per-zone and reclaim enhancements for memory controller: calculate mapper_ratio per cgroup

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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 17 insertions, 0 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1637575d3339..2ef214ed5cf8 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -420,6 +420,23 @@ void mem_cgroup_move_lists(struct page_cgroup *pc, bool active)
         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,