Re: linux-next: build failure after merge of the rcu tree

Paul E. McKenney
2017-08-11T14:39:37Z

On Fri, Aug 11, 2017 at 11:14:34AM +0200, Peter Zijlstra wrote:
> On Thu, Aug 10, 2017 at 09:54:53PM -0700, Paul E. McKenney wrote:
> > On Fri, Aug 11, 2017 at 02:43:52PM +1000, Stephen Rothwell wrote:
> >
> > Looks like I need to rebase my patch on top of a9668cd6ee28, and
> > than put an smp_mb__after_spinlock() between the lock and the unlock.
> >
> > Peter, any objections to that approach? Other suggestions?
>
> Hurm.. I'll have to try and understand that comment there again it
> seems.

My reasoning is as follows:

1. The critical section is empty, so any prior references
would be ordered only against later critical sections.

2. A full barrier within the critical section will order those
prior references against later critical sections just
as easily as would one prior to the critical section.

Does that make sense, I should I have stayed away from the keyboard
at this early hour? ;-)

Thanx, Paul