memcg: show reclaim stat

Add the following four fields to memory.stat file:

  - inactive_ratio
  - recent_rotated_anon
  - recent_rotated_file
  - recent_scanned_anon
  - recent_scanned_file

Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: 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>

Documentation/controllers/memory.txt

@@ -289,6 +289,31 @@ will be charged as a new owner of it.
   Because rmdir() moves all pages to parent, some out-of-use page caches can be
   moved to the parent. If you want to avoid that, force_empty will be useful.
 
+5.2 stat file
+  memory.stat file includes following statistics (now)
+	cache			- # of pages from page-cache and shmem.
+	rss			- # of pages from anonymous memory.
+	pgpgin			- # of event of charging
+	pgpgout			- # of event of uncharging
+	active_anon		- # of pages on active lru of anon, shmem.
+	inactive_anon 		- # of pages on active lru of anon, shmem
+	active_file		- # of pages on active lru of file-cache
+	inactive_file		- # of pages on inactive lru of file cache
+	unevictable		- # of pages cannot be reclaimed.(mlocked etc)
+
+	Below is depend on CONFIG_DEBUG_VM.
+	inactive_ratio		- VM inernal parameter. (see mm/page_alloc.c)
+	recent_rotated_anon	- VM internal parameter. (see mm/vmscan.c)
+	recent_rotated_file	- VM internal parameter. (see mm/vmscan.c)
+	recent_scanned_anon 	- VM internal parameter. (see mm/vmscan.c)
+	recent_scanned_file 	- VM internal parameter. (see mm/vmscan.c)
+
+  Memo:
+	recent_rotated means recent frequency of lru rotation.
+	recent_scanned means recent # of scans to lru.
+	showing for better debug please see the code for meanings.
+
+
 6. Hierarchy support
 
 The memory controller supports a deep hierarchy and hierarchical accounting.

mm/memcontrol.c

@@ -1816,6 +1816,36 @@ static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
 		cb->fill(cb, "unevictable", unevictable * PAGE_SIZE);
 
 	}
+
+#ifdef CONFIG_DEBUG_VM
+	cb->fill(cb, "inactive_ratio", mem_cont->inactive_ratio);
+
+	{
+		int nid, zid;
+		struct mem_cgroup_per_zone *mz;
+		unsigned long recent_rotated[2] = {0, 0};
+		unsigned long recent_scanned[2] = {0, 0};
+
+		for_each_online_node(nid)
+			for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+				mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
+
+				recent_rotated[0] +=
+					mz->reclaim_stat.recent_rotated[0];
+				recent_rotated[1] +=
+					mz->reclaim_stat.recent_rotated[1];
+				recent_scanned[0] +=
+					mz->reclaim_stat.recent_scanned[0];
+				recent_scanned[1] +=
+					mz->reclaim_stat.recent_scanned[1];
+			}
+		cb->fill(cb, "recent_rotated_anon", recent_rotated[0]);
+		cb->fill(cb, "recent_rotated_file", recent_rotated[1]);
+		cb->fill(cb, "recent_scanned_anon", recent_scanned[0]);
+		cb->fill(cb, "recent_scanned_file", recent_scanned[1]);
+	}
+#endif
+
 	return 0;
 }