page_alloc.c 142.0 KB
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/*
 *  linux/mm/page_alloc.c
 *
 *  Manages the free list, the system allocates free pages here.
 *  Note that kmalloc() lives in slab.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *  Swap reorganised 29.12.95, Stephen Tweedie
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *  Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
 *  Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
 *  Zone balancing, Kanoj Sarcar, SGI, Jan 2000
 *  Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
 *          (lots of bits borrowed from Ingo Molnar & Andrew Morton)
 */

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

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

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

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

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

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int min_free_kbytes = 1024;

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

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

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

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int page_group_by_mobility_disabled __read_mostly;

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

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

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bool oom_killer_disabled __read_mostly;

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

	return ret;
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}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	return page + (buddy_idx - page_idx);
}

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

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

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

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

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

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

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

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

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

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

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/*
 * 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);
}

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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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555 556 557 558
		do {
			page = list_entry(list->prev, struct page, lru);
			/* must delete as __free_one_page list manipulates */
			list_del(&page->lru);
559 560 561
			/* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
			__free_one_page(page, zone, 0, page_private(page));
			trace_mm_page_pcpu_drain(page, 0, page_private(page));
562
		} while (--count && --batch_free && !list_empty(list));
L
Linus Torvalds 已提交
563
	}
N
Nick Piggin 已提交
564
	spin_unlock(&zone->lock);
L
Linus Torvalds 已提交
565 566
}

567 568
static void free_one_page(struct zone *zone, struct page *page, int order,
				int migratetype)
L
Linus Torvalds 已提交
569
{
570
	spin_lock(&zone->lock);
571
	zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
572
	zone->pages_scanned = 0;
573 574

	__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
575
	__free_one_page(page, zone, order, migratetype);
576
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
577 578 579 580 581
}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
L
Linus Torvalds 已提交
582
	int i;
583
	int bad = 0;
584
	int wasMlocked = __TestClearPageMlocked(page);
L
Linus Torvalds 已提交
585

586 587
	kmemcheck_free_shadow(page, order);

L
Linus Torvalds 已提交
588
	for (i = 0 ; i < (1 << order) ; ++i)
589 590
		bad += free_pages_check(page + i);
	if (bad)
591 592
		return;

593
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
594
		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
595 596 597
		debug_check_no_obj_freed(page_address(page),
					   PAGE_SIZE << order);
	}
N
Nick Piggin 已提交
598
	arch_free_page(page, order);
N
Nick Piggin 已提交
599
	kernel_map_pages(page, 1 << order, 0);
N
Nick Piggin 已提交
600

N
Nick Piggin 已提交
601
	local_irq_save(flags);
602
	if (unlikely(wasMlocked))
603
		free_page_mlock(page);
604
	__count_vm_events(PGFREE, 1 << order);
605 606
	free_one_page(page_zone(page), page, order,
					get_pageblock_migratetype(page));
N
Nick Piggin 已提交
607
	local_irq_restore(flags);
L
Linus Torvalds 已提交
608 609
}

610 611 612
/*
 * permit the bootmem allocator to evade page validation on high-order frees
 */
613
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
614 615 616 617
{
	if (order == 0) {
		__ClearPageReserved(page);
		set_page_count(page, 0);
618
		set_page_refcounted(page);
N
Nick Piggin 已提交
619
		__free_page(page);
620 621 622
	} else {
		int loop;

N
Nick Piggin 已提交
623
		prefetchw(page);
624 625 626
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

N
Nick Piggin 已提交
627 628
			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
629 630 631 632
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

633
		set_page_refcounted(page);
N
Nick Piggin 已提交
634
		__free_pages(page, order);
635 636 637
	}
}

L
Linus Torvalds 已提交
638 639 640 641 642 643 644 645 646 647 648 649 650 651 652

/*
 * 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
653
static inline void expand(struct zone *zone, struct page *page,
654 655
	int low, int high, struct free_area *area,
	int migratetype)
L
Linus Torvalds 已提交
656 657 658 659 660 661 662
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
663
		VM_BUG_ON(bad_range(zone, &page[size]));
664
		list_add(&page[size].lru, &area->free_list[migratetype]);
L
Linus Torvalds 已提交
665 666 667 668 669 670 671 672
		area->nr_free++;
		set_page_order(&page[size], high);
	}
}

/*
 * This page is about to be returned from the page allocator
 */
673
static inline int check_new_page(struct page *page)
L
Linus Torvalds 已提交
674
{
N
Nick Piggin 已提交
675 676
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
677
		(atomic_read(&page->_count) != 0)  |
678
		(page->flags & PAGE_FLAGS_CHECK_AT_PREP))) {
N
Nick Piggin 已提交
679
		bad_page(page);
680
		return 1;
681
	}
682 683 684 685 686 687 688 689 690 691 692 693
	return 0;
}

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

	for (i = 0; i < (1 << order); i++) {
		struct page *p = page + i;
		if (unlikely(check_new_page(p)))
			return 1;
	}
694

H
Hugh Dickins 已提交
695
	set_page_private(page, 0);
696
	set_page_refcounted(page);
N
Nick Piggin 已提交
697 698

	arch_alloc_page(page, order);
L
Linus Torvalds 已提交
699
	kernel_map_pages(page, 1 << order, 1);
N
Nick Piggin 已提交
700 701 702 703 704 705 706

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

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

707
	return 0;
L
Linus Torvalds 已提交
708 709
}

710 711 712 713
/*
 * Go through the free lists for the given migratetype and remove
 * the smallest available page from the freelists
 */
714 715
static inline
struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740
						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;
}


741 742 743 744 745
/*
 * 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] = {
746 747 748 749
	[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 */
750 751
};

752 753
/*
 * Move the free pages in a range to the free lists of the requested type.
754
 * Note that start_page and end_pages are not aligned on a pageblock
755 756
 * boundary. If alignment is required, use move_freepages_block()
 */
A
Adrian Bunk 已提交
757 758 759
static int move_freepages(struct zone *zone,
			  struct page *start_page, struct page *end_page,
			  int migratetype)
760 761 762
{
	struct page *page;
	unsigned long order;
763
	int pages_moved = 0;
764 765 766 767 768 769 770

#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
771
	 * grouping pages by mobility
772 773 774 775 776
	 */
	BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif

	for (page = start_page; page <= end_page;) {
777 778 779
		/* Make sure we are not inadvertently changing nodes */
		VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));

780 781 782 783 784 785 786 787 788 789 790 791 792 793 794
		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;
795
		pages_moved += 1 << order;
796 797
	}

798
	return pages_moved;
799 800
}

A
Adrian Bunk 已提交
801 802
static int move_freepages_block(struct zone *zone, struct page *page,
				int migratetype)
803 804 805 806 807
{
	unsigned long start_pfn, end_pfn;
	struct page *start_page, *end_page;

	start_pfn = page_to_pfn(page);
808
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
809
	start_page = pfn_to_page(start_pfn);
810 811
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
812 813 814 815 816 817 818 819 820 821

	/* 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);
}

822 823 824 825 826 827 828 829 830 831 832
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;
	}
}

833
/* Remove an element from the buddy allocator from the fallback list */
834 835
static inline struct page *
__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
836 837 838 839 840 841 842 843 844 845 846 847
{
	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];

848 849 850
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
				continue;
M
Mel Gorman 已提交
851

852 853 854 855 856 857 858 859 860
			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--;

			/*
861
			 * If breaking a large block of pages, move all free
862 863 864
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
			 * agressive about taking ownership of free pages
865
			 */
866
			if (unlikely(current_order >= (pageblock_order >> 1)) ||
867 868
					start_migratetype == MIGRATE_RECLAIMABLE ||
					page_group_by_mobility_disabled) {
869 870 871 872 873
				unsigned long pages;
				pages = move_freepages_block(zone, page,
								start_migratetype);

				/* Claim the whole block if over half of it is free */
874 875
				if (pages >= (1 << (pageblock_order-1)) ||
						page_group_by_mobility_disabled)
876 877 878
					set_pageblock_migratetype(page,
								start_migratetype);

879
				migratetype = start_migratetype;
880
			}
881 882 883 884 885

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

886 887 888
			/* Take ownership for orders >= pageblock_order */
			if (current_order >= pageblock_order)
				change_pageblock_range(page, current_order,
889 890 891
							start_migratetype);

			expand(zone, page, order, current_order, area, migratetype);
892 893 894 895

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

896 897 898 899
			return page;
		}
	}

900
	return NULL;
901 902
}

903
/*
L
Linus Torvalds 已提交
904 905 906
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
907 908
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
L
Linus Torvalds 已提交
909 910 911
{
	struct page *page;

912
retry_reserve:
913
	page = __rmqueue_smallest(zone, order, migratetype);
914

915
	if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
916
		page = __rmqueue_fallback(zone, order, migratetype);
917

918 919 920 921 922 923 924 925 926 927 928
		/*
		 * 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;
		}
	}

929
	trace_mm_page_alloc_zone_locked(page, order, migratetype);
930
	return page;
L
Linus Torvalds 已提交
931 932 933 934 935 936 937 938
}

/* 
 * 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, 
939
			unsigned long count, struct list_head *list,
940
			int migratetype, int cold)
L
Linus Torvalds 已提交
941 942 943
{
	int i;
	
N
Nick Piggin 已提交
944
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
945
	for (i = 0; i < count; ++i) {
946
		struct page *page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
947
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
948
			break;
949 950 951 952 953 954 955 956 957 958

		/*
		 * 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.
		 */
959 960 961 962
		if (likely(cold == 0))
			list_add(&page->lru, list);
		else
			list_add_tail(&page->lru, list);
963
		set_page_private(page, migratetype);
964
		list = &page->lru;
L
Linus Torvalds 已提交
965
	}
966
	__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
N
Nick Piggin 已提交
967
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
968
	return i;
L
Linus Torvalds 已提交
969 970
}

971
#ifdef CONFIG_NUMA
972
/*
973 974 975 976
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
977 978
 * Note that this function must be called with the thread pinned to
 * a single processor.
979
 */
980
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
981 982
{
	unsigned long flags;
983
	int to_drain;
984

985 986 987 988 989
	local_irq_save(flags);
	if (pcp->count >= pcp->batch)
		to_drain = pcp->batch;
	else
		to_drain = pcp->count;
990
	free_pcppages_bulk(zone, to_drain, pcp);
991 992
	pcp->count -= to_drain;
	local_irq_restore(flags);
993 994 995
}
#endif

996 997 998 999 1000 1001 1002 1003
/*
 * 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
1004
{
N
Nick Piggin 已提交
1005
	unsigned long flags;
L
Linus Torvalds 已提交
1006 1007
	struct zone *zone;

1008
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
1009
		struct per_cpu_pageset *pset;
1010
		struct per_cpu_pages *pcp;
L
Linus Torvalds 已提交
1011

1012
		pset = zone_pcp(zone, cpu);
1013 1014 1015

		pcp = &pset->pcp;
		local_irq_save(flags);
1016
		free_pcppages_bulk(zone, pcp->count, pcp);
1017 1018
		pcp->count = 0;
		local_irq_restore(flags);
L
Linus Torvalds 已提交
1019 1020 1021
	}
}

1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034
/*
 * 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)
{
1035
	on_each_cpu(drain_local_pages, NULL, 1);
1036 1037
}

1038
#ifdef CONFIG_HIBERNATION
L
Linus Torvalds 已提交
1039 1040 1041

void mark_free_pages(struct zone *zone)
{
1042 1043
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
1044
	int order, t;
L
Linus Torvalds 已提交
1045 1046 1047 1048 1049 1050
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
1051 1052 1053 1054 1055 1056

	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);

1057 1058
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
1059
		}
L
Linus Torvalds 已提交
1060

1061 1062
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
1063
			unsigned long i;
L
Linus Torvalds 已提交
1064

1065 1066
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
1067
				swsusp_set_page_free(pfn_to_page(pfn + i));
1068
		}
1069
	}
L
Linus Torvalds 已提交
1070 1071
	spin_unlock_irqrestore(&zone->lock, flags);
}
1072
#endif /* CONFIG_PM */
L
Linus Torvalds 已提交
1073 1074 1075 1076

/*
 * Free a 0-order page
 */
H
Harvey Harrison 已提交
1077
static void free_hot_cold_page(struct page *page, int cold)
L
Linus Torvalds 已提交
1078 1079 1080 1081
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;
1082
	int migratetype;
1083
	int wasMlocked = __TestClearPageMlocked(page);
L
Linus Torvalds 已提交
1084

1085 1086
	kmemcheck_free_shadow(page, 0);

L
Linus Torvalds 已提交
1087 1088
	if (PageAnon(page))
		page->mapping = NULL;
N
Nick Piggin 已提交
1089
	if (free_pages_check(page))
1090 1091
		return;

1092
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
1093
		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
1094 1095
		debug_check_no_obj_freed(page_address(page), PAGE_SIZE);
	}
N
Nick Piggin 已提交
1096
	arch_free_page(page, 0);
1097 1098
	kernel_map_pages(page, 1, 0);

1099
	pcp = &zone_pcp(zone, get_cpu())->pcp;
1100 1101
	migratetype = get_pageblock_migratetype(page);
	set_page_private(page, migratetype);
L
Linus Torvalds 已提交
1102
	local_irq_save(flags);
1103
	if (unlikely(wasMlocked))
1104
		free_page_mlock(page);
1105
	__count_vm_event(PGFREE);
1106

1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121
	/*
	 * 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;
	}

1122
	if (cold)
1123
		list_add_tail(&page->lru, &pcp->lists[migratetype]);
1124
	else
1125
		list_add(&page->lru, &pcp->lists[migratetype]);
L
Linus Torvalds 已提交
1126
	pcp->count++;
N
Nick Piggin 已提交
1127
	if (pcp->count >= pcp->high) {
1128
		free_pcppages_bulk(zone, pcp->batch, pcp);
N
Nick Piggin 已提交
1129 1130
		pcp->count -= pcp->batch;
	}
1131 1132

out:
L
Linus Torvalds 已提交
1133 1134 1135 1136
	local_irq_restore(flags);
	put_cpu();
}

H
Harvey Harrison 已提交
1137
void free_hot_page(struct page *page)
L
Linus Torvalds 已提交
1138
{
1139
	trace_mm_page_free_direct(page, 0);
L
Linus Torvalds 已提交
1140 1141 1142
	free_hot_cold_page(page, 0);
}
	
N
Nick Piggin 已提交
1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154
/*
 * 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
1155 1156
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1157 1158 1159 1160 1161 1162 1163 1164 1165 1166

#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

1167 1168
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
1169 1170
}

L
Linus Torvalds 已提交
1171 1172 1173 1174 1175
/*
 * 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.
 */
1176 1177
static inline
struct page *buffered_rmqueue(struct zone *preferred_zone,
1178 1179
			struct zone *zone, int order, gfp_t gfp_flags,
			int migratetype)
L
Linus Torvalds 已提交
1180 1181
{
	unsigned long flags;
1182
	struct page *page;
L
Linus Torvalds 已提交
1183
	int cold = !!(gfp_flags & __GFP_COLD);
N
Nick Piggin 已提交
1184
	int cpu;
L
Linus Torvalds 已提交
1185

1186
again:
N
Nick Piggin 已提交
1187
	cpu  = get_cpu();
N
Nick Piggin 已提交
1188
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1189
		struct per_cpu_pages *pcp;
1190
		struct list_head *list;
L
Linus Torvalds 已提交
1191

1192
		pcp = &zone_pcp(zone, cpu)->pcp;
1193
		list = &pcp->lists[migratetype];
L
Linus Torvalds 已提交
1194
		local_irq_save(flags);
1195
		if (list_empty(list)) {
1196
			pcp->count += rmqueue_bulk(zone, 0,
1197
					pcp->batch, list,
1198
					migratetype, cold);
1199
			if (unlikely(list_empty(list)))
1200
				goto failed;
1201
		}
1202

1203 1204 1205 1206 1207
		if (cold)
			page = list_entry(list->prev, struct page, lru);
		else
			page = list_entry(list->next, struct page, lru);

1208 1209
		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1210
	} else {
1211 1212 1213 1214 1215 1216 1217 1218
		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
1219
			 * allocate greater than order-1 page units with
1220 1221
			 * __GFP_NOFAIL.
			 */
1222
			WARN_ON_ONCE(order > 1);
1223
		}
L
Linus Torvalds 已提交
1224
		spin_lock_irqsave(&zone->lock, flags);
1225
		page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1226 1227 1228
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
1229
		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
L
Linus Torvalds 已提交
1230 1231
	}

1232
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1233
	zone_statistics(preferred_zone, zone);
N
Nick Piggin 已提交
1234 1235
	local_irq_restore(flags);
	put_cpu();
L
Linus Torvalds 已提交
1236

N
Nick Piggin 已提交
1237
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1238
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1239
		goto again;
L
Linus Torvalds 已提交
1240
	return page;
N
Nick Piggin 已提交
1241 1242 1243 1244 1245

failed:
	local_irq_restore(flags);
	put_cpu();
	return NULL;
L
Linus Torvalds 已提交
1246 1247
}

1248 1249 1250 1251 1252 1253 1254 1255 1256
/* 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)

1257 1258 1259
#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
1260

1261 1262 1263 1264 1265 1266 1267
#ifdef CONFIG_FAIL_PAGE_ALLOC

static struct fail_page_alloc_attr {
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1268
	u32 min_order;
1269 1270 1271 1272 1273

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

	struct dentry *ignore_gfp_highmem_file;
	struct dentry *ignore_gfp_wait_file;
1274
	struct dentry *min_order_file;
1275 1276 1277 1278 1279

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1280 1281
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1282
	.min_order = 1,
1283 1284 1285 1286 1287 1288 1289 1290 1291 1292
};

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)
{
1293 1294
	if (order < fail_page_alloc.min_order)
		return 0;
1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325
	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);
1326 1327 1328
	fail_page_alloc.min_order_file =
		debugfs_create_u32("min-order", mode, dir,
				   &fail_page_alloc.min_order);
1329 1330

	if (!fail_page_alloc.ignore_gfp_wait_file ||
1331 1332
            !fail_page_alloc.ignore_gfp_highmem_file ||
            !fail_page_alloc.min_order_file) {
1333 1334 1335
		err = -ENOMEM;
		debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
		debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1336
		debugfs_remove(fail_page_alloc.min_order_file);
1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355
		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
1356 1357 1358 1359 1360
/*
 * 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
1361
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
1362 1363
{
	/* free_pages my go negative - that's OK */
1364 1365
	long min = mark;
	long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
L
Linus Torvalds 已提交
1366 1367
	int o;

R
Rohit Seth 已提交
1368
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1369
		min -= min / 2;
R
Rohit Seth 已提交
1370
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387
		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;
}

1388 1389 1390 1391 1392 1393
#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
1394
 * that have to skip over a lot of full or unallowed zones.
1395 1396 1397
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1398
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419
 *
 * 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
1420
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1421 1422 1423 1424 1425 1426
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1427
					&node_states[N_HIGH_MEMORY];
1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452
	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.
 */
1453
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1454 1455 1456 1457 1458 1459 1460 1461 1462 1463
						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;

1464
	i = z - zonelist->_zonerefs;
1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475
	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.
 */
1476
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1477 1478 1479 1480 1481 1482 1483 1484
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

1485
	i = z - zonelist->_zonerefs;
1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

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

1497
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1498 1499 1500 1501 1502
				nodemask_t *allowednodes)
{
	return 1;
}

1503
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1504 1505 1506 1507
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1508
/*
1509
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1510 1511 1512
 * a page.
 */
static struct page *
1513
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1514
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1515
		struct zone *preferred_zone, int migratetype)
M
Martin Hicks 已提交
1516
{
1517
	struct zoneref *z;
R
Rohit Seth 已提交
1518
	struct page *page = NULL;
1519
	int classzone_idx;
1520
	struct zone *zone;
1521 1522 1523
	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 */
1524

1525
	classzone_idx = zone_idx(preferred_zone);
1526
zonelist_scan:
R
Rohit Seth 已提交
1527
	/*
1528
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1529 1530
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1531 1532
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1533 1534 1535
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1536
		if ((alloc_flags & ALLOC_CPUSET) &&
1537
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1538
				goto try_next_zone;
R
Rohit Seth 已提交
1539

1540
		BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
R
Rohit Seth 已提交
1541
		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1542
			unsigned long mark;
1543 1544
			int ret;

1545
			mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564
			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))
1565
					goto this_zone_full;
1566
			}
R
Rohit Seth 已提交
1567 1568
		}

1569
try_this_zone:
1570 1571
		page = buffered_rmqueue(preferred_zone, zone, order,
						gfp_mask, migratetype);
1572
		if (page)
R
Rohit Seth 已提交
1573
			break;
1574 1575 1576 1577
this_zone_full:
		if (NUMA_BUILD)
			zlc_mark_zone_full(zonelist, z);
try_next_zone:
1578
		if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1579 1580 1581 1582
			/*
			 * we do zlc_setup after the first zone is tried but only
			 * if there are multiple nodes make it worthwhile
			 */
1583 1584 1585 1586
			allowednodes = zlc_setup(zonelist, alloc_flags);
			zlc_active = 1;
			did_zlc_setup = 1;
		}
1587
	}
1588 1589 1590 1591 1592 1593

	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
1594
	return page;
M
Martin Hicks 已提交
1595 1596
}

1597 1598 1599
static inline int
should_alloc_retry(gfp_t gfp_mask, unsigned int order,
				unsigned long pages_reclaimed)
L
Linus Torvalds 已提交
1600
{
1601 1602 1603
	/* Do not loop if specifically requested */
	if (gfp_mask & __GFP_NORETRY)
		return 0;
L
Linus Torvalds 已提交
1604

1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621
	/*
	 * 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;
1622

1623 1624 1625 1626 1627 1628
	/*
	 * 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
1629

1630 1631
	return 0;
}
1632

1633 1634 1635
static inline struct page *
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1636 1637
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1638 1639 1640 1641 1642 1643
{
	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
1644 1645
		return NULL;
	}
1646

1647 1648 1649 1650 1651 1652 1653
	/*
	 * 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,
1654
		ALLOC_WMARK_HIGH|ALLOC_CPUSET,
1655
		preferred_zone, migratetype);
R
Rohit Seth 已提交
1656
	if (page)
1657 1658
		goto out;

1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672
	if (!(gfp_mask & __GFP_NOFAIL)) {
		/* The OOM killer will not help higher order allocs */
		if (order > PAGE_ALLOC_COSTLY_ORDER)
			goto out;
		/*
		 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
		 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
		 * The caller should handle page allocation failure by itself if
		 * it specifies __GFP_THISNODE.
		 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
		 */
		if (gfp_mask & __GFP_THISNODE)
			goto out;
	}
1673
	/* Exhausted what can be done so it's blamo time */
1674
	out_of_memory(zonelist, gfp_mask, order, nodemask);
1675 1676 1677 1678 1679 1680 1681 1682 1683 1684

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,
1685
	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1686
	int migratetype, unsigned long *did_some_progress)
1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713
{
	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,
1714
					zonelist, high_zoneidx,
1715 1716
					alloc_flags, preferred_zone,
					migratetype);
1717 1718 1719
	return page;
}

L
Linus Torvalds 已提交
1720
/*
1721 1722
 * 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
1723
 */
1724 1725 1726
static inline struct page *
__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1727 1728
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1729 1730 1731 1732 1733
{
	struct page *page;

	do {
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1734
			zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
1735
			preferred_zone, migratetype);
1736 1737

		if (!page && gfp_mask & __GFP_NOFAIL)
1738
			congestion_wait(BLK_RW_ASYNC, HZ/50);
1739 1740 1741 1742 1743 1744 1745 1746
	} 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
1747
{
1748 1749
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
1750

1751 1752 1753
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
		wakeup_kswapd(zone, order);
}
1754

1755 1756 1757 1758 1759 1760
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
1761

1762 1763
	/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
	BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH);
1764

1765 1766 1767 1768 1769 1770
	/*
	 * 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).
	 */
1771
	alloc_flags |= (gfp_mask & __GFP_HIGH);
L
Linus Torvalds 已提交
1772

1773 1774
	if (!wait) {
		alloc_flags |= ALLOC_HARDER;
1775
		/*
1776 1777
		 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
		 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1778
		 */
1779
		alloc_flags &= ~ALLOC_CPUSET;
1780
	} else if (unlikely(rt_task(p)) && !in_interrupt())
1781 1782 1783 1784 1785 1786 1787
		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
1788
	}
1789

1790 1791 1792
	return alloc_flags;
}

1793 1794 1795
static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1796 1797
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1798 1799 1800 1801 1802 1803 1804
{
	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
1805

1806 1807 1808 1809 1810 1811
	/*
	 * 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.
	 */
1812 1813
	if (order >= MAX_ORDER) {
		WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
1814
		return NULL;
1815
	}
L
Linus Torvalds 已提交
1816

1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827
	/*
	 * 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;

1828
restart:
1829
	wake_all_kswapd(order, zonelist, high_zoneidx);
L
Linus Torvalds 已提交
1830

1831
	/*
R
Rohit Seth 已提交
1832 1833 1834
	 * 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.
1835
	 */
1836
	alloc_flags = gfp_to_alloc_flags(gfp_mask);
L
Linus Torvalds 已提交
1837

1838
	/* This is the last chance, in general, before the goto nopage. */
1839
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1840 1841
			high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
			preferred_zone, migratetype);
R
Rohit Seth 已提交
1842 1843
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1844

1845
rebalance:
1846
	/* Allocate without watermarks if the context allows */
1847 1848 1849 1850 1851 1852
	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
1853 1854 1855 1856 1857 1858
	}

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

1859 1860 1861 1862
	/* Avoid recursion of direct reclaim */
	if (p->flags & PF_MEMALLOC)
		goto nopage;

1863 1864 1865 1866
	/* Avoid allocations with no watermarks from looping endlessly */
	if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
		goto nopage;

1867 1868 1869 1870
	/* Try direct reclaim and then allocating */
	page = __alloc_pages_direct_reclaim(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
1871
					alloc_flags, preferred_zone,
1872
					migratetype, &did_some_progress);
1873 1874
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1875

1876
	/*
1877 1878
	 * If we failed to make any progress reclaiming, then we are
	 * running out of options and have to consider going OOM
1879
	 */
1880 1881
	if (!did_some_progress) {
		if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1882 1883
			if (oom_killer_disabled)
				goto nopage;
1884 1885
			page = __alloc_pages_may_oom(gfp_mask, order,
					zonelist, high_zoneidx,
1886 1887
					nodemask, preferred_zone,
					migratetype);
1888 1889
			if (page)
				goto got_pg;
L
Linus Torvalds 已提交
1890

1891
			/*
1892 1893 1894 1895
			 * 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.
1896
			 */
1897 1898
			if (order > PAGE_ALLOC_COSTLY_ORDER &&
						!(gfp_mask & __GFP_NOFAIL))
1899
				goto nopage;
1900

1901 1902
			goto restart;
		}
L
Linus Torvalds 已提交
1903 1904
	}

1905
	/* Check if we should retry the allocation */
1906
	pages_reclaimed += did_some_progress;
1907 1908
	if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
		/* Wait for some write requests to complete then retry */
1909
		congestion_wait(BLK_RW_ASYNC, HZ/50);
L
Linus Torvalds 已提交
1910 1911 1912 1913 1914 1915 1916 1917 1918
		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
1919
		show_mem();
L
Linus Torvalds 已提交
1920
	}
1921
	return page;
L
Linus Torvalds 已提交
1922
got_pg:
1923 1924
	if (kmemcheck_enabled)
		kmemcheck_pagealloc_alloc(page, order, gfp_mask);
L
Linus Torvalds 已提交
1925
	return page;
1926

L
Linus Torvalds 已提交
1927
}
1928 1929 1930 1931 1932 1933 1934 1935 1936

/*
 * 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);
1937
	struct zone *preferred_zone;
1938
	struct page *page;
1939
	int migratetype = allocflags_to_migratetype(gfp_mask);
1940

1941 1942
	gfp_mask &= gfp_allowed_mask;

1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957
	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;

1958 1959 1960 1961 1962 1963
	/* 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 */
1964
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
1965
			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
1966
			preferred_zone, migratetype);
1967 1968
	if (unlikely(!page))
		page = __alloc_pages_slowpath(gfp_mask, order,
1969
				zonelist, high_zoneidx, nodemask,
1970
				preferred_zone, migratetype);
1971

1972
	trace_mm_page_alloc(page, order, gfp_mask, migratetype);
1973
	return page;
L
Linus Torvalds 已提交
1974
}
1975
EXPORT_SYMBOL(__alloc_pages_nodemask);
L
Linus Torvalds 已提交
1976 1977 1978 1979

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
1980
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
1981
{
1982 1983 1984 1985 1986 1987 1988 1989
	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
1990 1991 1992 1993 1994 1995 1996
	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
1997
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
1998
{
1999
	return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
L
Linus Torvalds 已提交
2000 2001 2002 2003 2004 2005 2006
}
EXPORT_SYMBOL(get_zeroed_page);

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

2007 2008
	while (--i >= 0) {
		trace_mm_pagevec_free(pvec->pages[i], pvec->cold);
L
Linus Torvalds 已提交
2009
		free_hot_cold_page(pvec->pages[i], pvec->cold);
2010
	}
L
Linus Torvalds 已提交
2011 2012
}

H
Harvey Harrison 已提交
2013
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
2014
{
N
Nick Piggin 已提交
2015
	if (put_page_testzero(page)) {
2016
		trace_mm_page_free_direct(page, order);
L
Linus Torvalds 已提交
2017 2018 2019 2020 2021 2022 2023 2024 2025
		if (order == 0)
			free_hot_page(page);
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
2026
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
2027 2028
{
	if (addr != 0) {
N
Nick Piggin 已提交
2029
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
2030 2031 2032 2033 2034 2035
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058
/**
 * 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
2059
		split_page(virt_to_page((void *)addr), order);
2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088
		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
2089 2090
static unsigned int nr_free_zone_pages(int offset)
{
2091
	struct zoneref *z;
2092 2093
	struct zone *zone;

2094
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
2095 2096
	unsigned int sum = 0;

2097
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
2098

2099
	for_each_zone_zonelist(zone, z, zonelist, offset) {
2100
		unsigned long size = zone->present_pages;
2101
		unsigned long high = high_wmark_pages(zone);
2102 2103
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
2104 2105 2106 2107 2108 2109 2110 2111 2112 2113
	}

	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
2114
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
2115
}
2116
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
2117 2118 2119 2120 2121 2122

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
2123
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
2124
}
2125 2126

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
2127
{
2128
	if (NUMA_BUILD)
2129
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
2130 2131 2132 2133 2134 2135
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
2136
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150
	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;
2151
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
2152
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2153
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2154 2155
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
2156 2157 2158 2159
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172
	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)
{
2173
	int cpu;
L
Linus Torvalds 已提交
2174 2175
	struct zone *zone;

2176
	for_each_populated_zone(zone) {
2177 2178
		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
2179

2180
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
2181 2182
			struct per_cpu_pageset *pageset;

2183
			pageset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
2184

2185 2186 2187
			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
2188 2189 2190
		}
	}

K
KOSAKI Motohiro 已提交
2191 2192
	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
2193
		" unevictable:%lu"
2194
		" dirty:%lu writeback:%lu unstable:%lu\n"
2195
		" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2196
		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2197 2198
		global_page_state(NR_ACTIVE_ANON),
		global_page_state(NR_INACTIVE_ANON),
K
KOSAKI Motohiro 已提交
2199 2200
		global_page_state(NR_ISOLATED_ANON),
		global_page_state(NR_ACTIVE_FILE),
2201
		global_page_state(NR_INACTIVE_FILE),
K
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2202
		global_page_state(NR_ISOLATED_FILE),
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2203
		global_page_state(NR_UNEVICTABLE),
2204
		global_page_state(NR_FILE_DIRTY),
2205
		global_page_state(NR_WRITEBACK),
2206
		global_page_state(NR_UNSTABLE_NFS),
2207
		global_page_state(NR_FREE_PAGES),
2208 2209
		global_page_state(NR_SLAB_RECLAIMABLE),
		global_page_state(NR_SLAB_UNRECLAIMABLE),
2210
		global_page_state(NR_FILE_MAPPED),
2211
		global_page_state(NR_SHMEM),
2212 2213
		global_page_state(NR_PAGETABLE),
		global_page_state(NR_BOUNCE));
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2214

2215
	for_each_populated_zone(zone) {
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2216 2217 2218 2219 2220 2221 2222 2223
		int i;

		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
2224 2225 2226 2227
			" active_anon:%lukB"
			" inactive_anon:%lukB"
			" active_file:%lukB"
			" inactive_file:%lukB"
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2228
			" unevictable:%lukB"
K
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2229 2230
			" isolated(anon):%lukB"
			" isolated(file):%lukB"
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2231
			" present:%lukB"
2232 2233 2234 2235
			" mlocked:%lukB"
			" dirty:%lukB"
			" writeback:%lukB"
			" mapped:%lukB"
2236
			" shmem:%lukB"
2237 2238
			" slab_reclaimable:%lukB"
			" slab_unreclaimable:%lukB"
2239
			" kernel_stack:%lukB"
2240 2241 2242 2243
			" pagetables:%lukB"
			" unstable:%lukB"
			" bounce:%lukB"
			" writeback_tmp:%lukB"
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2244 2245 2246 2247
			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
2248
			K(zone_page_state(zone, NR_FREE_PAGES)),
2249 2250 2251
			K(min_wmark_pages(zone)),
			K(low_wmark_pages(zone)),
			K(high_wmark_pages(zone)),
2252 2253 2254 2255
			K(zone_page_state(zone, NR_ACTIVE_ANON)),
			K(zone_page_state(zone, NR_INACTIVE_ANON)),
			K(zone_page_state(zone, NR_ACTIVE_FILE)),
			K(zone_page_state(zone, NR_INACTIVE_FILE)),
L
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2256
			K(zone_page_state(zone, NR_UNEVICTABLE)),
K
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2257 2258
			K(zone_page_state(zone, NR_ISOLATED_ANON)),
			K(zone_page_state(zone, NR_ISOLATED_FILE)),
L
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2259
			K(zone->present_pages),
2260 2261 2262 2263
			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)),
2264
			K(zone_page_state(zone, NR_SHMEM)),
2265 2266
			K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
			K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
2267 2268
			zone_page_state(zone, NR_KERNEL_STACK) *
				THREAD_SIZE / 1024,
2269 2270 2271 2272
			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)),
L
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2273
			zone->pages_scanned,
2274
			(zone_is_all_unreclaimable(zone) ? "yes" : "no")
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2275 2276 2277 2278 2279 2280 2281
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

2282
	for_each_populated_zone(zone) {
2283
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
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2284 2285 2286 2287 2288 2289

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

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
2290 2291
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
L
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2292 2293
		}
		spin_unlock_irqrestore(&zone->lock, flags);
2294 2295
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
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2296 2297 2298
		printk("= %lukB\n", K(total));
	}

2299 2300
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

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2301 2302 2303
	show_swap_cache_info();
}

2304 2305 2306 2307 2308 2309
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
{
	zoneref->zone = zone;
	zoneref->zone_idx = zone_idx(zone);
}

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2310 2311
/*
 * Builds allocation fallback zone lists.
2312 2313
 *
 * Add all populated zones of a node to the zonelist.
L
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2314
 */
2315 2316
static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
				int nr_zones, enum zone_type zone_type)
L
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2317
{
2318 2319
	struct zone *zone;

2320
	BUG_ON(zone_type >= MAX_NR_ZONES);
2321
	zone_type++;
2322 2323

	do {
2324
		zone_type--;
2325
		zone = pgdat->node_zones + zone_type;
2326
		if (populated_zone(zone)) {
2327 2328
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
2329
			check_highest_zone(zone_type);
L
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2330
		}
2331

2332
	} while (zone_type);
2333
	return nr_zones;
L
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2334 2335
}

2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356

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

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


L
Linus Torvalds 已提交
2357
#ifdef CONFIG_NUMA
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
/* 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,
2401
		void __user *buffer, size_t *length,
2402 2403 2404 2405
		loff_t *ppos)
{
	char saved_string[NUMA_ZONELIST_ORDER_LEN];
	int ret;
2406
	static DEFINE_MUTEX(zl_order_mutex);
2407

2408
	mutex_lock(&zl_order_mutex);
2409
	if (write)
2410
		strcpy(saved_string, (char*)table->data);
2411
	ret = proc_dostring(table, write, buffer, length, ppos);
2412
	if (ret)
2413
		goto out;
2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425
	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();
	}
2426 2427 2428
out:
	mutex_unlock(&zl_order_mutex);
	return ret;
2429 2430 2431
}


2432
#define MAX_NODE_LOAD (nr_online_nodes)
2433 2434
static int node_load[MAX_NUMNODES];

L
Linus Torvalds 已提交
2435
/**
2436
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
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2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448
 * @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.
 */
2449
static int find_next_best_node(int node, nodemask_t *used_node_mask)
L
Linus Torvalds 已提交
2450
{
2451
	int n, val;
L
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2452 2453
	int min_val = INT_MAX;
	int best_node = -1;
2454
	const struct cpumask *tmp = cpumask_of_node(0);
L
Linus Torvalds 已提交
2455

2456 2457 2458 2459 2460
	/* Use the local node if we haven't already */
	if (!node_isset(node, *used_node_mask)) {
		node_set(node, *used_node_mask);
		return node;
	}
L
Linus Torvalds 已提交
2461

2462
	for_each_node_state(n, N_HIGH_MEMORY) {
L
Linus Torvalds 已提交
2463 2464 2465 2466 2467 2468 2469 2470

		/* 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);

2471 2472 2473
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
Linus Torvalds 已提交
2474
		/* Give preference to headless and unused nodes */
2475 2476
		tmp = cpumask_of_node(n);
		if (!cpumask_empty(tmp))
L
Linus Torvalds 已提交
2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494
			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;
}

2495 2496 2497 2498 2499 2500 2501

/*
 * Build zonelists ordered by node and zones within node.
 * This results in maximum locality--normal zone overflows into local
 * DMA zone, if any--but risks exhausting DMA zone.
 */
static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
L
Linus Torvalds 已提交
2502
{
2503
	int j;
L
Linus Torvalds 已提交
2504
	struct zonelist *zonelist;
2505

2506
	zonelist = &pgdat->node_zonelists[0];
2507
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2508 2509 2510
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
2511 2512
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2513 2514
}

2515 2516 2517 2518 2519 2520 2521 2522
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

2523 2524
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2525 2526
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2527 2528
}

2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543
/*
 * 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;

2544 2545 2546 2547 2548 2549 2550
	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)) {
2551 2552
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
2553
				check_highest_zone(zone_type);
2554 2555 2556
			}
		}
	}
2557 2558
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593
}

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.
         */
2594 2595
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626
	for_each_online_node(nid) {
		low_kmem_size = 0;
		total_size = 0;
		for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
			z = &NODE_DATA(nid)->node_zones[zone_type];
			if (populated_zone(z)) {
				if (zone_type < ZONE_NORMAL)
					low_kmem_size += z->present_pages;
				total_size += z->present_pages;
			}
		}
		if (low_kmem_size &&
		    total_size > average_size && /* ignore small node */
		    low_kmem_size > total_size * 70/100)
			return ZONELIST_ORDER_NODE;
	}
	return ZONELIST_ORDER_ZONE;
}

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

static void build_zonelists(pg_data_t *pgdat)
{
	int j, node, load;
	enum zone_type i;
L
Linus Torvalds 已提交
2627
	nodemask_t used_mask;
2628 2629 2630
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
L
Linus Torvalds 已提交
2631 2632

	/* initialize zonelists */
2633
	for (i = 0; i < MAX_ZONELISTS; i++) {
L
Linus Torvalds 已提交
2634
		zonelist = pgdat->node_zonelists + i;
2635 2636
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
L
Linus Torvalds 已提交
2637 2638 2639 2640
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
2641
	load = nr_online_nodes;
L
Linus Torvalds 已提交
2642 2643
	prev_node = local_node;
	nodes_clear(used_mask);
2644 2645 2646 2647

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

L
Linus Torvalds 已提交
2648
	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2649 2650 2651 2652 2653 2654 2655 2656 2657
		int distance = node_distance(local_node, node);

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

L
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2658 2659 2660 2661 2662
		/*
		 * 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.
		 */
2663
		if (distance != node_distance(local_node, prev_node))
2664 2665
			node_load[node] = load;

L
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2666 2667
		prev_node = node;
		load--;
2668 2669 2670 2671 2672
		if (order == ZONELIST_ORDER_NODE)
			build_zonelists_in_node_order(pgdat, node);
		else
			node_order[j++] = node;	/* remember order */
	}
L
Linus Torvalds 已提交
2673

2674 2675 2676
	if (order == ZONELIST_ORDER_ZONE) {
		/* calculate node order -- i.e., DMA last! */
		build_zonelists_in_zone_order(pgdat, j);
L
Linus Torvalds 已提交
2677
	}
2678 2679

	build_thisnode_zonelists(pgdat);
L
Linus Torvalds 已提交
2680 2681
}

2682
/* Construct the zonelist performance cache - see further mmzone.h */
2683
static void build_zonelist_cache(pg_data_t *pgdat)
2684
{
2685 2686
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
2687
	struct zoneref *z;
2688

2689 2690 2691
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2692 2693
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2694 2695
}

2696

L
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2697 2698
#else	/* CONFIG_NUMA */

2699 2700 2701 2702 2703 2704
static void set_zonelist_order(void)
{
	current_zonelist_order = ZONELIST_ORDER_ZONE;
}

static void build_zonelists(pg_data_t *pgdat)
L
Linus Torvalds 已提交
2705
{
2706
	int node, local_node;
2707 2708
	enum zone_type j;
	struct zonelist *zonelist;
L
Linus Torvalds 已提交
2709 2710 2711

	local_node = pgdat->node_id;

2712 2713
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
2714

2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727
	/*
	 * Now we build the zonelist so that it contains the zones
	 * of all the other nodes.
	 * We don't want to pressure a particular node, so when
	 * building the zones for node N, we make sure that the
	 * zones coming right after the local ones are those from
	 * node N+1 (modulo N)
	 */
	for (node = local_node + 1; node < MAX_NUMNODES; node++) {
		if (!node_online(node))
			continue;
		j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
2728
	}
2729 2730 2731 2732 2733 2734 2735
	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);
	}

2736 2737
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
L
Linus Torvalds 已提交
2738 2739
}

2740
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2741
static void build_zonelist_cache(pg_data_t *pgdat)
2742
{
2743
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
2744 2745
}

L
Linus Torvalds 已提交
2746 2747
#endif	/* CONFIG_NUMA */

2748
/* return values int ....just for stop_machine() */
2749
static int __build_all_zonelists(void *dummy)
L
Linus Torvalds 已提交
2750
{
2751
	int nid;
2752

2753 2754 2755
#ifdef CONFIG_NUMA
	memset(node_load, 0, sizeof(node_load));
#endif
2756
	for_each_online_node(nid) {
2757 2758 2759 2760
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
2761
	}
2762 2763 2764
	return 0;
}

2765
void build_all_zonelists(void)
2766
{
2767 2768
	set_zonelist_order();

2769
	if (system_state == SYSTEM_BOOTING) {
2770
		__build_all_zonelists(NULL);
2771
		mminit_verify_zonelist();
2772 2773
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
2774
		/* we have to stop all cpus to guarantee there is no user
2775
		   of zonelist */
2776
		stop_machine(__build_all_zonelists, NULL, NULL);
2777 2778
		/* cpuset refresh routine should be here */
	}
2779
	vm_total_pages = nr_free_pagecache_pages();
2780 2781 2782 2783 2784 2785 2786
	/*
	 * 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
	 */
2787
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2788 2789 2790 2791 2792 2793
		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",
2794
			nr_online_nodes,
2795
			zonelist_order_name[current_zonelist_order],
2796
			page_group_by_mobility_disabled ? "off" : "on",
2797 2798 2799 2800
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
L
Linus Torvalds 已提交
2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815
}

/*
 * 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

2816
#ifndef CONFIG_MEMORY_HOTPLUG
2817
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834
{
	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);
}
2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857
#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
2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870

/*
 * 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))

2871
/*
2872
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2873 2874
 * 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
2875 2876 2877 2878 2879 2880 2881
 * 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;
2882 2883
	unsigned long block_migratetype;
	int reserve;
2884 2885 2886 2887

	/* 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;
2888
	reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
2889
							pageblock_order;
2890

2891 2892 2893 2894 2895 2896 2897 2898 2899
	/*
	 * 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);

2900
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2901 2902 2903 2904
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

2905 2906 2907 2908
		/* Watch out for overlapping nodes */
		if (page_to_nid(page) != zone_to_nid(zone))
			continue;

2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938
		/* 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
2939

L
Linus Torvalds 已提交
2940 2941 2942 2943 2944
/*
 * 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.
 */
2945
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
2946
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
2947 2948
{
	struct page *page;
A
Andy Whitcroft 已提交
2949 2950
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
2951
	struct zone *z;
L
Linus Torvalds 已提交
2952

2953 2954 2955
	if (highest_memmap_pfn < end_pfn - 1)
		highest_memmap_pfn = end_pfn - 1;

2956
	z = &NODE_DATA(nid)->node_zones[zone];
2957
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968
		/*
		 * 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
2969 2970
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
2971
		mminit_verify_page_links(page, zone, nid, pfn);
2972
		init_page_count(page);
L
Linus Torvalds 已提交
2973 2974
		reset_page_mapcount(page);
		SetPageReserved(page);
2975 2976 2977 2978 2979
		/*
		 * 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
2980 2981 2982
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
2983 2984 2985 2986 2987
		 *
		 * 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.
2988
		 */
2989 2990 2991
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
2992
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2993

L
Linus Torvalds 已提交
2994 2995 2996 2997
		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))
2998
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
2999 3000 3001 3002
#endif
	}
}

3003
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
3004
{
3005 3006 3007
	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
3008 3009 3010 3011 3012 3013
		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
3014
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
3015 3016
#endif

3017
static int zone_batchsize(struct zone *zone)
3018
{
3019
#ifdef CONFIG_MMU
3020 3021 3022 3023
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
3024
	 * size of the zone.  But no more than 1/2 of a meg.
3025 3026 3027 3028
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
3029 3030
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
3031 3032 3033 3034 3035
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
3036 3037 3038
	 * 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.
3039
	 *
3040 3041 3042 3043
	 * 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.
3044
	 */
3045
	batch = rounddown_pow_of_two(batch + batch/2) - 1;
3046

3047
	return batch;
3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064

#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
3065 3066
}

A
Adrian Bunk 已提交
3067
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3068 3069
{
	struct per_cpu_pages *pcp;
3070
	int migratetype;
3071

3072 3073
	memset(p, 0, sizeof(*p));

3074
	pcp = &p->pcp;
3075 3076 3077
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
3078 3079
	for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
		INIT_LIST_HEAD(&pcp->lists[migratetype]);
3080 3081
}

3082 3083 3084 3085 3086 3087 3088 3089 3090 3091
/*
 * 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;

3092
	pcp = &p->pcp;
3093 3094 3095 3096 3097 3098 3099
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}


3100 3101
#ifdef CONFIG_NUMA
/*
3102 3103 3104 3105 3106 3107 3108
 * 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.
3109 3110 3111 3112 3113 3114 3115 3116
 *
 * 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.
3117
 */
3118
static struct per_cpu_pageset boot_pageset[NR_CPUS];
3119 3120 3121

/*
 * Dynamically allocate memory for the
3122 3123
 * per cpu pageset array in struct zone.
 */
3124
static int __cpuinit process_zones(int cpu)
3125 3126
{
	struct zone *zone, *dzone;
3127 3128 3129
	int node = cpu_to_node(cpu);

	node_set_state(node, N_CPU);	/* this node has a cpu */
3130

3131
	for_each_populated_zone(zone) {
N
Nick Piggin 已提交
3132
		zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
3133
					 GFP_KERNEL, node);
N
Nick Piggin 已提交
3134
		if (!zone_pcp(zone, cpu))
3135 3136
			goto bad;

N
Nick Piggin 已提交
3137
		setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
3138 3139 3140

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(zone_pcp(zone, cpu),
3141
			    (zone->present_pages / percpu_pagelist_fraction));
3142 3143 3144 3145 3146
	}

	return 0;
bad:
	for_each_zone(dzone) {
3147 3148
		if (!populated_zone(dzone))
			continue;
3149 3150
		if (dzone == zone)
			break;
N
Nick Piggin 已提交
3151
		kfree(zone_pcp(dzone, cpu));
3152
		zone_pcp(dzone, cpu) = &boot_pageset[cpu];
3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163
	}
	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);

3164 3165 3166
		/* Free per_cpu_pageset if it is slab allocated */
		if (pset != &boot_pageset[cpu])
			kfree(pset);
3167
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
3168 3169 3170
	}
}

3171
static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
3172 3173 3174 3175 3176 3177 3178
		unsigned long action,
		void *hcpu)
{
	int cpu = (long)hcpu;
	int ret = NOTIFY_OK;

	switch (action) {
3179
	case CPU_UP_PREPARE:
3180
	case CPU_UP_PREPARE_FROZEN:
3181 3182 3183 3184
		if (process_zones(cpu))
			ret = NOTIFY_BAD;
		break;
	case CPU_UP_CANCELED:
3185
	case CPU_UP_CANCELED_FROZEN:
3186
	case CPU_DEAD:
3187
	case CPU_DEAD_FROZEN:
3188 3189 3190 3191
		free_zone_pagesets(cpu);
		break;
	default:
		break;
3192 3193 3194 3195
	}
	return ret;
}

3196
static struct notifier_block __cpuinitdata pageset_notifier =
3197 3198
	{ &pageset_cpuup_callback, NULL, 0 };

3199
void __init setup_per_cpu_pageset(void)
3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213
{
	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
3214
static noinline __init_refok
3215
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3216 3217 3218
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
3219
	size_t alloc_size;
3220 3221 3222 3223 3224

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
3225 3226 3227 3228
	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);
3229 3230 3231
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

3232
	if (!slab_is_available()) {
3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245
		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.
		 */
3246
		zone->wait_table = vmalloc(alloc_size);
3247 3248 3249
	}
	if (!zone->wait_table)
		return -ENOMEM;
3250

3251
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3252
		init_waitqueue_head(zone->wait_table + i);
3253 3254

	return 0;
3255 3256
}

3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270
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);
3271
		free_pcppages_bulk(zone, pcp->count, pcp);
3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282
		setup_pageset(pset, batch);
		local_irq_restore(flags);
	}
	return 0;
}

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

3283
static __meminit void zone_pcp_init(struct zone *zone)
3284 3285 3286 3287 3288 3289 3290
{
	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
3291
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
3292 3293 3294 3295 3296
		setup_pageset(&boot_pageset[cpu],0);
#else
		setup_pageset(zone_pcp(zone,cpu), batch);
#endif
	}
A
Anton Blanchard 已提交
3297 3298 3299
	if (zone->present_pages)
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%lu\n",
			zone->name, zone->present_pages, batch);
3300 3301
}

3302 3303
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
3304 3305
					unsigned long size,
					enum memmap_context context)
3306 3307
{
	struct pglist_data *pgdat = zone->zone_pgdat;
3308 3309 3310 3311
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
3312 3313 3314 3315
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

3316 3317 3318 3319 3320 3321
	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));

3322
	zone_init_free_lists(zone);
3323 3324

	return 0;
3325 3326
}

3327 3328 3329 3330 3331
#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
 */
3332
static int __meminit first_active_region_index_in_nid(int nid)
3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344
{
	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
3345
 * Note: nid == MAX_NUMNODES returns next region regardless of node
3346
 */
3347
static int __meminit next_active_region_index_in_nid(int index, int nid)
3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362
{
	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
 */
3363
int __meminit __early_pfn_to_nid(unsigned long pfn)
3364 3365 3366 3367 3368 3369 3370 3371 3372 3373
{
	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;
	}
3374 3375
	/* This is a memory hole */
	return -1;
3376 3377 3378
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

3379 3380
int __meminit early_pfn_to_nid(unsigned long pfn)
{
3381 3382 3383 3384 3385 3386 3387
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0)
		return nid;
	/* just returns 0 */
	return 0;
3388 3389
}

3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400
#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
3401

3402 3403 3404 3405 3406 3407 3408
/* 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
3409 3410
 * @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
3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437
 *
 * 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);
	}
}

3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490
int __init add_from_early_node_map(struct range *range, int az,
				   int nr_range, int nid)
{
	int i;
	u64 start, end;

	/* need to go over early_node_map to find out good range for node */
	for_each_active_range_index_in_nid(i, nid) {
		start = early_node_map[i].start_pfn;
		end = early_node_map[i].end_pfn;
		nr_range = add_range(range, az, nr_range, start, end);
	}
	return nr_range;
}

void * __init __alloc_memory_core_early(int nid, u64 size, u64 align,
					u64 goal, u64 limit)
{
	int i;
	void *ptr;

	/* need to go over early_node_map to find out good range for node */
	for_each_active_range_index_in_nid(i, nid) {
		u64 addr;
		u64 ei_start, ei_last;

		ei_last = early_node_map[i].end_pfn;
		ei_last <<= PAGE_SHIFT;
		ei_start = early_node_map[i].start_pfn;
		ei_start <<= PAGE_SHIFT;
		addr = find_early_area(ei_start, ei_last,
					 goal, limit, size, align);

		if (addr == -1ULL)
			continue;

#if 0
		printk(KERN_DEBUG "alloc (nid=%d %llx - %llx) (%llx - %llx) %llx %llx => %llx\n",
				nid,
				ei_start, ei_last, goal, limit, size,
				align, addr);
#endif

		ptr = phys_to_virt(addr);
		memset(ptr, 0, size);
		reserve_early_without_check(addr, addr + size, "BOOTMEM");
		return ptr;
	}

	return NULL;
}


3491 3492 3493
void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
{
	int i;
3494
	int ret;
3495

3496 3497 3498 3499 3500 3501
	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;
	}
3502
}
3503 3504
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3505
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3506 3507 3508
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
3509
 * function may be used instead of calling memory_present() manually.
3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522
 */
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
3523 3524 3525
 * @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.
3526 3527 3528 3529
 *
 * 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
3530
 * PFNs will be 0.
3531
 */
3532
void __meminit get_pfn_range_for_nid(unsigned int nid,
3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543
			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);
	}

3544
	if (*start_pfn == -1UL)
3545 3546 3547
		*start_pfn = 0;
}

M
Mel Gorman 已提交
3548 3549 3550 3551 3552
/*
 * 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
3553
static void __init find_usable_zone_for_movable(void)
M
Mel Gorman 已提交
3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578
{
	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
3579
static void __meminit adjust_zone_range_for_zone_movable(int nid,
M
Mel Gorman 已提交
3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604
					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;
	}
}

3605 3606 3607 3608
/*
 * 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
3609
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3610 3611 3612 3613 3614 3615 3616 3617 3618 3619
					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
3620 3621 3622
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637

	/* 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,
3638
 * then all holes in the requested range will be accounted for.
3639
 */
3640
unsigned long __meminit __absent_pages_in_range(int nid,
3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652
				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;

3653 3654
	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);

3655 3656
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
3657
		hole_pages = prev_end_pfn - range_start_pfn;
3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677

	/* 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;
	}

3678 3679
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
3680
		hole_pages += range_end_pfn -
3681 3682
				max(range_start_pfn, prev_end_pfn);

3683 3684 3685 3686 3687 3688 3689 3690
	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
 *
3691
 * It returns the number of pages frames in memory holes within a range.
3692 3693 3694 3695 3696 3697 3698 3699
 */
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
3700
static unsigned long __meminit zone_absent_pages_in_node(int nid,
3701 3702 3703
					unsigned long zone_type,
					unsigned long *ignored)
{
3704 3705 3706 3707 3708 3709 3710 3711 3712
	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
3713 3714 3715
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
3716
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3717
}
3718

3719
#else
P
Paul Mundt 已提交
3720
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3721 3722 3723 3724 3725 3726
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
3727
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3728 3729 3730 3731 3732 3733 3734 3735
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
3736

3737 3738
#endif

3739
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759
		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);
}

3760 3761 3762
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
3763 3764
 * 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
3765 3766 3767 3768 3769 3770 3771
 * 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;

3772 3773
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784
	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;
3785
	if (usemapsize)
3786 3787 3788 3789 3790 3791 3792
		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 */

3793
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3794 3795 3796 3797 3798 3799 3800 3801 3802 3803

/* 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;
}

3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818
/* 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 */

3819 3820 3821 3822 3823 3824 3825 3826 3827 3828
/*
 * 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;
}
3829 3830 3831 3832
#define set_pageblock_order(x)	do {} while (0)

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
3833 3834 3835 3836 3837 3838
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
3839
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3840 3841
		unsigned long *zones_size, unsigned long *zholes_size)
{
3842
	enum zone_type j;
3843
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
3844
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
3845
	int ret;
L
Linus Torvalds 已提交
3846

3847
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
3848 3849 3850
	pgdat->nr_zones = 0;
	init_waitqueue_head(&pgdat->kswapd_wait);
	pgdat->kswapd_max_order = 0;
3851
	pgdat_page_cgroup_init(pgdat);
L
Linus Torvalds 已提交
3852 3853 3854
	
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
3855
		unsigned long size, realsize, memmap_pages;
3856
		enum lru_list l;
L
Linus Torvalds 已提交
3857

3858 3859 3860
		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
3861

3862 3863 3864 3865 3866
		/*
		 * 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
		 */
3867 3868
		memmap_pages =
			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
3869 3870
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
3871 3872 3873 3874
			if (memmap_pages)
				printk(KERN_DEBUG
				       "  %s zone: %lu pages used for memmap\n",
				       zone_names[j], memmap_pages);
3875 3876 3877 3878 3879
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

3880 3881
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
3882
			realsize -= dma_reserve;
Y
Yinghai Lu 已提交
3883
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
3884
					zone_names[0], dma_reserve);
3885 3886
		}

3887
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
3888 3889 3890 3891 3892
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
3893
#ifdef CONFIG_NUMA
3894
		zone->node = nid;
3895
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3896
						/ 100;
3897
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3898
#endif
L
Linus Torvalds 已提交
3899 3900 3901
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
3902
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
3903 3904
		zone->zone_pgdat = pgdat;

3905
		zone->prev_priority = DEF_PRIORITY;
L
Linus Torvalds 已提交
3906

3907
		zone_pcp_init(zone);
3908 3909
		for_each_lru(l) {
			INIT_LIST_HEAD(&zone->lru[l].list);
3910
			zone->reclaim_stat.nr_saved_scan[l] = 0;
3911
		}
3912 3913 3914 3915
		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;
3916
		zap_zone_vm_stats(zone);
3917
		zone->flags = 0;
L
Linus Torvalds 已提交
3918 3919 3920
		if (!size)
			continue;

3921
		set_pageblock_order(pageblock_default_order());
3922
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
3923 3924
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
3925
		BUG_ON(ret);
3926
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
3927 3928 3929 3930
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
3931
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
3932 3933 3934 3935 3936
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
3937
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
3938 3939
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
3940
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
3941 3942
		struct page *map;

3943 3944 3945 3946 3947 3948 3949 3950 3951
		/*
		 * 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);
3952 3953 3954
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
3955
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
3956
	}
3957
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
3958 3959 3960
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
3961
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
3962
		mem_map = NODE_DATA(0)->node_mem_map;
3963 3964
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3965
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3966 3967
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
3968
#endif
A
Andy Whitcroft 已提交
3969
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
3970 3971
}

3972 3973
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
3974
{
3975 3976
	pg_data_t *pgdat = NODE_DATA(nid);

L
Linus Torvalds 已提交
3977 3978
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
3979
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
3980 3981

	alloc_node_mem_map(pgdat);
3982 3983 3984 3985 3986
#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
3987 3988 3989 3990

	free_area_init_core(pgdat, zones_size, zholes_size);
}

3991
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
M
Miklos Szeredi 已提交
3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011

#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

4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028
/**
 * 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;

4029 4030 4031 4032 4033
	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);
4034

4035 4036
	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);

4037 4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054
	/* 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 */
4055
		if (start_pfn < early_node_map[i].start_pfn &&
4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075
				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;
}

/**
4076
 * remove_active_range - Shrink an existing registered range of PFNs
4077
 * @nid: The node id the range is on that should be shrunk
4078 4079
 * @start_pfn: The new PFN of the range
 * @end_pfn: The new PFN of the range
4080 4081
 *
 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
4082 4083 4084
 * 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.
4085
 */
4086 4087
void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
				unsigned long end_pfn)
4088
{
4089 4090
	int i, j;
	int removed = 0;
4091

4092 4093 4094
	printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
			  nid, start_pfn, end_pfn);

4095
	/* Find the old active region end and shrink */
4096
	for_each_active_range_index_in_nid(i, nid) {
4097 4098
		if (early_node_map[i].start_pfn >= start_pfn &&
		    early_node_map[i].end_pfn <= end_pfn) {
4099
			/* clear it */
4100
			early_node_map[i].start_pfn = 0;
4101 4102 4103 4104
			early_node_map[i].end_pfn = 0;
			removed = 1;
			continue;
		}
4105 4106 4107 4108 4109 4110 4111 4112 4113 4114 4115 4116
		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;
4117
			continue;
4118
		}
4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137
	}

	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--;
	}
4138 4139 4140 4141
}

/**
 * remove_all_active_ranges - Remove all currently registered regions
4142
 *
4143 4144 4145 4146
 * 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.
 */
4147
void __init remove_all_active_ranges(void)
4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168
{
	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 */
4169
void __init sort_node_map(void)
4170 4171 4172 4173 4174 4175
{
	sort(early_node_map, (size_t)nr_nodemap_entries,
			sizeof(struct node_active_region),
			cmp_node_active_region, NULL);
}

4176
/* Find the lowest pfn for a node */
A
Adrian Bunk 已提交
4177
static unsigned long __init find_min_pfn_for_node(int nid)
4178 4179
{
	int i;
4180
	unsigned long min_pfn = ULONG_MAX;
4181

4182 4183
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
4184
		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
4185

4186 4187
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
4188
			"Could not find start_pfn for node %d\n", nid);
4189 4190 4191 4192
		return 0;
	}

	return min_pfn;
4193 4194 4195 4196 4197 4198
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
4199
 * add_active_range().
4200 4201 4202 4203 4204 4205
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

4206 4207 4208 4209 4210
/*
 * 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
4211
static unsigned long __init early_calculate_totalpages(void)
4212 4213 4214 4215
{
	int i;
	unsigned long totalpages = 0;

4216 4217
	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long pages = early_node_map[i].end_pfn -
4218
						early_node_map[i].start_pfn;
4219 4220 4221 4222 4223
		totalpages += pages;
		if (pages)
			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
	}
  	return totalpages;
4224 4225
}

M
Mel Gorman 已提交
4226 4227 4228 4229 4230 4231
/*
 * 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
4232
static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
M
Mel Gorman 已提交
4233 4234 4235 4236
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
4237 4238
	/* save the state before borrow the nodemask */
	nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4239 4240
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
4241

4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263
	/*
	 * 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
4264 4265
	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
	if (!required_kernelcore)
4266
		goto out;
M
Mel Gorman 已提交
4267 4268 4269 4270 4271 4272 4273 4274

	/* 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;
4275
	for_each_node_state(nid, N_HIGH_MEMORY) {
M
Mel Gorman 已提交
4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302 4303 4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 4330 4331 4332 4333 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363 4364
		/*
		 * 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);
4365 4366 4367 4368

out:
	/* restore the node_state */
	node_states[N_HIGH_MEMORY] = saved_node_state;
M
Mel Gorman 已提交
4369 4370
}

4371 4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384
/* 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
}

4385 4386
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
4387
 * @max_zone_pfn: an array of max PFNs for each zone
4388 4389 4390 4391 4392 4393 4394 4395 4396 4397 4398 4399 4400
 *
 * 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;
4401
	int i;
4402

4403 4404 4405
	/* Sort early_node_map as initialisation assumes it is sorted */
	sort_node_map();

4406 4407 4408 4409 4410 4411 4412 4413
	/* 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
4414 4415
		if (i == ZONE_MOVABLE)
			continue;
4416 4417 4418 4419 4420
		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
4421 4422 4423 4424 4425 4426
	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);
4427 4428 4429

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
M
Mel Gorman 已提交
4430 4431 4432
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
4433
		printk("  %-8s %0#10lx -> %0#10lx\n",
4434 4435 4436
				zone_names[i],
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);
M
Mel Gorman 已提交
4437 4438 4439 4440 4441 4442 4443 4444
	}

	/* 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]);
	}
4445 4446 4447 4448

	/* 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++)
4449
		printk("  %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4450 4451 4452 4453
						early_node_map[i].start_pfn,
						early_node_map[i].end_pfn);

	/* Initialise every node */
4454
	mminit_verify_pageflags_layout();
4455
	setup_nr_node_ids();
4456 4457
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
4458
		free_area_init_node(nid, NULL,
4459
				find_min_pfn_for_node(nid), NULL);
4460 4461 4462 4463 4464

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
4465 4466
	}
}
M
Mel Gorman 已提交
4467

4468
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
4469 4470 4471 4472 4473 4474
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
4475
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
4476

4477
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
4478 4479 4480 4481
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
4482

4483 4484 4485 4486 4487 4488 4489 4490 4491 4492 4493 4494 4495 4496 4497 4498 4499 4500
/*
 * 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
4501
early_param("kernelcore", cmdline_parse_kernelcore);
4502
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
4503

4504 4505
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

4506
/**
4507 4508
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
4509 4510 4511 4512
 *
 * 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
4513 4514 4515
 * 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.
4516 4517 4518 4519 4520 4521
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

4522
#ifndef CONFIG_NEED_MULTIPLE_NODES
4523 4524 4525 4526 4527
struct pglist_data __refdata contig_page_data = {
#ifndef CONFIG_NO_BOOTMEM
 .bdata = &bootmem_node_data[0]
#endif
 };
L
Linus Torvalds 已提交
4528
EXPORT_SYMBOL(contig_page_data);
4529
#endif
L
Linus Torvalds 已提交
4530 4531 4532

void __init free_area_init(unsigned long *zones_size)
{
4533
	free_area_init_node(0, zones_size,
L
Linus Torvalds 已提交
4534 4535 4536 4537 4538 4539 4540 4541
			__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;

4542
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4543 4544 4545 4546 4547 4548 4549 4550
		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.
		 */
4551
		vm_events_fold_cpu(cpu);
4552 4553 4554 4555 4556 4557 4558 4559

		/*
		 * 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.
		 */
4560
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
4561 4562 4563 4564 4565 4566 4567 4568 4569
	}
	return NOTIFY_OK;
}

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

4570 4571 4572 4573 4574 4575 4576 4577
/*
 * 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;
4578
	enum zone_type i, j;
4579 4580 4581 4582 4583 4584 4585 4586 4587 4588 4589 4590

	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];
			}

4591 4592
			/* we treat the high watermark as reserved pages. */
			max += high_wmark_pages(zone);
4593 4594 4595 4596 4597 4598 4599 4600 4601

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

L
Linus Torvalds 已提交
4602 4603 4604 4605 4606 4607 4608 4609 4610
/*
 * 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;
4611
	enum zone_type j, idx;
L
Linus Torvalds 已提交
4612

4613
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
4614 4615 4616 4617 4618 4619
		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;

4620 4621
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
4622 4623
				struct zone *lower_zone;

4624 4625
				idx--;

L
Linus Torvalds 已提交
4626 4627 4628 4629 4630 4631 4632 4633 4634 4635
				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;
			}
		}
	}
4636 4637 4638

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4639 4640
}

4641
/**
4642
 * setup_per_zone_wmarks - called when min_free_kbytes changes
4643
 * or when memory is hot-{added|removed}
4644
 *
4645 4646
 * 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
4647
 */
4648
void setup_per_zone_wmarks(void)
L
Linus Torvalds 已提交
4649 4650 4651 4652 4653 4654 4655 4656 4657 4658 4659 4660 4661
{
	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) {
4662 4663
		u64 tmp;

4664
		spin_lock_irqsave(&zone->lock, flags);
4665 4666
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
4667 4668
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
4669 4670 4671 4672
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
4673
			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
N
Nick Piggin 已提交
4674 4675
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
Linus Torvalds 已提交
4676 4677 4678 4679 4680 4681 4682 4683
			 */
			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;
4684
			zone->watermark[WMARK_MIN] = min_pages;
L
Linus Torvalds 已提交
4685
		} else {
N
Nick Piggin 已提交
4686 4687
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
4688 4689
			 * proportionate to the zone's size.
			 */
4690
			zone->watermark[WMARK_MIN] = tmp;
L
Linus Torvalds 已提交
4691 4692
		}

4693 4694
		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) + (tmp >> 2);
		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
4695
		setup_zone_migrate_reserve(zone);
4696
		spin_unlock_irqrestore(&zone->lock, flags);
L
Linus Torvalds 已提交
4697
	}
4698 4699 4700

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4701 4702
}

4703
/*
4704 4705 4706 4707 4708 4709 4710 4711 4712 4713 4714 4715 4716 4717 4718 4719 4720 4721 4722 4723
 * 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
 */
4724
void calculate_zone_inactive_ratio(struct zone *zone)
4725
{
4726
	unsigned int gb, ratio;
4727

4728 4729 4730
	/* Zone size in gigabytes */
	gb = zone->present_pages >> (30 - PAGE_SHIFT);
	if (gb)
4731
		ratio = int_sqrt(10 * gb);
4732 4733
	else
		ratio = 1;
4734

4735 4736
	zone->inactive_ratio = ratio;
}
4737

4738 4739 4740 4741 4742 4743
static void __init setup_per_zone_inactive_ratio(void)
{
	struct zone *zone;

	for_each_zone(zone)
		calculate_zone_inactive_ratio(zone);
4744 4745
}

L
Linus Torvalds 已提交
4746 4747 4748 4749 4750 4751 4752 4753 4754 4755 4756 4757 4758 4759 4760 4761 4762 4763 4764 4765 4766 4767 4768 4769
/*
 * 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
 */
4770
static int __init init_per_zone_wmark_min(void)
L
Linus Torvalds 已提交
4771 4772 4773 4774 4775 4776 4777 4778 4779 4780
{
	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;
4781
	setup_per_zone_wmarks();
L
Linus Torvalds 已提交
4782
	setup_per_zone_lowmem_reserve();
4783
	setup_per_zone_inactive_ratio();
L
Linus Torvalds 已提交
4784 4785
	return 0;
}
4786
module_init(init_per_zone_wmark_min)
L
Linus Torvalds 已提交
4787 4788 4789 4790 4791 4792 4793

/*
 * 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, 
4794
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
4795
{
4796
	proc_dointvec(table, write, buffer, length, ppos);
4797
	if (write)
4798
		setup_per_zone_wmarks();
L
Linus Torvalds 已提交
4799 4800 4801
	return 0;
}

4802 4803
#ifdef CONFIG_NUMA
int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
4804
	void __user *buffer, size_t *length, loff_t *ppos)
4805 4806 4807 4808
{
	struct zone *zone;
	int rc;

4809
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
4810 4811 4812 4813
	if (rc)
		return rc;

	for_each_zone(zone)
4814
		zone->min_unmapped_pages = (zone->present_pages *
4815 4816 4817
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
4818 4819

int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
4820
	void __user *buffer, size_t *length, loff_t *ppos)
4821 4822 4823 4824
{
	struct zone *zone;
	int rc;

4825
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
4826 4827 4828 4829 4830 4831 4832 4833
	if (rc)
		return rc;

	for_each_zone(zone)
		zone->min_slab_pages = (zone->present_pages *
				sysctl_min_slab_ratio) / 100;
	return 0;
}
4834 4835
#endif

L
Linus Torvalds 已提交
4836 4837 4838 4839 4840 4841
/*
 * 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
4842
 * minimum watermarks. The lowmem reserve ratio can only make sense
L
Linus Torvalds 已提交
4843 4844 4845
 * if in function of the boot time zone sizes.
 */
int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
4846
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
4847
{
4848
	proc_dointvec_minmax(table, write, buffer, length, ppos);
L
Linus Torvalds 已提交
4849 4850 4851 4852
	setup_per_zone_lowmem_reserve();
	return 0;
}

4853 4854 4855 4856 4857 4858 4859
/*
 * 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,
4860
	void __user *buffer, size_t *length, loff_t *ppos)
4861 4862 4863 4864 4865
{
	struct zone *zone;
	unsigned int cpu;
	int ret;

4866
	ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
4867 4868
	if (!write || (ret == -EINVAL))
		return ret;
4869
	for_each_populated_zone(zone) {
4870 4871 4872 4873 4874 4875 4876 4877 4878
		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;
}

4879
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893 4894 4895 4896 4897 4898 4899 4900 4901 4902 4903 4904 4905 4906 4907 4908 4909 4910 4911 4912 4913

#ifdef CONFIG_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
4914
		numentries = nr_kernel_pages;
L
Linus Torvalds 已提交
4915 4916 4917 4918 4919 4920 4921 4922 4923
		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);
4924 4925

		/* Make sure we've got at least a 0-order allocation.. */
4926 4927 4928 4929 4930 4931 4932 4933
		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))
4934
			numentries = PAGE_SIZE / bucketsize;
L
Linus Torvalds 已提交
4935
	}
4936
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
4937 4938 4939 4940 4941 4942 4943 4944 4945 4946

	/* 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;

4947
	log2qty = ilog2(numentries);
L
Linus Torvalds 已提交
4948 4949 4950 4951

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
4952
			table = alloc_bootmem_nopanic(size);
L
Linus Torvalds 已提交
4953 4954 4955
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
4956 4957
			/*
			 * If bucketsize is not a power-of-two, we may free
4958 4959
			 * some pages at the end of hash table which
			 * alloc_pages_exact() automatically does
4960
			 */
4961
			if (get_order(size) < MAX_ORDER) {
4962
				table = alloc_pages_exact(size, GFP_ATOMIC);
4963 4964
				kmemleak_alloc(table, size, 1, GFP_ATOMIC);
			}
L
Linus Torvalds 已提交
4965 4966 4967 4968 4969 4970
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

4971
	printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
L
Linus Torvalds 已提交
4972 4973
	       tablename,
	       (1U << log2qty),
4974
	       ilog2(size) - PAGE_SHIFT,
L
Linus Torvalds 已提交
4975 4976 4977 4978 4979 4980 4981 4982 4983
	       size);

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

	return table;
}
4984

4985 4986 4987 4988 4989 4990 4991 4992 4993 4994 4995 4996 4997 4998 4999
/* 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);
5000
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5001 5002
#else
	pfn = pfn - zone->zone_start_pfn;
5003
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5004 5005 5006 5007
#endif /* CONFIG_SPARSEMEM */
}

/**
5008
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5009 5010 5011 5012 5013 5014 5015 5016 5017 5018 5019 5020 5021 5022 5023 5024 5025 5026 5027 5028 5029 5030
 * @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;
5031

5032 5033 5034 5035
	return flags;
}

/**
5036
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5037 5038 5039 5040 5041 5042 5043 5044 5045 5046 5047 5048 5049 5050 5051 5052 5053
 * @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);
5054 5055
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
5056 5057 5058 5059 5060 5061 5062

	for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
		if (flags & value)
			__set_bit(bitidx + start_bitidx, bitmap);
		else
			__clear_bit(bitidx + start_bitidx, bitmap);
}
K
KAMEZAWA Hiroyuki 已提交
5063 5064 5065 5066 5067 5068 5069 5070 5071 5072

/*
 * 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;
5073 5074 5075 5076 5077
	struct page *curr_page;
	unsigned long flags, pfn, iter;
	unsigned long immobile = 0;
	struct memory_isolate_notify arg;
	int notifier_ret;
K
KAMEZAWA Hiroyuki 已提交
5078
	int ret = -EBUSY;
5079
	int zone_idx;
K
KAMEZAWA Hiroyuki 已提交
5080 5081

	zone = page_zone(page);
5082
	zone_idx = zone_idx(zone);
5083

K
KAMEZAWA Hiroyuki 已提交
5084
	spin_lock_irqsave(&zone->lock, flags);
5085 5086 5087 5088 5089 5090 5091 5092 5093 5094 5095
	if (get_pageblock_migratetype(page) == MIGRATE_MOVABLE ||
	    zone_idx == ZONE_MOVABLE) {
		ret = 0;
		goto out;
	}

	pfn = page_to_pfn(page);
	arg.start_pfn = pfn;
	arg.nr_pages = pageblock_nr_pages;
	arg.pages_found = 0;

K
KAMEZAWA Hiroyuki 已提交
5096
	/*
5097 5098 5099 5100 5101 5102 5103 5104 5105
	 * It may be possible to isolate a pageblock even if the
	 * migratetype is not MIGRATE_MOVABLE. The memory isolation
	 * notifier chain is used by balloon drivers to return the
	 * number of pages in a range that are held by the balloon
	 * driver to shrink memory. If all the pages are accounted for
	 * by balloons, are free, or on the LRU, isolation can continue.
	 * Later, for example, when memory hotplug notifier runs, these
	 * pages reported as "can be isolated" should be isolated(freed)
	 * by the balloon driver through the memory notifier chain.
K
KAMEZAWA Hiroyuki 已提交
5106
	 */
5107 5108 5109
	notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);
	notifier_ret = notifier_to_errno(notifier_ret);
	if (notifier_ret || !arg.pages_found)
K
KAMEZAWA Hiroyuki 已提交
5110
		goto out;
5111 5112 5113 5114 5115 5116 5117 5118 5119 5120 5121 5122 5123 5124 5125

	for (iter = pfn; iter < (pfn + pageblock_nr_pages); iter++) {
		if (!pfn_valid_within(pfn))
			continue;

		curr_page = pfn_to_page(iter);
		if (!page_count(curr_page) || PageLRU(curr_page))
			continue;

		immobile++;
	}

	if (arg.pages_found == immobile)
		ret = 0;

K
KAMEZAWA Hiroyuki 已提交
5126
out:
5127 5128 5129 5130 5131
	if (!ret) {
		set_pageblock_migratetype(page, MIGRATE_ISOLATE);
		move_freepages_block(zone, page, MIGRATE_ISOLATE);
	}

K
KAMEZAWA Hiroyuki 已提交
5132 5133
	spin_unlock_irqrestore(&zone->lock, flags);
	if (!ret)
5134
		drain_all_pages();
K
KAMEZAWA Hiroyuki 已提交
5135 5136 5137 5138 5139 5140 5141 5142 5143 5144 5145 5146 5147 5148 5149 5150
	return ret;
}

void unset_migratetype_isolate(struct page *page)
{
	struct zone *zone;
	unsigned long flags;
	zone = page_zone(page);
	spin_lock_irqsave(&zone->lock, flags);
	if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
		goto out;
	set_pageblock_migratetype(page, MIGRATE_MOVABLE);
	move_freepages_block(zone, page, MIGRATE_MOVABLE);
out:
	spin_unlock_irqrestore(&zone->lock, flags);
}
K
KAMEZAWA Hiroyuki 已提交
5151 5152 5153 5154 5155 5156 5157 5158 5159 5160 5161 5162 5163 5164 5165 5166 5167 5168 5169 5170 5171 5172 5173 5174 5175 5176 5177 5178 5179 5180 5181 5182 5183 5184 5185 5186 5187 5188 5189 5190 5191 5192 5193 5194 5195 5196 5197

#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
5198 5199 5200 5201 5202 5203 5204 5205 5206 5207 5208 5209 5210 5211 5212 5213 5214 5215 5216 5217 5218

#ifdef CONFIG_MEMORY_FAILURE
bool is_free_buddy_page(struct page *page)
{
	struct zone *zone = page_zone(page);
	unsigned long pfn = page_to_pfn(page);
	unsigned long flags;
	int order;

	spin_lock_irqsave(&zone->lock, flags);
	for (order = 0; order < MAX_ORDER; order++) {
		struct page *page_head = page - (pfn & ((1 << order) - 1));

		if (PageBuddy(page_head) && page_order(page_head) >= order)
			break;
	}
	spin_unlock_irqrestore(&zone->lock, flags);

	return order < MAX_ORDER;
}
#endif