Assist Thread Compilation for Multi-threaded Processors

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

The next generation of computers will be multi-threaded, allowing the simultaneous execution of several programs. Most computer workloads are difficult to recast into multi-threaded form, under-utilizing multi-threading capabilities. This research studies a new approach to program translation: Assist Threads. An assist thread is a specialized version of an application program that, when run as an independent thread, assists (and optimizes) the application. Roles for assist threads include program profiling, monitoring, pre-execution, and memory management. Experiments show that assist threads can effectively implement garbage collection. An assist thread mimics an application's execution, tracking memory accesses and recycling unused memory as it is recognized. The main application thread ignores memory management concerns, becoming simpler, faster and more reliable. Other varieties of assist threads execute slightly in advance of an application program, precomputing and preloading needed data values. This research makes both theoretical and practical contributions to compiler technology. It explores how to generate the computations necessary to implement assist threads. It also experiments with a variety of assist threads, evaluating their effectiveness and efficiency. In summary, this research opens new avenues of application for multi-threaded processors, making them more effective in supporting the needs of a wide variety of computer users.