On 22 Nov 2019, at 19:50, Ilya Maximets wrote:

On 22.11.2019 18:51, William Tu wrote:
Hi Ilya and Eelco,

Yiyang reports very poor TCP performance on his setup and I can
also reproduce it on my machine. Somehow I think this might be a
kernel issue, but I don't know where to debug this. Need your suggestion
about how to debug.

So the setup is like the system-traffic, creating 2 namespaces and
veth devices and attach to OVS. I do remember to turn off tx offload
and ping, UDP, nc (tcp-mode) works fine.

TCP using iperf drops to 0Mbps after 4 seconds.

The key questions are:
* What is your kernel version?
* Does it work in generic mode?
* Does it work if iperf generates UDP traffic?
  ex. iperf3 -c 10.1.1.1 -t 3600 -u -b 10G/64 -l 1460
* It seems like a ring breakage or a umem memory leak.
  So, what are the afxdp related coverage counters?
* Does OVS forward packets, i.e. if there something received/sent?

Best regards, Ilya Maximets.

This looks very much like the issues we had earlier with tap interfaces, this issue was related to OVS not managing the umem ring correctly (and hence running out of buffers). Guess the coverage counters suggested above should show give you a good starting point for debugging.

//Eelco

_______________________________________________
dev mailing list
d...@openvswitch.org
https://mail.openvswitch.org/mailman/listinfo/ovs-dev

Reply via email to