PRF(7)               INTERACTIVE UNIX System               PRF(7)



          NAME
               prf - operating system profiler

          DESCRIPTION
               The special file /dev/prf provides access to activity infor-
               mation 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).






























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