Thomas Zeiser

Some comments by Thomas Zeiser about HPC@RRZE and other things


minor modifications to RRZE’s mpirun wrapper

For certain applications and processor numbers, there were problems with hanging MPI processes in the startup phase when using Intel MPI together with PBS’s mpiexec and I_MPI_DEVICE=rdssm. Therefore, we changed the default I_MPI_DEVICE for Woody, Townsend and TinyBlue from rdssm to rdma. In practice, one should not see any difference as rdssm with recent versions of Intel MPI did not use shm but rdma also within the node.

Single node jobs on Woody and TinyBlue using Intel MPI and our mpirun wrapper will from now on use shm by default if exactly one node was requested for the PBS jobs.

additional settings for mvapich2:

To make our -pin argument work with recent mvapich2 versions, we recently added a default of MV2_ENABLE_AFFINITY=0 to our mpirun wrapper.