From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-x235.google.com (mail-oi0-x235.google.com [IPv6:2607:f8b0:4003:c06::235]) (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 BF4E33B29E for ; Sun, 29 Oct 2017 11:38:39 -0400 (EDT) Received: by mail-oi0-x235.google.com with SMTP id m198so17638688oig.5 for ; Sun, 29 Oct 2017 08:38:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=XV+d3zxSbeg5RL/ZWrk3bD/2URk43eIgDqzqMQINFVI=; b=jBIqr7YqjFAtcuQfm4u9w0Tbd1Fo8EiOqpUBo+bBqcFkBbwMjBwYZ19cx8k5ImtB4k xMhgHYv2/A9PH5iSBkegUejkWKhM9e1YE7TN/fXIu8WRmNYxyEzb+crGDM7we0PHWkLz nMfm3j01RUKXWtzY0p/Qcid84X3/4FuCJA/bFY1Sn+OiMB7xye6WZ/O+aHGqREI0bh5d t6P/f13E6JGsFSEaysTZwBbxzFUpwLsRP29/VVcTOjLpi/T4wc92KrhuviZHui5OBru4 G1az19rXWFVV7KIOx4D6n2W35ZxOxA6A3rYsAQGpR8/pUsQYSCxVQtRdG/zm+L8UH7x6 Lx/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=XV+d3zxSbeg5RL/ZWrk3bD/2URk43eIgDqzqMQINFVI=; b=Xd+SaKAFWJ+9699jf54EgNT7zuC3I27sSaHf8EAy0LmRjCrAcBj/y1S6YwTt4JI0VB PS42byvdJSdP8Rl/t4kb4LgPCimv5L0KseQJtzaR8fzJaxnPZ3oIudGbW9N7Jn31LIRP 3cLRVUlF+/Wp6JarCtZ1yT7WDwNSXH15vEu8IoXQdG+W/grJQQ7m/mj1Cg0pRxcZuNCt hZljSEJvSgtRua5GOyG7ufJIN2toB3798ilybdluP4pOL5tXJ/QX0yIgzTrikKhYUdFW +n9Q4cME3RSaF+AfDOFQz1uCTZSAzgC5kXZScPGTOLNKSpqRTMm5fPvYcxB8uui5bfbT qqiQ== X-Gm-Message-State: AMCzsaXpgdl9AoX15GzWZ+xxGJoZRBAGwQd6y3pD3+oHQqeCNhlk2CO+ T1eG9ByXv1dF5Zt4iW9hEEBaZ/6aB36cgA/wABE= X-Google-Smtp-Source: ABhQp+RhM41vzZiYUxX/2sMO4FNECS/GUznJLTe6crBD1NlQRPBIfOvtuGL0uelmlSC2SE+sFW4YEPubzX+PNFRsIpc= X-Received: by 10.157.62.84 with SMTP id h20mr3573039otg.183.1509291519181; Sun, 29 Oct 2017 08:38:39 -0700 (PDT) MIME-Version: 1.0 Received: by 10.157.15.68 with HTTP; Sun, 29 Oct 2017 08:38:38 -0700 (PDT) In-Reply-To: References: From: Adrian Popescu Date: Sun, 29 Oct 2017 17:38:38 +0200 Message-ID: To: Jonathan Morton Cc: Cake List Content-Type: multipart/alternative; boundary="f403045e3824dd06c0055cb1502b" Subject: Re: [Cake] CAKE set-associative hashing X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 29 Oct 2017 15:38:39 -0000 --f403045e3824dd06c0055cb1502b Content-Type: text/plain; charset="UTF-8" Thank you Jonathan. I'm going over the code to learn more about CAKE. This set-associative hashing seems to be pretty useful. I'll ask more questions about the code as I try to understand it better. On Sun, Oct 29, 2017 at 12:14 PM, Jonathan Morton wrote: > Yes, in the same way as is caused by SFQ's periodic hash perturbation. > > However, in Cake this is a rare condition brought on by exceptional load; > it typically takes hundreds of bulk flows to get an unresolvable > collision. The use of AQM also means that the extent of reordering is > reduced due to shorter average queues. Most sane protocols, including > TCP-SACK, should cope fine. > > - Jonathan Morton > --f403045e3824dd06c0055cb1502b Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Thank you Jonathan. I'm going over the code to learn m= ore about CAKE. This set-associative hashing seems to be pretty useful. I&#= 39;ll ask more questions about the code as I try to understand it better.

On Sun, O= ct 29, 2017 at 12:14 PM, Jonathan Morton <chromatix99@gmail.com>= ; wrote:

Yes, in th= e same way as is caused by SFQ's periodic hash perturbation.

However, in Cake this is a rare condition brought on by exce= ptional load; it typically takes hundreds of bulk flows to get an unresolva= ble collision.=C2=A0 The use of AQM also means that the extent of reorderin= g is reduced due to shorter average queues.=C2=A0 Most sane protocols, incl= uding TCP-SACK, should cope fine.

- Jonathan Morton


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