Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752863AbYAWVgv (ORCPT ); Wed, 23 Jan 2008 16:36:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751261AbYAWVgn (ORCPT ); Wed, 23 Jan 2008 16:36:43 -0500 Received: from e2.ny.us.ibm.com ([32.97.182.142]:56827 "EHLO e2.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751103AbYAWVgm (ORCPT ); Wed, 23 Jan 2008 16:36:42 -0500 Date: Wed, 23 Jan 2008 13:36:37 -0800 From: Nishanth Aravamudan To: Christoph Lameter Cc: Pekka Enberg , Mel Gorman , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, "Aneesh Kumar K.V" , KAMEZAWA Hiroyuki , lee.schermerhorn@hp.com, Linux MM , Olaf Hering Subject: Re: [PATCH] Fix boot problem in situations where the boot CPU is running on a memoryless node Message-ID: <20080123213637.GE3848@us.ibm.com> References: <20080123125236.GA18876@aepfle.de> <20080123135513.GA14175@csn.ul.ie> <20080123155655.GB20156@csn.ul.ie> <20080123195220.GB3848@us.ibm.com> <84144f020801231302g2cafdda9kf7f916121dc56aa5@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Operating-System: Linux 2.6.24-4-generic (i686) User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1325 Lines: 30 On 23.01.2008 [13:14:26 -0800], Christoph Lameter wrote: > On Wed, 23 Jan 2008, Pekka Enberg wrote: > > > I think Mel said that their configuration did work with 2.6.23 > > although I also wonder how that's possible. AFAIK there has been some > > changes in the page allocator that might explain this. That is, if > > kmem_getpages() returned pages for memoryless node before, bootstrap > > would have worked. > > Regular kmem_getpages is called with GFP_THISNODE set. There was some > breakage in 2.6.22 and before with GFP_THISNODE returning pages from > the wrong node if a node had no memory. So it may have worked > accidentally and in an unsafe manner because the pages would have been > associated with the wrong node which could trigger bug ons and locking > troubles. Right, so it might have functioned before, but the correctness was wobbly at best... Certainly the memoryless patch series has tightened that up, but we missed these SLAB issues. I see that your patch fixed Olaf's machine, Pekka. Nice work on everyone's part tracking this stuff down. Thanks, Nish -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/