A comparison of OS extension technologies

摘要: The current trend in operating systems research is to allow applications dynamically extend the kernel improve application performance or functionality, but most effective approach extensibility remains unclear. Some use safe languages permit code be downloaded directly into kernel; other provide in-kernel interpreters execute extension code; still others software techniques ensure safety of extensions. key characteristics that distinguish these are philosophy behind and technology used implement extensibility. This paper presents a taxonomy types extensions might desirable an extensible system, evaluates cost various technologies currently being employed, compares adding benefit having kernel. Our results show compiled (e.g. Modula-3 fault isolation) good candidates for implementing general-purpose extensions, overhead interpreted sufficiently high they inappropriate this use.