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Commit 5a6dd343 authored by Glauber Costa's avatar Glauber Costa Committed by David S. Miller
Browse files

Display current tcp memory allocation in kmem cgroup 



This patch introduces kmem.tcp.usage_in_bytes file, living in the
kmem_cgroup filesystem. It is a simple read-only file that displays the
amount of kernel memory currently consumed by the cgroup.

Signed-off-by: default avatarGlauber Costa <glommer@parallels.com>
Reviewed-by: default avatarHiroyouki Kamezawa <kamezawa.hiroyu@jp.fujitsu.com>
CC: David S. Miller <davem@davemloft.net>
CC: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3aaabe23

Documentation/cgroups/memory.txt

+1 −0
Original line number Diff line number Diff line
@@ -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

net/ipv4/tcp_memcontrol.c

+21 −0
Original line number Diff line number Diff line
@@ -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();

	}