%0 Journal Article
%T Towards Self-Adaptive KPN Applications on NoC-Based MPSoCs
%A Onur Derin
%A Prasanth Kuncheerath Ramankutty
%A Paolo Meloni
%A Emanuele Cannella
%J Advances in Software Engineering
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/172674
%X Self-adaptivity is the ability of a system to adapt itself dynamically to internal and external changes. Such a capability helps systems to meet the performance and quality goals, while judiciously using available resources. In this paper, we propose a framework to implement application level self-adaptation capabilities in KPN applications running on NoC-based MPSoCs. The monitor-controller-adapter mechanism is used at the application level. The monitor measures various parameters to check whether the system meets the assigned goals. The controller takes decisions to steer the system towards the goal, which are applied by the adapters. The proposed framework requires minimal modifications to the application code and offers ease of integration. It incorporates a generic adaptation controller based on fuzzy logic. We present the MJPEG encoder as a case study to demonstrate the effectiveness of the approach. Our results show that even if the parameters of the fuzzy controller are not tuned optimally, the adaptation convergence is achieved within reasonable time and error limits. Moreover, the incurred steady-state overhead due to the framework is 4% for average frame-rate, 3.5% for average bit-rate, and 0.5% for additional control data introduced in the network. 1. Introduction Recent trends in microprocessor design have witnessed a paradigm shift from single core architectures towards Multiprocessor-System-on-Chips (MPSoCs) due to unsustainable increases in power dissipation while running a single processor at very high frequencies. As the number of cores in the system increases, on-chip communication becomes a bottleneck. To address the scalability issues of MPSoCs, Networks-on-chips (NoCs) [1] have emerged as a new communication paradigm. However, even in the case of NoC-based systems, if shared memory access is employed, memory coherence protocols induce an overhead in the communication network rendering the gain from additional cores useless. No Remote Memory Access (NORMA) [2] model addresses this problem by assigning a private local memory for each NoC tile. This solution is especially suited for programming models based on message passing. Embedded systems are often subject to stringent non-functional goals such as high computational performance and dependability, low power consumption, memory usage, and chip area. Satisfying such requirements imposed by the application designer on systems with increasing complexity of the underlying architectures is a fundamental challenge. To deal with this problem, designers often resort to
%U http://www.hindawi.com/journals/ase/2012/172674/