Sampling with sample pacing

• US 8,799,872 B2
• Filed: 06/27/2010
• Issued: 08/05/2014
• Est. Priority Date: 06/27/2010
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Levine, Frank E.
• Primary Examiner(s): DENG, ANNA CHEN
• Application Number:
  US12/824,217
• Publication Number:
  US 20110320173A1
• Time in Patent Office: 1,500 Days
• Field of Search: 717128-131
• US Class Current: 717/130
• CPC Class Codes: G06F 11/3476 Data logging G06F11/14, G06F11/2205 take precedence
• CPC Class Codes: G06F 2201/86 Event-based monitoring

Abstract

A plurality of samples is generated in a computer to profile and record a plurality of events associated with the computer. For each of the plurality of samples, a plurality of partial samples is accumulated prior to occurrence of each of the plurality of events. In addition, a processor may process a current sample of the plurality of samples in response to (i) a completion of a previous sample of the plurality of samples and (ii) a predetermined threshold quantity of partial samples being accumulated. Embodiments of the invention include methods, systems and computer program products.

Claims

1. A computer program product for sampling, the computer program product comprising:

a computer readable storage medium having computer readable program code embodied therewith, the computer readable storage medium is not a computer readable signal medium, the computer readable program code comprising;

computer readable program code to set an affinity of a target thread such that the target thread runs on a current processor without being able to migrate to a different processor;

in response to setting the affinity, computer readable program code to generate a plurality of samples in the computer system to profile and record a plurality of events associated with the target thread; and

computer readable program code to accumulate, for each of the plurality of samples, a plurality of partial samples prior to occurrence of each of the plurality of events; and

computer readable program code to process a current sample of the plurality of samples in response to (i) completing processing of a previous sample of the plurality of samples and (ii) an accumulated quantity of the pluralities of partial samples exceeding a predetermined threshold quantity.

2. The computer program product of claim 1, wherein each of the plurality of events is based on predetermined events.

3. The computer program product of claim 2, wherein the predetermined events are time based.

4. The computer program product of claim 1, wherein the predetermined events are based on interrupts.

5. The computer program product of claim 1, further comprising computer readable program code to utilize a plurality of predetermined previous sample rates.

6. The computer program product of claim 5, further comprising computer readable program code to determine a predetermined current sample rate for the current sample by increasing the previous sample rate by a factor such that the predetermined current sample rate is greater than the predetermined previous sample rate, the predetermined threshold quantity being the factor.

7. The computer program product of claim 1, further comprising computer readable program code to generate process statistics that include busy time.

8. The computer program product of claim 1, further comprising computer readable program code to write a profiling trace record in response to a predetermined number of interrupts having occurred since a last time that the profiling trace record was written, wherein the predetermined threshold quantity is different from the predetermined number of interrupts.

9. A method comprising:

setting an affinity of a target thread such that the target thread runs on a current processor without being able to migrate to a different processor;

in response to setting the affinity, generating a plurality of samples in a computer system to profile and record a plurality of events associated with the target thread; and

accumulating, for each of the plurality of samples, a plurality of partial samples prior to occurrence of each of the plurality of events;

processing a current sample of the plurality of samples in response to (i) completing processing of a previous sample of the plurality of samples and (ii) an accumulated quantity of the pluralities of partial samples exceeding a predetermined threshold quantity.

10. The method of claim 9, wherein each of the plurality of events is based on predetermined events.

11. The method of claim 10, wherein the predetermined events are time based.

12. The method of claim 9, wherein the predetermined events are based on interrupts.

13. The method of claim 9, wherein a plurality of predetermined previous sample rates is utilized.

14. The method of claim 13, wherein the current sample has a predetermined current sample rate that is determined by increasing the previous sample rate by a factor such that the predetermined current sample rate is greater than the predetermined previous sample rate, the predetermined threshold quantity being the factor.

15. The method of claim 14, wherein the computer is further caused to generate process statistics that include busy time.

16. The method of claim 9, further comprising:

writing a profiling trace record in response to a predetermined number of interrupts having occurred since a last time that the profiling trace record was written, wherein the predetermined threshold quantity is different from the predetermined number of interrupts.

17. A system comprising:

a processor; and

a data storage device coupled to the processor, wherein the data storage device stores program code, and wherein the processor is configured to execute the program code to perform operations, wherein the operations comprise;

setting an affinity of a target thread such that the target thread runs on a current processor without being able to migrate to a different processor;

in response to setting the affinity, generating a plurality of samples in a computer system to profile and record the a plurality of events associated with the target thread;

accumulating, for each of the plurality of samples, a plurality of partial samples prior to occurrence of each of the plurality of events; and

processing a current sample of the plurality of samples in response to (i) completing processing of a previous sample of the plurality of samples and (ii) an accumulated quantity of the pluralities of partial samples exceeding a predetermined threshold quantity.

18. The system of claim 17, wherein each of the plurality of events is based on predetermined events.

19. The system of claim 18, wherein the predetermined events are time based.

20. The system of claim 17, wherein the predetermined events are based on interrupts.

21. The system of claim 17, wherein the previous sample has a predetermined previous sample rate.

22. The system of claim 21, wherein the current sample has a predetermined current sample rate that is determined by increasing the previous sample rate by a factor such that the predetermined current sample rate is greater than the predetermined previous sample rate.

23. The system of claim 22, wherein the data storage device is a memory.

24. The system of claim 17, wherein the process writes a profiling trace record in response to a predetermined number of interrupts having occurred since a last time that the profiling trace record was written, wherein the predetermined threshold quantity is different from the predetermined number of interrupts.

25. A computer program product for sampling, the computer program product comprising:

a computer readable storage medium having computer readable program code embodied therewith, the computer readable storage medium is not a computer readable signal medium, the computer readable program code comprising;

computer readable program code to set an affinity of a target thread such that the target thread runs on a current processor without being able to migrate to a different processor;

computer readable program code to, in response to setting the affinity, generate a plurality of samples to profile and record a plurality of events for the target thread;

computer readable program code to accumulate, for each of the plurality of samples, a plurality of partial samples prior to occurrence of each of the plurality of events; and

computer readable program code to process, a current sample of the plurality of samples in response to (i) a completion of a previous sample of the plurality of samples and (ii) a predetermined threshold quantity of partial samples being accumulated, the previous sample having a predetermined previous sample rate, the current sample having a predetermined current sample rate that is determined by multiplying the previous sample rate by a factor such that the predetermined current sample rate is greater than the predetermined previous sample rate.

26. The computer program product of claim 25, wherein the event is based on a predetermined event.

27. The computer program product of claim 26, wherein the predetermined event is time based.

28. The computer program product of claim 25, wherein the event is based on an interrupt.