Deitel, H.M. Operating Systems. (2nd ed.). Addison Wesley, 1990.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....of 34 runs. Processes run more quickly with the Elevator scan, but the last process takes 6 7 times longer to complete than the first. With the N CSCAN scheduler, there is less variation in the distribution of running times, but all of the jobs are much slower. the schedule for the next scan [5]. The resulting scheduler is fair in the sense that the expected latency of each disk operation is proportional to the length of the request queue at the time the disk begins its next sweep. Only a small patch is needed to change the current FreeBSD disk scheduler to N CSCAN. We have implemented ....

Harvey M. Deitel. Operating Systems, 2nd Edition. Addison-Wesley Publishing Company, 1990.

.... client server architecture emerged to replace the monolithic systems of the mainframe computing [Berson, 1992] A type of client server architecture is the event driven model and it is commonly used in the design of GUIs for modern multi tasking operating systems or in real time applications [Lorin and Deitel, 1981, page 69] In the latter case, it is also called queue driven, in contrast with the process driven model. In the event driven model (Figure 1) the event dispatcher acts as an intermediary between the input devices and the applications. The event dispatcher is the server and the applications are ....

Lorin, H. and Deitel, H. M. (1981). Operating Systems. The Systems programming series. Addison-Wesley Publishing Company Inc.

....which is consistent with Silberschatz s textbook on operating systems. 5] Deitel s textbook on operating systems uses the name C SCAN for the same algorithm, which does not automatically seek to the extremes of the disk during each pass, unlike Silberschatz s description of SCAN and CSCAN. [6] 7 Chapter 3 The Block Release Sharing (BRS) Algorithm The Block Release Sharing (BRS) algorithm manages a central buffer with fixed size blocks for a variable period continuous media server. BRS coordinates disk reading to keep the buffer as full as possible while minimizing the space ....

Harvey M. Deitel. Operating Systems. Addison-Wesley, second edition, 1990.

....mechanism is required to update the set of stored states as the system drifts to new state regions. Such a mechanism can be provided, for instance, by time stamping the stored states with the last time that they were visited during the system operation a variation of a scheme known as aging [14]. An application of the combination of Polynomial Kernel deadlock avoidance policies with partial search can be found in [38] 7 Additional Issues and Future Directions in FMS Structural Control The starting point of this chapter has been the observation that current trends in discrete part ....

H. M. Deitel. Operating Systems. Addison Wesley, Reading, MA, 1990.

....area is achieved by using secondary storage to make objects persist transparently, saving them when not placed in the instance area (or no more room in left in it) Re ection can be used to implement this behaviour in a exible way. Traditional virtual memory techniques of operating systems [Dei90] and object persistence are uni ed. A virtually in nite, unique space in which objects reside inde nitely is provided. A prototype implementation of complete persistence for the Oviedo3 system was developed to gain experience with complete persistence. An intermediate memory (cache or virtual ....

H.M. Deitel. Operating Systems. Addison-Wesley, 2nd edition, 1990.

....In virtual memory management units, LRU could require substantial overhead since it requires that each memory page be timestamped whenever it is referenced. Therefore, LRU is not implemented in most of the current memory management units, but is approximated by other lower overhead strategies [3]. In the field of file systems and file transfer protocols, LRU can be realized in software with less effort and less overhead. Filesystems like Andrew [12] take advantage of this fact by providing LRU cache management for client workstations. In contrast to the FIFO algorithm, LRU does not ....

Deitel, H. M. Operating Systems, second ed. Addison Wesley, 1990.

....demands of different multimedia applications, it may be necessary to give different priorities for the same process depending on the nature of the competing processes at that time. It has been observed that the assignment of priorities and the dynamic adjustment of priorities are often ad hoc [21]. Fair share schedulers [22] have been proposed for distributing CPU resources fairly over long periods of time (several minutes) Techniques also exist for achieving service rate objectives using decayusage scheduling [23] These schemes monitor the CPU usage and dynamically alter the priorities ....

H. Deitel. Operating systems. Addison Wesley, 1990.

....cylinder where the disk arm is currently positioned. We assume that the query is blocked while the disk satisfies one of its requests. Several multipage requests of different queries are waiting in front of the disk in a request queue to receive service from the disk. The circular SCAN (C SCAN) Dei90] scheduling strategy is used for selecting the next request which receives service from the disk. Any of the well known disk scheduling policies [Dei90] can be used for organizing the request queue. This approach to query processing has basically two advantages. First, it prevents a multi page ....

....requests of different queries are waiting in front of the disk in a request queue to receive service from the disk. The circular SCAN (C SCAN) Dei90] scheduling strategy is used for selecting the next request which receives service from the disk. Any of the well known disk scheduling policies [Dei90] can be used for organizing the request queue. This approach to query processing has basically two advantages. First, it prevents a multi page request from occupying the disk for a very long time period. Second, the size of the buffer required for a multi page request is limited by the capacity ....

H. M. Deitel. Operating Systems. Addison-Wesley, 1990.

....this thesis in context by presenting an overview of related work. Computational resource management techniques from a variety of fields are briefly summarized; a more complete discussion appears in Chapter 7. The dominant processor scheduling paradigm in operating systems is priority scheduling [Dei90, Tan92] Conventional timesharing policies employ dynamic priority adjustment schemes based on ad hoc, non linear functions that are poorly understood. Manipulating scheduling parameters to achieve specific results in such systems is at best a black art. 1 Attempts to control service rates ....

....related topics in priority scheduling, real time scheduling, fair share scheduling, proportional share scheduling, microeconomic resource management, and rate based network flow control. 7. 1 Priority Scheduling Conventional operating systems employ numerical priorities for scheduling processes [Dei90, Tan92] A priority scheduler simply grants the processor to the process with the highest priority. Thus, priorities represent absolute resource rights, since a process with higher priority is given absolute precedence over a process with lower priority. The use of static priority values can lead ....

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Harvey M. Deitel. Operating Systems. Addison-Wesley, Reading, Massachusetts, 1990.

....manage machine resources within the kernel [5] affording clients only crude control through ad hoc interfaces that inhibit modularity. For example, dynamic priority schedulers are difficult to understand, provide poor control over service rates, and violate modular abstraction principles [2, 6, 7, 16]. This paper advocates a radically different approach to computational resource management. Tickets are first class objects that represent resource rights, allowing clients to express a wide range of resource management policies. Currencies abstract collections of tickets to permit modular ....

....6. Related Work As mentioned earlier, traditional operating systems provide only crude control over resource management. For example, dynamic priority schedulers, which are the dominant paradigm for managing processor time in modern operating systems, are complex, ad hoc, and hard to understand [2, 7, 6]. Resource rights do not vary smoothly with priorities. Priority mechanisms also violate modular abstraction principles: when separately developed modules are combined, the internal priority values in each must be exposed to understand resource allocation in the resulting system. For other ....

H. M. Deitel. Operating Systems. Addison-Wesley, Reading, MA, 1990.

....We then describe current proxy cache evaluation methods and place existing research in this space. 2 Background Caching has a long history and is a well studied topic in the design of computer memory systems (e.g. HP87, Man82, MH99] in virtual memory management in operating systems (e.g. Dei90, GC97] in file systems (e.g. CFKL95] and in databases (e.g. SSV96] Caching on the Internet is also performed for other network services such as DNS [Moc87a, Moc87b] Gopher and FTP [Pet98, Wes98, RH98, Cat92] and in fact much of today s web caching research can be traced back to the ....

Harvey M. Deitel. Operating Systems. Addison-Wesley, Reading, MA, 1990. Second Edition.

....goals that are more general than proportional sharing. However, when proportional sharing is the goal, stride scheduling has advantages in terms of efficiency and accuracy. 7. 3 Priority Schedulers Conventional operating systems typically employ priority schemes for scheduling processes [Dei90, Tan92]. Priority schedulers are not designed to provide proportional share control over relative computation rates, and are often ad hoc. Even popular priority based approaches such as decay usage scheduling are poorly understood, despite the fact that they are employed by numerous operating systems, ....

H. M. Deitel. Operating Systems, AddisonWesley, 1990.

....Douglis and Ousterhout, 1991; Douglis and Ousterhout, 1991] The synchronisation of concurrent processes require that processes that are concurrently executing are allowed to finish prior to the rest of the program continuing. The operating system is the logical place for this [Ben Ari, 1990; Deitel, 1990; Goscinski, 1991] It is the operating system that is responsible for process control [Goscinski, 1991; Goscinski and Zhou, 1994] and it is logical for the operating system to make decisions in regard to monitoring processes and what to do upon failure of processes. It has been proposed that a ....

....do upon failure of processes. It has been proposed that a compiler can be used to address and solve the first issue listed above [Goscinski and Zhou, 1994] A compiler can be used to detect parts of code that can be executed in parallel. This is already done when optimising loops for the Cray Y MP [Deitel, 1990] and can be shown to work for problems listed in Section 2.4 [Kumar et al. 1994] A compiler can be used to detect when program synchronisation should occur. This information can be passed from the compiler to the operating system to help control the flow of the program. This rest of this report ....

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Deitel, H.M. (1990) Operating Systems, 2nd Ed, Reading, Massachusetts: Addison-Wesley Publishing Company.

....priority that does not provide the encapsulation and modularity properties required for the engineering of large software systems. In fact, with the exception of hard real time systems, it has been observed that the assignment of priorities and dynamic priority adjustment schemes are often ad hoc [Dei90]. Even popular priority based schemes for CPU allocation such as decay usage scheduling are poorly understood, despite the fact that they are employed by numerous operating systems, including Unix [Hel93] Existing fair share schedulers [Hen84, Kay88] and microeconomic schedulers [Fer88, Wal92] ....

....scheduling tasks. A task with higher priority is given absolute precedence over a task with lower priority. Priorities may be static, or they may be allowed to vary dynamically. Many sophisticated priority schemes are somewhat arbitrary, since priorities themselves are rarely meaningfully assigned [Dei90]. The ability to express priorities provides absolute, but extremely crude, control over scheduling, since resource rights do not vary smoothly with priorities. Conventional priority mechanisms are also inadequate for insulating the resource allocation policies of separate modules. Since ....

H. M. Deitel. Operating Systems, Addison-Wesley, 1990.

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Deitel, H.M. Operating Systems. (2nd ed.). Addison Wesley, 1990.

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Harvey M. Deitel, Operating Systems, 2nd Edition. Addison-Wesley Publishing Company, 1990.

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H.M. Deitel, Operating Systems, Addison Wesley, 1990.

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H.M. Deitel, Operating Systems, Addison Wesley, 1990.

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