From: Eric Dumazet <eric.duma...@gmail.com> Date: Fri, 21 Aug 2015 17:38:02 -0700
> From: Eric Dumazet <eduma...@google.com> > > When TCP pacing was added back in linux-3.12, we chose > to apply a fixed ratio of 200 % against current rate, > to allow probing for optimal throughput even during > slow start phase, where cwnd can be doubled every other gRTT. > > At Google, we found it was better applying a different ratio > while in Congestion Avoidance phase. > This ratio was set to 120 %. > > We've used the normal tcp_in_slow_start() helper for a while, > then tuned the condition to select the conservative ratio > as soon as cwnd >= ssthresh/2 : > > - After cwnd reduction, it is safer to ramp up more slowly, > as we approach optimal cwnd. > - Initial ramp up (ssthresh == INFINITY) still allows doubling > cwnd every other RTT. > > Signed-off-by: Eric Dumazet <eduma...@google.com> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
