From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757949Ab0LUH6i (ORCPT ); Tue, 21 Dec 2010 02:58:38 -0500 Received: from e9.ny.us.ibm.com ([32.97.182.139]:35071 "EHLO e9.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754006Ab0LUH6h (ORCPT ); Tue, 21 Dec 2010 02:58:37 -0500 Date: Mon, 20 Dec 2010 23:58:28 -0800 From: "Paul E. McKenney" To: Peter Zijlstra Cc: Tejun Heo , linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com Subject: Re: [PATCH RFC tip/core/rcu 13/20] rcu: increase synchronize_sched_expedited() batching Message-ID: <20101221075828.GJ2143@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20101217205433.GA10199@linux.vnet.ibm.com> <1292619291-2468-13-git-send-email-paulmck@linux.vnet.ibm.com> <4D0CDD93.7040907@kernel.org> <20101218201419.GD2143@linux.vnet.ibm.com> <4D0DD3D2.4030606@kernel.org> <1292841080.2708.134.camel@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1292841080.2708.134.camel@laptop> User-Agent: Mutt/1.5.20 (2009-06-14) X-Content-Scanned: Fidelis XPS MAILER Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 20, 2010 at 11:31:20AM +0100, Peter Zijlstra wrote: > On Sun, 2010-12-19 at 10:43 +0100, Tejun Heo wrote: > > > > I see, then would something like the following work? > > > > (int)((unsigned)(a) - (unsigned)(b)) < 0 > > Note that there is lots of kernel code that does the above and > variations thereof and expects it to work. Given that the approach I have been using is the same number of lines and avoids relying on this expectation, I will stick with it. Thanx, Paul