Analyze Interrupts
If you configured your collection to monitor IRQ Ftrace* events either by using the
System Overview analysis type or
custom analysis, the
Intel® VTune™
analyzes code performance inside IRQs and displays interrupts statistics in the default Hardware Events viewpoint. Follow the steps below to analyze the collected interrupt data:
Profiler
Identify Critical Interrupt Handlers
Start your analysis with the
Summary
window that provides overall interrupt handlers statistics in the following sections:
- Top Interrupt Handlersthat shows the most active interrupt handlers sorted by Interrupt Time.
Clicking an interrupt handler in the list opens the grid view grouped byInterrupt/Interrupt Duration Type/Function/Call Stacklevel. - Interrupt Duration Histogramthat shows a distribution of interrupt handler instances per duration types defined by theVTune. High number of slow instances may signal a performance bottleneck. Use the drop-down menu to view data for different interrupt handlers.Profiler
When you identified a slow interrupt in the
Summary
window, you may switch to the
Event Count
tab sorted by the
Interrupt/..
level, locate this interrupt, expand the hierarchy to view a function where slow interrupts occurred, and double-click the function to explore its source code in the Source view.
Analyze Slow Interrupts on the Timeline
Switch to the
Platform
tab in the
Hardware Events
viewpoint to analyze CPU utilization, GPU usage and power consumption during your code execution and correlate this data with the time frames when slow interrupts occurred. You may enable the
Slow Interrupts
markers on the timeline, select a time frame with slow interrupts and zoom in to the selected region for detailed analysis:
