The general purpose of operating systems like Linux, thanks to their predisposition to adapt easily to different application contexts, is a common choice for many new generation mobile devices. Being a key feature to improve mobility, energy efficiency has become a high priority design goal, and the implementation of the necessary mechanisms to optimize both power and performances can no longer be separated from the requirements of ease of development, portability and adaptability. This work presents a formal model to define the problem of power vs performance control. We have proven that a distributed control is particularly suited to meet the goals of both adaptability and portability, without unduly compromising the effectiveness of control and its efficiency. Starting from the current Linux solution we will advance the proposal for an extension that is better tailored to embedded mobile systems. The proposed solution has been implemented in a new Linux kernel framework named CPM which is competitive in adaptability and ensures better control on performances while still not affecting ease of implementation.