[PATCH 07/11] Powerpc/numa: Detect support for coregroup

[Srikar Dronamraju]

* Michael Ellerman <mpe at ellerman.id.au> [2020-07-20 23:56:19]:

> Srikar Dronamraju <srikar at linux.vnet.ibm.com> writes:
> 
> > Add support for grouping cores based on the device-tree classification.
> > - The last domain in the associativity domains always refers to the
> > core.
> > - If primary reference domain happens to be the penultimate domain in
> > the associativity domains device-tree property, then there are no
> > coregroups. However if its not a penultimate domain, then there are
> > coregroups. There can be more than one coregroup. For now we would be
> > interested in the last or the smallest coregroups.
> 
> Should I know what a "coregroup" is? It's not a term I'm familiar with.
> 

Coregroup is a group or subset of cores from the same chip/DIE that share
some resources. This is very similar to MC domain aka Multi-Core Cache (MC),
(kernel/sched/topology.c) where cores share the same cache. In the
Multi-Core Cache domain, all the cores of that domain share the last level
of cache.

Will add the description to the commit message.

> When you repost can you expand the Cc list to include lkml and
> scheduler/topology folks please.
> 

Okay, will add them, I shall copy to LKML, Peter Zijlstra and Ingo Molnar.
Do let me know if you want anyone else to added.

> cheers

-- 
Thanks and Regards
Srikar Dronamraju