Date:   Wed, 22 Feb 2023 15:32:12 -0500
From:   Alan Stern <stern@rowland.harvard.edu>
To:     "Paul E. McKenney" <paulmck@kernel.org>
Cc:     Joel Fernandes <joel@joelfernandes.org>,
        linux-kernel@vger.kernel.org, Boqun Feng <boqun.feng@gmail.com>,
        Jade Alglave <j.alglave@ucl.ac.uk>,
        Luc Maranget <luc.maranget@inria.fr>,
        Peter Zijlstra <peterz@infradead.org>,
        Will Deacon <will.deacon@arm.com>,
        Jonas Oberhauser <jonas.oberhauser@huaweicloud.com>,
        Akira Yokosawa <akiyks@gmail.com>,
        Andrea Parri <parri.andrea@gmail.com>,
        Daniel Lustig <dlustig@nvidia.com>,
        David Howells <dhowells@redhat.com>,
        Jonas Oberhauser <jonas.oberhauser@huawei.com>,
        linux-arch@vger.kernel.org, Nicholas Piggin <npiggin@gmail.com>,
        Paul =?iso-8859-1?Q?Heidekr=FCger?= <paul.heidekrueger@in.tum.de>,
        Will Deacon <will@kernel.org>
Subject: Re: [PATCH] tools/memory-model: Add details about SRCU read-side
 critical sections
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On Wed, Feb 22, 2023 at 11:50:51AM -0800, Paul E. McKenney wrote:
> On Mon, Feb 20, 2023 at 04:06:13PM -0500, Alan Stern wrote:
> > On Sun, Feb 19, 2023 at 12:13:14PM -0500, Joel Fernandes wrote:
> > > On Sun, Feb 19, 2023 at 12:11 PM Joel Fernandes <joel@joelfernandes.org> wrote:
> > > > Even though it may be redundant: would it be possible to also mention
> > > > (after this paragraph) that this case forms an undesirable "->rf" link
> > > > between B and C, which then causes us to link A and D as a result?
> > > >
> > > > A[srcu-lock] ->data B[once] ->rf C[once] ->data D[srcu-unlock].
> > > 
> > > Apologies, I meant here, care must be taken to avoid:
> > > 
> > > A[srcu-lock] ->data B[srcu-unlock] ->rf C[srcu-lock] ->data D[srcu-unlock].
> > 
> > Revised patch below.  I changed more than just this bit.  Mostly small 
> > edits to improve readability, but I did add a little additional 
> > material.
> 
> Looks good to me, thank you!
> 
> Would you like to send a formal patch, or are you thinking in terms
> of making other changes first?

I'll send a formal patch when I find time to write an appropriate 
Changelog description.

I also have in mind making other changes along the lines Joel suggested, 
but they will be separate patches.

Alan