kvm_getloadavg.c revision 55127
11573Srgrimes/*- 21573Srgrimes * Copyright (c) 1993 31573Srgrimes * The Regents of the University of California. All rights reserved. 41573Srgrimes * 51573Srgrimes * Redistribution and use in source and binary forms, with or without 61573Srgrimes * modification, are permitted provided that the following conditions 71573Srgrimes * are met: 81573Srgrimes * 1. Redistributions of source code must retain the above copyright 91573Srgrimes * notice, this list of conditions and the following disclaimer. 101573Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111573Srgrimes * notice, this list of conditions and the following disclaimer in the 121573Srgrimes * documentation and/or other materials provided with the distribution. 131573Srgrimes * 3. All advertising materials mentioning features or use of this software 141573Srgrimes * must display the following acknowledgement: 151573Srgrimes * This product includes software developed by the University of 161573Srgrimes * California, Berkeley and its contributors. 171573Srgrimes * 4. Neither the name of the University nor the names of its contributors 181573Srgrimes * may be used to endorse or promote products derived from this software 191573Srgrimes * without specific prior written permission. 201573Srgrimes * 211573Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221573Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231573Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241573Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251573Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261573Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271573Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281573Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291573Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301573Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311573Srgrimes * SUCH DAMAGE. 321573Srgrimes */ 331573Srgrimes 341573Srgrimes#if defined(LIBC_SCCS) && !defined(lint) 3555127Speter#if 0 361573Srgrimesstatic char sccsid[] = "@(#)kvm_getloadavg.c 8.1 (Berkeley) 6/4/93"; 3755127Speter#else 3855127Speterstatic const char rcsid[] = 3955127Speter "$FreeBSD: head/lib/libkvm/kvm_getloadavg.c 55127 1999-12-27 07:14:58Z peter $"; 4055127Speter#endif 411573Srgrimes#endif /* LIBC_SCCS and not lint */ 421573Srgrimes 431573Srgrimes#include <sys/param.h> 441573Srgrimes#include <sys/time.h> 451573Srgrimes#include <sys/resource.h> 461573Srgrimes#include <sys/proc.h> 471573Srgrimes#include <sys/sysctl.h> 481573Srgrimes#include <vm/vm_param.h> 491573Srgrimes 5017141Sjkh#include <stdlib.h> 511573Srgrimes#include <fcntl.h> 521573Srgrimes#include <limits.h> 531573Srgrimes#include <nlist.h> 541573Srgrimes#include <kvm.h> 551573Srgrimes 561573Srgrimes#include "kvm_private.h" 571573Srgrimes 581573Srgrimesstatic struct nlist nl[] = { 591573Srgrimes { "_averunnable" }, 601573Srgrimes#define X_AVERUNNABLE 0 611573Srgrimes { "_fscale" }, 621573Srgrimes#define X_FSCALE 1 631573Srgrimes { "" }, 641573Srgrimes}; 651573Srgrimes 661573Srgrimes/* 671573Srgrimes * kvm_getloadavg() -- Get system load averages, from live or dead kernels. 681573Srgrimes * 691573Srgrimes * Put `nelem' samples into `loadavg' array. 701573Srgrimes * Return number of samples retrieved, or -1 on error. 711573Srgrimes */ 721573Srgrimesint 731573Srgrimeskvm_getloadavg(kd, loadavg, nelem) 741573Srgrimes kvm_t *kd; 751573Srgrimes double loadavg[]; 761573Srgrimes int nelem; 771573Srgrimes{ 781573Srgrimes struct loadavg loadinfo; 791573Srgrimes struct nlist *p; 801573Srgrimes int fscale, i; 811573Srgrimes 821573Srgrimes if (ISALIVE(kd)) 831573Srgrimes return (getloadavg(loadavg, nelem)); 841573Srgrimes 851573Srgrimes if (kvm_nlist(kd, nl) != 0) { 861573Srgrimes for (p = nl; p->n_type != 0; ++p); 871573Srgrimes _kvm_err(kd, kd->program, 881573Srgrimes "%s: no such symbol", p->n_name); 891573Srgrimes return (-1); 901573Srgrimes } 911573Srgrimes 921573Srgrimes#define KREAD(kd, addr, obj) \ 931573Srgrimes (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 941573Srgrimes if (KREAD(kd, nl[X_AVERUNNABLE].n_value, &loadinfo)) { 951573Srgrimes _kvm_err(kd, kd->program, "can't read averunnable"); 961573Srgrimes return (-1); 971573Srgrimes } 981573Srgrimes 991573Srgrimes /* 1001573Srgrimes * Old kernels have fscale separately; if not found assume 1011573Srgrimes * running new format. 1021573Srgrimes */ 1031573Srgrimes if (!KREAD(kd, nl[X_FSCALE].n_value, &fscale)) 1041573Srgrimes loadinfo.fscale = fscale; 1051573Srgrimes 1061573Srgrimes nelem = MIN(nelem, sizeof(loadinfo.ldavg) / sizeof(fixpt_t)); 1071573Srgrimes for (i = 0; i < nelem; i++) 1081573Srgrimes loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale; 1091573Srgrimes return (nelem); 1101573Srgrimes} 111