From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

Define function for calculating mapped_ratio in memory cgroup.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Menage <menage@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/memcontrol.h |   11 ++++++++++-
 mm/memcontrol.c            |   17 +++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff -puN include/linux/memcontrol.h~per-zone-and-reclaim-enhancements-for-memory-controller-take-3-calculate-mapper_ratio-per-cgroup include/linux/memcontrol.h
--- a/include/linux/memcontrol.h~per-zone-and-reclaim-enhancements-for-memory-controller-take-3-calculate-mapper_ratio-per-cgroup
+++ a/include/linux/memcontrol.h
@@ -61,6 +61,12 @@ extern int mem_cgroup_prepare_migration(
 extern void mem_cgroup_end_migration(struct page *page);
 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);
+
+
 #else /* CONFIG_CGROUP_MEM_CONT */
 static inline void mm_init_cgroup(struct mm_struct *mm,
 					struct task_struct *p)
@@ -132,7 +138,10 @@ mem_cgroup_page_migration(struct page *p
 {
 }
 
-
+static inline int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
+{
+	return 0;
+}
 #endif /* CONFIG_CGROUP_MEM_CONT */
 
 #endif /* _LINUX_MEMCONTROL_H */
diff -puN mm/memcontrol.c~per-zone-and-reclaim-enhancements-for-memory-controller-take-3-calculate-mapper_ratio-per-cgroup mm/memcontrol.c
--- a/mm/memcontrol.c~per-zone-and-reclaim-enhancements-for-memory-controller-take-3-calculate-mapper_ratio-per-cgroup
+++ a/mm/memcontrol.c
@@ -421,6 +421,23 @@ void mem_cgroup_move_lists(struct page_c
 	spin_unlock(&mem->lru_lock);
 }
 
+/*
+ * Calculate mapped_ratio under memory controller. This will be used in
+ * vmscan.c for deteremining we have to reclaim mapped pages.
+ */
+int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
+{
+	long total, rss;
+
+	/*
+	 * usage is recorded in bytes. But, here, we assume the number of
+	 * physical pages can be represented by "long" on any arch.
+	 */
+	total = (long) (mem->res.usage >> PAGE_SHIFT) + 1L;
+	rss = (long)mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
+	return (int)((rss * 100L) / total);
+}
+
 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
 					struct list_head *dst,
 					unsigned long *scanned, int order,
_