Real-Time CORBA performance on Linux-RT_PREEMPT

Title

Real-Time CORBA performance on Linux-RT_PREEMPT

Author

Manuel Traut

Author Information

Linutronix, Germany

Abstract

Automation technology lacks an established platform independent, high-level, object oriented real-time capable communication standard, which is based on standard Ethernet hardware and drivers. ACE/TAO is an Open Source implementation of the OMG Real-Time CORBA Specification and might fill this gap. It is designed platform independent, implemented in C++ and provides a standardized communication framework. Real-Time CORBA is already used in industrial environments, e.g. aircraft, naval equipment and others. This paper explains the basics of the ACE/TAO framework and its usage in industrial communication. On the basis of a real-world example - transmission of an 1 KiB data frame - two communication methods are evaluated: the RT-CORBA Remote Procedure Call and the TAO Real-Time Event-Channel. The performance measurement methods are explained in detail. Measurement results under various system loads and a comparison of ACE/TAO on top of a vanilla Linux kernel and a RT_PREEMPT enabled Linux kernel provide a meaningful insight in the capabilities of RT-CORBA. Finally, the paper provides an analysis of functionality which needs to be improved in the operating system to provide real deterministic communication through a standardized framework.

Keywords

Middleware, Automation, RT_PREEMPT, CORBA