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, size_t offset, unsigned
12       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 3.25 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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