English

Bringing Inter-Thread Cache Benefits to Federated Scheduling -- Extended Results & Technical Report

Distributed, Parallel, and Cluster Computing 2020-03-02 v1 Operating Systems

Abstract

Multiprocessor scheduling of hard real-time tasks modeled by directed acyclic graphs (DAGs) exploits the inherent parallelism presented by the model. For DAG tasks, a node represents a request to execute an object on one of the available processors. In one DAG task, there may be multiple execution requests for one object, each represented by a distinct node. These distinct execution requests offer an opportunity to reduce their combined cache overhead through coordinated scheduling of objects as threads within a parallel task. The goal of this work is to realize this opportunity by incorporating the cache-aware BUNDLE-scheduling algorithm into federated scheduling of sporadic DAG task sets. This is the first work to incorporate instruction cache sharing into federated scheduling. The result is a modification of the DAG model named the DAG with objects and threads (DAG-OT). Under the DAG-OT model, descriptions of nodes explicitly include their underlying executable object and number of threads. When possible, nodes assigned the same executable object are collapsed into a single node; joining their threads when BUNDLE-scheduled. Compared to the DAG model, the DAG-OT model with cache-aware scheduling reduces the number of cores allocated to individual tasks by approximately 20 percent in the synthetic evaluation and up to 50 percent on a novel parallel computing platform implementation. By reducing the number of allocated cores, the DAG-OT model is able to schedule a subset of previously infeasible task sets.

Keywords

Cite

@article{arxiv.2002.12516,
  title  = {Bringing Inter-Thread Cache Benefits to Federated Scheduling -- Extended Results & Technical Report},
  author = {Corey Tessler and Venkata P. Modekurthy and Nathan Fisher and Abusayeed Saifullah},
  journal= {arXiv preprint arXiv:2002.12516},
  year   = {2020}
}
R2 v1 2026-06-23T13:57:07.328Z