<system.web><trace enabled="true" pageOutput="true" requestLimit="40" localOnly="false"/></system.web>

protected override void OnResultExecuting(ResultExecutingContext filterContext)
    {
        string controller = filterContext.RouteData.Values["controller"].ToString();
        string action = filterContext.RouteData.Values["action"].ToString();
        start_time = DateTime.Now;
        System.Diagnostics.Trace.Write(string.Format("Start '{0}/{1}' on: {2}", controller, action, start_time));
    }

    protected override void OnResultExecuted(ResultExecutedContext filterContext)
    {
        string controller = filterContext.RouteData.Values["controller"].ToString();
        string action = filterContext.RouteData.Values["action"].ToString();
        var elapsed_time = DateTime.Now - start_time;
        System.Diagnostics.Trace.Write(string.Format("Start '{0}/{1}' on: {2}", controller, action, elapsed_time));
    }