Central processing unit measurement facility

• US 7,827,321 B2
• Filed: 10/02/2008
• Issued: 11/02/2010
• Est. Priority Date: 10/02/2008
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Heller, Lisa Cranton, Bartik, Jane H., West, Patrick M. Jr., Osisek, Damian L., Schmidt, Donald W., Yeh, Phil C.
• Primary Examiner(s): Tsai; Henry
• Assistant Examiner(s): Tseng; Cheng-Yuan
• Application Number:
  US12/244,300
• Publication Number:
  US 20100088444A1
• Time in Patent Office: 761 Days
• Field of Search: None
• US Class Current: 710/5
• CPC Class Codes: G06F 12/06 Addressing a physical block of locations, e.g. base addressing, module addressing, memory dedication G06F12/08 takes precedence
• CPC Class Codes: G06F 12/0802 Addressing of a memory level in which the access to the desired data or data block requires associative addressing means, e.g. caches
• CPC Class Codes: G06F 13/24 using interrupt G06F13/32 takes precedence
• CPC Class Codes: G06F 2212/461 Sector or disk block
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• CPC Class Codes: G06F 3/0656 Data buffering arrangements
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: G06F 9/30145 Instruction analysis, e.g. decoding, instruction word fields

Abstract

A measurement sampling facility takes snapshots of the central processing unit (CPU) on which it is executing at specified sampling intervals to collect data relating to tasks executing on the CPU. The collected data is stored in a buffer, and at selected times, an interrupt is provided to remove data from the buffer to enable reuse thereof. The interrupt is not taken after each sample, but in sufficient time to remove the data and minimize data loss.

Claims

1. A computer program product to facilitate managing a collection of data within a processing environment, the computer program product comprising:

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

storing in a data block of a buffer data relating to execution of one or more tasks of the processing environment, wherein the storing is performed at a plurality of specified intervals, in which a plurality of stores to the data block are performed;

attempting another store of data to the data block for another specified interval, wherein it is determined that the data block has insufficient space for the another store;

determining whether an alert indicator is set for the data block, in response to the determining that the data block has insufficient space;

indicating an interrupt is to be performed at a specified time, in response to the determining indicating the alert indicator is set; and

storing the data of the another specified interval in another data block of the buffer.

2. The computer program product of claim 1, wherein the alert indicator is stored in the data block.

3. The computer program product of claim 2, wherein the data block comprises a plurality of data entries and a trailer entry, and wherein each store to the data block is to a different data entry of the plurality of data entries, and wherein the trailer entry includes the alert indicator.

4. The computer program product of claim 3, wherein contents of a data entry address register are used to select the data entry to be stored into, said contents of the data entry address register being updated in response to storing the data.

5. The computer program product of claim 3, further comprising setting a block full indicator in the trailer entry of the data block, in response to determining the data block has insufficient space.

6. The computer program product of claim 1, wherein the data block is pointed to by an entry in a sample data block table, which is selected based on contents of a table entry address register.

7. The computer program product of claim 1, further comprising performing the interrupt, in response to completing processing associated with storing the data of the another specified interval.

8. The computer program product of claim 7, further comprising, in response to performing the interrupt:

reading data out of the buffer and storing the data on at least one storage medium;

resetting a block full indicator set in response to determining there was insufficient space in the data block; and

re-establishing one or more alert indicators for the buffer.

9. The computer program product of claim 1, further comprising obtaining a request for data sampling to be performed, the data sampling to provide the data to be stored, wherein the request indicates a type of data sampling, said type comprising basic sampling, diagnostic sampling or a combination of basic sampling and diagnostic sampling.

10. The computer program product of claim 9, wherein the data sampling is controlled by a plurality of controls, said plurality of controls being set in one or more control registers by a Set Sampling Controls instruction executed by a control program of the processing environment.

11. The computer program product of claim 9, wherein information associated with the data sampling is obtained by executing a Query Sampling Information instruction by a control program of the processing environment.

12. The computer program product of claim 1, wherein the storing of data relating to execution of a task of the plurality of tasks comprises storing an identifier of the task with the data.

13. The computer program product of claim 1, further comprising:

determining a size of the buffer to be created, wherein the determining is based on at least one of an amount of memory to be used, desired interrupt frequency sampling interval and number of processors participating; and

creating the buffer of the determined size.

14. A computer-implemented method of managing a collection of data within a processing environment, said computer-implemented method comprising:

storing in a data block of a buffer data relating to execution of one or more tasks of the processing environment, wherein the storing is performed at a plurality of specified intervals, in which a plurality of stores to the data block are performed;

attempting another store of data to the data block for another specified interval, wherein it is determined that the data block has insufficient space for the another store;

determining whether an alert indicator is set for the data block, in response to the determining that the data block has insufficient space;

indicating an interrupt is to be performed at a specified time, in response to the determining indicating the alert indicator is set; and

storing the data of the another specified interval in another data block of the buffer.

15. The computer-implemented method of claim 14, further comprising performing the interrupt, in response to completing processing associated with storing the data of the another specified interval.

16. A computer system for managing a collection of data within a processing environment, said computer system comprising:

a memory having a buffer, said buffer comprising a plurality of data block tables, each data block table of the plurality of data block tables comprising a plurality of block link entries and a table link entry, each block link entry indicating a data entry of a data block of the buffer, and the table link entry indicating another table of the plurality of data block tables, the data block comprising a plurality of data entries and a trailer entry, the trailer entry including an alert indicator specifying whether an alert has been set for the data block; and

a processor in communications with the memory, wherein the computer system is performing a method comprising;

storing in the data block data relating to execution of one or more tasks of the processing environment, wherein the storing is performed at a plurality of specified intervals, in which a plurality of stores to the data block are performed;

attempting another store of data to the data block for another specified interval, wherein it is determined that the data block has insufficient space for the another store;

determining whether the alert indicator is set for the data block, in response to the determining that the data block has insufficient space;

indicating an interrupt is to be performed at a specified time, in response to the alert indicator being set; and

storing the data of the another specified interval in another data block of the buffer.

17. The computer system of claim 16, further comprising a plurality of control registers employed in controlling at least one of collecting the data to be stored and storing the data in the buffer.

18. The computer system of claim 16, further comprising performing the interrupt, in response to completing processing associated with storing the data of the another specified interval.

19. The computer system of claim 18, further comprising, in response to performing the interrupt:

reading data out of the buffer and storing the data on at least one storage medium;

resetting a block full indicator set in response to determining there was insufficient space in the data block; and

re-establishing one or more alert indicators for the buffer.

20. The computer system of claim 16, further comprising obtaining a request for data sampling to be performed, the data sampling to provide the data to be stored, wherein the request indicates a type of data sampling, said type comprising basic sampling, diagnostic sampling or a combination of basic sampling and diagnostic sampling.