get_nprocs, get_nprocs_conf — get number of processors
#include <sys/sysinfo.h>
int
get_nprocs( |
void); |
int
get_nprocs_conf( |
void); |
The function get_nprocs_conf() returns the number of
processors configured by the operating system.
The function get_nprocs()
returns the number of processors currently available in the
system. This may be less than the number returned by
get_nprocs_conf() because
processors may be offline (e.g., on hotpluggable
systems).
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
|
|
Thread safety | MT-Safe |
The current implementation of these functions is rather
expensive, since they open and parse files in the
/sys filesystem each time they
are called.
The following sysconf(3) calls make use of the functions documented on this page to return the same information.
np = sysconf(_SC_NPROCESSORS_CONF); /* processors configured */
np = sysconf(_SC_NPROCESSORS_ONLN); /* processors available */
The following example shows how get_nprocs() and get_nprocs_conf() can be used.
#include <stdlib.h>
#include <stdio.h>
#include <sys/sysinfo.h>
int
main(int argc, char *argv[])
{
printf("This system has %d processors configured and "
"%d processors available.\n",
get_nprocs_conf(), get_nprocs());
exit(EXIT_SUCCESS);
}
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 (c) 2012, Petr Benas and Copyright (c) 2012, Michael Kerrisk <mtk.man-pagesgmail.com> %%%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 Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date.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 |