PRF(7)                                                     PRF(7)



     NAME
          prf - operating system profiler

     DESCRIPTION
          The special file /dev/prf provides access to activity
          information in the operating system.  Writing the file loads
          the measurement facility with text addresses to be
          monitored.  Reading the file returns these addresses and a
          set of counters indicative of activity between adjacent text
          addresses.

          The recording mechanism is driven by the system clock and
          samples the program counter at line frequency.  Samples that
          catch the operating system are matched against the stored
          text addresses and increment corresponding counters for
          later processing.

          The file /dev/prf is a pseudo-device with no associated
          hardware.

     FILES
          /dev/prf

     SEE ALSO
          profiler(1M).

     ORIGIN
          AT&T V.3



























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