Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751055AbWCLPfs (ORCPT ); Sun, 12 Mar 2006 10:35:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751059AbWCLPfs (ORCPT ); Sun, 12 Mar 2006 10:35:48 -0500 Received: from fmr22.intel.com ([143.183.121.14]:14797 "EHLO scsfmr002.sc.intel.com") by vger.kernel.org with ESMTP id S1751006AbWCLPfs (ORCPT ); Sun, 12 Mar 2006 10:35:48 -0500 Date: Sun, 12 Mar 2006 07:35:25 -0800 From: Venkatesh Pallipadi To: Krzysztof Oledzki Cc: Andrew Morton , linux-kernel@vger.kernel.org, Ashok Raj , Venkatesh Pallipadi , Suresh B Siddha , Rajesh Shah Subject: Re: More than 8 CPUs detected and CONFIG_X86_PC cannot handle it on 2.6.16-rc6 Message-ID: <20060312073524.A9213@unix-os.sc.intel.com> References: <20060311210353.7eccb6ed.akpm@osdl.org> <20060312032523.109361c1.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: ; from olel@ans.pl on Sun, Mar 12, 2006 at 02:05:00PM +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1830 Lines: 53 On Sun, Mar 12, 2006 at 02:05:00PM +0100, Krzysztof Oledzki wrote: > > > On Sun, 12 Mar 2006, Andrew Morton wrote: > > > Krzysztof Oledzki wrote: > >> > >> On Sat, 11 Mar 2006, Andrew Morton wrote: > >> > >> > Krzysztof Oledzki wrote: > >> >> > >> >> After upgrading to 2.6.16-rc6 I noticed this strange message: > >> >> > >> >> More than 8 CPUs detected and CONFIG_X86_PC cannot handle it. > >> >> Use CONFIG_X86_GENERICARCH or CONFIG_X86_BIGSMP. > >> >> > >> >> This is a Dell PowerEdge SC1425 with two P4 Xeons with HT enabled (so with > >> >> totoal of 4 logical CPUs). > >> > > >> > Please send full dmesg output for the failing kernel, thanks. > >> Attached. > >> > >> > Which is the most-recently-tested kernel which behaved correctly? > >> 2.6.15.6 > > > > OK, thanks. I assume the machine's working OK? > > Yes. So far no problems, only this warning. > > > From my reading, you have CONFIG_HOTPLUG_CPU enabled and the machine has an > > APIC. > That is correct. > > > I'd expect that lots of people would hit that warning but for some > > reason they don't - possibly because most APICs don't have sufficiently > > high version numbers? > > Actually, this warning should be seen on many other systems on well. We use the bigsmp when there _or_ more than 8 CPUs or CPU_HOTPLUG is used. So, in that sense the message is wrong, it should also have CPU_HOTPLUG in there. Or we should make CPU_HOTPLUG depend on GENERIC_ARCH or auto select GENERIC_ARCH with hotplug at the CONFIG level. Will defer to Ashok for a proper fix. Thanks, Venki - 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/