// Expose CPU stats using KVM.
func (c *statCollector) Update(ch chan<- prometheus.Metric) (err error) {
if os.Geteuid() != 0 && os.Getegid() != 2 {
return errors.New("caller should be either root user or kmem group to access /dev/mem")
}
var errbuf *C.char
kd := C.kvm_open(nil, nil, nil, C.O_RDONLY, errbuf)
if errbuf != nil {
return errors.New("failed to call kvm_open()")
}
defer C.kvm_close(kd)
// The cp_time variable is an array of CPUSTATES long integers -- in
// the same format as the kern.cp_time sysctl. According to the
// comments in sys/kern/kern_clock.c, the frequency of this timer will
// be stathz (or hz, if stathz is zero).
clockrate, err := getClockRate()
if err != nil {
return err
}
ncpus := C.kvm_getncpus(kd)
for i := 0; i < int(ncpus); i++ {
pcpu := C.kvm_getpcpu(kd, C.int(i))
cp_time := ((*C.struct_pcpu)(unsafe.Pointer(pcpu))).pc_cp_time
c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "user"}).Set(float64(cp_time[C.CP_USER]) / clockrate)
c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "nice"}).Set(float64(cp_time[C.CP_NICE]) / clockrate)
c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "system"}).Set(float64(cp_time[C.CP_SYS]) / clockrate)
c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "interrupt"}).Set(float64(cp_time[C.CP_INTR]) / clockrate)
c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "idle"}).Set(float64(cp_time[C.CP_IDLE]) / clockrate)
}
c.cpu.Collect(ch)
return err
}
// Expose CPU stats using KVM.
func (c *statCollector) Update(ch chan<- prometheus.Metric) (err error) {
if os.Geteuid() != 0 && os.Getegid() != 2 {
return errors.New("caller should be either root user or kmem group to access /dev/mem")
}
var errbuf *C.char
kd := C.kvm_open(nil, nil, nil, C.O_RDONLY, errbuf)
if errbuf != nil {
return errors.New("failed to call kvm_open()")
}
defer C.kvm_close(kd)
ncpus := C.kvm_getncpus(kd)
for i := 0; i < int(ncpus); i++ {
pcpu := C.kvm_getpcpu(kd, C.int(i))
cp_time := ((*C.struct_pcpu)(unsafe.Pointer(pcpu))).pc_cp_time
c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "user"}).Set(float64(cp_time[C.CP_USER]))
c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "nice"}).Set(float64(cp_time[C.CP_NICE]))
c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "system"}).Set(float64(cp_time[C.CP_SYS]))
c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "interrupt"}).Set(float64(cp_time[C.CP_INTR]))
c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(i), "mode": "idle"}).Set(float64(cp_time[C.CP_IDLE]))
}
c.cpu.Collect(ch)
return err
}