Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754587Ab3JCPK5 (ORCPT ); Thu, 3 Oct 2013 11:10:57 -0400 Received: from g6t0184.atlanta.hp.com ([15.193.32.61]:12602 "EHLO g6t0184.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753921Ab3JCPKz (ORCPT ); Thu, 3 Oct 2013 11:10:55 -0400 Message-ID: <1380812843.5429.46.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: Thu, 03 Oct 2013 09:07:23 -0600 In-Reply-To: <524D7D81.9090903@asianux.com> References: <524B8E97.1030707@asianux.com> <1380727725.5429.13.camel@misato.fc.hp.com> <524C4CC9.3080402@gmail.com> <1380742391.5429.37.camel@misato.fc.hp.com> <524CBF19.2030708@asianux.com> <524D7D81.9090903@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: 2066 Lines: 51 On Thu, 2013-10-03 at 22:21 +0800, Chen Gang wrote: > One root cause found (but not only one), allmodconfig will enable > CONFIG_SYSFS_DEPRECATED which for new kernel on old distribution. > > > I am comparing from allmodconfig config file to defconfig config file, > the attachments are middle files (one enable CONFIG_SYSFS_DEPRECATED > which can not boot up, the other disable it which can boot up). > > The related information in "init/Kconfig" > > config SYSFS_DEPRECATED > bool "Enable deprecated sysfs features to support old userspace tools" > depends on SYSFS > default n > help > This option adds code that switches the layout of the "block" class > devices, to not show up in /sys/class/block/, but only in > /sys/block/. > > This switch is only active when the sysfs.deprecated=1 boot option is > passed or the SYSFS_DEPRECATED_V2 option is set. > > This option allows new kernels to run on old distributions and tools, > which might get confused by /sys/class/block/. Since 2007/2008 all > major distributions and tools handle this just fine. > > Recent distributions and userspace tools after 2009/2010 depend on > the existence of /sys/class/block/, and will not work with this > option enabled. > > Only if you are using a new kernel on an old distribution, you might > need to say Y here. > > > I will continue to analyze another related issues for allmodconfig on > my laptop (after disable SYSFS_DEPRECATED, for allmodconfig, it still > can not boot up successfully, although my 'middle' config file can). Since this is no longer a hotplug issue, I'd suggest you change the subject line and resend it to the folks who worked on this config option. I won't be able to help on this one. -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/