The present invention relates generally to an improved data processing system and method. More specifically, the present invention is directed to a system and method for differentiation of traffic types across root complexes in a multi-root PCI Express environment. The differentiation will prevent one traffic class from blocking the flow of another traffic class across multi-root systems.
Most modern computing devices make use of input/output (I/O) adapters and buses that utilize some version or implementation of the Peripheral Component Interconnect standard, which was originally created by Intel in the 1990s. The Peripheral Component Interconnect (PCI) standard specifies a computer bus for attaching peripheral devices to a computer motherboard. PCI Express, or PCIe, is an implementation of the PCI computer bus that uses existing PCI programming concepts, but bases the computer bus on a completely different and much faster serial physical-layer communications protocol. The physical layer consists, not of a bi-directional bus which can be shared among a plurality of devices, but of single uni-directional links, which are connected to exactly two devices.