An efficient runtime power allocation scheme for many-core systems inspired from auction theory

摘要

Design of future many-core chips is experiencing a paradigm shift to the so-called power-budgeting design, due to the widening gap between instantaneous power consumption and the allowed maximum power, referred as the power budget. Critical to these many-core chips is the runtime power allocation mechanism which can help optimizing the overall system performance under a limited power budget constraint. In this paper, the power allocation problem (i.e., maximizing the system performance under a power budget) is modeled by a combinatorial auction. The problem can be transformed to a knapsack problem and the optimal solution reaches a Walrasian equilibrium. To solve the problem efficiently in a decentralized way, a Hierarchal MultiAgent based Power allocation (HiMAP) method is proposed with an optimal bound. In HiMAP, tiles bid for the opportunity to become active based on the chip's total power budget. Upon finishing an auction process, certain tiles will be power gated and/or frequency scaled according to the power allocation decision. Experimental results have confirmed that HiMAP can reduce the execution time by as much as 45% compared to four competing methods. The runtime overhead and cost of HiMAP are also small, which makes it scale well with many-core systems. (C) 2014 Elsevier B.V. All rights reserved.