PROFIL(2) PROFIL(2)
NAME
profil - execution time profile
SYNOPSIS
void profil(buff, bufsiz, offset, scale)
unsigned short *buff;
int bufsiz, offset;
unsigned 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
is examined each clock tick; offset is subtracted from it,
and the result multiplied by scale, divided by 65536 and
then rounded up to a multiple of two. If the resulting num-
ber (n) is less than bufsiz, then buff[n/2] is incremented.
Profiling is turned off by giving a scale of 0. It is ren-
dered 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 is turned off if an
update in buff would cause a memory fault.
SEE ALSO
prof(1), monitor(3)
BUGS
Because of the rounding up, single byte instructions cannot
be exactly profiled.