MPI_Compare_and_swap failing on master

[nrgraham23]

MPI_Compare_and_swap is currently failing on master. There is no C test for this method which is probably why it has not been noticed yet. The issue was reported by @gundramleifert on the ompi-users mailing list: https://www.mail-archive.com/users@lists.open-mpi.org/msg29988.html who found it while running the Java tests.

I pulled the C test I used to make the Java test and got the following output:

[mu0687:6378] *** An error occurred in MPI_Compare_and_swap
[mu0687:6378] *** reported by process [1329856513,1]
[mu0687:6378] *** on win rdma window 3
[mu0687:6378] *** MPI_ERR_RMA_RANGE: invalid RMA address range
[mu0687:6378] *** MPI_ERRORS_ARE_FATAL (processes in this win will now abort,
[mu0687:6378] *** and potentially your MPI job)

The problem is fixed by setting: export OMPI_MCA_osc=pt2pt

This can be reproduced on Mustang.