System, method and medium for using and/or providing operating system information to acquire a hybrid user/operating system lock

• US 7,765,548 B2
• Filed: 02/17/2005
• Issued: 07/27/2010
• Est. Priority Date: 02/17/2005
• Status: Active Grant

• Current Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Original Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Inventors: Cox, Alan
• Primary Examiner(s): An; Meng-Ai
• Assistant Examiner(s): WAI, ERIC CHARLES
• Application Number:
  US11/059,564
• Publication Number:
  US 20060184942A1
• Time in Patent Office: 1,986 Days
• Field of Search: 718/100
• US Class Current: 718/100
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms

Abstract

A system, method and medium for utilizing data indicative of operating system activity to determine if a process should continue to attempt to acquire a lock, or make a call to an operating system.

Claims

1. A method for utilizing data indicative of operating system scheduling in shared user-operating system memory space, comprising:

providing, by the operating system, data to a shared user-operating system memory space that is indicative of scheduled operating system activities, the data representing requests made by processes, the data being assessable by a user process so that the user process can make a determination as to how to acquire a lock;

detecting, by the operating system, an attempt to acquire the lock by the user process; and

receiving a call by the operating system, subsequent to said detecting step, from the user process when the number of scheduled operating system activities exceeds a predetermined number, the user process deciding to make the call based on the data in the shared user-operating system memory space, the user process making a second attempt to acquire the lock when the number of scheduled operating system activities does not exceed the predetermined number, the user process deciding to make the second attempt based on the data in the shared user-operating system memory space,

wherein the data provided to the shared user-operating system memory space comprises a copy of user-process requests in an I/O queue of the operating system.

2. The method of claim 1, wherein the operating system operates in conjunction with a multiprocessor system.

3. The method of claim 2, wherein the data in the shared user-operating system memory space is indicative of scheduled operating system activities for each processor of the multiprocessor system.

4. A method of utilizing data provided by an operating system to shared user-operating system memory space, comprising:

storing a version of data representing a number of actual scheduled operating system activities;

providing, by the operating system, data representing a number of operating system activities to a shared user-kernel memory space that is not indicative of the number of actual scheduled operating system activities, the data to the shared user-kernal memory space being operative to represent a greater number of operating system activities than the version of data representing the number of actual scheduled operating system activities;

detecting, by the operating system, an attempt to acquire a lock by a user process; and

receiving a call by the operating system, subsequent to said detecting step, from the user process when the number of operating system activities represented by the data to the shared user-kernal memory space exceeds a predetermined number, the user process making a second attempt to acquire the lock when the number of scheduled operating system activities represented by the data to the shared user-kernal memory space does not exceed the predetermined number.

5. The method of claim 4, wherein the operating system operates in conjunction with a multiprocessor system.

6. The method of claim 5, wherein the data in the shared user-operating system memory space represents operating system activities for each processor of the multiprocessor system.

7. The method of claim 4, wherein the data to the shared user-kernal memory space is assessable by the user process to make a determination to call the operating system.

8. A computer program product residing on a computer storage medium, the computer program product comprising instructions for causing a computer to:

provide, by an operating system, data to a shared user-operating system memory space storage that is indicative of scheduled operating system activities, the data representing requests made by the processes, the data being assessable by a user process so that the user process can make a determination as to how to acquire a lock;

detect, by the operating system, an attempt by a user process to acquire the lock; and

(i) receive a call by the operating system, subsequent to an attempt by the user process to acquire the lock, from the user process when the number of scheduled operating system activities exceeds a predetermined number, the user process deciding to make the call based on the data in the shared user-operating system memory space, and (ii) make, by the user process, a second attempt to acquire the lock when the number of scheduled operating system activities does not exceed a predetermined number, the user process deciding to make the second attempt based on the data in the shared user-operating system memory space,

wherein the data provided to the shared user-operating system memory space comprises a copy of user-process requests in an I/O queue of the operating system.

9. The computer program product of claim 8, wherein the operating system operates in conjunction with a multiprocessor system.

10. The computer program product of claim 9, wherein the data in the shared user-operating system memory space is indicative of scheduled operating system activities for each processor of the multiprocessor system.

11. A computer program product residing on a computer storage medium, the computer program product comprising instructions for causing a computer to:

store a version of data representing a number of actual scheduled operating system activities;

provide, by an operating system, data representing a number of operating system activities to a shared user-operating system memory space, that is not indicative of the number of actual scheduled operating system activities, the data to the shared user-operating system memory space being operative to represent a greater number of operating system activities than the version of data representing the number of actual scheduled operating system activities;

detect, by the operating system, an attempt by a user process to acquire a lock; and

receive a call by the operating system, subsequent to an attempt by the user process to acquire the lock, from the user process when the number of operating system activities represented by the data to the shared user-operating system memory space exceeds a predetermined number, the user process making a second attempt to acquire the lock when the number of scheduled operating system activities represented by the data to the shared user-operating system memory space does not exceed the predetermined number.

12. The computer program product of claim 11, wherein the operating system operates in conjunction with a multiprocessor system.

13. The computer program product of claim 12, wherein the data in the shared user-operating system memory space represents operating system activities for each processor of the multiprocessor system.

14. The computer program product of claim 11, wherein the data to the shared user-operating system memory space is assessable by the user process to make a determination to call the operating system.

15. A system for utilizing data indicative of operating system scheduling in shared user-operating system memory space, comprising:

an operating system;

a shared user-operating system memory space comprising data indicative of scheduled operating system activities, the data containing requests made by processes, the data being assessable by a user process so that the user process can make a determination as to how to acquire a lock, wherein the operating system (i) receives a call from a user process that has attempted to acquire the lock if the number of scheduled operating system activities exceeds a predetermined number, the user process deciding to make the call based on the data in the shared user-operating system memory space, and (ii) the user process makes a second attempt to acquire the lock when the number of scheduled operating system activities does not exceed a predetermined number, the user process deciding to make the second attempt based on the data in the shared user-operating system memory space; and

a hardware processor in communication with the user process,

wherein the data provided to the shared user-operating system memory space comprises a copy of user-process requests in an I/O queue of the operating system.

16. The system of claim 15, wherein the operating system operates in conjunction with a multiprocessor system.

17. The system of claim 16, wherein the data in the shared user-operating system memory space is indicative of scheduled operating system activities for each processor of the multiprocessor system.

18. A system for utilizing data provided, by an operating system, to shared user-operating system memory space, comprising:

an operating system;

a stored version of data representing a number of actual scheduled operating system activities;

a shared user-operating system memory space comprising data representing a number of operating system activities that is not indicative of the number of actual scheduled operating system activities, the data in the shared user-operating system memory space being operative to represent a greater number of operating system activities than the version of data representing the number of actual scheduled operating system activities, wherein the operating system (i) receives a call from a user process that has attempted to acquire a lock if the number of operating system activities represented by the data to the shared user-operating system memory space exceeds a predetermined number, and (ii) the user process makes a second attempt to acquire the lock when the number of scheduled operating system activities represented by the data to the shared user-operating system memory space does not exceed the predetermined number; and

a hardware processor in communication with the user process.

19. The system of claim 18, wherein the operating system operates in conjunction with a multiprocessor system.

20. The system of claim 19, wherein the data in the shared user-operating system memory space represents operating system activities for each processor of the multiprocessor system.

21. The system of claim 18, wherein the data to the shared user-operating system memory space is assessable by a user process to make a determination to call the operating system.