Preliminary comparison between the single-threaded and multi-threaded RHODOS microkernel

RHODOS is a distributed operating system based on the client-server model and a microkernel paradigm. It is a research tool designed to be capable of implementing and evaluating different mechanisms and policies that are proposed by researchers. To maintain suitability for this task, the RHODOS microkernel has recently been upgraded from single to multi-threaded operation. However, this upgrading has resulted in a significant number of changes to the operation of some system calls and interrupt handlers. This paper compares the two versions of the RHODOS microkernel, and quantifies the changes that have been made with performance timings. This work is very important, as it permits researchers to understand the characteristics and performance limitations of the user and kernel processes they create.