Out of Hand for Hardware? Within Reach for Software!

Abstract

Events that take 10s to 100s of ns like cache misses increasingly cause CPU stalls. However, hiding the latency of these events is challenging: hardware mechanisms suffer from the lack of flexibility, whereas prior software mechanisms fall short due to large overhead and limited event visibility. In this paper, we argue that with a combination of two emerging techniques - light-weight coroutines and sample-based profiling, hiding these events in software is within reach.