1. A method for increasing energy-efficiency of a data processing system, the method comprising: continuously checking, by a processor executing a user-mode program in the data processing system, a plurality of I/O ports for incoming workload; responsive to the incoming workload being lower than a low workload threshold for a current operating frequency, reducing, by the processor, an operating frequency of the processor; and responsive to the incoming workload being higher than a high workload threshold, increasing, by the processor, the operating frequency of the processor.