commit 2139cbe627b8910ded55148f87ee10f7485408ed
author Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Mon Oct 08 16:32:00 2012 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> Tue Oct 09 16:22:44 2012 +0900
tree e42678cc486717e39391bfc71ca0e5671468210e
parent 770c8aaaf6f04a87e6765f24d497132de9152a46

cma: fix counting of isolated pages

Isolated free pages shouldn't be accounted to NR_FREE_PAGES counter.  Fix
it by properly decreasing/increasing NR_FREE_PAGES counter in
set_migratetype_isolate()/unset_migratetype_isolate() and removing counter
adjustment for isolated pages from free_one_page() and split_free_page().

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3f18a14..d259cc2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -691,7 +691,8 @@
 	zone->pages_scanned = 0;
 
 	__free_one_page(page, zone, order, migratetype);
-	__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
+	if (unlikely(migratetype != MIGRATE_ISOLATE))
+		__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
 	spin_unlock(&zone->lock);
 }
 
@@ -1392,6 +1393,7 @@
 	unsigned int order;
 	unsigned long watermark;
 	struct zone *zone;
+	int mt;
 
 	BUG_ON(!PageBuddy(page));
 
@@ -1407,7 +1409,10 @@
 	list_del(&page->lru);
 	zone->free_area[order].nr_free--;
 	rmv_page_order(page);
-	__mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));
+
+	mt = get_pageblock_migratetype(page);
+	if (unlikely(mt != MIGRATE_ISOLATE))
+		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));
 
 	if (alloc_order != order)
 		expand(zone, page, alloc_order, order,