page_alloc.c 124.6 KB
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/*
 *  linux/mm/page_alloc.c
 *
 *  Manages the free list, the system allocates free pages here.
 *  Note that kmalloc() lives in slab.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *  Swap reorganised 29.12.95, Stephen Tweedie
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *  Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
 *  Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
 *  Zone balancing, Kanoj Sarcar, SGI, Jan 2000
 *  Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
 *          (lots of bits borrowed from Ingo Molnar & Andrew Morton)
 */

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

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

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unsigned long totalram_pages __read_mostly;
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unsigned long totalreserve_pages __read_mostly;
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long nr_swap_pages;
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int percpu_pagelist_fraction;
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#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
int pageblock_order __read_mostly;
#endif

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

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

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int min_free_kbytes = 1024;

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

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

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

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int page_group_by_mobility_disabled __read_mostly;

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static void set_pageblock_migratetype(struct page *page, int migratetype)
{
	set_pageblock_flags_group(page, (unsigned long)migratetype,
					PB_migrate, PB_migrate_end);
}

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

	return ret;
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}

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

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

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

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static void bad_page(struct page *page)
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{
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	void *pc = page_get_page_cgroup(page);

	printk(KERN_EMERG "Bad page state in process '%s'\n" KERN_EMERG
		"page:%p flags:0x%0*lx mapping:%p mapcount:%d count:%d\n",
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		current->comm, page, (int)(2*sizeof(unsigned long)),
		(unsigned long)page->flags, page->mapping,
		page_mapcount(page), page_count(page));
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	if (pc) {
		printk(KERN_EMERG "cgroup:%p\n", pc);
		page_reset_bad_cgroup(page);
	}
	printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n"
		KERN_EMERG "Backtrace:\n");
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	dump_stack();
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	page->flags &= ~(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)  |
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		(page_get_page_cgroup(page) != NULL) |
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		(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;
528
	int reserved = 0;
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	for (i = 0 ; i < (1 << order) ; ++i)
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		reserved += free_pages_check(page + i);
532 533 534
	if (reserved)
		return;

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	if (!PageHighMem(page))
		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
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	arch_free_page(page, order);
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	kernel_map_pages(page, 1 << order, 0);
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	local_irq_save(flags);
541
	__count_vm_events(PGFREE, 1 << order);
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	free_one_page(page_zone(page), page, order);
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	local_irq_restore(flags);
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}

546 547 548
/*
 * permit the bootmem allocator to evade page validation on high-order frees
 */
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void __init __free_pages_bootmem(struct page *page, unsigned int order)
550 551 552 553
{
	if (order == 0) {
		__ClearPageReserved(page);
		set_page_count(page, 0);
554
		set_page_refcounted(page);
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		__free_page(page);
556 557 558
	} else {
		int loop;

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		prefetchw(page);
560 561 562
		for (loop = 0; loop < BITS_PER_LONG; loop++) {
			struct page *p = &page[loop];

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			if (loop + 1 < BITS_PER_LONG)
				prefetchw(p + 1);
565 566 567 568
			__ClearPageReserved(p);
			set_page_count(p, 0);
		}

569
		set_page_refcounted(page);
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		__free_pages(page, order);
571 572 573
	}
}

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/*
 * 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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static inline void expand(struct zone *zone, struct page *page,
590 591
	int low, int high, struct free_area *area,
	int migratetype)
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{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
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		VM_BUG_ON(bad_range(zone, &page[size]));
600
		list_add(&page[size].lru, &area->free_list[migratetype]);
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		area->nr_free++;
		set_page_order(&page[size], high);
	}
}

/*
 * This page is about to be returned from the page allocator
 */
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static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
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{
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	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
613
		(page_get_page_cgroup(page) != NULL) |
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		(page_count(page) != 0)  |
615 616
		(page->flags & (
			1 << PG_lru	|
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			1 << PG_private	|
			1 << PG_locked	|
			1 << PG_active	|
			1 << PG_dirty	|
621
			1 << PG_slab    |
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			1 << PG_swapcache |
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			1 << PG_writeback |
624 625
			1 << PG_reserved |
			1 << PG_buddy ))))
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		bad_page(page);
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628 629 630 631 632 633 634
	/*
	 * 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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	page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_readahead |
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			1 << PG_referenced | 1 << PG_arch_1 |
637
			1 << PG_owner_priv_1 | 1 << PG_mappedtodisk);
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	set_page_private(page, 0);
639
	set_page_refcounted(page);
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	arch_alloc_page(page, order);
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	kernel_map_pages(page, 1 << order, 1);
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	if (gfp_flags & __GFP_ZERO)
		prep_zero_page(page, order, gfp_flags);

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

650
	return 0;
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}

653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683
/*
 * 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;
}


684 685 686 687 688
/*
 * 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] = {
689 690 691 692
	[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 */
693 694
};

695 696
/*
 * Move the free pages in a range to the free lists of the requested type.
697
 * Note that start_page and end_pages are not aligned on a pageblock
698 699 700 701 702 703 704 705
 * 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;
706
	int pages_moved = 0;
707 708 709 710 711 712 713

#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
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	 * grouping pages by mobility
715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734
	 */
	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;
735
		pages_moved += 1 << order;
736 737
	}

738
	return pages_moved;
739 740 741 742 743 744 745 746
}

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);
747
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
748
	start_page = pfn_to_page(start_pfn);
749 750
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
751 752 753 754 755 756 757 758 759 760

	/* 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);
}

761 762 763 764 765 766 767 768 769 770 771 772 773 774 775
/* 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];

776 777 778
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
				continue;
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780 781 782 783 784 785 786 787 788
			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--;

			/*
789
			 * If breaking a large block of pages, move all free
790 791 792
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
			 * agressive about taking ownership of free pages
793
			 */
794
			if (unlikely(current_order >= (pageblock_order >> 1)) ||
795 796 797 798 799 800
					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 */
801
				if (pages >= (1 << (pageblock_order-1)))
802 803 804
					set_pageblock_migratetype(page,
								start_migratetype);

805
				migratetype = start_migratetype;
806
			}
807 808 809 810 811 812 813

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

814
			if (current_order == pageblock_order)
815 816 817 818 819 820 821 822
				set_pageblock_migratetype(page,
							start_migratetype);

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

823 824
	/* Use MIGRATE_RESERVE rather than fail an allocation */
	return __rmqueue_smallest(zone, order, MIGRATE_RESERVE);
825 826
}

827
/*
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 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
831 832
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
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833 834 835
{
	struct page *page;

836
	page = __rmqueue_smallest(zone, order, migratetype);
837

838 839
	if (unlikely(!page))
		page = __rmqueue_fallback(zone, order, migratetype);
840 841

	return page;
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}

/* 
 * 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, 
850 851
			unsigned long count, struct list_head *list,
			int migratetype)
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{
	int i;
	
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	spin_lock(&zone->lock);
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856
	for (i = 0; i < count; ++i) {
857
		struct page *page = __rmqueue(zone, order, migratetype);
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858
		if (unlikely(page == NULL))
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			break;
860 861 862 863 864 865 866 867 868 869

		/*
		 * Split buddy pages returned by expand() are received here
		 * in physical page order. The page is added to the callers and
		 * list and the list head then moves forward. From the callers
		 * perspective, the linked list is ordered by page number in
		 * some conditions. This is useful for IO devices that can
		 * merge IO requests if the physical pages are ordered
		 * properly.
		 */
870 871
		list_add(&page->lru, list);
		set_page_private(page, migratetype);
872
		list = &page->lru;
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873
	}
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	spin_unlock(&zone->lock);
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875
	return i;
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}

878
#ifdef CONFIG_NUMA
879
/*
880 881 882 883
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
884 885
 * Note that this function must be called with the thread pinned to
 * a single processor.
886
 */
887
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
888 889
{
	unsigned long flags;
890
	int to_drain;
891

892 893 894 895 896 897 898 899
	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);
900 901 902
}
#endif

903 904 905 906 907 908 909 910
/*
 * Drain pages of the indicated processor.
 *
 * The processor must either be the current processor and the
 * thread pinned to the current processor or a processor that
 * is not online.
 */
static void drain_pages(unsigned int cpu)
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{
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912
	unsigned long flags;
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913 914 915 916
	struct zone *zone;

	for_each_zone(zone) {
		struct per_cpu_pageset *pset;
917
		struct per_cpu_pages *pcp;
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919 920 921
		if (!populated_zone(zone))
			continue;

922
		pset = zone_pcp(zone, cpu);
923 924 925 926 927 928

		pcp = &pset->pcp;
		local_irq_save(flags);
		free_pages_bulk(zone, pcp->count, &pcp->list, 0);
		pcp->count = 0;
		local_irq_restore(flags);
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	}
}

932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947
/*
 * Spill all of this CPU's per-cpu pages back into the buddy allocator.
 */
void drain_local_pages(void *arg)
{
	drain_pages(smp_processor_id());
}

/*
 * Spill all the per-cpu pages from all CPUs back into the buddy allocator
 */
void drain_all_pages(void)
{
	on_each_cpu(drain_local_pages, NULL, 0, 1);
}

948
#ifdef CONFIG_HIBERNATION
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void mark_free_pages(struct zone *zone)
{
952 953
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
954
	int order, t;
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	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
961 962 963 964 965 966

	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);

967 968
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
969
		}
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971 972
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
973
			unsigned long i;
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975 976
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
977
				swsusp_set_page_free(pfn_to_page(pfn + i));
978
		}
979
	}
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	spin_unlock_irqrestore(&zone->lock, flags);
}
982
#endif /* CONFIG_PM */
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/*
 * Free a 0-order page
 */
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static void free_hot_cold_page(struct page *page, int cold)
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{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;

	if (PageAnon(page))
		page->mapping = NULL;
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	if (free_pages_check(page))
996 997
		return;

N
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	if (!PageHighMem(page))
		debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
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	arch_free_page(page, 0);
1001 1002
	kernel_map_pages(page, 1, 0);

1003
	pcp = &zone_pcp(zone, get_cpu())->pcp;
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	local_irq_save(flags);
1005
	__count_vm_event(PGFREE);
1006 1007 1008 1009
	if (cold)
		list_add_tail(&page->lru, &pcp->list);
	else
		list_add(&page->lru, &pcp->list);
1010
	set_page_private(page, get_pageblock_migratetype(page));
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	pcp->count++;
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1012 1013 1014 1015
	if (pcp->count >= pcp->high) {
		free_pages_bulk(zone, pcp->batch, &pcp->list, 0);
		pcp->count -= pcp->batch;
	}
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	local_irq_restore(flags);
	put_cpu();
}

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void free_hot_page(struct page *page)
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1021 1022 1023 1024
{
	free_hot_cold_page(page, 0);
}
	
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void free_cold_page(struct page *page)
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{
	free_hot_cold_page(page, 1);
}

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/*
 * 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;

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Nick Piggin 已提交
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	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1044 1045
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
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1046 1047
}

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/*
 * 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.
 */
1053
static struct page *buffered_rmqueue(struct zone *preferred_zone,
N
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			struct zone *zone, int order, gfp_t gfp_flags)
L
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1055 1056
{
	unsigned long flags;
1057
	struct page *page;
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1058
	int cold = !!(gfp_flags & __GFP_COLD);
N
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1059
	int cpu;
1060
	int migratetype = allocflags_to_migratetype(gfp_flags);
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1061

1062
again:
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	cpu  = get_cpu();
N
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1064
	if (likely(order == 0)) {
L
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1065 1066
		struct per_cpu_pages *pcp;

1067
		pcp = &zone_pcp(zone, cpu)->pcp;
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		local_irq_save(flags);
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Nick Piggin 已提交
1069
		if (!pcp->count) {
1070
			pcp->count = rmqueue_bulk(zone, 0,
1071
					pcp->batch, &pcp->list, migratetype);
N
Nick Piggin 已提交
1072 1073
			if (unlikely(!pcp->count))
				goto failed;
L
Linus Torvalds 已提交
1074
		}
1075

1076
		/* Find a page of the appropriate migrate type */
1077 1078 1079 1080 1081 1082 1083 1084 1085
		if (cold) {
			list_for_each_entry_reverse(page, &pcp->list, lru)
				if (page_private(page) == migratetype)
					break;
		} else {
			list_for_each_entry(page, &pcp->list, lru)
				if (page_private(page) == migratetype)
					break;
		}
1086

1087 1088
		/* Allocate more to the pcp list if necessary */
		if (unlikely(&page->lru == &pcp->list)) {
1089 1090 1091 1092
			pcp->count += rmqueue_bulk(zone, 0,
					pcp->batch, &pcp->list, migratetype);
			page = list_entry(pcp->list.next, struct page, lru);
		}
1093 1094 1095

		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1096
	} else {
L
Linus Torvalds 已提交
1097
		spin_lock_irqsave(&zone->lock, flags);
1098
		page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1099 1100 1101
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
L
Linus Torvalds 已提交
1102 1103
	}

1104
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
1105
	zone_statistics(preferred_zone, zone);
N
Nick Piggin 已提交
1106 1107
	local_irq_restore(flags);
	put_cpu();
L
Linus Torvalds 已提交
1108

N
Nick Piggin 已提交
1109
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1110
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1111
		goto again;
L
Linus Torvalds 已提交
1112
	return page;
N
Nick Piggin 已提交
1113 1114 1115 1116 1117

failed:
	local_irq_restore(flags);
	put_cpu();
	return NULL;
L
Linus Torvalds 已提交
1118 1119
}

R
Rohit Seth 已提交
1120
#define ALLOC_NO_WATERMARKS	0x01 /* don't check watermarks at all */
1121 1122 1123 1124 1125 1126
#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
1127

1128 1129 1130 1131 1132 1133 1134
#ifdef CONFIG_FAIL_PAGE_ALLOC

static struct fail_page_alloc_attr {
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1135
	u32 min_order;
1136 1137 1138 1139 1140

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

	struct dentry *ignore_gfp_highmem_file;
	struct dentry *ignore_gfp_wait_file;
1141
	struct dentry *min_order_file;
1142 1143 1144 1145 1146

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1147 1148
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1149
	.min_order = 1,
1150 1151 1152 1153 1154 1155 1156 1157 1158 1159
};

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)
{
1160 1161
	if (order < fail_page_alloc.min_order)
		return 0;
1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192
	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);
1193 1194 1195
	fail_page_alloc.min_order_file =
		debugfs_create_u32("min-order", mode, dir,
				   &fail_page_alloc.min_order);
1196 1197

	if (!fail_page_alloc.ignore_gfp_wait_file ||
1198 1199
            !fail_page_alloc.ignore_gfp_highmem_file ||
            !fail_page_alloc.min_order_file) {
1200 1201 1202
		err = -ENOMEM;
		debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
		debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
1203
		debugfs_remove(fail_page_alloc.min_order_file);
1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222
		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
1223 1224 1225 1226 1227
/*
 * 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
1228
		      int classzone_idx, int alloc_flags)
L
Linus Torvalds 已提交
1229 1230
{
	/* free_pages my go negative - that's OK */
1231 1232
	long min = mark;
	long free_pages = zone_page_state(z, NR_FREE_PAGES) - (1 << order) + 1;
L
Linus Torvalds 已提交
1233 1234
	int o;

R
Rohit Seth 已提交
1235
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1236
		min -= min / 2;
R
Rohit Seth 已提交
1237
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254
		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;
}

1255 1256 1257 1258 1259 1260
#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
1261
 * that have to skip over a lot of full or unallowed zones.
1262 1263 1264
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1265
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286
 *
 * If the zonelist cache is not available for this zonelist, does
 * nothing and returns NULL.
 *
 * If the fullzones BITMAP in the zonelist cache is stale (more than
 * a second since last zap'd) then we zap it out (clear its bits.)
 *
 * We hold off even calling zlc_setup, until after we've checked the
 * first zone in the zonelist, on the theory that most allocations will
 * be satisfied from that first zone, so best to examine that zone as
 * quickly as we can.
 */
static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	nodemask_t *allowednodes;	/* zonelist_cache approximation */

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

S
S.Caglar Onur 已提交
1287
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1288 1289 1290 1291 1292 1293
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1294
					&node_states[N_HIGH_MEMORY];
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
	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.
 */
1320
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1321 1322 1323 1324 1325 1326 1327 1328 1329 1330
						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;

1331
	i = z - zonelist->_zonerefs;
1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342
	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.
 */
1343
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1344 1345 1346 1347 1348 1349 1350 1351
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

1352
	i = z - zonelist->_zonerefs;
1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363

	set_bit(i, zlc->fullzones);
}

#else	/* CONFIG_NUMA */

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

1364
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1365 1366 1367 1368 1369
				nodemask_t *allowednodes)
{
	return 1;
}

1370
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1371 1372 1373 1374
{
}
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1375
/*
1376
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1377 1378 1379
 * a page.
 */
static struct page *
1380
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1381
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags)
M
Martin Hicks 已提交
1382
{
1383
	struct zoneref *z;
R
Rohit Seth 已提交
1384
	struct page *page = NULL;
1385
	int classzone_idx;
1386
	struct zone *zone, *preferred_zone;
1387 1388 1389
	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 */
1390

1391 1392 1393
	(void)first_zones_zonelist(zonelist, high_zoneidx, nodemask,
							&preferred_zone);
	classzone_idx = zone_idx(preferred_zone);
R
Rohit Seth 已提交
1394

1395
zonelist_scan:
R
Rohit Seth 已提交
1396
	/*
1397
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1398 1399
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1400 1401
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1402 1403 1404
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1405
		if ((alloc_flags & ALLOC_CPUSET) &&
1406
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1407
				goto try_next_zone;
R
Rohit Seth 已提交
1408 1409

		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1410 1411
			unsigned long mark;
			if (alloc_flags & ALLOC_WMARK_MIN)
1412
				mark = zone->pages_min;
1413
			else if (alloc_flags & ALLOC_WMARK_LOW)
1414
				mark = zone->pages_low;
1415
			else
1416
				mark = zone->pages_high;
1417 1418
			if (!zone_watermark_ok(zone, order, mark,
				    classzone_idx, alloc_flags)) {
1419
				if (!zone_reclaim_mode ||
1420
				    !zone_reclaim(zone, gfp_mask, order))
1421
					goto this_zone_full;
1422
			}
R
Rohit Seth 已提交
1423 1424
		}

1425
		page = buffered_rmqueue(preferred_zone, zone, order, gfp_mask);
1426
		if (page)
R
Rohit Seth 已提交
1427
			break;
1428 1429 1430 1431 1432 1433 1434 1435 1436 1437
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;
		}
1438
	}
1439 1440 1441 1442 1443 1444

	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
1445
	return page;
M
Martin Hicks 已提交
1446 1447
}

L
Linus Torvalds 已提交
1448 1449 1450
/*
 * This is the 'heart' of the zoned buddy allocator.
 */
1451 1452 1453
static struct page *
__alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
			struct zonelist *zonelist, nodemask_t *nodemask)
L
Linus Torvalds 已提交
1454
{
A
Al Viro 已提交
1455
	const gfp_t wait = gfp_mask & __GFP_WAIT;
1456
	enum zone_type high_zoneidx = gfp_zone(gfp_mask);
1457 1458
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
1459 1460 1461 1462
	struct page *page;
	struct reclaim_state reclaim_state;
	struct task_struct *p = current;
	int do_retry;
R
Rohit Seth 已提交
1463
	int alloc_flags;
L
Linus Torvalds 已提交
1464 1465 1466 1467
	int did_some_progress;

	might_sleep_if(wait);

1468 1469 1470
	if (should_fail_alloc_page(gfp_mask, order))
		return NULL;

1471
restart:
1472
	z = zonelist->_zonerefs;  /* the list of zones suitable for gfp_mask */
L
Linus Torvalds 已提交
1473

1474
	if (unlikely(!z->zone)) {
1475 1476 1477 1478
		/*
		 * 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
1479 1480
		return NULL;
	}
1481

1482
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
1483
			zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET);
R
Rohit Seth 已提交
1484 1485
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1486

1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497
	/*
	 * 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;

1498 1499
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
		wakeup_kswapd(zone, order);
L
Linus Torvalds 已提交
1500

1501
	/*
R
Rohit Seth 已提交
1502 1503 1504 1505 1506 1507
	 * 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
1508 1509
	 * policy or is asking for __GFP_HIGH memory.  GFP_ATOMIC requests will
	 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
1510
	 */
1511
	alloc_flags = ALLOC_WMARK_MIN;
R
Rohit Seth 已提交
1512 1513 1514 1515
	if ((unlikely(rt_task(p)) && !in_interrupt()) || !wait)
		alloc_flags |= ALLOC_HARDER;
	if (gfp_mask & __GFP_HIGH)
		alloc_flags |= ALLOC_HIGH;
1516 1517
	if (wait)
		alloc_flags |= ALLOC_CPUSET;
L
Linus Torvalds 已提交
1518 1519 1520

	/*
	 * Go through the zonelist again. Let __GFP_HIGH and allocations
R
Rohit Seth 已提交
1521
	 * coming from realtime tasks go deeper into reserves.
L
Linus Torvalds 已提交
1522 1523 1524
	 *
	 * This is the last chance, in general, before the goto nopage.
	 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
1525
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
L
Linus Torvalds 已提交
1526
	 */
1527
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
1528
						high_zoneidx, alloc_flags);
R
Rohit Seth 已提交
1529 1530
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
1531 1532

	/* This allocation should allow future memory freeing. */
1533

1534
rebalance:
1535 1536 1537
	if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
			&& !in_interrupt()) {
		if (!(gfp_mask & __GFP_NOMEMALLOC)) {
K
Kirill Korotaev 已提交
1538
nofail_alloc:
1539
			/* go through the zonelist yet again, ignoring mins */
1540
			page = get_page_from_freelist(gfp_mask, nodemask, order,
1541
				zonelist, high_zoneidx, ALLOC_NO_WATERMARKS);
R
Rohit Seth 已提交
1542 1543
			if (page)
				goto got_pg;
K
Kirill Korotaev 已提交
1544
			if (gfp_mask & __GFP_NOFAIL) {
1545
				congestion_wait(WRITE, HZ/50);
K
Kirill Korotaev 已提交
1546 1547
				goto nofail_alloc;
			}
L
Linus Torvalds 已提交
1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558
		}
		goto nopage;
	}

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

	cond_resched();

	/* We now go into synchronous reclaim */
1559
	cpuset_memory_pressure_bump();
L
Linus Torvalds 已提交
1560 1561 1562 1563
	p->flags |= PF_MEMALLOC;
	reclaim_state.reclaimed_slab = 0;
	p->reclaim_state = &reclaim_state;

1564
	did_some_progress = try_to_free_pages(zonelist, order, gfp_mask);
L
Linus Torvalds 已提交
1565 1566 1567 1568 1569 1570

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

	cond_resched();

1571
	if (order != 0)
1572
		drain_all_pages();
1573

L
Linus Torvalds 已提交
1574
	if (likely(did_some_progress)) {
1575
		page = get_page_from_freelist(gfp_mask, nodemask, order,
1576
					zonelist, high_zoneidx, alloc_flags);
R
Rohit Seth 已提交
1577 1578
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
1579
	} else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
1580
		if (!try_set_zone_oom(zonelist, gfp_mask)) {
1581 1582 1583 1584
			schedule_timeout_uninterruptible(1);
			goto restart;
		}

L
Linus Torvalds 已提交
1585 1586 1587 1588 1589 1590
		/*
		 * 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.
		 */
1591 1592 1593
		page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
			order, zonelist, high_zoneidx,
			ALLOC_WMARK_HIGH|ALLOC_CPUSET);
1594
		if (page) {
1595
			clear_zonelist_oom(zonelist, gfp_mask);
R
Rohit Seth 已提交
1596
			goto got_pg;
1597
		}
L
Linus Torvalds 已提交
1598

1599
		/* The OOM killer will not help higher order allocs so fail */
1600
		if (order > PAGE_ALLOC_COSTLY_ORDER) {
1601
			clear_zonelist_oom(zonelist, gfp_mask);
1602
			goto nopage;
1603
		}
1604

1605
		out_of_memory(zonelist, gfp_mask, order);
1606
		clear_zonelist_oom(zonelist, gfp_mask);
L
Linus Torvalds 已提交
1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618
		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
1619 1620
		if ((order <= PAGE_ALLOC_COSTLY_ORDER) ||
						(gfp_mask & __GFP_REPEAT))
L
Linus Torvalds 已提交
1621 1622 1623 1624 1625
			do_retry = 1;
		if (gfp_mask & __GFP_NOFAIL)
			do_retry = 1;
	}
	if (do_retry) {
1626
		congestion_wait(WRITE, HZ/50);
L
Linus Torvalds 已提交
1627 1628 1629 1630 1631 1632 1633 1634 1635
		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
1636
		show_mem();
L
Linus Torvalds 已提交
1637 1638 1639 1640 1641
	}
got_pg:
	return page;
}

1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655
struct page *
__alloc_pages(gfp_t gfp_mask, unsigned int order,
		struct zonelist *zonelist)
{
	return __alloc_pages_internal(gfp_mask, order, zonelist, NULL);
}

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

L
Linus Torvalds 已提交
1656 1657 1658 1659 1660
EXPORT_SYMBOL(__alloc_pages);

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
1661
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
1662 1663 1664 1665 1666 1667 1668 1669 1670 1671
{
	struct page * page;
	page = alloc_pages(gfp_mask, order);
	if (!page)
		return 0;
	return (unsigned long) page_address(page);
}

EXPORT_SYMBOL(__get_free_pages);

H
Harvey Harrison 已提交
1672
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
1673 1674 1675 1676 1677 1678 1679
{
	struct page * page;

	/*
	 * get_zeroed_page() returns a 32-bit address, which cannot represent
	 * a highmem page
	 */
N
Nick Piggin 已提交
1680
	VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
L
Linus Torvalds 已提交
1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697

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

EXPORT_SYMBOL(get_zeroed_page);

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

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

H
Harvey Harrison 已提交
1698
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
1699
{
N
Nick Piggin 已提交
1700
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
1701 1702 1703 1704 1705 1706 1707 1708 1709
		if (order == 0)
			free_hot_page(page);
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
1710
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
1711 1712
{
	if (addr != 0) {
N
Nick Piggin 已提交
1713
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
1714 1715 1716 1717 1718 1719 1720 1721
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

static unsigned int nr_free_zone_pages(int offset)
{
1722
	struct zoneref *z;
1723 1724
	struct zone *zone;

1725
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
1726 1727
	unsigned int sum = 0;

1728
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
1729

1730
	for_each_zone_zonelist(zone, z, zonelist, offset) {
1731 1732 1733 1734
		unsigned long size = zone->present_pages;
		unsigned long high = zone->pages_high;
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
1735 1736 1737 1738 1739 1740 1741 1742 1743 1744
	}

	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
1745
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
1746
}
1747
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
1748 1749 1750 1751 1752 1753

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
1754
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
1755
}
1756 1757

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
1758
{
1759
	if (NUMA_BUILD)
1760
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
1761 1762 1763 1764 1765 1766
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
1767
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781
	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;
1782
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
1783
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
1784
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
1785 1786
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
1787 1788 1789 1790
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803
	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)
{
1804
	int cpu;
L
Linus Torvalds 已提交
1805 1806 1807
	struct zone *zone;

	for_each_zone(zone) {
1808
		if (!populated_zone(zone))
L
Linus Torvalds 已提交
1809
			continue;
1810 1811 1812

		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
1813

1814
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
1815 1816
			struct per_cpu_pageset *pageset;

1817
			pageset = zone_pcp(zone, cpu);
L
Linus Torvalds 已提交
1818

1819 1820 1821
			printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
			       cpu, pageset->pcp.high,
			       pageset->pcp.batch, pageset->pcp.count);
L
Linus Torvalds 已提交
1822 1823 1824
		}
	}

1825
	printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu\n"
1826
		" free:%lu slab:%lu mapped:%lu pagetables:%lu bounce:%lu\n",
1827 1828
		global_page_state(NR_ACTIVE),
		global_page_state(NR_INACTIVE),
1829
		global_page_state(NR_FILE_DIRTY),
1830
		global_page_state(NR_WRITEBACK),
1831
		global_page_state(NR_UNSTABLE_NFS),
1832
		global_page_state(NR_FREE_PAGES),
1833 1834
		global_page_state(NR_SLAB_RECLAIMABLE) +
			global_page_state(NR_SLAB_UNRECLAIMABLE),
1835
		global_page_state(NR_FILE_MAPPED),
1836 1837
		global_page_state(NR_PAGETABLE),
		global_page_state(NR_BOUNCE));
L
Linus Torvalds 已提交
1838 1839 1840 1841

	for_each_zone(zone) {
		int i;

1842 1843 1844
		if (!populated_zone(zone))
			continue;

L
Linus Torvalds 已提交
1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857
		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,
1858
			K(zone_page_state(zone, NR_FREE_PAGES)),
L
Linus Torvalds 已提交
1859 1860 1861
			K(zone->pages_min),
			K(zone->pages_low),
			K(zone->pages_high),
1862 1863
			K(zone_page_state(zone, NR_ACTIVE)),
			K(zone_page_state(zone, NR_INACTIVE)),
L
Linus Torvalds 已提交
1864 1865
			K(zone->present_pages),
			zone->pages_scanned,
1866
			(zone_is_all_unreclaimable(zone) ? "yes" : "no")
L
Linus Torvalds 已提交
1867 1868 1869 1870 1871 1872 1873 1874
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

	for_each_zone(zone) {
1875
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
L
Linus Torvalds 已提交
1876

1877 1878 1879
		if (!populated_zone(zone))
			continue;

L
Linus Torvalds 已提交
1880 1881 1882 1883 1884
		show_node(zone);
		printk("%s: ", zone->name);

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
1885 1886
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
L
Linus Torvalds 已提交
1887 1888
		}
		spin_unlock_irqrestore(&zone->lock, flags);
1889 1890
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
L
Linus Torvalds 已提交
1891 1892 1893
		printk("= %lukB\n", K(total));
	}

1894 1895
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

L
Linus Torvalds 已提交
1896 1897 1898
	show_swap_cache_info();
}

1899 1900 1901 1902 1903 1904
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
{
	zoneref->zone = zone;
	zoneref->zone_idx = zone_idx(zone);
}

L
Linus Torvalds 已提交
1905 1906
/*
 * Builds allocation fallback zone lists.
1907 1908
 *
 * Add all populated zones of a node to the zonelist.
L
Linus Torvalds 已提交
1909
 */
1910 1911
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
1912
{
1913 1914
	struct zone *zone;

1915
	BUG_ON(zone_type >= MAX_NR_ZONES);
1916
	zone_type++;
1917 1918

	do {
1919
		zone_type--;
1920
		zone = pgdat->node_zones + zone_type;
1921
		if (populated_zone(zone)) {
1922 1923
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
1924
			check_highest_zone(zone_type);
L
Linus Torvalds 已提交
1925
		}
1926

1927
	} while (zone_type);
1928
	return nr_zones;
L
Linus Torvalds 已提交
1929 1930
}

1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951

/*
 *  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
1952
#ifdef CONFIG_NUMA
1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
/* 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
2024
#define MAX_NODE_LOAD (num_online_nodes())
2025 2026
static int node_load[MAX_NUMNODES];

L
Linus Torvalds 已提交
2027
/**
2028
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
Linus Torvalds 已提交
2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040
 * @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.
 */
2041
static int find_next_best_node(int node, nodemask_t *used_node_mask)
L
Linus Torvalds 已提交
2042
{
2043
	int n, val;
L
Linus Torvalds 已提交
2044 2045
	int min_val = INT_MAX;
	int best_node = -1;
2046
	node_to_cpumask_ptr(tmp, 0);
L
Linus Torvalds 已提交
2047

2048 2049 2050 2051 2052
	/* 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
2053

2054
	for_each_node_state(n, N_HIGH_MEMORY) {
L
Linus Torvalds 已提交
2055 2056 2057 2058 2059 2060 2061 2062

		/* 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);

2063 2064 2065
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
Linus Torvalds 已提交
2066
		/* Give preference to headless and unused nodes */
2067 2068
		node_to_cpumask_ptr_next(tmp, n);
		if (!cpus_empty(*tmp))
L
Linus Torvalds 已提交
2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086
			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;
}

2087 2088 2089 2090 2091 2092 2093

/*
 * 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
2094
{
2095
	int j;
L
Linus Torvalds 已提交
2096
	struct zonelist *zonelist;
2097

2098
	zonelist = &pgdat->node_zonelists[0];
2099
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
2100 2101 2102
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
2103 2104
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2105 2106
}

2107 2108 2109 2110 2111 2112 2113 2114
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

2115 2116
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
2117 2118
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
2119 2120
}

2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135
/*
 * Build zonelists ordered by zone and nodes within zones.
 * This results in conserving DMA zone[s] until all Normal memory is
 * exhausted, but results in overflowing to remote node while memory
 * may still exist in local DMA zone.
 */
static int node_order[MAX_NUMNODES];

static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
{
	int pos, j, node;
	int zone_type;		/* needs to be signed */
	struct zone *z;
	struct zonelist *zonelist;

2136 2137 2138 2139 2140 2141 2142
	zonelist = &pgdat->node_zonelists[0];
	pos = 0;
	for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
		for (j = 0; j < nr_nodes; j++) {
			node = node_order[j];
			z = &NODE_DATA(node)->node_zones[zone_type];
			if (populated_zone(z)) {
2143 2144
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
2145
				check_highest_zone(zone_type);
2146 2147 2148
			}
		}
	}
2149 2150
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185
}

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.
         */
2186 2187
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218
	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
2219
	nodemask_t used_mask;
2220 2221 2222
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
L
Linus Torvalds 已提交
2223 2224

	/* initialize zonelists */
2225
	for (i = 0; i < MAX_ZONELISTS; i++) {
L
Linus Torvalds 已提交
2226
		zonelist = pgdat->node_zonelists + i;
2227 2228
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
L
Linus Torvalds 已提交
2229 2230 2231 2232 2233 2234 2235
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
	load = num_online_nodes();
	prev_node = local_node;
	nodes_clear(used_mask);
2236 2237 2238 2239 2240

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

L
Linus Torvalds 已提交
2241
	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
2242 2243 2244 2245 2246 2247 2248 2249 2250
		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
2251 2252 2253 2254 2255
		/*
		 * 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.
		 */
2256
		if (distance != node_distance(local_node, prev_node))
2257 2258
			node_load[node] = load;

L
Linus Torvalds 已提交
2259 2260
		prev_node = node;
		load--;
2261 2262 2263 2264 2265
		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
2266

2267 2268 2269
	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
2270
	}
2271 2272

	build_thisnode_zonelists(pgdat);
L
Linus Torvalds 已提交
2273 2274
}

2275
/* Construct the zonelist performance cache - see further mmzone.h */
2276
static void build_zonelist_cache(pg_data_t *pgdat)
2277
{
2278 2279
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
2280
	struct zoneref *z;
2281

2282 2283 2284
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
2285 2286
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
2287 2288
}

2289

L
Linus Torvalds 已提交
2290 2291
#else	/* CONFIG_NUMA */

2292 2293 2294 2295 2296 2297
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
2298
{
2299
	int node, local_node;
2300 2301
	enum zone_type j;
	struct zonelist *zonelist;
L
Linus Torvalds 已提交
2302 2303 2304

	local_node = pgdat->node_id;

2305 2306
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
2307

2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320
	/*
	 * Now we build the zonelist so that it contains the zones
	 * of all the other nodes.
	 * We don't want to pressure a particular node, so when
	 * building the zones for node N, we make sure that the
	 * zones coming right after the local ones are those from
	 * node N+1 (modulo N)
	 */
	for (node = local_node + 1; node < MAX_NUMNODES; node++) {
		if (!node_online(node))
			continue;
		j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
2321
	}
2322 2323 2324 2325 2326 2327 2328
	for (node = 0; node < local_node; node++) {
		if (!node_online(node))
			continue;
		j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
	}

2329 2330
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
L
Linus Torvalds 已提交
2331 2332
}

2333
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
2334
static void build_zonelist_cache(pg_data_t *pgdat)
2335
{
2336 2337
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
	pgdat->node_zonelists[1].zlcache_ptr = NULL;
2338 2339
}

L
Linus Torvalds 已提交
2340 2341
#endif	/* CONFIG_NUMA */

2342
/* return values int ....just for stop_machine_run() */
2343
static int __build_all_zonelists(void *dummy)
L
Linus Torvalds 已提交
2344
{
2345
	int nid;
2346 2347

	for_each_online_node(nid) {
2348 2349 2350 2351
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
2352
	}
2353 2354 2355
	return 0;
}

2356
void build_all_zonelists(void)
2357
{
2358 2359
	set_zonelist_order();

2360
	if (system_state == SYSTEM_BOOTING) {
2361
		__build_all_zonelists(NULL);
2362 2363
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
2364
		/* we have to stop all cpus to guarantee there is no user
2365 2366 2367 2368
		   of zonelist */
		stop_machine_run(__build_all_zonelists, NULL, NR_CPUS);
		/* cpuset refresh routine should be here */
	}
2369
	vm_total_pages = nr_free_pagecache_pages();
2370 2371 2372 2373 2374 2375 2376
	/*
	 * 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
	 */
2377
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
2378 2379 2380 2381 2382 2383
		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",
2384 2385
			num_online_nodes(),
			zonelist_order_name[current_zonelist_order],
2386
			page_group_by_mobility_disabled ? "off" : "on",
2387 2388 2389 2390
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
L
Linus Torvalds 已提交
2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405
}

/*
 * 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

2406
#ifndef CONFIG_MEMORY_HOTPLUG
2407
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424
{
	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);
}
2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447
#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
2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460

/*
 * 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))

2461
/*
2462
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476
 * 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;
2477 2478
	reserve = roundup(zone->pages_min, pageblock_nr_pages) >>
							pageblock_order;
2479

2480
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514
		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
2515

L
Linus Torvalds 已提交
2516 2517 2518 2519 2520
/*
 * 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.
 */
2521
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
2522
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
2523 2524
{
	struct page *page;
A
Andy Whitcroft 已提交
2525 2526
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
L
Linus Torvalds 已提交
2527

2528
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539
		/*
		 * 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
2540 2541
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
2542
		init_page_count(page);
L
Linus Torvalds 已提交
2543 2544
		reset_page_mapcount(page);
		SetPageReserved(page);
2545 2546 2547 2548 2549 2550

		/*
		 * 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
2551 2552 2553
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
2554
		 */
2555
		if ((pfn & (pageblock_nr_pages-1)))
2556
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
2557

L
Linus Torvalds 已提交
2558 2559 2560 2561
		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))
2562
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
2563 2564 2565 2566
#endif
	}
}

2567
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
2568
{
2569 2570 2571
	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
2572 2573 2574 2575 2576 2577
		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
2578
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
2579 2580
#endif

2581
static int zone_batchsize(struct zone *zone)
2582 2583 2584 2585 2586
{
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
2587
	 * size of the zone.  But no more than 1/2 of a meg.
2588 2589 2590 2591
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
2592 2593
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
2594 2595 2596 2597 2598
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
2599 2600 2601
	 * 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.
2602
	 *
2603 2604 2605 2606
	 * 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.
2607
	 */
2608
	batch = (1 << (fls(batch + batch/2)-1)) - 1;
2609

2610 2611 2612
	return batch;
}

2613 2614 2615 2616
inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
{
	struct per_cpu_pages *pcp;

2617 2618
	memset(p, 0, sizeof(*p));

2619
	pcp = &p->pcp;
2620 2621 2622 2623 2624 2625
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
	INIT_LIST_HEAD(&pcp->list);
}

2626 2627 2628 2629 2630 2631 2632 2633 2634 2635
/*
 * 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;

2636
	pcp = &p->pcp;
2637 2638 2639 2640 2641 2642 2643
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}


2644 2645
#ifdef CONFIG_NUMA
/*
2646 2647 2648 2649 2650 2651 2652
 * 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.
2653 2654 2655 2656 2657 2658 2659 2660
 *
 * 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.
2661
 */
2662
static struct per_cpu_pageset boot_pageset[NR_CPUS];
2663 2664 2665

/*
 * Dynamically allocate memory for the
2666 2667
 * per cpu pageset array in struct zone.
 */
2668
static int __cpuinit process_zones(int cpu)
2669 2670
{
	struct zone *zone, *dzone;
2671 2672 2673
	int node = cpu_to_node(cpu);

	node_set_state(node, N_CPU);	/* this node has a cpu */
2674 2675 2676

	for_each_zone(zone) {

2677 2678 2679
		if (!populated_zone(zone))
			continue;

N
Nick Piggin 已提交
2680
		zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
2681
					 GFP_KERNEL, node);
N
Nick Piggin 已提交
2682
		if (!zone_pcp(zone, cpu))
2683 2684
			goto bad;

N
Nick Piggin 已提交
2685
		setup_pageset(zone_pcp(zone, cpu), zone_batchsize(zone));
2686 2687 2688 2689

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(zone_pcp(zone, cpu),
			 	(zone->present_pages / percpu_pagelist_fraction));
2690 2691 2692 2693 2694
	}

	return 0;
bad:
	for_each_zone(dzone) {
2695 2696
		if (!populated_zone(dzone))
			continue;
2697 2698
		if (dzone == zone)
			break;
N
Nick Piggin 已提交
2699 2700
		kfree(zone_pcp(dzone, cpu));
		zone_pcp(dzone, cpu) = NULL;
2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711
	}
	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);

2712 2713 2714
		/* Free per_cpu_pageset if it is slab allocated */
		if (pset != &boot_pageset[cpu])
			kfree(pset);
2715 2716 2717 2718
		zone_pcp(zone, cpu) = NULL;
	}
}

2719
static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb,
2720 2721 2722 2723 2724 2725 2726
		unsigned long action,
		void *hcpu)
{
	int cpu = (long)hcpu;
	int ret = NOTIFY_OK;

	switch (action) {
2727
	case CPU_UP_PREPARE:
2728
	case CPU_UP_PREPARE_FROZEN:
2729 2730 2731 2732
		if (process_zones(cpu))
			ret = NOTIFY_BAD;
		break;
	case CPU_UP_CANCELED:
2733
	case CPU_UP_CANCELED_FROZEN:
2734
	case CPU_DEAD:
2735
	case CPU_DEAD_FROZEN:
2736 2737 2738 2739
		free_zone_pagesets(cpu);
		break;
	default:
		break;
2740 2741 2742 2743
	}
	return ret;
}

2744
static struct notifier_block __cpuinitdata pageset_notifier =
2745 2746
	{ &pageset_cpuup_callback, NULL, 0 };

2747
void __init setup_per_cpu_pageset(void)
2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761
{
	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
2762
static noinline __init_refok
2763
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
2764 2765 2766
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
2767
	size_t alloc_size;
2768 2769 2770 2771 2772

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
2773 2774 2775 2776
	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);
2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793
	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.
		 */
2794
		zone->wait_table = vmalloc(alloc_size);
2795 2796 2797
	}
	if (!zone->wait_table)
		return -ENOMEM;
2798

2799
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
2800
		init_waitqueue_head(zone->wait_table + i);
2801 2802

	return 0;
2803 2804
}

2805
static __meminit void zone_pcp_init(struct zone *zone)
2806 2807 2808 2809 2810 2811 2812
{
	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
2813
		zone_pcp(zone, cpu) = &boot_pageset[cpu];
2814 2815 2816 2817 2818
		setup_pageset(&boot_pageset[cpu],0);
#else
		setup_pageset(zone_pcp(zone,cpu), batch);
#endif
	}
A
Anton Blanchard 已提交
2819 2820 2821
	if (zone->present_pages)
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%lu\n",
			zone->name, zone->present_pages, batch);
2822 2823
}

2824 2825
__meminit int init_currently_empty_zone(struct zone *zone,
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
2826 2827
					unsigned long size,
					enum memmap_context context)
2828 2829
{
	struct pglist_data *pgdat = zone->zone_pgdat;
2830 2831 2832 2833
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
2834 2835 2836 2837 2838 2839
	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);

2840
	zone_init_free_lists(zone);
2841 2842

	return 0;
2843 2844
}

2845 2846 2847 2848 2849
#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
 */
2850
static int __meminit first_active_region_index_in_nid(int nid)
2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862
{
	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
2863
 * Note: nid == MAX_NUMNODES returns next region regardless of node
2864
 */
2865
static int __meminit next_active_region_index_in_nid(int index, int nid)
2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880
{
	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
 */
2881
int __meminit early_pfn_to_nid(unsigned long pfn)
2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903
{
	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
2904 2905
 * @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
2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934
 *
 * 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
2935
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
2936 2937 2938
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
2939
 * function may be used instead of calling memory_present() manually.
2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950
 */
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);
}

2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981
/**
 * 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 */
2982
static void __meminit account_node_boundary(unsigned int nid,
2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001
		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) {}

3002
static void __meminit account_node_boundary(unsigned int nid,
3003 3004 3005 3006
		unsigned long *start_pfn, unsigned long *end_pfn) {}
#endif


3007 3008
/**
 * get_pfn_range_for_nid - Return the start and end page frames for a node
3009 3010 3011
 * @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.
3012 3013 3014 3015
 *
 * 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
3016
 * PFNs will be 0.
3017
 */
3018
void __meminit get_pfn_range_for_nid(unsigned int nid,
3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029
			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);
	}

3030
	if (*start_pfn == -1UL)
3031
		*start_pfn = 0;
3032 3033 3034

	/* Push the node boundaries out if requested */
	account_node_boundary(nid, start_pfn, end_pfn);
3035 3036
}

M
Mel Gorman 已提交
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 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093
/*
 * 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;
	}
}

3094 3095 3096 3097
/*
 * 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
3098
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
3099 3100 3101 3102 3103 3104 3105 3106 3107 3108
					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
3109 3110 3111
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126

	/* 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,
3127
 * then all holes in the requested range will be accounted for.
3128
 */
3129
unsigned long __meminit __absent_pages_in_range(int nid,
3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141
				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;

3142 3143
	prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);

3144 3145
	/* Account for ranges before physical memory on this node */
	if (early_node_map[i].start_pfn > range_start_pfn)
3146
		hole_pages = prev_end_pfn - range_start_pfn;
3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166

	/* 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;
	}

3167 3168
	/* Account for ranges past physical memory on this node */
	if (range_end_pfn > prev_end_pfn)
3169
		hole_pages += range_end_pfn -
3170 3171
				max(range_start_pfn, prev_end_pfn);

3172 3173 3174 3175 3176 3177 3178 3179
	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
 *
3180
 * It returns the number of pages frames in memory holes within a range.
3181 3182 3183 3184 3185 3186 3187 3188
 */
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
3189
static unsigned long __meminit zone_absent_pages_in_node(int nid,
3190 3191 3192
					unsigned long zone_type,
					unsigned long *ignored)
{
3193 3194 3195 3196 3197 3198 3199 3200 3201
	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
3202 3203 3204
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
3205
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
3206
}
3207

3208
#else
P
Paul Mundt 已提交
3209
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
3210 3211 3212 3213 3214 3215
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
3216
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
3217 3218 3219 3220 3221 3222 3223 3224
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
3225

3226 3227
#endif

3228
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248
		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);
}

3249 3250 3251
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
3252 3253
 * 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
3254 3255 3256 3257 3258 3259 3260
 * 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;

3261 3262
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283
	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 */

3284
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
3285 3286 3287 3288 3289 3290 3291 3292 3293 3294

/* Return a sensible default order for the pageblock size. */
static inline int pageblock_default_order(void)
{
	if (HPAGE_SHIFT > PAGE_SHIFT)
		return HUGETLB_PAGE_ORDER;

	return MAX_ORDER-1;
}

3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309
/* 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 */

3310 3311 3312 3313 3314 3315 3316 3317 3318 3319
/*
 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
 * and pageblock_default_order() are unused as pageblock_order is set
 * at compile-time. See include/linux/pageblock-flags.h for the values of
 * pageblock_order based on the kernel config
 */
static inline int pageblock_default_order(unsigned int order)
{
	return MAX_ORDER-1;
}
3320 3321 3322 3323
#define set_pageblock_order(x)	do {} while (0)

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
3324 3325 3326 3327 3328 3329
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
 */
3330
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3331 3332
		unsigned long *zones_size, unsigned long *zholes_size)
{
3333
	enum zone_type j;
3334
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
3335
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
3336
	int ret;
L
Linus Torvalds 已提交
3337

3338
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
3339 3340 3341 3342 3343 3344
	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;
3345
		unsigned long size, realsize, memmap_pages;
L
Linus Torvalds 已提交
3346

3347 3348 3349
		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
3350

3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366
		/*
		 * 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);

3367 3368
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
3369
			realsize -= dma_reserve;
3370 3371
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
					zone_names[0], dma_reserve);
3372 3373
		}

3374
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
3375 3376 3377 3378 3379
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
3380
#ifdef CONFIG_NUMA
3381
		zone->node = nid;
3382
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
3383
						/ 100;
3384
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
3385
#endif
L
Linus Torvalds 已提交
3386 3387 3388
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
3389
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
3390 3391
		zone->zone_pgdat = pgdat;

3392
		zone->prev_priority = DEF_PRIORITY;
L
Linus Torvalds 已提交
3393

3394
		zone_pcp_init(zone);
L
Linus Torvalds 已提交
3395 3396 3397 3398
		INIT_LIST_HEAD(&zone->active_list);
		INIT_LIST_HEAD(&zone->inactive_list);
		zone->nr_scan_active = 0;
		zone->nr_scan_inactive = 0;
3399
		zap_zone_vm_stats(zone);
3400
		zone->flags = 0;
L
Linus Torvalds 已提交
3401 3402 3403
		if (!size)
			continue;

3404
		set_pageblock_order(pageblock_default_order());
3405
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
3406 3407
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
3408
		BUG_ON(ret);
L
Linus Torvalds 已提交
3409 3410 3411 3412
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
3413
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
3414 3415 3416 3417 3418
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
3419
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
3420 3421
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
3422
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
3423 3424
		struct page *map;

3425 3426 3427 3428 3429 3430 3431 3432 3433
		/*
		 * 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);
3434 3435 3436
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
			map = alloc_bootmem_node(pgdat, size);
3437
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
3438
	}
3439
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
3440 3441 3442
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
3443
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
3444
		mem_map = NODE_DATA(0)->node_mem_map;
3445 3446
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
3447
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
3448 3449
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
	}
L
Linus Torvalds 已提交
3450
#endif
A
Andy Whitcroft 已提交
3451
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
3452 3453
}

3454
void __paginginit free_area_init_node(int nid, struct pglist_data *pgdat,
L
Linus Torvalds 已提交
3455 3456 3457 3458 3459
		unsigned long *zones_size, unsigned long node_start_pfn,
		unsigned long *zholes_size)
{
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
3460
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
3461 3462 3463 3464 3465 3466

	alloc_node_mem_map(pgdat);

	free_area_init_core(pgdat, zones_size, zholes_size);
}

3467
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
M
Miklos Szeredi 已提交
3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487

#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

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 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573
/**
 * 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
3574
 *
3575 3576 3577 3578
 * 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.
 */
3579
void __init remove_all_active_ranges(void)
3580 3581 3582
{
	memset(early_node_map, 0, sizeof(early_node_map));
	nr_nodemap_entries = 0;
3583 3584 3585 3586
#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 */
3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611
}

/* 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);
}

3612
/* Find the lowest pfn for a node */
3613 3614 3615
unsigned long __init find_min_pfn_for_node(unsigned long nid)
{
	int i;
3616
	unsigned long min_pfn = ULONG_MAX;
3617

3618 3619
	/* Assuming a sorted map, the first range found has the starting pfn */
	for_each_active_range_index_in_nid(i, nid)
3620
		min_pfn = min(min_pfn, early_node_map[i].start_pfn);
3621

3622 3623 3624 3625 3626 3627 3628
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
			"Could not find start_pfn for node %lu\n", nid);
		return 0;
	}

	return min_pfn;
3629 3630 3631 3632 3633 3634
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
3635
 * add_active_range().
3636 3637 3638 3639 3640 3641 3642 3643 3644 3645
 */
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
3646
 * add_active_range().
3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658
 */
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;
}

3659 3660 3661 3662 3663
/*
 * 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
3664
static unsigned long __init early_calculate_totalpages(void)
3665 3666 3667 3668
{
	int i;
	unsigned long totalpages = 0;

3669 3670
	for (i = 0; i < nr_nodemap_entries; i++) {
		unsigned long pages = early_node_map[i].end_pfn -
3671
						early_node_map[i].start_pfn;
3672 3673 3674 3675 3676
		totalpages += pages;
		if (pages)
			node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
	}
  	return totalpages;
3677 3678
}

M
Mel Gorman 已提交
3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689
/*
 * 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;
3690 3691
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
3692

3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714
	/*
	 * 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
3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725
	/* 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;
3726
	for_each_node_state(nid, N_HIGH_MEMORY) {
M
Mel Gorman 已提交
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 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817
		/*
		 * 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);
}

3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831
/* 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
}

3832 3833
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
3834
 * @max_zone_pfn: an array of max PFNs for each zone
3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849
 *
 * 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;

3850 3851 3852
	/* Sort early_node_map as initialisation assumes it is sorted */
	sort_node_map();

3853 3854 3855 3856 3857 3858 3859 3860
	/* 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
3861 3862
		if (i == ZONE_MOVABLE)
			continue;
3863 3864 3865 3866 3867
		arch_zone_lowest_possible_pfn[i] =
			arch_zone_highest_possible_pfn[i-1];
		arch_zone_highest_possible_pfn[i] =
			max(max_zone_pfn[i], arch_zone_lowest_possible_pfn[i]);
	}
M
Mel Gorman 已提交
3868 3869 3870 3871 3872 3873
	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);
3874 3875 3876

	/* Print out the zone ranges */
	printk("Zone PFN ranges:\n");
M
Mel Gorman 已提交
3877 3878 3879
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
3880 3881 3882 3883
		printk("  %-8s %8lu -> %8lu\n",
				zone_names[i],
				arch_zone_lowest_possible_pfn[i],
				arch_zone_highest_possible_pfn[i]);
M
Mel Gorman 已提交
3884 3885 3886 3887 3888 3889 3890 3891
	}

	/* 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]);
	}
3892 3893 3894 3895 3896 3897 3898 3899 3900

	/* 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 */
3901
	setup_nr_node_ids();
3902 3903 3904 3905
	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);
3906 3907 3908 3909 3910

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
3911 3912
	}
}
M
Mel Gorman 已提交
3913

3914
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
3915 3916 3917 3918 3919 3920
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
3921
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
3922

3923
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
3924 3925 3926 3927
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
3928

3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946
/*
 * 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
3947
early_param("kernelcore", cmdline_parse_kernelcore);
3948
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
3949

3950 3951
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

3952
/**
3953 3954
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
3955 3956 3957 3958
 *
 * 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
3959 3960 3961
 * 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.
3962 3963 3964 3965 3966 3967
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

3968
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
3969 3970 3971 3972
static bootmem_data_t contig_bootmem_data;
struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data };

EXPORT_SYMBOL(contig_page_data);
3973
#endif
L
Linus Torvalds 已提交
3974 3975 3976

void __init free_area_init(unsigned long *zones_size)
{
3977
	free_area_init_node(0, NODE_DATA(0), zones_size,
L
Linus Torvalds 已提交
3978 3979 3980 3981 3982 3983 3984 3985
			__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;

3986
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
3987 3988 3989 3990 3991 3992 3993 3994
		drain_pages(cpu);

		/*
		 * Spill the event counters of the dead processor
		 * into the current processors event counters.
		 * This artificially elevates the count of the current
		 * processor.
		 */
3995
		vm_events_fold_cpu(cpu);
3996 3997 3998 3999 4000 4001 4002 4003

		/*
		 * Zero the differential counters of the dead processor
		 * so that the vm statistics are consistent.
		 *
		 * This is only okay since the processor is dead and cannot
		 * race with what we are doing.
		 */
4004
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
4005 4006 4007 4008 4009 4010 4011 4012 4013
	}
	return NOTIFY_OK;
}

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

4014 4015 4016 4017 4018 4019 4020 4021
/*
 * 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;
4022
	enum zone_type i, j;
4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045

	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;
}

L
Linus Torvalds 已提交
4046 4047 4048 4049 4050 4051 4052 4053 4054
/*
 * 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;
4055
	enum zone_type j, idx;
L
Linus Torvalds 已提交
4056

4057
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
4058 4059 4060 4061 4062 4063
		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;

4064 4065
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
4066 4067
				struct zone *lower_zone;

4068 4069
				idx--;

L
Linus Torvalds 已提交
4070 4071 4072 4073 4074 4075 4076 4077 4078 4079
				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;
			}
		}
	}
4080 4081 4082

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4083 4084
}

4085 4086 4087 4088 4089
/**
 * 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
4090
 */
4091
void setup_per_zone_pages_min(void)
L
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4092 4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103 4104
{
	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) {
4105 4106
		u64 tmp;

L
Linus Torvalds 已提交
4107
		spin_lock_irqsave(&zone->lru_lock, flags);
4108 4109
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
4110 4111
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
4112 4113 4114 4115 4116 4117 4118
			 * __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
4119 4120 4121 4122 4123 4124 4125 4126 4127 4128
			 */
			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
4129 4130
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
4131 4132
			 * proportionate to the zone's size.
			 */
N
Nick Piggin 已提交
4133
			zone->pages_min = tmp;
L
Linus Torvalds 已提交
4134 4135
		}

4136 4137
		zone->pages_low   = zone->pages_min + (tmp >> 2);
		zone->pages_high  = zone->pages_min + (tmp >> 1);
4138
		setup_zone_migrate_reserve(zone);
L
Linus Torvalds 已提交
4139 4140
		spin_unlock_irqrestore(&zone->lru_lock, flags);
	}
4141 4142 4143

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178 4179 4180 4181 4182 4183 4184 4185 4186 4187 4188 4189 4190 4191 4192 4193 4194 4195
}

/*
 * 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);
4196 4197
	if (write)
		setup_per_zone_pages_min();
L
Linus Torvalds 已提交
4198 4199 4200
	return 0;
}

4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212
#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)
4213
		zone->min_unmapped_pages = (zone->present_pages *
4214 4215 4216
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232

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;
}
4233 4234
#endif

L
Linus Torvalds 已提交
4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251
/*
 * 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;
}

4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277
/*
 * 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;
}

4278
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302 4303 4304 4305 4306 4307 4308 4309 4310 4311 4312

#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
4313
		numentries = nr_kernel_pages;
L
Linus Torvalds 已提交
4314 4315 4316 4317 4318 4319 4320 4321 4322
		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);
4323 4324 4325 4326

		/* 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
4327
	}
4328
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
4329 4330 4331 4332 4333 4334 4335 4336 4337 4338

	/* 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;

4339
	log2qty = ilog2(numentries);
L
Linus Torvalds 已提交
4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351

	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);
4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363 4364 4365 4366
			/*
			 * If bucketsize is not a power-of-two, we may free
			 * some pages at the end of hash table.
			 */
			if (table) {
				unsigned long alloc_end = (unsigned long)table +
						(PAGE_SIZE << order);
				unsigned long used = (unsigned long)table +
						PAGE_ALIGN(size);
				split_page(virt_to_page(table), order);
				while (used < alloc_end) {
					free_page(used);
					used += PAGE_SIZE;
				}
			}
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Linus Torvalds 已提交
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		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

4373
	printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
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Linus Torvalds 已提交
4374 4375
	       tablename,
	       (1U << log2qty),
4376
	       ilog2(size) - PAGE_SHIFT,
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	       size);

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

	return table;
}
4386 4387 4388 4389

#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
struct page *pfn_to_page(unsigned long pfn)
{
4390
	return __pfn_to_page(pfn);
4391 4392 4393
}
unsigned long page_to_pfn(struct page *page)
{
4394
	return __page_to_pfn(page);
4395 4396 4397 4398
}
EXPORT_SYMBOL(pfn_to_page);
EXPORT_SYMBOL(page_to_pfn);
#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
4399

4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414
/* 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);
4415
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4416 4417
#else
	pfn = pfn - zone->zone_start_pfn;
4418
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
4419 4420 4421 4422
#endif /* CONFIG_SPARSEMEM */
}

/**
4423
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436 4437 4438 4439 4440 4441 4442 4443 4444 4445
 * @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;
4446

4447 4448 4449 4450
	return flags;
}

/**
4451
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462 4463 4464 4465 4466 4467 4468 4469 4470 4471 4472 4473 4474 4475
 * @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);
}
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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)
4502
		drain_all_pages();
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KAMEZAWA Hiroyuki 已提交
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	return ret;
}

void unset_migratetype_isolate(struct page *page)
{
	struct zone *zone;
	unsigned long flags;
	zone = page_zone(page);
	spin_lock_irqsave(&zone->lock, flags);
	if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
		goto out;
	set_pageblock_migratetype(page, MIGRATE_MOVABLE);
	move_freepages_block(zone, page, MIGRATE_MOVABLE);
out:
	spin_unlock_irqrestore(&zone->lock, flags);
}
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KAMEZAWA Hiroyuki 已提交
4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 4557 4558 4559 4560 4561 4562 4563 4564 4565

#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