Add variant to mvapich2 to control thread level (#3832)
Add variant to mvapich2 to control thread level (#3832)


LLNL/spack,iulian787/spack,skosukhin/spack,matthiasdiener/spack,TheTimmy/spack,lgarren/spack,iulian787/spack,mfherbst/spack,matthiasdiener/spack,matthiasdiener/spack,EmreAtes/spack,mfherbst/spack,mfherbst/spack,krafczyk/spack,mfherbst/spack,LLNL/spack,tmerrick1/spack,EmreAtes/spack,tmerrick1/spack,TheTimmy/spack,krafczyk/spack,tmerrick1/spack,skosukhin/spack,iulian787/spack,tmerrick1/spack,EmreAtes/spack,lgarren/spack,lgarren/spack,matthiasdiener/spack,EmreAtes/spack,krafczyk/spack,LLNL/spack,LLNL/spack,TheTimmy/spack,EmreAtes/spack,iulian787/spack,tmerrick1/spack,lgarren/spack,skosukhin/spack,iulian787/spack,krafczyk/spack,lgarren/spack,mfherbst/spack,LLNL/spack,matthiasdiener/spack,skosukhin/spack,TheTimmy/spack,TheTimmy/spack,skosukhin/spack,krafczyk/spack