Why NVMe MSIx vectors affinity set across NUMA nodes?

[Sagi Grimberg]

>> application uses libnuma to align to numa locality.
>> here the driver is breaking the affinity.
>> certainly having affinity with remote node cpu will add latency to
>> interrupt response time.
>> here it is for some NVMe queues.
> 
> I bet you can't come up with an IRQ CPU affinity map that performs better
> than the current setup.

:)

While I agree that managed affinity will probably get the optimal
affinitization in 99% of the cases, this is the second complaint we've
had that managed affinity breaks an existing user interface (even though
it was a sure way to allow userspace to screw up for years).

My mlx5 conversion ended up reverted due to that...