profil - execution time profile
#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)
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.
Zero is always returned.
For an explanation of the terms used in this section, see
attributes(7).
| Interface |
Attribute |
Value |
| profil () |
Thread safety |
MT-Unsafe |
Similar to a call in SVr4 (but not POSIX.1).
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.
gprof(1),
sprof(1),
setitimer(2),
sigaction(2),
signal(2)