kvm_getloadavg.c revision 1573
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) 351573Srgrimesstatic char sccsid[] = "@(#)kvm_getloadavg.c 8.1 (Berkeley) 6/4/93"; 361573Srgrimes#endif /* LIBC_SCCS and not lint */ 371573Srgrimes 381573Srgrimes#include <sys/param.h> 391573Srgrimes#include <sys/time.h> 401573Srgrimes#include <sys/resource.h> 411573Srgrimes#include <sys/proc.h> 421573Srgrimes#include <sys/sysctl.h> 431573Srgrimes#include <vm/vm_param.h> 441573Srgrimes 451573Srgrimes#include <db.h> 461573Srgrimes#include <fcntl.h> 471573Srgrimes#include <limits.h> 481573Srgrimes#include <nlist.h> 491573Srgrimes#include <kvm.h> 501573Srgrimes 511573Srgrimes#include "kvm_private.h" 521573Srgrimes 531573Srgrimesstatic struct nlist nl[] = { 541573Srgrimes { "_averunnable" }, 551573Srgrimes#define X_AVERUNNABLE 0 561573Srgrimes { "_fscale" }, 571573Srgrimes#define X_FSCALE 1 581573Srgrimes { "" }, 591573Srgrimes}; 601573Srgrimes 611573Srgrimes/* 621573Srgrimes * kvm_getloadavg() -- Get system load averages, from live or dead kernels. 631573Srgrimes * 641573Srgrimes * Put `nelem' samples into `loadavg' array. 651573Srgrimes * Return number of samples retrieved, or -1 on error. 661573Srgrimes */ 671573Srgrimesint 681573Srgrimeskvm_getloadavg(kd, loadavg, nelem) 691573Srgrimes kvm_t *kd; 701573Srgrimes double loadavg[]; 711573Srgrimes int nelem; 721573Srgrimes{ 731573Srgrimes struct loadavg loadinfo; 741573Srgrimes struct nlist *p; 751573Srgrimes int fscale, i; 761573Srgrimes 771573Srgrimes if (ISALIVE(kd)) 781573Srgrimes return (getloadavg(loadavg, nelem)); 791573Srgrimes 801573Srgrimes if (kvm_nlist(kd, nl) != 0) { 811573Srgrimes for (p = nl; p->n_type != 0; ++p); 821573Srgrimes _kvm_err(kd, kd->program, 831573Srgrimes "%s: no such symbol", p->n_name); 841573Srgrimes return (-1); 851573Srgrimes } 861573Srgrimes 871573Srgrimes#define KREAD(kd, addr, obj) \ 881573Srgrimes (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 891573Srgrimes if (KREAD(kd, nl[X_AVERUNNABLE].n_value, &loadinfo)) { 901573Srgrimes _kvm_err(kd, kd->program, "can't read averunnable"); 911573Srgrimes return (-1); 921573Srgrimes } 931573Srgrimes 941573Srgrimes /* 951573Srgrimes * Old kernels have fscale separately; if not found assume 961573Srgrimes * running new format. 971573Srgrimes */ 981573Srgrimes if (!KREAD(kd, nl[X_FSCALE].n_value, &fscale)) 991573Srgrimes loadinfo.fscale = fscale; 1001573Srgrimes 1011573Srgrimes nelem = MIN(nelem, sizeof(loadinfo.ldavg) / sizeof(fixpt_t)); 1021573Srgrimes for (i = 0; i < nelem; i++) 1031573Srgrimes loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale; 1041573Srgrimes return (nelem); 1051573Srgrimes} 106