page_alloc.c 150.3 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 <linux/compaction.h>
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#include <trace/events/kmem.h>
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#include <linux/ftrace_event.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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#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
DEFINE_PER_CPU(int, numa_node);
EXPORT_PER_CPU_SYMBOL(numa_node);
#endif

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#ifdef CONFIG_HAVE_MEMORYLESS_NODES
/*
 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
 * defined in <linux/topology.h>.
 */
DEFINE_PER_CPU(int, _numa_mem_);		/* Kernel "local memory" node */
EXPORT_PER_CPU_SYMBOL(_numa_mem_);
#endif

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/*
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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_PM_SLEEP
/*
 * The following functions are used by the suspend/hibernate code to temporarily
 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
 * while devices are suspended.  To avoid races with the suspend/hibernate code,
 * they should always be called with pm_mutex held (gfp_allowed_mask also should
 * only be modified with pm_mutex held, unless the suspend/hibernate code is
 * guaranteed not to run in parallel with that modification).
 */
void set_gfp_allowed_mask(gfp_t mask)
{
	WARN_ON(!mutex_is_locked(&pm_mutex));
	gfp_allowed_mask = mask;
}

gfp_t clear_gfp_allowed_mask(gfp_t mask)
{
	gfp_t ret = gfp_allowed_mask;

	WARN_ON(!mutex_is_locked(&pm_mutex));
	gfp_allowed_mask &= ~mask;
	return ret;
}
#endif /* CONFIG_PM_SLEEP */

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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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	dump_page(page);
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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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	unsigned long combined_idx;
	struct page *buddy;
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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) {
		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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	/*
	 * If this is not the largest possible page, check if the buddy
	 * of the next-highest order is free. If it is, it's possible
	 * that pages are being freed that will coalesce soon. In case,
	 * that is happening, add the free page to the tail of the list
	 * so it's less likely to be used soon and more likely to be merged
	 * as a higher order page
	 */
	if ((order < MAX_ORDER-1) && pfn_valid_within(page_to_pfn(buddy))) {
		struct page *higher_page, *higher_buddy;
		combined_idx = __find_combined_index(page_idx, order);
		higher_page = page + combined_idx - page_idx;
		higher_buddy = __page_find_buddy(higher_page, combined_idx, order + 1);
		if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
			list_add_tail(&page->lru,
				&zone->free_area[order].free_list[migratetype]);
			goto out;
		}
	}

	list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
out:
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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)
L
Linus Torvalds 已提交
562
{
N
Nick Piggin 已提交
563 564
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
565
		(atomic_read(&page->_count) != 0) |
566
		(page->flags & PAGE_FLAGS_CHECK_AT_FREE))) {
N
Nick Piggin 已提交
567
		bad_page(page);
568
		return 1;
569
	}
570 571 572
	if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
		page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
	return 0;
L
Linus Torvalds 已提交
573 574 575
}

/*
576
 * Frees a number of pages from the PCP lists
L
Linus Torvalds 已提交
577
 * Assumes all pages on list are in same zone, and of same order.
578
 * count is the number of pages to free.
L
Linus Torvalds 已提交
579 580 581 582 583 584 585
 *
 * 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.
 */
586 587
static void free_pcppages_bulk(struct zone *zone, int count,
					struct per_cpu_pages *pcp)
L
Linus Torvalds 已提交
588
{
589
	int migratetype = 0;
590
	int batch_free = 0;
591

N
Nick Piggin 已提交
592
	spin_lock(&zone->lock);
593
	zone->all_unreclaimable = 0;
L
Linus Torvalds 已提交
594
	zone->pages_scanned = 0;
595

596
	__mod_zone_page_state(zone, NR_FREE_PAGES, count);
597
	while (count) {
N
Nick Piggin 已提交
598
		struct page *page;
599 600 601
		struct list_head *list;

		/*
602 603 604 605 606
		 * 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
607 608
		 */
		do {
609
			batch_free++;
610 611 612 613
			if (++migratetype == MIGRATE_PCPTYPES)
				migratetype = 0;
			list = &pcp->lists[migratetype];
		} while (list_empty(list));
N
Nick Piggin 已提交
614

615 616 617 618
		do {
			page = list_entry(list->prev, struct page, lru);
			/* must delete as __free_one_page list manipulates */
			list_del(&page->lru);
619 620 621
			/* 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));
622
		} while (--count && --batch_free && !list_empty(list));
L
Linus Torvalds 已提交
623
	}
N
Nick Piggin 已提交
624
	spin_unlock(&zone->lock);
L
Linus Torvalds 已提交
625 626
}

627 628
static void free_one_page(struct zone *zone, struct page *page, int order,
				int migratetype)
L
Linus Torvalds 已提交
629
{
630
	spin_lock(&zone->lock);
631
	zone->all_unreclaimable = 0;
632
	zone->pages_scanned = 0;
633 634

	__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
635
	__free_one_page(page, zone, order, migratetype);
636
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
637 638
}

639
static bool free_pages_prepare(struct page *page, unsigned int order)
N
Nick Piggin 已提交
640
{
L
Linus Torvalds 已提交
641
	int i;
642
	int bad = 0;
L
Linus Torvalds 已提交
643

644
	trace_mm_page_free_direct(page, order);
645 646
	kmemcheck_free_shadow(page, order);

647 648 649 650 651 652 653
	for (i = 0; i < (1 << order); i++) {
		struct page *pg = page + i;

		if (PageAnon(pg))
			pg->mapping = NULL;
		bad += free_pages_check(pg);
	}
654
	if (bad)
655
		return false;
656

657
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
658
		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
659 660 661
		debug_check_no_obj_freed(page_address(page),
					   PAGE_SIZE << order);
	}
N
Nick Piggin 已提交
662
	arch_free_page(page, order);
N
Nick Piggin 已提交
663
	kernel_map_pages(page, 1 << order, 0);
N
Nick Piggin 已提交
664

665 666 667 668 669 670 671 672 673 674 675
	return true;
}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
	int wasMlocked = __TestClearPageMlocked(page);

	if (!free_pages_prepare(page, order))
		return;

N
Nick Piggin 已提交
676
	local_irq_save(flags);
677
	if (unlikely(wasMlocked))
678
		free_page_mlock(page);
679
	__count_vm_events(PGFREE, 1 << order);
680 681
	free_one_page(page_zone(page), page, order,
					get_pageblock_migratetype(page));
N
Nick Piggin 已提交
682
	local_irq_restore(flags);
L
Linus Torvalds 已提交
683 684
}

685 686 687
/*
 * permit the bootmem allocator to evade page validation on high-order frees
 */
688
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
689 690 691 692
{
	if (order == 0) {
		__ClearPageReserved(page);
		set_page_count(page, 0);
693
		set_page_refcounted(page);
N
Nick Piggin 已提交
694
		__free_page(page);
695 696 697
	} else {
		int loop;

N
Nick Piggin 已提交
698
		prefetchw(page);
699 700 701
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

N
Nick Piggin 已提交
702 703
			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
704 705 706 707
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

708
		set_page_refcounted(page);
N
Nick Piggin 已提交
709
		__free_pages(page, order);
710 711 712
	}
}

L
Linus Torvalds 已提交
713 714 715 716 717 718 719 720 721 722 723 724 725 726 727

/*
 * 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
728
static inline void expand(struct zone *zone, struct page *page,
729 730
	int low, int high, struct free_area *area,
	int migratetype)
L
Linus Torvalds 已提交
731 732 733 734 735 736 737
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
738
		VM_BUG_ON(bad_range(zone, &page[size]));
739
		list_add(&page[size].lru, &area->free_list[migratetype]);
L
Linus Torvalds 已提交
740 741 742 743 744 745 746 747
		area->nr_free++;
		set_page_order(&page[size], high);
	}
}

/*
 * This page is about to be returned from the page allocator
 */
748
static inline int check_new_page(struct page *page)
L
Linus Torvalds 已提交
749
{
N
Nick Piggin 已提交
750 751
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
752
		(atomic_read(&page->_count) != 0)  |
753
		(page->flags & PAGE_FLAGS_CHECK_AT_PREP))) {
N
Nick Piggin 已提交
754
		bad_page(page);
755
		return 1;
756
	}
757 758 759 760 761 762 763 764 765 766 767 768
	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;
	}
769

H
Hugh Dickins 已提交
770
	set_page_private(page, 0);
771
	set_page_refcounted(page);
N
Nick Piggin 已提交
772 773

	arch_alloc_page(page, order);
L
Linus Torvalds 已提交
774
	kernel_map_pages(page, 1 << order, 1);
N
Nick Piggin 已提交
775 776 777 778 779 780 781

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

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

782
	return 0;
L
Linus Torvalds 已提交
783 784
}

785 786 787 788
/*
 * Go through the free lists for the given migratetype and remove
 * the smallest available page from the freelists
 */
789 790
static inline
struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815
						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;
}


816 817 818 819 820
/*
 * 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] = {
821 822 823 824
	[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 */
825 826
};

827 828
/*
 * Move the free pages in a range to the free lists of the requested type.
829
 * Note that start_page and end_pages are not aligned on a pageblock
830 831
 * boundary. If alignment is required, use move_freepages_block()
 */
A
Adrian Bunk 已提交
832 833 834
static int move_freepages(struct zone *zone,
			  struct page *start_page, struct page *end_page,
			  int migratetype)
835 836 837
{
	struct page *page;
	unsigned long order;
838
	int pages_moved = 0;
839 840 841 842 843 844 845

#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
846
	 * grouping pages by mobility
847 848 849 850 851
	 */
	BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif

	for (page = start_page; page <= end_page;) {
852 853 854
		/* Make sure we are not inadvertently changing nodes */
		VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));

855 856 857 858 859 860 861 862 863 864 865 866 867 868 869
		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;
870
		pages_moved += 1 << order;
871 872
	}

873
	return pages_moved;
874 875
}

A
Adrian Bunk 已提交
876 877
static int move_freepages_block(struct zone *zone, struct page *page,
				int migratetype)
878 879 880 881 882
{
	unsigned long start_pfn, end_pfn;
	struct page *start_page, *end_page;

	start_pfn = page_to_pfn(page);
883
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
884
	start_page = pfn_to_page(start_pfn);
885 886
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
887 888 889 890 891 892 893 894 895 896

	/* 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);
}

897 898 899 900 901 902 903 904 905 906 907
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;
	}
}

908
/* Remove an element from the buddy allocator from the fallback list */
909 910
static inline struct page *
__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
911 912 913 914 915 916 917 918 919 920 921 922
{
	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];

923 924 925
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
				continue;
M
Mel Gorman 已提交
926

927 928 929 930 931 932 933 934 935
			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--;

			/*
936
			 * If breaking a large block of pages, move all free
937 938 939
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
			 * agressive about taking ownership of free pages
940
			 */
941
			if (unlikely(current_order >= (pageblock_order >> 1)) ||
942 943
					start_migratetype == MIGRATE_RECLAIMABLE ||
					page_group_by_mobility_disabled) {
944 945 946 947 948
				unsigned long pages;
				pages = move_freepages_block(zone, page,
								start_migratetype);

				/* Claim the whole block if over half of it is free */
949 950
				if (pages >= (1 << (pageblock_order-1)) ||
						page_group_by_mobility_disabled)
951 952 953
					set_pageblock_migratetype(page,
								start_migratetype);

954
				migratetype = start_migratetype;
955
			}
956 957 958 959 960

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

961 962 963
			/* Take ownership for orders >= pageblock_order */
			if (current_order >= pageblock_order)
				change_pageblock_range(page, current_order,
964 965 966
							start_migratetype);

			expand(zone, page, order, current_order, area, migratetype);
967 968 969 970

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

971 972 973 974
			return page;
		}
	}

975
	return NULL;
976 977
}

978
/*
L
Linus Torvalds 已提交
979 980 981
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
982 983
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
L
Linus Torvalds 已提交
984 985 986
{
	struct page *page;

987
retry_reserve:
988
	page = __rmqueue_smallest(zone, order, migratetype);
989

990
	if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
991
		page = __rmqueue_fallback(zone, order, migratetype);
992

993 994 995 996 997 998 999 1000 1001 1002 1003
		/*
		 * 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;
		}
	}

1004
	trace_mm_page_alloc_zone_locked(page, order, migratetype);
1005
	return page;
L
Linus Torvalds 已提交
1006 1007 1008 1009 1010 1011 1012 1013
}

/* 
 * 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, 
1014
			unsigned long count, struct list_head *list,
1015
			int migratetype, int cold)
L
Linus Torvalds 已提交
1016 1017 1018
{
	int i;
	
N
Nick Piggin 已提交
1019
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
1020
	for (i = 0; i < count; ++i) {
1021
		struct page *page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1022
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
1023
			break;
1024 1025 1026 1027 1028 1029 1030 1031 1032 1033

		/*
		 * 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.
		 */
1034 1035 1036 1037
		if (likely(cold == 0))
			list_add(&page->lru, list);
		else
			list_add_tail(&page->lru, list);
1038
		set_page_private(page, migratetype);
1039
		list = &page->lru;
L
Linus Torvalds 已提交
1040
	}
1041
	__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
N
Nick Piggin 已提交
1042
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
1043
	return i;
L
Linus Torvalds 已提交
1044 1045
}

1046
#ifdef CONFIG_NUMA
1047
/*
1048 1049 1050 1051
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
1052 1053
 * Note that this function must be called with the thread pinned to
 * a single processor.
1054
 */
1055
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1056 1057
{
	unsigned long flags;
1058
	int to_drain;
1059

1060 1061 1062 1063 1064
	local_irq_save(flags);
	if (pcp->count >= pcp->batch)
		to_drain = pcp->batch;
	else
		to_drain = pcp->count;
1065
	free_pcppages_bulk(zone, to_drain, pcp);
1066 1067
	pcp->count -= to_drain;
	local_irq_restore(flags);
1068 1069 1070
}
#endif

1071 1072 1073 1074 1075 1076 1077 1078
/*
 * 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
1079
{
N
Nick Piggin 已提交
1080
	unsigned long flags;
L
Linus Torvalds 已提交
1081 1082
	struct zone *zone;

1083
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
1084
		struct per_cpu_pageset *pset;
1085
		struct per_cpu_pages *pcp;
L
Linus Torvalds 已提交
1086

1087 1088
		local_irq_save(flags);
		pset = per_cpu_ptr(zone->pageset, cpu);
1089 1090

		pcp = &pset->pcp;
1091
		free_pcppages_bulk(zone, pcp->count, pcp);
1092 1093
		pcp->count = 0;
		local_irq_restore(flags);
L
Linus Torvalds 已提交
1094 1095 1096
	}
}

1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109
/*
 * 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)
{
1110
	on_each_cpu(drain_local_pages, NULL, 1);
1111 1112
}

1113
#ifdef CONFIG_HIBERNATION
L
Linus Torvalds 已提交
1114 1115 1116

void mark_free_pages(struct zone *zone)
{
1117 1118
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
1119
	int order, t;
L
Linus Torvalds 已提交
1120 1121 1122 1123 1124 1125
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
1126 1127 1128 1129 1130 1131

	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);

1132 1133
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
1134
		}
L
Linus Torvalds 已提交
1135

1136 1137
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
1138
			unsigned long i;
L
Linus Torvalds 已提交
1139

1140 1141
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
1142
				swsusp_set_page_free(pfn_to_page(pfn + i));
1143
		}
1144
	}
L
Linus Torvalds 已提交
1145 1146
	spin_unlock_irqrestore(&zone->lock, flags);
}
1147
#endif /* CONFIG_PM */
L
Linus Torvalds 已提交
1148 1149 1150

/*
 * Free a 0-order page
L
Li Hong 已提交
1151
 * cold == 1 ? free a cold page : free a hot page
L
Linus Torvalds 已提交
1152
 */
L
Li Hong 已提交
1153
void free_hot_cold_page(struct page *page, int cold)
L
Linus Torvalds 已提交
1154 1155 1156 1157
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;
1158
	int migratetype;
1159
	int wasMlocked = __TestClearPageMlocked(page);
L
Linus Torvalds 已提交
1160

1161
	if (!free_pages_prepare(page, 0))
1162 1163
		return;

1164 1165
	migratetype = get_pageblock_migratetype(page);
	set_page_private(page, migratetype);
L
Linus Torvalds 已提交
1166
	local_irq_save(flags);
1167
	if (unlikely(wasMlocked))
1168
		free_page_mlock(page);
1169
	__count_vm_event(PGFREE);
1170

1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185
	/*
	 * 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;
	}

1186
	pcp = &this_cpu_ptr(zone->pageset)->pcp;
1187
	if (cold)
1188
		list_add_tail(&page->lru, &pcp->lists[migratetype]);
1189
	else
1190
		list_add(&page->lru, &pcp->lists[migratetype]);
L
Linus Torvalds 已提交
1191
	pcp->count++;
N
Nick Piggin 已提交
1192
	if (pcp->count >= pcp->high) {
1193
		free_pcppages_bulk(zone, pcp->batch, pcp);
N
Nick Piggin 已提交
1194 1195
		pcp->count -= pcp->batch;
	}
1196 1197

out:
L
Linus Torvalds 已提交
1198 1199 1200
	local_irq_restore(flags);
}

N
Nick Piggin 已提交
1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212
/*
 * 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
1213 1214
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1215 1216 1217 1218 1219 1220 1221 1222 1223 1224

#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

1225 1226
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
1227 1228
}

1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273
/*
 * Similar to split_page except the page is already free. As this is only
 * being used for migration, the migratetype of the block also changes.
 * As this is called with interrupts disabled, the caller is responsible
 * for calling arch_alloc_page() and kernel_map_page() after interrupts
 * are enabled.
 *
 * Note: this is probably too low level an operation for use in drivers.
 * Please consult with lkml before using this in your driver.
 */
int split_free_page(struct page *page)
{
	unsigned int order;
	unsigned long watermark;
	struct zone *zone;

	BUG_ON(!PageBuddy(page));

	zone = page_zone(page);
	order = page_order(page);

	/* Obey watermarks as if the page was being allocated */
	watermark = low_wmark_pages(zone) + (1 << order);
	if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
		return 0;

	/* Remove page from free list */
	list_del(&page->lru);
	zone->free_area[order].nr_free--;
	rmv_page_order(page);
	__mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));

	/* Split into individual pages */
	set_page_refcounted(page);
	split_page(page, order);

	if (order >= pageblock_order - 1) {
		struct page *endpage = page + (1 << order) - 1;
		for (; page < endpage; page += pageblock_nr_pages)
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
	}

	return 1 << order;
}

L
Linus Torvalds 已提交
1274 1275 1276 1277 1278
/*
 * 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.
 */
1279 1280
static inline
struct page *buffered_rmqueue(struct zone *preferred_zone,
1281 1282
			struct zone *zone, int order, gfp_t gfp_flags,
			int migratetype)
L
Linus Torvalds 已提交
1283 1284
{
	unsigned long flags;
1285
	struct page *page;
L
Linus Torvalds 已提交
1286 1287
	int cold = !!(gfp_flags & __GFP_COLD);

1288
again:
N
Nick Piggin 已提交
1289
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1290
		struct per_cpu_pages *pcp;
1291
		struct list_head *list;
L
Linus Torvalds 已提交
1292 1293

		local_irq_save(flags);
1294 1295
		pcp = &this_cpu_ptr(zone->pageset)->pcp;
		list = &pcp->lists[migratetype];
1296
		if (list_empty(list)) {
1297
			pcp->count += rmqueue_bulk(zone, 0,
1298
					pcp->batch, list,
1299
					migratetype, cold);
1300
			if (unlikely(list_empty(list)))
1301
				goto failed;
1302
		}
1303

1304 1305 1306 1307 1308
		if (cold)
			page = list_entry(list->prev, struct page, lru);
		else
			page = list_entry(list->next, struct page, lru);

1309 1310
		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1311
	} else {
1312 1313 1314 1315 1316 1317 1318 1319
		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
1320
			 * allocate greater than order-1 page units with
1321 1322
			 * __GFP_NOFAIL.
			 */
1323
			WARN_ON_ONCE(order > 1);
1324
		}
L
Linus Torvalds 已提交
1325
		spin_lock_irqsave(&zone->lock, flags);
1326
		page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1327 1328 1329
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
1330
		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
L
Linus Torvalds 已提交
1331 1332
	}

1333
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1334
	zone_statistics(preferred_zone, zone);
N
Nick Piggin 已提交
1335
	local_irq_restore(flags);
L
Linus Torvalds 已提交
1336

N
Nick Piggin 已提交
1337
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1338
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1339
		goto again;
L
Linus Torvalds 已提交
1340
	return page;
N
Nick Piggin 已提交
1341 1342 1343 1344

failed:
	local_irq_restore(flags);
	return NULL;
L
Linus Torvalds 已提交
1345 1346
}

1347 1348 1349 1350 1351 1352 1353 1354 1355
/* 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)

1356 1357 1358
#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
1359

1360 1361 1362 1363 1364 1365 1366
#ifdef CONFIG_FAIL_PAGE_ALLOC

static struct fail_page_alloc_attr {
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1367
	u32 min_order;
1368 1369 1370 1371 1372

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

	struct dentry *ignore_gfp_highmem_file;
	struct dentry *ignore_gfp_wait_file;
1373
	struct dentry *min_order_file;
1374 1375 1376 1377 1378

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1379 1380
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1381
	.min_order = 1,
1382 1383 1384 1385 1386 1387 1388 1389 1390 1391
};

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)
{
1392 1393
	if (order < fail_page_alloc.min_order)
		return 0;
1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424
	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);
1425 1426 1427
	fail_page_alloc.min_order_file =
		debugfs_create_u32("min-order", mode, dir,
				   &fail_page_alloc.min_order);
1428 1429

	if (!fail_page_alloc.ignore_gfp_wait_file ||
1430 1431
            !fail_page_alloc.ignore_gfp_highmem_file ||
            !fail_page_alloc.min_order_file) {
1432 1433 1434
		err = -ENOMEM;
		debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
		debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1435
		debugfs_remove(fail_page_alloc.min_order_file);
1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454
		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
1455 1456 1457 1458 1459
/*
 * 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
1460
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
1461 1462
{
	/* free_pages my go negative - that's OK */
1463 1464
	long min = mark;
	long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
L
Linus Torvalds 已提交
1465 1466
	int o;

R
Rohit Seth 已提交
1467
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1468
		min -= min / 2;
R
Rohit Seth 已提交
1469
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486
		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;
}

1487 1488 1489 1490 1491 1492
#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
1493
 * that have to skip over a lot of full or unallowed zones.
1494 1495 1496
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1497
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518
 *
 * 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
1519
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1520 1521 1522 1523 1524 1525
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1526
					&node_states[N_HIGH_MEMORY];
1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551
	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.
 */
1552
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1553 1554 1555 1556 1557 1558 1559 1560 1561 1562
						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;

1563
	i = z - zonelist->_zonerefs;
1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574
	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.
 */
1575
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1576 1577 1578 1579 1580 1581 1582 1583
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

1584
	i = z - zonelist->_zonerefs;
1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

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

1596
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1597 1598 1599 1600 1601
				nodemask_t *allowednodes)
{
	return 1;
}

1602
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1603 1604 1605 1606
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1607
/*
1608
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1609 1610 1611
 * a page.
 */
static struct page *
1612
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1613
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1614
		struct zone *preferred_zone, int migratetype)
M
Martin Hicks 已提交
1615
{
1616
	struct zoneref *z;
R
Rohit Seth 已提交
1617
	struct page *page = NULL;
1618
	int classzone_idx;
1619
	struct zone *zone;
1620 1621 1622
	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 */
1623

1624
	classzone_idx = zone_idx(preferred_zone);
1625
zonelist_scan:
R
Rohit Seth 已提交
1626
	/*
1627
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1628 1629
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1630 1631
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1632 1633 1634
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1635
		if ((alloc_flags & ALLOC_CPUSET) &&
1636
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1637
				goto try_next_zone;
R
Rohit Seth 已提交
1638

1639
		BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
R
Rohit Seth 已提交
1640
		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1641
			unsigned long mark;
1642 1643
			int ret;

1644
			mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663
			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))
1664
					goto this_zone_full;
1665
			}
R
Rohit Seth 已提交
1666 1667
		}

1668
try_this_zone:
1669 1670
		page = buffered_rmqueue(preferred_zone, zone, order,
						gfp_mask, migratetype);
1671
		if (page)
R
Rohit Seth 已提交
1672
			break;
1673 1674 1675 1676
this_zone_full:
		if (NUMA_BUILD)
			zlc_mark_zone_full(zonelist, z);
try_next_zone:
1677
		if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1678 1679 1680 1681
			/*
			 * we do zlc_setup after the first zone is tried but only
			 * if there are multiple nodes make it worthwhile
			 */
1682 1683 1684 1685
			allowednodes = zlc_setup(zonelist, alloc_flags);
			zlc_active = 1;
			did_zlc_setup = 1;
		}
1686
	}
1687 1688 1689 1690 1691 1692

	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
1693
	return page;
M
Martin Hicks 已提交
1694 1695
}

1696 1697 1698
static inline int
should_alloc_retry(gfp_t gfp_mask, unsigned int order,
				unsigned long pages_reclaimed)
L
Linus Torvalds 已提交
1699
{
1700 1701 1702
	/* Do not loop if specifically requested */
	if (gfp_mask & __GFP_NORETRY)
		return 0;
L
Linus Torvalds 已提交
1703

1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720
	/*
	 * 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;
1721

1722 1723 1724 1725 1726 1727
	/*
	 * 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
1728

1729 1730
	return 0;
}
1731

1732 1733 1734
static inline struct page *
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1735 1736
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1737 1738 1739 1740 1741 1742
{
	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
1743 1744
		return NULL;
	}
1745

1746 1747 1748 1749 1750 1751 1752
	/*
	 * 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,
1753
		ALLOC_WMARK_HIGH|ALLOC_CPUSET,
1754
		preferred_zone, migratetype);
R
Rohit Seth 已提交
1755
	if (page)
1756 1757
		goto out;

1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771
	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;
	}
1772
	/* Exhausted what can be done so it's blamo time */
1773
	out_of_memory(zonelist, gfp_mask, order, nodemask);
1774 1775 1776 1777 1778 1779

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

1780 1781 1782 1783 1784 1785 1786 1787 1788 1789
#ifdef CONFIG_COMPACTION
/* Try memory compaction for high-order allocations before reclaim */
static struct page *
__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
	int migratetype, unsigned long *did_some_progress)
{
	struct page *page;

1790
	if (!order || compaction_deferred(preferred_zone))
1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805
		return NULL;

	*did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
								nodemask);
	if (*did_some_progress != COMPACT_SKIPPED) {

		/* Page migration frees to the PCP lists but we want merging */
		drain_pages(get_cpu());
		put_cpu();

		page = get_page_from_freelist(gfp_mask, nodemask,
				order, zonelist, high_zoneidx,
				alloc_flags, preferred_zone,
				migratetype);
		if (page) {
1806 1807
			preferred_zone->compact_considered = 0;
			preferred_zone->compact_defer_shift = 0;
1808 1809 1810 1811 1812 1813 1814 1815 1816 1817
			count_vm_event(COMPACTSUCCESS);
			return page;
		}

		/*
		 * It's bad if compaction run occurs and fails.
		 * The most likely reason is that pages exist,
		 * but not enough to satisfy watermarks.
		 */
		count_vm_event(COMPACTFAIL);
1818
		defer_compaction(preferred_zone);
1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835

		cond_resched();
	}

	return NULL;
}
#else
static inline struct page *
__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
	int migratetype, unsigned long *did_some_progress)
{
	return NULL;
}
#endif /* CONFIG_COMPACTION */

1836 1837 1838 1839
/* 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,
1840
	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1841
	int migratetype, unsigned long *did_some_progress)
1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868
{
	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,
1869
					zonelist, high_zoneidx,
1870 1871
					alloc_flags, preferred_zone,
					migratetype);
1872 1873 1874
	return page;
}

L
Linus Torvalds 已提交
1875
/*
1876 1877
 * 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
1878
 */
1879 1880 1881
static inline struct page *
__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1882 1883
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1884 1885 1886 1887 1888
{
	struct page *page;

	do {
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1889
			zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
1890
			preferred_zone, migratetype);
1891 1892

		if (!page && gfp_mask & __GFP_NOFAIL)
1893
			congestion_wait(BLK_RW_ASYNC, HZ/50);
1894 1895 1896 1897 1898 1899 1900 1901
	} 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
1902
{
1903 1904
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
1905

1906 1907 1908
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
		wakeup_kswapd(zone, order);
}
1909

1910 1911 1912 1913 1914 1915
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
1916

1917 1918
	/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
	BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH);
1919

1920 1921 1922 1923 1924 1925
	/*
	 * 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).
	 */
1926
	alloc_flags |= (gfp_mask & __GFP_HIGH);
L
Linus Torvalds 已提交
1927

1928 1929
	if (!wait) {
		alloc_flags |= ALLOC_HARDER;
1930
		/*
1931 1932
		 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
		 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1933
		 */
1934
		alloc_flags &= ~ALLOC_CPUSET;
1935
	} else if (unlikely(rt_task(p)) && !in_interrupt())
1936 1937 1938 1939 1940 1941 1942
		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
1943
	}
1944

1945 1946 1947
	return alloc_flags;
}

1948 1949 1950
static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1951 1952
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1953 1954 1955 1956 1957 1958 1959
{
	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
1960

1961 1962 1963 1964 1965 1966
	/*
	 * 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.
	 */
1967 1968
	if (order >= MAX_ORDER) {
		WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
1969
		return NULL;
1970
	}
L
Linus Torvalds 已提交
1971

1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982
	/*
	 * 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;

1983
restart:
1984
	wake_all_kswapd(order, zonelist, high_zoneidx);
L
Linus Torvalds 已提交
1985

1986
	/*
R
Rohit Seth 已提交
1987 1988 1989
	 * 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.
1990
	 */
1991
	alloc_flags = gfp_to_alloc_flags(gfp_mask);
L
Linus Torvalds 已提交
1992

1993
	/* This is the last chance, in general, before the goto nopage. */
1994
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1995 1996
			high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
			preferred_zone, migratetype);
R
Rohit Seth 已提交
1997 1998
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1999

2000
rebalance:
2001
	/* Allocate without watermarks if the context allows */
2002 2003 2004 2005 2006 2007
	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
2008 2009 2010 2011 2012 2013
	}

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

2014 2015 2016 2017
	/* Avoid recursion of direct reclaim */
	if (p->flags & PF_MEMALLOC)
		goto nopage;

2018 2019 2020 2021
	/* Avoid allocations with no watermarks from looping endlessly */
	if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
		goto nopage;

2022 2023 2024 2025 2026 2027 2028 2029 2030
	/* Try direct compaction */
	page = __alloc_pages_direct_compact(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
					alloc_flags, preferred_zone,
					migratetype, &did_some_progress);
	if (page)
		goto got_pg;

2031 2032 2033 2034
	/* Try direct reclaim and then allocating */
	page = __alloc_pages_direct_reclaim(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
2035
					alloc_flags, preferred_zone,
2036
					migratetype, &did_some_progress);
2037 2038
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
2039

2040
	/*
2041 2042
	 * If we failed to make any progress reclaiming, then we are
	 * running out of options and have to consider going OOM
2043
	 */
2044 2045
	if (!did_some_progress) {
		if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
2046 2047
			if (oom_killer_disabled)
				goto nopage;
2048 2049
			page = __alloc_pages_may_oom(gfp_mask, order,
					zonelist, high_zoneidx,
2050 2051
					nodemask, preferred_zone,
					migratetype);
2052 2053
			if (page)
				goto got_pg;
L
Linus Torvalds 已提交
2054

2055
			/*
2056 2057 2058 2059
			 * 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.
2060
			 */
2061 2062
			if (order > PAGE_ALLOC_COSTLY_ORDER &&
						!(gfp_mask & __GFP_NOFAIL))
2063
				goto nopage;
2064

2065 2066
			goto restart;
		}
L
Linus Torvalds 已提交
2067 2068
	}

2069
	/* Check if we should retry the allocation */
2070
	pages_reclaimed += did_some_progress;
2071 2072
	if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
		/* Wait for some write requests to complete then retry */
2073
		congestion_wait(BLK_RW_ASYNC, HZ/50);
L
Linus Torvalds 已提交
2074 2075 2076 2077 2078 2079 2080 2081 2082
		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
2083
		show_mem();
L
Linus Torvalds 已提交
2084
	}
2085
	return page;
L
Linus Torvalds 已提交
2086
got_pg:
2087 2088
	if (kmemcheck_enabled)
		kmemcheck_pagealloc_alloc(page, order, gfp_mask);
L
Linus Torvalds 已提交
2089
	return page;
2090

L
Linus Torvalds 已提交
2091
}
2092 2093 2094 2095 2096 2097 2098 2099 2100

/*
 * 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);
2101
	struct zone *preferred_zone;
2102
	struct page *page;
2103
	int migratetype = allocflags_to_migratetype(gfp_mask);
2104

2105 2106
	gfp_mask &= gfp_allowed_mask;

2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121
	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;

2122
	get_mems_allowed();
2123 2124
	/* The preferred zone is used for statistics later */
	first_zones_zonelist(zonelist, high_zoneidx, nodemask, &preferred_zone);
2125 2126
	if (!preferred_zone) {
		put_mems_allowed();
2127
		return NULL;
2128
	}
2129 2130

	/* First allocation attempt */
2131
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
2132
			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
2133
			preferred_zone, migratetype);
2134 2135
	if (unlikely(!page))
		page = __alloc_pages_slowpath(gfp_mask, order,
2136
				zonelist, high_zoneidx, nodemask,
2137
				preferred_zone, migratetype);
2138
	put_mems_allowed();
2139

2140
	trace_mm_page_alloc(page, order, gfp_mask, migratetype);
2141
	return page;
L
Linus Torvalds 已提交
2142
}
2143
EXPORT_SYMBOL(__alloc_pages_nodemask);
L
Linus Torvalds 已提交
2144 2145 2146 2147

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
2148
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
2149
{
2150 2151 2152 2153 2154 2155 2156 2157
	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
2158 2159 2160 2161 2162 2163 2164
	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
2165
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
2166
{
2167
	return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
L
Linus Torvalds 已提交
2168 2169 2170 2171 2172 2173 2174
}
EXPORT_SYMBOL(get_zeroed_page);

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

2175 2176
	while (--i >= 0) {
		trace_mm_pagevec_free(pvec->pages[i], pvec->cold);
L
Linus Torvalds 已提交
2177
		free_hot_cold_page(pvec->pages[i], pvec->cold);
2178
	}
L
Linus Torvalds 已提交
2179 2180
}

H
Harvey Harrison 已提交
2181
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
2182
{
N
Nick Piggin 已提交
2183
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
2184
		if (order == 0)
L
Li Hong 已提交
2185
			free_hot_cold_page(page, 0);
L
Linus Torvalds 已提交
2186 2187 2188 2189 2190 2191 2192
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
2193
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
2194 2195
{
	if (addr != 0) {
N
Nick Piggin 已提交
2196
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
2197 2198 2199 2200 2201 2202
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225
/**
 * 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
2226
		split_page(virt_to_page((void *)addr), order);
2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255
		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
2256 2257
static unsigned int nr_free_zone_pages(int offset)
{
2258
	struct zoneref *z;
2259 2260
	struct zone *zone;

2261
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
2262 2263
	unsigned int sum = 0;

2264
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
2265

2266
	for_each_zone_zonelist(zone, z, zonelist, offset) {
2267
		unsigned long size = zone->present_pages;
2268
		unsigned long high = high_wmark_pages(zone);
2269 2270
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
2271 2272 2273 2274 2275 2276 2277 2278 2279 2280
	}

	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
2281
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
2282
}
2283
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
2284 2285 2286 2287 2288 2289

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
2290
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
2291
}
2292 2293

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
2294
{
2295
	if (NUMA_BUILD)
2296
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
2297 2298 2299 2300 2301 2302
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
2303
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317
	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;
2318
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
2319
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2320
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2321 2322
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
2323 2324 2325 2326
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339
	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)
{
2340
	int cpu;
L
Linus Torvalds 已提交
2341 2342
	struct zone *zone;

2343
	for_each_populated_zone(zone) {
2344 2345
		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
2346

2347
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
2348 2349
			struct per_cpu_pageset *pageset;

2350
			pageset = per_cpu_ptr(zone->pageset, cpu);
L
Linus Torvalds 已提交
2351

2352 2353 2354
			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
2355 2356 2357
		}
	}

K
KOSAKI Motohiro 已提交
2358 2359
	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
2360
		" unevictable:%lu"
2361
		" dirty:%lu writeback:%lu unstable:%lu\n"
2362
		" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2363
		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2364 2365
		global_page_state(NR_ACTIVE_ANON),
		global_page_state(NR_INACTIVE_ANON),
K
KOSAKI Motohiro 已提交
2366 2367
		global_page_state(NR_ISOLATED_ANON),
		global_page_state(NR_ACTIVE_FILE),
2368
		global_page_state(NR_INACTIVE_FILE),
K
KOSAKI Motohiro 已提交
2369
		global_page_state(NR_ISOLATED_FILE),
L
Lee Schermerhorn 已提交
2370
		global_page_state(NR_UNEVICTABLE),
2371
		global_page_state(NR_FILE_DIRTY),
2372
		global_page_state(NR_WRITEBACK),
2373
		global_page_state(NR_UNSTABLE_NFS),
2374
		global_page_state(NR_FREE_PAGES),
2375 2376
		global_page_state(NR_SLAB_RECLAIMABLE),
		global_page_state(NR_SLAB_UNRECLAIMABLE),
2377
		global_page_state(NR_FILE_MAPPED),
2378
		global_page_state(NR_SHMEM),
2379 2380
		global_page_state(NR_PAGETABLE),
		global_page_state(NR_BOUNCE));
L
Linus Torvalds 已提交
2381

2382
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
2383 2384 2385 2386 2387 2388 2389 2390
		int i;

		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
2391 2392 2393 2394
			" active_anon:%lukB"
			" inactive_anon:%lukB"
			" active_file:%lukB"
			" inactive_file:%lukB"
L
Lee Schermerhorn 已提交
2395
			" unevictable:%lukB"
K
KOSAKI Motohiro 已提交
2396 2397
			" isolated(anon):%lukB"
			" isolated(file):%lukB"
L
Linus Torvalds 已提交
2398
			" present:%lukB"
2399 2400 2401 2402
			" mlocked:%lukB"
			" dirty:%lukB"
			" writeback:%lukB"
			" mapped:%lukB"
2403
			" shmem:%lukB"
2404 2405
			" slab_reclaimable:%lukB"
			" slab_unreclaimable:%lukB"
2406
			" kernel_stack:%lukB"
2407 2408 2409 2410
			" pagetables:%lukB"
			" unstable:%lukB"
			" bounce:%lukB"
			" writeback_tmp:%lukB"
L
Linus Torvalds 已提交
2411 2412 2413 2414
			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
2415
			K(zone_page_state(zone, NR_FREE_PAGES)),
2416 2417 2418
			K(min_wmark_pages(zone)),
			K(low_wmark_pages(zone)),
			K(high_wmark_pages(zone)),
2419 2420 2421 2422
			K(zone_page_state(zone, NR_ACTIVE_ANON)),
			K(zone_page_state(zone, NR_INACTIVE_ANON)),
			K(zone_page_state(zone, NR_ACTIVE_FILE)),
			K(zone_page_state(zone, NR_INACTIVE_FILE)),
L
Lee Schermerhorn 已提交
2423
			K(zone_page_state(zone, NR_UNEVICTABLE)),
K
KOSAKI Motohiro 已提交
2424 2425
			K(zone_page_state(zone, NR_ISOLATED_ANON)),
			K(zone_page_state(zone, NR_ISOLATED_FILE)),
L
Linus Torvalds 已提交
2426
			K(zone->present_pages),
2427 2428 2429 2430
			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)),
2431
			K(zone_page_state(zone, NR_SHMEM)),
2432 2433
			K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
			K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
2434 2435
			zone_page_state(zone, NR_KERNEL_STACK) *
				THREAD_SIZE / 1024,
2436 2437 2438 2439
			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
Linus Torvalds 已提交
2440
			zone->pages_scanned,
2441
			(zone->all_unreclaimable ? "yes" : "no")
L
Linus Torvalds 已提交
2442 2443 2444 2445 2446 2447 2448
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

2449
	for_each_populated_zone(zone) {
2450
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
L
Linus Torvalds 已提交
2451 2452 2453 2454 2455 2456

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

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
2457 2458
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
L
Linus Torvalds 已提交
2459 2460
		}
		spin_unlock_irqrestore(&zone->lock, flags);
2461 2462
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
L
Linus Torvalds 已提交
2463 2464 2465
		printk("= %lukB\n", K(total));
	}

2466 2467
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

L
Linus Torvalds 已提交
2468 2469 2470
	show_swap_cache_info();
}

2471 2472 2473 2474 2475 2476
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
{
	zoneref->zone = zone;
	zoneref->zone_idx = zone_idx(zone);
}

L
Linus Torvalds 已提交
2477 2478
/*
 * Builds allocation fallback zone lists.
2479 2480
 *
 * Add all populated zones of a node to the zonelist.
L
Linus Torvalds 已提交
2481
 */
2482 2483
static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
				int nr_zones, enum zone_type zone_type)
L
Linus Torvalds 已提交
2484
{
2485 2486
	struct zone *zone;

2487
	BUG_ON(zone_type >= MAX_NR_ZONES);
2488
	zone_type++;
2489 2490

	do {
2491
		zone_type--;
2492
		zone = pgdat->node_zones + zone_type;
2493
		if (populated_zone(zone)) {
2494 2495
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
2496
			check_highest_zone(zone_type);
L
Linus Torvalds 已提交
2497
		}
2498

2499
	} while (zone_type);
2500
	return nr_zones;
L
Linus Torvalds 已提交
2501 2502
}

2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523

/*
 *  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
2524
#ifdef CONFIG_NUMA
2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567
/* 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,
2568
		void __user *buffer, size_t *length,
2569 2570 2571 2572
		loff_t *ppos)
{
	char saved_string[NUMA_ZONELIST_ORDER_LEN];
	int ret;
2573
	static DEFINE_MUTEX(zl_order_mutex);
2574

2575
	mutex_lock(&zl_order_mutex);
2576
	if (write)
2577
		strcpy(saved_string, (char*)table->data);
2578
	ret = proc_dostring(table, write, buffer, length, ppos);
2579
	if (ret)
2580
		goto out;
2581 2582 2583 2584 2585 2586 2587 2588 2589
	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;
2590 2591
		} else if (oldval != user_zonelist_order) {
			mutex_lock(&zonelists_mutex);
2592
			build_all_zonelists(NULL);
2593 2594
			mutex_unlock(&zonelists_mutex);
		}
2595
	}
2596 2597 2598
out:
	mutex_unlock(&zl_order_mutex);
	return ret;
2599 2600 2601
}


2602
#define MAX_NODE_LOAD (nr_online_nodes)
2603 2604
static int node_load[MAX_NUMNODES];

L
Linus Torvalds 已提交
2605
/**
2606
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
Linus Torvalds 已提交
2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618
 * @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.
 */
2619
static int find_next_best_node(int node, nodemask_t *used_node_mask)
L
Linus Torvalds 已提交
2620
{
2621
	int n, val;
L
Linus Torvalds 已提交
2622 2623
	int min_val = INT_MAX;
	int best_node = -1;
2624
	const struct cpumask *tmp = cpumask_of_node(0);
L
Linus Torvalds 已提交
2625

2626 2627 2628 2629 2630
	/* 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
2631

2632
	for_each_node_state(n, N_HIGH_MEMORY) {
L
Linus Torvalds 已提交
2633 2634 2635 2636 2637 2638 2639 2640

		/* 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);

2641 2642 2643
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
Linus Torvalds 已提交
2644
		/* Give preference to headless and unused nodes */
2645 2646
		tmp = cpumask_of_node(n);
		if (!cpumask_empty(tmp))
L
Linus Torvalds 已提交
2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664
			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;
}

2665 2666 2667 2668 2669 2670 2671

/*
 * 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
2672
{
2673
	int j;
L
Linus Torvalds 已提交
2674
	struct zonelist *zonelist;
2675

2676
	zonelist = &pgdat->node_zonelists[0];
2677
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2678 2679 2680
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
2681 2682
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2683 2684
}

2685 2686 2687 2688 2689 2690 2691 2692
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

2693 2694
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2695 2696
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2697 2698
}

2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713
/*
 * 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;

2714 2715 2716 2717 2718 2719 2720
	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)) {
2721 2722
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
2723
				check_highest_zone(zone_type);
2724 2725 2726
			}
		}
	}
2727 2728
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
2729 2730 2731 2732 2733 2734 2735 2736 2737
}

static int default_zonelist_order(void)
{
	int nid, zone_type;
	unsigned long low_kmem_size,total_size;
	struct zone *z;
	int average_size;
	/*
T
Thomas Weber 已提交
2738
         * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
2739 2740
	 * If they are really small and used heavily, the system can fall
	 * into OOM very easily.
2741
	 * This function detect ZONE_DMA/DMA32 size and configures zone order.
2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752
	 */
	/* 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;
2753 2754 2755 2756 2757 2758 2759 2760 2761
			} else if (zone_type == ZONE_NORMAL) {
				/*
				 * If any node has only lowmem, then node order
				 * is preferred to allow kernel allocations
				 * locally; otherwise, they can easily infringe
				 * on other nodes when there is an abundance of
				 * lowmem available to allocate from.
				 */
				return ZONELIST_ORDER_NODE;
2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772
			}
		}
	}
	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.
         */
2773 2774
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805
	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
2806
	nodemask_t used_mask;
2807 2808 2809
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
L
Linus Torvalds 已提交
2810 2811

	/* initialize zonelists */
2812
	for (i = 0; i < MAX_ZONELISTS; i++) {
L
Linus Torvalds 已提交
2813
		zonelist = pgdat->node_zonelists + i;
2814 2815
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
L
Linus Torvalds 已提交
2816 2817 2818 2819
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
2820
	load = nr_online_nodes;
L
Linus Torvalds 已提交
2821 2822
	prev_node = local_node;
	nodes_clear(used_mask);
2823 2824 2825 2826

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

L
Linus Torvalds 已提交
2827
	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2828 2829 2830 2831 2832 2833 2834 2835 2836
		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
Linus Torvalds 已提交
2837 2838 2839 2840 2841
		/*
		 * 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.
		 */
2842
		if (distance != node_distance(local_node, prev_node))
2843 2844
			node_load[node] = load;

L
Linus Torvalds 已提交
2845 2846
		prev_node = node;
		load--;
2847 2848 2849 2850 2851
		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
2852

2853 2854 2855
	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
2856
	}
2857 2858

	build_thisnode_zonelists(pgdat);
L
Linus Torvalds 已提交
2859 2860
}

2861
/* Construct the zonelist performance cache - see further mmzone.h */
2862
static void build_zonelist_cache(pg_data_t *pgdat)
2863
{
2864 2865
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
2866
	struct zoneref *z;
2867

2868 2869 2870
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2871 2872
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2873 2874
}

2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892
#ifdef CONFIG_HAVE_MEMORYLESS_NODES
/*
 * Return node id of node used for "local" allocations.
 * I.e., first node id of first zone in arg node's generic zonelist.
 * Used for initializing percpu 'numa_mem', which is used primarily
 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
 */
int local_memory_node(int node)
{
	struct zone *zone;

	(void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
				   gfp_zone(GFP_KERNEL),
				   NULL,
				   &zone);
	return zone->node;
}
#endif
2893

L
Linus Torvalds 已提交
2894 2895
#else	/* CONFIG_NUMA */

2896 2897 2898 2899 2900 2901
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
2902
{
2903
	int node, local_node;
2904 2905
	enum zone_type j;
	struct zonelist *zonelist;
L
Linus Torvalds 已提交
2906 2907 2908

	local_node = pgdat->node_id;

2909 2910
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
2911

2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924
	/*
	 * 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
2925
	}
2926 2927 2928 2929 2930 2931 2932
	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);
	}

2933 2934
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
L
Linus Torvalds 已提交
2935 2936
}

2937
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2938
static void build_zonelist_cache(pg_data_t *pgdat)
2939
{
2940
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
2941 2942
}

L
Linus Torvalds 已提交
2943 2944
#endif	/* CONFIG_NUMA */

2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961
/*
 * 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.
 *
 * 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.
 */
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
2962
static void setup_zone_pageset(struct zone *zone);
2963

2964 2965 2966 2967 2968 2969
/*
 * Global mutex to protect against size modification of zonelists
 * as well as to serialize pageset setup for the new populated zone.
 */
DEFINE_MUTEX(zonelists_mutex);

2970
/* return values int ....just for stop_machine() */
2971
static __init_refok int __build_all_zonelists(void *data)
L
Linus Torvalds 已提交
2972
{
2973
	int nid;
2974
	int cpu;
2975

2976 2977 2978
#ifdef CONFIG_NUMA
	memset(node_load, 0, sizeof(node_load));
#endif
2979
	for_each_online_node(nid) {
2980 2981 2982 2983
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
2984
	}
2985

2986 2987 2988 2989 2990 2991 2992 2993
#ifdef CONFIG_MEMORY_HOTPLUG
	/* Setup real pagesets for the new zone */
	if (data) {
		struct zone *zone = data;
		setup_zone_pageset(zone);
	}
#endif

2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006
	/*
	 * Initialize the boot_pagesets that are going to be used
	 * for bootstrapping processors. The real pagesets for
	 * each zone will be allocated later when the per cpu
	 * allocator is available.
	 *
	 * boot_pagesets are used also for bootstrapping offline
	 * cpus if the system is already booted because the pagesets
	 * are needed to initialize allocators on a specific cpu too.
	 * F.e. the percpu allocator needs the page allocator which
	 * needs the percpu allocator in order to allocate its pagesets
	 * (a chicken-egg dilemma).
	 */
3007
	for_each_possible_cpu(cpu) {
3008 3009
		setup_pageset(&per_cpu(boot_pageset, cpu), 0);

3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023
#ifdef CONFIG_HAVE_MEMORYLESS_NODES
		/*
		 * We now know the "local memory node" for each node--
		 * i.e., the node of the first zone in the generic zonelist.
		 * Set up numa_mem percpu variable for on-line cpus.  During
		 * boot, only the boot cpu should be on-line;  we'll init the
		 * secondary cpus' numa_mem as they come on-line.  During
		 * node/memory hotplug, we'll fixup all on-line cpus.
		 */
		if (cpu_online(cpu))
			set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
#endif
	}

3024 3025 3026
	return 0;
}

3027 3028 3029 3030
/*
 * Called with zonelists_mutex held always
 * unless system_state == SYSTEM_BOOTING.
 */
3031
void build_all_zonelists(void *data)
3032
{
3033 3034
	set_zonelist_order();

3035
	if (system_state == SYSTEM_BOOTING) {
3036
		__build_all_zonelists(NULL);
3037
		mminit_verify_zonelist();
3038 3039
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
3040
		/* we have to stop all cpus to guarantee there is no user
3041
		   of zonelist */
3042
		stop_machine(__build_all_zonelists, data, NULL);
3043 3044
		/* cpuset refresh routine should be here */
	}
3045
	vm_total_pages = nr_free_pagecache_pages();
3046 3047 3048 3049 3050 3051 3052
	/*
	 * 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
	 */
3053
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
3054 3055 3056 3057 3058 3059
		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",
3060
			nr_online_nodes,
3061
			zonelist_order_name[current_zonelist_order],
3062
			page_group_by_mobility_disabled ? "off" : "on",
3063 3064 3065 3066
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
L
Linus Torvalds 已提交
3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081
}

/*
 * 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

3082
#ifndef CONFIG_MEMORY_HOTPLUG
3083
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100
{
	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);
}
3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123
#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
3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136

/*
 * 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))

3137
/*
3138
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3139 3140
 * 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
3141 3142 3143 3144 3145 3146 3147
 * 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;
3148 3149
	unsigned long block_migratetype;
	int reserve;
3150 3151 3152 3153

	/* 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;
3154
	reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
3155
							pageblock_order;
3156

3157 3158 3159 3160 3161 3162 3163 3164 3165
	/*
	 * 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);

3166
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
3167 3168 3169 3170
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

3171 3172 3173 3174
		/* Watch out for overlapping nodes */
		if (page_to_nid(page) != zone_to_nid(zone))
			continue;

3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204
		/* 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
3205

L
Linus Torvalds 已提交
3206 3207 3208 3209 3210
/*
 * 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.
 */
3211
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
3212
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
3213 3214
{
	struct page *page;
A
Andy Whitcroft 已提交
3215 3216
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
3217
	struct zone *z;
L
Linus Torvalds 已提交
3218

3219 3220 3221
	if (highest_memmap_pfn < end_pfn - 1)
		highest_memmap_pfn = end_pfn - 1;

3222
	z = &NODE_DATA(nid)->node_zones[zone];
3223
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234
		/*
		 * 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
3235 3236
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
3237
		mminit_verify_page_links(page, zone, nid, pfn);
3238
		init_page_count(page);
L
Linus Torvalds 已提交
3239 3240
		reset_page_mapcount(page);
		SetPageReserved(page);
3241 3242 3243 3244 3245
		/*
		 * 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
3246 3247 3248
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
3249 3250 3251 3252 3253
		 *
		 * 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.
3254
		 */
3255 3256 3257
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
3258
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
3259

L
Linus Torvalds 已提交
3260 3261 3262 3263
		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))
3264
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
3265 3266 3267 3268
#endif
	}
}

3269
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
3270
{
3271 3272 3273
	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
3274 3275 3276 3277 3278 3279
		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
3280
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
3281 3282
#endif

3283
static int zone_batchsize(struct zone *zone)
3284
{
3285
#ifdef CONFIG_MMU
3286 3287 3288 3289
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
3290
	 * size of the zone.  But no more than 1/2 of a meg.
3291 3292 3293 3294
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
3295 3296
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
3297 3298 3299 3300 3301
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
3302 3303 3304
	 * 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.
3305
	 *
3306 3307 3308 3309
	 * 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.
3310
	 */
3311
	batch = rounddown_pow_of_two(batch + batch/2) - 1;
3312

3313
	return batch;
3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330

#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
3331 3332
}

A
Adrian Bunk 已提交
3333
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3334 3335
{
	struct per_cpu_pages *pcp;
3336
	int migratetype;
3337

3338 3339
	memset(p, 0, sizeof(*p));

3340
	pcp = &p->pcp;
3341 3342 3343
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
3344 3345
	for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
		INIT_LIST_HEAD(&pcp->lists[migratetype]);
3346 3347
}

3348 3349 3350 3351 3352 3353 3354 3355 3356 3357
/*
 * 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;

3358
	pcp = &p->pcp;
3359 3360 3361 3362 3363 3364
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}

3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382
static __meminit void setup_zone_pageset(struct zone *zone)
{
	int cpu;

	zone->pageset = alloc_percpu(struct per_cpu_pageset);

	for_each_possible_cpu(cpu) {
		struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);

		setup_pageset(pcp, zone_batchsize(zone));

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(pcp,
				(zone->present_pages /
					percpu_pagelist_fraction));
	}
}

3383
/*
3384 3385
 * Allocate per cpu pagesets and initialize them.
 * Before this call only boot pagesets were available.
3386
 */
3387
void __init setup_per_cpu_pageset(void)
3388
{
3389
	struct zone *zone;
3390

3391 3392
	for_each_populated_zone(zone)
		setup_zone_pageset(zone);
3393 3394
}

S
Sam Ravnborg 已提交
3395
static noinline __init_refok
3396
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3397 3398 3399
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
3400
	size_t alloc_size;
3401 3402 3403 3404 3405

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
3406 3407 3408 3409
	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);
3410 3411 3412
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

3413
	if (!slab_is_available()) {
3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426
		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.
		 */
3427
		zone->wait_table = vmalloc(alloc_size);
3428 3429 3430
	}
	if (!zone->wait_table)
		return -ENOMEM;
3431

3432
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3433
		init_waitqueue_head(zone->wait_table + i);
3434 3435

	return 0;
3436 3437
}

3438 3439 3440 3441 3442 3443
static int __zone_pcp_update(void *data)
{
	struct zone *zone = data;
	int cpu;
	unsigned long batch = zone_batchsize(zone), flags;

3444
	for_each_possible_cpu(cpu) {
3445 3446 3447
		struct per_cpu_pageset *pset;
		struct per_cpu_pages *pcp;

3448
		pset = per_cpu_ptr(zone->pageset, cpu);
3449 3450 3451
		pcp = &pset->pcp;

		local_irq_save(flags);
3452
		free_pcppages_bulk(zone, pcp->count, pcp);
3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463
		setup_pageset(pset, batch);
		local_irq_restore(flags);
	}
	return 0;
}

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

3464
static __meminit void zone_pcp_init(struct zone *zone)
3465
{
3466 3467 3468 3469 3470 3471
	/*
	 * per cpu subsystem is not up at this point. The following code
	 * relies on the ability of the linker to provide the
	 * offset of a (static) per cpu variable into the per cpu area.
	 */
	zone->pageset = &boot_pageset;
3472

A
Anton Blanchard 已提交
3473
	if (zone->present_pages)
3474 3475 3476
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%u\n",
			zone->name, zone->present_pages,
					 zone_batchsize(zone));
3477 3478
}

3479 3480
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
3481 3482
					unsigned long size,
					enum memmap_context context)
3483 3484
{
	struct pglist_data *pgdat = zone->zone_pgdat;
3485 3486 3487 3488
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
3489 3490 3491 3492
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

3493 3494 3495 3496 3497 3498
	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));

3499
	zone_init_free_lists(zone);
3500 3501

	return 0;
3502 3503
}

3504 3505 3506 3507 3508
#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
 */
3509
static int __meminit first_active_region_index_in_nid(int nid)
3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521
{
	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
3522
 * Note: nid == MAX_NUMNODES returns next region regardless of node
3523
 */
3524
static int __meminit next_active_region_index_in_nid(int index, int nid)
3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539
{
	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
 */
3540
int __meminit __early_pfn_to_nid(unsigned long pfn)
3541 3542 3543 3544 3545 3546 3547 3548 3549 3550
{
	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;
	}
3551 3552
	/* This is a memory hole */
	return -1;
3553 3554 3555
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

3556 3557
int __meminit early_pfn_to_nid(unsigned long pfn)
{
3558 3559 3560 3561 3562 3563 3564
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0)
		return nid;
	/* just returns 0 */
	return 0;
3565 3566
}

3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577
#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
3578

3579 3580 3581 3582 3583 3584 3585
/* 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
3586 3587
 * @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
3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614
 *
 * 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);
	}
}

3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629
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;
}

3630
#ifdef CONFIG_NO_BOOTMEM
3631 3632 3633 3634 3635 3636
void * __init __alloc_memory_core_early(int nid, u64 size, u64 align,
					u64 goal, u64 limit)
{
	int i;
	void *ptr;

3637 3638 3639
	if (limit > get_max_mapped())
		limit = get_max_mapped();

3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664
	/* 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");
3665 3666 3667 3668 3669
		/*
		 * The min_count is set to 0 so that bootmem allocated blocks
		 * are never reported as leaks.
		 */
		kmemleak_alloc(ptr, size, 0, 0);
3670 3671 3672 3673 3674
		return ptr;
	}

	return NULL;
}
3675
#endif
3676 3677


3678 3679 3680
void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
{
	int i;
3681
	int ret;
3682

3683 3684 3685 3686 3687 3688
	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;
	}
3689
}
3690 3691
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3692
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3693 3694 3695
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
3696
 * function may be used instead of calling memory_present() manually.
3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709
 */
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
3710 3711 3712
 * @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.
3713 3714 3715 3716
 *
 * 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
3717
 * PFNs will be 0.
3718
 */
3719
void __meminit get_pfn_range_for_nid(unsigned int nid,
3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730
			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);
	}

3731
	if (*start_pfn == -1UL)
3732 3733 3734
		*start_pfn = 0;
}

M
Mel Gorman 已提交
3735 3736 3737 3738 3739
/*
 * 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
3740
static void __init find_usable_zone_for_movable(void)
M
Mel Gorman 已提交
3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765
{
	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
3766
static void __meminit adjust_zone_range_for_zone_movable(int nid,
M
Mel Gorman 已提交
3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791
					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;
	}
}

3792 3793 3794 3795
/*
 * 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
3796
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3797 3798 3799 3800 3801 3802 3803 3804 3805 3806
					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
3807 3808 3809
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824

	/* 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,
3825
 * then all holes in the requested range will be accounted for.
3826
 */
3827
unsigned long __meminit __absent_pages_in_range(int nid,
3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839
				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;

3840 3841
	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);

3842 3843
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
3844
		hole_pages = prev_end_pfn - range_start_pfn;
3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864

	/* 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;
	}

3865 3866
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
3867
		hole_pages += range_end_pfn -
3868 3869
				max(range_start_pfn, prev_end_pfn);

3870 3871 3872 3873 3874 3875 3876 3877
	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
 *
3878
 * It returns the number of pages frames in memory holes within a range.
3879 3880 3881 3882 3883 3884 3885 3886
 */
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
3887
static unsigned long __meminit zone_absent_pages_in_node(int nid,
3888 3889 3890
					unsigned long zone_type,
					unsigned long *ignored)
{
3891 3892 3893 3894 3895 3896 3897 3898 3899
	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
3900 3901 3902
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
3903
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3904
}
3905

3906
#else
P
Paul Mundt 已提交
3907
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3908 3909 3910 3911 3912 3913
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
3914
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3915 3916 3917 3918 3919 3920 3921 3922
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
3923

3924 3925
#endif

3926
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946
		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);
}

3947 3948 3949
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
3950 3951
 * 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
3952 3953 3954 3955 3956 3957 3958
 * 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;

3959 3960
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971
	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;
3972
	if (usemapsize)
3973 3974 3975 3976 3977 3978 3979
		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 */

3980
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3981 3982 3983 3984 3985 3986 3987 3988 3989 3990

/* 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;
}

3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005
/* 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 */

4006 4007 4008 4009 4010 4011 4012 4013 4014 4015
/*
 * 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;
}
4016 4017 4018 4019
#define set_pageblock_order(x)	do {} while (0)

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
4020 4021 4022 4023 4024 4025
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
4026
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
4027 4028
		unsigned long *zones_size, unsigned long *zholes_size)
{
4029
	enum zone_type j;
4030
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
4031
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
4032
	int ret;
L
Linus Torvalds 已提交
4033

4034
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
4035 4036 4037
	pgdat->nr_zones = 0;
	init_waitqueue_head(&pgdat->kswapd_wait);
	pgdat->kswapd_max_order = 0;
4038
	pgdat_page_cgroup_init(pgdat);
L
Linus Torvalds 已提交
4039 4040 4041
	
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
4042
		unsigned long size, realsize, memmap_pages;
4043
		enum lru_list l;
L
Linus Torvalds 已提交
4044

4045 4046 4047
		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
4048

4049 4050 4051 4052 4053
		/*
		 * 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
		 */
4054 4055
		memmap_pages =
			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
4056 4057
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
4058 4059 4060 4061
			if (memmap_pages)
				printk(KERN_DEBUG
				       "  %s zone: %lu pages used for memmap\n",
				       zone_names[j], memmap_pages);
4062 4063 4064 4065 4066
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

4067 4068
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
4069
			realsize -= dma_reserve;
Y
Yinghai Lu 已提交
4070
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
4071
					zone_names[0], dma_reserve);
4072 4073
		}

4074
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
4075 4076 4077 4078 4079
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
4080
#ifdef CONFIG_NUMA
4081
		zone->node = nid;
4082
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
4083
						/ 100;
4084
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
4085
#endif
L
Linus Torvalds 已提交
4086 4087 4088
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
4089
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
4090 4091
		zone->zone_pgdat = pgdat;

4092
		zone->prev_priority = DEF_PRIORITY;
L
Linus Torvalds 已提交
4093

4094
		zone_pcp_init(zone);
4095 4096
		for_each_lru(l) {
			INIT_LIST_HEAD(&zone->lru[l].list);
4097
			zone->reclaim_stat.nr_saved_scan[l] = 0;
4098
		}
4099 4100 4101 4102
		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;
4103
		zap_zone_vm_stats(zone);
4104
		zone->flags = 0;
L
Linus Torvalds 已提交
4105 4106 4107
		if (!size)
			continue;

4108
		set_pageblock_order(pageblock_default_order());
4109
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
4110 4111
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
4112
		BUG_ON(ret);
4113
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
4114 4115 4116 4117
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
4118
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
4119 4120 4121 4122 4123
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
4124
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
4125 4126
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
4127
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
4128 4129
		struct page *map;

4130 4131 4132 4133 4134 4135 4136 4137 4138
		/*
		 * 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);
4139 4140 4141
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
4142
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
4143
	}
4144
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
4145 4146 4147
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
4148
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
4149
		mem_map = NODE_DATA(0)->node_mem_map;
4150 4151
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4152
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
4153 4154
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
4155
#endif
A
Andy Whitcroft 已提交
4156
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
4157 4158
}

4159 4160
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
4161
{
4162 4163
	pg_data_t *pgdat = NODE_DATA(nid);

L
Linus Torvalds 已提交
4164 4165
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
4166
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
4167 4168

	alloc_node_mem_map(pgdat);
4169 4170 4171 4172 4173
#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
4174 4175 4176 4177

	free_area_init_core(pgdat, zones_size, zholes_size);
}

4178
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
M
Miklos Szeredi 已提交
4179 4180 4181 4182 4183 4184 4185 4186 4187 4188 4189 4190 4191 4192 4193 4194 4195 4196 4197 4198

#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

4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215
/**
 * 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;

4216 4217 4218 4219 4220
	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);
4221

4222 4223
	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);

4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241
	/* 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 */
4242
		if (start_pfn < early_node_map[i].start_pfn &&
4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262
				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;
}

/**
4263
 * remove_active_range - Shrink an existing registered range of PFNs
4264
 * @nid: The node id the range is on that should be shrunk
4265 4266
 * @start_pfn: The new PFN of the range
 * @end_pfn: The new PFN of the range
4267 4268
 *
 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
4269 4270 4271
 * 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.
4272
 */
4273 4274
void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
				unsigned long end_pfn)
4275
{
4276 4277
	int i, j;
	int removed = 0;
4278

4279 4280 4281
	printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
			  nid, start_pfn, end_pfn);

4282
	/* Find the old active region end and shrink */
4283
	for_each_active_range_index_in_nid(i, nid) {
4284 4285
		if (early_node_map[i].start_pfn >= start_pfn &&
		    early_node_map[i].end_pfn <= end_pfn) {
4286
			/* clear it */
4287
			early_node_map[i].start_pfn = 0;
4288 4289 4290 4291
			early_node_map[i].end_pfn = 0;
			removed = 1;
			continue;
		}
4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302 4303
		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;
4304
			continue;
4305
		}
4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323 4324
	}

	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--;
	}
4325 4326 4327 4328
}

/**
 * remove_all_active_ranges - Remove all currently registered regions
4329
 *
4330 4331 4332 4333
 * 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.
 */
4334
void __init remove_all_active_ranges(void)
4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352 4353 4354 4355
{
	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 */
4356
void __init sort_node_map(void)
4357 4358 4359 4360 4361 4362
{
	sort(early_node_map, (size_t)nr_nodemap_entries,
			sizeof(struct node_active_region),
			cmp_node_active_region, NULL);
}

4363
/* Find the lowest pfn for a node */
A
Adrian Bunk 已提交
4364
static unsigned long __init find_min_pfn_for_node(int nid)
4365 4366
{
	int i;
4367
	unsigned long min_pfn = ULONG_MAX;
4368

4369 4370
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
4371
		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
4372

4373 4374
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
4375
			"Could not find start_pfn for node %d\n", nid);
4376 4377 4378 4379
		return 0;
	}

	return min_pfn;
4380 4381 4382 4383 4384 4385
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
4386
 * add_active_range().
4387 4388 4389 4390 4391 4392
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

4393 4394 4395 4396 4397
/*
 * 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
4398
static unsigned long __init early_calculate_totalpages(void)
4399 4400 4401 4402
{
	int i;
	unsigned long totalpages = 0;

4403 4404
	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long pages = early_node_map[i].end_pfn -
4405
						early_node_map[i].start_pfn;
4406 4407 4408 4409 4410
		totalpages += pages;
		if (pages)
			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
	}
  	return totalpages;
4411 4412
}

M
Mel Gorman 已提交
4413 4414 4415 4416 4417 4418
/*
 * 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
4419
static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
M
Mel Gorman 已提交
4420 4421 4422 4423
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
4424 4425
	/* save the state before borrow the nodemask */
	nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4426 4427
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
4428

4429 4430 4431 4432 4433 4434 4435 4436 4437 4438 4439 4440 4441 4442 4443 4444 4445 4446 4447 4448 4449 4450
	/*
	 * 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
4451 4452
	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
	if (!required_kernelcore)
4453
		goto out;
M
Mel Gorman 已提交
4454 4455 4456 4457 4458 4459 4460 4461

	/* 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;
4462
	for_each_node_state(nid, N_HIGH_MEMORY) {
M
Mel Gorman 已提交
4463 4464 4465 4466 4467 4468 4469 4470 4471 4472 4473 4474 4475 4476 4477 4478 4479 4480 4481 4482 4483 4484 4485 4486 4487 4488 4489 4490 4491 4492 4493 4494 4495 4496 4497 4498 4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516 4517 4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543 4544 4545 4546 4547 4548 4549 4550 4551
		/*
		 * 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);
4552 4553 4554 4555

out:
	/* restore the node_state */
	node_states[N_HIGH_MEMORY] = saved_node_state;
M
Mel Gorman 已提交
4556 4557
}

4558 4559 4560 4561 4562 4563 4564 4565 4566 4567 4568 4569 4570 4571
/* 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
}

4572 4573
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
4574
 * @max_zone_pfn: an array of max PFNs for each zone
4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586 4587
 *
 * 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;
4588
	int i;
4589

4590 4591 4592
	/* Sort early_node_map as initialisation assumes it is sorted */
	sort_node_map();

4593 4594 4595 4596 4597 4598 4599 4600
	/* 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
4601 4602
		if (i == ZONE_MOVABLE)
			continue;
4603 4604 4605 4606 4607
		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
4608 4609 4610 4611 4612 4613
	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);
4614 4615 4616

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
M
Mel Gorman 已提交
4617 4618 4619
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
4620 4621 4622 4623 4624 4625
		printk("  %-8s ", zone_names[i]);
		if (arch_zone_lowest_possible_pfn[i] ==
				arch_zone_highest_possible_pfn[i])
			printk("empty\n");
		else
			printk("%0#10lx -> %0#10lx\n",
4626 4627
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);
M
Mel Gorman 已提交
4628 4629 4630 4631 4632 4633 4634 4635
	}

	/* 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]);
	}
4636 4637 4638 4639

	/* 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++)
4640
		printk("  %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4641 4642 4643 4644
						early_node_map[i].start_pfn,
						early_node_map[i].end_pfn);

	/* Initialise every node */
4645
	mminit_verify_pageflags_layout();
4646
	setup_nr_node_ids();
4647 4648
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
4649
		free_area_init_node(nid, NULL,
4650
				find_min_pfn_for_node(nid), NULL);
4651 4652 4653 4654 4655

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
4656 4657
	}
}
M
Mel Gorman 已提交
4658

4659
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
4660 4661 4662 4663 4664 4665
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
4666
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
4667

4668
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
4669 4670 4671 4672
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
4673

4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689 4690 4691
/*
 * 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
4692
early_param("kernelcore", cmdline_parse_kernelcore);
4693
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
4694

4695 4696
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

4697
/**
4698 4699
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
4700 4701 4702 4703
 *
 * 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
4704 4705 4706
 * 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.
4707 4708 4709 4710 4711 4712
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

4713
#ifndef CONFIG_NEED_MULTIPLE_NODES
4714 4715 4716 4717 4718
struct pglist_data __refdata contig_page_data = {
#ifndef CONFIG_NO_BOOTMEM
 .bdata = &bootmem_node_data[0]
#endif
 };
L
Linus Torvalds 已提交
4719
EXPORT_SYMBOL(contig_page_data);
4720
#endif
L
Linus Torvalds 已提交
4721 4722 4723

void __init free_area_init(unsigned long *zones_size)
{
4724
	free_area_init_node(0, zones_size,
L
Linus Torvalds 已提交
4725 4726 4727 4728 4729 4730 4731 4732
			__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;

4733
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4734 4735 4736 4737 4738 4739 4740 4741
		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.
		 */
4742
		vm_events_fold_cpu(cpu);
4743 4744 4745 4746 4747 4748 4749 4750

		/*
		 * 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.
		 */
4751
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
4752 4753 4754 4755 4756 4757 4758 4759 4760
	}
	return NOTIFY_OK;
}

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

4761 4762 4763 4764 4765 4766 4767 4768
/*
 * 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;
4769
	enum zone_type i, j;
4770 4771 4772 4773 4774 4775 4776 4777 4778 4779 4780 4781

	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];
			}

4782 4783
			/* we treat the high watermark as reserved pages. */
			max += high_wmark_pages(zone);
4784 4785 4786 4787 4788 4789 4790 4791 4792

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

L
Linus Torvalds 已提交
4793 4794 4795 4796 4797 4798 4799 4800 4801
/*
 * 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;
4802
	enum zone_type j, idx;
L
Linus Torvalds 已提交
4803

4804
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
4805 4806 4807 4808 4809 4810
		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;

4811 4812
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
4813 4814
				struct zone *lower_zone;

4815 4816
				idx--;

L
Linus Torvalds 已提交
4817 4818 4819 4820 4821 4822 4823 4824 4825 4826
				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;
			}
		}
	}
4827 4828 4829

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4830 4831
}

4832
/**
4833
 * setup_per_zone_wmarks - called when min_free_kbytes changes
4834
 * or when memory is hot-{added|removed}
4835
 *
4836 4837
 * 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
4838
 */
4839
void setup_per_zone_wmarks(void)
L
Linus Torvalds 已提交
4840 4841 4842 4843 4844 4845 4846 4847 4848 4849 4850 4851 4852
{
	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) {
4853 4854
		u64 tmp;

4855
		spin_lock_irqsave(&zone->lock, flags);
4856 4857
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
4858 4859
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
4860 4861 4862 4863
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
4864
			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
N
Nick Piggin 已提交
4865 4866
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
Linus Torvalds 已提交
4867 4868 4869 4870 4871 4872 4873 4874
			 */
			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;
4875
			zone->watermark[WMARK_MIN] = min_pages;
L
Linus Torvalds 已提交
4876
		} else {
N
Nick Piggin 已提交
4877 4878
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
4879 4880
			 * proportionate to the zone's size.
			 */
4881
			zone->watermark[WMARK_MIN] = tmp;
L
Linus Torvalds 已提交
4882 4883
		}

4884 4885
		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) + (tmp >> 2);
		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
4886
		setup_zone_migrate_reserve(zone);
4887
		spin_unlock_irqrestore(&zone->lock, flags);
L
Linus Torvalds 已提交
4888
	}
4889 4890 4891

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4892 4893
}

4894
/*
4895 4896 4897 4898 4899 4900 4901 4902 4903 4904 4905 4906 4907 4908 4909 4910 4911 4912 4913 4914
 * 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
 */
4915
void calculate_zone_inactive_ratio(struct zone *zone)
4916
{
4917
	unsigned int gb, ratio;
4918

4919 4920 4921
	/* Zone size in gigabytes */
	gb = zone->present_pages >> (30 - PAGE_SHIFT);
	if (gb)
4922
		ratio = int_sqrt(10 * gb);
4923 4924
	else
		ratio = 1;
4925

4926 4927
	zone->inactive_ratio = ratio;
}
4928

4929 4930 4931 4932 4933 4934
static void __init setup_per_zone_inactive_ratio(void)
{
	struct zone *zone;

	for_each_zone(zone)
		calculate_zone_inactive_ratio(zone);
4935 4936
}

L
Linus Torvalds 已提交
4937 4938 4939 4940 4941 4942 4943 4944 4945 4946 4947 4948 4949 4950 4951 4952 4953 4954 4955 4956 4957 4958 4959 4960
/*
 * 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
 */
4961
static int __init init_per_zone_wmark_min(void)
L
Linus Torvalds 已提交
4962 4963 4964 4965 4966 4967 4968 4969 4970 4971
{
	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;
4972
	setup_per_zone_wmarks();
L
Linus Torvalds 已提交
4973
	setup_per_zone_lowmem_reserve();
4974
	setup_per_zone_inactive_ratio();
L
Linus Torvalds 已提交
4975 4976
	return 0;
}
4977
module_init(init_per_zone_wmark_min)
L
Linus Torvalds 已提交
4978 4979 4980 4981 4982 4983 4984

/*
 * 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, 
4985
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
4986
{
4987
	proc_dointvec(table, write, buffer, length, ppos);
4988
	if (write)
4989
		setup_per_zone_wmarks();
L
Linus Torvalds 已提交
4990 4991 4992
	return 0;
}

4993 4994
#ifdef CONFIG_NUMA
int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
4995
	void __user *buffer, size_t *length, loff_t *ppos)
4996 4997 4998 4999
{
	struct zone *zone;
	int rc;

5000
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5001 5002 5003 5004
	if (rc)
		return rc;

	for_each_zone(zone)
5005
		zone->min_unmapped_pages = (zone->present_pages *
5006 5007 5008
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
5009 5010

int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
5011
	void __user *buffer, size_t *length, loff_t *ppos)
5012 5013 5014 5015
{
	struct zone *zone;
	int rc;

5016
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5017 5018 5019 5020 5021 5022 5023 5024
	if (rc)
		return rc;

	for_each_zone(zone)
		zone->min_slab_pages = (zone->present_pages *
				sysctl_min_slab_ratio) / 100;
	return 0;
}
5025 5026
#endif

L
Linus Torvalds 已提交
5027 5028 5029 5030 5031 5032
/*
 * 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
5033
 * minimum watermarks. The lowmem reserve ratio can only make sense
L
Linus Torvalds 已提交
5034 5035 5036
 * if in function of the boot time zone sizes.
 */
int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
5037
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
5038
{
5039
	proc_dointvec_minmax(table, write, buffer, length, ppos);
L
Linus Torvalds 已提交
5040 5041 5042 5043
	setup_per_zone_lowmem_reserve();
	return 0;
}

5044 5045 5046 5047 5048 5049 5050
/*
 * 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,
5051
	void __user *buffer, size_t *length, loff_t *ppos)
5052 5053 5054 5055 5056
{
	struct zone *zone;
	unsigned int cpu;
	int ret;

5057
	ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5058 5059
	if (!write || (ret == -EINVAL))
		return ret;
5060
	for_each_populated_zone(zone) {
5061
		for_each_possible_cpu(cpu) {
5062 5063
			unsigned long  high;
			high = zone->present_pages / percpu_pagelist_fraction;
5064 5065
			setup_pagelist_highmark(
				per_cpu_ptr(zone->pageset, cpu), high);
5066 5067 5068 5069 5070
		}
	}
	return 0;
}

5071
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
5072 5073 5074 5075 5076 5077 5078 5079 5080 5081 5082 5083 5084 5085 5086 5087 5088 5089 5090 5091 5092 5093 5094 5095 5096 5097 5098 5099 5100 5101 5102 5103 5104 5105

#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
5106
		numentries = nr_kernel_pages;
L
Linus Torvalds 已提交
5107 5108 5109 5110 5111 5112 5113 5114 5115
		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);
5116 5117

		/* Make sure we've got at least a 0-order allocation.. */
5118 5119 5120 5121 5122 5123 5124 5125
		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))
5126
			numentries = PAGE_SIZE / bucketsize;
L
Linus Torvalds 已提交
5127
	}
5128
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
5129 5130 5131 5132 5133 5134 5135 5136 5137 5138

	/* 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;

5139
	log2qty = ilog2(numentries);
L
Linus Torvalds 已提交
5140 5141 5142 5143

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
5144
			table = alloc_bootmem_nopanic(size);
L
Linus Torvalds 已提交
5145 5146 5147
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
5148 5149
			/*
			 * If bucketsize is not a power-of-two, we may free
5150 5151
			 * some pages at the end of hash table which
			 * alloc_pages_exact() automatically does
5152
			 */
5153
			if (get_order(size) < MAX_ORDER) {
5154
				table = alloc_pages_exact(size, GFP_ATOMIC);
5155 5156
				kmemleak_alloc(table, size, 1, GFP_ATOMIC);
			}
L
Linus Torvalds 已提交
5157 5158 5159 5160 5161 5162
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

5163
	printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
L
Linus Torvalds 已提交
5164 5165
	       tablename,
	       (1U << log2qty),
5166
	       ilog2(size) - PAGE_SHIFT,
L
Linus Torvalds 已提交
5167 5168 5169 5170 5171 5172 5173 5174 5175
	       size);

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

	return table;
}
5176

5177 5178 5179 5180 5181 5182 5183 5184 5185 5186 5187 5188 5189 5190 5191
/* 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);
5192
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5193 5194
#else
	pfn = pfn - zone->zone_start_pfn;
5195
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5196 5197 5198 5199
#endif /* CONFIG_SPARSEMEM */
}

/**
5200
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5201 5202 5203 5204 5205 5206 5207 5208 5209 5210 5211 5212 5213 5214 5215 5216 5217 5218 5219 5220 5221 5222
 * @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;
5223

5224 5225 5226 5227
	return flags;
}

/**
5228
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5229 5230 5231 5232 5233 5234 5235 5236 5237 5238 5239 5240 5241 5242 5243 5244 5245
 * @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);
5246 5247
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
5248 5249 5250 5251 5252 5253 5254

	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
5255 5256 5257 5258 5259 5260 5261 5262 5263 5264

/*
 * 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;
5265 5266 5267 5268 5269
	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
5270
	int ret = -EBUSY;
5271
	int zone_idx;
K
KAMEZAWA Hiroyuki 已提交
5272 5273

	zone = page_zone(page);
5274
	zone_idx = zone_idx(zone);
5275

K
KAMEZAWA Hiroyuki 已提交
5276
	spin_lock_irqsave(&zone->lock, flags);
5277 5278 5279 5280 5281 5282 5283 5284 5285 5286 5287
	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
5288
	/*
5289 5290 5291 5292 5293 5294 5295 5296 5297
	 * 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
5298
	 */
5299 5300 5301
	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
5302
		goto out;
5303 5304 5305 5306 5307 5308 5309 5310 5311 5312 5313 5314 5315 5316 5317

	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
5318
out:
5319 5320 5321 5322 5323
	if (!ret) {
		set_pageblock_migratetype(page, MIGRATE_ISOLATE);
		move_freepages_block(zone, page, MIGRATE_ISOLATE);
	}

K
KAMEZAWA Hiroyuki 已提交
5324 5325
	spin_unlock_irqrestore(&zone->lock, flags);
	if (!ret)
5326
		drain_all_pages();
K
KAMEZAWA Hiroyuki 已提交
5327 5328 5329 5330 5331 5332 5333 5334 5335 5336 5337 5338 5339 5340 5341 5342
	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
5343 5344 5345 5346 5347 5348 5349 5350 5351 5352 5353 5354 5355 5356 5357 5358 5359 5360 5361 5362 5363 5364 5365 5366 5367 5368 5369 5370 5371 5372 5373 5374 5375 5376 5377 5378 5379 5380 5381 5382 5383 5384 5385 5386 5387 5388 5389

#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
5390 5391 5392 5393 5394 5395 5396 5397 5398 5399 5400 5401 5402 5403 5404 5405 5406 5407 5408 5409 5410

#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
5411 5412 5413 5414 5415 5416 5417 5418 5419 5420 5421 5422 5423 5424 5425 5426 5427 5428 5429 5430 5431 5432 5433 5434 5435 5436 5437 5438 5439 5440 5441 5442 5443 5444 5445 5446 5447 5448 5449 5450 5451 5452 5453 5454 5455 5456 5457 5458 5459 5460 5461 5462 5463 5464 5465 5466 5467 5468 5469 5470 5471 5472 5473 5474 5475 5476 5477 5478 5479 5480 5481 5482 5483 5484 5485 5486 5487

static struct trace_print_flags pageflag_names[] = {
	{1UL << PG_locked,		"locked"	},
	{1UL << PG_error,		"error"		},
	{1UL << PG_referenced,		"referenced"	},
	{1UL << PG_uptodate,		"uptodate"	},
	{1UL << PG_dirty,		"dirty"		},
	{1UL << PG_lru,			"lru"		},
	{1UL << PG_active,		"active"	},
	{1UL << PG_slab,		"slab"		},
	{1UL << PG_owner_priv_1,	"owner_priv_1"	},
	{1UL << PG_arch_1,		"arch_1"	},
	{1UL << PG_reserved,		"reserved"	},
	{1UL << PG_private,		"private"	},
	{1UL << PG_private_2,		"private_2"	},
	{1UL << PG_writeback,		"writeback"	},
#ifdef CONFIG_PAGEFLAGS_EXTENDED
	{1UL << PG_head,		"head"		},
	{1UL << PG_tail,		"tail"		},
#else
	{1UL << PG_compound,		"compound"	},
#endif
	{1UL << PG_swapcache,		"swapcache"	},
	{1UL << PG_mappedtodisk,	"mappedtodisk"	},
	{1UL << PG_reclaim,		"reclaim"	},
	{1UL << PG_buddy,		"buddy"		},
	{1UL << PG_swapbacked,		"swapbacked"	},
	{1UL << PG_unevictable,		"unevictable"	},
#ifdef CONFIG_MMU
	{1UL << PG_mlocked,		"mlocked"	},
#endif
#ifdef CONFIG_ARCH_USES_PG_UNCACHED
	{1UL << PG_uncached,		"uncached"	},
#endif
#ifdef CONFIG_MEMORY_FAILURE
	{1UL << PG_hwpoison,		"hwpoison"	},
#endif
	{-1UL,				NULL		},
};

static void dump_page_flags(unsigned long flags)
{
	const char *delim = "";
	unsigned long mask;
	int i;

	printk(KERN_ALERT "page flags: %#lx(", flags);

	/* remove zone id */
	flags &= (1UL << NR_PAGEFLAGS) - 1;

	for (i = 0; pageflag_names[i].name && flags; i++) {

		mask = pageflag_names[i].mask;
		if ((flags & mask) != mask)
			continue;

		flags &= ~mask;
		printk("%s%s", delim, pageflag_names[i].name);
		delim = "|";
	}

	/* check for left over flags */
	if (flags)
		printk("%s%#lx", delim, flags);

	printk(")\n");
}

void dump_page(struct page *page)
{
	printk(KERN_ALERT
	       "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
		page, page_count(page), page_mapcount(page),
		page->mapping, page->index);
	dump_page_flags(page->flags);
}