The HPM Toolkit at NCSA

Overview
Individual Components
NCSA-Specific Information
Basic Usage
Documentation

Overview

The Hardware Performance Monitor (HPM) Toolkit from IBM's Advanced Computing Technology Center (ACTC) is available on NCSA's IBM p690 system (Copper). The toolkit contains utilities and a library that allow you to access the hardware performance counters on the processor in order to accurately measure the performance of your application. It can be used with both serial and parallel applications. HPM Toolkit was developed by Luiz DeRose of ACTC.

The official IBM web site for the HPM Toolkit is located at:



http://www.alphaworks.ibm.com/tech/hpmtoolkit/

Components of the HPM Toolkit

The HPM Toolkit consists of three components:

hpmcount: A command-line utility that you can invoke on an unmodified executable (no source code changes, recompilation, or relinking required) to measure several types of hardware performance events for your application as a whole. Performance counter access is implemented through direct calls to the PMAPI kernel interface on AIX.
libhpm: A library (callable from Fortran, C, and C++) that enables you to selectively control the collection of hardware performance data by inserting calls to the library at appropriate points in your application source.
hpmviz: A visualization utility that allows you to graphically browse the output of a program instrumented with libhpm. You must use the libhpm library, not hpmcount, to obtain input files suitable for use with hpmviz.

NCSA-Specific Information

The HPM Toolkit is installed on NCSA's p690 systems in the directory:

/usr/apps/tools/hpm

On the p690, the most recent version of the toolkit is available through a symbolic link "hpm", for example:

/usr/apps/tools/hpm/hpm/pwr4/bin/hpmcount a.out

HPM utilities (hpmcount, hpmviz) are located under the subdirectory arch/bin, include files for libhpm routines under include, and the HPM libraries themselves under arch/lib (arch is dependent on the system you're using and will be pwr4 on the p690).

Basic Usage of hpmcount

The easiest way to take advantage of the HPM Toolkit is to simply invoke hpmcount, supplying your executable (and any arguments that it accepts) on the command line. For example,

    copper % hpmcount myprog

By default (on AIX), this will count and report a number of statistics relating to floating-point operations and loads/stores executed by myprog. hpmcount provides several other pre-defined performance events that may be of interest; you can obtain a listing of these event sets (as well as other options accepted by hpmcount) by checking the utility's help message, as follows:

    copper % hpmcount -h

Complete information about using hpmcount is available in the reference manual (see below).

Documentation

The HPM Toolkit includes the HPM Toolkit Reference Manual that you can read online to learn more about the capabilities and use of this software.

You may also find a technical report describing the use of the HPM Toolkit written by Joachim Hein of EPCC/University of Edinburgh to be helpful in understanding this performance analysis software: Using the Hardware Performance Monitor Toolkit on HPCx.