The use of simulation and computation to develop realistic computable models of multiaccess time sharing systems is considered. Work on tasks is described as a series of transport- and compute times for ″subtasks″ ....
详细信息
The use of simulation and computation to develop realistic computable models of multiaccess time sharing systems is considered. Work on tasks is described as a series of transport- and compute times for ″subtasks″ . A nearly optimal CPU scheduling strategy was developed. It is shown that simulation is suitable to optimize strategies in operating systems.
This concept, when implemented in an operating system control program, supports parameter lists composed on noncontiguous entries. Normally, a variable-length parameter list consists of any number of contiguous entrie...
详细信息
This concept, when implemented in an operating system control program, supports parameter lists composed on noncontiguous entries. Normally, a variable-length parameter list consists of any number of contiguous entries with the last entry having its high-order bit set to 1. If that parameter list must reside in storage which has a relatively small maximum block size, its length is restricted accordingly. Disjointed parameter list processing is intended to eliminate such a restriction without requiring the parameter list user to be sensitive to the chaining mechanism, which connects the physically separate parts of a logically single parameter list.
By using new numerical methods it is possible to compute quickly and with a sufficient degree of accuracy complicated potential fields (electrostatic, thermostatic, magnetic fields, etc. ). The program system POT 123,...
详细信息
By using new numerical methods it is possible to compute quickly and with a sufficient degree of accuracy complicated potential fields (electrostatic, thermostatic, magnetic fields, etc. ). The program system POT 123, developed specially for such purposes by Siemens, employs the method of finite differences for solving the homogeneous Laplace equation used here. The author discusses the characteristics of the program and gives examples of application as well as results from his investigations into computation times.
Release page is a supervisor service, which functions to make available all real and auxiliary storage wholly associated with an area of virtual address space. The virtual address space remains allocated, i. e. , the ...
详细信息
Release page is a supervisor service, which functions to make available all real and auxiliary storage wholly associated with an area of virtual address space. The virtual address space remains allocated, i. e. , the area remains addressable, but the contents of the address space are released.
The history of IBM efforts in the area of Private Line Switching, the functions that the 3750 Switching System can perform, as well as its general architecture are recalled, with a special emphasis on the choices whic...
详细信息
The history of IBM efforts in the area of Private Line Switching, the functions that the 3750 Switching System can perform, as well as its general architecture are recalled, with a special emphasis on the choices which have an influence on the programming. The operational program is then described with its synchronous and asynchronous parts, with a special emphasis on the concepts which are peculiar to the 3750. The utility programs such as error handling, maintenance and service, are also explained as well as an illustration of the progress of a call and of data collection. The last part of the paper describes the logistics of the program, such as the simulation program, the tests, as well as the generation of the program and the tables according to the specific configuration of each user.
This is a page replacement process utilizing a set of ″Interreference Interval Probabilities″ in making page replacement decisions. This technique reduces the number of incorrect steal decisions made, by advising th...
详细信息
This is a page replacement process utilizing a set of ″Interreference Interval Probabilities″ in making page replacement decisions. This technique reduces the number of incorrect steal decisions made, by advising the paging supervisor of a specific page's expected interreference time and the probabilities thereof. The accessed probability value is then employed in the page replacement decision. Such a process can be applied to a single group of ″different″ pages (those involved in conversational/interactive processes), or to multiple groups of pages (each group having a different set of interreference interval probabilities) simply by making provision for multiple Probability Tables.
This is a system for scheduling of tasks and synchronization of synergetic tasks. The scheduler is described schematically, and construction of a schedule (matrix S) and of its associated string of tasks (vector a) is...
详细信息
This is a system for scheduling of tasks and synchronization of synergetic tasks. The scheduler is described schematically, and construction of a schedule (matrix S) and of its associated string of tasks (vector a) is illustrated.
A monitor program is described which provides a statement usage count that can be used to ″tune″ the monitored program and to provide an aid to debugging. The monitor is written in PL/I.
A monitor program is described which provides a statement usage count that can be used to ″tune″ the monitored program and to provide an aid to debugging. The monitor is written in PL/I.
An operating system control program must create and maintain a record of each resource in a computer system allocated to a user, including information on the restrictions/limits on that allocation. In order to safegua...
详细信息
An operating system control program must create and maintain a record of each resource in a computer system allocated to a user, including information on the restrictions/limits on that allocation. In order to safeguard system security/integrity, the resource record must be maintained in a control block or group of control blocks that are protected, i. e. , cannot be changed by the user. A control block structure/validity-checking mechanism is described that provides the necessary verification when the user program is allowed to supply a privileged control program routine with the address of a single protected control block that records his allocation to a particular resource.
暂无评论