Pseudo Share: Bring Shared to Exclusive for Main Memory in Multi-core Systems

Abstract

In modern multi-core system, memory is shared among more and more concurrently running threads. Therefore, memory contention and interference is more and more seriously which induces performance degradation unevenly, unfairness resource sharing and priority inversion even starvation. In this paper, we first analyze the problems induced by contention and interference in detail, and then, propose pseudo share framework which brings shared memory to exclusive in multi-core system. The pseudo share framework contains three steps: 1) Partition threads and memory into thread and memory groups respectively, each thread group runs on one core occupying one memory group, 2) Analyze the performance influence after memory shared for each thread, 3) According to performance influence of parallel running threads, allocate memory bandwidth for each thread. We implement pseudo share in 4-core and 8-core platforms. Experimental results show pseudo share optimizes both problems of performance degradation differently and unfairness resource sharing in both 4-core and 8-core. Moreover, pseudo share solves starvation and reduces 5.3% power on average.