From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 21 Jan 2008 16:27:02 +0000 From: Mel Gorman Subject: Re: [PATCH 0/2] Relax restrictions on setting CONFIG_NUMA on x86 Message-ID: <20080121162702.GB8485@csn.ul.ie> References: <20080118153529.12646.5260.sendpatchset@skynet.skynet.ie> <20080121093702.8FC2.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20080121143508.GA8485@csn.ul.ie> <20080121144923.GA8959@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20080121144923.GA8959@elte.hu> Sender: owner-linux-mm@kvack.org Return-Path: To: Ingo Molnar Cc: KOSAKI Motohiro , linux-mm@kvack.org, linux-kernel@vger.kernel.org, apw@shadowen.org List-ID: On (21/01/08 15:49), Ingo Molnar didst pronounce: > > * Mel Gorman wrote: > > > > I think this patch become easy to the porting of fakenuma. > > > > It would be great if that was available, particularly if it could fake > > memoryless nodes as that is a place where we've found a few > > difficult-to-reproduce bugs. > > yeah. Your previous patch (see below) had build problems - are those > resolved meanwhile? > Odd, I couldn't reproduce it Friday and could today. Clearly I was not firing on all cylinders. The problem was because NUMA && FLATMEM are incompatible. Thanks for nudging a second time. However in the patch below addressing the problem below, would it make more sense to replace X86_PC with !NUMA instead of having X86_PC && !NUMA? === Subject: Do not allow FLATMEM && NUMA to be set on x86 at the same time The FLATMEM memory model references a global mem_map and max_mapnr. This is incompatible with how memory models used for NUMA view the world. Builds fail if FLATMEM && NUMA are set on x86. This patch forbids that combination of config items. This is consistent with x86_64 enforcements. Signed-off-by: Mel Gorman --- arch/x86/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.24-rc8-020_init_kmem3lists_nodes/arch/x86/Kconfig linux-2.6.24-rc8-025_memmap_reffix/arch/x86/Kconfig --- linux-2.6.24-rc8-020_init_kmem3lists_nodes/arch/x86/Kconfig 2008-01-19 15:26:00.000000000 +0000 +++ linux-2.6.24-rc8-025_memmap_reffix/arch/x86/Kconfig 2008-01-21 15:51:03.000000000 +0000 @@ -891,7 +891,7 @@ config HAVE_ARCH_ALLOC_REMAP config ARCH_FLATMEM_ENABLE def_bool y - depends on (X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC) || (X86_64 && !NUMA) + depends on (X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC && !NUMA) || (X86_64 && !NUMA) config ARCH_DISCONTIGMEM_ENABLE def_bool y -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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