1PROFIL(3)                  Linux Programmer's Manual                 PROFIL(3)
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NAME

6       profil - execution time profile
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SYNOPSIS

9       #include <unistd.h>
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11       int profil(unsigned short *buf, size_t bufsiz,
12                  size_t offset, unsigned int scale);
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14   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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16       profil(): _BSD_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500)
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DESCRIPTION

19       This  routine  provides  a means to find out in what areas your program
20       spends most of its time.  The argument buf points to  bufsiz  bytes  of
21       core.   Every  virtual 10 milliseconds, the user's program counter (PC)
22       is examined: offset is subtracted and the result is multiplied by scale
23       and divided by 65536.  If the resulting value is less than bufsiz, then
24       the corresponding entry in buf is incremented.  If buf is NULL, profil‐
25       ing is disabled.
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RETURN VALUE

28       Zero is always returned.
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CONFORMING TO

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

34       profil()  cannot be used on a program that also uses ITIMER_PROF inter‐
35       val timers (see setitimer(2)).
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37       True kernel profiling provides more accurate results.   Libc  4.4  con‐
38       tained a kernel patch providing a system call profil.
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SEE ALSO

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

44       This  page  is  part of release 3.53 of the Linux man-pages project.  A
45       description of the project, and information about reporting  bugs,  can
46       be found at http://www.kernel.org/doc/man-pages/.
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50Linux                             2007-07-26                         PROFIL(3)
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