profil

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)

COLOPHON
       This page is part of release 5.10 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.



Linux                              2020-12-21                          PROFIL(3)