On Mon, Aug 20, 2018 at 01:54:20PM -0700, Sagi Grimberg wrote:

nvme-rdma attempts to map queues based on irq vector affinity.
However, for some devices, completion vector irq affinity is
configurable by the user which can break the existing assumption
that irq vectors are optimally arranged over the host cpu cores.

IFF affinity is configurable we should never use this code,
as it breaks the model entirely.  ib_get_vector_affinity should
never return a valid mask if affinity is configurable.