page_alloc.c 138.6 KB
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/*
 *  linux/mm/page_alloc.c
 *
 *  Manages the free list, the system allocates free pages here.
 *  Note that kmalloc() lives in slab.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *  Swap reorganised 29.12.95, Stephen Tweedie
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *  Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
 *  Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
 *  Zone balancing, Kanoj Sarcar, SGI, Jan 2000
 *  Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
 *          (lots of bits borrowed from Ingo Molnar & Andrew Morton)
 */

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

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

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unsigned long totalram_pages __read_mostly;
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unsigned long totalreserve_pages __read_mostly;
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int percpu_pagelist_fraction;
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gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
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#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
int pageblock_order __read_mostly;
#endif

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

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

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int min_free_kbytes = 1024;

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

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

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

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int page_group_by_mobility_disabled __read_mostly;

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static void set_pageblock_migratetype(struct page *page, int migratetype)
{
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	if (unlikely(page_group_by_mobility_disabled))
		migratetype = MIGRATE_UNMOVABLE;

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

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bool oom_killer_disabled __read_mostly;

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

	return ret;
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}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	return page + (buddy_idx - page_idx);
}

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

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

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

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

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

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static inline void __free_one_page(struct page *page,
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		struct zone *zone, unsigned int order,
		int migratetype)
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{
	unsigned long page_idx;

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

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

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

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

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

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

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

		/*
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		 * Remove pages from lists in a round-robin fashion. A
		 * batch_free count is maintained that is incremented when an
		 * empty list is encountered.  This is so more pages are freed
		 * off fuller lists instead of spinning excessively around empty
		 * lists
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		 */
		do {
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			batch_free++;
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			if (++migratetype == MIGRATE_PCPTYPES)
				migratetype = 0;
			list = &pcp->lists[migratetype];
		} while (list_empty(list));
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		do {
			page = list_entry(list->prev, struct page, lru);
			/* must delete as __free_one_page list manipulates */
			list_del(&page->lru);
			__free_one_page(page, zone, 0, migratetype);
			trace_mm_page_pcpu_drain(page, 0, migratetype);
		} while (--count && --batch_free && !list_empty(list));
L
Linus Torvalds 已提交
559
	}
N
Nick Piggin 已提交
560
	spin_unlock(&zone->lock);
L
Linus Torvalds 已提交
561 562
}

563 564
static void free_one_page(struct zone *zone, struct page *page, int order,
				int migratetype)
L
Linus Torvalds 已提交
565
{
566
	spin_lock(&zone->lock);
567
	zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
568
	zone->pages_scanned = 0;
569 570

	__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
571
	__free_one_page(page, zone, order, migratetype);
572
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
573 574 575 576 577
}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
L
Linus Torvalds 已提交
578
	int i;
579
	int bad = 0;
580
	int wasMlocked = __TestClearPageMlocked(page);
L
Linus Torvalds 已提交
581

582 583
	kmemcheck_free_shadow(page, order);

L
Linus Torvalds 已提交
584
	for (i = 0 ; i < (1 << order) ; ++i)
585 586
		bad += free_pages_check(page + i);
	if (bad)
587 588
		return;

589
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
590
		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
591 592 593
		debug_check_no_obj_freed(page_address(page),
					   PAGE_SIZE << order);
	}
N
Nick Piggin 已提交
594
	arch_free_page(page, order);
N
Nick Piggin 已提交
595
	kernel_map_pages(page, 1 << order, 0);
N
Nick Piggin 已提交
596

N
Nick Piggin 已提交
597
	local_irq_save(flags);
598
	if (unlikely(wasMlocked))
599
		free_page_mlock(page);
600
	__count_vm_events(PGFREE, 1 << order);
601 602
	free_one_page(page_zone(page), page, order,
					get_pageblock_migratetype(page));
N
Nick Piggin 已提交
603
	local_irq_restore(flags);
L
Linus Torvalds 已提交
604 605
}

606 607 608
/*
 * permit the bootmem allocator to evade page validation on high-order frees
 */
609
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
610 611 612 613
{
	if (order == 0) {
		__ClearPageReserved(page);
		set_page_count(page, 0);
614
		set_page_refcounted(page);
N
Nick Piggin 已提交
615
		__free_page(page);
616 617 618
	} else {
		int loop;

N
Nick Piggin 已提交
619
		prefetchw(page);
620 621 622
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

N
Nick Piggin 已提交
623 624
			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
625 626 627 628
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

629
		set_page_refcounted(page);
N
Nick Piggin 已提交
630
		__free_pages(page, order);
631 632 633
	}
}

L
Linus Torvalds 已提交
634 635 636 637 638 639 640 641 642 643 644 645 646 647 648

/*
 * 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
649
static inline void expand(struct zone *zone, struct page *page,
650 651
	int low, int high, struct free_area *area,
	int migratetype)
L
Linus Torvalds 已提交
652 653 654 655 656 657 658
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
659
		VM_BUG_ON(bad_range(zone, &page[size]));
660
		list_add(&page[size].lru, &area->free_list[migratetype]);
L
Linus Torvalds 已提交
661 662 663 664 665 666 667 668
		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
669
static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
L
Linus Torvalds 已提交
670
{
N
Nick Piggin 已提交
671 672
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
673
		(atomic_read(&page->_count) != 0)  |
674
		(page->flags & PAGE_FLAGS_CHECK_AT_PREP))) {
N
Nick Piggin 已提交
675
		bad_page(page);
676
		return 1;
677
	}
678

H
Hugh Dickins 已提交
679
	set_page_private(page, 0);
680
	set_page_refcounted(page);
N
Nick Piggin 已提交
681 682

	arch_alloc_page(page, order);
L
Linus Torvalds 已提交
683
	kernel_map_pages(page, 1 << order, 1);
N
Nick Piggin 已提交
684 685 686 687 688 689 690

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

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

691
	return 0;
L
Linus Torvalds 已提交
692 693
}

694 695 696 697
/*
 * Go through the free lists for the given migratetype and remove
 * the smallest available page from the freelists
 */
698 699
static inline
struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724
						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;
}


725 726 727 728 729
/*
 * 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] = {
730 731 732 733
	[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 */
734 735
};

736 737
/*
 * Move the free pages in a range to the free lists of the requested type.
738
 * Note that start_page and end_pages are not aligned on a pageblock
739 740
 * boundary. If alignment is required, use move_freepages_block()
 */
A
Adrian Bunk 已提交
741 742 743
static int move_freepages(struct zone *zone,
			  struct page *start_page, struct page *end_page,
			  int migratetype)
744 745 746
{
	struct page *page;
	unsigned long order;
747
	int pages_moved = 0;
748 749 750 751 752 753 754

#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
755
	 * grouping pages by mobility
756 757 758 759 760
	 */
	BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif

	for (page = start_page; page <= end_page;) {
761 762 763
		/* Make sure we are not inadvertently changing nodes */
		VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));

764 765 766 767 768 769 770 771 772 773 774 775 776 777 778
		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;
779
		pages_moved += 1 << order;
780 781
	}

782
	return pages_moved;
783 784
}

A
Adrian Bunk 已提交
785 786
static int move_freepages_block(struct zone *zone, struct page *page,
				int migratetype)
787 788 789 790 791
{
	unsigned long start_pfn, end_pfn;
	struct page *start_page, *end_page;

	start_pfn = page_to_pfn(page);
792
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
793
	start_page = pfn_to_page(start_pfn);
794 795
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
796 797 798 799 800 801 802 803 804 805

	/* 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);
}

806 807 808 809 810 811 812 813 814 815 816
static void change_pageblock_range(struct page *pageblock_page,
					int start_order, int migratetype)
{
	int nr_pageblocks = 1 << (start_order - pageblock_order);

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

817
/* Remove an element from the buddy allocator from the fallback list */
818 819
static inline struct page *
__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
820 821 822 823 824 825 826 827 828 829 830 831
{
	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];

832 833 834
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
				continue;
M
Mel Gorman 已提交
835

836 837 838 839 840 841 842 843 844
			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--;

			/*
845
			 * If breaking a large block of pages, move all free
846 847 848
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
			 * agressive about taking ownership of free pages
849
			 */
850
			if (unlikely(current_order >= (pageblock_order >> 1)) ||
851 852
					start_migratetype == MIGRATE_RECLAIMABLE ||
					page_group_by_mobility_disabled) {
853 854 855 856 857
				unsigned long pages;
				pages = move_freepages_block(zone, page,
								start_migratetype);

				/* Claim the whole block if over half of it is free */
858 859
				if (pages >= (1 << (pageblock_order-1)) ||
						page_group_by_mobility_disabled)
860 861 862
					set_pageblock_migratetype(page,
								start_migratetype);

863
				migratetype = start_migratetype;
864
			}
865 866 867 868 869

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

870 871 872
			/* Take ownership for orders >= pageblock_order */
			if (current_order >= pageblock_order)
				change_pageblock_range(page, current_order,
873 874 875
							start_migratetype);

			expand(zone, page, order, current_order, area, migratetype);
876 877 878 879

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

880 881 882 883
			return page;
		}
	}

884
	return NULL;
885 886
}

887
/*
L
Linus Torvalds 已提交
888 889 890
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
891 892
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
L
Linus Torvalds 已提交
893 894 895
{
	struct page *page;

896
retry_reserve:
897
	page = __rmqueue_smallest(zone, order, migratetype);
898

899
	if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
900
		page = __rmqueue_fallback(zone, order, migratetype);
901

902 903 904 905 906 907 908 909 910 911 912
		/*
		 * 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;
		}
	}

913
	trace_mm_page_alloc_zone_locked(page, order, migratetype);
914
	return page;
L
Linus Torvalds 已提交
915 916 917 918 919 920 921 922
}

/* 
 * 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, 
923
			unsigned long count, struct list_head *list,
924
			int migratetype, int cold)
L
Linus Torvalds 已提交
925 926 927
{
	int i;
	
N
Nick Piggin 已提交
928
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
929
	for (i = 0; i < count; ++i) {
930
		struct page *page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
931
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
932
			break;
933 934 935 936 937 938 939 940 941 942

		/*
		 * 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.
		 */
943 944 945 946
		if (likely(cold == 0))
			list_add(&page->lru, list);
		else
			list_add_tail(&page->lru, list);
947
		set_page_private(page, migratetype);
948
		list = &page->lru;
L
Linus Torvalds 已提交
949
	}
950
	__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
N
Nick Piggin 已提交
951
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
952
	return i;
L
Linus Torvalds 已提交
953 954
}

955
#ifdef CONFIG_NUMA
956
/*
957 958 959 960
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
961 962
 * Note that this function must be called with the thread pinned to
 * a single processor.
963
 */
964
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
965 966
{
	unsigned long flags;
967
	int to_drain;
968

969 970 971 972 973
	local_irq_save(flags);
	if (pcp->count >= pcp->batch)
		to_drain = pcp->batch;
	else
		to_drain = pcp->count;
974
	free_pcppages_bulk(zone, to_drain, pcp);
975 976
	pcp->count -= to_drain;
	local_irq_restore(flags);
977 978 979
}
#endif

980 981 982 983 984 985 986 987
/*
 * 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
988
{
N
Nick Piggin 已提交
989
	unsigned long flags;
L
Linus Torvalds 已提交
990 991
	struct zone *zone;

992
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
993
		struct per_cpu_pageset *pset;
994
		struct per_cpu_pages *pcp;
L
Linus Torvalds 已提交
995

996
		pset = zone_pcp(zone, cpu);
997 998 999

		pcp = &pset->pcp;
		local_irq_save(flags);
1000
		free_pcppages_bulk(zone, pcp->count, pcp);
1001 1002
		pcp->count = 0;
		local_irq_restore(flags);
L
Linus Torvalds 已提交
1003 1004 1005
	}
}

1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018
/*
 * 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)
{
1019
	on_each_cpu(drain_local_pages, NULL, 1);
1020 1021
}

1022
#ifdef CONFIG_HIBERNATION
L
Linus Torvalds 已提交
1023 1024 1025

void mark_free_pages(struct zone *zone)
{
1026 1027
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
1028
	int order, t;
L
Linus Torvalds 已提交
1029 1030 1031 1032 1033 1034
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
1035 1036 1037 1038 1039 1040

	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);

1041 1042
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
1043
		}
L
Linus Torvalds 已提交
1044

1045 1046
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
1047
			unsigned long i;
L
Linus Torvalds 已提交
1048

1049 1050
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
1051
				swsusp_set_page_free(pfn_to_page(pfn + i));
1052
		}
1053
	}
L
Linus Torvalds 已提交
1054 1055
	spin_unlock_irqrestore(&zone->lock, flags);
}
1056
#endif /* CONFIG_PM */
L
Linus Torvalds 已提交
1057 1058 1059 1060

/*
 * Free a 0-order page
 */
H
Harvey Harrison 已提交
1061
static void free_hot_cold_page(struct page *page, int cold)
L
Linus Torvalds 已提交
1062 1063 1064 1065
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;
1066
	int migratetype;
1067
	int wasMlocked = __TestClearPageMlocked(page);
L
Linus Torvalds 已提交
1068

1069 1070
	kmemcheck_free_shadow(page, 0);

L
Linus Torvalds 已提交
1071 1072
	if (PageAnon(page))
		page->mapping = NULL;
N
Nick Piggin 已提交
1073
	if (free_pages_check(page))
1074 1075
		return;

1076
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
1077
		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
1078 1079
		debug_check_no_obj_freed(page_address(page), PAGE_SIZE);
	}
N
Nick Piggin 已提交
1080
	arch_free_page(page, 0);
1081 1082
	kernel_map_pages(page, 1, 0);

1083
	pcp = &zone_pcp(zone, get_cpu())->pcp;
1084 1085
	migratetype = get_pageblock_migratetype(page);
	set_page_private(page, migratetype);
L
Linus Torvalds 已提交
1086
	local_irq_save(flags);
1087
	if (unlikely(wasMlocked))
1088
		free_page_mlock(page);
1089
	__count_vm_event(PGFREE);
1090

1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105
	/*
	 * We only track unmovable, reclaimable and movable on pcp lists.
	 * Free ISOLATE pages back to the allocator because they are being
	 * offlined but treat RESERVE as movable pages so we can get those
	 * areas back if necessary. Otherwise, we may have to free
	 * excessively into the page allocator
	 */
	if (migratetype >= MIGRATE_PCPTYPES) {
		if (unlikely(migratetype == MIGRATE_ISOLATE)) {
			free_one_page(zone, page, 0, migratetype);
			goto out;
		}
		migratetype = MIGRATE_MOVABLE;
	}

1106
	if (cold)
1107
		list_add_tail(&page->lru, &pcp->lists[migratetype]);
1108
	else
1109
		list_add(&page->lru, &pcp->lists[migratetype]);
L
Linus Torvalds 已提交
1110
	pcp->count++;
N
Nick Piggin 已提交
1111
	if (pcp->count >= pcp->high) {
1112
		free_pcppages_bulk(zone, pcp->batch, pcp);
N
Nick Piggin 已提交
1113 1114
		pcp->count -= pcp->batch;
	}
1115 1116

out:
L
Linus Torvalds 已提交
1117 1118 1119 1120
	local_irq_restore(flags);
	put_cpu();
}

H
Harvey Harrison 已提交
1121
void free_hot_page(struct page *page)
L
Linus Torvalds 已提交
1122
{
1123
	trace_mm_page_free_direct(page, 0);
L
Linus Torvalds 已提交
1124 1125 1126
	free_hot_cold_page(page, 0);
}
	
N
Nick Piggin 已提交
1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138
/*
 * 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
1139 1140
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1141 1142 1143 1144 1145 1146 1147 1148 1149 1150

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

1151 1152
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
1153 1154
}

L
Linus Torvalds 已提交
1155 1156 1157 1158 1159
/*
 * 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.
 */
1160 1161
static inline
struct page *buffered_rmqueue(struct zone *preferred_zone,
1162 1163
			struct zone *zone, int order, gfp_t gfp_flags,
			int migratetype)
L
Linus Torvalds 已提交
1164 1165
{
	unsigned long flags;
1166
	struct page *page;
L
Linus Torvalds 已提交
1167
	int cold = !!(gfp_flags & __GFP_COLD);
N
Nick Piggin 已提交
1168
	int cpu;
L
Linus Torvalds 已提交
1169

1170
again:
N
Nick Piggin 已提交
1171
	cpu  = get_cpu();
N
Nick Piggin 已提交
1172
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1173
		struct per_cpu_pages *pcp;
1174
		struct list_head *list;
L
Linus Torvalds 已提交
1175

1176
		pcp = &zone_pcp(zone, cpu)->pcp;
1177
		list = &pcp->lists[migratetype];
L
Linus Torvalds 已提交
1178
		local_irq_save(flags);
1179
		if (list_empty(list)) {
1180
			pcp->count += rmqueue_bulk(zone, 0,
1181
					pcp->batch, list,
1182
					migratetype, cold);
1183
			if (unlikely(list_empty(list)))
1184
				goto failed;
1185
		}
1186

1187 1188 1189 1190 1191
		if (cold)
			page = list_entry(list->prev, struct page, lru);
		else
			page = list_entry(list->next, struct page, lru);

1192 1193
		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1194
	} else {
1195 1196 1197 1198 1199 1200 1201 1202
		if (unlikely(gfp_flags & __GFP_NOFAIL)) {
			/*
			 * __GFP_NOFAIL is not to be used in new code.
			 *
			 * All __GFP_NOFAIL callers should be fixed so that they
			 * properly detect and handle allocation failures.
			 *
			 * We most definitely don't want callers attempting to
1203
			 * allocate greater than order-1 page units with
1204 1205
			 * __GFP_NOFAIL.
			 */
1206
			WARN_ON_ONCE(order > 1);
1207
		}
L
Linus Torvalds 已提交
1208
		spin_lock_irqsave(&zone->lock, flags);
1209
		page = __rmqueue(zone, order, migratetype);
1210
		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
N
Nick Piggin 已提交
1211 1212 1213
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
L
Linus Torvalds 已提交
1214 1215
	}

1216
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1217
	zone_statistics(preferred_zone, zone);
N
Nick Piggin 已提交
1218 1219
	local_irq_restore(flags);
	put_cpu();
L
Linus Torvalds 已提交
1220

N
Nick Piggin 已提交
1221
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1222
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1223
		goto again;
L
Linus Torvalds 已提交
1224
	return page;
N
Nick Piggin 已提交
1225 1226 1227 1228 1229

failed:
	local_irq_restore(flags);
	put_cpu();
	return NULL;
L
Linus Torvalds 已提交
1230 1231
}

1232 1233 1234 1235 1236 1237 1238 1239 1240
/* 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)

1241 1242 1243
#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
1244

1245 1246 1247 1248 1249 1250 1251
#ifdef CONFIG_FAIL_PAGE_ALLOC

static struct fail_page_alloc_attr {
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1252
	u32 min_order;
1253 1254 1255 1256 1257

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

	struct dentry *ignore_gfp_highmem_file;
	struct dentry *ignore_gfp_wait_file;
1258
	struct dentry *min_order_file;
1259 1260 1261 1262 1263

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1264 1265
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1266
	.min_order = 1,
1267 1268 1269 1270 1271 1272 1273 1274 1275 1276
};

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)
{
1277 1278
	if (order < fail_page_alloc.min_order)
		return 0;
1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309
	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);
1310 1311 1312
	fail_page_alloc.min_order_file =
		debugfs_create_u32("min-order", mode, dir,
				   &fail_page_alloc.min_order);
1313 1314

	if (!fail_page_alloc.ignore_gfp_wait_file ||
1315 1316
            !fail_page_alloc.ignore_gfp_highmem_file ||
            !fail_page_alloc.min_order_file) {
1317 1318 1319
		err = -ENOMEM;
		debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
		debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1320
		debugfs_remove(fail_page_alloc.min_order_file);
1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339
		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
1340 1341 1342 1343 1344
/*
 * 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
1345
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
1346 1347
{
	/* free_pages my go negative - that's OK */
1348 1349
	long min = mark;
	long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
L
Linus Torvalds 已提交
1350 1351
	int o;

R
Rohit Seth 已提交
1352
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1353
		min -= min / 2;
R
Rohit Seth 已提交
1354
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371
		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;
}

1372 1373 1374 1375 1376 1377
#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
1378
 * that have to skip over a lot of full or unallowed zones.
1379 1380 1381
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1382
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403
 *
 * 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
1404
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1405 1406 1407 1408 1409 1410
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1411
					&node_states[N_HIGH_MEMORY];
1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436
	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.
 */
1437
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1438 1439 1440 1441 1442 1443 1444 1445 1446 1447
						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;

1448
	i = z - zonelist->_zonerefs;
1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459
	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.
 */
1460
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1461 1462 1463 1464 1465 1466 1467 1468
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

1469
	i = z - zonelist->_zonerefs;
1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

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

1481
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1482 1483 1484 1485 1486
				nodemask_t *allowednodes)
{
	return 1;
}

1487
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1488 1489 1490 1491
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1492
/*
1493
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1494 1495 1496
 * a page.
 */
static struct page *
1497
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1498
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1499
		struct zone *preferred_zone, int migratetype)
M
Martin Hicks 已提交
1500
{
1501
	struct zoneref *z;
R
Rohit Seth 已提交
1502
	struct page *page = NULL;
1503
	int classzone_idx;
1504
	struct zone *zone;
1505 1506 1507
	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 */
1508

1509
	classzone_idx = zone_idx(preferred_zone);
1510
zonelist_scan:
R
Rohit Seth 已提交
1511
	/*
1512
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1513 1514
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1515 1516
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1517 1518 1519
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1520
		if ((alloc_flags & ALLOC_CPUSET) &&
1521
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1522
				goto try_next_zone;
R
Rohit Seth 已提交
1523

1524
		BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
R
Rohit Seth 已提交
1525
		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1526
			unsigned long mark;
1527 1528
			int ret;

1529
			mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548
			if (zone_watermark_ok(zone, order, mark,
				    classzone_idx, alloc_flags))
				goto try_this_zone;

			if (zone_reclaim_mode == 0)
				goto this_zone_full;

			ret = zone_reclaim(zone, gfp_mask, order);
			switch (ret) {
			case ZONE_RECLAIM_NOSCAN:
				/* did not scan */
				goto try_next_zone;
			case ZONE_RECLAIM_FULL:
				/* scanned but unreclaimable */
				goto this_zone_full;
			default:
				/* did we reclaim enough */
				if (!zone_watermark_ok(zone, order, mark,
						classzone_idx, alloc_flags))
1549
					goto this_zone_full;
1550
			}
R
Rohit Seth 已提交
1551 1552
		}

1553
try_this_zone:
1554 1555
		page = buffered_rmqueue(preferred_zone, zone, order,
						gfp_mask, migratetype);
1556
		if (page)
R
Rohit Seth 已提交
1557
			break;
1558 1559 1560 1561
this_zone_full:
		if (NUMA_BUILD)
			zlc_mark_zone_full(zonelist, z);
try_next_zone:
1562
		if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1563 1564 1565 1566
			/*
			 * we do zlc_setup after the first zone is tried but only
			 * if there are multiple nodes make it worthwhile
			 */
1567 1568 1569 1570
			allowednodes = zlc_setup(zonelist, alloc_flags);
			zlc_active = 1;
			did_zlc_setup = 1;
		}
1571
	}
1572 1573 1574 1575 1576 1577

	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
1578
	return page;
M
Martin Hicks 已提交
1579 1580
}

1581 1582 1583
static inline int
should_alloc_retry(gfp_t gfp_mask, unsigned int order,
				unsigned long pages_reclaimed)
L
Linus Torvalds 已提交
1584
{
1585 1586 1587
	/* Do not loop if specifically requested */
	if (gfp_mask & __GFP_NORETRY)
		return 0;
L
Linus Torvalds 已提交
1588

1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605
	/*
	 * 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;
1606

1607 1608 1609 1610 1611 1612
	/*
	 * 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
1613

1614 1615
	return 0;
}
1616

1617 1618 1619
static inline struct page *
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1620 1621
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1622 1623 1624 1625 1626 1627
{
	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
1628 1629
		return NULL;
	}
1630

1631 1632 1633 1634 1635 1636 1637
	/*
	 * 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,
1638
		ALLOC_WMARK_HIGH|ALLOC_CPUSET,
1639
		preferred_zone, migratetype);
R
Rohit Seth 已提交
1640
	if (page)
1641 1642 1643
		goto out;

	/* The OOM killer will not help higher order allocs */
1644
	if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_NOFAIL))
1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658
		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,
1659
	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1660
	int migratetype, unsigned long *did_some_progress)
1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687
{
	struct page *page = NULL;
	struct reclaim_state reclaim_state;
	struct task_struct *p = current;

	cond_resched();

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

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

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

	cond_resched();

	if (order != 0)
		drain_all_pages();

	if (likely(*did_some_progress))
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1688
					zonelist, high_zoneidx,
1689 1690
					alloc_flags, preferred_zone,
					migratetype);
1691 1692 1693
	return page;
}

L
Linus Torvalds 已提交
1694
/*
1695 1696
 * This is called in the allocator slow-path if the allocation request is of
 * sufficient urgency to ignore watermarks and take other desperate measures
L
Linus Torvalds 已提交
1697
 */
1698 1699 1700
static inline struct page *
__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1701 1702
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1703 1704 1705 1706 1707
{
	struct page *page;

	do {
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1708
			zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
1709
			preferred_zone, migratetype);
1710 1711

		if (!page && gfp_mask & __GFP_NOFAIL)
1712
			congestion_wait(BLK_RW_ASYNC, HZ/50);
1713 1714 1715 1716 1717 1718 1719 1720
	} while (!page && (gfp_mask & __GFP_NOFAIL));

	return page;
}

static inline
void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
						enum zone_type high_zoneidx)
L
Linus Torvalds 已提交
1721
{
1722 1723
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
1724

1725 1726 1727
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
		wakeup_kswapd(zone, order);
}
1728

1729 1730 1731 1732 1733 1734
static inline int
gfp_to_alloc_flags(gfp_t gfp_mask)
{
	struct task_struct *p = current;
	int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
	const gfp_t wait = gfp_mask & __GFP_WAIT;
L
Linus Torvalds 已提交
1735

1736 1737
	/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
	BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH);
1738

1739 1740 1741 1742 1743 1744
	/*
	 * 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).
	 */
1745
	alloc_flags |= (gfp_mask & __GFP_HIGH);
L
Linus Torvalds 已提交
1746

1747 1748
	if (!wait) {
		alloc_flags |= ALLOC_HARDER;
1749
		/*
1750 1751
		 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
		 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1752
		 */
1753 1754 1755 1756 1757 1758 1759 1760 1761
		alloc_flags &= ~ALLOC_CPUSET;
	} else if (unlikely(rt_task(p)))
		alloc_flags |= ALLOC_HARDER;

	if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
		if (!in_interrupt() &&
		    ((p->flags & PF_MEMALLOC) ||
		     unlikely(test_thread_flag(TIF_MEMDIE))))
			alloc_flags |= ALLOC_NO_WATERMARKS;
L
Linus Torvalds 已提交
1762
	}
1763

1764 1765 1766
	return alloc_flags;
}

1767 1768 1769
static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1770 1771
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1772 1773 1774 1775 1776 1777 1778
{
	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
1779

1780 1781 1782 1783 1784 1785
	/*
	 * In the slowpath, we sanity check order to avoid ever trying to
	 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
	 * be using allocators in order of preference for an area that is
	 * too large.
	 */
1786 1787
	if (order >= MAX_ORDER) {
		WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
1788
		return NULL;
1789
	}
L
Linus Torvalds 已提交
1790

1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801
	/*
	 * 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;

1802
	wake_all_kswapd(order, zonelist, high_zoneidx);
L
Linus Torvalds 已提交
1803

1804
restart:
1805
	/*
R
Rohit Seth 已提交
1806 1807 1808
	 * 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.
1809
	 */
1810
	alloc_flags = gfp_to_alloc_flags(gfp_mask);
L
Linus Torvalds 已提交
1811

1812
	/* This is the last chance, in general, before the goto nopage. */
1813
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1814 1815
			high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
			preferred_zone, migratetype);
R
Rohit Seth 已提交
1816 1817
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1818

1819
rebalance:
1820
	/* Allocate without watermarks if the context allows */
1821 1822 1823 1824 1825 1826
	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
1827 1828 1829 1830 1831 1832
	}

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

1833 1834 1835 1836
	/* Avoid recursion of direct reclaim */
	if (p->flags & PF_MEMALLOC)
		goto nopage;

1837 1838 1839 1840
	/* Avoid allocations with no watermarks from looping endlessly */
	if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
		goto nopage;

1841 1842 1843 1844
	/* Try direct reclaim and then allocating */
	page = __alloc_pages_direct_reclaim(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
1845
					alloc_flags, preferred_zone,
1846
					migratetype, &did_some_progress);
1847 1848
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1849

1850
	/*
1851 1852
	 * If we failed to make any progress reclaiming, then we are
	 * running out of options and have to consider going OOM
1853
	 */
1854 1855
	if (!did_some_progress) {
		if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1856 1857
			if (oom_killer_disabled)
				goto nopage;
1858 1859
			page = __alloc_pages_may_oom(gfp_mask, order,
					zonelist, high_zoneidx,
1860 1861
					nodemask, preferred_zone,
					migratetype);
1862 1863
			if (page)
				goto got_pg;
L
Linus Torvalds 已提交
1864

1865
			/*
1866 1867 1868 1869
			 * The OOM killer does not trigger for high-order
			 * ~__GFP_NOFAIL allocations so if no progress is being
			 * made, there are no other options and retrying is
			 * unlikely to help.
1870
			 */
1871 1872
			if (order > PAGE_ALLOC_COSTLY_ORDER &&
						!(gfp_mask & __GFP_NOFAIL))
1873
				goto nopage;
1874

1875 1876
			goto restart;
		}
L
Linus Torvalds 已提交
1877 1878
	}

1879
	/* Check if we should retry the allocation */
1880
	pages_reclaimed += did_some_progress;
1881 1882
	if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
		/* Wait for some write requests to complete then retry */
1883
		congestion_wait(BLK_RW_ASYNC, HZ/50);
L
Linus Torvalds 已提交
1884 1885 1886 1887 1888 1889 1890 1891 1892
		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
1893
		show_mem();
L
Linus Torvalds 已提交
1894
	}
1895
	return page;
L
Linus Torvalds 已提交
1896
got_pg:
1897 1898
	if (kmemcheck_enabled)
		kmemcheck_pagealloc_alloc(page, order, gfp_mask);
L
Linus Torvalds 已提交
1899
	return page;
1900

L
Linus Torvalds 已提交
1901
}
1902 1903 1904 1905 1906 1907 1908 1909 1910

/*
 * 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);
1911
	struct zone *preferred_zone;
1912
	struct page *page;
1913
	int migratetype = allocflags_to_migratetype(gfp_mask);
1914

1915 1916
	gfp_mask &= gfp_allowed_mask;

1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931
	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;

1932 1933 1934 1935 1936 1937
	/* 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 */
1938
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
1939
			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
1940
			preferred_zone, migratetype);
1941 1942
	if (unlikely(!page))
		page = __alloc_pages_slowpath(gfp_mask, order,
1943
				zonelist, high_zoneidx, nodemask,
1944
				preferred_zone, migratetype);
1945

1946
	trace_mm_page_alloc(page, order, gfp_mask, migratetype);
1947
	return page;
L
Linus Torvalds 已提交
1948
}
1949
EXPORT_SYMBOL(__alloc_pages_nodemask);
L
Linus Torvalds 已提交
1950 1951 1952 1953

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
1954
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
1955
{
1956 1957 1958 1959 1960 1961 1962 1963
	struct page *page;

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

L
Linus Torvalds 已提交
1964 1965 1966 1967 1968 1969 1970
	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
1971
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
1972
{
1973
	return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
L
Linus Torvalds 已提交
1974 1975 1976 1977 1978 1979 1980
}
EXPORT_SYMBOL(get_zeroed_page);

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

1981 1982
	while (--i >= 0) {
		trace_mm_pagevec_free(pvec->pages[i], pvec->cold);
L
Linus Torvalds 已提交
1983
		free_hot_cold_page(pvec->pages[i], pvec->cold);
1984
	}
L
Linus Torvalds 已提交
1985 1986
}

H
Harvey Harrison 已提交
1987
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
1988
{
N
Nick Piggin 已提交
1989
	if (put_page_testzero(page)) {
1990
		trace_mm_page_free_direct(page, order);
L
Linus Torvalds 已提交
1991 1992 1993 1994 1995 1996 1997 1998 1999
		if (order == 0)
			free_hot_page(page);
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
2000
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
2001 2002
{
	if (addr != 0) {
N
Nick Piggin 已提交
2003
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
2004 2005 2006 2007 2008 2009
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032
/**
 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
 * @size: the number of bytes to allocate
 * @gfp_mask: GFP flags for the allocation
 *
 * This function is similar to alloc_pages(), except that it allocates the
 * minimum number of pages to satisfy the request.  alloc_pages() can only
 * allocate memory in power-of-two pages.
 *
 * This function is also limited by MAX_ORDER.
 *
 * Memory allocated by this function must be released by free_pages_exact().
 */
void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
{
	unsigned int order = get_order(size);
	unsigned long addr;

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

K
Kevin Cernekee 已提交
2033
		split_page(virt_to_page((void *)addr), order);
2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062
		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
2063 2064
static unsigned int nr_free_zone_pages(int offset)
{
2065
	struct zoneref *z;
2066 2067
	struct zone *zone;

2068
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
2069 2070
	unsigned int sum = 0;

2071
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
2072

2073
	for_each_zone_zonelist(zone, z, zonelist, offset) {
2074
		unsigned long size = zone->present_pages;
2075
		unsigned long high = high_wmark_pages(zone);
2076 2077
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
2078 2079 2080 2081 2082 2083 2084 2085 2086 2087
	}

	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
2088
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
2089
}
2090
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
2091 2092 2093 2094 2095 2096

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
2097
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
2098
}
2099 2100

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
2101
{
2102
	if (NUMA_BUILD)
2103
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
2104 2105 2106 2107 2108 2109
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
2110
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124
	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;
2125
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
2126
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2127
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2128 2129
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
2130 2131 2132 2133
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146
	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)
{
2147
	int cpu;
L
Linus Torvalds 已提交
2148 2149
	struct zone *zone;

2150
	for_each_populated_zone(zone) {
2151 2152
		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
2153

2154
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
2155 2156
			struct per_cpu_pageset *pageset;

2157
			pageset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
2158

2159 2160 2161
			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
2162 2163 2164
		}
	}

K
KOSAKI Motohiro 已提交
2165 2166
	printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
		" active_file:%lu inactive_file:%lu isolated_file:%lu\n"
L
Lee Schermerhorn 已提交
2167
		" unevictable:%lu"
2168
		" dirty:%lu writeback:%lu unstable:%lu buffer:%lu\n"
2169
		" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2170
		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2171 2172
		global_page_state(NR_ACTIVE_ANON),
		global_page_state(NR_INACTIVE_ANON),
K
KOSAKI Motohiro 已提交
2173 2174
		global_page_state(NR_ISOLATED_ANON),
		global_page_state(NR_ACTIVE_FILE),
2175
		global_page_state(NR_INACTIVE_FILE),
K
KOSAKI Motohiro 已提交
2176
		global_page_state(NR_ISOLATED_FILE),
L
Lee Schermerhorn 已提交
2177
		global_page_state(NR_UNEVICTABLE),
2178
		global_page_state(NR_FILE_DIRTY),
2179
		global_page_state(NR_WRITEBACK),
2180
		global_page_state(NR_UNSTABLE_NFS),
2181
		nr_blockdev_pages(),
2182
		global_page_state(NR_FREE_PAGES),
2183 2184
		global_page_state(NR_SLAB_RECLAIMABLE),
		global_page_state(NR_SLAB_UNRECLAIMABLE),
2185
		global_page_state(NR_FILE_MAPPED),
2186
		global_page_state(NR_SHMEM),
2187 2188
		global_page_state(NR_PAGETABLE),
		global_page_state(NR_BOUNCE));
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2190
	for_each_populated_zone(zone) {
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		int i;

		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
2199 2200 2201 2202
			" active_anon:%lukB"
			" inactive_anon:%lukB"
			" active_file:%lukB"
			" inactive_file:%lukB"
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			" unevictable:%lukB"
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			" isolated(anon):%lukB"
			" isolated(file):%lukB"
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			" present:%lukB"
2207 2208 2209 2210
			" mlocked:%lukB"
			" dirty:%lukB"
			" writeback:%lukB"
			" mapped:%lukB"
2211
			" shmem:%lukB"
2212 2213
			" slab_reclaimable:%lukB"
			" slab_unreclaimable:%lukB"
2214
			" kernel_stack:%lukB"
2215 2216 2217 2218
			" pagetables:%lukB"
			" unstable:%lukB"
			" bounce:%lukB"
			" writeback_tmp:%lukB"
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			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
2223
			K(zone_page_state(zone, NR_FREE_PAGES)),
2224 2225 2226
			K(min_wmark_pages(zone)),
			K(low_wmark_pages(zone)),
			K(high_wmark_pages(zone)),
2227 2228 2229 2230
			K(zone_page_state(zone, NR_ACTIVE_ANON)),
			K(zone_page_state(zone, NR_INACTIVE_ANON)),
			K(zone_page_state(zone, NR_ACTIVE_FILE)),
			K(zone_page_state(zone, NR_INACTIVE_FILE)),
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			K(zone_page_state(zone, NR_UNEVICTABLE)),
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			K(zone_page_state(zone, NR_ISOLATED_ANON)),
			K(zone_page_state(zone, NR_ISOLATED_FILE)),
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			K(zone->present_pages),
2235 2236 2237 2238
			K(zone_page_state(zone, NR_MLOCK)),
			K(zone_page_state(zone, NR_FILE_DIRTY)),
			K(zone_page_state(zone, NR_WRITEBACK)),
			K(zone_page_state(zone, NR_FILE_MAPPED)),
2239
			K(zone_page_state(zone, NR_SHMEM)),
2240 2241
			K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
			K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
2242 2243
			zone_page_state(zone, NR_KERNEL_STACK) *
				THREAD_SIZE / 1024,
2244 2245 2246 2247
			K(zone_page_state(zone, NR_PAGETABLE)),
			K(zone_page_state(zone, NR_UNSTABLE_NFS)),
			K(zone_page_state(zone, NR_BOUNCE)),
			K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
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			zone->pages_scanned,
2249
			(zone_is_all_unreclaimable(zone) ? "yes" : "no")
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			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

2257
	for_each_populated_zone(zone) {
2258
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
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		show_node(zone);
		printk("%s: ", zone->name);

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
2265 2266
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
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		}
		spin_unlock_irqrestore(&zone->lock, flags);
2269 2270
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
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		printk("= %lukB\n", K(total));
	}

2274 2275
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

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	show_swap_cache_info();
}

2279 2280 2281 2282 2283 2284
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
{
	zoneref->zone = zone;
	zoneref->zone_idx = zone_idx(zone);
}

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/*
 * Builds allocation fallback zone lists.
2287 2288
 *
 * Add all populated zones of a node to the zonelist.
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 */
2290 2291
static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
				int nr_zones, enum zone_type zone_type)
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{
2293 2294
	struct zone *zone;

2295
	BUG_ON(zone_type >= MAX_NR_ZONES);
2296
	zone_type++;
2297 2298

	do {
2299
		zone_type--;
2300
		zone = pgdat->node_zones + zone_type;
2301
		if (populated_zone(zone)) {
2302 2303
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
2304
			check_highest_zone(zone_type);
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		}
2306

2307
	} while (zone_type);
2308
	return nr_zones;
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}

2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331

/*
 *  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
2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403
/* 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;
}


2404
#define MAX_NODE_LOAD (nr_online_nodes)
2405 2406
static int node_load[MAX_NUMNODES];

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/**
2408
 * find_next_best_node - find the next node that should appear in a given node's fallback list
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 * @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.
 */
2421
static int find_next_best_node(int node, nodemask_t *used_node_mask)
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{
2423
	int n, val;
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	int min_val = INT_MAX;
	int best_node = -1;
2426
	const struct cpumask *tmp = cpumask_of_node(0);
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2428 2429 2430 2431 2432
	/* 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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2434
	for_each_node_state(n, N_HIGH_MEMORY) {
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		/* 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);

2443 2444 2445
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

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		/* Give preference to headless and unused nodes */
2447 2448
		tmp = cpumask_of_node(n);
		if (!cpumask_empty(tmp))
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			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;
}

2467 2468 2469 2470 2471 2472 2473

/*
 * 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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{
2475
	int j;
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	struct zonelist *zonelist;
2477

2478
	zonelist = &pgdat->node_zonelists[0];
2479
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2480 2481 2482
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
2483 2484
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2485 2486
}

2487 2488 2489 2490 2491 2492 2493 2494
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

2495 2496
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2497 2498
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2499 2500
}

2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515
/*
 * 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;

2516 2517 2518 2519 2520 2521 2522
	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)) {
2523 2524
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
2525
				check_highest_zone(zone_type);
2526 2527 2528
			}
		}
	}
2529 2530
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565
}

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.
         */
2566 2567
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598
	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;
2600 2601 2602
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
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2603 2604

	/* initialize zonelists */
2605
	for (i = 0; i < MAX_ZONELISTS; i++) {
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		zonelist = pgdat->node_zonelists + i;
2607 2608
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
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2609 2610 2611 2612
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
2613
	load = nr_online_nodes;
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2614 2615
	prev_node = local_node;
	nodes_clear(used_mask);
2616 2617 2618 2619

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

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	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2621 2622 2623 2624 2625 2626 2627 2628 2629
		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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		/*
		 * 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.
		 */
2635
		if (distance != node_distance(local_node, prev_node))
2636 2637
			node_load[node] = load;

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2638 2639
		prev_node = node;
		load--;
2640 2641 2642 2643 2644
		if (order == ZONELIST_ORDER_NODE)
			build_zonelists_in_node_order(pgdat, node);
		else
			node_order[j++] = node;	/* remember order */
	}
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2646 2647 2648
	if (order == ZONELIST_ORDER_ZONE) {
		/* calculate node order -- i.e., DMA last! */
		build_zonelists_in_zone_order(pgdat, j);
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	}
2650 2651

	build_thisnode_zonelists(pgdat);
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2652 2653
}

2654
/* Construct the zonelist performance cache - see further mmzone.h */
2655
static void build_zonelist_cache(pg_data_t *pgdat)
2656
{
2657 2658
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
2659
	struct zoneref *z;
2660

2661 2662 2663
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2664 2665
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2666 2667
}

2668

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#else	/* CONFIG_NUMA */

2671 2672 2673 2674 2675 2676
static void set_zonelist_order(void)
{
	current_zonelist_order = ZONELIST_ORDER_ZONE;
}

static void build_zonelists(pg_data_t *pgdat)
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{
2678
	int node, local_node;
2679 2680
	enum zone_type j;
	struct zonelist *zonelist;
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2681 2682 2683

	local_node = pgdat->node_id;

2684 2685
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
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2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699
	/*
	 * 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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	}
2701 2702 2703 2704 2705 2706 2707
	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);
	}

2708 2709
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
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}

2712
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2713
static void build_zonelist_cache(pg_data_t *pgdat)
2714
{
2715
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
2716 2717
}

L
Linus Torvalds 已提交
2718 2719
#endif	/* CONFIG_NUMA */

2720
/* return values int ....just for stop_machine() */
2721
static int __build_all_zonelists(void *dummy)
L
Linus Torvalds 已提交
2722
{
2723
	int nid;
2724

2725 2726 2727
#ifdef CONFIG_NUMA
	memset(node_load, 0, sizeof(node_load));
#endif
2728
	for_each_online_node(nid) {
2729 2730 2731 2732
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
2733
	}
2734 2735 2736
	return 0;
}

2737
void build_all_zonelists(void)
2738
{
2739 2740
	set_zonelist_order();

2741
	if (system_state == SYSTEM_BOOTING) {
2742
		__build_all_zonelists(NULL);
2743
		mminit_verify_zonelist();
2744 2745
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
2746
		/* we have to stop all cpus to guarantee there is no user
2747
		   of zonelist */
2748
		stop_machine(__build_all_zonelists, NULL, NULL);
2749 2750
		/* cpuset refresh routine should be here */
	}
2751
	vm_total_pages = nr_free_pagecache_pages();
2752 2753 2754 2755 2756 2757 2758
	/*
	 * 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
	 */
2759
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2760 2761 2762 2763 2764 2765
		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",
2766
			nr_online_nodes,
2767
			zonelist_order_name[current_zonelist_order],
2768
			page_group_by_mobility_disabled ? "off" : "on",
2769 2770 2771 2772
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
L
Linus Torvalds 已提交
2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787
}

/*
 * 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

2788
#ifndef CONFIG_MEMORY_HOTPLUG
2789
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806
{
	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);
}
2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829
#else
/*
 * A zone's size might be changed by hot-add, so it is not possible to determine
 * a suitable size for its wait_table.  So we use the maximum size now.
 *
 * The max wait table size = 4096 x sizeof(wait_queue_head_t).   ie:
 *
 *    i386 (preemption config)    : 4096 x 16 = 64Kbyte.
 *    ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
 *    ia64, x86-64 (preemption)   : 4096 x 24 = 96Kbyte.
 *
 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
 * or more by the traditional way. (See above).  It equals:
 *
 *    i386, x86-64, powerpc(4K page size) : =  ( 2G + 1M)byte.
 *    ia64(16K page size)                 : =  ( 8G + 4M)byte.
 *    powerpc (64K page size)             : =  (32G +16M)byte.
 */
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
{
	return 4096UL;
}
#endif
L
Linus Torvalds 已提交
2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842

/*
 * 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))

2843
/*
2844
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2845 2846
 * 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
2847 2848 2849 2850 2851 2852 2853
 * 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;
2854 2855
	unsigned long block_migratetype;
	int reserve;
2856 2857 2858 2859

	/* 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;
2860
	reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
2861
							pageblock_order;
2862

2863 2864 2865 2866 2867 2868 2869 2870 2871
	/*
	 * Reserve blocks are generally in place to help high-order atomic
	 * allocations that are short-lived. A min_free_kbytes value that
	 * would result in more than 2 reserve blocks for atomic allocations
	 * is assumed to be in place to help anti-fragmentation for the
	 * future allocation of hugepages at runtime.
	 */
	reserve = min(2, reserve);

2872
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2873 2874 2875 2876
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

2877 2878 2879 2880
		/* Watch out for overlapping nodes */
		if (page_to_nid(page) != zone_to_nid(zone))
			continue;

2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910
		/* 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
2911

L
Linus Torvalds 已提交
2912 2913 2914 2915 2916
/*
 * 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.
 */
2917
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
2918
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
2919 2920
{
	struct page *page;
A
Andy Whitcroft 已提交
2921 2922
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
2923
	struct zone *z;
L
Linus Torvalds 已提交
2924

2925 2926 2927
	if (highest_memmap_pfn < end_pfn - 1)
		highest_memmap_pfn = end_pfn - 1;

2928
	z = &NODE_DATA(nid)->node_zones[zone];
2929
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940
		/*
		 * 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
2941 2942
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
2943
		mminit_verify_page_links(page, zone, nid, pfn);
2944
		init_page_count(page);
L
Linus Torvalds 已提交
2945 2946
		reset_page_mapcount(page);
		SetPageReserved(page);
2947 2948 2949 2950 2951
		/*
		 * 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
2952 2953 2954
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
2955 2956 2957 2958 2959
		 *
		 * 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.
2960
		 */
2961 2962 2963
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
2964
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2965

L
Linus Torvalds 已提交
2966 2967 2968 2969
		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))
2970
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
2971 2972 2973 2974
#endif
	}
}

2975
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
2976
{
2977 2978 2979
	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
2980 2981 2982 2983 2984 2985
		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
2986
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
2987 2988
#endif

2989
static int zone_batchsize(struct zone *zone)
2990
{
2991
#ifdef CONFIG_MMU
2992 2993 2994 2995
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
2996
	 * size of the zone.  But no more than 1/2 of a meg.
2997 2998 2999 3000
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
3001 3002
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
3003 3004 3005 3006 3007
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
3008 3009 3010
	 * 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.
3011
	 *
3012 3013 3014 3015
	 * 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.
3016
	 */
3017
	batch = rounddown_pow_of_two(batch + batch/2) - 1;
3018

3019
	return batch;
3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036

#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
3037 3038
}

A
Adrian Bunk 已提交
3039
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3040 3041
{
	struct per_cpu_pages *pcp;
3042
	int migratetype;
3043

3044 3045
	memset(p, 0, sizeof(*p));

3046
	pcp = &p->pcp;
3047 3048 3049
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
3050 3051
	for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
		INIT_LIST_HEAD(&pcp->lists[migratetype]);
3052 3053
}

3054 3055 3056 3057 3058 3059 3060 3061 3062 3063
/*
 * 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;

3064
	pcp = &p->pcp;
3065 3066 3067 3068 3069 3070 3071
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}


3072 3073
#ifdef CONFIG_NUMA
/*
3074 3075 3076 3077 3078 3079 3080
 * 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.
3081 3082 3083 3084 3085 3086 3087 3088
 *
 * 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.
3089
 */
3090
static struct per_cpu_pageset boot_pageset[NR_CPUS];
3091 3092 3093

/*
 * Dynamically allocate memory for the
3094 3095
 * per cpu pageset array in struct zone.
 */
3096
static int __cpuinit process_zones(int cpu)
3097 3098
{
	struct zone *zone, *dzone;
3099 3100 3101
	int node = cpu_to_node(cpu);

	node_set_state(node, N_CPU);	/* this node has a cpu */
3102

3103
	for_each_populated_zone(zone) {
N
Nick Piggin 已提交
3104
		zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
3105
					 GFP_KERNEL, node);
N
Nick Piggin 已提交
3106
		if (!zone_pcp(zone, cpu))
3107 3108
			goto bad;

N
Nick Piggin 已提交
3109
		setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
3110 3111 3112 3113

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(zone_pcp(zone, cpu),
			 	(zone->present_pages / percpu_pagelist_fraction));
3114 3115 3116 3117 3118
	}

	return 0;
bad:
	for_each_zone(dzone) {
3119 3120
		if (!populated_zone(dzone))
			continue;
3121 3122
		if (dzone == zone)
			break;
N
Nick Piggin 已提交
3123
		kfree(zone_pcp(dzone, cpu));
3124
		zone_pcp(dzone, cpu) = &boot_pageset[cpu];
3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135
	}
	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);

3136 3137 3138
		/* Free per_cpu_pageset if it is slab allocated */
		if (pset != &boot_pageset[cpu])
			kfree(pset);
3139
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
3140 3141 3142
	}
}

3143
static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
3144 3145 3146 3147 3148 3149 3150
		unsigned long action,
		void *hcpu)
{
	int cpu = (long)hcpu;
	int ret = NOTIFY_OK;

	switch (action) {
3151
	case CPU_UP_PREPARE:
3152
	case CPU_UP_PREPARE_FROZEN:
3153 3154 3155 3156
		if (process_zones(cpu))
			ret = NOTIFY_BAD;
		break;
	case CPU_UP_CANCELED:
3157
	case CPU_UP_CANCELED_FROZEN:
3158
	case CPU_DEAD:
3159
	case CPU_DEAD_FROZEN:
3160 3161 3162 3163
		free_zone_pagesets(cpu);
		break;
	default:
		break;
3164 3165 3166 3167
	}
	return ret;
}

3168
static struct notifier_block __cpuinitdata pageset_notifier =
3169 3170
	{ &pageset_cpuup_callback, NULL, 0 };

3171
void __init setup_per_cpu_pageset(void)
3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185
{
	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
3186
static noinline __init_refok
3187
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3188 3189 3190
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
3191
	size_t alloc_size;
3192 3193 3194 3195 3196

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
3197 3198 3199 3200
	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);
3201 3202 3203
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

3204
	if (!slab_is_available()) {
3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217
		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.
		 */
3218
		zone->wait_table = vmalloc(alloc_size);
3219 3220 3221
	}
	if (!zone->wait_table)
		return -ENOMEM;
3222

3223
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3224
		init_waitqueue_head(zone->wait_table + i);
3225 3226

	return 0;
3227 3228
}

3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242
static int __zone_pcp_update(void *data)
{
	struct zone *zone = data;
	int cpu;
	unsigned long batch = zone_batchsize(zone), flags;

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

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

		local_irq_save(flags);
3243
		free_pcppages_bulk(zone, pcp->count, pcp);
3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254
		setup_pageset(pset, batch);
		local_irq_restore(flags);
	}
	return 0;
}

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

3255
static __meminit void zone_pcp_init(struct zone *zone)
3256 3257 3258 3259 3260 3261 3262
{
	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
3263
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
3264 3265 3266 3267 3268
		setup_pageset(&boot_pageset[cpu],0);
#else
		setup_pageset(zone_pcp(zone,cpu), batch);
#endif
	}
A
Anton Blanchard 已提交
3269 3270 3271
	if (zone->present_pages)
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%lu\n",
			zone->name, zone->present_pages, batch);
3272 3273
}

3274 3275
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
3276 3277
					unsigned long size,
					enum memmap_context context)
3278 3279
{
	struct pglist_data *pgdat = zone->zone_pgdat;
3280 3281 3282 3283
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
3284 3285 3286 3287
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

3288 3289 3290 3291 3292 3293
	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));

3294
	zone_init_free_lists(zone);
3295 3296

	return 0;
3297 3298
}

3299 3300 3301 3302 3303
#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
 */
3304
static int __meminit first_active_region_index_in_nid(int nid)
3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316
{
	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
3317
 * Note: nid == MAX_NUMNODES returns next region regardless of node
3318
 */
3319
static int __meminit next_active_region_index_in_nid(int index, int nid)
3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334
{
	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
 */
3335
int __meminit __early_pfn_to_nid(unsigned long pfn)
3336 3337 3338 3339 3340 3341 3342 3343 3344 3345
{
	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;
	}
3346 3347
	/* This is a memory hole */
	return -1;
3348 3349 3350
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

3351 3352
int __meminit early_pfn_to_nid(unsigned long pfn)
{
3353 3354 3355 3356 3357 3358 3359
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0)
		return nid;
	/* just returns 0 */
	return 0;
3360 3361
}

3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372
#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
3373

3374 3375 3376 3377 3378 3379 3380
/* 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
3381 3382
 * @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
3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409
 *
 * 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);
	}
}

3410 3411 3412
void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
{
	int i;
3413
	int ret;
3414

3415 3416 3417 3418 3419 3420
	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;
	}
3421
}
3422 3423
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3424
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3425 3426 3427
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
3428
 * function may be used instead of calling memory_present() manually.
3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441
 */
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
3442 3443 3444
 * @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.
3445 3446 3447 3448
 *
 * 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
3449
 * PFNs will be 0.
3450
 */
3451
void __meminit get_pfn_range_for_nid(unsigned int nid,
3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462
			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);
	}

3463
	if (*start_pfn == -1UL)
3464 3465 3466
		*start_pfn = 0;
}

M
Mel Gorman 已提交
3467 3468 3469 3470 3471
/*
 * 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
3472
static void __init find_usable_zone_for_movable(void)
M
Mel Gorman 已提交
3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497
{
	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
3498
static void __meminit adjust_zone_range_for_zone_movable(int nid,
M
Mel Gorman 已提交
3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523
					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;
	}
}

3524 3525 3526 3527
/*
 * 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
3528
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3529 3530 3531 3532 3533 3534 3535 3536 3537 3538
					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
3539 3540 3541
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556

	/* 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,
3557
 * then all holes in the requested range will be accounted for.
3558
 */
A
Adrian Bunk 已提交
3559
static unsigned long __meminit __absent_pages_in_range(int nid,
3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571
				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;

3572 3573
	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);

3574 3575
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
3576
		hole_pages = prev_end_pfn - range_start_pfn;
3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596

	/* 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;
	}

3597 3598
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
3599
		hole_pages += range_end_pfn -
3600 3601
				max(range_start_pfn, prev_end_pfn);

3602 3603 3604 3605 3606 3607 3608 3609
	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
 *
3610
 * It returns the number of pages frames in memory holes within a range.
3611 3612 3613 3614 3615 3616 3617 3618
 */
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
3619
static unsigned long __meminit zone_absent_pages_in_node(int nid,
3620 3621 3622
					unsigned long zone_type,
					unsigned long *ignored)
{
3623 3624 3625 3626 3627 3628 3629 3630 3631
	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
3632 3633 3634
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
3635
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3636
}
3637

3638
#else
P
Paul Mundt 已提交
3639
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3640 3641 3642 3643 3644 3645
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
3646
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3647 3648 3649 3650 3651 3652 3653 3654
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
3655

3656 3657
#endif

3658
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678
		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);
}

3679 3680 3681
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
3682 3683
 * 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
3684 3685 3686 3687 3688 3689 3690
 * 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;

3691 3692
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703
	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;
3704
	if (usemapsize)
3705 3706 3707 3708 3709 3710 3711
		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 */

3712
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3713 3714 3715 3716 3717 3718 3719 3720 3721 3722

/* 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;
}

3723 3724 3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737
/* 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 */

3738 3739 3740 3741 3742 3743 3744 3745 3746 3747
/*
 * 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;
}
3748 3749 3750 3751
#define set_pageblock_order(x)	do {} while (0)

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
3752 3753 3754 3755 3756 3757
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
3758
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3759 3760
		unsigned long *zones_size, unsigned long *zholes_size)
{
3761
	enum zone_type j;
3762
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
3763
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
3764
	int ret;
L
Linus Torvalds 已提交
3765

3766
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
3767 3768 3769
	pgdat->nr_zones = 0;
	init_waitqueue_head(&pgdat->kswapd_wait);
	pgdat->kswapd_max_order = 0;
3770
	pgdat_page_cgroup_init(pgdat);
L
Linus Torvalds 已提交
3771 3772 3773
	
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
3774
		unsigned long size, realsize, memmap_pages;
3775
		enum lru_list l;
L
Linus Torvalds 已提交
3776

3777 3778 3779
		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
3780

3781 3782 3783 3784 3785
		/*
		 * 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
		 */
3786 3787
		memmap_pages =
			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
3788 3789
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
3790 3791 3792 3793
			if (memmap_pages)
				printk(KERN_DEBUG
				       "  %s zone: %lu pages used for memmap\n",
				       zone_names[j], memmap_pages);
3794 3795 3796 3797 3798
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

3799 3800
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
3801
			realsize -= dma_reserve;
Y
Yinghai Lu 已提交
3802
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
3803
					zone_names[0], dma_reserve);
3804 3805
		}

3806
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
3807 3808 3809 3810 3811
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
3812
#ifdef CONFIG_NUMA
3813
		zone->node = nid;
3814
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3815
						/ 100;
3816
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3817
#endif
L
Linus Torvalds 已提交
3818 3819 3820
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
3821
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
3822 3823
		zone->zone_pgdat = pgdat;

3824
		zone->prev_priority = DEF_PRIORITY;
L
Linus Torvalds 已提交
3825

3826
		zone_pcp_init(zone);
3827 3828
		for_each_lru(l) {
			INIT_LIST_HEAD(&zone->lru[l].list);
3829
			zone->reclaim_stat.nr_saved_scan[l] = 0;
3830
		}
3831 3832 3833 3834
		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;
3835
		zap_zone_vm_stats(zone);
3836
		zone->flags = 0;
L
Linus Torvalds 已提交
3837 3838 3839
		if (!size)
			continue;

3840
		set_pageblock_order(pageblock_default_order());
3841
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
3842 3843
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
3844
		BUG_ON(ret);
3845
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
3846 3847 3848 3849
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
3850
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
3851 3852 3853 3854 3855
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
3856
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
3857 3858
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
3859
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
3860 3861
		struct page *map;

3862 3863 3864 3865 3866 3867 3868 3869 3870
		/*
		 * 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);
3871 3872 3873
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
3874
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
3875
	}
3876
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
3877 3878 3879
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
3880
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
3881
		mem_map = NODE_DATA(0)->node_mem_map;
3882 3883
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3884
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3885 3886
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
3887
#endif
A
Andy Whitcroft 已提交
3888
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
3889 3890
}

3891 3892
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
3893
{
3894 3895
	pg_data_t *pgdat = NODE_DATA(nid);

L
Linus Torvalds 已提交
3896 3897
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
3898
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
3899 3900

	alloc_node_mem_map(pgdat);
3901 3902 3903 3904 3905
#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
3906 3907 3908 3909

	free_area_init_core(pgdat, zones_size, zholes_size);
}

3910
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
M
Miklos Szeredi 已提交
3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930

#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

3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947
/**
 * 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;

3948 3949 3950 3951 3952
	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);
3953

3954 3955
	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);

3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994
	/* 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;
}

/**
3995
 * remove_active_range - Shrink an existing registered range of PFNs
3996
 * @nid: The node id the range is on that should be shrunk
3997 3998
 * @start_pfn: The new PFN of the range
 * @end_pfn: The new PFN of the range
3999 4000
 *
 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
4001 4002 4003
 * 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.
4004
 */
4005 4006
void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
				unsigned long end_pfn)
4007
{
4008 4009
	int i, j;
	int removed = 0;
4010

4011 4012 4013
	printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
			  nid, start_pfn, end_pfn);

4014
	/* Find the old active region end and shrink */
4015
	for_each_active_range_index_in_nid(i, nid) {
4016 4017
		if (early_node_map[i].start_pfn >= start_pfn &&
		    early_node_map[i].end_pfn <= end_pfn) {
4018
			/* clear it */
4019
			early_node_map[i].start_pfn = 0;
4020 4021 4022 4023
			early_node_map[i].end_pfn = 0;
			removed = 1;
			continue;
		}
4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035
		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;
4036
			continue;
4037
		}
4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056
	}

	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--;
	}
4057 4058 4059 4060
}

/**
 * remove_all_active_ranges - Remove all currently registered regions
4061
 *
4062 4063 4064 4065
 * 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.
 */
4066
void __init remove_all_active_ranges(void)
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
{
	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);
}

4095
/* Find the lowest pfn for a node */
A
Adrian Bunk 已提交
4096
static unsigned long __init find_min_pfn_for_node(int nid)
4097 4098
{
	int i;
4099
	unsigned long min_pfn = ULONG_MAX;
4100

4101 4102
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
4103
		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
4104

4105 4106
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
4107
			"Could not find start_pfn for node %d\n", nid);
4108 4109 4110 4111
		return 0;
	}

	return min_pfn;
4112 4113 4114 4115 4116 4117
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
4118
 * add_active_range().
4119 4120 4121 4122 4123 4124
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

4125 4126 4127 4128 4129
/*
 * 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
4130
static unsigned long __init early_calculate_totalpages(void)
4131 4132 4133 4134
{
	int i;
	unsigned long totalpages = 0;

4135 4136
	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long pages = early_node_map[i].end_pfn -
4137
						early_node_map[i].start_pfn;
4138 4139 4140 4141 4142
		totalpages += pages;
		if (pages)
			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
	}
  	return totalpages;
4143 4144
}

M
Mel Gorman 已提交
4145 4146 4147 4148 4149 4150
/*
 * 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
4151
static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
M
Mel Gorman 已提交
4152 4153 4154 4155
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
4156 4157
	/* save the state before borrow the nodemask */
	nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4158 4159
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
4160

4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178 4179 4180 4181 4182
	/*
	 * 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
4183 4184
	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
	if (!required_kernelcore)
4185
		goto out;
M
Mel Gorman 已提交
4186 4187 4188 4189 4190 4191 4192 4193

	/* 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;
4194
	for_each_node_state(nid, N_HIGH_MEMORY) {
M
Mel Gorman 已提交
4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283
		/*
		 * 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);
4284 4285 4286 4287

out:
	/* restore the node_state */
	node_states[N_HIGH_MEMORY] = saved_node_state;
M
Mel Gorman 已提交
4288 4289
}

4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302 4303
/* 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
}

4304 4305
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
4306
 * @max_zone_pfn: an array of max PFNs for each zone
4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319
 *
 * 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;
4320
	int i;
4321

4322 4323 4324
	/* Sort early_node_map as initialisation assumes it is sorted */
	sort_node_map();

4325 4326 4327 4328 4329 4330 4331 4332
	/* 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
4333 4334
		if (i == ZONE_MOVABLE)
			continue;
4335 4336 4337 4338 4339
		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
4340 4341 4342 4343 4344 4345
	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);
4346 4347 4348

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
M
Mel Gorman 已提交
4349 4350 4351
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
4352
		printk("  %-8s %0#10lx -> %0#10lx\n",
4353 4354 4355
				zone_names[i],
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);
M
Mel Gorman 已提交
4356 4357 4358 4359 4360 4361 4362 4363
	}

	/* 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]);
	}
4364 4365 4366 4367

	/* 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++)
4368
		printk("  %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4369 4370 4371 4372
						early_node_map[i].start_pfn,
						early_node_map[i].end_pfn);

	/* Initialise every node */
4373
	mminit_verify_pageflags_layout();
4374
	setup_nr_node_ids();
4375 4376
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
4377
		free_area_init_node(nid, NULL,
4378
				find_min_pfn_for_node(nid), NULL);
4379 4380 4381 4382 4383

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
4384 4385
	}
}
M
Mel Gorman 已提交
4386

4387
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
4388 4389 4390 4391 4392 4393
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
4394
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
4395

4396
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
4397 4398 4399 4400
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
4401

4402 4403 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419
/*
 * 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
4420
early_param("kernelcore", cmdline_parse_kernelcore);
4421
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
4422

4423 4424
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

4425
/**
4426 4427
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
4428 4429 4430 4431
 *
 * 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
4432 4433 4434
 * 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.
4435 4436 4437 4438 4439 4440
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

4441
#ifndef CONFIG_NEED_MULTIPLE_NODES
4442
struct pglist_data __refdata contig_page_data = { .bdata = &bootmem_node_data[0] };
L
Linus Torvalds 已提交
4443
EXPORT_SYMBOL(contig_page_data);
4444
#endif
L
Linus Torvalds 已提交
4445 4446 4447

void __init free_area_init(unsigned long *zones_size)
{
4448
	free_area_init_node(0, zones_size,
L
Linus Torvalds 已提交
4449 4450 4451 4452 4453 4454 4455 4456
			__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;

4457
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4458 4459 4460 4461 4462 4463 4464 4465
		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.
		 */
4466
		vm_events_fold_cpu(cpu);
4467 4468 4469 4470 4471 4472 4473 4474

		/*
		 * 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.
		 */
4475
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
4476 4477 4478 4479 4480 4481 4482 4483 4484
	}
	return NOTIFY_OK;
}

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

4485 4486 4487 4488 4489 4490 4491 4492
/*
 * 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;
4493
	enum zone_type i, j;
4494 4495 4496 4497 4498 4499 4500 4501 4502 4503 4504 4505

	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];
			}

4506 4507
			/* we treat the high watermark as reserved pages. */
			max += high_wmark_pages(zone);
4508 4509 4510 4511 4512 4513 4514 4515 4516

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

L
Linus Torvalds 已提交
4517 4518 4519 4520 4521 4522 4523 4524 4525
/*
 * 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;
4526
	enum zone_type j, idx;
L
Linus Torvalds 已提交
4527

4528
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
4529 4530 4531 4532 4533 4534
		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;

4535 4536
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
4537 4538
				struct zone *lower_zone;

4539 4540
				idx--;

L
Linus Torvalds 已提交
4541 4542 4543 4544 4545 4546 4547 4548 4549 4550
				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;
			}
		}
	}
4551 4552 4553

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4554 4555
}

4556
/**
4557
 * setup_per_zone_wmarks - called when min_free_kbytes changes
4558
 * or when memory is hot-{added|removed}
4559
 *
4560 4561
 * Ensures that the watermark[min,low,high] values for each zone are set
 * correctly with respect to min_free_kbytes.
L
Linus Torvalds 已提交
4562
 */
4563
void setup_per_zone_wmarks(void)
L
Linus Torvalds 已提交
4564 4565 4566 4567 4568 4569 4570 4571 4572 4573 4574 4575 4576
{
	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) {
4577 4578
		u64 tmp;

4579
		spin_lock_irqsave(&zone->lock, flags);
4580 4581
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
4582 4583
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
4584 4585 4586 4587
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
4588
			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
N
Nick Piggin 已提交
4589 4590
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
Linus Torvalds 已提交
4591 4592 4593 4594 4595 4596 4597 4598
			 */
			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;
4599
			zone->watermark[WMARK_MIN] = min_pages;
L
Linus Torvalds 已提交
4600
		} else {
N
Nick Piggin 已提交
4601 4602
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
4603 4604
			 * proportionate to the zone's size.
			 */
4605
			zone->watermark[WMARK_MIN] = tmp;
L
Linus Torvalds 已提交
4606 4607
		}

4608 4609
		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) + (tmp >> 2);
		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
4610
		setup_zone_migrate_reserve(zone);
4611
		spin_unlock_irqrestore(&zone->lock, flags);
L
Linus Torvalds 已提交
4612
	}
4613 4614 4615

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4616 4617
}

4618
/*
4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629 4630 4631 4632 4633 4634 4635 4636 4637 4638
 * 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
 */
4639
void calculate_zone_inactive_ratio(struct zone *zone)
4640
{
4641
	unsigned int gb, ratio;
4642

4643 4644 4645
	/* Zone size in gigabytes */
	gb = zone->present_pages >> (30 - PAGE_SHIFT);
	if (gb)
4646
		ratio = int_sqrt(10 * gb);
4647 4648
	else
		ratio = 1;
4649

4650 4651
	zone->inactive_ratio = ratio;
}
4652

4653 4654 4655 4656 4657 4658
static void __init setup_per_zone_inactive_ratio(void)
{
	struct zone *zone;

	for_each_zone(zone)
		calculate_zone_inactive_ratio(zone);
4659 4660
}

L
Linus Torvalds 已提交
4661 4662 4663 4664 4665 4666 4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684
/*
 * 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
 */
4685
static int __init init_per_zone_wmark_min(void)
L
Linus Torvalds 已提交
4686 4687 4688 4689 4690 4691 4692 4693 4694 4695
{
	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;
4696
	setup_per_zone_wmarks();
L
Linus Torvalds 已提交
4697
	setup_per_zone_lowmem_reserve();
4698
	setup_per_zone_inactive_ratio();
L
Linus Torvalds 已提交
4699 4700
	return 0;
}
4701
module_init(init_per_zone_wmark_min)
L
Linus Torvalds 已提交
4702 4703 4704 4705 4706 4707 4708 4709 4710 4711

/*
 * 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);
4712
	if (write)
4713
		setup_per_zone_wmarks();
L
Linus Torvalds 已提交
4714 4715 4716
	return 0;
}

4717 4718 4719 4720 4721 4722 4723 4724 4725 4726 4727 4728
#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)
4729
		zone->min_unmapped_pages = (zone->present_pages *
4730 4731 4732
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
4733 4734 4735 4736 4737 4738 4739 4740 4741 4742 4743 4744 4745 4746 4747 4748

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;
}
4749 4750
#endif

L
Linus Torvalds 已提交
4751 4752 4753 4754 4755 4756
/*
 * 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
4757
 * minimum watermarks. The lowmem reserve ratio can only make sense
L
Linus Torvalds 已提交
4758 4759 4760 4761 4762 4763 4764 4765 4766 4767
 * 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;
}

4768 4769 4770 4771 4772 4773 4774 4775 4776 4777 4778 4779 4780 4781 4782 4783
/*
 * 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;
4784
	for_each_populated_zone(zone) {
4785 4786 4787 4788 4789 4790 4791 4792 4793
		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;
}

4794
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
4795 4796 4797 4798 4799 4800 4801 4802 4803 4804 4805 4806 4807 4808 4809 4810 4811 4812 4813 4814 4815 4816 4817 4818 4819 4820 4821 4822 4823 4824 4825 4826 4827 4828

#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
4829
		numentries = nr_kernel_pages;
L
Linus Torvalds 已提交
4830 4831 4832 4833 4834 4835 4836 4837 4838
		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);
4839 4840

		/* Make sure we've got at least a 0-order allocation.. */
4841 4842 4843 4844 4845 4846 4847 4848
		if (unlikely(flags & HASH_SMALL)) {
			/* Makes no sense without HASH_EARLY */
			WARN_ON(!(flags & HASH_EARLY));
			if (!(numentries >> *_hash_shift)) {
				numentries = 1UL << *_hash_shift;
				BUG_ON(!numentries);
			}
		} else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
4849
			numentries = PAGE_SIZE / bucketsize;
L
Linus Torvalds 已提交
4850
	}
4851
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
4852 4853 4854 4855 4856 4857 4858 4859 4860 4861

	/* 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;

4862
	log2qty = ilog2(numentries);
L
Linus Torvalds 已提交
4863 4864 4865 4866

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
4867
			table = alloc_bootmem_nopanic(size);
L
Linus Torvalds 已提交
4868 4869 4870
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
4871 4872
			/*
			 * If bucketsize is not a power-of-two, we may free
4873 4874
			 * some pages at the end of hash table which
			 * alloc_pages_exact() automatically does
4875
			 */
4876
			if (get_order(size) < MAX_ORDER) {
4877
				table = alloc_pages_exact(size, GFP_ATOMIC);
4878 4879
				kmemleak_alloc(table, size, 1, GFP_ATOMIC);
			}
L
Linus Torvalds 已提交
4880 4881 4882 4883 4884 4885
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

4886
	printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
L
Linus Torvalds 已提交
4887 4888
	       tablename,
	       (1U << log2qty),
4889
	       ilog2(size) - PAGE_SHIFT,
L
Linus Torvalds 已提交
4890 4891 4892 4893 4894 4895 4896 4897 4898
	       size);

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

	return table;
}
4899

4900 4901 4902 4903 4904 4905 4906 4907 4908 4909 4910 4911 4912 4913 4914
/* 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);
4915
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4916 4917
#else
	pfn = pfn - zone->zone_start_pfn;
4918
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4919 4920 4921 4922
#endif /* CONFIG_SPARSEMEM */
}

/**
4923
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935 4936 4937 4938 4939 4940 4941 4942 4943 4944 4945
 * @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;
4946

4947 4948 4949 4950
	return flags;
}

/**
4951
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4952 4953 4954 4955 4956 4957 4958 4959 4960 4961 4962 4963 4964 4965 4966 4967 4968
 * @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);
4969 4970
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
4971 4972 4973 4974 4975 4976 4977

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

int set_migratetype_isolate(struct page *page)
{
	struct zone *zone;
	unsigned long flags;
	int ret = -EBUSY;
4990
	int zone_idx;
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	zone = page_zone(page);
4993
	zone_idx = zone_idx(zone);
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	spin_lock_irqsave(&zone->lock, flags);
	/*
	 * In future, more migrate types will be able to be isolation target.
	 */
4998 4999
	if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE &&
	    zone_idx != ZONE_MOVABLE)
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		goto out;
	set_pageblock_migratetype(page, MIGRATE_ISOLATE);
	move_freepages_block(zone, page, MIGRATE_ISOLATE);
	ret = 0;
out:
	spin_unlock_irqrestore(&zone->lock, flags);
	if (!ret)
5007
		drain_all_pages();
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	return ret;
}

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