From: Eric Dumazet <eduma...@google.com>
Date: Thu, 11 Apr 2019 05:55:23 -0700
> After commit e21db6f69a95 ("tcp: track total bytes delivered with ECN CE
> marks")
> core TCP stack does a very good job tracking ECN signals.
>
> The "sender's best estimate of CE information" Yuchung mentioned in his
> patch is indeed the best we can do.
>
> DCTCP can use tp->delivered_ce and tp->delivered to not duplicate the logic,
> and use the existing best estimate.
>
> This solves some problems, since current DCTCP logic does not deal with losses
> and/or GRO or ack aggregation very well.
>
> This also removes a dubious use of inet_csk(sk)->icsk_ack.rcv_mss
> (this should have been tp->mss_cache), and a 64 bit divide.
>
> Finally, we can see that the DCTCP logic, calling dctcp_update_alpha() for
> every ACK could be done differently, calling it only once per RTT.
>
> Signed-off-by: Eric Dumazet <eduma...@google.com>
Applied, thanks Eric.
