An information processing apparatus comprising: processing circuitry configured to execute instructions comprising one or more time intensive instructions; and exception generating circuitry configured to generate at least one exception for said processing circuitry, wherein said processing circuitry is configured to maintain a control value for indicating whether said time intensive instructions can be executed; wherein said processing circuitry is configured to execute first software at a first privilege level and to execute second software at a second privilege level higher than the first privilege level; wherein said second software is configured to control said processing circuitry to change said control value; wherein said exception generating circuitry is configured, in response to one of said time intensive instructions when said control value is in a first state indicating that said time intensive instructions cannot be executed, to generate a first exception to trigger the processing circuitry to suppress execution of said one of said time intensive instructions, wherein said second software causes said first software for which a time intensive instruction occurs as part of a first task to issue a context switch in order to switch out this task that causes said time intensive instruction to be executed and instead execute a different task; and wherein said exception generating circuitry is configured, in response to one of said time intensive instructions when said control value is in a second state indicating that said time intensive instructions can be executed, to execute said one of said time intensive instructions. processing circuitry configured to execute instructions comprising one or more time intensive instructions; and exception generating circuitry configured to generate at least one exception for said processing circuitry, wherein said processing circuitry is configured to maintain a control value for indicating whether said time intensive instructions can be executed; wherein said processing circuitry is configured to execute first software at a first privilege level and to execute second software at a second privilege level higher than the first privilege level; wherein said second software is configured to control said processing circuitry to change said control value; wherein said exception generating circuitry is configured, in response to one of said time intensive instructions when said control value is in a first state indicating that said time intensive instructions cannot be executed, to generate a first exception to trigger the processing circuitry to suppress execution of said one of said time intensive instructions, wherein said second software causes said first software for which a time intensive instruction occurs as part of a first task to issue a context switch in order to switch out this task that causes said time intensive instruction to be executed and instead execute a different task; and wherein said exception generating circuitry is configured, in response to one of said time intensive instructions when said control value is in a second state indicating that said time intensive instructions can be executed, to execute said one of said time intensive instructions.