GET_NPROCS
Section: Linux Programmer's Manual (3)
Updated: 2017-09-15
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NAME
get_nprocs, get_nprocs_conf - get number of processors
SYNOPSIS
#include <sys/sysinfo.h>
int get_nprocs(void);
int get_nprocs_conf(void);
DESCRIPTION
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).
RETURN VALUE
As given in DESCRIPTION.
ATTRIBUTES
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
|
CONFORMING TO
These functions are GNU extensions.
NOTES
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 */
EXAMPLE
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);
}
COLOPHON
This page is part of release 4.13 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/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ATTRIBUTES
-
- CONFORMING TO
-
- NOTES
-
- EXAMPLE
-
- COLOPHON
-
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|
- Running on 
-
:
: 