Tracing profiling information using per thread metric variables with reused kernel threads

• US 8,117,599 B2
• Filed: 04/29/2008
• Issued: 02/14/2012
• Est. Priority Date: 07/06/2000
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Edmark, Ronald O'Neal, Levine, Frank Eliot, Urouhart, Robert J.
• Primary Examiner(s): KENDALL, CHUCK O
• Application Number:
  US12/111,543
• Publication Number:
  US 20090007075A1
• Time in Patent Office: 1,386 Days
• Field of Search: None
• US Class Current: 717/127
• CPC Class Codes: G06F 11/3612 by runtime analysis performance monitoring G06F11/3466

Abstract

A method and system for tracing profiling information using per thread metric variables with reused kernel threads is disclosed. In one embodiment kernel thread level metrics are stored by the operating system kernel. A profiler request metric information for the operating system kernel in response to an event. After the kernel thread level metrics are read by the operating system for a profiler, their values are reset to zero by the operating system kernel. The profiler then applies the metric values to base metric values to appropriate Java threads that are stored in nodes in a tree structure base on the type of event and whether or not the kernel thread has been reused. In another embodiment non-zero values of thread level metrics are entered on a liked list. In response to a request from a profiler, the operating system kernel reads each kernel thread'"'"'s entry in the linked list and zeros each entry. The profiler can then update the intermediate full tree snapshots of profiling information with the collection of non-zero metric variables.

Claims

1. A data processing system for monitoring performance of a program being executed using per thread metric variables with reused kernel threads comprising:

receiving means for receiving a value of a metric variable for a kernel thread;

determining means for determining if the kernel thread has been previously used by a first application thread; and

applying means for applying the value of the metric variable to a second application thread if the kernel thread has been previously used by the first application thread.

2. The data processing system recited in claim 1 above, further comprises:

identifying means for identifying the first application thread as being terminated based on the kernel thread having been previously used by the first application thread.

3. The data processing system recited in claim 1 above, wherein the first application thread is a current application thread based on the kernel thread having not been used.

4. The data processing system recited in claim 1 above, wherein the determining means for determining if the kernel thread has been previously used by the first application thread further comprises:

comparing means for comparing an identity of the kernel thread to a list of identities of previously used kernel threads.

5. The data processing system recited in claim 1 above, wherein the value of a metric variable for a kernel thread is a change in value of the metric variable since a last receipt of the metric variable for the kernel thread.

6. The data processing system recited in claim 1 above, wherein the metric variable relates to one of allocation bytes, allocation objects, time, live object and live bytes.

8. The data processing system of claim 1, wherein the value of the metric variable for the kernel thread is received in response to an event occurring based on the execution of the second application thread.

9. The data processing system of claim 1, wherein the applying means for applying the value of the metric variable to the second application thread includes means for increasing a current metric value for the second application thread in a node associated with the second application thread by an amount equal to the value of the metric variable.

7. A computer program product in a transitory computer readable medium for implementing a method for monitoring performance of a program being executed using per thread metric variables with reused kernel threads comprising:

receiving instructions for receiving a value of a metric variable for a kernel thread;

determining instructions for determining if the kernel thread has been previously used by a first application thread; and

applying instructions for applying the value of the metric variable to a second application thread if the kernel thread has been previously used by the first application thread.

10. The computer program product of claim 7, wherein the value of the metric variable for the kernel thread is received in response to an event occurring based on the execution of the second application thread.

11. The computer program product of claim 7, wherein the applying instructions for applying the value of the metric variable to the second application thread include instructions for increasing a current metric value for the second application thread in a node associated with the second application thread by an amount equal to the value of the metric variable.