LUIZ, S. O. D.; http://lattes.cnpq.br/5704594745207397; LUIZ, Saulo Oliveira Dornellas.
Abstract:
The need to save power is present in almost every computer system. To handle this increasing
demand for power management, the semiconductor manufacturers have been developing several
low power design techniques, such as: low power states, dynamic voltage and frequency
scaling, and clock gating. For example, in the case of processor power management at the operating
system level, the goal is to choose the most suitable pair of voltage and frequency to
minimize the power consumption and guarantee the performance level desired by the user. A
great challenge for the dynamic powermanagement of general purpose computer systems is that
the system workload is initially unknown and time-variant. Therefore it is necessary a power
manager, where the system power states are choosen by means of a procedure named power
management policy. In the literature, there are many power management policies which are
claimed to be optimum for specific targeted systems. Furthermore, most of those policies may
be considered as open loop policies, because, during execution time, the system performance
is not compared to a specified reference performance value. To guarantee that the system performance
is equal to a specified reference performance value, closed loop control techniques
have been applied to the power management problem at several cases, such as, the applications
performance, the utilization of an embedded microprocessor running a known set of real-time
control tasks, the occupancy of a buffer in a multimedia decoder, etc.. In thisWork, an adaptive
control technique for dynamic power management was developed with the goal of guaranteeing
a specified reference performance value and minimizing the power consumption of a processor
with dynamic voltage and frequency scaling, considering that the system workload is initially
unknown and time-variant. This technique was conceived to be as general as possible, so that
it may be used for different types of computer systems. In the experimental results, the developed
adaptive control technique outperformed other state-of-the art policies both in power and
system performance.