Barrelfish is a research project being jointly undertaken by ETH Zurich and Microsoft Research Cambridge to develop an operating system that can scale across many processor cores.The issue with current operating systems is that they only scale to a few high speed cores because the fundamental design over the last thirty years have focused on optimising single threads of execution over mutiple processors using common shared memory structures.The CPU manufacturers have been focused on increasing the processor performance through clock-speed, cache-memory and pipelining enhancements. This was never going to last because getting the processor die smaller was getting more challenging to put more transistors on the chip and also getting rid of the heat generated by the semiconductors was reaching practical limits.The solution has been to step back on clock speed and put more processor cores on the die to still improve the performance of the CPU overall which now creates a challenge for developers and operating system designers alike.The ETH Zurich and Microsoft teams are working on challenging the design of the fundamental design of operating system which relies on too many central structures that are shared by all the cores creating coherence and consistency problems. Their model proposes using replicated state and using message based models to turn the cores into isolated islands similar to the design of GUI based systems and large scale Event Driven Architectures. The messaging architecture in the proposal in fundamentally messaging over RPC (Remote Procedure Calls) and it will be interesting to see how this develops.The fruits of this work on Barrelfish make take some time to develop into production ready code but this should go some way to address the problem of being able to use the many cores in future processors.This work is being published at Proceedings of the 22nd ACM Symposium on OS Principles in October 2009.See http://www.barrelfish.org for more details.
