A processor comprises a microarchitectural feature and dynamic tuning unit (DTU) circuitry. The processor executes a program for first and second execution windows with the microarchitectural feature disabled and enabled, respectively. The DTU circuitry automatically determines whether the processor achieved worse performance in the second execution window. In response to determining that the processor achieved worse performance in the second execution window, the DTU circuitry updates a usefulness state for a selected address of the program to denote worse performance. In response to multiple consecutive determinations that the processor achieved worse performance with the microarchitectural feature enabled, the DTU circuitry automatically updates the usefulness state to denote a confirmed bad state. In response to the usefulness state denoting the confirmed bad state, the DTU circuitry automatically disables the microarchitectural feature for the selected address for execution windows after the second execution window. Other embodiments are described and claimed.