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Eric Dumazet authored
After commit e21db6f6 ("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 <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Cc: Florian Westphal <fw@strlen.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Lawrence Brakmo <brakmo@fb.com> Cc: Abdul Kabbani <akabbani@google.com> Acked-by:
Soheil Hassas Yeganeh <soheil@google.com> Acked-by:
Neal Cardwell <ncardwell@google.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
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