v7 man page for profil

PROFIL(2)							System Calls Manual							 PROFIL(2)

NAME
       profil - execution time profile

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

DESCRIPTION
       Buff  points  to  an area of core whose length (in bytes) is given by bufsiz.  After this call, the user's program counter (pc) is examined
       each clock tick (60th second); 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 binary point at the left: 0177777(8) gives a 1-1 mapping of pc's to
       words in buff; 077777(8) maps each pair of instruction words together.  02(8) maps all instructions onto the beginning of buff (producing a
       non-interrupting 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 may be turned off if an update in  buff  would  cause  a
       memory fault.

SEE ALSO
       monitor(3), prof(1)

ASSEMBLER
       (profil = 44.)
       sys profil; buff; bufsiz; offset; scale

																	 PROFIL(2)