On Mon, Sep 26, 2016 at 2:47 PM, Aaron Wood <[email protected]> wrote: > Dumb question on this: The tcp_bbr_info struct for a socket can be > inspected at runtime through the ss utility or through a get socket opts > call, right?
Yes, you can use either approach: (1) from code you can use TCP_CC_INFO socket option; there is sample code in the original kernel patch for TCP_CC_INFO: https://patchwork.ozlabs.org/patch/465806/ (2) from ss: if you download and build the net-next branch of the iproute2 package: http://git.kernel.org/cgit/linux/kernel/git/shemminger/iproute2.git/log/?h=net-next then you will get support to print out the main parameters for a BBR connection, eg: The patch with BBR support for ss is here: http://git.kernel.org/cgit/linux/kernel/git/shemminger/iproute2.git/commit/?h=net-next&id=2f0f9aef94129643133363b4503468cdccc481cc As the commit notes, the BBR output looks like: bbr:(bw:1.2Mbps,mrtt:18.965,pacing_gain:2.88672,cwnd_gain:2.88672) Hope that helps, neal > > -Aaron > > On Sat, Sep 17, 2016 at 11:34 AM, Maciej Soltysiak <[email protected]> > wrote: >> >> Hi, >> >> Just saw this: https://patchwork.ozlabs.org/patch/671069/ >> >> Interested to see how BBR would play out with things like fq_codel or >> cake. >> >> "loss-based congestion control is unfortunately out-dated in today's >> networks. On >> today's Internet, loss-based congestion control causes the infamous >> bufferbloat problem" >> >> So, instead of waiting for packet loss they probe and measure, e.g. when >> doing slow start (here called STARTUP) they don't speed up until packet >> loss, but slow down before reaching estimated bandwidth level. >> >> Cake and fq_codel work on all packets and aim to signal packet loss early >> to network stacks by dropping; BBR works on TCP and aims to prevent packet >> loss. >> >> >> 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
