page_alloc.c 138.0 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/kmemcheck.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 <linux/kmemleak.h>
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#include <trace/events/kmem.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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gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
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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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static unsigned long __meminitdata nr_kernel_pages;
static 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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  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;
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int nr_online_nodes __read_mostly = 1;
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EXPORT_SYMBOL(nr_node_ids);
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EXPORT_SYMBOL(nr_online_nodes);
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#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)
{
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	if (unlikely(page_group_by_mobility_disabled))
		migratetype = MIGRATE_UNMOVABLE;

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	set_pageblock_flags_group(page, (unsigned long)migratetype,
					PB_migrate, PB_migrate_end);
}

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bool oom_killer_disabled __read_mostly;

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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;
	}
}

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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) {
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		VM_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,
		int migratetype)
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{
	unsigned long page_idx;

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	if (unlikely(PageCompound(page)))
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		if (unlikely(destroy_compound_page(page, order)))
			return;
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	VM_BUG_ON(migratetype == -1);

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

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	VM_BUG_ON(page_idx & ((1 << order) - 1));
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	VM_BUG_ON(bad_range(zone, page));
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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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#ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
/*
 * free_page_mlock() -- clean up attempts to free and mlocked() page.
 * Page should not be on lru, so no need to fix that up.
 * free_pages_check() will verify...
 */
static inline void free_page_mlock(struct page *page)
{
	__dec_zone_page_state(page, NR_MLOCK);
	__count_vm_event(UNEVICTABLE_MLOCKFREED);
}
#else
static void free_page_mlock(struct page *page) { }
#endif

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static inline int free_pages_check(struct page *page)
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{
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	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
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		(atomic_read(&page->_count) != 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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	__mod_zone_page_state(zone, NR_FREE_PAGES, count << order);
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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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		trace_mm_page_pcpu_drain(page, order, page_private(page));
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		__free_one_page(page, zone, order, page_private(page));
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	}
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	spin_unlock(&zone->lock);
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}

545 546
static void free_one_page(struct zone *zone, struct page *page, int order,
				int migratetype)
L
Linus Torvalds 已提交
547
{
548
	spin_lock(&zone->lock);
549
	zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
550
	zone->pages_scanned = 0;
551 552

	__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
553
	__free_one_page(page, zone, order, migratetype);
554
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
555 556 557 558 559
}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
L
Linus Torvalds 已提交
560
	int i;
561
	int bad = 0;
562
	int wasMlocked = __TestClearPageMlocked(page);
L
Linus Torvalds 已提交
563

564 565
	kmemcheck_free_shadow(page, order);

L
Linus Torvalds 已提交
566
	for (i = 0 ; i < (1 << order) ; ++i)
567 568
		bad += free_pages_check(page + i);
	if (bad)
569 570
		return;

571
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
572
		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
573 574 575
		debug_check_no_obj_freed(page_address(page),
					   PAGE_SIZE << order);
	}
N
Nick Piggin 已提交
576
	arch_free_page(page, order);
N
Nick Piggin 已提交
577
	kernel_map_pages(page, 1 << order, 0);
N
Nick Piggin 已提交
578

N
Nick Piggin 已提交
579
	local_irq_save(flags);
580
	if (unlikely(wasMlocked))
581
		free_page_mlock(page);
582
	__count_vm_events(PGFREE, 1 << order);
583 584
	free_one_page(page_zone(page), page, order,
					get_pageblock_migratetype(page));
N
Nick Piggin 已提交
585
	local_irq_restore(flags);
L
Linus Torvalds 已提交
586 587
}

588 589 590
/*
 * permit the bootmem allocator to evade page validation on high-order frees
 */
591
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
592 593 594 595
{
	if (order == 0) {
		__ClearPageReserved(page);
		set_page_count(page, 0);
596
		set_page_refcounted(page);
N
Nick Piggin 已提交
597
		__free_page(page);
598 599 600
	} else {
		int loop;

N
Nick Piggin 已提交
601
		prefetchw(page);
602 603 604
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

N
Nick Piggin 已提交
605 606
			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
607 608 609 610
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

611
		set_page_refcounted(page);
N
Nick Piggin 已提交
612
		__free_pages(page, order);
613 614 615
	}
}

L
Linus Torvalds 已提交
616 617 618 619 620 621 622 623 624 625 626 627 628 629 630

/*
 * 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
631
static inline void expand(struct zone *zone, struct page *page,
632 633
	int low, int high, struct free_area *area,
	int migratetype)
L
Linus Torvalds 已提交
634 635 636 637 638 639 640
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
641
		VM_BUG_ON(bad_range(zone, &page[size]));
642
		list_add(&page[size].lru, &area->free_list[migratetype]);
L
Linus Torvalds 已提交
643 644 645 646 647 648 649 650
		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
651
static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
L
Linus Torvalds 已提交
652
{
N
Nick Piggin 已提交
653 654
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
655
		(atomic_read(&page->_count) != 0)  |
656
		(page->flags & PAGE_FLAGS_CHECK_AT_PREP))) {
N
Nick Piggin 已提交
657
		bad_page(page);
658
		return 1;
659
	}
660

H
Hugh Dickins 已提交
661
	set_page_private(page, 0);
662
	set_page_refcounted(page);
N
Nick Piggin 已提交
663 664

	arch_alloc_page(page, order);
L
Linus Torvalds 已提交
665
	kernel_map_pages(page, 1 << order, 1);
N
Nick Piggin 已提交
666 667 668 669 670 671 672

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

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

673
	return 0;
L
Linus Torvalds 已提交
674 675
}

676 677 678 679
/*
 * Go through the free lists for the given migratetype and remove
 * the smallest available page from the freelists
 */
680 681
static inline
struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706
						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--;
		expand(zone, page, order, current_order, area, migratetype);
		return page;
	}

	return NULL;
}


707 708 709 710 711
/*
 * 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] = {
712 713 714 715
	[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 */
716 717
};

718 719
/*
 * Move the free pages in a range to the free lists of the requested type.
720
 * Note that start_page and end_pages are not aligned on a pageblock
721 722
 * boundary. If alignment is required, use move_freepages_block()
 */
A
Adrian Bunk 已提交
723 724 725
static int move_freepages(struct zone *zone,
			  struct page *start_page, struct page *end_page,
			  int migratetype)
726 727 728
{
	struct page *page;
	unsigned long order;
729
	int pages_moved = 0;
730 731 732 733 734 735 736

#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
737
	 * grouping pages by mobility
738 739 740 741 742
	 */
	BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif

	for (page = start_page; page <= end_page;) {
743 744 745
		/* Make sure we are not inadvertently changing nodes */
		VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));

746 747 748 749 750 751 752 753 754 755 756 757 758 759 760
		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;
761
		pages_moved += 1 << order;
762 763
	}

764
	return pages_moved;
765 766
}

A
Adrian Bunk 已提交
767 768
static int move_freepages_block(struct zone *zone, struct page *page,
				int migratetype)
769 770 771 772 773
{
	unsigned long start_pfn, end_pfn;
	struct page *start_page, *end_page;

	start_pfn = page_to_pfn(page);
774
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
775
	start_page = pfn_to_page(start_pfn);
776 777
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
778 779 780 781 782 783 784 785 786 787

	/* 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);
}

788 789 790 791 792 793 794 795 796 797 798
static void change_pageblock_range(struct page *pageblock_page,
					int start_order, int migratetype)
{
	int nr_pageblocks = 1 << (start_order - pageblock_order);

	while (nr_pageblocks--) {
		set_pageblock_migratetype(pageblock_page, migratetype);
		pageblock_page += pageblock_nr_pages;
	}
}

799
/* Remove an element from the buddy allocator from the fallback list */
800 801
static inline struct page *
__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
802 803 804 805 806 807 808 809 810 811 812 813
{
	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];

814 815 816
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
				continue;
M
Mel Gorman 已提交
817

818 819 820 821 822 823 824 825 826
			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--;

			/*
827
			 * If breaking a large block of pages, move all free
828 829 830
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
			 * agressive about taking ownership of free pages
831
			 */
832
			if (unlikely(current_order >= (pageblock_order >> 1)) ||
833 834
					start_migratetype == MIGRATE_RECLAIMABLE ||
					page_group_by_mobility_disabled) {
835 836 837 838 839
				unsigned long pages;
				pages = move_freepages_block(zone, page,
								start_migratetype);

				/* Claim the whole block if over half of it is free */
840 841
				if (pages >= (1 << (pageblock_order-1)) ||
						page_group_by_mobility_disabled)
842 843 844
					set_pageblock_migratetype(page,
								start_migratetype);

845
				migratetype = start_migratetype;
846
			}
847 848 849 850 851

			/* Remove the page from the freelists */
			list_del(&page->lru);
			rmv_page_order(page);

852 853 854
			/* Take ownership for orders >= pageblock_order */
			if (current_order >= pageblock_order)
				change_pageblock_range(page, current_order,
855 856 857
							start_migratetype);

			expand(zone, page, order, current_order, area, migratetype);
858 859 860 861

			trace_mm_page_alloc_extfrag(page, order, current_order,
				start_migratetype, migratetype);

862 863 864 865
			return page;
		}
	}

866
	return NULL;
867 868
}

869
/*
L
Linus Torvalds 已提交
870 871 872
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
873 874
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
L
Linus Torvalds 已提交
875 876 877
{
	struct page *page;

878
retry_reserve:
879
	page = __rmqueue_smallest(zone, order, migratetype);
880

881
	if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
882
		page = __rmqueue_fallback(zone, order, migratetype);
883

884 885 886 887 888 889 890 891 892 893 894
		/*
		 * Use MIGRATE_RESERVE rather than fail an allocation. goto
		 * is used because __rmqueue_smallest is an inline function
		 * and we want just one call site
		 */
		if (!page) {
			migratetype = MIGRATE_RESERVE;
			goto retry_reserve;
		}
	}

895
	trace_mm_page_alloc_zone_locked(page, order, migratetype);
896
	return page;
L
Linus Torvalds 已提交
897 898 899 900 901 902 903 904
}

/* 
 * 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, 
905
			unsigned long count, struct list_head *list,
906
			int migratetype, int cold)
L
Linus Torvalds 已提交
907 908 909
{
	int i;
	
N
Nick Piggin 已提交
910
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
911
	for (i = 0; i < count; ++i) {
912
		struct page *page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
913
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
914
			break;
915 916 917 918 919 920 921 922 923 924

		/*
		 * 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.
		 */
925 926 927 928
		if (likely(cold == 0))
			list_add(&page->lru, list);
		else
			list_add_tail(&page->lru, list);
929
		set_page_private(page, migratetype);
930
		list = &page->lru;
L
Linus Torvalds 已提交
931
	}
932
	__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
N
Nick Piggin 已提交
933
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
934
	return i;
L
Linus Torvalds 已提交
935 936
}

937
#ifdef CONFIG_NUMA
938
/*
939 940 941 942
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
943 944
 * Note that this function must be called with the thread pinned to
 * a single processor.
945
 */
946
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
947 948
{
	unsigned long flags;
949
	int to_drain;
950

951 952 953 954 955 956 957 958
	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);
959 960 961
}
#endif

962 963 964 965 966 967 968 969
/*
 * 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
970
{
N
Nick Piggin 已提交
971
	unsigned long flags;
L
Linus Torvalds 已提交
972 973
	struct zone *zone;

974
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
975
		struct per_cpu_pageset *pset;
976
		struct per_cpu_pages *pcp;
L
Linus Torvalds 已提交
977

978
		pset = zone_pcp(zone, cpu);
979 980 981 982 983 984

		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
985 986 987
	}
}

988 989 990 991 992 993 994 995 996 997 998 999 1000
/*
 * 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)
{
1001
	on_each_cpu(drain_local_pages, NULL, 1);
1002 1003
}

1004
#ifdef CONFIG_HIBERNATION
L
Linus Torvalds 已提交
1005 1006 1007

void mark_free_pages(struct zone *zone)
{
1008 1009
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
1010
	int order, t;
L
Linus Torvalds 已提交
1011 1012 1013 1014 1015 1016
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
1017 1018 1019 1020 1021 1022

	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);

1023 1024
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
1025
		}
L
Linus Torvalds 已提交
1026

1027 1028
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
1029
			unsigned long i;
L
Linus Torvalds 已提交
1030

1031 1032
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
1033
				swsusp_set_page_free(pfn_to_page(pfn + i));
1034
		}
1035
	}
L
Linus Torvalds 已提交
1036 1037
	spin_unlock_irqrestore(&zone->lock, flags);
}
1038
#endif /* CONFIG_PM */
L
Linus Torvalds 已提交
1039 1040 1041 1042

/*
 * Free a 0-order page
 */
H
Harvey Harrison 已提交
1043
static void free_hot_cold_page(struct page *page, int cold)
L
Linus Torvalds 已提交
1044 1045 1046 1047
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;
1048
	int wasMlocked = __TestClearPageMlocked(page);
L
Linus Torvalds 已提交
1049

1050 1051
	kmemcheck_free_shadow(page, 0);

L
Linus Torvalds 已提交
1052 1053
	if (PageAnon(page))
		page->mapping = NULL;
N
Nick Piggin 已提交
1054
	if (free_pages_check(page))
1055 1056
		return;

1057
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
1058
		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
1059 1060
		debug_check_no_obj_freed(page_address(page), PAGE_SIZE);
	}
N
Nick Piggin 已提交
1061
	arch_free_page(page, 0);
1062 1063
	kernel_map_pages(page, 1, 0);

1064
	pcp = &zone_pcp(zone, get_cpu())->pcp;
1065
	set_page_private(page, get_pageblock_migratetype(page));
L
Linus Torvalds 已提交
1066
	local_irq_save(flags);
1067
	if (unlikely(wasMlocked))
1068
		free_page_mlock(page);
1069
	__count_vm_event(PGFREE);
1070

1071 1072 1073 1074
	if (cold)
		list_add_tail(&page->lru, &pcp->list);
	else
		list_add(&page->lru, &pcp->list);
L
Linus Torvalds 已提交
1075
	pcp->count++;
N
Nick Piggin 已提交
1076 1077 1078 1079
	if (pcp->count >= pcp->high) {
		free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
		pcp->count -= pcp->batch;
	}
L
Linus Torvalds 已提交
1080 1081 1082 1083
	local_irq_restore(flags);
	put_cpu();
}

H
Harvey Harrison 已提交
1084
void free_hot_page(struct page *page)
L
Linus Torvalds 已提交
1085
{
1086
	trace_mm_page_free_direct(page, 0);
L
Linus Torvalds 已提交
1087 1088 1089
	free_hot_cold_page(page, 0);
}
	
N
Nick Piggin 已提交
1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101
/*
 * 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
1102 1103
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1104 1105 1106 1107 1108 1109 1110 1111 1112 1113

#ifdef CONFIG_KMEMCHECK
	/*
	 * Split shadow pages too, because free(page[0]) would
	 * otherwise free the whole shadow.
	 */
	if (kmemcheck_page_is_tracked(page))
		split_page(virt_to_page(page[0].shadow), order);
#endif

1114 1115
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
1116 1117
}

L
Linus Torvalds 已提交
1118 1119 1120 1121 1122
/*
 * 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.
 */
1123 1124
static inline
struct page *buffered_rmqueue(struct zone *preferred_zone,
1125 1126
			struct zone *zone, int order, gfp_t gfp_flags,
			int migratetype)
L
Linus Torvalds 已提交
1127 1128
{
	unsigned long flags;
1129
	struct page *page;
L
Linus Torvalds 已提交
1130
	int cold = !!(gfp_flags & __GFP_COLD);
N
Nick Piggin 已提交
1131
	int cpu;
L
Linus Torvalds 已提交
1132

1133
again:
N
Nick Piggin 已提交
1134
	cpu  = get_cpu();
N
Nick Piggin 已提交
1135
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1136 1137
		struct per_cpu_pages *pcp;

1138
		pcp = &zone_pcp(zone, cpu)->pcp;
L
Linus Torvalds 已提交
1139
		local_irq_save(flags);
N
Nick Piggin 已提交
1140
		if (!pcp->count) {
1141
			pcp->count = rmqueue_bulk(zone, 0,
1142 1143
					pcp->batch, &pcp->list,
					migratetype, cold);
N
Nick Piggin 已提交
1144 1145
			if (unlikely(!pcp->count))
				goto failed;
L
Linus Torvalds 已提交
1146
		}
1147

1148
		/* Find a page of the appropriate migrate type */
1149 1150 1151 1152 1153 1154 1155 1156 1157
		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;
		}
1158

1159 1160
		/* Allocate more to the pcp list if necessary */
		if (unlikely(&page->lru == &pcp->list)) {
1161 1162
			int get_one_page = 0;

1163
			pcp->count += rmqueue_bulk(zone, 0,
1164 1165
					pcp->batch, &pcp->list,
					migratetype, cold);
1166 1167 1168 1169 1170 1171 1172 1173 1174
			list_for_each_entry(page, &pcp->list, lru) {
				if (get_pageblock_migratetype(page) !=
					    MIGRATE_ISOLATE) {
					get_one_page = 1;
					break;
				}
			}
			if (!get_one_page)
				goto failed;
1175
		}
1176 1177 1178

		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1179
	} else {
1180 1181 1182 1183 1184 1185 1186 1187
		if (unlikely(gfp_flags & __GFP_NOFAIL)) {
			/*
			 * __GFP_NOFAIL is not to be used in new code.
			 *
			 * All __GFP_NOFAIL callers should be fixed so that they
			 * properly detect and handle allocation failures.
			 *
			 * We most definitely don't want callers attempting to
1188
			 * allocate greater than order-1 page units with
1189 1190
			 * __GFP_NOFAIL.
			 */
1191
			WARN_ON_ONCE(order > 1);
1192
		}
L
Linus Torvalds 已提交
1193
		spin_lock_irqsave(&zone->lock, flags);
1194
		page = __rmqueue(zone, order, migratetype);
1195
		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
N
Nick Piggin 已提交
1196 1197 1198
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
L
Linus Torvalds 已提交
1199 1200
	}

1201
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1202
	zone_statistics(preferred_zone, zone);
N
Nick Piggin 已提交
1203 1204
	local_irq_restore(flags);
	put_cpu();
L
Linus Torvalds 已提交
1205

N
Nick Piggin 已提交
1206
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1207
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1208
		goto again;
L
Linus Torvalds 已提交
1209
	return page;
N
Nick Piggin 已提交
1210 1211 1212 1213 1214

failed:
	local_irq_restore(flags);
	put_cpu();
	return NULL;
L
Linus Torvalds 已提交
1215 1216
}

1217 1218 1219 1220 1221 1222 1223 1224 1225
/* The ALLOC_WMARK bits are used as an index to zone->watermark */
#define ALLOC_WMARK_MIN		WMARK_MIN
#define ALLOC_WMARK_LOW		WMARK_LOW
#define ALLOC_WMARK_HIGH	WMARK_HIGH
#define ALLOC_NO_WATERMARKS	0x04 /* don't check watermarks at all */

/* Mask to get the watermark bits */
#define ALLOC_WMARK_MASK	(ALLOC_NO_WATERMARKS-1)

1226 1227 1228
#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
1229

1230 1231 1232 1233 1234 1235 1236
#ifdef CONFIG_FAIL_PAGE_ALLOC

static struct fail_page_alloc_attr {
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1237
	u32 min_order;
1238 1239 1240 1241 1242

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

	struct dentry *ignore_gfp_highmem_file;
	struct dentry *ignore_gfp_wait_file;
1243
	struct dentry *min_order_file;
1244 1245 1246 1247 1248

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1249 1250
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1251
	.min_order = 1,
1252 1253 1254 1255 1256 1257 1258 1259 1260 1261
};

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)
{
1262 1263
	if (order < fail_page_alloc.min_order)
		return 0;
1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294
	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);
1295 1296 1297
	fail_page_alloc.min_order_file =
		debugfs_create_u32("min-order", mode, dir,
				   &fail_page_alloc.min_order);
1298 1299

	if (!fail_page_alloc.ignore_gfp_wait_file ||
1300 1301
            !fail_page_alloc.ignore_gfp_highmem_file ||
            !fail_page_alloc.min_order_file) {
1302 1303 1304
		err = -ENOMEM;
		debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
		debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1305
		debugfs_remove(fail_page_alloc.min_order_file);
1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324
		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
1325 1326 1327 1328 1329
/*
 * 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
1330
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
1331 1332
{
	/* free_pages my go negative - that's OK */
1333 1334
	long min = mark;
	long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
L
Linus Torvalds 已提交
1335 1336
	int o;

R
Rohit Seth 已提交
1337
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1338
		min -= min / 2;
R
Rohit Seth 已提交
1339
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356
		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;
}

1357 1358 1359 1360 1361 1362
#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
1363
 * that have to skip over a lot of full or unallowed zones.
1364 1365 1366
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1367
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388
 *
 * 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
1389
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1390 1391 1392 1393 1394 1395
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1396
					&node_states[N_HIGH_MEMORY];
1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421
	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.
 */
1422
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1423 1424 1425 1426 1427 1428 1429 1430 1431 1432
						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;

1433
	i = z - zonelist->_zonerefs;
1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444
	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.
 */
1445
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1446 1447 1448 1449 1450 1451 1452 1453
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

1454
	i = z - zonelist->_zonerefs;
1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

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

1466
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1467 1468 1469 1470 1471
				nodemask_t *allowednodes)
{
	return 1;
}

1472
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1473 1474 1475 1476
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1477
/*
1478
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1479 1480 1481
 * a page.
 */
static struct page *
1482
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1483
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1484
		struct zone *preferred_zone, int migratetype)
M
Martin Hicks 已提交
1485
{
1486
	struct zoneref *z;
R
Rohit Seth 已提交
1487
	struct page *page = NULL;
1488
	int classzone_idx;
1489
	struct zone *zone;
1490 1491 1492
	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 */
1493

1494
	classzone_idx = zone_idx(preferred_zone);
1495
zonelist_scan:
R
Rohit Seth 已提交
1496
	/*
1497
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1498 1499
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1500 1501
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1502 1503 1504
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1505
		if ((alloc_flags & ALLOC_CPUSET) &&
1506
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1507
				goto try_next_zone;
R
Rohit Seth 已提交
1508

1509
		BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
R
Rohit Seth 已提交
1510
		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1511
			unsigned long mark;
1512 1513
			int ret;

1514
			mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533
			if (zone_watermark_ok(zone, order, mark,
				    classzone_idx, alloc_flags))
				goto try_this_zone;

			if (zone_reclaim_mode == 0)
				goto this_zone_full;

			ret = zone_reclaim(zone, gfp_mask, order);
			switch (ret) {
			case ZONE_RECLAIM_NOSCAN:
				/* did not scan */
				goto try_next_zone;
			case ZONE_RECLAIM_FULL:
				/* scanned but unreclaimable */
				goto this_zone_full;
			default:
				/* did we reclaim enough */
				if (!zone_watermark_ok(zone, order, mark,
						classzone_idx, alloc_flags))
1534
					goto this_zone_full;
1535
			}
R
Rohit Seth 已提交
1536 1537
		}

1538
try_this_zone:
1539 1540
		page = buffered_rmqueue(preferred_zone, zone, order,
						gfp_mask, migratetype);
1541
		if (page)
R
Rohit Seth 已提交
1542
			break;
1543 1544 1545 1546
this_zone_full:
		if (NUMA_BUILD)
			zlc_mark_zone_full(zonelist, z);
try_next_zone:
1547
		if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1548 1549 1550 1551
			/*
			 * we do zlc_setup after the first zone is tried but only
			 * if there are multiple nodes make it worthwhile
			 */
1552 1553 1554 1555
			allowednodes = zlc_setup(zonelist, alloc_flags);
			zlc_active = 1;
			did_zlc_setup = 1;
		}
1556
	}
1557 1558 1559 1560 1561 1562

	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
1563
	return page;
M
Martin Hicks 已提交
1564 1565
}

1566 1567 1568
static inline int
should_alloc_retry(gfp_t gfp_mask, unsigned int order,
				unsigned long pages_reclaimed)
L
Linus Torvalds 已提交
1569
{
1570 1571 1572
	/* Do not loop if specifically requested */
	if (gfp_mask & __GFP_NORETRY)
		return 0;
L
Linus Torvalds 已提交
1573

1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590
	/*
	 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
	 * means __GFP_NOFAIL, but that may not be true in other
	 * implementations.
	 */
	if (order <= PAGE_ALLOC_COSTLY_ORDER)
		return 1;

	/*
	 * 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.
	 */
	if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
		return 1;
1591

1592 1593 1594 1595 1596 1597
	/*
	 * Don't let big-order allocations loop unless the caller
	 * explicitly requests that.
	 */
	if (gfp_mask & __GFP_NOFAIL)
		return 1;
L
Linus Torvalds 已提交
1598

1599 1600
	return 0;
}
1601

1602 1603 1604
static inline struct page *
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1605 1606
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1607 1608 1609 1610 1611 1612
{
	struct page *page;

	/* Acquire the OOM killer lock for the zones in zonelist */
	if (!try_set_zone_oom(zonelist, gfp_mask)) {
		schedule_timeout_uninterruptible(1);
L
Linus Torvalds 已提交
1613 1614
		return NULL;
	}
1615

1616 1617 1618 1619 1620 1621 1622
	/*
	 * 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.
	 */
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
		order, zonelist, high_zoneidx,
1623
		ALLOC_WMARK_HIGH|ALLOC_CPUSET,
1624
		preferred_zone, migratetype);
R
Rohit Seth 已提交
1625
	if (page)
1626 1627 1628
		goto out;

	/* The OOM killer will not help higher order allocs */
1629
	if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_NOFAIL))
1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643
		goto out;

	/* Exhausted what can be done so it's blamo time */
	out_of_memory(zonelist, gfp_mask, order);

out:
	clear_zonelist_oom(zonelist, gfp_mask);
	return page;
}

/* The really slow allocator path where we enter direct reclaim */
static inline struct page *
__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1644
	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1645
	int migratetype, unsigned long *did_some_progress)
1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672
{
	struct page *page = NULL;
	struct reclaim_state reclaim_state;
	struct task_struct *p = current;

	cond_resched();

	/* We now go into synchronous reclaim */
	cpuset_memory_pressure_bump();
	p->flags |= PF_MEMALLOC;
	lockdep_set_current_reclaim_state(gfp_mask);
	reclaim_state.reclaimed_slab = 0;
	p->reclaim_state = &reclaim_state;

	*did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);

	p->reclaim_state = NULL;
	lockdep_clear_current_reclaim_state();
	p->flags &= ~PF_MEMALLOC;

	cond_resched();

	if (order != 0)
		drain_all_pages();

	if (likely(*did_some_progress))
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1673
					zonelist, high_zoneidx,
1674 1675
					alloc_flags, preferred_zone,
					migratetype);
1676 1677 1678
	return page;
}

L
Linus Torvalds 已提交
1679
/*
1680 1681
 * This is called in the allocator slow-path if the allocation request is of
 * sufficient urgency to ignore watermarks and take other desperate measures
L
Linus Torvalds 已提交
1682
 */
1683 1684 1685
static inline struct page *
__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1686 1687
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1688 1689 1690 1691 1692
{
	struct page *page;

	do {
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1693
			zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
1694
			preferred_zone, migratetype);
1695 1696

		if (!page && gfp_mask & __GFP_NOFAIL)
1697
			congestion_wait(BLK_RW_ASYNC, HZ/50);
1698 1699 1700 1701 1702 1703 1704 1705
	} while (!page && (gfp_mask & __GFP_NOFAIL));

	return page;
}

static inline
void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
						enum zone_type high_zoneidx)
L
Linus Torvalds 已提交
1706
{
1707 1708
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
1709

1710 1711 1712
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
		wakeup_kswapd(zone, order);
}
1713

1714 1715 1716 1717 1718 1719
static inline int
gfp_to_alloc_flags(gfp_t gfp_mask)
{
	struct task_struct *p = current;
	int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
	const gfp_t wait = gfp_mask & __GFP_WAIT;
L
Linus Torvalds 已提交
1720

1721 1722
	/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
	BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH);
1723

1724 1725 1726 1727 1728 1729
	/*
	 * The caller may dip into page reserves a bit more if the caller
	 * cannot run direct reclaim, or if the caller has realtime scheduling
	 * policy or is asking for __GFP_HIGH memory.  GFP_ATOMIC requests will
	 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
	 */
1730
	alloc_flags |= (gfp_mask & __GFP_HIGH);
L
Linus Torvalds 已提交
1731

1732 1733
	if (!wait) {
		alloc_flags |= ALLOC_HARDER;
1734
		/*
1735 1736
		 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
		 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1737
		 */
1738 1739 1740 1741 1742 1743 1744 1745 1746
		alloc_flags &= ~ALLOC_CPUSET;
	} else if (unlikely(rt_task(p)))
		alloc_flags |= ALLOC_HARDER;

	if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
		if (!in_interrupt() &&
		    ((p->flags & PF_MEMALLOC) ||
		     unlikely(test_thread_flag(TIF_MEMDIE))))
			alloc_flags |= ALLOC_NO_WATERMARKS;
L
Linus Torvalds 已提交
1747
	}
1748

1749 1750 1751
	return alloc_flags;
}

1752 1753 1754
static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1755 1756
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1757 1758 1759 1760 1761 1762 1763
{
	const gfp_t wait = gfp_mask & __GFP_WAIT;
	struct page *page = NULL;
	int alloc_flags;
	unsigned long pages_reclaimed = 0;
	unsigned long did_some_progress;
	struct task_struct *p = current;
L
Linus Torvalds 已提交
1764

1765 1766 1767 1768 1769 1770
	/*
	 * In the slowpath, we sanity check order to avoid ever trying to
	 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
	 * be using allocators in order of preference for an area that is
	 * too large.
	 */
1771 1772
	if (order >= MAX_ORDER) {
		WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
1773
		return NULL;
1774
	}
L
Linus Torvalds 已提交
1775

1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786
	/*
	 * 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;

1787
	wake_all_kswapd(order, zonelist, high_zoneidx);
L
Linus Torvalds 已提交
1788

1789
restart:
1790
	/*
R
Rohit Seth 已提交
1791 1792 1793
	 * 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.
1794
	 */
1795
	alloc_flags = gfp_to_alloc_flags(gfp_mask);
L
Linus Torvalds 已提交
1796

1797
	/* This is the last chance, in general, before the goto nopage. */
1798
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1799 1800
			high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
			preferred_zone, migratetype);
R
Rohit Seth 已提交
1801 1802
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1803

1804
rebalance:
1805
	/* Allocate without watermarks if the context allows */
1806 1807 1808 1809 1810 1811
	if (alloc_flags & ALLOC_NO_WATERMARKS) {
		page = __alloc_pages_high_priority(gfp_mask, order,
				zonelist, high_zoneidx, nodemask,
				preferred_zone, migratetype);
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
1812 1813 1814 1815 1816 1817
	}

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

1818 1819 1820 1821
	/* Avoid recursion of direct reclaim */
	if (p->flags & PF_MEMALLOC)
		goto nopage;

1822 1823 1824 1825
	/* Avoid allocations with no watermarks from looping endlessly */
	if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
		goto nopage;

1826 1827 1828 1829
	/* Try direct reclaim and then allocating */
	page = __alloc_pages_direct_reclaim(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
1830
					alloc_flags, preferred_zone,
1831
					migratetype, &did_some_progress);
1832 1833
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1834

1835
	/*
1836 1837
	 * If we failed to make any progress reclaiming, then we are
	 * running out of options and have to consider going OOM
1838
	 */
1839 1840
	if (!did_some_progress) {
		if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1841 1842
			if (oom_killer_disabled)
				goto nopage;
1843 1844
			page = __alloc_pages_may_oom(gfp_mask, order,
					zonelist, high_zoneidx,
1845 1846
					nodemask, preferred_zone,
					migratetype);
1847 1848
			if (page)
				goto got_pg;
L
Linus Torvalds 已提交
1849

1850
			/*
1851 1852 1853 1854
			 * The OOM killer does not trigger for high-order
			 * ~__GFP_NOFAIL allocations so if no progress is being
			 * made, there are no other options and retrying is
			 * unlikely to help.
1855
			 */
1856 1857
			if (order > PAGE_ALLOC_COSTLY_ORDER &&
						!(gfp_mask & __GFP_NOFAIL))
1858
				goto nopage;
1859

1860 1861
			goto restart;
		}
L
Linus Torvalds 已提交
1862 1863
	}

1864
	/* Check if we should retry the allocation */
1865
	pages_reclaimed += did_some_progress;
1866 1867
	if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
		/* Wait for some write requests to complete then retry */
1868
		congestion_wait(BLK_RW_ASYNC, HZ/50);
L
Linus Torvalds 已提交
1869 1870 1871 1872 1873 1874 1875 1876 1877
		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
1878
		show_mem();
L
Linus Torvalds 已提交
1879
	}
1880
	return page;
L
Linus Torvalds 已提交
1881
got_pg:
1882 1883
	if (kmemcheck_enabled)
		kmemcheck_pagealloc_alloc(page, order, gfp_mask);
L
Linus Torvalds 已提交
1884
	return page;
1885

L
Linus Torvalds 已提交
1886
}
1887 1888 1889 1890 1891 1892 1893 1894 1895

/*
 * This is the 'heart' of the zoned buddy allocator.
 */
struct page *
__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
			struct zonelist *zonelist, nodemask_t *nodemask)
{
	enum zone_type high_zoneidx = gfp_zone(gfp_mask);
1896
	struct zone *preferred_zone;
1897
	struct page *page;
1898
	int migratetype = allocflags_to_migratetype(gfp_mask);
1899

1900 1901
	gfp_mask &= gfp_allowed_mask;

1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916
	lockdep_trace_alloc(gfp_mask);

	might_sleep_if(gfp_mask & __GFP_WAIT);

	if (should_fail_alloc_page(gfp_mask, order))
		return NULL;

	/*
	 * Check the zones suitable for the gfp_mask contain at least one
	 * valid zone. It's possible to have an empty zonelist as a result
	 * of GFP_THISNODE and a memoryless node
	 */
	if (unlikely(!zonelist->_zonerefs->zone))
		return NULL;

1917 1918 1919 1920 1921 1922
	/* The preferred zone is used for statistics later */
	first_zones_zonelist(zonelist, high_zoneidx, nodemask, &preferred_zone);
	if (!preferred_zone)
		return NULL;

	/* First allocation attempt */
1923
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
1924
			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
1925
			preferred_zone, migratetype);
1926 1927
	if (unlikely(!page))
		page = __alloc_pages_slowpath(gfp_mask, order,
1928
				zonelist, high_zoneidx, nodemask,
1929
				preferred_zone, migratetype);
1930

1931
	trace_mm_page_alloc(page, order, gfp_mask, migratetype);
1932
	return page;
L
Linus Torvalds 已提交
1933
}
1934
EXPORT_SYMBOL(__alloc_pages_nodemask);
L
Linus Torvalds 已提交
1935 1936 1937 1938

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
1939
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
1940
{
1941 1942 1943 1944 1945 1946 1947 1948
	struct page *page;

	/*
	 * __get_free_pages() returns a 32-bit address, which cannot represent
	 * a highmem page
	 */
	VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);

L
Linus Torvalds 已提交
1949 1950 1951 1952 1953 1954 1955
	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
1956
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
1957
{
1958
	return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
L
Linus Torvalds 已提交
1959 1960 1961 1962 1963 1964 1965
}
EXPORT_SYMBOL(get_zeroed_page);

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

1966 1967
	while (--i >= 0) {
		trace_mm_pagevec_free(pvec->pages[i], pvec->cold);
L
Linus Torvalds 已提交
1968
		free_hot_cold_page(pvec->pages[i], pvec->cold);
1969
	}
L
Linus Torvalds 已提交
1970 1971
}

H
Harvey Harrison 已提交
1972
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
1973
{
N
Nick Piggin 已提交
1974
	if (put_page_testzero(page)) {
1975
		trace_mm_page_free_direct(page, order);
L
Linus Torvalds 已提交
1976 1977 1978 1979 1980 1981 1982 1983 1984
		if (order == 0)
			free_hot_page(page);
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
1985
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
1986 1987
{
	if (addr != 0) {
N
Nick Piggin 已提交
1988
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
1989 1990 1991 1992 1993 1994
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
/**
 * 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);

K
Kevin Cernekee 已提交
2018
		split_page(virt_to_page((void *)addr), order);
2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047
		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
2048 2049
static unsigned int nr_free_zone_pages(int offset)
{
2050
	struct zoneref *z;
2051 2052
	struct zone *zone;

2053
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
2054 2055
	unsigned int sum = 0;

2056
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
2057

2058
	for_each_zone_zonelist(zone, z, zonelist, offset) {
2059
		unsigned long size = zone->present_pages;
2060
		unsigned long high = high_wmark_pages(zone);
2061 2062
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
2063 2064 2065 2066 2067 2068 2069 2070 2071 2072
	}

	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
2073
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
2074
}
2075
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
2076 2077 2078 2079 2080 2081

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
2082
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
2083
}
2084 2085

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
2086
{
2087
	if (NUMA_BUILD)
2088
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
2089 2090 2091 2092 2093 2094
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
2095
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109
	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;
2110
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
2111
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2112
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2113 2114
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
2115 2116 2117 2118
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131
	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)
{
2132
	int cpu;
L
Linus Torvalds 已提交
2133 2134
	struct zone *zone;

2135
	for_each_populated_zone(zone) {
2136 2137
		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
2138

2139
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
2140 2141
			struct per_cpu_pageset *pageset;

2142
			pageset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
2143

2144 2145 2146
			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
2147 2148 2149
		}
	}

K
KOSAKI Motohiro 已提交
2150 2151
	printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
		" active_file:%lu inactive_file:%lu isolated_file:%lu\n"
L
Lee Schermerhorn 已提交
2152
		" unevictable:%lu"
2153
		" dirty:%lu writeback:%lu unstable:%lu buffer:%lu\n"
2154
		" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2155
		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2156 2157
		global_page_state(NR_ACTIVE_ANON),
		global_page_state(NR_INACTIVE_ANON),
K
KOSAKI Motohiro 已提交
2158 2159
		global_page_state(NR_ISOLATED_ANON),
		global_page_state(NR_ACTIVE_FILE),
2160
		global_page_state(NR_INACTIVE_FILE),
K
KOSAKI Motohiro 已提交
2161
		global_page_state(NR_ISOLATED_FILE),
L
Lee Schermerhorn 已提交
2162
		global_page_state(NR_UNEVICTABLE),
2163
		global_page_state(NR_FILE_DIRTY),
2164
		global_page_state(NR_WRITEBACK),
2165
		global_page_state(NR_UNSTABLE_NFS),
2166
		nr_blockdev_pages(),
2167
		global_page_state(NR_FREE_PAGES),
2168 2169
		global_page_state(NR_SLAB_RECLAIMABLE),
		global_page_state(NR_SLAB_UNRECLAIMABLE),
2170
		global_page_state(NR_FILE_MAPPED),
2171
		global_page_state(NR_SHMEM),
2172 2173
		global_page_state(NR_PAGETABLE),
		global_page_state(NR_BOUNCE));
L
Linus Torvalds 已提交
2174

2175
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
2176 2177 2178 2179 2180 2181 2182 2183
		int i;

		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
2184 2185 2186 2187
			" active_anon:%lukB"
			" inactive_anon:%lukB"
			" active_file:%lukB"
			" inactive_file:%lukB"
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			" unevictable:%lukB"
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2189 2190
			" isolated(anon):%lukB"
			" isolated(file):%lukB"
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			" present:%lukB"
2192 2193 2194 2195
			" mlocked:%lukB"
			" dirty:%lukB"
			" writeback:%lukB"
			" mapped:%lukB"
2196
			" shmem:%lukB"
2197 2198
			" slab_reclaimable:%lukB"
			" slab_unreclaimable:%lukB"
2199
			" kernel_stack:%lukB"
2200 2201 2202 2203
			" pagetables:%lukB"
			" unstable:%lukB"
			" bounce:%lukB"
			" writeback_tmp:%lukB"
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			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
2208
			K(zone_page_state(zone, NR_FREE_PAGES)),
2209 2210 2211
			K(min_wmark_pages(zone)),
			K(low_wmark_pages(zone)),
			K(high_wmark_pages(zone)),
2212 2213 2214 2215
			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)),
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			K(zone_page_state(zone, NR_UNEVICTABLE)),
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			K(zone_page_state(zone, NR_ISOLATED_ANON)),
			K(zone_page_state(zone, NR_ISOLATED_FILE)),
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			K(zone->present_pages),
2220 2221 2222 2223
			K(zone_page_state(zone, NR_MLOCK)),
			K(zone_page_state(zone, NR_FILE_DIRTY)),
			K(zone_page_state(zone, NR_WRITEBACK)),
			K(zone_page_state(zone, NR_FILE_MAPPED)),
2224
			K(zone_page_state(zone, NR_SHMEM)),
2225 2226
			K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
			K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
2227 2228
			zone_page_state(zone, NR_KERNEL_STACK) *
				THREAD_SIZE / 1024,
2229 2230 2231 2232
			K(zone_page_state(zone, NR_PAGETABLE)),
			K(zone_page_state(zone, NR_UNSTABLE_NFS)),
			K(zone_page_state(zone, NR_BOUNCE)),
			K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
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			zone->pages_scanned,
2234
			(zone_is_all_unreclaimable(zone) ? "yes" : "no")
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			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

2242
	for_each_populated_zone(zone) {
2243
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
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		show_node(zone);
		printk("%s: ", zone->name);

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
2250 2251
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
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		}
		spin_unlock_irqrestore(&zone->lock, flags);
2254 2255
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
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		printk("= %lukB\n", K(total));
	}

2259 2260
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

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	show_swap_cache_info();
}

2264 2265 2266 2267 2268 2269
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
{
	zoneref->zone = zone;
	zoneref->zone_idx = zone_idx(zone);
}

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/*
 * Builds allocation fallback zone lists.
2272 2273
 *
 * Add all populated zones of a node to the zonelist.
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 */
2275 2276
static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
				int nr_zones, enum zone_type zone_type)
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{
2278 2279
	struct zone *zone;

2280
	BUG_ON(zone_type >= MAX_NR_ZONES);
2281
	zone_type++;
2282 2283

	do {
2284
		zone_type--;
2285
		zone = pgdat->node_zones + zone_type;
2286
		if (populated_zone(zone)) {
2287 2288
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
2289
			check_highest_zone(zone_type);
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		}
2291

2292
	} while (zone_type);
2293
	return nr_zones;
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}

2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316

/*
 *  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"};


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#ifdef CONFIG_NUMA
2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388
/* 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;
}


2389
#define MAX_NODE_LOAD (nr_online_nodes)
2390 2391
static int node_load[MAX_NUMNODES];

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/**
2393
 * find_next_best_node - find the next node that should appear in a given node's fallback list
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2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405
 * @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.
 */
2406
static int find_next_best_node(int node, nodemask_t *used_node_mask)
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{
2408
	int n, val;
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	int min_val = INT_MAX;
	int best_node = -1;
2411
	const struct cpumask *tmp = cpumask_of_node(0);
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2413 2414 2415 2416 2417
	/* Use the local node if we haven't already */
	if (!node_isset(node, *used_node_mask)) {
		node_set(node, *used_node_mask);
		return node;
	}
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2418

2419
	for_each_node_state(n, N_HIGH_MEMORY) {
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2420 2421 2422 2423 2424 2425 2426 2427

		/* 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);

2428 2429 2430
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

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		/* Give preference to headless and unused nodes */
2432 2433
		tmp = cpumask_of_node(n);
		if (!cpumask_empty(tmp))
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2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451
			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;
}

2452 2453 2454 2455 2456 2457 2458

/*
 * Build zonelists ordered by node and zones within node.
 * This results in maximum locality--normal zone overflows into local
 * DMA zone, if any--but risks exhausting DMA zone.
 */
static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
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{
2460
	int j;
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	struct zonelist *zonelist;
2462

2463
	zonelist = &pgdat->node_zonelists[0];
2464
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2465 2466 2467
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
2468 2469
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2470 2471
}

2472 2473 2474 2475 2476 2477 2478 2479
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

2480 2481
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2482 2483
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2484 2485
}

2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500
/*
 * 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;

2501 2502 2503 2504 2505 2506 2507
	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)) {
2508 2509
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
2510
				check_highest_zone(zone_type);
2511 2512 2513
			}
		}
	}
2514 2515
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550
}

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.
         */
2551 2552
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583
	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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	nodemask_t used_mask;
2585 2586 2587
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
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2588 2589

	/* initialize zonelists */
2590
	for (i = 0; i < MAX_ZONELISTS; i++) {
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2591
		zonelist = pgdat->node_zonelists + i;
2592 2593
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
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2594 2595 2596 2597
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
2598
	load = nr_online_nodes;
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2599 2600
	prev_node = local_node;
	nodes_clear(used_mask);
2601 2602 2603 2604

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

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2605
	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2606 2607 2608 2609 2610 2611 2612 2613 2614
		int distance = node_distance(local_node, node);

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

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2615 2616 2617 2618 2619
		/*
		 * 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.
		 */
2620
		if (distance != node_distance(local_node, prev_node))
2621 2622
			node_load[node] = load;

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2623 2624
		prev_node = node;
		load--;
2625 2626 2627 2628 2629
		if (order == ZONELIST_ORDER_NODE)
			build_zonelists_in_node_order(pgdat, node);
		else
			node_order[j++] = node;	/* remember order */
	}
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2631 2632 2633
	if (order == ZONELIST_ORDER_ZONE) {
		/* calculate node order -- i.e., DMA last! */
		build_zonelists_in_zone_order(pgdat, j);
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	}
2635 2636

	build_thisnode_zonelists(pgdat);
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2637 2638
}

2639
/* Construct the zonelist performance cache - see further mmzone.h */
2640
static void build_zonelist_cache(pg_data_t *pgdat)
2641
{
2642 2643
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
2644
	struct zoneref *z;
2645

2646 2647 2648
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2649 2650
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2651 2652
}

2653

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2654 2655
#else	/* CONFIG_NUMA */

2656 2657 2658 2659 2660 2661
static void set_zonelist_order(void)
{
	current_zonelist_order = ZONELIST_ORDER_ZONE;
}

static void build_zonelists(pg_data_t *pgdat)
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{
2663
	int node, local_node;
2664 2665
	enum zone_type j;
	struct zonelist *zonelist;
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2666 2667 2668

	local_node = pgdat->node_id;

2669 2670
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
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2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684
	/*
	 * 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);
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	}
2686 2687 2688 2689 2690 2691 2692
	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);
	}

2693 2694
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
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2695 2696
}

2697
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2698
static void build_zonelist_cache(pg_data_t *pgdat)
2699
{
2700
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
2701 2702
}

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#endif	/* CONFIG_NUMA */

2705
/* return values int ....just for stop_machine() */
2706
static int __build_all_zonelists(void *dummy)
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Linus Torvalds 已提交
2707
{
2708
	int nid;
2709

2710 2711 2712
#ifdef CONFIG_NUMA
	memset(node_load, 0, sizeof(node_load));
#endif
2713
	for_each_online_node(nid) {
2714 2715 2716 2717
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
2718
	}
2719 2720 2721
	return 0;
}

2722
void build_all_zonelists(void)
2723
{
2724 2725
	set_zonelist_order();

2726
	if (system_state == SYSTEM_BOOTING) {
2727
		__build_all_zonelists(NULL);
2728
		mminit_verify_zonelist();
2729 2730
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
2731
		/* we have to stop all cpus to guarantee there is no user
2732
		   of zonelist */
2733
		stop_machine(__build_all_zonelists, NULL, NULL);
2734 2735
		/* cpuset refresh routine should be here */
	}
2736
	vm_total_pages = nr_free_pagecache_pages();
2737 2738 2739 2740 2741 2742 2743
	/*
	 * 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
	 */
2744
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2745 2746 2747 2748 2749 2750
		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",
2751
			nr_online_nodes,
2752
			zonelist_order_name[current_zonelist_order],
2753
			page_group_by_mobility_disabled ? "off" : "on",
2754 2755 2756 2757
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
L
Linus Torvalds 已提交
2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772
}

/*
 * 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

2773
#ifndef CONFIG_MEMORY_HOTPLUG
2774
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791
{
	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);
}
2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814
#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
2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827

/*
 * 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))

2828
/*
2829
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2830 2831
 * of blocks reserved is based on min_wmark_pages(zone). The memory within
 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
2832 2833 2834 2835 2836 2837 2838
 * 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;
2839 2840
	unsigned long block_migratetype;
	int reserve;
2841 2842 2843 2844

	/* 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;
2845
	reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
2846
							pageblock_order;
2847

2848 2849 2850 2851 2852 2853 2854 2855 2856
	/*
	 * Reserve blocks are generally in place to help high-order atomic
	 * allocations that are short-lived. A min_free_kbytes value that
	 * would result in more than 2 reserve blocks for atomic allocations
	 * is assumed to be in place to help anti-fragmentation for the
	 * future allocation of hugepages at runtime.
	 */
	reserve = min(2, reserve);

2857
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2858 2859 2860 2861
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

2862 2863 2864 2865
		/* Watch out for overlapping nodes */
		if (page_to_nid(page) != zone_to_nid(zone))
			continue;

2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895
		/* 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
2896

L
Linus Torvalds 已提交
2897 2898 2899 2900 2901
/*
 * 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.
 */
2902
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
2903
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
2904 2905
{
	struct page *page;
A
Andy Whitcroft 已提交
2906 2907
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
2908
	struct zone *z;
L
Linus Torvalds 已提交
2909

2910 2911 2912
	if (highest_memmap_pfn < end_pfn - 1)
		highest_memmap_pfn = end_pfn - 1;

2913
	z = &NODE_DATA(nid)->node_zones[zone];
2914
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925
		/*
		 * 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
2926 2927
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
2928
		mminit_verify_page_links(page, zone, nid, pfn);
2929
		init_page_count(page);
L
Linus Torvalds 已提交
2930 2931
		reset_page_mapcount(page);
		SetPageReserved(page);
2932 2933 2934 2935 2936
		/*
		 * 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
2937 2938 2939
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
2940 2941 2942 2943 2944
		 *
		 * 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.
2945
		 */
2946 2947 2948
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
2949
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2950

L
Linus Torvalds 已提交
2951 2952 2953 2954
		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))
2955
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
2956 2957 2958 2959
#endif
	}
}

2960
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
2961
{
2962 2963 2964
	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
2965 2966 2967 2968 2969 2970
		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
2971
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
2972 2973
#endif

2974
static int zone_batchsize(struct zone *zone)
2975
{
2976
#ifdef CONFIG_MMU
2977 2978 2979 2980
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
2981
	 * size of the zone.  But no more than 1/2 of a meg.
2982 2983 2984 2985
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
2986 2987
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
2988 2989 2990 2991 2992
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
2993 2994 2995
	 * 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.
2996
	 *
2997 2998 2999 3000
	 * 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.
3001
	 */
3002
	batch = rounddown_pow_of_two(batch + batch/2) - 1;
3003

3004
	return batch;
3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021

#else
	/* The deferral and batching of frees should be suppressed under NOMMU
	 * conditions.
	 *
	 * The problem is that NOMMU needs to be able to allocate large chunks
	 * of contiguous memory as there's no hardware page translation to
	 * assemble apparent contiguous memory from discontiguous pages.
	 *
	 * Queueing large contiguous runs of pages for batching, however,
	 * causes the pages to actually be freed in smaller chunks.  As there
	 * can be a significant delay between the individual batches being
	 * recycled, this leads to the once large chunks of space being
	 * fragmented and becoming unavailable for high-order allocations.
	 */
	return 0;
#endif
3022 3023
}

A
Adrian Bunk 已提交
3024
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3025 3026 3027
{
	struct per_cpu_pages *pcp;

3028 3029
	memset(p, 0, sizeof(*p));

3030
	pcp = &p->pcp;
3031 3032 3033 3034 3035 3036
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
	INIT_LIST_HEAD(&pcp->list);
}

3037 3038 3039 3040 3041 3042 3043 3044 3045 3046
/*
 * 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;

3047
	pcp = &p->pcp;
3048 3049 3050 3051 3052 3053 3054
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}


3055 3056
#ifdef CONFIG_NUMA
/*
3057 3058 3059 3060 3061 3062 3063
 * 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.
3064 3065 3066 3067 3068 3069 3070 3071
 *
 * 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.
3072
 */
3073
static struct per_cpu_pageset boot_pageset[NR_CPUS];
3074 3075 3076

/*
 * Dynamically allocate memory for the
3077 3078
 * per cpu pageset array in struct zone.
 */
3079
static int __cpuinit process_zones(int cpu)
3080 3081
{
	struct zone *zone, *dzone;
3082 3083 3084
	int node = cpu_to_node(cpu);

	node_set_state(node, N_CPU);	/* this node has a cpu */
3085

3086
	for_each_populated_zone(zone) {
N
Nick Piggin 已提交
3087
		zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
3088
					 GFP_KERNEL, node);
N
Nick Piggin 已提交
3089
		if (!zone_pcp(zone, cpu))
3090 3091
			goto bad;

N
Nick Piggin 已提交
3092
		setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
3093 3094 3095 3096

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(zone_pcp(zone, cpu),
			 	(zone->present_pages / percpu_pagelist_fraction));
3097 3098 3099 3100 3101
	}

	return 0;
bad:
	for_each_zone(dzone) {
3102 3103
		if (!populated_zone(dzone))
			continue;
3104 3105
		if (dzone == zone)
			break;
N
Nick Piggin 已提交
3106
		kfree(zone_pcp(dzone, cpu));
3107
		zone_pcp(dzone, cpu) = &boot_pageset[cpu];
3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118
	}
	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);

3119 3120 3121
		/* Free per_cpu_pageset if it is slab allocated */
		if (pset != &boot_pageset[cpu])
			kfree(pset);
3122
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
3123 3124 3125
	}
}

3126
static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
3127 3128 3129 3130 3131 3132 3133
		unsigned long action,
		void *hcpu)
{
	int cpu = (long)hcpu;
	int ret = NOTIFY_OK;

	switch (action) {
3134
	case CPU_UP_PREPARE:
3135
	case CPU_UP_PREPARE_FROZEN:
3136 3137 3138 3139
		if (process_zones(cpu))
			ret = NOTIFY_BAD;
		break;
	case CPU_UP_CANCELED:
3140
	case CPU_UP_CANCELED_FROZEN:
3141
	case CPU_DEAD:
3142
	case CPU_DEAD_FROZEN:
3143 3144 3145 3146
		free_zone_pagesets(cpu);
		break;
	default:
		break;
3147 3148 3149 3150
	}
	return ret;
}

3151
static struct notifier_block __cpuinitdata pageset_notifier =
3152 3153
	{ &pageset_cpuup_callback, NULL, 0 };

3154
void __init setup_per_cpu_pageset(void)
3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168
{
	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
3169
static noinline __init_refok
3170
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3171 3172 3173
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
3174
	size_t alloc_size;
3175 3176 3177 3178 3179

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
3180 3181 3182 3183
	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);
3184 3185 3186
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

3187
	if (!slab_is_available()) {
3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200
		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.
		 */
3201
		zone->wait_table = vmalloc(alloc_size);
3202 3203 3204
	}
	if (!zone->wait_table)
		return -ENOMEM;
3205

3206
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3207
		init_waitqueue_head(zone->wait_table + i);
3208 3209

	return 0;
3210 3211
}

3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237
static int __zone_pcp_update(void *data)
{
	struct zone *zone = data;
	int cpu;
	unsigned long batch = zone_batchsize(zone), flags;

	for (cpu = 0; cpu < NR_CPUS; cpu++) {
		struct per_cpu_pageset *pset;
		struct per_cpu_pages *pcp;

		pset = zone_pcp(zone, cpu);
		pcp = &pset->pcp;

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

void zone_pcp_update(struct zone *zone)
{
	stop_machine(__zone_pcp_update, zone, NULL);
}

3238
static __meminit void zone_pcp_init(struct zone *zone)
3239 3240 3241 3242 3243 3244 3245
{
	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
3246
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
3247 3248 3249 3250 3251
		setup_pageset(&boot_pageset[cpu],0);
#else
		setup_pageset(zone_pcp(zone,cpu), batch);
#endif
	}
A
Anton Blanchard 已提交
3252 3253 3254
	if (zone->present_pages)
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%lu\n",
			zone->name, zone->present_pages, batch);
3255 3256
}

3257 3258
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
3259 3260
					unsigned long size,
					enum memmap_context context)
3261 3262
{
	struct pglist_data *pgdat = zone->zone_pgdat;
3263 3264 3265 3266
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
3267 3268 3269 3270
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

3271 3272 3273 3274 3275 3276
	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));

3277
	zone_init_free_lists(zone);
3278 3279

	return 0;
3280 3281
}

3282 3283 3284 3285 3286
#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
 */
3287
static int __meminit first_active_region_index_in_nid(int nid)
3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299
{
	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
3300
 * Note: nid == MAX_NUMNODES returns next region regardless of node
3301
 */
3302
static int __meminit next_active_region_index_in_nid(int index, int nid)
3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317
{
	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
 */
3318
int __meminit __early_pfn_to_nid(unsigned long pfn)
3319 3320 3321 3322 3323 3324 3325 3326 3327 3328
{
	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;
	}
3329 3330
	/* This is a memory hole */
	return -1;
3331 3332 3333
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

3334 3335
int __meminit early_pfn_to_nid(unsigned long pfn)
{
3336 3337 3338 3339 3340 3341 3342
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0)
		return nid;
	/* just returns 0 */
	return 0;
3343 3344
}

3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355
#ifdef CONFIG_NODES_SPAN_OTHER_NODES
bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
{
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0 && nid != node)
		return false;
	return true;
}
#endif
3356

3357 3358 3359 3360 3361 3362 3363
/* 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
3364 3365
 * @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
3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392
 *
 * 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);
	}
}

3393 3394 3395
void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
{
	int i;
3396
	int ret;
3397

3398 3399 3400 3401 3402 3403
	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;
	}
3404
}
3405 3406
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3407
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3408 3409 3410
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
3411
 * function may be used instead of calling memory_present() manually.
3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424
 */
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);
}

/**
 * get_pfn_range_for_nid - Return the start and end page frames for a node
3425 3426 3427
 * @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.
3428 3429 3430 3431
 *
 * 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
3432
 * PFNs will be 0.
3433
 */
3434
void __meminit get_pfn_range_for_nid(unsigned int nid,
3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445
			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);
	}

3446
	if (*start_pfn == -1UL)
3447 3448 3449
		*start_pfn = 0;
}

M
Mel Gorman 已提交
3450 3451 3452 3453 3454
/*
 * 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
3455
static void __init find_usable_zone_for_movable(void)
M
Mel Gorman 已提交
3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480
{
	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
3481
static void __meminit adjust_zone_range_for_zone_movable(int nid,
M
Mel Gorman 已提交
3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506
					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;
	}
}

3507 3508 3509 3510
/*
 * 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
3511
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3512 3513 3514 3515 3516 3517 3518 3519 3520 3521
					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
3522 3523 3524
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539

	/* 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,
3540
 * then all holes in the requested range will be accounted for.
3541
 */
A
Adrian Bunk 已提交
3542
static unsigned long __meminit __absent_pages_in_range(int nid,
3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554
				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;

3555 3556
	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);

3557 3558
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
3559
		hole_pages = prev_end_pfn - range_start_pfn;
3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579

	/* 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;
	}

3580 3581
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
3582
		hole_pages += range_end_pfn -
3583 3584
				max(range_start_pfn, prev_end_pfn);

3585 3586 3587 3588 3589 3590 3591 3592
	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
 *
3593
 * It returns the number of pages frames in memory holes within a range.
3594 3595 3596 3597 3598 3599 3600 3601
 */
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
3602
static unsigned long __meminit zone_absent_pages_in_node(int nid,
3603 3604 3605
					unsigned long zone_type,
					unsigned long *ignored)
{
3606 3607 3608 3609 3610 3611 3612 3613 3614
	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
3615 3616 3617
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
3618
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3619
}
3620

3621
#else
P
Paul Mundt 已提交
3622
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3623 3624 3625 3626 3627 3628
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
3629
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3630 3631 3632 3633 3634 3635 3636 3637
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
3638

3639 3640
#endif

3641
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661
		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);
}

3662 3663 3664
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
3665 3666
 * 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
3667 3668 3669 3670 3671 3672 3673
 * 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;

3674 3675
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686
	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;
3687
	if (usemapsize)
3688 3689 3690 3691 3692 3693 3694
		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 */

3695
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3696 3697 3698 3699 3700 3701 3702 3703 3704 3705

/* 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;
}

3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720
/* 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 */

3721 3722 3723 3724 3725 3726 3727 3728 3729 3730
/*
 * 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;
}
3731 3732 3733 3734
#define set_pageblock_order(x)	do {} while (0)

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
3735 3736 3737 3738 3739 3740
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
3741
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3742 3743
		unsigned long *zones_size, unsigned long *zholes_size)
{
3744
	enum zone_type j;
3745
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
3746
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
3747
	int ret;
L
Linus Torvalds 已提交
3748

3749
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
3750 3751 3752
	pgdat->nr_zones = 0;
	init_waitqueue_head(&pgdat->kswapd_wait);
	pgdat->kswapd_max_order = 0;
3753
	pgdat_page_cgroup_init(pgdat);
L
Linus Torvalds 已提交
3754 3755 3756
	
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
3757
		unsigned long size, realsize, memmap_pages;
3758
		enum lru_list l;
L
Linus Torvalds 已提交
3759

3760 3761 3762
		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
3763

3764 3765 3766 3767 3768
		/*
		 * 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
		 */
3769 3770
		memmap_pages =
			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
3771 3772
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
3773 3774 3775 3776
			if (memmap_pages)
				printk(KERN_DEBUG
				       "  %s zone: %lu pages used for memmap\n",
				       zone_names[j], memmap_pages);
3777 3778 3779 3780 3781
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

3782 3783
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
3784
			realsize -= dma_reserve;
Y
Yinghai Lu 已提交
3785
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
3786
					zone_names[0], dma_reserve);
3787 3788
		}

3789
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
3790 3791 3792 3793 3794
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
3795
#ifdef CONFIG_NUMA
3796
		zone->node = nid;
3797
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3798
						/ 100;
3799
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3800
#endif
L
Linus Torvalds 已提交
3801 3802 3803
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
3804
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
3805 3806
		zone->zone_pgdat = pgdat;

3807
		zone->prev_priority = DEF_PRIORITY;
L
Linus Torvalds 已提交
3808

3809
		zone_pcp_init(zone);
3810 3811
		for_each_lru(l) {
			INIT_LIST_HEAD(&zone->lru[l].list);
3812
			zone->lru[l].nr_saved_scan = 0;
3813
		}
3814 3815 3816 3817
		zone->reclaim_stat.recent_rotated[0] = 0;
		zone->reclaim_stat.recent_rotated[1] = 0;
		zone->reclaim_stat.recent_scanned[0] = 0;
		zone->reclaim_stat.recent_scanned[1] = 0;
3818
		zap_zone_vm_stats(zone);
3819
		zone->flags = 0;
L
Linus Torvalds 已提交
3820 3821 3822
		if (!size)
			continue;

3823
		set_pageblock_order(pageblock_default_order());
3824
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
3825 3826
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
3827
		BUG_ON(ret);
3828
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
3829 3830 3831 3832
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
3833
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
3834 3835 3836 3837 3838
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
3839
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
3840 3841
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
3842
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
3843 3844
		struct page *map;

3845 3846 3847 3848 3849 3850 3851 3852 3853
		/*
		 * 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);
3854 3855 3856
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
3857
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
3858
	}
3859
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
3860 3861 3862
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
3863
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
3864
		mem_map = NODE_DATA(0)->node_mem_map;
3865 3866
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3867
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3868 3869
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
3870
#endif
A
Andy Whitcroft 已提交
3871
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
3872 3873
}

3874 3875
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
3876
{
3877 3878
	pg_data_t *pgdat = NODE_DATA(nid);

L
Linus Torvalds 已提交
3879 3880
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
3881
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
3882 3883

	alloc_node_mem_map(pgdat);
3884 3885 3886 3887 3888
#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
3889 3890 3891 3892

	free_area_init_core(pgdat, zones_size, zholes_size);
}

3893
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
M
Miklos Szeredi 已提交
3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913

#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

3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930
/**
 * 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;

3931 3932 3933 3934 3935
	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);
3936

3937 3938
	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);

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
	/* 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;
}

/**
3978
 * remove_active_range - Shrink an existing registered range of PFNs
3979
 * @nid: The node id the range is on that should be shrunk
3980 3981
 * @start_pfn: The new PFN of the range
 * @end_pfn: The new PFN of the range
3982 3983
 *
 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3984 3985 3986
 * 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.
3987
 */
3988 3989
void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
				unsigned long end_pfn)
3990
{
3991 3992
	int i, j;
	int removed = 0;
3993

3994 3995 3996
	printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
			  nid, start_pfn, end_pfn);

3997
	/* Find the old active region end and shrink */
3998
	for_each_active_range_index_in_nid(i, nid) {
3999 4000
		if (early_node_map[i].start_pfn >= start_pfn &&
		    early_node_map[i].end_pfn <= end_pfn) {
4001
			/* clear it */
4002
			early_node_map[i].start_pfn = 0;
4003 4004 4005 4006
			early_node_map[i].end_pfn = 0;
			removed = 1;
			continue;
		}
4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018
		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;
4019
			continue;
4020
		}
4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039
	}

	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--;
	}
4040 4041 4042 4043
}

/**
 * remove_all_active_ranges - Remove all currently registered regions
4044
 *
4045 4046 4047 4048
 * 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.
 */
4049
void __init remove_all_active_ranges(void)
4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077
{
	memset(early_node_map, 0, sizeof(early_node_map));
	nr_nodemap_entries = 0;
}

/* 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);
}

4078
/* Find the lowest pfn for a node */
A
Adrian Bunk 已提交
4079
static unsigned long __init find_min_pfn_for_node(int nid)
4080 4081
{
	int i;
4082
	unsigned long min_pfn = ULONG_MAX;
4083

4084 4085
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
4086
		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
4087

4088 4089
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
4090
			"Could not find start_pfn for node %d\n", nid);
4091 4092 4093 4094
		return 0;
	}

	return min_pfn;
4095 4096 4097 4098 4099 4100
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
4101
 * add_active_range().
4102 4103 4104 4105 4106 4107
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

4108 4109 4110 4111 4112
/*
 * 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
4113
static unsigned long __init early_calculate_totalpages(void)
4114 4115 4116 4117
{
	int i;
	unsigned long totalpages = 0;

4118 4119
	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long pages = early_node_map[i].end_pfn -
4120
						early_node_map[i].start_pfn;
4121 4122 4123 4124 4125
		totalpages += pages;
		if (pages)
			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
	}
  	return totalpages;
4126 4127
}

M
Mel Gorman 已提交
4128 4129 4130 4131 4132 4133
/*
 * 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
4134
static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
M
Mel Gorman 已提交
4135 4136 4137 4138
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
4139 4140
	/* save the state before borrow the nodemask */
	nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4141 4142
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
4143

4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165
	/*
	 * 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
4166 4167
	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
	if (!required_kernelcore)
4168
		goto out;
M
Mel Gorman 已提交
4169 4170 4171 4172 4173 4174 4175 4176

	/* 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;
4177
	for_each_node_state(nid, N_HIGH_MEMORY) {
M
Mel Gorman 已提交
4178 4179 4180 4181 4182 4183 4184 4185 4186 4187 4188 4189 4190 4191 4192 4193 4194 4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266
		/*
		 * 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);
4267 4268 4269 4270

out:
	/* restore the node_state */
	node_states[N_HIGH_MEMORY] = saved_node_state;
M
Mel Gorman 已提交
4271 4272
}

4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286
/* 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
}

4287 4288
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
4289
 * @max_zone_pfn: an array of max PFNs for each zone
4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302
 *
 * 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;
4303
	int i;
4304

4305 4306 4307
	/* Sort early_node_map as initialisation assumes it is sorted */
	sort_node_map();

4308 4309 4310 4311 4312 4313 4314 4315
	/* 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
4316 4317
		if (i == ZONE_MOVABLE)
			continue;
4318 4319 4320 4321 4322
		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
4323 4324 4325 4326 4327 4328
	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);
4329 4330 4331

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
M
Mel Gorman 已提交
4332 4333 4334
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
4335
		printk("  %-8s %0#10lx -> %0#10lx\n",
4336 4337 4338
				zone_names[i],
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);
M
Mel Gorman 已提交
4339 4340 4341 4342 4343 4344 4345 4346
	}

	/* 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]);
	}
4347 4348 4349 4350

	/* 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++)
4351
		printk("  %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4352 4353 4354 4355
						early_node_map[i].start_pfn,
						early_node_map[i].end_pfn);

	/* Initialise every node */
4356
	mminit_verify_pageflags_layout();
4357
	setup_nr_node_ids();
4358 4359
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
4360
		free_area_init_node(nid, NULL,
4361
				find_min_pfn_for_node(nid), NULL);
4362 4363 4364 4365 4366

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
4367 4368
	}
}
M
Mel Gorman 已提交
4369

4370
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
4371 4372 4373 4374 4375 4376
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
4377
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
4378

4379
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
4380 4381 4382 4383
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
4384

4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402
/*
 * 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
4403
early_param("kernelcore", cmdline_parse_kernelcore);
4404
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
4405

4406 4407
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

4408
/**
4409 4410
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
4411 4412 4413 4414
 *
 * 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
4415 4416 4417
 * 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.
4418 4419 4420 4421 4422 4423
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

4424
#ifndef CONFIG_NEED_MULTIPLE_NODES
4425
struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] };
L
Linus Torvalds 已提交
4426
EXPORT_SYMBOL(contig_page_data);
4427
#endif
L
Linus Torvalds 已提交
4428 4429 4430

void __init free_area_init(unsigned long *zones_size)
{
4431
	free_area_init_node(0, zones_size,
L
Linus Torvalds 已提交
4432 4433 4434 4435 4436 4437 4438 4439
			__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;

4440
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4441 4442 4443 4444 4445 4446 4447 4448
		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.
		 */
4449
		vm_events_fold_cpu(cpu);
4450 4451 4452 4453 4454 4455 4456 4457

		/*
		 * 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.
		 */
4458
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
4459 4460 4461 4462 4463 4464 4465 4466 4467
	}
	return NOTIFY_OK;
}

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

4468 4469 4470 4471 4472 4473 4474 4475
/*
 * 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;
4476
	enum zone_type i, j;
4477 4478 4479 4480 4481 4482 4483 4484 4485 4486 4487 4488

	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];
			}

4489 4490
			/* we treat the high watermark as reserved pages. */
			max += high_wmark_pages(zone);
4491 4492 4493 4494 4495 4496 4497 4498 4499

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

L
Linus Torvalds 已提交
4500 4501 4502 4503 4504 4505 4506 4507 4508
/*
 * 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;
4509
	enum zone_type j, idx;
L
Linus Torvalds 已提交
4510

4511
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
4512 4513 4514 4515 4516 4517
		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;

4518 4519
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
4520 4521
				struct zone *lower_zone;

4522 4523
				idx--;

L
Linus Torvalds 已提交
4524 4525 4526 4527 4528 4529 4530 4531 4532 4533
				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;
			}
		}
	}
4534 4535 4536

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4537 4538
}

4539
/**
4540
 * setup_per_zone_wmarks - called when min_free_kbytes changes
4541
 * or when memory is hot-{added|removed}
4542
 *
4543 4544
 * Ensures that the watermark[min,low,high] values for each zone are set
 * correctly with respect to min_free_kbytes.
L
Linus Torvalds 已提交
4545
 */
4546
void setup_per_zone_wmarks(void)
L
Linus Torvalds 已提交
4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 4557 4558 4559
{
	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) {
4560 4561
		u64 tmp;

4562
		spin_lock_irqsave(&zone->lock, flags);
4563 4564
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
4565 4566
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
4567 4568 4569 4570
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
4571
			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
N
Nick Piggin 已提交
4572 4573
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
Linus Torvalds 已提交
4574 4575 4576 4577 4578 4579 4580 4581
			 */
			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;
4582
			zone->watermark[WMARK_MIN] = min_pages;
L
Linus Torvalds 已提交
4583
		} else {
N
Nick Piggin 已提交
4584 4585
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
4586 4587
			 * proportionate to the zone's size.
			 */
4588
			zone->watermark[WMARK_MIN] = tmp;
L
Linus Torvalds 已提交
4589 4590
		}

4591 4592
		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) + (tmp >> 2);
		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
4593
		setup_zone_migrate_reserve(zone);
4594
		spin_unlock_irqrestore(&zone->lock, flags);
L
Linus Torvalds 已提交
4595
	}
4596 4597 4598

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4599 4600
}

4601
/*
4602 4603 4604 4605 4606 4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 4621
 * 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
 */
4622
void calculate_zone_inactive_ratio(struct zone *zone)
4623
{
4624
	unsigned int gb, ratio;
4625

4626 4627 4628
	/* Zone size in gigabytes */
	gb = zone->present_pages >> (30 - PAGE_SHIFT);
	if (gb)
4629
		ratio = int_sqrt(10 * gb);
4630 4631
	else
		ratio = 1;
4632

4633 4634
	zone->inactive_ratio = ratio;
}
4635

4636 4637 4638 4639 4640 4641
static void __init setup_per_zone_inactive_ratio(void)
{
	struct zone *zone;

	for_each_zone(zone)
		calculate_zone_inactive_ratio(zone);
4642 4643
}

L
Linus Torvalds 已提交
4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655 4656 4657 4658 4659 4660 4661 4662 4663 4664 4665 4666 4667
/*
 * 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
 */
4668
static int __init init_per_zone_wmark_min(void)
L
Linus Torvalds 已提交
4669 4670 4671 4672 4673 4674 4675 4676 4677 4678
{
	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;
4679
	setup_per_zone_wmarks();
L
Linus Torvalds 已提交
4680
	setup_per_zone_lowmem_reserve();
4681
	setup_per_zone_inactive_ratio();
L
Linus Torvalds 已提交
4682 4683
	return 0;
}
4684
module_init(init_per_zone_wmark_min)
L
Linus Torvalds 已提交
4685 4686 4687 4688 4689 4690 4691 4692 4693 4694

/*
 * 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);
4695
	if (write)
4696
		setup_per_zone_wmarks();
L
Linus Torvalds 已提交
4697 4698 4699
	return 0;
}

4700 4701 4702 4703 4704 4705 4706 4707 4708 4709 4710 4711
#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)
4712
		zone->min_unmapped_pages = (zone->present_pages *
4713 4714 4715
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
4716 4717 4718 4719 4720 4721 4722 4723 4724 4725 4726 4727 4728 4729 4730 4731

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;
}
4732 4733
#endif

L
Linus Torvalds 已提交
4734 4735 4736 4737 4738 4739
/*
 * 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
4740
 * minimum watermarks. The lowmem reserve ratio can only make sense
L
Linus Torvalds 已提交
4741 4742 4743 4744 4745 4746 4747 4748 4749 4750
 * 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;
}

4751 4752 4753 4754 4755 4756 4757 4758 4759 4760 4761 4762 4763 4764 4765 4766
/*
 * 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;
4767
	for_each_populated_zone(zone) {
4768 4769 4770 4771 4772 4773 4774 4775 4776
		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;
}

4777
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
4778 4779 4780 4781 4782 4783 4784 4785 4786 4787 4788 4789 4790 4791 4792 4793 4794 4795 4796 4797 4798 4799 4800 4801 4802 4803 4804 4805 4806 4807 4808 4809 4810 4811

#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
4812
		numentries = nr_kernel_pages;
L
Linus Torvalds 已提交
4813 4814 4815 4816 4817 4818 4819 4820 4821
		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);
4822 4823

		/* Make sure we've got at least a 0-order allocation.. */
4824 4825 4826 4827 4828 4829 4830 4831
		if (unlikely(flags & HASH_SMALL)) {
			/* Makes no sense without HASH_EARLY */
			WARN_ON(!(flags & HASH_EARLY));
			if (!(numentries >> *_hash_shift)) {
				numentries = 1UL << *_hash_shift;
				BUG_ON(!numentries);
			}
		} else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
4832
			numentries = PAGE_SIZE / bucketsize;
L
Linus Torvalds 已提交
4833
	}
4834
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
4835 4836 4837 4838 4839 4840 4841 4842 4843 4844

	/* 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;

4845
	log2qty = ilog2(numentries);
L
Linus Torvalds 已提交
4846 4847 4848 4849

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
4850
			table = alloc_bootmem_nopanic(size);
L
Linus Torvalds 已提交
4851 4852 4853
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
4854 4855
			/*
			 * If bucketsize is not a power-of-two, we may free
4856 4857
			 * some pages at the end of hash table which
			 * alloc_pages_exact() automatically does
4858
			 */
4859
			if (get_order(size) < MAX_ORDER) {
4860
				table = alloc_pages_exact(size, GFP_ATOMIC);
4861 4862
				kmemleak_alloc(table, size, 1, GFP_ATOMIC);
			}
L
Linus Torvalds 已提交
4863 4864 4865 4866 4867 4868
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

4869
	printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
L
Linus Torvalds 已提交
4870 4871
	       tablename,
	       (1U << log2qty),
4872
	       ilog2(size) - PAGE_SHIFT,
L
Linus Torvalds 已提交
4873 4874 4875 4876 4877 4878 4879 4880 4881
	       size);

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

	return table;
}
4882

4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893 4894 4895 4896 4897
/* 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);
4898
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4899 4900
#else
	pfn = pfn - zone->zone_start_pfn;
4901
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4902 4903 4904 4905
#endif /* CONFIG_SPARSEMEM */
}

/**
4906
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4907 4908 4909 4910 4911 4912 4913 4914 4915 4916 4917 4918 4919 4920 4921 4922 4923 4924 4925 4926 4927 4928
 * @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;
4929

4930 4931 4932 4933
	return flags;
}

/**
4934
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
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 * @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);
4952 4953
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
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	for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
		if (flags & value)
			__set_bit(bitidx + start_bitidx, bitmap);
		else
			__clear_bit(bitidx + start_bitidx, bitmap);
}
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KAMEZAWA Hiroyuki 已提交
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/*
 * This is designed as sub function...plz see page_isolation.c also.
 * set/clear page block's type to be ISOLATE.
 * page allocater never alloc memory from ISOLATE block.
 */

int set_migratetype_isolate(struct page *page)
{
	struct zone *zone;
	unsigned long flags;
	int ret = -EBUSY;
4973
	int zone_idx;
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KAMEZAWA Hiroyuki 已提交
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	zone = page_zone(page);
4976
	zone_idx = zone_idx(zone);
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KAMEZAWA Hiroyuki 已提交
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	spin_lock_irqsave(&zone->lock, flags);
	/*
	 * In future, more migrate types will be able to be isolation target.
	 */
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	if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE &&
	    zone_idx != ZONE_MOVABLE)
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KAMEZAWA Hiroyuki 已提交
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		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)
4990
		drain_all_pages();
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	return ret;
}

void unset_migratetype_isolate(struct page *page)
{
	struct zone *zone;
	unsigned long flags;
	zone = page_zone(page);
	spin_lock_irqsave(&zone->lock, flags);
	if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
		goto out;
	set_pageblock_migratetype(page, MIGRATE_MOVABLE);
	move_freepages_block(zone, page, MIGRATE_MOVABLE);
out:
	spin_unlock_irqrestore(&zone->lock, flags);
}
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KAMEZAWA Hiroyuki 已提交
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#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