Cache Persistence Aware Response Time Analysis for Fixed Priority Preemptive Systems
Ref: CISTER-TR-160207 Publication Date: 11 to 13, Apr, 2016
Cache Persistence Aware Response Time Analysis for Fixed Priority Preemptive SystemsRef: CISTER-TR-160207 Publication Date: 11 to 13, Apr, 2016
A task can be preempted by several jobs of a higher priority task during its response time. Assuming the worst-case memory demand for each of these jobs leads to pessimistic worstcase response time (WCRT) estimations. Indeed, there is a high chance that a big portion of the instructions and data associated with the preempting task τj, are still available in the cache when τj releases its next jobs. We call this content “persistent cache blocks” (PCBs). Accounting for PCBs in the memory demand of the preempting task allows to significantly reduce the pessimism on the total memory demand considered by the WCRT analysis. In this work, we propose a refined WCRT analysis for fixed priority preemptive systems considering (i) the effect of PCBs on the memory demand of the preempting task, and (ii) accounting for the number of PCBs that can be evicted by the preempted tasks between two successive job releases of the preempting tasks.
22nd IEEE Real-Time Embedded Technology & Applications Symposium (RTAS 2016), WiP.