page allocator: update NR_FREE_PAGES only as necessary
When pages are being freed to the buddy allocator, the zone NR_FREE_PAGES
counter must be updated. In the case of bulk per-cpu page freeing, it's
updated once per page. This retouches cache lines more than necessary.
Update the counters one per per-cpu bulk free.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index abe2600..d56e377 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -456,7 +456,6 @@
int migratetype)
{
unsigned long page_idx;
- int order_size = 1 << order;
if (unlikely(PageCompound(page)))
if (unlikely(destroy_compound_page(page, order)))
@@ -466,10 +465,9 @@
page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
- VM_BUG_ON(page_idx & (order_size - 1));
+ VM_BUG_ON(page_idx & ((1 << order) - 1));
VM_BUG_ON(bad_range(zone, page));
- __mod_zone_page_state(zone, NR_FREE_PAGES, order_size);
while (order < MAX_ORDER-1) {
unsigned long combined_idx;
struct page *buddy;
@@ -524,6 +522,8 @@
spin_lock(&zone->lock);
zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
zone->pages_scanned = 0;
+
+ __mod_zone_page_state(zone, NR_FREE_PAGES, count << order);
while (count--) {
struct page *page;
@@ -542,6 +542,8 @@
spin_lock(&zone->lock);
zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE);
zone->pages_scanned = 0;
+
+ __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
__free_one_page(page, zone, order, migratetype);
spin_unlock(&zone->lock);
}
@@ -686,7 +688,6 @@
list_del(&page->lru);
rmv_page_order(page);
area->nr_free--;
- __mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order));
expand(zone, page, order, current_order, area, migratetype);
return page;
}
@@ -826,8 +827,6 @@
/* Remove the page from the freelists */
list_del(&page->lru);
rmv_page_order(page);
- __mod_zone_page_state(zone, NR_FREE_PAGES,
- -(1UL << order));
if (current_order == pageblock_order)
set_pageblock_migratetype(page,
@@ -900,6 +899,7 @@
set_page_private(page, migratetype);
list = &page->lru;
}
+ __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
spin_unlock(&zone->lock);
return i;
}
@@ -1129,6 +1129,7 @@
} else {
spin_lock_irqsave(&zone->lock, flags);
page = __rmqueue(zone, order, migratetype);
+ __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
spin_unlock(&zone->lock);
if (!page)
goto failed;
