Slow ramp-up for single-stream TCP throughput on 4.2 kernel.

Eric Dumazet eric.dumazet at
Sun Oct 4 10:28:25 PDT 2015

On Sun, 2015-10-04 at 10:05 -0700, Ben Greear wrote:

> I guess I'll just stop using Cubic.  Any suggestions for another
> congestion algorithm to use?  I'd prefer something that worked well
> in pretty much any network condition, of course, and it has to work with
> ath10k.
> We can also run some tests with 1G, 10G, ath10k, ath9k, and in conjunction
> with network emulators and various congestion control algorithms.

You could use cubic , but disable or tune HyStart, which is known to be
problematic anyway.

echo  0 >/sys/module/tcp_cubic/parameters/hystart_detect

Or try

echo 40 >/sys/module/tcp_cubic/parameters/hystart_low_window

More information about the ath10k mailing list