memcg: add mem_cgroup_zone_nr_pages()

Introduce mem_cgroup_zone_nr_pages().  It is called by zone_nr_pages()
helper function.

This patch doesn't have any behavior change.

Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 14 insertions, 1 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6611328460e9..313247e6c503 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -186,7 +186,6 @@ pcg_default_flags[NR_CHARGE_TYPE] = {
         0, /* FORCE */
 };
 
-
 /* for encoding cft->private value on file */
 #define _MEM                    (0)
 #define _MEMSWAP                (1)
@@ -448,6 +447,17 @@ int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg, struct zone *zone)
         return 0;
 }
 
+unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
+                                       struct zone *zone,
+                                       enum lru_list lru)
+{
+        int nid = zone->zone_pgdat->node_id;
+        int zid = zone_idx(zone);
+        struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
+
+        return MEM_CGROUP_ZSTAT(mz, lru);
+}
+
 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
                                         struct list_head *dst,
                                         unsigned long *scanned, int order,
diff --git a/mm/vmscan.c b/mm/vmscan.c
index b2bc06bffcfb..d958d624d3ae 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -139,6 +139,9 @@ static struct zone_reclaim_stat *get_reclaim_stat(struct zone *zone,
 static unsigned long zone_nr_pages(struct zone *zone, struct scan_control *sc,
                                    enum lru_list lru)
 {
+        if (!scan_global_lru(sc))
+                return mem_cgroup_zone_nr_pages(sc->mem_cgroup, zone, lru);
+
         return zone_page_state(zone, NR_LRU_BASE + lru);
 }