page_alloc.c 130.1 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/page_cgroup.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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unsigned long highest_memmap_pfn __read_mostly;
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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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	static unsigned long resume;
	static unsigned long nr_shown;
	static unsigned long nr_unshown;

	/*
	 * Allow a burst of 60 reports, then keep quiet for that minute;
	 * or allow a steady drip of one report per second.
	 */
	if (nr_shown == 60) {
		if (time_before(jiffies, resume)) {
			nr_unshown++;
			goto out;
		}
		if (nr_unshown) {
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			printk(KERN_ALERT
			      "BUG: Bad page state: %lu messages suppressed\n",
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				nr_unshown);
			nr_unshown = 0;
		}
		nr_shown = 0;
	}
	if (nr_shown++ == 0)
		resume = jiffies + 60 * HZ;

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	printk(KERN_ALERT "BUG: Bad page state in process %s  pfn:%05lx\n",
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		current->comm, page_to_pfn(page));
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	printk(KERN_ALERT
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		"page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n",
		page, (void *)page->flags, page_count(page),
		page_mapcount(page), page->mapping, page->index);

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	dump_stack();
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out:
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	/* Leave bad fields for debug, except PageBuddy could make trouble */
	__ClearPageBuddy(page);
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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;

	set_compound_page_dtor(page, free_compound_page);
	set_compound_order(page, order);
	__SetPageHead(page);
	for (i = 1; i < nr_pages; i++) {
		struct page *p = page + i;

		__SetPageTail(p);
		p->first_page = page;
	}
}

#ifdef CONFIG_HUGETLBFS
void prep_compound_gigantic_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 = mem_map_next(p, page, i)) {
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		__SetPageTail(p);
		p->first_page = page;
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	}
}
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#endif
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static int destroy_compound_page(struct page *page, unsigned long order)
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{
	int i;
	int nr_pages = 1 << order;
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	int bad = 0;
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	if (unlikely(compound_order(page) != order) ||
	    unlikely(!PageHead(page))) {
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		bad_page(page);
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		bad++;
	}
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	__ClearPageHead(page);
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	for (i = 1; i < nr_pages; i++) {
		struct page *p = page + i;
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		if (unlikely(!PageTail(p) | (p->first_page != page))) {
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			bad_page(page);
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			bad++;
		}
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		__ClearPageTail(p);
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	}
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	return bad;
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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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		if (unlikely(destroy_compound_page(page, order)))
			return;
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	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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	free_page_mlock(page);
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	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
		(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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		return 1;
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	}
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	if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
		page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
	return 0;
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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)
L
Linus Torvalds 已提交
538
{
539
	spin_lock(&zone->lock);
540
	zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
541
	zone->pages_scanned = 0;
542
	__free_one_page(page, zone, order);
543
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
544 545 546 547 548
}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
L
Linus Torvalds 已提交
549
	int i;
550
	int bad = 0;
L
Linus Torvalds 已提交
551 552

	for (i = 0 ; i < (1 << order) ; ++i)
553 554
		bad += free_pages_check(page + i);
	if (bad)
555 556
		return;

557
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
558
		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
559 560 561
		debug_check_no_obj_freed(page_address(page),
					   PAGE_SIZE << order);
	}
N
Nick Piggin 已提交
562
	arch_free_page(page, order);
N
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563
	kernel_map_pages(page, 1 << order, 0);
N
Nick Piggin 已提交
564

N
Nick Piggin 已提交
565
	local_irq_save(flags);
566
	__count_vm_events(PGFREE, 1 << order);
N
Nick Piggin 已提交
567
	free_one_page(page_zone(page), page, order);
N
Nick Piggin 已提交
568
	local_irq_restore(flags);
L
Linus Torvalds 已提交
569 570
}

571 572 573
/*
 * permit the bootmem allocator to evade page validation on high-order frees
 */
574
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
575 576 577 578
{
	if (order == 0) {
		__ClearPageReserved(page);
		set_page_count(page, 0);
579
		set_page_refcounted(page);
N
Nick Piggin 已提交
580
		__free_page(page);
581 582 583
	} else {
		int loop;

N
Nick Piggin 已提交
584
		prefetchw(page);
585 586 587
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

N
Nick Piggin 已提交
588 589
			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
590 591 592 593
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

594
		set_page_refcounted(page);
N
Nick Piggin 已提交
595
		__free_pages(page, order);
596 597 598
	}
}

L
Linus Torvalds 已提交
599 600 601 602 603 604 605 606 607 608 609 610 611 612 613

/*
 * 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
 */
N
Nick Piggin 已提交
614
static inline void expand(struct zone *zone, struct page *page,
615 616
	int low, int high, struct free_area *area,
	int migratetype)
L
Linus Torvalds 已提交
617 618 619 620 621 622 623
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
624
		VM_BUG_ON(bad_range(zone, &page[size]));
625
		list_add(&page[size].lru, &area->free_list[migratetype]);
L
Linus Torvalds 已提交
626 627 628 629 630 631 632 633
		area->nr_free++;
		set_page_order(&page[size], high);
	}
}

/*
 * This page is about to be returned from the page allocator
 */
N
Nick Piggin 已提交
634
static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
L
Linus Torvalds 已提交
635
{
N
Nick Piggin 已提交
636 637 638
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
		(page_count(page) != 0)  |
639
		(page->flags & PAGE_FLAGS_CHECK_AT_PREP))) {
N
Nick Piggin 已提交
640
		bad_page(page);
641
		return 1;
642
	}
643

H
Hugh Dickins 已提交
644
	set_page_private(page, 0);
645
	set_page_refcounted(page);
N
Nick Piggin 已提交
646 647

	arch_alloc_page(page, order);
L
Linus Torvalds 已提交
648
	kernel_map_pages(page, 1 << order, 1);
N
Nick Piggin 已提交
649 650 651 652 653 654 655

	if (gfp_flags & __GFP_ZERO)
		prep_zero_page(page, order, gfp_flags);

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

656
	return 0;
L
Linus Torvalds 已提交
657 658
}

659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689
/*
 * 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;
}


690 691 692 693 694
/*
 * 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] = {
695 696 697 698
	[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 */
699 700
};

701 702
/*
 * Move the free pages in a range to the free lists of the requested type.
703
 * Note that start_page and end_pages are not aligned on a pageblock
704 705
 * boundary. If alignment is required, use move_freepages_block()
 */
A
Adrian Bunk 已提交
706 707 708
static int move_freepages(struct zone *zone,
			  struct page *start_page, struct page *end_page,
			  int migratetype)
709 710 711
{
	struct page *page;
	unsigned long order;
712
	int pages_moved = 0;
713 714 715 716 717 718 719

#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
M
Mel Gorman 已提交
720
	 * grouping pages by mobility
721 722 723 724 725
	 */
	BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif

	for (page = start_page; page <= end_page;) {
726 727 728
		/* Make sure we are not inadvertently changing nodes */
		VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));

729 730 731 732 733 734 735 736 737 738 739 740 741 742 743
		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;
744
		pages_moved += 1 << order;
745 746
	}

747
	return pages_moved;
748 749
}

A
Adrian Bunk 已提交
750 751
static int move_freepages_block(struct zone *zone, struct page *page,
				int migratetype)
752 753 754 755 756
{
	unsigned long start_pfn, end_pfn;
	struct page *start_page, *end_page;

	start_pfn = page_to_pfn(page);
757
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
758
	start_page = pfn_to_page(start_pfn);
759 760
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
761 762 763 764 765 766 767 768 769 770

	/* 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);
}

771 772 773 774 775 776 777 778 779 780 781 782 783 784 785
/* 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];

786 787 788
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
				continue;
M
Mel Gorman 已提交
789

790 791 792 793 794 795 796 797 798
			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--;

			/*
799
			 * If breaking a large block of pages, move all free
800 801 802
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
			 * agressive about taking ownership of free pages
803
			 */
804
			if (unlikely(current_order >= (pageblock_order >> 1)) ||
805 806 807 808 809 810
					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 */
811
				if (pages >= (1 << (pageblock_order-1)))
812 813 814
					set_pageblock_migratetype(page,
								start_migratetype);

815
				migratetype = start_migratetype;
816
			}
817 818 819 820 821 822 823

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

824
			if (current_order == pageblock_order)
825 826 827 828 829 830 831 832
				set_pageblock_migratetype(page,
							start_migratetype);

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

833 834
	/* Use MIGRATE_RESERVE rather than fail an allocation */
	return __rmqueue_smallest(zone, order, MIGRATE_RESERVE);
835 836
}

837
/*
L
Linus Torvalds 已提交
838 839 840
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
841 842
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
L
Linus Torvalds 已提交
843 844 845
{
	struct page *page;

846
	page = __rmqueue_smallest(zone, order, migratetype);
847

848 849
	if (unlikely(!page))
		page = __rmqueue_fallback(zone, order, migratetype);
850 851

	return page;
L
Linus Torvalds 已提交
852 853 854 855 856 857 858 859
}

/* 
 * 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, 
860 861
			unsigned long count, struct list_head *list,
			int migratetype)
L
Linus Torvalds 已提交
862 863 864
{
	int i;
	
N
Nick Piggin 已提交
865
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
866
	for (i = 0; i < count; ++i) {
867
		struct page *page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
868
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
869
			break;
870 871 872 873 874 875 876 877 878 879

		/*
		 * 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.
		 */
880 881
		list_add(&page->lru, list);
		set_page_private(page, migratetype);
882
		list = &page->lru;
L
Linus Torvalds 已提交
883
	}
N
Nick Piggin 已提交
884
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
885
	return i;
L
Linus Torvalds 已提交
886 887
}

888
#ifdef CONFIG_NUMA
889
/*
890 891 892 893
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
894 895
 * Note that this function must be called with the thread pinned to
 * a single processor.
896
 */
897
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
898 899
{
	unsigned long flags;
900
	int to_drain;
901

902 903 904 905 906 907 908 909
	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);
910 911 912
}
#endif

913 914 915 916 917 918 919 920
/*
 * 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)
L
Linus Torvalds 已提交
921
{
N
Nick Piggin 已提交
922
	unsigned long flags;
L
Linus Torvalds 已提交
923 924 925 926
	struct zone *zone;

	for_each_zone(zone) {
		struct per_cpu_pageset *pset;
927
		struct per_cpu_pages *pcp;
L
Linus Torvalds 已提交
928

929 930 931
		if (!populated_zone(zone))
			continue;

932
		pset = zone_pcp(zone, cpu);
933 934 935 936 937 938

		pcp = &pset->pcp;
		local_irq_save(flags);
		free_pages_bulk(zone, pcp->count, &pcp->list, 0);
		pcp->count = 0;
		local_irq_restore(flags);
L
Linus Torvalds 已提交
939 940 941
	}
}

942 943 944 945 946 947 948 949 950 951 952 953 954
/*
 * 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)
{
955
	on_each_cpu(drain_local_pages, NULL, 1);
956 957
}

958
#ifdef CONFIG_HIBERNATION
L
Linus Torvalds 已提交
959 960 961

void mark_free_pages(struct zone *zone)
{
962 963
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
964
	int order, t;
L
Linus Torvalds 已提交
965 966 967 968 969 970
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
971 972 973 974 975 976

	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);

977 978
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
979
		}
L
Linus Torvalds 已提交
980

981 982
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
983
			unsigned long i;
L
Linus Torvalds 已提交
984

985 986
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
987
				swsusp_set_page_free(pfn_to_page(pfn + i));
988
		}
989
	}
L
Linus Torvalds 已提交
990 991
	spin_unlock_irqrestore(&zone->lock, flags);
}
992
#endif /* CONFIG_PM */
L
Linus Torvalds 已提交
993 994 995 996

/*
 * Free a 0-order page
 */
H
Harvey Harrison 已提交
997
static void free_hot_cold_page(struct page *page, int cold)
L
Linus Torvalds 已提交
998 999 1000 1001 1002 1003 1004
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;

	if (PageAnon(page))
		page->mapping = NULL;
N
Nick Piggin 已提交
1005
	if (free_pages_check(page))
1006 1007
		return;

1008
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
1009
		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
1010 1011
		debug_check_no_obj_freed(page_address(page), PAGE_SIZE);
	}
N
Nick Piggin 已提交
1012
	arch_free_page(page, 0);
1013 1014
	kernel_map_pages(page, 1, 0);

1015
	pcp = &zone_pcp(zone, get_cpu())->pcp;
L
Linus Torvalds 已提交
1016
	local_irq_save(flags);
1017
	__count_vm_event(PGFREE);
1018 1019 1020 1021
	if (cold)
		list_add_tail(&page->lru, &pcp->list);
	else
		list_add(&page->lru, &pcp->list);
1022
	set_page_private(page, get_pageblock_migratetype(page));
L
Linus Torvalds 已提交
1023
	pcp->count++;
N
Nick Piggin 已提交
1024 1025 1026 1027
	if (pcp->count >= pcp->high) {
		free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
		pcp->count -= pcp->batch;
	}
L
Linus Torvalds 已提交
1028 1029 1030 1031
	local_irq_restore(flags);
	put_cpu();
}

H
Harvey Harrison 已提交
1032
void free_hot_page(struct page *page)
L
Linus Torvalds 已提交
1033 1034 1035 1036
{
	free_hot_cold_page(page, 0);
}
	
H
Harvey Harrison 已提交
1037
void free_cold_page(struct page *page)
L
Linus Torvalds 已提交
1038 1039 1040 1041
{
	free_hot_cold_page(page, 1);
}

N
Nick Piggin 已提交
1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053
/*
 * 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;

N
Nick Piggin 已提交
1054 1055
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1056 1057
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
1058 1059
}

L
Linus Torvalds 已提交
1060 1061 1062 1063 1064
/*
 * 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.
 */
1065
static struct page *buffered_rmqueue(struct zone *preferred_zone,
N
Nick Piggin 已提交
1066
			struct zone *zone, int order, gfp_t gfp_flags)
L
Linus Torvalds 已提交
1067 1068
{
	unsigned long flags;
1069
	struct page *page;
L
Linus Torvalds 已提交
1070
	int cold = !!(gfp_flags & __GFP_COLD);
N
Nick Piggin 已提交
1071
	int cpu;
1072
	int migratetype = allocflags_to_migratetype(gfp_flags);
L
Linus Torvalds 已提交
1073

1074
again:
N
Nick Piggin 已提交
1075
	cpu  = get_cpu();
N
Nick Piggin 已提交
1076
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1077 1078
		struct per_cpu_pages *pcp;

1079
		pcp = &zone_pcp(zone, cpu)->pcp;
L
Linus Torvalds 已提交
1080
		local_irq_save(flags);
N
Nick Piggin 已提交
1081
		if (!pcp->count) {
1082
			pcp->count = rmqueue_bulk(zone, 0,
1083
					pcp->batch, &pcp->list, migratetype);
N
Nick Piggin 已提交
1084 1085
			if (unlikely(!pcp->count))
				goto failed;
L
Linus Torvalds 已提交
1086
		}
1087

1088
		/* Find a page of the appropriate migrate type */
1089 1090 1091 1092 1093 1094 1095 1096 1097
		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;
		}
1098

1099 1100
		/* Allocate more to the pcp list if necessary */
		if (unlikely(&page->lru == &pcp->list)) {
1101 1102 1103 1104
			pcp->count += rmqueue_bulk(zone, 0,
					pcp->batch, &pcp->list, migratetype);
			page = list_entry(pcp->list.next, struct page, lru);
		}
1105 1106 1107

		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1108
	} else {
L
Linus Torvalds 已提交
1109
		spin_lock_irqsave(&zone->lock, flags);
1110
		page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1111 1112 1113
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
L
Linus Torvalds 已提交
1114 1115
	}

1116
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1117
	zone_statistics(preferred_zone, zone);
N
Nick Piggin 已提交
1118 1119
	local_irq_restore(flags);
	put_cpu();
L
Linus Torvalds 已提交
1120

N
Nick Piggin 已提交
1121
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1122
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1123
		goto again;
L
Linus Torvalds 已提交
1124
	return page;
N
Nick Piggin 已提交
1125 1126 1127 1128 1129

failed:
	local_irq_restore(flags);
	put_cpu();
	return NULL;
L
Linus Torvalds 已提交
1130 1131
}

R
Rohit Seth 已提交
1132
#define ALLOC_NO_WATERMARKS	0x01 /* don't check watermarks at all */
1133 1134 1135 1136 1137 1138
#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
1139

1140 1141 1142 1143 1144 1145 1146
#ifdef CONFIG_FAIL_PAGE_ALLOC

static struct fail_page_alloc_attr {
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1147
	u32 min_order;
1148 1149 1150 1151 1152

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

	struct dentry *ignore_gfp_highmem_file;
	struct dentry *ignore_gfp_wait_file;
1153
	struct dentry *min_order_file;
1154 1155 1156 1157 1158

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1159 1160
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1161
	.min_order = 1,
1162 1163 1164 1165 1166 1167 1168 1169 1170 1171
};

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)
{
1172 1173
	if (order < fail_page_alloc.min_order)
		return 0;
1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204
	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);
1205 1206 1207
	fail_page_alloc.min_order_file =
		debugfs_create_u32("min-order", mode, dir,
				   &fail_page_alloc.min_order);
1208 1209

	if (!fail_page_alloc.ignore_gfp_wait_file ||
1210 1211
            !fail_page_alloc.ignore_gfp_highmem_file ||
            !fail_page_alloc.min_order_file) {
1212 1213 1214
		err = -ENOMEM;
		debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
		debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1215
		debugfs_remove(fail_page_alloc.min_order_file);
1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234
		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
1235 1236 1237 1238 1239
/*
 * 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
1240
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
1241 1242
{
	/* free_pages my go negative - that's OK */
1243 1244
	long min = mark;
	long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
L
Linus Torvalds 已提交
1245 1246
	int o;

R
Rohit Seth 已提交
1247
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1248
		min -= min / 2;
R
Rohit Seth 已提交
1249
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266
		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;
}

1267 1268 1269 1270 1271 1272
#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
1273
 * that have to skip over a lot of full or unallowed zones.
1274 1275 1276
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1277
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298
 *
 * 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
1299
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1300 1301 1302 1303 1304 1305
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1306
					&node_states[N_HIGH_MEMORY];
1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331
	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.
 */
1332
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1333 1334 1335 1336 1337 1338 1339 1340 1341 1342
						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;

1343
	i = z - zonelist->_zonerefs;
1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354
	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.
 */
1355
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1356 1357 1358 1359 1360 1361 1362 1363
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

1364
	i = z - zonelist->_zonerefs;
1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

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

1376
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1377 1378 1379 1380 1381
				nodemask_t *allowednodes)
{
	return 1;
}

1382
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1383 1384 1385 1386
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1387
/*
1388
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1389 1390 1391
 * a page.
 */
static struct page *
1392
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1393
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags)
M
Martin Hicks 已提交
1394
{
1395
	struct zoneref *z;
R
Rohit Seth 已提交
1396
	struct page *page = NULL;
1397
	int classzone_idx;
1398
	struct zone *zone, *preferred_zone;
1399 1400 1401
	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 */
1402

1403 1404
	(void)first_zones_zonelist(zonelist, high_zoneidx, nodemask,
							&preferred_zone);
1405 1406 1407
	if (!preferred_zone)
		return NULL;

1408
	classzone_idx = zone_idx(preferred_zone);
R
Rohit Seth 已提交
1409

1410
zonelist_scan:
R
Rohit Seth 已提交
1411
	/*
1412
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1413 1414
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1415 1416
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1417 1418 1419
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1420
		if ((alloc_flags & ALLOC_CPUSET) &&
1421
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1422
				goto try_next_zone;
R
Rohit Seth 已提交
1423 1424

		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1425 1426
			unsigned long mark;
			if (alloc_flags & ALLOC_WMARK_MIN)
1427
				mark = zone->pages_min;
1428
			else if (alloc_flags & ALLOC_WMARK_LOW)
1429
				mark = zone->pages_low;
1430
			else
1431
				mark = zone->pages_high;
1432 1433
			if (!zone_watermark_ok(zone, order, mark,
				    classzone_idx, alloc_flags)) {
1434
				if (!zone_reclaim_mode ||
1435
				    !zone_reclaim(zone, gfp_mask, order))
1436
					goto this_zone_full;
1437
			}
R
Rohit Seth 已提交
1438 1439
		}

1440
		page = buffered_rmqueue(preferred_zone, zone, order, gfp_mask);
1441
		if (page)
R
Rohit Seth 已提交
1442
			break;
1443 1444 1445 1446 1447 1448 1449 1450 1451 1452
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;
		}
1453
	}
1454 1455 1456 1457 1458 1459

	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
1460
	return page;
M
Martin Hicks 已提交
1461 1462
}

L
Linus Torvalds 已提交
1463 1464 1465
/*
 * This is the 'heart' of the zoned buddy allocator.
 */
1466
struct page *
1467 1468
__alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
			struct zonelist *zonelist, nodemask_t *nodemask)
L
Linus Torvalds 已提交
1469
{
A
Al Viro 已提交
1470
	const gfp_t wait = gfp_mask & __GFP_WAIT;
1471
	enum zone_type high_zoneidx = gfp_zone(gfp_mask);
1472 1473
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
1474 1475 1476 1477
	struct page *page;
	struct reclaim_state reclaim_state;
	struct task_struct *p = current;
	int do_retry;
R
Rohit Seth 已提交
1478
	int alloc_flags;
1479 1480
	unsigned long did_some_progress;
	unsigned long pages_reclaimed = 0;
L
Linus Torvalds 已提交
1481 1482 1483

	might_sleep_if(wait);

1484 1485 1486
	if (should_fail_alloc_page(gfp_mask, order))
		return NULL;

1487
restart:
1488
	z = zonelist->_zonerefs;  /* the list of zones suitable for gfp_mask */
L
Linus Torvalds 已提交
1489

1490
	if (unlikely(!z->zone)) {
1491 1492 1493 1494
		/*
		 * 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
1495 1496
		return NULL;
	}
1497

1498
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
1499
			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET);
R
Rohit Seth 已提交
1500 1501
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1502

1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513
	/*
	 * 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;

1514 1515
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
		wakeup_kswapd(zone, order);
L
Linus Torvalds 已提交
1516

1517
	/*
R
Rohit Seth 已提交
1518 1519 1520 1521 1522 1523
	 * 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
1524 1525
	 * policy or is asking for __GFP_HIGH memory.  GFP_ATOMIC requests will
	 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1526
	 */
1527
	alloc_flags = ALLOC_WMARK_MIN;
R
Rohit Seth 已提交
1528 1529 1530 1531
	if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)
		alloc_flags |= ALLOC_HARDER;
	if (gfp_mask & __GFP_HIGH)
		alloc_flags |= ALLOC_HIGH;
1532 1533
	if (wait)
		alloc_flags |= ALLOC_CPUSET;
L
Linus Torvalds 已提交
1534 1535 1536

	/*
	 * Go through the zonelist again. Let __GFP_HIGH and allocations
R
Rohit Seth 已提交
1537
	 * coming from realtime tasks go deeper into reserves.
L
Linus Torvalds 已提交
1538 1539 1540
	 *
	 * This is the last chance, in general, before the goto nopage.
	 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1541
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
L
Linus Torvalds 已提交
1542
	 */
1543
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1544
						high_zoneidx, alloc_flags);
R
Rohit Seth 已提交
1545 1546
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1547 1548

	/* This allocation should allow future memory freeing. */
1549

1550
rebalance:
1551 1552 1553
	if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
			&& !in_interrupt()) {
		if (!(gfp_mask & __GFP_NOMEMALLOC)) {
K
Kirill Korotaev 已提交
1554
nofail_alloc:
1555
			/* go through the zonelist yet again, ignoring mins */
1556
			page = get_page_from_freelist(gfp_mask, nodemask, order,
1557
				zonelist, high_zoneidx, ALLOC_NO_WATERMARKS);
R
Rohit Seth 已提交
1558 1559
			if (page)
				goto got_pg;
K
Kirill Korotaev 已提交
1560
			if (gfp_mask & __GFP_NOFAIL) {
1561
				congestion_wait(WRITE, HZ/50);
K
Kirill Korotaev 已提交
1562 1563
				goto nofail_alloc;
			}
L
Linus Torvalds 已提交
1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574
		}
		goto nopage;
	}

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

	cond_resched();

	/* We now go into synchronous reclaim */
1575
	cpuset_memory_pressure_bump();
1576 1577 1578 1579
	/*
	 * The task's cpuset might have expanded its set of allowable nodes
	 */
	cpuset_update_task_memory_state();
L
Linus Torvalds 已提交
1580 1581 1582 1583
	p->flags |= PF_MEMALLOC;
	reclaim_state.reclaimed_slab = 0;
	p->reclaim_state = &reclaim_state;

1584
	did_some_progress = try_to_free_pages(zonelist, order, gfp_mask);
L
Linus Torvalds 已提交
1585 1586 1587 1588 1589 1590

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

	cond_resched();

1591
	if (order != 0)
1592
		drain_all_pages();
1593

L
Linus Torvalds 已提交
1594
	if (likely(did_some_progress)) {
1595
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1596
					zonelist, high_zoneidx, alloc_flags);
R
Rohit Seth 已提交
1597 1598
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
1599
	} else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1600
		if (!try_set_zone_oom(zonelist, gfp_mask)) {
1601 1602 1603 1604
			schedule_timeout_uninterruptible(1);
			goto restart;
		}

L
Linus Torvalds 已提交
1605 1606 1607 1608 1609 1610
		/*
		 * 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.
		 */
1611 1612 1613
		page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
			order, zonelist, high_zoneidx,
			ALLOC_WMARK_HIGH|ALLOC_CPUSET);
1614
		if (page) {
1615
			clear_zonelist_oom(zonelist, gfp_mask);
R
Rohit Seth 已提交
1616
			goto got_pg;
1617
		}
L
Linus Torvalds 已提交
1618

1619
		/* The OOM killer will not help higher order allocs so fail */
1620
		if (order > PAGE_ALLOC_COSTLY_ORDER) {
1621
			clear_zonelist_oom(zonelist, gfp_mask);
1622
			goto nopage;
1623
		}
1624

1625
		out_of_memory(zonelist, gfp_mask, order);
1626
		clear_zonelist_oom(zonelist, gfp_mask);
L
Linus Torvalds 已提交
1627 1628 1629 1630 1631 1632 1633
		goto restart;
	}

	/*
	 * Don't let big-order allocations loop unless the caller explicitly
	 * requests that.  Wait for some write requests to complete then retry.
	 *
1634 1635
	 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
	 * means __GFP_NOFAIL, but that may not be true in other
1636
	 * implementations.
1637 1638 1639 1640 1641 1642
	 *
	 * 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
1643
	 */
1644
	pages_reclaimed += did_some_progress;
L
Linus Torvalds 已提交
1645 1646
	do_retry = 0;
	if (!(gfp_mask & __GFP_NORETRY)) {
1647
		if (order <= PAGE_ALLOC_COSTLY_ORDER) {
L
Linus Torvalds 已提交
1648
			do_retry = 1;
1649 1650 1651 1652 1653
		} else {
			if (gfp_mask & __GFP_REPEAT &&
				pages_reclaimed < (1 << order))
					do_retry = 1;
		}
L
Linus Torvalds 已提交
1654 1655 1656 1657
		if (gfp_mask & __GFP_NOFAIL)
			do_retry = 1;
	}
	if (do_retry) {
1658
		congestion_wait(WRITE, HZ/50);
L
Linus Torvalds 已提交
1659 1660 1661 1662 1663 1664 1665 1666 1667
		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
1668
		show_mem();
L
Linus Torvalds 已提交
1669 1670 1671 1672
	}
got_pg:
	return page;
}
1673
EXPORT_SYMBOL(__alloc_pages_internal);
L
Linus Torvalds 已提交
1674 1675 1676 1677

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
1678
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
1679 1680 1681 1682 1683 1684 1685 1686 1687 1688
{
	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
1689
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
1690 1691 1692 1693 1694 1695 1696
{
	struct page * page;

	/*
	 * get_zeroed_page() returns a 32-bit address, which cannot represent
	 * a highmem page
	 */
N
Nick Piggin 已提交
1697
	VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
L
Linus Torvalds 已提交
1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714

	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
1715
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
1716
{
N
Nick Piggin 已提交
1717
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
1718 1719 1720 1721 1722 1723 1724 1725 1726
		if (order == 0)
			free_hot_page(page);
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
1727
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
1728 1729
{
	if (addr != 0) {
N
Nick Piggin 已提交
1730
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
1731 1732 1733 1734 1735 1736
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

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 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789
/**
 * 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
1790 1791
static unsigned int nr_free_zone_pages(int offset)
{
1792
	struct zoneref *z;
1793 1794
	struct zone *zone;

1795
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
1796 1797
	unsigned int sum = 0;

1798
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
1799

1800
	for_each_zone_zonelist(zone, z, zonelist, offset) {
1801 1802 1803 1804
		unsigned long size = zone->present_pages;
		unsigned long high = zone->pages_high;
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
1805 1806 1807 1808 1809 1810 1811 1812 1813 1814
	}

	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
1815
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
1816
}
1817
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
1818 1819 1820 1821 1822 1823

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
1824
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
1825
}
1826 1827

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
1828
{
1829
	if (NUMA_BUILD)
1830
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
1831 1832 1833 1834 1835 1836
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
1837
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851
	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;
1852
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
1853
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
1854
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
1855 1856
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
1857 1858 1859 1860
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873
	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)
{
1874
	int cpu;
L
Linus Torvalds 已提交
1875 1876 1877
	struct zone *zone;

	for_each_zone(zone) {
1878
		if (!populated_zone(zone))
L
Linus Torvalds 已提交
1879
			continue;
1880 1881 1882

		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
1883

1884
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
1885 1886
			struct per_cpu_pageset *pageset;

1887
			pageset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
1888

1889 1890 1891
			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
1892 1893 1894
		}
	}

L
Lee Schermerhorn 已提交
1895 1896 1897 1898 1899 1900 1901
	printk("Active_anon:%lu active_file:%lu inactive_anon:%lu\n"
		" inactive_file:%lu"
//TODO:  check/adjust line lengths
#ifdef CONFIG_UNEVICTABLE_LRU
		" unevictable:%lu"
#endif
		" dirty:%lu writeback:%lu unstable:%lu\n"
1902
		" free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
1903 1904 1905 1906
		global_page_state(NR_ACTIVE_ANON),
		global_page_state(NR_ACTIVE_FILE),
		global_page_state(NR_INACTIVE_ANON),
		global_page_state(NR_INACTIVE_FILE),
L
Lee Schermerhorn 已提交
1907 1908 1909
#ifdef CONFIG_UNEVICTABLE_LRU
		global_page_state(NR_UNEVICTABLE),
#endif
1910
		global_page_state(NR_FILE_DIRTY),
1911
		global_page_state(NR_WRITEBACK),
1912
		global_page_state(NR_UNSTABLE_NFS),
1913
		global_page_state(NR_FREE_PAGES),
1914 1915
		global_page_state(NR_SLAB_RECLAIMABLE) +
			global_page_state(NR_SLAB_UNRECLAIMABLE),
1916
		global_page_state(NR_FILE_MAPPED),
1917 1918
		global_page_state(NR_PAGETABLE),
		global_page_state(NR_BOUNCE));
L
Linus Torvalds 已提交
1919 1920 1921 1922

	for_each_zone(zone) {
		int i;

1923 1924 1925
		if (!populated_zone(zone))
			continue;

L
Linus Torvalds 已提交
1926 1927 1928 1929 1930 1931
		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
1932 1933 1934 1935
			" active_anon:%lukB"
			" inactive_anon:%lukB"
			" active_file:%lukB"
			" inactive_file:%lukB"
L
Lee Schermerhorn 已提交
1936 1937 1938
#ifdef CONFIG_UNEVICTABLE_LRU
			" unevictable:%lukB"
#endif
L
Linus Torvalds 已提交
1939 1940 1941 1942 1943
			" present:%lukB"
			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
1944
			K(zone_page_state(zone, NR_FREE_PAGES)),
L
Linus Torvalds 已提交
1945 1946 1947
			K(zone->pages_min),
			K(zone->pages_low),
			K(zone->pages_high),
1948 1949 1950 1951
			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
Lee Schermerhorn 已提交
1952 1953 1954
#ifdef CONFIG_UNEVICTABLE_LRU
			K(zone_page_state(zone, NR_UNEVICTABLE)),
#endif
L
Linus Torvalds 已提交
1955 1956
			K(zone->present_pages),
			zone->pages_scanned,
1957
			(zone_is_all_unreclaimable(zone) ? "yes" : "no")
L
Linus Torvalds 已提交
1958 1959 1960 1961 1962 1963 1964 1965
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

	for_each_zone(zone) {
1966
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
L
Linus Torvalds 已提交
1967

1968 1969 1970
		if (!populated_zone(zone))
			continue;

L
Linus Torvalds 已提交
1971 1972 1973 1974 1975
		show_node(zone);
		printk("%s: ", zone->name);

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
1976 1977
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
L
Linus Torvalds 已提交
1978 1979
		}
		spin_unlock_irqrestore(&zone->lock, flags);
1980 1981
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
L
Linus Torvalds 已提交
1982 1983 1984
		printk("= %lukB\n", K(total));
	}

1985 1986
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

L
Linus Torvalds 已提交
1987 1988 1989
	show_swap_cache_info();
}

1990 1991 1992 1993 1994 1995
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
1996 1997
/*
 * Builds allocation fallback zone lists.
1998 1999
 *
 * Add all populated zones of a node to the zonelist.
L
Linus Torvalds 已提交
2000
 */
2001 2002
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
2003
{
2004 2005
	struct zone *zone;

2006
	BUG_ON(zone_type >= MAX_NR_ZONES);
2007
	zone_type++;
2008 2009

	do {
2010
		zone_type--;
2011
		zone = pgdat->node_zones + zone_type;
2012
		if (populated_zone(zone)) {
2013 2014
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
2015
			check_highest_zone(zone_type);
L
Linus Torvalds 已提交
2016
		}
2017

2018
	} while (zone_type);
2019
	return nr_zones;
L
Linus Torvalds 已提交
2020 2021
}

2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042

/*
 *  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
2043
#ifdef CONFIG_NUMA
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 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114
/* 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
2115
#define MAX_NODE_LOAD (num_online_nodes())
2116 2117
static int node_load[MAX_NUMNODES];

L
Linus Torvalds 已提交
2118
/**
2119
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
Linus Torvalds 已提交
2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131
 * @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.
 */
2132
static int find_next_best_node(int node, nodemask_t *used_node_mask)
L
Linus Torvalds 已提交
2133
{
2134
	int n, val;
L
Linus Torvalds 已提交
2135 2136
	int min_val = INT_MAX;
	int best_node = -1;
2137
	node_to_cpumask_ptr(tmp, 0);
L
Linus Torvalds 已提交
2138

2139 2140 2141 2142 2143
	/* 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
2144

2145
	for_each_node_state(n, N_HIGH_MEMORY) {
L
Linus Torvalds 已提交
2146 2147 2148 2149 2150 2151 2152 2153

		/* 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);

2154 2155 2156
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

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2157
		/* Give preference to headless and unused nodes */
2158 2159
		node_to_cpumask_ptr_next(tmp, n);
		if (!cpus_empty(*tmp))
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2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177
			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;
}

2178 2179 2180 2181 2182 2183 2184

/*
 * 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)
L
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2185
{
2186
	int j;
L
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2187
	struct zonelist *zonelist;
2188

2189
	zonelist = &pgdat->node_zonelists[0];
2190
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2191 2192 2193
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
2194 2195
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2196 2197
}

2198 2199 2200 2201 2202 2203 2204 2205
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

2206 2207
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2208 2209
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2210 2211
}

2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226
/*
 * 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;

2227 2228 2229 2230 2231 2232 2233
	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)) {
2234 2235
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
2236
				check_highest_zone(zone_type);
2237 2238 2239
			}
		}
	}
2240 2241
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
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 2268 2269 2270 2271 2272 2273 2274 2275 2276
}

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.
         */
2277 2278
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309
	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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Linus Torvalds 已提交
2310
	nodemask_t used_mask;
2311 2312 2313
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
L
Linus Torvalds 已提交
2314 2315

	/* initialize zonelists */
2316
	for (i = 0; i < MAX_ZONELISTS; i++) {
L
Linus Torvalds 已提交
2317
		zonelist = pgdat->node_zonelists + i;
2318 2319
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
L
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2320 2321 2322 2323 2324 2325 2326
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
	load = num_online_nodes();
	prev_node = local_node;
	nodes_clear(used_mask);
2327 2328 2329 2330 2331

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

L
Linus Torvalds 已提交
2332
	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2333 2334 2335 2336 2337 2338 2339 2340 2341
		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;

L
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2342 2343 2344 2345 2346
		/*
		 * 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.
		 */
2347
		if (distance != node_distance(local_node, prev_node))
2348 2349
			node_load[node] = load;

L
Linus Torvalds 已提交
2350 2351
		prev_node = node;
		load--;
2352 2353 2354 2355 2356
		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
2357

2358 2359 2360
	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
2361
	}
2362 2363

	build_thisnode_zonelists(pgdat);
L
Linus Torvalds 已提交
2364 2365
}

2366
/* Construct the zonelist performance cache - see further mmzone.h */
2367
static void build_zonelist_cache(pg_data_t *pgdat)
2368
{
2369 2370
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
2371
	struct zoneref *z;
2372

2373 2374 2375
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2376 2377
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2378 2379
}

2380

L
Linus Torvalds 已提交
2381 2382
#else	/* CONFIG_NUMA */

2383 2384 2385 2386 2387 2388
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
2389
{
2390
	int node, local_node;
2391 2392
	enum zone_type j;
	struct zonelist *zonelist;
L
Linus Torvalds 已提交
2393 2394 2395

	local_node = pgdat->node_id;

2396 2397
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
2398

2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411
	/*
	 * 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
2412
	}
2413 2414 2415 2416 2417 2418 2419
	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);
	}

2420 2421
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
L
Linus Torvalds 已提交
2422 2423
}

2424
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2425
static void build_zonelist_cache(pg_data_t *pgdat)
2426
{
2427
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
2428 2429
}

L
Linus Torvalds 已提交
2430 2431
#endif	/* CONFIG_NUMA */

2432
/* return values int ....just for stop_machine() */
2433
static int __build_all_zonelists(void *dummy)
L
Linus Torvalds 已提交
2434
{
2435
	int nid;
2436 2437

	for_each_online_node(nid) {
2438 2439 2440 2441
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
2442
	}
2443 2444 2445
	return 0;
}

2446
void build_all_zonelists(void)
2447
{
2448 2449
	set_zonelist_order();

2450
	if (system_state == SYSTEM_BOOTING) {
2451
		__build_all_zonelists(NULL);
2452
		mminit_verify_zonelist();
2453 2454
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
2455
		/* we have to stop all cpus to guarantee there is no user
2456
		   of zonelist */
2457
		stop_machine(__build_all_zonelists, NULL, NULL);
2458 2459
		/* cpuset refresh routine should be here */
	}
2460
	vm_total_pages = nr_free_pagecache_pages();
2461 2462 2463 2464 2465 2466 2467
	/*
	 * 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
	 */
2468
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2469 2470 2471 2472 2473 2474
		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",
2475 2476
			num_online_nodes(),
			zonelist_order_name[current_zonelist_order],
2477
			page_group_by_mobility_disabled ? "off" : "on",
2478 2479 2480 2481
			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
2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496
}

/*
 * 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

2497
#ifndef CONFIG_MEMORY_HOTPLUG
2498
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
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Linus Torvalds 已提交
2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515
{
	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);
}
2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538
#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
L
Linus Torvalds 已提交
2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551

/*
 * 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))

2552
/*
2553
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567
 * 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;
2568 2569
	reserve = roundup(zone->pages_min, pageblock_nr_pages) >>
							pageblock_order;
2570

2571
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2572 2573 2574 2575
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

2576 2577 2578 2579
		/* Watch out for overlapping nodes */
		if (page_to_nid(page) != zone_to_nid(zone))
			continue;

2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609
		/* 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
2610

L
Linus Torvalds 已提交
2611 2612 2613 2614 2615
/*
 * 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.
 */
2616
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
2617
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
2618 2619
{
	struct page *page;
A
Andy Whitcroft 已提交
2620 2621
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
2622
	struct zone *z;
L
Linus Torvalds 已提交
2623

2624 2625 2626
	if (highest_memmap_pfn < end_pfn - 1)
		highest_memmap_pfn = end_pfn - 1;

2627
	z = &NODE_DATA(nid)->node_zones[zone];
2628
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639
		/*
		 * 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
2640 2641
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
2642
		mminit_verify_page_links(page, zone, nid, pfn);
2643
		init_page_count(page);
L
Linus Torvalds 已提交
2644 2645
		reset_page_mapcount(page);
		SetPageReserved(page);
2646 2647 2648 2649 2650
		/*
		 * 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
2651 2652 2653
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
2654 2655 2656 2657 2658
		 *
		 * 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.
2659
		 */
2660 2661 2662
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
2663
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2664

L
Linus Torvalds 已提交
2665 2666 2667 2668
		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))
2669
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
2670 2671 2672 2673
#endif
	}
}

2674
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
2675
{
2676 2677 2678
	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
2679 2680 2681 2682 2683 2684
		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
2685
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
2686 2687
#endif

2688
static int zone_batchsize(struct zone *zone)
2689 2690 2691 2692 2693
{
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
2694
	 * size of the zone.  But no more than 1/2 of a meg.
2695 2696 2697 2698
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
2699 2700
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
2701 2702 2703 2704 2705
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
2706 2707 2708
	 * 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.
2709
	 *
2710 2711 2712 2713
	 * 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.
2714
	 */
2715
	batch = (1 << (fls(batch + batch/2)-1)) - 1;
2716

2717 2718 2719
	return batch;
}

A
Adrian Bunk 已提交
2720
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
2721 2722 2723
{
	struct per_cpu_pages *pcp;

2724 2725
	memset(p, 0, sizeof(*p));

2726
	pcp = &p->pcp;
2727 2728 2729 2730 2731 2732
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
	INIT_LIST_HEAD(&pcp->list);
}

2733 2734 2735 2736 2737 2738 2739 2740 2741 2742
/*
 * 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;

2743
	pcp = &p->pcp;
2744 2745 2746 2747 2748 2749 2750
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}


2751 2752
#ifdef CONFIG_NUMA
/*
2753 2754 2755 2756 2757 2758 2759
 * 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.
2760 2761 2762 2763 2764 2765 2766 2767
 *
 * 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.
2768
 */
2769
static struct per_cpu_pageset boot_pageset[NR_CPUS];
2770 2771 2772

/*
 * Dynamically allocate memory for the
2773 2774
 * per cpu pageset array in struct zone.
 */
2775
static int __cpuinit process_zones(int cpu)
2776 2777
{
	struct zone *zone, *dzone;
2778 2779 2780
	int node = cpu_to_node(cpu);

	node_set_state(node, N_CPU);	/* this node has a cpu */
2781 2782 2783

	for_each_zone(zone) {

2784 2785 2786
		if (!populated_zone(zone))
			continue;

N
Nick Piggin 已提交
2787
		zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
2788
					 GFP_KERNEL, node);
N
Nick Piggin 已提交
2789
		if (!zone_pcp(zone, cpu))
2790 2791
			goto bad;

N
Nick Piggin 已提交
2792
		setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
2793 2794 2795 2796

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(zone_pcp(zone, cpu),
			 	(zone->present_pages / percpu_pagelist_fraction));
2797 2798 2799 2800 2801
	}

	return 0;
bad:
	for_each_zone(dzone) {
2802 2803
		if (!populated_zone(dzone))
			continue;
2804 2805
		if (dzone == zone)
			break;
N
Nick Piggin 已提交
2806 2807
		kfree(zone_pcp(dzone, cpu));
		zone_pcp(dzone, cpu) = NULL;
2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818
	}
	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);

2819 2820 2821
		/* Free per_cpu_pageset if it is slab allocated */
		if (pset != &boot_pageset[cpu])
			kfree(pset);
2822 2823 2824 2825
		zone_pcp(zone, cpu) = NULL;
	}
}

2826
static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
2827 2828 2829 2830 2831 2832 2833
		unsigned long action,
		void *hcpu)
{
	int cpu = (long)hcpu;
	int ret = NOTIFY_OK;

	switch (action) {
2834
	case CPU_UP_PREPARE:
2835
	case CPU_UP_PREPARE_FROZEN:
2836 2837 2838 2839
		if (process_zones(cpu))
			ret = NOTIFY_BAD;
		break;
	case CPU_UP_CANCELED:
2840
	case CPU_UP_CANCELED_FROZEN:
2841
	case CPU_DEAD:
2842
	case CPU_DEAD_FROZEN:
2843 2844 2845 2846
		free_zone_pagesets(cpu);
		break;
	default:
		break;
2847 2848 2849 2850
	}
	return ret;
}

2851
static struct notifier_block __cpuinitdata pageset_notifier =
2852 2853
	{ &pageset_cpuup_callback, NULL, 0 };

2854
void __init setup_per_cpu_pageset(void)
2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868
{
	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
2869
static noinline __init_refok
2870
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
2871 2872 2873
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
2874
	size_t alloc_size;
2875 2876 2877 2878 2879

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
2880 2881 2882 2883
	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);
2884 2885 2886
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

2887
	if (!slab_is_available()) {
2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900
		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.
		 */
2901
		zone->wait_table = vmalloc(alloc_size);
2902 2903 2904
	}
	if (!zone->wait_table)
		return -ENOMEM;
2905

2906
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
2907
		init_waitqueue_head(zone->wait_table + i);
2908 2909

	return 0;
2910 2911
}

2912
static __meminit void zone_pcp_init(struct zone *zone)
2913 2914 2915 2916 2917 2918 2919
{
	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
2920
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
2921 2922 2923 2924 2925
		setup_pageset(&boot_pageset[cpu],0);
#else
		setup_pageset(zone_pcp(zone,cpu), batch);
#endif
	}
A
Anton Blanchard 已提交
2926 2927 2928
	if (zone->present_pages)
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%lu\n",
			zone->name, zone->present_pages, batch);
2929 2930
}

2931 2932
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
2933 2934
					unsigned long size,
					enum memmap_context context)
2935 2936
{
	struct pglist_data *pgdat = zone->zone_pgdat;
2937 2938 2939 2940
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
2941 2942 2943 2944
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

2945 2946 2947 2948 2949 2950
	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));

2951
	zone_init_free_lists(zone);
2952 2953

	return 0;
2954 2955
}

2956 2957 2958 2959 2960
#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
 */
2961
static int __meminit first_active_region_index_in_nid(int nid)
2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973
{
	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
2974
 * Note: nid == MAX_NUMNODES returns next region regardless of node
2975
 */
2976
static int __meminit next_active_region_index_in_nid(int index, int nid)
2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991
{
	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
 */
2992
int __meminit early_pfn_to_nid(unsigned long pfn)
2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014
{
	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
3015 3016
 * @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
3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043
 *
 * 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);
	}
}

3044 3045 3046
void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
{
	int i;
3047
	int ret;
3048

3049 3050 3051 3052 3053 3054
	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;
	}
3055
}
3056 3057
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3058
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3059 3060 3061
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
3062
 * function may be used instead of calling memory_present() manually.
3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073
 */
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);
}

3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089
/**
 * 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)
{
3090 3091
	mminit_dprintk(MMINIT_TRACE, "zoneboundary",
			"Entering push_node_boundaries(%u, %lu, %lu)\n",
3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105
			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 */
3106
static void __meminit account_node_boundary(unsigned int nid,
3107 3108
		unsigned long *start_pfn, unsigned long *end_pfn)
{
3109 3110
	mminit_dprintk(MMINIT_TRACE, "zoneboundary",
			"Entering account_node_boundary(%u, %lu, %lu)\n",
3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126
			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) {}

3127
static void __meminit account_node_boundary(unsigned int nid,
3128 3129 3130 3131
		unsigned long *start_pfn, unsigned long *end_pfn) {}
#endif


3132 3133
/**
 * get_pfn_range_for_nid - Return the start and end page frames for a node
3134 3135 3136
 * @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.
3137 3138 3139 3140
 *
 * 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
3141
 * PFNs will be 0.
3142
 */
3143
void __meminit get_pfn_range_for_nid(unsigned int nid,
3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154
			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);
	}

3155
	if (*start_pfn == -1UL)
3156
		*start_pfn = 0;
3157 3158 3159

	/* Push the node boundaries out if requested */
	account_node_boundary(nid, start_pfn, end_pfn);
3160 3161
}

M
Mel Gorman 已提交
3162 3163 3164 3165 3166
/*
 * 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
3167
static void __init find_usable_zone_for_movable(void)
M
Mel Gorman 已提交
3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192
{
	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
3193
static void __meminit adjust_zone_range_for_zone_movable(int nid,
M
Mel Gorman 已提交
3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218
					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;
	}
}

3219 3220 3221 3222
/*
 * 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
3223
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3224 3225 3226 3227 3228 3229 3230 3231 3232 3233
					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
3234 3235 3236
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251

	/* 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,
3252
 * then all holes in the requested range will be accounted for.
3253
 */
A
Adrian Bunk 已提交
3254
static unsigned long __meminit __absent_pages_in_range(int nid,
3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266
				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;

3267 3268
	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);

3269 3270
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
3271
		hole_pages = prev_end_pfn - range_start_pfn;
3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291

	/* 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;
	}

3292 3293
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
3294
		hole_pages += range_end_pfn -
3295 3296
				max(range_start_pfn, prev_end_pfn);

3297 3298 3299 3300 3301 3302 3303 3304
	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
 *
3305
 * It returns the number of pages frames in memory holes within a range.
3306 3307 3308 3309 3310 3311 3312 3313
 */
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
3314
static unsigned long __meminit zone_absent_pages_in_node(int nid,
3315 3316 3317
					unsigned long zone_type,
					unsigned long *ignored)
{
3318 3319 3320 3321 3322 3323 3324 3325 3326
	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
3327 3328 3329
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
3330
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3331
}
3332

3333
#else
P
Paul Mundt 已提交
3334
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3335 3336 3337 3338 3339 3340
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
3341
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3342 3343 3344 3345 3346 3347 3348 3349
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
3350

3351 3352
#endif

3353
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373
		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);
}

3374 3375 3376
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
3377 3378
 * 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
3379 3380 3381 3382 3383 3384 3385
 * 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;

3386 3387
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398
	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;
3399
	if (usemapsize)
3400 3401 3402 3403 3404 3405 3406
		zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize);
}
#else
static void inline setup_usemap(struct pglist_data *pgdat,
				struct zone *zone, unsigned long zonesize) {}
#endif /* CONFIG_SPARSEMEM */

3407
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3408 3409 3410 3411 3412 3413 3414 3415 3416 3417

/* 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;
}

3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432
/* 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 */

3433 3434 3435 3436 3437 3438 3439 3440 3441 3442
/*
 * 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;
}
3443 3444 3445 3446
#define set_pageblock_order(x)	do {} while (0)

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
3447 3448 3449 3450 3451 3452
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
3453
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3454 3455
		unsigned long *zones_size, unsigned long *zholes_size)
{
3456
	enum zone_type j;
3457
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
3458
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
3459
	int ret;
L
Linus Torvalds 已提交
3460

3461
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
3462 3463 3464
	pgdat->nr_zones = 0;
	init_waitqueue_head(&pgdat->kswapd_wait);
	pgdat->kswapd_max_order = 0;
3465
	pgdat_page_cgroup_init(pgdat);
L
Linus Torvalds 已提交
3466 3467 3468
	
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
3469
		unsigned long size, realsize, memmap_pages;
3470
		enum lru_list l;
L
Linus Torvalds 已提交
3471

3472 3473 3474
		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
3475

3476 3477 3478 3479 3480
		/*
		 * 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
		 */
3481 3482
		memmap_pages =
			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
3483 3484
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
3485 3486 3487 3488
			if (memmap_pages)
				printk(KERN_DEBUG
				       "  %s zone: %lu pages used for memmap\n",
				       zone_names[j], memmap_pages);
3489 3490 3491 3492 3493
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

3494 3495
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
3496
			realsize -= dma_reserve;
Y
Yinghai Lu 已提交
3497
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
3498
					zone_names[0], dma_reserve);
3499 3500
		}

3501
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
3502 3503 3504 3505 3506
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
3507
#ifdef CONFIG_NUMA
3508
		zone->node = nid;
3509
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3510
						/ 100;
3511
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3512
#endif
L
Linus Torvalds 已提交
3513 3514 3515
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
3516
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
3517 3518
		zone->zone_pgdat = pgdat;

3519
		zone->prev_priority = DEF_PRIORITY;
L
Linus Torvalds 已提交
3520

3521
		zone_pcp_init(zone);
3522 3523 3524 3525
		for_each_lru(l) {
			INIT_LIST_HEAD(&zone->lru[l].list);
			zone->lru[l].nr_scan = 0;
		}
3526 3527 3528 3529
		zone->recent_rotated[0] = 0;
		zone->recent_rotated[1] = 0;
		zone->recent_scanned[0] = 0;
		zone->recent_scanned[1] = 0;
3530
		zap_zone_vm_stats(zone);
3531
		zone->flags = 0;
L
Linus Torvalds 已提交
3532 3533 3534
		if (!size)
			continue;

3535
		set_pageblock_order(pageblock_default_order());
3536
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
3537 3538
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
3539
		BUG_ON(ret);
3540
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
3541 3542 3543 3544
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
3545
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
3546 3547 3548 3549 3550
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
3551
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
3552 3553
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
3554
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
3555 3556
		struct page *map;

3557 3558 3559 3560 3561 3562 3563 3564 3565
		/*
		 * 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);
3566 3567 3568
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
3569
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
3570
	}
3571
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
3572 3573 3574
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
3575
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
3576
		mem_map = NODE_DATA(0)->node_mem_map;
3577 3578
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3579
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3580 3581
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
3582
#endif
A
Andy Whitcroft 已提交
3583
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
3584 3585
}

3586 3587
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
3588
{
3589 3590
	pg_data_t *pgdat = NODE_DATA(nid);

L
Linus Torvalds 已提交
3591 3592
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
3593
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
3594 3595

	alloc_node_mem_map(pgdat);
3596 3597 3598 3599 3600
#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
3601 3602 3603 3604

	free_area_init_core(pgdat, zones_size, zholes_size);
}

3605
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
M
Miklos Szeredi 已提交
3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625

#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

3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642
/**
 * 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;

3643 3644 3645 3646 3647
	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);
3648

3649 3650
	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);

3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689
	/* 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;
}

/**
3690
 * remove_active_range - Shrink an existing registered range of PFNs
3691
 * @nid: The node id the range is on that should be shrunk
3692 3693
 * @start_pfn: The new PFN of the range
 * @end_pfn: The new PFN of the range
3694 3695
 *
 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3696 3697 3698
 * 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.
3699
 */
3700 3701
void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
				unsigned long end_pfn)
3702
{
3703 3704
	int i, j;
	int removed = 0;
3705

3706 3707 3708
	printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
			  nid, start_pfn, end_pfn);

3709
	/* Find the old active region end and shrink */
3710
	for_each_active_range_index_in_nid(i, nid) {
3711 3712
		if (early_node_map[i].start_pfn >= start_pfn &&
		    early_node_map[i].end_pfn <= end_pfn) {
3713
			/* clear it */
3714
			early_node_map[i].start_pfn = 0;
3715 3716 3717 3718
			early_node_map[i].end_pfn = 0;
			removed = 1;
			continue;
		}
3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730
		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;
3731
			continue;
3732
		}
3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751
	}

	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--;
	}
3752 3753 3754 3755
}

/**
 * remove_all_active_ranges - Remove all currently registered regions
3756
 *
3757 3758 3759 3760
 * 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.
 */
3761
void __init remove_all_active_ranges(void)
3762 3763 3764
{
	memset(early_node_map, 0, sizeof(early_node_map));
	nr_nodemap_entries = 0;
3765 3766 3767 3768
#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 */
3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793
}

/* 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);
}

3794
/* Find the lowest pfn for a node */
A
Adrian Bunk 已提交
3795
static unsigned long __init find_min_pfn_for_node(int nid)
3796 3797
{
	int i;
3798
	unsigned long min_pfn = ULONG_MAX;
3799

3800 3801
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
3802
		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
3803

3804 3805
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
3806
			"Could not find start_pfn for node %d\n", nid);
3807 3808 3809 3810
		return 0;
	}

	return min_pfn;
3811 3812 3813 3814 3815 3816
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
3817
 * add_active_range().
3818 3819 3820 3821 3822 3823
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

3824 3825 3826 3827 3828
/*
 * 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
3829
static unsigned long __init early_calculate_totalpages(void)
3830 3831 3832 3833
{
	int i;
	unsigned long totalpages = 0;

3834 3835
	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long pages = early_node_map[i].end_pfn -
3836
						early_node_map[i].start_pfn;
3837 3838 3839 3840 3841
		totalpages += pages;
		if (pages)
			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
	}
  	return totalpages;
3842 3843
}

M
Mel Gorman 已提交
3844 3845 3846 3847 3848 3849
/*
 * 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
3850
static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
M
Mel Gorman 已提交
3851 3852 3853 3854
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
3855 3856
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
3857

3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879
	/*
	 * 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
3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890
	/* 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;
3891
	for_each_node_state(nid, N_HIGH_MEMORY) {
M
Mel Gorman 已提交
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 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980 3981 3982
		/*
		 * 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);
}

3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996
/* 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
}

3997 3998
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
3999
 * @max_zone_pfn: an array of max PFNs for each zone
4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012
 *
 * 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;
4013
	int i;
4014

4015 4016 4017
	/* Sort early_node_map as initialisation assumes it is sorted */
	sort_node_map();

4018 4019 4020 4021 4022 4023 4024 4025
	/* 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
4026 4027
		if (i == ZONE_MOVABLE)
			continue;
4028 4029 4030 4031 4032
		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
4033 4034 4035 4036 4037 4038
	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);
4039 4040 4041

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
M
Mel Gorman 已提交
4042 4043 4044
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
4045
		printk("  %-8s %0#10lx -> %0#10lx\n",
4046 4047 4048
				zone_names[i],
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);
M
Mel Gorman 已提交
4049 4050 4051 4052 4053 4054 4055 4056
	}

	/* 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]);
	}
4057 4058 4059 4060

	/* 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++)
4061
		printk("  %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4062 4063 4064 4065
						early_node_map[i].start_pfn,
						early_node_map[i].end_pfn);

	/* Initialise every node */
4066
	mminit_verify_pageflags_layout();
4067
	setup_nr_node_ids();
4068 4069
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
4070
		free_area_init_node(nid, NULL,
4071
				find_min_pfn_for_node(nid), NULL);
4072 4073 4074 4075 4076

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
4077 4078
	}
}
M
Mel Gorman 已提交
4079

4080
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
4081 4082 4083 4084 4085 4086
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
4087
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
4088

4089
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
4090 4091 4092 4093
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
4094

4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111 4112
/*
 * 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
4113
early_param("kernelcore", cmdline_parse_kernelcore);
4114
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
4115

4116 4117
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

4118
/**
4119 4120
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
4121 4122 4123 4124
 *
 * 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
4125 4126 4127
 * 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.
4128 4129 4130 4131 4132 4133
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

4134
#ifndef CONFIG_NEED_MULTIPLE_NODES
4135
struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] };
L
Linus Torvalds 已提交
4136
EXPORT_SYMBOL(contig_page_data);
4137
#endif
L
Linus Torvalds 已提交
4138 4139 4140

void __init free_area_init(unsigned long *zones_size)
{
4141
	free_area_init_node(0, zones_size,
L
Linus Torvalds 已提交
4142 4143 4144 4145 4146 4147 4148 4149
			__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;

4150
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4151 4152 4153 4154 4155 4156 4157 4158
		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.
		 */
4159
		vm_events_fold_cpu(cpu);
4160 4161 4162 4163 4164 4165 4166 4167

		/*
		 * 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.
		 */
4168
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
4169 4170 4171 4172 4173 4174 4175 4176 4177
	}
	return NOTIFY_OK;
}

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

4178 4179 4180 4181 4182 4183 4184 4185
/*
 * 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;
4186
	enum zone_type i, j;
4187 4188 4189 4190 4191 4192 4193 4194 4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209

	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
4210 4211 4212 4213 4214 4215 4216 4217 4218
/*
 * 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;
4219
	enum zone_type j, idx;
L
Linus Torvalds 已提交
4220

4221
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
4222 4223 4224 4225 4226 4227
		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;

4228 4229
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
4230 4231
				struct zone *lower_zone;

4232 4233
				idx--;

L
Linus Torvalds 已提交
4234 4235 4236 4237 4238 4239 4240 4241 4242 4243
				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;
			}
		}
	}
4244 4245 4246

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4247 4248
}

4249 4250 4251 4252 4253
/**
 * 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
4254
 */
4255
void setup_per_zone_pages_min(void)
L
Linus Torvalds 已提交
4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268
{
	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) {
4269 4270
		u64 tmp;

4271
		spin_lock_irqsave(&zone->lock, flags);
4272 4273
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
4274 4275
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
4276 4277 4278 4279 4280 4281 4282
			 * __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
4283 4284 4285 4286 4287 4288 4289 4290 4291 4292
			 */
			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
4293 4294
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
4295 4296
			 * proportionate to the zone's size.
			 */
N
Nick Piggin 已提交
4297
			zone->pages_min = tmp;
L
Linus Torvalds 已提交
4298 4299
		}

4300 4301
		zone->pages_low   = zone->pages_min + (tmp >> 2);
		zone->pages_high  = zone->pages_min + (tmp >> 1);
4302
		setup_zone_migrate_reserve(zone);
4303
		spin_unlock_irqrestore(&zone->lock, flags);
L
Linus Torvalds 已提交
4304
	}
4305 4306 4307

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4308 4309
}

4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 4330 4331 4332
/**
 * setup_per_zone_inactive_ratio - called when min_free_kbytes changes.
 *
 * The inactive anon list should be small enough that the VM never has to
 * do too much work, but large enough that each inactive page has a chance
 * to be referenced again before it is swapped out.
 *
 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
 * INACTIVE_ANON pages on this zone's LRU, maintained by the
 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
 * the anonymous pages are kept on the inactive list.
 *
 * total     target    max
 * memory    ratio     inactive anon
 * -------------------------------------
 *   10MB       1         5MB
 *  100MB       1        50MB
 *    1GB       3       250MB
 *   10GB      10       0.9GB
 *  100GB      31         3GB
 *    1TB     101        10GB
 *   10TB     320        32GB
 */
4333
static void setup_per_zone_inactive_ratio(void)
4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349
{
	struct zone *zone;

	for_each_zone(zone) {
		unsigned int gb, ratio;

		/* Zone size in gigabytes */
		gb = zone->present_pages >> (30 - PAGE_SHIFT);
		ratio = int_sqrt(10 * gb);
		if (!ratio)
			ratio = 1;

		zone->inactive_ratio = ratio;
	}
}

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Linus Torvalds 已提交
4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363 4364 4365 4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386
/*
 * 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();
4387
	setup_per_zone_inactive_ratio();
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	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);
4401 4402
	if (write)
		setup_per_zone_pages_min();
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	return 0;
}

4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417
#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)
4418
		zone->min_unmapped_pages = (zone->present_pages *
4419 4420 4421
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436 4437

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;
}
4438 4439
#endif

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Linus Torvalds 已提交
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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;
}

4457 4458 4459 4460 4461 4462 4463 4464 4465 4466 4467 4468 4469 4470 4471 4472 4473 4474 4475 4476 4477 4478 4479 4480 4481 4482
/*
 * 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;
}

4483
int hashdist = HASHDIST_DEFAULT;
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Linus Torvalds 已提交
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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 */
A
Andrew Morton 已提交
4518
		numentries = nr_kernel_pages;
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4519 4520 4521 4522 4523 4524 4525 4526 4527
		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);
4528 4529 4530 4531

		/* 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
4532
	}
4533
	numentries = roundup_pow_of_two(numentries);
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	/* 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;

4544
	log2qty = ilog2(numentries);
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Linus Torvalds 已提交
4545 4546 4547 4548

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
4549
			table = alloc_bootmem_nopanic(size);
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Linus Torvalds 已提交
4550 4551 4552
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
4553
			unsigned long order = get_order(size);
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Linus Torvalds 已提交
4554
			table = (void*) __get_free_pages(GFP_ATOMIC, order);
4555 4556 4557 4558 4559 4560 4561 4562 4563 4564 4565 4566 4567 4568 4569
			/*
			 * 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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Linus Torvalds 已提交
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		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

4576
	printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
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Linus Torvalds 已提交
4577 4578
	       tablename,
	       (1U << log2qty),
4579
	       ilog2(size) - PAGE_SHIFT,
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Linus Torvalds 已提交
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	       size);

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

	return table;
}
4589

4590 4591 4592 4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603 4604
/* 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);
4605
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4606 4607
#else
	pfn = pfn - zone->zone_start_pfn;
4608
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4609 4610 4611 4612
#endif /* CONFIG_SPARSEMEM */
}

/**
4613
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629 4630 4631 4632 4633 4634 4635
 * @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;
4636

4637 4638 4639 4640
	return flags;
}

/**
4641
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655 4656 4657 4658
 * @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);
4659 4660
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
4661 4662 4663 4664 4665 4666 4667

	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);
}
K
KAMEZAWA Hiroyuki 已提交
4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689 4690 4691 4692 4693

/*
 * 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)
4694
		drain_all_pages();
K
KAMEZAWA Hiroyuki 已提交
4695 4696 4697 4698 4699 4700 4701 4702 4703 4704 4705 4706 4707 4708 4709 4710
	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);
}
K
KAMEZAWA Hiroyuki 已提交
4711 4712 4713 4714 4715 4716 4717 4718 4719 4720 4721 4722 4723 4724 4725 4726 4727 4728 4729 4730 4731 4732 4733 4734 4735 4736 4737 4738 4739 4740 4741 4742 4743 4744 4745 4746 4747 4748 4749 4750 4751 4752 4753 4754 4755 4756 4757

#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