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

From: Reinette Chatre
Date: Tue Oct 03 2023 - 12:34:23 EST




On 10/3/2023 9:16 AM, Luck, Tony wrote:
>> 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.

The typo that I pointed out in V4 as well as V5 remains.
Not fixing something this fundamental reflects poorly on the rest
of this work.

Reinette