Apparatus and method for priority queuing with segmented buffers

Abstract

Apparatus and methods for efficient queuing and dequeuing using segmented output buffers comprising sub-buffers and priority queues. Output buffers are monitored for empty sub-buffers. When a newly empty sub-buffer is discovered, a refill request is enqueued in a ranked priority queue wherein the rank of the destination priority queue is based on the number of empty-sub-buffers in the requesting output buffer. All high priority refill requests are dequeued before lower priority refill requests, thereby reducing the possibility of starvation. Optionally, by using simple dequeuing criteria, such as a FIFO discipline, instead of complex algorithms designed to improve fairness, system resources may be conserved thereby improving system throughput.

Description

RELATED CASES[0001]This application is a continuation of U.S. pending application ser. No. 10 / 927,801 filed Aug. 26, 2004, the entire disclosure of which is incorporated herein by reference.FIELD OF INVENTION [0002]Invention relates to apparatus and methods for reducing the risk of underflow in a multiple queue system.BACKGROUND OF INVENTION [0003]Queues are used in a variety of applications, especially where resources are shared. For example, queues may be used to manage traffic in routers, file and data servers or to schedule processes and / or threads in single and / or multi-processor systems. A variety of techniques may be used to prioritize resource requests in an effort to improve throughput or efficiency or to guarantee a quality of service (QoS). However, many of these techniques run the risk of starving some requesters. In order to address the issue of starvation, complex algorithms may be used to enqueue and / or de-queue resource requests based on a variety of parameters. Howe...

AI Technical Summary

Benefits of technology

"The present invention provides a queuing system that uses segmented output buffers and priority queues to efficiently handle data requests, queries, transactions, and network traffic. The system prioritizes refill requests based on the number of empty sub-buffers in the output buffer, reducing the possibility of starvation. The system uses a FIFO queuing discipline to dequeue each priority queue, improving system throughput. The sub-buffers may be the same size, improving fairness. The system can be used in software, hardware, or firmware and can be used in physical processes or systems where resources are distributed to multiple destinations."

Problems solved by technology

However, many of these techniques run the risk of starving some requesters.

However, when complex algorithms are used to reduce starvation, precious system resources are consumed by the increased calculations and / or delays are introduced, thereby reducing overall throughput.

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