1 /*- 2 * Copyright (c) 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #if defined(LIBC_SCCS) && !defined(lint) 9 static char sccsid[] = "@(#)kvm_getloadavg.c 8.1 (Berkeley) 06/04/93"; 10 #endif /* LIBC_SCCS and not lint */ 11 12 #include <sys/param.h> 13 #include <sys/time.h> 14 #include <sys/resource.h> 15 #include <sys/proc.h> 16 #include <sys/sysctl.h> 17 #include <vm/vm_param.h> 18 19 #include <db.h> 20 #include <fcntl.h> 21 #include <limits.h> 22 #include <nlist.h> 23 #include <kvm.h> 24 25 #include "kvm_private.h" 26 27 static struct nlist nl[] = { 28 { "_averunnable" }, 29 #define X_AVERUNNABLE 0 30 { "_fscale" }, 31 #define X_FSCALE 1 32 { "" }, 33 }; 34 35 /* 36 * kvm_getloadavg() -- Get system load averages, from live or dead kernels. 37 * 38 * Put `nelem' samples into `loadavg' array. 39 * Return number of samples retrieved, or -1 on error. 40 */ 41 int 42 kvm_getloadavg(kd, loadavg, nelem) 43 kvm_t *kd; 44 double loadavg[]; 45 int nelem; 46 { 47 struct loadavg loadinfo; 48 struct nlist *p; 49 int fscale, i; 50 51 if (ISALIVE(kd)) 52 return (getloadavg(loadavg, nelem)); 53 54 if (kvm_nlist(kd, nl) != 0) { 55 for (p = nl; p->n_type != 0; ++p); 56 _kvm_err(kd, kd->program, 57 "%s: no such symbol", p->n_name); 58 return (-1); 59 } 60 61 #define KREAD(kd, addr, obj) \ 62 (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj)) 63 if (KREAD(kd, nl[X_AVERUNNABLE].n_value, &loadinfo)) { 64 _kvm_err(kd, kd->program, "can't read averunnable"); 65 return (-1); 66 } 67 68 /* 69 * Old kernels have fscale separately; if not found assume 70 * running new format. 71 */ 72 if (!KREAD(kd, nl[X_FSCALE].n_value, &fscale)) 73 loadinfo.fscale = fscale; 74 75 nelem = MIN(nelem, sizeof(loadinfo.ldavg) / sizeof(fixpt_t)); 76 for (i = 0; i < nelem; i++) 77 loadavg[i] = (double) loadinfo.ldavg[i] / loadinfo.fscale; 78 return (nelem); 79 } 80