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 |
get_nprocs(), get_nprocs_conf() |
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);
}