projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 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 | } |