Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932228AbVJ0UvU (ORCPT ); Thu, 27 Oct 2005 16:51:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932229AbVJ0UvU (ORCPT ); Thu, 27 Oct 2005 16:51:20 -0400 Received: from coyote.holtmann.net ([217.160.111.169]:9607 "EHLO mail.holtmann.net") by vger.kernel.org with ESMTP id S932228AbVJ0UvU (ORCPT ); Thu, 27 Oct 2005 16:51:20 -0400 Subject: Re: 4GB memory and Intel Dual-Core system From: Marcel Holtmann To: Roland Dreier Cc: linux-kernel@vger.kernel.org In-Reply-To: <52mzkuwuzg.fsf@cisco.com> References: <1130445194.5416.3.camel@blade> <52mzkuwuzg.fsf@cisco.com> Content-Type: text/plain Date: Thu, 27 Oct 2005 22:51:18 +0200 Message-Id: <1130446278.5416.10.camel@blade> Mime-Version: 1.0 X-Mailer: Evolution 2.4.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1814 Lines: 44 Hi Roland, > Marcel> The BIOS and dmidecode tells me that I have 4 GB of RAM > Marcel> installed and I don't have any idea where to look for > Marcel> details. What information do you need to analyze this? > > Look at the e820 dump in your kernel bootlog. I'll bet you'll see a > big chunk of reserved address space. Do you have any PCI devices like > video cards that use a lot of PCI address space? BIOS-provided physical RAM map: BIOS-e820: 0000000000000000 - 000000000009fc00 (usable) BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved) BIOS-e820: 00000000000edbb0 - 0000000000100000 (reserved) BIOS-e820: 0000000000100000 - 00000000cec11000 (usable) BIOS-e820: 00000000cec11000 - 00000000cee12000 (ACPI NVS) BIOS-e820: 00000000cee12000 - 00000000cf68f000 (usable) BIOS-e820: 00000000cf68f000 - 00000000cf6e9000 (ACPI NVS) BIOS-e820: 00000000cf6e9000 - 00000000cf6ed000 (usable) BIOS-e820: 00000000cf6ed000 - 00000000cf6ff000 (ACPI data) BIOS-e820: 00000000cf6ff000 - 00000000cf700000 (usable) I see the stuff above, but the system doesn't contain any PCI device. I didn't install a PCI-Express video card, because I still use the onboard card. > I don't know if EM64T systems (or whatever the right term is) have a > way of remapping some RAM above 4 GB so that you can use all your > memory in a case like this. The kernel is compiled for x86_64 and the term EM64T is correct. The important question is now how do I remap that memory. Loosing almost a full GB of memory wasn't my plan when upgrading to 4 GB. Regards Marcel - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/