From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031699AbXFHToU (ORCPT ); Fri, 8 Jun 2007 15:44:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756900AbXFHToM (ORCPT ); Fri, 8 Jun 2007 15:44:12 -0400 Received: from mail.suse.de ([195.135.220.2]:56215 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751315AbXFHToL (ORCPT ); Fri, 8 Jun 2007 15:44:11 -0400 From: Andi Kleen Organization: SUSE Linux Products GmbH, Nuernberg, GF: Markus Rex, HRB 16746 (AG Nuernberg) To: "Satyam Sharma" Subject: Re: [patch] i386/x86_64: smp_call_function locking inconsistency Date: Fri, 8 Jun 2007 21:43:51 +0200 User-Agent: KMail/1.9.6 Cc: "Heiko Carstens" , "Jan Glauber" , "David Miller" , akpm@osdl.org, mingo@elte.hu, schwidefsky@de.ibm.com, linux-kernel@vger.kernel.org, "Alan Cox" References: <20070208203210.GB9798@osiris.ibm.com> <20070607162743.GA9433@osiris.ibm.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200706082143.52191.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Indeed -- this was doubly problematic because the un-safeness > was because of smp_processor_id() as well as the (eventual) > access of cpu_online_map (via smp_call_function() -> > num_online_cpus()) ... thanks for letting me know about this. CPU hotplug is changed to use the freezer anyways. It is known that the current handling of these maps in preempt has various holes and this little case here won't make it overall much worse. -Andi