Dynamic Java Threads on the JAMAICA Single-Chip Multiprocessor

The JAMAICA system combines a multithreaded single-chip multiprocessor with a dynamic thread distribution mechanism, to provide hardware support for finegrained Java threads. This paper gives an overview of the threading mechanism, and investigates the granularity of parallelism which can be exploited in this way. Simulations demonstrate that the current system gives good performance with a wide range of granularities, down to as low as 1000 cycles. Experiments with two real Java applications, exhibiting coarse and medium-grained parallelism, confirm that the technique can also be used in place of more traditional load balancing methods.