page_alloc.c 127.2 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/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/memcontrol.h>
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#include <linux/debugobjects.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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long nr_swap_pages;
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int percpu_pagelist_fraction;
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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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unsigned long __meminitdata nr_kernel_pages;
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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#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
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  static unsigned long __meminitdata node_boundary_start_pfn[MAX_NUMNODES];
  static unsigned long __meminitdata node_boundary_end_pfn[MAX_NUMNODES];
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#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
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  unsigned long __initdata required_kernelcore;
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  static unsigned long __initdata required_movablecore;
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  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;
EXPORT_SYMBOL(nr_node_ids);
#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)
{
	set_pageblock_flags_group(page, (unsigned long)migratetype,
					PB_migrate, PB_migrate_end);
}

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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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	void *pc = page_get_page_cgroup(page);

	printk(KERN_EMERG "Bad page state in process '%s'\n" KERN_EMERG
		"page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
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		current->comm, page, (int)(2*sizeof(unsigned long)),
		(unsigned long)page->flags, page->mapping,
		page_mapcount(page), page_count(page));
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	if (pc) {
		printk(KERN_EMERG "cgroup:%p\n", pc);
		page_reset_bad_cgroup(page);
	}
	printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n"
		KERN_EMERG "Backtrace:\n");
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	dump_stack();
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	page->flags &= ~PAGE_FLAGS_CLEAR_WHEN_BAD;
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	set_page_count(page, 0);
	reset_page_mapcount(page);
	page->mapping = NULL;
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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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static void prep_compound_page(struct page *page, unsigned long order)
{
	int i;
	int nr_pages = 1 << order;

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

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

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

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	if (unlikely(compound_order(page) != order))
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		bad_page(page);
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	if (unlikely(!PageHead(page)))
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			bad_page(page);
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	__ClearPageHead(page);
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	for (i = 1; i < nr_pages; i++) {
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		struct page *p = page + i;

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		if (unlikely(!PageTail(p) |
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				(p->first_page != page)))
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			bad_page(page);
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		__ClearPageTail(p);
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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) {
		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)
{
	unsigned long page_idx;
	int order_size = 1 << order;
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	int migratetype = get_pageblock_migratetype(page);
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	if (unlikely(PageCompound(page)))
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		destroy_compound_page(page, order);

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

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	VM_BUG_ON(page_idx & (order_size - 1));
	VM_BUG_ON(bad_range(zone, page));
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	__mod_zone_page_state(zone, NR_FREE_PAGES, order_size);
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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;		/* Move the buddy up one level. */
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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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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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		(page_get_page_cgroup(page) != NULL) |
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		(page_count(page) != 0)  |
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		(page->flags & PAGE_FLAGS_CHECK_AT_FREE)))
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		bad_page(page);
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	if (PageDirty(page))
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		__ClearPageDirty(page);
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	/*
	 * For now, we report if PG_reserved was found set, but do not
	 * clear it, and do not free the page.  But we shall soon need
	 * to do more, for when the ZERO_PAGE count wraps negative.
	 */
	return PageReserved(page);
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}

/*
 * Frees a list of pages. 
 * 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_pages_bulk(struct zone *zone, int count,
					struct list_head *list, int order)
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{
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	spin_lock(&zone->lock);
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	zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
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	zone->pages_scanned = 0;
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	while (count--) {
		struct page *page;

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		VM_BUG_ON(list_empty(list));
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		page = list_entry(list->prev, struct page, lru);
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		/* have to delete it as __free_one_page list manipulates */
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		list_del(&page->lru);
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		__free_one_page(page, zone, order);
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	}
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	spin_unlock(&zone->lock);
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}

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static void free_one_page(struct zone *zone, struct page *page, int order)
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{
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	spin_lock(&zone->lock);
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	zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
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	zone->pages_scanned = 0;
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	__free_one_page(page, zone, order);
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	spin_unlock(&zone->lock);
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}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
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	int i;
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	int reserved = 0;
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	for (i = 0 ; i < (1 << order) ; ++i)
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		reserved += free_pages_check(page + i);
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	if (reserved)
		return;

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	if (!PageHighMem(page)) {
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		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
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		debug_check_no_obj_freed(page_address(page),
					   PAGE_SIZE << order);
	}
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Nick Piggin 已提交
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	arch_free_page(page, order);
N
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524
	kernel_map_pages(page, 1 << order, 0);
N
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525

N
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526
	local_irq_save(flags);
527
	__count_vm_events(PGFREE, 1 << order);
N
Nick Piggin 已提交
528
	free_one_page(page_zone(page), page, order);
N
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529
	local_irq_restore(flags);
L
Linus Torvalds 已提交
530 531
}

532 533 534
/*
 * permit the bootmem allocator to evade page validation on high-order frees
 */
535
void __free_pages_bootmem(struct page *page, unsigned int order)
536 537 538 539
{
	if (order == 0) {
		__ClearPageReserved(page);
		set_page_count(page, 0);
540
		set_page_refcounted(page);
N
Nick Piggin 已提交
541
		__free_page(page);
542 543 544
	} else {
		int loop;

N
Nick Piggin 已提交
545
		prefetchw(page);
546 547 548
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

N
Nick Piggin 已提交
549 550
			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
551 552 553 554
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

555
		set_page_refcounted(page);
N
Nick Piggin 已提交
556
		__free_pages(page, order);
557 558 559
	}
}

L
Linus Torvalds 已提交
560 561 562 563 564 565 566 567 568 569 570 571 572 573 574

/*
 * 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
575
static inline void expand(struct zone *zone, struct page *page,
576 577
	int low, int high, struct free_area *area,
	int migratetype)
L
Linus Torvalds 已提交
578 579 580 581 582 583 584
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
585
		VM_BUG_ON(bad_range(zone, &page[size]));
586
		list_add(&page[size].lru, &area->free_list[migratetype]);
L
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587 588 589 590 591 592 593 594
		area->nr_free++;
		set_page_order(&page[size], high);
	}
}

/*
 * This page is about to be returned from the page allocator
 */
N
Nick Piggin 已提交
595
static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
L
Linus Torvalds 已提交
596
{
N
Nick Piggin 已提交
597 598
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
599
		(page_get_page_cgroup(page) != NULL) |
N
Nick Piggin 已提交
600
		(page_count(page) != 0)  |
601
		(page->flags & PAGE_FLAGS_CHECK_AT_PREP)))
N
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602
		bad_page(page);
L
Linus Torvalds 已提交
603

604 605 606 607 608 609 610
	/*
	 * For now, we report if PG_reserved was found set, but do not
	 * clear it, and do not allocate the page: as a safety net.
	 */
	if (PageReserved(page))
		return 1;

611
	page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_reclaim |
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612
			1 << PG_referenced | 1 << PG_arch_1 |
613
			1 << PG_owner_priv_1 | 1 << PG_mappedtodisk);
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Hugh Dickins 已提交
614
	set_page_private(page, 0);
615
	set_page_refcounted(page);
N
Nick Piggin 已提交
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	arch_alloc_page(page, order);
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618
	kernel_map_pages(page, 1 << order, 1);
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619 620 621 622 623 624 625

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

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

626
	return 0;
L
Linus Torvalds 已提交
627 628
}

629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659
/*
 * Go through the free lists for the given migratetype and remove
 * the smallest available page from the freelists
 */
static struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
						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--;
		__mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order));
		expand(zone, page, order, current_order, area, migratetype);
		return page;
	}

	return NULL;
}


660 661 662 663 664
/*
 * 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] = {
665 666 667 668
	[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 */
669 670
};

671 672
/*
 * Move the free pages in a range to the free lists of the requested type.
673
 * Note that start_page and end_pages are not aligned on a pageblock
674 675 676 677 678 679 680 681
 * boundary. If alignment is required, use move_freepages_block()
 */
int move_freepages(struct zone *zone,
			struct page *start_page, struct page *end_page,
			int migratetype)
{
	struct page *page;
	unsigned long order;
682
	int pages_moved = 0;
683 684 685 686 687 688 689

#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
690
	 * grouping pages by mobility
691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710
	 */
	BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif

	for (page = start_page; page <= end_page;) {
		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;
711
		pages_moved += 1 << order;
712 713
	}

714
	return pages_moved;
715 716 717 718 719 720 721 722
}

int move_freepages_block(struct zone *zone, struct page *page, int migratetype)
{
	unsigned long start_pfn, end_pfn;
	struct page *start_page, *end_page;

	start_pfn = page_to_pfn(page);
723
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
724
	start_page = pfn_to_page(start_pfn);
725 726
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
727 728 729 730 731 732 733 734 735 736

	/* 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);
}

737 738 739 740 741 742 743 744 745 746 747 748 749 750 751
/* Remove an element from the buddy allocator from the fallback list */
static struct page *__rmqueue_fallback(struct zone *zone, int order,
						int start_migratetype)
{
	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];

752 753 754
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
				continue;
M
Mel Gorman 已提交
755

756 757 758 759 760 761 762 763 764
			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--;

			/*
765
			 * If breaking a large block of pages, move all free
766 767 768
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
			 * agressive about taking ownership of free pages
769
			 */
770
			if (unlikely(current_order >= (pageblock_order >> 1)) ||
771 772 773 774 775 776
					start_migratetype == MIGRATE_RECLAIMABLE) {
				unsigned long pages;
				pages = move_freepages_block(zone, page,
								start_migratetype);

				/* Claim the whole block if over half of it is free */
777
				if (pages >= (1 << (pageblock_order-1)))
778 779 780
					set_pageblock_migratetype(page,
								start_migratetype);

781
				migratetype = start_migratetype;
782
			}
783 784 785 786 787 788 789

			/* Remove the page from the freelists */
			list_del(&page->lru);
			rmv_page_order(page);
			__mod_zone_page_state(zone, NR_FREE_PAGES,
							-(1UL << order));

790
			if (current_order == pageblock_order)
791 792 793 794 795 796 797 798
				set_pageblock_migratetype(page,
							start_migratetype);

			expand(zone, page, order, current_order, area, migratetype);
			return page;
		}
	}

799 800
	/* Use MIGRATE_RESERVE rather than fail an allocation */
	return __rmqueue_smallest(zone, order, MIGRATE_RESERVE);
801 802
}

803
/*
L
Linus Torvalds 已提交
804 805 806
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
807 808
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
L
Linus Torvalds 已提交
809 810 811
{
	struct page *page;

812
	page = __rmqueue_smallest(zone, order, migratetype);
813

814 815
	if (unlikely(!page))
		page = __rmqueue_fallback(zone, order, migratetype);
816 817

	return page;
L
Linus Torvalds 已提交
818 819 820 821 822 823 824 825
}

/* 
 * 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, 
826 827
			unsigned long count, struct list_head *list,
			int migratetype)
L
Linus Torvalds 已提交
828 829 830
{
	int i;
	
N
Nick Piggin 已提交
831
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
832
	for (i = 0; i < count; ++i) {
833
		struct page *page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
834
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
835
			break;
836 837 838 839 840 841 842 843 844 845

		/*
		 * 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.
		 */
846 847
		list_add(&page->lru, list);
		set_page_private(page, migratetype);
848
		list = &page->lru;
L
Linus Torvalds 已提交
849
	}
N
Nick Piggin 已提交
850
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
851
	return i;
L
Linus Torvalds 已提交
852 853
}

854
#ifdef CONFIG_NUMA
855
/*
856 857 858 859
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
860 861
 * Note that this function must be called with the thread pinned to
 * a single processor.
862
 */
863
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
864 865
{
	unsigned long flags;
866
	int to_drain;
867

868 869 870 871 872 873 874 875
	local_irq_save(flags);
	if (pcp->count >= pcp->batch)
		to_drain = pcp->batch;
	else
		to_drain = pcp->count;
	free_pages_bulk(zone, to_drain, &pcp->list, 0);
	pcp->count -= to_drain;
	local_irq_restore(flags);
876 877 878
}
#endif

879 880 881 882 883 884 885 886
/*
 * 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
887
{
N
Nick Piggin 已提交
888
	unsigned long flags;
L
Linus Torvalds 已提交
889 890 891 892
	struct zone *zone;

	for_each_zone(zone) {
		struct per_cpu_pageset *pset;
893
		struct per_cpu_pages *pcp;
L
Linus Torvalds 已提交
894

895 896 897
		if (!populated_zone(zone))
			continue;

898
		pset = zone_pcp(zone, cpu);
899 900 901 902 903 904

		pcp = &pset->pcp;
		local_irq_save(flags);
		free_pages_bulk(zone, pcp->count, &pcp->list, 0);
		pcp->count = 0;
		local_irq_restore(flags);
L
Linus Torvalds 已提交
905 906 907
	}
}

908 909 910 911 912 913 914 915 916 917 918 919 920
/*
 * 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)
{
921
	on_each_cpu(drain_local_pages, NULL, 1);
922 923
}

924
#ifdef CONFIG_HIBERNATION
L
Linus Torvalds 已提交
925 926 927

void mark_free_pages(struct zone *zone)
{
928 929
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
930
	int order, t;
L
Linus Torvalds 已提交
931 932 933 934 935 936
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
937 938 939 940 941 942

	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);

943 944
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
945
		}
L
Linus Torvalds 已提交
946

947 948
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
949
			unsigned long i;
L
Linus Torvalds 已提交
950

951 952
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
953
				swsusp_set_page_free(pfn_to_page(pfn + i));
954
		}
955
	}
L
Linus Torvalds 已提交
956 957
	spin_unlock_irqrestore(&zone->lock, flags);
}
958
#endif /* CONFIG_PM */
L
Linus Torvalds 已提交
959 960 961 962

/*
 * Free a 0-order page
 */
H
Harvey Harrison 已提交
963
static void free_hot_cold_page(struct page *page, int cold)
L
Linus Torvalds 已提交
964 965 966 967 968 969 970
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;

	if (PageAnon(page))
		page->mapping = NULL;
N
Nick Piggin 已提交
971
	if (free_pages_check(page))
972 973
		return;

974
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
975
		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
976 977
		debug_check_no_obj_freed(page_address(page), PAGE_SIZE);
	}
N
Nick Piggin 已提交
978
	arch_free_page(page, 0);
979 980
	kernel_map_pages(page, 1, 0);

981
	pcp = &zone_pcp(zone, get_cpu())->pcp;
L
Linus Torvalds 已提交
982
	local_irq_save(flags);
983
	__count_vm_event(PGFREE);
984 985 986 987
	if (cold)
		list_add_tail(&page->lru, &pcp->list);
	else
		list_add(&page->lru, &pcp->list);
988
	set_page_private(page, get_pageblock_migratetype(page));
L
Linus Torvalds 已提交
989
	pcp->count++;
N
Nick Piggin 已提交
990 991 992 993
	if (pcp->count >= pcp->high) {
		free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
		pcp->count -= pcp->batch;
	}
L
Linus Torvalds 已提交
994 995 996 997
	local_irq_restore(flags);
	put_cpu();
}

H
Harvey Harrison 已提交
998
void free_hot_page(struct page *page)
L
Linus Torvalds 已提交
999 1000 1001 1002
{
	free_hot_cold_page(page, 0);
}
	
H
Harvey Harrison 已提交
1003
void free_cold_page(struct page *page)
L
Linus Torvalds 已提交
1004 1005 1006 1007
{
	free_hot_cold_page(page, 1);
}

N
Nick Piggin 已提交
1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019
/*
 * 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
1020 1021
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1022 1023
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
1024 1025
}

L
Linus Torvalds 已提交
1026 1027 1028 1029 1030
/*
 * 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.
 */
1031
static struct page *buffered_rmqueue(struct zone *preferred_zone,
N
Nick Piggin 已提交
1032
			struct zone *zone, int order, gfp_t gfp_flags)
L
Linus Torvalds 已提交
1033 1034
{
	unsigned long flags;
1035
	struct page *page;
L
Linus Torvalds 已提交
1036
	int cold = !!(gfp_flags & __GFP_COLD);
N
Nick Piggin 已提交
1037
	int cpu;
1038
	int migratetype = allocflags_to_migratetype(gfp_flags);
L
Linus Torvalds 已提交
1039

1040
again:
N
Nick Piggin 已提交
1041
	cpu  = get_cpu();
N
Nick Piggin 已提交
1042
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1043 1044
		struct per_cpu_pages *pcp;

1045
		pcp = &zone_pcp(zone, cpu)->pcp;
L
Linus Torvalds 已提交
1046
		local_irq_save(flags);
N
Nick Piggin 已提交
1047
		if (!pcp->count) {
1048
			pcp->count = rmqueue_bulk(zone, 0,
1049
					pcp->batch, &pcp->list, migratetype);
N
Nick Piggin 已提交
1050 1051
			if (unlikely(!pcp->count))
				goto failed;
L
Linus Torvalds 已提交
1052
		}
1053

1054
		/* Find a page of the appropriate migrate type */
1055 1056 1057 1058 1059 1060 1061 1062 1063
		if (cold) {
			list_for_each_entry_reverse(page, &pcp->list, lru)
				if (page_private(page) == migratetype)
					break;
		} else {
			list_for_each_entry(page, &pcp->list, lru)
				if (page_private(page) == migratetype)
					break;
		}
1064

1065 1066
		/* Allocate more to the pcp list if necessary */
		if (unlikely(&page->lru == &pcp->list)) {
1067 1068 1069 1070
			pcp->count += rmqueue_bulk(zone, 0,
					pcp->batch, &pcp->list, migratetype);
			page = list_entry(pcp->list.next, struct page, lru);
		}
1071 1072 1073

		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1074
	} else {
L
Linus Torvalds 已提交
1075
		spin_lock_irqsave(&zone->lock, flags);
1076
		page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1077 1078 1079
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
L
Linus Torvalds 已提交
1080 1081
	}

1082
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1083
	zone_statistics(preferred_zone, zone);
N
Nick Piggin 已提交
1084 1085
	local_irq_restore(flags);
	put_cpu();
L
Linus Torvalds 已提交
1086

N
Nick Piggin 已提交
1087
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1088
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1089
		goto again;
L
Linus Torvalds 已提交
1090
	return page;
N
Nick Piggin 已提交
1091 1092 1093 1094 1095

failed:
	local_irq_restore(flags);
	put_cpu();
	return NULL;
L
Linus Torvalds 已提交
1096 1097
}

R
Rohit Seth 已提交
1098
#define ALLOC_NO_WATERMARKS	0x01 /* don't check watermarks at all */
1099 1100 1101 1102 1103 1104
#define ALLOC_WMARK_MIN		0x02 /* use pages_min watermark */
#define ALLOC_WMARK_LOW		0x04 /* use pages_low watermark */
#define ALLOC_WMARK_HIGH	0x08 /* use pages_high watermark */
#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
1105

1106 1107 1108 1109 1110 1111 1112
#ifdef CONFIG_FAIL_PAGE_ALLOC

static struct fail_page_alloc_attr {
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1113
	u32 min_order;
1114 1115 1116 1117 1118

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

	struct dentry *ignore_gfp_highmem_file;
	struct dentry *ignore_gfp_wait_file;
1119
	struct dentry *min_order_file;
1120 1121 1122 1123 1124

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1125 1126
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1127
	.min_order = 1,
1128 1129 1130 1131 1132 1133 1134 1135 1136 1137
};

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)
{
1138 1139
	if (order < fail_page_alloc.min_order)
		return 0;
1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170
	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);
1171 1172 1173
	fail_page_alloc.min_order_file =
		debugfs_create_u32("min-order", mode, dir,
				   &fail_page_alloc.min_order);
1174 1175

	if (!fail_page_alloc.ignore_gfp_wait_file ||
1176 1177
            !fail_page_alloc.ignore_gfp_highmem_file ||
            !fail_page_alloc.min_order_file) {
1178 1179 1180
		err = -ENOMEM;
		debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
		debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1181
		debugfs_remove(fail_page_alloc.min_order_file);
1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200
		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
1201 1202 1203 1204 1205
/*
 * 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
1206
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
1207 1208
{
	/* free_pages my go negative - that's OK */
1209 1210
	long min = mark;
	long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
L
Linus Torvalds 已提交
1211 1212
	int o;

R
Rohit Seth 已提交
1213
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1214
		min -= min / 2;
R
Rohit Seth 已提交
1215
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232
		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;
}

1233 1234 1235 1236 1237 1238
#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
1239
 * that have to skip over a lot of full or unallowed zones.
1240 1241 1242
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1243
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264
 *
 * 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
1265
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1266 1267 1268 1269 1270 1271
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1272
					&node_states[N_HIGH_MEMORY];
1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297
	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.
 */
1298
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1299 1300 1301 1302 1303 1304 1305 1306 1307 1308
						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;

1309
	i = z - zonelist->_zonerefs;
1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320
	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.
 */
1321
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1322 1323 1324 1325 1326 1327 1328 1329
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

1330
	i = z - zonelist->_zonerefs;
1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

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

1342
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1343 1344 1345 1346 1347
				nodemask_t *allowednodes)
{
	return 1;
}

1348
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1349 1350 1351 1352
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1353
/*
1354
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1355 1356 1357
 * a page.
 */
static struct page *
1358
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1359
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags)
M
Martin Hicks 已提交
1360
{
1361
	struct zoneref *z;
R
Rohit Seth 已提交
1362
	struct page *page = NULL;
1363
	int classzone_idx;
1364
	struct zone *zone, *preferred_zone;
1365 1366 1367
	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 */
1368

1369 1370
	(void)first_zones_zonelist(zonelist, high_zoneidx, nodemask,
							&preferred_zone);
1371 1372 1373
	if (!preferred_zone)
		return NULL;

1374
	classzone_idx = zone_idx(preferred_zone);
R
Rohit Seth 已提交
1375

1376
zonelist_scan:
R
Rohit Seth 已提交
1377
	/*
1378
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1379 1380
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1381 1382
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1383 1384 1385
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1386
		if ((alloc_flags & ALLOC_CPUSET) &&
1387
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1388
				goto try_next_zone;
R
Rohit Seth 已提交
1389 1390

		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1391 1392
			unsigned long mark;
			if (alloc_flags & ALLOC_WMARK_MIN)
1393
				mark = zone->pages_min;
1394
			else if (alloc_flags & ALLOC_WMARK_LOW)
1395
				mark = zone->pages_low;
1396
			else
1397
				mark = zone->pages_high;
1398 1399
			if (!zone_watermark_ok(zone, order, mark,
				    classzone_idx, alloc_flags)) {
1400
				if (!zone_reclaim_mode ||
1401
				    !zone_reclaim(zone, gfp_mask, order))
1402
					goto this_zone_full;
1403
			}
R
Rohit Seth 已提交
1404 1405
		}

1406
		page = buffered_rmqueue(preferred_zone, zone, order, gfp_mask);
1407
		if (page)
R
Rohit Seth 已提交
1408
			break;
1409 1410 1411 1412 1413 1414 1415 1416 1417 1418
this_zone_full:
		if (NUMA_BUILD)
			zlc_mark_zone_full(zonelist, z);
try_next_zone:
		if (NUMA_BUILD && !did_zlc_setup) {
			/* we do zlc_setup after the first zone is tried */
			allowednodes = zlc_setup(zonelist, alloc_flags);
			zlc_active = 1;
			did_zlc_setup = 1;
		}
1419
	}
1420 1421 1422 1423 1424 1425

	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
1426
	return page;
M
Martin Hicks 已提交
1427 1428
}

L
Linus Torvalds 已提交
1429 1430 1431
/*
 * This is the 'heart' of the zoned buddy allocator.
 */
1432 1433 1434
static struct page *
__alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
			struct zonelist *zonelist, nodemask_t *nodemask)
L
Linus Torvalds 已提交
1435
{
A
Al Viro 已提交
1436
	const gfp_t wait = gfp_mask & __GFP_WAIT;
1437
	enum zone_type high_zoneidx = gfp_zone(gfp_mask);
1438 1439
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
1440 1441 1442 1443
	struct page *page;
	struct reclaim_state reclaim_state;
	struct task_struct *p = current;
	int do_retry;
R
Rohit Seth 已提交
1444
	int alloc_flags;
1445 1446
	unsigned long did_some_progress;
	unsigned long pages_reclaimed = 0;
L
Linus Torvalds 已提交
1447 1448 1449

	might_sleep_if(wait);

1450 1451 1452
	if (should_fail_alloc_page(gfp_mask, order))
		return NULL;

1453
restart:
1454
	z = zonelist->_zonerefs;  /* the list of zones suitable for gfp_mask */
L
Linus Torvalds 已提交
1455

1456
	if (unlikely(!z->zone)) {
1457 1458 1459 1460
		/*
		 * Happens if we have an empty zonelist as a result of
		 * GFP_THISNODE being used on a memoryless node
		 */
L
Linus Torvalds 已提交
1461 1462
		return NULL;
	}
1463

1464
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
1465
			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET);
R
Rohit Seth 已提交
1466 1467
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1468

1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479
	/*
	 * 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;

1480 1481
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
		wakeup_kswapd(zone, order);
L
Linus Torvalds 已提交
1482

1483
	/*
R
Rohit Seth 已提交
1484 1485 1486 1487 1488 1489
	 * 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.
	 *
	 * The caller may dip into page reserves a bit more if the caller
	 * cannot run direct reclaim, or if the caller has realtime scheduling
P
Paul Jackson 已提交
1490 1491
	 * policy or is asking for __GFP_HIGH memory.  GFP_ATOMIC requests will
	 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1492
	 */
1493
	alloc_flags = ALLOC_WMARK_MIN;
R
Rohit Seth 已提交
1494 1495 1496 1497
	if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)
		alloc_flags |= ALLOC_HARDER;
	if (gfp_mask & __GFP_HIGH)
		alloc_flags |= ALLOC_HIGH;
1498 1499
	if (wait)
		alloc_flags |= ALLOC_CPUSET;
L
Linus Torvalds 已提交
1500 1501 1502

	/*
	 * Go through the zonelist again. Let __GFP_HIGH and allocations
R
Rohit Seth 已提交
1503
	 * coming from realtime tasks go deeper into reserves.
L
Linus Torvalds 已提交
1504 1505 1506
	 *
	 * This is the last chance, in general, before the goto nopage.
	 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1507
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
L
Linus Torvalds 已提交
1508
	 */
1509
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1510
						high_zoneidx, alloc_flags);
R
Rohit Seth 已提交
1511 1512
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1513 1514

	/* This allocation should allow future memory freeing. */
1515

1516
rebalance:
1517 1518 1519
	if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
			&& !in_interrupt()) {
		if (!(gfp_mask & __GFP_NOMEMALLOC)) {
K
Kirill Korotaev 已提交
1520
nofail_alloc:
1521
			/* go through the zonelist yet again, ignoring mins */
1522
			page = get_page_from_freelist(gfp_mask, nodemask, order,
1523
				zonelist, high_zoneidx, ALLOC_NO_WATERMARKS);
R
Rohit Seth 已提交
1524 1525
			if (page)
				goto got_pg;
K
Kirill Korotaev 已提交
1526
			if (gfp_mask & __GFP_NOFAIL) {
1527
				congestion_wait(WRITE, HZ/50);
K
Kirill Korotaev 已提交
1528 1529
				goto nofail_alloc;
			}
L
Linus Torvalds 已提交
1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540
		}
		goto nopage;
	}

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

	cond_resched();

	/* We now go into synchronous reclaim */
1541
	cpuset_memory_pressure_bump();
L
Linus Torvalds 已提交
1542 1543 1544 1545
	p->flags |= PF_MEMALLOC;
	reclaim_state.reclaimed_slab = 0;
	p->reclaim_state = &reclaim_state;

1546
	did_some_progress = try_to_free_pages(zonelist, order, gfp_mask);
L
Linus Torvalds 已提交
1547 1548 1549 1550 1551 1552

	p->reclaim_state = NULL;
	p->flags &= ~PF_MEMALLOC;

	cond_resched();

1553
	if (order != 0)
1554
		drain_all_pages();
1555

L
Linus Torvalds 已提交
1556
	if (likely(did_some_progress)) {
1557
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1558
					zonelist, high_zoneidx, alloc_flags);
R
Rohit Seth 已提交
1559 1560
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
1561
	} else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1562
		if (!try_set_zone_oom(zonelist, gfp_mask)) {
1563 1564 1565 1566
			schedule_timeout_uninterruptible(1);
			goto restart;
		}

L
Linus Torvalds 已提交
1567 1568 1569 1570 1571 1572
		/*
		 * 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.
		 */
1573 1574 1575
		page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
			order, zonelist, high_zoneidx,
			ALLOC_WMARK_HIGH|ALLOC_CPUSET);
1576
		if (page) {
1577
			clear_zonelist_oom(zonelist, gfp_mask);
R
Rohit Seth 已提交
1578
			goto got_pg;
1579
		}
L
Linus Torvalds 已提交
1580

1581
		/* The OOM killer will not help higher order allocs so fail */
1582
		if (order > PAGE_ALLOC_COSTLY_ORDER) {
1583
			clear_zonelist_oom(zonelist, gfp_mask);
1584
			goto nopage;
1585
		}
1586

1587
		out_of_memory(zonelist, gfp_mask, order);
1588
		clear_zonelist_oom(zonelist, gfp_mask);
L
Linus Torvalds 已提交
1589 1590 1591 1592 1593 1594 1595
		goto restart;
	}

	/*
	 * Don't let big-order allocations loop unless the caller explicitly
	 * requests that.  Wait for some write requests to complete then retry.
	 *
1596 1597
	 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
	 * means __GFP_NOFAIL, but that may not be true in other
1598
	 * implementations.
1599 1600 1601 1602 1603 1604
	 *
	 * 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.
L
Linus Torvalds 已提交
1605
	 */
1606
	pages_reclaimed += did_some_progress;
L
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1607 1608
	do_retry = 0;
	if (!(gfp_mask & __GFP_NORETRY)) {
1609
		if (order <= PAGE_ALLOC_COSTLY_ORDER) {
L
Linus Torvalds 已提交
1610
			do_retry = 1;
1611 1612 1613 1614 1615
		} else {
			if (gfp_mask & __GFP_REPEAT &&
				pages_reclaimed < (1 << order))
					do_retry = 1;
		}
L
Linus Torvalds 已提交
1616 1617 1618 1619
		if (gfp_mask & __GFP_NOFAIL)
			do_retry = 1;
	}
	if (do_retry) {
1620
		congestion_wait(WRITE, HZ/50);
L
Linus Torvalds 已提交
1621 1622 1623 1624 1625 1626 1627 1628 1629
		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
1630
		show_mem();
L
Linus Torvalds 已提交
1631 1632 1633 1634 1635
	}
got_pg:
	return page;
}

1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649
struct page *
__alloc_pages(gfp_t gfp_mask, unsigned int order,
		struct zonelist *zonelist)
{
	return __alloc_pages_internal(gfp_mask, order, zonelist, NULL);
}

struct page *
__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
		struct zonelist *zonelist, nodemask_t *nodemask)
{
	return __alloc_pages_internal(gfp_mask, order, zonelist, nodemask);
}

L
Linus Torvalds 已提交
1650 1651 1652 1653 1654
EXPORT_SYMBOL(__alloc_pages);

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
1655
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
1656 1657 1658 1659 1660 1661 1662 1663 1664 1665
{
	struct page * page;
	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
1666
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
1667 1668 1669 1670 1671 1672 1673
{
	struct page * page;

	/*
	 * get_zeroed_page() returns a 32-bit address, which cannot represent
	 * a highmem page
	 */
N
Nick Piggin 已提交
1674
	VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
L
Linus Torvalds 已提交
1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691

	page = alloc_pages(gfp_mask | __GFP_ZERO, 0);
	if (page)
		return (unsigned long) page_address(page);
	return 0;
}

EXPORT_SYMBOL(get_zeroed_page);

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

	while (--i >= 0)
		free_hot_cold_page(pvec->pages[i], pvec->cold);
}

H
Harvey Harrison 已提交
1692
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
1693
{
N
Nick Piggin 已提交
1694
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
1695 1696 1697 1698 1699 1700 1701 1702 1703
		if (order == 0)
			free_hot_page(page);
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
1704
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
1705 1706
{
	if (addr != 0) {
N
Nick Piggin 已提交
1707
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
1708 1709 1710 1711 1712 1713 1714 1715
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

static unsigned int nr_free_zone_pages(int offset)
{
1716
	struct zoneref *z;
1717 1718
	struct zone *zone;

1719
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
1720 1721
	unsigned int sum = 0;

1722
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
1723

1724
	for_each_zone_zonelist(zone, z, zonelist, offset) {
1725 1726 1727 1728
		unsigned long size = zone->present_pages;
		unsigned long high = zone->pages_high;
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
1729 1730 1731 1732 1733 1734 1735 1736 1737 1738
	}

	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
1739
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
1740
}
1741
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
1742 1743 1744 1745 1746 1747

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
1748
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
1749
}
1750 1751

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
1752
{
1753
	if (NUMA_BUILD)
1754
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
1755 1756 1757 1758 1759 1760
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
1761
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775
	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;
1776
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
1777
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
1778
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
1779 1780
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
1781 1782 1783 1784
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797
	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)
{
1798
	int cpu;
L
Linus Torvalds 已提交
1799 1800 1801
	struct zone *zone;

	for_each_zone(zone) {
1802
		if (!populated_zone(zone))
L
Linus Torvalds 已提交
1803
			continue;
1804 1805 1806

		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
1807

1808
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
1809 1810
			struct per_cpu_pageset *pageset;

1811
			pageset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
1812

1813 1814 1815
			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
1816 1817 1818
		}
	}

1819
	printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu\n"
1820
		" free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
1821 1822
		global_page_state(NR_ACTIVE),
		global_page_state(NR_INACTIVE),
1823
		global_page_state(NR_FILE_DIRTY),
1824
		global_page_state(NR_WRITEBACK),
1825
		global_page_state(NR_UNSTABLE_NFS),
1826
		global_page_state(NR_FREE_PAGES),
1827 1828
		global_page_state(NR_SLAB_RECLAIMABLE) +
			global_page_state(NR_SLAB_UNRECLAIMABLE),
1829
		global_page_state(NR_FILE_MAPPED),
1830 1831
		global_page_state(NR_PAGETABLE),
		global_page_state(NR_BOUNCE));
L
Linus Torvalds 已提交
1832 1833 1834 1835

	for_each_zone(zone) {
		int i;

1836 1837 1838
		if (!populated_zone(zone))
			continue;

L
Linus Torvalds 已提交
1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851
		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
			" active:%lukB"
			" inactive:%lukB"
			" present:%lukB"
			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
1852
			K(zone_page_state(zone, NR_FREE_PAGES)),
L
Linus Torvalds 已提交
1853 1854 1855
			K(zone->pages_min),
			K(zone->pages_low),
			K(zone->pages_high),
1856 1857
			K(zone_page_state(zone, NR_ACTIVE)),
			K(zone_page_state(zone, NR_INACTIVE)),
L
Linus Torvalds 已提交
1858 1859
			K(zone->present_pages),
			zone->pages_scanned,
1860
			(zone_is_all_unreclaimable(zone) ? "yes" : "no")
L
Linus Torvalds 已提交
1861 1862 1863 1864 1865 1866 1867 1868
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

	for_each_zone(zone) {
1869
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
L
Linus Torvalds 已提交
1870

1871 1872 1873
		if (!populated_zone(zone))
			continue;

L
Linus Torvalds 已提交
1874 1875 1876 1877 1878
		show_node(zone);
		printk("%s: ", zone->name);

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
1879 1880
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
L
Linus Torvalds 已提交
1881 1882
		}
		spin_unlock_irqrestore(&zone->lock, flags);
1883 1884
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
L
Linus Torvalds 已提交
1885 1886 1887
		printk("= %lukB\n", K(total));
	}

1888 1889
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

L
Linus Torvalds 已提交
1890 1891 1892
	show_swap_cache_info();
}

1893 1894 1895 1896 1897 1898
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
{
	zoneref->zone = zone;
	zoneref->zone_idx = zone_idx(zone);
}

L
Linus Torvalds 已提交
1899 1900
/*
 * Builds allocation fallback zone lists.
1901 1902
 *
 * Add all populated zones of a node to the zonelist.
L
Linus Torvalds 已提交
1903
 */
1904 1905
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
1906
{
1907 1908
	struct zone *zone;

1909
	BUG_ON(zone_type >= MAX_NR_ZONES);
1910
	zone_type++;
1911 1912

	do {
1913
		zone_type--;
1914
		zone = pgdat->node_zones + zone_type;
1915
		if (populated_zone(zone)) {
1916 1917
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
1918
			check_highest_zone(zone_type);
L
Linus Torvalds 已提交
1919
		}
1920

1921
	} while (zone_type);
1922
	return nr_zones;
L
Linus Torvalds 已提交
1923 1924
}

1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945

/*
 *  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
1946
#ifdef CONFIG_NUMA
1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
/* The value user specified ....changed by config */
static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
/* string for sysctl */
#define NUMA_ZONELIST_ORDER_LEN	16
char numa_zonelist_order[16] = "default";

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

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

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

/*
 * sysctl handler for numa_zonelist_order
 */
int numa_zonelist_order_handler(ctl_table *table, int write,
		struct file *file, void __user *buffer, size_t *length,
		loff_t *ppos)
{
	char saved_string[NUMA_ZONELIST_ORDER_LEN];
	int ret;

	if (write)
		strncpy(saved_string, (char*)table->data,
			NUMA_ZONELIST_ORDER_LEN);
	ret = proc_dostring(table, write, file, buffer, length, ppos);
	if (ret)
		return ret;
	if (write) {
		int oldval = user_zonelist_order;
		if (__parse_numa_zonelist_order((char*)table->data)) {
			/*
			 * bogus value.  restore saved string
			 */
			strncpy((char*)table->data, saved_string,
				NUMA_ZONELIST_ORDER_LEN);
			user_zonelist_order = oldval;
		} else if (oldval != user_zonelist_order)
			build_all_zonelists();
	}
	return 0;
}


L
Linus Torvalds 已提交
2018
#define MAX_NODE_LOAD (num_online_nodes())
2019 2020
static int node_load[MAX_NUMNODES];

L
Linus Torvalds 已提交
2021
/**
2022
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
Linus Torvalds 已提交
2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034
 * @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.
 */
2035
static int find_next_best_node(int node, nodemask_t *used_node_mask)
L
Linus Torvalds 已提交
2036
{
2037
	int n, val;
L
Linus Torvalds 已提交
2038 2039
	int min_val = INT_MAX;
	int best_node = -1;
2040
	node_to_cpumask_ptr(tmp, 0);
L
Linus Torvalds 已提交
2041

2042 2043 2044 2045 2046
	/* 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
2047

2048
	for_each_node_state(n, N_HIGH_MEMORY) {
L
Linus Torvalds 已提交
2049 2050 2051 2052 2053 2054 2055 2056

		/* 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);

2057 2058 2059
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
Linus Torvalds 已提交
2060
		/* Give preference to headless and unused nodes */
2061 2062
		node_to_cpumask_ptr_next(tmp, n);
		if (!cpus_empty(*tmp))
L
Linus Torvalds 已提交
2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080
			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;
}

2081 2082 2083 2084 2085 2086 2087

/*
 * 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
2088
{
2089
	int j;
L
Linus Torvalds 已提交
2090
	struct zonelist *zonelist;
2091

2092
	zonelist = &pgdat->node_zonelists[0];
2093
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2094 2095 2096
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
2097 2098
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2099 2100
}

2101 2102 2103 2104 2105 2106 2107 2108
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

2109 2110
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2111 2112
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2113 2114
}

2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129
/*
 * 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;

2130 2131 2132 2133 2134 2135 2136
	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)) {
2137 2138
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
2139
				check_highest_zone(zone_type);
2140 2141 2142
			}
		}
	}
2143 2144
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179
}

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.
         */
2180 2181
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212
	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
2213
	nodemask_t used_mask;
2214 2215 2216
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
L
Linus Torvalds 已提交
2217 2218

	/* initialize zonelists */
2219
	for (i = 0; i < MAX_ZONELISTS; i++) {
L
Linus Torvalds 已提交
2220
		zonelist = pgdat->node_zonelists + i;
2221 2222
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
L
Linus Torvalds 已提交
2223 2224 2225 2226 2227 2228 2229
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
	load = num_online_nodes();
	prev_node = local_node;
	nodes_clear(used_mask);
2230 2231 2232 2233 2234

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

L
Linus Torvalds 已提交
2235
	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2236 2237 2238 2239 2240 2241 2242 2243 2244
		int distance = node_distance(local_node, node);

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

L
Linus Torvalds 已提交
2245 2246 2247 2248 2249
		/*
		 * 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.
		 */
2250
		if (distance != node_distance(local_node, prev_node))
2251 2252
			node_load[node] = load;

L
Linus Torvalds 已提交
2253 2254
		prev_node = node;
		load--;
2255 2256 2257 2258 2259
		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
2260

2261 2262 2263
	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
2264
	}
2265 2266

	build_thisnode_zonelists(pgdat);
L
Linus Torvalds 已提交
2267 2268
}

2269
/* Construct the zonelist performance cache - see further mmzone.h */
2270
static void build_zonelist_cache(pg_data_t *pgdat)
2271
{
2272 2273
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
2274
	struct zoneref *z;
2275

2276 2277 2278
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2279 2280
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2281 2282
}

2283

L
Linus Torvalds 已提交
2284 2285
#else	/* CONFIG_NUMA */

2286 2287 2288 2289 2290 2291
static void set_zonelist_order(void)
{
	current_zonelist_order = ZONELIST_ORDER_ZONE;
}

static void build_zonelists(pg_data_t *pgdat)
L
Linus Torvalds 已提交
2292
{
2293
	int node, local_node;
2294 2295
	enum zone_type j;
	struct zonelist *zonelist;
L
Linus Torvalds 已提交
2296 2297 2298

	local_node = pgdat->node_id;

2299 2300
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
2301

2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314
	/*
	 * 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
2315
	}
2316 2317 2318 2319 2320 2321 2322
	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);
	}

2323 2324
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
L
Linus Torvalds 已提交
2325 2326
}

2327
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2328
static void build_zonelist_cache(pg_data_t *pgdat)
2329
{
2330
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
2331 2332
}

L
Linus Torvalds 已提交
2333 2334
#endif	/* CONFIG_NUMA */

2335
/* return values int ....just for stop_machine_run() */
2336
static int __build_all_zonelists(void *dummy)
L
Linus Torvalds 已提交
2337
{
2338
	int nid;
2339 2340

	for_each_online_node(nid) {
2341 2342 2343 2344
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
2345
	}
2346 2347 2348
	return 0;
}

2349
void build_all_zonelists(void)
2350
{
2351 2352
	set_zonelist_order();

2353
	if (system_state == SYSTEM_BOOTING) {
2354
		__build_all_zonelists(NULL);
2355
		mminit_verify_zonelist();
2356 2357
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
2358
		/* we have to stop all cpus to guarantee there is no user
2359 2360 2361 2362
		   of zonelist */
		stop_machine_run(__build_all_zonelists, NULL, NR_CPUS);
		/* cpuset refresh routine should be here */
	}
2363
	vm_total_pages = nr_free_pagecache_pages();
2364 2365 2366 2367 2368 2369 2370
	/*
	 * 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
	 */
2371
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2372 2373 2374 2375 2376 2377
		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",
2378 2379
			num_online_nodes(),
			zonelist_order_name[current_zonelist_order],
2380
			page_group_by_mobility_disabled ? "off" : "on",
2381 2382 2383 2384
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
L
Linus Torvalds 已提交
2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399
}

/*
 * 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

2400
#ifndef CONFIG_MEMORY_HOTPLUG
2401
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
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Linus Torvalds 已提交
2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418
{
	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);
}
2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441
#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
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Linus Torvalds 已提交
2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454

/*
 * 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))

2455
/*
2456
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470
 * of blocks reserved is based on zone->pages_min. The memory within the
 * reserve will tend to store contiguous free pages. Setting min_free_kbytes
 * 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;
	unsigned long reserve, block_migratetype;

	/* 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;
2471 2472
	reserve = roundup(zone->pages_min, pageblock_nr_pages) >>
							pageblock_order;
2473

2474
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

		/* 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
2509

L
Linus Torvalds 已提交
2510 2511 2512 2513 2514
/*
 * 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.
 */
2515
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
2516
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
2517 2518
{
	struct page *page;
A
Andy Whitcroft 已提交
2519 2520
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
2521
	struct zone *z;
L
Linus Torvalds 已提交
2522

2523
	z = &NODE_DATA(nid)->node_zones[zone];
2524
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535
		/*
		 * 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
2536 2537
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
2538
		mminit_verify_page_links(page, zone, nid, pfn);
2539
		init_page_count(page);
L
Linus Torvalds 已提交
2540 2541
		reset_page_mapcount(page);
		SetPageReserved(page);
2542 2543 2544 2545 2546
		/*
		 * 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
2547 2548 2549
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
2550 2551 2552 2553 2554
		 *
		 * 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.
2555
		 */
2556 2557 2558
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
2559
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2560

L
Linus Torvalds 已提交
2561 2562 2563 2564
		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))
2565
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
2566 2567 2568 2569
#endif
	}
}

2570
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
2571
{
2572 2573 2574
	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
2575 2576 2577 2578 2579 2580
		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
2581
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
2582 2583
#endif

2584
static int zone_batchsize(struct zone *zone)
2585 2586 2587 2588 2589
{
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
2590
	 * size of the zone.  But no more than 1/2 of a meg.
2591 2592 2593 2594
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
2595 2596
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
2597 2598 2599 2600 2601
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
2602 2603 2604
	 * 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.
2605
	 *
2606 2607 2608 2609
	 * 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.
2610
	 */
2611
	batch = (1 << (fls(batch + batch/2)-1)) - 1;
2612

2613 2614 2615
	return batch;
}

2616 2617 2618 2619
inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
{
	struct per_cpu_pages *pcp;

2620 2621
	memset(p, 0, sizeof(*p));

2622
	pcp = &p->pcp;
2623 2624 2625 2626 2627 2628
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
	INIT_LIST_HEAD(&pcp->list);
}

2629 2630 2631 2632 2633 2634 2635 2636 2637 2638
/*
 * 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;

2639
	pcp = &p->pcp;
2640 2641 2642 2643 2644 2645 2646
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}


2647 2648
#ifdef CONFIG_NUMA
/*
2649 2650 2651 2652 2653 2654 2655
 * Boot pageset table. One per cpu which is going to be used for all
 * zones and all nodes. The parameters will be set in such a way
 * that an item put on a list will immediately be handed over to
 * the buddy list. This is safe since pageset manipulation is done
 * with interrupts disabled.
 *
 * Some NUMA counter updates may also be caught by the boot pagesets.
2656 2657 2658 2659 2660 2661 2662 2663
 *
 * 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.
2664
 */
2665
static struct per_cpu_pageset boot_pageset[NR_CPUS];
2666 2667 2668

/*
 * Dynamically allocate memory for the
2669 2670
 * per cpu pageset array in struct zone.
 */
2671
static int __cpuinit process_zones(int cpu)
2672 2673
{
	struct zone *zone, *dzone;
2674 2675 2676
	int node = cpu_to_node(cpu);

	node_set_state(node, N_CPU);	/* this node has a cpu */
2677 2678 2679

	for_each_zone(zone) {

2680 2681 2682
		if (!populated_zone(zone))
			continue;

N
Nick Piggin 已提交
2683
		zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
2684
					 GFP_KERNEL, node);
N
Nick Piggin 已提交
2685
		if (!zone_pcp(zone, cpu))
2686 2687
			goto bad;

N
Nick Piggin 已提交
2688
		setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
2689 2690 2691 2692

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(zone_pcp(zone, cpu),
			 	(zone->present_pages / percpu_pagelist_fraction));
2693 2694 2695 2696 2697
	}

	return 0;
bad:
	for_each_zone(dzone) {
2698 2699
		if (!populated_zone(dzone))
			continue;
2700 2701
		if (dzone == zone)
			break;
N
Nick Piggin 已提交
2702 2703
		kfree(zone_pcp(dzone, cpu));
		zone_pcp(dzone, cpu) = NULL;
2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714
	}
	return -ENOMEM;
}

static inline void free_zone_pagesets(int cpu)
{
	struct zone *zone;

	for_each_zone(zone) {
		struct per_cpu_pageset *pset = zone_pcp(zone, cpu);

2715 2716 2717
		/* Free per_cpu_pageset if it is slab allocated */
		if (pset != &boot_pageset[cpu])
			kfree(pset);
2718 2719 2720 2721
		zone_pcp(zone, cpu) = NULL;
	}
}

2722
static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
2723 2724 2725 2726 2727 2728 2729
		unsigned long action,
		void *hcpu)
{
	int cpu = (long)hcpu;
	int ret = NOTIFY_OK;

	switch (action) {
2730
	case CPU_UP_PREPARE:
2731
	case CPU_UP_PREPARE_FROZEN:
2732 2733 2734 2735
		if (process_zones(cpu))
			ret = NOTIFY_BAD;
		break;
	case CPU_UP_CANCELED:
2736
	case CPU_UP_CANCELED_FROZEN:
2737
	case CPU_DEAD:
2738
	case CPU_DEAD_FROZEN:
2739 2740 2741 2742
		free_zone_pagesets(cpu);
		break;
	default:
		break;
2743 2744 2745 2746
	}
	return ret;
}

2747
static struct notifier_block __cpuinitdata pageset_notifier =
2748 2749
	{ &pageset_cpuup_callback, NULL, 0 };

2750
void __init setup_per_cpu_pageset(void)
2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764
{
	int err;

	/* Initialize per_cpu_pageset for cpu 0.
	 * A cpuup callback will do this for every cpu
	 * as it comes online
	 */
	err = process_zones(smp_processor_id());
	BUG_ON(err);
	register_cpu_notifier(&pageset_notifier);
}

#endif

S
Sam Ravnborg 已提交
2765
static noinline __init_refok
2766
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
2767 2768 2769
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
2770
	size_t alloc_size;
2771 2772 2773 2774 2775

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
2776 2777 2778 2779
	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);
2780 2781 2782
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

2783
	if (!slab_is_available()) {
2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796
		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.
		 */
2797
		zone->wait_table = vmalloc(alloc_size);
2798 2799 2800
	}
	if (!zone->wait_table)
		return -ENOMEM;
2801

2802
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
2803
		init_waitqueue_head(zone->wait_table + i);
2804 2805

	return 0;
2806 2807
}

2808
static __meminit void zone_pcp_init(struct zone *zone)
2809 2810 2811 2812 2813 2814 2815
{
	int cpu;
	unsigned long batch = zone_batchsize(zone);

	for (cpu = 0; cpu < NR_CPUS; cpu++) {
#ifdef CONFIG_NUMA
		/* Early boot. Slab allocator not functional yet */
N
Nick Piggin 已提交
2816
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
2817 2818 2819 2820 2821
		setup_pageset(&boot_pageset[cpu],0);
#else
		setup_pageset(zone_pcp(zone,cpu), batch);
#endif
	}
A
Anton Blanchard 已提交
2822 2823 2824
	if (zone->present_pages)
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%lu\n",
			zone->name, zone->present_pages, batch);
2825 2826
}

2827 2828
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
2829 2830
					unsigned long size,
					enum memmap_context context)
2831 2832
{
	struct pglist_data *pgdat = zone->zone_pgdat;
2833 2834 2835 2836
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
2837 2838 2839 2840
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

2841 2842 2843 2844 2845 2846
	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));

2847
	zone_init_free_lists(zone);
2848 2849

	return 0;
2850 2851
}

2852 2853 2854 2855 2856
#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
 */
2857
static int __meminit first_active_region_index_in_nid(int nid)
2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869
{
	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
2870
 * Note: nid == MAX_NUMNODES returns next region regardless of node
2871
 */
2872
static int __meminit next_active_region_index_in_nid(int index, int nid)
2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887
{
	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
 */
2888
int __meminit early_pfn_to_nid(unsigned long pfn)
2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910
{
	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;
	}

	return 0;
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

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

2940 2941 2942
void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
{
	int i;
2943
	int ret;
2944

2945 2946 2947 2948 2949 2950
	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;
	}
2951
}
2952 2953
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
2954
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
2955 2956 2957
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
2958
 * function may be used instead of calling memory_present() manually.
2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969
 */
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);
}

2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985
/**
 * push_node_boundaries - Push node boundaries to at least the requested boundary
 * @nid: The nid of the node to push the boundary for
 * @start_pfn: The start pfn of the node
 * @end_pfn: The end pfn of the node
 *
 * In reserve-based hot-add, mem_map is allocated that is unused until hotadd
 * time. Specifically, on x86_64, SRAT will report ranges that can potentially
 * be hotplugged even though no physical memory exists. This function allows
 * an arch to push out the node boundaries so mem_map is allocated that can
 * be used later.
 */
#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
void __init push_node_boundaries(unsigned int nid,
		unsigned long start_pfn, unsigned long end_pfn)
{
2986 2987
	mminit_dprintk(MMINIT_TRACE, "zoneboundary",
			"Entering push_node_boundaries(%u, %lu, %lu)\n",
2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001
			nid, start_pfn, end_pfn);

	/* Initialise the boundary for this node if necessary */
	if (node_boundary_end_pfn[nid] == 0)
		node_boundary_start_pfn[nid] = -1UL;

	/* Update the boundaries */
	if (node_boundary_start_pfn[nid] > start_pfn)
		node_boundary_start_pfn[nid] = start_pfn;
	if (node_boundary_end_pfn[nid] < end_pfn)
		node_boundary_end_pfn[nid] = end_pfn;
}

/* If necessary, push the node boundary out for reserve hotadd */
3002
static void __meminit account_node_boundary(unsigned int nid,
3003 3004
		unsigned long *start_pfn, unsigned long *end_pfn)
{
3005 3006
	mminit_dprintk(MMINIT_TRACE, "zoneboundary",
			"Entering account_node_boundary(%u, %lu, %lu)\n",
3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022
			nid, *start_pfn, *end_pfn);

	/* Return if boundary information has not been provided */
	if (node_boundary_end_pfn[nid] == 0)
		return;

	/* Check the boundaries and update if necessary */
	if (node_boundary_start_pfn[nid] < *start_pfn)
		*start_pfn = node_boundary_start_pfn[nid];
	if (node_boundary_end_pfn[nid] > *end_pfn)
		*end_pfn = node_boundary_end_pfn[nid];
}
#else
void __init push_node_boundaries(unsigned int nid,
		unsigned long start_pfn, unsigned long end_pfn) {}

3023
static void __meminit account_node_boundary(unsigned int nid,
3024 3025 3026 3027
		unsigned long *start_pfn, unsigned long *end_pfn) {}
#endif


3028 3029
/**
 * get_pfn_range_for_nid - Return the start and end page frames for a node
3030 3031 3032
 * @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.
3033 3034 3035 3036
 *
 * 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
3037
 * PFNs will be 0.
3038
 */
3039
void __meminit get_pfn_range_for_nid(unsigned int nid,
3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050
			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);
	}

3051
	if (*start_pfn == -1UL)
3052
		*start_pfn = 0;
3053 3054 3055

	/* Push the node boundaries out if requested */
	account_node_boundary(nid, start_pfn, end_pfn);
3056 3057
}

M
Mel Gorman 已提交
3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114
/*
 * 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
 */
void __init find_usable_zone_for_movable(void)
{
	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
 */
void __meminit adjust_zone_range_for_zone_movable(int nid,
					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;
	}
}

3115 3116 3117 3118
/*
 * 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
3119
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3120 3121 3122 3123 3124 3125 3126 3127 3128 3129
					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
3130 3131 3132
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147

	/* 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,
3148
 * then all holes in the requested range will be accounted for.
3149
 */
3150
unsigned long __meminit __absent_pages_in_range(int nid,
3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162
				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;

3163 3164
	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);

3165 3166
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
3167
		hole_pages = prev_end_pfn - range_start_pfn;
3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187

	/* 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;
	}

3188 3189
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
3190
		hole_pages += range_end_pfn -
3191 3192
				max(range_start_pfn, prev_end_pfn);

3193 3194 3195 3196 3197 3198 3199 3200
	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
 *
3201
 * It returns the number of pages frames in memory holes within a range.
3202 3203 3204 3205 3206 3207 3208 3209
 */
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
3210
static unsigned long __meminit zone_absent_pages_in_node(int nid,
3211 3212 3213
					unsigned long zone_type,
					unsigned long *ignored)
{
3214 3215 3216 3217 3218 3219 3220 3221 3222
	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
3223 3224 3225
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
3226
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3227
}
3228

3229
#else
P
Paul Mundt 已提交
3230
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3231 3232 3233 3234 3235 3236
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
3237
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3238 3239 3240 3241 3242 3243 3244 3245
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
3246

3247 3248
#endif

3249
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269
		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);
}

3270 3271 3272
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
3273 3274
 * 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
3275 3276 3277 3278 3279 3280 3281
 * 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;

3282 3283
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304
	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;
	if (usemapsize) {
		zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize);
		memset(zone->pageblock_flags, 0, usemapsize);
	}
}
#else
static void inline setup_usemap(struct pglist_data *pgdat,
				struct zone *zone, unsigned long zonesize) {}
#endif /* CONFIG_SPARSEMEM */

3305
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3306 3307 3308 3309 3310 3311 3312 3313 3314 3315

/* 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;
}

3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330
/* 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 */

3331 3332 3333 3334 3335 3336 3337 3338 3339 3340
/*
 * 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;
}
3341 3342 3343 3344
#define set_pageblock_order(x)	do {} while (0)

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
3345 3346 3347 3348 3349 3350
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
3351
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3352 3353
		unsigned long *zones_size, unsigned long *zholes_size)
{
3354
	enum zone_type j;
3355
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
3356
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
3357
	int ret;
L
Linus Torvalds 已提交
3358

3359
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
3360 3361 3362 3363 3364 3365
	pgdat->nr_zones = 0;
	init_waitqueue_head(&pgdat->kswapd_wait);
	pgdat->kswapd_max_order = 0;
	
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
3366
		unsigned long size, realsize, memmap_pages;
L
Linus Torvalds 已提交
3367

3368 3369 3370
		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
3371

3372 3373 3374 3375 3376
		/*
		 * 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
		 */
3377 3378
		memmap_pages =
			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
3379 3380
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
3381 3382
			mminit_dprintk(MMINIT_TRACE, "memmap_init",
				"%s zone: %lu pages used for memmap\n",
3383 3384 3385 3386 3387 3388
				zone_names[j], memmap_pages);
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

3389 3390
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
3391
			realsize -= dma_reserve;
3392 3393
			mminit_dprintk(MMINIT_TRACE, "memmap_init",
					"%s zone: %lu pages reserved\n",
3394
					zone_names[0], dma_reserve);
3395 3396
		}

3397
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
3398 3399 3400 3401 3402
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
3403
#ifdef CONFIG_NUMA
3404
		zone->node = nid;
3405
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3406
						/ 100;
3407
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3408
#endif
L
Linus Torvalds 已提交
3409 3410 3411
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
3412
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
3413 3414
		zone->zone_pgdat = pgdat;

3415
		zone->prev_priority = DEF_PRIORITY;
L
Linus Torvalds 已提交
3416

3417
		zone_pcp_init(zone);
L
Linus Torvalds 已提交
3418 3419 3420 3421
		INIT_LIST_HEAD(&zone->active_list);
		INIT_LIST_HEAD(&zone->inactive_list);
		zone->nr_scan_active = 0;
		zone->nr_scan_inactive = 0;
3422
		zap_zone_vm_stats(zone);
3423
		zone->flags = 0;
L
Linus Torvalds 已提交
3424 3425 3426
		if (!size)
			continue;

3427
		set_pageblock_order(pageblock_default_order());
3428
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
3429 3430
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
3431
		BUG_ON(ret);
3432
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
3433 3434 3435 3436
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
3437
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
3438 3439 3440 3441 3442
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
3443
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
3444 3445
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
3446
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
3447 3448
		struct page *map;

3449 3450 3451 3452 3453 3454 3455 3456 3457
		/*
		 * 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);
3458 3459 3460
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
3461
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
3462
	}
3463
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
3464 3465 3466
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
3467
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
3468
		mem_map = NODE_DATA(0)->node_mem_map;
3469 3470
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3471
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3472 3473
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
3474
#endif
A
Andy Whitcroft 已提交
3475
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
3476 3477
}

3478
void __paginginit free_area_init_node(int nid, struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3479 3480 3481 3482 3483
		unsigned long *zones_size, unsigned long node_start_pfn,
		unsigned long *zholes_size)
{
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
3484
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
3485 3486

	alloc_node_mem_map(pgdat);
3487 3488 3489 3490 3491
#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
3492 3493 3494 3495

	free_area_init_core(pgdat, zones_size, zholes_size);
}

3496
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
M
Miklos Szeredi 已提交
3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516

#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

3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533
/**
 * 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;

3534 3535 3536 3537 3538
	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);
3539

3540 3541
	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);

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 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580
	/* Merge with existing active regions if possible */
	for (i = 0; i < nr_nodemap_entries; i++) {
		if (early_node_map[i].nid != nid)
			continue;

		/* Skip if an existing region covers this new one */
		if (start_pfn >= early_node_map[i].start_pfn &&
				end_pfn <= early_node_map[i].end_pfn)
			return;

		/* Merge forward if suitable */
		if (start_pfn <= early_node_map[i].end_pfn &&
				end_pfn > early_node_map[i].end_pfn) {
			early_node_map[i].end_pfn = end_pfn;
			return;
		}

		/* Merge backward if suitable */
		if (start_pfn < early_node_map[i].end_pfn &&
				end_pfn >= early_node_map[i].start_pfn) {
			early_node_map[i].start_pfn = start_pfn;
			return;
		}
	}

	/* Check that early_node_map is large enough */
	if (i >= MAX_ACTIVE_REGIONS) {
		printk(KERN_CRIT "More than %d memory regions, truncating\n",
							MAX_ACTIVE_REGIONS);
		return;
	}

	early_node_map[i].nid = nid;
	early_node_map[i].start_pfn = start_pfn;
	early_node_map[i].end_pfn = end_pfn;
	nr_nodemap_entries = i + 1;
}

/**
3581
 * remove_active_range - Shrink an existing registered range of PFNs
3582
 * @nid: The node id the range is on that should be shrunk
3583 3584
 * @start_pfn: The new PFN of the range
 * @end_pfn: The new PFN of the range
3585 3586
 *
 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
3587 3588 3589
 * 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.
3590
 */
3591 3592
void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
				unsigned long end_pfn)
3593
{
3594 3595
	int i, j;
	int removed = 0;
3596

3597 3598 3599
	printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
			  nid, start_pfn, end_pfn);

3600
	/* Find the old active region end and shrink */
3601
	for_each_active_range_index_in_nid(i, nid) {
3602 3603
		if (early_node_map[i].start_pfn >= start_pfn &&
		    early_node_map[i].end_pfn <= end_pfn) {
3604
			/* clear it */
3605
			early_node_map[i].start_pfn = 0;
3606 3607 3608 3609
			early_node_map[i].end_pfn = 0;
			removed = 1;
			continue;
		}
3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621
		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;
3622
			continue;
3623
		}
3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642
	}

	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--;
	}
3643 3644 3645 3646
}

/**
 * remove_all_active_ranges - Remove all currently registered regions
3647
 *
3648 3649 3650 3651
 * 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.
 */
3652
void __init remove_all_active_ranges(void)
3653 3654 3655
{
	memset(early_node_map, 0, sizeof(early_node_map));
	nr_nodemap_entries = 0;
3656 3657 3658 3659
#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
	memset(node_boundary_start_pfn, 0, sizeof(node_boundary_start_pfn));
	memset(node_boundary_end_pfn, 0, sizeof(node_boundary_end_pfn));
#endif /* CONFIG_MEMORY_HOTPLUG_RESERVE */
3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684
}

/* Compare two active node_active_regions */
static int __init cmp_node_active_region(const void *a, const void *b)
{
	struct node_active_region *arange = (struct node_active_region *)a;
	struct node_active_region *brange = (struct node_active_region *)b;

	/* Done this way to avoid overflows */
	if (arange->start_pfn > brange->start_pfn)
		return 1;
	if (arange->start_pfn < brange->start_pfn)
		return -1;

	return 0;
}

/* sort the node_map by start_pfn */
static void __init sort_node_map(void)
{
	sort(early_node_map, (size_t)nr_nodemap_entries,
			sizeof(struct node_active_region),
			cmp_node_active_region, NULL);
}

3685
/* Find the lowest pfn for a node */
3686
unsigned long __init find_min_pfn_for_node(int nid)
3687 3688
{
	int i;
3689
	unsigned long min_pfn = ULONG_MAX;
3690

3691 3692
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
3693
		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
3694

3695 3696
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
3697
			"Could not find start_pfn for node %d\n", nid);
3698 3699 3700 3701
		return 0;
	}

	return min_pfn;
3702 3703 3704 3705 3706 3707
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
3708
 * add_active_range().
3709 3710 3711 3712 3713 3714 3715 3716 3717 3718
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

/**
 * find_max_pfn_with_active_regions - Find the maximum PFN registered
 *
 * It returns the maximum PFN based on information provided via
3719
 * add_active_range().
3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730 3731
 */
unsigned long __init find_max_pfn_with_active_regions(void)
{
	int i;
	unsigned long max_pfn = 0;

	for (i = 0; i < nr_nodemap_entries; i++)
		max_pfn = max(max_pfn, early_node_map[i].end_pfn);

	return max_pfn;
}

3732 3733 3734 3735 3736
/*
 * 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
3737
static unsigned long __init early_calculate_totalpages(void)
3738 3739 3740 3741
{
	int i;
	unsigned long totalpages = 0;

3742 3743
	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long pages = early_node_map[i].end_pfn -
3744
						early_node_map[i].start_pfn;
3745 3746 3747 3748 3749
		totalpages += pages;
		if (pages)
			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
	}
  	return totalpages;
3750 3751
}

M
Mel Gorman 已提交
3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762
/*
 * 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
 */
void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
3763 3764
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
3765

3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787
	/*
	 * 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);
	}

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3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798
	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
	if (!required_kernelcore)
		return;

	/* 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;
3799
	for_each_node_state(nid, N_HIGH_MEMORY) {
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3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890
		/*
		 * 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);
}

3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904
/* 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
}

3905 3906
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
3907
 * @max_zone_pfn: an array of max PFNs for each zone
3908 3909 3910 3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922
 *
 * 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;
	enum zone_type i;

3923 3924 3925
	/* Sort early_node_map as initialisation assumes it is sorted */
	sort_node_map();

3926 3927 3928 3929 3930 3931 3932 3933
	/* 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
3934 3935
		if (i == ZONE_MOVABLE)
			continue;
3936 3937 3938 3939 3940
		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
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3941 3942 3943 3944 3945 3946
	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);
3947 3948 3949

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
M
Mel Gorman 已提交
3950 3951 3952
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
3953
		printk("  %-8s %0#10lx -> %0#10lx\n",
3954 3955 3956
				zone_names[i],
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);
M
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3957 3958 3959 3960 3961 3962 3963 3964
	}

	/* 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]);
	}
3965 3966 3967 3968

	/* 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++)
3969
		printk("  %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
3970 3971 3972 3973
						early_node_map[i].start_pfn,
						early_node_map[i].end_pfn);

	/* Initialise every node */
3974
	mminit_verify_pageflags_layout();
3975
	setup_nr_node_ids();
3976 3977 3978 3979
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
		free_area_init_node(nid, pgdat, NULL,
				find_min_pfn_for_node(nid), NULL);
3980 3981 3982 3983 3984

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
3985 3986
	}
}
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Mel Gorman 已提交
3987

3988
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
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3989 3990 3991 3992 3993 3994
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
3995
	*core = coremem >> PAGE_SHIFT;
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3996

3997
	/* Paranoid check that UL is enough for the coremem value */
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3998 3999 4000 4001
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
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4002

4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020
/*
 * 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);
}

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4021
early_param("kernelcore", cmdline_parse_kernelcore);
4022
early_param("movablecore", cmdline_parse_movablecore);
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4023

4024 4025
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

4026
/**
4027 4028
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
4029 4030 4031 4032
 *
 * 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
4033 4034 4035
 * 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.
4036 4037 4038 4039 4040 4041
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

4042
#ifndef CONFIG_NEED_MULTIPLE_NODES
4043
struct pglist_data contig_page_data = { .bdata = &bootmem_node_data[0] };
L
Linus Torvalds 已提交
4044
EXPORT_SYMBOL(contig_page_data);
4045
#endif
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4046 4047 4048

void __init free_area_init(unsigned long *zones_size)
{
4049
	free_area_init_node(0, NODE_DATA(0), zones_size,
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Linus Torvalds 已提交
4050 4051 4052 4053 4054 4055 4056 4057
			__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;

4058
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
4059 4060 4061 4062 4063 4064 4065 4066
		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.
		 */
4067
		vm_events_fold_cpu(cpu);
4068 4069 4070 4071 4072 4073 4074 4075

		/*
		 * 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.
		 */
4076
		refresh_cpu_vm_stats(cpu);
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4077 4078 4079 4080 4081 4082 4083 4084 4085
	}
	return NOTIFY_OK;
}

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

4086 4087 4088 4089 4090 4091 4092 4093
/*
 * 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;
4094
	enum zone_type i, j;
4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113 4114 4115 4116 4117

	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];
			}

			/* we treat pages_high as reserved pages. */
			max += zone->pages_high;

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

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4118 4119 4120 4121 4122 4123 4124 4125 4126
/*
 * 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;
4127
	enum zone_type j, idx;
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4128

4129
	for_each_online_pgdat(pgdat) {
L
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4130 4131 4132 4133 4134 4135
		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;

4136 4137
			idx = j;
			while (idx) {
L
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4138 4139
				struct zone *lower_zone;

4140 4141
				idx--;

L
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4142 4143 4144 4145 4146 4147 4148 4149 4150 4151
				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;
			}
		}
	}
4152 4153 4154

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
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4155 4156
}

4157 4158 4159 4160 4161
/**
 * setup_per_zone_pages_min - called when min_free_kbytes changes.
 *
 * Ensures that the pages_{min,low,high} values for each zone are set correctly
 * with respect to min_free_kbytes.
L
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4162
 */
4163
void setup_per_zone_pages_min(void)
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4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176
{
	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) {
4177 4178
		u64 tmp;

L
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4179
		spin_lock_irqsave(&zone->lru_lock, flags);
4180 4181
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
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4182 4183
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
4184 4185 4186 4187 4188 4189 4190
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
			 * The (pages_high-pages_low) and (pages_low-pages_min)
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
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4191 4192 4193 4194 4195 4196 4197 4198 4199 4200
			 */
			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;
			zone->pages_min = min_pages;
		} else {
N
Nick Piggin 已提交
4201 4202
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
4203 4204
			 * proportionate to the zone's size.
			 */
N
Nick Piggin 已提交
4205
			zone->pages_min = tmp;
L
Linus Torvalds 已提交
4206 4207
		}

4208 4209
		zone->pages_low   = zone->pages_min + (tmp >> 2);
		zone->pages_high  = zone->pages_min + (tmp >> 1);
4210
		setup_zone_migrate_reserve(zone);
L
Linus Torvalds 已提交
4211 4212
		spin_unlock_irqrestore(&zone->lru_lock, flags);
	}
4213 4214 4215

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
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4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267
}

/*
 * 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
 */
static int __init init_per_zone_pages_min(void)
{
	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;
	setup_per_zone_pages_min();
	setup_per_zone_lowmem_reserve();
	return 0;
}
module_init(init_per_zone_pages_min)

/*
 * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so 
 *	that we can call two helper functions whenever min_free_kbytes
 *	changes.
 */
int min_free_kbytes_sysctl_handler(ctl_table *table, int write, 
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	proc_dointvec(table, write, file, buffer, length, ppos);
4268 4269
	if (write)
		setup_per_zone_pages_min();
L
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4270 4271 4272
	return 0;
}

4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284
#ifdef CONFIG_NUMA
int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	struct zone *zone;
	int rc;

	rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
	if (rc)
		return rc;

	for_each_zone(zone)
4285
		zone->min_unmapped_pages = (zone->present_pages *
4286 4287 4288
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
4289 4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302 4303 4304

int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	struct zone *zone;
	int rc;

	rc = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
	if (rc)
		return rc;

	for_each_zone(zone)
		zone->min_slab_pages = (zone->present_pages *
				sysctl_min_slab_ratio) / 100;
	return 0;
}
4305 4306
#endif

L
Linus Torvalds 已提交
4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323
/*
 * 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
 * pages_min watermarks. The lowmem reserve ratio can only make sense
 * if in function of the boot time zone sizes.
 */
int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	proc_dointvec_minmax(table, write, file, buffer, length, ppos);
	setup_per_zone_lowmem_reserve();
	return 0;
}

4324 4325 4326 4327 4328 4329 4330 4331 4332 4333 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349
/*
 * percpu_pagelist_fraction - changes the pcp->high for each zone on each
 * cpu.  It is the fraction of total pages in each zone that a hot per cpu pagelist
 * can have before it gets flushed back to buddy allocator.
 */

int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
	struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
{
	struct zone *zone;
	unsigned int cpu;
	int ret;

	ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
	if (!write || (ret == -EINVAL))
		return ret;
	for_each_zone(zone) {
		for_each_online_cpu(cpu) {
			unsigned long  high;
			high = zone->present_pages / percpu_pagelist_fraction;
			setup_pagelist_highmark(zone_pcp(zone, cpu), high);
		}
	}
	return 0;
}

4350
int hashdist = HASHDIST_DEFAULT;
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#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 */
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4385
		numentries = nr_kernel_pages;
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		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);
4395 4396 4397 4398

		/* Make sure we've got at least a 0-order allocation.. */
		if (unlikely((numentries * bucketsize) < PAGE_SIZE))
			numentries = PAGE_SIZE / bucketsize;
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Linus Torvalds 已提交
4399
	}
4400
	numentries = roundup_pow_of_two(numentries);
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	/* 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;

4411
	log2qty = ilog2(numentries);
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4412 4413 4414 4415 4416 4417 4418 4419

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
			table = alloc_bootmem(size);
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
4420
			unsigned long order = get_order(size);
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Linus Torvalds 已提交
4421
			table = (void*) __get_free_pages(GFP_ATOMIC, order);
4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436
			/*
			 * If bucketsize is not a power-of-two, we may free
			 * some pages at the end of hash table.
			 */
			if (table) {
				unsigned long alloc_end = (unsigned long)table +
						(PAGE_SIZE << order);
				unsigned long used = (unsigned long)table +
						PAGE_ALIGN(size);
				split_page(virt_to_page(table), order);
				while (used < alloc_end) {
					free_page(used);
					used += PAGE_SIZE;
				}
			}
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Linus Torvalds 已提交
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		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

4443
	printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
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Linus Torvalds 已提交
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	       tablename,
	       (1U << log2qty),
4446
	       ilog2(size) - PAGE_SHIFT,
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	       size);

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

	return table;
}
4456 4457 4458 4459

#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
struct page *pfn_to_page(unsigned long pfn)
{
4460
	return __pfn_to_page(pfn);
4461 4462 4463
}
unsigned long page_to_pfn(struct page *page)
{
4464
	return __page_to_pfn(page);
4465 4466 4467 4468
}
EXPORT_SYMBOL(pfn_to_page);
EXPORT_SYMBOL(page_to_pfn);
#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
4469

4470 4471 4472 4473 4474 4475 4476 4477 4478 4479 4480 4481 4482 4483 4484
/* 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);
4485
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4486 4487
#else
	pfn = pfn - zone->zone_start_pfn;
4488
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4489 4490 4491 4492
#endif /* CONFIG_SPARSEMEM */
}

/**
4493
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4494 4495 4496 4497 4498 4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515
 * @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;
4516

4517 4518 4519 4520
	return flags;
}

/**
4521
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4522 4523 4524 4525 4526 4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538
 * @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);
4539 4540
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
4541 4542 4543 4544 4545 4546 4547

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

int set_migratetype_isolate(struct page *page)
{
	struct zone *zone;
	unsigned long flags;
	int ret = -EBUSY;

	zone = page_zone(page);
	spin_lock_irqsave(&zone->lock, flags);
	/*
	 * In future, more migrate types will be able to be isolation target.
	 */
	if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE)
		goto out;
	set_pageblock_migratetype(page, MIGRATE_ISOLATE);
	move_freepages_block(zone, page, MIGRATE_ISOLATE);
	ret = 0;
out:
	spin_unlock_irqrestore(&zone->lock, flags);
	if (!ret)
4574
		drain_all_pages();
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KAMEZAWA Hiroyuki 已提交
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	return ret;
}

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