Emerald: Graphics Modeling for SoC Systems

Mobile systems-on-chips (SoCs) have become ubiquitous computing platforms, and, in recent years, they have become increasingly heterogeneous and complex. A typical SoC includes CPUs, graphics processor units (GPUs), image processors, video encoders/decoders, AI engines, digital signal processors (DSPs) and 2D engines among others [33], [70], [71]. One of the most significant SoC units in terms of both off-chip memory bandwidth and SoC die area is the GPU. In this paper, we present Emerald, a simulator that builds on existing tools to provide a unified model for graphics and GPGPU applications. Emerald enables OpenGL (v4.5) and OpenGL ES (v3.2) shaders to run on GPGPU-Sim's timing model and is integrated with gem5 and Android to simulate full SoCs. Emerald thus provides a platform for studying system-level SoC interactions while including the impact of graphics. We present two case studies using Emerald. First, we use Emerald's full-system mode to highlight the importance of system-wide interactions by studying and analyzing memory organization and scheduling schemes for SoC systems. Second, we use Emerald's standalone mode to evaluate a novel mechanism for balancing the graphics shading work assigned to each GPU core.