Developer Guide

Tracing Applications

The Intel® MPI Library provides a variety of options for analyzing MPI applications. Some of these options are available within the Intel MPI Library, while some require additional analysis tools. For these tools, the Intel MPI Library provides compilation and runtime options and environment variables for easier interoperability.
The Intel MPI Library is tightly integrated with the Intel® Trace Analyzer and Collector, which enables you to analyze and debug MPI applications. The Intel MPI Library has several compile-time options to simplify the application analysis.
Intel Trace Analyzer and Collector is available as standalone software and as part of the Intel® oneAPI HPC Toolkit. Before proceeding to the next steps, make sure you have the product installed.

Trace an Application

To analyze an application, first you need generate a trace file of your application, and then open this file in Intel® Trace Analyzer to analyze communication patterns, time utilization, etc. Tracing is performed by
linking with
the Intel Trace Collector profiling library, which intercepts all MPI calls and generates a trace file. Intel MPI Library provides the
-trace
(
-t
)
compiler
option to simplify this process.
Complete the following steps:
  1. Set up the environment for the
    compiler,
    Intel MPI Library, and Intel Trace Analyzer and Collector.
    > run <compiler-install-dir>\env\vars.bat
    > run <itac-install-dir>\env\vars.bat
  2. Relink
    your application with the Intel Trace Collector
    profiling library and run the application
    :
    > mpiicc -trace myprog.c > mpiexec -n 4 myprog.exe
    As a result, a trace file
    .stf
    is generated. For the example above, it is
    myprog.stf
    .
  3. Analyze the application with the Intel Trace Analyzer:
    > traceanalyzer myprog.stf
The workflow above is the most common scenario of tracing with the Intel Trace Collector. For other tracing scenarios, see the Intel Trace Collector documentation.

Product and Performance Information

1

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