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getloadavg.c revision 1.11 
      1 /*	$NetBSD: getloadavg.c,v 1.11 2000/06/26 15:37:28 mrg Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1989, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #if defined(LIBC_SCCS) && !defined(lint)
     38 #if 0
     39 static char sccsid[] = "@(#)getloadavg.c	8.1 (Berkeley) 6/4/93";
     40 #else
     41 __RCSID("$NetBSD: getloadavg.c,v 1.11 2000/06/26 15:37:28 mrg Exp $");
     42 #endif
     43 #endif /* LIBC_SCCS and not lint */
     44 
     45 #include "namespace.h"
     46 #include <sys/param.h>
     47 #include <sys/time.h>
     48 #include <sys/resource.h>
     49 #include <sys/sysctl.h>
     50 #include <uvm/uvm_param.h>
     51 
     52 #include <assert.h>
     53 #include <errno.h>
     54 #include <stdlib.h>
     55 
     56 #ifdef __weak_alias
     57 __weak_alias(getloadavg,_getloadavg)
     58 #endif
     59 
     60 /*
     61  * getloadavg() -- Get system load averages.
     62  *
     63  * Put `nelem' samples into `loadavg' array.
     64  * Return number of samples retrieved, or -1 on error.
     65  */
     66 int
     67 getloadavg(loadavg, nelem)
     68 	double loadavg[];
     69 	int nelem;
     70 {
     71 	struct loadavg loadinfo;
     72 	int i, mib[2];
     73 	size_t size;
     74 
     75 	_DIAGASSERT(loadavg != NULL);
     76 
     77 	mib[0] = CTL_VM;
     78 	mib[1] = VM_LOADAVG;
     79 	size = sizeof(loadinfo);
     80 	if (sysctl(mib, 2, &loadinfo, &size, NULL, 0) < 0)
     81 		return (-1);
     82 
     83 	nelem = MIN(nelem, sizeof(loadinfo.ldavg) / sizeof(fixpt_t));
     84 	for (i = 0; i < nelem; i++)
     85 		loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale;
     86 	return (nelem);
     87 }
     88