From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josh Triplett Subject: Re: [PATCH v2 tip/core/rcu 0/13] Sparse-related updates for 3.13 Date: Wed, 9 Oct 2013 15:18:05 -0700 Message-ID: <20131009221805.GA11709@jtriplet-mobl1> References: <20131009212920.GA15413@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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, sbw@mit.edu, fengguang.wu@intel.com, stephen@networkplumber.org, davem@davemloft.net, bridge@lists.linux-foundation.org, netdev@vger.kernel.org, tgraf@suug.ch, gaofeng@cn.fujitsu.com, linux-decnet-user@lists.sourceforge.net, kuznet@ms2.inr.ac.ru, jmorris@namei.org, yoshfuji@linux-ipv6.org, kaber@trash.net, linville@tuxdriver.com, johannes@sipsolutions.net To: "Paul E. McKenney" Return-path: Content-Disposition: inline In-Reply-To: <20131009212920.GA15413@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, Oct 09, 2013 at 02:29:20PM -0700, Paul E. McKenney wrote: > Hello! > > This series features updates to allow sparse to do a better job of > statically analyzing RCU usage: > > 1. 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. > > 2-13. Apply rcu_access_pointer() to avoid a number of false positives. I would suggest moving patch 1 to the end of the series, to avoid introducing and subsequently fixing warnings. - Josh Triplett