Achieving autonomic behavior in an operating system via a hot-swapping mechanism

• US 20050071811A1
• Filed: 09/29/2003
• Published: 03/31/2005
• Est. Priority Date: 09/29/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Silva, Dilma Menezes Da, Krieger, Orran Yaakov, Appavoo, Jonathan, Wisniewski, Robert William, Hui, Kevin Kin-Fai, Auslander, Marc Alan
• Granted Patent: US 7,533,377 B2
• Time in Patent Office: Days
• US Class Current: 717/122
• CPC Class Codes: G06F 8/656 while running

Abstract

Systems, especially operating systems, are becoming more complex to the point where maintaining them by humans is becoming nearly impossible. Many corporations have recognized this trend and have begun investing in autonomic technology. Autonomic technology allows a piece of software to monitor, diagnose, and repair itself. This can be used for improved performance, reliability, maintainability, security, etc. Disclosed herein is a mechanism to allow operating systems to hot swap a piece of operating system code, while continuing to offer to the user the service which that code is providing. This can be used, for examples, to increase the performance of an application or to fix a detected security hole live without bringing the machine down. Some autonomic ability will be mandatory in next generation operating system for without it they will collapse under their own complexity. The invention offers a key component of being able to achieve autonomic computing.

Claims

1. In a computer system using an operating system to provide access to hardware resources, wherein said operating system provides access to said resources via a first source code component, a method of replacing said first source code component with a new source code component while said operating system remains active and while said operating system provides continual availability to applications of the hardware resources, the method comprising:

identifying references to said first source code component; and

replacing the identified references to said first source code with references to said new source code component.

2. A method according to claim 1, wherein the method is implemented transparently to said applications.

3. A method according to claim 1, wherein the method is scalable.

4. A method according to claim 1, wherein said mechanism is divided across a multiprocessor system so that each processor can proceed independently.

5. A method according to claim 1, wherein the replacing step includes the steps of:

establishing a quiescent state for the first code component;

transferring said quiescent state from the first code component to the new code component; and

after transferring said quiescent state, swapping the first code component with the new code component.

6. A method according to claim 1, wherein the step of identifying references includes the steps of:

separating the first code component into objects; and

grouping said objects into a table, whereby references to said objects are entered in the table.

7. A method according to claim 1, wherein the replacing step includes the steps of:

establishing a quiescent state for the first code component, without locking the first code component, by tracking active threads to the first code component;

transferring said quiescent state from the first code component to the new code component; and

after transferring said quiescent state, swapping the first code component with the new code component.

8. A method according to claim 1, wherein the replacing step includes the steps of:

establishing a quiescent state for the first code component;

transferring the quiescent state from the first code component to the new code component by providing an infrastructure to negotiate a best transfer algorithm; and

after transferring said quiescent state, swapping the first code component with the new code component.

9. A method according to claim 1, wherein:

the step of identifying references includes the steps of

separating the first code component into objects, and

grouping said objects into a table, whereby references to said objects are entered in the table; and

the replacing step includes the steps of

establishing a quiescent state for the first code component;

transferring the quiescent state from the first code component to the new code component by providing an infrastructure to negotiate a best transfer algorithm; and

after transferring said quiescent state, swapping the first code component with the new code component.

10. A system for swapping source code in a computer system including an operating system, said operating system including at least one source code component and providing continual availability to applications of hardware resources, the system comprising:

means for identifying, while said operating system is active and providing continual access to said resources, references to a first source code component of the operating system; and

means for replacing the identified references, while said operating system is active and providing continual access to said resources, to said first source code with references to a new source code component for the operating system.

11. A system according to claim 10, wherein the system operates transparently to said applications and the system is scalable.

12. A system according to claim 10, wherein said mechanism is divided across a multiprocessor system so that each processor can process independently.

13. A system according to claim 10, wherein the means for replacing step includes:

means for establishing a quiescent state for the first code component;

means for transferring said quiescent state from the first code component to the new code component; and

means for swapping the first code component with the new code component after said quiescent state has been transferred.

14. A system according to claim 10, wherein the means for identifying references includes:

means for separating the first code component into objects; and

means for grouping said objects into a table, whereby references to said objects are entered in the table.

15. A system according to claim 10, wherein the means for replacing includes:

means for establishing a quiescent state for the first code component, without locking the first code component, by tracking active threads to the first code component;

means for transferring said quiescent state from the first code component to the new code component; and

means for swapping the first code component with the new code component after said quiescent state has been transferred.

16. A system according to claim 10, wherein the means for replacing includes:

means for establishing a quiescent state for the first code component;

means for transferring the quiescent state from the first code component to the new code component by providing an infrastructure to negotiate a best transfer algorithm; and

means for swapping the first code component with the new code component after said quiescent state has been transferred.

17. A method according to claim 10, wherein:

the means for identifying references includes

i) means for separating the first code component into objects, and

ii) means for grouping said objects into a table, whereby references to said objects are entered in the table; and

the means for replacing includes

i) means for establishing a quiescent state for the first code component;

ii) means for transferring the quiescent state from the first code component to the new code component by providing an infrastructure to negotiate a best transfer algorithm; and

iii) means for swapping the first code component with the new code component after said quiescent state has been transferred.

18. A program storage device, for use with a computer system including an operating system to provide access to hardware resources, wherein said operating system provides access to said resources via a first source code component, said program storage device being readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for replacing said first source code component with a new source code component while said operating system remains active and while said operating system provides continual availability to applications of said resources, the method steps comprising:

identifying references to said first source code component; and

replacing the identified references to said first source code with references to said new source code component.

19. A program storage device according to claim 18, wherein the method is implemented transparently to said applications, the method is scalable, and said mechanism is divided across a multiprocessor system so that each processor can proceed independently.

20. A program storage device according to claim 18, wherein the replacing step includes the steps of:

establishing a quiescent state for the first code component;

transferring said quiescent state from the first code component to the new code component; and

after transferring said quiescent state, swapping the first code component with the new code component.

21. A program storage device according to claim 18, wherein the step of identifying references includes the steps of:

separating the first code component into objects; and

grouping said objects into a table, whereby references to said objects are entered in the table.

22. A program storage device according to claim 18, wherein the replacing step includes the steps of:

establishing a quiescent state for the first code component, without locking the first code component, by tracking active threads to the first code component;

transferring said quiescent state from the first code component to the new code component; and

after transferring said quiescent state, swapping the first code component with the new code component.

23. A program storage device according to claim 18, wherein the replacing step includes the steps of:

establishing a quiescent state for the first code component;

transferring the quiescent state from the first code component to the new code component by providing an infrastructure to negotiate a best transfer algorithm; and

after transferring said quiescent state, swapping the first code component with the new code component.

24. A program storage device according to claim 18, wherein:

the step of identifying references includes the steps of

i) separating the first code component into objects, and

ii) grouping said objects into a table, whereby references to said objects are entered in the table; and

the replacing step includes the steps of

i) establishing a quiescent state for the first code component;

ii) transferring the quiescent state from the first code component to the new code component by providing an infrastructure to negotiate a best transfer algorithm; and

iii) after transferring said quiescent state, swapping the first code component with the new code component.