From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-x242.google.com (mail-pg0-x242.google.com [IPv6:2607:f8b0:400e:c05::242]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 6B3283B2A3 for ; Sat, 3 Dec 2016 18:09:23 -0500 (EST) Received: by mail-pg0-x242.google.com with SMTP id 3so11850228pgd.0 for ; Sat, 03 Dec 2016 15:09:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:subject:from:to:cc:date:in-reply-to:references :mime-version:content-transfer-encoding; bh=8fvX0L0OPudSYmVGLKvg4XkYmJ8ktEXUiE5lLa1INFM=; b=DGX0SIZYCzOvvGWG/Lf9zKREV2tX04W6oVK9X3HF52LyfSoUat+0eXwT0gLW28SYGd dJTnVVSUOd6TlY03Bg5FQx9TPmp7eiR98vUUw2LM9F3NtPp1qwf2OnCiWqEGmxlSchc1 rgf+7EKLvvzEB+BBVJ676OR7DrMNgilHlGl2K3Ern5gN4YPB6isvcB219aSjpV6p3RCl Cx5vpyQzVXKPfz4aartL+epha/UEqSAq9l04R2PQ673ggThZZOTNup1Rm/pi/S1Eq9e6 TA9chGZj72r6A/8OXQoLHvnId6XJ9lewiiVjE49J/bkAp1zXGi5vUhO6DdjdpJczRaFW pz7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:mime-version:content-transfer-encoding; bh=8fvX0L0OPudSYmVGLKvg4XkYmJ8ktEXUiE5lLa1INFM=; b=jHI1Bk3abAGS1p0NzHRREpLDZ8SAQIuRSvXgBG1NHK8XvUQjjGpAt9LEK0fwCIs4ez GTpuI0SE54+UN7p9cjHxYPyzV4ORTDuj5o0tGpXL19VAA1c+RvHCZOOrX41NXizieFnA X1nJZnUVzToq3CWx7OdGiEVB1kBisdXb7RgwnIzFfU0DTqXrEJbwGE6cYdjSpmdIcYak qIR0lRa66uYldfqz7kdroLEpK08WMT+RJkN6zouLE8n13JKADIHoBILTZOyDBF7IGoC8 6TO7CnU3zRTT9D9LE6n/yQauzCowNSe5pDvwbSvSuZQHvtE2xZNHtLA/DRCraqljajC7 LaiQ== X-Gm-Message-State: AKaTC02HzrIR9rIaWhIHNaD/96fx6Ojn2h0aryT1McJ4CO8RMf9GvDNWeAYs4plcOrpmYg== X-Received: by 10.99.119.71 with SMTP id s68mr90765280pgc.11.1480806562707; Sat, 03 Dec 2016 15:09:22 -0800 (PST) Received: from [172.19.250.57] ([172.19.250.57]) by smtp.googlemail.com with ESMTPSA id c71sm17141292pga.22.2016.12.03.15.09.21 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 03 Dec 2016 15:09:22 -0800 (PST) Message-ID: <1480806561.18162.432.camel@edumazet-glaptop3.roam.corp.google.com> From: Eric Dumazet To: "Steinar H. Gunderson" Cc: Jonathan Morton , Neal Cardwell , "aqm@ietf.org" , bloat Date: Sat, 03 Dec 2016 15:09:21 -0800 In-Reply-To: <1480806161.18162.429.camel@edumazet-glaptop3.roam.corp.google.com> References: <20161202224006.GA5065@sesse.net> <1480721486.18162.392.camel@edumazet-glaptop3.roam.corp.google.com> <20161203191353.GA972@sesse.net> <1480796415.18162.408.camel@edumazet-glaptop3.roam.corp.google.com> <9A821B94-143B-446F-8852-2EB0158DD57C@gmail.com> <1480799260.18162.418.camel@edumazet-glaptop3.roam.corp.google.com> <20161203213428.GB38041@sesse.net> <1480801837.18162.419.camel@edumazet-glaptop3.roam.corp.google.com> <20161203221338.GC38041@sesse.net> <1480805737.18162.425.camel@edumazet-glaptop3.roam.corp.google.com> <1480806161.18162.429.camel@edumazet-glaptop3.roam.corp.google.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Bloat] TCP BBR paper is now generally available X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 03 Dec 2016 23:09:23 -0000 On Sat, 2016-12-03 at 15:02 -0800, Eric Dumazet wrote: > On Sat, 2016-12-03 at 14:55 -0800, Eric Dumazet wrote: > > > Perfect. > > > > Note that starting from linux-4.4, e1000e gets gro_flush_timeout that > > would help this precise workload > > Also it appears the sender uses a lot of relatively small segments (8220 > bytes at a time), with PSH, so GRO wont be able to help. > > I wonder how these PSH are forced. One possibility would be that the sender is not using fq/pacing, or some driver is using skb_orphan(), killing TCP Small queue. -> No pressure on qdisc, auto corking does not trigger, and application does small writes.