profil(2) [bsd man page]

PROFIL(2)							System Calls Manual							 PROFIL(2)

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 (VAX and TAHOE: 100 ticks/second = 10 milliseconds per tick; 60 ticks/second ~= 16 milliseconds per tick); offset  is  sub-
       tracted 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: 0xffff gives a 1-1 mapping of pc's to words in
       buff; 0x7fff 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 mem-
       ory fault.

RETURN VALUE

       A 0, indicating success, is always returned.

SEE ALSO

       gprof(1), prof(1), setitimer(2), monitor(3)

3rd Berkeley Distribution					    May 6, 1987 							 PROFIL(2)

profil(2)							System Calls Manual							 profil(2)

NAME

       profil - execution time profile

SYNOPSIS

DESCRIPTION

       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.

       The buff argument must point to an area of memory whose length (in bytes) is given by bufsiz.  When profiling is on, the process's  program
       counter	(pc) is examined each clock tick times per second), offset is subtracted from the pc value, and the result is multiplied by scale.
       If the resulting number corresponds to an element inside the array of to which buff 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 buff; 077777 (octal) maps each pair of instruction words together.  02(octal) 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 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 buff would cause a
       memory fault.

RETURN VALUE

       No value is returned.

SEE ALSO

       prof(1), monitor(3C).

STANDARDS CONFORMANCE

																	 profil(2)