1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
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
33 #include <sys/param.h>
34 #include <sys/time.h>
35 #include <sys/resource.h>
36
37 #include <stdlib.h>
38 #include <limits.h>
39 #include <nlist.h>
40 #include <kvm.h>
41
42 #include "kvm_private.h"
43
44 static struct nlist nl[] = {
45 { .n_name = "_averunnable" },
46 #define X_AVERUNNABLE 0
47 { .n_name = "_fscale" },
48 #define X_FSCALE 1
49 { .n_name = "" },
50 };
51
52 /*
53 * kvm_getloadavg() -- Get system load averages, from live or dead kernels.
54 *
55 * Put `nelem' samples into `loadavg' array.
56 * Return number of samples retrieved, or -1 on error.
57 */
58 int
kvm_getloadavg(kvm_t * kd,double loadavg[],int nelem)59 kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem)
60 {
61 struct loadavg loadinfo;
62 int fscale, i;
63
64 if (ISALIVE(kd))
65 return (getloadavg(loadavg, nelem));
66
67 if (!kd->arch->ka_native(kd)) {
68 _kvm_err(kd, kd->program,
69 "cannot read loadavg from non-native core");
70 return (-1);
71 }
72
73 if (kvm_nlist(kd, nl) != 0 && nl[X_AVERUNNABLE].n_type == 0) {
74 _kvm_err(kd, kd->program,
75 "%s: no such symbol", nl[X_AVERUNNABLE].n_name);
76 return (-1);
77 }
78
79 #define KREAD(kd, addr, obj) \
80 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj))
81 if (KREAD(kd, nl[X_AVERUNNABLE].n_value, &loadinfo)) {
82 _kvm_err(kd, kd->program, "can't read averunnable");
83 return (-1);
84 }
85
86 /*
87 * Old kernels have fscale separately; if not found assume
88 * running new format.
89 */
90 if (nl[X_FSCALE].n_type != 0 &&
91 !KREAD(kd, nl[X_FSCALE].n_value, &fscale))
92 loadinfo.fscale = fscale;
93
94 nelem = MIN(nelem, (int)(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