From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner+willy=40w.ods.org-S266474AbUGPEJt@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S266474AbUGPEJt (ORCPT <rfc822;willy@w.ods.org>);
	Fri, 16 Jul 2004 00:09:49 -0400
Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266472AbUGPEJt
	(ORCPT <rfc822;linux-kernel-outgoing>);
	Fri, 16 Jul 2004 00:09:49 -0400
Received: from smtp105.mail.sc5.yahoo.com ([66.163.169.225]:40373 "HELO
	smtp105.mail.sc5.yahoo.com") by vger.kernel.org with SMTP
	id S267534AbUGPDqm (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Thu, 15 Jul 2004 23:46:42 -0400
Message-ID: <40F74F9C.8080205@yahoo.com.au>
Date: Fri, 16 Jul 2004 13:46:36 +1000
From: Nick Piggin <nickpiggin@yahoo.com.au>
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7) Gecko/20040707 Debian/1.7-5
X-Accept-Language: en
MIME-Version: 1.0
To: Dave Hansen <haveblue@us.ibm.com>
CC: "Matthew C. Dobson [imap]" <colpatch@us.ibm.com>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: sched domains bringup race?
References: <1089944026.32312.47.camel@nighthawk>	 <40F74599.7000606@yahoo.com.au> <1089948659.6886.2.camel@nighthawk>
In-Reply-To: <1089948659.6886.2.camel@nighthawk>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
X-Mailing-List: linux-kernel@vger.kernel.org

Dave Hansen wrote:
> On Thu, 2004-07-15 at 20:03, Nick Piggin wrote:
> 
>>It shouldn't because sched_init sets up dummy domains for
>>all runqueues.
>>
>>Obviously something is going wrong somewhere though.
> 
> 
> Hmmm, but there still might be some concurrency problems, right?  There
> isn't any locking while the setup is being done, so are all of the
> intermediate initialization states valid?  Or, could one of the CPUs be
> catching the init code in the middle of an operation?
> 

cpu_attach_domain is supposed to be able to do the switchover
without any races.