How to debug high CPU usage?

Question

What tools to use to find out what cause a high CPU usage in .net application?

WPF / C# 3.0 / .net 3.5

Answer 1

Apply a profiler to understand where the CPU is being used: what parts of your code are "hot". You can then review the design of those parts of the code.

Note, the high CPU usage could be completely reasonable.