Re: [PATCH 2/2] tools/memory-model: Add write ordering by release-acquire and by locks

[Peter Zijlstra]

I have yet to digest the rest of the discussion, however:

On Fri, Jun 22, 2018 at 02:09:04PM -0400, Alan Stern wrote:
> The LKMM uses the same CAT code for acquire/release and lock/unlock.
> (In essence, it considers a lock to be an acquire and an unlock to be a
> release; everything else follows from that.)  Treating one differently
> from the other in these tests would require some significant changes.
> It wouldn't be easy.

That is problematic, acquire+release are very much simpler operations
than lock+unlock.

At the very least, lock includes a control-dependency, where acquire
does not.