kvm_getloadavg.c revision 84768
119370Spst/*- 219370Spst * Copyright (c) 1993 398948Sobrien * The Regents of the University of California. All rights reserved. 4130809Smarcel * 5130809Smarcel * Redistribution and use in source and binary forms, with or without 619370Spst * modification, are permitted provided that the following conditions 798948Sobrien * are met: 819370Spst * 1. Redistributions of source code must retain the above copyright 998948Sobrien * notice, this list of conditions and the following disclaimer. 1098948Sobrien * 2. Redistributions in binary form must reproduce the above copyright 1198948Sobrien * notice, this list of conditions and the following disclaimer in the 1298948Sobrien * documentation and/or other materials provided with the distribution. 1319370Spst * 3. All advertising materials mentioning features or use of this software 1498948Sobrien * must display the following acknowledgement: 1598948Sobrien * This product includes software developed by the University of 1698948Sobrien * California, Berkeley and its contributors. 1798948Sobrien * 4. Neither the name of the University nor the names of its contributors 1819370Spst * may be used to endorse or promote products derived from this software 1998948Sobrien * without specific prior written permission. 2098948Sobrien * 2198948Sobrien * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2298948Sobrien * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2319370Spst * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2498948Sobrien * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2519370Spst * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2619370Spst * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2719370Spst * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2846289Sdfr * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2919370Spst * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3019370Spst * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3119370Spst * SUCH DAMAGE. 3219370Spst */ 3319370Spst 3498948Sobrien#include <sys/cdefs.h> 3519370Spst__FBSDID("$FreeBSD: head/lib/libkvm/kvm_getloadavg.c 84768 2001-10-10 17:48:44Z bde $"); 3619370Spst 3719370Spst#if defined(LIBC_SCCS) && !defined(lint) 3846289Sdfr#if 0 3998948Sobrienstatic char sccsid[] = "@(#)kvm_getloadavg.c 8.1 (Berkeley) 6/4/93"; 4098948Sobrien#endif 4198948Sobrien#endif /* LIBC_SCCS and not lint */ 4298948Sobrien 4319370Spst#include <sys/param.h> 4498948Sobrien#include <sys/time.h> 4598948Sobrien#include <sys/resource.h> 4619370Spst#include <sys/proc.h> 4719370Spst#include <sys/sysctl.h> 4819370Spst#include <vm/vm_param.h> 4919370Spst 5098948Sobrien#include <stdlib.h> 5198948Sobrien#include <fcntl.h> 5298948Sobrien#include <limits.h> 5398948Sobrien#include <nlist.h> 5419370Spst#include <kvm.h> 5519370Spst 5619370Spst#include "kvm_private.h" 5798948Sobrien 5898948Sobrienstatic struct nlist nl[] = { 59130809Smarcel { "_averunnable" }, 60130809Smarcel#define X_AVERUNNABLE 0 6119370Spst { "_fscale" }, 6298948Sobrien#define X_FSCALE 1 6398948Sobrien { "" }, 6498948Sobrien}; 6519370Spst 6698948Sobrien/* 6798948Sobrien * kvm_getloadavg() -- Get system load averages, from live or dead kernels. 6898948Sobrien * 6998948Sobrien * Put `nelem' samples into `loadavg' array. 7019370Spst * Return number of samples retrieved, or -1 on error. 7198948Sobrien */ 7219370Spstint 7398948Sobrienkvm_getloadavg(kd, loadavg, nelem) 7419370Spst kvm_t *kd; 7598948Sobrien double loadavg[]; 7698948Sobrien int nelem; 7798948Sobrien{ 7898948Sobrien struct loadavg loadinfo; 7919370Spst struct nlist *p; 8098948Sobrien int fscale, i; 8119370Spst 8298948Sobrien if (ISALIVE(kd)) 8319370Spst return (getloadavg(loadavg, nelem)); 8498948Sobrien 8598948Sobrien if (kvm_nlist(kd, nl) != 0) { 8698948Sobrien for (p = nl; p->n_type != 0; ++p); 8798948Sobrien _kvm_err(kd, kd->program, 88130809Smarcel "%s: no such symbol", p->n_name); 8919370Spst return (-1); 9098948Sobrien } 9198948Sobrien 9219370Spst#define KREAD(kd, addr, obj) \ 9398948Sobrien (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 9498948Sobrien if (KREAD(kd, nl[X_AVERUNNABLE].n_value, &loadinfo)) { 9519370Spst _kvm_err(kd, kd->program, "can't read averunnable"); 96130809Smarcel return (-1); 97130809Smarcel } 9819370Spst 9998948Sobrien /* 10019370Spst * Old kernels have fscale separately; if not found assume 10198948Sobrien * running new format. 10219370Spst */ 10398948Sobrien if (!KREAD(kd, nl[X_FSCALE].n_value, &fscale)) 10498948Sobrien loadinfo.fscale = fscale; 10519370Spst 10698948Sobrien nelem = MIN(nelem, sizeof(loadinfo.ldavg) / sizeof(fixpt_t)); 10719370Spst for (i = 0; i < nelem; i++) 10898948Sobrien loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale; 10919370Spst return (nelem); 11098948Sobrien} 11198948Sobrien