Managing bandwidth allocation in a processing node using distributed arbitration

摘要

Management of access to shared resources within a system comprising a plurality of requesters and a plurality of target resources is provided. A separate arbitration point is associated with each target resource. An access priority value is assigned to each requester. An arbitration contest is performed for access to a first target resource by requests from two or more of the requesters using a first arbitration point associated with the first target resource to determine a winning requester. The request from the winning requester is forwarded to a second target resource. A second arbitration contest is performed for access to the second target resource by the forwarded request from the winning requester and requests from one or more of the plurality of requesters using a second arbitration point associated with the second target resource.

主权项

1. A method for managing access to shared resources within a system comprising a plurality of requesters and a plurality of target resources, the method comprising:
associating a separate arbitration with each of the plurality of target resources; assigning an access priority to each of the plurality of requesters; assigning a maximum wait count to each of the plurality of requesters; storing the maximum wait count of each of the plurality of requestors in a multi-bit field of a register; contending for access to a first target resource of the plurality of target resources by requests from two or more of the plurality of requesters using a first arbitration associated with the first target resource to determine a winning requester; providing a contention counter at the first arbitration for at least one of the requesters having a lower priority; performing a sequence of arbitration contests at the first arbitration for requests from the plurality of requesters for access to the first target resource; granting access to the first target resource to the winning requestor of each arbitration contest; incrementing the contention counter each time the lower priority requester loses an arbitration contest in a sequence of arbitration contests; elevating the priority of the lower priority requester when the contention counter reaches the corresponding maximum wait count; forwarding the priority of the request from the winning requester to be used while contending for access to the second target resource, said forwarded priority being an elevated priority if the winning requestor had an elevated priority; forwarding the request from the winning requester from the first target resource to a second target resource of the plurality of target resources; and contending for access to the second target resource by the forwarded request and requests from one or more of the plurality of requesters using a second arbitration associated with the second target resource.