GET_NPROCS

Section: Linux Programmer's Manual (3)
Updated: 2017-09-15
Index Return to Main Contents
 

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).
InterfaceAttributeValue
get_nprocs(),
get_nprocs_conf()
Thread safetyMT-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); }  

SEE ALSO

nproc(1)  

COLOPHON

This page is part of release 4.15 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
SEE ALSO
COLOPHON

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Time: 06:25:28 GMT, September 23, 2018