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 1.4 2004/04/11 21:28:03 cpressey Exp $ 36 */ 37 38 #include <sys/param.h> 39 #include <sys/time.h> 40 #include <sys/resource.h> 41 #include <sys/sysctl.h> 42 #include <vm/vm_param.h> 43 44 #include <stdlib.h> 45 #include <fcntl.h> 46 #include <limits.h> 47 #include <nlist.h> 48 #include <kvm.h> 49 50 #include "kvm_private.h" 51 52 static struct nlist nl[] = { 53 { "_averunnable" }, 54 #define X_AVERUNNABLE 0 55 { "_fscale" }, 56 #define X_FSCALE 1 57 { "" }, 58 }; 59 60 /* 61 * kvm_getloadavg() -- Get system load averages, from live or dead kernels. 62 * 63 * Put `nelem' samples into `loadavg' array. 64 * Return number of samples retrieved, or -1 on error. 65 */ 66 int 67 kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem) 68 { 69 struct loadavg loadinfo; 70 struct nlist *p; 71 int fscale, i; 72 73 if (ISALIVE(kd)) 74 return (getloadavg(loadavg, nelem)); 75 76 if (kvm_nlist(kd, nl) != 0) { 77 for (p = nl; p->n_type != 0; ++p); 78 _kvm_err(kd, kd->program, 79 "%s: no such symbol", p->n_name); 80 return (-1); 81 } 82 83 #define KREAD(kd, addr, obj) \ 84 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 85 if (KREAD(kd, nl[X_AVERUNNABLE].n_value, &loadinfo)) { 86 _kvm_err(kd, kd->program, "can't read averunnable"); 87 return (-1); 88 } 89 90 /* 91 * Old kernels have fscale separately; if not found assume 92 * running new format. 93 */ 94 if (!KREAD(kd, nl[X_FSCALE].n_value, &fscale)) 95 loadinfo.fscale = fscale; 96 97 nelem = MIN(nelem, sizeof(loadinfo.ldavg) / sizeof(fixpt_t)); 98 for (i = 0; i < nelem; i++) 99 loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale; 100 return (nelem); 101 } 102