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 (10 milliseconds); 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.

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 child and parent
both after a fork. Profiling is turned off if an update in buff
would cause a memory fault.

RETURN VALUE
A 0, indicating success, is always returned.

SEE ALSO
gprof(1), setitimer(2), monitor(3)