1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 __SCCSID("@(#)kvm_getloadavg.c 8.1 (Berkeley) 6/4/93"); 35 36 #include <sys/param.h> 37 #include <sys/time.h> 38 #include <sys/resource.h> 39 40 #include <stdlib.h> 41 #include <limits.h> 42 #include <nlist.h> 43 #include <kvm.h> 44 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 (ISALIVE(kd)) 69 return (getloadavg(loadavg, nelem)); 70 71 if (!kd->arch->ka_native(kd)) { 72 _kvm_err(kd, kd->program, 73 "cannot read loadavg from non-native core"); 74 return (-1); 75 } 76 77 if (kvm_nlist(kd, nl) != 0) { 78 for (p = nl; p->n_type != 0; ++p); 79 _kvm_err(kd, kd->program, 80 "%s: no such symbol", p->n_name); 81 return (-1); 82 } 83 84 #define KREAD(kd, addr, obj) \ 85 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 86 if (KREAD(kd, nl[X_AVERUNNABLE].n_value, &loadinfo)) { 87 _kvm_err(kd, kd->program, "can't read averunnable"); 88 return (-1); 89 } 90 91 /* 92 * Old kernels have fscale separately; if not found assume 93 * running new format. 94 */ 95 if (!KREAD(kd, nl[X_FSCALE].n_value, &fscale)) 96 loadinfo.fscale = fscale; 97 98 nelem = MIN(nelem, (int)(sizeof(loadinfo.ldavg) / sizeof(fixpt_t))); 99 for (i = 0; i < nelem; i++) 100 loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale; 101 return (nelem); 102 } 103