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 35 #if defined(LIBC_SCCS) && !defined(lint) 36 #if 0 37 static char sccsid[] = "@(#)kvm_getloadavg.c 8.1 (Berkeley) 6/4/93"; 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 45 #include <stdlib.h> 46 #include <limits.h> 47 #include <nlist.h> 48 #include <kvm.h> 49 50 #include "kvm_private.h" 51 52 static struct nlist nl[] = { 53 { .n_name = "_averunnable" }, 54 #define X_AVERUNNABLE 0 55 { .n_name = "_fscale" }, 56 #define X_FSCALE 1 57 { .n_name = "" }, 58 }; 59 60 /* 61 * kvm_getloadavg() -- Get system load averages, from live or dead kernels. 62 * 63 * Put `nelem' samples into `loadavg' array. 64 * Return number of samples retrieved, or -1 on error. 65 */ 66 int 67 kvm_getloadavg(kvm_t *kd, double loadavg[], int nelem) 68 { 69 struct loadavg loadinfo; 70 struct nlist *p; 71 int fscale, i; 72 73 if (ISALIVE(kd)) 74 return (getloadavg(loadavg, nelem)); 75 76 if (!kd->arch->ka_native(kd)) { 77 _kvm_err(kd, kd->program, 78 "cannot read loadavg from non-native core"); 79 return (-1); 80 } 81 82 if (kvm_nlist(kd, nl) != 0) { 83 for (p = nl; p->n_type != 0; ++p); 84 _kvm_err(kd, kd->program, 85 "%s: no such symbol", p->n_name); 86 return (-1); 87 } 88 89 #define KREAD(kd, addr, obj) \ 90 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 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, (int)(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