To generate a time and allocation profile, give one of the
    following RTS options to the compiled program when you run it (RTS
    options should be enclosed between +RTS...-RTS
    as usual):
-p or -P or -pa:
          
          
          
          
        The -p option produces a standard
          time profile report.  It is written
          into the file
          .program.prof
The -P option produces a more
          detailed report containing the actual time and allocation
          data as well.  (Not used much.)
The -pa option produces the most detailed
          report containing all cost centres in addition to the actual time
          and allocation data.
-Vsecs
       Sets the interval that the RTS clock ticks at, which is also the sampling interval of the time and allocation profile. The default is 0.02 second.
-xc
          
        This option makes use of the extra information maintained by the cost-centre-stack profiler to provide useful information about the location of runtime errors. See Section 4.16.7, “RTS options for hackers, debuggers, and over-interested souls”.