Re: [PATCH v3 tip/core/rcu 3/9] rcu: Add synchronous grace-period waiting for RCU-tasks

Paul E. McKenney
2014-08-01T18:33:00Z

On Fri, Aug 01, 2014 at 05:09:26PM +0200, Oleg Nesterov wrote:
> On 07/31, Paul E. McKenney wrote:
> >
> > +void synchronize_rcu_tasks(void)
> > +{
> > + /* Complain if the scheduler has not started. */
> > + rcu_lockdep_assert(!rcu_scheduler_active,
> > + "synchronize_rcu_tasks called too soon");
> > +
> > + /* Wait for the grace period. */
> > + wait_rcu_gp(call_rcu_tasks);
> > +}
>
> Btw, what about CONFIG_PREEMPT=n ?
>
> I mean, can't synchronize_rcu_tasks() be synchronize_sched() in this
> case?

Excellent point, indeed it can!

And if I do it right, it will make CONFIG_TASKS_RCU=y safe for kernel
tinification. ;-)

Thanx, Paul