Patent ID: 6108739
Filing Date: 2000-08-22
Classification: G06F

Abstract:
A method for avoiding split-response-bus conflicts in a multiprocessor computer system, the multiprocessor computer system including a first node and a second mode coupled to the split-response bus, wherein the first and second nodes communicate by passing request packets over the split-response bus, wherein the first node is a requesting node, further wherein the multiprocessor system includes a PCI adapter having a node Id coupled to a split-response and to a PCI bus, the PCI adapter operable to detect a read request conflict when a split-response-to-PCI-BUS read request is received while a PCI-BUS-to-split-response read request is active, each of the read requests including a source Id and a target Id, the method including the steps of:(a) providing precedence information in the request packets, wherein the multiprocessor system includes a particular topology, step (a) further including the step of:(a1) providing the precedence information by including a precedence label in the request packets indicating where the requesting node is located in the topology of multiprocessor system; and(b) using the precedence information upon receiving the request packets to determine which request packets to process and which request packets to reject when a conflict occurs(c) performing conflict resolution by rejecting the received read request at the adapter unless I) the adapter node Id is less than the source Id within the received read-request, and ii) the adapter node Id is less than the target Id of the active read request.