On Tue, Nov 05, 2013 at 02:39:28PM +0100, Sebastian Moeller wrote: > Hi Maciej, > > > > On Nov 5, 2013, at 14:22 , Maciej Soltysiak <[email protected]> wrote: > > > Hi list, > > > > 3.12 landed with TSO sizing and FQ scheduler. Is there significant > > benefit of trying to port these to Cero's 3.10 ? > > According to Eric Dumazet, these two help for flows terminating on the > device in question, not for flows just passing through the device. So unless > your cerowrt router offers lots of network services it most likely will not > profit from these features… Also, IIRC, we disable TSO on cerowrt by default > (though TSO sizing might mean that this decision could be revisited). > > >
Of interest in backporting FQ is to be able to analyze its performance on routed streams vs fq_codel. It uses a finer grained FQ, on a 4 tuple, but does not do queue management, so I expect the results will end up looking like SFQ or QFQ with bigger buffers - good fairness but catastrophic effects on fat streams, and a lot more collisions. This is a slide I didn't get to show at ietf, showing what SFQ + longest queue drop looks like. http://snapon.lab.bufferbloat.net/~d/results_3.12/3.12/ecn/rtt_fair_download=5500-upload=20000-noecn-sfq-target=5ms-delay=240ms-2.svg vs fq_codel http://snapon.lab.bufferbloat.net/~d/results_3.12/3.12/ecn/rtt_fair_download=5500-upload=20000-ecn-fq_codel-target=5ms-delay=240ms-2.svg vs pie http://snapon.lab.bufferbloat.net/~d/results_3.12/3.12/ecn/rtt_fair_download=5500-upload=20000-ecn-pie-target=20ms-delay=240ms-2.svg I expect the FQ scheduler to crash a teeny router with its defaults also... Looking at the cpu usage would be interesting too... I'm tempted to backport it, I am! I am! > > I'm assuming we're not going head on to 3.12 for kernel base for cero as of > > yet? > > I would hope for 3.10 to be the kernel for the forceable future, due to > its promised 2 years? maintenance window. I intend to freeze on some variant of 3.10 for quite some time, yes. At the moment I don't really have time to backport the new stuff to cerowrt, I am starting a new job (yea!), and just want to make cero stable ASAP so I can ramp up on that. > > > Best > Sebastian > > > > > Best regards, > > Maciej > > _______________________________________________ > > Cerowrt-devel mailing list > > [email protected] > > https://lists.bufferbloat.net/listinfo/cerowrt-devel > > _______________________________________________ > Cerowrt-devel mailing list > [email protected] > https://lists.bufferbloat.net/listinfo/cerowrt-devel _______________________________________________ Cerowrt-devel mailing list [email protected] https://lists.bufferbloat.net/listinfo/cerowrt-devel
