page_alloc.c 155.9 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>
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#include <linux/memblock.h>
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#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).
 */
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static gfp_t saved_gfp_mask;

void pm_restore_gfp_mask(void)
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{
	WARN_ON(!mutex_is_locked(&pm_mutex));
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	if (saved_gfp_mask) {
		gfp_allowed_mask = saved_gfp_mask;
		saved_gfp_mask = 0;
	}
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}

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void pm_restrict_gfp_mask(void)
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{
	WARN_ON(!mutex_is_locked(&pm_mutex));
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	WARN_ON(saved_gfp_mask);
	saved_gfp_mask = gfp_allowed_mask;
	gfp_allowed_mask &= ~GFP_IOFS;
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}
#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)) {
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		reset_page_mapcount(page); /* remove PageBuddy */
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		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 */
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	reset_page_mapcount(page); /* remove PageBuddy */
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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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/* update __split_huge_page_refcount if you change this function */
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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 unsigned long
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__find_buddy_index(unsigned long page_idx, unsigned int order)
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{
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	return page_idx ^ (1 << order);
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}

/*
 * 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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 *
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 * For recording whether a page is in the buddy system, we set ->_mapcount -2.
 * Setting, clearing, and testing _mapcount -2 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 _mapcount -2. 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;
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	unsigned long uninitialized_var(buddy_idx);
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	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) {
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		buddy_idx = __find_buddy_index(page_idx, order);
		buddy = page + (buddy_idx - page_idx);
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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 = buddy_idx & page_idx;
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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
	 */
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	if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
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		struct page *higher_page, *higher_buddy;
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		combined_idx = buddy_idx & page_idx;
		higher_page = page + (combined_idx - page_idx);
		buddy_idx = __find_buddy_index(combined_idx, order + 1);
		higher_buddy = page + (buddy_idx - combined_idx);
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		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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549 550 551
	zone->free_area[order].nr_free++;
}

552 553 554 555 556 557 558 559 560 561 562
/*
 * 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);
}

N
Nick Piggin 已提交
563
static inline int free_pages_check(struct page *page)
L
Linus Torvalds 已提交
564
{
N
Nick Piggin 已提交
565 566
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
567
		(atomic_read(&page->_count) != 0) |
568
		(page->flags & PAGE_FLAGS_CHECK_AT_FREE))) {
N
Nick Piggin 已提交
569
		bad_page(page);
570
		return 1;
571
	}
572 573 574
	if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
		page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
	return 0;
L
Linus Torvalds 已提交
575 576 577
}

/*
578
 * Frees a number of pages from the PCP lists
L
Linus Torvalds 已提交
579
 * Assumes all pages on list are in same zone, and of same order.
580
 * count is the number of pages to free.
L
Linus Torvalds 已提交
581 582 583 584 585 586 587
 *
 * 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.
 */
588 589
static void free_pcppages_bulk(struct zone *zone, int count,
					struct per_cpu_pages *pcp)
L
Linus Torvalds 已提交
590
{
591
	int migratetype = 0;
592
	int batch_free = 0;
593
	int to_free = count;
594

N
Nick Piggin 已提交
595
	spin_lock(&zone->lock);
596
	zone->all_unreclaimable = 0;
L
Linus Torvalds 已提交
597
	zone->pages_scanned = 0;
598

599
	while (to_free) {
N
Nick Piggin 已提交
600
		struct page *page;
601 602 603
		struct list_head *list;

		/*
604 605 606 607 608
		 * 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
609 610
		 */
		do {
611
			batch_free++;
612 613 614 615
			if (++migratetype == MIGRATE_PCPTYPES)
				migratetype = 0;
			list = &pcp->lists[migratetype];
		} while (list_empty(list));
N
Nick Piggin 已提交
616

617 618 619 620
		do {
			page = list_entry(list->prev, struct page, lru);
			/* must delete as __free_one_page list manipulates */
			list_del(&page->lru);
621 622 623
			/* 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));
624
		} while (--to_free && --batch_free && !list_empty(list));
L
Linus Torvalds 已提交
625
	}
626
	__mod_zone_page_state(zone, NR_FREE_PAGES, count);
N
Nick Piggin 已提交
627
	spin_unlock(&zone->lock);
L
Linus Torvalds 已提交
628 629
}

630 631
static void free_one_page(struct zone *zone, struct page *page, int order,
				int migratetype)
L
Linus Torvalds 已提交
632
{
633
	spin_lock(&zone->lock);
634
	zone->all_unreclaimable = 0;
635
	zone->pages_scanned = 0;
636

637
	__free_one_page(page, zone, order, migratetype);
638
	__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
639
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
640 641
}

642
static bool free_pages_prepare(struct page *page, unsigned int order)
N
Nick Piggin 已提交
643
{
L
Linus Torvalds 已提交
644
	int i;
645
	int bad = 0;
L
Linus Torvalds 已提交
646

647
	trace_mm_page_free_direct(page, order);
648 649
	kmemcheck_free_shadow(page, order);

A
Andrea Arcangeli 已提交
650 651 652 653
	if (PageAnon(page))
		page->mapping = NULL;
	for (i = 0; i < (1 << order); i++)
		bad += free_pages_check(page + i);
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 1092 1093 1094
		if (pcp->count) {
			free_pcppages_bulk(zone, pcp->count, pcp);
			pcp->count = 0;
		}
1095
		local_irq_restore(flags);
L
Linus Torvalds 已提交
1096 1097 1098
	}
}

1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111
/*
 * 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)
{
1112
	on_each_cpu(drain_local_pages, NULL, 1);
1113 1114
}

1115
#ifdef CONFIG_HIBERNATION
L
Linus Torvalds 已提交
1116 1117 1118

void mark_free_pages(struct zone *zone)
{
1119 1120
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
1121
	int order, t;
L
Linus Torvalds 已提交
1122 1123 1124 1125 1126 1127
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
1128 1129 1130 1131 1132 1133

	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);

1134 1135
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
1136
		}
L
Linus Torvalds 已提交
1137

1138 1139
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
1140
			unsigned long i;
L
Linus Torvalds 已提交
1141

1142 1143
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
1144
				swsusp_set_page_free(pfn_to_page(pfn + i));
1145
		}
1146
	}
L
Linus Torvalds 已提交
1147 1148
	spin_unlock_irqrestore(&zone->lock, flags);
}
1149
#endif /* CONFIG_PM */
L
Linus Torvalds 已提交
1150 1151 1152

/*
 * Free a 0-order page
L
Li Hong 已提交
1153
 * cold == 1 ? free a cold page : free a hot page
L
Linus Torvalds 已提交
1154
 */
L
Li Hong 已提交
1155
void free_hot_cold_page(struct page *page, int cold)
L
Linus Torvalds 已提交
1156 1157 1158 1159
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;
1160
	int migratetype;
1161
	int wasMlocked = __TestClearPageMlocked(page);
L
Linus Torvalds 已提交
1162

1163
	if (!free_pages_prepare(page, 0))
1164 1165
		return;

1166 1167
	migratetype = get_pageblock_migratetype(page);
	set_page_private(page, migratetype);
L
Linus Torvalds 已提交
1168
	local_irq_save(flags);
1169
	if (unlikely(wasMlocked))
1170
		free_page_mlock(page);
1171
	__count_vm_event(PGFREE);
1172

1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187
	/*
	 * 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;
	}

1188
	pcp = &this_cpu_ptr(zone->pageset)->pcp;
1189
	if (cold)
1190
		list_add_tail(&page->lru, &pcp->lists[migratetype]);
1191
	else
1192
		list_add(&page->lru, &pcp->lists[migratetype]);
L
Linus Torvalds 已提交
1193
	pcp->count++;
N
Nick Piggin 已提交
1194
	if (pcp->count >= pcp->high) {
1195
		free_pcppages_bulk(zone, pcp->batch, pcp);
N
Nick Piggin 已提交
1196 1197
		pcp->count -= pcp->batch;
	}
1198 1199

out:
L
Linus Torvalds 已提交
1200 1201 1202
	local_irq_restore(flags);
}

N
Nick Piggin 已提交
1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214
/*
 * 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
1215 1216
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1217 1218 1219 1220 1221 1222 1223 1224 1225 1226

#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

1227 1228
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
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 1274 1275
/*
 * 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
1276 1277 1278 1279 1280
/*
 * 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.
 */
1281 1282
static inline
struct page *buffered_rmqueue(struct zone *preferred_zone,
1283 1284
			struct zone *zone, int order, gfp_t gfp_flags,
			int migratetype)
L
Linus Torvalds 已提交
1285 1286
{
	unsigned long flags;
1287
	struct page *page;
L
Linus Torvalds 已提交
1288 1289
	int cold = !!(gfp_flags & __GFP_COLD);

1290
again:
N
Nick Piggin 已提交
1291
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1292
		struct per_cpu_pages *pcp;
1293
		struct list_head *list;
L
Linus Torvalds 已提交
1294 1295

		local_irq_save(flags);
1296 1297
		pcp = &this_cpu_ptr(zone->pageset)->pcp;
		list = &pcp->lists[migratetype];
1298
		if (list_empty(list)) {
1299
			pcp->count += rmqueue_bulk(zone, 0,
1300
					pcp->batch, list,
1301
					migratetype, cold);
1302
			if (unlikely(list_empty(list)))
1303
				goto failed;
1304
		}
1305

1306 1307 1308 1309 1310
		if (cold)
			page = list_entry(list->prev, struct page, lru);
		else
			page = list_entry(list->next, struct page, lru);

1311 1312
		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1313
	} else {
1314 1315 1316 1317 1318 1319 1320 1321
		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
1322
			 * allocate greater than order-1 page units with
1323 1324
			 * __GFP_NOFAIL.
			 */
1325
			WARN_ON_ONCE(order > 1);
1326
		}
L
Linus Torvalds 已提交
1327
		spin_lock_irqsave(&zone->lock, flags);
1328
		page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1329 1330 1331
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
1332
		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
L
Linus Torvalds 已提交
1333 1334
	}

1335
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1336
	zone_statistics(preferred_zone, zone);
N
Nick Piggin 已提交
1337
	local_irq_restore(flags);
L
Linus Torvalds 已提交
1338

N
Nick Piggin 已提交
1339
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1340
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1341
		goto again;
L
Linus Torvalds 已提交
1342
	return page;
N
Nick Piggin 已提交
1343 1344 1345 1346

failed:
	local_irq_restore(flags);
	return NULL;
L
Linus Torvalds 已提交
1347 1348
}

1349 1350 1351 1352 1353 1354 1355 1356 1357
/* 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)

1358 1359 1360
#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
1361

1362 1363 1364 1365 1366 1367 1368
#ifdef CONFIG_FAIL_PAGE_ALLOC

static struct fail_page_alloc_attr {
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1369
	u32 min_order;
1370 1371 1372 1373 1374

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

	struct dentry *ignore_gfp_highmem_file;
	struct dentry *ignore_gfp_wait_file;
1375
	struct dentry *min_order_file;
1376 1377 1378 1379 1380

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1381 1382
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1383
	.min_order = 1,
1384 1385 1386 1387 1388 1389 1390 1391 1392 1393
};

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)
{
1394 1395
	if (order < fail_page_alloc.min_order)
		return 0;
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 1425 1426
	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);
1427 1428 1429
	fail_page_alloc.min_order_file =
		debugfs_create_u32("min-order", mode, dir,
				   &fail_page_alloc.min_order);
1430 1431

	if (!fail_page_alloc.ignore_gfp_wait_file ||
1432 1433
            !fail_page_alloc.ignore_gfp_highmem_file ||
            !fail_page_alloc.min_order_file) {
1434 1435 1436
		err = -ENOMEM;
		debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
		debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1437
		debugfs_remove(fail_page_alloc.min_order_file);
1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456
		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
1457
/*
1458
 * Return true if free pages are above 'mark'. This takes into account the order
L
Linus Torvalds 已提交
1459 1460
 * of the allocation.
 */
1461 1462
static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
		      int classzone_idx, int alloc_flags, long free_pages)
L
Linus Torvalds 已提交
1463 1464
{
	/* free_pages my go negative - that's OK */
1465
	long min = mark;
L
Linus Torvalds 已提交
1466 1467
	int o;

1468
	free_pages -= (1 << order) + 1;
R
Rohit Seth 已提交
1469
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1470
		min -= min / 2;
R
Rohit Seth 已提交
1471
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1472 1473 1474
		min -= min / 4;

	if (free_pages <= min + z->lowmem_reserve[classzone_idx])
1475
		return false;
L
Linus Torvalds 已提交
1476 1477 1478 1479 1480 1481 1482 1483
	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)
1484
			return false;
L
Linus Torvalds 已提交
1485
	}
1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505
	return true;
}

bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
		      int classzone_idx, int alloc_flags)
{
	return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
					zone_page_state(z, NR_FREE_PAGES));
}

bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark,
		      int classzone_idx, int alloc_flags)
{
	long free_pages = zone_page_state(z, NR_FREE_PAGES);

	if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
		free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);

	return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
								free_pages);
L
Linus Torvalds 已提交
1506 1507
}

1508 1509 1510 1511 1512 1513
#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
1514
 * that have to skip over a lot of full or unallowed zones.
1515 1516 1517
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1518
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539
 *
 * 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
1540
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1541 1542 1543 1544 1545 1546
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1547
					&node_states[N_HIGH_MEMORY];
1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572
	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.
 */
1573
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1574 1575 1576 1577 1578 1579 1580 1581 1582 1583
						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;

1584
	i = z - zonelist->_zonerefs;
1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595
	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.
 */
1596
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1597 1598 1599 1600 1601 1602 1603 1604
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

1605
	i = z - zonelist->_zonerefs;
1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

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

1617
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1618 1619 1620 1621 1622
				nodemask_t *allowednodes)
{
	return 1;
}

1623
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1624 1625 1626 1627
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1628
/*
1629
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1630 1631 1632
 * a page.
 */
static struct page *
1633
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1634
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1635
		struct zone *preferred_zone, int migratetype)
M
Martin Hicks 已提交
1636
{
1637
	struct zoneref *z;
R
Rohit Seth 已提交
1638
	struct page *page = NULL;
1639
	int classzone_idx;
1640
	struct zone *zone;
1641 1642 1643
	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 */
1644

1645
	classzone_idx = zone_idx(preferred_zone);
1646
zonelist_scan:
R
Rohit Seth 已提交
1647
	/*
1648
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1649 1650
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1651 1652
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1653 1654 1655
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1656
		if ((alloc_flags & ALLOC_CPUSET) &&
1657
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1658
				goto try_next_zone;
R
Rohit Seth 已提交
1659

1660
		BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
R
Rohit Seth 已提交
1661
		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1662
			unsigned long mark;
1663 1664
			int ret;

1665
			mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684
			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))
1685
					goto this_zone_full;
1686
			}
R
Rohit Seth 已提交
1687 1688
		}

1689
try_this_zone:
1690 1691
		page = buffered_rmqueue(preferred_zone, zone, order,
						gfp_mask, migratetype);
1692
		if (page)
R
Rohit Seth 已提交
1693
			break;
1694 1695 1696 1697
this_zone_full:
		if (NUMA_BUILD)
			zlc_mark_zone_full(zonelist, z);
try_next_zone:
1698
		if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1699 1700 1701 1702
			/*
			 * we do zlc_setup after the first zone is tried but only
			 * if there are multiple nodes make it worthwhile
			 */
1703 1704 1705 1706
			allowednodes = zlc_setup(zonelist, alloc_flags);
			zlc_active = 1;
			did_zlc_setup = 1;
		}
1707
	}
1708 1709 1710 1711 1712 1713

	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
1714
	return page;
M
Martin Hicks 已提交
1715 1716
}

1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730
/*
 * Large machines with many possible nodes should not always dump per-node
 * meminfo in irq context.
 */
static inline bool should_suppress_show_mem(void)
{
	bool ret = false;

#if NODES_SHIFT > 8
	ret = in_interrupt();
#endif
	return ret;
}

1731 1732 1733
static inline int
should_alloc_retry(gfp_t gfp_mask, unsigned int order,
				unsigned long pages_reclaimed)
L
Linus Torvalds 已提交
1734
{
1735 1736 1737
	/* Do not loop if specifically requested */
	if (gfp_mask & __GFP_NORETRY)
		return 0;
L
Linus Torvalds 已提交
1738

1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755
	/*
	 * 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;
1756

1757 1758 1759 1760 1761 1762
	/*
	 * 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
1763

1764 1765
	return 0;
}
1766

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

	/* Acquire the OOM killer lock for the zones in zonelist */
1776
	if (!try_set_zonelist_oom(zonelist, gfp_mask)) {
1777
		schedule_timeout_uninterruptible(1);
L
Linus Torvalds 已提交
1778 1779
		return NULL;
	}
1780

1781 1782 1783 1784 1785 1786 1787
	/*
	 * 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,
1788
		ALLOC_WMARK_HIGH|ALLOC_CPUSET,
1789
		preferred_zone, migratetype);
R
Rohit Seth 已提交
1790
	if (page)
1791 1792
		goto out;

1793 1794 1795 1796
	if (!(gfp_mask & __GFP_NOFAIL)) {
		/* The OOM killer will not help higher order allocs */
		if (order > PAGE_ALLOC_COSTLY_ORDER)
			goto out;
1797 1798 1799
		/* The OOM killer does not needlessly kill tasks for lowmem */
		if (high_zoneidx < ZONE_NORMAL)
			goto out;
1800 1801 1802 1803 1804 1805 1806 1807 1808 1809
		/*
		 * 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;
	}
1810
	/* Exhausted what can be done so it's blamo time */
1811
	out_of_memory(zonelist, gfp_mask, order, nodemask);
1812 1813 1814 1815 1816 1817

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

1818 1819 1820 1821 1822 1823
#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,
1824 1825
	int migratetype, unsigned long *did_some_progress,
	bool sync_migration)
1826 1827 1828
{
	struct page *page;

1829
	if (!order || compaction_deferred(preferred_zone))
1830 1831
		return NULL;

1832
	current->flags |= PF_MEMALLOC;
1833
	*did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
1834
						nodemask, sync_migration);
1835
	current->flags &= ~PF_MEMALLOC;
1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846
	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) {
1847 1848
			preferred_zone->compact_considered = 0;
			preferred_zone->compact_defer_shift = 0;
1849 1850 1851 1852 1853 1854 1855 1856 1857 1858
			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);
1859
		defer_compaction(preferred_zone);
1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870

		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,
1871 1872
	int migratetype, unsigned long *did_some_progress,
	bool sync_migration)
1873 1874 1875 1876 1877
{
	return NULL;
}
#endif /* CONFIG_COMPACTION */

1878 1879 1880 1881
/* 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,
1882
	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1883
	int migratetype, unsigned long *did_some_progress)
1884 1885 1886
{
	struct page *page = NULL;
	struct reclaim_state reclaim_state;
1887
	bool drained = false;
1888 1889 1890 1891 1892

	cond_resched();

	/* We now go into synchronous reclaim */
	cpuset_memory_pressure_bump();
1893
	current->flags |= PF_MEMALLOC;
1894 1895
	lockdep_set_current_reclaim_state(gfp_mask);
	reclaim_state.reclaimed_slab = 0;
1896
	current->reclaim_state = &reclaim_state;
1897 1898 1899

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

1900
	current->reclaim_state = NULL;
1901
	lockdep_clear_current_reclaim_state();
1902
	current->flags &= ~PF_MEMALLOC;
1903 1904 1905

	cond_resched();

1906 1907
	if (unlikely(!(*did_some_progress)))
		return NULL;
1908

1909 1910
retry:
	page = get_page_from_freelist(gfp_mask, nodemask, order,
1911
					zonelist, high_zoneidx,
1912 1913
					alloc_flags, preferred_zone,
					migratetype);
1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924

	/*
	 * If an allocation failed after direct reclaim, it could be because
	 * pages are pinned on the per-cpu lists. Drain them and try again
	 */
	if (!page && !drained) {
		drain_all_pages();
		drained = true;
		goto retry;
	}

1925 1926 1927
	return page;
}

L
Linus Torvalds 已提交
1928
/*
1929 1930
 * 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
1931
 */
1932 1933 1934
static inline struct page *
__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1935 1936
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1937 1938 1939 1940 1941
{
	struct page *page;

	do {
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1942
			zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
1943
			preferred_zone, migratetype);
1944 1945

		if (!page && gfp_mask & __GFP_NOFAIL)
1946
			wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
1947 1948 1949 1950 1951 1952 1953
	} while (!page && (gfp_mask & __GFP_NOFAIL));

	return page;
}

static inline
void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
1954 1955
						enum zone_type high_zoneidx,
						enum zone_type classzone_idx)
L
Linus Torvalds 已提交
1956
{
1957 1958
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
1959

1960
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
1961
		wakeup_kswapd(zone, order, classzone_idx);
1962
}
1963

1964 1965 1966 1967 1968
static inline int
gfp_to_alloc_flags(gfp_t gfp_mask)
{
	int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
	const gfp_t wait = gfp_mask & __GFP_WAIT;
L
Linus Torvalds 已提交
1969

1970
	/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
1971
	BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
1972

1973 1974 1975 1976 1977 1978
	/*
	 * 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).
	 */
1979
	alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
L
Linus Torvalds 已提交
1980

1981
	if (!wait) {
1982 1983 1984 1985 1986 1987
		/*
		 * Not worth trying to allocate harder for
		 * __GFP_NOMEMALLOC even if it can't schedule.
		 */
		if  (!(gfp_mask & __GFP_NOMEMALLOC))
			alloc_flags |= ALLOC_HARDER;
1988
		/*
1989 1990
		 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
		 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1991
		 */
1992
		alloc_flags &= ~ALLOC_CPUSET;
1993
	} else if (unlikely(rt_task(current)) && !in_interrupt())
1994 1995 1996 1997
		alloc_flags |= ALLOC_HARDER;

	if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
		if (!in_interrupt() &&
1998
		    ((current->flags & PF_MEMALLOC) ||
1999 2000
		     unlikely(test_thread_flag(TIF_MEMDIE))))
			alloc_flags |= ALLOC_NO_WATERMARKS;
L
Linus Torvalds 已提交
2001
	}
2002

2003 2004 2005
	return alloc_flags;
}

2006 2007 2008
static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
2009 2010
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
2011 2012 2013 2014 2015 2016
{
	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;
2017
	bool sync_migration = false;
L
Linus Torvalds 已提交
2018

2019 2020 2021 2022 2023 2024
	/*
	 * 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.
	 */
2025 2026
	if (order >= MAX_ORDER) {
		WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2027
		return NULL;
2028
	}
L
Linus Torvalds 已提交
2029

2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040
	/*
	 * 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;

2041
restart:
A
Andrea Arcangeli 已提交
2042 2043
	if (!(gfp_mask & __GFP_NO_KSWAPD))
		wake_all_kswapd(order, zonelist, high_zoneidx,
2044
						zone_idx(preferred_zone));
L
Linus Torvalds 已提交
2045

2046
	/*
R
Rohit Seth 已提交
2047 2048 2049
	 * 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.
2050
	 */
2051
	alloc_flags = gfp_to_alloc_flags(gfp_mask);
L
Linus Torvalds 已提交
2052

2053 2054 2055 2056 2057 2058 2059 2060
	/*
	 * Find the true preferred zone if the allocation is unconstrained by
	 * cpusets.
	 */
	if (!(alloc_flags & ALLOC_CPUSET) && !nodemask)
		first_zones_zonelist(zonelist, high_zoneidx, NULL,
					&preferred_zone);

2061
	/* This is the last chance, in general, before the goto nopage. */
2062
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
2063 2064
			high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
			preferred_zone, migratetype);
R
Rohit Seth 已提交
2065 2066
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
2067

2068
rebalance:
2069
	/* Allocate without watermarks if the context allows */
2070 2071 2072 2073 2074 2075
	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
2076 2077 2078 2079 2080 2081
	}

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

2082
	/* Avoid recursion of direct reclaim */
2083
	if (current->flags & PF_MEMALLOC)
2084 2085
		goto nopage;

2086 2087 2088 2089
	/* Avoid allocations with no watermarks from looping endlessly */
	if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
		goto nopage;

2090 2091 2092 2093
	/*
	 * Try direct compaction. The first pass is asynchronous. Subsequent
	 * attempts after direct reclaim are synchronous
	 */
2094 2095 2096 2097
	page = __alloc_pages_direct_compact(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
					alloc_flags, preferred_zone,
2098 2099
					migratetype, &did_some_progress,
					sync_migration);
2100 2101
	if (page)
		goto got_pg;
2102
	sync_migration = true;
2103

2104 2105 2106 2107
	/* Try direct reclaim and then allocating */
	page = __alloc_pages_direct_reclaim(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
2108
					alloc_flags, preferred_zone,
2109
					migratetype, &did_some_progress);
2110 2111
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
2112

2113
	/*
2114 2115
	 * If we failed to make any progress reclaiming, then we are
	 * running out of options and have to consider going OOM
2116
	 */
2117 2118
	if (!did_some_progress) {
		if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
2119 2120
			if (oom_killer_disabled)
				goto nopage;
2121 2122
			page = __alloc_pages_may_oom(gfp_mask, order,
					zonelist, high_zoneidx,
2123 2124
					nodemask, preferred_zone,
					migratetype);
2125 2126
			if (page)
				goto got_pg;
L
Linus Torvalds 已提交
2127

2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144
			if (!(gfp_mask & __GFP_NOFAIL)) {
				/*
				 * The oom killer is not called for high-order
				 * allocations that may fail, so if no progress
				 * is being made, there are no other options and
				 * retrying is unlikely to help.
				 */
				if (order > PAGE_ALLOC_COSTLY_ORDER)
					goto nopage;
				/*
				 * The oom killer is not called for lowmem
				 * allocations to prevent needlessly killing
				 * innocent tasks.
				 */
				if (high_zoneidx < ZONE_NORMAL)
					goto nopage;
			}
2145

2146 2147
			goto restart;
		}
L
Linus Torvalds 已提交
2148 2149
	}

2150
	/* Check if we should retry the allocation */
2151
	pages_reclaimed += did_some_progress;
2152 2153
	if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
		/* Wait for some write requests to complete then retry */
2154
		wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
L
Linus Torvalds 已提交
2155
		goto rebalance;
2156 2157 2158 2159 2160 2161 2162 2163 2164 2165
	} else {
		/*
		 * High-order allocations do not necessarily loop after
		 * direct reclaim and reclaim/compaction depends on compaction
		 * being called after reclaim so call directly if necessary
		 */
		page = __alloc_pages_direct_compact(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
					alloc_flags, preferred_zone,
2166 2167
					migratetype, &did_some_progress,
					sync_migration);
2168 2169
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
2170 2171 2172 2173
	}

nopage:
	if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188
		unsigned int filter = SHOW_MEM_FILTER_NODES;

		/*
		 * This documents exceptions given to allocations in certain
		 * contexts that are allowed to allocate outside current's set
		 * of allowed nodes.
		 */
		if (!(gfp_mask & __GFP_NOMEMALLOC))
			if (test_thread_flag(TIF_MEMDIE) ||
			    (current->flags & (PF_MEMALLOC | PF_EXITING)))
				filter &= ~SHOW_MEM_FILTER_NODES;
		if (in_interrupt() || !wait)
			filter &= ~SHOW_MEM_FILTER_NODES;

		pr_warning("%s: page allocation failure. order:%d, mode:0x%x\n",
2189
			current->comm, order, gfp_mask);
L
Linus Torvalds 已提交
2190
		dump_stack();
2191
		if (!should_suppress_show_mem())
2192
			__show_mem(filter);
L
Linus Torvalds 已提交
2193
	}
2194
	return page;
L
Linus Torvalds 已提交
2195
got_pg:
2196 2197
	if (kmemcheck_enabled)
		kmemcheck_pagealloc_alloc(page, order, gfp_mask);
L
Linus Torvalds 已提交
2198
	return page;
2199

L
Linus Torvalds 已提交
2200
}
2201 2202 2203 2204 2205 2206 2207 2208 2209

/*
 * 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);
2210
	struct zone *preferred_zone;
2211
	struct page *page;
2212
	int migratetype = allocflags_to_migratetype(gfp_mask);
2213

2214 2215
	gfp_mask &= gfp_allowed_mask;

2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230
	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;

2231
	get_mems_allowed();
2232
	/* The preferred zone is used for statistics later */
2233 2234 2235
	first_zones_zonelist(zonelist, high_zoneidx,
				nodemask ? : &cpuset_current_mems_allowed,
				&preferred_zone);
2236 2237
	if (!preferred_zone) {
		put_mems_allowed();
2238
		return NULL;
2239
	}
2240 2241

	/* First allocation attempt */
2242
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
2243
			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
2244
			preferred_zone, migratetype);
2245 2246
	if (unlikely(!page))
		page = __alloc_pages_slowpath(gfp_mask, order,
2247
				zonelist, high_zoneidx, nodemask,
2248
				preferred_zone, migratetype);
2249
	put_mems_allowed();
2250

2251
	trace_mm_page_alloc(page, order, gfp_mask, migratetype);
2252
	return page;
L
Linus Torvalds 已提交
2253
}
2254
EXPORT_SYMBOL(__alloc_pages_nodemask);
L
Linus Torvalds 已提交
2255 2256 2257 2258

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
2259
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
2260
{
2261 2262 2263 2264 2265 2266 2267 2268
	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
2269 2270 2271 2272 2273 2274 2275
	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
2276
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
2277
{
2278
	return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
L
Linus Torvalds 已提交
2279 2280 2281 2282 2283 2284 2285
}
EXPORT_SYMBOL(get_zeroed_page);

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

2286 2287
	while (--i >= 0) {
		trace_mm_pagevec_free(pvec->pages[i], pvec->cold);
L
Linus Torvalds 已提交
2288
		free_hot_cold_page(pvec->pages[i], pvec->cold);
2289
	}
L
Linus Torvalds 已提交
2290 2291
}

H
Harvey Harrison 已提交
2292
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
2293
{
N
Nick Piggin 已提交
2294
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
2295
		if (order == 0)
L
Li Hong 已提交
2296
			free_hot_cold_page(page, 0);
L
Linus Torvalds 已提交
2297 2298 2299 2300 2301 2302 2303
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
2304
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
2305 2306
{
	if (addr != 0) {
N
Nick Piggin 已提交
2307
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
2308 2309 2310 2311 2312 2313
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336
/**
 * 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
2337
		split_page(virt_to_page((void *)addr), order);
2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366
		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
2367 2368
static unsigned int nr_free_zone_pages(int offset)
{
2369
	struct zoneref *z;
2370 2371
	struct zone *zone;

2372
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
2373 2374
	unsigned int sum = 0;

2375
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
2376

2377
	for_each_zone_zonelist(zone, z, zonelist, offset) {
2378
		unsigned long size = zone->present_pages;
2379
		unsigned long high = high_wmark_pages(zone);
2380 2381
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
2382 2383 2384 2385 2386 2387 2388 2389 2390 2391
	}

	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
2392
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
2393
}
2394
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
2395 2396 2397 2398 2399 2400

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
2401
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
2402
}
2403 2404

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
2405
{
2406
	if (NUMA_BUILD)
2407
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
2408 2409 2410 2411 2412 2413
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
2414
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428
	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;
2429
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
2430
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2431
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2432 2433
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
2434 2435 2436 2437
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
2438 2439 2440 2441
	val->mem_unit = PAGE_SIZE;
}
#endif

2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460
/*
 * Determine whether the zone's node should be displayed or not, depending on
 * whether SHOW_MEM_FILTER_NODES was passed to __show_free_areas().
 */
static bool skip_free_areas_zone(unsigned int flags, const struct zone *zone)
{
	bool ret = false;

	if (!(flags & SHOW_MEM_FILTER_NODES))
		goto out;

	get_mems_allowed();
	ret = !node_isset(zone->zone_pgdat->node_id,
				cpuset_current_mems_allowed);
	put_mems_allowed();
out:
	return ret;
}

L
Linus Torvalds 已提交
2461 2462 2463 2464 2465 2466
#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.
2467 2468
 * Suppresses nodes that are not allowed by current's cpuset if
 * SHOW_MEM_FILTER_NODES is passed.
L
Linus Torvalds 已提交
2469
 */
2470
void __show_free_areas(unsigned int filter)
L
Linus Torvalds 已提交
2471
{
2472
	int cpu;
L
Linus Torvalds 已提交
2473 2474
	struct zone *zone;

2475
	for_each_populated_zone(zone) {
2476 2477
		if (skip_free_areas_zone(filter, zone))
			continue;
2478 2479
		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
2480

2481
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
2482 2483
			struct per_cpu_pageset *pageset;

2484
			pageset = per_cpu_ptr(zone->pageset, cpu);
L
Linus Torvalds 已提交
2485

2486 2487 2488
			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
2489 2490 2491
		}
	}

K
KOSAKI Motohiro 已提交
2492 2493
	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
2494
		" unevictable:%lu"
2495
		" dirty:%lu writeback:%lu unstable:%lu\n"
2496
		" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2497
		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2498 2499
		global_page_state(NR_ACTIVE_ANON),
		global_page_state(NR_INACTIVE_ANON),
K
KOSAKI Motohiro 已提交
2500 2501
		global_page_state(NR_ISOLATED_ANON),
		global_page_state(NR_ACTIVE_FILE),
2502
		global_page_state(NR_INACTIVE_FILE),
K
KOSAKI Motohiro 已提交
2503
		global_page_state(NR_ISOLATED_FILE),
L
Lee Schermerhorn 已提交
2504
		global_page_state(NR_UNEVICTABLE),
2505
		global_page_state(NR_FILE_DIRTY),
2506
		global_page_state(NR_WRITEBACK),
2507
		global_page_state(NR_UNSTABLE_NFS),
2508
		global_page_state(NR_FREE_PAGES),
2509 2510
		global_page_state(NR_SLAB_RECLAIMABLE),
		global_page_state(NR_SLAB_UNRECLAIMABLE),
2511
		global_page_state(NR_FILE_MAPPED),
2512
		global_page_state(NR_SHMEM),
2513 2514
		global_page_state(NR_PAGETABLE),
		global_page_state(NR_BOUNCE));
L
Linus Torvalds 已提交
2515

2516
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
2517 2518
		int i;

2519 2520
		if (skip_free_areas_zone(filter, zone))
			continue;
L
Linus Torvalds 已提交
2521 2522 2523 2524 2525 2526
		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
2527 2528 2529 2530
			" active_anon:%lukB"
			" inactive_anon:%lukB"
			" active_file:%lukB"
			" inactive_file:%lukB"
L
Lee Schermerhorn 已提交
2531
			" unevictable:%lukB"
K
KOSAKI Motohiro 已提交
2532 2533
			" isolated(anon):%lukB"
			" isolated(file):%lukB"
L
Linus Torvalds 已提交
2534
			" present:%lukB"
2535 2536 2537 2538
			" mlocked:%lukB"
			" dirty:%lukB"
			" writeback:%lukB"
			" mapped:%lukB"
2539
			" shmem:%lukB"
2540 2541
			" slab_reclaimable:%lukB"
			" slab_unreclaimable:%lukB"
2542
			" kernel_stack:%lukB"
2543 2544 2545 2546
			" pagetables:%lukB"
			" unstable:%lukB"
			" bounce:%lukB"
			" writeback_tmp:%lukB"
L
Linus Torvalds 已提交
2547 2548 2549 2550
			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
2551
			K(zone_page_state(zone, NR_FREE_PAGES)),
2552 2553 2554
			K(min_wmark_pages(zone)),
			K(low_wmark_pages(zone)),
			K(high_wmark_pages(zone)),
2555 2556 2557 2558
			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
2559
			K(zone_page_state(zone, NR_UNEVICTABLE)),
K
KOSAKI Motohiro 已提交
2560 2561
			K(zone_page_state(zone, NR_ISOLATED_ANON)),
			K(zone_page_state(zone, NR_ISOLATED_FILE)),
L
Linus Torvalds 已提交
2562
			K(zone->present_pages),
2563 2564 2565 2566
			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)),
2567
			K(zone_page_state(zone, NR_SHMEM)),
2568 2569
			K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
			K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
2570 2571
			zone_page_state(zone, NR_KERNEL_STACK) *
				THREAD_SIZE / 1024,
2572 2573 2574 2575
			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
2576
			zone->pages_scanned,
2577
			(zone->all_unreclaimable ? "yes" : "no")
L
Linus Torvalds 已提交
2578 2579 2580 2581 2582 2583 2584
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

2585
	for_each_populated_zone(zone) {
2586
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
L
Linus Torvalds 已提交
2587

2588 2589
		if (skip_free_areas_zone(filter, zone))
			continue;
L
Linus Torvalds 已提交
2590 2591 2592 2593 2594
		show_node(zone);
		printk("%s: ", zone->name);

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
2595 2596
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
L
Linus Torvalds 已提交
2597 2598
		}
		spin_unlock_irqrestore(&zone->lock, flags);
2599 2600
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
L
Linus Torvalds 已提交
2601 2602 2603
		printk("= %lukB\n", K(total));
	}

2604 2605
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

L
Linus Torvalds 已提交
2606 2607 2608
	show_swap_cache_info();
}

2609 2610 2611 2612 2613
void show_free_areas(void)
{
	__show_free_areas(0);
}

2614 2615 2616 2617 2618 2619
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
2620 2621
/*
 * Builds allocation fallback zone lists.
2622 2623
 *
 * Add all populated zones of a node to the zonelist.
L
Linus Torvalds 已提交
2624
 */
2625 2626
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
2627
{
2628 2629
	struct zone *zone;

2630
	BUG_ON(zone_type >= MAX_NR_ZONES);
2631
	zone_type++;
2632 2633

	do {
2634
		zone_type--;
2635
		zone = pgdat->node_zones + zone_type;
2636
		if (populated_zone(zone)) {
2637 2638
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
2639
			check_highest_zone(zone_type);
L
Linus Torvalds 已提交
2640
		}
2641

2642
	} while (zone_type);
2643
	return nr_zones;
L
Linus Torvalds 已提交
2644 2645
}

2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666

/*
 *  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
2667
#ifdef CONFIG_NUMA
2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700
/* 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)
{
2701 2702 2703 2704 2705 2706 2707 2708 2709 2710
	int ret;

	if (!s)
		return 0;

	ret = __parse_numa_zonelist_order(s);
	if (ret == 0)
		strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);

	return ret;
2711 2712 2713 2714 2715 2716 2717
}
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,
2718
		void __user *buffer, size_t *length,
2719 2720 2721 2722
		loff_t *ppos)
{
	char saved_string[NUMA_ZONELIST_ORDER_LEN];
	int ret;
2723
	static DEFINE_MUTEX(zl_order_mutex);
2724

2725
	mutex_lock(&zl_order_mutex);
2726
	if (write)
2727
		strcpy(saved_string, (char*)table->data);
2728
	ret = proc_dostring(table, write, buffer, length, ppos);
2729
	if (ret)
2730
		goto out;
2731 2732 2733 2734 2735 2736 2737 2738 2739
	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;
2740 2741
		} else if (oldval != user_zonelist_order) {
			mutex_lock(&zonelists_mutex);
2742
			build_all_zonelists(NULL);
2743 2744
			mutex_unlock(&zonelists_mutex);
		}
2745
	}
2746 2747 2748
out:
	mutex_unlock(&zl_order_mutex);
	return ret;
2749 2750 2751
}


2752
#define MAX_NODE_LOAD (nr_online_nodes)
2753 2754
static int node_load[MAX_NUMNODES];

L
Linus Torvalds 已提交
2755
/**
2756
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
Linus Torvalds 已提交
2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768
 * @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.
 */
2769
static int find_next_best_node(int node, nodemask_t *used_node_mask)
L
Linus Torvalds 已提交
2770
{
2771
	int n, val;
L
Linus Torvalds 已提交
2772 2773
	int min_val = INT_MAX;
	int best_node = -1;
2774
	const struct cpumask *tmp = cpumask_of_node(0);
L
Linus Torvalds 已提交
2775

2776 2777 2778 2779 2780
	/* 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
2781

2782
	for_each_node_state(n, N_HIGH_MEMORY) {
L
Linus Torvalds 已提交
2783 2784 2785 2786 2787 2788 2789 2790

		/* 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);

2791 2792 2793
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
Linus Torvalds 已提交
2794
		/* Give preference to headless and unused nodes */
2795 2796
		tmp = cpumask_of_node(n);
		if (!cpumask_empty(tmp))
L
Linus Torvalds 已提交
2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814
			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;
}

2815 2816 2817 2818 2819 2820 2821

/*
 * 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
2822
{
2823
	int j;
L
Linus Torvalds 已提交
2824
	struct zonelist *zonelist;
2825

2826
	zonelist = &pgdat->node_zonelists[0];
2827
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2828 2829 2830
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
2831 2832
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2833 2834
}

2835 2836 2837 2838 2839 2840 2841 2842
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

2843 2844
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2845 2846
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2847 2848
}

2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863
/*
 * 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;

2864 2865 2866 2867 2868 2869 2870
	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)) {
2871 2872
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
2873
				check_highest_zone(zone_type);
2874 2875 2876
			}
		}
	}
2877 2878
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
2879 2880 2881 2882 2883 2884 2885 2886 2887
}

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
2888
         * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
2889 2890
	 * If they are really small and used heavily, the system can fall
	 * into OOM very easily.
2891
	 * This function detect ZONE_DMA/DMA32 size and configures zone order.
2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902
	 */
	/* 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;
2903 2904 2905 2906 2907 2908 2909 2910 2911
			} 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;
2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922
			}
		}
	}
	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.
         */
2923 2924
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955
	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
2956
	nodemask_t used_mask;
2957 2958 2959
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
L
Linus Torvalds 已提交
2960 2961

	/* initialize zonelists */
2962
	for (i = 0; i < MAX_ZONELISTS; i++) {
L
Linus Torvalds 已提交
2963
		zonelist = pgdat->node_zonelists + i;
2964 2965
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
L
Linus Torvalds 已提交
2966 2967 2968 2969
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
2970
	load = nr_online_nodes;
L
Linus Torvalds 已提交
2971 2972
	prev_node = local_node;
	nodes_clear(used_mask);
2973 2974 2975 2976

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

L
Linus Torvalds 已提交
2977
	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2978 2979 2980 2981 2982 2983 2984 2985 2986
		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
2987 2988 2989 2990 2991
		/*
		 * 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.
		 */
2992
		if (distance != node_distance(local_node, prev_node))
2993 2994
			node_load[node] = load;

L
Linus Torvalds 已提交
2995 2996
		prev_node = node;
		load--;
2997 2998 2999 3000 3001
		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
3002

3003 3004 3005
	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
3006
	}
3007 3008

	build_thisnode_zonelists(pgdat);
L
Linus Torvalds 已提交
3009 3010
}

3011
/* Construct the zonelist performance cache - see further mmzone.h */
3012
static void build_zonelist_cache(pg_data_t *pgdat)
3013
{
3014 3015
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
3016
	struct zoneref *z;
3017

3018 3019 3020
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3021 3022
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3023 3024
}

3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042
#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
3043

L
Linus Torvalds 已提交
3044 3045
#else	/* CONFIG_NUMA */

3046 3047 3048 3049 3050 3051
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
3052
{
3053
	int node, local_node;
3054 3055
	enum zone_type j;
	struct zonelist *zonelist;
L
Linus Torvalds 已提交
3056 3057 3058

	local_node = pgdat->node_id;

3059 3060
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
3061

3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074
	/*
	 * 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
3075
	}
3076 3077 3078 3079 3080 3081 3082
	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);
	}

3083 3084
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
L
Linus Torvalds 已提交
3085 3086
}

3087
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3088
static void build_zonelist_cache(pg_data_t *pgdat)
3089
{
3090
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
3091 3092
}

L
Linus Torvalds 已提交
3093 3094
#endif	/* CONFIG_NUMA */

3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111
/*
 * 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);
3112
static void setup_zone_pageset(struct zone *zone);
3113

3114 3115 3116 3117 3118 3119
/*
 * 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);

3120
/* return values int ....just for stop_machine() */
3121
static __init_refok int __build_all_zonelists(void *data)
L
Linus Torvalds 已提交
3122
{
3123
	int nid;
3124
	int cpu;
3125

3126 3127 3128
#ifdef CONFIG_NUMA
	memset(node_load, 0, sizeof(node_load));
#endif
3129
	for_each_online_node(nid) {
3130 3131 3132 3133
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
3134
	}
3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148

	/*
	 * 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).
	 */
3149
	for_each_possible_cpu(cpu) {
3150 3151
		setup_pageset(&per_cpu(boot_pageset, cpu), 0);

3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165
#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
	}

3166 3167 3168
	return 0;
}

3169 3170 3171 3172
/*
 * Called with zonelists_mutex held always
 * unless system_state == SYSTEM_BOOTING.
 */
3173
void build_all_zonelists(void *data)
3174
{
3175 3176
	set_zonelist_order();

3177
	if (system_state == SYSTEM_BOOTING) {
3178
		__build_all_zonelists(NULL);
3179
		mminit_verify_zonelist();
3180 3181
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
3182
		/* we have to stop all cpus to guarantee there is no user
3183
		   of zonelist */
3184 3185 3186 3187 3188
#ifdef CONFIG_MEMORY_HOTPLUG
		if (data)
			setup_zone_pageset((struct zone *)data);
#endif
		stop_machine(__build_all_zonelists, NULL, NULL);
3189 3190
		/* cpuset refresh routine should be here */
	}
3191
	vm_total_pages = nr_free_pagecache_pages();
3192 3193 3194 3195 3196 3197 3198
	/*
	 * 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
	 */
3199
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
3200 3201 3202 3203 3204 3205
		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",
3206
			nr_online_nodes,
3207
			zonelist_order_name[current_zonelist_order],
3208
			page_group_by_mobility_disabled ? "off" : "on",
3209 3210 3211 3212
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
L
Linus Torvalds 已提交
3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227
}

/*
 * 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

3228
#ifndef CONFIG_MEMORY_HOTPLUG
3229
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246
{
	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);
}
3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269
#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
3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282

/*
 * 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))

3283
/*
3284
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3285 3286
 * 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
3287 3288 3289 3290 3291 3292 3293
 * 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;
3294 3295
	unsigned long block_migratetype;
	int reserve;
3296 3297 3298 3299

	/* 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;
3300
	reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
3301
							pageblock_order;
3302

3303 3304 3305 3306 3307 3308 3309 3310 3311
	/*
	 * 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);

3312
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
3313 3314 3315 3316
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

3317 3318 3319 3320
		/* Watch out for overlapping nodes */
		if (page_to_nid(page) != zone_to_nid(zone))
			continue;

3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350
		/* 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
3351

L
Linus Torvalds 已提交
3352 3353 3354 3355 3356
/*
 * 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.
 */
3357
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
3358
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
3359 3360
{
	struct page *page;
A
Andy Whitcroft 已提交
3361 3362
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
3363
	struct zone *z;
L
Linus Torvalds 已提交
3364

3365 3366 3367
	if (highest_memmap_pfn < end_pfn - 1)
		highest_memmap_pfn = end_pfn - 1;

3368
	z = &NODE_DATA(nid)->node_zones[zone];
3369
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380
		/*
		 * 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
3381 3382
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
3383
		mminit_verify_page_links(page, zone, nid, pfn);
3384
		init_page_count(page);
L
Linus Torvalds 已提交
3385 3386
		reset_page_mapcount(page);
		SetPageReserved(page);
3387 3388 3389 3390 3391
		/*
		 * 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
3392 3393 3394
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
3395 3396 3397 3398 3399
		 *
		 * 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.
3400
		 */
3401 3402 3403
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
3404
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
3405

L
Linus Torvalds 已提交
3406 3407 3408 3409
		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))
3410
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
3411 3412 3413 3414
#endif
	}
}

3415
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
3416
{
3417 3418 3419
	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
3420 3421 3422 3423 3424 3425
		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
3426
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
3427 3428
#endif

3429
static int zone_batchsize(struct zone *zone)
3430
{
3431
#ifdef CONFIG_MMU
3432 3433 3434 3435
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
3436
	 * size of the zone.  But no more than 1/2 of a meg.
3437 3438 3439 3440
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
3441 3442
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
3443 3444 3445 3446 3447
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
3448 3449 3450
	 * 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.
3451
	 *
3452 3453 3454 3455
	 * 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.
3456
	 */
3457
	batch = rounddown_pow_of_two(batch + batch/2) - 1;
3458

3459
	return batch;
3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476

#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
3477 3478
}

A
Adrian Bunk 已提交
3479
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3480 3481
{
	struct per_cpu_pages *pcp;
3482
	int migratetype;
3483

3484 3485
	memset(p, 0, sizeof(*p));

3486
	pcp = &p->pcp;
3487 3488 3489
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
3490 3491
	for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
		INIT_LIST_HEAD(&pcp->lists[migratetype]);
3492 3493
}

3494 3495 3496 3497 3498 3499 3500 3501 3502 3503
/*
 * 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;

3504
	pcp = &p->pcp;
3505 3506 3507 3508 3509 3510
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}

3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528
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));
	}
}

3529
/*
3530 3531
 * Allocate per cpu pagesets and initialize them.
 * Before this call only boot pagesets were available.
3532
 */
3533
void __init setup_per_cpu_pageset(void)
3534
{
3535
	struct zone *zone;
3536

3537 3538
	for_each_populated_zone(zone)
		setup_zone_pageset(zone);
3539 3540
}

S
Sam Ravnborg 已提交
3541
static noinline __init_refok
3542
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3543 3544 3545
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
3546
	size_t alloc_size;
3547 3548 3549 3550 3551

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
3552 3553 3554 3555
	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);
3556 3557 3558
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

3559
	if (!slab_is_available()) {
3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572
		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.
		 */
3573
		zone->wait_table = vmalloc(alloc_size);
3574 3575 3576
	}
	if (!zone->wait_table)
		return -ENOMEM;
3577

3578
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3579
		init_waitqueue_head(zone->wait_table + i);
3580 3581

	return 0;
3582 3583
}

3584 3585 3586 3587 3588 3589
static int __zone_pcp_update(void *data)
{
	struct zone *zone = data;
	int cpu;
	unsigned long batch = zone_batchsize(zone), flags;

3590
	for_each_possible_cpu(cpu) {
3591 3592 3593
		struct per_cpu_pageset *pset;
		struct per_cpu_pages *pcp;

3594
		pset = per_cpu_ptr(zone->pageset, cpu);
3595 3596 3597
		pcp = &pset->pcp;

		local_irq_save(flags);
3598
		free_pcppages_bulk(zone, pcp->count, pcp);
3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609
		setup_pageset(pset, batch);
		local_irq_restore(flags);
	}
	return 0;
}

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

3610
static __meminit void zone_pcp_init(struct zone *zone)
3611
{
3612 3613 3614 3615 3616 3617
	/*
	 * 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;
3618

A
Anton Blanchard 已提交
3619
	if (zone->present_pages)
3620 3621 3622
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%u\n",
			zone->name, zone->present_pages,
					 zone_batchsize(zone));
3623 3624
}

3625 3626
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
3627 3628
					unsigned long size,
					enum memmap_context context)
3629 3630
{
	struct pglist_data *pgdat = zone->zone_pgdat;
3631 3632 3633 3634
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
3635 3636 3637 3638
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

3639 3640 3641 3642 3643 3644
	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));

3645
	zone_init_free_lists(zone);
3646 3647

	return 0;
3648 3649
}

3650 3651 3652 3653 3654
#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
 */
3655
static int __meminit first_active_region_index_in_nid(int nid)
3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667
{
	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
3668
 * Note: nid == MAX_NUMNODES returns next region regardless of node
3669
 */
3670
static int __meminit next_active_region_index_in_nid(int index, int nid)
3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685
{
	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
 */
3686
int __meminit __early_pfn_to_nid(unsigned long pfn)
3687 3688 3689 3690 3691 3692 3693 3694 3695 3696
{
	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;
	}
3697 3698
	/* This is a memory hole */
	return -1;
3699 3700 3701
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

3702 3703
int __meminit early_pfn_to_nid(unsigned long pfn)
{
3704 3705 3706 3707 3708 3709 3710
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0)
		return nid;
	/* just returns 0 */
	return 0;
3711 3712
}

3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723
#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
3724

3725 3726 3727 3728 3729 3730 3731
/* 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
3732 3733
 * @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
3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760
 *
 * 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);
	}
}

3761
#ifdef CONFIG_HAVE_MEMBLOCK
3762 3763 3764 3765 3766 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 3792 3793
/*
 * Basic iterator support. Return the last range of PFNs for a node
 * Note: nid == MAX_NUMNODES returns last region regardless of node
 */
static int __meminit last_active_region_index_in_nid(int nid)
{
	int i;

	for (i = nr_nodemap_entries - 1; i >= 0; i--)
		if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
			return i;

	return -1;
}

/*
 * Basic iterator support. Return the previous active range of PFNs for a node
 * Note: nid == MAX_NUMNODES returns next region regardless of node
 */
static int __meminit previous_active_region_index_in_nid(int index, int nid)
{
	for (index = index - 1; index >= 0; index--)
		if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
			return index;

	return -1;
}

#define for_each_active_range_index_in_nid_reverse(i, nid) \
	for (i = last_active_region_index_in_nid(nid); i != -1; \
				i = previous_active_region_index_in_nid(i, nid))

3794 3795 3796 3797 3798 3799
u64 __init find_memory_core_early(int nid, u64 size, u64 align,
					u64 goal, u64 limit)
{
	int i;

	/* Need to go over early_node_map to find out good range for node */
3800
	for_each_active_range_index_in_nid_reverse(i, nid) {
3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827
		u64 addr;
		u64 ei_start, ei_last;
		u64 final_start, final_end;

		ei_last = early_node_map[i].end_pfn;
		ei_last <<= PAGE_SHIFT;
		ei_start = early_node_map[i].start_pfn;
		ei_start <<= PAGE_SHIFT;

		final_start = max(ei_start, goal);
		final_end = min(ei_last, limit);

		if (final_start >= final_end)
			continue;

		addr = memblock_find_in_range(final_start, final_end, size, align);

		if (addr == MEMBLOCK_ERROR)
			continue;

		return addr;
	}

	return MEMBLOCK_ERROR;
}
#endif

3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842
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;
}

3843 3844 3845
void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
{
	int i;
3846
	int ret;
3847

3848 3849 3850 3851 3852 3853
	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;
	}
3854
}
3855 3856
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3857
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3858 3859 3860
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
3861
 * function may be used instead of calling memory_present() manually.
3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874
 */
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
3875 3876 3877
 * @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.
3878 3879 3880 3881
 *
 * 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
3882
 * PFNs will be 0.
3883
 */
3884
void __meminit get_pfn_range_for_nid(unsigned int nid,
3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895
			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);
	}

3896
	if (*start_pfn == -1UL)
3897 3898 3899
		*start_pfn = 0;
}

M
Mel Gorman 已提交
3900 3901 3902 3903 3904
/*
 * 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
3905
static void __init find_usable_zone_for_movable(void)
M
Mel Gorman 已提交
3906 3907 3908 3909 3910 3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930
{
	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
3931
static void __meminit adjust_zone_range_for_zone_movable(int nid,
M
Mel Gorman 已提交
3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956
					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;
	}
}

3957 3958 3959 3960
/*
 * 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
3961
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3962 3963 3964 3965 3966 3967 3968 3969 3970 3971
					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
3972 3973 3974
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989

	/* 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,
3990
 * then all holes in the requested range will be accounted for.
3991
 */
3992
unsigned long __meminit __absent_pages_in_range(int nid,
3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004
				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;

4005 4006
	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);

4007 4008
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
4009
		hole_pages = prev_end_pfn - range_start_pfn;
4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029

	/* 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;
	}

4030 4031
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
4032
		hole_pages += range_end_pfn -
4033 4034
				max(range_start_pfn, prev_end_pfn);

4035 4036 4037 4038 4039 4040 4041 4042
	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
 *
4043
 * It returns the number of pages frames in memory holes within a range.
4044 4045 4046 4047 4048 4049 4050 4051
 */
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
4052
static unsigned long __meminit zone_absent_pages_in_node(int nid,
4053 4054 4055
					unsigned long zone_type,
					unsigned long *ignored)
{
4056 4057 4058 4059 4060 4061 4062 4063 4064
	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
4065 4066 4067
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
4068
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
4069
}
4070

4071
#else
P
Paul Mundt 已提交
4072
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
4073 4074 4075 4076 4077 4078
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
4079
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
4080 4081 4082 4083 4084 4085 4086 4087
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
4088

4089 4090
#endif

4091
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
4092 4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111
		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);
}

4112 4113 4114
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
4115 4116
 * 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
4117 4118 4119 4120 4121 4122 4123
 * 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;

4124 4125
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136
	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;
4137
	if (usemapsize)
4138 4139 4140
		zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize);
}
#else
4141
static inline void setup_usemap(struct pglist_data *pgdat,
4142 4143 4144
				struct zone *zone, unsigned long zonesize) {}
#endif /* CONFIG_SPARSEMEM */

4145
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4146 4147 4148 4149 4150 4151 4152 4153 4154 4155

/* 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;
}

4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170
/* 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 */

4171 4172 4173 4174 4175 4176 4177 4178 4179 4180
/*
 * 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;
}
4181 4182 4183 4184
#define set_pageblock_order(x)	do {} while (0)

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
4185 4186 4187 4188 4189 4190
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
4191
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
4192 4193
		unsigned long *zones_size, unsigned long *zholes_size)
{
4194
	enum zone_type j;
4195
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
4196
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
4197
	int ret;
L
Linus Torvalds 已提交
4198

4199
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
4200 4201 4202
	pgdat->nr_zones = 0;
	init_waitqueue_head(&pgdat->kswapd_wait);
	pgdat->kswapd_max_order = 0;
4203
	pgdat_page_cgroup_init(pgdat);
L
Linus Torvalds 已提交
4204 4205 4206
	
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
4207
		unsigned long size, realsize, memmap_pages;
4208
		enum lru_list l;
L
Linus Torvalds 已提交
4209

4210 4211 4212
		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
4213

4214 4215 4216 4217 4218
		/*
		 * 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
		 */
4219 4220
		memmap_pages =
			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
4221 4222
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
4223 4224 4225 4226
			if (memmap_pages)
				printk(KERN_DEBUG
				       "  %s zone: %lu pages used for memmap\n",
				       zone_names[j], memmap_pages);
4227 4228 4229 4230 4231
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

4232 4233
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
4234
			realsize -= dma_reserve;
Y
Yinghai Lu 已提交
4235
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
4236
					zone_names[0], dma_reserve);
4237 4238
		}

4239
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
4240 4241 4242 4243 4244
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
4245
#ifdef CONFIG_NUMA
4246
		zone->node = nid;
4247
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
4248
						/ 100;
4249
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
4250
#endif
L
Linus Torvalds 已提交
4251 4252 4253
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
4254
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
4255 4256
		zone->zone_pgdat = pgdat;

4257
		zone_pcp_init(zone);
4258 4259
		for_each_lru(l) {
			INIT_LIST_HEAD(&zone->lru[l].list);
4260
			zone->reclaim_stat.nr_saved_scan[l] = 0;
4261
		}
4262 4263 4264 4265
		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;
4266
		zap_zone_vm_stats(zone);
4267
		zone->flags = 0;
L
Linus Torvalds 已提交
4268 4269 4270
		if (!size)
			continue;

4271
		set_pageblock_order(pageblock_default_order());
4272
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
4273 4274
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
4275
		BUG_ON(ret);
4276
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
4277 4278 4279 4280
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
4281
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
4282 4283 4284 4285 4286
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
4287
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
4288 4289
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
4290
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
4291 4292
		struct page *map;

4293 4294 4295 4296 4297 4298 4299 4300 4301
		/*
		 * 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);
4302 4303 4304
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
4305
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
4306
	}
4307
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
4308 4309 4310
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
4311
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
4312
		mem_map = NODE_DATA(0)->node_mem_map;
4313 4314
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4315
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
4316 4317
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
4318
#endif
A
Andy Whitcroft 已提交
4319
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
4320 4321
}

4322 4323
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
4324
{
4325 4326
	pg_data_t *pgdat = NODE_DATA(nid);

L
Linus Torvalds 已提交
4327 4328
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
4329
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
4330 4331

	alloc_node_mem_map(pgdat);
4332 4333 4334 4335 4336
#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
4337 4338 4339 4340

	free_area_init_core(pgdat, zones_size, zholes_size);
}

4341
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
M
Miklos Szeredi 已提交
4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361

#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

4362 4363 4364 4365 4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376 4377 4378
/**
 * 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;

4379 4380 4381 4382 4383
	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);
4384

4385 4386
	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);

4387 4388 4389 4390 4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404
	/* 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 */
4405
		if (start_pfn < early_node_map[i].start_pfn &&
4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425
				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;
}

/**
4426
 * remove_active_range - Shrink an existing registered range of PFNs
4427
 * @nid: The node id the range is on that should be shrunk
4428 4429
 * @start_pfn: The new PFN of the range
 * @end_pfn: The new PFN of the range
4430 4431
 *
 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
4432 4433 4434
 * 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.
4435
 */
4436 4437
void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
				unsigned long end_pfn)
4438
{
4439 4440
	int i, j;
	int removed = 0;
4441

4442 4443 4444
	printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
			  nid, start_pfn, end_pfn);

4445
	/* Find the old active region end and shrink */
4446
	for_each_active_range_index_in_nid(i, nid) {
4447 4448
		if (early_node_map[i].start_pfn >= start_pfn &&
		    early_node_map[i].end_pfn <= end_pfn) {
4449
			/* clear it */
4450
			early_node_map[i].start_pfn = 0;
4451 4452 4453 4454
			early_node_map[i].end_pfn = 0;
			removed = 1;
			continue;
		}
4455 4456 4457 4458 4459 4460 4461 4462 4463 4464 4465 4466
		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;
4467
			continue;
4468
		}
4469 4470 4471 4472 4473 4474 4475 4476 4477 4478 4479 4480 4481 4482 4483 4484 4485 4486 4487
	}

	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--;
	}
4488 4489 4490 4491
}

/**
 * remove_all_active_ranges - Remove all currently registered regions
4492
 *
4493 4494 4495 4496
 * 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.
 */
4497
void __init remove_all_active_ranges(void)
4498 4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516 4517 4518
{
	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 */
4519
void __init sort_node_map(void)
4520 4521 4522 4523 4524 4525
{
	sort(early_node_map, (size_t)nr_nodemap_entries,
			sizeof(struct node_active_region),
			cmp_node_active_region, NULL);
}

4526
/* Find the lowest pfn for a node */
A
Adrian Bunk 已提交
4527
static unsigned long __init find_min_pfn_for_node(int nid)
4528 4529
{
	int i;
4530
	unsigned long min_pfn = ULONG_MAX;
4531

4532 4533
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
4534
		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
4535

4536 4537
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
4538
			"Could not find start_pfn for node %d\n", nid);
4539 4540 4541 4542
		return 0;
	}

	return min_pfn;
4543 4544 4545 4546 4547 4548
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
4549
 * add_active_range().
4550 4551 4552 4553 4554 4555
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

4556 4557 4558 4559 4560
/*
 * 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
4561
static unsigned long __init early_calculate_totalpages(void)
4562 4563 4564 4565
{
	int i;
	unsigned long totalpages = 0;

4566 4567
	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long pages = early_node_map[i].end_pfn -
4568
						early_node_map[i].start_pfn;
4569 4570 4571 4572 4573
		totalpages += pages;
		if (pages)
			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
	}
  	return totalpages;
4574 4575
}

M
Mel Gorman 已提交
4576 4577 4578 4579 4580 4581
/*
 * 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
4582
static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
M
Mel Gorman 已提交
4583 4584 4585 4586
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
4587 4588
	/* save the state before borrow the nodemask */
	nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4589 4590
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
4591

4592 4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603 4604 4605 4606 4607 4608 4609 4610 4611 4612 4613
	/*
	 * 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
4614 4615
	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
	if (!required_kernelcore)
4616
		goto out;
M
Mel Gorman 已提交
4617 4618 4619 4620 4621 4622 4623 4624

	/* 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;
4625
	for_each_node_state(nid, N_HIGH_MEMORY) {
M
Mel Gorman 已提交
4626 4627 4628 4629 4630 4631 4632 4633 4634 4635 4636 4637 4638 4639 4640 4641 4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655 4656 4657 4658 4659 4660 4661 4662 4663 4664 4665 4666 4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689 4690 4691 4692 4693 4694 4695 4696 4697 4698 4699 4700 4701 4702 4703 4704 4705 4706 4707 4708 4709 4710 4711 4712 4713 4714
		/*
		 * 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);
4715 4716 4717 4718

out:
	/* restore the node_state */
	node_states[N_HIGH_MEMORY] = saved_node_state;
M
Mel Gorman 已提交
4719 4720
}

4721 4722 4723 4724 4725 4726 4727 4728 4729 4730 4731 4732 4733 4734
/* 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
}

4735 4736
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
4737
 * @max_zone_pfn: an array of max PFNs for each zone
4738 4739 4740 4741 4742 4743 4744 4745 4746 4747 4748 4749 4750
 *
 * 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;
4751
	int i;
4752

4753 4754 4755
	/* Sort early_node_map as initialisation assumes it is sorted */
	sort_node_map();

4756 4757 4758 4759 4760 4761 4762 4763
	/* 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
4764 4765
		if (i == ZONE_MOVABLE)
			continue;
4766 4767 4768 4769 4770
		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
4771 4772 4773 4774 4775 4776
	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);
4777 4778 4779

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
M
Mel Gorman 已提交
4780 4781 4782
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
4783 4784 4785 4786 4787 4788
		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",
4789 4790
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);
M
Mel Gorman 已提交
4791 4792 4793 4794 4795 4796 4797 4798
	}

	/* 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]);
	}
4799 4800 4801 4802

	/* 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++)
4803
		printk("  %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4804 4805 4806 4807
						early_node_map[i].start_pfn,
						early_node_map[i].end_pfn);

	/* Initialise every node */
4808
	mminit_verify_pageflags_layout();
4809
	setup_nr_node_ids();
4810 4811
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
4812
		free_area_init_node(nid, NULL,
4813
				find_min_pfn_for_node(nid), NULL);
4814 4815 4816 4817 4818

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
4819 4820
	}
}
M
Mel Gorman 已提交
4821

4822
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
4823 4824 4825 4826 4827 4828
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
4829
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
4830

4831
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
4832 4833 4834 4835
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
4836

4837 4838 4839 4840 4841 4842 4843 4844 4845 4846 4847 4848 4849 4850 4851 4852 4853 4854
/*
 * 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
4855
early_param("kernelcore", cmdline_parse_kernelcore);
4856
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
4857

4858 4859
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

4860
/**
4861 4862
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
4863 4864 4865 4866
 *
 * 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
4867 4868 4869
 * 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.
4870 4871 4872 4873 4874 4875
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

L
Linus Torvalds 已提交
4876 4877
void __init free_area_init(unsigned long *zones_size)
{
4878
	free_area_init_node(0, zones_size,
L
Linus Torvalds 已提交
4879 4880 4881 4882 4883 4884 4885 4886
			__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;

4887
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4888 4889 4890 4891 4892 4893 4894 4895
		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.
		 */
4896
		vm_events_fold_cpu(cpu);
4897 4898 4899 4900 4901 4902 4903 4904

		/*
		 * 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.
		 */
4905
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
4906 4907 4908 4909 4910 4911 4912 4913 4914
	}
	return NOTIFY_OK;
}

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

4915 4916 4917 4918 4919 4920 4921 4922
/*
 * 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;
4923
	enum zone_type i, j;
4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935

	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];
			}

4936 4937
			/* we treat the high watermark as reserved pages. */
			max += high_wmark_pages(zone);
4938 4939 4940 4941 4942 4943 4944 4945 4946

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

L
Linus Torvalds 已提交
4947 4948 4949 4950 4951 4952 4953 4954 4955
/*
 * 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;
4956
	enum zone_type j, idx;
L
Linus Torvalds 已提交
4957

4958
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
4959 4960 4961 4962 4963 4964
		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;

4965 4966
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
4967 4968
				struct zone *lower_zone;

4969 4970
				idx--;

L
Linus Torvalds 已提交
4971 4972 4973 4974 4975 4976 4977 4978 4979 4980
				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;
			}
		}
	}
4981 4982 4983

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4984 4985
}

4986
/**
4987
 * setup_per_zone_wmarks - called when min_free_kbytes changes
4988
 * or when memory is hot-{added|removed}
4989
 *
4990 4991
 * 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
4992
 */
4993
void setup_per_zone_wmarks(void)
L
Linus Torvalds 已提交
4994 4995 4996 4997 4998 4999 5000 5001 5002 5003 5004 5005 5006
{
	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) {
5007 5008
		u64 tmp;

5009
		spin_lock_irqsave(&zone->lock, flags);
5010 5011
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
5012 5013
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
5014 5015 5016 5017
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
5018
			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
N
Nick Piggin 已提交
5019 5020
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
Linus Torvalds 已提交
5021 5022 5023 5024 5025 5026 5027 5028
			 */
			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;
5029
			zone->watermark[WMARK_MIN] = min_pages;
L
Linus Torvalds 已提交
5030
		} else {
N
Nick Piggin 已提交
5031 5032
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
5033 5034
			 * proportionate to the zone's size.
			 */
5035
			zone->watermark[WMARK_MIN] = tmp;
L
Linus Torvalds 已提交
5036 5037
		}

5038 5039
		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) + (tmp >> 2);
		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
5040
		setup_zone_migrate_reserve(zone);
5041
		spin_unlock_irqrestore(&zone->lock, flags);
L
Linus Torvalds 已提交
5042
	}
5043 5044 5045

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
5046 5047
}

5048
/*
5049 5050 5051 5052 5053 5054 5055 5056 5057 5058 5059 5060 5061 5062 5063 5064 5065 5066 5067 5068
 * 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
 */
5069
void calculate_zone_inactive_ratio(struct zone *zone)
5070
{
5071
	unsigned int gb, ratio;
5072

5073 5074 5075
	/* Zone size in gigabytes */
	gb = zone->present_pages >> (30 - PAGE_SHIFT);
	if (gb)
5076
		ratio = int_sqrt(10 * gb);
5077 5078
	else
		ratio = 1;
5079

5080 5081
	zone->inactive_ratio = ratio;
}
5082

5083 5084 5085 5086 5087 5088
static void __init setup_per_zone_inactive_ratio(void)
{
	struct zone *zone;

	for_each_zone(zone)
		calculate_zone_inactive_ratio(zone);
5089 5090
}

L
Linus Torvalds 已提交
5091 5092 5093 5094 5095 5096 5097 5098 5099 5100 5101 5102 5103 5104 5105 5106 5107 5108 5109 5110 5111 5112 5113 5114
/*
 * 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
 */
5115
static int __init init_per_zone_wmark_min(void)
L
Linus Torvalds 已提交
5116 5117 5118 5119 5120 5121 5122 5123 5124 5125
{
	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;
5126
	setup_per_zone_wmarks();
L
Linus Torvalds 已提交
5127
	setup_per_zone_lowmem_reserve();
5128
	setup_per_zone_inactive_ratio();
L
Linus Torvalds 已提交
5129 5130
	return 0;
}
5131
module_init(init_per_zone_wmark_min)
L
Linus Torvalds 已提交
5132 5133 5134 5135 5136 5137 5138

/*
 * 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, 
5139
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
5140
{
5141
	proc_dointvec(table, write, buffer, length, ppos);
5142
	if (write)
5143
		setup_per_zone_wmarks();
L
Linus Torvalds 已提交
5144 5145 5146
	return 0;
}

5147 5148
#ifdef CONFIG_NUMA
int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
5149
	void __user *buffer, size_t *length, loff_t *ppos)
5150 5151 5152 5153
{
	struct zone *zone;
	int rc;

5154
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5155 5156 5157 5158
	if (rc)
		return rc;

	for_each_zone(zone)
5159
		zone->min_unmapped_pages = (zone->present_pages *
5160 5161 5162
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
5163 5164

int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
5165
	void __user *buffer, size_t *length, loff_t *ppos)
5166 5167 5168 5169
{
	struct zone *zone;
	int rc;

5170
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5171 5172 5173 5174 5175 5176 5177 5178
	if (rc)
		return rc;

	for_each_zone(zone)
		zone->min_slab_pages = (zone->present_pages *
				sysctl_min_slab_ratio) / 100;
	return 0;
}
5179 5180
#endif

L
Linus Torvalds 已提交
5181 5182 5183 5184 5185 5186
/*
 * 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
5187
 * minimum watermarks. The lowmem reserve ratio can only make sense
L
Linus Torvalds 已提交
5188 5189 5190
 * if in function of the boot time zone sizes.
 */
int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
5191
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
5192
{
5193
	proc_dointvec_minmax(table, write, buffer, length, ppos);
L
Linus Torvalds 已提交
5194 5195 5196 5197
	setup_per_zone_lowmem_reserve();
	return 0;
}

5198 5199 5200 5201 5202 5203 5204
/*
 * 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,
5205
	void __user *buffer, size_t *length, loff_t *ppos)
5206 5207 5208 5209 5210
{
	struct zone *zone;
	unsigned int cpu;
	int ret;

5211
	ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5212 5213
	if (!write || (ret == -EINVAL))
		return ret;
5214
	for_each_populated_zone(zone) {
5215
		for_each_possible_cpu(cpu) {
5216 5217
			unsigned long  high;
			high = zone->present_pages / percpu_pagelist_fraction;
5218 5219
			setup_pagelist_highmark(
				per_cpu_ptr(zone->pageset, cpu), high);
5220 5221 5222 5223 5224
		}
	}
	return 0;
}

5225
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
5226 5227 5228 5229 5230 5231 5232 5233 5234 5235 5236 5237 5238 5239 5240 5241 5242 5243 5244 5245 5246 5247 5248 5249 5250 5251 5252 5253 5254 5255 5256 5257 5258 5259

#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
5260
		numentries = nr_kernel_pages;
L
Linus Torvalds 已提交
5261 5262 5263 5264 5265 5266 5267 5268 5269
		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);
5270 5271

		/* Make sure we've got at least a 0-order allocation.. */
5272 5273 5274 5275 5276 5277 5278 5279
		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))
5280
			numentries = PAGE_SIZE / bucketsize;
L
Linus Torvalds 已提交
5281
	}
5282
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
5283 5284 5285 5286 5287 5288 5289 5290 5291 5292

	/* 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;

5293
	log2qty = ilog2(numentries);
L
Linus Torvalds 已提交
5294 5295 5296 5297

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
5298
			table = alloc_bootmem_nopanic(size);
L
Linus Torvalds 已提交
5299 5300 5301
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
5302 5303
			/*
			 * If bucketsize is not a power-of-two, we may free
5304 5305
			 * some pages at the end of hash table which
			 * alloc_pages_exact() automatically does
5306
			 */
5307
			if (get_order(size) < MAX_ORDER) {
5308
				table = alloc_pages_exact(size, GFP_ATOMIC);
5309 5310
				kmemleak_alloc(table, size, 1, GFP_ATOMIC);
			}
L
Linus Torvalds 已提交
5311 5312 5313 5314 5315 5316
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

5317
	printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
L
Linus Torvalds 已提交
5318
	       tablename,
5319
	       (1UL << log2qty),
5320
	       ilog2(size) - PAGE_SHIFT,
L
Linus Torvalds 已提交
5321 5322 5323 5324 5325 5326 5327 5328 5329
	       size);

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

	return table;
}
5330

5331 5332 5333 5334 5335 5336 5337 5338 5339 5340 5341 5342 5343 5344 5345
/* 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);
5346
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5347 5348
#else
	pfn = pfn - zone->zone_start_pfn;
5349
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5350 5351 5352 5353
#endif /* CONFIG_SPARSEMEM */
}

/**
5354
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5355 5356 5357 5358 5359 5360 5361 5362 5363 5364 5365 5366 5367 5368 5369 5370 5371 5372 5373 5374 5375 5376
 * @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;
5377

5378 5379 5380 5381
	return flags;
}

/**
5382
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5383 5384 5385 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395 5396 5397 5398 5399
 * @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);
5400 5401
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
5402 5403 5404 5405 5406 5407 5408

	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
5409 5410 5411 5412 5413 5414 5415

/*
 * 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.
 */

5416 5417 5418 5419 5420 5421 5422 5423 5424 5425 5426 5427 5428 5429 5430 5431 5432 5433
static int
__count_immobile_pages(struct zone *zone, struct page *page, int count)
{
	unsigned long pfn, iter, found;
	/*
	 * For avoiding noise data, lru_add_drain_all() should be called
	 * If ZONE_MOVABLE, the zone never contains immobile pages
	 */
	if (zone_idx(zone) == ZONE_MOVABLE)
		return true;

	if (get_pageblock_migratetype(page) == MIGRATE_MOVABLE)
		return true;

	pfn = page_to_pfn(page);
	for (found = 0, iter = 0; iter < pageblock_nr_pages; iter++) {
		unsigned long check = pfn + iter;

5434
		if (!pfn_valid_within(check))
5435
			continue;
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
		page = pfn_to_page(check);
		if (!page_count(page)) {
			if (PageBuddy(page))
				iter += (1 << page_order(page)) - 1;
			continue;
		}
		if (!PageLRU(page))
			found++;
		/*
		 * If there are RECLAIMABLE pages, we need to check it.
		 * But now, memory offline itself doesn't call shrink_slab()
		 * and it still to be fixed.
		 */
		/*
		 * If the page is not RAM, page_count()should be 0.
		 * we don't need more check. This is an _used_ not-movable page.
		 *
		 * The problematic thing here is PG_reserved pages. PG_reserved
		 * is set to both of a memory hole page and a _used_ kernel
		 * page at boot.
		 */
		if (found > count)
			return false;
	}
	return true;
}

bool is_pageblock_removable_nolock(struct page *page)
{
	struct zone *zone = page_zone(page);
	return __count_immobile_pages(zone, page, 0);
}

K
KAMEZAWA Hiroyuki 已提交
5470 5471 5472
int set_migratetype_isolate(struct page *page)
{
	struct zone *zone;
5473
	unsigned long flags, pfn;
5474 5475
	struct memory_isolate_notify arg;
	int notifier_ret;
K
KAMEZAWA Hiroyuki 已提交
5476
	int ret = -EBUSY;
5477
	int zone_idx;
K
KAMEZAWA Hiroyuki 已提交
5478 5479

	zone = page_zone(page);
5480
	zone_idx = zone_idx(zone);
5481

K
KAMEZAWA Hiroyuki 已提交
5482
	spin_lock_irqsave(&zone->lock, flags);
5483 5484 5485 5486 5487 5488

	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
5489
	/*
5490 5491 5492 5493 5494 5495 5496 5497 5498
	 * 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
5499
	 */
5500 5501
	notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);
	notifier_ret = notifier_to_errno(notifier_ret);
5502
	if (notifier_ret)
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		goto out;
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	/*
	 * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself.
	 * We just check MOVABLE pages.
	 */
	if (__count_immobile_pages(zone, page, arg.pages_found))
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		ret = 0;

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	/*
	 * immobile means "not-on-lru" paes. If immobile is larger than
	 * removable-by-driver pages reported by notifier, we'll fail.
	 */

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out:
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	if (!ret) {
		set_pageblock_migratetype(page, MIGRATE_ISOLATE);
		move_freepages_block(zone, page, MIGRATE_ISOLATE);
	}

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	spin_unlock_irqrestore(&zone->lock, flags);
	if (!ret)
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		drain_all_pages();
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	return ret;
}

void unset_migratetype_isolate(struct page *page)
{
	struct zone *zone;
	unsigned long flags;
	zone = page_zone(page);
	spin_lock_irqsave(&zone->lock, flags);
	if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
		goto out;
	set_pageblock_migratetype(page, MIGRATE_MOVABLE);
	move_freepages_block(zone, page, MIGRATE_MOVABLE);
out:
	spin_unlock_irqrestore(&zone->lock, flags);
}
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#ifdef CONFIG_MEMORY_HOTREMOVE
/*
 * All pages in the range must be isolated before calling this.
 */
void
__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
{
	struct page *page;
	struct zone *zone;
	int order, i;
	unsigned long pfn;
	unsigned long flags;
	/* find the first valid pfn */
	for (pfn = start_pfn; pfn < end_pfn; pfn++)
		if (pfn_valid(pfn))
			break;
	if (pfn == end_pfn)
		return;
	zone = page_zone(pfn_to_page(pfn));
	spin_lock_irqsave(&zone->lock, flags);
	pfn = start_pfn;
	while (pfn < end_pfn) {
		if (!pfn_valid(pfn)) {
			pfn++;
			continue;
		}
		page = pfn_to_page(pfn);
		BUG_ON(page_count(page));
		BUG_ON(!PageBuddy(page));
		order = page_order(page);
#ifdef CONFIG_DEBUG_VM
		printk(KERN_INFO "remove from free list %lx %d %lx\n",
		       pfn, 1 << order, end_pfn);
#endif
		list_del(&page->lru);
		rmv_page_order(page);
		zone->free_area[order].nr_free--;
		__mod_zone_page_state(zone, NR_FREE_PAGES,
				      - (1UL << order));
		for (i = 0; i < (1 << order); i++)
			SetPageReserved((page+i));
		pfn += (1 << order);
	}
	spin_unlock_irqrestore(&zone->lock, flags);
}
#endif
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#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
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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_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",
5681
		page, atomic_read(&page->_count), page_mapcount(page),
5682 5683 5684
		page->mapping, page->index);
	dump_page_flags(page->flags);
}