From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758053Ab1CBXQJ (ORCPT ); Wed, 2 Mar 2011 18:16:09 -0500 Received: from rcsinet10.oracle.com ([148.87.113.121]:53437 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755904Ab1CBXQH (ORCPT ); Wed, 2 Mar 2011 18:16:07 -0500 Message-ID: <4D6ECF72.5010308@kernel.org> Date: Wed, 02 Mar 2011 15:14:58 -0800 From: Yinghai Lu User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.16) Gecko/20101125 SUSE/3.0.11 Thunderbird/3.0.11 MIME-Version: 1.0 To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , David Rientjes , Andrew Morton CC: "linux-kernel@vger.kernel.org" Subject: [PATCH for.38] x86, numa: Fix numa_emulation code with node0 without RAM Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: acsmt353.oracle.com [141.146.40.153] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090204.4D6ECF85.00DC,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On one system that does not have RAM on node0. when numa_emulation is compiled in, and 1. boot system without numa=fake... 2. or boot system with numa=fake=128 to make emulation fail will get: [ 0.076025] ------------[ cut here ]------------ [ 0.080004] kernel BUG at arch/x86/mm/numa_64.c:788! [ 0.080004] invalid opcode: 0000 [#1] SMP [ 0.080004] last sysfs file: [ 0.080004] CPU 0 [ 0.080004] Modules linked in: [ 0.080004] [ 0.080004] Pid: 0, comm: swapper Not tainted 2.6.38-rc6-yh-00212-g3e1f235 #1 Sun Microsystems Sun Fire X4240/Sun Fire X4240 [ 0.080004] RIP: 0010:[] [] numa_add_cpu+0x8a/0x156 ... [ 0.080004] Call Trace: [ 0.080004] [] identify_cpu+0x2d7/0x2df [ 0.080004] [] identify_boot_cpu+0x10/0x30 [ 0.080004] [] check_bugs+0x9/0x2d [ 0.080004] [] start_kernel+0x3bf/0x3d9 [ 0.080004] [] x86_64_start_reservations+0xb6/0xba [ 0.080004] [] x86_64_start_kernel+0xf7/0xfe [ 0.080004] Code: 74 06 48 8d 04 90 eb 0f 48 c7 c0 10 d9 00 00 48 03 04 d5 50 e1 5f 82 8b 00 83 f8 ff 74 0d 0f a3 05 7a f9 92 00 19 d2 85 d2 75 02 <0f> 0b 48 98 31 db 48 8b 04 c5 d0 ec 5f 82 48 8b 90 90 af 00 00 need to used early_cpu_to_node directly, because cpu_to_apicid and apicid_to_node will return node0 that is not onlined. Signed-off-by: Yinghai Lu --- arch/x86/mm/numa_64.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) Index: linux-2.6/arch/x86/mm/numa_64.c =================================================================== --- linux-2.6.orig/arch/x86/mm/numa_64.c +++ linux-2.6/arch/x86/mm/numa_64.c @@ -780,11 +780,7 @@ void __cpuinit numa_add_cpu(int cpu) int physnid; int nid = NUMA_NO_NODE; - apicid = early_per_cpu(x86_cpu_to_apicid, cpu); - if (apicid != BAD_APICID) - nid = apicid_to_node[apicid]; - if (nid == NUMA_NO_NODE) - nid = early_cpu_to_node(cpu); + nid = early_cpu_to_node(cpu); BUG_ON(nid == NUMA_NO_NODE || !node_online(nid)); /*