Emulation of Extended Input/Output Measurement Block Facilities

• US 20080103754A1
• Filed: 12/28/2007
• Published: 05/01/2008
• Est. Priority Date: 05/12/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Carlson, Scott, Trotter, John, Dyck, Greg, Riedy, Dale, Oakes, Kenneth, Rooney, William, Lu, Tan, Yudenfriend, Harry, Wyman, Leslie
• Granted Patent: US 7,600,053 B2
• Time in Patent Office: Days
• US Class Current: 703/25
• 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

An Extended Input/output (I/O) measurement block facility is emulated. The facility provides for the collection of relevant I/O measurement data, and the storing for later efficient retrieval of that data in an extended measurement block. The stored data relates to the performance of an I/O subchannel.

Claims

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

emulating the execution of a modify subchannel instruction, in the emulated execution storing a measurement block address for 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 an 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;

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

2. The method according to claim 1, wherein the measurement block address comprises an address of storage of a 64 byte measurement block of the subchannel.

3. The method of claim 1, in which the step of obtaining measurement data is performed by an emulation routine.

4. The method of claim 1, in which the step of storing the obtained measurement data is performed by an emulation routine.

5. A computer program product for obtaining a bloc of 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;

emulating the execution of a modify subchannel instruction, in the emulated execution storing a measurement block address for 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 an 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;

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

6. The computer program product according to claim 5, wherein the measurement block consists of any one of 32 bytes or 64 bytes.

7. The computer program product according to claim 5, wherein the measurement block further comprises at least one of 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 or an initial command response time field.

8. The computer program product according to claim 5, wherein the subchannel comprises internal storage.

9. The computer program product according to claim 5, wherein the subchannel is a z/Architecture subchannel.

10. The method according to claim 5, wherein the measurement block address comprises an address of storage of a 64 byte measurement block of the subchannel.

11. The computer program product of claim 5, wherein the step of obtaining measurement data is performed by an emulation routine.

12. The computer program product of claim 5, wherein the step of storing the obtained measurement data is performed by an emulation routine.

13. A system for obtaining a bloc of 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;

emulating the execution of a modify subchannel instruction, the emulated execution storing a measurement block address for 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 an 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;

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

14. the system according to claim 13, wherein the measurement block consists of any one of 32 bytes or 64 bytes.

15. The system according to claim 13, wherein the measurement block further comprises at least one of 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 or an initial command response time field.

16. The system according to claim 13, wherein the subchannel comprises internal storage.

17. The system according to claim 13, wherein the subchannel is a z/Architecture subchannel.

18. The method according to claim 13, wherein the measurement block address comprises an address of storage of a 64 byte measurement block of the subchannel.

19. The system of claim 13, wherein the step of obtaining measurement data is performed by an emulation routine.

20. The system of claim 13, wherein the step of storing the obtained measurement data is performed by an emulation routine.