|
HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|
|
NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ATTRIBUTES | STANDARDS | NOTES | EXAMPLES | SEE ALSO | COLOPHON |
|
|
|
get_nprocs(3) Library Functions Manual get_nprocs(3)
get_nprocs, get_nprocs_conf - get number of processors
Standard C library (libc, -lc)
#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).
As given in DESCRIPTION.
For an explanation of the terms used in this section, see
attributes(7).
┌─────────────────────────────────────┬───────────────┬─────────┐
│ Interface │ Attribute │ Value │
├─────────────────────────────────────┼───────────────┼─────────┤
│ get_nprocs(), get_nprocs_conf() │ Thread safety │ MT-Safe │
└─────────────────────────────────────┴───────────────┴─────────┘
GNU.
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 <stdio.h>
#include <stdlib.h>
#include <sys/sysinfo.h>
int
main(void)
{
printf("This system has %d processors configured and "
"%d processors available.\n",
get_nprocs_conf(), get_nprocs());
exit(EXIT_SUCCESS);
}
nproc(1)
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.9.1.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2024-06-26. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
[email protected]
Linux man-pages 6.9.1 2024-06-15 get_nprocs(3)
Pages that refer to this page: sched_setaffinity(2), sysconf(3)
|
HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|