From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263174AbUCaBJD (ORCPT ); Tue, 30 Mar 2004 20:09:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263346AbUCaBJC (ORCPT ); Tue, 30 Mar 2004 20:09:02 -0500 Received: from fw.osdl.org ([65.172.181.6]:15772 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S263174AbUCaBI7 (ORCPT ); Tue, 30 Mar 2004 20:08:59 -0500 Date: Tue, 30 Mar 2004 17:11:04 -0800 From: Andrew Morton To: "Martin J. Bligh" Cc: rddunlap@osdl.org, hari@in.ibm.com, linux-kernel@vger.kernel.org, apw@shadowen.org, jamesclv@us.ibm.com Subject: Re: BUG_ON(!cpus_equal(cpumask, tmp)); Message-Id: <20040330171104.752104a9.akpm@osdl.org> In-Reply-To: <270000000.1080694659@flay> References: <006701c415a4$01df0770$d100000a@sbs2003.local> <20040329162123.4c57734d.akpm@osdl.org> <20040329162555.4227bc88.akpm@osdl.org> <20040330132832.GA5552@in.ibm.com> <20040330151729.1bd0c5d0.rddunlap@osdl.org> <187940000.1080692555@flay> <20040330163928.7cafae3d.akpm@osdl.org> <270000000.1080694659@flay> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i586-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org "Martin J. Bligh" wrote: > > I made a similar patch, but I don't see how we can really fix it without > providing locking on cpu_online_map. Are we missing something here? Why does, for example, smp_send_reschedule() not have the same problem? Because we've gone around and correctly removed all references to the CPU from the scheduler data structures before offlining it. But we're not doing that in the mm code, right? Should we not be taking mmlist_lock and running around knocking this CPU out of everyone's cpu_vm_mask before offlining it?