From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-x22c.google.com (mail-oi0-x22c.google.com [IPv6:2607:f8b0:4003:c06::22c]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 64DE93B25E for ; Mon, 26 Sep 2016 15:30:44 -0400 (EDT) Received: by mail-oi0-x22c.google.com with SMTP id t83so219588063oie.3 for ; Mon, 26 Sep 2016 12:30:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=txe7XpSmYrvloR74VvkG/cYx8lxZWSZscyqhRVkrjuw=; b=EM89pC0YjW6xMhp7b9UJu6BVEwS848NVnIG95yzdxNF1JJeEQuaS9mmwE6e10QT255 CjwzHc0n9Nkhk4AR5IC7xrQT9aEHydimUOnAdHP3xquQj+5orr7V/O6KMuEa7MqYcot4 MvMceT9yef7XuPO3BO0+i9dFVETUPvTxXIKs8S4t3b5uXeRTxZDcX4ykkqdR+Y4+vqWy IlkBfsIDcqwew99Vz80XHLFb15V4tK4A3lCfQd1liz13k5wOCNXirHOQCHA5C99D20J6 xCPbxM3N28RDloebWDw5AEpUs4W5veUqrok8nU1p8uVM6MLHF6U46wYfg7lkOwq2Q+6n LRWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=txe7XpSmYrvloR74VvkG/cYx8lxZWSZscyqhRVkrjuw=; b=TSAZCW3wZG1yWuMb3ZMm2VWchFbXIRfTWPcZXe3a9spFA4pct19HiVfq/VF+A+8NO9 r/OmCZEsD3TmnfZhu8xWq4aueKAMisxie+tCTlRRgLJs6Xvn1cz5uk6gi80zJCBCec/r 8wBOHonT4614wRDrGfKC2zlpuB5DOungJMa+EVkRArgVtyZ79SAF6kkFnYwnXQ5B710u sNzZbFjcc5gVLyLkp6te5avEWBrrjWF26jPuiY24zPsTbaxIQSdeCVVU+rAonkUHx99J VWGV/WHRbPqIHosrt5qhvn14ZwpOYUzTn4cuvAmdLmUVcz3e0pTZdR2uSZX7vFgPmVbj 94IA== X-Gm-Message-State: AA6/9RlKy7qUcAgmiA/bQatWeLdVgzf7vK65r0KAI1XLiTGK4cQXZElgNqZ4GM+iTWM1Xn62CZsvf88wavXdyGjZ X-Received: by 10.202.6.68 with SMTP id 65mr8054668oig.32.1474918243771; Mon, 26 Sep 2016 12:30:43 -0700 (PDT) MIME-Version: 1.0 Received: by 10.202.182.65 with HTTP; Mon, 26 Sep 2016 12:30:13 -0700 (PDT) In-Reply-To: References: From: Neal Cardwell Date: Mon, 26 Sep 2016 15:30:13 -0400 Message-ID: To: Aaron Wood Cc: "cerowrt-devel@lists.bufferbloat.net" , Eric Dumazet , Yuchung Cheng Content-Type: text/plain; charset=UTF-8 Subject: Re: [Cerowrt-devel] BBR congestion control algorithm for TCP in net-next X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.20 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: Mon, 26 Sep 2016 19:30:44 -0000 On Mon, Sep 26, 2016 at 2:47 PM, Aaron Wood wrote: > Dumb question on this: The tcp_bbr_info struct for a socket can be > inspected at runtime through the ss utility or through a get socket opts > call, right? Yes, you can use either approach: (1) from code you can use TCP_CC_INFO socket option; there is sample code in the original kernel patch for TCP_CC_INFO: https://patchwork.ozlabs.org/patch/465806/ (2) from ss: if you download and build the net-next branch of the iproute2 package: http://git.kernel.org/cgit/linux/kernel/git/shemminger/iproute2.git/log/?h=net-next then you will get support to print out the main parameters for a BBR connection, eg: The patch with BBR support for ss is here: http://git.kernel.org/cgit/linux/kernel/git/shemminger/iproute2.git/commit/?h=net-next&id=2f0f9aef94129643133363b4503468cdccc481cc As the commit notes, the BBR output looks like: bbr:(bw:1.2Mbps,mrtt:18.965,pacing_gain:2.88672,cwnd_gain:2.88672) Hope that helps, neal > > -Aaron > > On Sat, Sep 17, 2016 at 11:34 AM, Maciej Soltysiak > wrote: >> >> Hi, >> >> Just saw this: https://patchwork.ozlabs.org/patch/671069/ >> >> Interested to see how BBR would play out with things like fq_codel or >> cake. >> >> "loss-based congestion control is unfortunately out-dated in today's >> networks. On >> today's Internet, loss-based congestion control causes the infamous >> bufferbloat problem" >> >> So, instead of waiting for packet loss they probe and measure, e.g. when >> doing slow start (here called STARTUP) they don't speed up until packet >> loss, but slow down before reaching estimated bandwidth level. >> >> Cake and fq_codel work on all packets and aim to signal packet loss early >> to network stacks by dropping; BBR works on TCP and aims to prevent packet >> loss. >> >> >> Best regards, >> Maciej >> >> >> _______________________________________________ >> Cerowrt-devel mailing list >> Cerowrt-devel@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/cerowrt-devel >> > > > _______________________________________________ > Cerowrt-devel mailing list > Cerowrt-devel@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/cerowrt-devel >