Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753480Ab3JBPcT (ORCPT ); Wed, 2 Oct 2013 11:32:19 -0400 Received: from g1t0029.austin.hp.com ([15.216.28.36]:8060 "EHLO g1t0029.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752926Ab3JBPcQ (ORCPT ); Wed, 2 Oct 2013 11:32:16 -0400 Message-ID: <1380727725.5429.13.camel@misato.fc.hp.com> Subject: Re: [Suggestion] about calling debug_hotplug_cpu() which enabled by 'allmodconfig' for a x86_64 dual core laptop. From: Toshi Kani To: Chen Gang Cc: Thomas Gleixner , "mingo@redhat.com" , "H. Peter Anvin" , the arch/x86 maintainers , "Yu, Fenghua" , "rafael.j.wysocki@intel.com" , "isimatu.yasuaki@jp.fujitsu.com" , "linux-kernel@vger.kernel.org" Date: Wed, 02 Oct 2013 09:28:45 -0600 In-Reply-To: <524B8E97.1030707@asianux.com> References: <524B8E97.1030707@asianux.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.8.5 (3.8.5-2.fc19) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1210 Lines: 31 On Wed, 2013-10-02 at 03:10 +0000, Chen Gang wrote: > Hello Maintainers: > > Under my x86_64 dual core laptop, I build kernel next-20130927 with > 'allmodconfig', and install it, the machine can not start. Related > information is: > > after call debug_hotplug_cpu(), output "cpu 0 is offline" .... and then "Failed to execute /init". > > After remove "_debug_hotplug_cpu(0, 0);", can pass the issue (but will > fail in another place). I guess, the reason is my laptop cpu is not > 'hotplug', but have to call debug_hotplug_cpu() with allmodconfig. > > > I will continue analyzing, welcome any additional suggestions or > completions. allmodconfig sets CONFIG_DEBUG_HOTPLUG_CPU0 to y (which is defined as "def_bool n"), which puts CPU0 offline during boot for testing. This debug feature is causing the problem on your laptop. I am not familiar with allmodconfig, but it seems that it enables all the config options, preferably with 'm'. Thanks, -Toshi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/