Re: [PATCH v2] net, mm: account sock objects to kmemcg

[Kirill Tkhai <ktkhai@virtuozzo.com>]

On 28.06.2018 01:16, 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 all sock objects to SLAB_ACCOUNT.
> 
> Signed-off-by: Shakeel Butt <shakeelb@google.com>
> Suggested-by: Eric Dumazet <edumazet@google.com>

Looks good for me.

Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>

> ---
> Changelog since v1:
> - Instead of specific sock kmem_caches, convert all sock kmem_caches to
>   use SLAB_ACCOUNT.
> 
>  net/core/sock.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/net/core/sock.c b/net/core/sock.c
> index bcc41829a16d..9e8f65585b81 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);
>  
> @@ -3281,6 +3283,7 @@ int proto_register(struct proto *prot, int alloc_slab)
>  				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
>  						  prot->twsk_prot->twsk_obj_size,
>  						  0,
> +						  SLAB_ACCOUNT |
>  						  prot->slab_flags,
>  						  NULL);
>  			if (prot->twsk_prot->twsk_slab == NULL)
>