Allocating SMART cache segments for schedulability

Since they were first introduced in the IBM 360/85 in 1969, cache designs have been optimized for average case performance, which has opened a wide gap between average case performance and the worst case performance that is critical to real-time computing community. The SMART (Strategic Memory Allocation for Real-Time) cache design narrows this gap. This paper focuses on an analytical approach to cache allocation. An overview of the SMART caching strategy is presented, as well as a dynamic programming algorithm which finds an allocation of cache segments to a set of periodic tasks that both minimizes the utilization of the task set and guaranteeing that the task set remains schedulable using rate monotonic scheduling. Results which show SMART caches narrowing the gap between average and worst case performance to less than 10% are then presented.<>