poe
 
 
  NAME
 
  poe - Invokes the Parallel Operating Environment (POE) for loading and
  executing programs on remote processor nodes.
 
 
  SYNOPSIS
 
  poe [-h] [program] [program_options]...
  [-adapter_use adapter_specifier]
  [-cpu_use cpu_specifier]
  [-euidevice device_specifier]
  [-euilib {ip | us}]
  [-euilibpath path_specifier]
  [{-hostfile | -hfile} host_file_name]
  [-procs partition_size]
  [-pulse interval]
  [-resd {yes | no}]
  [-retry retry_interval]
  [-retrycount retry_count]
  [-rmpool pool_ID]
  [-savehostfile output_file_name]
  [-spname name]
  [-cmdfile commands_file]
  [-newjob {yes | no}]
  [-pgmmodel {spmd | mpmd}]
  [-labelio {yes | no}]
  [-stdinmode {all | none | task_ID}]
  [-stdoutmode {unordered | ordered | task_ID}]
  [{-samplefreq | -sfreq} samp_int]
  [{-tbuffsize | -tbsize} buffer_size]
  [{-tbuffwrap | -tbwrap} {yes | no}]
  [-tmpdir temp_trace_directory]
  [{-tracedir | -tdir} final_trace_directory]
  [{-tracefile | -tfile} trace_file_name]
  [{-tracelevel | -tlevel} level_int]
  [{-ttempsize | -ttsize} temp_file_size]
  [{-infolevel | -ilevel} message_level]
  [-pmdlog {yes | no}]
  [-buffer_mem] memory_size
  [-css_interrupt {yes | no}]
  [-eager_limit size_limit]
  [-intrdelay delay_parameter]
  [-max_typedepth maximum_depth]
  [-use_flow_control {yes | no}]
  [-thread_stacksize]
  [-single_thread {no | yes}]
  [-wait_mode {poll | yield | sleep}]
  [-polling_interval interval]
  [-euidevelop {yes | no | deb | min | nor}]
  [-pmlights number_of_lights]
  [-usrport port_ID] [fence_string additional_options]
  [-coredir]
 
  The poe command invokes the Parallel Operating Environment for loading
  and executing programs on remote processor nodes. The operation of POE
  is influenced by a number of POE environment variables. The flag
  options on this command are each used to temporarily override one of
  these environment variables. User program_options can be freely
  interspersed with the flag options. If no program is specified, POE
  will either prompt you for programs to load, or, if the MP_CMDFILE
  environment variable is set, will load the partition using the
  specified commands file.
 
 
  FLAGS
 
  The -h flag, when used, must appear immediately after poe, and causes
  the poe man page, if it exists, to be printed to the screen.
 
  The remaining flags you can specify on this command are used to
  temporarily override POE environment variables. For more information
  on valid values, and on what a particular flag sets, refer to the
  description of its associated environment variable in the ENVIRONMENT
  VARIABLES section. The following flags are grouped by function.
 
  The following Partition Manager control flags override the associated
  environment variables.
 
  -adapter_use        MP_ADAPTER_USE
  -cpu_use            MP_CPU_USE
  -euidevice          MP_EUIDEVICE
  -euilib             MP_EUILIB
  -euilibpath         MP_EUILIBPATH
  -hostfile or -hfile MP_HOSTFILE
  -procs              MP_PROCS
  -pulse              MP_PULSE
  -resd               MP_RESD
  -retry              MP_RETRY
  -retrycount         MP_RETRYCOUNT
  -msg_api            MP_MSG_API
  -rmpool             MP_RMPOOL
  -nodes              MP_NODES
  -tasks_per_node     MP_TASKS_PER_NODE
  -savehostfile       MP_SAVEHOSTFILE
  -spname             SP_NAME
 
  The following Job Specification flags override the associated
  environment variables.
 
  -cmdfile            MP_CMDFILE
  -newjob             MP_NEWJOB
  -pgmmodel           MP_PGMMODEL
 
  The following I/O Control flags override the associated environment
  variables.
 
  -labelio            MP_LABELIO
  -stdinmode          MP_STDINMODE
  -stdoutmode         MP_STDOUTMODE
 
  The following VT Trace Collection flags override the associated
  environment variables.
 
  -samplefreq or -sfreq
                      MP_SAMPLEFREQ
  -tbuffsize or -tbsize
                      MP_TBUFFSIZE
  -tbuffwrap or -tbwrap
                      MP_TBUFFWRAP
  -tmpdir             MP_TMPDIR
  -tracedir or -tdir  MP_TRACEDIR
  -tracefile or -tfile
                      MP_TRACEFILE
  -tracelevel or -tlevel
                      MP_TRACELEVEL
  -ttempsize or -ttsize
                      MP_TTEMPSIZE
 
  The following generation of diagnostic information flags override the
  associated environment variables.
 
  -infolevel or -ilevel
                      MP_INFOLEVEL
  -pmdlog             MP_PMDLOG
 
  The following Message Passing flags override the associated
  environment variables.
 
  -buffer_mem         MP_BUFFER_MEM
  -css_interrupt      MP_CSS_INTERRUPT
  -eager_limit        MP_EAGER_LIMIT
  -intrdelay          MP_INTRDELAY
  -max_typedepth      MP_MAX_TYPEDEPTH
  -use_flow_control   MP_USE_FLOW_CONTROL
  -thread_stacksize   MP_THREAD_STACKSIZE
  -single_thread      MP_SINGLE_THREAD
  -wait_mode          MP_WAIT_MODE
  -polling_interval   MP_POLLING_INTERVAL
 
  The following are miscellaneous flags:
 
  -euidevelop         Overrides the MP_EUIDEVELOP environment variable.
 
  -pmlights           Determines the number of lights displayed (per
                      row) on the Program Marker Array. This overrides
                      the MP_PMLIGHTS environment variable. For more
                      information on the Program Marker Array, refer to
                      the manual page for the pmarray command.
 
  -usrport            Overrides the MP_USRPORT environment variable.
 
  -coredir            Overrides the MP_COREDIR environment variable.
 
 
  DESCRIPTION
 
  The poe command invokes the Parallel Operating Environment for loading
  and executing programs on remote nodes. You can enter it at your home
  node to:
 
  o   load and execute an SPMD program on all nodes of your partition.
 
  o   individually load the nodes of your partition with an MPMD job.
 
  o   load and execute a series of SPMD and MPMD programs, in individual
      job steps, on the same partition.
 
  o   run non-parallel programs on remote nodes.
 
  The operation of POE is influenced by a number of POE environment
  variables. The flag options on this command are each used to
  temporarily override one of these environment variables. User
  program_options can be freely interspersed with the flag options, and
  additional_options not to be parsed by POE can be placed after a
  fence_string defined by the MP_FENCE environment variable. If no
  program is specified, POE will either prompt you for programs to load,
  or, if the MP_CMDFILE environment variable is set, will load the
  partition using the specified commands file.
 
  The environment variables and flags that influence the operation of
  this command fall into distinct categories of function. They are:
 
  o   Partition Manager control. The environment variables and flags in
      this category determine the method of node allocation, message
      passing mechanism, and the PULSE monitor function.
 
  o   Job specification. The environment variables and flags in this
      category determine whether or not the Partition Manager should
      maintain the partition for multiple job steps, whether commands
      should be read from a file or STDIN, and how the partition should
      be loaded.
 
  o   I/O control. The environment variables and flags in this category
      determine how I/O from the parallel tasks should be handled. These
      environment variables and flags set the input and output modes,
      and determine whether or not output is labeled by task id.
 
  o   VT trace collection. The environment variables and flags in this
      category determine if and how execution traces are collected for
      playback using the Visualization Tool (vt). They determine which
      types of traces are collected, and how trace storage is handled.
 
  o   Generation of diagnostic information. The environment variables
      and flags in this category enable you to generate diagnostic
      information that may be required by the IBM Support Center in
      resolving PE-related problems.
 
  o   Message Passing Interface. The environment variables and flags in
      this category enable you to specify values for tuning message
      passing applications.
 
  o   Miscellaneous. The additional environment variables and flags in
      this category enable additional error checking, and set a dispatch
      priority class for execution.
 
 
  ENVIRONMENT VARIABLES
 
  The environment variable descriptions in this section are grouped by
  function.
 
  The following environment variables are associated with Partition
  Manager control.
 
  MP_ADAPTER_USE      Determines how the node's adapter should be used.
                      If using LoadLeveler, the US communication
                      subsystem library does not require dedicated use
                      of the SP switch on the node. Adapter use will be
                      defaulted, as in Table 4 on page 2, but shared
                      usage may be specified. If using the Resource
                      Manager, this value is only used when POE is
                      requesting non-specific nodes via the MP_RMPOOL or
                      -rmpool setting. Valid values are dedicated and
                      shared. If not set, the default is dedicated for
                      US jobs, or shared for IP jobs. The value of this
                      environment variable can be overridden using the
                      -adapter_use flag.
 
  MP_AUTH             Determines the type of user authorization to be
                      used. Valid values are AIX (the default) for AIX
                      based user authorization, using /etc/hosts.equiv
                      or .rhosts entries, and DFS for DFS/DCE based
                      authorization. This value can be overridden with
                      an entry in the /etc/poe.limits file. There is no
                      associated command line flag.
 
  MP_CPU_USE          Determines how the node's CPU should be used. If
                      using LoadLeveler, the US communication subsystem
                      library does not require unique CPU use on the
                      node. CPU use will be defaulted, as in Table 4 on
                      page 2, but multiple use may be specified. If
                      using the Resource Manager, this value is only
                      used when POE is requesting non-specific nodes via
                      the MP_RMPOOL or -rmpool setting. Valid values are
                      multiple and unique. If not set, the default is
                      unique for US jobs, or multiple for IP jobs. The
                      value of this environment variable can be
                      overridden using the -cpu_use flag.
 
  MP_EUIDEVICE        Determines the adapter set to use for message
                      passing. Valid values are en0 (for Ethernet), fi0
                      (for FDDI), tr0 (for token-ring), and css0 (for
                      the SP system's high performance switch feature).
 
  MP_EUILIB           Determines the communication subsystem library
                      implementation to use for communication - either
                      the IP communication subsystem or the US
                      communication subsystem. In order to use the US
                      communication subsystem, you must have an SP
                      system configured with its high performance switch
                      feature.  Valid, case-sensitive, values are ip
                      (for the IP communication subsystem) or us (for
                      the US communication subsystem). The value of this
                      environment variable can be overridden using the
                      -euilib flag.
 
  MP_EUILIBPATH       Determines the path to the message passing and
                      communication subsystem libraries. This only needs
                      to be set if the libraries are moved. Valid values
                      are any path specifier. The value of this
                      environment variable can be overridden using the
                      -euilibpath flag.
 
  MP_HOSTFILE         Determines the name of a host list file for node
                      allocation. Valid values are any file specifier.
                      If not set, the default is host.list in your
                      current directory. The value of this environment
                      variable can be overridden using the -hostfile or
                      -hfile flags.
 
  MP_PROCS            Determines the number of program tasks. Valid
                      values are any number from 1 to 128. If not set,
                      the default is 1. The value of this environment
                      variable can be overridden using the -procs flag.
 
  MP_PULSE            The interval (in seconds) at which POE checks the
                      remote nodes to ensure that they are communicating
                      with the home node. The default interval is 600
                      seconds (10 minutes). To disable the pulse
                      function, specify an interval of 0 (zero) seconds.
                      The pulse function is automatically disabled when
                      running the pdbx or pedb debuggers. You can
                      override the value of this environment variable
                      with the -pulse flag.
 
  MP_REMOTEDIR        Specifies the name of a script which echoes the
                      name of the current directory to be used on the
                      remote nodes. By default, the current directory is
                      the current directory at the time that POE is run.
                      You may need to specify this if the AutoMount
                      Daemon is used to mount user file systems, and the
                      user is not using the Korn shell.
 
                      The script mpamddir is provided for mapping the C
                      shell directory name to an AutoMount Daemon name.
 
  MP_RESD             Determines whether or not the Partition Manager
                      should connect to LoadLeveler or the SP system
                      Resource Manager to allocate nodes. Valid values
                      are either yes or no, and there is no default. The
                      value of this environment variable can be
                      overridden using the -resd flag.
 
  MP_RETRY            Determines the period of time (in seconds) between
                      processor node allocation retries if there are not
                      enough processor nodes immediately available to
                      run a program. This is only valid if you are using
                      LoadLeveler or the SP system Resource Manager.
                      Valid values are any integer greater than or equal
                      to 0. The default is 0 (no retry). The value of
                      this environment variable can be overridden using
                      the -retry flag.
 
  MP_RETRYCOUNT       The number of times (at the interval set by
                      MP_RETRY) that the Partition Manager should
                      attempt to allocate processor nodes. Valid values
                      are any integer greater than or equal to 0. If not
                      set, the default is 0. The value of this
                      environment variable can be overridden using the
                      -retrycount flag.
 
  MP_MSG_API          Indicates to POE which message passing API is
                      being used by the parallel tasks. You need to set
                      this environment variable if a parallel task is
                      using LAPI alone or in conjunction with MPI. You
                      do not need to set it if a parallel task is using
                      MPI only. The value of this environment variable
                      can be overridden using the -msg_api flag.
 
  MP_RMPOOL           With regard to LoadLeveler, determines the name or
                      number of the pool that should be used for
                      non-specific node allocation. With regard to the
                      Resource Manager, determines the number of the SP
                      system pool that should be used for non-specific
                      node allocation. This environment
                      variable/command-line flag only applies to
                      LoadLeveler or the SP system Resource Manager.
                      Valid values are any identifying pool name or
                      number for LoadLeveler, and any identifying pool
                      number for the Resource Manager. There is no
                      default. The value of this environment variable
                      can be overridden using the -rmpool flag.
 
  MP_NODES            Specifies the number of physical nodes on which to
                      run the parallel tasks.  It may be used alone or
                      in conjunction with MP_TASKS_PER_NODE and/or
                      MP_PROCS, as described in Table 7 on page 3. The
                      value of this environment variable can be
                      overridden using the -nodes flag.
 
  MP_TASKS_PER_NODE   Specifies the number of tasks to be run on each of
                      the physical nodes. It may be used in conjunction
                      with MP_NODES and/or MP_PROCS, as described in
                      Table 7 on page 3, but may not be used alone. The
                      value of this environment variable can be
                      overridden using the -tasks_per_node flag.
 
  MP_SAVEHOSTFILE     The name of an output host list file to be
                      generated by the Partition Manager. Valid values
                      are any relative or full path name. The value of
                      this environment variable can be overridden using
                      the -savehostfile flag.
 
  MP_TIMEOUT          Controls the length of time POE waits before
                      abandoning an attempt to connect to the remote
                      nodes. The default is 150 seconds. MP_TIMEOUT also
                      changes the length of time the communication
                      subsystem will wait for a connection to be
                      established during message passing initialization.
 
  SP_NAME             Determines the job management system (LoadLeveler
                      or the SP system Resource Manager) to use. If all
                      nodes to be used for the parallel job exist in a
                      PSSP 2.4.0 partition, the SP_NAME environment
                      variable should be set to the name of the control
                      workstation of the SP system on which these nodes
                      exist. This is the only case that results in POE
                      contacting the Resource Manager rather than
                      LoadLeveler for node allocation requests. When
                      running POE from a workstation that is external to
                      the LoadLeveler cluster, the LoadL.so fileset must
                      be installed on the external node (see Using and
                      Administering LoadLeveler and IBM Parallel
                      Environment for AIX: Installation for more
                      information). When running POE from a workstation
                      that is external to the SP system, and using the
                      Resource Manager, the ssp.clients fileset must be
                      installed on the external node (see IBM Parallel
                      Environment for AIX: Installation for more
                      information).
 
  MP_CHECKFILE        Defines the base name of the checkpoint file when
                      checkpointing or restarting a program. See
                      "Checkpointing and Restarting Programs" on page 4
                      for more information.
 
  MP_CHECKDIR         Defines the directory where the checkpoint file
                      will reside when checkpointing or restarting a
                      program. See "Checkpointing and Restarting
                      Programs" on page 4 for more information.
 
  The following environment variables are associated with Job
  Specification.
 
  MP_CMDFILE          Determines the name of a POE commands file used to
                      load the nodes of your partition. If set, POE will
                      read the commands file rather than STDIN. Valid
                      values are any file specifier. The value of this
                      environment variable can be overridden using the
                      -cmdfile flag.
 
  MP_NEWJOB           Determines whether or not the Partition Manager
                      maintains your partition for multiple job steps.
                      Valid values are yes or no. If not set, the
                      default is no. The value of this environment
                      variable can be overridden using the -newjob flag.
 
  MP_PGMMODEL         Determines the programming model you are using.
                      Valid values are spmd or mpmd. If not set, the
                      default is spmd. The value of this environment
                      variable can be overridden using the -pgmmodel
                      flag.
 
  The following environment variables are associated with I/O Control.
 
  MP_LABELIO          Determines whether or not output from the parallel
                      tasks are labeled by task id. Valid values are yes
                      or no. If not set, the default is no. The value of
                      this environment variable can be overridden using
                      the -labelio flag.
 
  MP_STDINMODE        Determines the input mode - how STDIN is managed
                      for the parallel tasks. Valid values are:
 
                      all       all tasks receive the same input data
                                from STDIN.
 
                      none      no tasks receive input data from STDIN;
                                STDIN will be used by the home node
                                only.
 
                      n         STDIN is only sent to the task
                                identified (n).
 
                      If not set, the default is all. The value of this
                      environment variable can be overridden using the
                      -stdinmode flag.
 
  MP_HOLD_STDIN       Determines whether or not sending of STDIN from
                      the home node to the remote nodes is deferred
                      until the message passing partition has been
                      established. Valid values are yes or no. If not
                      set, the default is no.
 
  MP_STDOUTMODE       Determines the output mode - how STDOUT is handled
                      by the parallel tasks. Valid values are:
 
                      unordered all tasks write output data to STDOUT
                                asynchronously.
 
                      ordered   output data from each parallel task is
                                written to its own buffer. Later, all
                                buffers are flushed, in task order, to
                                STDOUT.
 
                      a task id only the task indicated writes output
                                data to STDOUT.
 
                      If not set, the default is unordered. The value of
                      this environment variable can be overridden using
                      the -stdoutmode flag.
 
  The following environment variables are associated with VT Trace
  Collection.
 
  MP_SAMPLEFREQ       Determines the interval (in milliseconds) at which
                      AIX kernel statistics are sampled when executing a
                      program with tracing on. Valid values are any
                      integer greater than or equal to 0. If not set,
                      the default is 10. The value of this environment
                      variable can be overridden using the -samplefreq
                      or -sfreq flags.
 
  MP_TBUFFSIZE        Determines the size (in bytes) of the buffer used
                      when generating trace files. This may be specified
                      as nnnK or nnnM. If not set, the default is 5M.
                      The value of this environment variable can be
                      overridden using the -tbuffsize or -tbsize flags.
 
  MP_TBUFFWRAP        Determines that a wraparound storage approach for
                      trace records should be used instead of the
                      default three-tiered approach. With this approach,
                      the system keeps overwriting the buffer instead of
                      flushing it to a temp file.  Valid values are
                      either yes or no. If not set, the default is no.
                      The value of this environment variable can be
                      overridden using the -tbuffwrap or -tbwrap flags.
 
  MP_TMPDIR           The temporary directory to which output trace
                      files are written. Valid values are any path
                      specifier. If not set, the default is
                      /tmp/username. The value of this environment
                      variable can be overridden using the -tmpdir flag.
 
  MP_TRACEDIR         Determines the directory to which the final
                      integrated trace file is built. Valid values are
                      any path specifier. If not set, the default is the
                      current directory. The value of this environment
                      variable can be overridden using the -tracedir or
                      -tdir flags.
 
  MP_TRACEFILE        Determines the name of the output trace file
                      created when executing a program with tracing on.
                      Valid values are any file specifier. If not set,
                      the default is the name of the program with the
                      suffix .trc added. The value of this environment
                      variable can be overridden using the -tracefile
                      and -tfile flags.
 
  MP_TRACELEVEL       Determines the level of VT tracing that should be
                      generated during the execution of a program. Valid
                      values are:
 
                      0  no trace records
 
                      1  Application Markers
 
                      2  AIX Kernel Statistic and Application Markers
 
                      3  Message Passing, Collective Communication, and
                         Application Markers
 
                      9  all trace records
 
                      If not set, the default is 0 (no trace records).
                      The value of this environment variable can be
                      overridden using the -tracelevel or -tlevel flags.
 
  MP_TTEMPSIZE        Determines the size (in bytes) of the temp file
                      used when generating trace files. This may be
                      specified as nnnM or nnnG. If not set, the default
                      is 10M. The value of this environment variable can
                      be overridden using the -ttempsize or -ttsize
                      flags.
 
  The following environment variables are associated with the generation
  of diagnostic information.
 
  MP_INFOLEVEL        Determines the level of message reporting. Valid
                      values are:
 
  0    error
 
  1    warning and error
 
  2    informational, warning, and error
 
  3    informational, warning, and error. Also reports diagnostic
       messages for use by the IBM Support Center.
 
  4, 5, 6 Informational, warning, and error. Also reports high- and
       low-level diagnostic messages for use by the IBM Support Center.
 
  If not set, the default is 1 (warning and error). The value of this
  environment variable can be overridden using the -infolevel or -ilevel
  flags.
 
  MP_PMDLOG           Determines whether or not diagnostic messages
                      should be logged to a file in /tmp on each of the
                      remote nodes. Typically, this environment
                      variable/command-line flag is only used under the
                      direction of the IBM Support Center in resolving a
                      PE-related problem. Valid values are yes or no. If
                      not set, the default is no. The value of this
                      environment variable can be overridden using the
                      -pmdlog flag.
 
  MP_DEBUG_LOG        Determines the level of diagnostic messages
                      written to $MP_tmp/dbelog.pid.taskid. Typically,
                      this environment variable/command-line flag is
                      only used under the direction of the IBM Support
                      Center in resolving a PE-related problem. This
                      environment variable has no associated
                      command-line flag.
 
  MP_DEBUG_INITIAL_STOP
                      Determines the initial breakpoint in the
                      application where pdbx or pedb will get control.
                      MP_DEBUG_INITIAL_STOP should be specified as
                      file_name:line_number. The line_number is the
                      number of the line within the source file
                      file_name; where file_name has been compiled with
                      -g. The line number has to be one that defines
                      executable code. In general, this is a line of
                      code for which the compiler generates machine
                      level code. Another way to view this is that the
                      line number is one for which debuggers will accept
                      a breakpoint.  Another valid string for
                      MP_DEBUG_INITIAL_STOP would be the function_name
                      of the desired initial stopping point in the
                      debugger. If this variable is not specified, the
                      default is to stop at the first executable source
                      line in the main routine. This environment
                      variable has no associated command-line flag.
 
  MP_PMDSUFFIX        When using LoadLeveler, this environment variable
                      determines a string to be appended to the normal
                      partition manager daemon executable. The normal
                      partition manager daemon executable specified is
                      /etc/pmdv2. By setting MP_PMDSUFFIX, you can
                      append a string to pmdv2. If MP_PMDSUFFIX is set
                      to abc, for example, then the partition manager
                      daemon that gets run on each node of the parallel
                      task is /etc/pmdv2abc. When using the Resource
                      Manager, this environment variable determines a
                      string to be appended to the normal tcp service.
                      The normal tcp service specified in /etc/services
                      is named pmv2.  By setting MP_PMDSUFFIX, you can
                      append a string to pmv2. If MP_PMDSUFFIX is set to
                      abc, for example, then the service requested in
                      /etc/services is pmv2abc. Using the environment
                      variable with LoadLeveler or the Resource Manager
                      as described above permits testing of alternate
                      versions of the Partition Manager daemon.
                      Typically, this environment variable is only used
                      under the direction of the IBM Support Center in
                      resolving a PE-related problem. Valid values are
                      any string. This environment variable has no
                      associated command-line flag.
 
  The following environment variables are associated with the Message
  Passing Interface.
 
  MP_BUFFER_MEM       Changes the maximum size of memory used by the
                      communication subsystem to buffer early arrivals.
                      The default is 2.8 megabytes for IP and 64
                      megabytes for US.  However, if checkpointing a
                      program, for US the default will be 2.8 megabytes.
                      If you are using this environment variable to
                      change the maximum size of memory used by the
                      communication subsystem while checkpointing a
                      program, please be aware that the amount of space
                      needed for the checkpointing files will be
                      increased by the value of MP_BUFFER_MEM.
 
  MP_CSS_INTERRUPT    Determines whether or not arriving message packets
                      cause interrupts. This may provide better
                      performance for certain applications. Valid values
                      are yes and no. If not set, the default is no.
 
  MP_EAGER_LIMIT      Changes the threshold value for message size,
                      above which rendezvous protocol is used.
 
  MP_INTRDELAY        Allows user programs to tune the delay parameter
                      without having to recompile existing applications.
 
  MP_MAX_TYPEDEPTH    Changes the maximum depth of message buffer types.
 
  MP_USE_FLOW_CONTROL Limits the maximum number of outstanding messages
                      posted by a sender.
 
  MP_THREAD_STACKSIZE Determines the additional stacksize allocated for
                      user programs executing on an MPI service thread.
                      If you allocate insufficient space, the program
                      may encounter a SIGSEGV exception.
 
  MP_SINGLE_THREAD    Avoids mutex lock overheads in a single threaded
                      program. This is an optimization flag, with values
                      of no and yes. The default value is no, which
                      means multiple user message passing threads are
                      assumed.
 
  Note:  MPI-IO cannot be used if this is set to YES. Results are
         undefined if this is YES, with multiple message passing threads
         in use.
 
  MP_WAIT_MODE        Determines how a thread or task behaves when it
                      discovers it is blocked, waiting for a message to
                      arrive. Values are poll, yield, and sleep. The
                      default mode for the signal handling library is
                      poll for US, and sleep for IP.
 
  MP_POLLING_INTERVAL Defines the polling interval in microseconds. The
                      maximum interval is approximately 2 billion
                      microseconds (2000 seconds). The default is
                      180,000 microseconds for IP, and 400,000
                      microseconds for US.
 
  The following are miscellaneous environment variables:
 
  MP_EUIDEVELOP       Determines whether or not the message passing
                      interface performs more detailed checking during
                      execution. This additional checking is intended
                      for developing applications, and can significantly
                      slow performance. Valid values are yes or no, deb
                      (for "debug"), nor (for "normal"), and min (for
                      "minimum") . The debug and min values are used to
                      start and stop parameter checking. If not set, the
                      default is no. The value of this environment
                      variable can be overridden using the -euidevelop
                      flag.
 
  MP_FENCE            Determines a fence_string to be used for
                      separating options you want parsed by POE from
                      those you do not. Valid values are any string, and
                      there is no default. Once set, you can then use
                      the fence_string followed by additional_options on
                      the poe command line. The additional_options will
                      not be parsed by POE. This environment variable
                      has no associated command-line flag.
 
  MP_NOARGLIST        Determines whether or not POE ignores the argument
                      list. Valid values are yes and no. If set to yes,
                      POE will not attempt to remove POE command-line
                      flags before passing the argument list to the
                      user's program. This environment variable has no
                      associated command-line flag.
 
  MP_PMLIGHTS         Indicates the number of lights displayed per row
                      on the Program Marker Array.
 
  MP_PRIORITY         Determines a dispatch priority adjustment class
                      for execution. See IBM Parallel Environment for
                      AIX: Installation for more information on dispatch
                      priority classes. Valid values are any of the
                      dispatch priority classes set up by the system
                      administrator in the file /etc/poe.priority. This
                      environment variable has no associated
                      command-line flag.
 
  MP_USRPORT          Indicates the port id used by the Partition
                      Manager to connect to the Program Marker Array. By
                      default, the Partition Manager connects to the
                      Array using a socket assigned to port 9999. If you
                      get an error message indicating that the port is
                      in use, specify a different port. Standard TCP/IP
                      practice suggests using ports greater than 5000
                      and less than 10000.
 
  MP_COREDIR          Creates a separate directory for each task's core
                      file.
 
 
  EXAMPLES
 
  1.  Assume the MP_PGMMODEL environment variable is set to spmd, and
      MP_PROCS is set to 6. To load and execute the SPMD program sample
      on the six remote nodes of your partition, enter:
 
        poe sample
 
  2.  Assume you have an MPMD application consisting of two programs -
      master and workers. These programs are designed to run together
      and communicate via calls to message passing subroutines. The
      program master is designed to run on one processor node. The
      workers program is designed to run as separate tasks on any number
      of other nodes. The MP_PGMMODEL environment variable is set to
      mpmd, and MP_PROCS is set to 6. To individually load the six
      remote nodes with your MPMD application, enter:
 
        poe
 
      Once the partition is established, the poe command responds with
      the prompt:
 
        0:host1_name>
 
      To load the master program as task 0 on host1_name, enter:
 
        master
 
      The poe command responds with a prompt for the next node to load.
      When you have loaded the last node of your partition, the poe
      command displays the message "Partition loaded..." and begins
      execution.
 
  3.  Assume you want to run three SPMD programs - setup, computation,
      and cleanup - as job steps on the same partition of nodes. The
      MP_PGMMODEL environment variable is set to spmd, and MP_NEWJOB is
      set to yes. You enter:
 
        poe
 
      Once the partition is established, the poe command responds with
      the prompt:
 
        Enter program name (or quit):
 
      To load the program setup, enter:
 
        setup
 
      The program setup executes on all nodes of your partition. When
      execution completes, the poe command again prompts you for a
      program name.  Enter the program names in turn. To release the
      partition, enter:
 
        quit
 
  4.  To check the process status (using the non-parallel command ps)
      for all remote nodes in your partition, enter:
 
        poe ps
 
 
  FILES
 
  host.list (Default host list file)
 
 
  RELATED INFORMATION
 
  Commands: mpcc(1), mpcc_r(1), mpCC(1), mpCC_r(1), mpxlf(1),
  mpxlf_r(1), pdbx(1), pedb(1), pmarray(1), vt(1), xprofiler(1)