COLL_APPLY(action, COLL_GATHER_SIG, ompi_linear_sync) COLL_sep \
COLL_APPLY(action, COLL_GATHER_SIG, mpich) COLL_sep \
COLL_APPLY(action, COLL_GATHER_SIG, mvapich2) COLL_sep \
+COLL_APPLY(action, COLL_GATHER_SIG, mvapich2_two_level) COLL_sep \
COLL_APPLY(action, COLL_GATHER_SIG, impi) COLL_sep \
COLL_APPLY(action, COLL_GATHER_SIG, automatic)