Evolving an operating system for the Web

Considering the drive to standardize operating system technology and the frantic pace of innovative application development on the Internet and World Wide Web, what is left for OS developers to do? The paper discusses some of the basic functions of operating systems and considers the development of a Web-oriented OS     

Priority queuing in an operating system

The analysis of a preemptive priority queuing system with K(⩾2) classes of jobs is undertaken. The system consists of a single processor representing a model of discrete dynamic scheduling problems associated with M_k/G_k/1/∞ endogenous priority queues. The processor schedules jobs which arrive according to a Markov arrival process. The process of service is arbitrary. With each job are associated particular endogenous dynamic priorities, called scheduling by “mean bounded priorities with arrival pattern” (MBPAP). The main goal is, for the case of an arrival pattern of jobs, to present an original scheduling strategy, to derive the waiting time w_k(t) and to discuss the implementation of the priorities. This queuing system is investigated.     

Design and implementation of an operating system for composable processor sharing

Multi-Processor Systems on Chip (MPSoC) run multiple independent applications, often developed by different parties. The applications share the hardware resources, e.g. processors, memories and interconnect. The sharing typically causes interference between the applications, which severely complicates system integration and verification. Even if the applications are verified in isolation, the system designer must verify the combined behaviour, leading to an explosion in design complexity. Composable MPSoCs have no interference between applications, thus allowing independent design and verification. For an MPSoC to be composable, all the hardware resources must offer composability. A particularly challenging resource is the processors, often purchased as off-the-shelf intellectual property.In this work we present the design and implementation of CompOSe, a light-weight (only 1500 lines of code) composable operating system for MPSoCs. CompOSe uses fixed-size time slices, coupled with a composable scheduler, to enable composable processor sharing. Using instances of ARM7, ARM11 and the Xilinx MicroBlaze we experimentally demonstrate the ability to provide temporal composability, even in the presence of dynamic application behaviour and multiple use cases. We do so using a diverse set of processor architectures, without requiring any hardware modifications. We also show how CompOSe allows slack to be distributed within and between applications through a novel two-level scheduler and slack-distribution system.     

操作系统灵活内核技术

在可扩展操作系统研究中存在两种途径,但这两种途径都存在明显的缺陷.在对这些问题研究的基础上,提出了灵活内核技术,它改变以往可扩展操作系统的研究思路,不仅仅支持通过系统扩展软件对系统进行扩展,而且允许动态配置扩展软件的运行位置,从而使得系统在获得了更强扩展特性的同时,在其它一些性能方面也得到了改善.进一步讨论了灵活内核技术实现的一般性问题,并以Elastos操作系统为例进行了说明.     

Towards an immortal operating system in virtual environments

Many OS crashes are caused by bugs in kernel extensions or device drivers while the OS itself may have been tested rigorously. To make an OS immortal we must resurrect the OS from these crashes. We present a novel OS-hypervisor infrastructure that allows automated and transparent OS crash diagnosis and recovery in a virtual environment. This infrastructure eliminates the need for reboots or checkpoint-restart mechanisms, which require preserving the states of critical applications before the crash happens and also require extensive modifications to those applications. At the core of our approach is a small hidden OS-repair-image that is dynamically created from the healthy running OS instance. When an OS crashes, the hypervisor dynamically loads this repair-image to perform diagnosis and repair. One way of repair we have experimented with, is to quarantine the offending process and resume the running of the fixed OS automatically without a reboot. Experimental evaluations demonstrated that it takes less than 3 s to recover from an OS crash. This approach can significantly reduce the downtime and maintenance costs in data centers, and is the first design and implementation of an OS-hypervisor combo capable of automatically resurrecting a crashed commercial server-OS. In addition to online diagnosis and recovery, this infrastructure can also be used for offline diagnosis and can be incorporated into the technical support tools of the OS vendor. Additionally, we have used parts of this infrastructure to speed-up the diagnosis of AIX OS-crashes for the IBM technical support teams.     

Emulating an operating system on top of another

In this paper, we present the design of an operating-system emulator. This software interface provides the services of one operating system (Oberon) on a machine running a different operating system (Macintosh), by mapping the functions of the first onto equivalent calls to the second. The construction of this emulator proceeded in four distinct phases, documented here through examples from each of these phases. We believe that our four-phase approach can be beneficial whenever a larger software system needs to be adapted from one architecture onto another. In conclusion, we relate some of the lessons learned and propose guidelines for similar engineering projects.     

XiUOS:an open-source ubiquitous operating system for industrial Internet of Things

On May 4,2021,a Chinese research team with members from AIIT (PKU Advanced Institute of Information Tech-nology),PKU (Peking University),and SJTU (Shanghai Jiao...     

The design of an operating system for a scalable parallel computing engine

There are substantial benefits to be gained from building computing systems from a number of processors working in parallel. One of the frequently-stated advantages of parallel and distributed systems is that they may be scaled to the needs of the user. This paper discusses some of the problems associated with designing a general-purpose operating system for a scalable parallel computing engine and then describes the solutions adopted in our experimental parallel operating system. We explain why a parallel computing engine composed of a collection of processors communicating through point-to-point links provides a suitable vehicle in which to realize the advantages of scaling. We then introduce a parallel-processing abstraction which can be used as the basis of an operating system for such a computing engine. We consider how this abstraction can be implemented and retain the ability to scale. As a concrete example of the ideas presented here we describe our own experimental scalable parallel operating-system project, concentrating on the Wisdom nucleus and the Sage file system. Finally, after introducing related work, we describe some of the lessons learnt from our own project.     

A general-purpose natural language interface to an operating system

One of the most difficult tasks facing new computer users is the management of data and programs through an operating system (OS) interface. Both command languages and graphical interfaces can impede a user unfamiliar with the terminology and organizational techniques of modern file management systems. Various attempts have been made in recent years to develop systems that will enable users to interact with the computer in natural language. By simplifying the form of user input to an OS, such interfaces allow the user to concentrate on file management tasks rather than on the means of expressing OS-specific instructions. The Informational Network for a Natural Talking (INFANT) System was originally developed as a conversational system for communication at the level of a small child. It has since been adapted for use as a general-purpose English language interface for standard OS file management operations. The INFANT System reduces an input sentence to a hierarchy of standardized propositional forms, which are mapped through a propositional knowledge base and a compositional semantics process into a high-level representation of meaning. Its effectiveness as a working natural language interface has been verified in a pair of experiments performed in a college computer lab. © 1996 John Wiley & Sons, Inc.     

An exercise in the transportation of an operating system

An attempt lo transport an operating system and some associated software from one machine to another is described. Some comments are made on the suitability of the system for such a task, and some recommendations are put forward to future operating system writers to assist in making their systems more portable.     

A network operating system for microcomputers

The design philosophy of this portable network operating system is based on the client-server model, and uses layering techniques based on the network architecture proposed by Mimica and Marsden. The PNOS uses a uniform interprocess communications mechanism to handle both interhost and intrahost communications, using the concept of ports. It has been designed for implementation as a ‘guest layer’, using an existing operating system base, thus retaining the system call conventions of the base operating system. In this way, the great majority of application software and utilities written for the base operating system can still be used with PNOS. The pilot version has been implemented over CP/M 80. Issues such as the design of suitable supporting high-level protocols, and handling of different naming conventions, are for further study.     

Network operating system for telecommunications applications

Computers are being used in modern telecommunications networks to control the switching systems and to assist with other aspects of their operation, such as maintenance or subscriber services. These applications require a range of operating system services in a distributed network environment, hence the term network operating system (NOS). The design concepts and major features of LM Ericsson's NOS are described, emphasis being placed on the use of functional layering to achieve adaptability. Attention is also drawn to the similarity between the problems which the NOS addresses and those that many organizations with face in coping with distributed processing.     

An operating system for interactive terminals

Conventional operating systems have for many-years used the ideas of standard stream interfaces to peripherals. Multi-tasking has been used in order to give an efficient response while maintaining simplicity and flexibility for the user. This paper describes an extension to an operating system which makes similar facilities available for the control of interactive workstations, and also provides a command dispatcher which enables the straightforward implementation of arbitrary user-defined command languages. The current system has been written in BCPL to run on a PDP 11/45 handling a Vector General display, but the design is suitable for use with a variety of terminals, computers and languages.     

Performance evaluation of a single-stage two-product manufacturing system operating under pull-type control

This paper presents a model to analyze a manufacturing system that is operating under pull-type control. A Markovian polling model with finite queues is devised to represent the manufacturing system and studied under three cyclic service policies: exhaustive, gated, and a type of limited policy. These polling models are solved by two different methods: an exact approach that requires the complete characterization of the system as a Markov chain and a decomposition approach that reduces the size of the Markov chain. A set of numerical experiments show that the decomposition approach is quite accurate in estimating system performance measures.     

Performance considerations for integrated voice and data networks

Performance considerations, particularly network delays, for integrated voice and data networks are reviewed. The nature of the delay problem is discussed, followed by a review of concepts, objectives and advances in enhanced circuit, packet and hybrid switching techniques, including fast circuit switching (FCS), virtual circuit switching (VCS), buffered speech interpolation (SI), packetized virtual circuit (PVC), cut-through switching (CTS), composite packets and various frame-management strategies for hybrid switching.In particular, the concept of introducing delay to resolve contention in SI is emphasized and, when applied to both voice talkspurts and data messages, this forms a basis for a relatively new approach to network design called transparent message switching (TMS). This approach and its potential performance advantages are reviewed in terms of various architectural aspects of integrated services networks, such as packet structure, multiplexing scheme, server structure and queuing performance, network topology and network protocols.A number of traffic-management strategies and their grade-of-service implications for voice service are discussed. These strategies include voice call and data session blocking, voice talkspurt and data message buffering, speech loss and data integrity and speech processing techniques, including variable quality, rate, speed and entropy coding. Emphasis is placed on the impact of variable delays on voice traffic, especially the importance of generating and preserving appropriate length speech talkspurts in order to mitigate the effects of variable network delay.