Intra-process Caching and Reuse of Threads

Abstract

Creating and destroying threads on modern Linux systems incurs high latency, absent concurrency, and fails to scale as we increase concurrency. To address this concern we introduce a process-local cache of idle threads. Specifically, instead of destroying a thread when it terminates, we cache and then recycle that thread in the context of subsequent thread creation requests. This approach shows significant promise in various applications and benchmarks that create and destroy threads rapidly and illustrates the need for and potential benefits of improved concurrency infrastructure. With caching, the cost of creating a new thread drops by almost an order of magnitude. As our experiments demonstrate, this results in significant performance improvements for multiple applications that aggressively create and destroy numerous threads.