From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Subject: Re: [PATCH v2 tip/core/rcu 0/13] Sparse-related updates for 3.13 Date: Wed, 9 Oct 2013 15:46:24 -0700 Message-ID: <20131009224624.GG5790@linux.vnet.ibm.com> References: <20131009212920.GA15413@linux.vnet.ibm.com> <20131009221805.GA11709@jtriplet-mobl1> Reply-To: paulmck@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: peterz@infradead.org, fweisbec@gmail.com, dhowells@redhat.com, edumazet@google.com, gaofeng@cn.fujitsu.com, mingo@kernel.org, bridge@lists.linux-foundation.org, jmorris@namei.org, dipankar@in.ibm.com, darren@dvhart.com, rostedt@goodmis.org, niv@us.ibm.com, mathieu.desnoyers@efficios.com, kuznet@ms2.inr.ac.ru, tglx@linutronix.de, johannes@sipsolutions.net, laijs@cn.fujitsu.com, yoshfuji@linux-ipv6.org, netdev@vger.kernel.org, linux-decnet-user@lists.sourceforge.net, linux-kernel@vger.kernel.org, kaber@trash.net, stephen@networkplumber.org, sbw@mit.edu, tgraf@suug.ch, akpm@linux-foundation.org, fengguang.wu@intel.com, davem@davemloft.net To: Josh Triplett Return-path: Content-Disposition: inline In-Reply-To: <20131009221805.GA11709@jtriplet-mobl1> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: bridge-bounces@lists.linux-foundation.org Errors-To: bridge-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org On Wed, Oct 09, 2013 at 03:18:05PM -0700, Josh Triplett wrote: > 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. That would help with bisectability, will do! Thanx, Paul