From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751931Ab3LLEKy (ORCPT ); Wed, 11 Dec 2013 23:10:54 -0500 Received: from relay3-d.mail.gandi.net ([217.70.183.195]:60372 "EHLO relay3-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751851Ab3LLEKw (ORCPT ); Wed, 11 Dec 2013 23:10:52 -0500 X-Originating-IP: 50.43.14.201 Date: Wed, 11 Dec 2013 20:10:37 -0800 From: Josh Triplett To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, darren@dvhart.com, fweisbec@gmail.com, oleg@redhat.com, sbw@mit.edu Subject: Re: [PATCH v2 tip/core/rcu 0/4] Documentation changes for 3.14 Message-ID: <20131212041037.GA21050@leaf> References: <20131211230823.GA12448@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131211230823.GA12448@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 11, 2013 at 03:08:23PM -0800, Paul E. McKenney wrote: > Hello! > > This series once again attempts to improve rcu_assign_pointer()'s > relationship with sparse. > > 1. Add a comment indicating that despite appearances, > rcu_assign_pointer() really only evaluates its arguments once, > as a cpp macro should. > > 2. Replace rcu_assign_pointer() of NULL with RCU_INIT_POINTER() to > silence a sparse warning. > > 3. Apply ACCESS_ONCE() to rcu_assign_pointer()'s target to prevent > comiler mischief. Also require that the source pointer be from > the kernel address space. Sometimes it can be from the RCU address > space, which necessitates the remaining patches in this series. > Which, it must be admitted, apply to a very small fraction of > the rcu_assign_pointer() invocations in the kernel. This commit > courtesy of Josh Triplett. > > 4. Add an RCU_INITIALIZER() for compile-time initialization of > global RCU-protected pointers. For all the patches (other than the one I wrote, for obvious reasons): Reviewed-by: Josh Triplett