Resetting qdisc


In an attempt to change the qdisc of a network interface the tc command yields the following output:
# tc qdisc show
RTNETLINK answers: Operation not supported
Dump terminated

This is needed because PYNQ sets the eth0 to use qdisc “mq” by default. I want to change it to the linux default of pfifo_fast. Anyone know how to change this?

PYNQ version: 2.5 (Glasgow)
Linux pynq 4.19.0-xilinx-v2019.1 #1 SMP Thu Oct 3 17:08:03 UTC 2019 aarch64 aarch64 aarch64 GNU/Linux
ZCU104 board

This doesn’t seem like an issue specific to PYNQ. You might be better searching on Ubuntu forums for this.


Thanks for getting back to me!

Only thing I found was here (, and all my efforts seem to be fruitless.

Does PYNQ have CONFIG_NET_SCHED compiled into the kernel? If not, which config file do I edit (the boot folder is empty)?
Or would that mean that I need to recompile the kernel and build a custom image?

You can run

cat /proc/config.gz | gunzip > running.config

on your board and check. I checked my ultra96 image and it looks like:

# CONFIG_NET_SCHED is not set

So you will have to add that CONFIG into your SD build flow somewhere like:

Awesome! Thank you @rock!