| 摘要 |
A processor has a flag indicating whether time consuming instructions should be executed. When the flag has a first value, the instructions are executed. When the flag has a second value, an exception is generated if the processor attempts to execute one of the instructions. The instructions may be non-interruptible instructions, which take a large number of clock cycles, such as floating point square root instructions, a divide instructions, multiple load instructions or multiple store instructions. Changing the flag value may be restricted to high privilege software, such as a hypervisor. The processor may execute the instructions when executing high privilege software, regardless of the flag value. The processor may change the flag value in response to a context switch or an exception. An exception may be generated a predetermined period before a real time event. |
