From: Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
Subject: Re: [PATCH v2 08/17] locking/lockdep: Add support for nestable
	terminal locks
Date: Fri, 7 Dec 2018 10:52:17 +0100
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To: Waiman Long <longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Petr Mladek <pmladek-IBi9RG/b67k@public.gmane.org>, Sergey Senozhatsky <sergey.senozhatsky-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kasan-dev-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Ingo Molnar <mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, Andrey Ryabinin <aryabinin-5HdwGun5lf+gSpxsJD1C4w@public.gmane.org>, Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>, Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
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On Fri, Dec 07, 2018 at 10:22:52AM +0100, Peter Zijlstra wrote:
> On Mon, Nov 19, 2018 at 01:55:17PM -0500, Waiman Long wrote:
> > There are use cases where we want to allow nesting of one terminal lock
> > underneath another terminal-like lock. That new lock type is called
> > nestable terminal lock which can optionally allow the acquisition of
> > no more than one regular (non-nestable) terminal lock underneath it.
> 
> I think I asked for a more coherent changelog on this. The above is
> still self contradictory and doesn't explain why you'd ever want such a
> 'misfeature' :-)

So maybe call the thing penterminal (contraction of penultimate and
terminal) locks and explain why this annotation is safe -- in great
detail.