E-WarP: A System-wide Framework for Memory Bandwidth Profiling and Management

The proliferation of multi-core, accelerator-enabled embedded systems has introduced new opportunities to consolidate real-time systems of increasing complexity. But the road to build confidence on the temporal behavior of co-running applications has presented formidable challenges. Most prominently, the main memory subsystem represents a performance bottleneck for both CPUs and accelerators. And industry-viable frameworks for full-system main memory management and performance analysis are past due.

In this paper, we propose our Envelope-aWare Predictive model, or E-WarP for short. E-WarP is a methodology and technological framework to: (1) analyze the memory demand of applications following a profile-driven approach; (2) make realistic predictions on the temporal behavior of workload deployed on CPUs and accelerators; and (3) perform saturation-aware system consolidation. This work aims at providing the technological foundations as well as the theoretical grassroots for truly workload-aware analysis of real-time systems. We provide a full implementation of our techniques on a commercial platform (NXP S32V234) and make two key observations. First, we achieve, on average, a 6% overprediction on the runtime of bandwidth-regulated applications. Second, we experimentally validate that the calculated bounds hold if the main memory subsystem operates below saturation.