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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | CONFORMING TO | BUGS | SEE ALSO | COLOPHON


PROFIL(3)                     Linux Programmer's Manual                     PROFIL(3)

NAME         top

       profil - execution time profile

SYNOPSIS         top

       #include <unistd.h>

       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         top

       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 user's 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, profiling is disabled.

RETURN VALUE         top

       Zero is always returned.

CONFORMING TO         top

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

BUGS         top

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

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

SEE ALSO         top

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

COLOPHON         top

       This page is part of release 3.23 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)