GET_NPROCS(3) Linux Programmer's Manual GET_NPROCS(3)
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.
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 <stdio.h>
#include <sys/sysinfo.h>
int
main(int argc, char *argv[])
{
printf("This system has %d processors configured and "
"%d processors available.
",
get_nprocs_conf(), get_nprocs());
return 0;
}
GNU
2012-03-20 GET_NPROCS(3)