prf(7)                 DEVICES AND MODULES                 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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