7 Managing Measurement Overhead

The simplest way to reduce the overhead caused by PPW is try compiling your program without using the --inst-functions or --inst-local compilation flags. If this does not solve your problem, or if it eliminates too much useful performance information, read on.

Aside from the compilation flags mentioned above, PPW provides two methods of controlling overhead in your program: selective instrumentation, and selective measurement.

• Selective Instrumentation: Controlling the instrumentation process
• Selective Measurement: Controlling measurement during runtime
• Using Selective File: Controlling measurment by excluding specific events
• Throttling: Dynamically reducing overhead at runtime