From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756120AbYHaR20 (ORCPT ); Sun, 31 Aug 2008 13:28:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754415AbYHaR2S (ORCPT ); Sun, 31 Aug 2008 13:28:18 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:46696 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754371AbYHaR2R (ORCPT ); Sun, 31 Aug 2008 13:28:17 -0400 Date: Sun, 31 Aug 2008 10:28:14 -0700 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: tony.luck@intel.com, jes@sgi.com, manfred@colorfullife.com, akpm@linux-foundation.org Subject: [PATCH] prevent ia64 from invoking irq handlers on offline CPUs Message-ID: <20080831172814.GA15087@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 ia64 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 --- smpboot.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c index bcea81e..7a90f42 100644 --- a/arch/ia64/kernel/smpboot.c +++ b/arch/ia64/kernel/smpboot.c @@ -741,8 +741,6 @@ int __cpu_disable(void) return -EBUSY; } - cpu_clear(cpu, cpu_online_map); - if (migrate_platform_irqs(cpu)) { cpu_set(cpu, cpu_online_map); return (-EBUSY); @@ -751,6 +749,7 @@ int __cpu_disable(void) remove_siblinginfo(cpu); cpu_clear(cpu, cpu_online_map); fixup_irqs(); + cpu_clear(cpu, cpu_online_map); local_flush_tlb_all(); cpu_clear(cpu, cpu_callin_map); return 0;