Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946097AbWJSOtD (ORCPT ); Thu, 19 Oct 2006 10:49:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1946098AbWJSOtB (ORCPT ); Thu, 19 Oct 2006 10:49:01 -0400 Received: from smtp107.mail.mud.yahoo.com ([209.191.85.217]:5980 "HELO smtp107.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S1946097AbWJSOtA (ORCPT ); Thu, 19 Oct 2006 10:49:00 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=YqZr0UJLMCIpuqPRfANA0aWr0p5uJYMU2zo/X9ngyHvwCzmnh32/PrMoaxnNQ9pZ9HGgHmUh1tOL7N+6Udvyi4a99TYxNh21M+zn+7Fay1bn9PHU3AxSSzVCbBFhkKI+PcRv5aNnV58RGxbhssxini0Ro3EweSq/YatWMeGRbFs= ; Message-ID: <45379031.601@yahoo.com.au> Date: Fri, 20 Oct 2006 00:48:17 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Andi Kleen CC: Daniel Walker , linux-kernel@vger.kernel.org, johnstul@us.ibm.com, mingo@elte.hu, tglx@linutronix.de Subject: Re: + i386-time-avoid-pit-smp-lockups.patch added to -mm tree References: <200610112126.k9BLQqKG002529@shell0.pdx.osdl.net> <1161266225.11264.13.camel@c-67-180-230-165.hsd1.ca.comcast.net> <45378A35.5020101@yahoo.com.au> <200610191626.10662.ak@suse.de> In-Reply-To: <200610191626.10662.ak@suse.de> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 815 Lines: 21 Andi Kleen wrote: >>An SMP kernel can boot on UP hardware, in which case I think >>num_possible_cpus() will be 1, won't it? > > > 0 was a typo, i meant 1 for UP of course. 0 would be nonsensical. Sure, I realised that. For a UP kernel, the test will compile away. But Daniel seems to say there is dead code that could be compiled out for SMP kernels. I just don't think that is possible because the SMP kernel can boot a UP system where num_possible_cpus() is 1. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com - 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/