prf(7)       UNIX System V(System Performance Analysis Utilities)        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

NOTES
      By default, the prf device is not configured into the kernel for Intel
      processors.  To turn it on, you must edit the /etc/conf/sdevice.d/prf
      file, change the second field from N to Y, and reconfigure the kernel.

SEE ALSO
      profiler(1M)



























10/89                                                                    Page 1