中文摘要：

多核系统中,内存子系统消耗大量的能耗并且比例还会继续增大.因此,解决内存的功耗问题成为系统功耗优化的关键.根据线程的内存地址空间和负载均衡策略将系统中的线程划分成不同的线程组,根据线程所属的组,给同一组内的线程分配相同内存 rank 中的物理页,然后,根据划分的线程组以组为单位进行调度.提出了结合页分配和组调度的内存功耗优化方法（CAS）.CAS 周期性地激活当前需要的内存 rank,从而可以将暂时不使用的内存 rank置为低功耗状态,同时延长低功耗内存 rank 的空闲时间.仿真实验结果显示：与其他同类方法相比,CAS 方法能够平均降低10%的内存功耗,同时提高8%的性能.

英文摘要：

Main memory accounts for a large and increasing fraction of the energy consumption in multi-core systems. Therefore, it is critical to address the power issue in the memory subsystem. This paper presents a solution to improve memory power efficiency through coordinating page allocation and thread group scheduling （CAS）. Under the proposed page allocation, all threads are partitioned into different thread groups, where threads in the same thread group occupy the same memory rank. Thread group scheduling is then implemented by adjusting default Linux CFS. The CAS alternates active partial memory periodically to allow others power down and prolongs the idle ranks. Experimental results show that this approach improves energy saving by 10% and reduces performance overhead by 8% comparing with the state of the art polices.