OCL-BodyScan: A Case Study for Application-centric Programming of Many-Core Processors

Application development for many-core processors is predominately hardware-centric: programmers design, implement, and optimize applications for a pre-chosen target platform. While this approach may deliver very good performance, it lacks portability, being inefficient for applications that aim to use multiple architectures or large-scale parallel platforms with heterogeneous many-core nodes. In this work, we focus on application portability. Therefore, we propose an application-centric approach for developing parallel workloads for many-cores, and we make use of OpenCL to preserve portability until the very last optimization stages. We validate our application-centric approach using 3D body scan, a data intensive application with soft real-time constraints. Thus, we design and implement OCL-body scan (the portable OpenCL-based version of 3D Body scan), and we evaluate its performance on three families of platforms - general purpose multi-cores, graphical processing units, and the Cell/B.E.. Our experiments show that our application-centric strategy enables portability and leads to good performance results. Additionally, typical platform-specific optimizations can be applied in the final implementation stages, leading to performance results similar to those obtained using the native tool-chains.