From owner-freebsd-stable@FreeBSD.ORG Tue Jun 27 08:43:51 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 F12E716A40A; Tue, 27 Jun 2006 08:43:51 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from mail04.syd.optusnet.com.au (mail04.syd.optusnet.com.au [211.29.132.185]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3B2D343D5A; Tue, 27 Jun 2006 08:43:51 +0000 (GMT) (envelope-from peterjeremy@optushome.com.au) Received: from turion.vk2pj.dyndns.org (c220-239-19-236.belrs4.nsw.optusnet.com.au [220.239.19.236]) by mail04.syd.optusnet.com.au (8.12.11/8.12.11) with ESMTP id k5R8hiTr030722 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO); Tue, 27 Jun 2006 18:43:45 +1000 Received: from turion.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by turion.vk2pj.dyndns.org (8.13.6/8.13.6) with ESMTP id k5R8hhj6001177; Tue, 27 Jun 2006 18:43:43 +1000 (EST) (envelope-from peter@turion.vk2pj.dyndns.org) Received: (from peter@localhost) by turion.vk2pj.dyndns.org (8.13.6/8.13.6/Submit) id k5R8hhBx001176; Tue, 27 Jun 2006 18:43:43 +1000 (EST) (envelope-from peter) Date: Tue, 27 Jun 2006 18:43:43 +1000 From: Peter Jeremy To: Dmitry Pryanishnikov Message-ID: <20060627084343.GD714@turion.vk2pj.dyndns.org> References: <20060626100949.G24406@fledge.watson.org> <20060626081029.L1114@ganymede.hub.org> <20060626140333.M38418@fledge.watson.org> <20060626235355.Q95667@atlantis.atlantis.dp.ua> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="u65IjBhB3TIa72Vp" Content-Disposition: inline In-Reply-To: <20060626235355.Q95667@atlantis.atlantis.dp.ua> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.11 Cc: freebsd-acpi@freebsd.org, freebsd-stable@freebsd.org Subject: Re: FreeBSD 6.x CVSUP today crashes with zero load ... 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: Tue, 27 Jun 2006 08:43:52 -0000 --u65IjBhB3TIa72Vp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, 2006-Jun-27 00:01:08 +0300, Dmitry Pryanishnikov wrote: >On Mon, 26 Jun 2006, Robert Watson wrote: >>I think this is a useful activity, especially if you've already run=20 >>extensive memory testing on the box. If you haven't yet done that, I=20 >>encourage you to take a break from buildworld's and make sure the memory= =20 >>tests pass. I spent several months on and off trying to track down a bug = a=20 >>few years ago, which turned out to be a one bit error in memory on the=20 >>box. It would appear and > > This is precisely the task which hardware ECC solves: to correct any=20 > single-bit memory error and to detect 2-bit and most of several-bit error= s. Parity will detect any odd number of bits in error. ECC can typically correct correct one bit and detect 2 or any odd number of errors. Note that ECC only checks the path between the RAM and DRAM controller (eg northbridge). You can also get errors between the northbridge and the CPU (including the cache). Some caches (eg Alpha) have parity to help here. Mainframes typically have ECC or parity on _all_ datapaths (including through the ALU) to catch those errors. --=20 Peter Jeremy --u65IjBhB3TIa72Vp Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (FreeBSD) iD8DBQFEoO++/opHv/APuIcRAjh4AKCpQxE5JR5nY4oFl1nFMojyCFrQhACfXFKM kJfxbJmKb6+KADP0vQM6OzM= =Rj5H -----END PGP SIGNATURE----- --u65IjBhB3TIa72Vp--