Cache locking vs. partitioning for real-time computing on integrated CPU-GPU processors

Heterogeneous multicore processors with integrated CPU and GPU cores on the same chip pose new challenges and opportunities for time-predictable resources sharing, which is crucial for hard real-time and safety-critical systems. The shared last-level cache (LLC) can result in a large number of interferences between CPU and GPU (Graphic Processing Units) LLC accesses with diverse patterns and characteristics, thus impacting the performance and time predictability of both CPUs and GPUs. In this paper, we explore cache partitioning, locking and a combination of them to make the LLC time-predictable for integrated CPU-GPUs while achieving high performance. By evaluating these LLC management approaches, we are able to provide real-time systems developers recommendations on the most effective time-predictable LLC designs for heterogeneous CPU-GPU multicore processors.

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