Re: [PATCH] memcg: account security cred as well to kmemcg

[Chris Down]

Shakeel Butt writes:
> The cred_jar kmem_cache is already memcg accounted in the current
> kernel but cred->security is not. Account cred->security to kmemcg.
>
> Recently we saw high root slab usage on our production and on further
> inspection, we found a buggy application leaking processes. Though that
> buggy application was contained within its memcg but we observe much
> more system memory overhead, couple of GiBs, during that period. This
> overhead can adversely impact the isolation on the system. One of source
> of high overhead, we found was cred->secuity objects.

Makes sense. I took a look through other cred-related allocations to see if any 
others stood out and this looks like it covers all the relevant cases.  
__alloc_file is the only other one that caught my eye, but SLAB_ACCOUNT is on 
the filp cache already.

Thanks :-)

> Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>

Acked-by: Chris Down <chris@xxxxxxxxxxxxxx>