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

[Andrea Parri]

On Mon, Jun 25, 2018 at 09:32:29AM +0200, Peter Zijlstra wrote:
> 
> 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.

I don't see how this is relevant here; roughly, "if something is guaranteed
by a control-dependency, that is also guaranteed by an acquire".  Right? ;)

  Andrea