prf(7)                                                        prf(7)


       NAME
             prf - operating system profiler

       DESCRIPTION
             The special file /dev/prf provides access to activity
             information in the operating system.  The profiler commands
             load 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

       NOTICES
             If the prf device is not configured into the kernel, 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.

             When the profiler is turned on, loadable modules are locked
             into memory and cannot be unloaded.  Subsequently loaded
             modules will also be locked until profiling is disabled.

       REFERENCES
             profiler(1M)














                           Copyright 1994 Novell, Inc.               Page 1