Energy efficiency is a crucial desideratum in the design of computer systems, from small-sized mobile devices with limited battery to large scale data centers. In such computing systems, processors and memory are considered as two major power consumers among all the system components. One recent trend to reduce power consumption is using shared memory in multi-core systems, such architecture has become ubiquitous nowadays. However, implementing the energy-efficient methods to the multi-core processor and the shared memory separately is not trivial. In this work, we consider the energy-efficient task scheduling problem, which coordinates the power consumption of both the multi-core processor and the shared memory, especially focus on the general situation in which the number of tasks is more than the number of cores. We devise an approximation algorithm with guaranteed performance in the multiple cores system. We tackle the problem by first presenting an optimal algorithm when the assignment of tasks to cores is given. Then we propose an approximation assignment for the general task scheduling.

从电池电量有限的小型移动设备到大型数据中心，能源效率是计算机系统设计中的关键要求。在这样的计算系统中，处理器和存储器被认为是所有系统组件中的两个主要功耗器。减少功耗的最新趋势是在多核系统中使用共享内存，这种架构如今已无处不在。但是，分别对多核处理器和共享内存实施节能方法并非易事。在这项工作中，我们考虑了节能任务调度问题，该问题协调了多核处理器和共享内存的功耗，尤其着重于任务数大于内核数的一般情况。 。我们设计了一种在多核系统中具有保证性能的近似算法。当给核心分配任务时，我们首先提出一种最佳算法来解决这个问题。然后，我们为一般任务调度提出了一个近似分配。