[PATCH 1/5 v2] memcg: replace unsigned long by u64 to avoid overflow

[Wanpeng Li <liwp.linux-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Changlog:

V2 -> V1:
* fix zone_page_state()::/include/linux/vmstat.h returns 'unsigned long'

From: Wanpeng Li <liwp-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>

Since the return value variable in mem_cgroup_zone_nr_lru_pages and
mem_cgroup_node_nr_lru_pages functions are u64, so replace the return
value of funtions by u64 to avoid overflow.

Signed-off-by: Wanpeng Li <liwp.linux-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 include/linux/vmstat.h |    2 +-
 mm/memcontrol.c        |    5 ++---
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 65efb92..6a14291 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -106,7 +106,7 @@ static inline unsigned long global_page_state(enum zone_stat_item item)
 	return x;
 }
 
-static inline unsigned long zone_page_state(struct zone *zone,
+static inline u64 zone_page_state(struct zone *zone,
 					enum zone_stat_item item)
 {
 	long x = atomic_long_read(&zone->vm_stat[item]);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index a2677e0..724bd02 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -776,8 +776,7 @@ mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid,
 	return ret;
 }
 
-static unsigned long
-mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
+static u64 mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
 			int nid, unsigned int lru_mask)
 {
 	u64 total = 0;
@@ -790,7 +789,7 @@ mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
 	return total;
 }
 
-static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
+static u64 mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
 			unsigned int lru_mask)
 {
 	int nid;
-- 
1.7.9.5