I first saw it on 2.0.29. I don't recall now whether I checked it on
an unpatched 2.0.30; I'll have to recompile and test it further.
> Two notes on this. The 2.0.x TCP goes into slow start when doing
> retransmissions. This is probably a mistake on reflection. Packets
> should only be send one for every ACK received during retransmission.
> Second, if your path is lossy it can be very hard to get out of
> retranmission mode. What tends to happen is that every packet you send
> just after a retransmission also gets lost, and then has to be retransmitted.
> In this way you never get a good time sample, and never get to reset your
> RTO timer. The slow start behavior I mention above probably agravates this.
The patch that I posted essentially disables this slow-start.