No-Break Dynamic Defragmentation of Reconfigurable Devices

TL;DR

This paper introduces a dynamic defragmentation method for reconfigurable devices that improves contiguous free space by about 50% during runtime, reducing rejections and handling FPGA inhomogeneities.

Contribution

It presents a novel runtime defragmentation approach using tabu search, addressing communication and inhomogeneity challenges in FPGA layouts.

Findings

Improves module layout quality by roughly 50%.

Reduces module rejection rates.

Handles communication needs and FPGA inhomogeneities effectively.

Abstract

We propose a new method for defragmenting the module layout of a reconfigurable device, enabled by a novel approach for dealing with communication needs between relocated modules and with inhomogeneities found in commonly used FPGAs. Our method is based on dynamic relocation of module positions during runtime, with only very little reconfiguration overhead; the objective is to maximize the length of contiguous free space that is available for new modules. We describe a number of algorithmic aspects of good defragmentation, and present an optimization method based on tabu search. Experimental results indicate that we can improve the quality of module layout by roughly 50 % over static layout. Among other benefits, this improvement avoids unnecessary rejections of modules