What: I want to add another member to mca_mpool_base_registration_t for mpools that
need to keep track of extra context data.
Why: I plan to add a new mpool to support Cray's udreg registration cache. This new
mpool will allow us to turn off the memory hooks on Cray systems. Unfortunately, in
order to get the symantics right I need to keep track of the udreg context for the base
registration. Originally, I subclassed the base registration and put the context in
there but it makes switching mpools more awkward than it already is. I want to move
this pointer down to the base registration as void *mpool_context for both trunk
and 1.7.4 (the target for the new mpool).
When: This is a small change and shouldn't have much impact on the code base but I would
like some feedback on this change before committing it. Timeout set for next Tuesday