page_alloc.c 138.7 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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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;

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	/* Don't complain about poisoned pages */
	if (PageHWPoison(page)) {
		__ClearPageBuddy(page);
		return;
	}

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	/*
	 * 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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}

/*
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 * Frees a number of pages from the PCP lists
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 * 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_pcppages_bulk(struct zone *zone, int count,
					struct per_cpu_pages *pcp)
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{
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	int migratetype = 0;
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	int batch_free = 0;
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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);
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	while (count) {
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		struct page *page;
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		struct list_head *list;

		/*
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		 * Remove pages from lists in a round-robin fashion. A
		 * batch_free count is maintained that is incremented when an
		 * empty list is encountered.  This is so more pages are freed
		 * off fuller lists instead of spinning excessively around empty
		 * lists
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		 */
		do {
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			batch_free++;
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			if (++migratetype == MIGRATE_PCPTYPES)
				migratetype = 0;
			list = &pcp->lists[migratetype];
		} while (list_empty(list));
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Nick Piggin 已提交
557

558 559 560 561 562 563 564
		do {
			page = list_entry(list->prev, struct page, lru);
			/* must delete as __free_one_page list manipulates */
			list_del(&page->lru);
			__free_one_page(page, zone, 0, migratetype);
			trace_mm_page_pcpu_drain(page, 0, migratetype);
		} while (--count && --batch_free && !list_empty(list));
L
Linus Torvalds 已提交
565
	}
N
Nick Piggin 已提交
566
	spin_unlock(&zone->lock);
L
Linus Torvalds 已提交
567 568
}

569 570
static void free_one_page(struct zone *zone, struct page *page, int order,
				int migratetype)
L
Linus Torvalds 已提交
571
{
572
	spin_lock(&zone->lock);
573
	zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
574
	zone->pages_scanned = 0;
575 576

	__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
577
	__free_one_page(page, zone, order, migratetype);
578
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
579 580 581 582 583
}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
L
Linus Torvalds 已提交
584
	int i;
585
	int bad = 0;
586
	int wasMlocked = __TestClearPageMlocked(page);
L
Linus Torvalds 已提交
587

588 589
	kmemcheck_free_shadow(page, order);

L
Linus Torvalds 已提交
590
	for (i = 0 ; i < (1 << order) ; ++i)
591 592
		bad += free_pages_check(page + i);
	if (bad)
593 594
		return;

595
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
596
		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
597 598 599
		debug_check_no_obj_freed(page_address(page),
					   PAGE_SIZE << order);
	}
N
Nick Piggin 已提交
600
	arch_free_page(page, order);
N
Nick Piggin 已提交
601
	kernel_map_pages(page, 1 << order, 0);
N
Nick Piggin 已提交
602

N
Nick Piggin 已提交
603
	local_irq_save(flags);
604
	if (unlikely(wasMlocked))
605
		free_page_mlock(page);
606
	__count_vm_events(PGFREE, 1 << order);
607 608
	free_one_page(page_zone(page), page, order,
					get_pageblock_migratetype(page));
N
Nick Piggin 已提交
609
	local_irq_restore(flags);
L
Linus Torvalds 已提交
610 611
}

612 613 614
/*
 * permit the bootmem allocator to evade page validation on high-order frees
 */
615
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
616 617 618 619
{
	if (order == 0) {
		__ClearPageReserved(page);
		set_page_count(page, 0);
620
		set_page_refcounted(page);
N
Nick Piggin 已提交
621
		__free_page(page);
622 623 624
	} else {
		int loop;

N
Nick Piggin 已提交
625
		prefetchw(page);
626 627 628
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

N
Nick Piggin 已提交
629 630
			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
631 632 633 634
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

635
		set_page_refcounted(page);
N
Nick Piggin 已提交
636
		__free_pages(page, order);
637 638 639
	}
}

L
Linus Torvalds 已提交
640 641 642 643 644 645 646 647 648 649 650 651 652 653 654

/*
 * 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
655
static inline void expand(struct zone *zone, struct page *page,
656 657
	int low, int high, struct free_area *area,
	int migratetype)
L
Linus Torvalds 已提交
658 659 660 661 662 663 664
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
665
		VM_BUG_ON(bad_range(zone, &page[size]));
666
		list_add(&page[size].lru, &area->free_list[migratetype]);
L
Linus Torvalds 已提交
667 668 669 670 671 672 673 674
		area->nr_free++;
		set_page_order(&page[size], high);
	}
}

/*
 * This page is about to be returned from the page allocator
 */
675
static inline int check_new_page(struct page *page)
L
Linus Torvalds 已提交
676
{
N
Nick Piggin 已提交
677 678
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
679
		(atomic_read(&page->_count) != 0)  |
680
		(page->flags & PAGE_FLAGS_CHECK_AT_PREP))) {
N
Nick Piggin 已提交
681
		bad_page(page);
682
		return 1;
683
	}
684 685 686 687 688 689 690 691 692 693 694 695
	return 0;
}

static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
{
	int i;

	for (i = 0; i < (1 << order); i++) {
		struct page *p = page + i;
		if (unlikely(check_new_page(p)))
			return 1;
	}
696

H
Hugh Dickins 已提交
697
	set_page_private(page, 0);
698
	set_page_refcounted(page);
N
Nick Piggin 已提交
699 700

	arch_alloc_page(page, order);
L
Linus Torvalds 已提交
701
	kernel_map_pages(page, 1 << order, 1);
N
Nick Piggin 已提交
702 703 704 705 706 707 708

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

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

709
	return 0;
L
Linus Torvalds 已提交
710 711
}

712 713 714 715
/*
 * Go through the free lists for the given migratetype and remove
 * the smallest available page from the freelists
 */
716 717
static inline
struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742
						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;
}


743 744 745 746 747
/*
 * 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] = {
748 749 750 751
	[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 */
752 753
};

754 755
/*
 * Move the free pages in a range to the free lists of the requested type.
756
 * Note that start_page and end_pages are not aligned on a pageblock
757 758
 * boundary. If alignment is required, use move_freepages_block()
 */
A
Adrian Bunk 已提交
759 760 761
static int move_freepages(struct zone *zone,
			  struct page *start_page, struct page *end_page,
			  int migratetype)
762 763 764
{
	struct page *page;
	unsigned long order;
765
	int pages_moved = 0;
766 767 768 769 770 771 772

#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
773
	 * grouping pages by mobility
774 775 776 777 778
	 */
	BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif

	for (page = start_page; page <= end_page;) {
779 780 781
		/* Make sure we are not inadvertently changing nodes */
		VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));

782 783 784 785 786 787 788 789 790 791 792 793 794 795 796
		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;
797
		pages_moved += 1 << order;
798 799
	}

800
	return pages_moved;
801 802
}

A
Adrian Bunk 已提交
803 804
static int move_freepages_block(struct zone *zone, struct page *page,
				int migratetype)
805 806 807 808 809
{
	unsigned long start_pfn, end_pfn;
	struct page *start_page, *end_page;

	start_pfn = page_to_pfn(page);
810
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
811
	start_page = pfn_to_page(start_pfn);
812 813
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
814 815 816 817 818 819 820 821 822 823

	/* 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);
}

824 825 826 827 828 829 830 831 832 833 834
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;
	}
}

835
/* Remove an element from the buddy allocator from the fallback list */
836 837
static inline struct page *
__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
838 839 840 841 842 843 844 845 846 847 848 849
{
	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];

850 851 852
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
				continue;
M
Mel Gorman 已提交
853

854 855 856 857 858 859 860 861 862
			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--;

			/*
863
			 * If breaking a large block of pages, move all free
864 865 866
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
			 * agressive about taking ownership of free pages
867
			 */
868
			if (unlikely(current_order >= (pageblock_order >> 1)) ||
869 870
					start_migratetype == MIGRATE_RECLAIMABLE ||
					page_group_by_mobility_disabled) {
871 872 873 874 875
				unsigned long pages;
				pages = move_freepages_block(zone, page,
								start_migratetype);

				/* Claim the whole block if over half of it is free */
876 877
				if (pages >= (1 << (pageblock_order-1)) ||
						page_group_by_mobility_disabled)
878 879 880
					set_pageblock_migratetype(page,
								start_migratetype);

881
				migratetype = start_migratetype;
882
			}
883 884 885 886 887

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

888 889 890
			/* Take ownership for orders >= pageblock_order */
			if (current_order >= pageblock_order)
				change_pageblock_range(page, current_order,
891 892 893
							start_migratetype);

			expand(zone, page, order, current_order, area, migratetype);
894 895 896 897

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

898 899 900 901
			return page;
		}
	}

902
	return NULL;
903 904
}

905
/*
L
Linus Torvalds 已提交
906 907 908
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
909 910
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
L
Linus Torvalds 已提交
911 912 913
{
	struct page *page;

914
retry_reserve:
915
	page = __rmqueue_smallest(zone, order, migratetype);
916

917
	if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
918
		page = __rmqueue_fallback(zone, order, migratetype);
919

920 921 922 923 924 925 926 927 928 929 930
		/*
		 * 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;
		}
	}

931
	trace_mm_page_alloc_zone_locked(page, order, migratetype);
932
	return page;
L
Linus Torvalds 已提交
933 934 935 936 937 938 939 940
}

/* 
 * 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, 
941
			unsigned long count, struct list_head *list,
942
			int migratetype, int cold)
L
Linus Torvalds 已提交
943 944 945
{
	int i;
	
N
Nick Piggin 已提交
946
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
947
	for (i = 0; i < count; ++i) {
948
		struct page *page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
949
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
950
			break;
951 952 953 954 955 956 957 958 959 960

		/*
		 * 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.
		 */
961 962 963 964
		if (likely(cold == 0))
			list_add(&page->lru, list);
		else
			list_add_tail(&page->lru, list);
965
		set_page_private(page, migratetype);
966
		list = &page->lru;
L
Linus Torvalds 已提交
967
	}
968
	__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
N
Nick Piggin 已提交
969
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
970
	return i;
L
Linus Torvalds 已提交
971 972
}

973
#ifdef CONFIG_NUMA
974
/*
975 976 977 978
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
979 980
 * Note that this function must be called with the thread pinned to
 * a single processor.
981
 */
982
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
983 984
{
	unsigned long flags;
985
	int to_drain;
986

987 988 989 990 991
	local_irq_save(flags);
	if (pcp->count >= pcp->batch)
		to_drain = pcp->batch;
	else
		to_drain = pcp->count;
992
	free_pcppages_bulk(zone, to_drain, pcp);
993 994
	pcp->count -= to_drain;
	local_irq_restore(flags);
995 996 997
}
#endif

998 999 1000 1001 1002 1003 1004 1005
/*
 * 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
1006
{
N
Nick Piggin 已提交
1007
	unsigned long flags;
L
Linus Torvalds 已提交
1008 1009
	struct zone *zone;

1010
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
1011
		struct per_cpu_pageset *pset;
1012
		struct per_cpu_pages *pcp;
L
Linus Torvalds 已提交
1013

1014
		pset = zone_pcp(zone, cpu);
1015 1016 1017

		pcp = &pset->pcp;
		local_irq_save(flags);
1018
		free_pcppages_bulk(zone, pcp->count, pcp);
1019 1020
		pcp->count = 0;
		local_irq_restore(flags);
L
Linus Torvalds 已提交
1021 1022 1023
	}
}

1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036
/*
 * 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)
{
1037
	on_each_cpu(drain_local_pages, NULL, 1);
1038 1039
}

1040
#ifdef CONFIG_HIBERNATION
L
Linus Torvalds 已提交
1041 1042 1043

void mark_free_pages(struct zone *zone)
{
1044 1045
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
1046
	int order, t;
L
Linus Torvalds 已提交
1047 1048 1049 1050 1051 1052
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
1053 1054 1055 1056 1057 1058

	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);

1059 1060
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
1061
		}
L
Linus Torvalds 已提交
1062

1063 1064
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
1065
			unsigned long i;
L
Linus Torvalds 已提交
1066

1067 1068
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
1069
				swsusp_set_page_free(pfn_to_page(pfn + i));
1070
		}
1071
	}
L
Linus Torvalds 已提交
1072 1073
	spin_unlock_irqrestore(&zone->lock, flags);
}
1074
#endif /* CONFIG_PM */
L
Linus Torvalds 已提交
1075 1076 1077 1078

/*
 * Free a 0-order page
 */
H
Harvey Harrison 已提交
1079
static void free_hot_cold_page(struct page *page, int cold)
L
Linus Torvalds 已提交
1080 1081 1082 1083
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;
1084
	int migratetype;
1085
	int wasMlocked = __TestClearPageMlocked(page);
L
Linus Torvalds 已提交
1086

1087 1088
	kmemcheck_free_shadow(page, 0);

L
Linus Torvalds 已提交
1089 1090
	if (PageAnon(page))
		page->mapping = NULL;
N
Nick Piggin 已提交
1091
	if (free_pages_check(page))
1092 1093
		return;

1094
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
1095
		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
1096 1097
		debug_check_no_obj_freed(page_address(page), PAGE_SIZE);
	}
N
Nick Piggin 已提交
1098
	arch_free_page(page, 0);
1099 1100
	kernel_map_pages(page, 1, 0);

1101
	pcp = &zone_pcp(zone, get_cpu())->pcp;
1102 1103
	migratetype = get_pageblock_migratetype(page);
	set_page_private(page, migratetype);
L
Linus Torvalds 已提交
1104
	local_irq_save(flags);
1105
	if (unlikely(wasMlocked))
1106
		free_page_mlock(page);
1107
	__count_vm_event(PGFREE);
1108

1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123
	/*
	 * We only track unmovable, reclaimable and movable on pcp lists.
	 * Free ISOLATE pages back to the allocator because they are being
	 * offlined but treat RESERVE as movable pages so we can get those
	 * areas back if necessary. Otherwise, we may have to free
	 * excessively into the page allocator
	 */
	if (migratetype >= MIGRATE_PCPTYPES) {
		if (unlikely(migratetype == MIGRATE_ISOLATE)) {
			free_one_page(zone, page, 0, migratetype);
			goto out;
		}
		migratetype = MIGRATE_MOVABLE;
	}

1124
	if (cold)
1125
		list_add_tail(&page->lru, &pcp->lists[migratetype]);
1126
	else
1127
		list_add(&page->lru, &pcp->lists[migratetype]);
L
Linus Torvalds 已提交
1128
	pcp->count++;
N
Nick Piggin 已提交
1129
	if (pcp->count >= pcp->high) {
1130
		free_pcppages_bulk(zone, pcp->batch, pcp);
N
Nick Piggin 已提交
1131 1132
		pcp->count -= pcp->batch;
	}
1133 1134

out:
L
Linus Torvalds 已提交
1135 1136 1137 1138
	local_irq_restore(flags);
	put_cpu();
}

H
Harvey Harrison 已提交
1139
void free_hot_page(struct page *page)
L
Linus Torvalds 已提交
1140
{
1141
	trace_mm_page_free_direct(page, 0);
L
Linus Torvalds 已提交
1142 1143 1144
	free_hot_cold_page(page, 0);
}
	
N
Nick Piggin 已提交
1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156
/*
 * 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
1157 1158
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1159 1160 1161 1162 1163 1164 1165 1166 1167 1168

#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

1169 1170
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
1171 1172
}

L
Linus Torvalds 已提交
1173 1174 1175 1176 1177
/*
 * 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.
 */
1178 1179
static inline
struct page *buffered_rmqueue(struct zone *preferred_zone,
1180 1181
			struct zone *zone, int order, gfp_t gfp_flags,
			int migratetype)
L
Linus Torvalds 已提交
1182 1183
{
	unsigned long flags;
1184
	struct page *page;
L
Linus Torvalds 已提交
1185
	int cold = !!(gfp_flags & __GFP_COLD);
N
Nick Piggin 已提交
1186
	int cpu;
L
Linus Torvalds 已提交
1187

1188
again:
N
Nick Piggin 已提交
1189
	cpu  = get_cpu();
N
Nick Piggin 已提交
1190
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1191
		struct per_cpu_pages *pcp;
1192
		struct list_head *list;
L
Linus Torvalds 已提交
1193

1194
		pcp = &zone_pcp(zone, cpu)->pcp;
1195
		list = &pcp->lists[migratetype];
L
Linus Torvalds 已提交
1196
		local_irq_save(flags);
1197
		if (list_empty(list)) {
1198
			pcp->count += rmqueue_bulk(zone, 0,
1199
					pcp->batch, list,
1200
					migratetype, cold);
1201
			if (unlikely(list_empty(list)))
1202
				goto failed;
1203
		}
1204

1205 1206 1207 1208 1209
		if (cold)
			page = list_entry(list->prev, struct page, lru);
		else
			page = list_entry(list->next, struct page, lru);

1210 1211
		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1212
	} else {
1213 1214 1215 1216 1217 1218 1219 1220
		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
1221
			 * allocate greater than order-1 page units with
1222 1223
			 * __GFP_NOFAIL.
			 */
1224
			WARN_ON_ONCE(order > 1);
1225
		}
L
Linus Torvalds 已提交
1226
		spin_lock_irqsave(&zone->lock, flags);
1227
		page = __rmqueue(zone, order, migratetype);
1228
		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
N
Nick Piggin 已提交
1229 1230 1231
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
L
Linus Torvalds 已提交
1232 1233
	}

1234
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1235
	zone_statistics(preferred_zone, zone);
N
Nick Piggin 已提交
1236 1237
	local_irq_restore(flags);
	put_cpu();
L
Linus Torvalds 已提交
1238

N
Nick Piggin 已提交
1239
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1240
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1241
		goto again;
L
Linus Torvalds 已提交
1242
	return page;
N
Nick Piggin 已提交
1243 1244 1245 1246 1247

failed:
	local_irq_restore(flags);
	put_cpu();
	return NULL;
L
Linus Torvalds 已提交
1248 1249
}

1250 1251 1252 1253 1254 1255 1256 1257 1258
/* 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)

1259 1260 1261
#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
1262

1263 1264 1265 1266 1267 1268 1269
#ifdef CONFIG_FAIL_PAGE_ALLOC

static struct fail_page_alloc_attr {
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1270
	u32 min_order;
1271 1272 1273 1274 1275

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

	struct dentry *ignore_gfp_highmem_file;
	struct dentry *ignore_gfp_wait_file;
1276
	struct dentry *min_order_file;
1277 1278 1279 1280 1281

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1282 1283
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1284
	.min_order = 1,
1285 1286 1287 1288 1289 1290 1291 1292 1293 1294
};

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)
{
1295 1296
	if (order < fail_page_alloc.min_order)
		return 0;
1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327
	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);
1328 1329 1330
	fail_page_alloc.min_order_file =
		debugfs_create_u32("min-order", mode, dir,
				   &fail_page_alloc.min_order);
1331 1332

	if (!fail_page_alloc.ignore_gfp_wait_file ||
1333 1334
            !fail_page_alloc.ignore_gfp_highmem_file ||
            !fail_page_alloc.min_order_file) {
1335 1336 1337
		err = -ENOMEM;
		debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
		debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1338
		debugfs_remove(fail_page_alloc.min_order_file);
1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357
		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
1358 1359 1360 1361 1362
/*
 * 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
1363
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
1364 1365
{
	/* free_pages my go negative - that's OK */
1366 1367
	long min = mark;
	long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
L
Linus Torvalds 已提交
1368 1369
	int o;

R
Rohit Seth 已提交
1370
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1371
		min -= min / 2;
R
Rohit Seth 已提交
1372
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389
		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;
}

1390 1391 1392 1393 1394 1395
#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
1396
 * that have to skip over a lot of full or unallowed zones.
1397 1398 1399
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1400
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421
 *
 * 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
1422
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1423 1424 1425 1426 1427 1428
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1429
					&node_states[N_HIGH_MEMORY];
1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454
	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.
 */
1455
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1456 1457 1458 1459 1460 1461 1462 1463 1464 1465
						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;

1466
	i = z - zonelist->_zonerefs;
1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477
	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.
 */
1478
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1479 1480 1481 1482 1483 1484 1485 1486
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

1487
	i = z - zonelist->_zonerefs;
1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

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

1499
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1500 1501 1502 1503 1504
				nodemask_t *allowednodes)
{
	return 1;
}

1505
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1506 1507 1508 1509
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1510
/*
1511
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1512 1513 1514
 * a page.
 */
static struct page *
1515
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1516
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1517
		struct zone *preferred_zone, int migratetype)
M
Martin Hicks 已提交
1518
{
1519
	struct zoneref *z;
R
Rohit Seth 已提交
1520
	struct page *page = NULL;
1521
	int classzone_idx;
1522
	struct zone *zone;
1523 1524 1525
	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 */
1526

1527
	classzone_idx = zone_idx(preferred_zone);
1528
zonelist_scan:
R
Rohit Seth 已提交
1529
	/*
1530
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1531 1532
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1533 1534
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1535 1536 1537
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1538
		if ((alloc_flags & ALLOC_CPUSET) &&
1539
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1540
				goto try_next_zone;
R
Rohit Seth 已提交
1541

1542
		BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
R
Rohit Seth 已提交
1543
		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1544
			unsigned long mark;
1545 1546
			int ret;

1547
			mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566
			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))
1567
					goto this_zone_full;
1568
			}
R
Rohit Seth 已提交
1569 1570
		}

1571
try_this_zone:
1572 1573
		page = buffered_rmqueue(preferred_zone, zone, order,
						gfp_mask, migratetype);
1574
		if (page)
R
Rohit Seth 已提交
1575
			break;
1576 1577 1578 1579
this_zone_full:
		if (NUMA_BUILD)
			zlc_mark_zone_full(zonelist, z);
try_next_zone:
1580
		if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1581 1582 1583 1584
			/*
			 * we do zlc_setup after the first zone is tried but only
			 * if there are multiple nodes make it worthwhile
			 */
1585 1586 1587 1588
			allowednodes = zlc_setup(zonelist, alloc_flags);
			zlc_active = 1;
			did_zlc_setup = 1;
		}
1589
	}
1590 1591 1592 1593 1594 1595

	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
1596
	return page;
M
Martin Hicks 已提交
1597 1598
}

1599 1600 1601
static inline int
should_alloc_retry(gfp_t gfp_mask, unsigned int order,
				unsigned long pages_reclaimed)
L
Linus Torvalds 已提交
1602
{
1603 1604 1605
	/* Do not loop if specifically requested */
	if (gfp_mask & __GFP_NORETRY)
		return 0;
L
Linus Torvalds 已提交
1606

1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623
	/*
	 * 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;
1624

1625 1626 1627 1628 1629 1630
	/*
	 * 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
1631

1632 1633
	return 0;
}
1634

1635 1636 1637
static inline struct page *
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1638 1639
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1640 1641 1642 1643 1644 1645
{
	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
1646 1647
		return NULL;
	}
1648

1649 1650 1651 1652 1653 1654 1655
	/*
	 * 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,
1656
		ALLOC_WMARK_HIGH|ALLOC_CPUSET,
1657
		preferred_zone, migratetype);
R
Rohit Seth 已提交
1658
	if (page)
1659 1660 1661
		goto out;

	/* The OOM killer will not help higher order allocs */
1662
	if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_NOFAIL))
1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676
		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,
1677
	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1678
	int migratetype, unsigned long *did_some_progress)
1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705
{
	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,
1706
					zonelist, high_zoneidx,
1707 1708
					alloc_flags, preferred_zone,
					migratetype);
1709 1710 1711
	return page;
}

L
Linus Torvalds 已提交
1712
/*
1713 1714
 * 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
1715
 */
1716 1717 1718
static inline struct page *
__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1719 1720
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1721 1722 1723 1724 1725
{
	struct page *page;

	do {
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1726
			zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
1727
			preferred_zone, migratetype);
1728 1729

		if (!page && gfp_mask & __GFP_NOFAIL)
1730
			congestion_wait(BLK_RW_ASYNC, HZ/50);
1731 1732 1733 1734 1735 1736 1737 1738
	} 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
1739
{
1740 1741
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
1742

1743 1744 1745
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
		wakeup_kswapd(zone, order);
}
1746

1747 1748 1749 1750 1751 1752
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
1753

1754 1755
	/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
	BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH);
1756

1757 1758 1759 1760 1761 1762
	/*
	 * 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).
	 */
1763
	alloc_flags |= (gfp_mask & __GFP_HIGH);
L
Linus Torvalds 已提交
1764

1765 1766
	if (!wait) {
		alloc_flags |= ALLOC_HARDER;
1767
		/*
1768 1769
		 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
		 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1770
		 */
1771 1772 1773 1774 1775 1776 1777 1778 1779
		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
1780
	}
1781

1782 1783 1784
	return alloc_flags;
}

1785 1786 1787
static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1788 1789
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1790 1791 1792 1793 1794 1795 1796
{
	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
1797

1798 1799 1800 1801 1802 1803
	/*
	 * 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.
	 */
1804 1805
	if (order >= MAX_ORDER) {
		WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
1806
		return NULL;
1807
	}
L
Linus Torvalds 已提交
1808

1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819
	/*
	 * 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;

1820
restart:
1821
	wake_all_kswapd(order, zonelist, high_zoneidx);
L
Linus Torvalds 已提交
1822

1823
	/*
R
Rohit Seth 已提交
1824 1825 1826
	 * 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.
1827
	 */
1828
	alloc_flags = gfp_to_alloc_flags(gfp_mask);
L
Linus Torvalds 已提交
1829

1830
	/* This is the last chance, in general, before the goto nopage. */
1831
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1832 1833
			high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
			preferred_zone, migratetype);
R
Rohit Seth 已提交
1834 1835
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1836

1837
rebalance:
1838
	/* Allocate without watermarks if the context allows */
1839 1840 1841 1842 1843 1844
	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
1845 1846 1847 1848 1849 1850
	}

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

1851 1852 1853 1854
	/* Avoid recursion of direct reclaim */
	if (p->flags & PF_MEMALLOC)
		goto nopage;

1855 1856 1857 1858
	/* Avoid allocations with no watermarks from looping endlessly */
	if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
		goto nopage;

1859 1860 1861 1862
	/* Try direct reclaim and then allocating */
	page = __alloc_pages_direct_reclaim(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
1863
					alloc_flags, preferred_zone,
1864
					migratetype, &did_some_progress);
1865 1866
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1867

1868
	/*
1869 1870
	 * If we failed to make any progress reclaiming, then we are
	 * running out of options and have to consider going OOM
1871
	 */
1872 1873
	if (!did_some_progress) {
		if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1874 1875
			if (oom_killer_disabled)
				goto nopage;
1876 1877
			page = __alloc_pages_may_oom(gfp_mask, order,
					zonelist, high_zoneidx,
1878 1879
					nodemask, preferred_zone,
					migratetype);
1880 1881
			if (page)
				goto got_pg;
L
Linus Torvalds 已提交
1882

1883
			/*
1884 1885 1886 1887
			 * 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.
1888
			 */
1889 1890
			if (order > PAGE_ALLOC_COSTLY_ORDER &&
						!(gfp_mask & __GFP_NOFAIL))
1891
				goto nopage;
1892

1893 1894
			goto restart;
		}
L
Linus Torvalds 已提交
1895 1896
	}

1897
	/* Check if we should retry the allocation */
1898
	pages_reclaimed += did_some_progress;
1899 1900
	if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
		/* Wait for some write requests to complete then retry */
1901
		congestion_wait(BLK_RW_ASYNC, HZ/50);
L
Linus Torvalds 已提交
1902 1903 1904 1905 1906 1907 1908 1909 1910
		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
1911
		show_mem();
L
Linus Torvalds 已提交
1912
	}
1913
	return page;
L
Linus Torvalds 已提交
1914
got_pg:
1915 1916
	if (kmemcheck_enabled)
		kmemcheck_pagealloc_alloc(page, order, gfp_mask);
L
Linus Torvalds 已提交
1917
	return page;
1918

L
Linus Torvalds 已提交
1919
}
1920 1921 1922 1923 1924 1925 1926 1927 1928

/*
 * 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);
1929
	struct zone *preferred_zone;
1930
	struct page *page;
1931
	int migratetype = allocflags_to_migratetype(gfp_mask);
1932

1933 1934
	gfp_mask &= gfp_allowed_mask;

1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949
	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;

1950 1951 1952 1953 1954 1955
	/* 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 */
1956
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
1957
			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
1958
			preferred_zone, migratetype);
1959 1960
	if (unlikely(!page))
		page = __alloc_pages_slowpath(gfp_mask, order,
1961
				zonelist, high_zoneidx, nodemask,
1962
				preferred_zone, migratetype);
1963

1964
	trace_mm_page_alloc(page, order, gfp_mask, migratetype);
1965
	return page;
L
Linus Torvalds 已提交
1966
}
1967
EXPORT_SYMBOL(__alloc_pages_nodemask);
L
Linus Torvalds 已提交
1968 1969 1970 1971

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
1972
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
1973
{
1974 1975 1976 1977 1978 1979 1980 1981
	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
1982 1983 1984 1985 1986 1987 1988
	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
1989
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
1990
{
1991
	return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
L
Linus Torvalds 已提交
1992 1993 1994 1995 1996 1997 1998
}
EXPORT_SYMBOL(get_zeroed_page);

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

1999 2000
	while (--i >= 0) {
		trace_mm_pagevec_free(pvec->pages[i], pvec->cold);
L
Linus Torvalds 已提交
2001
		free_hot_cold_page(pvec->pages[i], pvec->cold);
2002
	}
L
Linus Torvalds 已提交
2003 2004
}

H
Harvey Harrison 已提交
2005
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
2006
{
N
Nick Piggin 已提交
2007
	if (put_page_testzero(page)) {
2008
		trace_mm_page_free_direct(page, order);
L
Linus Torvalds 已提交
2009 2010 2011 2012 2013 2014 2015 2016 2017
		if (order == 0)
			free_hot_page(page);
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
2018
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
2019 2020
{
	if (addr != 0) {
N
Nick Piggin 已提交
2021
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
2022 2023 2024 2025 2026 2027
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050
/**
 * 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
2051
		split_page(virt_to_page((void *)addr), order);
2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080
		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
2081 2082
static unsigned int nr_free_zone_pages(int offset)
{
2083
	struct zoneref *z;
2084 2085
	struct zone *zone;

2086
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
2087 2088
	unsigned int sum = 0;

2089
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
2090

2091
	for_each_zone_zonelist(zone, z, zonelist, offset) {
2092
		unsigned long size = zone->present_pages;
2093
		unsigned long high = high_wmark_pages(zone);
2094 2095
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
2096 2097 2098 2099 2100 2101 2102 2103 2104 2105
	}

	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
2106
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
2107
}
2108
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
2109 2110 2111 2112 2113 2114

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
2115
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
2116
}
2117 2118

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
2119
{
2120
	if (NUMA_BUILD)
2121
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
2122 2123 2124 2125 2126 2127
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
2128
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142
	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;
2143
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
2144
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2145
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2146 2147
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
2148 2149 2150 2151
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164
	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)
{
2165
	int cpu;
L
Linus Torvalds 已提交
2166 2167
	struct zone *zone;

2168
	for_each_populated_zone(zone) {
2169 2170
		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
2171

2172
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
2173 2174
			struct per_cpu_pageset *pageset;

2175
			pageset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
2176

2177 2178 2179
			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
2180 2181 2182
		}
	}

K
KOSAKI Motohiro 已提交
2183 2184
	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
2185
		" unevictable:%lu"
2186
		" dirty:%lu writeback:%lu unstable:%lu\n"
2187
		" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2188
		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2189 2190
		global_page_state(NR_ACTIVE_ANON),
		global_page_state(NR_INACTIVE_ANON),
K
KOSAKI Motohiro 已提交
2191 2192
		global_page_state(NR_ISOLATED_ANON),
		global_page_state(NR_ACTIVE_FILE),
2193
		global_page_state(NR_INACTIVE_FILE),
K
KOSAKI Motohiro 已提交
2194
		global_page_state(NR_ISOLATED_FILE),
L
Lee Schermerhorn 已提交
2195
		global_page_state(NR_UNEVICTABLE),
2196
		global_page_state(NR_FILE_DIRTY),
2197
		global_page_state(NR_WRITEBACK),
2198
		global_page_state(NR_UNSTABLE_NFS),
2199
		global_page_state(NR_FREE_PAGES),
2200 2201
		global_page_state(NR_SLAB_RECLAIMABLE),
		global_page_state(NR_SLAB_UNRECLAIMABLE),
2202
		global_page_state(NR_FILE_MAPPED),
2203
		global_page_state(NR_SHMEM),
2204 2205
		global_page_state(NR_PAGETABLE),
		global_page_state(NR_BOUNCE));
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2207
	for_each_populated_zone(zone) {
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2208 2209 2210 2211 2212 2213 2214 2215
		int i;

		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
2216 2217 2218 2219
			" active_anon:%lukB"
			" inactive_anon:%lukB"
			" active_file:%lukB"
			" inactive_file:%lukB"
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			" unevictable:%lukB"
K
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2221 2222
			" isolated(anon):%lukB"
			" isolated(file):%lukB"
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2223
			" present:%lukB"
2224 2225 2226 2227
			" mlocked:%lukB"
			" dirty:%lukB"
			" writeback:%lukB"
			" mapped:%lukB"
2228
			" shmem:%lukB"
2229 2230
			" slab_reclaimable:%lukB"
			" slab_unreclaimable:%lukB"
2231
			" kernel_stack:%lukB"
2232 2233 2234 2235
			" pagetables:%lukB"
			" unstable:%lukB"
			" bounce:%lukB"
			" writeback_tmp:%lukB"
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2236 2237 2238 2239
			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
2240
			K(zone_page_state(zone, NR_FREE_PAGES)),
2241 2242 2243
			K(min_wmark_pages(zone)),
			K(low_wmark_pages(zone)),
			K(high_wmark_pages(zone)),
2244 2245 2246 2247
			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),
2252 2253 2254 2255
			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)),
2256
			K(zone_page_state(zone, NR_SHMEM)),
2257 2258
			K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
			K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
2259 2260
			zone_page_state(zone, NR_KERNEL_STACK) *
				THREAD_SIZE / 1024,
2261 2262 2263 2264
			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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2265
			zone->pages_scanned,
2266
			(zone_is_all_unreclaimable(zone) ? "yes" : "no")
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2267 2268 2269 2270 2271 2272 2273
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

2274
	for_each_populated_zone(zone) {
2275
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
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2276 2277 2278 2279 2280 2281

		show_node(zone);
		printk("%s: ", zone->name);

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
2282 2283
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
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		}
		spin_unlock_irqrestore(&zone->lock, flags);
2286 2287
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
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2288 2289 2290
		printk("= %lukB\n", K(total));
	}

2291 2292
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

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	show_swap_cache_info();
}

2296 2297 2298 2299 2300 2301
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.
2304 2305
 *
 * Add all populated zones of a node to the zonelist.
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 */
2307 2308
static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
				int nr_zones, enum zone_type zone_type)
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2309
{
2310 2311
	struct zone *zone;

2312
	BUG_ON(zone_type >= MAX_NR_ZONES);
2313
	zone_type++;
2314 2315

	do {
2316
		zone_type--;
2317
		zone = pgdat->node_zones + zone_type;
2318
		if (populated_zone(zone)) {
2319 2320
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
2321
			check_highest_zone(zone_type);
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2322
		}
2323

2324
	} while (zone_type);
2325
	return nr_zones;
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2326 2327
}

2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348

/*
 *  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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2349
#ifdef CONFIG_NUMA
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 2389 2390 2391 2392
/* 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,
2393
		void __user *buffer, size_t *length,
2394 2395 2396 2397 2398 2399 2400 2401
		loff_t *ppos)
{
	char saved_string[NUMA_ZONELIST_ORDER_LEN];
	int ret;

	if (write)
		strncpy(saved_string, (char*)table->data,
			NUMA_ZONELIST_ORDER_LEN);
2402
	ret = proc_dostring(table, write, buffer, length, ppos);
2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420
	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;
}


2421
#define MAX_NODE_LOAD (nr_online_nodes)
2422 2423
static int node_load[MAX_NUMNODES];

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2424
/**
2425
 * find_next_best_node - find the next node that should appear in a given node's fallback list
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2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437
 * @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.
 */
2438
static int find_next_best_node(int node, nodemask_t *used_node_mask)
L
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2439
{
2440
	int n, val;
L
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2441 2442
	int min_val = INT_MAX;
	int best_node = -1;
2443
	const struct cpumask *tmp = cpumask_of_node(0);
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2444

2445 2446 2447 2448 2449
	/* Use the local node if we haven't already */
	if (!node_isset(node, *used_node_mask)) {
		node_set(node, *used_node_mask);
		return node;
	}
L
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2450

2451
	for_each_node_state(n, N_HIGH_MEMORY) {
L
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2452 2453 2454 2455 2456 2457 2458 2459

		/* 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);

2460 2461 2462
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
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2463
		/* Give preference to headless and unused nodes */
2464 2465
		tmp = cpumask_of_node(n);
		if (!cpumask_empty(tmp))
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2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483
			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;
}

2484 2485 2486 2487 2488 2489 2490

/*
 * Build zonelists ordered by node and zones within node.
 * This results in maximum locality--normal zone overflows into local
 * DMA zone, if any--but risks exhausting DMA zone.
 */
static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
L
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2491
{
2492
	int j;
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2493
	struct zonelist *zonelist;
2494

2495
	zonelist = &pgdat->node_zonelists[0];
2496
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2497 2498 2499
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
2500 2501
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2502 2503
}

2504 2505 2506 2507 2508 2509 2510 2511
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

2512 2513
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2514 2515
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2516 2517
}

2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532
/*
 * 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;

2533 2534 2535 2536 2537 2538 2539
	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)) {
2540 2541
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
2542
				check_highest_zone(zone_type);
2543 2544 2545
			}
		}
	}
2546 2547
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
2548 2549 2550 2551 2552 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
}

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.
         */
2583 2584
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615
	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;
L
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2616
	nodemask_t used_mask;
2617 2618 2619
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
L
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2620 2621

	/* initialize zonelists */
2622
	for (i = 0; i < MAX_ZONELISTS; i++) {
L
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2623
		zonelist = pgdat->node_zonelists + i;
2624 2625
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
L
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2626 2627 2628 2629
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
2630
	load = nr_online_nodes;
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2631 2632
	prev_node = local_node;
	nodes_clear(used_mask);
2633 2634 2635 2636

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

L
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2637
	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2638 2639 2640 2641 2642 2643 2644 2645 2646
		int distance = node_distance(local_node, node);

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

L
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2647 2648 2649 2650 2651
		/*
		 * 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.
		 */
2652
		if (distance != node_distance(local_node, prev_node))
2653 2654
			node_load[node] = load;

L
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2655 2656
		prev_node = node;
		load--;
2657 2658 2659 2660 2661
		if (order == ZONELIST_ORDER_NODE)
			build_zonelists_in_node_order(pgdat, node);
		else
			node_order[j++] = node;	/* remember order */
	}
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2662

2663 2664 2665
	if (order == ZONELIST_ORDER_ZONE) {
		/* calculate node order -- i.e., DMA last! */
		build_zonelists_in_zone_order(pgdat, j);
L
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2666
	}
2667 2668

	build_thisnode_zonelists(pgdat);
L
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2669 2670
}

2671
/* Construct the zonelist performance cache - see further mmzone.h */
2672
static void build_zonelist_cache(pg_data_t *pgdat)
2673
{
2674 2675
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
2676
	struct zoneref *z;
2677

2678 2679 2680
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2681 2682
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2683 2684
}

2685

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2686 2687
#else	/* CONFIG_NUMA */

2688 2689 2690 2691 2692 2693
static void set_zonelist_order(void)
{
	current_zonelist_order = ZONELIST_ORDER_ZONE;
}

static void build_zonelists(pg_data_t *pgdat)
L
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2694
{
2695
	int node, local_node;
2696 2697
	enum zone_type j;
	struct zonelist *zonelist;
L
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2698 2699 2700

	local_node = pgdat->node_id;

2701 2702
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
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2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716
	/*
	 * 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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2717
	}
2718 2719 2720 2721 2722 2723 2724
	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);
	}

2725 2726
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
L
Linus Torvalds 已提交
2727 2728
}

2729
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2730
static void build_zonelist_cache(pg_data_t *pgdat)
2731
{
2732
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
2733 2734
}

L
Linus Torvalds 已提交
2735 2736
#endif	/* CONFIG_NUMA */

2737
/* return values int ....just for stop_machine() */
2738
static int __build_all_zonelists(void *dummy)
L
Linus Torvalds 已提交
2739
{
2740
	int nid;
2741

2742 2743 2744
#ifdef CONFIG_NUMA
	memset(node_load, 0, sizeof(node_load));
#endif
2745
	for_each_online_node(nid) {
2746 2747 2748 2749
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
2750
	}
2751 2752 2753
	return 0;
}

2754
void build_all_zonelists(void)
2755
{
2756 2757
	set_zonelist_order();

2758
	if (system_state == SYSTEM_BOOTING) {
2759
		__build_all_zonelists(NULL);
2760
		mminit_verify_zonelist();
2761 2762
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
2763
		/* we have to stop all cpus to guarantee there is no user
2764
		   of zonelist */
2765
		stop_machine(__build_all_zonelists, NULL, NULL);
2766 2767
		/* cpuset refresh routine should be here */
	}
2768
	vm_total_pages = nr_free_pagecache_pages();
2769 2770 2771 2772 2773 2774 2775
	/*
	 * 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
	 */
2776
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2777 2778 2779 2780 2781 2782
		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",
2783
			nr_online_nodes,
2784
			zonelist_order_name[current_zonelist_order],
2785
			page_group_by_mobility_disabled ? "off" : "on",
2786 2787 2788 2789
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
L
Linus Torvalds 已提交
2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804
}

/*
 * 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

2805
#ifndef CONFIG_MEMORY_HOTPLUG
2806
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823
{
	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);
}
2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846
#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
2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859

/*
 * 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))

2860
/*
2861
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2862 2863
 * 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
2864 2865 2866 2867 2868 2869 2870
 * 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;
2871 2872
	unsigned long block_migratetype;
	int reserve;
2873 2874 2875 2876

	/* 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;
2877
	reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
2878
							pageblock_order;
2879

2880 2881 2882 2883 2884 2885 2886 2887 2888
	/*
	 * 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);

2889
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2890 2891 2892 2893
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

2894 2895 2896 2897
		/* Watch out for overlapping nodes */
		if (page_to_nid(page) != zone_to_nid(zone))
			continue;

2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927
		/* 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
2928

L
Linus Torvalds 已提交
2929 2930 2931 2932 2933
/*
 * 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.
 */
2934
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
2935
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
2936 2937
{
	struct page *page;
A
Andy Whitcroft 已提交
2938 2939
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
2940
	struct zone *z;
L
Linus Torvalds 已提交
2941

2942 2943 2944
	if (highest_memmap_pfn < end_pfn - 1)
		highest_memmap_pfn = end_pfn - 1;

2945
	z = &NODE_DATA(nid)->node_zones[zone];
2946
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957
		/*
		 * 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
2958 2959
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
2960
		mminit_verify_page_links(page, zone, nid, pfn);
2961
		init_page_count(page);
L
Linus Torvalds 已提交
2962 2963
		reset_page_mapcount(page);
		SetPageReserved(page);
2964 2965 2966 2967 2968
		/*
		 * 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
2969 2970 2971
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
2972 2973 2974 2975 2976
		 *
		 * 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.
2977
		 */
2978 2979 2980
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
2981
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2982

L
Linus Torvalds 已提交
2983 2984 2985 2986
		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))
2987
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
2988 2989 2990 2991
#endif
	}
}

2992
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
2993
{
2994 2995 2996
	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
2997 2998 2999 3000 3001 3002
		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
3003
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
3004 3005
#endif

3006
static int zone_batchsize(struct zone *zone)
3007
{
3008
#ifdef CONFIG_MMU
3009 3010 3011 3012
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
3013
	 * size of the zone.  But no more than 1/2 of a meg.
3014 3015 3016 3017
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
3018 3019
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
3020 3021 3022 3023 3024
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
3025 3026 3027
	 * 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.
3028
	 *
3029 3030 3031 3032
	 * 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.
3033
	 */
3034
	batch = rounddown_pow_of_two(batch + batch/2) - 1;
3035

3036
	return batch;
3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053

#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
3054 3055
}

A
Adrian Bunk 已提交
3056
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3057 3058
{
	struct per_cpu_pages *pcp;
3059
	int migratetype;
3060

3061 3062
	memset(p, 0, sizeof(*p));

3063
	pcp = &p->pcp;
3064 3065 3066
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
3067 3068
	for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
		INIT_LIST_HEAD(&pcp->lists[migratetype]);
3069 3070
}

3071 3072 3073 3074 3075 3076 3077 3078 3079 3080
/*
 * 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;

3081
	pcp = &p->pcp;
3082 3083 3084 3085 3086 3087 3088
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}


3089 3090
#ifdef CONFIG_NUMA
/*
3091 3092 3093 3094 3095 3096 3097
 * 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.
3098 3099 3100 3101 3102 3103 3104 3105
 *
 * 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.
3106
 */
3107
static struct per_cpu_pageset boot_pageset[NR_CPUS];
3108 3109 3110

/*
 * Dynamically allocate memory for the
3111 3112
 * per cpu pageset array in struct zone.
 */
3113
static int __cpuinit process_zones(int cpu)
3114 3115
{
	struct zone *zone, *dzone;
3116 3117 3118
	int node = cpu_to_node(cpu);

	node_set_state(node, N_CPU);	/* this node has a cpu */
3119

3120
	for_each_populated_zone(zone) {
N
Nick Piggin 已提交
3121
		zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
3122
					 GFP_KERNEL, node);
N
Nick Piggin 已提交
3123
		if (!zone_pcp(zone, cpu))
3124 3125
			goto bad;

N
Nick Piggin 已提交
3126
		setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
3127 3128 3129 3130

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(zone_pcp(zone, cpu),
			 	(zone->present_pages / percpu_pagelist_fraction));
3131 3132 3133 3134 3135
	}

	return 0;
bad:
	for_each_zone(dzone) {
3136 3137
		if (!populated_zone(dzone))
			continue;
3138 3139
		if (dzone == zone)
			break;
N
Nick Piggin 已提交
3140
		kfree(zone_pcp(dzone, cpu));
3141
		zone_pcp(dzone, cpu) = &boot_pageset[cpu];
3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152
	}
	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);

3153 3154 3155
		/* Free per_cpu_pageset if it is slab allocated */
		if (pset != &boot_pageset[cpu])
			kfree(pset);
3156
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
3157 3158 3159
	}
}

3160
static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
3161 3162 3163 3164 3165 3166 3167
		unsigned long action,
		void *hcpu)
{
	int cpu = (long)hcpu;
	int ret = NOTIFY_OK;

	switch (action) {
3168
	case CPU_UP_PREPARE:
3169
	case CPU_UP_PREPARE_FROZEN:
3170 3171 3172 3173
		if (process_zones(cpu))
			ret = NOTIFY_BAD;
		break;
	case CPU_UP_CANCELED:
3174
	case CPU_UP_CANCELED_FROZEN:
3175
	case CPU_DEAD:
3176
	case CPU_DEAD_FROZEN:
3177 3178 3179 3180
		free_zone_pagesets(cpu);
		break;
	default:
		break;
3181 3182 3183 3184
	}
	return ret;
}

3185
static struct notifier_block __cpuinitdata pageset_notifier =
3186 3187
	{ &pageset_cpuup_callback, NULL, 0 };

3188
void __init setup_per_cpu_pageset(void)
3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202
{
	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
3203
static noinline __init_refok
3204
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3205 3206 3207
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
3208
	size_t alloc_size;
3209 3210 3211 3212 3213

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
3214 3215 3216 3217
	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);
3218 3219 3220
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

3221
	if (!slab_is_available()) {
3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234
		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.
		 */
3235
		zone->wait_table = vmalloc(alloc_size);
3236 3237 3238
	}
	if (!zone->wait_table)
		return -ENOMEM;
3239

3240
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3241
		init_waitqueue_head(zone->wait_table + i);
3242 3243

	return 0;
3244 3245
}

3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259
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);
3260
		free_pcppages_bulk(zone, pcp->count, pcp);
3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271
		setup_pageset(pset, batch);
		local_irq_restore(flags);
	}
	return 0;
}

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

3272
static __meminit void zone_pcp_init(struct zone *zone)
3273 3274 3275 3276 3277 3278 3279
{
	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
3280
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
3281 3282 3283 3284 3285
		setup_pageset(&boot_pageset[cpu],0);
#else
		setup_pageset(zone_pcp(zone,cpu), batch);
#endif
	}
A
Anton Blanchard 已提交
3286 3287 3288
	if (zone->present_pages)
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%lu\n",
			zone->name, zone->present_pages, batch);
3289 3290
}

3291 3292
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
3293 3294
					unsigned long size,
					enum memmap_context context)
3295 3296
{
	struct pglist_data *pgdat = zone->zone_pgdat;
3297 3298 3299 3300
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
3301 3302 3303 3304
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

3305 3306 3307 3308 3309 3310
	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));

3311
	zone_init_free_lists(zone);
3312 3313

	return 0;
3314 3315
}

3316 3317 3318 3319 3320
#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
 */
3321
static int __meminit first_active_region_index_in_nid(int nid)
3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333
{
	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
3334
 * Note: nid == MAX_NUMNODES returns next region regardless of node
3335
 */
3336
static int __meminit next_active_region_index_in_nid(int index, int nid)
3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351
{
	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
 */
3352
int __meminit __early_pfn_to_nid(unsigned long pfn)
3353 3354 3355 3356 3357 3358 3359 3360 3361 3362
{
	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;
	}
3363 3364
	/* This is a memory hole */
	return -1;
3365 3366 3367
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

3368 3369
int __meminit early_pfn_to_nid(unsigned long pfn)
{
3370 3371 3372 3373 3374 3375 3376
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0)
		return nid;
	/* just returns 0 */
	return 0;
3377 3378
}

3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389
#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
3390

3391 3392 3393 3394 3395 3396 3397
/* 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
3398 3399
 * @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
3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426
 *
 * 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);
	}
}

3427 3428 3429
void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
{
	int i;
3430
	int ret;
3431

3432 3433 3434 3435 3436 3437
	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;
	}
3438
}
3439 3440
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3441
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3442 3443 3444
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
3445
 * function may be used instead of calling memory_present() manually.
3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458
 */
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
3459 3460 3461
 * @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.
3462 3463 3464 3465
 *
 * 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
3466
 * PFNs will be 0.
3467
 */
3468
void __meminit get_pfn_range_for_nid(unsigned int nid,
3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479
			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);
	}

3480
	if (*start_pfn == -1UL)
3481 3482 3483
		*start_pfn = 0;
}

M
Mel Gorman 已提交
3484 3485 3486 3487 3488
/*
 * 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
3489
static void __init find_usable_zone_for_movable(void)
M
Mel Gorman 已提交
3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514
{
	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
3515
static void __meminit adjust_zone_range_for_zone_movable(int nid,
M
Mel Gorman 已提交
3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540
					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;
	}
}

3541 3542 3543 3544
/*
 * 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
3545
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3546 3547 3548 3549 3550 3551 3552 3553 3554 3555
					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
3556 3557 3558
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573

	/* 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,
3574
 * then all holes in the requested range will be accounted for.
3575
 */
A
Adrian Bunk 已提交
3576
static unsigned long __meminit __absent_pages_in_range(int nid,
3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588
				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;

3589 3590
	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);

3591 3592
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
3593
		hole_pages = prev_end_pfn - range_start_pfn;
3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613

	/* 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;
	}

3614 3615
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
3616
		hole_pages += range_end_pfn -
3617 3618
				max(range_start_pfn, prev_end_pfn);

3619 3620 3621 3622 3623 3624 3625 3626
	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
 *
3627
 * It returns the number of pages frames in memory holes within a range.
3628 3629 3630 3631 3632 3633 3634 3635
 */
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
3636
static unsigned long __meminit zone_absent_pages_in_node(int nid,
3637 3638 3639
					unsigned long zone_type,
					unsigned long *ignored)
{
3640 3641 3642 3643 3644 3645 3646 3647 3648
	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
3649 3650 3651
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
3652
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3653
}
3654

3655
#else
P
Paul Mundt 已提交
3656
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3657 3658 3659 3660 3661 3662
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
3663
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3664 3665 3666 3667 3668 3669 3670 3671
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
3672

3673 3674
#endif

3675
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695
		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);
}

3696 3697 3698
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
3699 3700
 * 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
3701 3702 3703 3704 3705 3706 3707
 * 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;

3708 3709
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720
	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;
3721
	if (usemapsize)
3722 3723 3724 3725 3726 3727 3728
		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 */

3729
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3730 3731 3732 3733 3734 3735 3736 3737 3738 3739

/* 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;
}

3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754
/* 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 */

3755 3756 3757 3758 3759 3760 3761 3762 3763 3764
/*
 * 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;
}
3765 3766 3767 3768
#define set_pageblock_order(x)	do {} while (0)

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
3769 3770 3771 3772 3773 3774
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
3775
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3776 3777
		unsigned long *zones_size, unsigned long *zholes_size)
{
3778
	enum zone_type j;
3779
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
3780
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
3781
	int ret;
L
Linus Torvalds 已提交
3782

3783
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
3784 3785 3786
	pgdat->nr_zones = 0;
	init_waitqueue_head(&pgdat->kswapd_wait);
	pgdat->kswapd_max_order = 0;
3787
	pgdat_page_cgroup_init(pgdat);
L
Linus Torvalds 已提交
3788 3789 3790
	
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
3791
		unsigned long size, realsize, memmap_pages;
3792
		enum lru_list l;
L
Linus Torvalds 已提交
3793

3794 3795 3796
		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
3797

3798 3799 3800 3801 3802
		/*
		 * 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
		 */
3803 3804
		memmap_pages =
			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
3805 3806
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
3807 3808 3809 3810
			if (memmap_pages)
				printk(KERN_DEBUG
				       "  %s zone: %lu pages used for memmap\n",
				       zone_names[j], memmap_pages);
3811 3812 3813 3814 3815
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

3816 3817
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
3818
			realsize -= dma_reserve;
Y
Yinghai Lu 已提交
3819
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
3820
					zone_names[0], dma_reserve);
3821 3822
		}

3823
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
3824 3825 3826 3827 3828
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
3829
#ifdef CONFIG_NUMA
3830
		zone->node = nid;
3831
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3832
						/ 100;
3833
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3834
#endif
L
Linus Torvalds 已提交
3835 3836 3837
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
3838
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
3839 3840
		zone->zone_pgdat = pgdat;

3841
		zone->prev_priority = DEF_PRIORITY;
L
Linus Torvalds 已提交
3842

3843
		zone_pcp_init(zone);
3844 3845
		for_each_lru(l) {
			INIT_LIST_HEAD(&zone->lru[l].list);
3846
			zone->reclaim_stat.nr_saved_scan[l] = 0;
3847
		}
3848 3849 3850 3851
		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;
3852
		zap_zone_vm_stats(zone);
3853
		zone->flags = 0;
L
Linus Torvalds 已提交
3854 3855 3856
		if (!size)
			continue;

3857
		set_pageblock_order(pageblock_default_order());
3858
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
3859 3860
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
3861
		BUG_ON(ret);
3862
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
3863 3864 3865 3866
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
3867
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
3868 3869 3870 3871 3872
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
3873
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
3874 3875
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
3876
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
3877 3878
		struct page *map;

3879 3880 3881 3882 3883 3884 3885 3886 3887
		/*
		 * 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);
3888 3889 3890
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
3891
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
3892
	}
3893
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
3894 3895 3896
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
3897
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
3898
		mem_map = NODE_DATA(0)->node_mem_map;
3899 3900
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3901
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3902 3903
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
3904
#endif
A
Andy Whitcroft 已提交
3905
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
3906 3907
}

3908 3909
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
3910
{
3911 3912
	pg_data_t *pgdat = NODE_DATA(nid);

L
Linus Torvalds 已提交
3913 3914
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
3915
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
3916 3917

	alloc_node_mem_map(pgdat);
3918 3919 3920 3921 3922
#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
3923 3924 3925 3926

	free_area_init_core(pgdat, zones_size, zholes_size);
}

3927
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
M
Miklos Szeredi 已提交
3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947

#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

3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964
/**
 * 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;

3965 3966 3967 3968 3969
	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);
3970

3971 3972
	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);

3973 3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011
	/* 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;
}

/**
4012
 * remove_active_range - Shrink an existing registered range of PFNs
4013
 * @nid: The node id the range is on that should be shrunk
4014 4015
 * @start_pfn: The new PFN of the range
 * @end_pfn: The new PFN of the range
4016 4017
 *
 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
4018 4019 4020
 * 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.
4021
 */
4022 4023
void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
				unsigned long end_pfn)
4024
{
4025 4026
	int i, j;
	int removed = 0;
4027

4028 4029 4030
	printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
			  nid, start_pfn, end_pfn);

4031
	/* Find the old active region end and shrink */
4032
	for_each_active_range_index_in_nid(i, nid) {
4033 4034
		if (early_node_map[i].start_pfn >= start_pfn &&
		    early_node_map[i].end_pfn <= end_pfn) {
4035
			/* clear it */
4036
			early_node_map[i].start_pfn = 0;
4037 4038 4039 4040
			early_node_map[i].end_pfn = 0;
			removed = 1;
			continue;
		}
4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052
		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;
4053
			continue;
4054
		}
4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073
	}

	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--;
	}
4074 4075 4076 4077
}

/**
 * remove_all_active_ranges - Remove all currently registered regions
4078
 *
4079 4080 4081 4082
 * 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.
 */
4083
void __init remove_all_active_ranges(void)
4084 4085 4086 4087 4088 4089 4090 4091 4092 4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111
{
	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);
}

4112
/* Find the lowest pfn for a node */
A
Adrian Bunk 已提交
4113
static unsigned long __init find_min_pfn_for_node(int nid)
4114 4115
{
	int i;
4116
	unsigned long min_pfn = ULONG_MAX;
4117

4118 4119
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
4120
		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
4121

4122 4123
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
4124
			"Could not find start_pfn for node %d\n", nid);
4125 4126 4127 4128
		return 0;
	}

	return min_pfn;
4129 4130 4131 4132 4133 4134
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
4135
 * add_active_range().
4136 4137 4138 4139 4140 4141
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

4142 4143 4144 4145 4146
/*
 * 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
4147
static unsigned long __init early_calculate_totalpages(void)
4148 4149 4150 4151
{
	int i;
	unsigned long totalpages = 0;

4152 4153
	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long pages = early_node_map[i].end_pfn -
4154
						early_node_map[i].start_pfn;
4155 4156 4157 4158 4159
		totalpages += pages;
		if (pages)
			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
	}
  	return totalpages;
4160 4161
}

M
Mel Gorman 已提交
4162 4163 4164 4165 4166 4167
/*
 * 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
4168
static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
M
Mel Gorman 已提交
4169 4170 4171 4172
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
4173 4174
	/* save the state before borrow the nodemask */
	nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4175 4176
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
4177

4178 4179 4180 4181 4182 4183 4184 4185 4186 4187 4188 4189 4190 4191 4192 4193 4194 4195 4196 4197 4198 4199
	/*
	 * 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
4200 4201
	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
	if (!required_kernelcore)
4202
		goto out;
M
Mel Gorman 已提交
4203 4204 4205 4206 4207 4208 4209 4210

	/* 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;
4211
	for_each_node_state(nid, N_HIGH_MEMORY) {
M
Mel Gorman 已提交
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 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300
		/*
		 * 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);
4301 4302 4303 4304

out:
	/* restore the node_state */
	node_states[N_HIGH_MEMORY] = saved_node_state;
M
Mel Gorman 已提交
4305 4306
}

4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320
/* 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
}

4321 4322
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
4323
 * @max_zone_pfn: an array of max PFNs for each zone
4324 4325 4326 4327 4328 4329 4330 4331 4332 4333 4334 4335 4336
 *
 * 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;
4337
	int i;
4338

4339 4340 4341
	/* Sort early_node_map as initialisation assumes it is sorted */
	sort_node_map();

4342 4343 4344 4345 4346 4347 4348 4349
	/* 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
4350 4351
		if (i == ZONE_MOVABLE)
			continue;
4352 4353 4354 4355 4356
		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
4357 4358 4359 4360 4361 4362
	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);
4363 4364 4365

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
M
Mel Gorman 已提交
4366 4367 4368
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
4369
		printk("  %-8s %0#10lx -> %0#10lx\n",
4370 4371 4372
				zone_names[i],
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);
M
Mel Gorman 已提交
4373 4374 4375 4376 4377 4378 4379 4380
	}

	/* 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]);
	}
4381 4382 4383 4384

	/* 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++)
4385
		printk("  %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4386 4387 4388 4389
						early_node_map[i].start_pfn,
						early_node_map[i].end_pfn);

	/* Initialise every node */
4390
	mminit_verify_pageflags_layout();
4391
	setup_nr_node_ids();
4392 4393
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
4394
		free_area_init_node(nid, NULL,
4395
				find_min_pfn_for_node(nid), NULL);
4396 4397 4398 4399 4400

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
4401 4402
	}
}
M
Mel Gorman 已提交
4403

4404
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
4405 4406 4407 4408 4409 4410
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
4411
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
4412

4413
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
4414 4415 4416 4417
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
4418

4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436
/*
 * 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
4437
early_param("kernelcore", cmdline_parse_kernelcore);
4438
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
4439

4440 4441
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

4442
/**
4443 4444
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
4445 4446 4447 4448
 *
 * 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
4449 4450 4451
 * 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.
4452 4453 4454 4455 4456 4457
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

4458
#ifndef CONFIG_NEED_MULTIPLE_NODES
4459
struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] };
L
Linus Torvalds 已提交
4460
EXPORT_SYMBOL(contig_page_data);
4461
#endif
L
Linus Torvalds 已提交
4462 4463 4464

void __init free_area_init(unsigned long *zones_size)
{
4465
	free_area_init_node(0, zones_size,
L
Linus Torvalds 已提交
4466 4467 4468 4469 4470 4471 4472 4473
			__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;

4474
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4475 4476 4477 4478 4479 4480 4481 4482
		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.
		 */
4483
		vm_events_fold_cpu(cpu);
4484 4485 4486 4487 4488 4489 4490 4491

		/*
		 * 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.
		 */
4492
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
4493 4494 4495 4496 4497 4498 4499 4500 4501
	}
	return NOTIFY_OK;
}

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

4502 4503 4504 4505 4506 4507 4508 4509
/*
 * 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;
4510
	enum zone_type i, j;
4511 4512 4513 4514 4515 4516 4517 4518 4519 4520 4521 4522

	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];
			}

4523 4524
			/* we treat the high watermark as reserved pages. */
			max += high_wmark_pages(zone);
4525 4526 4527 4528 4529 4530 4531 4532 4533

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

L
Linus Torvalds 已提交
4534 4535 4536 4537 4538 4539 4540 4541 4542
/*
 * 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;
4543
	enum zone_type j, idx;
L
Linus Torvalds 已提交
4544

4545
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
4546 4547 4548 4549 4550 4551
		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;

4552 4553
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
4554 4555
				struct zone *lower_zone;

4556 4557
				idx--;

L
Linus Torvalds 已提交
4558 4559 4560 4561 4562 4563 4564 4565 4566 4567
				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;
			}
		}
	}
4568 4569 4570

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4571 4572
}

4573
/**
4574
 * setup_per_zone_wmarks - called when min_free_kbytes changes
4575
 * or when memory is hot-{added|removed}
4576
 *
4577 4578
 * 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
4579
 */
4580
void setup_per_zone_wmarks(void)
L
Linus Torvalds 已提交
4581 4582 4583 4584 4585 4586 4587 4588 4589 4590 4591 4592 4593
{
	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) {
4594 4595
		u64 tmp;

4596
		spin_lock_irqsave(&zone->lock, flags);
4597 4598
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
4599 4600
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
4601 4602 4603 4604
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
4605
			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
N
Nick Piggin 已提交
4606 4607
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
Linus Torvalds 已提交
4608 4609 4610 4611 4612 4613 4614 4615
			 */
			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;
4616
			zone->watermark[WMARK_MIN] = min_pages;
L
Linus Torvalds 已提交
4617
		} else {
N
Nick Piggin 已提交
4618 4619
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
4620 4621
			 * proportionate to the zone's size.
			 */
4622
			zone->watermark[WMARK_MIN] = tmp;
L
Linus Torvalds 已提交
4623 4624
		}

4625 4626
		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) + (tmp >> 2);
		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
4627
		setup_zone_migrate_reserve(zone);
4628
		spin_unlock_irqrestore(&zone->lock, flags);
L
Linus Torvalds 已提交
4629
	}
4630 4631 4632

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4633 4634
}

4635
/*
4636 4637 4638 4639 4640 4641 4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655
 * 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
 */
4656
void calculate_zone_inactive_ratio(struct zone *zone)
4657
{
4658
	unsigned int gb, ratio;
4659

4660 4661 4662
	/* Zone size in gigabytes */
	gb = zone->present_pages >> (30 - PAGE_SHIFT);
	if (gb)
4663
		ratio = int_sqrt(10 * gb);
4664 4665
	else
		ratio = 1;
4666

4667 4668
	zone->inactive_ratio = ratio;
}
4669

4670 4671 4672 4673 4674 4675
static void __init setup_per_zone_inactive_ratio(void)
{
	struct zone *zone;

	for_each_zone(zone)
		calculate_zone_inactive_ratio(zone);
4676 4677
}

L
Linus Torvalds 已提交
4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689 4690 4691 4692 4693 4694 4695 4696 4697 4698 4699 4700 4701
/*
 * 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
 */
4702
static int __init init_per_zone_wmark_min(void)
L
Linus Torvalds 已提交
4703 4704 4705 4706 4707 4708 4709 4710 4711 4712
{
	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;
4713
	setup_per_zone_wmarks();
L
Linus Torvalds 已提交
4714
	setup_per_zone_lowmem_reserve();
4715
	setup_per_zone_inactive_ratio();
L
Linus Torvalds 已提交
4716 4717
	return 0;
}
4718
module_init(init_per_zone_wmark_min)
L
Linus Torvalds 已提交
4719 4720 4721 4722 4723 4724 4725

/*
 * 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, 
4726
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
4727
{
4728
	proc_dointvec(table, write, buffer, length, ppos);
4729
	if (write)
4730
		setup_per_zone_wmarks();
L
Linus Torvalds 已提交
4731 4732 4733
	return 0;
}

4734 4735
#ifdef CONFIG_NUMA
int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
4736
	void __user *buffer, size_t *length, loff_t *ppos)
4737 4738 4739 4740
{
	struct zone *zone;
	int rc;

4741
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
4742 4743 4744 4745
	if (rc)
		return rc;

	for_each_zone(zone)
4746
		zone->min_unmapped_pages = (zone->present_pages *
4747 4748 4749
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
4750 4751

int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
4752
	void __user *buffer, size_t *length, loff_t *ppos)
4753 4754 4755 4756
{
	struct zone *zone;
	int rc;

4757
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
4758 4759 4760 4761 4762 4763 4764 4765
	if (rc)
		return rc;

	for_each_zone(zone)
		zone->min_slab_pages = (zone->present_pages *
				sysctl_min_slab_ratio) / 100;
	return 0;
}
4766 4767
#endif

L
Linus Torvalds 已提交
4768 4769 4770 4771 4772 4773
/*
 * 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
4774
 * minimum watermarks. The lowmem reserve ratio can only make sense
L
Linus Torvalds 已提交
4775 4776 4777
 * if in function of the boot time zone sizes.
 */
int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
4778
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
4779
{
4780
	proc_dointvec_minmax(table, write, buffer, length, ppos);
L
Linus Torvalds 已提交
4781 4782 4783 4784
	setup_per_zone_lowmem_reserve();
	return 0;
}

4785 4786 4787 4788 4789 4790 4791
/*
 * 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,
4792
	void __user *buffer, size_t *length, loff_t *ppos)
4793 4794 4795 4796 4797
{
	struct zone *zone;
	unsigned int cpu;
	int ret;

4798
	ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
4799 4800
	if (!write || (ret == -EINVAL))
		return ret;
4801
	for_each_populated_zone(zone) {
4802 4803 4804 4805 4806 4807 4808 4809 4810
		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;
}

4811
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
4812 4813 4814 4815 4816 4817 4818 4819 4820 4821 4822 4823 4824 4825 4826 4827 4828 4829 4830 4831 4832 4833 4834 4835 4836 4837 4838 4839 4840 4841 4842 4843 4844 4845

#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
4846
		numentries = nr_kernel_pages;
L
Linus Torvalds 已提交
4847 4848 4849 4850 4851 4852 4853 4854 4855
		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);
4856 4857

		/* Make sure we've got at least a 0-order allocation.. */
4858 4859 4860 4861 4862 4863 4864 4865
		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))
4866
			numentries = PAGE_SIZE / bucketsize;
L
Linus Torvalds 已提交
4867
	}
4868
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
4869 4870 4871 4872 4873 4874 4875 4876 4877 4878

	/* 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;

4879
	log2qty = ilog2(numentries);
L
Linus Torvalds 已提交
4880 4881 4882 4883

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
4884
			table = alloc_bootmem_nopanic(size);
L
Linus Torvalds 已提交
4885 4886 4887
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
4888 4889
			/*
			 * If bucketsize is not a power-of-two, we may free
4890 4891
			 * some pages at the end of hash table which
			 * alloc_pages_exact() automatically does
4892
			 */
4893
			if (get_order(size) < MAX_ORDER) {
4894
				table = alloc_pages_exact(size, GFP_ATOMIC);
4895 4896
				kmemleak_alloc(table, size, 1, GFP_ATOMIC);
			}
L
Linus Torvalds 已提交
4897 4898 4899 4900 4901 4902
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

4903
	printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
L
Linus Torvalds 已提交
4904 4905
	       tablename,
	       (1U << log2qty),
4906
	       ilog2(size) - PAGE_SHIFT,
L
Linus Torvalds 已提交
4907 4908 4909 4910 4911 4912 4913 4914 4915
	       size);

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

	return table;
}
4916

4917 4918 4919 4920 4921 4922 4923 4924 4925 4926 4927 4928 4929 4930 4931
/* 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);
4932
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4933 4934
#else
	pfn = pfn - zone->zone_start_pfn;
4935
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4936 4937 4938 4939
#endif /* CONFIG_SPARSEMEM */
}

/**
4940
 * get_pageblock_flags_group - Return the requested group of flags for the 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 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;
4963

4964 4965 4966 4967
	return flags;
}

/**
4968
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4969 4970 4971 4972 4973 4974 4975 4976 4977 4978 4979 4980 4981 4982 4983 4984 4985
 * @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);
4986 4987
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
4988 4989 4990 4991 4992 4993 4994

	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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/*
 * 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;
5007
	int zone_idx;
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	zone = page_zone(page);
5010
	zone_idx = zone_idx(zone);
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	spin_lock_irqsave(&zone->lock, flags);
	/*
	 * In future, more migrate types will be able to be isolation target.
	 */
5015 5016
	if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE &&
	    zone_idx != ZONE_MOVABLE)
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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)
5024
		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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#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