Hitachi, Ltd.

Akira Otsuji

Hirofumi Nagasuka

Yuzuru Maya

Kenta Ninose

Taketoshi Sakuraba

Masaya Ichikawa

Takeshi Shigeno

Masahiro Kiyoi

According to the present invention, as regards a computer system that uses virtual storage management, because content of auxiliary storage utilized by paging is used, dump information can be obtained by outputting only a part of the content of the auxiliary storage at the time of occurrence of an abnormal system condition. As a result, time required to restart the computer system and business can be shortened. What is more, because it is not necessary to add a special external storage for obtaining dump information, computer resources can be utilized more efficiently.

Method and apparatus for getting dump of a computer system

A data transfer method for a computer system in which a computer is logically divided into a plurality of logical processing units and a logical coupling unit. A correspondence between a start of physical addresses of a memory of each logical processing units in a memory of the computer is stored in advance. If a first logical processing unit issues a write command to the logical coupling unit by designating a logical address of data, the logical coupling unit stores an identifier and the logical address of the first logical processing unit. If a second logical processing unit issues a read command of the data, a physical address of data storage corresponding to the logical address of the first logical processing unit is calculated in accordance with the identifier and the logical address of the first logical processing unit and the address correspondence. The data is read by using the calculated physical address.

Data transfer method for logical computers

An enqueue structure type is provided within a coupling facility to record the use state and to manage a request queue of resources shared among programs on computers of a system. All programs to use a shared resource issue a request to reserve the shared resource to the coupling facility before using it. The coupling facility affords the permission to use the resource to the programs if it is usable, and adds the programs to the resource request queue if unusable. When a program using the shared resource frees it, the coupling facility fetches a program from the beginning of the request queue, reserves the shared resource for the next program and notifies the next program that the use of the shared resource has been approved. On receiving the notification, the program uses the shared resource without asking the coupling facility for the approval of the use of the shared resource again. Further, exclusive control of shared resources by use of a spin lock having shared and exclusive attributes is implemented by using two locks for one shared resource, wherein the first lock is reserved and then freed after the second lock is reserved.

Method for managing shared resources

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Yokohama, Japan

Akira Otsuji