[RFC][PATCH] memory controller per zone patches take 2 [5/10] calculate active/inactive balance for memory cgroup

[KAMEZAWA Hiroyuki]

Define function for determining active/inactive balance in memory
cgroup.
 * just use res.usage as total value and assumes total = active + inactive.
 * and yes, we can use mem_cgroup_get_all_zonestat(mem, MEM_CGROUP_ZSTAT_ACTIVE)

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>

 include/linux/memcontrol.h |    8 ++++++++
 mm/memcontrol.c            |   16 ++++++++++++++++
 2 files changed, 24 insertions(+)

Index: linux-2.6.24-rc2-mm1/mm/memcontrol.c
===================================================================
--- linux-2.6.24-rc2-mm1.orig/mm/memcontrol.c
+++ linux-2.6.24-rc2-mm1/mm/memcontrol.c
@@ -435,6 +435,22 @@ int mem_cgroup_calc_mapped_ratio(struct 
 	rss = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
 	return (rss * 100) / total;
 }
+/*
+ * Uses mem_cgroup's imbalance instead of zone's lru imbalance.
+ * This will be used for determining whether page out routine try to free
+ * mapped pages or not.
+ */
+int mem_cgroup_reclaim_imbalance(struct mem_cgroup *mem)
+{
+	s64 total, active, inactive;
+
+	/* usage is recorded in bytes */
+	total = mem->res.usage >> PAGE_SHIFT;
+	inactive = mem_cgroup_get_all_zonestat(mem, MEM_CGROUP_ZSTAT_INACTIVE);
+	active = total - inactive;
+
+	return active / (inactive + 1);
+}
 
 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
 					struct list_head *dst,
Index: linux-2.6.24-rc2-mm1/include/linux/memcontrol.h
===================================================================
--- linux-2.6.24-rc2-mm1.orig/include/linux/memcontrol.h
+++ linux-2.6.24-rc2-mm1/include/linux/memcontrol.h
@@ -65,6 +65,8 @@ extern void mem_cgroup_page_migration(st
  * For memory reclaim.
  */
 extern int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem);
+extern int mem_cgroup_reclaim_imbalance(struct mem_cgroup *mem);
+
 
 
 #else /* CONFIG_CGROUP_MEM_CONT */
@@ -142,6 +144,12 @@ static inline int mem_cgroup_calc_mapped
 {
 	return 0;
 }
+
+static inline int mem_cgroup_reclaim_imbalance(struct mem_cgroup *mem)
+{
+	return 0;
+}
+
 #endif /* CONFIG_CGROUP_MEM_CONT */
 
 #endif /* _LINUX_MEMCONTROL_H */