Minimizing Data Collection, Result Size, and Execution Time (Survey)

For medium-large targets, several methods are available to minimize the amount of data collected and target execution time. Minimizing the data collected reduces the amount of data you need to examine in the Survey Report; it also reduces the size of the generated result.

The Survey tool recognizes only two annotations:

• Pause Collection: Stops data collection to skip uninteresting parts of the target program's execution. This minimizes the data collected and speeds up the analysis of medium-large applications.

• Resume Collection: Resumes data collection previously paused to collect data about the interesting parts of your program.

The Survey and Suitability tools provide several ways to start target execution with data collection paused or paused for a specified time: from the GUI, using an Intel Advisor Option, or a command-line option. Starting collection paused for a specified time lets you automatically skip data/program initialization and related setup steps without modifying your source code. Starting collection paused (without a time) lets you automatically skip data/program initialization and related setup steps but your target needs to execute a Resume Collection annotation.

The Survey and Suitability tools also provide Pause and Resume (collection) buttons in the side command toolbar that are equivalent to executing the Pause Collection and Resume Collection annotations. You might use these GUI buttons instead of the annotations in certain cases, such as your initial profiling runs.

The recommended method is to:

• Start the tool and target execution using one of the following:

  • Click the Start Paused button on the side command toolbar. To hide or show the command toolbar, click the or button in the upper-right of the Survey Report.

  • Before you run the tool, set the equivalent Project Property in the Intel Advisor GUI under AdvancedResume collection after, ms to start collection paused for a specified time.

  • On the command line, use --collect with either the --start-paused or --resume-after options.

• If you used the Start Paused button or --start-paused option, execute the Resume Collection annotation to begin data collection of the first interesting part of the program.

• Execute pairs of Pause Collection and Resume Collection annotations to collect data about the interesting part(s) of the target program. Place Pause Collection and Resume Collection annotations outside the parallel site begin and parallel site end annotations.

When using the Intel® Advisor GUI, you can specify Project Properties for the Sampling interval and the Duration time estimate, which are Advanced options. You should provide a Duration time estimate if the target's execution takes multiple hours, because this can increase the Sampling interval used during data collection to minimize result size. You can also directly adjust the Sampling interval:

• To minimize excessive result size, increase the Sampling interval.

• To increase the accuracy of collected data (and result size), reduce the Sampling interval.