Re: SFQ on HFSC leaf does not seem to work

[Eric Dumazet <eric.dumazet@gmail.com>]

Le vendredi 23 décembre 2011 à 10:26 -0500, John A. Sullivan III a
écrit :

> Yes.  This is a problem I have with netem on ingress traffic.  I use the
> filter on ffff: to redirect to ifb0 for the ingress traffic shaping.  I
> cannot figure out a way to redirect a second time to ifb1 for the netem
> qdisc.  I tried putting two action mirred statements in the filter but
> that did not work.  Unlike eth1, I cannot attach a filter further down
> the ifb0 hfsc hierarchy because one can't redirect one ifb into another
> ifb.  Thus, the only way I could figure out how to do inbound netem was
> to replace the terminal qdisc with netem rather than SFQ.  I'd love to
> be able to do that differently.  I tried attaching netem to the SFQ but
> that failed (I assume because SFQ is classless) and I tried the other
> way around, attaching SFQ to netem since you mentioned netem could take
> a class but that did not work either.

Unfortunately, netem wants to control skbs itself, in a fifo queue.

To implement what you want, we would need to setup a second qdisc,
and when packets are dequeued from internal netem fifo, queue them in
second qdisc.