A Simulation-Based Study of TLB Performance

This paper presents the results of a simulation-based study of various translation lookaside buffer (TLB) architectures, in the context of a modern VLSI RISC processor. The simulators used address traces, generated by instrumented versions of the SPECmarks and several other programs running on a DECstation 5000. The performance of two-level TLBs and fullyassociative TLBs were investigated. The amount of memory mapped was found to be the dominant factor in TLB performance. Small first-level FIFO instruction TLBs can be effective in two level TLB configurations. For some applications, the cycles-per-instruction (CPI) loss due to TLB misses can be reduced from as much as 5 CPI to negligible levels with typical TLB parameters through the use of variable-sized pages. This research report is a preprint of a paper to appear in the Proceedings of the 19th International Symposium on Computer Architecture. Copyright Ó 1992 Digital Equipment Corporation A Simulation-Based Study of TLB Performa..