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

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.