PAPI: Performance Application Programming Interface

===================================================

** Innovative Computing Lab **

** University of Tennessee, Knoxville, TN **

***

[TOC]

***

About

-----

PAPI provides the tool designer and application engineer with a

consistent interface and methodology for use of the performance

counter hardware found in most major microprocessors. PAPI enables

software engineers to see, in near real time, the relation between

software performance and processor events.

In addition, PAPI provides access to a collection of components that

expose performance measurement opportunites across the hardware and

software stack.

Getting Started

---------------

If this is the first file you've opened in the PAPI tree, we'll try to give you

a few tips on where to go from here.

* Read the license found in LICENSE.txt. It's pretty short, and not very 

  restrictive, but it'll give you an idea of what you can and can't do with the

  PAPI sources.

* Visit the website at: <http://icl.utk.edu/papi>

  There you can find late-breaking news that may be more current than in these

  files. You can also find documentation in a greater variety of formats than

  in the papi/doc/ directory.

* Sign up for the PAPI mailing list(s). Instructions are on our home page.

* Read the RELEASENOTES.txt file to get an idea of what's new in the current release.

Installing PAPI

---------------

To install PAPI on your system:

* Find the section in INSTALL.txt that pertains to your hardware and operating

  system.

* Follow the directions to install required components and build the PAPI

  libraries.

* Run the test suite when you are finished to verify that everything went ok.

  NOTE: Although we make every attempt to get all tests to PASS or SKIP on all

  platforms, there are occasional instances of FAILures due to excessively 

  tight compliance thresholds or platform idiosyncrasies. Don't panic if one

  or two tests FAIL. Contact us with complete output and we'll see what we can do.

Using PAPI

----------

To use PAPI in your own programs:

* Read the PAPI Overview found at:

	http://icl.utk.edu/projects/papi/wiki/Main_Page.

* Try out the utility programs in /utils to see what's in your system.

* Try a test program. Source for a number of tests in both C and FORTRAN is

  available in the src/tests/ and src/ftests/ directories. Find a program

  that's similar to what you want to do. Make sure you can build it and run it.

* Write a test program of your own, exercising the PAPI events and features of

  interest to you.

* Go for broke. Fold PAPI calls into your sources and see what you can learn.

Bugs and Questions

------------------

* Visit our FAQ at: <http://icl.utk.edu/papi/faq/>

  or read a snapshot of the FAQ in papi/PAPI_FAQ.html

* Subscribe to the PAPI mailing list at:

  <https://groups.google.com/a/icl.utk.edu/forum/#!forum/ptools-perfapi>

* Read historical postings to the list.

* Post questions to the list.