Next time I have sufficient spare brain cells I would like to try shaping across cores. I don't know how to share a bit of data between qdiscs as yet, so my plan to prove it out, is to use a static variable for time_next_packet (has to be 32 bits also), and atomically update it between the ksoftirq threads on each hardware queue.
https://github.com/dtaht/fq_codel_fast/ Don't know if we can round effectively to ns at 32 bits That would do less work per core with larger intervals between reschedules with sufficient multiplexing. In addition to that problem, shaping inbound across cores is currently serialized to one core (I think) by the sch_ingress qdisc. There was some new work *way* earlier in the path https://lwn.net/Articles/763056/ recently - and to try and find some why to bypass the ingress and mirred portions of the path, and just pull directly from that would help. On Tue, Sep 11, 2018 at 11:29 AM Dave Taht <[email protected]> wrote: > > that was me shaping at 900. > On Tue, Sep 11, 2018 at 11:27 AM Pete Heist <[email protected]> wrote: > > > > > > > On Sep 11, 2018, at 10:20 AM, Dave Taht <[email protected]> wrote: > > > > > > What I "fixed" was on the apu2 with the burst/cburst change, I went > > > from completely bottlenecked on one softirq to having 3 eat cpu, and > > > from 400mbps to 900mbps. Now, that's a quad core and the e1000 (?) > > > driver. The edgerouter X is a dual core, and you did see a small > > > improvement in throughput, but I'd hoped for more. > > > > > > That’s rather dramatic. When you do your tests, do you set the shaper to a > > high number and see how high actual throughput goes, or do you do it some > > other way? Just in case, I tried setting the ER-X to 350Mbit. htb+fq_codel > > topped out at 149Mbit, and with c/burst 96000 186 Mbit, so in both types of > > tests it was about a 25% increase, not small, but unfortunately not 2x! > > > > Pete > > > > > -- > > Dave Täht > CEO, TekLibre, LLC > http://www.teklibre.com > Tel: 1-669-226-2619 -- Dave Täht CEO, TekLibre, LLC http://www.teklibre.com Tel: 1-669-226-2619 _______________________________________________ Cake mailing list [email protected] https://lists.bufferbloat.net/listinfo/cake
