Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760760AbXEUR6q (ORCPT ); Mon, 21 May 2007 13:58:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756908AbXEUR6i (ORCPT ); Mon, 21 May 2007 13:58:38 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:44189 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755701AbXEUR6i (ORCPT ); Mon, 21 May 2007 13:58:38 -0400 From: Darren Hart Organization: IBM Linux Technology Center To: Chris Wright Subject: Re: [stable] [PATCH] Ignore bogus ACPI info for offline CPUs Date: Mon, 21 May 2007 10:58:32 -0700 User-Agent: KMail/1.9.6 Cc: Thomas Gleixner , Andrew Morton , Stable Team , Ingo Molnar , LKML , Len Brown References: <1179584570.12981.123.camel@chaos> <200705210947.35350.dvhltc@us.ibm.com> <20070521170815.GE3429@sequoia.sous-sol.org> In-Reply-To: <20070521170815.GE3429@sequoia.sous-sol.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200705211058.34108.dvhltc@us.ibm.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1552 Lines: 45 On Monday 21 May 2007 10:08:15 Chris Wright wrote: > * Darren Hart (dvhltc@us.ibm.com) wrote: > > On Saturday 19 May 2007 07:22:50 Thomas Gleixner wrote: > > > Booting a SMP kernel with maxcpus=1 on a SMP system leads to a hard > > > hang, because ACPI ignores the maxcpus setting and sends timer > > > broadcast info for the offline CPUs. This results in a stuck for ever > > > call to smp_call_function_single() on an offline CPU. > > > > > > Ignore the bogus information and print a kernel error to remind ACPI > > > folks to fix it. > > > > > > Affects 2.6.21 / 2.6.22-rc > > > > > > Signed-off-by: Thomas Gleixner > > > > When I first booted with this patch I received the following in a loop: > > > > irq 9: nobody cared (try booting with the "irqpoll" option) > > What happens when booting w/out this patch? Don't want to add known > regression to -stable. The system will boot w/o acpi=noirq with and without this patch if maxcpus is not specified. If maxcpus is specified without the patch, the system locks up as Thomas described. If maxcpus is specified with the patch, then acpi=noirq is required to boot - but it will boot. This does not introduce a regression IMO. --Darren > > thanks, > -chris -- Darren Hart IBM Linux Technology Center Realtime Linux Team - 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/