BarTLB: Barren Page Resistant TLB for Managed Runtime Environments

This thesis observes that many translation look-aside bu_er (TLB) misses in managed runtime language workloads originate from barren pages. That is, pages that contain mostly dead objects sprinkled with only a few live objects. The main contribution of this work is that it characterizes the barren page phenomenon. This work also proposes (1) a low-cost barren page identi_cation technique, and (2) two simple, low-cost techniques for improving TLB performance: (a) The Barren Page First (BPF) replacement policy extends an existing TLB replacement policy to prefer barren pages on evictions. (b) Selective In-Cache Translation Caching (SICTC) avoids installing barren pages in the TLB by augmenting one way of a virtually-indexed, physically-tagged L1 data cache with virtual tags. Experiments _nd that for those Dacapo and SPECJBB2005 workloads thatexhibit barren pages BPF and SICTC improve performance by 4% and 9.2% on average.M.A.S