On Wed, 7 Jan 2026 15:33:53 -0800 Cong Wang wrote:

quoted

It is worth testing for the case where netem is used as a leaf qdisc.
I worry that this could cause the parent qdisc to get accounting wrong.
I.e if HTB calls netem and netem queues 2 packets, the qlen in HTB
would be incorrect.  

In patch 6/8, I added "Test PRIO with NETEM duplication", which installs
netem Qdisc as a child and leaf of root prio qdisc.

Or am I misunderstanding it?

Does something automatically validates that backlog is 0 when qdisc is
destroyed? The test itself only checks:

  "matchPattern": "Sent \\d+ bytes (\\d+) pkt",