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 ESMTP id 6AC5C6B00EA for ; Wed, 29 Jun 2011 17:24:44 -0400 (EDT) Received: by vxg38 with SMTP id 38so1745779vxg.14 for ; Wed, 29 Jun 2011 14:24:41 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <532cc290-4b9c-4eb2-91d4-aa66c01bb3a0@glegroupsg2000goo.googlegroups.com> <20110629080827.GA975@phantom.vanrein.org> Date: Wed, 29 Jun 2011 14:24:41 -0700 Message-ID: Subject: Re: [PATCH v2 0/3] support for broken memory modules (BadRAM) From: Tony Luck Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: Craig Bergstrom Cc: linux-kernel@vger.kernel.org, fa.linux.kernel@googlegroups.com, Rick van Rein , "H. Peter Anvin" , Stefan Assmann , "linux-mm@kvack.org" , "akpm@linux-foundation.org" , Andi Kleen , "mingo@elte.hu" , "rdunlap@xenotime.net" , Nancy Yuen , Michael Ditto One extra consideration for this whole proposal ... Is the "physical address" a stable enough representation of the location of the faulty memory cells? On high end systems I can see a number of ways where the mapping from cells to physical address may change across reboot: 1) System support redundant memory (rank sparing or mirroring) 2) BIOS self test removes some memory from use 3) A multi-node system elects a different node to be boot-meister, which results in reshuffling of the address map. If any of these can happen: then it doesn't matter whether we have a list of addresses, or a pattern that expands to a list of addresses. We'll still mark some innocent memory as bad, and allow some known bad memory to be used - because our "addresses" no longer correspond to the bad memory cells. -Tony -- 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