No abstract

Today's data centers face the issue of balancing electricity use and completion times of their workloads. Rising electricity costs are forcing data center operators to either operate within an electricity budget or to reduce electricity use as much as possible while still maintaining service agreements. Energy-aware resource allocation is one technique a system administrator can employ to address both problems: optimizing the workload completion time (makespan) when given an energy budget, or to minimize energy consumption subject to service guarantees (such as adhering to deadlines). In this paper, we study the problem of energy-aware static resource allocation in an environment where a collection of independent (non-communicating) tasks ("bag-of-tasks") is assigned to a heterogeneous computing system. Computing systems often operate in environments where task execution times vary (e.g., due to cache misses or data dependent execution times). We model these execution times stochastically, using probability density functions. We want our resource allocations to be robust against these variations, where we define energyrobustness as the probability that the energy budget is not violated, and makespan-robustness as the probability a makespan deadline is not violated. We develop and analyze several heuristics for energy-aware resource allocation for both energy-constrained and deadline-constrained problems.

No abstract

With increasing application complexity and improvements in process technology, Chip MultiProcessors (CMPs) with tens to hundreds of cores on a chip are becoming a reality. Networks-on-Chip (NoCs) have emerged as scalable communication fabrics that can support high bandwidths for these massively parallel multicore systems. However, traditional electrical NoC implementations still need to overcome the challenges of high data transfer latencies and large power consumption. On-chip photonic interconnects with high performance-per-watt characteristics have recently been proposed as an alternative to address these challenges for intra-chip communication. In this article, we explore using low-cost photonic interconnects on a chip to enhance traditional electrical NoCs. Our proposed hybrid photonic ring-mesh NoC (METEOR) utilizes a configurable photonic ring waveguide coupled to a traditional 2D electrical mesh NoC. Experimental results indicate a strong motivation to consider the proposed architecture for future CMPs, as it can provide about 5× reduction in power consumption and improved throughput and access latencies, compared to traditional electrical 2D mesh and torus NoC architectures. Compared to other previously proposed hybrid photonic NoC fabrics such as the hybrid photonic torus, Corona, and Firefly, our proposed fabric is also shown to have lower photonic area overhead, power consumption, and energy-delay product, while maintaining competitive throughput and latency.

No abstract