Unexpected Paused Time in VTune(TM) Amplifier XE results

You may see "paused" time in the VTune(TM) Amplifier XE timeline display even though you did not add any calls to the __itt_pause() API.  For example:

This can happen when collecting call stacks with event-based sampling (EBS). Now, in the above example, the application called __itt_pause() at about the 22 sec mark. But the other, smaller pauses were inserted by the VTune Amplifier XE, which temporarily pauses profiling when data generation rate exceeds data spill rate and it's about to lose data. The data is flushed and then collection resumes.  In the paused regions, your app is not executing: VTune Amplifier XE lets the app exhaust its current quanta and then prevents it from being scheduled on the CPU until all the data has been saved to file. Therefore, you can ignore this injected paused time.

For example, in the Summary information below, you can see that Paused Time is part of the Elapsed Time, but is not included in CPU Time.

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