code: func (s *poolStats) recalc() {
  	now := mclock.Now()
  	s.recent = s.avg + (s.recent-s.avg)*math.Exp(-float64(now-s.lastRecalc)/float64(pstatReturnToMeanTC))
  	if s.sum == 0 {
  		s.avg = 0
  	} else {
  		if s.sum > s.weight*1e30 {
  			s.avg = 1e30
  		} else {
  			s.avg = s.sum / s.weight
  		}
  	}
  	s.lastRecalc = now
  }
docs: // recalc recalculates recent value return-to-mean and long term average