From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next] tcp: ignore rcv_rtt sample with old ts ecr value Date: Fri, 22 Jun 2018 13:45:51 +0900 (KST) Message-ID: <20180622.134551.258586424493469487.davem@davemloft.net> References: <20180620044250.33943-1-tracywwnj@gmail.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, edumazet@google.com, ncardwell@google.com To: weiwan@google.com Return-path: Received: from shards.monkeyblade.net ([23.128.96.9]:44498 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751010AbeFVEpz (ORCPT ); Fri, 22 Jun 2018 00:45:55 -0400 In-Reply-To: <20180620044250.33943-1-tracywwnj@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Wei Wang Date: Tue, 19 Jun 2018 21:42:50 -0700 > From: Wei Wang > > When receiving multiple packets with the same ts ecr value, only try > to compute rcv_rtt sample with the earliest received packet. > This is because the rcv_rtt calculated by later received packets > could possibly include long idle time or other types of delay. > For example: > (1) server sends last packet of reply with TS val V1 > (2) client ACKs last packet of reply with TS ecr V1 > (3) long idle time passes > (4) client sends next request data packet with TS ecr V1 (again!) > At this time, the rcv_rtt computed on server with TS ecr V1 will be > inflated with the idle time and should get ignored. > > Signed-off-by: Wei Wang > Signed-off-by: Neal Cardwell > Signed-off-by: Eric Dumazet Applied.