profil — execution time profile
unsigned short int *buff,
unsigned int scale
controls profiling, by which the system maintains
estimates of the amount of time the calling program spends executing
at various places in its address space.
argument must point to an area of memory
whose length (in bytes) is given by
When profiling is on,
the process's program counter (pc) is examined each clock tick
times per second),
is subtracted from the pc value, and the result is multiplied by
If the resulting number corresponds to an element
inside the array of
unsigned short ints
points, that element is incremented.
The number of samples per second for a given implementation is given by
which is defined in
The scale is interpreted as an unsigned, sixteen bit,
fixed-point fraction with binary point at the left: 0177777 (octal)
gives a one-to-one mapping of pc's to words in
077777 (octal) maps each pair of instruction words together.
02(octal) maps all instructions onto the beginning of
(producing a non-interrupting core clock).
Profiling is turned off by giving a
of 0 or 1.
It is rendered ineffective by giving a
Profiling is turned off when one of the
functions is executed, but remains on in child and parent both after a
Profiling is turned off if an update in
would cause a memory fault.
No value is returned.
profil(): SVID2, SVID3, XPG2