Disclosed is an apparatus, method, and program product for identifying and
grouping threads that have interdependent data access needs. The
preferred embodiment of the present invention utilizes two different
constructs to accomplish this grouping. A Memory Affinity Group (MAG) is
disclosed. The MAG construct enables multiple threads to be associated
with the same node without any foreknowledge of which threads will be
involved in the association, and without any control over the particular
node with which they are associated. A Logical Node construct is also
disclosed. The Logical Node construct enables multiple threads to be
associated with the same specified node without any foreknowledge of
which threads will be involved in the association. While logical nodes do
not explicitly identify the underlying physical nodes comprising the
system, they provide a means of associating particular threads with the
same node and other threads with other node(s).