Hands-On High Performance Programming with Qt 5

Run to idle

Modern embedded and mobile devices are trying to save battery life in many different ways. One technique we know from laptop computers is the dynamic down-clocking of CPUs to match the current performance requirements. Another technique is the so-called big.LITTLE architecture of ARM, where we pair a powerful but power-hungry processor with a smaller but a more power-friendly one, ensuring cache coherence between them and switching to one or the another, depending on the amount of work to be done.

The OS will control the dynamic CPU frequency, in the case of embedded Linux through the frequency driver, as well as switching between the small and big cores in the big.LITTLE architecture. On a mobile OS such as Android, the kernel ...