Power-Aware Operating Systems using ACPI

The idea behind today’s power management is to reduce the power usage of systems when someone walks away from their PC or stops using after a period of time, by sending the hardware into a “sleep mode” or “power-saving mode”. Hardware components such as processors, memory chips and disks have advanced power management techniques (besides “power-saving” modes) to consume less power. However, operating systems are being designed with little regard for power consumption. Even though, operating systems control hardware resources, and provide a virtualized interface for applications running on top it, they are largely unaware of power-saving optimizations that hardware has (does). With the prolific growth in the usage of laptops, PDAs, servers and workstations, operating systems and applications need to be aware of how much power they consume. In this project, we propose a model that uses the ACPI specifications to make operating systems and applications power-aware. The model uses an user-level power manager to make most of policy decisions for conserving power without significantly compromising performance. We use this model to implement hard-disk spin-down and temperature sensitive scheduler.