From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932116Ab1CBXTC (ORCPT ); Wed, 2 Mar 2011 18:19:02 -0500 Received: from rcsinet10.oracle.com ([148.87.113.121]:55856 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757555Ab1CBXS7 (ORCPT ); Wed, 2 Mar 2011 18:18:59 -0500 Message-ID: <4D6ED045.3090309@kernel.org> Date: Wed, 02 Mar 2011 15:18:29 -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" , Tejun Heo , David Rientjes CC: "linux-kernel@vger.kernel.org" Subject: [PATCH for .39] 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: acsmt355.oracle.com [141.146.40.155] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090209.4D6ED04D.0030,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: [ 0.092026] ------------[ cut here ]------------ [ 0.096005] kernel BUG at arch/x86/mm/numa_emulation.c:439! [ 0.096005] invalid opcode: 0000 [#1] SMP [ 0.096005] last sysfs file: [ 0.096005] CPU 0 [ 0.096005] Modules linked in: [ 0.096005] [ 0.096005] Pid: 0, comm: swapper Not tainted 2.6.38-rc6-tip-yh-03869-gcb0491d-dirty #684 Sun Microsystems Sun Fire X4240/Sun Fire X4240 [ 0.096005] RIP: 0010:[] [] numa_add_cpu+0x56/0xcf [ 0.096005] RSP: 0000:ffffffff82437ed8 EFLAGS: 00010246 ... [ 0.096005] Call Trace: [ 0.096005] [] identify_cpu+0x2d7/0x2df [ 0.096005] [] identify_boot_cpu+0x10/0x30 [ 0.096005] [] check_bugs+0x9/0x2d [ 0.096005] [] start_kernel+0x3d7/0x3f1 [ 0.096005] [] x86_64_start_reservations+0x9c/0xa0 [ 0.096005] [] x86_64_start_kernel+0x1dd/0x1e8 [ 0.096005] Code: 74 06 48 8d 04 90 eb 0f 48 c7 c0 30 d9 00 00 48 03 04 d5 90 0f 60 82 8b 00 83 f8 ff 74 0d 0f a3 05 8b 7e 92 00 19 d2 85 d2 75 02 <0f> 0b 48 98 be 00 01 00 00 48 c7 c7 e0 44 60 82 44 8b 2c 85 e0 [ 0.096005] RIP [] numa_add_cpu+0x56/0xcf [ 0.096005] RSP [ 0.096026] ---[ end trace a7919e7f17c0a725 ]--- need to used early_cpu_to_node directly, because numa_cpu_node() will return node0 that is not onlined. Signed-off-by: Yinghai Lu diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c index aeecea9..75b31dc 100644 --- a/arch/x86/mm/numa_emulation.c +++ b/arch/x86/mm/numa_emulation.c @@ -417,9 +417,7 @@ void __cpuinit numa_add_cpu(int cpu) { int physnid, nid; - nid = numa_cpu_node(cpu); - 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)); physnid = emu_nid_to_phys[nid];