Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761952AbXKAPuv (ORCPT ); Thu, 1 Nov 2007 11:50:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761319AbXKAPuh (ORCPT ); Thu, 1 Nov 2007 11:50:37 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:46446 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760961AbXKAPug (ORCPT ); Thu, 1 Nov 2007 11:50:36 -0400 Date: Thu, 1 Nov 2007 08:50:28 -0700 From: "Paul E. McKenney" To: Benjamin Herrenschmidt Cc: Darren Hart , linux-kernel@vger.kernel.org, tony@bakeyournoodle.com, paulus@samba.org, dino@in.ibm.com, tytso@us.ibm.com, antonb@us.ibm.com, rostedt@goodmis.org Subject: Re: [PATCH, RFC] hacks to allow -rt to run kernbench on POWER Message-ID: <20071101155028.GB14231@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20071029185044.GA23413@linux.vnet.ibm.com> <1193688468.9928.30.camel@pasglop> <1193864075.9767.20.camel@Aeon> <1193865328.9928.141.camel@pasglop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1193865328.9928.141.camel@pasglop> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1157 Lines: 23 On Thu, Nov 01, 2007 at 08:15:28AM +1100, Benjamin Herrenschmidt wrote: > > > So as Paul mentioned, spin_lock is now a mutex. There is a new > > raw_spinlock however (simply change the way it is declared, calling > > conventions are the same) which is used in a very few areas where a > > traditional spin_lock is truly necessary. This may or may not be one of > > those times, but I wanted to point it out. > > Yeah, I figured that. My main worry has more to do with some fishy > assumptions the powerpc VM code does regarding what can and cannot > happen in those locked sections, among other things. I'll have to sit > and think about it for a little while to convince myself we are ok ... > or not. Plus we do keep track of various MM related things in per-CPU > data structures but it looks like Paul already spotted that. My concern would be that I failed to spot all of them. ;-) Thanx, Paul - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/