Multicore power management: Ensuring robustness via early-stage formal verification

Dynamic power management (DPM) is important for multicore architectures. One important challenge for multicore DPM schemes is verifying that they are both safe (cannot lead to power or thermal catastrophes) and efficient (achieve as much performance as possible without exceeding power constraints). The verification difficulty varies among designs, depending, for example, on the particular power management mechanisms utilized and the algorithms used to adjust them. However, verification effort is often not considered in the early stages of DPM scheme design, leading to proposals that can be extremely difficult to verify. To address this problem, we propose using formal verification (with probabilistic model checking) of a high-level, early-stage model of the DPM scheme. Using the model checker, we estimate the required verification effort, providing insight on how certain design parameters impact this effort. Furthermore, we supplement the verifiability results with high-level estimates of power consumption and performance, which allow us to perform a trade-off analysis between power, performance, and verification. We show that this trade-off analysis uncovers design points that are better than those that consider only power and performance.