ADAPTIVE BANDWIDTH DISTRIBUTION SYSTEM FOR HIGH-PERFORMANCE INPUT/OUTPUT DEVICES WITH VARIABLE THROUGHPUT

• US 20090271537A1
• Filed: 07/24/2008
• Published: 10/29/2009
• Est. Priority Date: 04/23/2008
• Status: Active Grant

• Current Assignee: Autodesk, Inc.
• Original Assignee: Autodesk, Inc.
• Inventors: Vinet, Eric, Labute, Daniel
• Granted Patent: US 7,802,033 B2
• Time in Patent Office: Days
• US Class Current: 710/33
• CPC Class Codes: G06F 13/22 using successive scanning, e.g. polling G06F13/24 takes precedence
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0671 In-line storage system

Abstract

A method for issuing shadow requests to manage bandwidth allocation between an application that issues input/output (I/O) operation requests and an I/O device. A bandwidth manager detects the completion of an I/O operation, which includes either a read operation or a write operation. The bandwidth manager calculates a statistical duration for future I/O operations between the application and the I/O device based on throughput statistics related to past I/O operations. The bandwidth manager generates a shadow request for reserving a position in a queue that stores pending I/O requests for the I/O device for a first future I/O operation request from the application and having a duration related to the statistical duration, and inserts the shadow request into the queue. Advantageously, applications that do not make frequent I/O operation requests in advance may still execute I/O operations because bandwidth is reserved for future I/O operation requests via the shadow requests.

Claims

1. A method for issuing shadow requests to manage bandwidth allocation between an application that issues input/output (I/O) operation requests and an I/O device, the method comprising:

detecting the completion of an I/O operation that includes either a read operation from the I/O device to the application or a write operation from the application to the I/O device;

calculating a statistical duration for future I/O operations between the application and the I/O device based on throughput statistics related to past I/O operations between the application and the I/O device;

generating a first shadow request for reserving a first position in a queue that stores pending I/O requests for the I/O device for a first future I/O operation request from the application and having a duration related to the statistical duration; and

inserting the first shadow request into the queue.

2. The method of claim 1, further comprising the step of calculating an I/O operation request frequency reflecting the rate at which the application issues I/O operation requests to the I/O device and based on an average interval between timestamps recorded when the application issues I/O operation requests to an application programming interface.

3. The method of claim 2, further comprising the steps of generating a second shadow request for reserving a second position in the queue for a second future I/O operation request from the application, and inserting the second shadow request into the queue based on the I/O operation request frequency.

4. The method of claim 3, wherein the first shadow request and the second shadow request are separated from each other in the queue by the average interval.

5. The method of claim 1, wherein the step of calculating includes determining an average amount of data being transferred during I/O operations between the application and the I/O device based on information received from an application programming interface.

6. The method of claim 1, wherein the throughput statistics include the available bandwidth of the I/O device.

7. The method of claim 1, wherein the throughput statistics are used to compute average values for the statistical duration over a period of time.

8. The method of claim 1, wherein the I/O device comprises a hard disk, a memory, a computer monitor, or a disc drive.

9. The method of claim 1, wherein the duration is substantially equal to the statistical duration.

10. A computer-readable medium storing instructions that, when executed by a processor, cause a bandwidth manager to issue shadow requests to manage bandwidth allocation between an application that issues input/output (I/O) operation requests and an I/O device, by performing the steps of:

detecting the completion of an I/O operation that includes either a read operation from the I/O device to the application or a write operation from the application to the I/O device;

calculating a statistical duration for future I/O operations between the application and the I/O device based on throughput statistics related to past I/O operations between the application and the I/O device;

generating a first shadow request for reserving a first position in a queue that stores pending I/O requests for the 1/O device for a first future I/O operation request from the application and having a duration related to the statistical duration; and

inserting the first shadow request into the queue.

11. The computer-readable medium of claim 10, further comprising the step of calculating an I/O operation request frequency reflecting the rate at which the application issues I/O operation requests to the I/O device and based on an average interval between timestamps recorded when the application issues I/O operation requests to an application programming interface.

12. The computer-readable medium of claim 11, further comprising the steps of generating a second shadow request for reserving a second position in the queue for a second future I/O operation request from the application, and inserting the second shadow request into the queue based on the I/O operation request frequency.

13. The computer-readable medium of claim 12, wherein the first shadow request and the second shadow request are separated from each other in the queue by the average interval.

14. The computer-readable medium of claim 10, wherein the step of calculating includes determining an average amount of data being transferred during I/O operations between the application and the I/O device based on information received from an application programming interface.

15. The computer-readable medium of claim 10, wherein the throughput statistics include the available bandwidth of the I/O device.

16. The computer-readable medium of claim 10, wherein the throughput statistics are used to compute average values for the statistical duration over a period of time.

17. The computer-readable medium of claim 10, wherein the I/O device comprises a hard disk, a memory, a computer monitor, or a disc drive.

18. The computer-readable medium of claim 10, wherein the duration is substantially equal to the statistical duration.

19. A system for issuing shadow requests to manage bandwidth allocation between an application that issues input/output (I/O) operation requests and an I/O device, the system comprising:

a memory; and

a processor configured to;

detect the completion of an I/O operation that includes either a read operation from the I/O device to the application or a write operation from the application to the I/O device;

calculate a statistical duration for future I/O operations between the application and the I/O device based on throughput statistics related to past I/O operations between the application and the I/O device;

generate a first shadow request for reserving a first position in a queue that stores pending I/O requests for the I/O device for a first future I/O operation request from the application and having a duration related to the statistical duration; and

insert the first shadow request into the queue.