2 files changed, 22 insertions, 0 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 085cdcd817b0..bb9c079eeb0c 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -68,6 +68,8 @@ extern void mem_cgroup_page_migration(struct page *page, struct page *newpage);
  * For memory reclaim.
  */
 extern int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem);
+extern long mem_cgroup_reclaim_imbalance(struct mem_cgroup *mem);
+
 
 
 #else /* CONFIG_CGROUP_MEM_CONT */
@@ -145,6 +147,12 @@ static inline int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
 {
         return 0;
 }
+
+static inline int mem_cgroup_reclaim_imbalance(struct mem_cgroup *mem)
+{
+        return 0;
+}
+
 #endif /* CONFIG_CGROUP_MEM_CONT */
 
 #endif /* _LINUX_MEMCONTROL_H */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 2ef214ed5cf8..78a928d90267 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -436,6 +436,20 @@ int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
         rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
         return (int)((rss * 100L) / total);
 }
+/*
+ * This function is called from vmscan.c. In page reclaiming loop. balance
+ * between active and inactive list is calculated. For memory controller
+ * page reclaiming, we should use using mem_cgroup's imbalance rather than
+ * zone's global lru imbalance.
+ */
+long mem_cgroup_reclaim_imbalance(struct mem_cgroup *mem)
+{
+        unsigned long active, inactive;
+        /* active and inactive are the number of pages. 'long' is ok.*/
+        active = mem_cgroup_get_all_zonestat(mem, MEM_CGROUP_ZSTAT_ACTIVE);
+        inactive = mem_cgroup_get_all_zonestat(mem, MEM_CGROUP_ZSTAT_INACTIVE);
+        return (long) (active / (inactive + 1));
+}
 
 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
                                         struct list_head *dst,