Reducing Memory Interference Latency of Safety-Critical Applications via Memory Request Throttling and Linux Cgroup

摘要

With the advent of high-performance multicore processors that operate under a limited power budget, dedicated low-end microprocessors with different levels of criticality are rapidly consolidated into a mixed-criticality system. One of the major challenges in designing such a mixed-criticality system is to tightly control the amount of resource contention for a critical application by effectively limiting its performance interference incurred due to sharing resources with non-critical tasks. In this paper, we propose application-aware dynamic memory request throttling to reduce the memory interference latency of a critical application in a dual criticality system. Our approach carefully differentiates critical task instances from normal task instances and groups them into the critical and normal cgroup, respectively. It then predicts the occurrence of excessive memory contention under critical task execution and then throttles memory requests generated by the normal cgroup via the CPUFreq governor when necessary. We have implemented the approach on the NVIDIA Jetson TX2 with Linux kernel 4.4.38. Experimental results show that the proposed approach reduces the end-to-end latency of a critical application up to 9.49% while incurring only negligible overhead.