Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751130AbWCLWdU (ORCPT ); Sun, 12 Mar 2006 17:33:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751167AbWCLWdT (ORCPT ); Sun, 12 Mar 2006 17:33:19 -0500 Received: from smtp.osdl.org ([65.172.181.4]:46038 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751130AbWCLWdT (ORCPT ); Sun, 12 Mar 2006 17:33:19 -0500 Date: Sun, 12 Mar 2006 14:30:53 -0800 From: Andrew Morton To: Krzysztof Oledzki Cc: 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: <20060312143053.530ef6c9.akpm@osdl.org> In-Reply-To: References: <20060311210353.7eccb6ed.akpm@osdl.org> <20060312032523.109361c1.akpm@osdl.org> <20060312073524.A9213@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: 1173 Lines: 26 Krzysztof Oledzki wrote: > > > 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. > > Why? I have exactly 4 HT CPUs (2 cores), no more. I use CPU hotplug so I > can disable or enable any of them when I want to. So, this is a classic > SMP system and 2.6.15 is totally happy with this. Or is there any other > (better?) way to disable/enable CPU (especially second logical CPU from > HT) on running systems? Maybe we should have: if (num_possible_cpus() <= 8) dont_do_any_of_that_stuff(); That's assuming that hotplug-cpu-capable platforms are correctly setting cpu_possible_map. Do they? - 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/