SYSTEM AND PROGRAM PRODUCTS FOR FACILITATING ACCESS TO STATUS AND MEASUREMENT DATA ASSOCIATED WITH INPUT/OUTPUT PROCESSING

• US 20090144586A1
• Filed: 02/03/2009
• Published: 06/04/2009
• Est. Priority Date: 10/10/2006
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Flanagan, John R., Casper, Daniel F.
• Granted Patent: US 7,984,198 B2
• Time in Patent Office: Days
• US Class Current: 714/37
• CPC Class Codes: G06F 13/126 and has means for transferring I/O instructions and statuses between control unit and main processor

Abstract

Input/output processing is facilitated by readily enabling access to information associated with input/output processing. This information includes status information and measurement data provided by a control unit executing input/output commands. The status and measurement data are provided in a status control block identified in a transport control word, which is further used to specify a location in memory that includes the input/output commands to be executed.

Claims

1. A system of facilitating input/output processing of a processing environment, said system comprising:

an input/output communications adapter of the processing environment to obtain a transport control word, said transport control word including a count of the total amount of data being transferred, an address of a descriptor control block to be sent to a control unit of the processing environment, in which the descriptor control block includes a plurality of input/output commands to be executed, an address of a list that informs the input/output communications adapter where to store or fetch data received from or transmitted to the control unit, and a location in memory where to store ending status from the control unit, said ending status being directly accessible by an operating system of the processing environment; and

said input/output communications adapter to forward to the control unit, in a single communication, the descriptor control block that includes the plurality of input/output commands as one entity, the control unit to execute the plurality of input/output commands to perform one or more input/output operations, wherein the executing is performed absent a tracking by the input/output communications adapter of state relative to the individual input/output commands of the plurality of input/output commands being executed by the control unit.

2. The system of claim 1, wherein the ending status is provided in a status control block identified by the location in memory.

3. The system of claim 2, wherein said status control block further comprises information relating to a failed input/output command of the plurality of input/output commands.

4. The system of claim 3, wherein said information comprises at least one of an indication of where execution of the input/output command was interrupted, and an indication of an amount of data not transferred for one or more input/output commands of the plurality of input/output commands.

5. The system of claim 1, wherein the control unit is further adapted to determine measurement data associated with execution of the plurality of input/output commands, and wherein the measurement data is provided in a status control block specified by the transport control word.

6. The system of claim 5, wherein the measurement data comprises at least one of a queue time parameter specifying an amount of time the control unit had an input/output operation on its queue with an exchange open to the input/output communications adapter, and a defer time parameter specifying an amount of time the control unit waited for data, with the exchange open to the input/output communications adapter because of a control unit data cache miss.

7. The system of claim 5, wherein the measurement data comprises a control unit active time specifying the time the control unit is active executing the transport control word.

8. An article of manufacture comprising:

at least one computer readable medium having computer readable program code logic to facilitate input/output processing of a processing environment, the computer readable program code logic comprising;

obtain logic to obtain by an input/output communications adapter of the processing environment a transport control word, said transport control word including a count of the total amount of data being transferred, an address of a descriptor control block to be sent to a control unit of the processing environment, in which the descriptor control block includes a plurality of input/output commands to be executed, an address of a list that informs the input/output communications adapter where to store or fetch data received from or transmitted to the control unit, and a location in memory where to store ending status from the control unit, said ending status being directly accessible by an operating system of the processing environment;

forward logic to forward from the input/output communications adapter to the control unit the descriptor control block that includes the plurality of input/output commands as one entity, wherein the forwarding includes forwarding from the input/output communications adapter to the control unit the descriptor control block including the plurality of input/output commands in a single communication; and

execute logic to execute by the control unit the plurality of input/output commands to perform one or more input/output operations, wherein the executing is performed absent a tracking by the input/output communications adapter of state relative to the individual input/output commands of the plurality of input/output commands being executed by the control unit.

9. The article of manufacture of claim 8, wherein the ending status is provided in a status control block identified by the location in memory.

10. The article of manufacture of claim 9, wherein said status control block further comprises information relating to a failed input/output command of the plurality of input/output commands.

11. The article of manufacture of claim 10, wherein said information comprises at least one of an indication of where execution of the input/output command was interrupted, and an indication of an amount of data not transferred for one or more input/output commands of the plurality of input/output commands.

12. The article of manufacture of claim 8, further comprising:

determine logic to determine by the control unit measurement data associated with execution of the plurality of input/output commands; and

provide logic to provide, by the control unit, the measurement data in a status control block specified by the transport control word, wherein said determining and providing by the control unit relieve the input/output communications adapter of having to infer or determine the measurement data.

13. The article of manufacture of claim 12, wherein the measurement data comprises at least one of a queue time parameter specifying an amount of time the control unit had an input/output operation on its queue with an exchange open to the input/output communications adapter, and a defer time parameter specifying an amount of time the control unit waited for data, with the exchange open to the input/output communications adapter because of a control unit data cache miss.

14. The article of manufacture of claim 12, wherein the measurement data comprises a control unit active time specifying the time the control unit is active executing the transport control word.