[Cake] cakemq V further thoughts

[Dave Taht]

I continue to revise and edit this piece.

https://docs.google.com/document/d/1tTYBPeaRdCO9AGTGQCpoiuLORQzN_bG3TAkEolJPh28/edit

Today I came up with two other possible objectives to tackle, so
instead of re-re-re-re-rereading the above, they are:

BANG mode - there are certain cases where it it known that the
bandwidth is going to drop significantly (examples include a cnwave to
5ghz backup transition and Starlinks’15s update cycle) where it makes
sense to drop a bunch of packets immediately rather than wait for the
shift to gradually be seen.

tc qdisc change dev eth0 root cake bandwidth <newbandwidth> bang

Cake-autorate rework - the first attempt at doing this directly in
cake frankly… does not work well. There has been a lot of innovation
in the sqm-autorate and cake-autorate projects, which live in
userspace today that might be applied more directly. BANG mode, above,
is an untried inspiration to cake autorate, and would also cope with
L4S flows by doing drops on big rate changes, rather than marks.


-- 
Oct 30: https://netdevconf.info/0x17/news/the-maestro-and-the-music-bof.html
Dave Täht CSO, LibreQos