tcp memory pressure controls

This patch introduces memory pressure controls for the tcp
protocol. It uses the generic socket memory pressure code
introduced in earlier patches, and fills in the
necessary data in cg_proto struct.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujtisu.com>
CC: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 40 insertions, 3 deletions

diff --git a/net/core/sock.c b/net/core/sock.c
index 6a871b8fdd20..5a6a90620656 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -136,6 +136,46 @@
 #include <net/tcp.h>
 #endif
 
+static DEFINE_RWLOCK(proto_list_lock);
+static LIST_HEAD(proto_list);
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+int mem_cgroup_sockets_init(struct cgroup *cgrp, struct cgroup_subsys *ss)
+{
+        struct proto *proto;
+        int ret = 0;
+
+        read_lock(&proto_list_lock);
+        list_for_each_entry(proto, &proto_list, node) {
+                if (proto->init_cgroup) {
+                        ret = proto->init_cgroup(cgrp, ss);
+                        if (ret)
+                                goto out;
+                }
+        }
+
+        read_unlock(&proto_list_lock);
+        return ret;
+out:
+        list_for_each_entry_continue_reverse(proto, &proto_list, node)
+                if (proto->destroy_cgroup)
+                        proto->destroy_cgroup(cgrp, ss);
+        read_unlock(&proto_list_lock);
+        return ret;
+}
+
+void mem_cgroup_sockets_destroy(struct cgroup *cgrp, struct cgroup_subsys *ss)
+{
+        struct proto *proto;
+
+        read_lock(&proto_list_lock);
+        list_for_each_entry_reverse(proto, &proto_list, node)
+                if (proto->destroy_cgroup)
+                        proto->destroy_cgroup(cgrp, ss);
+        read_unlock(&proto_list_lock);
+}
+#endif
+
 /*
  * Each address family might have different locking rules, so we have
  * one slock key per address family:
@@ -2291,9 +2331,6 @@ void sk_common_release(struct sock *sk)
 }
 EXPORT_SYMBOL(sk_common_release);
 
-static DEFINE_RWLOCK(proto_list_lock);
-static LIST_HEAD(proto_list);
-
 #ifdef CONFIG_PROC_FS
 #define PROTO_INUSE_NR  64      /* should be enough for the first time */
 struct prot_inuse {