[Bloat] CAKE in openwrt high CPU

[Toke Høiland-Jørgensen]

Mikael Abrahamsson <swmike at swm.pp.se> writes:

> On Mon, 31 Aug 2020, Toke Høiland-Jørgensen wrote:
>
>> Hmm, you say CAKE and FQ-Codel - so you're not enabling the shaper (that
>> would be FQ-CoDel+HTB)? An exact config might be useful (or just the
>> output of tc -s qdisc).
>
> Yeah, I guess I'm also using HTB to get the 900 megabit/s SQM is looking 
> for.

Ah, right, makes more sense :)

> If I only use FQ_CODEL to get interface speeds my performance is fine.

And what about when you're running CAKE in 'unlimited' mode?

>> If you are indeed not shaping, maybe you're hitting the issue fixed by this commit?
>>
>> https://github.com/dtaht/sch_cake/commit/3152477235c934022049fcddc063c45d37ec10e6n
>
> I enabled it just now to get the config.
>
> qdisc cake 8030: dev eth0 root refcnt 9 bandwidth 900Mbit besteffort 
> triple-isolate nonat nowash no-ack-filter split-gso rtt 100.0ms raw 
> overhead 0

Hmm, right, you could try no-split-gso as an option as well; you're
pretty close to the point where we turn it off by default, and you're
getting pretty large packets (max_len), so your performance may be
suffering from the splitting...

-Toke