Channel measurement method and means

• US 5,265,240 A
• Filed: 07/24/1992
• Issued: 11/23/1993
• Est. Priority Date: 07/24/1992
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Wyman, Leslie W., Oakes, Kenneth J., Galbraith, Robert E., Glassen, Steven G., Marron, Assaf, Stucki, David E.
• Primary Examiner(s): Shaw, Dale M.
• Assistant Examiner(s): Meky, Moustafa M.
• Application Number:
  US07/898,623
• Time in Patent Office: 487 Days
• Field of Search: 395/275, 395/650, 395/550, 395/725, 364/265.5, 364/268.7, 364/270.6, 364/927.94, 364/927.99, 371/16.5, 371/19, 371/20.1
• US Class Current: 710/15
• CPC Class Codes: G06F 11/3419 by assessing time
• CPC Class Codes: G06F 11/3485 for I/O devices
• CPC Class Codes: G06F 11/349 for interfaces, buses

Abstract

Provides a method for measuring the busy utilization time for I/O channel used by any of plural operating systems (OSs) in a CEC. The measured utilization time for any OS excludes the time shared channels are utilized by other OSs during a measurement period. A channel measurement facility (CMF) is provided in the I/O subsystem hardware and microcode for each of the OSs in the I/O subsystem. The CMF is logically constructed because it uses only a small portion of I/O resources already existing in a CEC by adding microcode to control these resources to perform the time measurement function. The resources for a logical CMF including the partial use of: an I/O processor to store identifiers of an assigned OS, the partial use of channel processors controlling channels selected by the assigned OS during a measurement period, the local storage of each I/O processor, and OS storage needed for communicating the measurement data from the CMF to the OS. Any CPU can control a measurement by issuing "set channel measurement" instructions for starting and stopping a measurement performed asynchronously by the CMF to release the CPU for other independent CPU operations during a measurement period. The instruction can also be used to test the status of any CMF.

Claims

1. A means for measuring channel use time, comprising:

a computer electronic complex (CEC) having an I/O channel subsystem supporting I/O channels shareable by a plurality of operating systems (OSs) associated with different resource partitions in the CEC including a plurality of CPUs, and each partition having an assigned portion of a CEC main storage (MS) used by the associated OS;

a plurality of channel processors provided for respectively controlling I/O channels in an I/O channel subsystem of the CEC, each channel processor sensing an amount of continuous busy time for each channel as a time segment of measurement for the channel, means for summing the time segments for each channel and recording the sum in a channel accumulation entry in a local storage of the channel, and recording a time stamp indicating a time for the occurrence of the end of the last time segment provided to the summing means;

a plurality of channel measurement facilities (CMFs) provided for the I/O channel subsystem of the CEC, the CMFs associated with the OSs to make measurements of utilization of the I/O channels by respective OS;

means for periodically transferring the content of the channel accumulation entries and the time stamp entry from the local storages of all channel processors to corresponding entries in the CMFs to obtain a collection of entries in each associated CMF for all channels used by the associated OS, the contents of the entries in each CMF representing the accumulated utilization time and time stamps from a last resetting of the contents of all entries in the CMF; and

a CPU executing a CMF instruction for any OS to start an associated CMF, the associated CMF having all entries reset by a start command issued by the CMF instruction to start a measurement period from the time of execution of the CMF instruction, the CPU executing a CMF stop instruction to stop the measurement period after which the content of the associated CMF contains a measurement of channel utilization by the OS.

2. A means for measuring channel use time as defined in claim 1, further comprising:

an identified CMF being the CMF associated with the OS executing the CMF instruction and being identified by an OS identifier (IID).

3. A means for measuring channel use time as defined in claim 2, further comprising:

an identified CMF being a CMF other than the CMF associated with the OS executing the CMF instruction.

4. A means for measuring channel use time as defined in claim 1, further comprising:

a CPU executing a CMF instruction for any OS to test status of an identified CMF, means in the I/O processor for recording the identifier for each OS executing a CMF instruction to an identified CMF, means in the I/O processor for responding to the OS by indicating the status of the identified CMF in a command response block (CRPB) located in main storage at a location specified by the CMF instruction.

5. A method of measuring channel use time by a plurality of operating systems (OSs) sharing plural channels in a computer electronic complex (CEC), comprising the steps of:

structuring a logical channel measurement facility (CMF) for each of the plural OSs in the CEC;

each of the OSs operating in a different logical resource partition in the CEC and having an assigned OS identifier (IID);

measuring by each channel processor in the CEC of each channel time segment used by the channel processor, each time segment being time measured during continuous operation of a channel processor for an OS,

accumulating for each channel processor all time segments used by the channel processor for each OS over a measurement period;

transferring accumulated time segments for each OS from each channel processor to each of a plurality of channel measurement facilities (CMFs) in the CEC for enabling each OS to access accumulated time segments for each channel processor used by the OS over a measurement period; and

independently controlling each of the plural CMFs by a hypervisor in the CEC issuing a command designating an IID assigned to the CMF for controlling the CMF, and a CMF not being changed by a commanded operation performed by any other CMF.

6. A method of measuring channel use time as defined in claim 5, further comprising the step of:

stopping the operation of any of the plurality of CMFs by the hypervisor issuing a stop command designating an IID assigned to the CMF, the stoppage of the CMF operation occurring regardless of the current operational state of the CMF without affecting the operation of any other CMF in the system.

7. A method of measuring channel use time as defined in claim 5, further comprising the step of:

resetting a state of any of the plurality of CMFs by the hypervisor issuing a reset command designating an IID assigned to the CMF, the CMF being reset regardless of the current state of the CMF and without affecting the operation of any other CMF in the system.

8. A method of measuring channel use time as defined in claim 5, further comprising the step of:

issuing a stop or reset command to any CMF in the CEC by either a microcode hypervisor or a software hypervisor to stop or reset, respectively, the state of the CMF without affecting the operation of any other CMF in the CEC.

9. A method of measuring channel use time as defined in claim 5, further comprising the step of:

executing a CMF instruction by a central processor (CPU) in the CEC for issuing a start command to activate the CMF to start a measurement period in which the CMF operates asynchronously, and the CPU being released from executing other instructions upon completion of the start command.

10. A method of measuring channel use time as defined in claim 9, further comprising the step of:

executing a CMF instruction by a central processor (CPU) in the CEC for issuing a stop command to deactivate the CMF to end the measurement period.

11. A method of measuring channel use time as defined in claim 5, further comprising the step of:

executing a CMF instruction by a central processor (CPU) in the CEC for issuing a test command to test the operating status of the CMF.

12. A method of measuring channel use time as defined in claim 11, further comprising the step of:

executing the test command to determine if the CMF is in an active state, a stopped state, or an error state.

13. A method of measuring channel use time as defined in claim 5, further comprising the step of:

dedicating an I/O channel processor for controlling each I/O channel; and

continuously measuring a current time segment while each channel processor is operating, during which a busy state exists for the channel processor.

14. A method of measuring channel use time as defined in claim 13, further comprising the step of:

executing a CMF start command only if a prior executed CMF test command indicates the CMF is in a stopped state and not in an error state.

15. A method of measuring channel use time as defined in claim 5, further comprising the step of:

sharing the CMFs by the channel processors in the CEC by accumulating time segments in each CMF for respective channel processors used by an OS associated with the CMF during a measurement period.

16. A method of measuring channel use time as defined in claim 5, further comprising the steps of:

identifying a CMF in a measurement command request control block (CRQB) located by a CMF instruction executed by an OS having the same identifier as assigned to the CMF; and

responding by the CMF to the OS executing the CMF instruction by providing measurements of channel utilization for the OS assigned to the CMF.

17. A method of measuring channel use time as defined in claim 16, further comprising the steps of:

identifying a CMF to perform a measurement command for a measurement command request control block (CRQB) located by a CMF instruction executed by an OS having a different identifier from the identifier assigned to the CMF; and

responding by the CMF to the control program executing the CMF instruction by providing measurements of I/O channel utilization for the OS assigned to the CMF.

18. A method of measuring channel use time as defined in claim 17, further comprising the steps of:

providing an I/O processor to store the identifier of the OS issuing the measurement command to enable the I/O channel subsystem to respond to the OS issuing the command.

19. A method of measuring channel use time as defined in claim 18, further comprising the steps of:

providing an I/O processor to identify and access the CMF identified by the CRQB of the instruction executed by the OS.

20. A method of measuring channel use time as defined in claim 19, further comprising the steps of:

executing each CMF instruction in a central processor (CPU) of the CEC; and

releasing the CPU for executing other CPU instructions independently of CMF measurement operations.

21. A method of measuring channel use time as defined in claim 20, further comprising the step of:

invoking by the I/O processor of each channel processor used by an identified CMF for the associated OS.

22. A method of measuring channel use time as defined in claim 21, further comprising the step of:

transferring each time segment of utilization time for each channel processor invoked by the I/O processor to an accumulation entry in a logical storage of the channel processor in which each transferred time segment is added to a previous value accumulated in the entry for providing accumulated channel time during a measurement period.

23. A method of measuring channel use time as defined in claim 22, further comprising the step of:

moving accumulated time segments from a local storage of each channel processor to a microcode storage entry for each channel processor in a collection of entries for each CMF from all channel processors in the CEC to generate a collection of all channel processor entries for all CMFs in the CEC to represent accumulated channel time for all channel processors for each CMF in the CEC.

24. A method of measuring channel use time as defined in claim 23, further comprising the step of:

periodically transferring accumulated time segments from the local storage of each channel processor to respective microcode storage entries for each of the CMFs in the CEC.

25. A method of measuring channel use time as defined in claim 24, further comprising the step of:

also periodically transferring the content of the respective microcode storage entries to channel entries in the CEC main storage assigned to the OSs executing CMF instructions to enable the OSs to access channel utilization time measured by accumulated time segments for each channel used by each OS.

26. A method of measuring channel use time as defined in claim 25, further comprising the steps of:

receiving by a channel measurement block (CMB) of respective microcode storage entries to perform the step of also periodically transferring entries in the CMB providing measured channel utilization time for all channel processors used by each OS in the CEC; and

locating the CMB by an address in the CRQB.

27. A method of measuring channel use time as defined in claim 5, further comprising the step of:

operating each CMF independently of other CMFs to enable independent channel utilization time measurements for utilized I/O channel processors selected on an OS basis, including only the proportionate time a shared channel is being used by a respective OS.

28. A method of measuring channel use time as defined in claim 5, further comprising the steps of:

sharing a plurality of I/O channel processors among the OSs; and

operating each CMF for an associated OS to measure the utilization time for shared I/O channel processors only while the channel processors are being used by the associated OS.

29. A method of measuring channel use time as defined in claim 5, further comprising the step of:

recording current clock values of a processor clock at a beginning time and an ending time of each time segment for each channel processor as time stamp entries for the channel processor.

30. A method of measuring channel use time as defined in claim 29, further comprising the step of:

accumulating time segments segment by subtracting the beginning time from the ending time, and adding the subtraction result to a current content of an accumulated utilization time field to obtain accumulated utilization time in an entry for the channel processor.

31. A method of measuring channel use time as defined in claim 30, further comprising the step of:

transferring a processor clock value as a time stamp into a clock register entry for each channel processor, and associated an OS identifier of an OS currently using the channel processor with the clock register entry.

32. A method of measuring channel use time as defined in claim 31, further comprising the step of:

periodically transferring the content of the time stamp from the clock register entry for each of plural channel processors to a corresponding channel processor entry in CMF storage for a CMF having an OS identifier equal to the OS identifier associated with the clock register entry, in which each CMF generates a collection of time stamps for all channel processors used by each CMF during a measurement period.

33. A method of measuring channel use time as defined in claim 32, further comprising the step of:

also periodically transferring the content of a collection of time stamps for each CMF from CMF storage to a storage accessible by each respective operating system executing a CMF instruction requesting measurements by the CMF.

34. A method of measuring channel use time as defined in claim 33, further comprising the steps of:

receiving by a channel measurement block (CMB) of respective microcode storage entries to perform the also periodically transferring step, for which entries in the CMB provides the time stamps for all channel processors in the CEC to respective OSs, and

locating the CMB by an address in the CRQB.

35. A method of measuring channel use time as defined in claim 34, further comprising the step of:

grouping entries in each CMF for the different channel processors to contain both measured channel utilization time and the time stamps as a measurement of I/O activity for an associated OS.