From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-x22d.google.com (mail-wi0-x22d.google.com [IPv6:2a00:1450:400c:c05::22d]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 299E621F1D9 for ; Wed, 14 Aug 2013 17:42:01 -0700 (PDT) Received: by mail-wi0-f173.google.com with SMTP id en1so2623494wid.12 for ; Wed, 14 Aug 2013 17:42:00 -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=wCrl1lW5J26T1W2yGhONWV61B3g3+ZbENyDmfW4usrU=; b=PT9WG66AmteMIDf2I9shM3qcZCo6gKX7DYGmg1WUZc9vyeyswq/xxuox4+5cIUEj1X Z1+zDR8iYo988YMbfOTWGJLt/3Ji1S9BMhrM6LlELM2+RsxFnfIV09dELTnLNHeGhinH 5JXOMl7ZeRQO82FX3MiESuWpqn0Rf618ENCFk8t4vvzl4lsAT/toT/n4/w7rNgYPhzHT ECXX1v4NoeYu2YApjIOtQHiByQXeg1fgYj4rQkOTxjzJJPQsXnJASL1SAJ5O1uab2mPo PUAM/wt4fFzbAKH1Wffza77MMKfKF+Jkg0Qt7+1fG7vPBCi0gCm7UtScaMwI5jpkxUcP C1Vg== MIME-Version: 1.0 X-Received: by 10.180.74.134 with SMTP id t6mr142776wiv.56.1376527319966; Wed, 14 Aug 2013 17:41:59 -0700 (PDT) Received: by 10.217.48.129 with HTTP; Wed, 14 Aug 2013 17:41:59 -0700 (PDT) In-Reply-To: References: Date: Wed, 14 Aug 2013 17:41:59 -0700 Message-ID: From: Dave Taht To: Naeem Khademi Content-Type: multipart/alternative; boundary=f46d043c820cee2b9a04e3f1bd43 Cc: "iccrg@irtf.org" , "aqm@ietf.org" , bloat Subject: Re: [Bloat] [iccrg] ECN support for PIE AQM in Linux X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Aug 2013 00:42:02 -0000 --f46d043c820cee2b9a04e3f1bd43 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable The pie patches that I was using until recently are here: http://snapon.lab.bufferbloat.net/~cero2/deb/patches/ Stephen hemminger and I cleaned up the original pie drop according to KernelStyle in multiple ways. There is a rounding error problem in setting the target value (we'd recomended they switch to ktime rather than jiffies) that I either added or was in there in the first place.... and we fixed a couple generic bugs... In addition to adding ecn support, we also added congestion notification to (a la the linux red and fq_codel algorithms) to provide lossless feedback into the host tcp stack. (this is, incidentally, 1 line of code) This optimization made it possible to do comparisons on host <-> host tests between these qdiscs, with no router in-between. Syntactically the iproute2 patches could use identical syntax for time based values as the codel iproute2 patches. Haven't got around to that. (not my job, really, to improve cisco's code) Now, I only now - today! - just noticed that the new pie code at cisco's site seems *substantially* different from the older pie code the above was based on, in that it no longer has an optimization for not dropping smaller packets. (bytemode) This is going to invalidate most previous benchmarks of pie that I know of, including all of mine, and most, if not all, of cablelabs'. Sigh. I will try to refresh my patches and update the lab over the next week or so. On Wed, Aug 14, 2013 at 2:17 PM, Naeem Khademi wro= te: > Hi Vijay > > This code implements basic ECN capability for PIE meaning that it > would CE-mark packets that would be early-dropped otherwise. I have > sanity-checked the code (e.g. successful ECN marking and > receiver/sender reaction). We're now in process of conducting larger > set of experiments with PIE w/wo ECN that will eventually be published > as we move forward. > > Cheers, > Naeem > > On Wed, Aug 14, 2013 at 8:27 PM, Vijay Subramanian > wrote: > > Naeem, > > > > Thanks for testing and the contribution! We have ECN support in our > current > > code-under-development thanks to earlier help from Dave Taht but I will > > merge your changes as appropriate and > > submit it back for review. > > > > I will take a look at your code soon. Do you also have any test results > > which you can share? > > > > Thanks again, > > Vijay > > > > > > On 14 August 2013 07:05, Naeem Khademi wrote: > >> > >> Hi > >> > >> The already-existing PIE Linux code maintained at > >> ftp://ftpeng.cisco.com/pie/ does not support ECN. Studying the > interaction > >> of ECN and AQM algos is probably of interest of some of us. I have > added ECN > >> support to PIE Linux code and have given it some basic sanity tests. > >> > >> The modified code is available at > >> http://heim.ifi.uio.no/naeemk/research/PIE/ > >> > >> I would appreciate any feedback. > >> > >> Regards, > >> Naeem > >> > >> > >> > >> _______________________________________________ > >> iccrg mailing list > >> iccrg@irtf.org > >> https://www.irtf.org/mailman/listinfo/iccrg > >> > > > _______________________________________________ > iccrg mailing list > iccrg@irtf.org > https://www.irtf.org/mailman/listinfo/iccrg > --=20 Dave T=E4ht Fixing bufferbloat with cerowrt: http://www.teklibre.com/cerowrt/subscribe.html --f46d043c820cee2b9a04e3f1bd43 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
The pie patches that I was using until recently are here:<= br><= div> Stephen hemminger and I cleaned up the original pie drop according to Kerne= lStyle in multiple ways. There is a rounding error problem in setting the t= arget value
(we'd recomended they switch to ktime rather= than jiffies) that I either added or was in there in the first place.... a= nd we fixed a couple generic bugs...

In addition to adding ecn support, we also added congestion = notification to (a la the linux red and fq_codel algorithms) to provide los= sless feedback into the host tcp stack. (this is, incidentally, 1 line of c= ode) This optimization made it possible to do comparisons on host <->= host tests between these qdiscs, with no router in-between.

Syntactically the iproute2 patches could use identical synta= x for time based values as the codel iproute2 patches. Haven't got arou= nd to that. (not my job, really, to improve cisco's code)

Now, I only now - today! - just noticed that the new pie code at cisco= 's site seems *substantially* different from the older pie code the abo= ve was based on, in that it no longer has an optimization for not dropping = smaller packets. (bytemode) This is going to invalidate most previous bench= marks of pie that I know of, including all of mine, and most, if not all, o= f cablelabs'. Sigh.

I will try to refresh my patches and update the lab over the= next week or so.

=

On Wed, Aug 14, 2013 at 2:17 PM, Naeem K= hademi <naeem.khademi@gmail.com> wrote:
Hi Vijay

This code implements basic ECN capability for PIE meaning that it
would CE-mark packets that would be early-dropped otherwise. I have
sanity-checked the code (e.g. successful ECN marking and
receiver/sender reaction). We're now in process of conducting larger set of experiments with PIE w/wo ECN that will eventually be published
as we move forward.

Cheers,
Naeem

On Wed, Aug 14, 2013 at 8:27 PM, Vijay Subramanian
<subramanian.vijay@gmail.= com> wrote:
> Naeem,
>
> Thanks for testing and the contribution! We have ECN support in our cu= rrent
> code-under-development thanks to earlier help from Dave Taht but I wil= l
> merge your changes as appropriate and
> submit it back for review.
>
> I will take a look at your code soon. Do you also have any test result= s
> which you can share?
>
> Thanks again,
> Vijay
>
>
> On 14 August 2013 07:05, Naeem Khademi <naeem.khademi@gmail.com> wrote:
>>
>> Hi
>>
>> The already-existing PIE Linux code maintained at
>> ftp://ft= peng.cisco.com/pie/ does not support ECN. Studying the interaction
>> of ECN and AQM algos is probably of interest of some of us. I have= added ECN
>> support to PIE Linux code and have given it some basic sanity test= s.
>>
>> The modified code is available at
>> http://heim.ifi.uio.no/naeemk/research/PIE/
>>
>> I would appreciate any feedback.
>>
>> Regards,
>> Naeem
>>
>>
>>
>> _______________________________________________
>> iccrg mailing list
>> iccrg@irtf.org
>> https://www.irtf.org/mailman/listinfo/iccrg
>>
>
_______________________________________________
iccrg mailing list
iccrg@irtf.org
h= ttps://www.irtf.org/mailman/listinfo/iccrg



--
Dave T=E4ht=

Fixing bufferbloat with cerowrt: http://www.teklibre.com/cerowrt/= subscribe.html=20
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