From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yuchung Cheng Subject: [PATCH 0/2 net-next] tcp: do not use RTT from delayed ACKs for min-RTT Date: Wed, 17 Jan 2018 12:10:59 -0800 Message-ID: <20180117201101.14137-1-ycheng@google.com> Cc: netdev@vger.kernel.org, edumazet@google.com, ncardwell@google.com, soheil@google.com, Yuchung Cheng To: davem@davemloft.net Return-path: Received: from mail-pg0-f68.google.com ([74.125.83.68]:34349 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752100AbeAQULP (ORCPT ); Wed, 17 Jan 2018 15:11:15 -0500 Received: by mail-pg0-f68.google.com with SMTP id r19so6170426pgn.1 for ; Wed, 17 Jan 2018 12:11:15 -0800 (PST) Sender: netdev-owner@vger.kernel.org List-ID: This patch set prevents TCP sender from using RTT samples from (suspected) delayed ACKs as the minimum RTT, to avoid unbounded over-estimation of the network path delay. This issue is common when a connection has extended periods of one packet chit-chat beyond the min RTT filter window. The first patch does that for TCP general min RTT estimation. The second patch addresses specifically the BBR congestion control's min RTT filter. Yuchung Cheng (2): tcp: avoid min-RTT overestimation from delayed ACKs tcp: avoid min RTT bloat by skipping RTT from delayed-ACK in BBR include/net/tcp.h | 1 + net/ipv4/tcp_bbr.c | 3 ++- net/ipv4/tcp_input.c | 24 ++++++++++++++++++++++-- 3 files changed, 25 insertions(+), 3 deletions(-) -- 2.16.0.rc1.238.g530d649a79-goog