Command Parameters of Hyper MPI 26.1.RC1 and Later Versions

-x OMPI_ROMIO_USE_COLL

• Type: int
• Value: 0 or 1

1: Collective communication is enabled in MPI-IO.

0 (default value): Collective communication is disabled.

--mca ompi_group_union_opt

• Type: bool
• Value: true or false

true: The optimized group_union operation is enabled.

false (default value): The optimized group_union operation is disabled.

--mca ompi_group_union_hashsize

• Type: uint
• Value range: 0 to 2³² – 1

Sets the size of the hash table for the optimized group_union operation. The default value is 1024.

-x UCG_USE_SHM_POOL

• Type: bool
• Value: y or n

y: The shared memory pool feature is enabled.

n (default value): The feature is disabled.

--mca coll_tuned_alltoallw_algorithm

• Type: int
• Value: 1 or 2

1: The linear algorithm of alltoallw is used.

2: The pairwise algorithm of alltoallw is used. To enable this parameter, you also need to add --mca coll_tuned_use_dynamic_rules true.

--mca coll_ucg_enable_coll

• Type: string
• Range: collection names. Use commas (,) to separate multiple collection names, for example, allreduce,bcast.
• Default value: none

(Optional) Specifies the collective operations that are enabled after Hyper MPI optimization when a Hyper MPI job is running.

Example:

--mca coll_ucg_enable_coll barrier,bcast