Hybrid Instruction Cache Partitioning for Preemptive Real-Time Systems

Cache memories have been historically avoided in real-time systems because of their unpredictable behavior. In addition to the research focused at obtaining the worstcase execution time of cached programs (typically assuming no preemption), some techniques have been presented to deal with the cache interference due to preemptions (extrinsic or inter-task cache interference). These techniques either account for the extrinsic (cache) interference in the schedulability analysis, or annuls it by partitioning the cache. This paper describes a new technique, hybrid partitioning, which is a mixture of the former two. It either provides a task with a private partition or accounts for the extrinsic interference that may arise. The hybrid technique outperforms the original two for any workload or hardware configuration. In conclusion, it represents a powerful yet general framework for dealing with extrinsic cache interference. 1 Introduction Cache memories are becoming inevitable as a mean to p..