GATHERING PAGES ALLOCATED TO AN APPLICATION TO INCLUDE IN CHECKPOINT INFORMATION

• US 20090183181A1
• Filed: 01/11/2008
• Published: 07/16/2009
• Est. Priority Date: 01/11/2008
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Subhraveti, Dinesh Kumar
• Granted Patent: US 8,510,757 B2
• Time in Patent Office: Days
• US Class Current: 719/320
• CPC Class Codes: G06F 11/1438 Restarting or rejuvenating
• CPC Class Codes: G06F 11/3644 by instrumenting at runtime
• CPC Class Codes: G06F 11/3696 Methods or tools to render software testable
• CPC Class Codes: G06F 9/4856 resumption being on a different machine, e.g. task migration, virtual machine migration G06F9/5088 takes precedence

Abstract

Provided are a method, system, and program for gathering pages allocated to an application to include in checkpoint information. A call from an application is intercepted to allocate memory pages to cause indication of pages allocated to the application that have modified data. An operation is initiated to create checkpoint information for the application. Pages allocated to the application that have modified data are determined in response to the operation to create the checkpoint information. The determined pages are saved in the checkpoint information.

Claims

1. A method, comprising:

intercepting a call from an application to allocate memory pages to cause indication of pages allocated to the application that have modified data;

initiating an operation to create checkpoint information for the application;

determining pages allocated to the application that have modified data in response to the operation to create the checkpoint information; and

saving the determined pages in the checkpoint information.

2. The method of claim 1, wherein pages allocated to the application not including modified data are not saved in the checkpoint information.

3. The method of claim 1, wherein the call in the application to allocate the memory comprises a first memory allocation function, wherein intercepting the first memory allocation function comprises modifying the application to replace the first memory allocation function with a second memory allocation function having a write watch parameter that directs the operating system to indicate pages allocated to the application that have modified data.

4. The method of claim 1, further comprising:

indicating, by the operating system, pages allocated to the application that have modified data.

5. The method of claim 4, further comprising:

determining whether a page was allocated with a write watch parameter directing the operating system to indicate pages having modified in response to modifying data in the page, wherein the page is indicated as having modified data in response to modifying the page and in response to determining that the page was allocated with the write watch parameter directing the operating system to indicate the page as having modified data.

6. The method of claim 4, further comprising:

calling, by a checkpoint agent, the operating system to determine pages allocated to the application that have modified data, wherein the checkpoint agent determines pages allocated to the application that have modified data from the operating system and saves the determined pages in the checkpoint information.

7. A system, comprising:

a processor;

a computer readable medium having an agent and an application, wherein the agent is executed by the processor to perform operations, the operations comprising;

intercepting a call from the application to allocate memory pages in the computer readable medium to cause indication of pages allocated to the application that have modified data;

initiating an operation to create checkpoint information for the application;

determining pages allocated to the application that have modified data in response to the operation to create the checkpoint information; and

saving the determined pages in the checkpoint information.

8. The system of claim 7, wherein pages allocated to the application not including modified data are not saved in the checkpoint information.

9. The system of claim 7, wherein the call in the application to allocate the memory comprises a first memory allocation function, wherein intercepting the first memory allocation function comprises modifying the application to replace the first memory allocation function with a second memory allocation function having a write watch parameter that directs the operating system to indicate pages allocated to the application that have modified data.

10. The system of claim 7, wherein the computer readable medium further includes an operating system executed by the processor to perform operating system operations comprising:

indicating pages allocated to the application that have modified data.

11. The system of claim 10, wherein the operating system operations further comprise:

determining whether a page was allocated with a write watch parameter directing the operating system to indicate pages having modified in response to modifying data in the page, wherein the operating system indicates the page as having modified data in response to modifying the page and in response to determining that the page was allocated with the write watch parameter directing the operating system to indicate the page as having modified data.

12. The system of claim 10, wherein the agent operations further comprise:

calling the operating system to determine pages allocated to the application that have modified data, wherein the agent determines pages allocated to the application that have modified data from the operating system and saves the determined pages in the checkpoint information.

13. An article of manufacture comprising a computer readable storage medium having code executed to perform operations, the operations, comprising:

intercepting a call from an application to allocate memory pages to cause indication of pages allocated to the application that have modified data;

initiating an operation to create checkpoint information for the application;

determining pages allocated to the application that have modified data in response to the operation to create the checkpoint information; and

saving the determined pages in the checkpoint information.

14. The article of manufacture of claim 13, wherein pages allocated to the application not including modified data are not saved in the checkpoint information.

15. The article of manufacture of claim 13, wherein the call in the application to allocate the memory comprises a first memory allocation function, wherein intercepting the first memory allocation function comprises modifying the application to replace the first memory allocation function with a second memory allocation function having a write watch parameter that directs the operating system to indicate pages allocated to the application that have modified data.

16. The article of manufacture of claim 13, wherein the code further includes operating system code executed to perform:

indicating pages allocated to the application that have modified data.

17. The article of manufacture of claim 16, wherein the operating system code further performs:

determining whether a page was allocated with a write watch parameter directing the operating system to indicate pages having modified in response to modifying data in the page, wherein the page is indicated as having modified data in response to modifying the page and in response to determining that the page was allocated with the write watch parameter directing the operating system to indicate the page as having modified data.

18. The article of manufacture of claim 16, wherein the code further includes agent code to perform:

calling the operating system to determine pages allocated to the application that have modified data, wherein the checkpoint agent determines pages allocated to the application that have modified data from the operating system and saves the determined pages in the checkpoint information.