Adaptive and dynamic filtering of threaded programs

• US 20060150162A1
• Filed: 12/30/2004
• Published: 07/06/2006
• Est. Priority Date: 12/30/2004
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Mongkolsmai, Ekarat T., Shah, Sanjiv M., Armstrong, Douglas R.
• Granted Patent: US 7,703,094 B2
• Time in Patent Office: Days
• US Class Current: 717/131
• CPC Class Codes: G06F 11/3466 Performance evaluation by tracing or monitoring
• CPC Class Codes: G06F 11/3612 by runtime analysis performance monitoring G06F11/3466
• CPC Class Codes: G06F 2201/81 Threshold
• CPC Class Codes: G06F 2201/86 Event-based monitoring
• CPC Class Codes: G06F 2201/865 Monitoring of software

Abstract

A method and apparatus for adaptive and dynamic filtering of threaded programs. An embodiment of a method comprises analyzing the operation of a computer program, the computer program comprising a plurality of program threads; tracking overhead for the computer program; observing program events for the computer program; rationing overhead between program threads in inter-thread program events; and filtering program events based on a dynamic threshold.

Claims

1. A method comprising:

analyzing the operation of a computer application, the computer application comprising a first program thread and a second program thread;

recording overhead for the first program thread and the second program thread;

observing an event comprising the transfer of a signal from the second program thread to the first program thread; and

adjusting the overhead for the first program thread if the first program thread waits a time period before receiving the signal from the second program thread.

2. The method of claim 1, further comprising determining whether the overhead of the second thread minus the overhead of the first thread is greater than the wait time.

3. The method of claim 2, further comprising adding the wait time period to the overhead of the first program thread if the overhead of the second program thread minus the overhead of the first program thread is greater than the wait time period.

4. The method of claim 2, further comprising determining that the wait time period likely would not have occurred without the analysis of the computer application and ignoring the event if the overhead of the second program thread minus the overhead of the first program thread is greater than the wait time period.

5. The method of claim 2, further comprising adding the overhead of the second thread minus the overhead of the first thread to the overhead of the first thread if the overhead of the second program thread minus the overhead of the first thread is greater than zero.

6. The method of claim 2, further comprising making no change to the overhead of the first thread if the overhead of the second program thread minus the overhead of the first thread is not greater than zero.

7. The method of claim 1, further comprising establishing a threshold for analysis, the event not being observed if the overhead resulting from the event is below the threshold.

8. The method of claim 7, further comprising dynamically modifying the threshold.

9. The method of claim 8, wherein the threshold is modified based at least in part on a ratio of overhead time to user time during an interval.

10. The method of claim 8, wherein the threshold is modified based at least in part on a number of events that are observed during an interval.

11. A performance analyzer comprising:

an adaptive filter for a multithreaded program, the adaptive filter to determine the rationing of overhead between a plurality of program threads in program events; and

a dynamic filter for the multithreaded program, the dynamic filter to modify a threshold for collection of data based on the performance of the program.

12. The performance analyzer of claim 11, wherein the adaptive filter is to determine whether a program event may have occurred without the operation of the performance analyzer.

13. The performance analyzer of claim 12, wherein the adaptive filter is to ignore a program event if the program event likely would not have occurred without the operation of the performance analyzer.

14. The performance analyzer of claim 11, wherein the dynamic filter is to adjust the threshold based at least in part on the percentage of program events that are observed by the analyzer.

15. The performance analyzer of claim 14, wherein the dynamic filter is to adjust the threshold to observe more program events if the percentage of program events that are observed is below a level set by a program user.

16. The performance analyzer of claim 11, wherein the dynamic filter is to adjust the threshold based at least in part on a ratio of overhead time for the thread versus user time for the thread.

17. The performance analyzer of claim 16, wherein the dynamic filter is to adjust the threshold to observe fewer program events if the ratio is above a level set by a program user.

18. A system comprising:

a dynamic memory to store a multithreaded program, the program comprising a first program thread and a second program thread;

a processor to run the multithreaded program; and

an analysis tool to analyze the performance of the multithreaded program as run by the processor, the analysis tool comprising a first component to track overhead for program threads and a second component to determine which program events are to be observed by the analysis tool.

19. The system of claim 18, wherein the analysis tool does not track a program event if the program event likely would not occur without the operation of the analysis tool.

20. The system of claim 18, wherein the first component determines the rationing of overhead time between the first program thread and the second program thread in a program event comprising the second program thread sending a signal to the first program thread.

21. The system of claim 20, wherein the first component determines an overhead element to ration to the first program thread if the first program thread waits for a time period before receiving the signal from the second program thread.

22. The system of claim 21, wherein the overhead element rationed to the first program thread is equal to the waiting period if the difference between the overhead of the second thread and the overhead of the first thread is greater than the length of the waiting time period.

23. The system of claim 22, wherein the overhead element rationed to the first program thread is the difference between the overhead of the second thread and the overhead of the first thread if the difference between the overhead of the second thread and the overhead of the first thread is greater than zero.

24. The system of claim 23, wherein the overhead element rationed to the first program thread is zero if the difference between the overhead of the second thread and the overhead of the first thread is not greater than zero.

25. The system of claim 18, wherein the second component utilizes a threshold to determine which program events are to be observed by the analysis tool.

26. The system of claim 25, wherein the second component dynamically changes the threshold based at least in part on the amount of overhead time incurred.

27. The system of claim 25, wherein the second component dynamically changes the threshold based at least in part on the number of program events observed.

28. A machine-readable medium having stored thereon data representing sequences of instructions that, when executed by a processor, cause the processor to perform operations comprising:

analyzing the operation of a computer program, the computer program comprising a plurality of program threads;

tracking overhead for the computer program;

observing program events for the computer program;

rationing overhead between program threads in inter-thread program events; and

filtering program events based on a dynamic threshold.

29. The medium of claim 28, wherein the instructions further comprise instructions that, when executed by a processor, cause the processor to perform operations comprising determining which inter-thread events likely would not have occurred without analysis of the computer program.

30. The medium of claim 29, wherein the instructions further comprise instructions that, when executed by a processor, cause the processor to perform operations comprising filtering out inter-thread events that likely would not have occurred without analysis of the computer program.

31. The medium of claim 28, wherein the instructions further comprise instructions that, when executed by a processor, cause the processor to perform operations comprising modifying the threshold based at least in part on a ratio of overhead time to user time during a time interval.

32. The medium of claim 28, wherein the instructions further comprise instructions that, when executed by a processor, cause the processor to perform operations comprising modifying the threshold based at least in part on a number of events that are observed during a time interval.