From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-we0-x22c.google.com (mail-we0-x22c.google.com [IPv6:2a00:1450:400c:c03::22c]) (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 32CD721F1F1 for ; Tue, 15 Apr 2014 18:23:07 -0700 (PDT) Received: by mail-we0-f172.google.com with SMTP id t61so10300056wes.31 for ; Tue, 15 Apr 2014 18:23:05 -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=5GxcDEbDZQvzvTDoWs0BLY96VWi1ppIPm66ockYtZDM=; b=uL6zssrjOP9myWzDLQQG7c3HnqKhFRLtA1PxvrWaMDGQu1Sry0jEyHtFGQfCwbIwBD QSUJjKfsKC6BXuxGGFCzH8Oq/npD2Ahgjc/qTf73KP+RUHbvxRsth4Yj6grjm7i924Z0 PICKHlrqNsb6afhvagKfydfqn7eOGWKDcl7UPHf5FGRBerYm4xYi4da2M6GMv426ebdk 1FwXxGJ+1dsbof4bUJOCw2l9adSs2gcqkGxVxiXrkmA9MTdgIin0r3JnwpiAL5Ud+gjg 8s3+d19XM4tyY+mobImVpyi5G8CItwut4dn4b6s/EuXVNzo9yntLUxeS97YHBsLJr5Yi fitw== MIME-Version: 1.0 X-Received: by 10.194.175.70 with SMTP id by6mr4184749wjc.3.1397611385382; Tue, 15 Apr 2014 18:23:05 -0700 (PDT) Received: by 10.216.177.10 with HTTP; Tue, 15 Apr 2014 18:23:05 -0700 (PDT) In-Reply-To: References: <20140318161658.619158b9@redhat.com> <53286AF2.3010203@redhat.com> Date: Tue, 15 Apr 2014 18:23:05 -0700 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=UTF-8 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: Wed, 16 Apr 2014 01:23:07 -0000 On Tue, Mar 18, 2014 at 9:03 AM, Dave Taht wrote: > On Tue, Mar 18, 2014 at 11:49 AM, Daniel Borkmann w= rote: >> On 03/18/2014 04:16 PM, Jesper Dangaard Brouer wrote: >>> >>> >>> Hi Daniel, >>> >>> Can you give some input on this thread? It appears I despaired of SCTP's performance too early, according to this commit, it just got vastly improved: https://git.kernel.org/cgit/linux/kernel/git/davem/net.git/commit/?id=3D362= d52040c71f6e8d8158be48c812d7729cb8df1 way to go daniel! Have to write some tests for it now! I do wish someone could get the ledbat linux kernel module up to parity wit= h at least the osx implementation and get it mainlined. https://github.com/silviov/TCP-LEDBAT >>> >>> On Tue, 18 Mar 2014 10:53:40 -0400 Dave Taht wrot= e: >>> >>>> 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 bet= ter?). > > 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 > > > > -- > Dave T=C3=A4ht > > Fixing bufferbloat with cerowrt: http://www.teklibre.com/cerowrt/subscrib= e.html --=20 Dave T=C3=A4ht NSFW: https://w2.eff.org/Censorship/Internet_censorship_bills/russell_0296_= indecent.article