PAPI is an acronym for Performance Application Programming Interface. The PAPI project originated at the University of Tennessee’s Innovative Computing Laboratory, now part of the Department of Electrical Engineering and Computer Science. This project was initiated more than a decade ago to design, standardize, and implement a portable and efficient API to access the hardware performance counters found on modern microprocessors. With the introduction of Component PAPI, or PAPI-C in early 2010, PAPI has extended its reach beyond the CPU and can now monitor system information on a range of components from CPUs to network interface cards to power monitors and more.
PAPI provides machine and operating system independent access to performance counters. Any of over 100 preset events can be counted through either a simple high level programming interface or a more complete low level interface from either C or Fortran. Please see PAPI documentation for further details.