Performance Comparison of VxWorks, Linux, RTAI and Xenomai in a Hard Real-time Application

Abstract

We report on a set of performance measurements executed on VMEbus MVME5500 boards equipped with MPC7455 PowerPC processor, running four different operating systems: Wind River VxWorks, Linux, RTAI, and Xenomai. Some components of RTAI and Xenomai have been ported to the target architecture. Interrupt latency, rescheduling and inter-process communication times are compared in the framework of a sample real-time application. Performance measurements on Gigabit Ethernet network communication have also been carried out on the target boards. To this purpose, we have considered the Linux IP stack and RTnet, an open-source hard real-time network protocol stack for Xenomai and RTAI, which was ported to the considered architecture. Performance measurements show that the tested open-source software is suitable for hard real-time applications

A real-time data transmission method based on Linux for physical experimental readout systems

“…We can increase the DMA block transfer size to compensate the real-time deficiency and schedule uncertainty of Linux OS. Along with multicore processors, Linux with innovative kernel can fulfill this task more surely than some other general or embedded operating system [11]. Then there arises the problem of how to allocate large amounts of data in the Linux environment.…”

“…Commercial off-the-shelf multi-core techniques and a new OS kernel optimized in real-time scheduling make engineers discuss and evaluate Linux solutions for the possibility of replacement of VxWorks, not only in industry, but also in scientific research [10,11]. Linux has been successfully applied to many real-time applications, even some hard real-time controls of scientific instruments [12][13][14].…”

Linux real-time framework for fusion devices

“…RTAI is already being successfully used in some fusion laboratories [5,6] but it was never tested on the multi-core x86 platform. As referred in the previous section a RTOS must guarantee low latency in response to hardware interrupts and a precise scheduling of the real-time tasks.…”

Real-time control architecture using Xenomai for intelligent service robots in USN environments

“…In general, interrupt latency and rescheduling time should be considered for evaluating real-time performance. The performance measurements for the measured delays for VxWorks, Xenomai, RTAI and Linux have been addressed by Barbalace et al [17]. Therefore, measurements were concentrated on the performance for the effect of context switching in terms of the number of tasks running simultaneously for both real-time Linux and standard Linux.…”

“…Xenomai is a real-time development framework that cooperates with the Linux kernel in order to provide a pervasive, interface-agnostic, hard real-time support to user-space applications seamlessly integrated into the GNU/Linux environment. In performance measurements on four different OSs, Barbalace et al demonstrated that open-source software such as RTAI and Xenomai are suitable for hard real-time applications [17]. The open and modular approach that uses Xenomai over the IEEE 1394 real-time device driver has been described and its real-time performance has been evaluated for a mobile robot platform [18].…”