+static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg,
+ enum mem_cgroup_stat_index idx)
+{
+ struct mem_cgroup *iter;
+ long val = 0;
+
+ /* Per-cpu values can be negative, use a signed accumulator */
+ for_each_mem_cgroup_tree(iter, memcg)
+ val += mem_cgroup_read_stat(iter, idx);
+
+ if (val < 0) /* race ? */
+ val = 0;
+ return val;
+}
+
+static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
+{
+ u64 val;
+
+ if (!mem_cgroup_is_root(memcg)) {
+ if (!swap)
+ return res_counter_read_u64(&memcg->res, RES_USAGE);
+ else
+ return res_counter_read_u64(&memcg->memsw, RES_USAGE);
+ }
+
+ /*
+ * Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
+ * as well as in MEM_CGROUP_STAT_RSS_HUGE.
+ */
+ val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE);
+ val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS);
+
+ if (swap)
+ val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAP);
+
+ return val << PAGE_SHIFT;
+}
+
+