BlueField-3 DOCA PCC: Should PCC bind to SF or PF? How to test custom CC when RDMA traffic uses SF?

Infrastructure & Networking DOCA Getting Started & Resources
1

I’m trying to deploy and test my custom congestion control algorithm on BlueField-3 using DOCA PCC. I can configure IP on a Sub-Function (SF) and run perftest successfully, but I cannot bind PCC to the SF device. PCC only seems to bind to the PF device (e.g., mlx5_0). When I send RDMA traffic via the SF, PCC bound to PF doesn’t appear to take effect.

Here’s my setup and symptoms:

  • SF interface: enp3s0f0s0
  • RDMA traffic: only works via SF (perftest OK)
  • PCC binding: only works via PF (mlx5_0)
  • show_gids output:
DEV     PORT    INDEX   GID                                     IPv4            VER     DEV
---     ----    -----   ---                                     ------------    ---     ---
mlx5_2  1       0       fe80:0000:0000:0000:0039:04ff:fed3:d339                 v2      enp3s0f0s0
mlx5_3  1       0       fe80:0000:0000:0000:0045:19ff:fe2e:0276                 v2      enp3s0f1s0
n_gids_found=2

My questions:

  1. Should DOCA PCC bind to the SF or the PF for traffic that is sent via SF?
  2. If PCC must bind to PF, how can I ensure SF traffic is actually controlled by the PCC algorithm?
  3. What is the correct IP / RDMA device configuration to test a custom PCC algorithm on BF3 when traffic uses SF?

Any guidance on the correct binding model (PF vs SF) and recommended configuration steps would be really helpful.

Thanks in advance!

1 Like
2

I have the exactly same problem. Looking forward to solution.

3

I run the compiled example program doca_pcc and bind PCC to mlx5_0 using the command ./doca_pcc -d mlx5_0, but I can only send RoCE traffic from the SF, which is mlx5_2. I observed that traffic sent from mlx5_2 (perftest) is not controlled by PCC bound to mlx5_0. I would like to know how to properly deploy and test whether the NVIDIA DOCA PCC example code is working correctly.