Dave Taht wrote: > In looking over the enormous stack of boards and drivers that openwrt > supports, I see that many of the ethernet drivers don't yet support > Linux 3.3's "Byte Queue Limits", which are discussed here: > > http://lwn.net/Articles/454390/ > > It would be good if more did. They improve network performance in the > general case enormously, particularly when a link is not connected at > it's peak wire speed. > > *Adding* support for BQL to an ethernet driver is trivial, here's an > example of how.
I tried adding BQL to the ramips ethernet driver, however I found some interesting behaviour while doing "root@OpenWrt:~# netperf -l 120 -t UDP_STREAM -H myserver" It looks like the briding code still needs to implement this as well? netperf UDP_STREAM: iface limit_min inflight tx mbps remote mbps ping ms eth0 0 ~15000 95.71 95.71 ~10ms eth0 1000000 ~300000 177.98 23.28(*) ~30ms br0 0 ~15000 154.88 33.94(*) ~120ms br0 1000000 ~300000 170.92 25.57(*) ~30ms (*) bwm-ng on the server showed ~100mbps incoming... It is notable that the internal interface to the cpu is 1000Mbit, while the external interface after the built-in switch is only 100Mbit on this device and the switch can drop packets if the incoming rate is too high. The switch defaults are: Back pressure mode: JAM all until BP condition is released BP_JAM_CNT: 10 (10 packet jam, then one no-jam) It also supports 'carrier insertion' instead of jamming. And there are some flow control threshold values that could be tweaked. Haven't tried codel yet... -- Tobias PGP: http://8ef7ddba.uguu.de _______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
