Lawrence Berkeley National Laboratory

As next-generation experimental and observational instruments for scientific research are being deployed with higher resolutions and faster data capture rates, the fundamental demands of producing high-quality scientific throughput require portability and performance to meet the high productivity goals. Understanding such a workflow's end-to-end performance on HPC systems is formidable work. In this paper, we address this challenge by introducing a Workflow Roofline model, which ties a workflow's end-to-end performance with peak node- and system-performance constraints. We analyze four workflows: LCLS, a time-sensitive workflow that is bound by system external bandwidth; BerkeleyGW, a traditional HPC workflow that is bound by node-local performance; CosmoFlow, an AI workflow that is bound by the CPU preprocessing; and GPTune, an auto tuner that is bound by the data control flow. We demonstrate the ability of our methodology to understand various aspects of performance and performance bottlenecks on workflows and systems and motivate workflow optimizations.