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 */ 32 33 #include <sys/param.h> 34 #include <sys/time.h> 35 #include <sys/resource.h> 36 #include <sys/sysctl.h> 37 #include <vm/vm_param.h> 38 39 #include <stdlib.h> 40 #include <fcntl.h> 41 #include <limits.h> 42 #include <nlist.h> 43 44 #include "kvm.h" 45 #include "kvm_private.h" 46 47 static struct nlist nl[] = { 48 { .n_name = "_averunnable" }, 49 #define X_AVERUNNABLE 0 50 { .n_name = "_fscale" }, 51 #define X_FSCALE 1 52 { .n_name = "" }, 53 }; 54 55 /* 56 * kvm_getloadavg() -- Get system load averages, from live or dead kernels. 57 * 58 * Put `nelem' samples into `loadavg' array. 59 * Return number of samples retrieved, or -1 on error. 60 */ 61 int 62 kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem) 63 { 64 struct loadavg loadinfo; 65 struct nlist *p; 66 int fscale, i; 67 68 if (kvm_ishost(kd)) 69 return (getloadavg(loadavg, nelem)); 70 71 if (kvm_nlist(kd, nl) != 0) { 72 for (p = nl; p->n_type != 0; ++p); 73 _kvm_err(kd, kd->program, 74 "%s: no such symbol", p->n_name); 75 return (-1); 76 } 77 78 #define KREAD(kd, addr, obj) \ 79 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 80 if (KREAD(kd, nl[X_AVERUNNABLE].n_value, &loadinfo)) { 81 _kvm_err(kd, kd->program, "can't read averunnable"); 82 return (-1); 83 } 84 85 /* 86 * Old kernels have fscale separately; if not found assume 87 * running new format. 88 */ 89 if (!KREAD(kd, nl[X_FSCALE].n_value, &fscale)) 90 loadinfo.fscale = fscale; 91 92 nelem = MIN((size_t)nelem, sizeof(loadinfo.ldavg) / sizeof(__uint64_t)); 93 for (i = 0; i < nelem; i++) 94 loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale; 95 return (nelem); 96 } 97