[Cake] Cake not more CPU efficient than HTB+FQ-CoDel (anymore)?

[Toke Høiland-Jørgensen]

Toke Høiland-Jørgensen <toke at toke.dk> writes:

> Jonathan Morton <chromatix99 at gmail.com> writes:
>
>>> On 11 Apr, 2018, at 6:24 pm, Toke Høiland-Jørgensen <toke at toke.dk> wrote:
>>> 
>>> So, um, did we cram so many features into Cake that it no longer uses
>>> less CPU? Can anyone confirm these results?
>>
>> To be sure about this, it seems wise to configure Cake to turn off as
>> many of the new features as possible. That means selecting "besteffort
>> flows nonat" mode at least.
>>
>> I forget whether simplest.qos correctly uses the built-in shaper with
>> Cake, rather than just layering it with HTB as usual. If not, then of
>> course Cake will use more CPU, and we should be grateful that it's by
>> a relatively small margin (maybe 15%).
>
> It is definitely using Cake as the shaper; in besteffort mode, but with
> nat and triple-isolation enabled I think. I'll run another test tomorrow
> with those disabled.
>
>> There's also a minor complication in that Cake and fq_codel behave
>> differently when handed superpackets. A fair comparison requires
>> switching aggregation modes off for both of them.
>
> I *think* offloads were turned off for those tests; but I'll double
> check... Also would be nice to get a measure of the smoothness of the
> shaper; will see if I can't extract that from a pcap file or
> something...

Right, double checked and ran a few more tests. Setting cake to
flowblind mode help somewhat, but HTB/FQ-CoDel still gets higher
throughput. Graph attached.

-Toke


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