Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754590Ab3JBQm4 (ORCPT ); Wed, 2 Oct 2013 12:42:56 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:58754 "EHLO mail-pb0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753434Ab3JBQmy (ORCPT ); Wed, 2 Oct 2013 12:42:54 -0400 Message-ID: <524C4CC9.3080402@gmail.com> Date: Thu, 03 Oct 2013 00:41:45 +0800 From: Chen Gang F T User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Toshi Kani CC: Chen Gang , 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" Subject: Re: [Suggestion] about calling debug_hotplug_cpu() which enabled by 'allmodconfig' for a x86_64 dual core laptop. References: <524B8E97.1030707@asianux.com> <1380727725.5429.13.camel@misato.fc.hp.com> In-Reply-To: <1380727725.5429.13.camel@misato.fc.hp.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2061 Lines: 56 On 10/02/2013 11:28 PM, Toshi Kani wrote: > 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'. > Hmm... excuse me, I don't know: for laptop, if cpu0 is offline, whether it still can work or not. If any members know about it, please tell me, thanks. In my opinion, if enable DEBUG_HOTPLUG_CPU0, but "should not let cpu0 offline for laptop", we need let 'offline' operation fail. And I am analyzing (just constructing environments: KVM, kgdb ...), before let kernel start successfully, only according to my current proofs, we can not say "let laptop cpu0 offline" must be an issue. Thanks. > 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/ > Thanks. -- Chen Gang -- 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/