From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 17 Aug 2001 10:15:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 17 Aug 2001 10:15:10 -0400 Received: from nef.ens.fr ([129.199.96.32]:18700 "EHLO nef.ens.fr") by vger.kernel.org with ESMTP id ; Fri, 17 Aug 2001 10:14:59 -0400 Date: Fri, 17 Aug 2001 16:15:05 +0200 From: David Madore To: linux-kernel@vger.kernel.org Subject: broken memory chip -> software fix? Message-ID: <20010817161505.A25194@clipper.ens.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi all. I have a broken bit in my memory - at address 0x04d5ae38 if you want to know the details (bit 29 of the double word there sometimes reads as 1 when it was written as 0, in particular if bit 15 is at 1). I discovered this by observing a one-bit corruption of some files, and diagnosed it by running memtest86. Now that I know the address, is there a way I can prevent Linux from using that region of memory in any way? The simplest and cleanest way, would be, I guess, for a userland process I would write to ask of the kernel to map permanently and unswappably the page at physical location 0x04d5a000 to its virtual address space. (Besides, that would let me play with that broken bit.) So: is there a way for a userland process (running at euid 0) to request of the kernel an explicit physical address to virtual address translation? If so, how? I would prefer not to have to patch the kernel, if at all possible. Thanks, -- David A. Madore (david.madore@ens.fr, http://www.eleves.ens.fr:8080/home/madore/ )