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mm: page_alloc: consolidate free page accounting 

Free page accounting currently happens a bit too high up the call stack,
where it has to deal with guard pages, compaction capturing, block
stealing and even page isolation.  This is subtle and fragile, and makes
it difficult to hack on the code.

Now that type violations on the freelists have been fixed, push the
accounting down to where pages enter and leave the freelist.

[hannes@cmpxchg.org: undo unrelated drive-by line wrap]
  Link: https://lkml.kernel.org/r/20240327185736.GA7597@cmpxchg.org
[hannes@cmpxchg.org: remove unused page parameter from account_freepages()]
  Link: https://lkml.kernel.org/r/20240327185831.GB7597@cmpxchg.org
[baolin.wang@linux.alibaba.com: fix free page accounting]
  Link: https://lkml.kernel.org/r/a2a48baca69f103aa431fd201f8a06e3b95e203d.1712648441.git.baolin.wang@linux.alibaba.com
[andriy.shevchenko@linux.intel.com: avoid defining unused function]
  Link: https://lkml.kernel.org/r/20240423161506.2637177-1-andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20240320180429.678181-11-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Johannes Weiner 2024-03-20 14:02:15 -04:00 committed by Andrew Morton
parent fd919a85cd
commit e0932b6c1f
5 changed files with 118 additions and 117 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
include/linux/mm.h
View File

@ -3797,24 +3797,22 @@ static inline bool page_is_guard(struct page *page)
return PageGuard(page);
}
bool __set_page_guard(struct zone *zone, struct page *page, unsigned int order,
int migratetype);
bool __set_page_guard(struct zone *zone, struct page *page, unsigned int order);
static inline bool set_page_guard(struct zone *zone, struct page *page,
unsigned int order, int migratetype)
unsigned int order)
{
if (!debug_guardpage_enabled())
return false;
return __set_page_guard(zone, page, order, migratetype);
return __set_page_guard(zone, page, order);
}
void __clear_page_guard(struct zone *zone, struct page *page, unsigned int order,
int migratetype);
void __clear_page_guard(struct zone *zone, struct page *page, unsigned int order);
static inline void clear_page_guard(struct zone *zone, struct page *page,
unsigned int order, int migratetype)
unsigned int order)
{
if (!debug_guardpage_enabled())
return;
__clear_page_guard(zone, page, order, migratetype);
__clear_page_guard(zone, page, order);
}
#else /* CONFIG_DEBUG_PAGEALLOC */
@ -3824,9 +3822,9 @@ static inline unsigned int debug_guardpage_minorder(void) { return 0; }
static inline bool debug_guardpage_enabled(void) { return false; }
static inline bool page_is_guard(struct page *page) { return false; }
static inline bool set_page_guard(struct zone *zone, struct page *page,
unsigned int order, int migratetype) { return false; }
unsigned int order) { return false; }
static inline void clear_page_guard(struct zone *zone, struct page *page,
unsigned int order, int migratetype) {}
unsigned int order) {}
#endif /* CONFIG_DEBUG_PAGEALLOC */
#ifdef __HAVE_ARCH_GATE_AREA

8
include/linux/vmstat.h
View File

@ -487,14 +487,6 @@ static inline void node_stat_sub_folio(struct folio *folio,
mod_node_page_state(folio_pgdat(folio), item, -folio_nr_pages(folio));
}
static inline void __mod_zone_freepage_state(struct zone *zone, int nr_pages,
int migratetype)
{
__mod_zone_page_state(zone, NR_FREE_PAGES, nr_pages);
if (is_migrate_cma(migratetype))
__mod_zone_page_state(zone, NR_FREE_CMA_PAGES, nr_pages);
}
extern const char * const vmstat_text[];
static inline const char *zone_stat_name(enum zone_stat_item item)

12
mm/debug_page_alloc.c
View File

@ -32,8 +32,7 @@ static int __init debug_guardpage_minorder_setup(char *buf)
}
early_param("debug_guardpage_minorder", debug_guardpage_minorder_setup);
bool __set_page_guard(struct zone *zone, struct page *page, unsigned int order,
int migratetype)
bool __set_page_guard(struct zone *zone, struct page *page, unsigned int order)
{
if (order >= debug_guardpage_minorder())
return false;
@ -41,19 +40,12 @@ bool __set_page_guard(struct zone *zone, struct page *page, unsigned int order,
__SetPageGuard(page);
INIT_LIST_HEAD(&page->buddy_list);
set_page_private(page, order);
/* Guard pages are not available for any usage */
if (!is_migrate_isolate(migratetype))
__mod_zone_freepage_state(zone, -(1 << order), migratetype);
return true;
}
void __clear_page_guard(struct zone *zone, struct page *page, unsigned int order,
int migratetype)
void __clear_page_guard(struct zone *zone, struct page *page, unsigned int order)
{
__ClearPageGuard(page);
set_page_private(page, 0);
if (!is_migrate_isolate(migratetype))
__mod_zone_freepage_state(zone, (1 << order), migratetype);
}

5
mm/internal.h
View File

@ -1039,11 +1039,6 @@ static inline bool is_migrate_highatomic(enum migratetype migratetype)
return migratetype == MIGRATE_HIGHATOMIC;
}
static inline bool is_migrate_highatomic_page(struct page *page)
{
return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
}
void setup_zone_pageset(struct zone *zone);
struct migration_target_control {

192
mm/page_alloc.c
View File

@ -643,23 +643,33 @@ compaction_capture(struct capture_control *capc, struct page *page,
}
#endif /* CONFIG_COMPACTION */
/* Used for pages not on another list */
static inline void add_to_free_list(struct page *page, struct zone *zone,
unsigned int order, int migratetype)
static inline void account_freepages(struct zone *zone, int nr_pages,
int migratetype)
{
struct free_area *area = &zone->free_area[order];
if (is_migrate_isolate(migratetype))
return;
list_add(&page->buddy_list, &area->free_list[migratetype]);
area->nr_free++;
__mod_zone_page_state(zone, NR_FREE_PAGES, nr_pages);
if (is_migrate_cma(migratetype))
__mod_zone_page_state(zone, NR_FREE_CMA_PAGES, nr_pages);
}
/* Used for pages not on another list */
static inline void add_to_free_list_tail(struct page *page, struct zone *zone,
unsigned int order, int migratetype)
static inline void __add_to_free_list(struct page *page, struct zone *zone,
unsigned int order, int migratetype,
bool tail)
{
struct free_area *area = &zone->free_area[order];
list_add_tail(&page->buddy_list, &area->free_list[migratetype]);
VM_WARN_ONCE(get_pageblock_migratetype(page) != migratetype,
"page type is %lu, passed migratetype is %d (nr=%d)\n",
get_pageblock_migratetype(page), migratetype, 1 << order);
if (tail)
list_add_tail(&page->buddy_list, &area->free_list[migratetype]);
else
list_add(&page->buddy_list, &area->free_list[migratetype]);
area->nr_free++;
}
@ -669,16 +679,28 @@ static inline void add_to_free_list_tail(struct page *page, struct zone *zone,
* allocation again (e.g., optimization for memory onlining).
*/
static inline void move_to_free_list(struct page *page, struct zone *zone,
unsigned int order, int migratetype)
unsigned int order, int old_mt, int new_mt)
{
struct free_area *area = &zone->free_area[order];
list_move_tail(&page->buddy_list, &area->free_list[migratetype]);
/* Free page moving can fail, so it happens before the type update */
VM_WARN_ONCE(get_pageblock_migratetype(page) != old_mt,
"page type is %lu, passed migratetype is %d (nr=%d)\n",
get_pageblock_migratetype(page), old_mt, 1 << order);
list_move_tail(&page->buddy_list, &area->free_list[new_mt]);
account_freepages(zone, -(1 << order), old_mt);
account_freepages(zone, 1 << order, new_mt);
}
static inline void del_page_from_free_list(struct page *page, struct zone *zone,
unsigned int order)
static inline void __del_page_from_free_list(struct page *page, struct zone *zone,
unsigned int order, int migratetype)
{
VM_WARN_ONCE(get_pageblock_migratetype(page) != migratetype,
"page type is %lu, passed migratetype is %d (nr=%d)\n",
get_pageblock_migratetype(page), migratetype, 1 << order);
/* clear reported state and update reported page count */
if (page_reported(page))
__ClearPageReported(page);
@ -689,6 +711,13 @@ static inline void del_page_from_free_list(struct page *page, struct zone *zone,
zone->free_area[order].nr_free--;
}
static inline void del_page_from_free_list(struct page *page, struct zone *zone,
unsigned int order, int migratetype)
{
__del_page_from_free_list(page, zone, order, migratetype);
account_freepages(zone, -(1 << order), migratetype);
}
static inline struct page *get_page_from_free_area(struct free_area *area,
int migratetype)
{
@ -760,16 +789,16 @@ static inline void __free_one_page(struct page *page,
VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
VM_BUG_ON(migratetype == -1);
if (likely(!is_migrate_isolate(migratetype)))
__mod_zone_freepage_state(zone, 1 << order, migratetype);
VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page);
VM_BUG_ON_PAGE(bad_range(zone, page), page);
account_freepages(zone, 1 << order, migratetype);
while (order < MAX_PAGE_ORDER) {
int buddy_mt = migratetype;
if (compaction_capture(capc, page, order, migratetype)) {
__mod_zone_freepage_state(zone, -(1 << order),
migratetype);
account_freepages(zone, -(1 << order), migratetype);
return;
}
@ -784,19 +813,12 @@ static inline void __free_one_page(struct page *page,
* pageblock isolation could cause incorrect freepage or CMA
* accounting or HIGHATOMIC accounting.
*/
int buddy_mt = get_pfnblock_migratetype(buddy, buddy_pfn);
buddy_mt = get_pfnblock_migratetype(buddy, buddy_pfn);
if (migratetype != buddy_mt) {
if (!migratetype_is_mergeable(migratetype) ||
!migratetype_is_mergeable(buddy_mt))
goto done_merging;
/*
* Match buddy type. This ensures that
* an expand() down the line puts the
* sub-blocks on the right freelists.
*/
set_pageblock_migratetype(buddy, migratetype);
}
if (migratetype != buddy_mt &&
(!migratetype_is_mergeable(migratetype) ||
!migratetype_is_mergeable(buddy_mt)))
goto done_merging;
}
/*
@ -804,9 +826,19 @@ static inline void __free_one_page(struct page *page,
* merge with it and move up one order.
*/
if (page_is_guard(buddy))
clear_page_guard(zone, buddy, order, migratetype);
clear_page_guard(zone, buddy, order);
else
del_page_from_free_list(buddy, zone, order);
__del_page_from_free_list(buddy, zone, order, buddy_mt);
if (unlikely(buddy_mt != migratetype)) {
/*
* Match buddy type. This ensures that an
* expand() down the line puts the sub-blocks
* on the right freelists.
*/
set_pageblock_migratetype(buddy, migratetype);
}
combined_pfn = buddy_pfn & pfn;
page = page + (combined_pfn - pfn);
pfn = combined_pfn;
@ -823,10 +855,7 @@ done_merging:
else
to_tail = buddy_merge_likely(pfn, buddy_pfn, page, order);
if (to_tail)
add_to_free_list_tail(page, zone, order, migratetype);
else
add_to_free_list(page, zone, order, migratetype);
__add_to_free_list(page, zone, order, migratetype, to_tail);
/* Notify page reporting subsystem of freed page */
if (!(fpi_flags & FPI_SKIP_REPORT_NOTIFY))
@ -1318,10 +1347,10 @@ static inline void expand(struct zone *zone, struct page *page,
* Corresponding page table entries will not be touched,
* pages will stay not present in virtual address space
*/
if (set_page_guard(zone, &page[size], high, migratetype))
if (set_page_guard(zone, &page[size], high))
continue;
add_to_free_list(&page[size], zone, high, migratetype);
add_to_free_list(&page[size], zone, high, migratetype, false);
set_buddy_order(&page[size], high);
}
}
@ -1492,7 +1521,7 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
page = get_page_from_free_area(area, migratetype);
if (!page)
continue;
del_page_from_free_list(page, zone, current_order);
del_page_from_free_list(page, zone, current_order, migratetype);
expand(zone, page, order, current_order, migratetype);
trace_mm_page_alloc_zone_locked(page, order, migratetype,
pcp_allowed_order(order) &&
@ -1532,7 +1561,7 @@ static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
* type's freelist.
*/
static int move_freepages(struct zone *zone, unsigned long start_pfn,
unsigned long end_pfn, int migratetype)
unsigned long end_pfn, int old_mt, int new_mt)
{
struct page *page;
unsigned long pfn;
@ -1554,12 +1583,14 @@ static int move_freepages(struct zone *zone, unsigned long start_pfn,
VM_BUG_ON_PAGE(page_zone(page) != zone, page);
order = buddy_order(page);
move_to_free_list(page, zone, order, migratetype);
move_to_free_list(page, zone, order, old_mt, new_mt);
pfn += 1 << order;
pages_moved += 1 << order;
}
set_pageblock_migratetype(pfn_to_page(start_pfn), migratetype);
set_pageblock_migratetype(pfn_to_page(start_pfn), new_mt);
return pages_moved;
}
@ -1617,7 +1648,7 @@ static bool prep_move_freepages_block(struct zone *zone, struct page *page,
}
static int move_freepages_block(struct zone *zone, struct page *page,
int migratetype)
int old_mt, int new_mt)
{
unsigned long start_pfn, end_pfn;
@ -1625,7 +1656,7 @@ static int move_freepages_block(struct zone *zone, struct page *page,
NULL, NULL))
return -1;
return move_freepages(zone, start_pfn, end_pfn, migratetype);
return move_freepages(zone, start_pfn, end_pfn, old_mt, new_mt);
}
#ifdef CONFIG_MEMORY_ISOLATION
@ -1697,7 +1728,6 @@ bool move_freepages_block_isolate(struct zone *zone, struct page *page,
int migratetype)
{
unsigned long start_pfn, end_pfn, pfn;
int nr_moved, mt;
if (!prep_move_freepages_block(zone, page, &start_pfn, &end_pfn,
NULL, NULL))
@ -1712,11 +1742,9 @@ bool move_freepages_block_isolate(struct zone *zone, struct page *page,
if (pfn != start_pfn) {
struct page *buddy = pfn_to_page(pfn);
int order = buddy_order(buddy);
int mt = get_pfnblock_migratetype(buddy, pfn);
if (!is_migrate_isolate(mt))
__mod_zone_freepage_state(zone, -(1UL << order), mt);
del_page_from_free_list(buddy, zone, order);
del_page_from_free_list(buddy, zone, order,
get_pfnblock_migratetype(buddy, pfn));
set_pageblock_migratetype(page, migratetype);
split_large_buddy(zone, buddy, pfn, order);
return true;
@ -1724,23 +1752,17 @@ bool move_freepages_block_isolate(struct zone *zone, struct page *page,
/* We're the starting block of a larger buddy */
if (PageBuddy(page) && buddy_order(page) > pageblock_order) {
int mt = get_pfnblock_migratetype(page, pfn);
int order = buddy_order(page);
if (!is_migrate_isolate(mt))
__mod_zone_freepage_state(zone, -(1UL << order), mt);
del_page_from_free_list(page, zone, order);
del_page_from_free_list(page, zone, order,
get_pfnblock_migratetype(page, pfn));
set_pageblock_migratetype(page, migratetype);
split_large_buddy(zone, page, pfn, order);
return true;
}
move:
mt = get_pfnblock_migratetype(page, start_pfn);
nr_moved = move_freepages(zone, start_pfn, end_pfn, migratetype);
if (!is_migrate_isolate(mt))
__mod_zone_freepage_state(zone, -nr_moved, mt);
else if (!is_migrate_isolate(migratetype))
__mod_zone_freepage_state(zone, nr_moved, migratetype);
move_freepages(zone, start_pfn, end_pfn,
get_pfnblock_migratetype(page, start_pfn), migratetype);
return true;
}
#endif /* CONFIG_MEMORY_ISOLATION */
@ -1854,7 +1876,7 @@ steal_suitable_fallback(struct zone *zone, struct page *page,
/* Take ownership for orders >= pageblock_order */
if (current_order >= pageblock_order) {
del_page_from_free_list(page, zone, current_order);
del_page_from_free_list(page, zone, current_order, block_type);
change_pageblock_range(page, current_order, start_type);
expand(zone, page, order, current_order, start_type);
return page;
@ -1904,12 +1926,12 @@ steal_suitable_fallback(struct zone *zone, struct page *page,
*/
if (free_pages + alike_pages >= (1 << (pageblock_order-1)) ||
page_group_by_mobility_disabled) {
move_freepages(zone, start_pfn, end_pfn, start_type);
move_freepages(zone, start_pfn, end_pfn, block_type, start_type);
return __rmqueue_smallest(zone, order, start_type);
}
single_page:
del_page_from_free_list(page, zone, current_order);
del_page_from_free_list(page, zone, current_order, block_type);
expand(zone, page, order, current_order, block_type);
return page;
}
@ -1979,7 +2001,7 @@ static void reserve_highatomic_pageblock(struct page *page, struct zone *zone)
mt = get_pageblock_migratetype(page);
/* Only reserve normal pageblocks (i.e., they can merge with others) */
if (migratetype_is_mergeable(mt))
if (move_freepages_block(zone, page,
if (move_freepages_block(zone, page, mt,
MIGRATE_HIGHATOMIC) != -1)
zone->nr_reserved_highatomic += pageblock_nr_pages;
@ -2020,11 +2042,13 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
spin_lock_irqsave(&zone->lock, flags);
for (order = 0; order < NR_PAGE_ORDERS; order++) {
struct free_area *area = &(zone->free_area[order]);
int mt;
page = get_page_from_free_area(area, MIGRATE_HIGHATOMIC);
if (!page)
continue;
mt = get_pageblock_migratetype(page);
/*
* In page freeing path, migratetype change is racy so
* we can counter several free pages in a pageblock
@ -2032,7 +2056,7 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
* from highatomic to ac->migratetype. So we should
* adjust the count once.
*/
if (is_migrate_highatomic_page(page)) {
if (is_migrate_highatomic(mt)) {
/*
* It should never happen but changes to
* locking could inadvertently allow a per-cpu
@ -2054,7 +2078,8 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
* of pageblocks that cannot be completely freed
* may increase.
*/
ret = move_freepages_block(zone, page, ac->migratetype);
ret = move_freepages_block(zone, page, mt,
ac->migratetype);
/*
* Reserving this block already succeeded, so this should
* not fail on zone boundaries.
@ -2225,12 +2250,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
* pages are ordered properly.
*/
list_add_tail(&page->pcp_list, list);
if (is_migrate_cma(get_pageblock_migratetype(page)))
__mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
-(1 << order));
}
__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
spin_unlock_irqrestore(&zone->lock, flags);
return i;
@ -2723,11 +2743,9 @@ int __isolate_free_page(struct page *page, unsigned int order)
watermark = zone->_watermark[WMARK_MIN] + (1UL << order);
if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA))
return 0;
__mod_zone_freepage_state(zone, -(1UL << order), mt);
}
del_page_from_free_list(page, zone, order);
del_page_from_free_list(page, zone, order, mt);
/*
* Set the pageblock if the isolated page is at least half of a
@ -2742,7 +2760,7 @@ int __isolate_free_page(struct page *page, unsigned int order)
* with others)
*/
if (migratetype_is_mergeable(mt))
move_freepages_block(zone, page,
move_freepages_block(zone, page, mt,
MIGRATE_MOVABLE);
}
}
@ -2827,8 +2845,6 @@ struct page *rmqueue_buddy(struct zone *preferred_zone, struct zone *zone,
return NULL;
}
}
__mod_zone_freepage_state(zone, -(1 << order),
get_pageblock_migratetype(page));
spin_unlock_irqrestore(&zone->lock, flags);
} while (check_new_pages(page, order));
@ -6716,8 +6732,9 @@ void __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
BUG_ON(page_count(page));
BUG_ON(!PageBuddy(page));
VM_WARN_ON(get_pageblock_migratetype(page) != MIGRATE_ISOLATE);
order = buddy_order(page);
del_page_from_free_list(page, zone, order);
del_page_from_free_list(page, zone, order, MIGRATE_ISOLATE);
pfn += (1 << order);
}
spin_unlock_irqrestore(&zone->lock, flags);
@ -6745,6 +6762,14 @@ bool is_free_buddy_page(struct page *page)
EXPORT_SYMBOL(is_free_buddy_page);
#ifdef CONFIG_MEMORY_FAILURE
static inline void add_to_free_list(struct page *page, struct zone *zone,
unsigned int order, int migratetype,
bool tail)
{
__add_to_free_list(page, zone, order, migratetype, tail);
account_freepages(zone, 1 << order, migratetype);
}
/*
* Break down a higher-order page in sub-pages, and keep our target out of
* buddy allocator.
@ -6767,10 +6792,10 @@ static void break_down_buddy_pages(struct zone *zone, struct page *page,
current_buddy = page + size;
}
if (set_page_guard(zone, current_buddy, high, migratetype))
if (set_page_guard(zone, current_buddy, high))
continue;
add_to_free_list(current_buddy, zone, high, migratetype);
add_to_free_list(current_buddy, zone, high, migratetype, false);
set_buddy_order(current_buddy, high);
}
}
@ -6796,12 +6821,11 @@ bool take_page_off_buddy(struct page *page)
int migratetype = get_pfnblock_migratetype(page_head,
pfn_head);
del_page_from_free_list(page_head, zone, page_order);
del_page_from_free_list(page_head, zone, page_order,
migratetype);
break_down_buddy_pages(zone, page_head, page, 0,
page_order, migratetype);
SetPageHWPoisonTakenOff(page);
if (!is_migrate_isolate(migratetype))
__mod_zone_freepage_state(zone, -1, migratetype);
ret = true;
break;
}
@ -6909,7 +6933,7 @@ static bool try_to_accept_memory_one(struct zone *zone)
list_del(&page->lru);
last = list_empty(&zone->unaccepted_pages);
__mod_zone_freepage_state(zone, -MAX_ORDER_NR_PAGES, MIGRATE_MOVABLE);
account_freepages(zone, -MAX_ORDER_NR_PAGES, MIGRATE_MOVABLE);
__mod_zone_page_state(zone, NR_UNACCEPTED, -MAX_ORDER_NR_PAGES);
spin_unlock_irqrestore(&zone->lock, flags);
@ -6961,7 +6985,7 @@ static bool __free_unaccepted(struct page *page)
spin_lock_irqsave(&zone->lock, flags);
first = list_empty(&zone->unaccepted_pages);
list_add_tail(&page->lru, &zone->unaccepted_pages);
__mod_zone_freepage_state(zone, MAX_ORDER_NR_PAGES, MIGRATE_MOVABLE);
account_freepages(zone, MAX_ORDER_NR_PAGES, MIGRATE_MOVABLE);
__mod_zone_page_state(zone, NR_UNACCEPTED, MAX_ORDER_NR_PAGES);
spin_unlock_irqrestore(&zone->lock, flags);