PRF(7)              RISC/os Reference Manual               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).






























                        Printed 11/19/92                   Page 1