Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932397AbWCMTyj (ORCPT ); Mon, 13 Mar 2006 14:54:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932403AbWCMTyj (ORCPT ); Mon, 13 Mar 2006 14:54:39 -0500 Received: from smtp.osdl.org ([65.172.181.4]:59347 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S932397AbWCMTyi (ORCPT ); Mon, 13 Mar 2006 14:54:38 -0500 Date: Mon, 13 Mar 2006 11:51:55 -0800 From: Andrew Morton To: Ashok Raj Cc: olel@ans.pl, venkatesh.pallipadi@intel.com, linux-kernel@vger.kernel.org, ashok.raj@intel.com, suresh.b.siddha@intel.com, rajesh.shah@intel.com Subject: Re: More than 8 CPUs detected and CONFIG_X86_PC cannot handle it on 2.6.16-rc6 Message-Id: <20060313115155.24dfb6f3.akpm@osdl.org> In-Reply-To: <20060313113615.A24797@unix-os.sc.intel.com> References: <20060311210353.7eccb6ed.akpm@osdl.org> <20060312032523.109361c1.akpm@osdl.org> <20060312073524.A9213@unix-os.sc.intel.com> <20060312143053.530ef6c9.akpm@osdl.org> <20060313113615.A24797@unix-os.sc.intel.com> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1423 Lines: 32 Ashok Raj wrote: > > When CONFIG_HOTPLUG_CPU is turned on we always use physflat mode (bigsmp) even > when #of CPUs are less than 8 to avoid sending IPI to offline processors. > > Without having BIGSMP on it spits out a warning during boot on systems that > seems misleading, since it complains even on systems that have less > than 8 cpus. > > ... > > --- linux-2.6.16-rc6-mm1.orig/arch/i386/Kconfig > +++ linux-2.6.16-rc6-mm1/arch/i386/Kconfig > @@ -760,7 +760,7 @@ config PHYSICAL_START > > config HOTPLUG_CPU > bool "Support for hot-pluggable CPUs (EXPERIMENTAL)" > - depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER > + depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER && (X86_GENERICARCH || X86_BIGSMP) > ---help--- > Say Y here to experiment with turning CPUs off and on. CPUs > can be controlled through /sys/devices/system/cpu. One of the main reasons for turning on CONFIG_HOTPLUG_CPU on x86 is actually for suspend-to-disk on SMP. I don't think it's desirable to force all those little machines to use X86_GENERICARCH || X86_BIGSMP. And it'd be good to make that warning go away for 2.6.16. - 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/