From: Eric Dumazet <[email protected]> Date: Thu, 17 Sep 2015 08:38:00 -0700
> From: Eric Dumazet <[email protected]> > > Tracking idle time in bictcp_cwnd_event() is imprecise, as epoch_start > is normally set at ACK processing time, not at send time. > > Doing a proper fix would need to add an additional state variable, > and does not seem worth the trouble, given CUBIC bug has been there > forever before Jana noticed it. > > Let's simply not set epoch_start in the future, otherwise > bictcp_update() could overflow and CUBIC would again > grow cwnd too fast. > > This was detected thanks to a packetdrill test Neal wrote that was flaky > before applying this fix. > > Fixes: 30927520dbae ("tcp_cubic: better follow cubic curve after idle period") > Signed-off-by: Eric Dumazet <[email protected]> > Signed-off-by: Neal Cardwell <[email protected]> > Signed-off-by: Yuchung Cheng <[email protected]> > Cc: Jana Iyengar <[email protected]> Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
