Intel(R) MPI Library Developer Reference for Linux* OS

Developer Reference

Contents

mpitune

Tunes the Intel® MPI Library parameters for the given MPI application.

Syntax

mpitune <options>

Arguments

<mpitune options>
Options
-c | --config-file <file>
Specify a configuration file to run a tuning session.
-d | --dump-file <file>
Specify a file that stores the collected results. The option is used in the
analyze
 mode.
-m | --mode {collect | analyze}
Specify the
mpitune
 mode. The supported modes are
collect
 and  
analyze
:
  • the  
    collect
     mode runs the tuning process and saves results in temporary files;
  • the  
    analyze
     mode transforms temporary files into a JSON-tree, which is used by the Intel® MPI Library, and generates a table that represents algorithm values in a human-readable format.
-h | --help
Display the help message.
-v | --version
Display the product version.

Description

The
mpitune
 utility allows you to automatically adjust Intel® MPI Library parameters, such as collective operation algorithms, to your cluster configuration or application.
The tuner iteratively launches a benchmarking application with different configurations to measure performance and stores the results of each launch. Based on these results, the tuner generates optimal values for the parameters being tuned.
Starting with the Intel® MPI Library Update 4 release, you must specify two
mpitune
 configuration files, which differ in their
mode
 and
dump-file
 fields. A simpler alternative may be to use one of the single configuration file templates shipped with the Intel MPI Library. In this case, you must use the command line to define the
mode
 and
dump-file
 fields.
  • The
    -mode
     option defines one of two possible MPI tune modes:
    collect
     or
    analyze
    .
  • The
    -dump-file
     option defines the path to the temporary files when in
    analyze
     mode. This path is returned by
    mpitune
     after the first iteration.
The configuration files should specify all tuner parameters, which are passed to the tuner with the
--config-file
 option. A typical configuration file consists of the main section, specifying generic options, and search space sections for specific library parameters (for example, for specific collective operations). To comment a line, use the hash symbol
#
.  All configuration file examples are available at
<installdir>/etc/tune_cfg
. Please note that configuration files for Intel® MPI Benchmarks are already created.
The tuning process consists of two steps: data collection (the
collect
 mode) and data analysis (the
analyze
 mode): 
$ mpitune -m collect -c /path/to/config_file2
$ mpitune -m analyze -c /path/to/config_file1
Another variant of the launch is:
$ mpitune -m analyze -c /path/to/config_file1
where the path to the dump-file received in the first step is used in the config file with templates inside.
The tuning results are presented as a JSON tree and can be added to the library with the
I_MPI_TUNING environment variable.
MPI Options Support
The following MPI options are available within the utility:
<MPI options>
Options
-f
<filename>
Specify a file containing host names.
-hosts
<hostlist>
Specify a comma-separated list of hosts.
-np
<value>
Specify the number of processes.

Examples

$ mpitune -np 2 -ppn 1 -hosts HOST1,HOST2 -m collect -c /path/to/config_file2
$ mpitune -np 2 -ppn 1 -hosts HOST1,HOST2 -m analyze -c /path/to/config_file1

See Also

MPI Tuning in the
Developer Guide
For available configuration options, refer to mpitune Configuration Options.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.