Re: [dpdk-users] Which coremask and "-n" (number of mem channels) should be used for a system with only "node1" (no "node0") and 2 sockets ?

[Matthew Hall <mhall@mhcomputing.net>]

On Tue, Aug 16, 2016 at 11:05:26AM -0700, Stephen Hemminger wrote:
> What if you have a two socket machine, and node 0 is not populated?

I did include that possibility. But most NUMA systems I have set up myself 
will not boot if Socket 1 is full and Socket 0 is empty. The early boot code 
generally assumes Socket 0 is valid when first initting itself.

> Also does the kernel have NUMA support enabled?

Good question, the vast majority of standard SMP kernels do have NUMA at this 
point I believe. It would maybe be good to see if the issue went away if the 
machine was intentionally run with a UP kernel.

> Long ago there was a bug in DPDK where it got NUMA socket info from 
> /proc/cpuinfo. On some machines, the 'physical id' starts at 1 because value 
> comes from BIOS.

Ouch... that's very evil of the BIOS. But also sadly not surprising.

Matthew.