Just when I thought it was safe to flash a router. Honestly. Your email landed not less than 5 seconds after I finished a build.
On Tue, Jun 16, 2015 at 10:49 PM, Jonathan Morton <[email protected]> wrote: > I just put in three quite small tweaks to cake: > > 1) Codel now has a saturating increment for count, rather than a wrapping one. > > 2) The active flow counter is now an atomic-access variable. This is really > just an abundance of caution. It is not clear to me if this is needed, either. > 3) The overload drop routine should now be somewhat more efficient in most > cases, since it iterates over the active flows rather than the entire array. > I haven’t measured how much of a difference it makes in practice, but it > should be positive. I was thinking that tracking the fattest 3 or so flows would suffice, there would be constant overhead in keeping that statistic handy and correct but constant overhead on figuring out where to drop on overload, also. > > Point 1 turns out to matter rather a lot under unresponsive loads, given that > count is only 16 bits. > > The “50 up 1 down asymmetric” test now produces the desired results for the > download stream *without* the need to prioritise the acks; Codel now reaches > a steady-ish state where it drops enough of them to keep everything moving, > and this leaves more bandwidth in the up direction for the 50 streams. > > The version of that test with a prioritised download stream reveals that > quite a lot of drops (as well as marks) are still occurring in the 50 > streams. This, to my mind, is a sign of too much aggression in the switch > from marking to dropping, but I need to work out the numbers to be more > confident about adjusting that. k. What bandwidth? I still disagree with you on count/2 because you are trying to hit the next harmonic, and agree with you that count-1 is unstable, but I will try to get some data instead. > > - Jonathan Morton > > _______________________________________________ > Cake mailing list > [email protected] > https://lists.bufferbloat.net/listinfo/cake -- Dave Täht 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
