Re: [PATCH RFC 6/9] RCU priority boosting for preemptible RCU

[Steven Rostedt <rostedt@goodmis.org>]

--
On Fri, 28 Sep 2007, Gautham R Shenoy wrote:

> >
> > +#ifdef CONFIG_PREEMPT_RCU_BOOST
> > +/*
> > + * Task state with respect to being RCU-boosted.  This state is changed
> > + * by the task itself in response to the following three events:
> 							^^^
> > + * 1. Preemption (or block on lock) while in RCU read-side critical section.
>
> I am wondering, can a task block on a lock while in RCU read-side
> critical section?

I think this may be specific to the -rt patch. In the -rt patch,
spin_locks turn into mutexes, and therefor can block a read-side critical
section.


> > + * 2. Outermost rcu_read_unlock() for blocked RCU read-side critical section.
> > + *
>
> Event #3. is missing?

I guess Paul needs to answer that one ;-)

-- Steve

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