I'm running into a little problem and require some assistance. I would like to run gprof on some OpenMP and MPI hybrid code as a part of my testing. I understand that Gprof relies on a binary file which is created when you compile GCC (or mpicc) with a -pg switch.
I have tried adding this switch and my compiling succeeds (as in no errors are reported), however, the binary file is not created, but the executable is created as normal. I have also tried doing this on much simpler code, which uses pthreads, with the same result.
Please examine the below and let me hear your thoughts.
gcc -pg --std=gnu99 -pthread -Wall -o pthreadsv0 pthreads.c
GCC compiling with -pg doesn't produce binary needed for Gprof.
The Gprof information is created when you execute the program after you compile with the -pg option. Try running your program. (You're profiling (Gprof) the execution of the program.)
The -pg compile option adds the necessary logic to create the profiling information when the program is executed. Executing the program, several times if desired or needed, allows the 'instrumented' code to write the data describing the logic flow and timing to the gmon.out file.