Monitoring Program Performance

GPROF is a directory of FORTRAN90 programs which illustrate the use of the GPROF program performance monitoring utility.

In order to use GPROF with a FORTRAN90 program, the user program must be compiled and linked with the -pg switch. For example, either

        gfortran -pg myprog.f90
or, in a two step process,

        gfortran -c -pg myprog.f90
        gfortran -pg myprog.o
When the resulting executable program is run, GPROF will silently monitor the program, and produce a report file called gmon.out. This report file is not user-readable. To see the information contained in the report, you have to run gprof and tell it the name of the executable program you just ran. A typical procedure, then, would be to issue the commands

        a.out            (to run your program)
        gprof a.out      (to have GPROF make the report)

GPROF can only report on code which has been compiled with the appropriate options. If your program calls routines from a precompiled library (which probably was NOT compiled with the -pg option!) then your report information will not include information about the time spent in those routines. GPROF's report will charge all such time to the higher level routine that called the library routine. If most of your execution time occurs in various library routines, then this fact may greatly reduce the value of GPROF's information.

For more information on how to use GPROF, type

        man gprof


The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.


GPROF examples are available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version.

Examples and Tests:

The LINPACK BENCHMARK code solves a linear system. This program was compiled, run, and analyzed with GPROF. Files you may copy include:

You can go up one level to the FORTRAN90 source codes.

Last revised on 09 March 2008.