profil (3)
Leading comments
Copyright 1993 Rickard E. Faith (faith@cs.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 th...
NAME
profil - execution time profileSYNOPSIS
#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(): _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.