Avoid setting up an MPI data type for serial comm

diff --git a/source/base/mpi.cc b/source/base/mpi.cc
index 400a7874401e047bbfa6459c807433c1cf4fdf57..334453313efa9e2c5f00ff7c3671cb243cdc8a0d 100644 (file)
--- a/source/base/mpi.cc
+++ b/source/base/mpi.cc
@@ -531,7 +531,8 @@ namespace Utilities
     {
       // If MPI was not started, we have a serial computation and cannot run
       // the other MPI commands
-      if (job_supports_mpi() == false)
+      if (job_supports_mpi() == false ||
+          Utilities::MPI::n_mpi_processes(mpi_communicator) <= 1)
         {
           MinMaxAvg result;
           result.sum       = my_value;