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

NAME
       profil - execution time profile

SYNOPSIS
       #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():
           Since glibc 2.21:
               _DEFAULT_SOURCE
           In glibc 2.19 and 2.20:
               _DEFAULT_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500)
           Up to and including glibc 2.19:
               _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 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
       Zero is always returned.

ATTRIBUTES
       For an explanation of the terms used in this section, see attributes(7).

       ┌────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┬───────────────┬───────────┐
       │Interface                                                                                                                           │ Attribute     │ Value     │
       ├────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────┼───────────┤
       │profil()                                                                                                                            │ Thread safety │ MT-Unsafe │
       └────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┴───────────────┴───────────┘

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

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

       True kernel profiling provides more accurate results.

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

Linux                                                                          2021-03-22                                                                      PROFIL(3)