README.envvar
(C) 2010 by Argonne National Laboratory. See COPYRIGHT in top-level directory. Automatically generated by: ./maint/extractcvars at: Fri Nov 10 20:21:16 2017 DO NOT EDIT!!! This file lists the various environment variables available to change the behavior of the MPICH library. These are intended to be used by advanced users. --------------------------------------------------------------------------- MPIR_CVAR_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_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_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_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_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_SUPPRESS_ABORT_MESSAGE Aliases: MPIR_PARAM_SUPPRESS_ABORT_MESSAGE MPICH_SUPPRESS_ABORT_MESSAGE Description: Disable printing of abort error message. Default: 0 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_ENABLE_SMP_REDUCE Aliases: MPIR_PARAM_ENABLE_SMP_REDUCE MPICH_ENABLE_SMP_REDUCE Description: Enable SMP aware reduce. Default: 1 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_REDSCAT_COMMUTATIVE_LONG_MSG_SIZE Aliases: MPIR_PARAM_REDSCAT_COMMUTATIVE_LONG_MSG_SIZE MPICH_REDSCAT_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_BCAST_MIN_PROCS Aliases: MPIR_PARAM_BCAST_MIN_PROCS MPICH_BCAST_MIN_PROCS Description: Let's define short messages as messages with size < MPIR_CVAR_BCAST_SHORT_MSG_SIZE, and medium messages as messages with size >= MPIR_CVAR_BCAST_SHORT_MSG_SIZE but < MPIR_CVAR_BCAST_LONG_MSG_SIZE, and long messages as messages with size >= MPIR_CVAR_BCAST_LONG_MSG_SIZE. The broadcast algorithms selection procedure is as follows. For short messages or when the number of processes is < MPIR_CVAR_BCAST_MIN_PROCS, we do broadcast using the binomial tree algorithm. Otherwise, for medium messages and with a power-of-two number of processes, we do broadcast based on a scatter followed by a recursive doubling allgather algorithm. Otherwise, for long messages or with non power-of-two number of processes, we do broadcast based on a scatter followed by a ring allgather algorithm. (See also: MPIR_CVAR_BCAST_SHORT_MSG_SIZE, MPIR_CVAR_BCAST_LONG_MSG_SIZE) Default: 8 MPIR_CVAR_BCAST_SHORT_MSG_SIZE Aliases: MPIR_PARAM_BCAST_SHORT_MSG_SIZE MPICH_BCAST_SHORT_MSG_SIZE Description: Let's define short messages as messages with size < MPIR_CVAR_BCAST_SHORT_MSG_SIZE, and medium messages as messages with size >= MPIR_CVAR_BCAST_SHORT_MSG_SIZE but < MPIR_CVAR_BCAST_LONG_MSG_SIZE, and long messages as messages with size >= MPIR_CVAR_BCAST_LONG_MSG_SIZE. The broadcast algorithms selection procedure is as follows. For short messages or when the number of processes is < MPIR_CVAR_BCAST_MIN_PROCS, we do broadcast using the binomial tree algorithm. Otherwise, for medium messages and with a power-of-two number of processes, we do broadcast based on a scatter followed by a recursive doubling allgather algorithm. Otherwise, for long messages or with non power-of-two number of processes, we do broadcast based on a scatter followed by a ring allgather algorithm. (See also: MPIR_CVAR_BCAST_MIN_PROCS, MPIR_CVAR_BCAST_LONG_MSG_SIZE) Default: 12288 MPIR_CVAR_BCAST_LONG_MSG_SIZE Aliases: MPIR_PARAM_BCAST_LONG_MSG_SIZE MPICH_BCAST_LONG_MSG_SIZE Description: Let's define short messages as messages with size < MPIR_CVAR_BCAST_SHORT_MSG_SIZE, and medium messages as messages with size >= MPIR_CVAR_BCAST_SHORT_MSG_SIZE but < MPIR_CVAR_BCAST_LONG_MSG_SIZE, and long messages as messages with size >= MPIR_CVAR_BCAST_LONG_MSG_SIZE. The broadcast algorithms selection procedure is as follows. For short messages or when the number of processes is < MPIR_CVAR_BCAST_MIN_PROCS, we do broadcast using the binomial tree algorithm. Otherwise, for medium messages and with a power-of-two number of processes, we do broadcast based on a scatter followed by a recursive doubling allgather algorithm. Otherwise, for long messages or with non power-of-two number of processes, we do broadcast based on a scatter followed by a ring allgather algorithm. (See also: MPIR_CVAR_BCAST_MIN_PROCS, MPIR_CVAR_BCAST_SHORT_MSG_SIZE) Default: 524288 MPIR_CVAR_ENABLE_SMP_BCAST Aliases: MPIR_PARAM_ENABLE_SMP_BCAST MPICH_ENABLE_SMP_BCAST Description: Enable SMP aware broadcast (See also: MPIR_CVAR_MAX_SMP_BCAST_MSG_SIZE) Default: 1 MPIR_CVAR_MAX_SMP_BCAST_MSG_SIZE Aliases: MPIR_PARAM_MAX_SMP_BCAST_MSG_SIZE MPICH_MAX_SMP_BCAST_MSG_SIZE Description: Maximum message size for which SMP-aware broadcast is used. A value of '0' uses SMP-aware broadcast for all message sizes. (See also: MPIR_CVAR_ENABLE_SMP_BCAST) Default: 0 MPIR_CVAR_GATHERV_INTER_SSEND_MIN_PROCS Aliases: MPIR_PARAM_GATHERV_INTER_SSEND_MIN_PROCS MPICH_GATHERV_INTER_SSEND_MIN_PROCS Description: Use Ssend (synchronous send) for intercommunicator MPI_Gatherv if the "group B" size is >= this value. Specifying "-1" always avoids using Ssend. For backwards compatibility, specifying "0" uses the default value. Default: 32 MPIR_CVAR_ALLREDUCE_SHORT_MSG_SIZE Aliases: MPIR_PARAM_ALLREDUCE_SHORT_MSG_SIZE MPICH_ALLREDUCE_SHORT_MSG_SIZE Description: the short message algorithm will be used if the send buffer size is <= this value (in bytes) Default: 2048 MPIR_CVAR_ENABLE_SMP_COLLECTIVES Aliases: MPIR_PARAM_ENABLE_SMP_COLLECTIVES MPICH_ENABLE_SMP_COLLECTIVES Description: Enable SMP aware collective communication. Default: 1 MPIR_CVAR_ENABLE_SMP_ALLREDUCE Aliases: MPIR_PARAM_ENABLE_SMP_ALLREDUCE MPICH_ENABLE_SMP_ALLREDUCE Description: Enable SMP aware allreduce. Default: 1 MPIR_CVAR_MAX_SMP_ALLREDUCE_MSG_SIZE Aliases: MPIR_PARAM_MAX_SMP_ALLREDUCE_MSG_SIZE MPICH_MAX_SMP_ALLREDUCE_MSG_SIZE Description: Maximum message size for which SMP-aware allreduce is used. A value of '0' uses SMP-aware allreduce for all message sizes. Default: 0 MPIR_CVAR_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_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_ENABLE_SMP_BARRIER Aliases: MPIR_PARAM_ENABLE_SMP_BARRIER MPICH_ENABLE_SMP_BARRIER Description: Enable SMP aware barrier. Default: 1 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_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_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_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_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_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_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 MPIR_WaitForDebugger-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_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_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_CH3_ENABLE_HCOLL Aliases: MPIR_PARAM_CH3_ENABLE_HCOLL MPICH_CH3_ENABLE_HCOLL Description: If true, enable HCOLL collectives. Default: 0 MPIR_CVAR_CH3_NOLOCAL Aliases: MPIR_PARAM_CH3_NOLOCAL MPICH_CH3_NOLOCAL MPIR_CVAR_CH3_NO_LOCAL MPIR_PARAM_CH3_NO_LOCAL MPICH_CH3_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_CH3_ODD_EVEN_CLIQUES Aliases: MPIR_PARAM_CH3_ODD_EVEN_CLIQUES MPICH_CH3_ODD_EVEN_CLIQUES MPIR_CVAR_CH3_EVEN_ODD_CLIQUES MPIR_PARAM_CH3_EVEN_ODD_CLIQUES MPICH_CH3_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. Default: 0 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_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 calue. Default: 655360 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_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 nagative, 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 avaliable in the ending synchronization call. Default: 0 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 synchonization approach. Change this value if programs fail because they run out of requests or other internal resources Default: 128 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 immediatly. 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 immediatly. 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 immediatly. Requires a positive value. Default: 256 MPIR_CVAR_ENABLE_FT Aliases: MPIR_PARAM_ENABLE_FT MPICH_ENABLE_FT Description: Enable fault tolerance functions 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_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_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_NEMESIS_LMT_DMA_THRESHOLD Aliases: MPIR_PARAM_NEMESIS_LMT_DMA_THRESHOLD MPICH_NEMESIS_LMT_DMA_THRESHOLD Description: Messages larger than this size will use the "dma" (knem) intranode LMT implementation, if it is enabled and available. Default: 2097152 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_OFI_USE_PROVIDER Aliases: MPIR_PARAM_OFI_USE_PROVIDER MPICH_OFI_USE_PROVIDER Description: If non-null, choose an OFI provider by name Default: NULL MPIR_CVAR_OFI_DUMP_PROVIDERS Aliases: MPIR_PARAM_OFI_DUMP_PROVIDERS MPICH_OFI_DUMP_PROVIDERS Description: If true, dump provider information at init Default: 0 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_MXM_BULK_CONNECT Aliases: MPIR_PARAM_NEMESIS_MXM_BULK_CONNECT MPICH_NEMESIS_MXM_BULK_CONNECT Description: If true, force mxm to connect all processes at initialization time. Default: 0 MPIR_CVAR_NEMESIS_MXM_BULK_DISCONNECT Aliases: MPIR_PARAM_NEMESIS_MXM_BULK_DISCONNECT MPICH_NEMESIS_MXM_BULK_DISCONNECT Description: If true, force mxm to disconnect all processes at finalization time. Default: 0 MPIR_CVAR_NEMESIS_MXM_HUGEPAGE Aliases: MPIR_PARAM_NEMESIS_MXM_HUGEPAGE MPICH_NEMESIS_MXM_HUGEPAGE Description: If true, mxm tries detecting hugepage support. On HPC-X 2.3 and earlier, this might cause problems on Ubuntu and other platforms even if the system provides hugepage support. Default: 0