From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759404Ab1CDLEI (ORCPT ); Fri, 4 Mar 2011 06:04:08 -0500 Received: from mail-fx0-f46.google.com ([209.85.161.46]:59676 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752084Ab1CDLEG (ORCPT ); Fri, 4 Mar 2011 06:04:06 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=umRhdM2f/nEAZ4AaGXIlo/kocMJQXuYuAO8zIKASKmuky+gKaVp6yoFpDnP/0NFood GSwmjqqS8Dw5cVfIAS2sfITW7MaugyHLP/tyeZQH9vBDo+eGZ+h+vjraKHRBTOZ5LzFo YEvLOSs4mdoliwu9oxUOBlKE4gyzvk0lf6JYw= Date: Fri, 4 Mar 2011 12:04:01 +0100 From: Tejun Heo To: Yinghai Lu Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , David Rientjes , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH for .39] x86, numa: Fix numa_emulation code with node0 without RAM Message-ID: <20110304110401.GI20499@htj.dyndns.org> References: <4D6ED045.3090309@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4D6ED045.3090309@kernel.org> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 02, 2011 at 03:18:29PM -0800, Yinghai Lu wrote: > > 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 Acked-by: Tejun Heo Thanks. -- tejun