International Business Machines Corporation

Francis E Johnson

Casper A Scalzi

Harry M Yudenfriend

Mark S Farrell

William J Rooney

Peter Bergersen Yocom

Steven G Glassen

Leslie W Wyman

Eugene P Hefferon

Allan Samuel Meritt

Roger E Hough

Thomas Edward Cook

Joseph C Elliott

Marten J Halma

Thomas J Dewkett

Glen A Brent

Gary M King

Peter H Gum

Donald W McCauley

Assaf Marron

Joseph A Williams

Terry L Borden

John C Rathjen, Jr

John Fenton Scanlon

James J Antognini

George H Bean

Kenneth R Veraska

Mark E Rakhmilevich

Donald W Mccauley

John C Rathjen

John F Scanlon

An impact of configuration changes on controllers is projected. This projection quantifies the impact for each controller affected by the change, such that it is known by a quantifiable value how much the change impacts the controller. In order to project the impact, a projected I/O velocity of the controller is determined.

Method, system and program products for projecting the impact of configuration changes on controllers

Automatic machine methods and apparatus for determining which components of an I/O configuration are shared by other components of the configuration. The information can be obtained through the use of existing self-description facilities and unique identifiers. By noting which channel paths are used to obtain configuration-data records and examining the unique identifiers provided for each I/O items it can be determined which I/O devices are accessible through the same control unit, and which control units provide access to the same I/O device. Furthermore, by examining the unique identifiers provided, it can be determined which I/O subsystems and which control units or channel subsystems are accessible through the same dynamic switch and which dynamic switches provide access to the same I/O subsystem of channel subsystem. A programmable subchannel is provided to enable communication between a CEC and an electrically-connected I/O item not represented in the current I/O configuration description being used by the CEC. Without the programmed subchannel, the CEC cannot access any I/O item not represented in the CEC's current I/O configuration description.

Method and apparatus for automatic generation of I/O configuration

Coupling execution of channel programs without central processing unit supervision controls data transfer between input/output devices through a main storage of a data processing system. In one embodiment, channel programs to be coupled are generated by a program running on a data processing system central processing unit. The channel program on the input subchannel includes channel commands referencing the output subchannel and operating to cause resumption of the output subchannel. The channel program on the output subchannel includes suspend channel commands directed to itself which correspond to the resume channel commands in the channel program on the input subchannel. In alternative embodiments values in channel commands can change values in, or reference, control blocks to effect execution of other channel programs.

System for coordinating execution of multiple concurrent channel

Provides a software-to-software interface and a software-to-hardware interface between software users and a hardware ADM facility (ADMF) in a data processing system. Such software user presents only virtual addresses to the software-to-software interface in a MSB list. The user list defines virtual address spaces, including a 'hiperspace', in a manner that represents physical backing media as different random-access electronic storages, such main storage (MS) and expanded storage (ES). The real data transfers are within or between the backing storages. The user list is transformed into an ADM operation block (AOB), which is assigned an ADM UCB in a UCB queue which is associated with an ADM subchannel. The software-to-hardware interface generates an ORB, containing the AOB address, as an operand of a SSCB instruction which is executed to queue the associated subchannel onto one of plural co-processor queues in the ADMF. The ADMF uses the AOB to perform the requested page moves, and generates an interruption upon completion of each request which is sent to the hardware-to-software interface to remove the associated ADMF request from the ADM software request queue and free the associated ADM UCB for use by another user request.

Method and means for enabling virtual addressing control by software

The embodiment discloses a method and means for partitioning the resources in a data processing system into a plurality of logical partitions. Host control code may be embodied in programming, microcode, or by special hardware to enable highly efficient operation of a plurality of preferred guest programming systems in the different partitions of the system. The main storage, expanded storage, the channel, and subchannel resources of a system are assigned to the different logical partitions in the system to enable a plurality of preferred guest programming systems to run simultaneously in the different partitions. This invention automatically relocates the absolute addresses of the I/O channel and subchannel resources in the system to their assigned partitions. Also the absolute and virtual addresses of the different guest programming systems are relocated into, as well as page addresses for any expanded storage, their assigned partitions. The guest programming systems generally will be different operating systems. The logical CPU(s) of the guests are dispatched on one or plural real CPUs in the system using the S/370XA SIE (start interpretive execution) instruction. Special operations are provided, including the CPU alerting of other guests in different partitions using I/O interruption signalling. Interception is provided to handle special circumstances.

Logical resource partitioning of a data processing system

Growing community of inventors

Poughkeepsie, NY, United States of America

Francis E Johnson