Obtaining extended queue measurement data for a range of logical control unit queues

• US 7,516,248 B2
• Filed: 12/28/2007
• Issued: 04/07/2009
• Est. Priority Date: 05/12/2003
• Status: Expired due to Term

• 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.
• Primary Examiner(s): Chen; Alan S.
• Application Number:
  US11/965,916
• Publication Number:
  US 20080109580A1
• Time in Patent Office: 466 Days
• Field of Search: None
• US Class Current: 710/15
• 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 for channels attached to logical control unit queues is obtained related to a plurality of logical control unit queues. A store secondary queue measurement data instruction specifies a range of queues for which extended secondary measurement blocks derived from the I/O measurement data are stored at a memory address specified by the store secondary queue measurement data instruction.

Claims

1. A method for obtaining I/O measurement queue data in a computer system comprising Secondary Queues wherein a secondary queue is a queue of I/O requests that a channel subsystem has begun to process, but is unable to complete because of a busy condition in an I/O configuration, the method comprising:

obtaining measurement data, the 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;

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.

2. The method according to claim 1 wherein the command request block information specifying the range comprises a first queue number, a last queue number.

3. The method according to claim 1 wherein the command request block information comprises a length field, a command code, a multiple channel subsystem bit, a Multiple Image Facility (MIF) image ID, an extended I/O measurement block format, a format, a first queue number, a Channel SubSystem image IDentifier (CSSID), a last queue number and a last request.

4. The method according to claim 1, wherein each created extended secondary queue measurement block consists of any one of a queue valid indicator field, a queue out of range field, a queue count field, a queue number field, a summation of queue counts field, a summation of enqueues field, a summation of channel wait time field, a switch busy counts field, a control unit busy counts field, a success counts field, one or more control unit busy time fields, one or more initial command response time fields or one or more switch busy count summation fields.

5. The method according to claim 1 wherein each created extended secondary queue measurement block comprises a queue valid indicator field, a queue out of range field, a queue count field, a queue number field, a summation of queue counts field, a summation of enqueues field, a summation of channel wait time field, a switch busy counts field, a control unit busy counts field, a success counts field, one or more control unit busy time fields, one or more initial command response time fields and one or more switch busy count summation fields.

6. The method according to claim 1 wherein the storing the created one or more extended secondary measurement blocks step comprises the further step of storing a length field, a response code and a format at the memory address block specified by the store secondary queue measurement data instruction, the length field specifying the length of the memory address block.

7. The method according to claim 1 wherein the specified range of Secondary Queues—

is defined within a channel subsystem image, the channel subsystem image specified by an effective Channel SubSystem image IDentifier.

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

determining a number of the one or more secondary queue measurement blocks stored by performing the further steps of;

subtracting 8 bytes from size of the command response block; and

dividing the result of the subtracting step by the size of a secondary queue measurement block.

9. 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;

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.

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

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;

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.

11. A computer program product for obtaining I/O measurement queue data in a system comprising Secondary Queues wherein a secondary queue is a queue of I/O requests that a channel subsystem has begun to process, but is unable to complete because of a busy condition in an I/O configuration, 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;

obtaining measurement data, the 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;

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.

12. The computer program product according to claim 11 wherein the command request block information specifying the range comprises a first queue number, a last queue number.

13. The computer program product according to claim 11 wherein the command request block information comprises a length field, a command code, a multiple channel subsystem bit, a Multiple Image Facility (MIF) image ID, an extended I/O measurement block format, a format, a first queue number, a Channel SubSystem image IDentifier (CSSID), a last queue number and a last request.

14. The computer program product according to claim 11 wherein each created extended secondary queue measurement block consists of any one of a queue valid indicator field, a queue out of range field, a queue count field, a queue number field, a summation of queue counts field, a summation of enqueues field, a summation of channel wait time field, a switch busy counts field, a control unit busy counts field, a success counts field, one or more control unit busy time fields, one or more initial command response time fields or one or more switch busy count summation fields.

15. The computer program product according to claim 11 wherein each created extended secondary queue measurement block comprises a queue valid indicator field, a queue out of range field, a queue count field, a queue number field, a summation of queue counts field, a summation of enqueues field, a summation of channel wait time field, a switch busy counts field, a control unit busy counts field, a success counts field, one or more control unit busy time fields, one or more initial command response time fields and one or more switch busy count summation fields.

16. The computer program product according to claim 11 wherein the storing the created one or more extended secondary measurement blocks step comprises the further step of storing a length field, a response code and a format at the memory address block specified by the store secondary queue measurement data instruction, the length field specifying the length of the memory address block.

17. The computer program product according to claim 11 wherein the specified range of Secondary Queues—

is defined within a channel subsystem image, the channel subsystem image specified by an effective Channel SubSystem image IDentifier.

18. The computer program product according to claim 11 comprising the further steps of:

determining a number of the one or more secondary queue measurement blocks stored by performing the further steps of;

subtracting 8 bytes from size of the command response block; and

dividing the result of the subtracting step by the size of a secondary queue measurement block.

19. A system for obtaining I/O measurement queue data, the system comprising Secondary Queues wherein a secondary queue is a queue of I/O requests that a channel subsystem has begun to process, but is unable to complete because of a busy condition in an I/O configuration, 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;

obtaining measurement data, the 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;

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.

20. The system according to claim 19 wherein the command request block information specifying the range comprises a first queue number, a last queue number.

21. The system according to claim 19 wherein the command request block information comprises a length field, a command code, a multiple channel subsystem bit, a Multiple Image Facility (MIF) image ID, an extended I/O measurement block format, a format, a first queue number, a Channel SubSystem image IDentifier (CSSID), a last queue number and a last request.

22. The system according to claim 19 wherein each created extended secondary queue measurement block consists of any one of a queue valid indicator field, a queue out of range field, a queue count field, a queue number field, a summation of queue counts field, a summation of enqueues field, a summation of channel wait time field, a switch busy counts field, a control unit busy counts field, a success counts field, one or more control unit busy time fields, one or more initial command response time fields or one or more switch busy count summation fields.

23. The system according to claim 19 wherein each created extended secondary queue measurement block comprises a queue valid indicator field, a queue out of range field, a queue count field, a queue number field, a summation of queue counts field, a summation of enqueues field, a summation of channel wait time field, a switch busy counts field, a control unit busy counts field, a success counts field, one or more control unit busy time fields, one or more initial command response time fields and one or more switch busy count summation fields.

24. The system according to claim 19 wherein the storing the created one or more extended secondary measurement blocks step comprises the further step of storing a length field, a response code and a format at the memory address block specified by the store secondary queue measurement data instruction, the length field specifying the length of the memory address block.

25. The system according to claim 19 wherein the specified range of Secondary Queues is defined within a channel subsystem image, the channel subsystem image specified by an effective Channel SubSystem IDentifier.