From owner-freebsd-hackers@FreeBSD.ORG Mon Sep 23 04:42:35 2013 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id D0597AD1; Mon, 23 Sep 2013 04:42:35 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-wg0-x236.google.com (mail-wg0-x236.google.com [IPv6:2a00:1450:400c:c00::236]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 836B62B50; Mon, 23 Sep 2013 04:42:34 +0000 (UTC) Received: by mail-wg0-f54.google.com with SMTP id m15so2690852wgh.9 for ; Sun, 22 Sep 2013 21:42:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=P2w1WbOvUNizXn7ZsZS2TBooYqeg4cGtYAdYuHYhYXM=; b=QOwrZB5l04e+6jyPEqzodo92zbc+lgK+Acasb9IebLx+0pMt++4YSkD1Y69XGeJN47 O5q78g4joGcHZCXb4Sn5q/+b8pgFZzoqCX3HbDHnjWLGeLaeIzvsMPRMJ2QjUd+DPgI4 kQeWEDgL2puChSMNZNc0GP+Yrc5jMlRtlX16RU2tYuX0zwZ74ydipyKtRv7zVzP5SD2i QNIdpI9rcwdFWjQBTbPx24KSQcZX+2ykEAL8KEFOJpfUIDs6zPXLWk25mKbutnQm3DZW SKWgHGVY1h0IpgLyJvTbTq+B4vDL1URAj6tEcZU0Ne9IVvTY0BRjmiX7vQU/6ObMDegy GoVA== MIME-Version: 1.0 X-Received: by 10.180.10.136 with SMTP id i8mr11840167wib.46.1379911352875; Sun, 22 Sep 2013 21:42:32 -0700 (PDT) Sender: adrian.chadd@gmail.com Received: by 10.216.73.133 with HTTP; Sun, 22 Sep 2013 21:42:32 -0700 (PDT) In-Reply-To: <523F4F14.9090404@yandex-team.ru> References: <521E41CB.30700@yandex-team.ru> <523F4F14.9090404@yandex-team.ru> Date: Sun, 22 Sep 2013 21:42:32 -0700 X-Google-Sender-Auth: Xk5o-T54T2C85UHlUNeXvbPizgo Message-ID: Subject: Re: Network stack changes From: Adrian Chadd To: "Alexander V. Chernikov" Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 Cc: Luigi Rizzo , Andre Oppermann , "freebsd-hackers@freebsd.org" , FreeBSD Net , "Andrey V. Elsukov" , Gleb Smirnoff , "freebsd-arch@freebsd.org" X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 Sep 2013 04:42:36 -0000 Hi! On 22 September 2013 13:12, Alexander V. Chernikov wrote: > I'm thinking the same way, but we're stuck with 'forwarding lookup' due > to problem with egress interface pointer, as I mention earlier. However it > is interesting to see how much it helps, regardless of locking. > > Currently I'm thinking that we should try to change radix to something > different (it seems that it can be checked fast) and see what happened. > Luigi's performance numbers for our radix are too awful, and there is a > patch implementing alternative trie: > http://info.iet.unipi.it/~**luigi/papers/20120601-dxr.pdf > http://www.nxlab.fer.hr/dxr/**stable_8_20120824.diff > > So, I can make educated guesses about why this is better for forwarding workloads. I'd like to characterize it though. So, what's it doing that's better? better locking? better caching behaviour? less memory lookups? etc. Thanks, -adrian