code: public void setBackgroundPeriod(long period)
    {
      if (period < 1) {
        throw new ConfigException(L.l("profile period '{0}ms' is too small.  The period must be greater than 10ms.",
                                      period));
      }
  
      _profilerService.setBackgroundInterval(period, TimeUnit.MILLISECONDS);
    }
docs: Sets the background interval. If the background profile hasn't started, start it.