Use the TIME-WINDOWS option to set up time frames within which Intel® Trace Collector will save the events into the trace file.

You can have several time frames at the same run.

To set time windows for Intel Trace Collector to collect trace data for the poisson application from 0 to 28 milliseconds only, do the following:

  1. Create a new configuration file.
  2. To get the correct order of messages in the output trace file, include the first communication into the first time window.
  3. For the poisson application, set up the time frame from 0 to 28 milliseconds using the following syntax (the lower-case "L" character stands for milliseconds):

    TIME-WINDOWS 0:28l

    For more information about the syntax of parameters, refer to the Intel® Trace Collector User and Reference Guide.

  4. Save the configuration file as my_settings_timewindows.conf.

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

    VT_CONFIG=/<configuration file path name>/my_settings_timewindows.conf
  6. Run the application.

    Linux* OS:

    $ mpirun -trace -n 4 ./poisson

    Windows* OS:

    > mpiexec -n 4 poisson.exe

Check the resulting trace file:

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

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

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

  4. Go to Charts > Time Scale or press the toolbar button to open the time scale.

You can see that the total execution time has been written into the trace file, but the trace data is collected only for the specified period of time (28 milliseconds). The VT_API group stands for the part of the code where trace data collection was off:

Key Terms

Configuration File
Event Timeline
Function Profile

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