Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754581Ab1EDPCo (ORCPT ); Wed, 4 May 2011 11:02:44 -0400 Received: from cantor2.suse.de ([195.135.220.15]:53340 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754040Ab1EDPCm (ORCPT ); Wed, 4 May 2011 11:02:42 -0400 Subject: Re: [git pull] m68k SLUB fix for 2.6.39 From: James Bottomley To: David Rientjes Cc: Geert Uytterhoeven , Linus Torvalds , Andrew Morton , Pekka Enberg , Christoph Lameter , linux-m68k@vger.kernel.org, linux-kernel@vger.kernel.org In-Reply-To: References: <1304026464.2598.36.camel@mulgrave.site> Content-Type: text/plain; charset="UTF-8" Date: Wed, 04 May 2011 10:02:35 -0500 Message-ID: <1304521355.2810.21.camel@mulgrave.site> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2125 Lines: 47 On Thu, 2011-04-28 at 14:41 -0700, David Rientjes wrote: > On Thu, 28 Apr 2011, James Bottomley wrote: > > > > Since 4a5fa3590f09 ([PARISC] slub: fix panic with DISCONTIGMEM) from > > > 2.6.39-rc4, you can't actually select slub on m68k without CONFIG_ADVANCED > > > and CONFIG_SINGLE_MEMORY_CHUNK because it otherwises defaults to > > > discontigmem. > > > > > > James tested hppa64 with my N_NORMAL_MEMORY fix and found that it turned > > > an SMP box into UP. If you've tested slub on m68k without regressions, > > > then perhaps you'd like to add a "|| M68K" to CONFIG_SLUB? > > > > To be honest, I really don't see that fixing it. As soon as you > > allocate memory beyond range zero, you move onto a non-zero node as far > > as slub is concerned, and that will oops. > > > > Possible nodes are represented in slub with N_NORMAL_MEMORY, so the > kmem_cache_node structures are allocated and initialized based on this > nodemask. As long as the memory ranges map to nodes set in the nodemask, > this should be fine. > > > I think what the N_NORMAL_MEMORY patch did is just make it take a whiile > > before you start allocating from that range. Try executing a memory > > balloon on the platform; that was how we first demonstrated the problem > > on parisc. > > > > With parisc, you encountered an oops in add_partial() because the > kmem_cache_node structure for the memory range returned by page_to_nid() > was not allocated. init_kmem_cache_nodes() takes care of this for all > memory ranges set in N_NORMAL_MEMORY. Yes, but I also encountered it after I applied you patch, which is why I still pushed the Kconfig patch. It's possible, since there were a huge number of patches flying around that the kernel base was contaminated, so I'll strip down to just linus HEAD + parisc coherence patches, reverting the Kconfig one and try again. James -- 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/