From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756632AbYHaRbj (ORCPT ); Sun, 31 Aug 2008 13:31:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754633AbYHaRbb (ORCPT ); Sun, 31 Aug 2008 13:31:31 -0400 Received: from e32.co.us.ibm.com ([32.97.110.150]:48378 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754298AbYHaRba (ORCPT ); Sun, 31 Aug 2008 13:31:30 -0400 Date: Sun, 31 Aug 2008 10:31:27 -0700 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: paulus@samba.org, benh@kernel.crashing.org, jwboyer@linux.vnet.ibm.com, tnt@246tNt.com, grant.likely@secretlab.ca, linuxppc-dev@ozlabs.org, manfred@colorfullife.com, akpm@linux-foundation.org Subject: [PATCH] prevent powerpc from invoking irq handlers on offline CPUs Message-ID: <20080831173127.GA15296@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Make powerpc refrain from clearing a given to-be-offlined CPU's bit in the cpu_online_mask until it has processed pending irqs. This change prevents other CPUs from being blindsided by an apparently offline CPU nevertheless changing globally visible state. Signed-off-by: Paul E. McKenney --- smp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 5337ca7..1fedd7d 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -250,11 +250,11 @@ int generic_cpu_disable(void) if (cpu == boot_cpuid) return -EBUSY; - cpu_clear(cpu, cpu_online_map); #ifdef CONFIG_PPC64 vdso_data->processorCount--; fixup_irqs(cpu_online_map); #endif + cpu_clear(cpu, cpu_online_map); return 0; }