The Design and Implementation of Multiprocessor Support for an Industrial Operating System Kernel

The ongoing transition from uniprocessor to multi-core computers requires support from the operating system kernel. Although many general-purpose multiprocessor operating systems exist, there is a large number of specialized operating systems which require porting in order to work on multiprocessors. In this paper we describe the multiprocessor port of a cluster operating system kernel from a producer of industrial systems. Our initial implementation uses a giant locking scheme that serializes kernel execution. We also employed a method in which CPU-local variables are placed in a special section mapped to per-CPU physical memory pages. The giant lock and CPU-local section allowed us to implement an initial working version with only minor changes to the original code, although the giant lock and kernel-bound applications limit the performance of our multiprocessor port. Finally, we also discuss experiences from the implementation. keywords: Multiprocessor, operating system, kernel, cluster, porting, implementation