+ page-allocator-fix-zone-statistic-accumulation-on-error-path.patch added to -mm tree

+ page-allocator-fix-zone-statistic-accumulation-on-error-path.patch added to -mm tree

[akpm]

The patch titled
     page allocator: fix zone statistic accumulation on error path
has been added to the -mm tree.  Its filename is
     page-allocator-fix-zone-statistic-accumulation-on-error-path.patch

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------------------------------------------------------
Subject: page allocator: fix zone statistic accumulation on error path
From: Huang Shijie <shijie8@gmail.com>

When the `page' returned by __rmqueue() is NULL, the origin code still
adds -(1 << order) to zone's NR_FREE_PAGES item.

The patch fixes it.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_alloc.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff -puN mm/page_alloc.c~page-allocator-fix-zone-statistic-accumulation-on-error-path mm/page_alloc.c
--- a/mm/page_alloc.c~page-allocator-fix-zone-statistic-accumulation-on-error-path
+++ a/mm/page_alloc.c
@@ -1219,10 +1219,14 @@ again:
 		}
 		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)
+		if (likely(page)) {
+			__mod_zone_page_state(zone, NR_FREE_PAGES,
+						-(1 << order));
+			spin_unlock(&zone->lock);
+		} else {
+			spin_unlock(&zone->lock);
 			goto failed;
+		}
 	}
 
 	__count_zone_vm_events(PGALLOC, zone, 1 << order);
_

Patches currently in -mm which might be from shijie8@gmail.com are

page-allocator-fix-zone-statistic-accumulation-on-error-path.patch