Re: [PATCH] hw/arm/virt: Fix CPU's default NUMA node ID

[Andrew Jones]

On Tue, Feb 15, 2022 at 04:19:01PM +0800, Gavin Shan wrote:
> The issue isn't related to CPU topology directly. It's actually related
> to the fact: the default NUMA node ID will be picked for one particular
> CPU if the associated NUMA node ID isn't provided by users explicitly.
> So it's related to the CPU-to-NUMA association.
> 
> For example, the CPU-to-NUMA association is breaking socket boundary
> without the code change included in this patch when the guest is booted
> with the command lines like below. With this patch applied, the CPU-to-NUMA
> association is following socket boundary, to make Linux guest happy.

Gavin,

Please look at Igor's request for more information. Are we sure that a
socket is a NUMA node boundary? Are we sure we can assume an even
distribution for sockets to nodes or nodes to sockets? If so, where is
that documented?

Thanks,
drew