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=-2.3 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_SANE_1 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 5D078C4360C for ; Wed, 2 Oct 2019 22:33:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2888121783 for ; Wed, 2 Oct 2019 22:33:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="lTBWj6dw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727766AbfJBWdj (ORCPT ); Wed, 2 Oct 2019 18:33:39 -0400 Received: from mail-pl1-f195.google.com ([209.85.214.195]:44908 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725799AbfJBWdi (ORCPT ); Wed, 2 Oct 2019 18:33:38 -0400 Received: by mail-pl1-f195.google.com with SMTP id q15so507639pll.11 for ; Wed, 02 Oct 2019 15:33:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=seWAXIAs1FPFz6oCMNngh3BtQDrVTkWAqQbHDBoR96c=; b=lTBWj6dwLcb0HK2zVyaTrAGIUis/gVaD8gZvIWeXrVFw2tT6EmwLNMOvMgidEHQoiX O4jxrJffEzzEUkoLnbZJ8F1PQ9HDP/qGvqEM8Yx7CGFNBqPOV4/W8IcF4+8swDcpgZKX oT0xZ/j1rf54N8a6UcxVQPfbLe+6ZBRCaqiPUWswM3eX0RYDA9ucjc+7VqBpybCGeUHM IShh/KSNUm73ghgcSetkqM6aNePsajGXLPX2MMWSO7fUeG4XaHUxBYiFznU/a6xSyeYG M3ohhZGtewp37CFAcjCkbuuwfRY/+5uepJ1iTlTrhDchMCqidaTy7RVsKa7GnuakM91V Rv6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=seWAXIAs1FPFz6oCMNngh3BtQDrVTkWAqQbHDBoR96c=; b=M45kky30wHM6a+cKMbLMnclNRYX4pVnc8yCRxzrPE+DpgcBFHjjBaHoTDumdPo6qq7 wNIzk8QtSYCIDHx0noXBRVX3nh+ghVJUfzVnfYVSN2hC6yBVUuJy5EkmBRRw9mkhCn56 CfCUcMpYyuliIfCDGaJaDNWJSC1UmSDQfOc+UckYLmvow4EPhXMxVIhM4CEIj1o+DumL YJ7sbu+oZz/gny3DhvYQLBMTPlTRzFcLoKm/+LU2UKTPc9xZTS9com2r0/7EEQ0p8YXf GVNimiaTv0mKIJdRO+0dY2ILetL5qTvB/nUd+3Lb7XfpUB5KjX9BUH6wOFeCxa6Ye4ef 9lEQ== X-Gm-Message-State: APjAAAXJ9eTZo621Hw8eJEHNe2FhCl+aeutGkX/Z2cBJTdHqsZ+Ed7hm +tTUsqsUNzIqFEKsl55zup0= X-Google-Smtp-Source: APXvYqyi65331fmthBWrYgaZq5iymY4CrbOIYQwTtu4DXqDnd7I541P0wVjB4PKcDz+jR6lyUx5v4A== X-Received: by 2002:a17:902:bcc4:: with SMTP id o4mr6017957pls.142.1570055618425; Wed, 02 Oct 2019 15:33:38 -0700 (PDT) Received: from ?IPv6:2620:15c:2c1:200:55c7:81e6:c7d8:94b? ([2620:15c:2c1:200:55c7:81e6:c7d8:94b]) by smtp.gmail.com with ESMTPSA id r2sm491785pfq.60.2019.10.02.15.33.37 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 02 Oct 2019 15:33:37 -0700 (PDT) Subject: Re: [PATCH] tcp: add tsval and tsecr to TCP_INFO To: William Dauchy , netdev@vger.kernel.org Cc: davem@davemloft.net References: <20191002221017.2085-1-wdauchy@gmail.com> From: Eric Dumazet Message-ID: <025bcf1e-b7d4-5fa2-ec68-074c62b9d63c@gmail.com> Date: Wed, 2 Oct 2019 15:33:36 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20191002221017.2085-1-wdauchy@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 10/2/19 3:10 PM, William Dauchy wrote: > tsval and tsecr are useful in some cases to diagnose TCP issues from the > sender point of view where unexplained RTT values are seen. Getting the > the timestamps from both ends will help understand those issues more > easily. > Reporting the last recorded values is really not good, a packet capture will give you all this information in a non racy way.