cake and its default parameters is designed to run just fine as a default qdisc at whatevr the line rate is in linux. I do it all the time. I find the per host/per flow fq useful, the sane diffserv markings helpful, the gso splitting best for low latency apps like videoconferencing, and the stats often enlightening, and I do wish more folk ran it by default.
however, cake is far more cpu intensive (and slightly more memory intensive) than fq_codel is and given the wide range of hardware debian runs on, I cannot support the idea of it being the default qdisc. I could put up a benchmark or three as to the difference in cpu on the raspberry pi 3 and 4 to illustrate this point. Certainly pfifo_fast must die! Up until last week I thought fq_codel WAS the default in debian (in addition to *wrt,ubuntu/fedora/rhel8, arch and so many others) but hd been fooled by linode supplying their own kernel for everything. I'd of course love to see it built by default (along with sch_fq and fq_codel), and more people just reach for the lovely one liner of tc qdisc add eth0 root cake bandwidth XXX whenever they need to shape something, AND use it at line rate (without the bandwidth param) where they can afford it... but I think the decision tree for a linux default at this point would be fq_codel (for generic workloads) sch fq (for tcp serving workloads) cake (if you can afford it) bfifo pfifo_fast I had a long and (apology, all, oft testy!) debate on the benefits of fq_codel vs pfifo_fast vs sch fq over here, with the most relevant comment here: https://github.com/systemd/systemd/issues/9725#issuecomment-413369212 -- Make Music, Not War Dave Täht CTO, TekLibre, LLC http://www.teklibre.com Tel: 1-831-435-0729
