Generate a Trace File

 To check how the configuration file influences the trace collection process, run four processes of the poisson sample code with the following configuration file:

  1. Create a new configuration file.

  2. Type in the following parameters:

    STATE MPI:*Allreduce* ON
  3. Save the configuration file, for example, filter.conf.

  4. Set the VT_CONFIG environment variable to the directory that contains the configuration file:

  5. Run the application.

    Linux* OS:

    $ mpirun -trace -n 4 ./poisson

    Windows* OS:

    > mpiexec -n 4 poisson.exe

To check the results, do the following:

Check your work:

  1. Open the resulting trace file poisson.single.stf in Intel® Trace Analyzer.

  2. In the Function Profile, right-click Group MPI and select Ungroup Group MPI from the context menu.

  3. Go to the Load Balance tab of the Function Profile to see how the MPI_Allreduce function is distributed among the four processes.

  4. Go to Charts > Event Timeline to see the activities in each of the four processes individually.

The result looks like:

You can see that the trace data was collected only for the MPI_Allreduce function.

Key Terms

Configuration File
Event Timeline
Function Profile

For more complete information about compiler optimizations, see our Optimization Notice.