There was a very good paper or two (I think luca co-authored one) that showed that "active flows" were generally measured in the mid 200s in nearly any scenario. I agreed with that which was in part why I felt we could stick with 1024 queues, a direct mapped hash, and a couple collisions.
cake can falsify that conclusion, or not - at least with ecn enabled, it does falsify it. I think. Can't remember the paper's name.... whether or not accepting 3x more delay as in this case is good, well... more measurements await via https://www.bufferbloat.net/projects/ecn-sane/wiki/ and the ecn-sane mailing list is now active. My original cake code dropped ecn on overload. I tended to think a little ecn a good thing. On Thu, Sep 6, 2018 at 10:10 AM Pete Heist <[email protected]> wrote: > > Interesting, sounds like a good data point for the ECN debate. I wonder if > that pathology happens at lower flow counts. > > I’ve been getting into FreeNet’s backhaul. Four of their backhaul links, the > orange lines in the following map, are licensed spectrum full-duplex 100Mbit > wireless links (not sure what tech, I’ll ask). I’ve so far not witnessed any > bloat in these links because they seem to be over-provisioned based on the > rates of the CPE connections, although that may change as AC is increasingly > deployed. > > http://mapa.czfree.net/#lat=50.76176199690661&lng=15.06277084350586&zoom=13&autofilter=1&type=satellite&geolocate=98%7C114%7C111%7C117%7C109%7C111%7C118%7C115%7C107%7C97&node=6101&aponly=1&bbonly=1&actlink=1&actnode=1&tilt=0&heading=0&; > > Active flow counts appear to be in the tens sometimes, probably not hundreds > very often, from what I’ve witnessed so far... > > On Aug 30, 2018, at 8:24 PM, Dave Taht <[email protected]> wrote: > > This version does indeed work against net-next. I managed to break > myself because I'd been fiddling with flows 32 in some cases, and my > version > returns ENOTSUPP for that which sqm doesn't catch... and ohhh.... > boy... htb with a 1000 packet fifo buffer fallback... SUCKS! :) > > As for profiling, once again I found myself distracted by the ecn > debate. Fitting ecn 500 flows through a 100mbit bottleneck results in > 1300 packets outstanding > 26 flows that can't start (presumably due to ecn fall back), and > without ecn, 450 packets outstanding 3 flows that can't start. > > On Wed, Aug 29, 2018 at 7:23 AM Dave Taht <[email protected]> wrote: > > > I'm presently compiling against net-next. > On Wed, Aug 29, 2018 at 1:12 AM Pete Heist <[email protected]> wrote: > > > > On Aug 29, 2018, at 3:04 AM, Dave Taht <[email protected]> wrote: > > Anyway, this should be a drop in replacement (presently) for fq_codel, > that compiles out of tree and rips out almost everything I don't like. > > https://github.com/dtaht/fq_codel_fast > > > Cool…I’d give it a quick run but it doesn’t compile for me (attached). Kernel > version? > > I think the tc filter thing really hurt us in cake. > > > It would be interesting to see how much. Jon also expressed concern and I’d > been meaning to try some benchmarks before and after that change… > > > > -- > > 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 > > -- 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
