UC Berkeley

Manycore microprocessors are powerful computing engines that are architected to embrace the use of parallelism to extract computational throughput from the continued improvements in the semiconductor manufacturing process. Yet the performance of the software applications running on these microprocessors is highly sensitive to factors such as data layout, data placement, and synchronization. These factors are not usually part of an application domain experts daily concerns, as they look to utilize the powerful compute capabilities of manycore microprocessors for their applications, but failure to carefully address these concerns could mean an order of magnitude of loss in application execution latency and/or throughput. With the proliferation of manycore microprocessors from servers to laptops and portable devices, there is increasing demand for the productive development of computationally efficient business and consumer applications in a wide range of usage scenarios. The sensitivity of execution speed to software architecture and programming techniques can impede the adoption of the manycore microprocessors and slow the momentum of the semiconductor industry.

This thesis discusses how we can empower application domain experts with pattern- oriented application frameworks, which can allow them to effectively utilize the capabilities of highly parallel manycore microprocessors and productively develop efficient parallel software applications. Our pattern-oriented application framework includes an application context for outlining application characteristics, a software architecture for describing the application concurrency exploited in the framework, a reference implementation as a sample design, and a set of extension points for flexible customization.

We studied the process of accelerating applications in the fields of machine learning and computational finance, specifically looking at automatic speech recognition (ASR), financial market value-at-risk estimation (VaR), and financial potential future exposure (PFE). We present a pattern-oriented application framework for ASR, as well as efficient reference implementations of VaR and PFE. For the ASR framework, we demonstrate its construction and two separate deployments, one of which flexibly extends the ASR framework to enable lip-reading in high-noise recognition environments. The framework enabled a Matlab/Java programmer to effectively utilize a manycore microprocessor to achieve a 20x speedup in recognition throughput as compared to a sequential CPU implementation.

Our pattern-oriented application framework provides an approach for crystallizing and transferring the often-tacit knowledge of effective parallel programming techniques while allowing for flexible adaptation to various application usage scenarios. We believe that the pattern-oriented application framework will be an essential tool for the effective utilization of manycore microprocessors for application domain experts.