From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vn0-x22f.google.com (mail-vn0-x22f.google.com [IPv6:2607:f8b0:400c:c0f::22f]) (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 5B70821F561 for ; Thu, 4 Jun 2015 13:31:45 -0700 (PDT) Received: by vnbf1 with SMTP id f1so6607729vnb.6 for ; Thu, 04 Jun 2015 13:31:45 -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; bh=BbpPtt6xAWlqq/jwXDSbMoeNCW5dH0QELcfMAmRSxxQ=; b=v1vjHAqVAVQ/+Fn2EbQZoaul6e8i5b8ER/7IvYfydsE8KBME6H8+Mc/4mV2KD7I8SP 2A2DNKYBZ3cT4nBh72DfsU7EWJlu14ll8/Uv8dRbwHsm+B+LKMu9ZVgfvJECHBQzz8fm tV9/Y+XvqrHUFI+mOmpz3ZIyhuQnE54My550gLRlESA8E3oZotYF5ez5HDnVAEPCrrep 7bAE0ibhwHWrMYYx10kuGnPgBS6z80LsPj3f1Iia+QsXLDlQ3H72f5MCT4GX2KQqLI9E EkvdgeNeDBTz0mvP4hTTmwmdxXmQQt2luyWM7+Xapr+h4jdN1ZY78c7BhDW+pdviykXw lYoA== MIME-Version: 1.0 X-Received: by 10.52.174.48 with SMTP id bp16mr10863923vdc.35.1433449904889; Thu, 04 Jun 2015 13:31:44 -0700 (PDT) Received: by 10.52.12.167 with HTTP; Thu, 4 Jun 2015 13:31:44 -0700 (PDT) Received: by 10.52.12.167 with HTTP; Thu, 4 Jun 2015 13:31:44 -0700 (PDT) In-Reply-To: References: Date: Thu, 4 Jun 2015 23:31:44 +0300 Message-ID: From: Jonathan Morton To: Dave Taht Content-Type: multipart/alternative; boundary=bcaec51b181562628f0517b7107c Cc: cake@lists.bufferbloat.net Subject: Re: [Cake] a little bit of cake testing X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 04 Jun 2015 20:32:14 -0000 --bcaec51b181562628f0517b7107c Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable In summary, the new Codel behaviour works better on egress but worse on ingress. That's reasonable - on ingress the queue always appears to build slowly, so the new scheme always triggers late, and is more likely to return aggressively to a lower signalling rate. I think we're going to need a special mode for ingress. However, I think a good deal of your poor results are due to not properly matching the actual link bandwidth any more. I would suspect trouble in the cable rather than the modem, given the symptoms. - Jonathan Morton On 4 Jun 2015 21:11, "Dave Taht" wrote: > not very well controlled dataset at: > http://snapon.lab.bufferbloat.net/~d/fishcake/ > > On Thu, Jun 4, 2015 at 11:10 AM, Dave Taht wrote: > > I did a bit of setup on my connection to give me a decent rrul result. > > (I was not rate limiting inbound enough) The duration of the initial > > load spike is much less pronounced than the fq_codel result. I note > > that I have offloads still on, so I imagine fq_codel is getting > > tweaked by that.... > > > > but ingress gets way out of hand later on in this test. I can make an > > argument for decay (count/2) being far too aggressive. In fact, even > > count - 2 seemed too much in older testing I had done with other > > variants. I would certainly like to get a feel for when and where the > > three parts of codel are kicking in in various workloads. > > > > http://www.dslreports.com/speedtest/613646 > > > > I really need to get to where I can quickly get to a blog entry on > > this stuff, and back to comprehensive, controlled testing. > > > > > > > > > > > > On Thu, Jun 4, 2015 at 10:11 AM, Dave Taht wrote: > >> My network here is in flux (new modem, signal strength problems, cable > >> problems) and toke's testbed is presently doing wifi work, so I did a > >> quick mod to fishcake to make it do linux 4.0 (note I am not sure if > >> this was a 4.1 or a 4.0 change) - attached. (and we lose a few cake > >> options due to me not grokking the new API) > >> > >> Cake did well on this, but the behavior at the tail end of the test > >> was disturbing: > >> > >> http://www.dslreports.com/speedtest/611312 > >> > >> Need to do some work to emulate the dslreports tests. > >> > >> And it dropped LOT more packets than fq_codel did. fq_codel marked 33 > >> packets for it's result, cake marked 600 and dropped 200, for its. > >> > >> I did some rrul testing as well, but was fighting with a modem that > >> used to get 140Mbits, and now only gets 70mbits, and behaves very > >> differently overall with pfifo_fast than i had ever seen before. And > >> along the way snapon got upgraded a bit too... sigh... > >> > >> -- > >> Dave T=C3=A4ht > >> What will it take to vastly improve wifi for everyone? > >> https://plus.google.com/u/0/explore/makewififast > > > > > > > > -- > > Dave T=C3=A4ht > > What will it take to vastly improve wifi for everyone? > > https://plus.google.com/u/0/explore/makewififast > > > > -- > Dave T=C3=A4ht > What will it take to vastly improve wifi for everyone? > https://plus.google.com/u/0/explore/makewififast > _______________________________________________ > Cake mailing list > Cake@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/cake > --bcaec51b181562628f0517b7107c Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

In summary, the new Codel behaviour works better on egress b= ut worse on ingress. That's reasonable - on ingress the queue always ap= pears to build slowly, so the new scheme always triggers late, and is more = likely to return aggressively to a lower signalling rate. I think we're= going to need a special mode for ingress.

However, I think a good deal of your poor results are due to= not properly matching the actual link bandwidth any more. I would suspect = trouble in the cable rather than the modem, given the symptoms.

- Jonathan Morton

On 4 Jun 2015 21:11, "Dave Taht" <<= a href=3D"mailto:dave.taht@gmail.com">dave.taht@gmail.com> wrote:
not very well controll= ed dataset at:
http://snapon.lab.bufferbloat.net/~d/fishcake/

On Thu, Jun 4, 2015 at 11:10 AM, Dave Taht <dave.taht@gmail.com> wrote:
> I did a bit of setup on my connection to give me a decent rrul result.=
> (I was not rate limiting inbound enough) The duration of the initial > load spike is much less pronounced than the fq_codel result. I note > that I have offloads still on, so I imagine fq_codel is getting
> tweaked by that....
>
> but ingress gets way out of hand later on in this test. I can make an<= br> > argument for decay (count/2) being far too aggressive. In fact, even > count - 2 seemed too much in older testing I had done with other
> variants. I would certainly like to get a feel for when and where the<= br> > three parts of codel are kicking in in various workloads.
>
> http://www.dslreports.com/speedtest/613646
>
> I really need to get to where I can quickly get to a blog entry on
> this stuff, and back to comprehensive, controlled testing.
>
>
>
>
>
> On Thu, Jun 4, 2015 at 10:11 AM, Dave Taht <dave.taht@gmail.com> wrote:
>> My network here is in flux (new modem, signal strength problems, c= able
>> problems) and toke's testbed is presently doing wifi work, so = I did a
>> quick mod to fishcake to make it do linux 4.0 (note I am not sure = if
>> this was a 4.1 or a 4.0 change) - attached. (and we lose a few cak= e
>> options due to me not grokking the new API)
>>
>> Cake did well on this, but the behavior at the tail end of the tes= t
>> was disturbing:
>>
>> http://www.dslreports.com/speedtest/611312
>>
>> Need to do some work to emulate the dslreports tests.
>>
>> And it dropped=C2=A0 LOT more packets than fq_codel did. fq_codel = marked 33
>> packets for it's result, cake marked 600 and dropped 200, for = its.
>>
>> I did some rrul testing as well, but was fighting with a modem tha= t
>> used to get 140Mbits, and now only gets 70mbits, and behaves very<= br> >> differently overall with pfifo_fast than i had ever seen before. A= nd
>> along the way snapon got upgraded a bit too... sigh...
>>
>> --
>> Dave T=C3=A4ht
>> What will it take to vastly improve wifi for everyone?
>> https://plus.google.com/u/0/explore/makewififast
>
>
>
> --
> Dave T=C3=A4ht
> What will it take to vastly improve wifi for everyone?
> https://plus.google.com/u/0/explore/makewififast



--
Dave T=C3=A4ht
What will it take to vastly improve wifi for everyone?
https://plus.google.com/u/0/explore/makewififast
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