Conditional write processing for a cache structure of a coupling facility

• US 8,838,888 B2
• Filed: 03/19/2012
• Issued: 09/16/2014
• Est. Priority Date: 03/19/2012
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ahmad, Riaz, Elko, David A., Josten, Jeffrey W., Kurdt, Georgette, Schiffer, Scott F., Surman, David H.
• Primary Examiner(s): Chery, Mardochee
• Application Number:
  US13/423,640
• Publication Number:
  US 20130246713A1
• Time in Patent Office: 911 Days
• Field of Search: 711/118, 711/113, 711/154, 711/E12.033
• US Class Current: 711/113
• CPC Class Codes: G06F 12/0831 using a bus scheme, e.g. with bus monitoring or watching means
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 12/0888 using selective caching, e.g. bypass

Abstract

A method for managing a cache structure of a coupling facility includes receiving a conditional write command from a computing system and determining whether data associated with the conditional write command is part of a working set of data of the cache structure. If the data associated with the conditional write command is part of the working set of data of the cache structure the conditional write command is processed as an unconditional write command. If the data associated with the conditional write command is not part of the working set of data of the cache structure a conditional write failure notification is transmitted to the computing system.

Claims

1. A system for managing a cache structure of a coupling facility, the system comprising:

a processor unit configured to perform a method comprising;

receiving a conditional write command from a computing system;

determining whether a data associated with the conditional write command is part of a working set of data of the cache structure;

processing the conditional write command as an unconditional write command in the event the data associated with the conditional write command is part of the working set of data of the cache structure;

transmitting a conditional write failure notification to the computing system in the event the data associated with the conditional write command is not part of the working set of data of the cache structure, whereby the conditional write failure notification instructs the computing system to write the data associated with the conditional write command directly to a direct access storage device;

determining whether the data associated with the conditional write command is registered to a user other than the user performing the conditional write command; and

processing the conditional write command as an unconditional write command in the event the data associated with the conditional write command is registered to a user other than the user performing the conditional write command.

2. The system of claim 1, wherein the working set of data of the cache structure includes a set of data that is registered to one or more users.

3. The system of claim 1, wherein the working set of data of the cache structure includes a set of data that is frequently accessed.

4. The system of claim 1, wherein the conditional write failure notification instructs the computing system to write the data associated with the conditional write command directly to a direct access storage device.

5. The system of claim 1, wherein the method further comprises:

transmitting the conditional write failure notification to the computing system in the event the data associated with the conditional write command is registered to only the user requesting the conditional write command.