Parallel Programming Guide for HP-UX Systems

MPI

Proﬁling

Chapter 2 71

Proﬁling

The following provides information about utilities you can use to analyze

HP MPI applications. The topics covered are:

• Using counter instrumentation

— Creating an instrumentation proﬁle

— Viewing ASCII instrumentation data

• Using the proﬁling interface

Using counter instrumentation

Counter instrumentation is a lightweight method for generating cumulative runtime

statistics for your MPI applications. When you create an instrumentation proﬁle, HP MPI

creates an ASCII format.

You can create instrumentation proﬁles for applications linked with the standard HP MPI

library, and for applications linked with HP MPI version 2.0, you can also create proﬁles for

applications linked with the thread-compliant library. Instrumentation is not supported for

applications linked with the diagnostic library (-ldmpi).

Creating an instrumentation proﬁle

Create an instrumentation proﬁle using one of the following methods:

• Use the following syntax:

mpirun -i

spec

-np #

program

For example, to create an instrumentation proﬁle for an application called compute_pi.f,

enter:

% $MPI_ROOT/bin/mpirun -i compute_pi -np 2 compute_pi

This invocation creates an instrumentation proﬁle in the following format:

compute_pi.instr (ASCII).

• Specify a ﬁlename preﬁx using the MPI_INSTR environment variable. For example,

% setenv MPI_INSTR

compute_pi

Speciﬁes the instrumentation output ﬁle preﬁx as compute_pi.