PROFIL(2)           UNIX Programmer's Manual            PROFIL(2)

NAME
     profil - execution time profile

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

DESCRIPTION
     _B_u_f_f points to an area of core whose length (in bytes) is
     given by _b_u_f_s_i_z.  After this call, the user's program
     counter (pc) is examined each clock tick (60th second);
     _o_f_f_s_e_t is subtracted from it, and the result multiplied by
     _s_c_a_l_e.  If the resulting number corresponds to a word inside
     _b_u_f_f, that word is incremented.

     The scale is interpreted as an unsigned, fixed-point frac-
     tion with binary point at the left: 0177777(8) gives a 1-1
     mapping of pc's to words in _b_u_f_f; 077777(8) maps each pair
     of instruction words together.  02(8) maps all instructions
     onto the beginning of _b_u_f_f (producing a non-interrupting
     core clock).

     Profiling is turned off by giving a _s_c_a_l_e of 0 or 1.  It is
     rendered ineffective by giving a _b_u_f_s_i_z of 0.  Profiling is
     turned off when an _e_x_e_c is executed, but remains on in child
     and parent both after a _f_o_r_k.  Profiling may be turned off
     if an update in _b_u_f_f would cause a memory fault.

SEE ALSO
     prof(1), monitor(3)

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

Printed 5/17/83                                                 1