From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id 8E7846B005C for ; Fri, 30 Jan 2009 03:57:31 -0500 (EST) Date: Wed, 28 Jan 2009 20:38:13 +0100 From: Pavel Machek Subject: Re: marching through all physical memory in software Message-ID: <20090128193813.GD1222@ucw.cz> References: <497DD8E5.1040305@nortel.com> <20090126075957.69b64a2e@infradead.org> <497F5289.404@nortel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org To: "Eric W. Biederman" Cc: Chris Friesen , Arjan van de Ven , linux-kernel@vger.kernel.org, Doug Thompson , linux-mm@kvack.org, bluesmoke-devel@lists.sourceforge.net List-ID: On Tue 2009-01-27 12:16:52, Eric W. Biederman wrote: > "Chris Friesen" writes: > > > Arjan van de Ven wrote: > >> On Mon, 26 Jan 2009 09:38:13 -0600 > >> "Chris Friesen" wrote: > >> > >>> Someone is asking me about the feasability of "scrubbing" system > >>> memory by accessing each page and handling the ECC faults. > >>> > >> > >> Hi, > >> > >> I would suggest that you look at the "edac" subsystem, which tries to > >> do exactly this.... > > > > edac appears to currently be able to scrub the specific page where the fault > > occurred. This is a useful building block, but doesn't provide the ability to > > march through all of physical memory. > > Well that is the tricky part. The rest is simply finding which physical > addresses are valid. Either by querying the memory controller or looking > at the range the BIOS gave us. > > That part should not be too hard. I think it simply has not been implemented > yet as most ECC chipsets implement this in hardware today. You can do the scrubbing today by echo reboot > /sys/power/disk; echo disk > /sys/power/state :-)... or using uswsusp APIs. Take a look at hibernation code for 'walk all memory' examples... -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/ . Don't email: email@kvack.org