page_alloc.c 169.5 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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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);
		}
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		combined_idx = buddy_idx & page_idx;
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Linus Torvalds 已提交
566 567 568 569 570
		page = page + (combined_idx - page_idx);
		page_idx = combined_idx;
		order++;
	}
	set_page_order(page, order);
571 572 573 574 575 576 577 578 579

	/*
	 * 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
	 */
580
	if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
581
		struct page *higher_page, *higher_buddy;
582 583 584
		combined_idx = buddy_idx & page_idx;
		higher_page = page + (combined_idx - page_idx);
		buddy_idx = __find_buddy_index(combined_idx, order + 1);
585
		higher_buddy = higher_page + (buddy_idx - combined_idx);
586 587 588 589 590 591 592 593 594
		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
595 596 597
	zone->free_area[order].nr_free++;
}

N
Nick Piggin 已提交
598
static inline int free_pages_check(struct page *page)
L
Linus Torvalds 已提交
599
{
N
Nick Piggin 已提交
600 601
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
602
		(atomic_read(&page->_count) != 0) |
603 604
		(page->flags & PAGE_FLAGS_CHECK_AT_FREE) |
		(mem_cgroup_bad_page_check(page)))) {
N
Nick Piggin 已提交
605
		bad_page(page);
606
		return 1;
607
	}
608
	reset_page_last_nid(page);
609 610 611
	if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
		page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
	return 0;
L
Linus Torvalds 已提交
612 613 614
}

/*
615
 * Frees a number of pages from the PCP lists
L
Linus Torvalds 已提交
616
 * Assumes all pages on list are in same zone, and of same order.
617
 * count is the number of pages to free.
L
Linus Torvalds 已提交
618 619 620 621 622 623 624
 *
 * 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.
 */
625 626
static void free_pcppages_bulk(struct zone *zone, int count,
					struct per_cpu_pages *pcp)
L
Linus Torvalds 已提交
627
{
628
	int migratetype = 0;
629
	int batch_free = 0;
630
	int to_free = count;
631

N
Nick Piggin 已提交
632
	spin_lock(&zone->lock);
633
	zone->all_unreclaimable = 0;
L
Linus Torvalds 已提交
634
	zone->pages_scanned = 0;
635

636
	while (to_free) {
N
Nick Piggin 已提交
637
		struct page *page;
638 639 640
		struct list_head *list;

		/*
641 642 643 644 645
		 * 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
646 647
		 */
		do {
648
			batch_free++;
649 650 651 652
			if (++migratetype == MIGRATE_PCPTYPES)
				migratetype = 0;
			list = &pcp->lists[migratetype];
		} while (list_empty(list));
N
Nick Piggin 已提交
653

654 655 656 657
		/* This is the only non-empty list. Free them all. */
		if (batch_free == MIGRATE_PCPTYPES)
			batch_free = to_free;

658
		do {
659 660
			int mt;	/* migratetype of the to-be-freed page */

661 662 663
			page = list_entry(list->prev, struct page, lru);
			/* must delete as __free_one_page list manipulates */
			list_del(&page->lru);
664
			mt = get_freepage_migratetype(page);
665
			/* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
666 667
			__free_one_page(page, zone, 0, mt);
			trace_mm_page_pcpu_drain(page, 0, mt);
668 669 670 671 672
			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);
			}
673
		} while (--to_free && --batch_free && !list_empty(list));
L
Linus Torvalds 已提交
674
	}
N
Nick Piggin 已提交
675
	spin_unlock(&zone->lock);
L
Linus Torvalds 已提交
676 677
}

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

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

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

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

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

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

714 715 716 717 718 719
	return true;
}

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

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

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

733 734 735 736 737 738 739
/*
 * 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.
 */
740
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
741
{
742 743
	unsigned int nr_pages = 1 << order;
	unsigned int loop;
744

745 746 747 748 749 750 751 752
	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);
753
	}
754

755
	page_zone(page)->managed_pages += 1 << order;
756 757
	set_page_refcounted(page);
	__free_pages(page, order);
758 759
}

760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777
#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
778 779 780 781 782 783 784 785 786 787 788 789 790

/*
 * 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.
 *
791
 * -- nyc
L
Linus Torvalds 已提交
792
 */
N
Nick Piggin 已提交
793
static inline void expand(struct zone *zone, struct page *page,
794 795
	int low, int high, struct free_area *area,
	int migratetype)
L
Linus Torvalds 已提交
796 797 798 799 800 801 802
{
	unsigned long size = 1 << high;

	while (high > low) {
		area--;
		high--;
		size >>= 1;
N
Nick Piggin 已提交
803
		VM_BUG_ON(bad_range(zone, &page[size]));
804 805 806 807 808 809 810 811 812 813 814 815 816

#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 */
817 818
			__mod_zone_freepage_state(zone, -(1 << high),
						  migratetype);
819 820 821
			continue;
		}
#endif
822
		list_add(&page[size].lru, &area->free_list[migratetype]);
L
Linus Torvalds 已提交
823 824 825 826 827 828 829 830
		area->nr_free++;
		set_page_order(&page[size], high);
	}
}

/*
 * This page is about to be returned from the page allocator
 */
831
static inline int check_new_page(struct page *page)
L
Linus Torvalds 已提交
832
{
N
Nick Piggin 已提交
833 834
	if (unlikely(page_mapcount(page) |
		(page->mapping != NULL)  |
835
		(atomic_read(&page->_count) != 0)  |
836 837
		(page->flags & PAGE_FLAGS_CHECK_AT_PREP) |
		(mem_cgroup_bad_page_check(page)))) {
N
Nick Piggin 已提交
838
		bad_page(page);
839
		return 1;
840
	}
841 842 843 844 845 846 847 848 849 850 851 852
	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;
	}
853

H
Hugh Dickins 已提交
854
	set_page_private(page, 0);
855
	set_page_refcounted(page);
N
Nick Piggin 已提交
856 857

	arch_alloc_page(page, order);
L
Linus Torvalds 已提交
858
	kernel_map_pages(page, 1 << order, 1);
N
Nick Piggin 已提交
859 860 861 862 863 864 865

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

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

866
	return 0;
L
Linus Torvalds 已提交
867 868
}

869 870 871 872
/*
 * Go through the free lists for the given migratetype and remove
 * the smallest available page from the freelists
 */
873 874
static inline
struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899
						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;
}


900 901 902 903
/*
 * This array describes the order lists are fallen back to when
 * the free lists for the desirable migrate type are depleted
 */
904 905 906 907 908 909 910 911 912
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
913 914
	[MIGRATE_RESERVE]     = { MIGRATE_RESERVE }, /* Never used */
	[MIGRATE_ISOLATE]     = { MIGRATE_RESERVE }, /* Never used */
915 916
};

917 918
/*
 * Move the free pages in a range to the free lists of the requested type.
919
 * Note that start_page and end_pages are not aligned on a pageblock
920 921
 * boundary. If alignment is required, use move_freepages_block()
 */
922
int move_freepages(struct zone *zone,
A
Adrian Bunk 已提交
923 924
			  struct page *start_page, struct page *end_page,
			  int migratetype)
925 926 927
{
	struct page *page;
	unsigned long order;
928
	int pages_moved = 0;
929 930 931 932 933 934 935

#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
936
	 * grouping pages by mobility
937 938 939 940 941
	 */
	BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif

	for (page = start_page; page <= end_page;) {
942 943 944
		/* Make sure we are not inadvertently changing nodes */
		VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));

945 946 947 948 949 950 951 952 953 954 955
		if (!pfn_valid_within(page_to_pfn(page))) {
			page++;
			continue;
		}

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

		order = page_order(page);
956 957
		list_move(&page->lru,
			  &zone->free_area[order].free_list[migratetype]);
M
Minchan Kim 已提交
958
		set_freepage_migratetype(page, migratetype);
959
		page += 1 << order;
960
		pages_moved += 1 << order;
961 962
	}

963
	return pages_moved;
964 965
}

966
int move_freepages_block(struct zone *zone, struct page *page,
967
				int migratetype)
968 969 970 971 972
{
	unsigned long start_pfn, end_pfn;
	struct page *start_page, *end_page;

	start_pfn = page_to_pfn(page);
973
	start_pfn = start_pfn & ~(pageblock_nr_pages-1);
974
	start_page = pfn_to_page(start_pfn);
975 976
	end_page = start_page + pageblock_nr_pages - 1;
	end_pfn = start_pfn + pageblock_nr_pages - 1;
977 978 979 980 981 982 983 984 985 986

	/* 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);
}

987 988 989 990 991 992 993 994 995 996 997
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;
	}
}

998
/* Remove an element from the buddy allocator from the fallback list */
999 1000
static inline struct page *
__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
1001 1002 1003 1004 1005 1006 1007 1008 1009
{
	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) {
1010
		for (i = 0;; i++) {
1011 1012
			migratetype = fallbacks[start_migratetype][i];

1013 1014
			/* MIGRATE_RESERVE handled later if necessary */
			if (migratetype == MIGRATE_RESERVE)
1015
				break;
M
Mel Gorman 已提交
1016

1017 1018 1019 1020 1021 1022 1023 1024 1025
			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--;

			/*
1026
			 * If breaking a large block of pages, move all free
1027 1028
			 * pages to the preferred allocation list. If falling
			 * back for a reclaimable kernel allocation, be more
L
Lucas De Marchi 已提交
1029
			 * aggressive about taking ownership of free pages
1030 1031 1032 1033 1034 1035
			 *
			 * 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.
1036
			 */
1037 1038 1039 1040 1041
			if (!is_migrate_cma(migratetype) &&
			    (unlikely(current_order >= pageblock_order / 2) ||
			     start_migratetype == MIGRATE_RECLAIMABLE ||
			     page_group_by_mobility_disabled)) {
				int pages;
1042 1043 1044 1045
				pages = move_freepages_block(zone, page,
								start_migratetype);

				/* Claim the whole block if over half of it is free */
1046 1047
				if (pages >= (1 << (pageblock_order-1)) ||
						page_group_by_mobility_disabled)
1048 1049 1050
					set_pageblock_migratetype(page,
								start_migratetype);

1051
				migratetype = start_migratetype;
1052
			}
1053 1054 1055 1056 1057

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

1058
			/* Take ownership for orders >= pageblock_order */
1059 1060
			if (current_order >= pageblock_order &&
			    !is_migrate_cma(migratetype))
1061
				change_pageblock_range(page, current_order,
1062 1063
							start_migratetype);

1064 1065 1066
			expand(zone, page, order, current_order, area,
			       is_migrate_cma(migratetype)
			     ? migratetype : start_migratetype);
1067 1068 1069 1070

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

1071 1072 1073 1074
			return page;
		}
	}

1075
	return NULL;
1076 1077
}

1078
/*
L
Linus Torvalds 已提交
1079 1080 1081
 * Do the hard work of removing an element from the buddy allocator.
 * Call me with the zone->lock already held.
 */
1082 1083
static struct page *__rmqueue(struct zone *zone, unsigned int order,
						int migratetype)
L
Linus Torvalds 已提交
1084 1085 1086
{
	struct page *page;

1087
retry_reserve:
1088
	page = __rmqueue_smallest(zone, order, migratetype);
1089

1090
	if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
1091
		page = __rmqueue_fallback(zone, order, migratetype);
1092

1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103
		/*
		 * 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;
		}
	}

1104
	trace_mm_page_alloc_zone_locked(page, order, migratetype);
1105
	return page;
L
Linus Torvalds 已提交
1106 1107
}

1108
/*
L
Linus Torvalds 已提交
1109 1110 1111 1112
 * 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.
 */
1113
static int rmqueue_bulk(struct zone *zone, unsigned int order,
1114
			unsigned long count, struct list_head *list,
1115
			int migratetype, int cold)
L
Linus Torvalds 已提交
1116
{
1117
	int mt = migratetype, i;
1118

N
Nick Piggin 已提交
1119
	spin_lock(&zone->lock);
L
Linus Torvalds 已提交
1120
	for (i = 0; i < count; ++i) {
1121
		struct page *page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1122
		if (unlikely(page == NULL))
L
Linus Torvalds 已提交
1123
			break;
1124 1125 1126 1127 1128 1129 1130 1131 1132 1133

		/*
		 * 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.
		 */
1134 1135 1136 1137
		if (likely(cold == 0))
			list_add(&page->lru, list);
		else
			list_add_tail(&page->lru, list);
1138 1139 1140 1141 1142
		if (IS_ENABLED(CONFIG_CMA)) {
			mt = get_pageblock_migratetype(page);
			if (!is_migrate_cma(mt) && mt != MIGRATE_ISOLATE)
				mt = migratetype;
		}
1143
		set_freepage_migratetype(page, mt);
1144
		list = &page->lru;
1145 1146 1147
		if (is_migrate_cma(mt))
			__mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
					      -(1 << order));
L
Linus Torvalds 已提交
1148
	}
1149
	__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
N
Nick Piggin 已提交
1150
	spin_unlock(&zone->lock);
N
Nick Piggin 已提交
1151
	return i;
L
Linus Torvalds 已提交
1152 1153
}

1154
#ifdef CONFIG_NUMA
1155
/*
1156 1157 1158 1159
 * Called from the vmstat counter updater to drain pagesets of this
 * currently executing processor on remote nodes after they have
 * expired.
 *
1160 1161
 * Note that this function must be called with the thread pinned to
 * a single processor.
1162
 */
1163
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
1164 1165
{
	unsigned long flags;
1166
	int to_drain;
1167

1168 1169 1170 1171 1172
	local_irq_save(flags);
	if (pcp->count >= pcp->batch)
		to_drain = pcp->batch;
	else
		to_drain = pcp->count;
1173 1174 1175 1176
	if (to_drain > 0) {
		free_pcppages_bulk(zone, to_drain, pcp);
		pcp->count -= to_drain;
	}
1177
	local_irq_restore(flags);
1178 1179 1180
}
#endif

1181 1182 1183 1184 1185 1186 1187 1188
/*
 * 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
1189
{
N
Nick Piggin 已提交
1190
	unsigned long flags;
L
Linus Torvalds 已提交
1191 1192
	struct zone *zone;

1193
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
1194
		struct per_cpu_pageset *pset;
1195
		struct per_cpu_pages *pcp;
L
Linus Torvalds 已提交
1196

1197 1198
		local_irq_save(flags);
		pset = per_cpu_ptr(zone->pageset, cpu);
1199 1200

		pcp = &pset->pcp;
1201 1202 1203 1204
		if (pcp->count) {
			free_pcppages_bulk(zone, pcp->count, pcp);
			pcp->count = 0;
		}
1205
		local_irq_restore(flags);
L
Linus Torvalds 已提交
1206 1207 1208
	}
}

1209 1210 1211 1212 1213 1214 1215 1216 1217
/*
 * 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());
}

/*
1218 1219 1220 1221 1222 1223 1224
 * 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().
1225 1226 1227
 */
void drain_all_pages(void)
{
1228 1229 1230 1231 1232 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
	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);
1259 1260
}

1261
#ifdef CONFIG_HIBERNATION
L
Linus Torvalds 已提交
1262 1263 1264

void mark_free_pages(struct zone *zone)
{
1265 1266
	unsigned long pfn, max_zone_pfn;
	unsigned long flags;
1267
	int order, t;
L
Linus Torvalds 已提交
1268 1269 1270 1271 1272 1273
	struct list_head *curr;

	if (!zone->spanned_pages)
		return;

	spin_lock_irqsave(&zone->lock, flags);
1274 1275 1276 1277 1278 1279

	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);

1280 1281
			if (!swsusp_page_is_forbidden(page))
				swsusp_unset_page_free(page);
1282
		}
L
Linus Torvalds 已提交
1283

1284 1285
	for_each_migratetype_order(order, t) {
		list_for_each(curr, &zone->free_area[order].free_list[t]) {
1286
			unsigned long i;
L
Linus Torvalds 已提交
1287

1288 1289
			pfn = page_to_pfn(list_entry(curr, struct page, lru));
			for (i = 0; i < (1UL << order); i++)
1290
				swsusp_set_page_free(pfn_to_page(pfn + i));
1291
		}
1292
	}
L
Linus Torvalds 已提交
1293 1294
	spin_unlock_irqrestore(&zone->lock, flags);
}
1295
#endif /* CONFIG_PM */
L
Linus Torvalds 已提交
1296 1297 1298

/*
 * Free a 0-order page
L
Li Hong 已提交
1299
 * cold == 1 ? free a cold page : free a hot page
L
Linus Torvalds 已提交
1300
 */
L
Li Hong 已提交
1301
void free_hot_cold_page(struct page *page, int cold)
L
Linus Torvalds 已提交
1302 1303 1304 1305
{
	struct zone *zone = page_zone(page);
	struct per_cpu_pages *pcp;
	unsigned long flags;
1306
	int migratetype;
L
Linus Torvalds 已提交
1307

1308
	if (!free_pages_prepare(page, 0))
1309 1310
		return;

1311
	migratetype = get_pageblock_migratetype(page);
1312
	set_freepage_migratetype(page, migratetype);
L
Linus Torvalds 已提交
1313
	local_irq_save(flags);
1314
	__count_vm_event(PGFREE);
1315

1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330
	/*
	 * 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;
	}

1331
	pcp = &this_cpu_ptr(zone->pageset)->pcp;
1332
	if (cold)
1333
		list_add_tail(&page->lru, &pcp->lists[migratetype]);
1334
	else
1335
		list_add(&page->lru, &pcp->lists[migratetype]);
L
Linus Torvalds 已提交
1336
	pcp->count++;
N
Nick Piggin 已提交
1337
	if (pcp->count >= pcp->high) {
1338
		free_pcppages_bulk(zone, pcp->batch, pcp);
N
Nick Piggin 已提交
1339 1340
		pcp->count -= pcp->batch;
	}
1341 1342

out:
L
Linus Torvalds 已提交
1343 1344 1345
	local_irq_restore(flags);
}

1346 1347 1348 1349 1350 1351 1352 1353
/*
 * 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) {
1354
		trace_mm_page_free_batched(page, cold);
1355 1356 1357 1358
		free_hot_cold_page(page, cold);
	}
}

N
Nick Piggin 已提交
1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370
/*
 * 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
1371 1372
	VM_BUG_ON(PageCompound(page));
	VM_BUG_ON(!page_count(page));
1373 1374 1375 1376 1377 1378 1379 1380 1381 1382

#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

1383 1384
	for (i = 1; i < (1 << order); i++)
		set_page_refcounted(page + i);
N
Nick Piggin 已提交
1385 1386
}

1387
static int __isolate_free_page(struct page *page, unsigned int order)
1388 1389 1390
{
	unsigned long watermark;
	struct zone *zone;
1391
	int mt;
1392 1393 1394 1395

	BUG_ON(!PageBuddy(page));

	zone = page_zone(page);
1396
	mt = get_pageblock_migratetype(page);
1397

1398 1399 1400 1401 1402 1403
	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;

1404
		__mod_zone_freepage_state(zone, -(1UL << order), mt);
1405
	}
1406 1407 1408 1409 1410

	/* Remove page from free list */
	list_del(&page->lru);
	zone->free_area[order].nr_free--;
	rmv_page_order(page);
1411

1412
	/* Set the pageblock if the isolated page is at least a pageblock */
1413 1414
	if (order >= pageblock_order - 1) {
		struct page *endpage = page + (1 << order) - 1;
1415 1416 1417 1418 1419 1420
		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);
		}
1421 1422
	}

1423
	return 1UL << order;
1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442
}

/*
 * 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;

	order = page_order(page);

1443
	nr_pages = __isolate_free_page(page, order);
1444 1445 1446 1447 1448 1449 1450
	if (!nr_pages)
		return 0;

	/* Split into individual pages */
	set_page_refcounted(page);
	split_page(page, order);
	return nr_pages;
1451 1452
}

L
Linus Torvalds 已提交
1453 1454 1455 1456 1457
/*
 * 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.
 */
1458 1459
static inline
struct page *buffered_rmqueue(struct zone *preferred_zone,
1460 1461
			struct zone *zone, int order, gfp_t gfp_flags,
			int migratetype)
L
Linus Torvalds 已提交
1462 1463
{
	unsigned long flags;
1464
	struct page *page;
L
Linus Torvalds 已提交
1465 1466
	int cold = !!(gfp_flags & __GFP_COLD);

1467
again:
N
Nick Piggin 已提交
1468
	if (likely(order == 0)) {
L
Linus Torvalds 已提交
1469
		struct per_cpu_pages *pcp;
1470
		struct list_head *list;
L
Linus Torvalds 已提交
1471 1472

		local_irq_save(flags);
1473 1474
		pcp = &this_cpu_ptr(zone->pageset)->pcp;
		list = &pcp->lists[migratetype];
1475
		if (list_empty(list)) {
1476
			pcp->count += rmqueue_bulk(zone, 0,
1477
					pcp->batch, list,
1478
					migratetype, cold);
1479
			if (unlikely(list_empty(list)))
1480
				goto failed;
1481
		}
1482

1483 1484 1485 1486 1487
		if (cold)
			page = list_entry(list->prev, struct page, lru);
		else
			page = list_entry(list->next, struct page, lru);

1488 1489
		list_del(&page->lru);
		pcp->count--;
R
Rohit Seth 已提交
1490
	} else {
1491 1492 1493 1494 1495 1496 1497 1498
		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
1499
			 * allocate greater than order-1 page units with
1500 1501
			 * __GFP_NOFAIL.
			 */
1502
			WARN_ON_ONCE(order > 1);
1503
		}
L
Linus Torvalds 已提交
1504
		spin_lock_irqsave(&zone->lock, flags);
1505
		page = __rmqueue(zone, order, migratetype);
N
Nick Piggin 已提交
1506 1507 1508
		spin_unlock(&zone->lock);
		if (!page)
			goto failed;
1509 1510
		__mod_zone_freepage_state(zone, -(1 << order),
					  get_pageblock_migratetype(page));
L
Linus Torvalds 已提交
1511 1512
	}

1513
	__count_zone_vm_events(PGALLOC, zone, 1 << order);
A
Andi Kleen 已提交
1514
	zone_statistics(preferred_zone, zone, gfp_flags);
N
Nick Piggin 已提交
1515
	local_irq_restore(flags);
L
Linus Torvalds 已提交
1516

N
Nick Piggin 已提交
1517
	VM_BUG_ON(bad_range(zone, page));
N
Nick Piggin 已提交
1518
	if (prep_new_page(page, order, gfp_flags))
N
Nick Piggin 已提交
1519
		goto again;
L
Linus Torvalds 已提交
1520
	return page;
N
Nick Piggin 已提交
1521 1522 1523 1524

failed:
	local_irq_restore(flags);
	return NULL;
L
Linus Torvalds 已提交
1525 1526
}

1527 1528
#ifdef CONFIG_FAIL_PAGE_ALLOC

1529
static struct {
1530 1531 1532 1533
	struct fault_attr attr;

	u32 ignore_gfp_highmem;
	u32 ignore_gfp_wait;
1534
	u32 min_order;
1535 1536
} fail_page_alloc = {
	.attr = FAULT_ATTR_INITIALIZER,
1537 1538
	.ignore_gfp_wait = 1,
	.ignore_gfp_highmem = 1,
1539
	.min_order = 1,
1540 1541 1542 1543 1544 1545 1546 1547
};

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);

1548
static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1549
{
1550
	if (order < fail_page_alloc.min_order)
1551
		return false;
1552
	if (gfp_mask & __GFP_NOFAIL)
1553
		return false;
1554
	if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
1555
		return false;
1556
	if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
1557
		return false;
1558 1559 1560 1561 1562 1563 1564 1565

	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
1566
	umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
1567 1568
	struct dentry *dir;

1569 1570 1571 1572
	dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
					&fail_page_alloc.attr);
	if (IS_ERR(dir))
		return PTR_ERR(dir);
1573

1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585
	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:
1586
	debugfs_remove_recursive(dir);
1587

1588
	return -ENOMEM;
1589 1590 1591 1592 1593 1594 1595 1596
}

late_initcall(fail_page_alloc_debugfs);

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

#else /* CONFIG_FAIL_PAGE_ALLOC */

1597
static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
1598
{
1599
	return false;
1600 1601 1602 1603
}

#endif /* CONFIG_FAIL_PAGE_ALLOC */

L
Linus Torvalds 已提交
1604
/*
1605
 * Return true if free pages are above 'mark'. This takes into account the order
L
Linus Torvalds 已提交
1606 1607
 * of the allocation.
 */
1608 1609
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
1610 1611
{
	/* free_pages my go negative - that's OK */
1612
	long min = mark;
1613
	long lowmem_reserve = z->lowmem_reserve[classzone_idx];
L
Linus Torvalds 已提交
1614 1615
	int o;

1616
	free_pages -= (1 << order) - 1;
R
Rohit Seth 已提交
1617
	if (alloc_flags & ALLOC_HIGH)
L
Linus Torvalds 已提交
1618
		min -= min / 2;
R
Rohit Seth 已提交
1619
	if (alloc_flags & ALLOC_HARDER)
L
Linus Torvalds 已提交
1620
		min -= min / 4;
1621 1622 1623 1624 1625
#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
1626
	if (free_pages <= min + lowmem_reserve)
1627
		return false;
L
Linus Torvalds 已提交
1628 1629 1630 1631 1632 1633 1634 1635
	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)
1636
			return false;
L
Linus Torvalds 已提交
1637
	}
1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657
	return true;
}

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);

	return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
								free_pages);
L
Linus Torvalds 已提交
1658 1659
}

1660 1661 1662 1663 1664 1665
#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
1666
 * that have to skip over a lot of full or unallowed zones.
1667 1668 1669
 *
 * If the zonelist cache is present in the passed in zonelist, then
 * returns a pointer to the allowed node mask (either the current
1670
 * tasks mems_allowed, or node_states[N_MEMORY].)
1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691
 *
 * 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
1692
	if (time_after(jiffies, zlc->last_full_zap + HZ)) {
1693 1694 1695 1696 1697 1698
		bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
		zlc->last_full_zap = jiffies;
	}

	allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
					&cpuset_current_mems_allowed :
1699
					&node_states[N_MEMORY];
1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724
	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.
 */
1725
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1726 1727 1728 1729 1730 1731 1732 1733 1734 1735
						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;

1736
	i = z - zonelist->_zonerefs;
1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747
	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.
 */
1748
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1749 1750 1751 1752 1753 1754 1755 1756
{
	struct zonelist_cache *zlc;	/* cached zonelist speedup info */
	int i;				/* index of *z in zonelist zones */

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

1757
	i = z - zonelist->_zonerefs;
1758 1759 1760 1761

	set_bit(i, zlc->fullzones);
}

1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776
/*
 * 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);
}

1777 1778 1779 1780 1781 1782 1783 1784 1785 1786
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)
1787
		if (node_distance(nid, i) <= RECLAIM_DISTANCE)
1788
			node_set(i, NODE_DATA(nid)->reclaim_nodes);
1789
		else
1790 1791 1792
			zone_reclaim_mode = 1;
}

1793 1794 1795 1796 1797 1798 1799
#else	/* CONFIG_NUMA */

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

1800
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
1801 1802 1803 1804 1805
				nodemask_t *allowednodes)
{
	return 1;
}

1806
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
1807 1808
{
}
1809 1810 1811 1812

static void zlc_clear_zones_full(struct zonelist *zonelist)
{
}
1813 1814 1815 1816 1817 1818 1819 1820 1821

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

static inline void init_zone_allows_reclaim(int nid)
{
}
1822 1823
#endif	/* CONFIG_NUMA */

R
Rohit Seth 已提交
1824
/*
1825
 * get_page_from_freelist goes through the zonelist trying to allocate
R
Rohit Seth 已提交
1826 1827 1828
 * a page.
 */
static struct page *
1829
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
1830
		struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
1831
		struct zone *preferred_zone, int migratetype)
M
Martin Hicks 已提交
1832
{
1833
	struct zoneref *z;
R
Rohit Seth 已提交
1834
	struct page *page = NULL;
1835
	int classzone_idx;
1836
	struct zone *zone;
1837 1838 1839
	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 */
1840

1841
	classzone_idx = zone_idx(preferred_zone);
1842
zonelist_scan:
R
Rohit Seth 已提交
1843
	/*
1844
	 * Scan zonelist, looking for a zone with enough free.
R
Rohit Seth 已提交
1845 1846
	 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
	 */
1847 1848
	for_each_zone_zonelist_nodemask(zone, z, zonelist,
						high_zoneidx, nodemask) {
1849
		if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
1850 1851
			!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;
R
Rohit Seth 已提交
1852
		if ((alloc_flags & ALLOC_CPUSET) &&
1853
			!cpuset_zone_allowed_softwall(zone, gfp_mask))
1854
				continue;
1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883
		/*
		 * 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
1884

1885
		BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
R
Rohit Seth 已提交
1886
		if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
1887
			unsigned long mark;
1888 1889
			int ret;

1890
			mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
1891 1892 1893 1894
			if (zone_watermark_ok(zone, order, mark,
				    classzone_idx, alloc_flags))
				goto try_this_zone;

1895 1896
			if (IS_ENABLED(CONFIG_NUMA) &&
					!did_zlc_setup && nr_online_nodes > 1) {
1897 1898 1899 1900 1901 1902 1903 1904 1905 1906
				/*
				 * 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;
			}

1907 1908
			if (zone_reclaim_mode == 0 ||
			    !zone_allows_reclaim(preferred_zone, zone))
1909 1910
				goto this_zone_full;

1911 1912 1913 1914
			/*
			 * As we may have just activated ZLC, check if the first
			 * eligible zone has failed zone_reclaim recently.
			 */
1915
			if (IS_ENABLED(CONFIG_NUMA) && zlc_active &&
1916 1917 1918
				!zlc_zone_worth_trying(zonelist, z, allowednodes))
				continue;

1919 1920 1921 1922
			ret = zone_reclaim(zone, gfp_mask, order);
			switch (ret) {
			case ZONE_RECLAIM_NOSCAN:
				/* did not scan */
1923
				continue;
1924 1925
			case ZONE_RECLAIM_FULL:
				/* scanned but unreclaimable */
1926
				continue;
1927 1928 1929 1930
			default:
				/* did we reclaim enough */
				if (!zone_watermark_ok(zone, order, mark,
						classzone_idx, alloc_flags))
1931
					goto this_zone_full;
1932
			}
R
Rohit Seth 已提交
1933 1934
		}

1935
try_this_zone:
1936 1937
		page = buffered_rmqueue(preferred_zone, zone, order,
						gfp_mask, migratetype);
1938
		if (page)
R
Rohit Seth 已提交
1939
			break;
1940
this_zone_full:
1941
		if (IS_ENABLED(CONFIG_NUMA))
1942
			zlc_mark_zone_full(zonelist, z);
1943
	}
1944

1945
	if (unlikely(IS_ENABLED(CONFIG_NUMA) && page == NULL && zlc_active)) {
1946 1947 1948 1949
		/* Disable zlc cache for second zonelist scan */
		zlc_active = 0;
		goto zonelist_scan;
	}
1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960

	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
1961
	return page;
M
Martin Hicks 已提交
1962 1963
}

1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977
/*
 * 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;
}

1978 1979 1980 1981 1982 1983 1984 1985
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;

1986 1987
	if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
	    debug_guardpage_minorder() > 0)
1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
		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
2003 2004 2005
		struct va_format vaf;
		va_list args;

2006
		va_start(args, fmt);
J
Joe Perches 已提交
2007 2008 2009 2010 2011 2012

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

		pr_warn("%pV", &vaf);

2013 2014 2015
		va_end(args);
	}

J
Joe Perches 已提交
2016 2017
	pr_warn("%s: page allocation failure: order:%d, mode:0x%x\n",
		current->comm, order, gfp_mask);
2018 2019 2020 2021 2022 2023

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

2024 2025
static inline int
should_alloc_retry(gfp_t gfp_mask, unsigned int order,
2026
				unsigned long did_some_progress,
2027
				unsigned long pages_reclaimed)
L
Linus Torvalds 已提交
2028
{
2029 2030 2031
	/* Do not loop if specifically requested */
	if (gfp_mask & __GFP_NORETRY)
		return 0;
L
Linus Torvalds 已提交
2032

2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044
	/* 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;

2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061
	/*
	 * 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;
2062

2063 2064
	return 0;
}
2065

2066 2067 2068
static inline struct page *
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
2069 2070
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
2071 2072 2073 2074
{
	struct page *page;

	/* Acquire the OOM killer lock for the zones in zonelist */
2075
	if (!try_set_zonelist_oom(zonelist, gfp_mask)) {
2076
		schedule_timeout_uninterruptible(1);
L
Linus Torvalds 已提交
2077 2078
		return NULL;
	}
2079

2080 2081 2082 2083 2084 2085 2086
	/*
	 * 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,
2087
		ALLOC_WMARK_HIGH|ALLOC_CPUSET,
2088
		preferred_zone, migratetype);
R
Rohit Seth 已提交
2089
	if (page)
2090 2091
		goto out;

2092 2093 2094 2095
	if (!(gfp_mask & __GFP_NOFAIL)) {
		/* The OOM killer will not help higher order allocs */
		if (order > PAGE_ALLOC_COSTLY_ORDER)
			goto out;
2096 2097 2098
		/* The OOM killer does not needlessly kill tasks for lowmem */
		if (high_zoneidx < ZONE_NORMAL)
			goto out;
2099 2100 2101 2102 2103 2104 2105 2106 2107 2108
		/*
		 * 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;
	}
2109
	/* Exhausted what can be done so it's blamo time */
2110
	out_of_memory(zonelist, gfp_mask, order, nodemask, false);
2111 2112 2113 2114 2115 2116

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

2117 2118 2119 2120 2121 2122
#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,
2123
	int migratetype, bool sync_migration,
2124
	bool *contended_compaction, bool *deferred_compaction,
2125
	unsigned long *did_some_progress)
2126
{
2127
	if (!order)
2128 2129
		return NULL;

2130
	if (compaction_deferred(preferred_zone, order)) {
2131 2132 2133 2134
		*deferred_compaction = true;
		return NULL;
	}

2135
	current->flags |= PF_MEMALLOC;
2136
	*did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
2137
						nodemask, sync_migration,
2138
						contended_compaction);
2139
	current->flags &= ~PF_MEMALLOC;
2140

2141
	if (*did_some_progress != COMPACT_SKIPPED) {
2142 2143
		struct page *page;

2144 2145 2146 2147 2148 2149
		/* 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,
2150 2151
				alloc_flags & ~ALLOC_NO_WATERMARKS,
				preferred_zone, migratetype);
2152
		if (page) {
2153
			preferred_zone->compact_blockskip_flush = false;
2154 2155
			preferred_zone->compact_considered = 0;
			preferred_zone->compact_defer_shift = 0;
2156 2157
			if (order >= preferred_zone->compact_order_failed)
				preferred_zone->compact_order_failed = order + 1;
2158 2159 2160 2161 2162 2163 2164 2165 2166 2167
			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);
2168 2169 2170 2171 2172 2173

		/*
		 * As async compaction considers a subset of pageblocks, only
		 * defer if the failure was a sync compaction failure.
		 */
		if (sync_migration)
2174
			defer_compaction(preferred_zone, order);
2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185

		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,
2186
	int migratetype, bool sync_migration,
2187
	bool *contended_compaction, bool *deferred_compaction,
2188
	unsigned long *did_some_progress)
2189 2190 2191 2192 2193
{
	return NULL;
}
#endif /* CONFIG_COMPACTION */

2194 2195 2196 2197
/* Perform direct synchronous page reclaim */
static int
__perform_reclaim(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist,
		  nodemask_t *nodemask)
2198 2199
{
	struct reclaim_state reclaim_state;
2200
	int progress;
2201 2202 2203 2204 2205

	cond_resched();

	/* We now go into synchronous reclaim */
	cpuset_memory_pressure_bump();
2206
	current->flags |= PF_MEMALLOC;
2207 2208
	lockdep_set_current_reclaim_state(gfp_mask);
	reclaim_state.reclaimed_slab = 0;
2209
	current->reclaim_state = &reclaim_state;
2210

2211
	progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
2212

2213
	current->reclaim_state = NULL;
2214
	lockdep_clear_current_reclaim_state();
2215
	current->flags &= ~PF_MEMALLOC;
2216 2217 2218

	cond_resched();

2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233
	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);
2234 2235
	if (unlikely(!(*did_some_progress)))
		return NULL;
2236

2237
	/* After successful reclaim, reconsider all zones for allocation */
2238
	if (IS_ENABLED(CONFIG_NUMA))
2239 2240
		zlc_clear_zones_full(zonelist);

2241 2242
retry:
	page = get_page_from_freelist(gfp_mask, nodemask, order,
2243
					zonelist, high_zoneidx,
2244 2245
					alloc_flags & ~ALLOC_NO_WATERMARKS,
					preferred_zone, migratetype);
2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256

	/*
	 * 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;
	}

2257 2258 2259
	return page;
}

L
Linus Torvalds 已提交
2260
/*
2261 2262
 * 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
2263
 */
2264 2265 2266
static inline struct page *
__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
2267 2268
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
2269 2270 2271 2272 2273
{
	struct page *page;

	do {
		page = get_page_from_freelist(gfp_mask, nodemask, order,
2274
			zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
2275
			preferred_zone, migratetype);
2276 2277

		if (!page && gfp_mask & __GFP_NOFAIL)
2278
			wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
2279 2280 2281 2282 2283 2284 2285
	} while (!page && (gfp_mask & __GFP_NOFAIL));

	return page;
}

static inline
void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
2286 2287
						enum zone_type high_zoneidx,
						enum zone_type classzone_idx)
L
Linus Torvalds 已提交
2288
{
2289 2290
	struct zoneref *z;
	struct zone *zone;
L
Linus Torvalds 已提交
2291

2292
	for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
2293
		wakeup_kswapd(zone, order, classzone_idx);
2294
}
2295

2296 2297 2298 2299 2300
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
2301

2302
	/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
2303
	BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH);
2304

2305 2306 2307 2308 2309 2310
	/*
	 * 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).
	 */
2311
	alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
L
Linus Torvalds 已提交
2312

2313
	if (!wait) {
2314 2315 2316 2317 2318 2319
		/*
		 * Not worth trying to allocate harder for
		 * __GFP_NOMEMALLOC even if it can't schedule.
		 */
		if  (!(gfp_mask & __GFP_NOMEMALLOC))
			alloc_flags |= ALLOC_HARDER;
2320
		/*
2321 2322
		 * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
		 * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
2323
		 */
2324
		alloc_flags &= ~ALLOC_CPUSET;
2325
	} else if (unlikely(rt_task(current)) && !in_interrupt())
2326 2327
		alloc_flags |= ALLOC_HARDER;

2328 2329 2330
	if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
		if (gfp_mask & __GFP_MEMALLOC)
			alloc_flags |= ALLOC_NO_WATERMARKS;
2331 2332 2333 2334 2335
		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))))
2336
			alloc_flags |= ALLOC_NO_WATERMARKS;
L
Linus Torvalds 已提交
2337
	}
2338 2339 2340 2341
#ifdef CONFIG_CMA
	if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
		alloc_flags |= ALLOC_CMA;
#endif
2342 2343 2344
	return alloc_flags;
}

2345 2346
bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
{
2347
	return !!(gfp_to_alloc_flags(gfp_mask) & ALLOC_NO_WATERMARKS);
2348 2349
}

2350 2351 2352
static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
	struct zonelist *zonelist, enum zone_type high_zoneidx,
2353 2354
	nodemask_t *nodemask, struct zone *preferred_zone,
	int migratetype)
2355 2356 2357 2358 2359 2360
{
	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;
2361
	bool sync_migration = false;
2362
	bool deferred_compaction = false;
2363
	bool contended_compaction = false;
L
Linus Torvalds 已提交
2364

2365 2366 2367 2368 2369 2370
	/*
	 * 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.
	 */
2371 2372
	if (order >= MAX_ORDER) {
		WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
2373
		return NULL;
2374
	}
L
Linus Torvalds 已提交
2375

2376 2377 2378 2379 2380 2381 2382 2383
	/*
	 * 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.
	 */
2384 2385
	if (IS_ENABLED(CONFIG_NUMA) &&
			(gfp_mask & GFP_THISNODE) == GFP_THISNODE)
2386 2387
		goto nopage;

2388
restart:
2389 2390 2391
	if (!(gfp_mask & __GFP_NO_KSWAPD))
		wake_all_kswapd(order, zonelist, high_zoneidx,
						zone_idx(preferred_zone));
L
Linus Torvalds 已提交
2392

2393
	/*
R
Rohit Seth 已提交
2394 2395 2396
	 * 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.
2397
	 */
2398
	alloc_flags = gfp_to_alloc_flags(gfp_mask);
L
Linus Torvalds 已提交
2399

2400 2401 2402 2403 2404 2405 2406 2407
	/*
	 * 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);

2408
rebalance:
2409
	/* This is the last chance, in general, before the goto nopage. */
2410
	page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
2411 2412
			high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
			preferred_zone, migratetype);
R
Rohit Seth 已提交
2413 2414
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
2415

2416
	/* Allocate without watermarks if the context allows */
2417
	if (alloc_flags & ALLOC_NO_WATERMARKS) {
2418 2419 2420 2421 2422 2423 2424
		/*
		 * 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);

2425 2426 2427
		page = __alloc_pages_high_priority(gfp_mask, order,
				zonelist, high_zoneidx, nodemask,
				preferred_zone, migratetype);
2428
		if (page) {
2429
			goto got_pg;
2430
		}
L
Linus Torvalds 已提交
2431 2432 2433 2434 2435 2436
	}

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

2437
	/* Avoid recursion of direct reclaim */
2438
	if (current->flags & PF_MEMALLOC)
2439 2440
		goto nopage;

2441 2442 2443 2444
	/* Avoid allocations with no watermarks from looping endlessly */
	if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
		goto nopage;

2445 2446 2447 2448
	/*
	 * Try direct compaction. The first pass is asynchronous. Subsequent
	 * attempts after direct reclaim are synchronous
	 */
2449 2450 2451 2452
	page = __alloc_pages_direct_compact(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
					alloc_flags, preferred_zone,
2453
					migratetype, sync_migration,
2454
					&contended_compaction,
2455 2456
					&deferred_compaction,
					&did_some_progress);
2457 2458
	if (page)
		goto got_pg;
2459
	sync_migration = true;
2460

2461 2462 2463 2464 2465 2466 2467
	/*
	 * 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) &&
2468
						(gfp_mask & __GFP_NO_KSWAPD))
2469
		goto nopage;
2470

2471 2472 2473 2474
	/* Try direct reclaim and then allocating */
	page = __alloc_pages_direct_reclaim(gfp_mask, order,
					zonelist, high_zoneidx,
					nodemask,
2475
					alloc_flags, preferred_zone,
2476
					migratetype, &did_some_progress);
2477 2478
	if (page)
		goto got_pg;
L
Linus Torvalds 已提交
2479

2480
	/*
2481 2482
	 * If we failed to make any progress reclaiming, then we are
	 * running out of options and have to consider going OOM
2483
	 */
2484 2485
	if (!did_some_progress) {
		if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
2486 2487
			if (oom_killer_disabled)
				goto nopage;
2488 2489 2490 2491
			/* Coredumps can quickly deplete all memory reserves */
			if ((current->flags & PF_DUMPCORE) &&
			    !(gfp_mask & __GFP_NOFAIL))
				goto nopage;
2492 2493
			page = __alloc_pages_may_oom(gfp_mask, order,
					zonelist, high_zoneidx,
2494 2495
					nodemask, preferred_zone,
					migratetype);
2496 2497
			if (page)
				goto got_pg;
L
Linus Torvalds 已提交
2498

2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515
			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;
			}
2516

2517 2518
			goto restart;
		}
L
Linus Torvalds 已提交
2519 2520
	}

2521
	/* Check if we should retry the allocation */
2522
	pages_reclaimed += did_some_progress;
2523 2524
	if (should_alloc_retry(gfp_mask, order, did_some_progress,
						pages_reclaimed)) {
2525
		/* Wait for some write requests to complete then retry */
2526
		wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
L
Linus Torvalds 已提交
2527
		goto rebalance;
2528 2529 2530 2531 2532 2533 2534 2535 2536 2537
	} 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,
2538
					migratetype, sync_migration,
2539
					&contended_compaction,
2540 2541
					&deferred_compaction,
					&did_some_progress);
2542 2543
		if (page)
			goto got_pg;
L
Linus Torvalds 已提交
2544 2545 2546
	}

nopage:
2547
	warn_alloc_failed(gfp_mask, order, NULL);
2548
	return page;
L
Linus Torvalds 已提交
2549
got_pg:
2550 2551
	if (kmemcheck_enabled)
		kmemcheck_pagealloc_alloc(page, order, gfp_mask);
2552

2553
	return page;
L
Linus Torvalds 已提交
2554
}
2555 2556 2557 2558 2559 2560 2561 2562 2563

/*
 * 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);
2564
	struct zone *preferred_zone;
2565
	struct page *page = NULL;
2566
	int migratetype = allocflags_to_migratetype(gfp_mask);
2567
	unsigned int cpuset_mems_cookie;
2568
	int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET;
2569
	struct mem_cgroup *memcg = NULL;
2570

2571 2572
	gfp_mask &= gfp_allowed_mask;

2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587
	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;

2588 2589 2590 2591 2592 2593 2594
	/*
	 * Will only have any effect when __GFP_KMEMCG is set.  This is
	 * verified in the (always inline) callee
	 */
	if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order))
		return NULL;

2595 2596 2597
retry_cpuset:
	cpuset_mems_cookie = get_mems_allowed();

2598
	/* The preferred zone is used for statistics later */
2599 2600 2601
	first_zones_zonelist(zonelist, high_zoneidx,
				nodemask ? : &cpuset_current_mems_allowed,
				&preferred_zone);
2602 2603
	if (!preferred_zone)
		goto out;
2604

2605 2606 2607 2608
#ifdef CONFIG_CMA
	if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
		alloc_flags |= ALLOC_CMA;
#endif
2609
	/* First allocation attempt */
2610
	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
2611
			zonelist, high_zoneidx, alloc_flags,
2612
			preferred_zone, migratetype);
2613 2614
	if (unlikely(!page))
		page = __alloc_pages_slowpath(gfp_mask, order,
2615
				zonelist, high_zoneidx, nodemask,
2616
				preferred_zone, migratetype);
2617

2618
	trace_mm_page_alloc(page, order, gfp_mask, migratetype);
2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629

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;

2630 2631
	memcg_kmem_commit_charge(page, memcg, order);

2632
	return page;
L
Linus Torvalds 已提交
2633
}
2634
EXPORT_SYMBOL(__alloc_pages_nodemask);
L
Linus Torvalds 已提交
2635 2636 2637 2638

/*
 * Common helper functions.
 */
H
Harvey Harrison 已提交
2639
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
L
Linus Torvalds 已提交
2640
{
2641 2642 2643 2644 2645 2646 2647 2648
	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
2649 2650 2651 2652 2653 2654 2655
	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
2656
unsigned long get_zeroed_page(gfp_t gfp_mask)
L
Linus Torvalds 已提交
2657
{
2658
	return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
L
Linus Torvalds 已提交
2659 2660 2661
}
EXPORT_SYMBOL(get_zeroed_page);

H
Harvey Harrison 已提交
2662
void __free_pages(struct page *page, unsigned int order)
L
Linus Torvalds 已提交
2663
{
N
Nick Piggin 已提交
2664
	if (put_page_testzero(page)) {
L
Linus Torvalds 已提交
2665
		if (order == 0)
L
Li Hong 已提交
2666
			free_hot_cold_page(page, 0);
L
Linus Torvalds 已提交
2667 2668 2669 2670 2671 2672 2673
		else
			__free_pages_ok(page, order);
	}
}

EXPORT_SYMBOL(__free_pages);

H
Harvey Harrison 已提交
2674
void free_pages(unsigned long addr, unsigned int order)
L
Linus Torvalds 已提交
2675 2676
{
	if (addr != 0) {
N
Nick Piggin 已提交
2677
		VM_BUG_ON(!virt_addr_valid((void *)addr));
L
Linus Torvalds 已提交
2678 2679 2680 2681 2682 2683
		__free_pages(virt_to_page((void *)addr), order);
	}
}

EXPORT_SYMBOL(free_pages);

2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708
/*
 * __free_memcg_kmem_pages and free_memcg_kmem_pages will free
 * pages allocated with __GFP_KMEMCG.
 *
 * Those pages are accounted to a particular memcg, embedded in the
 * corresponding page_cgroup. To avoid adding a hit in the allocator to search
 * for that information only to find out that it is NULL for users who have no
 * interest in that whatsoever, we provide these functions.
 *
 * The caller knows better which flags it relies on.
 */
void __free_memcg_kmem_pages(struct page *page, unsigned int order)
{
	memcg_kmem_uncharge_pages(page, order);
	__free_pages(page, order);
}

void free_memcg_kmem_pages(unsigned long addr, unsigned int order)
{
	if (addr != 0) {
		VM_BUG_ON(!virt_addr_valid((void *)addr));
		__free_memcg_kmem_pages(virt_to_page((void *)addr), order);
	}
}

A
Andi Kleen 已提交
2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723
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;
}

2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742
/**
 * 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
2743
	return make_alloc_exact(addr, order, size);
2744 2745 2746
}
EXPORT_SYMBOL(alloc_pages_exact);

A
Andi Kleen 已提交
2747 2748 2749
/**
 * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
 *			   pages on a node.
2750
 * @nid: the preferred node ID where memory should be allocated
A
Andi Kleen 已提交
2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768
 * @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);

2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787
/**
 * 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
2788 2789
static unsigned int nr_free_zone_pages(int offset)
{
2790
	struct zoneref *z;
2791 2792
	struct zone *zone;

2793
	/* Just pick one node, since fallback list is circular */
L
Linus Torvalds 已提交
2794 2795
	unsigned int sum = 0;

2796
	struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
L
Linus Torvalds 已提交
2797

2798
	for_each_zone_zonelist(zone, z, zonelist, offset) {
2799
		unsigned long size = zone->present_pages;
2800
		unsigned long high = high_wmark_pages(zone);
2801 2802
		if (size > high)
			sum += size - high;
L
Linus Torvalds 已提交
2803 2804 2805 2806 2807 2808 2809 2810 2811 2812
	}

	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
2813
	return nr_free_zone_pages(gfp_zone(GFP_USER));
L
Linus Torvalds 已提交
2814
}
2815
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
L
Linus Torvalds 已提交
2816 2817 2818 2819 2820 2821

/*
 * Amount of free RAM allocatable within all zones
 */
unsigned int nr_free_pagecache_pages(void)
{
M
Mel Gorman 已提交
2822
	return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
L
Linus Torvalds 已提交
2823
}
2824 2825

static inline void show_node(struct zone *zone)
L
Linus Torvalds 已提交
2826
{
2827
	if (IS_ENABLED(CONFIG_NUMA))
2828
		printk("Node %d ", zone_to_nid(zone));
L
Linus Torvalds 已提交
2829 2830 2831 2832 2833 2834
}

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
2835
	val->freeram = global_page_state(NR_FREE_PAGES);
L
Linus Torvalds 已提交
2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849
	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;
2850
	val->freeram = node_page_state(nid, NR_FREE_PAGES);
2851
#ifdef CONFIG_HIGHMEM
L
Linus Torvalds 已提交
2852
	val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
2853 2854
	val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
			NR_FREE_PAGES);
2855 2856 2857 2858
#else
	val->totalhigh = 0;
	val->freehigh = 0;
#endif
L
Linus Torvalds 已提交
2859 2860 2861 2862
	val->mem_unit = PAGE_SIZE;
}
#endif

2863
/*
2864 2865
 * Determine whether the node should be displayed or not, depending on whether
 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
2866
 */
2867
bool skip_free_areas_node(unsigned int flags, int nid)
2868 2869
{
	bool ret = false;
2870
	unsigned int cpuset_mems_cookie;
2871 2872 2873 2874

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

2875 2876 2877 2878
	do {
		cpuset_mems_cookie = get_mems_allowed();
		ret = !node_isset(nid, cpuset_current_mems_allowed);
	} while (!put_mems_allowed(cpuset_mems_cookie));
2879 2880 2881 2882
out:
	return ret;
}

L
Linus Torvalds 已提交
2883 2884
#define K(x) ((x) << (PAGE_SHIFT-10))

2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909
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
2910 2911 2912 2913
/*
 * 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.
2914 2915
 * Suppresses nodes that are not allowed by current's cpuset if
 * SHOW_MEM_FILTER_NODES is passed.
L
Linus Torvalds 已提交
2916
 */
2917
void show_free_areas(unsigned int filter)
L
Linus Torvalds 已提交
2918
{
2919
	int cpu;
L
Linus Torvalds 已提交
2920 2921
	struct zone *zone;

2922
	for_each_populated_zone(zone) {
2923
		if (skip_free_areas_node(filter, zone_to_nid(zone)))
2924
			continue;
2925 2926
		show_node(zone);
		printk("%s per-cpu:\n", zone->name);
L
Linus Torvalds 已提交
2927

2928
		for_each_online_cpu(cpu) {
L
Linus Torvalds 已提交
2929 2930
			struct per_cpu_pageset *pageset;

2931
			pageset = per_cpu_ptr(zone->pageset, cpu);
L
Linus Torvalds 已提交
2932

2933 2934 2935
			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
2936 2937 2938
		}
	}

K
KOSAKI Motohiro 已提交
2939 2940
	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
2941
		" unevictable:%lu"
2942
		" dirty:%lu writeback:%lu unstable:%lu\n"
2943
		" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
2944 2945
		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
		" free_cma:%lu\n",
2946 2947
		global_page_state(NR_ACTIVE_ANON),
		global_page_state(NR_INACTIVE_ANON),
K
KOSAKI Motohiro 已提交
2948 2949
		global_page_state(NR_ISOLATED_ANON),
		global_page_state(NR_ACTIVE_FILE),
2950
		global_page_state(NR_INACTIVE_FILE),
K
KOSAKI Motohiro 已提交
2951
		global_page_state(NR_ISOLATED_FILE),
L
Lee Schermerhorn 已提交
2952
		global_page_state(NR_UNEVICTABLE),
2953
		global_page_state(NR_FILE_DIRTY),
2954
		global_page_state(NR_WRITEBACK),
2955
		global_page_state(NR_UNSTABLE_NFS),
2956
		global_page_state(NR_FREE_PAGES),
2957 2958
		global_page_state(NR_SLAB_RECLAIMABLE),
		global_page_state(NR_SLAB_UNRECLAIMABLE),
2959
		global_page_state(NR_FILE_MAPPED),
2960
		global_page_state(NR_SHMEM),
2961
		global_page_state(NR_PAGETABLE),
2962 2963
		global_page_state(NR_BOUNCE),
		global_page_state(NR_FREE_CMA_PAGES));
L
Linus Torvalds 已提交
2964

2965
	for_each_populated_zone(zone) {
L
Linus Torvalds 已提交
2966 2967
		int i;

2968
		if (skip_free_areas_node(filter, zone_to_nid(zone)))
2969
			continue;
L
Linus Torvalds 已提交
2970 2971 2972 2973 2974 2975
		show_node(zone);
		printk("%s"
			" free:%lukB"
			" min:%lukB"
			" low:%lukB"
			" high:%lukB"
2976 2977 2978 2979
			" active_anon:%lukB"
			" inactive_anon:%lukB"
			" active_file:%lukB"
			" inactive_file:%lukB"
L
Lee Schermerhorn 已提交
2980
			" unevictable:%lukB"
K
KOSAKI Motohiro 已提交
2981 2982
			" isolated(anon):%lukB"
			" isolated(file):%lukB"
L
Linus Torvalds 已提交
2983
			" present:%lukB"
2984
			" managed:%lukB"
2985 2986 2987 2988
			" mlocked:%lukB"
			" dirty:%lukB"
			" writeback:%lukB"
			" mapped:%lukB"
2989
			" shmem:%lukB"
2990 2991
			" slab_reclaimable:%lukB"
			" slab_unreclaimable:%lukB"
2992
			" kernel_stack:%lukB"
2993 2994 2995
			" pagetables:%lukB"
			" unstable:%lukB"
			" bounce:%lukB"
2996
			" free_cma:%lukB"
2997
			" writeback_tmp:%lukB"
L
Linus Torvalds 已提交
2998 2999 3000 3001
			" pages_scanned:%lu"
			" all_unreclaimable? %s"
			"\n",
			zone->name,
3002
			K(zone_page_state(zone, NR_FREE_PAGES)),
3003 3004 3005
			K(min_wmark_pages(zone)),
			K(low_wmark_pages(zone)),
			K(high_wmark_pages(zone)),
3006 3007 3008 3009
			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
3010
			K(zone_page_state(zone, NR_UNEVICTABLE)),
K
KOSAKI Motohiro 已提交
3011 3012
			K(zone_page_state(zone, NR_ISOLATED_ANON)),
			K(zone_page_state(zone, NR_ISOLATED_FILE)),
L
Linus Torvalds 已提交
3013
			K(zone->present_pages),
3014
			K(zone->managed_pages),
3015 3016 3017 3018
			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)),
3019
			K(zone_page_state(zone, NR_SHMEM)),
3020 3021
			K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
			K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
3022 3023
			zone_page_state(zone, NR_KERNEL_STACK) *
				THREAD_SIZE / 1024,
3024 3025 3026
			K(zone_page_state(zone, NR_PAGETABLE)),
			K(zone_page_state(zone, NR_UNSTABLE_NFS)),
			K(zone_page_state(zone, NR_BOUNCE)),
3027
			K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
3028
			K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
L
Linus Torvalds 已提交
3029
			zone->pages_scanned,
3030
			(zone->all_unreclaimable ? "yes" : "no")
L
Linus Torvalds 已提交
3031 3032 3033 3034 3035 3036 3037
			);
		printk("lowmem_reserve[]:");
		for (i = 0; i < MAX_NR_ZONES; i++)
			printk(" %lu", zone->lowmem_reserve[i]);
		printk("\n");
	}

3038
	for_each_populated_zone(zone) {
3039
 		unsigned long nr[MAX_ORDER], flags, order, total = 0;
3040
		unsigned char types[MAX_ORDER];
L
Linus Torvalds 已提交
3041

3042
		if (skip_free_areas_node(filter, zone_to_nid(zone)))
3043
			continue;
L
Linus Torvalds 已提交
3044 3045 3046 3047 3048
		show_node(zone);
		printk("%s: ", zone->name);

		spin_lock_irqsave(&zone->lock, flags);
		for (order = 0; order < MAX_ORDER; order++) {
3049 3050 3051 3052
			struct free_area *area = &zone->free_area[order];
			int type;

			nr[order] = area->nr_free;
3053
			total += nr[order] << order;
3054 3055 3056 3057 3058 3059

			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
3060 3061
		}
		spin_unlock_irqrestore(&zone->lock, flags);
3062
		for (order = 0; order < MAX_ORDER; order++) {
3063
			printk("%lu*%lukB ", nr[order], K(1UL) << order);
3064 3065 3066
			if (nr[order])
				show_migration_types(types[order]);
		}
L
Linus Torvalds 已提交
3067 3068 3069
		printk("= %lukB\n", K(total));
	}

3070 3071
	printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));

L
Linus Torvalds 已提交
3072 3073 3074
	show_swap_cache_info();
}

3075 3076 3077 3078 3079 3080
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
3081 3082
/*
 * Builds allocation fallback zone lists.
3083 3084
 *
 * Add all populated zones of a node to the zonelist.
L
Linus Torvalds 已提交
3085
 */
3086 3087
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
3088
{
3089 3090
	struct zone *zone;

3091
	BUG_ON(zone_type >= MAX_NR_ZONES);
3092
	zone_type++;
3093 3094

	do {
3095
		zone_type--;
3096
		zone = pgdat->node_zones + zone_type;
3097
		if (populated_zone(zone)) {
3098 3099
			zoneref_set_zone(zone,
				&zonelist->_zonerefs[nr_zones++]);
3100
			check_highest_zone(zone_type);
L
Linus Torvalds 已提交
3101
		}
3102

3103
	} while (zone_type);
3104
	return nr_zones;
L
Linus Torvalds 已提交
3105 3106
}

3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127

/*
 *  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
3128
#ifdef CONFIG_NUMA
3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161
/* 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)
{
3162 3163 3164 3165 3166 3167 3168 3169 3170 3171
	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;
3172 3173 3174 3175 3176 3177 3178
}
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,
3179
		void __user *buffer, size_t *length,
3180 3181 3182 3183
		loff_t *ppos)
{
	char saved_string[NUMA_ZONELIST_ORDER_LEN];
	int ret;
3184
	static DEFINE_MUTEX(zl_order_mutex);
3185

3186
	mutex_lock(&zl_order_mutex);
3187
	if (write)
3188
		strcpy(saved_string, (char*)table->data);
3189
	ret = proc_dostring(table, write, buffer, length, ppos);
3190
	if (ret)
3191
		goto out;
3192 3193 3194 3195 3196 3197 3198 3199 3200
	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;
3201 3202
		} else if (oldval != user_zonelist_order) {
			mutex_lock(&zonelists_mutex);
3203
			build_all_zonelists(NULL, NULL);
3204 3205
			mutex_unlock(&zonelists_mutex);
		}
3206
	}
3207 3208 3209
out:
	mutex_unlock(&zl_order_mutex);
	return ret;
3210 3211 3212
}


3213
#define MAX_NODE_LOAD (nr_online_nodes)
3214 3215
static int node_load[MAX_NUMNODES];

L
Linus Torvalds 已提交
3216
/**
3217
 * find_next_best_node - find the next node that should appear in a given node's fallback list
L
Linus Torvalds 已提交
3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229
 * @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.
 */
3230
static int find_next_best_node(int node, nodemask_t *used_node_mask)
L
Linus Torvalds 已提交
3231
{
3232
	int n, val;
L
Linus Torvalds 已提交
3233 3234
	int min_val = INT_MAX;
	int best_node = -1;
3235
	const struct cpumask *tmp = cpumask_of_node(0);
L
Linus Torvalds 已提交
3236

3237 3238 3239 3240 3241
	/* 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
3242

3243
	for_each_node_state(n, N_MEMORY) {
L
Linus Torvalds 已提交
3244 3245 3246 3247 3248 3249 3250 3251

		/* 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);

3252 3253 3254
		/* Penalize nodes under us ("prefer the next node") */
		val += (n < node);

L
Linus Torvalds 已提交
3255
		/* Give preference to headless and unused nodes */
3256 3257
		tmp = cpumask_of_node(n);
		if (!cpumask_empty(tmp))
L
Linus Torvalds 已提交
3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275
			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;
}

3276 3277 3278 3279 3280 3281 3282

/*
 * 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
3283
{
3284
	int j;
L
Linus Torvalds 已提交
3285
	struct zonelist *zonelist;
3286

3287
	zonelist = &pgdat->node_zonelists[0];
3288
	for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
3289 3290 3291
		;
	j = build_zonelists_node(NODE_DATA(node), zonelist, j,
							MAX_NR_ZONES - 1);
3292 3293
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
3294 3295
}

3296 3297 3298 3299 3300 3301 3302 3303
/*
 * Build gfp_thisnode zonelists
 */
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
	int j;
	struct zonelist *zonelist;

3304 3305
	zonelist = &pgdat->node_zonelists[1];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
3306 3307
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
3308 3309
}

3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324
/*
 * 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;

3325 3326 3327 3328 3329 3330 3331
	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)) {
3332 3333
				zoneref_set_zone(z,
					&zonelist->_zonerefs[pos++]);
3334
				check_highest_zone(zone_type);
3335 3336 3337
			}
		}
	}
3338 3339
	zonelist->_zonerefs[pos].zone = NULL;
	zonelist->_zonerefs[pos].zone_idx = 0;
3340 3341 3342 3343 3344 3345 3346 3347 3348
}

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
3349
         * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
3350 3351
	 * If they are really small and used heavily, the system can fall
	 * into OOM very easily.
3352
	 * This function detect ZONE_DMA/DMA32 size and configures zone order.
3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363
	 */
	/* 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;
3364 3365 3366 3367 3368 3369 3370 3371 3372
			} 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;
3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383
			}
		}
	}
	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.
         */
3384
	average_size = total_size /
3385
				(nodes_weight(node_states[N_MEMORY]) + 1);
3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416
	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
3417
	nodemask_t used_mask;
3418 3419 3420
	int local_node, prev_node;
	struct zonelist *zonelist;
	int order = current_zonelist_order;
L
Linus Torvalds 已提交
3421 3422

	/* initialize zonelists */
3423
	for (i = 0; i < MAX_ZONELISTS; i++) {
L
Linus Torvalds 已提交
3424
		zonelist = pgdat->node_zonelists + i;
3425 3426
		zonelist->_zonerefs[0].zone = NULL;
		zonelist->_zonerefs[0].zone_idx = 0;
L
Linus Torvalds 已提交
3427 3428 3429 3430
	}

	/* NUMA-aware ordering of nodes */
	local_node = pgdat->node_id;
3431
	load = nr_online_nodes;
L
Linus Torvalds 已提交
3432 3433
	prev_node = local_node;
	nodes_clear(used_mask);
3434 3435 3436 3437

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

L
Linus Torvalds 已提交
3438 3439 3440 3441 3442 3443
	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.
		 */
3444 3445
		if (node_distance(local_node, node) !=
		    node_distance(local_node, prev_node))
3446 3447
			node_load[node] = load;

L
Linus Torvalds 已提交
3448 3449
		prev_node = node;
		load--;
3450 3451 3452 3453 3454
		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
3455

3456 3457 3458
	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
3459
	}
3460 3461

	build_thisnode_zonelists(pgdat);
L
Linus Torvalds 已提交
3462 3463
}

3464
/* Construct the zonelist performance cache - see further mmzone.h */
3465
static void build_zonelist_cache(pg_data_t *pgdat)
3466
{
3467 3468
	struct zonelist *zonelist;
	struct zonelist_cache *zlc;
3469
	struct zoneref *z;
3470

3471 3472 3473
	zonelist = &pgdat->node_zonelists[0];
	zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
	bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
3474 3475
	for (z = zonelist->_zonerefs; z->zone; z++)
		zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
3476 3477
}

3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495
#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
3496

L
Linus Torvalds 已提交
3497 3498
#else	/* CONFIG_NUMA */

3499 3500 3501 3502 3503 3504
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
3505
{
3506
	int node, local_node;
3507 3508
	enum zone_type j;
	struct zonelist *zonelist;
L
Linus Torvalds 已提交
3509 3510 3511

	local_node = pgdat->node_id;

3512 3513
	zonelist = &pgdat->node_zonelists[0];
	j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
L
Linus Torvalds 已提交
3514

3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527
	/*
	 * 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
3528
	}
3529 3530 3531 3532 3533 3534 3535
	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);
	}

3536 3537
	zonelist->_zonerefs[j].zone = NULL;
	zonelist->_zonerefs[j].zone_idx = 0;
L
Linus Torvalds 已提交
3538 3539
}

3540
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
3541
static void build_zonelist_cache(pg_data_t *pgdat)
3542
{
3543
	pgdat->node_zonelists[0].zlcache_ptr = NULL;
3544 3545
}

L
Linus Torvalds 已提交
3546 3547
#endif	/* CONFIG_NUMA */

3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564
/*
 * 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);
3565
static void setup_zone_pageset(struct zone *zone);
3566

3567 3568 3569 3570 3571 3572
/*
 * 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);

3573
/* return values int ....just for stop_machine() */
3574
static int __build_all_zonelists(void *data)
L
Linus Torvalds 已提交
3575
{
3576
	int nid;
3577
	int cpu;
3578
	pg_data_t *self = data;
3579

3580 3581 3582
#ifdef CONFIG_NUMA
	memset(node_load, 0, sizeof(node_load));
#endif
3583 3584 3585 3586 3587 3588

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

3589
	for_each_online_node(nid) {
3590 3591 3592 3593
		pg_data_t *pgdat = NODE_DATA(nid);

		build_zonelists(pgdat);
		build_zonelist_cache(pgdat);
3594
	}
3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608

	/*
	 * 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).
	 */
3609
	for_each_possible_cpu(cpu) {
3610 3611
		setup_pageset(&per_cpu(boot_pageset, cpu), 0);

3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625
#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
	}

3626 3627 3628
	return 0;
}

3629 3630 3631 3632
/*
 * Called with zonelists_mutex held always
 * unless system_state == SYSTEM_BOOTING.
 */
3633
void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
3634
{
3635 3636
	set_zonelist_order();

3637
	if (system_state == SYSTEM_BOOTING) {
3638
		__build_all_zonelists(NULL);
3639
		mminit_verify_zonelist();
3640 3641
		cpuset_init_current_mems_allowed();
	} else {
S
Simon Arlott 已提交
3642
		/* we have to stop all cpus to guarantee there is no user
3643
		   of zonelist */
3644
#ifdef CONFIG_MEMORY_HOTPLUG
3645 3646
		if (zone)
			setup_zone_pageset(zone);
3647
#endif
3648
		stop_machine(__build_all_zonelists, pgdat, NULL);
3649 3650
		/* cpuset refresh routine should be here */
	}
3651
	vm_total_pages = nr_free_pagecache_pages();
3652 3653 3654 3655 3656 3657 3658
	/*
	 * 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
	 */
3659
	if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
3660 3661 3662 3663 3664 3665
		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",
3666
			nr_online_nodes,
3667
			zonelist_order_name[current_zonelist_order],
3668
			page_group_by_mobility_disabled ? "off" : "on",
3669 3670 3671 3672
			vm_total_pages);
#ifdef CONFIG_NUMA
	printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
L
Linus Torvalds 已提交
3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687
}

/*
 * 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

3688
#ifndef CONFIG_MEMORY_HOTPLUG
3689
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
L
Linus Torvalds 已提交
3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706
{
	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);
}
3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729
#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
3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742

/*
 * 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))

3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756
/*
 * 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;
}

3757
/*
3758
 * Mark a number of pageblocks as MIGRATE_RESERVE. The number
3759 3760
 * 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
3761 3762 3763 3764 3765
 * 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)
{
3766
	unsigned long start_pfn, pfn, end_pfn, block_end_pfn;
3767
	struct page *page;
3768 3769
	unsigned long block_migratetype;
	int reserve;
3770

3771 3772 3773 3774 3775 3776
	/*
	 * 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.
	 */
3777 3778
	start_pfn = zone->zone_start_pfn;
	end_pfn = start_pfn + zone->spanned_pages;
3779
	start_pfn = roundup(start_pfn, pageblock_nr_pages);
3780
	reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
3781
							pageblock_order;
3782

3783 3784 3785 3786 3787 3788 3789 3790 3791
	/*
	 * 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);

3792
	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
3793 3794 3795 3796
		if (!pfn_valid(pfn))
			continue;
		page = pfn_to_page(pfn);

3797 3798 3799 3800
		/* Watch out for overlapping nodes */
		if (page_to_nid(page) != zone_to_nid(zone))
			continue;

3801 3802
		block_migratetype = get_pageblock_migratetype(page);

3803 3804 3805 3806 3807 3808 3809 3810 3811
		/* 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;
3812

3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827
			/* 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;
			}
3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839
		}

		/*
		 * 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
3840

L
Linus Torvalds 已提交
3841 3842 3843 3844 3845
/*
 * 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.
 */
3846
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
D
Dave Hansen 已提交
3847
		unsigned long start_pfn, enum memmap_context context)
L
Linus Torvalds 已提交
3848 3849
{
	struct page *page;
A
Andy Whitcroft 已提交
3850 3851
	unsigned long end_pfn = start_pfn + size;
	unsigned long pfn;
3852
	struct zone *z;
L
Linus Torvalds 已提交
3853

3854 3855 3856
	if (highest_memmap_pfn < end_pfn - 1)
		highest_memmap_pfn = end_pfn - 1;

3857
	z = &NODE_DATA(nid)->node_zones[zone];
3858
	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
D
Dave Hansen 已提交
3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869
		/*
		 * 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
3870 3871
		page = pfn_to_page(pfn);
		set_page_links(page, zone, nid, pfn);
3872
		mminit_verify_page_links(page, zone, nid, pfn);
3873
		init_page_count(page);
L
Linus Torvalds 已提交
3874
		reset_page_mapcount(page);
3875
		reset_page_last_nid(page);
L
Linus Torvalds 已提交
3876
		SetPageReserved(page);
3877 3878 3879 3880 3881
		/*
		 * 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
3882 3883 3884
		 * kernel allocations are made. Later some blocks near
		 * the start are marked MIGRATE_RESERVE by
		 * setup_zone_migrate_reserve()
3885 3886 3887 3888 3889
		 *
		 * 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.
3890
		 */
3891 3892 3893
		if ((z->zone_start_pfn <= pfn)
		    && (pfn < z->zone_start_pfn + z->spanned_pages)
		    && !(pfn & (pageblock_nr_pages - 1)))
3894
			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
3895

L
Linus Torvalds 已提交
3896 3897 3898 3899
		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))
3900
			set_page_address(page, __va(pfn << PAGE_SHIFT));
L
Linus Torvalds 已提交
3901 3902 3903 3904
#endif
	}
}

3905
static void __meminit zone_init_free_lists(struct zone *zone)
L
Linus Torvalds 已提交
3906
{
3907 3908 3909
	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
3910 3911 3912 3913 3914 3915
		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
3916
	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
L
Linus Torvalds 已提交
3917 3918
#endif

3919
static int __meminit zone_batchsize(struct zone *zone)
3920
{
3921
#ifdef CONFIG_MMU
3922 3923 3924 3925
	int batch;

	/*
	 * The per-cpu-pages pools are set to around 1000th of the
3926
	 * size of the zone.  But no more than 1/2 of a meg.
3927 3928 3929 3930
	 *
	 * OK, so we don't know how big the cache is.  So guess.
	 */
	batch = zone->present_pages / 1024;
3931 3932
	if (batch * PAGE_SIZE > 512 * 1024)
		batch = (512 * 1024) / PAGE_SIZE;
3933 3934 3935 3936 3937
	batch /= 4;		/* We effectively *= 4 below */
	if (batch < 1)
		batch = 1;

	/*
3938 3939 3940
	 * 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.
3941
	 *
3942 3943 3944 3945
	 * 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.
3946
	 */
3947
	batch = rounddown_pow_of_two(batch + batch/2) - 1;
3948

3949
	return batch;
3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966

#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
3967 3968
}

A
Adrian Bunk 已提交
3969
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
3970 3971
{
	struct per_cpu_pages *pcp;
3972
	int migratetype;
3973

3974 3975
	memset(p, 0, sizeof(*p));

3976
	pcp = &p->pcp;
3977 3978 3979
	pcp->count = 0;
	pcp->high = 6 * batch;
	pcp->batch = max(1UL, 1 * batch);
3980 3981
	for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
		INIT_LIST_HEAD(&pcp->lists[migratetype]);
3982 3983
}

3984 3985 3986 3987 3988 3989 3990 3991 3992 3993
/*
 * 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;

3994
	pcp = &p->pcp;
3995 3996 3997 3998 3999 4000
	pcp->high = high;
	pcp->batch = max(1UL, high/4);
	if ((high/4) > (PAGE_SHIFT * 8))
		pcp->batch = PAGE_SHIFT * 8;
}

4001
static void __meminit setup_zone_pageset(struct zone *zone)
4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018
{
	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));
	}
}

4019
/*
4020 4021
 * Allocate per cpu pagesets and initialize them.
 * Before this call only boot pagesets were available.
4022
 */
4023
void __init setup_per_cpu_pageset(void)
4024
{
4025
	struct zone *zone;
4026

4027 4028
	for_each_populated_zone(zone)
		setup_zone_pageset(zone);
4029 4030
}

S
Sam Ravnborg 已提交
4031
static noinline __init_refok
4032
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
4033 4034 4035
{
	int i;
	struct pglist_data *pgdat = zone->zone_pgdat;
4036
	size_t alloc_size;
4037 4038 4039 4040 4041

	/*
	 * The per-page waitqueue mechanism uses hashed waitqueues
	 * per zone.
	 */
4042 4043 4044 4045
	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);
4046 4047 4048
	alloc_size = zone->wait_table_hash_nr_entries
					* sizeof(wait_queue_head_t);

4049
	if (!slab_is_available()) {
4050
		zone->wait_table = (wait_queue_head_t *)
4051
			alloc_bootmem_node_nopanic(pgdat, alloc_size);
4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062
	} 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.
		 */
4063
		zone->wait_table = vmalloc(alloc_size);
4064 4065 4066
	}
	if (!zone->wait_table)
		return -ENOMEM;
4067

4068
	for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
4069
		init_waitqueue_head(zone->wait_table + i);
4070 4071

	return 0;
4072 4073
}

4074
static __meminit void zone_pcp_init(struct zone *zone)
4075
{
4076 4077 4078 4079 4080 4081
	/*
	 * 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;
4082

A
Anton Blanchard 已提交
4083
	if (zone->present_pages)
4084 4085 4086
		printk(KERN_DEBUG "  %s zone: %lu pages, LIFO batch:%u\n",
			zone->name, zone->present_pages,
					 zone_batchsize(zone));
4087 4088
}

4089
int __meminit init_currently_empty_zone(struct zone *zone,
4090
					unsigned long zone_start_pfn,
D
Dave Hansen 已提交
4091 4092
					unsigned long size,
					enum memmap_context context)
4093 4094
{
	struct pglist_data *pgdat = zone->zone_pgdat;
4095 4096 4097 4098
	int ret;
	ret = zone_wait_table_init(zone, size);
	if (ret)
		return ret;
4099 4100 4101 4102
	pgdat->nr_zones = zone_idx(zone) + 1;

	zone->zone_start_pfn = zone_start_pfn;

4103 4104 4105 4106 4107 4108
	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));

4109
	zone_init_free_lists(zone);
4110 4111

	return 0;
4112 4113
}

T
Tejun Heo 已提交
4114
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4115 4116 4117 4118 4119 4120 4121
#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
 */
4122
int __meminit __early_pfn_to_nid(unsigned long pfn)
4123
{
4124 4125
	unsigned long start_pfn, end_pfn;
	int i, nid;
4126

4127
	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
4128
		if (start_pfn <= pfn && pfn < end_pfn)
4129
			return nid;
4130 4131
	/* This is a memory hole */
	return -1;
4132 4133 4134
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */

4135 4136
int __meminit early_pfn_to_nid(unsigned long pfn)
{
4137 4138 4139 4140 4141 4142 4143
	int nid;

	nid = __early_pfn_to_nid(pfn);
	if (nid >= 0)
		return nid;
	/* just returns 0 */
	return 0;
4144 4145
}

4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156
#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
4157

4158 4159
/**
 * free_bootmem_with_active_regions - Call free_bootmem_node for each active range
4160 4161
 * @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
4162 4163 4164 4165 4166
 *
 * 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.
 */
4167
void __init free_bootmem_with_active_regions(int nid, unsigned long max_low_pfn)
4168
{
4169 4170
	unsigned long start_pfn, end_pfn;
	int i, this_nid;
4171

4172 4173 4174
	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);
4175

4176 4177 4178 4179
		if (start_pfn < end_pfn)
			free_bootmem_node(NODE_DATA(this_nid),
					  PFN_PHYS(start_pfn),
					  (end_pfn - start_pfn) << PAGE_SHIFT);
4180 4181 4182
	}
}

4183 4184
/**
 * sparse_memory_present_with_active_regions - Call memory_present for each active range
4185
 * @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
4186 4187 4188
 *
 * If an architecture guarantees that all ranges registered with
 * add_active_ranges() contain no holes and may be freed, this
4189
 * function may be used instead of calling memory_present() manually.
4190 4191 4192
 */
void __init sparse_memory_present_with_active_regions(int nid)
{
4193 4194
	unsigned long start_pfn, end_pfn;
	int i, this_nid;
4195

4196 4197
	for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid)
		memory_present(this_nid, start_pfn, end_pfn);
4198 4199 4200 4201
}

/**
 * get_pfn_range_for_nid - Return the start and end page frames for a node
4202 4203 4204
 * @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.
4205 4206 4207 4208
 *
 * 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
4209
 * PFNs will be 0.
4210
 */
4211
void __meminit get_pfn_range_for_nid(unsigned int nid,
4212 4213
			unsigned long *start_pfn, unsigned long *end_pfn)
{
4214
	unsigned long this_start_pfn, this_end_pfn;
4215
	int i;
4216

4217 4218 4219
	*start_pfn = -1UL;
	*end_pfn = 0;

4220 4221 4222
	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);
4223 4224
	}

4225
	if (*start_pfn == -1UL)
4226 4227 4228
		*start_pfn = 0;
}

M
Mel Gorman 已提交
4229 4230 4231 4232 4233
/*
 * 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
4234
static void __init find_usable_zone_for_movable(void)
M
Mel Gorman 已提交
4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251
{
	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
4252
 * because it is sized independent of architecture. Unlike the other zones,
M
Mel Gorman 已提交
4253 4254 4255 4256 4257 4258 4259
 * 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
4260
static void __meminit adjust_zone_range_for_zone_movable(int nid,
M
Mel Gorman 已提交
4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285
					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;
	}
}

4286 4287 4288 4289
/*
 * 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
4290
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
4291 4292 4293 4294 4295 4296 4297 4298 4299 4300
					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
4301 4302 4303
	adjust_zone_range_for_zone_movable(nid, zone_type,
				node_start_pfn, node_end_pfn,
				&zone_start_pfn, &zone_end_pfn);
4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318

	/* 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,
4319
 * then all holes in the requested range will be accounted for.
4320
 */
4321
unsigned long __meminit __absent_pages_in_range(int nid,
4322 4323 4324
				unsigned long range_start_pfn,
				unsigned long range_end_pfn)
{
4325 4326 4327
	unsigned long nr_absent = range_end_pfn - range_start_pfn;
	unsigned long start_pfn, end_pfn;
	int i;
4328

4329 4330 4331 4332
	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;
4333
	}
4334
	return nr_absent;
4335 4336 4337 4338 4339 4340 4341
}

/**
 * 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
 *
4342
 * It returns the number of pages frames in memory holes within a range.
4343 4344 4345 4346 4347 4348 4349 4350
 */
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
4351
static unsigned long __meminit zone_absent_pages_in_node(int nid,
4352 4353 4354
					unsigned long zone_type,
					unsigned long *ignored)
{
4355 4356
	unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type];
	unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
4357 4358 4359 4360
	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);
4361 4362
	zone_start_pfn = clamp(node_start_pfn, zone_low, zone_high);
	zone_end_pfn = clamp(node_end_pfn, zone_low, zone_high);
4363

M
Mel Gorman 已提交
4364 4365 4366
	adjust_zone_range_for_zone_movable(nid, zone_type,
			node_start_pfn, node_end_pfn,
			&zone_start_pfn, &zone_end_pfn);
4367
	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
4368
}
4369

T
Tejun Heo 已提交
4370
#else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
P
Paul Mundt 已提交
4371
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
4372 4373 4374 4375 4376 4377
					unsigned long zone_type,
					unsigned long *zones_size)
{
	return zones_size[zone_type];
}

P
Paul Mundt 已提交
4378
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
4379 4380 4381 4382 4383 4384 4385 4386
						unsigned long zone_type,
						unsigned long *zholes_size)
{
	if (!zholes_size)
		return 0;

	return zholes_size[zone_type];
}
4387

T
Tejun Heo 已提交
4388
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4389

4390
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 4410
		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);
}

4411 4412 4413
#ifndef CONFIG_SPARSEMEM
/*
 * Calculate the size of the zone->blockflags rounded to an unsigned long
4414 4415
 * 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
4416 4417 4418 4419 4420 4421 4422
 * 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;

4423 4424
	usemapsize = roundup(zonesize, pageblock_nr_pages);
	usemapsize = usemapsize >> pageblock_order;
4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435
	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;
4436
	if (usemapsize)
4437 4438
		zone->pageblock_flags = alloc_bootmem_node_nopanic(pgdat,
								   usemapsize);
4439 4440
}
#else
4441
static inline void setup_usemap(struct pglist_data *pgdat,
4442 4443 4444
				struct zone *zone, unsigned long zonesize) {}
#endif /* CONFIG_SPARSEMEM */

4445
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
4446

4447
/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
4448
void __init set_pageblock_order(void)
4449
{
4450 4451
	unsigned int order;

4452 4453 4454 4455
	/* Check that pageblock_nr_pages has not already been setup */
	if (pageblock_order)
		return;

4456 4457 4458 4459 4460
	if (HPAGE_SHIFT > PAGE_SHIFT)
		order = HUGETLB_PAGE_ORDER;
	else
		order = MAX_ORDER - 1;

4461 4462
	/*
	 * Assume the largest contiguous order of interest is a huge page.
4463 4464
	 * This value may be variable depending on boot parameters on IA64 and
	 * powerpc.
4465 4466 4467 4468 4469
	 */
	pageblock_order = order;
}
#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

4470 4471
/*
 * When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
4472 4473 4474
 * 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
4475
 */
4476
void __init set_pageblock_order(void)
4477 4478
{
}
4479 4480 4481

#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */

4482 4483 4484 4485 4486 4487 4488 4489 4490 4491 4492 4493 4494 4495 4496 4497 4498 4499 4500 4501
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
4502 4503 4504 4505 4506
/*
 * Set up the zone data structures:
 *   - mark all pages reserved
 *   - mark all memory queues empty
 *   - clear the memory bitmaps
4507 4508
 *
 * NOTE: pgdat should get zeroed by caller.
L
Linus Torvalds 已提交
4509
 */
4510
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
L
Linus Torvalds 已提交
4511 4512
		unsigned long *zones_size, unsigned long *zholes_size)
{
4513
	enum zone_type j;
4514
	int nid = pgdat->node_id;
L
Linus Torvalds 已提交
4515
	unsigned long zone_start_pfn = pgdat->node_start_pfn;
4516
	int ret;
L
Linus Torvalds 已提交
4517

4518
	pgdat_resize_init(pgdat);
4519 4520 4521 4522 4523
#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
4524
	init_waitqueue_head(&pgdat->kswapd_wait);
4525
	init_waitqueue_head(&pgdat->pfmemalloc_wait);
4526
	pgdat_page_cgroup_init(pgdat);
4527

L
Linus Torvalds 已提交
4528 4529
	for (j = 0; j < MAX_NR_ZONES; j++) {
		struct zone *zone = pgdat->node_zones + j;
4530
		unsigned long size, realsize, freesize, memmap_pages;
L
Linus Torvalds 已提交
4531

4532
		size = zone_spanned_pages_in_node(nid, j, zones_size);
4533
		realsize = freesize = size - zone_absent_pages_in_node(nid, j,
4534
								zholes_size);
L
Linus Torvalds 已提交
4535

4536
		/*
4537
		 * Adjust freesize so that it accounts for how much memory
4538 4539 4540
		 * is used by this zone for memmap. This affects the watermark
		 * and per-cpu initialisations
		 */
4541
		memmap_pages = calc_memmap_size(size, realsize);
4542 4543
		if (freesize >= memmap_pages) {
			freesize -= memmap_pages;
4544 4545 4546 4547
			if (memmap_pages)
				printk(KERN_DEBUG
				       "  %s zone: %lu pages used for memmap\n",
				       zone_names[j], memmap_pages);
4548 4549
		} else
			printk(KERN_WARNING
4550 4551
				"  %s zone: %lu pages exceeds freesize %lu\n",
				zone_names[j], memmap_pages, freesize);
4552

4553
		/* Account for reserved pages */
4554 4555
		if (j == 0 && freesize > dma_reserve) {
			freesize -= dma_reserve;
Y
Yinghai Lu 已提交
4556
			printk(KERN_DEBUG "  %s zone: %lu pages reserved\n",
4557
					zone_names[0], dma_reserve);
4558 4559
		}

4560
		if (!is_highmem_idx(j))
4561
			nr_kernel_pages += freesize;
4562 4563 4564
		/* Charge for highmem memmap if there are enough kernel pages */
		else if (nr_kernel_pages > memmap_pages * 2)
			nr_kernel_pages -= memmap_pages;
4565
		nr_all_pages += freesize;
L
Linus Torvalds 已提交
4566 4567

		zone->spanned_pages = size;
4568 4569 4570 4571 4572 4573 4574
		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;
4575
#ifdef CONFIG_NUMA
4576
		zone->node = nid;
4577
		zone->min_unmapped_pages = (freesize*sysctl_min_unmapped_ratio)
4578
						/ 100;
4579
		zone->min_slab_pages = (freesize * sysctl_min_slab_ratio) / 100;
4580
#endif
L
Linus Torvalds 已提交
4581 4582 4583
		zone->name = zone_names[j];
		spin_lock_init(&zone->lock);
		spin_lock_init(&zone->lru_lock);
4584
		zone_seqlock_init(zone);
L
Linus Torvalds 已提交
4585 4586
		zone->zone_pgdat = pgdat;

4587
		zone_pcp_init(zone);
4588
		lruvec_init(&zone->lruvec);
L
Linus Torvalds 已提交
4589 4590 4591
		if (!size)
			continue;

4592
		set_pageblock_order();
4593
		setup_usemap(pgdat, zone, size);
D
Dave Hansen 已提交
4594 4595
		ret = init_currently_empty_zone(zone, zone_start_pfn,
						size, MEMMAP_EARLY);
4596
		BUG_ON(ret);
4597
		memmap_init(size, nid, j, zone_start_pfn);
L
Linus Torvalds 已提交
4598 4599 4600 4601
		zone_start_pfn += size;
	}
}

S
Sam Ravnborg 已提交
4602
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
L
Linus Torvalds 已提交
4603 4604 4605 4606 4607
{
	/* Skip empty nodes */
	if (!pgdat->node_spanned_pages)
		return;

A
Andy Whitcroft 已提交
4608
#ifdef CONFIG_FLAT_NODE_MEM_MAP
L
Linus Torvalds 已提交
4609 4610
	/* ia64 gets its own node_mem_map, before this, without bootmem */
	if (!pgdat->node_mem_map) {
4611
		unsigned long size, start, end;
A
Andy Whitcroft 已提交
4612 4613
		struct page *map;

4614 4615 4616 4617 4618 4619 4620 4621 4622
		/*
		 * 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);
4623 4624
		map = alloc_remap(pgdat->node_id, size);
		if (!map)
4625
			map = alloc_bootmem_node_nopanic(pgdat, size);
4626
		pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
L
Linus Torvalds 已提交
4627
	}
4628
#ifndef CONFIG_NEED_MULTIPLE_NODES
L
Linus Torvalds 已提交
4629 4630 4631
	/*
	 * With no DISCONTIG, the global mem_map is just set as node 0's
	 */
4632
	if (pgdat == NODE_DATA(0)) {
L
Linus Torvalds 已提交
4633
		mem_map = NODE_DATA(0)->node_mem_map;
T
Tejun Heo 已提交
4634
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
4635
		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
4636
			mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
T
Tejun Heo 已提交
4637
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
4638
	}
L
Linus Torvalds 已提交
4639
#endif
A
Andy Whitcroft 已提交
4640
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
L
Linus Torvalds 已提交
4641 4642
}

4643 4644
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
4645
{
4646 4647
	pg_data_t *pgdat = NODE_DATA(nid);

4648
	/* pg_data_t should be reset to zero when it's allocated */
4649
	WARN_ON(pgdat->nr_zones || pgdat->classzone_idx);
4650

L
Linus Torvalds 已提交
4651 4652
	pgdat->node_id = nid;
	pgdat->node_start_pfn = node_start_pfn;
4653
	init_zone_allows_reclaim(nid);
4654
	calculate_node_totalpages(pgdat, zones_size, zholes_size);
L
Linus Torvalds 已提交
4655 4656

	alloc_node_mem_map(pgdat);
4657 4658 4659 4660 4661
#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
4662 4663 4664 4665

	free_area_init_core(pgdat, zones_size, zholes_size);
}

T
Tejun Heo 已提交
4666
#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
M
Miklos Szeredi 已提交
4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686

#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

4687 4688 4689 4690 4691 4692 4693 4694 4695 4696 4697 4698 4699 4700 4701 4702 4703 4704 4705 4706 4707 4708
/**
 * 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;
4709
	unsigned long start, end, mask;
4710
	int last_nid = -1;
4711
	int i, nid;
4712

4713
	for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
4714 4715 4716 4717 4718 4719 4720 4721 4722 4723 4724 4725 4726 4727 4728 4729 4730 4731 4732 4733 4734 4735 4736
		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;
}

4737
/* Find the lowest pfn for a node */
A
Adrian Bunk 已提交
4738
static unsigned long __init find_min_pfn_for_node(int nid)
4739
{
4740
	unsigned long min_pfn = ULONG_MAX;
4741 4742
	unsigned long start_pfn;
	int i;
4743

4744 4745
	for_each_mem_pfn_range(i, nid, &start_pfn, NULL, NULL)
		min_pfn = min(min_pfn, start_pfn);
4746

4747 4748
	if (min_pfn == ULONG_MAX) {
		printk(KERN_WARNING
4749
			"Could not find start_pfn for node %d\n", nid);
4750 4751 4752 4753
		return 0;
	}

	return min_pfn;
4754 4755 4756 4757 4758 4759
}

/**
 * find_min_pfn_with_active_regions - Find the minimum PFN registered
 *
 * It returns the minimum PFN based on information provided via
4760
 * add_active_range().
4761 4762 4763 4764 4765 4766
 */
unsigned long __init find_min_pfn_with_active_regions(void)
{
	return find_min_pfn_for_node(MAX_NUMNODES);
}

4767 4768 4769
/*
 * early_calculate_totalpages()
 * Sum pages in active regions for movable zone.
4770
 * Populate N_MEMORY for calculating usable_nodes.
4771
 */
A
Adrian Bunk 已提交
4772
static unsigned long __init early_calculate_totalpages(void)
4773 4774
{
	unsigned long totalpages = 0;
4775 4776 4777 4778 4779
	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;
4780

4781 4782
		totalpages += pages;
		if (pages)
4783
			node_set_state(nid, N_MEMORY);
4784 4785
	}
  	return totalpages;
4786 4787
}

M
Mel Gorman 已提交
4788 4789 4790 4791 4792 4793
/*
 * 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
 */
4794
static void __init find_zone_movable_pfns_for_nodes(void)
M
Mel Gorman 已提交
4795 4796 4797 4798
{
	int i, nid;
	unsigned long usable_startpfn;
	unsigned long kernelcore_node, kernelcore_remaining;
4799
	/* save the state before borrow the nodemask */
4800
	nodemask_t saved_node_state = node_states[N_MEMORY];
4801
	unsigned long totalpages = early_calculate_totalpages();
4802
	int usable_nodes = nodes_weight(node_states[N_MEMORY]);
M
Mel Gorman 已提交
4803

4804 4805 4806 4807 4808 4809 4810 4811 4812 4813 4814 4815 4816 4817 4818 4819 4820 4821 4822 4823 4824 4825
	/*
	 * 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
4826 4827
	/* If kernelcore was not specified, there is no ZONE_MOVABLE */
	if (!required_kernelcore)
4828
		goto out;
M
Mel Gorman 已提交
4829 4830 4831 4832 4833 4834 4835 4836

	/* 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;
4837
	for_each_node_state(nid, N_MEMORY) {
4838 4839
		unsigned long start_pfn, end_pfn;

M
Mel Gorman 已提交
4840 4841 4842 4843 4844 4845 4846 4847 4848 4849 4850 4851 4852 4853 4854 4855
		/*
		 * 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 */
4856
		for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
M
Mel Gorman 已提交
4857 4858
			unsigned long size_pages;

4859
			start_pfn = max(start_pfn, zone_movable_pfn[nid]);
M
Mel Gorman 已提交
4860 4861 4862 4863 4864 4865 4866 4867 4868 4869 4870 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
			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);
4926 4927 4928

out:
	/* restore the node_state */
4929
	node_states[N_MEMORY] = saved_node_state;
M
Mel Gorman 已提交
4930 4931
}

4932 4933
/* Any regular or high memory on that node ? */
static void check_for_memory(pg_data_t *pgdat, int nid)
4934 4935 4936
{
	enum zone_type zone_type;

4937 4938 4939 4940
	if (N_MEMORY == N_NORMAL_MEMORY)
		return;

	for (zone_type = 0; zone_type <= ZONE_MOVABLE - 1; zone_type++) {
4941
		struct zone *zone = &pgdat->node_zones[zone_type];
4942
		if (zone->present_pages) {
4943 4944 4945 4946
			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);
4947 4948
			break;
		}
4949 4950 4951
	}
}

4952 4953
/**
 * free_area_init_nodes - Initialise all pg_data_t and zone data
4954
 * @max_zone_pfn: an array of max PFNs for each zone
4955 4956 4957 4958 4959 4960 4961 4962 4963 4964 4965 4966
 *
 * 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)
{
4967 4968
	unsigned long start_pfn, end_pfn;
	int i, nid;
4969

4970 4971 4972 4973 4974 4975 4976 4977
	/* 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
4978 4979
		if (i == ZONE_MOVABLE)
			continue;
4980 4981 4982 4983 4984
		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
4985 4986 4987 4988 4989
	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));
4990
	find_zone_movable_pfns_for_nodes();
4991 4992

	/* Print out the zone ranges */
4993
	printk("Zone ranges:\n");
M
Mel Gorman 已提交
4994 4995 4996
	for (i = 0; i < MAX_NR_ZONES; i++) {
		if (i == ZONE_MOVABLE)
			continue;
4997
		printk(KERN_CONT "  %-8s ", zone_names[i]);
4998 4999
		if (arch_zone_lowest_possible_pfn[i] ==
				arch_zone_highest_possible_pfn[i])
5000
			printk(KERN_CONT "empty\n");
5001
		else
5002 5003 5004 5005
			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
5006 5007 5008
	}

	/* Print out the PFNs ZONE_MOVABLE begins at in each node */
5009
	printk("Movable zone start for each node\n");
M
Mel Gorman 已提交
5010 5011
	for (i = 0; i < MAX_NUMNODES; i++) {
		if (zone_movable_pfn[i])
5012 5013
			printk("  Node %d: %#010lx\n", i,
			       zone_movable_pfn[i] << PAGE_SHIFT);
M
Mel Gorman 已提交
5014
	}
5015

5016
	/* Print out the early node map */
5017
	printk("Early memory node ranges\n");
5018
	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid)
5019 5020
		printk("  node %3d: [mem %#010lx-%#010lx]\n", nid,
		       start_pfn << PAGE_SHIFT, (end_pfn << PAGE_SHIFT) - 1);
5021 5022

	/* Initialise every node */
5023
	mminit_verify_pageflags_layout();
5024
	setup_nr_node_ids();
5025 5026
	for_each_online_node(nid) {
		pg_data_t *pgdat = NODE_DATA(nid);
5027
		free_area_init_node(nid, NULL,
5028
				find_min_pfn_for_node(nid), NULL);
5029 5030 5031

		/* Any memory on that node */
		if (pgdat->node_present_pages)
5032 5033
			node_set_state(nid, N_MEMORY);
		check_for_memory(pgdat, nid);
5034 5035
	}
}
M
Mel Gorman 已提交
5036

5037
static int __init cmdline_parse_core(char *p, unsigned long *core)
M
Mel Gorman 已提交
5038 5039 5040 5041 5042 5043
{
	unsigned long long coremem;
	if (!p)
		return -EINVAL;

	coremem = memparse(p, &p);
5044
	*core = coremem >> PAGE_SHIFT;
M
Mel Gorman 已提交
5045

5046
	/* Paranoid check that UL is enough for the coremem value */
M
Mel Gorman 已提交
5047 5048 5049 5050
	WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);

	return 0;
}
M
Mel Gorman 已提交
5051

5052 5053 5054 5055 5056 5057 5058 5059 5060 5061 5062 5063 5064 5065 5066 5067 5068 5069
/*
 * 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
5070
early_param("kernelcore", cmdline_parse_kernelcore);
5071
early_param("movablecore", cmdline_parse_movablecore);
M
Mel Gorman 已提交
5072

T
Tejun Heo 已提交
5073
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
5074

5075
/**
5076 5077
 * set_dma_reserve - set the specified number of pages reserved in the first zone
 * @new_dma_reserve: The number of pages to mark reserved
5078 5079 5080 5081
 *
 * 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
5082 5083 5084
 * 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.
5085 5086 5087 5088 5089 5090
 */
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
	dma_reserve = new_dma_reserve;
}

L
Linus Torvalds 已提交
5091 5092
void __init free_area_init(unsigned long *zones_size)
{
5093
	free_area_init_node(0, zones_size,
L
Linus Torvalds 已提交
5094 5095 5096 5097 5098 5099 5100 5101
			__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;

5102
	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
5103
		lru_add_drain_cpu(cpu);
5104 5105 5106 5107 5108 5109 5110 5111
		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.
		 */
5112
		vm_events_fold_cpu(cpu);
5113 5114 5115 5116 5117 5118 5119 5120

		/*
		 * 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.
		 */
5121
		refresh_cpu_vm_stats(cpu);
L
Linus Torvalds 已提交
5122 5123 5124 5125 5126 5127 5128 5129 5130
	}
	return NOTIFY_OK;
}

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

5131 5132 5133 5134 5135 5136 5137 5138
/*
 * 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;
5139
	enum zone_type i, j;
5140 5141 5142 5143 5144 5145 5146 5147 5148 5149 5150 5151

	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];
			}

5152 5153
			/* we treat the high watermark as reserved pages. */
			max += high_wmark_pages(zone);
5154 5155 5156 5157

			if (max > zone->present_pages)
				max = zone->present_pages;
			reserve_pages += max;
5158 5159 5160 5161 5162 5163 5164 5165 5166 5167
			/*
			 * 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;
5168 5169
		}
	}
5170
	dirty_balance_reserve = reserve_pages;
5171 5172 5173
	totalreserve_pages = reserve_pages;
}

L
Linus Torvalds 已提交
5174 5175 5176 5177 5178 5179 5180 5181 5182
/*
 * 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;
5183
	enum zone_type j, idx;
L
Linus Torvalds 已提交
5184

5185
	for_each_online_pgdat(pgdat) {
L
Linus Torvalds 已提交
5186 5187 5188 5189 5190 5191
		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;

5192 5193
			idx = j;
			while (idx) {
L
Linus Torvalds 已提交
5194 5195
				struct zone *lower_zone;

5196 5197
				idx--;

L
Linus Torvalds 已提交
5198 5199 5200 5201 5202 5203 5204 5205 5206 5207
				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;
			}
		}
	}
5208 5209 5210

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
5211 5212
}

5213
static void __setup_per_zone_wmarks(void)
L
Linus Torvalds 已提交
5214 5215 5216 5217 5218 5219 5220 5221 5222 5223 5224 5225 5226
{
	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) {
5227 5228
		u64 tmp;

5229
		spin_lock_irqsave(&zone->lock, flags);
5230 5231
		tmp = (u64)pages_min * zone->present_pages;
		do_div(tmp, lowmem_pages);
L
Linus Torvalds 已提交
5232 5233
		if (is_highmem(zone)) {
			/*
N
Nick Piggin 已提交
5234 5235 5236 5237
			 * __GFP_HIGH and PF_MEMALLOC allocations usually don't
			 * need highmem pages, so cap pages_min to a small
			 * value here.
			 *
5238
			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
N
Nick Piggin 已提交
5239 5240
			 * deltas controls asynch page reclaim, and so should
			 * not be capped for highmem.
L
Linus Torvalds 已提交
5241 5242 5243 5244 5245 5246 5247 5248
			 */
			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;
5249
			zone->watermark[WMARK_MIN] = min_pages;
L
Linus Torvalds 已提交
5250
		} else {
N
Nick Piggin 已提交
5251 5252
			/*
			 * If it's a lowmem zone, reserve a number of pages
L
Linus Torvalds 已提交
5253 5254
			 * proportionate to the zone's size.
			 */
5255
			zone->watermark[WMARK_MIN] = tmp;
L
Linus Torvalds 已提交
5256 5257
		}

5258 5259
		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) + (tmp >> 2);
		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
5260

5261
		setup_zone_migrate_reserve(zone);
5262
		spin_unlock_irqrestore(&zone->lock, flags);
L
Linus Torvalds 已提交
5263
	}
5264 5265 5266

	/* update totalreserve_pages */
	calculate_totalreserve_pages();
L
Linus Torvalds 已提交
5267 5268
}

5269 5270 5271 5272 5273 5274 5275 5276 5277 5278 5279 5280 5281 5282
/**
 * 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);
}

5283
/*
5284 5285 5286 5287 5288 5289 5290 5291 5292 5293 5294 5295 5296 5297 5298 5299 5300 5301 5302 5303
 * 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
 */
5304
static void __meminit calculate_zone_inactive_ratio(struct zone *zone)
5305
{
5306
	unsigned int gb, ratio;
5307

5308 5309 5310
	/* Zone size in gigabytes */
	gb = zone->present_pages >> (30 - PAGE_SHIFT);
	if (gb)
5311
		ratio = int_sqrt(10 * gb);
5312 5313
	else
		ratio = 1;
5314

5315 5316
	zone->inactive_ratio = ratio;
}
5317

5318
static void __meminit setup_per_zone_inactive_ratio(void)
5319 5320 5321 5322 5323
{
	struct zone *zone;

	for_each_zone(zone)
		calculate_zone_inactive_ratio(zone);
5324 5325
}

L
Linus Torvalds 已提交
5326 5327 5328 5329 5330 5331 5332 5333 5334 5335 5336 5337 5338 5339 5340 5341 5342 5343 5344 5345 5346 5347 5348 5349
/*
 * 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
 */
5350
int __meminit init_per_zone_wmark_min(void)
L
Linus Torvalds 已提交
5351 5352 5353 5354 5355 5356 5357 5358 5359 5360
{
	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;
5361
	setup_per_zone_wmarks();
5362
	refresh_zone_stat_thresholds();
L
Linus Torvalds 已提交
5363
	setup_per_zone_lowmem_reserve();
5364
	setup_per_zone_inactive_ratio();
L
Linus Torvalds 已提交
5365 5366
	return 0;
}
5367
module_init(init_per_zone_wmark_min)
L
Linus Torvalds 已提交
5368 5369 5370 5371 5372 5373 5374

/*
 * 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, 
5375
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
5376
{
5377
	proc_dointvec(table, write, buffer, length, ppos);
5378
	if (write)
5379
		setup_per_zone_wmarks();
L
Linus Torvalds 已提交
5380 5381 5382
	return 0;
}

5383 5384
#ifdef CONFIG_NUMA
int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
5385
	void __user *buffer, size_t *length, loff_t *ppos)
5386 5387 5388 5389
{
	struct zone *zone;
	int rc;

5390
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5391 5392 5393 5394
	if (rc)
		return rc;

	for_each_zone(zone)
5395
		zone->min_unmapped_pages = (zone->present_pages *
5396 5397 5398
				sysctl_min_unmapped_ratio) / 100;
	return 0;
}
5399 5400

int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
5401
	void __user *buffer, size_t *length, loff_t *ppos)
5402 5403 5404 5405
{
	struct zone *zone;
	int rc;

5406
	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
5407 5408 5409 5410 5411 5412 5413 5414
	if (rc)
		return rc;

	for_each_zone(zone)
		zone->min_slab_pages = (zone->present_pages *
				sysctl_min_slab_ratio) / 100;
	return 0;
}
5415 5416
#endif

L
Linus Torvalds 已提交
5417 5418 5419 5420 5421 5422
/*
 * 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
5423
 * minimum watermarks. The lowmem reserve ratio can only make sense
L
Linus Torvalds 已提交
5424 5425 5426
 * if in function of the boot time zone sizes.
 */
int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
5427
	void __user *buffer, size_t *length, loff_t *ppos)
L
Linus Torvalds 已提交
5428
{
5429
	proc_dointvec_minmax(table, write, buffer, length, ppos);
L
Linus Torvalds 已提交
5430 5431 5432 5433
	setup_per_zone_lowmem_reserve();
	return 0;
}

5434 5435 5436 5437 5438 5439 5440
/*
 * 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,
5441
	void __user *buffer, size_t *length, loff_t *ppos)
5442 5443 5444 5445 5446
{
	struct zone *zone;
	unsigned int cpu;
	int ret;

5447
	ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
5448
	if (!write || (ret < 0))
5449
		return ret;
5450
	for_each_populated_zone(zone) {
5451
		for_each_possible_cpu(cpu) {
5452 5453
			unsigned long  high;
			high = zone->present_pages / percpu_pagelist_fraction;
5454 5455
			setup_pagelist_highmark(
				per_cpu_ptr(zone->pageset, cpu), high);
5456 5457 5458 5459 5460
		}
	}
	return 0;
}

5461
int hashdist = HASHDIST_DEFAULT;
L
Linus Torvalds 已提交
5462 5463 5464 5465 5466 5467 5468 5469 5470 5471 5472 5473 5474 5475 5476 5477 5478 5479 5480 5481 5482 5483 5484 5485 5486

#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,
5487 5488
				     unsigned long low_limit,
				     unsigned long high_limit)
L
Linus Torvalds 已提交
5489
{
5490
	unsigned long long max = high_limit;
L
Linus Torvalds 已提交
5491 5492 5493 5494 5495 5496
	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
5497
		numentries = nr_kernel_pages;
L
Linus Torvalds 已提交
5498 5499 5500 5501 5502 5503 5504 5505 5506
		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);
5507 5508

		/* Make sure we've got at least a 0-order allocation.. */
5509 5510 5511 5512 5513 5514 5515 5516
		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))
5517
			numentries = PAGE_SIZE / bucketsize;
L
Linus Torvalds 已提交
5518
	}
5519
	numentries = roundup_pow_of_two(numentries);
L
Linus Torvalds 已提交
5520 5521 5522 5523 5524 5525

	/* 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);
	}
5526
	max = min(max, 0x80000000ULL);
L
Linus Torvalds 已提交
5527

5528 5529
	if (numentries < low_limit)
		numentries = low_limit;
L
Linus Torvalds 已提交
5530 5531 5532
	if (numentries > max)
		numentries = max;

5533
	log2qty = ilog2(numentries);
L
Linus Torvalds 已提交
5534 5535 5536 5537

	do {
		size = bucketsize << log2qty;
		if (flags & HASH_EARLY)
5538
			table = alloc_bootmem_nopanic(size);
L
Linus Torvalds 已提交
5539 5540 5541
		else if (hashdist)
			table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
		else {
5542 5543
			/*
			 * If bucketsize is not a power-of-two, we may free
5544 5545
			 * some pages at the end of hash table which
			 * alloc_pages_exact() automatically does
5546
			 */
5547
			if (get_order(size) < MAX_ORDER) {
5548
				table = alloc_pages_exact(size, GFP_ATOMIC);
5549 5550
				kmemleak_alloc(table, size, 1, GFP_ATOMIC);
			}
L
Linus Torvalds 已提交
5551 5552 5553 5554 5555 5556
		}
	} while (!table && size > PAGE_SIZE && --log2qty);

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

5557
	printk(KERN_INFO "%s hash table entries: %ld (order: %d, %lu bytes)\n",
L
Linus Torvalds 已提交
5558
	       tablename,
5559
	       (1UL << log2qty),
5560
	       ilog2(size) - PAGE_SHIFT,
L
Linus Torvalds 已提交
5561 5562 5563 5564 5565 5566 5567 5568 5569
	       size);

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

	return table;
}
5570

5571 5572 5573 5574 5575 5576 5577 5578 5579 5580 5581 5582 5583 5584 5585
/* 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);
5586
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5587
#else
5588
	pfn = pfn - round_down(zone->zone_start_pfn, pageblock_nr_pages);
5589
	return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
5590 5591 5592 5593
#endif /* CONFIG_SPARSEMEM */
}

/**
5594
 * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
5595 5596 5597 5598 5599 5600 5601 5602 5603 5604 5605 5606 5607 5608 5609 5610 5611 5612 5613 5614 5615 5616
 * @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;
5617

5618 5619 5620 5621
	return flags;
}

/**
5622
 * set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
5623 5624 5625 5626 5627 5628 5629 5630 5631 5632 5633 5634 5635 5636 5637 5638 5639
 * @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);
5640 5641
	VM_BUG_ON(pfn < zone->zone_start_pfn);
	VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
5642 5643 5644 5645 5646 5647 5648

	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
5649 5650

/*
5651 5652 5653 5654 5655 5656
 * 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
5657
 */
5658 5659
bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
			 bool skip_hwpoisoned_pages)
5660 5661
{
	unsigned long pfn, iter, found;
5662 5663
	int mt;

5664 5665
	/*
	 * For avoiding noise data, lru_add_drain_all() should be called
5666
	 * If ZONE_MOVABLE, the zone never contains unmovable pages
5667 5668
	 */
	if (zone_idx(zone) == ZONE_MOVABLE)
5669
		return false;
5670 5671
	mt = get_pageblock_migratetype(page);
	if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
5672
		return false;
5673 5674 5675 5676 5677

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

5678
		if (!pfn_valid_within(check))
5679
			continue;
5680

5681
		page = pfn_to_page(check);
5682 5683 5684 5685 5686 5687 5688
		/*
		 * 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)) {
5689 5690 5691 5692
			if (PageBuddy(page))
				iter += (1 << page_order(page)) - 1;
			continue;
		}
5693

5694 5695 5696 5697 5698 5699 5700
		/*
		 * The HWPoisoned page may be not in buddy system, and
		 * page_count() is not 0.
		 */
		if (skip_hwpoisoned_pages && PageHWPoison(page))
			continue;

5701 5702 5703 5704 5705 5706 5707 5708 5709 5710 5711 5712 5713 5714 5715 5716
		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)
5717
			return true;
5718
	}
5719
	return false;
5720 5721 5722 5723
}

bool is_pageblock_removable_nolock(struct page *page)
{
5724 5725
	struct zone *zone;
	unsigned long pfn;
5726 5727 5728 5729 5730

	/*
	 * 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.
5731 5732
	 * We have to take care about the node as well. If the node is offline
	 * its NODE_DATA will be NULL - see page_zone.
5733
	 */
5734 5735 5736 5737 5738 5739
	if (!node_online(page_to_nid(page)))
		return false;

	zone = page_zone(page);
	pfn = page_to_pfn(page);
	if (zone->zone_start_pfn > pfn ||
5740 5741 5742
			zone->zone_start_pfn + zone->spanned_pages <= pfn)
		return false;

5743
	return !has_unmovable_pages(zone, page, 0, true);
K
KAMEZAWA Hiroyuki 已提交
5744
}
K
KAMEZAWA Hiroyuki 已提交
5745

5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 5756 5757 5758 5759 5760
#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. */
5761 5762
static int __alloc_contig_migrate_range(struct compact_control *cc,
					unsigned long start, unsigned long end)
5763 5764
{
	/* This function is based on compact_zone() from compaction.c. */
5765
	unsigned long nr_reclaimed;
5766 5767 5768 5769
	unsigned long pfn = start;
	unsigned int tries = 0;
	int ret = 0;

5770
	migrate_prep();
5771

5772
	while (pfn < end || !list_empty(&cc->migratepages)) {
5773 5774 5775 5776 5777
		if (fatal_signal_pending(current)) {
			ret = -EINTR;
			break;
		}

5778 5779 5780
		if (list_empty(&cc->migratepages)) {
			cc->nr_migratepages = 0;
			pfn = isolate_migratepages_range(cc->zone, cc,
M
Minchan Kim 已提交
5781
							 pfn, end, true);
5782 5783 5784 5785 5786 5787 5788 5789 5790 5791
			if (!pfn) {
				ret = -EINTR;
				break;
			}
			tries = 0;
		} else if (++tries == 5) {
			ret = ret < 0 ? ret : -EBUSY;
			break;
		}

5792 5793 5794
		nr_reclaimed = reclaim_clean_pages_from_list(cc->zone,
							&cc->migratepages);
		cc->nr_migratepages -= nr_reclaimed;
5795

5796
		ret = migrate_pages(&cc->migratepages,
5797
				    alloc_migrate_target,
5798 5799
				    0, false, MIGRATE_SYNC,
				    MR_CMA);
5800 5801
	}

5802
	putback_movable_pages(&cc->migratepages);
5803 5804 5805 5806 5807 5808 5809
	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
5810 5811 5812 5813
 * @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.
5814 5815 5816 5817 5818 5819 5820 5821 5822 5823 5824 5825
 *
 * 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().
 */
5826 5827
int alloc_contig_range(unsigned long start, unsigned long end,
		       unsigned migratetype)
5828 5829 5830 5831
{
	unsigned long outer_start, outer_end;
	int ret = 0, order;

5832 5833 5834 5835 5836 5837 5838 5839 5840
	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);

5841 5842 5843 5844 5845 5846 5847 5848 5849 5850 5851 5852 5853 5854 5855 5856 5857 5858 5859 5860 5861 5862 5863 5864 5865
	/*
	 * 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),
5866 5867
				       pfn_max_align_up(end), migratetype,
				       false);
5868
	if (ret)
5869
		return ret;
5870

5871
	ret = __alloc_contig_migrate_range(&cc, start, end);
5872 5873 5874 5875 5876 5877 5878 5879 5880 5881 5882 5883 5884 5885 5886 5887 5888 5889 5890 5891 5892 5893 5894 5895 5896 5897 5898 5899 5900 5901 5902 5903 5904 5905
	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. */
5906
	if (test_pages_isolated(outer_start, end, false)) {
5907 5908 5909 5910 5911 5912
		pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
		       outer_start, end);
		ret = -EBUSY;
		goto done;
	}

5913 5914

	/* Grab isolated pages from freelists. */
5915
	outer_end = isolate_freepages_range(&cc, outer_start, end);
5916 5917 5918 5919 5920 5921 5922 5923 5924 5925 5926 5927 5928
	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),
5929
				pfn_max_align_up(end), migratetype);
5930 5931 5932 5933 5934
	return ret;
}

void free_contig_range(unsigned long pfn, unsigned nr_pages)
{
5935 5936 5937 5938 5939 5940 5941 5942 5943
	unsigned int count = 0;

	for (; nr_pages--; pfn++) {
		struct page *page = pfn_to_page(pfn);

		count += page_count(page) != 1;
		__free_page(page);
	}
	WARN(count != 0, "%d pages are still in use!\n", count);
5944 5945 5946
}
#endif

5947 5948 5949 5950 5951 5952 5953 5954 5955 5956 5957 5958 5959 5960 5961 5962 5963
#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);
5964
		drain_zonestat(zone, pset);
5965 5966 5967 5968 5969 5970 5971 5972 5973 5974 5975 5976
		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

5977 5978 5979
void zone_pcp_reset(struct zone *zone)
{
	unsigned long flags;
5980 5981
	int cpu;
	struct per_cpu_pageset *pset;
5982 5983 5984 5985

	/* avoid races with drain_pages()  */
	local_irq_save(flags);
	if (zone->pageset != &boot_pageset) {
5986 5987 5988 5989
		for_each_online_cpu(cpu) {
			pset = per_cpu_ptr(zone->pageset, cpu);
			drain_zonestat(zone, pset);
		}
5990 5991 5992 5993 5994 5995
		free_percpu(zone->pageset);
		zone->pageset = &boot_pageset;
	}
	local_irq_restore(flags);
}

5996
#ifdef CONFIG_MEMORY_HOTREMOVE
K
KAMEZAWA Hiroyuki 已提交
5997 5998 5999 6000 6001 6002 6003 6004 6005 6006 6007 6008 6009 6010 6011 6012 6013 6014 6015 6016 6017 6018 6019 6020 6021 6022
/*
 * 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);
6023 6024 6025 6026 6027 6028 6029 6030 6031 6032
		/*
		 * 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
6033 6034 6035 6036 6037 6038 6039 6040 6041 6042 6043 6044 6045 6046 6047 6048 6049
		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
6050 6051 6052 6053 6054 6055 6056 6057 6058 6059 6060 6061 6062 6063 6064 6065 6066 6067 6068 6069 6070

#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
6071

A
Andrew Morton 已提交
6072
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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}