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linux/mm/page_alloc.c
Mel Gorman 9ee493ce0a mm: page allocator: drain per-cpu lists after direct reclaim allocation fails 
When under significant memory pressure, a process enters direct reclaim
and immediately afterwards tries to allocate a page.  If it fails and no
further progress is made, it's possible the system will go OOM.  However,
on systems with large amounts of memory, it's possible that a significant
number of pages are on per-cpu lists and inaccessible to the calling
process.  This leads to a process entering direct reclaim more often than
it should increasing the pressure on the system and compounding the
problem.

This patch notes that if direct reclaim is making progress but allocations
are still failing that the system is already under heavy pressure.  In
this case, it drains the per-cpu lists and tries the allocation a second
time before continuing.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09 18:57:25 -07:00

5510 lines
151 KiB
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/*
* linux/mm/page_alloc.c
*
* Manages the free list, the system allocates free pages here.
* Note that kmalloc() lives in slab.c
*
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
* Swap reorganised 29.12.95, Stephen Tweedie
* Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
* Reshaped it to be a zoned allocator, Ingo Molnar, Red Hat, 1999
* Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999
* Zone balancing, Kanoj Sarcar, SGI, Jan 2000
* Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
* (lots of bits borrowed from Ingo Molnar & Andrew Morton)
*/
#include <linux/stddef.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/interrupt.h>
#include <linux/pagemap.h>
#include <linux/jiffies.h>
#include <linux/bootmem.h>
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/kmemcheck.h>
#include <linux/module.h>
#include <linux/suspend.h>
#include <linux/pagevec.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/oom.h>
#include <linux/notifier.h>
#include <linux/topology.h>
#include <linux/sysctl.h>
#include <linux/cpu.h>
#include <linux/cpuset.h>
#include <linux/memory_hotplug.h>
#include <linux/nodemask.h>
#include <linux/vmalloc.h>
#include <linux/mempolicy.h>
#include <linux/stop_machine.h>
#include <linux/sort.h>
#include <linux/pfn.h>
#include <linux/backing-dev.h>
#include <linux/fault-inject.h>
#include <linux/page-isolation.h>
#include <linux/page_cgroup.h>
#include <linux/debugobjects.h>
#include <linux/kmemleak.h>
#include <linux/memory.h>
#include <linux/compaction.h>
#include <trace/events/kmem.h>
#include <linux/ftrace_event.h>
#include <asm/tlbflush.h>
#include <asm/div64.h>
#include "internal.h"
#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
DEFINE_PER_CPU(int, numa_node);
EXPORT_PER_CPU_SYMBOL(numa_node);
#endif
#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
/*
* Array of node states.
*/
nodemask_t node_states[NR_NODE_STATES] __read_mostly = {
[N_POSSIBLE] = NODE_MASK_ALL,
[N_ONLINE] = { { [0] = 1UL } },
#ifndef CONFIG_NUMA
[N_NORMAL_MEMORY] = { { [0] = 1UL } },
#ifdef CONFIG_HIGHMEM
[N_HIGH_MEMORY] = { { [0] = 1UL } },
#endif
[N_CPU] = { { [0] = 1UL } },
#endif /* NUMA */
};
EXPORT_SYMBOL(node_states);
unsigned long totalram_pages __read_mostly;
unsigned long totalreserve_pages __read_mostly;
int percpu_pagelist_fraction;
gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
#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).
*/
void set_gfp_allowed_mask(gfp_t mask)
{
WARN_ON(!mutex_is_locked(&pm_mutex));
gfp_allowed_mask = mask;
}
gfp_t clear_gfp_allowed_mask(gfp_t mask)
{
gfp_t ret = gfp_allowed_mask;
WARN_ON(!mutex_is_locked(&pm_mutex));
gfp_allowed_mask &= ~mask;
return ret;
}
#endif /* CONFIG_PM_SLEEP */
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
int pageblock_order __read_mostly;
#endif
static void __free_pages_ok(struct page *page, unsigned int order);
/*
* 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
*
* TBD: should special case ZONE_DMA32 machines here - in those we normally
* don't need any ZONE_NORMAL reservation
*/
int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
#ifdef CONFIG_ZONE_DMA
256,
#endif
#ifdef CONFIG_ZONE_DMA32
256,
#endif
#ifdef CONFIG_HIGHMEM
32,
#endif
32,
};
EXPORT_SYMBOL(totalram_pages);
static char * const zone_names[MAX_NR_ZONES] = {
#ifdef CONFIG_ZONE_DMA
"DMA",
#endif
#ifdef CONFIG_ZONE_DMA32
"DMA32",
#endif
"Normal",
#ifdef CONFIG_HIGHMEM
"HighMem",
#endif
"Movable",
};
int min_free_kbytes = 1024;
static unsigned long __meminitdata nr_kernel_pages;
static unsigned long __meminitdata nr_all_pages;
static unsigned long __meminitdata dma_reserve;
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
/*
* MAX_ACTIVE_REGIONS determines the maximum number of distinct
* ranges of memory (RAM) that may be registered with add_active_range().
* Ranges passed to add_active_range() will be merged if possible
* so the number of times add_active_range() can be called is
* related to the number of nodes and the number of holes
*/
#ifdef CONFIG_MAX_ACTIVE_REGIONS
/* Allow an architecture to set MAX_ACTIVE_REGIONS to save memory */
#define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
#else
#if MAX_NUMNODES >= 32
/* If there can be many nodes, allow up to 50 holes per node */
#define MAX_ACTIVE_REGIONS (MAX_NUMNODES*50)
#else
/* By default, allow up to 256 distinct regions */
#define MAX_ACTIVE_REGIONS 256
#endif
#endif
static struct node_active_region __meminitdata early_node_map[MAX_ACTIVE_REGIONS];
static int __meminitdata nr_nodemap_entries;
static unsigned long __meminitdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
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_ARCH_POPULATES_NODE_MAP */
#if MAX_NUMNODES > 1
int nr_node_ids __read_mostly = MAX_NUMNODES;
int nr_online_nodes __read_mostly = 1;
EXPORT_SYMBOL(nr_node_ids);
EXPORT_SYMBOL(nr_online_nodes);
#endif
int page_group_by_mobility_disabled __read_mostly;
static void set_pageblock_migratetype(struct page *page, int migratetype)
{
if (unlikely(page_group_by_mobility_disabled))
migratetype = MIGRATE_UNMOVABLE;
set_pageblock_flags_group(page, (unsigned long)migratetype,
PB_migrate, PB_migrate_end);
}
bool oom_killer_disabled __read_mostly;
#ifdef CONFIG_DEBUG_VM
static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
{
int ret = 0;
unsigned seq;
unsigned long pfn = page_to_pfn(page);
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;
}
static int page_is_consistent(struct zone *zone, struct page *page)
{
if (!pfn_valid_within(page_to_pfn(page)))
return 0;
if (zone != page_zone(page))
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))
return 1;
if (!page_is_consistent(zone, page))
return 1;
return 0;
}
#else
static inline int bad_range(struct zone *zone, struct page *page)
{
return 0;
}
#endif
static void bad_page(struct page *page)
{
static unsigned long resume;
static unsigned long nr_shown;
static unsigned long nr_unshown;
/* Don't complain about poisoned pages */
if (PageHWPoison(page)) {
__ClearPageBuddy(page);
return;
}
/*
* 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) {
printk(KERN_ALERT
"BUG: Bad page state: %lu messages suppressed\n",
nr_unshown);
nr_unshown = 0;
}
nr_shown = 0;
}
if (nr_shown++ == 0)
resume = jiffies + 60 * HZ;
printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
current->comm, page_to_pfn(page));
dump_page(page);
dump_stack();
out:
/* Leave bad fields for debug, except PageBuddy could make trouble */
__ClearPageBuddy(page);
add_taint(TAINT_BAD_PAGE);
}
/*
* Higher-order pages are called "compound pages". They are structured thusly:
*
* The first PAGE_SIZE page is called the "head page".
*
* The remaining PAGE_SIZE pages are called "tail pages".
*
* All pages have PG_compound set. All pages have their ->private pointing at
* the head page (even the head page has this).
*
* 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.
*/
static void free_compound_page(struct page *page)
{
__free_pages_ok(page, compound_order(page));
}
void prep_compound_page(struct page *page, unsigned long order)
{
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);
p->first_page = page;
}
}
static int destroy_compound_page(struct page *page, unsigned long order)
{
int i;
int nr_pages = 1 << order;
int bad = 0;
if (unlikely(compound_order(page) != order) ||
unlikely(!PageHead(page))) {
bad_page(page);
bad++;
}
__ClearPageHead(page);
for (i = 1; i < nr_pages; i++) {
struct page *p = page + i;
if (unlikely(!PageTail(p) || (p->first_page != page))) {
bad_page(page);
bad++;
}
__ClearPageTail(p);
}
return bad;
}
static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
{
int i;
/*
* clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
* and __GFP_HIGHMEM from hard or soft interrupt context.
*/
VM_BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
for (i = 0; i < (1 << order); i++)
clear_highpage(page + i);
}
static inline void set_page_order(struct page *page, int order)
{
set_page_private(page, order);
__SetPageBuddy(page);
}
static inline void rmv_page_order(struct page *page)
{
__ClearPageBuddy(page);
set_page_private(page, 0);
}
/*
* 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)
*
* Assumption: *_mem_map is contiguous at least up to MAX_ORDER
*/
static inline struct page *
__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order)
{
unsigned long buddy_idx = page_idx ^ (1 << order);
return page + (buddy_idx - page_idx);
}
static inline unsigned long
__find_combined_index(unsigned long page_idx, unsigned int order)
{
return (page_idx & ~(1 << order));
}
/*
* This function checks whether a page is free && is the buddy
* we can do coalesce a page and its buddy if
* (a) the buddy is not in a hole &&
* (b) the buddy is in the buddy system &&
* (c) a page and its buddy have the same order &&
* (d) a page and its buddy are in the same zone.
*
* For recording whether a page is in the buddy system, we use PG_buddy.
* Setting, clearing, and testing PG_buddy is serialized by zone->lock.
*
* For recording page's order, we use page_private(page).
*/
static inline int page_is_buddy(struct page *page, struct page *buddy,
int order)
{
if (!pfn_valid_within(page_to_pfn(buddy)))
return 0;
if (page_zone_id(page) != page_zone_id(buddy))
return 0;
if (PageBuddy(buddy) && page_order(buddy) == order) {
VM_BUG_ON(page_count(buddy) != 0);
return 1;
}
return 0;
}
/*
* 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
* free pages of length of (1 << order) and marked with PG_buddy. Page's
* order is recorded in page_private(page) field.
* So when we are allocating or freeing one, we can derive the state of the
* other. That is, if we allocate a small block, and both were
* free, the remainder of the region must be split into blocks.
* If a block is freed, and its buddy is also free, then this
* triggers coalescing into a block of larger size.
*
* -- wli
*/
static inline void __free_one_page(struct page *page,
struct zone *zone, unsigned int order,
int migratetype)
{
unsigned long page_idx;
unsigned long combined_idx;
struct page *buddy;
if (unlikely(PageCompound(page)))
if (unlikely(destroy_compound_page(page, order)))
return;
VM_BUG_ON(migratetype == -1);
page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
VM_BUG_ON(page_idx & ((1 << order) - 1));
VM_BUG_ON(bad_range(zone, page));
while (order < MAX_ORDER-1) {
buddy = __page_find_buddy(page, page_idx, order);
if (!page_is_buddy(page, buddy, order))
break;
/* Our buddy is free, merge with it and move up one order. */
list_del(&buddy->lru);
zone->free_area[order].nr_free--;
rmv_page_order(buddy);
combined_idx = __find_combined_index(page_idx, order);
page = page + (combined_idx - page_idx);
page_idx = combined_idx;
order++;
}
set_page_order(page, order);
/*
* 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
*/
if ((order < MAX_ORDER-1) && pfn_valid_within(page_to_pfn(buddy))) {
struct page *higher_page, *higher_buddy;
combined_idx = __find_combined_index(page_idx, order);
higher_page = page + combined_idx - page_idx;
higher_buddy = __page_find_buddy(higher_page, combined_idx, order + 1);
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:
zone->free_area[order].nr_free++;
}
/*
* free_page_mlock() -- clean up attempts to free and mlocked() page.
* Page should not be on lru, so no need to fix that up.
* free_pages_check() will verify...
*/
static inline void free_page_mlock(struct page *page)
{
__dec_zone_page_state(page, NR_MLOCK);
__count_vm_event(UNEVICTABLE_MLOCKFREED);
}
static inline int free_pages_check(struct page *page)
{
if (unlikely(page_mapcount(page) |
(page->mapping != NULL) |
(atomic_read(&page->_count) != 0) |
(page->flags & PAGE_FLAGS_CHECK_AT_FREE))) {
bad_page(page);
return 1;
}
if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
return 0;
}
/*
* Frees a number of pages from the PCP lists
* Assumes all pages on list are in same zone, and of same order.
* count is the number of pages to free.
*
* 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.
*/
static void free_pcppages_bulk(struct zone *zone, int count,
struct per_cpu_pages *pcp)
{
int migratetype = 0;
int batch_free = 0;
int to_free = count;
spin_lock(&zone->lock);
zone->all_unreclaimable = 0;
zone->pages_scanned = 0;
while (to_free) {
struct page *page;
struct list_head *list;
/*
* 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
*/
do {
batch_free++;
if (++migratetype == MIGRATE_PCPTYPES)
migratetype = 0;
list = &pcp->lists[migratetype];
} while (list_empty(list));
do {
page = list_entry(list->prev, struct page, lru);
/* must delete as __free_one_page list manipulates */
list_del(&page->lru);
/* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
__free_one_page(page, zone, 0, page_private(page));
trace_mm_page_pcpu_drain(page, 0, page_private(page));
} while (--to_free && --batch_free && !list_empty(list));
}
__mod_zone_page_state(zone, NR_FREE_PAGES, count);
spin_unlock(&zone->lock);
}
static void free_one_page(struct zone *zone, struct page *page, int order,
int migratetype)
{
spin_lock(&zone->lock);
zone->all_unreclaimable = 0;
zone->pages_scanned = 0;
__free_one_page(page, zone, order, migratetype);
__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
spin_unlock(&zone->lock);
}
static bool free_pages_prepare(struct page *page, unsigned int order)
{
int i;
int bad = 0;
trace_mm_page_free_direct(page, order);
kmemcheck_free_shadow(page, order);
for (i = 0; i < (1 << order); i++) {
struct page *pg = page + i;
if (PageAnon(pg))
pg->mapping = NULL;
bad += free_pages_check(pg);
}
if (bad)
return false;
if (!PageHighMem(page)) {
debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
debug_check_no_obj_freed(page_address(page),
PAGE_SIZE << order);
}
arch_free_page(page, order);
kernel_map_pages(page, 1 << order, 0);
return true;
}
static void __free_pages_ok(struct page *page, unsigned int order)
{
unsigned long flags;
int wasMlocked = __TestClearPageMlocked(page);
if (!free_pages_prepare(page, order))
return;
local_irq_save(flags);
if (unlikely(wasMlocked))
free_page_mlock(page);
__count_vm_events(PGFREE, 1 << order);
free_one_page(page_zone(page), page, order,
get_pageblock_migratetype(page));
local_irq_restore(flags);
}
/*
* permit the bootmem allocator to evade page validation on high-order frees
*/
void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
{
if (order == 0) {
__ClearPageReserved(page);
set_page_count(page, 0);
set_page_refcounted(page);
__free_page(page);
} else {
int loop;
prefetchw(page);
for (loop = 0; loop < BITS_PER_LONG; loop++) {
struct page *p = &page[loop];
if (loop + 1 < BITS_PER_LONG)
prefetchw(p + 1);
__ClearPageReserved(p);
set_page_count(p, 0);
}
set_page_refcounted(page);
__free_pages(page, order);
}
}
/*
* The order of subdivision here is critical for the IO subsystem.
* Please do not alter this order without good reasons and regression
* testing. Specifically, as large blocks of memory are subdivided,
* the order in which smaller blocks are delivered depends on the order
* they're subdivided in this function. This is the primary factor
* influencing the order in which pages are delivered to the IO
* subsystem according to empirical testing, and this is also justified
* by considering the behavior of a buddy system containing a single
* large block of memory acted on by a series of small allocations.
* This behavior is a critical factor in sglist merging's success.
*
* -- wli
*/
static inline void expand(struct zone *zone, struct page *page,
int low, int high, struct free_area *area,
int migratetype)
{
unsigned long size = 1 << high;
while (high > low) {
area--;
high--;
size >>= 1;
VM_BUG_ON(bad_range(zone, &page[size]));
list_add(&page[size].lru, &area->free_list[migratetype]);
area->nr_free++;
set_page_order(&page[size], high);
}
}
/*
* This page is about to be returned from the page allocator
*/
static inline int check_new_page(struct page *page)
{
if (unlikely(page_mapcount(page) |
(page->mapping != NULL) |
(atomic_read(&page->_count) != 0) |
(page->flags & PAGE_FLAGS_CHECK_AT_PREP))) {
bad_page(page);
return 1;
}
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;
}
set_page_private(page, 0);
set_page_refcounted(page);
arch_alloc_page(page, order);
kernel_map_pages(page, 1 << order, 1);
if (gfp_flags & __GFP_ZERO)
prep_zero_page(page, order, gfp_flags);
if (order && (gfp_flags & __GFP_COMP))
prep_compound_page(page, order);
return 0;
}
/*
* Go through the free lists for the given migratetype and remove
* the smallest available page from the freelists
*/
static inline
struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
int migratetype)
{
unsigned int current_order;
struct free_area * area;
struct page *page;
/* Find a page of the appropriate size in the preferred list */
for (current_order = order; current_order < MAX_ORDER; ++current_order) {
area = &(zone->free_area[current_order]);
if (list_empty(&area->free_list[migratetype]))
continue;
page = list_entry(area->free_list[migratetype].next,
struct page, lru);
list_del(&page->lru);
rmv_page_order(page);
area->nr_free--;
expand(zone, page, order, current_order, area, migratetype);
return page;
}
return NULL;
}
/*
* This array describes the order lists are fallen back to when
* the free lists for the desirable migrate type are depleted
*/
static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
[MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
[MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
[MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
[MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */
};
/*
* Move the free pages in a range to the free lists of the requested type.
* Note that start_page and end_pages are not aligned on a pageblock
* boundary. If alignment is required, use move_freepages_block()
*/
static int move_freepages(struct zone *zone,
struct page *start_page, struct page *end_page,
int migratetype)
{
struct page *page;
unsigned long order;
int pages_moved = 0;
#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
* grouping pages by mobility
*/
BUG_ON(page_zone(start_page) != page_zone(end_page));
#endif
for (page = start_page; page <= end_page;) {
/* Make sure we are not inadvertently changing nodes */
VM_BUG_ON(page_to_nid(page) != zone_to_nid(zone));
if (!pfn_valid_within(page_to_pfn(page))) {
page++;
continue;
}
if (!PageBuddy(page)) {
page++;
continue;
}
order = page_order(page);
list_del(&page->lru);
list_add(&page->lru,
&zone->free_area[order].free_list[migratetype]);
page += 1 << order;
pages_moved += 1 << order;
}
return pages_moved;
}
static int move_freepages_block(struct zone *zone, struct page *page,
int migratetype)
{
unsigned long start_pfn, end_pfn;
struct page *start_page, *end_page;
start_pfn = page_to_pfn(page);
start_pfn = start_pfn & ~(pageblock_nr_pages-1);
start_page = pfn_to_page(start_pfn);
end_page = start_page + pageblock_nr_pages - 1;
end_pfn = start_pfn + pageblock_nr_pages - 1;
/* 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);
}
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;
}
}
/* Remove an element from the buddy allocator from the fallback list */
static inline struct page *
__rmqueue_fallback(struct zone *zone, int order, int start_migratetype)
{
struct free_area * area;
int current_order;
struct page *page;
int migratetype, i;
/* Find the largest possible block of pages in the other list */
for (current_order = MAX_ORDER-1; current_order >= order;
--current_order) {
for (i = 0; i < MIGRATE_TYPES - 1; i++) {
migratetype = fallbacks[start_migratetype][i];
/* MIGRATE_RESERVE handled later if necessary */
if (migratetype == MIGRATE_RESERVE)
continue;
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--;
/*
* If breaking a large block of pages, move all free
* pages to the preferred allocation list. If falling
* back for a reclaimable kernel allocation, be more
* agressive about taking ownership of free pages
*/
if (unlikely(current_order >= (pageblock_order >> 1)) ||
start_migratetype == MIGRATE_RECLAIMABLE ||
page_group_by_mobility_disabled) {
unsigned long pages;
pages = move_freepages_block(zone, page,
start_migratetype);
/* Claim the whole block if over half of it is free */
if (pages >= (1 << (pageblock_order-1)) ||
page_group_by_mobility_disabled)
set_pageblock_migratetype(page,
start_migratetype);
migratetype = start_migratetype;
}
/* Remove the page from the freelists */
list_del(&page->lru);
rmv_page_order(page);
/* Take ownership for orders >= pageblock_order */
if (current_order >= pageblock_order)
change_pageblock_range(page, current_order,
start_migratetype);
expand(zone, page, order, current_order, area, migratetype);
trace_mm_page_alloc_extfrag(page, order, current_order,
start_migratetype, migratetype);
return page;
}
}
return NULL;
}
/*
* Do the hard work of removing an element from the buddy allocator.
* Call me with the zone->lock already held.
*/
static struct page *__rmqueue(struct zone *zone, unsigned int order,
int migratetype)
{
struct page *page;
retry_reserve:
page = __rmqueue_smallest(zone, order, migratetype);
if (unlikely(!page) && migratetype != MIGRATE_RESERVE) {
page = __rmqueue_fallback(zone, order, migratetype);
/*
* 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;
}
}
trace_mm_page_alloc_zone_locked(page, order, migratetype);
return page;
}
/*
* Obtain a specified number of elements from the buddy allocator, all under
* a single hold of the lock, for efficiency. Add them to the supplied list.
* Returns the number of new pages which were placed at *list.
*/
static int rmqueue_bulk(struct zone *zone, unsigned int order,
unsigned long count, struct list_head *list,
int migratetype, int cold)
{
int i;
spin_lock(&zone->lock);
for (i = 0; i < count; ++i) {
struct page *page = __rmqueue(zone, order, migratetype);
if (unlikely(page == NULL))
break;
/*
* 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.
*/
if (likely(cold == 0))
list_add(&page->lru, list);
else
list_add_tail(&page->lru, list);
set_page_private(page, migratetype);
list = &page->lru;
}
__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
spin_unlock(&zone->lock);
return i;
}
#ifdef CONFIG_NUMA
/*
* Called from the vmstat counter updater to drain pagesets of this
* currently executing processor on remote nodes after they have
* expired.
*
* Note that this function must be called with the thread pinned to
* a single processor.
*/
void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
{
unsigned long flags;
int to_drain;
local_irq_save(flags);
if (pcp->count >= pcp->batch)
to_drain = pcp->batch;
else
to_drain = pcp->count;
free_pcppages_bulk(zone, to_drain, pcp);
pcp->count -= to_drain;
local_irq_restore(flags);
}
#endif
/*
* 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)
{
unsigned long flags;
struct zone *zone;
for_each_populated_zone(zone) {
struct per_cpu_pageset *pset;
struct per_cpu_pages *pcp;
local_irq_save(flags);
pset = per_cpu_ptr(zone->pageset, cpu);
pcp = &pset->pcp;
free_pcppages_bulk(zone, pcp->count, pcp);
pcp->count = 0;
local_irq_restore(flags);
}
}
/*
* Spill all of this CPU's per-cpu pages back into the buddy allocator.
*/
void drain_local_pages(void *arg)
{
drain_pages(smp_processor_id());
}
/*
* Spill all the per-cpu pages from all CPUs back into the buddy allocator
*/
void drain_all_pages(void)
{
on_each_cpu(drain_local_pages, NULL, 1);
}
#ifdef CONFIG_HIBERNATION
void mark_free_pages(struct zone *zone)
{
unsigned long pfn, max_zone_pfn;
unsigned long flags;
int order, t;
struct list_head *curr;
if (!zone->spanned_pages)
return;
spin_lock_irqsave(&zone->lock, flags);
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);
if (!swsusp_page_is_forbidden(page))
swsusp_unset_page_free(page);
}
for_each_migratetype_order(order, t) {
list_for_each(curr, &zone->free_area[order].free_list[t]) {
unsigned long i;
pfn = page_to_pfn(list_entry(curr, struct page, lru));
for (i = 0; i < (1UL << order); i++)
swsusp_set_page_free(pfn_to_page(pfn + i));
}
}
spin_unlock_irqrestore(&zone->lock, flags);
}
#endif /* CONFIG_PM */
/*
* Free a 0-order page
* cold == 1 ? free a cold page : free a hot page
*/
void free_hot_cold_page(struct page *page, int cold)
{
struct zone *zone = page_zone(page);
struct per_cpu_pages *pcp;
unsigned long flags;
int migratetype;
int wasMlocked = __TestClearPageMlocked(page);
if (!free_pages_prepare(page, 0))
return;
migratetype = get_pageblock_migratetype(page);
set_page_private(page, migratetype);
local_irq_save(flags);
if (unlikely(wasMlocked))
free_page_mlock(page);
__count_vm_event(PGFREE);
/*
* 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;
}
pcp = &this_cpu_ptr(zone->pageset)->pcp;
if (cold)
list_add_tail(&page->lru, &pcp->lists[migratetype]);
else
list_add(&page->lru, &pcp->lists[migratetype]);
pcp->count++;
if (pcp->count >= pcp->high) {
free_pcppages_bulk(zone, pcp->batch, pcp);
pcp->count -= pcp->batch;
}
out:
local_irq_restore(flags);
}
/*
* 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;
VM_BUG_ON(PageCompound(page));
VM_BUG_ON(!page_count(page));
#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
for (i = 1; i < (1 << order); i++)
set_page_refcounted(page + i);
}
/*
* 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;
unsigned long watermark;
struct zone *zone;
BUG_ON(!PageBuddy(page));
zone = page_zone(page);
order = page_order(page);
/* Obey watermarks as if the page was being allocated */
watermark = low_wmark_pages(zone) + (1 << order);
if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
return 0;
/* Remove page from free list */
list_del(&page->lru);
zone->free_area[order].nr_free--;
rmv_page_order(page);
__mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));
/* Split into individual pages */
set_page_refcounted(page);
split_page(page, order);
if (order >= pageblock_order - 1) {
struct page *endpage = page + (1 << order) - 1;
for (; page < endpage; page += pageblock_nr_pages)
set_pageblock_migratetype(page, MIGRATE_MOVABLE);
}
return 1 << order;
}
/*
* 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.
*/
static inline
struct page *buffered_rmqueue(struct zone *preferred_zone,
struct zone *zone, int order, gfp_t gfp_flags,
int migratetype)
{
unsigned long flags;
struct page *page;
int cold = !!(gfp_flags & __GFP_COLD);
again:
if (likely(order == 0)) {
struct per_cpu_pages *pcp;
struct list_head *list;
local_irq_save(flags);
pcp = &this_cpu_ptr(zone->pageset)->pcp;
list = &pcp->lists[migratetype];
if (list_empty(list)) {
pcp->count += rmqueue_bulk(zone, 0,
pcp->batch, list,
migratetype, cold);
if (unlikely(list_empty(list)))
goto failed;
}
if (cold)
page = list_entry(list->prev, struct page, lru);
else
page = list_entry(list->next, struct page, lru);
list_del(&page->lru);
pcp->count--;
} else {
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
* allocate greater than order-1 page units with
* __GFP_NOFAIL.
*/
WARN_ON_ONCE(order > 1);
}
spin_lock_irqsave(&zone->lock, flags);
page = __rmqueue(zone, order, migratetype);
spin_unlock(&zone->lock);
if (!page)
goto failed;
__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
}
__count_zone_vm_events(PGALLOC, zone, 1 << order);
zone_statistics(preferred_zone, zone);
local_irq_restore(flags);
VM_BUG_ON(bad_range(zone, page));
if (prep_new_page(page, order, gfp_flags))
goto again;
return page;
failed:
local_irq_restore(flags);
return NULL;
}
/* The ALLOC_WMARK bits are used as an index to zone->watermark */
#define ALLOC_WMARK_MIN WMARK_MIN
#define ALLOC_WMARK_LOW WMARK_LOW
#define ALLOC_WMARK_HIGH WMARK_HIGH
#define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
/* Mask to get the watermark bits */
#define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
#define ALLOC_HARDER 0x10 /* try to alloc harder */
#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
#define ALLOC_CPUSET 0x40 /* check for correct cpuset */
#ifdef CONFIG_FAIL_PAGE_ALLOC
static struct fail_page_alloc_attr {
struct fault_attr attr;
u32 ignore_gfp_highmem;
u32 ignore_gfp_wait;
u32 min_order;
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
struct dentry *ignore_gfp_highmem_file;
struct dentry *ignore_gfp_wait_file;
struct dentry *min_order_file;
#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
} fail_page_alloc = {
.attr = FAULT_ATTR_INITIALIZER,
.ignore_gfp_wait = 1,
.ignore_gfp_highmem = 1,
.min_order = 1,
};
static int __init setup_fail_page_alloc(char *str)
{
return setup_fault_attr(&fail_page_alloc.attr, str);
}
__setup("fail_page_alloc=", setup_fail_page_alloc);
static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
{
if (order < fail_page_alloc.min_order)
return 0;
if (gfp_mask & __GFP_NOFAIL)
return 0;
if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
return 0;
if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
return 0;
return should_fail(&fail_page_alloc.attr, 1 << order);
}
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
static int __init fail_page_alloc_debugfs(void)
{
mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
struct dentry *dir;
int err;
err = init_fault_attr_dentries(&fail_page_alloc.attr,
"fail_page_alloc");
if (err)
return err;
dir = fail_page_alloc.attr.dentries.dir;
fail_page_alloc.ignore_gfp_wait_file =
debugfs_create_bool("ignore-gfp-wait", mode, dir,
&fail_page_alloc.ignore_gfp_wait);
fail_page_alloc.ignore_gfp_highmem_file =
debugfs_create_bool("ignore-gfp-highmem", mode, dir,
&fail_page_alloc.ignore_gfp_highmem);
fail_page_alloc.min_order_file =
debugfs_create_u32("min-order", mode, dir,
&fail_page_alloc.min_order);
if (!fail_page_alloc.ignore_gfp_wait_file ||
!fail_page_alloc.ignore_gfp_highmem_file ||
!fail_page_alloc.min_order_file) {
err = -ENOMEM;
debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
debugfs_remove(fail_page_alloc.min_order_file);
cleanup_fault_attr_dentries(&fail_page_alloc.attr);
}
return err;
}
late_initcall(fail_page_alloc_debugfs);
#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
#else /* CONFIG_FAIL_PAGE_ALLOC */
static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
{
return 0;
}
#endif /* CONFIG_FAIL_PAGE_ALLOC */
/*
* Return 1 if free pages are above 'mark'. This takes into account the order
* of the allocation.
*/
int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
int classzone_idx, int alloc_flags)
{
/* free_pages my go negative - that's OK */
long min = mark;
long free_pages = zone_nr_free_pages(z) - (1 << order) + 1;
int o;
if (alloc_flags & ALLOC_HIGH)
min -= min / 2;
if (alloc_flags & ALLOC_HARDER)
min -= min / 4;
if (free_pages <= min + z->lowmem_reserve[classzone_idx])
return 0;
for (o = 0; o < order; o++) {
/* At the next order, this order's pages become unavailable */
free_pages -= z->free_area[o].nr_free << o;
/* Require fewer higher order pages to be free */
min >>= 1;
if (free_pages <= min)
return 0;
}
return 1;
}
#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
* that have to skip over a lot of full or unallowed zones.
*
* If the zonelist cache is present in the passed in zonelist, then
* returns a pointer to the allowed node mask (either the current
* tasks mems_allowed, or node_states[N_HIGH_MEMORY].)
*
* If the zonelist cache is not available for this zonelist, does
* nothing and returns NULL.
*
* If the fullzones BITMAP in the zonelist cache is stale (more than
* a second since last zap'd) then we zap it out (clear its bits.)
*
* We hold off even calling zlc_setup, until after we've checked the
* first zone in the zonelist, on the theory that most allocations will
* be satisfied from that first zone, so best to examine that zone as
* quickly as we can.
*/
static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
{
struct zonelist_cache *zlc; /* cached zonelist speedup info */
nodemask_t *allowednodes; /* zonelist_cache approximation */
zlc = zonelist->zlcache_ptr;
if (!zlc)
return NULL;
if (time_after(jiffies, zlc->last_full_zap + HZ)) {
bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
zlc->last_full_zap = jiffies;
}
allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ?
&cpuset_current_mems_allowed :
&node_states[N_HIGH_MEMORY];
return allowednodes;
}
/*
* Given 'z' scanning a zonelist, run a couple of quick checks to see
* if it is worth looking at further for free memory:
* 1) Check that the zone isn't thought to be full (doesn't have its
* bit set in the zonelist_cache fullzones BITMAP).
* 2) Check that the zones node (obtained from the zonelist_cache
* z_to_n[] mapping) is allowed in the passed in allowednodes mask.
* Return true (non-zero) if zone is worth looking at further, or
* else return false (zero) if it is not.
*
* This check -ignores- the distinction between various watermarks,
* such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is
* found to be full for any variation of these watermarks, it will
* be considered full for up to one second by all requests, unless
* we are so low on memory on all allowed nodes that we are forced
* into the second scan of the zonelist.
*
* In the second scan we ignore this zonelist cache and exactly
* apply the watermarks to all zones, even it is slower to do so.
* We are low on memory in the second scan, and should leave no stone
* unturned looking for a free page.
*/
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
nodemask_t *allowednodes)
{
struct zonelist_cache *zlc; /* cached zonelist speedup info */
int i; /* index of *z in zonelist zones */
int n; /* node that zone *z is on */
zlc = zonelist->zlcache_ptr;
if (!zlc)
return 1;
i = z - zonelist->_zonerefs;
n = zlc->z_to_n[i];
/* This zone is worth trying if it is allowed but not full */
return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones);
}
/*
* Given 'z' scanning a zonelist, set the corresponding bit in
* zlc->fullzones, so that subsequent attempts to allocate a page
* from that zone don't waste time re-examining it.
*/
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
{
struct zonelist_cache *zlc; /* cached zonelist speedup info */
int i; /* index of *z in zonelist zones */
zlc = zonelist->zlcache_ptr;
if (!zlc)
return;
i = z - zonelist->_zonerefs;
set_bit(i, zlc->fullzones);
}
#else /* CONFIG_NUMA */
static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
{
return NULL;
}
static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
nodemask_t *allowednodes)
{
return 1;
}
static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
{
}
#endif /* CONFIG_NUMA */
/*
* get_page_from_freelist goes through the zonelist trying to allocate
* a page.
*/
static struct page *
get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order,
struct zonelist *zonelist, int high_zoneidx, int alloc_flags,
struct zone *preferred_zone, int migratetype)
{
struct zoneref *z;
struct page *page = NULL;
int classzone_idx;
struct zone *zone;
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 */
classzone_idx = zone_idx(preferred_zone);
zonelist_scan:
/*
* Scan zonelist, looking for a zone with enough free.
* See also cpuset_zone_allowed() comment in kernel/cpuset.c.
*/
for_each_zone_zonelist_nodemask(zone, z, zonelist,
high_zoneidx, nodemask) {
if (NUMA_BUILD && zlc_active &&
!zlc_zone_worth_trying(zonelist, z, allowednodes))
continue;
if ((alloc_flags & ALLOC_CPUSET) &&
!cpuset_zone_allowed_softwall(zone, gfp_mask))
goto try_next_zone;
BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
unsigned long mark;
int ret;
mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK];
if (zone_watermark_ok(zone, order, mark,
classzone_idx, alloc_flags))
goto try_this_zone;
if (zone_reclaim_mode == 0)
goto this_zone_full;
ret = zone_reclaim(zone, gfp_mask, order);
switch (ret) {
case ZONE_RECLAIM_NOSCAN:
/* did not scan */
goto try_next_zone;
case ZONE_RECLAIM_FULL:
/* scanned but unreclaimable */
goto this_zone_full;
default:
/* did we reclaim enough */
if (!zone_watermark_ok(zone, order, mark,
classzone_idx, alloc_flags))
goto this_zone_full;
}
}
try_this_zone:
page = buffered_rmqueue(preferred_zone, zone, order,
gfp_mask, migratetype);
if (page)
break;
this_zone_full:
if (NUMA_BUILD)
zlc_mark_zone_full(zonelist, z);
try_next_zone:
if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
/*
* we do zlc_setup after the first zone is tried but only
* if there are multiple nodes make it worthwhile
*/
allowednodes = zlc_setup(zonelist, alloc_flags);
zlc_active = 1;
did_zlc_setup = 1;
}
}
if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
/* Disable zlc cache for second zonelist scan */
zlc_active = 0;
goto zonelist_scan;
}
return page;
}
static inline int
should_alloc_retry(gfp_t gfp_mask, unsigned int order,
unsigned long pages_reclaimed)
{
/* Do not loop if specifically requested */
if (gfp_mask & __GFP_NORETRY)
return 0;
/*
* 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;
/*
* Don't let big-order allocations loop unless the caller
* explicitly requests that.
*/
if (gfp_mask & __GFP_NOFAIL)
return 1;
return 0;
}
static inline struct page *
__alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
struct zonelist *zonelist, enum zone_type high_zoneidx,
nodemask_t *nodemask, struct zone *preferred_zone,
int migratetype)
{
struct page *page;
/* Acquire the OOM killer lock for the zones in zonelist */
if (!try_set_zonelist_oom(zonelist, gfp_mask)) {
schedule_timeout_uninterruptible(1);
return NULL;
}
/*
* 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,
ALLOC_WMARK_HIGH|ALLOC_CPUSET,
preferred_zone, migratetype);
if (page)
goto out;
if (!(gfp_mask & __GFP_NOFAIL)) {
/* The OOM killer will not help higher order allocs */
if (order > PAGE_ALLOC_COSTLY_ORDER)
goto out;
/* The OOM killer does not needlessly kill tasks for lowmem */
if (high_zoneidx < ZONE_NORMAL)
goto out;
/*
* 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;
}
/* Exhausted what can be done so it's blamo time */
out_of_memory(zonelist, gfp_mask, order, nodemask);
out:
clear_zonelist_oom(zonelist, gfp_mask);
return page;
}
#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,
int migratetype, unsigned long *did_some_progress)
{
struct page *page;
if (!order || compaction_deferred(preferred_zone))
return NULL;
*did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
nodemask);
if (*did_some_progress != COMPACT_SKIPPED) {
/* 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,
alloc_flags, preferred_zone,
migratetype);
if (page) {
preferred_zone->compact_considered = 0;
preferred_zone->compact_defer_shift = 0;
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);
defer_compaction(preferred_zone);
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,
int migratetype, unsigned long *did_some_progress)
{
return NULL;
}
#endif /* CONFIG_COMPACTION */
/* 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;
struct reclaim_state reclaim_state;
struct task_struct *p = current;
bool drained = false;
cond_resched();
/* We now go into synchronous reclaim */
cpuset_memory_pressure_bump();
p->flags |= PF_MEMALLOC;
lockdep_set_current_reclaim_state(gfp_mask);
reclaim_state.reclaimed_slab = 0;
p->reclaim_state = &reclaim_state;
*did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
p->reclaim_state = NULL;
lockdep_clear_current_reclaim_state();
p->flags &= ~PF_MEMALLOC;
cond_resched();
if (unlikely(!(*did_some_progress)))
return NULL;
retry:
page = get_page_from_freelist(gfp_mask, nodemask, order,
zonelist, high_zoneidx,
alloc_flags, preferred_zone,
migratetype);
/*
* 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;
}
return page;
}
/*
* This is called in the allocator slow-path if the allocation request is of
* sufficient urgency to ignore watermarks and take other desperate measures
*/
static inline struct page *
__alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
struct zonelist *zonelist, enum zone_type high_zoneidx,
nodemask_t *nodemask, struct zone *preferred_zone,
int migratetype)
{
struct page *page;
do {
page = get_page_from_freelist(gfp_mask, nodemask, order,
zonelist, high_zoneidx, ALLOC_NO_WATERMARKS,
preferred_zone, migratetype);
if (!page && gfp_mask & __GFP_NOFAIL)
congestion_wait(BLK_RW_ASYNC, HZ/50);
} while (!page && (gfp_mask & __GFP_NOFAIL));
return page;
}
static inline
void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
enum zone_type high_zoneidx)
{
struct zoneref *z;
struct zone *zone;
for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
wakeup_kswapd(zone, order);
}
static inline int
gfp_to_alloc_flags(gfp_t gfp_mask)
{
struct task_struct *p = current;
int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
const gfp_t wait = gfp_mask & __GFP_WAIT;
/* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */
BUILD_BUG_ON(__GFP_HIGH != ALLOC_HIGH);
/*
* 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).
*/
alloc_flags |= (gfp_mask & __GFP_HIGH);
if (!wait) {
alloc_flags |= ALLOC_HARDER;
/*
* Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
* See also cpuset_zone_allowed() comment in kernel/cpuset.c.
*/
alloc_flags &= ~ALLOC_CPUSET;
} else if (unlikely(rt_task(p)) && !in_interrupt())
alloc_flags |= ALLOC_HARDER;
if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
if (!in_interrupt() &&
((p->flags & PF_MEMALLOC) ||
unlikely(test_thread_flag(TIF_MEMDIE))))
alloc_flags |= ALLOC_NO_WATERMARKS;
}
return alloc_flags;
}
static inline struct page *
__alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
struct zonelist *zonelist, enum zone_type high_zoneidx,
nodemask_t *nodemask, struct zone *preferred_zone,
int migratetype)
{
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;
struct task_struct *p = current;
/*
* 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.
*/
if (order >= MAX_ORDER) {
WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
return NULL;
}
/*
* GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and
* __GFP_NOWARN set) should not cause reclaim since the subsystem
* (f.e. slab) using GFP_THISNODE may choose to trigger reclaim
* using a larger set of nodes after it has established that the
* allowed per node queues are empty and that nodes are
* over allocated.
*/
if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE)
goto nopage;
restart:
wake_all_kswapd(order, zonelist, high_zoneidx);
/*
* 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.
*/
alloc_flags = gfp_to_alloc_flags(gfp_mask);
/* This is the last chance, in general, before the goto nopage. */
page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist,
high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS,
preferred_zone, migratetype);
if (page)
goto got_pg;
rebalance:
/* Allocate without watermarks if the context allows */
if (alloc_flags & ALLOC_NO_WATERMARKS) {
page = __alloc_pages_high_priority(gfp_mask, order,
zonelist, high_zoneidx, nodemask,
preferred_zone, migratetype);
if (page)
goto got_pg;
}
/* Atomic allocations - we can't balance anything */
if (!wait)
goto nopage;
/* Avoid recursion of direct reclaim */
if (p->flags & PF_MEMALLOC)
goto nopage;
/* Avoid allocations with no watermarks from looping endlessly */
if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
goto nopage;
/* Try direct compaction */
page = __alloc_pages_direct_compact(gfp_mask, order,
zonelist, high_zoneidx,
nodemask,
alloc_flags, preferred_zone,
migratetype, &did_some_progress);
if (page)
goto got_pg;
/* Try direct reclaim and then allocating */
page = __alloc_pages_direct_reclaim(gfp_mask, order,
zonelist, high_zoneidx,
nodemask,
alloc_flags, preferred_zone,
migratetype, &did_some_progress);
if (page)
goto got_pg;
/*
* If we failed to make any progress reclaiming, then we are
* running out of options and have to consider going OOM
*/
if (!did_some_progress) {
if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
if (oom_killer_disabled)
goto nopage;
page = __alloc_pages_may_oom(gfp_mask, order,
zonelist, high_zoneidx,
nodemask, preferred_zone,
migratetype);
if (page)
goto got_pg;
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;
}
goto restart;
}
}
/* Check if we should retry the allocation */
pages_reclaimed += did_some_progress;
if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
/* Wait for some write requests to complete then retry */
congestion_wait(BLK_RW_ASYNC, HZ/50);
goto rebalance;
}
nopage:
if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
printk(KERN_WARNING "%s: page allocation failure."
" order:%d, mode:0x%x\n",
p->comm, order, gfp_mask);
dump_stack();
show_mem();
}
return page;
got_pg:
if (kmemcheck_enabled)
kmemcheck_pagealloc_alloc(page, order, gfp_mask);
return page;
}
/*
* 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);
struct zone *preferred_zone;
struct page *page;
int migratetype = allocflags_to_migratetype(gfp_mask);
gfp_mask &= gfp_allowed_mask;
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;
get_mems_allowed();
/* The preferred zone is used for statistics later */
first_zones_zonelist(zonelist, high_zoneidx, nodemask, &preferred_zone);
if (!preferred_zone) {
put_mems_allowed();
return NULL;
}
/* First allocation attempt */
page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET,
preferred_zone, migratetype);
if (unlikely(!page))
page = __alloc_pages_slowpath(gfp_mask, order,
zonelist, high_zoneidx, nodemask,
preferred_zone, migratetype);
put_mems_allowed();
trace_mm_page_alloc(page, order, gfp_mask, migratetype);
return page;
}
EXPORT_SYMBOL(__alloc_pages_nodemask);
/*
* Common helper functions.
*/
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
{
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);
page = alloc_pages(gfp_mask, order);
if (!page)
return 0;
return (unsigned long) page_address(page);
}
EXPORT_SYMBOL(__get_free_pages);
unsigned long get_zeroed_page(gfp_t gfp_mask)
{
return __get_free_pages(gfp_mask | __GFP_ZERO, 0);
}
EXPORT_SYMBOL(get_zeroed_page);
void __pagevec_free(struct pagevec *pvec)
{
int i = pagevec_count(pvec);
while (--i >= 0) {
trace_mm_pagevec_free(pvec->pages[i], pvec->cold);
free_hot_cold_page(pvec->pages[i], pvec->cold);
}
}
void __free_pages(struct page *page, unsigned int order)
{
if (put_page_testzero(page)) {
if (order == 0)
free_hot_cold_page(page, 0);
else
__free_pages_ok(page, order);
}
}
EXPORT_SYMBOL(__free_pages);
void free_pages(unsigned long addr, unsigned int order)
{
if (addr != 0) {
VM_BUG_ON(!virt_addr_valid((void *)addr));
__free_pages(virt_to_page((void *)addr), order);
}
}
EXPORT_SYMBOL(free_pages);
/**
* 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);
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;
}
EXPORT_SYMBOL(alloc_pages_exact);
/**
* 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);
static unsigned int nr_free_zone_pages(int offset)
{
struct zoneref *z;
struct zone *zone;
/* Just pick one node, since fallback list is circular */
unsigned int sum = 0;
struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
for_each_zone_zonelist(zone, z, zonelist, offset) {
unsigned long size = zone->present_pages;
unsigned long high = high_wmark_pages(zone);
if (size > high)
sum += size - high;
}
return sum;
}
/*
* Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
*/
unsigned int nr_free_buffer_pages(void)
{
return nr_free_zone_pages(gfp_zone(GFP_USER));
}
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
/*
* Amount of free RAM allocatable within all zones
*/
unsigned int nr_free_pagecache_pages(void)
{
return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE));
}
static inline void show_node(struct zone *zone)
{
if (NUMA_BUILD)
printk("Node %d ", zone_to_nid(zone));
}
void si_meminfo(struct sysinfo *val)
{
val->totalram = totalram_pages;
val->sharedram = 0;
val->freeram = global_page_state(NR_FREE_PAGES);
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;
val->freeram = node_page_state(nid, NR_FREE_PAGES);
#ifdef CONFIG_HIGHMEM
val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages;
val->freehigh = zone_page_state(&pgdat->node_zones[ZONE_HIGHMEM],
NR_FREE_PAGES);
#else
val->totalhigh = 0;
val->freehigh = 0;
#endif
val->mem_unit = PAGE_SIZE;
}
#endif
#define K(x) ((x) << (PAGE_SHIFT-10))
/*
* Show free area list (used inside shift_scroll-lock stuff)
* We also calculate the percentage fragmentation. We do this by counting the
* memory on each free list with the exception of the first item on the list.
*/
void show_free_areas(void)
{
int cpu;
struct zone *zone;
for_each_populated_zone(zone) {
show_node(zone);
printk("%s per-cpu:\n", zone->name);
for_each_online_cpu(cpu) {
struct per_cpu_pageset *pageset;
pageset = per_cpu_ptr(zone->pageset, cpu);
printk("CPU %4d: hi:%5d, btch:%4d usd:%4d\n",
cpu, pageset->pcp.high,
pageset->pcp.batch, pageset->pcp.count);
}
}
printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
" active_file:%lu inactive_file:%lu isolated_file:%lu\n"
" unevictable:%lu"
" dirty:%lu writeback:%lu unstable:%lu\n"
" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
global_page_state(NR_ACTIVE_ANON),
global_page_state(NR_INACTIVE_ANON),
global_page_state(NR_ISOLATED_ANON),
global_page_state(NR_ACTIVE_FILE),
global_page_state(NR_INACTIVE_FILE),
global_page_state(NR_ISOLATED_FILE),
global_page_state(NR_UNEVICTABLE),
global_page_state(NR_FILE_DIRTY),
global_page_state(NR_WRITEBACK),
global_page_state(NR_UNSTABLE_NFS),
global_page_state(NR_FREE_PAGES),
global_page_state(NR_SLAB_RECLAIMABLE),
global_page_state(NR_SLAB_UNRECLAIMABLE),
global_page_state(NR_FILE_MAPPED),
global_page_state(NR_SHMEM),
global_page_state(NR_PAGETABLE),
global_page_state(NR_BOUNCE));
for_each_populated_zone(zone) {
int i;
show_node(zone);
printk("%s"
" free:%lukB"
" min:%lukB"
" low:%lukB"
" high:%lukB"
" active_anon:%lukB"
" inactive_anon:%lukB"
" active_file:%lukB"
" inactive_file:%lukB"
" unevictable:%lukB"
" isolated(anon):%lukB"
" isolated(file):%lukB"
" present:%lukB"
" mlocked:%lukB"
" dirty:%lukB"
" writeback:%lukB"
" mapped:%lukB"
" shmem:%lukB"
" slab_reclaimable:%lukB"
" slab_unreclaimable:%lukB"
" kernel_stack:%lukB"
" pagetables:%lukB"
" unstable:%lukB"
" bounce:%lukB"
" writeback_tmp:%lukB"
" pages_scanned:%lu"
" all_unreclaimable? %s"
"\n",
zone->name,
K(zone_nr_free_pages(zone)),
K(min_wmark_pages(zone)),
K(low_wmark_pages(zone)),
K(high_wmark_pages(zone)),
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)),
K(zone_page_state(zone, NR_UNEVICTABLE)),
K(zone_page_state(zone, NR_ISOLATED_ANON)),
K(zone_page_state(zone, NR_ISOLATED_FILE)),
K(zone->present_pages),
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)),
K(zone_page_state(zone, NR_SHMEM)),
K(zone_page_state(zone, NR_SLAB_RECLAIMABLE)),
K(zone_page_state(zone, NR_SLAB_UNRECLAIMABLE)),
zone_page_state(zone, NR_KERNEL_STACK) *
THREAD_SIZE / 1024,
K(zone_page_state(zone, NR_PAGETABLE)),
K(zone_page_state(zone, NR_UNSTABLE_NFS)),
K(zone_page_state(zone, NR_BOUNCE)),
K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
zone->pages_scanned,
(zone->all_unreclaimable ? "yes" : "no")
);
printk("lowmem_reserve[]:");
for (i = 0; i < MAX_NR_ZONES; i++)
printk(" %lu", zone->lowmem_reserve[i]);
printk("\n");
}
for_each_populated_zone(zone) {
unsigned long nr[MAX_ORDER], flags, order, total = 0;
show_node(zone);
printk("%s: ", zone->name);
spin_lock_irqsave(&zone->lock, flags);
for (order = 0; order < MAX_ORDER; order++) {
nr[order] = zone->free_area[order].nr_free;
total += nr[order] << order;
}
spin_unlock_irqrestore(&zone->lock, flags);
for (order = 0; order < MAX_ORDER; order++)
printk("%lu*%lukB ", nr[order], K(1UL) << order);
printk("= %lukB\n", K(total));
}
printk("%ld total pagecache pages\n", global_page_state(NR_FILE_PAGES));
show_swap_cache_info();
}
static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
{
zoneref->zone = zone;
zoneref->zone_idx = zone_idx(zone);
}
/*
* Builds allocation fallback zone lists.
*
* Add all populated zones of a node to the zonelist.
*/
static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
int nr_zones, enum zone_type zone_type)
{
struct zone *zone;
BUG_ON(zone_type >= MAX_NR_ZONES);
zone_type++;
do {
zone_type--;
zone = pgdat->node_zones + zone_type;
if (populated_zone(zone)) {
zoneref_set_zone(zone,
&zonelist->_zonerefs[nr_zones++]);
check_highest_zone(zone_type);
}
} while (zone_type);
return nr_zones;
}
/*
* 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"};
#ifdef CONFIG_NUMA
/* The value user specified ....changed by config */
static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
/* string for sysctl */
#define NUMA_ZONELIST_ORDER_LEN 16
char numa_zonelist_order[16] = "default";
/*
* interface for configure zonelist ordering.
* command line option "numa_zonelist_order"
* = "[dD]efault - default, automatic configuration.
* = "[nN]ode - order by node locality, then by zone within node
* = "[zZ]one - order by zone, then by locality within zone
*/
static int __parse_numa_zonelist_order(char *s)
{
if (*s == 'd' || *s == 'D') {
user_zonelist_order = ZONELIST_ORDER_DEFAULT;
} else if (*s == 'n' || *s == 'N') {
user_zonelist_order = ZONELIST_ORDER_NODE;
} else if (*s == 'z' || *s == 'Z') {
user_zonelist_order = ZONELIST_ORDER_ZONE;
} else {
printk(KERN_WARNING
"Ignoring invalid numa_zonelist_order value: "
"%s\n", s);
return -EINVAL;
}
return 0;
}
static __init int setup_numa_zonelist_order(char *s)
{
if (s)
return __parse_numa_zonelist_order(s);
return 0;
}
early_param("numa_zonelist_order", setup_numa_zonelist_order);
/*
* sysctl handler for numa_zonelist_order
*/
int numa_zonelist_order_handler(ctl_table *table, int write,
void __user *buffer, size_t *length,
loff_t *ppos)
{
char saved_string[NUMA_ZONELIST_ORDER_LEN];
int ret;
static DEFINE_MUTEX(zl_order_mutex);
mutex_lock(&zl_order_mutex);
if (write)
strcpy(saved_string, (char*)table->data);
ret = proc_dostring(table, write, buffer, length, ppos);
if (ret)
goto out;
if (write) {
int oldval = user_zonelist_order;
if (__parse_numa_zonelist_order((char*)table->data)) {
/*
* bogus value. restore saved string
*/
strncpy((char*)table->data, saved_string,
NUMA_ZONELIST_ORDER_LEN);
user_zonelist_order = oldval;
} else if (oldval != user_zonelist_order) {
mutex_lock(&zonelists_mutex);
build_all_zonelists(NULL);
mutex_unlock(&zonelists_mutex);
}
}
out:
mutex_unlock(&zl_order_mutex);
return ret;
}
#define MAX_NODE_LOAD (nr_online_nodes)
static int node_load[MAX_NUMNODES];
/**
* find_next_best_node - find the next node that should appear in a given node's fallback list
* @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.
*/
static int find_next_best_node(int node, nodemask_t *used_node_mask)
{
int n, val;
int min_val = INT_MAX;
int best_node = -1;
const struct cpumask *tmp = cpumask_of_node(0);
/* Use the local node if we haven't already */
if (!node_isset(node, *used_node_mask)) {
node_set(node, *used_node_mask);
return node;
}
for_each_node_state(n, N_HIGH_MEMORY) {
/* 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);
/* Penalize nodes under us ("prefer the next node") */
val += (n < node);
/* Give preference to headless and unused nodes */
tmp = cpumask_of_node(n);
if (!cpumask_empty(tmp))
val += PENALTY_FOR_NODE_WITH_CPUS;
/* Slight preference for less loaded node */
val *= (MAX_NODE_LOAD*MAX_NUMNODES);
val += node_load[n];
if (val < min_val) {
min_val = val;
best_node = n;
}
}
if (best_node >= 0)
node_set(best_node, *used_node_mask);
return best_node;
}
/*
* 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)
{
int j;
struct zonelist *zonelist;
zonelist = &pgdat->node_zonelists[0];
for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++)
;
j = build_zonelists_node(NODE_DATA(node), zonelist, j,
MAX_NR_ZONES - 1);
zonelist->_zonerefs[j].zone = NULL;
zonelist->_zonerefs[j].zone_idx = 0;
}
/*
* Build gfp_thisnode zonelists
*/
static void build_thisnode_zonelists(pg_data_t *pgdat)
{
int j;
struct zonelist *zonelist;
zonelist = &pgdat->node_zonelists[1];
j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
zonelist->_zonerefs[j].zone = NULL;
zonelist->_zonerefs[j].zone_idx = 0;
}
/*
* 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;
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)) {
zoneref_set_zone(z,
&zonelist->_zonerefs[pos++]);
check_highest_zone(zone_type);
}
}
}
zonelist->_zonerefs[pos].zone = NULL;
zonelist->_zonerefs[pos].zone_idx = 0;
}
static int default_zonelist_order(void)
{
int nid, zone_type;
unsigned long low_kmem_size,total_size;
struct zone *z;
int average_size;
/*
* ZONE_DMA and ZONE_DMA32 can be very small area in the system.
* If they are really small and used heavily, the system can fall
* into OOM very easily.
* This function detect ZONE_DMA/DMA32 size and configures zone order.
*/
/* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
low_kmem_size = 0;
total_size = 0;
for_each_online_node(nid) {
for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
z = &NODE_DATA(nid)->node_zones[zone_type];
if (populated_zone(z)) {
if (zone_type < ZONE_NORMAL)
low_kmem_size += z->present_pages;
total_size += z->present_pages;
} 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;
}
}
}
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.
*/
average_size = total_size /
(nodes_weight(node_states[N_HIGH_MEMORY]) + 1);
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;
nodemask_t used_mask;
int local_node, prev_node;
struct zonelist *zonelist;
int order = current_zonelist_order;
/* initialize zonelists */
for (i = 0; i < MAX_ZONELISTS; i++) {
zonelist = pgdat->node_zonelists + i;
zonelist->_zonerefs[0].zone = NULL;
zonelist->_zonerefs[0].zone_idx = 0;
}
/* NUMA-aware ordering of nodes */
local_node = pgdat->node_id;
load = nr_online_nodes;
prev_node = local_node;
nodes_clear(used_mask);
memset(node_order, 0, sizeof(node_order));
j = 0;
while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
int distance = node_distance(local_node, node);
/*
* If another node is sufficiently far away then it is better
* to reclaim pages in a zone before going off node.
*/
if (distance > RECLAIM_DISTANCE)
zone_reclaim_mode = 1;
/*
* 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.
*/
if (distance != node_distance(local_node, prev_node))
node_load[node] = load;
prev_node = node;
load--;
if (order == ZONELIST_ORDER_NODE)
build_zonelists_in_node_order(pgdat, node);
else
node_order[j++] = node; /* remember order */
}
if (order == ZONELIST_ORDER_ZONE) {
/* calculate node order -- i.e., DMA last! */
build_zonelists_in_zone_order(pgdat, j);
}
build_thisnode_zonelists(pgdat);
}
/* Construct the zonelist performance cache - see further mmzone.h */
static void build_zonelist_cache(pg_data_t *pgdat)
{
struct zonelist *zonelist;
struct zonelist_cache *zlc;
struct zoneref *z;
zonelist = &pgdat->node_zonelists[0];
zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
for (z = zonelist->_zonerefs; z->zone; z++)
zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z);
}
#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
#else /* CONFIG_NUMA */
static void set_zonelist_order(void)
{
current_zonelist_order = ZONELIST_ORDER_ZONE;
}
static void build_zonelists(pg_data_t *pgdat)
{
int node, local_node;
enum zone_type j;
struct zonelist *zonelist;
local_node = pgdat->node_id;
zonelist = &pgdat->node_zonelists[0];
j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
/*
* 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);
}
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);
}
zonelist->_zonerefs[j].zone = NULL;
zonelist->_zonerefs[j].zone_idx = 0;
}
/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
static void build_zonelist_cache(pg_data_t *pgdat)
{
pgdat->node_zonelists[0].zlcache_ptr = NULL;
}
#endif /* CONFIG_NUMA */
/*
* 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);
static void setup_zone_pageset(struct zone *zone);
/*
* 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);
/* return values int ....just for stop_machine() */
static __init_refok int __build_all_zonelists(void *data)
{
int nid;
int cpu;
#ifdef CONFIG_NUMA
memset(node_load, 0, sizeof(node_load));
#endif
for_each_online_node(nid) {
pg_data_t *pgdat = NODE_DATA(nid);
build_zonelists(pgdat);
build_zonelist_cache(pgdat);
}
#ifdef CONFIG_MEMORY_HOTPLUG
/* Setup real pagesets for the new zone */
if (data) {
struct zone *zone = data;
setup_zone_pageset(zone);
}
#endif
/*
* 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).
*/
for_each_possible_cpu(cpu) {
setup_pageset(&per_cpu(boot_pageset, cpu), 0);
#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
}
return 0;
}
/*
* Called with zonelists_mutex held always
* unless system_state == SYSTEM_BOOTING.
*/
void build_all_zonelists(void *data)
{
set_zonelist_order();
if (system_state == SYSTEM_BOOTING) {
__build_all_zonelists(NULL);
mminit_verify_zonelist();
cpuset_init_current_mems_allowed();
} else {
/* we have to stop all cpus to guarantee there is no user
of zonelist */
stop_machine(__build_all_zonelists, data, NULL);
/* cpuset refresh routine should be here */
}
vm_total_pages = nr_free_pagecache_pages();
/*
* 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
*/
if (vm_total_pages < (pageblock_nr_pages * MIGRATE_TYPES))
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",
nr_online_nodes,
zonelist_order_name[current_zonelist_order],
page_group_by_mobility_disabled ? "off" : "on",
vm_total_pages);
#ifdef CONFIG_NUMA
printk("Policy zone: %s\n", zone_names[policy_zone]);
#endif
}
/*
* 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
#ifndef CONFIG_MEMORY_HOTPLUG
static inline unsigned long wait_table_hash_nr_entries(unsigned long pages)
{
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);
}
#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
/*
* 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))
/*
* Mark a number of pageblocks as MIGRATE_RESERVE. The number
* 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
* higher will lead to a bigger reserve which will get freed as contiguous
* blocks as reclaim kicks in
*/
static void setup_zone_migrate_reserve(struct zone *zone)
{
unsigned long start_pfn, pfn, end_pfn;
struct page *page;
unsigned long block_migratetype;
int reserve;
/* Get the start pfn, end pfn and the number of blocks to reserve */
start_pfn = zone->zone_start_pfn;
end_pfn = start_pfn + zone->spanned_pages;
reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
pageblock_order;
/*
* 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);
for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
if (!pfn_valid(pfn))
continue;
page = pfn_to_page(pfn);
/* Watch out for overlapping nodes */
if (page_to_nid(page) != zone_to_nid(zone))
continue;
/* Blocks with reserved pages will never free, skip them. */
if (PageReserved(page))
continue;
block_migratetype = get_pageblock_migratetype(page);
/* If this block is reserved, account for it */
if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) {
reserve--;
continue;
}
/* Suitable for reserving if this block is movable */
if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) {
set_pageblock_migratetype(page, MIGRATE_RESERVE);
move_freepages_block(zone, page, MIGRATE_RESERVE);
reserve--;
continue;
}
/*
* If the reserve is met and this is a previous reserved block,
* take it back
*/
if (block_migratetype == MIGRATE_RESERVE) {
set_pageblock_migratetype(page, MIGRATE_MOVABLE);
move_freepages_block(zone, page, MIGRATE_MOVABLE);
}
}
}
/*
* 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.
*/
void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
unsigned long start_pfn, enum memmap_context context)
{
struct page *page;
unsigned long end_pfn = start_pfn + size;
unsigned long pfn;
struct zone *z;
if (highest_memmap_pfn < end_pfn - 1)
highest_memmap_pfn = end_pfn - 1;
z = &NODE_DATA(nid)->node_zones[zone];
for (pfn = start_pfn; pfn < end_pfn; pfn++) {
/*
* 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;
}
page = pfn_to_page(pfn);
set_page_links(page, zone, nid, pfn);
mminit_verify_page_links(page, zone, nid, pfn);
init_page_count(page);
reset_page_mapcount(page);
SetPageReserved(page);
/*
* 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
* kernel allocations are made. Later some blocks near
* the start are marked MIGRATE_RESERVE by
* setup_zone_migrate_reserve()
*
* 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.
*/
if ((z->zone_start_pfn <= pfn)
&& (pfn < z->zone_start_pfn + z->spanned_pages)
&& !(pfn & (pageblock_nr_pages - 1)))
set_pageblock_migratetype(page, MIGRATE_MOVABLE);
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))
set_page_address(page, __va(pfn << PAGE_SHIFT));
#endif
}
}
static void __meminit zone_init_free_lists(struct zone *zone)
{
int order, t;
for_each_migratetype_order(order, t) {
INIT_LIST_HEAD(&zone->free_area[order].free_list[t]);
zone->free_area[order].nr_free = 0;
}
}
#ifndef __HAVE_ARCH_MEMMAP_INIT
#define memmap_init(size, nid, zone, start_pfn) \
memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
#endif
static int zone_batchsize(struct zone *zone)
{
#ifdef CONFIG_MMU
int batch;
/*
* The per-cpu-pages pools are set to around 1000th of the
* size of the zone. But no more than 1/2 of a meg.
*
* OK, so we don't know how big the cache is. So guess.
*/
batch = zone->present_pages / 1024;
if (batch * PAGE_SIZE > 512 * 1024)
batch = (512 * 1024) / PAGE_SIZE;
batch /= 4; /* We effectively *= 4 below */
if (batch < 1)
batch = 1;
/*
* 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.
*
* 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.
*/
batch = rounddown_pow_of_two(batch + batch/2) - 1;
return batch;
#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
}
static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
{
struct per_cpu_pages *pcp;
int migratetype;
memset(p, 0, sizeof(*p));
pcp = &p->pcp;
pcp->count = 0;
pcp->high = 6 * batch;
pcp->batch = max(1UL, 1 * batch);
for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++)
INIT_LIST_HEAD(&pcp->lists[migratetype]);
}
/*
* setup_pagelist_highmark() sets the high water mark for hot per_cpu_pagelist
* to the value high for the pageset p.
*/
static void setup_pagelist_highmark(struct per_cpu_pageset *p,
unsigned long high)
{
struct per_cpu_pages *pcp;
pcp = &p->pcp;
pcp->high = high;
pcp->batch = max(1UL, high/4);
if ((high/4) > (PAGE_SHIFT * 8))
pcp->batch = PAGE_SHIFT * 8;
}
static __meminit void setup_zone_pageset(struct zone *zone)
{
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));
}
}
/*
* Allocate per cpu pagesets and initialize them.
* Before this call only boot pagesets were available.
*/
void __init setup_per_cpu_pageset(void)
{
struct zone *zone;
for_each_populated_zone(zone)
setup_zone_pageset(zone);
}
static noinline __init_refok
int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages)
{
int i;
struct pglist_data *pgdat = zone->zone_pgdat;
size_t alloc_size;
/*
* The per-page waitqueue mechanism uses hashed waitqueues
* per zone.
*/
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);
alloc_size = zone->wait_table_hash_nr_entries
* sizeof(wait_queue_head_t);
if (!slab_is_available()) {
zone->wait_table = (wait_queue_head_t *)
alloc_bootmem_node(pgdat, alloc_size);
} else {
/*
* This case means that a zone whose size was 0 gets new memory
* via memory hot-add.
* But it may be the case that a new node was hot-added. In
* this case vmalloc() will not be able to use this new node's
* memory - this wait_table must be initialized to use this new
* node itself as well.
* To use this new node's memory, further consideration will be
* necessary.
*/
zone->wait_table = vmalloc(alloc_size);
}
if (!zone->wait_table)
return -ENOMEM;
for(i = 0; i < zone->wait_table_hash_nr_entries; ++i)
init_waitqueue_head(zone->wait_table + i);
return 0;
}
static int __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);
free_pcppages_bulk(zone, pcp->count, pcp);
setup_pageset(pset, batch);
local_irq_restore(flags);
}
return 0;
}
void zone_pcp_update(struct zone *zone)
{
stop_machine(__zone_pcp_update, zone, NULL);
}
static __meminit void zone_pcp_init(struct zone *zone)
{
/*
* 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;
if (zone->present_pages)
printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n",
zone->name, zone->present_pages,
zone_batchsize(zone));
}
__meminit int init_currently_empty_zone(struct zone *zone,
unsigned long zone_start_pfn,
unsigned long size,
enum memmap_context context)
{
struct pglist_data *pgdat = zone->zone_pgdat;
int ret;
ret = zone_wait_table_init(zone, size);
if (ret)
return ret;
pgdat->nr_zones = zone_idx(zone) + 1;
zone->zone_start_pfn = zone_start_pfn;
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));
zone_init_free_lists(zone);
return 0;
}
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
/*
* Basic iterator support. Return the first range of PFNs for a node
* Note: nid == MAX_NUMNODES returns first region regardless of node
*/
static int __meminit first_active_region_index_in_nid(int nid)
{
int i;
for (i = 0; i < nr_nodemap_entries; i++)
if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
return i;
return -1;
}
/*
* Basic iterator support. Return the next active range of PFNs for a node
* Note: nid == MAX_NUMNODES returns next region regardless of node
*/
static int __meminit next_active_region_index_in_nid(int index, int nid)
{
for (index = index + 1; index < nr_nodemap_entries; index++)
if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
return index;
return -1;
}
#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
/*
* Required by SPARSEMEM. Given a PFN, return what node the PFN is on.
* Architectures may implement their own version but if add_active_range()
* was used and there are no special requirements, this is a convenient
* alternative
*/
int __meminit __early_pfn_to_nid(unsigned long pfn)
{
int i;
for (i = 0; i < nr_nodemap_entries; i++) {
unsigned long start_pfn = early_node_map[i].start_pfn;
unsigned long end_pfn = early_node_map[i].end_pfn;
if (start_pfn <= pfn && pfn < end_pfn)
return early_node_map[i].nid;
}
/* This is a memory hole */
return -1;
}
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
int __meminit early_pfn_to_nid(unsigned long pfn)
{
int nid;
nid = __early_pfn_to_nid(pfn);
if (nid >= 0)
return nid;
/* just returns 0 */
return 0;
}
#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
/* Basic iterator support to walk early_node_map[] */
#define for_each_active_range_index_in_nid(i, nid) \
for (i = first_active_region_index_in_nid(nid); i != -1; \
i = next_active_region_index_in_nid(i, nid))
/**
* free_bootmem_with_active_regions - Call free_bootmem_node for each active range
* @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
*
* If an architecture guarantees that all ranges registered with
* add_active_ranges() contain no holes and may be freed, this
* this function may be used instead of calling free_bootmem() manually.
*/
void __init free_bootmem_with_active_regions(int nid,
unsigned long max_low_pfn)
{
int i;
for_each_active_range_index_in_nid(i, nid) {
unsigned long size_pages = 0;
unsigned long end_pfn = early_node_map[i].end_pfn;
if (early_node_map[i].start_pfn >= max_low_pfn)
continue;
if (end_pfn > max_low_pfn)
end_pfn = max_low_pfn;
size_pages = end_pfn - early_node_map[i].start_pfn;
free_bootmem_node(NODE_DATA(early_node_map[i].nid),
PFN_PHYS(early_node_map[i].start_pfn),
size_pages << PAGE_SHIFT);
}
}
int __init add_from_early_node_map(struct range *range, int az,
int nr_range, int nid)
{
int i;
u64 start, end;
/* need to go over early_node_map to find out good range for node */
for_each_active_range_index_in_nid(i, nid) {
start = early_node_map[i].start_pfn;
end = early_node_map[i].end_pfn;
nr_range = add_range(range, az, nr_range, start, end);
}
return nr_range;
}
#ifdef CONFIG_NO_BOOTMEM
void * __init __alloc_memory_core_early(int nid, u64 size, u64 align,
u64 goal, u64 limit)
{
int i;
void *ptr;
if (limit > get_max_mapped())
limit = get_max_mapped();
/* need to go over early_node_map to find out good range for node */
for_each_active_range_index_in_nid(i, nid) {
u64 addr;
u64 ei_start, ei_last;
ei_last = early_node_map[i].end_pfn;
ei_last <<= PAGE_SHIFT;
ei_start = early_node_map[i].start_pfn;
ei_start <<= PAGE_SHIFT;
addr = find_early_area(ei_start, ei_last,
goal, limit, size, align);
if (addr == -1ULL)
continue;
#if 0
printk(KERN_DEBUG "alloc (nid=%d %llx - %llx) (%llx - %llx) %llx %llx => %llx\n",
nid,
ei_start, ei_last, goal, limit, size,
align, addr);
#endif
ptr = phys_to_virt(addr);
memset(ptr, 0, size);
reserve_early_without_check(addr, addr + size, "BOOTMEM");
/*
* The min_count is set to 0 so that bootmem allocated blocks
* are never reported as leaks.
*/
kmemleak_alloc(ptr, size, 0, 0);
return ptr;
}
return NULL;
}
#endif
void __init work_with_active_regions(int nid, work_fn_t work_fn, void *data)
{
int i;
int ret;
for_each_active_range_index_in_nid(i, nid) {
ret = work_fn(early_node_map[i].start_pfn,
early_node_map[i].end_pfn, data);
if (ret)
break;
}
}
/**
* sparse_memory_present_with_active_regions - Call memory_present for each active range
* @nid: The node to call memory_present for. If MAX_NUMNODES, all nodes will be used.
*
* If an architecture guarantees that all ranges registered with
* add_active_ranges() contain no holes and may be freed, this
* function may be used instead of calling memory_present() manually.
*/
void __init sparse_memory_present_with_active_regions(int nid)
{
int i;
for_each_active_range_index_in_nid(i, nid)
memory_present(early_node_map[i].nid,
early_node_map[i].start_pfn,
early_node_map[i].end_pfn);
}
/**
* get_pfn_range_for_nid - Return the start and end page frames for a node
* @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.
*
* 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
* PFNs will be 0.
*/
void __meminit get_pfn_range_for_nid(unsigned int nid,
unsigned long *start_pfn, unsigned long *end_pfn)
{
int i;
*start_pfn = -1UL;
*end_pfn = 0;
for_each_active_range_index_in_nid(i, nid) {
*start_pfn = min(*start_pfn, early_node_map[i].start_pfn);
*end_pfn = max(*end_pfn, early_node_map[i].end_pfn);
}
if (*start_pfn == -1UL)
*start_pfn = 0;
}
/*
* 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
*/
static void __init find_usable_zone_for_movable(void)
{
int zone_index;
for (zone_index = MAX_NR_ZONES - 1; zone_index >= 0; zone_index--) {
if (zone_index == ZONE_MOVABLE)
continue;
if (arch_zone_highest_possible_pfn[zone_index] >
arch_zone_lowest_possible_pfn[zone_index])
break;
}
VM_BUG_ON(zone_index == -1);
movable_zone = zone_index;
}
/*
* The zone ranges provided by the architecture do not include ZONE_MOVABLE
* because it is sized independant of architecture. Unlike the other zones,
* the starting point for ZONE_MOVABLE is not fixed. It may be different
* in each node depending on the size of each node and how evenly kernelcore
* is distributed. This helper function adjusts the zone ranges
* provided by the architecture for a given node by using the end of the
* highest usable zone for ZONE_MOVABLE. This preserves the assumption that
* zones within a node are in order of monotonic increases memory addresses
*/
static void __meminit adjust_zone_range_for_zone_movable(int nid,
unsigned long zone_type,
unsigned long node_start_pfn,
unsigned long node_end_pfn,
unsigned long *zone_start_pfn,
unsigned long *zone_end_pfn)
{
/* Only adjust if ZONE_MOVABLE is on this node */
if (zone_movable_pfn[nid]) {
/* Size ZONE_MOVABLE */
if (zone_type == ZONE_MOVABLE) {
*zone_start_pfn = zone_movable_pfn[nid];
*zone_end_pfn = min(node_end_pfn,
arch_zone_highest_possible_pfn[movable_zone]);
/* Adjust for ZONE_MOVABLE starting within this range */
} else if (*zone_start_pfn < zone_movable_pfn[nid] &&
*zone_end_pfn > zone_movable_pfn[nid]) {
*zone_end_pfn = zone_movable_pfn[nid];
/* Check if this whole range is within ZONE_MOVABLE */
} else if (*zone_start_pfn >= zone_movable_pfn[nid])
*zone_start_pfn = *zone_end_pfn;
}
}
/*
* 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()
*/
static unsigned long __meminit zone_spanned_pages_in_node(int nid,
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];
adjust_zone_range_for_zone_movable(nid, zone_type,
node_start_pfn, node_end_pfn,
&zone_start_pfn, &zone_end_pfn);
/* 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,
* then all holes in the requested range will be accounted for.
*/
unsigned long __meminit __absent_pages_in_range(int nid,
unsigned long range_start_pfn,
unsigned long range_end_pfn)
{
int i = 0;
unsigned long prev_end_pfn = 0, hole_pages = 0;
unsigned long start_pfn;
/* Find the end_pfn of the first active range of pfns in the node */
i = first_active_region_index_in_nid(nid);
if (i == -1)
return 0;
prev_end_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
/* Account for ranges before physical memory on this node */
if (early_node_map[i].start_pfn > range_start_pfn)
hole_pages = prev_end_pfn - range_start_pfn;
/* Find all holes for the zone within the node */
for (; i != -1; i = next_active_region_index_in_nid(i, nid)) {
/* No need to continue if prev_end_pfn is outside the zone */
if (prev_end_pfn >= range_end_pfn)
break;
/* Make sure the end of the zone is not within the hole */
start_pfn = min(early_node_map[i].start_pfn, range_end_pfn);
prev_end_pfn = max(prev_end_pfn, range_start_pfn);
/* Update the hole size cound and move on */
if (start_pfn > range_start_pfn) {
BUG_ON(prev_end_pfn > start_pfn);
hole_pages += start_pfn - prev_end_pfn;
}
prev_end_pfn = early_node_map[i].end_pfn;
}
/* Account for ranges past physical memory on this node */
if (range_end_pfn > prev_end_pfn)
hole_pages += range_end_pfn -
max(range_start_pfn, prev_end_pfn);
return hole_pages;
}
/**
* absent_pages_in_range - Return number of page frames in holes within a range
* @start_pfn: The start PFN to start searching for holes
* @end_pfn: The end PFN to stop searching for holes
*
* It returns the number of pages frames in memory holes within a range.
*/
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 */
static unsigned long __meminit zone_absent_pages_in_node(int nid,
unsigned long zone_type,
unsigned long *ignored)
{
unsigned long node_start_pfn, node_end_pfn;
unsigned long zone_start_pfn, zone_end_pfn;
get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
zone_start_pfn = max(arch_zone_lowest_possible_pfn[zone_type],
node_start_pfn);
zone_end_pfn = min(arch_zone_highest_possible_pfn[zone_type],
node_end_pfn);
adjust_zone_range_for_zone_movable(nid, zone_type,
node_start_pfn, node_end_pfn,
&zone_start_pfn, &zone_end_pfn);
return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
}
#else
static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
unsigned long zone_type,
unsigned long *zones_size)
{
return zones_size[zone_type];
}
static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
unsigned long zone_type,
unsigned long *zholes_size)
{
if (!zholes_size)
return 0;
return zholes_size[zone_type];
}
#endif
static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
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);
}
#ifndef CONFIG_SPARSEMEM
/*
* Calculate the size of the zone->blockflags rounded to an unsigned long
* 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
* 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;
usemapsize = roundup(zonesize, pageblock_nr_pages);
usemapsize = usemapsize >> pageblock_order;
usemapsize *= NR_PAGEBLOCK_BITS;
usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
return usemapsize / 8;
}
static void __init setup_usemap(struct pglist_data *pgdat,
struct zone *zone, unsigned long zonesize)
{
unsigned long usemapsize = usemap_size(zonesize);
zone->pageblock_flags = NULL;
if (usemapsize)
zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize);
}
#else
static void inline setup_usemap(struct pglist_data *pgdat,
struct zone *zone, unsigned long zonesize) {}
#endif /* CONFIG_SPARSEMEM */
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
/* Return a sensible default order for the pageblock size. */
static inline int pageblock_default_order(void)
{
if (HPAGE_SHIFT > PAGE_SHIFT)
return HUGETLB_PAGE_ORDER;
return MAX_ORDER-1;
}
/* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */
static inline void __init set_pageblock_order(unsigned int order)
{
/* Check that pageblock_nr_pages has not already been setup */
if (pageblock_order)
return;
/*
* Assume the largest contiguous order of interest is a huge page.
* This value may be variable depending on boot parameters on IA64
*/
pageblock_order = order;
}
#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
/*
* When CONFIG_HUGETLB_PAGE_SIZE_VARIABLE is not set, set_pageblock_order()
* and pageblock_default_order() are unused as pageblock_order is set
* at compile-time. See include/linux/pageblock-flags.h for the values of
* pageblock_order based on the kernel config
*/
static inline int pageblock_default_order(unsigned int order)
{
return MAX_ORDER-1;
}
#define set_pageblock_order(x) do {} while (0)
#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
/*
* Set up the zone data structures:
* - mark all pages reserved
* - mark all memory queues empty
* - clear the memory bitmaps
*/
static void __paginginit free_area_init_core(struct pglist_data *pgdat,
unsigned long *zones_size, unsigned long *zholes_size)
{
enum zone_type j;
int nid = pgdat->node_id;
unsigned long zone_start_pfn = pgdat->node_start_pfn;
int ret;
pgdat_resize_init(pgdat);
pgdat->nr_zones = 0;
init_waitqueue_head(&pgdat->kswapd_wait);
pgdat->kswapd_max_order = 0;
pgdat_page_cgroup_init(pgdat);
for (j = 0; j < MAX_NR_ZONES; j++) {
struct zone *zone = pgdat->node_zones + j;
unsigned long size, realsize, memmap_pages;
enum lru_list l;
size = zone_spanned_pages_in_node(nid, j, zones_size);
realsize = size - zone_absent_pages_in_node(nid, j,
zholes_size);
/*
* Adjust realsize so that it accounts for how much memory
* is used by this zone for memmap. This affects the watermark
* and per-cpu initialisations
*/
memmap_pages =
PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
if (realsize >= memmap_pages) {
realsize -= memmap_pages;
if (memmap_pages)
printk(KERN_DEBUG
" %s zone: %lu pages used for memmap\n",
zone_names[j], memmap_pages);
} else
printk(KERN_WARNING
" %s zone: %lu pages exceeds realsize %lu\n",
zone_names[j], memmap_pages, realsize);
/* Account for reserved pages */
if (j == 0 && realsize > dma_reserve) {
realsize -= dma_reserve;
printk(KERN_DEBUG " %s zone: %lu pages reserved\n",
zone_names[0], dma_reserve);
}
if (!is_highmem_idx(j))
nr_kernel_pages += realsize;
nr_all_pages += realsize;
zone->spanned_pages = size;
zone->present_pages = realsize;
#ifdef CONFIG_NUMA
zone->node = nid;
zone->min_unmapped_pages = (realsize*sysctl_min_unmapped_ratio)
/ 100;
zone->min_slab_pages = (realsize * sysctl_min_slab_ratio) / 100;
#endif
zone->name = zone_names[j];
spin_lock_init(&zone->lock);
spin_lock_init(&zone->lru_lock);
zone_seqlock_init(zone);
zone->zone_pgdat = pgdat;
zone_pcp_init(zone);
for_each_lru(l) {
INIT_LIST_HEAD(&zone->lru[l].list);
zone->reclaim_stat.nr_saved_scan[l] = 0;
}
zone->reclaim_stat.recent_rotated[0] = 0;
zone->reclaim_stat.recent_rotated[1] = 0;
zone->reclaim_stat.recent_scanned[0] = 0;
zone->reclaim_stat.recent_scanned[1] = 0;
zap_zone_vm_stats(zone);
zone->flags = 0;
if (!size)
continue;
set_pageblock_order(pageblock_default_order());
setup_usemap(pgdat, zone, size);
ret = init_currently_empty_zone(zone, zone_start_pfn,
size, MEMMAP_EARLY);
BUG_ON(ret);
memmap_init(size, nid, j, zone_start_pfn);
zone_start_pfn += size;
}
}
static void __init_refok alloc_node_mem_map(struct pglist_data *pgdat)
{
/* Skip empty nodes */
if (!pgdat->node_spanned_pages)
return;
#ifdef CONFIG_FLAT_NODE_MEM_MAP
/* ia64 gets its own node_mem_map, before this, without bootmem */
if (!pgdat->node_mem_map) {
unsigned long size, start, end;
struct page *map;
/*
* 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);
map = alloc_remap(pgdat->node_id, size);
if (!map)
map = alloc_bootmem_node(pgdat, size);
pgdat->node_mem_map = map + (pgdat->node_start_pfn - start);
}
#ifndef CONFIG_NEED_MULTIPLE_NODES
/*
* With no DISCONTIG, the global mem_map is just set as node 0's
*/
if (pgdat == NODE_DATA(0)) {
mem_map = NODE_DATA(0)->node_mem_map;
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
mem_map -= (pgdat->node_start_pfn - ARCH_PFN_OFFSET);
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
}
#endif
#endif /* CONFIG_FLAT_NODE_MEM_MAP */
}
void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
unsigned long node_start_pfn, unsigned long *zholes_size)
{
pg_data_t *pgdat = NODE_DATA(nid);
pgdat->node_id = nid;
pgdat->node_start_pfn = node_start_pfn;
calculate_node_totalpages(pgdat, zones_size, zholes_size);
alloc_node_mem_map(pgdat);
#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
free_area_init_core(pgdat, zones_size, zholes_size);
}
#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
#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
/**
* add_active_range - Register a range of PFNs backed by physical memory
* @nid: The node ID the range resides on
* @start_pfn: The start PFN of the available physical memory
* @end_pfn: The end PFN of the available physical memory
*
* These ranges are stored in an early_node_map[] and later used by
* free_area_init_nodes() to calculate zone sizes and holes. If the
* range spans a memory hole, it is up to the architecture to ensure
* the memory is not freed by the bootmem allocator. If possible
* the range being registered will be merged with existing ranges.
*/
void __init add_active_range(unsigned int nid, unsigned long start_pfn,
unsigned long end_pfn)
{
int i;
mminit_dprintk(MMINIT_TRACE, "memory_register",
"Entering add_active_range(%d, %#lx, %#lx) "
"%d entries of %d used\n",
nid, start_pfn, end_pfn,
nr_nodemap_entries, MAX_ACTIVE_REGIONS);
mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
/* Merge with existing active regions if possible */
for (i = 0; i < nr_nodemap_entries; i++) {
if (early_node_map[i].nid != nid)
continue;
/* Skip if an existing region covers this new one */
if (start_pfn >= early_node_map[i].start_pfn &&
end_pfn <= early_node_map[i].end_pfn)
return;
/* Merge forward if suitable */
if (start_pfn <= early_node_map[i].end_pfn &&
end_pfn > early_node_map[i].end_pfn) {
early_node_map[i].end_pfn = end_pfn;
return;
}
/* Merge backward if suitable */
if (start_pfn < early_node_map[i].start_pfn &&
end_pfn >= early_node_map[i].start_pfn) {
early_node_map[i].start_pfn = start_pfn;
return;
}
}
/* Check that early_node_map is large enough */
if (i >= MAX_ACTIVE_REGIONS) {
printk(KERN_CRIT "More than %d memory regions, truncating\n",
MAX_ACTIVE_REGIONS);
return;
}
early_node_map[i].nid = nid;
early_node_map[i].start_pfn = start_pfn;
early_node_map[i].end_pfn = end_pfn;
nr_nodemap_entries = i + 1;
}
/**
* remove_active_range - Shrink an existing registered range of PFNs
* @nid: The node id the range is on that should be shrunk
* @start_pfn: The new PFN of the range
* @end_pfn: The new PFN of the range
*
* i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
* The map is kept near the end physical page range that has already been
* registered. This function allows an arch to shrink an existing registered
* range.
*/
void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
unsigned long end_pfn)
{
int i, j;
int removed = 0;
printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
nid, start_pfn, end_pfn);
/* Find the old active region end and shrink */
for_each_active_range_index_in_nid(i, nid) {
if (early_node_map[i].start_pfn >= start_pfn &&
early_node_map[i].end_pfn <= end_pfn) {
/* clear it */
early_node_map[i].start_pfn = 0;
early_node_map[i].end_pfn = 0;
removed = 1;
continue;
}
if (early_node_map[i].start_pfn < start_pfn &&
early_node_map[i].end_pfn > start_pfn) {
unsigned long temp_end_pfn = early_node_map[i].end_pfn;
early_node_map[i].end_pfn = start_pfn;
if (temp_end_pfn > end_pfn)
add_active_range(nid, end_pfn, temp_end_pfn);
continue;
}
if (early_node_map[i].start_pfn >= start_pfn &&
early_node_map[i].end_pfn > end_pfn &&
early_node_map[i].start_pfn < end_pfn) {
early_node_map[i].start_pfn = end_pfn;
continue;
}
}
if (!removed)
return;
/* remove the blank ones */
for (i = nr_nodemap_entries - 1; i > 0; i--) {
if (early_node_map[i].nid != nid)
continue;
if (early_node_map[i].end_pfn)
continue;
/* we found it, get rid of it */
for (j = i; j < nr_nodemap_entries - 1; j++)
memcpy(&early_node_map[j], &early_node_map[j+1],
sizeof(early_node_map[j]));
j = nr_nodemap_entries - 1;
memset(&early_node_map[j], 0, sizeof(early_node_map[j]));
nr_nodemap_entries--;
}
}
/**
* remove_all_active_ranges - Remove all currently registered regions
*
* During discovery, it may be found that a table like SRAT is invalid
* and an alternative discovery method must be used. This function removes
* all currently registered regions.
*/
void __init remove_all_active_ranges(void)
{
memset(early_node_map, 0, sizeof(early_node_map));
nr_nodemap_entries = 0;
}
/* Compare two active node_active_regions */
static int __init cmp_node_active_region(const void *a, const void *b)
{
struct node_active_region *arange = (struct node_active_region *)a;
struct node_active_region *brange = (struct node_active_region *)b;
/* Done this way to avoid overflows */
if (arange->start_pfn > brange->start_pfn)
return 1;
if (arange->start_pfn < brange->start_pfn)
return -1;
return 0;
}
/* sort the node_map by start_pfn */
void __init sort_node_map(void)
{
sort(early_node_map, (size_t)nr_nodemap_entries,
sizeof(struct node_active_region),
cmp_node_active_region, NULL);
}
/* Find the lowest pfn for a node */
static unsigned long __init find_min_pfn_for_node(int nid)
{
int i;
unsigned long min_pfn = ULONG_MAX;
/* Assuming a sorted map, the first range found has the starting pfn */
for_each_active_range_index_in_nid(i, nid)
min_pfn = min(min_pfn, early_node_map[i].start_pfn);
if (min_pfn == ULONG_MAX) {
printk(KERN_WARNING
"Could not find start_pfn for node %d\n", nid);
return 0;
}
return min_pfn;
}
/**
* find_min_pfn_with_active_regions - Find the minimum PFN registered
*
* It returns the minimum PFN based on information provided via
* add_active_range().
*/
unsigned long __init find_min_pfn_with_active_regions(void)
{
return find_min_pfn_for_node(MAX_NUMNODES);
}
/*
* early_calculate_totalpages()
* Sum pages in active regions for movable zone.
* Populate N_HIGH_MEMORY for calculating usable_nodes.
*/
static unsigned long __init early_calculate_totalpages(void)
{
int i;
unsigned long totalpages = 0;
for (i = 0; i < nr_nodemap_entries; i++) {
unsigned long pages = early_node_map[i].end_pfn -
early_node_map[i].start_pfn;
totalpages += pages;
if (pages)
node_set_state(early_node_map[i].nid, N_HIGH_MEMORY);
}
return totalpages;
}
/*
* 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
*/
static void __init find_zone_movable_pfns_for_nodes(unsigned long *movable_pfn)
{
int i, nid;
unsigned long usable_startpfn;
unsigned long kernelcore_node, kernelcore_remaining;
/* save the state before borrow the nodemask */
nodemask_t saved_node_state = node_states[N_HIGH_MEMORY];
unsigned long totalpages = early_calculate_totalpages();
int usable_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
/*
* 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);
}
/* If kernelcore was not specified, there is no ZONE_MOVABLE */
if (!required_kernelcore)
goto out;
/* 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;
for_each_node_state(nid, N_HIGH_MEMORY) {
/*
* Recalculate kernelcore_node if the division per node
* now exceeds what is necessary to satisfy the requested
* amount of memory for the kernel
*/
if (required_kernelcore < kernelcore_node)
kernelcore_node = required_kernelcore / usable_nodes;
/*
* As the map is walked, we track how much memory is usable
* by the kernel using kernelcore_remaining. When it is
* 0, the rest of the node is usable by ZONE_MOVABLE
*/
kernelcore_remaining = kernelcore_node;
/* Go through each range of PFNs within this node */
for_each_active_range_index_in_nid(i, nid) {
unsigned long start_pfn, end_pfn;
unsigned long size_pages;
start_pfn = max(early_node_map[i].start_pfn,
zone_movable_pfn[nid]);
end_pfn = early_node_map[i].end_pfn;
if (start_pfn >= end_pfn)
continue;
/* Account for what is only usable for kernelcore */
if (start_pfn < usable_startpfn) {
unsigned long kernel_pages;
kernel_pages = min(end_pfn, usable_startpfn)
- start_pfn;
kernelcore_remaining -= min(kernel_pages,
kernelcore_remaining);
required_kernelcore -= min(kernel_pages,
required_kernelcore);
/* Continue if range is now fully accounted */
if (end_pfn <= usable_startpfn) {
/*
* Push zone_movable_pfn to the end so
* that if we have to rebalance
* kernelcore across nodes, we will
* not double account here
*/
zone_movable_pfn[nid] = end_pfn;
continue;
}
start_pfn = usable_startpfn;
}
/*
* The usable PFN range for ZONE_MOVABLE is from
* start_pfn->end_pfn. Calculate size_pages as the
* number of pages used as kernelcore
*/
size_pages = end_pfn - start_pfn;
if (size_pages > kernelcore_remaining)
size_pages = kernelcore_remaining;
zone_movable_pfn[nid] = start_pfn + size_pages;
/*
* Some kernelcore has been met, update counts and
* break if the kernelcore for this node has been
* satisified
*/
required_kernelcore -= min(required_kernelcore,
size_pages);
kernelcore_remaining -= size_pages;
if (!kernelcore_remaining)
break;
}
}
/*
* If there is still required_kernelcore, we do another pass with one
* less node in the count. This will push zone_movable_pfn[nid] further
* along on the nodes that still have memory until kernelcore is
* satisified
*/
usable_nodes--;
if (usable_nodes && required_kernelcore > usable_nodes)
goto restart;
/* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
for (nid = 0; nid < MAX_NUMNODES; nid++)
zone_movable_pfn[nid] =
roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES);
out:
/* restore the node_state */
node_states[N_HIGH_MEMORY] = saved_node_state;
}
/* Any regular memory on that node ? */
static void check_for_regular_memory(pg_data_t *pgdat)
{
#ifdef CONFIG_HIGHMEM
enum zone_type zone_type;
for (zone_type = 0; zone_type <= ZONE_NORMAL; zone_type++) {
struct zone *zone = &pgdat->node_zones[zone_type];
if (zone->present_pages)
node_set_state(zone_to_nid(zone), N_NORMAL_MEMORY);
}
#endif
}
/**
* free_area_init_nodes - Initialise all pg_data_t and zone data
* @max_zone_pfn: an array of max PFNs for each zone
*
* This will call free_area_init_node() for each active node in the system.
* Using the page ranges provided by add_active_range(), the size of each
* zone in each node and their holes is calculated. If the maximum PFN
* between two adjacent zones match, it is assumed that the zone is empty.
* For example, if arch_max_dma_pfn == arch_max_dma32_pfn, it is assumed
* that arch_max_dma32_pfn has no pages. It is also assumed that a zone
* starts where the previous one ended. For example, ZONE_DMA32 starts
* at arch_max_dma_pfn.
*/
void __init free_area_init_nodes(unsigned long *max_zone_pfn)
{
unsigned long nid;
int i;
/* Sort early_node_map as initialisation assumes it is sorted */
sort_node_map();
/* 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++) {
if (i == ZONE_MOVABLE)
continue;
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]);
}
arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
/* Find the PFNs that ZONE_MOVABLE begins at in each node */
memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
find_zone_movable_pfns_for_nodes(zone_movable_pfn);
/* Print out the zone ranges */
printk("Zone PFN ranges:\n");
for (i = 0; i < MAX_NR_ZONES; i++) {
if (i == ZONE_MOVABLE)
continue;
printk(" %-8s ", zone_names[i]);
if (arch_zone_lowest_possible_pfn[i] ==
arch_zone_highest_possible_pfn[i])
printk("empty\n");
else
printk("%0#10lx -> %0#10lx\n",
arch_zone_lowest_possible_pfn[i],
arch_zone_highest_possible_pfn[i]);
}
/* Print out the PFNs ZONE_MOVABLE begins at in each node */
printk("Movable zone start PFN for each node\n");
for (i = 0; i < MAX_NUMNODES; i++) {
if (zone_movable_pfn[i])
printk(" Node %d: %lu\n", i, zone_movable_pfn[i]);
}
/* Print out the early_node_map[] */
printk("early_node_map[%d] active PFN ranges\n", nr_nodemap_entries);
for (i = 0; i < nr_nodemap_entries; i++)
printk(" %3d: %0#10lx -> %0#10lx\n", early_node_map[i].nid,
early_node_map[i].start_pfn,
early_node_map[i].end_pfn);
/* Initialise every node */
mminit_verify_pageflags_layout();
setup_nr_node_ids();
for_each_online_node(nid) {
pg_data_t *pgdat = NODE_DATA(nid);
free_area_init_node(nid, NULL,
find_min_pfn_for_node(nid), NULL);
/* Any memory on that node */
if (pgdat->node_present_pages)
node_set_state(nid, N_HIGH_MEMORY);
check_for_regular_memory(pgdat);
}
}
static int __init cmdline_parse_core(char *p, unsigned long *core)
{
unsigned long long coremem;
if (!p)
return -EINVAL;
coremem = memparse(p, &p);
*core = coremem >> PAGE_SHIFT;
/* Paranoid check that UL is enough for the coremem value */
WARN_ON((coremem >> PAGE_SHIFT) > ULONG_MAX);
return 0;
}
/*
* 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);
}
early_param("kernelcore", cmdline_parse_kernelcore);
early_param("movablecore", cmdline_parse_movablecore);
#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
/**
* set_dma_reserve - set the specified number of pages reserved in the first zone
* @new_dma_reserve: The number of pages to mark reserved
*
* 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
* 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.
*/
void __init set_dma_reserve(unsigned long new_dma_reserve)
{
dma_reserve = new_dma_reserve;
}
#ifndef CONFIG_NEED_MULTIPLE_NODES
struct pglist_data __refdata contig_page_data = {
#ifndef CONFIG_NO_BOOTMEM
.bdata = &bootmem_node_data[0]
#endif
};
EXPORT_SYMBOL(contig_page_data);
#endif
void __init free_area_init(unsigned long *zones_size)
{
free_area_init_node(0, zones_size,
__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;
if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
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.
*/
vm_events_fold_cpu(cpu);
/*
* 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.
*/
refresh_cpu_vm_stats(cpu);
}
return NOTIFY_OK;
}
void __init page_alloc_init(void)
{
hotcpu_notifier(page_alloc_cpu_notify, 0);
}
/*
* 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;
enum zone_type i, j;
for_each_online_pgdat(pgdat) {
for (i = 0; i < MAX_NR_ZONES; i++) {
struct zone *zone = pgdat->node_zones + i;
unsigned long max = 0;
/* Find valid and maximum lowmem_reserve in the zone */
for (j = i; j < MAX_NR_ZONES; j++) {
if (zone->lowmem_reserve[j] > max)
max = zone->lowmem_reserve[j];
}
/* we treat the high watermark as reserved pages. */
max += high_wmark_pages(zone);
if (max > zone->present_pages)
max = zone->present_pages;
reserve_pages += max;
}
}
totalreserve_pages = reserve_pages;
}
/*
* 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;
enum zone_type j, idx;
for_each_online_pgdat(pgdat) {
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;
idx = j;
while (idx) {
struct zone *lower_zone;
idx--;
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;
}
}
}
/* update totalreserve_pages */
calculate_totalreserve_pages();
}
/**
* 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)
{
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) {
u64 tmp;
spin_lock_irqsave(&zone->lock, flags);
tmp = (u64)pages_min * zone->present_pages;
do_div(tmp, lowmem_pages);
if (is_highmem(zone)) {
/*
* __GFP_HIGH and PF_MEMALLOC allocations usually don't
* need highmem pages, so cap pages_min to a small
* value here.
*
* The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
* deltas controls asynch page reclaim, and so should
* not be capped for highmem.
*/
int min_pages;
min_pages = zone->present_pages / 1024;
if (min_pages < SWAP_CLUSTER_MAX)
min_pages = SWAP_CLUSTER_MAX;
if (min_pages > 128)
min_pages = 128;
zone->watermark[WMARK_MIN] = min_pages;
} else {
/*
* If it's a lowmem zone, reserve a number of pages
* proportionate to the zone's size.
*/
zone->watermark[WMARK_MIN] = tmp;
}
zone->watermark[WMARK_LOW] = min_wmark_pages(zone) + (tmp >> 2);
zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + (tmp >> 1);
setup_zone_migrate_reserve(zone);
spin_unlock_irqrestore(&zone->lock, flags);
}
/* update totalreserve_pages */
calculate_totalreserve_pages();
}
/*
* 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
*/
void calculate_zone_inactive_ratio(struct zone *zone)
{
unsigned int gb, ratio;
/* Zone size in gigabytes */
gb = zone->present_pages >> (30 - PAGE_SHIFT);
if (gb)
ratio = int_sqrt(10 * gb);
else
ratio = 1;
zone->inactive_ratio = ratio;
}
static void __init setup_per_zone_inactive_ratio(void)
{
struct zone *zone;
for_each_zone(zone)
calculate_zone_inactive_ratio(zone);
}
/*
* Initialise min_free_kbytes.
*
* For small machines we want it small (128k min). For large machines
* we want it large (64MB max). But it is not linear, because network
* bandwidth does not increase linearly with machine size. We use
*
* min_free_kbytes = 4 * sqrt(lowmem_kbytes), for better accuracy:
* min_free_kbytes = sqrt(lowmem_kbytes * 16)
*
* which yields
*
* 16MB: 512k
* 32MB: 724k
* 64MB: 1024k
* 128MB: 1448k
* 256MB: 2048k
* 512MB: 2896k
* 1024MB: 4096k
* 2048MB: 5792k
* 4096MB: 8192k
* 8192MB: 11584k
* 16384MB: 16384k
*/
static int __init init_per_zone_wmark_min(void)
{
unsigned long lowmem_kbytes;
lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
if (min_free_kbytes < 128)
min_free_kbytes = 128;
if (min_free_kbytes > 65536)
min_free_kbytes = 65536;
setup_per_zone_wmarks();
setup_per_zone_lowmem_reserve();
setup_per_zone_inactive_ratio();
return 0;
}
module_init(init_per_zone_wmark_min)
/*
* min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
* that we can call two helper functions whenever min_free_kbytes
* changes.
*/
int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos)
{
proc_dointvec(table, write, buffer, length, ppos);
if (write)
setup_per_zone_wmarks();
return 0;
}
#ifdef CONFIG_NUMA
int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos)
{
struct zone *zone;
int rc;
rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
if (rc)
return rc;
for_each_zone(zone)
zone->min_unmapped_pages = (zone->present_pages *
sysctl_min_unmapped_ratio) / 100;
return 0;
}
int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos)
{
struct zone *zone;
int rc;
rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
if (rc)
return rc;
for_each_zone(zone)
zone->min_slab_pages = (zone->present_pages *
sysctl_min_slab_ratio) / 100;
return 0;
}
#endif
/*
* 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
* minimum watermarks. The lowmem reserve ratio can only make sense
* if in function of the boot time zone sizes.
*/
int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos)
{
proc_dointvec_minmax(table, write, buffer, length, ppos);
setup_per_zone_lowmem_reserve();
return 0;
}
/*
* 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,
void __user *buffer, size_t *length, loff_t *ppos)
{
struct zone *zone;
unsigned int cpu;
int ret;
ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
if (!write || (ret == -EINVAL))
return ret;
for_each_populated_zone(zone) {
for_each_possible_cpu(cpu) {
unsigned long high;
high = zone->present_pages / percpu_pagelist_fraction;
setup_pagelist_highmark(
per_cpu_ptr(zone->pageset, cpu), high);
}
}
return 0;
}
int hashdist = HASHDIST_DEFAULT;
#ifdef CONFIG_NUMA
static int __init set_hashdist(char *str)
{
if (!str)
return 0;
hashdist = simple_strtoul(str, &str, 0);
return 1;
}
__setup("hashdist=", set_hashdist);
#endif
/*
* allocate a large system hash table from bootmem
* - it is assumed that the hash table must contain an exact power-of-2
* quantity of entries
* - limit is the number of hash buckets, not the total allocation size
*/
void *__init alloc_large_system_hash(const char *tablename,
unsigned long bucketsize,
unsigned long numentries,
int scale,
int flags,
unsigned int *_hash_shift,
unsigned int *_hash_mask,
unsigned long limit)
{
unsigned long long max = limit;
unsigned long log2qty, size;
void *table = NULL;
/* allow the kernel cmdline to have a say */
if (!numentries) {
/* round applicable memory size up to nearest megabyte */
numentries = nr_kernel_pages;
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);
/* Make sure we've got at least a 0-order allocation.. */
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))
numentries = PAGE_SIZE / bucketsize;
}
numentries = roundup_pow_of_two(numentries);
/* limit allocation size to 1/16 total memory by default */
if (max == 0) {
max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
do_div(max, bucketsize);
}
if (numentries > max)
numentries = max;
log2qty = ilog2(numentries);
do {
size = bucketsize << log2qty;
if (flags & HASH_EARLY)
table = alloc_bootmem_nopanic(size);
else if (hashdist)
table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
else {
/*
* If bucketsize is not a power-of-two, we may free
* some pages at the end of hash table which
* alloc_pages_exact() automatically does
*/
if (get_order(size) < MAX_ORDER) {
table = alloc_pages_exact(size, GFP_ATOMIC);
kmemleak_alloc(table, size, 1, GFP_ATOMIC);
}
}
} while (!table && size > PAGE_SIZE && --log2qty);
if (!table)
panic("Failed to allocate %s hash table\n", tablename);
printk(KERN_INFO "%s hash table entries: %d (order: %d, %lu bytes)\n",
tablename,
(1U << log2qty),
ilog2(size) - PAGE_SHIFT,
size);
if (_hash_shift)
*_hash_shift = log2qty;
if (_hash_mask)
*_hash_mask = (1 << log2qty) - 1;
return table;
}
/* 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);
return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
#else
pfn = pfn - zone->zone_start_pfn;
return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS;
#endif /* CONFIG_SPARSEMEM */
}
/**
* get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
* @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;
return flags;
}
/**
* set_pageblock_flags_group - Set the requested group of flags for a pageblock_nr_pages block of pages
* @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);
VM_BUG_ON(pfn < zone->zone_start_pfn);
VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages);
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);
}
/*
* This is designed as sub function...plz see page_isolation.c also.
* set/clear page block's type to be ISOLATE.
* page allocater never alloc memory from ISOLATE block.
*/
int set_migratetype_isolate(struct page *page)
{
struct zone *zone;
struct page *curr_page;
unsigned long flags, pfn, iter;
unsigned long immobile = 0;
struct memory_isolate_notify arg;
int notifier_ret;
int ret = -EBUSY;
int zone_idx;
zone = page_zone(page);
zone_idx = zone_idx(zone);
spin_lock_irqsave(&zone->lock, flags);
if (get_pageblock_migratetype(page) == MIGRATE_MOVABLE ||
zone_idx == ZONE_MOVABLE) {
ret = 0;
goto out;
}
pfn = page_to_pfn(page);
arg.start_pfn = pfn;
arg.nr_pages = pageblock_nr_pages;
arg.pages_found = 0;
/*
* It may be possible to isolate a pageblock even if the
* migratetype is not MIGRATE_MOVABLE. The memory isolation
* notifier chain is used by balloon drivers to return the
* number of pages in a range that are held by the balloon
* driver to shrink memory. If all the pages are accounted for
* by balloons, are free, or on the LRU, isolation can continue.
* Later, for example, when memory hotplug notifier runs, these
* pages reported as "can be isolated" should be isolated(freed)
* by the balloon driver through the memory notifier chain.
*/
notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);
notifier_ret = notifier_to_errno(notifier_ret);
if (notifier_ret || !arg.pages_found)
goto out;
for (iter = pfn; iter < (pfn + pageblock_nr_pages); iter++) {
if (!pfn_valid_within(pfn))
continue;
curr_page = pfn_to_page(iter);
if (!page_count(curr_page) || PageLRU(curr_page))
continue;
immobile++;
}
if (arg.pages_found == immobile)
ret = 0;
out:
if (!ret) {
set_pageblock_migratetype(page, MIGRATE_ISOLATE);
move_freepages_block(zone, page, MIGRATE_ISOLATE);
}
spin_unlock_irqrestore(&zone->lock, flags);
if (!ret)
drain_all_pages();
return ret;
}
void unset_migratetype_isolate(struct page *page)
{
struct zone *zone;
unsigned long flags;
zone = page_zone(page);
spin_lock_irqsave(&zone->lock, flags);
if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
goto out;
set_pageblock_migratetype(page, MIGRATE_MOVABLE);
move_freepages_block(zone, page, MIGRATE_MOVABLE);
out:
spin_unlock_irqrestore(&zone->lock, flags);
}
#ifdef CONFIG_MEMORY_HOTREMOVE
/*
* All pages in the range must be isolated before calling this.
*/
void
__offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
{
struct page *page;
struct zone *zone;
int order, i;
unsigned long pfn;
unsigned long flags;
/* find the first valid pfn */
for (pfn = start_pfn; pfn < end_pfn; pfn++)
if (pfn_valid(pfn))
break;
if (pfn == end_pfn)
return;
zone = page_zone(pfn_to_page(pfn));
spin_lock_irqsave(&zone->lock, flags);
pfn = start_pfn;
while (pfn < end_pfn) {
if (!pfn_valid(pfn)) {
pfn++;
continue;
}
page = pfn_to_page(pfn);
BUG_ON(page_count(page));
BUG_ON(!PageBuddy(page));
order = page_order(page);
#ifdef CONFIG_DEBUG_VM
printk(KERN_INFO "remove from free list %lx %d %lx\n",
pfn, 1 << order, end_pfn);
#endif
list_del(&page->lru);
rmv_page_order(page);
zone->free_area[order].nr_free--;
__mod_zone_page_state(zone, NR_FREE_PAGES,
- (1UL << order));
for (i = 0; i < (1 << order); i++)
SetPageReserved((page+i));
pfn += (1 << order);
}
spin_unlock_irqrestore(&zone->lock, flags);
}
#endif
#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
static struct trace_print_flags pageflag_names[] = {
{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_buddy, "buddy" },
{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" },
#endif
{-1UL, NULL },
};
static void dump_page_flags(unsigned long flags)
{
const char *delim = "";
unsigned long mask;
int i;
printk(KERN_ALERT "page flags: %#lx(", flags);
/* remove zone id */
flags &= (1UL << NR_PAGEFLAGS) - 1;
for (i = 0; pageflag_names[i].name && flags; i++) {
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",
page, page_count(page), page_mapcount(page),
page->mapping, page->index);
dump_page_flags(page->flags);
}
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