From owner-freebsd-net@FreeBSD.ORG Thu Apr 19 21:17:42 2012 Return-Path: Delivered-To: net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 761A0106567A; Thu, 19 Apr 2012 21:17:42 +0000 (UTC) (envelope-from kmacybsd@gmail.com) Received: from mail-gy0-f182.google.com (mail-gy0-f182.google.com [209.85.160.182]) by mx1.freebsd.org (Postfix) with ESMTP id 042098FC0A; Thu, 19 Apr 2012 21:17:41 +0000 (UTC) Received: by ghrr20 with SMTP id r20so5827735ghr.13 for ; Thu, 19 Apr 2012 14:17:41 -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 :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=WDjnKcnbDW84Qn4y0ukwCVgwaiqViy2MULkLUVZKz20=; b=oTQRdNkxDlPY+/1+ronDP5n1m7rYDR8Ya75r2zRPsOx5PpmyePMtJVsbToGPARET/o jQQhdecLSXZIkGWYXO1dbotZ/MZUobnKnhR1Li+uQkaIeJ1YDmzKdPRpFlGdU4LEdber eMYSgs378lrSKBra0hHP/KJIKw3ER2HueceiCSX2BkTToZBTddSoZsz0UbO1rfricB9d w+JkEhM5YIVBAtnkSVW+bi3V934WMgsI/OMh+WZ+O/pLZG0zkeUWwHhrmCAkyyfuv1+m EtCP04aTxOr3RuarjdXEBPf/J4JEVo2f6PcM92lDHN4BsFYE+siBAEvjr08XObKenm1R XJKA== MIME-Version: 1.0 Received: by 10.50.194.232 with SMTP id hz8mr3932371igc.38.1334870261345; Thu, 19 Apr 2012 14:17:41 -0700 (PDT) Sender: kmacybsd@gmail.com Received: by 10.50.129.39 with HTTP; Thu, 19 Apr 2012 14:17:41 -0700 (PDT) In-Reply-To: <4F907FB4.3080400@freebsd.org> References: <20120419133018.GA91364@onelab2.iet.unipi.it> <4F907011.9080602@freebsd.org> <20120419204622.GA94904@onelab2.iet.unipi.it> <4F907FB4.3080400@freebsd.org> Date: Thu, 19 Apr 2012 23:17:41 +0200 X-Google-Sender-Auth: q7xbaDuXNxDADDM4ozkcC7eXqE8 Message-ID: From: "K. Macy" To: Andre Oppermann Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Cc: Luigi Rizzo , current@freebsd.org, net@freebsd.org Subject: Re: Some performance measurements on the FreeBSD network stack X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 19 Apr 2012 21:17:42 -0000 >> This only helps if your flows aren't hitting the same rtentry. >> Otherwise you still convoy on the lock for the rtentry itself to >> increment and decrement the rtentry's reference count. > > > The rtentry lock isn't obtained anymore. =A0While the rmlock read > lock is held on the rtable the relevant information like ifp and > such is copied out. =A0No later referencing possible. =A0In the end > any referencing of an rtentry would be forbidden and the rtentry > lock can be removed. =A0The second step can be optional though. Can you point me to a tree where you've made these changes? >>> i was wondering, is there a way (and/or any advantage) to use the >>> fastforward code to look up the route for locally sourced packets ? >>> >> >> If the number of peers is bounded then you can use the flowtable. Max >> PPS is much higher bypassing routing lookup. However, it doesn't scale >> to arbitrary flow numbers. > > > In theory a rmlock-only lookup into a default-route only routing > table would be faster than creating a flow table entry for every > destination. =A0It a matter of churn though. =A0The flowtable isn't > lockless in itself, is it? It is. In a steady state where the working set of peers fits in the table it should be just a simple hash of the ip and then a lookup. -Kip --=20 =A0 =A0=93The real damage is done by those millions who want to 'get by.' The ordinary men who just want to be left in peace. Those who don=92t want their little lives disturbed by anything bigger than themselves. Those with no sides and no causes. Those who won=92t take measure of their own strength, for fear of antagonizing their own weakness. Those who don=92t like to make waves=97or enemies. =A0 =A0Those for whom freedom, honour, truth, and principles are only literature. Those who live small, love small, die small. It=92s the reductionist approach to life: if you keep it small, you=92ll keep it under control. If you don=92t make any noise, the bogeyman won=92t find you. =A0 =A0But it=92s all an illusion, because they die too, those people who roll up their spirits into tiny little balls so as to be safe. Safe?! >From what? Life is always on the edge of death; narrow streets lead to the same place as wide avenues, and a little candle burns itself out just like a flaming torch does. =A0 =A0I choose my own way to burn.=94 =A0 =A0Sophie Scholl