ASSOCIATING PROCESS PRIORITY WITH I/O QUEUING

• US 20100082855A1
• Filed: 09/29/2008
• Published: 04/01/2010
• Est. Priority Date: 09/29/2008
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Accapadi, Jos, Dunshea, Andrew, Mallempati, Vandana, Mena, Agustin III
• Granted Patent: US 9,262,357 B2
• Time in Patent Office: Days
• US Class Current: 710/39
• CPC Class Codes: G06F 13/362 with centralised access control
• CPC Class Codes: G06F 13/364 using independent requests or grants, e.g. using separated request and grant lines

Abstract

Input/output (I/O) requests generated by processes are typically stored in I/O queues. Because the queued I/O requests may not be associated with the processes that generated them, changing a process'"'"' priority may not affect the priority of the I/O requests generated by the process. Therefore, after the process'"'"' priority has been increased, it may be forced to wait for an I/O handler to service its I/O request, which may be stuck behind an I/O request generated by a lower priority process. Functionality can be implemented to associate the processes'"'"' priorities with the I/O requests generated by the processes. Also, reordering the queued I/O requests to reflect changes in the processes'"'"' priorities can ensure that the I/O requests from high priority processes are serviced before the I/O requests from low priority processes. This can ensure efficient processing and lower wait times for high priority processes.

Claims

1. A method comprising:

detecting one or more incoming input-output (I/O) requests, wherein the I/O requests originate from one or more processes;

storing the incoming I/O requests in an I/O queue, wherein the I/O queue is managed by an I/O handler;

determining information associated with the one or more processes from which the I/O requests originated, wherein the determined information comprises one or more priorities of the one or more processes;

sorting the I/O requests in the I/O queue, based at least in part on, the process priorities.

2. The method of claim 1, wherein the I/O handler comprises any one of a kernel, a plug-in to an operating system, a plug-in to an application, and a process.

3. The method of claim 1, wherein the information associated with the one or more processes comprises one or more of a process identification number, a process name, and a process priority.

4. The method of claim 1, wherein the information associated with the one or more processes is encoded in any one of an I/O request'"'"'s header and a structure in memory, wherein the I/O request comprises a reference to the structure in memory.

5. The method of claim 1, wherein the sorting the I/O requests in the I/O queue comprises dynamically reordering the I/O requests based at least in part on the determined information associated with the one or more processes from which the I/O requests originated.

6. The method of claim 1 further comprising:

determining that the priority of a first of the one or more processes changes to a different priority;

determining a first of the one or more requests associated with the first process; and

moving the first request from the I/O queue to a second I/O queue, wherein the second I/O queue is associated with the different priority.

7. The method of claim 1 further comprising:

detecting a termination of a first of the one or more processes from which at least one of the one or more I/O requests in the I/O queues originated;

determining the priority of the first process; and

associating the one or more I/O requests with the priority of the first process.

8. A method comprising:

detecting a modification in priority information associated with a process that changes the process from a first priority to a second priority, wherein one or more I/O requests originating from the process is stored in one or more I/O queues;

determining the one or more I/O requests in the one or more I/O queues;

associating the second priority with the one or more I/O requests associated with the process; and

servicing the one or more I/O requests based on the second priority.

9. The method of claim 8 further comprising sorting a plurality of I/O requests, which include the one or more I/O requests associated with the process, stored in the one or more I/O queues in response to said associating the second priority with the one or more I/O requests associated with the process.

10. The method of claim 8, further comprising:

changing a priority of a second I/O request from a third priority to a fourth priority;

determining a process which generated the second I/O request; and

changing a priority of the process to the fourth priority.

11. The method of claim 8 further comprising modifying priority associated with a first of the one or more I/O requests independent of the other I/O requests and of the process.

12. One or more machine-readable media having stored therein a program product, which when executed by a set of one or more processor units causes the set of one or more processor units to perform operations that comprise:

detecting one or more incoming input-output (I/O) requests, wherein the I/O requests originate from one or more processes;

storing the incoming I/O requests in an I/O queue, wherein the I/O queue is managed by an I/O handler;

determining information associated with the one or more processes from which the I/O requests originated, wherein the determined information comprises one or more priorities of the one or more processes;

sorting the I/O requests in the I/O queue, based at least in part on, the process priorities.

13. The machine-readable media of claim 12, wherein the I/O handler comprises any one of a kernel, a plug-in to an operating system, a plug-in to an application, and a process.

14. The machine-readable media of claim 12, wherein the information associated with the one or more processes comprises one or more of a process identification number, a process name, and a process priority.

15. The machine-readable media of claim 12, wherein the information associated with the one or more processes is encoded in any one of an I/O request'"'"'s header and a structure in memory, wherein the I/O request comprises a reference to the structure in memory.

16. The machine-readable media of claim 12, wherein the operation of sorting the I/O requests in the I/O queue comprises dynamically reordering the I/O requests based, at least in part, on the determined information associated with the one or more processes from which the I/O requests originated.

17. The machine-readable media of claim 12, wherein the operations further comprise:

determining that the priority of a first of the one or more processes changes to a different priority;

determining a first of the one or more requests associated with the first process; and

moving the first request from the I/O queue to a second I/O queue, wherein the second I/O queue is associated with the different priority.

18. The machine-readable media of claim 12, wherein the operations further comprise:

detecting a termination of a first of the one or more processes from which at least one of the one or more I/O requests in the I/O queues originated;

determining the priority of the first process; and

associating the one or more I/O requests with the priority of the first process.

19. An apparatus comprising:

a set of one or more processors;

a network interface coupled with the set of one or more processors;

an input/output (I/O) queue manager operable to,

detect one or more incoming I/O requests, wherein the I/O requests originate from one or more processes;

store the incoming I/O requests in an I/O queue, wherein the I/O queue is managed by an I/O handler;

determine information associated with the one or more processes from which the I/O requests originated, wherein the determined information comprises one or more priorities of the one or more processes; and

sort the I/O requests in the I/O queue, based at least in part on, the process priorities.

20. The apparatus of claim 19, wherein the I/O queue manager comprises one or more machine-readable media.