mpi_coll_allgatherv_fun = (int (*)(void *, int, MPI_Datatype, void *, int *, int *, MPI_Datatype, MPI_Comm))
mpi_coll_allgatherv_description[allgatherv_id].coll;
int allreduce_id = find_coll_description(mpi_coll_allreduce_description,
mpi_coll_allgatherv_fun = (int (*)(void *, int, MPI_Datatype, void *, int *, int *, MPI_Datatype, MPI_Comm))
mpi_coll_allgatherv_description[allgatherv_id].coll;
int allreduce_id = find_coll_description(mpi_coll_allreduce_description,