TAU

The TAU performance system relies on measured instrumentation to support both profiling and tracing performance models. The TAU framework architecture is organized into three layers - instrumentation, measurement and analysis - where within each layer multiple modules are available and can be configured to suit user needs. TAU supports a flexible instrumentation model that allows the user to insert performance instrumentation using the measurement API at different levels of program code representation, compilation, transformation, linking and execution. The key concept of the instrumentation layer is the definition of performance events. It supports several types of performance events to characterize program performance. Events describing a region of code such as routines, basic blocks or loops use a pair of markers to start and stop timers. Atomic user-defined events take place at a given point in the code and are triggered with some application level data (such as the size of message transmitted, the size of memory allocated etc.).