PROFIL(II) 5/15/74 PROFIL(II)
NAME
profil - execution time profile
SYNOPSIS
(profil = 44.; not in assembler)
sys profil; buff; bufsiz; offset; scale
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: 177777(8) gives a
1-1 mapping of pc's to words in buff; 77777(8) maps each
pair of instruction words together. 2(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
also turned off when an exec is executed but remains on in
child and parent both after a fork.
SEE ALSO
monitor (III), prof (I)
DIAGNOSTICS