Re: Real-Time Preemption and RCU

[Ingo Molnar]

* Paul E. McKenney <paulmck@xxxxxxxxxx> wrote:

> > > 		preempt_disable();
> > > 		if (current->rcu_read_lock_nesting++ == 0) {
> > > 			current->rcu_read_lock_ptr =
> > > 				&__get_cpu_var(rcu_data).lock;
> > > 			read_lock(current->rcu_read_lock_ptr);
> > > 		}
> > > 		preempt_enable();

> My current thought is that the preempt_disable()/preempt_enable() can
> be dropped entirely.  Messes up any tool that browses through
> ->rcu_read_lock_nesting, but don't see any other problem.  Yet,
> anyway!

yeah - this sounds good. (We are not aiming for irq-safe RCU anyway, on
PREEMPT_RT.)

	Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/