Patent ID: 7631050
Filing Date: 2009-12-08
Classification: G06F

Abstract:
1. In a distributed computer system provided with multiple root nodes, each root node comprising a host CPU set, that share a number of PCI adapters through an input/output (I/O) fabric comprising a number of PCI buses and switches, a method comprising the steps of: selecting one of said root nodes to be master root node for said system, wherein the root nodes share a number of PCI buses, and wherein the master root node has a PCI configuration manager (PCM) component; operating the PCM component in the selected root node to implement a procedure whereby the selected root node iteratively queries a configuration space of each of said PCI switches, wherein the PCM component configures all routings through the I/O fabric for the PCI switches by setting the configuration space for each of the PCI switches; detecting whether a particular PCI switch has been configured by another PCM component in a different root node; responsive to detecting that the particular PCI switch has been configured by the other PCM component in the different root node, implementing a challenge procedure to confirm whether the selected root node is the master root node, wherein the configuration space of the particular PCI switch is set by the PCM component of the selected root node if the selected root node is confirmed to be the master root node; continuing said configuration space querying procedure, if the selected root node is confirmed to be the master root node by said challenge procedure; aborting the configuration space querying procedure if the selected root node is not confirmed to be the master root node by the challenge procedure; and responsive to detecting that the particular PCI switch has not been configured by the other PCM component in the different root node, setting the configuration space for the particular PCI switch by the PCM component of the selected root node.