[Devel] Re: [PATCH v3 05/16] consider a memcg parameter in kmem_create_cache

[Michal Hocko]

On Tue 18-09-12 18:11:59, Glauber Costa wrote:
> Allow a memcg parameter to be passed during cache creation.
> When the slub allocator is being used, it will only merge
> caches that belong to the same memcg.
> 
> Default function is created as a wrapper, passing NULL
> to the memcg version. We only merge caches that belong
> to the same memcg.
> 
> From the memcontrol.c side, 3 helper functions are created:
> 
> 1) memcg_css_id: because slub needs a unique cache name
>    for sysfs. Since this is visible, but not the canonical
>    location for slab data, the cache name is not used, the
>    css_id should suffice.
> 
> 2) mem_cgroup_register_cache: is responsible for assigning
>     a unique index to each cache, and other general purpose
>     setup. The index is only assigned for the root caches. All
>     others are assigned index == -1.

It would be nice to describe what is memcg_params.id intended for. There
is no usage in this patch (except for create_unique_id in slub).
I guess that by root caches you mean all default caches with
memcg==NULL, right?

[...]
-- 
Michal Hocko
SUSE Labs