Setting up event-based sampling
In Streamline, you can override the default interval sampling with event-based sampling using the Counter Configuration dialog box.
To enable event-based sampling, follow these steps:
- Open the Counter Configuration dialog box using the button in the Streamline Data view.
- Select an event from the Events to Collect list.
Click the Toggle event-based
sampling button on the right side of the dialog box.
If the Toggle event-based sampling button is not selectable after you have selected an event, then that event does not support event-based sampling.
Enter a value in the newly activated Threshold
Avoid setting a very low threshold for high frequency events. If you enter a threshold value that generates too many samples, the capture could fail, and you might have to restart your target. To find an appropriate value to enter in the Threshold field, turn off event-based sampling to run a standard, time-based profile with the event counter that you want to use enabled. Look at the resulting Timeline view and note the peak per-second value in the chart for your counter. Your target for the Threshold field is 1000 samples per second, so if the peak for that event is 2000000, a good value to insert in the Threshold field is 2000.
Figure 4-4 Setting up event-based sampling