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=-8.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 E0C39C43603 for ; Thu, 12 Dec 2019 15:11:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A36DC21655 for ; Thu, 12 Dec 2019 15:11:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="KLHrpDMb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728926AbfLLPLc (ORCPT ); Thu, 12 Dec 2019 10:11:32 -0500 Received: from mail-ot1-f50.google.com ([209.85.210.50]:39034 "EHLO mail-ot1-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728654AbfLLPLc (ORCPT ); Thu, 12 Dec 2019 10:11:32 -0500 Received: by mail-ot1-f50.google.com with SMTP id 77so2316582oty.6 for ; Thu, 12 Dec 2019 07:11:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=kIhIS2YRgmUMObqWxEWVGA4aACRsODuzv8jQKXYM0Rg=; b=KLHrpDMbmnM81Q4xUZEG5d3l2uH6WXOvotUm+GFFDLPgzTXjQcGWpSLwq/gBKO1nxC z050ENWHsjL9MnzFu+svtP7MvZI1D0Hnxzagle755XHKlgdAIc3Z/nC8SL0M7m9dU9AW BOgrfbmIWScHGcA88UbThBiFxJJLMKUYUbNGcEt9C8HTwOVM62sYL4fkzg98Pyr9JwBM RPdDhVzu5STJxJOBr1TDvEoPgFRxdhTFo43PEL57Vv6hp4Ps3fh87Kt+/UnyFkClbnWL Eincvd+SSSUiDRdk1peT+d4JFk8HyrcqAhOHKmP0BBl99JRFfsS0ZXO0YUWsR9r8/X0q Xc8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=kIhIS2YRgmUMObqWxEWVGA4aACRsODuzv8jQKXYM0Rg=; b=cqKhE7nY/4RDXYEAAtRopHmz4KWVxTbGJfKUpIraL/x2KTIMxmHudpZHzENxFfvmDO YfEgqFHrMkbQ4qpOLnKx0nSJ/8UrptLGObV77p9e2ZqkHqLpkFPJNjCo6drETkpSn2Ta oeas1NAvB6EksIzWeFwR8MifcbudHeRX3jE0TjAvBF2+cVhHqNujBTSbLUC/XIg+x7zj DBnyd5gPVfcWEgbbyrf3Vh2exYjun+jFn4L3CuV9tOBRUO5szYRdioT7v57JUp//oW2N rY3idSdbeuIqtXdTejZuFdAdSjG/pB6VcXn3MlaNQ9kktL8shy2Rh+EVF4gK0W1eOKtz 7RjQ== X-Gm-Message-State: APjAAAXYDLrK/KQiu00otS9SMiYO7ksuw2uY+sZlFFR8alKUtfPpPKaH PELuO7tZ/bWIC26xfT7MpxNsbaulbTqDAXFNBaljsQ== X-Google-Smtp-Source: APXvYqxy+6Sljwk7iFfOaKx/1+V4f5mtJq5yy/t6TSwXFxYoJS86rUxJqzrstDSC4Q6jeoGnMBriYVzN5yyFeM0koTU= X-Received: by 2002:a9d:624e:: with SMTP id i14mr8755970otk.371.1576163491195; Thu, 12 Dec 2019 07:11:31 -0800 (PST) MIME-Version: 1.0 References: <14cedbb9300f887fecc399ebcdb70c153955f876.camel@sipsolutions.net> In-Reply-To: <14cedbb9300f887fecc399ebcdb70c153955f876.camel@sipsolutions.net> From: Neal Cardwell Date: Thu, 12 Dec 2019 10:11:14 -0500 Message-ID: Subject: Re: debugging TCP stalls on high-speed wifi To: Johannes Berg Cc: Eric Dumazet , =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= , linux-wireless@vger.kernel.org, Netdev Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Dec 12, 2019 at 9:50 AM Johannes Berg wrote: > If you have any thoughts on this, I'd appreciate it. Thanks for the detailed report! I was curious: o What's the sender's qdisc configuration? o Would you be able to log periodic dumps (e.g. every 50ms or 100ms) of the test connection using a recent "ss" binary and "ss -tinm", to hopefully get a sense of buffer parameters, and whether the flow in these cases is being cwnd-limited, pacing-limited, send-buffer-limited, or receive-window-limited? o Would you be able to share a headers-only tcpdump pcap trace? thanks, neal