Method and system for zero overhead software performance measurement instrumentation

• Main Authors: Berry, Robert Francis, Bryant, Raymond Morris
• Format: Patent
• Language: English
• Published: 02.12.2003

1. Field of the Invention A method, system, and computer program product is presented for minimizing overhead that may be incurred by executing specialized code, such as debug code or instrumentation code for monitoring the performance of the application, that is present within an application. The application executes on a data processing system having a processor containing predicate registers. The application is compiled in a manner in which the processor instructions for the specialized code are predicated using a set of one or more predicate registers that are dedicated or reserved by software convention for predicating the specialized code. In other words, for a given application, compilers and other sources of machine instructions do not generate any predicated processor instructions, other than processor instructions for the specialized code, which use the reserved predicate registers. When the application executes, neither the operating system nor other applications use the reserved predicate registers. An operating system function can be called or invoked to set the values of the reserved predicate registers so that the specialized code either does or does not execute in a chosen manner. Alternatively, the processor contains a set of special predicate registers that are reserved for predicating instrumentation code rather than protecting a set of predicate registers through software convention.