page_alloc.c 122.9 KB
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/*
 *  linux/mm/page_alloc.c
 *
 *  Manages the free list, the system allocates free pages here.
 *  Note that kmalloc() lives in slab.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *  Swap reorganised 29.12.95, Stephen Tweedie
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *  Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
 *  Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
 *  Zone balancing, Kanoj Sarcar, SGI, Jan 2000
 *  Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
 *          (lots of bits borrowed from Ingo Molnar & Andrew Morton)
 */

#include <linux/stddef.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/interrupt.h>
#include <linux/pagemap.h>
#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 <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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	printk(KERN_EMERG "Bad page state in process '%s'\n"
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		KERN_EMERG "page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n"
		KERN_EMERG "Trying to fix it up, but a reboot is needed\n"
		KERN_EMERG "Backtrace:\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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	dump_stack();
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	page->flags &= ~(1 << PG_lru	|
			1 << PG_private |
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			1 << PG_locked	|
			1 << PG_active	|
			1 << PG_dirty	|
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			1 << PG_reclaim |
			1 << PG_slab    |
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			1 << PG_swapcache |
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			1 << PG_writeback |
			1 << PG_buddy );
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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)  |
		(page_count(page) != 0)  |
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		(page->flags & (
			1 << PG_lru	|
			1 << PG_private |
			1 << PG_locked	|
			1 << PG_active	|
			1 << PG_slab	|
			1 << PG_swapcache |
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			1 << PG_writeback |
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			1 << PG_reserved |
			1 << PG_buddy ))))
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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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522
		reserved += free_pages_check(page + i);
523 524 525
	if (reserved)
		return;

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526 527
	if (!PageHighMem(page))
		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
N
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528
	arch_free_page(page, order);
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529
	kernel_map_pages(page, 1 << order, 0);
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530

N
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531
	local_irq_save(flags);
532
	__count_vm_events(PGFREE, 1 << order);
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533
	free_one_page(page_zone(page), page, order);
N
Nick Piggin 已提交
534
	local_irq_restore(flags);
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Linus Torvalds 已提交
535 536
}

537 538 539 540 541 542 543 544
/*
 * permit the bootmem allocator to evade page validation on high-order frees
 */
void fastcall __init __free_pages_bootmem(struct page *page, unsigned int order)
{
	if (order == 0) {
		__ClearPageReserved(page);
		set_page_count(page, 0);
545
		set_page_refcounted(page);
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Nick Piggin 已提交
546
		__free_page(page);
547 548 549
	} else {
		int loop;

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Nick Piggin 已提交
550
		prefetchw(page);
551 552 553
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

N
Nick Piggin 已提交
554 555
			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
556 557 558 559
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

560
		set_page_refcounted(page);
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561
		__free_pages(page, order);
562 563 564
	}
}

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565 566 567 568 569 570 571 572 573 574 575 576 577 578 579

/*
 * 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
 */
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580
static inline void expand(struct zone *zone, struct page *page,
581 582
	int low, int high, struct free_area *area,
	int migratetype)
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583 584 585 586 587 588 589
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
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		VM_BUG_ON(bad_range(zone, &page[size]));
591
		list_add(&page[size].lru, &area->free_list[migratetype]);
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592 593 594 595 596 597 598 599
		area->nr_free++;
		set_page_order(&page[size], high);
	}
}

/*
 * This page is about to be returned from the page allocator
 */
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600
static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
L
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601
{
N
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602 603 604
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
		(page_count(page) != 0)  |
605 606
		(page->flags & (
			1 << PG_lru	|
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			1 << PG_private	|
			1 << PG_locked	|
			1 << PG_active	|
			1 << PG_dirty	|
611
			1 << PG_slab    |
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			1 << PG_swapcache |
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			1 << PG_writeback |
614 615
			1 << PG_reserved |
			1 << PG_buddy ))))
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616
		bad_page(page);
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617

618 619 620 621 622 623 624
	/*
	 * 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;

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Fengguang Wu 已提交
625
	page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_readahead |
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626
			1 << PG_referenced | 1 << PG_arch_1 |
627
			1 << PG_owner_priv_1 | 1 << PG_mappedtodisk);
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628
	set_page_private(page, 0);
629
	set_page_refcounted(page);
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Nick Piggin 已提交
630 631

	arch_alloc_page(page, order);
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	kernel_map_pages(page, 1 << order, 1);
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633 634 635 636 637 638 639

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

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

640
	return 0;
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641 642
}

643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673
/*
 * 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;
}


674 675 676 677 678
/*
 * 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] = {
679 680 681 682
	[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 */
683 684
};

685 686
/*
 * Move the free pages in a range to the free lists of the requested type.
687
 * Note that start_page and end_pages are not aligned on a pageblock
688 689 690 691 692 693 694 695
 * 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;
696
	int pages_moved = 0;
697 698 699 700 701 702 703

#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
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	 * grouping pages by mobility
705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724
	 */
	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;
725
		pages_moved += 1 << order;
726 727
	}

728
	return pages_moved;
729 730 731 732 733 734 735 736
}

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);
737
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
738
	start_page = pfn_to_page(start_pfn);
739 740
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
741 742 743 744 745 746 747 748 749 750

	/* 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);
}

751 752 753 754 755 756 757 758 759 760 761 762 763 764 765
/* 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];

766 767 768
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
				continue;
M
Mel Gorman 已提交
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770 771 772 773 774 775 776 777 778
			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--;

			/*
779
			 * If breaking a large block of pages, move all free
780 781 782
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
			 * agressive about taking ownership of free pages
783
			 */
784
			if (unlikely(current_order >= (pageblock_order >> 1)) ||
785 786 787 788 789 790
					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 */
791
				if (pages >= (1 << (pageblock_order-1)))
792 793 794
					set_pageblock_migratetype(page,
								start_migratetype);

795
				migratetype = start_migratetype;
796
			}
797 798 799 800 801 802 803

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

804
			if (current_order == pageblock_order)
805 806 807 808 809 810 811 812
				set_pageblock_migratetype(page,
							start_migratetype);

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

813 814
	/* Use MIGRATE_RESERVE rather than fail an allocation */
	return __rmqueue_smallest(zone, order, MIGRATE_RESERVE);
815 816
}

817
/*
L
Linus Torvalds 已提交
818 819 820
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
821 822
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
L
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823 824 825
{
	struct page *page;

826
	page = __rmqueue_smallest(zone, order, migratetype);
827

828 829
	if (unlikely(!page))
		page = __rmqueue_fallback(zone, order, migratetype);
830 831

	return page;
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Linus Torvalds 已提交
832 833 834 835 836 837 838 839
}

/* 
 * 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, 
840 841
			unsigned long count, struct list_head *list,
			int migratetype)
L
Linus Torvalds 已提交
842 843 844
{
	int i;
	
N
Nick Piggin 已提交
845
	spin_lock(&zone->lock);
L
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846
	for (i = 0; i < count; ++i) {
847
		struct page *page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
848
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
849
			break;
850 851
		list_add(&page->lru, list);
		set_page_private(page, migratetype);
L
Linus Torvalds 已提交
852
	}
N
Nick Piggin 已提交
853
	spin_unlock(&zone->lock);
N
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854
	return i;
L
Linus Torvalds 已提交
855 856
}

857
#ifdef CONFIG_NUMA
858
/*
859 860 861 862
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
863 864
 * Note that this function must be called with the thread pinned to
 * a single processor.
865
 */
866
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
867 868
{
	unsigned long flags;
869
	int to_drain;
870

871 872 873 874 875 876 877 878
	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);
879 880 881
}
#endif

L
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882 883
static void __drain_pages(unsigned int cpu)
{
N
Nick Piggin 已提交
884
	unsigned long flags;
L
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885 886 887 888 889 890
	struct zone *zone;
	int i;

	for_each_zone(zone) {
		struct per_cpu_pageset *pset;

891 892 893
		if (!populated_zone(zone))
			continue;

894
		pset = zone_pcp(zone, cpu);
L
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895 896 897 898
		for (i = 0; i < ARRAY_SIZE(pset->pcp); i++) {
			struct per_cpu_pages *pcp;

			pcp = &pset->pcp[i];
N
Nick Piggin 已提交
899
			local_irq_save(flags);
N
Nick Piggin 已提交
900 901
			free_pages_bulk(zone, pcp->count, &pcp->list, 0);
			pcp->count = 0;
N
Nick Piggin 已提交
902
			local_irq_restore(flags);
L
Linus Torvalds 已提交
903 904 905 906
		}
	}
}

907
#ifdef CONFIG_HIBERNATION
L
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908 909 910

void mark_free_pages(struct zone *zone)
{
911 912
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
913
	int order, t;
L
Linus Torvalds 已提交
914 915 916 917 918 919
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
920 921 922 923 924 925

	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);

926 927
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
928
		}
L
Linus Torvalds 已提交
929

930 931
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
932
			unsigned long i;
L
Linus Torvalds 已提交
933

934 935
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
936
				swsusp_set_page_free(pfn_to_page(pfn + i));
937
		}
938
	}
L
Linus Torvalds 已提交
939 940
	spin_unlock_irqrestore(&zone->lock, flags);
}
941
#endif /* CONFIG_PM */
L
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942 943 944 945 946 947 948 949 950 951 952 953

/*
 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
 */
void drain_local_pages(void)
{
	unsigned long flags;

	local_irq_save(flags);	
	__drain_pages(smp_processor_id());
	local_irq_restore(flags);	
}
954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972

void smp_drain_local_pages(void *arg)
{
	drain_local_pages();
}

/*
 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
 */
void drain_all_local_pages(void)
{
	unsigned long flags;

	local_irq_save(flags);
	__drain_pages(smp_processor_id());
	local_irq_restore(flags);

	smp_call_function(smp_drain_local_pages, NULL, 0, 1);
}
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973 974 975 976 977 978 979 980 981 982 983 984

/*
 * Free a 0-order page
 */
static void fastcall free_hot_cold_page(struct page *page, int cold)
{
	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
985
	if (free_pages_check(page))
986 987
		return;

N
Nick Piggin 已提交
988 989
	if (!PageHighMem(page))
		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
N
Nick Piggin 已提交
990
	arch_free_page(page, 0);
991 992
	kernel_map_pages(page, 1, 0);

993
	pcp = &zone_pcp(zone, get_cpu())->pcp[cold];
L
Linus Torvalds 已提交
994
	local_irq_save(flags);
995
	__count_vm_event(PGFREE);
L
Linus Torvalds 已提交
996
	list_add(&page->lru, &pcp->list);
997
	set_page_private(page, get_pageblock_migratetype(page));
L
Linus Torvalds 已提交
998
	pcp->count++;
N
Nick Piggin 已提交
999 1000 1001 1002
	if (pcp->count >= pcp->high) {
		free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
		pcp->count -= pcp->batch;
	}
L
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1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016
	local_irq_restore(flags);
	put_cpu();
}

void fastcall free_hot_page(struct page *page)
{
	free_hot_cold_page(page, 0);
}
	
void fastcall free_cold_page(struct page *page)
{
	free_hot_cold_page(page, 1);
}

N
Nick Piggin 已提交
1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028
/*
 * 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
1029 1030
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1031 1032
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
1033 1034
}

L
Linus Torvalds 已提交
1035 1036 1037 1038 1039
/*
 * 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.
 */
N
Nick Piggin 已提交
1040 1041
static struct page *buffered_rmqueue(struct zonelist *zonelist,
			struct zone *zone, int order, gfp_t gfp_flags)
L
Linus Torvalds 已提交
1042 1043
{
	unsigned long flags;
1044
	struct page *page;
L
Linus Torvalds 已提交
1045
	int cold = !!(gfp_flags & __GFP_COLD);
N
Nick Piggin 已提交
1046
	int cpu;
1047
	int migratetype = allocflags_to_migratetype(gfp_flags);
L
Linus Torvalds 已提交
1048

1049
again:
N
Nick Piggin 已提交
1050
	cpu  = get_cpu();
N
Nick Piggin 已提交
1051
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1052 1053
		struct per_cpu_pages *pcp;

N
Nick Piggin 已提交
1054
		pcp = &zone_pcp(zone, cpu)->pcp[cold];
L
Linus Torvalds 已提交
1055
		local_irq_save(flags);
N
Nick Piggin 已提交
1056
		if (!pcp->count) {
1057
			pcp->count = rmqueue_bulk(zone, 0,
1058
					pcp->batch, &pcp->list, migratetype);
N
Nick Piggin 已提交
1059 1060
			if (unlikely(!pcp->count))
				goto failed;
L
Linus Torvalds 已提交
1061
		}
1062

1063
		/* Find a page of the appropriate migrate type */
1064 1065
		list_for_each_entry(page, &pcp->list, lru)
			if (page_private(page) == migratetype)
1066 1067
				break;

1068 1069
		/* Allocate more to the pcp list if necessary */
		if (unlikely(&page->lru == &pcp->list)) {
1070 1071 1072 1073
			pcp->count += rmqueue_bulk(zone, 0,
					pcp->batch, &pcp->list, migratetype);
			page = list_entry(pcp->list.next, struct page, lru);
		}
1074 1075 1076

		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1077
	} else {
L
Linus Torvalds 已提交
1078
		spin_lock_irqsave(&zone->lock, flags);
1079
		page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1080 1081 1082
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
L
Linus Torvalds 已提交
1083 1084
	}

1085
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1086
	zone_statistics(zonelist, zone);
N
Nick Piggin 已提交
1087 1088
	local_irq_restore(flags);
	put_cpu();
L
Linus Torvalds 已提交
1089

N
Nick Piggin 已提交
1090
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1091
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1092
		goto again;
L
Linus Torvalds 已提交
1093
	return page;
N
Nick Piggin 已提交
1094 1095 1096 1097 1098

failed:
	local_irq_restore(flags);
	put_cpu();
	return NULL;
L
Linus Torvalds 已提交
1099 1100
}

R
Rohit Seth 已提交
1101
#define ALLOC_NO_WATERMARKS	0x01 /* don't check watermarks at all */
1102 1103 1104 1105 1106 1107
#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
1108

1109 1110 1111 1112 1113 1114 1115
#ifdef CONFIG_FAIL_PAGE_ALLOC

static struct fail_page_alloc_attr {
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1116
	u32 min_order;
1117 1118 1119 1120 1121

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

	struct dentry *ignore_gfp_highmem_file;
	struct dentry *ignore_gfp_wait_file;
1122
	struct dentry *min_order_file;
1123 1124 1125 1126 1127

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1128 1129
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1130
	.min_order = 1,
1131 1132 1133 1134 1135 1136 1137 1138 1139 1140
};

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)
{
1141 1142
	if (order < fail_page_alloc.min_order)
		return 0;
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 1171 1172 1173
	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);
1174 1175 1176
	fail_page_alloc.min_order_file =
		debugfs_create_u32("min-order", mode, dir,
				   &fail_page_alloc.min_order);
1177 1178

	if (!fail_page_alloc.ignore_gfp_wait_file ||
1179 1180
            !fail_page_alloc.ignore_gfp_highmem_file ||
            !fail_page_alloc.min_order_file) {
1181 1182 1183
		err = -ENOMEM;
		debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
		debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1184
		debugfs_remove(fail_page_alloc.min_order_file);
1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203
		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
1204 1205 1206 1207 1208
/*
 * 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
1209
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
1210 1211
{
	/* free_pages my go negative - that's OK */
1212 1213
	long min = mark;
	long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
L
Linus Torvalds 已提交
1214 1215
	int o;

R
Rohit Seth 已提交
1216
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1217
		min -= min / 2;
R
Rohit Seth 已提交
1218
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235
		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;
}

1236 1237 1238 1239 1240 1241
#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
1242
 * that have to skip over a lot of full or unallowed zones.
1243 1244 1245
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1246
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274
 *
 * 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;

	if (jiffies - zlc->last_full_zap > 1 * HZ) {
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1275
					&node_states[N_HIGH_MEMORY];
1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355
	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.
 */
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zone **z,
						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;

	i = z - zonelist->zones;
	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.
 */
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **z)
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

	i = z - zonelist->zones;

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

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

static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zone **z,
				nodemask_t *allowednodes)
{
	return 1;
}

static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **z)
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1356
/*
1357
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1358 1359 1360 1361 1362
 * a page.
 */
static struct page *
get_page_from_freelist(gfp_t gfp_mask, unsigned int order,
		struct zonelist *zonelist, int alloc_flags)
M
Martin Hicks 已提交
1363
{
1364
	struct zone **z;
R
Rohit Seth 已提交
1365
	struct page *page = NULL;
1366
	int classzone_idx = zone_idx(zonelist->zones[0]);
1367
	struct zone *zone;
1368 1369 1370
	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 */
1371
	enum zone_type highest_zoneidx = -1; /* Gets set for policy zonelists */
R
Rohit Seth 已提交
1372

1373
zonelist_scan:
R
Rohit Seth 已提交
1374
	/*
1375
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1376 1377
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1378 1379
	z = zonelist->zones;

R
Rohit Seth 已提交
1380
	do {
1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392
		/*
		 * In NUMA, this could be a policy zonelist which contains
		 * zones that may not be allowed by the current gfp_mask.
		 * Check the zone is allowed by the current flags
		 */
		if (unlikely(alloc_should_filter_zonelist(zonelist))) {
			if (highest_zoneidx == -1)
				highest_zoneidx = gfp_zone(gfp_mask);
			if (zone_idx(*z) > highest_zoneidx)
				continue;
		}

1393 1394 1395
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
1396
		zone = *z;
R
Rohit Seth 已提交
1397
		if ((alloc_flags & ALLOC_CPUSET) &&
1398
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1399
				goto try_next_zone;
R
Rohit Seth 已提交
1400 1401

		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1402 1403
			unsigned long mark;
			if (alloc_flags & ALLOC_WMARK_MIN)
1404
				mark = zone->pages_min;
1405
			else if (alloc_flags & ALLOC_WMARK_LOW)
1406
				mark = zone->pages_low;
1407
			else
1408
				mark = zone->pages_high;
1409 1410
			if (!zone_watermark_ok(zone, order, mark,
				    classzone_idx, alloc_flags)) {
1411
				if (!zone_reclaim_mode ||
1412
				    !zone_reclaim(zone, gfp_mask, order))
1413
					goto this_zone_full;
1414
			}
R
Rohit Seth 已提交
1415 1416
		}

1417
		page = buffered_rmqueue(zonelist, zone, order, gfp_mask);
1418
		if (page)
R
Rohit Seth 已提交
1419
			break;
1420 1421 1422 1423 1424 1425 1426 1427 1428 1429
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;
		}
R
Rohit Seth 已提交
1430
	} while (*(++z) != NULL);
1431 1432 1433 1434 1435 1436

	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
1437
	return page;
M
Martin Hicks 已提交
1438 1439
}

L
Linus Torvalds 已提交
1440 1441 1442 1443
/*
 * This is the 'heart' of the zoned buddy allocator.
 */
struct page * fastcall
A
Al Viro 已提交
1444
__alloc_pages(gfp_t gfp_mask, unsigned int order,
L
Linus Torvalds 已提交
1445 1446
		struct zonelist *zonelist)
{
A
Al Viro 已提交
1447
	const gfp_t wait = gfp_mask & __GFP_WAIT;
R
Rohit Seth 已提交
1448
	struct zone **z;
L
Linus Torvalds 已提交
1449 1450 1451 1452
	struct page *page;
	struct reclaim_state reclaim_state;
	struct task_struct *p = current;
	int do_retry;
R
Rohit Seth 已提交
1453
	int alloc_flags;
L
Linus Torvalds 已提交
1454 1455 1456 1457
	int did_some_progress;

	might_sleep_if(wait);

1458 1459 1460
	if (should_fail_alloc_page(gfp_mask, order))
		return NULL;

1461
restart:
R
Rohit Seth 已提交
1462
	z = zonelist->zones;  /* the list of zones suitable for gfp_mask */
L
Linus Torvalds 已提交
1463

R
Rohit Seth 已提交
1464
	if (unlikely(*z == NULL)) {
1465 1466 1467 1468
		/*
		 * 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
1469 1470
		return NULL;
	}
1471

R
Rohit Seth 已提交
1472
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
1473
				zonelist, ALLOC_WMARK_LOW|ALLOC_CPUSET);
R
Rohit Seth 已提交
1474 1475
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1476

1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487
	/*
	 * 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;

1488
	for (z = zonelist->zones; *z; z++)
1489
		wakeup_kswapd(*z, order);
L
Linus Torvalds 已提交
1490

1491
	/*
R
Rohit Seth 已提交
1492 1493 1494 1495 1496 1497
	 * 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
1498 1499
	 * policy or is asking for __GFP_HIGH memory.  GFP_ATOMIC requests will
	 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1500
	 */
1501
	alloc_flags = ALLOC_WMARK_MIN;
R
Rohit Seth 已提交
1502 1503 1504 1505
	if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)
		alloc_flags |= ALLOC_HARDER;
	if (gfp_mask & __GFP_HIGH)
		alloc_flags |= ALLOC_HIGH;
1506 1507
	if (wait)
		alloc_flags |= ALLOC_CPUSET;
L
Linus Torvalds 已提交
1508 1509 1510

	/*
	 * Go through the zonelist again. Let __GFP_HIGH and allocations
R
Rohit Seth 已提交
1511
	 * coming from realtime tasks go deeper into reserves.
L
Linus Torvalds 已提交
1512 1513 1514
	 *
	 * This is the last chance, in general, before the goto nopage.
	 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1515
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
L
Linus Torvalds 已提交
1516
	 */
R
Rohit Seth 已提交
1517 1518 1519
	page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags);
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1520 1521

	/* This allocation should allow future memory freeing. */
1522

1523
rebalance:
1524 1525 1526
	if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
			&& !in_interrupt()) {
		if (!(gfp_mask & __GFP_NOMEMALLOC)) {
K
Kirill Korotaev 已提交
1527
nofail_alloc:
1528
			/* go through the zonelist yet again, ignoring mins */
R
Rohit Seth 已提交
1529
			page = get_page_from_freelist(gfp_mask, order,
1530
				zonelist, ALLOC_NO_WATERMARKS);
R
Rohit Seth 已提交
1531 1532
			if (page)
				goto got_pg;
K
Kirill Korotaev 已提交
1533
			if (gfp_mask & __GFP_NOFAIL) {
1534
				congestion_wait(WRITE, HZ/50);
K
Kirill Korotaev 已提交
1535 1536
				goto nofail_alloc;
			}
L
Linus Torvalds 已提交
1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547
		}
		goto nopage;
	}

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

	cond_resched();

	/* We now go into synchronous reclaim */
1548
	cpuset_memory_pressure_bump();
L
Linus Torvalds 已提交
1549 1550 1551 1552
	p->flags |= PF_MEMALLOC;
	reclaim_state.reclaimed_slab = 0;
	p->reclaim_state = &reclaim_state;

A
Andy Whitcroft 已提交
1553
	did_some_progress = try_to_free_pages(zonelist->zones, order, gfp_mask);
L
Linus Torvalds 已提交
1554 1555 1556 1557 1558 1559

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

	cond_resched();

1560 1561 1562
	if (order != 0)
		drain_all_local_pages();

L
Linus Torvalds 已提交
1563
	if (likely(did_some_progress)) {
R
Rohit Seth 已提交
1564 1565 1566 1567
		page = get_page_from_freelist(gfp_mask, order,
						zonelist, alloc_flags);
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
1568
	} else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1569 1570 1571 1572 1573
		if (!try_set_zone_oom(zonelist)) {
			schedule_timeout_uninterruptible(1);
			goto restart;
		}

L
Linus Torvalds 已提交
1574 1575 1576 1577 1578 1579
		/*
		 * 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.
		 */
R
Rohit Seth 已提交
1580
		page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
1581
				zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET);
1582 1583
		if (page) {
			clear_zonelist_oom(zonelist);
R
Rohit Seth 已提交
1584
			goto got_pg;
1585
		}
L
Linus Torvalds 已提交
1586

1587
		/* The OOM killer will not help higher order allocs so fail */
1588 1589
		if (order > PAGE_ALLOC_COSTLY_ORDER) {
			clear_zonelist_oom(zonelist);
1590
			goto nopage;
1591
		}
1592

1593
		out_of_memory(zonelist, gfp_mask, order);
1594
		clear_zonelist_oom(zonelist);
L
Linus Torvalds 已提交
1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606
		goto restart;
	}

	/*
	 * Don't let big-order allocations loop unless the caller explicitly
	 * requests that.  Wait for some write requests to complete then retry.
	 *
	 * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order
	 * <= 3, but that may not be true in other implementations.
	 */
	do_retry = 0;
	if (!(gfp_mask & __GFP_NORETRY)) {
A
Andy Whitcroft 已提交
1607 1608
		if ((order <= PAGE_ALLOC_COSTLY_ORDER) ||
						(gfp_mask & __GFP_REPEAT))
L
Linus Torvalds 已提交
1609 1610 1611 1612 1613
			do_retry = 1;
		if (gfp_mask & __GFP_NOFAIL)
			do_retry = 1;
	}
	if (do_retry) {
1614
		congestion_wait(WRITE, HZ/50);
L
Linus Torvalds 已提交
1615 1616 1617 1618 1619 1620 1621 1622 1623
		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
1624
		show_mem();
L
Linus Torvalds 已提交
1625 1626 1627 1628 1629 1630 1631 1632 1633 1634
	}
got_pg:
	return page;
}

EXPORT_SYMBOL(__alloc_pages);

/*
 * Common helper functions.
 */
A
Al Viro 已提交
1635
fastcall unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
1636 1637 1638 1639 1640 1641 1642 1643 1644 1645
{
	struct page * page;
	page = alloc_pages(gfp_mask, order);
	if (!page)
		return 0;
	return (unsigned long) page_address(page);
}

EXPORT_SYMBOL(__get_free_pages);

A
Al Viro 已提交
1646
fastcall unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
1647 1648 1649 1650 1651 1652 1653
{
	struct page * page;

	/*
	 * get_zeroed_page() returns a 32-bit address, which cannot represent
	 * a highmem page
	 */
N
Nick Piggin 已提交
1654
	VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
L
Linus Torvalds 已提交
1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673

	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);
}

fastcall void __free_pages(struct page *page, unsigned int order)
{
N
Nick Piggin 已提交
1674
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686
		if (order == 0)
			free_hot_page(page);
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

fastcall void free_pages(unsigned long addr, unsigned int order)
{
	if (addr != 0) {
N
Nick Piggin 已提交
1687
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
1688 1689 1690 1691 1692 1693 1694 1695
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

static unsigned int nr_free_zone_pages(int offset)
{
1696 1697
	/* Just pick one node, since fallback list is circular */
	pg_data_t *pgdat = NODE_DATA(numa_node_id());
L
Linus Torvalds 已提交
1698 1699
	unsigned int sum = 0;

1700 1701 1702
	struct zonelist *zonelist = pgdat->node_zonelists + offset;
	struct zone **zonep = zonelist->zones;
	struct zone *zone;
L
Linus Torvalds 已提交
1703

1704 1705 1706 1707 1708
	for (zone = *zonep++; zone; zone = *zonep++) {
		unsigned long size = zone->present_pages;
		unsigned long high = zone->pages_high;
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
1709 1710 1711 1712 1713 1714 1715 1716 1717 1718
	}

	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
1719
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
1720
}
1721
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
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1722 1723 1724 1725 1726 1727

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
1728
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
1729
}
1730 1731

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
1732
{
1733
	if (NUMA_BUILD)
1734
		printk("Node %d ", zone_to_nid(zone));
L
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1735 1736 1737 1738 1739 1740
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
1741
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755
	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;
1756
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
1757
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
1758
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
1759 1760
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
1761 1762 1763 1764
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
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	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)
{
1778
	int cpu;
L
Linus Torvalds 已提交
1779 1780 1781
	struct zone *zone;

	for_each_zone(zone) {
1782
		if (!populated_zone(zone))
L
Linus Torvalds 已提交
1783
			continue;
1784 1785 1786

		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
1787

1788
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
1789 1790
			struct per_cpu_pageset *pageset;

1791
			pageset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
1792

1793 1794 1795 1796 1797 1798
			printk("CPU %4d: Hot: hi:%5d, btch:%4d usd:%4d   "
			       "Cold: hi:%5d, btch:%4d usd:%4d\n",
			       cpu, pageset->pcp[0].high,
			       pageset->pcp[0].batch, pageset->pcp[0].count,
			       pageset->pcp[1].high, pageset->pcp[1].batch,
			       pageset->pcp[1].count);
L
Linus Torvalds 已提交
1799 1800 1801
		}
	}

1802
	printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu\n"
1803
		" free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
1804 1805
		global_page_state(NR_ACTIVE),
		global_page_state(NR_INACTIVE),
1806
		global_page_state(NR_FILE_DIRTY),
1807
		global_page_state(NR_WRITEBACK),
1808
		global_page_state(NR_UNSTABLE_NFS),
1809
		global_page_state(NR_FREE_PAGES),
1810 1811
		global_page_state(NR_SLAB_RECLAIMABLE) +
			global_page_state(NR_SLAB_UNRECLAIMABLE),
1812
		global_page_state(NR_FILE_MAPPED),
1813 1814
		global_page_state(NR_PAGETABLE),
		global_page_state(NR_BOUNCE));
L
Linus Torvalds 已提交
1815 1816 1817 1818

	for_each_zone(zone) {
		int i;

1819 1820 1821
		if (!populated_zone(zone))
			continue;

L
Linus Torvalds 已提交
1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834
		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,
1835
			K(zone_page_state(zone, NR_FREE_PAGES)),
L
Linus Torvalds 已提交
1836 1837 1838
			K(zone->pages_min),
			K(zone->pages_low),
			K(zone->pages_high),
1839 1840
			K(zone_page_state(zone, NR_ACTIVE)),
			K(zone_page_state(zone, NR_INACTIVE)),
L
Linus Torvalds 已提交
1841 1842
			K(zone->present_pages),
			zone->pages_scanned,
1843
			(zone_is_all_unreclaimable(zone) ? "yes" : "no")
L
Linus Torvalds 已提交
1844 1845 1846 1847 1848 1849 1850 1851
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

	for_each_zone(zone) {
1852
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
L
Linus Torvalds 已提交
1853

1854 1855 1856
		if (!populated_zone(zone))
			continue;

L
Linus Torvalds 已提交
1857 1858 1859 1860 1861
		show_node(zone);
		printk("%s: ", zone->name);

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
1862 1863
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
L
Linus Torvalds 已提交
1864 1865
		}
		spin_unlock_irqrestore(&zone->lock, flags);
1866 1867
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
L
Linus Torvalds 已提交
1868 1869 1870 1871 1872 1873 1874 1875
		printk("= %lukB\n", K(total));
	}

	show_swap_cache_info();
}

/*
 * Builds allocation fallback zone lists.
1876 1877
 *
 * Add all populated zones of a node to the zonelist.
L
Linus Torvalds 已提交
1878
 */
1879 1880
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
1881
{
1882 1883
	struct zone *zone;

1884
	BUG_ON(zone_type >= MAX_NR_ZONES);
1885
	zone_type++;
1886 1887

	do {
1888
		zone_type--;
1889
		zone = pgdat->node_zones + zone_type;
1890
		if (populated_zone(zone)) {
1891 1892
			zonelist->zones[nr_zones++] = zone;
			check_highest_zone(zone_type);
L
Linus Torvalds 已提交
1893
		}
1894

1895
	} while (zone_type);
1896
	return nr_zones;
L
Linus Torvalds 已提交
1897 1898
}

1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919

/*
 *  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
1920
#ifdef CONFIG_NUMA
1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 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
/* 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
1992
#define MAX_NODE_LOAD (num_online_nodes())
1993 1994
static int node_load[MAX_NUMNODES];

L
Linus Torvalds 已提交
1995
/**
1996
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
Linus Torvalds 已提交
1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
 * @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.
 */
2009
static int find_next_best_node(int node, nodemask_t *used_node_mask)
L
Linus Torvalds 已提交
2010
{
2011
	int n, val;
L
Linus Torvalds 已提交
2012 2013 2014
	int min_val = INT_MAX;
	int best_node = -1;

2015 2016 2017 2018 2019
	/* 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
2020

2021
	for_each_node_state(n, N_HIGH_MEMORY) {
2022
		cpumask_t tmp;
L
Linus Torvalds 已提交
2023 2024 2025 2026 2027 2028 2029 2030

		/* 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);

2031 2032 2033
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
Linus Torvalds 已提交
2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054
		/* Give preference to headless and unused nodes */
		tmp = node_to_cpumask(n);
		if (!cpus_empty(tmp))
			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;
}

2055 2056 2057 2058 2059 2060 2061

/*
 * 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
2062
{
2063
	enum zone_type i;
2064
	int j;
L
Linus Torvalds 已提交
2065
	struct zonelist *zonelist;
2066 2067 2068 2069 2070 2071 2072 2073 2074 2075

	for (i = 0; i < MAX_NR_ZONES; i++) {
		zonelist = pgdat->node_zonelists + i;
		for (j = 0; zonelist->zones[j] != NULL; j++)
			;
 		j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
		zonelist->zones[j] = NULL;
	}
}

2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	enum zone_type i;
	int j;
	struct zonelist *zonelist;

	for (i = 0; i < MAX_NR_ZONES; i++) {
		zonelist = pgdat->node_zonelists + MAX_NR_ZONES + i;
		j = build_zonelists_node(pgdat, zonelist, 0, i);
		zonelist->zones[j] = NULL;
	}
}

2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157
/*
 * 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)
{
	enum zone_type i;
	int pos, j, node;
	int zone_type;		/* needs to be signed */
	struct zone *z;
	struct zonelist *zonelist;

	for (i = 0; i < MAX_NR_ZONES; i++) {
		zonelist = pgdat->node_zonelists + i;
		pos = 0;
		for (zone_type = i; 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)) {
					zonelist->zones[pos++] = z;
					check_highest_zone(zone_type);
				}
			}
		}
		zonelist->zones[pos] = NULL;
	}
}

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.
         */
2158 2159
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190
	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
2191
	nodemask_t used_mask;
2192 2193 2194
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
L
Linus Torvalds 已提交
2195 2196

	/* initialize zonelists */
2197
	for (i = 0; i < MAX_ZONELISTS; i++) {
L
Linus Torvalds 已提交
2198 2199 2200 2201 2202 2203 2204 2205 2206
		zonelist = pgdat->node_zonelists + i;
		zonelist->zones[0] = NULL;
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
	load = num_online_nodes();
	prev_node = local_node;
	nodes_clear(used_mask);
2207 2208 2209 2210 2211

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

L
Linus Torvalds 已提交
2212
	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2213 2214 2215 2216 2217 2218 2219 2220 2221
		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
2222 2223 2224 2225 2226
		/*
		 * 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.
		 */
2227
		if (distance != node_distance(local_node, prev_node))
2228 2229
			node_load[node] = load;

L
Linus Torvalds 已提交
2230 2231
		prev_node = node;
		load--;
2232 2233 2234 2235 2236
		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
2237

2238 2239 2240
	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
2241
	}
2242 2243

	build_thisnode_zonelists(pgdat);
L
Linus Torvalds 已提交
2244 2245
}

2246
/* Construct the zonelist performance cache - see further mmzone.h */
2247
static void build_zonelist_cache(pg_data_t *pgdat)
2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263
{
	int i;

	for (i = 0; i < MAX_NR_ZONES; i++) {
		struct zonelist *zonelist;
		struct zonelist_cache *zlc;
		struct zone **z;

		zonelist = pgdat->node_zonelists + i;
		zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		for (z = zonelist->zones; *z; z++)
			zlc->z_to_n[z - zonelist->zones] = zone_to_nid(*z);
	}
}

2264

L
Linus Torvalds 已提交
2265 2266
#else	/* CONFIG_NUMA */

2267 2268 2269 2270 2271 2272
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
2273
{
2274 2275
	int node, local_node;
	enum zone_type i,j;
L
Linus Torvalds 已提交
2276 2277

	local_node = pgdat->node_id;
2278
	for (i = 0; i < MAX_NR_ZONES; i++) {
L
Linus Torvalds 已提交
2279 2280 2281 2282
		struct zonelist *zonelist;

		zonelist = pgdat->node_zonelists + i;

2283
 		j = build_zonelists_node(pgdat, zonelist, 0, i);
L
Linus Torvalds 已提交
2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294
 		/*
 		 * 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;
2295
			j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
L
Linus Torvalds 已提交
2296 2297 2298 2299
		}
		for (node = 0; node < local_node; node++) {
			if (!node_online(node))
				continue;
2300
			j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
L
Linus Torvalds 已提交
2301 2302 2303 2304 2305 2306
		}

		zonelist->zones[j] = NULL;
	}
}

2307
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2308
static void build_zonelist_cache(pg_data_t *pgdat)
2309 2310 2311 2312 2313 2314 2315
{
	int i;

	for (i = 0; i < MAX_NR_ZONES; i++)
		pgdat->node_zonelists[i].zlcache_ptr = NULL;
}

L
Linus Torvalds 已提交
2316 2317
#endif	/* CONFIG_NUMA */

2318
/* return values int ....just for stop_machine_run() */
2319
static int __build_all_zonelists(void *dummy)
L
Linus Torvalds 已提交
2320
{
2321
	int nid;
2322 2323

	for_each_online_node(nid) {
2324 2325 2326 2327
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
2328
	}
2329 2330 2331
	return 0;
}

2332
void build_all_zonelists(void)
2333
{
2334 2335
	set_zonelist_order();

2336
	if (system_state == SYSTEM_BOOTING) {
2337
		__build_all_zonelists(NULL);
2338 2339
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
2340
		/* we have to stop all cpus to guarantee there is no user
2341 2342 2343 2344
		   of zonelist */
		stop_machine_run(__build_all_zonelists, NULL, NR_CPUS);
		/* cpuset refresh routine should be here */
	}
2345
	vm_total_pages = nr_free_pagecache_pages();
2346 2347 2348 2349 2350 2351 2352
	/*
	 * 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
	 */
2353
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2354 2355 2356 2357 2358 2359
		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",
2360 2361
			num_online_nodes(),
			zonelist_order_name[current_zonelist_order],
2362
			page_group_by_mobility_disabled ? "off" : "on",
2363 2364 2365 2366
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
L
Linus Torvalds 已提交
2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381
}

/*
 * 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

2382
#ifndef CONFIG_MEMORY_HOTPLUG
2383
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400
{
	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);
}
2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423
#else
/*
 * A zone's size might be changed by hot-add, so it is not possible to determine
 * a suitable size for its wait_table.  So we use the maximum size now.
 *
 * The max wait table size = 4096 x sizeof(wait_queue_head_t).   ie:
 *
 *    i386 (preemption config)    : 4096 x 16 = 64Kbyte.
 *    ia64, x86-64 (no preemption): 4096 x 20 = 80Kbyte.
 *    ia64, x86-64 (preemption)   : 4096 x 24 = 96Kbyte.
 *
 * The maximum entries are prepared when a zone's memory is (512K + 256) pages
 * or more by the traditional way. (See above).  It equals:
 *
 *    i386, x86-64, powerpc(4K page size) : =  ( 2G + 1M)byte.
 *    ia64(16K page size)                 : =  ( 8G + 4M)byte.
 *    powerpc (64K page size)             : =  (32G +16M)byte.
 */
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
{
	return 4096UL;
}
#endif
L
Linus Torvalds 已提交
2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436

/*
 * 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))

2437
/*
2438
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452
 * 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;
2453 2454
	reserve = roundup(zone->pages_min, pageblock_nr_pages) >>
							pageblock_order;
2455

2456
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490
		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
2491

L
Linus Torvalds 已提交
2492 2493 2494 2495 2496
/*
 * 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.
 */
2497
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
2498
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
2499 2500
{
	struct page *page;
A
Andy Whitcroft 已提交
2501 2502
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
L
Linus Torvalds 已提交
2503

2504
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515
		/*
		 * 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
2516 2517
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
2518
		init_page_count(page);
L
Linus Torvalds 已提交
2519 2520
		reset_page_mapcount(page);
		SetPageReserved(page);
2521 2522 2523 2524 2525 2526

		/*
		 * 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
2527 2528 2529
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
2530
		 */
2531
		if ((pfn & (pageblock_nr_pages-1)))
2532
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2533

L
Linus Torvalds 已提交
2534 2535 2536 2537
		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))
2538
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
2539 2540 2541 2542
#endif
	}
}

P
Paul Mundt 已提交
2543 2544
static void __meminit zone_init_free_lists(struct pglist_data *pgdat,
				struct zone *zone, unsigned long size)
L
Linus Torvalds 已提交
2545
{
2546 2547 2548
	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
2549 2550 2551 2552 2553 2554
		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
2555
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
2556 2557
#endif

2558
static int __devinit zone_batchsize(struct zone *zone)
2559 2560 2561 2562 2563
{
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
2564
	 * size of the zone.  But no more than 1/2 of a meg.
2565 2566 2567 2568
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
2569 2570
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
2571 2572 2573 2574 2575
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
2576 2577 2578
	 * 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.
2579
	 *
2580 2581 2582 2583
	 * 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.
2584
	 */
2585
	batch = (1 << (fls(batch + batch/2)-1)) - 1;
2586

2587 2588 2589
	return batch;
}

2590 2591 2592 2593
inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
{
	struct per_cpu_pages *pcp;

2594 2595
	memset(p, 0, sizeof(*p));

2596 2597 2598 2599 2600 2601 2602 2603 2604
	pcp = &p->pcp[0];		/* hot */
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
	INIT_LIST_HEAD(&pcp->list);

	pcp = &p->pcp[1];		/* cold*/
	pcp->count = 0;
	pcp->high = 2 * batch;
2605
	pcp->batch = max(1UL, batch/2);
2606 2607 2608
	INIT_LIST_HEAD(&pcp->list);
}

2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626
/*
 * 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;

	pcp = &p->pcp[0]; /* hot list */
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}


2627 2628
#ifdef CONFIG_NUMA
/*
2629 2630 2631 2632 2633 2634 2635
 * 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.
2636 2637 2638 2639 2640 2641 2642 2643
 *
 * 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.
2644
 */
2645
static struct per_cpu_pageset boot_pageset[NR_CPUS];
2646 2647 2648

/*
 * Dynamically allocate memory for the
2649 2650
 * per cpu pageset array in struct zone.
 */
2651
static int __cpuinit process_zones(int cpu)
2652 2653
{
	struct zone *zone, *dzone;
2654 2655 2656
	int node = cpu_to_node(cpu);

	node_set_state(node, N_CPU);	/* this node has a cpu */
2657 2658 2659

	for_each_zone(zone) {

2660 2661 2662
		if (!populated_zone(zone))
			continue;

N
Nick Piggin 已提交
2663
		zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
2664
					 GFP_KERNEL, node);
N
Nick Piggin 已提交
2665
		if (!zone_pcp(zone, cpu))
2666 2667
			goto bad;

N
Nick Piggin 已提交
2668
		setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
2669 2670 2671 2672

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(zone_pcp(zone, cpu),
			 	(zone->present_pages / percpu_pagelist_fraction));
2673 2674 2675 2676 2677
	}

	return 0;
bad:
	for_each_zone(dzone) {
2678 2679
		if (!populated_zone(dzone))
			continue;
2680 2681
		if (dzone == zone)
			break;
N
Nick Piggin 已提交
2682 2683
		kfree(zone_pcp(dzone, cpu));
		zone_pcp(dzone, cpu) = NULL;
2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694
	}
	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);

2695 2696 2697
		/* Free per_cpu_pageset if it is slab allocated */
		if (pset != &boot_pageset[cpu])
			kfree(pset);
2698 2699 2700 2701
		zone_pcp(zone, cpu) = NULL;
	}
}

2702
static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
2703 2704 2705 2706 2707 2708 2709
		unsigned long action,
		void *hcpu)
{
	int cpu = (long)hcpu;
	int ret = NOTIFY_OK;

	switch (action) {
2710
	case CPU_UP_PREPARE:
2711
	case CPU_UP_PREPARE_FROZEN:
2712 2713 2714 2715
		if (process_zones(cpu))
			ret = NOTIFY_BAD;
		break;
	case CPU_UP_CANCELED:
2716
	case CPU_UP_CANCELED_FROZEN:
2717
	case CPU_DEAD:
2718
	case CPU_DEAD_FROZEN:
2719 2720 2721 2722
		free_zone_pagesets(cpu);
		break;
	default:
		break;
2723 2724 2725 2726
	}
	return ret;
}

2727
static struct notifier_block __cpuinitdata pageset_notifier =
2728 2729
	{ &pageset_cpuup_callback, NULL, 0 };

2730
void __init setup_per_cpu_pageset(void)
2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744
{
	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
2745
static noinline __init_refok
2746
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
2747 2748 2749
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
2750
	size_t alloc_size;
2751 2752 2753 2754 2755

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
2756 2757 2758 2759
	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);
2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

 	if (system_state == SYSTEM_BOOTING) {
		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.
		 */
2777
		zone->wait_table = vmalloc(alloc_size);
2778 2779 2780
	}
	if (!zone->wait_table)
		return -ENOMEM;
2781

2782
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
2783
		init_waitqueue_head(zone->wait_table + i);
2784 2785

	return 0;
2786 2787
}

2788
static __meminit void zone_pcp_init(struct zone *zone)
2789 2790 2791 2792 2793 2794 2795
{
	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
2796
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
2797 2798 2799 2800 2801
		setup_pageset(&boot_pageset[cpu],0);
#else
		setup_pageset(zone_pcp(zone,cpu), batch);
#endif
	}
A
Anton Blanchard 已提交
2802 2803 2804
	if (zone->present_pages)
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%lu\n",
			zone->name, zone->present_pages, batch);
2805 2806
}

2807 2808
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
2809 2810
					unsigned long size,
					enum memmap_context context)
2811 2812
{
	struct pglist_data *pgdat = zone->zone_pgdat;
2813 2814 2815 2816
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
2817 2818 2819 2820 2821 2822 2823
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

	memmap_init(size, pgdat->node_id, zone_idx(zone), zone_start_pfn);

	zone_init_free_lists(pgdat, zone, zone->spanned_pages);
2824 2825

	return 0;
2826 2827
}

2828 2829 2830 2831 2832
#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
 */
2833
static int __meminit first_active_region_index_in_nid(int nid)
2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845
{
	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
2846
 * Note: nid == MAX_NUMNODES returns next region regardless of node
2847
 */
2848
static int __meminit next_active_region_index_in_nid(int index, int nid)
2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863
{
	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
 */
2864
int __meminit early_pfn_to_nid(unsigned long pfn)
2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886
{
	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
2887 2888
 * @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
2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917
 *
 * 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);
	}
}

/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
2918
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
2919 2920 2921
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
2922
 * function may be used instead of calling memory_present() manually.
2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933
 */
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);
}

2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964
/**
 * 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)
{
	printk(KERN_DEBUG "Entering push_node_boundaries(%u, %lu, %lu)\n",
			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 */
2965
static void __meminit account_node_boundary(unsigned int nid,
2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984
		unsigned long *start_pfn, unsigned long *end_pfn)
{
	printk(KERN_DEBUG "Entering account_node_boundary(%u, %lu, %lu)\n",
			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) {}

2985
static void __meminit account_node_boundary(unsigned int nid,
2986 2987 2988 2989
		unsigned long *start_pfn, unsigned long *end_pfn) {}
#endif


2990 2991
/**
 * get_pfn_range_for_nid - Return the start and end page frames for a node
2992 2993 2994
 * @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.
2995 2996 2997 2998
 *
 * 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
2999
 * PFNs will be 0.
3000
 */
3001
void __meminit get_pfn_range_for_nid(unsigned int nid,
3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012
			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);
	}

3013
	if (*start_pfn == -1UL)
3014
		*start_pfn = 0;
3015 3016 3017

	/* Push the node boundaries out if requested */
	account_node_boundary(nid, start_pfn, end_pfn);
3018 3019
}

M
Mel Gorman 已提交
3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076
/*
 * 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;
	}
}

3077 3078 3079 3080
/*
 * 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
3081
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3082 3083 3084 3085 3086 3087 3088 3089 3090 3091
					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
3092 3093 3094
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109

	/* 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,
3110
 * then all holes in the requested range will be accounted for.
3111
 */
3112
unsigned long __meminit __absent_pages_in_range(int nid,
3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124
				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;

3125 3126
	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);

3127 3128
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
3129
		hole_pages = prev_end_pfn - range_start_pfn;
3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149

	/* 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;
	}

3150 3151
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
3152
		hole_pages += range_end_pfn -
3153 3154
				max(range_start_pfn, prev_end_pfn);

3155 3156 3157 3158 3159 3160 3161 3162
	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
 *
3163
 * It returns the number of pages frames in memory holes within a range.
3164 3165 3166 3167 3168 3169 3170 3171
 */
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
3172
static unsigned long __meminit zone_absent_pages_in_node(int nid,
3173 3174 3175
					unsigned long zone_type,
					unsigned long *ignored)
{
3176 3177 3178 3179 3180 3181 3182 3183 3184
	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
3185 3186 3187
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
3188
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3189
}
3190

3191
#else
P
Paul Mundt 已提交
3192
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3193 3194 3195 3196 3197 3198
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
3199
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3200 3201 3202 3203 3204 3205 3206 3207
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
3208

3209 3210
#endif

3211
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231
		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);
}

3232 3233 3234
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
3235 3236
 * 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
3237 3238 3239 3240 3241 3242 3243
 * 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;

3244 3245
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266
	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 */

3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
/* 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 */

/* Defined this way to avoid accidently referencing HUGETLB_PAGE_ORDER */
#define set_pageblock_order(x)	do {} while (0)

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
3288 3289 3290 3291 3292 3293
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
3294
static void __meminit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3295 3296
		unsigned long *zones_size, unsigned long *zholes_size)
{
3297
	enum zone_type j;
3298
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
3299
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
3300
	int ret;
L
Linus Torvalds 已提交
3301

3302
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
3303 3304 3305 3306 3307 3308
	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;
3309
		unsigned long size, realsize, memmap_pages;
L
Linus Torvalds 已提交
3310

3311 3312 3313
		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
3314

3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330
		/*
		 * 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
		 */
		memmap_pages = (size * sizeof(struct page)) >> PAGE_SHIFT;
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
			printk(KERN_DEBUG
				"  %s zone: %lu pages used for memmap\n",
				zone_names[j], memmap_pages);
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

3331 3332
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
3333
			realsize -= dma_reserve;
3334 3335
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
					zone_names[0], dma_reserve);
3336 3337
		}

3338
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
3339 3340 3341 3342 3343
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
3344
#ifdef CONFIG_NUMA
3345
		zone->node = nid;
3346
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3347
						/ 100;
3348
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3349
#endif
L
Linus Torvalds 已提交
3350 3351 3352
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
3353
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
3354 3355
		zone->zone_pgdat = pgdat;

3356
		zone->prev_priority = DEF_PRIORITY;
L
Linus Torvalds 已提交
3357

3358
		zone_pcp_init(zone);
L
Linus Torvalds 已提交
3359 3360 3361 3362
		INIT_LIST_HEAD(&zone->active_list);
		INIT_LIST_HEAD(&zone->inactive_list);
		zone->nr_scan_active = 0;
		zone->nr_scan_inactive = 0;
3363
		zap_zone_vm_stats(zone);
3364
		zone->flags = 0;
L
Linus Torvalds 已提交
3365 3366 3367
		if (!size)
			continue;

3368
		set_pageblock_order(HUGETLB_PAGE_ORDER);
3369
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
3370 3371
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
3372
		BUG_ON(ret);
L
Linus Torvalds 已提交
3373 3374 3375 3376
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
3377
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
3378 3379 3380 3381 3382
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
3383
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
3384 3385
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
3386
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
3387 3388
		struct page *map;

3389 3390 3391 3392 3393 3394 3395 3396 3397
		/*
		 * 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);
3398 3399 3400
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
3401
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
3402
	}
3403
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
3404 3405 3406
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
3407
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
3408
		mem_map = NODE_DATA(0)->node_mem_map;
3409 3410 3411 3412 3413
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
			mem_map -= pgdat->node_start_pfn;
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
3414
#endif
A
Andy Whitcroft 已提交
3415
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
3416 3417
}

3418
void __meminit free_area_init_node(int nid, struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3419 3420 3421 3422 3423
		unsigned long *zones_size, unsigned long node_start_pfn,
		unsigned long *zholes_size)
{
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
3424
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
3425 3426 3427 3428 3429 3430

	alloc_node_mem_map(pgdat);

	free_area_init_core(pgdat, zones_size, zholes_size);
}

3431
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
M
Miklos Szeredi 已提交
3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451

#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

3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537
/**
 * 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;

	printk(KERN_DEBUG "Entering add_active_range(%d, %lu, %lu) "
			  "%d entries of %d used\n",
			  nid, start_pfn, end_pfn,
			  nr_nodemap_entries, MAX_ACTIVE_REGIONS);

	/* 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;
}

/**
 * shrink_active_range - Shrink an existing registered range of PFNs
 * @nid: The node id the range is on that should be shrunk
 * @old_end_pfn: The old end PFN of the range
 * @new_end_pfn: The new PFN of the range
 *
 * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
 * The map is kept at the end physical page range that has already been
 * registered with add_active_range(). This function allows an arch to shrink
 * an existing registered range.
 */
void __init shrink_active_range(unsigned int nid, unsigned long old_end_pfn,
						unsigned long new_end_pfn)
{
	int i;

	/* Find the old active region end and shrink */
	for_each_active_range_index_in_nid(i, nid)
		if (early_node_map[i].end_pfn == old_end_pfn) {
			early_node_map[i].end_pfn = new_end_pfn;
			break;
		}
}

/**
 * remove_all_active_ranges - Remove all currently registered regions
3538
 *
3539 3540 3541 3542
 * 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.
 */
3543
void __init remove_all_active_ranges(void)
3544 3545 3546
{
	memset(early_node_map, 0, sizeof(early_node_map));
	nr_nodemap_entries = 0;
3547 3548 3549 3550
#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 */
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
}

/* 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);
}

3576
/* Find the lowest pfn for a node */
3577 3578 3579
unsigned long __init find_min_pfn_for_node(unsigned long nid)
{
	int i;
3580
	unsigned long min_pfn = ULONG_MAX;
3581

3582 3583
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
3584
		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
3585

3586 3587 3588 3589 3590 3591 3592
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
			"Could not find start_pfn for node %lu\n", nid);
		return 0;
	}

	return min_pfn;
3593 3594 3595 3596 3597 3598
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
3599
 * add_active_range().
3600 3601 3602 3603 3604 3605 3606 3607 3608 3609
 */
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
3610
 * add_active_range().
3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622
 */
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;
}

3623 3624 3625 3626 3627
/*
 * 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
3628
static unsigned long __init early_calculate_totalpages(void)
3629 3630 3631 3632
{
	int i;
	unsigned long totalpages = 0;

3633 3634
	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long pages = early_node_map[i].end_pfn -
3635
						early_node_map[i].start_pfn;
3636 3637 3638 3639 3640
		totalpages += pages;
		if (pages)
			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
	}
  	return totalpages;
3641 3642
}

M
Mel Gorman 已提交
3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653
/*
 * 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;
3654 3655
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
3656

3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678
	/*
	 * If movablecore was specified, calculate what size of
	 * kernelcore that corresponds so that memory usable for
	 * any allocation type is evenly spread. If both kernelcore
	 * and movablecore are specified, then the value of kernelcore
	 * will be used for required_kernelcore if it's greater than
	 * what movablecore would have allowed.
	 */
	if (required_movablecore) {
		unsigned long corepages;

		/*
		 * Round-up so that ZONE_MOVABLE is at least as large as what
		 * was requested by the user
		 */
		required_movablecore =
			roundup(required_movablecore, MAX_ORDER_NR_PAGES);
		corepages = totalpages - required_movablecore;

		required_kernelcore = max(required_kernelcore, corepages);
	}

M
Mel Gorman 已提交
3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689
	/* 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;
3690
	for_each_node_state(nid, N_HIGH_MEMORY) {
M
Mel Gorman 已提交
3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781
		/*
		 * 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);
}

3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795
/* 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
}

3796 3797
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
3798
 * @max_zone_pfn: an array of max PFNs for each zone
3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813
 *
 * 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;

3814 3815 3816
	/* Sort early_node_map as initialisation assumes it is sorted */
	sort_node_map();

3817 3818 3819 3820 3821 3822 3823 3824
	/* 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
3825 3826
		if (i == ZONE_MOVABLE)
			continue;
3827 3828 3829 3830 3831
		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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3832 3833 3834 3835 3836 3837
	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);
3838 3839 3840

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
M
Mel Gorman 已提交
3841 3842 3843
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
3844 3845 3846 3847
		printk("  %-8s %8lu -> %8lu\n",
				zone_names[i],
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);
M
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3848 3849 3850 3851 3852 3853 3854 3855
	}

	/* 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]);
	}
3856 3857 3858 3859 3860 3861 3862 3863 3864

	/* 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++)
		printk("  %3d: %8lu -> %8lu\n", early_node_map[i].nid,
						early_node_map[i].start_pfn,
						early_node_map[i].end_pfn);

	/* Initialise every node */
3865
	setup_nr_node_ids();
3866 3867 3868 3869
	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);
3870 3871 3872 3873 3874

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
3875 3876
	}
}
M
Mel Gorman 已提交
3877

3878
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
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3879 3880 3881 3882 3883 3884
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
3885
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
3886

3887
	/* Paranoid check that UL is enough for the coremem value */
M
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3888 3889 3890 3891
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
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3892

3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910
/*
 * kernelcore=size sets the amount of memory for use for allocations that
 * cannot be reclaimed or migrated.
 */
static int __init cmdline_parse_kernelcore(char *p)
{
	return cmdline_parse_core(p, &required_kernelcore);
}

/*
 * movablecore=size sets the amount of memory for use for allocations that
 * can be reclaimed or migrated.
 */
static int __init cmdline_parse_movablecore(char *p)
{
	return cmdline_parse_core(p, &required_movablecore);
}

M
Mel Gorman 已提交
3911
early_param("kernelcore", cmdline_parse_kernelcore);
3912
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
3913

3914 3915
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

3916
/**
3917 3918
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
3919 3920 3921 3922
 *
 * 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
3923 3924 3925
 * 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.
3926 3927 3928 3929 3930 3931
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

3932
#ifndef CONFIG_NEED_MULTIPLE_NODES
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3933 3934 3935 3936
static bootmem_data_t contig_bootmem_data;
struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data };

EXPORT_SYMBOL(contig_page_data);
3937
#endif
L
Linus Torvalds 已提交
3938 3939 3940

void __init free_area_init(unsigned long *zones_size)
{
3941
	free_area_init_node(0, NODE_DATA(0), zones_size,
L
Linus Torvalds 已提交
3942 3943 3944 3945 3946 3947 3948 3949
			__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;

3950
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
L
Linus Torvalds 已提交
3951 3952
		local_irq_disable();
		__drain_pages(cpu);
3953
		vm_events_fold_cpu(cpu);
L
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3954
		local_irq_enable();
3955
		refresh_cpu_vm_stats(cpu);
L
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3956 3957 3958 3959 3960 3961 3962 3963 3964
	}
	return NOTIFY_OK;
}

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

3965 3966 3967 3968 3969 3970 3971 3972
/*
 * 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;
3973
	enum zone_type i, j;
3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996

	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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3997 3998 3999 4000 4001 4002 4003 4004 4005
/*
 * 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;
4006
	enum zone_type j, idx;
L
Linus Torvalds 已提交
4007

4008
	for_each_online_pgdat(pgdat) {
L
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4009 4010 4011 4012 4013 4014
		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;

4015 4016
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
4017 4018
				struct zone *lower_zone;

4019 4020
				idx--;

L
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4021 4022 4023 4024 4025 4026 4027 4028 4029 4030
				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;
			}
		}
	}
4031 4032 4033

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4034 4035
}

4036 4037 4038 4039 4040
/**
 * 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
Linus Torvalds 已提交
4041
 */
4042
void setup_per_zone_pages_min(void)
L
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4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055
{
	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) {
4056 4057
		u64 tmp;

L
Linus Torvalds 已提交
4058
		spin_lock_irqsave(&zone->lru_lock, flags);
4059 4060
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
4061 4062
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
4063 4064 4065 4066 4067 4068 4069
			 * __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
Linus Torvalds 已提交
4070 4071 4072 4073 4074 4075 4076 4077 4078 4079
			 */
			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
4080 4081
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
4082 4083
			 * proportionate to the zone's size.
			 */
N
Nick Piggin 已提交
4084
			zone->pages_min = tmp;
L
Linus Torvalds 已提交
4085 4086
		}

4087 4088
		zone->pages_low   = zone->pages_min + (tmp >> 2);
		zone->pages_high  = zone->pages_min + (tmp >> 1);
4089
		setup_zone_migrate_reserve(zone);
L
Linus Torvalds 已提交
4090 4091
		spin_unlock_irqrestore(&zone->lru_lock, flags);
	}
4092 4093 4094

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
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4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137 4138 4139 4140 4141 4142 4143 4144 4145 4146
}

/*
 * 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);
4147 4148
	if (write)
		setup_per_zone_pages_min();
L
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4149 4150 4151
	return 0;
}

4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163
#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)
4164
		zone->min_unmapped_pages = (zone->present_pages *
4165 4166 4167
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178 4179 4180 4181 4182 4183

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;
}
4184 4185
#endif

L
Linus Torvalds 已提交
4186 4187 4188 4189 4190 4191 4192 4193 4194 4195 4196 4197 4198 4199 4200 4201 4202
/*
 * 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;
}

4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228
/*
 * 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;
}

4229
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
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

#ifdef CONFIG_NUMA
static int __init set_hashdist(char *str)
{
	if (!str)
		return 0;
	hashdist = simple_strtoul(str, &str, 0);
	return 1;
}
__setup("hashdist=", set_hashdist);
#endif

/*
 * allocate a large system hash table from bootmem
 * - it is assumed that the hash table must contain an exact power-of-2
 *   quantity of entries
 * - limit is the number of hash buckets, not the total allocation size
 */
void *__init alloc_large_system_hash(const char *tablename,
				     unsigned long bucketsize,
				     unsigned long numentries,
				     int scale,
				     int flags,
				     unsigned int *_hash_shift,
				     unsigned int *_hash_mask,
				     unsigned long limit)
{
	unsigned long long max = limit;
	unsigned long log2qty, size;
	void *table = NULL;

	/* allow the kernel cmdline to have a say */
	if (!numentries) {
		/* round applicable memory size up to nearest megabyte */
A
Andrew Morton 已提交
4264
		numentries = nr_kernel_pages;
L
Linus Torvalds 已提交
4265 4266 4267 4268 4269 4270 4271 4272 4273
		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);
4274 4275 4276 4277

		/* Make sure we've got at least a 0-order allocation.. */
		if (unlikely((numentries * bucketsize) < PAGE_SIZE))
			numentries = PAGE_SIZE / bucketsize;
L
Linus Torvalds 已提交
4278
	}
4279
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
4280 4281 4282 4283 4284 4285 4286 4287 4288 4289

	/* 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;

4290
	log2qty = ilog2(numentries);
L
Linus Torvalds 已提交
4291 4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
			table = alloc_bootmem(size);
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
			unsigned long order;
			for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++)
				;
			table = (void*) __get_free_pages(GFP_ATOMIC, order);
4303 4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317
			/*
			 * 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;
				}
			}
L
Linus Torvalds 已提交
4318 4319 4320 4321 4322 4323
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

4324
	printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
L
Linus Torvalds 已提交
4325 4326
	       tablename,
	       (1U << log2qty),
4327
	       ilog2(size) - PAGE_SHIFT,
L
Linus Torvalds 已提交
4328 4329 4330 4331 4332 4333 4334 4335 4336
	       size);

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

	return table;
}
4337 4338 4339 4340

#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
struct page *pfn_to_page(unsigned long pfn)
{
4341
	return __pfn_to_page(pfn);
4342 4343 4344
}
unsigned long page_to_pfn(struct page *page)
{
4345
	return __page_to_pfn(page);
4346 4347 4348 4349
}
EXPORT_SYMBOL(pfn_to_page);
EXPORT_SYMBOL(page_to_pfn);
#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
4350

4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363 4364 4365
/* 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);
4366
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4367 4368
#else
	pfn = pfn - zone->zone_start_pfn;
4369
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
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#endif /* CONFIG_SPARSEMEM */
}

/**
4374
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
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 * @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;
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	return flags;
}

/**
4402
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
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 * @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);

	for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
		if (flags & value)
			__set_bit(bitidx + start_bitidx, bitmap);
		else
			__clear_bit(bitidx + start_bitidx, bitmap);
}
K
KAMEZAWA Hiroyuki 已提交
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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)
		drain_all_local_pages();
	return ret;
}

void unset_migratetype_isolate(struct page *page)
{
	struct zone *zone;
	unsigned long flags;
	zone = page_zone(page);
	spin_lock_irqsave(&zone->lock, flags);
	if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
		goto out;
	set_pageblock_migratetype(page, MIGRATE_MOVABLE);
	move_freepages_block(zone, page, MIGRATE_MOVABLE);
out:
	spin_unlock_irqrestore(&zone->lock, flags);
}
K
KAMEZAWA Hiroyuki 已提交
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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