On Tue, Jul 28, 2015 at 3:09 PM, Juliusz Chroboczek <[email protected]> wrote: > I'm currently away from home, and using a 3G modem for Internet access. > I've found out that both NetworkManager and wvdial/pppd setup the > interface to use pfifo_fast (with a qlen of a mere 3 packets!). Setting > fq_codel manually appears to work fine, but needs to be redone every time > the modem has a hiccup. > > Is that the expected behaviour? Shouldn't we be pushing patches somewhere > to change the default?
1) The ppp driver was debloated by david woodhouse way back when. However, the netusb-related drivers, and the 3g devices themselves, contain oft-huge buffers that reduce the effectiveness of any aqm or fq system, sometimes to immeasurability. I would be very interested in flent benchmarks of your 3g device with the 3 packet txqueue and with fq_codel, for the tcp_upload, rrul, and rrul_be tests. 2) Most advanced qdiscs ignore txqueuelen entirely. 3) Usually you can add a script in /etc/network/ifpreup.d or ifup.d to do extra stuff you want. 4) setting the default qdisc to be fq_codel in the sysctl works on most dynamically created devices, but does not work on devices that come up at boot time before the sysctls have a chance to run and the modprobes to complete. This is why fedora 22, for example, compiled in fq_codel statically, rather than dynamically. > -- Juliusz > _______________________________________________ > Bloat mailing list > [email protected] > https://lists.bufferbloat.net/listinfo/bloat -- Dave Täht worldwide bufferbloat report: http://www.dslreports.com/speedtest/results/bufferbloat And: What will it take to vastly improve wifi for everyone? https://plus.google.com/u/0/explore/makewififast _______________________________________________ Bloat mailing list [email protected] https://lists.bufferbloat.net/listinfo/bloat
