Some have noticed that the overlapping sched domains code doesn't quite work
as intended (it results in disjoint domains on some machines), and that a top
level, machine spanning domain is needed.  This patch from John Hawkes adds
it to the ia64 code.  This allows processes to run on all CPUs in large
systems, though balancing is limited.  It should go to Linus soon now
otherwise large systems will only have ~16p (depending on topology) usable by
the scheduler.  I sanity checked it on a small system after rediffing John's
original, and he's done some testing on very large systems.
 
 Nick, can you buy off on the sched.c change?  Alternatively, do you want to
 send that fix separately John? Nick did indeed ACK this change, but it isn't
 dependent on this ia64 specific part ... so it's going to be submitted
 separately.
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Jesse Barnes <jbarnes@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>