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From: William Lee Irwin III <wli@holomorphy.com>
To: linux-mm@kvack.org
Subject: lazy buddy prototype
Date: Tue, 21 May 2002 10:50:05 -0700
Cc: linux-kernel@vger.kernel.org
Brewed this one up Sunday. Lightly tested. i386-only. Also available from
bk://linux-wli.bkbits.net/lazy_buddy
ftp://ftp.kernel.org/pub/linux/kernel/wli/vm/lazy_buddy/lazy_buddy-2.5.17-1
TODO:
(1) remove debug code
(2) move the work in dequeue()/enqueue() to buddy_alloc()/buddy_free()
(3) use dequeue() and enqueue() for address-ordered queueing
(4) write lg() for other architectures or use something else
(5) kill boottime_defragment()
(6) stress testing, find bugs if present
(7) benchmarking
(8) audit for unnecessary cacheline dirtying
(9) audit for proper obeisance of the reclaiming/accelerated thresholds
(10) port to 2.4.x & rmap
(11) optimize
(12) figure out if the mask twiddling for ->deferred_pages[] is worth it
(13) figure out some way to get fragmentation stats out of the buddy bitmap
Cheers,
Bill
diff -urN --exclude [psx].* linux-2.5/fs/proc/proc_misc.c lazy_buddy-2.5/fs/proc/proc_misc.c
--- linux-2.5/fs/proc/proc_misc.c Tue May 21 08:24:43 2002
+++ lazy_buddy-2.5/fs/proc/proc_misc.c Tue May 21 09:02:34 2002
@@ -132,6 +132,7 @@
int len;
int pg_size ;
struct page_state ps;
+ extern unsigned long nr_deferred_pages(void);
get_page_state(&ps);
/*
@@ -161,7 +162,8 @@
"SwapTotal: %8lu kB\n"
"SwapFree: %8lu kB\n"
"Dirty: %8lu kB\n"
- "Writeback: %8lu kB\n",
+ "Writeback: %8lu kB\n"
+ "Deferred: %8lu kB\n",
K(i.totalram),
K(i.freeram),
K(i.sharedram),
@@ -177,7 +179,8 @@
K(i.totalswap),
K(i.freeswap),
K(ps.nr_dirty),
- K(ps.nr_writeback)
+ K(ps.nr_writeback),
+ K(nr_deferred_pages())
);
return proc_calc_metrics(page, start, off, count, eof, len);
diff -urN --exclude [psx].* linux-2.5/include/asm-i386/bitops.h lazy_buddy-2.5/include/asm-i386/bitops.h
--- linux-2.5/include/asm-i386/bitops.h Tue May 21 08:24:57 2002
+++ lazy_buddy-2.5/include/asm-i386/bitops.h Tue May 21 09:02:40 2002
@@ -401,6 +401,20 @@
}
/**
+ * lg - integer logarithm, or floor(ln(n)/ln(2))
+ * @word: The word to search
+ *
+ * Undefined if 0, one should check against 0 first.
+ */
+static inline unsigned long lg(unsigned long n)
+{
+ __asm__("bsrl %1,%0"
+ :"=r" (n)
+ :"r" (n));
+ return n;
+}
+
+/**
* __ffs - find first bit in word.
* @word: The word to search
*
diff -urN --exclude [psx].* linux-2.5/include/linux/mmzone.h lazy_buddy-2.5/include/linux/mmzone.h
--- linux-2.5/include/linux/mmzone.h Tue May 21 08:25:24 2002
+++ lazy_buddy-2.5/include/linux/mmzone.h Tue May 21 09:03:04 2002
@@ -42,11 +42,15 @@
unsigned long free_pages;
unsigned long pages_min, pages_low, pages_high;
int need_balance;
+ unsigned long pages_granted;
+ unsigned long pages_deferred;
/*
* free areas of different sizes
*/
free_area_t free_area[MAX_ORDER];
+ unsigned long deferred_mask;
+ list_t deferred_pages[MAX_ORDER];
/*
* wait_table -- the array holding the hash table
@@ -144,6 +148,11 @@
#define memclass(pgzone, classzone) (((pgzone)->zone_pgdat == (classzone)->zone_pgdat) \
&& ((pgzone) <= (classzone)))
+
+static inline unsigned long zone_free_pages(zone_t *zone)
+{
+ return zone->free_pages + zone->pages_deferred;
+}
/*
* The following two are not meant for general usage. They are here as
diff -urN --exclude [psx].* linux-2.5/include/linux/page-flags.h lazy_buddy-2.5/include/linux/page-flags.h
--- linux-2.5/include/linux/page-flags.h Tue May 21 08:25:24 2002
+++ lazy_buddy-2.5/include/linux/page-flags.h Tue May 21 09:03:05 2002
@@ -64,6 +64,7 @@
#define PG_private 12 /* Has something at ->private */
#define PG_writeback 13 /* Page is under writeback */
+#define PG_deferred 14 /* page not marked in buddy bitmap */
/*
* Global page accounting. One instance per CPU.
@@ -174,6 +175,17 @@
#define SetPagePrivate(page) set_bit(PG_private, &(page)->flags)
#define ClearPagePrivate(page) clear_bit(PG_private, &(page)->flags)
#define PagePrivate(page) test_bit(PG_private, &(page)->flags)
+
+#ifdef DEBUG_LAZY_BUDDY
+#if DEBUG_LAZY_BUDDY > 0
+#define PageDeferred(page) test_bit(PG_deferred, &(page)->flags)
+#define SetPageDeferred(page) set_bit(PG_deferred, &(page)->flags)
+#define ClearPageDeferred(page) clear_bit(PG_deferred, &(page)->flags)
+#else
+#define SetPageDeferred(page) do { ; } while(0)
+#define ClearPageDeferred(page) do { ; } while(0)
+#endif /* DEBUG_LAZY_BUDDY > 0 */
+#endif /* DEBUG_LAZY_BUDDY */
#define PageWriteback(page) test_bit(PG_writeback, &(page)->flags)
#define SetPageWriteback(page) \
diff -urN --exclude [psx].* linux-2.5/mm/bootmem.c lazy_buddy-2.5/mm/bootmem.c
--- linux-2.5/mm/bootmem.c Tue May 21 08:25:32 2002
+++ lazy_buddy-2.5/mm/bootmem.c Tue May 21 09:03:11 2002
@@ -241,6 +241,7 @@
return ret;
}
+extern void FASTCALL(boottime_defragment(zone_t *zone));
static unsigned long __init free_all_bootmem_core(pg_data_t *pgdat)
{
struct page *page = pgdat->node_mem_map;
@@ -287,6 +288,9 @@
}
total += count;
bdata->node_bootmem_map = NULL;
+
+ for (i = 0; i < MAX_NR_ZONES; ++i)
+ boottime_defragment(&pgdat->node_zones[i]);
return total;
}
diff -urN --exclude [psx].* linux-2.5/mm/page_alloc.c lazy_buddy-2.5/mm/page_alloc.c
--- linux-2.5/mm/page_alloc.c Tue May 21 08:25:33 2002
+++ lazy_buddy-2.5/mm/page_alloc.c Tue May 21 09:03:11 2002
@@ -12,6 +12,8 @@
* Zone balancing, Kanoj Sarcar, SGI, Jan 2000
*/
+#define DEBUG_LAZY_BUDDY 0
+
#include <linux/config.h>
#include <linux/mm.h>
#include <linux/swap.h>
@@ -71,6 +73,47 @@
|| ((zone) != page_zone(page)) \
)
+#if DEBUG_LAZY_BUDDY > 0
+#define LAZY_BUG_ON(p) BUG_ON(p)
+#else
+#define LAZY_BUG_ON(p) do { ; } while(0)
+#endif
+
+#if DEBUG_LAZY_BUDDY > 1
+static void FASTCALL(check_deferred(zone_t *zone));
+static void check_deferred(zone_t *zone)
+{
+ int order;
+ list_t *elem;
+ unsigned long incr = 1;
+ unsigned long counted_deferred = 0;
+ struct page *page;
+
+ for (order = 0; order < MAX_ORDER; ++order) {
+ list_for_each(elem, &zone->deferred_pages[order]) {
+ counted_deferred += incr;
+ page = list_entry(elem, struct page, list);
+ BUG_ON(!PageDeferred(page));
+ }
+
+ incr <<= 1;
+ }
+ if (counted_deferred == zone->pages_deferred)
+ return;
+
+ printk("zone %s: deferred = %lu, zone->pages_deferred = %lu\n",
+ zone->name,
+ counted_deferred,
+ zone->pages_deferred);
+ BUG();
+}
+#else
+static inline void check_deferred(zone_t *zone)
+{
+ return;
+}
+#endif /* DEBUG_LAZY_BUDDY */
+
/*
* Freeing function for a buddy system allocator.
*
@@ -91,35 +134,19 @@
* -- wli
*/
-static void FASTCALL(__free_pages_ok (struct page *page, unsigned int order));
-static void __free_pages_ok (struct page *page, unsigned int order)
+static void FASTCALL(enqueue(struct page *, int order));
+static void enqueue(struct page *page, int order)
{
- unsigned long index, page_idx, mask, flags;
+ unsigned long index, page_idx, mask;
free_area_t *area;
struct page *base;
zone_t *zone;
- if (PagePrivate(page))
- BUG();
- if (page->mapping)
- BUG();
- if (PageLocked(page))
- BUG();
- if (PageLRU(page))
- BUG();
- if (PageActive(page))
- BUG();
- if (PageWriteback(page))
- BUG();
- ClearPageDirty(page);
- page->flags &= ~(1<<PG_referenced);
-
if (current->flags & PF_FREE_PAGES)
goto local_freelist;
- back_local_freelist:
+back_local_freelist:
zone = page_zone(page);
-
mask = (~0UL) << order;
base = zone->zone_mem_map;
page_idx = page - base;
@@ -129,8 +156,6 @@
area = zone->free_area + order;
- spin_lock_irqsave(&zone->lock, flags);
-
zone->free_pages -= mask;
while (mask + (1 << (MAX_ORDER-1))) {
@@ -163,10 +188,9 @@
}
memlist_add_head(&(base + page_idx)->list, &area->free_list);
- spin_unlock_irqrestore(&zone->lock, flags);
return;
- local_freelist:
+local_freelist:
if (current->nr_local_pages)
goto back_local_freelist;
if (in_interrupt())
@@ -177,6 +201,166 @@
current->nr_local_pages++;
}
+static void FASTCALL(buddy_free(struct page *page, unsigned int order));
+static void buddy_free(struct page *page, unsigned int order)
+{
+ LAZY_BUG_ON(PageDeferred(page));
+ enqueue(page, order);
+}
+
+static void FASTCALL(low_level_free(struct page *page, unsigned int order));
+static void low_level_free(struct page *page, unsigned int order)
+{
+ zone_t *zone = page_zone(page);
+ unsigned long offset;
+ unsigned long flags;
+ unsigned long nr_pages = 1UL << order;
+
+ spin_lock_irqsave(&zone->lock, flags);
+ check_deferred(zone);
+
+ offset = page - zone->zone_mem_map;
+
+ LAZY_BUG_ON(offset & (nr_pages - 1));
+ LAZY_BUG_ON(zone->pages_granted < zone->pages_deferred);
+ LAZY_BUG_ON(PageDeferred(page));
+
+ if (zone->pages_granted >= nr_pages)
+ zone->pages_granted -= nr_pages;
+ else
+ zone->pages_granted = 0;
+
+ /*
+ * This check appears different from the strict invariant enforcement
+ * because it anticipates pages_granted falling below pages_deferred.
+ * One of the ugly things here is that we've already subtracted
+ * nr_pages from pages_granted.
+ */
+ if (unlikely(zone->pages_granted < zone->pages_deferred + nr_pages))
+ goto use_buddy;
+
+ zone->pages_deferred += nr_pages;
+
+ if (unlikely(!test_bit(order, &zone->deferred_mask)))
+ __set_bit(order, &zone->deferred_mask);
+ else
+ LAZY_BUG_ON(list_empty(&zone->deferred_pages[order]));
+
+ LAZY_BUG_ON((page - zone->zone_mem_map) & (nr_pages - 1));
+ list_add(&page->list, &zone->deferred_pages[order]);
+ SetPageDeferred(page);
+
+out_check:
+ LAZY_BUG_ON(zone->pages_granted < zone->pages_deferred);
+ check_deferred(zone);
+ spin_unlock_irqrestore(&zone->lock, flags);
+ return;
+
+use_buddy:
+ LAZY_BUG_ON((page - zone->zone_mem_map) & (nr_pages - 1));
+ buddy_free(page, order);
+
+ if (likely(zone->pages_granted > zone->pages_deferred + 1))
+ goto out_check;
+
+keep_freeing:
+ /* grab another deferred page to coalesce */
+ if (unlikely(!zone->deferred_mask))
+ goto out_check;
+
+ order = lg(zone->deferred_mask);
+ nr_pages = 1UL << order;
+ LAZY_BUG_ON(order >= MAX_ORDER);
+ LAZY_BUG_ON(list_empty(&zone->deferred_pages[order]));
+
+ page = list_entry(zone->deferred_pages[order].next, struct page, list);
+ list_del_init(&page->list);
+ if (list_empty(&zone->deferred_pages[order]))
+ __clear_bit(order, &zone->deferred_mask);
+ else
+ LAZY_BUG_ON(!test_bit(order, &zone->deferred_mask));
+
+ LAZY_BUG_ON((page - zone->zone_mem_map) & (nr_pages - 1));
+ LAZY_BUG_ON(zone->pages_deferred < nr_pages);
+ LAZY_BUG_ON(!PageDeferred(page));
+ ClearPageDeferred(page);
+
+ buddy_free(page, order);
+ zone->pages_deferred -= nr_pages;
+ if (unlikely(zone->pages_granted < zone->pages_deferred))
+ goto keep_freeing;
+
+ check_deferred(zone);
+ LAZY_BUG_ON(zone->pages_granted < zone->pages_deferred);
+ spin_unlock_irqrestore(&zone->lock, flags);
+}
+
+void FASTCALL(boottime_defragment(zone_t *zone));
+void boottime_defragment(zone_t *zone)
+{
+ int order;
+ struct page *page;
+ unsigned int nr_pages;
+ unsigned long offset;
+
+ if (!zone->size)
+ return;
+
+ check_deferred(zone);
+
+ for (order = MAX_ORDER - 1; order >= 0; --order) {
+ nr_pages = 1UL << order;
+ while (!list_empty(&zone->deferred_pages[order])) {
+ page = list_entry(zone->deferred_pages[order].next,
+ struct page,
+ list);
+ offset = page - zone->zone_mem_map;
+ if (unlikely(offset & (nr_pages - 1))) {
+ printk("page %p, bad offset %lx\n",
+ page,
+ offset);
+ BUG();
+ }
+ if (unlikely((unsigned long)page > MAXMEM)) {
+ printk("page %p above MAXMEM=%lx\n",
+ page,
+ MAXMEM);
+ BUG();
+ }
+ LAZY_BUG_ON(!PageDeferred(page));
+ ClearPageDeferred(page);
+ list_del_init(&page->list);
+ buddy_free(page, order);
+ LAZY_BUG_ON(zone->pages_deferred < nr_pages);
+ zone->pages_deferred -= nr_pages;
+ }
+ LAZY_BUG_ON(!list_empty(&zone->deferred_pages[order]));
+ __clear_bit(order, &zone->deferred_mask);
+ }
+ check_deferred(zone);
+}
+
+static void FASTCALL(__free_pages_ok (struct page *page, unsigned int order));
+static void __free_pages_ok (struct page *page, unsigned int order)
+{
+ if (PagePrivate(page))
+ BUG();
+ if (page->mapping)
+ BUG();
+ if (PageLocked(page))
+ BUG();
+ if (PageLRU(page))
+ BUG();
+ if (PageActive(page))
+ BUG();
+ if (PageWriteback(page))
+ BUG();
+ ClearPageDirty(page);
+ page->flags &= ~(1<<PG_referenced);
+ LAZY_BUG_ON((page - page_zone(page)->zone_mem_map) & ((1UL << order) - 1));
+ low_level_free(page, order);
+}
+
#define MARK_USED(index, order, area) \
__change_bit((index) >> (1+(order)), (area)->map)
@@ -201,16 +385,14 @@
return page;
}
-static FASTCALL(struct page * rmqueue(zone_t *zone, unsigned int order));
-static struct page * rmqueue(zone_t *zone, unsigned int order)
+static FASTCALL(struct page * dequeue(zone_t *zone, unsigned int order));
+static struct page * dequeue(zone_t *zone, unsigned int order)
{
free_area_t * area = zone->free_area + order;
unsigned int curr_order = order;
struct list_head *head, *curr;
- unsigned long flags;
struct page *page;
- spin_lock_irqsave(&zone->lock, flags);
do {
head = &area->free_list;
curr = memlist_next(head);
@@ -228,8 +410,6 @@
zone->free_pages -= 1UL << order;
page = expand(zone, page, index, order, curr_order, area);
- spin_unlock_irqrestore(&zone->lock, flags);
-
set_page_count(page, 1);
if (BAD_RANGE(zone,page))
BUG();
@@ -242,11 +422,132 @@
curr_order++;
area++;
} while (curr_order < MAX_ORDER);
- spin_unlock_irqrestore(&zone->lock, flags);
return NULL;
}
+static FASTCALL(struct page *buddy_alloc(zone_t *zone, unsigned int order));
+static struct page *buddy_alloc(zone_t *zone, unsigned int order)
+{
+ struct page *page;
+
+ page = dequeue(zone, order);
+
+ /*
+ * This check is incorrect: the lazy buddy invariants may
+ * be satisfied at boot but this would be the case during
+ * steady state.
+ * BUG_ON(!order && !page
+ * && zone->pages_granted - zone->pages_deferred > nr_pages);
+ */
+
+ if (page)
+ LAZY_BUG_ON(PageDeferred(page));
+
+ return page;
+}
+
+static void FASTCALL(split_pages(zone_t *, struct page *, int, int));
+static void split_pages(zone_t *zone,
+ struct page *page,
+ int page_order,
+ int deferred_order)
+{
+ int split_order;
+ unsigned long split_offset;
+ struct page *split_page;
+
+ LAZY_BUG_ON(page_order >= deferred_order || page_order < 0);
+
+ split_order = deferred_order - 1;
+ split_offset = 1UL << split_order;
+ while (split_order >= page_order) {
+
+ LAZY_BUG_ON(split_order < 0 || split_order > MAX_ORDER);
+
+ split_page = &page[split_offset];
+ LAZY_BUG_ON(split_page == page);
+ LAZY_BUG_ON(PageDeferred(split_page));
+ SetPageDeferred(split_page);
+
+ if (unlikely(!test_bit(split_order, &zone->deferred_mask)))
+ __set_bit(split_order, &zone->deferred_mask);
+ else
+ LAZY_BUG_ON(list_empty(&zone->deferred_pages[split_order]));
+ list_add(&split_page->list, &zone->deferred_pages[split_order]);
+
+ --split_order;
+ split_offset >>= 1;
+ }
+}
+
+static FASTCALL(struct page *low_level_alloc(zone_t *, unsigned int));
+static struct page *low_level_alloc(zone_t *zone, unsigned int order)
+{
+ struct page *page;
+ unsigned long nr_pages = 1UL << order;
+ unsigned int deferred_order;
+ unsigned long flags;
+ unsigned long mask;
+
+ spin_lock_irqsave(&zone->lock, flags);
+ check_deferred(zone);
+
+ LAZY_BUG_ON(zone->pages_granted < zone->pages_deferred);
+
+ /*
+ * pages_granted and pages_deferred are about to get further
+ * apart. The only adherence to strict coalescing is during
+ * periods of deferred pool exhaustion.
+ */
+ if (unlikely(zone->pages_granted <= zone->pages_deferred + 2)) {
+ page = buddy_alloc(zone, order);
+ goto out;
+ }
+
+ mask = zone->deferred_mask & ~(nr_pages - 1);
+ if (unlikely(!mask)) {
+ page = buddy_alloc(zone, order);
+ goto out;
+ }
+
+ deferred_order = __ffs(mask);
+ LAZY_BUG_ON(deferred_order >= MAX_ORDER || deferred_order < order);
+
+ LAZY_BUG_ON(list_empty(&zone->deferred_pages[deferred_order]));
+ page = list_entry( zone->deferred_pages[deferred_order].next,
+ struct page,
+ list);
+
+ list_del_init(&page->list);
+ LAZY_BUG_ON(!PageDeferred(page));
+ ClearPageDeferred(page);
+
+ if (unlikely(list_empty(&zone->deferred_pages[deferred_order])))
+ __clear_bit(deferred_order, &zone->deferred_mask);
+ else
+ LAZY_BUG_ON(!test_bit(deferred_order, &zone->deferred_mask));
+
+ LAZY_BUG_ON(zone->pages_deferred < nr_pages);
+ zone->pages_deferred -= nr_pages;
+
+ if (unlikely(deferred_order > order))
+ split_pages(zone, page, order, deferred_order);
+
+out:
+ if (unlikely(!page))
+ goto out_nocount;
+
+ zone->pages_granted += nr_pages;
+ set_page_count(page, 1);
+
+out_nocount:
+ LAZY_BUG_ON(zone->pages_granted < zone->pages_deferred);
+ check_deferred(zone);
+ spin_unlock_irqrestore(&zone->lock, flags);
+ return page;
+}
+
#ifndef CONFIG_DISCONTIGMEM
struct page *_alloc_pages(unsigned int gfp_mask, unsigned int order)
{
@@ -348,8 +649,8 @@
break;
min += z->pages_low;
- if (z->free_pages > min) {
- page = rmqueue(z, order);
+ if (zone_free_pages(z) > min) {
+ page = low_level_alloc(z, order);
if (page)
return page;
}
@@ -372,8 +673,8 @@
if (!(gfp_mask & __GFP_WAIT))
local_min >>= 2;
min += local_min;
- if (z->free_pages > min) {
- page = rmqueue(z, order);
+ if (zone_free_pages(z) > min) {
+ page = low_level_alloc(z, order);
if (page)
return page;
}
@@ -389,7 +690,7 @@
if (!z)
break;
- page = rmqueue(z, order);
+ page = low_level_alloc(z, order);
if (page)
return page;
}
@@ -418,8 +719,8 @@
break;
min += z->pages_min;
- if (z->free_pages > min) {
- page = rmqueue(z, order);
+ if (zone_free_pages(z) > min) {
+ page = low_level_alloc(z, order);
if (page)
return page;
}
@@ -490,15 +791,14 @@
unsigned int nr_free_pages (void)
{
unsigned int sum;
- zone_t *zone;
+ int i;
pg_data_t *pgdat = pgdat_list;
sum = 0;
- while (pgdat) {
- for (zone = pgdat->node_zones; zone < pgdat->node_zones + MAX_NR_ZONES; zone++)
- sum += zone->free_pages;
- pgdat = pgdat->node_next;
- }
+ for (pgdat = pgdat_list; pgdat; pgdat = pgdat->node_next)
+ for (i = 0; i < MAX_NR_ZONES; ++i)
+ sum += zone_free_pages(&pgdat->node_zones[i]);
+
return sum;
}
@@ -574,6 +874,19 @@
return atomic_read(&buffermem_pages);
}
+unsigned long nr_deferred_pages(void)
+{
+ pg_data_t *pgdat;
+ int i;
+ unsigned long pages = 0;
+
+ for (pgdat = pgdat_list; pgdat; pgdat = pgdat->node_next)
+ for (i = 0; i < MAX_NR_ZONES; ++i)
+ pages += pgdat->node_zones[i].pages_deferred;
+
+ return pages;
+}
+
/*
* Accumulate the page_state information across all CPUs.
* The result is unavoidably approximate - it can change
@@ -648,7 +961,7 @@
printk("Zone:%s freepages:%6lukB min:%6lukB low:%6lukB "
"high:%6lukB\n",
zone->name,
- K(zone->free_pages),
+ K(zone_free_pages(zone)),
K(zone->pages_min),
K(zone->pages_low),
K(zone->pages_high));
@@ -858,6 +1171,7 @@
zone->lock = SPIN_LOCK_UNLOCKED;
zone->zone_pgdat = pgdat;
zone->free_pages = 0;
+ zone->pages_deferred = 0;
zone->need_balance = 0;
if (!size)
continue;
@@ -913,6 +1227,7 @@
offset += size;
for (i = 0; ; i++) {
unsigned long bitmap_size;
+ INIT_LIST_HEAD(&zone->deferred_pages[i]);
memlist_init(&zone->free_area[i].free_list);
if (i == MAX_ORDER-1) {
diff -urN --exclude [psx].* linux-2.5/mm/vmscan.c lazy_buddy-2.5/mm/vmscan.c
--- linux-2.5/mm/vmscan.c Tue May 21 08:25:33 2002
+++ lazy_buddy-2.5/mm/vmscan.c Tue May 21 09:03:11 2002
@@ -672,7 +672,7 @@
first_classzone = classzone->zone_pgdat->node_zones;
while (classzone >= first_classzone) {
- if (classzone->free_pages > classzone->pages_high)
+ if (zone_free_pages(classzone) > classzone->pages_high)
return 0;
classzone--;
}
-
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