From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757799AbYDPASn (ORCPT ); Tue, 15 Apr 2008 20:18:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753404AbYDPASg (ORCPT ); Tue, 15 Apr 2008 20:18:36 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:44257 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751434AbYDPASg (ORCPT ); Tue, 15 Apr 2008 20:18:36 -0400 Date: Wed, 16 Apr 2008 02:18:16 +0200 From: Ingo Molnar To: Linus Torvalds Cc: Pekka Enberg , Christoph Lameter , linux-kernel@vger.kernel.org, Mel Gorman , Nick Piggin , Andrew Morton , "Rafael J. Wysocki" , Yinghai.Lu@sun.com, apw@shadowen.org, KAMEZAWA Hiroyuki Subject: Re: [patch] mm: sparsemem memory_present() memory corruption fix Message-ID: <20080416001816.GA26295@elte.hu> References: <20080415161532.GA15088@elte.hu> <20080415195430.GA23015@elte.hu> <20080415201734.GA25628@elte.hu> <4805115D.5030703@cs.helsinki.fi> <20080415204025.GA29784@elte.hu> <20080416000356.GA24737@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080416000356.GA24737@elte.hu> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Ingo Molnar wrote: > finally found it ... the patch below solves the sparsemem crash and > the testsystem boots up fine now: > > mars:~> uname -a > Linux mars 2.6.25-rc9-sched-devel.git-x86-latest.git #985 SMP Wed Apr 16 > 01:37:37 CEST 2008 i686 i686 i386 GNU/Linux i re-checked the original SLAB config too and that boots fine as well now - so i'm confident that the regression has been sufficiently cured. it's getting quite late here (or rather, it's getting early :-/ ) so it would be nice if others could double-check this calculation (with an eye on all possible architectures): + unsigned long max_arch_pfn = 1ULL << (MAX_PHYSMEM_BITS-PAGE_SHIFT); and also check my analysis whether it is correct and whether it matches the reported bug patterns. But otherwise the fix looks like a safe fix for v2.6.25-final to me - it only filters out values from sparsemem input that are nonsensical in the sparsemem framework anyway. Ingo