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Term Papers on Advanced Operating System C
Advanced Operating System C ESSAY-1 Micro kernels have made no impact on modern Operating Systems design Submitted by: Master of Computer Science School of Computer Science Contents: 1. Abstract 2. Introduction 3. Different type of operating system kernels design 3.1 Monolithic Kernels 3.2 Micro Kernels 3.2.1 First generation Micro Kernels 3.2.2 Second Generation Micro Kernels 4. Conclusion 5. References 1. Abstract There have been many approaches to the operating systems design. In particular, monolithic kernel and micro kernels are the two approaches, which play a vital role in the operating systems design. This essay is about the impact of micro kernels on modern operating system, i.e. though micro kernels have some performance degradations but still they have highly influenced the design of modern operating systems. 2. Introduction The history of operating system has evolved through several kinds of structures. Monolithic and micro kernels are the two main structures on which operating system has been designed. Systems based on monolithic architecture started out as simple, small structures and gradually added functionality without adding much structure, e.g. DOS, UNIX. On the other hand, in micro kernel architecture, services have been moduled and a small-simple kernel has been developed where kernel is shrinked to run a large number of servers as user-level processes, e.g. Mach, Chorus, L4. Apart from these two architectures, a new model called exokernel has been designed in which the kernel is only a secure hardware multiplexer. This essay includes discussion on above-mentioned architectures with respect to their impact on modern operating systems design. 3. Different type of Operating System kernels design 3.1 Monolithic Kernels Most of the early operating systems were based on monolithic kernels [2], e.g. UNIX OS. In this type of design, the major functionalities of OS, viz. networking, memory management, paging, etc are implemented in the kernel and are executed from the kernel mode only [1]. Usually monolithic kernels are not modular, so it is hard to implement a new functionality or modify the existing ones. This design has several limitations: · Since every function in the kernel has all the privileges, a bug in one part can corrupt data structure of another part. · Kernels often become very huge and hard to maintain. · As common libraries cannot be used so coding in kernel space is hard so as debugging and rebooting is often needed. 3.2 Micro Kernels 3.21 First generation Micro Kernels These micro kernels were the first kernels designed to achieve the goal of running applications faster than the monolithic kernels. The two most notable of these are L3, Chorus [3] and Mach [4]. Expected benefits from this type of micro kernels were · To achieve a small and simple kernel. · Highly modular structure. · To run device drivers as servers. But after all such expectations these types of micro kernels were inefficient as the cost of Remote Procedure Call, RPC turned out to be much higher than the simple system call to the kernel [5]. Secondly, while running the same application on micro kernel and monolithic based OS’s the cost of memory references turned out to be much higher in micro kernel based OS. Lastly, these types of micro kernels were inefficient because some of the implementation strategies and interfaces were inherited from monolithic kernels [6]. 3.22 Second generation Micro Kernels To improve the performance of micro kernels, new second-generation micro kernels have been designed. Some of these second-generation micro kernels are: Ø L4 L4 [7] is the direct offspring of L3, a fir... This is ONLY a preview of the article. If you would like to view the entire document, you must subscribe to Digital Term Papers. Please register below now! Digital Term Papers has over 63,000 essays, term papers, and book notes online. Many paper sites will charge you hundreds of dollars for a single paper. Digital Term Papers only charges $14.95 for a one month membership with instant account activation! Don't waste anymore time! Join NOW!!!
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