Information processing system and logout process therefor

• US 4,395,755 A
• Filed: 02/06/1981
• Issued: 07/26/1983
• Est. Priority Date: 02/06/1980
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Wakai, Katsuro
• Primary Examiner(s): ATKINSON, CHARLES
• Application Number:
  US06/232,001
• Time in Patent Office: 900 Days
• Field of Search: 371/29, 371/16, 371/18, 364/200, 364/900
• US Class Current: 711/166
• CPC Class Codes: G06F 11/0745 in an input/output transactions management context input/output processing in general G06F13/00
• CPC Class Codes: G06F 11/0757 by exceeding a time limit, i.e. time-out, e.g. watchdogs
• CPC Class Codes: G06F 11/0772 Means for error signaling, e.g. using interrupts, exception flags, dedicated error registers

Abstract

An information processing system and a logout process therefor wherein when an error takes place in a storage control unit the storage control unit is inhibited from receiving storage access requests from other processing units such as basic processing unit and I/O processing unit and the error is reported to a maintenance control unit, the said other processing units are inhibited from performing time-out detecting operation, internal information of the storage control unit at the time when the error takes place is fetched therefrom and stored in the maintenance control unit, then the inhibition of the storage access request reception and the inhibition of the time-out detecting operation are removed, and the internal information is transferred from the maintenance control unit to a certain memory for later analysis of the error.

Claims

1. An information processing system comprising a main storage, at least one processing unit, a storage control unit and a maintenance control unit for said storage control unit and said processing unit, said storage control unit being interposed between said main storage and said maintenance control unit as well as between said main storage and said processing unit for controlling said main storage upon receipt of storage access requests from said maintenance control unit and said processing unit, and in which:

said processing unit includes means for detecting a timeout and for inhibiting said storage control unit in response thereto;

said storage control unit includes means responsive to detection of an error in said storage control unit for inhibiting said storage control unit from receiving said storage access requests and for reporting said detected error to said maintenance control unit; and

said maintenance control unit includes logout control means responsive to reception of said reported error in said storage control unit for inhibiting said time-out detecting means in said processing unit, and buffer memory means responsive to said inhibiting of said time-out detecting means for fetching from said storage control unit internal information representative of the state of said storage control unit at the time when said error took place and for storing said fetched internal information;

said error detection means in said storage control unit including means responsive to said logout control means at the completion of said internal information storing in said maintenance control unit for removing said inhibiting of said storage access request reception.

2. A system according to claim 1, in which said at least one processing unit includes a basic processing unit and an input/output processing unit.

3. A logout process for an information processing system including a main storage, at least one processing unit, a storage control unit and a maintenance control unit for said storage control unit and said at least one processing unit, said storage control unit serving to receive storage access requests from said maintenance control unit and said at least one processing unit, the process comprising the steps of:

inhibiting said storage control unit from receiving storage access requests when an error takes place in said storage control unit;

reporting said error to said maintenance control unit;

inhibiting said processing unit from performing time-out detecting operation in response to said reporting of said error;

fetching from said storage control unit internal information representative of the state of said storage control unit at the time when said error took place and storing it in said maintenance control unit in response to said inhibiting of said time-out operation;

removing said inhibiting of said storage access request reception and said time-out detecting operation in response to said storing of said internal information; and

transferring said internal information from said maintenance control unit to a storing means.

4. A logout process according to claim 3, in which said storing means is said main storage.

5. A logout process according to claim 3, in which said storing means is an external memory.

6. An information processing system comprising a main storage, at least one processing unit, a storage control unit, a maintenance control unit for said storage control unit and said at least one processing unit, said storage control unit being interposed between said main storage and said maintenance control unit and between said main storage and said at least one processing unit for controlling said main storage upon receipt of storage access requests from said maintenance control unit and said at least one processing unit, and a storage means, in which:

said at least one processing unit includes means for detecting a time-out;

said storage control unit includes means for detecting an error in said storage control unit and means responsive to an error detection by said error detecting means for inhibiting said storage control unit from receiving said storage access requests; and

said maintenance control unit includes buffer memory means connected with said storage control unit for storing internal information representative of the state of said storage control unit at the time when said error took place and logout control means for control of a logout of said internal information, said logout control means being responsive to said error detection by said error detecting means in said storage control unit for inhibiting time-out detection by said time-out detecting means in said processing unit, and for instructing storage of said internal information in said buffer memory means, said logout control means removing, after storage of said internal information in said buffer memory means, said inhibiting of said storage access request reception by said storage control unit and removing said inhibiting of said time-out detecting operation by said time-out detecting means, and said logout control means then transferring said internal information from said maintenance control unit to said storage means.

7. A system according to claim 6, in which said storage means is constituted by part of said main storage.

8. A system according to claim 6, in which said storing means is constituted by an external memory.

9. A system according to claim 6, in which said at least one processing unit comprises a basic processing unit and further comprising an input/output processing unit also connected to said storage control unit and including further time-out detecting means controlled by said logout control means.