Name

profil — execution time profile

Synopsis

        #include <unistd.h>
int profil( unsigned short *buf,
  size_t bufsiz,
  size_t offset,
  unsigned int scale);
 
[Note] Note
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. Libc 4.4 contained a kernel patch providing a system call profil.

SEE ALSO

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

COLOPHON

This page is part of release 4.07 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/.


  Copyright 1993 Rickard E. Faith (faithcs.unc.edu)

%%%LICENSE_START(VERBATIM)
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.

Since the Linux kernel and libraries are constantly changing, this
manual page may be incorrect or out-of-date.  The author(s) assume no
responsibility for errors or omissions, or for damages resulting from
the use of the information contained herein.  The author(s) may not
have taken the same level of care in the production of this manual,
which is licensed free of charge, as they might when working
professionally.

Formatted or processed versions of this manual, if unaccompanied by
the source, must acknowledge the copyright and authors of this work.
%%%LICENSE_END

Modified Fri Jun 23 01:35:19 1995 Andries Brouwer <aebcwi.nl>
(prompted by Bas V. de Bakker <basphys.uva.nl>)
Corrected (and moved to man3), 980612, aeb