MUTEX PROFILING BASED ON WAITING ANALYTICS

• US 20180217878A1
• Filed: 01/30/2017
• Published: 08/02/2018
• Est. Priority Date: 01/30/2017
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Loh, Eugene Ying
• Granted Patent: US 10,417,057 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms

Abstract

Techniques are described herein for profiling mutual exclusion locks. In one or more embodiments, a performance profiler identifies a first thread executing an activity within a parallel processing environment. The performance profiler identifies a set of one or more mutual-exclusion locks held by the first thread while the activity is being executed and determines the total number of threads waiting for at least one of the set of mutual-exclusion locks held by the first thread. The performance profiler then determines a total cost associated with execution of the activity based at least on the total number of threads waiting for at least one of the set of mutual-exclusion locks held by the first thread during execution of the activity. In one or more embodiments, the total cost is obtained by multiplying a raw cost with the number of threads waiting.

Claims

1. A non-transitory computer-readable medium comprising instructions which, when executed by one or more hardware processors, causes performance of operations comprising:

identifying a first thread executing an activity;

determining a set of one or more mutual-exclusion locks held by the first thread while the activity is being executed;

determining a total number of threads waiting for at least one of the set of mutual-exclusion locks held by the first thread during execution of the activity; and

determining a total cost associated with execution of the activity based at least on the total number of threads waiting for at least one of the set of mutual-exclusion locks held by the first thread during execution of the activity.

2. The non-transitory computer-readable medium of claim 1, wherein determining the total cost associated with execution of the activity comprises:

multiplying a cost associated with execution of the activity by the total number of threads waiting for at least one of the set of mutual-exclusion locks.

3. The non-transitory computer-readable medium of claim 1, wherein determining the total cost associated with execution of the activity comprises:

multiplying a period of time associated with execution of the activity by the total number of threads waiting for at least one of the set of mutual-exclusion locks.

4. The non-transitory computer-readable medium of claim 1, wherein determining the total cost associated with execution of the activity comprises:

multiplying a cost associated with a cache miss with a total number of threads waiting for at least one of the set of mutual-exclusion locks held by the first thread during execution of the activity.

5. The non-transitory computer-readable medium of claim 1, wherein the operations further comprise:

incrementing a counter associated with a particular mutual-exclusion lock of the set of mutual-exclusion locks in response to a particular thread waiting for the particular mutual-exclusion lock, wherein the counter identifies a number of threads currently waiting for the particular mutual-exclusion lock;

decrementing the counter in response to the particular thread obtaining the mutual-exclusion lock.

6. The non-transitory computer-readable medium of claim 1, wherein the operations further comprise implementing a performance optimization associated with execution of the activity based on the total cost associated with execution of the activity.

7. The non-transitory computer-readable medium of claim 6, wherein implementing the performance optimization comprises deferring execution of an operation until after release of at least one of the set of mutual-exclusion locks.

8. The non-transitory computer-readable medium of claim 6, wherein implementing the performance optimization comprises modifying a granularity corresponding to at least one of the set of mutual-exclusion locks.

9. The non-transitory computer-readable medium of claim 1, wherein the operations further comprise implementing a performance optimization associated with execution of each of a set of activities based on a cost associated with each of the set of activities relative to the cost of each of the other activities in the set of activities.

10. The non-transitory computer-readable medium of claim 1, wherein determining the total cost associated with execution of the activity is further based on a cost associated with execution of the activity by a second thread.

11. A method comprising:

identifying a first thread executing an activity;

determining a set of one or more mutual-exclusion locks held by the first thread while the activity is being executed;

determining a total number of threads waiting for at least one of the set of mutual-exclusion locks held by the first thread during execution of the activity; and

determining a total cost associated with execution of the activity based at least on the total number of threads waiting for at least one of the set of mutual-exclusion locks held by the first thread during execution of the activity.

12. The method of claim 11, wherein determining the total cost associated with execution of the activity comprises:

multiplying a cost associated with execution of the activity by the total number of threads waiting for at least one of the set of mutual-exclusion locks.

13. The method of claim 11, wherein determining the total cost associated with execution of the activity comprises:

multiplying a period of time associated with execution of the activity by the total number of threads waiting for at least one of the set of mutual-exclusion locks.

14. The method of claim 11, wherein determining the total cost associated with execution of the activity comprises:

multiplying a cost associated with a cache miss with a total number of threads waiting for at least one of the set of mutual-exclusion locks held by the first thread during execution of the activity.

15. The method of claim 11, further comprising:

incrementing a counter associated with a particular mutual-exclusion lock of the set of mutual-exclusion locks in response to a particular thread waiting for the particular mutual-exclusion lock, wherein the counter identifies a number of threads currently waiting for the particular mutual-exclusion lock;

decrementing the counter in response to the particular thread obtaining the mutual-exclusion lock.

16. The method of claim 11, further comprising implementing a performance optimization associated with execution of the activity based on the total cost associated with execution of the activity.

17. The method of claim 16, wherein implementing the performance optimization comprises deferring execution of an operation until after release of at least one of the set of mutual-exclusion locks.

18. The method of claim 16, wherein implementing the performance optimization comprises modifying a granularity corresponding to at least one of the set of mutual-exclusion locks.

19. The method of claim 11, wherein the operations further comprise implementing a performance optimization associated with execution of each of a set of activities based on a cost associated with each of the set of activities relative to the cost of each of the other activities in the set of activities.

20. The method of claim 11, wherein determining the total cost associated with execution of the activity is further based on a cost associated with execution of the activity by a second thread.