Re: [RFC PATCH 0/3] Add Support for Multiple DC Regions

[<dan.j.williams@intel.com>]

Anisa Su wrote:
[..]
> > Unfortunately none of the details presented in this cover letter really
> > show why the kernel needs this additional complexity.
> > 
> > Can you go into more details on the use cases of multiple partitions?
> > 
> From what I understand, the motivation for DCD as a whole has always been a
> blocker for the entire series. However, this year we've seen multiple vendors
> demo memory pooling/sharing at SC,25[1], as well as the development of a 
> controller that supports "memory pooling and sharing across 
> multiple hosts" from Montage[2].
> 
> The flexibility and control provided by multiple partitions is
> an important capability of DCD for enabling composable memory 
> infrastructures. IMO, adding multi-partition support back in from v8 or
> picking up this patchset would strengthen the series.

Can you explain the use case for multiple partitions per-device?
Describe it in terms of what Linux loses if it never entertains this
aspect of the specification. It significantly complicates the ABI for a
benefit to Linux that I am unable to articulate.