1/*	$NetBSD: kvm_getloadavg.c,v 1.10.8.1 2012/04/23 16:48:53 riz Exp $	*/
2
3/*-
4 * Copyright (c) 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. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#if defined(LIBC_SCCS) && !defined(lint)
34#if 0
35static char sccsid[] = "@(#)kvm_getloadavg.c	8.1 (Berkeley) 6/4/93";
36#else
37__RCSID("$NetBSD: kvm_getloadavg.c,v 1.10.8.1 2012/04/23 16:48:53 riz Exp $");
38#endif
39#endif /* LIBC_SCCS and not lint */
40
41#include <sys/param.h>
42#include <sys/time.h>
43#include <sys/resource.h>
44#include <sys/lwp.h>
45#include <sys/proc.h>
46#include <sys/sysctl.h>
47#include <uvm/uvm_param.h>
48
49#include <db.h>
50#include <fcntl.h>
51#include <limits.h>
52#include <nlist.h>
53#include <kvm.h>
54#include <stdlib.h>
55
56#include "kvm_private.h"
57
58static struct nlist nl[] = {
59	{ "_averunnable" },
60#define	X_AVERUNNABLE	0
61	{ "_fscale" },
62#define	X_FSCALE	1
63	{ "" },
64};
65
66/*
67 * kvm_getloadavg() -- Get system load averages, from live or dead kernels.
68 *
69 * Put `nelem' samples into `loadavg' array.
70 * Return number of samples retrieved, or -1 on error.
71 */
72int
73kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem)
74{
75	struct loadavg loadinfo;
76	struct nlist *p;
77	int fscale, i;
78
79	if (ISALIVE(kd))
80		return (getloadavg(loadavg, nelem));
81
82	if (kvm_nlist(kd, nl) != 0) {
83		for (p = nl; p->n_type != 0; ++p);
84		_kvm_err(kd, kd->program,
85		    "%s: no such symbol", p->n_name);
86		return (-1);
87	}
88
89	if (KREAD(kd, nl[X_AVERUNNABLE].n_value, &loadinfo)) {
90		_kvm_err(kd, kd->program, "can't read averunnable");
91		return (-1);
92	}
93
94	/*
95	 * Old kernels have fscale separately; if not found assume
96	 * running new format.
97	 */
98	if (!KREAD(kd, nl[X_FSCALE].n_value, &fscale))
99		loadinfo.fscale = fscale;
100
101	nelem = MIN(nelem, sizeof(loadinfo.ldavg) / sizeof(fixpt_t));
102	for (i = 0; i < nelem; i++)
103		loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale;
104	return (nelem);
105}
106