README.envvar
Copyright (C) by Argonne National Laboratory
See COPYRIGHT in top-level directory
Automatically generated
by: ./maint/extractcvars
at: Mon Feb 3 15:10:00 2025 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.
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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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
smp - Force smp algorithm
k_dissemination - Force high radix dissemination algorithm
recexch - Force recursive exchange algorithm
Default: MPIR_CVAR_BARRIER_INTRA_ALGORITHM_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
bcast - Force bcast algorithm
nb - Force nonblocking algorithm
Default: MPIR_CVAR_BARRIER_INTER_ALGORITHM_auto
MPIR_CVAR_BARRIER_DISSEM_KVAL
Aliases: MPIR_PARAM_BARRIER_DISSEM_KVAL
MPICH_BARRIER_DISSEM_KVAL
Description: k value for dissemination exchange based barrier algorithm
Default: 2
MPIR_CVAR_BARRIER_RECEXCH_KVAL
Aliases: MPIR_PARAM_BARRIER_RECEXCH_KVAL
MPICH_BARRIER_RECEXCH_KVAL
Description: k value for recursive exchange based allreduce based
barrier
Default: 2
MPIR_CVAR_BARRIER_RECEXCH_SINGLE_PHASE_RECV
Aliases: MPIR_PARAM_BARRIER_RECEXCH_SINGLE_PHASE_RECV
MPICH_BARRIER_RECEXCH_SINGLE_PHASE_RECV
Description: This CVAR controls whether the recv is posted for one
phase or two phases in recexch algos. By default, we post the recvs
for 2 phases.
Default: 0
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_DISSEM_KVAL
Aliases: MPIR_PARAM_IBARRIER_DISSEM_KVAL
MPICH_IBARRIER_DISSEM_KVAL
Description: k value for dissemination 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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_recursive_doubling - Force recursive doubling algorithm
tsp_recexch - Force generic transport based recursive exchange
algorithm
tsp_k_dissemination - Force generic transport based high-radix
dissemination algorithm
Default: MPIR_CVAR_IBARRIER_INTRA_ALGORITHM_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_bcast - Force bcast algorithm
Default: MPIR_CVAR_IBARRIER_INTER_ALGORITHM_auto
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_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.
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
binomial - Force Binomial Tree
nb - Force nonblocking
algorithm
smp - Force smp algorithm
scatter_recursive_doubling_allgather - Force Scatter
Recursive-Doubling Allgather
scatter_ring_allgather - Force Scatter Ring
pipelined_tree - Force tree-based
pipelined algorithm
tree - Force tree-based
algorithm
Default: MPIR_CVAR_BCAST_INTRA_ALGORITHM_auto
MPIR_CVAR_BCAST_TREE_KVAL
Aliases: MPIR_PARAM_BCAST_TREE_KVAL
MPICH_BCAST_TREE_KVAL
Description: k value for tree (kary, knomial, etc.) based bcast
Default: 2
MPIR_CVAR_BCAST_TREE_TYPE
Aliases: MPIR_PARAM_BCAST_TREE_TYPE
MPICH_BCAST_TREE_TYPE
Description: Tree type for tree based bcast kary - kary tree type
knomial_1 - knomial_1 tree type knomial_2 - knomial_2 tree type
topology_aware - topology_aware tree type topology_aware_k -
topology_aware tree type with branching factor k topology_wave -
topology_wave tree type
Default: "kary"
MPIR_CVAR_BCAST_TOPO_REORDER_ENABLE
Aliases: MPIR_PARAM_BCAST_TOPO_REORDER_ENABLE
MPICH_BCAST_TOPO_REORDER_ENABLE
Description: This cvar controls if the leaders are reordered based on
the number of ranks in each group.
Default: 1
MPIR_CVAR_BCAST_TOPO_OVERHEAD
Aliases: MPIR_PARAM_BCAST_TOPO_OVERHEAD
MPICH_BCAST_TOPO_OVERHEAD
Description: This cvar controls the size of the overhead.
Default: 200
MPIR_CVAR_BCAST_TOPO_DIFF_GROUPS
Aliases: MPIR_PARAM_BCAST_TOPO_DIFF_GROUPS
MPICH_BCAST_TOPO_DIFF_GROUPS
Description: This cvar controls the latency between different groups.
Default: 2800
MPIR_CVAR_BCAST_TOPO_DIFF_SWITCHES
Aliases: MPIR_PARAM_BCAST_TOPO_DIFF_SWITCHES
MPICH_BCAST_TOPO_DIFF_SWITCHES
Description: This cvar controls the latency between different switches
in the same groups.
Default: 1900
MPIR_CVAR_BCAST_TOPO_SAME_SWITCHES
Aliases: MPIR_PARAM_BCAST_TOPO_SAME_SWITCHES
MPICH_BCAST_TOPO_SAME_SWITCHES
Description: This cvar controls the latency in the same switch.
Default: 1600
MPIR_CVAR_BCAST_IS_NON_BLOCKING
Aliases: MPIR_PARAM_BCAST_IS_NON_BLOCKING
MPICH_BCAST_IS_NON_BLOCKING
Description: If set to true, MPI_Bcast will use non-blocking send.
Default: 1
MPIR_CVAR_BCAST_TREE_PIPELINE_CHUNK_SIZE
Aliases: MPIR_PARAM_BCAST_TREE_PIPELINE_CHUNK_SIZE
MPICH_BCAST_TREE_PIPELINE_CHUNK_SIZE
Description: Indicates the chunk size for pipelined bcast.
Default: 8192
MPIR_CVAR_BCAST_RECV_PRE_POST
Aliases: MPIR_PARAM_BCAST_RECV_PRE_POST
MPICH_BCAST_RECV_PRE_POST
Description: If set to true, MPI_Bcast will pre-post all the receives.
Default: 0
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
remote_send_local_bcast - Force remote-send-local-bcast algorithm
Default: MPIR_CVAR_BCAST_INTER_ALGORITHM_auto
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_binomial - Force Binomial
algorithm
sched_smp - Force smp algorithm
sched_scatter_recursive_doubling_allgather - Force Scatter
Recursive Doubling Allgather algorithm
sched_scatter_ring_allgather - Force Scatter Ring
Allgather algorithm
tsp_tree - Force Generic Transport
Tree algorithm
tsp_scatterv_recexch_allgatherv - Force Generic Transport
Scatterv followed by Recursive Exchange Allgatherv algorithm
tsp_scatterv_ring_allgatherv - Force Generic Transport
Scatterv followed by Ring Allgatherv algorithm
tsp_ring - Force Generic Transport
Ring algorithm
Default: MPIR_CVAR_IBCAST_INTRA_ALGORITHM_auto
MPIR_CVAR_IBCAST_SCATTERV_KVAL
Aliases: MPIR_PARAM_IBCAST_SCATTERV_KVAL
MPICH_IBCAST_SCATTERV_KVAL
Description: k value for tree based scatter in
scatter_recexch_allgather algorithm
Default: 2
MPIR_CVAR_IBCAST_ALLGATHERV_RECEXCH_KVAL
Aliases: MPIR_PARAM_IBCAST_ALLGATHERV_RECEXCH_KVAL
MPICH_IBCAST_ALLGATHERV_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_flat - Force flat algorithm
Default: MPIR_CVAR_IBCAST_INTER_ALGORITHM_auto
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
binomial - Force binomial algorithm
nb - Force nonblocking algorithm
Default: MPIR_CVAR_GATHER_INTRA_ALGORITHM_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
linear - Force linear algorithm
local_gather_remote_send - Force local-gather-remote-send algorithm
nb - Force nonblocking algorithm
Default: MPIR_CVAR_GATHER_INTER_ALGORITHM_auto
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_binomial - Force binomial algorithm
tsp_tree - Force genetric transport based tree algorithm
Default: MPIR_CVAR_IGATHER_INTRA_ALGORITHM_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_long - Force long inter algorithm
sched_short - Force short inter algorithm
Default: MPIR_CVAR_IGATHER_INTER_ALGORITHM_auto
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
linear - Force linear algorithm
nb - Force nonblocking algorithm
Default: MPIR_CVAR_GATHERV_INTRA_ALGORITHM_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
linear - Force linear algorithm
nb - Force nonblocking algorithm
Default: MPIR_CVAR_GATHERV_INTER_ALGORITHM_auto
MPIR_CVAR_IGATHERV_INTRA_ALGORITHM
Aliases: MPIR_PARAM_IGATHERV_INTRA_ALGORITHM
MPICH_IGATHERV_INTRA_ALGORITHM
Description: Variable to select igatherv algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
tsp_linear - Force generic transport based linear algorithm
Default: MPIR_CVAR_IGATHERV_INTRA_ALGORITHM_auto
MPIR_CVAR_IGATHERV_INTER_ALGORITHM
Aliases: MPIR_PARAM_IGATHERV_INTER_ALGORITHM
MPICH_IGATHERV_INTER_ALGORITHM
Description: Variable to select igatherv algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
tsp_linear - Force generic transport based linear algorithm
Default: MPIR_CVAR_IGATHERV_INTER_ALGORITHM_auto
MPIR_CVAR_SCATTER_INTER_SHORT_MSG_SIZE
Aliases: MPIR_PARAM_SCATTER_INTER_SHORT_MSG_SIZE
MPICH_SCATTER_INTER_SHORT_MSG_SIZE
Description: use the short message algorithm for intercommunicator
MPI_Scatter if the send buffer size is < this value (in bytes)
Default: 2048
MPIR_CVAR_SCATTER_INTRA_ALGORITHM
Aliases: MPIR_PARAM_SCATTER_INTRA_ALGORITHM
MPICH_SCATTER_INTRA_ALGORITHM
Description: Variable to select scatter algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
binomial - Force binomial algorithm
nb - Force nonblocking algorithm
Default: MPIR_CVAR_SCATTER_INTRA_ALGORITHM_auto
MPIR_CVAR_SCATTER_INTER_ALGORITHM
Aliases: MPIR_PARAM_SCATTER_INTER_ALGORITHM
MPICH_SCATTER_INTER_ALGORITHM
Description: Variable to select scatter algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
linear - Force linear algorithm
nb - Force nonblocking algorithm
remote_send_local_scatter - Force remote-send-local-scatter
algorithm
Default: MPIR_CVAR_SCATTER_INTER_ALGORITHM_auto
MPIR_CVAR_ISCATTER_INTRA_ALGORITHM
Aliases: MPIR_PARAM_ISCATTER_INTRA_ALGORITHM
MPICH_ISCATTER_INTRA_ALGORITHM
Description: Variable to select iscatter algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_binomial - Force binomial algorithm
tsp_tree - Force genetric transport based tree algorithm
Default: MPIR_CVAR_ISCATTER_INTRA_ALGORITHM_auto
MPIR_CVAR_ISCATTER_TREE_KVAL
Aliases: MPIR_PARAM_ISCATTER_TREE_KVAL
MPICH_ISCATTER_TREE_KVAL
Description: k value for tree based iscatter
Default: 2
MPIR_CVAR_ISCATTER_INTER_ALGORITHM
Aliases: MPIR_PARAM_ISCATTER_INTER_ALGORITHM
MPICH_ISCATTER_INTER_ALGORITHM
Description: Variable to select iscatter algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
sched_remote_send_local_scatter - Force remote-send-local-scatter
algorithm
Default: MPIR_CVAR_ISCATTER_INTER_ALGORITHM_auto
MPIR_CVAR_SCATTERV_INTRA_ALGORITHM
Aliases: MPIR_PARAM_SCATTERV_INTRA_ALGORITHM
MPICH_SCATTERV_INTRA_ALGORITHM
Description: Variable to select scatterv algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
linear - Force linear algorithm
nb - Force nonblocking algorithm
Default: MPIR_CVAR_SCATTERV_INTRA_ALGORITHM_auto
MPIR_CVAR_SCATTERV_INTER_ALGORITHM
Aliases: MPIR_PARAM_SCATTERV_INTER_ALGORITHM
MPICH_SCATTERV_INTER_ALGORITHM
Description: Variable to select scatterv algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
linear - Force linear algorithm
nb - Force nonblocking algorithm
Default: MPIR_CVAR_SCATTERV_INTER_ALGORITHM_auto
MPIR_CVAR_ISCATTERV_INTRA_ALGORITHM
Aliases: MPIR_PARAM_ISCATTERV_INTRA_ALGORITHM
MPICH_ISCATTERV_INTRA_ALGORITHM
Description: Variable to select iscatterv algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
tsp_linear - Force generic transport based linear algorithm
Default: MPIR_CVAR_ISCATTERV_INTRA_ALGORITHM_auto
MPIR_CVAR_ISCATTERV_INTER_ALGORITHM
Aliases: MPIR_PARAM_ISCATTERV_INTER_ALGORITHM
MPICH_ISCATTERV_INTER_ALGORITHM
Description: Variable to select iscatterv algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
tsp_linear - Force generic transport based linear algorithm
Default: MPIR_CVAR_ISCATTERV_INTER_ALGORITHM_auto
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
brucks - Force brucks algorithm
k_brucks - Force brucks algorithm
nb - Force nonblocking algorithm
recursive_doubling - Force recursive doubling algorithm
ring - Force ring algorithm
recexch_doubling - Force recexch distance doubling algorithm
recexch_halving - Force recexch distance halving algorithm
Default: MPIR_CVAR_ALLGATHER_INTRA_ALGORITHM_auto
MPIR_CVAR_ALLGATHER_BRUCKS_KVAL
Aliases: MPIR_PARAM_ALLGATHER_BRUCKS_KVAL
MPICH_ALLGATHER_BRUCKS_KVAL
Description: radix (k) value for generic transport brucks based
allgather
Default: 2
MPIR_CVAR_ALLGATHER_RECEXCH_KVAL
Aliases: MPIR_PARAM_ALLGATHER_RECEXCH_KVAL
MPICH_ALLGATHER_RECEXCH_KVAL
Description: k value for recursive exchange based allgather
Default: 2
MPIR_CVAR_ALLGATHER_RECEXCH_SINGLE_PHASE_RECV
Aliases: MPIR_PARAM_ALLGATHER_RECEXCH_SINGLE_PHASE_RECV
MPICH_ALLGATHER_RECEXCH_SINGLE_PHASE_RECV
Description: This CVAR controls whether the recv is posted for one
phase or two phases in recexch algos. By default, we post the recvs
for 2 phases.
Default: 0
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
local_gather_remote_bcast - Force local-gather-remote-bcast
algorithm
nb - Force nonblocking algorithm
Default: MPIR_CVAR_ALLGATHER_INTER_ALGORITHM_auto
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_ring - Force ring algorithm
sched_brucks - Force brucks algorithm
sched_recursive_doubling - Force recursive doubling algorithm
tsp_ring - Force generic transport ring algorithm
tsp_brucks - Force generic transport based brucks algorithm
tsp_recexch_doubling - Force generic transport recursive exchange
with neighbours doubling in distance in each phase
tsp_recexch_halving - Force generic transport recursive exchange
with neighbours halving in distance in each phase
Default: MPIR_CVAR_IALLGATHER_INTRA_ALGORITHM_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_local_gather_remote_bcast - Force local-gather-remote-bcast
algorithm
Default: MPIR_CVAR_IALLGATHER_INTER_ALGORITHM_auto
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
brucks - Force brucks algorithm
nb - Force nonblocking algorithm
recursive_doubling - Force recursive doubling algorithm
ring - Force ring algorithm
Default: MPIR_CVAR_ALLGATHERV_INTRA_ALGORITHM_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
remote_gather_local_bcast - Force remote-gather-local-bcast
algorithm
Default: MPIR_CVAR_ALLGATHERV_INTER_ALGORITHM_auto
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_BRUCKS_KVAL
Aliases: MPIR_PARAM_IALLGATHERV_BRUCKS_KVAL
MPICH_IALLGATHERV_BRUCKS_KVAL
Description: k value for radix in brucks 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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_brucks - Force brucks algorithm
sched_recursive_doubling - Force recursive doubling algorithm
sched_ring - Force ring algorithm
tsp_recexch_doubling - Force generic transport recursive exchange
with neighbours doubling in distance in each phase
tsp_recexch_halving - Force generic transport recursive exchange
with neighbours halving in distance in each phase
tsp_ring - Force generic transport ring algorithm
tsp_brucks - Force generic transport based brucks
algorithm
Default: MPIR_CVAR_IALLGATHERV_INTRA_ALGORITHM_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_remote_gather_local_bcast - Force remote-gather-local-bcast
algorithm
Default: MPIR_CVAR_IALLGATHERV_INTER_ALGORITHM_auto
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
brucks - Force brucks algorithm
k_brucks - Force Force radix k brucks algorithm
nb - Force nonblocking algorithm
pairwise - Force pairwise algorithm
pairwise_sendrecv_replace - Force pairwise sendrecv replace
algorithm
scattered - Force scattered algorithm
Default: MPIR_CVAR_ALLTOALL_INTRA_ALGORITHM_auto
MPIR_CVAR_ALLTOALL_BRUCKS_KVAL
Aliases: MPIR_PARAM_ALLTOALL_BRUCKS_KVAL
MPICH_ALLTOALL_BRUCKS_KVAL
Description: radix (k) value for generic transport brucks based
alltoall
Default: 2
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
pairwise_exchange - Force pairwise exchange algorithm
Default: MPIR_CVAR_ALLTOALL_INTER_ALGORITHM_auto
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_brucks - Force brucks algorithm
sched_inplace - Force inplace algorithm
sched_pairwise - Force pairwise algorithm
sched_permuted_sendrecv - Force permuted sendrecv algorithm
tsp_ring - Force generic transport based ring algorithm
tsp_brucks - Force generic transport based brucks
algorithm
tsp_scattered - Force generic transport based scattered
algorithm
Default: MPIR_CVAR_IALLTOALL_INTRA_ALGORITHM_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_pairwise_exchange - Force pairwise exchange algorithm
Default: MPIR_CVAR_IALLTOALL_INTER_ALGORITHM_auto
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
pairwise_sendrecv_replace - Force pairwise_sendrecv_replace
algorithm
scattered - Force scattered algorithm
Default: MPIR_CVAR_ALLTOALLV_INTRA_ALGORITHM_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
pairwise_exchange - Force pairwise exchange algorithm
nb - Force nonblocking algorithm
Default: MPIR_CVAR_ALLTOALLV_INTER_ALGORITHM_auto
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_blocked - Force blocked algorithm
sched_inplace - Force inplace algorithm
tsp_scattered - Force generic transport based scattered
algorithm
tsp_blocked - Force generic transport blocked algorithm
tsp_inplace - Force generic transport inplace algorithm
Default: MPIR_CVAR_IALLTOALLV_INTRA_ALGORITHM_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_pairwise_exchange - Force pairwise exchange algorithm
Default: MPIR_CVAR_IALLTOALLV_INTER_ALGORITHM_auto
MPIR_CVAR_IALLTOALLV_SCATTERED_OUTSTANDING_TASKS
Aliases: MPIR_PARAM_IALLTOALLV_SCATTERED_OUTSTANDING_TASKS
MPICH_IALLTOALLV_SCATTERED_OUTSTANDING_TASKS
Description: Maximum number of outstanding sends and recvs posted at a
time
Default: 64
MPIR_CVAR_IALLTOALLV_SCATTERED_BATCH_SIZE
Aliases: MPIR_PARAM_IALLTOALLV_SCATTERED_BATCH_SIZE
MPICH_IALLTOALLV_SCATTERED_BATCH_SIZE
Description: Number of send/receive tasks that scattered algorithm
waits for completion before posting another batch of send/receives
of that size
Default: 4
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
pairwise_sendrecv_replace - Force pairwise sendrecv replace
algorithm
scattered - Force scattered algorithm
Default: MPIR_CVAR_ALLTOALLW_INTRA_ALGORITHM_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
pairwise_exchange - Force pairwise exchange algorithm
Default: MPIR_CVAR_ALLTOALLW_INTER_ALGORITHM_auto
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_blocked - Force blocked algorithm
sched_inplace - Force inplace algorithm
tsp_blocked - Force generic transport based blocked algorithm
tsp_inplace - Force generic transport based inplace algorithm
Default: MPIR_CVAR_IALLTOALLW_INTRA_ALGORITHM_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_pairwise_exchange - Force pairwise exchange algorithm
Default: MPIR_CVAR_IALLTOALLW_INTER_ALGORITHM_auto
MPIR_CVAR_REDUCE_SHORT_MSG_SIZE
Aliases: MPIR_PARAM_REDUCE_SHORT_MSG_SIZE
MPICH_REDUCE_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_MAX_SMP_REDUCE_MSG_SIZE
Aliases: MPIR_PARAM_MAX_SMP_REDUCE_MSG_SIZE
MPICH_MAX_SMP_REDUCE_MSG_SIZE
Description: Maximum message size for which SMP-aware reduce is used.
A value of '0' uses SMP-aware reduce for all message sizes.
Default: 0
MPIR_CVAR_REDUCE_INTRA_ALGORITHM
Aliases: MPIR_PARAM_REDUCE_INTRA_ALGORITHM
MPICH_REDUCE_INTRA_ALGORITHM
Description: Variable to select reduce algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
binomial - Force binomial algorithm
nb - Force nonblocking algorithm
smp - Force smp algorithm
reduce_scatter_gather - Force reduce scatter gather algorithm
Default: MPIR_CVAR_REDUCE_INTRA_ALGORITHM_auto
MPIR_CVAR_REDUCE_INTER_ALGORITHM
Aliases: MPIR_PARAM_REDUCE_INTER_ALGORITHM
MPICH_REDUCE_INTER_ALGORITHM
Description: Variable to select reduce algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
local_reduce_remote_send - Force local-reduce-remote-send algorithm
nb - Force nonblocking algorithm
Default: MPIR_CVAR_REDUCE_INTER_ALGORITHM_auto
MPIR_CVAR_IREDUCE_TREE_KVAL
Aliases: MPIR_PARAM_IREDUCE_TREE_KVAL
MPICH_IREDUCE_TREE_KVAL
Description: k value for tree (kary, knomial, etc.) based ireduce
Default: 2
MPIR_CVAR_IREDUCE_TREE_TYPE
Aliases: MPIR_PARAM_IREDUCE_TREE_TYPE
MPICH_IREDUCE_TREE_TYPE
Description: Tree type for tree based ireduce kary - kary tree
knomial_1 - knomial_1 tree knomial_2 - knomial_2 tree
topology_aware - topology_aware tree type topology_aware_k -
topology_aware tree type with branching factor k topology_wave -
topology_wave tree type
Default: "kary"
MPIR_CVAR_IREDUCE_TOPO_REORDER_ENABLE
Aliases: MPIR_PARAM_IREDUCE_TOPO_REORDER_ENABLE
MPICH_IREDUCE_TOPO_REORDER_ENABLE
Description: This cvar controls if the leaders are reordered based on
the number of ranks in each group.
Default: 1
MPIR_CVAR_IREDUCE_TOPO_OVERHEAD
Aliases: MPIR_PARAM_IREDUCE_TOPO_OVERHEAD
MPICH_IREDUCE_TOPO_OVERHEAD
Description: This cvar controls the size of the overhead.
Default: 200
MPIR_CVAR_IREDUCE_TOPO_DIFF_GROUPS
Aliases: MPIR_PARAM_IREDUCE_TOPO_DIFF_GROUPS
MPICH_IREDUCE_TOPO_DIFF_GROUPS
Description: This cvar controls the latency between different groups.
Default: 2800
MPIR_CVAR_IREDUCE_TOPO_DIFF_SWITCHES
Aliases: MPIR_PARAM_IREDUCE_TOPO_DIFF_SWITCHES
MPICH_IREDUCE_TOPO_DIFF_SWITCHES
Description: This cvar controls the latency between different switches
in the same groups.
Default: 1900
MPIR_CVAR_IREDUCE_TOPO_SAME_SWITCHES
Aliases: MPIR_PARAM_IREDUCE_TOPO_SAME_SWITCHES
MPICH_IREDUCE_TOPO_SAME_SWITCHES
Description: This cvar controls the latency in the same switch.
Default: 1600
MPIR_CVAR_IREDUCE_TREE_PIPELINE_CHUNK_SIZE
Aliases: MPIR_PARAM_IREDUCE_TREE_PIPELINE_CHUNK_SIZE
MPICH_IREDUCE_TREE_PIPELINE_CHUNK_SIZE
Description: Maximum chunk size (in bytes) for pipelining in tree based
ireduce. Default value is 0, that is, no pipelining by default
Default: -1
MPIR_CVAR_IREDUCE_RING_CHUNK_SIZE
Aliases: MPIR_PARAM_IREDUCE_RING_CHUNK_SIZE
MPICH_IREDUCE_RING_CHUNK_SIZE
Description: Maximum chunk size (in bytes) for pipelining in ireduce
ring algorithm. Default value is 0, that is, no pipelining by
default
Default: 0
MPIR_CVAR_IREDUCE_TREE_BUFFER_PER_CHILD
Aliases: MPIR_PARAM_IREDUCE_TREE_BUFFER_PER_CHILD
MPICH_IREDUCE_TREE_BUFFER_PER_CHILD
Description: If set to true, a rank in tree 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_IREDUCE_INTRA_ALGORITHM
Aliases: MPIR_PARAM_IREDUCE_INTRA_ALGORITHM
MPICH_IREDUCE_INTRA_ALGORITHM
Description: Variable to select ireduce algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_smp - Force smp algorithm
sched_binomial - Force binomial algorithm
sched_reduce_scatter_gather - Force reduce scatter gather algorithm
tsp_tree - Force Generic Transport Tree
tsp_ring - Force Generic Transport Ring
Default: MPIR_CVAR_IREDUCE_INTRA_ALGORITHM_auto
MPIR_CVAR_IREDUCE_INTER_ALGORITHM
Aliases: MPIR_PARAM_IREDUCE_INTER_ALGORITHM
MPICH_IREDUCE_INTER_ALGORITHM
Description: Variable to select ireduce algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_local_reduce_remote_send - Force local-reduce-remote-send
algorithm
Default: MPIR_CVAR_IREDUCE_INTER_ALGORITHM_auto
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_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
smp - Force smp algorithm
recursive_doubling - Force recursive doubling algorithm
recursive_multiplying - Force recursive multiplying algorithm
reduce_scatter_allgather - Force reduce scatter allgather algorithm
tree - Force pipelined tree algorithm
recexch - Force generic transport recursive
exchange algorithm
ring - Force ring algorithm
k_reduce_scatter_allgather - Force reduce scatter allgather
algorithm
Default: MPIR_CVAR_ALLREDUCE_INTRA_ALGORITHM_auto
MPIR_CVAR_ALLREDUCE_RECURSIVE_MULTIPLYING_KVAL
Aliases: MPIR_PARAM_ALLREDUCE_RECURSIVE_MULTIPLYING_KVAL
MPICH_ALLREDUCE_RECURSIVE_MULTIPLYING_KVAL
Description: radix value (power of k) for generic recursive multiplying
based allreduce
Default: 2
MPIR_CVAR_ALLREDUCE_TREE_TYPE
Aliases: MPIR_PARAM_ALLREDUCE_TREE_TYPE
MPICH_ALLREDUCE_TREE_TYPE
Description: Tree type for tree based allreduce knomial_1 is default as
it supports both commutative and non-commutative reduce operations
kary - kary tree type knomial_1 - knomial_1 tree type (tree
grows starting from the left of the root) knomial_2 - knomial_2
tree type (tree grows starting from the right of the root)
topology_aware - topology_aware tree type topology_aware_k -
topology_aware tree type with branching factor k topology_wave -
topology_wave tree type
Default: "knomial_1"
MPIR_CVAR_ALLREDUCE_TREE_KVAL
Aliases: MPIR_PARAM_ALLREDUCE_TREE_KVAL
MPICH_ALLREDUCE_TREE_KVAL
Description: Indicates the branching factor for kary or knomial trees.
Default: 2
MPIR_CVAR_ALLREDUCE_TOPO_REORDER_ENABLE
Aliases: MPIR_PARAM_ALLREDUCE_TOPO_REORDER_ENABLE
MPICH_ALLREDUCE_TOPO_REORDER_ENABLE
Description: This cvar controls if the leaders are reordered based on
the number of ranks in each group.
Default: 1
MPIR_CVAR_ALLREDUCE_TOPO_OVERHEAD
Aliases: MPIR_PARAM_ALLREDUCE_TOPO_OVERHEAD
MPICH_ALLREDUCE_TOPO_OVERHEAD
Description: This cvar controls the size of the overhead.
Default: 200
MPIR_CVAR_ALLREDUCE_TOPO_DIFF_GROUPS
Aliases: MPIR_PARAM_ALLREDUCE_TOPO_DIFF_GROUPS
MPICH_ALLREDUCE_TOPO_DIFF_GROUPS
Description: This cvar controls the latency between different groups.
Default: 2800
MPIR_CVAR_ALLREDUCE_TOPO_DIFF_SWITCHES
Aliases: MPIR_PARAM_ALLREDUCE_TOPO_DIFF_SWITCHES
MPICH_ALLREDUCE_TOPO_DIFF_SWITCHES
Description: This cvar controls the latency between different switches
in the same groups.
Default: 1900
MPIR_CVAR_ALLREDUCE_TOPO_SAME_SWITCHES
Aliases: MPIR_PARAM_ALLREDUCE_TOPO_SAME_SWITCHES
MPICH_ALLREDUCE_TOPO_SAME_SWITCHES
Description: This cvar controls the latency in the same switch.
Default: 1600
MPIR_CVAR_ALLREDUCE_TREE_PIPELINE_CHUNK_SIZE
Aliases: MPIR_PARAM_ALLREDUCE_TREE_PIPELINE_CHUNK_SIZE
MPICH_ALLREDUCE_TREE_PIPELINE_CHUNK_SIZE
Description: Maximum chunk size (in bytes) for pipelining in tree based
allreduce. Default value is 0, that is, no pipelining by default
Default: 0
MPIR_CVAR_ALLREDUCE_TREE_BUFFER_PER_CHILD
Aliases: MPIR_PARAM_ALLREDUCE_TREE_BUFFER_PER_CHILD
MPICH_ALLREDUCE_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_ALLREDUCE_RECEXCH_KVAL
Aliases: MPIR_PARAM_ALLREDUCE_RECEXCH_KVAL
MPICH_ALLREDUCE_RECEXCH_KVAL
Description: k value for recursive exchange based allreduce
Default: 2
MPIR_CVAR_ALLREDUCE_RECEXCH_SINGLE_PHASE_RECV
Aliases: MPIR_PARAM_ALLREDUCE_RECEXCH_SINGLE_PHASE_RECV
MPICH_ALLREDUCE_RECEXCH_SINGLE_PHASE_RECV
Description: This CVAR controls whether the recv is posted for one
phase or two phases in recexch algos. By default, we post the recvs
for 2 phases.
Default: 0
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
reduce_exchange_bcast - Force reduce-exchange-bcast algorithm
Default: MPIR_CVAR_ALLREDUCE_INTER_ALGORITHM_auto
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_TYPE
Aliases: MPIR_PARAM_IALLREDUCE_TREE_TYPE
MPICH_IALLREDUCE_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_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. Default value is 0, that is, no pipelining by default
Default: 0
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_naive - Force naive algorithm
sched_smp - Force smp algorithm
sched_recursive_doubling - Force recursive doubling
algorithm
sched_reduce_scatter_allgather - Force reduce scatter allgather
algorithm
tsp_recexch_single_buffer - Force generic transport recursive
exchange with single buffer for receives
tsp_recexch_multiple_buffer - Force generic transport recursive
exchange with multiple buffers for receives
tsp_tree - Force generic transport tree
algorithm
tsp_ring - Force generic transport ring
algorithm
tsp_recexch_reduce_scatter_recexch_allgatherv - Force generic
transport recursive exchange with reduce scatter and allgatherv
Default: MPIR_CVAR_IALLREDUCE_INTRA_ALGORITHM_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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_remote_reduce_local_bcast - Force remote-reduce-local-bcast
algorithm
Default: MPIR_CVAR_IALLREDUCE_INTER_ALGORITHM_auto
MPIR_CVAR_REDUCE_SCATTER_COMMUTATIVE_LONG_MSG_SIZE
Aliases: MPIR_PARAM_REDUCE_SCATTER_COMMUTATIVE_LONG_MSG_SIZE
MPICH_REDUCE_SCATTER_COMMUTATIVE_LONG_MSG_SIZE
Description: the long message algorithm will be used if the operation
is commutative and the send buffer size is >= this value (in bytes)
Default: 524288
MPIR_CVAR_REDUCE_SCATTER_INTRA_ALGORITHM
Aliases: MPIR_PARAM_REDUCE_SCATTER_INTRA_ALGORITHM
MPICH_REDUCE_SCATTER_INTRA_ALGORITHM
Description: Variable to select reduce_scatter algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
noncommutative - Force noncommutative algorithm
pairwise - Force pairwise algorithm
recursive_doubling - Force recursive doubling algorithm
recursive_halving - Force recursive halving algorithm
Default: MPIR_CVAR_REDUCE_SCATTER_INTRA_ALGORITHM_auto
MPIR_CVAR_REDUCE_SCATTER_INTER_ALGORITHM
Aliases: MPIR_PARAM_REDUCE_SCATTER_INTER_ALGORITHM
MPICH_REDUCE_SCATTER_INTER_ALGORITHM
Description: Variable to select reduce_scatter algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
remote_reduce_local_scatter - Force remote-reduce-local-scatter
algorithm
Default: MPIR_CVAR_REDUCE_SCATTER_INTER_ALGORITHM_auto
MPIR_CVAR_IREDUCE_SCATTER_RECEXCH_KVAL
Aliases: MPIR_PARAM_IREDUCE_SCATTER_RECEXCH_KVAL
MPICH_IREDUCE_SCATTER_RECEXCH_KVAL
Description: k value for recursive exchange based ireduce_scatter
Default: 2
MPIR_CVAR_IREDUCE_SCATTER_INTRA_ALGORITHM
Aliases: MPIR_PARAM_IREDUCE_SCATTER_INTRA_ALGORITHM
MPICH_IREDUCE_SCATTER_INTRA_ALGORITHM
Description: Variable to select ireduce_scatter algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_noncommutative - Force noncommutative algorithm
sched_recursive_doubling - Force recursive doubling algorithm
sched_pairwise - Force pairwise algorithm
sched_recursive_halving - Force recursive halving algorithm
tsp_recexch - Force generic transport recursive exchange
algorithm
Default: MPIR_CVAR_IREDUCE_SCATTER_INTRA_ALGORITHM_auto
MPIR_CVAR_IREDUCE_SCATTER_INTER_ALGORITHM
Aliases: MPIR_PARAM_IREDUCE_SCATTER_INTER_ALGORITHM
MPICH_IREDUCE_SCATTER_INTER_ALGORITHM
Description: Variable to select ireduce_scatter algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_remote_reduce_local_scatterv - Force
remote-reduce-local-scatterv algorithm
Default: MPIR_CVAR_IREDUCE_SCATTER_INTER_ALGORITHM_auto
MPIR_CVAR_REDUCE_SCATTER_BLOCK_INTRA_ALGORITHM
Aliases: MPIR_PARAM_REDUCE_SCATTER_BLOCK_INTRA_ALGORITHM
MPICH_REDUCE_SCATTER_BLOCK_INTRA_ALGORITHM
Description: Variable to select reduce_scatter_block algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
noncommutative - Force noncommutative algorithm
recursive_doubling - Force recursive doubling algorithm
pairwise - Force pairwise algorithm
recursive_halving - Force recursive halving algorithm
nb - Force nonblocking algorithm
Default: MPIR_CVAR_REDUCE_SCATTER_BLOCK_INTRA_ALGORITHM_auto
MPIR_CVAR_REDUCE_SCATTER_BLOCK_INTER_ALGORITHM
Aliases: MPIR_PARAM_REDUCE_SCATTER_BLOCK_INTER_ALGORITHM
MPICH_REDUCE_SCATTER_BLOCK_INTER_ALGORITHM
Description: Variable to select reduce_scatter_block algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
remote_reduce_local_scatter - Force remote-reduce-local-scatter
algorithm
Default: MPIR_CVAR_REDUCE_SCATTER_BLOCK_INTER_ALGORITHM_auto
MPIR_CVAR_IREDUCE_SCATTER_BLOCK_RECEXCH_KVAL
Aliases: MPIR_PARAM_IREDUCE_SCATTER_BLOCK_RECEXCH_KVAL
MPICH_IREDUCE_SCATTER_BLOCK_RECEXCH_KVAL
Description: k value for recursive exchange based ireduce_scatter_block
Default: 2
MPIR_CVAR_IREDUCE_SCATTER_BLOCK_INTRA_ALGORITHM
Aliases: MPIR_PARAM_IREDUCE_SCATTER_BLOCK_INTRA_ALGORITHM
MPICH_IREDUCE_SCATTER_BLOCK_INTRA_ALGORITHM
Description: Variable to select ireduce_scatter_block algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_noncommutative - Force noncommutative algorithm
sched_recursive_doubling - Force recursive doubling algorithm
sched_pairwise - Force pairwise algorithm
sched_recursive_halving - Force recursive halving algorithm
tsp_recexch - Force generic transport recursive exchange
algorithm
Default: MPIR_CVAR_IREDUCE_SCATTER_BLOCK_INTRA_ALGORITHM_auto
MPIR_CVAR_IREDUCE_SCATTER_BLOCK_INTER_ALGORITHM
Aliases: MPIR_PARAM_IREDUCE_SCATTER_BLOCK_INTER_ALGORITHM
MPICH_IREDUCE_SCATTER_BLOCK_INTER_ALGORITHM
Description: Variable to select ireduce_scatter_block algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_remote_reduce_local_scatterv - Force
remote-reduce-local-scatterv algorithm
Default: MPIR_CVAR_IREDUCE_SCATTER_BLOCK_INTER_ALGORITHM_auto
MPIR_CVAR_SCAN_INTRA_ALGORITHM
Aliases: MPIR_PARAM_SCAN_INTRA_ALGORITHM
MPICH_SCAN_INTRA_ALGORITHM
Description: Variable to select allgather algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
smp - Force smp algorithm
recursive_doubling - Force recursive doubling algorithm
Default: MPIR_CVAR_SCAN_INTRA_ALGORITHM_auto
MPIR_CVAR_ISCAN_INTRA_ALGORITHM
Aliases: MPIR_PARAM_ISCAN_INTRA_ALGORITHM
MPICH_ISCAN_INTRA_ALGORITHM
Description: Variable to select allgather algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_smp - Force smp algorithm
sched_recursive_doubling - Force recursive doubling algorithm
tsp_recursive_doubling - Force generic transport recursive doubling
algorithm
Default: MPIR_CVAR_ISCAN_INTRA_ALGORITHM_auto
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
recursive_doubling - Force recursive doubling algorithm
Default: MPIR_CVAR_EXSCAN_INTRA_ALGORITHM_auto
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 (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_recursive_doubling - Force recursive doubling algorithm
Default: MPIR_CVAR_IEXSCAN_INTRA_ALGORITHM_auto
MPIR_CVAR_NEIGHBOR_ALLGATHER_INTRA_ALGORITHM
Aliases: MPIR_PARAM_NEIGHBOR_ALLGATHER_INTRA_ALGORITHM
MPICH_NEIGHBOR_ALLGATHER_INTRA_ALGORITHM
Description: Variable to select ineighbor_allgather algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
Default: MPIR_CVAR_NEIGHBOR_ALLGATHER_INTRA_ALGORITHM_auto
MPIR_CVAR_NEIGHBOR_ALLGATHER_INTER_ALGORITHM
Aliases: MPIR_PARAM_NEIGHBOR_ALLGATHER_INTER_ALGORITHM
MPICH_NEIGHBOR_ALLGATHER_INTER_ALGORITHM
Description: Variable to select ineighbor_allgather algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nonblocking algorithm
Default: MPIR_CVAR_NEIGHBOR_ALLGATHER_INTER_ALGORITHM_auto
MPIR_CVAR_INEIGHBOR_ALLGATHER_INTRA_ALGORITHM
Aliases: MPIR_PARAM_INEIGHBOR_ALLGATHER_INTRA_ALGORITHM
MPICH_INEIGHBOR_ALLGATHER_INTRA_ALGORITHM
Description: Variable to select ineighbor_allgather algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
tsp_linear - Force generic transport based linear algorithm
Default: MPIR_CVAR_INEIGHBOR_ALLGATHER_INTRA_ALGORITHM_auto
MPIR_CVAR_INEIGHBOR_ALLGATHER_INTER_ALGORITHM
Aliases: MPIR_PARAM_INEIGHBOR_ALLGATHER_INTER_ALGORITHM
MPICH_INEIGHBOR_ALLGATHER_INTER_ALGORITHM
Description: Variable to select ineighbor_allgather algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
tsp_linear - Force generic transport based linear algorithm
Default: MPIR_CVAR_INEIGHBOR_ALLGATHER_INTER_ALGORITHM_auto
MPIR_CVAR_NEIGHBOR_ALLGATHERV_INTRA_ALGORITHM
Aliases: MPIR_PARAM_NEIGHBOR_ALLGATHERV_INTRA_ALGORITHM
MPICH_NEIGHBOR_ALLGATHERV_INTRA_ALGORITHM
Description: Variable to select neighbor_allgatherv algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nb algorithm
Default: MPIR_CVAR_NEIGHBOR_ALLGATHERV_INTRA_ALGORITHM_auto
MPIR_CVAR_NEIGHBOR_ALLGATHERV_INTER_ALGORITHM
Aliases: MPIR_PARAM_NEIGHBOR_ALLGATHERV_INTER_ALGORITHM
MPICH_NEIGHBOR_ALLGATHERV_INTER_ALGORITHM
Description: Variable to select neighbor_allgatherv algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nb algorithm
Default: MPIR_CVAR_NEIGHBOR_ALLGATHERV_INTER_ALGORITHM_auto
MPIR_CVAR_INEIGHBOR_ALLGATHERV_INTRA_ALGORITHM
Aliases: MPIR_PARAM_INEIGHBOR_ALLGATHERV_INTRA_ALGORITHM
MPICH_INEIGHBOR_ALLGATHERV_INTRA_ALGORITHM
Description: Variable to select ineighbor_allgatherv algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
tsp_linear - Force generic transport based linear algorithm
Default: MPIR_CVAR_INEIGHBOR_ALLGATHERV_INTRA_ALGORITHM_auto
MPIR_CVAR_INEIGHBOR_ALLGATHERV_INTER_ALGORITHM
Aliases: MPIR_PARAM_INEIGHBOR_ALLGATHERV_INTER_ALGORITHM
MPICH_INEIGHBOR_ALLGATHERV_INTER_ALGORITHM
Description: Variable to select ineighbor_allgatherv algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
tsp_linear - Force generic transport based linear algorithm
Default: MPIR_CVAR_INEIGHBOR_ALLGATHERV_INTER_ALGORITHM_auto
MPIR_CVAR_NEIGHBOR_ALLTOALL_INTRA_ALGORITHM
Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALL_INTRA_ALGORITHM
MPICH_NEIGHBOR_ALLTOALL_INTRA_ALGORITHM
Description: Variable to select neighbor_alltoall algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nb algorithm
Default: MPIR_CVAR_NEIGHBOR_ALLTOALL_INTRA_ALGORITHM_auto
MPIR_CVAR_NEIGHBOR_ALLTOALL_INTER_ALGORITHM
Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALL_INTER_ALGORITHM
MPICH_NEIGHBOR_ALLTOALL_INTER_ALGORITHM
Description: Variable to select neighbor_alltoall algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nb algorithm
Default: MPIR_CVAR_NEIGHBOR_ALLTOALL_INTER_ALGORITHM_auto
MPIR_CVAR_INEIGHBOR_ALLTOALL_INTRA_ALGORITHM
Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALL_INTRA_ALGORITHM
MPICH_INEIGHBOR_ALLTOALL_INTRA_ALGORITHM
Description: Variable to select ineighbor_alltoall algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
tsp_linear - Force generic transport based linear algorithm
Default: MPIR_CVAR_INEIGHBOR_ALLTOALL_INTRA_ALGORITHM_auto
MPIR_CVAR_INEIGHBOR_ALLTOALL_INTER_ALGORITHM
Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALL_INTER_ALGORITHM
MPICH_INEIGHBOR_ALLTOALL_INTER_ALGORITHM
Description: Variable to select ineighbor_alltoall algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
tsp_linear - Force generic transport based linear algorithm
Default: MPIR_CVAR_INEIGHBOR_ALLTOALL_INTER_ALGORITHM_auto
MPIR_CVAR_NEIGHBOR_ALLTOALLV_INTRA_ALGORITHM
Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALLV_INTRA_ALGORITHM
MPICH_NEIGHBOR_ALLTOALLV_INTRA_ALGORITHM
Description: Variable to select neighbor_alltoallv algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nb algorithm
Default: MPIR_CVAR_NEIGHBOR_ALLTOALLV_INTRA_ALGORITHM_auto
MPIR_CVAR_NEIGHBOR_ALLTOALLV_INTER_ALGORITHM
Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALLV_INTER_ALGORITHM
MPICH_NEIGHBOR_ALLTOALLV_INTER_ALGORITHM
Description: Variable to select neighbor_alltoallv algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nb algorithm
Default: MPIR_CVAR_NEIGHBOR_ALLTOALLV_INTER_ALGORITHM_auto
MPIR_CVAR_INEIGHBOR_ALLTOALLV_INTRA_ALGORITHM
Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALLV_INTRA_ALGORITHM
MPICH_INEIGHBOR_ALLTOALLV_INTRA_ALGORITHM
Description: Variable to select ineighbor_alltoallv algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
tsp_linear - Force generic transport based linear algorithm
Default: MPIR_CVAR_INEIGHBOR_ALLTOALLV_INTRA_ALGORITHM_auto
MPIR_CVAR_INEIGHBOR_ALLTOALLV_INTER_ALGORITHM
Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALLV_INTER_ALGORITHM
MPICH_INEIGHBOR_ALLTOALLV_INTER_ALGORITHM
Description: Variable to select ineighbor_alltoallv algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
tsp_linear - Force generic transport based linear algorithm
Default: MPIR_CVAR_INEIGHBOR_ALLTOALLV_INTER_ALGORITHM_auto
MPIR_CVAR_NEIGHBOR_ALLTOALLW_INTRA_ALGORITHM
Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALLW_INTRA_ALGORITHM
MPICH_NEIGHBOR_ALLTOALLW_INTRA_ALGORITHM
Description: Variable to select neighbor_alltoallw algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nb algorithm
Default: MPIR_CVAR_NEIGHBOR_ALLTOALLW_INTRA_ALGORITHM_auto
MPIR_CVAR_NEIGHBOR_ALLTOALLW_INTER_ALGORITHM
Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALLW_INTER_ALGORITHM
MPICH_NEIGHBOR_ALLTOALLW_INTER_ALGORITHM
Description: Variable to select neighbor_alltoallw algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
nb - Force nb algorithm
Default: MPIR_CVAR_NEIGHBOR_ALLTOALLW_INTER_ALGORITHM_auto
MPIR_CVAR_INEIGHBOR_ALLTOALLW_INTRA_ALGORITHM
Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALLW_INTRA_ALGORITHM
MPICH_INEIGHBOR_ALLTOALLW_INTRA_ALGORITHM
Description: Variable to select ineighbor_alltoallw algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
tsp_linear - Force generic transport based linear algorithm
Default: MPIR_CVAR_INEIGHBOR_ALLTOALLW_INTRA_ALGORITHM_auto
MPIR_CVAR_INEIGHBOR_ALLTOALLW_INTER_ALGORITHM
Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALLW_INTER_ALGORITHM
MPICH_INEIGHBOR_ALLTOALLW_INTER_ALGORITHM
Description: Variable to select ineighbor_alltoallw algorithm
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE)
sched_auto - Internal algorithm selection for sched-based
algorithms
sched_linear - Force linear algorithm
tsp_linear - Force generic transport based linear algorithm
Default: MPIR_CVAR_INEIGHBOR_ALLTOALLW_INTER_ALGORITHM_auto
MPIR_CVAR_BARRIER_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_BARRIER_DEVICE_COLLECTIVE
MPICH_BARRIER_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Barrier will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_IBARRIER_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_IBARRIER_DEVICE_COLLECTIVE
MPICH_IBARRIER_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Ibarrier will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_BARRIER_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_BARRIER_INIT_DEVICE_COLLECTIVE
MPICH_BARRIER_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Barrier will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_BCAST_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_BCAST_DEVICE_COLLECTIVE
MPICH_BCAST_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Bcast will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_IBCAST_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_IBCAST_DEVICE_COLLECTIVE
MPICH_IBCAST_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Ibcast will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_BCAST_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_BCAST_INIT_DEVICE_COLLECTIVE
MPICH_BCAST_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Bcast_init will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_GATHER_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_GATHER_DEVICE_COLLECTIVE
MPICH_GATHER_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Gather will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_IGATHER_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_IGATHER_DEVICE_COLLECTIVE
MPICH_IGATHER_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Igather will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_GATHER_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_GATHER_INIT_DEVICE_COLLECTIVE
MPICH_GATHER_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Gather_init will allow
the device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_GATHERV_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_GATHERV_DEVICE_COLLECTIVE
MPICH_GATHERV_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Gatherv will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_IGATHERV_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_IGATHERV_DEVICE_COLLECTIVE
MPICH_IGATHERV_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Igatherv will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_GATHERV_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_GATHERV_INIT_DEVICE_COLLECTIVE
MPICH_GATHERV_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Gatherv_init will allow
the device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_SCATTER_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_SCATTER_DEVICE_COLLECTIVE
MPICH_SCATTER_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Scatter will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ISCATTER_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ISCATTER_DEVICE_COLLECTIVE
MPICH_ISCATTER_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Iscatter will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_SCATTER_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_SCATTER_INIT_DEVICE_COLLECTIVE
MPICH_SCATTER_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Scatter_init will allow
the device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_SCATTERV_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_SCATTERV_DEVICE_COLLECTIVE
MPICH_SCATTERV_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Scatterv will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ISCATTERV_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ISCATTERV_DEVICE_COLLECTIVE
MPICH_ISCATTERV_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Iscatterv will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_SCATTERV_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_SCATTERV_INIT_DEVICE_COLLECTIVE
MPICH_SCATTERV_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Scatterv_init will allow
the device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ALLGATHER_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ALLGATHER_DEVICE_COLLECTIVE
MPICH_ALLGATHER_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Allgather will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_IALLGATHER_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_IALLGATHER_DEVICE_COLLECTIVE
MPICH_IALLGATHER_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Iallgather will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ALLGATHER_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ALLGATHER_INIT_DEVICE_COLLECTIVE
MPICH_ALLGATHER_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Allgather_init will allow
the device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ALLGATHERV_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ALLGATHERV_DEVICE_COLLECTIVE
MPICH_ALLGATHERV_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Allgatherv will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_IALLGATHERV_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_IALLGATHERV_DEVICE_COLLECTIVE
MPICH_IALLGATHERV_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Iallgatherv will allow
the device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ALLGATHERV_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ALLGATHERV_INIT_DEVICE_COLLECTIVE
MPICH_ALLGATHERV_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Allgatherv_init will
allow the device to override the MPIR-level collective algorithms.
The device might still call the MPIR-level algorithms manually. If
set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ALLTOALL_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ALLTOALL_DEVICE_COLLECTIVE
MPICH_ALLTOALL_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Alltoall will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_IALLTOALL_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_IALLTOALL_DEVICE_COLLECTIVE
MPICH_IALLTOALL_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Ialltoall will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ALLTOALL_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ALLTOALL_INIT_DEVICE_COLLECTIVE
MPICH_ALLTOALL_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Alltoall_init will allow
the device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ALLTOALLV_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ALLTOALLV_DEVICE_COLLECTIVE
MPICH_ALLTOALLV_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Alltoallv will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_IALLTOALLV_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_IALLTOALLV_DEVICE_COLLECTIVE
MPICH_IALLTOALLV_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Ialltoallv will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ALLTOALLV_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ALLTOALLV_INIT_DEVICE_COLLECTIVE
MPICH_ALLTOALLV_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Alltoallv_init will allow
the device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ALLTOALLW_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ALLTOALLW_DEVICE_COLLECTIVE
MPICH_ALLTOALLW_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Alltoallw will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_IALLTOALLW_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_IALLTOALLW_DEVICE_COLLECTIVE
MPICH_IALLTOALLW_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Ialltoallw will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ALLTOALLW_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ALLTOALLW_INIT_DEVICE_COLLECTIVE
MPICH_ALLTOALLW_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Alltoallw_init will allow
the device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_REDUCE_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_REDUCE_DEVICE_COLLECTIVE
MPICH_REDUCE_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Reduce will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_IREDUCE_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_IREDUCE_DEVICE_COLLECTIVE
MPICH_IREDUCE_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Ireduce will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_REDUCE_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_REDUCE_INIT_DEVICE_COLLECTIVE
MPICH_REDUCE_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Reduce_init will allow
the device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ALLREDUCE_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ALLREDUCE_DEVICE_COLLECTIVE
MPICH_ALLREDUCE_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Allreduce will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_IALLREDUCE_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_IALLREDUCE_DEVICE_COLLECTIVE
MPICH_IALLREDUCE_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Iallreduce will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ALLREDUCE_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ALLREDUCE_INIT_DEVICE_COLLECTIVE
MPICH_ALLREDUCE_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Allreduce_init will allow
the device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_REDUCE_SCATTER_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_REDUCE_SCATTER_DEVICE_COLLECTIVE
MPICH_REDUCE_SCATTER_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Reduce_scatter will allow
the device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_IREDUCE_SCATTER_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_IREDUCE_SCATTER_DEVICE_COLLECTIVE
MPICH_IREDUCE_SCATTER_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Ireduce_scatter will
allow the device to override the MPIR-level collective algorithms.
The device might still call the MPIR-level algorithms manually. If
set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_REDUCE_SCATTER_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_REDUCE_SCATTER_INIT_DEVICE_COLLECTIVE
MPICH_REDUCE_SCATTER_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Reduce_scatter_init will
allow the device to override the MPIR-level collective algorithms.
The device might still call the MPIR-level algorithms manually. If
set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_REDUCE_SCATTER_BLOCK_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_REDUCE_SCATTER_BLOCK_DEVICE_COLLECTIVE
MPICH_REDUCE_SCATTER_BLOCK_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Reduce_scatter_block will
allow the device to override the MPIR-level collective algorithms.
The device might still call the MPIR-level algorithms manually. If
set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_IREDUCE_SCATTER_BLOCK_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_IREDUCE_SCATTER_BLOCK_DEVICE_COLLECTIVE
MPICH_IREDUCE_SCATTER_BLOCK_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Ireduce_scatter_block
will allow the device to override the MPIR-level collective
algorithms. The device might still call the MPIR-level algorithms
manually. If set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_REDUCE_SCATTER_BLOCK_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_REDUCE_SCATTER_BLOCK_INIT_DEVICE_COLLECTIVE
MPICH_REDUCE_SCATTER_BLOCK_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Reduce_scatter_block_init
will allow the device to override the MPIR-level collective
algorithms. The device might still call the MPIR-level algorithms
manually. If set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_SCAN_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_SCAN_DEVICE_COLLECTIVE
MPICH_SCAN_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Scan will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_ISCAN_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_ISCAN_DEVICE_COLLECTIVE
MPICH_ISCAN_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Iscan will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_SCAN_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_SCAN_INIT_DEVICE_COLLECTIVE
MPICH_SCAN_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Scan_init will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_EXSCAN_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_EXSCAN_DEVICE_COLLECTIVE
MPICH_EXSCAN_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Exscan will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_IEXSCAN_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_IEXSCAN_DEVICE_COLLECTIVE
MPICH_IEXSCAN_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Iexscan will allow the
device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_EXSCAN_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_EXSCAN_INIT_DEVICE_COLLECTIVE
MPICH_EXSCAN_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Exscan_init will allow
the device to override the MPIR-level collective algorithms. The
device might still call the MPIR-level algorithms manually. If set
to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_NEIGHBOR_ALLGATHER_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_NEIGHBOR_ALLGATHER_DEVICE_COLLECTIVE
MPICH_NEIGHBOR_ALLGATHER_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Neighbor_allgather will
allow the device to override the MPIR-level collective algorithms.
The device might still call the MPIR-level algorithms manually. If
set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_INEIGHBOR_ALLGATHER_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_INEIGHBOR_ALLGATHER_DEVICE_COLLECTIVE
MPICH_INEIGHBOR_ALLGATHER_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Ineighbor_allgather will
allow the device to override the MPIR-level collective algorithms.
The device might still call the MPIR-level algorithms manually. If
set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_NEIGHBOR_ALLGATHER_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_NEIGHBOR_ALLGATHER_INIT_DEVICE_COLLECTIVE
MPICH_NEIGHBOR_ALLGATHER_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Neighbor_allgather_init
will allow the device to override the MPIR-level collective
algorithms. The device might still call the MPIR-level algorithms
manually. If set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_NEIGHBOR_ALLGATHERV_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_NEIGHBOR_ALLGATHERV_DEVICE_COLLECTIVE
MPICH_NEIGHBOR_ALLGATHERV_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Neighbor_allgatherv will
allow the device to override the MPIR-level collective algorithms.
The device might still call the MPIR-level algorithms manually. If
set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_INEIGHBOR_ALLGATHERV_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_INEIGHBOR_ALLGATHERV_DEVICE_COLLECTIVE
MPICH_INEIGHBOR_ALLGATHERV_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Ineighbor_allgatherv will
allow the device to override the MPIR-level collective algorithms.
The device might still call the MPIR-level algorithms manually. If
set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_NEIGHBOR_ALLGATHERV_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_NEIGHBOR_ALLGATHERV_INIT_DEVICE_COLLECTIVE
MPICH_NEIGHBOR_ALLGATHERV_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Neighbor_allgatherv_init
will allow the device to override the MPIR-level collective
algorithms. The device might still call the MPIR-level algorithms
manually. If set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_NEIGHBOR_ALLTOALL_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALL_DEVICE_COLLECTIVE
MPICH_NEIGHBOR_ALLTOALL_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Neighbor_alltoall will
allow the device to override the MPIR-level collective algorithms.
The device might still call the MPIR-level algorithms manually. If
set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_INEIGHBOR_ALLTOALL_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALL_DEVICE_COLLECTIVE
MPICH_INEIGHBOR_ALLTOALL_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Ineighbor_alltoall will
allow the device to override the MPIR-level collective algorithms.
The device might still call the MPIR-level algorithms manually. If
set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_NEIGHBOR_ALLTOALL_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALL_INIT_DEVICE_COLLECTIVE
MPICH_NEIGHBOR_ALLTOALL_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Neighbor_alltoall_init
will allow the device to override the MPIR-level collective
algorithms. The device might still call the MPIR-level algorithms
manually. If set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_NEIGHBOR_ALLTOALLV_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALLV_DEVICE_COLLECTIVE
MPICH_NEIGHBOR_ALLTOALLV_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Neighbor_alltoallv will
allow the device to override the MPIR-level collective algorithms.
The device might still call the MPIR-level algorithms manually. If
set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_INEIGHBOR_ALLTOALLV_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALLV_DEVICE_COLLECTIVE
MPICH_INEIGHBOR_ALLTOALLV_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Ineighbor_alltoallv will
allow the device to override the MPIR-level collective algorithms.
The device might still call the MPIR-level algorithms manually. If
set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_NEIGHBOR_ALLTOALLV_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALLV_INIT_DEVICE_COLLECTIVE
MPICH_NEIGHBOR_ALLTOALLV_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Neighbor_alltoallv_init
will allow the device to override the MPIR-level collective
algorithms. The device might still call the MPIR-level algorithms
manually. If set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_NEIGHBOR_ALLTOALLW_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALLW_DEVICE_COLLECTIVE
MPICH_NEIGHBOR_ALLTOALLW_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Neighbor_alltoallw will
allow the device to override the MPIR-level collective algorithms.
The device might still call the MPIR-level algorithms manually. If
set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_INEIGHBOR_ALLTOALLW_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_INEIGHBOR_ALLTOALLW_DEVICE_COLLECTIVE
MPICH_INEIGHBOR_ALLTOALLW_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Ineighbor_alltoallw will
allow the device to override the MPIR-level collective algorithms.
The device might still call the MPIR-level algorithms manually. If
set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_NEIGHBOR_ALLTOALLW_INIT_DEVICE_COLLECTIVE
Aliases: MPIR_PARAM_NEIGHBOR_ALLTOALLW_INIT_DEVICE_COLLECTIVE
MPICH_NEIGHBOR_ALLTOALLW_INIT_DEVICE_COLLECTIVE
Description: This CVAR is only used when MPIR_CVAR_DEVICE_COLLECTIVES
is set to "percoll". If set to true, MPI_Neighbor_alltoallw_init
will allow the device to override the MPIR-level collective
algorithms. The device might still call the MPIR-level algorithms
manually. If set to false, the device-override will be disabled.
Default: 1
MPIR_CVAR_COLL_HYBRID_MEMORY
Aliases: MPIR_PARAM_COLL_HYBRID_MEMORY
MPICH_COLL_HYBRID_MEMORY
Description: This cvar indicates if the memory used in the collective
operations are the same type. It set to true, it means in a
collective operation, some buffers could be on the CPU and some
buffers could be on the GPU. If set to false, it means all the data
in a collective operation are on the same type of memory.
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_IALLTOALL_BRUCKS_KVAL
Aliases: MPIR_PARAM_IALLTOALL_BRUCKS_KVAL
MPICH_IALLTOALL_BRUCKS_KVAL
Description: radix (k) value for generic transport brucks based
ialltoall
Default: 2
MPIR_CVAR_IALLTOALL_BRUCKS_BUFFER_PER_NBR
Aliases: MPIR_PARAM_IALLTOALL_BRUCKS_BUFFER_PER_NBR
MPICH_IALLTOALL_BRUCKS_BUFFER_PER_NBR
Description: If set to true, the tsp based brucks algorithm will
allocate dedicated send and receive buffers for every neighbor in
the brucks algorithm. Otherwise, it would reuse a single buffer for
sending and receiving data to/from neighbors
Default: 0
MPIR_CVAR_IALLTOALL_SCATTERED_OUTSTANDING_TASKS
Aliases: MPIR_PARAM_IALLTOALL_SCATTERED_OUTSTANDING_TASKS
MPICH_IALLTOALL_SCATTERED_OUTSTANDING_TASKS
Description: Maximum number of outstanding sends and recvs posted at a
time
Default: 64
MPIR_CVAR_IALLTOALL_SCATTERED_BATCH_SIZE
Aliases: MPIR_PARAM_IALLTOALL_SCATTERED_BATCH_SIZE
MPICH_IALLTOALL_SCATTERED_BATCH_SIZE
Description: Number of send/receive tasks that scattered algorithm
waits for completion before posting another batch of send/receives
of that size
Default: 4
MPIR_CVAR_DEVICE_COLLECTIVES
Aliases: MPIR_PARAM_DEVICE_COLLECTIVES
MPICH_DEVICE_COLLECTIVES
Description: Variable to select whether the device can override the
MPIR-level collective algorithms.
all - Always prefer the device collectives
none - Never pick the device collectives
percoll - Use the per-collective CVARs to decide
Default: MPIR_CVAR_DEVICE_COLLECTIVES_percoll
MPIR_CVAR_COLLECTIVE_FALLBACK
Aliases: MPIR_PARAM_COLLECTIVE_FALLBACK
MPICH_COLLECTIVE_FALLBACK
Description: Variable to control what the MPI library should do if the
user-specified collective algorithm does not work for the
arguments passed in by the user.
error - throw an error
print - print an error message and fallback to the internally
selected algorithm
silent - silently fallback to the internally selected algorithm
Default: MPIR_CVAR_COLLECTIVE_FALLBACK_silent
MPIR_CVAR_COLL_SELECTION_TUNING_JSON_FILE
Aliases: MPIR_PARAM_COLL_SELECTION_TUNING_JSON_FILE
MPICH_COLL_SELECTION_TUNING_JSON_FILE
Description: Defines the location of tuning file.
Default: ""
MPIR_CVAR_HIERARCHY_DUMP
Aliases: MPIR_PARAM_HIERARCHY_DUMP
MPICH_HIERARCHY_DUMP
Description: If set to true, each rank will dump the hierarchy data
structure to a file named "hierarchy[rank]" in the current folder.
If set to false, the hierarchy data structure will not be dumped.
Default: 0
MPIR_CVAR_COORDINATES_FILE
Aliases: MPIR_PARAM_COORDINATES_FILE
MPICH_COORDINATES_FILE
Description: Defines the location of the input coordinates file.
Default: ""
MPIR_CVAR_COLL_TREE_DUMP
Aliases: MPIR_PARAM_COLL_TREE_DUMP
MPICH_COLL_TREE_DUMP
Description: If set to true, each rank will dump the tree to a file
named "colltree[rank].json" in the current folder. If set to false,
the tree will not be dumped.
Default: 0
MPIR_CVAR_COORDINATES_DUMP
Aliases: MPIR_PARAM_COORDINATES_DUMP
MPICH_COORDINATES_DUMP
Description: If set to true, rank 0 will dump the network coordinates
to a file named "coords" in the current folder. If set to false,
the network coordinates will not be dumped.
Default: 0
MPIR_CVAR_PROGRESS_MAX_COLLS
Aliases: MPIR_PARAM_PROGRESS_MAX_COLLS
MPICH_PROGRESS_MAX_COLLS
Description: Maximum number of collective operations at a time that the
progress engine should make progress on
Default: 0
MPIR_CVAR_COMM_SPLIT_USE_QSORT
Aliases: MPIR_PARAM_COMM_SPLIT_USE_QSORT
MPICH_COMM_SPLIT_USE_QSORT
Description: Use qsort(3) in the implementation of MPI_Comm_split
instead of bubble sort.
Default: 1
MPIR_CVAR_CTXID_EAGER_SIZE
Aliases: MPIR_PARAM_CTXID_EAGER_SIZE
MPICH_CTXID_EAGER_SIZE
Description: The MPIR_CVAR_CTXID_EAGER_SIZE environment variable allows
you to specify how many words in the context ID mask will be set
aside for the eager allocation protocol. If the application is
running out of context IDs, reducing this value may help.
Default: 2
MPIR_CVAR_DATALOOP_FAST_SEEK
Aliases: MPIR_PARAM_DATALOOP_FAST_SEEK
MPICH_DATALOOP_FAST_SEEK
Description: use a datatype-specialized algorithm to shortcut seeking
to the correct location in a noncontiguous buffer
Default: 1
MPIR_CVAR_YAKSA_COMPLEX_SUPPORT
Aliases: MPIR_PARAM_YAKSA_COMPLEX_SUPPORT
MPICH_YAKSA_COMPLEX_SUPPORT
Description: This CVAR indicates that complex type reduction is not
supported in yaksa.
Default: 0
MPIR_CVAR_GPU_DOUBLE_SUPPORT
Aliases: MPIR_PARAM_GPU_DOUBLE_SUPPORT
MPICH_GPU_DOUBLE_SUPPORT
Description: This CVAR indicates that double type is not supported on
the GPU.
Default: 0
MPIR_CVAR_GPU_LONG_DOUBLE_SUPPORT
Aliases: MPIR_PARAM_GPU_LONG_DOUBLE_SUPPORT
MPICH_GPU_LONG_DOUBLE_SUPPORT
Description: This CVAR indicates that double type is not supported on
the GPU.
Default: 0
MPIR_CVAR_ENABLE_YAKSA_REDUCTION
Aliases: MPIR_PARAM_ENABLE_YAKSA_REDUCTION
MPICH_ENABLE_YAKSA_REDUCTION
Description: This cvar enables yaksa based reduction for local reduce.
Default: 1
MPIR_CVAR_YAKSA_REDUCTION_THRESHOLD
Aliases: MPIR_PARAM_YAKSA_REDUCTION_THRESHOLD
MPICH_YAKSA_REDUCTION_THRESHOLD
Description: This cvar disables yaksa based reduction for messages
above the threshold. The default is no limit.
Default: -1
MPIR_CVAR_PROCTABLE_SIZE
Aliases: MPIR_PARAM_PROCTABLE_SIZE
MPICH_PROCTABLE_SIZE
Description: Size of the "MPIR" debugger interface proctable (process
table).
Default: 64
MPIR_CVAR_PROCTABLE_PRINT
Aliases: MPIR_PARAM_PROCTABLE_PRINT
MPICH_PROCTABLE_PRINT
Description: If true, dump the proctable entries at
MPII_Wait_for_debugger-time.
Default: 0
MPIR_CVAR_PRINT_ERROR_STACK
Aliases: MPIR_PARAM_PRINT_ERROR_STACK
MPICH_PRINT_ERROR_STACK
Description: If true, print an error stack trace at error handling
time.
Default: 1
MPIR_CVAR_CHOP_ERROR_STACK
Aliases: MPIR_PARAM_CHOP_ERROR_STACK
MPICH_CHOP_ERROR_STACK
Description: If >0, truncate error stack output lines this many
characters wide. If 0, do not truncate, and if <0 use a sensible
default.
Default: 0
MPIR_CVAR_ASYNC_PROGRESS
Aliases: MPIR_PARAM_ASYNC_PROGRESS
MPICH_ASYNC_PROGRESS
Description: If set to true, MPICH will initiate an additional thread
to make asynchronous progress on all communication operations
including point-to-point, collective, one-sided operations and I/O.
Setting this variable will automatically increase the
thread-safety level to MPI_THREAD_MULTIPLE. While this improves
the progress semantics, it might cause a small amount of
performance overhead for regular MPI operations. The user is
encouraged to leave one or more hardware threads vacant in order to
prevent contention between the application threads and the progress
thread(s). The impact of oversubscription is highly system
dependent but may be substantial in some cases, hence this
recommendation.
Default: 0
MPIR_CVAR_PROGRESS_THREAD_AFFINITY
Aliases: MPIR_PARAM_PROGRESS_THREAD_AFFINITY
MPICH_PROGRESS_THREAD_AFFINITY
Description: Specifies affinity for all progress threads of local
processes. Can be set to auto or comma-separated list of logical
processors. When set to auto - MPICH will automatically select
logical CPU cores to decide affinity of the progress threads. When
set to comma-separated list of logical processors - In case of N
progress threads per process, the first N logical processors from
list will be assigned to threads of first local process, the next N
logical processors from list - to second local process and so on.
For example, thread affinity is "0,1,2,3", 2 progress threads per
process and 2 processes per node. Progress threads of first local
process will be pinned on logical processors "0,1", progress
threads of second local process - on "2,3". Cannot work together
with MPIR_CVAR_NUM_CLIQUES or MPIR_CVAR_ODD_EVEN_CLIQUES.
Default: ""
MPIR_CVAR_SUPPRESS_ABORT_MESSAGE
Aliases: MPIR_PARAM_SUPPRESS_ABORT_MESSAGE
MPICH_SUPPRESS_ABORT_MESSAGE
Description: Disable printing of abort error message.
Default: 0
MPIR_CVAR_COREDUMP_ON_ABORT
Aliases: MPIR_PARAM_COREDUMP_ON_ABORT
MPICH_COREDUMP_ON_ABORT
Description: Call libc abort() to generate a corefile
Default: 0
MPIR_CVAR_ERROR_CHECKING
Aliases: MPIR_PARAM_ERROR_CHECKING
MPICH_ERROR_CHECKING
Description: If true, perform checks for errors, typically to verify
valid inputs to MPI routines. Only effective when MPICH is
configured with --enable-error-checking=runtime .
Default: 1
MPIR_CVAR_MEMDUMP
Aliases: MPIR_PARAM_MEMDUMP
MPICH_MEMDUMP
Description: If true, list any memory that was allocated by MPICH and
that remains allocated when MPI_Finalize completes.
Default: 1
MPIR_CVAR_DEBUG_SUMMARY
Aliases: MPIR_PARAM_DEBUG_SUMMARY
MPICH_DEBUG_SUMMARY
MPIR_CVAR_MEM_CATEGORY_INFORMATION
MPIR_CVAR_CH4_OFI_CAPABILITY_SETS_DEBUG
MPIR_CVAR_CH4_UCX_CAPABILITY_DEBUG
MPIR_PARAM_MEM_CATEGORY_INFORMATION
MPIR_PARAM_CH4_OFI_CAPABILITY_SETS_DEBUG
MPIR_PARAM_CH4_UCX_CAPABILITY_DEBUG
MPICH_MEM_CATEGORY_INFORMATION
MPICH_CH4_OFI_CAPABILITY_SETS_DEBUG
MPICH_CH4_UCX_CAPABILITY_DEBUG
Description: 1: Print internal summary of various debug information,
such as memory allocation by category. Each layer may print their
own summary information. For example, ch4-ofi may print its
provider capability settings. 2: Also print the preferred NIC for
each rank
Default: 0
MPIR_CVAR_DEFAULT_THREAD_LEVEL
Aliases: MPIR_PARAM_DEFAULT_THREAD_LEVEL
MPICH_DEFAULT_THREAD_LEVEL
Description: Sets the default thread level to use when using MPI_INIT.
This variable is case-insensitive.
Default: "MPI_THREAD_SINGLE"
MPIR_CVAR_DEBUG_HOLD
Aliases: MPIR_PARAM_DEBUG_HOLD
MPICH_DEBUG_HOLD
Description: If true, causes processes to wait in MPI_Init and
MPI_Initthread for a debugger to be attached. Once the debugger
has attached, the variable 'hold' should be set to 0 in order to
allow the process to continue (e.g., in gdb, "set hold=0").
Default: 0
MPIR_CVAR_GPU_USE_IMMEDIATE_COMMAND_LIST
Aliases: MPIR_PARAM_GPU_USE_IMMEDIATE_COMMAND_LIST
MPICH_GPU_USE_IMMEDIATE_COMMAND_LIST
Description: If true, mpl/ze will use immediate command list for
copying
Default: 0
MPIR_CVAR_GPU_ROUND_ROBIN_COMMAND_QUEUES
Aliases: MPIR_PARAM_GPU_ROUND_ROBIN_COMMAND_QUEUES
MPICH_GPU_ROUND_ROBIN_COMMAND_QUEUES
Description: If true, mpl/ze will use command queues in a round-robin
fashion. If false, only command queues of index 0 will be used.
Default: 0
MPIR_CVAR_NO_COLLECTIVE_FINALIZE
Aliases: MPIR_PARAM_NO_COLLECTIVE_FINALIZE
MPICH_NO_COLLECTIVE_FINALIZE
Description: If true, prevent MPI_Finalize to invoke collective
behavior such as barrier or communicating to other processes.
Consequently, it may result in leaking memory or losing messages
due to pre-mature exiting. The default is false, which may invoke
collective behaviors at finalize.
Default: 0
MPIR_CVAR_FINALIZE_WAIT
Aliases: MPIR_PARAM_FINALIZE_WAIT
MPICH_FINALIZE_WAIT
Description: If true, poll progress at MPI_Finalize until reference
count on MPI_COMM_WORLD and MPI_COMM_SELF reaches zero. This may be
necessary to prevent remote processes hanging if it has pending
communication protocols, e.g. a rendezvous send.
Default: 0
MPIR_CVAR_INIT_SKIP_PMI_BARRIER
Aliases: MPIR_PARAM_INIT_SKIP_PMI_BARRIER
MPICH_INIT_SKIP_PMI_BARRIER
Description: Skip MPIR_pmi_barrier() in MPI_Init
Default: 1
MPIR_CVAR_GPU_FAST_COPY_MAX_SIZE
Aliases: MPIR_PARAM_GPU_FAST_COPY_MAX_SIZE
MPICH_GPU_FAST_COPY_MAX_SIZE
Description: If a send message size is less than or equal to
MPIR_CVAR_GPU_FAST_COPY_MAX_SIZE (in bytes), then enable GPU-based
fast memcpy. The environment variable is valid only when then GPU
IPC shmmod is enabled.
Default: 4096
MPIR_CVAR_GPU_FAST_COPY_MAX_SIZE_H2D
Aliases: MPIR_PARAM_GPU_FAST_COPY_MAX_SIZE_H2D
MPICH_GPU_FAST_COPY_MAX_SIZE_H2D
Description: If a receive message size is less than or equal to
MPIR_CVAR_GPU_FAST_COPY_MAX_SIZE_H2D (in bytes), then enable
GPU-based fast memcpy.
Default: 1048576
MPIR_CVAR_GPU_FAST_COPY_MAX_SIZE_D2H
Aliases: MPIR_PARAM_GPU_FAST_COPY_MAX_SIZE_D2H
MPICH_GPU_FAST_COPY_MAX_SIZE_D2H
Description: If a send message size is less than or equal to
MPIR_CVAR_GPU_FAST_COPY_MAX_SIZE_D2H (in bytes), then enable
GPU-based fast memcpy.
Default: 32768
MPIR_CVAR_REQUEST_ERR_FATAL
Aliases: MPIR_PARAM_REQUEST_ERR_FATAL
MPICH_REQUEST_ERR_FATAL
Description: By default, MPI_Waitall, MPI_Testall, MPI_Waitsome, and
MPI_Testsome return MPI_ERR_IN_STATUS when one of the request
fails. If MPIR_CVAR_REQUEST_ERR_FATAL is set to true, these
routines will return the error code of the request immediately. The
default MPI_ERRS_ARE_FATAL error handler will dump a error stack in
this case, which maybe more convenient for debugging. This cvar
will also make nonblocking shched return error right away as it
issues operations.
Default: 0
MPIR_CVAR_REQUEST_POLL_FREQ
Aliases: MPIR_PARAM_REQUEST_POLL_FREQ
MPICH_REQUEST_POLL_FREQ
Description: How frequent to poll during MPI_{Waitany,Waitsome} in
terms of number of processed requests before polling.
Default: 8
MPIR_CVAR_REQUEST_BATCH_SIZE
Aliases: MPIR_PARAM_REQUEST_BATCH_SIZE
MPICH_REQUEST_BATCH_SIZE
Description: The number of requests to make completion as a batch in
MPI_Waitall and MPI_Testall implementation. A large number is
likely to cause more cache misses.
Default: 64
MPIR_CVAR_DEBUG_PROGRESS_TIMEOUT
Aliases: MPIR_PARAM_DEBUG_PROGRESS_TIMEOUT
MPICH_DEBUG_PROGRESS_TIMEOUT
Description: Sets the timeout in seconds to dump outstanding requests
when progress wait is not making progress for some time.
Default: 0
MPIR_CVAR_DIMS_VERBOSE
Aliases: MPIR_PARAM_DIMS_VERBOSE
MPICH_DIMS_VERBOSE
Description: If true, enable verbose output about the actions of the
implementation of MPI_Dims_create.
Default: 0
MPIR_CVAR_QMPI_TOOL_LIST
Aliases: MPIR_PARAM_QMPI_TOOL_LIST
MPICH_QMPI_TOOL_LIST
Description: Set the number and order of QMPI tools to be loaded by the
MPI library when it is initialized.
Default: NULL
MPIR_CVAR_NAMESERV_FILE_PUBDIR
Aliases: MPIR_PARAM_NAMESERV_FILE_PUBDIR
MPICH_NAMESERV_FILE_PUBDIR
MPIR_CVAR_NAMEPUB_DIR
MPIR_PARAM_NAMEPUB_DIR
MPICH_NAMEPUB_DIR
Description: Sets the directory to use for MPI service publishing in
the file nameserv implementation. Allows the user to override
where the publish and lookup information is placed for
connect/accept based applications.
Default: NULL
MPIR_CVAR_ABORT_ON_LEAKED_HANDLES
Aliases: MPIR_PARAM_ABORT_ON_LEAKED_HANDLES
MPICH_ABORT_ON_LEAKED_HANDLES
Description: If true, MPI will call MPI_Abort at MPI_Finalize if any
MPI object handles have been leaked. For example, if MPI_Comm_dup
is called without calling a corresponding MPI_Comm_free. For
uninteresting reasons, enabling this option may prevent all known
object leaks from being reported. MPICH must have been configure
with "--enable-g=handlealloc" or better in order for this
functionality to work.
Default: 0
MPIR_CVAR_NETLOC_NODE_FILE
Aliases: MPIR_PARAM_NETLOC_NODE_FILE
MPICH_NETLOC_NODE_FILE
Description: Subnet json file
Default: "auto"
MPIR_CVAR_NOLOCAL
Aliases: MPIR_PARAM_NOLOCAL
MPICH_NOLOCAL
MPIR_CVAR_NO_LOCAL
MPIR_PARAM_NO_LOCAL
MPICH_NO_LOCAL
Description: If true, force all processes to operate as though all
processes are located on another node. For example, this disables
shared memory communication hierarchical collectives.
Default: 0
MPIR_CVAR_ODD_EVEN_CLIQUES
Aliases: MPIR_PARAM_ODD_EVEN_CLIQUES
MPICH_ODD_EVEN_CLIQUES
MPIR_CVAR_EVEN_ODD_CLIQUES
MPIR_PARAM_EVEN_ODD_CLIQUES
MPICH_EVEN_ODD_CLIQUES
Description: If true, odd procs on a node are seen as local to each
other, and even procs on a node are seen as local to each other.
Used for debugging on a single machine. Deprecated in favor of
MPIR_CVAR_NUM_CLIQUES.
Default: 0
MPIR_CVAR_NUM_CLIQUES
Aliases: MPIR_PARAM_NUM_CLIQUES
MPICH_NUM_CLIQUES
Description: Specify the number of cliques that should be used to
partition procs on a local node. Procs with the same clique number
are seen as local to each other. Used for debugging on a single
machine.
Default: 1
MPIR_CVAR_CLIQUES_BY_BLOCK
Aliases: MPIR_PARAM_CLIQUES_BY_BLOCK
MPICH_CLIQUES_BY_BLOCK
Description: Specify to divide processes into cliques by uniform
blocks. The default is to divide in round-robin fashion. Used for
debugging on a single machine.
Default: 0
MPIR_CVAR_PMI_VERSION
Aliases: MPIR_PARAM_PMI_VERSION
MPICH_PMI_VERSION
Description: Variable to select runtime PMI version.
1 - PMI (default)
2 - PMI2
x - PMIx
Default: MPIR_CVAR_PMI_VERSION_1
MPIR_CVAR_COLL_ALIAS_CHECK
Aliases: MPIR_PARAM_COLL_ALIAS_CHECK
MPICH_COLL_ALIAS_CHECK
Description: Enable checking of aliasing in collective operations
Default: 1
MPIR_CVAR_ENABLE_GPU
Aliases: MPIR_PARAM_ENABLE_GPU
MPICH_ENABLE_GPU
Description: Control MPICH GPU support. If set to 0, all GPU support is
disabled and we do not query the buffer type internally because we
assume no GPU buffer is use.
Default: 1
MPIR_CVAR_GPU_HAS_WAIT_KERNEL
Aliases: MPIR_PARAM_GPU_HAS_WAIT_KERNEL
MPICH_GPU_HAS_WAIT_KERNEL
Description: If set to 1, avoid allocate allocating GPU registered host
buffers for temporary buffers. When stream workq and GPU wait
kernels are in use, access APIs for GPU registered memory may cause
deadlock.
Default: 0
MPIR_CVAR_ENABLE_GPU_REGISTER
Aliases: MPIR_PARAM_ENABLE_GPU_REGISTER
MPICH_ENABLE_GPU_REGISTER
Description: Control whether to actually register buffers with the GPU
runtime in MPIR_gpu_register_host. This could lower the latency of
certain GPU communication at the cost of some amount of GPU memory
consumed by the MPI library. By default, registration is enabled.
Default: 1
MPIR_CVAR_POLLS_BEFORE_YIELD
Aliases: MPIR_PARAM_POLLS_BEFORE_YIELD
MPICH_POLLS_BEFORE_YIELD
Description: When MPICH is in a busy waiting loop, it will periodically
call a function to yield the processor. This cvar sets the number
of loops before the yield function is called. A value of 0
disables yielding.
Default: 1000
MPIR_CVAR_CH3_INTERFACE_HOSTNAME
Aliases: MPIR_PARAM_CH3_INTERFACE_HOSTNAME
MPICH_CH3_INTERFACE_HOSTNAME
MPIR_CVAR_INTERFACE_HOSTNAME
MPIR_PARAM_INTERFACE_HOSTNAME
MPICH_INTERFACE_HOSTNAME
Description: If non-NULL, this cvar specifies the IP address that other
processes should use when connecting to this process. This cvar is
mutually exclusive with the MPIR_CVAR_CH3_NETWORK_IFACE cvar and it
is an error to set them both.
Default: NULL
MPIR_CVAR_CH3_PORT_RANGE
Aliases: MPIR_PARAM_CH3_PORT_RANGE
MPICH_CH3_PORT_RANGE
MPIR_CVAR_PORTRANGE
MPIR_CVAR_PORT_RANGE
MPIR_PARAM_PORTRANGE
MPIR_PARAM_PORT_RANGE
MPICH_PORTRANGE
MPICH_PORT_RANGE
Description: The MPIR_CVAR_CH3_PORT_RANGE environment variable allows
you to specify the range of TCP ports to be used by the process
manager and the MPICH library. The format of this variable is
<low>:<high>. To specify any available port, use 0:0.
Default: {0,0}
MPIR_CVAR_NEMESIS_TCP_NETWORK_IFACE
Aliases: MPIR_PARAM_NEMESIS_TCP_NETWORK_IFACE
MPICH_NEMESIS_TCP_NETWORK_IFACE
MPIR_CVAR_NETWORK_IFACE
MPIR_PARAM_NETWORK_IFACE
MPICH_NETWORK_IFACE
Description: If non-NULL, this cvar specifies which pseudo-ethernet
interface the tcp netmod should use (e.g., "eth1", "ib0"). Note,
this is a Linux-specific cvar. This cvar is mutually exclusive with
the MPIR_CVAR_CH3_INTERFACE_HOSTNAME cvar and it is an error to set
them both.
Default: NULL
MPIR_CVAR_NEMESIS_TCP_HOST_LOOKUP_RETRIES
Aliases: MPIR_PARAM_NEMESIS_TCP_HOST_LOOKUP_RETRIES
MPICH_NEMESIS_TCP_HOST_LOOKUP_RETRIES
Description: This cvar controls the number of times to retry the
gethostbyname() function before giving up.
Default: 10
MPIR_CVAR_NEMESIS_ENABLE_CKPOINT
Aliases: MPIR_PARAM_NEMESIS_ENABLE_CKPOINT
MPICH_NEMESIS_ENABLE_CKPOINT
Description: If true, enables checkpointing support and returns an
error if checkpointing library cannot be initialized.
Default: 0
MPIR_CVAR_NEMESIS_SHM_EAGER_MAX_SZ
Aliases: MPIR_PARAM_NEMESIS_SHM_EAGER_MAX_SZ
MPICH_NEMESIS_SHM_EAGER_MAX_SZ
Description: This cvar controls the message size at which Nemesis
switches from eager to rendezvous mode for shared memory. If this
cvar is set to -1, then Nemesis will choose an appropriate value.
Default: -1
MPIR_CVAR_NEMESIS_SHM_READY_EAGER_MAX_SZ
Aliases: MPIR_PARAM_NEMESIS_SHM_READY_EAGER_MAX_SZ
MPICH_NEMESIS_SHM_READY_EAGER_MAX_SZ
Description: This cvar controls the message size at which Nemesis
switches from eager to rendezvous mode for ready-send messages. If
this cvar is set to -1, then ready messages will always be sent
eagerly. If this cvar is set to -2, then Nemesis will choose an
appropriate value.
Default: -2
MPIR_CVAR_ENABLE_FT
Aliases: MPIR_PARAM_ENABLE_FT
MPICH_ENABLE_FT
Description: Enable fault tolerance functions
Default: 0
MPIR_CVAR_NEMESIS_NETMOD
Aliases: MPIR_PARAM_NEMESIS_NETMOD
MPICH_NEMESIS_NETMOD
Description: If non-empty, this cvar specifies which network module
should be used for communication. This variable is
case-insensitive.
Default: ""
MPIR_CVAR_CH3_ENABLE_HCOLL
Aliases: MPIR_PARAM_CH3_ENABLE_HCOLL
MPICH_CH3_ENABLE_HCOLL
Description: If true, enable HCOLL collectives.
Default: 0
MPIR_CVAR_CH3_COMM_CONNECT_TIMEOUT
Aliases: MPIR_PARAM_CH3_COMM_CONNECT_TIMEOUT
MPICH_CH3_COMM_CONNECT_TIMEOUT
Description: The default time out period in seconds for a connection
attempt to the server communicator where the named port exists but
no pending accept. User can change the value for a specified
connection through its info argument.
Default: 180
MPIR_CVAR_CH3_RMA_OP_PIGGYBACK_LOCK_DATA_SIZE
Aliases: MPIR_PARAM_CH3_RMA_OP_PIGGYBACK_LOCK_DATA_SIZE
MPICH_CH3_RMA_OP_PIGGYBACK_LOCK_DATA_SIZE
Description: Specify the threshold of data size of a RMA operation
which can be piggybacked with a LOCK message. It is always a
positive value and should not be smaller than
MPIDI_RMA_IMMED_BYTES. If user sets it as a small value, for middle
and large data size, we will lose performance because of always
waiting for round-trip of LOCK synchronization; if user sets it as
a large value, we need to consume more memory on target side to
buffer this lock request when lock is not satisfied.
Default: 65536
MPIR_CVAR_CH3_RMA_ACTIVE_REQ_THRESHOLD
Aliases: MPIR_PARAM_CH3_RMA_ACTIVE_REQ_THRESHOLD
MPICH_CH3_RMA_ACTIVE_REQ_THRESHOLD
Description: Threshold of number of active requests to trigger blocking
waiting in operation routines. When the value is negative, we never
blockingly wait in operation routines. When the value is zero, we
always trigger blocking waiting in operation routines to wait until
no. of active requests becomes zero. When the value is positive, we
do blocking waiting in operation routines to wait until no. of
active requests being reduced to this value.
Default: 65536
MPIR_CVAR_CH3_RMA_POKE_PROGRESS_REQ_THRESHOLD
Aliases: MPIR_PARAM_CH3_RMA_POKE_PROGRESS_REQ_THRESHOLD
MPICH_CH3_RMA_POKE_PROGRESS_REQ_THRESHOLD
Description: Threshold at which the RMA implementation attempts to
complete requests while completing RMA operations and while using
the lazy synchronization approach. Change this value if programs
fail because they run out of requests or other internal resources
Default: 128
MPIR_CVAR_CH3_RMA_SCALABLE_FENCE_PROCESS_NUM
Aliases: MPIR_PARAM_CH3_RMA_SCALABLE_FENCE_PROCESS_NUM
MPICH_CH3_RMA_SCALABLE_FENCE_PROCESS_NUM
Description: Specify the threshold of switching the algorithm used in
FENCE from the basic algorithm to the scalable algorithm. The value
can be negative, zero or positive. When the number of processes is
larger than or equal to this value, FENCE will use a scalable
algorithm which do not use O(P) data structure; when the number of
processes is smaller than the value, FENCE will use a basic but
fast algorithm which requires an O(P) data structure.
Default: 1024
MPIR_CVAR_CH3_RMA_DELAY_ISSUING_FOR_PIGGYBACKING
Aliases: MPIR_PARAM_CH3_RMA_DELAY_ISSUING_FOR_PIGGYBACKING
MPICH_CH3_RMA_DELAY_ISSUING_FOR_PIGGYBACKING
Description: Specify if delay issuing of RMA operations for
piggybacking LOCK/UNLOCK/FLUSH is enabled. It can be either 0 or 1.
When it is set to 1, the issuing of LOCK message is delayed until
origin process see the first RMA operation and piggyback LOCK with
that operation, and the origin process always keeps the current
last operation until the ending synchronization call in order to
piggyback UNLOCK/FLUSH with that operation. When it is set to 0, in
WIN_LOCK/UNLOCK case, the LOCK message is sent out as early as
possible, in WIN_LOCK_ALL/UNLOCK_ALL case, the origin process still
tries to piggyback LOCK message with the first operation; for
UNLOCK/FLUSH message, the origin process no longer keeps the
current last operation but only piggyback UNLOCK/FLUSH if there is
an operation available in the ending synchronization call.
Default: 0
MPIR_CVAR_CH3_RMA_SLOTS_SIZE
Aliases: MPIR_PARAM_CH3_RMA_SLOTS_SIZE
MPICH_CH3_RMA_SLOTS_SIZE
Description: Number of RMA slots during window creation. Each slot
contains a linked list of target elements. The distribution of
ranks among slots follows a round-robin pattern. Requires a
positive value.
Default: 262144
MPIR_CVAR_CH3_RMA_TARGET_LOCK_DATA_BYTES
Aliases: MPIR_PARAM_CH3_RMA_TARGET_LOCK_DATA_BYTES
MPICH_CH3_RMA_TARGET_LOCK_DATA_BYTES
Description: Size (in bytes) of available lock data this window can
provided. If current buffered lock data is more than this value,
the process will drop the upcoming operation data. Requires a
positive value.
Default: 655360
MPIR_CVAR_CH3_EAGER_MAX_MSG_SIZE
Aliases: MPIR_PARAM_CH3_EAGER_MAX_MSG_SIZE
MPICH_CH3_EAGER_MAX_MSG_SIZE
Description: This cvar controls the message size at which CH3 switches
from eager to rendezvous mode.
Default: 131072
MPIR_CVAR_CH3_PG_VERBOSE
Aliases: MPIR_PARAM_CH3_PG_VERBOSE
MPICH_CH3_PG_VERBOSE
Description: If set, print the PG state on finalize.
Default: 0
MPIR_CVAR_CH3_RMA_OP_WIN_POOL_SIZE
Aliases: MPIR_PARAM_CH3_RMA_OP_WIN_POOL_SIZE
MPICH_CH3_RMA_OP_WIN_POOL_SIZE
Description: Size of the window-private RMA operations pool (in number
of operations) that stores information about RMA operations that
could not be issued immediately. Requires a positive value.
Default: 256
MPIR_CVAR_CH3_RMA_OP_GLOBAL_POOL_SIZE
Aliases: MPIR_PARAM_CH3_RMA_OP_GLOBAL_POOL_SIZE
MPICH_CH3_RMA_OP_GLOBAL_POOL_SIZE
Description: Size of the Global RMA operations pool (in number of
operations) that stores information about RMA operations that could
not be issued immediately. Requires a positive value.
Default: 16384
MPIR_CVAR_CH3_RMA_TARGET_WIN_POOL_SIZE
Aliases: MPIR_PARAM_CH3_RMA_TARGET_WIN_POOL_SIZE
MPICH_CH3_RMA_TARGET_WIN_POOL_SIZE
Description: Size of the window-private RMA target pool (in number of
targets) that stores information about RMA targets that could not
be issued immediately. Requires a positive value.
Default: 256
MPIR_CVAR_CH3_RMA_TARGET_GLOBAL_POOL_SIZE
Aliases: MPIR_PARAM_CH3_RMA_TARGET_GLOBAL_POOL_SIZE
MPICH_CH3_RMA_TARGET_GLOBAL_POOL_SIZE
Description: Size of the Global RMA targets pool (in number of targets)
that stores information about RMA targets that could not be issued
immediately. Requires a positive value.
Default: 16384
MPIR_CVAR_CH3_RMA_TARGET_LOCK_ENTRY_WIN_POOL_SIZE
Aliases: MPIR_PARAM_CH3_RMA_TARGET_LOCK_ENTRY_WIN_POOL_SIZE
MPICH_CH3_RMA_TARGET_LOCK_ENTRY_WIN_POOL_SIZE
Description: Size of the window-private RMA lock entries pool (in
number of lock entries) that stores information about RMA lock
requests that could not be satisfied immediately. Requires a
positive value.
Default: 256
MPIR_CVAR_OFI_USE_PROVIDER
Aliases: MPIR_PARAM_OFI_USE_PROVIDER
MPICH_OFI_USE_PROVIDER
Description: This variable is no longer supported. Use FI_PROVIDER
instead to select libfabric providers.
Default: NULL
MPIR_CVAR_SINGLE_HOST_ENABLED
Aliases: MPIR_PARAM_SINGLE_HOST_ENABLED
MPICH_SINGLE_HOST_ENABLED
Description: Set this variable to true to indicate that processes are
launched on a single host. The current implication is to avoid the
cxi provider to prevent the use of scarce hardware resources.
Default: 1
MPIR_CVAR_CH4_OFI_AM_LONG_FORCE_PIPELINE
Aliases: MPIR_PARAM_CH4_OFI_AM_LONG_FORCE_PIPELINE
MPICH_CH4_OFI_AM_LONG_FORCE_PIPELINE
Description: For long message to be sent using pipeline rather than
default RDMA read.
Default: 0
MPIR_CVAR_BCAST_OFI_INTRA_ALGORITHM
Aliases: MPIR_PARAM_BCAST_OFI_INTRA_ALGORITHM
MPICH_BCAST_OFI_INTRA_ALGORITHM
Description: Variable to select algorithm for intra-node bcast
mpir - Fallback to MPIR collectives
trigger_tree_tagged - Force triggered ops based Tagged Tree
trigger_tree_rma - Force triggered ops based RMA Tree
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_CH4_OFI_COLL_SELECTION_TUNING_JSON_FILE)
Default: MPIR_CVAR_BCAST_OFI_INTRA_ALGORITHM_auto
MPIR_CVAR_CH4_OFI_GPU_RECEIVE_ENGINE_TYPE
Aliases: MPIR_PARAM_CH4_OFI_GPU_RECEIVE_ENGINE_TYPE
MPICH_CH4_OFI_GPU_RECEIVE_ENGINE_TYPE
Description: Specifies GPU engine type for GPU pt2pt on the receiver
side.
compute - use a compute engine
copy_high_bandwidth - use a high-bandwidth copy engine
copy_low_latency - use a low-latency copy engine
yaksa - use Yaksa
Default: MPIR_CVAR_CH4_OFI_GPU_RECEIVE_ENGINE_TYPE_copy_low_latency
MPIR_CVAR_OFI_SKIP_IPV6
Aliases: MPIR_PARAM_OFI_SKIP_IPV6
MPICH_OFI_SKIP_IPV6
Description: Skip IPv6 providers.
Default: 0
MPIR_CVAR_CH4_OFI_ENABLE_DATA
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_DATA
MPICH_CH4_OFI_ENABLE_DATA
Description: Enable immediate data fields in OFI to transmit source
rank outside of the match bits
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_AV_TABLE
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_AV_TABLE
MPICH_CH4_OFI_ENABLE_AV_TABLE
Description: If true, the OFI addressing information will be stored
with an FI_AV_TABLE. If false, an FI_AV_MAP will be used.
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_SCALABLE_ENDPOINTS
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_SCALABLE_ENDPOINTS
MPICH_CH4_OFI_ENABLE_SCALABLE_ENDPOINTS
Description: If true, use OFI scalable endpoints.
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_SHARED_CONTEXTS
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_SHARED_CONTEXTS
MPICH_CH4_OFI_ENABLE_SHARED_CONTEXTS
Description: If set to false (zero), MPICH does not use OFI shared
contexts. If set to -1, it is determined by the OFI capability sets
based on the provider. Otherwise, MPICH tries to use OFI shared
contexts. If they are unavailable, it'll fall back to the mode
without shared contexts.
Default: 0
MPIR_CVAR_CH4_OFI_ENABLE_MR_VIRT_ADDRESS
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_MR_VIRT_ADDRESS
MPICH_CH4_OFI_ENABLE_MR_VIRT_ADDRESS
Description: If true, enable virtual addressing for OFI memory regions.
This variable is only meaningful for OFI versions 1.5+. It is
equivalent to using FI_MR_BASIC in versions of OFI older than 1.5.
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_MR_ALLOCATED
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_MR_ALLOCATED
MPICH_CH4_OFI_ENABLE_MR_ALLOCATED
Description: If true, require all OFI memory regions must be backed by
physical memory pages at the time the registration call is made.
This variable is only meaningful for OFI versions 1.5+. It is
equivalent to using FI_MR_BASIC in versions of OFI older than 1.5.
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_MR_REGISTER_NULL
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_MR_REGISTER_NULL
MPICH_CH4_OFI_ENABLE_MR_REGISTER_NULL
Description: If true, memory registration call supports registering
with NULL addresses.
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_MR_PROV_KEY
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_MR_PROV_KEY
MPICH_CH4_OFI_ENABLE_MR_PROV_KEY
Description: If true, enable provider supplied key for OFI memory
regions. This variable is only meaningful for OFI versions 1.5+. It
is equivalent to using FI_MR_BASIC in versions of OFI older than
1.5.
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_TAGGED
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_TAGGED
MPICH_CH4_OFI_ENABLE_TAGGED
Description: If true, use tagged message transmission functions in OFI.
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_AM
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_AM
MPICH_CH4_OFI_ENABLE_AM
Description: If true, enable OFI active message support.
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_RMA
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_RMA
MPICH_CH4_OFI_ENABLE_RMA
Description: If true, enable OFI RMA support for MPI RMA operations.
OFI support for basic RMA is always required to implement large
messgage transfers in the active message code path.
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_ATOMICS
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_ATOMICS
MPICH_CH4_OFI_ENABLE_ATOMICS
Description: If true, enable OFI Atomics support.
Default: -1
MPIR_CVAR_CH4_OFI_FETCH_ATOMIC_IOVECS
Aliases: MPIR_PARAM_CH4_OFI_FETCH_ATOMIC_IOVECS
MPICH_CH4_OFI_FETCH_ATOMIC_IOVECS
Description: Specifies the maximum number of iovecs that can be used by
the OFI provider for fetch_atomic operations. The default value is
-1, indicating that no value is set.
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_DATA_AUTO_PROGRESS
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_DATA_AUTO_PROGRESS
MPICH_CH4_OFI_ENABLE_DATA_AUTO_PROGRESS
Description: If true, enable MPI data auto progress.
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_CONTROL_AUTO_PROGRESS
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_CONTROL_AUTO_PROGRESS
MPICH_CH4_OFI_ENABLE_CONTROL_AUTO_PROGRESS
Description: If true, enable MPI control auto progress.
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_PT2PT_NOPACK
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_PT2PT_NOPACK
MPICH_CH4_OFI_ENABLE_PT2PT_NOPACK
Description: If true, enable iovec for pt2pt.
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_HMEM
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_HMEM
MPICH_CH4_OFI_ENABLE_HMEM
Description: If true, uses GPU direct RDMA support in the provider.
Default: 0
MPIR_CVAR_CH4_OFI_ENABLE_MR_HMEM
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_MR_HMEM
MPICH_CH4_OFI_ENABLE_MR_HMEM
Description: If true, need to register the buffer to use GPU direct
RDMA.
Default: -1
MPIR_CVAR_CH4_OFI_GPU_RDMA_THRESHOLD
Aliases: MPIR_PARAM_CH4_OFI_GPU_RDMA_THRESHOLD
MPICH_CH4_OFI_GPU_RDMA_THRESHOLD
Description: The threshold to start using GPU direct RDMA.
Default: 0
MPIR_CVAR_CH4_OFI_CONTEXT_ID_BITS
Aliases: MPIR_PARAM_CH4_OFI_CONTEXT_ID_BITS
MPICH_CH4_OFI_CONTEXT_ID_BITS
Description: Specifies the number of bits that will be used for
matching the context ID. The default value is -1, indicating that
no value is set and that the default will be defined in the
ofi_types.h file.
Default: -1
MPIR_CVAR_CH4_OFI_RANK_BITS
Aliases: MPIR_PARAM_CH4_OFI_RANK_BITS
MPICH_CH4_OFI_RANK_BITS
Description: Specifies the number of bits that will be used for
matching the MPI rank. The default value is -1, indicating that no
value is set and that the default will be defined in the
ofi_types.h file.
Default: -1
MPIR_CVAR_CH4_OFI_TAG_BITS
Aliases: MPIR_PARAM_CH4_OFI_TAG_BITS
MPICH_CH4_OFI_TAG_BITS
Description: Specifies the number of bits that will be used for
matching the user tag. The default value is -1, indicating that no
value is set and that the default will be defined in the
ofi_types.h file.
Default: -1
MPIR_CVAR_CH4_OFI_MAJOR_VERSION
Aliases: MPIR_PARAM_CH4_OFI_MAJOR_VERSION
MPICH_CH4_OFI_MAJOR_VERSION
Description: Specifies the major version of the OFI library. The
default is the major version of the OFI library used with MPICH. If
using this CVAR, it is recommended that the user also specifies a
specific OFI provider.
Default: -1
MPIR_CVAR_CH4_OFI_MINOR_VERSION
Aliases: MPIR_PARAM_CH4_OFI_MINOR_VERSION
MPICH_CH4_OFI_MINOR_VERSION
Description: Specifies the major version of the OFI library. The
default is the minor version of the OFI library used with MPICH. If
using this CVAR, it is recommended that the user also specifies a
specific OFI provider.
Default: -1
MPIR_CVAR_CH4_OFI_MAX_RMA_SEP_CTX
Aliases: MPIR_PARAM_CH4_OFI_MAX_RMA_SEP_CTX
MPICH_CH4_OFI_MAX_RMA_SEP_CTX
Description: If set to positive, this CVAR specifies the maximum number
of transmit contexts RMA can utilize in a scalable endpoint. This
value is effective only when scalable endpoint is available,
otherwise it will be ignored.
Default: 0
MPIR_CVAR_CH4_OFI_MAX_EAGAIN_RETRY
Aliases: MPIR_PARAM_CH4_OFI_MAX_EAGAIN_RETRY
MPICH_CH4_OFI_MAX_EAGAIN_RETRY
Description: If set to positive, this CVAR specifies the maximum number
of retries of an ofi operations before returning MPIX_ERR_EAGAIN.
This value is effective only when the communicator has the
MPI_OFI_set_eagain info hint set to true.
Default: -1
MPIR_CVAR_CH4_OFI_NUM_AM_BUFFERS
Aliases: MPIR_PARAM_CH4_OFI_NUM_AM_BUFFERS
MPICH_CH4_OFI_NUM_AM_BUFFERS
Description: Specifies the number of buffers for receiving active
messages.
Default: -1
MPIR_CVAR_CH4_OFI_NUM_OPTIMIZED_MEMORY_REGIONS
Aliases: MPIR_PARAM_CH4_OFI_NUM_OPTIMIZED_MEMORY_REGIONS
MPICH_CH4_OFI_NUM_OPTIMIZED_MEMORY_REGIONS
Description: Specifies the number of optimized memory regions supported
by the provider. An optimized memory region is used for
lower-overhead, unordered RMA operations. It uses a low-overhead RX
path and additionally, a low-overhead packet format may be used to
target an optimized memory region.
Default: 0
MPIR_CVAR_CH4_OFI_RMA_PROGRESS_INTERVAL
Aliases: MPIR_PARAM_CH4_OFI_RMA_PROGRESS_INTERVAL
MPICH_CH4_OFI_RMA_PROGRESS_INTERVAL
Description: Specifies the interval for manually flushing RMA
operations when automatic progress is not enabled. It the
underlying OFI provider supports auto data progress, this value is
ignored. If the value is -1, this optimization will be turned off.
Default: 100
MPIR_CVAR_CH4_OFI_RMA_IOVEC_MAX
Aliases: MPIR_PARAM_CH4_OFI_RMA_IOVEC_MAX
MPICH_CH4_OFI_RMA_IOVEC_MAX
Description: Specifies the maximum number of iovecs to allocate for RMA
operations to/from noncontiguous buffers.
Default: 16384
MPIR_CVAR_CH4_OFI_EAGER_MAX_MSG_SIZE
Aliases: MPIR_PARAM_CH4_OFI_EAGER_MAX_MSG_SIZE
MPICH_CH4_OFI_EAGER_MAX_MSG_SIZE
Description: This cvar controls the message size at which OFI native
path switches from eager to rendezvous mode. It does not affect the
AM path eager limit. Having this gives a way to reliably test
native non-path. If the number is positive, OFI will init the
MPIDI_OFI_global.max_msg_size to the value of cvar. If the number
is negative, OFI will init the MPIDI_OFI_globa.max_msg_size using
whatever provider gives (which might be unlimited for socket
provider).
Default: -1
MPIR_CVAR_CH4_OFI_MAX_NICS
Aliases: MPIR_PARAM_CH4_OFI_MAX_NICS
MPICH_CH4_OFI_MAX_NICS
Description: If set to positive number, this cvar determines the
maximum number of physical nics to use (if more than one is
available). If the number is -1, underlying netmod or shmmod
automatically uses an optimal number depending on what is detected
on the system up to the limit determined by MPIDI_MAX_NICS (in
ofi_types.h).
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_MULTI_NIC_STRIPING
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_MULTI_NIC_STRIPING
MPICH_CH4_OFI_ENABLE_MULTI_NIC_STRIPING
Description: If true, this cvar enables striping of large messages
across multiple NICs.
Default: 0
MPIR_CVAR_CH4_OFI_MULTI_NIC_STRIPING_THRESHOLD
Aliases: MPIR_PARAM_CH4_OFI_MULTI_NIC_STRIPING_THRESHOLD
MPICH_CH4_OFI_MULTI_NIC_STRIPING_THRESHOLD
Description: Striping will happen for message sizes beyond this
threshold.
Default: 1048576
MPIR_CVAR_CH4_OFI_ENABLE_MULTI_NIC_HASHING
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_MULTI_NIC_HASHING
MPICH_CH4_OFI_ENABLE_MULTI_NIC_HASHING
Description: Multi-NIC hashing means to use more than one NIC to send
and receive messages above a certain size. If set to positive
number, this feature will be turned on. If set to 0, this feature
will be turned off. If the number is -1, MPICH automatically
determines whether to use multi-nic hashing depending on what is
detected on the system (e.g., number of NICs available, number of
processes sharing the NICs).
Default: 0
MPIR_CVAR_CH4_OFI_MULTIRECV_BUFFER_SIZE
Aliases: MPIR_PARAM_CH4_OFI_MULTIRECV_BUFFER_SIZE
MPICH_CH4_OFI_MULTIRECV_BUFFER_SIZE
Description: Controls the multirecv am buffer size. It is recommended
to match this to the hugepage size so that the buffer can be
allocated at the page boundary.
Default: 2097152
MPIR_CVAR_OFI_USE_MIN_NICS
Aliases: MPIR_PARAM_OFI_USE_MIN_NICS
MPICH_OFI_USE_MIN_NICS
Description: If true and all nodes do not have the same number of NICs,
MPICH will fall back to using the fewest number of NICs instead of
returning an error.
Default: 1
MPIR_CVAR_CH4_OFI_ENABLE_TRIGGERED
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_TRIGGERED
MPICH_CH4_OFI_ENABLE_TRIGGERED
Description: If true, enable OFI triggered ops for MPI collectives.
Default: -1
MPIR_CVAR_CH4_OFI_ENABLE_GPU_PIPELINE
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_GPU_PIPELINE
MPICH_CH4_OFI_ENABLE_GPU_PIPELINE
Description: If true, enable pipeline for GPU data transfer. GPU
pipeline does not support non-contiguous datatypes or mixed buffer
types (i.e. GPU send buffer, host recv buffer). If GPU pipeline is
enabled, the unsupported scenarios will cause undefined behavior if
encountered.
Default: 0
MPIR_CVAR_CH4_OFI_GPU_PIPELINE_THRESHOLD
Aliases: MPIR_PARAM_CH4_OFI_GPU_PIPELINE_THRESHOLD
MPICH_CH4_OFI_GPU_PIPELINE_THRESHOLD
Description: This is the threshold to start using GPU pipeline.
Default: 131072
MPIR_CVAR_CH4_OFI_GPU_PIPELINE_BUFFER_SZ
Aliases: MPIR_PARAM_CH4_OFI_GPU_PIPELINE_BUFFER_SZ
MPICH_CH4_OFI_GPU_PIPELINE_BUFFER_SZ
Description: Specifies the buffer size (in bytes) for GPU pipeline data
transfer.
Default: 1048576
MPIR_CVAR_CH4_OFI_GPU_PIPELINE_NUM_BUFFERS_PER_CHUNK
Aliases: MPIR_PARAM_CH4_OFI_GPU_PIPELINE_NUM_BUFFERS_PER_CHUNK
MPICH_CH4_OFI_GPU_PIPELINE_NUM_BUFFERS_PER_CHUNK
Description: Specifies the number of buffers for GPU pipeline data
transfer in each block/chunk of the pool.
Default: 32
MPIR_CVAR_CH4_OFI_GPU_PIPELINE_MAX_NUM_BUFFERS
Aliases: MPIR_PARAM_CH4_OFI_GPU_PIPELINE_MAX_NUM_BUFFERS
MPICH_CH4_OFI_GPU_PIPELINE_MAX_NUM_BUFFERS
Description: Specifies the total number of buffers for GPU pipeline
data transfer
Default: 32
MPIR_CVAR_CH4_OFI_GPU_PIPELINE_D2H_ENGINE_TYPE
Aliases: MPIR_PARAM_CH4_OFI_GPU_PIPELINE_D2H_ENGINE_TYPE
MPICH_CH4_OFI_GPU_PIPELINE_D2H_ENGINE_TYPE
Description: Specifies the GPU engine type for GPU pipeline on the
sender side, default is MPL_GPU_ENGINE_TYPE_COMPUTE
Default: 0
MPIR_CVAR_CH4_OFI_GPU_PIPELINE_H2D_ENGINE_TYPE
Aliases: MPIR_PARAM_CH4_OFI_GPU_PIPELINE_H2D_ENGINE_TYPE
MPICH_CH4_OFI_GPU_PIPELINE_H2D_ENGINE_TYPE
Description: Specifies the GPU engine type for GPU pipeline on the
receiver side, default is MPL_GPU_ENGINE_TYPE_COMPUTE
Default: 0
MPIR_CVAR_CH4_OFI_PREF_NIC
Aliases: MPIR_PARAM_CH4_OFI_PREF_NIC
MPICH_CH4_OFI_PREF_NIC
Description: Accept the NIC value from a user
Default: -1
MPIR_CVAR_CH4_OFI_DISABLE_INJECT_WRITE
Aliases: MPIR_PARAM_CH4_OFI_DISABLE_INJECT_WRITE
MPICH_CH4_OFI_DISABLE_INJECT_WRITE
Description: Avoid use fi_inject_write. For some provider, e.g.
tcp;ofi_rxm, inject write may break the synchronization.
Default: 0
MPIR_CVAR_CH4_OFI_ENABLE_INJECT
Aliases: MPIR_PARAM_CH4_OFI_ENABLE_INJECT
MPICH_CH4_OFI_ENABLE_INJECT
Description: Set MPIR_CVAR_CH4_OFI_ENABLE_INJECT=0 to disable buffered
send for small messages. This may help avoid hang due to lack of
global progress.
Default: 1
MPIR_CVAR_CH4_OFI_GPU_SEND_ENGINE_TYPE
Aliases: MPIR_PARAM_CH4_OFI_GPU_SEND_ENGINE_TYPE
MPICH_CH4_OFI_GPU_SEND_ENGINE_TYPE
Description: Specifies GPU engine type for GPU pt2pt on the sender
side.
compute - use a compute engine
copy_high_bandwidth - use a high-bandwidth copy engine
copy_low_latency - use a low-latency copy engine
yaksa - use Yaksa
Default: MPIR_CVAR_CH4_OFI_GPU_SEND_ENGINE_TYPE_copy_low_latency
MPIR_CVAR_CH4_OFI_EAGER_THRESHOLD
Aliases: MPIR_PARAM_CH4_OFI_EAGER_THRESHOLD
MPICH_CH4_OFI_EAGER_THRESHOLD
Description: Messages below MPIR_CVAR_CH4_OFI_EAGER_THRESHOLD will be
sent eagerly using fi_tagged interfaces. Messages above the
threshold will perform an MPICH-level rendezvous handshake before
sending the data. If set to -1, MPICH will only perform rendezvous
for messages larger than the provider max_msg_size. Note the MPICH
eager/rendezvous threshold is independent of any internal libfabric
provider threshold.
Default: -1
MPIR_CVAR_UCX_DT_RECV
Aliases: MPIR_PARAM_UCX_DT_RECV
MPICH_UCX_DT_RECV
Description: Variable to select method for receiving noncontiguous data
true - Use UCX datatype with pack/unpack callbacks
false - MPICH will decide to pack/unpack at
completion or use IOVs
based on the datatype
Default: 0
MPIR_CVAR_CH4_CMA_ENABLE
Aliases: MPIR_PARAM_CH4_CMA_ENABLE
MPICH_CH4_CMA_ENABLE
Description: Set to 1 to manually enable CMA. It is disabled by default
because the CMA requires the ptrace_scope permission, which is
often disabled.
Default: 0
MPIR_CVAR_CH4_IPC_CMA_P2P_THRESHOLD
Aliases: MPIR_PARAM_CH4_IPC_CMA_P2P_THRESHOLD
MPICH_CH4_IPC_CMA_P2P_THRESHOLD
Description: If a send message size is greater than or equal to
MPIR_CVAR_CH4_IPC_CMA_P2P_THRESHOLD (in bytes), then enable
CMA-based single copy protocol for intranode communication. The
environment variable is valid only when the CMA submodule is
enabled.
Default: 16384
MPIR_CVAR_CH4_IPC_GPU_HANDLE_CACHE
Aliases: MPIR_PARAM_CH4_IPC_GPU_HANDLE_CACHE
MPICH_CH4_IPC_GPU_HANDLE_CACHE
Description: By default, we will cache ipc handles using the
specialized cache mechanism. If the
gpu-specific backend does not implement a specialized cache, then
we will fallback to
the generic cache mechanism. Users can optionally force the generic
cache mechanism or
disable ipc caching entirely.
generic - use the cache mechanism in the generic layer
specialized - use the cache mechanism in a gpu-specific mpl layer
(if applicable)
disabled - disable caching completely
Default: MPIR_CVAR_CH4_IPC_GPU_HANDLE_CACHE_specialized
MPIR_CVAR_CH4_IPC_GPU_MAX_CACHE_ENTRIES
Aliases: MPIR_PARAM_CH4_IPC_GPU_MAX_CACHE_ENTRIES
MPICH_CH4_IPC_GPU_MAX_CACHE_ENTRIES
Description: The maximum number of entries to hold per device in the
cache containing IPC mapped buffers. When an entry is evicted, the
corresponding IPC handle is closed. This value is relevant only
when MPIR_CVAR_CH4_IPC_GPU_CACHE_SIZE=limited.
Default: 16
MPIR_CVAR_CH4_IPC_GPU_CACHE_SIZE
Aliases: MPIR_PARAM_CH4_IPC_GPU_CACHE_SIZE
MPICH_CH4_IPC_GPU_CACHE_SIZE
Description: The behavior of the cache containing IPC mapped buffers.
unlimited - don't restrict the cache size
limited - limit the cache size based on
MPIR_CVAR_CH4_IPC_GPU_MAX_CACHE_ENTRIES
disabled - don't cache mapped IPC buffers
Default: MPIR_CVAR_CH4_IPC_GPU_CACHE_SIZE_limited
MPIR_CVAR_CH4_IPC_GPU_P2P_THRESHOLD
Aliases: MPIR_PARAM_CH4_IPC_GPU_P2P_THRESHOLD
MPICH_CH4_IPC_GPU_P2P_THRESHOLD
Description: If a send message size is greater than or equal to
MPIR_CVAR_CH4_IPC_GPU_P2P_THRESHOLD (in bytes), then enable
GPU-based single copy protocol for intranode communication. The
environment variable is valid only when then GPU IPC shmmod is
enabled.
Default: 1048576
MPIR_CVAR_CH4_IPC_ZE_SHAREABLE_HANDLE
Aliases: MPIR_PARAM_CH4_IPC_ZE_SHAREABLE_HANDLE
MPICH_CH4_IPC_ZE_SHAREABLE_HANDLE
Description: Variable to select implementation for ZE shareable IPC
handle
pidfd - use pidfd_getfd syscall to implement shareable IPC handle
drmfd - force to use device fd-based shareable IPC handle
Default: MPIR_CVAR_CH4_IPC_ZE_SHAREABLE_HANDLE_drmfd
MPIR_CVAR_CH4_IPC_GPU_ENGINE_TYPE
Aliases: MPIR_PARAM_CH4_IPC_GPU_ENGINE_TYPE
MPICH_CH4_IPC_GPU_ENGINE_TYPE
Description: By default, select engine type automatically
auto - select automatically
compute - use compute engine
copy_high_bandwidth - use high-bandwidth copy engine
copy_low_latency - use low-latency copy engine
Default: MPIR_CVAR_CH4_IPC_GPU_ENGINE_TYPE_auto
MPIR_CVAR_CH4_IPC_GPU_READ_WRITE_PROTOCOL
Aliases: MPIR_PARAM_CH4_IPC_GPU_READ_WRITE_PROTOCOL
MPICH_CH4_IPC_GPU_READ_WRITE_PROTOCOL
Description: By default, use read protocol.
auto - select automatically
read - use read protocol
write - use write protocol if remote device is visible
Default: MPIR_CVAR_CH4_IPC_GPU_READ_WRITE_PROTOCOL_read
MPIR_CVAR_CH4_IPC_GPU_RMA_ENGINE_TYPE
Aliases: MPIR_PARAM_CH4_IPC_GPU_RMA_ENGINE_TYPE
MPICH_CH4_IPC_GPU_RMA_ENGINE_TYPE
Description: By default, select engine type automatically
yaksa - don't select, use yaksa
auto - select automatically
compute - use compute engine
copy_high_bandwidth - use high-bandwidth copy engine
copy_low_latency - use low-latency copy engine
Default: MPIR_CVAR_CH4_IPC_GPU_RMA_ENGINE_TYPE_auto
MPIR_CVAR_CH4_IPC_MAP_REPEAT_ADDR
Aliases: MPIR_PARAM_CH4_IPC_MAP_REPEAT_ADDR
MPICH_CH4_IPC_MAP_REPEAT_ADDR
Description: If an address is used more than once in the last ten send
operations, map it for IPC use even if it is below the IPC
threshold.
Default: 1
MPIR_CVAR_CH4_XPMEM_ENABLE
Aliases: MPIR_PARAM_CH4_XPMEM_ENABLE
MPICH_CH4_XPMEM_ENABLE
Description: To manually disable XPMEM set to 0. The environment
variable is valid only when the XPMEM submodule is enabled.
Default: 1
MPIR_CVAR_CH4_IPC_XPMEM_P2P_THRESHOLD
Aliases: MPIR_PARAM_CH4_IPC_XPMEM_P2P_THRESHOLD
MPICH_CH4_IPC_XPMEM_P2P_THRESHOLD
Description: If a send message size is greater than or equal to
MPIR_CVAR_CH4_IPC_XPMEM_P2P_THRESHOLD (in bytes), then enable
XPMEM-based single copy protocol for intranode communication. The
environment variable is valid only when the XPMEM submodule is
enabled.
Default: 1024
MPIR_CVAR_BCAST_POSIX_INTRA_ALGORITHM
Aliases: MPIR_PARAM_BCAST_POSIX_INTRA_ALGORITHM
MPICH_BCAST_POSIX_INTRA_ALGORITHM
Description: Variable to select algorithm for intra-node bcast
mpir - Fallback to MPIR collectives
release_gather - Force shm optimized algo using release, gather
primitives
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_CH4_POSIX_COLL_SELECTION_TUNING_JSON_FILE)
ipc_read - Uses read-based collective with ipc
Default: MPIR_CVAR_BCAST_POSIX_INTRA_ALGORITHM_auto
MPIR_CVAR_IBCAST_POSIX_INTRA_ALGORITHM
Aliases: MPIR_PARAM_IBCAST_POSIX_INTRA_ALGORITHM
MPICH_IBCAST_POSIX_INTRA_ALGORITHM
Description: Variable to select algorithm for intra-node bcast
mpir - Fallback to MPIR collectives
release_gather - Force shm optimized algo using release, gather
primitives
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_CH4_POSIX_COLL_SELECTION_TUNING_JSON_FILE)
Default: MPIR_CVAR_IBCAST_POSIX_INTRA_ALGORITHM_auto
MPIR_CVAR_REDUCE_POSIX_INTRA_ALGORITHM
Aliases: MPIR_PARAM_REDUCE_POSIX_INTRA_ALGORITHM
MPICH_REDUCE_POSIX_INTRA_ALGORITHM
Description: Variable to select algorithm for intra-node reduce
mpir - Fallback to MPIR collectives
release_gather - Force shm optimized algo using release, gather
primitives
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_CH4_POSIX_COLL_SELECTION_TUNING_JSON_FILE)
Default: MPIR_CVAR_REDUCE_POSIX_INTRA_ALGORITHM_auto
MPIR_CVAR_IREDUCE_POSIX_INTRA_ALGORITHM
Aliases: MPIR_PARAM_IREDUCE_POSIX_INTRA_ALGORITHM
MPICH_IREDUCE_POSIX_INTRA_ALGORITHM
Description: Variable to select algorithm for intra-node reduce
mpir - Fallback to MPIR collectives
release_gather - Force shm optimized algo using release, gather
primitives
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_CH4_POSIX_COLL_SELECTION_TUNING_JSON_FILE)
Default: MPIR_CVAR_IREDUCE_POSIX_INTRA_ALGORITHM_auto
MPIR_CVAR_ALLREDUCE_POSIX_INTRA_ALGORITHM
Aliases: MPIR_PARAM_ALLREDUCE_POSIX_INTRA_ALGORITHM
MPICH_ALLREDUCE_POSIX_INTRA_ALGORITHM
Description: Variable to select algorithm for intra-node allreduce
mpir - Fallback to MPIR collectives
release_gather - Force shm optimized algo using release, gather
primitives
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_CH4_POSIX_COLL_SELECTION_TUNING_JSON_FILE)
Default: MPIR_CVAR_ALLREDUCE_POSIX_INTRA_ALGORITHM_auto
MPIR_CVAR_BARRIER_POSIX_INTRA_ALGORITHM
Aliases: MPIR_PARAM_BARRIER_POSIX_INTRA_ALGORITHM
MPICH_BARRIER_POSIX_INTRA_ALGORITHM
Description: Variable to select algorithm for intra-node barrier
mpir - Fallback to MPIR collectives
release_gather - Force shm optimized algo using release, gather
primitives
auto - Internal algorithm selection (can be overridden with
MPIR_CVAR_CH4_POSIX_COLL_SELECTION_TUNING_JSON_FILE)
Default: MPIR_CVAR_BARRIER_POSIX_INTRA_ALGORITHM_auto
MPIR_CVAR_ALLTOALL_POSIX_INTRA_ALGORITHM
Aliases: MPIR_PARAM_ALLTOALL_POSIX_INTRA_ALGORITHM
MPICH_ALLTOALL_POSIX_INTRA_ALGORITHM
Description: Variable to select algorithm for intra-node alltoall
mpir - Fallback to MPIR collectives (default)
ipc_read - Uses read-based collective with ipc
Default: MPIR_CVAR_ALLTOALL_POSIX_INTRA_ALGORITHM_mpir
MPIR_CVAR_ALLGATHER_POSIX_INTRA_ALGORITHM
Aliases: MPIR_PARAM_ALLGATHER_POSIX_INTRA_ALGORITHM
MPICH_ALLGATHER_POSIX_INTRA_ALGORITHM
Description: Variable to select algorithm for intra-node allgather
mpir - Fallback to MPIR collectives (default)
ipc_read - Uses read-based collective with ipc
Default: MPIR_CVAR_ALLGATHER_POSIX_INTRA_ALGORITHM_mpir
MPIR_CVAR_ALLGATHERV_POSIX_INTRA_ALGORITHM
Aliases: MPIR_PARAM_ALLGATHERV_POSIX_INTRA_ALGORITHM
MPICH_ALLGATHERV_POSIX_INTRA_ALGORITHM
Description: Variable to select algorithm for intra-node allgatherv
mpir - Fallback to MPIR collectives (default)
ipc_read - Uses read-based collective with ipc
Default: MPIR_CVAR_ALLGATHERV_POSIX_INTRA_ALGORITHM_mpir
MPIR_CVAR_POSIX_POLL_FREQUENCY
Aliases: MPIR_PARAM_POSIX_POLL_FREQUENCY
MPICH_POSIX_POLL_FREQUENCY
Description: This cvar sets the number of loops before the yield
function is called. A value of 0 disables yielding.
Default: 1000
MPIR_CVAR_BCAST_IPC_READ_MSG_SIZE_THRESHOLD
Aliases: MPIR_PARAM_BCAST_IPC_READ_MSG_SIZE_THRESHOLD
MPICH_BCAST_IPC_READ_MSG_SIZE_THRESHOLD
Description: Use gpu ipc read bcast only when the message size is
larger than this threshold.
Default: 256
MPIR_CVAR_ALLTOALL_IPC_READ_MSG_SIZE_THRESHOLD
Aliases: MPIR_PARAM_ALLTOALL_IPC_READ_MSG_SIZE_THRESHOLD
MPICH_ALLTOALL_IPC_READ_MSG_SIZE_THRESHOLD
Description: Use gpu ipc read alltoall only when the message size is
larger than this threshold.
Default: 256
MPIR_CVAR_ALLGATHER_IPC_READ_MSG_SIZE_THRESHOLD
Aliases: MPIR_PARAM_ALLGATHER_IPC_READ_MSG_SIZE_THRESHOLD
MPICH_ALLGATHER_IPC_READ_MSG_SIZE_THRESHOLD
Description: Use gpu ipc read allgather only when the message size is
larger than this threshold.
Default: 256
MPIR_CVAR_ALLGATHERV_IPC_READ_MSG_SIZE_THRESHOLD
Aliases: MPIR_PARAM_ALLGATHERV_IPC_READ_MSG_SIZE_THRESHOLD
MPICH_ALLGATHERV_IPC_READ_MSG_SIZE_THRESHOLD
Description: Use gpu ipc read allgatherv only when the message size is
larger than this threshold.
Default: 256
MPIR_CVAR_POSIX_NUM_COLLS_THRESHOLD
Aliases: MPIR_PARAM_POSIX_NUM_COLLS_THRESHOLD
MPICH_POSIX_NUM_COLLS_THRESHOLD
Description: Use posix optimized collectives (release_gather) only when
the total number of Bcast, Reduce, Barrier, and Allreduce calls on
the node level communicator is more than this threshold.
Default: 5
MPIR_CVAR_CH4_SHM_POSIX_EAGER
Aliases: MPIR_PARAM_CH4_SHM_POSIX_EAGER
MPICH_CH4_SHM_POSIX_EAGER
Description: If non-empty, this cvar specifies which shm posix eager
module to use
Default: ""
MPIR_CVAR_CH4_POSIX_COLL_SELECTION_TUNING_JSON_FILE
Aliases: MPIR_PARAM_CH4_POSIX_COLL_SELECTION_TUNING_JSON_FILE
MPICH_CH4_POSIX_COLL_SELECTION_TUNING_JSON_FILE
Description: Defines the location of tuning file.
Default: ""
MPIR_CVAR_CH4_POSIX_COLL_SELECTION_TUNING_JSON_FILE_GPU
Aliases: MPIR_PARAM_CH4_POSIX_COLL_SELECTION_TUNING_JSON_FILE_GPU
MPICH_CH4_POSIX_COLL_SELECTION_TUNING_JSON_FILE_GPU
Description: Defines the location of tuning file for GPU.
Default: ""
MPIR_CVAR_CH4_SHM_POSIX_TOPO_ENABLE
Aliases: MPIR_PARAM_CH4_SHM_POSIX_TOPO_ENABLE
MPICH_CH4_SHM_POSIX_TOPO_ENABLE
Description: Controls topology-aware communication in POSIX.
Default: 0
MPIR_CVAR_CH4_SHM_POSIX_IQUEUE_NUM_CELLS
Aliases: MPIR_PARAM_CH4_SHM_POSIX_IQUEUE_NUM_CELLS
MPICH_CH4_SHM_POSIX_IQUEUE_NUM_CELLS
Description: The number of cells used for the depth of the iqueue.
Default: 64
MPIR_CVAR_CH4_SHM_POSIX_IQUEUE_CELL_SIZE
Aliases: MPIR_PARAM_CH4_SHM_POSIX_IQUEUE_CELL_SIZE
MPICH_CH4_SHM_POSIX_IQUEUE_CELL_SIZE
Description: Size of each cell.
Default: 16384
MPIR_CVAR_COLL_SHM_LIMIT_PER_NODE
Aliases: MPIR_PARAM_COLL_SHM_LIMIT_PER_NODE
MPICH_COLL_SHM_LIMIT_PER_NODE
Description: Maximum shared memory created per node for optimized
intra-node collectives (in KB)
Default: 65536
MPIR_CVAR_BCAST_INTRANODE_BUFFER_TOTAL_SIZE
Aliases: MPIR_PARAM_BCAST_INTRANODE_BUFFER_TOTAL_SIZE
MPICH_BCAST_INTRANODE_BUFFER_TOTAL_SIZE
Description: Total size of the bcast buffer (in bytes)
Default: 32768
MPIR_CVAR_BCAST_INTRANODE_NUM_CELLS
Aliases: MPIR_PARAM_BCAST_INTRANODE_NUM_CELLS
MPICH_BCAST_INTRANODE_NUM_CELLS
Description: Number of cells the bcast buffer is divided into
Default: 4
MPIR_CVAR_REDUCE_INTRANODE_BUFFER_TOTAL_SIZE
Aliases: MPIR_PARAM_REDUCE_INTRANODE_BUFFER_TOTAL_SIZE
MPICH_REDUCE_INTRANODE_BUFFER_TOTAL_SIZE
Description: Total size of the reduce buffer per rank (in bytes)
Default: 32768
MPIR_CVAR_REDUCE_INTRANODE_NUM_CELLS
Aliases: MPIR_PARAM_REDUCE_INTRANODE_NUM_CELLS
MPICH_REDUCE_INTRANODE_NUM_CELLS
Description: Number of cells the reduce buffer is divided into, for
each rank
Default: 4
MPIR_CVAR_BCAST_INTRANODE_TREE_KVAL
Aliases: MPIR_PARAM_BCAST_INTRANODE_TREE_KVAL
MPICH_BCAST_INTRANODE_TREE_KVAL
Description: K value for the kary/knomial tree for intra-node bcast
Default: 64
MPIR_CVAR_BCAST_INTRANODE_TREE_TYPE
Aliases: MPIR_PARAM_BCAST_INTRANODE_TREE_TYPE
MPICH_BCAST_INTRANODE_TREE_TYPE
Description: Tree type for intra-node bcast tree kary - kary tree
type knomial_1 - knomial_1 tree type (ranks are added in order from
the left side) knomial_2 - knomial_2 tree type (ranks are added in
order from the right side) knomial_2 is only supported with non
topology aware trees.
Default: "kary"
MPIR_CVAR_REDUCE_INTRANODE_MSG_SIZE_THRESHOLD
Aliases: MPIR_PARAM_REDUCE_INTRANODE_MSG_SIZE_THRESHOLD
MPICH_REDUCE_INTRANODE_MSG_SIZE_THRESHOLD
Description: MPIR_CVAR_REDUCE_INTRANODE_TREE_KVAL and
MPIR_CVAR_REDUCE_INTRANODE_TREE_TYPE are used when the message size
is smaller than or equal to this threshold;
MPIR_CVAR_REDUCE_INTRANODE_TREE_KVAL_LARGE and
MPIR_CVAR_REDUCE_INTRANODE_TREE_TYPE_LARGE are used when the
message size is larger than this threshold.
Default: 2048
MPIR_CVAR_REDUCE_INTRANODE_TREE_KVAL
Aliases: MPIR_PARAM_REDUCE_INTRANODE_TREE_KVAL
MPICH_REDUCE_INTRANODE_TREE_KVAL
Description: K value for the kary/knomial tree for intra-node reduce
Default: 4
MPIR_CVAR_REDUCE_INTRANODE_TREE_KVAL_LARGE
Aliases: MPIR_PARAM_REDUCE_INTRANODE_TREE_KVAL_LARGE
MPICH_REDUCE_INTRANODE_TREE_KVAL_LARGE
Description: K value for the kary/knomial tree for intra-node reduce.
Used for large messages.
Default: 2
MPIR_CVAR_REDUCE_INTRANODE_TREE_TYPE
Aliases: MPIR_PARAM_REDUCE_INTRANODE_TREE_TYPE
MPICH_REDUCE_INTRANODE_TREE_TYPE
Description: Tree type for intra-node reduce tree kary - kary tree
type knomial_1 - knomial_1 tree type (ranks are added in order from
the left side) knomial_2 - knomial_2 tree type (ranks are added in
order from the right side) knomial_2 is only supported with non
topology aware trees.
Default: "kary"
MPIR_CVAR_REDUCE_INTRANODE_TREE_TYPE_LARGE
Aliases: MPIR_PARAM_REDUCE_INTRANODE_TREE_TYPE_LARGE
MPICH_REDUCE_INTRANODE_TREE_TYPE_LARGE
Description: Tree type for intra-node reduce tree. Used for large
messages. kary - kary tree type knomial_1 - knomial_1 tree
type (ranks are added in order from the left side) knomial_2 -
knomial_2 tree type (ranks are added in order from the right side)
knomial_2 is only supported with non topology aware trees.
Default: "kary"
MPIR_CVAR_ENABLE_INTRANODE_TOPOLOGY_AWARE_TREES
Aliases: MPIR_PARAM_ENABLE_INTRANODE_TOPOLOGY_AWARE_TREES
MPICH_ENABLE_INTRANODE_TOPOLOGY_AWARE_TREES
Description: Enable collective specific intra-node trees which leverage
the memory hierarchy of a machine. Depends on hwloc to extract the
binding information of each rank. Pick a leader rank per package
(socket), then create a per_package tree for ranks on a same
package, package leaders tree for package leaders. For Bcast -
Assemble the per_package and package_leaders tree in such a way
that leaders interact among themselves first before interacting
with package local ranks. Both the package_leaders and per_package
trees are left skewed (children are added from left to right, first
child to be added is the first one to be processed in traversal)
For Reduce - Assemble the per_package and package_leaders tree in
such a way that a leader rank interacts with its package local
ranks first, then with the other package leaders. Both the
per_package and package_leaders tree is right skewed (children are
added in reverse order, first child to be added is the last one to
be processed in traversal) The tree radix and tree type of
package_leaders and per_package tree is
MPIR_CVAR_BCAST{REDUCE}_INTRANODE_TREE_KVAL and
MPIR_CVAR_BCAST{REDUCE}_INTRANODE_TREE_TYPE respectively for bast
and reduce. But of as now topology aware trees are only kary and
knomial_1. knomial_2 is not implemented.
Default: 1
MPIR_CVAR_BARRIER_COMPOSITION
Aliases: MPIR_PARAM_BARRIER_COMPOSITION
MPICH_BARRIER_COMPOSITION
Description: Select composition (inter_node + intra_node) for Barrier 0
Auto selection 1 NM + SHM 2 NM only
Default: 0
MPIR_CVAR_BCAST_COMPOSITION
Aliases: MPIR_PARAM_BCAST_COMPOSITION
MPICH_BCAST_COMPOSITION
Description: Select composition (inter_node + intra_node) for Bcast 0
Auto selection 1 NM + SHM with explicit send-recv between rank 0
and root 2 NM + SHM without the explicit send-recv 3 NM only
Default: 0
MPIR_CVAR_ALLREDUCE_COMPOSITION
Aliases: MPIR_PARAM_ALLREDUCE_COMPOSITION
MPICH_ALLREDUCE_COMPOSITION
Description: Select composition (inter_node + intra_node) for Allreduce
0 Auto selection 1 NM + SHM with reduce + bcast 2 NM only
composition 3 SHM only composition 4 Multi leaders based inter node
+ intra node composition
Default: 0
MPIR_CVAR_ALLGATHER_COMPOSITION
Aliases: MPIR_PARAM_ALLGATHER_COMPOSITION
MPICH_ALLGATHER_COMPOSITION
Description: Select composition (inter_node + intra_node) for Allgather
0 Auto selection 1 Multi leaders based inter node + intra node
composition 2 NM only composition
Default: 0
MPIR_CVAR_ALLTOALL_COMPOSITION
Aliases: MPIR_PARAM_ALLTOALL_COMPOSITION
MPICH_ALLTOALL_COMPOSITION
Description: Select composition (inter_node + intra_node) for Alltoall
0 Auto selection 1 Multi leaders based inter node + intra node
composition 2 NM only composition
Default: 0
MPIR_CVAR_REDUCE_COMPOSITION
Aliases: MPIR_PARAM_REDUCE_COMPOSITION
MPICH_REDUCE_COMPOSITION
Description: Select composition (inter_node + intra_node) for Reduce 0
Auto selection 1 NM + SHM with explicit send-recv between rank 0
and root 2 NM + SHM without the explicit send-recv 3 NM only
Default: 0
MPIR_CVAR_ALLTOALL_SHM_PER_RANK
Aliases: MPIR_PARAM_ALLTOALL_SHM_PER_RANK
MPICH_ALLTOALL_SHM_PER_RANK
Description: Shared memory region per rank for multi-leaders based
composition for MPI_Alltoall (in bytes)
Default: 4096
MPIR_CVAR_ALLGATHER_SHM_PER_RANK
Aliases: MPIR_PARAM_ALLGATHER_SHM_PER_RANK
MPICH_ALLGATHER_SHM_PER_RANK
Description: Shared memory region per rank for multi-leaders based
composition for MPI_Allgather (in bytes)
Default: 4096
MPIR_CVAR_NUM_MULTI_LEADS
Aliases: MPIR_PARAM_NUM_MULTI_LEADS
MPICH_NUM_MULTI_LEADS
Description: Number of leader ranks per node to be used for
multi-leaders based collective algorithms
Default: 4
MPIR_CVAR_ALLREDUCE_SHM_PER_LEADER
Aliases: MPIR_PARAM_ALLREDUCE_SHM_PER_LEADER
MPICH_ALLREDUCE_SHM_PER_LEADER
Description: Shared memory region per node-leader for multi-leaders
based composition for MPI_Allreduce (in bytes) If it is undefined
by the user, it is set to the message size of the first call to the
algorithm. Max shared memory size is limited to 4MB.
Default: -1
MPIR_CVAR_ALLREDUCE_CACHE_PER_LEADER
Aliases: MPIR_PARAM_ALLREDUCE_CACHE_PER_LEADER
MPICH_ALLREDUCE_CACHE_PER_LEADER
Description: Amount of data reduced in allreduce delta composition's
reduce local step (in bytes). Smaller msg size per leader avoids
cache misses and improves performance. Experiments indicate 512 to
be the best value.
Default: 512
MPIR_CVAR_ALLREDUCE_LOCAL_COPY_OFFSETS
Aliases: MPIR_PARAM_ALLREDUCE_LOCAL_COPY_OFFSETS
MPICH_ALLREDUCE_LOCAL_COPY_OFFSETS
Description: number of offsets in the allreduce delta composition's
local copy The value of 2 performed the best in our 2 NIC test
cases.
Default: 2
MPIR_CVAR_CH4_NETMOD
Aliases: MPIR_PARAM_CH4_NETMOD
MPICH_CH4_NETMOD
Description: If non-empty, this cvar specifies which network module to
use
Default: ""
MPIR_CVAR_CH4_SHM
Aliases: MPIR_PARAM_CH4_SHM
MPICH_CH4_SHM
Description: If non-empty, this cvar specifies which shm module to use
Default: ""
MPIR_CVAR_CH4_ROOTS_ONLY_PMI
Aliases: MPIR_PARAM_CH4_ROOTS_ONLY_PMI
MPICH_CH4_ROOTS_ONLY_PMI
Description: Enables an optimized business card exchange over PMI for
node root processes only.
Default: 1
MPIR_CVAR_CH4_RUNTIME_CONF_DEBUG
Aliases: MPIR_PARAM_CH4_RUNTIME_CONF_DEBUG
MPICH_CH4_RUNTIME_CONF_DEBUG
Description: If enabled, CH4-level runtime configurations are printed
out
Default: 0
MPIR_CVAR_CH4_MT_MODEL
Aliases: MPIR_PARAM_CH4_MT_MODEL
MPICH_CH4_MT_MODEL
Description: Specifies the CH4 multi-threading model. Possible values
are: direct (default) lockless
Default: ""
MPIR_CVAR_CH4_NUM_VCIS
Aliases: MPIR_PARAM_CH4_NUM_VCIS
MPICH_CH4_NUM_VCIS
Description: Sets the number of VCIs to be implicitly used (should be a
subset of MPIDI_CH4_MAX_VCIS).
Default: 1
MPIR_CVAR_CH4_RESERVE_VCIS
Aliases: MPIR_PARAM_CH4_RESERVE_VCIS
MPICH_CH4_RESERVE_VCIS
Description: Sets the number of VCIs that user can explicitly allocate
(should be a subset of MPIDI_CH4_MAX_VCIS).
Default: 0
MPIR_CVAR_CH4_COLL_SELECTION_TUNING_JSON_FILE
Aliases: MPIR_PARAM_CH4_COLL_SELECTION_TUNING_JSON_FILE
MPICH_CH4_COLL_SELECTION_TUNING_JSON_FILE
Description: Defines the location of tuning file.
Default: ""
MPIR_CVAR_CH4_COLL_SELECTION_TUNING_JSON_FILE_GPU
Aliases: MPIR_PARAM_CH4_COLL_SELECTION_TUNING_JSON_FILE_GPU
MPICH_CH4_COLL_SELECTION_TUNING_JSON_FILE_GPU
Description: Defines the location of tuning file for GPU.
Default: ""
MPIR_CVAR_CH4_IOV_DENSITY_MIN
Aliases: MPIR_PARAM_CH4_IOV_DENSITY_MIN
MPICH_CH4_IOV_DENSITY_MIN
Description: Defines the threshold of high-density datatype. The
density is calculated by (datatype_size /
datatype_num_contig_blocks).
Default: 16384
MPIR_CVAR_CH4_PACK_BUFFER_SIZE
Aliases: MPIR_PARAM_CH4_PACK_BUFFER_SIZE
MPICH_CH4_PACK_BUFFER_SIZE
Description: Specifies the number of buffers for packing/unpacking
active messages in each block of the pool. The size here should be
greater or equal to the max of the eager buffer limit of SHM and
NETMOD.
Default: 16384
MPIR_CVAR_CH4_NUM_PACK_BUFFERS_PER_CHUNK
Aliases: MPIR_PARAM_CH4_NUM_PACK_BUFFERS_PER_CHUNK
MPICH_CH4_NUM_PACK_BUFFERS_PER_CHUNK
Description: Specifies the number of buffers for packing/unpacking
active messages in each block of the pool.
Default: 64
MPIR_CVAR_CH4_MAX_NUM_PACK_BUFFERS
Aliases: MPIR_PARAM_CH4_MAX_NUM_PACK_BUFFERS
MPICH_CH4_MAX_NUM_PACK_BUFFERS
Description: Specifies the max number of buffers for packing/unpacking
buffers in the pool. Use 0 for unlimited.
Default: 0
MPIR_CVAR_CH4_GPU_COLL_SWAP_BUFFER_SZ
Aliases: MPIR_PARAM_CH4_GPU_COLL_SWAP_BUFFER_SZ
MPICH_CH4_GPU_COLL_SWAP_BUFFER_SZ
Description: Specifies the buffer size (in bytes) for GPU collectives
data transfer.
Default: 1048576
MPIR_CVAR_CH4_GPU_COLL_NUM_BUFFERS_PER_CHUNK
Aliases: MPIR_PARAM_CH4_GPU_COLL_NUM_BUFFERS_PER_CHUNK
MPICH_CH4_GPU_COLL_NUM_BUFFERS_PER_CHUNK
Description: Specifies the number of buffers for GPU collectives data
transfer in each block/chunk of the pool.
Default: 1
MPIR_CVAR_CH4_GPU_COLL_MAX_NUM_BUFFERS
Aliases: MPIR_PARAM_CH4_GPU_COLL_MAX_NUM_BUFFERS
MPICH_CH4_GPU_COLL_MAX_NUM_BUFFERS
Description: Specifies the total number of buffers for GPU collectives
data transfer.
Default: 256
MPIR_CVAR_CH4_GLOBAL_PROGRESS
Aliases: MPIR_PARAM_CH4_GLOBAL_PROGRESS
MPICH_CH4_GLOBAL_PROGRESS
Description: If on, poll global progress every once a while. With
per-vci configuration, turning global progress off may improve the
threading performance.
Default: 1
MPIR_CVAR_CH4_COMM_CONNECT_TIMEOUT
Aliases: MPIR_PARAM_CH4_COMM_CONNECT_TIMEOUT
MPICH_CH4_COMM_CONNECT_TIMEOUT
Description: The default time out period in seconds for a connection
attempt to the server communicator where the named port exists but
no pending accept. User can change the value for a specified
connection through its info argument.
Default: 180
MPIR_CVAR_CH4_ENABLE_STREAM_WORKQ
Aliases: MPIR_PARAM_CH4_ENABLE_STREAM_WORKQ
MPICH_CH4_ENABLE_STREAM_WORKQ
Description: Enable stream enqueue operations via stream work queue.
Requires progress thread on the corresponding MPIX stream.
Reference: MPIX_Stream_progress and MPIX_Start_progress_thread.
Default: 0
MPIR_CVAR_CH4_RMA_MEM_EFFICIENT
Aliases: MPIR_PARAM_CH4_RMA_MEM_EFFICIENT
MPICH_CH4_RMA_MEM_EFFICIENT
Description: If true, memory-saving mode is on, per-target object is
released at the epoch end call. If false, performance-efficient
mode is on, all allocated target objects are cached and freed at
win_finalize.
Default: 0
MPIR_CVAR_CH4_RMA_ENABLE_DYNAMIC_AM_PROGRESS
Aliases: MPIR_PARAM_CH4_RMA_ENABLE_DYNAMIC_AM_PROGRESS
MPICH_CH4_RMA_ENABLE_DYNAMIC_AM_PROGRESS
Description: If true, allows RMA synchronization calls to dynamically
reduce the frequency of internal progress polling for incoming RMA
active messages received on the target process. The RMA
synchronization call initially polls progress with a low frequency
(defined by MPIR_CVAR_CH4_RMA_AM_PROGRESS_LOW_FREQ_INTERVAL) to
reduce synchronization overhead. Once any RMA active message has
been received, it will always poll progress once at every
synchronization call to ensure prompt target-side progress.
Effective only for passive target synchronization
MPI_Win_flush{_all} and MPI_Win_flush_local{_all}.
Default: 0
MPIR_CVAR_CH4_RMA_AM_PROGRESS_INTERVAL
Aliases: MPIR_PARAM_CH4_RMA_AM_PROGRESS_INTERVAL
MPICH_CH4_RMA_AM_PROGRESS_INTERVAL
Description: Specifies a static interval of progress polling for
incoming RMA active messages received on the target process.
Effective only for passive-target synchronization
MPI_Win_flush{_all} and MPI_Win_flush_local{_all}. Interval
indicates the number of performed flush calls before polling. It is
counted globally across all windows. Invalid when
MPIR_CVAR_CH4_RMA_ENABLE_DYNAMIC_AM_PROGRESS is true.
Default: 1
MPIR_CVAR_CH4_RMA_AM_PROGRESS_LOW_FREQ_INTERVAL
Aliases: MPIR_PARAM_CH4_RMA_AM_PROGRESS_LOW_FREQ_INTERVAL
MPICH_CH4_RMA_AM_PROGRESS_LOW_FREQ_INTERVAL
Description: Specifies the interval of progress polling with low
frequency for incoming RMA active message received on the target
process. Effective only for passive-target synchronization
MPI_Win_flush{_all} and MPI_Win_flush_local{_all}. Interval
indicates the number of performed flush calls before polling. It is
counted globally across all windows. Used when
MPIR_CVAR_CH4_RMA_ENABLE_DYNAMIC_AM_PROGRESS is true.
Default: 100
MPIR_CVAR_GENQ_SHMEM_POOL_FREE_QUEUE_SENDER_SIDE
Aliases: MPIR_PARAM_GENQ_SHMEM_POOL_FREE_QUEUE_SENDER_SIDE
MPICH_GENQ_SHMEM_POOL_FREE_QUEUE_SENDER_SIDE
Description: The genq shmem code allocates pools of cells on each
process and, when needed, a cell is removed from the pool and
passed to another process. This can happen by either removing a
cell from the pool of the sending process or from the pool of the
receiving process. This CVAR determines which pool to use. If true,
the cell will come from the sender-side. If false, the cell will
com from the receiver-side. There are specific advantages of using
receiver-side cells when combined with the "avx" fast configure
option, which allows MPICH to use AVX streaming copy
intrintrinsics, when available, to avoid polluting the cache of the
sender with the data being copied to the receiver. Using
receiver-side cells does have the trade-off of requiring an MPMC
lock for the free queue rather than an MPSC lock, which is used for
sender-side cells. Initial performance analysis shows that using
the MPMC lock in this case had no significant performance loss. By
default, the queue will continue to use sender-side queues until
the performance impact is verified.
Default: 1
MPIR_CVAR_ENABLE_HCOLL
Aliases: MPIR_PARAM_ENABLE_HCOLL
MPICH_ENABLE_HCOLL
Description: Enable hcoll collective support.
Default: 0
MPIR_CVAR_COLL_SCHED_DUMP
Aliases: MPIR_PARAM_COLL_SCHED_DUMP
MPICH_COLL_SCHED_DUMP
Description: Print schedule data for nonblocking collective operations.
Default: 0
MPIR_CVAR_SHM_RANDOM_ADDR_RETRY
Aliases: MPIR_PARAM_SHM_RANDOM_ADDR_RETRY
MPICH_SHM_RANDOM_ADDR_RETRY
Description: The default number of retries for generating a random
address. A retrying involves only local operations.
Default: 100
MPIR_CVAR_SHM_SYMHEAP_RETRY
Aliases: MPIR_PARAM_SHM_SYMHEAP_RETRY
MPICH_SHM_SYMHEAP_RETRY
Description: The default number of retries for allocating a symmetric
heap in shared memory. A retrying involves collective communication
over the group in the shared memory.
Default: 100
MPIR_CVAR_ENABLE_HEAVY_YIELD
Aliases: MPIR_PARAM_ENABLE_HEAVY_YIELD
MPICH_ENABLE_HEAVY_YIELD
Description: If enabled, use nanosleep to ensure other threads have a
chance to grab the lock. Note: this may not work with some thread
runtimes, e.g. non-preemptive user-level threads.
Default: 0
