From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id 385158D003B for ; Wed, 20 Apr 2011 12:01:32 -0400 (EDT) Date: Wed, 20 Apr 2011 18:01:26 +0200 From: Borislav Petkov Subject: Re: Background memory scrubbing Message-ID: <20110420160125.GC2312@gere.osrc.amd.com> References: <18563.1303314382@jupiter.eclipse.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <18563.1303314382@jupiter.eclipse.co.uk> Sender: owner-linux-mm@kvack.org List-ID: To: Robert Whitton Cc: Clemens Ladisch , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Wed, Apr 20, 2011 at 04:46:22PM +0100, Robert Whitton wrote: > > > On Wed, Apr 20, 2011 at 05:19:41PM +0200, Clemens Ladisch wrote: > > > > Unfortunately in common with a large number of hardware platforms > > > > background scrubbing isn't supported in the hardware (even though ECC > > > > error correction is supported) and thus there is no BIOS option to > > > > enable it. > > > > > > Which hardware platform is this? AFAICT all architectures with ECC > > > (old AMD64, Family 0Fh, Family 10h) also have scrubbing support. > > > If your BIOS is too dumb, just try enabling it directly (bits 0-4 of > > > PCI configuration register 0x58 in function 3 of the CPU's northbridge > > > device, see the BIOS and Kernel's Developer's Guide for details). > > > > Or even better, if on AMD, you can build the amd64_edac module > > (CONFIG_EDAC_AMD64) and do > > > > echo > /sys/devices/system/edac/mc/mc/sdram_scrub_rate > > > > where x is the scrubbing bandwidth in bytes/sec and y is the memory > > controller on the machine, i.e. node. > > Unfortunately that also isn't an option on my platform(s). There surely must be a way for a module to be able to get a mapping for each physical page of memory in the system and to be able to use that mapping to do atomic read/writes to scrub the memory. For such questions I've added just the right ML to Cc :). -- Regards/Gruss, Boris. Advanced Micro Devices GmbH Einsteinring 24, 85609 Dornach General Managers: Alberto Bozzo, Andrew Bowd Registration: Dornach, Gemeinde Aschheim, Landkreis Muenchen Registergericht Muenchen, HRB Nr. 43632 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org