Real-Time High-Performance Computing for Embedded Control Systems

• DIRECTORS: Leonidas Kosmidis, Carlos Fernando Nicolás Ramírez y Francisco Javier Cazorla Almeida
• UNIVERSITY: UPV/EHU

ABSTRACT

The real-time control systems industry is moving towards the consolidation of multiple computing systems into fewer and more powerful ones, aiming for a reduction in size, weight, and power. The increasing demand for higher performance in other critical domains like autonomous driving has led the industry to recently include embedded GPUs for the implementation of advanced functionalities. The highly parallel architecture of GPUs could also be leveraged in the control systems industry to develop more advanced, energy-efficient, and scalable control systems. However, the closed-source and non-deterministic nature of GPUs complicates the resource provisioning analysis required for the implementation of critical real-time systems. On the other hand, there is no indication of the integration of GPUs in the traditional development cycle of control systems, which is oriented to the use of a model-based design approach. Recently, some model-based design tools vendors have extended their development frameworks with GPU code generation capabilities targeting hybrid computing platforms, so that the model-based design environment now enables the concurrent analysis of more complex and diverse functions by simulation and automating the deployment to the final target. However, there is no indication whether these tools are well-suited for the design and development of time-sensitive systems.
Motivated by these challenges, in this thesis, we contribute to the state of the art of real-time control systems towards the adoption of embedded GPUs by providing tools to facilitate the resource provisioning analysis and the integration in the model-based design development cycle. First, we present a methodology and an automated tool to extract the properties of GPU memory allocators. This tool allows the computation of the real amount of memory used by GPU applications, facilitating a correct resource provisioning analysis. Then, we present a library which allows the characterization of the use of dynamic memory in GPU applications. We use this library to characterize GPU benchmarks and we identify memory allocation patterns that could be modified to improve performance and memory consumption when targeting embedded GPUs. Based on these results, we present a tool to optimize the use of dynamic memory in legacy GPU applications executed on embedded platforms. This tool allows us to minimize the memory consumption and memory management overhead of GPU applications without rewriting them. Afterwards, we analyze the timing of control algorithms executed in embedded GPUs and we identify techniques to achieve an acceptable real-time behavior. Finally, we evaluate model-based design tools in terms of integration with GPU hardware and GPU code generation, and we propose improvements for the model-based generated GPU code. Then, we present a source-to-source transformation tool to automatically apply the proposed improvements.