1 /* $NetBSD: kvm_getloadavg.c,v 1.11 2012/03/21 10:10:36 matt 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
35 static char sccsid[] = "@(#)kvm_getloadavg.c 8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: kvm_getloadavg.c,v 1.11 2012/03/21 10:10:36 matt 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
58 static struct nlist nl[] = {
59 { .n_name = "_averunnable" },
60 #define X_AVERUNNABLE 0
61 { .n_name = "_fscale" },
62 #define X_FSCALE 1
63 { .n_name = "" },
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 */
72 int
kvm_getloadavg(kvm_t * kd,double loadavg[],int nelem)73 kvm_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