From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-x233.google.com (mail-wi0-x233.google.com [IPv6:2a00:1450:400c:c05::233]) (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 40BBA21F181 for ; Tue, 18 Mar 2014 09:03:03 -0700 (PDT) Received: by mail-wi0-f179.google.com with SMTP id f8so3913249wiw.12 for ; Tue, 18 Mar 2014 09:03:01 -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=7RUTy459iX83kPp4h7pkDxyTCfoansj32j+PVw+mr24=; b=QbNdGxzbgxSQhioBSQpi2IH9KR6dTXgo6+m9MVfyD3kVz0DFsg2GN/rySwTt/XI6Nc mjLXyIVpVdIOXZk/KODdUPK4id/j6cdJsFlakvxMBxpQ3r/Hed7ZJZlTvTFksraAbVNx 9FlQiecQbz9B9KOY7DgoZ4e5/xKd9gGIkP33XNSH3QPhCK8ErmOlW4mH8vTI3J3STj7j lhk2ddJbOMnCzY1K34nFEkoYEhzF/j+5Tu5S4rertsqOuX8cgl5y5Kv6/1ZxfRoPLUbq Tt4q1lCxCgTIKINTjzB9Y7vLzXXKKW8I0zDpYzhAEG03ihhxn3G5zjVAzlBNJ0tPOwXd tcFQ== MIME-Version: 1.0 X-Received: by 10.194.187.50 with SMTP id fp18mr589039wjc.89.1395158581084; Tue, 18 Mar 2014 09:03:01 -0700 (PDT) Received: by 10.216.8.1 with HTTP; Tue, 18 Mar 2014 09:03:01 -0700 (PDT) In-Reply-To: <53286AF2.3010203@redhat.com> References: <20140318161658.619158b9@redhat.com> <53286AF2.3010203@redhat.com> Date: Tue, 18 Mar 2014 12:03:01 -0400 Message-ID: Subject: Re: Linux SCTP: what kind of performance should I expect from netperf? From: Dave Taht To: Daniel Borkmann Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: bloat-devel X-BeenThere: bloat-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: "Developers working on AQM, device drivers, and networking stacks" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 18 Mar 2014 16:03:03 -0000 On Tue, Mar 18, 2014 at 11:49 AM, Daniel Borkmann wro= te: > On 03/18/2014 04:16 PM, Jesper Dangaard Brouer wrote: >> >> >> Hi Daniel, >> >> Can you give some input on this thread? >> >> On Tue, 18 Mar 2014 10:53:40 -0400 Dave Taht wrote= : >> >>> I was curious about sctp's performance characteristics on >>> AQM'd systems... so >>> I built netperf with sctp support, and ran a couple tests on >>> kernel 3.11... >>> >>> +1: SCTP appears to work over IPv6 >>> -1: Throughput is terrible > > > Yes, performance sucks so far (it's a known problem) and > we need to work on it ... ;-) I want to make clear that I don't know diddly about SCTP. I DO grok TCP fairly well... I got interested in sctp again after hearing a proposal to make it easier to fq chunks. > I presume one reason here could be as well that you need to > do crc32c checksumming on software (what does perf say?). Well what I think I see is sctp not opening up a window for packets in flight (as tcp would with cwnd), and basically ping-ponging sends and acks over the 14ms RTT: capture here http://snapon.lab.bufferbloat.net/~d/sctp/ One of my concerns with all the tcp optimization work over the last 3 years was that it might have broken other protocols and stuff that plugged into the congestion control api for Linux. For example, my ledbat kernel module behaves similarly, never getting out of slow start. But not having a test for sctp in general (I used netperf, is there a bette= r?). So if SCTP not ramping up is a known problem I can go back to scratching my head at the ledbat code. I WAS quite delighted to see SCTP "just work" over ipv6. :) > > >>> d@nuc:~/git/netperf$ netperf -6 -H snapon.lab.bufferbloat.net -t >>> SCTP_STREAM_MANY >>> SCTP 1-TO-MANY STREAM TEST from ::0 (::) port 0 AF_INET6 to >>> snapon.lab.bufferbloat.net () port 0 AF_INET6 : demo >>> Recv Send Send >>> Socket Socket Message Elapsed >>> Size Size Size Time Throughput >>> bytes bytes bytes secs. 10^6bits/sec >>> >>> 212992 212992 4096 10.00 0.31 >>> d@nuc:~/git/netperf$ netperf -6 -H snapon.lab.bufferbloat.net -t >>> TCP_MAERTS >>> MIGRATED TCP MAERTS TEST from ::0 (::) port 0 AF_INET6 to >>> snapon.lab.bufferbloat.net () port 0 AF_INET6 : demo >>> Recv Send Send >>> Socket Socket Message Elapsed >>> Size Size Size Time Throughput >>> bytes bytes bytes secs. 10^6bits/sec >>> >>> 87380 16384 16384 10.00 7.65 --=20 Dave T=E4ht Fixing bufferbloat with cerowrt: http://www.teklibre.com/cerowrt/subscribe.= html