From owner-freebsd-amd64@FreeBSD.ORG Sun Feb 22 22:51:03 2004 Return-Path: Delivered-To: freebsd-amd64@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3D59616A4CE for ; Sun, 22 Feb 2004 22:51:03 -0800 (PST) Received: from canning.wemm.org (canning.wemm.org [192.203.228.65]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3493D43D2D for ; Sun, 22 Feb 2004 22:51:03 -0800 (PST) (envelope-from peter@evilpete.dyndns.org) Received: from fw.wemm.org (canning.wemm.org [192.203.228.65]) by canning.wemm.org (Postfix) with ESMTP id 0D9FC2A8E7 for ; Sun, 22 Feb 2004 22:51:03 -0800 (PST) (envelope-from peter@overcee.wemm.org) Received: from overcee.wemm.org (unknown [10.0.0.3]) by fw.wemm.org (Postfix) with ESMTP id 78D7B2C1AC for ; Sun, 22 Feb 2004 22:51:02 -0800 (PST) (envelope-from peter@overcee.wemm.org) Received: from overcee.wemm.org (localhost [127.0.0.1]) by overcee.wemm.org (8.12.11/8.12.10) with ESMTP id i1N6p24m037029; Sun, 22 Feb 2004 22:51:02 -0800 (PST) (envelope-from peter@overcee.wemm.org) Received: from localhost (localhost [[UNIX: localhost]]) by overcee.wemm.org (8.12.11/8.12.10/Submit) id i1N6p2GD037028; Sun, 22 Feb 2004 22:51:02 -0800 (PST) (envelope-from peter) From: Peter Wemm To: James Van Artsdalen Date: Sun, 22 Feb 2004 22:51:02 -0800 User-Agent: KMail/1.6 References: <200402230501.i1N51NB0049544@bigtex.jrv.org> <200402222147.13520.peter@wemm.org> <200402230633.i1N6X0DB069241@bigtex.jrv.org> In-Reply-To: <200402230633.i1N6X0DB069241@bigtex.jrv.org> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200402222251.02612.peter@wemm.org> cc: freebsd-amd64@freebsd.org Subject: Re: Opteron ECC X-BeenThere: freebsd-amd64@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Porting FreeBSD to the AMD64 platform List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 Feb 2004 06:51:03 -0000 On Sunday 22 February 2004 10:33 pm, James Van Artsdalen wrote: > > From: Peter Wemm > > Date: Sun, 22 Feb 2004 21:47:13 -0800 > > > > On Sunday 22 February 2004 09:01 pm, James Van Artsdalen wrote: > > > It turns out that AMD has published its Opteron errata sheet and > > > errata item 101 appears to be the issue: a bug in the Opteron > > > means you can't have both "node interleave" and ECC scrubbing on > > > at the same time. > > > > Oh my, thats bit of a stinker. Do you recall which steppings this > > applies to? > > > > BTW; I suspect you might find that node interleave is more useful > > (speed wise) than ecc background scrubbing. But I guess that > > depends on what you want.. If you're trying to wring every bit of > > performance out of it, pick node interleave over scrubbing. On the > > other hand, if you'd perfer to have the system constantly checking > > that the ECC ram is ok and you're not so worried about speed, then > > pick scrubbing. > > The errata list is here: > http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_do >cs/25759.pdf > > Bug 101 affects both B3 and C0 steppings. > > A word for people reading processor errata for the first time: here's > a comment I made on another list: > > This errata list may look gruesome to those not used to such > things, but it's not bad at all. I dealt with processor errata > lists from Intel for years as a PC designer - the > double-secret-NDA lists - and this is par for the course, perhaps > even cleaner than usual. Yes. I've read the public ("these are the ones we admit to") lists from intel and those were scary enough. > It might not hurt to add a line of code to the kernel to check for > these steppings, node interleave and scrubbing, and print a warning > if all three are met. Yes. I think a warning is in order, at the very least. Checking for errata and steppings has been on my todo list for a while. At least this time I've got around to printing the errata list. :-) -- Peter Wemm - peter@wemm.org; peter@FreeBSD.org; peter@yahoo-inc.com "All of this is for nothing if we don't go to the stars" - JMS/B5