ConnectX-5 and raw_ethernet_bw in perftest suite: basic config question

Infrastructure & Networking Switches and Gateways Ethernet Switches
1

In GitHub - linux-rdma/perftest: Infiniband Verbs Performance Tests there’s the raw_ethernet_bw task. My questions are:

  1. Since raw_ethernet_bw is sending raw UDP/TCP packets (not over IB) the MTU size needn’t be restricted to 256/512/1024/2048/4096 which are IB restrictions correct?

  2. I have a ConnectX-5 NIC. So should I be calling, for example, mlx5dv_query_port (/usr/includes/infiniband/mlx5dv.h) to get port info or should I be calling ibv_query_port (/usr/includes/infiniband/verbs.h). Is mlx5dv.h just a helper layer on top of ibverbs?

Since perftest’s config and setup mixes together IB and ethernet, it’s hard to tell what applies for ethernet and what’s ultimately meant for IB only.

2

Hi @7532yahoo,

  1. The packets sent from raw QP should not be > MTU+18 Otherwise, the receiver won’t receive them.
  2. Both API queries should work. If ibv_query_port is enough to get the required data, it is recommended to call it. If you need additional parameters, that are not included in ibv_query_port, you can call mlx5dv_query_port.

Regards,
Chen