Control flow based cost analysis for P4

• Main Authors: Lukács Dániel, Pongrácz Gergely, Tejfel Máté
• Format: Article
• Language: English
• Published: De Gruyter 2020-12-01
• Series: Open Computer Science
• Subjects: data plane; control flow graph; static profiling; refinement; soft real-time
• Online Access: https://doi.org/10.1515/comp-2020-0131

The networking industry is currently undergoing a steady trend of softwarization. Yet, network engineers suffer from the lack of software development tools that support programming of new protocols. We are creating a cost analysis tool for the P4 programming language, that automatically verifies whether the developed program meets soft deadline requirements imposed by the network. In this paper, we present an approach to estimate the average execution time of P4 program based on control flow graphs. Our approach takes into consideration that many of the parts of P4 are implementation-defined: required information can be added in through incremental refinement, while missing information is handled by falling back to less precise defaults. We illustrate application of this approach to a P4 protocol in two case studies: we use it to examine the effect of a compiler optimization in the deparse stage, and to show how it enables cost modelling complex lookup table implementations. Finally, we assess future research tasks to be completed before the tool is ready for real-world usage.