From owner-freebsd-current@FreeBSD.ORG Wed Jan 30 14:22:59 2008 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 57AD416A47D for ; Wed, 30 Jan 2008 14:22:59 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.freebsd.org (Postfix) with ESMTP id 31BC013C46E for ; Wed, 30 Jan 2008 14:22:59 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from zion.baldwin.cx (66-23-211-162.clients.speedfactory.net [66.23.211.162]) by elvis.mu.org (Postfix) with ESMTP id D74CB1A4D7C; Wed, 30 Jan 2008 06:22:57 -0800 (PST) From: John Baldwin To: freebsd-current@freebsd.org Date: Wed, 30 Jan 2008 08:49:57 -0500 User-Agent: KMail/1.9.7 References: <18328.45282.562906.708945@celery.zuhause.org> <18332.52845.956601.870334@celery.zuhause.org> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200801300849.58321.jhb@freebsd.org> Cc: Richard Todd Subject: Re: Weird performance behaviour in 7.0 X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Jan 2008 14:22:59 -0000 On Tuesday 29 January 2008 06:36:43 pm Richard Todd wrote: > bruce@zuhause.mn.org writes: > > > I'm curious, though, should I be worried about the memcontrol list > > entries that are listed as "set-by-firmware active bogus"? > > > > 0x0/0xf080000000 BIOS write-back set-by-firmware active bogus > > 0x80000000/0xf040000000 BIOS write-back set-by-firmware active bogus > > 0xc0000000/0xf010000000 BIOS write-back set-by-firmware active bogus > > 0xcf800000/0xf000800000 BIOS uncacheable set-by-firmware active bogus > > 0xcf700000/0xf000100000 BIOS uncacheable set-by-firmware active bogus > > 0x100000000/0xf020000000 BIOS write-back set-by-firmware active bogus > > 0x120000000/0xf008000000 BIOS write-back set-by-firmware active bogus > > Worried that it says "bogus"? No, not really. This is, as I said earlier, > the result of an issue in the amd64 machdep.c code for handling MTRRs -- > it was written for the original amd64 where the "size" field of the MTRR > was a certain width. On Core 2 Duo these fields are 4 bits shorter, so > the machdep.c code looks at 4 more bits from that register than it should and > so all the size fields have that leading "f" digit. This causes the sizes > to no longer be a power of two, which causes machdep.c to set the "bogus" > flag because those entries look funny. The "bogus" flag being set doesn't > seem to actually break anything, and as near as I can figure if you change > the memcontrol entries the correct data gets written back to the registers > even on Core2Duo, so the "bogus" warnings seem to be pretty harmless. Ahh, I will look at fixing this. -- John Baldwin