2 files changed, 22 insertions, 0 deletions

diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
index 1c9779a74a25..6922b6cb58e3 100644
--- a/Documentation/cgroups/memory.txt
+++ b/Documentation/cgroups/memory.txt
@@ -79,6 +79,7 @@ Brief summary of control files.
  memory.independent_kmem_limit   # select whether or not kernel memory limits are
                                    independent of user limits
  memory.kmem.tcp.limit_in_bytes  # set/show hard limit for tcp buf memory
+ memory.kmem.tcp.usage_in_bytes  # show current tcp buf memory allocation
 
 1. History
 
diff --git a/net/ipv4/tcp_memcontrol.c b/net/ipv4/tcp_memcontrol.c
index e3533903409d..9481f235803e 100644
--- a/net/ipv4/tcp_memcontrol.c
+++ b/net/ipv4/tcp_memcontrol.c
@@ -17,6 +17,11 @@ static struct cftype tcp_files[] = {
                 .read_u64 = tcp_cgroup_read,
                 .private = RES_LIMIT,
         },
+        {
+                .name = "kmem.tcp.usage_in_bytes",
+                .read_u64 = tcp_cgroup_read,
+                .private = RES_USAGE,
+        },
 };
 
 static inline struct tcp_memcontrol *tcp_from_cgproto(struct cg_proto *cg_proto)
@@ -167,6 +172,19 @@ static u64 tcp_read_stat(struct mem_cgroup *memcg, int type, u64 default_val)
         return res_counter_read_u64(&tcp->tcp_memory_allocated, type);
 }
 
+static u64 tcp_read_usage(struct mem_cgroup *memcg)
+{
+        struct tcp_memcontrol *tcp;
+        struct cg_proto *cg_proto;
+
+        cg_proto = tcp_prot.proto_cgroup(memcg);
+        if (!cg_proto)
+                return atomic_long_read(&tcp_memory_allocated) << PAGE_SHIFT;
+
+        tcp = tcp_from_cgproto(cg_proto);
+        return res_counter_read_u64(&tcp->tcp_memory_allocated, RES_USAGE);
+}
+
 static u64 tcp_cgroup_read(struct cgroup *cont, struct cftype *cft)
 {
         struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
@@ -176,6 +194,9 @@ static u64 tcp_cgroup_read(struct cgroup *cont, struct cftype *cft)
         case RES_LIMIT:
                 val = tcp_read_stat(memcg, RES_LIMIT, RESOURCE_MAX);
                 break;
+        case RES_USAGE:
+                val = tcp_read_usage(memcg);
+                break;
         default:
                 BUG();
         }