[Bloat] CAKE in openwrt high CPU

[Jonathan Morton]

> On 3 Sep, 2020, at 5:32 pm, Toke Høiland-Jørgensen via Bloat <bloat at lists.bufferbloat.net> wrote:
> 
> Yeah, offloading of some sort is another option, but I consider that
> outside of the "CAKE stays relevant" territory, since that will most
> likely involve an entirely programmable packet scheduler.

Offload of *just* shaping could be valuable in itself at higher rates, when combined with BQL, as it would avoid having to interact with the CPU-side timer infrastructure so much.  It would also not be difficult at all to implement in hardware at line rate, even with overhead compensation.  It's the sort of thing you could sensibly do with 74-series logic and a lookup table in a cheap SRAM, up to millions of PPS, and considerably faster in FPGA or ASIC territory.

I think that's what the questions about combining "unlimited Cake" with some other shaper are angling towards, though I suspect that the way Cake's shaper is integrated is still better than having an external one in software.

With that said, it's also possible that something a bit lighter than Cake might be appropriate at cable speeds.  There is background work in this general area going on, so don't despair.

 - Jonathan Morton