1 /* $OpenBSD: kvm_getloadavg.c,v 1.10 2021/09/10 00:02:43 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 #include <sys/signal.h> 34 #include <sys/time.h> 35 #include <sys/resource.h> 36 #include <sys/proc.h> 37 #include <sys/sysctl.h> 38 39 #include <db.h> 40 #include <fcntl.h> 41 #include <limits.h> 42 #include <nlist.h> 43 #include <stdlib.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 #define MINIMUM(a, b) (((a) < (b)) ? (a) : (b)) 57 58 /* 59 * kvm_getloadavg() -- Get system load averages, from live or dead kernels. 60 * 61 * Put `nelem' samples into `loadavg' array. 62 * Return number of samples retrieved, or -1 on error. 63 */ 64 int 65 kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem) 66 { 67 struct loadavg loadinfo; 68 struct nlist *p; 69 int fscale, i; 70 71 if (ISALIVE(kd)) 72 return (getloadavg(loadavg, nelem)); 73 74 if (kvm_nlist(kd, nl) != 0) { 75 for (p = nl; p->n_type != 0; ++p) 76 ; 77 _kvm_err(kd, kd->program, 78 "%s: no such symbol", p->n_name); 79 return (-1); 80 } 81 82 if (KREAD(kd, nl[X_AVERUNNABLE].n_value, &loadinfo)) { 83 _kvm_err(kd, kd->program, "can't read averunnable"); 84 return (-1); 85 } 86 87 /* 88 * Old kernels have fscale separately; if not found assume 89 * running new format. 90 */ 91 if (!KREAD(kd, nl[X_FSCALE].n_value, &fscale)) 92 loadinfo.fscale = fscale; 93 94 nelem = MINIMUM(nelem, sizeof(loadinfo.ldavg) / sizeof(fixpt_t)); 95 for (i = 0; i < nelem; i++) 96 loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale; 97 return (nelem); 98 } 99