profil(2)                                               profil(2)



NAME
     profil - reports the execution time of an application

SYNOPSIS
     profil(buff, bufsiz, offset, scale)
     char *buff;
     int bufsiz, offset, scale;

DESCRIPTION
     profil reports the performance analysis of an application.
     buff points to an area of core whose length (in bytes) is
     given by bufsiz.  After the call, the user's program counter
     (pc) is examined for each clock tick; offset is subtracted
     from it, and the result multiplied by scale.  If the
     resulting number corresponds to a word inside buff, that
     word is incremented.

     The scale is interpreted as an unsigned, fixed-point
     fraction with 16 bits of fraction:  0x10000 gives a 1-1
     mapping of pc's to words in buff; 0x8000 maps each pair of
     instruction words together; 2 maps all instructions onto the
     beginning of buff (producing a noninterrupting core clock).

     Profiling is turned off by giving a scale of 0 or 1.  It is
     rendered ineffective by giving a bufsiz of 0.  Profiling is
     turned off when an exec is executed, but remains on in child
     and parent both after a fork.  Profiling will be turned off
     if an update in buff would cause a memory fault.

STATUS MESSAGES AND VALUES
     Not defined.

SEE ALSO
     monitor(3C)

     prof(1) in A/UX Command Reference



















January 1992                                                    1