[PATCH net-next] net: Make account struct net to memcg

[Kirill Tkhai]

The patch adds SLAB_ACCOUNT to flags of net_cachep cache,
which enables accounting of struct net memory to memcg kmem.
Since number of net_namespaces may be significant, user
want to know, how much there were consumed, and control.

Note, that we do not account net_generic to the same memcg,
where net was accounted, moreover, we don't do this at all (*).
We do not want the situation, when single memcg memory deficit
prevents us to register new pernet_operations.

(*)Even despite there is !current process accounting already
available in linux-next. See kmalloc_memcg() there for the details.

Signed-off-by: Kirill Tkhai <ktk...@virtuozzo.com>
---
 net/core/net_namespace.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 690e78c6af45..c340d5cfbdec 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -882,7 +882,7 @@ static int __init net_ns_init(void)
 #ifdef CONFIG_NET_NS
        net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
                                        SMP_CACHE_BYTES,
-                                       SLAB_PANIC, NULL);
+                                       SLAB_PANIC|SLAB_ACCOUNT, NULL);
 
        /* Create workqueue for cleanup */
        netns_wq = create_singlethread_workqueue("netns");