Generation and analysis of very long address traces

Existing methods of generating and analyzing traces suffer from a variety of limitations, including complexity, inaccuracy, short length, inflexibility, or applicability only to CISC (complex-instruction-set-computer) machines. The authors use a trace-generation mechanism based on link-time code modification which is simple to use, generates accurate long traces of multiuser programs, runs on a RISC (reduced-instruction-set-computer) machine, and can be flexibly controlled. Accurate performance data for large second-level caches can be obtained by on-the-fly analysis of the traces. A comparison is made of the performance of systems with 512 K to 16 M second-level caches, and it is show that, for today's large programs, second-level caches of more than 4 MB may be unnecessary. It is also shown that set associativity in second-level caches of more than 1 MB does not significantly improve system performance. In addition, the experiments provide insights into first-level and second-level cache line size.<>