From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-x234.google.com (mail-qg0-x234.google.com [IPv6:2607:f8b0:400d:c04::234]) (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 06D6121F623 for ; Fri, 19 Jun 2015 10:35:41 -0700 (PDT) Received: by qgeu36 with SMTP id u36so38638805qge.2 for ; Fri, 19 Jun 2015 10:35:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=/JIXEp8St02+P9hs+vpR769UbQyebGzGwCfzUoWnSYw=; b=hOqRn07YFTZutBconoZnNMdNvCBC5I4DXqkrv5zKfGTxcS8NBXecrL+MjehU9uQh1h Kmze3+bljLuYQmhSaD7UJcUfvIIztgOLVbonzdeMY0aMBUfedVqSTyGiodqRH21HV2uj dtyZP5zzmhxNr5SOP5MCeaot5O8QMKHGxW59DaunThoHT7gbMLJJvSOj4Jd+NCdqSw+s 7HSiv0TNwokzJH62sFy4pG8wN9dzpAqfSRZsYYL9E7vd9UYu5ik1MewOkCfBTcCSNSlq gYEpXx6IxrhAtjPNzdMKa2ugqXdASHcsoUqZQ2QGbBjG20tZ3CuVKdbf0etRuVTNnqco jv2g== MIME-Version: 1.0 X-Received: by 10.140.236.77 with SMTP id h74mr23870290qhc.21.1434735340798; Fri, 19 Jun 2015 10:35:40 -0700 (PDT) Received: by 10.96.183.194 with HTTP; Fri, 19 Jun 2015 10:35:40 -0700 (PDT) In-Reply-To: <26463A88-821B-44B7-A728-64BCB0B7C7BB@gmx.de> References: <26463A88-821B-44B7-A728-64BCB0B7C7BB@gmx.de> Date: Fri, 19 Jun 2015 18:35:40 +0100 Message-ID: From: Alan Jenkins To: Sebastian Moeller Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: Jonathan Morton , cerowrt-devel Subject: Re: [Cerowrt-devel] Latest build test - new sqm-scripts seem to work; "cake overhead 40" didn't X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 19 Jun 2015 17:36:11 -0000 On 19/06/2015, Sebastian Moeller wrote: > Hi Alan, > > excellent, thanks a million. > > On Jun 19, 2015, at 16:44 , Alan Jenkins > wrote: > >> Hi >> >> I guess I've done the complementary half to Seb's test :). Basically >> "cake overhead 40" didn't work, but that's the fault of cake in this >> build. Or tc, as Johnathan suggested. (The "cake atm" part seems to >> work, as per my previous test). > > Great! > >> >> "tc qdisc" says "cake overhead 0", as Sebastian noticed. And the test >> results show "cake overhead 40" does not give a measurable >> improvement. But "tc stab overhead 40" does. >> >> I ran this test with the updated sqm-scripts and I think they're doing >> the right thing. > > Thanks for testing this, especially as I can not due to a lack of an > ADSL-link (and lack of cake actually, last I looked all I could find was > cookies in my browser and a promise of pie in my router) > >> >> >> Method: >> >> I used the updated files from sqm-scripts, >> >> (once I remembered to mark them executable. Lacking that causes a >> failure with no error messages, because sqm-scripts checks before >> running them :) >> >> but didn't bother updating & using luci-app-sqm. > > Ah, okay, I guess I did test this part with Dave=E2=80=99s help, so this= should > work with the most recent sqm.lua. > >> >> The test was to compare netperf-runner results - ping during combined >> upload & download - for "overhead 40" and "overhead 0". I tested both >> values of linklayer_adaptation_mechanism. >> >> I had to repeat 6 times (60s per run for each overhead) because of >> random variation in the range of 3-4ms. I alternated "overhead 40" >> and "overhead 0" to try and exclude longer-term variation effects. >> >> With "stab overhead 40", median latency was better by about 3-4ms. >> With "cake overhead 40", there is no such effect. > > Intersting, when I still had a 6M/1M ADSL link, I saw much larger latenc= y > under load increases when setting the per packet overhead to small, but I > had my egress shaper running at 100% of line rate, so the system was rigg= ed > for maximum effect that way. How are your shapers typically set? For this test I try to push it, today I used 95%. I started trying 100%, which is still much better than unshaped. I was scared off by the random variation, I think it was higher at 100%. For long term use I reduce it, because I've seen the line rate vary slightly. (1020k up today, 912 a while back. Currently it reports a "max" figure I don't understand, it's about 1100 despite being rebooted daily. 16390k down). Alan