Method and apparatus for deprioritizing a high priority client

• US 20030158982A1
• Filed: 02/15/2002
• Published: 08/21/2003
• Est. Priority Date: 02/15/2002
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Navale, Aditya, Sadowsky, Jonathan B.
• Granted Patent: US 6,842,807 B2
• Time in Patent Office: Days
• US Class Current: 710/107
• CPC Class Codes: G09G 5/395 Arrangements specially adapted for transferring the contents of the bit-mapped memory to the screen G09G5/399 takes precedence

Abstract

A method and apparatus of deprioritizing a high priority client. An isochronous data stream request is generally referred to as a “high priority” client. These high priority requests are sensitive to time, such that a certain amount of data must be retrieved within a certain amount of time. The fetching of this data will cause increased latencies on lower priority clients making requests for data. A method and apparatus for deprioritizing a high priority client is needed to improve the efficiency in handling data traffic requests from both high priority and lower priority clients.

Claims

1. A method of prioritizing a data stream request, comprising:

determining a discrete integral of expected average bandwidth of said data stream request;

determining a discrete integral of actual bandwidth of said data stream request;

calculating a difference between said discrete integral of expected average bandwidth and said discrete integral of actual bandwidth; and

prioritizing said data stream request based on a polarity of said calculation.

2. The method of claim 1 wherein prioritizing said data stream request is utilized to determine a priority of a data stream request from a first client with respect to a data stream request from a second client.

3. A method of prioritizing an isochronous overlay data stream request, comprising:

determining a discrete integral of expected average bandwidth of said overlay data stream request;

determining a discrete integral of actual bandwidth of said overlay data stream request;

calculating a difference between said discrete integral of expected average bandwidth and said discrete integral of actual bandwidth; and

prioritizing said overlay data stream request based on a polarity of said calculation.

4. The method of claim 3 wherein determining said discrete integral of expected average bandwidth comprises:

determining a number of core clock cycles for a video display to display one scanline;

determining an amount of data to be fetched for one scanline;

determining a number of bytes per scanline, as a fixed stepvalue; and

calculating a number of core clocks per step, as a timeslice, in accordance with the stepvalue.

5. The method of claim 4 wherein determining said discrete integral of actual bandwidth comprises:

tracking an individual request of said overlay data stream request; and

increasing a counter by an amount of data of said individual request.

6. The method of claim 5 wherein the difference between said discrete integrals is the discrete integral of expected average bandwidth minus the discrete integral of actual bandwidth.

7. The method of claim 6 wherein when said polarity is one of positive and zero, said overlay data stream requests have a higher priority than central processing unit requests.

8. The method of claim 7 wherein when said polarity is negative, said overlay data stream requests have a lower priority than central processing unit requests.

9. A system for prioritizing data stream requests to memory, comprising:

a prioritizing device coupled to said memory, wherein said prioritizing device is to calculate a value to determine priority of said data stream requests to said memory.

10. The system of claim 9 further comprising:

a lower priority client coupled to said prioritizing device to send at least one of said data stream requests; and

a higher priority client coupled to said prioritizing device to send at least one of said data stream requests.

11. The system of claim 10 wherein said prioritizing device determines the priority of said data stream requests from said higher priority client with respect to said data stream requests from said lower priority client.

12. The system of claim I1 wherein said lower priority client includes a processor.

13. The system of claim 12 wherein said data stream requests from said higher priority client include isochronous data stream requests.

14. The system of claim 13 wherein said high priority client includes a video adapter within an integrated chipset graphics system.

15. A set of instructions residing in a storage medium, said set of instructions capable of being executed by a processor to implement a method to deprioritize the priority level of an isochronous data stream request, the method comprising:

determining a discrete integral of expected average bandwidth of said data stream request;

determining a discrete integral of actual bandwidth of said data stream request;

calculating a difference between said discrete integral of expected average bandwidth and said discrete integral of actual bandwidth; and

prioritizing said data stream request based on the polarity of said calculation.

16. The set of instructions of claim 15 wherein determining said discrete integral of expected average bandwidth comprises:

determining a number of core clock cycles for the monitor to display one scanline;

determining an amount of data to be fetched for one scanline;

determining a number of bytes per scanline , as a fixed stepvalue; and

calculating a number of core clocks per step, as a timeslice, in accordance with the stepvalue.

17. The set of instructions of claim 16 wherein determining said discrete integral of actual bandwidth comprises:

tracking an individual request of said overlay data stream request; and

increasing a counter by an amount of data of said individual request.

18. The set of instructions of claim 17 wherein the difference between said discrete integrals is the discrete integral of expected average bandwidth minus the discrete integral of actual bandwidth.