A graphics tracing framework for exploring CPU+GPU memory systems

Modern SoCs contain CPU and GPU cores to execute both general purpose and highly-parallel graphics workloads. While the primary use of the GPU is for rendering graphics, the effects of graphics workloads on the overall system have received little attention. The primary reason for this is the lack of efficient tools and simulators for modern graphics applications. In this work, we present GLTraceSim, a new graphics memory tracing and replay framework for studying the memory behavior of graphics workloads and how they interact in heterogeneous CPU/GPU memory systems. GLTraceSim efficiently generates GPU memory access traces and their corresponding, synchronized, CPU render thread memory traces. The resulting traces can then be replayed in both high-level models and detailed full-system simulators. We evaluate GLTraceSim on a range of graphics workloads from browsers to games. Our results show that GLTraceSim can efficiently generate graphics memory traces, and use these traces to study graphics performance in heterogeneous CPU/GPU memory systems. We show that understanding the impact of graphics workloads is essential, as they can cause slowdowns in co-running CPU applications of 26-59%, depending on the memory technology.