RE: [PATCH v7 0/8] Add support for Sub-NUMA cluster (SNC) systems

From: Luck, Tony
Date: Tue Oct 03 2023 - 12:17:43 EST


> The Sub-NUMA cluster feature on some Intel processors partitions
> the CPUs that share an L3 cache into two or more sets. This plays
> havoc with the Resource Director Technology (RDT) monitoring features.
> Prior to this patch Intel has advised that SNC and RDT are incompatible.
>
> Some of these CPU support an MSR that can partition the RMID
> counters in the same way. This allows for monitoring features
> to be used (with the caveat that memory accesses between different
> SNC NUMA nodes may still not be counted accuratlely.
>
> Note that this patch series improves resctrl reporting considerably
> on systems with SNC enabled, but there will still be some anomalies
> for processes accessing memory from other sub-NUMA nodes.

Bother .. forgot to add the changes since last version summary
to the cover letter. I fixed all the issues called out by Peter Newman
in his review of v6 series. Specific details are included in each patch
(except for patch 0005 which is unchanged).

I added Peter's "Reviewed-by" to patches where he offered it AND
where I didn't make substantive changes (parts 4, 5, 6, 7)

-Tony