A study of large object spades

This paper examines the design space for copying garbage collectors (GCs) i n which "large objects" are managed in a separate, non-copy-collected space . We focus on two main issues: 1. how to set the policy for classifying objects as "large" 2. how to manage the large object space We explore these issues experimentally using the Oscar GC testbed. In parti cular, we vary the threshold size of large objects and also whether the obj ects may contain pointers. Furthermore, we compare the performance of tread mill collection to that of mark-and-sweep collection for managing the large object space. We find that for some heaps there is a minimum cutoff size below which addi ng objects to the large object space does not result in a performance impro vement, while for others no such cutoff exists. In general, including point er-containing objects in the large object space seems beneficial. Finally, the exact method used to collect the large object space does not significan tly influence overall performance.