Re: [PATCH v11 7/8] x86/resctrl: Sub NUMA Cluster detection and enable

From: Reinette Chatre
Date: Mon Nov 20 2023 - 17:24:26 EST


Hi Tony,

On 11/9/2023 3:09 PM, Tony Luck wrote:
> There isn't a simple hardware bit that indicates whether a CPU is
> running in Sub NUMA Cluster (SNC) mode. Infer the state by comparing
> the ratio of NUMA nodes to L3 cache instances.
>
> When SNC mode is detected, reconfigure the RMID counters by updating
> the MSR_RMID_SNC_CONFIG MSR on each socket as CPUs are seen.
>
> Clearing bit zero of the MSR divides the RMIDs and renumbers the ones
> on the second SNC node to start from zero.
>
> Reviewed-by: Peter Newman <peternewman@xxxxxxxxxx>
> Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
> ---

(note ordering of commit tags)

Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>

Reinette