Re: [PATCH v2] membarrier: Document scheduler barrier requirements

[Paul E. McKenney]

On Mon, Aug 21, 2017 at 10:42:36AM +0200, Peter Zijlstra wrote:
> On Fri, Aug 18, 2017 at 09:39:16PM -0700, Mathieu Desnoyers wrote:
> > @@ -3295,6 +3301,9 @@ static void __sched notrace __schedule(bool preempt)
> >  	 * Make sure that signal_pending_state()->signal_pending() below
> >  	 * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE)
> >  	 * done by the caller to avoid the race with signal_wake_up().
> > +	 *
> > +	 * The membarrier system call requires a full memory barrier
> > +	 * after coming from user-space, before storing to rq->curr.
> >  	 */
> >  	smp_mb__before_spinlock();
> >  	rq_lock(rq, &rf);
> 
> Merge conflict here, current tip is over to smp_mb__after_spinlock().

Would some tree other than -rcu be better for that commit?

							Thanx, Paul