Scheduling Real-Time Template-Tasks on Manycores Heterogeneous Platforms

Recent broadband cellular network technology requires to guarantee respect for timing constraints to ensure the required Quality of Service (QoS) and improve user experience. The Base Transceiver Station (BTS) must activate and process a large set of real-time tasks, representing user requests, on a heterogeneous many-core platform. Each request is an instance of a heterogeneous parallel and conditional Directed Acyclic Graph (HPC-DAG) task that must complete no later than a predefined deadline. Classical real-time scheduling and schedulability analysis approaches can not be directly applicable to such systems because task activation profiles can drastically change based on end-user requests. Additionally, classical schedulability analysis might exhibit scalability issues in supporting a large number of task instances on hundreds of cores. This work addresses the problem of allocating and scheduling a set of real-time tasks to a heterogeneous platform composed of hundreds of cores. We present efficient scheduling and allocation approaches to guarantee that all timing constraints are respected within a single scheduling frame. We propose novel schedulability tests, allowing us to explore numerous possible design choices for user requests. The performance of the proposed approaches is studied through a large set of synthetic experiments.