[PATCH v2 03/13] memcg: Uncharge all kmem when deleting a cgroup.

@@ -382,6 +382,7 @@ static void mem_cgroup_get(struct mem_cgroup *memcg);
 static void mem_cgroup_put(struct mem_cgroup *memcg);
 static void memcg_kmem_init(struct mem_cgroup *memcg,
     struct mem_cgroup *parent);
+static void memcg_kmem_move(struct mem_cgroup *memcg);
 
 static inline bool
 mem_cgroup_test_flag(const struct mem_cgroup *memcg, enum memcg_flags flag)

@@ -3700,6 +3701,7 @@ static int mem_cgroup_force_empty(struct mem_cgroup *memcg, bool free_all)
 	int ret;
 	int node, zid, shrink;
 	int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
+	unsigned long usage;
 	struct cgroup *cgrp = memcg->css.cgroup;
 
 	css_get(&memcg->css);

@@ -3719,6 +3721,8 @@ move_account:
 		/* This is for making all *used* pages to be on LRU. */
 		lru_add_drain_all();
 		drain_all_stock_sync(memcg);
+		if (!free_all)
+			memcg_kmem_move(memcg);
 		ret = 0;
 		mem_cgroup_start_move(memcg);
 		for_each_node_state(node, N_HIGH_MEMORY) {

@@ -3740,8 +3744,14 @@ move_account:
 		if (ret == -ENOMEM)
 			goto try_to_free;
 		cond_resched();
+		usage = memcg->res.usage;
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+		if (free_all && !mem_cgroup_test_flag(memcg,
+		    MEMCG_INDEPENDENT_KMEM_LIMIT))
+			usage -= memcg->kmem.usage;
+#endif
 	/* "ret" should also be checked to ensure all lists are empty. */
-	} while (memcg->res.usage > 0 || ret);
+	} while (usage > 0 || ret);
 out:
 	css_put(&memcg->css);
 	return ret;

@@ -5689,9 +5699,28 @@ memcg_kmem_init(struct mem_cgroup *memcg, struct mem_cgroup *parent)
 		parent_res = &parent->kmem;
 	res_counter_init(&memcg->kmem, parent_res);
 }
+
+static void
+memcg_kmem_move(struct mem_cgroup *memcg)
+{
+	unsigned long flags;
+	long kmem;
+
+	spin_lock_irqsave(&memcg->kmem.lock, flags);
+	kmem = memcg->kmem.usage;
+	res_counter_uncharge_locked(&memcg->kmem, kmem);
+	spin_unlock_irqrestore(&memcg->kmem.lock, flags);
+	if (!mem_cgroup_test_flag(memcg, MEMCG_INDEPENDENT_KMEM_LIMIT))
+		res_counter_uncharge(&memcg->res, kmem);
+}
 #else /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
 static void
 memcg_kmem_init(struct mem_cgroup *memcg, struct mem_cgroup *parent)
 {
 }
+
+static void
+memcg_kmem_move(struct mem_cgroup *memcg)
+{
+}
 #endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */