From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sat, 19 Jan 2008 16:24:00 +0100 From: Ingo Molnar Subject: Re: [PATCH 4/5] x86: Add config variables for SMP_MAX Message-ID: <20080119152357.GA11706@elte.hu> References: <20080118183011.354965000@sgi.com> <20080118183011.917801000@sgi.com> <20080119145243.GA27974@elte.hu> <20080119151522.GA7774@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080119151522.GA7774@elte.hu> Sender: owner-linux-mm@kvack.org Return-Path: To: travis@sgi.com Cc: Andrew Morton , Andi Kleen , Christoph Lameter , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: * Ingo Molnar wrote: > and then it crashes with: > > [ 0.000000] Bootmem setup node 0 0000000000000000-000000003fff0000 > [ 0.000000] KERN_NOTICE cpu_to_node(0): usage too early! > PANIC: early exception 06 rip 10:ffffffff81f77f30 error 0 cr2 f06f53 > [ 0.000000] Pid: 0, comm: swapper Not tainted 2.6.24-rc8 #422 > [ 0.000000] > [ 0.000000] Call Trace: > [ 0.000000] [] ? setup_node_bootmem+0x1a0/0x1b8 > [ 0.000000] [] ? acpi_scan_nodes+0x204/0x255 > [ 0.000000] [] ? acpi_scan_nodes+0x204/0x255 > [ 0.000000] [] ? numa_initmem_init+0x343/0x471 > > moral: PLEASE do not use BUG() on in early init code, unless > absolutely necessary. the right fix is below. Ingo --- include/asm-x86/topology.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) Index: linux/include/asm-x86/topology.h =================================================================== --- linux.orig/include/asm-x86/topology.h +++ linux/include/asm-x86/topology.h @@ -70,10 +70,10 @@ static inline int cpu_to_node(int cpu) if(x86_cpu_to_node_map_early_ptr) { printk("KERN_NOTICE cpu_to_node(%d): usage too early!\n", (int)cpu); - BUG(); + dump_stack(); } #endif - if(per_cpu_offset(cpu)) + if (per_cpu_offset(cpu)) return per_cpu(x86_cpu_to_node_map, cpu); else return NUMA_NO_NODE; -- 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