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 operat‐
       ing system.

       The function get_nprocs() returns the number of processors currently available in the sys‐
       tem.   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.\n",
                   get_nprocs_conf(), get_nprocs());
           return 0;
       }


COLOPHON
       This page is part of release 3.74 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 http://www.kernel.org/doc/man-pages/.



GNU                                         2012-03-20                              GET_NPROCS(3)