From owner-freebsd-stable@FreeBSD.ORG Fri Oct 3 18:02:43 2008 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6ED48106568C for ; Fri, 3 Oct 2008 18:02:43 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from pi.codefab.com (pi.codefab.com [199.103.21.227]) by mx1.freebsd.org (Postfix) with ESMTP id 428568FC1A for ; Fri, 3 Oct 2008 18:02:43 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from localhost (localhost [127.0.0.1]) by pi.codefab.com (Postfix) with ESMTP id DFE545D03; Fri, 3 Oct 2008 13:46:33 -0400 (EDT) X-Virus-Scanned: amavisd-new+ClamAV at codefab.com Received: from [192.168.1.3] (pool-71-190-72-228.nycmny.east.verizon.net [71.190.72.228]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by pi.codefab.com (Postfix) with ESMTPSA id ACE105CEF; Fri, 3 Oct 2008 13:46:31 -0400 (EDT) Message-ID: <48E65A6E.4090203@mac.com> Date: Fri, 03 Oct 2008 13:46:22 -0400 From: Chuck Swiger User-Agent: Thunderbird 2.0.0.17 (Windows/20080914) MIME-Version: 1.0 To: Pieter de Goeje References: <48E62ABA.6070901@kkip.pl> <200810031706.11941.pdegoeje@service2media.com> In-Reply-To: <200810031706.11941.pdegoeje@service2media.com> Content-Type: text/plain; charset=ISO-8859-2; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-stable@freebsd.org, Bartosz Stec Subject: Re: fxp performance with POLLING 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: Fri, 03 Oct 2008 18:02:43 -0000 Pieter de Goeje wrote: > On Friday 03 October 2008, Bartosz Stec wrote: >> Hello again :) >> >> With POLLING enabled I experience about 10%-25% performance drop when >> copying files over network. Tested with both SAMBA and NFS. Is it normal? > > Yes. You don't want to use polling unless you set kern.hz to 10000 or > something in that range. HZ = 1000 or 2000 is fine for most purposes, at least up through T3 level bandwidth. For a home LAN or small business office of a half-dozen machines using DSL/Cable (~ 1-5 MBs up), even a P2-300 or VIA C3 600 at HZ=250 works OK as a firewall/router. The main thing that using polling does is that it adds a reasonably fixed amount of latency (ie, the poll interval) but gives solid processing performance even under heavy load, just as you say: > If you have a NIC with interrupt moderation, polling > should almost never be necessary. Note that polling can still be useful for > routers, because it allows you to have a much more responsive system even > when handling heavy network traffic. Note that he's got the link0 flag going, so that should mean he's using firmware with the fxp NIC which does interrupt moderation. Regards, -- -Chuck