Generation and analysis of very long address traces

Abstract

Existing methods of generating and analyzing traces suffer from a variety of limitations including complexity, inaccuracy, short length, inflexibility, or applicability only to CISC machines. We use a trace generation mechanism based on link-time code modification which is simple to use, generates accurate long traces of multi-user programs, runs on a RISC machine, and can be flexibly controlled. On-the-fly analysis of the traces allows us to get accurate performance data for large second-level caches. We compare the performance of systems with 512K to 16M second-level caches, and show that for today's large programs, second-level caches of more than 4MB may be unnecessary. We also show that set associativity in second-level caches of more than 1MB does not significantly improve system performance. In addition, our experiments also provide insights into first-level and second-level cache line size.