page_alloc.c 142.1 KB
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/*
 *  linux/mm/page_alloc.c
 *
 *  Manages the free list, the system allocates free pages here.
 *  Note that kmalloc() lives in slab.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *  Swap reorganised 29.12.95, Stephen Tweedie
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *  Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
 *  Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
 *  Zone balancing, Kanoj Sarcar, SGI, Jan 2000
 *  Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
 *          (lots of bits borrowed from Ingo Molnar & Andrew Morton)
 */

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

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

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

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

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

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#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
int pageblock_order __read_mostly;
#endif

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

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

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int min_free_kbytes = 1024;

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

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

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

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int page_group_by_mobility_disabled __read_mostly;

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

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

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bool oom_killer_disabled __read_mostly;

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

	return ret;
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}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	return page + (buddy_idx - page_idx);
}

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

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

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

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

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

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

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

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

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

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

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

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

/*
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 * Frees a number of pages from the PCP lists
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 * Assumes all pages on list are in same zone, and of same order.
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 * count is the number of pages to free.
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 *
 * If the zone was previously in an "all pages pinned" state then look to
 * see if this freeing clears that state.
 *
 * And clear the zone's pages_scanned counter, to hold off the "all pages are
 * pinned" detection logic.
 */
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static void free_pcppages_bulk(struct zone *zone, int count,
					struct per_cpu_pages *pcp)
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{
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	int migratetype = 0;
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	int batch_free = 0;
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	spin_lock(&zone->lock);
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	zone->all_unreclaimable = 0;
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	zone->pages_scanned = 0;
560

561
	__mod_zone_page_state(zone, NR_FREE_PAGES, count);
562
	while (count) {
N
Nick Piggin 已提交
563
		struct page *page;
564 565 566
		struct list_head *list;

		/*
567 568 569 570 571
		 * 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
572 573
		 */
		do {
574
			batch_free++;
575 576 577 578
			if (++migratetype == MIGRATE_PCPTYPES)
				migratetype = 0;
			list = &pcp->lists[migratetype];
		} while (list_empty(list));
N
Nick Piggin 已提交
579

580 581 582 583
		do {
			page = list_entry(list->prev, struct page, lru);
			/* must delete as __free_one_page list manipulates */
			list_del(&page->lru);
584 585 586
			/* 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));
587
		} while (--count && --batch_free && !list_empty(list));
L
Linus Torvalds 已提交
588
	}
N
Nick Piggin 已提交
589
	spin_unlock(&zone->lock);
L
Linus Torvalds 已提交
590 591
}

592 593
static void free_one_page(struct zone *zone, struct page *page, int order,
				int migratetype)
L
Linus Torvalds 已提交
594
{
595
	spin_lock(&zone->lock);
596
	zone->all_unreclaimable = 0;
597
	zone->pages_scanned = 0;
598 599

	__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
600
	__free_one_page(page, zone, order, migratetype);
601
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
602 603 604 605 606
}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
L
Linus Torvalds 已提交
607
	int i;
608
	int bad = 0;
609
	int wasMlocked = __TestClearPageMlocked(page);
L
Linus Torvalds 已提交
610

611
	trace_mm_page_free_direct(page, order);
612 613
	kmemcheck_free_shadow(page, order);

L
Linus Torvalds 已提交
614
	for (i = 0 ; i < (1 << order) ; ++i)
615 616
		bad += free_pages_check(page + i);
	if (bad)
617 618
		return;

619
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
620
		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
621 622 623
		debug_check_no_obj_freed(page_address(page),
					   PAGE_SIZE << order);
	}
N
Nick Piggin 已提交
624
	arch_free_page(page, order);
N
Nick Piggin 已提交
625
	kernel_map_pages(page, 1 << order, 0);
N
Nick Piggin 已提交
626

N
Nick Piggin 已提交
627
	local_irq_save(flags);
628
	if (unlikely(wasMlocked))
629
		free_page_mlock(page);
630
	__count_vm_events(PGFREE, 1 << order);
631 632
	free_one_page(page_zone(page), page, order,
					get_pageblock_migratetype(page));
N
Nick Piggin 已提交
633
	local_irq_restore(flags);
L
Linus Torvalds 已提交
634 635
}

636 637 638
/*
 * permit the bootmem allocator to evade page validation on high-order frees
 */
639
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
640 641 642 643
{
	if (order == 0) {
		__ClearPageReserved(page);
		set_page_count(page, 0);
644
		set_page_refcounted(page);
N
Nick Piggin 已提交
645
		__free_page(page);
646 647 648
	} else {
		int loop;

N
Nick Piggin 已提交
649
		prefetchw(page);
650 651 652
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

N
Nick Piggin 已提交
653 654
			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
655 656 657 658
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

659
		set_page_refcounted(page);
N
Nick Piggin 已提交
660
		__free_pages(page, order);
661 662 663
	}
}

L
Linus Torvalds 已提交
664 665 666 667 668 669 670 671 672 673 674 675 676 677 678

/*
 * 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
679
static inline void expand(struct zone *zone, struct page *page,
680 681
	int low, int high, struct free_area *area,
	int migratetype)
L
Linus Torvalds 已提交
682 683 684 685 686 687 688
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
689
		VM_BUG_ON(bad_range(zone, &page[size]));
690
		list_add(&page[size].lru, &area->free_list[migratetype]);
L
Linus Torvalds 已提交
691 692 693 694 695 696 697 698
		area->nr_free++;
		set_page_order(&page[size], high);
	}
}

/*
 * This page is about to be returned from the page allocator
 */
699
static inline int check_new_page(struct page *page)
L
Linus Torvalds 已提交
700
{
N
Nick Piggin 已提交
701 702
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
703
		(atomic_read(&page->_count) != 0)  |
704
		(page->flags & PAGE_FLAGS_CHECK_AT_PREP))) {
N
Nick Piggin 已提交
705
		bad_page(page);
706
		return 1;
707
	}
708 709 710 711 712 713 714 715 716 717 718 719
	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;
	}
720

H
Hugh Dickins 已提交
721
	set_page_private(page, 0);
722
	set_page_refcounted(page);
N
Nick Piggin 已提交
723 724

	arch_alloc_page(page, order);
L
Linus Torvalds 已提交
725
	kernel_map_pages(page, 1 << order, 1);
N
Nick Piggin 已提交
726 727 728 729 730 731 732

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

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

733
	return 0;
L
Linus Torvalds 已提交
734 735
}

736 737 738 739
/*
 * Go through the free lists for the given migratetype and remove
 * the smallest available page from the freelists
 */
740 741
static inline
struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766
						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;
}


767 768 769 770 771
/*
 * 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] = {
772 773 774 775
	[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 */
776 777
};

778 779
/*
 * Move the free pages in a range to the free lists of the requested type.
780
 * Note that start_page and end_pages are not aligned on a pageblock
781 782
 * boundary. If alignment is required, use move_freepages_block()
 */
A
Adrian Bunk 已提交
783 784 785
static int move_freepages(struct zone *zone,
			  struct page *start_page, struct page *end_page,
			  int migratetype)
786 787 788
{
	struct page *page;
	unsigned long order;
789
	int pages_moved = 0;
790 791 792 793 794 795 796

#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
797
	 * grouping pages by mobility
798 799 800 801 802
	 */
	BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif

	for (page = start_page; page <= end_page;) {
803 804 805
		/* Make sure we are not inadvertently changing nodes */
		VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));

806 807 808 809 810 811 812 813 814 815 816 817 818 819 820
		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;
821
		pages_moved += 1 << order;
822 823
	}

824
	return pages_moved;
825 826
}

A
Adrian Bunk 已提交
827 828
static int move_freepages_block(struct zone *zone, struct page *page,
				int migratetype)
829 830 831 832 833
{
	unsigned long start_pfn, end_pfn;
	struct page *start_page, *end_page;

	start_pfn = page_to_pfn(page);
834
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
835
	start_page = pfn_to_page(start_pfn);
836 837
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
838 839 840 841 842 843 844 845 846 847

	/* 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);
}

848 849 850 851 852 853 854 855 856 857 858
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;
	}
}

859
/* Remove an element from the buddy allocator from the fallback list */
860 861
static inline struct page *
__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
862 863 864 865 866 867 868 869 870 871 872 873
{
	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];

874 875 876
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
				continue;
M
Mel Gorman 已提交
877

878 879 880 881 882 883 884 885 886
			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--;

			/*
887
			 * If breaking a large block of pages, move all free
888 889 890
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
			 * agressive about taking ownership of free pages
891
			 */
892
			if (unlikely(current_order >= (pageblock_order >> 1)) ||
893 894
					start_migratetype == MIGRATE_RECLAIMABLE ||
					page_group_by_mobility_disabled) {
895 896 897 898 899
				unsigned long pages;
				pages = move_freepages_block(zone, page,
								start_migratetype);

				/* Claim the whole block if over half of it is free */
900 901
				if (pages >= (1 << (pageblock_order-1)) ||
						page_group_by_mobility_disabled)
902 903 904
					set_pageblock_migratetype(page,
								start_migratetype);

905
				migratetype = start_migratetype;
906
			}
907 908 909 910 911

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

912 913 914
			/* Take ownership for orders >= pageblock_order */
			if (current_order >= pageblock_order)
				change_pageblock_range(page, current_order,
915 916 917
							start_migratetype);

			expand(zone, page, order, current_order, area, migratetype);
918 919 920 921

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

922 923 924 925
			return page;
		}
	}

926
	return NULL;
927 928
}

929
/*
L
Linus Torvalds 已提交
930 931 932
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
933 934
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
L
Linus Torvalds 已提交
935 936 937
{
	struct page *page;

938
retry_reserve:
939
	page = __rmqueue_smallest(zone, order, migratetype);
940

941
	if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
942
		page = __rmqueue_fallback(zone, order, migratetype);
943

944 945 946 947 948 949 950 951 952 953 954
		/*
		 * 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;
		}
	}

955
	trace_mm_page_alloc_zone_locked(page, order, migratetype);
956
	return page;
L
Linus Torvalds 已提交
957 958 959 960 961 962 963 964
}

/* 
 * 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, 
965
			unsigned long count, struct list_head *list,
966
			int migratetype, int cold)
L
Linus Torvalds 已提交
967 968 969
{
	int i;
	
N
Nick Piggin 已提交
970
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
971
	for (i = 0; i < count; ++i) {
972
		struct page *page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
973
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
974
			break;
975 976 977 978 979 980 981 982 983 984

		/*
		 * 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.
		 */
985 986 987 988
		if (likely(cold == 0))
			list_add(&page->lru, list);
		else
			list_add_tail(&page->lru, list);
989
		set_page_private(page, migratetype);
990
		list = &page->lru;
L
Linus Torvalds 已提交
991
	}
992
	__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
N
Nick Piggin 已提交
993
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
994
	return i;
L
Linus Torvalds 已提交
995 996
}

997
#ifdef CONFIG_NUMA
998
/*
999 1000 1001 1002
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
1003 1004
 * Note that this function must be called with the thread pinned to
 * a single processor.
1005
 */
1006
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1007 1008
{
	unsigned long flags;
1009
	int to_drain;
1010

1011 1012 1013 1014 1015
	local_irq_save(flags);
	if (pcp->count >= pcp->batch)
		to_drain = pcp->batch;
	else
		to_drain = pcp->count;
1016
	free_pcppages_bulk(zone, to_drain, pcp);
1017 1018
	pcp->count -= to_drain;
	local_irq_restore(flags);
1019 1020 1021
}
#endif

1022 1023 1024 1025 1026 1027 1028 1029
/*
 * 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
1030
{
N
Nick Piggin 已提交
1031
	unsigned long flags;
L
Linus Torvalds 已提交
1032 1033
	struct zone *zone;

1034
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
1035
		struct per_cpu_pageset *pset;
1036
		struct per_cpu_pages *pcp;
L
Linus Torvalds 已提交
1037

1038 1039
		local_irq_save(flags);
		pset = per_cpu_ptr(zone->pageset, cpu);
1040 1041

		pcp = &pset->pcp;
1042
		free_pcppages_bulk(zone, pcp->count, pcp);
1043 1044
		pcp->count = 0;
		local_irq_restore(flags);
L
Linus Torvalds 已提交
1045 1046 1047
	}
}

1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060
/*
 * 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)
{
1061
	on_each_cpu(drain_local_pages, NULL, 1);
1062 1063
}

1064
#ifdef CONFIG_HIBERNATION
L
Linus Torvalds 已提交
1065 1066 1067

void mark_free_pages(struct zone *zone)
{
1068 1069
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
1070
	int order, t;
L
Linus Torvalds 已提交
1071 1072 1073 1074 1075 1076
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
1077 1078 1079 1080 1081 1082

	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);

1083 1084
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
1085
		}
L
Linus Torvalds 已提交
1086

1087 1088
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
1089
			unsigned long i;
L
Linus Torvalds 已提交
1090

1091 1092
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
1093
				swsusp_set_page_free(pfn_to_page(pfn + i));
1094
		}
1095
	}
L
Linus Torvalds 已提交
1096 1097
	spin_unlock_irqrestore(&zone->lock, flags);
}
1098
#endif /* CONFIG_PM */
L
Linus Torvalds 已提交
1099 1100 1101

/*
 * Free a 0-order page
L
Li Hong 已提交
1102
 * cold == 1 ? free a cold page : free a hot page
L
Linus Torvalds 已提交
1103
 */
L
Li Hong 已提交
1104
void free_hot_cold_page(struct page *page, int cold)
L
Linus Torvalds 已提交
1105 1106 1107 1108
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;
1109
	int migratetype;
1110
	int wasMlocked = __TestClearPageMlocked(page);
L
Linus Torvalds 已提交
1111

1112
	trace_mm_page_free_direct(page, 0);
1113 1114
	kmemcheck_free_shadow(page, 0);

L
Linus Torvalds 已提交
1115 1116
	if (PageAnon(page))
		page->mapping = NULL;
N
Nick Piggin 已提交
1117
	if (free_pages_check(page))
1118 1119
		return;

1120
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
1121
		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
1122 1123
		debug_check_no_obj_freed(page_address(page), PAGE_SIZE);
	}
N
Nick Piggin 已提交
1124
	arch_free_page(page, 0);
1125 1126
	kernel_map_pages(page, 1, 0);

1127 1128
	migratetype = get_pageblock_migratetype(page);
	set_page_private(page, migratetype);
L
Linus Torvalds 已提交
1129
	local_irq_save(flags);
1130
	if (unlikely(wasMlocked))
1131
		free_page_mlock(page);
1132
	__count_vm_event(PGFREE);
1133

1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148
	/*
	 * 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;
	}

1149
	pcp = &this_cpu_ptr(zone->pageset)->pcp;
1150
	if (cold)
1151
		list_add_tail(&page->lru, &pcp->lists[migratetype]);
1152
	else
1153
		list_add(&page->lru, &pcp->lists[migratetype]);
L
Linus Torvalds 已提交
1154
	pcp->count++;
N
Nick Piggin 已提交
1155
	if (pcp->count >= pcp->high) {
1156
		free_pcppages_bulk(zone, pcp->batch, pcp);
N
Nick Piggin 已提交
1157 1158
		pcp->count -= pcp->batch;
	}
1159 1160

out:
L
Linus Torvalds 已提交
1161 1162 1163
	local_irq_restore(flags);
}

N
Nick Piggin 已提交
1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175
/*
 * 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
1176 1177
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1178 1179 1180 1181 1182 1183 1184 1185 1186 1187

#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

1188 1189
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
1190 1191
}

L
Linus Torvalds 已提交
1192 1193 1194 1195 1196
/*
 * 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.
 */
1197 1198
static inline
struct page *buffered_rmqueue(struct zone *preferred_zone,
1199 1200
			struct zone *zone, int order, gfp_t gfp_flags,
			int migratetype)
L
Linus Torvalds 已提交
1201 1202
{
	unsigned long flags;
1203
	struct page *page;
L
Linus Torvalds 已提交
1204 1205
	int cold = !!(gfp_flags & __GFP_COLD);

1206
again:
N
Nick Piggin 已提交
1207
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1208
		struct per_cpu_pages *pcp;
1209
		struct list_head *list;
L
Linus Torvalds 已提交
1210 1211

		local_irq_save(flags);
1212 1213
		pcp = &this_cpu_ptr(zone->pageset)->pcp;
		list = &pcp->lists[migratetype];
1214
		if (list_empty(list)) {
1215
			pcp->count += rmqueue_bulk(zone, 0,
1216
					pcp->batch, list,
1217
					migratetype, cold);
1218
			if (unlikely(list_empty(list)))
1219
				goto failed;
1220
		}
1221

1222 1223 1224 1225 1226
		if (cold)
			page = list_entry(list->prev, struct page, lru);
		else
			page = list_entry(list->next, struct page, lru);

1227 1228
		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1229
	} else {
1230 1231 1232 1233 1234 1235 1236 1237
		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
1238
			 * allocate greater than order-1 page units with
1239 1240
			 * __GFP_NOFAIL.
			 */
1241
			WARN_ON_ONCE(order > 1);
1242
		}
L
Linus Torvalds 已提交
1243
		spin_lock_irqsave(&zone->lock, flags);
1244
		page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1245 1246 1247
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
1248
		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
L
Linus Torvalds 已提交
1249 1250
	}

1251
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1252
	zone_statistics(preferred_zone, zone);
N
Nick Piggin 已提交
1253
	local_irq_restore(flags);
L
Linus Torvalds 已提交
1254

N
Nick Piggin 已提交
1255
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1256
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1257
		goto again;
L
Linus Torvalds 已提交
1258
	return page;
N
Nick Piggin 已提交
1259 1260 1261 1262

failed:
	local_irq_restore(flags);
	return NULL;
L
Linus Torvalds 已提交
1263 1264
}

1265 1266 1267 1268 1269 1270 1271 1272 1273
/* 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)

1274 1275 1276
#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
1277

1278 1279 1280 1281 1282 1283 1284
#ifdef CONFIG_FAIL_PAGE_ALLOC

static struct fail_page_alloc_attr {
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1285
	u32 min_order;
1286 1287 1288 1289 1290

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

	struct dentry *ignore_gfp_highmem_file;
	struct dentry *ignore_gfp_wait_file;
1291
	struct dentry *min_order_file;
1292 1293 1294 1295 1296

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1297 1298
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1299
	.min_order = 1,
1300 1301 1302 1303 1304 1305 1306 1307 1308 1309
};

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)
{
1310 1311
	if (order < fail_page_alloc.min_order)
		return 0;
1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342
	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);
1343 1344 1345
	fail_page_alloc.min_order_file =
		debugfs_create_u32("min-order", mode, dir,
				   &fail_page_alloc.min_order);
1346 1347

	if (!fail_page_alloc.ignore_gfp_wait_file ||
1348 1349
            !fail_page_alloc.ignore_gfp_highmem_file ||
            !fail_page_alloc.min_order_file) {
1350 1351 1352
		err = -ENOMEM;
		debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
		debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1353
		debugfs_remove(fail_page_alloc.min_order_file);
1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372
		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
1373 1374 1375 1376 1377
/*
 * Return 1 if free pages are above 'mark'. This takes into account the order
 * of the allocation.
 */
int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
R
Rohit Seth 已提交
1378
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
1379 1380
{
	/* free_pages my go negative - that's OK */
1381 1382
	long min = mark;
	long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
L
Linus Torvalds 已提交
1383 1384
	int o;

R
Rohit Seth 已提交
1385
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1386
		min -= min / 2;
R
Rohit Seth 已提交
1387
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404
		min -= min / 4;

	if (free_pages <= min + z->lowmem_reserve[classzone_idx])
		return 0;
	for (o = 0; o < order; o++) {
		/* At the next order, this order's pages become unavailable */
		free_pages -= z->free_area[o].nr_free << o;

		/* Require fewer higher order pages to be free */
		min >>= 1;

		if (free_pages <= min)
			return 0;
	}
	return 1;
}

1405 1406 1407 1408 1409 1410
#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
1411
 * that have to skip over a lot of full or unallowed zones.
1412 1413 1414
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1415
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436
 *
 * 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
1437
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1438 1439 1440 1441 1442 1443
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1444
					&node_states[N_HIGH_MEMORY];
1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469
	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.
 */
1470
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1471 1472 1473 1474 1475 1476 1477 1478 1479 1480
						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;

1481
	i = z - zonelist->_zonerefs;
1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492
	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.
 */
1493
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1494 1495 1496 1497 1498 1499 1500 1501
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

1502
	i = z - zonelist->_zonerefs;
1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

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

1514
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1515 1516 1517 1518 1519
				nodemask_t *allowednodes)
{
	return 1;
}

1520
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1521 1522 1523 1524
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1525
/*
1526
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1527 1528 1529
 * a page.
 */
static struct page *
1530
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1531
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1532
		struct zone *preferred_zone, int migratetype)
M
Martin Hicks 已提交
1533
{
1534
	struct zoneref *z;
R
Rohit Seth 已提交
1535
	struct page *page = NULL;
1536
	int classzone_idx;
1537
	struct zone *zone;
1538 1539 1540
	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 */
1541

1542
	classzone_idx = zone_idx(preferred_zone);
1543
zonelist_scan:
R
Rohit Seth 已提交
1544
	/*
1545
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1546 1547
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1548 1549
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1550 1551 1552
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1553
		if ((alloc_flags & ALLOC_CPUSET) &&
1554
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1555
				goto try_next_zone;
R
Rohit Seth 已提交
1556

1557
		BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
R
Rohit Seth 已提交
1558
		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1559
			unsigned long mark;
1560 1561
			int ret;

1562
			mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581
			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))
1582
					goto this_zone_full;
1583
			}
R
Rohit Seth 已提交
1584 1585
		}

1586
try_this_zone:
1587 1588
		page = buffered_rmqueue(preferred_zone, zone, order,
						gfp_mask, migratetype);
1589
		if (page)
R
Rohit Seth 已提交
1590
			break;
1591 1592 1593 1594
this_zone_full:
		if (NUMA_BUILD)
			zlc_mark_zone_full(zonelist, z);
try_next_zone:
1595
		if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
1596 1597 1598 1599
			/*
			 * we do zlc_setup after the first zone is tried but only
			 * if there are multiple nodes make it worthwhile
			 */
1600 1601 1602 1603
			allowednodes = zlc_setup(zonelist, alloc_flags);
			zlc_active = 1;
			did_zlc_setup = 1;
		}
1604
	}
1605 1606 1607 1608 1609 1610

	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
1611
	return page;
M
Martin Hicks 已提交
1612 1613
}

1614 1615 1616
static inline int
should_alloc_retry(gfp_t gfp_mask, unsigned int order,
				unsigned long pages_reclaimed)
L
Linus Torvalds 已提交
1617
{
1618 1619 1620
	/* Do not loop if specifically requested */
	if (gfp_mask & __GFP_NORETRY)
		return 0;
L
Linus Torvalds 已提交
1621

1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638
	/*
	 * 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;
1639

1640 1641 1642 1643 1644 1645
	/*
	 * 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
1646

1647 1648
	return 0;
}
1649

1650 1651 1652
static inline struct page *
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1653 1654
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1655 1656 1657 1658 1659 1660
{
	struct page *page;

	/* Acquire the OOM killer lock for the zones in zonelist */
	if (!try_set_zone_oom(zonelist, gfp_mask)) {
		schedule_timeout_uninterruptible(1);
L
Linus Torvalds 已提交
1661 1662
		return NULL;
	}
1663

1664 1665 1666 1667 1668 1669 1670
	/*
	 * 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,
1671
		ALLOC_WMARK_HIGH|ALLOC_CPUSET,
1672
		preferred_zone, migratetype);
R
Rohit Seth 已提交
1673
	if (page)
1674 1675
		goto out;

1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689
	if (!(gfp_mask & __GFP_NOFAIL)) {
		/* The OOM killer will not help higher order allocs */
		if (order > PAGE_ALLOC_COSTLY_ORDER)
			goto out;
		/*
		 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
		 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
		 * The caller should handle page allocation failure by itself if
		 * it specifies __GFP_THISNODE.
		 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
		 */
		if (gfp_mask & __GFP_THISNODE)
			goto out;
	}
1690
	/* Exhausted what can be done so it's blamo time */
1691
	out_of_memory(zonelist, gfp_mask, order, nodemask);
1692 1693 1694 1695 1696 1697 1698 1699 1700 1701

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

/* The really slow allocator path where we enter direct reclaim */
static inline struct page *
__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1702
	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
1703
	int migratetype, unsigned long *did_some_progress)
1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730
{
	struct page *page = NULL;
	struct reclaim_state reclaim_state;
	struct task_struct *p = current;

	cond_resched();

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

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

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

	cond_resched();

	if (order != 0)
		drain_all_pages();

	if (likely(*did_some_progress))
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1731
					zonelist, high_zoneidx,
1732 1733
					alloc_flags, preferred_zone,
					migratetype);
1734 1735 1736
	return page;
}

L
Linus Torvalds 已提交
1737
/*
1738 1739
 * 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
1740
 */
1741 1742 1743
static inline struct page *
__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1744 1745
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1746 1747 1748 1749 1750
{
	struct page *page;

	do {
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1751
			zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
1752
			preferred_zone, migratetype);
1753 1754

		if (!page && gfp_mask & __GFP_NOFAIL)
1755
			congestion_wait(BLK_RW_ASYNC, HZ/50);
1756 1757 1758 1759 1760 1761 1762 1763
	} while (!page && (gfp_mask & __GFP_NOFAIL));

	return page;
}

static inline
void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
						enum zone_type high_zoneidx)
L
Linus Torvalds 已提交
1764
{
1765 1766
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
1767

1768 1769 1770
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
		wakeup_kswapd(zone, order);
}
1771

1772 1773 1774 1775 1776 1777
static inline int
gfp_to_alloc_flags(gfp_t gfp_mask)
{
	struct task_struct *p = current;
	int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
	const gfp_t wait = gfp_mask & __GFP_WAIT;
L
Linus Torvalds 已提交
1778

1779 1780
	/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
	BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH);
1781

1782 1783 1784 1785 1786 1787
	/*
	 * 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).
	 */
1788
	alloc_flags |= (gfp_mask & __GFP_HIGH);
L
Linus Torvalds 已提交
1789

1790 1791
	if (!wait) {
		alloc_flags |= ALLOC_HARDER;
1792
		/*
1793 1794
		 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
		 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
1795
		 */
1796
		alloc_flags &= ~ALLOC_CPUSET;
1797
	} else if (unlikely(rt_task(p)) && !in_interrupt())
1798 1799 1800 1801 1802 1803 1804
		alloc_flags |= ALLOC_HARDER;

	if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
		if (!in_interrupt() &&
		    ((p->flags & PF_MEMALLOC) ||
		     unlikely(test_thread_flag(TIF_MEMDIE))))
			alloc_flags |= ALLOC_NO_WATERMARKS;
L
Linus Torvalds 已提交
1805
	}
1806

1807 1808 1809
	return alloc_flags;
}

1810 1811 1812
static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
1813 1814
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
1815 1816 1817 1818 1819 1820 1821
{
	const gfp_t wait = gfp_mask & __GFP_WAIT;
	struct page *page = NULL;
	int alloc_flags;
	unsigned long pages_reclaimed = 0;
	unsigned long did_some_progress;
	struct task_struct *p = current;
L
Linus Torvalds 已提交
1822

1823 1824 1825 1826 1827 1828
	/*
	 * 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.
	 */
1829 1830
	if (order >= MAX_ORDER) {
		WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
1831
		return NULL;
1832
	}
L
Linus Torvalds 已提交
1833

1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844
	/*
	 * 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;

1845
restart:
1846
	wake_all_kswapd(order, zonelist, high_zoneidx);
L
Linus Torvalds 已提交
1847

1848
	/*
R
Rohit Seth 已提交
1849 1850 1851
	 * 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.
1852
	 */
1853
	alloc_flags = gfp_to_alloc_flags(gfp_mask);
L
Linus Torvalds 已提交
1854

1855
	/* This is the last chance, in general, before the goto nopage. */
1856
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1857 1858
			high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
			preferred_zone, migratetype);
R
Rohit Seth 已提交
1859 1860
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1861

1862
rebalance:
1863
	/* Allocate without watermarks if the context allows */
1864 1865 1866 1867 1868 1869
	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
1870 1871 1872 1873 1874 1875
	}

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

1876 1877 1878 1879
	/* Avoid recursion of direct reclaim */
	if (p->flags & PF_MEMALLOC)
		goto nopage;

1880 1881 1882 1883
	/* Avoid allocations with no watermarks from looping endlessly */
	if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
		goto nopage;

1884 1885 1886 1887
	/* Try direct reclaim and then allocating */
	page = __alloc_pages_direct_reclaim(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
1888
					alloc_flags, preferred_zone,
1889
					migratetype, &did_some_progress);
1890 1891
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1892

1893
	/*
1894 1895
	 * If we failed to make any progress reclaiming, then we are
	 * running out of options and have to consider going OOM
1896
	 */
1897 1898
	if (!did_some_progress) {
		if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1899 1900
			if (oom_killer_disabled)
				goto nopage;
1901 1902
			page = __alloc_pages_may_oom(gfp_mask, order,
					zonelist, high_zoneidx,
1903 1904
					nodemask, preferred_zone,
					migratetype);
1905 1906
			if (page)
				goto got_pg;
L
Linus Torvalds 已提交
1907

1908
			/*
1909 1910 1911 1912
			 * The OOM killer does not trigger for high-order
			 * ~__GFP_NOFAIL allocations so if no progress is being
			 * made, there are no other options and retrying is
			 * unlikely to help.
1913
			 */
1914 1915
			if (order > PAGE_ALLOC_COSTLY_ORDER &&
						!(gfp_mask & __GFP_NOFAIL))
1916
				goto nopage;
1917

1918 1919
			goto restart;
		}
L
Linus Torvalds 已提交
1920 1921
	}

1922
	/* Check if we should retry the allocation */
1923
	pages_reclaimed += did_some_progress;
1924 1925
	if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
		/* Wait for some write requests to complete then retry */
1926
		congestion_wait(BLK_RW_ASYNC, HZ/50);
L
Linus Torvalds 已提交
1927 1928 1929 1930 1931 1932 1933 1934 1935
		goto rebalance;
	}

nopage:
	if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
		printk(KERN_WARNING "%s: page allocation failure."
			" order:%d, mode:0x%x\n",
			p->comm, order, gfp_mask);
		dump_stack();
J
Janet Morgan 已提交
1936
		show_mem();
L
Linus Torvalds 已提交
1937
	}
1938
	return page;
L
Linus Torvalds 已提交
1939
got_pg:
1940 1941
	if (kmemcheck_enabled)
		kmemcheck_pagealloc_alloc(page, order, gfp_mask);
L
Linus Torvalds 已提交
1942
	return page;
1943

L
Linus Torvalds 已提交
1944
}
1945 1946 1947 1948 1949 1950 1951 1952 1953

/*
 * 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);
1954
	struct zone *preferred_zone;
1955
	struct page *page;
1956
	int migratetype = allocflags_to_migratetype(gfp_mask);
1957

1958 1959
	gfp_mask &= gfp_allowed_mask;

1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974
	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;

1975 1976 1977 1978 1979 1980
	/* The preferred zone is used for statistics later */
	first_zones_zonelist(zonelist, high_zoneidx, nodemask, &preferred_zone);
	if (!preferred_zone)
		return NULL;

	/* First allocation attempt */
1981
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
1982
			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
1983
			preferred_zone, migratetype);
1984 1985
	if (unlikely(!page))
		page = __alloc_pages_slowpath(gfp_mask, order,
1986
				zonelist, high_zoneidx, nodemask,
1987
				preferred_zone, migratetype);
1988

1989
	trace_mm_page_alloc(page, order, gfp_mask, migratetype);
1990
	return page;
L
Linus Torvalds 已提交
1991
}
1992
EXPORT_SYMBOL(__alloc_pages_nodemask);
L
Linus Torvalds 已提交
1993 1994 1995 1996

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
1997
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
1998
{
1999 2000 2001 2002 2003 2004 2005 2006
	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
2007 2008 2009 2010 2011 2012 2013
	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
2014
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
2015
{
2016
	return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
L
Linus Torvalds 已提交
2017 2018 2019 2020 2021 2022 2023
}
EXPORT_SYMBOL(get_zeroed_page);

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

2024 2025
	while (--i >= 0) {
		trace_mm_pagevec_free(pvec->pages[i], pvec->cold);
L
Linus Torvalds 已提交
2026
		free_hot_cold_page(pvec->pages[i], pvec->cold);
2027
	}
L
Linus Torvalds 已提交
2028 2029
}

H
Harvey Harrison 已提交
2030
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
2031
{
N
Nick Piggin 已提交
2032
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
2033
		if (order == 0)
L
Li Hong 已提交
2034
			free_hot_cold_page(page, 0);
L
Linus Torvalds 已提交
2035 2036 2037 2038 2039 2040 2041
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
2042
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
2043 2044
{
	if (addr != 0) {
N
Nick Piggin 已提交
2045
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
2046 2047 2048 2049 2050 2051
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074
/**
 * 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
2075
		split_page(virt_to_page((void *)addr), order);
2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104
		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
2105 2106
static unsigned int nr_free_zone_pages(int offset)
{
2107
	struct zoneref *z;
2108 2109
	struct zone *zone;

2110
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
2111 2112
	unsigned int sum = 0;

2113
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
2114

2115
	for_each_zone_zonelist(zone, z, zonelist, offset) {
2116
		unsigned long size = zone->present_pages;
2117
		unsigned long high = high_wmark_pages(zone);
2118 2119
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
2120 2121 2122 2123 2124 2125 2126 2127 2128 2129
	}

	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
2130
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
2131
}
2132
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
2133 2134 2135 2136 2137 2138

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
2139
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
2140
}
2141 2142

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
2143
{
2144
	if (NUMA_BUILD)
2145
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
2146 2147 2148 2149 2150 2151
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
2152
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166
	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;
2167
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
2168
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2169
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2170 2171
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
2172 2173 2174 2175
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188
	val->mem_unit = PAGE_SIZE;
}
#endif

#define K(x) ((x) << (PAGE_SHIFT-10))

/*
 * Show free area list (used inside shift_scroll-lock stuff)
 * We also calculate the percentage fragmentation. We do this by counting the
 * memory on each free list with the exception of the first item on the list.
 */
void show_free_areas(void)
{
2189
	int cpu;
L
Linus Torvalds 已提交
2190 2191
	struct zone *zone;

2192
	for_each_populated_zone(zone) {
2193 2194
		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
2195

2196
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
2197 2198
			struct per_cpu_pageset *pageset;

2199
			pageset = per_cpu_ptr(zone->pageset, cpu);
L
Linus Torvalds 已提交
2200

2201 2202 2203
			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
2204 2205 2206
		}
	}

K
KOSAKI Motohiro 已提交
2207 2208
	printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
		" active_file:%lu inactive_file:%lu isolated_file:%lu\n"
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2209
		" unevictable:%lu"
2210
		" dirty:%lu writeback:%lu unstable:%lu\n"
2211
		" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2212
		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
2213 2214
		global_page_state(NR_ACTIVE_ANON),
		global_page_state(NR_INACTIVE_ANON),
K
KOSAKI Motohiro 已提交
2215 2216
		global_page_state(NR_ISOLATED_ANON),
		global_page_state(NR_ACTIVE_FILE),
2217
		global_page_state(NR_INACTIVE_FILE),
K
KOSAKI Motohiro 已提交
2218
		global_page_state(NR_ISOLATED_FILE),
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2219
		global_page_state(NR_UNEVICTABLE),
2220
		global_page_state(NR_FILE_DIRTY),
2221
		global_page_state(NR_WRITEBACK),
2222
		global_page_state(NR_UNSTABLE_NFS),
2223
		global_page_state(NR_FREE_PAGES),
2224 2225
		global_page_state(NR_SLAB_RECLAIMABLE),
		global_page_state(NR_SLAB_UNRECLAIMABLE),
2226
		global_page_state(NR_FILE_MAPPED),
2227
		global_page_state(NR_SHMEM),
2228 2229
		global_page_state(NR_PAGETABLE),
		global_page_state(NR_BOUNCE));
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2230

2231
	for_each_populated_zone(zone) {
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2232 2233 2234 2235 2236 2237 2238 2239
		int i;

		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
2240 2241 2242 2243
			" active_anon:%lukB"
			" inactive_anon:%lukB"
			" active_file:%lukB"
			" inactive_file:%lukB"
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2244
			" unevictable:%lukB"
K
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2245 2246
			" isolated(anon):%lukB"
			" isolated(file):%lukB"
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2247
			" present:%lukB"
2248 2249 2250 2251
			" mlocked:%lukB"
			" dirty:%lukB"
			" writeback:%lukB"
			" mapped:%lukB"
2252
			" shmem:%lukB"
2253 2254
			" slab_reclaimable:%lukB"
			" slab_unreclaimable:%lukB"
2255
			" kernel_stack:%lukB"
2256 2257 2258 2259
			" pagetables:%lukB"
			" unstable:%lukB"
			" bounce:%lukB"
			" writeback_tmp:%lukB"
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2260 2261 2262 2263
			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
2264
			K(zone_page_state(zone, NR_FREE_PAGES)),
2265 2266 2267
			K(min_wmark_pages(zone)),
			K(low_wmark_pages(zone)),
			K(high_wmark_pages(zone)),
2268 2269 2270 2271
			K(zone_page_state(zone, NR_ACTIVE_ANON)),
			K(zone_page_state(zone, NR_INACTIVE_ANON)),
			K(zone_page_state(zone, NR_ACTIVE_FILE)),
			K(zone_page_state(zone, NR_INACTIVE_FILE)),
L
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2272
			K(zone_page_state(zone, NR_UNEVICTABLE)),
K
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2273 2274
			K(zone_page_state(zone, NR_ISOLATED_ANON)),
			K(zone_page_state(zone, NR_ISOLATED_FILE)),
L
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2275
			K(zone->present_pages),
2276 2277 2278 2279
			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)),
2280
			K(zone_page_state(zone, NR_SHMEM)),
2281 2282
			K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
			K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
2283 2284
			zone_page_state(zone, NR_KERNEL_STACK) *
				THREAD_SIZE / 1024,
2285 2286 2287 2288
			K(zone_page_state(zone, NR_PAGETABLE)),
			K(zone_page_state(zone, NR_UNSTABLE_NFS)),
			K(zone_page_state(zone, NR_BOUNCE)),
			K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
L
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2289
			zone->pages_scanned,
2290
			(zone->all_unreclaimable ? "yes" : "no")
L
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2291 2292 2293 2294 2295 2296 2297
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

2298
	for_each_populated_zone(zone) {
2299
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
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2300 2301 2302 2303 2304 2305

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

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
2306 2307
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
L
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2308 2309
		}
		spin_unlock_irqrestore(&zone->lock, flags);
2310 2311
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
L
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2312 2313 2314
		printk("= %lukB\n", K(total));
	}

2315 2316
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

L
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2317 2318 2319
	show_swap_cache_info();
}

2320 2321 2322 2323 2324 2325
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
{
	zoneref->zone = zone;
	zoneref->zone_idx = zone_idx(zone);
}

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2326 2327
/*
 * Builds allocation fallback zone lists.
2328 2329
 *
 * Add all populated zones of a node to the zonelist.
L
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2330
 */
2331 2332
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
2333
{
2334 2335
	struct zone *zone;

2336
	BUG_ON(zone_type >= MAX_NR_ZONES);
2337
	zone_type++;
2338 2339

	do {
2340
		zone_type--;
2341
		zone = pgdat->node_zones + zone_type;
2342
		if (populated_zone(zone)) {
2343 2344
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
2345
			check_highest_zone(zone_type);
L
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2346
		}
2347

2348
	} while (zone_type);
2349
	return nr_zones;
L
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2350 2351
}

2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372

/*
 *  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
2373
#ifdef CONFIG_NUMA
2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416
/* The value user specified ....changed by config */
static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
/* string for sysctl */
#define NUMA_ZONELIST_ORDER_LEN	16
char numa_zonelist_order[16] = "default";

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

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

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

/*
 * sysctl handler for numa_zonelist_order
 */
int numa_zonelist_order_handler(ctl_table *table, int write,
2417
		void __user *buffer, size_t *length,
2418 2419 2420 2421
		loff_t *ppos)
{
	char saved_string[NUMA_ZONELIST_ORDER_LEN];
	int ret;
2422
	static DEFINE_MUTEX(zl_order_mutex);
2423

2424
	mutex_lock(&zl_order_mutex);
2425
	if (write)
2426
		strcpy(saved_string, (char*)table->data);
2427
	ret = proc_dostring(table, write, buffer, length, ppos);
2428
	if (ret)
2429
		goto out;
2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441
	if (write) {
		int oldval = user_zonelist_order;
		if (__parse_numa_zonelist_order((char*)table->data)) {
			/*
			 * bogus value.  restore saved string
			 */
			strncpy((char*)table->data, saved_string,
				NUMA_ZONELIST_ORDER_LEN);
			user_zonelist_order = oldval;
		} else if (oldval != user_zonelist_order)
			build_all_zonelists();
	}
2442 2443 2444
out:
	mutex_unlock(&zl_order_mutex);
	return ret;
2445 2446 2447
}


2448
#define MAX_NODE_LOAD (nr_online_nodes)
2449 2450
static int node_load[MAX_NUMNODES];

L
Linus Torvalds 已提交
2451
/**
2452
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
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2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464
 * @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.
 */
2465
static int find_next_best_node(int node, nodemask_t *used_node_mask)
L
Linus Torvalds 已提交
2466
{
2467
	int n, val;
L
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2468 2469
	int min_val = INT_MAX;
	int best_node = -1;
2470
	const struct cpumask *tmp = cpumask_of_node(0);
L
Linus Torvalds 已提交
2471

2472 2473 2474 2475 2476
	/* 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
2477

2478
	for_each_node_state(n, N_HIGH_MEMORY) {
L
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2479 2480 2481 2482 2483 2484 2485 2486

		/* 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);

2487 2488 2489
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
Linus Torvalds 已提交
2490
		/* Give preference to headless and unused nodes */
2491 2492
		tmp = cpumask_of_node(n);
		if (!cpumask_empty(tmp))
L
Linus Torvalds 已提交
2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510
			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;
}

2511 2512 2513 2514 2515 2516 2517

/*
 * 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
2518
{
2519
	int j;
L
Linus Torvalds 已提交
2520
	struct zonelist *zonelist;
2521

2522
	zonelist = &pgdat->node_zonelists[0];
2523
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2524 2525 2526
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
2527 2528
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2529 2530
}

2531 2532 2533 2534 2535 2536 2537 2538
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

2539 2540
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2541 2542
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2543 2544
}

2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559
/*
 * 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;

2560 2561 2562 2563 2564 2565 2566
	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)) {
2567 2568
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
2569
				check_highest_zone(zone_type);
2570 2571 2572
			}
		}
	}
2573 2574
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609
}

static int default_zonelist_order(void)
{
	int nid, zone_type;
	unsigned long low_kmem_size,total_size;
	struct zone *z;
	int average_size;
	/*
         * ZONE_DMA and ZONE_DMA32 can be very small area in the sytem.
	 * If they are really small and used heavily, the system can fall
	 * into OOM very easily.
	 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
	 */
	/* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
	low_kmem_size = 0;
	total_size = 0;
	for_each_online_node(nid) {
		for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
			z = &NODE_DATA(nid)->node_zones[zone_type];
			if (populated_zone(z)) {
				if (zone_type < ZONE_NORMAL)
					low_kmem_size += z->present_pages;
				total_size += z->present_pages;
			}
		}
	}
	if (!low_kmem_size ||  /* there are no DMA area. */
	    low_kmem_size > total_size/2) /* DMA/DMA32 is big. */
		return ZONELIST_ORDER_NODE;
	/*
	 * look into each node's config.
  	 * If there is a node whose DMA/DMA32 memory is very big area on
 	 * local memory, NODE_ORDER may be suitable.
         */
2610 2611
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642
	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
2643
	nodemask_t used_mask;
2644 2645 2646
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
L
Linus Torvalds 已提交
2647 2648

	/* initialize zonelists */
2649
	for (i = 0; i < MAX_ZONELISTS; i++) {
L
Linus Torvalds 已提交
2650
		zonelist = pgdat->node_zonelists + i;
2651 2652
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
L
Linus Torvalds 已提交
2653 2654 2655 2656
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
2657
	load = nr_online_nodes;
L
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2658 2659
	prev_node = local_node;
	nodes_clear(used_mask);
2660 2661 2662 2663

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

L
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2664
	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2665 2666 2667 2668 2669 2670 2671 2672 2673
		int distance = node_distance(local_node, node);

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

L
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2674 2675 2676 2677 2678
		/*
		 * 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.
		 */
2679
		if (distance != node_distance(local_node, prev_node))
2680 2681
			node_load[node] = load;

L
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2682 2683
		prev_node = node;
		load--;
2684 2685 2686 2687 2688
		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
2689

2690 2691 2692
	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
2693
	}
2694 2695

	build_thisnode_zonelists(pgdat);
L
Linus Torvalds 已提交
2696 2697
}

2698
/* Construct the zonelist performance cache - see further mmzone.h */
2699
static void build_zonelist_cache(pg_data_t *pgdat)
2700
{
2701 2702
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
2703
	struct zoneref *z;
2704

2705 2706 2707
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2708 2709
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2710 2711
}

2712

L
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2713 2714
#else	/* CONFIG_NUMA */

2715 2716 2717 2718 2719 2720
static void set_zonelist_order(void)
{
	current_zonelist_order = ZONELIST_ORDER_ZONE;
}

static void build_zonelists(pg_data_t *pgdat)
L
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2721
{
2722
	int node, local_node;
2723 2724
	enum zone_type j;
	struct zonelist *zonelist;
L
Linus Torvalds 已提交
2725 2726 2727

	local_node = pgdat->node_id;

2728 2729
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
2730

2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743
	/*
	 * 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
2744
	}
2745 2746 2747 2748 2749 2750 2751
	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);
	}

2752 2753
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
L
Linus Torvalds 已提交
2754 2755
}

2756
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2757
static void build_zonelist_cache(pg_data_t *pgdat)
2758
{
2759
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
2760 2761
}

L
Linus Torvalds 已提交
2762 2763
#endif	/* CONFIG_NUMA */

2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781
/*
 * 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);

2782
/* return values int ....just for stop_machine() */
2783
static int __build_all_zonelists(void *dummy)
L
Linus Torvalds 已提交
2784
{
2785
	int nid;
2786
	int cpu;
2787

2788 2789 2790
#ifdef CONFIG_NUMA
	memset(node_load, 0, sizeof(node_load));
#endif
2791
	for_each_online_node(nid) {
2792 2793 2794 2795
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
2796
	}
2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813

	/*
	 * 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).
	 */
	for_each_possible_cpu(cpu)
		setup_pageset(&per_cpu(boot_pageset, cpu), 0);

2814 2815 2816
	return 0;
}

2817
void build_all_zonelists(void)
2818
{
2819 2820
	set_zonelist_order();

2821
	if (system_state == SYSTEM_BOOTING) {
2822
		__build_all_zonelists(NULL);
2823
		mminit_verify_zonelist();
2824 2825
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
2826
		/* we have to stop all cpus to guarantee there is no user
2827
		   of zonelist */
2828
		stop_machine(__build_all_zonelists, NULL, NULL);
2829 2830
		/* cpuset refresh routine should be here */
	}
2831
	vm_total_pages = nr_free_pagecache_pages();
2832 2833 2834 2835 2836 2837 2838
	/*
	 * 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
	 */
2839
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2840 2841 2842 2843 2844 2845
		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",
2846
			nr_online_nodes,
2847
			zonelist_order_name[current_zonelist_order],
2848
			page_group_by_mobility_disabled ? "off" : "on",
2849 2850 2851 2852
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
L
Linus Torvalds 已提交
2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867
}

/*
 * 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

2868
#ifndef CONFIG_MEMORY_HOTPLUG
2869
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886
{
	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);
}
2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909
#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
2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922

/*
 * 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))

2923
/*
2924
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2925 2926
 * 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
2927 2928 2929 2930 2931 2932 2933
 * 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;
2934 2935
	unsigned long block_migratetype;
	int reserve;
2936 2937 2938 2939

	/* 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;
2940
	reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
2941
							pageblock_order;
2942

2943 2944 2945 2946 2947 2948 2949 2950 2951
	/*
	 * 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);

2952
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2953 2954 2955 2956
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

2957 2958 2959 2960
		/* Watch out for overlapping nodes */
		if (page_to_nid(page) != zone_to_nid(zone))
			continue;

2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990
		/* 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
2991

L
Linus Torvalds 已提交
2992 2993 2994 2995 2996
/*
 * 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.
 */
2997
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
2998
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
2999 3000
{
	struct page *page;
A
Andy Whitcroft 已提交
3001 3002
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
3003
	struct zone *z;
L
Linus Torvalds 已提交
3004

3005 3006 3007
	if (highest_memmap_pfn < end_pfn - 1)
		highest_memmap_pfn = end_pfn - 1;

3008
	z = &NODE_DATA(nid)->node_zones[zone];
3009
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020
		/*
		 * 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
3021 3022
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
3023
		mminit_verify_page_links(page, zone, nid, pfn);
3024
		init_page_count(page);
L
Linus Torvalds 已提交
3025 3026
		reset_page_mapcount(page);
		SetPageReserved(page);
3027 3028 3029 3030 3031
		/*
		 * 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
3032 3033 3034
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
3035 3036 3037 3038 3039
		 *
		 * 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.
3040
		 */
3041 3042 3043
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
3044
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
3045

L
Linus Torvalds 已提交
3046 3047 3048 3049
		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))
3050
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
3051 3052 3053 3054
#endif
	}
}

3055
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
3056
{
3057 3058 3059
	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
3060 3061 3062 3063 3064 3065
		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
3066
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
3067 3068
#endif

3069
static int zone_batchsize(struct zone *zone)
3070
{
3071
#ifdef CONFIG_MMU
3072 3073 3074 3075
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
3076
	 * size of the zone.  But no more than 1/2 of a meg.
3077 3078 3079 3080
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
3081 3082
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
3083 3084 3085 3086 3087
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
3088 3089 3090
	 * 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.
3091
	 *
3092 3093 3094 3095
	 * 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.
3096
	 */
3097
	batch = rounddown_pow_of_two(batch + batch/2) - 1;
3098

3099
	return batch;
3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116

#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
3117 3118
}

A
Adrian Bunk 已提交
3119
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3120 3121
{
	struct per_cpu_pages *pcp;
3122
	int migratetype;
3123

3124 3125
	memset(p, 0, sizeof(*p));

3126
	pcp = &p->pcp;
3127 3128 3129
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
3130 3131
	for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
		INIT_LIST_HEAD(&pcp->lists[migratetype]);
3132 3133
}

3134 3135 3136 3137 3138 3139 3140 3141 3142 3143
/*
 * 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;

3144
	pcp = &p->pcp;
3145 3146 3147 3148 3149 3150
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}

3151
/*
3152 3153 3154 3155
 * Allocate per cpu pagesets and initialize them.
 * Before this call only boot pagesets were available.
 * Boot pagesets will no longer be used by this processorr
 * after setup_per_cpu_pageset().
3156
 */
3157
void __init setup_per_cpu_pageset(void)
3158
{
3159 3160
	struct zone *zone;
	int cpu;
3161

3162
	for_each_populated_zone(zone) {
3163
		zone->pageset = alloc_percpu(struct per_cpu_pageset);
3164

3165 3166
		for_each_possible_cpu(cpu) {
			struct per_cpu_pageset *pcp = per_cpu_ptr(zone->pageset, cpu);
3167

3168
			setup_pageset(pcp, zone_batchsize(zone));
3169

3170 3171 3172 3173 3174
			if (percpu_pagelist_fraction)
				setup_pagelist_highmark(pcp,
					(zone->present_pages /
						percpu_pagelist_fraction));
		}
3175 3176 3177
	}
}

S
Sam Ravnborg 已提交
3178
static noinline __init_refok
3179
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3180 3181 3182
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
3183
	size_t alloc_size;
3184 3185 3186 3187 3188

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
3189 3190 3191 3192
	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);
3193 3194 3195
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

3196
	if (!slab_is_available()) {
3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209
		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.
		 */
3210
		zone->wait_table = vmalloc(alloc_size);
3211 3212 3213
	}
	if (!zone->wait_table)
		return -ENOMEM;
3214

3215
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
3216
		init_waitqueue_head(zone->wait_table + i);
3217 3218

	return 0;
3219 3220
}

3221 3222 3223 3224 3225 3226
static int __zone_pcp_update(void *data)
{
	struct zone *zone = data;
	int cpu;
	unsigned long batch = zone_batchsize(zone), flags;

3227
	for_each_possible_cpu(cpu) {
3228 3229 3230
		struct per_cpu_pageset *pset;
		struct per_cpu_pages *pcp;

3231
		pset = per_cpu_ptr(zone->pageset, cpu);
3232 3233 3234
		pcp = &pset->pcp;

		local_irq_save(flags);
3235
		free_pcppages_bulk(zone, pcp->count, pcp);
3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246
		setup_pageset(pset, batch);
		local_irq_restore(flags);
	}
	return 0;
}

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

3247
static __meminit void zone_pcp_init(struct zone *zone)
3248
{
3249 3250 3251 3252 3253 3254
	/*
	 * 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;
3255

A
Anton Blanchard 已提交
3256
	if (zone->present_pages)
3257 3258 3259
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%u\n",
			zone->name, zone->present_pages,
					 zone_batchsize(zone));
3260 3261
}

3262 3263
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
3264 3265
					unsigned long size,
					enum memmap_context context)
3266 3267
{
	struct pglist_data *pgdat = zone->zone_pgdat;
3268 3269 3270 3271
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
3272 3273 3274 3275
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

3276 3277 3278 3279 3280 3281
	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));

3282
	zone_init_free_lists(zone);
3283 3284

	return 0;
3285 3286
}

3287 3288 3289 3290 3291
#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
 */
3292
static int __meminit first_active_region_index_in_nid(int nid)
3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304
{
	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
3305
 * Note: nid == MAX_NUMNODES returns next region regardless of node
3306
 */
3307
static int __meminit next_active_region_index_in_nid(int index, int nid)
3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322
{
	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
 */
3323
int __meminit __early_pfn_to_nid(unsigned long pfn)
3324 3325 3326 3327 3328 3329 3330 3331 3332 3333
{
	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;
	}
3334 3335
	/* This is a memory hole */
	return -1;
3336 3337 3338
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

3339 3340
int __meminit early_pfn_to_nid(unsigned long pfn)
{
3341 3342 3343 3344 3345 3346 3347
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0)
		return nid;
	/* just returns 0 */
	return 0;
3348 3349
}

3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360
#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
3361

3362 3363 3364 3365 3366 3367 3368
/* 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
3369 3370
 * @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
3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397
 *
 * 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);
	}
}

3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412
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;
}

3413
#ifdef CONFIG_NO_BOOTMEM
3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449
void * __init __alloc_memory_core_early(int nid, u64 size, u64 align,
					u64 goal, u64 limit)
{
	int i;
	void *ptr;

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

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

		if (addr == -1ULL)
			continue;

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

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

	return NULL;
}
3450
#endif
3451 3452


3453 3454 3455
void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
{
	int i;
3456
	int ret;
3457

3458 3459 3460 3461 3462 3463
	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;
	}
3464
}
3465 3466
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
3467
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
3468 3469 3470
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
3471
 * function may be used instead of calling memory_present() manually.
3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484
 */
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
3485 3486 3487
 * @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.
3488 3489 3490 3491
 *
 * 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
3492
 * PFNs will be 0.
3493
 */
3494
void __meminit get_pfn_range_for_nid(unsigned int nid,
3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505
			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);
	}

3506
	if (*start_pfn == -1UL)
3507 3508 3509
		*start_pfn = 0;
}

M
Mel Gorman 已提交
3510 3511 3512 3513 3514
/*
 * 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
3515
static void __init find_usable_zone_for_movable(void)
M
Mel Gorman 已提交
3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540
{
	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
3541
static void __meminit adjust_zone_range_for_zone_movable(int nid,
M
Mel Gorman 已提交
3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566
					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;
	}
}

3567 3568 3569 3570
/*
 * 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
3571
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3572 3573 3574 3575 3576 3577 3578 3579 3580 3581
					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
3582 3583 3584
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599

	/* 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,
3600
 * then all holes in the requested range will be accounted for.
3601
 */
3602
unsigned long __meminit __absent_pages_in_range(int nid,
3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614
				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;

3615 3616
	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);

3617 3618
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
3619
		hole_pages = prev_end_pfn - range_start_pfn;
3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639

	/* 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;
	}

3640 3641
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
3642
		hole_pages += range_end_pfn -
3643 3644
				max(range_start_pfn, prev_end_pfn);

3645 3646 3647 3648 3649 3650 3651 3652
	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
 *
3653
 * It returns the number of pages frames in memory holes within a range.
3654 3655 3656 3657 3658 3659 3660 3661
 */
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
3662
static unsigned long __meminit zone_absent_pages_in_node(int nid,
3663 3664 3665
					unsigned long zone_type,
					unsigned long *ignored)
{
3666 3667 3668 3669 3670 3671 3672 3673 3674
	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
3675 3676 3677
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
3678
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3679
}
3680

3681
#else
P
Paul Mundt 已提交
3682
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3683 3684 3685 3686 3687 3688
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
3689
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3690 3691 3692 3693 3694 3695 3696 3697
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
3698

3699 3700
#endif

3701
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721
		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);
}

3722 3723 3724
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
3725 3726
 * 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
3727 3728 3729 3730 3731 3732 3733
 * 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;

3734 3735
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746
	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;
3747
	if (usemapsize)
3748 3749 3750 3751 3752 3753 3754
		zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize);
}
#else
static void inline setup_usemap(struct pglist_data *pgdat,
				struct zone *zone, unsigned long zonesize) {}
#endif /* CONFIG_SPARSEMEM */

3755
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3756 3757 3758 3759 3760 3761 3762 3763 3764 3765

/* 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;
}

3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780
/* 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 */

3781 3782 3783 3784 3785 3786 3787 3788 3789 3790
/*
 * 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;
}
3791 3792 3793 3794
#define set_pageblock_order(x)	do {} while (0)

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
3795 3796 3797 3798 3799 3800
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
3801
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3802 3803
		unsigned long *zones_size, unsigned long *zholes_size)
{
3804
	enum zone_type j;
3805
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
3806
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
3807
	int ret;
L
Linus Torvalds 已提交
3808

3809
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
3810 3811 3812
	pgdat->nr_zones = 0;
	init_waitqueue_head(&pgdat->kswapd_wait);
	pgdat->kswapd_max_order = 0;
3813
	pgdat_page_cgroup_init(pgdat);
L
Linus Torvalds 已提交
3814 3815 3816
	
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
3817
		unsigned long size, realsize, memmap_pages;
3818
		enum lru_list l;
L
Linus Torvalds 已提交
3819

3820 3821 3822
		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
3823

3824 3825 3826 3827 3828
		/*
		 * 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
		 */
3829 3830
		memmap_pages =
			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
3831 3832
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
3833 3834 3835 3836
			if (memmap_pages)
				printk(KERN_DEBUG
				       "  %s zone: %lu pages used for memmap\n",
				       zone_names[j], memmap_pages);
3837 3838 3839 3840 3841
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

3842 3843
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
3844
			realsize -= dma_reserve;
Y
Yinghai Lu 已提交
3845
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
3846
					zone_names[0], dma_reserve);
3847 3848
		}

3849
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
3850 3851 3852 3853 3854
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
3855
#ifdef CONFIG_NUMA
3856
		zone->node = nid;
3857
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3858
						/ 100;
3859
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3860
#endif
L
Linus Torvalds 已提交
3861 3862 3863
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
3864
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
3865 3866
		zone->zone_pgdat = pgdat;

3867
		zone->prev_priority = DEF_PRIORITY;
L
Linus Torvalds 已提交
3868

3869
		zone_pcp_init(zone);
3870 3871
		for_each_lru(l) {
			INIT_LIST_HEAD(&zone->lru[l].list);
3872
			zone->reclaim_stat.nr_saved_scan[l] = 0;
3873
		}
3874 3875 3876 3877
		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;
3878
		zap_zone_vm_stats(zone);
3879
		zone->flags = 0;
L
Linus Torvalds 已提交
3880 3881 3882
		if (!size)
			continue;

3883
		set_pageblock_order(pageblock_default_order());
3884
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
3885 3886
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
3887
		BUG_ON(ret);
3888
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
3889 3890 3891 3892
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
3893
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
3894 3895 3896 3897 3898
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
3899
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
3900 3901
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
3902
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
3903 3904
		struct page *map;

3905 3906 3907 3908 3909 3910 3911 3912 3913
		/*
		 * 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);
3914 3915 3916
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
3917
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
3918
	}
3919
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
3920 3921 3922
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
3923
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
3924
		mem_map = NODE_DATA(0)->node_mem_map;
3925 3926
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3927
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3928 3929
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
3930
#endif
A
Andy Whitcroft 已提交
3931
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
3932 3933
}

3934 3935
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
3936
{
3937 3938
	pg_data_t *pgdat = NODE_DATA(nid);

L
Linus Torvalds 已提交
3939 3940
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
3941
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
3942 3943

	alloc_node_mem_map(pgdat);
3944 3945 3946 3947 3948
#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
3949 3950 3951 3952

	free_area_init_core(pgdat, zones_size, zholes_size);
}

3953
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
M
Miklos Szeredi 已提交
3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973

#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

3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990
/**
 * 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;

3991 3992 3993 3994 3995
	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);
3996

3997 3998
	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);

3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016
	/* 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 */
4017
		if (start_pfn < early_node_map[i].start_pfn &&
4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037
				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;
}

/**
4038
 * remove_active_range - Shrink an existing registered range of PFNs
4039
 * @nid: The node id the range is on that should be shrunk
4040 4041
 * @start_pfn: The new PFN of the range
 * @end_pfn: The new PFN of the range
4042 4043
 *
 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
4044 4045 4046
 * 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.
4047
 */
4048 4049
void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
				unsigned long end_pfn)
4050
{
4051 4052
	int i, j;
	int removed = 0;
4053

4054 4055 4056
	printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
			  nid, start_pfn, end_pfn);

4057
	/* Find the old active region end and shrink */
4058
	for_each_active_range_index_in_nid(i, nid) {
4059 4060
		if (early_node_map[i].start_pfn >= start_pfn &&
		    early_node_map[i].end_pfn <= end_pfn) {
4061
			/* clear it */
4062
			early_node_map[i].start_pfn = 0;
4063 4064 4065 4066
			early_node_map[i].end_pfn = 0;
			removed = 1;
			continue;
		}
4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078
		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;
4079
			continue;
4080
		}
4081 4082 4083 4084 4085 4086 4087 4088 4089 4090 4091 4092 4093 4094 4095 4096 4097 4098 4099
	}

	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--;
	}
4100 4101 4102 4103
}

/**
 * remove_all_active_ranges - Remove all currently registered regions
4104
 *
4105 4106 4107 4108
 * 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.
 */
4109
void __init remove_all_active_ranges(void)
4110 4111 4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130
{
	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 */
4131
void __init sort_node_map(void)
4132 4133 4134 4135 4136 4137
{
	sort(early_node_map, (size_t)nr_nodemap_entries,
			sizeof(struct node_active_region),
			cmp_node_active_region, NULL);
}

4138
/* Find the lowest pfn for a node */
A
Adrian Bunk 已提交
4139
static unsigned long __init find_min_pfn_for_node(int nid)
4140 4141
{
	int i;
4142
	unsigned long min_pfn = ULONG_MAX;
4143

4144 4145
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
4146
		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
4147

4148 4149
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
4150
			"Could not find start_pfn for node %d\n", nid);
4151 4152 4153 4154
		return 0;
	}

	return min_pfn;
4155 4156 4157 4158 4159 4160
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
4161
 * add_active_range().
4162 4163 4164 4165 4166 4167
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

4168 4169 4170 4171 4172
/*
 * 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
4173
static unsigned long __init early_calculate_totalpages(void)
4174 4175 4176 4177
{
	int i;
	unsigned long totalpages = 0;

4178 4179
	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long pages = early_node_map[i].end_pfn -
4180
						early_node_map[i].start_pfn;
4181 4182 4183 4184 4185
		totalpages += pages;
		if (pages)
			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
	}
  	return totalpages;
4186 4187
}

M
Mel Gorman 已提交
4188 4189 4190 4191 4192 4193
/*
 * 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
4194
static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
M
Mel Gorman 已提交
4195 4196 4197 4198
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
4199 4200
	/* save the state before borrow the nodemask */
	nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4201 4202
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
4203

4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225
	/*
	 * 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
4226 4227
	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
	if (!required_kernelcore)
4228
		goto out;
M
Mel Gorman 已提交
4229 4230 4231 4232 4233 4234 4235 4236

	/* 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;
4237
	for_each_node_state(nid, N_HIGH_MEMORY) {
M
Mel Gorman 已提交
4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302 4303 4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326
		/*
		 * 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);
4327 4328 4329 4330

out:
	/* restore the node_state */
	node_states[N_HIGH_MEMORY] = saved_node_state;
M
Mel Gorman 已提交
4331 4332
}

4333 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346
/* 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
}

4347 4348
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
4349
 * @max_zone_pfn: an array of max PFNs for each zone
4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362
 *
 * 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;
4363
	int i;
4364

4365 4366 4367
	/* Sort early_node_map as initialisation assumes it is sorted */
	sort_node_map();

4368 4369 4370 4371 4372 4373 4374 4375
	/* 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
4376 4377
		if (i == ZONE_MOVABLE)
			continue;
4378 4379 4380 4381 4382
		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
4383 4384 4385 4386 4387 4388
	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);
4389 4390 4391

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
M
Mel Gorman 已提交
4392 4393 4394
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
4395 4396 4397 4398 4399 4400
		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",
4401 4402
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);
M
Mel Gorman 已提交
4403 4404 4405 4406 4407 4408 4409 4410
	}

	/* 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]);
	}
4411 4412 4413 4414

	/* 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++)
4415
		printk("  %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
4416 4417 4418 4419
						early_node_map[i].start_pfn,
						early_node_map[i].end_pfn);

	/* Initialise every node */
4420
	mminit_verify_pageflags_layout();
4421
	setup_nr_node_ids();
4422 4423
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
4424
		free_area_init_node(nid, NULL,
4425
				find_min_pfn_for_node(nid), NULL);
4426 4427 4428 4429 4430

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
4431 4432
	}
}
M
Mel Gorman 已提交
4433

4434
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
4435 4436 4437 4438 4439 4440
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
4441
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
4442

4443
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
4444 4445 4446 4447
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
4448

4449 4450 4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462 4463 4464 4465 4466
/*
 * 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
4467
early_param("kernelcore", cmdline_parse_kernelcore);
4468
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
4469

4470 4471
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

4472
/**
4473 4474
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
4475 4476 4477 4478
 *
 * 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
4479 4480 4481
 * 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.
4482 4483 4484 4485 4486 4487
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

4488
#ifndef CONFIG_NEED_MULTIPLE_NODES
4489 4490 4491 4492 4493
struct pglist_data __refdata contig_page_data = {
#ifndef CONFIG_NO_BOOTMEM
 .bdata = &bootmem_node_data[0]
#endif
 };
L
Linus Torvalds 已提交
4494
EXPORT_SYMBOL(contig_page_data);
4495
#endif
L
Linus Torvalds 已提交
4496 4497 4498

void __init free_area_init(unsigned long *zones_size)
{
4499
	free_area_init_node(0, zones_size,
L
Linus Torvalds 已提交
4500 4501 4502 4503 4504 4505 4506 4507
			__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;

4508
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4509 4510 4511 4512 4513 4514 4515 4516
		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.
		 */
4517
		vm_events_fold_cpu(cpu);
4518 4519 4520 4521 4522 4523 4524 4525

		/*
		 * 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.
		 */
4526
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
4527 4528 4529 4530 4531 4532 4533 4534 4535
	}
	return NOTIFY_OK;
}

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

4536 4537 4538 4539 4540 4541 4542 4543
/*
 * 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;
4544
	enum zone_type i, j;
4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556

	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];
			}

4557 4558
			/* we treat the high watermark as reserved pages. */
			max += high_wmark_pages(zone);
4559 4560 4561 4562 4563 4564 4565 4566 4567

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

L
Linus Torvalds 已提交
4568 4569 4570 4571 4572 4573 4574 4575 4576
/*
 * 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;
4577
	enum zone_type j, idx;
L
Linus Torvalds 已提交
4578

4579
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
4580 4581 4582 4583 4584 4585
		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;

4586 4587
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
4588 4589
				struct zone *lower_zone;

4590 4591
				idx--;

L
Linus Torvalds 已提交
4592 4593 4594 4595 4596 4597 4598 4599 4600 4601
				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;
			}
		}
	}
4602 4603 4604

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4605 4606
}

4607
/**
4608
 * setup_per_zone_wmarks - called when min_free_kbytes changes
4609
 * or when memory is hot-{added|removed}
4610
 *
4611 4612
 * 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
4613
 */
4614
void setup_per_zone_wmarks(void)
L
Linus Torvalds 已提交
4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627
{
	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) {
4628 4629
		u64 tmp;

4630
		spin_lock_irqsave(&zone->lock, flags);
4631 4632
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
4633 4634
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
4635 4636 4637 4638
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
4639
			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
N
Nick Piggin 已提交
4640 4641
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
Linus Torvalds 已提交
4642 4643 4644 4645 4646 4647 4648 4649
			 */
			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;
4650
			zone->watermark[WMARK_MIN] = min_pages;
L
Linus Torvalds 已提交
4651
		} else {
N
Nick Piggin 已提交
4652 4653
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
4654 4655
			 * proportionate to the zone's size.
			 */
4656
			zone->watermark[WMARK_MIN] = tmp;
L
Linus Torvalds 已提交
4657 4658
		}

4659 4660
		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) + (tmp >> 2);
		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
4661
		setup_zone_migrate_reserve(zone);
4662
		spin_unlock_irqrestore(&zone->lock, flags);
L
Linus Torvalds 已提交
4663
	}
4664 4665 4666

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4667 4668
}

4669
/*
4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689
 * 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
 */
4690
void calculate_zone_inactive_ratio(struct zone *zone)
4691
{
4692
	unsigned int gb, ratio;
4693

4694 4695 4696
	/* Zone size in gigabytes */
	gb = zone->present_pages >> (30 - PAGE_SHIFT);
	if (gb)
4697
		ratio = int_sqrt(10 * gb);
4698 4699
	else
		ratio = 1;
4700

4701 4702
	zone->inactive_ratio = ratio;
}
4703

4704 4705 4706 4707 4708 4709
static void __init setup_per_zone_inactive_ratio(void)
{
	struct zone *zone;

	for_each_zone(zone)
		calculate_zone_inactive_ratio(zone);
4710 4711
}

L
Linus Torvalds 已提交
4712 4713 4714 4715 4716 4717 4718 4719 4720 4721 4722 4723 4724 4725 4726 4727 4728 4729 4730 4731 4732 4733 4734 4735
/*
 * 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
 */
4736
static int __init init_per_zone_wmark_min(void)
L
Linus Torvalds 已提交
4737 4738 4739 4740 4741 4742 4743 4744 4745 4746
{
	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;
4747
	setup_per_zone_wmarks();
L
Linus Torvalds 已提交
4748
	setup_per_zone_lowmem_reserve();
4749
	setup_per_zone_inactive_ratio();
L
Linus Torvalds 已提交
4750 4751
	return 0;
}
4752
module_init(init_per_zone_wmark_min)
L
Linus Torvalds 已提交
4753 4754 4755 4756 4757 4758 4759

/*
 * 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, 
4760
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
4761
{
4762
	proc_dointvec(table, write, buffer, length, ppos);
4763
	if (write)
4764
		setup_per_zone_wmarks();
L
Linus Torvalds 已提交
4765 4766 4767
	return 0;
}

4768 4769
#ifdef CONFIG_NUMA
int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
4770
	void __user *buffer, size_t *length, loff_t *ppos)
4771 4772 4773 4774
{
	struct zone *zone;
	int rc;

4775
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
4776 4777 4778 4779
	if (rc)
		return rc;

	for_each_zone(zone)
4780
		zone->min_unmapped_pages = (zone->present_pages *
4781 4782 4783
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
4784 4785

int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
4786
	void __user *buffer, size_t *length, loff_t *ppos)
4787 4788 4789 4790
{
	struct zone *zone;
	int rc;

4791
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
4792 4793 4794 4795 4796 4797 4798 4799
	if (rc)
		return rc;

	for_each_zone(zone)
		zone->min_slab_pages = (zone->present_pages *
				sysctl_min_slab_ratio) / 100;
	return 0;
}
4800 4801
#endif

L
Linus Torvalds 已提交
4802 4803 4804 4805 4806 4807
/*
 * 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
4808
 * minimum watermarks. The lowmem reserve ratio can only make sense
L
Linus Torvalds 已提交
4809 4810 4811
 * if in function of the boot time zone sizes.
 */
int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
4812
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
4813
{
4814
	proc_dointvec_minmax(table, write, buffer, length, ppos);
L
Linus Torvalds 已提交
4815 4816 4817 4818
	setup_per_zone_lowmem_reserve();
	return 0;
}

4819 4820 4821 4822 4823 4824 4825
/*
 * 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,
4826
	void __user *buffer, size_t *length, loff_t *ppos)
4827 4828 4829 4830 4831
{
	struct zone *zone;
	unsigned int cpu;
	int ret;

4832
	ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
4833 4834
	if (!write || (ret == -EINVAL))
		return ret;
4835
	for_each_populated_zone(zone) {
4836
		for_each_possible_cpu(cpu) {
4837 4838
			unsigned long  high;
			high = zone->present_pages / percpu_pagelist_fraction;
4839 4840
			setup_pagelist_highmark(
				per_cpu_ptr(zone->pageset, cpu), high);
4841 4842 4843 4844 4845
		}
	}
	return 0;
}

4846
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
4847 4848 4849 4850 4851 4852 4853 4854 4855 4856 4857 4858 4859 4860 4861 4862 4863 4864 4865 4866 4867 4868 4869 4870 4871 4872 4873 4874 4875 4876 4877 4878 4879 4880

#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
4881
		numentries = nr_kernel_pages;
L
Linus Torvalds 已提交
4882 4883 4884 4885 4886 4887 4888 4889 4890
		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);
4891 4892

		/* Make sure we've got at least a 0-order allocation.. */
4893 4894 4895 4896 4897 4898 4899 4900
		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))
4901
			numentries = PAGE_SIZE / bucketsize;
L
Linus Torvalds 已提交
4902
	}
4903
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
4904 4905 4906 4907 4908 4909 4910 4911 4912 4913

	/* 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;

4914
	log2qty = ilog2(numentries);
L
Linus Torvalds 已提交
4915 4916 4917 4918

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
4919
			table = alloc_bootmem_nopanic(size);
L
Linus Torvalds 已提交
4920 4921 4922
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
4923 4924
			/*
			 * If bucketsize is not a power-of-two, we may free
4925 4926
			 * some pages at the end of hash table which
			 * alloc_pages_exact() automatically does
4927
			 */
4928
			if (get_order(size) < MAX_ORDER) {
4929
				table = alloc_pages_exact(size, GFP_ATOMIC);
4930 4931
				kmemleak_alloc(table, size, 1, GFP_ATOMIC);
			}
L
Linus Torvalds 已提交
4932 4933 4934 4935 4936 4937
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

4938
	printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
L
Linus Torvalds 已提交
4939 4940
	       tablename,
	       (1U << log2qty),
4941
	       ilog2(size) - PAGE_SHIFT,
L
Linus Torvalds 已提交
4942 4943 4944 4945 4946 4947 4948 4949 4950
	       size);

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

	return table;
}
4951

4952 4953 4954 4955 4956 4957 4958 4959 4960 4961 4962 4963 4964 4965 4966
/* 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);
4967
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4968 4969
#else
	pfn = pfn - zone->zone_start_pfn;
4970
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4971 4972 4973 4974
#endif /* CONFIG_SPARSEMEM */
}

/**
4975
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4976 4977 4978 4979 4980 4981 4982 4983 4984 4985 4986 4987 4988 4989 4990 4991 4992 4993 4994 4995 4996 4997
 * @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;
4998

4999 5000 5001 5002
	return flags;
}

/**
5003
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5004 5005 5006 5007 5008 5009 5010 5011 5012 5013 5014 5015 5016 5017 5018 5019 5020
 * @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);
5021 5022
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
5023 5024 5025 5026 5027 5028 5029

	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
5030 5031 5032 5033 5034 5035 5036 5037 5038 5039

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

int set_migratetype_isolate(struct page *page)
{
	struct zone *zone;
5040 5041 5042 5043 5044
	struct page *curr_page;
	unsigned long flags, pfn, iter;
	unsigned long immobile = 0;
	struct memory_isolate_notify arg;
	int notifier_ret;
K
KAMEZAWA Hiroyuki 已提交
5045
	int ret = -EBUSY;
5046
	int zone_idx;
K
KAMEZAWA Hiroyuki 已提交
5047 5048

	zone = page_zone(page);
5049
	zone_idx = zone_idx(zone);
5050

K
KAMEZAWA Hiroyuki 已提交
5051
	spin_lock_irqsave(&zone->lock, flags);
5052 5053 5054 5055 5056 5057 5058 5059 5060 5061 5062
	if (get_pageblock_migratetype(page) == MIGRATE_MOVABLE ||
	    zone_idx == ZONE_MOVABLE) {
		ret = 0;
		goto out;
	}

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

K
KAMEZAWA Hiroyuki 已提交
5063
	/*
5064 5065 5066 5067 5068 5069 5070 5071 5072
	 * 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
5073
	 */
5074 5075 5076
	notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);
	notifier_ret = notifier_to_errno(notifier_ret);
	if (notifier_ret || !arg.pages_found)
K
KAMEZAWA Hiroyuki 已提交
5077
		goto out;
5078 5079 5080 5081 5082 5083 5084 5085 5086 5087 5088 5089 5090 5091 5092

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

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

		immobile++;
	}

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

K
KAMEZAWA Hiroyuki 已提交
5093
out:
5094 5095 5096 5097 5098
	if (!ret) {
		set_pageblock_migratetype(page, MIGRATE_ISOLATE);
		move_freepages_block(zone, page, MIGRATE_ISOLATE);
	}

K
KAMEZAWA Hiroyuki 已提交
5099 5100
	spin_unlock_irqrestore(&zone->lock, flags);
	if (!ret)
5101
		drain_all_pages();
K
KAMEZAWA Hiroyuki 已提交
5102 5103 5104 5105 5106 5107 5108 5109 5110 5111 5112 5113 5114 5115 5116 5117
	return ret;
}

void unset_migratetype_isolate(struct page *page)
{
	struct zone *zone;
	unsigned long flags;
	zone = page_zone(page);
	spin_lock_irqsave(&zone->lock, flags);
	if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
		goto out;
	set_pageblock_migratetype(page, MIGRATE_MOVABLE);
	move_freepages_block(zone, page, MIGRATE_MOVABLE);
out:
	spin_unlock_irqrestore(&zone->lock, flags);
}
K
KAMEZAWA Hiroyuki 已提交
5118 5119 5120 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131 5132 5133 5134 5135 5136 5137 5138 5139 5140 5141 5142 5143 5144 5145 5146 5147 5148 5149 5150 5151 5152 5153 5154 5155 5156 5157 5158 5159 5160 5161 5162 5163 5164

#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
5165 5166 5167 5168 5169 5170 5171 5172 5173 5174 5175 5176 5177 5178 5179 5180 5181 5182 5183 5184 5185

#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