Achieving High Performance Network and Disk I/O with the Memory Xpansion Technology

The Memory Xpansion Technology (MXT)IS o new memory subsystem built for compressing main memory contents. MXT effectively doubles the physically available memory transparently to the CPU, input/output (I/O) devices, and application software. Although the memory content is in compressed form whenever possible, when the memory is accessed, the data is first uncompressed and then served to various components of the system such as the CPU and I/O devices. This prohibits the system from accessing data in the compressed form. In this paper, we present (I mechanism which makes it possible to access the memory content in compressed form. Then, we show how the proposed mechanism can be used for Compressed I/O (CIO) (i.e., performing I/O operations with compressed form of data). In particular, we show that CIO can be integrated into the file system and networking subsystem. We show how MXT can be used on-the-fly and transparently for storing compressed data on the disk and transferring compressed data across the network. With respect to disk I/O, we show that our scheme can reduce the disk space requirement of the system and reduce the cost of accessing data stored on a disk. By using the compressed form of data for data transfers, we show that the observed bandwidth increases and even surpasses the maximum physical network bandwidth depending on the compressibility of data. With a typical case of 2:l compression ratio, UDP transfer over Gigabit Ethernet demonstrates 71% improvement in network bandwidth. Our proposed scheme promises design of high performance and scalable computing systems with low cost. To the best of our knowledge, this is the first integrated solution for taking advantage of MXT technology for high performance network and I/O.