net: tcp_memcontrol: protect all tcp_memcontrol calls by jump-label

Move the jump-label from sock_update_memcg() and sock_release_memcg() to
the callsite, and so eliminate those function calls when socket
accounting is not enabled.

This also eliminates the need for dummy functions because the calls will
be optimized away if the Kconfig options are not enabled.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 65947c1f4733..eb39e02899e5 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1818,7 +1818,9 @@ void tcp_v4_destroy_sock(struct sock *sk)
         tcp_saved_syn_free(tp);
 
         sk_sockets_allocated_dec(sk);
-        sock_release_memcg(sk);
+
+        if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
+                sock_release_memcg(sk);
 }
 EXPORT_SYMBOL(tcp_v4_destroy_sock);