Good performance, though not 10Gbps at small sizes.

New added Netmap extra buffer feature improves performance
significantly because of more pkt slots.

RX only can reach 10Gbps very easy. Fwd needs multiqueue dev
with multithread Click, and better, pinned threads.

4 queues on GPU1 node is best, more queues can downgrade perf,
fewer queues do not hurt very much though.