optional barriers turn off
Score-P doesn't use barriers in its instrumentation. In case of automatic instrumentation it would result in extremely high overhead. It means that it is not possible to measure the resources consumption precisely. On the other hand in case of some application (eg. master-slave algorithms) it is necessary not to use barriers.
For MERIC it is possible to turn off OpenMP barriers easily (probably). Removing MPI barriers would require more drastic code changes.