From owner-freebsd-stable@FreeBSD.ORG Wed Dec 14 23:17:49 2005 Return-Path: X-Original-To: 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 7911116A41F for ; Wed, 14 Dec 2005 23:17:49 +0000 (GMT) (envelope-from scottl@samsco.org) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.FreeBSD.org (Postfix) with ESMTP id B314143D55 for ; Wed, 14 Dec 2005 23:17:46 +0000 (GMT) (envelope-from scottl@samsco.org) Received: from [192.168.254.14] (imini.samsco.home [192.168.254.14]) (authenticated bits=0) by pooker.samsco.org (8.13.4/8.13.4) with ESMTP id jBENHdwY006972; Wed, 14 Dec 2005 16:17:39 -0700 (MST) (envelope-from scottl@samsco.org) Message-ID: <43A0A812.1060104@samsco.org> Date: Wed, 14 Dec 2005 16:17:38 -0700 From: Scott Long User-Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.7.7) Gecko/20050416 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Kevin Oberman References: <20051214222037.94FEF5D07@ptavv.es.net> In-Reply-To: <20051214222037.94FEF5D07@ptavv.es.net> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-1.4 required=3.8 tests=ALL_TRUSTED autolearn=failed version=3.1.0 X-Spam-Checker-Version: SpamAssassin 3.1.0 (2005-09-13) on pooker.samsco.org Cc: stable@freebsd.org Subject: Re: Odd performance problems after upgrade from 4.11 to 6.0-Stable 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: Wed, 14 Dec 2005 23:17:49 -0000 Kevin Oberman wrote: > I recently upgraded my last desktop system from 4.11-Stable to > 6.0-Stable. I did an update to 5.3 then to RELENG_5, > RELENG_6_0_0_RELEASE and on to RELENG6_0. > > This system has been updated regularly from the days of at least 4.1. > The hardware is a 1GHz PIII with an ICH2 chipset. 256 MB of memory. > > After the upgrade, the system performs poorly. Specifically, it seems to > be blocking on I/O. If I have a dump or bsdtar running, a CPU intensive > job produced minimal CPU utilization and little progress. The system is > 70% or more idle all of the time. X is particularly sluggish. Many times > the system will simply appear to be locked up for seconds at a time like > all of the I/O is synchronous and the entire system is blocking on GIANT > until the disk write finishes. A level 0 dump of the system drive piped > through gzip and over the network took about 10 hours. Now it is 17 > hours. My network link only ran at 3.4 Mbps (yes, that's bits, not > Bytes) over a 100 Mbps connection to the storage server. The rate was > much higher under 4.11. > > My attempts to track down the source of the problem simply failed. I > have examined my kernel configuration and found nothing out of the > ordinary. In fact, the the configuration varies from GENERIC only in > devices (both added and deleted), dropping 486 and 586 CPU code and a > larger SC_HISTORY. I have nothing in sysctl.conf and only enable DMA on > my ATAPI devices in loader.conf. I have confirmed that the disks are > running ATA100. > > Any suggestions on where to look? At this point I am baffled. The bufdaemon is probably causing some of the Giant contention. However, what it is contending with is the real question. Is your network driver and stack running MPSAFE? At least a 'dmesg' dump is needed here. Also, taking out CPU_I586 is usually a bad idea. It offers no performance penalties (unlike CPU_I386 and maybe CPU_I486), but enables things like optimized bcopy. Scott