Research Of DVS Algorithm Based On Mixed Task Scheduling

Energy consumption of computer systems has become an increasingly important design issue. Dynamic voltage scaling (DVS) is an effective technology to reduce processor's power consumption. Dynamic voltage scaling techniques are often associated with compiler technology, task scheduling technology and multi-core technology to achieve energy-saving purpose.The main creative work of this thesis are as follows:1. Proposed an interval-based AIBD DVS algorithm and developed AIBD governor on linux Cpufreq kernel module. The AIBD DVS algorithm was carried out in Lenovo Y430A-TSI laptop computer. The thesis takes full advantage of Cpufreq_Stats module to record the number of user time clock cycles on different frequencies during the excution of the test programme. then based on the user time clock cycles, the thesis established an power analysis method. Experiments indicate that, compared with PAST algorithm, the AIBD DVS algorithm can effectively reduce processor's power consumption on different types of task sets.2. Tasks executed in open mobile systems often consist of BE tasks and some soft real-time multimedia tasks. In view of this special platform, the thesis proposed two kinds of DVS algorithms, that is utilization-based SRT-DVS and bandwidth reclamation SRT-DVS, and introduced a two-level hierarchical scheduling scheme named SRT scheduling scheme which integrated SRT-DVS into soft real-time scheduling for open mobile systems. Simulation shows that, the two SRT-DVS algorithms can effectively reduce processor's energy consumtion in open mobile systems while slightly effecting it's performance.