func Start() {
	p.Start()
}
Start the perf monitor
package perfm
import (
	"fmt"
	"math"
	"sort"
	"sync"
	"sync/atomic"
	"time"
	hist "github.com/arthurkiller/perfm/histogram"
)
type Job interface {
	Copy() (Job, error)
	Pre() error
	Do() error
	After()
}
type PerfMonitor interface {
	Regist(Job)  
	Start()      
}
func Regist(j Job) {
	p.Regist(j)
}