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

[Gavin Shan]

On 2/15/22 4:32 PM, Andrew Jones wrote:
> 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?

Yes, I was investigating the code for Igor's questions, but I didn't
reach to conclusion when I replied to Yanan. I will reply to Igor's
thread and lets discuss it through over thread.

Thanks,
Gavin