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
