Increase heuristic threshold and get pagesize from runtime
Increase heuristic threshold and get pagesize from runtime

A few mods to Brad's work:
 - Increase threshold from a single pagesize to (maxTaskPar * pagesize)
 - Get pagesize from the runtime rather than hardcoding
   - Should the locale model provide access to the pagesize?
 - Update comments to include motivation and justification for the heuristic

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