Extended Input/Output Measurement Word Facility, and Emulation of that Facility

• US 20080103755A1
• 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: Roeney, William, Lu, Tan, Carlson, Scott, Trotter, John, Dyck, Greg, Yudenfriend, Harry, Riedy, Dale, Oakes, Kenneth, Wyman, Leslie
• Granted Patent: US 7,886,082 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 word facility is provided. Provision is made for emulation of the Extended I/O measurement word facility. The facility provides for storing measurement data associated with a single I/O operation in an extended measurement word associated with an I/O response block. In a further aspect, the stored data may have a resolution of approximately one-half microsecond.

Claims

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

indicating to a channel subsystem that an Extended I/O Measurement Word Facility is enabled;

storing measurement data associated with the single I/O operation in a subchannel of the channel subsystem;

signaling the completion of the single I/O operation;

executing a test subchannel instruction in response to detecting the signaling of completion of the I/O interruption, the test subchannel instruction designating the subchannel and an address of an I/O Response block, the execution comprising placing the measurement data associated with the single I/O operation in the Extended Measurement Word (EMW) associated with the I/O Response Block (IRB) based on a determination that the Extended I/O Measurement Word Facility is enabled.

2. The method of claim 1, in which the measurement data placed in the Extended Measurement Word comprises one or more of the following elements:

device connect time;

function pending time;

device disconnect time;

control unit queuing time;

device active only time;

device busy time; and

initial command response time.

3. The method of claim 1, in which the stored measurement data has a time resolution of approximately one-half microsecond.

4. The method of claim 1, in which the step of executing the test subchannel instruction is carried out by an emulator function.

5. The method of claim 4, in which the emulator function comprises a routine comprising machine instructions of a first processor architecture, the routine emulating instruction functionality of a second processor architecture.

6. The method of claim 1, in which one or more of the method steps are carried out by emulator functions.

7. The method of claim 6, in which the emulator functions each comprise a routine comprising machine instructions of a first processor architecture, the routine emulating functionality of a second processor architecture.

8. The method of claim 2, wherein the 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.

9. A system providing for the obtaining of measurement data associated with a single I/O operation without obtaining such measurement data both before and after the single I/O operation, the system comprising:

a central processor capable of executing machine instructions;

an operating system capable of executing on the central processor, the operating system comprising an I/O operation—

initiating machine instruction;

an indicator field indicating whether the system is enabled for handling a request for storing Extended Measurement Word data;

an instruction handling routine capable of handling a test subchannel instruction, the instruction handling routine executing on the central processor after the I/O operation completes and after, in response to the completion, a test subchannel instruction is issued, the instruction handling routine, based on the indicator field indicating that the system is enabled for handling a request for storing Extended Measurement Word data, storing measurement data associated with the I/O operation in an Extended Measurement Word (EMW) associated with an I/O Response Block (IRB).

10. The system of claim 9, in which the measurement data placed in the Extended Measurement Word comprises one or more of the following elements:

device connect time;

function pending time;

device disconnect time;

control unit queuing time;

device active only time;

device busy time; and

initial command response time.

11. The system of claim 10, wherein the 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.

12. The system of claim 9, in which the stored measurement data has a time resolution of approximately one-half microsecond.

13. The system of claim 9, in which the instruction handling routine is an emulation routine.

14. The system of claim 13, in which the emulation routine comprises machine instructions of a first processor architecture, the routine emulating instruction functionality of a second processor architecture.

15. A computer program product for obtaining measurement data associated with a single I/O operation without obtaining such measurement data both before and after such single I/O operation, the computer program product comprising:

a storage medium readable by a processor and storing instructions and data for execution by the processor for performing a method comprising;

indicating to a channel subsystem that an Extended I/O Measurement Word Facility is enabled;

storing measurement data associated with the single I/O operation in a subchannel of the channel subsystem;

signaling the completion of the single I/O operation;

executing a test subchannel instruction in response to detecting the signaling of completion of the I/O interruption, the test subchannel instruction designating the subchannel and an address of an I/O Response block, the execution comprising placing the measurement data associated with the single I/O operation in the Extended Measurement Word (EMW) associated with the I/O Response Block (IRB) based on a determination that the Extended I/O Measurement Word Facility is enabled.

16. The computer program product of claim 15, in which the measurement data placed in the Extended Measurement Word comprises one or more of the following elements:

device connect time;

function pending time;

device disconnect time;

control unit queuing time;

device active only time;

device busy time; and

initial command response time.

17. The computer program product of claim 16, wherein the 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.

18. The computer program product of claim 15, in which the stored measurement data has a time resolution of approximately one-half microsecond.

19. The computer program product of claim 15, in which the step of executing a test subchannel instruction is carried out by an emulator function.

20. The computer program product of claim 19, in which the emulator function comprises an emulator routine comprising machine instructions of a first processor architecture, the routine emulating instruction functionality of a second processor architecture.

21. The computer program product of claim 15, in which one or more of the steps are carried out by an emulator function.

22. The computer program product of claim 21, in which the emulator function comprises an emulator routine comprising machine instructions of a first processor architecture, the routine emulating functionality of a second processor architecture.