[Cake] Lockup at high speeds

[Georgios Amanakis]

I cannot reproduce this using veth.
I am on latest net-next with upstream-4.18 and running Dave's veth with:
server --- delay --- isp --- mbox --- client

server, delay, isp boxes have noqueue qdiscs.
mbox has cake set at "datacentre" in unlimited mode.
This setup achieves ~12gbit/s in both directions (~24gbit/s total) on
my machine.

Could you share your kernel configuration?

George