Monitoring system activity for OS-directed dynamic power management

We describe a workload monitoring system that has been specifically designed for supporting dynamic power management in personal computers with tight power constraints (such as laptop or notebook computers). Our monitoring system is minimally intrusive, and has negligible impact on system activity. Moreover, it can be used both for on-line system monitoring and off-line data collection. We used our monitoring tool to collect data on the usage of system resources (disks, CPU, keyboard and mouse) for a laptop computer, under several workload conditions. Our analysis shows that resource usage is strongly resource and workload dependent, and that on-line usage monitoring capability is a critical issue of the implementation of effective power management policies.