Re: [PATCH] mm: provide interface for retrieving kmem_cache name

[Christopher Lameter]

On Fri, 8 Nov 2019, Knut Omang wrote:

> On Fri, 2019-11-08 at 15:37 +0000, Christopher Lameter wrote:
> > On Thu, 7 Nov 2019, Michal Hocko wrote:
> >
> > > On Thu 07-11-19 13:26:09, Knut Omang wrote:
> > > > On Thu, 2019-11-07 at 12:58 +0100, Michal Hocko wrote:
> > > > > On Thu 07-11-19 12:54:04, Knut Omang wrote:
> > > > > > With the restructuring done in commit 9adeaa226988
> > > > > > ("mm, slab: move memcg_cache_params structure to mm/slab.h")
> > > > > >
> > > > > > it is no longer possible for code external to mm to access
> >
> > That patch only affected the memcg_cache_params structure and not
> > kmem_cache.
> >
> > And I do not see any references to the memcg_cache_param?
>
> Good point, I should have made explicit reference to it.
>
> It gets inlined into kmem_cache with CONFIG_SLUB if CONFIG_MEMCG is set
> (include/linux/slub_def.h, line 112)

Yes but that does not affect the "name" field on line 105

> > The fields that all allocators need to expose are listed in
> > the struct kmme_cache definition in linux/mm/slab.h.
>
> So I take that kmem_cache::name was still intended to be public,
> just that that broke due to the inlining of struct memcg_cache_param
> in slub_def.h?

The patch did not change the name field. I am not sure what is broken?

Maybe you need memcg_params to compose a name of the memcg with the slab
name?