From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ADA16C2D0DB for ; Fri, 31 Jan 2020 22:18:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7E4A22082E for ; Fri, 31 Jan 2020 22:18:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Os6JbUIj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726225AbgAaWSG (ORCPT ); Fri, 31 Jan 2020 17:18:06 -0500 Received: from mail-wm1-f68.google.com ([209.85.128.68]:55324 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726202AbgAaWSG (ORCPT ); Fri, 31 Jan 2020 17:18:06 -0500 Received: by mail-wm1-f68.google.com with SMTP id q9so9715376wmj.5; Fri, 31 Jan 2020 14:18:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to; bh=iqoYY1hW3kdx2QTMgrt5T8EFx7fh9shlLkm6TPn+Nq8=; b=Os6JbUIjHXfaXBEu9c9EqSpZ96YN7SS0b3HdKsSGYY07ObLpQBrrdatpCjN2SRobYS 7MNbPX6Xt9WQbnPSQfvz38HRv1y9lt5rAq0ShYXiqbG21WI4+G4UUIGeFtOLuUlaFYI4 lZ3xs5yDj0rFFEIyRzQIOrmksKIDwQtmWnfXsWTk9eeRFjgDhiiJ5ee+8Qe0bs/uD7om P1LcR6U2YTW2pqNX7fTW9PcfWP7XIzww3EOkMcVO2ZDuBdhHBPjcUEWHPv4raZ06YYTr Z5LcE7kYkroOzE8NwasYOmy1MVpEk58WGeTYoDSuG/ObaRNu/BYXbqTm+CyRUbpa4ASc CZVg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to; bh=iqoYY1hW3kdx2QTMgrt5T8EFx7fh9shlLkm6TPn+Nq8=; b=O3hqcCeeSCrtoM4lKFwk2U9HPdjYzf9nIqQ4gAPZMMIEL5JVRrqYTrNaL4uM23+UWX SxUDcDX+GMi71k5FoVpfErYDCFRPGhDQHFXRyR3TamJIsrpuJRCForGXSg7frTGyTi44 v0ghL8VBIv+Ea1bRlOy127dpT6HybXseZcf/0+H8dIQrP61pDyFmUJftS/bOSFPi1ioG 5iSQiJqBuEOZBzhKCEm+bgKpyevv4CGuabU9YxuAQyedHSRh/FvYw8FxKS+oh4Nd0dzJ lOWW1yRN9eQN3nHnhj3pNKQwZEOMWy8sojGcm9/9IV5wnme3QBpXnYjnadJfjHdE4d5Q B5nA== X-Gm-Message-State: APjAAAWZJeir1tgFs8rp7DbFZO0GguK9FP69bk8P1c2E+9WmWFRgQwrf MaqTOFgpryX/Om+mrM+ejy4= X-Google-Smtp-Source: APXvYqwrG3rZV6UDSX/Z7ca/bTaf+lU6ATSKe+xRWTbHjL7pQYUeRdmIBwZo72yMufMP+kIoZzO4hA== X-Received: by 2002:a7b:c416:: with SMTP id k22mr14769649wmi.10.1580509083399; Fri, 31 Jan 2020 14:18:03 -0800 (PST) Received: from localhost.localdomain ([2a02:2450:10d2:194d:bcd7:b36c:40fc:d163]) by smtp.gmail.com with ESMTPSA id g15sm6053391wro.65.2020.01.31.14.18.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 31 Jan 2020 14:18:02 -0800 (PST) From: SeongJae Park To: Neal Cardwell Cc: Eric Dumazet , sjpark@amazon.com, Eric Dumazet , David Miller , shuah@kernel.org, Netdev , linux-kselftest@vger.kernel.org, LKML , sj38.park@gmail.com, aams@amazon.com, SeongJae Park , Yuchung Cheng Subject: Re: Re: [PATCH 2/3] tcp: Reduce SYN resend delay if a suspicous ACK is received Date: Fri, 31 Jan 2020 23:17:55 +0100 Message-Id: <20200131221755.3874-1-sj38.park@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: (raw) Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Fri, 31 Jan 2020 17:11:35 -0500 Neal Cardwell wrote: > On Fri, Jan 31, 2020 at 1:12 PM Eric Dumazet wrote: > > > > > > > > On 1/31/20 7:10 AM, Neal Cardwell wrote: > > > On Fri, Jan 31, 2020 at 7:25 AM wrote: > > >> > > >> From: SeongJae Park > > >> > > >> When closing a connection, the two acks that required to change closing > > >> socket's status to FIN_WAIT_2 and then TIME_WAIT could be processed in > > >> reverse order. This is possible in RSS disabled environments such as a > > >> connection inside a host. [...] > > I looked into fixing this, but my quick reading of the Linux > tcp_rcv_state_process() code is that it should behave correctly and > that a connection in FIN_WAIT_1 that receives a FIN/ACK should move to > TIME_WAIT. > > SeongJae, do you happen to have a tcpdump trace of the problematic > sequence where the "process A" ends up in FIN_WAIT_2 when it should be > in TIME_WAIT? Hi Neal, Yes, I have. You can get it from the previous discussion for this patchset (https://lore.kernel.org/bpf/20200129171403.3926-1-sjpark@amazon.com/). As it also has a reproducer program and how I got the tcpdump trace, I believe you could get your own trace, too. If you have any question or need help, feel free to let me know. :) Thanks, SeongJae Park > > If I have time I will try to construct a packetdrill case to verify > the behavior in this case. > > thanks, > neal > > >