Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 24 Apr 2019 11:31:07 -0700
From:   "Paul E. McKenney" <paulmck@linux.ibm.com>
To:     Alan Stern <stern@rowland.harvard.edu>
Cc:     LKMM Maintainers -- Akira Yokosawa <akiyks@gmail.com>,
        Andrea Parri <andrea.parri@amarulasolutions.com>,
        Boqun Feng <boqun.feng@gmail.com>,
        Daniel Lustig <dlustig@nvidia.com>,
        David Howells <dhowells@redhat.com>,
        Jade Alglave <j.alglave@ucl.ac.uk>,
        Luc Maranget <luc.maranget@inria.fr>,
        Nicholas Piggin <npiggin@gmail.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Will Deacon <will.deacon@arm.com>,
        Kernel development list <linux-kernel@vger.kernel.org>,
        Joel Fernandes <joel@joelfernandes.org>
Subject: Re: [PATCH 1/3] tools: memory-model: Prepare for data-race detection
Reply-To: paulmck@linux.ibm.com
References: <20190424082231.GF3923@linux.ibm.com>
 <Pine.LNX.4.44L0.1904241023380.1443-100000@iolanthe.rowland.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <Pine.LNX.4.44L0.1904241023380.1443-100000@iolanthe.rowland.org>
User-Agent: Mutt/1.5.21 (2010-09-15)
Message-Id: <20190424183107.GN3923@linux.ibm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, Apr 24, 2019 at 10:24:42AM -0400, Alan Stern wrote:
> On Wed, 24 Apr 2019, Paul E. McKenney wrote:
> 
> > On Mon, Apr 22, 2019 at 12:17:45PM -0400, Alan Stern wrote:
> > > This patch makes some slight alterations to linux-kernel.cat in
> > > preparation for adding support for data-race detection to the
> > > Linux-Kernel Memory Model.
> > > 
> > > 	The definitions of relations involved in Acquire, Release, and
> > > 	unlock-lock ordering are moved up earlier in the source file.
> > > 
> > > 	The rmb relation is factored through the new R4rmb class: the
> > > 	class of reads to which rmb will apply.
> > > 
> > > 	The definition of the fence relation is moved earlier, and it
> > > 	is split up into read- and write-fences (rmb and wmb) and all
> > > 	the others.
> > > 
> > > This should not make any functional changes.
> > > 
> > > Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
> > 
> > Thank you, Alan, I have queued all three onto -rcu for review and testing.
> > FYI, I rebased my smp_mb__{before,after}_atomic() patch on top of yours
> > to avoid the conflict.
> > 
> > Which demonstrates non-commutativity of patches.  Your patches conflict
> > with mine, but mine does not conflict with yours.  ;-)
> 
> :-)
> 
> Besides, who knows where we'll end up with the 
> smp_mb__{before,after}_atomic stuff once Peter is done with it, anyway?

True enough!

							Thanx, Paul