ultrix man page for profil

profil(2)							System Calls Manual							 profil(2)

Name
       profil - execution time profile

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

Description
       The  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 exam-
       ined each clock tick (on RISC machines, 4 milliseconds; on VAX machines, 10 milliseconds); offset is subtracted from the pc, and the result
       is 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: 0x10000 gives a 1-1 mapping of program
       counter's to words in buff; 0x8000 maps each pair of instruction words together.  0x2 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
       execve is executed, but remains on in both child and parent after a fork.  Profiling is turned off if an update in buff would cause a  mem-
       ory fault.

See Also
       gprof(1) (for VAX only), setitimer(2), monitor(3)

																	 profil(2)