Real-time Operating System ARTs-OS Performance Evaluation And Test

A system does not only need to have a high throughput but all its components need to be reliable and predictable. A generic real-time system is composed of three levels: the hardware, the operating system and the application. At application level, the software relies on the operating system. Several methods can be used to verify whether or not an application can meet deadline requirements. However this type of analysis is based on the assumption that the operating system is a real-time system. The underlying hardware needs to be deterministic. Some technology of hardware is base on the statistics, which is to improve the average performance, so this may introduce non real-time responses. RTOS manage the hardware resources, and provide API and development tools for application.To identify an OS is a RTOS, it's necessary to analyze the system architecture and realization technology. The first step is to study the requirement of real-time system. This induces the minimum requirements of a RTOS. The next step is to examine techniques that can be found in General Purpose Operating Systems (GPOS) and explain why they can or cannot be used in real-time operating systems. These techniques include OS structures, task-mode, memory management, and interrupt technologies. All this above will be used as the reference of RTOS technical evaluation. And also, a good RTOS should provide sufficient API and friendly development environment for application development. Another section evaluates the performance of RTOS. The evaluation is based upon a series of practical tests. The testing measures low-level operations of a RTOS including Task Management, Memory Management, Interrupt, IPC Mechanism, File System, and Network Stack. Interrupt as an example, there are 4 main features should be studied and tested: Interrupt Latency, Interrupt Dispatch Latency, Interrupt Priority & Nest, and Maximum Sustainable Interrupt Frequency. The design idea of these tests is defining rational test items and designing standardization test procedure, ensuring the test results can be validated and compared.