On Thu, Aug 23, 2007 at 08:55:26AM -0700, Paul E. McKenney wrote:

quoted

Even if we use another cpumask_t, whenever a cpu goes down or comes up,
that will be reflected in this map, no? So what's the additional
advantage of using it?

The additional map allows the code to use something other than the
lock_cpu_hotplug/unlock_cpu_hotplug, and also is robust against any
changes to the hotplug synchronization mechanism.  Might well be
better just to use the current hotplug synchronization mechanism,
but I was feeling paranoid.  ;-)

If it was doing something more complicated in the critical section other
than summing stuff up, I would probably recommend going for another map
instead of using the current hotplug synchronization. But for this case
the current hotplug synchronization would work just fine.

I can very well understand your paranoia, but let me assure you, you are
not the only one ;-)

Regards
gautham.

						Thanx, Paul

-- 
Gautham R Shenoy
Linux Technology Center
IBM India.
"Freedom comes with a price tag of responsibility, which is still a bargain,
because Freedom is priceless!"