page_alloc.c 168.1 KB
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/*
 *  linux/mm/page_alloc.c
 *
 *  Manages the free list, the system allocates free pages here.
 *  Note that kmalloc() lives in slab.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *  Swap reorganised 29.12.95, Stephen Tweedie
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *  Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
 *  Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
 *  Zone balancing, Kanoj Sarcar, SGI, Jan 2000
 *  Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
 *          (lots of bits borrowed from Ingo Molnar & Andrew Morton)
 */

#include <linux/stddef.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/interrupt.h>
#include <linux/pagemap.h>
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#include <linux/jiffies.h>
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#include <linux/bootmem.h>
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#include <linux/memblock.h>
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#include <linux/compiler.h>
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#include <linux/kernel.h>
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#include <linux/kmemcheck.h>
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#include <linux/module.h>
#include <linux/suspend.h>
#include <linux/pagevec.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
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#include <linux/ratelimit.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/vmstat.h>
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#include <linux/mempolicy.h>
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#include <linux/stop_machine.h>
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#include <linux/sort.h>
#include <linux/pfn.h>
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#include <linux/backing-dev.h>
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#include <linux/fault-inject.h>
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#include <linux/page-isolation.h>
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#include <linux/page_cgroup.h>
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#include <linux/debugobjects.h>
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#include <linux/kmemleak.h>
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#include <linux/compaction.h>
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#include <trace/events/kmem.h>
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#include <linux/ftrace_event.h>
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#include <linux/memcontrol.h>
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#include <linux/prefetch.h>
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#include <linux/migrate.h>
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#include <linux/page-debug-flags.h>
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#include <asm/tlbflush.h>
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#include <asm/div64.h>
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#include "internal.h"

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#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
DEFINE_PER_CPU(int, numa_node);
EXPORT_PER_CPU_SYMBOL(numa_node);
#endif

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#ifdef CONFIG_HAVE_MEMORYLESS_NODES
/*
 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem()
 * defined in <linux/topology.h>.
 */
DEFINE_PER_CPU(int, _numa_mem_);		/* Kernel "local memory" node */
EXPORT_PER_CPU_SYMBOL(_numa_mem_);
#endif

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

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unsigned long totalram_pages __read_mostly;
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unsigned long totalreserve_pages __read_mostly;
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/*
 * When calculating the number of globally allowed dirty pages, there
 * is a certain number of per-zone reserves that should not be
 * considered dirtyable memory.  This is the sum of those reserves
 * over all existing zones that contribute dirtyable memory.
 */
unsigned long dirty_balance_reserve __read_mostly;

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

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

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void pm_restrict_gfp_mask(void)
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{
	WARN_ON(!mutex_is_locked(&pm_mutex));
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	WARN_ON(saved_gfp_mask);
	saved_gfp_mask = gfp_allowed_mask;
	gfp_allowed_mask &= ~GFP_IOFS;
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}
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bool pm_suspended_storage(void)
{
	if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS)
		return false;
	return true;
}
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#endif /* CONFIG_PM_SLEEP */

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#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
int pageblock_order __read_mostly;
#endif

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

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

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int min_free_kbytes = 1024;

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static unsigned long __meminitdata nr_kernel_pages;
static unsigned long __meminitdata nr_all_pages;
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static unsigned long __meminitdata dma_reserve;
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#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
static unsigned long __initdata required_kernelcore;
static unsigned long __initdata required_movablecore;
static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];

/* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
int movable_zone;
EXPORT_SYMBOL(movable_zone);
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
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#if MAX_NUMNODES > 1
int nr_node_ids __read_mostly = MAX_NUMNODES;
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int nr_online_nodes __read_mostly = 1;
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EXPORT_SYMBOL(nr_node_ids);
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EXPORT_SYMBOL(nr_online_nodes);
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#endif

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int page_group_by_mobility_disabled __read_mostly;

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/*
 * NOTE:
 * Don't use set_pageblock_migratetype(page, MIGRATE_ISOLATE) directly.
 * Instead, use {un}set_pageblock_isolate.
 */
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void set_pageblock_migratetype(struct page *page, int migratetype)
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{
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	if (unlikely(page_group_by_mobility_disabled))
		migratetype = MIGRATE_UNMOVABLE;

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

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bool oom_killer_disabled __read_mostly;

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

	return ret;
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}

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

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

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

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

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

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

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	printk(KERN_ALERT "BUG: Bad page state in process %s  pfn:%05lx\n",
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		current->comm, page_to_pfn(page));
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	dump_page(page);
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	print_modules();
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	dump_stack();
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out:
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	/* Leave bad fields for debug, except PageBuddy could make trouble */
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	reset_page_mapcount(page); /* remove PageBuddy */
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	add_taint(TAINT_BAD_PAGE);
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}

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

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

	set_compound_page_dtor(page, free_compound_page);
	set_compound_order(page, order);
	__SetPageHead(page);
	for (i = 1; i < nr_pages; i++) {
		struct page *p = page + i;
		__SetPageTail(p);
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		set_page_count(p, 0);
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		p->first_page = page;
	}
}

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

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

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

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#ifdef CONFIG_DEBUG_PAGEALLOC
unsigned int _debug_guardpage_minorder;

static int __init debug_guardpage_minorder_setup(char *buf)
{
	unsigned long res;

	if (kstrtoul(buf, 10, &res) < 0 ||  res > MAX_ORDER / 2) {
		printk(KERN_ERR "Bad debug_guardpage_minorder value\n");
		return 0;
	}
	_debug_guardpage_minorder = res;
	printk(KERN_INFO "Setting debug_guardpage_minorder to %lu\n", res);
	return 0;
}
__setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);

static inline void set_page_guard_flag(struct page *page)
{
	__set_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
}

static inline void clear_page_guard_flag(struct page *page)
{
	__clear_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
}
#else
static inline void set_page_guard_flag(struct page *page) { }
static inline void clear_page_guard_flag(struct page *page) { }
#endif

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

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

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

/*
 * This function checks whether a page is free && is the buddy
 * we can do coalesce a page and its buddy if
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 * (a) the buddy is not in a hole &&
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 * (b) the buddy is in the buddy system &&
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 * (c) a page and its buddy have the same order &&
 * (d) a page and its buddy are in the same zone.
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 *
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 * For recording whether a page is in the buddy system, we set ->_mapcount -2.
 * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
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 *
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 * For recording page's order, we use page_private(page).
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 */
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static inline int page_is_buddy(struct page *page, struct page *buddy,
								int order)
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{
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	if (!pfn_valid_within(page_to_pfn(buddy)))
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		return 0;

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

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

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

/*
 * Freeing function for a buddy system allocator.
 *
 * The concept of a buddy system is to maintain direct-mapped table
 * (containing bit values) for memory blocks of various "orders".
 * The bottom level table contains the map for the smallest allocatable
 * units of memory (here, pages), and each level above it describes
 * pairs of units from the levels below, hence, "buddies".
 * At a high level, all that happens here is marking the table entry
 * at the bottom level available, and propagating the changes upward
 * as necessary, plus some accounting needed to play nicely with other
 * parts of the VM system.
 * At each level, we keep a list of pages, which are heads of continuous
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 * free pages of length of (1 << order) and marked with _mapcount -2. Page's
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 * order is recorded in page_private(page) field.
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 * So when we are allocating or freeing one, we can derive the state of the
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 * other.  That is, if we allocate a small block, and both were
 * free, the remainder of the region must be split into blocks.
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 * If a block is freed, and its buddy is also free, then this
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 * triggers coalescing into a block of larger size.
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 *
 * -- wli
 */

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static inline void __free_one_page(struct page *page,
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		struct zone *zone, unsigned int order,
		int migratetype)
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{
	unsigned long page_idx;
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	unsigned long combined_idx;
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	unsigned long uninitialized_var(buddy_idx);
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	struct page *buddy;
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	if (unlikely(PageCompound(page)))
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		if (unlikely(destroy_compound_page(page, order)))
			return;
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	VM_BUG_ON(migratetype == -1);

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

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	VM_BUG_ON(page_idx & ((1 << order) - 1));
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	VM_BUG_ON(bad_range(zone, page));
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	while (order < MAX_ORDER-1) {
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		buddy_idx = __find_buddy_index(page_idx, order);
		buddy = page + (buddy_idx - page_idx);
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		if (!page_is_buddy(page, buddy, order))
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			break;
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		/*
		 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
		 * merge with it and move up one order.
		 */
		if (page_is_guard(buddy)) {
			clear_page_guard_flag(buddy);
			set_page_private(page, 0);
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			__mod_zone_freepage_state(zone, 1 << order,
						  migratetype);
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		} else {
			list_del(&buddy->lru);
			zone->free_area[order].nr_free--;
			rmv_page_order(buddy);
		}
568
		combined_idx = buddy_idx & page_idx;
L
Linus Torvalds 已提交
569 570 571 572 573
		page = page + (combined_idx - page_idx);
		page_idx = combined_idx;
		order++;
	}
	set_page_order(page, order);
574 575 576 577 578 579 580 581 582

	/*
	 * If this is not the largest possible page, check if the buddy
	 * of the next-highest order is free. If it is, it's possible
	 * that pages are being freed that will coalesce soon. In case,
	 * that is happening, add the free page to the tail of the list
	 * so it's less likely to be used soon and more likely to be merged
	 * as a higher order page
	 */
583
	if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
584
		struct page *higher_page, *higher_buddy;
585 586 587
		combined_idx = buddy_idx & page_idx;
		higher_page = page + (combined_idx - page_idx);
		buddy_idx = __find_buddy_index(combined_idx, order + 1);
588
		higher_buddy = higher_page + (buddy_idx - combined_idx);
589 590 591 592 593 594 595 596 597
		if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
			list_add_tail(&page->lru,
				&zone->free_area[order].free_list[migratetype]);
			goto out;
		}
	}

	list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
out:
L
Linus Torvalds 已提交
598 599 600
	zone->free_area[order].nr_free++;
}

N
Nick Piggin 已提交
601
static inline int free_pages_check(struct page *page)
L
Linus Torvalds 已提交
602
{
N
Nick Piggin 已提交
603 604
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
605
		(atomic_read(&page->_count) != 0) |
606 607
		(page->flags & PAGE_FLAGS_CHECK_AT_FREE) |
		(mem_cgroup_bad_page_check(page)))) {
N
Nick Piggin 已提交
608
		bad_page(page);
609
		return 1;
610
	}
611 612 613
	if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
		page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
	return 0;
L
Linus Torvalds 已提交
614 615 616
}

/*
617
 * Frees a number of pages from the PCP lists
L
Linus Torvalds 已提交
618
 * Assumes all pages on list are in same zone, and of same order.
619
 * count is the number of pages to free.
L
Linus Torvalds 已提交
620 621 622 623 624 625 626
 *
 * 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.
 */
627 628
static void free_pcppages_bulk(struct zone *zone, int count,
					struct per_cpu_pages *pcp)
L
Linus Torvalds 已提交
629
{
630
	int migratetype = 0;
631
	int batch_free = 0;
632
	int to_free = count;
633

N
Nick Piggin 已提交
634
	spin_lock(&zone->lock);
635
	zone->all_unreclaimable = 0;
L
Linus Torvalds 已提交
636
	zone->pages_scanned = 0;
637

638
	while (to_free) {
N
Nick Piggin 已提交
639
		struct page *page;
640 641 642
		struct list_head *list;

		/*
643 644 645 646 647
		 * Remove pages from lists in a round-robin fashion. A
		 * batch_free count is maintained that is incremented when an
		 * empty list is encountered.  This is so more pages are freed
		 * off fuller lists instead of spinning excessively around empty
		 * lists
648 649
		 */
		do {
650
			batch_free++;
651 652 653 654
			if (++migratetype == MIGRATE_PCPTYPES)
				migratetype = 0;
			list = &pcp->lists[migratetype];
		} while (list_empty(list));
N
Nick Piggin 已提交
655

656 657 658 659
		/* This is the only non-empty list. Free them all. */
		if (batch_free == MIGRATE_PCPTYPES)
			batch_free = to_free;

660
		do {
661 662
			int mt;	/* migratetype of the to-be-freed page */

663 664 665
			page = list_entry(list->prev, struct page, lru);
			/* must delete as __free_one_page list manipulates */
			list_del(&page->lru);
666
			mt = get_freepage_migratetype(page);
667
			/* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
668 669
			__free_one_page(page, zone, 0, mt);
			trace_mm_page_pcpu_drain(page, 0, mt);
670 671
			if (is_migrate_cma(mt))
				__mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1);
672
		} while (--to_free && --batch_free && !list_empty(list));
L
Linus Torvalds 已提交
673
	}
674
	__mod_zone_page_state(zone, NR_FREE_PAGES, count);
N
Nick Piggin 已提交
675
	spin_unlock(&zone->lock);
L
Linus Torvalds 已提交
676 677
}

678 679
static void free_one_page(struct zone *zone, struct page *page, int order,
				int migratetype)
L
Linus Torvalds 已提交
680
{
681
	spin_lock(&zone->lock);
682
	zone->all_unreclaimable = 0;
683
	zone->pages_scanned = 0;
684

685
	__free_one_page(page, zone, order, migratetype);
686
	if (unlikely(migratetype != MIGRATE_ISOLATE))
687
		__mod_zone_freepage_state(zone, 1 << order, migratetype);
688
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
689 690
}

691
static bool free_pages_prepare(struct page *page, unsigned int order)
N
Nick Piggin 已提交
692
{
L
Linus Torvalds 已提交
693
	int i;
694
	int bad = 0;
L
Linus Torvalds 已提交
695

696
	trace_mm_page_free(page, order);
697 698
	kmemcheck_free_shadow(page, order);

A
Andrea Arcangeli 已提交
699 700 701 702
	if (PageAnon(page))
		page->mapping = NULL;
	for (i = 0; i < (1 << order); i++)
		bad += free_pages_check(page + i);
703
	if (bad)
704
		return false;
705

706
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
707
		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
708 709 710
		debug_check_no_obj_freed(page_address(page),
					   PAGE_SIZE << order);
	}
N
Nick Piggin 已提交
711
	arch_free_page(page, order);
N
Nick Piggin 已提交
712
	kernel_map_pages(page, 1 << order, 0);
N
Nick Piggin 已提交
713

714 715 716 717 718 719
	return true;
}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
M
Minchan Kim 已提交
720
	int migratetype;
721 722 723 724

	if (!free_pages_prepare(page, order))
		return;

N
Nick Piggin 已提交
725
	local_irq_save(flags);
726
	__count_vm_events(PGFREE, 1 << order);
M
Minchan Kim 已提交
727 728 729
	migratetype = get_pageblock_migratetype(page);
	set_freepage_migratetype(page, migratetype);
	free_one_page(page_zone(page), page, order, migratetype);
N
Nick Piggin 已提交
730
	local_irq_restore(flags);
L
Linus Torvalds 已提交
731 732
}

733
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
734
{
735 736
	unsigned int nr_pages = 1 << order;
	unsigned int loop;
737

738 739 740 741 742 743 744 745
	prefetchw(page);
	for (loop = 0; loop < nr_pages; loop++) {
		struct page *p = &page[loop];

		if (loop + 1 < nr_pages)
			prefetchw(p + 1);
		__ClearPageReserved(p);
		set_page_count(p, 0);
746
	}
747 748 749

	set_page_refcounted(page);
	__free_pages(page, order);
750 751
}

752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769
#ifdef CONFIG_CMA
/* Free whole pageblock and set it's migration type to MIGRATE_CMA. */
void __init init_cma_reserved_pageblock(struct page *page)
{
	unsigned i = pageblock_nr_pages;
	struct page *p = page;

	do {
		__ClearPageReserved(p);
		set_page_count(p, 0);
	} while (++p, --i);

	set_page_refcounted(page);
	set_pageblock_migratetype(page, MIGRATE_CMA);
	__free_pages(page, pageblock_order);
	totalram_pages += pageblock_nr_pages;
}
#endif
L
Linus Torvalds 已提交
770 771 772 773 774 775 776 777 778 779 780 781 782 783 784

/*
 * The order of subdivision here is critical for the IO subsystem.
 * Please do not alter this order without good reasons and regression
 * testing. Specifically, as large blocks of memory are subdivided,
 * the order in which smaller blocks are delivered depends on the order
 * they're subdivided in this function. This is the primary factor
 * influencing the order in which pages are delivered to the IO
 * subsystem according to empirical testing, and this is also justified
 * by considering the behavior of a buddy system containing a single
 * large block of memory acted on by a series of small allocations.
 * This behavior is a critical factor in sglist merging's success.
 *
 * -- wli
 */
N
Nick Piggin 已提交
785
static inline void expand(struct zone *zone, struct page *page,
786 787
	int low, int high, struct free_area *area,
	int migratetype)
L
Linus Torvalds 已提交
788 789 790 791 792 793 794
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
795
		VM_BUG_ON(bad_range(zone, &page[size]));
796 797 798 799 800 801 802 803 804 805 806 807 808

#ifdef CONFIG_DEBUG_PAGEALLOC
		if (high < debug_guardpage_minorder()) {
			/*
			 * Mark as guard pages (or page), that will allow to
			 * merge back to allocator when buddy will be freed.
			 * Corresponding page table entries will not be touched,
			 * pages will stay not present in virtual address space
			 */
			INIT_LIST_HEAD(&page[size].lru);
			set_page_guard_flag(&page[size]);
			set_page_private(&page[size], high);
			/* Guard pages are not available for any usage */
809 810
			__mod_zone_freepage_state(zone, -(1 << high),
						  migratetype);
811 812 813
			continue;
		}
#endif
814
		list_add(&page[size].lru, &area->free_list[migratetype]);
L
Linus Torvalds 已提交
815 816 817 818 819 820 821 822
		area->nr_free++;
		set_page_order(&page[size], high);
	}
}

/*
 * This page is about to be returned from the page allocator
 */
823
static inline int check_new_page(struct page *page)
L
Linus Torvalds 已提交
824
{
N
Nick Piggin 已提交
825 826
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
827
		(atomic_read(&page->_count) != 0)  |
828 829
		(page->flags & PAGE_FLAGS_CHECK_AT_PREP) |
		(mem_cgroup_bad_page_check(page)))) {
N
Nick Piggin 已提交
830
		bad_page(page);
831
		return 1;
832
	}
833 834 835 836 837 838 839 840 841 842 843 844
	return 0;
}

static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
{
	int i;

	for (i = 0; i < (1 << order); i++) {
		struct page *p = page + i;
		if (unlikely(check_new_page(p)))
			return 1;
	}
845

H
Hugh Dickins 已提交
846
	set_page_private(page, 0);
847
	set_page_refcounted(page);
N
Nick Piggin 已提交
848 849

	arch_alloc_page(page, order);
L
Linus Torvalds 已提交
850
	kernel_map_pages(page, 1 << order, 1);
N
Nick Piggin 已提交
851 852 853 854 855 856 857

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

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

858
	return 0;
L
Linus Torvalds 已提交
859 860
}

861 862 863 864
/*
 * Go through the free lists for the given migratetype and remove
 * the smallest available page from the freelists
 */
865 866
static inline
struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891
						int migratetype)
{
	unsigned int current_order;
	struct free_area * area;
	struct page *page;

	/* Find a page of the appropriate size in the preferred list */
	for (current_order = order; current_order < MAX_ORDER; ++current_order) {
		area = &(zone->free_area[current_order]);
		if (list_empty(&area->free_list[migratetype]))
			continue;

		page = list_entry(area->free_list[migratetype].next,
							struct page, lru);
		list_del(&page->lru);
		rmv_page_order(page);
		area->nr_free--;
		expand(zone, page, order, current_order, area, migratetype);
		return page;
	}

	return NULL;
}


892 893 894 895
/*
 * This array describes the order lists are fallen back to when
 * the free lists for the desirable migrate type are depleted
 */
896 897 898 899 900 901 902 903 904
static int fallbacks[MIGRATE_TYPES][4] = {
	[MIGRATE_UNMOVABLE]   = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE,     MIGRATE_RESERVE },
	[MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE,   MIGRATE_MOVABLE,     MIGRATE_RESERVE },
#ifdef CONFIG_CMA
	[MIGRATE_MOVABLE]     = { MIGRATE_CMA,         MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
	[MIGRATE_CMA]         = { MIGRATE_RESERVE }, /* Never used */
#else
	[MIGRATE_MOVABLE]     = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE,   MIGRATE_RESERVE },
#endif
905 906
	[MIGRATE_RESERVE]     = { MIGRATE_RESERVE }, /* Never used */
	[MIGRATE_ISOLATE]     = { MIGRATE_RESERVE }, /* Never used */
907 908
};

909 910
/*
 * Move the free pages in a range to the free lists of the requested type.
911
 * Note that start_page and end_pages are not aligned on a pageblock
912 913
 * boundary. If alignment is required, use move_freepages_block()
 */
914
int move_freepages(struct zone *zone,
A
Adrian Bunk 已提交
915 916
			  struct page *start_page, struct page *end_page,
			  int migratetype)
917 918 919
{
	struct page *page;
	unsigned long order;
920
	int pages_moved = 0;
921 922 923 924 925 926 927

#ifndef CONFIG_HOLES_IN_ZONE
	/*
	 * page_zone is not safe to call in this context when
	 * CONFIG_HOLES_IN_ZONE is set. This bug check is probably redundant
	 * anyway as we check zone boundaries in move_freepages_block().
	 * Remove at a later date when no bug reports exist related to
M
Mel Gorman 已提交
928
	 * grouping pages by mobility
929 930 931 932 933
	 */
	BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif

	for (page = start_page; page <= end_page;) {
934 935 936
		/* Make sure we are not inadvertently changing nodes */
		VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));

937 938 939 940 941 942 943 944 945 946 947
		if (!pfn_valid_within(page_to_pfn(page))) {
			page++;
			continue;
		}

		if (!PageBuddy(page)) {
			page++;
			continue;
		}

		order = page_order(page);
948 949
		list_move(&page->lru,
			  &zone->free_area[order].free_list[migratetype]);
M
Minchan Kim 已提交
950
		set_freepage_migratetype(page, migratetype);
951
		page += 1 << order;
952
		pages_moved += 1 << order;
953 954
	}

955
	return pages_moved;
956 957
}

958
int move_freepages_block(struct zone *zone, struct page *page,
959
				int migratetype)
960 961 962 963 964
{
	unsigned long start_pfn, end_pfn;
	struct page *start_page, *end_page;

	start_pfn = page_to_pfn(page);
965
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
966
	start_page = pfn_to_page(start_pfn);
967 968
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
969 970 971 972 973 974 975 976 977 978

	/* 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);
}

979 980 981 982 983 984 985 986 987 988 989
static void change_pageblock_range(struct page *pageblock_page,
					int start_order, int migratetype)
{
	int nr_pageblocks = 1 << (start_order - pageblock_order);

	while (nr_pageblocks--) {
		set_pageblock_migratetype(pageblock_page, migratetype);
		pageblock_page += pageblock_nr_pages;
	}
}

990
/* Remove an element from the buddy allocator from the fallback list */
991 992
static inline struct page *
__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
993 994 995 996 997 998 999 1000 1001
{
	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) {
1002
		for (i = 0;; i++) {
1003 1004
			migratetype = fallbacks[start_migratetype][i];

1005 1006
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
1007
				break;
M
Mel Gorman 已提交
1008

1009 1010 1011 1012 1013 1014 1015 1016 1017
			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--;

			/*
1018
			 * If breaking a large block of pages, move all free
1019 1020
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
L
Lucas De Marchi 已提交
1021
			 * aggressive about taking ownership of free pages
1022 1023 1024 1025 1026 1027
			 *
			 * On the other hand, never change migration
			 * type of MIGRATE_CMA pageblocks nor move CMA
			 * pages on different free lists. We don't
			 * want unmovable pages to be allocated from
			 * MIGRATE_CMA areas.
1028
			 */
1029 1030 1031 1032 1033
			if (!is_migrate_cma(migratetype) &&
			    (unlikely(current_order >= pageblock_order / 2) ||
			     start_migratetype == MIGRATE_RECLAIMABLE ||
			     page_group_by_mobility_disabled)) {
				int pages;
1034 1035 1036 1037
				pages = move_freepages_block(zone, page,
								start_migratetype);

				/* Claim the whole block if over half of it is free */
1038 1039
				if (pages >= (1 << (pageblock_order-1)) ||
						page_group_by_mobility_disabled)
1040 1041 1042
					set_pageblock_migratetype(page,
								start_migratetype);

1043
				migratetype = start_migratetype;
1044
			}
1045 1046 1047 1048 1049

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

1050
			/* Take ownership for orders >= pageblock_order */
1051 1052
			if (current_order >= pageblock_order &&
			    !is_migrate_cma(migratetype))
1053
				change_pageblock_range(page, current_order,
1054 1055
							start_migratetype);

1056 1057 1058
			expand(zone, page, order, current_order, area,
			       is_migrate_cma(migratetype)
			     ? migratetype : start_migratetype);
1059 1060 1061 1062

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

1063 1064 1065 1066
			return page;
		}
	}

1067
	return NULL;
1068 1069
}

1070
/*
L
Linus Torvalds 已提交
1071 1072 1073
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
1074 1075
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
L
Linus Torvalds 已提交
1076 1077 1078
{
	struct page *page;

1079
retry_reserve:
1080
	page = __rmqueue_smallest(zone, order, migratetype);
1081

1082
	if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1083
		page = __rmqueue_fallback(zone, order, migratetype);
1084

1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095
		/*
		 * Use MIGRATE_RESERVE rather than fail an allocation. goto
		 * is used because __rmqueue_smallest is an inline function
		 * and we want just one call site
		 */
		if (!page) {
			migratetype = MIGRATE_RESERVE;
			goto retry_reserve;
		}
	}

1096
	trace_mm_page_alloc_zone_locked(page, order, migratetype);
1097
	return page;
L
Linus Torvalds 已提交
1098 1099
}

1100
/*
L
Linus Torvalds 已提交
1101 1102 1103 1104
 * 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.
 */
1105
static int rmqueue_bulk(struct zone *zone, unsigned int order,
1106
			unsigned long count, struct list_head *list,
1107
			int migratetype, int cold)
L
Linus Torvalds 已提交
1108
{
1109
	int mt = migratetype, i;
1110

N
Nick Piggin 已提交
1111
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
1112
	for (i = 0; i < count; ++i) {
1113
		struct page *page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1114
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
1115
			break;
1116 1117 1118 1119 1120 1121 1122 1123 1124 1125

		/*
		 * 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.
		 */
1126 1127 1128 1129
		if (likely(cold == 0))
			list_add(&page->lru, list);
		else
			list_add_tail(&page->lru, list);
1130 1131 1132 1133 1134
		if (IS_ENABLED(CONFIG_CMA)) {
			mt = get_pageblock_migratetype(page);
			if (!is_migrate_cma(mt) && mt != MIGRATE_ISOLATE)
				mt = migratetype;
		}
1135
		set_freepage_migratetype(page, mt);
1136
		list = &page->lru;
1137 1138 1139
		if (is_migrate_cma(mt))
			__mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
					      -(1 << order));
L
Linus Torvalds 已提交
1140
	}
1141
	__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
N
Nick Piggin 已提交
1142
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
1143
	return i;
L
Linus Torvalds 已提交
1144 1145
}

1146
#ifdef CONFIG_NUMA
1147
/*
1148 1149 1150 1151
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
1152 1153
 * Note that this function must be called with the thread pinned to
 * a single processor.
1154
 */
1155
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1156 1157
{
	unsigned long flags;
1158
	int to_drain;
1159

1160 1161 1162 1163 1164
	local_irq_save(flags);
	if (pcp->count >= pcp->batch)
		to_drain = pcp->batch;
	else
		to_drain = pcp->count;
1165 1166 1167 1168
	if (to_drain > 0) {
		free_pcppages_bulk(zone, to_drain, pcp);
		pcp->count -= to_drain;
	}
1169
	local_irq_restore(flags);
1170 1171 1172
}
#endif

1173 1174 1175 1176 1177 1178 1179 1180
/*
 * Drain pages of the indicated processor.
 *
 * The processor must either be the current processor and the
 * thread pinned to the current processor or a processor that
 * is not online.
 */
static void drain_pages(unsigned int cpu)
L
Linus Torvalds 已提交
1181
{
N
Nick Piggin 已提交
1182
	unsigned long flags;
L
Linus Torvalds 已提交
1183 1184
	struct zone *zone;

1185
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
1186
		struct per_cpu_pageset *pset;
1187
		struct per_cpu_pages *pcp;
L
Linus Torvalds 已提交
1188

1189 1190
		local_irq_save(flags);
		pset = per_cpu_ptr(zone->pageset, cpu);
1191 1192

		pcp = &pset->pcp;
1193 1194 1195 1196
		if (pcp->count) {
			free_pcppages_bulk(zone, pcp->count, pcp);
			pcp->count = 0;
		}
1197
		local_irq_restore(flags);
L
Linus Torvalds 已提交
1198 1199 1200
	}
}

1201 1202 1203 1204 1205 1206 1207 1208 1209
/*
 * 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());
}

/*
1210 1211 1212 1213 1214 1215 1216
 * Spill all the per-cpu pages from all CPUs back into the buddy allocator.
 *
 * Note that this code is protected against sending an IPI to an offline
 * CPU but does not guarantee sending an IPI to newly hotplugged CPUs:
 * on_each_cpu_mask() blocks hotplug and won't talk to offlined CPUs but
 * nothing keeps CPUs from showing up after we populated the cpumask and
 * before the call to on_each_cpu_mask().
1217 1218 1219
 */
void drain_all_pages(void)
{
1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250
	int cpu;
	struct per_cpu_pageset *pcp;
	struct zone *zone;

	/*
	 * Allocate in the BSS so we wont require allocation in
	 * direct reclaim path for CONFIG_CPUMASK_OFFSTACK=y
	 */
	static cpumask_t cpus_with_pcps;

	/*
	 * We don't care about racing with CPU hotplug event
	 * as offline notification will cause the notified
	 * cpu to drain that CPU pcps and on_each_cpu_mask
	 * disables preemption as part of its processing
	 */
	for_each_online_cpu(cpu) {
		bool has_pcps = false;
		for_each_populated_zone(zone) {
			pcp = per_cpu_ptr(zone->pageset, cpu);
			if (pcp->pcp.count) {
				has_pcps = true;
				break;
			}
		}
		if (has_pcps)
			cpumask_set_cpu(cpu, &cpus_with_pcps);
		else
			cpumask_clear_cpu(cpu, &cpus_with_pcps);
	}
	on_each_cpu_mask(&cpus_with_pcps, drain_local_pages, NULL, 1);
1251 1252
}

1253
#ifdef CONFIG_HIBERNATION
L
Linus Torvalds 已提交
1254 1255 1256

void mark_free_pages(struct zone *zone)
{
1257 1258
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
1259
	int order, t;
L
Linus Torvalds 已提交
1260 1261 1262 1263 1264 1265
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
1266 1267 1268 1269 1270 1271

	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);

1272 1273
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
1274
		}
L
Linus Torvalds 已提交
1275

1276 1277
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
1278
			unsigned long i;
L
Linus Torvalds 已提交
1279

1280 1281
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
1282
				swsusp_set_page_free(pfn_to_page(pfn + i));
1283
		}
1284
	}
L
Linus Torvalds 已提交
1285 1286
	spin_unlock_irqrestore(&zone->lock, flags);
}
1287
#endif /* CONFIG_PM */
L
Linus Torvalds 已提交
1288 1289 1290

/*
 * Free a 0-order page
L
Li Hong 已提交
1291
 * cold == 1 ? free a cold page : free a hot page
L
Linus Torvalds 已提交
1292
 */
L
Li Hong 已提交
1293
void free_hot_cold_page(struct page *page, int cold)
L
Linus Torvalds 已提交
1294 1295 1296 1297
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;
1298
	int migratetype;
L
Linus Torvalds 已提交
1299

1300
	if (!free_pages_prepare(page, 0))
1301 1302
		return;

1303
	migratetype = get_pageblock_migratetype(page);
1304
	set_freepage_migratetype(page, migratetype);
L
Linus Torvalds 已提交
1305
	local_irq_save(flags);
1306
	__count_vm_event(PGFREE);
1307

1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322
	/*
	 * We only track unmovable, reclaimable and movable on pcp lists.
	 * Free ISOLATE pages back to the allocator because they are being
	 * offlined but treat RESERVE as movable pages so we can get those
	 * areas back if necessary. Otherwise, we may have to free
	 * excessively into the page allocator
	 */
	if (migratetype >= MIGRATE_PCPTYPES) {
		if (unlikely(migratetype == MIGRATE_ISOLATE)) {
			free_one_page(zone, page, 0, migratetype);
			goto out;
		}
		migratetype = MIGRATE_MOVABLE;
	}

1323
	pcp = &this_cpu_ptr(zone->pageset)->pcp;
1324
	if (cold)
1325
		list_add_tail(&page->lru, &pcp->lists[migratetype]);
1326
	else
1327
		list_add(&page->lru, &pcp->lists[migratetype]);
L
Linus Torvalds 已提交
1328
	pcp->count++;
N
Nick Piggin 已提交
1329
	if (pcp->count >= pcp->high) {
1330
		free_pcppages_bulk(zone, pcp->batch, pcp);
N
Nick Piggin 已提交
1331 1332
		pcp->count -= pcp->batch;
	}
1333 1334

out:
L
Linus Torvalds 已提交
1335 1336 1337
	local_irq_restore(flags);
}

1338 1339 1340 1341 1342 1343 1344 1345
/*
 * Free a list of 0-order pages
 */
void free_hot_cold_page_list(struct list_head *list, int cold)
{
	struct page *page, *next;

	list_for_each_entry_safe(page, next, list, lru) {
1346
		trace_mm_page_free_batched(page, cold);
1347 1348 1349 1350
		free_hot_cold_page(page, cold);
	}
}

N
Nick Piggin 已提交
1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362
/*
 * split_page takes a non-compound higher-order page, and splits it into
 * n (1<<order) sub-pages: page[0..n]
 * Each sub-page must be freed individually.
 *
 * Note: this is probably too low level an operation for use in drivers.
 * Please consult with lkml before using this in your driver.
 */
void split_page(struct page *page, unsigned int order)
{
	int i;

N
Nick Piggin 已提交
1363 1364
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1365 1366 1367 1368 1369 1370 1371 1372 1373 1374

#ifdef CONFIG_KMEMCHECK
	/*
	 * Split shadow pages too, because free(page[0]) would
	 * otherwise free the whole shadow.
	 */
	if (kmemcheck_page_is_tracked(page))
		split_page(virt_to_page(page[0].shadow), order);
#endif

1375 1376
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
1377 1378
}

1379
/*
1380 1381 1382
 * Similar to the split_page family of functions except that the page
 * required at the given order and being isolated now to prevent races
 * with parallel allocators
1383
 */
1384
int capture_free_page(struct page *page, int alloc_order, int migratetype)
1385 1386 1387 1388
{
	unsigned int order;
	unsigned long watermark;
	struct zone *zone;
1389
	int mt;
1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404

	BUG_ON(!PageBuddy(page));

	zone = page_zone(page);
	order = page_order(page);

	/* Obey watermarks as if the page was being allocated */
	watermark = low_wmark_pages(zone) + (1 << order);
	if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
		return 0;

	/* Remove page from free list */
	list_del(&page->lru);
	zone->free_area[order].nr_free--;
	rmv_page_order(page);
1405 1406 1407

	mt = get_pageblock_migratetype(page);
	if (unlikely(mt != MIGRATE_ISOLATE))
1408
		__mod_zone_freepage_state(zone, -(1UL << alloc_order), mt);
1409

1410 1411 1412
	if (alloc_order != order)
		expand(zone, page, alloc_order, order,
			&zone->free_area[order], migratetype);
1413

1414
	/* Set the pageblock if the captured page is at least a pageblock */
1415 1416
	if (order >= pageblock_order - 1) {
		struct page *endpage = page + (1 << order) - 1;
1417 1418 1419 1420 1421 1422
		for (; page < endpage; page += pageblock_nr_pages) {
			int mt = get_pageblock_migratetype(page);
			if (mt != MIGRATE_ISOLATE && !is_migrate_cma(mt))
				set_pageblock_migratetype(page,
							  MIGRATE_MOVABLE);
		}
1423 1424
	}

1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453
	return 1UL << order;
}

/*
 * Similar to split_page except the page is already free. As this is only
 * being used for migration, the migratetype of the block also changes.
 * As this is called with interrupts disabled, the caller is responsible
 * for calling arch_alloc_page() and kernel_map_page() after interrupts
 * are enabled.
 *
 * Note: this is probably too low level an operation for use in drivers.
 * Please consult with lkml before using this in your driver.
 */
int split_free_page(struct page *page)
{
	unsigned int order;
	int nr_pages;

	BUG_ON(!PageBuddy(page));
	order = page_order(page);

	nr_pages = capture_free_page(page, order, 0);
	if (!nr_pages)
		return 0;

	/* Split into individual pages */
	set_page_refcounted(page);
	split_page(page, order);
	return nr_pages;
1454 1455
}

L
Linus Torvalds 已提交
1456 1457 1458 1459 1460
/*
 * 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.
 */
1461 1462
static inline
struct page *buffered_rmqueue(struct zone *preferred_zone,
1463 1464
			struct zone *zone, int order, gfp_t gfp_flags,
			int migratetype)
L
Linus Torvalds 已提交
1465 1466
{
	unsigned long flags;
1467
	struct page *page;
L
Linus Torvalds 已提交
1468 1469
	int cold = !!(gfp_flags & __GFP_COLD);

1470
again:
N
Nick Piggin 已提交
1471
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1472
		struct per_cpu_pages *pcp;
1473
		struct list_head *list;
L
Linus Torvalds 已提交
1474 1475

		local_irq_save(flags);
1476 1477
		pcp = &this_cpu_ptr(zone->pageset)->pcp;
		list = &pcp->lists[migratetype];
1478
		if (list_empty(list)) {
1479
			pcp->count += rmqueue_bulk(zone, 0,
1480
					pcp->batch, list,
1481
					migratetype, cold);
1482
			if (unlikely(list_empty(list)))
1483
				goto failed;
1484
		}
1485

1486 1487 1488 1489 1490
		if (cold)
			page = list_entry(list->prev, struct page, lru);
		else
			page = list_entry(list->next, struct page, lru);

1491 1492
		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1493
	} else {
1494 1495 1496 1497 1498 1499 1500 1501
		if (unlikely(gfp_flags & __GFP_NOFAIL)) {
			/*
			 * __GFP_NOFAIL is not to be used in new code.
			 *
			 * All __GFP_NOFAIL callers should be fixed so that they
			 * properly detect and handle allocation failures.
			 *
			 * We most definitely don't want callers attempting to
1502
			 * allocate greater than order-1 page units with
1503 1504
			 * __GFP_NOFAIL.
			 */
1505
			WARN_ON_ONCE(order > 1);
1506
		}
L
Linus Torvalds 已提交
1507
		spin_lock_irqsave(&zone->lock, flags);
1508
		page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1509 1510 1511
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
1512 1513
		__mod_zone_freepage_state(zone, -(1 << order),
					  get_pageblock_migratetype(page));
L
Linus Torvalds 已提交
1514 1515
	}

1516
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
A
Andi Kleen 已提交
1517
	zone_statistics(preferred_zone, zone, gfp_flags);
N
Nick Piggin 已提交
1518
	local_irq_restore(flags);
L
Linus Torvalds 已提交
1519

N
Nick Piggin 已提交
1520
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1521
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1522
		goto again;
L
Linus Torvalds 已提交
1523
	return page;
N
Nick Piggin 已提交
1524 1525 1526 1527

failed:
	local_irq_restore(flags);
	return NULL;
L
Linus Torvalds 已提交
1528 1529
}

1530 1531
#ifdef CONFIG_FAIL_PAGE_ALLOC

1532
static struct {
1533 1534 1535 1536
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1537
	u32 min_order;
1538 1539
} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1540 1541
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1542
	.min_order = 1,
1543 1544 1545 1546 1547 1548 1549 1550
};

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);

1551
static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1552
{
1553
	if (order < fail_page_alloc.min_order)
1554
		return false;
1555
	if (gfp_mask & __GFP_NOFAIL)
1556
		return false;
1557
	if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1558
		return false;
1559
	if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1560
		return false;
1561 1562 1563 1564 1565 1566 1567 1568

	return should_fail(&fail_page_alloc.attr, 1 << order);
}

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

static int __init fail_page_alloc_debugfs(void)
{
A
Al Viro 已提交
1569
	umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1570 1571
	struct dentry *dir;

1572 1573 1574 1575
	dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
					&fail_page_alloc.attr);
	if (IS_ERR(dir))
		return PTR_ERR(dir);
1576

1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588
	if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
				&fail_page_alloc.ignore_gfp_wait))
		goto fail;
	if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
				&fail_page_alloc.ignore_gfp_highmem))
		goto fail;
	if (!debugfs_create_u32("min-order", mode, dir,
				&fail_page_alloc.min_order))
		goto fail;

	return 0;
fail:
1589
	debugfs_remove_recursive(dir);
1590

1591
	return -ENOMEM;
1592 1593 1594 1595 1596 1597 1598 1599
}

late_initcall(fail_page_alloc_debugfs);

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

#else /* CONFIG_FAIL_PAGE_ALLOC */

1600
static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1601
{
1602
	return false;
1603 1604 1605 1606
}

#endif /* CONFIG_FAIL_PAGE_ALLOC */

L
Linus Torvalds 已提交
1607
/*
1608
 * Return true if free pages are above 'mark'. This takes into account the order
L
Linus Torvalds 已提交
1609 1610
 * of the allocation.
 */
1611 1612
static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
		      int classzone_idx, int alloc_flags, long free_pages)
L
Linus Torvalds 已提交
1613 1614
{
	/* free_pages my go negative - that's OK */
1615
	long min = mark;
1616
	long lowmem_reserve = z->lowmem_reserve[classzone_idx];
L
Linus Torvalds 已提交
1617 1618
	int o;

1619
	free_pages -= (1 << order) - 1;
R
Rohit Seth 已提交
1620
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1621
		min -= min / 2;
R
Rohit Seth 已提交
1622
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1623
		min -= min / 4;
1624 1625 1626 1627 1628
#ifdef CONFIG_CMA
	/* If allocation can't use CMA areas don't use free CMA pages */
	if (!(alloc_flags & ALLOC_CMA))
		free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
#endif
1629
	if (free_pages <= min + lowmem_reserve)
1630
		return false;
L
Linus Torvalds 已提交
1631 1632 1633 1634 1635 1636 1637 1638
	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)
1639
			return false;
L
Linus Torvalds 已提交
1640
	}
1641 1642 1643
	return true;
}

1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657
#ifdef CONFIG_MEMORY_ISOLATION
static inline unsigned long nr_zone_isolate_freepages(struct zone *zone)
{
	if (unlikely(zone->nr_pageblock_isolate))
		return zone->nr_pageblock_isolate * pageblock_nr_pages;
	return 0;
}
#else
static inline unsigned long nr_zone_isolate_freepages(struct zone *zone)
{
	return 0;
}
#endif

1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672
bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
		      int classzone_idx, int alloc_flags)
{
	return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
					zone_page_state(z, NR_FREE_PAGES));
}

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

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

1673 1674 1675 1676 1677 1678 1679 1680
	/*
	 * If the zone has MIGRATE_ISOLATE type free pages, we should consider
	 * it.  nr_zone_isolate_freepages is never accurate so kswapd might not
	 * sleep although it could do so.  But this is more desirable for memory
	 * hotplug than sleeping which can cause a livelock in the direct
	 * reclaim path.
	 */
	free_pages -= nr_zone_isolate_freepages(z);
1681 1682
	return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
								free_pages);
L
Linus Torvalds 已提交
1683 1684
}

1685 1686 1687 1688 1689 1690
#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
1691
 * that have to skip over a lot of full or unallowed zones.
1692 1693 1694
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1695
 * tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716
 *
 * 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
1717
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1718 1719 1720 1721 1722 1723
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1724
					&node_states[N_HIGH_MEMORY];
1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749
	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.
 */
1750
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1751 1752 1753 1754 1755 1756 1757 1758 1759 1760
						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;

1761
	i = z - zonelist->_zonerefs;
1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772
	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.
 */
1773
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1774 1775 1776 1777 1778 1779 1780 1781
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

1782
	i = z - zonelist->_zonerefs;
1783 1784 1785 1786

	set_bit(i, zlc->fullzones);
}

1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801
/*
 * clear all zones full, called after direct reclaim makes progress so that
 * a zone that was recently full is not skipped over for up to a second
 */
static void zlc_clear_zones_full(struct zonelist *zonelist)
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */

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

	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
}

1802 1803 1804 1805 1806 1807 1808 1809 1810 1811
static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
{
	return node_isset(local_zone->node, zone->zone_pgdat->reclaim_nodes);
}

static void __paginginit init_zone_allows_reclaim(int nid)
{
	int i;

	for_each_online_node(i)
1812
		if (node_distance(nid, i) <= RECLAIM_DISTANCE)
1813
			node_set(i, NODE_DATA(nid)->reclaim_nodes);
1814
		else
1815 1816 1817
			zone_reclaim_mode = 1;
}

1818 1819 1820 1821 1822 1823 1824
#else	/* CONFIG_NUMA */

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

1825
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1826 1827 1828 1829 1830
				nodemask_t *allowednodes)
{
	return 1;
}

1831
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1832 1833
{
}
1834 1835 1836 1837

static void zlc_clear_zones_full(struct zonelist *zonelist)
{
}
1838 1839 1840 1841 1842 1843 1844 1845 1846

static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
{
	return true;
}

static inline void init_zone_allows_reclaim(int nid)
{
}
1847 1848
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1849
/*
1850
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1851 1852 1853
 * a page.
 */
static struct page *
1854
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1855
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1856
		struct zone *preferred_zone, int migratetype)
M
Martin Hicks 已提交
1857
{
1858
	struct zoneref *z;
R
Rohit Seth 已提交
1859
	struct page *page = NULL;
1860
	int classzone_idx;
1861
	struct zone *zone;
1862 1863 1864
	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 */
1865

1866
	classzone_idx = zone_idx(preferred_zone);
1867
zonelist_scan:
R
Rohit Seth 已提交
1868
	/*
1869
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1870 1871
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1872 1873
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1874 1875 1876
		if (NUMA_BUILD && zlc_active &&
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1877
		if ((alloc_flags & ALLOC_CPUSET) &&
1878
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1879
				continue;
1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908
		/*
		 * When allocating a page cache page for writing, we
		 * want to get it from a zone that is within its dirty
		 * limit, such that no single zone holds more than its
		 * proportional share of globally allowed dirty pages.
		 * The dirty limits take into account the zone's
		 * lowmem reserves and high watermark so that kswapd
		 * should be able to balance it without having to
		 * write pages from its LRU list.
		 *
		 * This may look like it could increase pressure on
		 * lower zones by failing allocations in higher zones
		 * before they are full.  But the pages that do spill
		 * over are limited as the lower zones are protected
		 * by this very same mechanism.  It should not become
		 * a practical burden to them.
		 *
		 * XXX: For now, allow allocations to potentially
		 * exceed the per-zone dirty limit in the slowpath
		 * (ALLOC_WMARK_LOW unset) before going into reclaim,
		 * which is important when on a NUMA setup the allowed
		 * zones are together not big enough to reach the
		 * global limit.  The proper fix for these situations
		 * will require awareness of zones in the
		 * dirty-throttling and the flusher threads.
		 */
		if ((alloc_flags & ALLOC_WMARK_LOW) &&
		    (gfp_mask & __GFP_WRITE) && !zone_dirty_ok(zone))
			goto this_zone_full;
R
Rohit Seth 已提交
1909

1910
		BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
R
Rohit Seth 已提交
1911
		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1912
			unsigned long mark;
1913 1914
			int ret;

1915
			mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1916 1917 1918 1919
			if (zone_watermark_ok(zone, order, mark,
				    classzone_idx, alloc_flags))
				goto try_this_zone;

1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930
			if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
				/*
				 * we do zlc_setup if there are multiple nodes
				 * and before considering the first zone allowed
				 * by the cpuset.
				 */
				allowednodes = zlc_setup(zonelist, alloc_flags);
				zlc_active = 1;
				did_zlc_setup = 1;
			}

1931 1932
			if (zone_reclaim_mode == 0 ||
			    !zone_allows_reclaim(preferred_zone, zone))
1933 1934
				goto this_zone_full;

1935 1936 1937 1938 1939 1940 1941 1942
			/*
			 * As we may have just activated ZLC, check if the first
			 * eligible zone has failed zone_reclaim recently.
			 */
			if (NUMA_BUILD && zlc_active &&
				!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;

1943 1944 1945 1946
			ret = zone_reclaim(zone, gfp_mask, order);
			switch (ret) {
			case ZONE_RECLAIM_NOSCAN:
				/* did not scan */
1947
				continue;
1948 1949
			case ZONE_RECLAIM_FULL:
				/* scanned but unreclaimable */
1950
				continue;
1951 1952 1953 1954
			default:
				/* did we reclaim enough */
				if (!zone_watermark_ok(zone, order, mark,
						classzone_idx, alloc_flags))
1955
					goto this_zone_full;
1956
			}
R
Rohit Seth 已提交
1957 1958
		}

1959
try_this_zone:
1960 1961
		page = buffered_rmqueue(preferred_zone, zone, order,
						gfp_mask, migratetype);
1962
		if (page)
R
Rohit Seth 已提交
1963
			break;
1964 1965 1966
this_zone_full:
		if (NUMA_BUILD)
			zlc_mark_zone_full(zonelist, z);
1967
	}
1968 1969 1970 1971 1972 1973

	if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
		/* Disable zlc cache for second zonelist scan */
		zlc_active = 0;
		goto zonelist_scan;
	}
1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984

	if (page)
		/*
		 * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was
		 * necessary to allocate the page. The expectation is
		 * that the caller is taking steps that will free more
		 * memory. The caller should avoid the page being used
		 * for !PFMEMALLOC purposes.
		 */
		page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS);

R
Rohit Seth 已提交
1985
	return page;
M
Martin Hicks 已提交
1986 1987
}

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001
/*
 * Large machines with many possible nodes should not always dump per-node
 * meminfo in irq context.
 */
static inline bool should_suppress_show_mem(void)
{
	bool ret = false;

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

2002 2003 2004 2005 2006 2007 2008 2009
static DEFINE_RATELIMIT_STATE(nopage_rs,
		DEFAULT_RATELIMIT_INTERVAL,
		DEFAULT_RATELIMIT_BURST);

void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...)
{
	unsigned int filter = SHOW_MEM_FILTER_NODES;

2010 2011
	if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
	    debug_guardpage_minorder() > 0)
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026
		return;

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

	if (fmt) {
J
Joe Perches 已提交
2027 2028 2029
		struct va_format vaf;
		va_list args;

2030
		va_start(args, fmt);
J
Joe Perches 已提交
2031 2032 2033 2034 2035 2036

		vaf.fmt = fmt;
		vaf.va = &args;

		pr_warn("%pV", &vaf);

2037 2038 2039
		va_end(args);
	}

J
Joe Perches 已提交
2040 2041
	pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
		current->comm, order, gfp_mask);
2042 2043 2044 2045 2046 2047

	dump_stack();
	if (!should_suppress_show_mem())
		show_mem(filter);
}

2048 2049
static inline int
should_alloc_retry(gfp_t gfp_mask, unsigned int order,
2050
				unsigned long did_some_progress,
2051
				unsigned long pages_reclaimed)
L
Linus Torvalds 已提交
2052
{
2053 2054 2055
	/* Do not loop if specifically requested */
	if (gfp_mask & __GFP_NORETRY)
		return 0;
L
Linus Torvalds 已提交
2056

2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068
	/* Always retry if specifically requested */
	if (gfp_mask & __GFP_NOFAIL)
		return 1;

	/*
	 * Suspend converts GFP_KERNEL to __GFP_WAIT which can prevent reclaim
	 * making forward progress without invoking OOM. Suspend also disables
	 * storage devices so kswapd will not help. Bail if we are suspending.
	 */
	if (!did_some_progress && pm_suspended_storage())
		return 0;

2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085
	/*
	 * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
	 * means __GFP_NOFAIL, but that may not be true in other
	 * implementations.
	 */
	if (order <= PAGE_ALLOC_COSTLY_ORDER)
		return 1;

	/*
	 * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is
	 * specified, then we retry until we no longer reclaim any pages
	 * (above), or we've reclaimed an order of pages at least as
	 * large as the allocation's order. In both cases, if the
	 * allocation still fails, we stop retrying.
	 */
	if (gfp_mask & __GFP_REPEAT && pages_reclaimed < (1 << order))
		return 1;
2086

2087 2088
	return 0;
}
2089

2090 2091 2092
static inline struct page *
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
2093 2094
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
2095 2096 2097 2098
{
	struct page *page;

	/* Acquire the OOM killer lock for the zones in zonelist */
2099
	if (!try_set_zonelist_oom(zonelist, gfp_mask)) {
2100
		schedule_timeout_uninterruptible(1);
L
Linus Torvalds 已提交
2101 2102
		return NULL;
	}
2103

2104 2105 2106 2107 2108 2109 2110
	/*
	 * Go through the zonelist yet one more time, keep very high watermark
	 * here, this is only to catch a parallel oom killing, we must fail if
	 * we're still under heavy pressure.
	 */
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask,
		order, zonelist, high_zoneidx,
2111
		ALLOC_WMARK_HIGH|ALLOC_CPUSET,
2112
		preferred_zone, migratetype);
R
Rohit Seth 已提交
2113
	if (page)
2114 2115
		goto out;

2116 2117 2118 2119
	if (!(gfp_mask & __GFP_NOFAIL)) {
		/* The OOM killer will not help higher order allocs */
		if (order > PAGE_ALLOC_COSTLY_ORDER)
			goto out;
2120 2121 2122
		/* The OOM killer does not needlessly kill tasks for lowmem */
		if (high_zoneidx < ZONE_NORMAL)
			goto out;
2123 2124 2125 2126 2127 2128 2129 2130 2131 2132
		/*
		 * GFP_THISNODE contains __GFP_NORETRY and we never hit this.
		 * Sanity check for bare calls of __GFP_THISNODE, not real OOM.
		 * The caller should handle page allocation failure by itself if
		 * it specifies __GFP_THISNODE.
		 * Note: Hugepage uses it but will hit PAGE_ALLOC_COSTLY_ORDER.
		 */
		if (gfp_mask & __GFP_THISNODE)
			goto out;
	}
2133
	/* Exhausted what can be done so it's blamo time */
2134
	out_of_memory(zonelist, gfp_mask, order, nodemask, false);
2135 2136 2137 2138 2139 2140

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

2141 2142 2143 2144 2145 2146
#ifdef CONFIG_COMPACTION
/* Try memory compaction for high-order allocations before reclaim */
static struct page *
__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2147
	int migratetype, bool sync_migration,
2148
	bool *contended_compaction, bool *deferred_compaction,
2149
	unsigned long *did_some_progress)
2150
{
2151
	struct page *page = NULL;
2152

2153
	if (!order)
2154 2155
		return NULL;

2156
	if (compaction_deferred(preferred_zone, order)) {
2157 2158 2159 2160
		*deferred_compaction = true;
		return NULL;
	}

2161
	current->flags |= PF_MEMALLOC;
2162
	*did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
2163
						nodemask, sync_migration,
2164
						contended_compaction, &page);
2165
	current->flags &= ~PF_MEMALLOC;
2166

2167 2168 2169 2170 2171 2172 2173
	/* If compaction captured a page, prep and use it */
	if (page) {
		prep_new_page(page, order, gfp_mask);
		goto got_page;
	}

	if (*did_some_progress != COMPACT_SKIPPED) {
2174 2175 2176 2177 2178 2179
		/* Page migration frees to the PCP lists but we want merging */
		drain_pages(get_cpu());
		put_cpu();

		page = get_page_from_freelist(gfp_mask, nodemask,
				order, zonelist, high_zoneidx,
2180 2181
				alloc_flags & ~ALLOC_NO_WATERMARKS,
				preferred_zone, migratetype);
2182
		if (page) {
2183
got_page:
2184
			preferred_zone->compact_blockskip_flush = false;
2185 2186
			preferred_zone->compact_considered = 0;
			preferred_zone->compact_defer_shift = 0;
2187 2188
			if (order >= preferred_zone->compact_order_failed)
				preferred_zone->compact_order_failed = order + 1;
2189 2190 2191 2192 2193 2194 2195 2196 2197 2198
			count_vm_event(COMPACTSUCCESS);
			return page;
		}

		/*
		 * It's bad if compaction run occurs and fails.
		 * The most likely reason is that pages exist,
		 * but not enough to satisfy watermarks.
		 */
		count_vm_event(COMPACTFAIL);
2199 2200 2201 2202 2203 2204

		/*
		 * As async compaction considers a subset of pageblocks, only
		 * defer if the failure was a sync compaction failure.
		 */
		if (sync_migration)
2205
			defer_compaction(preferred_zone, order);
2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216

		cond_resched();
	}

	return NULL;
}
#else
static inline struct page *
__alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
2217
	int migratetype, bool sync_migration,
2218
	bool *contended_compaction, bool *deferred_compaction,
2219
	unsigned long *did_some_progress)
2220 2221 2222 2223 2224
{
	return NULL;
}
#endif /* CONFIG_COMPACTION */

2225 2226 2227 2228
/* Perform direct synchronous page reclaim */
static int
__perform_reclaim(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist,
		  nodemask_t *nodemask)
2229 2230
{
	struct reclaim_state reclaim_state;
2231
	int progress;
2232 2233 2234 2235 2236

	cond_resched();

	/* We now go into synchronous reclaim */
	cpuset_memory_pressure_bump();
2237
	current->flags |= PF_MEMALLOC;
2238 2239
	lockdep_set_current_reclaim_state(gfp_mask);
	reclaim_state.reclaimed_slab = 0;
2240
	current->reclaim_state = &reclaim_state;
2241

2242
	progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
2243

2244
	current->reclaim_state = NULL;
2245
	lockdep_clear_current_reclaim_state();
2246
	current->flags &= ~PF_MEMALLOC;
2247 2248 2249

	cond_resched();

2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264
	return progress;
}

/* The really slow allocator path where we enter direct reclaim */
static inline struct page *
__alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
	nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
	int migratetype, unsigned long *did_some_progress)
{
	struct page *page = NULL;
	bool drained = false;

	*did_some_progress = __perform_reclaim(gfp_mask, order, zonelist,
					       nodemask);
2265 2266
	if (unlikely(!(*did_some_progress)))
		return NULL;
2267

2268 2269 2270 2271
	/* After successful reclaim, reconsider all zones for allocation */
	if (NUMA_BUILD)
		zlc_clear_zones_full(zonelist);

2272 2273
retry:
	page = get_page_from_freelist(gfp_mask, nodemask, order,
2274
					zonelist, high_zoneidx,
2275 2276
					alloc_flags & ~ALLOC_NO_WATERMARKS,
					preferred_zone, migratetype);
2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287

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

2288 2289 2290
	return page;
}

L
Linus Torvalds 已提交
2291
/*
2292 2293
 * This is called in the allocator slow-path if the allocation request is of
 * sufficient urgency to ignore watermarks and take other desperate measures
L
Linus Torvalds 已提交
2294
 */
2295 2296 2297
static inline struct page *
__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
2298 2299
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
2300 2301 2302 2303 2304
{
	struct page *page;

	do {
		page = get_page_from_freelist(gfp_mask, nodemask, order,
2305
			zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
2306
			preferred_zone, migratetype);
2307 2308

		if (!page && gfp_mask & __GFP_NOFAIL)
2309
			wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2310 2311 2312 2313 2314 2315 2316
	} while (!page && (gfp_mask & __GFP_NOFAIL));

	return page;
}

static inline
void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
2317 2318
						enum zone_type high_zoneidx,
						enum zone_type classzone_idx)
L
Linus Torvalds 已提交
2319
{
2320 2321
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
2322

2323
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
2324
		wakeup_kswapd(zone, order, classzone_idx);
2325
}
2326

2327 2328 2329 2330 2331
static inline int
gfp_to_alloc_flags(gfp_t gfp_mask)
{
	int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
	const gfp_t wait = gfp_mask & __GFP_WAIT;
L
Linus Torvalds 已提交
2332

2333
	/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2334
	BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2335

2336 2337 2338 2339 2340 2341
	/*
	 * The caller may dip into page reserves a bit more if the caller
	 * cannot run direct reclaim, or if the caller has realtime scheduling
	 * policy or is asking for __GFP_HIGH memory.  GFP_ATOMIC requests will
	 * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH).
	 */
2342
	alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
L
Linus Torvalds 已提交
2343

2344
	if (!wait) {
2345 2346 2347 2348 2349 2350
		/*
		 * Not worth trying to allocate harder for
		 * __GFP_NOMEMALLOC even if it can't schedule.
		 */
		if  (!(gfp_mask & __GFP_NOMEMALLOC))
			alloc_flags |= ALLOC_HARDER;
2351
		/*
2352 2353
		 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
		 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2354
		 */
2355
		alloc_flags &= ~ALLOC_CPUSET;
2356
	} else if (unlikely(rt_task(current)) && !in_interrupt())
2357 2358
		alloc_flags |= ALLOC_HARDER;

2359 2360 2361
	if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
		if (gfp_mask & __GFP_MEMALLOC)
			alloc_flags |= ALLOC_NO_WATERMARKS;
2362 2363 2364 2365 2366
		else if (in_serving_softirq() && (current->flags & PF_MEMALLOC))
			alloc_flags |= ALLOC_NO_WATERMARKS;
		else if (!in_interrupt() &&
				((current->flags & PF_MEMALLOC) ||
				 unlikely(test_thread_flag(TIF_MEMDIE))))
2367
			alloc_flags |= ALLOC_NO_WATERMARKS;
L
Linus Torvalds 已提交
2368
	}
2369 2370 2371 2372
#ifdef CONFIG_CMA
	if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
		alloc_flags |= ALLOC_CMA;
#endif
2373 2374 2375
	return alloc_flags;
}

2376 2377
bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
{
2378
	return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
2379 2380
}

2381 2382 2383
static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
2384 2385
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
2386 2387 2388 2389 2390 2391
{
	const gfp_t wait = gfp_mask & __GFP_WAIT;
	struct page *page = NULL;
	int alloc_flags;
	unsigned long pages_reclaimed = 0;
	unsigned long did_some_progress;
2392
	bool sync_migration = false;
2393
	bool deferred_compaction = false;
2394
	bool contended_compaction = false;
L
Linus Torvalds 已提交
2395

2396 2397 2398 2399 2400 2401
	/*
	 * In the slowpath, we sanity check order to avoid ever trying to
	 * reclaim >= MAX_ORDER areas which will never succeed. Callers may
	 * be using allocators in order of preference for an area that is
	 * too large.
	 */
2402 2403
	if (order >= MAX_ORDER) {
		WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2404
		return NULL;
2405
	}
L
Linus Torvalds 已提交
2406

2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417
	/*
	 * 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;

2418
restart:
R
Rik van Riel 已提交
2419 2420
	wake_all_kswapd(order, zonelist, high_zoneidx,
					zone_idx(preferred_zone));
L
Linus Torvalds 已提交
2421

2422
	/*
R
Rohit Seth 已提交
2423 2424 2425
	 * 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.
2426
	 */
2427
	alloc_flags = gfp_to_alloc_flags(gfp_mask);
L
Linus Torvalds 已提交
2428

2429 2430 2431 2432 2433 2434 2435 2436
	/*
	 * Find the true preferred zone if the allocation is unconstrained by
	 * cpusets.
	 */
	if (!(alloc_flags & ALLOC_CPUSET) && !nodemask)
		first_zones_zonelist(zonelist, high_zoneidx, NULL,
					&preferred_zone);

2437
rebalance:
2438
	/* This is the last chance, in general, before the goto nopage. */
2439
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
2440 2441
			high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
			preferred_zone, migratetype);
R
Rohit Seth 已提交
2442 2443
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
2444

2445
	/* Allocate without watermarks if the context allows */
2446
	if (alloc_flags & ALLOC_NO_WATERMARKS) {
2447 2448 2449 2450 2451 2452 2453
		/*
		 * Ignore mempolicies if ALLOC_NO_WATERMARKS on the grounds
		 * the allocation is high priority and these type of
		 * allocations are system rather than user orientated
		 */
		zonelist = node_zonelist(numa_node_id(), gfp_mask);

2454 2455 2456
		page = __alloc_pages_high_priority(gfp_mask, order,
				zonelist, high_zoneidx, nodemask,
				preferred_zone, migratetype);
2457
		if (page) {
2458
			goto got_pg;
2459
		}
L
Linus Torvalds 已提交
2460 2461 2462 2463 2464 2465
	}

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

2466
	/* Avoid recursion of direct reclaim */
2467
	if (current->flags & PF_MEMALLOC)
2468 2469
		goto nopage;

2470 2471 2472 2473
	/* Avoid allocations with no watermarks from looping endlessly */
	if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
		goto nopage;

2474 2475 2476 2477
	/*
	 * Try direct compaction. The first pass is asynchronous. Subsequent
	 * attempts after direct reclaim are synchronous
	 */
2478 2479 2480 2481
	page = __alloc_pages_direct_compact(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
					alloc_flags, preferred_zone,
2482
					migratetype, sync_migration,
2483
					&contended_compaction,
2484 2485
					&deferred_compaction,
					&did_some_progress);
2486 2487
	if (page)
		goto got_pg;
2488
	sync_migration = true;
2489

2490 2491 2492
	/*
	 * If compaction is deferred for high-order allocations, it is because
	 * sync compaction recently failed. In this is the case and the caller
2493 2494
	 * requested a movable allocation that does not heavily disrupt the
	 * system then fail the allocation instead of entering direct reclaim.
2495
	 */
2496
	if ((deferred_compaction || contended_compaction) &&
R
Rik van Riel 已提交
2497
	    (gfp_mask & (__GFP_MOVABLE|__GFP_REPEAT)) == __GFP_MOVABLE)
2498 2499
		goto nopage;

2500 2501 2502 2503
	/* Try direct reclaim and then allocating */
	page = __alloc_pages_direct_reclaim(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
2504
					alloc_flags, preferred_zone,
2505
					migratetype, &did_some_progress);
2506 2507
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
2508

2509
	/*
2510 2511
	 * If we failed to make any progress reclaiming, then we are
	 * running out of options and have to consider going OOM
2512
	 */
2513 2514
	if (!did_some_progress) {
		if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
2515 2516
			if (oom_killer_disabled)
				goto nopage;
2517 2518 2519 2520
			/* Coredumps can quickly deplete all memory reserves */
			if ((current->flags & PF_DUMPCORE) &&
			    !(gfp_mask & __GFP_NOFAIL))
				goto nopage;
2521 2522
			page = __alloc_pages_may_oom(gfp_mask, order,
					zonelist, high_zoneidx,
2523 2524
					nodemask, preferred_zone,
					migratetype);
2525 2526
			if (page)
				goto got_pg;
L
Linus Torvalds 已提交
2527

2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544
			if (!(gfp_mask & __GFP_NOFAIL)) {
				/*
				 * The oom killer is not called for high-order
				 * allocations that may fail, so if no progress
				 * is being made, there are no other options and
				 * retrying is unlikely to help.
				 */
				if (order > PAGE_ALLOC_COSTLY_ORDER)
					goto nopage;
				/*
				 * The oom killer is not called for lowmem
				 * allocations to prevent needlessly killing
				 * innocent tasks.
				 */
				if (high_zoneidx < ZONE_NORMAL)
					goto nopage;
			}
2545

2546 2547
			goto restart;
		}
L
Linus Torvalds 已提交
2548 2549
	}

2550
	/* Check if we should retry the allocation */
2551
	pages_reclaimed += did_some_progress;
2552 2553
	if (should_alloc_retry(gfp_mask, order, did_some_progress,
						pages_reclaimed)) {
2554
		/* Wait for some write requests to complete then retry */
2555
		wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
L
Linus Torvalds 已提交
2556
		goto rebalance;
2557 2558 2559 2560 2561 2562 2563 2564 2565 2566
	} else {
		/*
		 * High-order allocations do not necessarily loop after
		 * direct reclaim and reclaim/compaction depends on compaction
		 * being called after reclaim so call directly if necessary
		 */
		page = __alloc_pages_direct_compact(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
					alloc_flags, preferred_zone,
2567
					migratetype, sync_migration,
2568
					&contended_compaction,
2569 2570
					&deferred_compaction,
					&did_some_progress);
2571 2572
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
2573 2574 2575
	}

nopage:
2576
	warn_alloc_failed(gfp_mask, order, NULL);
2577
	return page;
L
Linus Torvalds 已提交
2578
got_pg:
2579 2580
	if (kmemcheck_enabled)
		kmemcheck_pagealloc_alloc(page, order, gfp_mask);
2581

2582
	return page;
L
Linus Torvalds 已提交
2583
}
2584 2585 2586 2587 2588 2589 2590 2591 2592

/*
 * This is the 'heart' of the zoned buddy allocator.
 */
struct page *
__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
			struct zonelist *zonelist, nodemask_t *nodemask)
{
	enum zone_type high_zoneidx = gfp_zone(gfp_mask);
2593
	struct zone *preferred_zone;
2594
	struct page *page = NULL;
2595
	int migratetype = allocflags_to_migratetype(gfp_mask);
2596
	unsigned int cpuset_mems_cookie;
2597
	int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET;
2598

2599 2600
	gfp_mask &= gfp_allowed_mask;

2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615
	lockdep_trace_alloc(gfp_mask);

	might_sleep_if(gfp_mask & __GFP_WAIT);

	if (should_fail_alloc_page(gfp_mask, order))
		return NULL;

	/*
	 * Check the zones suitable for the gfp_mask contain at least one
	 * valid zone. It's possible to have an empty zonelist as a result
	 * of GFP_THISNODE and a memoryless node
	 */
	if (unlikely(!zonelist->_zonerefs->zone))
		return NULL;

2616 2617 2618
retry_cpuset:
	cpuset_mems_cookie = get_mems_allowed();

2619
	/* The preferred zone is used for statistics later */
2620 2621 2622
	first_zones_zonelist(zonelist, high_zoneidx,
				nodemask ? : &cpuset_current_mems_allowed,
				&preferred_zone);
2623 2624
	if (!preferred_zone)
		goto out;
2625

2626 2627 2628 2629
#ifdef CONFIG_CMA
	if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
		alloc_flags |= ALLOC_CMA;
#endif
2630
	/* First allocation attempt */
2631
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
2632
			zonelist, high_zoneidx, alloc_flags,
2633
			preferred_zone, migratetype);
2634 2635
	if (unlikely(!page))
		page = __alloc_pages_slowpath(gfp_mask, order,
2636
				zonelist, high_zoneidx, nodemask,
2637
				preferred_zone, migratetype);
2638

2639
	trace_mm_page_alloc(page, order, gfp_mask, migratetype);
2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650

out:
	/*
	 * When updating a task's mems_allowed, it is possible to race with
	 * parallel threads in such a way that an allocation can fail while
	 * the mask is being updated. If a page allocation is about to fail,
	 * check if the cpuset changed during allocation and if so, retry.
	 */
	if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
		goto retry_cpuset;

2651
	return page;
L
Linus Torvalds 已提交
2652
}
2653
EXPORT_SYMBOL(__alloc_pages_nodemask);
L
Linus Torvalds 已提交
2654 2655 2656 2657

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
2658
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
2659
{
2660 2661 2662 2663 2664 2665 2666 2667
	struct page *page;

	/*
	 * __get_free_pages() returns a 32-bit address, which cannot represent
	 * a highmem page
	 */
	VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);

L
Linus Torvalds 已提交
2668 2669 2670 2671 2672 2673 2674
	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
2675
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
2676
{
2677
	return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
L
Linus Torvalds 已提交
2678 2679 2680
}
EXPORT_SYMBOL(get_zeroed_page);

H
Harvey Harrison 已提交
2681
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
2682
{
N
Nick Piggin 已提交
2683
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
2684
		if (order == 0)
L
Li Hong 已提交
2685
			free_hot_cold_page(page, 0);
L
Linus Torvalds 已提交
2686 2687 2688 2689 2690 2691 2692
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
2693
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
2694 2695
{
	if (addr != 0) {
N
Nick Piggin 已提交
2696
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
2697 2698 2699 2700 2701 2702
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

A
Andi Kleen 已提交
2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717
static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
{
	if (addr) {
		unsigned long alloc_end = addr + (PAGE_SIZE << order);
		unsigned long used = addr + PAGE_ALIGN(size);

		split_page(virt_to_page((void *)addr), order);
		while (used < alloc_end) {
			free_page(used);
			used += PAGE_SIZE;
		}
	}
	return (void *)addr;
}

2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736
/**
 * alloc_pages_exact - allocate an exact number physically-contiguous pages.
 * @size: the number of bytes to allocate
 * @gfp_mask: GFP flags for the allocation
 *
 * This function is similar to alloc_pages(), except that it allocates the
 * minimum number of pages to satisfy the request.  alloc_pages() can only
 * allocate memory in power-of-two pages.
 *
 * This function is also limited by MAX_ORDER.
 *
 * Memory allocated by this function must be released by free_pages_exact().
 */
void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
{
	unsigned int order = get_order(size);
	unsigned long addr;

	addr = __get_free_pages(gfp_mask, order);
A
Andi Kleen 已提交
2737
	return make_alloc_exact(addr, order, size);
2738 2739 2740
}
EXPORT_SYMBOL(alloc_pages_exact);

A
Andi Kleen 已提交
2741 2742 2743
/**
 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
 *			   pages on a node.
2744
 * @nid: the preferred node ID where memory should be allocated
A
Andi Kleen 已提交
2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762
 * @size: the number of bytes to allocate
 * @gfp_mask: GFP flags for the allocation
 *
 * Like alloc_pages_exact(), but try to allocate on node nid first before falling
 * back.
 * Note this is not alloc_pages_exact_node() which allocates on a specific node,
 * but is not exact.
 */
void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
{
	unsigned order = get_order(size);
	struct page *p = alloc_pages_node(nid, gfp_mask, order);
	if (!p)
		return NULL;
	return make_alloc_exact((unsigned long)page_address(p), order, size);
}
EXPORT_SYMBOL(alloc_pages_exact_nid);

2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781
/**
 * free_pages_exact - release memory allocated via alloc_pages_exact()
 * @virt: the value returned by alloc_pages_exact.
 * @size: size of allocation, same value as passed to alloc_pages_exact().
 *
 * Release the memory allocated by a previous call to alloc_pages_exact.
 */
void free_pages_exact(void *virt, size_t size)
{
	unsigned long addr = (unsigned long)virt;
	unsigned long end = addr + PAGE_ALIGN(size);

	while (addr < end) {
		free_page(addr);
		addr += PAGE_SIZE;
	}
}
EXPORT_SYMBOL(free_pages_exact);

L
Linus Torvalds 已提交
2782 2783
static unsigned int nr_free_zone_pages(int offset)
{
2784
	struct zoneref *z;
2785 2786
	struct zone *zone;

2787
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
2788 2789
	unsigned int sum = 0;

2790
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
2791

2792
	for_each_zone_zonelist(zone, z, zonelist, offset) {
2793
		unsigned long size = zone->present_pages;
2794
		unsigned long high = high_wmark_pages(zone);
2795 2796
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
2797 2798 2799 2800 2801 2802 2803 2804 2805 2806
	}

	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
2807
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
2808
}
2809
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
2810 2811 2812 2813 2814 2815

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
2816
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
2817
}
2818 2819

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
2820
{
2821
	if (NUMA_BUILD)
2822
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
2823 2824 2825 2826 2827 2828
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
2829
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843
	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;
2844
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
2845
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2846
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2847 2848
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
2849 2850 2851 2852
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
2853 2854 2855 2856
	val->mem_unit = PAGE_SIZE;
}
#endif

2857
/*
2858 2859
 * Determine whether the node should be displayed or not, depending on whether
 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2860
 */
2861
bool skip_free_areas_node(unsigned int flags, int nid)
2862 2863
{
	bool ret = false;
2864
	unsigned int cpuset_mems_cookie;
2865 2866 2867 2868

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

2869 2870 2871 2872
	do {
		cpuset_mems_cookie = get_mems_allowed();
		ret = !node_isset(nid, cpuset_current_mems_allowed);
	} while (!put_mems_allowed(cpuset_mems_cookie));
2873 2874 2875 2876
out:
	return ret;
}

L
Linus Torvalds 已提交
2877 2878 2879 2880 2881 2882
#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.
2883 2884
 * Suppresses nodes that are not allowed by current's cpuset if
 * SHOW_MEM_FILTER_NODES is passed.
L
Linus Torvalds 已提交
2885
 */
2886
void show_free_areas(unsigned int filter)
L
Linus Torvalds 已提交
2887
{
2888
	int cpu;
L
Linus Torvalds 已提交
2889 2890
	struct zone *zone;

2891
	for_each_populated_zone(zone) {
2892
		if (skip_free_areas_node(filter, zone_to_nid(zone)))
2893
			continue;
2894 2895
		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
2896

2897
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
2898 2899
			struct per_cpu_pageset *pageset;

2900
			pageset = per_cpu_ptr(zone->pageset, cpu);
L
Linus Torvalds 已提交
2901

2902 2903 2904
			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
2905 2906 2907
		}
	}

K
KOSAKI Motohiro 已提交
2908 2909
	printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
		" active_file:%lu inactive_file:%lu isolated_file:%lu\n"
L
Lee Schermerhorn 已提交
2910
		" unevictable:%lu"
2911
		" dirty:%lu writeback:%lu unstable:%lu\n"
2912
		" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2913 2914
		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
		" free_cma:%lu\n",
2915 2916
		global_page_state(NR_ACTIVE_ANON),
		global_page_state(NR_INACTIVE_ANON),
K
KOSAKI Motohiro 已提交
2917 2918
		global_page_state(NR_ISOLATED_ANON),
		global_page_state(NR_ACTIVE_FILE),
2919
		global_page_state(NR_INACTIVE_FILE),
K
KOSAKI Motohiro 已提交
2920
		global_page_state(NR_ISOLATED_FILE),
L
Lee Schermerhorn 已提交
2921
		global_page_state(NR_UNEVICTABLE),
2922
		global_page_state(NR_FILE_DIRTY),
2923
		global_page_state(NR_WRITEBACK),
2924
		global_page_state(NR_UNSTABLE_NFS),
2925
		global_page_state(NR_FREE_PAGES),
2926 2927
		global_page_state(NR_SLAB_RECLAIMABLE),
		global_page_state(NR_SLAB_UNRECLAIMABLE),
2928
		global_page_state(NR_FILE_MAPPED),
2929
		global_page_state(NR_SHMEM),
2930
		global_page_state(NR_PAGETABLE),
2931 2932
		global_page_state(NR_BOUNCE),
		global_page_state(NR_FREE_CMA_PAGES));
L
Linus Torvalds 已提交
2933

2934
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
2935 2936
		int i;

2937
		if (skip_free_areas_node(filter, zone_to_nid(zone)))
2938
			continue;
L
Linus Torvalds 已提交
2939 2940 2941 2942 2943 2944
		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
2945 2946 2947 2948
			" active_anon:%lukB"
			" inactive_anon:%lukB"
			" active_file:%lukB"
			" inactive_file:%lukB"
L
Lee Schermerhorn 已提交
2949
			" unevictable:%lukB"
K
KOSAKI Motohiro 已提交
2950 2951
			" isolated(anon):%lukB"
			" isolated(file):%lukB"
L
Linus Torvalds 已提交
2952
			" present:%lukB"
2953 2954 2955 2956
			" mlocked:%lukB"
			" dirty:%lukB"
			" writeback:%lukB"
			" mapped:%lukB"
2957
			" shmem:%lukB"
2958 2959
			" slab_reclaimable:%lukB"
			" slab_unreclaimable:%lukB"
2960
			" kernel_stack:%lukB"
2961 2962 2963
			" pagetables:%lukB"
			" unstable:%lukB"
			" bounce:%lukB"
2964
			" free_cma:%lukB"
2965
			" writeback_tmp:%lukB"
L
Linus Torvalds 已提交
2966 2967 2968 2969
			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
2970
			K(zone_page_state(zone, NR_FREE_PAGES)),
2971 2972 2973
			K(min_wmark_pages(zone)),
			K(low_wmark_pages(zone)),
			K(high_wmark_pages(zone)),
2974 2975 2976 2977
			K(zone_page_state(zone, NR_ACTIVE_ANON)),
			K(zone_page_state(zone, NR_INACTIVE_ANON)),
			K(zone_page_state(zone, NR_ACTIVE_FILE)),
			K(zone_page_state(zone, NR_INACTIVE_FILE)),
L
Lee Schermerhorn 已提交
2978
			K(zone_page_state(zone, NR_UNEVICTABLE)),
K
KOSAKI Motohiro 已提交
2979 2980
			K(zone_page_state(zone, NR_ISOLATED_ANON)),
			K(zone_page_state(zone, NR_ISOLATED_FILE)),
L
Linus Torvalds 已提交
2981
			K(zone->present_pages),
2982 2983 2984 2985
			K(zone_page_state(zone, NR_MLOCK)),
			K(zone_page_state(zone, NR_FILE_DIRTY)),
			K(zone_page_state(zone, NR_WRITEBACK)),
			K(zone_page_state(zone, NR_FILE_MAPPED)),
2986
			K(zone_page_state(zone, NR_SHMEM)),
2987 2988
			K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
			K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
2989 2990
			zone_page_state(zone, NR_KERNEL_STACK) *
				THREAD_SIZE / 1024,
2991 2992 2993
			K(zone_page_state(zone, NR_PAGETABLE)),
			K(zone_page_state(zone, NR_UNSTABLE_NFS)),
			K(zone_page_state(zone, NR_BOUNCE)),
2994
			K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
2995
			K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
L
Linus Torvalds 已提交
2996
			zone->pages_scanned,
2997
			(zone->all_unreclaimable ? "yes" : "no")
L
Linus Torvalds 已提交
2998 2999 3000 3001 3002 3003 3004
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

3005
	for_each_populated_zone(zone) {
3006
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
L
Linus Torvalds 已提交
3007

3008
		if (skip_free_areas_node(filter, zone_to_nid(zone)))
3009
			continue;
L
Linus Torvalds 已提交
3010 3011 3012 3013 3014
		show_node(zone);
		printk("%s: ", zone->name);

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
3015 3016
			nr[order] = zone->free_area[order].nr_free;
			total += nr[order] << order;
L
Linus Torvalds 已提交
3017 3018
		}
		spin_unlock_irqrestore(&zone->lock, flags);
3019 3020
		for (order = 0; order < MAX_ORDER; order++)
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
L
Linus Torvalds 已提交
3021 3022 3023
		printk("= %lukB\n", K(total));
	}

3024 3025
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

L
Linus Torvalds 已提交
3026 3027 3028
	show_swap_cache_info();
}

3029 3030 3031 3032 3033 3034
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
3035 3036
/*
 * Builds allocation fallback zone lists.
3037 3038
 *
 * Add all populated zones of a node to the zonelist.
L
Linus Torvalds 已提交
3039
 */
3040 3041
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
3042
{
3043 3044
	struct zone *zone;

3045
	BUG_ON(zone_type >= MAX_NR_ZONES);
3046
	zone_type++;
3047 3048

	do {
3049
		zone_type--;
3050
		zone = pgdat->node_zones + zone_type;
3051
		if (populated_zone(zone)) {
3052 3053
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
3054
			check_highest_zone(zone_type);
L
Linus Torvalds 已提交
3055
		}
3056

3057
	} while (zone_type);
3058
	return nr_zones;
L
Linus Torvalds 已提交
3059 3060
}

3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081

/*
 *  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
3082
#ifdef CONFIG_NUMA
3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115
/* 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)
{
3116 3117 3118 3119 3120 3121 3122 3123 3124 3125
	int ret;

	if (!s)
		return 0;

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

	return ret;
3126 3127 3128 3129 3130 3131 3132
}
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,
3133
		void __user *buffer, size_t *length,
3134 3135 3136 3137
		loff_t *ppos)
{
	char saved_string[NUMA_ZONELIST_ORDER_LEN];
	int ret;
3138
	static DEFINE_MUTEX(zl_order_mutex);
3139

3140
	mutex_lock(&zl_order_mutex);
3141
	if (write)
3142
		strcpy(saved_string, (char*)table->data);
3143
	ret = proc_dostring(table, write, buffer, length, ppos);
3144
	if (ret)
3145
		goto out;
3146 3147 3148 3149 3150 3151 3152 3153 3154
	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;
3155 3156
		} else if (oldval != user_zonelist_order) {
			mutex_lock(&zonelists_mutex);
3157
			build_all_zonelists(NULL, NULL);
3158 3159
			mutex_unlock(&zonelists_mutex);
		}
3160
	}
3161 3162 3163
out:
	mutex_unlock(&zl_order_mutex);
	return ret;
3164 3165 3166
}


3167
#define MAX_NODE_LOAD (nr_online_nodes)
3168 3169
static int node_load[MAX_NUMNODES];

L
Linus Torvalds 已提交
3170
/**
3171
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
Linus Torvalds 已提交
3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183
 * @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.
 */
3184
static int find_next_best_node(int node, nodemask_t *used_node_mask)
L
Linus Torvalds 已提交
3185
{
3186
	int n, val;
L
Linus Torvalds 已提交
3187 3188
	int min_val = INT_MAX;
	int best_node = -1;
3189
	const struct cpumask *tmp = cpumask_of_node(0);
L
Linus Torvalds 已提交
3190

3191 3192 3193 3194 3195
	/* 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
3196

3197
	for_each_node_state(n, N_HIGH_MEMORY) {
L
Linus Torvalds 已提交
3198 3199 3200 3201 3202 3203 3204 3205

		/* 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);

3206 3207 3208
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
Linus Torvalds 已提交
3209
		/* Give preference to headless and unused nodes */
3210 3211
		tmp = cpumask_of_node(n);
		if (!cpumask_empty(tmp))
L
Linus Torvalds 已提交
3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229
			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;
}

3230 3231 3232 3233 3234 3235 3236

/*
 * 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
3237
{
3238
	int j;
L
Linus Torvalds 已提交
3239
	struct zonelist *zonelist;
3240

3241
	zonelist = &pgdat->node_zonelists[0];
3242
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
3243 3244 3245
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
3246 3247
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
3248 3249
}

3250 3251 3252 3253 3254 3255 3256 3257
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

3258 3259
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
3260 3261
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
3262 3263
}

3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278
/*
 * 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;

3279 3280 3281 3282 3283 3284 3285
	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)) {
3286 3287
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
3288
				check_highest_zone(zone_type);
3289 3290 3291
			}
		}
	}
3292 3293
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
3294 3295 3296 3297 3298 3299 3300 3301 3302
}

static int default_zonelist_order(void)
{
	int nid, zone_type;
	unsigned long low_kmem_size,total_size;
	struct zone *z;
	int average_size;
	/*
T
Thomas Weber 已提交
3303
         * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3304 3305
	 * If they are really small and used heavily, the system can fall
	 * into OOM very easily.
3306
	 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317
	 */
	/* 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;
3318 3319 3320 3321 3322 3323 3324 3325 3326
			} else if (zone_type == ZONE_NORMAL) {
				/*
				 * If any node has only lowmem, then node order
				 * is preferred to allow kernel allocations
				 * locally; otherwise, they can easily infringe
				 * on other nodes when there is an abundance of
				 * lowmem available to allocate from.
				 */
				return ZONELIST_ORDER_NODE;
3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337
			}
		}
	}
	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.
         */
3338 3339
	average_size = total_size /
				(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370
	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
3371
	nodemask_t used_mask;
3372 3373 3374
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
L
Linus Torvalds 已提交
3375 3376

	/* initialize zonelists */
3377
	for (i = 0; i < MAX_ZONELISTS; i++) {
L
Linus Torvalds 已提交
3378
		zonelist = pgdat->node_zonelists + i;
3379 3380
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
L
Linus Torvalds 已提交
3381 3382 3383 3384
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
3385
	load = nr_online_nodes;
L
Linus Torvalds 已提交
3386 3387
	prev_node = local_node;
	nodes_clear(used_mask);
3388 3389 3390 3391

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

L
Linus Torvalds 已提交
3392 3393 3394 3395 3396 3397
	while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
		/*
		 * 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.
		 */
3398 3399
		if (node_distance(local_node, node) !=
		    node_distance(local_node, prev_node))
3400 3401
			node_load[node] = load;

L
Linus Torvalds 已提交
3402 3403
		prev_node = node;
		load--;
3404 3405 3406 3407 3408
		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
3409

3410 3411 3412
	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
3413
	}
3414 3415

	build_thisnode_zonelists(pgdat);
L
Linus Torvalds 已提交
3416 3417
}

3418
/* Construct the zonelist performance cache - see further mmzone.h */
3419
static void build_zonelist_cache(pg_data_t *pgdat)
3420
{
3421 3422
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
3423
	struct zoneref *z;
3424

3425 3426 3427
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3428 3429
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3430 3431
}

3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449
#ifdef CONFIG_HAVE_MEMORYLESS_NODES
/*
 * Return node id of node used for "local" allocations.
 * I.e., first node id of first zone in arg node's generic zonelist.
 * Used for initializing percpu 'numa_mem', which is used primarily
 * for kernel allocations, so use GFP_KERNEL flags to locate zonelist.
 */
int local_memory_node(int node)
{
	struct zone *zone;

	(void)first_zones_zonelist(node_zonelist(node, GFP_KERNEL),
				   gfp_zone(GFP_KERNEL),
				   NULL,
				   &zone);
	return zone->node;
}
#endif
3450

L
Linus Torvalds 已提交
3451 3452
#else	/* CONFIG_NUMA */

3453 3454 3455 3456 3457 3458
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
3459
{
3460
	int node, local_node;
3461 3462
	enum zone_type j;
	struct zonelist *zonelist;
L
Linus Torvalds 已提交
3463 3464 3465

	local_node = pgdat->node_id;

3466 3467
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
3468

3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481
	/*
	 * 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
3482
	}
3483 3484 3485 3486 3487 3488 3489
	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);
	}

3490 3491
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
L
Linus Torvalds 已提交
3492 3493
}

3494
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3495
static void build_zonelist_cache(pg_data_t *pgdat)
3496
{
3497
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
3498 3499
}

L
Linus Torvalds 已提交
3500 3501
#endif	/* CONFIG_NUMA */

3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518
/*
 * Boot pageset table. One per cpu which is going to be used for all
 * zones and all nodes. The parameters will be set in such a way
 * that an item put on a list will immediately be handed over to
 * the buddy list. This is safe since pageset manipulation is done
 * with interrupts disabled.
 *
 * The boot_pagesets must be kept even after bootup is complete for
 * unused processors and/or zones. They do play a role for bootstrapping
 * hotplugged processors.
 *
 * zoneinfo_show() and maybe other functions do
 * not check if the processor is online before following the pageset pointer.
 * Other parts of the kernel may not check if the zone is available.
 */
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
3519
static void setup_zone_pageset(struct zone *zone);
3520

3521 3522 3523 3524 3525 3526
/*
 * Global mutex to protect against size modification of zonelists
 * as well as to serialize pageset setup for the new populated zone.
 */
DEFINE_MUTEX(zonelists_mutex);

3527
/* return values int ....just for stop_machine() */
3528
static int __build_all_zonelists(void *data)
L
Linus Torvalds 已提交
3529
{
3530
	int nid;
3531
	int cpu;
3532
	pg_data_t *self = data;
3533

3534 3535 3536
#ifdef CONFIG_NUMA
	memset(node_load, 0, sizeof(node_load));
#endif
3537 3538 3539 3540 3541 3542

	if (self && !node_online(self->node_id)) {
		build_zonelists(self);
		build_zonelist_cache(self);
	}

3543
	for_each_online_node(nid) {
3544 3545 3546 3547
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
3548
	}
3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562

	/*
	 * Initialize the boot_pagesets that are going to be used
	 * for bootstrapping processors. The real pagesets for
	 * each zone will be allocated later when the per cpu
	 * allocator is available.
	 *
	 * boot_pagesets are used also for bootstrapping offline
	 * cpus if the system is already booted because the pagesets
	 * are needed to initialize allocators on a specific cpu too.
	 * F.e. the percpu allocator needs the page allocator which
	 * needs the percpu allocator in order to allocate its pagesets
	 * (a chicken-egg dilemma).
	 */
3563
	for_each_possible_cpu(cpu) {
3564 3565
		setup_pageset(&per_cpu(boot_pageset, cpu), 0);

3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579
#ifdef CONFIG_HAVE_MEMORYLESS_NODES
		/*
		 * We now know the "local memory node" for each node--
		 * i.e., the node of the first zone in the generic zonelist.
		 * Set up numa_mem percpu variable for on-line cpus.  During
		 * boot, only the boot cpu should be on-line;  we'll init the
		 * secondary cpus' numa_mem as they come on-line.  During
		 * node/memory hotplug, we'll fixup all on-line cpus.
		 */
		if (cpu_online(cpu))
			set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu)));
#endif
	}

3580 3581 3582
	return 0;
}

3583 3584 3585 3586
/*
 * Called with zonelists_mutex held always
 * unless system_state == SYSTEM_BOOTING.
 */
3587
void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
3588
{
3589 3590
	set_zonelist_order();

3591
	if (system_state == SYSTEM_BOOTING) {
3592
		__build_all_zonelists(NULL);
3593
		mminit_verify_zonelist();
3594 3595
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
3596
		/* we have to stop all cpus to guarantee there is no user
3597
		   of zonelist */
3598
#ifdef CONFIG_MEMORY_HOTPLUG
3599 3600
		if (zone)
			setup_zone_pageset(zone);
3601
#endif
3602
		stop_machine(__build_all_zonelists, pgdat, NULL);
3603 3604
		/* cpuset refresh routine should be here */
	}
3605
	vm_total_pages = nr_free_pagecache_pages();
3606 3607 3608 3609 3610 3611 3612
	/*
	 * 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
	 */
3613
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
3614 3615 3616 3617 3618 3619
		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",
3620
			nr_online_nodes,
3621
			zonelist_order_name[current_zonelist_order],
3622
			page_group_by_mobility_disabled ? "off" : "on",
3623 3624 3625 3626
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
L
Linus Torvalds 已提交
3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641
}

/*
 * 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

3642
#ifndef CONFIG_MEMORY_HOTPLUG
3643
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660
{
	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);
}
3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683
#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
3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696

/*
 * 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))

3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710
/*
 * Check if a pageblock contains reserved pages
 */
static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn)
{
	unsigned long pfn;

	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
		if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn)))
			return 1;
	}
	return 0;
}

3711
/*
3712
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3713 3714
 * of blocks reserved is based on min_wmark_pages(zone). The memory within
 * the reserve will tend to store contiguous free pages. Setting min_free_kbytes
3715 3716 3717 3718 3719
 * 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)
{
3720
	unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
3721
	struct page *page;
3722 3723
	unsigned long block_migratetype;
	int reserve;
3724

3725 3726 3727 3728 3729 3730
	/*
	 * Get the start pfn, end pfn and the number of blocks to reserve
	 * We have to be careful to be aligned to pageblock_nr_pages to
	 * make sure that we always check pfn_valid for the first page in
	 * the block.
	 */
3731 3732
	start_pfn = zone->zone_start_pfn;
	end_pfn = start_pfn + zone->spanned_pages;
3733
	start_pfn = roundup(start_pfn, pageblock_nr_pages);
3734
	reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
3735
							pageblock_order;
3736

3737 3738 3739 3740 3741 3742 3743 3744 3745
	/*
	 * Reserve blocks are generally in place to help high-order atomic
	 * allocations that are short-lived. A min_free_kbytes value that
	 * would result in more than 2 reserve blocks for atomic allocations
	 * is assumed to be in place to help anti-fragmentation for the
	 * future allocation of hugepages at runtime.
	 */
	reserve = min(2, reserve);

3746
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
3747 3748 3749 3750
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

3751 3752 3753 3754
		/* Watch out for overlapping nodes */
		if (page_to_nid(page) != zone_to_nid(zone))
			continue;

3755 3756
		block_migratetype = get_pageblock_migratetype(page);

3757 3758 3759 3760 3761 3762 3763 3764 3765
		/* Only test what is necessary when the reserves are not met */
		if (reserve > 0) {
			/*
			 * Blocks with reserved pages will never free, skip
			 * them.
			 */
			block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
			if (pageblock_is_reserved(pfn, block_end_pfn))
				continue;
3766

3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781
			/* If this block is reserved, account for it */
			if (block_migratetype == MIGRATE_RESERVE) {
				reserve--;
				continue;
			}

			/* Suitable for reserving if this block is movable */
			if (block_migratetype == MIGRATE_MOVABLE) {
				set_pageblock_migratetype(page,
							MIGRATE_RESERVE);
				move_freepages_block(zone, page,
							MIGRATE_RESERVE);
				reserve--;
				continue;
			}
3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793
		}

		/*
		 * 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
3794

L
Linus Torvalds 已提交
3795 3796 3797 3798 3799
/*
 * 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.
 */
3800
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
3801
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
3802 3803
{
	struct page *page;
A
Andy Whitcroft 已提交
3804 3805
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
3806
	struct zone *z;
L
Linus Torvalds 已提交
3807

3808 3809 3810
	if (highest_memmap_pfn < end_pfn - 1)
		highest_memmap_pfn = end_pfn - 1;

3811
	z = &NODE_DATA(nid)->node_zones[zone];
3812
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823
		/*
		 * 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
3824 3825
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
3826
		mminit_verify_page_links(page, zone, nid, pfn);
3827
		init_page_count(page);
L
Linus Torvalds 已提交
3828 3829
		reset_page_mapcount(page);
		SetPageReserved(page);
3830 3831 3832 3833 3834
		/*
		 * 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
3835 3836 3837
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
3838 3839 3840 3841 3842
		 *
		 * bitmap is created for zone's valid pfn range. but memmap
		 * can be created for invalid pages (for alignment)
		 * check here not to call set_pageblock_migratetype() against
		 * pfn out of zone.
3843
		 */
3844 3845 3846
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
3847
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
3848

L
Linus Torvalds 已提交
3849 3850 3851 3852
		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))
3853
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
3854 3855 3856 3857
#endif
	}
}

3858
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
3859
{
3860 3861 3862
	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
3863 3864 3865 3866 3867 3868
		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
3869
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
3870 3871
#endif

3872
static int __meminit zone_batchsize(struct zone *zone)
3873
{
3874
#ifdef CONFIG_MMU
3875 3876 3877 3878
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
3879
	 * size of the zone.  But no more than 1/2 of a meg.
3880 3881 3882 3883
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
3884 3885
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
3886 3887 3888 3889 3890
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
3891 3892 3893
	 * 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.
3894
	 *
3895 3896 3897 3898
	 * 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.
3899
	 */
3900
	batch = rounddown_pow_of_two(batch + batch/2) - 1;
3901

3902
	return batch;
3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913 3914 3915 3916 3917 3918 3919

#else
	/* The deferral and batching of frees should be suppressed under NOMMU
	 * conditions.
	 *
	 * The problem is that NOMMU needs to be able to allocate large chunks
	 * of contiguous memory as there's no hardware page translation to
	 * assemble apparent contiguous memory from discontiguous pages.
	 *
	 * Queueing large contiguous runs of pages for batching, however,
	 * causes the pages to actually be freed in smaller chunks.  As there
	 * can be a significant delay between the individual batches being
	 * recycled, this leads to the once large chunks of space being
	 * fragmented and becoming unavailable for high-order allocations.
	 */
	return 0;
#endif
3920 3921
}

A
Adrian Bunk 已提交
3922
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3923 3924
{
	struct per_cpu_pages *pcp;
3925
	int migratetype;
3926

3927 3928
	memset(p, 0, sizeof(*p));

3929
	pcp = &p->pcp;
3930 3931 3932
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
3933 3934
	for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
		INIT_LIST_HEAD(&pcp->lists[migratetype]);
3935 3936
}

3937 3938 3939 3940 3941 3942 3943 3944 3945 3946
/*
 * 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;

3947
	pcp = &p->pcp;
3948 3949 3950 3951 3952 3953
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}

3954
static void __meminit setup_zone_pageset(struct zone *zone)
3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971
{
	int cpu;

	zone->pageset = alloc_percpu(struct per_cpu_pageset);

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

		setup_pageset(pcp, zone_batchsize(zone));

		if (percpu_pagelist_fraction)
			setup_pagelist_highmark(pcp,
				(zone->present_pages /
					percpu_pagelist_fraction));
	}
}

3972
/*
3973 3974
 * Allocate per cpu pagesets and initialize them.
 * Before this call only boot pagesets were available.
3975
 */
3976
void __init setup_per_cpu_pageset(void)
3977
{
3978
	struct zone *zone;
3979

3980 3981
	for_each_populated_zone(zone)
		setup_zone_pageset(zone);
3982 3983
}

S
Sam Ravnborg 已提交
3984
static noinline __init_refok
3985
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
3986 3987 3988
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
3989
	size_t alloc_size;
3990 3991 3992 3993 3994

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
3995 3996 3997 3998
	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);
3999 4000 4001
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

4002
	if (!slab_is_available()) {
4003
		zone->wait_table = (wait_queue_head_t *)
4004
			alloc_bootmem_node_nopanic(pgdat, alloc_size);
4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015
	} 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.
		 */
4016
		zone->wait_table = vmalloc(alloc_size);
4017 4018 4019
	}
	if (!zone->wait_table)
		return -ENOMEM;
4020

4021
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
4022
		init_waitqueue_head(zone->wait_table + i);
4023 4024

	return 0;
4025 4026
}

4027
static __meminit void zone_pcp_init(struct zone *zone)
4028
{
4029 4030 4031 4032 4033 4034
	/*
	 * per cpu subsystem is not up at this point. The following code
	 * relies on the ability of the linker to provide the
	 * offset of a (static) per cpu variable into the per cpu area.
	 */
	zone->pageset = &boot_pageset;
4035

A
Anton Blanchard 已提交
4036
	if (zone->present_pages)
4037 4038 4039
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%u\n",
			zone->name, zone->present_pages,
					 zone_batchsize(zone));
4040 4041
}

4042
int __meminit init_currently_empty_zone(struct zone *zone,
4043
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
4044 4045
					unsigned long size,
					enum memmap_context context)
4046 4047
{
	struct pglist_data *pgdat = zone->zone_pgdat;
4048 4049 4050 4051
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
4052 4053 4054 4055
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

4056 4057 4058 4059 4060 4061
	mminit_dprintk(MMINIT_TRACE, "memmap_init",
			"Initialising map node %d zone %lu pfns %lu -> %lu\n",
			pgdat->node_id,
			(unsigned long)zone_idx(zone),
			zone_start_pfn, (zone_start_pfn + size));

4062
	zone_init_free_lists(zone);
4063 4064

	return 0;
4065 4066
}

T
Tejun Heo 已提交
4067
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4068 4069 4070 4071 4072 4073 4074
#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
 */
4075
int __meminit __early_pfn_to_nid(unsigned long pfn)
4076
{
4077 4078
	unsigned long start_pfn, end_pfn;
	int i, nid;
4079

4080
	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
4081
		if (start_pfn <= pfn && pfn < end_pfn)
4082
			return nid;
4083 4084
	/* This is a memory hole */
	return -1;
4085 4086 4087
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

4088 4089
int __meminit early_pfn_to_nid(unsigned long pfn)
{
4090 4091 4092 4093 4094 4095 4096
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0)
		return nid;
	/* just returns 0 */
	return 0;
4097 4098
}

4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109
#ifdef CONFIG_NODES_SPAN_OTHER_NODES
bool __meminit early_pfn_in_nid(unsigned long pfn, int node)
{
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0 && nid != node)
		return false;
	return true;
}
#endif
4110

4111 4112
/**
 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
4113 4114
 * @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
4115 4116 4117 4118 4119
 *
 * 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.
 */
4120
void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
4121
{
4122 4123
	unsigned long start_pfn, end_pfn;
	int i, this_nid;
4124

4125 4126 4127
	for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) {
		start_pfn = min(start_pfn, max_low_pfn);
		end_pfn = min(end_pfn, max_low_pfn);
4128

4129 4130 4131 4132
		if (start_pfn < end_pfn)
			free_bootmem_node(NODE_DATA(this_nid),
					  PFN_PHYS(start_pfn),
					  (end_pfn - start_pfn) << PAGE_SHIFT);
4133 4134 4135
	}
}

4136 4137
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4138
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4139 4140 4141
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
4142
 * function may be used instead of calling memory_present() manually.
4143 4144 4145
 */
void __init sparse_memory_present_with_active_regions(int nid)
{
4146 4147
	unsigned long start_pfn, end_pfn;
	int i, this_nid;
4148

4149 4150
	for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
		memory_present(this_nid, start_pfn, end_pfn);
4151 4152 4153 4154
}

/**
 * get_pfn_range_for_nid - Return the start and end page frames for a node
4155 4156 4157
 * @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.
4158 4159 4160 4161
 *
 * 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
4162
 * PFNs will be 0.
4163
 */
4164
void __meminit get_pfn_range_for_nid(unsigned int nid,
4165 4166
			unsigned long *start_pfn, unsigned long *end_pfn)
{
4167
	unsigned long this_start_pfn, this_end_pfn;
4168
	int i;
4169

4170 4171 4172
	*start_pfn = -1UL;
	*end_pfn = 0;

4173 4174 4175
	for_each_mem_pfn_range(i, nid, &this_start_pfn, &this_end_pfn, NULL) {
		*start_pfn = min(*start_pfn, this_start_pfn);
		*end_pfn = max(*end_pfn, this_end_pfn);
4176 4177
	}

4178
	if (*start_pfn == -1UL)
4179 4180 4181
		*start_pfn = 0;
}

M
Mel Gorman 已提交
4182 4183 4184 4185 4186
/*
 * This finds a zone that can be used for ZONE_MOVABLE pages. The
 * assumption is made that zones within a node are ordered in monotonic
 * increasing memory addresses so that the "highest" populated zone is used
 */
A
Adrian Bunk 已提交
4187
static void __init find_usable_zone_for_movable(void)
M
Mel Gorman 已提交
4188 4189 4190 4191 4192 4193 4194 4195 4196 4197 4198 4199 4200 4201 4202 4203 4204
{
	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
L
Lucas De Marchi 已提交
4205
 * because it is sized independent of architecture. Unlike the other zones,
M
Mel Gorman 已提交
4206 4207 4208 4209 4210 4211 4212
 * the starting point for ZONE_MOVABLE is not fixed. It may be different
 * in each node depending on the size of each node and how evenly kernelcore
 * is distributed. This helper function adjusts the zone ranges
 * provided by the architecture for a given node by using the end of the
 * highest usable zone for ZONE_MOVABLE. This preserves the assumption that
 * zones within a node are in order of monotonic increases memory addresses
 */
A
Adrian Bunk 已提交
4213
static void __meminit adjust_zone_range_for_zone_movable(int nid,
M
Mel Gorman 已提交
4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238
					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;
	}
}

4239 4240 4241 4242
/*
 * 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
4243
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
4244 4245 4246 4247 4248 4249 4250 4251 4252 4253
					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
4254 4255 4256
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271

	/* 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,
4272
 * then all holes in the requested range will be accounted for.
4273
 */
4274
unsigned long __meminit __absent_pages_in_range(int nid,
4275 4276 4277
				unsigned long range_start_pfn,
				unsigned long range_end_pfn)
{
4278 4279 4280
	unsigned long nr_absent = range_end_pfn - range_start_pfn;
	unsigned long start_pfn, end_pfn;
	int i;
4281

4282 4283 4284 4285
	for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
		start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
		end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
		nr_absent -= end_pfn - start_pfn;
4286
	}
4287
	return nr_absent;
4288 4289 4290 4291 4292 4293 4294
}

/**
 * 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
 *
4295
 * It returns the number of pages frames in memory holes within a range.
4296 4297 4298 4299 4300 4301 4302 4303
 */
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
4304
static unsigned long __meminit zone_absent_pages_in_node(int nid,
4305 4306 4307
					unsigned long zone_type,
					unsigned long *ignored)
{
4308 4309
	unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
	unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
4310 4311 4312 4313
	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);
4314 4315
	zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
	zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
4316

M
Mel Gorman 已提交
4317 4318 4319
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
4320
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
4321
}
4322

T
Tejun Heo 已提交
4323
#else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
P
Paul Mundt 已提交
4324
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
4325 4326 4327 4328 4329 4330
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
4331
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
4332 4333 4334 4335 4336 4337 4338 4339
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
4340

T
Tejun Heo 已提交
4341
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4342

4343
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
4344 4345 4346 4347 4348 4349 4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363
		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);
}

4364 4365 4366
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
4367 4368
 * 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
4369 4370 4371 4372 4373 4374 4375
 * 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;

4376 4377
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388
	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;
4389
	if (usemapsize)
4390 4391
		zone->pageblock_flags = alloc_bootmem_node_nopanic(pgdat,
								   usemapsize);
4392 4393
}
#else
4394
static inline void setup_usemap(struct pglist_data *pgdat,
4395 4396 4397
				struct zone *zone, unsigned long zonesize) {}
#endif /* CONFIG_SPARSEMEM */

4398
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4399

4400
/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4401
void __init set_pageblock_order(void)
4402
{
4403 4404
	unsigned int order;

4405 4406 4407 4408
	/* Check that pageblock_nr_pages has not already been setup */
	if (pageblock_order)
		return;

4409 4410 4411 4412 4413
	if (HPAGE_SHIFT > PAGE_SHIFT)
		order = HUGETLB_PAGE_ORDER;
	else
		order = MAX_ORDER - 1;

4414 4415
	/*
	 * Assume the largest contiguous order of interest is a huge page.
4416 4417
	 * This value may be variable depending on boot parameters on IA64 and
	 * powerpc.
4418 4419 4420 4421 4422
	 */
	pageblock_order = order;
}
#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

4423 4424
/*
 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4425 4426 4427
 * is 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
4428
 */
4429
void __init set_pageblock_order(void)
4430 4431
{
}
4432 4433 4434

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

L
Linus Torvalds 已提交
4435 4436 4437 4438 4439
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
4440 4441
 *
 * NOTE: pgdat should get zeroed by caller.
L
Linus Torvalds 已提交
4442
 */
4443
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
4444 4445
		unsigned long *zones_size, unsigned long *zholes_size)
{
4446
	enum zone_type j;
4447
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
4448
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
4449
	int ret;
L
Linus Torvalds 已提交
4450

4451
	pgdat_resize_init(pgdat);
L
Linus Torvalds 已提交
4452
	init_waitqueue_head(&pgdat->kswapd_wait);
4453
	init_waitqueue_head(&pgdat->pfmemalloc_wait);
4454
	pgdat_page_cgroup_init(pgdat);
4455

L
Linus Torvalds 已提交
4456 4457
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
4458
		unsigned long size, realsize, memmap_pages;
L
Linus Torvalds 已提交
4459

4460 4461 4462
		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
4463

4464 4465 4466 4467 4468
		/*
		 * 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
		 */
4469 4470
		memmap_pages =
			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
4471 4472
		if (realsize >= memmap_pages) {
			realsize -= memmap_pages;
4473 4474 4475 4476
			if (memmap_pages)
				printk(KERN_DEBUG
				       "  %s zone: %lu pages used for memmap\n",
				       zone_names[j], memmap_pages);
4477 4478 4479 4480 4481
		} else
			printk(KERN_WARNING
				"  %s zone: %lu pages exceeds realsize %lu\n",
				zone_names[j], memmap_pages, realsize);

4482 4483
		/* Account for reserved pages */
		if (j == 0 && realsize > dma_reserve) {
4484
			realsize -= dma_reserve;
Y
Yinghai Lu 已提交
4485
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
4486
					zone_names[0], dma_reserve);
4487 4488
		}

4489
		if (!is_highmem_idx(j))
L
Linus Torvalds 已提交
4490 4491 4492 4493 4494
			nr_kernel_pages += realsize;
		nr_all_pages += realsize;

		zone->spanned_pages = size;
		zone->present_pages = realsize;
4495
#ifdef CONFIG_NUMA
4496
		zone->node = nid;
4497
		zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
4498
						/ 100;
4499
		zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
4500
#endif
L
Linus Torvalds 已提交
4501 4502 4503
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
4504
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
4505 4506
		zone->zone_pgdat = pgdat;

4507
		zone_pcp_init(zone);
4508
		lruvec_init(&zone->lruvec);
L
Linus Torvalds 已提交
4509 4510 4511
		if (!size)
			continue;

4512
		set_pageblock_order();
4513
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
4514 4515
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
4516
		BUG_ON(ret);
4517
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
4518 4519 4520 4521
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
4522
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
4523 4524 4525 4526 4527
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
4528
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
4529 4530
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
4531
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
4532 4533
		struct page *map;

4534 4535 4536 4537 4538 4539 4540 4541 4542
		/*
		 * 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);
4543 4544
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
4545
			map = alloc_bootmem_node_nopanic(pgdat, size);
4546
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
4547
	}
4548
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
4549 4550 4551
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
4552
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
4553
		mem_map = NODE_DATA(0)->node_mem_map;
T
Tejun Heo 已提交
4554
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4555
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4556
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
T
Tejun Heo 已提交
4557
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4558
	}
L
Linus Torvalds 已提交
4559
#endif
A
Andy Whitcroft 已提交
4560
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
4561 4562
}

4563 4564
void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
		unsigned long node_start_pfn, unsigned long *zholes_size)
L
Linus Torvalds 已提交
4565
{
4566 4567
	pg_data_t *pgdat = NODE_DATA(nid);

4568
	/* pg_data_t should be reset to zero when it's allocated */
4569
	WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
4570

L
Linus Torvalds 已提交
4571 4572
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
4573
	init_zone_allows_reclaim(nid);
4574
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
4575 4576

	alloc_node_mem_map(pgdat);
4577 4578 4579 4580 4581
#ifdef CONFIG_FLAT_NODE_MEM_MAP
	printk(KERN_DEBUG "free_area_init_node: node %d, pgdat %08lx, node_mem_map %08lx\n",
		nid, (unsigned long)pgdat,
		(unsigned long)pgdat->node_mem_map);
#endif
L
Linus Torvalds 已提交
4582 4583 4584 4585

	free_area_init_core(pgdat, zones_size, zholes_size);
}

T
Tejun Heo 已提交
4586
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
M
Miklos Szeredi 已提交
4587 4588 4589 4590 4591 4592 4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603 4604 4605 4606

#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

4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628
/**
 * node_map_pfn_alignment - determine the maximum internode alignment
 *
 * This function should be called after node map is populated and sorted.
 * It calculates the maximum power of two alignment which can distinguish
 * all the nodes.
 *
 * For example, if all nodes are 1GiB and aligned to 1GiB, the return value
 * would indicate 1GiB alignment with (1 << (30 - PAGE_SHIFT)).  If the
 * nodes are shifted by 256MiB, 256MiB.  Note that if only the last node is
 * shifted, 1GiB is enough and this function will indicate so.
 *
 * This is used to test whether pfn -> nid mapping of the chosen memory
 * model has fine enough granularity to avoid incorrect mapping for the
 * populated node map.
 *
 * Returns the determined alignment in pfn's.  0 if there is no alignment
 * requirement (single node).
 */
unsigned long __init node_map_pfn_alignment(void)
{
	unsigned long accl_mask = 0, last_end = 0;
4629
	unsigned long start, end, mask;
4630
	int last_nid = -1;
4631
	int i, nid;
4632

4633
	for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
4634 4635 4636 4637 4638 4639 4640 4641 4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655 4656
		if (!start || last_nid < 0 || last_nid == nid) {
			last_nid = nid;
			last_end = end;
			continue;
		}

		/*
		 * Start with a mask granular enough to pin-point to the
		 * start pfn and tick off bits one-by-one until it becomes
		 * too coarse to separate the current node from the last.
		 */
		mask = ~((1 << __ffs(start)) - 1);
		while (mask && last_end <= (start & (mask << 1)))
			mask <<= 1;

		/* accumulate all internode masks */
		accl_mask |= mask;
	}

	/* convert mask to number of pages */
	return ~accl_mask + 1;
}

4657
/* Find the lowest pfn for a node */
A
Adrian Bunk 已提交
4658
static unsigned long __init find_min_pfn_for_node(int nid)
4659
{
4660
	unsigned long min_pfn = ULONG_MAX;
4661 4662
	unsigned long start_pfn;
	int i;
4663

4664 4665
	for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
		min_pfn = min(min_pfn, start_pfn);
4666

4667 4668
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
4669
			"Could not find start_pfn for node %d\n", nid);
4670 4671 4672 4673
		return 0;
	}

	return min_pfn;
4674 4675 4676 4677 4678 4679
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
4680
 * add_active_range().
4681 4682 4683 4684 4685 4686
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

4687 4688 4689 4690 4691
/*
 * 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
4692
static unsigned long __init early_calculate_totalpages(void)
4693 4694
{
	unsigned long totalpages = 0;
4695 4696 4697 4698 4699
	unsigned long start_pfn, end_pfn;
	int i, nid;

	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
		unsigned long pages = end_pfn - start_pfn;
4700

4701 4702
		totalpages += pages;
		if (pages)
4703
			node_set_state(nid, N_HIGH_MEMORY);
4704 4705
	}
  	return totalpages;
4706 4707
}

M
Mel Gorman 已提交
4708 4709 4710 4711 4712 4713
/*
 * 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
 */
4714
static void __init find_zone_movable_pfns_for_nodes(void)
M
Mel Gorman 已提交
4715 4716 4717 4718
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
4719 4720
	/* save the state before borrow the nodemask */
	nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
4721 4722
	unsigned long totalpages = early_calculate_totalpages();
	int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
M
Mel Gorman 已提交
4723

4724 4725 4726 4727 4728 4729 4730 4731 4732 4733 4734 4735 4736 4737 4738 4739 4740 4741 4742 4743 4744 4745
	/*
	 * 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
4746 4747
	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
	if (!required_kernelcore)
4748
		goto out;
M
Mel Gorman 已提交
4749 4750 4751 4752 4753 4754 4755 4756

	/* 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;
4757
	for_each_node_state(nid, N_HIGH_MEMORY) {
4758 4759
		unsigned long start_pfn, end_pfn;

M
Mel Gorman 已提交
4760 4761 4762 4763 4764 4765 4766 4767 4768 4769 4770 4771 4772 4773 4774 4775
		/*
		 * 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 */
4776
		for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
M
Mel Gorman 已提交
4777 4778
			unsigned long size_pages;

4779
			start_pfn = max(start_pfn, zone_movable_pfn[nid]);
M
Mel Gorman 已提交
4780 4781 4782 4783 4784 4785 4786 4787 4788 4789 4790 4791 4792 4793 4794 4795 4796 4797 4798 4799 4800 4801 4802 4803 4804 4805 4806 4807 4808 4809 4810 4811 4812 4813 4814 4815 4816 4817 4818 4819 4820 4821 4822 4823 4824 4825 4826 4827 4828 4829 4830 4831 4832 4833 4834 4835 4836 4837 4838 4839 4840 4841 4842 4843 4844 4845
			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);
4846 4847 4848 4849

out:
	/* restore the node_state */
	node_states[N_HIGH_MEMORY] = saved_node_state;
M
Mel Gorman 已提交
4850 4851
}

4852
/* Any regular memory on that node ? */
4853
static void __init check_for_regular_memory(pg_data_t *pgdat)
4854 4855 4856 4857 4858 4859
{
#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];
4860
		if (zone->present_pages) {
4861
			node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
4862 4863
			break;
		}
4864 4865 4866 4867
	}
#endif
}

4868 4869
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
4870
 * @max_zone_pfn: an array of max PFNs for each zone
4871 4872 4873 4874 4875 4876 4877 4878 4879 4880 4881 4882
 *
 * 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)
{
4883 4884
	unsigned long start_pfn, end_pfn;
	int i, nid;
4885

4886 4887 4888 4889 4890 4891 4892 4893
	/* 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
4894 4895
		if (i == ZONE_MOVABLE)
			continue;
4896 4897 4898 4899 4900
		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
4901 4902 4903 4904 4905
	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));
4906
	find_zone_movable_pfns_for_nodes();
4907 4908

	/* Print out the zone ranges */
4909
	printk("Zone ranges:\n");
M
Mel Gorman 已提交
4910 4911 4912
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
4913
		printk(KERN_CONT "  %-8s ", zone_names[i]);
4914 4915
		if (arch_zone_lowest_possible_pfn[i] ==
				arch_zone_highest_possible_pfn[i])
4916
			printk(KERN_CONT "empty\n");
4917
		else
4918 4919 4920 4921
			printk(KERN_CONT "[mem %0#10lx-%0#10lx]\n",
				arch_zone_lowest_possible_pfn[i] << PAGE_SHIFT,
				(arch_zone_highest_possible_pfn[i]
					<< PAGE_SHIFT) - 1);
M
Mel Gorman 已提交
4922 4923 4924
	}

	/* Print out the PFNs ZONE_MOVABLE begins at in each node */
4925
	printk("Movable zone start for each node\n");
M
Mel Gorman 已提交
4926 4927
	for (i = 0; i < MAX_NUMNODES; i++) {
		if (zone_movable_pfn[i])
4928 4929
			printk("  Node %d: %#010lx\n", i,
			       zone_movable_pfn[i] << PAGE_SHIFT);
M
Mel Gorman 已提交
4930
	}
4931

4932
	/* Print out the early node map */
4933
	printk("Early memory node ranges\n");
4934
	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
4935 4936
		printk("  node %3d: [mem %#010lx-%#010lx]\n", nid,
		       start_pfn << PAGE_SHIFT, (end_pfn << PAGE_SHIFT) - 1);
4937 4938

	/* Initialise every node */
4939
	mminit_verify_pageflags_layout();
4940
	setup_nr_node_ids();
4941 4942
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
4943
		free_area_init_node(nid, NULL,
4944
				find_min_pfn_for_node(nid), NULL);
4945 4946 4947 4948 4949

		/* Any memory on that node */
		if (pgdat->node_present_pages)
			node_set_state(nid, N_HIGH_MEMORY);
		check_for_regular_memory(pgdat);
4950 4951
	}
}
M
Mel Gorman 已提交
4952

4953
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
4954 4955 4956 4957 4958 4959
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
4960
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
4961

4962
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
4963 4964 4965 4966
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
4967

4968 4969 4970 4971 4972 4973 4974 4975 4976 4977 4978 4979 4980 4981 4982 4983 4984 4985
/*
 * 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
4986
early_param("kernelcore", cmdline_parse_kernelcore);
4987
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
4988

T
Tejun Heo 已提交
4989
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4990

4991
/**
4992 4993
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
4994 4995 4996 4997
 *
 * 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
4998 4999 5000
 * 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.
5001 5002 5003 5004 5005 5006
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

L
Linus Torvalds 已提交
5007 5008
void __init free_area_init(unsigned long *zones_size)
{
5009
	free_area_init_node(0, zones_size,
L
Linus Torvalds 已提交
5010 5011 5012 5013 5014 5015 5016 5017
			__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;

5018
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
5019
		lru_add_drain_cpu(cpu);
5020 5021 5022 5023 5024 5025 5026 5027
		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.
		 */
5028
		vm_events_fold_cpu(cpu);
5029 5030 5031 5032 5033 5034 5035 5036

		/*
		 * 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.
		 */
5037
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
5038 5039 5040 5041 5042 5043 5044 5045 5046
	}
	return NOTIFY_OK;
}

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

5047 5048 5049 5050 5051 5052 5053 5054
/*
 * 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;
5055
	enum zone_type i, j;
5056 5057 5058 5059 5060 5061 5062 5063 5064 5065 5066 5067

	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];
			}

5068 5069
			/* we treat the high watermark as reserved pages. */
			max += high_wmark_pages(zone);
5070 5071 5072 5073

			if (max > zone->present_pages)
				max = zone->present_pages;
			reserve_pages += max;
5074 5075 5076 5077 5078 5079 5080 5081 5082 5083
			/*
			 * Lowmem reserves are not available to
			 * GFP_HIGHUSER page cache allocations and
			 * kswapd tries to balance zones to their high
			 * watermark.  As a result, neither should be
			 * regarded as dirtyable memory, to prevent a
			 * situation where reclaim has to clean pages
			 * in order to balance the zones.
			 */
			zone->dirty_balance_reserve = max;
5084 5085
		}
	}
5086
	dirty_balance_reserve = reserve_pages;
5087 5088 5089
	totalreserve_pages = reserve_pages;
}

L
Linus Torvalds 已提交
5090 5091 5092 5093 5094 5095 5096 5097 5098
/*
 * 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;
5099
	enum zone_type j, idx;
L
Linus Torvalds 已提交
5100

5101
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
5102 5103 5104 5105 5106 5107
		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;

5108 5109
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
5110 5111
				struct zone *lower_zone;

5112 5113
				idx--;

L
Linus Torvalds 已提交
5114 5115 5116 5117 5118 5119 5120 5121 5122 5123
				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;
			}
		}
	}
5124 5125 5126

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
5127 5128
}

5129
static void __setup_per_zone_wmarks(void)
L
Linus Torvalds 已提交
5130 5131 5132 5133 5134 5135 5136 5137 5138 5139 5140 5141 5142
{
	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) {
5143 5144
		u64 tmp;

5145
		spin_lock_irqsave(&zone->lock, flags);
5146 5147
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
5148 5149
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
5150 5151 5152 5153
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
5154
			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
N
Nick Piggin 已提交
5155 5156
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
Linus Torvalds 已提交
5157 5158 5159 5160 5161 5162 5163 5164
			 */
			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;
5165
			zone->watermark[WMARK_MIN] = min_pages;
L
Linus Torvalds 已提交
5166
		} else {
N
Nick Piggin 已提交
5167 5168
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
5169 5170
			 * proportionate to the zone's size.
			 */
5171
			zone->watermark[WMARK_MIN] = tmp;
L
Linus Torvalds 已提交
5172 5173
		}

5174 5175
		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) + (tmp >> 2);
		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
5176 5177 5178 5179 5180

		zone->watermark[WMARK_MIN] += cma_wmark_pages(zone);
		zone->watermark[WMARK_LOW] += cma_wmark_pages(zone);
		zone->watermark[WMARK_HIGH] += cma_wmark_pages(zone);

5181
		setup_zone_migrate_reserve(zone);
5182
		spin_unlock_irqrestore(&zone->lock, flags);
L
Linus Torvalds 已提交
5183
	}
5184 5185 5186

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
5187 5188
}

5189 5190 5191 5192 5193 5194 5195 5196 5197 5198 5199 5200 5201 5202
/**
 * setup_per_zone_wmarks - called when min_free_kbytes changes
 * or when memory is hot-{added|removed}
 *
 * Ensures that the watermark[min,low,high] values for each zone are set
 * correctly with respect to min_free_kbytes.
 */
void setup_per_zone_wmarks(void)
{
	mutex_lock(&zonelists_mutex);
	__setup_per_zone_wmarks();
	mutex_unlock(&zonelists_mutex);
}

5203
/*
5204 5205 5206 5207 5208 5209 5210 5211 5212 5213 5214 5215 5216 5217 5218 5219 5220 5221 5222 5223
 * The inactive anon list should be small enough that the VM never has to
 * do too much work, but large enough that each inactive page has a chance
 * to be referenced again before it is swapped out.
 *
 * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
 * INACTIVE_ANON pages on this zone's LRU, maintained by the
 * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
 * the anonymous pages are kept on the inactive list.
 *
 * total     target    max
 * memory    ratio     inactive anon
 * -------------------------------------
 *   10MB       1         5MB
 *  100MB       1        50MB
 *    1GB       3       250MB
 *   10GB      10       0.9GB
 *  100GB      31         3GB
 *    1TB     101        10GB
 *   10TB     320        32GB
 */
5224
static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
5225
{
5226
	unsigned int gb, ratio;
5227

5228 5229 5230
	/* Zone size in gigabytes */
	gb = zone->present_pages >> (30 - PAGE_SHIFT);
	if (gb)
5231
		ratio = int_sqrt(10 * gb);
5232 5233
	else
		ratio = 1;
5234

5235 5236
	zone->inactive_ratio = ratio;
}
5237

5238
static void __meminit setup_per_zone_inactive_ratio(void)
5239 5240 5241 5242 5243
{
	struct zone *zone;

	for_each_zone(zone)
		calculate_zone_inactive_ratio(zone);
5244 5245
}

L
Linus Torvalds 已提交
5246 5247 5248 5249 5250 5251 5252 5253 5254 5255 5256 5257 5258 5259 5260 5261 5262 5263 5264 5265 5266 5267 5268 5269
/*
 * 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
 */
5270
int __meminit init_per_zone_wmark_min(void)
L
Linus Torvalds 已提交
5271 5272 5273 5274 5275 5276 5277 5278 5279 5280
{
	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;
5281
	setup_per_zone_wmarks();
5282
	refresh_zone_stat_thresholds();
L
Linus Torvalds 已提交
5283
	setup_per_zone_lowmem_reserve();
5284
	setup_per_zone_inactive_ratio();
L
Linus Torvalds 已提交
5285 5286
	return 0;
}
5287
module_init(init_per_zone_wmark_min)
L
Linus Torvalds 已提交
5288 5289 5290 5291 5292 5293 5294

/*
 * 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, 
5295
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
5296
{
5297
	proc_dointvec(table, write, buffer, length, ppos);
5298
	if (write)
5299
		setup_per_zone_wmarks();
L
Linus Torvalds 已提交
5300 5301 5302
	return 0;
}

5303 5304
#ifdef CONFIG_NUMA
int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
5305
	void __user *buffer, size_t *length, loff_t *ppos)
5306 5307 5308 5309
{
	struct zone *zone;
	int rc;

5310
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5311 5312 5313 5314
	if (rc)
		return rc;

	for_each_zone(zone)
5315
		zone->min_unmapped_pages = (zone->present_pages *
5316 5317 5318
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
5319 5320

int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
5321
	void __user *buffer, size_t *length, loff_t *ppos)
5322 5323 5324 5325
{
	struct zone *zone;
	int rc;

5326
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5327 5328 5329 5330 5331 5332 5333 5334
	if (rc)
		return rc;

	for_each_zone(zone)
		zone->min_slab_pages = (zone->present_pages *
				sysctl_min_slab_ratio) / 100;
	return 0;
}
5335 5336
#endif

L
Linus Torvalds 已提交
5337 5338 5339 5340 5341 5342
/*
 * 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
5343
 * minimum watermarks. The lowmem reserve ratio can only make sense
L
Linus Torvalds 已提交
5344 5345 5346
 * if in function of the boot time zone sizes.
 */
int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
5347
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
5348
{
5349
	proc_dointvec_minmax(table, write, buffer, length, ppos);
L
Linus Torvalds 已提交
5350 5351 5352 5353
	setup_per_zone_lowmem_reserve();
	return 0;
}

5354 5355 5356 5357 5358 5359 5360
/*
 * 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,
5361
	void __user *buffer, size_t *length, loff_t *ppos)
5362 5363 5364 5365 5366
{
	struct zone *zone;
	unsigned int cpu;
	int ret;

5367
	ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5368
	if (!write || (ret < 0))
5369
		return ret;
5370
	for_each_populated_zone(zone) {
5371
		for_each_possible_cpu(cpu) {
5372 5373
			unsigned long  high;
			high = zone->present_pages / percpu_pagelist_fraction;
5374 5375
			setup_pagelist_highmark(
				per_cpu_ptr(zone->pageset, cpu), high);
5376 5377 5378 5379 5380
		}
	}
	return 0;
}

5381
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
5382 5383 5384 5385 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395 5396 5397 5398 5399 5400 5401 5402 5403 5404 5405 5406

#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,
5407 5408
				     unsigned long low_limit,
				     unsigned long high_limit)
L
Linus Torvalds 已提交
5409
{
5410
	unsigned long long max = high_limit;
L
Linus Torvalds 已提交
5411 5412 5413 5414 5415 5416
	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
5417
		numentries = nr_kernel_pages;
L
Linus Torvalds 已提交
5418 5419 5420 5421 5422 5423 5424 5425 5426
		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);
5427 5428

		/* Make sure we've got at least a 0-order allocation.. */
5429 5430 5431 5432 5433 5434 5435 5436
		if (unlikely(flags & HASH_SMALL)) {
			/* Makes no sense without HASH_EARLY */
			WARN_ON(!(flags & HASH_EARLY));
			if (!(numentries >> *_hash_shift)) {
				numentries = 1UL << *_hash_shift;
				BUG_ON(!numentries);
			}
		} else if (unlikely((numentries * bucketsize) < PAGE_SIZE))
5437
			numentries = PAGE_SIZE / bucketsize;
L
Linus Torvalds 已提交
5438
	}
5439
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
5440 5441 5442 5443 5444 5445

	/* 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);
	}
5446
	max = min(max, 0x80000000ULL);
L
Linus Torvalds 已提交
5447

5448 5449
	if (numentries < low_limit)
		numentries = low_limit;
L
Linus Torvalds 已提交
5450 5451 5452
	if (numentries > max)
		numentries = max;

5453
	log2qty = ilog2(numentries);
L
Linus Torvalds 已提交
5454 5455 5456 5457

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
5458
			table = alloc_bootmem_nopanic(size);
L
Linus Torvalds 已提交
5459 5460 5461
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
5462 5463
			/*
			 * If bucketsize is not a power-of-two, we may free
5464 5465
			 * some pages at the end of hash table which
			 * alloc_pages_exact() automatically does
5466
			 */
5467
			if (get_order(size) < MAX_ORDER) {
5468
				table = alloc_pages_exact(size, GFP_ATOMIC);
5469 5470
				kmemleak_alloc(table, size, 1, GFP_ATOMIC);
			}
L
Linus Torvalds 已提交
5471 5472 5473 5474 5475 5476
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

5477
	printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
L
Linus Torvalds 已提交
5478
	       tablename,
5479
	       (1UL << log2qty),
5480
	       ilog2(size) - PAGE_SHIFT,
L
Linus Torvalds 已提交
5481 5482 5483 5484 5485 5486 5487 5488 5489
	       size);

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

	return table;
}
5490

5491 5492 5493 5494 5495 5496 5497 5498 5499 5500 5501 5502 5503 5504 5505
/* 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);
5506
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5507 5508
#else
	pfn = pfn - zone->zone_start_pfn;
5509
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5510 5511 5512 5513
#endif /* CONFIG_SPARSEMEM */
}

/**
5514
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5515 5516 5517 5518 5519 5520 5521 5522 5523 5524 5525 5526 5527 5528 5529 5530 5531 5532 5533 5534 5535 5536
 * @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;
5537

5538 5539 5540 5541
	return flags;
}

/**
5542
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5543 5544 5545 5546 5547 5548 5549 5550 5551 5552 5553 5554 5555 5556 5557 5558 5559
 * @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);
5560 5561
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
5562 5563 5564 5565 5566 5567 5568

	for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1)
		if (flags & value)
			__set_bit(bitidx + start_bitidx, bitmap);
		else
			__clear_bit(bitidx + start_bitidx, bitmap);
}
K
KAMEZAWA Hiroyuki 已提交
5569 5570

/*
5571 5572 5573 5574 5575 5576
 * This function checks whether pageblock includes unmovable pages or not.
 * If @count is not zero, it is okay to include less @count unmovable pages
 *
 * PageLRU check wihtout isolation or lru_lock could race so that
 * MIGRATE_MOVABLE block might include unmovable pages. It means you can't
 * expect this function should be exact.
K
KAMEZAWA Hiroyuki 已提交
5577
 */
5578
bool has_unmovable_pages(struct zone *zone, struct page *page, int count)
5579 5580
{
	unsigned long pfn, iter, found;
5581 5582
	int mt;

5583 5584
	/*
	 * For avoiding noise data, lru_add_drain_all() should be called
5585
	 * If ZONE_MOVABLE, the zone never contains unmovable pages
5586 5587
	 */
	if (zone_idx(zone) == ZONE_MOVABLE)
5588
		return false;
5589 5590
	mt = get_pageblock_migratetype(page);
	if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
5591
		return false;
5592 5593 5594 5595 5596

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

5597
		if (!pfn_valid_within(check))
5598
			continue;
5599

5600
		page = pfn_to_page(check);
5601 5602 5603 5604 5605 5606 5607
		/*
		 * We can't use page_count without pin a page
		 * because another CPU can free compound page.
		 * This check already skips compound tails of THP
		 * because their page->_count is zero at all time.
		 */
		if (!atomic_read(&page->_count)) {
5608 5609 5610 5611
			if (PageBuddy(page))
				iter += (1 << page_order(page)) - 1;
			continue;
		}
5612

5613 5614 5615 5616 5617 5618 5619 5620 5621 5622 5623 5624 5625 5626 5627 5628
		if (!PageLRU(page))
			found++;
		/*
		 * If there are RECLAIMABLE pages, we need to check it.
		 * But now, memory offline itself doesn't call shrink_slab()
		 * and it still to be fixed.
		 */
		/*
		 * If the page is not RAM, page_count()should be 0.
		 * we don't need more check. This is an _used_ not-movable page.
		 *
		 * The problematic thing here is PG_reserved pages. PG_reserved
		 * is set to both of a memory hole page and a _used_ kernel
		 * page at boot.
		 */
		if (found > count)
5629
			return true;
5630
	}
5631
	return false;
5632 5633 5634 5635
}

bool is_pageblock_removable_nolock(struct page *page)
{
5636 5637
	struct zone *zone;
	unsigned long pfn;
5638 5639 5640 5641 5642

	/*
	 * We have to be careful here because we are iterating over memory
	 * sections which are not zone aware so we might end up outside of
	 * the zone but still within the section.
5643 5644
	 * We have to take care about the node as well. If the node is offline
	 * its NODE_DATA will be NULL - see page_zone.
5645
	 */
5646 5647 5648 5649 5650 5651
	if (!node_online(page_to_nid(page)))
		return false;

	zone = page_zone(page);
	pfn = page_to_pfn(page);
	if (zone->zone_start_pfn > pfn ||
5652 5653 5654
			zone->zone_start_pfn + zone->spanned_pages <= pfn)
		return false;

5655
	return !has_unmovable_pages(zone, page, 0);
K
KAMEZAWA Hiroyuki 已提交
5656
}
K
KAMEZAWA Hiroyuki 已提交
5657

5658 5659 5660 5661 5662 5663 5664 5665 5666 5667 5668 5669 5670 5671 5672
#ifdef CONFIG_CMA

static unsigned long pfn_max_align_down(unsigned long pfn)
{
	return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
			     pageblock_nr_pages) - 1);
}

static unsigned long pfn_max_align_up(unsigned long pfn)
{
	return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
				pageblock_nr_pages));
}

/* [start, end) must belong to a single zone. */
5673 5674
static int __alloc_contig_migrate_range(struct compact_control *cc,
					unsigned long start, unsigned long end)
5675 5676
{
	/* This function is based on compact_zone() from compaction.c. */
5677
	unsigned long nr_reclaimed;
5678 5679 5680 5681 5682 5683
	unsigned long pfn = start;
	unsigned int tries = 0;
	int ret = 0;

	migrate_prep_local();

5684
	while (pfn < end || !list_empty(&cc->migratepages)) {
5685 5686 5687 5688 5689
		if (fatal_signal_pending(current)) {
			ret = -EINTR;
			break;
		}

5690 5691 5692
		if (list_empty(&cc->migratepages)) {
			cc->nr_migratepages = 0;
			pfn = isolate_migratepages_range(cc->zone, cc,
M
Minchan Kim 已提交
5693
							 pfn, end, true);
5694 5695 5696 5697 5698 5699 5700 5701 5702 5703
			if (!pfn) {
				ret = -EINTR;
				break;
			}
			tries = 0;
		} else if (++tries == 5) {
			ret = ret < 0 ? ret : -EBUSY;
			break;
		}

5704 5705 5706
		nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
							&cc->migratepages);
		cc->nr_migratepages -= nr_reclaimed;
5707

5708
		ret = migrate_pages(&cc->migratepages,
5709
				    alloc_migrate_target,
M
Minchan Kim 已提交
5710
				    0, false, MIGRATE_SYNC);
5711 5712
	}

5713
	putback_lru_pages(&cc->migratepages);
5714 5715 5716
	return ret > 0 ? 0 : ret;
}

5717 5718 5719 5720 5721 5722 5723 5724 5725 5726 5727 5728 5729 5730 5731 5732 5733 5734 5735 5736 5737 5738 5739 5740 5741 5742 5743 5744 5745 5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 5756 5757 5758 5759 5760 5761 5762 5763 5764
/*
 * Update zone's cma pages counter used for watermark level calculation.
 */
static inline void __update_cma_watermarks(struct zone *zone, int count)
{
	unsigned long flags;
	spin_lock_irqsave(&zone->lock, flags);
	zone->min_cma_pages += count;
	spin_unlock_irqrestore(&zone->lock, flags);
	setup_per_zone_wmarks();
}

/*
 * Trigger memory pressure bump to reclaim some pages in order to be able to
 * allocate 'count' pages in single page units. Does similar work as
 *__alloc_pages_slowpath() function.
 */
static int __reclaim_pages(struct zone *zone, gfp_t gfp_mask, int count)
{
	enum zone_type high_zoneidx = gfp_zone(gfp_mask);
	struct zonelist *zonelist = node_zonelist(0, gfp_mask);
	int did_some_progress = 0;
	int order = 1;

	/*
	 * Increase level of watermarks to force kswapd do his job
	 * to stabilise at new watermark level.
	 */
	__update_cma_watermarks(zone, count);

	/* Obey watermarks as if the page was being allocated */
	while (!zone_watermark_ok(zone, 0, low_wmark_pages(zone), 0, 0)) {
		wake_all_kswapd(order, zonelist, high_zoneidx, zone_idx(zone));

		did_some_progress = __perform_reclaim(gfp_mask, order, zonelist,
						      NULL);
		if (!did_some_progress) {
			/* Exhausted what can be done so it's blamo time */
			out_of_memory(zonelist, gfp_mask, order, NULL, false);
		}
	}

	/* Restore original watermark levels. */
	__update_cma_watermarks(zone, -count);

	return count;
}

5765 5766 5767 5768
/**
 * alloc_contig_range() -- tries to allocate given range of pages
 * @start:	start PFN to allocate
 * @end:	one-past-the-last PFN to allocate
5769 5770 5771 5772
 * @migratetype:	migratetype of the underlaying pageblocks (either
 *			#MIGRATE_MOVABLE or #MIGRATE_CMA).  All pageblocks
 *			in range must have the same migratetype and it must
 *			be either of the two.
5773 5774 5775 5776 5777 5778 5779 5780 5781 5782 5783 5784
 *
 * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
 * aligned, however it's the caller's responsibility to guarantee that
 * we are the only thread that changes migrate type of pageblocks the
 * pages fall in.
 *
 * The PFN range must belong to a single zone.
 *
 * Returns zero on success or negative error code.  On success all
 * pages which PFN is in [start, end) are allocated for the caller and
 * need to be freed with free_contig_range().
 */
5785 5786
int alloc_contig_range(unsigned long start, unsigned long end,
		       unsigned migratetype)
5787 5788 5789 5790 5791
{
	struct zone *zone = page_zone(pfn_to_page(start));
	unsigned long outer_start, outer_end;
	int ret = 0, order;

5792 5793 5794 5795 5796 5797 5798 5799 5800
	struct compact_control cc = {
		.nr_migratepages = 0,
		.order = -1,
		.zone = page_zone(pfn_to_page(start)),
		.sync = true,
		.ignore_skip_hint = true,
	};
	INIT_LIST_HEAD(&cc.migratepages);

5801 5802 5803 5804 5805 5806 5807 5808 5809 5810 5811 5812 5813 5814 5815 5816 5817 5818 5819 5820 5821 5822 5823 5824 5825
	/*
	 * What we do here is we mark all pageblocks in range as
	 * MIGRATE_ISOLATE.  Because pageblock and max order pages may
	 * have different sizes, and due to the way page allocator
	 * work, we align the range to biggest of the two pages so
	 * that page allocator won't try to merge buddies from
	 * different pageblocks and change MIGRATE_ISOLATE to some
	 * other migration type.
	 *
	 * Once the pageblocks are marked as MIGRATE_ISOLATE, we
	 * migrate the pages from an unaligned range (ie. pages that
	 * we are interested in).  This will put all the pages in
	 * range back to page allocator as MIGRATE_ISOLATE.
	 *
	 * When this is done, we take the pages in range from page
	 * allocator removing them from the buddy system.  This way
	 * page allocator will never consider using them.
	 *
	 * This lets us mark the pageblocks back as
	 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
	 * aligned range but not in the unaligned, original range are
	 * put back to page allocator so that buddy can use them.
	 */

	ret = start_isolate_page_range(pfn_max_align_down(start),
5826
				       pfn_max_align_up(end), migratetype);
5827
	if (ret)
5828
		return ret;
5829

5830
	ret = __alloc_contig_migrate_range(&cc, start, end);
5831 5832 5833 5834 5835 5836 5837 5838 5839 5840 5841 5842 5843 5844 5845 5846 5847 5848 5849 5850 5851 5852 5853 5854 5855 5856 5857 5858 5859 5860 5861 5862 5863 5864 5865 5866 5867 5868 5869 5870 5871
	if (ret)
		goto done;

	/*
	 * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
	 * aligned blocks that are marked as MIGRATE_ISOLATE.  What's
	 * more, all pages in [start, end) are free in page allocator.
	 * What we are going to do is to allocate all pages from
	 * [start, end) (that is remove them from page allocator).
	 *
	 * The only problem is that pages at the beginning and at the
	 * end of interesting range may be not aligned with pages that
	 * page allocator holds, ie. they can be part of higher order
	 * pages.  Because of this, we reserve the bigger range and
	 * once this is done free the pages we are not interested in.
	 *
	 * We don't have to hold zone->lock here because the pages are
	 * isolated thus they won't get removed from buddy.
	 */

	lru_add_drain_all();
	drain_all_pages();

	order = 0;
	outer_start = start;
	while (!PageBuddy(pfn_to_page(outer_start))) {
		if (++order >= MAX_ORDER) {
			ret = -EBUSY;
			goto done;
		}
		outer_start &= ~0UL << order;
	}

	/* Make sure the range is really isolated. */
	if (test_pages_isolated(outer_start, end)) {
		pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
		       outer_start, end);
		ret = -EBUSY;
		goto done;
	}

5872 5873 5874 5875 5876 5877 5878
	/*
	 * Reclaim enough pages to make sure that contiguous allocation
	 * will not starve the system.
	 */
	__reclaim_pages(zone, GFP_HIGHUSER_MOVABLE, end-start);

	/* Grab isolated pages from freelists. */
5879
	outer_end = isolate_freepages_range(&cc, outer_start, end);
5880 5881 5882 5883 5884 5885 5886 5887 5888 5889 5890 5891 5892
	if (!outer_end) {
		ret = -EBUSY;
		goto done;
	}

	/* Free head and tail (if any) */
	if (start != outer_start)
		free_contig_range(outer_start, start - outer_start);
	if (end != outer_end)
		free_contig_range(end, outer_end - end);

done:
	undo_isolate_page_range(pfn_max_align_down(start),
5893
				pfn_max_align_up(end), migratetype);
5894 5895 5896 5897 5898 5899 5900 5901 5902 5903
	return ret;
}

void free_contig_range(unsigned long pfn, unsigned nr_pages)
{
	for (; nr_pages--; ++pfn)
		__free_page(pfn_to_page(pfn));
}
#endif

5904 5905 5906 5907 5908 5909 5910 5911 5912 5913 5914 5915 5916 5917 5918 5919 5920
#ifdef CONFIG_MEMORY_HOTPLUG
static int __meminit __zone_pcp_update(void *data)
{
	struct zone *zone = data;
	int cpu;
	unsigned long batch = zone_batchsize(zone), flags;

	for_each_possible_cpu(cpu) {
		struct per_cpu_pageset *pset;
		struct per_cpu_pages *pcp;

		pset = per_cpu_ptr(zone->pageset, cpu);
		pcp = &pset->pcp;

		local_irq_save(flags);
		if (pcp->count > 0)
			free_pcppages_bulk(zone, pcp->count, pcp);
5921
		drain_zonestat(zone, pset);
5922 5923 5924 5925 5926 5927 5928 5929 5930 5931 5932 5933
		setup_pageset(pset, batch);
		local_irq_restore(flags);
	}
	return 0;
}

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

K
KAMEZAWA Hiroyuki 已提交
5934
#ifdef CONFIG_MEMORY_HOTREMOVE
5935 5936 5937
void zone_pcp_reset(struct zone *zone)
{
	unsigned long flags;
5938 5939
	int cpu;
	struct per_cpu_pageset *pset;
5940 5941 5942 5943

	/* avoid races with drain_pages()  */
	local_irq_save(flags);
	if (zone->pageset != &boot_pageset) {
5944 5945 5946 5947
		for_each_online_cpu(cpu) {
			pset = per_cpu_ptr(zone->pageset, cpu);
			drain_zonestat(zone, pset);
		}
5948 5949 5950 5951 5952 5953
		free_percpu(zone->pageset);
		zone->pageset = &boot_pageset;
	}
	local_irq_restore(flags);
}

K
KAMEZAWA Hiroyuki 已提交
5954 5955 5956 5957 5958 5959 5960 5961 5962 5963 5964 5965 5966 5967 5968 5969 5970 5971 5972 5973 5974 5975 5976 5977 5978 5979 5980 5981 5982 5983 5984 5985 5986 5987 5988 5989 5990 5991 5992 5993 5994 5995 5996 5997 5998
/*
 * 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
5999 6000 6001 6002 6003 6004 6005 6006 6007 6008 6009 6010 6011 6012 6013 6014 6015 6016 6017 6018 6019

#ifdef CONFIG_MEMORY_FAILURE
bool is_free_buddy_page(struct page *page)
{
	struct zone *zone = page_zone(page);
	unsigned long pfn = page_to_pfn(page);
	unsigned long flags;
	int order;

	spin_lock_irqsave(&zone->lock, flags);
	for (order = 0; order < MAX_ORDER; order++) {
		struct page *page_head = page - (pfn & ((1 << order) - 1));

		if (PageBuddy(page_head) && page_order(page_head) >= order)
			break;
	}
	spin_unlock_irqrestore(&zone->lock, flags);

	return order < MAX_ORDER;
}
#endif
6020

A
Andrew Morton 已提交
6021
static const struct trace_print_flags pageflag_names[] = {
6022 6023 6024 6025 6026 6027 6028 6029 6030 6031 6032 6033 6034 6035 6036 6037 6038 6039 6040 6041 6042 6043 6044 6045 6046 6047 6048 6049 6050 6051 6052 6053 6054
	{1UL << PG_locked,		"locked"	},
	{1UL << PG_error,		"error"		},
	{1UL << PG_referenced,		"referenced"	},
	{1UL << PG_uptodate,		"uptodate"	},
	{1UL << PG_dirty,		"dirty"		},
	{1UL << PG_lru,			"lru"		},
	{1UL << PG_active,		"active"	},
	{1UL << PG_slab,		"slab"		},
	{1UL << PG_owner_priv_1,	"owner_priv_1"	},
	{1UL << PG_arch_1,		"arch_1"	},
	{1UL << PG_reserved,		"reserved"	},
	{1UL << PG_private,		"private"	},
	{1UL << PG_private_2,		"private_2"	},
	{1UL << PG_writeback,		"writeback"	},
#ifdef CONFIG_PAGEFLAGS_EXTENDED
	{1UL << PG_head,		"head"		},
	{1UL << PG_tail,		"tail"		},
#else
	{1UL << PG_compound,		"compound"	},
#endif
	{1UL << PG_swapcache,		"swapcache"	},
	{1UL << PG_mappedtodisk,	"mappedtodisk"	},
	{1UL << PG_reclaim,		"reclaim"	},
	{1UL << PG_swapbacked,		"swapbacked"	},
	{1UL << PG_unevictable,		"unevictable"	},
#ifdef CONFIG_MMU
	{1UL << PG_mlocked,		"mlocked"	},
#endif
#ifdef CONFIG_ARCH_USES_PG_UNCACHED
	{1UL << PG_uncached,		"uncached"	},
#endif
#ifdef CONFIG_MEMORY_FAILURE
	{1UL << PG_hwpoison,		"hwpoison"	},
6055 6056 6057
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
	{1UL << PG_compound_lock,	"compound_lock"	},
6058 6059 6060 6061 6062 6063 6064 6065 6066
#endif
};

static void dump_page_flags(unsigned long flags)
{
	const char *delim = "";
	unsigned long mask;
	int i;

A
Andrew Morton 已提交
6067
	BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS);
6068

6069 6070 6071 6072 6073
	printk(KERN_ALERT "page flags: %#lx(", flags);

	/* remove zone id */
	flags &= (1UL << NR_PAGEFLAGS) - 1;

A
Andrew Morton 已提交
6074
	for (i = 0; i < ARRAY_SIZE(pageflag_names) && flags; i++) {
6075 6076 6077 6078 6079 6080 6081 6082 6083 6084 6085 6086 6087 6088 6089 6090 6091 6092 6093 6094 6095

		mask = pageflag_names[i].mask;
		if ((flags & mask) != mask)
			continue;

		flags &= ~mask;
		printk("%s%s", delim, pageflag_names[i].name);
		delim = "|";
	}

	/* check for left over flags */
	if (flags)
		printk("%s%#lx", delim, flags);

	printk(")\n");
}

void dump_page(struct page *page)
{
	printk(KERN_ALERT
	       "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
6096
		page, atomic_read(&page->_count), page_mapcount(page),
6097 6098
		page->mapping, page->index);
	dump_page_flags(page->flags);
6099
	mem_cgroup_print_bad_page(page);
6100
}