I built a similar system with a focus on profiling events with extremely low overhead. When taking an timestamp, the processor cycle count register is read, and

I built a similar system with a focus on profiling events with extremely low overhead. When taking an timestamp, the processor cycle count register is read, and pushed into a ring buffer with a tiny descriotion including a static string label. A background thread perodically writes that buffer contents to disk. An offline tool visualizes the recorded events and intervals over time and can do a bit of statistics. This system has served me quite well, but I need to rework the UI because zooming to microsecond resolution on a 30 second trace overflows the range values in the Qt scrollbars.