Solving the shared-cache problem

25th February 2014

Nat Bowers

0 0

Now allowing users to prioritise simultaneous access of guest operating systems to shared resources like shared caches or the main memory itself, Real-Time Systems release an updated version of Hypervisor. This approach avoids lower priority operating systems influencing an RTOS using the same the last level cache.

This software is particularly useful for products in the industrial, medical or transportation markets where many customers rely on a real-time operating system for time or mission critical functions while using a different operating system for other tasks, such as running a HMI. Since the solution does not depend on a host OS, operating systems can start in any sequence, reboot independently and never harm each other.

RTS Hypervisor has always offered strict separation of operating systems while preserving hard real-time determinism. Until now, virtualisation technology has been used to virtualise and monitor unmodified, non-real-time operating systems like Microsoft Windows. Hypervisor goes one step further: it can now detect excessive memory usage of a non-real-time Operating System, which due to shared utilisation of cache or simultaneous access to the systems main memory could cause jitter in a high priority real-time operating system running in parallel. Real-Time Systems claim that this is an industry first.

Hypervisor features a finely adjustable throttle which can now limit the amount of memory throughput available to a virtualised operating system in order to avoid negative impact on an RTOS due to potential cache misses or an occupied data bus. This throttle only takes effect if a user configurable threshold is about to be reached. Tests have revealed that this greatly reduces jitter and therefore improves determinism significantly. Customers with very demanding requirements regarding latencies and determinism can now finally run multiple operating systems on the same hardware while still providing the hard real-time capability expected of their system.

The RTS Hypervisor software enables customers to partition an Intel x86 multi core platform into virtually independent computers running e.g. a Microsoft operating system as a user interface and separate real-time operating systems in parallel for real-time tasks on the same hardware. By consolidating the hardware, users can greatly reduce cost and power consumption while increasing reliability.