From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 1DAFD3B29D for ; Wed, 5 Feb 2020 11:17:05 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580919424; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Ca6RjbS+CWA9lpAbjXj3ZuG6sXyo+b8AfiT6VIZSn2A=; b=Z+25/dh0jXzfCBsDBHrEnuQlhCwbX9a4dWiLUCexrElgUOJ+XRPSRNhC9G6Rw+zs8sOmy2 46Pd18jBDeSlBcUlyoMe6z6OO0VSp2vBKidywwmzTqs6TtNBSrH9524zajlWMhiGSq2wY8 8gpnt8ZBaBJMskGppK9grn5xheWETWs= Received: from mail-lj1-f197.google.com (mail-lj1-f197.google.com [209.85.208.197]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-308--31KQQzAMnq0IsJRHuSnMw-1; Wed, 05 Feb 2020 11:16:49 -0500 Received: by mail-lj1-f197.google.com with SMTP id j21so328458lji.12 for ; Wed, 05 Feb 2020 08:16:48 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version:content-transfer-encoding; bh=PGejSt8tB9dvuaFzx/g8ZdfPEgpddvaoMtZwYtRhsjE=; b=rJc9TuEnrjsGOiKrp4F0jHqSISfVoEyhvC+kamDkA9LmRZ/fDQtkzaBG5gJ9x1TGpX NOxLiWXceGTPhLW9OvIyvnlg7uXtA4whUN14oubV98YDP8jWfSi7PVornV5f1LslSyUw XvT0urrIE8sxF/txm9AKZfT4jHll1RAxsV4qgPiK/1LsWRG0R7BvLoc9BOKyD+XHWeTh azye5suqND8Wi0vj1bxwy5j/WLT5BvlipWayZzeAHBjGrnAcrlEbqys2jlA8DDzEzjPC BNZf3A+5SDZKYcQYahUcEjSeRw+LeScPUvQUJGuf9WRTght+H3Tl4qp76A7lmVZQ+kWG CMng== X-Gm-Message-State: APjAAAUtVydK06kCVaFwmlrwK95sCIPcCCoNtsM3FOhd7ka7dCMgI1Ou KBCX+7w9iRGZeeWr5D6ar4Ye3yPyuNcKbgML5FoZk0JVk5e+UsLLImuN5xcMfpAGxQHeoh5N/XW ErBjyDpSuMwkJAgpe8IzdNWd7ji7h5FoHgxQ= X-Received: by 2002:a2e:88d6:: with SMTP id a22mr19583535ljk.163.1580919406566; Wed, 05 Feb 2020 08:16:46 -0800 (PST) X-Google-Smtp-Source: APXvYqz7329m+lnYA2gOmpa4E/mUoYaGCPb6yb3tGWykbyhISAu0HXENj2ZeFq0KFusAATiunt8MdA== X-Received: by 2002:a2e:88d6:: with SMTP id a22mr19583511ljk.163.1580919405916; Wed, 05 Feb 2020 08:16:45 -0800 (PST) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id y66sm12431783lfa.53.2020.02.05.08.16.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Feb 2020 08:16:45 -0800 (PST) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 791991802D4; Wed, 5 Feb 2020 17:16:44 +0100 (CET) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Dave Taht , =?utf-8?Q?Bj=C3=B8rn?= Ivar Teigen Cc: Cake List , Make-Wifi-fast In-Reply-To: <87v9oluih6.fsf@taht.net> References: <07250850-5FAF-4AB7-9551-0B26D648AF3D@gmail.com> <87v9oluih6.fsf@taht.net> X-Clacks-Overhead: GNU Terry Pratchett Date: Wed, 05 Feb 2020 17:16:44 +0100 Message-ID: <87y2thc8lv.fsf@toke.dk> MIME-Version: 1.0 X-MC-Unique: -31KQQzAMnq0IsJRHuSnMw-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Make-wifi-fast] [Cake] Cake in mac80211 X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 05 Feb 2020 16:17:05 -0000 Dave Taht writes: > Bj=C3=B8rn Ivar Teigen writes: > >> Thanks for the feedback! >> >> Some comments and questions added inline. >> >> On Tue, 4 Feb 2020 at 18:07, Dave Taht wrote: >> >> On Tue, Feb 4, 2020 at 7:25 AM Jonathan Morton >> wrote: >> > >> > > On 4 Feb, 2020, at 5:20 pm, Bj=C3=B8rn Ivar Teigen >> wrote: >> > > >> > > Are there any plans, work or just comments on the idea of >> implementing cake in mac80211 as was done with fq_codel? >> > >> > To consider doing that, there'd have to be a concrete benefit to >> doing so. >> =20 >> Research is research! :) Everything is worth trying! There's got >> to be >> some better ideas out there, and we have a long list of things we >> could have done to keep improving wifi had funding not run out. >> =20 >> We barely scratched the surface of this list. >> =20 >> https://docs.google.com/document/d/1Se36svYE1Uzpppe1HWnEyat_sAGghB3k= E285LElJBW4/edit >> =20 >> =20 >> > Most of Cake's most useful features, beyond what fq_codel >> already supports, are actually implied or even done better by the >> WiFi environment and the mac80211 layer adaptation (particularly >> airtime fairness). >> =20 >> In my opinion(s) >> =20 >> A) I think ack-filtering will help somewhat on 802.11n, but it's >> not >> worth the added cpu cost on an AP and I'd prefer hosts reduce >> their >> ack load in the tcp stack (IMHO, others may differ, it's worth >> trying) >> B) The underlying wifi scheduler essentially does per host fq >> better >> than cake can (because it's layer 2 vs layer 3), as per jonathan's >> comment above=20 >> >> C) Instead of using a 8 way set associative hash and 1024 queues, >> fq_codel for wifi uses 4096 with a disambiguation pointer for >> collisions. Seems good enough. >> =20 >> >> Didn't catch that before. Are the extra queues there because of the >> different access categories on Wi-Fi? Seems like that would mean most >> of them are not in use considering how little traffic is marked with >> DSCP. > > I wasn't counting those. There's one set of 4k queues per access > class. Nit: not per access class; they're shared across the whole phy. -Toke