poor performances with DPDK on a gcloud VM

[Stephen Hemminger]

On Tue, 21 Jun 2022 17:29:38 +0100
Sylvain Vasseur <remmog at gmail.com> wrote:

> Hello,
> 
> Did someone already manage to use DPDK on a GCP VM and have good
> performances? I am trying this configuration lately, have some awful
> bandwidth results and no idea what I could be doing wrong.
> 
> I use the VirtIO interfaces on my VMs, was able to use both the vfio-pci
> and igb_uio PMD. But can only get ~350Mbps (yes bits!) with both, when
> trying to transmit data with a very basic testpmd run.
> dpdk-testpmd -a 0000:00:05.0 -- --forward-mode=txonly --stats-period 1
> 
> Any non-dpdk use of the network interface gives me way better results
> (GBps!).
> 
> Device:
> 00:05.0 Ethernet controller: Red Hat, Inc. Virtio network device
> 
> Bind status
> Network devices using DPDK-compatible driver
> ============================================
> 0000:00:05.0 'Virtio network device 1000' drv=igb_uio unused=vfio-pci
> 
> I would bet I am doing something wrong, either with the PMD choice, or with
> some setting. But can't figure what. Did anyone manage to have good
> performances or some experience of using DPDK on a google cloud VM?
> 
> Thanks in advance
> Sylvain

Check the negotiation of virtio features and checksum offload bits.