table of contents
get_nprocs(3) | Library Functions Manual | get_nprocs(3) |
NAME¶
get_nprocs, get_nprocs_conf - get number of processors
LIBRARY¶
Standard C library (libc, -lc)
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 |
STANDARDS¶
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 */
EXAMPLES¶
The following example shows how get_nprocs() and get_nprocs_conf() can be used.
#include <stdio.h> #include <stdlib.h> #include <sys/sysinfo.h> int main(void) {
printf("This system has %d processors configured and "
"%d processors available.\n",
get_nprocs_conf(), get_nprocs());
exit(EXIT_SUCCESS); }
SEE ALSO¶
2022-12-15 | Linux man-pages 6.03 |