nr_kernel_pages;
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4434 4435 4436 4437 4438 4439 4440 4441 4442
		numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
		numentries >>= 20 - PAGE_SHIFT;
		numentries <<= 20 - PAGE_SHIFT;

		/* limit to 1 bucket per 2^scale bytes of low memory */
		if (scale > PAGE_SHIFT)
			numentries >>= (scale - PAGE_SHIFT);
		else
			numentries <<= (PAGE_SHIFT - scale);
4443 4444 4445 4446

		/* Make sure we've got at least a 0-order allocation.. */
		if (unlikely((numentries * bucketsize) < PAGE_SIZE))
			numentries = PAGE_SIZE / bucketsize;
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Linus Torvalds 已提交
4447
	}
4448
	numentries = roundup_pow_of_two(numentries);
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4449 4450 4451 4452 4453 4454 4455 4456 4457 4458

	/* limit allocation size to 1/16 total memory by default */
	if (max == 0) {
		max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
		do_div(max, bucketsize);
	}

	if (numentries > max)
		numentries = max;

4459
	log2qty = ilog2(numentries);
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	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
4464
			table = alloc_bootmem_nopanic(size);
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4465 4466 4467
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
4468
			unsigned long order = get_order(size);
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4469
			table = (void*) __get_free_pages(GFP_ATOMIC, order);
4470 4471 4472 4473 4474 4475 4476 4477 4478 4479 4480 4481 4482 4483 4484
			/*
			 * If bucketsize is not a power-of-two, we may free
			 * some pages at the end of hash table.
			 */
			if (table) {
				unsigned long alloc_end = (unsigned long)table +
						(PAGE_SIZE << order);
				unsigned long used = (unsigned long)table +
						PAGE_ALIGN(size);
				split_page(virt_to_page(table), order);
				while (used < alloc_end) {
					free_page(used);
					used += PAGE_SIZE;
				}
			}
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4485 4486 4487 4488 4489 4490
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

	if (!table)
		panic("Failed to allocate %s hash table\n", tablename);

4491
	printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
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	       tablename,
	       (1U << log2qty),
4494
	       ilog2(size) - PAGE_SHIFT,
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	       size);

	if (_hash_shift)
		*_hash_shift = log2qty;
	if (_hash_mask)
		*_hash_mask = (1 << log2qty) - 1;

	return table;
}
4504 4505 4506 4507

#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
struct page *pfn_to_page(unsigned long pfn)
{
4508
	return __pfn_to_page(pfn);
4509 4510 4511
}
unsigned long page_to_pfn(struct page *page)
{
4512
	return __page_to_pfn(page);
4513 4514 4515 4516
}
EXPORT_SYMBOL(pfn_to_page);
EXPORT_SYMBOL(page_to_pfn);
#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
4517

4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529 4530 4531 4532
/* Return a pointer to the bitmap storing bits affecting a block of pages */
static inline unsigned long *get_pageblock_bitmap(struct zone *zone,
							unsigned long pfn)
{
#ifdef CONFIG_SPARSEMEM
	return __pfn_to_section(pfn)->pageblock_flags;
#else
	return zone->pageblock_flags;
#endif /* CONFIG_SPARSEMEM */
}

static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
{
#ifdef CONFIG_SPARSEMEM
	pfn &= (PAGES_PER_SECTION-1);
4533
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4534 4535
#else
	pfn = pfn - zone->zone_start_pfn;
4536
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4537 4538 4539 4540
#endif /* CONFIG_SPARSEMEM */
}

/**
4541
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4542 4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 4557 4558 4559 4560 4561 4562 4563
 * @page: The page within the block of interest
 * @start_bitidx: The first bit of interest to retrieve
 * @end_bitidx: The last bit of interest
 * returns pageblock_bits flags
 */
unsigned long get_pageblock_flags_group(struct page *page,
					int start_bitidx, int end_bitidx)
{
	struct zone *zone;
	unsigned long *bitmap;
	unsigned long pfn, bitidx;
	unsigned long flags = 0;
	unsigned long value = 1;

	zone = page_zone(page);
	pfn = page_to_pfn(page);
	bitmap = get_pageblock_bitmap(zone, pfn);
	bitidx = pfn_to_bitidx(zone, pfn);

	for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
		if (test_bit(bitidx + start_bitidx, bitmap))
			flags |= value;
4564

4565 4566 4567 4568
	return flags;
}

/**
4569
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4570 4571 4572 4573 4574 4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586
 * @page: The page within the block of interest
 * @start_bitidx: The first bit of interest
 * @end_bitidx: The last bit of interest
 * @flags: The flags to set
 */
void set_pageblock_flags_group(struct page *page, unsigned long flags,
					int start_bitidx, int end_bitidx)
{
	struct zone *zone;
	unsigned long *bitmap;
	unsigned long pfn, bitidx;
	unsigned long value = 1;

	zone = page_zone(page);
	pfn = page_to_pfn(page);
	bitmap = get_pageblock_bitmap(zone, pfn);
	bitidx = pfn_to_bitidx(zone, pfn);
4587 4588
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
4589 4590 4591 4592 4593 4594 4595

	for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
		if (flags & value)
			__set_bit(bitidx + start_bitidx, bitmap);
		else
			__clear_bit(bitidx + start_bitidx, bitmap);
}
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KAMEZAWA Hiroyuki 已提交
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/*
 * This is designed as sub function...plz see page_isolation.c also.
 * set/clear page block's type to be ISOLATE.
 * page allocater never alloc memory from ISOLATE block.
 */

int set_migratetype_isolate(struct page *page)
{
	struct zone *zone;
	unsigned long flags;
	int ret = -EBUSY;

	zone = page_zone(page);
	spin_lock_irqsave(&zone->lock, flags);
	/*
	 * In future, more migrate types will be able to be isolation target.
	 */
	if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE)
		goto out;
	set_pageblock_migratetype(page, MIGRATE_ISOLATE);
	move_freepages_block(zone, page, MIGRATE_ISOLATE);
	ret = 0;
out:
	spin_unlock_irqrestore(&zone->lock, flags);
	if (!ret)
4622
		drain_all_pages();
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KAMEZAWA Hiroyuki 已提交
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	return ret;
}

void unset_migratetype_isolate(struct page *page)
{
	struct zone *zone;
	unsigned long flags;
	zone = page_zone(page);
	spin_lock_irqsave(&zone->lock, flags);
	if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
		goto out;
	set_pageblock_migratetype(page, MIGRATE_MOVABLE);
	move_freepages_block(zone, page, MIGRATE_MOVABLE);
out:
	spin_unlock_irqrestore(&zone->lock, flags);
}
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KAMEZAWA Hiroyuki 已提交
4639 4640 4641 4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655 4656 4657 4658 4659 4660 4661 4662 4663 4664 4665 4666 4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685

#ifdef CONFIG_MEMORY_HOTREMOVE
/*
 * All pages in the range must be isolated before calling this.
 */
void
__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
{
	struct page *page;
	struct zone *zone;
	int order, i;
	unsigned long pfn;
	unsigned long flags;
	/* find the first valid pfn */
	for (pfn = start_pfn; pfn < end_pfn; pfn++)
		if (pfn_valid(pfn))
			break;
	if (pfn == end_pfn)
		return;
	zone = page_zone(pfn_to_page(pfn));
	spin_lock_irqsave(&zone->lock, flags);
	pfn = start_pfn;
	while (pfn < end_pfn) {
		if (!pfn_valid(pfn)) {
			pfn++;
			continue;
		}
		page = pfn_to_page(pfn);
		BUG_ON(page_count(page));
		BUG_ON(!PageBuddy(page));
		order = page_order(page);
#ifdef CONFIG_DEBUG_VM
		printk(KERN_INFO "remove from free list %lx %d %lx\n",
		       pfn, 1 << order, end_pfn);
#endif
		list_del(&page->lru);
		rmv_page_order(page);
		zone->free_area[order].nr_free--;
		__mod_zone_page_state(zone, NR_FREE_PAGES,
				      - (1UL << order));
		for (i = 0; i < (1 << order); i++)
			SetPageReserved((page+i));
		pfn += (1 << order);
	}
	spin_unlock_irqrestore(&zone->lock, flags);
}
#endif