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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/.







  

    2020-12-21
    Linux