wmcpuload/src/cpu_netbsd.c

   1 /*
   2  * cpu_netbsd - module to get cpu usage, for NetBSD
   3  *
   4  * This code is based on cpu_openbsd.c
   5  *
   6  * Copyright (c) 2001, 2002 Seiichi SATO <ssato@sh.rim.or.jp>
   7  * Copyright (c) 2002 Thomas Runge <coto@core.de>
   8  * Copyright (C) 2003 Nedko Arnaudov <nedko@users.sourceforge.net>
   9  *
  10  * Licensed under the GPL
  11  */
  12
  13 #ifdef HAVE_CONFIG_H
  14 #include "config.h"
  15 #endif
  16
  17 #include <stdio.h>
  18 #include <unistd.h>
  19 #include <stdlib.h>
  20 #include <string.h>
  21 #include "cpu.h"
  22
  23 #include <sys/types.h>
  24 #include <sys/param.h>
  25 #include <sys/sysctl.h>
  26 #include <sys/sched.h>
  27
  28 void
  29 cpu_init(void)
  30 {
  31     /* You don't need initialization under NetBSD */
  32     return;
  33 }
  34
  35 /* Returns the current CPU usage in percent */
  36 int
  37 cpu_get_usage(cpu_options *opts)
  38 {
  39     int total, used, result, idle;
  40     static int pre_total, pre_used, pre_idle;
  41
  42     int mib[] = { CTL_KERN, KERN_CP_TIME };
  43     u_int64_t cpu_time[CPUSTATES];
  44     size_t size = sizeof(cpu_time);
  45
  46     /* get cpu time via sysctl */
  47     if (sysctl(mib, 2, &cpu_time, &size, NULL, 0) < 0)
  48         return 0;
  49
  50     /* calculate usage */
  51     total = cpu_time[CP_USER] + cpu_time[CP_SYS] + cpu_time[CP_INTR] +
  52             cpu_time[CP_NICE] + cpu_time[CP_IDLE];
  53     used = cpu_time[CP_USER] + cpu_time[CP_SYS] + cpu_time[CP_INTR] +
  54            (opts->ignore_nice ? 0 : cpu_time[CP_NICE]);
  55     if ((pre_total == 0) || !(total - pre_total > 0)) {
  56         result = 0;
  57     } else {
  58         result = 100 * (double)(used - pre_used) / (double)(total - pre_total);
  59     }
  60
  61     /* save used/total for next calculation */
  62     pre_used = used;
  63     pre_total = total;
  64
  65     return result;
  66 }