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69724a11 WJ |
1 | /*- |
2 | * Copyright (c) 1989 The Regents of the University of California. | |
3 | * All rights reserved. | |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * 2. Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
13 | * 3. All advertising materials mentioning features or use of this software | |
14 | * must display the following acknowledgement: | |
15 | * This product includes software developed by the University of | |
16 | * California, Berkeley and its contributors. | |
17 | * 4. Neither the name of the University nor the names of its contributors | |
18 | * may be used to endorse or promote products derived from this software | |
19 | * without specific prior written permission. | |
20 | * | |
21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
31 | * SUCH DAMAGE. | |
32 | */ | |
33 | ||
34 | #if defined(LIBC_SCCS) && !defined(lint) | |
35 | static char sccsid[] = "@(#)getloadavg.c 6.2 (Berkeley) 6/29/90"; | |
36 | #endif /* LIBC_SCCS and not lint */ | |
37 | ||
38 | #include <sys/param.h> | |
39 | #include <sys/types.h> | |
40 | #include <sys/file.h> | |
41 | #include <nlist.h> | |
42 | ||
43 | static struct nlist nl[] = { | |
44 | { "_averunnable" }, | |
45 | #define X_AVERUNNABLE 0 | |
46 | { "_fscale" }, | |
47 | #define X_FSCALE 1 | |
48 | { "" }, | |
49 | }; | |
50 | ||
51 | /* | |
52 | * getloadavg() -- Get system load averages. | |
53 | * | |
54 | * Put `nelem' samples into `loadavg' array. | |
55 | * Return number of samples retrieved, or -1 on error. | |
56 | */ | |
57 | getloadavg(loadavg, nelem) | |
58 | double loadavg[]; | |
59 | int nelem; | |
60 | { | |
61 | static int need_nlist = 1; | |
62 | fixpt_t averunnable[3]; | |
63 | int fscale, kmemfd, i; | |
64 | int alreadyopen; | |
65 | ||
66 | if ((alreadyopen = kvm_openfiles(NULL, NULL, NULL)) == -1) | |
67 | return (-1); | |
68 | /* | |
69 | * cache nlist | |
70 | */ | |
71 | if (need_nlist) { | |
72 | if (kvm_nlist(nl) != 0) | |
73 | goto bad; | |
74 | need_nlist = 0; | |
75 | } | |
76 | if (kvm_read((off_t)nl[X_AVERUNNABLE].n_value, (char *)averunnable, | |
77 | sizeof(averunnable)) != sizeof(averunnable)) | |
78 | goto bad; | |
79 | if (kvm_read( (off_t)nl[X_FSCALE].n_value, (char *)&fscale, | |
80 | sizeof(fscale)) != sizeof(fscale)) | |
81 | goto bad; | |
82 | nelem = MIN(nelem, sizeof(averunnable) / sizeof(averunnable[0])); | |
83 | for (i = 0; i < nelem; i++) | |
84 | loadavg[i] = (double) averunnable[i] / fscale; | |
85 | if (!alreadyopen) | |
86 | kvm_close(); | |
87 | return (nelem); | |
88 | ||
89 | bad: | |
90 | if (!alreadyopen) | |
91 | kvm_close(); | |
92 | return (-1); | |
93 | } |