Real Time Operating System for embedded Symmetric Multiprocessor System.

多处理器系统最近在嵌入式系统领域取得了进展。嵌入式系统的要求因系统而异。有些系统需要实时性，有些系统强调吞吐量，有些系统同时需要这两种属性。在多处理器系统中也有各种各样的硬件体系结构。我们定义了适用于各种多处理器系统的多处理器RTOS规范，并将其作为TOPPERS/FMP内核实现。TOPPERS/FMP内核允许一个处理器发出一个系统调用，这符合ITRON规范，在同一个多处理器系统中的另一个处理器。为了支持适合每个系统的负载平衡算法而不失去实时性，TOPPERS/FMP内核提供了通过应用程序使用系统调用而不是通过RTOS内核的自动负载平衡，使任务从当前处理器按需迁移到另一个处理器的能力。我们已经证实，任务迁移功能使程序能够在应用程序级别实现几种负载平衡算法。

Multiprocessor systems are recently making advancements into the embedded systems field. The requirements of embedded systems differ from system to system. Some systems require real-timeliness, others emphasize throughput, and some require both properties at the same time. There are also a great variety of hardware architectures in multiprocessor systems. We have defined the RTOS specification for multiprocessors which is applicable to various multiprocessor systems, and implemented it as the TOPPERS/FMP kernel. The TOPPERS/FMP kernel allows a processor to issue a system call, which conforms to the ITRON specification, to another processor in the same multiprocessor system. In order to support a load balancing algorithm fitted for each system without losing real-time property, the TOPPERS/FMP kernel provides the capability to make a task migrate from the current processor to another on-demand by the application using a system call rather than by automatic load balancing of the RTOS kernel. We have confirmed that the task migration functionality enables programs at the application level to realize several kinds of load balancing algorithms.