page_alloc.c 133.8 KB
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/*
 *  linux/mm/page_alloc.c
 *
 *  Manages the free list, the system allocates free pages here.
 *  Note that kmalloc() lives in slab.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *  Swap reorganised 29.12.95, Stephen Tweedie
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *  Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
 *  Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
 *  Zone balancing, Kanoj Sarcar, SGI, Jan 2000
 *  Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
 *          (lots of bits borrowed from Ingo Molnar & Andrew Morton)
 */

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

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

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

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

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

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int min_free_kbytes = 1024;

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

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  static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS];
  static int __meminitdata nr_nodemap_entries;
  static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
  static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
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  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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#ifdef CONFIG_DEBUG_VM
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static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
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{
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	int ret = 0;
	unsigned seq;
	unsigned long pfn = page_to_pfn(page);
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	do {
		seq = zone_span_seqbegin(zone);
		if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
			ret = 1;
		else if (pfn < zone->zone_start_pfn)
			ret = 1;
	} while (zone_span_seqretry(zone, seq));

	return ret;
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}

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

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

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

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static void bad_page(struct page *page)
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{
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	static unsigned long resume;
	static unsigned long nr_shown;
	static unsigned long nr_unshown;

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

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

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

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

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void prep_compound_page(struct page *page, unsigned long order)
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{
	int i;
	int nr_pages = 1 << order;

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

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

#ifdef CONFIG_HUGETLBFS
void prep_compound_gigantic_page(struct page *page, unsigned long order)
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{
	int i;
	int nr_pages = 1 << order;
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	struct page *p = page + 1;
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	set_compound_page_dtor(page, free_compound_page);
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	set_compound_order(page, order);
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	__SetPageHead(page);
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	for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
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		__SetPageTail(p);
		p->first_page = page;
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	}
}
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#endif
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static int destroy_compound_page(struct page *page, unsigned long order)
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{
	int i;
	int nr_pages = 1 << order;
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	int bad = 0;
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	if (unlikely(compound_order(page) != order) ||
	    unlikely(!PageHead(page))) {
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		bad_page(page);
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		bad++;
	}
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	__ClearPageHead(page);
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	for (i = 1; i < nr_pages; i++) {
		struct page *p = page + i;
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		if (unlikely(!PageTail(p) || (p->first_page != page))) {
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			bad_page(page);
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			bad++;
		}
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		__ClearPageTail(p);
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	}
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	return bad;
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}

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

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

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

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

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

	return page + (buddy_idx - page_idx);
}

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

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

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

	if (PageBuddy(buddy) && page_order(buddy) == order) {
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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)
{
	__ClearPageMlocked(page);
	__dec_zone_page_state(page, NR_MLOCK);
	__count_vm_event(UNEVICTABLE_MLOCKFREED);
}
#else
static void free_page_mlock(struct page *page) { }
#endif

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static inline int free_pages_check(struct page *page)
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{
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	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
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		(atomic_read(&page->_count) != 0) |
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		(page->flags & PAGE_FLAGS_CHECK_AT_FREE))) {
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		bad_page(page);
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		return 1;
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	}
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	if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
		page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
	return 0;
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}

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

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		VM_BUG_ON(list_empty(list));
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		page = list_entry(list->prev, struct page, lru);
N
Nick Piggin 已提交
550
		/* have to delete it as __free_one_page list manipulates */
L
Linus Torvalds 已提交
551
		list_del(&page->lru);
552
		__free_one_page(page, zone, order, page_private(page));
L
Linus Torvalds 已提交
553
	}
N
Nick Piggin 已提交
554
	spin_unlock(&zone->lock);
L
Linus Torvalds 已提交
555 556
}

557 558
static void free_one_page(struct zone *zone, struct page *page, int order,
				int migratetype)
L
Linus Torvalds 已提交
559
{
560
	spin_lock(&zone->lock);
561
	zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
562
	zone->pages_scanned = 0;
563 564

	__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
565
	__free_one_page(page, zone, order, migratetype);
566
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
567 568 569 570 571
}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
L
Linus Torvalds 已提交
572
	int i;
573
	int bad = 0;
574
	int clearMlocked = PageMlocked(page);
L
Linus Torvalds 已提交
575 576

	for (i = 0 ; i < (1 << order) ; ++i)
577 578
		bad += free_pages_check(page + i);
	if (bad)
579 580
		return;

581
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
582
		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
583 584 585
		debug_check_no_obj_freed(page_address(page),
					   PAGE_SIZE << order);
	}
N
Nick Piggin 已提交
586
	arch_free_page(page, order);
N
Nick Piggin 已提交
587
	kernel_map_pages(page, 1 << order, 0);
N
Nick Piggin 已提交
588

N
Nick Piggin 已提交
589
	local_irq_save(flags);
590 591
	if (unlikely(clearMlocked))
		free_page_mlock(page);
592
	__count_vm_events(PGFREE, 1 << order);
593 594
	free_one_page(page_zone(page), page, order,
					get_pageblock_migratetype(page));
N
Nick Piggin 已提交
595
	local_irq_restore(flags);
L
Linus Torvalds 已提交
596 597
}

598 599 600
/*
 * permit the bootmem allocator to evade page validation on high-order frees
 */
601
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
602 603 604 605
{
	if (order == 0) {
		__ClearPageReserved(page);
		set_page_count(page, 0);
606
		set_page_refcounted(page);
N
Nick Piggin 已提交
607
		__free_page(page);
608 609 610
	} else {
		int loop;

N
Nick Piggin 已提交
611
		prefetchw(page);
612 613 614
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

N
Nick Piggin 已提交
615 616
			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
617 618 619 620
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

621
		set_page_refcounted(page);
N
Nick Piggin 已提交
622
		__free_pages(page, order);
623 624 625
	}
}

L
Linus Torvalds 已提交
626 627 628 629 630 631 632 633 634 635 636 637 638 639 640

/*
 * 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
641
static inline void expand(struct zone *zone, struct page *page,
642 643
	int low, int high, struct free_area *area,
	int migratetype)
L
Linus Torvalds 已提交
644 645 646 647 648 649 650
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
651
		VM_BUG_ON(bad_range(zone, &page[size]));
652
		list_add(&page[size].lru, &area->free_list[migratetype]);
L
Linus Torvalds 已提交
653 654 655 656 657 658 659 660
		area->nr_free++;
		set_page_order(&page[size], high);
	}
}

/*
 * This page is about to be returned from the page allocator
 */
N
Nick Piggin 已提交
661
static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
L
Linus Torvalds 已提交
662
{
N
Nick Piggin 已提交
663 664
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
665
		(atomic_read(&page->_count) != 0)  |
666
		(page->flags & PAGE_FLAGS_CHECK_AT_PREP))) {
N
Nick Piggin 已提交
667
		bad_page(page);
668
		return 1;
669
	}
670

H
Hugh Dickins 已提交
671
	set_page_private(page, 0);
672
	set_page_refcounted(page);
N
Nick Piggin 已提交
673 674

	arch_alloc_page(page, order);
L
Linus Torvalds 已提交
675
	kernel_map_pages(page, 1 << order, 1);
N
Nick Piggin 已提交
676 677 678 679 680 681 682

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

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

683
	return 0;
L
Linus Torvalds 已提交
684 685
}

686 687 688 689
/*
 * Go through the free lists for the given migratetype and remove
 * the smallest available page from the freelists
 */
690 691
static inline
struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716
						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;
}


717 718 719 720 721
/*
 * 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] = {
722 723 724 725
	[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 */
726 727
};

728 729
/*
 * Move the free pages in a range to the free lists of the requested type.
730
 * Note that start_page and end_pages are not aligned on a pageblock
731 732
 * boundary. If alignment is required, use move_freepages_block()
 */
A
Adrian Bunk 已提交
733 734 735
static int move_freepages(struct zone *zone,
			  struct page *start_page, struct page *end_page,
			  int migratetype)
736 737 738
{
	struct page *page;
	unsigned long order;
739
	int pages_moved = 0;
740 741 742 743 744 745 746

#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
747
	 * grouping pages by mobility
748 749 750 751 752
	 */
	BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif

	for (page = start_page; page <= end_page;) {
753 754 755
		/* Make sure we are not inadvertently changing nodes */
		VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));

756 757 758 759 760 761 762 763 764 765 766 767 768 769 770
		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;
771
		pages_moved += 1 << order;
772 773
	}

774
	return pages_moved;
775 776
}

A
Adrian Bunk 已提交
777 778
static int move_freepages_block(struct zone *zone, struct page *page,
				int migratetype)
779 780 781 782 783
{
	unsigned long start_pfn, end_pfn;
	struct page *start_page, *end_page;

	start_pfn = page_to_pfn(page);
784
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
785
	start_page = pfn_to_page(start_pfn);
786 787
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
788 789 790 791 792 793 794 795 796 797

	/* 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);
}

798
/* Remove an element from the buddy allocator from the fallback list */
799 800
static inline struct page *
__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
801 802 803 804 805 806 807 808 809 810 811 812
{
	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];

813 814 815
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
				continue;
M
Mel Gorman 已提交
816

817 818 819 820 821 822 823 824 825
			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--;

			/*
826
			 * If breaking a large block of pages, move all free
827 828 829
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
			 * agressive about taking ownership of free pages
830
			 */
831
			if (unlikely(current_order >= (pageblock_order >> 1)) ||
832 833 834 835 836 837
					start_migratetype == MIGRATE_RECLAIMABLE) {
				unsigned long pages;
				pages = move_freepages_block(zone, page,
								start_migratetype);

				/* Claim the whole block if over half of it is free */
838
				if (pages >= (1 << (pageblock_order-1)))
839 840 841
					set_pageblock_migratetype(page,
								start_migratetype);

842
				migratetype = start_migratetype;
843
			}
844 845 846 847 848

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

849
			if (current_order == pageblock_order)
850 851 852 853 854 855 856 857
				set_pageblock_migratetype(page,
							start_migratetype);

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

858
	return NULL;
859 860
}

861
/*
L
Linus Torvalds 已提交
862 863 864
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
865 866
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
L
Linus Torvalds 已提交
867 868 869
{
	struct page *page;

870
retry_reserve:
871
	page = __rmqueue_smallest(zone, order, migratetype);
872

873
	if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
874
		page = __rmqueue_fallback(zone, order, migratetype);
875

876 877 878 879 880 881 882 883 884 885 886
		/*
		 * 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;
		}
	}

887
	return page;
L
Linus Torvalds 已提交
888 889 890 891 892 893 894 895
}

/* 
 * 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, 
896 897
			unsigned long count, struct list_head *list,
			int migratetype)
L
Linus Torvalds 已提交
898 899 900
{
	int i;
	
N
Nick Piggin 已提交
901
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
902
	for (i = 0; i < count; ++i) {
903
		struct page *page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
904
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
905
			break;
906 907 908 909 910 911 912 913 914 915

		/*
		 * 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.
		 */
916 917
		list_add(&page->lru, list);
		set_page_private(page, migratetype);
918
		list = &page->lru;
L
Linus Torvalds 已提交
919
	}
920
	__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
N
Nick Piggin 已提交
921
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
922
	return i;
L
Linus Torvalds 已提交
923 924
}

925
#ifdef CONFIG_NUMA
926
/*
927 928 929 930
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
931 932
 * Note that this function must be called with the thread pinned to
 * a single processor.
933
 */
934
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
935 936
{
	unsigned long flags;
937
	int to_drain;
938

939 940 941 942 943 944 945 946
	local_irq_save(flags);
	if (pcp->count >= pcp->batch)
		to_drain = pcp->batch;
	else
		to_drain = pcp->count;
	free_pages_bulk(zone, to_drain, &pcp->list, 0);
	pcp->count -= to_drain;
	local_irq_restore(flags);
947 948 949
}
#endif

950 951 952 953 954 955 956 957
/*
 * 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
958
{
N
Nick Piggin 已提交
959
	unsigned long flags;
L
Linus Torvalds 已提交
960 961
	struct zone *zone;

962
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
963
		struct per_cpu_pageset *pset;
964
		struct per_cpu_pages *pcp;
L
Linus Torvalds 已提交
965

966
		pset = zone_pcp(zone, cpu);
967 968 969 970 971 972

		pcp = &pset->pcp;
		local_irq_save(flags);
		free_pages_bulk(zone, pcp->count, &pcp->list, 0);
		pcp->count = 0;
		local_irq_restore(flags);
L
Linus Torvalds 已提交
973 974 975
	}
}

976 977 978 979 980 981 982 983 984 985 986 987 988
/*
 * 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)
{
989
	on_each_cpu(drain_local_pages, NULL, 1);
990 991
}

992
#ifdef CONFIG_HIBERNATION
L
Linus Torvalds 已提交
993 994 995

void mark_free_pages(struct zone *zone)
{
996 997
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
998
	int order, t;
L
Linus Torvalds 已提交
999 1000 1001 1002 1003 1004
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
1005 1006 1007 1008 1009 1010

	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);

1011 1012
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
1013
		}
L
Linus Torvalds 已提交
1014

1015 1016
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
1017
			unsigned long i;
L
Linus Torvalds 已提交
1018

1019 1020
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
1021
				swsusp_set_page_free(pfn_to_page(pfn + i));
1022
		}
1023
	}
L
Linus Torvalds 已提交
1024 1025
	spin_unlock_irqrestore(&zone->lock, flags);
}
1026
#endif /* CONFIG_PM */
L
Linus Torvalds 已提交
1027 1028 1029 1030

/*
 * Free a 0-order page
 */
H
Harvey Harrison 已提交
1031
static void free_hot_cold_page(struct page *page, int cold)
L
Linus Torvalds 已提交
1032 1033 1034 1035
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;
1036
	int clearMlocked = PageMlocked(page);
L
Linus Torvalds 已提交
1037 1038 1039

	if (PageAnon(page))
		page->mapping = NULL;
N
Nick Piggin 已提交
1040
	if (free_pages_check(page))
1041 1042
		return;

1043
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
1044
		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
1045 1046
		debug_check_no_obj_freed(page_address(page), PAGE_SIZE);
	}
N
Nick Piggin 已提交
1047
	arch_free_page(page, 0);
1048 1049
	kernel_map_pages(page, 1, 0);

1050
	pcp = &zone_pcp(zone, get_cpu())->pcp;
1051
	set_page_private(page, get_pageblock_migratetype(page));
L
Linus Torvalds 已提交
1052
	local_irq_save(flags);
1053 1054
	if (unlikely(clearMlocked))
		free_page_mlock(page);
1055
	__count_vm_event(PGFREE);
1056

1057 1058 1059 1060
	if (cold)
		list_add_tail(&page->lru, &pcp->list);
	else
		list_add(&page->lru, &pcp->list);
L
Linus Torvalds 已提交
1061
	pcp->count++;
N
Nick Piggin 已提交
1062 1063 1064 1065
	if (pcp->count >= pcp->high) {
		free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
		pcp->count -= pcp->batch;
	}
L
Linus Torvalds 已提交
1066 1067 1068 1069
	local_irq_restore(flags);
	put_cpu();
}

H
Harvey Harrison 已提交
1070
void free_hot_page(struct page *page)
L
Linus Torvalds 已提交
1071 1072 1073 1074
{
	free_hot_cold_page(page, 0);
}
	
H
Harvey Harrison 已提交
1075
void free_cold_page(struct page *page)
L
Linus Torvalds 已提交
1076 1077 1078 1079
{
	free_hot_cold_page(page, 1);
}

N
Nick Piggin 已提交
1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091
/*
 * 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
1092 1093
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1094 1095
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
1096 1097
}

L
Linus Torvalds 已提交
1098 1099 1100 1101 1102
/*
 * 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.
 */
1103 1104
static inline
struct page *buffered_rmqueue(struct zone *preferred_zone,
1105 1106
			struct zone *zone, int order, gfp_t gfp_flags,
			int migratetype)
L
Linus Torvalds 已提交
1107 1108
{
	unsigned long flags;
1109
	struct page *page;
L
Linus Torvalds 已提交
1110
	int cold = !!(gfp_flags & __GFP_COLD);
N
Nick Piggin 已提交
1111
	int cpu;
L
Linus Torvalds 已提交
1112

1113
again:
N
Nick Piggin 已提交
1114
	cpu  = get_cpu();
N
Nick Piggin 已提交
1115
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1116 1117
		struct per_cpu_pages *pcp;

1118
		pcp = &zone_pcp(zone, cpu)->pcp;
L
Linus Torvalds 已提交
1119
		local_irq_save(flags);
N
Nick Piggin 已提交
1120
		if (!pcp->count) {
1121
			pcp->count = rmqueue_bulk(zone, 0,
1122
					pcp->batch, &pcp->list, migratetype);
N
Nick Piggin 已提交
1123 1124
			if (unlikely(!pcp->count))
				goto failed;
L
Linus Torvalds 已提交
1125
		}
1126

1127
		/* Find a page of the appropriate migrate type */
1128 1129 1130 1131 1132 1133 1134 1135 1136
		if (cold) {
			list_for_each_entry_reverse(page, &pcp->list, lru)
				if (page_private(page) == migratetype)
					break;
		} else {
			list_for_each_entry(page, &pcp->list, lru)
				if (page_private(page) == migratetype)
					break;
		}
1137

1138 1139
		/* Allocate more to the pcp list if necessary */
		if (unlikely(&page->lru == &pcp->list)) {
1140 1141 1142 1143
			pcp->count += rmqueue_bulk(zone, 0,
					pcp->batch, &pcp->list, migratetype);
			page = list_entry(pcp->list.next, struct page, lru);
		}
1144 1145 1146

		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1147
	} else {
L
Linus Torvalds 已提交
1148
		spin_lock_irqsave(&zone->lock, flags);
1149
		page = __rmqueue(zone, order, migratetype);
1150
		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
N
Nick Piggin 已提交
1151 1152 1153
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
L
Linus Torvalds 已提交
1154 1155
	}

1156
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1157
	zone_statistics(preferred_zone, zone);
N
Nick Piggin 已提交
1158 1159
	local_irq_restore(flags);
	put_cpu();
L
Linus Torvalds 已提交
1160

N
Nick Piggin 已提交
1161
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1162
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1163
		goto again;
L
Linus Torvalds 已提交
1164
	return page;
N
Nick Piggin 已提交
1165 1166 1167 1168 1169

failed:
	local_irq_restore(flags);
	put_cpu();
	return NULL;
L
Linus Torvalds 已提交
1170 1171
}

1172 1173 1174 1175 1176 1177 1178 1179 1180
/* 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)

1181 1182 1183
#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
1184

1185 1186 1187 1188 1189 1190 1191
#ifdef CONFIG_FAIL_PAGE_ALLOC

static struct fail_page_alloc_attr {
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1192
	u32 min_order;
1193 1194 1195 1196 1197

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

	struct dentry *ignore_gfp_highmem_file;
	struct dentry *ignore_gfp_wait_file;
1198
	struct dentry *min_order_file;
1199 1200 1201 1202 1203

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1204 1205
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1206
	.min_order = 1,
1207 1208 1209 1210 1211 1212 1213 1214 1215 1216
};

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)
{
1217 1218
	if (order < fail_page_alloc.min_order)
		return 0;
1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249
	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);
1250 1251 1252
	fail_page_alloc.min_order_file =
		debugfs_create_u32("min-order", mode, dir,
				   &fail_page_alloc.min_order);
1253 1254

	if (!fail_page_alloc.ignore_gfp_wait_file ||
1255 1256
            !fail_page_alloc.ignore_gfp_highmem_file ||
            !fail_page_alloc.min_order_file) {
1257 1258 1259
		err = -ENOMEM;
		debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
		debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1260
		debugfs_remove(fail_page_alloc.min_order_file);
1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279
		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
1280 1281 1282 1283 1284
/*
 * 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
1285
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
1286 1287
{
	/* free_pages my go negative - that's OK */
1288 1289
	long min = mark;
	long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
L
Linus Torvalds 已提交
1290 1291
	int o;

R
Rohit Seth 已提交
1292
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1293
		min -= min / 2;
R
Rohit Seth 已提交
1294
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311
		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;
}

1312 1313 1314 1315 1316 1317
#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
1318
 * that have to skip over a lot of full or unallowed zones.
1319 1320 1321
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1322
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343
 *
 * 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
1344
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1345 1346 1347 1348 1349 1350
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1351
					&node_states[N_HIGH_MEMORY];
1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376
	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.
 */
1377
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1378 1379 1380 1381 1382 1383 1384 1385 1386 1387
						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;

1388
	i = z - zonelist->_zonerefs;
1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399
	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.
 */
1400
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1401 1402 1403 1404 1405 1406 1407 1408
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

1409
	i = z - zonelist->_zonerefs;
1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

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

1421
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1422 1423 1424 1425 1426
				nodemask_t *allowednodes)
{
	return 1;
}

1427
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1428 1429 1430 1431
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1432
/*
1433
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1434 1435 1436
 * a page.
 */
static struct page *
1437
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1438
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1439
		struct zone *preferred_zone, int migratetype)
M
Martin Hicks 已提交
1440
{
1441
	struct zoneref *z;
R
Rohit Seth 已提交
1442
	struct page *page = NULL;
1443
	int classzone_idx;
1444
	struct zone *zone;
1445 1446 1447
	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 */
1448

1449 1450 1451
	if (WARN_ON_ONCE(order >= MAX_ORDER))
		return NULL;

1452
	classzone_idx = zone_idx(preferred_zone);
1453
zonelist_scan:
R
Rohit Seth 已提交
1454
	/*
1455
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1456 1457
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1458 1459
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1460 1461 1462
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1463
		if ((alloc_flags & ALLOC_CPUSET) &&
1464
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1465
				goto try_next_zone;
R
Rohit Seth 已提交
1466

1467
		BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
R
Rohit Seth 已提交
1468
		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1469
			unsigned long mark;
1470
			mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1471 1472
			if (!zone_watermark_ok(zone, order, mark,
				    classzone_idx, alloc_flags)) {
1473
				if (!zone_reclaim_mode ||
1474
				    !zone_reclaim(zone, gfp_mask, order))
1475
					goto this_zone_full;
1476
			}
R
Rohit Seth 已提交
1477 1478
		}

1479 1480
		page = buffered_rmqueue(preferred_zone, zone, order,
						gfp_mask, migratetype);
1481
		if (page)
R
Rohit Seth 已提交
1482
			break;
1483 1484 1485 1486
this_zone_full:
		if (NUMA_BUILD)
			zlc_mark_zone_full(zonelist, z);
try_next_zone:
1487
		if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1488 1489 1490 1491
			/*
			 * we do zlc_setup after the first zone is tried but only
			 * if there are multiple nodes make it worthwhile
			 */
1492 1493 1494 1495
			allowednodes = zlc_setup(zonelist, alloc_flags);
			zlc_active = 1;
			did_zlc_setup = 1;
		}
1496
	}
1497 1498 1499 1500 1501 1502

	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
1503
	return page;
M
Martin Hicks 已提交
1504 1505
}

1506 1507 1508
static inline int
should_alloc_retry(gfp_t gfp_mask, unsigned int order,
				unsigned long pages_reclaimed)
L
Linus Torvalds 已提交
1509
{
1510 1511 1512
	/* Do not loop if specifically requested */
	if (gfp_mask & __GFP_NORETRY)
		return 0;
L
Linus Torvalds 已提交
1513

1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530
	/*
	 * 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;
1531

1532 1533 1534 1535 1536 1537
	/*
	 * 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
1538

1539 1540
	return 0;
}
1541

1542 1543 1544
static inline struct page *
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1545 1546
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1547 1548 1549 1550 1551 1552
{
	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
1553 1554
		return NULL;
	}
1555

1556 1557 1558 1559 1560 1561 1562
	/*
	 * 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,
1563
		ALLOC_WMARK_HIGH|ALLOC_CPUSET,
1564
		preferred_zone, migratetype);
R
Rohit Seth 已提交
1565
	if (page)
1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583
		goto out;

	/* The OOM killer will not help higher order allocs */
	if (order > PAGE_ALLOC_COSTLY_ORDER)
		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,
1584
	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1585
	int migratetype, unsigned long *did_some_progress)
1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616
{
	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();

	/*
	 * The task's cpuset might have expanded its set of allowable nodes
	 */
	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,
1617
					zonelist, high_zoneidx,
1618 1619
					alloc_flags, preferred_zone,
					migratetype);
1620 1621 1622 1623 1624 1625 1626 1627 1628 1629
	return page;
}

/*
 * This is called in the allocator slow-path if the allocation request is of
 * sufficient urgency to ignore watermarks and take other desperate measures
 */
static inline struct page *
__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1630 1631
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1632 1633 1634 1635 1636
{
	struct page *page;

	do {
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1637
			zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
1638
			preferred_zone, migratetype);
1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657

		if (!page && gfp_mask & __GFP_NOFAIL)
			congestion_wait(WRITE, HZ/50);
	} 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)
{
	struct zoneref *z;
	struct zone *zone;

	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
		wakeup_kswapd(zone, order);
}

1658 1659 1660 1661 1662 1663 1664
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;

1665 1666 1667
	/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
	BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH);

1668 1669 1670 1671 1672 1673
	/*
	 * 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).
	 */
1674
	alloc_flags |= (gfp_mask & __GFP_HIGH);
1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695

	if (!wait) {
		alloc_flags |= ALLOC_HARDER;
		/*
		 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
		 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
		 */
		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;
	}

	return alloc_flags;
}

1696 1697 1698
static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1699 1700
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1701 1702 1703 1704 1705 1706 1707
{
	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
1708

1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719
	/*
	 * 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;

1720
	wake_all_kswapd(order, zonelist, high_zoneidx);
L
Linus Torvalds 已提交
1721

1722
	/*
R
Rohit Seth 已提交
1723 1724 1725
	 * 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.
1726
	 */
1727
	alloc_flags = gfp_to_alloc_flags(gfp_mask);
L
Linus Torvalds 已提交
1728

1729
restart:
1730
	/* This is the last chance, in general, before the goto nopage. */
1731
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1732 1733
			high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
			preferred_zone, migratetype);
R
Rohit Seth 已提交
1734 1735
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1736

1737
rebalance:
1738
	/* Allocate without watermarks if the context allows */
1739 1740 1741 1742 1743 1744
	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
1745 1746 1747 1748 1749 1750
	}

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

1751 1752 1753 1754
	/* Avoid recursion of direct reclaim */
	if (p->flags & PF_MEMALLOC)
		goto nopage;

1755 1756 1757 1758
	/* Try direct reclaim and then allocating */
	page = __alloc_pages_direct_reclaim(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
1759
					alloc_flags, preferred_zone,
1760
					migratetype, &did_some_progress);
1761 1762
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1763

1764 1765 1766 1767 1768 1769 1770 1771
	/*
	 * If we failed to make any progress reclaiming, then we are
	 * running out of options and have to consider going OOM
	 */
	if (!did_some_progress) {
		if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
			page = __alloc_pages_may_oom(gfp_mask, order,
					zonelist, high_zoneidx,
1772 1773
					nodemask, preferred_zone,
					migratetype);
1774 1775
			if (page)
				goto got_pg;
L
Linus Torvalds 已提交
1776

1777 1778 1779 1780 1781 1782 1783
			/*
			 * The OOM killer does not trigger for high-order allocations
			 * but if no progress is being made, there are no other
			 * options and retrying is unlikely to help
			 */
			if (order > PAGE_ALLOC_COSTLY_ORDER)
				goto nopage;
1784

1785 1786
			goto restart;
		}
L
Linus Torvalds 已提交
1787 1788
	}

1789
	/* Check if we should retry the allocation */
1790
	pages_reclaimed += did_some_progress;
1791 1792
	if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
		/* Wait for some write requests to complete then retry */
1793
		congestion_wait(WRITE, HZ/50);
L
Linus Torvalds 已提交
1794 1795 1796 1797 1798 1799 1800 1801 1802
		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
1803
		show_mem();
L
Linus Torvalds 已提交
1804 1805 1806
	}
got_pg:
	return page;
1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817

}

/*
 * 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);
1818
	struct zone *preferred_zone;
1819
	struct page *page;
1820
	int migratetype = allocflags_to_migratetype(gfp_mask);
1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836

	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;

1837 1838 1839 1840 1841 1842
	/* 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 */
1843
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
1844
			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
1845
			preferred_zone, migratetype);
1846 1847
	if (unlikely(!page))
		page = __alloc_pages_slowpath(gfp_mask, order,
1848
				zonelist, high_zoneidx, nodemask,
1849
				preferred_zone, migratetype);
1850 1851

	return page;
L
Linus Torvalds 已提交
1852
}
1853
EXPORT_SYMBOL(__alloc_pages_nodemask);
L
Linus Torvalds 已提交
1854 1855 1856 1857

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
1858
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
1859 1860 1861 1862 1863 1864 1865 1866 1867 1868
{
	struct page * page;
	page = alloc_pages(gfp_mask, order);
	if (!page)
		return 0;
	return (unsigned long) page_address(page);
}

EXPORT_SYMBOL(__get_free_pages);

H
Harvey Harrison 已提交
1869
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
1870 1871 1872 1873 1874 1875 1876
{
	struct page * page;

	/*
	 * get_zeroed_page() returns a 32-bit address, which cannot represent
	 * a highmem page
	 */
N
Nick Piggin 已提交
1877
	VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
L
Linus Torvalds 已提交
1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894

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

EXPORT_SYMBOL(get_zeroed_page);

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

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

H
Harvey Harrison 已提交
1895
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
1896
{
N
Nick Piggin 已提交
1897
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
1898 1899 1900 1901 1902 1903 1904 1905 1906
		if (order == 0)
			free_hot_page(page);
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
1907
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
1908 1909
{
	if (addr != 0) {
N
Nick Piggin 已提交
1910
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
1911 1912 1913 1914 1915 1916
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969
/**
 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
 * @size: the number of bytes to allocate
 * @gfp_mask: GFP flags for the allocation
 *
 * This function is similar to alloc_pages(), except that it allocates the
 * minimum number of pages to satisfy the request.  alloc_pages() can only
 * allocate memory in power-of-two pages.
 *
 * This function is also limited by MAX_ORDER.
 *
 * Memory allocated by this function must be released by free_pages_exact().
 */
void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
{
	unsigned int order = get_order(size);
	unsigned long addr;

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

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

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

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

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

L
Linus Torvalds 已提交
1970 1971
static unsigned int nr_free_zone_pages(int offset)
{
1972
	struct zoneref *z;
1973 1974
	struct zone *zone;

1975
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
1976 1977
	unsigned int sum = 0;

1978
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
1979

1980
	for_each_zone_zonelist(zone, z, zonelist, offset) {
1981
		unsigned long size = zone->present_pages;
1982
		unsigned long high = high_wmark_pages(zone);
1983 1984
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
1985 1986 1987 1988 1989 1990 1991 1992 1993 1994
	}

	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
1995
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
1996
}
1997
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
1998 1999 2000 2001 2002 2003

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
2004
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
2005
}
2006 2007

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
2008
{
2009
	if (NUMA_BUILD)
2010
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
2011 2012 2013 2014 2015 2016
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
2017
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031
	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;
2032
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
2033
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2034
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2035 2036
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
2037 2038 2039 2040
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053
	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)
{
2054
	int cpu;
L
Linus Torvalds 已提交
2055 2056
	struct zone *zone;

2057
	for_each_populated_zone(zone) {
2058 2059
		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
2060

2061
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
2062 2063
			struct per_cpu_pageset *pageset;

2064
			pageset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
2065

2066 2067 2068
			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
2069 2070 2071
		}
	}

L
Lee Schermerhorn 已提交
2072 2073 2074 2075 2076 2077 2078
	printk("Active_anon:%lu active_file:%lu inactive_anon:%lu\n"
		" inactive_file:%lu"
//TODO:  check/adjust line lengths
#ifdef CONFIG_UNEVICTABLE_LRU
		" unevictable:%lu"
#endif
		" dirty:%lu writeback:%lu unstable:%lu\n"
2079
		" free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
2080 2081 2082 2083
		global_page_state(NR_ACTIVE_ANON),
		global_page_state(NR_ACTIVE_FILE),
		global_page_state(NR_INACTIVE_ANON),
		global_page_state(NR_INACTIVE_FILE),
L
Lee Schermerhorn 已提交
2084 2085 2086
#ifdef CONFIG_UNEVICTABLE_LRU
		global_page_state(NR_UNEVICTABLE),
#endif
2087
		global_page_state(NR_FILE_DIRTY),
2088
		global_page_state(NR_WRITEBACK),
2089
		global_page_state(NR_UNSTABLE_NFS),
2090
		global_page_state(NR_FREE_PAGES),
2091 2092
		global_page_state(NR_SLAB_RECLAIMABLE) +
			global_page_state(NR_SLAB_UNRECLAIMABLE),
2093
		global_page_state(NR_FILE_MAPPED),
2094 2095
		global_page_state(NR_PAGETABLE),
		global_page_state(NR_BOUNCE));
L
Linus Torvalds 已提交
2096

2097
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
2098 2099 2100 2101 2102 2103 2104 2105
		int i;

		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
2106 2107 2108 2109
			" active_anon:%lukB"
			" inactive_anon:%lukB"
			" active_file:%lukB"
			" inactive_file:%lukB"
L
Lee Schermerhorn 已提交
2110 2111 2112
#ifdef CONFIG_UNEVICTABLE_LRU
			" unevictable:%lukB"
#endif
L
Linus Torvalds 已提交
2113 2114 2115 2116 2117
			" present:%lukB"
			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
2118
			K(zone_page_state(zone, NR_FREE_PAGES)),
2119 2120 2121
			K(min_wmark_pages(zone)),
			K(low_wmark_pages(zone)),
			K(high_wmark_pages(zone)),
2122 2123 2124 2125
			K(zone_page_state(zone, NR_ACTIVE_ANON)),
			K(zone_page_state(zone, NR_INACTIVE_ANON)),
			K(zone_page_state(zone, NR_ACTIVE_FILE)),
			K(zone_page_state(zone, NR_INACTIVE_FILE)),
L
Lee Schermerhorn 已提交
2126 2127 2128
#ifdef CONFIG_UNEVICTABLE_LRU
			K(zone_page_state(zone, NR_UNEVICTABLE)),
#endif
L
Linus Torvalds 已提交
2129 2130
			K(zone->present_pages),
			zone->pages_scanned,
2131
			(zone_is_all_unreclaimable(zone) ? "yes" : "no")
L
Linus Torvalds 已提交
2132 2133 2134 2135 2136 2137 2138
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

2139
	for_each_populated_zone(zone) {
2140
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
L
Linus Torvalds 已提交
2141 2142 2143 2144 2145 2146

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

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
2147 2148
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
L
Linus Torvalds 已提交
2149 2150
		}
		spin_unlock_irqrestore(&zone->lock, flags);
2151 2152
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
L
Linus Torvalds 已提交
2153 2154 2155
		printk("= %lukB\n", K(total));
	}

2156 2157
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

L
Linus Torvalds 已提交
2158 2159 2160
	show_swap_cache_info();
}

2161 2162 2163 2164 2165 2166
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
{
	zoneref->zone = zone;
	zoneref->zone_idx = zone_idx(zone);
}

L
Linus Torvalds 已提交
2167 2168
/*
 * Builds allocation fallback zone lists.
2169 2170
 *
 * Add all populated zones of a node to the zonelist.
L
Linus Torvalds 已提交
2171
 */
2172 2173
static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
				int nr_zones, enum zone_type zone_type)
L
Linus Torvalds 已提交
2174
{
2175 2176
	struct zone *zone;

2177
	BUG_ON(zone_type >= MAX_NR_ZONES);
2178
	zone_type++;
2179 2180

	do {
2181
		zone_type--;
2182
		zone = pgdat->node_zones + zone_type;
2183
		if (populated_zone(zone)) {
2184 2185
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
2186
			check_highest_zone(zone_type);
L
Linus Torvalds 已提交
2187
		}
2188

2189
	} while (zone_type);
2190
	return nr_zones;
L
Linus Torvalds 已提交
2191 2192
}

2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213

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

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


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#ifdef CONFIG_NUMA
2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285
/* The value user specified ....changed by config */
static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
/* string for sysctl */
#define NUMA_ZONELIST_ORDER_LEN	16
char numa_zonelist_order[16] = "default";

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

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

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

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

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


2286
#define MAX_NODE_LOAD (nr_online_nodes)
2287 2288
static int node_load[MAX_NUMNODES];

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/**
2290
 * find_next_best_node - find the next node that should appear in a given node's fallback list
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2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302
 * @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.
 */
2303
static int find_next_best_node(int node, nodemask_t *used_node_mask)
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{
2305
	int n, val;
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	int min_val = INT_MAX;
	int best_node = -1;
2308
	const struct cpumask *tmp = cpumask_of_node(0);
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2310 2311 2312 2313 2314
	/* Use the local node if we haven't already */
	if (!node_isset(node, *used_node_mask)) {
		node_set(node, *used_node_mask);
		return node;
	}
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2316
	for_each_node_state(n, N_HIGH_MEMORY) {
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2317 2318 2319 2320 2321 2322 2323 2324

		/* 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);

2325 2326 2327
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

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		/* Give preference to headless and unused nodes */
2329 2330
		tmp = cpumask_of_node(n);
		if (!cpumask_empty(tmp))
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2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348
			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;
}

2349 2350 2351 2352 2353 2354 2355

/*
 * Build zonelists ordered by node and zones within node.
 * This results in maximum locality--normal zone overflows into local
 * DMA zone, if any--but risks exhausting DMA zone.
 */
static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
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{
2357
	int j;
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2358
	struct zonelist *zonelist;
2359

2360
	zonelist = &pgdat->node_zonelists[0];
2361
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2362 2363 2364
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
2365 2366
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2367 2368
}

2369 2370 2371 2372 2373 2374 2375 2376
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

2377 2378
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2379 2380
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2381 2382
}

2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397
/*
 * 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;

2398 2399 2400 2401 2402 2403 2404
	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)) {
2405 2406
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
2407
				check_highest_zone(zone_type);
2408 2409 2410
			}
		}
	}
2411 2412
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447
}

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.
         */
2448 2449
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480
	for_each_online_node(nid) {
		low_kmem_size = 0;
		total_size = 0;
		for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
			z = &NODE_DATA(nid)->node_zones[zone_type];
			if (populated_zone(z)) {
				if (zone_type < ZONE_NORMAL)
					low_kmem_size += z->present_pages;
				total_size += z->present_pages;
			}
		}
		if (low_kmem_size &&
		    total_size > average_size && /* ignore small node */
		    low_kmem_size > total_size * 70/100)
			return ZONELIST_ORDER_NODE;
	}
	return ZONELIST_ORDER_ZONE;
}

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

static void build_zonelists(pg_data_t *pgdat)
{
	int j, node, load;
	enum zone_type i;
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	nodemask_t used_mask;
2482 2483 2484
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
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2485 2486

	/* initialize zonelists */
2487
	for (i = 0; i < MAX_ZONELISTS; i++) {
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2488
		zonelist = pgdat->node_zonelists + i;
2489 2490
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
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2491 2492 2493 2494
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
2495
	load = nr_online_nodes;
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2496 2497
	prev_node = local_node;
	nodes_clear(used_mask);
2498 2499 2500 2501 2502

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

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	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2504 2505 2506 2507 2508 2509 2510 2511 2512
		int distance = node_distance(local_node, node);

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

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2513 2514 2515 2516 2517
		/*
		 * 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.
		 */
2518
		if (distance != node_distance(local_node, prev_node))
2519 2520
			node_load[node] = load;

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2521 2522
		prev_node = node;
		load--;
2523 2524 2525 2526 2527
		if (order == ZONELIST_ORDER_NODE)
			build_zonelists_in_node_order(pgdat, node);
		else
			node_order[j++] = node;	/* remember order */
	}
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2529 2530 2531
	if (order == ZONELIST_ORDER_ZONE) {
		/* calculate node order -- i.e., DMA last! */
		build_zonelists_in_zone_order(pgdat, j);
L
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2532
	}
2533 2534

	build_thisnode_zonelists(pgdat);
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2535 2536
}

2537
/* Construct the zonelist performance cache - see further mmzone.h */
2538
static void build_zonelist_cache(pg_data_t *pgdat)
2539
{
2540 2541
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
2542
	struct zoneref *z;
2543

2544 2545 2546
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2547 2548
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2549 2550
}

2551

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2552 2553
#else	/* CONFIG_NUMA */

2554 2555 2556 2557 2558 2559
static void set_zonelist_order(void)
{
	current_zonelist_order = ZONELIST_ORDER_ZONE;
}

static void build_zonelists(pg_data_t *pgdat)
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2560
{
2561
	int node, local_node;
2562 2563
	enum zone_type j;
	struct zonelist *zonelist;
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2564 2565 2566

	local_node = pgdat->node_id;

2567 2568
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
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2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582
	/*
	 * 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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	}
2584 2585 2586 2587 2588 2589 2590
	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);
	}

2591 2592
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
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2593 2594
}

2595
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2596
static void build_zonelist_cache(pg_data_t *pgdat)
2597
{
2598
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
2599 2600
}

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2601 2602
#endif	/* CONFIG_NUMA */

2603
/* return values int ....just for stop_machine() */
2604
static int __build_all_zonelists(void *dummy)
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2605
{
2606
	int nid;
2607 2608

	for_each_online_node(nid) {
2609 2610 2611 2612
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
2613
	}
2614 2615 2616
	return 0;
}

2617
void build_all_zonelists(void)
2618
{
2619 2620
	set_zonelist_order();

2621
	if (system_state == SYSTEM_BOOTING) {
2622
		__build_all_zonelists(NULL);
2623
		mminit_verify_zonelist();
2624 2625
		cpuset_init_current_mems_allowed();
	} else {
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Simon Arlott 已提交
2626
		/* we have to stop all cpus to guarantee there is no user
2627
		   of zonelist */
2628
		stop_machine(__build_all_zonelists, NULL, NULL);
2629 2630
		/* cpuset refresh routine should be here */
	}
2631
	vm_total_pages = nr_free_pagecache_pages();
2632 2633 2634 2635 2636 2637 2638
	/*
	 * 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
	 */
2639
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2640 2641 2642 2643 2644 2645
		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",
2646
			nr_online_nodes,
2647
			zonelist_order_name[current_zonelist_order],
2648
			page_group_by_mobility_disabled ? "off" : "on",
2649 2650 2651 2652
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
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2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667
}

/*
 * 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

2668
#ifndef CONFIG_MEMORY_HOTPLUG
2669
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
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2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686
{
	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);
}
2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709
#else
/*
 * A zone's size might be changed by hot-add, so it is not possible to determine
 * a suitable size for its wait_table.  So we use the maximum size now.
 *
 * The max wait table size = 4096 x sizeof(wait_queue_head_t).   ie:
 *
 *    i386 (preemption config)    : 4096 x 16 = 64Kbyte.
 *    ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
 *    ia64, x86-64 (preemption)   : 4096 x 24 = 96Kbyte.
 *
 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
 * or more by the traditional way. (See above).  It equals:
 *
 *    i386, x86-64, powerpc(4K page size) : =  ( 2G + 1M)byte.
 *    ia64(16K page size)                 : =  ( 8G + 4M)byte.
 *    powerpc (64K page size)             : =  (32G +16M)byte.
 */
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
{
	return 4096UL;
}
#endif
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2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722

/*
 * 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))

2723
/*
2724
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2725 2726
 * 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
2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738
 * higher will lead to a bigger reserve which will get freed as contiguous
 * blocks as reclaim kicks in
 */
static void setup_zone_migrate_reserve(struct zone *zone)
{
	unsigned long start_pfn, pfn, end_pfn;
	struct page *page;
	unsigned long reserve, block_migratetype;

	/* Get the start pfn, end pfn and the number of blocks to reserve */
	start_pfn = zone->zone_start_pfn;
	end_pfn = start_pfn + zone->spanned_pages;
2739
	reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
2740
							pageblock_order;
2741

2742
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2743 2744 2745 2746
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

2747 2748 2749 2750
		/* Watch out for overlapping nodes */
		if (page_to_nid(page) != zone_to_nid(zone))
			continue;

2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780
		/* 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
2781

L
Linus Torvalds 已提交
2782 2783 2784 2785 2786
/*
 * 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.
 */
2787
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
2788
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
2789 2790
{
	struct page *page;
A
Andy Whitcroft 已提交
2791 2792
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
2793
	struct zone *z;
L
Linus Torvalds 已提交
2794

2795 2796 2797
	if (highest_memmap_pfn < end_pfn - 1)
		highest_memmap_pfn = end_pfn - 1;

2798
	z = &NODE_DATA(nid)->node_zones[zone];
2799
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810
		/*
		 * 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
2811 2812
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
2813
		mminit_verify_page_links(page, zone, nid, pfn);
2814
		init_page_count(page);
L
Linus Torvalds 已提交
2815 2816
		reset_page_mapcount(page);
		SetPageReserved(page);
2817 2818 2819 2820 2821
		/*
		 * 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
2822 2823 2824
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
2825 2826 2827 2828 2829
		 *
		 * 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.
2830
		 */
2831 2832 2833
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
2834
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2835

L
Linus Torvalds 已提交
2836 2837 2838 2839
		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))
2840
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
2841 2842 2843 2844
#endif
	}
}

2845
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
2846
{
2847 2848 2849
	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
2850 2851 2852 2853 2854 2855
		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
2856
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
2857 2858
#endif

2859
static int zone_batchsize(struct zone *zone)
2860
{
2861
#ifdef CONFIG_MMU
2862 2863 2864 2865
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
2866
	 * size of the zone.  But no more than 1/2 of a meg.
2867 2868 2869 2870
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
2871 2872
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
2873 2874 2875 2876 2877
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
2878 2879 2880
	 * 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.
2881
	 *
2882 2883 2884 2885
	 * 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.
2886
	 */
2887
	batch = rounddown_pow_of_two(batch + batch/2) - 1;
2888

2889
	return batch;
2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906

#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
2907 2908
}

A
Adrian Bunk 已提交
2909
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
2910 2911 2912
{
	struct per_cpu_pages *pcp;

2913 2914
	memset(p, 0, sizeof(*p));

2915
	pcp = &p->pcp;
2916 2917 2918 2919 2920 2921
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
	INIT_LIST_HEAD(&pcp->list);
}

2922 2923 2924 2925 2926 2927 2928 2929 2930 2931
/*
 * 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;

2932
	pcp = &p->pcp;
2933 2934 2935 2936 2937 2938 2939
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}


2940 2941
#ifdef CONFIG_NUMA
/*
2942 2943 2944 2945 2946 2947 2948
 * 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.
2949 2950 2951 2952 2953 2954 2955 2956
 *
 * 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.
2957
 */
2958
static struct per_cpu_pageset boot_pageset[NR_CPUS];
2959 2960 2961

/*
 * Dynamically allocate memory for the
2962 2963
 * per cpu pageset array in struct zone.
 */
2964
static int __cpuinit process_zones(int cpu)
2965 2966
{
	struct zone *zone, *dzone;
2967 2968 2969
	int node = cpu_to_node(cpu);

	node_set_state(node, N_CPU);	/* this node has a cpu */
2970

2971
	for_each_populated_zone(zone) {
N
Nick Piggin 已提交
2972
		zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
2973
					 GFP_KERNEL, node);
N
Nick Piggin 已提交
2974
		if (!zone_pcp(zone, cpu))
2975 2976
			goto bad;

N
Nick Piggin 已提交
2977
		setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
2978 2979 2980 2981

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(zone_pcp(zone, cpu),
			 	(zone->present_pages / percpu_pagelist_fraction));
2982 2983 2984 2985 2986
	}

	return 0;
bad:
	for_each_zone(dzone) {
2987 2988
		if (!populated_zone(dzone))
			continue;
2989 2990
		if (dzone == zone)
			break;
N
Nick Piggin 已提交
2991 2992
		kfree(zone_pcp(dzone, cpu));
		zone_pcp(dzone, cpu) = NULL;
2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003
	}
	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);

3004 3005 3006
		/* Free per_cpu_pageset if it is slab allocated */
		if (pset != &boot_pageset[cpu])
			kfree(pset);
3007 3008 3009 3010
		zone_pcp(zone, cpu) = NULL;
	}
}

3011
static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
3012 3013 3014 3015 3016 3017 3018
		unsigned long action,
		void *hcpu)
{
	int cpu = (long)hcpu;
	int ret = NOTIFY_OK;

	switch (action) {
3019
	case CPU_UP_PREPARE:
3020
	case CPU_UP_PREPARE_FROZEN:
3021 3022 3023 3024
		if (process_zones(cpu))
			ret = NOTIFY_BAD;
		break;
	case CPU_UP_CANCELED:
3025
	case CPU_UP_CANCELED_FROZEN:
3026
	case CPU_DEAD:
3027
	case CPU_DEAD_FROZEN:
3028 3029 3030 3031
		free_zone_pagesets(cpu);
		break;
	default:
		break;
3032 3033 3034 3035
	}
	return ret;
}

3036
static struct notifier_block __cpuinitdata pageset_notifier =
3037 3038
	{ &pageset_cpuup_callback, NULL, 0 };

3039
void __init setup_per_cpu_pageset(void)
3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053
{
	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
3054
static noinline __init_refok
3055
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3056 3057 3058
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
3059
	size_t alloc_size;
3060 3061 3062 3063 3064

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
3065 3066 3067 3068
	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);
3069 3070 3071
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

3072
	if (!slab_is_available()) {
3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085
		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.
		 */
3086
		zone->wait_table = vmalloc(alloc_size);
3087 3088 3089
	}
	if (!zone->wait_table)
		return -ENOMEM;
3090

3091
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3092
		init_waitqueue_head(zone->wait_table + i);
3093 3094

	return 0;
3095 3096
}

3097
static __meminit void zone_pcp_init(struct zone *zone)
3098 3099 3100 3101 3102 3103 3104
{
	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
3105
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
3106 3107 3108 3109 3110
		setup_pageset(&boot_pageset[cpu],0);
#else
		setup_pageset(zone_pcp(zone,cpu), batch);
#endif
	}
A
Anton Blanchard 已提交
3111 3112 3113
	if (zone->present_pages)
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%lu\n",
			zone->name, zone->present_pages, batch);
3114 3115
}

3116 3117
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
3118 3119
					unsigned long size,
					enum memmap_context context)
3120 3121
{
	struct pglist_data *pgdat = zone->zone_pgdat;
3122 3123 3124 3125
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
3126 3127 3128 3129
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

3130 3131 3132 3133 3134 3135
	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));

3136
	zone_init_free_lists(zone);
3137 3138

	return 0;
3139 3140
}

3141 3142 3143 3144 3145
#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
 */
3146
static int __meminit first_active_region_index_in_nid(int nid)
3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158
{
	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
3159
 * Note: nid == MAX_NUMNODES returns next region regardless of node
3160
 */
3161
static int __meminit next_active_region_index_in_nid(int index, int nid)
3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176
{
	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
 */
3177
int __meminit __early_pfn_to_nid(unsigned long pfn)
3178 3179 3180 3181 3182 3183 3184 3185 3186 3187
{
	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;
	}
3188 3189
	/* This is a memory hole */
	return -1;
3190 3191 3192
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

3193 3194
int __meminit early_pfn_to_nid(unsigned long pfn)
{
3195 3196 3197 3198 3199 3200 3201
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0)
		return nid;
	/* just returns 0 */
	return 0;
3202 3203
}

3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214
#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
3215

3216 3217 3218 3219 3220 3221 3222
/* 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
3223 3224
 * @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
3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251
 *
 * 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);
	}
}

3252 3253 3254
void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
{
	int i;
3255
	int ret;
3256

3257 3258 3259 3260 3261 3262
	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;
	}
3263
}
3264 3265
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3266
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3267 3268 3269
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
3270
 * function may be used instead of calling memory_present() manually.
3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283
 */
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
3284 3285 3286
 * @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.
3287 3288 3289 3290
 *
 * 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
3291
 * PFNs will be 0.
3292
 */
3293
void __meminit get_pfn_range_for_nid(unsigned int nid,
3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304
			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);
	}

3305
	if (*start_pfn == -1UL)
3306 3307 3308
		*start_pfn = 0;
}

M
Mel Gorman 已提交
3309 3310 3311 3312 3313
/*
 * 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
3314
static void __init find_usable_zone_for_movable(void)
M
Mel Gorman 已提交
3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339
{
	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
3340
static void __meminit adjust_zone_range_for_zone_movable(int nid,
M
Mel Gorman 已提交
3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365
					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;
	}
}

3366 3367 3368 3369
/*
 * 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
3370
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3371 3372 3373 3374 3375 3376 3377 3378 3379 3380
					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
3381 3382 3383
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398

	/* 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,
3399
 * then all holes in the requested range will be accounted for.
3400
 */
A
Adrian Bunk 已提交
3401
static unsigned long __meminit __absent_pages_in_range(int nid,
3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413
				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;

3414 3415
	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);

3416 3417
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
3418
		hole_pages = prev_end_pfn - range_start_pfn;
3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438

	/* 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;
	}

3439 3440
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
3441
		hole_pages += range_end_pfn -
3442 3443
				max(range_start_pfn, prev_end_pfn);

3444 3445 3446 3447 3448 3449 3450 3451
	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
 *
3452
 * It returns the number of pages frames in memory holes within a range.
3453 3454 3455 3456 3457 3458 3459 3460
 */
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
3461
static unsigned long __meminit zone_absent_pages_in_node(int nid,
3462 3463 3464
					unsigned long zone_type,
					unsigned long *ignored)
{
3465 3466 3467 3468 3469 3470 3471 3472 3473
	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
3474 3475 3476
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
3477
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3478
}
3479

3480
#else
P
Paul Mundt 已提交
3481
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3482 3483 3484 3485 3486 3487
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
3488
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3489 3490 3491 3492 3493 3494 3495 3496
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
3497

3498 3499
#endif

3500
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520
		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);
}

3521 3522 3523
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
3524 3525
 * 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
3526 3527 3528 3529 3530 3531 3532
 * 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;

3533 3534
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545
	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;
3546
	if (usemapsize)
3547 3548 3549 3550 3551 3552 3553
		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 */

3554
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3555 3556 3557 3558 3559 3560 3561 3562 3563 3564

/* 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;
}

3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579
/* 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 */

3580 3581 3582 3583 3584 3585 3586 3587 3588 3589
/*
 * 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;
}
3590 3591 3592 3593
#define set_pageblock_order(x)	do {} while (0)

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
3594 3595 3596 3597 3598 3599
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
3600
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3601 3602
		unsigned long *zones_size, unsigned long *zholes_size)
{
3603
	enum zone_type j;
3604
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
3605
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
3606
	int ret;
L
Linus Torvalds 已提交
3607

3608
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
3609 3610 3611
	pgdat->nr_zones = 0;
	init_waitqueue_head(&pgdat->kswapd_wait);
	pgdat->kswapd_max_order = 0;
3612
	pgdat_page_cgroup_init(pgdat);
L
Linus Torvalds 已提交
3613 3614 3615
	
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
3616
		unsigned long size, realsize, memmap_pages;
3617
		enum lru_list l;
L
Linus Torvalds 已提交
3618

3619 3620 3621
		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
3622

3623 3624 3625 3626 3627
		/*
		 * 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
		 */
3628 3629
		memmap_pages =
			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
3630 3631
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
3632 3633 3634 3635
			if (memmap_pages)
				printk(KERN_DEBUG
				       "  %s zone: %lu pages used for memmap\n",
				       zone_names[j], memmap_pages);
3636 3637 3638 3639 3640
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

3641 3642
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
3643
			realsize -= dma_reserve;
Y
Yinghai Lu 已提交
3644
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
3645
					zone_names[0], dma_reserve);
3646 3647
		}

3648
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
3649 3650 3651 3652 3653
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
3654
#ifdef CONFIG_NUMA
3655
		zone->node = nid;
3656
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3657
						/ 100;
3658
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3659
#endif
L
Linus Torvalds 已提交
3660 3661 3662
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
3663
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
3664 3665
		zone->zone_pgdat = pgdat;

3666
		zone->prev_priority = DEF_PRIORITY;
L
Linus Torvalds 已提交
3667

3668
		zone_pcp_init(zone);
3669 3670 3671 3672
		for_each_lru(l) {
			INIT_LIST_HEAD(&zone->lru[l].list);
			zone->lru[l].nr_scan = 0;
		}
3673 3674 3675 3676
		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;
3677
		zap_zone_vm_stats(zone);
3678
		zone->flags = 0;
L
Linus Torvalds 已提交
3679 3680 3681
		if (!size)
			continue;

3682
		set_pageblock_order(pageblock_default_order());
3683
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
3684 3685
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
3686
		BUG_ON(ret);
3687
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
3688 3689 3690 3691
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
3692
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
3693 3694 3695 3696 3697
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
3698
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
3699 3700
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
3701
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
3702 3703
		struct page *map;

3704 3705 3706 3707 3708 3709 3710 3711 3712
		/*
		 * 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);
3713 3714 3715
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
3716
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
3717
	}
3718
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
3719 3720 3721
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
3722
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
3723
		mem_map = NODE_DATA(0)->node_mem_map;
3724 3725
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3726
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3727 3728
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
3729
#endif
A
Andy Whitcroft 已提交
3730
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
3731 3732
}

3733 3734
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
3735
{
3736 3737
	pg_data_t *pgdat = NODE_DATA(nid);

L
Linus Torvalds 已提交
3738 3739
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
3740
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
3741 3742

	alloc_node_mem_map(pgdat);
3743 3744 3745 3746 3747
#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
3748 3749 3750 3751

	free_area_init_core(pgdat, zones_size, zholes_size);
}

3752
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
M
Miklos Szeredi 已提交
3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772

#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

3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789
/**
 * 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;

3790 3791 3792 3793 3794
	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);
3795

3796 3797
	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);

3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836
	/* 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;
}

/**
3837
 * remove_active_range - Shrink an existing registered range of PFNs
3838
 * @nid: The node id the range is on that should be shrunk
3839 3840
 * @start_pfn: The new PFN of the range
 * @end_pfn: The new PFN of the range
3841 3842
 *
 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3843 3844 3845
 * 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.
3846
 */
3847 3848
void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
				unsigned long end_pfn)
3849
{
3850 3851
	int i, j;
	int removed = 0;
3852

3853 3854 3855
	printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
			  nid, start_pfn, end_pfn);

3856
	/* Find the old active region end and shrink */
3857
	for_each_active_range_index_in_nid(i, nid) {
3858 3859
		if (early_node_map[i].start_pfn >= start_pfn &&
		    early_node_map[i].end_pfn <= end_pfn) {
3860
			/* clear it */
3861
			early_node_map[i].start_pfn = 0;
3862 3863 3864 3865
			early_node_map[i].end_pfn = 0;
			removed = 1;
			continue;
		}
3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877
		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;
3878
			continue;
3879
		}
3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898
	}

	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--;
	}
3899 3900 3901 3902
}

/**
 * remove_all_active_ranges - Remove all currently registered regions
3903
 *
3904 3905 3906 3907
 * 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.
 */
3908
void __init remove_all_active_ranges(void)
3909 3910 3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936
{
	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);
}

3937
/* Find the lowest pfn for a node */
A
Adrian Bunk 已提交
3938
static unsigned long __init find_min_pfn_for_node(int nid)
3939 3940
{
	int i;
3941
	unsigned long min_pfn = ULONG_MAX;
3942

3943 3944
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
3945
		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
3946

3947 3948
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
3949
			"Could not find start_pfn for node %d\n", nid);
3950 3951 3952 3953
		return 0;
	}

	return min_pfn;
3954 3955 3956 3957 3958 3959
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
3960
 * add_active_range().
3961 3962 3963 3964 3965 3966
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

3967 3968 3969 3970 3971
/*
 * 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
3972
static unsigned long __init early_calculate_totalpages(void)
3973 3974 3975 3976
{
	int i;
	unsigned long totalpages = 0;

3977 3978
	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long pages = early_node_map[i].end_pfn -
3979
						early_node_map[i].start_pfn;
3980 3981 3982 3983 3984
		totalpages += pages;
		if (pages)
			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
	}
  	return totalpages;
3985 3986
}

M
Mel Gorman 已提交
3987 3988 3989 3990 3991 3992
/*
 * 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
3993
static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
M
Mel Gorman 已提交
3994 3995 3996 3997
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
3998 3999
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
4000

4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022
	/*
	 * 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
4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033
	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
	if (!required_kernelcore)
		return;

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

restart:
	/* Spread kernelcore memory as evenly as possible throughout nodes */
	kernelcore_node = required_kernelcore / usable_nodes;
4034
	for_each_node_state(nid, N_HIGH_MEMORY) {
M
Mel Gorman 已提交
4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080 4081 4082 4083 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 4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125
		/*
		 * 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);
}

4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137 4138 4139
/* 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
}

4140 4141
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
4142
 * @max_zone_pfn: an array of max PFNs for each zone
4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155
 *
 * 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;
4156
	int i;
4157

4158 4159 4160
	/* Sort early_node_map as initialisation assumes it is sorted */
	sort_node_map();

4161 4162 4163 4164 4165 4166 4167 4168
	/* 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
4169 4170
		if (i == ZONE_MOVABLE)
			continue;
4171 4172 4173 4174 4175
		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
4176 4177 4178 4179 4180 4181
	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);
4182 4183 4184

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
M
Mel Gorman 已提交
4185 4186 4187
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
4188
		printk("  %-8s %0#10lx -> %0#10lx\n",
4189 4190 4191
				zone_names[i],
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);
M
Mel Gorman 已提交
4192 4193 4194 4195 4196 4197 4198 4199
	}

	/* 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]);
	}
4200 4201 4202 4203

	/* 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++)
4204
		printk("  %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4205 4206 4207 4208
						early_node_map[i].start_pfn,
						early_node_map[i].end_pfn);

	/* Initialise every node */
4209
	mminit_verify_pageflags_layout();
4210
	setup_nr_node_ids();
4211 4212
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
4213
		free_area_init_node(nid, NULL,
4214
				find_min_pfn_for_node(nid), NULL);
4215 4216 4217 4218 4219

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
4220 4221
	}
}
M
Mel Gorman 已提交
4222

4223
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
4224 4225 4226 4227 4228 4229
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
4230
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
4231

4232
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
4233 4234 4235 4236
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
4237

4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255
/*
 * 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
4256
early_param("kernelcore", cmdline_parse_kernelcore);
4257
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
4258

4259 4260
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

4261
/**
4262 4263
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
4264 4265 4266 4267
 *
 * 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
4268 4269 4270
 * 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.
4271 4272 4273 4274 4275 4276
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

4277
#ifndef CONFIG_NEED_MULTIPLE_NODES
4278
struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] };
L
Linus Torvalds 已提交
4279
EXPORT_SYMBOL(contig_page_data);
4280
#endif
L
Linus Torvalds 已提交
4281 4282 4283

void __init free_area_init(unsigned long *zones_size)
{
4284
	free_area_init_node(0, zones_size,
L
Linus Torvalds 已提交
4285 4286 4287 4288 4289 4290 4291 4292
			__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;

4293
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4294 4295 4296 4297 4298 4299 4300 4301
		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.
		 */
4302
		vm_events_fold_cpu(cpu);
4303 4304 4305 4306 4307 4308 4309 4310

		/*
		 * 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.
		 */
4311
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
4312 4313 4314 4315 4316 4317 4318 4319 4320
	}
	return NOTIFY_OK;
}

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

4321 4322 4323 4324 4325 4326 4327 4328
/*
 * 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;
4329
	enum zone_type i, j;
4330 4331 4332 4333 4334 4335 4336 4337 4338 4339 4340 4341

	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];
			}

4342 4343
			/* we treat the high watermark as reserved pages. */
			max += high_wmark_pages(zone);
4344 4345 4346 4347 4348 4349 4350 4351 4352

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

L
Linus Torvalds 已提交
4353 4354 4355 4356 4357 4358 4359 4360 4361
/*
 * 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;
4362
	enum zone_type j, idx;
L
Linus Torvalds 已提交
4363

4364
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
4365 4366 4367 4368 4369 4370
		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;

4371 4372
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
4373 4374
				struct zone *lower_zone;

4375 4376
				idx--;

L
Linus Torvalds 已提交
4377 4378 4379 4380 4381 4382 4383 4384 4385 4386
				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;
			}
		}
	}
4387 4388 4389

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
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Linus Torvalds 已提交
4390 4391
}

4392 4393 4394 4395 4396
/**
 * setup_per_zone_pages_min - called when min_free_kbytes changes.
 *
 * Ensures that the pages_{min,low,high} values for each zone are set correctly
 * with respect to min_free_kbytes.
L
Linus Torvalds 已提交
4397
 */
4398
void setup_per_zone_pages_min(void)
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4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 4410 4411
{
	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) {
4412 4413
		u64 tmp;

4414
		spin_lock_irqsave(&zone->lock, flags);
4415 4416
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
4417 4418
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
4419 4420 4421 4422
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
4423
			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
N
Nick Piggin 已提交
4424 4425
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
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4426 4427 4428 4429 4430 4431 4432 4433
			 */
			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;
4434
			zone->watermark[WMARK_MIN] = min_pages;
L
Linus Torvalds 已提交
4435
		} else {
N
Nick Piggin 已提交
4436 4437
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
4438 4439
			 * proportionate to the zone's size.
			 */
4440
			zone->watermark[WMARK_MIN] = tmp;
L
Linus Torvalds 已提交
4441 4442
		}

4443 4444
		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) + (tmp >> 2);
		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
4445
		setup_zone_migrate_reserve(zone);
4446
		spin_unlock_irqrestore(&zone->lock, flags);
L
Linus Torvalds 已提交
4447
	}
4448 4449 4450

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4451 4452
}

4453 4454 4455 4456 4457 4458 4459 4460 4461 4462 4463 4464 4465 4466 4467 4468 4469 4470 4471 4472 4473 4474 4475
/**
 * setup_per_zone_inactive_ratio - called when min_free_kbytes changes.
 *
 * The inactive anon list should be small enough that the VM never has to
 * do too much work, but large enough that each inactive page has a chance
 * to be referenced again before it is swapped out.
 *
 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
 * INACTIVE_ANON pages on this zone's LRU, maintained by the
 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
 * the anonymous pages are kept on the inactive list.
 *
 * total     target    max
 * memory    ratio     inactive anon
 * -------------------------------------
 *   10MB       1         5MB
 *  100MB       1        50MB
 *    1GB       3       250MB
 *   10GB      10       0.9GB
 *  100GB      31         3GB
 *    1TB     101        10GB
 *   10TB     320        32GB
 */
4476
static void setup_per_zone_inactive_ratio(void)
4477 4478 4479 4480 4481 4482 4483 4484 4485 4486 4487 4488 4489 4490 4491 4492
{
	struct zone *zone;

	for_each_zone(zone) {
		unsigned int gb, ratio;

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

		zone->inactive_ratio = ratio;
	}
}

L
Linus Torvalds 已提交
4493 4494 4495 4496 4497 4498 4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516 4517 4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529
/*
 * Initialise min_free_kbytes.
 *
 * For small machines we want it small (128k min).  For large machines
 * we want it large (64MB max).  But it is not linear, because network
 * bandwidth does not increase linearly with machine size.  We use
 *
 * 	min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
 *	min_free_kbytes = sqrt(lowmem_kbytes * 16)
 *
 * which yields
 *
 * 16MB:	512k
 * 32MB:	724k
 * 64MB:	1024k
 * 128MB:	1448k
 * 256MB:	2048k
 * 512MB:	2896k
 * 1024MB:	4096k
 * 2048MB:	5792k
 * 4096MB:	8192k
 * 8192MB:	11584k
 * 16384MB:	16384k
 */
static int __init init_per_zone_pages_min(void)
{
	unsigned long lowmem_kbytes;

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

	min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
	if (min_free_kbytes < 128)
		min_free_kbytes = 128;
	if (min_free_kbytes > 65536)
		min_free_kbytes = 65536;
	setup_per_zone_pages_min();
	setup_per_zone_lowmem_reserve();
4530
	setup_per_zone_inactive_ratio();
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Linus Torvalds 已提交
4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543
	return 0;
}
module_init(init_per_zone_pages_min)

/*
 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 
 *	that we can call two helper functions whenever min_free_kbytes
 *	changes.
 */
int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	proc_dointvec(table, write, file, buffer, length, ppos);
4544 4545
	if (write)
		setup_per_zone_pages_min();
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Linus Torvalds 已提交
4546 4547 4548
	return 0;
}

4549 4550 4551 4552 4553 4554 4555 4556 4557 4558 4559 4560
#ifdef CONFIG_NUMA
int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	struct zone *zone;
	int rc;

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

	for_each_zone(zone)
4561
		zone->min_unmapped_pages = (zone->present_pages *
4562 4563 4564
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
4565 4566 4567 4568 4569 4570 4571 4572 4573 4574 4575 4576 4577 4578 4579 4580

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

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

	for_each_zone(zone)
		zone->min_slab_pages = (zone->present_pages *
				sysctl_min_slab_ratio) / 100;
	return 0;
}
4581 4582
#endif

L
Linus Torvalds 已提交
4583 4584 4585 4586 4587 4588
/*
 * 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
4589
 * minimum watermarks. The lowmem reserve ratio can only make sense
L
Linus Torvalds 已提交
4590 4591 4592 4593 4594 4595 4596 4597 4598 4599
 * if in function of the boot time zone sizes.
 */
int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	proc_dointvec_minmax(table, write, file, buffer, length, ppos);
	setup_per_zone_lowmem_reserve();
	return 0;
}

4600 4601 4602 4603 4604 4605 4606 4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625
/*
 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
 * cpu.  It is the fraction of total pages in each zone that a hot per cpu pagelist
 * can have before it gets flushed back to buddy allocator.
 */

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

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

4626
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
4627 4628 4629 4630 4631 4632 4633 4634 4635 4636 4637 4638 4639 4640 4641 4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655 4656 4657 4658 4659 4660

#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
4661
		numentries = nr_kernel_pages;
L
Linus Torvalds 已提交
4662 4663 4664 4665 4666 4667 4668 4669 4670
		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);
4671 4672 4673 4674

		/* Make sure we've got at least a 0-order allocation.. */
		if (unlikely((numentries * bucketsize) < PAGE_SIZE))
			numentries = PAGE_SIZE / bucketsize;
L
Linus Torvalds 已提交
4675
	}
4676
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
4677 4678 4679 4680 4681 4682 4683 4684 4685 4686

	/* 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;

4687
	log2qty = ilog2(numentries);
L
Linus Torvalds 已提交
4688 4689 4690 4691

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
4692
			table = alloc_bootmem_nopanic(size);
L
Linus Torvalds 已提交
4693 4694 4695
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
4696
			unsigned long order = get_order(size);
4697 4698 4699 4700

			if (order < MAX_ORDER)
				table = (void *)__get_free_pages(GFP_ATOMIC,
								order);
4701 4702 4703 4704 4705 4706 4707 4708 4709 4710 4711 4712 4713 4714 4715
			/*
			 * If bucketsize is not a power-of-two, we may free
			 * some pages at the end of hash table.
			 */
			if (table) {
				unsigned long alloc_end = (unsigned long)table +
						(PAGE_SIZE << order);
				unsigned long used = (unsigned long)table +
						PAGE_ALIGN(size);
				split_page(virt_to_page(table), order);
				while (used < alloc_end) {
					free_page(used);
					used += PAGE_SIZE;
				}
			}
L
Linus Torvalds 已提交
4716 4717 4718 4719 4720 4721
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

4722
	printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
L
Linus Torvalds 已提交
4723 4724
	       tablename,
	       (1U << log2qty),
4725
	       ilog2(size) - PAGE_SHIFT,
L
Linus Torvalds 已提交
4726 4727 4728 4729 4730 4731 4732
	       size);

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

4733 4734 4735 4736 4737 4738 4739 4740 4741 4742
	/*
	 * If hashdist is set, the table allocation is done with __vmalloc()
	 * which invokes the kmemleak_alloc() callback. This function may also
	 * be called before the slab and kmemleak are initialised when
	 * kmemleak simply buffers the request to be executed later
	 * (GFP_ATOMIC flag ignored in this case).
	 */
	if (!hashdist)
		kmemleak_alloc(table, size, 1, GFP_ATOMIC);

L
Linus Torvalds 已提交
4743 4744
	return table;
}
4745

4746 4747 4748 4749 4750 4751 4752 4753 4754 4755 4756 4757 4758 4759 4760
/* 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);
4761
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4762 4763
#else
	pfn = pfn - zone->zone_start_pfn;
4764
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4765 4766 4767 4768
#endif /* CONFIG_SPARSEMEM */
}

/**
4769
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4770 4771 4772 4773 4774 4775 4776 4777 4778 4779 4780 4781 4782 4783 4784 4785 4786 4787 4788 4789 4790 4791
 * @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;
4792

4793 4794 4795 4796
	return flags;
}

/**
4797
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4798 4799 4800 4801 4802 4803 4804 4805 4806 4807 4808 4809 4810 4811 4812 4813 4814
 * @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);
4815 4816
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
4817 4818 4819 4820 4821 4822 4823

	for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
		if (flags & value)
			__set_bit(bitidx + start_bitidx, bitmap);
		else
			__clear_bit(bitidx + start_bitidx, bitmap);
}
K
KAMEZAWA Hiroyuki 已提交
4824 4825 4826 4827 4828 4829 4830 4831 4832 4833 4834 4835 4836 4837 4838 4839 4840 4841 4842 4843 4844 4845 4846 4847 4848 4849

/*
 * This is designed as sub function...plz see page_isolation.c also.
 * set/clear page block's type to be ISOLATE.
 * page allocater never alloc memory from ISOLATE block.
 */

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

	zone = page_zone(page);
	spin_lock_irqsave(&zone->lock, flags);
	/*
	 * In future, more migrate types will be able to be isolation target.
	 */
	if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE)
		goto out;
	set_pageblock_migratetype(page, MIGRATE_ISOLATE);
	move_freepages_block(zone, page, MIGRATE_ISOLATE);
	ret = 0;
out:
	spin_unlock_irqrestore(&zone->lock, flags);
	if (!ret)
4850
		drain_all_pages();
K
KAMEZAWA Hiroyuki 已提交
4851 4852 4853 4854 4855 4856 4857 4858 4859 4860 4861 4862 4863 4864 4865 4866
	return ret;
}

void unset_migratetype_isolate(struct page *page)
{
	struct zone *zone;
	unsigned long flags;
	zone = page_zone(page);
	spin_lock_irqsave(&zone->lock, flags);
	if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
		goto out;
	set_pageblock_migratetype(page, MIGRATE_MOVABLE);
	move_freepages_block(zone, page, MIGRATE_MOVABLE);
out:
	spin_unlock_irqrestore(&zone->lock, flags);
}
K
KAMEZAWA Hiroyuki 已提交
4867 4868 4869 4870 4871 4872 4873 4874 4875 4876 4877 4878 4879 4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893 4894 4895 4896 4897 4898 4899 4900 4901 4902 4903 4904 4905 4906 4907 4908 4909 4910 4911 4912 4913

#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