LTTng‐HSA: Bringing LTTng tracing to HSA‐based GPU runtimes

Abstract

SummaryIn this paper, we propose LTTng‐HSA, a set of tools that allow for the collection of a single, unified software graphics processing unit (GPU) trace in ROCr, a Heterogeneous System Architecture (HSA)‐based API and runtime. HSA is a cross‐vendor standard facilitating the programming of heterogeneous systems that include CPUs, GPUs, and possibly other types of devices. Our open‐source solution is generic and easily adaptable to diverse GPU runtimes or APIs. Using Linux Trace Toolkit Next Generation (LTTng), a highly efficient Linux tracer, it collects different types of events over multiple executions of an application and aims to gather all the data into a single trace, offering an easy way to generate GPU‐related traces. Our instrumentation is achieved simply by preloading libraries, without recompiling the target application, which makes it flexible and easy to use. The resulting traces, which include API call stack information, GPU hardware metrics, command queue, and compute kernel profiling, are well adapted for postprocessing and further analysis. Our solution also includes tracing data from the Linux kernel and proposes views for Trace Compass, an interactive trace visualizer.