From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e4.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id m0NLacJe000740 for ; Wed, 23 Jan 2008 16:36:38 -0500 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m0NLacl7171652 for ; Wed, 23 Jan 2008 16:36:38 -0500 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m0NLabEN029093 for ; Wed, 23 Jan 2008 16:36:38 -0500 Date: Wed, 23 Jan 2008 13:36:37 -0800 From: Nishanth Aravamudan 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: Sender: owner-linux-mm@kvack.org Return-Path: 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 List-ID: 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, 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