CODIE: Continuation-Based Overlapping Data-Transfers with Instruction Execution

In this paper, a runtime system termed CODIE is proposed to execute sequential part of programs efficiently in a many-core architecture. All independent processing elements in a many-core architecture use a shared network and off-chip memory. Therefore, contentions on such resources substantially degrade the system performance. On the CODIE system, when a cache miss occurs, the system first initiates a data transfer operation. Next, the system creates a continuation of executing instructions related to the missing data. The continuation is stored into the buffer, and the instructions not related to the missing data are executed subsequently. In other words, data transfer and instruction executions can be performed simultaneously. In this way, the effect of the overhead of the updating cache entry (increased by memory access contention) is tolerated. The results of evaluation show that the proposed CODIE system realizes a 1.86× speed up of the execution of the sequential write/read program on the M-Core architecture at 36 cores and a 1.97× speed up of the execution of the blacks holes(from PARSEC benchmark suite) on the Cell/BE processor with 6 SPEs.