[PATCH 5/6] mm/page_owner: add zone range overlapping check

[js1304]

From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

There is a system that node's pfn are overlapped like as following.

-----pfn-------->
N0 N1 N2 N0 N1 N2

Therefore, we need to care this overlapping when iterating pfn range.

There are one place in page_owner.c that iterates pfn range and
it doesn't consider this overlapping. Add it.

Without this patch, above system could over count early allocated
page number before page_owner is activated.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
 mm/page_owner.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mm/page_owner.c b/mm/page_owner.c
index ac3d8d1..438768c 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -301,6 +301,9 @@ static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone)
 
 			page = pfn_to_page(pfn);
 
+			if (page_zone(page) != zone)
+				continue;
+
 			/*
 			 * We are safe to check buddy flag and order, because
 			 * this is init stage and only single thread runs.
-- 
1.9.1