get_nprocs(3) [linux man page]

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)

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.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       +------------------+---------------+---------+
       |Interface	  | Attribute	  | Value   |
       +------------------+---------------+---------+
       |get_nprocs(),	  | Thread safety | MT-Safe |
       |get_nprocs_conf() |		  |	    |
       +------------------+---------------+---------+

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.
",
		   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/.

GNU
								    2017-09-15							     GET_NPROCS(3)