Re: [PATCH v6 01/13] mm/demotion: Add support for explicit memory tiers

Johannes Weiner
2022-06-13T15:41:34Z

On Mon, Jun 13, 2022 at 01:30:08PM +0800, Ying Huang wrote:
> On Mon, 2022-06-13 at 09:01 +0530, Aneesh Kumar K V wrote:
> > On 6/13/22 8:52 AM, Ying Huang wrote:
> > > On Fri, 2022-06-10 at 19:22 +0530, Aneesh Kumar K.V wrote:
> > > > +config TIERED_MEMORY
> > > > + def_bool NUMA
> > > > +
> > >
> > > As Yang pointed out, why not just use CONFIG_NUMA? I suspect the
> > > added value of CONIFIG_TIRED_MEMORY.
> >
> > I decided to use TIERED_MEMORY to bring more clarity. It should be same
> > now that we have moved CONFIG_MIGRATION dependencies to runtime. IMHO
> > having CONFIG_TIERED_MEMORY is better than using CONFIG_NUMA.
>
> I don't think CONFIG_TIERED_MEMORY bring no much value. It's better
> to use CONFIG_NUMA directly. But this is just my opinion.

I agree. As long as it's always built with CONFIG_NUMA, it's simply
NUMA code. Easy enough to modularize it later if somebody really wants
this to be configurable separately.