Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751563AbZJOEem (ORCPT ); Thu, 15 Oct 2009 00:34:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751452AbZJOEem (ORCPT ); Thu, 15 Oct 2009 00:34:42 -0400 Received: from e2.ny.us.ibm.com ([32.97.182.142]:47275 "EHLO e2.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751437AbZJOEel (ORCPT ); Thu, 15 Oct 2009 00:34:41 -0400 Date: Wed, 14 Oct 2009 21:34:02 -0700 From: "Paul E. McKenney" To: Mathieu Desnoyers Cc: Josh Triplett , Jon Bernard , Jan Blunck , Pierre Habouzit , Steven Munroe , Bert Wesarg , Pierre-Marc Fournier , ltt-dev@lists.casi.polymtl.ca, rp@svcs.cs.pdx.edu, linux-kernel@vger.kernel.org Subject: Re: Userspace RCU 0.2.3 Message-ID: <20091015043402.GA6837@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20091014223657.GC6458@Krystal> <20091015000225.GG6763@linux.vnet.ibm.com> <20091015023925.GA27959@Krystal> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091015023925.GA27959@Krystal> 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 Content-Length: 1504 Lines: 37 On Wed, Oct 14, 2009 at 10:39:25PM -0400, Mathieu Desnoyers wrote: > * Paul E. McKenney (paulmck@linux.vnet.ibm.com) wrote: > > On Wed, Oct 14, 2009 at 06:36:57PM -0400, Mathieu Desnoyers wrote: > > > Hi, > > > > > > I just released lib urcu 0.2.3, which is now using autotools. I also > > > integrated automatic architecture detection for old 386 which lack > > > cmpxchg (using a fall-back if necessary). I also use a lock; addl > > > instead of mfence on x86-32 to support a larger variety of older Intel > > > CPUs. > > > > !!! > > > > Is there anyone on these lists other than me who has actually used an > > SMP 80386-based system? > > SMP 386, ugh, no. But UP 386 yes (at least me). :) > > It will become important as the library gets integrated in > distributions. > > > Either way, much appreciated for old time's sake. The things we used > > to do to avoid the need for cmpxchg! ;-) > > In this case I disable signals and take a mutex around the cmpxchg. It's > really a best effort. Should be fine on UP 386, but not so much on SMP > 386, as mixing it with assign/xchg pointer could lead to races. I'm not > sure it's worth trying to support 386 SMP though. Definitely not worth much, if anything, to support 386 SMP. 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/