From owner-freebsd-stable@FreeBSD.ORG Mon Jul 24 19:23:43 2006 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0150216A4DD for ; Mon, 24 Jul 2006 19:23:43 +0000 (UTC) (envelope-from marcelo@registro.br) Received: from clone.registro.br (clone.registro.br [200.160.2.4]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9A03A43D45 for ; Mon, 24 Jul 2006 19:23:42 +0000 (GMT) (envelope-from marcelo@registro.br) Received: by clone.registro.br (Postfix, from userid 1014) id E387A2A4F8; Mon, 24 Jul 2006 16:23:40 -0300 (BRT) Date: Mon, 24 Jul 2006 16:23:40 -0300 From: Marcelo Gardini do Amaral To: Ed Maste Message-ID: <20060724192340.GA51092@registro.br> References: <20060711190908.GC69272@registro.br> <20060720023856.GA65960@sandvine.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060720023856.GA65960@sandvine.com> User-Agent: Mutt/1.4.2.1i Cc: freebsd-stable@freebsd.org Subject: Re: How to setup polling on 'bge' interface X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 24 Jul 2006 19:23:43 -0000 > A few points: > > - Polling and SMP are compatible in 6.1. In fact, they were compatible > in earlier versions too; basically it's just the compile-time check > that had to be "fixed." > > - You may have to adjust some parameters in the kern.polling sysctl > tree - specifically, kern.polling.burst_max, kern.polling.each_burst > and kern.polling.user_frac might need tweaking. > > - The polling feedback algorithm does not work very well if your > workload is focused largely on per-packet tasks (such as routing or > bridging). You'll find that there is still idle CPU time at the > point you start dropping packets. I have some work in progress to > address this, but it's not yet committed. > > - Polling's major advantage is the avoidance of livelock on UP systems, > and not improved performance. > > What level of traffic are you putting through this box? Is it routing/ > bridging, or an endpoint like a web server? It's an endpoint with no more than 1k pkts/s in normal condition. Almost all traffic is UDP. I really intend to avoid locking my system in a high load situation. -- Att., Marcelo Gardini