PROFIL(3)		   Linux Programmers Manual		    PROFIL(3)



NAME
       profil - execution time profile

SYNOPSIS
       #include 

       int  profil(unsigned short *buf, size_t bufsiz, size_t offset, unsigned
       int scale);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       profil(): _BSD_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500)

DESCRIPTION
       This routine provides a means to find out in what  areas  your  program
       spends  most  of  its time.  The argument buf points to bufsiz bytes of
       core.  Every virtual 10 milliseconds, the users program	counter  (PC)
       is examined: offset is subtracted and the result is multiplied by scale
       and divided by 65536.  If the resulting value is less than bufsiz, then
       the corresponding entry in buf is incremented.  If buf is NULL, profil
       ing is disabled.

RETURN VALUE
       Zero is always returned.

CONFORMING TO
       Similar to a call in SVr4 (but not POSIX.1-2001).

BUGS
       profil() cannot be used on a program that also uses ITIMER_PROF	inter
       val timers (see setitimer(2)).

       True  kernel  profiling	provides more accurate results.  Libc 4.4 con
       tained a kernel patch providing a system call profil.

SEE ALSO
       gprof(1), setitimer(2), sigaction(2), signal(2)

COLOPHON
       This page is part of release 3.05 of the Linux  man-pages  project.   A
       description  of	the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.



Linux				  2007-07-26			     PROFIL(3)