These are some examples of using the perf Linux profiler, which has also been called Performance Counters for Linux (PCL), Linux perf events (LPE), or perf_events. Like Vince Weaver, I'll call it perf_events so that you can search on that term later.

Timechart is a tool, based on 'perf', that has the objective to show on a system level what is going on, at various levels of detail, with the Linux system performance.