1. A method comprising: by a processor of a computing device, executing a sequence of instructions that depends on one or more external operations; by software of the computing device, determining a clocking policy for the processor during execution of the sequence of instructions, the clocking policy being based at least in part on a pattern of execution involving the sequence of instructions and the external operations, the clocking policy modifying a clock speed of the processor; by the software of the computing device, applying the clocking policy to the processor during execution of at least a portion of the sequence of instructions.