Comparing direct-to-cache transfer policies to TCP/IP and M-VIA during receive operations in MPI environments

Abstract

The main contributors to message delivery latency in message passing environments are the copying operations needed to transfer and bind a received message to the consuming process/thread. To reduce this copying overhead, we introduce architectural extensions comprising a specialized network cache and instructions. In this work, we study the possible overhead and cache pollution introduced through the operating system and the communications stack as exemplified by Linux, TCP/IP and MVIA. We introduce this overhead in our simulation environment and study its effects on our proposed extensions. Ultimately, we have been able to compare the performance achieved by an application running on a system incorporating our extensions with the performance of the same application running on a standard system. The results show that our proposed approach can improve the performance of MPI applications by 10% to 20%. © Springer-Verlag Berlin Heidelberg 2007.