Re: [PATCH -mm] slab: use cgroup ino for naming per memcg caches

Vladimir Davydov
2015-04-08T18:19:11Z

On Wed, Apr 08, 2015 at 08:46:22AM -0500, Christoph Lameter wrote:
> On Wed, 8 Apr 2015, Vladimir Davydov wrote:
>
> > has its own copy of kmem cache. What if we decide to share the same kmem
> > cache among all memory cgroups one day? Of course, this will hardly ever
> > happen, but it is an alternative approach to implementing the same
>
> /sys/kernel/slab already supports the use of symlinks. And both SLAB and
> SLUB do slab merging which means effectively an aliasing of multiple slab
> caches to the same name.

Yeah, I think cache merging is a good argument for grouping memcg caches
under /sys/kernel/slab/<slab-name>/cgroup/. We cannot maintain symlinks
for merged memcg caches, because when a memcg cache is created we do not
have names of caches the new cache is merged with. If memcg caches were
listed under /sys/kernel/slab/ along with global ones, absence of the
symlinks would lead to confusion.

Thanks,
Vladimir