Re: [PATCH RFC tip/core/rcu] SRCU rewrite

[Peter Zijlstra]

On Tue, Nov 15, 2016 at 06:26:27AM -0800, Paul E. McKenney wrote:
> On Tue, Nov 15, 2016 at 02:59:12PM +0100, Peter Zijlstra wrote:

> > The smp_mb()s in read_{un,}lock() and the lock in call_srcu() come to
> > mind.
> 
> There is some possibility of weakening the srcu_read_unlock() ordering,
> but one step at a time.
> 
> Has the lock in call_srcu() been causing trouble?  Easy to fix if so,
> but as you noted in another email today, we don't need complexity for
> complexity's sake.  And no reports of problems with this have reached
> me thus far.

It was a cause for concern in the optimistic fault series, but since
that never got sorted, it hasn't shown up in practise afaik.