Method and apparatus for ordering interconnect transactions in a computer system

Abstract

A system allows queuing interconnect transactions of a first transaction type and a second transaction type according to an interconnect protocol for a computer system with multiple nodes in a transaction order queue (TOQ). Interconnect transactions are dequeued from the TOQ and scheduled for a destination node through a buffer between the TOQ and a scheduler. Interconnect transactions of the first transaction type are blocked from the scheduler until all interconnect transactions scheduled for other nodes in the computer system have completed. No interconnect transactions are dequeued from the TOQ while an interconnect transactions of the first transaction type is blocked from the scheduler. The queuing technique imposes an additional ordering on interconnect transactions in addition to ordering rules of the interconnect protocol.