Received: by 2002:a25:8b91:0:0:0:0:0 with SMTP id j17csp522097ybl; Thu, 12 Dec 2019 23:44:08 -0800 (PST) X-Google-Smtp-Source: APXvYqzdMiYtLCUbASs+U0OKbikPYZ0qexKD1g+lWBZxjRpZ3NPDrzLAabx5yViXXgTF6uCYP4Ky X-Received: by 2002:a9d:4789:: with SMTP id b9mr13679105otf.110.1576223048030; Thu, 12 Dec 2019 23:44:08 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1576223048; cv=none; d=google.com; s=arc-20160816; b=KqE8daMXKPNqHJ/j8+QAcAUYxtOLlqng8B+jVVC0dAtpk7JKtYSWENGpAtpn8AlHqx Yrv4wV6XjqcaNd32MlgbdEkYoAyrtimjFN1vrZcAFE90Thwcdj2G/hmG4mlvz9PfXecm UESrEJDxraRC4Wd7ZT71IPigODhKe1IvOdhZSobuaIsfliSHN/L7mzDjY2l8II3VDiWf jMVxAKByUoBTxHN6K0RBCk9XdgK6F1Ko8febRbns24jvaMNXjFrOhp01f+aWOBVAV4Mj gYa0uwjlm7WcK0C435wkAzU9jsqVNw3SFMGbM6Tig3G7Pfy4nS5opUt2Gf7JUgDtrUIt Iseg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:date:cc:to:from:subject :message-id; bh=jIR2p7K04vP3ydNLUFFMUndwwiX9a37AUPz4MwGKtJk=; b=zEDvUPYvAlYqJu4xpv+WdUnUXjHIZsrjGeqbrY5wcSIN5Qx1/0HlW5SpezbJRwzocp UeiMKqQ1PpoNw4dtiHaGBWjdFdjFBylDbE8dtr4v+f2VYY26IXgGErlARBKS3veOUf5f RmXpgrAn5QovdjwwKH09o71io4yGbdZnvPH7mnpUlzVCft9QdaA7UKBqnrdCdevk/sBQ 4c8lYK4HlRsqdSNMFIcvztYryCPR1XUfpDBg1ry4to/UEo44YkN181u14M/KbZfFZslB Y0krJ6j7W6bKSgWcGCM+KkUw0IMh2x4/XdyVmrGyT0hyFQsjHG7MWlVeVUiPK1Vn43PB AmWA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-wireless-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-wireless-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id z14si4359156oih.89.2019.12.12.23.43.52; Thu, 12 Dec 2019 23:44:08 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-wireless-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-wireless-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-wireless-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725809AbfLMHna (ORCPT + 99 others); Fri, 13 Dec 2019 02:43:30 -0500 Received: from s3.sipsolutions.net ([144.76.43.62]:42382 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725468AbfLMHna (ORCPT ); Fri, 13 Dec 2019 02:43:30 -0500 Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.92.3) (envelope-from ) id 1iffbj-009Nc2-Ph; Fri, 13 Dec 2019 08:43:27 +0100 Message-ID: <90485ecbfa2a13c4438b840c8a9d37677e833ea5.camel@sipsolutions.net> Subject: Re: debugging TCP stalls on high-speed wifi From: Johannes Berg To: Justin Capella Cc: Eric Dumazet , Toke =?ISO-8859-1?Q?H=F8iland-J=F8rgensen?= , linux-wireless@vger.kernel.org, netdev@vger.kernel.org Date: Fri, 13 Dec 2019 08:43:26 +0100 In-Reply-To: (sfid-20191213_051528_721069_3C6497DE) References: <14cedbb9300f887fecc399ebcdb70c153955f876.camel@sipsolutions.net> (sfid-20191213_051528_721069_3C6497DE) Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.34.2 (3.34.2-1.fc31) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Thu, 2019-12-12 at 20:15 -0800, Justin Capella wrote: > Could TCP window size (waiting for ACKnowledgements) be a contributing factor? Quite possibly, although even with a large number of flows? I thought we had a TCP_CHRONO_ for it but we don't, maybe I'll try to add one for debug. johannes