Summary: Building a Real-Time Multi-GPU Platform: Robust Real-Time Interrupt
Handling Despite Closed-Source Drivers
Glenn A. Elliott and James H. Anderson
Department of Computer Science, University of North Carolina at Chapel Hill
Abstract--Architectures in which multicore chips are
augmented with graphics processing units (GPUs) have
great potential in many domains in which computationally
intensive real-time workloads must be supported. How-
ever, unlike standard CPUs, GPUs are treated as I/O
devices and require the use of interrupts to facilitate
communication with CPUs. Given their disruptive nature,
interrupts must be dealt with carefully in real-time systems.
With GPU-driven interrupts, such disruptiveness is further
compounded by the closed-source nature of GPU drivers.
In this paper, such problems are considered and a solution
is presented in the form of an extension to LITMUSRT
called klitirqd. The design of klitirqd targets systems with
multiple CPUs and GPUs. In such settings, interrupt-
related issues arise that have not been previously addressed.