From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id 7D6BC6B0083 for ; Fri, 30 Jan 2009 15:20:54 -0500 (EST) Message-ID: <49836114.1090209@buttersideup.com> Date: Fri, 30 Jan 2009 20:20:36 +0000 From: Tim Small MIME-Version: 1.0 Subject: Re: marching through all physical memory in software References: <715599.77204.qm@web50111.mail.re2.yahoo.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: "Eric W. Biederman" Cc: Doug Thompson , ncunningham-lkml@crca.org.au, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Chris Friesen , Pavel Machek , bluesmoke-devel@lists.sourceforge.net, Arjan van de Ven List-ID: Eric W. Biederman wrote: > A background software scrubber simply has the job of rewritting memory > to it's current content so that the data and the ecc check bits are > guaranteed to be in sync Don't you just need to READ memory? The memory controller hardware takes care of the rest in the vast majority of cases. You only need to rewrite RAM if a correctable error occurs, and the chipset doesn't support automatic write-back of the corrected value (a different problem altogether...). The actual memory bits themselves are refreshed by the hardware quite frequently (max of every 64ms for DDR2, I believe)... Cheers, Tim. -- 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