Yes, including "prof.h" is enough, but you can try using different events, by default Prof uses `PERF_COUNT_HW_REF_CPU_CYCLES`. For example try defining before #include "prof.h":

#define PROF_EVENT_LIST PROF_EVENT_HW(CPU_CYCLES)

or

#define PROF_EVENT_LIST PROF_EVENT_SW(CPU_CLOCK)

Which kernel version are you running? Are you running this from a virtual machine?

Feel free to open an issue (https://github.com/cyrus-and/prof/issues) with these information if you can't manage to make it work.