UPR: deadlock-free dynamic network reconfiguration by exploiting channel dependency graph compatibility

Abstract

Deadlock-free dynamic network reconfiguration process is usually studied from the routing algorithm restrictions and resource reservation perspective. The dynamic nature yielded by the transition process from one routing function to another is often managed by restricting resource usage in a static predefined manner, which often limits the supported routing algorithms and/or inactive link patterns, or either requires additional resources such as virtual channels. Exploiting compatibility between routing functions by exploring their associated Channel Dependency Graphs (CDG) can take a great benefit from the dynamic nature of the reconfiguration process. In this paper, we propose a new dynamic reconfiguration process called Upstream Progressive Reconfiguration (UPR). Our algorithm progressively performs dependency addition/removal in a per channel basis relying on the information provided by the CDG while the reconfiguration process takes place. This gives us the opportunity to foresee compatible scenarios where both routing functions coexist, reducing the amount of resource drainage as well as packet injection halting.