From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-x236.google.com (mail-wi0-x236.google.com [IPv6:2a00:1450:400c:c05::236]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 1DE8021FE0D; Fri, 7 Aug 2015 06:28:16 -0700 (PDT) Received: by wicgj17 with SMTP id gj17so61618794wic.1; Fri, 07 Aug 2015 06:28:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=content-type:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=15sHAyUSeV7LTSgtbe9Woq1AP5vIzN8z2bX3DiMc6lI=; b=RjXJKOxwpzQVVHnMxzH1fCjDDMH/yPFYHRvDOyNBZlN2aYXCC56WmzKY7Za+NS4NrD SaT5gjF9uoQbH/QflTqsgs69FwB4BYPE6J4SNIMooQT4qIbbpUH6pS/Ee10NMqVo4G4L ljC5pe4IwYQxo6oijbg2RMKiwgRuzPaFk/BJur/5Bqd6qpiLBSEE21JmAYxfV415p/kQ Qt6zfv3wIEs0FpMMec37+MJ4jG0n0v0IYk3LL9PYGPGiccZkkC99I1jqmJPSPv3agemV o+ZOpmNQwwqYMoCc4zyE6CA7J0qWgv1ROdF4vI4cS8c5ry9QpZDbf6C1FvqDEhsbReGv n5sA== X-Received: by 10.180.218.227 with SMTP id pj3mr7006942wic.59.1438954094938; Fri, 07 Aug 2015 06:28:14 -0700 (PDT) Received: from jonathartonsmbp.lan ([46.54.226.50]) by smtp.gmail.com with ESMTPSA id fm8sm8540739wib.9.2015.08.07.06.28.13 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 07 Aug 2015 06:28:14 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2102\)) From: Jonathan Morton In-Reply-To: Date: Fri, 7 Aug 2015 15:28:10 +0200 Content-Transfer-Encoding: quoted-printable Message-Id: <6E08E48D-5D53-48E5-B088-2D1DB5E566AD@gmail.com> References: <356F5FEE-9FBD-4FF9-AC17-86A642D918A4@gmail.com> <5CC1DC90-DFAF-4A4D-8204-16CD4E20D6E3@gmx.de> <4D24A497-5784-493D-B409-F704804326A7@gmx.de> <1438361254.45977158@apps.rackspace.com> To: Rich Brown X-Mailer: Apple Mail (2.2102) Cc: make-wifi-fast@lists.bufferbloat.net, dpreed@reed.com, cerowrt-devel@lists.bufferbloat.net, Mikael Abrahamsson Subject: Re: [Make-wifi-fast] [Cerowrt-devel] [tsvwg] Comments on draft-szigeti-tsvwg-ieee-802-11e X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 07 Aug 2015 13:28:45 -0000 > On 7 Aug, 2015, at 15:22, Rich Brown wrote: >=20 > - At that time, the wifi driver requests packets from fq_codel until = a) the the fq_codel queues are empty, or b) the wifi frame is full. In = either case, the wifi driver sends what it has. There=E2=80=99s one big flaw with this: if packets are available for = multiple destinations, fq_codel will generally give you a variety pack = of packets for each of them. But a wifi TXOP is for a single = destination, so only some of the packets would be eligible for the same = aggregate frame. So what=E2=80=99s needed is a way for the wifi driver to tell the queue = that it wants packets for the *same* destination as it=E2=80=99s = transmitting to. > - Once the transmit opportunity has come around, it's a matter of = microseconds (I assume) to pull in a wifi frame's worth of packets from = fq_codel This is hard to guarantee in software in a general-purpose OS. - Jonathan Morton