From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-x232.google.com (mail-pa0-x232.google.com [IPv6:2607:f8b0:400e:c03::232]) (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 6518C3B260 for ; Sat, 10 Sep 2016 23:16:59 -0400 (EDT) Received: by mail-pa0-x232.google.com with SMTP id id6so40420464pad.3 for ; Sat, 10 Sep 2016 20:16:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=3hhkZZ/+DR2nl7VXB7EJ2MvOXAXpIuRRJyhA9MfD11I=; b=U96cKckbWeB8am5rXE/1omDOf19sFBQB8x7cQL5jTiSkkNUkqgvxQl1mdUtGeyQoWT Vs2yhwpWJXEbF46yE5OLUfXBRc9YBeVKPr1WSmdlH9OmtiHhSzvtHG0bgnhkARqC4xPQ SpuI4RwPuWbHAi2AXF3pqmrkFRObrgHH2Zof4Gbssq261GWzjRKi/UQditNGpH4qRVbn 01OF2O+PprGS2cUxNh6PKAVUu4ASig7emBNH4YsF50DK/cY/xnd4hbVa7wKUmTVq82Wx MhaFkjY/G0Vff5DDQtzRtGM4lyJeLyqncAAZfrHdJ0/ZKwusUdGN7dVp+qTSSL0tZdMi u9HA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=3hhkZZ/+DR2nl7VXB7EJ2MvOXAXpIuRRJyhA9MfD11I=; b=IDPnGZZaBdp9C0Oyzo9qT+K2UdNYVvngPref6PigzOXllT29qYz1c26UnbkTTuR90S Z0KeE62l/K2Nmjz/1WwytYKh4/TCIBbTVety5bmt2p2ezV+nVTTHf9HzkV/rDc3t3sRY lq8yERdNP41avDVD4nW7T6XiOiwWJT5tgAeRXeiQ4GicUSQMZbIyF8oHIIv5yPDXgkwG Us57AhKUlpiku3lL/2oDy019517XVbUrWtgmz3Q2sXfa3tZkD+57C0HI12Ebkkaay9vB h3UAB88t6hSiL+oeHY09AKJdNUTZ+pNGJuTVzYMvz0biDAKYPojIZu4oyyIwJn4Ex0oE 6kyQ== X-Gm-Message-State: AE9vXwOzzbjXJo0/GRjzGifj9lAEYiZOK3AxtdxN0Qx366eEhA7BjKBm8YLaObrBb5dfM4IUDvA2xapSqZocIQ== X-Received: by 10.66.127.38 with SMTP id nd6mr20833425pab.74.1473563818627; Sat, 10 Sep 2016 20:16:58 -0700 (PDT) MIME-Version: 1.0 Received: by 10.66.102.70 with HTTP; Sat, 10 Sep 2016 20:16:58 -0700 (PDT) In-Reply-To: References: <20160910193315.30738-1-toke@toke.dk> From: Loganaden Velvindron Date: Sun, 11 Sep 2016 07:16:58 +0400 Message-ID: To: Jim Gettys Cc: =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= , make-wifi-fast@lists.bufferbloat.net, linux-wireless , Felix Fietkau Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Make-wifi-fast] [PATCH] mac80211: Dynamically set CoDel parameters per station. 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: Sun, 11 Sep 2016 03:16:59 -0000 On Sat, Sep 10, 2016 at 11:54 PM, Jim Gettys wrote: > > > On Sat, Sep 10, 2016 at 3:33 PM, Toke H=C3=B8iland-J=C3=B8rgensen > wrote: >> >> CoDel can be too aggressive if a station sends at a very low rate, >> leading to starvation. This gets worse the more stations are present, as >> each station gets more bursty the longer the round-robin scheduling >> between stations takes. >> >> This adds dynamic adjustment of CoDel parameters per station. It uses >> the rate selection information to estimate throughput and sets more >> lenient CoDel parameters if the estimated throughput is below a >> threshold. To not change parameters too often, a hysteresis of two >> seconds is added. > > > Where is this 2 second constant coming from? I'd expect it should be of > order the maximum RTT (or a small constant factor of that, which for > intercontinental connections should be 200-300ms. > Indeed, from Mauritius (Africa) to remote countries like Australia, or parts of the US, we see latencies of up to 500-600ms.