1 /* $OpenBSD: kvm_getloadavg.c,v 1.7 2006/03/31 03:59:40 deraadt Exp $ */ 2 /* $NetBSD: kvm_getloadavg.c,v 1.2 1996/03/18 22:33:31 thorpej Exp $ */ 3 4 /*- 5 * Copyright (c) 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)kvm_getloadavg.c 8.1 (Berkeley) 6/4/93"; 36 #else 37 static char *rcsid = "$OpenBSD: kvm_getloadavg.c,v 1.7 2006/03/31 03:59:40 deraadt Exp $"; 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <sys/param.h> 42 #include <sys/time.h> 43 #include <sys/resource.h> 44 #include <sys/proc.h> 45 #include <sys/sysctl.h> 46 47 #include <db.h> 48 #include <fcntl.h> 49 #include <limits.h> 50 #include <nlist.h> 51 #include <stdlib.h> 52 #include <kvm.h> 53 54 #include "kvm_private.h" 55 56 static struct nlist nl[] = { 57 { "_averunnable" }, 58 #define X_AVERUNNABLE 0 59 { "_fscale" }, 60 #define X_FSCALE 1 61 { "" }, 62 }; 63 64 /* 65 * kvm_getloadavg() -- Get system load averages, from live or dead kernels. 66 * 67 * Put `nelem' samples into `loadavg' array. 68 * Return number of samples retrieved, or -1 on error. 69 */ 70 int 71 kvm_getloadavg(kvm_t *kd, double loadavg[], 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 ; 83 _kvm_err(kd, kd->program, 84 "%s: no such symbol", p->n_name); 85 return (-1); 86 } 87 88 #define KREAD(kd, addr, obj) \ 89 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 90 91 if (KREAD(kd, nl[X_AVERUNNABLE].n_value, &loadinfo)) { 92 _kvm_err(kd, kd->program, "can't read averunnable"); 93 return (-1); 94 } 95 96 /* 97 * Old kernels have fscale separately; if not found assume 98 * running new format. 99 */ 100 if (!KREAD(kd, nl[X_FSCALE].n_value, &fscale)) 101 loadinfo.fscale = fscale; 102 103 nelem = MIN(nelem, sizeof(loadinfo.ldavg) / sizeof(fixpt_t)); 104 for (i = 0; i < nelem; i++) 105 loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale; 106 return (nelem); 107 } 108