Isla Vista Heap Sizing: Using Feedback to Avoid Paging

Abstract

Managed runtime environments (MREs) employ garbage collection (GC) for automatic memory management. However, GC induces pressure on the virtual memory (VM) manager, since it may touch pages that are not related to the working set of the application. Paging due to GC can significantly hurt performance, even when the application's working set fits into physical memory. We present a feedback-directed heap resizing mechanism to avoid GC-induced paging, using information from the operating system (OS). We avoid costly GCs when there is physical memory available, and trade off GC for paging when memory is constrained. Our mechanism is simple and uses allocation stall events during GC alone to trigger heap resizing, without user participation or OS kernel modification. Our system enables significant performance improvements when real memory is restricted and similar to, or better performance than, the current state-of-the-art MRE, when memory is unconstrained