1 /* $OpenBSD: kvm_getloadavg.c,v 1.10 2021/09/10 00:02:43 deraadt Exp $ */
2 /* $NetBSD: kvm_getloadavg.c,v 1.2 1996/03/18 22:33:31 thorpej Exp $ */
3
4 /*-
5 * Copyright (c) 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <sys/signal.h>
34 #include <sys/time.h>
35 #include <sys/resource.h>
36 #include <sys/proc.h>
37 #include <sys/sysctl.h>
38
39 #include <db.h>
40 #include <fcntl.h>
41 #include <limits.h>
42 #include <nlist.h>
43 #include <stdlib.h>
44 #include <kvm.h>
45
46 #include "kvm_private.h"
47
48 static struct nlist nl[] = {
49 { "_averunnable" },
50 #define X_AVERUNNABLE 0
51 { "_fscale" },
52 #define X_FSCALE 1
53 { "" },
54 };
55
56 #define MINIMUM(a, b) (((a) < (b)) ? (a) : (b))
57
58 /*
59 * kvm_getloadavg() -- Get system load averages, from live or dead kernels.
60 *
61 * Put `nelem' samples into `loadavg' array.
62 * Return number of samples retrieved, or -1 on error.
63 */
64 int
kvm_getloadavg(kvm_t * kd,double loadavg[],int nelem)65 kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem)
66 {
67 struct loadavg loadinfo;
68 struct nlist *p;
69 int fscale, i;
70
71 if (ISALIVE(kd))
72 return (getloadavg(loadavg, nelem));
73
74 if (kvm_nlist(kd, nl) != 0) {
75 for (p = nl; p->n_type != 0; ++p)
76 ;
77 _kvm_err(kd, kd->program,
78 "%s: no such symbol", p->n_name);
79 return (-1);
80 }
81
82 if (KREAD(kd, nl[X_AVERUNNABLE].n_value, &loadinfo)) {
83 _kvm_err(kd, kd->program, "can't read averunnable");
84 return (-1);
85 }
86
87 /*
88 * Old kernels have fscale separately; if not found assume
89 * running new format.
90 */
91 if (!KREAD(kd, nl[X_FSCALE].n_value, &fscale))
92 loadinfo.fscale = fscale;
93
94 nelem = MINIMUM(nelem, sizeof(loadinfo.ldavg) / sizeof(fixpt_t));
95 for (i = 0; i < nelem; i++)
96 loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale;
97 return (nelem);
98 }
99