[Bloat] SFB tuning

[Juliusz Chroboczek]

> Internet (100Mbps ethernet capped to 70Mbps by the ISP):
>
> tc qdisc add dev eth4 parent 1:3  handle 13:  sfb hash-type source limit 100 target 10 max 15 penalty_rate 60
>
> And on the internal interfaces (1Gbps ethernet) to clients like this:
>
> tc qdisc add dev ${DEV} parent 50:20 handle 52: sfb hash-type dest limit 100 target 10 max 15 penalty_rate 100

Looks good to me.

You may want to increase limit and penalty -- remember that these values
are shared between all clients.  (Are you seeing any queuedrop?)

You may also want to experiment with increasing increment/decrement --
increment should be roughly 5 times larger than decrement, and the
values should be as large as you can make them without seeing
oscillations.  (Larger values yield faster convergence, but may cause
overshoot.)

You may also want to encourage your clients to enable ECN.

May I see the output of ``tc -s qdisc show''?

-- Juliusz