Re: [PATCH tip/core/rcu 01/14] rcu: Protect rcu_boost() lockless accesses with ACCESS_ONCE()

[Peter Zijlstra]

On Fri, Jan 09, 2015 at 05:49:54AM -0800, Paul E. McKenney wrote:
> > That reminds me, I think the new conversion for stores will most likely
> > introduce silly arg bugs:
> > 
> > -       ACCESS_ONCE(a) = b;
> > +       ASSIGN_ONCE(b, a);
> 
> I was planning to do mine by hand for this sort of reason.
> 
> Or are you thinking of something more subtle than the case where
> "b" is an unparenthesized comma-separated expression?

I think he's revering to the wrong way around-ness of the thing.

Its a bit of a mixed bag on assignments, but for instance
rcu_assign_pointer() takes them the right way around, as does
atomic_set().

So yes, I think the ASSIGN_ONCE() thing got the arguments the wrong way
around.

We could maybe still change it, before its in too long ?
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