Research Reform on Embedded Linux´s Hard Real-Time Capability in Application

To well support the hard real-time requirement for embedded applications, we enhance the real-time ability in Linux kernel through two new kernel mechanisms. Firstly, we focus on one of the major sources of unresponsiveness in the kernel, namely the presence of non-preemptible code sections, a new technique called normal task delayed locking technique can be used to reduce the OS latency. Secondly, because of the coarse-grained timer mechanism can not satisfy the microsecond-level timer resolution required by real-time tasks, we present a new microsecond-level timer mechanism, which is based on UTIME technique. The test result shows that the design can improve the real-time performance of the Linux system efficiently, which could be used to most of the embedded hard real-time systems.