On Fri, 2017-04-21 at 15:26 -0700, Jeff Hammond wrote:

MPIR_CVAR_NOLOCAL=1.

OK, thanks Jeff that was indeed the difference. I can confirm that with NOLOCAL, some processes are stuck in BARRIER while one process is stuck in MPI_Waitsome valgrind doesn't give any help here. I hope someone more familiar with the collectives can suggest a fix. For now, I've triaged this in issue #2609 https://github.com/pmodels/mpich/issues/2609 ==rob _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss