1 /* $NetBSD: getloadavg.c,v 1.14 2012/03/13 21:13:36 christos 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. 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[] = "@(#)getloadavg.c 8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: getloadavg.c,v 1.14 2012/03/13 21:13:36 christos Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40
41 #include "namespace.h"
42 #include <sys/param.h>
43 #include <sys/time.h>
44 #include <sys/resource.h>
45 #include <sys/sysctl.h>
46 #include <uvm/uvm_param.h>
47
48 #include <assert.h>
49 #include <errno.h>
50 #include <stdlib.h>
51
52 #ifdef __weak_alias
__weak_alias(getloadavg,_getloadavg)53 __weak_alias(getloadavg,_getloadavg)
54 #endif
55
56 /*
57 * getloadavg() -- Get system load averages.
58 *
59 * Put `nelem' samples into `loadavg' array.
60 * Return number of samples retrieved, or -1 on error.
61 */
62 int
63 getloadavg(double loadavg[], int nelem)
64 {
65 struct loadavg loadinfo;
66 static const int mib[] = { CTL_VM, VM_LOADAVG };
67 size_t size, i;
68
69 _DIAGASSERT(loadavg != NULL);
70 _DIAGASSERT(nelem >= 0);
71
72 size = sizeof(loadinfo);
73 if (sysctl(mib, (u_int)__arraycount(mib), &loadinfo, &size, NULL, 0)
74 == -1)
75 return -1;
76
77 size = MIN((size_t)nelem, __arraycount(loadinfo.ldavg));
78 for (i = 0; i < size; i++)
79 loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale;
80 return nelem;
81 }
82