On Tue 20-09-11 10:58:11, Johannes Weiner wrote:

quoted

On Mon, Sep 19, 2011 at 04:29:55PM +0200, Michal Hocko wrote:

quoted

On Mon 12-09-11 12:57:20, Johannes Weiner wrote:

quoted

@@ -2390,6 +2413,18 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
 }
 #endif
 
+static void age_active_anon(struct zone *zone, struct scan_control *sc,
+			    int priority)
+{
+	struct mem_cgroup_zone mz = {
+		.mem_cgroup = NULL,
+		.zone = zone,
+	};
+
+	if (inactive_anon_is_low(&mz))
+		shrink_active_list(SWAP_CLUSTER_MAX, &mz, sc, priority, 0);
+}
+

I do not like this very much because we are using a similar construct in
shrink_mem_cgroup_zone so we are duplicating that code. 
What about adding age_mem_cgroup_active_anon (something like shrink_zone).

I am not sure I follow and I don't see what could be shared between
the zone shrinking and this as there are different exit conditions to
the hierarchy walk.  Can you elaborate?

Sorry for not being clear enough. Maybe it is not very much important
but what about something like:

Index: linus_tree/mm/vmscan.c
===================================================================

--- linus_tree.orig/mm/vmscan.c	2011-09-20 11:07:57.000000000 +0200
+++ linus_tree/mm/vmscan.c	2011-09-20 11:12:53.000000000 +0200

@@ -2041,6 +2041,13 @@ static inline bool should_continue_recla
 	}
 }
 
+static void age_mem_cgroup_active_anon(struct mem_cgroup_zone *mz,
+		struct scan_control *sc, int priority)
+{
+	if (inactive_anon_is_low(mz))
+		shrink_active_list(SWAP_CLUSTER_MAX, mz, sc, priority, 0);
+}
+
 /*
  * This is a basic per-zone page freer.  Used by both kswapd and direct reclaim.
  */

@@ -2090,8 +2097,7 @@ restart:
 	 * Even if we did not try to evict anon pages at all, we want to
 	 * rebalance the anon lru active/inactive ratio.
 	 */
-	if (inactive_anon_is_low(mz))
-		shrink_active_list(SWAP_CLUSTER_MAX, mz, sc, priority, 0);
+	age_mem_cgroup_active_anon(mz, sc, priority);
 
 	/* reclaim/compaction might need reclaim to continue */
 	if (should_continue_reclaim(mz, nr_reclaimed,

@@ -2421,8 +2427,7 @@ static void age_active_anon(struct zone
 		.zone = zone,
 	};
 
-	if (inactive_anon_is_low(&mz))
-		shrink_active_list(SWAP_CLUSTER_MAX, &mz, sc, priority, 0);
+	age_mem_cgroup_active_anon(&mz, sc, priority);
 }