Improving System Performance with Compressed Memory

system architecture, compression, performance evaluation Linux, memory optimization This report summarizes our research on implementing a compressed memory in computer systems. The basic premise is that the throughput for applications whose working set size does not fit in main memory degrades significantly due to an increase in the number of page faults. Hence we propose compressing memory pages that need to be paged out and storing them in memory. This hides the large latencies associated with a disk access, since the page has to be merely uncompressed when a page fault occurs. Our implementation is in the form of a device driver for Linux. We first evaluate a number of compression algorithms for use in the driver for Linux. We then show results with some applications from the SPEC 2000 CPU benchmark suite and a computing kernel. It is seen that speed-ups ranging from 5% to 250% can be obtained, depending on the application behavior.