mm: memcontrol: consolidate memory controller initialization

The initialization code for the per-cpu charge stock and the soft
limit tree is compact enough to inline it into mem_cgroup_init().
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Reviewed-by: NVladimir Davydov <vdavydov@parallels.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/memcontrol.c

@@ -2138,17 +2138,6 @@ static void drain_local_stock(struct work_struct *dummy)
 	clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
 }
 
-static void __init memcg_stock_init(void)
-{
-	int cpu;
-
-	for_each_possible_cpu(cpu) {
-		struct memcg_stock_pcp *stock =
-					&per_cpu(memcg_stock, cpu);
-		INIT_WORK(&stock->work, drain_local_stock);
-	}
-}
-
 /*
  * Cache charges(val) to local per_cpu area.
  * This will be consumed by consume_stock() function, later.
@@ -4507,28 +4496,6 @@ struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
 }
 EXPORT_SYMBOL(parent_mem_cgroup);
 
-static void __init mem_cgroup_soft_limit_tree_init(void)
-{
-	int node;
-
-	for_each_node(node) {
-		struct mem_cgroup_tree_per_node *rtpn;
-		int zone;
-
-		rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL,
-				    node_online(node) ? node : NUMA_NO_NODE);
-
-		for (zone = 0; zone < MAX_NR_ZONES; zone++) {
-			struct mem_cgroup_tree_per_zone *rtpz;
-
-			rtpz = &rtpn->rb_tree_per_zone[zone];
-			rtpz->rb_root = RB_ROOT;
-			spin_lock_init(&rtpz->lock);
-		}
-		soft_limit_tree.rb_tree_per_node[node] = rtpn;
-	}
-}
-
 static struct cgroup_subsys_state * __ref
 mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
 {
@@ -5905,10 +5872,33 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage,
  */
 static int __init mem_cgroup_init(void)
 {
+	int cpu, node;
+
 	hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
+
+	for_each_possible_cpu(cpu)
+		INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work,
+			  drain_local_stock);
+
+	for_each_node(node) {
+		struct mem_cgroup_tree_per_node *rtpn;
+		int zone;
+
+		rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL,
+				    node_online(node) ? node : NUMA_NO_NODE);
+
+		for (zone = 0; zone < MAX_NR_ZONES; zone++) {
+			struct mem_cgroup_tree_per_zone *rtpz;
+
+			rtpz = &rtpn->rb_tree_per_zone[zone];
+			rtpz->rb_root = RB_ROOT;
+			spin_lock_init(&rtpz->lock);
+		}
+		soft_limit_tree.rb_tree_per_node[node] = rtpn;
+	}
+
 	enable_swap_cgroup();
-	mem_cgroup_soft_limit_tree_init();
-	memcg_stock_init();
+
 	return 0;
 }
 subsys_initcall(mem_cgroup_init);