[OMPI users] Tuned Collective MCA params

[Eric Thibodeau]

Hello all,

   I am currently profiling a simple case where I replace multiple S/R 
calls with Allgather calls and it would _seem_ the simple S/R calls are 
faster. Now, *before* I come to any conclusion on this, one of the 
pieces I am missing is more details on how /if/when the tuned coll MCA 
is selected. In other words, can I assume the tuned versions are used by 
default? I skimmed through the well documented source code but before I 
can even start to analyze the replacement's impact (in a small cluster), 
I need to know how and when the tuned coll MCA is used/selected.

Thanks,

Eric