Integrated Analysis of Cache Related Preemption Delays and Cache Persistence Reload Overheads

Abstract

Schedulability analysis for tasks running on micro-processors with cache memory is incomplete without a treatment of Cache Related Preemption Delays (CRPD) and CachePersistence Reload Overheads (CPRO). State-of-theart analysescompute CRPD and CPRO independently, which might result incounting the same overhead more than once.In this paper, we analyze the pessimism associated with theindependent calculation of CRPD and CPRO in comparison toan integrated approach. We answer two main questions: (1) Isit beneﬕcial to integrate the calculation of CRPD and CPRO?(2) When and to what extent can we gain in terms of schedu-lability by integrating the calculation of CRPD and CPRO? Toachieve this, we (i) identify situations where considering CRPDand CPRO separately might result in overestimating the totalmemory overhead suffered by tasks, (ii) derive new analyses thatintegrate the calculation of CRPD and CPRO; and (iii) perform athorough experimental evaluation using benchmarks to comparethe performance of the integrated analysis against the separatecalculation of CRPD and CPRO. Abstract-Schedulability analysis for tasks running on microprocessors with cache memory is incomplete without a treatment of Cache Related Preemption Delays (CRPD) and Cache Persistence Reload Overheads (CPRO). State-of-the-art analyses compute CRPD and CPRO independently, which might result in counting the same overhead more than once.In this paper, we analyze the pessimism associated with the independent calculation of CRPD and CPRO in comparison to an integrated approach. We answer two main questions: (1) Is it beneficial to integrate the calculation of CRPD and CPRO? (2) When and to what extent can we gain in terms of schedulability by integrating the calculation of CRPD and CPRO? To achieve this, we (i) identify situations where considering CRPD and CPRO separately might result in overestimating the total memory overhead suffered by tasks, (ii) derive new analyses that integrate the calculation of CRPD and CPRO; and (iii) perform a thorough experimental evaluation using benchmarks to compare the performance of the integrated analysis against the separate calculation of CRPD and CPRO.

Cache-aware Schedulability Analysis of PREM Compliant Tasks

“…This is in-line with the memory access demand to WCET ratio of most benchmarks from the Mälardalen benchmark suite[19],[20].…”

On the Trade-offs between Generalization and Specialization in Real-Time Systems

“…• Further improvements to the analysis of static-priority preemptive systems with CRPD can be achieved by considering cache lines that are able to persist in the cache between the execution of jobs of the same task, without being evicted by interleaving execution. This analysis focuses on Cache Persistence Reload Overheads (CPRO) [58], and dominates equivalent analyses that only consider CRPD.…”

Tightening the CRPD bound for multilevel non-inclusive caches

“…Building on the analysis in [4], Markovic et al [21] have recently proposed an analysis that dominate all the existing approaches for CRPD calculation for single-level cache. Rashid et al [22][23][24] have also presented several approaches that use the notion of cache persistence along with CRPD to improve the bounds on preemption related cache overheads for single-level caches.…”