Gathering I/O measurement data during an I/O operation process

• US 20050204069A1
• Filed: 05/11/2005
• Published: 09/15/2005
• Est. Priority Date: 05/12/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Yudenfriend, Harry M., Wyman, Leslie W., Riedy, Dale F. Jr., Carlson, Scott M., Lu, Tan, Dyck, Greg A., Rooney, William J., Trotter, John S., Oakes, Kenneth J.
• Granted Patent: US 7,174,274 B2
• Time in Patent Office: Days
• US Class Current: 710/1
• CPC Class Codes: G06F 11/3041 where the computing system component is an input/output interface interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units G06F13/00
• CPC Class Codes: G06F 11/3065 Monitoring arrangements determined by the means or processing involved in reporting the monitored data error or fault reporting or logging G06F11/0766
• CPC Class Codes: G06F 11/3419 by assessing time
• CPC Class Codes: G06F 11/3485 for I/O devices
• CPC Class Codes: G06F 13/105 where the programme performs an input/output emulation function
• CPC Class Codes: G06F 13/124 where hardware is a sequential transfer control unit, e.g. microprocessor, peripheral processor or state-machine
• CPC Class Codes: G06F 13/24 using interrupt G06F13/32 takes precedence
• CPC Class Codes: G06F 2201/88 Monitoring involving counting
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• CPC Class Codes: G06F 30/367 Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods
• CPC Class Codes: G06F 9/30003 Arrangements for executing specific machine instructions
• CPC Class Codes: H04L 1/0073 Special arrangements for feedback channel

Abstract

I/O measurement data associated with the performance of an I/O operation process is gathered during the I/O process. The I/O measurement data is saved in an IRB memory location specified by a test subchannel instruction. An I/O interrupt signals the completion of the I/O operation process.

Claims

1. A method for obtaining I/O measurement data, the method comprising:

in response to executing a start subchannel instruction, starting an I/O operation process;

obtaining I/O measurement data associated with the performance of the I/O operation process during the I/O operation process;

saving the obtained I/O measurement data;

generating an I/O interrupt at the completion of the I/O operation process; and

in response to executing a test subchannel instruction, storing the obtained I/O measurement data in an IRB memory location specified by the test subchannel instruction.

2. The method according to claim 1 wherein the stored measurement data comprises a device connect time field, a function pending time field, a device disconnect time field, a control unit queuing time field, a device active only time field, a device busy time field and an initial command response time field.

3. The method according to claim 1 wherein I/O operation is associated with a subchannel wherein the subchannel provides a logical appearance of an I/O device to a program, the subchannel is associated with an I/O device and provides information concerning the associated I/O device and I/O operations and functions involving the associated I/O device.

4. The method according to claim 1 wherein I/O operation is associated with a subchannel wherein the subchannel comprises internal storage.

5. The method according to claim 1 wherein the saving the obtained I/O measurement data step saves the data in an internal control block with a subchannel.

6. The method according to claim 1 wherein the I/O operation is associated with a z/Architecture subchannel.

7. The method according to claim 1 comprising the further steps of:

in response to executing a modify subchannel instruction, storing a measurement block address of a subchannel of a channel subsystem, the measurement block address directly specifying a location in memory of a measurement block assigned to the subchannel;

obtaining measurement data the measurement data related to the performance of the I/O operation of the subchannel, the measurement data comprising device busy time, wherein device busy time is the sum of time intervals when a subchannel is device busy during an attempt to initiate any one of a start function or a resume function at the subchannel; and

storing the obtained measurement data comprising a device busy time in the measurement block specified by the measurement block address, the measurement block comprising a device busy time field.

8. The method according to claim 1 comprising the further steps of:

obtaining measurement data, measurement data related to a plurality of secondary queues (logical control unit queues) of a channel subsystem, the measurement data comprising queuing statistics and measurement information for one or more channels attached to the plurality of secondary queues;

executing a store secondary queue measurement data instruction having a command request block, the command request block comprising information specifying a range of secondary queues of the plurality of secondary queues;

for each secondary queue of the specified range of secondary queues, creating one or more extended secondary measurement blocks, the extended secondary measurement blocks comprising the measurement data; and

in response to executing the store secondary queue measurement data instruction, storing the created one or more extended secondary measurement blocks at a memory address block directly specified by the store secondary queue measurement data instruction.

9. A computer program product for obtaining I/O measurement data, the computer program product comprising:

a storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising;

in response to executing a start subchannel instruction, starting an I/O operation process;

obtaining I/O measurement data associated with the performance of the I/O operation process during the I/O operation process;

saving the obtained I/O measurement data;

generating an I/O interrupt at the completion of the I/O operation process; and

in response to executing a test subchannel instruction, storing the obtained I/O measurement data in an IRB memory location specified by the test subchannel instruction.

10. The computer program product according to claim 9 wherein the stored measurement data comprises a device connect time field, a function pending time field, a device disconnect time field, a control unit queuing time field, a device active only time field, a device busy time field and an initial command response time field.

11. The computer program product according to claim 9 wherein I/O operation is associated with a subchannel wherein the subchannel provides a logical appearance of an I/O device to a program, the subchannel is associated with an I/O device and provides information concerning the associated I/O device and I/O operations and functions involving the associated I/O device.

12. The computer program product according to claim 9 wherein I/O operation is associated with a subchannel wherein the subchannel comprises internal storage.

13. The computer program product according to claim 9 wherein the saving the obtained I/O measurement data step saves the data in an internal control block with a subchannel.

14. The computer program product according to claim 9 wherein the I/O operation is associated with a z/Architecture subchannel.

15. A system for obtaining I/O measurement data, the system comprising:

a memory;

a computer system in communication with the memory, The computer system comprising an instruction fetching unit for fetching instructions from memory and one or more execution units for executing fetched instructions;

wherein the computer system includes instructions to execute a method comprising;

in response to executing a start subchannel instruction, starting an I/O operation process;

obtaining I/O measurement data associated with the performance of the I/O operation process during the I/O operation process;

saving the obtained I/O measurement data;

generating an I/O interrupt at the completion of the I/O operation process; and

in response to executing a test subchannel instruction, storing the obtained I/O measurement data in an IRB memory location specified by the test subchannel instruction.

16. The system according to claim 15 wherein the stored measurement data comprises a device connect time field, a function pending time field, a device disconnect time field, a control unit queuing time field, a device active only time field, a device busy time field and an initial command response time field.

17. The system according to claim 15 wherein I/O operation is associated with a subchannel wherein the subchannel provides a logical appearance of an I/O device to a program, the subchannel is associated with an I/O device and provides information concerning the associated I/O device and I/O operations and functions involving the associated I/O device.

18. The system according to claim 15 wherein I/O operation is associated with a subchannel wherein the subchannel comprises internal storage.

19. The system according to claim 15 wherein the saving the obtained I/O measurement data step saves the data in an internal control block with a subchannel.

20. The system according to claim 15 wherein the I/O operation is associated with an IBM z/Architecture subchannel.