Re: [RFC PATCH] net, mm: account sock objects to kmemcg

[Eric Dumazet]

On 06/27/2018 01:41 PM, Shakeel Butt wrote:
> Currently the kernel accounts the memory for network traffic through
> mem_cgroup_[un]charge_skmem() interface. However the memory accounted
> only includes the truesize of sk_buff which does not include the size of
> sock objects. In our production environment, with opt-out kmem
> accounting, the sock kmem caches (TCP[v6], UDP[v6], RAW[v6], UNIX) are
> among the top most charged kmem caches and consume a significant amount
> of memory which can not be left as system overhead. So, this patch
> converts the kmem caches of more important sock objects to SLAB_ACCOUNT.
> 
> Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
> ---
>  net/ipv4/raw.c      | 1 +
>  net/ipv4/tcp_ipv4.c | 2 +-
>  net/ipv4/udp.c      | 1 +
>  net/ipv6/raw.c      | 1 +
>  net/ipv6/tcp_ipv6.c | 2 +-
>  net/ipv6/udp.c      | 1 +
>  net/unix/af_unix.c  | 1 +
>  7 files changed, 7 insertions(+), 2 deletions(-)


Hey, you just disclosed we do not use DCCP ;)

Joke aside, what about simply factorizing this stuff ?

diff --git a/net/core/sock.c b/net/core/sock.c
index bcc41829a16d50714bdd3c25c976c0b7296fab84..b6714f8d7e9ba313723a6f619799c56230ff5fd4 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -3243,7 +3243,8 @@ static int req_prot_init(const struct proto *prot)
 
        rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
                                           rsk_prot->obj_size, 0,
-                                          prot->slab_flags, NULL);
+                                          SLAB_ACCOUNT | prot->slab_flags,
+                                          NULL);
 
        if (!rsk_prot->slab) {
                pr_crit("%s: Can't create request sock SLAB cache!\n",
@@ -3258,7 +3259,8 @@ int proto_register(struct proto *prot, int alloc_slab)
        if (alloc_slab) {
                prot->slab = kmem_cache_create_usercopy(prot->name,
                                        prot->obj_size, 0,
-                                       SLAB_HWCACHE_ALIGN | prot->slab_flags,
+                                       SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
+                                       prot->slab_flags,
                                        prot->useroffset, prot->usersize,
                                        NULL);