On Aug 22, 2018, at 11:37 AM, Toke Høiland-Jørgensen <toke@toke.dk> wrote:

Pete Heist <pete@heistp.net> writes:

On Aug 22, 2018, at 8:17 AM, Jonathan Morton <chromatix99@gmail.com> wrote:

One difference between fq_codel and Cake is that the former - which
has no shaper - will "bypass" packets when it's empty and there's no
back-pressure filling it. In that case no packet classification
occurs and filters will not be called. Or at least, that's how it
used to be set up; I haven't looked at it recently. Cake does not
rely on the same set of assumptions, so will always call the filter.

Aha, that sounds likely, I’ll try with htb and a rate limit. Testing
with fq_codel was challenging as I had to “do stuff” until my printk’s
were eventually called, but it’s easier now that I can use cake. I
suppose in my case fq_codel’s behavior would be ok in production,
because if there’s no queue then there’s no need to classify. Maybe in
some other cases (like gathering stats), it could be problematic.

fq_codel turns off the bypass capability if you attach a tc filter to
it, though, so if the issue you're seeing is that you filter function is
not being called, that sounds... strange...

How do you check if the function is being called?