From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-x235.google.com (mail-pg0-x235.google.com [IPv6:2607:f8b0:400e:c05::235]) (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 E7BEC3B2A3 for ; Tue, 15 Nov 2016 13:36:07 -0500 (EST) Received: by mail-pg0-x235.google.com with SMTP id f188so69166321pgc.3 for ; Tue, 15 Nov 2016 10:36:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=gGGbwgUZ9K+6UBmxaBLl5LhNbTXRy9suytvQyAOMn8Y=; b=MbrQJXyizg1FMNY1pv1KkyLLS7WFpndWxf1ALISu3OT5oUwsO9d0zYOaEqQz0AYtLK h9+IIOhr1oSoujAaWl0KPmbSaDcIfyrffEY/UfA1WQhxmhUBtjr/GBeOCVCijZn+dX2F TNUQh8dY0uHZ2ODE8XLh375EUrPIH2Ep3qiH4wRWhaSkQWdeYVLdiNvNO65TL6RLpNIL GCN1jQ//dbXzBU2U1ld8WFFqaRNvvehbeDT9f5+hSpJmsm57/IPqi6HMoIOEZLOYgSfu W80QGMb2MKjzip1X3TZUo+aPF/2ABazFJ8rpz6KC7sn+tUSx6eZLjn4a3lSCCD+VgsAU lCvg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=gGGbwgUZ9K+6UBmxaBLl5LhNbTXRy9suytvQyAOMn8Y=; b=NPRYBOI3arqFXOEvVO3Vpp1oN3b6rNBDh1LJuSZ3Myk2+Z01c7Clx1JbI5+PnGie3j Q1ChRcVfoSmebjkKom6KObjHBQUGQfsShNX3sgSigzNA4wyqdtWH375GQV3vAefmtDdJ 2IEinY16bBm88OBVh6Mfxs1FL/Z7a5ZzelGR1Mxa+0R/lautvlWCrFbmwmL59uu7WkMH 4VLb17J8Mfi3bvBhbdp/FlWIDy5928Zxdi+ul8ECODYRdIzM4IbEYZMqfJoFMkXej6Pv fKYE0Uby1xAULGxu3g0WVM9lJf+U5ge/Br8WHWU+Yvc5tA3l0YGRiZfmPaqreKWRyWmq dc5Q== X-Gm-Message-State: ABUngvcqpypCnmVY/VfijYEWOFxUI/2/52qCYHINamsirPPQllqD2PkSTpbdOLBOnnu12A== X-Received: by 10.98.81.70 with SMTP id f67mr48556918pfb.179.1479234967094; Tue, 15 Nov 2016 10:36:07 -0800 (PST) Received: from samsung9 (204-195-68-67.wavecable.com. [204.195.68.67]) by smtp.gmail.com with ESMTPSA id y2sm45220750pff.82.2016.11.15.10.36.06 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 15 Nov 2016 10:36:06 -0800 (PST) Date: Tue, 15 Nov 2016 10:36:05 -0800 From: Stephen Hemminger To: Rich Brown Cc: bloat , make-wifi-fast@lists.bufferbloat.net Message-ID: <20161115103605.02904558@samsung9> In-Reply-To: <156EE814-3742-4F23-99AC-7905077B1803@gmail.com> References: <156EE814-3742-4F23-99AC-7905077B1803@gmail.com> X-Mailer: Claws Mail 3.14.0 (GTK+ 2.24.31; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Bloat] QCut - "Understanding on-device bufferbloat for cellular upload", Guo et al 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: Tue, 15 Nov 2016 18:36:08 -0000 On Tue, 15 Nov 2016 12:00:29 -0500 Rich Brown wrote: > Google Alerts sent a link to this paper: "Understanding on-device bufferbloat for cellular upload" available at: http://dl.acm.org/citation.cfm?id=2987490 (ACM Paywall...) > > In my two-minute skim of the paper, I see they describe how latency gets bad on cellular devices (no kidding) and then propose QCut, a queue inserted between the qdisc and the hardware. They say: > > --- > ... QCut operates in the kernel space and takes as input only information of buffer occupancy and transmission statistics, which is exposed by most cellular radio firmware from Qualcomm and likely other vendors. > > Since directly limiting the firmware buffer occupancy is difficult, QCut controls the firmware queuing delay indirectly in the kernel by controlling how fast packets from Qdisc flow into the firmware buffer. QCUT estimates the radio firmware buffer occupancy and queuing delay to decide the transmission of packets to the firmware dynamically... > --- > > Their analysis and charts show that QCut helps a lot. > > I found it interesting that they make measurements with both weak and strong signal strength, to indicate the hits that are caused by differing signal strength. > > Enjoy! > > Rich > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat Reinvention of BQL?