From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750958AbWAZHf3 (ORCPT ); Thu, 26 Jan 2006 02:35:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751009AbWAZHf3 (ORCPT ); Thu, 26 Jan 2006 02:35:29 -0500 Received: from moutng.kundenserver.de ([212.227.126.171]:30409 "EHLO moutng.kundenserver.de") by vger.kernel.org with ESMTP id S1750914AbWAZHf2 (ORCPT ); Thu, 26 Jan 2006 02:35:28 -0500 From: Prakash Punnoor To: Robert Hancock Subject: Re: AMD64, 4GB, mttr questions Date: Thu, 26 Jan 2006 08:37:41 +0100 User-Agent: KMail/1.9 Cc: linux-kernel , thockin@hockin.org References: <5ywpz-49F-11@gated-at.bofh.it> <43D6C2BD.50301@shaw.ca> In-Reply-To: <43D6C2BD.50301@shaw.ca> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart6859410.KS7ahp6ngd"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200601260837.44595.prakash@punnoor.de> X-Provags-ID: kundenserver.de abuse@kundenserver.de login:cec1af1025af73746bdd9be3587eb485 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --nextPart6859410.KS7ahp6ngd Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Am Mittwoch Januar 25 2006 01:13 schrieb Robert Hancock: > Prakash Punnoor wrote: > > I have a machine with 4GB RAM, an Athlon64 X2 and following mttr entrie= s: > > > > reg00: base=3D0x00000000 ( 0MB), size=3D4096MB: write-back, count=3D1 > > reg01: base=3D0x100000000 (4096MB), size=3D2048MB: write-back, count=3D1 > > reg02: base=3D0x80000000 (2048MB), size=3D2048MB: uncachable, count=3D1 > > > > First of all, why is there an uncachable region? Is it the upper half of > > memory? Or is this just a hole and the remaining 2GB are seated at > > 0x100000000 ? > > Your e820 memory map shows the first 2GB of RAM is at 0-2GB and the > remaining 2GB is at 4-6GB, so yes there is a hole. This doesn't explain > why all of 0-4GB is set as write-back and then the top half of it is > also set as uncacheable. This will presumably have been set up by the > BIOS though, I don't think the kernel does this. OK thanks to both of you for clearing this up. :-) Cheers, =2D-=20 (=B0=3D =3D=B0) //\ Prakash Punnoor /\\ V_/ \_V --nextPart6859410.KS7ahp6ngd Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) iD8DBQBD2HxIxU2n/+9+t5gRAlWOAKCfHz5CkM9BTL5h2nvJu53ADLebLACgqJR6 WXilprX+zc0dOBqU5l74mEo= =mAM2 -----END PGP SIGNATURE----- --nextPart6859410.KS7ahp6ngd--