What Makes These Tools Possible?
Performance Analyzer is built on top of the Event Tracing for Windows (ETW) infrastructure. ETW enables Windows and applications to efficiently generate events, which can be enabled and disabled at any time without requiring system or process restarts. ETW collects requested kernel events and saves them to one or more files referred to as "trace files" or "traces." These kernel events provide extensive details about the operation of the system. Some of the most important and useful kernel events available for capture and analysis are context switches, interrupts, deferred procedure calls, process and thread creation and destruction, disk I/Os, hard faults, processor P-State transitions, and registry operations, though there are many others.
One of the great features of ETW, supported in WPT, is the support of symbol decoding, sample profiling, and capture of call stacks on kernel events. These features provide very rich and detailed views into the system operation. WPT also supports automated perf testing. Specifically, xperf is designed for scripting from the command line and can be employed in automated performance gating infrastructures (it is the core of Windows PerfGates). xperf can also dump the trace data to an ANSI text file, which allows you to write your own trace processing tools that can look for performance problems and regressions from previous tests.