Coordinated Management of DVFS and Cache Partitioning under QoS Constraints to Save Energy in Multi-Core Systems

TL;DR

This paper presents a novel QoS-driven resource management algorithm that dynamically adjusts cache partitioning and voltage-frequency settings in multi-core systems to minimize energy consumption while meeting application performance requirements.

Contribution

It introduces the first coordinated approach to dynamically optimize cache and DVFS settings for energy efficiency under QoS constraints in multi-core systems.

Findings

Energy can be reduced by up to 18% in 4-core systems.

Energy savings of up to 14% in 8-core systems.

Potential energy savings of 29% with relaxed QoS targets.

Abstract

Reducing the energy expended to carry out a computational task is important. In this work, we explore the prospects of meeting Quality-of-Service requirements of tasks on a multi-core system while adjusting resources to expend a minimum of energy. This paper considers, for the first time, a QoS-driven coordinated resource management algorithm (RMA) that dynamically adjusts the size of the per-core last-level cache partitions and the per-core voltage-frequency settings to save energy while respecting QoS requirements of every application in multi-programmed workloads run on multi-core systems. It does so by doing configuration-space exploration across the spectrum of LLC partition sizes and Dynamic Voltage Frequency Scaling (DVFS) settings at runtime at negligible overhead. We show that the energy of 4-core and 8-core systems can be reduced by up to 18% and 14%, respectively, compared to a baseline with even distribution of cache resources and a fixed mid-range core voltage-frequency setting. The energy savings can potentially reach 29% if the QoS targets are relaxed to 40% longer execution time.