Re: [PATCH tip/core/rcu 2/3] rcu: make hot-unplugged CPUrelinquish its own RCU callbacks

[Paul E. McKenney]

On Wed, Oct 07, 2009 at 09:16:12AM -0400, Steven Rostedt wrote:
> Paul,
> 
> Still suffering jetlag? ;-)

As a matter of fact, yes.  ;-)

> On Tue, 2009-10-06 at 21:48 -0700, Paul E. McKenney wrote:
> > From: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
> > 
> > The current interaction between RCU and CPU hotplug requires that
> > RCU block in CPU notifiers waiting for callbacks to drain.  This can
> > be greatly simplified by haing each CPU relinquish its own callbacks,
>                            having
> 
> > and for both _rcu_barrier() and CPU_DEAD notifiers to adopt all callbacks
> > that were previously relinquished.  This change also eliminates the
> > possibility of certain types of hangs due to the previous practice of
> > waiting for callbacks to be invoked from within CPU notifiers.  If you
> > don't every wait, you cannot hang.
>         ever
> 
> ;-)

Courtesy of "git cherry-pick" and my being out of it.  ;-)

							Thanx, Paul

> > Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
> 
> -- Steve
> 
> 
--
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/