Re: NUMA problem with AMD G34 system

[Brian Marcotte <marcotte@panix.com>]

> I prepared Xen to handle this situation (nodes without memory)
> before the M-C launch, before that it simply crashed. I agree that
> it is not obvious that you need to populate at least 4 DIMMs per
> CPU.

I suppose that Xen could arrange the cpu to node mapping such that
the memoryless CPUs were assigned to the "nearest" node making it so
you could benefit from the shared L3 cache.

I don't know that it's worth anyone's time though. Perhaps a warning
would suffice?

> Do you have only 4 DIMMs?

Yes, but I don't expect that to last too long. We find that over the
lifetime of a machine, we max out the RAM slots long before we run out
of CPU. The second CPU is mostly just so we can (eventually) fill all
the RAM slots. It's not a problem to run with one CPU for while. I may
also just pin the domains to particular CPU cores rather than pull the
CPU.

Thanks for your help.

--
- Brian