(C) 2010 by Argonne National Laboratory.

    See COPYRIGHT in top-level directory.

Automatically generated

  by:   ./maint/extractcvars

  at:   Wed Nov 13 03:23:43 2019 UTC

DO NOT EDIT!!!

This file lists the various environment variables available to change the

behavior of the MPICH library.  These are intended to be used by advanced

users.

---------------------------------------------------------------------------

MPIR_CVAR_ALLGATHER_SHORT_MSG_SIZE

    Aliases: MPIR_PARAM_ALLGATHER_SHORT_MSG_SIZE

             MPICH_ALLGATHER_SHORT_MSG_SIZE

    Description: For MPI_Allgather and MPI_Allgatherv, the short message

        algorithm will be used if the send buffer size is < this value (in

        bytes). (See also: MPIR_CVAR_ALLGATHER_LONG_MSG_SIZE)

    Default: 81920

MPIR_CVAR_ALLGATHER_LONG_MSG_SIZE

    Aliases: MPIR_PARAM_ALLGATHER_LONG_MSG_SIZE

             MPICH_ALLGATHER_LONG_MSG_SIZE

    Description: For MPI_Allgather and MPI_Allgatherv, the long message

        algorithm will be used if the send buffer size is >= this value (in

        bytes) (See also: MPIR_CVAR_ALLGATHER_SHORT_MSG_SIZE)

    Default: 524288

MPIR_CVAR_ALLGATHER_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_ALLGATHER_INTRA_ALGORITHM

             MPICH_ALLGATHER_INTRA_ALGORITHM

    Description: Variable to select allgather algorithm

        auto               - Internal algorithm selection

        brucks             - Force brucks algorithm

        nb                 - Force nonblocking algorithm

        recursive_doubling - Force recursive doubling algorithm

        ring               - Force ring algorithm

    Default: "auto"

MPIR_CVAR_ALLGATHER_INTER_ALGORITHM

    Aliases: MPIR_PARAM_ALLGATHER_INTER_ALGORITHM

             MPICH_ALLGATHER_INTER_ALGORITHM

    Description: Variable to select allgather algorithm

        auto                      - Internal algorithm selection

        local_gather_remote_bcast - Force local-gather-remote-bcast

        algorithm

        nb                        - Force nonblocking algorithm

    Default: "auto"

MPIR_CVAR_ALLGATHER_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_ALLGATHER_DEVICE_COLLECTIVE

             MPICH_ALLGATHER_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Allgather will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level allgather function will not be called.

    Default: 1

MPIR_CVAR_ALLGATHERV_PIPELINE_MSG_SIZE

    Aliases: MPIR_PARAM_ALLGATHERV_PIPELINE_MSG_SIZE

             MPICH_ALLGATHERV_PIPELINE_MSG_SIZE

    Description: The smallest message size that will be used for the

        pipelined, large-message, ring algorithm in the MPI_Allgatherv

        implementation.

    Default: 32768

MPIR_CVAR_ALLGATHERV_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_ALLGATHERV_INTRA_ALGORITHM

             MPICH_ALLGATHERV_INTRA_ALGORITHM

    Description: Variable to select allgatherv algorithm

        auto               - Internal algorithm selection

        brucks             - Force brucks algorithm

        nb                 - Force nonblocking algorithm

        recursive_doubling - Force recursive doubling algorithm

        ring               - Force ring algorithm

    Default: "auto"

MPIR_CVAR_ALLGATHERV_INTER_ALGORITHM

    Aliases: MPIR_PARAM_ALLGATHERV_INTER_ALGORITHM

             MPICH_ALLGATHERV_INTER_ALGORITHM

    Description: Variable to select allgatherv algorithm

        auto                      - Internal algorithm selection

        nb                        - Force nonblocking algorithm

        remote_gather_local_bcast - Force remote-gather-local-bcast

        algorithm

    Default: "auto"

MPIR_CVAR_ALLGATHERV_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_ALLGATHERV_DEVICE_COLLECTIVE

             MPICH_ALLGATHERV_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Allgatherv will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level allgatherv function will not be called.

    Default: 1

MPIR_CVAR_ALLREDUCE_SHORT_MSG_SIZE

    Aliases: MPIR_PARAM_ALLREDUCE_SHORT_MSG_SIZE

             MPICH_ALLREDUCE_SHORT_MSG_SIZE

    Description: the short message algorithm will be used if the send

        buffer size is <= this value (in bytes)

    Default: 2048

MPIR_CVAR_ENABLE_SMP_COLLECTIVES

    Aliases: MPIR_PARAM_ENABLE_SMP_COLLECTIVES

             MPICH_ENABLE_SMP_COLLECTIVES

    Description: Enable SMP aware collective communication.

    Default: 1

MPIR_CVAR_ENABLE_SMP_ALLREDUCE

    Aliases: MPIR_PARAM_ENABLE_SMP_ALLREDUCE

             MPICH_ENABLE_SMP_ALLREDUCE

    Description: Enable SMP aware allreduce.

    Default: 1

MPIR_CVAR_MAX_SMP_ALLREDUCE_MSG_SIZE

    Aliases: MPIR_PARAM_MAX_SMP_ALLREDUCE_MSG_SIZE

             MPICH_MAX_SMP_ALLREDUCE_MSG_SIZE

    Description: Maximum message size for which SMP-aware allreduce is

        used.  A value of '0' uses SMP-aware allreduce for all message

        sizes.

    Default: 0

MPIR_CVAR_ALLREDUCE_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_ALLREDUCE_INTRA_ALGORITHM

             MPICH_ALLREDUCE_INTRA_ALGORITHM

    Description: Variable to select allreduce algorithm

        auto                     - Internal algorithm selection

        nb                       - Force nonblocking algorithm

        recursive_doubling       - Force recursive doubling algorithm

        reduce_scatter_allgather - Force reduce scatter allgather algorithm

    Default: "auto"

MPIR_CVAR_ALLREDUCE_INTER_ALGORITHM

    Aliases: MPIR_PARAM_ALLREDUCE_INTER_ALGORITHM

             MPICH_ALLREDUCE_INTER_ALGORITHM

    Description: Variable to select allreduce algorithm

        auto                  - Internal algorithm selection

        nb                    - Force nonblocking algorithm

        reduce_exchange_bcast - Force reduce-exchange-bcast algorithm

    Default: "auto"

MPIR_CVAR_ALLREDUCE_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_ALLREDUCE_DEVICE_COLLECTIVE

             MPICH_ALLREDUCE_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Allreduce will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level allreduce function will not be called.

    Default: 1

MPIR_CVAR_ALLTOALL_SHORT_MSG_SIZE

    Aliases: MPIR_PARAM_ALLTOALL_SHORT_MSG_SIZE

             MPICH_ALLTOALL_SHORT_MSG_SIZE

    Description: the short message algorithm will be used if the

        per-destination message size (sendcount*size(sendtype)) is <= this

        value (See also: MPIR_CVAR_ALLTOALL_MEDIUM_MSG_SIZE)

    Default: 256

MPIR_CVAR_ALLTOALL_MEDIUM_MSG_SIZE

    Aliases: MPIR_PARAM_ALLTOALL_MEDIUM_MSG_SIZE

             MPICH_ALLTOALL_MEDIUM_MSG_SIZE

    Description: the medium message algorithm will be used if the

        per-destination message size (sendcount*size(sendtype)) is <= this

        value and larger than MPIR_CVAR_ALLTOALL_SHORT_MSG_SIZE (See also:

        MPIR_CVAR_ALLTOALL_SHORT_MSG_SIZE)

    Default: 32768

MPIR_CVAR_ALLTOALL_THROTTLE

    Aliases: MPIR_PARAM_ALLTOALL_THROTTLE

             MPICH_ALLTOALL_THROTTLE

    Description: max no. of irecvs/isends posted at a time in some alltoall

        algorithms. Setting it to 0 causes all irecvs/isends to be posted

        at once

    Default: 32

MPIR_CVAR_ALLTOALL_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_ALLTOALL_INTRA_ALGORITHM

             MPICH_ALLTOALL_INTRA_ALGORITHM

    Description: Variable to select alltoall algorithm

        auto                      - Internal algorithm selection

        brucks                    - Force brucks algorithm

        nb                        - Force nonblocking algorithm

        pairwise                  - Force pairwise algorithm

        pairwise_sendrecv_replace - Force pairwise sendrecv replace

        algorithm

        scattered                 - Force scattered algorithm

    Default: "auto"

MPIR_CVAR_ALLTOALL_INTER_ALGORITHM

    Aliases: MPIR_PARAM_ALLTOALL_INTER_ALGORITHM

             MPICH_ALLTOALL_INTER_ALGORITHM

    Description: Variable to select alltoall algorithm

        auto              - Internal algorithm selection

        nb                - Force nonblocking algorithm

        pairwise_exchange - Force pairwise exchange algorithm

    Default: "auto"

MPIR_CVAR_ALLTOALL_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_ALLTOALL_DEVICE_COLLECTIVE

             MPICH_ALLTOALL_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Alltoall will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level alltoall function will not be called.

    Default: 1

MPIR_CVAR_ALLTOALLV_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_ALLTOALLV_INTRA_ALGORITHM

             MPICH_ALLTOALLV_INTRA_ALGORITHM

    Description: Variable to select alltoallv algorithm

        auto                      - Internal algorithm selection

        nb                        - Force nonblocking algorithm

        pairwise_sendrecv_replace - Force pairwise_sendrecv_replace

        algorithm

        scattered                 - Force scattered algorithm

    Default: "auto"

MPIR_CVAR_ALLTOALLV_INTER_ALGORITHM

    Aliases: MPIR_PARAM_ALLTOALLV_INTER_ALGORITHM

             MPICH_ALLTOALLV_INTER_ALGORITHM

    Description: Variable to select alltoallv algorithm

        auto              - Internal algorithm selection

        pairwise_exchange - Force pairwise exchange algorithm

        nb                - Force nonblocking algorithm

    Default: "auto"

MPIR_CVAR_ALLTOALLV_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_ALLTOALLV_DEVICE_COLLECTIVE

             MPICH_ALLTOALLV_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Alltoallv will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level alltoallv function will not be called.

    Default: 1

MPIR_CVAR_ALLTOALLW_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_ALLTOALLW_INTRA_ALGORITHM

             MPICH_ALLTOALLW_INTRA_ALGORITHM

    Description: Variable to select alltoallw algorithm

        auto                      - Internal algorithm selection

        nb                        - Force nonblocking algorithm

        pairwise_sendrecv_replace - Force pairwise sendrecv replace

        algorithm

        scattered                 - Force scattered algorithm

    Default: "auto"

MPIR_CVAR_ALLTOALLW_INTER_ALGORITHM

    Aliases: MPIR_PARAM_ALLTOALLW_INTER_ALGORITHM

             MPICH_ALLTOALLW_INTER_ALGORITHM

    Description: Variable to select alltoallw algorithm

        auto              - Internal algorithm selection

        nb                - Force nonblocking algorithm

        pairwise_exchange - Force pairwise exchange algorithm

    Default: "auto"

MPIR_CVAR_ALLTOALLW_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_ALLTOALLW_DEVICE_COLLECTIVE

             MPICH_ALLTOALLW_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Alltoallw will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level alltoallw function will not be called.

    Default: 1

MPIR_CVAR_ENABLE_SMP_BARRIER

    Aliases: MPIR_PARAM_ENABLE_SMP_BARRIER

             MPICH_ENABLE_SMP_BARRIER

    Description: Enable SMP aware barrier.

    Default: 1

MPIR_CVAR_BARRIER_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_BARRIER_INTRA_ALGORITHM

             MPICH_BARRIER_INTRA_ALGORITHM

    Description: Variable to select barrier algorithm

        auto               - Internal algorithm selection

        nb                 - Force nonblocking algorithm

        recursive_doubling - Force recursive doubling algorithm

    Default: "auto"

MPIR_CVAR_BARRIER_INTER_ALGORITHM

    Aliases: MPIR_PARAM_BARRIER_INTER_ALGORITHM

             MPICH_BARRIER_INTER_ALGORITHM

    Description: Variable to select barrier algorithm

        auto  - Internal algorithm selection

        bcast - Force bcast algorithm

        nb    - Force nonblocking algorithm

    Default: "auto"

MPIR_CVAR_BARRIER_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_BARRIER_DEVICE_COLLECTIVE

             MPICH_BARRIER_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Barrier will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level barrier function will not be called.

    Default: 1

MPIR_CVAR_BCAST_MIN_PROCS

    Aliases: MPIR_PARAM_BCAST_MIN_PROCS

             MPICH_BCAST_MIN_PROCS

    Description: Let's define short messages as messages with size <

        MPIR_CVAR_BCAST_SHORT_MSG_SIZE, and medium messages as messages

        with size >= MPIR_CVAR_BCAST_SHORT_MSG_SIZE but <

        MPIR_CVAR_BCAST_LONG_MSG_SIZE, and long messages as messages with

        size >= MPIR_CVAR_BCAST_LONG_MSG_SIZE. The broadcast algorithms

        selection procedure is as follows. For short messages or when the

        number of processes is < MPIR_CVAR_BCAST_MIN_PROCS, we do broadcast

        using the binomial tree algorithm. Otherwise, for medium messages

        and with a power-of-two number of processes, we do broadcast based

        on a scatter followed by a recursive doubling allgather algorithm.

        Otherwise, for long messages or with non power-of-two number of

        processes, we do broadcast based on a scatter followed by a ring

        allgather algorithm. (See also: MPIR_CVAR_BCAST_SHORT_MSG_SIZE,

        MPIR_CVAR_BCAST_LONG_MSG_SIZE)

    Default: 8

MPIR_CVAR_BCAST_SHORT_MSG_SIZE

    Aliases: MPIR_PARAM_BCAST_SHORT_MSG_SIZE

             MPICH_BCAST_SHORT_MSG_SIZE

    Description: Let's define short messages as messages with size <

        MPIR_CVAR_BCAST_SHORT_MSG_SIZE, and medium messages as messages

        with size >= MPIR_CVAR_BCAST_SHORT_MSG_SIZE but <

        MPIR_CVAR_BCAST_LONG_MSG_SIZE, and long messages as messages with

        size >= MPIR_CVAR_BCAST_LONG_MSG_SIZE. The broadcast algorithms

        selection procedure is as follows. For short messages or when the

        number of processes is < MPIR_CVAR_BCAST_MIN_PROCS, we do broadcast

        using the binomial tree algorithm. Otherwise, for medium messages

        and with a power-of-two number of processes, we do broadcast based

        on a scatter followed by a recursive doubling allgather algorithm.

        Otherwise, for long messages or with non power-of-two number of

        processes, we do broadcast based on a scatter followed by a ring

        allgather algorithm. (See also: MPIR_CVAR_BCAST_MIN_PROCS,

        MPIR_CVAR_BCAST_LONG_MSG_SIZE)

    Default: 12288

MPIR_CVAR_BCAST_LONG_MSG_SIZE

    Aliases: MPIR_PARAM_BCAST_LONG_MSG_SIZE

             MPICH_BCAST_LONG_MSG_SIZE

    Description: Let's define short messages as messages with size <

        MPIR_CVAR_BCAST_SHORT_MSG_SIZE, and medium messages as messages

        with size >= MPIR_CVAR_BCAST_SHORT_MSG_SIZE but <

        MPIR_CVAR_BCAST_LONG_MSG_SIZE, and long messages as messages with

        size >= MPIR_CVAR_BCAST_LONG_MSG_SIZE. The broadcast algorithms

        selection procedure is as follows. For short messages or when the

        number of processes is < MPIR_CVAR_BCAST_MIN_PROCS, we do broadcast

        using the binomial tree algorithm. Otherwise, for medium messages

        and with a power-of-two number of processes, we do broadcast based

        on a scatter followed by a recursive doubling allgather algorithm.

        Otherwise, for long messages or with non power-of-two number of

        processes, we do broadcast based on a scatter followed by a ring

        allgather algorithm. (See also: MPIR_CVAR_BCAST_MIN_PROCS,

        MPIR_CVAR_BCAST_SHORT_MSG_SIZE)

    Default: 524288

MPIR_CVAR_ENABLE_SMP_BCAST

    Aliases: MPIR_PARAM_ENABLE_SMP_BCAST

             MPICH_ENABLE_SMP_BCAST

    Description: Enable SMP aware broadcast (See also:

        MPIR_CVAR_MAX_SMP_BCAST_MSG_SIZE)

    Default: 1

MPIR_CVAR_MAX_SMP_BCAST_MSG_SIZE

    Aliases: MPIR_PARAM_MAX_SMP_BCAST_MSG_SIZE

             MPICH_MAX_SMP_BCAST_MSG_SIZE

    Description: Maximum message size for which SMP-aware broadcast is

        used.  A value of '0' uses SMP-aware broadcast for all message

        sizes. (See also: MPIR_CVAR_ENABLE_SMP_BCAST)

    Default: 0

MPIR_CVAR_BCAST_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_BCAST_INTRA_ALGORITHM

             MPICH_BCAST_INTRA_ALGORITHM

    Description: Variable to select bcast algorithm

        auto                                    - Internal algorithm

        selection

        binomial                                - Force Binomial Tree

        nb                                      - Force nonblocking

        algorithm

        scatter_recursive_doubling_allgather    - Force Scatter

        Recursive-Doubling Allgather

        scatter_ring_allgather                  - Force Scatter Ring

    Default: "auto"

MPIR_CVAR_BCAST_INTER_ALGORITHM

    Aliases: MPIR_PARAM_BCAST_INTER_ALGORITHM

             MPICH_BCAST_INTER_ALGORITHM

    Description: Variable to select bcast algorithm

        auto                    - Internal algorithm selection

        nb                      - Force nonblocking algorithm

        remote_send_local_bcast - Force remote-send-local-bcast algorithm

    Default: "auto"

MPIR_CVAR_BCAST_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_BCAST_DEVICE_COLLECTIVE

             MPICH_BCAST_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Bcast will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually.  If set to

        false, the device-level bcast function will not be called.

    Default: 1

MPIR_CVAR_EXSCAN_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_EXSCAN_INTRA_ALGORITHM

             MPICH_EXSCAN_INTRA_ALGORITHM

    Description: Variable to select allgather algorithm

        auto               - Internal algorithm selection

        nb                 - Force nonblocking algorithm

        recursive_doubling - Force recursive doubling algorithm

    Default: "auto"

MPIR_CVAR_EXSCAN_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_EXSCAN_DEVICE_COLLECTIVE

             MPICH_EXSCAN_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Exscan will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level exscan function will not be called.

    Default: 1

MPIR_CVAR_GATHER_INTER_SHORT_MSG_SIZE

    Aliases: MPIR_PARAM_GATHER_INTER_SHORT_MSG_SIZE

             MPICH_GATHER_INTER_SHORT_MSG_SIZE

    Description: use the short message algorithm for intercommunicator

        MPI_Gather if the send buffer size is < this value (in bytes) (See

        also: MPIR_CVAR_GATHER_VSMALL_MSG_SIZE)

    Default: 2048

MPIR_CVAR_GATHER_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_GATHER_INTRA_ALGORITHM

             MPICH_GATHER_INTRA_ALGORITHM

    Description: Variable to select gather algorithm

        auto     - Internal algorithm selection

        binomial - Force binomial algorithm

        nb       - Force nonblocking algorithm

    Default: "auto"

MPIR_CVAR_GATHER_INTER_ALGORITHM

    Aliases: MPIR_PARAM_GATHER_INTER_ALGORITHM

             MPICH_GATHER_INTER_ALGORITHM

    Description: Variable to select gather algorithm

        auto                     - Internal algorithm selection

        linear                   - Force linear algorithm

        local_gather_remote_send - Force local-gather-remote-send algorithm

        nb                       - Force nonblocking algorithm

    Default: "auto"

MPIR_CVAR_GATHER_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_GATHER_DEVICE_COLLECTIVE

             MPICH_GATHER_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Gather will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level gather function will not be called.

    Default: 1

MPIR_CVAR_GATHER_VSMALL_MSG_SIZE

    Aliases: MPIR_PARAM_GATHER_VSMALL_MSG_SIZE

             MPICH_GATHER_VSMALL_MSG_SIZE

    Description: use a temporary buffer for intracommunicator MPI_Gather if

        the send buffer size is < this value (in bytes) (See also:

        MPIR_CVAR_GATHER_INTER_SHORT_MSG_SIZE)

    Default: 1024

MPIR_CVAR_GATHERV_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_GATHERV_INTRA_ALGORITHM

             MPICH_GATHERV_INTRA_ALGORITHM

    Description: Variable to select gatherv algorithm

        auto   - Internal algorithm selection

        linear - Force linear algorithm

        nb     - Force nonblocking algorithm

    Default: "auto"

MPIR_CVAR_GATHERV_INTER_ALGORITHM

    Aliases: MPIR_PARAM_GATHERV_INTER_ALGORITHM

             MPICH_GATHERV_INTER_ALGORITHM

    Description: Variable to select gatherv algorithm

        auto   - Internal algorithm selection

        linear - Force linear algorithm

        nb     - Force nonblocking algorithm

    Default: "auto"

MPIR_CVAR_GATHERV_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_GATHERV_DEVICE_COLLECTIVE

             MPICH_GATHERV_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Gatherv will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level gatherv function will not be called.

    Default: 1

MPIR_CVAR_GATHERV_INTER_SSEND_MIN_PROCS

    Aliases: MPIR_PARAM_GATHERV_INTER_SSEND_MIN_PROCS

             MPICH_GATHERV_INTER_SSEND_MIN_PROCS

    Description: Use Ssend (synchronous send) for intercommunicator

        MPI_Gatherv if the "group B" size is >= this value.  Specifying

        "-1" always avoids using Ssend.  For backwards compatibility,

        specifying "0" uses the default value.

    Default: 32

MPIR_CVAR_IALLGATHER_RECEXCH_KVAL

    Aliases: MPIR_PARAM_IALLGATHER_RECEXCH_KVAL

             MPICH_IALLGATHER_RECEXCH_KVAL

    Description: k value for recursive exchange based iallgather

    Default: 2

MPIR_CVAR_IALLGATHER_BRUCKS_KVAL

    Aliases: MPIR_PARAM_IALLGATHER_BRUCKS_KVAL

             MPICH_IALLGATHER_BRUCKS_KVAL

    Description: k value for radix in brucks based iallgather

    Default: 2

MPIR_CVAR_IALLGATHER_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_IALLGATHER_INTRA_ALGORITHM

             MPICH_IALLGATHER_INTRA_ALGORITHM

    Description: Variable to select iallgather algorithm

        auto               - Internal algorithm selection

        brucks             - Force brucks algorithm

        recursive_doubling - Force recursive doubling algorithm

        ring               - Force ring algorithm

        recexch_distance_doubling    - Force generic transport recursive

        exchange with neighbours doubling in distance in each phase

        recexch_distance_halving  - Force generic transport recursive

        exchange with neighbours halving in distance in each phase

        gentran_brucks     - Force generic transport based brucks algorithm

    Default: "auto"

MPIR_CVAR_IALLGATHER_INTER_ALGORITHM

    Aliases: MPIR_PARAM_IALLGATHER_INTER_ALGORITHM

             MPICH_IALLGATHER_INTER_ALGORITHM

    Description: Variable to select iallgather algorithm

        auto                      - Internal algorithm selection

        local_gather_remote_bcast - Force local-gather-remote-bcast

        algorithm

    Default: "auto"

MPIR_CVAR_IALLGATHER_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_IALLGATHER_DEVICE_COLLECTIVE

             MPICH_IALLGATHER_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Iallgather will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level iallgather function will not be called.

    Default: 1

MPIR_CVAR_IALLGATHERV_RECEXCH_KVAL

    Aliases: MPIR_PARAM_IALLGATHERV_RECEXCH_KVAL

             MPICH_IALLGATHERV_RECEXCH_KVAL

    Description: k value for recursive exchange based iallgatherv

    Default: 2

MPIR_CVAR_IALLGATHERV_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_IALLGATHERV_INTRA_ALGORITHM

             MPICH_IALLGATHERV_INTRA_ALGORITHM

    Description: Variable to select iallgatherv algorithm

        auto               - Internal algorithm selection

        brucks             - Force brucks algorithm

        recursive_doubling - Force recursive doubling algorithm

        ring               - Force ring algorithm

        recexch_distance_doubling    - Force generic transport recursive

        exchange with neighbours doubling in distance in each phase

        recexch_distance_halving     - Force generic transport recursive

        exchange with neighbours halving in distance in each phase

        gentran_ring              - Force generic transport ring algorithm

    Default: "auto"

MPIR_CVAR_IALLGATHERV_INTER_ALGORITHM

    Aliases: MPIR_PARAM_IALLGATHERV_INTER_ALGORITHM

             MPICH_IALLGATHERV_INTER_ALGORITHM

    Description: Variable to select iallgatherv algorithm

        auto                      - Internal algorithm selection

        remote_gather_local_bcast - Force remote-gather-local-bcast

        algorithm

    Default: "auto"

MPIR_CVAR_IALLGATHERV_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_IALLGATHERV_DEVICE_COLLECTIVE

             MPICH_IALLGATHERV_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Iallgatherv will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level iallgatherv function will not be called.

    Default: 1

MPIR_CVAR_IALLREDUCE_TREE_KVAL

    Aliases: MPIR_PARAM_IALLREDUCE_TREE_KVAL

             MPICH_IALLREDUCE_TREE_KVAL

    Description: k value for tree based iallreduce (for tree_kary and

        tree_knomial)

    Default: 2

MPIR_CVAR_IALLREDUCE_TREE_PIPELINE_CHUNK_SIZE

    Aliases: MPIR_PARAM_IALLREDUCE_TREE_PIPELINE_CHUNK_SIZE

             MPICH_IALLREDUCE_TREE_PIPELINE_CHUNK_SIZE

    Description: Maximum chunk size (in bytes) for pipelining in tree based

        iallreduce (tree_kary and tree_knomial). Default value is 0, that

        is, no pipelining by default

    Default: -1

MPIR_CVAR_IALLREDUCE_TREE_BUFFER_PER_CHILD

    Aliases: MPIR_PARAM_IALLREDUCE_TREE_BUFFER_PER_CHILD

             MPICH_IALLREDUCE_TREE_BUFFER_PER_CHILD

    Description: If set to true, a rank in tree_kary and tree_knomial

        algorithms will allocate a dedicated buffer for every child it

        receives data from. This would mean more memory consumption but it

        would allow preposting of the receives and hence reduce the number

        of unexpected messages. If set to false, there is only one buffer

        that is used to receive the data from all the children. The

        receives are therefore serialized, that is, only one receive can be

        posted at a time.

    Default: 0

MPIR_CVAR_IALLREDUCE_RECEXCH_KVAL

    Aliases: MPIR_PARAM_IALLREDUCE_RECEXCH_KVAL

             MPICH_IALLREDUCE_RECEXCH_KVAL

    Description: k value for recursive exchange based iallreduce

    Default: 2

MPIR_CVAR_IALLREDUCE_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_IALLREDUCE_INTRA_ALGORITHM

             MPICH_IALLREDUCE_INTRA_ALGORITHM

    Description: Variable to select iallreduce algorithm

        auto                     - Internal algorithm selection

        naive                    - Force naive algorithm

        recursive_doubling       - Force recursive doubling algorithm

        reduce_scatter_allgather - Force reduce scatter allgather algorithm

        recexch_single_buffer    - Force generic transport recursive

        exchange with single buffer for receives

        recexch_multiple_buffer  - Force generic transport recursive

        exchange with multiple buffers for receives

    Default: "auto"

MPIR_CVAR_IALLREDUCE_INTER_ALGORITHM

    Aliases: MPIR_PARAM_IALLREDUCE_INTER_ALGORITHM

             MPICH_IALLREDUCE_INTER_ALGORITHM

    Description: Variable to select iallreduce algorithm

        auto                      - Internal algorithm selection

        remote_reduce_local_bcast - Force remote-reduce-local-bcast

        algorithm

    Default: "auto"

MPIR_CVAR_IALLREDUCE_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_IALLREDUCE_DEVICE_COLLECTIVE

             MPICH_IALLREDUCE_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Iallreduce will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level iallreduce function will not be called.

    Default: 1

MPIR_CVAR_IALLTOALL_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_IALLTOALL_INTRA_ALGORITHM

             MPICH_IALLTOALL_INTRA_ALGORITHM

    Description: Variable to select ialltoall algorithm

        auto              - Internal algorithm selection

        brucks            - Force brucks algorithm

        inplace           - Force inplace algorithm

        pairwise          - Force pairwise algorithm

        permuted_sendrecv - Force permuted sendrecv algorithm

    Default: "auto"

MPIR_CVAR_IALLTOALL_INTER_ALGORITHM

    Aliases: MPIR_PARAM_IALLTOALL_INTER_ALGORITHM

             MPICH_IALLTOALL_INTER_ALGORITHM

    Description: Variable to select ialltoall algorithm

        auto              - Internal algorithm selection

        pairwise_exchange - Force pairwise exchange algorithm

    Default: "auto"

MPIR_CVAR_IALLTOALL_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_IALLTOALL_DEVICE_COLLECTIVE

             MPICH_IALLTOALL_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Ialltoall will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level ialltoall function will not be called.

    Default: 1

MPIR_CVAR_IALLTOALLV_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_IALLTOALLV_INTRA_ALGORITHM

             MPICH_IALLTOALLV_INTRA_ALGORITHM

    Description: Variable to select ialltoallv algorithm

        auto              - Internal algorithm selection

        blocked           - Force blocked algorithm

        inplace           - Force inplace algorithm

        pairwise_exchange - Force pairwise exchange algorithm

    Default: "auto"

MPIR_CVAR_IALLTOALLV_INTER_ALGORITHM

    Aliases: MPIR_PARAM_IALLTOALLV_INTER_ALGORITHM

             MPICH_IALLTOALLV_INTER_ALGORITHM

    Description: Variable to select ialltoallv algorithm

        auto - Internal algorithm selection

    Default: "auto"

MPIR_CVAR_IALLTOALLV_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_IALLTOALLV_DEVICE_COLLECTIVE

             MPICH_IALLTOALLV_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Ialltoallv will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level ialltoallv function will not be called.

    Default: 1

MPIR_CVAR_IALLTOALLW_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_IALLTOALLW_INTRA_ALGORITHM

             MPICH_IALLTOALLW_INTRA_ALGORITHM

    Description: Variable to select ialltoallw algorithm

        auto              - Internal algorithm selection

        blocked           - Force blocked algorithm

        inplace           - Force inplace algorithm

        pairwise_exchange - Force pairwise exchange algorithm

    Default: "auto"

MPIR_CVAR_IALLTOALLW_INTER_ALGORITHM

    Aliases: MPIR_PARAM_IALLTOALLW_INTER_ALGORITHM

             MPICH_IALLTOALLW_INTER_ALGORITHM

    Description: Variable to select ialltoallw algorithm

        auto - Internal algorithm selection

    Default: "auto"

MPIR_CVAR_IALLTOALLW_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_IALLTOALLW_DEVICE_COLLECTIVE

             MPICH_IALLTOALLW_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Ialltoallw will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level ialltoallw function will not be called.

    Default: 1

MPIR_CVAR_IBARRIER_RECEXCH_KVAL

    Aliases: MPIR_PARAM_IBARRIER_RECEXCH_KVAL

             MPICH_IBARRIER_RECEXCH_KVAL

    Description: k value for recursive exchange based ibarrier

    Default: 2

MPIR_CVAR_IBARRIER_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_IBARRIER_INTRA_ALGORITHM

             MPICH_IBARRIER_INTRA_ALGORITHM

    Description: Variable to select ibarrier algorithm

        auto               - Internal algorithm selection

        recursive_doubling - Force recursive doubling algorithm

        recexch            - Force generic transport based recursive

        exchange algorithm

    Default: "auto"

MPIR_CVAR_IBARRIER_INTER_ALGORITHM

    Aliases: MPIR_PARAM_IBARRIER_INTER_ALGORITHM

             MPICH_IBARRIER_INTER_ALGORITHM

    Description: Variable to select ibarrier algorithm

        auto  - Internal algorithm selection

        bcast - Force bcast algorithm

    Default: "auto"

MPIR_CVAR_IBARRIER_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_IBARRIER_DEVICE_COLLECTIVE

             MPICH_IBARRIER_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Ibarrier will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level ibarrier function will not be called.

    Default: 1

MPIR_CVAR_IBCAST_TREE_KVAL

    Aliases: MPIR_PARAM_IBCAST_TREE_KVAL

             MPICH_IBCAST_TREE_KVAL

    Description: k value for tree (kary, knomial, etc.) based ibcast

    Default: 2

MPIR_CVAR_IBCAST_TREE_TYPE

    Aliases: MPIR_PARAM_IBCAST_TREE_TYPE

             MPICH_IBCAST_TREE_TYPE

    Description: Tree type for tree based ibcast kary      - kary tree type

        knomial_1 - knomial_1 tree type knomial_2 - knomial_2 tree type

    Default: "kary"

MPIR_CVAR_IBCAST_TREE_PIPELINE_CHUNK_SIZE

    Aliases: MPIR_PARAM_IBCAST_TREE_PIPELINE_CHUNK_SIZE

             MPICH_IBCAST_TREE_PIPELINE_CHUNK_SIZE

    Description: Maximum chunk size (in bytes) for pipelining in tree based

        ibcast. Default value is 0, that is, no pipelining by default

    Default: 0

MPIR_CVAR_IBCAST_RING_CHUNK_SIZE

    Aliases: MPIR_PARAM_IBCAST_RING_CHUNK_SIZE

             MPICH_IBCAST_RING_CHUNK_SIZE

    Description: Maximum chunk size (in bytes) for pipelining in ibcast

        ring algorithm. Default value is 0, that is, no pipelining by

        default

    Default: 0

MPIR_CVAR_IBCAST_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_IBCAST_INTRA_ALGORITHM

             MPICH_IBCAST_INTRA_ALGORITHM

    Description: Variable to select ibcast algorithm

        auto                                 - Internal algorithm selection

        binomial                             - Force Binomial algorithm

        scatter_recursive_doubling_allgather - Force Scatter Recursive

        Doubling Allgather algorithm

        scatter_ring_allgather               - Force Scatter Ring Allgather

        algorithm

        tree                                 - Force Generic Transport Tree

        algorithm

        scatter_recexch_allgather            - Force Generic Transport

        Scatter followed by Recursive Exchange Allgather algorithm

        ring                                 - Force Generic Transport Ring

        algorithm

    Default: "auto"

MPIR_CVAR_IBCAST_SCATTER_KVAL

    Aliases: MPIR_PARAM_IBCAST_SCATTER_KVAL

             MPICH_IBCAST_SCATTER_KVAL

    Description: k value for tree based scatter in

        scatter_recexch_allgather algorithm

    Default: 2

MPIR_CVAR_IBCAST_ALLGATHER_RECEXCH_KVAL

    Aliases: MPIR_PARAM_IBCAST_ALLGATHER_RECEXCH_KVAL

             MPICH_IBCAST_ALLGATHER_RECEXCH_KVAL

    Description: k value for recursive exchange based allgather in

        scatter_recexch_allgather algorithm

    Default: 2

MPIR_CVAR_IBCAST_INTER_ALGORITHM

    Aliases: MPIR_PARAM_IBCAST_INTER_ALGORITHM

             MPICH_IBCAST_INTER_ALGORITHM

    Description: Variable to select ibcast algorithm

        auto - Internal algorithm selection

        flat - Force flat algorithm

    Default: "auto"

MPIR_CVAR_IBCAST_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_IBCAST_DEVICE_COLLECTIVE

             MPICH_IBCAST_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Ibcast will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually.  If set to

        false, the device-level ibcast function will not be called.

    Default: 1

MPIR_CVAR_IEXSCAN_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_IEXSCAN_INTRA_ALGORITHM

             MPICH_IEXSCAN_INTRA_ALGORITHM

    Description: Variable to select iexscan algorithm

        auto               - Internal algorithm selection

        recursive_doubling - Force recursive doubling algorithm

    Default: "auto"

MPIR_CVAR_IEXSCAN_DEVICE_COLLECTIVE

    Aliases: MPIR_PARAM_IEXSCAN_DEVICE_COLLECTIVE

             MPICH_IEXSCAN_DEVICE_COLLECTIVE

    Description: If set to true, MPI_Iexscan will allow the device to

        override the MPIR-level collective algorithms. The device still has

        the option to call the MPIR-level algorithms manually. If set to

        false, the device-level iexscan function will not be called.

    Default: 1

MPIR_CVAR_IGATHER_INTRA_ALGORITHM

    Aliases: MPIR_PARAM_IGATHER_INTRA_ALGORITHM

             MPICH_IGATHER_INTRA_ALGORITHM

    Description: Variable to select igather algorithm

        auto     - Internal algorithm selection

        binomial - Force binomial algorithm

        tree     - Force genetric transport based tree algorithm

    Default: "auto"

MPIR_CVAR_IGATHER_TREE_KVAL

    Aliases: MPIR_PARAM_IGATHER_TREE_KVAL

             MPICH_IGATHER_TREE_KVAL

    Description: k value for tree based igather

    Default: 2

MPIR_CVAR_IGATHER_INTER_ALGORITHM

    Aliases: MPIR_PARAM_IGATHER_INTER_ALGORITHM

             MPICH_IGATHER_INTER_ALGORITHM

    Description: Variable to select igather algorithm

        auto        - Internal algorithm selection

        long_inter  - Force long inter algorithm

        short_inter - Force short inter algorithm