Re: [PATCH v2 tip/core/rcu 01/22] smpboot: Add common code for notification from dying CPU

From: Paul E. McKenney
Date: Tue Mar 17 2015 - 07:36:58 EST


On Tue, Mar 17, 2015 at 09:18:07AM +0100, Peter Zijlstra wrote:
> On Mon, Mar 16, 2015 at 11:37:45AM -0700, Paul E. McKenney wrote:
> > From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
> >
> > RCU ignores offlined CPUs, so they cannot safely run RCU read-side code.
> > (They -can- use SRCU, but not RCU.) This means that any use of RCU
> > during or after the call to arch_cpu_idle_dead(). Unfortunately,
> > commit 2ed53c0d6cc99 added a complete() call, which will contain RCU
> > read-side critical sections if there is a task waiting to be awakened.
>
> Got a little more detail there?

Quite possibly. But exactly what sort of detail are you looking for?

Thanx, Paul

--
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/