page_alloc.c 169.6 KB
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/*
 *  linux/mm/page_alloc.c
 *
 *  Manages the free list, the system allocates free pages here.
 *  Note that kmalloc() lives in slab.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *  Swap reorganised 29.12.95, Stephen Tweedie
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *  Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
 *  Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
 *  Zone balancing, Kanoj Sarcar, SGI, Jan 2000
 *  Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
 *          (lots of bits borrowed from Ingo Molnar & Andrew Morton)
 */

#include <linux/stddef.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/interrupt.h>
#include <linux/pagemap.h>
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#include <linux/jiffies.h>
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#include <linux/bootmem.h>
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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 } },
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#endif
#ifdef CONFIG_MOVABLE_NODE
	[N_MEMORY] = { { [0] = 1UL } },
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#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)) {
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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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 *
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 * -- nyc
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 */

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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);
		}
570
		combined_idx = buddy_idx & page_idx;
L
Linus Torvalds 已提交
571 572 573 574 575
		page = page + (combined_idx - page_idx);
		page_idx = combined_idx;
		order++;
	}
	set_page_order(page, order);
576 577 578 579 580 581 582 583 584

	/*
	 * 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
	 */
585
	if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
586
		struct page *higher_page, *higher_buddy;
587 588 589
		combined_idx = buddy_idx & page_idx;
		higher_page = page + (combined_idx - page_idx);
		buddy_idx = __find_buddy_index(combined_idx, order + 1);
590
		higher_buddy = higher_page + (buddy_idx - combined_idx);
591 592 593 594 595 596 597 598 599
		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
600 601 602
	zone->free_area[order].nr_free++;
}

N
Nick Piggin 已提交
603
static inline int free_pages_check(struct page *page)
L
Linus Torvalds 已提交
604
{
N
Nick Piggin 已提交
605 606
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
607
		(atomic_read(&page->_count) != 0) |
608 609
		(page->flags & PAGE_FLAGS_CHECK_AT_FREE) |
		(mem_cgroup_bad_page_check(page)))) {
N
Nick Piggin 已提交
610
		bad_page(page);
611
		return 1;
612
	}
613
	reset_page_last_nid(page);
614 615 616
	if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
		page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
	return 0;
L
Linus Torvalds 已提交
617 618 619
}

/*
620
 * Frees a number of pages from the PCP lists
L
Linus Torvalds 已提交
621
 * Assumes all pages on list are in same zone, and of same order.
622
 * count is the number of pages to free.
L
Linus Torvalds 已提交
623 624 625 626 627 628 629
 *
 * 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.
 */
630 631
static void free_pcppages_bulk(struct zone *zone, int count,
					struct per_cpu_pages *pcp)
L
Linus Torvalds 已提交
632
{
633
	int migratetype = 0;
634
	int batch_free = 0;
635
	int to_free = count;
636

N
Nick Piggin 已提交
637
	spin_lock(&zone->lock);
638
	zone->all_unreclaimable = 0;
L
Linus Torvalds 已提交
639
	zone->pages_scanned = 0;
640

641
	while (to_free) {
N
Nick Piggin 已提交
642
		struct page *page;
643 644 645
		struct list_head *list;

		/*
646 647 648 649 650
		 * 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
651 652
		 */
		do {
653
			batch_free++;
654 655 656 657
			if (++migratetype == MIGRATE_PCPTYPES)
				migratetype = 0;
			list = &pcp->lists[migratetype];
		} while (list_empty(list));
N
Nick Piggin 已提交
658

659 660 661 662
		/* This is the only non-empty list. Free them all. */
		if (batch_free == MIGRATE_PCPTYPES)
			batch_free = to_free;

663
		do {
664 665
			int mt;	/* migratetype of the to-be-freed page */

666 667 668
			page = list_entry(list->prev, struct page, lru);
			/* must delete as __free_one_page list manipulates */
			list_del(&page->lru);
669
			mt = get_freepage_migratetype(page);
670
			/* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
671 672
			__free_one_page(page, zone, 0, mt);
			trace_mm_page_pcpu_drain(page, 0, mt);
673 674 675 676 677
			if (likely(get_pageblock_migratetype(page) != MIGRATE_ISOLATE)) {
				__mod_zone_page_state(zone, NR_FREE_PAGES, 1);
				if (is_migrate_cma(mt))
					__mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1);
			}
678
		} while (--to_free && --batch_free && !list_empty(list));
L
Linus Torvalds 已提交
679
	}
N
Nick Piggin 已提交
680
	spin_unlock(&zone->lock);
L
Linus Torvalds 已提交
681 682
}

683 684
static void free_one_page(struct zone *zone, struct page *page, int order,
				int migratetype)
L
Linus Torvalds 已提交
685
{
686
	spin_lock(&zone->lock);
687
	zone->all_unreclaimable = 0;
688
	zone->pages_scanned = 0;
689

690
	__free_one_page(page, zone, order, migratetype);
691
	if (unlikely(migratetype != MIGRATE_ISOLATE))
692
		__mod_zone_freepage_state(zone, 1 << order, migratetype);
693
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
694 695
}

696
static bool free_pages_prepare(struct page *page, unsigned int order)
N
Nick Piggin 已提交
697
{
L
Linus Torvalds 已提交
698
	int i;
699
	int bad = 0;
L
Linus Torvalds 已提交
700

701
	trace_mm_page_free(page, order);
702 703
	kmemcheck_free_shadow(page, order);

A
Andrea Arcangeli 已提交
704 705 706 707
	if (PageAnon(page))
		page->mapping = NULL;
	for (i = 0; i < (1 << order); i++)
		bad += free_pages_check(page + i);
708
	if (bad)
709
		return false;
710

711
	if (!PageHighMem(page)) {
N
Nick Piggin 已提交
712
		debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
713 714 715
		debug_check_no_obj_freed(page_address(page),
					   PAGE_SIZE << order);
	}
N
Nick Piggin 已提交
716
	arch_free_page(page, order);
N
Nick Piggin 已提交
717
	kernel_map_pages(page, 1 << order, 0);
N
Nick Piggin 已提交
718

719 720 721 722 723 724
	return true;
}

static void __free_pages_ok(struct page *page, unsigned int order)
{
	unsigned long flags;
M
Minchan Kim 已提交
725
	int migratetype;
726 727 728 729

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

N
Nick Piggin 已提交
730
	local_irq_save(flags);
731
	__count_vm_events(PGFREE, 1 << order);
M
Minchan Kim 已提交
732 733 734
	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
735
	local_irq_restore(flags);
L
Linus Torvalds 已提交
736 737
}

738 739 740 741 742 743 744
/*
 * Read access to zone->managed_pages is safe because it's unsigned long,
 * but we still need to serialize writers. Currently all callers of
 * __free_pages_bootmem() except put_page_bootmem() should only be used
 * at boot time. So for shorter boot time, we shift the burden to
 * put_page_bootmem() to serialize writers.
 */
745
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
746
{
747 748
	unsigned int nr_pages = 1 << order;
	unsigned int loop;
749

750 751 752 753 754 755 756 757
	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);
758
	}
759

760
	page_zone(page)->managed_pages += 1 << order;
761 762
	set_page_refcounted(page);
	__free_pages(page, order);
763 764
}

765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782
#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
783 784 785 786 787 788 789 790 791 792 793 794 795

/*
 * 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.
 *
796
 * -- nyc
L
Linus Torvalds 已提交
797
 */
N
Nick Piggin 已提交
798
static inline void expand(struct zone *zone, struct page *page,
799 800
	int low, int high, struct free_area *area,
	int migratetype)
L
Linus Torvalds 已提交
801 802 803 804 805 806 807
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
808
		VM_BUG_ON(bad_range(zone, &page[size]));
809 810 811 812 813 814 815 816 817 818 819 820 821

#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 */
822 823
			__mod_zone_freepage_state(zone, -(1 << high),
						  migratetype);
824 825 826
			continue;
		}
#endif
827
		list_add(&page[size].lru, &area->free_list[migratetype]);
L
Linus Torvalds 已提交
828 829 830 831 832 833 834 835
		area->nr_free++;
		set_page_order(&page[size], high);
	}
}

/*
 * This page is about to be returned from the page allocator
 */
836
static inline int check_new_page(struct page *page)
L
Linus Torvalds 已提交
837
{
N
Nick Piggin 已提交
838 839
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
840
		(atomic_read(&page->_count) != 0)  |
841 842
		(page->flags & PAGE_FLAGS_CHECK_AT_PREP) |
		(mem_cgroup_bad_page_check(page)))) {
N
Nick Piggin 已提交
843
		bad_page(page);
844
		return 1;
845
	}
846 847 848 849 850 851 852 853 854 855 856 857
	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;
	}
858

H
Hugh Dickins 已提交
859
	set_page_private(page, 0);
860
	set_page_refcounted(page);
N
Nick Piggin 已提交
861 862

	arch_alloc_page(page, order);
L
Linus Torvalds 已提交
863
	kernel_map_pages(page, 1 << order, 1);
N
Nick Piggin 已提交
864 865 866 867 868 869 870

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

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

871
	return 0;
L
Linus Torvalds 已提交
872 873
}

874 875 876 877
/*
 * Go through the free lists for the given migratetype and remove
 * the smallest available page from the freelists
 */
878 879
static inline
struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904
						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;
}


905 906 907 908
/*
 * This array describes the order lists are fallen back to when
 * the free lists for the desirable migrate type are depleted
 */
909 910 911 912 913 914 915 916 917
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
918 919
	[MIGRATE_RESERVE]     = { MIGRATE_RESERVE }, /* Never used */
	[MIGRATE_ISOLATE]     = { MIGRATE_RESERVE }, /* Never used */
920 921
};

922 923
/*
 * Move the free pages in a range to the free lists of the requested type.
924
 * Note that start_page and end_pages are not aligned on a pageblock
925 926
 * boundary. If alignment is required, use move_freepages_block()
 */
927
int move_freepages(struct zone *zone,
A
Adrian Bunk 已提交
928 929
			  struct page *start_page, struct page *end_page,
			  int migratetype)
930 931 932
{
	struct page *page;
	unsigned long order;
933
	int pages_moved = 0;
934 935 936 937 938 939 940

#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
941
	 * grouping pages by mobility
942 943 944 945 946
	 */
	BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif

	for (page = start_page; page <= end_page;) {
947 948 949
		/* Make sure we are not inadvertently changing nodes */
		VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));

950 951 952 953 954 955 956 957 958 959 960
		if (!pfn_valid_within(page_to_pfn(page))) {
			page++;
			continue;
		}

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

		order = page_order(page);
961 962
		list_move(&page->lru,
			  &zone->free_area[order].free_list[migratetype]);
M
Minchan Kim 已提交
963
		set_freepage_migratetype(page, migratetype);
964
		page += 1 << order;
965
		pages_moved += 1 << order;
966 967
	}

968
	return pages_moved;
969 970
}

971
int move_freepages_block(struct zone *zone, struct page *page,
972
				int migratetype)
973 974 975 976 977
{
	unsigned long start_pfn, end_pfn;
	struct page *start_page, *end_page;

	start_pfn = page_to_pfn(page);
978
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
979
	start_page = pfn_to_page(start_pfn);
980 981
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
982 983 984 985 986 987 988 989 990 991

	/* 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);
}

992 993 994 995 996 997 998 999 1000 1001 1002
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;
	}
}

1003
/* Remove an element from the buddy allocator from the fallback list */
1004 1005
static inline struct page *
__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
1006 1007 1008 1009 1010 1011 1012 1013 1014
{
	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) {
1015
		for (i = 0;; i++) {
1016 1017
			migratetype = fallbacks[start_migratetype][i];

1018 1019
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
1020
				break;
M
Mel Gorman 已提交
1021

1022 1023 1024 1025 1026 1027 1028 1029 1030
			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--;

			/*
1031
			 * If breaking a large block of pages, move all free
1032 1033
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
L
Lucas De Marchi 已提交
1034
			 * aggressive about taking ownership of free pages
1035 1036 1037 1038 1039 1040
			 *
			 * 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.
1041
			 */
1042 1043 1044 1045 1046
			if (!is_migrate_cma(migratetype) &&
			    (unlikely(current_order >= pageblock_order / 2) ||
			     start_migratetype == MIGRATE_RECLAIMABLE ||
			     page_group_by_mobility_disabled)) {
				int pages;
1047 1048 1049 1050
				pages = move_freepages_block(zone, page,
								start_migratetype);

				/* Claim the whole block if over half of it is free */
1051 1052
				if (pages >= (1 << (pageblock_order-1)) ||
						page_group_by_mobility_disabled)
1053 1054 1055
					set_pageblock_migratetype(page,
								start_migratetype);

1056
				migratetype = start_migratetype;
1057
			}
1058 1059 1060 1061 1062

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

1063
			/* Take ownership for orders >= pageblock_order */
1064 1065
			if (current_order >= pageblock_order &&
			    !is_migrate_cma(migratetype))
1066
				change_pageblock_range(page, current_order,
1067 1068
							start_migratetype);

1069 1070 1071
			expand(zone, page, order, current_order, area,
			       is_migrate_cma(migratetype)
			     ? migratetype : start_migratetype);
1072 1073 1074 1075

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

1076 1077 1078 1079
			return page;
		}
	}

1080
	return NULL;
1081 1082
}

1083
/*
L
Linus Torvalds 已提交
1084 1085 1086
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
1087 1088
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
L
Linus Torvalds 已提交
1089 1090 1091
{
	struct page *page;

1092
retry_reserve:
1093
	page = __rmqueue_smallest(zone, order, migratetype);
1094

1095
	if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1096
		page = __rmqueue_fallback(zone, order, migratetype);
1097

1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108
		/*
		 * 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;
		}
	}

1109
	trace_mm_page_alloc_zone_locked(page, order, migratetype);
1110
	return page;
L
Linus Torvalds 已提交
1111 1112
}

1113
/*
L
Linus Torvalds 已提交
1114 1115 1116 1117
 * 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.
 */
1118
static int rmqueue_bulk(struct zone *zone, unsigned int order,
1119
			unsigned long count, struct list_head *list,
1120
			int migratetype, int cold)
L
Linus Torvalds 已提交
1121
{
1122
	int mt = migratetype, i;
1123

N
Nick Piggin 已提交
1124
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
1125
	for (i = 0; i < count; ++i) {
1126
		struct page *page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1127
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
1128
			break;
1129 1130 1131 1132 1133 1134 1135 1136 1137 1138

		/*
		 * 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.
		 */
1139 1140 1141 1142
		if (likely(cold == 0))
			list_add(&page->lru, list);
		else
			list_add_tail(&page->lru, list);
1143 1144 1145 1146 1147
		if (IS_ENABLED(CONFIG_CMA)) {
			mt = get_pageblock_migratetype(page);
			if (!is_migrate_cma(mt) && mt != MIGRATE_ISOLATE)
				mt = migratetype;
		}
1148
		set_freepage_migratetype(page, mt);
1149
		list = &page->lru;
1150 1151 1152
		if (is_migrate_cma(mt))
			__mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
					      -(1 << order));
L
Linus Torvalds 已提交
1153
	}
1154
	__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
N
Nick Piggin 已提交
1155
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
1156
	return i;
L
Linus Torvalds 已提交
1157 1158
}

1159
#ifdef CONFIG_NUMA
1160
/*
1161 1162 1163 1164
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
1165 1166
 * Note that this function must be called with the thread pinned to
 * a single processor.
1167
 */
1168
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1169 1170
{
	unsigned long flags;
1171
	int to_drain;
1172

1173 1174 1175 1176 1177
	local_irq_save(flags);
	if (pcp->count >= pcp->batch)
		to_drain = pcp->batch;
	else
		to_drain = pcp->count;
1178 1179 1180 1181
	if (to_drain > 0) {
		free_pcppages_bulk(zone, to_drain, pcp);
		pcp->count -= to_drain;
	}
1182
	local_irq_restore(flags);
1183 1184 1185
}
#endif

1186 1187 1188 1189 1190 1191 1192 1193
/*
 * 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
1194
{
N
Nick Piggin 已提交
1195
	unsigned long flags;
L
Linus Torvalds 已提交
1196 1197
	struct zone *zone;

1198
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
1199
		struct per_cpu_pageset *pset;
1200
		struct per_cpu_pages *pcp;
L
Linus Torvalds 已提交
1201

1202 1203
		local_irq_save(flags);
		pset = per_cpu_ptr(zone->pageset, cpu);
1204 1205

		pcp = &pset->pcp;
1206 1207 1208 1209
		if (pcp->count) {
			free_pcppages_bulk(zone, pcp->count, pcp);
			pcp->count = 0;
		}
1210
		local_irq_restore(flags);
L
Linus Torvalds 已提交
1211 1212 1213
	}
}

1214 1215 1216 1217 1218 1219 1220 1221 1222
/*
 * 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());
}

/*
1223 1224 1225 1226 1227 1228 1229
 * 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().
1230 1231 1232
 */
void drain_all_pages(void)
{
1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263
	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);
1264 1265
}

1266
#ifdef CONFIG_HIBERNATION
L
Linus Torvalds 已提交
1267 1268 1269

void mark_free_pages(struct zone *zone)
{
1270 1271
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
1272
	int order, t;
L
Linus Torvalds 已提交
1273 1274 1275 1276 1277 1278
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
1279 1280 1281 1282 1283 1284

	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);

1285 1286
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
1287
		}
L
Linus Torvalds 已提交
1288

1289 1290
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
1291
			unsigned long i;
L
Linus Torvalds 已提交
1292

1293 1294
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
1295
				swsusp_set_page_free(pfn_to_page(pfn + i));
1296
		}
1297
	}
L
Linus Torvalds 已提交
1298 1299
	spin_unlock_irqrestore(&zone->lock, flags);
}
1300
#endif /* CONFIG_PM */
L
Linus Torvalds 已提交
1301 1302 1303

/*
 * Free a 0-order page
L
Li Hong 已提交
1304
 * cold == 1 ? free a cold page : free a hot page
L
Linus Torvalds 已提交
1305
 */
L
Li Hong 已提交
1306
void free_hot_cold_page(struct page *page, int cold)
L
Linus Torvalds 已提交
1307 1308 1309 1310
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;
1311
	int migratetype;
L
Linus Torvalds 已提交
1312

1313
	if (!free_pages_prepare(page, 0))
1314 1315
		return;

1316
	migratetype = get_pageblock_migratetype(page);
1317
	set_freepage_migratetype(page, migratetype);
L
Linus Torvalds 已提交
1318
	local_irq_save(flags);
1319
	__count_vm_event(PGFREE);
1320

1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335
	/*
	 * 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;
	}

1336
	pcp = &this_cpu_ptr(zone->pageset)->pcp;
1337
	if (cold)
1338
		list_add_tail(&page->lru, &pcp->lists[migratetype]);
1339
	else
1340
		list_add(&page->lru, &pcp->lists[migratetype]);
L
Linus Torvalds 已提交
1341
	pcp->count++;
N
Nick Piggin 已提交
1342
	if (pcp->count >= pcp->high) {
1343
		free_pcppages_bulk(zone, pcp->batch, pcp);
N
Nick Piggin 已提交
1344 1345
		pcp->count -= pcp->batch;
	}
1346 1347

out:
L
Linus Torvalds 已提交
1348 1349 1350
	local_irq_restore(flags);
}

1351 1352 1353 1354 1355 1356 1357 1358
/*
 * 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) {
1359
		trace_mm_page_free_batched(page, cold);
1360 1361 1362 1363
		free_hot_cold_page(page, cold);
	}
}

N
Nick Piggin 已提交
1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375
/*
 * 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
1376 1377
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1378 1379 1380 1381 1382 1383 1384 1385 1386 1387

#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

1388 1389
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
1390 1391
}

1392
/*
1393 1394 1395
 * 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
1396
 */
1397
int capture_free_page(struct page *page, int alloc_order, int migratetype)
1398 1399 1400 1401
{
	unsigned int order;
	unsigned long watermark;
	struct zone *zone;
1402
	int mt;
1403 1404 1405 1406 1407

	BUG_ON(!PageBuddy(page));

	zone = page_zone(page);
	order = page_order(page);
1408
	mt = get_pageblock_migratetype(page);
1409

1410 1411 1412 1413 1414 1415 1416 1417
	if (mt != MIGRATE_ISOLATE) {
		/* 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;

		__mod_zone_freepage_state(zone, -(1UL << alloc_order), mt);
	}
1418 1419 1420 1421 1422

	/* Remove page from free list */
	list_del(&page->lru);
	zone->free_area[order].nr_free--;
	rmv_page_order(page);
1423

1424 1425 1426
	if (alloc_order != order)
		expand(zone, page, alloc_order, order,
			&zone->free_area[order], migratetype);
1427

1428
	/* Set the pageblock if the captured page is at least a pageblock */
1429 1430
	if (order >= pageblock_order - 1) {
		struct page *endpage = page + (1 << order) - 1;
1431 1432 1433 1434 1435 1436
		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);
		}
1437 1438
	}

1439
	return 1UL << alloc_order;
1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467
}

/*
 * 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;
1468 1469
}

L
Linus Torvalds 已提交
1470 1471 1472 1473 1474
/*
 * 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.
 */
1475 1476
static inline
struct page *buffered_rmqueue(struct zone *preferred_zone,
1477 1478
			struct zone *zone, int order, gfp_t gfp_flags,
			int migratetype)
L
Linus Torvalds 已提交
1479 1480
{
	unsigned long flags;
1481
	struct page *page;
L
Linus Torvalds 已提交
1482 1483
	int cold = !!(gfp_flags & __GFP_COLD);

1484
again:
N
Nick Piggin 已提交
1485
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1486
		struct per_cpu_pages *pcp;
1487
		struct list_head *list;
L
Linus Torvalds 已提交
1488 1489

		local_irq_save(flags);
1490 1491
		pcp = &this_cpu_ptr(zone->pageset)->pcp;
		list = &pcp->lists[migratetype];
1492
		if (list_empty(list)) {
1493
			pcp->count += rmqueue_bulk(zone, 0,
1494
					pcp->batch, list,
1495
					migratetype, cold);
1496
			if (unlikely(list_empty(list)))
1497
				goto failed;
1498
		}
1499

1500 1501 1502 1503 1504
		if (cold)
			page = list_entry(list->prev, struct page, lru);
		else
			page = list_entry(list->next, struct page, lru);

1505 1506
		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1507
	} else {
1508 1509 1510 1511 1512 1513 1514 1515
		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
1516
			 * allocate greater than order-1 page units with
1517 1518
			 * __GFP_NOFAIL.
			 */
1519
			WARN_ON_ONCE(order > 1);
1520
		}
L
Linus Torvalds 已提交
1521
		spin_lock_irqsave(&zone->lock, flags);
1522
		page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1523 1524 1525
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
1526 1527
		__mod_zone_freepage_state(zone, -(1 << order),
					  get_pageblock_migratetype(page));
L
Linus Torvalds 已提交
1528 1529
	}

1530
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
A
Andi Kleen 已提交
1531
	zone_statistics(preferred_zone, zone, gfp_flags);
N
Nick Piggin 已提交
1532
	local_irq_restore(flags);
L
Linus Torvalds 已提交
1533

N
Nick Piggin 已提交
1534
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1535
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1536
		goto again;
L
Linus Torvalds 已提交
1537
	return page;
N
Nick Piggin 已提交
1538 1539 1540 1541

failed:
	local_irq_restore(flags);
	return NULL;
L
Linus Torvalds 已提交
1542 1543
}

1544 1545
#ifdef CONFIG_FAIL_PAGE_ALLOC

1546
static struct {
1547 1548 1549 1550
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1551
	u32 min_order;
1552 1553
} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1554 1555
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1556
	.min_order = 1,
1557 1558 1559 1560 1561 1562 1563 1564
};

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);

1565
static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1566
{
1567
	if (order < fail_page_alloc.min_order)
1568
		return false;
1569
	if (gfp_mask & __GFP_NOFAIL)
1570
		return false;
1571
	if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1572
		return false;
1573
	if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1574
		return false;
1575 1576 1577 1578 1579 1580 1581 1582

	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
1583
	umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1584 1585
	struct dentry *dir;

1586 1587 1588 1589
	dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
					&fail_page_alloc.attr);
	if (IS_ERR(dir))
		return PTR_ERR(dir);
1590

1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602
	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:
1603
	debugfs_remove_recursive(dir);
1604

1605
	return -ENOMEM;
1606 1607 1608 1609 1610 1611 1612 1613
}

late_initcall(fail_page_alloc_debugfs);

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

#else /* CONFIG_FAIL_PAGE_ALLOC */

1614
static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1615
{
1616
	return false;
1617 1618 1619 1620
}

#endif /* CONFIG_FAIL_PAGE_ALLOC */

L
Linus Torvalds 已提交
1621
/*
1622
 * Return true if free pages are above 'mark'. This takes into account the order
L
Linus Torvalds 已提交
1623 1624
 * of the allocation.
 */
1625 1626
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
1627 1628
{
	/* free_pages my go negative - that's OK */
1629
	long min = mark;
1630
	long lowmem_reserve = z->lowmem_reserve[classzone_idx];
L
Linus Torvalds 已提交
1631 1632
	int o;

1633
	free_pages -= (1 << order) - 1;
R
Rohit Seth 已提交
1634
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1635
		min -= min / 2;
R
Rohit Seth 已提交
1636
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1637
		min -= min / 4;
1638 1639 1640 1641 1642
#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
1643
	if (free_pages <= min + lowmem_reserve)
1644
		return false;
L
Linus Torvalds 已提交
1645 1646 1647 1648 1649 1650 1651 1652
	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)
1653
			return false;
L
Linus Torvalds 已提交
1654
	}
1655 1656 1657
	return true;
}

1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671
#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

1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686
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);

1687 1688 1689 1690 1691 1692 1693 1694
	/*
	 * 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);
1695 1696
	return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
								free_pages);
L
Linus Torvalds 已提交
1697 1698
}

1699 1700 1701 1702 1703 1704
#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
1705
 * that have to skip over a lot of full or unallowed zones.
1706 1707 1708
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1709
 * tasks mems_allowed, or node_states[N_MEMORY].)
1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730
 *
 * 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
1731
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1732 1733 1734 1735 1736 1737
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1738
					&node_states[N_MEMORY];
1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763
	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.
 */
1764
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1765 1766 1767 1768 1769 1770 1771 1772 1773 1774
						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;

1775
	i = z - zonelist->_zonerefs;
1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786
	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.
 */
1787
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1788 1789 1790 1791 1792 1793 1794 1795
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

1796
	i = z - zonelist->_zonerefs;
1797 1798 1799 1800

	set_bit(i, zlc->fullzones);
}

1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815
/*
 * 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);
}

1816 1817 1818 1819 1820 1821 1822 1823 1824 1825
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)
1826
		if (node_distance(nid, i) <= RECLAIM_DISTANCE)
1827
			node_set(i, NODE_DATA(nid)->reclaim_nodes);
1828
		else
1829 1830 1831
			zone_reclaim_mode = 1;
}

1832 1833 1834 1835 1836 1837 1838
#else	/* CONFIG_NUMA */

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

1839
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1840 1841 1842 1843 1844
				nodemask_t *allowednodes)
{
	return 1;
}

1845
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1846 1847
{
}
1848 1849 1850 1851

static void zlc_clear_zones_full(struct zonelist *zonelist)
{
}
1852 1853 1854 1855 1856 1857 1858 1859 1860

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

static inline void init_zone_allows_reclaim(int nid)
{
}
1861 1862
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1863
/*
1864
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1865 1866 1867
 * a page.
 */
static struct page *
1868
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1869
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1870
		struct zone *preferred_zone, int migratetype)
M
Martin Hicks 已提交
1871
{
1872
	struct zoneref *z;
R
Rohit Seth 已提交
1873
	struct page *page = NULL;
1874
	int classzone_idx;
1875
	struct zone *zone;
1876 1877 1878
	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 */
1879

1880
	classzone_idx = zone_idx(preferred_zone);
1881
zonelist_scan:
R
Rohit Seth 已提交
1882
	/*
1883
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1884 1885
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1886 1887
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1888
		if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
1889 1890
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1891
		if ((alloc_flags & ALLOC_CPUSET) &&
1892
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1893
				continue;
1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922
		/*
		 * 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
1923

1924
		BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
R
Rohit Seth 已提交
1925
		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1926
			unsigned long mark;
1927 1928
			int ret;

1929
			mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1930 1931 1932 1933
			if (zone_watermark_ok(zone, order, mark,
				    classzone_idx, alloc_flags))
				goto try_this_zone;

1934 1935
			if (IS_ENABLED(CONFIG_NUMA) &&
					!did_zlc_setup && nr_online_nodes > 1) {
1936 1937 1938 1939 1940 1941 1942 1943 1944 1945
				/*
				 * 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;
			}

1946 1947
			if (zone_reclaim_mode == 0 ||
			    !zone_allows_reclaim(preferred_zone, zone))
1948 1949
				goto this_zone_full;

1950 1951 1952 1953
			/*
			 * As we may have just activated ZLC, check if the first
			 * eligible zone has failed zone_reclaim recently.
			 */
1954
			if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
1955 1956 1957
				!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;

1958 1959 1960 1961
			ret = zone_reclaim(zone, gfp_mask, order);
			switch (ret) {
			case ZONE_RECLAIM_NOSCAN:
				/* did not scan */
1962
				continue;
1963 1964
			case ZONE_RECLAIM_FULL:
				/* scanned but unreclaimable */
1965
				continue;
1966 1967 1968 1969
			default:
				/* did we reclaim enough */
				if (!zone_watermark_ok(zone, order, mark,
						classzone_idx, alloc_flags))
1970
					goto this_zone_full;
1971
			}
R
Rohit Seth 已提交
1972 1973
		}

1974
try_this_zone:
1975 1976
		page = buffered_rmqueue(preferred_zone, zone, order,
						gfp_mask, migratetype);
1977
		if (page)
R
Rohit Seth 已提交
1978
			break;
1979
this_zone_full:
1980
		if (IS_ENABLED(CONFIG_NUMA))
1981
			zlc_mark_zone_full(zonelist, z);
1982
	}
1983

1984
	if (unlikely(IS_ENABLED(CONFIG_NUMA) && page == NULL && zlc_active)) {
1985 1986 1987 1988
		/* Disable zlc cache for second zonelist scan */
		zlc_active = 0;
		goto zonelist_scan;
	}
1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999

	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
2000
	return page;
M
Martin Hicks 已提交
2001 2002
}

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
/*
 * 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;
}

2017 2018 2019 2020 2021 2022 2023 2024
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;

2025 2026
	if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
	    debug_guardpage_minorder() > 0)
2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041
		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
2042 2043 2044
		struct va_format vaf;
		va_list args;

2045
		va_start(args, fmt);
J
Joe Perches 已提交
2046 2047 2048 2049 2050 2051

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

		pr_warn("%pV", &vaf);

2052 2053 2054
		va_end(args);
	}

J
Joe Perches 已提交
2055 2056
	pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
		current->comm, order, gfp_mask);
2057 2058 2059 2060 2061 2062

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

2063 2064
static inline int
should_alloc_retry(gfp_t gfp_mask, unsigned int order,
2065
				unsigned long did_some_progress,
2066
				unsigned long pages_reclaimed)
L
Linus Torvalds 已提交
2067
{
2068 2069 2070
	/* Do not loop if specifically requested */
	if (gfp_mask & __GFP_NORETRY)
		return 0;
L
Linus Torvalds 已提交
2071

2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083
	/* 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;

2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100
	/*
	 * 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;
2101

2102 2103
	return 0;
}
2104

2105 2106 2107
static inline struct page *
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
2108 2109
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
2110 2111 2112 2113
{
	struct page *page;

	/* Acquire the OOM killer lock for the zones in zonelist */
2114
	if (!try_set_zonelist_oom(zonelist, gfp_mask)) {
2115
		schedule_timeout_uninterruptible(1);
L
Linus Torvalds 已提交
2116 2117
		return NULL;
	}
2118

2119 2120 2121 2122 2123 2124 2125
	/*
	 * 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,
2126
		ALLOC_WMARK_HIGH|ALLOC_CPUSET,
2127
		preferred_zone, migratetype);
R
Rohit Seth 已提交
2128
	if (page)
2129 2130
		goto out;

2131 2132 2133 2134
	if (!(gfp_mask & __GFP_NOFAIL)) {
		/* The OOM killer will not help higher order allocs */
		if (order > PAGE_ALLOC_COSTLY_ORDER)
			goto out;
2135 2136 2137
		/* The OOM killer does not needlessly kill tasks for lowmem */
		if (high_zoneidx < ZONE_NORMAL)
			goto out;
2138 2139 2140 2141 2142 2143 2144 2145 2146 2147
		/*
		 * 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;
	}
2148
	/* Exhausted what can be done so it's blamo time */
2149
	out_of_memory(zonelist, gfp_mask, order, nodemask, false);
2150 2151 2152 2153 2154 2155

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

2156 2157 2158 2159 2160 2161
#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,
2162
	int migratetype, bool sync_migration,
2163
	bool *contended_compaction, bool *deferred_compaction,
2164
	unsigned long *did_some_progress)
2165
{
2166
	struct page *page = NULL;
2167

2168
	if (!order)
2169 2170
		return NULL;

2171
	if (compaction_deferred(preferred_zone, order)) {
2172 2173 2174 2175
		*deferred_compaction = true;
		return NULL;
	}

2176
	current->flags |= PF_MEMALLOC;
2177
	*did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
2178
						nodemask, sync_migration,
2179
						contended_compaction, &page);
2180
	current->flags &= ~PF_MEMALLOC;
2181

2182 2183 2184 2185 2186 2187 2188
	/* 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) {
2189 2190 2191 2192 2193 2194
		/* 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,
2195 2196
				alloc_flags & ~ALLOC_NO_WATERMARKS,
				preferred_zone, migratetype);
2197
		if (page) {
2198
got_page:
2199
			preferred_zone->compact_blockskip_flush = false;
2200 2201
			preferred_zone->compact_considered = 0;
			preferred_zone->compact_defer_shift = 0;
2202 2203
			if (order >= preferred_zone->compact_order_failed)
				preferred_zone->compact_order_failed = order + 1;
2204 2205 2206 2207 2208 2209 2210 2211 2212 2213
			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);
2214 2215 2216 2217 2218 2219

		/*
		 * As async compaction considers a subset of pageblocks, only
		 * defer if the failure was a sync compaction failure.
		 */
		if (sync_migration)
2220
			defer_compaction(preferred_zone, order);
2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231

		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,
2232
	int migratetype, bool sync_migration,
2233
	bool *contended_compaction, bool *deferred_compaction,
2234
	unsigned long *did_some_progress)
2235 2236 2237 2238 2239
{
	return NULL;
}
#endif /* CONFIG_COMPACTION */

2240 2241 2242 2243
/* Perform direct synchronous page reclaim */
static int
__perform_reclaim(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist,
		  nodemask_t *nodemask)
2244 2245
{
	struct reclaim_state reclaim_state;
2246
	int progress;
2247 2248 2249 2250 2251

	cond_resched();

	/* We now go into synchronous reclaim */
	cpuset_memory_pressure_bump();
2252
	current->flags |= PF_MEMALLOC;
2253 2254
	lockdep_set_current_reclaim_state(gfp_mask);
	reclaim_state.reclaimed_slab = 0;
2255
	current->reclaim_state = &reclaim_state;
2256

2257
	progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
2258

2259
	current->reclaim_state = NULL;
2260
	lockdep_clear_current_reclaim_state();
2261
	current->flags &= ~PF_MEMALLOC;
2262 2263 2264

	cond_resched();

2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279
	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);
2280 2281
	if (unlikely(!(*did_some_progress)))
		return NULL;
2282

2283
	/* After successful reclaim, reconsider all zones for allocation */
2284
	if (IS_ENABLED(CONFIG_NUMA))
2285 2286
		zlc_clear_zones_full(zonelist);

2287 2288
retry:
	page = get_page_from_freelist(gfp_mask, nodemask, order,
2289
					zonelist, high_zoneidx,
2290 2291
					alloc_flags & ~ALLOC_NO_WATERMARKS,
					preferred_zone, migratetype);
2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302

	/*
	 * 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;
	}

2303 2304 2305
	return page;
}

L
Linus Torvalds 已提交
2306
/*
2307 2308
 * 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
2309
 */
2310 2311 2312
static inline struct page *
__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
2313 2314
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
2315 2316 2317 2318 2319
{
	struct page *page;

	do {
		page = get_page_from_freelist(gfp_mask, nodemask, order,
2320
			zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
2321
			preferred_zone, migratetype);
2322 2323

		if (!page && gfp_mask & __GFP_NOFAIL)
2324
			wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2325 2326 2327 2328 2329 2330 2331
	} while (!page && (gfp_mask & __GFP_NOFAIL));

	return page;
}

static inline
void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
2332 2333
						enum zone_type high_zoneidx,
						enum zone_type classzone_idx)
L
Linus Torvalds 已提交
2334
{
2335 2336
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
2337

2338
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
2339
		wakeup_kswapd(zone, order, classzone_idx);
2340
}
2341

2342 2343 2344 2345 2346
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
2347

2348
	/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2349
	BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2350

2351 2352 2353 2354 2355 2356
	/*
	 * 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).
	 */
2357
	alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
L
Linus Torvalds 已提交
2358

2359
	if (!wait) {
2360 2361 2362 2363 2364 2365
		/*
		 * Not worth trying to allocate harder for
		 * __GFP_NOMEMALLOC even if it can't schedule.
		 */
		if  (!(gfp_mask & __GFP_NOMEMALLOC))
			alloc_flags |= ALLOC_HARDER;
2366
		/*
2367 2368
		 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
		 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2369
		 */
2370
		alloc_flags &= ~ALLOC_CPUSET;
2371
	} else if (unlikely(rt_task(current)) && !in_interrupt())
2372 2373
		alloc_flags |= ALLOC_HARDER;

2374 2375 2376
	if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
		if (gfp_mask & __GFP_MEMALLOC)
			alloc_flags |= ALLOC_NO_WATERMARKS;
2377 2378 2379 2380 2381
		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))))
2382
			alloc_flags |= ALLOC_NO_WATERMARKS;
L
Linus Torvalds 已提交
2383
	}
2384 2385 2386 2387
#ifdef CONFIG_CMA
	if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
		alloc_flags |= ALLOC_CMA;
#endif
2388 2389 2390
	return alloc_flags;
}

2391 2392
bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
{
2393
	return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
2394 2395
}

2396 2397 2398
static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
2399 2400
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
2401 2402 2403 2404 2405 2406
{
	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;
2407
	bool sync_migration = false;
2408
	bool deferred_compaction = false;
2409
	bool contended_compaction = false;
L
Linus Torvalds 已提交
2410

2411 2412 2413 2414 2415 2416
	/*
	 * 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.
	 */
2417 2418
	if (order >= MAX_ORDER) {
		WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2419
		return NULL;
2420
	}
L
Linus Torvalds 已提交
2421

2422 2423 2424 2425 2426 2427 2428 2429
	/*
	 * 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.
	 */
2430 2431
	if (IS_ENABLED(CONFIG_NUMA) &&
			(gfp_mask & GFP_THISNODE) == GFP_THISNODE)
2432 2433
		goto nopage;

2434
restart:
2435 2436 2437
	if (!(gfp_mask & __GFP_NO_KSWAPD))
		wake_all_kswapd(order, zonelist, high_zoneidx,
						zone_idx(preferred_zone));
L
Linus Torvalds 已提交
2438

2439
	/*
R
Rohit Seth 已提交
2440 2441 2442
	 * 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.
2443
	 */
2444
	alloc_flags = gfp_to_alloc_flags(gfp_mask);
L
Linus Torvalds 已提交
2445

2446 2447 2448 2449 2450 2451 2452 2453
	/*
	 * 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);

2454
rebalance:
2455
	/* This is the last chance, in general, before the goto nopage. */
2456
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
2457 2458
			high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
			preferred_zone, migratetype);
R
Rohit Seth 已提交
2459 2460
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
2461

2462
	/* Allocate without watermarks if the context allows */
2463
	if (alloc_flags & ALLOC_NO_WATERMARKS) {
2464 2465 2466 2467 2468 2469 2470
		/*
		 * 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);

2471 2472 2473
		page = __alloc_pages_high_priority(gfp_mask, order,
				zonelist, high_zoneidx, nodemask,
				preferred_zone, migratetype);
2474
		if (page) {
2475
			goto got_pg;
2476
		}
L
Linus Torvalds 已提交
2477 2478 2479 2480 2481 2482
	}

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

2483
	/* Avoid recursion of direct reclaim */
2484
	if (current->flags & PF_MEMALLOC)
2485 2486
		goto nopage;

2487 2488 2489 2490
	/* Avoid allocations with no watermarks from looping endlessly */
	if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
		goto nopage;

2491 2492 2493 2494
	/*
	 * Try direct compaction. The first pass is asynchronous. Subsequent
	 * attempts after direct reclaim are synchronous
	 */
2495 2496 2497 2498
	page = __alloc_pages_direct_compact(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
					alloc_flags, preferred_zone,
2499
					migratetype, sync_migration,
2500
					&contended_compaction,
2501 2502
					&deferred_compaction,
					&did_some_progress);
2503 2504
	if (page)
		goto got_pg;
2505
	sync_migration = true;
2506

2507 2508 2509 2510 2511 2512 2513
	/*
	 * If compaction is deferred for high-order allocations, it is because
	 * sync compaction recently failed. In this is the case and the caller
	 * requested a movable allocation that does not heavily disrupt the
	 * system then fail the allocation instead of entering direct reclaim.
	 */
	if ((deferred_compaction || contended_compaction) &&
2514
						(gfp_mask & __GFP_NO_KSWAPD))
2515
		goto nopage;
2516

2517 2518 2519 2520
	/* Try direct reclaim and then allocating */
	page = __alloc_pages_direct_reclaim(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
2521
					alloc_flags, preferred_zone,
2522
					migratetype, &did_some_progress);
2523 2524
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
2525

2526
	/*
2527 2528
	 * If we failed to make any progress reclaiming, then we are
	 * running out of options and have to consider going OOM
2529
	 */
2530 2531
	if (!did_some_progress) {
		if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
2532 2533
			if (oom_killer_disabled)
				goto nopage;
2534 2535 2536 2537
			/* Coredumps can quickly deplete all memory reserves */
			if ((current->flags & PF_DUMPCORE) &&
			    !(gfp_mask & __GFP_NOFAIL))
				goto nopage;
2538 2539
			page = __alloc_pages_may_oom(gfp_mask, order,
					zonelist, high_zoneidx,
2540 2541
					nodemask, preferred_zone,
					migratetype);
2542 2543
			if (page)
				goto got_pg;
L
Linus Torvalds 已提交
2544

2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561
			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;
			}
2562

2563 2564
			goto restart;
		}
L
Linus Torvalds 已提交
2565 2566
	}

2567
	/* Check if we should retry the allocation */
2568
	pages_reclaimed += did_some_progress;
2569 2570
	if (should_alloc_retry(gfp_mask, order, did_some_progress,
						pages_reclaimed)) {
2571
		/* Wait for some write requests to complete then retry */
2572
		wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
L
Linus Torvalds 已提交
2573
		goto rebalance;
2574 2575 2576 2577 2578 2579 2580 2581 2582 2583
	} 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,
2584
					migratetype, sync_migration,
2585
					&contended_compaction,
2586 2587
					&deferred_compaction,
					&did_some_progress);
2588 2589
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
2590 2591 2592
	}

nopage:
2593
	warn_alloc_failed(gfp_mask, order, NULL);
2594
	return page;
L
Linus Torvalds 已提交
2595
got_pg:
2596 2597
	if (kmemcheck_enabled)
		kmemcheck_pagealloc_alloc(page, order, gfp_mask);
2598

2599
	return page;
L
Linus Torvalds 已提交
2600
}
2601 2602 2603 2604 2605 2606 2607 2608 2609

/*
 * 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);
2610
	struct zone *preferred_zone;
2611
	struct page *page = NULL;
2612
	int migratetype = allocflags_to_migratetype(gfp_mask);
2613
	unsigned int cpuset_mems_cookie;
2614
	int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET;
2615

2616 2617
	gfp_mask &= gfp_allowed_mask;

2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632
	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;

2633 2634 2635
retry_cpuset:
	cpuset_mems_cookie = get_mems_allowed();

2636
	/* The preferred zone is used for statistics later */
2637 2638 2639
	first_zones_zonelist(zonelist, high_zoneidx,
				nodemask ? : &cpuset_current_mems_allowed,
				&preferred_zone);
2640 2641
	if (!preferred_zone)
		goto out;
2642

2643 2644 2645 2646
#ifdef CONFIG_CMA
	if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
		alloc_flags |= ALLOC_CMA;
#endif
2647
	/* First allocation attempt */
2648
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
2649
			zonelist, high_zoneidx, alloc_flags,
2650
			preferred_zone, migratetype);
2651 2652
	if (unlikely(!page))
		page = __alloc_pages_slowpath(gfp_mask, order,
2653
				zonelist, high_zoneidx, nodemask,
2654
				preferred_zone, migratetype);
2655

2656
	trace_mm_page_alloc(page, order, gfp_mask, migratetype);
2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667

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;

2668
	return page;
L
Linus Torvalds 已提交
2669
}
2670
EXPORT_SYMBOL(__alloc_pages_nodemask);
L
Linus Torvalds 已提交
2671 2672 2673 2674

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
2675
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
2676
{
2677 2678 2679 2680 2681 2682 2683 2684
	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
2685 2686 2687 2688 2689 2690 2691
	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
2692
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
2693
{
2694
	return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
L
Linus Torvalds 已提交
2695 2696 2697
}
EXPORT_SYMBOL(get_zeroed_page);

H
Harvey Harrison 已提交
2698
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
2699
{
N
Nick Piggin 已提交
2700
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
2701
		if (order == 0)
L
Li Hong 已提交
2702
			free_hot_cold_page(page, 0);
L
Linus Torvalds 已提交
2703 2704 2705 2706 2707 2708 2709
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
2710
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
2711 2712
{
	if (addr != 0) {
N
Nick Piggin 已提交
2713
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
2714 2715 2716 2717 2718 2719
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

A
Andi Kleen 已提交
2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734
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;
}

2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753
/**
 * 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
2754
	return make_alloc_exact(addr, order, size);
2755 2756 2757
}
EXPORT_SYMBOL(alloc_pages_exact);

A
Andi Kleen 已提交
2758 2759 2760
/**
 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
 *			   pages on a node.
2761
 * @nid: the preferred node ID where memory should be allocated
A
Andi Kleen 已提交
2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779
 * @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);

2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798
/**
 * 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
2799 2800
static unsigned int nr_free_zone_pages(int offset)
{
2801
	struct zoneref *z;
2802 2803
	struct zone *zone;

2804
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
2805 2806
	unsigned int sum = 0;

2807
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
2808

2809
	for_each_zone_zonelist(zone, z, zonelist, offset) {
2810
		unsigned long size = zone->present_pages;
2811
		unsigned long high = high_wmark_pages(zone);
2812 2813
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
2814 2815 2816 2817 2818 2819 2820 2821 2822 2823
	}

	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
2824
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
2825
}
2826
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
2827 2828 2829 2830 2831 2832

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
2833
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
2834
}
2835 2836

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
2837
{
2838
	if (IS_ENABLED(CONFIG_NUMA))
2839
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
2840 2841 2842 2843 2844 2845
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
2846
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860
	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;
2861
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
2862
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2863
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2864 2865
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
2866 2867 2868 2869
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
2870 2871 2872 2873
	val->mem_unit = PAGE_SIZE;
}
#endif

2874
/*
2875 2876
 * Determine whether the node should be displayed or not, depending on whether
 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2877
 */
2878
bool skip_free_areas_node(unsigned int flags, int nid)
2879 2880
{
	bool ret = false;
2881
	unsigned int cpuset_mems_cookie;
2882 2883 2884 2885

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

2886 2887 2888 2889
	do {
		cpuset_mems_cookie = get_mems_allowed();
		ret = !node_isset(nid, cpuset_current_mems_allowed);
	} while (!put_mems_allowed(cpuset_mems_cookie));
2890 2891 2892 2893
out:
	return ret;
}

L
Linus Torvalds 已提交
2894 2895
#define K(x) ((x) << (PAGE_SHIFT-10))

2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920
static void show_migration_types(unsigned char type)
{
	static const char types[MIGRATE_TYPES] = {
		[MIGRATE_UNMOVABLE]	= 'U',
		[MIGRATE_RECLAIMABLE]	= 'E',
		[MIGRATE_MOVABLE]	= 'M',
		[MIGRATE_RESERVE]	= 'R',
#ifdef CONFIG_CMA
		[MIGRATE_CMA]		= 'C',
#endif
		[MIGRATE_ISOLATE]	= 'I',
	};
	char tmp[MIGRATE_TYPES + 1];
	char *p = tmp;
	int i;

	for (i = 0; i < MIGRATE_TYPES; i++) {
		if (type & (1 << i))
			*p++ = types[i];
	}

	*p = '\0';
	printk("(%s) ", tmp);
}

L
Linus Torvalds 已提交
2921 2922 2923 2924
/*
 * 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.
2925 2926
 * Suppresses nodes that are not allowed by current's cpuset if
 * SHOW_MEM_FILTER_NODES is passed.
L
Linus Torvalds 已提交
2927
 */
2928
void show_free_areas(unsigned int filter)
L
Linus Torvalds 已提交
2929
{
2930
	int cpu;
L
Linus Torvalds 已提交
2931 2932
	struct zone *zone;

2933
	for_each_populated_zone(zone) {
2934
		if (skip_free_areas_node(filter, zone_to_nid(zone)))
2935
			continue;
2936 2937
		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
2938

2939
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
2940 2941
			struct per_cpu_pageset *pageset;

2942
			pageset = per_cpu_ptr(zone->pageset, cpu);
L
Linus Torvalds 已提交
2943

2944 2945 2946
			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
2947 2948 2949
		}
	}

K
KOSAKI Motohiro 已提交
2950 2951
	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
2952
		" unevictable:%lu"
2953
		" dirty:%lu writeback:%lu unstable:%lu\n"
2954
		" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2955 2956
		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
		" free_cma:%lu\n",
2957 2958
		global_page_state(NR_ACTIVE_ANON),
		global_page_state(NR_INACTIVE_ANON),
K
KOSAKI Motohiro 已提交
2959 2960
		global_page_state(NR_ISOLATED_ANON),
		global_page_state(NR_ACTIVE_FILE),
2961
		global_page_state(NR_INACTIVE_FILE),
K
KOSAKI Motohiro 已提交
2962
		global_page_state(NR_ISOLATED_FILE),
L
Lee Schermerhorn 已提交
2963
		global_page_state(NR_UNEVICTABLE),
2964
		global_page_state(NR_FILE_DIRTY),
2965
		global_page_state(NR_WRITEBACK),
2966
		global_page_state(NR_UNSTABLE_NFS),
2967
		global_page_state(NR_FREE_PAGES),
2968 2969
		global_page_state(NR_SLAB_RECLAIMABLE),
		global_page_state(NR_SLAB_UNRECLAIMABLE),
2970
		global_page_state(NR_FILE_MAPPED),
2971
		global_page_state(NR_SHMEM),
2972
		global_page_state(NR_PAGETABLE),
2973 2974
		global_page_state(NR_BOUNCE),
		global_page_state(NR_FREE_CMA_PAGES));
L
Linus Torvalds 已提交
2975

2976
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
2977 2978
		int i;

2979
		if (skip_free_areas_node(filter, zone_to_nid(zone)))
2980
			continue;
L
Linus Torvalds 已提交
2981 2982 2983 2984 2985 2986
		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
2987 2988 2989 2990
			" active_anon:%lukB"
			" inactive_anon:%lukB"
			" active_file:%lukB"
			" inactive_file:%lukB"
L
Lee Schermerhorn 已提交
2991
			" unevictable:%lukB"
K
KOSAKI Motohiro 已提交
2992 2993
			" isolated(anon):%lukB"
			" isolated(file):%lukB"
L
Linus Torvalds 已提交
2994
			" present:%lukB"
2995
			" managed:%lukB"
2996 2997 2998 2999
			" mlocked:%lukB"
			" dirty:%lukB"
			" writeback:%lukB"
			" mapped:%lukB"
3000
			" shmem:%lukB"
3001 3002
			" slab_reclaimable:%lukB"
			" slab_unreclaimable:%lukB"
3003
			" kernel_stack:%lukB"
3004 3005 3006
			" pagetables:%lukB"
			" unstable:%lukB"
			" bounce:%lukB"
3007
			" free_cma:%lukB"
3008
			" writeback_tmp:%lukB"
L
Linus Torvalds 已提交
3009 3010 3011 3012
			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
3013
			K(zone_page_state(zone, NR_FREE_PAGES)),
3014 3015 3016
			K(min_wmark_pages(zone)),
			K(low_wmark_pages(zone)),
			K(high_wmark_pages(zone)),
3017 3018 3019 3020
			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
3021
			K(zone_page_state(zone, NR_UNEVICTABLE)),
K
KOSAKI Motohiro 已提交
3022 3023
			K(zone_page_state(zone, NR_ISOLATED_ANON)),
			K(zone_page_state(zone, NR_ISOLATED_FILE)),
L
Linus Torvalds 已提交
3024
			K(zone->present_pages),
3025
			K(zone->managed_pages),
3026 3027 3028 3029
			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)),
3030
			K(zone_page_state(zone, NR_SHMEM)),
3031 3032
			K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
			K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
3033 3034
			zone_page_state(zone, NR_KERNEL_STACK) *
				THREAD_SIZE / 1024,
3035 3036 3037
			K(zone_page_state(zone, NR_PAGETABLE)),
			K(zone_page_state(zone, NR_UNSTABLE_NFS)),
			K(zone_page_state(zone, NR_BOUNCE)),
3038
			K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
3039
			K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
L
Linus Torvalds 已提交
3040
			zone->pages_scanned,
3041
			(zone->all_unreclaimable ? "yes" : "no")
L
Linus Torvalds 已提交
3042 3043 3044 3045 3046 3047 3048
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

3049
	for_each_populated_zone(zone) {
3050
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
3051
		unsigned char types[MAX_ORDER];
L
Linus Torvalds 已提交
3052

3053
		if (skip_free_areas_node(filter, zone_to_nid(zone)))
3054
			continue;
L
Linus Torvalds 已提交
3055 3056 3057 3058 3059
		show_node(zone);
		printk("%s: ", zone->name);

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
3060 3061 3062 3063
			struct free_area *area = &zone->free_area[order];
			int type;

			nr[order] = area->nr_free;
3064
			total += nr[order] << order;
3065 3066 3067 3068 3069 3070

			types[order] = 0;
			for (type = 0; type < MIGRATE_TYPES; type++) {
				if (!list_empty(&area->free_list[type]))
					types[order] |= 1 << type;
			}
L
Linus Torvalds 已提交
3071 3072
		}
		spin_unlock_irqrestore(&zone->lock, flags);
3073
		for (order = 0; order < MAX_ORDER; order++) {
3074
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
3075 3076 3077
			if (nr[order])
				show_migration_types(types[order]);
		}
L
Linus Torvalds 已提交
3078 3079 3080
		printk("= %lukB\n", K(total));
	}

3081 3082
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

L
Linus Torvalds 已提交
3083 3084 3085
	show_swap_cache_info();
}

3086 3087 3088 3089 3090 3091
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
3092 3093
/*
 * Builds allocation fallback zone lists.
3094 3095
 *
 * Add all populated zones of a node to the zonelist.
L
Linus Torvalds 已提交
3096
 */
3097 3098
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
3099
{
3100 3101
	struct zone *zone;

3102
	BUG_ON(zone_type >= MAX_NR_ZONES);
3103
	zone_type++;
3104 3105

	do {
3106
		zone_type--;
3107
		zone = pgdat->node_zones + zone_type;
3108
		if (populated_zone(zone)) {
3109 3110
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
3111
			check_highest_zone(zone_type);
L
Linus Torvalds 已提交
3112
		}
3113

3114
	} while (zone_type);
3115
	return nr_zones;
L
Linus Torvalds 已提交
3116 3117
}

3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138

/*
 *  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
3139
#ifdef CONFIG_NUMA
3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172
/* 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)
{
3173 3174 3175 3176 3177 3178 3179 3180 3181 3182
	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;
3183 3184 3185 3186 3187 3188 3189
}
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,
3190
		void __user *buffer, size_t *length,
3191 3192 3193 3194
		loff_t *ppos)
{
	char saved_string[NUMA_ZONELIST_ORDER_LEN];
	int ret;
3195
	static DEFINE_MUTEX(zl_order_mutex);
3196

3197
	mutex_lock(&zl_order_mutex);
3198
	if (write)
3199
		strcpy(saved_string, (char*)table->data);
3200
	ret = proc_dostring(table, write, buffer, length, ppos);
3201
	if (ret)
3202
		goto out;
3203 3204 3205 3206 3207 3208 3209 3210 3211
	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;
3212 3213
		} else if (oldval != user_zonelist_order) {
			mutex_lock(&zonelists_mutex);
3214
			build_all_zonelists(NULL, NULL);
3215 3216
			mutex_unlock(&zonelists_mutex);
		}
3217
	}
3218 3219 3220
out:
	mutex_unlock(&zl_order_mutex);
	return ret;
3221 3222 3223
}


3224
#define MAX_NODE_LOAD (nr_online_nodes)
3225 3226
static int node_load[MAX_NUMNODES];

L
Linus Torvalds 已提交
3227
/**
3228
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
Linus Torvalds 已提交
3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240
 * @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.
 */
3241
static int find_next_best_node(int node, nodemask_t *used_node_mask)
L
Linus Torvalds 已提交
3242
{
3243
	int n, val;
L
Linus Torvalds 已提交
3244 3245
	int min_val = INT_MAX;
	int best_node = -1;
3246
	const struct cpumask *tmp = cpumask_of_node(0);
L
Linus Torvalds 已提交
3247

3248 3249 3250 3251 3252
	/* 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
3253

3254
	for_each_node_state(n, N_MEMORY) {
L
Linus Torvalds 已提交
3255 3256 3257 3258 3259 3260 3261 3262

		/* 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);

3263 3264 3265
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
Linus Torvalds 已提交
3266
		/* Give preference to headless and unused nodes */
3267 3268
		tmp = cpumask_of_node(n);
		if (!cpumask_empty(tmp))
L
Linus Torvalds 已提交
3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286
			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;
}

3287 3288 3289 3290 3291 3292 3293

/*
 * 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
3294
{
3295
	int j;
L
Linus Torvalds 已提交
3296
	struct zonelist *zonelist;
3297

3298
	zonelist = &pgdat->node_zonelists[0];
3299
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
3300 3301 3302
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
3303 3304
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
3305 3306
}

3307 3308 3309 3310 3311 3312 3313 3314
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

3315 3316
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
3317 3318
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
3319 3320
}

3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335
/*
 * 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;

3336 3337 3338 3339 3340 3341 3342
	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)) {
3343 3344
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
3345
				check_highest_zone(zone_type);
3346 3347 3348
			}
		}
	}
3349 3350
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
3351 3352 3353 3354 3355 3356 3357 3358 3359
}

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
3360
         * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3361 3362
	 * If they are really small and used heavily, the system can fall
	 * into OOM very easily.
3363
	 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374
	 */
	/* 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;
3375 3376 3377 3378 3379 3380 3381 3382 3383
			} 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;
3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394
			}
		}
	}
	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.
         */
3395
	average_size = total_size /
3396
				(nodes_weight(node_states[N_MEMORY]) + 1);
3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427
	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
3428
	nodemask_t used_mask;
3429 3430 3431
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
L
Linus Torvalds 已提交
3432 3433

	/* initialize zonelists */
3434
	for (i = 0; i < MAX_ZONELISTS; i++) {
L
Linus Torvalds 已提交
3435
		zonelist = pgdat->node_zonelists + i;
3436 3437
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
L
Linus Torvalds 已提交
3438 3439 3440 3441
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
3442
	load = nr_online_nodes;
L
Linus Torvalds 已提交
3443 3444
	prev_node = local_node;
	nodes_clear(used_mask);
3445 3446 3447 3448

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

L
Linus Torvalds 已提交
3449 3450 3451 3452 3453 3454
	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.
		 */
3455 3456
		if (node_distance(local_node, node) !=
		    node_distance(local_node, prev_node))
3457 3458
			node_load[node] = load;

L
Linus Torvalds 已提交
3459 3460
		prev_node = node;
		load--;
3461 3462 3463 3464 3465
		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
3466

3467 3468 3469
	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
3470
	}
3471 3472

	build_thisnode_zonelists(pgdat);
L
Linus Torvalds 已提交
3473 3474
}

3475
/* Construct the zonelist performance cache - see further mmzone.h */
3476
static void build_zonelist_cache(pg_data_t *pgdat)
3477
{
3478 3479
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
3480
	struct zoneref *z;
3481

3482 3483 3484
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3485 3486
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3487 3488
}

3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506
#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
3507

L
Linus Torvalds 已提交
3508 3509
#else	/* CONFIG_NUMA */

3510 3511 3512 3513 3514 3515
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
3516
{
3517
	int node, local_node;
3518 3519
	enum zone_type j;
	struct zonelist *zonelist;
L
Linus Torvalds 已提交
3520 3521 3522

	local_node = pgdat->node_id;

3523 3524
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
3525

3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538
	/*
	 * 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
3539
	}
3540 3541 3542 3543 3544 3545 3546
	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);
	}

3547 3548
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
L
Linus Torvalds 已提交
3549 3550
}

3551
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3552
static void build_zonelist_cache(pg_data_t *pgdat)
3553
{
3554
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
3555 3556
}

L
Linus Torvalds 已提交
3557 3558
#endif	/* CONFIG_NUMA */

3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575
/*
 * 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);
3576
static void setup_zone_pageset(struct zone *zone);
3577

3578 3579 3580 3581 3582 3583
/*
 * 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);

3584
/* return values int ....just for stop_machine() */
3585
static int __build_all_zonelists(void *data)
L
Linus Torvalds 已提交
3586
{
3587
	int nid;
3588
	int cpu;
3589
	pg_data_t *self = data;
3590

3591 3592 3593
#ifdef CONFIG_NUMA
	memset(node_load, 0, sizeof(node_load));
#endif
3594 3595 3596 3597 3598 3599

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

3600
	for_each_online_node(nid) {
3601 3602 3603 3604
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
3605
	}
3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619

	/*
	 * 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).
	 */
3620
	for_each_possible_cpu(cpu) {
3621 3622
		setup_pageset(&per_cpu(boot_pageset, cpu), 0);

3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636
#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
	}

3637 3638 3639
	return 0;
}

3640 3641 3642 3643
/*
 * Called with zonelists_mutex held always
 * unless system_state == SYSTEM_BOOTING.
 */
3644
void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
3645
{
3646 3647
	set_zonelist_order();

3648
	if (system_state == SYSTEM_BOOTING) {
3649
		__build_all_zonelists(NULL);
3650
		mminit_verify_zonelist();
3651 3652
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
3653
		/* we have to stop all cpus to guarantee there is no user
3654
		   of zonelist */
3655
#ifdef CONFIG_MEMORY_HOTPLUG
3656 3657
		if (zone)
			setup_zone_pageset(zone);
3658
#endif
3659
		stop_machine(__build_all_zonelists, pgdat, NULL);
3660 3661
		/* cpuset refresh routine should be here */
	}
3662
	vm_total_pages = nr_free_pagecache_pages();
3663 3664 3665 3666 3667 3668 3669
	/*
	 * 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
	 */
3670
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
3671 3672 3673 3674 3675 3676
		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",
3677
			nr_online_nodes,
3678
			zonelist_order_name[current_zonelist_order],
3679
			page_group_by_mobility_disabled ? "off" : "on",
3680 3681 3682 3683
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
L
Linus Torvalds 已提交
3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698
}

/*
 * 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

3699
#ifndef CONFIG_MEMORY_HOTPLUG
3700
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717
{
	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);
}
3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740
#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
3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753

/*
 * 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))

3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767
/*
 * 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;
}

3768
/*
3769
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3770 3771
 * 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
3772 3773 3774 3775 3776
 * 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)
{
3777
	unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
3778
	struct page *page;
3779 3780
	unsigned long block_migratetype;
	int reserve;
3781

3782 3783 3784 3785 3786 3787
	/*
	 * 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.
	 */
3788 3789
	start_pfn = zone->zone_start_pfn;
	end_pfn = start_pfn + zone->spanned_pages;
3790
	start_pfn = roundup(start_pfn, pageblock_nr_pages);
3791
	reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
3792
							pageblock_order;
3793

3794 3795 3796 3797 3798 3799 3800 3801 3802
	/*
	 * 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);

3803
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
3804 3805 3806 3807
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

3808 3809 3810 3811
		/* Watch out for overlapping nodes */
		if (page_to_nid(page) != zone_to_nid(zone))
			continue;

3812 3813
		block_migratetype = get_pageblock_migratetype(page);

3814 3815 3816 3817 3818 3819 3820 3821 3822
		/* 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;
3823

3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838
			/* 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;
			}
3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850
		}

		/*
		 * 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
3851

L
Linus Torvalds 已提交
3852 3853 3854 3855 3856
/*
 * 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.
 */
3857
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
3858
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
3859 3860
{
	struct page *page;
A
Andy Whitcroft 已提交
3861 3862
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
3863
	struct zone *z;
L
Linus Torvalds 已提交
3864

3865 3866 3867
	if (highest_memmap_pfn < end_pfn - 1)
		highest_memmap_pfn = end_pfn - 1;

3868
	z = &NODE_DATA(nid)->node_zones[zone];
3869
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880
		/*
		 * 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
3881 3882
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
3883
		mminit_verify_page_links(page, zone, nid, pfn);
3884
		init_page_count(page);
L
Linus Torvalds 已提交
3885
		reset_page_mapcount(page);
3886
		reset_page_last_nid(page);
L
Linus Torvalds 已提交
3887
		SetPageReserved(page);
3888 3889 3890 3891 3892
		/*
		 * 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
3893 3894 3895
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
3896 3897 3898 3899 3900
		 *
		 * 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.
3901
		 */
3902 3903 3904
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
3905
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
3906

L
Linus Torvalds 已提交
3907 3908 3909 3910
		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))
3911
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
3912 3913 3914 3915
#endif
	}
}

3916
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
3917
{
3918 3919 3920
	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
3921 3922 3923 3924 3925 3926
		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
3927
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
3928 3929
#endif

3930
static int __meminit zone_batchsize(struct zone *zone)
3931
{
3932
#ifdef CONFIG_MMU
3933 3934 3935 3936
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
3937
	 * size of the zone.  But no more than 1/2 of a meg.
3938 3939 3940 3941
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
3942 3943
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
3944 3945 3946 3947 3948
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
3949 3950 3951
	 * 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.
3952
	 *
3953 3954 3955 3956
	 * 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.
3957
	 */
3958
	batch = rounddown_pow_of_two(batch + batch/2) - 1;
3959

3960
	return batch;
3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977

#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
3978 3979
}

A
Adrian Bunk 已提交
3980
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3981 3982
{
	struct per_cpu_pages *pcp;
3983
	int migratetype;
3984

3985 3986
	memset(p, 0, sizeof(*p));

3987
	pcp = &p->pcp;
3988 3989 3990
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
3991 3992
	for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
		INIT_LIST_HEAD(&pcp->lists[migratetype]);
3993 3994
}

3995 3996 3997 3998 3999 4000 4001 4002 4003 4004
/*
 * 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;

4005
	pcp = &p->pcp;
4006 4007 4008 4009 4010 4011
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}

4012
static void __meminit setup_zone_pageset(struct zone *zone)
4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029
{
	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));
	}
}

4030
/*
4031 4032
 * Allocate per cpu pagesets and initialize them.
 * Before this call only boot pagesets were available.
4033
 */
4034
void __init setup_per_cpu_pageset(void)
4035
{
4036
	struct zone *zone;
4037

4038 4039
	for_each_populated_zone(zone)
		setup_zone_pageset(zone);
4040 4041
}

S
Sam Ravnborg 已提交
4042
static noinline __init_refok
4043
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
4044 4045 4046
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
4047
	size_t alloc_size;
4048 4049 4050 4051 4052

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
4053 4054 4055 4056
	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);
4057 4058 4059
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

4060
	if (!slab_is_available()) {
4061
		zone->wait_table = (wait_queue_head_t *)
4062
			alloc_bootmem_node_nopanic(pgdat, alloc_size);
4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073
	} 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.
		 */
4074
		zone->wait_table = vmalloc(alloc_size);
4075 4076 4077
	}
	if (!zone->wait_table)
		return -ENOMEM;
4078

4079
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
4080
		init_waitqueue_head(zone->wait_table + i);
4081 4082

	return 0;
4083 4084
}

4085
static __meminit void zone_pcp_init(struct zone *zone)
4086
{
4087 4088 4089 4090 4091 4092
	/*
	 * 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;
4093

A
Anton Blanchard 已提交
4094
	if (zone->present_pages)
4095 4096 4097
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%u\n",
			zone->name, zone->present_pages,
					 zone_batchsize(zone));
4098 4099
}

4100
int __meminit init_currently_empty_zone(struct zone *zone,
4101
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
4102 4103
					unsigned long size,
					enum memmap_context context)
4104 4105
{
	struct pglist_data *pgdat = zone->zone_pgdat;
4106 4107 4108 4109
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
4110 4111 4112 4113
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

4114 4115 4116 4117 4118 4119
	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));

4120
	zone_init_free_lists(zone);
4121 4122

	return 0;
4123 4124
}

T
Tejun Heo 已提交
4125
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4126 4127 4128 4129 4130 4131 4132
#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
 */
4133
int __meminit __early_pfn_to_nid(unsigned long pfn)
4134
{
4135 4136
	unsigned long start_pfn, end_pfn;
	int i, nid;
4137

4138
	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
4139
		if (start_pfn <= pfn && pfn < end_pfn)
4140
			return nid;
4141 4142
	/* This is a memory hole */
	return -1;
4143 4144 4145
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

4146 4147
int __meminit early_pfn_to_nid(unsigned long pfn)
{
4148 4149 4150 4151 4152 4153 4154
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0)
		return nid;
	/* just returns 0 */
	return 0;
4155 4156
}

4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167
#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
4168

4169 4170
/**
 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
4171 4172
 * @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
4173 4174 4175 4176 4177
 *
 * 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.
 */
4178
void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
4179
{
4180 4181
	unsigned long start_pfn, end_pfn;
	int i, this_nid;
4182

4183 4184 4185
	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);
4186

4187 4188 4189 4190
		if (start_pfn < end_pfn)
			free_bootmem_node(NODE_DATA(this_nid),
					  PFN_PHYS(start_pfn),
					  (end_pfn - start_pfn) << PAGE_SHIFT);
4191 4192 4193
	}
}

4194 4195
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4196
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4197 4198 4199
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
4200
 * function may be used instead of calling memory_present() manually.
4201 4202 4203
 */
void __init sparse_memory_present_with_active_regions(int nid)
{
4204 4205
	unsigned long start_pfn, end_pfn;
	int i, this_nid;
4206

4207 4208
	for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
		memory_present(this_nid, start_pfn, end_pfn);
4209 4210 4211 4212
}

/**
 * get_pfn_range_for_nid - Return the start and end page frames for a node
4213 4214 4215
 * @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.
4216 4217 4218 4219
 *
 * 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
4220
 * PFNs will be 0.
4221
 */
4222
void __meminit get_pfn_range_for_nid(unsigned int nid,
4223 4224
			unsigned long *start_pfn, unsigned long *end_pfn)
{
4225
	unsigned long this_start_pfn, this_end_pfn;
4226
	int i;
4227

4228 4229 4230
	*start_pfn = -1UL;
	*end_pfn = 0;

4231 4232 4233
	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);
4234 4235
	}

4236
	if (*start_pfn == -1UL)
4237 4238 4239
		*start_pfn = 0;
}

M
Mel Gorman 已提交
4240 4241 4242 4243 4244
/*
 * 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
4245
static void __init find_usable_zone_for_movable(void)
M
Mel Gorman 已提交
4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262
{
	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
4263
 * because it is sized independent of architecture. Unlike the other zones,
M
Mel Gorman 已提交
4264 4265 4266 4267 4268 4269 4270
 * 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
4271
static void __meminit adjust_zone_range_for_zone_movable(int nid,
M
Mel Gorman 已提交
4272 4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293 4294 4295 4296
					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;
	}
}

4297 4298 4299 4300
/*
 * 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
4301
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
4302 4303 4304 4305 4306 4307 4308 4309 4310 4311
					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
4312 4313 4314
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
4315 4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329

	/* 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,
4330
 * then all holes in the requested range will be accounted for.
4331
 */
4332
unsigned long __meminit __absent_pages_in_range(int nid,
4333 4334 4335
				unsigned long range_start_pfn,
				unsigned long range_end_pfn)
{
4336 4337 4338
	unsigned long nr_absent = range_end_pfn - range_start_pfn;
	unsigned long start_pfn, end_pfn;
	int i;
4339

4340 4341 4342 4343
	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;
4344
	}
4345
	return nr_absent;
4346 4347 4348 4349 4350 4351 4352
}

/**
 * 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
 *
4353
 * It returns the number of pages frames in memory holes within a range.
4354 4355 4356 4357 4358 4359 4360 4361
 */
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
4362
static unsigned long __meminit zone_absent_pages_in_node(int nid,
4363 4364 4365
					unsigned long zone_type,
					unsigned long *ignored)
{
4366 4367
	unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
	unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
4368 4369 4370 4371
	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);
4372 4373
	zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
	zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
4374

M
Mel Gorman 已提交
4375 4376 4377
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
4378
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
4379
}
4380

T
Tejun Heo 已提交
4381
#else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
P
Paul Mundt 已提交
4382
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
4383 4384 4385 4386 4387 4388
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
4389
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
4390 4391 4392 4393 4394 4395 4396 4397
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
4398

T
Tejun Heo 已提交
4399
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4400

4401
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
4402 4403 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421
		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);
}

4422 4423 4424
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
4425 4426
 * 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
4427 4428 4429 4430 4431 4432 4433
 * 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;

4434 4435
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
4436 4437 4438 4439 4440 4441 4442 4443 4444 4445 4446
	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;
4447
	if (usemapsize)
4448 4449
		zone->pageblock_flags = alloc_bootmem_node_nopanic(pgdat,
								   usemapsize);
4450 4451
}
#else
4452
static inline void setup_usemap(struct pglist_data *pgdat,
4453 4454 4455
				struct zone *zone, unsigned long zonesize) {}
#endif /* CONFIG_SPARSEMEM */

4456
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4457

4458
/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4459
void __init set_pageblock_order(void)
4460
{
4461 4462
	unsigned int order;

4463 4464 4465 4466
	/* Check that pageblock_nr_pages has not already been setup */
	if (pageblock_order)
		return;

4467 4468 4469 4470 4471
	if (HPAGE_SHIFT > PAGE_SHIFT)
		order = HUGETLB_PAGE_ORDER;
	else
		order = MAX_ORDER - 1;

4472 4473
	/*
	 * Assume the largest contiguous order of interest is a huge page.
4474 4475
	 * This value may be variable depending on boot parameters on IA64 and
	 * powerpc.
4476 4477 4478 4479 4480
	 */
	pageblock_order = order;
}
#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

4481 4482
/*
 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4483 4484 4485
 * 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
4486
 */
4487
void __init set_pageblock_order(void)
4488 4489
{
}
4490 4491 4492

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

4493 4494 4495 4496 4497 4498 4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512
static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
						   unsigned long present_pages)
{
	unsigned long pages = spanned_pages;

	/*
	 * Provide a more accurate estimation if there are holes within
	 * the zone and SPARSEMEM is in use. If there are holes within the
	 * zone, each populated memory region may cost us one or two extra
	 * memmap pages due to alignment because memmap pages for each
	 * populated regions may not naturally algined on page boundary.
	 * So the (present_pages >> 4) heuristic is a tradeoff for that.
	 */
	if (spanned_pages > present_pages + (present_pages >> 4) &&
	    IS_ENABLED(CONFIG_SPARSEMEM))
		pages = present_pages;

	return PAGE_ALIGN(pages * sizeof(struct page)) >> PAGE_SHIFT;
}

L
Linus Torvalds 已提交
4513 4514 4515 4516 4517
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
4518 4519
 *
 * NOTE: pgdat should get zeroed by caller.
L
Linus Torvalds 已提交
4520
 */
4521
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
4522 4523
		unsigned long *zones_size, unsigned long *zholes_size)
{
4524
	enum zone_type j;
4525
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
4526
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
4527
	int ret;
L
Linus Torvalds 已提交
4528

4529
	pgdat_resize_init(pgdat);
4530 4531 4532 4533 4534
#ifdef CONFIG_NUMA_BALANCING
	spin_lock_init(&pgdat->numabalancing_migrate_lock);
	pgdat->numabalancing_migrate_nr_pages = 0;
	pgdat->numabalancing_migrate_next_window = jiffies;
#endif
L
Linus Torvalds 已提交
4535
	init_waitqueue_head(&pgdat->kswapd_wait);
4536
	init_waitqueue_head(&pgdat->pfmemalloc_wait);
4537
	pgdat_page_cgroup_init(pgdat);
4538

L
Linus Torvalds 已提交
4539 4540
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
4541
		unsigned long size, realsize, freesize, memmap_pages;
L
Linus Torvalds 已提交
4542

4543
		size = zone_spanned_pages_in_node(nid, j, zones_size);
4544
		realsize = freesize = size - zone_absent_pages_in_node(nid, j,
4545
								zholes_size);
L
Linus Torvalds 已提交
4546

4547
		/*
4548
		 * Adjust freesize so that it accounts for how much memory
4549 4550 4551
		 * is used by this zone for memmap. This affects the watermark
		 * and per-cpu initialisations
		 */
4552
		memmap_pages = calc_memmap_size(size, realsize);
4553 4554
		if (freesize >= memmap_pages) {
			freesize -= memmap_pages;
4555 4556 4557 4558
			if (memmap_pages)
				printk(KERN_DEBUG
				       "  %s zone: %lu pages used for memmap\n",
				       zone_names[j], memmap_pages);
4559 4560
		} else
			printk(KERN_WARNING
4561 4562
				"  %s zone: %lu pages exceeds freesize %lu\n",
				zone_names[j], memmap_pages, freesize);
4563

4564
		/* Account for reserved pages */
4565 4566
		if (j == 0 && freesize > dma_reserve) {
			freesize -= dma_reserve;
Y
Yinghai Lu 已提交
4567
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
4568
					zone_names[0], dma_reserve);
4569 4570
		}

4571
		if (!is_highmem_idx(j))
4572
			nr_kernel_pages += freesize;
4573 4574 4575
		/* Charge for highmem memmap if there are enough kernel pages */
		else if (nr_kernel_pages > memmap_pages * 2)
			nr_kernel_pages -= memmap_pages;
4576
		nr_all_pages += freesize;
L
Linus Torvalds 已提交
4577 4578

		zone->spanned_pages = size;
4579 4580 4581 4582 4583 4584 4585
		zone->present_pages = freesize;
		/*
		 * Set an approximate value for lowmem here, it will be adjusted
		 * when the bootmem allocator frees pages into the buddy system.
		 * And all highmem pages will be managed by the buddy system.
		 */
		zone->managed_pages = is_highmem_idx(j) ? realsize : freesize;
4586
#ifdef CONFIG_NUMA
4587
		zone->node = nid;
4588
		zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
4589
						/ 100;
4590
		zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
4591
#endif
L
Linus Torvalds 已提交
4592 4593 4594
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
4595
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
4596 4597
		zone->zone_pgdat = pgdat;

4598
		zone_pcp_init(zone);
4599
		lruvec_init(&zone->lruvec);
L
Linus Torvalds 已提交
4600 4601 4602
		if (!size)
			continue;

4603
		set_pageblock_order();
4604
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
4605 4606
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
4607
		BUG_ON(ret);
4608
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
4609 4610 4611 4612
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
4613
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
4614 4615 4616 4617 4618
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
4619
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
4620 4621
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
4622
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
4623 4624
		struct page *map;

4625 4626 4627 4628 4629 4630 4631 4632 4633
		/*
		 * 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);
4634 4635
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
4636
			map = alloc_bootmem_node_nopanic(pgdat, size);
4637
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
4638
	}
4639
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
4640 4641 4642
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
4643
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
4644
		mem_map = NODE_DATA(0)->node_mem_map;
T
Tejun Heo 已提交
4645
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4646
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4647
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
T
Tejun Heo 已提交
4648
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4649
	}
L
Linus Torvalds 已提交
4650
#endif
A
Andy Whitcroft 已提交
4651
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
4652 4653
}

4654 4655
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
4656
{
4657 4658
	pg_data_t *pgdat = NODE_DATA(nid);

4659
	/* pg_data_t should be reset to zero when it's allocated */
4660
	WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
4661

L
Linus Torvalds 已提交
4662 4663
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
4664
	init_zone_allows_reclaim(nid);
4665
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
4666 4667

	alloc_node_mem_map(pgdat);
4668 4669 4670 4671 4672
#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
4673 4674 4675 4676

	free_area_init_core(pgdat, zones_size, zholes_size);
}

T
Tejun Heo 已提交
4677
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
M
Miklos Szeredi 已提交
4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689 4690 4691 4692 4693 4694 4695 4696 4697

#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

4698 4699 4700 4701 4702 4703 4704 4705 4706 4707 4708 4709 4710 4711 4712 4713 4714 4715 4716 4717 4718 4719
/**
 * 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;
4720
	unsigned long start, end, mask;
4721
	int last_nid = -1;
4722
	int i, nid;
4723

4724
	for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
4725 4726 4727 4728 4729 4730 4731 4732 4733 4734 4735 4736 4737 4738 4739 4740 4741 4742 4743 4744 4745 4746 4747
		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;
}

4748
/* Find the lowest pfn for a node */
A
Adrian Bunk 已提交
4749
static unsigned long __init find_min_pfn_for_node(int nid)
4750
{
4751
	unsigned long min_pfn = ULONG_MAX;
4752 4753
	unsigned long start_pfn;
	int i;
4754

4755 4756
	for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
		min_pfn = min(min_pfn, start_pfn);
4757

4758 4759
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
4760
			"Could not find start_pfn for node %d\n", nid);
4761 4762 4763 4764
		return 0;
	}

	return min_pfn;
4765 4766 4767 4768 4769 4770
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
4771
 * add_active_range().
4772 4773 4774 4775 4776 4777
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

4778 4779 4780
/*
 * early_calculate_totalpages()
 * Sum pages in active regions for movable zone.
4781
 * Populate N_MEMORY for calculating usable_nodes.
4782
 */
A
Adrian Bunk 已提交
4783
static unsigned long __init early_calculate_totalpages(void)
4784 4785
{
	unsigned long totalpages = 0;
4786 4787 4788 4789 4790
	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;
4791

4792 4793
		totalpages += pages;
		if (pages)
4794
			node_set_state(nid, N_MEMORY);
4795 4796
	}
  	return totalpages;
4797 4798
}

M
Mel Gorman 已提交
4799 4800 4801 4802 4803 4804
/*
 * 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
 */
4805
static void __init find_zone_movable_pfns_for_nodes(void)
M
Mel Gorman 已提交
4806 4807 4808 4809
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
4810
	/* save the state before borrow the nodemask */
4811
	nodemask_t saved_node_state = node_states[N_MEMORY];
4812
	unsigned long totalpages = early_calculate_totalpages();
4813
	int usable_nodes = nodes_weight(node_states[N_MEMORY]);
M
Mel Gorman 已提交
4814

4815 4816 4817 4818 4819 4820 4821 4822 4823 4824 4825 4826 4827 4828 4829 4830 4831 4832 4833 4834 4835 4836
	/*
	 * 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
4837 4838
	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
	if (!required_kernelcore)
4839
		goto out;
M
Mel Gorman 已提交
4840 4841 4842 4843 4844 4845 4846 4847

	/* 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;
4848
	for_each_node_state(nid, N_MEMORY) {
4849 4850
		unsigned long start_pfn, end_pfn;

M
Mel Gorman 已提交
4851 4852 4853 4854 4855 4856 4857 4858 4859 4860 4861 4862 4863 4864 4865 4866
		/*
		 * 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 */
4867
		for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
M
Mel Gorman 已提交
4868 4869
			unsigned long size_pages;

4870
			start_pfn = max(start_pfn, zone_movable_pfn[nid]);
M
Mel Gorman 已提交
4871 4872 4873 4874 4875 4876 4877 4878 4879 4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893 4894 4895 4896 4897 4898 4899 4900 4901 4902 4903 4904 4905 4906 4907 4908 4909 4910 4911 4912 4913 4914 4915 4916 4917 4918 4919 4920 4921 4922 4923 4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935 4936
			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);
4937 4938 4939

out:
	/* restore the node_state */
4940
	node_states[N_MEMORY] = saved_node_state;
M
Mel Gorman 已提交
4941 4942
}

4943 4944
/* Any regular or high memory on that node ? */
static void check_for_memory(pg_data_t *pgdat, int nid)
4945 4946 4947
{
	enum zone_type zone_type;

4948 4949 4950 4951
	if (N_MEMORY == N_NORMAL_MEMORY)
		return;

	for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
4952
		struct zone *zone = &pgdat->node_zones[zone_type];
4953
		if (zone->present_pages) {
4954 4955 4956 4957
			node_set_state(nid, N_HIGH_MEMORY);
			if (N_NORMAL_MEMORY != N_HIGH_MEMORY &&
			    zone_type <= ZONE_NORMAL)
				node_set_state(nid, N_NORMAL_MEMORY);
4958 4959
			break;
		}
4960 4961 4962
	}
}

4963 4964
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
4965
 * @max_zone_pfn: an array of max PFNs for each zone
4966 4967 4968 4969 4970 4971 4972 4973 4974 4975 4976 4977
 *
 * 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)
{
4978 4979
	unsigned long start_pfn, end_pfn;
	int i, nid;
4980

4981 4982 4983 4984 4985 4986 4987 4988
	/* 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
4989 4990
		if (i == ZONE_MOVABLE)
			continue;
4991 4992 4993 4994 4995
		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
4996 4997 4998 4999 5000
	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));
5001
	find_zone_movable_pfns_for_nodes();
5002 5003

	/* Print out the zone ranges */
5004
	printk("Zone ranges:\n");
M
Mel Gorman 已提交
5005 5006 5007
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
5008
		printk(KERN_CONT "  %-8s ", zone_names[i]);
5009 5010
		if (arch_zone_lowest_possible_pfn[i] ==
				arch_zone_highest_possible_pfn[i])
5011
			printk(KERN_CONT "empty\n");
5012
		else
5013 5014 5015 5016
			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
5017 5018 5019
	}

	/* Print out the PFNs ZONE_MOVABLE begins at in each node */
5020
	printk("Movable zone start for each node\n");
M
Mel Gorman 已提交
5021 5022
	for (i = 0; i < MAX_NUMNODES; i++) {
		if (zone_movable_pfn[i])
5023 5024
			printk("  Node %d: %#010lx\n", i,
			       zone_movable_pfn[i] << PAGE_SHIFT);
M
Mel Gorman 已提交
5025
	}
5026

5027
	/* Print out the early node map */
5028
	printk("Early memory node ranges\n");
5029
	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
5030 5031
		printk("  node %3d: [mem %#010lx-%#010lx]\n", nid,
		       start_pfn << PAGE_SHIFT, (end_pfn << PAGE_SHIFT) - 1);
5032 5033

	/* Initialise every node */
5034
	mminit_verify_pageflags_layout();
5035
	setup_nr_node_ids();
5036 5037
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
5038
		free_area_init_node(nid, NULL,
5039
				find_min_pfn_for_node(nid), NULL);
5040 5041 5042

		/* Any memory on that node */
		if (pgdat->node_present_pages)
5043 5044
			node_set_state(nid, N_MEMORY);
		check_for_memory(pgdat, nid);
5045 5046
	}
}
M
Mel Gorman 已提交
5047

5048
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
5049 5050 5051 5052 5053 5054
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
5055
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
5056

5057
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
5058 5059 5060 5061
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
5062

5063 5064 5065 5066 5067 5068 5069 5070 5071 5072 5073 5074 5075 5076 5077 5078 5079 5080
/*
 * 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
5081
early_param("kernelcore", cmdline_parse_kernelcore);
5082
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
5083

T
Tejun Heo 已提交
5084
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5085

5086
/**
5087 5088
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
5089 5090 5091 5092
 *
 * 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
5093 5094 5095
 * 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.
5096 5097 5098 5099 5100 5101
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

L
Linus Torvalds 已提交
5102 5103
void __init free_area_init(unsigned long *zones_size)
{
5104
	free_area_init_node(0, zones_size,
L
Linus Torvalds 已提交
5105 5106 5107 5108 5109 5110 5111 5112
			__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;

5113
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
5114
		lru_add_drain_cpu(cpu);
5115 5116 5117 5118 5119 5120 5121 5122
		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.
		 */
5123
		vm_events_fold_cpu(cpu);
5124 5125 5126 5127 5128 5129 5130 5131

		/*
		 * 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.
		 */
5132
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
5133 5134 5135 5136 5137 5138 5139 5140 5141
	}
	return NOTIFY_OK;
}

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

5142 5143 5144 5145 5146 5147 5148 5149
/*
 * 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;
5150
	enum zone_type i, j;
5151 5152 5153 5154 5155 5156 5157 5158 5159 5160 5161 5162

	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];
			}

5163 5164
			/* we treat the high watermark as reserved pages. */
			max += high_wmark_pages(zone);
5165 5166 5167 5168

			if (max > zone->present_pages)
				max = zone->present_pages;
			reserve_pages += max;
5169 5170 5171 5172 5173 5174 5175 5176 5177 5178
			/*
			 * 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;
5179 5180
		}
	}
5181
	dirty_balance_reserve = reserve_pages;
5182 5183 5184
	totalreserve_pages = reserve_pages;
}

L
Linus Torvalds 已提交
5185 5186 5187 5188 5189 5190 5191 5192 5193
/*
 * 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;
5194
	enum zone_type j, idx;
L
Linus Torvalds 已提交
5195

5196
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
5197 5198 5199 5200 5201 5202
		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;

5203 5204
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
5205 5206
				struct zone *lower_zone;

5207 5208
				idx--;

L
Linus Torvalds 已提交
5209 5210 5211 5212 5213 5214 5215 5216 5217 5218
				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;
			}
		}
	}
5219 5220 5221

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
5222 5223
}

5224
static void __setup_per_zone_wmarks(void)
L
Linus Torvalds 已提交
5225 5226 5227 5228 5229 5230 5231 5232 5233 5234 5235 5236 5237
{
	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) {
5238 5239
		u64 tmp;

5240
		spin_lock_irqsave(&zone->lock, flags);
5241 5242
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
5243 5244
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
5245 5246 5247 5248
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
5249
			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
N
Nick Piggin 已提交
5250 5251
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
Linus Torvalds 已提交
5252 5253 5254 5255 5256 5257 5258 5259
			 */
			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;
5260
			zone->watermark[WMARK_MIN] = min_pages;
L
Linus Torvalds 已提交
5261
		} else {
N
Nick Piggin 已提交
5262 5263
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
5264 5265
			 * proportionate to the zone's size.
			 */
5266
			zone->watermark[WMARK_MIN] = tmp;
L
Linus Torvalds 已提交
5267 5268
		}

5269 5270
		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) + (tmp >> 2);
		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
5271

5272
		setup_zone_migrate_reserve(zone);
5273
		spin_unlock_irqrestore(&zone->lock, flags);
L
Linus Torvalds 已提交
5274
	}
5275 5276 5277

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
5278 5279
}

5280 5281 5282 5283 5284 5285 5286 5287 5288 5289 5290 5291 5292 5293
/**
 * 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);
}

5294
/*
5295 5296 5297 5298 5299 5300 5301 5302 5303 5304 5305 5306 5307 5308 5309 5310 5311 5312 5313 5314
 * 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
 */
5315
static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
5316
{
5317
	unsigned int gb, ratio;
5318

5319 5320 5321
	/* Zone size in gigabytes */
	gb = zone->present_pages >> (30 - PAGE_SHIFT);
	if (gb)
5322
		ratio = int_sqrt(10 * gb);
5323 5324
	else
		ratio = 1;
5325

5326 5327
	zone->inactive_ratio = ratio;
}
5328

5329
static void __meminit setup_per_zone_inactive_ratio(void)
5330 5331 5332 5333 5334
{
	struct zone *zone;

	for_each_zone(zone)
		calculate_zone_inactive_ratio(zone);
5335 5336
}

L
Linus Torvalds 已提交
5337 5338 5339 5340 5341 5342 5343 5344 5345 5346 5347 5348 5349 5350 5351 5352 5353 5354 5355 5356 5357 5358 5359 5360
/*
 * 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
 */
5361
int __meminit init_per_zone_wmark_min(void)
L
Linus Torvalds 已提交
5362 5363 5364 5365 5366 5367 5368 5369 5370 5371
{
	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;
5372
	setup_per_zone_wmarks();
5373
	refresh_zone_stat_thresholds();
L
Linus Torvalds 已提交
5374
	setup_per_zone_lowmem_reserve();
5375
	setup_per_zone_inactive_ratio();
L
Linus Torvalds 已提交
5376 5377
	return 0;
}
5378
module_init(init_per_zone_wmark_min)
L
Linus Torvalds 已提交
5379 5380 5381 5382 5383 5384 5385

/*
 * 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, 
5386
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
5387
{
5388
	proc_dointvec(table, write, buffer, length, ppos);
5389
	if (write)
5390
		setup_per_zone_wmarks();
L
Linus Torvalds 已提交
5391 5392 5393
	return 0;
}

5394 5395
#ifdef CONFIG_NUMA
int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
5396
	void __user *buffer, size_t *length, loff_t *ppos)
5397 5398 5399 5400
{
	struct zone *zone;
	int rc;

5401
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5402 5403 5404 5405
	if (rc)
		return rc;

	for_each_zone(zone)
5406
		zone->min_unmapped_pages = (zone->present_pages *
5407 5408 5409
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
5410 5411

int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
5412
	void __user *buffer, size_t *length, loff_t *ppos)
5413 5414 5415 5416
{
	struct zone *zone;
	int rc;

5417
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5418 5419 5420 5421 5422 5423 5424 5425
	if (rc)
		return rc;

	for_each_zone(zone)
		zone->min_slab_pages = (zone->present_pages *
				sysctl_min_slab_ratio) / 100;
	return 0;
}
5426 5427
#endif

L
Linus Torvalds 已提交
5428 5429 5430 5431 5432 5433
/*
 * 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
5434
 * minimum watermarks. The lowmem reserve ratio can only make sense
L
Linus Torvalds 已提交
5435 5436 5437
 * if in function of the boot time zone sizes.
 */
int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
5438
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
5439
{
5440
	proc_dointvec_minmax(table, write, buffer, length, ppos);
L
Linus Torvalds 已提交
5441 5442 5443 5444
	setup_per_zone_lowmem_reserve();
	return 0;
}

5445 5446 5447 5448 5449 5450 5451
/*
 * 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,
5452
	void __user *buffer, size_t *length, loff_t *ppos)
5453 5454 5455 5456 5457
{
	struct zone *zone;
	unsigned int cpu;
	int ret;

5458
	ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5459
	if (!write || (ret < 0))
5460
		return ret;
5461
	for_each_populated_zone(zone) {
5462
		for_each_possible_cpu(cpu) {
5463 5464
			unsigned long  high;
			high = zone->present_pages / percpu_pagelist_fraction;
5465 5466
			setup_pagelist_highmark(
				per_cpu_ptr(zone->pageset, cpu), high);
5467 5468 5469 5470 5471
		}
	}
	return 0;
}

5472
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
5473 5474 5475 5476 5477 5478 5479 5480 5481 5482 5483 5484 5485 5486 5487 5488 5489 5490 5491 5492 5493 5494 5495 5496 5497

#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,
5498 5499
				     unsigned long low_limit,
				     unsigned long high_limit)
L
Linus Torvalds 已提交
5500
{
5501
	unsigned long long max = high_limit;
L
Linus Torvalds 已提交
5502 5503 5504 5505 5506 5507
	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
5508
		numentries = nr_kernel_pages;
L
Linus Torvalds 已提交
5509 5510 5511 5512 5513 5514 5515 5516 5517
		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);
5518 5519

		/* Make sure we've got at least a 0-order allocation.. */
5520 5521 5522 5523 5524 5525 5526 5527
		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))
5528
			numentries = PAGE_SIZE / bucketsize;
L
Linus Torvalds 已提交
5529
	}
5530
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
5531 5532 5533 5534 5535 5536

	/* 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);
	}
5537
	max = min(max, 0x80000000ULL);
L
Linus Torvalds 已提交
5538

5539 5540
	if (numentries < low_limit)
		numentries = low_limit;
L
Linus Torvalds 已提交
5541 5542 5543
	if (numentries > max)
		numentries = max;

5544
	log2qty = ilog2(numentries);
L
Linus Torvalds 已提交
5545 5546 5547 5548

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
5549
			table = alloc_bootmem_nopanic(size);
L
Linus Torvalds 已提交
5550 5551 5552
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
5553 5554
			/*
			 * If bucketsize is not a power-of-two, we may free
5555 5556
			 * some pages at the end of hash table which
			 * alloc_pages_exact() automatically does
5557
			 */
5558
			if (get_order(size) < MAX_ORDER) {
5559
				table = alloc_pages_exact(size, GFP_ATOMIC);
5560 5561
				kmemleak_alloc(table, size, 1, GFP_ATOMIC);
			}
L
Linus Torvalds 已提交
5562 5563 5564 5565 5566 5567
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

5568
	printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
L
Linus Torvalds 已提交
5569
	       tablename,
5570
	       (1UL << log2qty),
5571
	       ilog2(size) - PAGE_SHIFT,
L
Linus Torvalds 已提交
5572 5573 5574 5575 5576 5577 5578 5579 5580
	       size);

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

	return table;
}
5581

5582 5583 5584 5585 5586 5587 5588 5589 5590 5591 5592 5593 5594 5595 5596
/* 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);
5597
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5598 5599
#else
	pfn = pfn - zone->zone_start_pfn;
5600
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5601 5602 5603 5604
#endif /* CONFIG_SPARSEMEM */
}

/**
5605
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5606 5607 5608 5609 5610 5611 5612 5613 5614 5615 5616 5617 5618 5619 5620 5621 5622 5623 5624 5625 5626 5627
 * @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;
5628

5629 5630 5631 5632
	return flags;
}

/**
5633
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5634 5635 5636 5637 5638 5639 5640 5641 5642 5643 5644 5645 5646 5647 5648 5649 5650
 * @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);
5651 5652
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
5653 5654 5655 5656 5657 5658 5659

	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
5660 5661

/*
5662 5663 5664 5665 5666 5667
 * 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
5668
 */
5669 5670
bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
			 bool skip_hwpoisoned_pages)
5671 5672
{
	unsigned long pfn, iter, found;
5673 5674
	int mt;

5675 5676
	/*
	 * For avoiding noise data, lru_add_drain_all() should be called
5677
	 * If ZONE_MOVABLE, the zone never contains unmovable pages
5678 5679
	 */
	if (zone_idx(zone) == ZONE_MOVABLE)
5680
		return false;
5681 5682
	mt = get_pageblock_migratetype(page);
	if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
5683
		return false;
5684 5685 5686 5687 5688

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

5689
		if (!pfn_valid_within(check))
5690
			continue;
5691

5692
		page = pfn_to_page(check);
5693 5694 5695 5696 5697 5698 5699
		/*
		 * 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)) {
5700 5701 5702 5703
			if (PageBuddy(page))
				iter += (1 << page_order(page)) - 1;
			continue;
		}
5704

5705 5706 5707 5708 5709 5710 5711
		/*
		 * The HWPoisoned page may be not in buddy system, and
		 * page_count() is not 0.
		 */
		if (skip_hwpoisoned_pages && PageHWPoison(page))
			continue;

5712 5713 5714 5715 5716 5717 5718 5719 5720 5721 5722 5723 5724 5725 5726 5727
		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)
5728
			return true;
5729
	}
5730
	return false;
5731 5732 5733 5734
}

bool is_pageblock_removable_nolock(struct page *page)
{
5735 5736
	struct zone *zone;
	unsigned long pfn;
5737 5738 5739 5740 5741

	/*
	 * 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.
5742 5743
	 * We have to take care about the node as well. If the node is offline
	 * its NODE_DATA will be NULL - see page_zone.
5744
	 */
5745 5746 5747 5748 5749 5750
	if (!node_online(page_to_nid(page)))
		return false;

	zone = page_zone(page);
	pfn = page_to_pfn(page);
	if (zone->zone_start_pfn > pfn ||
5751 5752 5753
			zone->zone_start_pfn + zone->spanned_pages <= pfn)
		return false;

5754
	return !has_unmovable_pages(zone, page, 0, true);
K
KAMEZAWA Hiroyuki 已提交
5755
}
K
KAMEZAWA Hiroyuki 已提交
5756

5757 5758 5759 5760 5761 5762 5763 5764 5765 5766 5767 5768 5769 5770 5771
#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. */
5772 5773
static int __alloc_contig_migrate_range(struct compact_control *cc,
					unsigned long start, unsigned long end)
5774 5775
{
	/* This function is based on compact_zone() from compaction.c. */
5776
	unsigned long nr_reclaimed;
5777 5778 5779 5780
	unsigned long pfn = start;
	unsigned int tries = 0;
	int ret = 0;

5781
	migrate_prep();
5782

5783
	while (pfn < end || !list_empty(&cc->migratepages)) {
5784 5785 5786 5787 5788
		if (fatal_signal_pending(current)) {
			ret = -EINTR;
			break;
		}

5789 5790 5791
		if (list_empty(&cc->migratepages)) {
			cc->nr_migratepages = 0;
			pfn = isolate_migratepages_range(cc->zone, cc,
M
Minchan Kim 已提交
5792
							 pfn, end, true);
5793 5794 5795 5796 5797 5798 5799 5800 5801 5802
			if (!pfn) {
				ret = -EINTR;
				break;
			}
			tries = 0;
		} else if (++tries == 5) {
			ret = ret < 0 ? ret : -EBUSY;
			break;
		}

5803 5804 5805
		nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
							&cc->migratepages);
		cc->nr_migratepages -= nr_reclaimed;
5806

5807
		ret = migrate_pages(&cc->migratepages,
5808
				    alloc_migrate_target,
5809 5810
				    0, false, MIGRATE_SYNC,
				    MR_CMA);
5811 5812
	}

5813
	putback_movable_pages(&cc->migratepages);
5814 5815 5816 5817 5818 5819 5820
	return ret > 0 ? 0 : ret;
}

/**
 * alloc_contig_range() -- tries to allocate given range of pages
 * @start:	start PFN to allocate
 * @end:	one-past-the-last PFN to allocate
5821 5822 5823 5824
 * @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.
5825 5826 5827 5828 5829 5830 5831 5832 5833 5834 5835 5836
 *
 * 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().
 */
5837 5838
int alloc_contig_range(unsigned long start, unsigned long end,
		       unsigned migratetype)
5839 5840 5841 5842
{
	unsigned long outer_start, outer_end;
	int ret = 0, order;

5843 5844 5845 5846 5847 5848 5849 5850 5851
	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);

5852 5853 5854 5855 5856 5857 5858 5859 5860 5861 5862 5863 5864 5865 5866 5867 5868 5869 5870 5871 5872 5873 5874 5875 5876
	/*
	 * 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),
5877 5878
				       pfn_max_align_up(end), migratetype,
				       false);
5879
	if (ret)
5880
		return ret;
5881

5882
	ret = __alloc_contig_migrate_range(&cc, start, end);
5883 5884 5885 5886 5887 5888 5889 5890 5891 5892 5893 5894 5895 5896 5897 5898 5899 5900 5901 5902 5903 5904 5905 5906 5907 5908 5909 5910 5911 5912 5913 5914 5915 5916
	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. */
5917
	if (test_pages_isolated(outer_start, end, false)) {
5918 5919 5920 5921 5922 5923
		pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
		       outer_start, end);
		ret = -EBUSY;
		goto done;
	}

5924 5925

	/* Grab isolated pages from freelists. */
5926
	outer_end = isolate_freepages_range(&cc, outer_start, end);
5927 5928 5929 5930 5931 5932 5933 5934 5935 5936 5937 5938 5939
	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),
5940
				pfn_max_align_up(end), migratetype);
5941 5942 5943 5944 5945 5946 5947 5948 5949 5950
	return ret;
}

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

5951 5952 5953 5954 5955 5956 5957 5958 5959 5960 5961 5962 5963 5964 5965 5966 5967
#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);
5968
		drain_zonestat(zone, pset);
5969 5970 5971 5972 5973 5974 5975 5976 5977 5978 5979 5980
		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

5981 5982 5983
void zone_pcp_reset(struct zone *zone)
{
	unsigned long flags;
5984 5985
	int cpu;
	struct per_cpu_pageset *pset;
5986 5987 5988 5989

	/* avoid races with drain_pages()  */
	local_irq_save(flags);
	if (zone->pageset != &boot_pageset) {
5990 5991 5992 5993
		for_each_online_cpu(cpu) {
			pset = per_cpu_ptr(zone->pageset, cpu);
			drain_zonestat(zone, pset);
		}
5994 5995 5996 5997 5998 5999
		free_percpu(zone->pageset);
		zone->pageset = &boot_pageset;
	}
	local_irq_restore(flags);
}

6000
#ifdef CONFIG_MEMORY_HOTREMOVE
K
KAMEZAWA Hiroyuki 已提交
6001 6002 6003 6004 6005 6006 6007 6008 6009 6010 6011 6012 6013 6014 6015 6016 6017 6018 6019 6020 6021 6022 6023 6024 6025 6026
/*
 * 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);
6027 6028 6029 6030 6031 6032 6033 6034 6035 6036
		/*
		 * The HWPoisoned page may be not in buddy system, and
		 * page_count() is not 0.
		 */
		if (unlikely(!PageBuddy(page) && PageHWPoison(page))) {
			pfn++;
			SetPageReserved(page);
			continue;
		}

K
KAMEZAWA Hiroyuki 已提交
6037 6038 6039 6040 6041 6042 6043 6044 6045 6046 6047 6048 6049 6050 6051 6052 6053
		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--;
		for (i = 0; i < (1 << order); i++)
			SetPageReserved((page+i));
		pfn += (1 << order);
	}
	spin_unlock_irqrestore(&zone->lock, flags);
}
#endif
6054 6055 6056 6057 6058 6059 6060 6061 6062 6063 6064 6065 6066 6067 6068 6069 6070 6071 6072 6073 6074

#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
6075

A
Andrew Morton 已提交
6076
static const struct trace_print_flags pageflag_names[] = {
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	{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"	},
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#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
	{1UL << PG_compound_lock,	"compound_lock"	},
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#endif
};

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

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	BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS);
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	printk(KERN_ALERT "page flags: %#lx(", flags);

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

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	for (i = 0; i < ARRAY_SIZE(pageflag_names) && flags; i++) {
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		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",
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		page, atomic_read(&page->_count), page_mapcount(page),
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		page->mapping, page->index);
	dump_page_flags(page->flags);
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	mem_cgroup_print_bad_page(page);
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}