From owner-freebsd-net@FreeBSD.ORG Wed Nov 21 01:19:14 2012 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 1028A9D1 for ; Wed, 21 Nov 2012 01:19:14 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-we0-f182.google.com (mail-we0-f182.google.com [74.125.82.182]) by mx1.freebsd.org (Postfix) with ESMTP id 8F0BE8FC13 for ; Wed, 21 Nov 2012 01:19:12 +0000 (UTC) Received: by mail-we0-f182.google.com with SMTP id u54so1888151wey.13 for ; Tue, 20 Nov 2012 17:19:12 -0800 (PST) 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; bh=vS84REOO+hCD1RWEnAOhAgkGhOnio++JC9Iyx10bED0=; b=Cc0ZEFoM/q/+xIMaTu03hsc2nVkWYskmY/oTASUz2DYJrr7fQqOK0oa5cFzbXljAM1 qpbOwI9EhYEO+JLc46qNGoD9mJLFmDOz8cllfljI1sxglaXa++V15HDDhAG78FAw5J7k jdaakBh+/FGe0gK2PNKQPWC7G8mQ09UlvPoGIGI6+T0/Fn3bXpu4c9SQp7TOs8xlaSRN TCzyD1y6Y8xwXSG/pfJesuQHINbTEGP5UbukPqeL1bGP57/uhUGqNE/NMFHTl29Q1DXh 3AhjtZHbJdWFdZ2bK0TWooB7sQhpBC8d1F9b//QmNeKhAU1BVSUaL5acrV8b1tG9obia /sMg== MIME-Version: 1.0 Received: by 10.216.200.160 with SMTP id z32mr72282wen.53.1353460752102; Tue, 20 Nov 2012 17:19:12 -0800 (PST) Sender: adrian.chadd@gmail.com Received: by 10.216.21.211 with HTTP; Tue, 20 Nov 2012 17:19:11 -0800 (PST) In-Reply-To: <832757660.33924.1353460119408@238ae4dab3b4454b88aea4d9f7c372c1.nuevasync.com> References: <1353448328.76219.YahooMailClassic@web121602.mail.ne1.yahoo.com> <50AC08EC.8070107@mu.org> <832757660.33924.1353460119408@238ae4dab3b4454b88aea4d9f7c372c1.nuevasync.com> Date: Tue, 20 Nov 2012 17:19:11 -0800 X-Google-Sender-Auth: jph2UMtMJBFGTexISmMzzmhYNmI Message-ID: Subject: Re: FreeBSD boxes as a 'router'... From: Adrian Chadd To: khatfield@socllc.net Content-Type: text/plain; charset=ISO-8859-1 Cc: Barney Cordoba , Jim Thompson , Alfred Perlstein , "freebsd-net@freebsd.org" X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Nov 2012 01:19:14 -0000 Ok, so since people are talking about it, and i've been knee deep in at least the older intel gige interrupt moderation - at maximum pps, how exactly is the interrupt moderation giving you a livelock scenario? The biggest benefit I found when doing some forwarding work a few years ago was to write a little daemon that actually sat there and watched the interrupt rates and packet drop rates per-interface - and then tuned the interrupt moderation parameters to suit. So at the highest pps rates I wasn't swamped with interrupts. I think polling here is hiding some poor choices in driver design and network stack design.. adrian