Dynamic object sampling for pretenuring

10 years 6 months ago
Dynamic object sampling for pretenuring
Many state-of-the-art garbage collectors are generational, collecting the young nursery objects more frequently than old objects. These collectors perform well because young objects tend to die at a higher rate than old ones. However, these collectors do not examine object lifetimes with respect to any particular program or allocation site. This paper introduces low-cost object sampling to dynamically determine lifetimes. The sampler marks an object and records its allocation site every n bytes of allocation. The collector then computes per-site nursery survival rates. Sampling degrades total performance by only 3% on average for sample rates of 256 bytes in Jikes RVM, a rate at which overall lifetime accuracy compares well with sampling every object. An adaptive collector can use this information to tune itself. For example, pretenuring decreases nursery collection work by allocating new, but long-lived, objects directly into the mature space. We introduce a dynamic pretenuring mecha...
Maria Jump, Stephen M. Blackburn, Kathryn S. McKin
Added 02 Jul 2010
Updated 02 Jul 2010
Type Conference
Year 2004
Where IWMM
Authors Maria Jump, Stephen M. Blackburn, Kathryn S. McKinley
Comments (0)