The pauseless GC algorithm

Modern transactional response-time sensitive applications have run into practical limits on the size of garbage collected heaps. The heap can only grow until GC pauses exceed the responsetime limits. Sustainable, scalable concurrent collection has become a feature worth paying for. Azul Systems has built a custom system (CPU, chip, board, and OS) specifically to run garbage collected virtual machines. The custom CPU includes a read barrier instruction. The read barrier enables a highly concurrent (no stop-the-world phases), parallel and compacting GC algorithm. The Pauseless algorithm is designed for uninterrupted application execution and consistent mutator throughput in every GC phase. Beyond the basic requirement of collecting faster than the allocation rate, the Pauseless collector is never in a “rush” to complete any GC phase. No phase places an undue burden on the mutators nor do phases race to complete before the mutators produce more work. Portions of the Pauseless algorit...

• Type: Conference
• Year: 2005
• Where: VEE
• Authors: Cliff Click, Gil Tene, Michael Wolf
• Keywords: GC Algorithm, GC Phase, Read Barriers, VEE 2005, Virtualization