The seminal work on the global real-time scheduling of periodic tasks on unrelated multiprocessor platforms is based on a two-step method. First, the workload of each task is distributed over the processors and it is proved that this first step success ensures the existence of a feasible schedule. Then, using this workload assignment as an input, a template schedule construction method is presented. In this work, we review the seminal work and show by using a counterexample that this second step is incomplete. Thus, we propose and prove correct a novel and efficient algorithm to build the template schedule.
Heterogeneous MPSoCs are being used more and more, from cellphones to critical embedded systems. Most of those systems offer heterogeneous sets of identical cores. In this paper, we propose new results on the global scheduling approach. We extend fundamental global scheduling results on unrelated processors to results on unrelated multicore platforms, a more realistic model. Every discussed result is optimal regarding schedulability, and all but one have a polynomial time complexity. We introduce several methods to construct the workload assignment taking advantage of this new model. Thanks to the model, their produced schedule has a limited degree of migrations. The benefits of those methods are demonstrated using simulation. We also discuss the practical limitations of the global scheduling approach on unrelated platforms and argue that it is still worth investigating considering modern MPSoCs. CCS CONCEPTS • Computer systems organization → Real-time systems; Multicore architectures.
In this work, we consider hard real-time applications scheduled upon heterogeneous multiprocessor platforms. The originality of this study is to consider multi-mode real-time applications (software aspects) and reconfigurable-heterogeneous hardware platforms (composed of CPUs, GPUs, FPGAs. . . ). Our approach is based on a multi-mode protocol, for mode-dependent tasks upon reconfigurable hardware. The goal is to handle predictable switches between different task sets and different hardware settings. The novelty here is the dynamic hardware and software reconfigurability. First, we propose a formal model of the applications and reconfigurable hardware platforms. We then propose and prove correct a mode change protocol. We propose in particular a validity test for the verification of the timing constraints of the application -including the time allowed to complete a mode change. We also perform a complete evaluation. We study the theoretical complexity of the protocol, use a simulation to evaluate the efficiency of our solution, and finally propose a competitive analysis of our protocol to prove that it is 2-competitive. CCS CONCEPTS• Computer systems organization → Real-time systems; Multicore architectures.
Heterogeneous MPSoCs are being used more and more, from cellphones to critical embedded systems. Most of those systems offer heterogeneous sets of identical cores. In this paper, we propose new results on the global scheduling approach. We extend fundamental global scheduling results on unrelated processors to results on unrelated multicore platforms, a more realistic model. We introduce several methods to construct the workload assignment of tasks to cores taking advantage of this new model. Every studied result is optimal regarding schedulability, and all the proposed methods but one have a polynomial time complexity. Thanks to the model, the produced schedules have a limited degree of migrations. The benefits of the methods are demonstrated and compared using synthetic tasks sets. Practical limitations of the global scheduling approach on unrelated platforms are discussed, but we argue that it is still worth investigating considering modern MPSoCs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.