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>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index aad9377c9828..b1defd6a2783 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -102,6 +102,9 @@ extern long mem_cgroup_calc_reclaim(struct mem_cgroup *mem, struct zone *zone,
                                         int priority, enum lru_list lru);
 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg,
                                     struct zone *zone);
+unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
+                                       struct zone *zone,
+                                       enum lru_list lru);
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
 extern int do_swap_account;
@@ -260,6 +263,14 @@ mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg, struct zone *zone)
         return 1;
 }
 
+static inline unsigned long
+mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg, struct zone *zone,
+                         enum lru_list lru)
+{
+        return 0;
+}
+
+
 #endif /* CONFIG_CGROUP_MEM_CONT */
 
 #endif /* _LINUX_MEMCONTROL_H */