func New() (CpuLoadReader, error) {
reader, err := netlink.New()
if err != nil {
return nil, fmt.Errorf("failed to create a netlink based cpuload reader: %v", err)
}
glog.V(3).Info("Using a netlink-based load reader")
return reader, nil
}
func New() (CpuLoadReader, error) {
// First try to create a scheddebug based load reader.
schedReader, schedErr := scheddebug.New()
if schedErr == nil {
glog.Info("Using a sched debug based load reader")
return schedReader, nil
}
glog.V(1).Infof("failed to create a scheddebug-based cpu load reader: %v", schedErr)
// netlink gives us more data than scheddebug, but it doesn't work inside network namespaces. It also needs to be hierarchical.
reader, err := netlink.New()
if err != nil {
return nil, fmt.Errorf("failed to create any cpu load reader - netlink based (%v), scheddebug based (%v)", err, schedErr)
}
glog.Info("Using a netlink-based load reader")
return reader, nil
}
func main() {
n, err := netlink.New()
if err != nil {
log.Printf("Failed to create cpu load util: %s", err)
return
}
defer n.Stop()
paths := []string{"/sys/fs/cgroup/cpu", "/sys/fs/cgroup/cpu/docker"}
names := []string{"/", "/docker"}
for i, path := range paths {
stats, err := n.GetCpuLoad(names[i], path)
if err != nil {
log.Printf("Error getting cpu load for %q: %s", path, err)
}
log.Printf("Task load for %s: %+v", path, stats)
}
}