1 /*- 2 * Copyright (c) 1993 3 * The Regents of the University of California. 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 * @(#)kvm_getloadavg.c 8.1 (Berkeley) 6/4/93 34 * $FreeBSD: src/lib/libkvm/kvm_getloadavg.c,v 1.3 1999/12/27 07:14:57 peter Exp $ 35 * $DragonFly: src/lib/libkvm/kvm_getloadavg.c,v 1.2 2003/06/17 04:26:49 dillon Exp $ 36 */ 37 38 #include <sys/param.h> 39 #include <sys/time.h> 40 #include <sys/resource.h> 41 #include <sys/proc.h> 42 #include <sys/sysctl.h> 43 #include <vm/vm_param.h> 44 45 #include <stdlib.h> 46 #include <fcntl.h> 47 #include <limits.h> 48 #include <nlist.h> 49 #include <kvm.h> 50 51 #include "kvm_private.h" 52 53 static struct nlist nl[] = { 54 { "_averunnable" }, 55 #define X_AVERUNNABLE 0 56 { "_fscale" }, 57 #define X_FSCALE 1 58 { "" }, 59 }; 60 61 /* 62 * kvm_getloadavg() -- Get system load averages, from live or dead kernels. 63 * 64 * Put `nelem' samples into `loadavg' array. 65 * Return number of samples retrieved, or -1 on error. 66 */ 67 int 68 kvm_getloadavg(kd, loadavg, nelem) 69 kvm_t *kd; 70 double loadavg[]; 71 int nelem; 72 { 73 struct loadavg loadinfo; 74 struct nlist *p; 75 int fscale, i; 76 77 if (ISALIVE(kd)) 78 return (getloadavg(loadavg, nelem)); 79 80 if (kvm_nlist(kd, nl) != 0) { 81 for (p = nl; p->n_type != 0; ++p); 82 _kvm_err(kd, kd->program, 83 "%s: no such symbol", p->n_name); 84 return (-1); 85 } 86 87 #define KREAD(kd, addr, obj) \ 88 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 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