Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753164AbYJ0QqR (ORCPT ); Mon, 27 Oct 2008 12:46:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751208AbYJ0QqF (ORCPT ); Mon, 27 Oct 2008 12:46:05 -0400 Received: from e6.ny.us.ibm.com ([32.97.182.146]:47509 "EHLO e6.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750842AbYJ0QqE (ORCPT ); Mon, 27 Oct 2008 12:46:04 -0400 Date: Mon, 27 Oct 2008 09:45:29 -0700 From: "Paul E. McKenney" To: Manfred Spraul Cc: linux-kernel@vger.kernel.org, cl@linux-foundation.org, mingo@elte.hu, akpm@linux-foundation.org, dipankar@in.ibm.com, josht@linux.vnet.ibm.com, schamp@sgi.com, niv@us.ibm.com, dvhltc@us.ibm.com, ego@in.ibm.com, laijs@cn.fujitsu.com, rostedt@goodmis.org, peterz@infradead.org, penberg@cs.helsinki.fi, andi@firstfloor.org, tglx@linutronix.de Subject: Re: [PATCH, RFC] v7 scalable classic RCU implementation Message-ID: <20081027164529.GC6783@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20081010160930.GA9777@linux.vnet.ibm.com> <48F21D58.3000404@colorfullife.com> <20081012224629.GA7353@linux.vnet.ibm.com> <48F38D73.8040804@colorfullife.com> <20081015011143.GE6874@linux.vnet.ibm.com> <48F5A638.8020003@colorfullife.com> <20081015152637.GA6739@linux.vnet.ibm.com> <48FF73C7.90709@colorfullife.com> <20081022210254.GE6766@linux.vnet.ibm.com> <48FF9A0E.90205@colorfullife.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48FF9A0E.90205@colorfullife.com> 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: 1173 Lines: 32 On Wed, Oct 22, 2008 at 11:24:30PM +0200, Manfred Spraul wrote: > Paul E. McKenney wrote: >> Hmmm... Looks like rcu_pending is also always called with its cpu >> parameter set to the current CPU, and same for rcu_needs_cpu(). >> And given that all the external uses of rcu_check_callbacks() are >> of the following form: >> >> if (rcu_pending(cpu)) >> rcu_check_callbacks(cpu, whatever); >> >> >> perhaps rcu_pending() should be an internal-to-RCU API invoked from >> rcu_check_callbacks(). >> >> Thoughts? >> > From my point of view: Yes, change it. > > In the long run, I'd like to move the stall detector code to rcupdate.c, > with an 'rcu_cpu_missing' callback. That one would need a cpu flag, but > that's a new function. Agreed. Perhaps a good change to make while introducing stall detection to preemptable RCU -- there would then be three examples, which should allow good generalization. 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/