A data processing apparatus has processing circuitry which can execute instructions at one of several privilege levels. A plurality of performance monitoring circuits are included. In response to an instruction executed at a first privilege level, first configuration data can be set for controlling performance monitoring by a first subset of performance monitoring circuits. A disable control flag can be set in response to an instruction executed at a second privilege level higher than the first privilege level. If the disable control flag has a predetermined value then performance monitoring control circuitry disables performance monitoring by the first subset of performance monitoring circuits while the processing circuitry is executing instructions at the second privilege level.