Performance Application Programming Interface: Difference between revisions

Revision as of 03:20, 11 October 2006

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In [[computer science]], Performance Application Programming Interface (PAPI) is a portable interface (in form of library) to hardware performance counters on modern [[microprocessor]]s. It is being widely used to collect low level performance metrics (e.g. instruction counts, clock cycles, cache misses) of computer systems running [[UNIX]]/[[Linux]] [[operating system]]s.

PAPI provides predefined high level hardware events summarized from popular processors and direct access to low level native events of one particular processor. Counter multiplexing isand overflow handling are also supported.

Operating system support for accessing hardware counters is needed to use PAPI. For example, a Linux/x86 kernel has to be patched with a performance monitoring counters driver (perfctr [http://user.it.uu.se/~mikpe/linux/perfctr/ link]) to support PAPI.