Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755559AbZJRXQZ (ORCPT ); Sun, 18 Oct 2009 19:16:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754774AbZJRXQZ (ORCPT ); Sun, 18 Oct 2009 19:16:25 -0400 Received: from tomts20.bellnexxia.net ([209.226.175.74]:60647 "EHLO tomts20-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753781AbZJRXQY (ORCPT ); Sun, 18 Oct 2009 19:16:24 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AsYEAL4720pMRK1g/2dsb2JhbACBU9dqhDEEhFA Date: Sun, 18 Oct 2009 19:16:24 -0400 From: Mathieu Desnoyers To: Pavel Machek Cc: Pierre Habouzit , Steven Munroe , rp@svcs.cs.pdx.edu, linux-kernel@vger.kernel.org, Josh Triplett , ltt-dev@lists.casi.polymtl.ca, Jon Bernard , "Paul E. McKenney" , Jan Blunck Subject: Re: [ltt-dev] [rp] Userspace RCU 0.2.3 Message-ID: <20091018231624.GC5946@Krystal> References: <20091014223657.GC6458@Krystal> <20091015000225.GG6763@linux.vnet.ibm.com> <20091015023925.GA27959@Krystal> <20091015090042.GA7677@feather> <4AD75EA6.8080809@polymtl.ca> <20091017171615.GD1526@ucw.cz> <20091018220243.GA32405@Krystal> <20091018225234.GA9164@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <20091018225234.GA9164@elf.ucw.cz> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.27.31-grsec (i686) X-Uptime: 19:15:59 up 61 days, 10:05, 3 users, load average: 0.50, 0.66, 0.57 User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2087 Lines: 57 * Pavel Machek (pavel@ucw.cz) wrote: > On Sun 2009-10-18 18:02:43, Mathieu Desnoyers wrote: > > * Pavel Machek (pavel@ucw.cz) wrote: > > > On Thu 2009-10-15 13:40:54, Pierre-Marc Fournier wrote: > > > > Josh Triplett wrote: > > > > > > > > > > Even Debian has given up on real 386 systems at this point, primarily > > > > > because system libraries like glibc have; 486 and better represents the > > > > > bare minimum required at this point. I don't know of any distributions > > > > > supporting real 386 systems at this point, and doing so would represent > > > > > a major undertaking. > > > > > > > > > > > > > What about embedded systems? Anyone know if some 386 chips, perhaps even > > > > in smp configurations, are still in use in those? > > > > > > smp 386: definitely not. > > > > Hrm, so for UP 386, I wonder what's the best approach. > > > > One would be to encapsulate all write accesses to the RCU pointers. If > > we detect that the architecture lacks cmpxchg, _all_ update operations > > (rcu_assign_pointer, rcu_xchg_pointer and rcu_cmpxchg_pointer) would > > have to use the signal-disabled+mutex fall-back. > > > > Does it make sense ? > > Yep, but it sounds expensive. Another option is to ignore the issue > and see how many people still have 386s :-). Few embedded systems > may be affected, but... > I can keep that as a special build option, e.g. target: i386 Mathieu > Pavel > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html > > _______________________________________________ > ltt-dev mailing list > ltt-dev@lists.casi.polymtl.ca > http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev > -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 -- 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/