Heterogeneous Memory Access Management Mechanism Based On Bank Partition

Due to the limitation of power consumption and manufacturing processes, traditional dynamic random access memory has low scalability and could not meet the needs of modern large-scale data processing applications while emerging non-volatile memory is expected to solve this problem. But non-volatile memory has long access latency and a short lifetime, the industry generally favor both of them as main memory of a computer system, constituting a heterogeneous memory system. However, different memory media and access characteristics make the traditional memory access optimizations not applicable for the heterogeneous memory system. Hence, research for new memory access optimization for heterogeneous memory environment is needed.HMBP, a heterogeneous memory access management mechanism based on bank partition, introduced bank partition into the heterogeneous memory system. It allocates banks to processes according to their memory access characteristics and makes them can only access the banks that assigned to them to reduce memory access interference, improve row buffer hit rate, and enhance memory access performance in multicore environment. Considering different memory media and access characteristics, HMBP proposed a strategy that decides the memory media every process can have by analyzing the profit system can gained dynamically, resulting in a bank partition mechanism which is more applicable for heterogeneous memory environment, and improves system performance furtherly. Moreover, HMBP propose a strategy that decides specific banks for every process to reduce the amount and impact on system performance of data migration between banks.The experiment results indicate that HMBP can improve system throughput and fairness significantly. For sences including lots of memory intensive applications with high row buffer locality, compared to the first ready first come first served scheduling policy which is used widely in memory controller, system throughput improves up to 9% in average, and compared to dynamic bank partition, which is not optimized for heterogeneous memory environments, it improves 3% in average. Furthermore, compared to dynamic bank partition with experiment results of 20 benchmark groups, HMBP's system fairness increased by more than 33% in average.