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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)kvm_getloadavg.c 8.1 (Berkeley) 6/4/93 30 * $FreeBSD: src/lib/libkvm/kvm_getloadavg.c,v 1.3 1999/12/27 07:14:57 peter Exp $ 31 * $DragonFly: src/lib/libkvm/kvm_getloadavg.c,v 1.4 2004/04/11 21:28:03 cpressey Exp $ 32 */ 33 34 #include <sys/param.h> 35 #include <sys/time.h> 36 #include <sys/resource.h> 37 #include <sys/sysctl.h> 38 #include <vm/vm_param.h> 39 40 #include <stdlib.h> 41 #include <fcntl.h> 42 #include <limits.h> 43 #include <nlist.h> 44 #include <kvm.h> 45 46 #include "kvm_private.h" 47 48 static struct nlist nl[] = { 49 { "_averunnable" }, 50 #define X_AVERUNNABLE 0 51 { "_fscale" }, 52 #define X_FSCALE 1 53 { "" }, 54 }; 55 56 /* 57 * kvm_getloadavg() -- Get system load averages, from live or dead kernels. 58 * 59 * Put `nelem' samples into `loadavg' array. 60 * Return number of samples retrieved, or -1 on error. 61 */ 62 int 63 kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem) 64 { 65 struct loadavg loadinfo; 66 struct nlist *p; 67 int fscale, i; 68 69 if (kvm_ishost(kd)) 70 return (getloadavg(loadavg, nelem)); 71 72 if (kvm_nlist(kd, nl) != 0) { 73 for (p = nl; p->n_type != 0; ++p); 74 _kvm_err(kd, kd->program, 75 "%s: no such symbol", p->n_name); 76 return (-1); 77 } 78 79 #define KREAD(kd, addr, obj) \ 80 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 81 if (KREAD(kd, nl[X_AVERUNNABLE].n_value, &loadinfo)) { 82 _kvm_err(kd, kd->program, "can't read averunnable"); 83 return (-1); 84 } 85 86 /* 87 * Old kernels have fscale separately; if not found assume 88 * running new format. 89 */ 90 if (!KREAD(kd, nl[X_FSCALE].n_value, &fscale)) 91 loadinfo.fscale = fscale; 92 93 nelem = MIN(nelem, sizeof(loadinfo.ldavg) / sizeof(fixpt_t)); 94 for (i = 0; i < nelem; i++) 95 loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale; 96 return (nelem); 97 } 98