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).
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 |
These functions are GNU extensions.
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);
}
nproc(1)