Nth core, so it fell over to try to find the Nth PU.
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hwloc isn't able to find cores on all platforms. Example: PPC64
running RHEL 5.4 (linux kernel 2.6.18) only reports NUMA nodes and
PU's. Fine.
However, note that hwloc_get_obj_by_type() will return NULL in 2
(effectively) different cases:
- no objects of the requested type were found
- the Nth object of the requested type was not found
So first we have to see if we can find *any* cores by looking for the
0th core. If we find it, then try to find the Nth core. Otherwise,
try to find the Nth PU.
This commit was SVN r24632.
b8af3b7c4a