code: private void showAdminFormPreemption(PrintWriter out, boolean advancedView) {
      out.print("<h2>Task Preemption</h2>\n");
      String advParam = advancedView ? "&advanced" : "";
      out.print(generateSelect(Arrays.asList("On,Off".split(",")),
                scheduler.isPreemptionEnabled() ? "On" : "Off",
                "/fairscheduler?setPreemptionEnabled=<CHOICE>" + advParam));
    }
docs: Print the administration form for preemption